The histology and immunohistochemistry of free buccal mucosa and full-skin grafts after exposure to urine

Histological Comparison of Buccal and Lingual Mucosa Grafts for Urethroplasty: Do They Share Tissue Structures and Vascular Supply?

Comparable outcomes were published using a buccal mucosa graft (BMG) from the cheek and a lingual mucosa graft (LMG) from the sublingual area, for urethral augmentation or substitution. To date, no histological comparison between both grafts has been conducted. We histologically assessed BMG and LMG harvested during urethral surgeries, aiming to compare graft properties and vascular support. We conducted a prospective single cohort study, including oral mucosa urethroplasty patients. During surgery, graft dimensions and donor sites were collected, and a 0.5 × 0.5 cm sample was obtained from the prepared graft. Formalin-fixed paraffin-embedded samples were sliced at 4 micrometres (µm) and hematoxylin-eosin stained. Using a telepathology tool, all slides were digitalized and measured from 10× to 40× magnification. In each graft, global and individual layers thicknesses were assessed, including vascular density and area. Descriptive and comparative (parametrical and non-parametrical) statistical analysis occurred. We collected 57 grafts during 33 urethroplasties, with 30 BMG and 22 LMG, finally, included. The mean age was 56.6 (SD 15.2) years, and the mean graft length was 5.8 (SD 1.7) cm and the width was 1.7 (SD 0.4) cm. The median graft thickness was 1598.9 (IQR 1200–2100) µm, the mean epithelium layer was 510.2 (SD 223.7) µm, the median submucosa was 654 (IQR 378–943) µm. the median muscular was 477.6 (IQR 286–772) µm, the median vascular area was 5% (IQR 5–10), and the median adipose tissue area was 5% (IQR 0–20). LMG were significantly longer and narrower than BMG. Total graft thickness was similar between LMG and BMG, but the epithelium and submucosa layers were significantly thinner in LMG. The muscular layer was significantly thicker in LMG. Vascular density and vascular areas were not significantly different between both types of grafts. LMG showed significantly less adipose tissue compared with BMG. Our findings show LMG and BMG for urethroplasty surgeries share the same thickness and blood supply, despite having significantly different graft sizes as well as mucosal and submucosal layers thickness.

Evaluation of the Extent of Primary Buccal Mucosal Graft Contracture in Augmentation Urethroplasty for Stricture Urethra: A Prospective Observational Study at a Tertiary Healthcare Centre

Introduction

Buccal mucosal graft (BMG) urethroplasty is considered as gold standard in the treatment of urethral stricture disease. The successful outcome after BMG urethroplasty varies between 66 and 99%. One of the possible causes for failure is BMG contracture. Primary BMG contracture rate is poorly understood and unreported. The present study aimed to evaluate the extent of contracture of buccal mucosa immediately after harvesting.

Materials and Methods

This was a prospective observational study conducted in the Department of Urology at our institute between January 2016 and December 2019. All patients with urethral stricture disease undergoing BMG urethroplasty for the first time were enrolled in the study after obtaining informed consent. Demographic and patient clinical profile was noted. Based on the intraoperative urethral stricture size, the preharvest graft was marked on the buccal mucosa and the size was calculated. Postharvest unstretched size of the graft was measured immediately after graft removal from the oral cavity. Alteration in BMG size was analysed using paired t-test.

Results

Forty-four patients were included in the study. Mean age of the patient was 53.6 years. Mean stricture length was 7.45 cm (range 4–12 cm). Mean pre- and postharvest BMG size was 8.3 × 1.5 cm and 7.6 × 1.3 cm, respectively. There was a 8.4% decrease in length and 9.5% decrease in width of the buccal mucosal graft.

Conclusion

Primary buccal mucosal graft contracture is around 8.4% in length and 9.5% in width. It would be better to mark wider than necessary while harvesting buccal mucosa so that tension-free anastomosis is performed.

Frontiers in urethra regeneration: current state and future perspective

Despite the positive achievements attained, the treatment of male urethral strictures and hypospadiases still remains a challenge, particularly in cases of severe urethral defects. Complications and the need for additional interventions in such cases are common. Also, shortage of autologous tissue for graft harvesting and significant morbidity in the location of harvesting present problems and often lead to staged treatment. Tissue engineering provides a promising alternative to the current sources of grafts for urethroplasty. Since the first experiments in urethral substitution with tissue engineered grafts, this topic in regenerative medicine has grown remarkably, as many different types of tissue-engineered grafts and approaches in graft design have been suggested and testedin vivo. However, there have been only a few clinical trials of tissue-engineered grafts in urethral substitution, involving hardly more than a hundred patients overall. This indicates that the topic is still in its inception, and the search for the best graft design is continuing. The current review focuses on the state of the art in urethral regeneration with tissue engineering technology. It gives a comprehensive overview of the components of the tissue-engineered graft and an overview of the steps in graft development. Different cell sources, types of scaffolds, assembling approaches, options for vascularization enhancement and preclinical models are considered.

Single-stage tubular urethral reconstruction using oral grafts is an alternative to classical staged approach for selected penile urethral strictures

Penile urethral strictures have been managed by a staged surgical approach. In selected cases, spongiofibrosis can be excised, a neo-urethral plate created using buccal mucosa graft (BMG) and tubularized during the same procedure, performing a “two-in-one” stage approach. We aim to identify stricture factors which indicate suitability for this two-in-one stage approach. We assess surgical outcome and compare with staged reconstruction. We conducted an observational descriptive study. The data were prospectively collected from two-in-one stage and staged penile urethroplasties using BMG in a single center between 2007 and 2017. The minimum follow-up was 6 months. Outcomes were assessed clinically, radiologically, and by flow-rate analysis. Failure was defined as recurrent stricture or any subsequent surgical or endoscopic intervention. Descriptive analysis of stricture characteristics and statistical comparison was made between groups. Of 425 penile urethroplasties, 139 met the inclusion criteria: 59 two-in-one stage and 80 staged. The mean stricture length was 2.8 cm (single stage) and 4.5 cm (staged). Etiology was lichen sclerosus (LS) 52.5% (single stage) and 73.8% hypospadias related (staged). 40.7% of patients had previous failed urethroplasties in the single-stage group and 81.2% in the staged. The most common stricture locations were navicular fossa (39.0%) and distal penile urethra (59.3%) in the single-stage group and mid or proximal penile urethra (58.7%) in the staged group. Success rates were 89.8% (single stage) and 81.3% (staged). A trend toward a single-stage approach for select penile urethral strictures was noted. We conclude that a single-stage substitution penile urethroplasty using BMG as a “two-in-one” approach is associated with excellent functional outcomes. The most suitable strictures for this approach are distal, primary, and LS-related strictures.

Buccal Mucosa Tube Graft for Failed Hypospadias Repair: Worth it or Not?

OBJECTIVE

To report the outcome of buccal mucosa tube graft (BMTG) over time in correcting failed hypospadias.

METHODS

We conducted a retrospective analysis, reviewing charts of all 69 patients who underwent BMTG to repair hypospadias between January 2005 and October 2016. Twenty-one patients were excluded, leaving 48 eligible study subjects. In patients with penile curvatures, corrective procedures (including urethral division, corporoplasty, and local skin flap) took place prior to grafting.

RESULTS

Mean age at surgery was 8.96 years, and mean duration of follow-up was 73.10 ± 30.31 months. A mean of 1.88 previous surgeries was recorded. During follow-up, only 7 patients (14.5%) were complication free. The other 41 patients required at least 1 additional procedure. Stricture-free rates were 50%, 35.4%, and 27% at 1, 3, and 12 months after BMTG, respectively. Among 37 patients with postoperative stricture, 25 were treated only by endoscopic procedures. Single operation prior to BMTG (P= .004) and usage of larger catheter size (>8Fr) (P = .029) were confirmed significant factors associated with better stricture-free survival after BMTG by log-rank test. After several additional procedures, 46 patients (95.8%) reported normal urination with mean maximal urinary flow of 9.55 mL/s and post-void residual of 16.08 mL for at least 12 months on last visit.

CONCLUSION

BMTG after failed hypospadias repair seems prone to complications, primarily urethral stricture. However, a large number of patients with postoperative stricture could be treated simply by endoscopic procedures. Given the better results of staged approach, BMTG should be only applied to highly selected patients with failed hypospadias.

A new technique for ureteral reconstruction using lingual mucosa grafts in a beagle model

PURPOSE

To investigate the feasibility of ureteral reconstruction using lingual mucosa graft (LMG) and evaluate the histological changes of the engrafted LMG in beagles.

METHODS

Twelve male beagle dogs were randomly divided into groups A, B and C (n = 4). A ventral ureteral defect was created by excising half of the ureteral wall. The length of the defect was 3 cm, 6 cm, and 10 cm in groups A, B, and C, respectively. The LMGs were harvested and employed to repair the ureteral defects in onlay fashion. Two dogs per group were sacrificed after 6 months, with additional two dogs per group sacrificed after 12 months. Intravenous urography (IVU) and macroscopic examination were performed to evaluate renal function and ureteral patency. Histological changes in the engrafted LMGs during the tissue incorporation process were assessed by histological analysis.

RESULTS

There were no postoperative complications. Only one dog in group C developed a mild stricture near the proximal anastomosis. In the remaining 11 animals, IVU showed normal renal function and a wide ureteral caliber without stricture or fistula. The diameter of the LMG-reconstructed ureter was greater than that of the proximal and distal ureter (each p value < 0.01). The LMGs survived in situ with newly formed capillaries. The epithelium of the lingual mucosa resembled the urothelium in postoperative 12 months.

CONCLUSION

This new technique for ureteral reconstruction using LMGs is feasible. This approach is a promising alternative clinical treatment for curing long ureteral strictures.

Vacuum physiotherapy after first stage buccal mucosa graft (BMG) urethroplasty in children with proximal hypospadias

INTRODUCTION

To assess the feasibility of vacuum physiotherapy meant to decrease graft contraction and recurrent penile curvature (PC), hence successful tubularization and a straight penis in patients underwent two-stage buccal mucosa graft (BMG) urethroplasty, in proximal hypospadias repair.

MATERIAL AND METHODS

Between January 2014 and July 2018, 59 two-stage BMG urethroplasties performed at our referral center, were included in the study. The parents were counseled to use the vacuum device between the two stages. An internal, self-administered, semiquantitative, non-validated questionnaire was designed to record parent and patient adherence to the vacuum physiotherapy and parent satisfaction. Success rate of graft tubularization, curvature correction rates, and status of early (4 months) postoperative urinary stream were evaluated.

RESULTS

Of 45/59 (76.3%) who returned the questionnaire, 77.8% followed the recommended physiotherapy protocol using the vacuum device. 93.3% of parents replied that the use of the vacuum was easy or moderately easy. None of the parents interrupted the physiotherapy because of perceived difficulty or intolerability. 100% of parents would have repeated the physiotherapy, if they had to. Overall, success rate of tubularization was 98.3% (58/59), complete curvature correction was achieved in 88.2% (52/59) of patients, and 79.7% (47/59) of patients showed a straight and powerful early post-operative urinary stream.

CONCLUSIONS

Physiotherapy with the vacuum device is safe, easy and practically feasible. Our vacuum physiotherapy protocol had high compliance rate. Vacuum physiotherapy should be considered for further assessment in patients undergoing two stage hypospadias repair using buccal mucosa.

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.

Onlay Repair Technique for the Management of Ureteral Strictures: A Comprehensive Review

Ureteroplasty using onlay grafts or flaps emerged as an innovative procedure for the management of proximal and midureteral strictures. Autologous grafts or flaps used commonly in ureteroplasty include the oral mucosae, bladder mucosae, ileal mucosae, and appendiceal mucosae. Oral mucosa grafts, especially buccal mucosa grafts (BMGs), have gained wide acceptance as a graft choice for ureteroplasty. The reported length of BMG ureteroplasty ranged from 1.5 to 11 cm with success rates of 71.4%-100%. However, several studies have demonstrated that ureteroplasty using lingual mucosa grafts yields better recipient site outcomes and fewer donor site complications than that using BMGs. In addition, there is no essential difference in the efficacy and complication rates of BMG ureteroplasty using an anterior approach or a posterior approach. Intestinal graft or flap ureteroplasty was also reported. And the reported length of ileal or appendiceal flap ureteroplasty ranged from 1 to 8 cm with success rates of 75%-100%. Moreover, the bladder mucosa, renal pelvis wall, and penile/preputial skin have also been reported to be used for ureteroplasty and have achieved satisfactory outcomes, but each graft or flap has unique advantages and potential problems. Tissue engineering-based ureteroplasty through the implantation of patched scaffolds, such as the small intestine submucosa, with or without cell seeding, has induced successful ureteral regeneration structurally close to that of the native ureter and has resulted in good functional outcomes in animal models.

Histopathological changes in oral mucosa in cases of failed augmented urethroplasty

OBJECTIVE

Histopathological changes in oral (buccal or lingual) mucosa after exposure to urine are still not completely understood. We evaluated these changes in free oral mucosal graft integrated in human urethra.

MATERIAL AND METHODS

Total 19 patients with recurrent urethral stricture after oral mucosa urethroplasty (buccal 12 and lingual 7) were prospectively evaluated. Intraoperatively integrated buccal or lingual mucosal graft sample that was previously engrafted to urethra was completely excised along with healthy oral mucosa, and it was sample processed for histopathological evaluation by dedicated pathologist. Preoperative clinical data were properly collected from all the study participants.

RESULTS

The mean age of the patients was 30 years, and the mean preoperative peak flow rate was 4.2 mL/s. Etiology of initial stricture was idiopathic in 13 (68.42%) patients and traumatic urethral catheterization in 6 (31.58%) patients. Mean interval from previous buccal mucosal urethroplasty to current urethroplasty was 21.9 months (range 12-46 months). On repeat urethroplasty, the mean stricture segment length was 59.2 (38-77) mm [60.08 (38-74.6) mm buccal, and 58.32 (39.6-77) mm lingual]. These integrated oral mucosal grafts maintained their histopathological characteristics in all patients except some kind of changes like submucosal fibrosis in seven (58.33%) cases of buccal and vacuolar degeneration in five (71.42%) cases of lingual mucosal urethroplasty.

CONCLUSION

Histopathological characteristics of integrated oral (buccal and lingual) mucosal grafts were maintained even on exposure to urine except some changes like submucosal fibrosis and vacuolar degeneration. Impact of these changes require further research.

Robotic Buccal Ureteroplasty: a Review of the Current Literature

PURPOSE OF REVIEW

This study aimed to provide an overview of the literature on buccal mucosal ureteroplasty for ureteral stricture disease, with a specific focus on the application of the robotic platform to buccal ureteroplasty.

RECENT FINDINGS

In our review, we highlight the results of Zhao et al. from the New York University School of Medicine Department of Urology, as well as our own results from Temple University Hospital. Zhao et al. published the first series of four patients who underwent robotic buccal ureteroplasty. Mean stricture length was 3.0 cm, and at a mean follow-up of 15 months, all repairs remained patent. We also describe our results in 10 patients who underwent robotic buccal ureteroplasty at Temple University Hospital. Median stricture length was 3.0 cm, and at a median follow-up of 5 months, all repairs remain patent. Robotic buccal ureteroplasty offers a promising option for repair of complex ureteral strictures.

Use of Bipedicled Dorsal Penile Flap With Z Release Incision: A New Option in Redo Hypospadias Surgery

OBJECTIVE

To solve the challenge in redo hypospadias surgery, we tried to use a bipedicled dorsal penile flap with a Z release incision in failed hypospadias cases and reported the outcome.

MATERIALS AND METHODS

Thirty male children with 3 or 4 previous unsuccessful hypospadias surgeries were included in our study. Our technique was done after at least 6 months from the last surgery. A flap of the dorsal penile skin was preserved and the skin lateral to the flap was dissected on each side. A small opening was done in the dartos proximal to flap. The glans was withdrawn through this opening with a ventral transposition of the flap. Z-plasty was used to compensate for the deficient dorsal skin; the Z-plasty had 3 limbs and all were made of equal length.

RESULTS

The mean age of the patients was 5.4 ± 1.8 years and the mean follow-up was 2.1 ± 0.7 years. The technique was successful in 80%. Reoperation was required in 3 cases; all cases were managed using a 2-stage buccal mucosal graft. A small fistula at the coronal level developed in 2 cases but closed spontaneously within 1 month. All patients were voiding well and had a vertically oriented meatus at the tip of the glans and satisfactory cosmetic results.

CONCLUSION

Repair of failed hypospadias using a bipedicled dorsal penile skin flap with Z release incision is a safe and simple procedure offering high success rates.

Management of penile urethral strictures: Challenges and future directions

The anatomy of the penile urethra presents additional challenges when compared to other urethral segments during open stricture surgery particularly because of its unsuitability for excision and primary anastomosis and its relatively deficient corpus spongiosum. Stricture aetiology, location, length and previous surgical intervention remain the primary factors influencing the choice of penile urethroplasty technique. We have identified what we feel are the most important challenges and controversies in penile urethral stricture reconstruction, namely the use of flaps vs grafts, use of skin or oral mucosal tissue for augmentation/substitution and when a single or a staged approach is indicated to give the best possible outcome. The management of more complex cases such as pan-urethral lichen-sclerosus strictures and hypospadias “cripples” is outlined and potential developments for the future are presented.

Prelamination of Neourethra with Uterine Mucosa in Radial Forearm Osteocutaneous Free Flap Phalloplasty in the Female-to-Male Transgender Patient

Radial forearm free flap phalloplasty is the most commonly performed flap for neophallus construction in the female-to-male (FtM) transgender patient. Urological complications, however, can arise quite frequently and can prevent the patient from urinating in the standing position, an important postsurgical goal for many. Using mucosa to construct the fixed urethra and to prelaminate the penile urethra has been successful in reducing urologic complications, particularly strictures and fistulas. Until now, only buccal, vaginal, colonic, and bladder sites have been described as sources for these mucosal grafts. We present the successful use of uterine mucosa for prelamination of the neourethra in an FtM patient who underwent hysterectomy and vaginectomy at the prelamination stage of a radial forearm phalloplasty. Three months postoperatively, the patient was able to void while standing and showed no evidence of stricture or fistula on retrograde cystogram. These results suggest that uterine mucosa may be used for prelamination of the penile neourethra in patients undergoing phalloplasty.

Buccal mucosal graft interposition in the treatment of recurrent vesicovaginal fistula: A report on two cases

OBJECTIVE

To present the use of autologous buccal mucosa graft (BMG) in the treatment of recurrent vesicovaginal fistula (VVF).

CASE REPORTS

In 2011, two women, aged 45 years and 56 years, were admitted due to recurrent VVF. Both women had previously undergone abdominal hysterectomies for benign conditions and, subsequently, vaginal VVF repair due to vaginal urine leakage. On admission, the younger woman had a round fistula, with a diameter of 1.5 cm, located on the left side, supratrigonally; the other woman had an ellipsoidal fistula measuring 2.5 cm × 1.5 cm, located medially and supratrigonally. Both women underwent suturing of the VVF with the interposition of BMG. After the last treatment, both women were cured.

CONCLUSION

Treatment of recurrent VVF with the interposition of BMG is a good alternative to the use of other tissue grafts. Larger series are needed to confirm the advantages of this method.

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.

Histopathological characteristics of buccal mucosa transplants in humans after engraftment to the urethra: a prospective study

PURPOSE

Histopathological changes in buccal mucosa transplants after engraftment to the urethra and exposure to urine remain nebulous. We investigated histopathological changes in buccal mucosa transplants integrated into the urethra in humans.

MATERIALS AND METHODS

We prospectively evaluated 22 patients with recurrent urethral stricture after buccal mucosa urethroplasty between November 2012 and October 2013. All patients underwent repeat buccal mucosa urethroplasty performed by a single surgeon. Intraoperatively we harvested a sample of the integrated buccal mucosa transplant previously engrafted to the urethra, a sample of healthy urethra, a sample of freshly harvested buccal mucosa from the contralateral inner cheek and a sample of fibrotic tissue from the area of the current stricture. A dedicated uropathologist performed meticulous histopathological examination of all tissue samples using hematoxylin and eosin staining. Preoperative clinical data were also collected on all patients.

RESULTS

The mean interval from previous to current buccal mucosa urethroplasty was 22.2 months (range 4.1 to 76.0). Mean stricture length at repeat urethroplasty was 52.7 mm (range 30.0 to 70.0). Histopathological characteristics of the integrated buccal mucosa transplants were completely preserved in all patients, consisting of thick sheets of stratified nonkeratinized squamous epithelium with a stratum spinosum. Transplants were not partially or entirely overgrown with urothelium.

CONCLUSIONS

Buccal mucosa transplants retain their histopathological characteristics and are not overgrown with urothelium after urethral engraftment and urine exposure in humans. These findings may explain the superiority of buccal mucosa transplants on the outcome of substitution urethroplasty compared to that of other materials.

[Management and prevention of complications in open urethral surgery. End-to-end anastomosis and buccal mucosa urethroplasty]

Open operative procedures for urethral reconstruction (i.e. stricture resection with primary end-to-end anastomosis and buccal mucosa urethroplasty) are established and proven techniques with a low complication profile and high success rates. The aim of this operative technique is removal of the urethral obstruction to avoid far-reaching complications for the whole urinary tract. Despite excellent long-term results, complications are not completely avoidable in both techniques. A successful complication management requires the complete spectrum of reconstructive techniques in addition to appropriate operative expertise in order to be able to achieve the optimal result even in cases of complications. Simultaneously the recognition of potential risks contributes to a further reduction of early and delayed complications both in the approach to the operative intervention as well as intraoperatively.

Distinct phenotype and therapeutic potential of gingival fibroblasts

Gingiva of the oral mucosa provides a practical source to isolate fibroblasts for therapeutic purposes because the tissue is easily accessible, tissue discards are common during routine clinical procedures and wound healing after biopsy is fast and results in complete wound regeneration with very little morbidity or scarring. In addition, gingival fibroblasts have unique traits, including neural crest origin, distinct gene expression and synthetic properties and potent immunomodulatory functions. These characteristics may provide advantages for certain therapeutic approaches over other more commonly used cells, including skin fibroblasts, both in intraoral and extra-oral sites. However, identity and phenotype of gingival fibroblasts, like other fibroblasts, are still not completely understood. Gingival fibroblasts are phenotypically heterogeneous, and these…fibroblast subpopulations may play different roles in tissue maintenance, regeneration and pathologies. The purpose of this review is to summarize what is currently known about gingival fibroblasts, their distinct potential for tissue regeneration and their potential therapeutic uses in the future.

Use of buccal mucosa in hypospadias repair

Hypospadias is an embryological disorder that results in an abnormal ventral positioning of the urethral meatus. Among multiple surgical techniques described to correct this anomaly, the use of buccal mucosa grafts has gained popularity among pediatric urologists, pediatric surgeons and plastic surgeons. Buccal mucosa grafts have shown favorable histological changes that result in an excellent scaffold for urethral reconstructive surgery. This review describes the evolution of the use of buccal mucosa grafts in hypospadias repair.

[Oral mucosa for reconstructive urethral surgery]

The use of oral mucosa for urethral stricture repair has become the standard approach in reconstructive urethral surgery. Compared to other tissues oral mucosa shows several advantages, such as simple harvesting, good urine tolerance and low harvesting morbidity. For defects of the male bulbar urethra measuring 2 cm or longer, urethral reconstruction with oral mucosa is the procedure of choice. The oral mucosa graft can be used as an inlay or as an onlay graft. Most repairs can be completed in one stage but for complex strictures two stages are needed.

Urethra reconstruction with a prelaminated pedicled anterolateral thigh flap: a case report

We present a case report of urethral reconstruction with a pedicled anterolateral thigh flap prelaminated with bladder mucosa in sex reassignment. The successful outcome may make this technique worthy to be considered in the secondary reconstruction of urethra in difficult cases. To the best of the authors' knowledge, no similar case has been previously described.

Long-term angiogenic activity of free grafts and pedicle flap in a rabbit urethroplasty model

PURPOSE

We studied the late angiogenic activity of free grafts and a pedicle flap in a rabbit urethroplasty model to determine whether angiogenic activity plays a role in late outcomes of urethral reconstruction in rabbits.

METHODS

Twenty-eight rabbits were randomly divided into five groups according to the method used to bridge a urethral defect as an onlay patch: Control, simple closure of urethral defect (Group O1); free penile skin graft (FPSG, Group A1); buccal mucosal graft (BuMG, Group B1); bladder mucosal graft (BlMG, Group C1); and pedicle penile skin flap (PPSF, Group D1). Angiogenic activity of the patch on postoperative day 84 was assessed by immunohistochemistry.

RESULTS

The angiogenic activity in Groups O1, A1, B1, C1, and D1 was 23.33 ± 4.92 (means ± SD), 42.89 ± 6.52, 55.78 ± 3.46, 53.61 ± 6.17, and 24.11 ± 9.07 vessels per optical field, respectively. There were statistically significant differences (p < .001) between Group O1 and A1 B1, C1, Group A1 and B1, C1, D1, Groups B1 and D1 and Groups C1 and D1, but not between Groups O1 and D1 (p = 1.000) and Groups B1 and C1 (p = .872). The long-term angiogenic activity of all the groups was significantly lower (p < .001) than in the corresponding early groups.

CONCLUSIONS

Although the angiogenic activity of all the groups decreased in the late assessment, the buccal mucosal graft continued to exhibit elevated angiogenesis above bladder or skin (free or pedicle) graft. Therefore, buccal mucosal patch graft might be preferable because of its easier harvesting.

Aptness and complications of labial mucosa grafts for the repair of anterior urethral defects in children and adults: single centre experience with 115 cases

PURPOSE

We report a comprehensive review of our experience with labial mucosa graft urethroplasty to evaluate the indications for this kind of substitution urethroplasty, and the possible complications and risk factors for an untoward recipient site outcome both in children and adults.

MATERIALS AND METHODS

Complications were retrospectively assessed by chart review. Patients with and without complications were compared with respect to age at surgery, indication for surgery (epispadias vs. hypospadias vs. urethral stricture), graft length and configuration (tube vs. patch). Moreover, in cases with urethral stricture a comparison was made according to the level of the stricture (penile vs. bulbar).

RESULTS

After a median follow-up of 36 (6–90) months, the overall success rate was 66%. Complications were observed in 39 (34%) patients, of whom 18 (16%) required additional surgical procedures. Complications appeared to be unrelated to patient age at surgery, indication for surgery, graft length, and the urethral level of the stricture. Use of the graft as a tube was the single factor significantly more frequent in patients experiencing complications, particularly in the urethral defects associated with hypospadias where use of a tube corresponded to an odd ratio of 5.86 (95% CI 1.5–23.4).

CONCLUSIONS

Oral grafts harvested from the lower lip are a versatile tissue for the repair of urethral defects associated with either urethral malformations or strictures, both in children and adults. Use of the graft as an on-lay seems preferable particularly in hypospadias repairs.

Treatment of long ureteric strictures with buccal mucosal grafts

OBJECTIVE

To describe the reconstruction of long ureteric strictures using buccal mucosal patch grafts and to report the intermediate-term functional outcome.

PATIENTS AND METHODS

Between November 2000 and October 2006 reconstruction of seven long ureteric strictures using buccal mucosal patch grafts and omental wrapping was performed in five women (one with bilateral strictures) and one man. The surgical steps of stricture reconstruction and wrapping with omentum are described in detail. Stricture recurrence was defined as persistent impaired ureteric drainage as displayed by imaging techniques or the necessity to prolong JJ stenting. Patency rates and stricture recurrence-free survival rates are provided.

RESULTS

With a median follow up of 18 months five of the seven strictures were recurrence-free. Graft take was good in all patients. In one asymptomatic patient, there was impaired ureteric drainage on the reconstructed side, and in one patient with reconstruction of both ureters prolonged JJ stenting of one side was necessary. In both patients, the impaired drainage was caused by persistent stricture below the reconstructed ureteric segments.

CONCLUSIONS

At intermediate-term follow-up in a small group of patients with long ureteric strictures, treatment with buccal mucosal patch grafts and omental wrapping showed good functional outcome.

Reconstruction of the urethra with a Surgisis onlay patch in urethral reconstructive surgery: two case reports

INTRODUCTION

We present two case reports of patients with recurrent stricture of the urethra. We used Surgisis((R)) for reconstruction.

CASE PRESENTATION

In these two case reports, we show the positive results of reconstructive surgery with Surgisis((R)) as an alternative surgical approach to common onlay patch surgery of the urethra performed on two Caucasian patients: a 48-year-old man and a 55-year-old man.

CONCLUSION

Compared to buccal mucosa flap or foreskin graft surgeries for urethral reconstruction, reconstructive surgery with Surgisis((R)) is considered a relevant therapeutic alternative because of the shorter operation time and the preventable surgery of the buccal cavity or foreskin.

Donor site outcome after oral mucosa harvest for urethroplasty in children and adults

PURPOSE

We report short and long-term donor site outcomes after oral mucosa graft harvesting for urological reconstruction in a large series of patients including children, and identify possible risk factors for an untoward long-term outcome.

MATERIALS AND METHODS

A total of 78 patients were evaluated. Short-term outcomes included time to restore normal oral diet, perioral sensory defect/discomfort and jaw opening impairment occurring within 4 weeks of surgery. Long-term outcomes included donor site scarring, perioral sensory defect and jaw opening impairment occurring more than 1 year postoperatively. Long-term outcomes were assessed via a questionnaire administered to patients and on clinical examination by an oral surgeon. Outcomes were compared in children (younger than 12 years at surgery) and adults, and with regard to harvesting site, graft length, length of followup and other variables.

RESULTS

Two-thirds of the patients returned to a normal oral diet within 3 days postoperatively (range 1 to 8). All patients complained of perioral sensory defect/discomfort postoperatively, and 26% had jaw opening impairment. After a median followup of 7.6 years (range 1 to 13.2) perioral sensory defect was the most common complication observed (28%) in cases formally evaluated by an oral surgeon. The sensory defect was seldom perceived by the patients and never required treatment. It was statistically more common in patients undergoing surgery as adults, whereas none of the other variables proved significant.

CONCLUSIONS

Oral mucosa graft harvesting is safe irrespective of age. About a quarter of patients, more commonly adults, will have a long-term perioral sensory defect. However, the defect is never perceived as bothersome.

The multistage use of buccal mucosa grafts for complex hypospadias: histological changes

PURPOSE

We report our experience using buccal mucosa in the multistage repair of complex hypospadias, and the observed histological changes.

MATERIALS AND METHODS

We evaluated 31 patients (14 adults and 17 children). A total of 19 patients presented after failed hypospadias repair with deficient ventral skin, 5 presented with scrotal hypospadias and 7 presented with perineal hypospadias. Patients who had previously undergone hypospadias repair had 3 to 7 failed trials. Two stage buccal mucosa graft was performed using the Bracka technique. In the first stage residual fibrosis was released, the glans was split and the buccal mucosa graft was sutured to the ventral surface of the penis to form a future urethral plate. Second stage reconstruction was performed after 6 months with interposed scrotal dartos tissue. Buccal mucosa was histologically studied before grafting, and at 6 months after graft uptake and exposure to the air.

RESULTS

Buccal mucosa free graft showed excellent uptake within 5 days in all cases. At 6 months the buccal mucosa was well vascularized and pliable. Minute fistulas occurred in 3 cases (9.7%), which were closed at a later stage. Histological analysis of buccal mucosa tissues before and after graft and prolonged exposure to the air (more than 6 months) was conducted. The buccal mucosa displayed epithelial hyperplasia with mild and focal keratinization. The lamina propria was slightly edematous and minimally infiltrated by mononuclear inflammatory cells. The lamina propria papillae were elongated, extending to 75% of the mucosal thickness compared to the normal buccal mucosa. The buccal mucosal graft displayed good vascularization, similar to that of the normal mucosa.

CONCLUSIONS

Multistage repair using buccal mucosa is an excellent option for urethral reconstruction. It guarantees excellent graft uptake and good vasculature, which improves success. It also provides supple tissue for glanular and urethral reconstruction in cases of severe complex hypospadias.

[In vitro three-dimensional reconstruction of human bladder mucosa]

OBJECTIVE

The purpose of this study is to apply the in vitro keratinocyte culture techniques and the tissue engineering principles to human urothelium, to reconstruct an in vitro three-dimensional human bladder mucosa, suitable for grafting.

MATERIAL AND METHODS

Biopsy specimens of human bladder mucosa were obtained from patients undergoing suprapubic prostatectomy, in vitro cultured and finally, an immunohistochemical study was made.

RESULTS

A three-dimensional in vitro tissue was obtained, composed of a bio-artificial submucosa (fibrin gel and fibroblast) where the uroepithelial cells were seeding. We used a biodegradable polyglycolic acid mesh to facilitate the tissue manipulation and implantation. An immature epithelium was obtained with a weak immunostaining to cytokeratins. The immunohistochemical study could not demonstrate the development of basement membrane.

CONCLUSIONS

In vitro keratinocyte culture techniques could be applied to other epithelial tissues like the urothelium. We obtained a three-dimensional in vitro tissue suitable for grafting in a relatively short time, which needs the matrix interactions in order to mature.

[Urethral strictures--operative strategy]

Urethral strictures are very commonly encountered in urologists' day-to-day work. Many specific therapeutic and reconstructive procedures are available for treatment of the different types of urethral stricture, all of which can be recommended when the indications for each are carefully observed. This paper highlights operative concepts that allow a surgical therapy that is tailored to the localisation and length of the stricture and the severity of spongiofibrosis.

Long-term outcome of ventral buccal mucosa onlay graft urethroplasty for urethral stricture repair

OBJECTIVES

To evaluate our patients who were treated with ventral buccal mucosa onlay grafts for open urethral stricture repair with a follow-up exceeding 5 years. Buccal mucosa onlay is widely used for urethral reconstruction; however, the long-term outcome of these patients remains unclear.

METHODS

During the past 10 years, 67 patients underwent ventral buccal mucosa onlay graft surgery for urethral stricture repair. Of these, 32 were followed up for longer than 5 years (mean 6.9 years) for the occurrence and timing of any postoperative complications. All patients had undergone prior internal urethrotomy (mean 2.9 procedures), and the average length of the stricture was 4.3 cm (range 3 to 17).

RESULTS

The overall complication rate was 25% (8 of 32). We observed one fistula, one graft infection/necrosis, two lower lip scars with transient impairment of lip motility, and four recurrent strictures (at the proximal anastomosis), all of which were treated successfully with internal urethrotomy. All but one recurrent stricture occurred during the first 12 postoperative months.

CONCLUSIONS

Ventral buccal mucosa onlay grafting for urethral stricture repair provides stable long-term results with complications occurring primarily during the first 12 postoperative months.

Long-term followup of buccal mucosa onlay graft for hypospadias repair: analysis of complications

PURPOSE

We review the long-term results of buccal mucosa onlay grafting for urethral reconstruction in hypospadias surgery in patients with followup of at least 5 years.

MATERIALS AND METHODS

We retrospectively evaluated 132 patients who underwent buccal mucosa onlay graft for hypospadias repair, including 34 who underwent "salvage" grafting, during a 10-year period at our institution. In 49 cases with available followup longer than 5 years (average 6.2) complications were analyzed in detail.

RESULTS

The overall complication rate was 24% (12 of 49 patients), with all but 3 complications occurring during the first postoperative year (3 fistulas, 1 stricture, 1 meatal stenosis, 2 graft contractures, 2 scars at oral harvesting site). The remaining 3 complications manifested during postoperative years 2 and 3, and encompassed 2 anastomotic strictures at the proximal anastomosis and 1 meatal stenosis.

CONCLUSIONS

Buccal mucosa onlay grafts for urethral reconstruction in hypospadias repair seem to provide stable long-term results, with complications occurring primarily during the first 12 months postoperatively.

Ventral onlay urethroplasty using buccal mucosa for complex stricture repair

OBJECTIVES

To report the short to medium-term results of one-stage buccal mucosa ventral onlay in the treatment of recurrent urethral stricture disease.

METHODS

Between April 1997 and July 2001, buccal mucosa was used as a ventral onlay graft in 38 patients with recurrent strictures of the bulbar (n = 30) and proximal penile urethra (n = 8). All patients had undergone at least 1 urethrotomy (range 1 to 10; mean 2.9) before reconstruction. Prospective follow-up included a simple questionnaire on patient satisfaction, uroflowmetry, and ultrasound estimation of postvoid residual urine volume and, in the case of recurrence, retrograde urethrography and cystoscopy.

RESULTS

The primary success rate at a mean follow-up of 22.8 months (range 8.7 to 40.7) was 80%. Stricture recurred in 7 patients, mostly within 12 months. A distinct residual irregularity at the former stricture site in the initial postoperative urethrogram was predictive of failed reconstruction. A second procedure was performed in 4 patients (1 urethrotomy and 3 re-buccal mucosa onlay grafts) with good results. Patient satisfaction was high in most instances. Three patients refused reoperation, preferring regular intermittent dilation.

CONCLUSIONS

When end-to-end anastomosis is impossible, onlay urethroplasty using buccal mucosa is a rather simple alternative with encouraging short to medium-term results in the proximal segments of the male urethra.