1563: Common Femoral Vein Wall Thickness Measurement as a Diagnostic Test in Incomplete Behçet’s Disease

Fatma Alibaz-Oner¹, seda kutluğ ağaçkıran², Rabia Ergelen³, Fatma Temiz³, efe Soydemir³, Tulin Ergun⁴ and Haner Direskeneli⁵, ¹Marmara University, Rheumatology, Istanbul, Turkey, ²Marmara University School of Medicine, Division of Rheumatology, Istanbul, Turkey, ³Marmara University, School of Medicine, Departmant of Internal Medicine, Istanbul, Turkey, ⁴Marmara University, School of Medicine, Department of Dermatology, Istanbul, Turkey, ⁵Marmara University, Rheumatology, Istanbul, Istanbul, Turkey

Background/Purpose: Diagnosing Behçet's Disease (BD) can be a clinical challenge in patients presenting with limited organ manifestations, especially with single major organ involvement. We reported the first controlled Doppler Ultrasound study showing increased common femoral vein (CFV) thickness in BD (1). We recently also showed that increased CFV thickness is a distinctive feature of BD with a specificity higher than 80% for the cut-off value of ≥ 0.5 mm (2). In this study, we aimed to assess the diagnostic performance of CFV thickness measurement in patients with 'Incomplete' BD diagnosed by expert opinion.

Methods: We included 48 patients with incomplete BD (26 male, 22 female) diagnosed with expert opinion and followed in the Marmara University Behçet's Clinic. Demographic, clinical characteristics and treatment data were recorded during routine visits. CFV wall thickness was measured by an experienced radiologist on the same day.

Results: The mean age of the patients was 39.1 (SD:11.1). The mean duration of BD was 53.7 (SD: 51.4) months. 40 (83.3%) of BD patients had major organ involvement. 6 (12.5%) patients had pathergy positivity and 15 (31.3%) had familial BD. 20, 8, and 6 of the patients had vascular, ocular, and neurological involvement, respectively. Right CFV thickness was 0.72 (SD: 0.15) mm and left CFV thickness 0.72 (SD: 0.15) mm. Only 2 (4.2%) patients had CFV thickness values below the cut-off value of ≥ 0.5 mm.

Conclusion: Diagnosing BD can be challenging in patients presenting with one major organ involvement, especially in countries with a low prevalence. These patients are generally diagnosed as 'incomplete' BD by 'expert opinion'. Early diagnosis is of utmost importance in some of these cases. Our results show that CFV thickness measurement with Doppler US, a non-invasive radiological modality, is a valuable diagnostic test in incomplete BD, especially with major organ involvement.

References:
1- Alibaz-Oner F. et al. Venous vessel wall thickness in lower extremity is increased in male patients with Behcet's disease. Clin Rheumatol 2019;38:1447- 51.
2- Alibaz-Oner F. et al. Femoral vein wall thickness measurement: A new diagnostic tool for Behcet's disease. Rheumatology (Oxford). 2021 Jan 5;60(1):288-296

Figure 1: Distribution of major organ involvements (n) in the study group

Table 1: Subgroup analysis of incomplete BD patients
Disclosures: F. Alibaz-Oner, None; s. kutluğ ağaçkıran, None; R. Ergelen, None; F. Temiz, None; e. Soydemir, None; T. Ergun, None; H. Direskeneli, None.