Experience with endoscopic Holmium laser in the pediatric population.

Introduction: Due to unavailability of suitable endoscopic instruments, pediatric patients have not benefited fully from the technological advances in the endoscopic management of the upper urinary tract. This limitation may be overcome with the Holmuim:Yttrium-Aluminum-Garnet (Ho:YAG) laser delivered via small instruments. To date, there is no published report on the use of this modality in children. Purpose: We evaluated the indications, efficacy, and complications of endourological Ho:YAG laser surgery in the treatment of pediatric urolithiasis, posterior urethral valves, ureterocele and ureteropelvic junction obstruction. Methods: The patient population included 10 children with renal, ureteral and bladder calculi, 2 children with posterior urethral valves, 2 children with obstructing ureteroceles, 2 children with ureteropelvic junction obstruction and I child with a urethral stricture. Access to the lesions was either antegrade via a percutaneous nephrostomy tract or retrograde via the urethra. A solid state Ho:YAG laser with maximum output of 30 watts (New Star lasers, Auburn, CA) was utilized as the energy source. Results: A total of 10 patients underwent laser lithotripsy. The mean age of the patients was 9 yrs (5-13 yrs). The average surface area of the calculi was 435.2 mm(2) (92-1645 mm(2)). 8 of the patients required one procedure to render them stone free, one patient had a staghorn calculus filling every calyx of a solitary kidney requiring multiple treatments and one other patient with a staghorn calculus required 2 treatments. There were no complications related to the laser lithotripsy. Two newborn underwent successful ablation of posterior urethral valves. Two infants underwent incision of obstructing ureteroceles with decompression of the ureterocele on postoperative ultrasound. Two children underwent endopyelotomy for ureteropelvic junction obstruction. One was successful an done required an open procedure to correct the obstruction. One child underwent a successful direct visual urethrotomy for a urethral stricture. Conclusions: The Ho:YAGs ability to pulverize urinary calculi make it an obvious choice for lithotripsy in children. The advantages of this technology are the ability to precisely apply the laser using small fibers, and the laser's ability to pulverize calculi with minimal trauma to surrounding tissue. The Ho-YAG laser is also superior to other modalities in the treatment of secondary ureteropelvic junction obstruction. We do not feel the Ho:YAG laser is superior to the current treatment methods for the treatment of posterior urethral valves and obstructed ureteroceles.