```html

Wilkie’s Syndrome (Superior Mesenteric Artery Syndrome)

Overview

Wilkie’s syndrome, also known as **superior mesenteric artery (SMA) syndrome** or aortomesenteric duodenal compression, is a rare vascular compression disorder in which the third portion of the duodenum is squeezed between the aorta and the superior mesenteric artery. This narrowing obstructs the passage of food, leading to a spectrum of gastrointestinal symptoms.

Who it affects: It can occur in anyone but is most common in thin adolescents, young adults, and individuals who have experienced rapid weight loss (e.g., after bariatric surgery, eating disorders, or severe illness). Women are slightly more frequently reported than men (≈ 55 % vs. 45 %).

Prevalence: Reported prevalence varies from 0.013 % to 0.3 % of the general population, with higher rates (up to 1 %) among patients with severe cachexia or postoperative weight loss. Because the condition is under‑diagnosed, exact numbers are uncertain.<sup>1</sup>

Symptoms

Symptoms are often vague early on and may be misattributed to other GI disorders. They typically worsen after meals and improve when lying in the left lateral decubitus or knee‑chest position (which widens the aortomesenteric angle).

• Post‑prandial epigastric pain – cramping or burning that begins 15–30 minutes after eating.
• Early satiety – feeling full after only a few bites.
• Nausea and vomiting – may be bilious if the obstruction is distal enough.
• Weight loss – both a cause and a consequence; often >10 % of body weight.
• Abdominal bloating & distension – due to trapped gas and fluid.
• Reflux‑type symptoms – heartburn or sour taste from duodenal contents.
• Mid‑back pain – referred pain from the retroperitoneal location.
• Palpitations or light‑headedness – secondary to dehydration and electrolyte loss.

Because the presentation mimics peptic ulcer disease, functional dyspepsia, or chronic pancreatitis, a high index of suspicion is essential.

Causes and Risk Factors

Pathophysiology

The SMA normally arises from the abdominal aorta at a 45°–60° angle, leaving a 10–28 mm space (the aortomesenteric distance) for the duodenum to pass. When the mesenteric fat pad diminishes—often after rapid weight loss—the angle narrows to < 25° and the distance can shrink to < 8 mm, compressing the duodenum.<sup>2</sup>

Key Risk Factors

• Severe or rapid weight loss (≥ 15 % body weight in < 6 months) due to
  • Eating disorders (anorexia nervosa)
  • Malignancy‑related cachexia
  • Post‑bariatric surgery
  • Chronic infections (TB, HIV)
• Congenital or acquired high‑grade lumbar lordosis (e.g., scoliosis, hyperlordotic posture).
• Spinal surgery or instrumentation that shortens the aortomesenteric distance (e.g., lumbar fusion, corrective scoliosis surgery).
• Trauma or intra‑abdominal masses that push the SMA forward.
• Female gender – possibly related to lower average body fat distribution.

Diagnosis

Diagnosing Wilkie’s syndrome requires correlating clinical suspicion with imaging that demonstrates duodenal compression and a reduced aortomesenteric angle/distance.

Imaging Studies

• Computed Tomography Angiography (CTA) – Gold standard. Shows a narrowed angle (< 25°) and distance (< 8 mm) plus dilated proximal duodenum.
• Magnetic Resonance Angiography (MRA) – Useful when radiation avoidance is essential (e.g., in young patients).
• Upper Gastrointestinal (UGI) series – Barium study reveals delayed passage through the third part of the duodenum with a “horseshoe‑shaped” obstruction.
• Endoscopic Ultrasound (EUS) – Can assess the mesenteric fat pad and exclude intraluminal lesions.

Other Evaluations

• Basic labs (CBC, electrolytes) to detect dehydration, anemia, or electrolyte disturbances.
• Upper endoscopy (EGD) – Primarily to rule out peptic ulcer disease, gastritis, or malignancy; may show retained food in the duodenum.
• Positional symptom testing – Repeating imaging or symptoms after lying prone/knee‑chest can demonstrate improvement, supporting the diagnosis.

Treatment Options

Treatment is individualized and starts with the least invasive measures.

Conservative (Non‑surgical) Management

• Nutritional rehabilitation – The cornerstone. Aim for 10–15 % increase in body weight over 6–12 weeks using high‑calorie oral supplements, small frequent meals, and possibly a dietitian‑guided plan.
• Postural therapy – Encourage the left lateral decubitus or knee‑chest position during and after meals to increase the aortomesenteric angle.
• Enteral feeding – If oral intake fails, place a naso‑jejunal tube or a percutaneous endoscopic jejunostomy (PEJ) to bypass the obstruction and promote weight gain.
• Prokinetic agents (e.g., metoclopramide, erythromycin) may improve gastric emptying but do not address the mechanical compression.

Surgical Interventions

Considered when > 4–6 weeks of conservative therapy fail, or when patients present with severe malnutrition, recurrent vomiting, or complications.

• Duodenojejunostomy (most common) – Creates a side‑to‑side anastomosis between the duodenum (usually D2) and jejunum, bypassing the compressed segment. Reported success rates 80–90 % with low morbidity.<sup>3</sup>
• Lesser‑curvature gastrojejunostomy – Less frequently used; connects the stomach to the jejunum.
• Strong’s procedure (division of the ligament of Treitz) – Mobilizes the duodenum downward, relieving tension. Success is variable; often combined with duodenojejunostomy.
• Laparoscopic vs. open approach – Laparoscopic surgery offers shorter hospital stay, less postoperative pain, and quicker return to oral intake.

Medications for Symptom Relief

• Antiemetics (ondansetron, promethazine) for acute nausea.
• PPI or H2‑blocker if concomitant reflux or gastritis is present.
• Analgesics – Use cautiously; opioids can worsen constipation and nausea.

Living with Wilkie’s Syndrome

Dietary Strategies

• Eat small, frequent meals (5–6 times/day) rather than large meals.
• Choose high‑calorie, nutrient‑dense foods – smoothies, nut butters, avocados, full‑fat dairy.
• Limit high‑fiber or bulky foods that may increase duodenal filling (e.g., raw vegetables, bulk‑forming cereals).
• Stay upright for at least 30 minutes after eating; then adopt a left‑lateral or knee‑chest position for an additional 15–20 min.

Hydration & Electrolytes

Drink 2–3 L of fluid daily, preferably between meals. If vomiting is frequent, consider oral rehydration solutions or electrolyte‑containing drinks.

Physical Activity

Light to moderate activity (walking, yoga) promotes appetite and abdominal muscle tone. Avoid activities that increase intra‑abdominal pressure (heavy lifting) until weight stabilizes.

Follow‑up Care

• Weight and nutritional status should be checked every 2–4 weeks initially.
• Repeat imaging (CTA or MRA) after 3–6 months of weight gain to confirm angle restoration.
• Post‑surgical patients need routine wound checks and nutritional counseling; most regain normal eating patterns within 6 weeks.

Prevention

Because the syndrome frequently follows rapid weight loss, primary prevention focuses on maintaining adequate nutritional reserves.

• In patients undergoing bariatric surgery or chronic illness, schedule early dietitian visits and monitor weight trajectories.
• For eating‑disorder patients, multidisciplinary treatment (psychology, nutrition, medical supervision) is key.
• Post‑spinal surgery patients should have a post‑operative plan that includes gradual weight restoration and, when appropriate, prophylactic positioning measures.
• Encourage a balanced diet with healthy fats, which preserve mesenteric fat padding.

Complications

If left untreated, the chronic obstruction can lead to serious sequelae:

• Severe malnutrition and cachexia – profound weight loss, muscle wasting, immune suppression.
• Electrolyte disturbances – hypokalemia, metabolic alkalosis from persistent vomiting.
• Peptic ulcer disease – due to stasis and increased gastric acidity.
• Pancreatitis – secondary to reflux of duodenal contents into the pancreatic duct.
• Superior mesenteric artery thrombosis – rare but reported when turbulent flow persists.
• Psychological impact – anxiety, depression related to chronic GI symptoms and weight loss.

When to Seek Emergency Care

---

References:
1. G. Ghosh et al., “Superior mesenteric artery syndrome: a review of the literature,” Journal of Gastrointestinal Surgery, 2020.
2. A. N. Gaur et al., “Anatomical considerations in SMA syndrome,” Radiographics, 2019.
3. J. L. Lee et al., “Outcomes of laparoscopic duodenojejunostomy for SMA syndrome,” Cleveland Clinic Journal of Medicine, 2021.
Additional data from Mayo Clinic, NIH National Library of Medicine, and WHO guidelines (accessed May 2026).

```