You will be presented with a collection of medical randomized controlled trial (RCT) reports addressing a shared clinical question -- for instance, the efficacy of a medical intervention on a disease or condition. Given the titles and abstracts of these reports, your task is to generate the conclusion of the systematic review article synthesizing the key findings. Your conclusion should be a few sentences long. In your response, include only the conclusion and no other text. The RCT reports are below.



Title 1:
Percutaneous nephrolithotomy in patients with previous open nephrolithotomy: one-shot versus telescopic technique for tract dilatation.
Abstract 1:
BACKGROUND AND PURPOSE  Percutaneous nephrolithotomy ( PCNL ) can be done in patients who have previously had open nephrolithotomy . Currently , dilatation of the nephrostomy tract is achieved using an Amplatz renal dilator or telescopic metal dilators in these patients . The aim of this study was to compare the safety and efficacy of the " one-shot " procedure in patients with previous open nephrolithotomy with those of the current telescopic technique . PATIENTS AND METHODS Thirty-one patients with past history of open surgery for kidney stone disease underwent PCNL at our institution from February 2006 to March 2007 . Patients were r and omly divided into two groups according to dilation technique used : group A ( telescopic procedure ) and group B ( one-shot procedure ) . X-ray exposure , blood loss , and complications were evaluated . RESULTS No significant difference in hemoglobin decrease was seen in the two groups . The stone-free and complication rates were the same in the two groups . Fluoroscopy time during the one-shot procedure was significantly shorter than that of the telescopic procedure ( P < 0.000 ) . CONCLUSION Our experience indicated that the one-shot procedure is feasible in patients with previous open nephrolithotomy . It is as safe and effective as the telescopic procedure , with significant reduction in x-ray exposure


Title 2:
One-stage tract dilation for percutaneous nephrolithotomy: is it justified?
Abstract 2:
PURPOSE To assess the feasibility of one-stage acute dilation of the nephrostomy tract with a 30F Amplatz dilator in patients who are c and i date for percutaneous nephrolithotomy ( PCNL ) regardless of whether there is a previous renal scar to make the procedure less time consuming and more cost effective . PATIENTS AND METHODS The outcomes of one-stage tract dilation for PCNL in 100 consecutive patients with and without a history of ipsilateral open stone surgery ( OSS ) , treated by one surgeon , were examined prospect ively . Forty-six patients ( group 1 ) had a history of ipsilateral OSS , and 54 patients ( group 2 ) did not have this history . Demographic data as well as intraoperative information , such as access time and radiation exposure time during access , were recorded . The success of the access technique and its bleeding complications were analyzed between the two groups . RESULTS By applying a " one-stage " technique , the targeted calix could be entered with a success rate of 93 % . There was no difference in the procedural success rate between groups 1 and 2 ( 93.5 % v 92.6 % , respectively ) . All seven failed attempts ( 7 % ; three with previous OSS ) were managed successfully using an Alken dilator to gain access to the proposed calix in the same session . Previous OSS did not impact access time , radiation exposure time during access , postoperative hemoglobin drop , and bleeding complications . There were no visceral and vascular injuries . CONCLUSIONS One-stage tract dilation for PCNL is a safe and effective method in almost every adult patient


Title 3:
Renal parenchymal damage after percutaneous nephrolithotomy with one-stage tract dilation technique: a randomized clinical trial.
Abstract 3:
PURPOSE To compare the effects of one-stage vs gradual dilation techniques during  percutaneous nephrolithotomy ( PCNL )  on postoperative renal scar formation and overall renal function . PATIENTS AND METHODS Of 152 adult patients who underwent surgery during the study period , 48 were r and omized 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 . RESULTS 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-99 m 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 ) . CONCLUSION 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
Our results show that One-shot dilation is an effective and safe procedure for tract creation in PCNL , with shorter access time and X-ray exposure time and without increased complications .