The effects of foraminotomy and intervertebral distraction on the volume of the lumbosacral intervertebral neurovascular foramen: An ex vivo study

Evaluation of window trajectory in trans-iliac foraminotomy using an individualised 3D printing guide in cadaveric dogs

IMPORTANCE

In veterinary orthopedics, addressing foramen stenosis in the L7-S1 region in dogs presents significant challenges due to limited access and visualization with conventional surgical techniques.

OBJECTIVE

This study aims to evaluate endoscopic foraminotomy through the iliac window, using three-dimensionally (3D) printing guide based on the preoperative plan, in cadaveric dogs.

METHODS

Trans-iliac foraminotomies were performed on each side of five canine cadavers using and individualized 3D printing guide. The intervertebral foramen (IVF) area was divided into entrance, middle, and exit zones and the trajectory angle was calculated from the computed tomography data.

RESULTS

Trans-iliac foraminotomy with an endoscope through the iliac hole using a 3D printed guide provide good visual access to the L7-S1 region. The variations in IVF in three zones were not significantly different after surgery. The angle of deviation of the guide was not significantly different caudally or ventrally after surgery. The mean trajectory angle after surgery was 14.06 ± 4.61°caudally and 13.07 ± 6.79° ventrally.

CONCLUSIONS AND RELEVANCE

Our results suggest that surgical site were directly visualized during foraminotomy by the lateral approach through the spinal endoscope. However, other procedure including corpectomy and discectomy were not performed in this study.

Neurogenic Bladder in Dogs, Cats and Humans: A Comparative Review of Neurological Diseases

Lower urinary tract disease (LUTD) includes abnormalities in the structure and function of the bladder and the urethra. LUTD caused by neurological disease is defined neurogenic bladder (NB). The integrity of the central nervous system (CNS) and peripheral nervous system (PNS) is required to explicate normal micturition, maintaining the proper function of bladder and urethra. The location and type of neurological lesions influence the pattern of clinical manifestations, potential treatment, and prognosis. Though, in dogs and cats, spinal cord injury is considered mainly responsible for bladder and/or urethra incompetence, other disorders, congenital or acquired, involving CNS or PNS, could play a role in NB. In veterinary medicine, the information about the epidemiology, prevalence, etiopathogenesis, diagnosis and treatment of NB are scattered. The aim of this study is to provide an overview of the epidemiology, prevalence, clinical findings, diagnosis and prognosis for NB in dogs and cats compared with humans.

Distraction Stabilization of Degenerative Lumbosacral Stenosis: Technique and Mid- to Long-Term Outcome in 30 Cases

OBJECTIVE

 To describe the dorsal laminectomy, annulectomy and distraction stabilization with pins and polymethylmethacrylate technique, its complications and outcome in the management of canine degenerative lumbosacral stenosis. To determine pre- and post-surgical foraminal width and vertebral step changes.

STUDY DESIGN

 Multi-institutional retrospective clinical study.

METHODS

 Medical records (2005-2020) of dogs treated (n = 30). Clinical signs, Modified Frankel Score, Texas Spinal Cord Injury Score, pain score (dorsal palpation of spine, tail dorsiflexion), imaging findings and complications were retrieved pre-operatively, perioperatively and at long-term follow-up.

RESULTS

 The most common presurgical imaging findings were disc protrusion (24/25) and sclerosis of the caudal end-plate of L7 (23/30). On short- to long-term assessment 18 out of 21 dogs exhibited clinical improvement and all exhibited improved pain scores (p < 0.0001). Catastrophic complications occurred in 3 dogs, and major complications occurred in 5, of which 3 required additional surgery. Mean lumbosacral step defect reduced 60% (1.8 mm ± 2.5 mm pre-surgery to 0.7mm ± 0.9mm post-surgery, p = 0.1585). Mean foraminal width significantly increased 50% long-term (3.3 mm ± 1.0 mm pre-surgery to 5.0 mm ± 0.9 mm post-surgery, p < 0.0001).

CLINICAL SIGNIFICANCE

 Dorsal laminectomy, annulectomy and distraction stabilization is a complex procedure which can significantly increase foraminal width, reduce pain and improve gait characteristics in dogs in the short- to long-term, and should be performed by surgeons experienced in lumbosacral pin placement.