Introduction: Surgical site infection (SSI) in spinal surgery contributes to significant morbidity, healthcare resource utilization, and cost. Its prevalence is reported in the literature to range from 0.7-12%, depending on type of surgery and patient population. Few studies have directly compared the rate of minimally invasive surgery (MIS) SSI with open surgery. SSI is a cause of unplanned hospital readmission. Anecdotal evidence suggests a lower incidence of SSI with the use of minimally invasive techniques. We sought to investigate whether MIS techniques had a smaller SSIR in degenerative lumbar procedures as compared with traditional open techniques.

Methods: A single-center, retrospective review of a prospectively collected database was queried from January 2013 to January 2016. All adult patients who underwent lumbar decompression and/or instrumented fusion for which the surgical indication involved degenerative disease. The surgical site infection rate was determined for all procedures as well as in the open and minimally invasive groups. Risk factors associated with SSI, body mass index (BMI), estimated blood loss (EBL) and diabetes (DM), were also reviewed for each patient.

Results: A total of 1,442 lumbar spinal procedures were performed during this time period. Of these, there were 961 MIS and 481 open (67% vs. 33%, respectively). The overall surgical site infection rate was 1.5% (21/1,442). The infection rates for MIS and open were 0.5% (5/961) and 3.3% (16/481), respectively, p=0.16. For the decompression only group the infection rate for MIS and open was 0.4% vs 3.9% (p=0.04), and for decompression with fusion it was 0.7% vs 2.6%, respectively (p=0.68).

Conclusions: Our study demonstrates a sevenfold reduction in surgical site infections was observed when comparing minimally invasive surgery with open surgery. Furthermore, there was a statistically significant tenfold reduction for procedures involving decompression alone, and a fourfold reduction in procedures that required fusion as well as decompression.

Patient Care: This research shows that MIS techniques in lumbar decompressive procedures can reduce the SSIR. This will limit patient morbidity and is a step towards reducing overall healthcare costs. Further value-based analysis will be performed to understand the ecumenic impact of these techniques in spine surgery.

Learning Objectives: 1. Minimally invasive surgical techniques lead to reduced rate of SSI in lumbar decompressive procedures. 2. Less SSI in MIS groups were deep infections requiring surgical intervention. 3. Further cost analysis can help shed light on the value of these techniques.

References: See manuscript