Large stone in neobladder: percutaneous neocystolithotomy

Introduction

Urolithiasis represents a prevalent and challenging complication in individuals with urinary diversion, particularly those with a neobladder and Mitrofanoff conduit. Reported in up to 52% of such patients, it poses a significant burden, with recurrence rates up to 63% following intervention (1). The altered urinary physiology, mucus production, urinary stasis, and infection risk inherent to reconstructive urinary procedures contribute to an environment conducive to stone formation.

The ileal epithelium, with colonisation rates between 14% and 96%, harbours a diverse microbiota distinct from native urothelium, which normally inhibits bacterial adherence (1,2). Consequently, bacteriostasis is reduced and colonisation is often asymptomatic (2). Zhang et al. (3) reported recurrence rates of 30–32% following stone treatment, primarily due to persistent infections and asymptomatic carriage. Common organisms include Streptococcus spp. and Staphylococcus epidermidis in conduits, and Escherichia coli, Enterococcus faecalis, Enterococcus faecium, and Proteus mirabilis in ileal neobladders (4).

In ileal neobladders, recurrent urinary tract infections (UTIs), particularly with urea-splitting organisms, increase stone risk by generating ammonium and bicarbonate ions, the latter driving urinary alkalinisation and crystallisation of calcium phosphate and magnesium ammonium phosphate (5). The position of urinary drainage also influences stone incidence: rare at the reservoir base, but approximately 9% with urethral catheter drainage and up to 21–100% with Mitrofanoff conduits entering from above (6). Use of intestinal segments for reconstruction further predisposes to metabolic disturbances, including hyperchloraemic metabolic acidosis, hypercalciuria, hypocitraturia, and hyperoxaluria, collectively increasing risk for calcium phosphate, calcium oxalate, and struvite calculi (4,5).

Zhang et al. (3) also identified diabetes, hypertension, UTIs, and anastomotic stenosis as significant risk factors, consistent with findings by Taylor et al. (6) on diabetes and nephrolithiasis and Jeong et al. (7) on hypertension and stone disease. Additional contributors include foreign materials such as sutures, clips, stents, and catheters, which promote colonisation and calculi (8). Long-term reviews demonstrate a progressive rise in risk over time, reflecting the cumulative burden of infection, colonisation, and foreign bodies (9,10). Urolithiasis is thus a common and challenging complication in patients with neobladders and Mitrofanoff conduits (7), with stones capable of enlarging substantially and necessitating complex surgery if not detected early (11). While open cystolithotomy has been the traditional approach, it carries significant morbidity, prompting increasing adoption of minimally invasive alternatives (2).

We present the case of a 27-year-old male with a complex urological history, including bladder exstrophy managed with augmentation cystoplasty in 2006 and intermittent self-catheterisation (ISC) via a Mitrofanoff channel. In 2021, he underwent an open cystotomy for the removal of neobladder stones. He subsequently re-presented in 2024 with lower abdominal pain and recurrent UTIs. A computed tomography (CT) revealed a large 8 cm calculus within the neobladder (Figure 1). The patient had a markedly scarred abdomen (Figure 2). A multidisciplinary team (MDT) review determined that an open surgical approach would be best avoided due to his complex abdominal anatomy.

Figure 1 Coronal, axial, and sagittal CT images demonstrating a large neobladder calculus. CT, computed tomography.

Figure 2 Preoperative marking demonstrating the planned incision site for neobladder stone access. The entry point is identified 10 cm inferior to the Mitrofanoff channel and 6 cm lateral to the midline, selected to optimise exposure while avoiding damage to the neobladder and other surrounding structures.

The patient had undergone primary urethral closure at the time of the initial Mitrofanoff procedure. As a result, the native urethra was unavailable for intraoperative catheterisation.

In this narrated video (Video 1), we outline a contemporary percutaneous approach to neobladder stone management, utilising a dual-energy, single-probe suction lithotripter. This technique is designed to reduce complications and enhance procedural outcomes, particularly in patients with challenging anatomical considerations. We also discuss evidence-based strategies for stone prevention in this unique population. This article is presented in accordance with the SUPER reporting checklist (available at https://tau.amegroups.com/article/view/10.21037/tau-2025-509/rc).

Preoperative preparations and requirements

The procedure was performed at Launceston General Hospital, Tasmania by Urologist Doctor R.C. All procedures performed in this study were in accordance with the ethical standards of the institutional and/or national research committee(s) and with the Declaration of Helsinki and its subsequent amendments. Written informed consent was obtained from the patient for publication of this article, accompanying images and video. A copy of the written consent is available for review by the editorial office of this journal.

Preoperative cross-sectional imaging was carefully reviewed (Figure 1), and the precise coordinates for the incision and percutaneous tract were marked on the patient (Figure 2). Detailed planning was undertaken to establish the safest and most effective route of access. The right iliac fossa (RIF) was selected (Figure 2), as it provided the most direct trajectory to the calculus while minimising the risk of injury to adjacent viscera and the reconstructed bladder. This decision was informed by CT imaging, abdominal examination, and the distribution of prior surgical scars.

Under general anaesthesia, the patient was positioned supine and administered intravenous antibiotic (Augmentin). A 12 French (Fr) two-way indwelling catheter (IDC) was inserted via the Mitrofanoff channel, with a 5 mL balloon inflated.

Step-by-step description

Following sterile preparation, a 3 cm horizontal incision was made in the RIF, 10 cm below the Mitrofanoff and 6 cm lateral to the midline. The rectus abdominis was bluntly split, and the posterior sheath incised between two clips, with stay sutures placed for exposure. The neobladder was filled with 100 mL of saline. Intravesical entry was confirmed via 22 G needle aspiration.

A 3-0 Vicryl purse-string suture was placed in the anterior neobladder wall, through which a percutaneous needle and sensor guidewire were advanced. The tract was dilated to 24 Fr using a Nephromax^TM balloon dilator (Boston Scientific, Sydney, Australia), and a 12 cm working Amplatz sheath (Boston Scientific) inserted. A 24 Fr, 30° nephroscope was introduced, revealing a solitary, matrix-encrusted calculus. Lithotripsy was performed over 150 minutes using the Trilogy^TM dual-energy lithotripter (Boston Scientific) with integrated suction and stone catcher, achieving complete stone clearance.

The lithotripter was initially set at 70% impact, 70% ultrasound energy, 20% suction, and a frequency of 6 Hz. During the procedure, these settings were progressively increased to 90% impact, 80% ultrasound energy, 20% suction, and 10 Hz.

Final inspection showed intact neobladder mucosa without injury. The cystotomy was closed with the purse-string suture, followed by layered abdominal closure using 3-0 Vicryl and subcuticular Monocryl. Marcaine 0.5% was infiltrated for local analgaesia. In total, 218 g of calculous material was retrieved. Subsequent analysis confirmed the specimen to be struvite in composition, without any uric acid or cystine components.

Postoperative considerations and tasks

The Mitrofanoff catheter was secured to a drainage system, and appropriate wound dressings were applied to ensure optimal healing. The patient commenced a 1-week course of oral antibiotics and was instructed to continue ISC four times daily. An IDC was retained in the Mitrofanoff channel for one week, after which a cystogram was performed to assess integrity and neobladder healing. In addition, daily neobladder irrigations were conducted using a Terumo syringe to prevent mucus accumulation and reduce the infection risk within the urinary reservoir.

Tips and pearls

• Careful preoperative interrogation of cross-sectional imaging to coordinate access.
• Dilatation, not incision, of neobladder through a purse-string.
• Use of a dual energy suction lithotripter to manage the dependent stones.

Discussion

Neobladder urolithiasis remains a significant and recurring challenge in patients with continent urinary diversions, particularly those incorporating a Mitrofanoff conduit. The pathophysiology is multifactorial, driven by urinary stasis, chronic infection, mucus accumulation, and the absence of bacteriostatic properties within intestinal segments.

In this context, the case presented highlights not only the clinical complexity of stone recurrence in a reconstructed lower urinary tract but also the value of a minimally invasive, tailored percutaneous approach in managing large calculi when conventional open surgery is contraindicated.

In this patient, the urethra had been surgically closed, and urinary drainage was solely dependent on the Mitrofanoff channel. Given that the Mitrofanoff represented the only route for catheterisation, preservation of its integrity was paramount. Any stricture, perforation, or injury to the channel would compromise bladder emptying and render the patient unable to pass urine, a situation that would be catastrophic. For this reason, we deliberately avoided instrumentation with a flexible cystoscope or ureteroscope via the Mitrofanoff. Although such an approach is often used in conventional stone management, its use in this setting carries significant risk of channel damage. Similarly, the placement of an access sheath through the Mitrofanoff would introduce additional risk of trauma to both the channel and the augmented bladder.

Furthermore, the stone in this patient was large and located dependently within the neobladder. Laser fragmentation via flexible endoscopy in this anatomical context is often inefficient, as fragments tend to accumulate rather than wash out. Even with suction-assisted techniques, the risks associated with repeated instrumentation of the Mitrofanoff outweigh the potential benefits.

Our approach therefore prioritised the avoidance of Mitrofanoff instrumentation, recognising that preservation of the channel and augmented bladder is the most critical determinant of long-term functional outcome. This highlights a key advantage over traditional endoscopic strategies, which-while effective in native bladders-carry unacceptable risks when applied through a Mitrofanoff-dependent system.

Conventional percutaneous cystolitholapaxy (PCCL) is effective for bladder stones in native anatomy, using a suprapubic tract, sequential dilatation, and direct lithotripsy (12). However, it assumes normal pelvic anatomy and may be unsuitable for patients with reconstructed lower tracts or Mitrofanoff conduits, where standard access may risk injury to bowel or prior surgical planes. In this case, preoperative imaging guided a controlled extraperitoneal approach via the RIF, with purse-string entry and gradual dilatation to preserve reservoir integrity. Dual-energy suction lithotripsy enabled complete stone clearance without complication. This modified technique demonstrates how PCCL can be safely adapted for complex urinary reconstructions through tailored access and planning.

In patients with surgically altered pelvic anatomy, successful percutaneous stone management relies on several key principles: precise preoperative imaging, safe tract selection that avoids bowel and vascular structures, and techniques that preserve tissue integrity. Rather than sharp incisions, entry should be achieved through controlled dilation or purse-string sutures. Once access is established, modern lithotripters with integrated suction allow efficient stone fragmentation while minimizing mucosal trauma. Secure closure of the access tract is essential to restore reservoir integrity and prevent fistula formation. These foundational strategies enable safe and effective minimally invasive management in patients with neobladders, catheterisable channels, and other complex urinary reconstructions, providing an alternative to open surgery with reduced morbidity and faster recovery.

The success of our procedure relies on an MDT approach, both during the perioperative phase and throughout follow-up. Close collaboration between endourologists, paediatric urologists, radiologists, and interventional radiologists is essential for procedural planning and execution. Microbiology and infectious diseases specialists play a critical role in managing complex urinary cultures, multidrug-resistant organisms, and optimising antimicrobial therapy preoperatively. Long-term follow-up likewise benefits from a coordinated MDT approach. Micropathology and endocrinology input, together with dietitians, support metabolic evaluation and dietary stone prevention. In addition, device specialists and stoma care nurses contribute to maintaining optimal drainage, reducing the risk of recurrent stones, and preventing infection.

Given the rarity of such cases, it is difficult to define a standardised learning curve for this procedure. Nevertheless, successful outcomes depend on the surgeon’s prior expertise in percutaneous access and complex stone surgery. Surgeons undertaking this operation should have substantial experience with percutaneous techniques and a demonstrated portfolio of similar procedures.

While the procedure itself is uncommon, the decision-making process-particularly in selecting the most appropriate operative approach relies heavily on surgical judgement informed by prior experience. In cases involving very large stones, proficiency in percutaneous surgery is essential to ensure both safety and efficacy.

The foundational approach to preventing urolithiasis in patients with urinary diversions hinges upon adherence to meticulous behavioural practices designed to mitigate stone formation. Residual urine, as noted by prior studies, serves as a fertile medium for bacterial proliferation (11). Thus, regular and complete evacuation of urinary reservoirs—whether via timed voiding regimens or stringent catheterisation schedules—plays a pivotal role in averting urinary stasis and the accumulation of mucus and crystals known to precipitate calculi formation (4).

Patient education emerges as an indispensable component of this prophylactic framework. Instruction on neobladder emptying techniques, coupled with vigilant monitoring of post-void residuals, is paramount. As outlined by Herdiman et al. (13), strategies such as leaning forward to enhance intra-abdominal pressure or applying targeted suprapubic pressure can augment emptying efficiency. In cases of incomplete voiding, clean ISC offers an effective interim solution to prevent stasis until volitional voiding is restored. Furthermore, voiding schedules may be personalised based on individual urinary pH profiles; for example, alkaline urine necessitates extended intervals between voiding to preserve a more acidic urinary environment conducive to reducing stone risk (13).

Hydration also remains a cornerstone of prophylaxis. Beiko and Razvi (14) advocate for a daily intake of no less than two litres of fluid, establishing a strong baseline for urinary dilution and reduced crystallisation potential.

Beyond voiding practices, regular irrigation of the neobladder using sterile saline is widely endorsed to flush accumulated mucus and deter UTI and bladder stone formation (4,13,15). Empirical evidence supports this protocol: Hensle et al. (16) demonstrated a significantly lower incidence of pouch stones (7%) among patients adhering to irrigation regimens, compared to a markedly higher rate (43%) in those who did not. Similarly, Okhunov et al. (4) referenced findings by Terai et al. (17), indicating a lifetime stone formation risk of 5.4% with routine irrigation, versus 12% without it—underscoring the critical nature of this intervention.

Pharmacologic prophylaxis further complements these measures. The use of prophylactic antibiotics has been correlated with a reduced incidence of recurrent UTIs and a concomitant decrease in stone formation (11,15). Agents such as acetohydroxamic acid—an irreversible urease inhibitor—and aluminium hydroxide—which impedes gastrointestinal phosphate absorption—have shown efficacy in stone prevention (4,11,18). In cases involving residual calculi fragments, chemo-dissolution therapies such as hemiacidrin or Suby’s G solution may be employed to prevent regrowth (19,20). Additionally, the correction of metabolic derangements, including acidosis via bicarbonate supplementation, has garnered research interest (21). Oral supplementation targeting hypovolemia, hypocitraturia, and related abnormalities also contributes to the broader goal of slowing disease progression (4).

Individuals with urinary diversions—owing to the altered architecture, microbiota, and altered metabolic profiles—face a heightened risk of urolithiasis. Nevertheless, a comprehensive and multifaceted prophylactic strategy encompassing timely bladder emptying, consistent pouch irrigation, tailored pharmacologic support, and patient education offers a robust framework for mitigating this risk.

Conclusions

Percutaneous neocystolithotomy is a safe, minimally invasive, and effective alternative to open surgery for neobladder calculi. It should be the preferred approach in this high-risk cohort to minimise morbidity and preserve reconstructed anatomy. The procedure requires specialised surgical expertise, meticulous preoperative planning, and multidisciplinary collaboration. Advanced lithotripsy systems with integrated suction optimise efficiency and ensure complete stone clearance. Long-term outcomes depend on prevention through patient education, irrigation protocols, metabolic optimisation, and structured surveillance.

Acknowledgments

This work has been submitted for consideration for presentation at the 2026 European Association of Urology Congress in London, UK.

Footnote

Reporting Checklist: The authors have completed the SUPER reporting checklist. Available at https://tau.amegroups.com/article/view/10.21037/tau-2025-509/rc

Peer Review File: Available at https://tau.amegroups.com/article/view/10.21037/tau-2025-509/prf

Funding: None.

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://tau.amegroups.com/article/view/10.21037/tau-2025-509/coif). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. All procedures performed in this study were in accordance with the ethical standards of the institutional and/or national research committee(s) and with the Declaration of Helsinki and its subsequent amendments. Written informed consent was obtained from the patient for publication of this article, accompanying images and video. A copy of the written consent is available for review by the editorial office of this journal.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

References

1. Cohen TD, Streem SB, Lammert G. Long-term incidence and risks for recurrent stones following contemporary management of upper tract calculi in patients with a urinary diversion. J Urol 1996;155:62-5.
2. Suriano F, Gallucci M, Flammia GP, et al. Bacteriuria in patients with an orthotopic ileal neobladder: urinary tract infection or asymptomatic bacteriuria? BJU Int 2008;101:1576-9. [Crossref] [PubMed]
3. Zhang B, Xie H, Liu C. Risk factors of calculi in upper urinary tract after radical cystectomy with urinary diversion. Actas Urol Esp (Engl Ed) 2019;43:568-72. [Crossref] [PubMed]
4. Okhunov Z, Duty B, Smith AD, et al. Management of urolithiasis in patients after urinary diversions. BJU Int 2011;108:330-6. [Crossref] [PubMed]
5. Robertson WG, Woodhouse CR. Metabolic factors in the causation of urinary tract stones in patients with enterocystoplasties. Urol Res 2006;34:231-8. [Crossref] [PubMed]
6. Taylor EN, Stampfer MJ, Curhan GC. Diabetes mellitus and the risk of nephrolithiasis. Kidney Int 2005;68:1230-5. [Crossref] [PubMed]
7. Jeong IG, Kang T, Bang JK, et al. Association between metabolic syndrome and the presence of kidney stones in a screened population. Am J Kidney Dis 2011;58:383-8. [Crossref] [PubMed]
8. Gu J, He Z, Li H, et al. A giant neobladder stone with insignificant symptoms: A case report and literature review. Front Surg 2023;10:1105146. [Crossref] [PubMed]
9. Tinoco CL, Lima E. Urinary diversions for radical cystectomy: a review of complications and their management. Mini-invasive Surg 2021;5:28.
10. Muto G, Collura D, Simone G, et al. Stapled orthotopic ileal neobladder after radical cystectomy for bladder cancer: Functional results and complications over a 20-year period. Eur J Surg Oncol 2016;42:412-8. [Crossref] [PubMed]
11. Gacci M, Serni S, Frizzi J. Prevention and Treatment of Urinary Tract Infections After Radical Cystectomy, Diversion, and Reservoirs. In: Bjerklund Johansen TE, Cai T. editors. Guide to Antibiotics in Urology. Cham: Springer International Publishing; 2024:261-71.
12. Lee MS, Sledge TR, Seyer AK, et al. How I do it: percutaneous cystolitholapaxy for bladder stones with complex lower urinary tract anatomy. Can J Urol 2025;32:325-33. [Crossref] [PubMed]
13. Herdiman O, Ong K, Johnson L, et al. Orthotopic bladder substitution (Neobladder): part II: postoperative complications, management, and long-term follow-up. J Wound Ostomy Continence Nurs 2013;40:171-80; quiz E1-2. [Crossref] [PubMed]
14. Beiko DT, Razvi H. Stones in urinary diversions: update on medical and surgical issues. Curr Opin Urol 2002;12:297-303. [Crossref] [PubMed]
15. van den Heijkant M, Haider N, Taylor C, et al. Efficacy of bladder irrigation and surveillance program in prevention of urinary tract infections and bladder calculi in children with an ileocystoplasty and bladder neck repair. Pediatr Surg Int 2011;27:781-5. [Crossref] [PubMed]
16. Hensle TW, Bingham J, Lam J, et al. Preventing reservoir calculi after augmentation cystoplasty and continent urinary diversion: the influence of an irrigation protocol. BJU Int 2004;93:585-7. [Crossref] [PubMed]
17. Terai A, Ueda T, Kakehi Y, et al. Urinary calculi as a late complication of the Indiana continent urinary diversion: comparison with the Kock pouch procedure. J Urol 1996;155:66-8.
18. Griffith DP, Khonsari F, Skurnick JH, et al. A randomized trial of acetohydroxamic acid for the treatment and prevention of infection-induced urinary stones in spinal cord injury patients. J Urol 1988;140:318-24. [Crossref] [PubMed]
19. Philippou P, Moraitis K, Masood J, et al. The management of bladder lithiasis in the modern era of endourology. Urology 2012;79:980-6. [Crossref] [PubMed]
20. Brock WA, Nachtsheim DA, Parsons CL. Hemiacidrin irrigation of renal pelvic calculi in patients with ileal conduit urinary diversion. J Urol 1980;123:345-7. [Crossref] [PubMed]
21. Fasanella D, Marchioni M, Domanico L, et al. Neobladder “Function”: Tips and Tricks for Surgery and Postoperative Management. Life 2022;12:1193. [Crossref] [PubMed]