Dorsal onlay lingual mucosal graft urethroplasty for urethral strictures in women

Authors


Girish K. Sharma, Department of Urology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India.
e-mail: drgirishuro@yahoo.com

Abstract

Study Type – Therapy (case series)
Level of Evidence 4

OBJECTIVE

To describe the technique and results of dorsal onlay lingual mucosal graft (LMG) urethroplasty for the definitive management of urethral strictures in women.

PATIENTS AND METHODS

In all, 15 women (mean age 42 years) with a history suggestive of urethral stricture who had undergone multiple urethral dilatations and/or urethrotomy were selected for dorsal onlay LMG urethroplasty after thorough evaluation, from October 2006 to March 2008. After a suprameatal inverted-U incision, the dorsal aspect of the urethra was dissected and urethrotomy was done at the 12 o’clock position across the strictured segment. Tailored LMG harvested from the ventrolateral aspect of the tongue was then sutured to the urethrotomy wound over an 18 F silicone catheter.

RESULTS

The preoperative mean maximum urinary flow rate of 7.2 mL/s increased to 29.87 mL/s, 26.95 mL/s and 26.86 mL/s with a ‘normal’ flow rate curve at 3, 6 and 12 months follow-up, respectively. One patient at the 3-month follow-up had submeatal stenosis and required urethral dilatation thrice at monthly intervals. At the 1-year follow-up, none of the present patients had any neurosensory complications, urinary incontinence, or long-term functional/aesthetic complication at the donor site.

CONCLUSION

LMG urethroplasty using the dorsal onlay technique should be offered for correction of persistent female urethral stricture as it provides a simple, safe and effective approach with durable results.

Abbreviations
LM(G)

lingual mucosa(l) (graft)

BM(G)

buccal mucosa(l) (graft)

Qmax

maximum urinary flow rate

VCUG

voiding cysto-urethrography

PVR

postvoid residual urine volume

CISC

clean intermittent self-catheterization.

INTRODUCTION

The incidence of lower urinary tract obstruction, held responsible for LUTS in women has been reported in 2.7–8% of cases [1–3]. Urethral stricture accounts for 4–13% of cases of female BOO presenting with LUTS [4–6]. Strict diagnostic criteria of female urethral stricture disease have not been established because of its rarity. A female urethral stricture has been defined as a fixed anatomical narrowing of <14 F between the bladder neck and distal urethra responsible for symptoms and preventing instrumentation. This 14 F threshold was chosen as the lower limit value of ‘normal’ urethral diameter in young-adult women based on lack of clinical finding of LUTS in such candidates [7]. According to Defreitas et al. in women, a detrusor pressure of >25 cmH2O and a maximum urinary flow rate (Qmax) of <12 mL/s is consistent with obstruction [8].

The aetiology of female urethral stricture is a controversial subject; however, most urethral strictures in females are of iatrogenic or traumatic origin, e.g. after prolonged or difficult catheterization, childbirth, pelvic fracture, surgical repair of urethral diverticulum, fistula or incontinence and after pelvic radiation. While there are many reports of female urethral stricture disease after acute or chronic urethritis and cystitis but many cases remain idiopathic [9]. In the recent past, it was a common practice to use urethral dilatation in women with LUTS including for urgency, frequency and recurrent UTI, and many cases of iatrogenic urethral stricture are probably the result of these unnecessary or overzealous dilatations with subsequent fibrosis from bleeding and extravasation [10].

The current opinion for the treatment of female urethral stricture suggests judicious application of urethral dilatation, or urethrotomy as recurrence rates remain high and this may exacerbate periurethral fibrosis, therefore consideration should be given for early open repair after recurrence following a conservative approach [1,10].

PATIENTS AND METHODS

We selected 15 women with urethral stricture disease, with a mean (range) age of 42  (25–65) years, for corrective surgery using dorsal lingual mucosal graft (LMG) from October 2006 to March 2008. All patients had a history suggestive of urethral stricture disease and were evaluated with a physical examination: ultrasonography of the kidney, ureter, and bladder region for upper tract changes, urinary bladder appearance and the postvoid residual urine volume (PVR); voiding cysto-urethrography (VCUG) to show changes in the upper tract and urinary bladder, bladder neck and dilated urethra proximal to stricture segment; urethrocystoscopy using a paediatric scope; and urodynamic studies in selected cases.

Patients with a history of urethral, urinary bladder and gynaecological malignancy were not included in the present study. Other exclusion criteria were leukoplakia, submucosal fibrosis or malignancy of the oral cavity, oral neuropathies, patients with primary bladder neck obstruction or with a history of anti-incontinence procedures.

In most of the women (nine of 15) stricture was idiopathic, in three there was a history of prolonged catheterization while obstetric trauma and previous urethral caruncle surgery were implicated in two and one patients, respectively. All of these patients with recurrent LUTS had had previous interventions including multiple urethral dilatations and/or urethrotomy with relief of their symptoms for few weeks to months followed by recurrence of their obstructive voiding symptoms.

For the procedure, patients were asked to maintain oral hygiene and were started on 5% povidine iodine mouth gargling thrice daily, 48 h before surgery. The surgical procedure was performed under combined spinal and epidural block for postoperative maintenance of analgesia and general anaesthesia was given only at the time of LMG harvesting to reduce the duration of general anaesthesia with the oro-tracheal tube fixed at an angle in the mouth on the right side.

After placing the patient in the dorsal lithotomy position, povidine-iodine preparation was used in the perineal area. A 6–10 F infant feeding tube or ureteric catheter over a guidewire was inserted into the urethra. Two traction sutures using 3/0 chromic catgut suture were applied at the 3 and 9 o’clock positions of the urethral margin. An inverted-U incision was marked in the suprameatal region from the 3 to 9 o’clock position to expose the dorsal aspect of the urethra (Fig. 1). The desired length of the urethra was dissected free by sharply dissecting the vulvar mucosa off the urethral channel (Fig. 2) by developing a plane between the urethra and clitoral cavernosal tissue with care so as not to damage the bulb, clitoral body crura and the anterior portion of the striated sphincter that was reflected upward. Dorsally the urethral wall was incised from the meatus through the strictured segment at the 12 o’clock position until reaching normal urethral mucosa, where a 4/0 polyglactin marker suture was placed. The proximal ‘normal’ appearing urethra was then calibrated and the length of the urethrotomy wound measured to find the required length of the LMG.

Figure 1.

Inverted-U incision in suprameatal region from the 3 to 9 o’clock position.

Figure 2.

Plane of dissection between the dorsal aspect of the urethra and the overlying clitoral cavernosal tissue and the dorsal urethral incision.

After oro-tracheal intubation, a mouth opener was placed and oro-pharyngeal packing was used to prevent aspiration. The tongue was pulled out of the mouth with a traction suture applied at tip of the tongue. The required LMG length was then marked with a mucosal deep incision of 10–15 mm width on the ventro-lateral aspect of the tongue starting from its posterior part. Two stay sutures (4/0 chromic catgut suture) were taken at the proximal margin of the LMG to elevate it, and a full thickness LMG was then harvested using a right-angled scissors. The donor site was closed simultaneously with 4/0 polyglactin suture in a continuous running fashion with interlocking, to achieve haemostasis and good cosmesis (Fig. 3). The harvested LMG was then processed by removal of all the submucosal adventitial tissue and tailored according to the required length.

Figure 3.

Tailored LMG and closed LMG-harvest site with continuous suturing.

For the dorsal onlay LMG urethroplasty, the mucosal aspect of the tailored LMG was placed upon the urethral lumen as shown in Figure 4. The LMG was fixed most proximally with a pre-placed marking suture; subsequently the graft was sutured to the right and left urethral edge including bits of tissue from the roof for proper dorsal fixation, using interrupted 4/0 polyglactin suture with particular attention to mucosa-to-mucosa apposition, over an 18 F indwelling silicon catheter. Before making the most distal sutures, the graft was also fixed dorsally with one suture midway and then distally it was quilted to the clitoral body to cover the new urethral roof. Then the vulvar mucosa was re-approximated with interposed lingual mucosal graft by taking knots of interrupted sutures outside the lumen (Fig. 5). A mild compressive vaginal pack dressing was then applied.

Figure 4.

Mucosal aspect of tailored LMG is placed for apposition of margins of LMG with urethrotomy wound.

Figure 5.

External meatus appearance at the end of the urethroplasty.

RESULTS

After 15 days the patients underwent a trail of voiding and VCUG to establish a ‘normal’ urethra. Patients were then followed at 3, 6 and 12 months with uroflometry and a detailed questionnaire about relief of voiding symptoms and urinary incontinence if any. VCUG was advised at the 6- and 12-month follow-ups and urethrocystoscopy performed if required at of the follow-up visits. The criteria for a successful reconstruction was a Qmax of ≥15 mL/s with a normal appearing flow rate curve in asymptomatic patients with no postoperative requirement of any kind for instrumentation and a normal VCUG.

The mean urethral stricture and harvested graft length in the present series was 2.45 cm and 2.95 cm, respectively. The preoperative mean Qmax of 7.2 mL/s increased to 29.87 mL/s, 26.95 mL/s and 26.86 mL/s with normal flow rate curves at the 3-, 6- and 12-month follow-ups, respectively. One patient had wound infection and was managed conservatively. At the 3-month follow-up, this patient had recurrence of obstructive voiding symptoms with a Qmax of <15 mL/s and upon evaluation was found to have submeatal stenosis. This patient required urethral dilatations at monthly intervals, which resolved the voiding symptoms and the Qmax improved from 11 mL/s to 22 mL/s at the 6 month follow-up with no PVR and a normal VCUG. At the 1-year follow-up, none of the present patients complained of any neurosensory complication, urinary voiding symptoms or urinary incontinence, or any long-term functional or aesthetic complications at the donor site.

DISCUSSION

Typically, a minimally invasive procedure in the form of urethral dilatation followed by clean intermittent self-catheterization (CISC) is the initial procedure offered to women with urethral stricture disease, but the incidence of short-term recurrences of stricture after this method is high, because of lack of compliance with CISC. Apart from this, there is no generalized consensus for the best size of catheter to be used and the best regimen of CISC in these patients [7].

Several materials have been tried for substitution urethroplasty or total urethral reconstruction and essentially they fall into two groups, i.e. a vascularized flap from the local genital region or free grafts. Difficulties arise where suitable local tissue is lacking as in women with low oestrogen level physiological states or in women with lichen sclerosus where the perivulvar skin becomes fragile, thin and atrophic with scarring leading to fusion of the labia minora and narrowing of the introitus [11].

Although few studies are available on female urethral stricture disease, reports by various authors during the last 5–6 years, suggest that surgical repair of the stricture eliminates or decreases the number of repeated urethral dilatations and urethrotomies, especially in women who are not compliant with CISC.

In 2002, Tanello et al.[12] described the use of a pedicle flap from the labia minora in the treatment of urethral strictures in two women. Although the series was small, the outcomes were good with resolution of the strictures. In a larger series, Montorsi et al.[13] described the use of a pedicle flap from the vaginal vestibule for patch urethroplasty in 17 women with significant improvement in voiding symptoms in 15 (88%) of their cases. Schwender et al.[1] created a vaginal flap in an inverted U-shape, with its apex at the urethral meatus to repair urethral strictures in eight women. They advocated it to be a simpler procedure, as it did not require tissue tunnelling or flap rotation apart from a little distortion of the vagina and paravaginal tissue. The mean calibre of the urethra in their series increased from 9.25 F to 16.5 F with subjective relief of voiding symptoms in a mean follow-up of 2.5 years and only one patient required a repeat dilatation, at 3 weeks after the primary procedure.

Since the first reported use of buccal mucosa (BM) in urethroplasty for male stricture by el Kasaby et al.[14], and given the success of BM grafts (BMG) in male urethroplasty in numerous reports, authors have applied this technique to female urethral stricture disease [10,15,16].

Berglund et al.[16] presented the first series of two women treated with a ventral BMG for urethral stricture, although one had recurrence of LUTS requiring meatal dilatation. Tsivian and Sidi [15] treated three women with recurrent urethral stricture by dorsal graft urethroplasty using vaginal mucosa in two and BMG in one. All the women had normal voiding after catheter removal and no further intervention was required during 1, 8, and 27 months of follow-up in that series. Migliari et al.[10] performed a similar procedure using dorsal BMG onlay in three women with urethral strictures and reported good results with unobstructed Blaivas-Groutz nomograms on follow-up urodynamics.

The mucosa covering the ventro-lateral aspect of the tongue has no particular functional features, is thin, smooth, and identical in structure to that lining the rest of the mucosa of the oral cavity. Considering these favourable properties of LM, Simonato et al.[17] used LMG for managing urethral stricture in eight men and reported successful reconstruction in seven at the 1-year follow-up. Since then reports of LMG urethroplasty in male anterior urethral stricture disease from our centre have been published [18–21]. In the present study, we chose LM as the graft material because of our previous experience with LMG harvesting with minimal morbidity and good results for urethroplasty in men.

LM fulfills all the requirements of an optimal graft material for substitution urethroplasty, i.e. like BM, LM is easily accessible, hairless, naturally wet, has favourable immunological properties (resistance to infection) and optimal tissue characteristic (thick epithelium, high elastic fibre content, thin lamina propria, rich vascularization thus favouring imbibition, inosculation and re-vascularization) [17].

  • • LMG can be easily harvested as the tongue can be pulled to the operative field outside the oral cavity.
  • • A mucosal strip of up to 7–8 cm long can be harvested from one ventro-lateral aspect of tongue in continuity with minimal-to-no donor-site morbidity [18].

Distinct advantages of a harvesting LMG instead of a BMG are the complete avoidance of injury to the parotid duct and mental nerve and avoidance of deviation of the angle of the mouth and retraction of the lip.

Recently, small series using the dorsal approach for female urethroplasty by Migliari et al.[10] and Tsivian and Sidi [15] showed that possible injury to the neurovascular bundles of the clitoris is avoidable, as they are quite far from the dissection area and the striated urogenital sphincter in the dorsal approach is preserved by reflecting it upward. On the dorsal aspect, the urethra is only juxtaposed to the clitoral structure, which is carefully preserved during dissection. The advantages of using the dorsal approach in female urethroplasty are:

  • • Sacculation of the graft is minimized [10].
  • • The graft is well supported mechanically and rests on a well-vascularized bed.
  • • Graft apposition on the dorsal aspect of the urethra leads to physiological urethral reconstruction with resultant urinary stream directed away from the vagina [10].
  • • Prevents the possibility of urethrovaginal fistula formation [15].
  • • The ventral aspect of the urethra is left intact thus leaving the possibility of mid-urethral anti-incontinence procedures in the event of any future incontinence.

In conclusion, LMG urethroplasty using the dorsal onlay technique should be offered for correction of persistent female urethral stricture as it provides a simple, safe and effective approach with durable results and no increased risk of urinary incontinence. However, long-term studies in randomized controlled settings are required to evaluate its efficacy as a procedure for early intervention rather than as a last resort in the management of female urethral stricture disease.

CONFLICT OF INTEREST

None declared.

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