Magnetic Resonance-Visible Polypropylene Mesh for Pelvic Organ Prolapse Repair

Post-operative outcomes associated with anterior mesh location after laparoscopic sacrocolpopexy

OBJECTIVE

To investigate the relationship between the anatomical position of the anterior arm of the mesh, measured by ultrasound through the bladder neck-mesh distance technique and the surgical outcomes after laparoscopic sacrocolpopexy (SCP) for apical prolapse.

STUDY DESIGN

It was a retrospective analysis of prospectively collected data in a tertiary care hospital. Between January 2019 and September 2019, 63 women who underwent laparoscopic SCP due to apical prolapse were included. Bladder neck-mesh distance was measured immediately after surgery. The pelvic floor was evaluated using the Pelvic Organ Prolapse Quantification (POP-Q) System before, 1 month, and 2.7 years (mid-term) after the surgery. Post-operative stress urinary incontinence (SUI) and Patient Global Impression of Improvement (PGI-I) scores were also assessed. The correlation between bladder neck-mesh distance and the post-operative outcomes was investigated using the Spearman rank correlation coefficient.

RESULTS

At mid-term follow-up visit, bladder neck-mesh distance was inversely correlated with the correction of apical prolapse and post-operative SUI. No correlation was detected with the anterior compartment prolapse correction. PGI-I scores were high in all patients at mid-term follow-up, irrespective of bladder neck-mesh distance values.

CONCLUSION

The shorter the bladder neck-mesh distance, the better the outcome for apical compartment repair. Bladder neck-mesh distance had no correlation with the anterior anatomical correction. Shorter bladder neck-mesh distance values were positively correlated to better PGI-I scores and a higher risk of SUI.

Chemical Modifications of Porous Shape Memory Polymers for Enhanced X-ray and MRI Visibility

The goal of this work was to develop a shape memory polymer (SMP) foam with visibility under both X-ray and magnetic resonance imaging (MRI) modalities. A porous polymeric material with these properties is desirable in medical device development for applications requiring thermoresponsive tissue scaffolds with clinical imaging capabilities. Dual modality visibility was achieved by chemically incorporating monomers with X-ray visible iodine-motifs and MRI visible monomers with gadolinium content. Physical and thermomechanical characterization showed the effect of increased gadopentetic acid (GPA) on shape memory behavior. Multiple compositions showed brightening effects in pilot, T1-weighted MR imaging. There was a correlation between the polymeric density and X-ray visibility on expanded and compressed SMP foams. Additionally, extractions and indirect cytocompatibility studies were performed to address toxicity concerns of gadolinium-based contrast agents (GBCAs). This material platform has the potential to be used in a variety of medical devices.

The Use of Imaging for Synthetic Midurethral Slings

Ultrasound and magnetic resonance imaging can be used to image midurethral slings, which have may have complications such as pain. There is considerable misunderstanding regarding the utility of the different modalities. This article aims to review the current literature to identify the benefits and limitations of each imaging modality and identify the place that each should have for patients with midurethral sling complications. A literature search was performed, and all relevant articles were identified and reviewed. Different imaging modalities are complementary, but more research is required in this area.

MR scan evaluation of pelvic organ prolapse mesh complications and agreement with intra-operative findings

Introduction

An increasing number of women are presenting with symptoms after the placement of mesh implants for prolapse which may be attributable to a mesh implant complication. MRI imaging can be used to evaluate abdominally placed mesh but there is no published research evaluating the use of MRI in this group of women. The objective of our study was to report our experience as a tertiary centre in evaluating abdominal mesh with MR imaging and the agreement of MR reports with surgical findings.

Study design

A retrospective observational cohort study (Canadian Task Force classification II-2) of all women referred to our tertiary unit who underwent an MR scan for investigation of symptoms of mesh complication following an abdominally placed mesh implant between June 2006 and September 2018 was performed. The reports of MR images were compared with the findings at surgery.

Results

MR scan was performed in 87 with suspected mesh complications. MR scan detected mesh failure in 42.1% of women (37/87), infection in 12.6% (11/87), compression in 2.3% (2/87), exposure in 12.6% (11/88), bowel extrusion in 2.3% (2/87) and inflammation in 11.5% (10/87). Agreement between MR scan report and surgical diagnosis was almost perfect for mesh failure, infection and compression, whilst agreement was only moderate for mesh erosion and signs of inflammation (failure κ = 0.97, infection κ = 0.94, compression κ = 1.0, exposure κ = 0.58 and inflammation κ = 0.24).

Conclusion

These data provide information on the role of MR imaging in the investigation of women presenting with suspected intra-abdominal POP mesh complications including recurrence.

3D reconstruction of MR-visible Fe3 O4 -mesh implants: Pelvic mesh measurement techniques and preliminary findings

AIMS

To develop MR-based measurement technique to evaluate the postoperative dimension and location of implanted magnetic resonance (MR)-visible meshes.

METHODS

This technique development study reports findings of six patients (A-F) with cystoceles treated with anterior vaginal MR-visible Fe₃ O₄ -polypropylene implants. Implanted meshes were reconstructed from 3 months and/or 1 year postsurgical MR-images using 3D Slicer®. Measurements including mesh length, distance to the ischial spines, pudendal, and obturator neurovascular bundles and urethra were obtained using software Rhino® and a custom Matlab® program. The range of implanted mesh length and their placements were reported and compared with mesh design and implantation recommendations. With the anterior/posterior-mesh-segment-ratio mesh shrinkage localization was evaluated.

RESULTS

Examinations were possible for patients A-D 3 months and for A, C, E, and F 1 year postsurgical. The mesh was at least 40% shorter in all patients 3 months and/or 1 year postoperatively. A, B showed shrinkage in the anterior segment, D, E in the posterior segment (Patients C, F not applicable due to intraoperative mesh trimming). Patient E presented pain in the area of mesh shrinkage. In Patient C posterior mesh fixations were placed in the iliococcygeal muscle rather than sacrospinous ligaments. Arm placement less than 20 mm from the pudendal neurovascular bundles was seen in all cases. The portion of the urethra having mesh underneath it ranged from 19% to 55%.

CONCLUSIONS

MRI-based measurement techniques have been developed to quantify implanted mesh location and dimension. Mesh placement variations possibly correlating with postoperative complications can be illustrated.

MRI visible Fe3O4 polypropylene mesh: 3D reconstruction of spatial relation to bony pelvis and neurovascular structures

INTRODUCTION AND HYPOTHESIS

To demonstrate mesh magnetic resonance imaging (MRI) visibility in living women, the feasibility of reconstructing the full mesh course in 3D, and to document its spatial relationship to pelvic anatomical structures.

METHODS

This is a proof of concept study of three patients from a prospective multi-center trial evaluating women with anterior vaginal mesh repair using a MRI-visible Fe₃O₄ polypropylene implant for pelvic floor reconstruction. High-resolution sagittal T2-weighted (T2w) sequences, transverse T1-weighted (T1w) FLASH 2D, and transverse T1w FLASH 3D sequences were performed to evaluate Fe₃O₄ polypropylene mesh MRI visibility and overall post-surgical pelvic anatomy 3 months after reconstructive surgery. Full mesh course in addition to important pelvic structures were reconstructed using the 3D Slicer® software program based on T1w and T2w MRI.

RESULTS

Three women with POP-Q grade III cystoceles were successfully treated with a partially absorbable MRI-visible anterior vaginal mesh with six fixation arms and showed no recurrent cystocele at the 3-month follow-up examination. The course of mesh in the pelvis was visible on MRI in all three women. The mesh body and arms could be reconstructed allowing visualization of the full course of the mesh in relationship to important pelvic structures such as the obturator or pudendal vessel nerve bundles in 3D.

CONCLUSIONS

The use of MRI-visible Fe₃O₄ polypropylene meshes in combination with post-surgical 3D reconstruction of the mesh and adjacent structures is feasible suggesting that it might be a useful tool for evaluating mesh complications more precisely and a valuable interactive feedback tool for surgeons and mesh design engineers.