Use of navigation in patients undergoing surgery for adult spinal deformity (ASD) is associated with higher operative time and transfusion compared to conventional surgery, suggesting that navigation carries an increased risk of infection-related events, a new retrospective study has found.
The objective of the study, the findings of which were published in The Spine Journal, by Austen Katz (Northwell Health Orthopaedics, New York, USA) et al, was to compare 30-day readmission, reoperation, morbidity, and value-per-operative time for navigated and conventional ASD surgery.
The study authors note that navigation “has been increasingly used to treat degenerative disease, with positive radiographic and clinical outcomes and fewer adverse events and reoperations, despite increased operative time”. However, short-term analysis on treating ASD surgery with navigation “is limited, particularly using large nationally represented cohorts”.
Patients were included from the US National Surgical Quality Improvement Program (NSQIP) database. Multivariate regression was used to compare outcomes between navigated and conventional surgery and to control for predictors and baseline differences.
A total of 3,190 ASD patients were included in the study with a similar split between navigated and conventional patients. Findings showed that navigated cases had greater operative time (405 minutes versus 320 minutes) and mean relative value units (RVUs) per case (81.3 vs. 69.7), and had more supplementary pelvic fixations (26.1 vs. 13.4%) and osteotomies (50.3 vs. 27.7%) (P<0.001).
In univariate analysis, navigation had greater reoperation (9.9 versus 5.2%, p=0.011), morbidity (57.8 vs. 46.8%, p=0.007), and transfusion (52.2 vs. 41.8%, p=0.010) rates. Readmission was similar (11.9 vs. 8.4%). In multivariate analysis, navigation predicted reoperation (OR=1.792, p=0.048), but no longer predicted morbidity or transfusion. Most reoperations were infectious and hardware-related.
Katz et al conclude that, despite controlling for patient-related and procedural factors, navigation independently predicted 79% increased odds of reoperation but did not predict morbidity or transfusion. They add that readmission was similar between groups which can be explained, in part, by the greater operative time and transfusion, which are risk factors for infection.
Speaking to Spinal News International, Katz said: “We hope that these findings ultimately spark large scale multicentre prospective studies that specifically evaluate the role that navigation may have in relation to surgical site and infectious-related events, specifically in light of increased set-up and OR times, operating room personnel, O-arm spins, and time spent in sub-sterile rooms as well as surgeon learning curve. Identification and mitigation of potential risk factors can help maximise the utility and benefits of navigated surgery, particularly in technically demanding cases.”