体外冲击波碎石术治疗单发肾结石成功的影响因素

Predictive factors of success outcome of extracorporeal shock wave lithotripsy for single renal calculus

目的探讨影响体外冲击波碎石术(extracorporeal shock wave lithotripsy,ESWL)治疗单发肾结石成功的因素。方法回顾2006-01至2012-08在我科碎石中心接受ESWL治疗的肾结石患者776例,结石大小为7～20 mm,排除最后需行输尿管镜和经皮肾镜等治疗的患者,最终入选82例。ESWL术后随访3个月,通过腹部平片和CT扫描未发现结石或残余结石<4 mm定为成功组,将残余结石>4 mm定为失败组。分析两组之间在年龄、性别、体重指数、结石大小、结石位置、结石患侧、皮肤至结石的距离、结石密度、碎石电压和碎石次数等因素的差异。结果成功组58例,失败组24例。统计学分析发现,年龄,性别,体重指数,结石大小、位置、患侧,以及碎石电压和碎石次数在两组之间无统计学差异,而皮肤至结石的距离和结石密度对疗效均有影响。Logistic回归分析进一步表明,皮肤至结石的距离和结石密度是两个独立的预测因子。结论皮肤至结石的距离和结石密度可作为临床预测单发肾结石体外碎石是否成功的有效预测指标。

Objective We investigated predictive factors for success of extracorporeal shock wave lithotripsy （ESWL） for treating single renal stones. Methods We retrospectively reviewed the records 776 patients who had undergone ESWL at this hospital between January 2006 and August 2012 for single renal stones sized from about 7 mm to 20 ram. We excluded patients treated with ureteral catheters and percutancous nephrostomy; ultimately, only 82 patients fulfilled our inclusion criteria. We classified the success group as those patients whose stones had disappeared or residual stone fragments 〈 4 mm on a CT scan and simple X - rays within 3 months after ESWL and the failure group as those patients in whom residual stone fragments 〉 4 mm after 3 months. We analyzed the differences between the two groups in age, sex, body mass index （BMI） , size of stone, stone location, stone laterality, skin - to - stone distance （SSD）, density （Hounsfield unit, HU）, voltage （kV）, and the number of shocks delivered. The statistically significant factors identities were further analyzed by multivariate logistic regression. Results The success group included 63 patients and the failure group included 19. In the univariate analysis, age, sex, BMI, the size of stone, stone location, stone laterality, kV and the number of shocks delivered did not differ significantly between the two groups. Only SSD, and HU were factors influencing success. The results of the multivariate logistic regression analysis showed SSD and HU to be the significant independent predictors of the ESWL stone - free rate. Conclusions The SSD and HU are useful clinical predictive factors of the success of ESWL on single renal stones.