Superior mesenteric artery syndrome: Diagnosis and management

Table 1 Incidence of superior mesenteric artery syndrome in several populations

Population	Incidence (%)	Ref.
Acute general hospitals	0.001-0.0052	[18]
Chronic-care hospital	0.097	[18]
Hospital admissions	0.05-2.67	[12,27,28]
Upper gastrointestinal endoscopy	0.48	[29]
Post-scoliosis surgery + cast	0.5-3.4	[19,30-34]
Spinal cord injury	0.53	[21]
Burn injury	1.0-1.12	[22-24]
Anorexia nervosa (admitted)	2.73	[25]
Functional dyspepsia	10.8	[26]

Table 2 Etiology of superior mesenteric artery syndrome

Etiology		Ref.
Congenital
	Short or high insertion of Treitz ligament	[60]
	Low origin of the SMA	[35]
	Spinal deformity (Scoliosis, Marfan, etc.)	[36,37]
	Familial	[38,39]
	Malrotation of SMA and SMV	[40,41]
	Malrotation of intestine	[2]
Body weight loss
	Diet and obesity surgery (sleeve surgery)	[5,42]
	Eating disorders (anorexia nervosa, anorexia bulimia)	[25,36]
	Malabsorption	[17]
	Malignancy	[17,18,35]
	Tuberculosis	[44]
	Chemotherapy	[45,46]
	Trauma (Burn injury, brain injury, spinal cord injuries, etc.)	[22,47,48]
	Neural disorders (ALS, MELAS, paraplegia, cerebral palsy, etc.)	[49,50]
	Drug or alcohol abuse	[36]
	Rheumatoid arthritis	[51]
Scoliosis surgery		[19,30-34]
Intestinal surgery (IPAA, colectomy, etc.)		[36,52,53]
Aging (bed rest, frail, vascular calcification, etc.)		[54,55]
Body cast		[4-6]
"Pseudo-" SMA syndrome
	Aortic artery aneurysm (Aortoduodenal syndrome)	[56-58]
	Surgery near or around the SMA and 3rd duodenum	[59]

SMA: Superior mesenteric artery; SMV: Superior mesenteric vein; ALS: Amyotrophic lateral sclerosis; MELAS: Mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes; IPAA: Ileal pouch-anal anastomosis.

Table 3 Complications and comorbidities of superior mesenteric artery syndrome

Complications			Ref.
	Gastrointestinal complications 25%-59% in SMA syndrome		[62,73]
		Esophageal inflammation, bleeding, and ulcer	[60,80,81]
		Gastric inflammation, ulcer, emphysema, ischemia, necrosis, perforation, and bezoar	[82-85]
		Duodenal inflammation, ulcer, mucosal necrosis, emphysema, and bezoar	[63,64,86]
		Portal venous gas and thrombosis	[65,66,84]
		Pneumoperitoneum and pneumomediastinum	[67,68]
	Pancreato-biliary complications
		Elevated serum pancreatic and/or biliary enzymes	[69]
		Acute and chronic pancreatitis	[85]
		Jaundice	[70]
	Pulmonary complications
		Aspiration pneumonia	[71]
		Adult respiratory distress syndrome	[72]
	Dehydration
		Low blood pressure	[75]
		Acute kidney injury	[75]
		Shock	[75]
	Electrolytes and gas abnormalities
		Hypokalemia	[76]
		Hyponatremia	[76]
		Metabolic alkalosis	[76]
	Severe malnutrition		[77]
	Recurrent pregnancy loss		[78]
	Sudden death		[82]
Comorbidities related to SMA syndrome
	Nutcracker phenomenon		[87,88]
	Celiac axis compression syndrome (median arcuate ligament syndrome)		[89,90]

SMA: Superior mesenteric artery.

Table 4 Diagnostic modalities for superior mesenteric artery syndrome

Modalities
Plain film X-ray
Barium X-ray
Angiogram
CT
	Plain
	Enhanced (3D-CT)
Abdominal ultrasound
	B-mode
	Doppler-mode
MRI
	MR angiography
	MR enterography
Endoscopy
	White light imaging
	Ultrasonography (EUS)
Gastric-emptying scintigraphy
Multi-channel manometry

CT: Computed tomography; 3D: Three-dimensional; MRI: Magnetic resonance imaging; EUS: Endoscopic ultrasonography.

Table 5 Differential diagnoses of superior mesenteric artery syndrome

Disorders mimicking SMA syndrome			Ref.
Similar symptoms by...
	Eating disorder
		Anorexia nervosa, anorexia bulimia	[125]
	CIPO		[126]
	Peptic ulcer disease		[127]
	Reflux esophagitis		[101]
	Functional dyspepsia		[26]
	Cyclic vomiting syndrome		[102]
	Pancreatitis		[103]
	Gastric outlet obstruction		[104]
Involvement of duodenum by... (other disorders)
	Tubercular infection		[105,106]
	Megaduodenum (localized CIPO)		[107]
	Henoch-Schönlein purpura		[108-110]
	Crohn's disease		[111,112]
	Celiac disease		[86]
	Ectopic pancreas		[113]
	Duodenal diverticula		[114]
	Duodenal edema		[115]
	Tumor
		Primary or metastatic duodenal cancer, pancreatic cancer, lymphoma, etc.	[14,116]
	Anatomical abnormality (web, diaphragm)		[117]
	Foreign body (bezoar, etc.)		[118]
Extrinsic compression by... (non-SMA)
	Aortic artery aneurysm (Aortoduodenal syndrome)		[56-58]
	Stent or filter
		Mesenteric artery, aorta, IVC, etc.	[119,120]
	Horseshoe kidney		[121]
	Lymph node		[122]
	Abscess		[123]
	Traumatic false aneurysm		[124]

SMA: Superior mesenteric artery; CIPO: Chronic idiopathic intestinal pseudo-obstruction; IVC: Inferior vena cava.

Table 6 Treatments for superior mesenteric artery syndrome

Therapeutic methods
Conservative therapy
	Decompression of dilated stomach and duodenum by
		Postural change (left lateral, sitting position)
		Nasal gastric tube suction
		Medication (metoclopramide)
	Gaining weight by
		Giving multiple small feeds
		Feeding tube (nasal gastric or jejunal)
		Total parenteral nutrition
Surgical therapy
	Anterior transposition of the third part of duodenum
	Gastroduodenostomy
	Gastrojejunostomy
	Duodenojejunostomy
	Strong’s procedure (a division of the ligament of Treitz)
	Duodenal lowering
	Ladd's procedure
Endoscopic therapy
	Lumen-apposing metal stent1 by
		EUS-guided gastrojejunostomy

¹Lumen-apposing metal stent: Potential option based on case reports.

EUS: Endoscopic ultrasonography.