eMedicine Specialties > Pediatrics: Surgery > Urology

Hydrocele and Hernia in Children

Author: Sean Collins, MD, Assistant Professor or Urology, Department of Urology, Louisiana State University Health Sciences Center - New Orleans
Coauthor(s): Joseph Ortenberg, MD, Director of Urologic Education, Departments of Urology and Pediatrics, Children's Hospital of New Orleans; Professor of Urology and Pediatrics, Louisiana State University School of Medicine; Chip Roth, MD, Resident, Department of Urology, Ochsner Clinic Foundation, Louisiana State University
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Updated: Jun 16, 2006

Introduction

Background

A hydrocele is a collection of fluid within the processus vaginalis (PV), and it produces a swelling in the inguinal region or scrotum. An inguinal hernia occurs when abdominal organs protrude into the inguinal canal or scrotum. Inguinal hernia and hydrocele share a similar etiology and pathophysiology and may coexist.

In the healthy neonate after birth, the testicle is surrounded by a closed cavity, which is the tunica vaginalis (TV) of the scrotum. In postnatal life, this is a potential space that should not communicate with the peritoneum.

Pathophysiology

During fetal development, the testicle is located within the peritoneal cavity. As the testicle descends through the inguinal canal and into the scrotum, it is accompanied by a saclike extension of peritoneum, otherwise known as the PV. After the testicle descends, the PV obliterates in the healthy infant and becomes a fibrous cord with no lumen. Thus, the scrotum should lose its connection with the abdomen. Without this connection, neither abdominal organs nor peritoneal fluid should make their way into the scrotum or inguinal canal. If the PV does not close, it is referred to as a patent processus vaginalis (PPV).

If the PPV is small in caliber and only large enough to allow fluid to pass, the condition is referred to as a communicating hydrocele. If the PPV is larger, allowing ovary, intestine, or other abdominal contents to protrude, the condition is referred to as a hernia. Multiple theories exist regarding the failure of PV closure. Smooth muscle has been identified in PPV tissue and not in normalperitoneum. The amount of smooth muscle present may correlate with the degree of patency. For example, higher amounts of smooth muscle have been found in hernia sacs than in the PPV of hydroceles. Investigation continues to determine the role of smooth muscle in the pathogenesis of this condition.

Frequency

United States

Incidence is 10-20 hernias per 1000 live births. While hernia location is more common on the right side, as many as 10% are bilateral.

Mortality/Morbidity

The greatest risk associated with a hernia is that the intestine becomes trapped inside the sac. This condition is referred to as incarceration. If left incarcerated, the bowel may become edematous. The increased pressure may impair venous drainage, leading to more edema, which may impair arterial inflow of the bowel and possibly the testis. When perfusion of the bowel is affected, a strangulated hernia exists. A strangulated hernia can lead to perforated bowel, peritonitis, sepsis, and death. As such, an incarcerated or strangulated hernia is a surgical emergency. If a strangulated bowel is reduced surgically at an early stage, viability may be preserved, and bowel resection may be avoided.

In females, the ovary or fallopian tube can enter hernia sacs and become incarcerated or strangulated. An incarcerated ovary is an urgent problem that may result in infarction of the ovary and pain; however, an incarcerated ovary does not carry the same risk of perforation and sepsis as seen with bowel perforation.

Sex

• Hernias are 6 times more common in boys than in girls.
• Bowel incarceration is more common in females than in males.
• In females an ovary or fallopian tube incarcerates more frequently than bowel. Therefore, overall incidence of bowel strangulation is lower in females than in males.

Age

Incidence of PPV decreases with age. In newborns, 80-94% have a PPV. Hernias are 20 times more common in infants weighing less than 1500 g than in the general population. As many as 30% of adults have a PPV at autopsy. Why all PPVs do not develop into a hernia or hydrocele is not understood.

Clinical

History

A bulge in the groin or scrotal enlargement is the classic presentation of hernia or communicating hydrocele. Pain generally is not a prominent feature unless a hydrocele is infected or a hernia is strangulated. Frequently, parents report an intermittent bulge. The bulge may reduce at night while lying supine. A history of vomiting, colicky abdominal pain, or obstipation suggests bowel obstruction, which may occur with an incarcerated or strangulated hernia.

Physical

Examine the child in the supine and standing positions. If a bulge is apparent in the standing position, lay the child in the supine position. Resolution of the bulge in the supine position suggests a hernia or a hydrocele with a patent processus vaginalis (PPV).

• If the bulge is not readily apparent, perform a maneuver to increase intraabdominal pressure. For example, have children blow up balloons or press on their abdomens. Raising children's hands above their heads causes them to struggle and may reveal occult bulges that are not visible otherwise.
• Transillumination of the scrotum displays fluid in the TV, suggesting a hydrocele; however, this test is not completely reliable because the bowel also may appear to transilluminate.
• Bowel sounds in the scrotum are strongly suggestive of a hernia.
• A bulge below the inguinal ligament is suggestive of lymphadenopathy.
• Examiners may try to elicit the silk glove sign. Gently passing the fingers over the pubic tubercle may reveal a PPV. The thickened cord of a hernia or hydrocele sac within the spermatic cord provides the feel of 2 fingers of a silk glove rubbing together.
• Unless a PPV results in hernia or hydrocele, it often goes undetected upon physical examination.

Causes

Most hernias and hydroceles in children are due to idiopathic failure of the PV to close. Any condition that increases intraabdominal pressure can delay or inhibit this closure.

• The following is a list of conditions associated with hernia or hydrocele:
  • Cryptorchid testis
  • Hypospadias
  • Ambiguous genitalia
  • Epispadias and exstrophy of the bladder
  • Ventriculoperitoneal shunt
  • Liver disease with ascites
  • Abdominal wall defects
  • Continuous ambulatory peritoneal dialysis
  • Prematurity
  • Low birth weight
  • Family history
  • Hydrops
  • Meconium peritonitis
  • Chylous ascites
  • Cystic fibrosis
  • Connective tissue disease
  • Mucopolysaccharidosis
• Reactive hydroceles cause inflammation and fluid accumulation around the testicle and can develop for the following reasons:
  • Trauma
  • Torsion
  • Infection (eg, epididymoorchitis)
  • Abdominal or retroperitoneal operations that impair lymphatic drainage
• Hernia classification
  • Indirect hernias come through the internal ring and are caused by failure of the PV to obliterate. Indirect hernias compromise most inguinal hernias in children. The hernia may extend down the inguinal canal toward the labia or scrotum.
  • Complete inguinal hernias are indirect hernias that extend into the scrotum. The anatomic defect is similar to the defect of a communicating hydrocele, although the PPV is more widely patent in hernias.
  • Direct hernias protrude directly through the floor of the inguinal canal and are medial to the inferior epigastric vessels. In children, these hernias are rare and usually observed only after another inguinal surgery.
• Hydrocele classification
  • Communicating hydroceles involve a PPV that extends all the way into the scrotum. In this case, the PPV is continuous with the TV, which surrounds the testicle. The anatomic defect is identical to the defect with an indirect hernia. However, the communication is smaller so only fluid accumulates.
  • Noncommunicating hydroceles contain fluid confined to the scrotum within the TV. The PV is obliterated so the fluid does not communicate with the abdominal cavity. Such hydroceles are common in infants, and the hydrocele fluid is usually reabsorbed before the infant is aged 1 year.
  • Reactive hydroceles are noncommunicating hydroceles that develop from some inflammatory condition in the scrotum.
  • Hydrocele of the cord occurs when the PV obliterates above the testicle, but a small communication with the peritoneum persists. A saclike area within the inguinal canal fills with fluid. The fluid does not extend into the scrotum.
  • Hydrocele of the canal of Nuck occurs in girls when fluid accumulates within the PV in the inguinal canal.
  • Abdominoscrotal hydrocele occurs because of a miniscule opening in the PV. Fluid enters the hydrocele and becomes trapped. The hydrocele continues to enlarge and eventually extends upward into the abdomen.

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