Acute mesenteric ischaemia (AMI) accounts for 1–2% of acute abdominal emergencies [1, 2]. If untreated, AMI will cause mesenteric infarction, intestinal necrosis, an overwhelming inflammatory response and death. Despite the progress of diagnostic and treatment strategies for this vascular emergency, it remains a life-threatening disease with an overall mortality of 50–70% [3, 4, 5]. Superior mesenteric artery (SMA) occlusions by embolism (50%) and thrombosis (15–25%) are the most common causes of acute mesenteric ischemia. For the restoration of SMA blood perfusion to preserve the bowel, intra-arterial thrombolysis was reported as an adjunctive treatment modality to surgery for acute SMA occlusion. However, cases were reported sporadically; even in a large case series, the number of cases was scant [6, 7, 8, 9, 10]. The aim of this study was to present our experience with thrombolysis with local intra-arterial urokinase in 10 patients with acute SMA occlusion and analyze the outcome.
This retrospective study was approved by the institutional review board of the Chang Gung Memorial Hospital and the committee waived the requirement for informed consent for the use of anonymized and retrospectively analyzed data. Patients who underwent thrombolysis with intra-arterial urokinase for acute SMA occlusion between October 1, 2008, and December 31, 2019, were identified in the registry. Indication of thrombolysis: Patients who presented as acute abdomen and diagnosed as acute SMA occlusion on abdominal computed tomography (CT).
Patients presented with shock in the triage screening, acute peritonitis on physical examination, intramural gas, mesenteric or portal venous gas on abdominal CT were all excluded for the thromobolysis. During the study period, 11 patients were diagnosed as having acute SMA occlusion on abdominal computed tomography (CT) and were scheduled for intra-arterial urokinase treatment. One patient who underwent intra-arterial fragmentation alone due to mesentery contrast extravasation on angiography was excluded. The remaining 10 patients, who received intra-arterial urokinase infusions, were selected for this study.
The thrombolysis procedures were performed by experienced interventional radiologists. Under local anaesthesia, the right femoral artery was punctured in accordance with the Seldinger technique, and a 6-Fr sheath (Terumo, Tokyo, Japan), 10 cm in length, was implanted. Selective catheterization of the SMA was performed with 4-Fr catheter (J curve 80-cm, Terumo, Tokyo, Japan). The SMA angiography was performed to identify the filling defect. Thrombolysis was performed using a 5-Fr multiple-sideport infusion catheter (100 cm with sideport of 7 cm, 14 ports or 100 cm with sideport of 15 cm, 30 ports, Cook, Bloomington, IN, U.S.A). The tip of the microcatheter was embedded in the thromboembolism, which was fragmented at the time of thrombolysis. Thrombolysis was performed locally in the SMA with a bolus of urokinase (Urokinase-GCC Injection 250,000 IU) 300,000 IU in the first 3 patients and 250,000 IU in the next 7 patients), followed by a continuous infusion of urokinase (50,000 IU/hour) for 3 days, and intravenous heparin was administered simultaneously and under close monitoring and surveillance at the surgical intensive care unit. Follow-up angiography was usually performed once daily for 3 days or discontinued when clinical deterioration developed. The patients were discharged with a warfarin prescription. Data on age, sex, clinical presentation, imaging studies such as abdominal CT and angiography, location and degree of SMA occlusion, time and response to urokinase treatment, and clinical outcomes were evaluated retrospectively.
SMA occlusions were distinguished into proximal and distal occlusions, defined as thromboembolisms proximal and distal to the middle colic artery, respectively. The degree of SMA occlusion may be defined as complete (Fig. 1A, B) and incomplete (Fig. 2A, B), which refers to the main trunk of the SMA occlusion without and with distal branches, respectively. The degree of recanalization after intra-arterial urokinase therapy was described as total, near-total (Fig. 3A, B), partial (Fig. 3, C, D), and absent, referring to the dissolution of the thromboembolism with total, near-total, partial, and no restoration of blood flow on angiography, respectively.
Categorical data are presented as numbers, while continuous data are presented as median (interquartile range [IQR]) values. For comparisons of categorical data, the Fisher exact test or Pearson χ2 test was used as appropriate. For continuous data, the Mann-Whitney U test was used. All statistical analyses were performed using SPSS version 20.0 (IBM, Armonk, New York, USA). A P value of < 005 (two-sided) was considered statistically significant.