Computed-tomography image segmentation and 3D-reconstruction of the female pelvis for the preoperative planning of sacrocolpopexy: preliminary data

Simulation of vaginal uterosacral ligament suspension damage, mimicking a mesh-augmented apical prolapse repair

Synthetic implants were used for repair of anterior compartment prolapses, which can be caused by direct trauma resulting in damaged pelvic structures. The mechanical properties of these implants may cause complications, namely erosion of the mesh through the vagina. In this study, we evaluated, by modeling, the behavior of implants, during Valsalva maneuver, used to replace damaged uterosacral ligaments (USLs), mimicking a sacrocolpopexy repair. For this purpose, two synthetic implants (A®, for prolapse repair and B®, for Hernia repair) were uniaxially tested, and the mechanical properties obtained were incorporated in the computational models of the implants. The computational model for the implant was incorporated into the model of the female pelvic cavity, in order to mimic the USLs after its total rupture and with 90% and 50% impairment. The total rupture and impairments of the USLs, caused a variation of the supero-inferior displacement and displacement magnitude of the vagina, with higher values for the total rupture. With total rupture of the USLs, when compared to healthy USLs, supero-inferior displacement and displacement magnitude of the vagina increased by 4.98 mm (7.69 mm vs 12.67 mm) and 6.62 mm (9.38 mm vs 16.00 mm), respectively. After implantation (A® and B®) a reduction of the supero-inferior displacements of the anterior vaginal wall occurred, to values found in the case of the model without any impairment or rupture of the ligaments. The simulation was able to mimic the biomechanical response of the USLs, in response to different implants stiffnesses, which can be used in the development of novel meshes.

Measures for Safe Laparoscopic Sacrocolpopexy: Preoperative Contrast-Enhanced Computed Tomography and Perioperative Ultrasonography

Laparoscopic sacrocolpopexy is one of the most difficult laparoscopic surgical techniques. In this study, we report on our efforts to safely perform this procedure, which consists of suturing a piece of mesh onto the anterior longitudinal ligament using a nonabsorbent suture during mesh fixation onto the prepromontorium layer, which can lead to massive bleeding if a mistake is made, by performing preoperative and intraoperative image evaluation. Preoperative contrast-enhanced computed tomography was performed. Images in DICOM format were acquired, and three-dimensional vessel reconstruction was performed. After performing a peritoneal incision in the presacral area, ultrasonography was performed using a probe inserted through a 12-mm trocar into the abdominal cavity to re-confirm the absence of vessels near the planned suturing area. After ultrasonography, an Ethibond^® suture was inserted through the anterior longitudinal ligament. In our hospital, 126 patients underwent the procedure, and none had a serious hemorrhage or required blood transfusion, indicating the safety of this modified procedure without separation of a wide presacral area. We believe that these techniques can be performed safely with minimal incision. However, we did not examine the efficacy of these techniques in this paper. Further studies are needed to determine whether this approach is suitable.

Exploration of the safe suture area of the presacral space in sacrocolpopexy by 3-dimensional (3D) models reconstructed from CT

INTRODUCTION AND HYPOTHESIS

The objective of this study, a digital in vivo anatomical study based on patient-specific three-dimensional (3D) models reconstructed from computed tomography (CT) scans, was to clarify the anatomy of the presacral space and suggest a safe area for complication-free graft or mesh fixation.

METHODS

We retrospectively studied 182 CT angiography (CTA) datasets from Han Chinese women examined for gynecological diseases from January 2018-June 2020; we used Mimics 21.0 to create 176 3D models of the female presacral space. The distances of pelvic structures from the presacral vessels and ureters were standardized and measured in 3D mode.

RESULTS

The distances from the median sacral artery (MSA) to the bilateral great vessels and bilateral ureters at the sacral promontory (SP) level were similar to the respective distances from the midpoint of the SP (MSP) to those four structures (p > 0.05). At the level of the first transverse line, when the MSA was right of the midline, the MSA was 20.74 ± 3.86 mm from the medial edge of the left first anterior sacral foramen. When the MSA was left of the midline, its average distance from the medial edge of the right first anterior sacral foramen was 20.89 ± 4.92 mm. The SP was 9.71 ± 4.49 mm and 40.39 ± 6.74 mm, respectively, from the first and second sacral transverse veins along the midline.

CONCLUSIONS

To preserve important vasculature, we recommend a 30 × 20-mm (L × W) avascular rectangular-shaped area, 10 mm below the SP and alongside the MSA, for safe graft or mesh attachment during sacrocolpopexy.

Advances in surgical strategies for prolapse

Pelvic floor dysfunctions are a complex condition in elderly women; pelvic organ prolapse, urinary or fecal incontinence, constipation, pelvic pain, and sexual dysfunction are common problems. The goal of surgical treatment is functional reconstruction with symptom management and repair of anatomic defects. The recent advancements in surgical treatment of pelvic floor dysfunction allow several good options for choosing the best surgery for each patient. The vaginal procedure is traditionally the gold standard approach for elderly patients, but abdominal surgery is increasing as a mini-invasive approach and the robotic approach is gaining acceptance for treatment of pelvic floor dysfunctions. In elderly individuals, a multitude of factors affects the final result of any reconstructive surgery such as postmenopausal or aging-associated changes in muscle tone and nerve function or changes in the function of the bladder or of the rectum: an understanding of the underlining functional status of pelvic organs is very important in aging women before proceeding to surgery. In this context, pelvic floor dysfunction, particularly in elderly women, should be addressed in a multidisciplinary manner and, at the forefront, centers for surgical planning could be helpful to perform safer, patient-tailored surgery.