Association between Postoperative Adjuvant Vasodilator Therapy and In-Hospital Mortality for Non-Occlusive Mesenteric Ischemia: A Nationwide Observational Study.

Background: Although several clinical guidelines recommend vasodilator therapy for non-occlusive mesenteric ischemia (NOMI) and immediate surgery when bowel necrosis is suspected, these recommendations are based on limited evidence.

Methods: In this retrospective nationwide observational study, we used information from the Japanese Diagnosis Procedure Combination inpatient database from July 2010 to March 2018 to identify patients with NOMI who underwent abdominal surgeries on the day of admission. We compared patients who received postoperative vasodilator therapy (vasodilator group) with those who did not (control group). Vasodilator therapy was defined as venous and/or arterial administration of papaverine and/or prostaglandin E1 within 2 days of admission. The primary outcome was in-hospital mortality. Secondary outcomes included the prevalence of additional abdominal surgery performed ≥3 days after admission and short bowel syndrome.

Results: We identified 928 eligible patients (149 in the vasodilator group and 779 in the control group). One-to-four propensity score matching yielded 149 and 596 patients for the vasodilator and control groups, respectively. There was no significant difference in in-hospital mortality between the groups (control vs. vasodilator, 27.5% vs. 30.9%; risk difference, 3.4%; 95% confidence interval, -4.9 to 11.6; p=0.42) and no significant difference in the prevalences of abdominal surgery, bowel resection ≥3 days after admission, and short bowel syndrome.

Conclusions: Postoperative vasodilator use was not significantly associated with a reduction in in-hospital mortality or additional abdominal surgery performed ≥3 days after admission in surgically treated NOMI patients.