Gastroenterology · Abdominal Wall Hernias
The facts most likely to be tested
An indirect inguinal hernia occurs lateral to the inferior epigastric vessels and passes through the internal inguinal ring due to a patent processus vaginalis.
A direct inguinal hernia occurs medial to the inferior epigastric vessels within Hesselbach's triangle due to a weakness in the transversalis fascia.
Incarcerated hernias are non-reducible but lack signs of ischemia, whereas strangulated hernias present with systemic toxicity, fever, tachycardia, and overlying skin erythema.
Strangulated hernias represent a surgical emergency requiring immediate laparotomy or laparoscopic repair to prevent bowel necrosis and perforation.
Physical examination of an inguinal hernia is best performed with the patient in a standing position and utilizing the Valsalva maneuver to increase intra-abdominal pressure.
Ultrasound is the first-line imaging modality for patients with an equivocal physical exam, while CT scan is preferred if complications like bowel obstruction are suspected.
Elective surgical repair is indicated for all symptomatic inguinal hernias to prevent the risk of future incarceration or strangulation.
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A 65-year-old male presents to the emergency department with a 6-hour history of severe, constant right groin pain and nausea. He has a known history of a reducible right-sided bulge that has been present for years. On physical exam, he is febrile and tachycardic, with a tender, erythematous, non-reducible mass located medial to the pubic tubercle. The overlying skin is warm and the patient exhibits guarding on abdominal palpation.
What is the most appropriate next step in management?
Emergent surgical consultation and operative repair
The patient's presentation of a non-reducible hernia with systemic signs (fever, tachycardia) and local skin changes (erythema) is diagnostic of a strangulated hernia, which is a surgical emergency.
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Etiology / Epidemiology
Most common hernia in both sexes; indirect is the most common type overall. Risk factors include increased intra-abdominal pressure (COPD, chronic cough, constipation).
Clinical Manifestations
Painless or aching groin bulge that worsens with Valsalva maneuver. Silk glove sign is a classic pediatric finding.
Diagnosis
Clinical diagnosis; ultrasound is the imaging modality of choice if the physical exam is equivocal.
Treatment
Surgical repair is the definitive treatment. Strangulation requires emergent surgical intervention.
Prognosis
Recurrence rates are low (<5%) with mesh repair. Bowel ischemia is the primary life-threatening complication.
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Epidemiology & Etiology
Inguinal hernias account for 75% of all abdominal wall hernias. Indirect hernias are more common in males and often congenital due to a patent processus vaginalis. Direct hernias are acquired, typically occurring in older adults due to weakening of the Hesselbach's triangle floor.
Pertinent Anatomy
The Hesselbach's triangle is defined by the inferior epigastric artery (lateral), the rectus abdominis (medial), and the inguinal ligament (inferior). Indirect hernias pass through the internal inguinal ring, while direct hernias protrude directly through the floor of the triangle.
Pathophysiology
Increased intra-abdominal pressure forces abdominal contents through a fascial defect. In indirect hernias, the contents enter the internal inguinal ring and may descend into the scrotum. Direct hernias occur due to connective tissue degradation, resulting in a protrusion that does not typically enter the scrotum.
Clinical Manifestations
Patients present with a groin bulge that increases with standing or coughing. Red flags include severe pain, erythema, or systemic signs of obstruction, which suggest incarceration or strangulation. The cough impulse is typically present on physical exam.
Diagnosis
Diagnosis is primarily clinical. If the diagnosis is unclear, ultrasound is the preferred initial imaging. CT scan is reserved for complex cases or to rule out other abdominal pathology when the diagnosis is uncertain.
Treatment
Asymptomatic or minimally symptomatic hernias may be managed with watchful waiting. Symptomatic or enlarging hernias require surgical repair (herniorrhaphy). Strangulated hernias are a surgical emergency requiring immediate reduction and repair to prevent bowel necrosis.
Prognosis
Elective repair has excellent outcomes with low morbidity. Chronic groin pain is the most common long-term complication. Bowel obstruction and ischemia are the primary risks if left untreated.
Differential Diagnosis
Femoral hernia: Located inferior to the inguinal ligament; higher risk of incarceration
Hydrocele: Transilluminates on physical exam
Lymphadenopathy: Firm, often tender, and associated with infection or malignancy
Varicocele: Feels like a 'bag of worms' and does not reduce
Lipoma: Soft, mobile, and does not change with Valsalva