Historical review of prolapse repair techniques

Early surgical procedures were designed to block prolapse but did not address the anatomical cause of the condition. In the early part of the 20th century, a large influence on technique was developed under the persuasion of Howard Kelly of Johns Hopkins University. Kelly’s technique relied on plication of the perivaginal connective tissues towards the midline. A seminal observation by the much less influential George White of Savannah, Georgia, largely went unnoticed by the gynaecologic surgery community. He correctly identified the importance of the lateral fascial attachments of the connective tissues under the bladder in repair of the anterior vaginal segment. His observations would be rediscovered and more completely appreciated half a century later by Baden and Walker and Burch. Examples of popular early operations are plication colporrhaphies of the vaginal walls and colpocleisis. Plication operations simply involved folding the connective tissues of the anterior and posterior vaginal walls towards the midline adjacent to the bladder or rectum, respectively. The theory behind plication is the reduction of a bulging vaginal wall by folding weakened and attenuated endopelvic connective tissues towards the midline. Certainly, bulges can be reduced in this way; however, anatomical results typically were temporary and were obtained at a high functional cost to the patient. Unfortunately, long-term follow-up reveals several problems, including return of prolapse in up to 60% of women and a significant degree of dysparaeunia because the calibre of the vagina was narrowed during the operation. Plication operations are simple, relatively safe to carry out and are not time-consuming. Little, if any, pelvic sidewall anatomical knowledge is required on the part of the surgeon. In fact, before the availability of blood transfusions, Kelly and Dunn actually discouraged approaching the pelvic sidewall because of the fear of haemorrhage. Low-grade prolapse could be corrected fairly efficiently with plication. A growing knowledge base and population analysis indicate that only a minority of adult, and particularly parous, women, have perfect pelvic support and suspension. For this reason, repair of low-grade prolapse should not be encouraged unless the patient is particularly symptomatic in some way. Prolapse outside the introitus is much more likely than internal prolapse to be symptomatic and require surgical repair.

Colpocleisis operations create a connective-tissue barrier that either partially or completely occludes the urogenital hiatus. Incomplete colpocleisis (e.g., LeFort–Neugebauer or Labhart procedure) offers reduction of prolapse with minimal dissection and tissue manipulation, and little associated morbidity. Hysterectomy is not necessary in incomplete colpocleisis. Complete colpocleisis does require hysterectomy and, to some degree, vaginectomy, but will not restrict a woman’s subsequent activities. The various forms of colpocleisis work well in properly chosen patients, but this procedure is not acceptable to most women as it renders intercourse impossible. The patient must commit to being acoital for the remainder of her life. Colpocleisis remains a viable choice for the following women: women with high-grade prolapse, multiple previous operative failures, those who value a particular lifestyle over coital potential, elderly women or those with the presence of multiple medical co-morbidities. Success rates for colpocleisis operations generally exceed 90%. Careful informed consent is necessary for this operation.

Following plication colporrhaphies and colpocleisis, the next major conceptual advance was the recognition that careful surgical dissection could identify the supportive and suspensory elements of the endopelvic fascia. When these tissues were carefully inspected surgically, surgeons did not find weakened and attenuated connective tissue. Rather, they discovered discrete breaks in the pelvic fasciae and ligaments surrounding the vagina and cervix, respectively. These damaged tissues could routinely be identified and surgically manipulated in a way that approximated restoration of normal anatomy more effectively than plication in women with POP. This finding led to a major revision of surgical techniques in the 1980s in the form of site-specific repairs. The fascial breaks were not found in the distal vaginal midline where the corrective efforts of plication colporrhaphy were centred. Instead, they were identified in the deep pelvis adjacent to the interspinous diameter in the form of apical transverse defects of the anterior and posterior vaginal wall fasciae and as paravaginal defects located laterally at the fusion of the deep endopelvic connective tissue and the parietal fasciae of the pelvic muscles along the pelvic sidewalls. As a result, anterior and posterior plication colporrhaphy was no longer considered an anatomically sufficient operation by many experts, and POP reparative surgery could no longer be carried out in the relatively safe and familiar distal midline of the vagina.

Because of conceptual changes in the way POP was believed to develop, pelvic surgeons found it necessary to learn to operate in deep pelvic and sidewall anatomy that was previously unfamiliar to many gynaecological and other pelvic surgeons. Deep pelvic sidewall anatomy was familiar to gynaecological oncologists via the abdominal route, but many prolapse repairs necessitated negotiation of the structures, such as the uterosacral and sacrospinous ligaments, by the vaginal route, while being constantly cognizant of the location of vulnerable structures such as the ureter, pelvic nerves and major vascular structures. Detailed three-dimensional knowledge of the musculoskeletal, neurovascular and connective tissue anatomy became critical to the success of these operations. The location and basic pattern of fascial defects correlated well with the forces exerted on the pelvis during the progression through the cardinal movements of labour during childbirth. Site-specific surgery using native tissue remains a viable option today; however, as with plication, some problems exist. Anatomical and functional failures, even in the best hands, continued to be encountered. Repair of prolapse is inherently flawed because of bipedal human female pelvic anatomy that places the urogenital hiatus in a continuously dependent location. In addition, POP repair is different from any other hernia repair in the body because, in most of them, the opening that allows the prolapse to develop (the urogenital hiatus) is not narrowed or closed during the operation. This concept is in direct contrast to the way most herniorrhaphies are conducted elsewhere in the body. The sole exception to this difference in hernia repair technique is the set of colpocleisis operations mentioned previously. In those operations, the urogenital hiatus is intentionally effectively blocked by connective tissue. As a result, success rates with those operations are consistently higher than with reparative vaginal surgery of any type. Anatomically and functionally restorative POP surgery is conducted within the largest potential opening in the body. The native tissues used in the repair have already been exposed to the high-pressure avulsions of childbirth, and therefore have been forced to fail their natural function in the body before starting repair.

In the 1980s, ventral herniologists began to use bolsters to augment hernia repairs of the abdominal wall with better success than had been obtained with native tissue repairs. These bolsters were of various types as classified by Amid, about a decade after they started to be used in ventral hernia surgery. In an effort to improve anatomical and functional outcomes, various products were developed to strengthen POP and urinary incontinence surgeries. Today, development of new polypropylene mesh, cadaveric allograft and porcine and bovine xenograft products continues at a dizzying rate. These products may be introduced into the body vaginally, abdominally, laparoscopically or robotically. Generally, bolsters used in the abdominal wall are thicker and more substantial than the ones used in the vagina. Significant differences exist between the abdominal wall and the vagina. Most notably, the abdominal wall is perceptibly thicker with several anatomical layers between the peritoneum and the skin, permitting the use of relatively heavier materials in repair without risking exposure to the high natural bacterial colonisation of the skin. In the vagina, only a relatively thin layer of endopelvic connective tissue separates the vaginal epithelium and the immediately adjacent bladder or rectum. In addition, the vagina normally has one of the highest bacterial colony counts in the body. Implantation of permanent or non-remodelling materials in such an environment, even for theoretically justifiable reasons, can and does have potential negative consequences on the patient. This potential for complications has come to the attention of the United States Food and Drug administration (FDA). After reports of over 1000 mesh and bolster complications, the FDA, in 2008, issued a warning urging caution and informed consent when strengthening materials are used in the treatment of POP. Various sizes, shapes and methods of introduction of these bolsters have been developed. Unfortunately, this process of innovation has been driven by industry for the most part. In such a fast-paced competitive business environment, long-term follow-up has not been abundant or frequent, despite the widespread clinical use of mesh and bolsters in POP surgery. The innovation of products and materials has outpaced the medical community’s ability to determine functional, anatomical and safety outcomes.

Polypropylene mesh is now the favoured thermoplastic polymer for implantation in POP surgery. Polyester and extruded polytetrafluoroethylene materials are no longer in common use as bolsters in the pelvis. Significant advances in the thickness and weave of the material are the latest changes to be made. Recently, interest has also been generated in xenographic materials that are not cross-linked and have the capacity to remodel into native connective tissue. These materials have the obvious advantage of not carrying with them the set of complications known to be associated with polypropylene mesh repairs because these materials disappear in about 6 months and are replaced by native connective tissue. Long-term outcomes remain to be seen with all of these techniques.

Much progress seems to have been made in understanding the cause, progression, symptomatology and treatment of POP. This field has changed as rapidly as any field in medicine and surgery over the last half century. Each new change or revision in surgical approach has been intended to overcome a shortcoming of a previous approach.

Best practices in prolapse repair

Several factors conspire to create difficulties in making a declaration that a particular approach in POP surgery is superior. As mentioned earlier, the rapid rate of change in techniques, concepts and available materials prevents the development of truly evidence-based long-term data. With POP surgery today, as soon as a surgical technique or bolster kit is available for widespread use, another technique or product is generated. For various reasons, each new approach seems to gain a following of practitioners despite the absence of scientific analysis of outcomes. One reason for this eagerness to change is the knowledge that traditional techniques are inadequate long-term treatments for the problem of prolapse. Although good and defensible theoretical reasons may be in place for a change, this approach is less than ideal for a scientific analysis of outcomes.

Surgery for POP is not a simple undertaking. Complex deep pelvic anatomy abounds in the area of the interspinous diameter where anterior, posterior and apical repairs are centred. The biodynamics and function of the various systems are as subtle as any region of the human body. A myriad of potential complications can be associated with these operations. Debates continue regarding a proper definition for POP, and, perhaps more importantly, how to measure treatment success. In assessing treatment success, both functional outcomes of the three involved pelvic organ systems, and structural outcomes, are important. These various outcomes are difficult to measure, even with the use of validated outcome measurement tools and pelvic floor anatomy tools such as the Baden Walker Pelvic Support Profile or the more recently created pelvic organ prolapse-quantitative (POP-Q) system. The most common structural definition for successful POP surgery is the postoperative absence of external prolapse, not normal internal vaginal anatomy of 10 cm or more of vaginal depth. Although this concept of success may seem to be a compromise, it also alludes to the difficulty in achieving an anatomically normal outcome. Functional success related to sexual, urinary and bowel symptoms are also considered important to the patient’s outcome both clinically and in scientific studies.

In POP surgery, so many variations in technique exist that all cannot be perfectly controlled for scientific analysis. Ideally, in a given surgical study of outcome, each operation would be carried out in the same way and confounding variables rigidly controlled. Practically speaking, this ideal situation will never be achieved for POP surgical analysis. Inter-operator differences in skill level and in the nuances of technique will always make true scientific analysis subjective to some degree. Even with these inherent limitations, some things seem clear. Older techniques of plication cause known problems and overall have poor outcomes for quality of life and longevity of repair. Ideally, emphasis should be placed on anatomically restorative procedures (e.g., site-specific repairs rather than anatomically distorting operations). Plication colporrhaphy is based on a century-old theory of attenuation of connective tissue, unsupported by clinical observation, rather than more current knowledge gained from biomechanical analysis and intra-operative observation regarding discreet, predictable and repairable defects in the deep endopelvic connective tissue. The relative ease of a distal midline plication should not seduce the surgeon away from more challenging repairs that are imminently more rewarding from an anatomical and functional standpoint. If the primary goal of surgery is the restoration of normal anatomical relationships, then the potential for restoration of normal function is maximised.

Repair of POP presents the pelvic surgeon with unique challenges. The urogenital hiatus is large enough to accommodate the passage of a term infant. With this unavoidable fact taken as a given, reparative vaginal surgeons are called upon to repair anatomically and functionally complex hernias without the benefit of closing or narrowing the opening that allows the prolapse to develop. Furthermore, this large natural opening in the female pelvis has a dependent location in the abdomen, is exposed to continuous gravitational and exertional forces that project pressure on childbirth-damaged and avulsed vaginal fascial septa, and has a muscular pelvic floor that may be deficient or dysfunctional. Even after repair, the urogenital hiatus remains subject to gravitational forces, and childbirth damage remains present regardless of the nature of the repair. This combination of factors most likely accounts for the less-than-ideal historical success rate that has been reported in POP surgery. Consequently, bolsters of various types have been developed that represent strengthening materials for POP repairs. These materials are probably useful in these repairs. The exact type, shape, size, method, depth of introduction and precise technique of concomitant repair are currently unknown. As indicated earlier, the rapidity of conceptual change in pelvic reconstructive surgery precludes the collection of definitive data regarding optimal surgical outcome.

Some data suggest that abdominal sacral colpopexy should be considered to be the ‘gold standard’ of POP repair because those procedures apparently have the best anatomical outcomes at this time. Undoubtedly, this technique, which emphasises the creation of a totally new apical suspension mechanism using implanted materials, can be successful in many patients. Counterbalancing this success is the inherently invasive open abdominal or endoscopic approach necessary to achieve the result. Access through the abdomen, whether it is open, laparoscopic or robotic, is more invasive and places more surgical burden onto the patient than the natural orifice approach through the vagina. Although outcomes must be considered and respected, the quest must continue for excellent results that minimally affect the patient. In the case of POP, the vaginal approach would be an ideal primary approach if results equivalent or superior to any other approach can be demonstrated. Techniques of extraperitoneal vaginal uterosacral or sacrospinous colpopexy, which accomplish the same suspensory goals as abdominal sacral colpopexy, have been developed and carry great promise.

Restoration of apical suspension is a necessary primary goal for acceptable long-term outcomes in POP surgery. Biomechanical analysis has defined the importance of apical suspension, mid-vaginal lateral attachment and distal fusion with sturdy structures that are located at or near the vaginal opening. Equally as important is an analysis of how the forces of childbirth specifically affect the various components of the deep endopelvic connective tissue and where the damage occurs in the complex, interconnected and continuous connective tissue anatomy within the pelvis, and particularly within the interspinous diameter. Particularly important in this type of analysis is the recognition that the most important steps mechanically in a prolapse operation are the recognition and correction of apical transverse defects in the posterior and anterior segments. This concept of transverse-defect repair both complicates and simplifies POP surgery. The repair is more challenging anatomically because deep avascular space dissection is necessary for exposure and completion of the operation; however, the simplicity of the concept explains the exact task that needs to be completed and greatly assists in repair. Once the biomechanics of childbirth injury that creates transverse defects and causes displacement away from the interspinous diameter is recognised, plication colporrhaphies are no longer satisfactory operations. Any operation that does not account for or compensate for these apical transverse-defect concepts is more likely to fail than operations that do take these concepts into consideration.

The profuse proliferation of bolsters available to assist with apical suspension in POP repair is obvious to reparative pelvic surgeons. Insufficient data preclude an objective recommendation for the use of particular products. No recommendation based on evidence can be made regarding size, shape, method of introduction or type of material used to strengthen POP surgery. Procedurally, these materials should be used to augment biomechanically sound repairs, not used as a shortcut in technique or a compensation for a surgeon’s inadequate anatomical knowledge and deep pelvic dissection skills. If pelvic surgeons have learned one thing over the last 130 years, it is that the pelvis is anatomically and functionally complex. Operations that encourage the substantiation of bolsters for meticulous surgical technique are not acceptable and are likely to fail. Bolsters, in my opinion, should be used to strengthen technically sound repairs, not used as a shortcut in the expectation that a kit can miraculously compensate for anatomically and biomechanically sound surgical technique.

Deep pelvic dissection, distorted anatomy and the normal anatomical proximity of the ureters are a cause for concern among POP surgeons. Typical reports that use universal cystourethroscopy in groups of women undergoing POP surgery identify ureteral occlusion rates in prolapse procedures to be in the range of 5%. For that reason, intra-operative cystourethroscopy to establish the presence of patent ureters and an intact bladder mucosa should be considered standard of care. The distal ureter is only millimetres away from the lateral anterior pelvic attachments associated with paravaginal paravesical defects. Prolapse distorts normal anatomy and can displace the ureter as the degree of vaginal descent increases, especially in advanced utreovaginal prolapse. Previous surgeries, particularly those that involve plication, can affect the anatomy of tissues in the area of the normal location of the ureters in the pelvis. Kinking or total occlusion of the ureters is possible in any type of POP repair. In addition, if any question exists about the state of the ureters or bladder wall, cystourethroscopy should be conducted before starting surgery. The importance of a pre-procedure cystourethroscopy is that the initial state of integrity of the bladder and ureters can be determined. Waiting until after the current procedure can obviously confuse clinical interpretation, if an apparently non-functional ureter is not determined before surgery begins. The same concept applies to deep-digital-rectal exam, anoscopy or sigmoidoscopy before or during surgery to assure the integrity of the rectum. The rectum is in proximity to the sigmoid colon and rectum near the sacrospinous ligaments, particularly the left one. Women with mesh complications, recurrent prolapse and distorted anatomy are can qualify for preoperative cystourethroscopy, anorectal investigation or both.