I'll be presenting the work entitled Spinal versus General Anesthesia for Minimally Invasive Transforaminal Lumbar Interbody Fusion, MIS-T Lift, Implications on OR Time, Pain, and Ambulation. I'm Gaetano De Biase, and I'm a postdoctoral fellow in the Department of Neurosurgery here at the Mayo Clinic in Florida, Jacksonville. We do not have any disclosures related to this work. So transforaminal lumbar interbody fusion is a surgical technique frequently used to address many spinal pathologies. And with the goal of improving outcomes and accelerating patient recovery, recently there has been an increased interest in the adoption of spinal anesthesia in spine surgery, especially for laminectomy and discectomy. In particular, we did enhanced recovery after surgery ERAS protocols. Several studies looking at spinal versus general anesthesia in lumbar laminectomy and discectomy have found that spinal anesthesia reduces preoperative costs by reducing drug consumption and leads to a reduction in analgesic use, shorter anesthesia and surgical time, reduced blood loss, and less postoperative nausea and vomiting. To the best of our knowledge, no studies have looked at the preoperative outcomes and potential benefits of spinal anesthesia in minimally invasive transforaminal lumbar interbody fusion. This retrospective case control study was conducted to compare the preoperative outcomes of patients undergoing MIS-T Lift under spinal versus general anesthesia. We analyzed 40 opioid-naive patients undergoing MIS-T Lift for lumbar degenerative disc disease, spinal stenosis, or degenerative spondylolisthesis grade 1 or 2 by a single surgeon, the senior author Dr. Abudiyama. We looked at 20 consecutive patients that underwent MIS-T Lift under spinal anesthesia from February 2020 to September 2020, and the control group consisted of 20 consecutive patients that underwent MIS-T Lift under general anesthesia by the same surgeon from July 2019 to February 2020, before we adopted spinal anesthesia for MIS-T Lift. At our institution, we started doing MIS-T Lift under spinal anesthesia in February 2020 and routinely offering it to patients unless they met any of these exclusion criteria, history of seizure or intracranial hypertension, coagulopathy, infection at the site of needling, hypovolemia, severe spinal stenosis, severe respiratory problems. To minimize selection bias, the charts of the general anesthesia group were reviewed by an anesthesiologist to ensure that they did not meet any of the exclusion criteria for spinal anesthesia. Our spinal anesthesia protocol included intravenous midazolam, commonly administered as a pre-medication, and then in the OR, after application of subcutaneous local anesthesia, a spinal needle was introduced between the L3-4 or L4-5 l-triple space under sterile condition and isobaric bupivacaine slowly injected in the subarachnoid space. After that, the patient was positioned on the Wilson frame and light sedation was commonly administered. For each patient, we collected total OR time, total procedure time, time to leave the OR, and intraoperative adverse events, intraoperative EBL, postoperative adverse events, and postoperative length of stay. We also recorded all the pain medications received during the first three hours in the PACU, as well as numeric rating scale pain scores during the first three hours in the PACU, and also time to ambulation. There was no statistically significant difference in age, sex, BMI, and prevalence of diabetes, hypertension, obstructive sleep apnea, ASA score between the general anesthesia and the spinal anesthesia group, as well as the number of re-operated levels. We observed a significant decrease in total OR time for patients that underwent surgery under spinal anesthesia, with 156 average time for spinal anesthesia versus 213 for the general anesthesia group, a mean reduction of 27%. We also observed a significant reduction in total procedure time. No statistically significant difference was observed in mean arterial blood pressure, but we did observe a difference in mean intraoperative heart rate. There was a significant difference in maximum pain score during the first three hours in the PACU, as well as mean numeric pain scores, with the spinal anesthesia scoring lower than the general anesthesia group. And no significant difference was observed between the groups in total morphine equivalents received during the first three hours in the PACU. A significant difference was observed in time to first ambulation, with the spinal anesthesia groups ambulating on average after 385 minutes versus 855 for the general anesthesia group. Spinal anesthesia is gaining increased popularity as an alternative to general anesthesia for spine surgery. And the present case control study, DOOR Retrospective, represents the first single-surgeon series comparing spinal anesthesia versus general anesthesia for MIS-T Lyft. Our study validates what was observed for lumbar laminectomies and discectomy, that spinal anesthesia for MIS-T Lyft offers some unique advantages. Spinal anesthesia significantly reduced both total OR time and total procedure time. Limitations of the study are related to its retrospective nature. Although every effort was made to ensure that the case complexity was comparable, there is possibility for selection bias, as the anesthesia technique was not randomized and left to patient preference. In conclusion, our study demonstrates that spinal anesthesia is an effective technique for performing MIS-T Lyft, offering unique advantages to general anesthesia, including reduced postoperative pain, reduced OR time, and faster postoperative mobilization. Thank you.

Spinal anesthesia

General anesthesia

MIS-T Lift

OR time

Postoperative pain