Surgical anatomy, transperitoneal approach, and early postoperative complications of a ventral lumbar spine surgical model in Lewis rats.

Surgical models in animals are used extensively to study small molecules and devices for lumbar intervertebral disc repair, replacement, and fusion. Although the ventral lumbar animal models themselves are well described, critical assessment of morbidity and mortality avoidance when using the models have not been reported. Hypothesizing that technique modifications and the relative prevalence and severity of complications would be correlated, we collected and examined peri- and postoperative data stratified by surgical technique. We here report complications associated with the transperitoneal approach to the lumbar spine in 268 Lewis rats and offer data-driven suggestions regarding complication avoidance through technique modification. Compared with wider exposure, limiting the width of exposure to a maximum of 3 mm resulted in fewer neurologic complications in the lower limbs. In addition, avoiding extracorporeal reflection of the small intestine during the exposure was associated with lower incidence of postoperative gastrointestinal distress and fewer situations requiring euthanasia. These findings underscore the importance of detailed approaches in minimizing postoperative morbidity and attrition in surgical models.