Characterization of the median sacral artery course at the sacral promontory using contrast-enhanced computed tomography

Intraoperative Fluorescent Navigation of the Ureters, Vessels, and Nerves during Robot-Assisted Sacrocolpopexy

In this study, we aimed to demonstrate the feasibility and safety of navigating the ureters, middle sacral artery (MSA), and superior hypogastric nerve (SHN) using indocyanine green (ICG) and near-infrared fluorescence (NIRF) imaging during robot-assisted sacrocolpopexy (RSCP). Overall, 15 patients who underwent RSCP for apical vaginal prolapse were retrospectively enrolled. All patients underwent cystoscopic intraureteric instillation of 5 cc ICG (2.5 mg/mL) before RSCP and intravenous injection of 3 cc ICG during presacral dissection and mesh fixation. In all patients, the fluorescent right ureter was clearly identified in real time. The MSA was visualized on ICG-NIRF images in 80% (13/15) of patients. The mean time from ICG injection to MSA visualization was 43.7 s; the mean duration of the arterial phase was 104.3 s. Fluorescent SHN was detected in 73.3% (11/15) of patients. The time from ICG injection to SHN fluorescence was 48.4 s; the duration of fluorescence was 177.2 s. There was no transfusion, iatrogenic ureteral injury, or bowel or urinary dysfunction. Our results indicated that intraoperative ureter, MSA, and SHN mapping using ICG-NIRF images during RSCP is a valuable and safe technique to avoid iatrogenic ureteral, vascular, and neural injuries and to simplify surgical procedures. Nonetheless, further studies are required.

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.

Fetal median sacral artery anatomy study by micro-CT imaging

PURPOSE

The median sacral artery (MSA) is the termination of the dorsal aorta, which undergoes a complex regression and remodeling process during embryo and fetal development. The MSA contributes to the pelvic vascularization and may be injured during pelvic surgery. The embryological steps of MSA development, anastomosis formation and anatomical variations are linked, but not fully understood.

METHODS

The pelvic vascularization and more precisely the MSA of a human fetus at 22 weeks of gestation (GW) were studied using micro-CT imaging. Image treatment included arterial segmentations and 3D visualization.

RESULTS

At 22 GW, the MSA was a well-developed straight artery in front of the sacrum and was longer than the abdominal aorta. Anastomoses between the MSA and the internal pudendal arteries and the superior rectal artery were detected. No evidence was found for the existence of a coccygeal glomus with arteriovenous anastomosis.

CONCLUSIONS

Micro-CT imaging and 3D visualization helped us understand the MSA central role in pelvic vascularization through the ilio-aortic anastomotic system. It is essential to know this anastomotic network to treat pathological conditions, such as sacrococcygeal teratomas and parasitic ischiopagus twins (for instance, fetus in fetu and twin-reversed arterial perfusion sequence).