Surgeon motivation, and obstacles to the implementation of minimally invasive spinal surgery techniques

Advances and Challenges in Minimally Invasive Spine Surgery

Minimally invasive spine surgery continues to grow and develop. Over the past 50 years, there has been immense growth within this subspecialty of neurosurgery. A deep understanding of the historical context and future directions of this subspecialty is imperative to developing safe adoption and targeted innovation. This review aims to describe the advancements, and challenges that we face today in minimally invasive spine surgery.

Surgeon Perceptions of Performing Transforaminal Lumbar Interbody Fusion in an Ambulatory Surgical Center vs Hospital Setting in the Elderly Population: Results of a Surgeon Survey

BACKGROUND

There is an increasing acceptance of conducting minimally invasive transforaminal lumbar interbody fusion (TLIF) in ambulatory surgical centers (ASCs). The Centers for Medicare and Medicaid Services (CMS) introduced the Hospitals Without Walls (HWW) program in March 2020. This program granted hospitals regulatory flexibility to offer services and procedures in nontraditional locations, including ASCs. However, implementation hurdles persist.

METHODS

A survey was sent to 235 surgeons regarding the use of ASCs for performing TLIF surgeries on elderly patients. Multiple-choice questions covering various aspects of TLIF practice preferences, including surgical indications, decision factors for choosing ASCs over hospitals, implementation hurdles, reimbursement concerns, staffing issues, and the impact of CMS rules and regulations on TLIF in ASCs, particularly concerning physician ownership and self-referral conflicts governed by the Stark law, were asked.

RESULTS

The survey completion rate was 25.8% (Figure 1). The most common surgical indications for TLIF in ASCs were spondylolisthesis (80%), spinal stenosis (62.5%), and low back pain (47.5%). Most surgeons (78%) believed TLIF could be safely performed in ASCs. Streamlined workflow, lower infection rates, and cost-effectiveness were advantages listed by 58.5% of surgeons. Patient's medical history (75.8%), followed by ASC resources and capabilities (61%) and surgeon preference (61%), were relevant factors. Higher efficiencies at ASCs (14.6%), contractual issues (9.8%), and ownership issues (7.3%) were less relevant to surgeons. About 65.9% of surgeons reported lower reimbursement in ASCs, and 43.9% said it was an implementation hurdle. Lower direct costs were reported by 53.7% of surgeons. Other hurdles included a lack of trained staff (24.4%), inadequate staffing (22.0%), cost overruns (26.8%), high Joint Commission or the Accreditation Association for Ambulatory Health Care credentialing costs, and surgeons feeling uncomfortable performing TLIF in ASCs (22.0%). Only 17.1% listed medical problems as a reason their patient was considered unsuitable for the ASC environment. A majority (53.7%) stated that their ASCs complied with strict Stark requirements by disclosing physician ownership interests. However, 22% of surgeons reported self-referrals under the "In-Office Ancillary Services Exception" allowed by the Stark law.

CONCLUSION

Our survey data show that surgeons' perceptions of current CMS rules and regulations may hinder the transition into the ASC setting because they think the reimbursement is too low and the regulatory burden is too high. ASCs have disproportionally higher initial acquisition and ongoing costs related to staff training and maintenance of the TLIF technology that CMS should consider when determining the appropriate financial remuneration for these complex procedures.

CLINICAL RELEVANCE

ASC offers a viable and attractive option for their TLIF procedure with the advantage of same-day discharge and at-home recovery.

LEVEL OF EVIDENCE: 3

Revitalizing neurosurgical frontiers: The EANS frontiers in neurosurgery committee's strategic framework

Introduction

The field of neurosurgery faces challenges with the increasing involvement of other medical specialties in areas traditionally led by neurosurgeons. This paper examines the implications of this development for neurosurgical practice and patient care, with a focus on specialized areas like pain management, peripheral nerve surgery, and stereotactic radiosurgery.

Research question

To assess the implications of the expanded scope of other specialties for neurosurgical practice and to consider the response of the EANS Frontiers in Neurosurgery Committee to these challenges.

Materials and methods

Analysis of recent trends in neurosurgery, including the shift in various procedures to other specialties, demographic challenges, and the emergence of minimally invasive techniques. This analysis draws on relevant literature and the initiatives of the Frontiers in Neurosurgery Committee.

Results

We explore a possible decrease in neurosurgical involvement in certain areas, which may have implications for patient care and access to specialized neurosurgical interventions. The Frontiers in Neurosurgery Committee's role in addressing these concerns is highlighted, particularly in terms of training, education, research, and networking for neurosurgeons, especially those early in their careers.

Discussion and conclusion

The potential decrease in neurosurgical involvement in certain specialties warrants attention. This paper emphasizes the importance of carefully considered responses by neurosurgical societies, such as the EANS, to ensure neurosurgeons continue to play a vital role in managing neurological diseases. Emphasis on ongoing education, integration of minimally invasive techniques, and multidisciplinary collaboration is essential for maintaining the field's competence and quality in patient care.

Visible trephine-based foraminoplasty in PTED leads to asymmetrical stress changes and instability in the surgical and adjacent segments: a finite element analysis

This study aimed to construct a multi-segment lumbar finite element model (FEM) of PTED surgery to analyze the changes in stress and ROM after visible trephine-based foraminoplasty. The CT scans of a 35-year-old healthy male were used to develop a multi-segment lumbar FEM with Mimic, Geomagic Studio, Hypermesh and MSC.Patran. Different foraminoplasty was performed on the model, and these were grouped into normal group (A), the ventral resection group (B), the apex resection group (C), the ventral + apex + isthmus resection group (D), and the SAP + isthmus + lateral recess resection group (E). A vertical load of 500N and a torque of 10N·M were applied to the upper surface of the L3 vertebral body to simulate the biomechanical characteristics under the motion of flexion, extension, lateral bending, and rotation. The von Mises stress maps of the intervertebral f, vertebral body, facet joints, and the ROM of the L3-S1 intervertebral disk were calculated and analyzed. The changes of peak stress on the vertebral body for each group were not significant in the same motion state. Significant stress differences were observed in the L4/5 intervertebral disks, while no obvious stress changes were observed for the L3/4 and L5/S1 intervertebral disks. The stress of the L3/4 and L5/S1 facet joints decreased after L4/5 foraminoplasty, while the stress of L4/5 facet joints displayed an overall increasing trend. Significant asymmetrical stress changes of bilateral facet joints were observed in all three segments, particularly during bilateral rotation movements. The ROM of L3-S1 gradually increased from Group A to Group E, especially during flexion, left lateral bending, and right rotation, with the highest elevation observed for the L45 ROM. Our FEM indicated that enlarged resection and exposure of the articular surface could lead to significant asymmetrical stress changes in the bilateral facet joints and ROM instability of the surgical and adjacent segments. These findings suggested that unnecessary and excessive resection should be avoided in PTED to reduce the incidence of low back pain and the risk of postsurgical degeneration.

Determination of Work Related to Endoscopic Decompression of Lumbar Spinal Stenosis

Background: Effective 1 January 2017, single-level endoscopic lumbar discectomy received a Category I Current Procedural Terminology (CPT®) code 62380. However, no work relative value units (wRVUs) are currently assigned to the procedure. A physician’s payment needs to be updated to commensurate with the work involved in the modern version of the lumbar endoscopic decompression procedure with and without the use of any implants to stabilize the spine. In the United States, the American Medical Association (AMA) and its Specialty Society Relative Value Scale Update Committee (RUC) proposes to the Centers for Medicare and Medicaid Services (CMS) what wRVUs to assign for any endoscopic lumbar surgery codes. Methods: The authors conducted an independent survey between May and June 2022 which reached 210 spine surgeons using the TypeForm survey platform. The survey link was sent to them via email and social media. Surgeons were asked to assess the endoscopic procedure’s technical and physical effort, risk, and overall intensity without focusing just on the time required to perform the surgery. Respondents were asked to compare the work involved in modern comprehensive endoscopic spine care with other commonly performed lumbar surgeries. For this purpose, respondents were provided with the verbatim descriptions of 12 other existing comparator CPT® codes and associated wRVUs of common spine surgeries, as well as a typical patient vignette describing an endoscopic lumbar decompression surgery scenario. Respondents were then asked to select the comparator CPT® code most reflective of the technical and physical effort, risk, intensity, and time spent on patient care during the pre-operative, peri- and intra-operative, and post-operative periods of a lumbar endoscopic surgery. Results: Of the 30 spine surgeons who completed the survey, 85.8%, 46.6%, and 14.3% valued the appropriate wRVU for the lumbar endoscopic decompression to be over 13, over 15, and over 20, respectively. Most surgeons (78.5%; <50th percentile) did not think they were adequately compensated. Regarding facility reimbursement, 77.3% of surgeons reported that their healthcare facility struggled to cover the cost with the received compensation. The majority (46.5%) said their facility received less than USD 2000, while another 10.7% reported less than USD 1500 and 17.9% reported less than USD 1000. The professional fee received by surgeons was <USD 1000 for 21.4%, <USD 2000 for 17.9%, and <USD 1500 for 10.7%, resulting in a fee less than USD 2000 for 50% of responding surgeons. Most responding surgeons (92.6%) recommended an endoscopic instrumentation carveout to pay for the added cost of the innovation. Discussion and Conclusions: The survey results indicate that most surgeons associate CPT® 62380 with the complexity and intensity of a laminectomy and interbody fusion preparation, considering the work in the epidural space using the contemporary outside-in and interlaminar technique and the work inside the interspace using the inside-out technique. Modern endoscopic spine surgery goes beyond the scope of a simple soft-tissue discectomy. The current iterations of the procedure must be considered to avoid undervaluing its complexity and intensity. Additional undervalued payment scenarios could be created if technological advances continue to replace traditional lumbar spinal fusion protocols with less burdensome, yet no less complex, endoscopic surgeries that necessitate a high surgeon effort in terms of time required to perform the operation and its intensity. These undervalued payment scenarios of physician practices, as well as the facility and malpractice expenses, should be further discussed to arrive at updated CPT® codes reflective of modern comprehensive endoscopic spine care.

Clinical Consequences of Incidental Durotomy during Full-Endoscopic Lumbar Decompression Surgery in Relation to Intraoperative Epidural Pressure Measurements

Background: Seizures, neurological deficits, bradycardia, and, in the worst cases, cardiac arrest may occur following incidental durotomy during routine lumbar endoscopy. Therefore, we set out to measure the intraoperative epidural pressure during lumbar endoscopic decompression surgery. Methods: We conducted a retrospective observational cohort study to obtain intraoperative epidural measurements with an epidural catheter-pressure transducer assembly through the spinal endoscope on 15 patients who underwent lumbar endoscopic decompression of symptomatic lumbar herniated discs and spinal stenosis. The endoscopic interlaminar technique was employed. Results: There were six (40.0%) female and nine (60.0%) male patients aged 49.0667 ± 11.31034, ranging from 36 to 72 years, with an average follow-up of 35.15 ± 12.48 months. Three of the fifteen patients had seizures with durotomy and one of these three had intracranial air on their postoperative brain CT. Another patient developed spinal headaches and diplopia on postoperative day one when her deteriorating neurological function was investigated with a brain computed tomography (CT) scan, showing an intraventricular hemorrhage consistent with a Fisher Grade IV subarachnoid hemorrhage. A CT angiogram did not show any abnormalities. Pressure recordings in the epidural space in nine patients ranged from 20 to 29 mm Hg with a mean of 24.33 mm Hg. Conclusion: Most incidental durotomies encountered during lumbar interlaminar endoscopy can be managed without formal repair and supportive care measures. The intradural spread of irrigation fluid and intraoperatively used drugs and air entrapment through an unrecognized durotomy should be suspected if patients deteriorate in the recovery room. Ascending paralysis may cause nausea, vomiting, upper and lower motor neuron symptoms, cranial nerve palsies, hypotension, bradycardia, and respiratory and cardiac arrest. The recovery team should be prepared to manage these complications.

Identification of the Magna Radicular Artery Entry Foramen and Adamkiewicz System: Patient Selection for Open versus Full-Endoscopic Thoracic Spinal Decompression Surgery

BACKGROUND

Casually cauterizing the radicular magna during routine thoracic discectomy may have dire consequences.

METHODS

We performed a retrospective observational cohort study on patients scheduled for decompression of symptomatic thoracic herniated discs and spinal stenosis who underwent a preoperative computed tomography angiography (CTA) to assess the surgical risks by anatomically defining the foraminal entry level of the magna radicularis artery into the thoracic spinal cord and its relationship to the surgical level.

RESULTS

Fifteen patients aged 58.53 ± 19.57, ranging from 31 to 89 years, with an average follow-up of 30.13 ± 13.42 months, were enrolled in this observational cohort study. The mean preoperative VAS for axial back pain was VAS of 8.53 ± 2.06 and reduced to a postoperative VAS of 1.60 ± 0.92 (p < 0.0001) at the final follow-up. The Adamkiewicz was most frequently found at T10/11 (15.4%), T11/12 (23.1%), and T9/10 (30.8%). There were eight patients where the painful pathology was found far from the AKA foraminal entry-level (type 1), three patients with near location (type 2), and another four patients needing decompression at the foraminal (type 3) entry-level. In five of the fifteen patients, the magna radicularis entered the spinal canal on the ventral surface of the exiting nerve root through the neuroforamen at the surgical level requiring a change of surgical strategy to prevent injury to this important contributor to the spinal cord's blood supply.

CONCLUSIONS

The authors recommend stratifying patients according to the proximity of the magna radicularis artery to the compressive pathology with CTA to assess the surgical risk with targeted thoracic discectomy methods.

USE OF THE uCentrum SYSTEM IN THE SURGICAL TREATMENT OF DISEASES OF THE VERTEBRAL SPINE

ABSTRACT Objectives: Evaluate the treatment outcome and the performance of the uCentum spinal fixation system in treating traumatic, degenerative, and tumoral diseases of the spine. Methods: This is a therapeutic study to investigate treatment outcomes and level of evidence III, including twenty-three adult patients of both sexes undergoing surgical treatment of degenerative (13 patients), traumatic (04 patients), or tumor diseases (06 patients). Patients were prospectively evaluated using clinical parameters: pain (visual analog scale), clinical and functional assessment questionnaires (SF-36, Oswestry and Roland-Morris), and radiological criteria (arthrodesis consolidation, loosening, breakage or deformation of the implants). Results: Twenty patients were followed for a period of 01 month to 12 month (mean 6,5±7,77). Three patients died due to complications unrelated to the primary disease (traumatic brain injury, septicemia, and lung tumor). Improvements were observed in clinical parameters and scores of the evaluation questionnaires used. No implant-related complications (breakage, loosening, deformation) were observed. Conclusion: the uCentum fixation system showed great versatility for performing the surgical treatment, allowing the performance of open, percutaneous procedures, the introduction of acrylic cement inside the implants, and conversion of polyaxial screws into monoaxial screws intraoperatively. Level of Evidence III; Therapeutic Studies - Investigating the Results of Treatment.

Dural Tears During Lumbar Spinal Endoscopy: Surgeon Skill, Training, Incidence, Risk Factors, and Management

BACKGROUND

Incidental dural tears during lumbar endoscopy can be challenging to manage. There is limited literature on their appropriate management, risk factors, and the clinical consequences of this typically uncommon complication.

MATERIALS AND METHODS

To improve the statistical power of studying durotomy with lumbar endoscopy, we performed a retrospective survey study among endoscopic spine surgeons by email and chat groups on social media networks, including WhatsApp and WeChat. Descriptive and correlative statistics were done on the surgeons' recorded responses to multiple-choice questions. Surgeons were asked about their clinical experience with spinal endoscopy, training background, the types of lumbar endoscopic decompression they perform by approach, the decompression instruments they use, and incidental durotomy incidence with routine lumbar endoscopy.

RESULTS

There were 689 dural tears in 64 470 lumbar endoscopies, resulting in an incidental durotomy incidence of 1.07%. Seventy percent of the durotomies were reported by 20.4% of the surgeons. Eliminating these 19 outlier surgeons yielded an adjusted durotomy rate of 0.32. Endoscopic stenosis decompression (54.8%; P < .0001), rather than endoscopic discectomy (44.1%; 41/93), was significantly more associated with durotomy. Medium-sized dural tears (1-10 mm) were the most common (52.2%; 48/93). Small pinhole durotomies (less than 1 mm) were the second most common type (46.7%; 43/93). Rootlet herniations were seen by 46.2% (43/93) of responding surgeons. The posterior dural sac injury during the interlaminar approach (57%; 53/93) occurred more frequently than traversing nerve-root injuries (31.2%) or anterior dural sac (23.7%; 22/93). Exiting nerve-root injuries (10.8%;10/93) were less common. Over half of surgeons did not attempt any repair or closure (52.2%; 47/90). Forty percent (36/90) used sealants. Only 7.8% (7/90) of surgeons attempted an endoscopic repair or sutures (11.1%; 10/90). DuralSeal was the most commonly used brand of commercially available sealant used (42.7%; 35/82). However, other sealants such as Tisseal (15.9%; 13/82), Evicel (2.4%2/82), and additional no-brand sealants (38; 32/82) were also used. Nearly half of the patients (48.3%; 43/89) were treated with 24-48 hours of bed rest. The majority of participating surgeons (64%; 57/89) reported that the long-term outcome was unaffected. Only 18% of surgeons reported having seen the development of a postoperative cerebrospinal fluid (CSF)-fistula (18%;16/89). However, the absolute incidence of CSF fistula was only 0.025% (16/64 470). Severe radiculopathy with dysesthesia; sensory loss; and motor weakness in association with an incidental durotomy were reported by 12.4% (11/89), 3.4% (3/89), and 2.2% (2/89) of surgeons, respectively.

CONCLUSIONS

The incidence of dural tears with lumbar endoscopy is about 1%. The incidence of durotomy is higher with the use of power drills and the interlaminar approach. Stenosis decompression that typically requires the more aggressive use of these power instruments has a slightly higher incidence of dural tears than does endoscopic decompression for a herniated disc. Most dural tears are small and can be successfully managed with mechanical compression with Gelfoam and sealants. Two-thirds of patients with incidental dural tears had an entirely uneventful postoperative course. The remaining one-third of patients may develop a persistent CSF leak, radiculopathy with dysesthesia, sensory loss, or motor function loss. Patients should be educated preoperatively and reassured.

LEVEL OF EVIDENCE

3.

Lumbar Endoscopic Bony and Soft Tissue Decompression With the Hybridized Inside-Out Approach: A Review And Technical Note

This study aimed to showcase the authors' preferred technique of a hybrid of modern "inside-out" and "outside-in" endoscopic decompression. A case series of 411 patients consisting of 192 females (46.7%) and 219 males (53.3%) with an average age of 54.84 ± 16.32 years and an average of 43.2 ± 26.53 months are presented. Patients underwent surgery for low-grade spondylolisthesis (13 of 411, 3.2%), herniated disc (135 of 411, 32.8%), foraminal spinal stenosis (101 of 411, 24.6%), or a combination of the latter 2 conditions (162 of 411, 39.4%). The preoperative Oswestry Disability Index (ODI) and visual analogue scale (VAS) for leg pain were 49.8 ± 17.65 and 7.9 ± 1.55, respectively. Postoperative ODI and VAS leg were 12.2 ± 9.34 and 2.41 ± 5 1.55 at final follow-up (p < 0.0001). MacNab outcomes were excellent in 134 (32.6%), good in 228 (55.5%), fair in 40 (9.7%), and poor in 9 patients (2.2%), respectively. There was end-stage degenerative vacuum disc disease in 304 of the 411 patients (74%) of which had 37.5% had excellent and 50% good MacNab outcomes. Patients without vacuum discs had excellent and good 18.7% and 71.0% of the time. Direct visualization of pain generators in the epidural- and intradiscal space is the authors' preferred transforaminal decompression technique and is supported by their reliable clinical outcomes.

Dysethesia due to irritation of the dorsal root ganglion following lumbar transforaminal endoscopy: Analysis of frequency and contributing factors

BACKGROUND

New onset of acute dysethetic leg pain due to irritation of the dorsal root ganglion (DRG) following uneventful recovery from an expertly executed lumbar transforaminal endoscopic decompression is a common problem. Its incidence and relation to any risk factors that could be mitigated preoperatively are not well understood.

METHODS

We performed a multicenter frequency analysis of DRG irritation dysesthesia in 451 patients who underwent lumbar transforaminal endoscopic decompression for herniated disc and foraminal stenosis. The 451 patients consisted of 250 men and 201 women with an average age of 55.77 ± 15.6 years. The average follow-up of 47.16 months. The primary clinical outcome measures were the modified Macnab criteria. Chi-square testing was employed to analyze statistically significant associations between increased dysesthesia rates, preoperative diagnosis, the surgical level(s), and surgeon technique.

RESULTS

At final follow-up, Excellent (183/451; 40.6 %) and Good (195/451; 43.2 %) Macnab outcomes were observed in the majority of patients (378/451; 83.8 %). The majority of study patients (354; 78.5 %) had an entirely uneventful postoperative recovery without any DRG irritation, but 21.5 % of patients were treated for it in the immediate postoperative recovery period with supportive care measures including activity modification, transforaminal epidural steroid injections, non-steroidal anti-inflammatories, gabapentin, or pregabalin. There was no statistically significant difference in dysesthesia rates between lumbar levels from L1 to S1, or between single (DRG rate 21.8 %) or two-level (DRG rate 20.2 %) endoscopic decompression (p = 0.742). A statistically significantly higher incidence of postoperative dysesthesia was observed in patients who underwent decompression for foraminal stenosis (38/103; 27 %), and recurrent herniated disc (7/10; 41.2 %; p = 0.039). There were also statistically significant variations in dysesthesia rates between the seven participating clinical study sites ranging from 11.6%-33% (p = 0.002). Unrelenting postoperative dysesthetic leg pain due to DRG irritation was statistically associated with less favorable long-term clinical outcomes with DRG rates as high as 45 % in patients with a Fair and 61.3 % in patients with Poor Macnab outcomes (p < 0.0001).

CONCLUSIONS

Postoperative dysesthesia following transforaminal endoscopic decompression should be expected in one-fifth of patients. There was no predilection for any lumbar level. Foraminal stenosis and recurrent herniated disc surgery are risk factors for higher dysesthesia rates. There was a statistically significant variation of dysesthesia rates between participating centers suggesting that the surgeon skill level is of significance. Severe postoperative dysesthesia may be a predictor of Fair of Poor long-term Macnab outcomes.