肾部分切除术后肾动脉假性动脉瘤形成的危险因素分析

Risk factors of renal artery pseudoaneurysm following partial nephrectomy

目的探讨肾部分切除术后发生肾动脉假性动脉瘤（RAP）的危险因素。方法2003年7月至2010年5月，肾细胞癌行肾部分切除术患者464例，术后发生RAP5例（1．1％）。均为男性，左侧2例，右侧3例。对肾部分切除术的手术方法、RAP的临床表现、影像学特点及治疗进行回顾性分析。肿瘤的解剖学特征按照肾脏测量评分系统进行定量分析。结果5例RAP肾脏测量评分总分8～10分，属中、重度复杂性肿瘤。肿瘤直径3．6cm，平均2．5～5．0cm（直径评分1—2分）。4例呈外生性生长，其中3例≥50％肿瘤体积位于肾实质内（外生部分所占比例评分2分），1例为完全内生性肿瘤（外生部分所占比例评分3分）。肿瘤与肾集合系统的距离均≤4mm（距离集合系统或肾窦评分3分）。4例肿瘤跨越肾极线和（或）肾中轴线（位置与极线关系评分3分），1例位于下极线下方（位置与极线关系评分1分），但肿瘤靠近肾门。5例术后3—23d，平均12d，发生肉眼血尿和不同程度贫血，4例伴有背部疼痛，2例有明显低血容量表现，分别输血1000ml和1800ml。增强CT和选择性动脉造影检查显示RAP主要来源于肾段动脉分支。4例经超选择性动脉栓塞治愈（3例栓塞1次，1例2次），1例栓塞治疗失败行患肾切除。随访12～30个月，平均21个月，5例肾功能正常，RAP无复发。结论肾部分切除术后迟发血尿的患者均应警惕RAP的可能性。肿瘤位置及其与肾段动脉分支的关系可能是发生RAP的危险因素。选择合适病例、仔细缝合血管断面和肾实质可减少RAP的发生。早期选择性动脉栓塞是RAP首选治疗方法。

Objective To study the risk factors of renal artery pseudoaneurysm （RAP） following partial ncphrectomy. Methods Open partial nephrectomy was performed on a total of 464 cases of renal cell cancer from July 2003 to May 2010. Five patients （1.1%） had postoperative hemorrhage from RAP. The surgery technique of the open partial nephrectomy, the clinical presentation, imaging findings and treatment of RAP were reviewed. The anatomical characteristics of these five renal tumors on enhanced CT were quantified using the R. E. N. A. L. Nephrometry Score System. Results All five cases were male, two had tumors on the left side and three on the right side. Median tumor size was 3.6 cm （ range from 2.5 to 5 cm; Radius score 1 - 2）. Four tumors were exophytic of these, three had a major endophytic component （≥50%） deep in the parenchyma （Exophytic/endophytic score 2）, one was entirely endophytic （score 3 ）. The distance of all the tumors to the collecting system was ≤4 mm （ Nearness score 3 ）. Four of the five tumors were across the polar line and/or renal axial midline （ Location score 3 ）. The other tumor was located under the lower pole （ 1,ocation score 1 ） but close to the renal hilar. All patients presented with delayed gross haematuria and decreasing hemoglobin occurred on mean postoperative day 12 （3 -23 day）. Four patients complained of flank pain, two of which had signs of hypovolemia requiring blood transfusion. The diagnosis was confirmed by the contrast medium-enhanced CT and selective angiography, and RAP was found most commonly arising from the segmental branch of renal artery. Superselective microcoil angioembolization was successfully performed in four cases, once in three cases and twice in the remaining case. The procedure failed in one patient and a nephrectomy was done. At a mean follow-up of 21 months （12 -30） , all patients had normal renal function without evidence of recurrence. Conclusions RAP should be considered in all patients who had delayed hematuria after partial nephrectomy. A central, deep tumor and its relationship to the segmental branch of renal artery could be an important risk factor for this complication. Choosing the case properly for partial nephreetomy and suturing the transeeted vessels and the defect of parenehymal correctly could reduce occurrence of this serious complication. Early use of selective angioembolization could be a pri- mary choice of treatment.