Prospective study of preoperative factors predicting intraoperative difficulty during laparoscopic transperitoneal simple nephrectomy

OBJECTIVE: To prospectively study and identify, the preoperative factors which predict intraoperative difficulty in laparoscopic transperitoneal simple nephrectomy. PATIENTS AND METHOD: Seventy seven patients (41 males and 36 females) with mean age of 43 ± 17 years, undergoing transperitoneal laparoscopic simple nephrectomy at our institute between February 2012 to May 2013 were included in this study. Preoperative patients' characteristics recorded were: Gender of patients, history of intervention, palpable lump, BMI, urine culture, side, size of kidney, fixity of kidney on USG, perinephric fat stranding on preoperative CT scan, periureteral fat stranding, perinephric collection, enlarged hilar lymph nodes, renal vascular anomalies, differential renal function on renogram. Preoperative factors of these patients were noted and intraoperative difficulty in the surgery was scored between 1 (easiest) to 10 (most difficult or open conversion) by a single surgeon (who was a part of all studies either as operating surgeon or assistant). Using SPSS 15.0 software, multivariate and univariate analysis was done. RESULTS: In multivariate analysis presence of pyonephrosis on preoperative evaluation and BMI < 25kg/m(2) were found to be statistically significant factors predicting intraoperative difficulty during laparoscopic simple nephrectomy. On univariate analysis following factors were associated with increased surgeon's score: Lower BMI, palpable kidney, pyonephrosis, history of renal intervention, perinephric fat stranding, right side, fixity of kidney on USG with surrounding structures. CONCLUSION: Our findings suggest that presence of pyonephrosis as identified on preoperative imaging and a BMI of less than 25 Kg/m(2) are the most significant factors predicting intraoperative difficulty during laparoscopic simple nephrectomy.