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USMLE® Step 2 Question of the Day: Endoscopic repair

Osmosis Team
Jan 10, 2024

We're back with a USMLE® Step 2 CK Question of the Day! Today's case involves a 72-year-old man presenting with groin pain and bulging, exacerbated by standing. With a diagnosis of femoral hernia, the patient is set for endoscopic repair under spinal anesthesia. Discover the intricacies of this procedure and identify the critical structure at risk of injury during the repair. Can you pinpoint the anatomical concern in this surgical scenario?

A 72-year-old man presents to the office because of pain and bulging in his groin. The patient reports that standing exacerbates the pain. The patient is otherwise healthy and has never had surgery. He does not take any medications. Vitals are within normal limits. Physical examination shows a bulge in the groin that is erythematous and painful to palpation. Scrotal examination is within normal limits. After further evaluation, the patient is diagnosed with a femoral hernia and is scheduled for an endoscopic repair under spinal anesthesia. Which of the following structures is at risk of injury in this patient during the repair?

A. Ilioinguinal nerve

B. Iliohypogastric nerve

C. Genitofemoral nerve

D. Aberrant obturator artery

E. Pudendal nerve

Scroll down for the correct answer!

The correct answer to today's USMLE® Step 2 CK Question is...

D. Aberrant obturator artery

Before we get to the Main Explanation, let's see why the answer wasn't A, B, C, or E. Skip to the bottom if you want to see the correct answer right away!

Incorrect answer explanations

Today's incorrect answers are...

A. Ilioinguinal nerve

Incorrect: The ilioinguinal, iliohypogastric, and genitofemoral nerves are at risk of injury during inguinal hernia repair, which can lead to chronic residual neuralgia and postoperative constrictive scar tissue in the surgical area. However, this patient is undergoing repair for a femoral hernia, which poses risk to a different key structure.

B. Iliohypogastric nerve

Incorrect: The ilioinguinal, iliohypogastric, and genitofemoral nerves are at risk of injury during inguinal hernia repair, which can lead to chronic residual neuralgia and postoperative constrictive scar tissue in the surgical area. However, this patient is undergoing repair for a femoral hernia, which poses risk to a different key structure.

C. Genitofemoral nerve

Incorrect: The ilioinguinal, iliohypogastric, and genitofemoral nerves are at risk of injury during inguinal hernia repair, which can lead to chronic residual neuralgia and postoperative constrictive scar tissue in the surgical area. However, this patient is undergoing repair for a femoral hernia, which poses risk to a different key structure.

E. Pudendal nerve

Incorrect: The pudendal nerve is at risk of injury during sacrospinous ligament fixation or pelvic reconstructive procedures, during which sutures are placed in the arcus tendineus fasciae pelvis. However, this patient is undergoing repair for a femoral hernia, which poses risk to a different key structure.

Main Explanation

This patient with pain and bulging in the groin is found to have a femoral hernia. During femoral hernia repair, sometimes an artery called the aberrant, or accessory, obturator artery can be injured. Typically, the obturator artery branches from the internal iliac artery. In up to 20% of people, however, there can be an additional branch coming from either the inferior epigastric artery or external iliac artery that either replaces the obturator artery or joins it; this phenomenon is called an aberrant or accessory obturator artery. In these patients, the artery runs in close proximity to the femoral ring and courses along the superior pubic rami; so, during hernia repair, it can be injured or stapled.

When injury occurs, the artery retracts, making it exceedingly difficult to locate and ligate, resulting in uncontrolled bleeding. This artery has been referred to as corona mortis, which means “crown of death,” as injury to it can be fatal.

aberrant obturator

Major takeaway

During femoral hernia repair, sometimes an artery called the aberrant, or accessory, obturator artery (which runs in close proximity to the femoral ring and courses along the superior pubic rami), can be injured or stapled. This variant is found in about 20% of patients.

References

Moore, K. L., Dalley, A. F., & Agur, A. (2017). Clinically oriented anatomy (8th ed.). Lippincott Williams and Wilkins

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