Thoracolumbar retrolaminar block in seven dogs undergoing spinal surgery

Abstract

Background Thoracolumbar intervertebral disc extrusion is a common neurologic complaint in dogs and is associated with debilitating pain that requires careful analgesic management to avoid the transition to a chronic pain state. Recently, there has been an increased effort to incorporate regional anaesthetic techniques whenever possible, both for perioperative analgesia management and for prevention of chronic pain. A novel regional anaesthetic technique named retrolaminar block is a fascial plane block where the local anaesthetic is injected directly on top of the dorsal aspect of the vertebral lamina, in the fascial plane between the lamina and the epaxial muscles. The technique was recently described in humans and it is claimed to provide analgesia in patients undergoing thoracic and lumbar procedures. To the authors’ knowledge, the retrolaminar block has not been previously reported in live dogs. Case presentation Seven dogs presented to our hospital for suspected thoracolumbar intervertebral disc extrusion were anaesthetised using an anaesthetic premedication and induction protocol tailored for each individual animal. Once the suspected diagnosis was confirmed, all seven dogs were placed in sternal recumbency, and the target thoracolumbar vertebral spinous process was identified with palpation. A unilateral retrolaminar block was performed in all dogs with 2 mg/kg of 0.25% bupivacaine. Physiologic parameters, as well as responses to nociceptive stimuli, were monitored throughout the anaesthetic event. Intraoperatively, one dog required a bolus of fentanyl to control nociceptive stimulation while the epaxial muscles were retracted. No further intraoperative rescue analgesia was required in any of the cases. The postoperative pain was assessed using the Short Form of Glasgow Composite Measure Pain Scale for dogs every four hours for the duration of the dogs’ hospitalization. The retrolaminar block reduced the intraoperative requirement for systemic opioids and other adjunct analgesic agents and all dogs were comfortable throughout their hospitalization and up until the time of their discharge. Conclusions This case report presents the performance of the retrolaminar block technique as part of multimodal analgesia management in seven dogs undergoing thoracolumbar spinal surgery.

Thoracolumbar Retrolaminar Block: Anatomical and Radiological Study of Injectate Pattern Distribution in Canine Cadavers

“…The performance of the landmark-guided retrolaminar block begins with the identification of the spinous process of the vertebra of interest, followed by the insertion of the needle through the surrounding paraspinal muscles, in a parasagittal plane, until it comes into contact with the dorsal aspect of the vertebral lamina, which is where the local anaesthetic is injected [13]. Recently, a case report described the successful application of the thoracolumbar retrolaminar block in seven dogs that underwent spinal surgery [24]. To the authors' knowledge, this is the first study that investigates the spread of the injectate following a retrolaminar injection in canine cadavers.…”

Comparison of Ultrasound-Guided Versus Anatomical Landmark-Guided Thoracolumbar Retrolaminar Techniques in Canine Cadavers

“…A previous study has evaluated the distribution pattern of two different injectate volumes following a thoracolumbar anatomical landmark-guided retrolaminar injection in greyhound cadavers [15]. Recently, the retrolaminar technique has also been performed as part of multimodal analgesia management in seven clinical canine patients undergoing thoracolumbar spinal surgery [16].…”