Impacted urethral stone, associated with a urethral stricture in a young male; presenting as acute retention of urine: a case report

¹University of Health and Allied Sciences, School of Medicine, Faculty of Surgery, Ho, Ghana, ²Department of Surgery, Ho Teaching Hospital, Ho, Ghana

^&Corresponding author
Frank Obeng, University of Health and Allied Sciences, School of Medicine, Faculty of Surgery, Ho, Ghana

Introduction    

Urolithiasis ranks as the third most common pathology of the urinary tract, following urinary tract infections and prostatic diseases [1]. Urethral calculi, however, are an uncommon presentation, accounting for approximately 0.3% of all urolithiasis cases [2]. These stones are more common in males due to anatomical differences, as females have a shorter and wider urethra [2]. Urethral stones may either migrate from the upper urinary tract or form primarily within the urethra, the latter often associated with underlying conditions such as urethral strictures, diverticula, or urethroceles [1]. They obstruct the posterior urethra in about 88% of cases, though they can also affect the anterior urethra [2,3]. Management varies from meatotomy and stone extraction to retrograde manipulation, cystolitholapaxy, lithotripsy, or urethrotomy [4].

This case report presents a rare case of a 24-year-old male patient with a presentation of painful haematuria, acute urinary retention, and a proximal urethral stone complicated by a stricture in the bulbar urethra. The report underscores the significance of timely diagnosis and highlights the importance of appropriate surgical intervention in cases where conservative measures may not be feasible. The patient was treated with an open urethrolithotomy followed by a substitutive urethroplasty using a buccal mucosa graft, with favourable functional and anatomical outcomes. This case highlights the challenges of managing such conditions in low-resource settings and emphasizes the need for accurate diagnostic tools and surgical expertise.

Patient and observation     

Patient information: a 24-year-old male (weight = 92 kg, height = 1.77 m; BMI = 29.37 Kg/m²) presented with a 6-day history of painful haematuria and a 2-day history of acute urinary retention with occasional urine leakage. He had no prior lower urinary tract symptoms or history of urolithiasis, recurrent urinary tract infections (UTIs), or urethral trauma. His medical history included treatment for a sexually transmitted infection (STI) a year prior and alcohol use. His lifestyle involved low water intake (less than 2.5 litres daily), regular consumption of fizzy drinks, and a diet with above-average red meat intake. The patient had no family history of urolithiasis.

Clinical findings: on examination, the patient was afebrile, mildly dehydrated, with a blood pressure of 128/73 mmHg and a pulse rate of 105 bpm. A tender bladder was palpable, but there were no scrotal swellings or urethral induration. Perineal examination revealed no palpable calculus, and digital rectal examination was normal.

Timeline of current episode: the patient initially presented with painful haematuria, frequency, and strangury on day 1. On day 3, he was diagnosed with a bladder calculus and started on oral ayurvedic medication at a primary health centre. By day 5, he developed acute urinary retention, which was managed with a needle cystostomy at a rural health facility (where he first presented). On day 6, he was referred to our centre for further evaluation and management.

Diagnostic assessment: initial laboratory tests showed a haemoglobin level of 13.8 g/dl, a total white blood cell count of 5.23 x 10⁹/L, and urinalysis indicating a urinary tract infection with elevated leukocyte esterase activity and numerous pus and red blood cells (>30/HPF). Urine culture identified E. coli, sensitive to levofloxacin. Renal function tests were normal, with a creatinine of 76.31 μmol/L and urea of 2.01 μmol/L. Imaging included: an abdominopelvic ultrasound (Figure 1) showed a normal upper urinary tract, a full bladder, and a proximal urethral stone; a retrograde urethrogram (ROU, Figure 2) revealed the calculus and a stricture in the bulbar urethra; additionally, a micturating cystourethrogram (MCUG, Figure 3) demonstrated an opening of the bladder neck during straining to void.

Diagnosis: the patient was diagnosed with a proximal urethral stone complicated by a stricture in the bulbar urethra. Differential diagnoses considered included bladder calculus and other causes of urinary retention.

Therapeutic interventions: the initial management included a suprapubic cystostomy (placed on continuous drainage) for urinary diversion, intravenous fluids (normal saline), and antibiotics consisting of intravenous ceftriaxone 2 g daily and gentamicin 80 mg every 8 hours, which were later switched to IV levofloxacin 500 mg daily based on urine culture results. Intravenous paracetamol was also administered for pain management.

Definitive management: six weeks on, the patient underwent an open urethrolithotomy followed by substitutive urethroplasty. At this surgery, a 1.5 cm x 0.5 cm bulbar urethral calculus was retrieved distal to the short (1.0 cm) mucosal urethral stricture. The resulting 4.0 cm urethrotomy wound at the bulbar urethra was repaired with a (ventral onlay) buccal mucosa graft. The contiguous mucosal trauma related to the local effect of the stone, in addition to the otherwise short stricture (leading to a 4.0 cm long urethrotomy wound), made us consider the buccal mucosal substitutive urethroplasty instead of an anastomotic urethroplasty.

Under aseptic conditions, general anaesthesia was administered, and the patient was positioned in lithotomy, cleaned, and draped. An inverted "Y" incision was made in the perineum and deepened to the urethra. A urethrotomy was performed, and the calculus was extracted. Buccal mucosa was harvested and used for the ventral-onlay substitutive urethroplasty, performed over a size 18F catheter. Haemostasis was secured, a Penrose drain was inserted, the perineum was closed in layers, and a sterile dressing was applied. Post-operative recovery was satisfactory. The wound healed well despite a brief (three days) episode of purulent discharge engendered by bacterial seeding from the urethral stone. This was resolved with daily wound dressing with normal saline.

The urethral catheter was removed after six weeks following a satisfactory peri-catheter urethrogram (Figure 4, Figure 5), and the patient has been voiding normally since then, with a normal peak flow rate (20 ml/s) on uroflowmetry. The suprapubic catheter was removed two weeks later, and the fistula tract closed. The patient has since resumed his full duties and activities of daily living, including satisfactory sexual activity.

Alternative approaches, such as endoscopic stone retrieval and laser lithotripsy, were considered but were not available due to the limited resources in the setting. In well-equipped centres, these minimally invasive techniques could have been preferred over open urethrolithotomy. However, given the presence of an associated stricture, the decision to perform open surgery with buccal mucosal grafting was deemed most appropriate.

Follow-up and outcome of interventions: the retrieved urethral stone was sent to the laboratory for chemical analysis. The chemical analysis revealed the following composition: 10% calcium oxalate monohydrate (Whewellite), 80% calcium oxalate dihydrate (Weddellite), and 10% uric acid. Serum magnesium, calcium, uric acid, and serum parathyroid hormones were all normal. Urine pH and specific gravities were both within normal.

Based on these results (and to avoid future stone recurrence from any causes, including migratory proximal stones), we advised the client to maintain a high fluid intake of 2.5 to 3 liters per day to dilute urine and reduce stone formation. We recommended dietary modifications, including reducing high-oxalate foods such as spinach, rhubarb, nuts, and tea; ensuring optimal dietary calcium (1000-1200 mg/day); limiting sodium intake to less than 2300 mg/day; and reducing animal protein consumption from red meat, poultry, and fish. We encouraged him to maintain a healthy weight and engage in regular physical activity. We emphasized the importance of regular follow-ups with us at the outpatient department, with laboratory tests including urine tests and imaging studies, to monitor progress and adjust the treatment plan as needed. Finally, we educated him on adhering to dietary and medication recommendations. We aimed for a urine output of at least 2.5 Liters per day to effectively manage and further prevent future stone formation.

Patient perspective: the patient expressed satisfaction with the treatment received and the overall recovery process. He acknowledged the importance of adhering to the dietary and medication recommendations to prevent recurrence and manage his condition long-term. He has resumed his daily activities without significant limitations and is happy with the outcome of his treatment.

Informed consent: the patient provided written informed consent for both the surgical procedure and the publication of his case report.

Discussion     

Urethral calculi are rare, constituting only 0.3% of all urinary stones, with a higher incidence in men due to anatomical differences [3,4]. These stones can be primary, linked to urethral abnormalities like strictures or diverticula, or secondary, migrating from the upper urinary tract [2,5]. Primary stones are associated with urinary stasis and infection in areas of obstruction [6]. The posterior urethra is affected in 88% of cases, with symptoms including acute urinary retention, dysuria, haematuria, and severe perineal pain [3,6,7]. Diagnosis involves clinical evaluation and imaging, such as retrograde urethrography, to identify the stone's location and any associated pathology [3,8]. Treatment depends on the stone's size and location, ranging from non-invasive manipulation to surgical interventions like urethrotomy or substitutive urethroplasty [5,9]. Complications include infection, urethral injury, and recurrence, emphasizing the need for prompt treatment and long-term follow-up [7,9]. Table 1 summarises pertinent management of urethral stones in existing literature.

As demonstrated by the index case, the management of urethral calculi requires prompt, accurate diagnosis and initial management, followed by definitive treatment tailored to the individual case. The choice of definitive management depends on factors such as stone location, associated pathologies, available equipment, and the surgeon´s skill level or preferences [4]. In this case, the patient presented with haematuria, dysuria, and worsening lower urinary tract symptoms culminating in acute urinary retention, consistent with typical presentations of urethral calculi, especially those originating from the bladder [6]. The inability to milk the stone down or up the urethra was due to its location and the associated risk of urethral injury [8]. Options like retrograde manipulation back into the bladder with subsequent lithotripsy were not feasible due to the lack of resources and the associated stricture distal to the stone.

Initial management involved relieving the acute retention and addressing the infection, while definitive management focused on extracting the stone and repairing the associated urethral stricture. The chosen surgical approach-substitutive urethroplasty using a buccal mucosa graft-proved effective for the 4.0 cm long urethrotomy wound that resulted. This technique is well-documented in the literature for managing complex urethral strictures and provides a durable and well-vascularized tissue for urethral reconstruction [10]. In terms of surgical management, substitutive urethroplasty with buccal mucosa graft is considered the gold standard for treating long-segment and complex urethral strictures [7,10]. This technique involves harvesting a graft from the buccal mucosa and using it to replace the diseased segment of the urethra. It has a high success rate and is associated with fewer complications compared to other forms of urethroplasty. Postoperative care is crucial, including catheter management, infection control, and monitoring for complications such as stricture recurrence or fistula formation [9,10]. Regular follow-ups are essential to monitor the patient´s progress and prevent stone recurrence, given the high likelihood of stone formation in patients with a history of urolithiasis [8]. The recurrence rate of urethral calculi after surgical intervention is low, particularly when underlying conditions like strictures are addressed.

Limitations of this report include the fact that it is a single case, and therefore, its findings may not be universally applicable to all patients with urethral stones. Additionally, the lack of advanced endoscopic equipment limited our choice of minimally invasive treatment options. Future research should focus on identifying optimal, cost-effective interventions for managing urethral calculi in resource-constrained environments.

Conclusion     

The case report underscores the importance of considering urethral calculi, associated with a stricture, in the differential diagnosis of young males presenting with acute urinary retention and haematuria. This case also reinforces the necessity of a structured diagnostic approach, which can help reduce delays in management and improve outcomes. It emphasizes the significance of prompt diagnosis and appropriate management, which includes prompt relief of obstruction and treatment of infection, followed by (interval) definitive surgical management and post-operative care. Additionally, the recommendation for regular follow-up and lifestyle modifications to prevent stone recurrence is both relevant and crucial for long-term patient care. We acknowledge that this is a single case report and that findings may not be generalizable.

Competing interests     

The authors declare no competing interests.

Authors' contributions     

Frank Obeng: conceptualization, methodology, and writing - whole manuscript original draft preparation; Aishah Fadila Adamu: data collection, writing - review and editing; Samuel Edudzi Gavor and Blessings Yao Setsoafia: data collection, supervision, and writing of manuscript; Ali Mamudu Ayamba: supervision, methodology, writing - review and editing. All the authors read and approved the final version of this manuscript.

Tables and Figures     

Table 1: a review of literature on urethral stones requiring open surgery

Figure 1: ultrasound scan showing the urethral stone

Figure 2: urethrogram, control film: arrows depict the stone

Figure 3: urethrogram study: white arrows depict stone, red arrows depict a stricture

Figure 4: micturiting cystourethrogram; red arrow points to the site of the urethral stone

Figure 5: pericatheter urethrogram; depicts healed urethroplasty with no contrast extravasation

References