The Mitrofanoff continent urinary diversion is commonly used in paediatric patients with neuropathic bladder disorder. Although the continence achieved is up to 80%, some complications may occur as such as stoma strictures or bladder lithiasis. The anatomic features, the lithiasis burden and the preservation of the Mitrofanoff's are among the principal criterias for the selection of the best surgical access for the treatment of the stones in this patients,.

In this video a 32-year-old male with bladder exstrophy was treated of a lithiasis by percutaneous approach and endoscopic assistance. A Mitrofanoff continent catheterizable augmentation entero-cystoplasty was performed eighteen years ago. Over the last year he referred urinary chronic infection. In the imaging tests a lithiasis of 6 cm in the pouch was diagnosted. The surgical technique was performed under general anaesthesia and antibiotic profilaxis was administered. Firstly, the bladder was explored by a flexible endoscope through the Mitrofanoff. Due to the lithiasis burden and the history of chronic infections a supplementary access was performed to assiss the surgery. Subsequently, two amplatz sheaths (24 ch and 30 ch) were placed percutaneously under direct vision above the stoma and in the left and right medium clavicular line respectively. Although in our case the surgery was performed with a conventional nephroscope, miniaturized instruments could be used as optional facilities to disminished the surgical impact in children1. The lithiasic fragmentation was completed by a lithotriptor (Swiss LithoClast®) through the 30 ch sheath. After that, the large fragments were placed into an endobag inserted through the supplementary access and transferred extracorporeally. Smaller stones were also graspered with the nephroscope through the 30 ch amplatz. The procedure was completed safely in 75 minutes. The use of the endobag favoured the extraction of the fragments and it was very efficient. We also reduced the use of the lithotriptor for the fragmentation of the lithiasis inside the pouch, which may be related with less trauma in the bladder wall and thus less risk of infections for the patient. The stoma was preserved and was only used for the initial exploration and for the placement of the sheahs. No damage of the Mitrofanoff's access was reported during the surgery. After the completion of the procedure the fascia of the 30 ch access was closed and a catheter was placed through the 24 ch and the stoma.

The fragmentation and removal of the stone was complete with no complications. The suprapubic catheter was removed after 48h. A self-limited haematuria was present postoperativelly, therefore the Mitrofanoff catheter was maintained for 3 weeks. However, fever was not reported and blood transfusión was not required. The hospital stay was 2 days and the renal function was always maintained within the regular parameters.

The percutaneus treatment of bladder stones is an option for patients with bladder augmentation with a Mitrofanoff valve. This technique is feasible, simple, reproducible and preserves the integrity of the Mitrofanoff. In the event of new stones, the procedure could be repeated with a short hospital stay and a minimum of complications.

Bibliography.

1. Ciftci H, Gumus K, Demir M, Yilmaz MO, Gulum M, Yeni E, Akin Y. Endoscopic cystolithotomy by mini nephroscope: a preliminary study. Minim Invasive Ther Allied Technol 2015;24(2):114-8.