Wednesday, September 26, 2018 7:35 AM–9:00 AM ePosters: P39. Modic 2 changes and smoking predict vascular adherence during anterior lumbar exposure

Abstract

BACKGROUND CONTEXT An anterior approach to access lumbar intervertebral discs risk major vascular injury and significant bleeding. We aimed to identify predictive factors for vascular adherence to allow pre-operative planning and technique modification. METHODS Retrospective analysis of a prospectively collected database was performed of consecutive patients undergoing anterior retroperitoneal exposure for lumbar disc surgery from 2009 to 2016. Data collected included demographic factors, smoking status, MRI findings, operative parameters and difficulty of dissection due to vascular adherence (standard or difficult). Smokers were defined as those currently smoking or had ceased smoking within 6 months of operation. Exclusion criteria were morbid obesity, previous anterior spine surgery or radiotherapy. RESULTS Multivariate analysis of 246 patients (mean age 42.5years (21–80), male 50%) demonstrated two statistically significant risk factors – Modic 2 changes on MRI (P=.009) and smoking status (p=.007). Of 57 patients with Modic 2 changes at the operative level, 16 had a difficult dissection due to vascular adherence (28%). Of 189 patients without Modic 2 changes, only 25 patients had a difficult dissection (13%) (p=.014). Patients with Modic 2 changes were 2.1times more likely to have vascular adherence.Of 125 nonsmoking patients, 13 had a difficult dissection (10%). Of 83 ex-smokers, 19 had a difficult dissection (23%) and of 38 current smokers, nine had a difficult dissection (24%). Overall, of the 121 smokers (ex- and current), 28 had a difficult dissection (23%) (p=.01). Patients with any smoking history were 2.2times more likely to have vascular adherence. CONCLUSIONS Modic 2 changes on MRI and any smoking history predicted adherence of the large vessels to the anterior disc annulus leading to a more difficult dissection. These two predictors should alert the surgeon to the potential for a challenging dissection and major vascular injury.