//Interim outcomes of dorsal skin graft bulbar urethroplasty
Interim outcomes of dorsal skin graft bulbar urethroplasty2017-04-05T18:51:37+00:00

Interim outcomes of dorsal skin graft bulbar urethroplasty

 

Uretra, stenosi uretrale

pdf chirurgia uretrale

Authors:
Enzo Palminteri et Al.

Pubblicazione:
THE JOURNAL OF UROLOGY

Volume:
Vol. 172, 1365–1367, October 2004

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

 

 

 

ABSTRACT

Purpose: We update our interim results of bulbar urethroplasty using a skin graft placed on the dorsal urethral surface.

Materials and Methods: A total of 45 patients with an average age of 45 years underwent dorsal onlay skin graft urethroplasty between January 1994 and December 2000. Of the patients 23 had undergone an average of 2.6 prior endoscopic procedures (range 1 to 14). Preoperative evaluation include clinical history, physical examination, retrograde and voiding urethrography, and ultrasonography. In all patients the bulbar urethra was opened along its dorsal surface, the graft was sutured, splayed and quilted to the corpora cavernosa, and the urethra was rotated to cover the graft. In all patients was used penile skin as substitution material. Mean graft length was 4.7 cm (range 2.5 to 11). Three weeks after surgery voiding cystourethrography was performed.

Results: Average followup was 71 months (range 41 to 110). Clinical outcome was considered a failure when postoperative instrumentation was needed, including dilation. Of 45 cases 33 (73%) were classified as successful and 12 (27%) were failures. The 12 failures were treated with internal urethrotomy (1), end-to-end-anastomosis (1), skin graft urethroplasty (2) and 2-stage urethroplasty (6). Six of the 12 initial failures had a satisfactory final outcome. The remaining 6 patients refused further surgical procedures and received a definitive perineal urethrostomy.

Conclusions: Penile skin grafts used as a dorsal onlay for bulbar urethral reconstruction in a homogeneous series of patients showed a tendency to deteriorate with time. Longer followup is required to compare penile skin with buccal mucosa as substitute materials for bulbar urethral reconstruction.
Between 1994 and 1996 we described the technique of dorsal onlay graft urethroplasty.1 The technique evolved from the concept that the corporeal body remains a healthy host to receive a free skin graft.2 Moreover, spread fixation of the graft onto the fixed surface also potentially decreases the chances of graft shrinkage and sacculation.3 Since the inception of dorsal onlay graft substitution, the surgical treatment of anterior urethral stricture disease has continued to evolve with a myriad of newly described techniques. 4 For example, buccal mucosa has now become the graft of choice at multiple centers.5 New substitution material will be available in the future.6 Previous studies of the surgical outcomes of anterior urethral stricture disease have focused on the technical aspects of surgery and long-term results have rarely been reported. 7–9 Similarly we have reported our initial short-term results of dorsal onlay graft urethroplasty.10, 11 Herein we report our interim outcomes using this technique in a homogeneous cohort of patients. This group of similar patients had bulbar stricture without previous open urethroplasty and were treated with identical dorsal onlay graft urethroplasty.

 

PATIENTS AND METHODS

Between January 1994 and December 2000 we repaired 45 bulbar urethral strictures with dorsal skin graft urethroplasty. Mean patient age was 45 years (range 19 to 79). The etiology of stricture was urethritis in 2 cases, instrumentation in 2, trauma in 4, ischemia in 15 and unknown in 22. Patients with lichen sclerosus, failed hypospadias or urethroplasty and stricture extending into the penile or membranous urethra were excluded from study. Of the 45 patients 23 (51%) had undergone previous internal urethrotomy or dilation. The number of previous urethrotomies was 1 to 14 (mean 2.6).
Preoperative evaluation included clinical history, physical examination, and retrograde and voiding urethrography. Sono-urethrography was performed in all patients since 1998. A total of 15 patients (33%) underwent preoperative urethroscopy using a flexible instrument. In all patients dorsal onlay graft urethroplasty was performed using penile skin as a substitution free graft material. Patients undergoing buccal mucosa or extragenital skin graft substitution were not included in this series, nor were patients in whom augmented roof strip anastomosis was performed. Technique. A midline perineal-scrotal incision is made, the bulbocavernous muscles are separated and the bulbar urethra is dissected from the corpora cavernosa. The bulbar urethra is rotated 180 degrees and the dorsal urethral surface is fully opened. In patients with stricture shorter than 4 cm an ovoid strip of skin is harvested from the ventral penile shaft. In patients with stricture longer than 4 cm a double circumferential subcoronal incision is made to harvest a longer preputial skin strip. Mean graft length was 4.7 cm (range 2.5 to 11). The opened urethra is rotated onto the right side and the graft is sutured, splayed and quilted over the corpora cavernosa using 6-zero interrupted stitches. The right urethral margin is sutured on the right side of the graft. The urethra is rotated over the graft and the left side of the  graft is sutured to the left side of the urethra. At the end of the procedure the graft is completely covered by the urethra. A 14Fr silicone catheter is left in place. Three weeks after surgery voiding cystourethrography is done at the time of catheter removal.
Uroflowmetry and urine cultures were repeated every 4 months in year 1 and annually thereafter. When symptoms of decreased force of stream were present or urine flow was less than 14 ml per second, urethrography and urethroscopy were repeated.

 

RESULTS
Clinical outcome was defined as success or failure by the absence of or need for, respectively, a postoperative procedure such as dilation, internal optical urethrotomy or repeat open urethroplasty. Mean followup was 71 months (range 41 to 110). Of 45 cases 33 (73%) were successful and 12 (27%) were failures. There were no significant intraoperative or postoperative complications, such as myocardial infarction, bleeding requiring transfusion or neuronal injuries.
Table 1 shows patient age, graft length, stricture etiology and prior endoscopic treatment in the success and failure groups. In patients with recurrent disease (failure group) ischemia was the cause of stricture in 42% and 58% had undergone prior endoscopic treatment.
Table 2 shows time to failure (range 1 to 5 years). Eight failures (67%) were observed 1 or 2 years after surgery and only 1 (8%) was observed after prolonged followup. In patients with recurrent stricture endoscopic evaluation provided useful information about the extent of disease. Recurrence showed 2 features, namely a white fibrous ring not more than 1 cm long at the anastomotic site or extensive fibrous tissue involving the entire grafted area. Eight of the 12 recurrences involved the entire grafted area and they were initially treated with perineal urethrostomy. Subsequently 2 patients underwent successful closure of the perineal urethrostomy using a buccal mucosa graft according to our original technique.12 Six patients refused further surgical procedures. Two failures were at the distal graft anastomosis and 2 were at the proximal graft anastomosis. Two of these 4 patients were successfully treated with skin graft urethroplasty, 1 was treated with end-to-end anastomosis and 1 was treated with internal urethrotomy. Six of the 12 initial failures had a satisfactory final outcome. The remaining 6 patients received a definitive perineal urethrostomy.

 

DISCUSSION

Followup in our original series of patients undergoing dorsal onlay skin graft urethroplasty for bulbar stricture disease showed a deterioration rate of 100% in the initial report1 but 73% success at a mean of 71 months of followup. This original series consisted of 45 comparable homogeneous patients in whom disease was isolated to the bulbar urethra. These patients underwent an identical surgical procedure performed by a single surgeon (dorsal onlay technique) with the same substitution material (penile skin). Patients with complex disease such as lichen sclerosus, failed hypospadias repair, previous open urethroplasty or penile stricture were excluded. Factors contributing to the success or failure of urethroplasty have previously been identified, including ischemia, patient age and stricture length.11 In our current study dorsal onlay skin graft urethroplasty showed a higher failure rate in patients with urethral stricture due to ischemia (42%) or previous urethrotomies (58%) but patient age and graft length did not influence the final outcome. In a series of 93 patients failed urethrotomy did not influence the long-term outcome of 3 separate urethroplasty techniques, namely endto- end anastomosis, dorsal onlay graft urethroplasty and 2-stage urethroplasty.
The impact of urethrotomy and/or dilation on the success or failure of urethroplasty is controversial. Further studies in large and homogeneous series of patients are necessary to clarify this problem. The repeat stricture rate at 1 to 5 years showed that 67% of re-strictures were observed 1 or 2 years after surgery and only 8% of failures were observed after prolonged followup. The re-stricture rate is higher at the beginning of the learning curve of the surgical technique and some failures were probably due to technical surgical problems. Late restrictures occurring 2 years after surgery may be due to progression of the original disease13 with free graft deterioration.
Recurrence showed 2 different features, namely extensive fibrous tissue involving the grafted area or a fibrous ring not more than 1 cm long at the distal or proximal anastomotic site. We recently observed the same features in patients with re-stricture after bulbar buccal mucosa graft urethroplasty (unpublished data). Other groups have reported the same experience.13 Graft failure at the distal anastomosis, where the corpus spongiosum is less vascular, may represent poor inosculation due to poor graft bed vascularity.13 On the contrary, graft failure at the proximal anastomosis is currently attributable to disease under staging during surgery.12 Moreover, the proximal anastomosis is deep in the bulb and it is a more difficult site technically in which to ensure epithelium-tourothelium placement.13 Further study is necessary to clarify the true etiology (ischemia, suture line or suture material) of this kind of re-stricture.
Some groups have suggested that substitution urethroplasty steadily deteriorates with time, so that by 15 years more than half of the patients require evaluation for further treatment.8 These studies include urethroplasties using different substitution grafts and varying techniques (penile or scrotal flaps, buccal mucosa graft, or genital or extragenital skin grafts).8 The etiology of urethral stricture is also variable, resulting from a plethora of causes such as trauma, inflammation, hypospadias failure or lichen sclerosus.8 Location and length are also important factors in determining the complexity of repair. To evaluate the true incidence of urethral repair deterioration it is necessary to compare the same repair technique using the same substitution material with urethral strictures of similar locations and etiologies.
The aim of this study was not the comparison of outcomes between penile skin and buccal mucosa as substitute materials for urethroplasty. However, recently we reviewed our results of dorsal onlay urethroplasty using a buccal mucosa graft as the substitute material.14 In a homogenous series of 27 patients with bulbar urethral stricture (excluding urethral stricture due to lichen sclerosus or failed hypospadias repair, or stricture extending into the penile or membranous urethra) the buccal mucosa graft provided an 85% success rate at a mean followup of 42 months.
Finally, our technique of followup (subjective symptoms of decreased urinary stream and a maximum flow rate of less than 14 ml per minute) could have missed some recurrent strictures. Urethrography and/or flexible cystoscopy should be performed periodically until 2 years after urethroplasty. We decided to avoid such diagnostic invasive tools because many patients with urethral stricture underwent repeat urethral manipulations and/or invasive radiological tests before surgery. Patients prefer a clinical and noninvasive followup to improve quality of life after urethroplasty. Furthermore, in our experience we sometime recorded that urethrography, which should be suggestive of recurrent stricture, did not affect patient clinical status.

 

CONCLUSIONS

In our experience the success rate of dorsal onlay graft urethroplasty using penile skin showed a definite tendency to deteriorate with time. Success changed from 100% at shortterm followup in 1996 to 73% at medium range followup in 2003. Prolonged followup extending out to 10 and 15 years is necessary to evaluate the ultimate durability of penile skin as substitute material for dorsal onlay graft urethroplasty and compare the results with those of buccal mucosa, which showed better results in a similar group of patients but at shorter followup.

 

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