Percutaneous cystolithotripsy in the reconstructed bladder of cloacal exstrophy: A case report

Background: Bladder stones are common after bladder augmentation. The management of bladder stones is challenging, especially in patients who underwent complex urinary tract reconstruction. Case Presentation: We report our experience of percutaneous cystolithotripsy after bladder neck closure, creation of a catheterizable channel, and ileal bladder augmentation in a girl with cloacal exstrophy. Conclusion: Percutaneous cystolithotripsy is a safe, effective, and minimally invasive treatment option for bladder stones after bladder neck closure and the creation of a continent catheterizable channel


INTRODUCTION
The bladder stone is one of the late complications of bladder augmentation with a reported incidence of 10% to 52%. [1] The management of bladder stones is challenging, especially in patients who have undergone complex urinary tract reconstruction. Different surgical options have been reported for stones in the reconstructed bladder: open cystolithotomy, endoscopic cystolitholapaxy, and percutaneous cystolithotomy. [2][3][4] We report our experience of percutaneous cystolithotripsy after complex urinary tract reconstruction in a girl with cloacal exstrophy. The objective of this report is to share our experience of managing stones in a reconstructed bladder that are difficult for endoscopic cystolitholapaxy through a continent catheterizable channel.

CASE REPORT
A female infant weighing 2574 g was delivered at 36 weeks gestation by Cesarean section because prenatal ultrasonography at 35 weeks gestation revealed an omphalocele with polyhydramnios. She was diag-nosed with cloacal exstrophy at birth. At 2 days of age, she underwent omphalocele closure, bladder closure, end colostomy using the hindgut, right end ureterostomy, pull-through vaginoplasty, and pubic approximation at another hospital. Postoperative cystography showed a vesicovaginal fistula. Subsequently, she developed bladder dehiscence. At 2 years of age, she was referred to our center for further management of urinary incontinence. Although we had planned to perform urinary tract reconstruction before the elementary school age, it had been impossible because of her private family matters. At 14 years of age, she underwent ileal bladder augmentation, creation of a continent catheterizable channel (Monti), bladder neck closure, bilateral ureteroneocystostomy, and closure of the vesicovaginal fistula (Fig.1). Postoperative cystography showed persistence of the vesicovaginal fistula (Fig.2a). At 15 years of age, she underwent re-closure of the vesicovaginal fistula. Although minor leakage was found on postoperative cystography, the fistula resolved with continuous bladder drainage for 3 months. She developed bladder stones 6 months post-procedure as evidenced by Ultrasound and X-ray KUB despite adequate daily bladder irrigation. The stones increased in number and size (25×13 mm, 25×13 mm, 8×8 mm), and she developed gross hematuria and lower abdominal pain (Fig.2b).  At 17 years of age, surgical intervention was performed for the bladder stones. A guidewire was fluoroscopically inserted through the catheterizable channel, and a ureteral access sheath (9.5/11.5 Fr) was placed. Cystolitholapaxy through the channel was considered to be impossible because it was quite difficult to secure a field of view even by a flexible endoscope due to the position of the stones and channel. Subsequently, we moved on to percutaneous cystolithotripsy (Fig.3). Under direct vision with the flexible endoscope, an 18-gauge angio-catheter was placed through the previous suprapubic tube tract in the left lower quadrant used at the time of urinary tract reconstruction. Through the angio-catheter, a guidewire was placed as a safety wire. The skin adjacent to the safety wire was incised, and a 10-mm laparoscopic trocar was placed under direct observation. A 9.5 Fr offset operating cystoscope was introduced into the bladder through the trocar. The flexible endoscope and ureteral sheath were removed, and a 12 Fr Nelaton catheter was placed through the channel to prevent overdistention of the bladder. The stones were fragmented using a Swiss LithoClast® Master-J (Boston Scientific Corp., Natick, MA, USA). The stone fragments were evacuated using a 26 Fr Nelaton catheter through the trocar. A 12 Fr balloon catheter was placed over the safety wire, and another balloon catheter was placed through the channel. The catheter through the trocar site was removed on postoperative day 7, and the catheter through the channel was removed on postoperative day 9. The postoperative course was uneventful. No stone was found on KUB 1 year after the surgery.

DISCUSSION
Bladder stones are common after bladder augmentation. Risk factors include urinary stasis, mucus, bacteriuria, and/or metabolic abnormalities. Urinary stasis can be attributed to incomplete emptying due to continent catheterizable channel and bladder neck closure. [1] The management of bladder stones in children who underwent such complex urinary tract reconstruction remains controversial. Different surgical options have been reported for stones in the reconstructed bladder: open cystolithotomy, endoscopic cystolitholapaxy, and percutaneous cystolithotomy. [2][3][4] Open cystolithotomy remains the preferred option to treat large or multiple stones in the reconstructed bladder. However, there is a concern about injury of the pedicles of the bowel used for augmentation.  [6] Although the bladder stones in our patient might have been caused by the 3-month catheterization after the closure of the vesicovaginal fistula, we selected a less-invasive approach taking recurrence into consideration.
In conclusion, percutaneous cystolithotripsy is a safe, effective, and minimally invasive treatment option for bladder stones after bladder neck closure and the creation of a continent catheterizable channel. This approach would be less traumatic if repeated surgeries for recurrent stones are needed in the future.

Conflict of Interest: None.
Consent to Publication: Author(s) declared taking informed written consent for the publication of clinical photographs / material (if any used), from the legal guardian of the patient with an understanding that every effort will be made to conceal the identity of the patient, however it cannot be guaranteed.
Authors Contribution: Author(s) declared to fulfill authorship criteria as devised by ICMJE and approved the final version. Authorship declaration form, submitted by the author(s), is available with the editorial office.