Effects Of Percutaneous Nephrolithotomy On Renal Functions: A Randomized Study Comparing Holmium Laser And Pneumatic Lithotripsy

Objective: To compare the effects of holmium laser and pneumatic intracorporeallithotripsy on renal function in percutaneous nephrolithotomy (PCNL), and observe thechanges in renal function of patients undergoing PCNL, in order to provide a basis foroption of treatment and prevention of postoperative complications.Methods: From August2010to March2011, we performed percutaneousnephrolithotomy on100patients with kidney stones in our department. The patients whohad double kidneys or single kidney stone without previous operation or other diseaseswere included in our study. We prospectively evaluated100patients by randomizing theminto two groups, treated using pneumatic (PL)(n=50) or laser lithotripter (LL)(n=50).The patients were evaluated with respect to age, gender, stone size, complications, andstone-free rates1month after the operation. The preoperative, operative, and post-operativefollow-up results of renal function were analyzed and contrasted, including serumcreatinine、blood urea nitrogen value and diuretic renogram.Results:1. Concentrations of serum creatinine and urea nitrogen in both PL and LL groupincreased at2-24h after operation, and decreased to the normal standard at1-7days afteroperation. No significant difference existed between the two groups (P>0.05).2. Dieresis renograms revealed that the peak and the renal index were abnormal beforeoperation, but recovered to normal level at7days-1month after operation in both PL andLL group. It did not show any significant difference between the two groups (P>0.05).3. In PL group, serum creatinine and urea nitrogen values of postoperative2hours and24hours showed significant difference, compared with that of preoperative (P <0.05), butno significant difference existed between7days-1month and preoperative (P>0.05).Dieresis renograms revealed that the peak and the renal index at7days-1month after surgery were different from that at preoperative (P <0.05).4. In LL group, serum creatinine and urea nitrogen values of postoperative2hours and24hours showed significant difference, compared with that of preoperative (P <0.05), butno significant difference existed between7days-1month and preoperative (P>0.05).Dieresis renograms revealed that the peak and the renal index at7days-1month aftersurgery were different from that at preoperative (P <0.05).5. For the PL and LL groups, mean ages (54.4+/-12.3and53.2+/-15.2years),male/female ratios (32:18and29:21) and stone locations were similar (p>0.05). Meanstone sizes were26.3mm(2) and27.0mm(2) in the PL and LL group, respectively, with nostatistically significant difference (p>0.05). Mean operative times were42.4min in the PLgroup and45.9min in the LL group, with no statistically significant difference (p>0.05).Stone-free rates1month after intervention were86%in the PL group and92%in the LLgroup (p>0.05). No major complication was found in either group.Conclusion:1. Both PL and LL are effective and safe modalities in treating kidney stones withminor insignificant differences. No significant difference of effects on renal function existsbetween the two groups.2. Both pneumatic and holmium laser lithotripsy can cause temporary acute kidneyinjury postoperative2hours and24hours, but recovered to normal level at7days-1monthafter operation, indicating that postoperative renal dysfunction is transient and reversible.3. Although laser lithotripsy has a higher stone-free rate compared with holmium laserlithotripsy. A pneumatic system may be more efficient with regard to the cost-benefit ratio,which was not studied in the present work; further studies should address this issue.