What is a sliding inguinal hernia?

What is a Sliding Inguinal Hernia?

A sliding inguinal hernia is a specific type of inguinal hernia where part of the hernial sac wall is formed by an intra-abdominal organ itself, rather than just peritoneum, with the most common organs being the sigmoid colon (62.5%), urinary bladder (12.5%), cecum (12.5%), and appendix (12.5%). 1, 2

Anatomical Definition and Mechanism

A sliding hernia occurs when a visceral organ forms a portion of the hernia sac wall, sliding through the inguinal canal along with the peritoneal covering. 1, 2 This differs from a standard indirect inguinal hernia where only peritoneum and its contents herniate through a patent processus vaginalis. 3

The sliding component means the organ is retroperitoneal or partially retroperitoneal and becomes incorporated into the hernia sac as it protrudes through the internal inguinal ring. 2

Epidemiology and Clinical Significance

• Incidence: Sliding inguinal hernias represent 9.4% of all inguinal hernias in males and only 2.9% in females. 4
• Overall frequency: Approximately 3.4% of all electively repaired inguinal hernias are sliding variants. 2
• Recurrence risk: Sliding inguinal hernias carry a significantly higher reoperation rate (6.0%) compared to non-sliding inguinal hernias (4.2%), making them an independent risk factor for recurrence. 4

Common Organs Involved

The organs that most frequently form sliding hernias include:

• Sigmoid colon (most common at 62.5% of sliding hernias) 2
• Urinary bladder (12.5%) - can present bilaterally and cause lower urinary tract symptoms including hesitancy, intermittency, and two-stage voiding requiring manual pressure on the scrotum 1, 5
• Cecum and ascending colon (12.5%) 1, 2
• Appendix (12.5%) 1, 2

Clinical Presentation

Patients with sliding inguinal hernias present similarly to standard inguinal hernias but may have organ-specific symptoms:

• Standard hernia symptoms: Groin pain, burning or aching sensation, heavy or dragging sensation worsening throughout the day, visible bulge that may reduce when supine 6
• Bladder involvement: Lower urinary tract symptoms including urinary hesitancy, intermittency, decreased scrotal size after voiding, need to manually compress scrotum to complete voiding 1, 5
• Colonic involvement: May present with bowel symptoms or simply as a large inguinoscrotal mass 2

Diagnostic Approach

• Physical examination: Palpation for bulge or impulse during coughing or straining is usually sufficient for diagnosing inguinal hernia 6
• CT imaging: The modality of choice when sliding hernia is suspected, particularly for bladder hernias which may show the classic "pelvic mickey mouse sign" 1
• Ultrasonography: Can help diagnose hernias when physical examination is equivocal, particularly useful for recurrent hernias or suspected complications 6

Surgical Considerations and Outcomes

The Lichtenstein tension-free mesh repair should be preferred over laparoscopic approaches for sliding inguinal hernias, as it demonstrates lower reoperation rates (HR 0.43 vs 0.70 for laparoscopic). 4

Key Technical Points:

• Most sliding hernias are repaired via open approach rather than laparoscopically, attributed to larger hernia size, associated complications, or recurrent hernias with adhesions 1
• The hernia sac should be opened to identify the sliding organ and prevent inadvertent injury 2
• Tension-free mesh techniques (Lichtenstein or Rutkow-Robbins) are appropriate and safe 2
• Risk of organ injury during repair is minimal when proper technique is used 2

Complications and Recurrence:

• When tension-free technique is employed, recurrence risk is similar to non-sliding hernias in some series 2, though population-level data shows higher reoperation rates overall 4
• Major surgical complications are uncommon 2
• Large bladder hernias can cause severe complications if untreated, including bladder incarceration, necrosis, hemorrhage, obstructive bladder dysfunction, and renal failure 5

Common Pitfalls

• Failure to recognize sliding component intraoperatively can lead to inadvertent organ injury - always open and inspect the sac when sliding hernia is suspected 2
• Choosing laparoscopic over open repair may increase recurrence risk in sliding hernias 4
• Delaying diagnosis of bladder hernias can result in progressive urinary complications and potential renal dysfunction 5