Preamble/Introduction

Inguinal hernia and hydrocele share a common etiology. The surgical correction is also similar. The advent of minimal access techniques has challenged conventional management for the treatment of hernia in particular. Inguinal hernia (indirect) is a protrusion of intra-abdominal contents into the inguinoscrotal = labial canal formed by the failure of obliteration of the processus vaginalis.¹ Hydrocele is the accumulation of fluid within the same spatial remnant.² The purpose of this guideline on inguinal hernia and hydrocele is to inform practitioners and allied health professionals on the nature, clinical features, surgical options, and outcome of these two related conditions in children.

Disclaimer

Clinical practice guidelines are intended to indicate the best available approach to medical conditions as established by systematic review of available data and expert opinion. The approach suggested may not necessarily be the only acceptable approach given the complexity of the health care environment. These guidelines are intended to be flexible, as the physician must always choose the approach best suited to the individual patient and variables in existence at the moment of decision. These guidelines are applicable to all physicians who are appropriately credentialed and address the clinical situation in question, regardless of specialty.

Guidelines are developed under the auspices of the International Pediatric Endosurgery Group Surgeons and its various committees, and approved by the Executive Committee. Each guideline is developed with a systematic approach and includes a review of the available literature and expert opinion when published data alone are insufficient to make recommendations. All guidelines undergo appropriate multidisciplinary review prior to publication, and recommendations are considered valid at the time of publication. Because new development in medical research and practice can change recommendations, all guidelines undergo scheduled, periodic review to reflect any changes. The systematic development process of clinical practice guidelines began in 2007 and will be applied to all revisions as they come up for scheduled review, as well as all new guidelines.

Definition and Nature of Inguinal Hernia and Hydrocele

During fetal life, the descent of the testis into the inguinal canal and scrotum brings a small pouch of peritoneum alongside.³ This peritoneal extension is the processus vaginalis. In females, the formation of the labia has the same peritoneal remnant referred to as the canal of nuck.⁴ The peritoneal canals are obliterated in up to 95–98% of fetuses obliterated before birth.^2,3

Failure of this peritoneal fusion results in a spectrum of abnormalities. The degree of fusion failure results in either a hydrocele (hydro: water; cele: collection of fluid) within the scrotum=labia, sometimes extending into the groin or a hernia (descent of visceral contents into the inguinal canal and or scrotum=labia).

There are two types of inguinal hernia: direct, where the abdominal musculature is weak and visceral contents protrude through the wall of the inguinal canal and exit via the superficial inguinal ring, and indirect inguinal hernia, where visceral contents pass into the patent processus vaginalis (PPV) via an open deep inguinal ring and exit via the superficial inguinal rings. The latter is the most common finding in children.^1–5 Inguinal hernia occurs 9 times more commonly in boys than in girls, with the majority occurring on the right (60%), left (25%), and 15% are bilateral.^6,7

Diagnosis and Workup

Inguinal hernia

Patients are initially assessed by history and clinical examination. History often reveals a sudden, intermittent appearance of a bulge in the groin during nappy change or when drying after bathing. This is usually seen with straining or crying. The infant or child may appear in discomfort at such times. The child may develop an irregular bowl habit. In cases of incarceration with obstruction, the child may be vomiting and have abdominal distention. Clinical examination may be normal. Evidence of recent herniation is indicated by swelling within the inguinal canal structures, often referred to as a thickened spermatic cord.9 The latter most likely represents edema or fluid within the empty processus vaginalis and surrounding tissue as well as cremasteric muscular hypertrophy. If the hernia is incarcerated at the time of examination, a mass is usually felt within the groin. An inability to palpate the upper border of the mass is suggestive of herniation of visceral contents from within the peritoneal cavity, with the caveat to this being an inguinal hernia in a premature infant where tissue layers are thin and the inguinal canal is very short.⁹

The scrotum may also appear larger than the contralateral side if the hernia has descended to within the scrotal sac. In females, a small mobile mass often appears in the groin or labia, which usually represents an ovary. The risk to hernia and its contents becoming incarcerated is greatest in early infancy.¹⁰ If not successfully reduced, incarceration can lead to obstruction and necrosis. Such patients may present in acute bowel obstruction and require resuscitation. Persistent pressure on delicate cord structures can also lead to testicular vessel compromise and testicular infarction.¹¹ Premature infants have an incarceration risk of up to 30%.^12–14 The latter is halved in older children.

Hydrocele

History and clinical examination is important when differentiating hydrocele from hernia. Parents often describe a painless swelling within the scrotum appearing larger in the evening than the morning or following a viral infection. Examination reveals a fluctuant painless swelling, which may or may not be reducible. Transillumination reveals a fluid filled scrotum, which may be bilateral. Palpation above the swelling is usually possible, except in the case of a large abdominoscrotal hydrocele.

Investigations

The diagnosis for both inguinal hernia and hydrocele is usually clinical. In those older children with indeterminate pain, ultrasound may play a role.¹⁵ Others have also advocated the use of ultrasound in detecting contralateral PPV prior to hernia surgery in children.¹⁶ An abdominal radiograph may confirm bowel obstruction in patients with obstructed hernia. Laparoscopy may be considered as a diagnostic investigation in some carefully selected patients, as it will require general anesthesia.

Patient Selection

Inguinal hernia

Surgery is indicated for all pediatric patients where a diagnosis of inguinal hernia has been made. Premature infants with hernia are usually operated on prior to leaving the neonatal intensive care unit (NICU) by most surgeons.¹⁷ Infants under the age of 3 months are usually booked on a soonavailable operating list. Older children with few symptoms can be booked electively.

Hydrocele

The selection for surgery with hydrocele is mostly age dependent. Most surgeons advocate observation in the majority of infants less than 12 months.¹⁷ Others may continue to be observed for longer, as the majority of PPV will close within the first 12–24 months of life.^2–7

Risks or Potential Benefits/Hazards

Inguinal hernia

Risks of not performing surgery for inguinal hernia include bowel incarceration=necrosis, as well as possible testicular=ovarian compromise and=or necrosis.^{12–14,18,19} Risks of surgical procedures for inguinal hernia and hydrocele can result in both short- and long-term complications. Short-term complications include wound infection, injury to the vas and testicular vessels, as well as injury to the genitofemoral nerve, resulting in chronic pain.²³ Injury to other intra-abdominal structures is possible if the procedure involves laparoscopy. Reoccurrence of hernia is both a short and long term observation and is between 1 and 2%,^1,7 though higher in premature infants.²⁰ Testicular ascent following inguinal tissue contracture is another possible long-term problem.

Hydrocele

Risks of nonoperative management in hydrocele include scrotal enlargement and potential hernia formation. Hydrocele is considered a benign condition, though abdominoscrotal hydrocele may affect testicular morphology (i.e., flattening or elongation), if left untreated.²¹ In adults, hydrocele can be associated with an arrest of spermatogenesis²² Risks of inguinal surgery similarly apply to hydrocele surgery (see above).

Indications

There is no place in children for conservative management of inguinal hernia. Operative indication is often delayed, though this is usually age dependent.¹⁹ Hydrocele in infancy, however, is associated with a spontaneous resolution of up to 2 years of age. A conservative approach is often adopted primarily. Surgery is offered for congenital hydrocele after the age of 2 years for reasons of persistent enlargement of the fluid collection and possible risk of hernia later in life. Surgical treatment is offered for hernia to prevent the risk of incarceration, obstruction, and resulting in necrosis of hernial contents as well as surrounding cord structures. In females, torsion of the ovary is also possible.^{12–14,18,19}

Contraindications (Absolute and Relative)

There are no absolute or relative contraindications to inguinal hernia or hydrocele repair. Repair is often delayed for other reasons, such as fitness for surgery or abdominal pressure problems, as occurs in reduction of large abdominal wall defects.

Treatment and Options

Inguinal hernia

Depending on the age of the patient and the history of incarceration, the patient may be admitted and the operation carried out within 24–48 hours. If the hernia is easily reducible and the child older than 3 months, the procedure is usually carried out electively. If a patient presents with incarceration, an attempt at reduction should be made. Reduction should be performed by a trained physician, using analgesia and or sedation. ²⁴ If a hernia remains incarcerated, an operative approach is indicated to reduce and inspect the integrity of hernial contents as well as ligate the hernial sac. Reduction may spontaneously occur prior to a manual attempt, if the infant’s buttocks are elevated slightly to assist in the reduction of hernial contents. The hernia is palpated distally while the clinician’s fingers locate the proximal neck of the hernia. Compression of the hernia can then occur. The pressure is maintained slowly and consistently until the hernia is reduced. For those with incarceration, the chance of reincarceration is reported to be as high as 15%, if surgery is delayed more than 5 days.²⁵

Operative approaches to inguinal hernia

Inguinal hernia in children can be repaired through either an open or laparoscopic technique. The laparoscopic can be either transperitoneal or transabdominal preperitoneal (TAPP).

Open technique of inguinal hernia repair

An inguinal crease incision is made on the ipsilateral side to the symptomatic inguinal hernia.²⁶ The procedure involves the separation of the hernial sac from the surrounding cord structures, including cremasteric muscle, vas deferens, and the testicular vessels or round ligament. A ligature is usually applied to the separated sac and the distal sac divided. The presence of a contralateral ppv (cPPV) or hernia can be identified by the passage of a 70-degree angled telescope through the hernia sac prior to ligation. The addition of the pneumoperitoneum can allow visualization of the opposite side to determine its patency.²⁷ Complications of the open approach include wound infection, bleeding, ilioinguinal nerve injury, vas and vessel damage, and recurrence.

Laparoscopic technique of inguinal hernia repair

The laparoscopic approach can be performed either transperitoneally ^28,31,32, or through a preperitoneal approach with transperitoneal visualization.^29,30

Transperitoneal. The transperitoneal approach incorporates a telescope through an umbilical port allowing direct visualization of the deep inguinal rings, followed by the controlled passage of instruments either with or without the assistance of trocars. The technique affords confirmation of the diagnosis as well as inspection of the contralateral side for the presence of a hernia or ppv. The deep ring is then closed with either an absorbable or nonabsorbable suture either as purse string or similar.^28,31,32 A peritoneal flap closure is also possible from using this access method.³³

Preperitoneal. A small hook loaded with a suture is passed around the deep ring after incising a small inguinal skin incision. The passage of the suture is observed via an endoscope at the umbilicus.^29,30 The ligature is then brought extracorporally and tied, thus closing the hernial orifice.

Hydrocele

The surgical procedure is identical to that of open inguinal herniotomy. Some surgeons do advocate a scrotal approach for older children, though this may be associated with a higher recurrence rate. Once the PPV is ligated, an attempt should be made to empty the distal fluid, if not already drained. This often requires an incision distally down to the scrotal tunica vaginalis to release any residual fluid.

Recommendations (Based on Level of Evidence and Weight of Each Level)

The open method of inguinal hernia and hydrocele repair is a standard approach adopted worldwide for over five decades. Studies examining surgical outcome have no controls. Controversy currently exists in several aspects of pediatric hernia management, including (1) the need to detect and treat a potential contralateral patent deep ring; (2) the timing of surgery; and (3) to perform the operation open or via a laparoscopic=laparoscopic-assisted approach.

Supporting evidence

The majority of evidence to support clinical relevance for a patent cPPV is based on Type II-3 and Type 3 data, when bilateral exploration was widely performed.^34–38 The likelihood of developing a contralateral inguinal hernia is between 8 and 15%.^6–8 The laparoscopic evaluation via hernioscopy or umbilical laparoscopy detects cPPV in up to 30–50% of patients^28–31 and is, therefore, a similar finding to that in open contralateral surgery. Current levels of evidence do not demonstrate any increase in morbidity from the routine treatment of contralateral ppv or hernia when detected laparoscopically.

Evidence to support an optimal timing of hernia repair is either level II-3 or level III.^11–14 Atailored individual approach is usually required and is the unanimous conclusion from most studies. Early repair before discharge is warranted for in patients below 50 weeks in conceptual age and or with a previous history of incarceration. An urgent available list should be accessible for those under the age of 3 months.

Level I evidence comparing open and laparoscopic approaches to inguinal hernia surgery is limited. Small, single-blinded, randomized, controlled trials, to date, have highlighted areas both for and against laparoscopic repair of inguinal hernia.^39,40 Level 11-3 evidence suggests that transperitoneal laparoscopic inguinal hernia repair may have an advantage over open inguinal hernia in the ability to detect and simultaneously repair cPPV. The recurrence rate following laparoscopic repair, when compared to open, may also be higher. This is supported by level II-2 data that suggest this may be related to the experience of the surgeon.^41,42 The transabdominal extraperitoneal repair has some support for a lower recurrence rate, when compared to the traditional open procedure using level 11-2 evidence.^43,44

In summary, both level I and II-2 data confirm laparoscopy as possessing an ability to diagnose a contralateral PPV or hernia. Defining what may be clinical relevant and warrants treatment is not clear. Similarly, level II-3 evidence is also able to support an overdiagnosis of contralateral pathology in such cases and advocate no such intervention as being necessary.⁴⁵ A slightly higher recurrence rate appears to exist when comparing the transperitoneal to the extraperitoneal and open repair. This may be related to surgical experience. Advantages of a reduced injury to the vas and vessels, a reduction in testicular atrophy, and better cosmesis are not supported by current levels of evidence (see table below).

Expected post-treatment course

Following surgery for inguinal hernia and hydrocele in children, patients are expected to be free from hernia or scrotal swelling. The postoperative course appears to be similar for both open and laparoscopic methods of repair.^{6–8,39–42} The majority of procedures are performed on an outpatient basis, with an overnight stay reserved for those under 44–50 weeks in conceptual age.⁴⁶ The incidence of developing a metachronous hernia following unilateral inguinal hernia is in the region of 6–8%. This approaches 0% if the repair incorporates laparoscopy and a contralateral opening is identified and repaired. Patients can expect to resume normal activity within 48 hours following surgery.³⁹

Complications and treatment of complications

Short-term complications are rare following surgery for hernia or hydrocele. Injury to the vas deferens during inguinal or hydrocele repair is a potential risk,⁴⁵ with treatment requiring microsurgical repair. Visceral injury during laparoscopic repair is very rare and can be treated either by open or laparoscopic surgery. Recurrence following inguinal hernia surgery range is related to factors such as prematurity,²¹ increased abdominal pressure, postoperative wound infection, and hematoma, as well as surgical experience. The majority of postoperative recurrence is seen by 5 years.⁴⁶

References

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This guideline was prepared by the IPEG Standards and Safety
Committee and was reviewed and approved by the Executive Committee
of the International Pediatric Endosurgery Group (IPEG),
November 2009.

International Pediatric Endosurgery Group (IPEG) 11300 West Olympic Boulevard, Suite 600 Los Angeles, CA 90064 E-mail: ipegweb@ipeg.org