Superior mesenteric artery syndrome in a 30-year-old male patient: A case report and literature review

Abstract

Introduction and importance

Due to a decrease in the aortomesenteric angle, the third section of the duodenum can become acutely or chronically compressed in the superior mesenteric artery syndrome (SMAS).

Case presentation

A 31-year-old male patient complained of one-year-long recurrent postprandial abdominal pain, periumbilical, intermittent, and colicky. The pain increased in severity in the last 4 months and was relieved only with self-induced vomiting and partially with the knee-to-chest position. A CT scan was done and is most consistent with superior mesenteric artery syndrome. The patient was admitted to the operating room and underwent a successful laparoscopic duodenectomy of the third part of duodenum followed by duodenojejunostomy.

Clinical discussion

When conservative therapy fails, an open duodenojejunostomy is traditionally advised. A less invasive option that has been documented in up to 10 cases is laparoscopic duodenojejunostomy. We discuss the research on this issue and demonstrate our surgical method on one patient.

Conclusion

Even if there has been just a modest amount of weight loss, SMAS should be taken into account whenever a sudden observation of gastrointestinal obstruction symptoms is noted in patients with susceptible conditions such as low body weight.

Highlights

• •The third portion of the duodenum is externally compressed between the aorta and the SMA, which results in the rare and symptomatic condition known as superior mesenteric artery syndrome (SMAS)
• •Due to its rarity, vague clinical manifestations, and low indexes of suspicion, SMAS is difficult to diagnose
• •If conservative measures fail, surgical options, such as laparoscopic duodenojejunostomy, may be considered.

1. Introduction

The third portion of the duodenum is externally compressed between the aorta and the SMA, which results in the rare and symptomatic condition known as superior mesenteric artery syndrome (SMAS) [1]. SMAS is a rare cause of small bowel obstruction. According to the literature, the incidence of superior mesenteric artery syndrome ranges from 0.1 to 0.3 % [2]. Females and adolescents (18–35 years) have a higher likelihood to be affected, nevertheless it can affect anyone at any age. This gender and age distribution may simply indicate the condition's predisposing cause, particularly eating disorders [3]. Due to its rarity, vague clinical manifestations, and low indexes of suspicion, SMAS is difficult to diagnose. The third segment of the duodenum's external compression is frequently mistakenly detected during the investigative phase of exclusion, which makes diagnostic delay typical [3]^, [4].

It is worth noting that the main contributory pathophysiologic mechanism in SMA syndrome is the severe catabolic condition leading to loss of the fat pad between the SMA and the aorta as a result of thin lean body habitus and loss of weight. Other conditions, such as chronic illness, sepsis, cancers, traumatic events, eating disorders, substance abuse, spinal or bariatric surgeries, may all culminate in diminished intraabdominal fat mass, resulting in SMA syndrome [5]^, [6]. SMAS also has been reported after abdominal aortic aneurysm repair and proctocolectomy with ileal pouch-anal anastomosis (IPAA) [7].

Many patients experience upper gastrointestinal (UGI) disturbances and related comorbidities such as food intolerance, undernutrition, weight loss, electrolyte imbalance, and poor quality of life as a result of delayed diagnosis and subsequent inefficient therapy [3]. To prevent these issues and implement appropriate treatment for recovery, early diagnosis is crucial when there are reasonable grounds for suspicion. Radiological testing can confirm SMAS. The hypotonic duodenography, or UGI series, continues to be the standard for diagnosis. The angle and distance between the aorta and the SMA are shown by contrast enhanced computed tomography (CECT), magnetic resonance angiography (MRA), or ultrasonography [4]. This case report has been reported in line with the SCARE Criteria [8].

2. Presentation of case

A 31-year-old male patient was transferred from the private sector to our government surgical outpatient clinic due to chronic postprandial abdominal pain and recurrent vomiting. The above-mentioned patient, who has free medical and surgical histories, reports a one-year history of recurrent postprandial abdominal pain, periumbilical, intermittent, and colicky. The pain increased in severity in the last 4 months and was relieved only with self-induced vomiting and partially with the knee-to-chest position. The pain was associated with anorexia, nausea, and a weight loss of five kilograms in the last two months. Except for his slim build, his physical examination was unremarkable. His height was 182 cm, and he weighed 60 kg with a body mass index of 18.1. His abdomen was soft and lax, with mild periumbilical tenderness and negative peritoneal signs. His blood results showed a serum potassium of 3.7 mmol/L, sodium of 135 mmol/L, albumin of 5.3 g/L, creatinine of 0.94 μmol/L, white cell count of K/μL, and hemoglobin of 16.1 g/L.

A computed tomography (CT) scan of his abdomen (Fig. 1, Fig. 2) showed a mild wall thickening of the descending and sigmoid colon, left mid-abdomen ileo-ileal intussusception, a dilated second part of the duodenum, L5-S1 level left side spondylolysis, and mildly enlarged liver and spleen, with contrast reaching to the large bowel loops. The aortomesenteric angle was reduced to 8° and the distance to 4 mm. Barium meal showed a tortuous, elongated second portion of the duodenum, consistent with mild superior mesenteric artery syndrome (Fig. 3). These radiological features are most consistent with superior mesenteric artery syndrome. Upper GI endoscopy showed a wide cardia with a small hiatal hernia and mild gastritis; deep intubation of the postbulbar duodenum showed no lesions or stenosis.

Fig. 1.

An enhanced abdominal CT scan demonstrating moderate dilatation of the stomach and proximal duodenum, as well as tapered narrowing of the third segment of the duodenum as it passes between the superior mesenteric artery and the aorta (arrows). There is a relative lack of fat surrounding the superior mesenteric artery. (S: stomach, D: duodenum, SMA: superior mesenteric artery, A: aorta, LRV: left renal vein.)

Fig. 2.

There is an abnormal reduction of the aortomesenteric distance (measured up to 4 mm at both the sagittal (A) and axial (B) planes) as well as the aortomesenteric angle (measured at 8° at the sagittal view of the abdominal aorta (C)). The left renal vein is also compressed between the superior mesenteric artery and the aorta (D). (D: duodenum, SMA: superior mesenteric artery, A: aorta, LRV: left renal vein.)

Fig. 3.

Barium meal showed a tortuous, elongated second portion of the duodenum (arrow), consistent with mild superior mesenteric artery syndrome.

The patient was started on conservative management with a trial of weight gain by oral diet. Eventually, the decision was made to undergo surgery. The patient was admitted to the operating room and underwent a laparoscopic duodenectomy of the third part of duodenum followed by duodenojejunostomy.

3. Operative and post-operative courses

Under general anesthesia the patient placed in supine position. Scrubbing and draping infraumbilical incision pneumoperitoneum and 3 other trocars were inserted. Identification of superior mesenteric artery (SMA) compressing the third part of the duodenum. Dissection of third part of duodenum, inferior vena cava (IVC), and pancreases. Division of ligament of Treitz with dissection of duodenojejunal junction of aorta, IVC, and SMA and extracted from SMA aorta window then excision of the third and fourth parts of duodenum and retrieved through 10 mm port. Two enterotomies were performed on distal duodenum and proximal jejunum and side-side duodenojejunal anastomosis was done with endostapler (Fig. 4). Enterotomy was closed by running 2-0 Vicryl sutures and the hemostasis was secured. Closure of mesentery window and a drain was inserted at the site of anastomosis. Umbilical wound was closed under vision followed by wound closure.

Fig. 4.

Intraoperative images. (SMA: superior mesenteric artery, IVC: inferior mesenteric artery.)

The procedure was performed by a consultant at general surgery department. Following the procedure, the gastrointestinal complaints of patient including post-prandial pain have been subsidized. The patient was followed-up for 3 months with regular weekly visits that revealed a significant improvement in his clinical status without any reported complications, adverse events, or re-admissions.

4. Discussion

Rokitansky initially reported the superior mesenteric artery syndrome (SMAS) in 1861, commonly referred to as Wilkie's syndrome. SMAS is a fairly uncommon cause of proximal small-bowel obstruction [9]^, [10]. The English literature has described about 400 cases, with a small female preponderance [5]. The diagnosis of this uncommon and contentious illness has become significantly simpler because of the availability of dynamic CT scans. The third portion of the duodenum crosses through the aortomesenteric vascular angle, which is where the SMA typically exits the aorta at a 45-degree angle. Extrinsic duodenal compression is typically avoided by a mass of fat and lymphatic tissue around the SMA. SMAS can be caused by any condition that reduces the aortomesenteric angle to between 6 and 16° [10].

The duodenum develops from both the foregut and the midgut. The foregut gives rise to the proximal portion of the duodenum up to the opening of the bile duct, while the midgut gives rise to the remainder of the section. The duodenum is supplied by branches of both the celiac artery and the SMA due to its dual origin. For as long as the organ remains in the umbilicus, the embryonic SMA extends beyond the intestine and into the yolk sac. This artery is the supply artery for a persistent Meckel's diverticulum. During the fifth intrauterine week, the herniated midgut loop rotates 90° counterclockwise, bringing the future duodenum to the left of the embryonic SMA. The small intestine returns to the abdomen during the 10th week, followed by the colon, so that the duodenum lies to the left beneath the SMA [11]^, [12].

The clinical manifestations of SMAS occur secondary to the duodenal obstruction in which the patient may present with early satiety and/loss of appetite, epigastric pain, potentially severe post-prandial pain/fullness, nausea and vomiting that may be bilious, eructation, reflux, and ‘food fear’ leading to malnutrition, weight loss, and poor weight gain. However, unusual presentation such ovarian vein obstruction with resultant ovarian varix has been reported [13].

This syndrome, which is frequently identified during the course of an investigation to rule out other possible illnesses, is still unknown to many clinicians [4]. By presenting radiographic evidence of external compression of the third section of the duodenum, SMAS is diagnosed. With the exclusion of other diagnoses, every patient who fulfilled imaging criteria of decreased aortomesenteric angle, diminished aortomesenteric distance, and proximal duodenal dilatation, especially in cases where no water or contrast was administered orally prior to the CT examination, scored 3/3, were identified to have SMA syndromes [14]. UGI series, hypotonic duodenography, CT, or MRA can all be used to show these. The majority of studies in the literature employed UGI or CT to diagnose SMAS.

The compatible findings of UGI series or hypotonic duodenography, which is a mainstay in diagnosing SMAS, include an abrupt vertical or oblique cutoff of contrast just right of midline at the third part of the duodenum, with dilation of the first and second parts of the duodenum, delayed gastric and duodenal emptying, and a to and fro pattern of antiperistaltic waves proximal to the third part [1]^, [4]. In addition, patients with true vascular compression of the duodenum often show an increase in the passage of contrast to the distal duodenum by repositioning into a left lateral or prone position [4]. Some of the patients undergo endoscopy as they might have been referred to a gastroenterologist in view of the abdominal symptoms.

An abrupt vertical or oblique cutoff of contrast just right of midline at the third part of the duodenum, dilation of the first and second parts of the duodenum, delayed gastric and duodenal emptying, and a to and fro pattern of antiperistaltic waves close to the third part are all compatible findings of the UGI series or hypotonic duodenography, which is a mainstay in diagnosing SMAS [1]^, [4]. The passage of contrast to the distal duodenum is also frequently increased in individuals with genuine vascular compression of the duodenum by placing them in a left lateral or prone posture [4]. Due to their possible referral to a gastroenterologist due to their abdominal problems, some of the patients undergo endoscopy. On endoscopy, case reports do mention characteristics of duodenal dilatation along with significant volumes of stomach contents as being diagnostic of SMA syndrome [15]. Endoscopic ultrasound can be used to confirm that the obstruction has a narrowed aortomesenteric distance and is pulse-like in nature. In order to rule out further pathologies, such as duodenal tumors or peptic ulcer disease, which can also result in duodenal blockage [16], endoscopic assessment is also helpful.

To lessen obstructive symptoms, SMA syndrome is treated by restoring retroperitoneal fat. First, conservative techniques are used. To rectify electrolyte abnormalities, the patient is given fluid support [16]. Nasojejunal feeding and nursing in the left lateral or prone posture avoids the blockage. Increased retroperitoneal fat may be achieved with parenteral feeding. Prokinetics and antacids were among the drugs occasionally recommended [17]. According to reports, the average length of medical therapy is about 45 days. Since medicinal therapy that lasted longer than six weeks produced worse results, surgical surgery is an option [17].

If conservative measures fail, the following surgical options have been proposed: duodenojejunostomy with or without division of the fourth part of the duodenum (Strong's procedure); duodenojejunostomy with or without division of the fourth part of the duodenum; and gastrojejunostomy. Strong's procedure has the advantage of preserving bowel integrity, but it has a 25 % failure rate, owing to short branches of the inferior pancreaticoduodenal artery that prevent the duodenum from falling inferiorly [18]^, [19]^, [20]. Stavely [19] described duodenojejunostomy as a treatment for this condition in 1908, and it is widely accepted as having superior results to both Strong's procedure and gastroenterostomy. However, duodenojejunostomy without division of the fourth part of the duodenum carries the risk of blind loop syndrome. Recently, laparoscopic Strong procedures and laparoscopic duodenojejunostomy have been reported by several centers as advances in laparoscopic surgery. According to reports, it has the best success rate [21]^, [22].

In their study, William and his colleague showed that the average operating time of laparoscopic approach was 113 min and 3 days average of hospital stay length without any reported complications [21]. Some authors have advocated for resection of the abnormal duodenum instead of bypassing the duodenal third part in patients with SMA syndrome, claiming that it is a variant of a motility disorder rather than a true mechanical obstruction [22].

5. Conclusion

In conclusion, clinical symptomatology, physical examination, and endoscopic information are important for early suspicion of SMAS. Laparoscopic duodenojejunostomy is feasible, safe, and effective. It gives the same results as open surgery with all the advantages of minimally invasive surgery.

Patient consent

Written informed consent to publish this case and use anonymized radiologic material was obtained from the patient.

Authorship

All authors attest that they meet the current ICMJE criteria for authorship.

Ethical approval

This study is exempt from ethical approval in our institution.

Funding

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Guarantor

Oadi N. Shrateh.

Research registration number

Not applicable.

CRediT authorship contribution statement

• Writing the manuscript: Malvina Asbah, Oadi N. Shrateh, Asil Musleh, Khaled Abbadi

• Imaging description: Mohammed Nofal

• Reviewing & editing the manuscript: Sulaiman Tarifi.

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.