Renal sinus exposure as an independent factor predicting asymptomatic unruptured pseudoaneurysm formation detected in the early postoperative period after minimally invasive partial nephrectomy

Abstract

OBJECTIVES: To investigate the incidence of asymptomatic unruptured renal artery pseudoaneurysm detected by 3-D computed tomography arteriography in the early period after minimally invasive partial nephrectomy, including laparoscopic and robotic partial nephrectomy. METHODS: From February 2012 to November 2013, 101 patients underwent minimally invasive partial nephrectomy for renal masses. Computed tomography arteriography was carried out 3-4 days after surgery; radiologists diagnosed renal artery pseudoaneurysm in a blinded manner. Factors influencing the occurrence of renal artery pseudoaneurysm were analyzed with the logistic regression model. RESULTS: The incidence of renal artery pseudoaneurysm was unexpectedly high at 21.7% when detected by computed tomography arteriography during the early period after minimally invasive partial nephrectomy. The renal artery pseudoaneurysm group showed a significantly larger tumor size (P = 0.02), significantly higher N component score (P = 0.01) and higher incidence of renal sinus exposure or opening of the collecting system (P < 0.01) compared with the no renal artery pseudoaneurysm group. Although these aforementioned factors were found to be significant by univariate analysis, multivariate analysis showed that renal sinus exposure was the only significant independent predictive factor for occurrence of renal artery pseudoaneurysm. Tumor-related factors, such as the N component of the nephrometry scoring system or tumor size, did not show an independent influence on the occurrence of renal artery pseudoaneurysm. CONCLUSIONS: The present study shows an unexpectedly high incidence of asymptomatic unruptured renal artery pseudoaneurysm detected by computed tomography arteriography in the early period after minimally invasive partial nephrectomy. Renal sinus exposure is an independent significant factor predicting the occurrence of renal artery pseudoaneurysm. Avoidance of deep excision into the renal sinus could reduce the risk of renal artery pseudoaneurysm.