Retroperitoneoscopy of the presacral space in horses: Surgical access and anatomy

BACKGROUND

Surgical approaches to the equine rectum and perirectal area are described in the literature. However, surgeries in this region can be challenging.

OBJECTIVE

To describe the surgical anatomy of the presacral space and to evaluate its access using a retroperitoneoscopic approach.

STUDY DESIGN

Ex vivo experiment.

METHODS

Preliminary dissections were performed in two cadavers to define the boundaries of the presacral space and to determine portal locations for the surgical approach. After that, nine cadavers were used for experimental presacral retroperitoneoscopic procedure in a standing position. Following retroperitoneoscopy, cadavers were dissected to confirm the anatomical structures observed during the endoscopic procedures, to control the location of each portal and to record iatrogenic trauma.

RESULTS

The presacral space was bordered by the vertebral column from the ventral aspect of lumbosacral promontorium to the first coccygeal vertebra dorsally and by the presacral fascia and peritoneum ventrally. Lateral limits were composed of the sacrosciatic ligament and transversalis fascia. Cranial and caudal borders were composed of the peritoneum and coccygeal and levator ani muscles respectively. Retroperitoneoscopic portals were placed between the external anal sphincter and semimembranosus muscles and between the base of the tail and the external anal sphincter muscle through the anococcygeal fascia to enter the space by its caudal border. The retroperitoneal space was reached in all cases and the dorsal and lateral aspects of the rectum were visualised after creation of a working space.

MAIN LIMITATIONS

Use of cadaver specimens do not permit to evaluate the tolerance in living animals and the surgical complications such as rectal damage, haemorrhage and infection.

CONCLUSION

This study provides an anatomical description and surgical access of the presacral space with a minimal invasive approach. Retroperitoneoscopy allows access to the rectum and the dorsal aspect of the pelvis.

Caudal epidural catheterization for pain management in 48 hospitalized horses: A descriptive study of demographics, complications, and outcomes

The placement of caudal epidural catheters in horses has become more frequent as a multi-modal analgesic strategy. Despite its integration into clinical practice, there are limited reports describing the use of caudal epidural catheterization for prolonged use in horses. The purpose of this study was to characterize the hospitalized caseload undergoing epidural catheterization for long-term epidural analgesic administration, to report the response to epidural therapy and observed complications, and to describe patient outcomes. Medical records of hospitalized equine patients that underwent placement of a caudal epidural catheter for analgesic management between 2017 and 2021 were analyzed retrospectively. For the 62 catheters placed in the 48 cases, the most frequent diagnosis category prompting epidural analgesia was orthopedic (43/48, 89.6%). Synovial sepsis was the most frequent specific diagnosis prompting epidural catheter placement (11/48, 22.9%). The initial response to epidural therapy was characterized as positive for 37/62 (59.7%) catheters. Complications were documented for 46/62 (74.2%) catheters. However, most of these complications were classified as mild (51.6%) or moderate (14.5%), and exaggerated physiologic responses were observed most frequently. Of the horses studied, 52.1% survived to be discharged from the hospital. With awareness of potential complications and vigilant monitoring, caudal epidural catheters should be considered for equine patients as an analgesic strategy.