Intestinal volvulus refers to the 360°–720° twisting of a segment of intestinal loop and its mesentery around the axis of the mesentery, resulting in a closed-loop intestinal obstruction. It involves both mechanical obstruction of the intestinal lumen and compromised mesenteric blood circulation, making it a rapidly progressive and dangerous form of intestinal obstruction. The most common sites for intestinal volvulus are the small intestine and the sigmoid colon, with distinct clinical characteristics for each. This section focuses primarily on small intestinal volvulus.
Etiology
The primary causes of intestinal volvulus are as follows:
Anatomical Factors
These include postoperative adhesions and congenital malrotation of the midgut.
Physical Factors
On the basis of the aforementioned anatomical factors, the weight of the intestinal loop itself can predispose to volvulus. Situations such as having a full meal with indigestible food content within the intestinal lumen or the presence of intestinal tumors can act as additional contributing factors.
Motility Factors
Hyperactive intestinal peristalsis or sudden changes in body position may lead to asynchronous movements of the intestinal loops. This can cause twisting in intestinal loops that are already anchored at certain fixed points and have sufficient weight.
Clinical Presentation
Intestinal volvulus is a combination of closed-loop obstruction and strangulated obstruction, characterized by an abrupt onset and rapid progression. Severe and persistent abdominal pain begins suddenly, without intermittent relief, and early shock may also occur. In cases of small intestinal volvulus, symptoms include acute and severe cramping abdominal pain, often described as continuous with episodes of exacerbation. Mesenteric traction can cause pain to radiate to the lower back. Vomiting is frequent, abdominal distension is evident, and it is often more pronounced in one localized area. Palpation of the abdomen may reveal a tender, distended intestinal loop. Bowel sounds are reduced, with "rushes and tinkles" (gas and fluid sounds) being occasionally audible.
Abdominal X-rays usually show features consistent with strangulated intestinal obstruction. Specific signs, such as the displacement of the jejunum and ileum, or the arrangement of small convoluted loops resembling a "coiled spring," may be visible. CT imaging can further aid in establishing the diagnosis.
Treatment
Intestinal volvulus represents a severe form of mechanical intestinal obstruction that can rapidly progress to mesenteric strangulation and intestinal necrosis. Timely reduction or surgical intervention is essential. Post-reduction, careful monitoring of blood circulation recovery in the affected bowel is necessary. For long segments of the intestine with uncertain viability, efforts to relieve vascular spasm and observe potential for recovery can help preserve as much of the small intestine as possible. Segments of intestine confirmed to be necrotic require resection, and primary anastomosis of the small intestine may be performed following the resection.