Isolated Superior Mesenteric Artery Dissection Following Liver Transplant: Report of 3 Cases

Isolated superior mesenteric artery (SMA) dissection (SMAD) is considered a relatively rare disease. Especially, isolated SMAD following liver transplant has been rarely reported.

Among 96 consecutive adult recipients who underwent liver transplant at our institution, 3 recipients (3.1%) demonstrated isolated noncommunicating SMAD, type IV according to Sakamoto's classification. Patient characteristics are the following: mean age, 53 years (range, 49-60 years); male to female ratio, 2:1, right lobe graft to left lobe graft ratio, 2:1; operating time, 760 minutes (range, 614-880 minutes); and blood loss, 6570 mL (range, 2435-13,329 mL). New onset of abdominal pain was noted in 33.3% (1/3). The diagnosis was made by the first follow-up computed tomography scan after liver transplant. The mean distance between the proximal end of SMAD and the root of SMA was 21.3 mm (range, 9-40 mm). There were no signs of ischemic changes in the small intestine in any of the 3 patients. Thus, conservative managements such as anticoagulation therapy were performed without other aggressive interventions. One patient died because of subarachnoid hemorrhage. In the other 2 patients, SMAD disappeared at 6 months following the diagnosis.

The morbidity of isolated SMAD is around less than 0.1% at the autopsy. Compared with this result, we found significantly higher morbidity rate in liver transplant recipients. It is true that mechanical stress from retraction of the stomach to the caudal end including the root of SMA may play an important role in the onset of SMA dissection.

Isolated SMA dissection following living donor liver transplant is a rare but potentially life-threatening condition. It is required to ascertain whether emergency revascularization should be considered.