Superior Mesenteric Artery Syndrome as Potential Cause of Antireflux Surgery Failure

BACKGROUND: Superior mesenteric artery syndrome (SMAS) is characterized by upper gastrointestinal symptoms, such as nausea, food regurgitation, vomiting, post prandial epigas- tric pain and weight loss. SMAS is commonly not recognized and many patients are considered as affected by gastro-esophageal reflux disease or specific gastrointestinal motility disorders. For this reason its diagnosis is frequently delayed, resulting in ineffective symptomatic therapies and inappropriate investigations. We aimed to investigate the occurrence of this misdiagnosis in a large group of patients who underwent surgical treatment for SMAS. Moreover, we assessed medical history and final outcome. METHODS AND PATIENTS: 27 consecutive SMAS patients who underwent surgical correction (duodenojejunostomy or duodenojejunostomy+duodenum resection) between 2008-2013 have been enrolled in this study. Six patients had a previous fundoplication which had been performed elsewhere. Two patients had more than one antireflux procedure. Demographic and clinical data (weight, BMI, medical therapy, symptom duration) were prospectively collected. Symptoms were scored by using a detailed lickert-scale based questionnaire for vomiting, nausea, epigastric pain, regurgitation and post-prandial bloating. Before the surgical treatment for SMAS, all patients have been investigated with CT and/or MR angiography with multi-planar three- dimensional reconstructions, endoscopy, barium swallow, esophageal manometry and 24 hour pH-monitoring. RESULTS: All six patients were PPI no-responders before the antireflux surgery and had persistent symptoms after the previous fundoplication. The median of symptom duration was 90 months. At SMAS preoperative evaluation, 5 patients had negative 24 hour pH-monitoring and normal LES resting pressure. Mean aorto-mesenteric angle was 21° +/-1.8 and distance 6 +/- 2.1 mm. In all patients a duodenojejunostomy was performed: in 5 patients a distal duodenum resection was added. The morbidity and mortality of SMAS surgery were nil. At a median follow-up of 48 months (IQR 37-55), the median of symptom score was significantly lower after surgery (28 vs 8; p<0.001). In all patients the symptoms score increased after SMAS surgery. There was a significant improvement in patients' weight (52+/-1 kg vs 57+/-9 kg p<0.01) and BMI (18.5+/-3.4 kg vs 20.6+/-3.4 kg; p<0.01) and there was a significant decrease of anti-reflux medications use (p<0.01). CONCLUSIONS: Patients with long lasting nausea, vomiting and gastroesophageal reflux who are not respond- ing to PPI therapy should be carefully considered for possible SMAS before performing an antireflux procedure. Moreover, patients who underwent a fundoplication and still remainedsymptomatic reporting gas-bloat syndrome or persistent reflux should be addressed to a study of the duodenum for a possible presence of SMAS.