CLINICAL PROFILE OF INGUINAL HERNIA IN INFANTS
Dissertation submitted to
The Tamil Nadu Dr.M.G.R Medical university, Chennai In partial fulfillment of the requirements for the degree of
Doctor of Medicine in Paediatrics
Under the guidance of DR. K. NEELAKANDAN.,
Department of Paediatrics
P.S.G Institute of Medical Sciences &Research, Coimbatore Tamil NaduDr.M.G.R Medical University, Chennai
CERTIFICATE BY THE HOD AND DEAN OF THE INSTITUTION
This is to certify that the thesis entitled “CLINICAL PROFILE OF
INGUINAL HERNIA IN INFANTS” is the bonafide original research work of Dr. SHYAM K, has been done under the guidance of Dr. K.NEELAKANDAN
Professor and Head of the Department of Paediatrics PSG IMS&R, Coimbatore in
fulfilment of the regulations laid down by The Tamilnadu Dr.M.G.R Medical
University for the award of MD degree in Paediatrics.
Dr. K.NEELAKANDAN Dr.RAMALINGAM
Professor Dean
Head of the Department PSGIMS&R
Department of Paediatrics
CERTIFICATE
This is to certify that the thesis entitled “CLINICAL PROFILE OF
INGUINAL HERNIA IN INFANTS” is the bonafide original research work of
Dr. SHYAM K, has been done under my guidance and supervision in the Department of Paediatrics, PSG IMS&R, Coimbatore in fulfilment of the
regulations laid down by The Tamilnadu Dr.M.G.R Medical University for the
award of MD degree in Paediatrics.
DR. K.NEELAKANDAN
Professor,
Head of the Department,
Department of Paediatrics,
DECLARATION
I, hereby declare that this dissertation entitled “CLINICAL PROFILE OF
INGUINAL HERNIA IN INFANTS” was prepared by me under the guidance
and supervision of Dr. K.NEELAKANDAN Professor and Head of the
Department of Paediatrics, PSG IMS&R, Coimbatore.
This dissertation is submitted to The Tamilnadu Dr. M.G.R Medical
University, Chennai in fulfilment of the university regulations for the award of MD
degree in Paediatrics. This dissertation has not been submitted elsewhere for the
award of any other Degree or Diploma.
CERTIFICATE-II
This is to certify that this dissertation work titled“CLINICAL PROFILE
OF INGUINAL HERNIA IN INFANTS” of the candidate Dr. SHYAM K with
registration Number 201517504 for the award of DOCTOR OF MEDICINE in
the branch of PAEDIATRICS. I personally verified the urkund.com website for
the purpose of plagiarism check. I found that the uploaded thesis file contains from
introduction to conclusion pages and result shows 1%of plagiarism in the
dissertation.
ACKNOWLEDGEMENT
I am extremely grateful and indebted to my guide Dr.K.Neelakandan,
Professor and HOD, Department of Paediatrics, PSG IMS&R, for his invaluable
guidance, concern, supervision and constant encouragement to complete this
dissertation.
I extend my sincere gratitude to Dr. John Matthai, Professor, Former Head
of the Department of Paediatrics, PSG IMS&R, who gave his unflinching support
and invaluable advice in preparing this dissertation.
I sincerely thank Dr. Sarah Paul, Professor, Department of Paediatrics,
PSG IMS&R for her valuable suggestions throughout the study period
I sincerely thank Dr.Pavai, Professor, Department of Paediatric Surgery,
PSG IMS&R for his valuable suggestions throughout the study period
I sincerely thank Dr.S.Ramesh Assistant Professor, Department of
Paediatrics, PSG IMS&R for his valuable suggestions throughout the study period.
I wish to express my gratitude to Dr.K.Jothilakshmi, and
I also thank Dr.Nirmala, Dr.Bharathi, Dr.Vadivel, Dr.Sudhakar, Dr.Muruganantham, Dr.Suchithra and Dr.Kavitha for their support and assistance in helping me to complete this work.
I am very thankful to my colleagues Dr.Nandhini, Dr.Bhuvanesh,
Dr.Raaghul, Dr.Lavanya and Dr.Arya S for their constant support. I also thank my seniors, juniors and all other friends and family members for their support.
I also express my gratitude to the Principal and Dean, faculties of ethical
committee of PSG IMS&R for granting me the permission to conduct the study.
I am extremely grateful and obliged to all the patients without whom this
CONTENTS
1. INTRODUCTION 1
2. AIM 3
3. METHODOLOGY 4
4. REVIEW OF LITERATURE 6
5. RESULTS 49
6. DISCUSSION 73
7. CONCLUSION 78
8. LIMITATION 79
9. REFERENCES
10.ANNEXURES
i. CONSENT FORM
ii. PROFORMA
LIST OF TABLES
TABLE NO.
TITLE
1 Factors Contributing to the Development of an Indirect Inguinal
Hernia
2 Gender distribution
3 Order of birth
4 Inborn / Outborn
5 Gestational age of babies at birth
6 Mode of delivery
7 NICU care
8 TPN given / not
9 Had abdominal distension or not
10 Ventillator / CPAP
11 Other associated anomalies
12 Obstruction / not at presentation
13 Sidedness of hernia
14 Reducibility
15 Incarceration /gangrene
17 Unilateral / bilateral
18 Post operative complications
19 Recurrence / wound infections
20 Teticular atrophy
21 Hydrocele
22 Occurrence of opposite side hernia
23 Maternal risk factors
LIST OF FIGURES
FIGURE NO.
TITLE
1 The most common variants of hernias and hydroceles arising
from failure of complete obliteration of the processusvaginalis.
2 Gender distribution
3 Order of birth
4 Inborn / Outborn
5 Gestational age of babies at birth
6 Mode of delivery
7 NICU care
8 TPN given / not
9 Had abdominal distension or not
10 Ventillator / CPAP
11 Other associated anomalies
12 Obstruction / not at presentation
13 Sidedness of hernia
14 Reducibility
15 Incarceration /gangrene
17 Unilateral / bilateral
18 Post operative complications
19 Recurrence / wound infections
20 Teticular atrophy
21 Hydrocele
22 Occurrence of opposite side hernia
23 Maternal risk factors
1
INTRODUCTION
Inguinoscrotal swellings are one of the commonest surgical problems in
infancy and childhood throughout the world. Among the inguinoscrotal
swellings, inguinal hernia tops the list in frequency. They represent the
conditions frequently requiring surgical repair in the pediatric age group. Hernia
is a Latin term meaning rupture of a portion of a structure. It can be defined as a
“protrusion of a viscus or part of a viscus through a normal or an abnormal
opening in the wall of its containing cavity.” Refinements in neonatal intensive
care have increased the number of surviving premature and very low birth
weight infants and consequently the incidence of neonatal inguinal hernia is
increasing.
The inguinal hernia is the commonest defect the paediatric surgeon
performs surgery on and is usually indirect. It is believed that these hernias
rarely go away, and therefore; virtually all should be repaired. Several issues are
contentious, such as optimal time of herniotomy after diagnosis, obstruction,
feed intolerance, the role of contralateral exploration and for the premature
group; issues are type of anaesthesia and need for post-operative mechanical
ventilation support.1, There is very limited study in India analysing the
incidence of hernia and the risk factors associated with the incidence, like
post-2
operativecomplications and so on. This study is designed to look into the
incidence of hernia in infants with an analysis of the risk factors involved in the
occurrence of inguinal hernia in them like age, sex, sidedness, gestational age at
birth , birth weight, age at the time of occurrence of hernia, use of positive
pressure ventilation, reducibility, time of repair, urgency of repair(done as an
emergency or elective procedure), complications due to the hernia and post
operatively.
STUDY JUSTIFICATION:
Studies suggest that inginal hernia is a common condition requiring
surgical repair in the paediatric age group.The incidence of inguinal hernias is
approximately 3% to 5%in term infants and 13% in infants born at less than 33
weeks of gestational age1. Increased survival of preterm and low birth weight
infants due to better intensive care and has resulted in increased incidence of
hernia in infancy. There is also limited data available from India in assessing the
risk factors involved in the occurrence of inguinal hernia and the pre and post
operative complications associated with it. This study may help us in predicting
3
AIM
To study the clinical profile ie the incidence and risk factors of inguinal
4
METHODOLOGY
This study is based on retrospective collection of data for a period of 3
years from the records library at PSGIMSR and prospective follow up of
patients who are getting admitted at paediatric or paediatric surgery department
in a tertiary care centre(PSGIMSR) for inguinal hernia; for 2 years and
collection of data from them and retrospectively analysing it for the different
risk factors involved in the incidence of inguinal hernia in infants less than 1
year of age and also to look into the complications that occur in them post
operatively.
FLOW CHART:
Proposal to ethics committee and approval from ethics committee
All patients seen as op / getting admitted as a case of inguinal hernia < 1 year of
age in Paediatrics and Paediatric Surgery departments at PSGIMSR
Collection of data and analyzing the risk factors associated with the occurrence
of Inguinal Hernia.
Descriptive and statistical interpretation of risk factors.
5
STUDY DESIGN:
It is a retrospective& prospective observational study.
INCLUSION CRITERIA:
All inguinal hernia cases that are seen as op / getting admitted as a case of
inguinal hernia < 1 year of age in Paediatrics and Paediatric Surgery
departments at PSGIMSR < 1 year of age, for surgical intervention.
EXCLUSION CRITERIA : NIL
STUDY PERIOD: From 01/01/2012 to 31/12/2016 ( 5 Years)
DATA RETRIEVAL:
Data for the retrospective cases will be collected from the records library
at PSGIMSR and for the prospective study; will be collected from the cases that
are seen as op / getting admitted in paediatrics / pediatric surgery department as
6
REVIEW OF LITERATURE
Inguinal hernias are one of the most common conditions seen in pediatric
practice and the most common surgical procedure performed inpediatric
surgical practice. The frequency of this condition in concert with its potential
morbidity of ischemic injury to the intestine, testis, or ovary makes proper
diagnosis and management an important part of daily practice for pediatric
practitioners and pediatric surgeons.
The overwhelming majority of inguinal hernias in infants and children are
congenital indirect hernias (99%) as a consequence of a patent
processusvaginalis (PV); a developmental structure important in
testiculardescent. The incidence of inguinal hernia in children is up to 10 times
higher in boys than in girls. Two other types of inguinal herniaare direct
(acquired) hernia (0.5-1.0%) and femoral hernia (<0.5%).Approximately 50%
of inguinal hernias manifest clinically in the 1st yrof life, most in the 1st 6 mo.
Premature infants have an incidence of inguinal hernia approaching 30%. The
risk of incarceration and pgossiblestrangulation of an inguinal hernia is also
greatest in the 1st yr oflife (30-40%) and mandates prompt identification and
7
HISTORY
Inguinal hernia most probably has been a disease ever since mankind
existed1. In view of its existence in different kinds of animals, and in particular
ofprimates6, one can assume that already prehistoric human beings were
affected with thedisease7. Written proof of this statement became available from
manuscripts and found in Mesopotamian7 and Egyptian cultures.
What appears to be an inguinal hernia has been found on an ancient
Greek statuette, and Egyptian writings describe groin bulges elicited by
coughing (the Papyrus of Ebers, ca 1552 bc ). 8 There is also evidence to
suggest that surgery for hernias had been performed as early as 1200 bc.The
Roman physician Celsus is credited with some of the earliest surgery for
inguinal hernia, circa 50 ad . 8 About that same time Galen described the
anatomy of the processusvaginalis; however, he believed that hernias were the
result of “rupture” of the peritoneum with stretching of overlying muscle and
fascia. 8 This is where the slang term for hernia, “rupture,” may have had its
derivation.
Modern hernia surgery began in the nineteenth century when an accurate
understanding of the anatomy of the inguinal canal became available. 8 Richter,
Camper, and Scarpa, among others, contributed to the field during this period.
Cooper in 1804 described the transversalis fascia and pectineal ligament, or
8
ligament, and in 1817 Cloquet described the processusvaginalis and noted that it
was rarely closed at birth. With a thorough understanding of inguinal anatomy,
modern hernia surgery had only to await the development of aseptic techniques
of surgery.
In 1870 Lister introduced the concept of antisepsis in surgery, and in
1896 Halstead began operating with gloves. 8 In 1904 Von Mickulicz took
aseptic surgery one step further. These developments allowed rapid progress to
be made in hernia surgery. In 1871 Marcy described an operation still in use by
pediatric surgeons to this day: high ligation of an unopened sac through the
external ring and tightening of the internal ring. This technique, however, had
an unacceptably high recurrence rate in adults. 9 In 1887 Bassini reported his
results using a technique involving opening the external oblique, high ligation
of the sac, tightening of the external ring, and reconstruction of the posterior
inguinal floor. 9 Along with Halsted, Bassini is credited with the development of
the modern hernia repair.
Incidence
Inguinal hernia repair remains the most common operation performed by
pediatric surgeons. The reported incidence of inguinal hernia in children ranges
9
Age
Inguinal hernia most commonly presents during the first year of life with
a peak during the first few months. Approximately one third of children are
younger than 6 months of age at the time of operation. 10 The highest incidence
of hernia is found in premature infants, 16% to 25%. 11,12 This correlates fairly
well with the patency rates of the processusvaginalis. At birth 80% are patent
and the rates decrease dramatically by the first 6 months of age. 13 However, all
indirect hernias, regardless of age at presentation, are likely secondary to failure
of the processusvaginalis to close completely during fetal and newborn
development.
Sex
Males are much more likely to have hernias, with the reported
male-to-female ratios between 3:1 and 10:1. 10 Although premature infants have a higher
incidence of hernia, there does not appear to be a significant gender difference
at this age. 14,15,16
Side
Approximately 60% of hernias are right sided. 17 This is true for both
males and females. In males, this is possibly the result of later descent of the
right testicle than the left, but this does not explain the observation in females.
10
suggested that patients with left-sided hernias are more likely to develop a
right-sided hernia than vice versa. 18, 19 More recent data, however, suggest that this
may not be true. 20,21,22
Family history
Approximately 11.5% of patients have a family history. 10 There is an
increased incidence in twins as well, about 10.6% in males and 4.1% in female
twins. 23
Embryology
Indirect inguinal hernias are fundamentally the result of failure of closure
of the processusvaginalisTheprocessusvaginalis is an invagination of the
peritoneum through the internal ring, which can first be identified during the
third month of foetal life. 24 Some have suggested that formation of the
processusvaginalis is a result of intra-abdominal pressure, 25 whereas others
believe this to be an active process.26,27 The intra-abdominal testis passes
through the processus during the seventh to ninth months of gestation. During
this time the processus elongates. Following this, the portion of the
processusvaginalis lying above the testicle obliterates, closing the internal
inguinal ring, while the distal portion persists as the tunica vaginalis. Failure of
this to occur results in patency of the processusvaginalis and potentially an
11
hydrocele (peritoneal fluid only)(fig 1). In females the canal of Nuck
corresponds to the processusvaginalis and communicates with the labia majora,
the female homologue of the scrotum. The canal of Nuck normally closes
[image:24.595.78.521.230.435.2]around the seventh month of gestation, earlier than in males.
Fig :- 1.
The most common variants of hernias and hydroceles arising from failure
of complete obliteration of the processusvaginalis.
The exact timing of closure is uncertain. Studies have suggested that up
to 80% to 100% of infants are born with a patent processusvaginalis and that
closure, if it occurs, is most likely to happen within the first 6 months of
life. 13,28 After 6 months of age, patency rates fall more gradually and plateau
generally around age 3 to 5. It also appears that the left side closes earlier than
12
distal) is unknown. After closure of the processus, it persists as a cord, which
subsequently disappears and becomes incorporated into the external spermatic
fascia. The high rate of patency associated with undescended testis suggests that
closure most commonly occurs only after descent of the testicle or that these
processes are linked.
The biologic mechanisms that signal and induce descent of the testicle
through the inguinal canal and obliterate the processus are for the most part
unknown. Androgens appear to play a role because patency of the processus is
common in androgen insensitivity syndrome. However, the processus itself has
no androgen receptors. Work from Hutson and colleagues has implicated the
genitofemoral nerve (GFN) and calcitonin gene–related protein (CGRP) in both
testicular descent and obliteration of the processusvaginalis. 24 They have
suggested that reduced CGRP release from the GFN prenatally may result in
undescended testis, whereas reduced CGRP postnatally may lead to hernias and
hydroceles. Although it is clear that a patent processusvaginalis is a prerequisite
for an inguinal hernia, it is not sufficient and other factors are involved. Table 1
13
Table :- 1 Factors Contributing to the Development of an Indirect Inguinal Hernia
Urogenital
Undescended testis
Exstrophy of bladder
Increased peritoneal fluid
Ascites
Ventriculoperitoneal shunt
Peritoneal dialysis
Increased intra-abdominal pressure
Repair of exomphalos or gastroschisis
Severe ascites (e.g., chylous)
Meconium peritonitis
Chronic respiratory disease
Cystic fibrosis
Connective tissue disorders
Ehlers-Danlos syndrome
Hunter-Hurler syndrome
Marfan syndrome
14
Clinical Features
Inguinal hernias are generally found by parents at bath time or during
well-child examinations by their pediatricians. There is typically a history of
intermittent bulge in the groin, labia, or scrotum. It is most often apparent when
there is increased intra-abdominal pressure such as during episodes of crying or
straining. When taking the history of present illness, it is important to sort out
inguinal hernias from communicating hydroceles, undescended testis, and
inguinal adenopathy. Hernias may present at birth or not until days, weeks,
months or even years later, but the defect to a variable extent has been there
since birth. This becomes important to remember when asymptomatic hernias
are found, in terms of the timing of surgery (i.e., not an emergency) and the
activities children should be allowed to participate in while awaiting repair (i.e.,
no restrictions if asymptomatic).
Hernias are usually asymptomatic. Because hernias often appear during
episodes of infant distress, parents often feel the hernia is the cause of these
symptoms. Unfortunately, many of these perceived symptoms persist after the
repair.
Incarcerated hernias result from entrapment of bowel or other viscera
within the hernia sac. Debate has continued as to whether “entrapment” occurs
at the internal or external ring. The answer is that it can occur at both, but
15
and irritability. Subsequently, signs of bowel obstruction result, such as
distension, vomiting, and obstipation. If hernia is not reduced, blood supply to
the incarcerated organ might be compromised to the point of infarction, called
“a strangulated inguinal hernia.” The patient may present with peritonitis at this
time. This process can occur even within 2 hours. Incarceration occurs most
commonly in the first 6 months of life and after age 5 is relatively rare.
Prematurity
It is well established that premature infants have a higher incidence of
inguinal hernias and are likely to have a bilateral presentation. Moreover, the
more premature the infant, the higher is the incidence of inguinal hernia. In a
review of 82 infants weighing less than 2000 g, Walsh found a 13% incidence
of inguinal hernia. Of 28 infants less than 1500 g, 7 (25%) had an inguinal
hernia compared with 4 (7%) infants greater than 1500 g. 12 Rescorla and
Grosfeld reviewed 100 infants younger than 2 months of age who required
inguinal hernia repair; 30% of these infants were premature and 44% had
bilateral hernias. 73 Of 1391 very-low-birth-weight infants (weight < 1500 g)
reported by Rajput and colleagues, 11 222 (16%) developed an inguinal hernia
between 28 days and 20 months of corrected age. Peevy, Speed, and Hoff
studied 397 newborn infants and found a 9% incidence of inguinal hernias in
infants weighing between 1000 g and 1500 g and 30% in those weighing 500 g
16
Harper and colleagues 113 reported that 11 (30%) developed an inguinal hernia.
Two of these 11 were incarcerated (18%). Although the incidence of
incarceration is increased in infants and may be as high as 28%, it appears to be
lower in premature infants, with reported incidences of 13% to 18%, compared
with mature infants.
Ventriculoperitoneal shunts/peritoneal dialysis:
A significant factor in the development of an inguinal hernia is excess
fluid in the peritoneal cavity, and in patients with a patent processusvaginalis,
procedures that introduce fluid into the peritoneal cavity may induce a hernia or
hydrocele. Whether hernia is due to the physical presence of the fluid or is
secondary to increased intra-abdominal pressure is unknown. Abnormal
neuromuscular function may also be a factor. Moazam and
colleagues 114 reviewed 134 patients who had ventriculoperitoneal shunt
procedures; inguinal hernias developed in 19.5% of patients with
meningomyelocele and 47% of those with intraventricular hemorrhage. All of
the latter were premature, however. Grosfeld and Cooney 85 found a 14%
incidence of inguinal hernia after insertion of ventriculoperitoneal shunts; 20%
developed an incarceration and the hernia recurred in 16%. On the basis of this
study the authors recommended that (1) after ventriculoperitoneal shunts,
infants should be closely watched for the development of a clinical inguinal
17
because of the increased risk of incarceration, and (3) in these patients the
contralateral side should be explored in the case of a clinical unilateral hernia.
Clarnette and colleagues 115 evaluated 430 patients who underwent
ventriculoperitoneal shunt placement. In their series, 15% developed an inguinal
hernia and a hydrocele developed in another 6% of boys. Hernias were bilateral
in 47% of boys and 27% of girls. The incidence of subsequent inguinal hernia
development closely paralleled the age at which the shunt was performed. In the
last 8 weeks of gestation or in the first few months of life the incidence was
30%, then falling sharply to 10% at age 1 year. They argue that raised
intra-abdominal pressure is the likely etiology of these hernias. They also conclude
that patency of the processusvaginalis is 30% in the first few months of life and
supports the possibility that a patent processusvaginalis can close in the first
year of life.
The concern in this younger population is that they are preverbal and their
caretakers may not recognize the signs and symptoms of an incarceration in a
timely manner. We instruct our families of preverbal infants with hernias
waiting for elective surgery that the differential diagnosis of a crying baby
includes (1) needs to be fed, (2) needs a diaper change, (3) needs a nap, and (4)
“needs an operation” (may have an incarcerated hernia). We also instruct the
18
Examination:
To examine for an inguinal hernia, the patient is placed supine and
undressed on an examining table in a warm room. The examiner first observes
for an inguinal mass or asymmetry of the groins. The testis should be “trapped
in the scrotum” with a finger across the top of the scrotum to account for both
testes and to sort out true inguinal bulges from retractile testis. If no mass can be
identified, the older child should stand and perform a Valsalvamaneuver. An
infant may be allowed to strain or cry to provoke an inguinal bulge to appear. If
a mass is still not present, the spermatic cord can be palpated to determine
thickening (the silk glove sign). 29 This is performed by laying a single finger
over the spermatic cord at the level of the pubic tubercle. The finger is lightly
rubbed over the cord from side to side over the pubic tubercle. A positive silk
glove sign indicates that the cord structures within the inguinal canal are
thickened compared with the normal side. The examination imparts to the
examiner the sensation of rubbing two pieces of silk together or the sensation of
feeling a plastic bag with few drops of water in it (“plastic baggy sign”), but
these signs are not accurate completely and are subjective.
If the hernia is not demonstrable on physical examination, some surgeons
will still operate if the hernia has been seen previously by a physician or if the
parents give a history. 30 However, with parental education, follow-up
19
avoided. Advantage can be taken of photographic documentation by parents.
Kawaguchi and Shaul (2009) 31 found that they could accurately diagnose an
inguinal hernia in equivocal cases using parents' images.
Radiologic Investigations
In most cases the diagnosis of an inguinal hernia can be made by history
and physical examination alone. However, in a small subset of patients
radiologic testing may be of value. Previously, the technique most commonly
used had been contrast herniography, but this has now been replaced by
inguinal ultrasonography (US).
Herniography is performed by injecting water-soluble contrast material
into the peritoneal cavity via an infraumbilical fluoroscopic-guided
injection. 32 Gravity will allow the contrast material to pool into the hernia sac,
which is identified by plain radiographs taken at 5, 10, and 45 minutes apart.
Hydroceles can be identified by this technique, and femoral hernias can be
differentiated from inguinal hernias. This test is also useful for detecting the
contralateral hernias or in postoperative patients with recurrent ipsilateral groin
symptoms. It has no value, however, for incarcerated hernias because the neck
of the sac is occluded in those cases. Complication rates for this technique are
rare and include intestinal perforation, intramural intestinal hematoma, and
allergic reactions to the contrast media. 32,33 Despite this, herniography had not
20
Ultrasound has gained some popularity as an adjunct to the physical
examination. It has the advantage of being rapid, non-invasive, and
complication free. Chen and colleagues 34performed usg on 244 boys presenting
with unilateral or bilateral hernias.Usgwere performed on both groins. They
noted an accuracy of 97% when using 4 mm as the upper limit of the normal
diameter of the inguinal canal. In a series of 642 children, Erez and
colleagues 28 noted that a preoperative measurement of the inguinal canal of 3.6
± 0.8 mm was associated with normal findings at surgery, whereas 4.9 mm ±
1.1 mm was associated with a patent processusvaginalis and 7.2 ± 2 mm or
greater was associated with a true hernia. 35 Therefore using appropriate
measurements, Ultrasonogram is a reliable tool for diagnosing hernias when a
good history is present, but the examination is equivocal and is potentially
useful for preoperative evaluation of the contralateral groin in patients
presenting with unilateral hernias.
Management
An inguinal hernia will not resolve spontaneously, so surgical closure is
always indicated. Because of the high risk of incarceration, particularly in
young infants, repair should be performed expeditiously. Some reports suggest
90% of complications can be avoided if repair is undertaken within 1 month of
diagnosis. 36,37 More recently Langer and colleagues found that repair
21
with a 30-day wait. Furthermore, most patients can be done safely in an
ambulatory setting. Exceptions include premature infants and older children
with significant risk factors such as cardiac or respiratory problems. Choice of
anesthetic type varies with the patient. Although most patients are treated under
general anesthesia with endotracheal intubation or laryngeal mask, several other
options exist and the choice of technique depends on several factors including
age and significant comorbidities.
Anesthesia
Anesthesia techniques can be classified as general, regional, or local
techniques. Healthy full-term infants and older patients are treated under
general endotracheal anesthesia, andhas been found to be safe. However, others,
particularly premature infants (>36 weeks gestational age and gestational age
plus chronologic age younger than 60 weeks) require a more varied approach.
Regional techniques (spinal, epidural, or caudal anesthesia) are often chosen in
these situations. Although each has its proponents, none has been shown to be
definitively superior. A recent review of the Cochrane database found several
small trials comparing regional versus general anesthesia. No statistical
difference was demonstrable in the proportion of premature infants having
postoperative apnea/bradycardia, respiratory rate, or postoperative oxygen
desaturations. However, the total enrolled number of patients in the trials was
22
Postoperative pain control has also been a matter of some debate. Caudal
blocks are routinely performed in some centers, whereas other centers use
instilled local anesthetic. A recent randomized prospective trial comparing
instillation of 0.25% bupivacaine without epinephrine (2.5 mg/kg) versus caudal
block found no difference in the level of postoperative pain. 39 Additionally,
instillation of local anesthetic (so-called splash technique ) is as effective as
injection into the wound.
Recently concerns have been raised about the effect of anesthesia in the
developing brain. Most research has been in animal models and has clearly
shown the anesthetics can induce brain cell apoptosis. However, conclusions
about effects on humans have been mixed. In 2009 Wilder and
colleagues 40 looked at a population of children and identified that learning
disabilities were more common in children younger than age 4 who had
undergone general anesthesia. Similar results were found by DiMaggio and
colleagues 41 in children younger than 3 years of age undergoing inguinal
hernia.
Age for overnight stay
Most full-term infants and older children undergo same-day hernia
surgery. The age at which an ex-premature infant can safely have same-day
hernia surgery is debatable. One study showed preterm infants younger than 41
23
greater risk of postoperative apnea. 42 Another large study, using sophisticated
monitoring techniques for monitoring postoperative breathing disturbances,
found that infants younger than 44 postconceptualage were at increased risk of
clinically significant episodes of postoperative apnea. 43 In 1995 a combined
analysis from eight prospective studies was performed and concluded that the
incidence of postoperative apnea was not less than 1%, with 95% statistical
confidence, until 56 weeks for a 32-week premature infant and 54 weeks for a
34-week premature infant. 44
Timing of surgery
Most surgeons currently recommend repair of the hernia soon after
diagnosis. 45 This practice can result in a significant reduction of complications
from the hernia and is practicable because of the safety of modern anesthesia.
Regarding premature infants, most surgeons recommend repair before discharge
after the child has attained a weight of about 2 kg. 45 This is in contradistinction
to surgical practice up to 1996, in which only 33% of surgeons polled would
operate on a premature infant. 37 Langer and colleagues reviewed a series of
infants and children undergoing inguinal hernia repair. In infants younger than 1
year of age, the risk of incarceration doubled with surgical wait times of more
24
Sex
Historically, many surgeons have performed bilateral exploration on
females, primarily on the premise that routine bilateral exploration poses little
risk to the patients because of the relative rarity of finding reproductive
structures in the sac. In a survey in 1981, Rowe and Marchilidon reported that
90% of surgeons routinely explored the contralateral groin in girls younger than
1 year of age. 30 Weiner and colleagues 37surveyed surgeons in 1996 and found
that 84% performed routine exploration in females younger than age 4. 37 It
appears that this trend is on the decline because Levitt and colleagues 45 2002
found that only 39% of surgeons performed bilateral exploration in females
younger than age 5. Despite the rare findings of reproductive structures in the
hernia sac, damage to the inguinal floor and to the ilioinguinal and iliofemoral
nerves still exists and is generally ignored in arguments for contralateral
exploration. Because little follow-up data exist in the literature, it is difficult to
quantify these risks. It is evident that only about 20% of females with a
unilateral hernia will develop a contralateral hernia. Thus a large number of
explorations would be necessary to prevent a few hernias from developing. Puri
and colleagues recently reviewed 300 females undergoing unilateral hernia
repair. 60 In a follow-up ranging from 1 to 4 years, only 8% developed a
contralateral hernia and this was not influenced by age at operation of side of
25
Age
On the basis of the findings of Rothenberg and Barnet 28 that 100% of
infants younger than 1 year of age will have bilateral patent processusvaginalis,
many surgeons routinely perform contralateral exploration in infants. In the
most recent survey, 51% of surgeons routinely perform contralateral exploration
in premature infants and 40% perform contralateral exploration in boys younger
than 2 years of age. 45 This is considerably less than reported from the 1981
survey in which 80% routinely explored the contralateral side in boys. 30 In a
large series of 1052 patients followed up to 11 years, contralateral hernias
appeared in 13.1% of boys younger than 1 year of age and 13.7% younger than
2 years of age. In females contralateral hernias appeared in 9.6% of patients
younger than 1 year of age and 13.9% of patients younger than 5 years of age.
Another recent series looked at 181 infants younger than 1 year of age
undergoing unilateral repair. Contralateral hernias developed in 7.7% in
follow-up ranging from 5 to 10 years. On the basis of these results, it is not completely
clear that younger children have a significantly higher chance of developing a
contralateral inguinal hernia.
Side and size
It is speculated that right-sided hernias are more common than left
because the right processusvaginalis closes later than the left side. Therefore
26
likely to have bilateral hernias than those patients initially presenting with a
right-sided hernia. As a result, many surgeons recommended routine exploration
in patients presenting with left-sided hernias. McGregor and
colleagues 19 reviewed a 20-year experience and found 41% of patients having
an initial left inguinal hernia presented with a right hernia, whereas only 14% of
patients developed a left inguinal hernia after the right side was operated
upon. 19 Others have reported much lower rates of contralateral occurrence after
left-sided repair. Kemmotsu and colleagues 47 reviewed 1052 patients who had
undergone unilateral repair and found that the side of initial repair did not
influence contralateral recurrence. 47 Miltenburg and colleagues 48 found that the
risk of contralateral hernia repair was 11% (50%) higher than if the initial
hernia had been on the right. Overall, it appears that the side of the initial hernia
has no bearing on the risk of developing a contralateral hernia.
Laparoscopy
In an effort to limit the number of negative contralateral explorations,
alternative techniques have been used to determine the patency of the
contralateral processus. These have included diagnostic pneumoperitoneum (the
Goldstein test) in which the abdomen is insufflated via the hernia sac and the
contralateral groin is palpated for crepitance, indicating the patent
processusvaginalis. A recent study of 62 patients found 11% had a positive
27
a contralateral patent processusvaginalis. Of the 55 patients with a negative
Goldstein test, only 3 (5%) have subsequently developed a clinical hernia. In
our opinion this technique is both safe and reliable. However, others have found
that this test is unreliable and often misses patent processes. Bakes dilators have
been used to probe the contralateral groin, but this technique is often difficult
and unreliable. Herniography has been discussed previously and is rarely used
today. Ultrasound has also been discussed previously and found to be fairly
sensitive for the presence of patent processes vaginalis when appropriate-size
criterion are used.
In the early 1990s laparoscopy was used as a means of assessing the
contralateral inguinal canal. Laparoscopy has advantage of being technically
easy and allowing direct visualization of contralateral internal ring.
Nonreducible Hernia
Most inguinal hernias are readily reducible into the abdominal cavity.
Those which are difficult to reduce are “incarcerated.” A strangulated hernia
occurs when there is vascular compromise of entrapped viscera. This is due to
constriction by a tight internal or external ring. Most children will progress
rapidly to strangulation if the hernia is not reduced. This process can take as
little as 2 hours. Initially, constriction by the ring leads to venous and lymphatic
obstruction and subsequent swelling of the viscera. Arterial compromise then
28
the bowel or other viscera. Incarceration and strangulation can also damage the
testicle by compromising the blood supply to the testis. Patients with
incarcerated hernias are more likely to have testicular atrophy after hernia
repair.
Various series have reported the incidence of incarceration to be in the
range of 12% to 17% and seem to be similar in boys and girls. 50,51 Incarceration
is most likely to occur in the first year of life and then falls off thereafter .
Interestingly, the data in premature infants suggest that they are less likely than
full-term infants to have an incarceration, even though the incidence of hernia is
higher in this subgroup. Full-term infants younger than age 2 to 3 months are
found to have a rate of incarceration of 28% to 31% 50,52 and 24% in infants
younger than 6 weeks of age. 53 Interestingly, premature infants were found to
have lower incidence of incarceration compared with full-term infants (13% to
18%). This may be a result of larger rings and less chance of viscera becoming
entrapped and many of these infants are in neonatal intensive care units under
constant surveillance; incarcerated hernias may be prevented by early reduction
or may simply be underreported as caretakers in the nursery reduce them.
Diagnosis
If a loop of bowel becomes entrapped in a hernia, the patient often
becomes extremely irritable and develops intense pain followed by signs of
29
tense, nonfluctuant mass will be found in the groin, possibly extending into the
scrotum. As the viscera strangulate, the mass becomes more and more tender.
Occasionally the mass will transilluminate and be confused with a hydrocele.
Under no circumstances should the mass be aspirated in an attempt to diagnose
and treat a supposed hydrocele.
Late signs of a patient with a strangulated hernia are those of shock,
blood in the stool, and peritonitis. The testes are usually palpable, but
occasionally they can be large and firm and difficult to distinguish from a
testicular torsion. Abdominal radiographs reveal a partial or complete bowel
obstruction. Bowel gas may also be seen in the scrotum. In uncertain cases
ultrasound can be useful to distinguish bowel from hydrocele fluid or a
testicular torsion.
Nonoperative management
In patients without obvious signs of shock or peritonitis, nonoperative
management is first attempted. Lay the child down and try to calm him or her
without feeding with the feet elevated if possible. Standing on the ipsilateral
side of the child, or at the feet of an infant, place the left index and middle
finger on the ipsilateral anterior superior iliac crest and sweep the fingers down
along the inguinal canal toward the ipsilateral scrotum, keeping tension on the
testicle in the male child, inguinal mass, or scrotal skin with the left hand.
30
of the hernia sac with the axis of the inguinal canal. Next, at the level of the
ipsilateral internal ring, apply pressure with the right index finger and thumb on
either side of the hernia neck. This, along with traction on the scrotum, helps to
align and to keep open the external and internal rings. It also prevents the hernia
sac from overlapping or being caught on these potential barriers during
reduction. Finally, with the left hand at the apex of the mass, and with constant
pressure at the level of the internal ring from the right index finger and thumb,
walk your left fingers slowly up the groin toward the internal ring, keeping
constant pressure on the bottom of the hernia contents. This may take several
minutes. If successful, the hernia contents will gradually disappear into the
internal ring. To be certain it is reduced; compare it with the contralateral side.
Use a mirror image technique for the right side. If this technique is unsuccessful
or the child has a difficult time tolerating it, sedation may be used. We do not
recommend reduction of the bowel under general anesthesia because injury to
the bowel may occur or gangrenous bowel may be placed back into the
peritoneal cavity and be unrecognized. Often sedation alone may be sufficient to
promote spontaneous reduction. Reduction of gangrenous bowel has been
reported, so we recommend watching the child in the hospital for 24 hours after
a difficult reduction. Delay of definitive repair of the hernia for at least 24 to 48
31
Operative management
In those situations where nonoperative management fails or the patient
has signs of shock or peritonitis, surgery is indicated. Intravenous fluids are
initiated, and urine output is monitored. Broad-spectrum antibiotics are given,
and if signs of obstruction are present a nasogastric tube is placed. When the
patient is adequately resuscitated, the patient is taken to the operating room. If
the hernia reduces after the general anesthetic is induced, but before surgery, the
operation should still proceed. Several operative approaches have been
advocated for incarcerated hernias including inguinal approaches and
preperitoneal approaches. The use of laparoscopy can also be valuable in the
management of incarcerated hernias.
Postoperative Complications
Scrotal swelling
After hernia repair and particularly communicating hydrocele repair, fluid may
accumulate in the distal sac, forming a noncommunicating hydrocele. Usually
this resolves spontaneously: rarely, aspiration or secondary scrotal hydrocele
repair may be necessary. Scrotal hematoma may follow excision of the distal
32
Iatrogenic undescended testicle
Iatrogenic undescended testis after hernia repair is an uncommon but
possibly underreported complication. Kiesewetter 83 reported 2 patients with
this abnormality in a series of 248 patients, and Hecker and
Ring-Mrozik 84 reported 5 patients in a series of 1957 patients, an incidence of 0.2%.
Except in the case of congenital undescended testicle, this abnormality results
from failure to replace the testis back in the scrotum at the conclusion of the
procedure or the testis subsequently trapped in a retracted location. Secondary
orchidopexy is required to correct this problem.
Recurrence
It is difficult to determine the precise incidence of recurrence after indirect
inguinal hernia repair because factors such as sex and incarceration are not
always clearly defined in reported series. In general, the reported recurrence rate
for uncomplicated hernia repair is 0% to 0.8%; this rises to about 15% for
preemies and about 20% after operation for incarcerated hernias. In many
series, patients were not contacted for long-term follow-up; therefore the true
incidence is not known and is probably higher than stated. Reports on patients
with incarcerated inguinal hernias do not state whether the initial management
33
Many factors associated with the development of primary hernias may
also predispose to recurrence. For instance, Grosfeld and Cooney, in a series of
25 patients with ventriculoperitoneal shunts, identified three recurrent inguinal
hernias (12%). 85Incarceration is also an important risk factor for recurrence.
Steinau and colleagues 86found that in 24% of 29 patients (25 boys, 4 girls) with
a recurrent inguinal hernia, the primary hernia had been incarcerated compared
with 7.6% incidence of recurrence in 2754 patients without incarceration. Other
risk factors in their study were postoperative complications (9.4% recurrence
rate) and concomitant diseases and abnormalities. 87Interestingly, Harvey,
Johnstone, and Fossard found that the level of experience of the surgeon was
not a factor, although technical inadequacies contributed to recurrence. 88Most
recurrent inguinal hernias are indirect and probably result from tearing of a
friable sac, failure to dissect the complete sac, a slipped ligature at the neck of
the sac, or failure to ligate the sac high at the internal ring. Another risk factor
for recurrence is prematurity. Several series of inguinal hernia repairs in
premature infants have reported increased recurrence rate ranging from 2% to
about 15%. Large hernias and inadvertent opening of the hernia sac during
surgery have also been noted to increase recurrence. 89Interestingly, in 2006,
Ein and colleagues 90 did not note significantly increased recurrence rates in
34
Less frequently, a “recurrence” presents as a direct inguinal hernia or a
femoral hernia missed and not properly diagnosed and repaired at the first
operation. Of the 34 recurrences reported by Steinau and colleagues, 87 4 were
direct and one was femoral. In the Fonkalsrud, Delorimier, 91 and Clatworthy
series of 14 direct inguinal hernias, 4 (31%) followed repair of an indirect
hernia. A direct hernia following repair of an indirect hernia is either a
concomitant hernia not recognized at the initial operation or new pathology
caused by damage to the posterior wall of the inguinal canal during the initial
dissection. A recurrent hernia in the femoral area is also likely to have been a
missed hernia rather than a true recurrence.
Several large series exist of laparoscopic inguinal hernia repair in
children. Schier reported 403 inguinal hernia repairs on 279 patients and had a
recurrence rate of 2.3%. 92The technique of laparoscopic inguinal hernia repair
varies from surgeon to surgeon and is still in evolution. Moreover, there is
likely to be a learning curve with the laparoscopic techniques, such that
recurrences are more likely to be higher earlier in one's experience.
Injury to the vas deferens
Although vas transection may be obvious interoperatively, accidental
operative crush injury to the vas deferens is unlikely to be recognized until
adulthood and possibly then only if the injury is bilateral. Sparkman 93 reported
35
“segments of the vas deferens” in 5 of 313 hernia sacs from children who had
undergone hernia repair. Details of the five cases were not published, however,
and no histologic or clinical information is available. Walker and Mills found
small glandular inclusions in approximately 6% of hernia sacs from prepubertal
boys, which they believe to be müllerian duct remnants and not segments of the
vas deferens.94 They emphasized that these structures were of no clinical
significance. It is likely that similar structures accounted for some of the
findings reported by Sparkman. Perhaps a better estimate is provided by
Steigman, Sotel-Avila, and Weber, 95 who reviewed the histology of hernias
sacs submitted from 7314 males undergoing hernia repair over a 14.5-year
period. Seventeen cases contained vas deferens (0.23%); 22 had epididymis
(0.3%), and 30 had embryonal rests (0.4%). Three sacs contained coexisting vas
deferens and epididymis. Either vas or epididymis was found in 0.53% of sacs.
Also, Patrick and colleagues 96 found a rather low incidence of 0.13% of vas
injury in an analysis of 1494 sacs. They also argued that the incidence is so low
that routine histologic evaluation of the sac is not warranted.
Shandling and Janick demonstrated the vulnerability of the vas during
hernia repair. 97In their experiments, the vas deferens of rats were exposed and
grasped with fingers, nontoothed forceps, bulldog vascular clamps, or mosquito
hemostats. Serial studies of the vas were done over 6 months, and damage to the
36
colleagues 98 demonstrated that stretching of the spermatic cord might also
damage the vas and testicle. They applied horizontal stretch force of varying
amounts to the spermatic cord of rats. Significant thinning of the smooth
muscle layer of the vas was noted with all degrees of stretching, as was
testicular atrophy.
The relationship between male fertility and previous inguinal hernia
repair is not well defined. Hommonnai and colleagues 99 reported findings on
131 men referred to an infertility clinic who had undergone inguinal hernia
repair between the ages of 2 and 35 years. Although 14% of these men had
testicular atrophy or abnormal sperm findings that could be related to the hernia
operation, clinical details such as the incidence of incarceration and experience
of the surgeon were not reported.
Operative injury to the vas deferens may result in obstruction of the vas with
diversion of spermatozoa to the testicular lymphatics, and this breach of the
blood-testis barrier produces an antigenic challenge with formation of spermatic
autoagglutinating antibodies. In a review of 76 infertile men with spermatic
autoagglutinating antibodies, 12 (16%) had unilateral inguinal hernia repair
during childhood. 101 In 10 of these men the site of the inguinal hernia repair
was explored, and in 5 patients an obstruction of the vas deferens was
identified. The authors concluded that accidental transection or ligation of the
37
reason for infertility in men. Parkhouse and Hendry reported similar
findings. 102 Thus although these reports do not indicate the incidence of
infertility of men after inguinal hernia repair, they do suggest that an association
exists.
Testicular atrophy
The testicular vessels are vulnerable to operative injury, particularly in small
infants, but reports of testicular atrophy after routine hernia repair are rare.
Fischer and Mumenthaler 104 and Fahlstrom, Holmberg, and Johansson 103 each
reported an incidence of testicular atrophy of 1%. In these studies the operative
technique varied, and the number of incarcerated hernias was not reported;
therefore this may not indicate the true incidence of testicular atrophy when
hernia repair is performed by an experienced surgeon using a simple high
ligation to obliterate the open sac.
With incarcerated hernia, the blood supply to the testis may be impaired by
compression of the testicular vessels by the incarcerated viscus. The incidence
of testicular compromise in association with incarcerated inguinal hernia ranges
from 2.6% to 5%. The finding of a cyanotic testicle at emergency operation is
common, reportedly 11% to 29%. The actual incidence of testicular atrophy as
indicated by histologic examination or diminished size at follow-up is much
lower, varying from 0% to 19%. Unfortunately, reported series of patients
38
length of follow-up and the criteria for evaluation of the testis vary
considerably. Puri, Guiney, and O'Donnell, 105 in an analysis of 87 boys with
incarcerated hernia treated by nonoperative reduction, found unilateral testicular
atrophy in 2 patients or 2.3%. From the available data, we conclude that
vascular compromise is common but the risk of actual infarction is low.
Therefore unless the testis is frankly necrotic, it should not be removed.
The herniated ovary and fallopian tube are also susceptible to vascular
compromise, either as a result of incarceration or, perhaps more likely, torsion
of the ovary within the hernia sac. The reported incidence of strangulation of
irreducible ovaries is as high as 32%. Boley and colleagues 106 reported a 27%
strangulation rate in 15 females presenting with incarceration. In addition,
several case reports have demonstrated injury to the fallopian tubes from
bilateral hernia repair, resulting in female infertility.
Intestinal injury
With incarcerated hernias, the incidence of intestinal infarction is remarkably
low. Between 1960 and 1965, the incidence of intestinal resection in the report
by Rowe and Clatworthy 70 of 351 patients with incarcerated hernias was 1.4%.
A review of three series published since 1978 shows no resections in 221
39
Loss of abdominal domain
A complication of hernia surgery that is not rotuinley discussed is
postoperative respiratory failure as a result of lost abdominal domain. The right
of domain is the concept that each organ occupies a space within the body that it
has a right to fill. In giant inguinal hernias, particularly bilateral giant hernias,
the majority of the intestine can lie within the hernia sac and outside of the
peritoneal cavity. If this occurs for some time, the intestine can lose its right of
abdominal domain. During repair, the intestine is returned to the abdominal
cavity, resulting in increased intra-abdominal pressure and respiratory failure.
Bascombe, Caty, and Glick 107 reported an ex-premature infant with large
bilateral inguinal hernias who required 41 days of mechanical ventilation after
repair.
Respiratory failure after inguinal hernia repair is common, especially in
premature infants. Gollin and colleagues 108,109 found 34% of premature infants
required mechanical ventilation after herniorrhaphy. It is possible that increased
intra-abdominal pressure as a result of loss of domain may be an unrecognized
contributor to this problem. As a result of their experience, Glick and
colleagues 108 have recommended staged repair of large bilateral hernias in the
elective setting, especially because the risk of a second anesthesia is so low
using modern technique. In an emergency setting (e.g., repair of giant
40
considered to alleviate abdominal compartment pressures and allow the
intestine to be slowly returned to the abdomen.
Chronic pain
Chronic pain after adult hernia repair is found in about 10% of patients.
This incidence is unknown in patients undergoing hernia repair in childhood. In
2007 Aasvang and Kehlet110 surveyed adults who had undergone hernia repair
younger than the age of 5. Although 13.5% reported some pain from the
operated groin (usually associated with physical activity), only 2% reported this
pain to be severe.
This issue may be of relevance in the older teenager in whom mesh is
used. In fact, there seems to be no general consensus as to the age when mesh
repair may be appropriate and the older teenager may receive a different
operation if corrected by an adult surgeon versus a pediatric surgeon.
Inguinodynia can be effectively improved in the great majority of patents
by combined neurectomy and mesh removal. As noted previously, Ein 90 found
in his personal series that teenagers had a significantly higher recurrence rate
than other age groups. Interestingly, there are no published studies comparing
mesh versus standard repair in adolescents. Clearly, this is an issue that is best
41
Ventriculoperitoneal shunts/peritoneal dialysis
A significant factor in the development of an inguinal hernia is excess
fluid in the peritoneal cavity, and in patients with a patent processusvaginalis,
procedures that introduce fluid into the peritoneal cavity may induce a hernia or
hydrocele. Whether hernia is due to the physical presence of the fluid or is
secondary to increased intra-abdominal pressure is unknown. Abnormal
neuromuscular function may also be a factor. Moazam and
colleagues 114 reviewed 134 patients who had ventriculoperitoneal shunt
procedures; inguinal hernias developed in 19.5% of patients with
meningomyelocele and 47% of those with intraventricularhemorrhage. All of
the latter were premature, however. Grosfeld and Cooney 85 found a 14%
incidence of inguinal hernia after insertion of ventriculoperitoneal shunts; 20%
developed an incarceration and the hernia recurred in 16%. On the basis of this
study the authors recommended that (1) after ventriculoperitoneal shunts,
infants should be closely watched for the development of a clinical inguinal
hernia, (2) operation should be done promptly after diagnosis of a hernia
because of the increased risk of incarceration, and (3) in these patients the
contralateral side should be explored in the case of a clinical unilateral hernia.
Clarnette and colleagues 115 evaluated 430 patients who underwent
ventriculoperitoneal shunt placement. In their series, 15% developed an inguinal
42
in 47% of boys and 27% of girls. The incidence of subsequent inguinal hernia
development paralleled the age at which the shunt was performed. In the last 8
weeks of gestation or in the first few months of life the incidence was 30%, then
falling sharply to 10% at age 1 year. They argue that raised intra-abdominal
pressure is theetiology of these hernias. They also conclude that patency of the
processusvaginalis is 30% in the first few months of life and supports the
possibility that a patent processusvaginalis can close in the first year of life.
There is a well-established risk of inguinal hernia developing in patients
on long-term ambulatory peritoneal dialysis, ranging from 7% to 15%. In such
cases the patent processusvaginalis is likely to develop into a frank hernia.
Intraoperative herniography is recommended when the peritoneal dialysis
catheter is inserted. Water-soluble contrast is infused through the catheter, and
the patient is placed in a head-up position for 15 minutes. If a patent
processusvaginalis is identified, repair is in order. Alternatively, direct
laparoscopic visualization of the internal ring can be performed at the time of
catheter placement, particularly if the catheter placement itself is performed
laparoscopically. Repair can then be performed open or laparoscopically.
Sliding hernia
The fallopian tube or mesosalpinx is frequently found in the wall of the
hernia sac in girls and is at risk of injury. The operative management has