Elsevier

The Spine Journal

Volume 10, Issue 10, October 2010, Pages 881-889
The Spine Journal

Clinical Study
Comparative in-hospital morbidity and mortality after revision versus primary thoracic and lumbar spine fusion

https://doi.org/10.1016/j.spinee.2010.07.391Get rights and content

Abstract

Background context

Despite increasing utilization of surgical spine fusions, a paucity of literature addressing perioperative complications after revision posterior spinal fusion (RPSF) versus primary posterior spine fusion (PPSF) of the thoracic and lumbar spine exists.

Purpose

To examine demographics of patients undergoing PPSF and RPSF of the thoracic and lumbar spine, assess the incidence of perioperative morbidity and mortality, and determine independent risk factors for in-hospital death.

Study design/setting

Analysis of nationally representative data collected for the National Inpatient Sample (NIS).

Patient sample

All discharges included in the NIS with a procedure code for posterior thoracic and lumbar spine fusion from 1998 to 2006.

Outcome measures

In-hospital mortality and morbidity.

Methods

Data collected for each year between 1998 and 2006 for the NIS were analyzed. Discharges with a procedure code for thoracic and lumbar spine fusion were included in the sample. The prevalence of patient- as well as health care–related demographics was evaluated by procedure type (primary vs. revision). Frequencies of procedure-related complications and in-hospital mortality were analyzed. Independent predictors for in-hospital mortality were determined.

Results

We identified 222,549 PPSF and 12,474 RPSF discharges between 1998 and 2006. Patients undergoing PPSF were significantly younger (51.23 years; confidence interval [CI]=51.16, 51.31) and had lower average comorbidity indices (0.40; CI=0.39, 0.41) than those undergoing RPSF (52.69 years; CI=52.43, 52.97) and (0.44; CI=0.43, 0.45), p<.0001. The incidence of procedure-related complications was 16.02% among RPSF compared with 13.44% in PPSF patients (p<.0001). In-hospital mortality rates after PPSF were approximately twice those of RPSF (0.28% vs. 0.15%, p=.006). Adjusted risk factors for increased in-hospital mortality included PPSF compared with RPSF, male gender, and increasing age. A number of comorbidities, complications, and specific surgical indications increased the risk for perioperative death.

Conclusion

Despite being performed in generally younger and healthier patients and having lower perioperative morbidity, PPSF procedures are associated with increased mortality compared with RPSF procedures. The findings of this study can be used for risk stratification, accurate patient consultation, and hypothesis formation for future research.

Introduction

Evidence & Methods

Morbidity and mortality rates following primary posterior, versus revision posterior, thoracolumbar fusions are difficult to estimate with precision using the existing literature. The authors analyzed data from the National Inpatient Sample.

Patients undergoing primary fusion were younger, had fewer comorbidities, and suffered fewer overall complications than those undergoing revision fusion. However, primary operations were also associated with higher mortality rates. Increasing age and male gender also predicted increased mortality.

The information may be useful for patient education and informed consent. Readers are reminded to consider adequacy of cohort matching, accuracy of available data, potential for missing data, and differences between statistical and clinical significance when assessing information gathered from a very large database.

—The Editors

Lumbar surgery rates have dramatically increased over the past 2 decades in the United States. Fusion procedures in particular increased by approximately 220% since 1990 [1], [2]. Furthermore, the cumulative incidence of reoperation after lumbar fusion surgery is substantial, with rates up to 20.1% being reported at 10 years [3]. However, despite the increasing utilization of these procedures, a paucity of nationally representative outcome data comparing primary and revision spine fusion surgery exists. Knowledge of the incidence of perioperative complications and adverse events after primary and revision lumbar fusion is critical for physicians to anticipate clinical needs and adequately inform patients of the risks involved.

The purpose of this study was to use data collected for the National Inpatient Sample (NIS) to identify patient- and health care system–related demographics associated with the utilization of both primary posterior spinal fusion (PPSF) procedure and revision posterior spinal fusion (RPSF) procedure; determine the incidence of perioperative complications in a comparative fashion; and identify risk factors associated with morbidity and mortality in these procedures. These data may help physicians identify patients at risk and direct future research to improve perioperative outcomes.

Section snippets

Study sample and analysis

As part of the Healthcare Cost and Utilization Project (HCUP), the NIS is sponsored by the Agency for Healthcare Research and Quality. The NIS is the largest all-payer inpatient care database in the United States; containing data from approximately 8 million hospital stays, from about 1,000 hospitals sampled to approximate a 20% stratified sample of US community hospitals. To be able to produce national estimates, both hospital and discharge weights are provided, along with information

Demographics

A summary of patient and hospital characteristics by procedure type is shown in Table 2. A total number of 222,549 PPSF and 12,474 RPSF discharges between 1998 and 2006 were identified, representing a weighted national estimate of 1,082,931 and 59,926 hospitalizations for each procedure, respectively. Most posterior spine fusion (PSF) patients were female (55.34% of PPSF and 57.39% of RPSF) and white (88.11% of PPSF and 89.88% of RPSF). In addition, most PSFs were performed in hospitals that

Discussion

This study used data collected for the NIS between the years of 1998 and 2006 to compare short-term morbidity and mortality after primary and revision spinal fusions and identify risk factors for such events among these procedures. Revision posterior spinal fusion procedures were associated with an increased incidence of perioperative complications when compared with PPSF. In contrast, PPSF were associated with increased adjusted risk of in-hospital mortality when compared with RPSF procedures.

References (25)

  • J.D. Schwender et al.

    Perioperative complications in revision anterior lumbar spine surgery: incidence and risk factors

    Spine

    (2008)
  • N.B. Oldridge et al.

    Lumbar spine surgery and mortality among medicare beneficiaries, 1986

    Am J Public Health

    (1994)
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    FDA device/drug status: not applicable.

    Author disclosures: FPG (royalties, Nuvasive, OrthoDevelopment, DePuy; stock ownership, including options and warrants, Nuvasive; private investments, including venture capital, start-ups, Surgical Pioneer; consulting, Osteotech, Paradigm, Sentinel; scientific advisory board, Scient’x).

    Dr Yan Ma was partially supported by the grant, Clinical Translational Science Center (CTSC) (UL1-RR024996).

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