In this video, I will discuss the techniques to enter an interstitial sac in patients with symptomatic prolapse who are post-hysterectomy. There are three methods that can be utilized and include entering an interstitial sac through the vaginal apex, through the posterior vaginal wall, or the anterior vaginal wall. This first example is a post-hysterectomy patient who has an apical prolapse, as you can see here, plus some prolapse of the uppermost portion of the posterior vaginal wall. This particular patient has actually had vaginal mesh placed in the anterior vaginal wall, and this compartment is well-supported. One can see nicely the extent of her apical prolapse and posterior compartment prolapse. We initiate a midline incision at the most dominant portion of the prolapse through the vaginal epithelium. Then Alice clamps are placed on the epithelium, and with dissection in the cephalad direction, the interstitial sac is easily entered. One can see here that the vaginal epithelium is very thin, and now the peritoneum will be dissected off the epithelium. A significant portion of the interstitial sac, as well as redundant vaginal wall, will be excised in preparation for an intraperitoneal suspension, which in this situation will be a high bilateral uterosacral suspension. One can see here the bowel is packed out of the way, and we have good exposure to pass suture through the uppermost portion of the uterosacral ligaments. The next example of a posthysterectomy prolapse is seen here. This is a patient who has had a previous anterior compartment suspension, resulting in a shortened anterior vaginal wall, and a large apical prolapse that includes a portion of the posterior vaginal wall. We initiate the dissection at the most prominent portion of the prolapse. One can see that we are carefully mobilizing the vaginal epithelium off the underlying interocele sac. We have identified a good area to enter the sac, and here we have entered the peritoneal cavity. In doing so, a very redundant sigmoid colon is identified, thus the patient is diagnosed with a large sigmoidoscele. Entering the peritoneal cavity has allowed us to fully assess this area. We are excising excess posterior vaginal wall and peritoneum. In this situation, we will close the peritoneal cavity and proceed with an extra peritoneal suspension of the vaginal vault, specifically a right sacrospinous ligament suspension. As in our opinion, this is not a good candidate for an intraperitoneal suspension due to a difficult exposure of the uterosacral ligaments. Now we will describe the techniques utilized to enter an interocele sac through the posterior vaginal wall. Two examples will be utilized to demonstrate this technique. The first example shows a patient in which the posterior vaginal wall has already been opened. This example is used to demonstrate the close proximity of the anterior wall of the rectum to the posterior wall of the interocele sac. Sharp dissection with the finger and the rectum is utilized to create a nice plane between the two structures. Here one can see that the interocele sac has been dissected off the anterior wall of the rectum. Utilizing sharp dissection with the finger and the rectum, this can be done in a safe fashion as there is usually an avascular plane separating the two structures. Once the interocele sac has been completely mobilized off the anterior wall of the rectum as well as off the vaginal apex, it can easily be entered sharply. In this patient, one can see there is a large posterior interocele. Excessive tissue is being excised all the way to the neck of the interocele. We will then proceed with an intraperitoneal repair with either a purse string closure of the interocele sac or a formal intraperitoneal vault suspension. In this example, a patient with a predominant anterior vaginal wall prolapse and behind the cystocele, we feel strongly that there is an interocele sac. The goal will be to dissect the base of the bladder off of the apex of the vagina with the hope of entering the interocele sac that will facilitate the ability to suspend the vaginal apex. A midline anterior vaginal wall incision is made. We feel strongly that sharp dissection should be used in conjunction with traction and counter traction to find an ideal plane to separate the cystocele from the full thickness of the vaginal wall. It's important to completely mobilize the cystocele prior to dissecting posteriorly to identify the interocele sac. Sharp dissection, traction, and counter traction are used to fully mobilize the cystocele. In the region of the vaginal apex, significant scarification can be noted and this underscores the importance of using sharp dissection. We are now dissecting the base of the bladder off of the apex of the vagina. The goal is to enter a preperitoneal space that will lead us to the interocele sac. Significant scarification is encountered and at this time a finger is placed in the rectum and will be used to delineate a clear plane between the anterior wall of the rectum and the base of the bladder that will hopefully lead to an interocele sac. A finger has been placed in the rectum and a retractor is used to mobilize the cystocele out of the field. One can now see the reflection of the anterior peritoneum. Sharp dissection just on top of the finger that is in the rectum allows entrance into the peritoneal cavity. We feel that this is a very important portion of the prolapse repair as it allows us to proceed with an interperitoneal suspension. While an interocele can develop in any of the three compartments of the vaginal vault, the two most common locations are an interocele of the posterior vaginal wall or an interocele at the vaginal apex. Isolation and entrance into the interocele sac in a post-hysterectomy patient with pelvic organ prolapse is important because it provides access to the peritoneal cavity, providing the surgeon the ability to perform an interperitoneal vaginal vault suspension.

interstitial sac

post-hysterectomy patients

symptomatic prolapse

intraperitoneal suspensions

intraperitoneal vaginal vault suspensions