In-hospital complication rate following microendoscopic versus open lumbar laminectomy: a propensity score-matched analysis

Abstract

Background Context

The incidence of postoperative complications after microendoscopic laminectomy (MEL) has not been compared with that after open laminectomy in a large study, so it is not clear whether MEL is a safer procedure.

Purpose

The objective of this study was to compare postoperative morbidity and mortality following lumbar laminectomy between patients treated with MEL and with open laminectomy.

Study Design

This is a retrospective cohort study with propensity score-matched analysis.

Patient Sample

Data of patients who underwent elective spinal surgery between July 2010 and March 2013 were extracted from the Diagnosis Procedure Combination database, a nationwide inpatient database in Japan.

Outcome Measures

Clinical outcomes included length of hospital stay, occurrence of major complications (cardiac events, respiratory complications, pulmonary embolism, stroke, and acute renal failure), surgical site infection (SSI), postoperative delirium, and in-hospital death.

Materials and Methods

Propensity score matching was performed to adjust for measured confounding factors, including patient age, sex, Charlson Comorbidity Index, body mass index, smoking status, blood transfusion, duration of anesthesia, number of operated disc levels, and type of hospital and hospital volumes. The clinical outcomes of one-to-one propensity-matched pairs of the MEL and the open laminectomy groups were compared.

Results

Of 23,317 patients identified in the database, 1,536 underwent MEL (6.6%). By one-to-one propensity score matching, 1,536 pairs were selected. The distributions of patient backgrounds were closely balanced between the MEL and the open laminectomy groups. An analysis of 1,536 pairs revealed that there was a significantly lower incidence of major postoperative complications in those who underwent MEL (1.0% vs. 2.8% for open laminectomy, risk difference 1.8%, 95% confidence interval [CI] 0.9%–2.9%), SSI (0.5% vs. 1.6% for open laminectomy, risk difference 1.1%, 95% CI 0.4%–1.9%), and postoperative delirium (1.1% vs. 2.3% for open laminectomy, risk difference1.2%, 95% CI 0.3%–2.1%). The length of hospital stay was significantly shorter in those treated with MEL (12 days vs. 16 days for open laminectomy, p<.001). There was no significant difference in in-hospital mortality between the groups.

Conclusions

Patients who underwent MEL were significantly less likely to experience major postoperative complications and were less likely to develop SSI and postoperative delirium than those who underwent open laminectomy.

Introduction

Lumbar spinal stenosis is one of the most common orthopedic disorders in increasingly elderly populations. This disorder causes spinal claudication, back and leg pain, and disability. There has recently been an increase in the popularity of minimally invasive surgery (MIS) for lumbar spinal disorders. Foley and Smith first described minimally invasive lumbar laminectomy using microendoscopic procedures in 1997 [1]. Microendoscopic laminectomy (MEL) is a modification of microscopic bilateral decompression via a unilateral approach [2]. This technique is popular and reported outcomes are good [2], [3], [4]. However, it remains unclear whether MEL is safer than open laminectomy, as no large study has been performed to compare postoperative outcomes after the two procedures. It is imperative to know the risks of surgery to inform appropriate clinical decision-making.

The purpose of the present study was to compare in-hospital complications of patients undergoing MEL with those treated with open laminectomy using a nationwide database in Japan.