//Combined dorsal plus ventral double buccal mucosa graft in bulbar urethral reconstruction.
Combined dorsal plus ventral double buccal mucosa graft in bulbar urethral reconstruction.2017-04-05T18:51:39+00:00

Combined dorsal plus ventral double buccal mucosa graft in bulbar urethral reconstruction

Uretra, stenosi uretrale

pdf chirurgia uretrale

Authors:
Enzo Palminteri, Elisa Berdondini, et Al.

Publication:
2007 European Association of Urology.

Volume:
176 : 1473 – 1476

Centre:
Center for Reconstructive Urethral and Genitalia Surgery, Arezzo, Italy

 

Abstract

Objectives:
We describe a technique for bulbar urethral reconstruction using a combined dorsal plus ventral double buccal mucosa graft (BMG).

Methods:
From March 2002 to June 2006, 48 men (mean age 35years) with bulbar strictures underwent patch urethroplasty using a dorsal plus a ventral double BMG. Average stricture length was 3.65 cm (range 2 to 10). The stenotic urethral segment was opened along its ventral surface; the exposed dorsal urethra was incised in the midline to create an elliptical area over the tunica albuginea where the dorsal-inlay BMG was placed and quilted to the corpora to augment dorsally the urethral plate. Subsequently, the ventral-onlay BMG was sutured to the urethral lateral margins to complete the augmented urethroplasty. Finally, the spongiosum was closed over the graft. Successful reconstruction was defined as normal voiding without need for any postoperative procedure including dilation.

Results:
Mean follow up was 22 months (range 13 to 59). At the catheter removal 3 weeks after surgery, in 3 patients the voiding cystourethrography showed a fistula which recovered by a prolonged catheterization. Of 48 cases 43 (89.6 %) were successful and 5 (10.4 %) failures with recurrence of the stricture: 4 were treated with internal urethrotomy and 1 with a temporary perineal urethrostomy.

Conclusions:
Preliminary results with a combined double BMG urethroplasty for severe bulbar stricture are encouraging. The double dorsal and ventral graft may provide a simple and reliable solution to achieve an adequate urethral lumen in selected patients.

1. Introduction
According to stricture length several surgical techniques have been described to treat bulbar urethral strictures. Bulbar strictures < 2 cm are generally repaired with excision and end-to-end anastomosis; for strictures 2-3 cm in length it has been advocated a graft augmented anastomotic procedure, while strictures > 3 cm are usually repaired by patch urethroplasty using buccal mucosa graft (BMG) [ 1, 2, 3, 4 ].
The advantages of the BMG, compared to penile skin flaps or other kind of grafts such as genital/extragenital skin or bladder/intestinal mucosae, include a cosmetically superior incision, decreased operative time, low harvest morbidity and better histological graft characteristics [ 3, 5 ].
The techniques are various and the location of the patch has become a contencious issue with different series reporting BMG placed either ventrally or dorsally to augment the strictured urethra [ 6, 7, 8, 9, 10 ].
We report our medium-term followup in bulbar urethral reconstruction using a combined contemporary dorsal-inlay plus a ventral-onlay double buccal mucosa graft to augment the preserved urethral plate.

2. Methods
Between March 2002 and June 2006 we repaired 48 bulbar urethral strictures with a double buccal mucosa graft. Mean patient age was 35 years (range 8 to 69). Stricture etiology was unknown in 34 cases, ischemia in 10, trauma in 3, urethritis in 1. Of the 48 patients 47 (98%) had undergone an average of 2.5 prior urethrotomies (range 1 to 9) and dilatations.
2.1. Preoperative evaluation
Preoperative evaluation included clinical history, physical examination, urine culture, uroflowmetry, retrograde-voiding cystourethrography, sonourethrography and urethroscopy. Sonourethrography was performed contemporary to the retrograde cystourethrography, reducing the discomfort of an additional investigation. Patients were informed that bulbar patch urethroplasty is a safe procedure as far as sexual function is concerned.
2.2. Surgical technique
We performed the bulbar urethroplasty using a dorsal-inlay plus ventral-onlay double graft of BM for the urethral augmentation.
The urethral procedure is done with the patient in the normal lithotomy position. Through an Y inverted incision the bulbocavernous muscles are divided, exposing the bulbar urethra. Using a ventral-sagittal urethrotomy the strictured urethra is opened guided by an guide wire and methylene blue previously injected to define the narrow lumen. The urethra is laid open for 1 cm both proximally and distally into the healthy urethra (fig. 1).
2.2.1. Dorsal-inlay patch augmentation
As Asopa suggested the exposed dorsal urethra is incised in the midline down to the tunica albuginea [ 11 ]. The margins of the incised dorsal urethra are dissected from the tunica by sharp dissection with a scalpel, without lifting the two halves of the bisected urethra (fig. 2): an elliptical raw area is created over the tunica albuginea (fig.3) and the incised dorsal free margins of the urethra are anchored by interrupted stitches to the tunica. The first BMG is sutured into the recipient elliptical area: the graft is quilted to the underlying tunica and fixed to the urethral mucosal margins with interrupted stitches 6-zero polyglactin to prevent the formation of a potential hematoma into a dead space (fig. 4).
2.2.2. Ventral-onlay patch augmentation
Subsequently to the dorsal urethral augmentation, the lumen is also graft-enlarged ventrally according to the McAninch procedure: the second BMG is sutured laterally to the left mucosal margin of the urethral plate with a running suture 6-zero [ 3 ]. The catheter is inserted and finally the graft is rotated and sutured laterally to the right mucosal margin (fig. 5).
An inverted ventral graft quilting is made with few stitches fixing the spongiosum to the graft. Finally the adventitia of the spongiosum is closed over the graft with 4-zero running suture (fig. 6).
The pre-operative assessment by urethrography and ultrasonography (fig. 7) may help in selecting the procedure, but in urethral reconstruction usually intra-operative local factors will address towards the final choice of the technique. Thus we used the combined double patch to enlarge the urethra better in tight strictures characterized by a narrow residual urethral plate, scarred and/or compromised from stenotic rings, in which a single patch seemed to be insufficient to make a wide enough lumen.
In all patients after the combined ventral and dorsal opening of the stricture, the fibrotic tissue is partially excised from the urethral margins while preserving the remaining urethral plate. Neourethras were created by anastomoting the BM grafts in inlay/onlay patch fashion to the mucosal margins of the urethral plate.
We used a 2-team approach, with 1 team harvesting the BMG while the 2 team exposed the stricture. The BMG was harvested from the inner cheek and the donor site closed with 4-zero polyglactin interrupted stitches or running suture. We initially used a nasotracheal intubation but we did noticed that this resulted in more postoperative discomfort and no greater access to the inner cheek. Now we prefer an orotracheal tube taped over to the controlateral side and a Kilner-Doughty oral retractor , providing an excellent inner cheek exposure (fig. 8).
In 5 patients the two BM grafts were harvested bilaterally from both cheeks, while in 43 patients a wide single BMG was harvested from the right cheek and subsequently tailored into two smaller grafts according to the length of the dorsal and ventral urethral openings.
Average length of the harvested graft was 6.16 cm (range 4 to 8). Average width of the harvested graft was 1.89 cm (range 1 to 2.5). Average length of the graft used dorsally was 2.36 (range 1 to 5) and average length of the graft used ventrally was 4.68 (range 4 to 11). Average stricture length was 3.65 cm (range 2 to 10).
A 16 Fr silicone Foley catheter was left in place. Patients were discharged home on the third post-operative day. Voiding cystourethrography was done at the catheter removal 3 weeks after surgery. Uroflowmetry and urine cultures were repeated every 4 months in the first year and annually thereafter. Whenever obstructive symptoms developed or peak flow rate deteriorated < 14 ml./s, urethrography and urethroscopy were repeated. Successful reconstruction was defined as normal voiding without need for any postoperative procedure, including dilation.

3. Results
Mean follow up was 22 months (range 13 to 59). Of 48 cases 43 (89.6 %) were successful and 5 (10.4 %) failures. There were no early postoperative complications, such as wound infections, hematomas, bleeding. In 3 patients a fistulas was evident at the voiding urethrography after catheter removal: a 12 Fr Foley catheter was reinserted and maintained for two additional weeks with subsequent fistula resolution.
Postoperative average peak urinary flow of successful patients was 31.02 ml/s versus the preoperative average peak urinary flow of 7.64 ml/s.
Of the successful cases, stricture average length was 3.53 cm, dorsal graft average length 2.32 cm and ventral graft average length 4.47 cm. Of the 5 failed cases, stricture average length was 4.4 cm, dorsal graft average length 3.1 cm and ventral graft average length 5.6 cm.
In all patients with stricture recurrence the radiological and endoscopic evaluation provided useful information about disease extension. Of 5 failures, 2 patients developed a re-stricture 1 cm long at the distal site of the urethral reconstruction, 1 patient developed a stenotic ring at the distal site of the urethral reconstruction and 1 patient two stenotic rings together at the distal and proximal site of the urethral reconstruction. All these patients were treated with internal urethrotomy. One failure occurred in a patient 8-years-old with a primary ischemic stricture 10 cm long who underwent to dorsal augmentation by a BMG 4 cm long and ventral augmentation by two BMG placed serially (5 cm plus 5 cm). This child developed two restrictures both 1 cm long: the fibrotic urethral tract was opened leaving a perineal urethrostomy and currently the patient is awaiting for a staged solution. Primary stricture etiology of the failures was ischemic in 1 case and unknown in 4. Recurrences developed within 6 months after surgery in 3 cases and within 12 months in 2.
Of 48 patients 3 (6%) referred semen sequestration but urethrography and urethroscophy failed to demonstrate urethrocele.

4. Discussion
Anastomotic urethroplasty has traditionally been reserved for strictures no more than 2 cm long, but recently the accepted limits are expanding and successful anastomotic repair was reported for urethral defects of 3 or, even up to 5 cm [ 1, 12 ]. However, in addition to the resected strictured tract, the need of spatulation of the two stumps may lengthen the urethral gap increasing the risk of complications. Therefore a group stated that only bulbar strictures less than 1 cm were amenable to anastomotic reconstruction due to concerns that tension or tethering may cause restrictures or erectile problems [ 2, 13 ]. To reduce the risk of urethral chordee, graft augmented anastomotic procedures have been advocated , but even with these techniques the problem of vascular damage after the complete urethral transection is still present.
Conversely, when compared with BMG patch techniques, the anastomotic procedures showed an higher incidence of penile curvature (36% versus 8%), penile shortening (38% versus 11%), impaired erection (79% versus 15%), impaired sexual life (57% versus 19%). The overall satisfaction about sexual life was 97% in patients who underwent to BMG repairs versus 74% of the anastomotic repairs [ 14 ]. In a series of 200 patients Mundy reported temporary impotence in 53% who underwent anastomosis and 33% who underwent patch repair [ 15 ]. Coursey showed that anastomosis resulted in an overall dissatisfaction in erection and an alteration in erectile angle higher than BMG urethroplasty (respectively, 26% versus 19% and 44% versus 38%) [ 16 ]. After anastomotic procedures on 22 patients Morey reported chordee (44.4%), decreased penile length (ranged 22.2% to 33.3%), overall satisfaction on erectile function only in 55.6%; particularly he reported complete loss of erection in 2 patients (9%) [ 12 ].
We were impressed to find that anastomotic urethroplasties were associated with so high rate of erectile complaints. Factors impairing sexual life have an important impact of patient satisfaction and these problems may be as socially restricting as urethral stricture and may be more important than stricture recurrence. Success outcome in urethral repair should be assessed not only by objective voiding parameters but also by subjective parameters influencing satisfaction and these latter must be considered in the treatment choice. However, in some traumatic strictures because of the hard scarring the urethral plate may be not preservable and amenable for the enlargement, forcing to its resection by an anastomotic procedure. Thereby, the choice of the technique is always determined by the quality of the urethral plate.
Most urologists commonly perform graft urethroplasty for strictures longer than 2 cm. BM represents the first choice’s graft in the bulbar patch urethroplasty and many series shift from a ventral to a dorsal technique [ 3, 6, 7, 8, 9, 10, 17 ]. The dorsal graft placement can be performed by the Barbagli’s approach or the Asopa’s approach. The first consists in dissecting the urethra from the corpora cavernosa and its rotation of 180°; the exposed dorsal urethral surface is opened and augmented with the graft splayed on the corpora. In case of previous repeated dilations or internal urethrotomies the urethral detachment from the corpora may result difficult due to the fibrotic adhesions; furthermore this approach may damage erectile function and the bulbar arteries when the dissection from the corpora need to be very proximal [ 10, 18 ].
In the Asopa procedure the urethra is approached by a ventral-sagittal opening; subsequently, the dorsal urethra is medially incised to create an elliptical area over the corpora where the graft is placed. This approach is easy to perform because the scarred urethra with marked spongiofibrosis is not mobilized; there is less harm for the urethral plate because the space for grafting is created without lifting the two urethral halves from the corpora and thereby the blood supply is guaranteed by the saved circumflex and perforating arteries [ 11 ]. The only technical limit of this method is that it seems to create a dorsal urethral enlargement less wide than with the Barbagli’s procedure.
In the ventral graft placement by McAninch, after a ventral-sagittal urethral opening the graft is anastomosed to the margins of the preserved dorsal urethral plate. In the presence of an urethral plate very tight or compromised from stenotic rings the standard ventral augmentation could be inadequate. For these patients McAninch has suggested to harvest a 20 mm. wide graft and in cases in cases of near or complete obliteration of the urethra he used a 25 mm. wide graft [ 3 ].
By adopting a combined dorsal and ventral double enlargement of very narrow strictured tracts, we aimed to create neourethras sufficiently wide, more stable, reducing the risk of recurrence at the distal or proximal graft anastomosic sites [ 10, 19 ]. Comparing with different series of single graft urethroplasties, the double patch enlargement doesn’t show to decrease the failure rate, but it may allow in tight strictures to avoid the more aggressive anastomotic procedures with complete urethral transection that may compromise the spongiosum vascularity. Avoiding the transversal complete section of the spongiosum occurring in the anastomotic urethroplasties with or without added graft, we stick to the important concept of urethral plate and its vascularity preservation [ 20 ]. We also retained the original length of the urethral tube. Our aim was to maintain as much as possible the urethral axial integrity and to reduce the sexual complications related to an end-to-end urethroplasty, such as the chordee and the unpleasant feeling of loss of glans sensation. Even in our own experience with patients who underwent to anastomotic procedures we have noticed temporary loss of glans sensation perhaps related to vascular involvement of the spongiosum distally to the urethral section. Usually the dorsal or ventral single graft urethroplasty are performed without resection of any diseased tissues, while the double graft enlargement allows the partial removal of the fibrotic urethral tissues without jeopardizing the creation of an enough wide lumen. Furthermore the dorsal incision aims to release the scarred rings on the urethral plate.
The dorsal graft receives its vascular support by the corpora and the ventral graft is supported by the abundant ventral spongiosum. Only in the bulbar urethra the ventral spongiosum is hearty enough to provide vascularization adequate for graft viability and good mechanical support, preventing any sacculations or fistulas [ 3 ]. The inverted ventral graft-spongiosum quilting helps the graft survival. Furthermore, reducing the width of the ventral graft, the double graft technique may decrease the chance of fistulas and diverticulum.
In the past, full circumferencial urethral reconstruction by 1-stage graft tubes have demonstrated a high rate of complications due to diverticulum and/or restricture at the anastomotic sites. Differently, the double patch technique with the inclusion of the residual lateral strips of the urethral plate, allows a safer and more stable reconstruction avoiding a circumferential anastomosis and preserving the axial continuity of the lumen.
Similarly to McAninch we have successfully managed the recurrences by the internal urehrotomy; indeed, the well vascularized grafted area usually develops a short and soft stricture, which responds better to incision than primary strictures surrounded by abundant scar tissue.
Because graft failure significantly contributes to the deterioration of the final outcome of the bulbar urethroplasties, further long-term trials are necessary to clarify the technical limits of any procedure and the true etiology of the restrictures or other postoperative symptoms such as post-voiding dribbling and semen sequestration [10, 18]. In our series 3 patients referred semen sequestration but without evidence of urethral sacculation. Baskin supposed that the hypothetic damage during bulbar urethroplasty to the branches of the perineal nerves innervating the bulbospongiosus muscles may explane the loss of bulbar urethral contraction, causing difficulty in expelling semen and urine [21]. However, also other factors may have a role into the decreasing of bulbar urethral contractions such as the section of the perineal central tendon in the proximal bulbar strictures; finally, also the spongiofibrotic disease and the ventral-sagittal urethrotomy, causing an interruption of the structural circularity of the muscle-elastic urethral tube, may stop the voiding rhythmic urethral contractions. Surely the best technique is the one with which the surgeon is most comfortable, but no single technique is appropriate in all situations and the successful reconstructive surgeon needs to have a repertoire of methods from which to choose.

5. Conclusions
Bulbar urethroplasties are today generally performed with preservation of the urethral plate and using the BMG ventrally or dorsally placed. We have combined both these concepts aiming to reduce the risk of recurrence in tight stricture repairs in which a narrow and inelastic urethral plate may require a more substantial augmentation.
Longer follow up and compared series of bulbar repairs are necessary to clarify if the outcomes are related to the specific graft placement and to the use of a single or double patch augmentation.

Editorial Comment on: Combined Dorsal plus Ventral Double Buccal Mucosa Graft in Bulbar Urethral Reconstruction
Andre´ Cavalcanti
Hospital Municipal Souza Aguiar, Rio de Janeiro, Brasil
[email protected]
The use of a buccal mucosa graft is the first choice in bulbar urethral reconstruction. The success rate using buccal mucosa in the bulbar urethra is excellent, despite the graft position [1]. When we are performing any type of substitution, urethroplasty is necessary to observe the quality of the urethral plate after the urethrotomy. Anarrow urethral plate is associated with difficulty in adjusting the graft or flap during the suture, especially in some cases such as traumatic strictures. In my personal opinion, an acceptable urethral plate width must be at least 0.5 cm and preferably close to 1.0 cm. When we are working with a urethral width The graft-augmented anastomotic urethroplasty [4] has been proposed as an option to increase the results of graft urethroplasty. This technique basically materializes the improvement in the urethral plate quality with the resection of the worst fibrotic area and an ‘‘anastomotic’’ reconstruction before the graft placement. But, as in any anastomotic urethroplasty, the graftaugmented technique has limits regarding the length of the stricture. Palminteri and colleagues [5] first described the use of a combined ventral and dorsal graft in the bulbar urethra reconstruction. The authors observed an excellent success rate of 89.6% in a short-term follow-up. This new approach introduces new concepts about the importance of the urethral plate quality and its preservation during bulbar urethroplasty to treat tight and long strictures. A long-term follow-up is necessary to observe the possible advantages of this new technique against the standard simple graft urethroplasty.

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