Substitution urethroplasty using oral mucosa graft for male anterior urethral stricture disease: Current topics and reviews

Male anterior urethral stricture is scarring of the subepithelial tissue of the corpus spongiosum that constricts the urethral lumen, decreasing the urinary stream. Its surgical management is a challenging problem, and has changed dramatically in the past several decades. Open surgical repair using grafts or flaps, called substitution urethroplasty, has become the gold standard procedure for anterior urethral strictures that are not amenable to excision and primary anastomosis. Oral mucosa harvested from the inner cheek (buccal mucosa) is an ideal material, and is most commonly used for substitution urethroplasty, and lingual mucosa harvested from the underside of the tongue has recently emerged as an alternative material with equivalent outcome. Onlay augmentation of oral mucosa graft on the ventral side (ventral onlay) or dorsal side (dorsal onlay, Barbagli procedure) has been widely used for bulbar urethral stricture with comparable success rates. In bulbar urethral strictures containing obliterative or nearly obliterative segments, either a two‐sided dorsal plus ventral onlay (Palminteri technique) or a combination of excision and primary anastomosis and onlay augmentation (augmented anastomotic urethroplasty) are the procedures of choice. Most penile urethral strictures can be repaired in a one‐stage procedure either by dorsal inlay with ventral sagittal urethrotomy (Asopa technique) or dorsolateral onlay with one‐sided urethral dissection (Kulkarni technique); however, staged urethroplasty remains the procedure of choice for complex strictures, including strictures associated with genital lichen sclerosus or failed hypospadias. This article presents an overview of substitution urethroplasty using oral mucosa graft, and reviews current topics.     

舌黏膜与颊黏膜或包皮拼接重建尿道治疗长段尿道狭窄

目的 探讨舌黏膜与颊黏膜或包皮拼接尿道成形治疗多节段或长段尿道狭窄的安全性和治疗效果.方法 尿道狭窄患者11例,年龄24～56岁,平均32岁.其中前尿道长段狭窄7例,狭窄长度10～15 cm,平均12 cm;尿道2～3处狭窄4例.病程6个月～8年.取舌黏膜条与颊黏膜条拼接尿道成形治疗7例,舌黏膜条与包皮瓣拼接尿道成形治疗4例.结果 11例手术顺利.1例舌黏膜与包皮拼接尿道成形患者术后3个月并发尿道外口狭窄,经手术矫正后排尿通畅,术后8个月最大尿流率27.5 ml/s.余10例排尿通畅、尿线粗,术后随访5～12个月,平均10个月,最大尿流率21～36 ml/s,平均26.8 ml/s.结论 舌黏膜与颊黏膜或包皮拼接尿道成形具有取材方便、患者创伤小的特占点,是治疗长段尿道律窄的较好术式.尤其适用于尿道多处狭窄者.     

口腔内黏膜尿道成形治疗前尿道狭窄10年经验总结

目的 探讨口腔内黏膜尿道成形治疗尿道狭窄的长期效果. 方法 2001年1月至2010年12月,应用口腔内黏膜(颊黏膜和舌黏膜)尿道成形治疗前尿道狭窄255例.尿道狭窄段长度3 ～18 cm,平均6 cm.尿道成形采用保留原尿道板的扩大尿道成形术或埋藏黏膜条背侧替代尿道成形术.对49例尿道狭窄段≥8 cm者采取双侧颊黏膜拼接、颊粘膜与舌黏膜拼接或双侧连续长条舌黏膜尿道成形. 结果 术后随访8 ～120个月,平均37个月.230例患者排尿通畅,尿线粗,最大尿流率为16～51 ml/s,平均26 ml/s.尿道造影显示重建段尿道管腔通畅.总成功率90.2％.25例患者于术后1年内发生并发症,其中尿道再次狭窄17例,尿道皮肤瘘8例.17例尿道再狭窄患者中15例再次行口腔内黏膜尿道成形,2例吻合口狭窄行尿道内切开,术后排尿通畅;8例尿道皮肤瘘均接受尿瘘修补术后治愈. 结论 口腔颊黏膜和舌黏膜均是良好的尿道替代物,舌黏膜取材较颊黏膜更为便利;口腔内多种黏膜的组合移植重建尿道是治疗长段前尿道狭窄( ≥8 cm)的有效方法.     

Adult anterior urethral strictures: a national practice patterns survey of board certified urologists in the United States

PURPOSE: We determined the methods and patterns of the evaluation of and treatment for adult anterior urethral stricture disease by practicing urologists in the United States. MATERIALS AND METHODS: A nationwide survey of practicing members of the American Urological Association was performed by a mailed questionnaire. A total of 1,262 urologists were randomly selected from all 50 states, of whom 431 (34%) completed the questionnaire. RESULTS: Most urologists (63%) treat 6 to 20 urethral strictures yearly. The most common procedures used by those surveyed for urethral strictures were dilation (92.8%), optical internal urethrotomy (85.6%) and endourethral stent (23.4%). Minimally invasive procedures are used more frequently that any open urethroplasty technique. Furthermore, most urologists (57.8%) do not perform urethroplasty surgery. When used, the most common urethroplasty surgeries performed were end-to-end anastomotic urethroplasty, perineal urethrostomy and ventral skin graft urethroplasty. Few urologists (4.2%) performed buccal mucosa grafts. For a long bulbar urethral stricture or short bulbar urethral stricture refractory to internal urethrotomy 20% to 29% of respondents would refer to another urologist, while 31% to 33% would continue to manage the stricture by minimally invasive means despite predictable failure. Of the urologists 74% believed that the literature supports a reconstructive surgical ladder, in which urethroplasty is only performed after repeat failure of endoscopic methods. CONCLUSIONS: Most urologists in the United States have little experience with urethroplasty surgery. Most urologists erroneously believe that the literature supports a reconstructive surgical ladder for urethral stricture management. Unfamiliarity with the literature and inexperience with urethroplasty surgery have made the use of endoscopic methods inappropriately common.     

Stricture repair using free graft

Summary Single stage urthroplasty with an onlay patch graft of penile skin or buccal mucosa is an effective treatment for patients with complex anterior urethral stricture disease. Using buccal mucosa, operative time is substantially reduced by using a two-team approach in which one team harvests the graft from the mouth while a perineal team simultaneously exposes and calibrates the stricture. Excellent results can be expected using grafts urethral substitution in men with refractory bulbar strictures. Focal areas of severe stenosis may be excised from the graft bed. For patients with long or dense strictures, grafts may easily be combined with other tissue transfer techniques.      

Substitution urethroplasty of complex and long-segment urethral strictures: a rationale for procedure selection

OBJECTIVES: We evaluated the applications and outcomes of substitution urethroplasty, using a variety of techniques, in 65 patients with complex, long-segment urethral strictures. METHODS: From January 1995 to December 2005, 65 patients with complex urethral strictures >8cm in length underwent substitution urethroplasty. Of the 65 patients, 43 underwent one-stage urethral reconstruction using mucosal grafts (28 colonic mucosal graft, 12 buccal mucosal graft, and 3 bladder mucosal graft), 17 patients underwent one-stage urethroplasty using pedicle flaps, and 5 patients underwent staged Johanson's urethroplasty. RESULTS: The mean follow-up time was 4.8 yr (range; 0.8-10 yr), with an overall success rate of 76.92% (50 of 65 cases). Complications developed in 15 patients (23.08%) and included recurrent stricture in 7 (10.77%), urethrocutaneous fistula in 3 (4.62%), coloabdominal fistula in 1 (1.54%), penile chordee in 2 (3.08%), and urethral pseudodiverticulum in 2 (3.08%). Recurrent strictures and urethral pseudodiverticulum were treated successfully with a subsequent procedure, including repeat urethroplasty in six cases and urethrotomy or dilation in three. Coloabdominal fistula was corrected only by dressing change; five patients await further reconstruction. CONCLUSIONS: Penile skin, colonic mucosal, and buccal mucosal grafts are excellent materials for substitution urethroplasty. Colonic mucosal graft urethroplasty is a feasible procedure for complicated urethral strictures involving the entire or multiple portions of the urethra and the technique may also be considered for urethral reconstruction in patients in whom other conventional procedures failed.     

Narrative review of penile distal urethroplasties and suggestions for optimizing outcomes

Distal urethral strictures can be a challenging entity for urologists. Endoscopic maneuvers such as optical internal urethrotomies or dilations are even less successful than in other urethral locations and the repeated trauma will increase the scarring which advocates for a urethroplasty as primary option for patient management. Success rates of distal urethroplasties have been lower than those for other urethral strictures due to the anatomy of the distal urethra with a very thin corpus spongiosum associated with decreased mucosal blood supply. Also, the high prevalence of lichen sclerosus in this population with circumferential scarring is often a complicating factor. However, in the past two decades several surgical techniques have been described and further developed which has led to significant improvement in stricture recurrence rates. Meatoplasties are indicated for strictures limited to the meatus and involve opening of the stenotic meatus with subsequent reconstruction of it to minimize spraying of urine. Often, however, distal urethral strictures involve the fossa navicularis and may even extend further proximally. These strictures can be addressed with dorsal or ventral inlay procedures using buccal mucosa graft. In addition or alternatively, skin flaps can be mobilized to increase the urethral diameter. Lastly, multi-stage urethroplasty with buccal mucosa are a very successful approach yet given the high success rates of above mentioned procedures are usually reserved for revision surgery or most severe distal urethral strictures. In the following report, we are describing a variety of surgical techniques and their indication which should allow the practicing urologist to successfully address all encountered distal urethral strictures.     

Buccal mucosal urethroplasty: is it the new gold standard?

Whilst techniques for urethral reconstruction have developed in the past few decades the quest for an ideal substitute continues. We critically review the literature on buccal mucosal grafts for substitution urethroplasty, to determine the efficacy and complications arising from its use. Buccal mucosal grafts have proved to be a versatile substitute for strictures attributable to a wide range of causes. Placing the graft dorsally appears to be more successful than ventrally and was successful in 96% of cases; after treating complex urethral strictures with two-stage procedures about a quarter of patients required a revision after the first stage with fewer complications then when skin was used as a substitute. Thus, buccal mucosa is most likely to become the new gold standard for substitution urethroplasty and longer term results with its use are eagerly awaited.     

Technique of Harvesting Buccal Mucosa for Urethral Reconstruction

Purpose

Buccal mucosa has been used increasingly by urologists for urethral substitution in complex hypospadias repair. We have found buccal mucosa to be useful in reconstruction of bulbar urethral strictures, and describe a simple and reliable technique for harvest.

Materials and Methods

In 11 patients with refractory bulbar urethral strictures a nontubularized onlay patch of buccal mucosa was used for urethral reconstruction. All procedures were done with a 2-team approach in which 1 team (usually an oral surgeon and urologist) harvested the graft from the mouth, while the perineal team simultaneously exposed and calibrated the stricture.

Results

The length of buccal mucosa used ranged from 3.5 to 17 cm. (average 6.4). All patients achieved excellent results. No oral complications were noted, even in patients in whom multiple buccal mucosal grafts were obtained.

Conclusions

With the technique reported, buccal mucosa is a reliable, easily obtained tissue for patch graft urethroplasty. Our 2-team approach decreased operative time considerably.     

应用口腔颊黏膜Ⅰ期修复女童复杂性前尿道缺损(附3例报告)

目的：探索颊黏膜在修复女童复杂性前尿道缺损中的应用价值。方法：采用部分耻骨劈开联合阴道前庭切口，截取相应大小的口腔颊黏膜作管状成形I期修复女童前尿道缺损3例。结果：3例女童术后均排尿通畅，最大尿流率为l9．6—24．4m1／s，平均为20．5m1／s，尿道造影示尿道通畅。结论：口腔颊黏膜具有取材方便、对患者创伤小、抗感染能力强等特性，是一种较好的尿道替代材料，尤其适合尿道狭窄段＜5cm的患者。     

Long-term followup of the ventrally placed buccal mucosa onlay graft in bulbar urethral reconstruction

PURPOSE: We investigate whether the short-term success rate (greater than 90%) of buccal mucosa free grafts in the bulbar urethra is sustained in the long term. MATERIALS AND METHODS: In 60 patients a ventrally placed buccal mucosa graft was used for repair of bulbar urethral strictures. Of these patients 49 had undergone previous attempt at repair (urethroplasty in 4, internal urethrotomy in 45). Mean graft length was 4.8 cm. In 9 patients a distal penile fasciocutaneous flap was also used for repair of concomitant penile urethral stricture. In 8 of the 9 patients the buccal mucosa graft was combined with end-to-end urethroplasty and 2 buccal mucosa grafts were used in tandem in 1. Followup was at least 1 year in all cases (mean 47 months, range 12 to 107). Failure was defined as an obstructive voiding pattern with radiographic or cystoscopic evidence of recurrent stricture. RESULTS: Bulbar stricture repair was successful in 54 patients (90%) and 4 of the remaining 6 responded to 1 internal urethrotomy for a long-term success rate of 97%. Preoperative clinical characteristics were not significantly different between those who experienced success or failure. CONCLUSIONS: Long-term outcome analysis of ventrally placed buccal mucosa onlay grafts for bulbar urethral strictures demonstrates a durable success rate of 90%. This rate can be improved (97%) with the judicious use of internal urethrotomy.     

8 cm以上复杂性尿道狭窄的外科治疗

目的探讨长段尿道狭窄手术方法的选择与疗效。方法对76例尿道狭窄8cm以上的患者采用不同尿道成形术式治疗,其中不同黏膜重建尿道42例（结肠黏膜26例,膀胱黏膜6例,口腔黏膜10例）;带蒂皮瓣一期尿道成形20例;尿道狭窄段切开、二期尿道成形（Johanson术）12例;阴茎段尿道与前列腺部尿道吻合、三期尿道成形术2例。结果术后初期（6个月内）排尿通畅67例（88％）,有并发症者10例。术后1年以上70例,其中获得随访51例,排尿通畅44例,有并发症者8例,其中采用带蒂皮瓣者发生尿道狭窄2例（18％,2／11）;Johanson术者发生阴茎弯曲2例（2／5）,其中1例成形段尿道内毛发生成和结石形成;采用口腔黏膜者发生尿道狭窄1例（1／7）,膀胱黏膜者发生尿道狭窄1例（1／3）,结肠黏膜者发生后尿道狭窄2例（9％,2／23）。结论口腔与结肠黏膜尿道成形对长段尿道狭窄是较理想的术式;结肠黏膜较适合在常规手术治疗失败后或复杂性尿道狭窄10cm以上的治疗。     

口腔颊粘膜Ⅰ期修复复杂性前尿道狭窄(附六例报告)

目的：探索修复前尿道狭窄的新型替代材料和手术方法。方法：将狭窄或闭锁的前尿道于腹侧纵形劈开，采用口腔颊粘膜补片法治疗复杂性前尿道狭窄患者6例7次。结果：患者前尿道修复术后排尿通畅，平均最大尿流率25．8ml／s，尿道造影示尿道通畅，B超提示吻合口愈合良好，瘢痕少，无明显狭窄。结论：口腔颊粘膜取材方便，创伤小，粘膜易存活，抗感染能力强，修复尿道效果好。     

Management of radiation-induced urethral strictures

Radiation as a treatment option for prostate cancer has been chosen by many patients. One of the side effects encountered are radiation-induced urethral strictures which occur in up to 11% of patients. Radiation damage has often left the irradiated field fibrotic and with poor vascularization which make these strictures a challenging entity to treat. The mainstay of urologic management remains an urethroplasty procedure for which several approaches exist with variable optimal indication. Excision and primary anastomoses are ideal for shorter bulbar strictures that comprise the majority of radiation-induced urethral strictures. One advantage of this technique is that it does not require tissue transfers and success rates of 70-95% have consistently been reported. Substitution urethroplasty using remote graft tissue such as buccal mucosa are indicated if the length of the stricture precludes a tension-free primary anastomosis. Despite the challenge of graft survival in radiation-damaged and poorly vascularized recipient tissue, up to 83% of patients have been treated successfully although the numbers described in the literature are small. The most extensive repairs involve the use of tissue flaps, for example gracilis muscle, which may be required if the involved periurethral tissue is unable to provide sufficient vascular support for a post-operative urethral healing process. In summary, radiation-induced urethral strictures are a challenging entity. Most strictures are amenable to excision and primary anastomosis (EPA) with encouraging success rates but substitution urethroplasty may be indicated when extensive repair is needed.     

Substitution urethroplasty for anterior urethral strictures: a critical appraisal of various techniques

OBJECTIVE: To retrospectively compare the outcome of various techniques of substitution urethroplasty. PATIENTS AND METHODS: Between 1989 and 2000, 109 patients (mean age 39.5 years) underwent substitution urethroplasty for recurrent anterior urethral strictures. Between 1989 and 1995 the procedure was by ventral placement of free grafts (bladder mucosa, buccal mucosa, penile skin) or penile skin flaps. From 1995 onwards the flaps and grafts (buccal mucosa) were applied either ventrally or dorsally. Stricture recurrence and the complications associated with each technique were compared. RESULTS: Ventral onlay repairs were associated with a higher incidence of complications than dorsal repairs, e.g. postvoid dribbling (39% vs 23%, P = 0.01), ejaculatory dysfunction (20% vs 5%, P = 0.03) and flap/graft pseudo-diverticulum or out-pouching (26% vs 2.6%, P = 0.01). Superficial penile skin necrosis was significantly more common with the use of penile skin flaps than with free grafts. There was no significant difference in stricture recurrence, erectile dysfunction and residual penile deformity among the various techniques. CONCLUSIONS: Dorsal free graft/flap onlay urethroplasty gives better results than ventrally placed free grafts/flaps. Dorsal onlay buccal mucosal urethroplasty is a versatile procedure and associated with fewer complications than other substitution methods.     

Reconstructive Management with Urethroplasty

To answer the question of which surgical technique represents the most efficient procedure for urethral reconstruction, the most common techniques are described. Depending on stricture length, stricture location, and patient history, suitable techniques are presented. Preoperative examination and intraoperative findings, such as the condition of the urethral plate, guide the choice of technique. Excision and primary anastomosis is the technique of choice in post-traumatic and short strictures. Flaps and free transplants are necessary in longer strictures. In cases of destruction of the urethral plate, two-stage urethroplasties using buccal mucosa or skin grafts are necessary. For decision making about the adequate urethroplasty technique, underlying pathophysiology, previous treatments, stricture length and location, and shape of the urethral plate have to be considered.Patient summaryAfter unsuccessful primary treatment of urethral strictures and in long urethral strictures, open urethroplasties represent the gold standard treatment. Several techniques are available. Selecting the optimal technique depends on preoperative diagnostic evaluation and intraoperative findings.     

Optimal management of the 3- to 6-centimeter anterior urethral stricture

The optimal management of anterior urethral stricture that does not respond to an endoscopic urethrotomy or is found to be unsuitable for excision and anastomotic repair remains controversial. Genital skin island onlay flaps or buccal mucosal grafts are presently the most dependable single stage procedures used for strictures more than 3 cm in length. Nonhirsute penile island fasciocutaneous flaps constitute the most durable substitution technique for pendulous stricture disease, with long-term studies reporting 90% to 96% success. The complex proximal bulb and bulbomenbraneous stricture with a compromised proximal fibrous avascular bed is ideally managed with either a penile or scrotal island flap or some combination of partial urethral excision with a dorsally placed genital skin island. The buccal mucosal onlay graft is a promising addition to this reconstructive paradigm, and early outcomes have been favorable. The graft is presently used for bulbar strictures, avoiding the transsphincteric on pendulous location, or a compromised recipient bed. The present standard of care for proximal bulb strictures is wide bulbospongiosal mobilization, partial urethral excision, a floor strip anastomosis, and placement of an augmenting flap on the graft in a dorsal location.     

Dorsal onlay techniques for urethroplasty

Dorsal onlay graft urethroplasty is a versatile procedure which may be combined with various substitute materials such as preputial skin, buccal mucosa grafts or pedicled flaps. Others substitute materials such as human urethral mucosa from corpses or collagen matrix will be possible in future. The long-term results of a wide series of patients showed a final success rate from 92% to 97%. Any kind of substitution urethroplasty deteriorate over time, and in our series of patients with an extended follow-up from 21.5 to 43 months the success rate of dorsal onlay graft urethroplasty decreased from 92% to 85%. With regard to substitute material concerns (buccal mucosa versus preputial skin) a long-term follow-up is mandatory to establish if buccal mucosa is superior to foreskin as urethral substitute material. At present, the authors currently use both according to patient preference, status of the genital tissues or strictures characteristics.     

Tissue-engineered buccal mucosa urethroplasty-clinical outcomes

INTRODUCTION: Whilst buccal mucosa is the most versatile tissue for urethral replacement, the quest continues for an ideal tissue replacement for the urethra when substantial tissue transfer is needed. Previously we described the development of autologous tissue-engineered buccal mucosa (TEBM). Here we report clinical outcomes of the first human series of its use in substitution urethroplasty. METHODOLOGY: Five patients with urethral stricture secondary to lichen sclerosus (LS) awaiting substantial substitution urethroplasty elected to undergo urethroplasty using TEBM, with full ethics committee support. Buccal mucosa biopsies (0.5 cm) were obtained from each patient. Keratinocytes and fibroblasts were isolated and cultured, seeded onto sterilised donor de-epidermised dermis, and maintained at air-liquid interface for 7-10 d to obtain full-thickness grafts. These grafts were used for urethroplasty in a one-stage (n=2) or a two-stage procedure (n=3). Follow-up was performed at 2 and 6 wk, at 3, 6, 9, and 12 mo, and every 6 mo thereafter. RESULTS: Follow-up ranged from 32 to 37 mo (mean, 33.6). The initial graft take was 100%, as assessed by visual inspection. Subsequently, one patient had complete excision of the grafted urethra and one required partial graft excision, for fibrosis and hyperproliferation of tissue, respectively. Three patients have a patent urethra with the TEBM graft in situ, although all three required some form of instrumentation. CONCLUSIONS: Whilst TEBM may in the future offer a clinically useful autologous urethral replacement tissue, in this group of patients with LS urethral strictures, it was not without complications, namely fibrosis and contraction in two of five patients.     

犬舌黏膜与颊黏膜组合移植重建尿道的实验研究

目的 探讨犬舌黏膜与颊黏膜组合移植替代尿道的可行性和有效性. 方法杂种雌犬7只,平均体质量13 kg,剥离尿道黏膜4 cm×1 cm,取2 cm×1 cm舌侧面黏膜和颊黏膜各1条,拼接后移植至尿道内,恢复尿道黏膜的连续性.术后留置硅胶导尿管1周,拔除尿管后观察排尿情况.1.5～12.0个月后行逆行尿道造影检测实验犬尿道通畅情况,并用10 F尿管证实有无狭窄.随后处死实验犬,测定移植物长度并行病理组织学检查,观察舌黏膜与颊黏膜组合移植至尿道后组织学改变情况. 结果7只实验犬均存活,排尿通畅6只,发生尿道狭窄1只;无尿瘘.移植手术前后舌黏膜和颊黏膜拼接长度分别为(4.00±0.15)和(3.75±0.23)cm,差异有统计学意义(P＜0.05).排尿通畅犬移植黏膜存活良好;舌黏膜与颊黏膜交界处愈合良好,无狭窄发生;光镜下见鳞状上皮呈连续分布,拼接移植黏膜的鳞状上皮与尿道的移行上皮区分明显,移植黏膜的鳞状上:皮有渐被尿道移行上皮替代的趋势.结论 犬舌黏膜和颊黏膜组合移植可替代尿道黏膜并恢复尿道的连续性.