To compare the effects of one-stage vs gradual dilation techniques during percutaneous nephrolithotomy (PCNL) on postoperative renal scar formation and overall renal function. Of 152 adult patients who underwent surgery during the study period, 48 were randomized into two groups. In group 1 (n=19), gradual tract dilation with Alken metallic dilators was used, and in group 2 (n=29), one-stage tract dilation was used. We compared patient demographics, intraoperative and preoperative parameters, postoperative overall renal function, and renal scar formation on the target renal pole. Access time (P=0.001; 95% confidence interval [CI]: 3.19-6.30) and radiation exposure during access (P=0.03; 95% CI: 0.03-0.66) were significantly shorter in group 2. In group 1, the decrease in mean technetium-99m dimercaptosuccinic acid (99m-Tc DMSA) uptake from 44.1±20.1% to 43.4±19.6% 4 weeks postoperatively (-0.7%±0.5%; P=0.27; 95% CI: -0.56-1.93) was not significant. In group 2, however, there was a significant decrease in post-PCNL 99m-Tc DMSA uptake 2 (-2.4±0.3%, from 50.1±13.5% to 47.7±13.8%; P=0.001; 95% CI: 1.13-3.66). Four weeks after surgery, new scar formation or progression of the preoperative scar at the site of access were seen in 14 of 29 (48.3%) patients who were treated with one-stage dilation whereas only 2 of 19 (11.0%) patients who were treated with gradual dilation developed new scarring at the access site (P=0.007). Although the one-stage tract dilation technique reduced radiation exposure and access time, in the short term, it may cause more parenchymal damage than the gradual dilation technique.

Purpose: Previous renal surgery is a relative contraindication to laparoscopic nephrectomy because adhesion formation makes surgical dissection difficult. We determined whether previous surgery at the same anatomical site would affected the surgical outcome in patients who underwent transperitoneal laparoscopic nephrectomy. Materials and Methods: During the study period 79 consecutive patients who underwent transperitoneal laparoscopic nephrectomy were evaluated prospectively. All patients had symptomatic nonfunctioning small or hydronephrotic kidneys. Patients were divided into 29 with and 50 without prior surgery at the same anatomical site. Previous surgery included open nephrolithotomy in 16 patients, percutaneous nephrolithotomy in 8, open and percutaneous nephrolithotomy in 3, pyelolithotomy in 1 and pyeloplasty in 1. Results: Patients who underwent prior surgery were older than patients who did not (average age 46.6 vs 34.9 years, p = 0.008). Other patient characteristics, including gender ratio, body mass index and side of surgery, did not differ significantly between the 2 groups. Mean operative time was longer in patients with previous surgery than in the other group (98.6 vs 62.3 minutes, p = 0.03). Other operative data, including blood loss, intraoperative and postoperative complications, open conversion and hospital stay, were similar in the groups. One case per group was converted to open surgery due to difficult pedicle dissection. Conclusions: Transperitoneal laparoscopic nephrectomy in patients with a history of ipsilateral renal surgery can be done safely in timely fashion. Although mean operative time was longer, there was no significant increase in the operative complication rate in patients with prior surgery.