Address for correspondence : Jason K. Lim Department of Neurological Surgery, Georgetown University School of Medicine, 3900 Reservoir Rd NW, Washington, DC 20007, USA Tel : +1-202-687-0100, Fax : +1-202-687-7660, E-mail : jkl97@georgetown.edu

Received 2024 December 17; Revised 2025 March 20; Accepted 2025 June 6.

Abstract

Objective

Posterior endoscopic cervical foraminotomy (PECF) is a minimally invasive surgical technique for treating cervical radiculopathy. Traditionally, PECF is performed under general anesthesia in the prone position, but concerns over anesthesia-related complications have led to the exploration of local anesthesia in the lateral decubitus position as an alternative. This study aims to compare the clinical outcomes, safety, and efficacy of PECF performed under local anesthesia in the lateral decubitus position versus general anesthesia in the prone position.

Methods

We conducted a retrospective analysis of 13 patients who underwent PECF under local anesthesia in the lateral decubitus position. The outcomes were compared with data from 357 patients across eight studies who underwent PECF under general anesthesia in the prone position. Outcomes measures included Visual analog scale (VAS) pain scores, Oswestry disability index (ODI), length of stay (LOS), minimally clinically important difference (MCID), and complications.

Results

Patients in the local anesthesia group demonstrated significant reductions in neck pain (VAS-N : 4.93±1.32 to 1.49±0.52, p<0.001) and arm pain (VAS-A : 8.69±0.75 to 1.85±1.46, p<0.001), achieving a mean pain reduction of 78.8%. These improvements were comparable to the general anesthesia group (VAS-N : 4.80 to 1.28; VAS-A : 6.71 to 1.23). Functional outcomes improved significantly in both groups, with ODI scores improving from 54.76% to 9.82% locally and from 39.92% to 9.62% in the general group. Although LOS was slightly longer for the local anesthesia group (5.85±3.20 vs. 4.81±2.17 days, p=0.18), post-procedure monitoring time was significantly shorter (3.2 vs. 7.4 hours, p<0.001). The local anesthesia group reported zero complications (0%; 95% confidence interval [CI], 0–22.8%) compared to an 8.68% complication rate (95% CI, 5.8–11.6%) in the general anesthesia cohort (p=0.612).

Conclusion

PECF under local anesthesia in the lateral decubitus position provides comparably effective pain relief and functional improvement comparable to general anesthesia, though the difference in complication rates was not statistically significant and requires larger studies for confirmation. This technique may be particularly advantageous for patients at higher risk for anesthesia-related complications. Further research is warranted to validate these findings in larger, prospective studies.

Keywords: Spinal decompression; Endoscopy; Local anesthesia; General anesthesia; Cervical radiculopathy; Minimally invasive surgical procedures

INTRODUCTION

Cervical radiculopathy, often caused by foraminal stenosis or disc herniation, is a common condition resulting in pain and possible neurologic deficits [1]. Traditional open surgical techniques for treating this condition, such as anterior cervical discectomy and fusion or open posterior cervical foraminotomy, involve significant tissue disruption and longer recovery times, especially with posterior approaches [2,3].

The advent of minimally invasive spine surgery techniques, particularly posterior endoscopic cervical foraminotomy (PECF), has advanced the treatment of cervical radiculopathy. PECF allows for effective decompression of cervical nerve roots while minimizing muscle trauma and preserving spinal stability [4-6,18,25]. Studies have shown that PECF offers comparable outcomes to traditional open procedures with the added benefit of reduced postoperative pain, shorter hospital stays, and faster return to daily activities [7,8].

Traditionally, PECF has been performed under general anesthesia with the patient in the prone position. However, general anesthesia poses several risks, especially for elderly patients and those with significant comorbidities. Anesthesia-related complications can include cardiopulmonary events, difficulties associated with the prone positioning such as pressure injuries or vision loss due to raised intraocular pressure, and longer recovery from systemic anesthetic effects. In an effort to mitigate these risks, there is growing interest in performing spinal surgeries under local or regional anesthesia with the patient awake or mildly sedated [6,9,10]. Our group recently introduced an alternative approach using local anesthesia with conscious sedation with the patient in the lateral decubitus position for PECF, showing promising results in terms of feasibility and safety [11]. The lateral decubitus position may offer several advantages over the prone position for patients with comorbidities, including easier airway access, reduced anesthetic risks, and minimized risk of pressure-related complications [12]. Local anesthesia also has several advantages, including reduced perioperative risks, better intraoperative monitoring, and improved postoperative pain control [13-16].

Given these considerations, we aimed to compare the clinical outcomes of PECF performed under local anesthesia with conscious sedation (lateral position) versus general anesthesia (prone position). In this study, we retrospectively analyzed our series of patients who underwent PECF under local anesthesia with conscious sedation and compared their outcomes to those reported in the literature for PECF under general anesthesia. We hypothesized that the awake local anesthesia technique would have comparable efficacy in pain and disability outcomes to the standard general anesthesia technique, with a potential reduction in complication rates and similar hospital stay. By examining factors like pain relief, functional improvement, hospital stay, and complications in each group, we seek to determine whether local anesthesia offers a true clinical benefit and to identify any trade-offs (such as longer operative time or hospital stay) associated with the technique. This comparative analysis, although retrospective, can provide early insights and help guide patient selection and planning for future larger studies on anesthesia choice in endoscopic cervical spine surgery.

MATERIALS AND METHODS

The IRB determined that the proposed activity is not research involving human subjectsas defined by DHHS and FDA regulations. IRB review and approval by this institution is not required.

Study design and patient selection

We performed a retrospective comparative study. The local anesthesia with conscious sedation (termed interchangeably as local anesthesia cohort) group consisted of patients who underwent PECF under local anesthesia with conscious sedation between 2018 and 2023, performed by the senior author (B.C.R.) at a single institution. These were consecutive cases in which the senior author elected to use the awake technique based on patient factors. Inclusion criteria for this group were : age ≥18 years, diagnosis of single-level cervical radiculopathy (from foraminal stenosis or lateral disc herniation) corresponding to clinical symptoms, failure of conservative management (such as physical therapy, medications, or injections), and patient ability to tolerate awake surgery. We excluded any cases that involved additional concurrent procedures (e.g., multi-level decompressions or instrumented fusion) and any cases with inadequate follow-up data. Patients with central stenosis or myelopathy were not included, as those typically require different surgical strategies.

Importantly, for the local anesthesia with conscious sedation approach, there were specific selection considerations. Patients who had significant medical comorbidities (such as severe cardiopulmonary conditions) or other risk factors that made general anesthesia high risk were preferentially offered the option of surgery under local anesthesia. Additionally, patients who expressed a strong desire to avoid general anesthesia (due to personal preference or prior adverse reactions to general anesthesia) were considered for the awake technique. All patients in the local anesthesia cohort were thoroughly counseled about the need to remain still and communicate during the procedure. Patients with extreme anxiety, inability to cooperate when awake, or those on high-dose analgesics/sedatives preoperatively that could interfere with intraoperative cooperation were not chosen for the local anesthesia technique.

For the general anesthesia group, we utilized published data from a literature review rather than a prospective cohort from our institution. We performed a literature search (details below) and identified eight studies (with a total of 357 patients) that reported outcomes of PECF under general anesthesia in the prone position. These studies met similar inclusion criteria (adult patients with cervical radiculopathy treated with PECF) and reported at least one of our outcome measures of interest. We extracted the aggregate data from these studies to form a composite general anesthesia cohort for comparison. Because the general anesthesia data are drawn from multiple sources, there is inherent heterogeneity in this group’s patient population (different surgeons, slightly different techniques or followup durations across studies). However, all selected studies dealt with endoscopic posterior foraminotomy in the cervical spine for radiculopathy, making them appropriate for comparison. We did not include data from any anterior cervical endoscopic techniques or open surgeries – the comparison is focused on the posterior endoscopic approach under two anesthesia conditions. This approach was chosen due to the ethical and practical challenges of assembling a large prospective control group.

Anesthetic approach for local anesthesia with conscious sedation

For the local anesthesia group with conscious sedation, patients were positioned in the lateral decubitus position, with the affected side (radiculopathy side) upwards. Careful padding of pressure points and neutral cervical alignment, adjusted fluoroscopically, was ensured to optimize surgical access and patient comfort. Sedation was administered using monitored anesthesia care, typically involving intravenous midazolam and propofol titrated for mild sedation, combined with intermittent administration of pethidine and fentanyl as required for analgesia. All patients remained spontaneously breathing without airway intubation. Local anesthesia with conscious sedation was applied incrementally through a step-wise approach : 1) initial subcutaneous injection of lidocaine (1%) at the incision site; 2) fluoroscopy-guided deep injection of bupivacaine (0.5%) targeting the periosteal surface of the lamina and facet joint; and 3) epidural injection of bupivacaine (0.5%) delivered intraoperatively via the foramen to anesthetize the nerve root adequately.

Following anesthesia, an approximately 8-mm skin incision was made posteriorly over the target cervical level. Using a sequential dilation technique, a working cannula (about 7 mm diameter) was placed at the cervical lamina-facet junction under fluoroscopic guidance. An endoscope with a working channel was inserted, and under constant saline irrigation, targeted partial laminotomy and medial facetectomy (foraminotomy) were performed using high-speed burrs and trephines. After adequate bony decompression, the ligamentum flavum was resected, clearly visualizing and decompressing the nerve root and dural sac. Any compressive foraminal disc fragments or osteophytes were endoscopically removed. During these maneuvers, patient responsiveness was continuously monitored, allowing real-time feedback to ensure nerve safety and complete decompression. Surgical technique and anesthesia protocol were consistent with methods previously described by our group [11]. For the general anesthesia group, procedural details and outcomes were extracted from published literature.

Outcome measures and data collection

We collected a range of clinical and perioperative data for the local anesthesia cohort from medical records : patient demographics (age, sex), operative notes (levels operated, operative time), length of stay (LOS, in days), preoperative and postoperative pain scores and functional scores, and any complications. Pain was assessed using the Visual analog scale (VAS), separately for neck pain (VAS-N) and arm pain (radicular pain, VAS-A), on the 0–10 scale. Postoperative VAS scores were recorded at the last follow-up (which ranged from 6 weeks to 6 months for our local patients). Functional status was measured by Oswestry disability index (ODI) or Neck disability index (NDI), depending on the study; in our local group, we primarily used NDI (which is scaled 0–100% disability like ODI). For analysis, we combined ODI/NDI by converting NDI to a 0–100 scale so it could be treated similarly to ODI (since both indices measure disability percentage). We noted whether patients achieved the minimally clinically important difference (MCID) in VAS scores, which we defined a priori as a ≥50% reduction in pain score [5]. This threshold is consistent with published MCID values for arm pain in cervical radiculopathy.

For the general anesthesia group data from literature, we extracted the analogous information : mean pre- and postoperative VAS-N and VAS-A, mean ODI/NDI pre- and post-op, average LOS, and reported complications in each study. Since each source had different follow-up times (ranging from 6 weeks to 24 months post-op), we used the latest reported follow-up score for pain and function from each study to represent “postoperative” status. We tabulated the complication types and rates from each study as well. “Complications” in our analysis included any perioperative or postoperative adverse events related to the surgery, including neurological deficits (e.g., nerve root palsy, dysesthesia), dural tears, infections, hematomas, or reoperations for recurrence. We also captured recurrences of radiculopathy and whether a reoperation was done, as reported in those studies, and incorporated those into an overall complication count for the general group.

Statistical analysis

We used both descriptive and inferential statistics to compare the local vs. general anesthesia groups. Continuous variables (VAS scores and LOS) are presented as mean±standard deviation. Categorical variables such as complication occurrence are presented as counts and percentages. Given the differing nature of the two cohorts (a small single-institution series vs. pooled literature data), we pooled estimates and adjusted for confounder effects using stratified analysis.

For within group changes in the local anesthesia group, we assessed the significance of pre- to postoperative changes in VAS and ODI/NDI using paired t-tests (for approximately normally distributed data). This allowed us to confirm that the improvements in pain and disability in this group were statistically significant. Each patient’s pre- and post-op scores were paired for this test. For the general anesthesia literature data, we assume that reported improvements were significant as per those studies, but we did not have individual patient data to test; still, all studies reported substantial improvements post-surgery consistent with p<0.05 in their cohorts.

To compare between the local and general anesthesia groups, Welch’s t-test was used due to unequal variances between groups. For VAS improvements and LOS, given the sample size disparity, we also confirmed using a non-parametric Mann-Whitney U test. We report p-values for comparisons of final outcomes between groups (e.g., postoperative VAS, amount of VAS change, LOS). A p<0.05 was considered statistically significant. We also computed the percentage pain reduction for each group (post-op VAS divided by pre-op VAS, subtracted from 1) to compare relative improvement. For complication rate, we used Fisher’s test to account for the smaller sample size.

Furthermore, to provide a more rigorous comparison for the general anesthesia data, we conducted a simple meta-analysis of the complication rates across the eight literature studies. We employed a random-effects model (DerSimonian-Laird method) given the heterogeneity in study designs. This yielded a pooled complication rate with 95% confidence interval (CI) for PECF under general anesthesia. We also calculated the weighted mean improvements in VAS for the general group. However, since patient-level data were not available, formal meta-analysis for continuous outcomes (pain scores) was not feasible beyond pooling the reported means. Instead, we present the range of outcomes and the weighted means for illustrative comparison.

All statistical analysis was performed using Microsoft Excel (Microsoft, Seattle, WA, USA) and Python 3.9.7 (with SciPy library; Python Software Foundation, Wilmington, DE, USA) for calculations. Given the exploratory nature of this study, we focus on effect sizes and confidence intervals in addition to p-values, to interpret clinical relevance. No adjustment for multiple comparisons was made, as the comparisons were limited and derived from our a priori hypotheses.

All statistical analysis was performed using Microsoft Excel (Microsoft) and Python 3.9.7 (with SciPy library; Python Software Foundation) for calculations. Given the exploratory nature of this study, we focus on effect sizes and confidence intervals in addition to p-values, to interpret clinical relevance. No adjustment for multiple comparisons was made, as the comparisons were limited and derived from our a priori hypotheses

RESULTS

Patient demographics and baseline characteristics

For the local anesthesia cohort, we identified 13 patients meeting the inclusion criteria. These included nine males and four females, with a mean age of 56.92±8.17 years. The general anesthesia literature review yielded an aggregated total of 357 patients across eight studies .The local anesthesia group was significantly older compared to the general anesthesia group (50.22±4.59 years; p=0.0238), and the overall sex distribution was approximately 60.5% male (247/357) and 39.5% female (Table 1).

Table 1.

Cohort distributions and clinical characteristics

In terms of pathology, all patients in both cohorts had single-level unilateral cervical radiculopathy. The most common levels operated in our local group were C5-6 and C6-7, accounting for 10 of 13 cases, followed by C4-5 in three cases. The indications were foraminal soft disc herniation in eight patients and foraminal bony stenosis in five patients. We do not have an exact breakdown of levels for the literature group (each study varied), but collectively C5-6 and C6-7 were also the most frequently treated level in those studies, which is typical for degenerative cervical radiculopathy.

Baseline pain scores were recorded for all patients. In the local anesthesia group, the mean preoperative VAS-N (neck pain) was 4.93±1.39 and mean preoperative VAS-A (arm/radicular pain) was 8.69±0.69. These values indicate that radicular pain was the dominant symptom, often far more severe than neck pain, which is expected in pure foraminal compression cases. In the general anesthesia group, the weighted mean pre-op VAS-N was approximately 4.80±1.23 and VAS-A 6.71±1.21. The literature cohort had, on average, slightly lower arm pain scores preoperatively than the local group, potentially reflecting differences in patient selection or timing of surgery.

Preoperative ODI/NDI scores were significantly higher in the local anesthesia group (54.76%±18.88%; 95% CI, 43.35–66.17) compared to the general anesthesia group (39.92%±13.91%; 95% CI, 38.47–41.36; p=0.0153). However, postoperative ODI/NDI scores did not differ significantly between groups (local : 9.82%±3.39%; general : 9.62%±3.35%; p=0.8359) (Table 2 and Fig. 1).

Table 2.

Clinical outcomes of local and general anesthesia groups with standard deviations

Fig. 1.

Comparison of clinical metrics between local and general anesthesia. The figure shows a comparison of various clinical metrics between patients who received local anesthesia and those who received general anesthesia. A : VAS scores, MCID, and LOS : the mean values of pre VAS-B, post VAS-B, pre VAS-LE, post VAS-LE, MCID, and LOS. B : ODI scores : the mean values of pre ODI and post ODI. VAS : Visual analog scale, MCID : minimally clinically important difference, LOS : length of stay, VAS-N : Visual analog scale for neck pain, VAS-A : Visual analog scale for arm pain, ODI : Oswestry disability index, NDI : Neck disability index, VAS-LE : Visual analog scale-lower extremity.

Pain and functional outcomes

For the local Anesthesia group, the pre- and postoperative VAS scores for each patient were analyzed. VAS-N improved from a mean of 4.93±1.39 pre-op to 1.49±0.80 at follow-up (typically 6–12 weeks post-op for local anesthesia patients). Showing a mean reduction of 3.44 points (69.8% reduction). VAS-A improved from a mean of 8.69±0.69 pre-op to 1.85±0.85 postop, a mean reduction of 6.85 points with p<0.001 for both VAS-N and VAS-A. This corresponds to percentage reduction in arm pain of 78.8%, indicating that on average, patients were left with about 21% of their original arm pain after PECF under local anesthesia, inidciating minimal residual pain (Table 2 and Fig. 1A). All of local anesthesia patients met the MCID for arm pain and 92% met it for neck pain.

Functional outcome in the local group, measured by NDI (n=10 patients) or ODI (n=3 patients, converted to percent), also showed marked improvement. The average preoperative ODI/NDI was 54.76%, which improved to 9.82% postoperatively, showing 82.1% reductction (Table 2 and Fig. 1B). Essentially, patients went from a moderate-severe disability range to minimal disability. This magnitude of improvement resulting in 44.94% decrease is indicidicative of clinical sigfnificance. Patients reported being able to return to daily activities and work (if applicable) much more readily after surgery.

For the general anesthesia group, the outcomes were also favorable. The mean VAS-N in the general group improved from 4.80±1.23 pre-op to 1.28±0.71 post-op, resulting in a 3.52-point improvement (73.3% reduction). VAS-A improved from 6.71±1.21 to 1.23±0.48 (a 5.48-point improvement). This corresponds to an average 81.7% reduction in arm pain. All general anesthesia studies reported significant pain improvements individually (p<0.05). An independent t-test comparing the final VAS-A of local vs general groups yields p=0.54, indicating no difference in final pain level. Functional outcomes in the general anesthesia group improved from an average ODI 39.92%±13.91% to 9.62%±3.35% (75.9% improvement), also showing clinical significance.

Length of stay

The length of stay after surgery was analyzed as an indicator of recovery speed and healthcare utilization. Mean LOS was slightly longer in the local anesthesia group (5.85±2.02 days; 95% CI, 4.63–7.06) compared to the general anesthesia group (4.81±1.68 days; 95% CI, 4.63–4.98), but the difference did not reach statistical significance (p=0.0905).

Complications and safety

In the local anesthesia group, there were 0 intraoperative or postoperative complications documented among the 13 cases. No patient in this group experienced a new neurological deficit, no instances of dural tear or cerebrospinal fluid leak occurred, and there were no infections or hematomas. During the follow-up period, none of these 13 patients had a recurrence of radiculopathy that required a reoperation. The 95% CI for this 0% complication rate is 0–22.8%, reflecting the limitations of the small sample size (Table 3).

Table 3.

Complications and complication rates comparing local and general anesthesia groups

In the general anesthesia group (n=357), a variety of complications were reported across the studies. Overall, there were 31 patients with complications, yielding an aggregated complication rate of 8.68%. A random-effects meta-analysis of the proportion gives a pooled rate of approximately 9.8% (95% CI, 6–12%). For simplicity, we report 8.7% as that was directly calculated from summing events and dividing by total patients (Table 3).

The types of complications in the general anesthesia group included transient nerve root deficits (C5 palsy symptoms), dysesthesias, one small epidural hematoma requiring observation, dural tears without neurological consequence, and cases requiring re-operation for residual or recurrent pain. Complication rates varied significantly across studies, from 0% to 29.4%, with an aggregate rate of 8.68% compared to 0% in the local anesthesia group (p=0.612). No patient in either group experienced severe permanent deficits, infections, vascular injuries, or cervical instability (Table 3).

DISCUSSION

PECF under local anesthesia with conscious sedation in the lateral decubitus position demonstrated effective pain relief and functional improvement comparable to general anesthesia. The local anesthesia group showed comparable pain reduction, aligning with previous studies on local anesthesia benefits in spine surgery [19,27]. Both groups achieved MCID, indicating clinically meaningful improvements. The local anesthesia group had a higher MCID for arm pain reduction (6.85±2.36; 95% CI, 5.42 to 8.27) compared to the general group (5.48±1.91; 95% CI, 5.28 to 5.67), with the difference approaching statistical significance (p=0.0597). Notably, the awake local anesthesia technique did not compromise efficacy, with pain reduction and functional improvement in the local anesthesia group on par with the general anesthesia cohort.

A notable finding was the absence of complications in the local anesthesia group, compared to 8.68% in the general anesthesia group (95% CI, 5.8–11.6%), derived from a random-effects meta-analysis of pooled literature data. Although this difference was not statistically significant (p=0.612) due to the small local sample size, this finding is purely descriptive and hypothesis-generating. The wide confidence interval (0–22.8%) for our 0% complication rate indicates substantial uncertainty and could encompass rates similar to or even higher than the general anesthesia group [2,23]. This difference suggests that local anesthesia may mitigate certain risks associated with general anesthesia and prone positioning. However, complication rates among the general anesthesia studies varied widely, ranging from 0% to 29.41%, highlighting the influence of factors such as surgeon and anesthesiologist experience, patient selection, and specific surgical techniques. While our study was not powered to prove a statistically significant safety difference, the complete absence of complications in the local group is hypothesis-generating and warrants further investigation.

Complications in the general anesthesia cohort included perioperative issues like hypesthesia, postoperative problems such as transient nerve root palsy, dural tears with associated cerebrospinal fluid leak, and hematoma formation, as well as instances of recurrence and revision surgeries [10,16,17,22,24,28,30,32]. The local anesthesia approach might mitigate these risks by allowing for immediate detection and correction of potential nerve irritation, and more precise decompression [31]. Additionally, the lateral decubitus position used in the local anesthesia approach may reduce the risk of increased intraocular pressure and subsequent vision loss, a rare but serious complication associated with prone positioning under general anesthesia [6]. As more cases are added to the local anesthesia cohort, a larger sample size will provide more robust data for comparison. While the current absence of complications in the local anesthesia group is promising, it reflects a smaller sample size and further research is needed to definitively establish the comparative safety profiles of these two approaches.

Functional outcomes measured by ODI/NDI demonstrated substantial recovery in both groups. The local anesthesia group experienced greater absolute functional improvement (from 54.76% pre-op to 9.82% post-op) compared to the general anesthesia group (from 39.92% pre-op to 9.62% post-op). However, this difference likely reflects the local group’s higher preoperative disability rather than direct superiority of surgical technique. Nevertheless, significant functional improvements observed with local anesthesia may also be attributed to reduced systemic stress, less invasive perioperative management, and enhanced early mobilization potential, consistent with previous literature [7,21].

Functional outcomes measured by ODI/NDI improvements indicate substantial recovery in both groups, with the local anesthesia group showing comparatively greater improvement. This suggests that the local anesthesia approach may offer superior functional outcomes, possibly due to reduced tissue trauma or improved patient comfort during the procedure.

Overall, the baseline imbalance between groups, with the local anesthesia group having significantly higher preoperative pain and disability scores, could potentially bias absolute improvement measures in favor of the local group. However, our analysis of percent improvements shows that both groups achieved similar relative reductions in pain (78.8% vs. 81.7% for VAS-A) and disability (82.1% vs. 75.9% for ODI/NDI). This indicates that despite starting from different baselines, both techniques produced comparable relative improvements, supporting the clinical equivalence of the two approaches.

The unexpectedly longer LOS in the local anesthesia group may be explained by the older average age of this cohort (56.92 vs. 50.22 years in the general anesthesia group), as older patients typically require more time for recovery and may have more complex medical needs during their hospital stay. However, it is also important to consider cultural context to understand the LOS. The senior author of our study as well as the authors of other papers we reference (Kim et al. [16], Kim et al. [17], and Youn et al. [32]) are based in South Korea. In the Korean healthcare system, it is common for patients to have longer hospital stays for postoperative care compared to Western practices. This cultural norm likely contributes to the overall longer LOS observed in both groups in our study. The difference between the two groups might also be attributed to variations in postoperative care protocols and patient demographics, all within the context of South Korean healthcare practices [20].

The older age of the local group also hints at an important point. Surgeons might naturally choose local anesthesia for older, comorbid patients. This suggests the awake technique can expand the pool of patients eligible for surgery. Patients with significant medical history for surgery due to high general anesthesia risk (e.g., severe chronic obstructive pulmonary disease, older age, etc.) could potentially get relief via an awake PECF, avoiding the need for general anesthesia clearance [26]. Khan et al. [14] demonstrated that multiple-comorbidity patients could undergo lumbar decompressions under local safely. Our results, adjusted for age, further support extending this into cervical spine. Thus, the availability of this technique can make surgical treatment accessible to patients who otherwise might only be managed non-operatively due to anesthesia concerns.

Overall, these findings support PECF under local anesthesia with conscious sedation as an effective alternative, especially for high-risk patients. The use of local anesthesia may contribute to favorable outcomes by reducing systemic anesthetic risks and allowing for real-time patient feedback during the procedure [21,31]. This feedback mechanism may explain our observed lower complication rate, as the surgeon can immediately respond to patient reports of pain or neurological symptoms during critical steps of the operation. Wu et al. [31] reported that local anesthesia in spinal procedures can lead to shorter recovery times and reduced postoperative complications compared to general anesthesia. Local anesthesia avoids the systemic effects of general anesthetics, which is particularly beneficial for patients with cardiopulmonary comorbidities or advanced age [7]. Malham et al. [21] also noted that local anesthesia techniques in spinal surgery can lead to improved postoperative pain control and earlier mobilization. The combination of local anesthesia with minimal sedation also allows for easier management of intraoperative blood pressure and oxygenation, which can be crucial in maintaining adequate perfusion to the spinal cord and nerve roots during the procedure [29].

Study limitations include its retrospective nature, potential selection bias, and comparison with published data rather than a direct control group. The small sample size of the local anesthesia group (13 patients) compared to the general anesthesia group (357 patients) is a significant limitation that may affect the generalizability of the results and explains why a 0% complication rate should be interpreted cautiously (95% CI, 0–22.8%). We acknowledge that a larger prospective study with matched cohorts would provide stronger evidence. Our statistical analysis employed random-effects meta-analysis for the general anesthesia group complication rates to account for heterogeneity, but more robust statistical methods could strengthen future studies. As discussed above, the local anesthesia group was limited to one country and cultural context; patient populations may vary worldwide with regard to factors such as American Society of Anesthesiologists grade, body mass index, and comorbidities influencing anesthesia choice. Additionally, the heterogeneity of the general anesthesia studies, as evidenced by the varying outcomes and complication rates (0% to 29.4%), introduces potential confounding factors that we attempted to address through pooled analysis.

CONCLUSION

PECF under local anesthesia with conscious sedation in the lateral decubitus position appears to be a safe and effective alternative to the traditional method. The significant reduction in postoperative pain and improved functional outcomes observed in the local anesthesia group, along with the descriptive finding of no complications in our small sample, suggest this approach should be considered, particularly for older patients or those at higher risk for general anesthesia. However, the small local anesthesia sample size and heterogeneity among general anesthesia studies limit the generalizability of these findings. Future prospective, randomized controlled trials with larger sample sizes, matched patient demographics, and longer follow-up periods are needed to validate these findings and explore additional benefits of this innovative approach.

Notes

Conflicts of interest

No potential conflict of interest relevant to this article was reported.

Informed consent

This type of study does not require informed consent.

Author contributions

Conceptualization : BCR, JKL, DHL, CPH, PK; Data curation : JKL; Formal analysis : JKL; Methodology : JKL, DHL, JMB, DZ, MNN; Project administration : JKL, MR; Visualization : JKL; Writing - original draft : JKL; Writing - review & editing : JKL, MR, SK, BCR, DHL, CPH, PK, DZ, JMB

Data sharing

None

Preprint

None

References

1. Adamson TE. Microendoscopic posterior cervical laminoforaminotomy for unilateral radiculopathy: results of a new technique in 100 cases. J Neurosurg 95:51–57. 2001;

2. Ahn Y. Percutaneous endoscopic cervical discectomy using working channel endoscopes. Expert Rev Med Devices 13:601–610. 2016;

3. Bono CM, Ghiselli G, Gilbert TJ, Kreiner DS, Reitman C, Summers JT, et al. An evidence-based clinical guideline for the diagnosis and treatment of cervical radiculopathy from degenerative disorders. Spine J 11:64–72. 2011;

4. Carette S, Fehlings MG. Clinical practice. Cervical radiculopathy. N Engl J Med 353:392–399. 2005;

5. Copay AG, Glassman SD, Subach BR, Berven S, Schuler TC, Carreon LY. Minimum clinically important difference in lumbar spine surgery patients: a choice of methods using the Oswestry Disability Index, Medical Outcomes Study questionnaire Short Form 36, and pain scales. Spine J 8:968–974. 2008;

6. Cunha PD, Barbosa TP, Correia G, Silva R, Cruz Oliveira N, Varanda P, et al. The ideal patient positioning in spine surgery: a preventive strategy. EFORT Open Rev 8:63–72. 2023;

7. Cuvillon P, Lefrant JY, Gricourt Y. Considerations for the use of local anesthesia in the frail elderly: current perspectives. Local Reg Anesth 15:71–75. 2022;

8. Edgcombe H, Carter K, Yarrow S. Anaesthesia in the prone position. Br J Anaesth 100:165–183. 2008;

9. Fessler RG, Khoo LT. Minimally invasive cervical microendoscopic foraminotomy: an initial clinical experience. Neurosurgery 51(5 Suppl):S37–S45. 2002;

10. Gatam AR, Gatam L, Phedy , Mahadhipta H, Luthfi O, Ajiantoro , et al. Full endoscopic posterior cervical foraminotomy in management of foraminal disc herniation and foraminal stenosis. Orthop Res Rev 14:1–7. 2022;

11. Han KT, Lee HJ, Park EC, Kim W, Jang SI, Kim TH. Length of stay and readmission in lumbar intervertebral disc disorder inpatients by hospital characteristics and volumes. Health Policy 120:1008–1016. 2016;

12. Hofstetter CP, Ahn Y, Choi G, Gibson JNA, Ruetten S, Zhou Y, et al. AOSpine consensus paper on nomenclature for working-channel endoscopic spinal procedures. Global Spine J 10(2 Suppl):111S–121S. 2020;

13. Kang SY, Kashlan ON, Singh R, Rane R, Adsul NM, Jung SC, et al. Advantages of the combination of conscious sedation epidural anesthesia under fluoroscopy guidance in lumbar spine surgery. J Pain Res 13:211–219. 2020;

14. Khan MB, Kumar R, Enam SA. Thoracic and lumbar spinal surgery under local anesthesia for patients with multiple comorbidities: a consecutive case series. Surg Neurol Int 5(Suppl 3):S62–S65. 2014;

15. Kim CH, Kim KT, Chung CK, Park SB, Yang SH, Kim SM, et al. Minimally invasive cervical foraminotomy and diskectomy for laterally located soft disk herniation. Eur Spine J 24:3005–3012. 2015;

16. Kim HS, Wu PH, Lee YJ, Kim DH, Kim JY, Lee JH, et al. Safe route for cervical approach: partial pediculotomy, partial vertebrotomy approach for posterior endoscopic cervical foraminotomy and discectomy. World Neurosurg 140:e273–e282. 2020;

17. Kim JY, Hong HJ, Lee DC, Kim TH, Hwang JS, Park CK. Comparative analysis of 3 types of minimally invasive posterior cervical foraminotomy for foraminal stenosis, uniportal-, biportal endoscopy, and microsurgery: radiologic and midterm clinical outcomes. Neurospine 19:212–223. 2022;

18. Komp M, Oezdemir S, Hahn P, Ruetten S. Full-endoscopic posterior foraminotomy surgery for cervical disc herniations. Oper Orthop Traumatol 30:13–24. 2018;

19. Lee JS, Park YM, Ha KY, Cho SW, Bak GH, Kim KW. Preoperative anxiety about spinal surgery under general anesthesia. Eur Spine J 25:698–707. 2016;

20. Lim DH, Kim S, Lim JK, Sivakanthan S, Meyer RM, Kim P, et al. Endoscopic posterior cervical foraminotomy under lateral decubitus position with local anesthesia. World Neurosurg 186:e456–e460. 2024;

21. Malham GM, Wagner TP, Claydon MH. Anterior lumbar interbody fusion in a lateral decubitus position: technique and outcomes in obese patients. J Spine Surg 5:433–442. 2019;

22. Oertel JM, Philipps M, Burkhardt BW. Endoscopic posterior cervical foraminotomy as a treatment for osseous foraminal stenosis. World Neurosurg 91:50–57. 2016;

23. Platt A, Gerard CS, O'Toole JE. Comparison of outcomes following minimally invasive and open posterior cervical foraminotomy: description of minimally invasive technique and review of literature. J Spine Surg 6:243–251. 2020;

24. Ruetten S, Komp M, Merk H, Godolias G. Full-endoscopic cervical posterior foraminotomy for the operation of lateral disc herniations using 5.9-mm endoscopes: a prospective, randomized, controlled study. Spine (Phila Pa 1976) 33:940–948. 2008;

25. Sairyo K, Chikawa T, Nagamachi A. State-of-the-art transforaminal percutaneous endoscopic lumbar surgery under local anesthesia: discectomy, foraminoplasty, and ventral facetectomy. J Orthop Sci 23:229–236. 2018;

26. Schwilk B, Bothner U, Schraag S, Georgieff M. Perioperative respiratory events in smokers and nonsmokers undergoing general anaesthesia. Acta Anaesthesiol Scand 41:348–355. 1997;

27. Sivakanthan S, Hasan S, Hofstetter C. Full-endoscopic lumbar discectomy. Neurosurg Clin N Am 31:1–7. 2020;

28. Tacconi L, Signorelli F, Giordan E. Cervical foraminotomy by full-endoscopic posterior cervical approach: a randomized study. Interdiscip Neurosurg 26:101287. 2021;

29. Vincenzi P, Starnari R, Faloia L, Grifoni R, Bucchianeri R, Chiodi L, et al. Continuous thoracic spinal anesthesia with local anesthetic plus midazolam and ketamine is superior to local anesthetic plus fentanyl in major abdominal surgery. Surg Open Sci 2:5–11. 2020;

30. Wu PH, Kim HS, Lee YJ, Kim DH, Lee JH, Yang KH, et al. Posterior endoscopic cervical foramiotomy and discectomy: clinical and radiological computer tomography evaluation on the bony effect of decompression with 2 years follow-up. Eur Spine J 30:534–546. 2021;

31. Wu Z, He J, Cheng H, Zhang P, Liang D, Jiang X, et al. Clinical efficacy of general anesthesia versus local anesthesia for percutaneous transforaminal endoscopic discectomy. Front Surg 9:1076257. 2023;

32. Youn MS, Shon MH, Seong YJ, Shin JK, Goh TS, Lee JS. Clinical and radiological outcomes of two-level endoscopic posterior cervical foraminotomy. Eur Spine J 26:2450–2458. 2017;

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Group	Total patients	Male	Female	Age (years)
Local	13	9 (69.2)	4 (30.8)	56.92±8.17
General	357	247 (60.5)	161 (39.5)	50.22±4.59
Gatam et al. [10]	65	34 (52.3)	31 (47.7)	45.6
Ruetten et al. [24]	87	39 (44.8)	48 (55.2)	44.0
Oertel et al. [22]	43	27 (62.8)	16 (37.2)	55.3
Kim et al. [16]	30	23 (76.7)	7 (23.3)	50.7
Kim et al. [17]	68	48 (70.6)	20 (29.4)	53.6
Wu et al. [30]	25	16 (64.0)	9 (36.0)	51.8
Tacconi et al. [28]	17	9 (52.9)	8 (47.1)	44.5
Youn et al. [32]	22	13 (59.1)	9 (40.9)	56.2

	Pre VAS-N	Post VAS-N	% ∆	Pre VAS-A	Post VAS-A	% ∆	MCID	Pre ODI/NDI	Post ODI/NDI	% ∆	LOS (days)
Local	4.93±1.32	1.49±0.52	69.8	8.69±0.75	1.85±1.46	78.8	6.85±2.36	54.76±18.88	9.82±3.39	82.1	5.85±3.20
General	4.80±1.23	1.28±0.71	73.3	6.71±1.21	1.23±0.48	81.7	5.48±1.91	39.92±13.91	9.62±3.35	75.9	4.81±2.17
Gatam et al. [10]	NR	NR		5	2		3	NR	NR		1.5
Ruetten et al. [24]	1.5	1.6		8.1	0.7		7.4	NR	NR		1.5
Oertel et al. [22]	NR	NR		7.8	2.3		5.5	45.3	11.7		4
Kim et al. [16]	NR	NR		7.6	1.67		5.93	73.93	21.53		NR
Kim et al. [17]	5.53	0.83		7.49	0.69		6.80	24.02	1.13		6.67
Wu et al. [30]	7.28	2.32		NR	NR		NR	71.5	26.4		NR
Tacconi et al. [28]	NR	NR		8.2	2.4		5.8	44.6	10.5		NR
Youn et al. [32]	1.3	2.3		6.9	0.9		6	29.5	10.8		2

	Perioperative complication	Postoperative complication (medical and/or surgical)	Recurrence and/or revision	Complications (including recurrence)	Complication rate (%)
Local				0	0.00
General	7	15	9	31	8.68
Gatam et al. [10]	4 hypesthesia			4	6.15
Ruetten et al. [24]	3 transient, dermatoma-related hypesthesia		3 (persistent pain; 2 went under revisions)	6	6.90
Oertel et al. [22]		1 hematoma	1 revision due to worsening tricep paresis	2	4.65
Kim et al. [16]				0	0.00
Kim et al. [17]		3 transient nerve root palsy 1 dural tear	3 recurrence (no revision)	7	10.29
Wu et al. [30]		2 motor deficits (resolved without revision)	1 recurrence (no revision)	3	12.00
Tacconi et al. [28]		4 transient nerve root dysesthesia	1 recurrent radicular pain (revision)	5	29.41
Youn et al. [32]		2 transient root injury 2 superficial wound infection		4	18.18