Lateral Approach to the Lumbar Spine of Sprague Dawley Rat: Development of a Novel Animal Model for Spine Surgery

Abstract

Background: Low back pain is a common ailment affecting individuals all around the globe. Animal models are required to study and further explore the treatment modalities. Lumbar spinal surgeries and disc repair is an important tissue engineering research domain. Dorsal and ventral approaches to access rat spine have been traditionally performed but suffer from a number of shortcomings such as higher morbidity, loss of neurology, high postoperative pain, and longer surgery. Methods: We used ten male Sprague Dawly rats, 3 months of age, and weighing an average of 280 gm. The surgeries were performed under dissociative anesthesia (ketamine: 50 mg/kg body weight). The spine was approached by left lateral incision extending from iliac crest and centering the level to be exposed. Skin and subcutaneous tissues were cut, external and internal oblique muscles were split in the direction of fibers, transverse abdominis was split vertically, and psoas was sacrificed. This made the spine and disc levels visible from the left lateral aspect. The muscles were approximated, and skin was closed with nonabsorbable mattress sutures. Postoperative analgesics (meloxicam 5 mg/kg body weight) and antibiotics (ceftriaxone 30 mg/kg body weight) were used. Results: This work has led to the development of a novel in vivo rat model using lateral retroperitoneal approach. This approach provides less pain and faster recovery in the postoperative stage. Moreover, it allows easy exposure and little surgery-related peri- or post-operative complications. Conclusion: Lateral retroperitoneal approach is a novel and safe method of spinal exposure in rats which may pave way for various live rat spine surgery models and experiments in future.

Keywords

• animal morbidity
• lateral approach
• spine model
• sprague dawley rat