Best Practices for Outpatient Anterior Cervical Surgery: Results From a Delphi Panel

Safety and Efficacy of Outpatient Anterior Cervical Disk Replacement (ACDR) in an Ambulatory Surgery Center Versus Hospital Setting: A 2-year Retrospective Analysis

STUDY DESIGN

Retrospective cohort analysis.

OBJECTIVE

To compare clinical outcomes of outpatient anterior cervical disk replacements (ACDR) performed in free-standing private ambulatory surgery centers versus tertiary hospital centers.

SUMMARY OF BACKGROUND DATA

ACDR is an increasingly popular technique for treating various degenerative pathologies of the cervical spine. There has been an increase in the utilization of ambulatory surgery centers (ASCs) for outpatient cervical procedures due to economic and convenience benefits; however, a paucity of literature exists in evaluating long-term safety and efficacy of ACDRs performed in ASCs versus outpatient hospital centers.

METHODS

A retrospective cohort review of all patients undergoing 1- or 2-level ACDRs at 2 outpatient ASCs and 4 tertiary care medical centers from 2012 to 2020, with a minimum follow-up of 24 months, was performed. Approval by each patient's insurance and patient preference determined distribution into an ASC or non-ASC. Demographics, perioperative data, length of follow-up, complications, and revision rates were analyzed. Functional outcomes were assessed using VAS and NDI at follow-up visits.

RESULTS

One hundred seventeen patients were included (65 non-ASC and 52 ASC). There were no significant differences in demographics or length of follow-up between the cohorts. ASC patients had significantly lower operative times (ASC: 89.5 minutes vs. non-ASC: 110.5 minutes, P<0.001) and mean blood loss (ASC: 17.5 mL vs. non-ASC: 25.3 mL, P<0.001). No significant differences were observed in rates of dysphagia (ASC: 21.2% vs. non-ASC: 15.6%, P<0.001), infection (ASC: 0.0% vs. non-ASC: 1.6%, P=0.202), ASD (ASC: 1.9% vs. non-ASC: 1.6%, P=0.202), or revision (ASC: 1.9% vs. non-ASC: 0.0%, P=0.262). Both groups demonstrated significant improvements in VAS and NDI scores (P<0.001), but no significant differences in the degree of improvement were observed.

CONCLUSIONS

Our 2-year results demonstrate that ACDRs performed in ASCs may offer the advantages of reduced operative time and blood loss without an increased risk of postoperative complications.

Risk stratification of patients undergoing outpatient lumbar decompression surgery

BACKGROUND CONTEXT

Reimbursement has slowly transitioned from a fee-for-service model to a bundled payment model after introduction of the United States Centers for Medicare and Medicaid Services bundled payment program. To minimize healthcare costs, some surgeons are trying to minimize healthcare expenditures by transitioning appropriately selected lumbar decompression patients to outpatient procedure centers.

PURPOSE

To prepare a risk stratification calculator based on machine learning algorithms to improve surgeon's preoperative predictive capability of determining whether a patient undergoing lumbar decompression will meet inpatient vs. outpatient criteria. Inpatient criteria was defined as any overnight hospital stay.

STUDY DESIGN/SETTING

Retrospective single-institution cohort.

PATIENT SAMPLE

A total of 1656 patients undergoing primary lumbar decompression.

OUTCOME MEASURES

Postoperative outcomes analyzed for inclusion into the risk calculator included length of stay.

METHODS

Patients were split 80-20 into a training model and a predictive model. This resulted in 1,325 patients in the training model and 331 into the predictive model. A logistic regression analysis ensured proper variable inclusion into the model. C-statistics were used to understand model effectiveness. An odds ratio and nomogram were created once the optimal model was identified.

RESULTS

A total of 1,656 patients were included in our cohort with 1,078 dischared on day of surgery and 578 patients spending ≥ 1 midnight in the hospital. Our model determined older patients (OR=1.06, p<.001) with a higher BMI (OR=1.04, p<0.001), higher back pain (OR=1.06, p=.019), increasing American Society of Anesthesiologists (ASA) score (OR=1.39, p=.012), and patients with more levels decompressed (OR=3.66, p<0.001) all had increased risks of staying overnight. Patients who were female (OR=0.59, p=.009) and those with private insurance (OR=0.64, p=.023) were less likely to be admitted overnight. Further, weighted scores based on training data were then created and patients with a cumulative score over 118 points had a 82.9% likelihood of overnight. Analysis of the 331 patients in the test data demonstrated using a cut-off of 118 points accurately predicted 64.8% of patients meeting inpatient criteria compared to 23.0% meeting outpatient criteria (p<0.001). Area under the curve analysis showed a score greater than 118 predicted admission 81.4% of the time. The algorithm was incorporated into an open access digital application available here: https://rothmanstatisticscalculators.shinyapps.io/Inpatient_Calculator/?_ga=2.171493472.1789252330.1671633274-469992803.1671633274 CONCLUSIONS: Utilizing machine-learning algorithms we created a highly reliable predictive calculator to determine if patients undergoing outpatient lumbar decompression would require admission. Patients who were younger, had lower BMI, lower preoperative back pain, lower ASA score, less levels decompressed, private insurance, lived with someone at home, and with minimal comorbidities were ideal candidates for outpatient surgery.

Creation of a Risk Calculator for Predicting New-Onset Cardiac Arrhythmias in Patients Undergoing Lumbar Fusion

INTRODUCTION

As an increasing number of lumbar fusion procedures are being conducted at specialty hospitals and surgery centers, appropriate patient selection and risk stratification is critical to minimizing patient transfers. Postoperative cardiac arrhythmia has been linked to worse patient outcomes and is a common cause of patient transfer. Therefore, we created a risk calculator to predict a patient's likelihood of developing a new-onset postoperative cardiac arrhythmia after lumbar spinal fusion, which may improve preoperative facility selection.

METHODS

A retrospective review was conducted of patients who undergoing lumbar fusion from 2017 to 2021 at a single academic center. Patients were excluded if they had any medical history of a cardiac arrhythmia. Multivariable regression was conducted to determine independent predictors of inpatient arrhythmias. The final regression was applied to a bootstrap to validate an arrhythmia prediction model. A risk calculator was created to determine a patient's risk of new-onset cardiac arrhythmia.

RESULTS

A total of 1,622 patients were included, with 45 patients developing a new-onset postoperative arrhythmia. Age (OR = 1.05; 95% CI, 1.02 to 1.09; P = 0.003), history of beta-blocker use (OR = 2.01; 95% CI, 1.08 to 3.72; P = 0.027), and levels fused (OR = 1.59; 95% CI, 1.20 to 2.00; P = 0.001) were all independent predictors of having a new-onset inpatient arrhythmia. This multivariable regression produced an area under the curve of 0.742. The final regression was applied to a bootstrap prediction modeling technique to create a risk calculator including the male sex, age, body mass index, beta-blocker use, and levels fused (OR = 1.04, [CI = 1.03 to 1.06]) that produced an area under the curve of 0.733.

CONCLUSION

A patient's likelihood of developing postoperative cardiac arrhythmias may be predicted by comorbid conditions and demographic factors including age, sex, body mass index, and beta-blocker use. Knowledge of these risk factors may improve appropriate selection of an outpatient surgical center or orthopaedic specialty hospital versus an inpatient hospital for lumbar fusions.

Opioid prescription trends after ambulatory anterior cervical discectomy and fusion

BACKGROUND CONTEXT

Opioid utilization has been well studied for inpatient anterior cervical discectomy and fusion (ACDF). However, the amount and type of opioids prescribed following ambulatory ACDF and the associated risk of persistent use are largely unknown.

PURPOSE

To characterize opioid prescription filling following single-level ambulatory ACDF compared with inpatient procedures.

STUDY DESIGN/SETTING

Retrospective cohort study.

PATIENT SAMPLE

Opioid-naive patients who underwent ambulatory (no overnight stay) or inpatient single-level ACDF from 2011 to 2019 were identified from a national insurance database.

OUTCOME MEASURES

Rate, amount, and type of perioperative opioid prescription.

METHODS

Opioid-naive patients who underwent ambulatory (no overnight stay) or inpatient single-level ACDF from 2011 to 2019 were identified from a national insurance database. Perioperative opioids were defined as opioid prescriptions 30 days before and 14 days after the procedure. Rate, amount, and type of opioid prescription were characterized. Multivariable analyses controlling for any differences in demographics and comorbidities between the two treatment groups were utilized to determine any association between surgical setting and persistent opioid use (defined as the patient still filling new opioid prescriptions >90 days postoperatively).

RESULTS

A total of 42,521 opioid-naive patients were identified, of which 2,850 were ambulatory and 39,671 were inpatient. Ambulatory ACDF was associated with slightly increased perioperative opioid prescription filling (52.7% vs 47.3% for inpatient procedures; p<.001). Among the 20,280 patients (47.7%) who filled perioperative opioid prescriptions, the average amount of opioids prescribed (in morphine milligram equivalents) was similar between ambulatory and inpatient procedures (550 vs 540, p=.413). There was no association between surgical setting and persistent opioid use in patients who filled a perioperative opioid prescription, even after controlling for comorbidities, (adjusted odds ratio, 1.15, p=.066).

CONCLUSIONS

Ambulatory ACDF patients who filled perioperative opioid prescriptions were prescribed a similar amount of opioids as those undergoing inpatient procedures. Further, ambulatory ACDF does not appear to be a risk factor for persistent opioid use. These findings are important for patient counseling as well as support the safety profile of this new surgical pathway.

Ultrasound-Guided Blocks for Spine Surgery: Part 1-Cervix

Postoperative pain is common following spine surgery, particularly complex procedures. The main anesthetic efforts are focused on applying multimodal analgesia beforehand, and regional anesthesia is a critical component of it. The purpose of this study is to examine the existing techniques for regional anesthesia in cervical spine surgery and to determine their effect and safety on pain reduction and postoperative patient's recovery. The electronic databases were searched for all literature pertaining to cervical nerve block procedures. The following peripheral, cervical nerve blocks were selected and described: paravertebral block, cervical plexus clock, paraspinal interfascial plane blocks such as multifidus cervicis, retrolaminar, inter-semispinal and interfacial, as well as erector spinae plane block and stellate ganglion block. Clinicians should choose more superficial techniques in the cervical region, as they have been shown to be comparably effective and less hazardous compared to paravertebral blocks.

Multimodal analgesic protocol for cervical disc replacement in the ambulatory setting: Clinical case series

Background

Effective pain management is paramount for outpatient surgical success. This study aims to report a case series of patients undergoing cervical disc replacement (CDR) in an ambulatory surgery center (ASC) with the use of an enhanced multimodal analgesic (MMA) protocol.

Methods

Primary, single-/2-level CDR procedures at an ASC with an enhanced MMA protocol were included. ASC patients were discharged day of surgery. Patient-reported outcome measures (PROMs) were administered at preoperative/6-week/12-week/6-month/1-year/2-year timepoints and included Visual Analogue Scale (VAS) neck, VAS arm, Neck Disability Index (NDI), Patient-Reported Outcomes Measurement Information System-Physical Function (PROMIS-PF), and 12-Item Short-Form Physical and Mental Composite Score (SF-12 PCS/SF-12 MCS). A t-test assessed postoperative PROM improvement from baseline. MCID achievement was determined by comparing ΔPROM scores to previously established thresholds.

Results

106 patients were included, 76 single-level and 30 2-level. Most single-levels occurred at C5-C6, most 2-levels at C5-C7. One 2-level patient developed a hematoma 5 days postoperatively and underwent revision for evacuation. Five patients reported postoperative dysphagia; all were quickly resolved. One patient had an episode of seizure secondary to serotonin syndrome from concealed drug use. Patient was reintubated, transferred, and treated for serotonin syndrome. Two patients experienced postoperative nausea/vomiting. Cohort significantly improved from baseline for all PROMS at all timepoints except SF-12 MCS at 1-year/2-years and SF-12 PCS at 2 years (p < 0.047, all). Overall MCID achievement rates were: VAS arm (48.7%), VAS neck (69.1%), NDI (98.9%), SF-12 MCS (50.0%), SF-12 PCS (54.6%), and PROMIS-PF (73.4%).

Conclusion

Outpatient CDR, incorporating an enhanced MMA protocol, can be safely and effectively performed with proper patient selection and surgical technique. Patients saw timely discharge, well-controlled postoperative pain, and favorable long-term outcomes.

Spine Surgery Complications in the Ambulatory Surgical Center Setting: Systematic Review

STUDY DESIGN

This was a systematic review study.

PURPOSE

This study aims to review current literature to determine the rates of complications in relation to spine surgery in ambulatory surgery centers (ASC).

BACKGROUND

Recent improvements in anesthesia, surgical techniques, and technological advances have facilitated a rise in the use of ASC. Despite the benefits and lower costs associated with ASCs, there is inconsistent reporting of complication rates.

METHODS

This systematic review was completed utilizing the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Pertinent studies were identified through Embase and PubMed databases using the search string ((("ambulatory surgery center") AND "spine surgery") AND "complications"). Articles were excluded if they did not report outpatient surgery in an ASC, did not define complications, were in a language other than English, were non-human studies, or if the articles were classified as reviews, book chapters, single case reports, or small case series (≤10 patients). The primary outcome was the frequency of complications with respect to various categories.

RESULTS

Our query identified 150 articles. After filtering relevance by title, abstract, and full text, 22 articles were included. After accounting for 2 studies that were conducted on the same study sample, a total of 11,245 patients were analyzed in this study. The most recent study reported results from May 2019. While 5 studies did not list their surgical technique, studies reported techniques including open (6), minimally invasive surgery (2), endoscopic (4), microsurgery (1), and combined techniques (4). The following rates of complications were determined: cardiac 0.29% (3/1027), vascular 0.25% (18/7116), pulmonary 0.60% (11/1839), gastrointestinal 1.12% (2/179), musculoskeletal/spine/operative 0.59% (24/4053), urologic 0.80% (2/250), transient neurological 0.67% (31/4616), persistent neurological 0.61% (9/1479), pain related 0.57% (20/3479), and wound site 0.68% (28/4092).

CONCLUSIONS

After literature review, this is the first study to comprehensively analyze the current state of literature reporting on the complication profile of all ASC spine surgery procedures. The most common complications were gastrointestinal (1.12%) and the most infrequent were vascular (0.25%). Case reports varied significantly with regard to the type and rate of complications reported. This study provides complication profiles to assist surgeons in counseling patients on the most realistic expectations.

Impact of Surgeon Experience on Outcomes of Anterior Cervical Discectomy and Fusion

INTRODUCTION

The relationship between surgeon experience and cervical fusion outcomes has yet to be assessed. We investigate perioperative characteristics, patient-reported outcomes (PROMs), and minimal clinically important difference (MCID) achievement after anterior cervical diskectomy and fusion (ACDF) by the volume of cases done throughout an orthopaedic spine surgeon's career.

METHODS

ACDF procedures between 2005 and 2020 were identified. Group I included the first half of ACDF cases (#1-#321). PROMs were introduced in the second half of the ACDF cases; thus, the next 322 cases were subdivided to compare PROM and MCID between subgroups (cases #322 to #483 = group II and #484 to #645 = group III). PROMs, including VAS back/leg, Oswestry Disability Index (ODI), Short Form-12 Physical Composite Score, and PROMIS-PF, were collected preoperatively/postoperatively. Demographics, perioperative variables, mean PROMs, and MCID achievement were compared between groups and subgroups using the Student t-test and chi-square. Logistic regression evaluated MCID achievement using the established threshold values.

RESULTS

A total of 642 patients were included (320 in group I, 161 in group II, and 161 in group III). The latter cases had significantly decreased surgical time, blood loss, and postoperative length of stay in comparison of groups and subgroups (P ≤ 0.002, all). CT-confirmed 1-year arthrodesis rates were increased among the latter cases (P = 0.045). Group II had significantly higher arthrodesis rates than group III (P = 0.039). The postoperative complication rates were lower in the latter cases (P < 0.001, all), whereas subgroup analysis revealed lower incidence of urinary retention and other complications in group III (P ≤ 0.031, all). Mean PROMs were significantly inferior in group II versus group III for VAS neck at 6 months (P = 0.030), Neck Disability Index at 6 months preoperatively (P ≤ 0.022, both), Short Form-12 Physical Composite Score at 12 weeks/2 years (P ≤ 0.047, both), and PROMIS-PF at 12 weeks/6 months (P ≤ 0.036, both). The MCID attainment rates were higher among group III for VAS neck/Neck Disability Index at 2 years (P ≤ 0.005) and overall achievement across all PROMs (P ≤ 0.015, all).

DISCUSSION

Increased ACDF case volume may lead to markedly decreased surgical time, blood loss, and length of postoperative stay as well as improved clinical outcomes in pain, disability, and physical function.

A Novel Scoring System to Predict Length of Stay After Anterior Cervical Discectomy and Fusion

INTRODUCTION

The movement toward reducing healthcare expenditures has led to an increased volume of outpatient anterior cervical diskectomy and fusions (ACDFs). Appropriateness for outpatient surgery can be gauged based on the duration of recovery each patient will likely need.

METHODS

Patients undergoing 1- or 2-level ACDFs were retrospectively identified at a single Level I spine surgery referral institution. Length of stay (LOS) was categorized binarily as either less than two midnights or two or more midnights. The data were split into training (80%) and test (20%) sets. Two multivariate regressions and three machine learning models were developed to predict a probability of LOS ≥ 2 based on preoperative patient characteristics. Using each model, coefficients were computed for each risk factor based on the training data set and used to create a calculatable ACDF Predictive Scoring System (APSS). Performance of each APSS was then evaluated on a subsample of the data set withheld from training. Decision curve analysis was done to evaluate benefit across probability thresholds for the best performing model.

RESULTS

In the final analysis, 1,516 patients had a LOS <2 and 643 had a LOS ≥2. Patient characteristics used for predictive modeling were American Society of Anesthesiologists score, age, body mass index, sex, procedure type, history of chronic pulmonary disease, depression, diabetes, hypertension, and hypothyroidism. The best performing APSS was modeled after a lasso regression. When applied to the withheld test data set, the APSS-lasso had an area under the curve from the receiver operating characteristic curve of 0.68, with a specificity of 0.78 and a sensitivity of 0.49. The calculated APSS scores ranged between 0 and 45 and corresponded to a probability of LOS ≥2 between 4% and 97%.

CONCLUSION

Using classic statistics and machine learning, this scoring system provides a platform for stratifying patients undergoing ACDF into an inpatient or outpatient surgical setting.

Comparison of the Safety of Outpatient Cervical Disc Replacement With Inpatient Cervical Disc Replacement: A Systematic Review and Meta-Analysis

STUDY DESIGN

A systematic review and meta-analysis.

OBJECTIVES

Outpatient cervical disc replacement (CDR) has been performed with an increasing trend in recent years. However, the safety profile surrounding outpatient CDR remains insufficient. The present study systematically reviewed the current studies about outpatient CDR and performed a meta-analysis to evaluate the current evidence on the safety of outpatient CDR as a comparison with the inpatient CDR.

METHODS

We searched the PubMed, Embase, Web of Science, and Cochrane Library databases comprehensively up to April 2020. Patient demographic data, overall complication, readmission, returning to the operation room, operating time were analyzed with the Stata 14 software and R 3.4.4 software.

RESULTS

Nine retrospective studies were included. Patients underwent outpatient CDR were significantly younger (mean difference [MD] = -1.97; 95% CI -3.80 to -0.15; P = .034) and had lower prevalence of hypertension (OR = 0.68; 95% CI 0.53-0.87; P = .002) compared with inpatient CDR. The pooled prevalence of overall complication was 0.51% (95% CI 0.10% to 1.13%) for outpatient CDR. Outpatient CDR had a 59% reduction in risk of developing complications (OR = 0.41; 95% CI 0.18-0.95; P = .037). Outpatient CDR showed significantly shorter operating time (MD = -18.37; 95% CI -25.96 to -10.77; P < .001). The readmission and reoperation rate were similar between the 2 groups.

CONCLUSIONS

There is a lack of prospective studies on the safety of outpatient CDR. However, current evidence shows outpatient CDR can be safely performed under careful patient selection. High-quality, large prospective studies are needed to demonstrate the generalizability of this study.

Multimodal Analgesic Management for Lumbar Decompression Surgery in the Ambulatory Setting: Clinical Case Series and Review of the Literature

BACKGROUND

Effective pain control is vital for successful surgery in the ambulatory setting. Our study aims to characterize a case series of patients who underwent lumbar decompression (LD) in the ambulatory surgical center (ASC) with the use of a multimodal analgesic (MMA) protocol.

METHODS

A prospective surgical registry was retrospectively assessed for patients who underwent single or multilevel LD in an ASC using MMA from 2013 to 2019. Observation in excess of 23 hours was not permitted at the ASC, and patients were required to be discharged the same day. Length of stay, patient-reported visual analog scale pain scores before discharge, and the quantity of narcotic medications administered to patients before discharge were recorded. Quantity of narcotic medications were converted into units of oral morphine equivalents and summed across all types of narcotic medications prescribed.

RESULTS

A total of 499 patients were included. In total, 86.0% (429) of the patients underwent a single-level decompression procedure, 13.8% (69) of patients underwent a 2-level, and 0.2% (1) of the patients underwent a 3-level procedure; 83.6% (417) of the patients in this study underwent a primary LD, and 14.0% (70) underwent a revision decompression.

CONCLUSIONS

This is the largest clinical case series focused on LD procedures within an ASC requiring no planned 23-hour observation. This study demonstrates the feasibility of performing LD surgery in an ASC with proper patient selection, surgical technique, and MMA protocol. All patients were discharged from the surgical center on the same day of surgery.

Perspective on morbidity and mortality of cervical surgery performed in outpatient/same day/ambulatory surgicenters versus inpatient facilities

Background:

This is an updated analysis of the morbidity and mortality of cervical surgery performed in outpatient/same day (OSD) (Postoperative care unit [PACU] observation 4–6 h), and ambulatory surgicenters (ASC: PACU 23 h) versus inpatient facilities (IF).

Methods:

We analyzed 19 predominantly level III (retrospective) and IV (case series) studies regarding the morbidity/mortality of cervical surgery performed in OSC/ASC versus IF.

Results:

A “selection bias” clearly favored operating on younger/healthier patients to undergo cervical surgery in OSD/ASC centers resulting in better outcomes. Alternatively, those selected for cervical procedures to be performed in IF classically demonstrated multiple major comorbidities (i.e. advanced age, diabetes, high body mass index, severe myelopathy, smoking, 3–4 level disease, and other comorbidities) and had poorer outcomes. Further, within the typical 4–6 h. PACU “observation window,” OSD facilities “picked up” most major postoperative complications, and typically showed 0% mortality rates. Nevertheless, the author’s review of 2 wrongful death suits (i.e. prior to 2018) arising from OSD ACDF cervical surgery demonstrated that there are probably many more mortalities occurring following discharges from OSD where cervical operations are being performed that are going underreported/unreported.

Conclusion:

“Selection bias” favors choosing younger/healthier patients to undergoing cervical surgery in OSD/ ASC facilities resulting in better outcomes. Atlernatively, choosing older patients with greater comorbidities for IF surgery correlated with poorer results. Although most OSD cervical series report 0% mortality rates, a review of 2 wrongful death suits by just one neurosurgeon prior to 2018 showed there are probably many more mortalities resulting from OSD cervical surgery than have been reported.

Identifying Best Practices for Managing Internal Carotid Artery Injury During Endoscopic Endonasal Surgery by Consensus of Expert Opinion

BACKGROUND

Injury to the internal carotid artery (ICA) is a potentially devastating complication of endoscopic endonasal surgery (EES) that as many as 20% of skull base surgeons will experience at least once during their careers. Managing these injuries is difficult given the small operative field and poor visibility created by high-flow hemorrhage, and, at present, there is no consensus regarding best practices.

OBJECTIVE

This study seeks to consolidate the practices and opinions of experienced skull base surgeons from high-volume tertiary care centers into a single consensus statement regarding the best practices for managing ICA injuries during EES.

METHODS

A panel of 23 skull base surgeons (15 neurosurgeons and 8 otolaryngologists) completed a 3-round Delphi survey that assessed experiences and opinions regarding various aspects of ICA injury management. Mean (SD) years since fellowship completion was 15.6 (8.1) and all but 3 surgeons had experienced an ICA injury at least once.

RESULTS

The final consensus statement included 36 guidelines all of which were grouped under 1 of 4 categories: 11 statements concerned preoperative management and equipment for high-risk patients; 14 statements concerned hemorrhage control; 4 statements concerned definitive management; 7 statements concerned pharmacologic treatment, blood pressure, and neurophysiologic monitoring.

CONCLUSIONS

There are numerous decisions that a surgeon must make when facing a carotid artery injury. In our estimation, many questions can be grouped under 1 of the 4 categories outlined in our consensus statement and can be addressed by these findings.

Bilateral cervical plexus block for anterior cervical spine surgery: study protocol for a randomised placebo-controlled trial

Background

There has been increasing focus to improve the quality of recovery following anterior cervical spine surgery (ACSS). Postoperative pain and nausea are the most common reasons for prolonged hospital stay and readmission after ACSS. Superficial cervical plexus block (SCPB) provides site-specific analgesia with minimal side effects, thereby improving the quality of recovery. The aim of our study was to investigate the effect bilateral cervical plexus block has on postoperative recovery in patients undergoing ACSS.

Methods

The study is a pragmatic, multi-centre, blinded, parallel-group, randomised placebo-controlled trial. 136 eligible patients (68 in each group) undergoing ACSS will be included. Patients randomised to the intervention group will have a SCPB administered under ultrasound guidance with a local anaesthetic solution (0.2% ropivacaine, 15mL); patients randomised to the placebo group will be injected in an identical manner with a saline solution. The primary outcome is the 40-item quality of recovery questionnaire score at 24 h after surgery. In addition, comparisons between groups will be made for a 24-h opioid usage and length of hospital stay. Neck pain intensity will be quantified using the numeric rating scale at 1, 3, 6 and at 24 h postoperatively. Incidence of nausea, vomiting, dysphagia or hoarseness in the first 24 h after surgery will also be measured.

Discussion

By conducting a blinded placebo trial, we aim to control for the bias inherently associated with a tangible medical intervention and show the true treatment effect of SCPB in ACSS. A statistically significant result will indicate an overall improved quality of recovery for patients; alternatively, if no benefit is shown, this trial will provide evidence that this intervention is unnecessary.

Trial registration

ClinicalTrials.gov ACTRN12619000028101. Prospectively registered on 11 January 2019 with Australia New Zealand Clinical Trials Registry

Multimodal Analgesic Management for Cervical Spine Surgery in the Ambulatory Setting

BACKGROUND

Patient selection and analgesic techniques, such as the multimodal analgesic (MMA) protocol, aid in ambulatory surgical center (ASC) cervical spine surgery. The purpose of this case series is to characterize patients undergoing anterior cervical discectomy and fusion (ACDF) and total cervical disc replacement (CDR) in an ASC with an enhanced MMA protocol.

METHODS

A prospectively maintained registry was retrospectively reviewed for cervical surgeries between May 2013 and August 2019. Inclusion criteria included ASC patients who underwent single-level or multilevel CDR or ACDF using an MMA protocol. Baseline, intraoperative, and postoperative characteristics were recorded, including length of stay, visual analog scale pain scores, neck disability index, complications, and narcotics administered.

RESULTS

A total of 178 patients met inclusion criteria with 125 single-level, 52 two-level, and 1 three-level procedure. Of those patients, 127 underwent ACDF and 51 underwent CDR. The longest procedure was 95 minutes and the mean length of stay was 6.1 hours, with 2 patients requiring hospital admission. All other patients were discharged within 10 hours. One of the admitted patients experienced a postoperative seizure that was later determined to be secondary to drug use and serotonin syndrome. The second patient developed an anterior cervical hematoma 5 hours postoperatively, which was immediately evacuated. The patient was admitted for observation and discharged the next day.

CONCLUSION

In our study, patients experienced considerable improvement in disability scores, with a low likelihood of postoperative complications. A safe and effective MMA protocol may help facilitate anterior cervical surgery in the outpatient setting.

LEVEL OF EVIDENCE

3.

CLINICAL RELEVANCE

Transitioning anterior cervical discectomy and fusions to the ASC requires an appropriate MMA protocol. Our findings reveal that an enhanced MMA protocol will help improve disability scores while keeping the likelihood of postoperative complications low. This supports the ASC setting for cervical spine procedures in appropriate patient populations.

Are outpatient three- and four-level anterior cervical discectomies and fusion safe?

BACKGROUND CONTEXT

The safety of outpatient one- and two-level anterior cervical discectomy and fusion (ACDF) has been validated in a number of recent studies. However, recent advancements in anesthetic and surgical technique have rendered procedures previously only performed in an inpatient setting, such as three- and four-level ACDF, potentially amenable to outpatient management.

PURPOSE

The present study aimed to investigate the safety of outpatient three- and four-level ACDF.

STUDY DESIGN

Retrospective cohort study PATIENT SAMPLE: The National Surgical Quality Improvement Program - a large, prospectively-collected registry - was queried to identify patients undergoing three- and four-level ACDF in an inpatient and outpatient setting.

OUTCOME MEASURES

The rates of total complications, perioperative blood transfusion, and unplanned hospital readmission in three- and four-level ACDF by inpatient or outpatient surgery status.

METHODS

Baseline patient characteristics and 30-day outcomes were tabulated and compared by inpatient or outpatient status using bivariate analysis. A multivariate analysis was also employed to adjust for differences in baseline patient characteristics when comparing outcomes, and was also used to identify independent predictors of complications and readmissions in patients undergoing three- and four-level ACDF.

RESULTS

In total 3,441 patients underwent three- or four-level ACDF, with 2,718 (79.0%) procedures occurring inpatient and 723 (21.0%) outpatient. Of patients undergoing outpatient ACDF, 596 patients (82.4%) underwent a three-level and 127 patients (17.6%) underwent four-level procedures. There was an increase in the utilization of outpatient procedures, increasing from 7.0% to 32.9% between 2011 and 2018. Patients undergoing outpatient surgery were younger, white, more likely to have three-level fusions (vs four-level), had a lower American Society of Anesthesiologists (ASA) classification, and were less likely to have a history of diabetes mellitus or dependent functional status. Among the inpatient and outpatient cohorts, there was no significant difference in the rates of total complications (4.49% vs 2.49%) or unplanned readmissions (4.96% vs 3.72%). Increasing age, operative duration, and ASA classification were independent predictors of complications and readmissions, however, inpatient or outpatient surgery status and number of levels fused was not.

CONCLUSIONS

This present study represents one of the largest cohorts of patients undergoing outpatient three- and four-level ACDF. Outpatient multilevel ACDF is performed in younger and healthier patients, with three-level procedures more commonly the four-level. There was no observed increased rates of total complications or readmissions in patients undergoing outpatient relative to inpatient surgery, however, we did identify increased age, operative duration, and ASA classification as independent predictors of these complications. Patient selection for outpatient procedures is of the highest importance, and future studies developing reproducible selection criteria are warranted.

Outpatient Minimally Invasive Lumbar Fusion Using Multimodal Analgesic Management in the Ambulatory Surgery Setting

BACKGROUND

The transition of minimally invasive (MIS) spine surgery from the inpatient to outpatient setting has been aided by advances in multimodal analgesic (MMA) protocols. This clinical case series of patients demonstrates the feasibility of ambulatory MIS transforaminal lumbar interbody fusion (TLIF) and lateral lumbar interbody fusion (LLIF) procedures while using an enhanced MMA protocol.

METHODS

Consecutive MIS TLIF or LLIF procedures with percutaneous pedicle screw fixation and direct decompression in the ambulatory setting were reviewed. The procedures were performed using an MMA protocol. The ambulatory surgery center (ASC) did not allow for observation of patients for periods of time greater than 23 hours. We recorded patient demographics, perioperative, and postoperative characteristics.

RESULTS

Fifty consecutive patients were identified from September 2016 to July 2019. Forty-one patients (82%) underwent MIS TLIF, and 9 patients underwent MIS LLIF (18.0%). All patients were discharged on the same day of surgery. The mean length of stay was 4.5 hours and 3.8 hours for the TLIF and LLIF cohorts, respectively. Our review of medical records revealed no postoperative complications following either the TLIF or the LLIF procedures.

CONCLUSIONS

The present study of 50 consecutive patients is the largest clinical series of ASC patients undergoing lumbar fusion procedures in a stand-alone facility with no extended postoperative observation capability. While using MMA protocol within the ASC, no postoperative complications were observed for either MIS TLIF or LLIF procedures. All patients were discharged from the ambulatory surgical center on the day of surgery with well-controlled postoperative pain.

LEVEL OF EVIDENCE

4.

CLINICAL RELEVANCE

The MMA protocol is an essential aspect in transitioning minimally invasive lumbar spine surgery to the ASC. Our findings indicate that MIS lumbar fusion spine surgery with an enhanced MMA protocol can lead to safe and timely ASC discharge while minimizing hospital admission.

Safety of Outpatient Anterior Cervical Discectomy and Fusion: A Systematic Review and Meta-Analysis

BACKGROUND

Anterior cervical discectomy and fusion (ACDF) is being increasingly offered on an outpatient basis. However, the safety profile of outpatient ACDF remains poorly defined.

OBJECTIVE

To review the medical literature on the safety of outpatient ACDF.

METHODS

We systematically reviewed the literature for articles published before April 1, 2018, describing outpatient ACDF and associated complications, including incidence of reoperation, stroke, thrombolytic events, dysphagia, hematoma, and mortality. A random-effects analysis was performed comparing complications between the inpatient and outpatient groups.

RESULTS

We identified 21 articles that satisfied the selection criteria, of which 15 were comparative studies. Most of the existing studies were retrospective, with a lack of level I or II studies on this topic. We found no statistically significant difference between inpatient and outpatient ACDF in overall complications, incidence of stroke, thrombolytic events, dysphagia, and hematoma development. However, patients undergoing outpatient ACDF had lower reported reoperation rates (P < .001), mortality (P < .001), and hospitalization duration (P < .001).

CONCLUSION

Our meta-analysis indicates that there is a lack of high level of evidence studies regarding the safety of outpatient ACDF. However, the existing literature suggests that outpatient ACDF can be safe, with low complication rates comparable to inpatient ACDF in well-selected patients. Patients with advanced age and comorbidities such as obesity and significant myelopathy are likely not suitable for outpatient ACDF. Spine surgeons must carefully evaluate each patient to decide whether outpatient ACDF is a safe option. Higher quality, large prospective randomized control trials are needed to accurately demonstrate the safety profile of outpatient ACDF.

Finnish Trial on Practices of Anterior Cervical Decompression and Fusion (FACADE): a protocol for a prospective randomised non-inferiority trial comparing outpatient versus inpatient care

INTRODUCTION

Although a great majority of patients with cervical radiculopathy syndrome can successfully be treated non-operatively, a considerable proportion experience persistent symptoms, severe enough to require neurosurgical intervention. During the past decade, cervical spine procedures have increasingly been performed on an outpatient basis and retrospective database analyses have shown this to be feasible and safe. However, there are no randomised controlled studies comparing outpatient care with inpatient care, particularly with emphasis on the patients' perception of symptom relief and their ability to return to normal daily activities and work.

METHODS AND ANALYSIS

This is a prospective, randomised, controlled, parallel group non-inferiority trial comparing the traditional hospital surveillance (inpatient, patients staying in the hospital for 1-3 nights after surgery) with outpatient care (discharge on the day of the surgery, usually within 6-8 hours after procedure) in patients who have undergone anterior cervical decompression and fusion procedure. To determine whether early discharge (outpatient care) is non-inferior to inpatient care, we will randomise 104 patients to these two groups and follow them for 6 months using the Neck Disability Index (NDI) as the primary outcome. We expect that early discharge is not significantly worse than the current care in terms of change in NDI. Non-inferiority will be declared if the mean improvement for outpatient care is no worse than the mean improvement for inpatient care, by a margin of 17.3%. We hypothesise that a shorter hospital stay results in more rapid return to normal daily activities, shorter duration of sick leave and decreased secondary costs to healthcare system. Secondary outcomes in our study are arm pain and neck pain using the Numeric Rating Scale, operative success (Odom's criteria), patient's satisfaction to treatment, general quality of life (EQ-5D-5L), Work Ability Score, sickness absence days, return to previous leisure activities and complications.

ETHICS AND DISSEMINATION

The study was approved by the institutional review board of the Helsinki and Uusimaa Hospital District on 6 June 2019 (1540/2019) and duly registered at ClinicalTrials.gov. We will disseminate the findings of this study through peer-reviewed publications and conference presentations.

TRIAL REGISTRATION NUMBER

NCT03979443.

Same-Day Anterior Cervical Discectomy and Fusion-Our Protocol and Experience: Same-Day Discharge After Anterior Cervical Discectomy and Fusion in Suitable Patients has Similarly Low Readmission Rates as Admitted Patients

Background

Outpatient anterior cervical discectomy and fusion (ACDF) is performed frequently, with studies demonstrating similar complication and readmission rates compared to traditional admission. Advantages include cost effectiveness, as well as lower risk of nosocomial infections and medical errors, which lead to quicker recovery and higher patient satisfaction. Protocols are needed to ensure that outpatient ACDF occurs safely. The objective of this study was to develop and implement a protocol with patient selection and discharge criteria for patients undergoing same-day discharge (SDD) ACDF and assess readmission rates.

Methods

A retrospective chart review was performed to identify patients undergoing 1 or 2 level primary ACDF between March 2016 and March 2017 who were eligible for SDD according to the institutional protocol (Figure 1, Table 2). Patients with identical surgery and discharge dates were grouped as SDD, and admitted patients were grouped as same-day admission (SDA). Using our electronic health record's analytics, readmissions in the 90-day postoperative period were identified.

Results

Of the 434 patients identified, 126 patients were SDD, and 308 were SDA. Baseline characteristics such as age, operative time, and time in the recovery room were significantly different between the 2 groups (Table 2). The average length of stay of admitted patients was 1.48 days, with 77% discharged on postoperative day 1. There was an overall, noninferior readmission rate of 0.8% in the SDD group compared to 0.6% in the SDA group (P = .86).

Conclusions

The results of this study support the feasibility of outpatient ACDF and add a patient selection and discharge criteria to the literature. Proper identification of suitable patients using our protocol results in a noninferior readmission rate, allowing surgeons to continue to safely perform these surgeries with a low readmission rate.

Level of Evidence

3.

Clinical Relevance

SDD is safe in the appropriate patient population.

Spine centers of excellence: applications for the ambulatory care setting

Centers of excellence (COE) are designed to deliver high-quality, cost-effective healthcare by providing specialized and comprehensive multidisciplinary care for a given condition and have become attractive option to both insurers and healthcare providers given their promise of creating value. The criteria that constitute and define a COE may be delineated by a number of entities with a stake in value-based healthcare delivery including professional societies, the federal government, insurers and businesses seeking to control costs while guaranteeing outcomes for their employees. COEs accomplish this goal through a number of means, the first and most essential of which is centralization of organization wherein a variety of specialists are integrated under a single hospital system to improve communication between providers and decrease overall variability of care delivery. In this system, the patient is tracked throughout the entire spectrum of care from diagnosis, through non-operative or surgical intervention, and postoperative care. The centralized model in turn allows for standardization of protocols and multidisciplinary team input which helps to inform case selection, improve patient screening, make treatment more uniform and ultimately allow for dynamic and continual modification of best practices. This model lends itself particularly well to orthopedic subspecialties where patients often require specialized pre-, intra- and post-operative care from a variety of providers. However, despite their apparent benefits, studies evaluating outcomes after implementation of COEs have been less than favorable, and further research is needed in this area to support their widespread adoption. The growth of the ambulatory surgery center in orthopedics provides a new opportunity for the development, evaluation and evolution of spine COEs. Although the direct value of COEs is yet to be firmly established, they provide guidelines for best practices in outpatient spine surgery and a framework for how spine care can be transitioned safely and effectively to the outpatient setting.

Complication avoidance and management in ambulatory spine surgery

The positive safety profile and potential cost savings associated with ambulatory spine surgery have resulted in an increasing number of spine procedures being performed on an outpatient basis. As indications become more inclusive and the variety and volume of ambulatory procedures grow, the incidence of complications may rise. Limiting adverse events in the outpatient setting starts with patient selection. Surgeons should be aware of the potential complications and associated risk factors for common ambulatory spine procedures and employ strategies to limit and appropriately manage them. Protocols which include patient education, multimodal anesthesia and analgesia, standardized post-operative monitoring, and safe discharge planning are also essential for maximizing safety in the ambulatory setting.

Retrospective single-centre series of 1300 consecutive cases of outpatient cervical spine surgery: complications, hospital readmissions, and reoperations

Background: Outpatient surgery is becoming more common and is more cost-effective than inpatient surgery. Nonetheless, many surgeons and health care administrators are still hesitant to accept outpatient surgery for cervical degenerative spinal disease (C-DSD). This study assesses the types and rates of complications, hospital admissions, and reoperations after outpatient surgery of C-DSD.Methods: Complications, hospital admissions within 90 days of surgery, and reoperations within one year of surgery were recorded retrospectively in 1300 outpatients undergoing microsurgical decompression for C-DSD at the Oslofjord Clinic from 2008 to 2017. The surgical procedures performed were anterior cervical decompression and fusion (ACDF) in 1083 patients and posterior cervical foraminotomy in 217 patients.Results: The surgical mortality rate was 0%. Sixteen major complications were recorded in 15/1300 (1.2%) patients. The complications were neurological deterioration in four patients, postoperative hematoma in two, dural lesions with cerebrospinal fluid leakage in one, deep surgical-site infection in one, persistent hoarseness in three, and persistent dysphagia in five. The two potentially life-threatening hematomas were detected within the planned six-hour observation period. Two (0.2%) patients were admitted to hospital within hours of surgery completion with stroke-like signs and symptoms, and four (0.3%) patients were admitted to hospital within 90 days due to surgery-related events. The rate of reoperations for cervical radiculopathy within 12 months was 25/1171 (2%); eight patients' reoperations were due to inadequate primary decompression, one was due to recurrent disc herniation at the same level and side, and 16 were due to new-onset radiculopathy from an adjacent level or other side.Conclusions: Outpatient microsurgical decompression of the degenerative cervical spine in carefully selected patients appears to be safe and carries a low major complication rate, low hospital admission rate, and low one-year reoperation rate.

Analysis of Outcomes and Cost of Inpatient and Ambulatory Anterior Cervical Disk Replacement Using a State-level Database

BACKGROUND

Outpatient cervical artificial disk replacement (ADR) is a promising candidate for cost reduction. Several studies have demonstrated low overall complications and minimal readmission in anterior cervical procedures.

OBJECTIVE

The objective of this study was to compare clinical outcomes and cost associated between inpatient and ambulatory setting ADR.

MATERIALS AND METHODS

Outcomes and cost were retrospectively analyzed for patients undergoing elective ADR in California, Florida, and New York from 2009 to 2011 in State Inpatient and Ambulatory Databases.

RESULTS

A total of 1789 index ADR procedures were identified in the inpatient database (State Inpatient Databases) compared with 370 procedures in the ambulatory cohort (State Ambulatory Surgery and Services Databases). Ambulatory patients presented to the emergency department 19 times (5.14%) within 30 days of the index procedure compared with 4.2% of inpatients. Four unique patients underwent readmission within 30 days in the ambulatory ADR cohort (1% total) compared with 2.2% in the inpatient ADR group. No ambulatory ADR patients underwent a reoperation within 30 days. Of the inpatient ADR group, 6 unique patients underwent reoperation within 30 days (0.34%, Charlson Comorbidity Index zero=0.28%, Charlson Comorbidity Index>0=0.6%). There was no significant difference in emergency department visit rate, inpatient readmission rate, or reoperation rates within 30 days of the index procedure between outpatient or inpatient ADR. Outpatient ADR is noninferior to inpatient ADR in all clinical outcomes. The direct cost was significantly lower in the outpatient ADR group ($11,059 vs. 17,033; P<0.001). The 90-day cumulative charges were significantly lower in the outpatient ADR group (mean $46,404.03 vs. $80,055; P<0.0001).

CONCLUSIONS

ADR can be performed in an ambulatory setting with comparable morbidity, readmission rates, and lower costs, to inpatient ADR.

Current trends in ambulatory spine surgery: a systematic review

Spine surgery continues to move into the ambulatory setting in an effort to pair high-quality care delivery with low-cost facilities. The purpose of this review was to assess the current literature for trends in the practice of ambulatory spine surgery. A systematic review of the English language literature from the past five years was performed utilizing PRISMA standards. The results demonstrate that current focus of research emphasizes the safety of ambulatory surgery-with several studies commenting on complication rates, patient selection, and postoperative protocols to prevent readmissions or complications. Research is also focused on quality of care, and ensuring non-inferiority of ambulatory surgery when compared with traditional inpatient hospitalizations. Importantly, no level I or II literature has been published on the topic in the past five years, suggesting a renewed need for high quality prospective studies.

Future endeavors in ambulatory spine surgery

Due to the high societal and financial burden of spinal disorders, spine surgery is thought to be one of the most impactful targets for healthcare cost reduction. One avenue for cost-reduction that is increasingly being explored not just in spine surgery but across specialties is the performance of surgeries in ambulatory surgery centers (ASCs). Despite potential cost-savings, the utilization of ASCs for spine surgery remains largely limited to high-volume centers in the US, and predominantly for single- or two-level lumbar microdiscectomy and anterior cervical discectomy and fusion (ACDF) procedures. Factors most commonly cited for the lack of wider adoption include the risk of life-threatening complications, paucity of guidelines, and limited accessibility of these procedures to various patient populations. Thus, the future growth and adoption of ambulatory spine surgery depends on addressing these concerns by developing evidence-based guidelines for patient- and procedure selection, creating risk-stratification tools, devising appropriate discharge recommendations, and optimizing care protocols to ensure that safety, efficacy and outcomes are maintained. Other avenues that may allow for more widespread use of ASCs include the use of electronic health tools for post-operative monitoring after discharge from the ASC, increasing accessibility of ambulatory procedures to eligible populations, and identifying systemic inefficiencies and implementing process-improvement measures to optimize patient-selection, scheduling and peri-operative management. The success of ambulatory surgery ultimately depends not only on the surgical procedure, but also on its organization upstream and downstream. It provides an exciting and burgeoning avenue for innovation, cost-reduction and value-creation.

Lumbar spinal fusion in the outpatient setting: an update on management, surgical approaches and planning

Outpatient lumbar spinal fusion surgery has the potential for improved patient satisfaction, speed of recovery, and economic advantages when compared to inpatient surgery. Despite the rise in the number of these procedures performed annually, the literature on this topic remains scarce. As such, there is a need for a comprehensive review of current concepts in indications and management. The current review will present the most recent literature regarding pre-operative, intra-operative, and post-operative considerations when performing outpatient lumbar spinal fusion surgery.

Outpatient Posterior Lumbar Fusion: A Population-Based Analysis of Trends and Complication Rates

STUDY DESIGN

A retrospective case-control study.

OBJECTIVE

The aim of this study was to determine the nationwide trends and complication rates associated with outpatient posterior lumbar fusion (PLF).

SUMMARY OF BACKGROUND DATA

Outpatient lumbar spine fusion is now possible secondary to minimally invasive techniques that allow for reduced hospital stays and analgesic requirements. Limited data are currently available regarding the clinical outcome of outpatient lumbar fusion.

METHODS

The Humana administrative claims database was queried for patients who underwent one to two-level PLF (CPT-22612 or CPT-22633 AND ICD-9-816.2) as either outpatients or inpatients from Q1 2007 to Q2 2015. The incidence of perioperative medical and surgical complications was determined by querying for relevant International Classification of Diseases and Current Procedural Terminology codes. Multivariate logistic regression adjusting for age, gender, and Charlson Comorbidity Index was used to calculate odds ratios (ORs) of complications among outpatients relative to inpatients undergoing PLF.

RESULTS

Cohorts of 770 patients who underwent outpatient PLF and 26,826 patients who underwent inpatient PLF were identified. The median age was in the 65 to 69 years age group for both cohorts. The annual relative incidence of outpatient PLF remained stable across the study period (R = 0.03, P = 0.646). Adjusting for age, gender, and comorbidities, patients undergoing outpatient PLF had higher likelihood of revision/extension of posterior fusion [(OR 2.33, confidence interval (CI) 2.06-2.63, P < 0.001], anterior fusion (OR 1.64, CI 1.31-2.04, P < 0.001), and decompressive laminectomy (OR 2.01, CI 1.74-2.33, P < 0.001) within 1 year. Risk-adjusted rates of all other postoperative surgical and medical complications were statistically comparable.

CONCLUSION

Outpatient lumbar fusion is uncommonly performed in the United States. Data collected from a national private insurance database demonstrate a greater risk of postoperative surgical complications including revision anterior and posterior fusion and decompressive laminectomy. Surgeons should be cautious in performing PLF in the outpatient setting, as the risk of revision surgery may increase in these cases.

LEVEL OF EVIDENCE

3.

Ambulatory anterior cervical discectomy and fusion is associated with a higher risk of revision surgery and perioperative complications: an analysis of a large nationwide database

BACKGROUND CONTEXT

With the changing landscape of health care, outpatient spine surgery is being more commonly performed to reduce cost and to improve efficiency. Anterior cervical discectomy and fusion (ACDF) is one of the most common spine surgeries performed and demand is expected to increase with an aging population.

PURPOSE

The objective of this study was to determine the nationwide trends and relative complication rates associated with outpatient ACDF.

STUDY DESIGN/SETTING

This is a large-scale retrospective case control study.

PATIENT SAMPLE

The patient sample included Humana-insured patients who underwent one- to two-level ACDF as either outpatients or inpatients from 2011 to 2016 OUTCOME MEASURES: The outcome measures included incidence and the adjusted odds ratio (OR) of postoperative medical and surgical complications within 1 year of the index surgery.

MATERIALS AND METHODS

A retrospective review was performed of the PearlDiver Humana insurance records database to identify patients undergoing one- to two-level ACDF (Current Procedural Terminology [CPT]-22551 and International Classification of Diseases [ICD]-9-816.2) as either outpatients or inpatients from 2011 to 2016. The incidence of perioperative medical and surgical complications was determined by querying for relevant ICD and CPT codes. Multivariate logistic regression adjusting for age, gender, and Charlson Comorbidity Index was used to calculate ORs of complications among outpatients relative to inpatients undergoing ACDF.

RESULTS

Cohorts of 1,215 patients who underwent outpatient ACDF and 10,964 patients who underwent inpatient ACDF were identified. The median age was in the 65-69 age group for both cohorts. The annual relative incidence of outpatient ACDF increased from 0.11 in 2011 to 0.22 in 2016 (R²=0.82, p=.04). Adjusting for age, gender, and comorbidities, patients undergoing outpatient ACDF were more likely to undergo revision surgery for posterior fusion at both 6 months (OR 1.58, confidence interval [CI] 1.27-1.96, p<.001) and 1 year (OR 1.79, CI 1.51-2.13, p<.001) postoperatively. Outpatient ACDF was also associated with a higher likelihood of revision anterior fusion at 1 year postoperatively (OR 1.46, CI 1.26-1.70, p<.001). Among medical complications, postoperative acute renal failure was more frequently associated with outpatient ACDF than inpatient ACDF (OR 1.25, CI 1.06-1.49, p=.010). Adjusted rates of all other queried surgical and medical complications were comparable.

CONCLUSIONS

Outpatient ACDF is increasing in frequency nationwide over the past several years. Nationwide data demonstrate a greater risk of perioperative surgical complications, including revision anterior and posterior fusion, as well as a higher risk of postoperative acute renal failure. Candidates for outpatient ACDF should be counseled and carefully selected to reduce these risks.