Reimagining Spine Surgery Through Awake Spinal Fusion

In a NASS 2018 session on outpatient spine surgery, Alok D. Sharan, MD, MHCDS, described how he changed his spine surgery practice to perform awake spinal fusions using spinal anesthesia in the outpatient setting, which led to improved outcomes and enhanced recovery time compared with performing these procedures under general anesthesia.

“Outpatient spine surgery is not just simply changing the site of where you do your surgery, it is redefining and rethinking of how we actually deliver care,” Dr. Sharan said at the NASS 2018 Meeting held September 26-29 in Los Angeles, CA. Dr. Sharan is Co-Director of the Westmed Spine Center in Yonkers, NY.
Use of spinal anesthesia in outpatient spine surgery is changing more than where procedures are performed. Photo Credit: 123RF.com.Dr. Sharan and his team began performing the vast majority of MIS laminectomies under spinal anesthesia in part as a response to studies showing an increased risk for post-operative delirium in elderly patients undergoing spinal surgery who receive general anesthesia. An analysis of outcomes from 150 patients who underwent awake MIS laminectomies at his spine center showed dramatic pain relief compared with cases performed using general anesthesia (Figure 1A). Improved pain scores equated to reduced use of opioids (Figure 1B), which in turn resulted in less constipation, nausea, and vomiting.
Figure 1. Post-operative pain (A) and opioid use (B) after minimally invasive laminectomy/discectomy by anesthesia type. Source: Sharan, et al.
In addition, the researchers found that patients could position their arms and shoulders themselves more comfortably during surgery, reducing post-operative shoulder pain. Furthermore, patients tend to have a better experience during awake surgery with lower rates of fear and anxiety, in Dr. Sharan’s experience.

In terms of cost effectiveness, Dr. Sharan and colleagues found an approximately 10% savings with spinal versus general anesthesia for lumbar laminectomy or microdiscectomy (P=0.040).¹ Much of that savings was accounted for by reduced operating room (OR) costs, as well as issues related to time (eg, time spent in the OR, post-anesthesia care unit [PACU], and hospital).

Awake Spinal Fusions Linked to Improved Pain Relief
Dr. Sharan and his team then applied the principles of awake surgery to TLIF surgery, and found that minimally invasive TLIF surgery performed under spinal anesthesia (ie, 0.5% bupivacaine and 1.5-2.0 cc fentanyl) reduced maximum post-operative pain scores by nearly 50% compared with fusion performed under general anesthesia (3.31 vs 5.96; Figure 2A). In addition, hospital length of stay was reduced from 1.4 days with general anesthesia to 1.1 days with spinal anesthesia.

Additional benefit was gained from adding ultrasound-guided thoracolumbar interfascial plane (TLIP) blocks (60 cc bupivacaine on each side) plus spinal anesthesia, which further reduced maximum post-operative pain scores following TLIF to 2.31 and length of stay to 0.74 days (Figure 2B).
Figure 2. Maximum post-operative pain (A) and length of hospital stay (B) after TLIF by anesthesia type. Source: Sharan, et al.
On the day of surgery, patients also receive the following pain protocol:

• Oxycodone 10 mg orally pre-operatively
• Lidocaine with epinephrine subcutaneously pre-operatively
• Diazepam 1 hour after arrival in PACU
• Tramadol 50 mg orally every 4 hours
• Acetaminophen intravenously

Patients are discharged with a 7-day prescription for hydrocodone/acetaminophen and a muscle relaxant.

Currently, 66 patients have undergone awake spinal fusion (spinal anesthesia plus TLIP block) under the care of Dr. Sharan and his team, none of whom have required a conversion to general anesthesia or redosing of the spinal anesthesia. Overall length of stay was 0.8 days. Two readmissions occurred, including one patient who developed pneumonia 1 week post-operatively and one patient who developed an infection.

System-Wide Approach to Change in Spinal Fusions
To achieve these improved outcomes, the researchers considered the interrelatedness of all steps in the surgical process. For example, with the goal of enhancing recovering and improving time to mobilization in patients undergoing awake lumbar fusion surgery in the outpatient setting, the team realized they needed to first make sure that patients had a ride home and in-home social support, and that nurses on the floor were properly educated about the need for fast mobilization.

“I would strongly recommend trying to perform your outpatient cases in the hospital first before moving cases to an ambulatory surgical center,” Dr. Sharan said. “It is critical that you develop your own pre-operative risk stratification questionnaire, and understand what kind of things the patients need before they can go home.”

In addition, Dr. Sharan emphasized the importance of developing predictable times in the OR as surgeons move towards performing lumbar spine fusion in the outpatient spine surgery.

“We are religious about monitoring our times during different segments of the operation, and are constantly trying to improve and figure out where we can slice out any time and develop predictable workflows,” Dr. Sharan concluded. Since patients are under spinal anesthesia, developing predictable times for doing a surgery becomes even more important, he said.

“Currently, there is a movement to institute ERAS (enhanced recovery after surgery) protocols for all types of surgery,” Dr. Sharan told SpineUniverse. “The Awake Spinal Fusion procedure represents an adaptation of ERAS for spine surgery.”

Disclosures
Dr. Sharan reported the following disclosures: Royalties: Jaypee Publishers; Stock Ownership: Medtel, ReVivo; Consulting: Cartiva, DePuy, McKinsey, NuVasive; Speaking and/or teaching arrangements: Globus Medical; Trips/travel: Globus Medical; Scientific Advisory Board: ReVivo; Other: Jaypee Brothers.