Mesenteric Volvulus Presenting as Rightlower Quadrant Pain
Published Online: May 25, 2007 - 1:34:34 AM (CDT)
Arie E. Pelta, MD Chief Resident General Surgery Department of Surgery North Shore Long Island Jewish Medical Center
Jay Yelon, MD Chief of Trauma and Critical Care and Attending Surgeon Department of Surgery North Shore University Hospital North Shore Long Island Jewish Health System Manhasset, NY
Rotational gut abnormalities are rare in adults, but the most common of such abnormalities in this population is midgut volvulus. Patients generally report significant abdominal pain, and prompt diagnosis is imperative for preventing potentially life-threatening complications. Ultrasonography and computed tomography (CT) scanning are two useful modalities for visualizing this abnormality. We report the case of a pa?tient whose mesenteric volvulus was di?agnosed on CT scanning and successfully treated with lysis of the adhesion and a prophylactic appendectomy.
Case report A 50-year-old white woman came to the emergency department several hours after dinner with severe right lower quadrant pain. The symptoms were much more severe before her arrival at the hospital. She reported no recent changes in her bowel movements, no nausea or vomiting, and she had passed flatus. On physical examination her abdomen was not distended, bowel sounds were present, and the abdomen was soft. Tenderness was elicited in the right lower quadrant without rebound or guarding on palpation. She had no fever and her laboratory re?sults were normal. Her medical history was significant for bilateral breast im?plants and a total abdominal hysterectomy due to painful fibroids.
Radiologic studies?A CT scan of the abdomen and pelvis showed a normal appendix, but there was gastric distention with debris indicating evidence of gastroparesis. A whorled pattern of the superior mesenteric vein (SMV) around the axis of the superior mesenteric artery (SMA) was observed (Figure), consistent with a partial bowel malrotation with volvulus.
Operation?The patient elected to have an exploratory laparotomy 48 hours later. She was found to have a viable loop of small bowel in the right lower quadrant twisted around an adhesion from the pelvis. Lysis of the adhesion and a prophylactic appendectomy were performed.
Pathology?The appendix contained a carcinoid tumor and there was fibrous obliteration of the lumen. Micro?path?ology showed a tumor measuring up to 0.4 cm invading the muscularis propria up to the outer layer.
Discussion In Western countries, the annual oc?currence of small bowel volvulus ranges from 1.7 to 5.7 in 100,000 of the population compared with 24 to 60 in 100,000 of the population in Asia or Africa.1 Rotational gut abnormalities are generally found in pediatric populations, but may be encountered in symptomatic adults with serious outcomes. Although symptomatic bowel malrotation in adults is rare, midgut volvulus is the most common complication of malrotation in adults.2
Several etiologic factors have been proposed. An increased incidence of the disorder has been described among Muslims in Afghanistan during the Ramadan festival, possibly from ingesting large quantities of fiber after fasting.3 In Turkey, small bowel volvulus constitutes 8% of all cases of mechanical in?testinal obstruction and 13% of all small bowel obstructions.4
In Western countries, volvulus of the small bowel is more common in patients with acquired predisposing factors such as malrotation, congenital bands, postoperative adhesions, Meckel's diverticulum, internal hernia, and pregnancy.5,6 The proposed mechanism of volvulus is secondary to a small bowel loop fixed at two points that twists around its mesentery.6
The most common symptom is central abdominal pain. Laboratory tests are un?reliable; however, a white blood cell count above 18,000/mm3, high lactate and amylase levels, and metabolic acidosis are present in over 50% of patients with strangulated bowel.7,8
Ultrasonography can be the first mo?dality used to check for midgut volvulus because it will show if there is reversal of the normal relationship between the SMA and SMV, which can be seen as a clockwise whirl sign. When ultrasonography findings are inconclusive, a CT scan should be next in the diagnostic workup.9 The midgut is supplied by the SMA, and when the small bowel is wrapped around this artery, it creates a distinctive whirl sign on CT scanning (Figure, panel C).5 The SMV is normally anterior and to the right of the SMA; thus, the SMV positioned to the left of the SMA can suggest bowel malrotation.2
Since small bowel volvulus is uncommon, ischemia or infarction can result from a delay in diagnosis. The cardinal presenting symptom is abdominal pain. There is no specific diagnostic clinical sign or abnormality in laboratory or radiologic findings. The diagnosis can only be confirmed by laparotomy, and failure to perform exploratory laparotomy cannot be justified. Whereas some authors document successful eneteropexies in managing this disorder, others recommend resection and primary anastomosis for all small bowel volvulus cases, with an overall mortality rate of 10% to 35% following resection.6,10 Whichever intraoperative decision is made, it has been shown that early diagnosis and early ex?ploratory laparotomy are keys to successful management.11
Conclusion Mesenteric volvulus is an uncommon but potentially life-threatening condition. Little information is available for the recommended treatment of viable bowel, and no information is available for suggested elective treatment of mesenteric volvulus. Because laboratory tests are unreliable, one must have a high index of suspicion when a patient presents with abdominal pain. Ultrasonography and CT scanning are useful modalities for diagnosing midgut volvulus. Once the diagnosis of mesenteric volvulus is made, prompt surgical intervention is required to either lyse adhesions, detorse the bo?w?el, or formally resect and anastomose the bowel if it is found to be ischemic.
References 1. Gulati SM, Grover NK, Tagore NK, et al. Volvulus of the small intestine in India. Am J Surg. 1973;126(5):661-664.
2. Shaw-Nan J, Hsein-Jar C, Yung-Fang C, et al. Midgut vol?vulus with acute abdomen in an adult patient: a case report. Chin J Radiol. 2003;23:37-41.
3. Duke JH Jr, Yar MS. Primary small bowel volvulus: cause and management. Arch Surg. 1977;112(6):685-688.
4. Gurleyik E, Gurleyik G. Small bowel volvulus: a common cause of mechanical intestinal obstruction in our region. Eur J Surg. 1998;164(1):51-55.
5. Matsuki M, Narabayashi I, Inoue Y, et al. Two adult cases of primary small bowel volvulus: usefulness of computed tomographic diagnosis. Radiat Med. 1997;15(3):181-183.
6. Iwuagwu O, Deans GT. Small bowel volvulus: a review. J R Coll Surg Edinb. 1999;44(3):150-155.
7. Bizer LS, Liebling RW, Delany HM, et al. Small bowel obstruction: the role of nonoperative treatment in simple intestinal obstruction and predictive criteria for strangulation obstruction. Surgery. 1981;89(4): 407-413.
8. Mucha P Jr. Small intestinal obstruction. Surg Clin North Am. 1987;67(3): 597-620.
9. Janssens F, Verswijvel G, Smits J, et al. Midgut volvulus in an adult patient. JBR-BTR. 2003;86(2):74-76.
10. Kreisler-Marino E, Reid ME, Gordon PH. Novel operative management of primary mesenteric volvulus. Dig Surg. 2001;18(3): 243-245.
11. Roggo A, Ottinger LW. Acute small bowel volvulus in adults. A sporadic form of strangulating intestinal obstruction. Ann Surg. 1992;216(2): 135-141.
Radiologic studies?A CT scan of the abdomen and pelvis showed a normal appendix, but there was gastric distention with debris indicating evidence of gastroparesis. A whorled pattern of the superior mesenteric vein (SMV) around the axis of the superior mesenteric artery (SMA) was observed (Figure), consistent with a partial bowel malrotation with volvulus. 
