The anterior vaginal wall is the most common site of initial pelvic organ prolapse. It is estimated that 80% of surgical repairs for vaginal wall prolapse involve the anterior compartment. It is also the most frequent site of operative failure. Reported rates of operative failure have run as high as 40% – much higher than rates of failure after posterior wall repairs.

There are several possible reasons the anterior vaginal wall may be more susceptible to prolapse and more difficult to repair. It could be that the anterior wall is not as well supported by the levator plate that counters the effects of gravity and abdominal pressure. Normally the anterior wall rests horizontally on the posterior wall, and the posterior wall rests on the levator plate. When levator muscles weaken and increasing force is placed on the connective tissue supports, the anterior wall may be the first compartment to fall.

It is also possible that the attachments of the anterior compartment to the pelvic sidewall or to the apex are weaker, or that the anterior wall itself is more elastic or less dense, or perhaps it is more susceptible to damage during childbirth or weakening with aging. For most women, anterior vaginal wall prolapse is probably the result of a combination of these factors.

Management of anterior wall prolapse is consequently a significant challenge – one that has led surgeons to use various graft materials to reduce the rate of failure of transvaginal repair and subsequent prolapse recurrence. Several studies have shown improvements in short-term recurrence rates, but the long-term durability and safety of mesh-reinforced repair is unclear. Clearly we need a more complete assessment of the anatomic and symptomatic efficacy of graft use in transvaginal repair.

At this point in time, the traditional anterior colporrhaphy with attention to apical suspension remains the preferred method for primary repairs. Apical attachment can be accomplished through a sacrocolpopexy, uterosacral ligament suspension, or sacrospinous ligament suspension. Sacrocolpopexy provides both apical support as well as midline support for the anterior wall. For many surgeons, including myself, a sacrocolpopexy is the procedure of choice for women with a cystocele and apical descent.

Anatomy and Evaluation

Understanding pelvic floor anatomy – and the trapezoidal anatomy of the anterior vaginal wall – is critical to understanding the various types of cystocele and their repair. The trapezoidal plane of the anterior wall results from the ventral and more medial attachments near the pubic symphysis and the dorsal and more lateral attachments near the ischial spine. The wall is suspended on both sides to the parietal fascia overlying the levator ani muscles at the arcus tendineus fascia pelvis (ATFP).

The type of cystocele is defined by where there is a break in the fascial attachments to the pelvic sidewall. A loss of lateral attachment causes what we know as a paravaginal defect, or displacement cystocele. The goal of the paravaginal repair, therefore, is to reattach the lateral vaginal walls to the ATFP.

A transverse cystocele occurs when the top of the pubocervical fascia detaches from the cervix or vaginal apex; it is evidenced by the loss of anterior fornix. (When a transverse cystocele occurs following a hysterectomy, the prolapse frequently includes an enterocele and loss of apical support that must also be repaired.) Central or distal cystoceles involve a loss of support near the pubis and tend to manifest as urethral hypermobility.

When one considers the trapezoidal anatomy of the anterior vaginal wall, the importance of restoring apical support is clear. Several studies have shown that variations in cystocele type and severity are often determined by the degree of apical support. Dr. John O.L. DeLancey and his associates, for instance, found that anterior wall prolapse often was due to loss of apical support when prolapse was measured on MRI scans during Valsalva (Am. J. Obstet. Gynecol. 2006;194:1438-43).

In another evaluation – a cohort study of 325 women – investigators similarly found that anterior vaginal wall prolapse was strongly associated with apical prolapse, and concluded that anterior vaginal wall defects that are surgically repaired usually require concomitant repair of the apex (Am. J. Obstet. Gynecol. 2006;195:1837-40).

Just as with posterior vaginal wall prolapse, one must first determine which part of the patient’s support mechanism has failed. A careful physical evaluation must be done to identify the sites of defects and detachments. By supporting the lateral anterior walls at the level of the ATFP with a ring forceps, one can identify paravaginal defects and determine the role of apical failure.

While supporting the apex with a ring forceps, I ask the patient to bear down or cough. If her anterior wall remains in place and her cystocele disappears, I know an apical suspension is needed at the time of surgery. If she still has some relaxation, an apical suspension as well as an anterior colporrhaphy are needed.

One must also understand, just as with posterior vaginal wall prolapse, which symptoms are bothering the patient, if they are related to the physical findings, and if surgical correction of the anatomy will improve her symptoms. Each woman should then be appropriately counseled about the possible impact of prolapse surgery on both bladder and sexual function.

It is a common misperception that most patients with cystoceles also have stress urinary incontinence. Descent of the midvagina under the bladder base may actually reduce the chance of stress urinary incontinence occurring. Instead, voiding dysfunction is more common, as straining and increased abdominal pressure can cause the cystocele to be pushed to the point that it creates an outlet obstruction by kinking or compressing the urethra.

In a review we conducted of 35 women with stage 3 or 4 anterior wall prolapse and elevated postvoid residuals greater than 100 mL on two separate occasions, 31 women (89%) had normal postvoid residuals following reconstructive surgery and correction of their anterior wall prolapse (Am. J. Obstet. Gynecol. 2000;183:1361-4).

Paradoxically, correction of the cystocele can unmask “occult” stress urinary incontinence. Prior to surgery, a full bladder stress test with the prolapse reduced may indicate that the patient is at risk for stress incontinence symptoms after her prolapsed repair. If a sacrocolpopexy is planned, the CARE (Colpopexy and Urinary Reduction Efforts) trial recommends the placement of a Burch colposuspension at the time of surgery, regardless of preoperative urodynamics. Whether this recommendation is true for vaginal repairs is currently unknown.

Preoperative discussions with the patient concerning her risks of incontinence after cystocele repair, the benefits and risks of prophylactic anti-incontinence surgery, and the need for future surgical correction should be had as part of the surgical decision-making process.

Technique for Anterior Colporrhaphy

Traditional anterior colporrhaphy involves plication of the “endopelvic fascia” or fibromuscular layer of the vaginal wall after the vaginal wall is split. Buttressing of the bladder neck with a Kelly plication stitch was originally described by Howard Kelly in 1913.

The anterior vaginal wall is grasped on each side of the midline with Allis clamps. The cuff is grasped if a vaginal hysterectomy has been performed. If the uterus is in situ, the Allis clamps are used to grasp the vagina approximately 1 cm from the cervicovaginal junction, and an initial transverse incision is made.

The anterior wall, between the mucosa and bladder, is injected with 10 cc of vasopressin solution, 20 U in 50 cc of normal saline. This improves hemostasis and hydrodissects the space. A midline incision to within 1-2 cm of the urethrovesical neck is made.

The use of “three-point” traction can help with the dissection of the muscularis. The vagina is then grasped with several Allis clamps. The surgeon’s index finger distends the vaginal wall and allows the surgeon to determine the thickness of the dissection with the Metzenbaum scissors. The assistant can provide countertraction with a tonsil clamp or DeBakey forceps. The fibromuscular layer is split to the level of the inferior pubic ramus. The procedure is repeated on the opposite side of the vagina.

One modification I prefer is to begin the plication at the apex instead of the bladder neck. This way, I avoid the pitfall of stopping short of the apex and leaving a “gap” or weakness in the repair. It is the apical portion of the repair that is most important. I use permanent sutures, preferably 2-0 Ethibond.

If the vaginal wall is the length needed to reach the apical supports, I use a transverse mattress stitch to plicate the fascia. If the vaginal wall needs to be shortened, I use a vertical mattress stitch. This will generally shorten the anterior wall 2-3 cm. For a large cystocele, two layers of plication can be used. The excess vaginal tissue is excised and closed with interrupted or running fine absorbable sutures.

When an apical repair procedure such as uterosacral ligament suspension or sacrospinous ligament suspension is performed in conjunction with anterior colporrhaphy – which is more often than not – the sutures for the apical repair should be placed and held prior to initiating the anterior colporrhaphy.

At the end of the anterior repair, the apical sutures are then incorporated into the vaginal cuff. Regardless of the type of transvaginal suspension, it is beneficial to bring one arm of the suspension suture through the anterior wall of the cuff and the other arm through the posterior cuff. This way, the anterior and posterior walls are brought together and suspended when the suture is tied.

Graft Use

In 2008, the Society of Gynecologic Surgeons (SGS) systematically reviewed the literature and published clinical practice guidelines on vaginal graft use. The SGS group concluded that nonabsorbable synthetic graft use may improve anatomic outcomes of the anterior vaginal wall, but that there are trade-offs in regard to additional risk. While more randomized studies on new mesh products are being conducted and reported, the data simply are insufficient to determine the anatomic or symptomatic efficacy of these types of grafts, the group said (Obstet. Gynecol. 2008;112:1131-42).

Similar to the SGS review, the Cochrane Collaboration completed a systematic review and concluded that the use of mesh or graft inlays at the time of anterior vaginal wall repair may reduce the risk of recurrent cystocele but that there was insufficient evidence to make recommendations for anterior vaginal wall or apical repair (Cochrane Database Syst. Rev. 2010;CD004014 [doi: 10.1002/14651858.CD004014.pub4]).

Overall, the few randomized trials that have been done illustrate the balance of risks and benefits that the surgeon and patient must weigh prior to considering the use of vaginal mesh or graft for the treatment of anterior wall prolapse.

One study that randomized 202 women to anterior colporrhaphy with or without a low-weight polypropylene mesh showed lower recurrence of anterior wall prolapse at 1 year with mesh than without mesh on physical examination using the Pelvic Organ Prolapse Quantification (POP-Q) system, but no differences in patient symptoms.

In this trial, the cure rate 1 year after surgery (defined as POP-Q stage 0 or 1) was significantly higher after the mesh-augmented repair compared with standard anterior colporrhaphy (62% vs. 93%). The use of mesh was, however, associated more often with stress urinary incontinence (23% vs. 10%). There were no differences in symptomatic outcomes such as vaginal bulging or difficulty with bladder emptying as perceived by the women or in reoperation rates 1 year out. Mesh exposure was significant in the augmented group, 17% vs. 0% (Obstet. Gynecol. 2007;110[pt. 2]:455-62).

In a one-surgeon, randomized controlled trial of 38 women who had traditional anterior colporrhaphy and 37 who had polypropylene mesh repair using the Perigee Transobturator Prolapse Repair System, Dr. John N. Nguyen concluded that repair with polypropylene mesh reinforcement offered lower anatomic recurrence rates at 1 year than did anterior colporrhaphy without mesh reinforcement (Obstet. Gynecol. 2008;111:891-8).

In this study, prolapse and incontinence symptoms improved significantly in both treatment groups, and sexual symptom scores did not change significantly in either group.

Overall, the current evidence seems to support the use of synthetic mesh to augment repairs of anterior vaginal prolapse but at the expense of an increased rate of complications, particularly mesh exposure.

In my practice, most recurrent anterior wall prolapses are associated with apical descent as well. In those patients, I recommend a sacrocolpopexy performed laparoscopically. I would reserve the use of transvaginal mesh for women who have recurrent isolated anterior vaginal prolapse with a well-supported apex.

This column, “Master Class,” regularly appears in Ob.Gyn. News, an Elsevier publication. Dr. Fenner is the Harold A. Furlong Professor of Women’s Health and director of gynecology at the University of Michigan, Ann Arbor. She is a nationally recognized expert and lecturer on urogynecology. Dr. Fenner disclosed that she has research funding from AMS in Minnetonka, Minnesota, the maker of the Perigee Transobturator Prolapse Repair System. E-mail her at .

Copyright (c) 2009 Elsevier Global Medical News. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.

阴道前壁是盆腔器官初始脱垂的最常见部位。据估计，80%的阴道壁脱垂手术修补病例都涉及前腔。这也是最容易出现手术失败的部位。据报告，手术失败率现已高达40%，比后壁修补失败的发生率要高得多。

 

阴道前壁更容易出现脱垂也更难修补的原因可能是多方面的。可能是因为前壁不像后壁那样有提肌板的良好支撑因此难以对抗重力和腹压。正常情况下，前壁与后壁相平行，而后壁则直接与提肌板相连。当提肌的力量减弱并且起支撑作用的结缔组织所承受的压力增加时，前壁就可能首先出现脱垂。

 

还有一种解释是，前腔附着于盆腔侧壁或顶部的力量较弱，或前壁本身的弹性就更大或密度更低，也可能是因为前壁在分娩过程中更容易受损或随着年龄的增长更容易变弱。对于大部分妇女而言，阴道前壁脱垂很可能是多种因素共同作用的结果。

 

因此，如何治疗阴道前壁脱垂就成为了一大挑战，这使得外科医生不得不采用各种移植材料来降低经阴道修补术的失败率以及术后脱垂复发的发生率。数项研究表明，网片加固修补术的确可以改善短期复发率，但其长期持久性和安全性尚不清楚。显然，我们需要更加全面地评估移植物用于经阴道修补术的解剖学疗效及其改善症状的效果。

 

就目前而言，传统的阴道前壁修补术加穹窿悬吊术仍是一期修补的首选方法。可通过骶骨阴道固定术、宫骶韧带悬吊术或骶棘韧带悬吊术来完成阴道穹窿的附着。骶骨阴道固定术既可为前壁提供穹窿支撑也可提供中线支撑。包括我本人在内的许多外科医生都认为，对于患有膀胱膨出和穹窿膨出的妇女，应选用骶骨阴道固定术。

 

解剖与评估

 

了解盆底解剖以及阴道前壁的梯形解剖学特征是认识各种类型的膀胱膨出以及相应的修补术所必需的。前壁的梯形平面是由于其附着于耻骨联合腹侧和偏内侧以及坐骨棘背侧和偏外侧而形成的。前壁的两侧都悬吊于盆筋膜腱弓(ATFP)处提肛肌上的盆壁筋膜。

 

膀胱膨出的分类取决于筋膜附着于盆腔侧壁的断裂部位。侧壁附着消失则导致所谓的阴道旁缺陷或膀胱膨出移位。因此，阴道旁修补术的目标是使阴道侧壁重新附着于ATFP。

 

当耻骨宫颈筋膜顶部与宫颈或阴道穹窿分离时则出现膀胱横向膨出；阴道前穹窿消失可证实这一点(如果子宫切除术后出现了膀胱横向膨出，那么脱垂通常包括肠膨出和穹窿支撑消失，也必须进行修补)。膀胱中央或远端膨出涉及耻骨附近的支撑消失并且可能表现为尿道过度活动。

 

只要了解了阴道前壁的梯形解剖学特征，就很清楚恢复穹窿支撑的重要性。数项研究表明，膀胱膨出的类型和严重程度上的差异通常都取决于穹窿支撑的程度。例如，John O.L. DeLancey博士及其同事发现，根据患者行Valsalva动作时脱垂的MRI表现来看，前壁脱垂往往是因穹窿支撑消失所致(Am. J. Obstet. Gynecol. 2006;194:1438-43)。

 

在另一项纳入了325例妇女的队列研究中，研究者同样发现，阴道前壁脱垂与穹窿脱垂明显相关。研究者还总结道，需要手术修补的阴道前壁缺陷通常都需要同时修补阴道穹窿(Am. J. Obstet. Gynecol. 2006;195:1837-40)。

 

与阴道后壁脱垂相同，必须首先确定患者哪一部分的支撑结构出了问题。必须开展仔细的体格检查以发现缺陷及脱离部位。通过使用环钳在ATFP水平支撑前侧壁则可发现阴道旁缺陷并确定穹窿脱垂的程度。

 

在使用环钳支撑穹窿的同时，令患者用力或咳嗽。如果患者的阴道前壁仍处于原位且膀胱膨出消失，我便知道手术时需要行穹窿悬吊术。如果患者仍有一定程度的松弛，则说明需要行穹窿悬吊术加阴道前壁修补术。

 

与阴道后壁脱垂相同，我们还必须了解困扰患者的症状是什么，这些症状是否与体格检查的结果相符，以及通过手术纠正解剖结构是否能够改善这些症状。然后再通过恰当的方式告诉每一位患者脱垂手术可能对膀胱和性功能造成的影响。

 

目前普遍存在一种误解：膀胱膨出患者大多都还患有压力性尿失禁。事实上，位于膀胱底部下方的阴道中段下降反而可能降低出现压力性尿失禁的几率。相反，排尿功能障碍更为常见，因为用力和腹压增高会导致尿道扭曲或受压，从而将膀胱膨出推至能够造成出口阻塞的部位。

 

我们曾对35例患有3期或4期前壁脱垂且两次分别测量均发现排尿后残余尿量大于100 ml的患者进行了回顾性评价。结果显示，31例(89%)患者在接受了重建手术并且前壁脱垂得以纠正之后，排尿后残余尿量恢复正常(Am. J. Obstet. Gynecol. 2000;183:1361-4)。

 

奇怪的是，纠正膀胱膨出反而可能暴露出“隐匿性”压力性尿失禁。术前，如果膀胱灌注负荷试验示脱垂减轻，则可能提示该患者在脱垂修补术后有出现压力性尿失禁症状的风险。如果计划行骶骨阴道固定术，CARE (阴道固定术与减轻尿路症状)试验则建议无论术前尿动力学如何，都应在施行手术时置入Burch 阴道悬吊带。该建议是否真的适用于阴道修补术目前尚不清楚。

 

作为手术决策过程的一部分，术前应与患者讨论膀胱膨出修补术后出现尿失禁的风险、预防性抗尿失禁手术的利与弊以及将来需要手术纠正的可能性。

 

阴道前壁修补术的技巧

 

传统的阴道前壁修补术涉及“盆内筋膜”或阴道壁裂开后阴道壁纤维肌层的折叠术。采用Kelly折叠缝合来支托膀胱颈最初是由Howard Kelly于1913年提出的。

 

用Allis钳将阴道前壁牵至中线两侧。如果患者已经接受了经阴道子宫切除术，则钳夹阴道断端。如果子宫位置正常，则用Allis钳在距离宫颈阴道交界处大约1 cm的位置钳夹阴道，最初采用横切口。

 

在介于粘膜与膀胱之间的前壁中注入10 ml加压素溶液，每50 ml生理盐水含20个单位的加压素。通过注射加压素可改善止血功能并形成水分离。在距离尿道膀胱颈1~2cm的位置作正中切口。

 

采用“三点”牵拉有助于剥离肌层。然后用数个Allis钳牵开阴道。主刀医生用食指撑起阴道壁，以便确定用Metzenbaum剪进行剥离的厚度。助手则可采用扁桃体夹持钳或DeBakey钳进行对抗牵拉。剥离纤维肌层直至耻骨下支水平。然后在阴道对侧重复以上操作。

 

我本人惯用的一处改良是从阴道穹窿开始折叠而不是膀胱颈。这样我就可以避免折叠在尚未达到穹窿部位时就终止了，也可以避免留下“缝隙”或修补术中的漏洞。毕竟最重要的是修补穹窿部分。我一般都采用永久性缝线，首选2-0 Ethibond。

 

如果阴道壁正好是达到穹窿支撑所需的长度，我便采用横向褥式缝合来折叠筋膜。如果阴道壁需要缩短，则采用垂直褥式缝合。这通常会使前壁缩短2~3 cm。对于膀胱膨出严重者，可采用两层折叠。摘除多余的阴道组织并采用可吸收的细缝线通过间断或连续缝合来关闭切口。

 

当诸如宫骶韧带悬吊术或骶棘韧带悬吊术一类的穹窿修补术与阴道前壁修补术联用时(多半都是这种情况)，则应在开始阴道前壁修补术之前确定好穹窿修补术的缝合部位并暂停缝合。

 

在前壁修补结束之后，再将穹窿缝合与阴道断端连接在一起。无论采用哪种类型的经阴道悬吊术，均宜将悬吊带的一端与前壁断端相连，并将悬吊带的另一端与后壁断端相连。这样的话，缝线打结后前壁和后壁就连在了一起同时也完成了悬吊。

 

移植物的使用

 

2008年，美国妇外科医师协会(SGS)对相关文献进行了系统评价，并就阴道移植物的使用发布了临床实践指南。SGS研究小组总结道，采用不可吸收的合成移植物可能会改善阴道前壁的解剖学结果，但鉴于其带来的附加风险，仍应折衷考虑。研究小组称，虽然目前报告和开展的针对网片型新产品的随机试验越来越多，但要确定这类移植物的解剖学疗效及其改善症状的效果，仅凭这些数据还远远不够(Obstet. Gynecol. 2008;112:1131-42)。

 

与SGS所开展的评价类似，Cochrane协作网也完成了一项系统评价并总结道：在施行阴道前壁修补术时置入网片或移植物可降低膀胱膨出复发的风险，但基于现有证据，尚不足以推荐其用于阴道前壁或穹窿修补术(Cochrane Database Syst. Rev. 2010;CD004014 [doi: 10.1002/14651858.CD004014.pub4])。

 

总的来看，现已完成的少量随机试验表明，在考虑采用阴道网片或移植物治疗阴道前壁脱垂之前，医生和患者都必须权衡这样做的利与弊。

 

一项试验将202例患者随机分组，分别接受阴道前壁修补术用或不用低分子量聚丙烯网片。结果显示，基于盆腔器官脱垂定量(POP-Q)分度法，体格检查示使用了网片的患者其前壁脱垂1年复发率低于没有使用网片的患者，但两组患者的症状无显著差异。

 

该试验显示，与标准阴道前壁修补术相比，网片加固修补术后的1年治愈率(定义为POP-Q分期0或1期)显著提高(62%对93%)。但在使用了网片的患者中，压力性尿失禁的发生率更高(23%对10%)。关于症状的结局指标，如阴道膨出或患者自我感觉的排尿困难，以及1年内再次手术的发生率均无显著差异。在网片加固组中网片暴露的发生率较高，17%对0% (Obstet. Gynecol. 2007;110[pt. 2]:455-62)。

 

在另一项由一名外科医生施术的随机对照试验中，38例患者接受传统的阴道前壁修补术，另外37例则使用了Perigee经闭孔脱垂修补系统的聚丙烯网片。John N. Nguyen博士总结道，较之没有使用网片加固的阴道前壁修补术，接受了聚丙烯网片加固修补术的患者从解剖学来看的1年复发率更低(Obstet. Gynecol. 2008;111:891-8)。

 

在该试验中，两组患者的脱垂和尿失禁症状均显著改善，但两组患者的性功能症状评分均无显著变化。

 

总的来说，现有证据似乎支持采用合成网片来加固阴道前壁脱垂的修补，但因此付出的代价是并发症的发生率也随之增加，尤其是网片暴露。

 

我在临床实践中发现，大多数的阴道前壁脱垂复发病例都与穹窿下降相关。对于这类患者，我建议行腹腔镜下骶骨阴道固定术。对于单纯性阴道前壁脱垂复发且穹窿支撑良好的患者，我暂不考虑使用经阴道网片。

 

本栏目“专家课堂”(Master Class)定期出现在Elsevier旗下期刊《妇产医学新闻》(Ob.Gyn. News)中。Fenner博士是美国密歇根大学-安娜堡分校女性健康的Harold A. Furlong教授兼妇科主任。Fenner博士是全美知名的妇科泌尿学专家和讲演者。Fenner博士声明接受了位于美国明尼苏达州明尼通卡的AMS公司提供的研究经费。AMS公司是Perigee经闭孔脱垂修补系统的生产厂家。如需回复，请致信。