BASIC SURGICAL SKILLS MANUAL
Principles and Applications
2nd Edition • Electronic Version
PHILIPPINE COLLEGE OF SURGEONS
• Committee on Surgical Training
Cenon R. Alfonso, MD - Committee Chairman
Miguel C. Mendoza, MD - Editor-in-Chief
Shirard L.C. Adiviso, MD, Jose Joey H. Bienvenida, MD,
and Renato Cirilo A. Ocampo, MD
Armando C. Crisostomo, MD - Regent-in-Charge.
Foreword
2nd Edition . . . Cenon R. Alfonso, MD, FPCS, Chairman Committee on Surgical Training, Philippine College of Surgeons 2003
Foreword
1st Edition . . . Gabriel L. Martinez, MD, FPCS, Chairman, Committee on Surgical Training, Philippine College of Surgeons 1999
Message from the 2003 PCS President
Fernando A. Lopez, MD, FPCS
Preface
2nd Edition . . . Armando C. Crisostomo, MD, FPCS, Regent-In-Charge (2003), Committee on Surgical Training, Philippine College of Surgeons
Preface
1st Edition . . . Jose Y. Cueto, MD, FPCS, Regent-In-Charge (1999), Committee on Surgical Training, Philippine College of Surgeons
Chapter I
Learning & Assessing Psychomotor Skills in Surgery
Jose Y. Cueto, Jr., MD, MHPEd, FPCS (1st edition) • Self-Assessment Questions
Chapter II
The Use of Simulation in Surgical Training Shirard L.C. Adiviso, MD, MHPEd, FPCS • Self-assessment Questions
Chapter III
Suture Materials
Jose Antonio M. Salud, MD, FPCS and Jerome G. Baldonado, MD, FPCS (1st edition) Joey H. Bienvenida, MD, FPCS (2nd edition) • Self-assessment Questions
Chapter IV
Surgical Needles
Cenon R. Alfonso, MD, FPCS and
Nilo C. de los Santos, MD, FPCS (1st edition) Renato A. Ocampo, MD, FPCS (2nd edition) • Self-assessment Questions
Table of Contents
Chapter V Knot Tying
Jose Antonio M. Salud, MD, FPCS (1st edition) Miguel C. Mendoza, MD, FPCS (2nd edition) • Self-assessment Questions
Chapter VI
Suturing Techniques
Cenon R. Alfonso, MD, FPCS,
Shirard L.C. Adiviso, MD, MHPEd, FPCS, Jose Joey H. Bienvenida, MD, FPCS, Miguel C. Mendoza, MD, FPCS, and
Renato Cirilo A. Ocampo, MD, FPCS (2nd edition) • Self-assessment Questions
Chapter VII
Clinical Applications Cenon R. Alfonso, MD, FPCS, Jerome G. Baldonado, MD, FPCS, Alejandro C. Dizon, MD, FPCS, Rene C. Encarnacion, MD, FPCS, Eduardo S. Eseque, MD, FPCS, Gabriel L. Martinez, MD, FPCS, Paul Jesus S. Montemayor, MD, FPCS, Jose Antonio M. Salud, MD, FPCS, and Jose A. Solomon, MD, FPCS.• Plastic Closure of Skin Lacerations • Skin Closure with Skin Adhesives • Abdominal Wall Closure
• Inguinal Herniorrhaphy/ Repair of the Inguinal Floor
• Appendectomy
• Cholecystectomy & Surgery of the Bile Ducts • Liver Trauma
• Bowel Anastomosis
• Vascular Anastomosis & Repair • Application of Retention Sutures • Self-assessment Questions Appendix A (Glossary of terms)
Appendix B (Answers to self-assessment questions) 2003 PCS Board of Regents
2003 Committee on Surgical Training Acknowledgement
Even a full decade before the turn of the 21st Century, the growing movement toward a paradigm shift of surgical skills training has already begun. This shift is from the operating-room-patient venue into the surgical skills laboratory-simulation setting.
Because of this propensity, it will become unaccept-able in the near future for young surgical trainees to be allowed to “practice” and hone their basic surgical techniques among patients in the operating room.
Furthermore, it may also come to a point that before being allowed to do so, these trainees will be required to pass a certification from a surgical skills laboratory. This means that the essential principles of mastery in psychomotor skills - repetition and feedback - have been adequately satisfied. This likewise implies that the trainee has progressed from being unconsciously incompetent in surgical techniques as they started into unconsciously competent as they ended (mastery) their surgical skills training.
The hope is once the trainee is faced with an actual
Foreword
• 2nd Edition
patient, basic surgical technique is almost second nature.
The first step towards the above-mentioned goal is to be able to experience an audiovisual simulation. This is the importance of this CD version and Edition of the Basic Surgical Skills Manual.
To all the members of the CST, Atong, Shirard, Joey, and Ike, most specially to the Regent-in-Charge, Armand, thank you and congratulations for all your selfless efforts, contributions, and seemingly-endless proddings.
An audiovisual simulation in basic surgical technique
Cenon R. Alfonso, MD, FPCS Chairman,
Committee on Surgical Training (2003) Philippine College of Surgeons
This manual was conceived in 1996 in answer to a palpable need for a structured, problem-oriented instructional tool for trainees and surgical practitioners.
In 1998, during the incumbency of Dr. Antonio B. Sison, the Committee on Surgical Training (CST) through its Chairman, Dr. Gabriel L. Martinez presented the project proposal to the PCS Board of Regents. The favorable action of the Board of Regents led to the creation of the Sub-committee on Skills Improvement under Dr. Jose Antonio M. Salud.
While diligently collecting and collating data from the various makers of surgical needles and sutures for inclusion in the Basic Surgical Skills manual, the CST made representations with Johnson & Johnson Medical Philippines through Mr. Bayani R. Santos, Jr. and Mr. Erwin Tantoco who favorably endorsed the project.
In 1999, during the incumbency of Dr. Francisco Y. Arcellana, the drafts of the Manual were presented to the Board of Regents for comments and suggestions. Once approval was obtained, the CST, and J & J
Foreword
• 1st Edition
through its Franchise Manager, Ms. Ruth Nicolas, engaged the services of Creative Powerhauz to publish this manual.
As in any endeavor, there are unsung heroes whose efforts were vital to the completion of this project: the members of the 1998 and 1999 Committee on Surgical Training, Regent-representative Dr. Jose Y. Cueto, Jr., contributors Drs. Nilo C. de los Santos and Paul Jesus S. Montemayor. Special thanks to Dr. Elizabeth F.
Mabilangan-Salud and Ms. Olivia S.M. Manzano, CST secretary.
Addressing need for problem-oriented instructional tool
Gabriel L. Martinez, MD, FPCS Chairman,
Committee on Surgical Training (1999) Philippine College of Surgeons
Clinical acumen, surgical knowledge and decision-making, and the right attitude and motivation do not make up a complete Surgeon.
These have to be adequately matched by a set of fine psychomotor skills, i.e. mastery of technical compe-tence. Training of young physicians into the Art and Science of Surgery therefore requires not only intensive education, but equally important, is the toning of every muscle and discipline of each movement they create during operations into a purposeful progress towards the goal of every procedure they perform.
This aspect of surgical training essentially requires two basic learning principles, namely: repetition and feedback.
This feat of the Committee on Surgical Training is the first step towards this end. A visual companion into the world of Surgical Technique allows application of almost all the senses in order to guide the young trainee in the “HOW” of the procedures.
In the short term, the Board of Regents envisions this project to serve as a guide to trainees. So that before a
Message from the 2003 PCS President
The backbone for all cutting specialties
certain technique is performed by simulation or in a patient, the young trainee can view this first and then play back for feedback.
In the long term however, this CD Edition of the Basic Surgical Skills Manual will play as the backbone of the National Surgical Skills Center (NSSC) that PCS will establish for all cutting specialties.
In behalf of the Board of Regents, let me congratu-late the Committee on Surgical Training for this project. Allow me to extend a similar warm recognition to the partner of PCS in this project, Johnson & Johnson Medical Philippines.
Fernando L. Lopez, MD President 2003
Preface
• 2nd Edition
Despite all the attention given to the development of a strong basic theoretical foundation in surgery and the enhancement of attitudinal competencies, the surgeons of today continue to be judged mainly by the quality of their technique in the performance of various surgical procedures.
Major requirements for the accreditation of residency training programs in surgery continue to highlight the need for adequate operative experience in order to ensure the competency of our trainees.
Despite the importance of the operative skill, continuing education in this regard continues to be wanting. Also, there is a need to standardize the teaching of surgical technique to our students and residents while appreciating some variation in individual style.
With this in mind, the Surgical Training Committee of the Philippine College of Surgeons has embarked on this endeavor to further improve the initial landmark publication of the Basic Surgical Skills Manual, this time in electronic form.
Subsequently, we intend to pursue publication of the Advanced Surgical Skills Manual, which highlights more advanced techniques to include laparoscopic ap-proaches.
Finally, we also plan to pursue the establishment of a National Surgical Skills Center to be set up under the auspices of the Philippine College of Surgeons.
All these efforts serve to demonstrate our sincere and unwavering determination to attain our vision of being the leading organization in uplifting the practice of surgery in the country.
Uplifting the practice of surgery in the Philippines
Armando C. Crisostomo, MD, MHPEd, FPCS
Regent-in-Charge (2003) Committee on Surgical Training Philippine College of Surgeons
Preface
• 1st Edition
As mandated by the Philippine College of Surgeons, the PCS Committee on Surgical Training is primarily concerned with the educational welfare of residents. To fulfill this mandate, the project on the Surgical Skills Improvement Program for residents was conceived.
In its original concept, there were two components: 1. Basic surgical skills (for junior residents)
• appropriate selection of needles and sutures • suturing
• knot-tying
2. Advanced surgical skills (for senior residents) • use of staplers and laparoscopy
• stapling techniques • laparoscopic techniques
Why was this program envisioned? What resident needs does it answer?
The training of young surgeons in these very basic surgical skills started during their minor surgery sessions in medical school. As students, they learned scrubbing, preparation of the operative site, suturing and knot-tying.
In clinical clerkship and internship, they had opportu-nities to perform in actual patient situations, suturing different kinds of wounds, but many of them unsuper-vised.
During residency, they assist numerous operations and surgical procedures. Through constant exposure and observation, residents get to absorb the practices, the
A foundation for learning basic surgical skills
habits and preferences of their senior residents and consultants. As they progress to higher levels of training, they indulge in their own series of trials and errors, performing procedures in actual patients.
Conferences and audits have revealed the conse-quences - leaks from repairs, blow-out of anastomoses, disruption of abdominal closures and many others. Undoubtedly, many of these complications are multifac-torial, but a lot of them could be traced to deficiencies in technical expertise.
This manual aims to provide a foundation for learning the most basic surgical skills that all surgeons need to master. These skills are very important compo-nents of patient care. They are carried out regularly, in the day-to-day activities of a surgeon. They must be learned correctly and thoroughly because patient outcomes are influenced by how well these skills are performed.
Jose Y. Cueto, Jr., MD, MHPEd, FPCS
Regent-in-charge (1999) Committee on Surgical Training Philippine College of Surgeons
I. Relevance and Importance
Surgeons who are involved in the training of residents are all too familiar with complications that follow surgical procedures. These are regularly presented in mortality-morbidity conferences and include leaks from simple repairs, disruption of anasto-moses, strictures and stenosis following tight suturing, partial and complete dehiscence of abdominal wall closures and many more.
These complications comprise the evidence of the importance of psychomotor skills, specifically, operative skills. They constitute a very critical part of day-to-day surgical patient care. While it is true that most of them are multifactorial in origin, the most important factor within the control of the surgeon is his technical expertise. Patient outcomes are definitely influenced by how well procedures are performed.
II. Theoretical Basis for Learning Skills A. Fitt’s three-phase theory
Phase 1 Cognitive Phase
This phase involves the initial “intellectualization” process necessary in learning a new task. Both the trainor and trainee try to verbalize what needs to be learned. The trainee has to understand the concepts and principles involved in the task before any performance can be attempted. In surgery, the nature of the technical skills, their indications, applications,
contraindications, complications or consequences are discussed. In this phase, performances of trainees are prone to error. There is, therefore, a need for the trainor to demonstrate how a task should be accomplished.
Phase 2 Fixation or Associative Phase
This phase involves the development of correct pattern of action and behavior. This is established thru practice with regular feedback on the quality of performance. Incorrect practices and steps are identified and rectified. There is gradual elimination of error. This phase lasts a lot longer than the cognitive phase.
Phase 3 Autonomous Phase
This phase is characterized by gradually improving speed and accuracy of performance. The residents develop smoothness and efficiency of movements, with minimal wasted moves, and elimination of unnecessary steps.
During this phase, there is increasing resistance to stress and
Chapter I
Teaching and Assessing Psychomotor Skills in Surgery
Jose Y. Cueto, Jr., MD, MHPEd, FPCS
Objectives of this Chapter
After going through this chapter, the learner is expected to: 1. Understand the importance and relevance of learning and assessing surgical skills
2. Discuss the theoretical bases for learning skills and their educational implications
interference from other activities, and in fact, concurrent activities may be performed.
These characteristics of performance are found in specialists and experts, marked by a high level of proficiency.
III. Educational Implications
A. Need to recognize the phases of learning skills
To make the acquisition of psychomotor skills more effective, the trainors should understand and apply the different phases of learning. Each resident presents with his/her own level of knowledge and competence with regard to a particular skill. The trainor must be able to bring the residents through the different phases of learning.
An educational activity that addresses the cognitive phase of skills learning is the pre-operative conference. Residents go through details in a procedure and verbalize the steps in a particular operation and how complications are to be avoided. Another very important activity is the operative assist. Operations that residents assist in are actually considered “demonstrations” by consultants and senior residents. Needless to say, the residents must be exposed to the correct way of performing different operations and techniques.
The skills that residents learn take years to refine, and are finally incorporated into the autonomous phase of behavior. Once habits become part of autonomous behavior, it becomes very difficult to unlearn them.
B. Need for focus and clarity
In order that lower level residents know what needs to be learned, complex tasks must be broken down into sub-tasks. The residents focus first on learning the simpler sub-tasks before graduating to complex tasks. Ideally, these skills should be learned in the laboratory using simulations, using inexpensive materials or animals. What needs to be learned, how they are to be learned, and how they are to be assessed become clear to the
residents.
C. Need for structure
The old method of “see one, do one” has long been proven to be inadequate and even dangerous. Repeatedly assisting procedures and operations do not automatically mean that trainees will absorb only the good practices of their seniors and superiors. In order to obtain the required level of proficiency in surgical skills, a structured method of teaching and assessment is needed.
Supplementary workshops that include multi-station, hands-on and interactive format will be of great help. The residents rotate through different stations learning about needles, sutures and how to select and use them depending on the clinical situation. Group discussions then follow in order to recapitulate and emphasize the important factors in selection, principles governing their use, and the correct steps that should be fol-lowed.
D. Need for guidance, supervision and feedback
It is during the fixation or associative phase where residents develop their own pattern of action and behavior. They are exposed to different consultants and senior residents who have their own way of performing different techniques. The residents should be able to determine and decide which steps and tech-niques they should adopt, and which ones to reject and avoid.
When residents in lower years are allowed to acquire “bad habits” and incorporate them into their practice, it becomes very difficult for them to unlearn these habits when they reach their senior years. There must, therefore, be adequate guidance and supervision. In addition, timely feedback should be given regarding what needs to be corrected and how they are to be corrected. In this way, only the proper steps are incorporated into the autonomous phase of skills acquisition.
E. Need for simulation and practice
proce-dures on actual patients, they should be given opportunities for simulations. This allows the trainor to make sure that the trainee has mastered the steps in a certain procedure.
During simulation and practice, the deficiencies and errors of the residents should already be determined and corrected. This is to make surgical training safe, and avoid unnecessary complica-tions that may arise from operacomplica-tions and procedures done incorrectly.
IV. Assessing Psychomotor Skills
A. Direct observation with the use of checklists and rating scales
This is the most valid method of assessing how trainees perform. However, this is time-consuming because it requires the presence of trainors all throughout the procedure. This method is process-oriented and assumes that the resident follows the details described in the cognitive phase. The consultant or supervisor assesses how residents select needles and sutures, particularly in the way they are handled.
B. Product evaluation
This is done by inspecting a finished product or a completed task. For example, an anastomosis is inspected by the trainor before the abdomen is closed. This can be reserved for higher level trainees who have already demonstrated mastery of the process.
C. Record review
For audit purposes, the record of procedures and operations are meticulously examined. The materials used (needles and sutures), the steps and their sequences and the over-all operative management are assessed. These are all correlated with the outcomes, such as the presence/absence of complications. However, this method relies heavily on the accuracy and com-pleteness of the operative records.
D. Objective Structured Clinical or Practical Exam (OSCE or OSPE) This method utilizes a number of stations where skills are tested. Skills such as suturing fascia, muscle, skin, intestine and blood vessels are evaluated. Every station has a rater who observes the trainee. With the use of objective checklists and rating scales, the performance is determined to be satisfactory or unsatisfactory. The results are then fed back to the trainees for them to know where they need to improve on.
The use of structured clinical or practical exams ascertain that all residents go through the same stations and the same tasks. This is very difficult to attain in real clinical situations where cases differ in degree of difficulty. Even similar cases of appendicitis present with varying technical difficulties depending on patient habitus, position of the appendix, etc.
REFERENCES
Abbatt F and McMahon R. Teaching Health Care Workers: A Practical Guide; Macmillan Education, London, 1988
Bouhuijs P, et al. The OSCE as a part of a Systematic Skills Training Approach, Medical Teacher, Vol. 9, No. 2, 1987
Crosby J. Learning in Small Groups, Medical Teacher, Vol. 18, No. 3, 1996 Harden RM, et al. Task-based learning: an educational strategy for undergraduate, postgraduate and continuing medical education, Part I, Medical Teacher, Vol. 18, No. 1, 1996
Morgan M and Irby D. Evaluating Clinical Competence in the Health Profession; C.V. Mosby, Co., St. Louis, 1978
A. Direction:
On the blank beside each number, identify and write the phase (Column B) in which the process in Column A takes place according to Fitt’s three-phase theory.
Column A
___1. Performing assisted or supervised operations ___2. Enumerating the steps of an operation in a
pre-operative conference
___3. Learning through demonstration-return demonstration with trainor
___4. Performing operations independently and smoothly ___5. Describing operative complications
Self-Assessment Questions
(Chapter I)
Column B A. Cognitive Phase B. Fixation Phase C. Autonomous Phase
B. Direction:
Column A contains comments from residents in-training. Identify and write on the space before each number, the component under which the problem falls.
Column A
___6. “I have been left on my own to learn new skills” ___7. “I did my first bowel anastomosis in a real patient
because there is no animal laboratory” ___8. “I don’t know what stage of learning I am in” ___9. “I don’t know what to learn”
___10. “No one is correcting my mistakes”
Column B
A. Knowledge of phases of learning B. Focus and clarity
C. Structure
D. Guidance, supervision and feedback E. Simulation and practice
C. Direction:
Identify the most valid and appropriate method of assess-ment for the skills listed. There can be more than one correct answer per number.
Column A
___11. Selection of needles and sutures ___12. Handling of instruments ___13. Knot-tying technique
___14. Quality of anastomosed bowel
___15. Suturing an anastomosis in an animal laboratory
Column B
A. Direct observation of actual performance B. Product evaluation
C. Record review
Chapter II
The Use of Simulation in Surgical Training
Shirard L.C. Adiviso, MD, MHPEd, FPCS
All surgical trainees need a core of basic surgical skills regardless of their specialties. This requires continuous deliber-ate practice to master it and should start early in their training. The trainors have an important role in making this possible. They should describe, demonstrate and arrange practice sessions in teaching these skills.
During the last several years, medical education has swayed away from traditional method of apprenticeship. Most of the surgical skills were previously mastered initially with real patients but is now transferred in “vitro” or simulated venue.
Professional and public concerns in surgical simulation has been initiated by almost identical situation with the airline industry with its desirable reputation for safety and its commit-ment to lifelong training. Actual patient based learning is an important part of advanced surgical training but acquiring technical skills in a venue where patient safety is not at risk is now inevitable.
Simulation (using physical models, computer program or combination of two) provide the opportunity to achieve and evaluate skills through repeated practice within a safe and controlled environment.
Advantages of Simulation
1. The training design can be formulated based on the needs of the learner and not the patient.
2. Since the venue is safe and controlled, learners are allowed to fail and learn from such failures in a way that is unacceptable in a true clinical scenario.
3. Simulators can offer objective evidence of performance using their inherent tracking functions to map learner’s trajectory in detail. Assessment forms are developed for both formative and summative evaluations.
4. The capacity of the simulators to provide ready feedback in digital form offers collaboration in learning.
Classification of Simulations
1. Model Based Simulation – a range of relatively inexpen-sive models or animals are available. Basic procedural skills are taught from simple intravenous insertion to wound suturing. The benchtop models are limited in terms of feedback. This requires comprehensive support from expert mentors.
Objectives of this chapter
After going through this chapter, the learner is expected to: 1. Understand the role of simulation in surgical training. 2. Conduct teaching and learning activities in basic and advanced surgical skills using simulation.
A Simple Taxonomy of Simulators (Medical Education, 2003)
SKILL MANUAL REQUIREMENT EXAMPLES
Precision Placement Direct needle Intravenous needle insertion Instrument to a point Lumbar puncture
Simple Manipulation Guide a catheter Angioplasty
Endoscope Colonoscopy
Ultrasound probe Bronchoscopy
Abdominal ultrasound Complex Manipulation Perform single complex task Bowel/ vascular
anastomosis , MIST-VR, Lap Sim
Integrated Procedure Perform multiple task of Laparoscopy procedure entire procedure Anesthesia simulation
Figure 1- Flexible sigmoidoscopy trainer (Immersion Medical).
Figure 2 - Endoscopic surgery trainer (MIST-VR: – Minimally Invasive Surgical Trainer – Virtual Reality
Figure 3 - Laparoscopy Simulation (LapSim Basic Skills 2.0)
Figure 4- Simulated operating theater with mannequin. 2. Computer Based Simulators (shown below)
1. Hybrid Simulation- combine physical model with comput-ers using realistic interface like instruments and real diagnostics. Kneebone’s 5 Stages of Training Method
1. Watching an animated graphic of procedure.- essential points of technique are shown by animated graphics usually with spoken commentary.
2. Watching a clinical video of the procedure- short clinical video sequences show the techniques performed by an expert on a real patient.
3. Watching the procedure demonstrated on a model-demonstrated a simulated tissue model by the same expert wherein steps can be stopped, started and replayed at will.
4. Doing the procedure on a model- learner carries out procedure on an identical model and practices repeatedly then reviews the techniques.
5. Doing the procedure on a patient under supervision. An experienced colleague or mentor supervised the learner while performing the procedure on a patient.
Kneebone’s Tips in using Simulation and Multimedia 1. Simulation offers means of detaching skills from their clinical context and learning without the pressures of clinical responsibility.
2. The earlier surgical skills training starts, the better. 3. To learn a new motor skill you should see it demon-strated, then practice it repeatedly and receive feedback about your performance.
4. Non-biological simulated tissue allows a range of basic surgical procedure to be learned in skills workshops.
5. Clinical teaching skills are not the same as workshop teaching skills, and new methods of learning require new ways of teaching.
6. To teach skills to complete novices you have to start from
first principles, avoiding any assumption of previous knowledge. 7. It is easy to overestimate the knowledge and skill of any group of learners, especially as they may be embarrassed to admit their ignorance. Assume nothing but go right back to basics – provided you treat the learners with respect, they will value the experience.
8. Do not overestimate the complexity needed in basic surgical skills teaching.
9. Ensure that you are familiar with the procedures you will be teaching and with any models used.
10. Setting up basic surgical workshop requires thought and planning but need not be prohibitively expensive.
11. Learners like a clear framework within which to exercise their navigational freedom.
12. Make the teaching aim clear from the onset. Encourage learner to repeat procedure till they become proficient.
REFERENCES
Anastakis,Dmitri et al. Assessment of Technical Skills Transfer from Bench Training to Human Model. The American Journal of Surgery. Vol.177 Feb.1999
Cauragh,James et al. Modelling Surgical Expertise for Motor Skills Acquisition. The American Journal of Surgery. Vol 177, Apr.1999
Connor, Michael et al. A Computer Based Self-Directed Training Module for Basic Sutures. Medical Teacher Vol. 20 no.3, 1998.
Kneebone, R.L. Twelve tips on Teaching Basic Surgical Skills Using Simulation and Multimedia. Medical Teacher Vol. 21 No. 6, 1999.
Kneebone,Roger . Simulation in Surgical Training:Education Issues and Implications. Medical Education. Vol 37. 2003
Rogers,David et al. Computer Assisted Learning Versus A Lecture and Feedback Seminar for Teaching Basic Surgical Skills. The American Journal of Surgery. Vol 175. June 1998
Wigton, Robert. See One, Do One, Teach One. Academic Medicine. Vol. 67 no. 11, Nov. 1992.
Direction:
On the blank beside each number, identify the simulator used in the Column B to the examples of skills in Column A.
Column A
____ 1) Intravenous needle insertion ____ 2) Colonoscopy ____ 3) Vascular anastomosis ____ 4) Laparoscopy Procedures ____ 5) Abdominal Ultrasound Column B A ) Simple manipulation B ) Precision Placement C ) Integrated Procedure D) Complex Manipulation
Sutures are fibers of strands of a material used for sewing tissues to help wound healing by surgically approximating its edges. The material used to close blood vessels to achieve hemostasis is called ligature.
The first suture materials were used between 2500 and 3000 BC as documented by Egyptian papyri and they consisted of fibers of plant origin, leather, animal tendons and parchment strips. However, it was only in 1860 when Joseph Lister intro-duced carbolic catgut, the first suture material specifically for surgical use. Eventually other materials were introduced for surgical use such as linen, silk, celluloid, horsehair, wire, etc.
Synthetic materials were first used in the 1930’s with the introduction of polyvinyl alcohol. As the 20th century comes to a close, manufacturers of sutures have reached a stage of signifi-cant refinement in suture materials such that certain suture materials are used only for specific surgical procedures.
Suture materials come in different sizes, corresponding to the
diameter of the suture and these sizes are stated in a numerical fashion. The greater the number of 0’s, the smaller the size the suture strand is. Thus, a 6-0 suture is smaller than the diameter of a 2-0 suture.
Suture materials are generally classified as being absorbable or non-absorbable. (Refer to Table A: Classifica-tion of Suture Materials.) Absorbable sutures are those sutures which are broken down or degraded by hydrolysis or digested by enzymatic processes. Non-absorbable sutures, on the other hand, are those which are not arrested by either enzymes or tissue fluids.
The most frequently used absorbable non-absorbable suture materials are the following:
Absorbable Sutures
1. Plain Catgut Plain catgut is derived from the collagen of small intestine, either the serosal layer of cattle or the submucosal layer of sheep. In tissues, plain catgut loses much of its tensile strength at the end of one week. It is absorbed shortly there after and thus, is recom-mended for use in situations in which a suture is needed only during the first week of healing as in soft tissues like subcutane-ous tissue and ligature purposes.
Chapter III
Suture Materials
Jose Antonio M. Salud, MD, FPCS and Jerome G. Baldonado, MD, FPCS Jose Joey Bienvenida, MD, FPCS
Objectives of this Chapter:
After going through this material, the learner is expected to: 1. Analyze the different types of sutures and their character-istics.
2. Discuss the newer “suture materials” and their characteris-tics.
3. Discuss guidelines in choosing a suture material based on its biological behavior and mechanical performance.
Table A – Classification of Suture Materials
Based on Origin
Suture Material Origin
Natural Animal
Catgut Submucosa of sheep intestine or serosa of beef intestine
Silk Raw silk spun by silkworm
Vegetable
Cotton Cotton Plant
Mineral
Steel Specially Formulated iron-chromium-nickel-molybdenum alloy
Silver Silver
Synthetic
Polyglactin 9101 Copolymer of glycolide and lactide with polyglactin 370 and calcium stearate, if coated
Polyglycolic Acid Homopolymer of glycolid
Poliglecaprone 25 Copolymer of glycolide and epsilon-caprolactone Polyglyconate Copolymer of glycolide and trimethylene carbonate Polydioxanone Polyester of poly (p-dioxanone)
Poly (L-lactide/glycolide) Copolymer of lactide and glycode with caprolactone and glycolide coating
Nylon Polyamide polymer
Polyester Fiber Polymer of polyethylene terephthalate (may be coated)
Polypropylene Polymer of propylene
Poly (hexafluoropropylene-VDF) Polymer blend of poly (vinylidene fluoride) and poly (vinylidene fluoride-cohexafluoropropylene) Based on BEHAVIOR Absorbable Non-Absorbable Catgut Cotton Polyglactin 910 Steel Silk
Polyglycolic Acid Silver
Poliglecaprone 25 Nylon
Polyglyconate Polyester Fiber
Polydioxanone Polypropylene
Poly (L-lactide/glycolide) Poly (hexafluoropropylene-VDF)
Based on STRUCTURE
2. Chromic Catgut This suture material is actually similar to plain catgut except that it is treated with chromate compounds, which results in a stronger and more slowly absorbed suture. Thus, the loss of tensile strength takes a little longer, about double the time it takes for plain sutures to lose their own. However, the absorption of chromic is dependent on environmental factors in the tissues. When used to suture the stomach, the presence of acid hastens the absorption. This should not be used when extended approxi-mation of tissues under stress is required, as in fascia. Both plain and chromic catgut sutures may stimulate a considerable inflammatory reaction during the absorptive phase and should, thus not be used in areas such as the peritoneum.
3. Polyglactin This is a synthetic braided suture whose raw material is a copolymer of glycolide and lactide. Most absorbable in synthetic sutures, polyglactin included, are hydrolyzed during absorption rather than being broken down enzymatically (as with the natural absorbable sutures). In hydrolization, water gradually penetrates the suture filaments causing the breakdown of the suture’s polymer chain which results in lesser degree of tissue reaction following tissue implantation. 75% of the strength of this suture is retained at 14 days, and about 50% is retained at 21 days. 100% loss in tensile strength is noted by the 32nd day. Absorption is complete at about the 56th or the 70th day.
4. Polyglycolic Acid This synthetic braided suture is reduced by the hydrolysis to glycolic acid. Like most synthetic sutures, the inflammatory reaction that results from its breakdown is only minimal. Its tensile strength is completely lost by the 30th day. Complete absorption occurs about the 90th day.
5. Polydioxanone This is a synthetic monofilament absorb-able suture composed of the polyester of p-dioxa-none. It takes longer for its tensile strength to be reduced as well as for its absorption to be com-pared with the two previously mentioned suture materials. In vivo studies have shown its tensile strength to be at about 70% at 14 days and 50% is retained at 28 days. Absorption starts close to the 90th day and is complete at 6 months time.
6. Poliglecaprone This is a mono-filament suture whose tensile strength in the first week is high but rapidly reduces soon after. Studies have shown its tensile strength to be about 70% at the end of the first week but is down to 30-40% by the end of the 2nd week. It is thus recommended for use in situations wherein the surgeon requires a high initial tensile strength as in subcuticular wound closures. Absorption is complete in 90-120 days.
Non-absorbable sutures
1. Silk
By far, still the most commonly used suture material, silk is a protein filament produced by silk-worms. As with most braided sutures, silk holds knots well. However, silk loses its tensile strength when exposed to moisture and should be used dry. Silk loses much, if not all of its tensile strength within a year. Although classified as a non-absorbable suture, silk can actually be absorbed slowly but the absorption rate is variable.
2. Cotton
This is a commonly used braided non-absorbable suture much like silk. It stimulates an inflammatory reaction greater than that of silk and other sutures is that this material is relatively cheaper.
3. Nylon
This particular non-absorbable suture comes in a monofilament and braided form. This suture is characterized by its high tensile strength and extremely low tissue reaction. The loss in tensile strength is in the range of 15-20% per year by hydrolysis. As with most monofilament sutures, nylon sutures require more throws to securely hold the knots in place. The braided variety, on the other hand is very similar in characteristic to silk but has considerably less tissue reaction.
4. Polypropylene Polypropylene is a non-absorbable synthetic monofilament suture. This suture’s tensile strength retention is indefinite and is a suture that is encapsulated by tissues when implanted thus resisting tissue degradation. Because of these characteris-tics, it is a suture that is widely used in virtually all specialties.
5. Polyester This suture was the first synthetic suture material shown to last indefinitely in tissues. Like polypropylene, poly-esters sutures are encapsulated by tissues and thus resist tissue degradation. 6. Wire/Stainless Steel/Titanium
A very strong suture material that produces little loss of tensile strength, wire has been used for many years and is a popular suture for a variety of operations (thoraco-cardiovascular, orthopedics, neurosurgery). Tissue reaction is minimal. However, it is difficult to handle and may be easily palpated by the patient.
Table B – Suture Materials and Characteristics
T A B L E O N S U T U R E C H A R A C T E R I S T I C S
T i s s u e Number of Absorbability Absorption Inflammatory Knot Security of Origin strands Rate reaction (minimum #
of knots)
Plain Catgut Collagen of Monofilament Absorbed by Complete ++ 2 small bowel of Enzymatic within 70 days
cattle & sheep Proteolysis
Chromic Catgut Collagen of Monofilament Absorbed by Over 90 days ++ 2 small bowel of Enzymatic
cattle & sheep Proteolysis
Polyglactin Copolymer of Multifilament & Absorbed by Complete in + 2/5 lactide & Monofilament Hydrolysis 56-70 days
glycolide coated (size 10-0 with polyglactin only) 370 & calcium
stearate
Polyglycolic acid Glycolic acid Multifilament Absorbed by Complete + 2
polymer Hydrolysis in 90 days
Poliglecaprone Copolymer of Monofilament Absorbed by Complete -/+ 5 glycolide and Hydrolysis in 91-119
epsilon- days
caprolactone
Polydioxanone Polyester Monofilament Absorbed by Complete -/+ 5
polymer Hydrolysis in 180 days
Silk Silkworm Multifilament Non- N/A + 2
absorbable
Cotton Cotton Plant Multifilament Non- N/A ++ 2
absorbable
Nylon Long-chain Monofilament Non- N/A -/+ 2/5
polymers of absorbable
nylon
Polypropylene Crystalline Monofilament Non- N/A -/+ 5
stereoisomer of absorbable polypropylene
Polyester Polymer of Multifilament Non- N/A -/+ 2
polyethylene absorbable terephthalate
Wire/Stainless 316L stainless Multi- & Non- N/A -/+ Steel/Titanium steel Monofilament absorbable
MESH
Surgical mesh materials are more commonly used to repair fascial defects. Its use in inguinal herniorrhaphies was even made more popular in the advent of laparoscopic herniorrhaphy techniques. Meshes may be non-absorbable or absorbable.
Non-absorbable Meshes
Most common types of materials used in non-absorbable meshes are polypropylene, polyester (macroporous structures) and polytetrafluroethylene (PTFE) (microporous structures).
Polypropylene may be monofilament or multifilament. Both exhibit high burst strength. It is knitted in such fashion as to interconnect each monofilament fiber and provide unidirectional elasticity. This mesh is porous.
Absorbable Meshes
Polyglycolic acid and Polyglactin inert knit meshes are stretchable. This mesh is mainly used to support the small intestine and to set as a sling to protect the area from radiation associated small bowel injury. It has 3 days tensible strength retention and is absorbed within 60-90 days.
Surgical Staplers Modern surgical stapling devices and techniques were first developed in the Soviet Union in the 1950’s through the work of the Scientific Research Institute for Experimental Surgical Apparatus and Instruments in Moscow.
These instruments have wide application in various fields of surgery facilitating ligation and division, resection, anastomosis and skin and fascial closure. These staplers significantly reduce operating time, time under anesthesia, blood loss, tissue manipulation and trauma thus facilitating postoperative healing. Edema and inflammation associated with manual suturing is significantly reduced with the use of staplers and anastomoses appear to function sooner as compared with manual suturing techniques. The stainless steel staples that are used are virtually inert producing minimal tissue inflammation and minimal tissue compression. However, with the use for staplers for skin repairs, the closure may be less meticulous. Another disadvantage of staplers is that it may interfere with computed tomography and magnetic resonance imaging.
Skin Adhesives
Designed to close skin wounds and lacerations, tissue adhesives is a non-pigmented medical grade adhesive made of n-butyl-cyanoacrylase. Applied to wound edges, to hold them together and may provide wound healing similar to skin sutures.
called topical skin adhesives, as exemplified by DERMABOND(r). This is a non-absorbable sterile violet-colored liquid
(2-octylcyanoacrylate) that is used primarily for easy approximation of skin edges.
Cyanoacrylate adhesives were first described in 1949 and there first reported used as clinical adhesives was for 10 years later. However, the use of these initial cyanoacrylates
(butylcyanocrylate) was limited due to certain physical properties. Octylcyanoacrylate is a new-generation medical-grade adhesive that has addressed these limitations. It is simply applied over the apposed wound edges and allowed to set within 45-90 seconds after application. An adhesive waterproof film is then formed over the wound. It does not require applica-tion of local anesthetics nor is there a need to use instruments and sutures.
Octylcyanoacrylate tissue adhesive can replace skin sutures on virtually all facial lacerations and properly selected extremity and torso lacerations. It is not recommended for use on hands and over joints since repetitive movements and washing the adhesives may peel off with the top layer of epidermis in only a few days, before complete healing has occurred. It is ideal for use in children and in case where rapid skin closure essential. After 5-10 days, the adhesive film sloughs off as the skin starts to re-epithelialize. it has been deemed an effective and reliable method of skin closure for many wounds, yielding similar cosmetics results to closure with subcuticular sutures and is a faster method of skin closure than suture.
Furthermore, cyanoacrylate adhesives also have antimicro-bial properties against gram-positive organism and may
decrease wound infections. However, they have a lower tensile strength than sutures.
Guidelines in Choosing a Suture Material • TABLE C
IDEAL SUTURE CHARACTERISTICS
1. High tensile strength 2. Sterile
3. Ease and security of knotting 4. Ease of handling
5. Inert (The ideal suture material would cause the least tissue reactivity.)
6. Non-toxic, non-allergenic (both the suture and its components when metabolized by the body) 7. Small size
8. Predictable performance
9. Smooth surface avoiding necrotic tissue, clots and bacteria to adhere
10. Should keep its physical characteristics as long as necessary
11. Cost effective
The selection of suture materials is generally based on its biological interaction with the wound and its mechanical characteristics. Whatever suture material is used for a particular procedure, the following guidelines should be considered:
1. Select the finest suture consistent with the tissues to be approximated.
2. The suture material should have adequate tensile strength and maintain it until its purposed is served.
3. Choose a suture that would produce the least tissue reaction.
4. Select sutures with the least risk for bacterial proliferation. 5. Select sutures that are pliable, easy to handle and able to maintain knot security .
These principles are important to remember in the choice of sutures based on their physical properties:
1. Sutures should be at least as strong as normal tissues through which they are placed.
2. Suture strength must be maintained until the wound gains maximum strength.
3. Tissue reaction to sutures should not prolong the healing process.
To apply these principles, one must have information regarding the normal strength of tissues, the rate at which injured tissues regain strength, the strength of different sutures, the rate at which sutures lose strength and the interaction between sutures and tissues.
• TABLE D
HIERARCHY OF BIOLOGICAL INERTNESS
(from highest to lowest)
Highest Plain Cutgut Reactivity Chromic catgut
Linen-Cotton Silk
Braided Uncoated polyester Braided Uncoated Polyamide Braided Coated Polyamide Synthetic Absorbable Monofilament Polyamide Monofilament Polyester Polypropylene Lowest Steel Reactivity Titanium
Normal Strength of Tissue
Experimental data regarding human tissue strength are limited. However, a number of papers in the literatures provide data about other animal tissues. Tissue strength is determined in
several ways:
1. Tensile strength - refers to load applied per unit of cross section area in lbs/in2 or kg/cm2
2. Breaking strength - measurement of force required to break a wound without regard to its dimension
3. Bust strength - amount of pressure necessary to rupture a viscus
Tensile strength is the preferred measurement for homog-enous materials (ex.,. sutures). For heterogeneous materials (ex., skin), the breaking strength is more practical to use. For hallow organs (ex., intestines), burst strength is the more appropriate measure. From the meager data available, it can be shown that that regardless of the species, the relative strength of tissues to each other are similar. Animal studies show that the stress needed for a suture to pull out from the following tissues are:
a. Skin -- 0.9 lbs. b. Fat -- 0.44 lbs. c. Fascia -- 8.3 lbs. d. Muscle -- 2.8 lbs. e. Peritoneum -- 1.9 lbs. f. Viscera -- 2.19 lbs. (stomach) -- 3.7 lbs. (rectum)
Above the limits of the strength of the tissue, no advantages gained by using a larger or stronger suture to hold the wound edges together. These data on relative strength are useful only if considered in relation to the rate at which wounds in these tissues regain strength.
Variations in Healing Rate
A wound rarely, if ever, attains the same strength as unin-jured tissue. The gain in strength varies from tissue to tissue.
Skin -- 70% strength at 3-4 months.
Fascia -- 50% of original strength at 50 days; 80% at 1 year. Muscle -- 80% strength at 10-14 days.
REFERENCES
Edlich RF, Woods JA, Duke DB. Scientific Basis of Wound Closure Techniques. Dannenmiller Memorial Educational Foundation, San Antonio, Texas. Ethicon Wound Closure Manual, Ethicon, Inc., 1994
Maw JL, Quinn JV, Wells GA, Ducic Y, Odell PF, Lamothe A, Brownrigg PJ and Suctliffe T. A Prospective Comparison Of Octylcyanoacrilate Tissue Adhesive & Sutures for the Closure of Head and Neck Incisions; Journal of Otolaryngology, 1997, Vol.26, 1;26-30
Quinn J, Wells G, Sutcliffe T, Jarmuske M, Maw J, Steill I and Johns P. A Randomized Trial Comparing Octylcyanoacrylate Tissue Adhesive and Sutures in the Management of Lacerations; JAMA, 1997, Vol. 277, 19:1527-1530
Sabiston DC, Jr. Textbook of Surgery, The Biological Basis of Modern Surgical Practice, 15th ed., WB Saunders Co., 1997
Wound Closure In the Operating Theatre, B Braun Melsungen AG
Zinner MJ, Schwartz SI, Ellis H, Ashley SW & McFadden DW. Maingot’s Abdominal Operations, 10th ed., 1997
1. Which of the following sutures are considered non-absorb-able? a. Polyester b. Polydioxanone c. Polyglactin d. Polyglycolic acid e. Poliglecaprone
2. Which of the following suture material has an indefinite tensile strength? a. Nylon b. Silk c. Polyester d. Polypropylene e. Polyglactin
3. Which of the following is a characteristic of skin adhesives? a. Interferes with MR imaging
b. Consumes more time compared to sutures
c. Yields similar cosmetic results as with subcuticular sutures d. Is used for joints lacerations
e. Produces pain on application
Self-Assessment Questions
(Chapter III)
4. Which of the following sutures loses tensile strength the longest? a. Chromic catgut b. Polyglactin c. Polyglycolic acid d. Polydioxanone e. Poliglecaprone
5. Which suture material is most suitable in closing the fascia of the abdominal wall?
a. Plain catgut b. Chromic catgut c. Polydioxanone d. Poliglecaprone e. Staplers
6. Which of the following suture materials exhibits the highest inflammatory tissue reaction?
a. Polypropylene b. Polyglactin c. Chromic d. Silk e. Polyester
7. Based on their physical properties, what suture will be good choice to approximate fascia after a contaminated operation?
a. Plain catgut b. Polypropylene c. Silk
d. Chromic catgut e. Cotton
8. The following statements regarding the physical properties of sutures and tissues are true EXCEPT?
a. Above the limits of normal tissue strength, there is no advantage with the use of a larger or stronger suture
b. A suture should hold injured tissues in apposition until the healing process to withstand stress without mechanical support
c. Foreign bodies like sutures cane lead to the development or persistence of local infection and therefore, should not stay longer than their supported use
d. From the practical stand point, tensile strength is more important than breaking strength
Objectives of this Chapter
After going through this chapter, the learner should be able to: 1. Analyze the factors involved in needle selection. 2. Describe the characteristic of the surgical needle. 3. Identify the common types and code names of the locally available needles.
Factors in the Selection of Needles
When considering the ideal surgical needle for a given application, the type of tissues being approximated should be considered: they should be altered as minimally as possible by the needle. The only purpose of the needle is to introduce the suture into the tissues. The needle should also be large enough and of appropriate size, shape and design in order to provide precise and efficient suturing. There are five basic requirements that must be met in proper needle selection. The needle must be:
1. Able to carry suture material through tissues with minimal trauma.
2. Sharp to overcome tissue resistance.
3. Rigid to resist bending but flexible to prevent breaking . 4. Sterile and corrosion-resistant to prevent introduction of microorganisms or foreign bodies into the surgical site, and
5. Of appropriate size, shape and design.
The surgical needle has evolved with the history of surgery
itself. The first needles were either closed-eyed or the so-called French-eye needles requiring the scrub nurse to thread the suture into the eye of the needle. The double strand of the suture that results from threading and the increase in diameter of the needle because of the presence of the eye, causes additional trauma to tissues and in anastomotic procedures, may lead to leakages.
Moreover, threading is time consuming and the needles are difficult to prepare during surgery. A weak point is created near the eye that could lead to needle breaks and even to rusting. During operations in deep confined areas, eyed needles may become unthreaded. Theoretically, it is more difficult to retrieve them when accidentally dropped inside body cavities without the suture. Because of these, there was a gradual reluctance both in the use and manufacture of eyed surgical needles and favor shifted towards swaged surgical needles.
Anatomy of the Surgical Needle
Regardless of its intended use, every surgical needle has three basic components:
1. The point 2. The body
3. The attachment end (swaged or eyed)
Chapter IV
Surgical Needles
Cenon R. Alfonso, MD, FPCS & Nilo C. de los Santos, MD, FPCS Renato Cirilo A. Ocampo, MD, FPCS
A. Needle Point
The point extends from the extreme tip of the needle to the maximum cross section of the body. Each specific point is designed and produced to the required degree of sharpness to
smoothly penetrate the type of tissue to be sutured. 1. Tapered
The body of the needle tapers to a sharp point at the tip. The taper point needle is often preferred where the smallest possible hole in the tissue and minimal tissue trauma is desired. This is particularly indicated in intestinal anastomosis. It is also ideal for approxi-mation of the peritoneum, fascia and subcutaneous tissues.
Examples are needles code-named CT-1 and SH. 2. Blunt
A rounded blunt point that does not cut through tissues is used for penetrating friable, parenchymal and vascular tissues like the liver, spleen or kidneys. An example is the BP-1 needle.
3. Reverse Cutting
These needles have a cutting edge in the outer convex curvature of the needle. This cutting edge may extend from the point of the needle down to the swaged area. The cutting edge may also extend only down to 1/3 of the distance to the swaged area. This type is most useful in plastic surgical procedures. These types of needles are coded PS- 2 and OS-8. The latter type is also indicated in the closure of skin and various plastic surgery applications and
other orthopedic procedures. 4. Taper Cut (Trocar point)
This is a blend of the combined features of the reverse cutting and the taper point needles. Three cutting edges extend approximately 1/ 32 inches back from the point. All three edges of the point are sharpened to provide uniform cutting action. It easily penetrates dense tough tissues. This type is used for sclerotic or calcified tissues and for heavy fibrous tissue such as the fascia. A typical example is V-40. 5. Conventional Cutting Edge
The cutting sharp edge is in the concave curvature of the needle. This is ordinarily used in common plastic surgery procedures and in closure of superficial wounds and incisions. An example is the PC-5 needle.
B. Needle Body
The portion between the point and the swage of a needle is called its body. This is the grasping area of the needle holder. C. Attachment End
1. Swaged
This is the area in which the suture is attached to the needle. It is of specific importance to the needle-suture relationship.The ideal swage area diameter is a one-to-one suture-needle ratio so that the more exact the sizes correspond to each other, the lesser the damage to the tissues. On the other hand, the bigger the ratio, the greater unnecessary tissue damage is produced. In cases of
bowel anastomosis, this ratio is most crucial in preventing needle puncture leaks. Suture attachments to the needle are most commonly done in two ways:
Channeled Needles
A channel is developed in the swage area and the suture is placed or clipped in the channel. Pressure is applied to close the channel around the suture in order to hold it tightly.
Drilled Needles
Mechanically drilled. A hole is drilled into the swage area of the needle and the end of the suture is placed inside the hole. The hole is then crimped a little in order to secure the suture end.
Laser-drilled Needles
A feature provided where the swage area is laser-drilled to achieve the closest one-to-one needle-suture ratio. Laser-drilled needles are currently available among cardiovascular products. It has the advantage of a tapered swage which in turn provides a smoother transition from needle to suture. In addition, a laser-drilled needle allows the so-called extended side flattening, a design that adds strength and resistance to bending.
2. Closed Eye
Similar to a household sewing needle, the shape of the closed eye may be round, oblong or square.
3. French Eye
These needles have a slit from inside the eye to the end of the needle with ridges that catch and hold the suture in place.
4. Control Release Needle Suture These needle sutures allows easy detachment of the needle from the suture when desired by the surgeon. This allows rapid placement of sutures in succession, reducing operative time.
D. Chord Length
The chord length is defined as the straight line distance from the point of a curved needle to the swage. This varies from 2 mm. to more than 5 cm. Length is a determining factor in the width of the bite taken by the needle. Chord length comparison between the CT-1 needle and the TP-1 needle will make the biggest difference in the width of the bite.
E. Needle Diameter
This refers to the gauge or thickness of the needle wire. Needle diameter varies from 30 microns to 56 mil (.056 inch). The diameter equals the size of the needle tract.
F. Needle Radius
If the curvature of the needle were to con-tinue to make a full circle, the radius of the curvature is the distance from the center of the circle to the body of the needle. This varies from 1 mm. to 1 1/8 inches. The curved needle is always thought of as part of a circle.
G. Needle Shape
Needles are available in various shapes to accommodate the desired “turnout” from different tissues. The shape of the needle remains consistent regardless of size. For example, although a
TF needle is significantly smaller in size than an XLH, they are both 1/2 circle needles. The following are the usual needle shapes used:
1/4 circle (TG) 3/8 circle (P) 1/2 circle (CT) 5/8 circle (UR)
straight or Keith needle
TG Needle: Their use is often limited to ophthalmic and microsurgical procedures. Size and depth of the area to be sutured are small and shallow.
P Needle: This is the most commonly used curved needle. It can be easily manipulated in relatively large and superfi-cial wounds such as closure of the dermis with slight pronation of the wrist. Because of a large arc of manipula-tion required, 3/8 circle needles are awkward to use in deep cavities such as the pelvis or in small, cramped areas with difficult access.
CT Needle: it is relatively easy to use in confined areas and difficult to reach locations though it requires more pronation and supination movements of the wrist than a 3/8 circle needle.
UR Needle: the tip of a 1/2 circle needle such as the CT-1 can become obscured by other tissue deep in the pelvic cavity. When this occurs, the surgeon may have difficulty locating the point of the needle in order to pull it through the tissues. A 5/8 circle needle such as the UR-4 is most advantageous in these situations.
H. Needle Length
This is the distance between the point and the swage measured along the body of the needle.
Needle Arming
The needle should be grasped in the area about 1/4 to 1/2 the distance from the swaged area to the point. It should be held on securely at the tip of the needle holder’s jaws. There are various types of holders to accommodate different needles and for different locations and tissues. The following factors must influence the needle holder’s choice:
1. Security of the needle in the holder 2. appropriate size for specific needles 3. appropriate length for specific procedures Single Versus Double Armed Suture
Commonly used sutures have one swaged-to-suture strand. Situations do arise wherein there is a need to place a suture at a midpoint and suturing must continue on both sides. The typical examples are vascular anastomoses. In such situations, it is ideal to use a double-armed suture. This is a suture strand with a needle swaged at each end. If the strand is divided into halves, this results into two single-armed sutures that can be used individually. An example is the CT-1, CP-1 double armed needle suture combination for episiotomy repair.
Characteristics of Surgical Needles and their Clinical Impor-tance
Trauma to the tissue edges that are sutured together during surgical procedures, among other factors, theoretically spells an integral part of the outcome of wound healing. The relation-ship is, in fact, indirectly proportional. The greater the trauma induced, the poorer the outcome. If it were an intestinal anasto-mosis, for example, excessively traumatized ends may result to a poorer blood supply, affecting the integrity of the intestinal layers, and complete apposition. Subsequent wound healing processes therefore are compromised. It appears that the choice of needle, suture material, as well as the technique of apposing
and handling tissues together are important factors in order to achieve the best outcome with the least tissue damage. There-fore, surgical needle design, characteristics and usage play significant roles in the art and science of surgery.
Sharpness and Pointedness
Sharpness, in contrast to “pointedness,” refers to the condi-tion of the blade of cutting surgical needles. This is obviously not applicable among needles that are not flattened at the distal body and point. (Needles that are round may either be pointed or blunt at the opposite end of the swage). But cutting needles can become blunted both at their point and at the flattened body mainly due to repeated usage or friction against hard tissue and foreign bodies. There are round needles that are created with blunted points for the purpose of passing sutures through solid organs like the liver and spleen. But it is desirable to always use sharp cutting needles when indicated.
Sharp cutting needles create clean, minute lacerations through tissues and cut muscle fibers. Pointed round needles, however, just create puncture wounds and merely split muscle fibers rather than cut them. Minute lacerated wounds created by using cutting needles may completely tear at their corners when subjected to tension. Literally, they tend to extend easily to a rent. Punctured wounds by nature are not prone to renting and are easily plugged. Thus, among hollow organs like viscus and blood vessels, pointed round needles are favored.
On the other hand, tough tissues like the epidermis and the subcuticular layers are difficult to traverse with pointed needles. Thus, the cutting action of a flattened needle is desirable. These tissues are not prone to lacerations or renting due to its fibrous content.
Atraumatic Needles
This is a misnomer. All needles cause some form of trauma to sutured tissues. So-called atraumatic needles cause the least injury. This is so because of the following characteristics:
1. Small diameter,
2. The size of the swage is the same as the size of the body, 3. The suture material is of the same diameter as the
needle, and
4. There is no eye. With the smooth passage of the needle and the suture through the tissue, the injury to the edges are minimized.
Rigidity versus Flexibility
Rigidity of surgical needles is dependent on the diameter, composition of the metal alloy used and the temperature by which they were set (tempered). This is, therefore, affected by its frequency of being subjected to autoclaving. Rigid needles are necessary in suturing bones, cartilage and very tough fascia. Hernia needles, sternal needles and needles used to wire bones together are some examples. Rigid needles tend to break when too much shearing pressure is applied unlike flexible needles. Flexible needles, however, tend to withstand a greater shearing force or even bending but generally not in acute angles.
Rust-free and Corrosion-free Needle Material
Stainless steel needles are generally rust- and corrosion-free. Most surgical needles are no longer made of lesser quality. Their flexibility, inertness and smoothness are other characteristics that are most desirable in surgical needles for medical grade usage. Other metal alloys are even better but their cost is prohibitive.
Needle Weakpoints
Eyed needles break most frequently at the junction of the swage and the body. This is so because of the tension created by the angle of the needle against the suture. In the process of passing a curved needle through tough tissues, the straight portion of the eyed needle may be pulled by the surgeon at an acute angle against the tissue. In other situations, the surgeon may load the needle at this weak point and apply the drive force through the tissue.
Another weak point, particularly among atraumatic round needles, is the junction of the body and the point. The surgeon may force the body of the curved needle through the tissues at
Self-Assessment Questions
(Chapter IV)
1. Which of the following needles are most applicable when suturing deep in the pelvic cavity?
a. 1/4 circle b. 3/8 circle c. 1/2 circle d. 5/8 circle e. straight needle
2. For suturing liver lacerations, the surgical needle to use is: a. CT series
b. SH series c. BP series d. TP series e. V-4 needles
3. The surgical needle for microsurgical procedures is: a. UR-4 d. V-4
b. PS-1 e. CT-1 c. XLH
4. Surgical needles most commonly used for bowel anastomosis is: a. Reverse cutting b. Circle tapered c. Cutting tapered d. Rounded blunt e. Conventional cutting
5. The needle to use in the primary repair of a complete but clean traumatic transection of the ureter is:
a. MO d. X-1 b. PS e. RB-1 the same angle as the point rather than smoothly glide the body
according to its curvature. By its structure, the tapered point and the full diameter body creates a weak point at their junction considering the tension these two areas will undergo at different angles. Besides, the force exerted by the needle holder at the body will exacerbate the above situation.
REFERENCE
Objectives of this Chapter
Proper knot tying is one of the essentials in the performance of a good surgical procedure. The art and science of surgery requires that knots be tied not only with dexterity and speed, but they should be placed with the right amount of tension for proper approximation of tissues and ligation of blood vessels. At the end of this chapter, the learner should be able to:
1. Discuss the general principles of knot tying
2. Describe the common techniques of knot tying which can be applied to the different types of surgical procedures.
3. Perform the common techniques of knot tying which can be applied to the different types of surgical procedures.
General Principles of Knot Tying
In knot tying, general principles to be adhered to are the following:
1. When handling sutures, one must take care to avoid damage to the suture material.
2. In tying any knot, friction between strands must be avoided to prevent weakening of the integrity of the suture.
3. Sutures should be tied with appropriate tension to prevent tissue strangulation or gaping of edges.
4. The completed knot must be secure.
5. For monofilament sutures, at least 5 throws are required to securely hold the knots in place as less than this may result in a tendency for the knots to loosen. Additional throws do not add to the strength of a properly tied knot.
6. For braided sutures, two throws are required to securely hold the knot.
7. Sutures must be cut to their proper length.
Chapter V
Knot Tying
Jose Antonio M. Salud, MD, FPCS Miguel C. Mendoza, MD, FPCS
Knot Tying Techniques
Square Knot (Two-Hand Technique)
4. Purple strand crossed over white and held between thumb and index finger of left hand.
3. Left hand turned inward by pronation, and thumb swung under white strand to form the first loop.
2. Purple strand held in right hand brought between left thumb and index finger.
1. White strand placed over extended index finger of left hand acting as brdige, and held in palm of left hand. Purple strand held in right hand.
12. The final tension on the final throw should be as nearly horizontal as possible.
11. Horinzontal tension applied with left hand away from and right hand toward the opera-tor. This completes the second half hitch. 10. Left hand rotated inward by pronation with thumb carrying purple strand through loop of white strand. Purple strand is grasped between right thumb and index finger.
9. By further supinating left hand, white strand slides onto left index finger to form a loop as purple strand is grasped between left index finger and thumb.
7. Left index finger released from white strand and left hand again supinated to loop white strand over the left thumb. Purple strand held in right hand is angled slightly to the left. 6. Purple strand released by left hand and grasped by right. Horizontal tension is applied with left hand toward and right hand away from operator. This completes first half hitch.
5. Right hand releases purple strand. Then left hand supinated, with thumb and index finger still grasping purple strand, to bring purple strand through the white loop. Regrasp purple strand with right hand.
8. Purple strand brought toward the operator with the right hand and placed between left thumb and index finger. Purple strand crosses over white strand.
Knot Tying Techniques
Square Knot (Two-Hand Technique)
