Comparative outcome analysis of spinal anesthesia versus general anesthesia in lumbar fusion surgery

Spinal anesthesia (SA) has been shown in several studies to be a viable alternative to general anesthesia (GA) in laminectomies, discectomies, and microdiscectomies. However, the use of SA in spinal fusion surgery has been very scarcely documented in the current literature. Here we present a comparison of SA to GA in lumbar fusion surgery in terms of perioperative outcomes and cost.

The authors retrospectively reviewed the charts of all patients who underwent 1- or 2-level minimally invasive transforaminal lumbar interbody fusion (TLIF) surgery by a single surgeon, at a single institution, from 2015 to 2018. Data collected included demographics, operative and recovery times, nausea/vomiting, postoperative pain, and opioid requirement. Costs were included in the analysis if they were: 1) non-fixed; 2) incurred in the operating room (OR); and 3) directly related to patient care. All cost data represents net costs and was obtained from the hospital revenue cycle team. Patients were grouped for statistical analysis based on anesthetic modality.

A total of 29 patients received SA and 46 received GA. Both groups were similar in terms of age, gender, BMI, number of levels operated upon, preoperative diagnosis, and medical comorbidities. The SA group spent less time in the OR (163.86 ± 9.02 vs. 195.63 ± 11.27 min, p < 0.05), PACU (82.00 ± 7.17 vs. 102.98 ± 8.46 min, p < 0.05), and under anesthesia (175.03 ± 9.31 vs. 204.98 ± 10.15 min, p < 0.05) than the GA group. Post-surgery OR time was significantly less with SA than with GA (6.00 ± 1.09 vs. 17.26 ± 3.05 min, p < 0.05); however, pre-surgery OR time was similar between groups (50.17 ± 3.08 vs. 56.17 ± 5.34 min, p = 0.061). The SA group also experienced less maximum postoperative pain (3.31 ± 1.41 out of 10 vs. 5.96 ± 0.84/10, p < 0.05) and required less opioid analgesics (2.38 ± 1.37 vs. 5.39 ± 0.84 doses, p < 0.05). Both groups experienced similar nausea or vomiting rates and adverse events postoperatively. Net operative cost was found to be $812.31 (5.6%) less with SA than with GA, although this difference was not significant (p = 0.225).

To our knowledge, SA is almost never used in lumbar fusion, and a cost-effectiveness comparison with GA has not been recorded. In this retrospective study, we demonstrate that the use of SA in lumbar fusion surgery leads to significantly shorter operative and recovery times, less postoperative pain and opioid usage, and slight cost savings over GA. Thus, we conclude that this anesthetic modality represents a safe and cost-effective alternative to GA in lumbar fusion.