Acute complete duodenal obstruction caused by superior mesenteric artery syndrome in an adolescent: a case report

Abstract

Introduction and importance:

Superior mesenteric artery (SMA) syndrome is a rare cause of proximal intestinal obstruction, typically associated with significant weight loss. Acute complete duodenal obstruction is an uncommon and severe presentation, particularly in adolescents.

Case presentation:

A 15-year-old severely underweight male presented with acute bilious vomiting and abdominal distension following months of early satiety and weight loss. Imaging demonstrated gastric and proximal duodenal dilatation. Computed tomography confirmed compression of the third portion of the duodenum with a reduced aortomesenteric angle. Despite 5 days of optimized conservative management, the patient showed no clinical improvement.

Clinical discussion:

Laparoscopic duodenojejunostomy was performed. The postoperative course was uneventful, with complete resolution of symptoms, restoration of oral intake, and significant weight gain.

Conclusion:

This case highlights a rare, severe presentation of SMA syndrome and underscores the importance of early recognition and timely surgical intervention when conservative management fails.

Introduction

Superior mesenteric artery (SMA) syndrome is a rare cause of proximal intestinal obstruction due to compression of the third part of the duodenum between the aorta and the SMA, often associated with significant weight loss^[1–4^]. Acute complete obstruction is an uncommon and severe presentation, particularly in adolescents^[5–7^].

We report a case of acute complete duodenal obstruction due to SMA syndrome in an adolescent, requiring surgical intervention after failed conservative management. This case report has been presented in line with the SCARE 2025 criteria^[8^].

Case presentation

A 15-year-old Saudi male presented to the emergency department with an acute onset of persistent bilious vomiting, progressive upper abdominal distension, and an inability to tolerate oral intake for 2 days. These symptoms were preceded by several months of early satiety, postprandial abdominal discomfort, and significant unintentional weight loss. The patient reported partial symptom relief when assuming a knee–chest position and worsening discomfort in the supine position. He had no prior medical or surgical history and was not taking any medications. There were no known drug allergies. Family and social history were unremarkable, and there was no history suggestive of eating disorders or psychological stressors.

HIGHLIGHTS

• Acute complete obstruction is a rare presentation of superior mesenteric artery syndrome.

• Severe weight loss significantly reduces the aortomesenteric angle.

• Conservative management may fail in complete obstruction.

• Early laparoscopic duodenojejunostomy ensures rapid recovery.

• Timely surgical intervention prevents serious complications.

On examination, the patient appeared cachectic, with a height of 155 cm and a weight of 32 kg (body mass index 13.3 kg/m²). Vital signs were stable. Abdominal examination revealed marked upper abdominal distension with mild tenderness and no peritoneal signs. A positive succussion splash (indicating gastric retention) was noted.

Laboratory tests showed leukocytosis and elevated lactate levels.

Imaging demonstrated gastric and proximal duodenal dilatation. Contrast-enhanced computed tomography (CT) confirmed compression of the third portion of the duodenum between the SMA and aorta, with a reduced aortomesenteric angle (~14°) (Fig. 1A,B).

Figure 1.

(A) Contrast-enhanced CT scan demonstrating marked gastric dilatation extending into the upper pelvis (arrow). (B) Contrast-enhanced CT scan demonstrating compression of the third portion of the duodenum between the superior mesenteric artery (SMA) and the aorta (arrows), with a reduced aortomesenteric angle measuring approximately 14°.

A nasogastric tube was inserted, draining approximately 6 L of bilious gastric content. The patient was managed conservatively with gastric decompression, intravenous fluids, electrolyte correction, and nutritional support. Upper gastrointestinal endoscopy revealed a markedly dilated stomach with bile stasis and ischemic mucosal changes, along with evidence of extrinsic compression at the junction of the second and third portions of the duodenum.

Despite 5 days of optimized conservative therapy, the patient showed no clinical improvement, with persistent vomiting and abdominal distension, indicating failure of non-operative management.

Given the severity of obstruction and failure of conservative management, surgical intervention was undertaken. Laparoscopic duodenojejunostomy was performed under general anesthesia with the patient in the supine position (Fig. 2). Prophylactic antibiotics and venous thromboembolism prophylaxis were administered preoperatively. A side-to-side anastomosis was created using a linear stapler (Endo GIA, Medtronic), and the enterotomy was closed with absorbable sutures. No intraoperative complications occurred, and the postoperative course was uneventful, with no complications (Clavien–Dindo Grade I).

Figure 2.

Intraoperative image demonstrating the creation of a side-to-side laparoscopic duodenojejunostomy.

Discussion

A contrast study on postoperative day 3 demonstrated free passage without obstruction. Oral intake was gradually resumed, and the patient was discharged on postoperative day 9 in stable condition.

At 3-month follow-up, the patient reported complete resolution of symptoms, with weight gain from 32 to 38 kg and improved nutritional status. Follow-up imaging confirmed sustained decompression of the stomach and duodenum without recurrence.

SMA syndrome results from compression of the third portion of the duodenum between the aorta and SMA, typically due to the loss of the mesenteric fat pad following weight loss^[1–4^]. Most cases present with partial obstruction, whereas acute complete obstruction is rare, particularly in adolescents^[5–7^].

Clinical presentation is often nonspecific, leading to delayed diagnosis. Progressive weight loss and reduced oral intake may exacerbate vascular compression, creating a vicious cycle that can culminate in complete obstruction.

A broad differential diagnosis should be considered, including intrinsic causes such as duodenal web and annular pancreas, and extrinsic causes such as malrotation, as well as functional disorders like gastroparesis^[4,5,9^].

CT remains the diagnostic modality of choice, allowing visualization of duodenal compression and measurement of the aortomesenteric angle^[4,5,9^]. Severe cases may demonstrate marked gastric dilatation with risk of ischemia or perforation^[6,7,10,11^].

Initial management is conservative, focusing on gastric decompression, fluid resuscitation, nutritional support, and correction of metabolic abnormalities. However, failure is common in advanced cases, necessitating surgical intervention.

Several surgical options have been described, including Strong’s procedure and gastrojejunostomy; however, laparoscopic duodenojejunostomy is the preferred definitive treatment due to its high success rate and durable symptom relief^[1–3,12,13^].

Unlike most reported cases that present with partial obstruction and respond to conservative therapy, this case demonstrates acute, complete duodenal obstruction with massive gastric dilatation requiring surgical intervention in an adolescent – a presentation that is rarely reported.

This case highlights the importance of early recognition and timely escalation of management. Reports from the Middle East remain limited.

Strengths and limitations

This case demonstrates clear radiological findings and successful minimally invasive management. Limitations include the single-case design and a relatively short follow-up.

Conclusion

SMA syndrome is a rare cause of proximal intestinal obstruction. Acute complete obstruction is a severe presentation that may require early surgical intervention when conservative management fails. Laparoscopic duodenojejunostomy is a safe and effective definitive treatment.

Ethical approval

Ethical approval was not required for this single case report in accordance with institutional policy.

Consent

Written informed consent was obtained from the patient and the patient’s legal guardian for publication of this case report and accompanying images.

Sources of funding

No funding was received for this study.

Author contributions

S.S.S. Alqahtani: Conceptualization, data collection, literature review, manuscript drafting. H.H.: Consultant supervision, critical revision. M.A.A.: Clinical management, manuscript editing. Y.M.A.: Surgical contribution, manuscript review.

Conflicts of interest disclosure

The authors declare no conflicts of interest.

Research registration unique identifying number (UIN)

Not applicable.

Guarantor

Sarah S.S. Alqahtani.

Data availability statement

All relevant data supporting the findings of this case report are included within the article. No additional datasets were generated or analyzed.

Artificial intelligence statement

No artificial intelligence tools were used in the preparation of this manuscript.