Series Gaur et al7 Micali et al8 Hemal et al9 *Mean 37.5 Table 1. Comparative Study of Published Series on Retroperitoneoscopic Pyelolithotomy Approach Retroperitoneal Transperitoneal Retroperitoneal No. of Patients 8 11 7 Age Range (Years) 22–65 22–75 21–55* M/F 6:2 — 5:2 Success 5 (62%) 10 (90%) 5 (71%) Operating Time (Minutes) 120 249 108.2 Blood Loss (mL) 15 132.9 127.2 suitable instruments are also not available for extraction of caliceal calculi. Though we did not use any flexible en- doscopes in this study, we believe that use of flexible endoscopes through the operating ports will help in lo- calization and extraction of caliceal calculi. Average op- erating time in other series ranged from 108 minutes to 249 minutes, which is substantially higher than that in our series (81 minutes). Blood loss in our study was 27 mL, which is comparable to that of other series, where it ranged from 15 mL to 132.9 mL. The time taken to resume normal activities was 1 0.3 days, which was very encour- aging, and the number of person-days lost was only 7.4 3.1 days. In the present era, ESWL is the preferred method of treat- ing kidney stones smaller than 3 cm. Although the proce- dure is noninvasive, shock waves often induce acute and occasionally chronic lesion to kidneys and other organs, and sequelae may include hypertension and loss of renal function. In a study by Eterovic et al,10 it was shown that while open pyelolithotomy from day one continuously improves renal function, ESWL first decreases it and then over a period of months at best brings it back to the pretreatment level. These reports suggest that retroperito- neal laparoscopic pyelolithotomy, having procedural sim- ilarity to open pyelolithotomy, is not only nephron- sparing but also nephron-reviving and, consequently, could eventually become accepted as the procedure of choice in select patients with renal calculus disease. Renal stones larger than 3 cm often require multiple ESWL or PCNL sessions, or both, with adjuvant endoscopic pro- cedures and exposure to ionizing radiation in PCNL. Even after this, some patients may not be completely stone free. RP can make these patients completely stone free in a single sitting with the added advantage of not being inva- sive to kidneys. However, this difference between RP and other procedures is more pronounced when either the stone is large or multiple calculi are present. Retroperito- neoscopic pyelolithotomy can also be used in staghorn calculi, and the patient becomes stone free in a single sitting as compared with percutaneous nephrolithotomy, which requires multiple sittings, exposing the patient to ionizing radiation.11 Another advantage is that many aux- iliary procedures like pyeloplasty and ureteric surgeries can be carried out in the same sitting.12 For patients with ectopic kidney, the results of ESWL are only moderately successful and PCNL is difficult; RP is a viable alternative in such situations. Various authors13,14 have reported the laparoscopic approach for renal stones in patients with ectopically located kidney because the results of other minimally invasive techniques are only moderately successful. A history of previous open surgery on the kidneys is a relative contraindication, though we did not include any patient with previous surgery in our study. A large number of patients with renal calculus disease in the developing countries are still being treated by an open operative procedure, as either the modern minimally in- vasive modalities are not available or they are beyond their access due to economical reasons. RP can be con- sidered an economically viable minimally invasive tech- nique for these patients in developing countries like India. RP has a steep learning curve because of the relative absence of landmarks and the paucity of space, which makes this surgery difficult for beginners. The only con- stant landmark is the psoas muscle, but for surgeons experienced in open renal surgery, the learning curve is definitively shorter. Despite the learning curve, no signif- icant complications occurred in this study. There is always a paucity of space in retroperitoneoscopic surgery, and Gaur et al7 reported the “striking of handle” and “cross sword effect” due to it. However, in our study, we did not encounter such a problem due to judicious and strategic placement of ports. We feel the placement of ports in a triangular manner obviates this problem. Contrary to this, Gaur et al placed all the ports in a single line, which could JSLS (2005)9:97–101 99