Hernias & Abdominal Wall
Tell a reducible bulge from an ischemic emergency, and know which always operate
Hernia basics and the strangulation emergency
Definition. A hernia is protrusion of a viscus (or omentum and preperitoneal fat) through a defect in the wall that normally contains it. The key question is always whether this is a harmless, reducible bulge or an ischemic emergency, and which hernias always go to the operating room.
- ReducibleContents slide back into the abdomen, spontaneously or with gentle pressure.
- IncarceratedStuck and non-reducible; may obstruct the bowel, but perfusion is still intact.
- StrangulatedBlood supply compromised → ischemia, necrosis, perforation. A surgical emergency.
Recognizing strangulation. Suspect it when a hernia becomes suddenly painful, tender, and irreducible, with overlying skin erythema and systemic signs (fever, tachycardia, leukocytosis), usually together with bowel obstruction. The next step is emergent surgical exploration to prevent bowel necrosis and perforation, with resection of any nonviable segment.
Never force a suspected strangulated hernia back in: reducing dead bowel hides the problem and risks perforation. An incarcerated hernia without toxic signs may be gently reduced with analgesia and sedation, followed by observation and early repair; if it will not reduce, operate.
Hernia as a cause of obstruction. An incarcerated hernia is the second most common cause of small bowel obstruction after adhesions, and the leading suspect when the patient has never had abdominal surgery. In any obstructed patient (distension, vomiting, high-pitched then absent bowel sounds), examine the groin, femoral region, umbilicus, and old incisions for a tender, irreducible bulge. A Richter hernia traps only part of the bowel wall (the antimesenteric border), so it can strangulate without causing complete obstruction.
Groin hernias: indirect, direct, and femoral
Indirect inguinal. The hernia enters the deep inguinal ring lateral to the inferior epigastric vessels, travels along the spermatic cord, and can descend into the scrotum. It is congenital, arising from a patent processus vaginalis, and is the most common hernia overall in both sexes, especially in infants (more so if premature) and younger males.
Direct inguinal. The hernia bulges medial to the inferior epigastric vessels through Hesselbach triangle, from acquired weakness of the transversalis fascia forming the canal floor. It occurs in older men, has a broad neck, rarely enters the scrotum, and does not pass through the deep ring. Chronic straining (cough, constipation, BPH, heavy lifting) promotes it.
Hesselbach triangle. Borders are the inferior epigastric vessels laterally, the lateral edge of the rectus abdominis medially, and the inguinal (Poupart) ligament inferiorly. Direct hernias protrude through this triangle of weakened floor.
MDs don't LIe: Medial = Direct, Lateral = Indirect, relative to the inferior epigastric vessels. Examination cannot reliably tell the two apart; the distinction is confirmed at operation and does not change the repair.
Femoral. The hernia passes below the inguinal ligament through the femoral canal, medial to the femoral vein (femoral triangle lateral to medial: nerve, artery, vein, empty space of the canal, lymphatics). It is more common in women, although indirect inguinal remains the most common groin hernia in women. The canal is narrow and rigid (inguinal ligament in front, pectineal ligament behind, lacunar ligament medially), so femoral hernias carry the highest risk of incarceration and strangulation, and all of them are repaired.
A groin mass below the inguinal ligament is femoral; above it is inguinal. The classic case is an elderly woman with a tender lump below the groin crease plus vomiting and distension.
| Feature | Indirect inguinal | Direct inguinal | Femoral |
|---|---|---|---|
| Route | Deep ring, lateral to inferior epigastric vessels | Hesselbach triangle, medial to inferior epigastric vessels | Femoral canal, below inguinal ligament, medial to femoral vein |
| Cause | Congenital: patent processus vaginalis | Acquired transversalis fascia weakness | Acquired; narrow, rigid canal |
| Typical patient | Infants, younger males; most common overall | Older men | Women, often elderly |
| Scrotal extension | Can descend into scrotum | Rarely | No; bulge in upper medial thigh |
| Strangulation risk | Present, especially in infants | Low (broad neck) | Highest |
| Repair | If symptomatic; infants repaired promptly | If symptomatic | Always |
Umbilical, incisional, and other wall hernias
Umbilical hernia. The defect is the umbilical ring. In infants it is common (more so in African American and premature infants) and most close spontaneously by age 2, so observation is appropriate; elective repair is reserved for defects persisting past about age 4–5 or the rare incarceration. Congenital hypothyroidism, Down syndrome, and Beckwith-Wiedemann syndrome are classic associations. In adults the hernia is acquired from obesity, ascites, or pregnancy, incarcerates more readily, and is more likely to need repair.
Incisional (ventral) hernia. This develops through a prior surgical incision where the fascia failed to heal. Risk factors are obesity, wound infection, poor surgical closure, and increased intra-abdominal pressure, plus anything that impairs healing (smoking, diabetes, steroids, malnutrition). Repair uses mesh, which lowers recurrence compared with suture repair alone.
- Epigastric: small defect in the linea alba above the umbilicus, often containing preperitoneal fat.
- Spigelian: through the fascia along the lateral edge of the rectus (linea semilunaris); lies beneath the external oblique, so it is easily missed and often needs ultrasound or CT.
- Obturator: thin, elderly women; presents as small bowel obstruction with medial thigh pain on internal rotation of the hip (Howship-Romberg sign); diagnosed on CT.
Hiatal hernias: sliding vs paraesophageal
Hiatal hernia is herniation of stomach through the diaphragmatic esophageal hiatus. It is often seen incidentally as a retrocardiac air-fluid level on chest radiograph and is characterized by barium swallow or upper endoscopy.
| Feature | Type I sliding | Paraesophageal (types II–IV) |
|---|---|---|
| Frequency | About 95% | The remainder |
| Anatomy | GEJ slides up above the diaphragm | II: GEJ stays in place while the fundus herniates beside it; III: GEJ and fundus both above; IV: other organs (colon, spleen) herniate |
| Main problem | GERD from loss of the antireflux barrier | Obstruction, gastric volvulus, incarceration, strangulation |
| Management | Medical (PPI, lifestyle); fundoplication if refractory | Surgical repair when symptomatic; emergent if volvulus |
Acute gastric volvulus in a paraesophageal hernia gives the Borchardt triad: severe epigastric pain, retching without vomiting, and inability to pass a nasogastric tube. This is a surgical emergency.
Repair indications and complications
Who goes to the operating room.
- Strangulation, or incarceration that will not reduce: emergent surgery.
- Symptomatic hernias (pain, discomfort, enlargement): elective repair.
- All femoral hernias, even when asymptomatic.
- Symptomatic paraesophageal hernias.
- Inguinal hernias in infants and children: prompt repair, because incarceration risk is high.
Watchful waiting is acceptable for small, asymptomatic or minimally symptomatic inguinal hernias in adults; many eventually become symptomatic and cross over to repair.
Technique. Elective groin repair is tension-free mesh, either open (Lichtenstein) or laparoscopic preperitoneal mesh; the laparoscopic route is favored for bilateral hernias and for recurrence after an open repair.
Complications. Recurrence; chronic groin pain from ilioinguinal nerve entrapment (open repair), with the genitofemoral and lateral femoral cutaneous nerves at risk laparoscopically; seroma or hematoma; surgical site infection; and urinary retention early after surgery, especially in older men. Injury to the spermatic cord can cause ischemic orchitis and testicular atrophy. Mesh reduces recurrence but can rarely become infected.