Outpatient Spine Surgery: Defining the Outcomes, Value, and Barriers to Implementation

Arjun Vivek Pendharkar, MD; Maryam Nour Shahin, BS; Allen Lin Ho, MD; Eric Scott Sussman, MD; David Arnold Purger, MD, PhD; Anand Veeravagu, MD; John Kevin Ratliff, MD; Atman Mukesh Desai, MD


Neurosurg Focus. 2018;44(5):e11 

In This Article


Lumbar Laminectomy and Discectomy

Lumbar laminectomy with or without discectomy remains the most common spine operation performed in the United States and was one of the earliest procedures to be successfully transitioned to the outpatient setting (Table 1). Several groups have reported clinical series describing favorable outcomes.[8,10,22,25,33,47] Helseth et al. reported on a series of 1073 consecutive patients undergoing lumbar procedures at a freestanding neurosurgical clinic with a successful discharge rate of 99.8% on the day of surgery.[19] No patients died within 30 days, and the 90-day readmission rate was 1.5%. Nine patients (0.6%) suffered a postoperative hematoma, which was recognized and evacuated postoperatively, and these patients were subsequently discharged the same day. Notably, this study was conducted in Oslo, Norway, in a health care ecosystem distinct from that of the United States. Another group of investigators studied 212 consecutive patients in the United States, who had undergone a first operation for lumbar disease; the authors reported the overall success rate at 2 years as 75%–80%, as defined by the visual analog scale and Oswestry Disability Index.[4] In their cohort, the average hospital stay was 5 hours, and only 1 patient (0.5%) was admitted to the inpatient service following surgery. Best and Sasso analyzed outcomes for 233 consecutive patients 65 years of age or older who underwent outpatient lumbar decompression, finding an inpatient admission conversion rate of 4.1% and an overall complication rate of 7.1%.[8] In addition to single-center cohort studies, the overall trends and outcomes for lumbar laminectomy and discectomy have been analyzed using large surgical databases. Pugely and colleagues performed a propensity score–matched analysis of 4310 lumbar discectomy cases in the American College of Surgeons database.[34] Interestingly, in the matched cohort, the inpatient group had a significantly higher rate of complications (OR 1.521) even after adjusting for potential confounders. Moreover, an advanced age, diabetes, and operative times longer than 150 minutes were independent predictors of a postoperative complication. All data taken together, lumbar decompression has the strongest evidence for safety in the outpatient setting.

Lumbar Fusion

The literature regarding lumbar fusion in the outpatient setting is more limited than that regarding decompression with or without discectomy (Table 2). Conceptually, as minimally invasive fusion techniques continue to evolve, this is a promising group of operations to transition to outpatient procedures. Several smaller cohort studies have reported favorable outcomes from minimally invasive transforaminal lumbar interbody fusion and posterior fusion performed in the outpatient setting.[16] One technical modification to posterior fusion includes the use of midline cortical bone trajectory pedicle screws to reduce the amount of muscle dissection and tissue destruction without sacrificing fusion rates.[12] Another promising avenue involves the use of lateral fusion techniques, which may also reduce postoperative pain and thus enable earlier discharge. Smith et al. performed a retrospective analysis of 1033 patients treated with minimally invasive lateral interbody fusion and grouped patients according to length of stay.[39] They found that a younger age, lower body mass index, less advanced disease, and higher preoperative hemoglobin levels were predictive factors for discharge within 24 hours. In the prospective arm, the authors performed 54 lateral and 18 posterior fusions in an ambulatory setting with no transfers to an inpatient facility. Two additional patients (3.7%) visited the emergency department within 30 days. Another author group prospectively compared 70 consecutive patients undergoing lateral fusion in either an inpatient or outpatient setting.[11] There were no significant baseline differences in characteristics between the two cohorts, including age, body mass index, or pathological level treated. Additionally, fusion was achieved in all patients. Between the two groups, the outpatient cohort benefited from significant improvement in the Oswestry Disability Index, less blood loss, and shorter operative time. Overall, these studies suggest that for young, healthy patients, a lateral fusion may be well tolerated with same-day discharge. However, the overall reported readmission rates tended to be higher than those in the lumbar decompression and/or discectomy literature.

Anterior Cervical Discectomy and Fusion

There is a growing body of evidence in support of anterior cervical discectomy and fusion (ACDF) performed in the outpatient setting (Table 3). However, unlike in lumbar surgery, the specter of neck hematoma and airway compromise creates an additional barrier to changes in practice.

The first reports of outpatient ACDF were small, single-surgeon feasibility studies reporting on fewer than 100 patients undergoing 1- or 2-level surgery with same-day discharge.[38,40,42,43] There were no reported deaths, and overall complication rates ranged from 0% to 2%. In these reports, only 1 patient required conversion to inpatient status for neck swelling and this patient did not require reoperation. The initial studies provided proof of concept but were limited by a lack of statistical power to show a difference between inpatient and outpatient ACDF. More recently, there have been several larger clinical series and database studies reporting direct comparisons of inpatient and outpatient ACDF. McGirt et al. obtained 1442 ACDF cases (650 inpatients, 792 outpatients) from the American College of Surgeons database, and after propensity matching for 32 covariates such as number of levels, medical comorbidities, age, and sex, these authors found that outpatient ACDF had 58% reduced odds of a major morbidity and 80% lower odds of reoperation within 30 days (ORs 0.42 and 0.20, respectively).[29] The same author group analyzed 1000 consecutive ACDF patients, all of whom had been observed for at least 4 hours prior to discharge.[1] Notably, all of the patients had American Society of Anesthesiologists physical status class I or II, all underwent 1- or 2-level ACDF, and all cases began before noon. Overall, 8 patients (0.08%) were transferred to inpatient status. There were no significant differences between the inpatient and outpatient cohort in the 30- and 90-day readmission or reoperation rate. Several other surgical database studies have since corroborated these findings in support of outpatient 1- or 2-level ACDF with an overall low comorbidity profile.[17,24,35] Additionally, Ban and colleagues performed a meta-analysis and systematic review, including 12 articles and 1693 treated levels, which revealed an overall complication rate of 1.71% and a risk ratio of 0.99, suggesting no statistical difference between inpatient and outpatient groups.[6]

There may be a longer-term negative effect of outpatient ACDF. Arshi et al. examined more than 12,000 patients in a private insurance database and reported that outpatient ACDF was associated with higher odds of repeat anterior surgery at 1 year (OR 1.46) as well as a higher likelihood of undergoing posterior surgery at 6 months and 1 year (ORs 1.58 and 1.79, respectively).[3] The authors speculate that pressures for high throughput in an ambulatory setting may force surgeons to be less rigorous in endplate preparation, discectomy, or proper instrumentation, leading to higher rates of pseudarthrosis. Another interesting theory posits that the bias against the treatment of more than 2 levels may increase the proportion of patients with untreated milder adjacent segment disease, which subsequently progresses. Their findings underline the importance of studying longer-term outcomes beyond 30 or 90 days to truly evaluate whether outpatient spine surgery has an unanticipated impact.

Cervical Disc Arthroplasty

Cervical disc arthroplasty is a logical companion to outpatient ACDF and may actually lend itself to superior outcomes as patients in these cases are often younger with fewer baseline comorbidities. Moreover, the surgical principles favor less bony and soft tissue disruption. For now, the data on outpatient surgery are limited. Wohns reported on a personal series of 26 consecutive cervical disc arthroplasties with a minimum 4-hour observation period in a cohort of patients with a mean age of 46 years and no comorbidities.[46] There were no transfers to inpatient status, nor any readmissions or reoperations within 30 days. Another group compared 55 outpatient disc arthroplasty cases to an outpatient ACDF control group (55 patients) and again found no readmissions or reoperations within 30 days.[14]