STONE DISEASE

Percutaneous Nephrolithotomy in Patients Who Previously Underwent Open Nephrolithotomy
Margel D, Lifshitz DA, Kugel V, Dorfmann D, Lask D, Livne PM
Minimally Invasive Urology, Rabin Medical Center-Golda Campus, Petach Tikva, Israel
J Endourol. 2005; 19: 1161-4

• Background and Purpose: Open stone surgery nowadays is rare. However, some patients who are treated today have in the past undergone open nephrolithotomy. The aim of this study was to determine the possible impact of open nephrolithotomy on the efficacy and morbidity of subsequent percutaneous nephrolithotomy (PCNL).
• Patients and Methods: We reviewed the files of all 167 patients undergoing PCNL at our institution between December 2000 and December 2003. The same surgeon performed all of the procedures. We compared 21 patients undergoing PCNL after open nephrolithotomy to the same kidney with all other patients undergoing PCNL. The groups did not differ in terms of age or stone burden (mean size, number of stones, percentage with staghorn calculi). The outcomes measured were operating time, necessity for secondary procedures, stone free rate, and intraoperative and postoperative complications.
• Results: The operating time (203+/-92 v 177+/-52 minutes) and percentage of secondary procedures (29% v 12%) were significantly higher in patients who had previously undergone open stone surgery. However, the stone-free rate (95% v 93%), intraoperative complication rate (10% v 9%), and postoperative complication rate (10% v 11%) did not differ significantly.
• Conclusions: A PCNL in a patient with a history of open nephrolithotomy may take longer and lead to a higher percentage of auxiliary procedures, probably because of scar tissue and anatomic changes in the kidney. However, the morbidity and efficacy of PCNL appear to remain the same in these patients.
  
  
• Editorial Comment
  Preoperative planning for PCNL pays off particularly in the complicated patient who has a prior open renal surgery. Though the authors conclude that efficacy is not affected, the secondary procedure rate was significantly higher if the patient has had a prior open surgery. The authors present some important technical tips to consider during complicated PCNL. Firstly, they utilize contrast-imaging to evaluate for intrarenal scarring that would necessitate a direct puncture onto the stone. Secondly, they utilize an upper pole puncture if an incisional hernia is present at the old subcostal incisional site. Thirdly, they emphasize the need for precise initial alignment of the entry needle as the ability to maneuver the needle once inserted is limited by scarring. Lastly, they employ a step-wise algorithm for dilation of the percutaneous tract - starting with a balloon dilator, using a fascia cutting needle and re-inflating if residual waist is present, proceeding to rigid Amplatz dilators if still not successful, and lastly using telescopic metal dilators if all else fails. It is important to emphasize that experience in each of these techniques is important to ensure access to the stone in these complicated patients. Unfortunately, they did not report how often they resorted to each of these techniques. One can conclude from this study that patients undergoing PCNL who have had prior open renal surgery should undergo contrast-imaging studies to delineate the collecting system anatomy. Having the availability and experience of a range of dilation systems is important for successful percutaneous access.

Dr. Manoj Monga
Professor, Department of Urology
University of Minnesota
Edina, Minnesota, USA