Evaluation of the K-wire technique for external urinary drainage in pediatric laparoscopic pyeloplasty.

INTRODUCTION: Urinary drainage is usually left in place after laparoscopic pyeloplasty to limit the risk of complications, such as urinary leakage. The procedure is sometimes laborious and complications may occur.

PURPOSE: Prospective evaluation of the Kirschner technique for urinary drainage during pediatric laparoscopic pyeloplasty.

STUDY DESIGN: This technique (Upasani et al., J Pediatr Urol 2018) involves introducing a nephrostomy tube (Blue Stent) with a Kirschner wire during laparoscopic transperitoneal pyeloplasty. We evaluated this technique by analyzing 14 consecutive pyeloplasties (53% on female patients, median age 10 years (6-16 years), on the right side in 40%) performed by a single operator between 2018 and 2021. The drain and urinary catheter were clamped and the perirenal drain removed on day 2. The stent was removed during consultation between days 7 and 15.

RESULTS: The median duration of surgery was 155 ± 7 min. Urinary drainage was installed within 5 min, without the need for radiological control and with no complications. All drains were correctly placed, with no drain migration or urinoma. Median hospital stay was 2 ± 1 days. One patient developed pyelonephritis (D8). The stent was removed without difficulty or complications. One patient presented an 8-mm lower calyx urinary stone at two months, revealed by macroscopic hematuria, necessitating extracorporeal shock wave lithotripsy.

DISCUSSION: The study design was based on a homogeneous series of patients, without comparison with another drainage technique or procedures performed by another operator. A comparison with other techniques might have been informative. Before this study, we tested various types of urinary drainage, to optimize performance. This technique was considered the simplest and least invasive.

CONCLUSION: External drain placement with this technique was rapid, safe, and reproducible in children. It also made it possible to test the tightness of the anastomosis and to avoid the need for anesthesia for drain removal.