Buccal mucosa grafts in hypospadias surgery

Substitution Urethroplasty With Buccal Mucosal Graft in the Management of Stricture of Vesicourethral Anastomosis or Membranous Urethra: Single-institution Long-term Experience With Perineal Approach and Endourethroplasty

OBJECTIVE

To present long-term experience with buccal mucosa posterior urethroplasty (BMPU) for refractory posterior urethral stenosis (PUS) or vesicourethral anastomosis stenosis (VUAS) either by perineal approach (PA) or by endourethroplasty (EUP).

MATERIALS AND METHODS

A single-center retrospective study of 38 consecutive patients operated on between 1999 and 2022. BMPU consisted of the transfer of onlay or tubular buccal mucosa grafts into dilated and/or incised strictures through an open or endourological approach. If VUAS or PUS recurred with short stenosis within the first 12 months after surgery, it was transected by a cold-knife direct vision internal urethrotomy (DVIU), referred to as an "auxiliary" DVIU. The primary outcome was 3-year stricture recurrence-free survival (SRFS).

RESULTS

BMPU by perineal approach and EUP were performed in 27 (71%) and 11 (29%) patients, respectively. The 3-year SRFS was 65% for the whole cohort, with rates of 63% for the perineal approach and 73% for endourological approach. With permitted auxiliary DVIU, 3-year SRFS for the whole cohort was 81%. De novo incontinence occurred in 2 out of 18 preoperatively continent patients. Limitations include the retrospective nature of the single-center study and a small, heterogenous cohort of patients.

CONCLUSION

We present 2 techniques of substitution urethroplasty with BMG in the management of PUS and VUAS with a low rate of recurrence or de novo incontinence. A novel endourological approach (EUP) is a promising minimally invasive alternative to the perineal approach.

MMP-2 and TIMP-2 expression, quantitative analysis and biomechanical changes in scar hypertrophy after autologous free transplantation of rabbit oral mucosa and scrotal skin

This study aimed to investigate the long-term scar hypertrophy in the rabbit transplanted oral mucosa and scrotal skin with changed matrix environment, as well as the scar location expression, quantitative analysis of matrix metalloproteinase-2 (MMP-2) and tissue inhibitor of metalloproteinase-2 (TIMP-2) and biomechanical changes in the transplanted tissues. The split-thickness skin grafts were collected from the oral mucosas and scrotal skins of 30 male rabbits, and prepared into reelpipes for autologous transplantation into the rabbit back muscular tissues. Samples were collected to carry out elastic tensile mechanical detection and histological observation. The maximum longitudinal tensile displacement of scrotal skin before 8 weeks of transplantation was greater than that after 8 weeks of transplantation (P < 0.05). The expression intensities of MMP-2 and TIMP-2 in the oral mucosa and in scrotal skin at 2 W time point were higher than those at T _o time point (P < 0.05). The expression quantities of TIMP-2 in oral mucosa and scrotal skin during 8-24 W were higher than those of MMP-2 (P < 0.05). At 8 W time point, the TIMP-2/MMP-2 ratio in scrotal skin was higher than that in oral mucosa (P < 0.05). MMP-2 and TIMP-2 expression in normal oral mucosa and scrotal skin is weak, but their expression is remarkably up-regulated after 2 weeks of transplantation, revealing that scar formation was related to the high expression of MMP-2 and TIMP-2. At the 8th-24th weeks, the AOD values of TIMP-2 in oral mucosa and scrotal skin are apparently higher than those of MMP-2; moreover, the TIMP-2/MMP-2 ratio in scrotal skin at the 8th week was higher than that in oral mucosa, which can well explain the earlier scar formation in scrotal skin than in oral mucosa, and it also suggests that the different expression levels between TIMP-2 and MMP-2 may account for the important cause of scar formation.

Tunneled buccal mucosa tube grafts for repair of proximal hypospadias

PURPOSE

Buccal mucosa is the favored graft material for patients with long urethral defects and a paucity of skin. Since 2007, we have used the novel tunneled buccal mucosa tube graft urethroplasty technique in these patients. We describe this operative technique and report our surgical and functional outcomes.

MATERIALS AND METHODS

Between 2007 and 2013, 37 males with proximal hypospadias underwent tunneled buccal mucosa tube graft urethroplasty. After the penile shaft was optimized at a prior stage a free buccal graft was tubularized and tunneled under the intact ventral shaft skin and into the glans. We retrospectively reviewed all charts to report our results. We assessed uroflowmetry and bladder ultrasound for post-void residual urine.

RESULTS

The overall complications rate in 34 patients with more than 1-year followup was 32% (11), including fistula in 5, proximal stricture in 4 and meatal stenosis in 2. In the first 10 patients a total of 7 complications (70%) developed but there were only 4 complications in the next 24 (16%). Surgeon experience was the only significant predictor of complications (p = 0.003). We obtained uroflow and post-void residual urine data on 13 of 37 patients, of whom 9 achieved a normal flow pattern and post-void residual urine, and 4 had a blunted flow pattern.

CONCLUSIONS

The novel technique of the tunneled buccal mucosa tube graft in patients with proximal hypospadias represents a good alternative for a long urethroplasty in patients with a paucity of skin. After the learning curve plateaus the rate and degree of complications decrease. Furthermore, voiding function is adequate, as assessed by uroflow studies and post-void residual urine measurement.

Autologous buccal mucosa graft for repair of recurrent rectovaginal fistula

Post-operative pediatric rectovaginal fistulas are rare, can be challenging to repair, and often recur. The versatility, ease of accessibility, vascularization, and likeness to native vaginal tissues make autologous buccal mucosal grafts a novel tissue substitute for the repair of a recurrent rectovaginal fistula after the surgical repair of anorectal malformations.

[Surgical treatment options in bulbar urethral stenosis]

OBJECTIVE

To review the outcome of bulbar urethroplasty using two stage surgical techniques.

MATERIAL AND METHODS

Twenty-two of the 35 patients studied corresponded to end-to-end urethroplasty (ATT) and 13 to dorsal onlay graft (DOG) in preputial skin or oral mucosa variants. Clinical outcome was considered a failure when postoperative surgery was needed or the uroflowmetry was less than 15ml/s. The following variables were studied: age, previous surgery, number of urethrotomies and stricture length. The curves and log-rank Curves using the log-rank were elaborated for follow-up and comparison, with the Cox regression model for risk factors.

RESULTS

Mean follow-up was 40.02 months. Of all the cases. 85.71% were successful. Of these, 86.36% were in the ATT group and 84.61% in the DOG group. There were no significant differences in the comparative LR test based in stricture length, previous surgery between both group and individualized for each management. The Cox regression model showed a risk of failure in the technique for the elderly patients (OR 2.2), it not achieving statistical significance in the remaining variables.

CONCLUSIONS

The success rate achieved with the ATT technique is verified a gold standard option in short strictures. The DOG is shown as a valid option in long strictures in bulbar urethral in medium follow-up, using a oral mucosa or preputial onlay graft. More long-term follow-up must be performed with a greater number of patients to better evaluate these results.

Initial experience with lingual mucosal graft urethroplasty for anterior urethral strictures

BACKGROUND

To present the feasibility of lingual mucosal graft urethroplasty in anterior urethral strictures and appraisal of donor site morbidity.

METHODS

From November 2007 to December 2010, 14 patients underwent dorsal onlay lingual mucosal graft urethroplasty for anterior urethral strictures. Lingual mucosal graft was harvested from the lateral and undersurface of the tongue. Check micturating cystourethrograms were done 2 weeks after catheter removal and uroflowmetry after 3 months. Success was defined as normal uroflowmetry rates at 3 months in the absence of any postoperative instrumentation. Tongue was assessed for any residual pain, taste disturbances or restricted movement at 3 months.

RESULTS

Four patients had submucosal fibrosis of the oral cavity and their buccal mucosa was unfit for grafting. Mean (range) stricture length was 5 (3-16) cm and the operation time 170 (140-210) min. Graft width averaged 1.6 cm. Average length of harvested graft was 6.5 cm. Mean duration of follow-up was 12.8 months. Two patients developed stricture at the proximal anastomotic site. There were no donor site complications.

CONCLUSIONS

Lingual mucosal graft harvesting is simple, gives graft lengths comparable to buccal mucosa and is associated with negligible donor site morbidity.

Management of severe hypospadias

Many classifications of hypospadias have been published, mainly based on the position of the ectopic meatus, which is an insufficient criterion to define the severity of this malformation. What really marks the proximal landmark of this malformation is the level of division of the corpus spongiosum, which is always proximal to the ectopic meatus. In this article, we will focus on the most severe forms of hypospadias which include those with a proximal division of corpus spongiosum (below the midshaft), important chordee and a poor development of the ventral radius, reflecting a marked hypovirilization of the genital tubercle, and cripple hypospadias resulting from several previous failed surgical procedures. The principle of hypospadias surgery will be reviewed together with the outcome of the current surgical techniques. Furthermore, common complications will be outlined. There is no minor or major hypospadias and all forms require a solid experience of the surgeon, as minor looking hypospadias may turn out to be far more complex to repair than they appear once the ventral radius of the penis has been dissected.

Urethral strictures

What's known on the subject? and What does the study add? Urethral strictures are common and increasingly common in an ageing population. The treatment is controversial and particularly the relative roles of urethrotomy or urethral dilatation on the one hand and urethroplasty on the other. This review aims to provide a comprehensive overview of the subject including less commonly discussed issues such as the history and pathology of stricture disease. We would hope that a comprehensive overview of the subject will give a sharper perspective to aid the investigation and management of patients with urethral strictures.

Outcome analysis of tubularized incised urethral plate using dorsal dartos flap for proximal penile hypospadias repair

PURPOSE

To assess the outcome of tubularized incised plate (TIP) urethroplasty in conjunction with a dorsal dartos flap for primary proximal penile hypospadias.

MATERIALS AND METHODS

Forty-nine patients with proximal penile hypospadias underwent a one-stage TIP urethroplasty with single-layer closure using polyglactin suture. A dorsal dartos (subcutaneous) flap, harvested from the dorsal penile shaft was used to cover the neourethra ventrally. Glanuloplasty was also performed in all cases. All patients had a well preserved urethral plate after straightening of the penis. Complications and cosmetic appearance were documented during follow-up.

RESULTS

Mean patient age at surgery was 23 months (16-72 months). Mean operative time was 180 min (154-240 min). At the mean follow-up of 36 months, the overall complication rate was 12% (4 fistulae, 1 meatal stenosis). Glandular dehiscence occurred in one patient, and 38 patients (78%) required dorsal Nesbit plication. No patient had residual chordee, neourethral stricture or a urethral diverticulum, and the neomeatus with a slit-like appearance was positioned at the glans tip.

CONCLUSIONS

TIP urethroplasty with dorsal dartos layer covering the neourethra is an effective treatment for primary proximal penile hypospadias with a preserved urethral plate and without severe curvature. There is a good cosmetic outcome with low risk of complications.

Hypospadias

Hypospadias results from abnormal development of the penis that leaves the urethral meatus proximal to its normal glanular position anywhere along the penile shaft, scrotum, or perineum. A spectrum of abnormalities, including ventral curvature of the penis (chordee), a hooded incomplete prepuce, and an abortive corpora spongiosum, are commonly associated with hypospadias. Advances in understanding of the causes of hypospadias and current approaches to the correction of hypospadias to provide a cosmetically and functionally satisfactory repair are the focus of this article.

Upper transverse scrotal approach for muscle- and nerve-sparing urethral stricture repair

OBJECTIVE

Open surgery on bulbar urethral strictures has become a widespread procedure. While there is inconsistency which procedure to perform at the bulbar region, there is consistency of the used incisional approach despite of several potential disadvantages. Therefore, to bypass disadvantages, we performed an upper transverse scrotal approach for stricture repair in the pendulous urethra and the distal bulbar urethra as previously reported for the placement of an artificial urinary sphincter.

METHODS

Thirteen patients (n = 13) with bulbar urethral stricture were operated by upper transverse scrotal incision approach. On five patients a free foreskin graft in dorsal onlay technique was performed. Eight patients obtained an end-to-end-anastomosis procedure. Pre- and postoperative uroflowmetry as well as retrograde urethrocystography were done. Pre- and postoperative residual postvoid urine were estimated by transabdominal ultrasound. The patients were followed-up for up to 12 months.

RESULTS

After stricture repair, Qmax improved from mean 9.0 mL/s (SD +/- 3.2) preoperatively to mean 20.3 mL/s (SD +/- 3.1), postoperatively. Postvoid residual urine decreased from mean 90.0 mL (SD +/- 68.7) to mean 41.5 mL (SD +/- 16.1). All retrograde urethrocystographies showed regular reconstructed urethral conditions.

CONCLUSION

The upper transverse scrotal incision may combine the advantages of a less traumatical approach with the excellent results of perineal approach.

The oral mucosa graft: a systematic review

PURPOSE

We provide the reader with a critical, nonbiased, systematic review of current and precedent literature regarding the use of oral mucosa in the reconstruction of urethral defects associated with stricture and hypospadias/epispadias.

MATERIALS AND METHODS

We reviewed pertinent English literature from January 1966 through August 1, 2006 via the databases MEDLINE/PubMed, the Cochrane Library, and EMBASE Drugs and Pharmacology regarding the use of oral mucosa graft urethroplasty in the reconstruction of urethral defects associated with stricture and hypospadias/epispadias. Bibliographies of pertinent articles were explored for additional important literature.

RESULTS

Data were stratified among studies that only used oral mucosa graft urethroplasty in the reconstruction of urethral defects associated with stricture, and those that used oral mucosa graft urethroplasty in the reconstruction of urethral defects associated with hypospadias/epispadias. Recipient site success in the reconstruction of defects associated with stricture was significantly associated with the location of graft placement (ventral vs dorsal, p <0.001) when an onlay graft was used. Hypospadias/epispadias recipient site success was significantly associated with the type of graft used (tube vs onlay, p <0.001), and by the site of oral mucosa harvest (labial vs buccal, p <0.001). Other perioperative and patient oriented variables were not significantly associated with success at the recipient site.

CONCLUSIONS

The oral mucosa is a viable source of donor tissue displaying many characteristics of the ideal urethral graft. There are numerous variations of the oral mucosa graft urethroplasty technique. Herein comparisons are made.

Tubularized incised plate urethroplasty for hypospadias reoperations in 100 patients

OBJECTIVES

To determine the key points for a successful redo hypospadias procedure using tubularized incised plate urethroplasty operation.

METHODS

A retrospective chart review of a cohort of 100 patients (Mean age: 4.5 years, range: 2-12) who had undergone a redo tubularized incised plate urethroplasty operation was performed. Fischer exact and Chi square tests were used for statistical analysis.

RESULTS

The incidence of complications of tubularized incised plate urethroplasty reoperation after failed repairs of meatal advancement and glanuloplasty procedure (n: 14), meatal based flap (n: 36), and tubularized incised plate urethroplasty (n: 50) were 29% (n: 4), 22% (n: 8) and, 28% (n: 14) respectively (P > 0.05). The overall complication rate was 26% (n: 26). Eighteen patients (18%) had fistula, five had meatal stenosis (5%), two had dehiscence (2%) and one had neourethral stenosis (1%). Postoperatively, fistula was closed in 18 patients and 5 underwent meatoplasty. Two patients with dehiscence and one with neourethral stenosis underwent an unsuccessful third redo tubularized incised plate urethroplasty reoperation and they were candidates for a complex hypospadias repair (3%). The ultimate success rate of tubularized incised plate urethroplasty reoperation after treatment of complications was 97%.

CONCLUSION

Tubularized incised plate urethroplasty is a safe and efficacious alternative procedure for hypospadias reoperations if the urethral plate has no scars and outcome is favourable if the first failed hypospadias repair is a meatal based flap procedure. The complication rate increases if the urethral plate has been previously incised in the midline and a redo third redo must be avoided.

A New Option for the Management of Urethral Trauma: Primary Reconstruction of Posterior Urethral Disruption with a Buccal Mucosa Transplant

Up to now, the management of traumatic posterior urethral disruption ranges from primary realignment to delayed urethroplasty. However, we reconstructed the membranous part of the urethra with an onlay graft of buccal mucosa after traumatic complete disruption as a first line therapy. After 7 months followup, the clinical outcome is very good. Because primary reconstruction of the urethra with a buccal mucosa graft after traumatic disruption has not yet been reported, the question arises whether this technique should be routinely included as an option for primary urethral reconstruction after trauma of the posterior urethra.

Komplizierte Harnröhrenrekonstruktionen bei Erwachsenen und Kindern

The urethral reconstruction is a challenge in the adult, but even more in infant and young male patients. Good knowledge of the anatomy of the penis (blood supply and the course of the nerve fibers) with the availability of microsurgery suturing and instruments improved the outcome significantly. The growing knowledge opened the possibility to reconstruct complicate strictures with grafts. The buccal mucosa flap is one of those improvements, which made a tremendous impact to have a successful outcome. Recently we looked into the outcome of urethral reconstruction of long urethral strictures by using a buccal mucosa only flap. We used a modified technique for hypospadias repair to reconstruct coronar or subcoronar defects by meatal mobilization (MEMO). In cases with a long urethral stricture the success rate was over 90% with a mean follow up of 16 months. In all children the outcome with the MEMO-technique was successful without any major complication with a mean follow-up of 12.5 months.

Hypospadias

Hypospadias results from abnormal development of the penis that leaves the urethral meatus proximal to its normal glanular position anywhere along the penile shaft,scrotum, or perineum. Hypospadiology is an evolving and expanding discipline that remains at the forefront of pediatric surgical innovation. Although modern experiments have begun to yield a deeper understanding of the genetic, hormonal, and environmental basis of hypospadias, the quest for a surgical procedure that consistently results in a straight penis with a normally placed glanular meatus has challenged surgeons for over two centuries. This article focuses on the advances in the understanding of the etiology of hypospadias and the current approaches to the correction of hypospadias.

Urethral substitution using an intestinal free flap: a novel approach

PURPOSE

Patients who have extensive stricture disease, those in whom hypospadias repair fails and those who sustain significant urethral trauma pose a reconstructive challenge for genitourinary surgeons. We developed an additional reconstructive option for men with a severely diseased urethra when grafting procedures and local tissue flaps have failed or are otherwise contraindicated.

MATERIALS AND METHODS

A genitourinary reconstructive team performed novel intestinal free flap substitution urethroplasty in 2 patients. A segment of jejunum is harvested on a vascular pedicle and plicated into an appropriate size urethral substitute. Microvascular anastomoses allow this segment to remain viable and functional. The technical aspects of repair and surgical considerations are detailed.

RESULTS

The 2 patients have a satisfactory functional and cosmetic outcome. At short followup the urethral lumen remained patent and the intestinal urethra remained viable and intact. Both patients have good urinary streams and are able to void in the standing position.

CONCLUSIONS

This initial experience in 2 patients indicates that intestinal segment urethral substitution may be considered within the reconstructive armamentarium of genitourinary surgeons when more conventional options have failed or are contraindicated. Continued vigilant followup is necessary to detail any secondary complications. In addition, further experience with this technique by other surgeons would help determine its overall usefulness.

Treatment of urethral defects: skin, buccal or bladder mucosa, tube or patch? An experimental study in dogs

PURPOSE

We studied 3 graft materials and 2 urethroplasty techniques in 24 adult male mongrel dogs.

MATERIALS AND METHODS

The animals were divided into 2 equal groups. In group 1 a 4 cm. segment of perineal urethra was excised and tubed urethroplasty was performed using free full-thickness skin, buccal and bladder mucosa grafts in 4 dogs each. In group 2 a 4 cm. urethral strip was excised and onlay urethroplasty was performed using the same graft materials in 4 dogs each. Retrograde urethrography was done and the animals were sacrificed at week 12. Autopsy specimens were calibrated with a 10Fr catheter. Hematoxylin and eosin stained sections were examined. Masson's trichrome stain was used to determine the extent of fibrosis.

RESULTS

Urethral stricture was diagnosed by radiology and confirmed by calibration in 8 of the 12 dogs (66%) in group 1 but in only 1 of the 12 (8%) in group 2 (p <0.004). Buccal mucosa grafts were associated with the lowest stricture rate of 12%, followed by 37% for bladder mucosa and 62% for skin (p <0.2). There was no difference in neovascularization among the 3 grafts. Graft shrinkage was less than 10% for buccal mucosa compared with 20% to 40% for skin and bladder mucosa. The shrinkage rate was similar for the onlay and tube techniques. The intensity of chronic inflammation and fibrosis was highest in the skin grafts. Circumferential fibrosis was noted in association with tubed urethroplasty but not with the onlay technique.

CONCLUSIONS

The theoretical advantages of buccal mucosal grafts were pathologically demonstrated. When possible, grafts should be used as an onlay rather than as a complete tube.

Buccal mucosal grafts: lessons learned from an 8-year experience

PURPOSE

We evaluated our 8-year experience with buccal mucosal grafts in complex hypospadias and epispadias repair.

MATERIALS AND METHODS

We reviewed the records of 29 patients in whom a total of 30 buccal mucosal grafts were placed as part of urethral reconstruction between 1991 and 1999. At surgery 16 tubes and 14 onlays were constructed and 24 of 30 repairs involved the meatus. All patients were followed at least 6 months postoperatively (median 5.3 years). Beginning in 1995 meatal design was enlarged to a racquet handle shape and patients were asked to perform meatal self-dilation for 6 months postoperatively.

RESULTS

Complications developed in 17 of our 30 cases (57%) and reoperation was done in 10 (33%). All complications were evident by 11 months postoperatively except 1 that presented as recurrent stricture disease at 3 years. Complications developed in 5 and 12 of 15 patients who underwent surgery between 1995 and 1999, and before 1995, respectively (p = 0.027). No patient has had meatal stenosis since 1995. Complications included meatal stenosis in 5 cases, stricture in 7, glanuloplasty, meatal and complete graft breakdown in 1 each, and fistula in 2. Onlays were more likely to result in stricture than tube grafts (6 of 14 cases versus 1 of 16, p = 0.034).

CONCLUSIONS

The complication and reoperation rates of buccal mucosal grafts are 57% and 33% at 5 years of followup. Changes in meatal design and temporary postoperative meatal dilation have improved the outcome in the last 5 years. Buccal mucosa remains a good choice in patients who require extragenital skin for urethral reconstruction.

Intraoral wound closure with tissue-engineered mucosa: new perspectives for urethra reconstruction with buccal mucosa grafts

In urethra reconstruction, the creation of a new urethra from a free oral mucosa graft is an established surgical technique. The oral mucosa is removed at the same time that the urethra reconstruction procedure is performed. Depending on the size of graft required, the intraoral wound is closed primarily or left to heal secondarily. The latter method limits this technique by leading to scars or strictures, which have a negative impact on the condition of the intraoral soft tissue. Therefore, in this study, a pilot study involving 12 patients, tissue-engineered mucosa was tested for covering intraoral defects to avoid the drawbacks mentioned above. For mucosa tissue-graft engineering, a biopsy sample 2 to 4 mm in diameter was removed from the hard palate approximately 4 weeks before the urethra reconstruction procedure was to be performed. In addition, 30 ml of autogenous serum was extracted from a venous whole-blood sample. The primary cultures were incubated in Dulbecco modified Eagle's medium and nutrient factor F 12 (Gibco Co., Eggenstein, Germany), containing the usual additives and autogenous serum. After a period of 3 weeks, subcultivation was performed to engineer mucosa transplants consisting of several layers of keratinocytes on a support foil. After thorough intraoperative blood coagulation had occurred, the cultured mucosa graft on the carrier foil was applied on the wound surface and fixed by single sutures. Additionally, the cultured mucosa graft was covered for 8 to 10 days by an intraoral dressing, which was also fixed onto the wound surface by single suture loops. It is possible to perform primary intraoral wound closure with tissue-engineered mucosa to cover defect sizes as large as 11.0 x 4.0 cm. This new method provides a better prospect for both urethra reconstruction and the reconstruction of intraoral tissue defects. The number and size of intraoral scars and strictures are diminished. This is of special interest for the reconstruction of the functional unit oral cavity, including soft tissue and cosmetic conditions (e.g., in case of prosthetic rehabilitation). In comparison to primary wound closure with local tissue, the technique presented in this study reduces the severity of postoperative pain and allows faster rehabilitation in patients because of a better wound-healing process. Furthermore, better mobility of intraoral soft tissue structures is achieved.

Buccal mucosal grafts for urethral reconstruction

OBJECTIVES

Patients requiring urethral reconstruction but who have a paucity of usable genital tissue present a considerable technical challenge. Herein we report the experience of three centers in the use of buccal mucosa for urethral replacement.

METHODS

From 1991 to 1996, 22 urethral reconstructions were completed using a graft of buccal mucosa. Eighteen of 22 patients had previously failed hypospadias repairs, while three had bulbar urethral stricture and one had penile carcinoma. Grafts were taken from either the inner cheek or the lower lip, and seven were used as a combined graft. Onlay grafts were used in 6 cases and tubularized grafts in 16 cases.

RESULTS

Two patients developed complications at the donor site. Nine of 22 patients had complications of the urethroplasty-two had meatal stenosis, four developed a urethral fistula, and three developed urethral stricture. All complications have been managed successfully to date.

CONCLUSIONS

Buccal mucosa is an excellent source of graft material for urethral replacement in complex urethroplasties. It is readily available, in abundant supply, and has physical properties beneficial to free graft survival.

Urethral replacement with vascularized tunica vaginalis: defining the optimal form of use

PURPOSE

Residual urethral defects after failed hypospadias surgery present difficulties in reconstruction. In these situations, repair using vascularized tissue flaps remains ideal, yet challenging. In order to offer more surgical alternatives in these cases, the use of vascularized tunica vaginalis flaps as urethral replacements has recently been established in an animal model. We undertook the following studies to further define the role of tunica vaginalis in urethral reconstruction.

MATERIALS AND METHODS

A vascularized flap of tunica vaginalis was used to replace an experimentally created 25-30 mm. gap in the anterior urethra of 26 rabbits, either as an onlay or tube flap. A control group consisting of 7 animals underwent only a segmental anterior urethral resection and primary re-anastomosis.

RESULTS

Satisfactory urethral healing occurred in all control animals that survived the procedure. All 8 animals which had tunica vaginalis tube flap reconstruction underwent contracture of the neourethra probably secondary to the presence of striated cremasteric muscle elements brought with the tunica during mobilization. All 16 animals available for long term study in the onlay flap group had excellent flap viability and 100% urethral patency rates. The mesothelial lining of the tunica was seen to be replaced by a stratified epithelial lining similar to the urothelial lining of the native urethra.

CONCLUSION

The tunica vaginalis is a viable alternative to other tissues presently used for urethral replacement and can be used successfully as a vascularized onlay flap.