Topographic anatomy of hernias

Inguinal hernias and the anatomy of the inguinal canal

Inguinal hernias lead in frequency among all abdominal wall hernias. Their topography is closely related to the anatomy of the inguinal canal. The key landmark for the surgeon is the inferior epigastric vessels.

• Indirect hernias originate lateral to these vessels. They enter the canal through the deep inguinal ring (fossa inguinalis lateralis), pass through it entirely, and emerge from the superficial ring.
• Direct hernias emerge medial to the vessels, in the area of Hesselbach's inguinal triangle. They rupture the posterior wall of the canal through the medial fossa (fossa inguinalis medialis), bypassing the deep ring.

In surgical treatment, access is achieved through an incision 10–12 cm long, 2 cm above the inguinal fold. Layer-by-layer dissection includes the skin, subcutaneous tissue, and the deep layer of the superficial fascia. A mandatory step is the transection and ligation of the superficial epigastric vessels (a. et v. epigastricae superficiales), after which the aponeurosis of the external oblique muscle is exposed. Opening of the canal is performed along a grooved probe.

The most critical stage of the operation is repair of the posterior wall (e.g., Bassini technique). The posterior wall is the weakest point, so it is reinforced by suturing the "triple layer" (internal oblique and transversus abdominis muscles along with the transversalis fascia) to the inguinal ligament posterior to the spermatic cord.

Umbilical hernias and hernias of the linea alba

Due to narrow hernia orifices in the umbilical ring and the linea alba, parietal incarceration (Richter's hernia) frequently occurs. Only a portion of the intestinal wall enters the ring. The intestinal lumen remains open, and the passage of contents is not impaired, which makes the clinical picture insidious and greatly complicates diagnostics.

The pathogenesis of incarceration develops rapidly:

1. Compression of tissues in the narrow orifice causes venous stasis and edema.
2. The hernia becomes irreducible, and arterial blood flow is disrupted.
3. A toxic hemorrhagic effusion accumulates in the sac — "hernia water".
4. The final cascade is infection, severe intoxication, and necrosis of the incarcerated organ.

A feature of linea alba hernias: they can exist for a long time at the preperitoneal lipoma stage. A true hernia sac is absent in this case, which can lead the surgeon to diagnostic misinterpretation.

Internal abdominal hernias

Internal hernias occur when organs protrude into natural peritoneal recesses (recessus) or mesenteric defects. Clinically, they are insidious: symptoms range from mild discomfort to acute intestinal obstruction. The gold standard for diagnosis is CT.

• Paraduodenal hernias (53% of cases). Left-sided ones emerge through Landzert's fossa, lying posterior to the inferior mesenteric vein. On CT, they appear as a cluster of loops behind the stomach with anterior displacement of the vein. Right-sided ones form through Waldeyer's fossa, posterior to the superior mesenteric artery, and are often associated with a non-rotated small intestine.
• Transmesenteric hernias. They occur in mesenteric defects (in adults, often after surgeries, such as Roux-en-Y anastomoses). They are characterized by a high risk of developing volvulus.
• Treitz's hernia. It forms in the area of the duodenojejunal flexure, where Treitz's recess (recessus duodenojejunalis) enlarges and turns into a capacious hernia sac.

Class and exam questions

What else to study on this topic

• Topography and contents of the hepatoduodenal ligament
• Intestinal rotation anomalies (malrotation) and their CT signs
• Anatomy of the ileocecal angle recesses and the intersigmoid recess
• Differential radiological diagnostics of mesenteric lymphangioma and ascites
• The role of the greater omentum in localizing peritonitis and metastasis spread

Other topics in the "Additional Topics" section

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.