What is the pathophysiology and management of an indirect inguinal hernia in a male over 40 years old?

Pathophysiology of Indirect Inguinal Hernia

Indirect inguinal hernias result from incomplete involution of the processus vaginalis, creating a patent processus vaginalis (PPV) through which intra-abdominal structures herniate laterally through the internal inguinal ring, passing within the spermatic cord coverings. 1

Anatomical Mechanism

• The hernia sac emerges through the internal inguinal ring lateral to the inferior epigastric vessels, distinguishing it from direct hernias which occur medially through Hesselbach's triangle 2

• The sac passes through the inguinal canal within the core of the spermatic cord, covered by internal spermatic, cremasteric, and external spermatic fasciae 3

• In males, the hernia may extend into the scrotum following the path of testicular descent 1

Congenital vs. Acquired Etiology

The etiology is predominantly congenital, even in adults, contrary to traditional teaching that adult indirect hernias are acquired. 4

• Asymptomatic PPV exists in 12% of adults undergoing laparoscopy for other conditions, with no significant increase in prevalence with age (22% under age 20,14% over age 50) 4

• The lack of age-related increase in PPV prevalence contradicts an acquired etiology, since acquired hernias should increase with age 4

• However, additional acquired factors contribute to hernia development in adults, as evidenced by the high recurrence rate after simple herniotomy alone (which works in infants but fails in adults) 4

• Neuromuscular dysfunction may play a role: specialized portions of the transversus abdominis muscle normally close the internal inguinal ring during abdominal contraction, and denervation or injury to this mechanism can precipitate hernia formation 5

Risk Factors in Adults Over 40

• Previous abdominal or groin surgeries increase risk through potential denervation of the protective neuromuscular closure mechanism 1, 5

• Activities that chronically increase intra-abdominal pressure can convert an asymptomatic PPV into a clinically apparent hernia 1

• Male sex confers significantly higher risk, with 55% of asymptomatic PPV occurring in males 4

• Right-sided predominance occurs in 59% of cases 4

Management Approach for Males Over 40

All symptomatic inguinal hernias require surgical repair to prevent life-threatening complications including incarceration and strangulation. 2

Urgent Assessment Priorities

• Immediately assess for incarceration/strangulation signs: irreducibility, tenderness, erythema, overlying skin changes, abdominal wall rigidity, fever, tachycardia 2

• Symptomatic periods exceeding 8 hours significantly increase morbidity, making time from onset to surgery the most critical prognostic factor 2

• Emergency surgery is mandatory for strangulated hernias, as delayed treatment beyond 24 hours dramatically increases mortality 6, 2

Elective Repair Considerations

• Both open and laparoscopic approaches (TEP or TAPP) are viable options, with choice depending on patient comorbidities, hernia characteristics, and surgeon expertise 1

• Unlike pediatric hernias where simple herniotomy suffices, adult repairs require mesh reinforcement due to acquired tissue weakness factors 4

• Examine both groins bilaterally, as contralateral hernias occur in 11-50% of cases 1

Common Pitfalls to Avoid

• Missing femoral hernias during examination, which carry the highest strangulation risk and require urgent surgical referral 2

• Underestimating strangulation risk based on hernia size alone—physical features do not consistently predict incarceration risk 1

• Delaying evaluation when any signs of strangulation are present; CT with contrast can predict bowel strangulation with 56% sensitivity and 94% specificity 1, 2