Introduction

Urethral stricture is chronic fibrosis and narrowing of urethral lumen caused by acute injury, inflammatory conditions and iatrogenic interventions including urethral instrumentation or surgery. The morbidity of male urethral stricture arises from urinary tract obstruction including lower urinary tract symptoms (LUTS), recurrent urinary tract infection, bladder dysfunction and more rarely kidney damage. Treatment of urethral stricture aims to eliminate obstruction and LUTS [1].

Recent studies support the widespread use of urethroplasty over repeated visual internal urethrotomy as a treatment for anterior urethral stricture disease, not only because of the high failure rate of endoscopic management but also the coast-effectiveness of urethroplasty as a definitive repair makes it a more attractive option for this recurrent problem [2].

Graft urethroplasty is an established treatment option for strictures at the penile and bulbar urethra not amenable to anastomotic repair. Currently buccal mucosal graft is generally accepted as the graft of choice. The use of buccal mucosal graft for urethroplasty was first reported in 1894. Although buccal mucosal graft is easy to harvest, early and late donor site complications (local pain, oral tightness, sensitivity disorders, salivary changes) has been reported [3].

Lateral and ventral surface of the tongue mucosa has histological features identical to the rest of the mucosal cavity. With the hope of reducing donor site morbidity in 2006 Simonato et al first described the use of lingual mucosal graft in urethroplasty. Initial series reported low local morbidity associated with lingual mucosal graft use but these series lacked a comparison with buccal mucosal graft [4]. Consequently, this study was conducted to predict severe preeclampsia in patients with mild preeclampsia by measuring serum testosterone levels (serum total and free testosterone) and sex hormone binding globulin.

Patients and Methods

After ethical committee approval and written consents from the patients, this is a case control comparative study, was carried out at Ain Shams university hospital. All cases were selected from those attending the urology outpatient clinic presenting with lower urinary tract symptoms secondary to stricture anterior urethra and prepared for surgical management by urethroplasty with dorsal onlay technique.

Exclusion criteria: History of oral surgery, Visible oral mucosal diseases or changes, Patients with restricted mouth opening, Tongue tie (decreased motility of tongue tip due to short frenulum), Patients with neurological lesions causing neuropathic disorders as neurogenic bladder and atonic bladder and Patients with short urethral stricture (<2 cm) or cases with posterior stricture urethra.

Study Procedures: All participants were submitted to the following:

— Careful history taking regarding personal, medical and surgical histories.

— Complete physical examination to exclude any disorders may interfere with the results including hip mobility, perineal area and careful assessment of oral and lingual mucosa.

— Preoperative radiological investigations including:

1. Uroflowmetry and AUA symptom score.

2. Abdominopelvic ultrasound with pre- and post-void residual urine.

3. Retrograde urethrography with complementary voiding cystourethrography.

4. Cystourethroscopy.

— Preoperative laboratory investigations including, Hemoglobin, kidney function tests and urine culture and sensitivity.

— Steps of intervention for both groups:

1. Estimation of operative time, intraoperative complications.

2. Early post-operative complications, catheter time, hospital stay.

— Post-operative follows up includes:

1. Follow up of surgical outcome:

— Using retrograde cystourethrography at following intervals:

— Peri-catheter urethrogram 3 weeks post-operative to evaluate healing of urethra and at 3- and 6-months post-operative to check patency.

— Follow up by uroflowmetry and AUA symptom score at 3 months post-operative. Failure is defined as stricture recurrence or fistula with the need for further urethral manipulation [1].

2. Follow up of donor site morbidity:

— At postoperative day 3 pain at the oral cavity was assessed by the numeric rating scale 0 (no pain) to 10 (worst possible pain) and by the need for analgesia for oral pain and by visual analog scale for pain.

— Oral morbidity was further assessed by an in-home questionnaire assessing drinking and eating problems (“no problem,” “slightly difficult,” “very difficult,” “impossible”), and by YES/NO questions evaluating speech impairment, sensitivity disorders and dysgeusia.

— Two weeks and 6 months postoperatively oral pain were assessed by numeric rating scale (NRS), and oral morbidity was assessed by YES/NO questions on problems with drinking, eating soft and solid food, on oral tightness, sensitivity disorders, salivary changes, speech impairment and dysgeusia.

Sample Size: The required sample size has been calculated using the Power Analysis and Sample Size Software (PASS) version 11 (NCSS, LLC. Kaysville, Utah, USA). The test statistic used is the grouping T- test with pooled variance and significance of the test is targeted at the0.05 level (confidence level, 95%).

Ethical Considerations: The patient data were anonymous. Data presentation was not be by the patient’s name but by diagnosis and patient confidentiality was protected. An informed consent was taken from all participants, it was in Arabic language and confirmed by date and time. confidentiality was preserved by assigning a number to patients initials and only the investigator knew it Statistical analysis: Analysis is to be performed using SPSS for windows v20.0, Data to be presented in terms of range, mean and standard deviation (for numeric parametric variables); range, median and inter-quartile range (for numeric non-parametric variables); or number and percentage (for categorical variables). Difference between two independent groups is to be analyzed using independent student’s t-test as well as the mean difference and its 95% CI (for numeric parametric variables); or chi-squared test as well as the risk ratio and its 95% CI (for categorical variables). Binary logistic regression analysis is to be performed for estimating the association between good/poor response and the measured variables ROC curves are to be constructed for estimating the validity of measured variables as predictors of good or poor response validity is to be presented in terms of sensitivity, specificity, positive and negative predictive values and their corresponding 95% Cis significance level is set at 0.05.

Results

Table 1 shows no statistically significant difference between the studied groups regarding age, smoking, comorbidities, associated urinary condition and having urinary catheter.

Table 1. Demographic characteristics between the studied groups

Table 2 shows no statistically significant difference between the studied groups regarding stricture, graft and operation characteristics.

Table 2. Stricture, graft and operation characteristics between the studied groups

Table 3 shows no statistically significant difference between the studied groups regarding general and urethral outcomes.

Table 3. General and urethral outcomes between the studied groups

Discussion

Urethroplasty techniques are continuously improving with advancements in the field of substitution urethroplasty. The ventrolateral aspect of the tongue offers mucosal tracts that are up to 7—8 cm long, depending on the tongue dimensions and has constant availability. Buccal mucosa and lingual mucosa have the same embryologic origin, are easy to harvest, have favorable immunologic properties (resistance to infection) and tissue characteristics (thick epithelium, high content of elastic fibers, thin lamina propria, and rich vascularization) that are favorable properties for imbibitions, inosculation, and revascularization of the graft [5].

Consequently, this study was conducted and aimed to compare between the use of buccal mucosal graft and lingual mucosal graft in management of anterior urethral stricture with evaluation of surgical outcome and donor site morbidity.

During this study, 73 patients were assessed for eligibility and 60 patients were included in the study (30 in each group). Of all eligible patients, 9 patients were excluded from the study based on the inclusion criteria and 3 patients refused to participate in of the study. Ultimately, the analysis was based on the data of 60 patients who presented with lower urinary tract symptoms due to anterior urethral stricture.

The study was conducted as a case-control study at Ain Shams University Hospital, focusing on patients who presented with lower urinary tract symptoms due to anterior urethral stricture. The patients underwent urethroplasty using the dorsal onlay technique. Specific exclusion criteria were established, such as a history of oral surgery, oral mucosal diseases, and restricted mouth opening.

The study results provide a comprehensive comparison between buccal mucosal grafts (BMG) and lingual mucosal grafts (LMG) for the surgical management of anterior urethral stricture.

Regarding Success Rate of Urethroplasty, in our study, there was no significant difference between BMG and LMG regarding the overall urethral success rates, with failure rates of 13.3% in the BMG group and 6.7% in the LMG group and both grafts showed comparable effectiveness. The variables analyzed, such as stricture length, graft dimensions, and stricture location, did not exhibit any significant differences between the BMG and LMG groups. The average stricture length was slightly shorter in the BMG group (7.6 cm) compared to the LMG group (8.3 cm), but this difference was not statistically significant. Similarly, graft length and width were nearly identical across both groups, with no notable differences in the surgical techniques employed, such as the choice of one-step versus two-step urethroplasty. These results suggest that, technically, either graft can be used with similar success rates in terms of repairing the urethral stricture.

Across all studies, both buccal mucosal graft (BMG) and lingual mucosal graft (LMG) yielded similar success rates in urethroplasty, with no significant statistical differences. In Lumen et al. [6], the success rate for LMG was 89.7%, while BMG achieved 82.8%, showing only a minor difference. Al Mamun et al. (1) reported success rates of 80% for LMG and 75% for BMG, again without significant differences. In Pal et al. [7], the rates were similarly high, with 86% for BMG and 83% for LMG. These findings align with Chauhan et al. [8], who found a slightly higher success rate for LMG at 80%, compared to 69.2% for BMG, although this difference was not statistically significant.

Regarding Urinary Flow (Qmax) Improvement, our study observed a mean postoperative Qmax of 16.4±6.4 ml/s in the BMG group and 18.3±6.5 ml/s in the LMG group. This slight improvement in the LMG group was not statistically significant, which aligns with the results from Pal et al. [7] and Kumar et al. [9]. Both studies showed significant improvements in Qmax for both groups postoperatively but did not report significant differences between them. For instance, Pal et al. [7] reported Qmax improvements from 8.6 ml/min to 29.56 ml/min for BMG and from 7.43 ml/min to 30.29 ml/min for LMG. These findings indicate that both grafts result in significant improvements in urinary flow, with no clear advantage for either.

Regarding donor site morbidity, our study highlighted fewer complications at the donor site in the LMG group. LMG patients experienced fewer issues with drinking, eating soft and solid food, and overall oral functionality. For example, problems with drinking were reported in 10% of LMG patients and 36.7% of BMG patients by day 3. These results are in agreement with other studies. Lumen et al. [6] reported similar outcomes, noting fewer long-term donor-site complications in LMG, though early complications like speech impairment and dysgeusia were more frequent with LMG. Kumar et al. [9] and Chauhan et al. [8] also found that LMG patients had fewer long-term complications, such as scarring, tightness of the mouth, and salivatory disturbances. Overall, LMG consistently demonstrates fewer long-term complications, making it a preferable option in terms of donor-site morbidity.

Regarding Speech and Oral Functionality, our study found that speech and oral functionality were more impaired in LMG patients in the early postoperative phase, particularly at day 3 and week 2. At day 3, 86.7% of LMG patients reported speech problems, compared to only 33.3% of BMG patients. By week 2, these numbers had improved, but 53.3% of LMG patients still experienced issues, compared to 20% in the BMG group. This aligns with the findings of Lumen et al. [6], who reported that 93.1% of LMG patients had speech impairment at day 3, compared to 55.2% of BMG patients. Dysgeusia (taste disturbance) was also more common in LMG patients in our study, with 63.3% affected at day 3, compared to only 13.3% of BMG patients. These results are mirrored in Lumen et al.’s study, where dysgeusia affected 48.3% of LMG patients versus 13.8% of BMG patients. However, by six months, most patients in both groups had recovered, and long-term differences were minimal. Overall, while LMG is associated with more early postoperative speech and taste disturbances, these complications generally resolve over time.

Regarding Pain and Sensitivity Disorders, Pain and sensitivity disorders at the donor site are important factors in evaluating the recovery process. In our study, oral tightness and sensitivity disorders were significantly more common in the BMG group. At month 6, 26.7% of BMG patients still reported oral tightness, compared to only 6.7% of LMG patients. This aligns with findings from Lumen et al. [8], who reported a higher prevalence of long-term sensitivity disorders in BMG patients (44.8%) compared to LMG patients (31%). Kumar et al. [9] also observed higher rates of long-term complications like perioral numbness and persistent pain in BMG patients. These results suggest that, while both grafts cause some level of postoperative discomfort, LMG is associated with a quicker recovery and fewer long-term complications related to sensitivity and oral tightness.

In terms of stricture recurrence, our study found a recurrence rate of 13.3% for BMG and 6.7% for LMG, with no significant difference between the two groups. These results are comparable to those from Kumar et al. [9] and Pal et al. [7], both of which reported low recurrence rates (7—10%) for both graft types. Similarly, Lumen et al. [6] found no significant difference in recurrence between BMG and LMG, with overall recurrence rates around 10—15%. This suggests that both graft types are equally effective in maintaining urethral patency long-term, with low recurrence rates.

In comparison with the broader body of research, our study’s findings are largely consistent with those reported in the literature. Both BMG and LMG are effective for managing anterior urethral stricture, with similar success rates and improvements in urinary flow. However, LMG tends to result in fewer long-term donor-site complications, making it a preferable choice for patients concerned about oral morbidity. While LMG may present more short-term complications related to speech and dysgeusia, these issues typically resolve by the six-month mark. Overall, LMG offers a slightly better profile in terms of donor-site morbidity, while both grafts are equally effective for urethral reconstruction.

Clinical Implications

The findings of this study have significant clinical implications for surgeons performing urethroplasty for anterior urethral strictures. The choice between BMG and LMG should not only be based on the technical feasibility of the graft but also on the expected donor site morbidity. For patients where early oral function is critical, BMG may be the preferred choice to minimize complications with drinking, eating, and speaking. However, LMG might be suitable for patients who can tolerate short-term oral complications but wish to avoid long-term issues like oral tightness. This tailored approach could improve patient outcomes and satisfaction by aligning surgical decisions with individual patient needs and preferences.

Strength points of the study:

One of the main strengths of the study is its prospective, case-control design, which allows for a direct comparison between two commonly used mucosal grafts for urethral stricture repair. The study also carefully controlled for confounding factors by ensuring similar baseline characteristics between the two groups, making the results more robust and reliable. Additionally, the study provides a comprehensive analysis of both surgical outcomes and donor site morbidity, offering a balanced view of the benefits and drawbacks of each graft type.

Limitations

The study has several limitations that should be considered when interpreting the results. First, the sample size was relatively small, with only 30 patients in each group, which may limit the generalizability of the findings. Additionally, the follow-up period was limited to six months, which may not capture the full range of long-term complications or stricture recurrence rates. Moreover, the study did not include patient-reported outcomes regarding quality of life, which could provide a more holistic view of the impact of donor site morbidity. Lastly, the exclusion of certain patient populations, such as those with oral diseases or neurological disorders, may limit the applicability of the findings to broader clinical settings.

Conclusion

The study concluded that both buccal mucosal graft (BMG) and lingual mucosal graft (LMG) are effective options for the surgical management of anterior urethral strictures. The surgical outcomes, including graft success, stricture recurrence, and urethral function, were similar between the two groups. However, significant differences were observed in donor site morbidity. Patients in the LMG group experienced more early postoperative complications related to oral functions, such as difficulties with drinking, eating, and speaking. On the other hand, BMG patients reported more long-term issues with oral tightness. These findings suggest that both grafts are suitable for urethral stricture repair, but the choice of graft may depend on individual patient circumstances, particularly regarding their tolerance for specific oral complications.

Additional Information

Author Contributions: All authors made a significant contribution to the work reported, whether that is in the conception, study design, execution, acquisition of data, analysis and interpretation, or in all these areas; took part in drafting, revising or critically reviewing the article; gave final approval of the version to be published; have agreed on the journal to which the article has been submitted; and agree to be accountable for all aspects of the work.

Disclosures

Conflicts of Interest: The authors have no conflicts of interest to declare.

Confidentiality of Data: The authors declare that they have followed the protocols of their work center on the publication of data from patients.

Protection of Human and Animal Subjects: The authors declare that the procedures followed were in accordance with the regulations of the relevant clinical research ethics committee and with those of the Code of Ethics of the World Medical Association (Declaration of Helsinki).

Financing Support: All authors have declared that no financial support was received from any organization for the submitted work.

Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work.

Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work.