Materials and Methods

This is a prospective study that describes the effectiveness of the Prolift system in pelvic organ prolapse repair with the use of both MRI and POP-Q examination as outcome measures. Institutional review board approval was obtained from the Indiana University-Purdue University Indianapolis/Clarian Institutional Review Board. Patients were recruited from a tertiary referral center for pelvic floor disorders. Inclusion criteria were the presence of symptomatic International Continence Society stage 2 prolapse or greater of any compartment, an agreement to the use of vaginal estrogen pre- and postoperatively, a minimum preoperative vaginal length of 5 cm, the ability to give informed consent, and healthy surgical candidates who had already consented to undergo the Prolift repair. Exclusion criteria were the presence of medical comorbidities that made patients unacceptable surgical candidates, unwillingness or inability to undergo MRI or pelvic examination, pregnancy, and a history of prolapse surgery with synthetic mesh.

Patients who met inclusion criteria were informed of the study during an office visit. For those who wished to participate, informed consent was obtained. The study was funded by Women’s Health and Urology (Ethicon Inc.) to cover the cost of the MRI and patient expense. All procedures were performed through a vaginal route to reconstruct normal vaginal support with the use of the Prolift system. All procedures were performed with the technique outlined by Ethicon Women’s Health and Urology with the use of regional or general anesthesia. In 5 patients, the mesh was cut into 2 pieces. Reasons for this included the presence of a uterus in 3 women and the need for the mesh to be trimmed to fit the vaginal length in 2 women. Antibiotics were administered preoperatively and for 24 hours postoperatively. Patients were scheduled for their postoperative visit at 6 weeks at which time they underwent a POP-Q examination and were questioned about symptoms of prolapse, pelvic pain, and voiding and defecatory dysfunction. Additional studies included a standing stress test, uroflow, and postvoid residual. Postoperative MRIs were scheduled to be performed between 6 and 12 weeks after surgery.

All MRIs were performed with the patient in the supine position with a 1.5-T superconductive unit and a circularly polarized (quadrature) body coil. Patients were asked to empty their bladder on arrival. Before the examination, patients were instructed about the voluntary maneuvers, which consisted of progressive straining and a contraction of the pelvic floor muscles (squeeze) followed by relaxation. The vagina and rectum were then opacified with 20 mL and 200 mL, respectively, of sonographic transmission gel (Aquasonic 100; Parker Laboratories, Fairfield, NJ) that was introduced through a 26-F catheter. Patients were then asked to perform the rest-squeeze-relax- strain maneuver, as previously described, as part of the prolapse staging protocol of Kelvin et al. During this process, a dynamic series of images were obtained in the mid sagittal plane with true fast imaging in a steady-state free precision sequence. The evacuation and postevacuation sequences that were performed at maximum strain were evaluated for the presence of pelvic organ prolapse. Pre- and postoperative MRIs were compared according to the HMO classification system as described by Comiter et al. The HMO system measures the width of the genital hiatus (H-line), levator muscle descent (M-line), and organ prolapse (O).

Comparisons between pre- and postoperative MRI and POP-Q measurements were performed with paired Student t tests. To eliminate expectation bias, the MRIs for prolapse were read independently by 2 blinded observers, 1 clinician and 1 radiologist. If disagreements occurred, joint reading of the study was done, and a consensus was reached. The correlations between changes in POP-Q and MRI were assessed by calculation of the Pearson correlation coefficients. The MRIs were read for identification of mesh by a second radiologist who was blinded to the patient procedure. An attempt to visualize and describe MRI mesh characteristics in each compartment was made. Tissue reaction around the mesh that could arise (for example, collagen deposition and inflammation) was defined as an increase in signal on high-resolution T2 weighted sagittal images.