Bladder stone as the first clue to a hidden vesicovaginal fistula: diagnostic and surgical insights from a multidisciplinary approach—a case report

Introduction

In clinical practice, women presenting to urology departments with urinary complaints such as dysuria, hematuria, or bladder stones are frequently presumed to have primary urinary tract disorders. However, several gynecologic conditions—including congenital anomalies, fistulas, and retained foreign bodies—can masquerade as urological disease. Recognizing this overlap is crucial to avoid diagnostic errors and suboptimal treatment.

Vesicovaginal fistula (VVF) represents an abnormal communication between the bladder and vagina (1), resulting in continuous urinary leakage and profound psychosocial distress. Most VVFs are iatrogenic or obstetric in origin, whereas those secondary to vaginal foreign bodies are extremely rare (2). Cases complicated by upper urinary tract abnormalities such as hydronephrosis or giant ureters are even less frequently reported.

Here, we present a case in which a young woman initially sought urological evaluation for bladder stone—an apparently common condition—but was ultimately diagnosed with a complex urogynecologic pathology involving a long-retained vaginal foreign body, VVF, and bilateral giant ureters. This case highlights not only the diagnostic and surgical challenges but also the ethical, psychological, and educational considerations surrounding such presentations. We present this article in accordance with the CARE reporting checklist (available at https://tau.amegroups.com/article/view/10.21037/tau-2025-aw-760/rc).

Case presentation

Clinical presentation and initial evaluation

A 20-year-old female presented with persistent lower urinary tract discomfort and urinary leakage for 2 years. She denied abdominal pain, distension, or menstrual irregularities. No psychiatric or surgical history was reported, and her renal function was within normal limits [serum creatinine 73.9 µmol/L, estimated glomerular filtration rate (eGFR) 100.96 mL/min/1.73 m²]. However, contrast-enhanced computed tomography (CT) demonstrated a mild decline in right renal excretory function, suggesting that renal impairment secondary to long-standing hydronephrosis had already begun.

CT performed at a local hospital revealed an intravesical foreign body associated with a large bladder stone, irregular bladder wall thickening, and bilateral megaloureters. The findings suggested “a VVF and possible passage of a foreign body from the genital tract into the bladder” (Figure 1A-1E). The exact size of the fistulous tract was not clearly delineated on CT. The patient was referred to our department for further evaluation.

Figure 1 Imaging studies (CT and X-ray) indicating the presence of a vaginal foreign body with a giant bladder stone, bilateral megaureters, and hydronephrosis. (A) 3D reconstruction from CT images shows bilateral megaureter dilation and deformation. (B) X-ray illustrates the presence of a large stone and a Y-shaped foreign body. (C) CT demonstrates bilateral hydronephrosis. (D,E) Axial CT images show the bladder and high-density stone within the bladder. 3D, three-dimensional; CT, computed tomography.

Gynecological examination revealed a normal vulva and uterus, but a widened vaginal canal suggested a possible communication with the bladder. Perineal ultrasonography detected a Y-shaped structure measuring approximately 2.5 cm on the left side of the urethra, 0.9 cm from the anterior vaginal wall, surrounded by a strong circular echo, corresponding to the metallic component embedded within the bladder stone. Combined with imaging findings, these results raised suspicion for a retained vaginal foreign body complicated by a VVF and secondary bilateral giant ureters.

A summary of the clinical course, interventions, and follow-up timeline is provided in Table 1.

Surgical method

Given the chronic inflammatory changes, large stone burden, and presence of a VVF, a combined transabdominal and transvaginal approach was planned to achieve complete exposure and watertight closure. This open dual-access strategy was selected over a purely minimally invasive (laparoscopic/robotic) approach because the foreign body and stone were impacted between the bladder and vagina with dense fibrosis, the vaginal opening of the fistula was deeply located and not adequately visualized transabdominally, and reliable multilayer closure under direct vision on both sides was prioritized to minimize the risk of persistent leakage and ureteral injury.

Under general anesthesia, the patient was placed in the lithotomy position. A midline suprapubic incision was made, and the bladder was carefully dissected and exposed. Upon opening the anterior bladder wall, an irregular stone was identified at the bladder base, with a Y-shaped metallic hairpin as its nidus. The stone and foreign body were impacted between the bladder and vagina. The bladder mucosa exhibited extensive follicular and polypoid hyperplasia, which severely obscured the ureteral orifices (Figure 2). Using oval forceps, the metallic foreign body was carefully extracted (Figure 3), and the ureteral orifices were clearly identified. Under guidewire guidance, bilateral Double-J stents were placed to ensure ureteral drainage.

Figure 2 Intraoperative views. (A,B) Exposure of the foreign body and wound. The red circles highlight the foreign body and part of the stone exposed during surgery. (C,D) Handling of the impacted foreign body and post-extraction wound repair. Image (C) shows the transabdominal bladder incision closure, and (D) shows the repair of the vesicovaginal fistula.

Figure 3 Extracted Y-shaped metallic foreign body with the giant bladder stone. Note the Y-shape of the metallic foreign body, which acted as the nidus for giant bladder stone formation.

A 2-cm vesicovaginal fistulous tract was observed at the bladder base. The tissue around the tract was densely fibrotic and adherent. The bladder side of the fistula was closed with 2-0 absorbable sutures in two continuous layers, achieving a watertight repair. The vaginal opening of the fistula was deeply located and could not be adequately visualized from the abdominal route. After intraoperative consultation with the gynecology team and confirmation that the hymen was not intact, a transvaginal route was used to directly expose and repair the vaginal side of the fistula with 2-0 absorbable sutures in two continuous layers, ensuring complete closure without additional incision.

Diluted methylene blue was instilled into the bladder to confirm the absence of leakage. The bladder anterior wall was then closed in two layers with absorbable sutures, and the abdominal incision was closed layer by layer. This dual approach allowed precise repair under direct vision from both sides, preserved organ function, and minimized unnecessary tissue manipulation.

Postoperative recovery

The postoperative course was uneventful. The urethral catheter was maintained for 5 days, during which no urine leakage was observed. The patient was discharged on postoperative day 7 with instructions to avoid bladder overdistension and sexual activity, maintain adequate hydration, and void regularly every 2–3 hours.

At 1 month postoperatively, bilateral double-J ureteral stents were removed under local anesthesia. Five months after stent removal (i.e., 6 months after surgery), CT urography (CTU) demonstrated marked improvement in bilateral hydronephrosis and previously dilated ureters, with no evidence of contrast extravasation into the vagina (Figure 4). The distal intramural portions of both ureters remained mildly thickened and irregular, consistent with chronic inflammatory changes. Urinalysis revealed leukocyte esterase (3+), microscopic hematuria, and alkaline cloudy urine (pH 8.0), indicating a low-grade urinary tract infection, which was treated successfully with culture-guided antibiotics.

Figure 4 CTU performed 5 months after ureteral stent removal (6 months after surgery). (A) 3D reconstruction of the bilateral ureters. (B) Marked improvement of bilateral hydronephrosis and ureteral dilatation with no evidence of vaginal contrast extravasation. (C) Preoperative axial CT images at the level of the bladder fistula show heterogeneous enhancement suspicious for inflammatory changes. 3D, three-dimensional; CT, computed tomography; CTU, computed tomography urography.

At the 6-month postoperative review, the patient reported marked improvement in urinary control and daily quality of life, with stable renal function and no radiologic or clinical evidence of recurrent fistula. She received counseling regarding bladder training, infection prevention, and follow-up planning, with psychological support offered as needed.

All procedures performed in this case were in accordance with the ethical standards of the institutional and/or national research committee(s) and with the Helsinki Declaration and its subsequent amendments. Written informed consent was obtained from the patient for publication of this case report and accompanying images. A copy of the written consent is available for review by the editorial office of this journal.

Discussion

A urological presentation revealing a gynecologic pathology

This case illustrates how an apparently straightforward urological presentation—bladder stone—can conceal a complex gynecologic pathology. Such overlap challenges clinicians to adopt a broader diagnostic perspective. In young women, recurrent urinary infections, incontinence, or bladder stones should prompt suspicion for gynecologic causes such as fistulas or congenital anomalies.

In contrast to men, in whom bladder stones are often secondary to bladder outlet obstruction caused by prostatic enlargement (3), the occurrence of a large bladder stone in a woman is distinctly uncommon. When encountered, it should raise immediate concern for underlying conditions such as VVF, neurogenic bladder, chronic infection, or retained foreign bodies. Recognizing this difference is essential, as misattributing the cause to isolated infection may delay detection of a more complex underlying pathology.

Diagnostic challenges and the role of imaging

Diagnosis of foreign body-related VVF (4-6) is often delayed because patients may feel embarrassed or deny prior events, preventing accurate history-taking (7,8). Imaging plays a pivotal role: CT and ultrasonography are sensitive for detecting retained foreign bodies, delineating fistulous tracts, and assessing upper tract function (9).

In our patient, CT revealed early decline of right renal excretory function despite normal serum creatinine, emphasizing the importance of functional imaging beyond biochemical indicators. In such complex cases, a combined anatomical-functional assessment provides essential guidance for both surgical planning and postoperative follow-up.

Interdisciplinary surgical management

The combined transabdominal and transvaginal approach exemplified the value of urology-gynecology collaboration (Table 2) (10,11). Intraoperative findings of dense fibrosis and a deep vaginal fistula necessitated dual access for adequate exposure and complete closure. Both vesical and vaginal openings were repaired with 2-0 absorbable sutures in two continuous layers to ensure watertight closure.

Timing of fistula repair remains controversial. Some authors advocate delayed repair after 3–6 months to allow inflammation to subside, particularly for newly formed fistulas, devitalized tissues, active cystitis, or radiation injury (12). However, in this patient, the fistula had existed for approximately 2 years, with chronic infection and fibrosis already stabilized; simultaneous repair at the time of stone and foreign body removal was therefore deemed appropriate (11,13). Comparable reports have similarly described the feasibility of combined transabdominal and transvaginal repair in complex VVF settings (14). Early postoperative healing validated this decision.

After completion of the repair, a diluted methylene blue solution was instilled into the bladder to confirm closure integrity. Although this dye test offers a convenient and inexpensive intraoperative tool for detecting leakage, it is not a gold standard. Cystoscopy and postoperative imaging remain the definitive modalities for evaluating fistula integrity. The choice of methylene blue testing in this case reflected a pragmatic intraoperative strategy, balancing accuracy, simplicity, and procedural efficiency.

Importantly, the transvaginal route was adopted only after gynecologic confirmation that the hymen was not intact, ensuring ethical prudence and minimizing potential psychological or social concerns in a young female patient. This combined approach allowed precise closure while maintaining minimal invasiveness and cosmetic benefit.

Secondary giant ureters and functional implications

Bilateral giant ureters identified intraoperatively were most consistent with a secondary (acquired) process rather than a primary congenital megaureter. A plausible mechanism is chronic obstruction and inflammation at the ureteral orifices related to mechanical compression from the impacted foreign body and chronic cystitis (14). Upper urinary tract dilatation improved on CTU 5 months after stent removal (6 months after surgery), supporting a substantial reversible component; however, congenital, reflux-related, or functional contributors cannot be fully excluded in a single case. Because dedicated functional studies (e.g., diuretic renography, voiding cystourethrography, or urodynamics) were not performed, definitive etiologic classification remains a limitation.

Functional and psychological recovery

Although anatomical closure was achieved, mild persistent leakage can occur due to bladder dysfunction after prolonged inflammation and stone-related irritation. Accordingly, postoperative management should include structured bladder training, infection surveillance, and symptom-guided follow-up. In young patients, clinicians should incorporate patient-centered communication and offer psychosocial support when distress or stigma interferes with disclosure, adherence, or recovery.

Clinical and practical implications

Several lessons can be drawn from this case:

• Diagnostic vigilance: in women with bladder stones—especially young or premenopausal—clinicians should actively exclude gynecologic or systemic causes such as VVF, foreign bodies, or chronic infections;
• Imaging and functional evaluation: combine anatomical imaging with renal excretory assessment to detect early dysfunction;
• Surgical decision-making: dual approach may be necessary for deeply seated or adherent fistulas; watertight double-layer closure with absorbable sutures is recommended;
• Timing of repair: chronic, fibrotic fistulas without active inflammation can be safely repaired in a single stage during stone removal;
• Assessment of closure: intraoperative methylene blue dye testing is a practical adjunct but not a substitute for cystoscopic or radiographic confirmation;
• Upper tract protection: temporary stenting is effective for secondary giant ureters, avoiding unnecessary reconstruction;
• Postoperative care: avoid bladder overdistension, ensure adequate drainage, and provide structured psychological and functional rehabilitation;
• Education and ethics: cultural sensitivity, family communication, and sexual health education are essential components of holistic management.

Conclusions

A young woman presenting with bladder stone was ultimately diagnosed with a VVF and bilateral upper urinary tract dilatation associated with a retained vaginal foreign body.

In contrast to male patients, in whom bladder stones are often associated with outlet obstruction, the presence of a large bladder stone in a female should prompt evaluation for underlying fistulas, voiding dysfunction, chronic infection, or gynecologic pathology.

Accurate diagnosis requires multidisciplinary evaluation, targeted imaging, and attention to upper urinary tract function. Management should be individualized with clear rationale for surgical approach and timing, and follow-up imaging can help confirm closure and recovery of urinary drainage.

A patient-centered perioperative plan—including counseling on bladder function and psychosocial needs—may further support long-term recovery.

Acknowledgments

None.

Footnote

Reporting Checklist: The authors have completed the CARE reporting checklist. Available at https://tau.amegroups.com/article/view/10.21037/tau-2025-aw-760/rc

Peer Review File: Available at https://tau.amegroups.com/article/view/10.21037/tau-2025-aw-760/prf

Funding: This study was supported by the Key Research and Development Plan in China (grant No. 2017YFB1303100), the National Natural Science Foundation of China (grant Nos. 82202911 and 82300786), Shenzhen Medical Research Fund (grant No. B2302054), Hubei Provincial Natural Science Foundation Projects (grant Nos. 2023AFB210 and 2024AFB640), and Wuhan Talent Plan Funds (grant No. 02.05.22030029).

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://tau.amegroups.com/article/view/10.21037/tau-2025-aw-760/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 case were in accordance with the ethical standards of the institutional and/or national research committee(s) and with the Helsinki Declaration and its subsequent amendments. Written informed consent was obtained from the patient for publication of this case report and accompanying images. 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/.

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