Ten-year clinical and imaging follow-up of dural ectasia in adults with Marfan syndrome

Background context: Dural ectasia in the lumbosacral spine is a common feature of Marfan syndrome and is associated with low back pain and surgical complications, but its natural history is unknown. Purpose: To evaluate the natural history of dural ectasia in adults with Marfan syndrome by determining if, over time, symptoms associated with dural ectasia worsen, dural ectasia imaging findings worsen, or spondylolisthesis/spondylolysis develops or worsens. Study design: Prospective cohort study. Patient sample: For our prospective follow-up study, we enrolled 20 patients with Marfan syndrome and dural ectasia who, from 1998 through 1999, had undergone magnetic resonance imaging (MRI) and computed tomography (CT) of the lumbosacral spine and had completed the Oswestry Disability Index (ODI) questionnaire. Of the 20, five did not meet the inclusion criterion of a completed 2009 ODI questionnaire and were excluded. The remaining 15 patients (mean age, 49.6 years; mean follow-up, 10.5 years) formed our study group. Outcome measures: The ODI, MRI-based qualitative and quantitative measurements, CT-based quantitative measurements. Methods: We performed matched-pair analyses via Student t test and Wilcoxon signed-rank test of the ODI scores (15 pairs), dural volume of L5-S2 (eight pairs), dural sac ratio (DSR) of L4-S2 (nine pairs), development/progression of spondolysthesis/spondylolysis (11 pairs), and Fattori qualitative grading of dural ectasia size (10 pairs). Significance was set at p<.05. Results: We found no statistical differences in the 1998/1999 and 2009 ODI scores (25.8 vs. 22.2 points), dural volume (70.4 vs. 73.9 cm³), or DSR (0.68, 0.78, 2.04, and 58.1 vs. 0.69, 0.83, 2.30, and 70.20). There was also no development or progression of spondylolisthesis/spondylolysis and no increase in dural ectasia size. Conclusions: During this 10-year period, the natural history of dural ectasia in adults with Marfan syndrome was not associated with a significant increase in ODI scores, dural ectasia size, or with the development/progression of spondylolisthesis or spondylolysis.