Background: Raynaud's phenomenon (RP) is a frequent vascular paroxysmal syndrome of the extremities. Generally benign, the condition is called Raynaud's disease (RD), which may reveal a connective tIssue disease, particularly systemic sclerosis (SS). We evaluated digital blood flow in patients with RD and SS using color Doppler ultrasound.
Patients and methods: Ultrasound examination was performed with a newly developed multi-D linear array transducer (VFX 13-5 Siemens), which allows better resolution. We first measured the diameters of the digital arteries (appendix 1) then epidermal, dermal, and hypodermal thickness for each patient (appendix 3) and performed a qualitative and quantitative analysis of pulpar microcirculation (appendix 4 & 5). All measures were made at 25 degrees C, 45 degrees C, 11 degrees C and after recovery. Thirty-three patients were included: 14 with primary RD and 19 with SS as assessed by American College of Rheumatology criteria.
Results: The diameters of the digital arteries showed significant discrepancies allowed to distinguish primary RP from SS. At 11 degrees C, diameters were 0.6 +/- 0.2 mm for primary RP versus 0.2 +/- 0.3 mm for SS on lateral digital arteries (LDA) [p=0.005]; 0.7 +/- 0.2 mm for primary RP versus 0.4 +/- 0.3 mm for SS on medial digital arteries (MDA) [p=0.004]. After recovery, these diameters were respectively 1 +/- 0.2 mm versus 0.5 +/- 0.4 mm for LDA [p=0.000] and 1 +/- 0.2 mm versus 0.6 +/- 0.3 mm for MDA [p=0.000] (tables 1, 2, 3, 4). Similarly, pulpar vascularization was significantly higher in primary RP than in SS (tables 6, 7, 8). No difference was found in skin thickness nor in the epidermal aspect between the two groups (table 5).
Conclusion: Color Doppler ultrasound shows morphological and dynamic differences between RD and SS.