Urethroplasty with Pedicled Tunica Vaginalis for the Treatment of Long-segment Anterior Urethral Stricture Caused by Lichen Sclerosus of Glans Penis

Summary

This article introduces a surgical method using a pedicled tunica vaginalis to treat long-segment urethral stricture resulting from lichen sclerosus. The tunica vaginalis is an excellent substitute for the urethra, leading to quick postoperative recovery for patients.

Abstract

Urethroplasty for the management of long-segment urethral strictures associated with lichen sclerosus presents considerable clinical challenges. Oral mucosal grafts are commonly employed but are vulnerable to posttransplantation infection and recurrent stricture formation. Furthermore, the necessity for anesthesia and oral graft harvesting restricts their application in primary healthcare settings.

The single layer of flattened epithelium of the tunica vaginalis can serve as a potential alternative to oral mucosa. Animal experiments have demonstrated that the tunica vaginalis can readily form a tight connection with the multilayered urothelium of the urethra. Utilizing the tunica vaginalis as a scaffold for urethral re-epithelialization may help reduce the risk of recurrence of urethral stricture after surgery. Over a 19 year period, pedicled tunica vaginalis urethroplasty has been used for successfully treating 86 cases.

The surgical procedure involves dorsally incising the urethral stricture segment, then covering it with a pedicled tunica vaginalis patch followed by suturing. Postoperatively, the pedicled tunica vaginalis graft exhibits good vascularization and take rate, facilitating urethral re-epithelialization. The surgical procedure is conducted in a sterile environment to mitigate the potential for infectious complications. Moreover, the operation can be executed under spinal anesthesia, which facilitates its implementation in primary healthcare settings.

Introduction

Lichen sclerosus (LS) of the penis is a chronic inflammatory dermatological condition mediated by lymphocytes, and it is considered an acquired dermatosis¹. Hallmark symptoms of LS of the penis include chronic inflammation of the glans penis, abnormal dryness in the appearance of the affected skin, and endarteritis in the subcutaneous arteries supplying the glans penis². Most patients with LS of the penis have a history of phimosis, with lesions primarily occurring on the foreskin, glans penis, external urethral meatus, or anterior urethra. Some patients may be asymptomatic throughout the disease course, while others can experience foreskin and glans adhesions leading to phimosis and voiding difficulties due to urethral lesions³. The peak incidence of LS occurs in the age groups of 30-49 years and 8-10 years⁴. Clinical manifestations of LS are variable. In the early stages of the disease, symptoms can be inconspicuous. Initial changes may include milky-white plaques, recurrent ulcers, or purulent discharge on the inner foreskin and glans, accompanied by itching, stinging, and burning sensations.

As LS progresses, decreased elasticity of skin and mucosa develops due to atrophic changes of the foreskin and glans, which can negatively impact sexual function. As the LS further progresses, the external urethral meatus may become stenotic owing to LS invasion, and even long segment anterior urethral stricture may form with the proximal extension of lesions. However, LS involvement of the anterior urethra generally stops with the urethra bulbar and is rarely seen in the membranous and prostatic segments¹. Severe urethral stricture can result in increased postvoid residual urine, upper tract hydronephrosis, or renal damage. In urethroplasty for long-segment anterior urethral stricture caused by LS, grafts are usually required to be implanted in the urethra.

Long-segment anterior urethral strictures, defined as strictures exceeding 2 cm in length within the anterior urethra, pose a significant clinical challenge in management and often necessitate the utilization of grafts or substitutes to repair the urethral defect-a procedure known as urethroplasty⁵. Among the commonly employed urethral substitutes are bladder mucosa⁶, oral mucosa⁷, colonic mucosa⁸, preputial graft⁹, and tunica vaginalis¹⁰, each possessing unique advantages and limitations.

The tunica vaginalis, an extension of the peritoneum, has exhibited promising outcomes in both preclinical animal models and clinical trials as a substitute material for urethral reconstruction^11,12,13,14. Its mesothelial nature confers an intrinsic ability to mitigate scar tissue formation. Experimental evidence from animal studies¹⁵ has indicated that the single layer of flattened epithelial cells comprising the tunica vaginalis readily establishes a tight junctional interface with the multilayered epithelial cells of the urethral mucosa.

Here, we utilized the technique of transplanting a pedicled tunica vaginalis patch to address long-segment anterior urethral strictures caused by lichen sclerosus of the glans penis (Figure 1). From August 2004 to April 2023, 86 cases were successfully completed, yielding satisfactory postoperative outcomes. This surgical approach offers a novel and effective treatment modality for patients with long-segment anterior urethral strictures caused by lichen sclerosus of the glans penis.

It overcomes the limitations associated with other surgical techniques, boasting a high success rate, convenient material sourcing, simplicity of execution, minimal invasiveness, and a reduced incidence of complications¹³.

However, long-segment anterior urethral stricture caused by lichen sclerosus of the glans penis is not very commonly employed worldwide, and the literature on the subject is not abundant¹⁶. Yet it warrants implementation in medical institutions at all levels, particularly at grassroots facilities, as an ideal method for treating long-segment anterior urethral strictures.

Protocol

The study cohort comprised 86 male patients aged between 20 and 66 years, with a mean age of 40. Each patient received a single-stage tunica vaginalis graft, with 70 cases involving a unilateral tunica vaginalis graft and 16 cases involving a bilateral tunica vaginalis graft. The patients provided informed consent to use and publish their data.

1. Preoperative preparation

Ensure that patients with concurrent urethral infection undergo preoperative cystostomy first. Examine urinary bacterial cultures according to the drug sensitivity results and then, use antibiotics to which the bacteria are sensitive to treat them for 2-3 weeks before surgery. Perform the surgery after the urethral infections are sufficiently under control.

1. Ensure that patients with concomitant urethroperineal fistulas undergo cystostomies first. Perform the surgery 3 to 5 months after the healing of the fistulas (Figure 2).
2. Ensure that patients with concurrent unilateral epididymitis undergo anti-infective treatment first and perform the surgery 3 weeks after inflammation has been controlled.
3. Ensure that patients with concurrent bilateral epididymitis undergo cystostomy first and perform the surgery 3 months after epididymitis is under control.
4. Ensure that all patients undergo retrograde urethrography and uroflowmetry examinations.

2. Surgical positioning of patients

NOTE: The surgical positioning must vary according to the location of the urethral stricture in each patient.

1. Place the patient in supine position if the patient's urethral stricture is from the urethral meatus to the junction of the penis and scrotum (Figure 3A).
2. Place the patient in supine or lithotomy position if the patient's urethral stricture is from the urethral meatus to the bulbar urethra (Figure 3B).
3. Place the patient in lithotomy position if the patient's urethral stricture is from the urethral meatus to the proximal end of the bulbar urethra (Figure 3C).

3. Surgical procedure

1. Exposure of the urethral stricture segment (Figure 4A).
   1. Perform the procedure under combined spinal-epidural anesthesia.
   2. Measure and mark a position approximately 0.5 cm proximal to the coronal sulcus (the indented margin between the glans penis and the penile shaft) as the starting point.
   3. Perform a circumferential incision of the foreskin at the marked position.
   4. After the incision, gradually retract the foreskin proximally towards the base of the penis. Carefully dissect and release any adhesions of the inner foreskin during this process until the penile Buck's fascia is fully exposed.
2. Incision of the urethral stricture segment (Figure 4B,C).
   1. Make a ventral longitudinal incision along the stenotic urethral segment, extending approximately 0.5-1.0 cm into the adjacent normal urethral tissue.
      NOTE: Make sure the incision is precise in length, without causing unnecessary trauma to the surrounding healthy tissues.
   2. Following the incision, examine the incised site to confirm that the area of urethral stricture has been adequately exposed.
3. Harvest a pedicled rectangular tunica vaginalis (Figure 4D).
   1. Perform a longitudinal incision through the scrotal wall. Through this incision, sequentially incise the layers of skin and the underlying fascia to gradually expose the parietal layer of the tunica vaginalis.
   2. Make an arcuate incision on the tunica vaginalis wall, in proximity to the epididymal margin. Through this incision, open the tunica vaginalis cavity.
   3. Harvest a rectangular flap of approximately 1 cm x 10 cm within the tunica vaginalis cavity through excision along the course of the epididymis. During the excision, carefully preserve the blood vessels, fascia, and any other attachments to the rectangular flap (pedicled tunica vaginalis).
   4. Utilizing hemostatic forceps, gently create a tunnel through blunt dissection in the subcutaneous loose connective tissue between the scrotum and the base of the penis. Ensure that the tunnel is adequately sized to allow the passage of the pedicled tunica vaginalis flap without undue compression or restriction.
   5. Carefully feed the pedicled tunica vaginalis flap through the tunnel without torsion, and subsequently mobilize it to the site of the incised ventral urethra.
4. Urethral reconstruction by sutures (Figure 4E, F).
   1. Retain the incised urethral stricture segment as a urethral plate. Orient the smooth serosal surface of the mobilized tunica vaginalis flap to face the urethral plate.
   2. Use 5-0 absorbable sutures to place continuous running locked sutures separately, approximating the edge of the tunical flap to both sides of the urethral incision. Continually inspect the patency of the urethral lumen and the watertight closure at the suture line throughout the suturing process.
5. Final stage of the operative procedure (Figure 4G, H).
   1. Carefully insert a Foley catheter, sized 24 French (F24), into the urethra.
   2. Meticulously reposition the foreskin over the glans penis.
   3. Close the scrotal tissue in layers using fine, absorbable sutures.

4. Special cases

1. Case 1: Bilateral tunica vaginalis grafts during urethroplasty (Figure 5).
   1. Position the patient in lithotomy (due to the urethral stricture extending from the urethral meatus to the proximal bulbar urethra).
   2. Following the incision from the urethral meatus to the penoscrotal junction, make a perineal incision and continue the incision through the stricture in the bulbar urethra. Harvest rectangular grafts from both testicles.
   3. Proceed with the ensuing procedure in accordance with the surgical steps outlined above in section 3.
2. Case 2: Preserving glans appearance during urethroplasty (Figure 6).
   1. Given the patient's well-developed glans, perform a subcoronal ventral urethrotomy to preserve the natural contour of the glans.
   2. Proceed with the ensuing procedure in accordance with the surgical steps outlined above in section 3.

5. Postoperative care

1. Upon completion of the surgery, ensure that the catheter is retained in the urethra for 3 weeks. While ensuring the patency of the catheter, promptly cleanse any secretions at the urethral opening.
2. Postoperatively, start the patients on a liquid diet initially, transitioning to a normal diet within 3-5 days. During the postoperative recovery phase, advise the patients to to reduce the frequency of bowel movements to aid in the healing process.
3. Make sure all patients undergo retrograde urethrograms at 3 weeks post surgery, followed by uroflowmetry 1 week after catheter removal.
4. Calculate the mean ± standard deviation (X± S) of the patient's preoperative and postoperative maximum urinary flow rates and perform statistical analysis using software of choice. Perform intergroup comparisons using t-tests, with a P-value < 0.05 considered statistically significant.

Results

See Supplemental Table S1 for patients' clinical history and preoperative measures. Preoperatively, all 86 patients underwent retrograde urethrography and uroflowmetry examinations. Each patient received a single-stage tunica vaginalis graft, with 70 cases involving a unilateral tunica vaginalis graft and 16 cases involving a bilateral tunica vaginalis graft. Postoperative follow-up ranged from 6 to 48 months, with a mean of 24 months. Among these individuals, 84 exhibited unimp...

Discussion

Numerous urological researchers have investigated a diverse range of graft materials for urethral reconstruction, including genital and extragenital flaps or free grafts¹⁷. These materials include preputial graft, bladder mucosa, oral mucosa, tunica vaginalis, and colonic mucosa.

Oral mucosal grafts have achieved high success rates for the treatment of anterior urethral strictures caused by LS, with Xu et al. reporting a success rate of 88.9%¹⁸. ...

Materials

Name	Company	Catalog Number	Comments
2-0/T non-absorbable suture	Ethicon Inc	SA845G	Sterile, radiation sterilization, disposable
22F silicone catheter	UROVISION	G2219043	A disposable Foley Catheter
3-0 non-absorbable suture	Ethicon Inc	SA84G	Sterile, radiation sterilization, disposable
5-0 absorbable suture	Ethicon Inc	VCP1433	Sterile, radiation sterilization, disposable
Digital X-ray Radiography Fluoroscopy System	Beijing Shimadzu Madical Equipment Co.,Ltd	ZS-200	Retrograde urethrograms use
Iohexol Injection	STARRY PHARMACEUTICAL	H20203258	Sterile, disposable,Retrograde urethrograms use
SPSS 20.0			statistical software
Urodynamic Analyzer	WBL MEDICAL	Nidoc 970A	Maximum flow rate detection