Awake spinal surgery: simplifying the learning curve with a patient selection algorithm

Current Status of Awake Spine Surgery: A Bibliometric Analysis

BACKGROUND

Spine surgery accounts for a large proportion of neurosurgical procedures, with approximately 313 million spine surgeries conducted annually worldwide. Considering delayed recovery and postoperative complications that are commonly reported, there has been a recent shift toward minimally invasive spine procedures conducted under local anesthesia. Despite proven success, there exists a limited body of literature on the use of awake surgery in spinal procedures.

METHODS

A bibliometric analysis was conducted to map the current landscape of work in this field. 190 articles were identified from the Web of Science (Clarivate, NY) database. A comprehensive bibliometric analysis was performed on a narrowed list of the most relevant articles using Bibliometrix, an R-based programming tool.

RESULTS

There has been a rise in academic papers published on the topic of awake spine surgery since 2016, with an increase in publication count by approximately 18% annually and each article cited approximately ten times on average to date. The year 2022 saw an uptick in publications, with 9 throughout the entire year. The most impactful article, with a total of 95 citations, was published by Sairyo et al.1 Thematic analysis revealed that the terms "lumbar spine" and "stenosis" are well-developed topics in the literature, whereas the topics of "complications," "fusion," and "cost-analysis" are less well-developed topics.

CONCLUSIONS

This study provides a comprehensive overview of the most-cited articles in the field of awake spine surgery. Specifically, it identifies areas that are well represented in the literature and those which are underrepresented and should be areas of continued future research.

New Frontiers in Wide-Awake Surgery

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Explain the most important benefits of wide-awake surgery to patients. 2. Tumesce large parts of the body with minimal pain local anesthesia injection technique to eliminate the need for sedation for many operations. 3. Apply tourniquet-free surgery to upper and lower limb operations to avoid the sedation required to tolerate tourniquet pain. 4. Move many procedures out of the main operating room to minor procedure rooms with no increase in infection rates to decrease unnecessary cost and solid waste in surgery.

SUMMARY

Three disruptive innovations are changing the landscape of surgery: (1) minimally painful injection of large-volume, low-concentration tumescent local anesthesia eliminates the need for sedation for many procedures over the entire body; (2) epinephrine vasoconstriction in tumescent local anesthesia is a good alternative to the tourniquet and proximal nerve blocks in extremity surgery (sedation for tourniquet pain is no longer required for many procedures); and (3) evidence-based sterility and the elimination of sedation enable many larger procedures to move out of the main operating room into minor procedure rooms with no increase in infection rates. This continuing medical education article explores some of the new frontiers in which these changes affect surgery all over the body.

Comparative outcomes of awake spine surgery under spinal versus general anesthesia: a comprehensive systematic review and meta-analysis

BACKGROUND

Awake surgery, under spinal anesthesia (SA), is an alternative to surgery under general anesthesia (GA), in neurological and spine surgery. In the literature, there seem to be some evidence supporting benefits associated with the use of this anesthetic modality, as compared to GA. Currently, there is a notable lack of updated and comprehensive review addressing the complications associated with both awake SA and GA in spine surgery. We hence aimed to perform a systematic review of the literature and meta-analysis on the topic.

METHODS

A systematic search was conducted to identify studies that assessed SA in spine surgery from database inception to April 14, 2023, in PubMed, Medline, Embase, and Cochrane databases. Outcomes of interest included estimated blood loss, length of hospital stay, operative time, and overall complications. Meta-analysis was conducted using random effects models.

RESULTS

In total, 38 studies that assessed 7820 patients were included. The majority of the operations that were treated with SA were single-level lumbar cases. Awake patients had significantly shorter lengths of hospital stay (Mean difference (MD): - 0.40 days; 95% CI - 0.64 to - 0.17) and operative time (MD: - 19.17 min; 95% CI - 29.68 to - 8.65) compared to patients under GA. The overall complication rate was significantly higher in patients under GA than SA (RR, 0.59 [95% CI 0.47-0.74]). Patients under GA had significantly higher rates of postoperative nausea/vomiting RR, 0.60 [95% CI 0.39-0.90]) and urinary retention (RR, 0.61 [95% CI 0.37-0.99]).

CONCLUSIONS

Patients undergoing awake spine surgery under SA had significantly shorter operations and hospital stays, and fewer rates of postoperative nausea and urinary retention as compared to GA. In summary, awake spine surgery offers a valid alternative to GA and added benefits in terms of postsurgical complications, while being associated with relatively low morbidity.

General Versus Nongeneral Anesthesia for Spinal Surgery: A Comparative National Analysis of Reimbursement Trends Over 10 Years

BACKGROUND AND OBJECTIVES

Nongeneral anesthesia (non-GA) spine surgery is growing in popularity and has facilitated earlier postoperative recovery, reduced cost, and fewer complications compared with spine surgery under general anesthesia (GA). Changes in reimbursement policies have been demonstrated to correlate with clinical practice; however, they have yet to be studied for GA vs non-GA spine procedures. We aimed to investigate trends in physician reimbursement for GA vs non-GA spine surgery in the United States.

METHODS

We queried the ACS-NSQIP for GA and non-GA (regional, epidural, spinal, and anesthesia care/intravenous sedation) spine surgeries during 2011-2020. Work relative value units per operative hour (wRVUs/h) were retrieved for decompression or stabilization of the cervical, thoracic, and lumbar spine. Propensity score matching (1:1) was performed using all baseline variables.

RESULTS

We included 474 706 patients who underwent spine decompression or stabilization procedures. GA was used in 472 248 operations, whereas 2458 operations were non-GA. The proportion of non-GA spine operations significantly increased during the study period. Operative times ( P < .001) and length of stays ( P < .001) were shorter in non-GA when compared with GA procedures. Non-GA lumbar procedures had significantly higher wRVUs/h when compared with the same procedures performed under GA (decompression; P < .001 and stabilization; P = .039). However, the same could not be said about cervicothoracic procedures. Lumbar decompression surgeries using non-GA witnessed significant yearly increase in wRVUs/h ( P < .01) contrary to GA ( P = .72). Physician reimbursement remained stable for procedures of the cervical or thoracic spine regardless of the anesthesia.

CONCLUSION

Non-GA lumbar decompressions and stabilizations are associated with higher and increasing reimbursement trends (wRVUs/h) compared with those under GA. Reimbursement for cervical and thoracic surgeries was equal regardless of the type of anesthesia and being relatively stable during the study period. The adoption of a non-GA technique relative to the GA increased significantly during the study period.

Awake Unilateral Biportal Endoscopic Decompression Under Local Anesthesia for Degenerative Lumbar Spinal Stenosis in the Elderly: A Feasibility Study with Technique Note

Purpose

Here, we introduce a novel strategy of awake unilateral biportal endoscopic (UBE) decompression, which applies conscious sedation combined with stepwise local anesthesia (LA) as an alternative to general anesthesia (GA). The study aims to evaluate the feasibility of awake UBE decompression for degenerative lumbar spinal stenosis (DLSS) in elderly patients.

Patients and Methods

This retrospective study included 31 consecutive patients who received awake UBE decompression for DLSS in our institution from January 2021 to March 2022. Clinical results were evaluated using patient-reported outcomes measures (PROM) including visual analog scale for leg pain (VAS-LP), Oswestry Disability Index (ODI), and modified MacNab criteria. The anesthesia effectiveness and intraoperative experience were evaluated by intraoperative VAS and satisfaction rating system.

Results

UBE decompression was successfully performed in all patients under LA combined with conscious sedation. 26 (83.9%) patients rated the intraoperative experience as satisfactory (excellent or good) and 5 (16.1%) as fair. The mean intraoperative VAS was 3.41±1.26. The VAS and ODI at each follow-up stage after surgery were significantly improved compared to preoperative scores (p < 0.01). At the last follow-up, 28 patients (90.3%) classified the surgical outcome as good or excellent, and 3 (9.7%) as fair. There were no serious complications or adverse reactions observed in the study.

Conclusion

Our preliminary results suggest that awake UBE decompression is a feasible and promising alternative for elderly patients with DLSS.

Art and Neurosurgery: The Importance of Medical Illustration

Art in neurosurgery has been a critical part of the discipline for centuries. Numerous cultures, such as ancient India, China, and Egypt, and more contemporary scientists, such as Leonardo da Vinci, Max Brödel, and Norman Dott, have significantly contributed to medical illustration. Today, advancements in three-dimensional technology have allowed for the creation of detailed neuroanatomy models for surgical planning and education. Medical illustrations are also used for research and outcome documentation as they help visualize anatomy and surgical procedures. Its use in education, surgical planning, and navigation remains integral to the advancement of neurosurgery. This review demonstrates the invaluable contribution of art in neurosurgery and how it has enabled continuous progress in the field.

Spinal anesthesia in elective lumbar spinal surgery

Spinal anesthesia (SA) is gaining recognition as a safe and efficacious regional alternative to general anesthesia for elective lumbar surgery. However, unfamiliarity with management issues related to its use has limited the adoption of awake spine surgery, despite its benefits. Few centers in the United States routinely offer SA for elective lumbar surgery, and a comprehensive workflow to standardize SA for lumbar surgery is lacking. In this article, we examine recent literature on the use of SA in lumbar surgery, review the experience of our institution with SA in lumbar surgery, and provide a cohesive outline to streamline the implementation of SA from the perspective of the anesthesiologist. We review the critical features of SA in contemporary lumbar surgery, including selection of patients, methods of SA, intraoperative sedation, and management of several important technical considerations. We aimed to flatten the learning curve to improve the availability and accessibility of the technique for eligible patients.

Regional anesthesia in spine surgery: A narrative review

Background: Regional anesthesia, which refers to the use of anesthetics to provide analgesia to a specific body part or nervous innervation territory, has become increasingly popular in the field of spine surgery. With the application of these techniques, it has been postulated that patients will require less systemic analgesia, intraoperatively and postoperatively. The authors of this narrative review discuss the common regional anesthetic modalities applied to spine surgery, in addition to patient selection criteria, success in patients with multiple comorbid illnesses, and its adoption by surgeons. Materials and Methods: An advanced search was performed in the PubMed database to obtain Englishlanguage articles discussing regional anesthesia, awake spine surgery, and postoperative complications. Articles were screened for relevance, and 47 articles were incorporated into this narrative review. Results: Classic neuraxial and paraspinal techniques have allowed surgeons to perform posterior decompression, fusion, and revision procedures. Transversus abdominus plane and quadratus lumborum blocks have enabled better pain control in patients undergoing surgeries requiring anterior or lateral approaches. Documented benefits of regional anesthesia include shorter operative time, improved pain control and hemodynamic stability, as well as decreased cost and length of stay. Several case series have demonstrated the success of these techniques in highly comorbid patients. Conclusion: Regional anesthesia provides an exciting opportunity to make surgical treatment possible for spine patients with significant comorbidities. Although additional randomized controlled trials are necessary to further refine patient selection criteria, current data demonstrates its safety and efficacy in the operating room.

Intraoperative Triggered Electromyography for Pedicle Screw Placement Under Spinal Anesthesia: A Preliminary Report

BACKGROUND

Triggered electromyography (tEMG) is an intraoperative neuromonitoring technique used to assess pedicle screw placement during instrumented fusion procedures. Although spinal anesthesia is a safe alternative to general anesthesia in patients undergoing lumbar fusion, its use may potentially block conduction of triggered action potentials or may require higher threshold currents to elicit myotomal responses when using tEMG. Given the broad utilization of tEMG for confirmation of pedicle screw placement, adoption of spinal anesthesia may be hindered by limited studies of its use alongside tEMG.

OBJECTIVE

To investigate whether spinal anesthesia affects the efficacy of tEMG, we compare the baseline spinal nerve thresholds during lumbar fusion procedures under general vs spinal anesthesia.

METHODS

Twenty-three consecutive patients (12 general and 11 spinal) undergoing single-level transforaminal lumbar interbody fusion were included in the study. Baseline nerve threshold was determined through direct stimulation of the spinal nerve using tEMG.

RESULTS

Baseline spinal nerve threshold did not differ between the general and spinal anesthesia cohorts (3.25 ± 1.14 vs 3.64 ± 2.16 mA, respectively; P = .949). General and spinal anesthesia cohorts did not differ by age, body mass index, American Society of Anesthesiologists score status, or surgical indication.

CONCLUSION

We report that tEMG for pedicle screw placement can be safely and effectively used in procedures under spinal anesthesia. The baseline nerve threshold required to illicit a myotomal response did not differ between patients under general or spinal anesthesia. This preliminary finding suggests that spinal anesthetic blockade does not contraindicate the use of tEMG for neuromonitoring during pedicle screw placement.

Determining Contemporary Barriers to Effective Multidisciplinary Team Meetings in Neurological Surgery: A Review of the Literature

OBJECTIVE

The integration of multidisciplinary team meetings (MDTMs) for neurosurgical care has been accepted worldwide. Our objective was to review the literature for the limiting factors to MDTMs that may introduce bias to patient care.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analysis was used to perform a literature review of MDTMs for neuro-oncology, pituitary oncology, cerebrovascular surgery, and spine surgery and spine oncology. Limiting factors to productive MDTMs and factors that introduce bias were identified, as well as determining whether MDTMs led to improved patient outcomes.

RESULTS

We identified 1264 manuscripts from a PubMed and Ovid Medline search, of which 27 of 500 neuro-oncology, 4 of 279 pituitary, and 11 of 260 spine surgery articles met our inclusion criteria. Of 224 cerebrovascular manuscripts, none met the criteria. Factors for productive MDTMs included quaternary/tertiary referral centers, nonhierarchical environment, regularly scheduled meetings, concise inclusion of nonmedical factors at the same level of importance as patient clinical information, inclusion of nonclinical participants, and use of clinical guidelines and institutional protocols to provide recommendations. Our review did not identify literature that described the use of artificial intelligence to reduce bias and guide clinical care.

CONCLUSIONS

The continued implementation of MDTMs in neurosurgery should be recommended but cautioned by limiting bias.

The "In-Parallel" Technique for Awake, Bilateral Simultaneous Minimally Invasive Transforaminal Lumbar Interbody Fusion and Multilevel Lumbar Decompression

BACKGROUND

Minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) and MIS lumbar decompression have been successfully undertaken in the absence of general anesthesia in well-selected patients. By leveraging spinal anesthesia, surgeons may safely conduct surgeries on one- or two-level lumbar pathology. However, surgeries on more extensive pathology have not yet been described, because of concerns about the duration of efficacy of spinal anesthetic in the awake patient.

OBJECTIVE

To report the use of a novel awake technique for "in parallel," simultaneous lumbar spinal surgery on three-segment pathology.

METHODS

We describe concurrent performance of a dual microscopic, navigated MIS TLIF and MIS two-level decompression, using a combination of liposomal bupivacaine erector spinae block in conjunction with a spinal anesthetic.

RESULTS

We show that a left-sided, two-level MIS tubular microscopic decompression combined with a concurrent right-sided, transfacet MIS TLIF via a tubular microscopic approach was well tolerated in an 87-year-old patient with multilevel lumbar stenosis with a mobile spondylolisthesis.

CONCLUSION

We provide the first description of a dual-surgeon approach for minimally invasive spine surgery. This "in-parallel" technique-reliant on 2, independent spine surgeons-may aid in the performance of surgeries previously considered too extensive, given the time constraints of regional anesthesia and can be successfully applied to patients who otherwise may not be candidates for general anesthesia.

A Second Prone Dose Algorithm for Patients Undergoing Spinal Anesthesia During Thoracolumbar Surgeries

BACKGROUND

Spinal anesthesia is safe and effective in lumbar surgeries, with numerous advantages over general anesthesia (GA). Nevertheless, 1 major concern preventing the widespread adoption of this anesthetic modality in spine surgeries is the potential for intraprocedural anesthetic failure, resulting in the need to convert to GA intraoperatively.

OBJECTIVE

To present a novel additional prone dose algorithm for when a first spinal dose fails to achieve the necessary effect.

METHODS

A total of 422 consecutive patients undergoing simple and complex thoracolumbar surgeries under spinal anesthesia were prospectively enrolled into our database. Data were retrospectively collected through extraction of electronic health records.

RESULTS

Sixteen of 422 required a second prone dose, of whom 1 refused and was converted to GA preoperatively. After 15 were given a prone dose, only 2 required preoperative conversion to GA. There were no instances of intraoperative conversion to GA. The success rate for spinal anesthesia without the need for conversion rose from 96.4% to 99.5%. In patients who required a second prone dose, there were no instances of spinal headache, deep vein thrombosis, pneumonia, urinary tract infection, urinary retention, readmission within 30 days, acute pain service consult, return to operating room, durotomy, or cerebrospinal fluid on puncture.

CONCLUSION

Use of an additional prone dose algorithm was able to achieve a 99.5% success rate, and those who received this second dose did not experience any complications or negative operative disadvantages. Further research is needed to investigate which patients are at increased risk of inadequate analgesia with spinal anesthesia.

Assessment of surgeons' attitude towards awake spine surgery under spinal anesthesia

BACKGROUND

General anesthesia (GA) and spinal anesthesia (SA) have been adopted for lumbar spine surgery (LSS), but GA is used far more widely. We conducted a survey of spine surgeons to explore their attitudes and preferences regarding awake spine surgery under SA.

METHODS

A survey was emailed to 150 spine surgeons. Exposure and attitudes towards spine surgery under SA were elicited. A five-point Likert scale of agreement examined perceptions of SA, while attitudes towards SA were recorded by categorizing free text into themes.

RESULTS

Seventy-five surgeons completed the survey, 50 % response rate. Only 27 % said they perform LSS under SA. Most surgeons, 83 %, would recommend GA to a healthy patient undergoing lumbar laminectomy. Only 41 % believes SA to be as safe as GA, and only 30 % believes SA is associated with better postoperative pain control. The most common reasons why SA is not favored was lack of proven benefits over GA (65 %). When asked if a randomized trial finds SA to lead to less postoperative fatigue, 50 % said they would be more likely to offer SA, a significant increase from the baseline response of 27 % (p = 0.002).

CONCLUSIONS

Our survey indicates that the low adoption of SA for LSS is due to lack of surgeons' belief in the benefits of SA over GA, and that a randomized patient-centered trial has the potential of changing surgeons' perspective and increasing adoption of SA for LSS.

How to start an awake spine program: Protocol and illustrative cases

Surgical techniques and technology are steadily improving, thereby expanding the pool of patients amenable for spine surgery. The growing and aging population in the United States further contributes to the increase in spine surgery cases. Traditionally, spine surgery is performed under general anesthesia. However, awake spinal surgery has recently gained traction due to evidence of decreased perioperative risks, postoperative opioid consumption, and costs, specifically in lumbar spine procedures. Despite the potential for improving outcomes, awake spine surgery has received resistance and has yet to become adopted at many healthcare systems. We aim to provide the fundamental steps in facilitating the initiation of awake spine surgery programs. We also present case reports of two patients who underwent awake spine surgery and reported improved clinical outcomes.

•

Starting an Awake Spine program is feasible and may improve clinical outcomes.

•

Awake Spine Surgery is associated with reduced cardiopulmonary complications and opioid consumption.

•

Awake Spine Surgery is effective at reducing LOS, HAC, and cost of surgery.

•

Awake Spine Surgery increases the pool of patients eligible for spinal procedures.

Augmented Reality Neuronavigation for En Bloc Resection of Spinal Column Lesions

BACKGROUND

Primary tumors involving the spine are relatively rare but represent surgically challenging procedures with high patient morbidity. En bloc resection of these tumors necessitates large exposures, wide tumor margins, and poses risks to functionally relevant anatomical structures. Augmented reality neuronavigation (ARNV) represents a paradigm shift in neuronavigation, allowing on-demand visualization of 3D navigation data in real-time directly in line with the operative field.

METHODS

Here, we describe the first application of ARNV to perform distal sacrococcygectomies for the en bloc removal of sacral and retrorectal lesions involving the coccyx in 2 patients, as well as a thoracic 9-11 laminectomy with costotransversectomy for en bloc removal of a schwannoma in a third patient.

RESULTS

In our experience, ARNV allowed our teams to minimize the length of the incision, reduce the extent of bony resection, and enhanced visualization of critical adjacent anatomy. All tumors were resected en bloc, and the patients recovered well postoperatively, with no known complications. Pathologic analysis confirmed the en bloc removal of these lesions with negative margins.

CONCLUSIONS

We conclude that ARNV is an effective strategy for the precise, en bloc removal of spinal lesions including both sacrococcygeal tumors involving the retrorectal space and thoracic schwannomas.

Use of Spinal Anesthesia in Lower Thoracic Spine Surgery: A Case Series

BACKGROUND

Spinal anesthesia is a safe and effective alternative to general anesthesia for patients undergoing lumbar spine surgery, and numerous reports have demonstrated its advantages. To the best of our knowledge, no group has specifically reported on the use of spinal anesthesia in thoracic-level spine surgeries because there is a hypothetical risk of injuring the conus medullaris at these levels. With the advantages of spinal anesthesia and the desire for many elderly patients to avoid general anesthesia, our group has uniquely explored the use of this modality on select patients with thoracic pathology requiring surgical intervention.

OBJECTIVE

To investigate the feasibility of performing thoracic-level spinal surgeries under spinal anesthesia and report our experience with 3 patients.

METHODS

A retrospective chart review of medical records was undertaken, involving clinical notes, operative notes, and anesthesia records.

RESULTS

Three spinal stenosis patients underwent thoracic laminectomy under spinal anesthesia. Two surgeries were performed at the T11-T12 level and 1 at the T12-L1 level. The average age was 82 years, average American Society of Anesthesiologists score was 3.3, and 1 identified as female. Two cases used hyperbaric 0.75% bupivacaine dissolved in dextrose, and 1 used isobaric 0.5% bupivacaine dissolved in water.

CONCLUSION

Spinal anesthesia is feasible for thoracic-level spine procedures, even in elderly patients with comorbidities. We describe our cases and technique for safely achieving a thoracic level of analgesia, as well as discuss recommendations, adverse events, and considerations for the use of spinal anesthesia during lower thoracic-level spine operations.