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Surgeons Respond to Pelvic Reconstruction Column : The Master Class


 

After reading Dr. Liu's article on laparoscopic pelvic reconstructive surgery and Dr. Grody's response, I found myself perplexed. How is it that two experienced and respected surgeons can underappreciate each other's perspective on pelvic reconstructive surgery?

For the most part, I agree with most of what each has stated but disagree on the finer points. I must confess that being predominately a laparoscopic or minimally invasive surgeon, I too did not completely comprehend the complexity and functional anatomy of the PB and membrane as an important element in pelvic floor support until more recently.

Thanks to cadaver sections and MRI studies reported by John O.L. Delancey, M.D., at the joint annual meeting of the American Urogynecologic Society and the Society of Gynecologic Surgeons in 2004, we realize that the perineal membrane is a complex 3-D structure composed of a dorsal and ventral portion rather than a trilaminar sheet as previously thought. His description of the anatomical relationship to the compressor urethra, urethra vaginal sphincter, arcus tendineus, pubic bone, and levator muscles underscores the importance of this structure in pelvic support.

We now have level 1 evidence of the laparoscope's benefit in sacral colpopexies compared with an open procedure, as well as its inferiority in treating stress urinary incontinence when comparing a laparoscopic Burch with a transvaginal tape procedure. But the laparoscope is a tool that requires proper training to master. Thanks to the pioneering efforts of Dr. Liu and Dr. Miklos, the development of training centers, and the support of organizations like the American Association of Gynecologic Laparoscopists, it is no longer the gifted few who use this valuable instrument.

The recent articles by Dr. C.Y. Liu in OB.GYN.NEWS on laparoscopic pelvic reconstructive surgery, Parts 1 and 2, are a must-read for any gynecologic surgeon performing reconstructive vaginal surgery. Although the article presents Dr. Liu's laparoscopic approach to problems of vaginal suspension and support, the anatomy presented and the surgical steps discussed are clearly applicable to the repair of any vaginal prolapse via any surgical approach, including vaginal and abdominal.

The anatomy of genital prolapse is up to date, well written, and clearly explained. Part 1 contains many pearls of insight from a master of this anatomy, and it summarizes our current concepts of vaginal suspension and support. The section on clinical assessment of prolapse is practical and very helpful.

The surgical techniques presented are anatomical and readily applicable. Dr. Liu explains how to safely dissect out and investigate the suspensory anatomy to clearly define the anatomical defects that caused the vaginal prolapse. Not only does Dr. Liu address and repair the specific breaks in the continuity of the visceral connective tissue suspensory network, but he presents an excellent dissection technique for safeguarding the ureters.

One point that should have been emphasized is the requirement for cystoscopic confirmation of bilateral ureteral functioning at the end of the case.

The article explains that one of the three supporting layers of the female pelvic organs is “the perineal membrane/external anal sphincter.” What is not said is that the anal sphincter is an important component of the posterior part of the PB.

The lower third of the vagina and the anal canal/anal sphincter are fused with the PB. The PB is shaped roughly like a pyramid, with the base between the vaginal introitus and the anal sphincter. The apex is found at the junction of the lower third and the middle third of the vagina, and at the rectoanal junction. At the apex of the perineal body, the vagina slopes to a more horizontal orientation in the standing patient, whereas the anal canal forms a right angle with the lower rectum.

Portions of the pubococcygeus and puborectalis muscles insert into the apex of the PB. The rectovaginal fascia also inserts into the apex of the PB and helps in its proper anatomical orientation. The intact PB positions itself and the anus just above the level of the ischial tuberosities. The fusion of the anus and anal canal with the PB is important for their anatomical positioning and physiologic functioning in fecal continence. The fusion of the lower third of the vagina with the PB is important for its anatomical positioning and physiologic functioning in pelvic organ support. The PB assists in closing off the genital hiatus at times of increased intrapelvic pressures, supporting the pelvic organs. Another support mechanism is the flap-valve action of the levator plate.

Many women with vaginal prolapse demonstrate abnormal descent of the perineum. Dr. Liu states, “The active support of the pelvic floor comes from the levator ani muscles (the iliococcygeus and pubococcygeus muscles). These muscles close off the pelvic floor so the pelvic organs can rest upon them without tension.” This statement is true.

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