STONE DISEASE

A prospective randomized comparison of type of nephrostomy drainage following percutaneous nephrostolithotomy: large bore versus small bore versus tubeless
Desai MR, Kukreja RA, Desai MM, Mhaskar SS, Wani KA, Patel SH, Bapat SD
Department of Urology, Muljibhai Patel Urological Hospital, Nadiad, India
J Urol. 2004; 172: 565-7

• Purpose: We compared postoperative outcomes among tubeless, conventional large bore nephrostomy drainage and small bore nephrostomy drainage following percutaneous nephrostolithotomy (PCNL) in a prospective randomized fashion.
• Materials and Methods: Between January and June 2001, 30 patients undergoing PCNL were randomized to receive conventional large bore (20Fr) nephrostomy drainage (group 1, 10 patients), small bore (9Fr) nephrostomy drainage (group 2, 10 patients) or no nephrostomy drainage (group 3, 10 patients). Inclusion criteria included a single subcostal tract, uncomplicated procedure, normal preoperative renal function and complete stone clearance. Factors compared among the 3 groups were postoperative analgesia requirement, urinary extravasation, duration of hematuria, duration of urinary leak, decrease in hematocrit and hospital stay.
• Results: The postoperative analgesic requirement was significantly higher in group 1 (217 mg) compared to groups 2 (140 mg, p <0.05) and 3 (87.5 mg, p <0.0001). Patients in group 3 had a significantly shorter duration (4.8 hours) of urinary leak through the percutaneous renal tract compared to patients in groups 1 (21.4 hours, p <0.05) and 2 (13.2 hours, p <0.05). Hospital stay was significantly shorter in group 3 (3.4 days) compared to groups 1 (4.4 days, p <0.05) and 2 (4.3 days, p <0.05). All 3 groups were similar in terms of operative time, duration of hematuria and decrease in hematocrit. Postoperative ultrasound did not reveal significant urinary extravasation in any case.
• Conclusions: Tubeless PCNL is associated with the least postoperative pain, urinary leakage and hospital stay. Small bore nephrostomy drainage may be a reasonable option in patients in whom the incidence of stent dysuria is likely to be higher.
  
  
• Editorial Comment
  In an effort to reduce the morbidity of percutaneous nephrostolithotomy (PCNL), making it more competitive with ureteroscopy and SWL for the management of renal calculi, some practitioners have reduced the size of the post-PCNL nephrostomy tube or eliminated the tube altogether. Although tubeless PCNL has clear demonstrable advantages over traditional large bore, nephrostomy tubes with regard to hospital stay and pain medication requirements, the advantages of a small caliber nephrostomy tube have been less clear-cut in published trials. However, the use of a small caliber tube has the advantage of allowing reentry into the collecting system if needed, but potentially incurs less discomfort postoperatively.
  Desai and colleagues performed a prospective, randomized trial comparing the three approaches to post-PCNL tube management in 30 patients undergoing uncomplicated PCNL requiring a single, subcostal percutaneous access. Although the three groups were comparable with regard to postoperative complications, the tubeless group required significantly less pain medication post-PCNL, the nephrostomy tract sealed quickest and hospital stay was shortest. However, the small caliber tube group had less pain and shorter duration of urine leakage compared with the than the large caliber group.
  Although the study groups were small and the study perhaps underpowered to detect small differences between the groups, there clearly appeared to be an advantage to no nephrostomy tube or a small nephrostomy tube. The authors offered an algorithm for tube selection that is provides a reasonable approach for tube selection post-operatively. In cases in which a stone free status is fairly certain (for example, simple “pluck-and-run” procedures) after a relatively simple, bloodless procedure, the tubeless approach is a good option. For cases in which the stone is complex, the stone burden large or the procedure complicated or bloody, a large bore nephrostomy tube is advisable. For other procedures that are uncomplicated and not associated with a large blood loss (the majority of procedures), a small caliber nephrostomy tube is likely to reduce patient discomfort but does not preclude second look flexible nephroscopy in the event residual stones are detected.

Dr. Margaret S. Pearle
Associate Professor of Urology
University of Texas Southwestern Med Ctr
Dallas, Texas, USA