Movement of the superior mesenteric artery in patients with superior mesenteric artery syndrome: A case‐reference study

Abstract

Superior mesenteric artery (SMA) syndrome is related to the reduction of the aortomesenteric angle on detailed imaging studies; i.e., an expert's ultrasonography or angiography. We aimed to test a simpler imaging finding of SMA syndrome. This cross-sectional case-reference study examined whether right movement of the SMA on unenhanced computed tomography (CT) is useful for the diagnosis of SMA syndrome. We reviewed hospital records of patients admitted in 2008-2018. Each case was matched to one non-case patient of the same age and sex. On unenhanced CT scans, we identified the shortest distance between the parallel line that passes through the center of the aorta to the line that bisects the spine and SMA. A negative number of the distance means that the SMA is on the left side of the abovedescribed parallel line. There was a total of 14 cases and 14 non-cases (men, 57.1%) with mean age 78.7 years. Mean body mass index of cases and non-cases were 19.2 and 22.2 kg/m 2 , respectively. The more prevalent side of the SMA was the right side.The mean shortest distance was 10.5 mm in cases and 0.7 mm in non-cases (p for independent t test = 0.043). For comparing the observations in SMA cases at several time points, the mean shortest distance at pre-onset was À2.7 mm, with a significant difference from that at onset (p for paired t test = 0.030). In conclusion, right movement of the SMA diagnosed by unenhanced CT is associated with SMA syndrome.

Dynamic ultrasonography for optimizing treatment position in superior mesenteric artery syndrome: Two case reports and review of literature

“…Although it is believed that positioning the patient in the left lateral position is effective in the treatment of SMA syndrome, there is little evidence[ 13 , 16 ]. The optimal body position for each patient may vary because recent studies found a variation in the SMA position and movement[ 14 , 15 , 17 ]. Case 1 in our report demonstrated better content passage in the right lateral position than the left, corroborating the findings of Khan et al [ 15 ].…”

“…Case 1 in our report demonstrated better content passage in the right lateral position than the left, corroborating the findings of Khan et al [ 15 ]. Miyata et al [ 17 ] reported a variation in position of SMA demonstrating that major position was the right side along with the aorta[ 17 ]. No study has reported the optimal position in SMA syndrome[ 1 ].…”

“…While the left lateral recumbent position is generally considered to be effective in the treatment of SMA syndrome, literature on the optimal patient position is scarce[ 4 , 13 - 18 ]. Some reports suggest that the optimal position may not be limited to the lateral position but could include right recumbent and sitting positions, depending on the course of the SMA in relation to the aorta[ 14 , 15 , 17 , 18 ]. Therefore, the optimal position might differ for each patient, and we hypothesize that dynamic observation of the SMA-Ao distance by ultrasonography (US) is ideal to determine the optimal therapeutic position.…”

Superior mesenteric artery syndrome: Diagnosis and management

“…Positioning the patient in the left lateral or sitting position should be helpful[ 95 , 130 ]. However, the best position for each patient may vary because recent studies revealed there is a variation of the SMA position and movement[ 131 - 133 ]. In addition to gastric tube suction, intravenous metoclopramide can enhance gastrointestinal motility and help decompression[ 134 , 135 ].…”

Understanding Superior Mesenteric Artery Syndrome: Etiology, Symptoms, Diagnosis, and Management

“…The absence of visceral and retroperitoneal fat results in an angle between the AA and the SMA that is usually 6-25°, as opposed to the normal range of 38-56°, which can induce this uncommon and potentially fatal illness [ 3 ]. The aortomesenteric distance is also 2-8 millimeters instead of 10-20 [ 4 ].…”