Awake, Endoscopic Revision Surgery for Lumbar Pseudarthrosis After Transforaminal Lumbar Interbody Fusion: Technical Notes

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.

Revisional Endoscopic Foraminal Decompression via Modified Interlaminar Approach at L5-S1 after Failed Posterior Instrumented Lumbar Fusion in Elderly Patients

Elderly people usually have poorer surgical tolerance and a higher incidence of complications when undergoing revision surgery after posterior instrumented lumbar fusion (PILF). Full-endoscopic transforaminal surgery is a safe and effective option, but sometimes, it is difficult to revise L5-S1 foraminal stenosis (FS) after PILF. Therefore, we developed full-endoscopic lumbar decompression (FELD) at the arthrodesis level via a modified interlaminar approach under local anesthesia. This study aimed to describe the technical note and clinical efficacy of the technique. Eleven patients with unilateral lower limb radiculopathy after PILF underwent selective nerve root block and then underwent FELD. Magnetic resonance imaging (MRI) and computer tomography (CT) were performed on the second postoperative day. Their clinical outcomes were evaluated with a Visual analog scale (VAS) of low back pain and sciatica pain, Oswestry disability index (ODI), and the MacNab score. Complete decompression was achieved in every case with FELD without serious complications. Postoperative VAS of sciatica pain and ODI at each time point and VAS of low back pain and ODI after three months postoperatively were significantly improved compared with those preoperative (p < 0.05). According to the MacNab criteria, seven patients (63.6%) had excellent results at the two-year follow-up, and four patients (36.4%) had good results. No patients required further revision surgery. FELD, via a modified interlaminar approach, is effective for treating unilateral L5-S1 FS after PILF in elderly people.

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.

Advancing Education in Endoscopic Spinal Navigation: Novel Methods and Technical Note

This report aims to demonstrate how to teach anatomy and understanding of spinal endoscopic vision and navigation using mnemonics. The authors present a new surgical technique for teaching endoscopic spinal navigation in a didactic manner with tips such as the "rule of the hand" and decomposition of the endoscopic navigation movement. We demonstrate how the surgery is seen and illustrate how images are projected onto the screen, then divide the navigation into spatial orientation and self-navigation. The article describes the proper puncture technique, how to introduce the working portal, and how to assimilate this new anatomical vision using the "rule of the hand." The surgeon projects their hand on the video screen to guide themselves when starting the navigation and uses the same technique to localize regions of interest during surgery. Finally, the authors break down the navigational movement into three components: forceps positioning, triangulation, and joystick motion. One of the biggest challenges when learning spinal endoscopic surgery is understanding the anatomy seen through the endoscope. By decomposing movements required for navigation, one can understand how to make proper use of the equipment as well as improve their knowledge of this "new anatomy." The learning methods taught in this article have the potential to decrease the learning curve and radiation exposure to those that are still acquainting themselves to spinal endoscopic navigation. We recommend that further studies measure and quantify the impact of these methods on surgical practice.

Innovations in Spinal Endoscopy

Innovations in spinal endoscopy technology and technique have broadened their applications during the past 10 years. Smaller outer-diameter working-channel endoscopes have permitted safe usage in the cervical spine for full endoscopic decompressions. Endoscopic fusions have now been widely reported, leveraging compatible instrumentation for disc preparation and expandable interbody grafts. This ultra-minimally invasive technique has also enabled the performance of fusion procedures in awake patients under monitored anesthesia care, affording speedier recovery and treatment options for those unable to undergo general anesthesia. Revision surgery after open or minimally invasive posterior discectomy or instrumentation can now be performed with endoscopic techniques, which often leverage the transforaminal approach to avoid scar tissue and adhesions. These procedures, among other endoscopic surgeries, are now being increasingly performed in ambulatory surgery centers, as safe outcomes, economic benefits to the healthcare system, and patients' desire to recover at home are becoming more apparent. Finally, the standardization of endoscopic terminology, which has long been a confounder to proper communication and education in this field, has recently been addressed by leading experts in a consensus document, which will serve as the foundation for future collaborative advancements.

Endoscopic Techniques for Lumbar Interbody Fusion: Principles and Context

Endoscopic techniques in spine surgery are rapidly evolving, with operations becoming progressively safer and less invasive. Lumbar interbody fusion (LIF) procedures comprise many spine procedures that have benefited from endoscopic assistance and minimally invasive approaches. Though considerable variation exists within endoscopic LIF, similar principles and techniques are common to all types. Nonetheless, innovations continually emerge, requiring trainees and experienced surgeons to maintain familiarity with the domain and its possibilities. We present two illustrative cases of endoscopic transforaminal lumbar interbody fusion with a comprehensive literature review of the different approaches to endoscopic LIF procedures.

Regional Anesthesia for Lumbar Spine Surgery: Can It Be a Standard in the Future?

This paper is an overview of various features of regional anesthesia (RA) and aims to introduce spine surgeons unfamiliar with RA. RA is commonly used for procedures that involve the lower extremities, perineum, pelvic girdle, or lower abdomen. However, general anesthesia (GA) is preferred and most commonly used for lumbar spine surgery. Spinal anesthesia (SA) and epidural anesthesia (EA) are the most commonly used RA methods, and a combined method of SA and EA (CSE). Compared to GA, RA offers numerous benefits including reduced intraoperative blood loss, arterial and venous thrombosis, pulmonary embolism, perioperative cardiac ischemic incidents, renal failure, hypoxic episodes in the postanesthetic care unit, postoperative morbidity and mortality, and decreased incidence of cognitive dysfunction. In spine surgery, RA is associated with lower pain scores, postoperative nausea and vomiting, positioning injuries, shorter anesthesia time, and higher patient satisfaction. Currently, RA is mostly used in short lumbar spine surgeries. However, recent findings illustrate the possibility of applying RA in spinal tumors and spinal fusion. Various researches reveal that SA is an effective alternative to GA with lower minor complications incidence. Comprehensive insight on RA will promote spine surgery under RA, thereby broadening the horizon of spine surgery under RA.

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

OBJECTIVE

There is a learning curve for surgeons performing "awake" spinal surgery. No comprehensive guidelines have been proposed for the selection of ideal candidates for awake spinal fusion or decompression. The authors sought to formulate an algorithm to aid in patient selection for surgeons who are in the startup phase of awake spinal surgery.

METHODS

The authors developed an algorithm for selecting patients appropriate for awake spinal fusion or decompression using spinal anesthesia supplemented with mild sedation and local analgesia. The anesthetic protocol that was used has previously been reported in the literature. This algorithm was formulated based on a multidisciplinary team meeting and used in the first 15 patients who underwent awake lumbar surgery at a single institution.

RESULTS

A total of 15 patients who underwent decompression or lumbar fusion using the awake protocol were reviewed. The mean patient age was 61 ± 12 years, with a median BMI of 25.3 (IQR 2.7) and a mean Charlson Comorbidity Index of 2.1 ± 1.7; 7 patients (47%) were female. Key patient inclusion criteria were no history of anxiety, 1 to 2 levels of lumbar pathology, moderate stenosis and/or grade I spondylolisthesis, and no prior lumbar surgery at the level where the needle is introduced for anesthesia. Key exclusion criteria included severe and critical central canal stenosis or patients who did not meet the inclusion criteria. Using the novel algorithm, 14 patients (93%) successfully underwent awake spinal surgery without conversion to general anesthesia. One patient (7%) was converted to general anesthesia due to insufficient analgesia from spinal anesthesia. Overall, 93% (n = 14) of the patients were assessed as American Society of Anesthesiologists class II, with 1 patient (7%) as class III. The mean operative time was 115 minutes (± 60 minutes) with a mean estimated blood loss of 46 ± 39 mL. The median hospital length of stay was 1.3 days (IQR 0.1 days). No patients developed postoperative complications and only 1 patient (7%) required reoperation. The mean Oswestry Disability Index score decreased following operative intervention by 5.1 ± 10.8.

CONCLUSIONS

The authors propose an easy-to-use patient selection algorithm with the aim of assisting surgeons with patient selection for awake spinal surgery while considering BMI, patient anxiety, levels of surgery, and the extent of stenosis. The algorithm is specifically intended to assist surgeons who are in the learning curve of their first awake spinal surgery cases.

Transforaminal 360° lumbar endoscopic foraminotomy in postfusion patients: technical note and case series

OBJECTIVE

This report describes a minimally invasive lumbar foraminotomy technique that can be applied in patients who underwent complex spine decompression procedures or in patients with severe foraminal stenosis.

METHODS

Awake, endoscopic decompression surgery was performed in 538 patients over a 5-year period between 2014 and 2019. Transforaminal endoscopic foraminal decompression surgery using a high-speed endoscopic drill was performed in 34 patients who had previously undergone fusions at the treated level.

RESULTS

At 2-year follow-up, the mean (± SD) preoperative visual analog scale score for leg pain and the Oswestry Disability Index improved from 7.1 (± 1.5) and 40.1% (± 12.1%) to 2.1 (± 1.9) and 13.6% (± 11.1%).

CONCLUSIONS

A minimally invasive, awake procedure is presented for the treatment of severe lumbar foraminal stenosis in patients with lumbar radiculopathy after lumbar fusion.

Transforaminal Endoscopic Surgical Treatment for Postlaminectomy Lumbar Radiculopathy: Case Series

OBJECTIVE

To describe outcomes of awake transforaminal endoscopic surgical treatment for patients presenting with lumbar radiculopathy after laminectomy.

METHODS

Awake endoscopic decompression surgery was performed on 538 patients over a 5-year period (2014-2019). Transforaminal endoscopic discectomy and foraminotomy was performed in 128 patients who had previously undergone laminectomy surgery.

RESULTS

At 2-year follow-up, preoperative visual analog scale score for leg pain improved from 7.0 ± 1.4 to 2.0 ± 1.3 and Oswestry Disability Index score improved from 41.4% ± 11.9% to 12.4% ± 11.9% in 118 patients. During the 2-year follow-up period, 10 patients (7.8%) required repeat surgery at the treated level.

CONCLUSIONS

The results of a minimally invasive awake endoscopic procedure are presented for the treatment of lumbar radiculopathy after lumbar laminectomy in a series of patients.

Transforaminal Endoscopic Surgical Treatment for Posterior Migration of Polyetheretherketone Transforaminal Lumbar Interbody Fusion Cage: Case Series

OBJECTIVE

This study aims to report the clinical outcome of treating lumbar radiculopathy in the setting of retropulsed polyetheretherketone (PEEK) transforaminal lumbar interbody fusion (TLIF) cages with transforaminal endoscopic spine surgery.

METHODS

A retrospective study of 8 patients with lumbar radiculopathy in the setting of a retropulsed PEEK TLIF cage were included from January 2014 to January 2019. The inclusion criteria were 1) lumbar radiculopathy in the setting of a retropulsed PEEK TLIF cage causing nerve compression and 2) follow-up at least 1 year. Patients were asked to complete the following questionnaires for outcome evaluation: visual analog scales (VAS) for leg pain and the Oswestry Disability Index (ODI).

RESULTS

Eight patients underwent transforaminal endoscopic surgery for treatment of radiculopathy in the setting of a retropulsed PEEK TLIF cage in the 5-year period evaluated. One year after surgery, the VAS and ODI scores showed a significant decrease: average preoperative VAS and ODI scores were 6.9 ± 1.2 and 50.5 ± 10.9, and 1-year postoperative VAS and ODI scores were 2.3 ± 1.3 and 17.3 ± 5.1.

CONCLUSIONS

Transforaminal endoscopic spine surgery for the treatment of a retropulsed PEEK TLIF cage is a safe and effective approach with low morbidity and acceptable complication rates for patients with radiculopathy secondary to a retropulsed PEEK TLIF cage. Compared with a more invasive approach to removing or drilling the PEEK TLIF cage, endoscopic spine surgery could achieve a similar improvement in the patient-reported outcomes with possibly fewer complications.