PAEA Surgery End Of Rotation (EOR) Practice Exam

In a Richter hernia, what is the likely result when a portion of bowel protrudes but the lumen remains patent?

1. Complete bowel obstruction

2. Spontaneous resolution

3. Usually gangrenous necrosis

4. Enlargement of the hernia defect

The correct answer is: Usually gangrenous necrosis

In a Richter hernia, there is a specific scenario in which a segment of the bowel wall protrudes through the hernial sac, but only part of the bowel is involved while the lumen remains patent. This unique feature means that the affected bowel segment's blood supply may be compromised, particularly if continued pressure or strangulation occurs. As a result, even when the lumen isn't obstructed, the isolated section can easily become ischemic due to inadequate blood flow, leading to gangrene. Gangrenous necrosis is the breakdown of tissue due to lack of blood supply, and in the case of a Richter hernia, it is more likely to occur because the affected portion does not have any drainage or potential for decompression, unlike a more common bowel obstruction. This makes the risk of ischemia and subsequent necrosis a significant concern. Understanding the nature of this type of hernia helps in anticipating the surgical urgency involved, as timely intervention is crucial to prevent bowel resection due to necrosis.