Risk Factors Related With Retroperitoneal Laparoscopic Nephrectomy Of Nonfunctioning Renal Tuberculosis Converted To Open Surgery

Objective: To investigate the risk factors affecting conversion to open surgery in retroperitoneal laparoscopic nephrectomy of nonfunctioning renal tuberculosis.Methods: The records of 144 patients(57 male, 87 female) undergone retroperitoneal laparoscopic nephrectomy procedure by a single surgeon between May 2007 to May 2014 were retrospectively reviewed. Mean age was 47.9±11.9 years(range 16–76 y). Among these patients, 21 cases were complicated with diabetes, and 38 were complicated with hypertension. According to BMI classification published by WHO in 2004, patients were divided into three groups(<25 kg/㎡: 55 cases, 25 ~ 35 kg/㎡: 57 cases, ≥ 35 kg/㎡: 32 cases). Lesions in 75 cases were on left side, 69 on right side. The size of kidney were evaluated by CT scan(<10cm: 53 number of cases, 10 ~ 12cm: 67 number of cases, > 12cm:24cases). Among these patients, 65 cases were complicated with calcification, and 38 were complicated with contralateral hydronephrosis. Preoperative CT scan showed a total of 18 cases patients had mild perirenal exudation, no moderate or severe perirenal exudation was detected. Pre-operatively 37 cases were treated with anti-tuberculosis therapy for <1 month, 66 cases for 1 to 3 months, and 41 cases for >3 months. The following factors including age, sex, body mass index(BMI), diabetes status, hypertension status, side of kidney, size of kidney, degree of calcification, mild perirenal exudation, contralateral hydronephrosis, the time of anti-tuberculosis, and surgeon experience were evaluated. Univariate analysis and multivariate step regression analysis were used for statistical assessment. Univariate analysis was first done by c2 test through SPSS17.0. Multivariate Logistic regression analysis was carried out among those significant risk factors in univariate anaylsis. P <0.05 is considered significant statistically.Results: Twenty-three out of 144 patients were converted to open surgery. In the univariate analysis, BMI(P=0.023), diabetes status(P=0.003), hypertension status(P=0.011), size of kidney(P=0.032) were the risk factors affecting conversion to open surgery in retroperitoneal laparoscopic nephrectomy of nonfunctioning renal tuberculosis. Age(P=0.104), gender(P=0.378), side(P=0.357), degree of calcification(P=0.231), mild perirenal exudation(P=0.264), contralateral hydronephrosis(P=0.071), the time of anti-tuberculosis(P=0.548) and surgical experiences(P=0.315) were not the risk factors. Multivariate stepwise regression analysis showed that BMI≥30 kg/ ㎡( OR=6.412, 95%CI: 1.284-32.024), diabetes status(OR=7.307, 95%CI: 2.015-26.496), hypertension status(OR=6.258,95%CI: 1.923-10.367) and enlargement of kidney(OR=8.380, 95%CI: 1.476-47.584) increased the risk of conversion to open surgery.Conclusion: BMI≥30 kg/㎡, diabetes, hypertension, enlargement of kidney are the risk factors affecting conversion to open surgery in retroperitoneal laparoscopic nephrectomy of nonfunctioning renal tuberculosis.