734 ENHANCED COMPUTED TOMOGRAPHY AFTER PARTIAL NEPHRECTOMY IN EARLY POSTOPERATIVE PERIOD CONTRIBUTED TO DETECT PRE-RUPTURED RENAL ARTERY PSEUDOANEURYSM

Abstract

INTRODUCTION AND OBJECTIVES: Renal artery pseudoaneurysm (RAP) is a characteristic complication after partial nephrectomy (PN) and most cases are discovered after rupture. Five of 434 patients (1.2%) who underwent PN between 2005 and 2011 in our institute developed RAP and 80% of cases were symptomatic. Since 2012, patients who underwent PN have received enhanced computed tomography (CT) in the early postoperative period. We analyzed the occurrence rate of RAP in the early postoperative periods and whether CT screening is effective. METHODS: Between January 2012 and September 2012, 101 patients underwent PN in Tokyo Women’s Medical University Hospital. Of these, patients who could not undergo enhanced CT due to allergic reaction to the contrast agent or impaired kidney function were excluded from this study. Eventually, 87 patients were the subjects of this study. Patients received 3-dementional enhanced CT in the early postoperative period (in principle, 4th post operative day). One radiologist reviewed the CT images and diagnosed any RAP. Patient characteristics, tumor specific and surgical data were analyzed. RESULTS: Thirteen of 87 patients (15%) developed RAP. RAP occurred in seven of 55 patients (13%) in open partial nephrectomy and five of 32 patients (16%) in laparoscopic partial nephrectomy. One of 18 patients (6%) with a high complexity tumor (RENAL nephrometry score 10-12) was diagnosed with RAP, as were six of 38 patients (16%) with intermediate complex tumors (score 7-9) and six of 36 patients (17) with low complexity tumors (score 4-6). One patient was diagnosed by CT with 5mm diameter RAP on POD3, which enlarged to 29mm on POD9 and ruptured. The other was initially a small RAP (2.9mm) on POD4, but became enlarged to 6.8mm on POD6. She received angioembolization before rupture. Although three patients were diagnosed with small RAP (3mm, 4mm and 3mm, respectively) in POD4, their RAP became blocked by a blood clot in a few days. The other eight patients underwent angioembolization immediately after diagnosis. CONCLUSIONS: Screening by CT in the early postoperative period detected high rates of unruptured RAP. What type of unruptured RAP needs to undergo angioembolization cannot to be determined in this study because some small RAP enlarged in a short period after initial diagnosis.