Laparoscopic Duodenojejunostomy for the Treatment of Superior Mesenteric Artery (SMA) Syndrome: Case Series

Introduction

Superior mesenteric artery (SMA) syndrome was described in 1861 by the Austrian physician and philosopher, Carl Freiherr von Rokitansky ¹ and, since then, has been described by many researchers as rare and difficult to diagnose. SMA syndrome has been defined as a condition in which the third portion of the duodenum is compressed between the superior mesenteric neurovascular bundle anteriorly and the vertebral column posteriorly. This compression leads to either an acute or chronic presentation of intermittent emesis and postprandial abdominal pain. Many pathophysiologic factors to the syndrome lead to a mechanical obstruction of the third portion of the duodenum. Extensive investigations usually include an upper gastrointestinal contrast study, endoscopy, abdominal ultrasound (U/S), angiography, and multislice computer tomography (CT). Conservative medical management is advocated as the first line of treatment, but surgical management is considered in cases where this has failed. Previously, open duodenojejunostomy was considered the most successful surgical intervention, but recent advances in laparoscopic techniques have made laparoscopic duodenojejunostomy a safe, efficacious option.

Case Report 1

A 41-year-old female presented with an acute history of right-upper quadrant pain. Her associated symptoms included nausea, vomiting, and fever. Her past medical history included quadriplegia secondary to a C6–C7 cervical subluxation, cervical myelopathy, rheumatoid arthritis, psoriasis, and a cholecystectomy 7 weeks previously. On admission, her liver-function tests were deranged, suggestive of cholangitis, and the patient was treated with antibiotics. A plain abdominal X-ray showed a dilated stomach and associated dilatation of the 2nd (D2) and 3rd (D3) part of the duodenum with multiple air-fluid levels. The patient was treated conservatively with nasogastric tube decompression. U/S was unremarkable. After 5 days of conservative management, a CT scan displayed dilatation of the proximal duodenum and stomach, as well as nonspecific thickening of the sigmoid and descending colon with surrounding inflammation. Due to the dilatation of the proximal duodenum to D3, where it is interposed between the SMA and the aorta, a diagnosis of SMA syndrome was made. Despite a further period of conservative management, the patient failed to improve and was taken to the operating theater for a laparoscopic duodenojejunostomy.

The abdomen was entered through the umbilicus with an optiview port, and after insufflation of the abdomen, three 5-mm ports were inserted. The omentum was dissected away from the second and third parts of the duodenum, and it was observed that the stomach and duodenum were grossly distended with an associated collapsed small bowel distal to the duodenum. The transverse colon was elevated on sutures and a window was made lateral to the middle colic vessels to expose the duodenum. The duodenum was mobilized; the jejunum was approximated to the second part of the duodenum in a retrocolic fashion. A stay suture, incorporating the duodenum and the jejunum, was placed and enterotomies were made in both loops of bowel. A 45-mm staple gun was inserted, and a single fire was performed. Suture lines were hemostatic and intact, and the enterotomy was closed with a further staple line. There was no narrowing of the jejunal loop, which was left sitting in a satisfactory position. Operative time was 1 hour and 35 minutes. The patient recovered uneventfully and was discharged home on postoperative day 5. During the acute period prior to surgery, she lost 4 kg in weight, but this returned to 51 kg in 2 months postoperatively On follow-up, the patient has remained symptom-free 2.5 years postsurgery.

Case Report 2

A 28-year-old man was referred with a 10-year history of recurrent episodes of subumbilical pain, sweating, fullness, vomiting up to two meals at a time, weight loss of over 12 kg over 10 years, and explosive diarrhea. The episodes were becoming more frequent over the preceding 6 months. He had previously had multiple barium meal investigations that were inconclusive. Past medical history included a previous cholecystectomy. A CT scan with intravenous (i.v.) and oral contrast showed narrowing of the SMA/aortic angle to approximately 20 degrees. This was associated with a partial compression of the third part of the duodenum by the SMA. While no dilatation of the proximal duodenum was seen, the narrowing of the angle was in keeping with the suspected diagnosis of SMA syndrome. The patient underwent a laparoscopic duodenojejunostomy. The procedure was performed in the same fashion as described in the first patient. The operative time was 3.5 hours. The patient's recovery was uneventful, and he discharged himself 4 days postsurgery. On follow-up 5 years later, his symptoms have not recurred, and his weight had increased from 61 preoperatively to 75 kg.

Case Report 3

A 36-year-old man presented with a 13-year history of severe daily periumbilical abdominal pain, bloating, and flatulence, with occasional episodes of vomiting if the pain was prolonged. He had progressive weight loss because of poor intake due to postprandial pain and was 50 kg prior to surgery. He also complained of bowel changes between constipation and diarrhea. He had no medical history of note. Previous investigations under the care of his primary physicians included a hepatobiliary imino-diacetic acid scan, Meckel's scan, multiple gastroscopies, which included a bowel flush-out, and the introduction of new bowel flora for recolonization therapy. He was also treated with flagyl/salazopyrin and colchicine, which seemed to assist in managing the pain for a short period of time. He also underwent a negative diagnostic laparotomy. Due to persistent presentations, the patient underwent an abdominal CT scan that showed marked dilatation of the 2nd and 3rd parts of the duodenum and a tapering of contrast between the SMA and the aorta. The aorto-SMA angle was measured at approximately 17 degrees.

A diagnosis of SMA syndrome was made, and he was referred to our unit for consideration of laparoscopic duodenojejunostomy. At surgery, adhesions from the previous laparotomy were taken down, and findings included a grossly dilated 2nd and 3rd part of the duodenum and a completely collapsed 4th part of the duodenum with constrictions from the superior mesenteric vessels. The very short loop of upper jejunum was brought across the duodenum in the third part, and a stapled side-to-side anastomosis was performed. The remaining enterotomy was closed with 3/0 prolene. The procedure time was 2 hours. The patient was discharged on day 4. Since his operation 7 years ago, the patient has gained significant weight to approximately 62 kg. His symptoms, although not completely resolved, are significantly less severe. His persistent symptoms include bloating and flatulence, as well as alternating bowel habit, and are thought to be irritable bowl syndrome. However, his pain has resolved. On follow-up gastroscopies, he has had a widely patent duodenojejunostomy.

Discussion

SMA syndrome is defined as a compression of the third part of the duodenum between the superior mesenteric neurovascular bundle anteriorly and the aorta or vertebral column posteriorly. Compression of the duodenum is thought to occur due to loss of fat around the superior mesenteric neurovascular pedicle. SMA syndrome was first described in 1861 by von Rokitansky, ¹ followed not long after by Willet, who described, in 1878, a 17-year-old male with similar symptoms after being placed into a body cast and hence coined the term “cast syndrome.” ² In 1927, Wilkie also changed the terminology to follow his surname after collating the largest series of patients with a chronic duodenal ileus. ³ The term has changed over the years, with Cimmino in 1961 describing it as an angioneuromesenteric occlusion of the duodenum, ⁴ and in the 1970s, it was described as a vascular compression of the duodenum. ⁵

Although the term SMA syndrome has changed over the years, the symptomatology has remained similar. This includes the description of postprandial pain, fullness, voluminous vomiting, with early satiety, nausea, and weight loss.^5–10 The presentation may be of an acute nature within hours or a chronic condition, which culminates in progressive symptoms and severity.^7,8,11,12 The patients are described as having some relief of their symptoms when they place their knees to their chest or when lying in the prone position postprandially. ⁶ There has been a reported association of 25–45% and 50% with peptic ulcer disease and hyperchlorhydria, respectively. ⁸

There are many thoughts as to the mechanism and cause of SMA syndrome. It is believed that a decrease in the aortomesenteric angle is one of the main contributing factors.^{4,5,7,13–16} The SMA usually forms an angle of approximately 45 degrees (range, 38–56) with the abdominal aorta, and the 3rd part of the duodenum crosses caudal to the origin of the SMA, coursing between the SMA and aorta. Any factor that sharply narrows the aortomesenteric angle to approximately 6–25 degrees can cause entrapment and compression of the third part of the duodenum as it passes between the SMA and aorta, resulting in SMA syndrome. In addition, the aortomesenteric distance in SMA syndrome is decreased to 2–8 mm (normal is 10–20 mm).

This occurs either by reduction in the mesenteric fat, by chronic immobilization in the supine position, which can occur in trauma or burns patients,^7,17 or dietary disorders, such as anorexia nervosa or malabsorptive conditions.^1,10,18–20 Another factor considered to be involved is a thickening of the root of the mesentery itself. This may be due to the inflammatory pathology of a nearby structure, which affects the surrounding mesentery, such as episodes of acute pancreatitis, acute enterocolitis, bowel infarction, or cholecystitis.^8,11,14 Processes that limit the space of the vascular angle, such as tumors, lymph nodes, or abdominal aneurysms, can also result in the syndrome.^5,7,11,14 Diseases of the duodenum subsequently leading to thickening may also be involved, such as peptic ulcer disease and Crohn's disease.^10,14 Last, decreased intestinal motility, leading to atonia and dilatation of the lumen of the viscera, can be associated with SMA syndrome. ¹⁴

As the diagnosis is essentially one of exclusion, frequently patients undergo multiple tests before a diagnosis is finally made.^16,21–23 This is due to the variety of patient presentation, the rarity of the syndrome, and the fact that conventional investigations can commonly be negative. Confirmation usually requires a combination of radiologic and endoscopic investigations. A plain X-ray may indicate gastric dilatation.^11,14,16 A majority of patients will receive an endoscopy to rule out a mechanical cause. A positive barium study will show duodenal dilatation with retention of barium within the duodenum. It will also show characteristic vertical linear extrinsic pressure in the 3rd portion of the duodenum.^{11,14,16,22,24} Hypertonic duodenography is also used to display the location of an obstruction with a dilated proximal duodenum and antiperistaltic waves in the dilated portion of the duodenum.^14,16,18,21 This can provide sufficient evidence for the diagnosis. Ultrasound or arteriography are used to visualize the angle of the SMA and the aortomesenteric distance.^14,22 In agreement with other studies, we have found that CT provides information not only on the affected portion of the duodenum, but also assists in the measurement SMA-aortic mesenteric angle (Fig. 1).^14,16,22

OPEN IN VIEWER

FIG. 1.

Contrast computed tomography scan demonstrating dilated duodenum with transition point at level of superior mesenteric artery (circled).

Treatment usually begins with a conservative medical approach.^1,11,25–27 Symptoms can resolve with i.v. fluid replacement, nasojejunal feeding in order to bypass the area of narrowing, small liquid meals, prokinetic agents, or positioning the patient in a knee to chest position or prone after eating. ⁸ Surgical treatment of SMA syndrome is indicated when either conservative management fails or the condition is chronic. ¹¹ In 1908, Stavely performed the first open duodenojejunostomy, ²⁸ after which many of the surgical procedures were performed open, either proceeding to a gastrojejunostomy, duodenojejunostomy, or a ligation of the ligament of Treitz with the associated repositioning of the duodenum.^15,25 This surgery produced good results for the patient's symptoms. Studies have showed that the most successful surgical procedure was a duodenojejunostomy.^26,27 Presently, laparoscopic management of SMA syndrome is becoming a more popular alternative to open procedures.^{10,12,15,25–27} We have identified 6 case reports of laparoscopic surgical intervention of SMA syndrome. In 1995, Massoud described 4 patients that were treated via ligation of the ligament of Treitz and reported a 75% success rate. ¹⁵ Gersin and Heniford were the first to describe the laparoscopic technique of duodenojejunostomy in 1998. ¹² Other reports from Richardson and Surowiec, ¹⁰ Bermas and Fenoglio, ²⁵ Kim et al., ²⁹ and Kingham et al. ³⁰ have indicated that laparoscopic management is a safe alternative and that the procedure time is reduced, the operative field is adequately accessed and visualized, and recovery time is also reduced. As seen in our case series, all 3 patients were treated conservatively in the first instance, but due to persistent symptoms, underwent laparoscopic surgery. All 3 cases had minimal operating times, an uneventful recovery, and were discharged shortly after surgery. Two of the 3 patients had complete symptomatic relief and the third had a significant improvement.

Conclusion

We believe that laparoscopic duodenojejunostomy is the most appropriate form of surgical management in patients who have failed conservative medical management of their SMA syndrome.