A Comparison of 30-Day Hospital Readmission and Complication Rates After Outpatient Versus Inpatient 1 and 2 Level Anterior Cervical Discectomy and Fusion Surgery: An Analysis of a Medicare Patient Sample

Growing utilization of ambulatory spine surgery in Medicare patients from 2010-2021

Background

There is growing interest in transitioning various surgical procedures to the outpatient care setting. However, for Medicare patients, the site of service for surgical procedures is influenced by regulations within the Inpatient and Outpatient Prospective Payment Systems. The purpose of this study is to quantify changes in utilization of outpatient spine surgery within the Medicare population, as well as to determine changes in outpatient volume after removal of a procedure from the "inpatient-only" list.

Methods

This is a cross-sectional study of Medicare billing database information for selected spine procedures included in the Medicare Physician/Supplier Procedure Summary (PSPS) public use files from 2010-2021. These files include aggregated data from Medicare Part B fee-for-service claims, published yearly. Procedures from Healthcare Common Procedural Coding System (HCPCS) code ranges 22010-22899 and 62380-63103 were selected for analysis, limited to surgical services delivered in the inpatient, hospital outpatient department (HOPD), and ambulatory surgical center (ASC) settings. For each HCPCS code included, estimates of the total number of services and corresponding changes in volume were calculated.

Results

Within the range of codes included in the study, the total number of outpatient spine procedures rose approximately 193% from 2010 to 2021, with compound annual growth rate (CAGR) for outpatient procedures per year of 9.9% for HOPDs and 15.7% for ASCs (-2.2% for inpatient procedures). Within this period, the ASC list grew from 12 procedures to 58 procedures. In 2021, the highest volume ASC procedure was HCPCS 63047, at approximately 4970 procedures.

Conclusions

This study demonstrates a trend of increasing utilization of HOPDs and ASCs for spine procedures among Medicare beneficiaries from 2010 to 2021. Though HOPDs are currently more widely utilized, the ongoing additions of spine procedures to the ASC covered procedures list may shift this balance.

Is Complete Correction of Cervical Sagittal Malalignment Necessary During 4-Level Anterior Cervical Discectomy and Fusion Surgery in Patients With Kyphosis?

STUDY DESIGN

Retrospective analysis.

OBJECTIVE

We investigated whether complete correction of cervical sagittal malalignment is necessary during 4-level anterior cervical discectomy and fusion (ACDF) in patients with kyphosis.

METHODS

This retrospective study included 84 patients who underwent 4-level ACDF surgery at a university hospital between January 2010 and December 2015. Based on the degree of cervical lordosis correction, patients were categorized into the following groups: mild (0-10°), moderate (10-20°), and complete correction (>20°). The clinical outcomes, radiological parameters, and functional outcomes were analyzed.

RESULTS

We observed no significant intergroup differences in the baseline characteristics. The cervical sagittal vertical axis (CSVA) correction loss at the final follow-up was lesser in the mild- and moderate- than in the complete-correction group. The spinocranial angle (SCA) and T1 slope (T1 S) were significantly higher in the moderate- and complete-correction groups than in the mild-correction group, 3 days postoperatively. The cervical proximal junctional kyphosis (CPJK), adjacent segment degeneration (ASD), and ASD following CPJK rates were higher in the complete-correction group. We observed no significant intergroup differences in postoperative complications; however, 5 patients showed internal fixation failure in the complete-correction group; 4 of these patients required reoperation. No significant intergroup difference was observed in the Japanese Orthopedic Association and neck disability index scores at any time point.

CONCLUSIONS

A mild-to-moderate correction of cervical lordosis is superior to complete correction in patients with kyphosis who undergo 4-level ACDF because this approach is associated with lesser axial stress and CSVA correction loss.

Inpatient Versus Outpatient Surgery: A Comparison of Postoperative Mortality and Morbidity in Elective Operations

BACKGROUND

Operations performed outpatient offer several benefits. The prevalence of outpatient operations is growing. Consequently, the proportion of patients with multiple comorbidities undergoing outpatient surgery is increasing. We compared 30-day mortality and overall morbidity between outpatient and inpatient elective operations.

METHODS

Using the 2005-2018 ACS-NSQIP database, we evaluated trends in percent of hospital outpatient operations performed over time, and the percent of operations done outpatient versus inpatient by CPT code. Patient characteristics were compared for outpatient versus inpatient operations. We compared unadjusted and risk-adjusted 30-day mortality and morbidity for inpatient and outpatient operations.

RESULTS

A total of 6,494,298 patients were included. The proportion of outpatient operations increased over time, from 37.8% in 2005 to 48.2% in 2018. We analyzed the 50 most frequent operations performed outpatient versus inpatient 25-75% of the time (n = 1,743,097). Patients having outpatient operations were younger (51.6 vs 54.6 years), female (70.3% vs 67.3%), had fewer comorbidities, and lower ASA class (I-II, 69.3% vs. 59.9%). On both unadjusted and risk-adjusted analysis, 30-day mortality and overall morbidity were less likely in outpatient versus inpatient operations.

CONCLUSION

In this large multi-specialty analysis, we found that patients undergoing outpatient surgery had lower risk of 30-day morbidity and mortality than those undergoing the same inpatient operation. Patients having outpatient surgery were generally healthier, suggesting careful patient selection occurred even with increasing outpatient operation frequency. Patients and providers can feel reassured that outpatient operations are a safe, reasonable option for selected patients.

Choose Wisely: Surgical Selection of Candidates for Outpatient Anterior Cervical Surgery Based on Early Complications Among Inpatients

BACKGROUND

Anterior cervical discectomy and fusion (ACDF) and cervical disc arthroplasty (CDA) are attractive targets for transition to the outpatient setting. We assessed the prevalence of rapid responses and major complications in the inpatient setting following 1 or 2-level ACDFs and CDAs. We evaluated factors that may place patients at greater risk for a rapid response or a postoperative complication.

METHODS

This was an institutional review board-approved, retrospective cohort study of adults undergoing 1 or 2-level ACDF or CDA at 1 hospital over a 2-year period (2018 and 2019). Data on patient demographic characteristics, surgical procedures, and comorbidities were collected. Rapid response events were identified by hospital floor staff and involved acute changes in a patient's clinical condition. Complications were events that were life-threatening, required an intervention, or led to delayed hospital discharge.

RESULTS

In this study, 1,040 patients were included: 888 underwent ACDF and 152 underwent CDA. Thirty-six patients (3.5%) experienced a rapid response event; 22% occurred >24 hours after extubation. Patients having a rapid response event had a significantly higher risk of developing a complication (risk ratio, 10; p < 0.01) and had a significantly longer hospital stay. Twenty-four patients (2.3%) experienced acute complications; 71% occurred >6 hours after extubation. Patients with a complication were older and more likely to be current or former smokers, have chronic obstructive pulmonary disease, have asthma, and have an American Society of Anesthesiologists (ASA) score of >2. The length of the surgical procedure was significantly longer in patients who developed a complication. All patients who developed dysphagia had a surgical procedure involving C4-C5 or more cephalad. Patients with a rapid response event or complication were more commonly undergoing revision surgical procedures.

CONCLUSIONS

Rapid response and complications are uncommon following 1 or 2-level ACDFs or CDAs but portend a longer hospital stay and increased morbidity. Revision surgical procedures place patients at higher risk for rapid responses and complications. Additionally, older patients, patients with chronic obstructive pulmonary disease or asthma, patients who are current or former smokers, and patients who have an ASA score of ≥3 are at increased risk for postoperative complications.

LEVEL OF EVIDENCE

Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

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.

Outcomes following outpatient anterior cervical discectomy and fusion for the treatment of myelopathy

INTRODUCTION

Anterior cervical discectomy and fusion (ACDF) is a commonly performed procedure for the treatment of degenerative cervical disease. With continued increase in U.S. healthcare expenditure, surgeons have begun to more closely examine the benefits of performing ACDF in an outpatient setting to increase efficiency, reduce the overall financial burden on patients/providers, and provide streamlined care for these patients. The purpose of this study was to analyze outcomes following outpatient ACDF for the treatment of myelopathy.

METHODS

14,490 patients who had undergone ACDF for myelopathy from 2010 to 2018 were included in this retrospective study, of which 2956 (20.40%) patients were considered to have undergone outpatient surgery. Pearson chi-squared tests and Fischer's Exact Tests were used to analyze differences in categorical variables of demographics, preoperative comorbidities, and postoperative complications, while Mann-Whitney-U-Tests were used to compare mean values of continuous variables. Coarsened-exact-matching (CEM) was implemented to control for baseline differences in demographics and comorbidities, and post-matching diagnostics included multivariate and univariate imbalance measure assessment. Outcomes were compared between the CEM-matched inpatient and outpatients ACDF cohorts.

RESULTS

Upon CEM-matching (L1-statistic <0.001), the outpatient cohort (n = 2610, 25.13%) demonstrated significantly lower rates of any complication (p < 0.001), minor complications (p = 0.001), urinary tract infections (p = 0.029), blood transfusions (p < 0.001), major complications (p < 0.001), deep incisional surgical site infections (p = 0.017), ventilator dependence (p = 0.027), cardiac arrest (p = 0.028), unplanned reoperations (p = 0.001), and mortality (p = 0.006) in the 30-day postoperative period when compared to inpatient controls (n = 7774, 74.87%).

CONCLUSION

ACDF has been a target amongst spinal procedures as a prime candidate for outpatient surgery. However, no previous reports have described complication rates and perioperative parameters in the sub-population of outpatient ACDF patients with myelopathy. In addition to shorter times from admission to operating room, operative time, and LOS, our study also demonstrated lower rates of major and overall complications in outpatient ACDF's for myelopathy in comparison to their inpatient counterparts. Performing ACDF's for myelopathy in an outpatient setting may help to curb costs, improve outcomes, and serve as a valuable learning resource for graduate medical education with rapid turnovers and shorter operative times.

Trends in National Use of Anterior Cervical Discectomy and Fusion from 2006 to 2016

OBJECTIVE

Anterior cervical discectomy and fusion (ACDF) is the most common procedure for the treatment of degenerative cervical conditions. The objective of this study is to determine time-dependent trends in patient outcomes following ACDF for degenerative disease from 2006 to 2016.

METHODS

We used the National Surgical Quality Improvement Program (NSQIP) database to retrospectively review all patients who underwent elective ACDF between 2006 and 2016. A descriptive statistical analysis followed by time trend analysis was performed on demographics, comorbidities, perioperative, and outcome variables. Primary outcomes were reoperation and readmission rates. Secondary outcomes were medical and surgical complications reported within 30 days of operation.

RESULTS

A total of 36,854 patients underwent elective ACDF from the 2006 to 2016 NSQIP database. Mean age increased from 48.19 years [standard error: 1.49] in 2006 to 54.08 years [standard error: 0.12] in 2016 (P < 0.001). There was a significantly greater number of outpatient procedures from 2012 to 2016 (P < 0.001). The proportion of patients with American Society of Anesthesiologists classes 3/4 significantly increased over time (P < 0.001, P < 0.001, P = 0.005, respectively). Readmission risk, first documented in NSQIP in 2011, increased over time from 2011 to 2016 (P < 0.001). Unplanned reoperations have remained consistent at about 1.4%. Postoperative complications varied over time with no discernable patterns or trends.

CONCLUSIONS

Since the establishment of the NSQIP database, there have been no considerable improvements in reoperation or postoperative complication rates based on available data, however, there have been increased rates of readmission. Changes in data collection and an aging patient population with greater burden of comorbidities could confound these trends.