Gut Malrotation, Nonrotation and Volvulus for USMLE

Summary

This video explains Malrotation of the gut, focusing on its embryology, types, causes, symptoms, and treatment. Malrotation occurs when the intestines do not properly rotate around the superior mesenteric artery during fetal development, leading to potential complications like volvulus and duodenal obstruction. Symptoms often present early in infancy and include bilious vomiting, abdominal pain, and bloody stool. Diagnosis involves imaging techniques like X-rays, barium swallow, and ultrasound. The primary treatment is the Ladd procedure, aimed at correcting the mesenteric base and removing Ladd bands. Prognosis is generally favorable, with most cases resolving post-surgery.

Takeaways

• 😀 Malrotation occurs when the gut fails to rotate normally around the superior mesenteric artery during fetal development.
• 😀 The normal gut rotation begins at around 6 weeks and involves a 270° rotation, positioning the cecum in the right lower quadrant.
• 😀 There are two types of gut rotation abnormalities: non-rotation and malrotation. Non-rotation is less serious, while malrotation can lead to severe complications.
• 😀 In non-rotation, the small intestine is on the right side and the colon on the left side, but this condition is typically less dangerous.
• 😀 Malrotation is associated with a narrow mesenteric base, which can lead to volvulus, a twisting of the gut that can cause necrosis and ischemia.
• 😀 LAD bands (Ladd’s bands) in malrotation can cause obstruction, especially to the duodenum, a critical complication not seen in non-rotation.
• 😀 The main symptoms of malrotation in infants include bilious vomiting, abdominal pain, and distension. Bloody stool indicates a serious complication such as necrosis.
• 😀 Malrotation is more common in infants, with volvulus occurring in 22% of children and 12% of adults. The condition requires prompt medical attention.
• 😀 Diagnosis often involves imaging techniques, with the barium swallow showing a corkscrew appearance and ultrasound revealing the whirpool sign.
• 😀 Treatment for malrotation is primarily surgical, involving the Ladd procedure, which widens the mesenteric base and removes LAD bands, reducing the risk of volvulus.
• 😀 Prognosis for malrotation is generally good, with an 89% resolution rate, but mortality can rise to 3-9% if necrosis or other complications like prematurity are present.

Q & A

What is malrotation of the gut?

Malrotation of the gut occurs when the intestines fail to rotate properly during embryonic development, specifically around the superior mesenteric artery. This results in abnormal positioning of the intestines, which can lead to complications like volvulus and obstruction.

What is the normal embryological rotation of the gut?

Normal gut rotation starts at 6 weeks, with the gut gradually enlarging and protruding into the yolk sac. At 9 weeks, the gut rotates 90° around the superior mesenteric artery, followed by an additional 180° rotation, totaling a 270° rotation by 12 weeks.

What is the difference between non-rotation and malrotation?

In non-rotation, the gut fails to rotate entirely, leading to the small bowel being on the right and the colon on the left side, which is typically less severe. In malrotation, the gut rotates partially but fails to descend fully, causing the cecum to remain in the upper right quadrant and leading to potential complications.

What are the main complications associated with malrotation?

The primary complications of malrotation are volvulus, caused by the narrow mesenteric base, and duodenal obstruction, often due to Ladd bands, which are abnormal bands of tissue that compress the duodenum.

What is volvulus, and why is it a concern in malrotation?

Volvulus occurs when the intestines twist on themselves due to a narrow mesenteric base, which is common in malrotation. This can lead to ischemia, necrosis, and potentially life-threatening conditions if not treated promptly.

What is the clinical presentation of malrotation in infants?

In infants, malrotation typically presents with bilious vomiting, abdominal pain, distension, and in severe cases, bloody stools. The presence of bloody stools may indicate necrosis, which is a sign of serious complications like sepsis.

How can malrotation be diagnosed?

Malrotation can be diagnosed using a variety of imaging techniques, including X-rays, barium swallow/enema, ultrasound, and CT scans. The barium swallow often shows a corkscrew appearance, while ultrasound may reveal a whirlpool sign.

What is the significance of the 'double bubble' sign in barium studies?

The 'double bubble' sign is a radiological finding where two gas-filled bubbles appear in the stomach and duodenum, indicating a duodenal obstruction. This sign is not specific to volvulus but suggests some form of duodenal blockage.

What is the preferred treatment for malrotation?

The preferred treatment for malrotation is the Ladd procedure, a surgery that involves widening the mesenteric base to prevent volvulus and removing Ladd bands to relieve duodenal obstruction. An appendectomy is also performed to prevent future complications.

What are the risks and prognosis associated with malrotation surgery?

The risks of surgery include short bowel syndrome (if large sections of the intestines are removed) and bowel adhesions leading to future obstructions. The prognosis is generally good, with an 89% recovery rate and a low recurrence of volvulus (1.8% to 8%). The mortality rate is around 3–9%, depending on the severity of associated complications.