The study was conducted at the University Clinic of Urology-Andrology of the Hubert Koutoukou Maga National University Hospital in Cotonou.

This was a retrospective, cross-sectional study, with a descriptive and analytical aim of examining the epidemiological, diagnostic, therapeutic, and prognostic aspects of urethral strictures at the CUUA of the CNHU-HKM in Cotonou from 2012 to 2023. We conducted an exhaustive recruitment of cases received during the study period whose medical records were usable, including data relating to the parameters studied: epidemiological (age, sex, occupation, marital status, and socioeconomic level), diagnostic (clinical signs, paraclinical signs, etiological diagnosis), therapeutic (surgical technique, post-operative results, patient satisfaction), and prognostic (recurrence, sequelae, and secondary complications). The term recurrence designates a new urethral stricture occurring after initial healing.

The collected data were entered and analyzed using EPI INFO version 7.2 software. Results were entered as text in WORD software, and graphs were generated using EXCEL software.

From an ethical perspective, the identities of the patients included in the study remained confidential, research authorization was granted by the relevant hospital administrative department and informed consent from patients was obtained by phone call.

Year of Admission: Table 1 shows the distribution of patients by year of admission. Over the 12 years, 119 cases of stricture were retained out of the 177 recorded, representing an annual incidence of 9.91 cases per year. Depending on the year, the prevalence of urethral strictures was higher in 2012, 2014, 2018, and 2020.

Patient Age: The mean age of patients was 47.5 years, ranging from 7 to 88 years. Table 2 shows the distribution of patients by age group. The most affected age groups were 20 to 35 years and 35 to 50 years, with a percentage of 25.21%, or 30 patients.

Patient Sex: The study included a total of one hundred and seventeen (117) men and two (2) women. A male predominance of 98.31% and a sex ratio of 58.5 men to one (1) affected woman.

Patient Marital Status: Table 3 groups patients according to marital status. The majority of patients were in a relationship (51.26%).

Patient Occupation: Figure 1 shows the distribution of patients by occupation. The most represented occupations were civil servants (16.81%) and artisans and manual workers (16.81%).

Patient Education Level: Figure 2 groups patients by education level. The majority of patients were educated, with 43.85% having at least a secondary education.

Patient Medical History: Figure 3 shows the distribution of patients by medical history. Urethral stricture was the most frequently encountered medical history (18.49%), followed by hypertension (16.81%), urethritis, and pelvic trauma in the same proportions (13.45%).

Patient Surgical History: Figure 4 shows the distribution of patients according to their surgical history. Surgical history was dominated by cystostomy (18.49%), abdominal surgery (11.76%), prostate surgery (10.08%), and urethroplasty (8.40%).

Functional Signs: Figure 5 shows the distribution of patients according to the functional signs that prompted the consultation. Dysuria was the dominant functional sign (68.07%), followed by complete bladder retention of urine (40.34%) and weak stream (32.77%).

Physical Signs

General Condition of Patients: Table 4 groups the patients according to their general condition. The majority of patients were in good general condition (83.19%).

Void Status at Admission: Table 5 shows the distribution of patients according to their voiding status at admission. 57.98% had dysuric urination, and 36.13% already had a cystostomy catheter.

Digital Rectal Examination: Table 6 groups the male subjects according to the results of the digital rectal examination. The digital rectal examination revealed a benign-appearing pathological prostate in 19.66% of the male subjects.

Clinical Signs: Figure 6 shows the distribution of patients according to clinical signs. The admission examination revealed signs of infectious complications in 12.61% of patients.

Imaging

Type of Imaging: Retrograde and micturition urethrocystography was the most commonly used paraclinical examination for diagnosis (75.63%), followed by cystoscopy to a lesser extent (4.20%). An intraoperative diagnosis of urethral stricture was made in 2.32% of patients. Cases of meatal stricture did not require imaging.

Topographic Diagnosis: Table 7 groups the patients according to the site of the stricture. 56.66% of strictures were found in the anterior urethra, with a high prevalence in the bulbar segment and the bulbo-penile junction.

Biology

Patient Urine Culture Results: The urine culture was positive in 24.36% of patients. It identified certain organisms listed in the table below.

Germs Isolated in Urine Culture: Table 8 groups the patients according to the organisms isolated in the cytobacteriological examination of the urine. The most frequently isolated organisms were E. coli (37.93%) and K. pneumoniae (24.13%).

Impact on the Upper Urinary Tract: Figure 7 shows the distribution of patients according to the glomerular filtration rate value calculated using the simplified MDRD formula. 10.20% of patients had end-stage renal disease.

Etiologies: Table 9 groups patients according to the cause of stricture. It was infectious in 57.98% of cases and traumatic in 26.05% of cases. The types of trauma are listed in Table 10 .

The traumatic origin was dominated by post-trauma pelvic trauma (66.74%). The iatrogenic origin of urethral strictures is listed in Table 11 . The iatrogenic origin was dominated by traumatic catheterization.

Complications: Figure 8 shows the distribution of patients according to complications secondary to urethral strictures. Complications associated with urethral strictures were found in 39.50% of patients. These complications were dominated by recurrences, urethrocutaneous fistulas (8.40%), renal failure (7.56%), and urinary tract infections, such as acute pyelonephritis.

Therapeutic Indications

Table 12 groups patients according to therapeutic indication. Endoscopic internal urethrotomy was the most commonly used treatment (31.93%), followed by anastomotic urethroplasty (29.41%).

Post-operative Urethral Dilation: Table 13 shows the distribution of patients according to the number of post-operative dilation sessions. The vast majority of patients (86.55%) did not undergo adjuvant dilation.

Therapeutic Outcomes

Void Status at End of Hospitalization: Table 14 groups patients according to their voiding status at the end of hospitalization. After treatment, 33.61% of patients had normal urination at hospital discharge. Furthermore, 38.66% were discharged with a urethrovesical catheter and scheduled for removal.

Therapeutic Outcomes: Table 15 shows the distribution of patients according to normal voiding status at hospital discharge, based on the therapeutic indication. Favorable outcomes, characterized by comfortable voiding, were found at the end of hospitalization in 30% of patients who underwent anastomotic urethroplasty.

Length of Hospitalization: Table 16 groups patients according to the length of hospitalization in weeks. A hospital stay of less than two weeks was observed in 52.1% of patients. The average length of hospitalization was 19.11 days, with a range from 1 to 280 days.

Time to Catheter Removal: The average time to catheter removal was 18.56 days, with a range from 3 to 56 days.

Discharge Method: Table 17 shows the method of patient discharge. The vast majority of cases (96.63%) returned home.

Lost to Follow-up: After their hospitalization, 41.18%, or 49 patients, were lost to follow-up because they did not attend the follow-up or could not be contacted during this study. This was due to the lack of a functional number.

Recurrences: 16.80% of patients experienced a first recurrence of urethral stricture after 12.61 months, requiring a change in treatment in 66.67% of cases.

Post-operative Complications: Figure 9 shows the distribution of patients according to post-operative complications. Late post-operative complications were dominated by erectile dysfunction.

Current Patient Status: Figure 10 shows the distribution of patients according to their current status. Currently, 5.88% still have a cystostomy catheter, and 28.57% of patients contacted by phone still have normal and comfortable urination.

Relationship between therapeutic choice and recurrence: Table 18 shows the distribution of patients according to the occurrence of recurrence based on therapeutic choice. There was no statistically significant association between therapeutic choice and recurrence (p-value = 0.13). However, of the 6 cases of first-stage urethroplasty performed, 50% were complicated by recurrence. Of the 12 cases that underwent dilation, 25% experienced recurrence. Of the 35 cases that underwent anastomotic urethroplasty, 20% experienced recurrence. Only 15.79% of endoscopic internal urethrotomies were complicated by recurrence. There were no cases of recurrence in patients who underwent 2-stage urethroplasty.

Relationship between Site and Recurrence: Table 19 shows the distribution of patients according to the site of the urethral stricture and the occurrence of recurrence. There was no statistically significant association between the site of the first stricture and the occurrence of recurrence (p-value = 0.1359). However, recurrences were observed in 6/20 patients with stricture at the membranous urethra.

119 cases of stricture were identified out of the 177 identified, representing an annual incidence of 9.91 cases per year. This frequency is lower than the actual frequency, as the rate of rejected and unretrievable cases was 32.77%.

Age and Sex: In the present study, the mean age of patients was 47.5 years, ranging from 7 to 88 years. The most affected age groups were 20 to 35 years and 35 to 50 years, with a percentage of 25.21%. This result is superimposable to that of Hounnasso et al. in Benin, who found, in a study on the epidemiological and diagnostic aspects of male urethral stricture in the same department in 2015, a mean age of 44.4 ± 12.7 years with extremes of 10 years and 85 years [2] .

Kaboré et al., who report that the mean age of patients was 44.4 ± 16.8 years [Min 8, Max 80] [3] . Sikpa et al. in 2016 also found a mean age of 44.79 ± 15 years (18 and 77 years) in Togo [4] . The same is true for Guena et al. in 2019 in Cameroon [5] . Coulibaly et al., in a study carried out in Mali in 2018 on the management of urethral strictures in men in the urology department of Gabriel Toure University Hospital, found similar results with a mean age of 43.06 years, with extremes of 06 and 65 years [6] . These results from the literature allow us to conclude that urethral stricture is a pathology of young adults. Furthermore, the study included a total of one hundred and seventeen (117) men and two (2) women; a male predominance of 98.31%. The higher frequency of urethral strictures in male subjects is not surprising. It is thought to be related to the fact that the male urethra is 4 to 5 times longer than the female urethra; therefore, a stricture along its course is more likely to occur. Furthermore, the consistently high incidence of sexually transmitted infections, associated with the anatomical layout of male subjects, where the urinary and genital tracts are intertwined, could explain the high predisposition of male subjects to developing this pathology.

Occupation and Education Level: The most common occupations were civil servants (16.81%) and artisans and manual workers (16.81%). The majority of patients were educated; 43.85% had at least a secondary education. The high frequency of civil servants is related to the availability of state-provided health insurance for this patient group. Furthermore, educated patients better understand the need for immediate access to modern healthcare. Uneducated patients often have a more complex healthcare pathway and only come to the hospital after visiting traditional healers and peripheral health centers.

Medical and Surgical History: Urethral stricture was the most frequently encountered medical history (18.49%), followed by hypertension (16.81%), urethritis, and pelvic trauma in the same proportion (13.45%). Surgical history was dominated by cystostomy (18.49%), abdominal surgery (11.76%), prostate surgery (10.08%), and urethroplasty (8.40%). The high frequency of these pathologies is linked firstly to the fact that stricture is a recurring pathology and then there is a high proportion of patients over 50 years old (44.74%), and therefore at risk of cardiovascular pathology.

Functional Signs: Functional signs were dominated by lower urinary tract disorders, with dysuria being the dominant functional sign (68.07%), followed by complete bladder retention (40.34%) and weak urinary stream (32.77%). Most African authors agree with us on this point and report that dysuria is the main functional sign. Hounnasso et al. reported in 2015 that dysuria (48.1%) and complete bladder retention (35.9%) were the main reasons for consultation [2] . Coulibaly et al. found similar results in 2018: dysuria (51.2%) and acute urinary retention (25.6%) were the most common reasons for consultation [6] .

Physical Signs: The physical examination in our series found a benign-appearing pathological prostate in 18.75% of patients, a good general condition in 83.33% of patients, and 37.84% already had a cystostomy catheter. This is explained by the fact that urethral catheterization for complete bladder retention in urethral strictures often ends in failure, indicating a urinary diversion to relieve these patients who have the urge to urinate, who want to urinate at all costs, but are unable to.

Paraclinical Signs

Imaging: Retrograde and micturition urethrocystography was the most commonly used paraclinical examination for the diagnosis of urethral strictures in this series (75.63%). Cystoscopy was performed in only 4.20% of patients. An intraoperative diagnosis of stricture was made in 2.32% of patients. Cases of meatal strictures did not require imaging. This result is similar to that of Hounnasso et al., who found a frequency of 87.73% for UCRM in 2015 in the same department [2] . Guena et al., in 2019 in Cameroon, reached the same result [5] . Halidou et al. made the same observation [1] . Indeed, they report that “uretrocystography was the main complementary examination for the diagnosis; it made it possible to discover 63.79% of stenosis at the bulbar level. Our rate is close to those of Sikpa et al. and Ndour et al., with 67.6% and 67.8%, respectively” [4] .

These data from the literature allow us to conclude that retrograde uretrocystography is the first-line examination in the diagnosis of urethral strictures [7] - [18] . This is explained by the fact that retrograde urethrocystography allows for the precise determination of the location and length of the urethral stricture, which is of capital importance for management. However, some authors, based on several factors, including the accuracy of cystoscopy, as well as its great accessibility, lower cost, the familiarity of urologists with this technique, and the lower exposure to radiation, suggest using cystoscopy rather than urethrography for the initial diagnosis of urethral stricture [13] - [16] . These authors agree with Ouattara et al., who, in a study conducted on the contribution of rigid cystoscopy to the diagnosis of lower urinary tract abnormalities and pathologies in Cotonou, concluded that urethrocystoscopy could be of invaluable value in the diagnosis of urological conditions and anomalies of the lower urinary tract in our context [12] .

Biology: The urine culture was positive in 24.36% of patients. The most frequently isolated germs were E. coli (37.93%) and K. pneumoniae (24.13%). This result is superimposable with that of Halidou et al. in Niger in 2020, who reported: “The bacteriological examination of urine made it possible to isolate E. coli in 37.06%, Klebsiella pneumoniae in 14.65%, Staphylococcus aureus in 8.62%, and P. mirabilis in 2.58%” [1] . In a 2015 study on obstructive renal failure (epidemiological and diagnostic aspects) involving 51 cases at the Cotonou National Hospital Center (CNHU), Natchagandé et al. reported that urethral stricture was the third most common cause of renal failure after prostate disease [8] .

Topographical Diagnosis: 56.66% of strictures were found in the anterior urethra, with a high incidence in the bulbar segment and the bulbo-penile junction. The same observation was made in Benin in 2015 by Hounnasso et al., who found that the stricture was located only in the anterior urethra in 73.6% of cases, with the bulbo-perineal urethra (63.2%) as the elective site [2] . Ndour et al. also reported in a 2018 study that the preferred site of stenosis is the anterior segment in 82.4% of cases, and the bulbar portion is the most affected [10] . Ouattara et al. in 2023 reached the same result [12] . This is also the case of Mouss et al. in Congo, who found 71% strictures at the level of the bulbar urethra [14] . This could be linked to the dimensions of the anterior urethra, whose length represents three times that of other segments in men. Therefore, a shrinkage would be more likely to occur in this segment compared to the others.

Etiological Diagnosis: In this series, the cause was infectious in 57.98% of cases, traumatic in 26.05% of cases, and iatrogenic (15.97%). This result is similar to that of Sikpa et al. in 2016 in Togo, where the etiology of urethral stricture was infectious in 55.9% of cases [4] . This is also the case for Ngaroua et al., who reached the same conclusion [16] .

Conversely, Abidi et al. in Pakistan in 2023 identified, firstly, traumatic causes (road accidents) (90.8%), followed by iatrogenic causes (post-transurethral resection of the prostate or post-prostatectomy stenosis), as the main etiologies of posterior urethral strictures. Infectious causes represent only 6.9% of cases.

The similarity of the results of the present study with those of African authors on the one hand, and the discordance with results from Europe and Asia on the other, suggests that the etiology of urethral stricture varies from one region to another [15] [17] .

This difference in etiology between regions could be explained by the consistently high prevalence in our context of sexually transmitted infections due to unsavory sexual behaviors (multiple sexual partnerships), especially among young adults, who constitute the majority of the target population. Added to this, in our context, is the lack of management of infectious diseases that cause strictures, due to increasingly frequent resistance to antibiotics or poor therapeutic orientation.

Endoscopic internal urethrotomy was the most commonly used therapeutic method (31.93%), followed by anastomotic urethroplasty (29.41%), and then dilation with a frequency of 10.52%. Ngaroua et al. in Cameroon in 2017 reached the same conclusion, with slightly higher proportions regarding the use of UIE in more than 58% of cases for the treatment of urethral strictures [16] . In their series, Kaboré et al. identified skin flap urethroplasty and end-to-end anastomosis resection (ETAR) as the most commonly used treatments (58% of cases) [3] . This result is different from that of Coulibaly et al., who reported in 2018 in Mali that “treatment was done by urethroplasty in 72.1% and by Beniqué dilation in 25.6%, endoscopic internal urethrotomy was not used” [6] .

In our patients, several reasons would explain these therapeutic choices: on the one hand, the mastery of endoscopic practices and the fact that endoscopic treatment is accompanied by a short post-operative period with almost no surgical scar and considerably reduced long hospital stay. Data from the literature agree on the fact that urethroplasty resection anastomosis is the first-line treatment based on the benefit in terms of long-term costs (less reintervention) and the negligible impact on erectile function.

16.80% of patients experienced a first recurrence of urethral stricture after 12.6 months, requiring a change in treatment in 66.67% of cases. These literature data thus support the results of this series regarding the recurrent nature of this pathology. These recurrences of urethral stricture, even after adequate management, could be linked to the formation of scar tissue, thus leading to recurrences [14] - [17] .

Post-operative Results

Normal urination was observed at hospital discharge in 33.61%, or 40 patients. Patients who underwent anastomotic urethroplasty constituted the largest proportion of this group, with a good outcome rate of 30%. However, a few cases of late post-operative complications were reported. These mainly involved erectile and ejaculatory dysfunction.

Literature data show higher success rates for anastomotic urethroplasty [4] . This is the case with Feddal et al., with 69% satisfactory results [17] .

Regarding complications. The erectile dysfunction reported in most of the literature could be related to the risk of intraoperative incidents such as damage to the nerves or blood vessels essential for erection [18] . Furthermore, surgery can disrupt the physiological mechanisms involved in erection, such as nerve control, penile arterial vascularization, and endothelial function. This, combined with risk factors such as diabetes, cardiovascular disease, smoking, depression, psychological disorders, and post-operative stress, increases the likelihood of erectile dysfunction after urethral surgery.