P28. Complication rates following adult spinal deformity surgery: the category of complication dictates timing

Abstract

<h3>BACKGROUND CONTEXT</h3> Adult spinal deformity (ASD) is a complex pathology associated with high complication rates. Although complication rates have been previously reported, the interplay between timing and type of complications has not been fully analyzed. <h3>PURPOSE</h3> Provide benchmarks for the rates of complications by type and timing. <h3>STUDY DESIGN/SETTING</h3> Prospective multicenter database. <h3>PATIENT SAMPLE</h3> Operatively treated ASD patients with 2-year follow-up. <h3>OUTCOME MEASURES</h3> Rates of medical complications (cardiac, GI, infection, pulmonary, renal) and surgical complications (implant-related, operative, neurologic, radiographic) within 2 years postsurgery <h3>METHODS</h3> In the context of a prospective multicenter ASD database, standardized forms were used to collect data on surgery-related complications. Onsite research coordinators and central auditing helped ensure data capture completeness. Inclusion criteria were age >18 years, ASD and minimum 2-year follow-up. Date and type of complication were collected and classified into three severity groups (minor, major, major leading to reoperation). Only complications occurring before the 2-year visit were retained for analysis. <h3>RESULTS</h3> A total of 997 out of 1,260 patients eligible for 2-year follow-up (79.1%) were captured. The mean age at the time of surgery was 60.4yo±14.3, 76.3% were female and 50.5% had a history of previous spine surgery. The vast majority of patients (98.9%) had treatment including a posterior procedure, 57.9% had decompression, 71.2% had at least one osteotomy, and 18.1% had a 3-column osteotomy. Interbody fusion (IBF) was used in 64.0%: 48.7% posterior (TLIF or PLIF), 38.3% anterior (ALIF) and 23.2% lateral (LLIF). The mean ASD surgical invasiveness index was 88.8±36.1; 66.3% of the patients were admitted postop to the ICU, with a median overall length of hospital stay of 7 days (IQR 5 to 9). The overall complication rate was 67.4% (N=672). A total of 247 patients (24.8%) experienced at least one complication the day of surgery (including intraoperatively), 359 (36.0%) between POD1 and 6-weeks postoperatively, 271 (27.2%) between 6 weeks and 1-year postoperatively, and finally 162 (16.3%) between 1- and 2-years postoperatively. Using Kaplan-Meier survival analysis, the rate of remaining complication-free was estimated at 70.9% by POD1, 59.0% by POD7, 51.4% by 30 days, 47.4% by 3 months, and 33.6% by 2-years postoperatively. Breakdown by severity of remaining complication-free revealed the following rates for minor | major | reop: by POD1=87.3% | 90.1% | 97.4%; by POD7=78.4% | 86.8% | 95.8%; by 3 months=71.6% | 81.0% | 86.7%; by 6 months = 70.3% | 80.1% | 86.7%; and by 2-years postop=64.5% | 75.1% | 77.0%. Stratification by type of complication demonstrated that most of the medical complications occurred within the first 60 days. Surgical complications followed two types of behavior: operative, wound and infection occurred early (within 60 days), while implant-related and radiographic complications happened at a constant rate over the 2-year period. Neurologic complications had a high occurrence with the first 60 days, followed by a continuous increase up to the 2-year visit. <h3>CONCLUSIONS</h3> Only one-third of ASD patients remained complication-free 2-years postoperatively. Two patients out of ten had a complication requiring a reoperation/revision. Estimation of timing and type of complication associated with surgical treatment is crucial when counseling patients and planning treatment cost-effectiveness. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.