Microvascular Imaging as a Novel Tool for the Assessment of Blood Flow Velocity in Patients with Systemic Sclerosis: A Single-Center Feasibility Study

The Utility of a Novel Stacked Microvascular Imaging for Enhanced Detection of Fibrosis in Chronic Liver Diseases

OBJECTIVE

Ultrasonographic imaging plays a primary role to detect fibrotic changes in patients with chronic liver disease (CLD). To enhance detectability of fibrosis in its early stage, we developed a novel stacked microvascular imaging (SMVI) that enables continuous visualization of fibrotic changes in intrahepatic vessels.

METHODS

SMVI was produced by accumulating 3-5 seconds of high-definition color images in tilted-scan mode. An SMVI score was devised by quantitating three hallmark vascular changes in liver fibrosis in 0-2 grades (total 0-6): narrowing, caliber irregularity, and tortuosity. To evaluate the clinical utility of the SMVI score, 469 well-defined CLD patients were enrolled and subgrouped by the stage of liver fibrosis defined based on elastography: F0-1Low, F0-1High, F2, F3, and F4. The diagnostic performance of the SMVI score was compared to conventional B-mode liver morphology score and various laboratory test markers of fibrosis.

RESULTS

Unlike conventional microvascular imaging that relies on a single image, SMVI enabled an undisrupted view of intrahepatic vessels for easy detection of fibrotic changes. SMVI detected microvascular narrowing in 92% at stage F0-1High. While detection rates for caliber irregularity and tortuosity were low at early stages but increased proportionately in advanced stages. Multiple logistic regression analysis revealed that SMVI score was most accurate in distinguishing F0-1Low from F0-1High cases compared to B-mode or laboratory test scores.

CONCLUSION

SMVI provides enhanced vascular images of liver fibrosis in CLD, especially in its early stage. The SMVI score can be used as a primary tool for determining fibrotic stages in CLD.

Raynaud phenomenon and microvasculopathy in systemic sclerosis: multi-modality imaging for diagnosis and evaluation

PURPOSE OF REVIEW

To describe the clinical significance of and the diagnostic approach to Raynaud phenomenon (RP) in the peripheral extremities and the heart.

RECENT FINDINGS

Nailfold capillaroscopy has recently been standardized in an expert consensus paper. Abnormal capillaroscopy in combination with specific autoantibody profiles and clinical signs are highly predictive of progression of RP to systemic sclerosis (SSc). Magnetic resonance imaging (MRI) can also perform tissue characterization of both the extremities and the heart. Microvascular wall abnormalities detected using nailfold capillaroscopy in patients with SSc may lead to deposition of erythrocyte-derived iron, due to microhemorrhages, which may predispose to fibrosis. MRI can assess the presence of iron using T2∗ measurements.

SUMMARY

RP is a hallmark of the microvasculopathy in SSc and can affect both the peripheral extremities and the heart. Nailfold capillaroscopy is the current gold standard for the evaluation of the peripheral microvasculature. Other imaging modalities include thermography, laser Doppler-derived methods, 99m Tc-pertechnetate hand perfusion scintigraphy, power Doppler ultrasonography, dynamic optical coherence tomography, MRI, and photoacoustic imaging, but these are currently not widely used. Cardiac RP can be investigated with positron emission tomography or cardiovascular magnetic resonance, with the latter offering the additional possibility of tissue characterization and iron content quantification secondary to microhemorrhages.

Ultrasound quantitative assessment of ventral finger microvasculopathy in systemic sclerosis with Raynaud's phenomena: a comparative study

OBJECTIVE

To assess the finger vascularity of systemic sclerosis patients with Raynaud's phenomenon (RP-SSc) using various ultrasound techniques.

METHODS

All fingers (except thumbs) of 18 RP-SSc patients and 18 controls were imaged at room temperature using four ultrasound vascular imaging techniques. The percent vascular area was quantified by counting blood flow pixels in a 25 mm² square centred at the nail fold for the dorsal side and in 25 mm² and 100 mm² square from the fingertip for the ventral side. The mean vascular intensity was calculated from the corresponding areas for dorsal and ventral sides.

RESULTS

The percent vascular areas and mean vascular intensities in RP-SSc were significantly lower than those in controls for both dorsal and ventral sides (p<0.01). The mean vascular intensities showed slightly higher area under the curve (AUC) than the percent vascular areas (0.53-0.91 vs 0.53-0.90) regardless of imaging technique and assessment side. For each imaging technique, the ventral side vascularity showed a higher AUC (0.74-0.91) compared with the dorsal side (0.53-0.81). Moreover, ventral side abnormalities were associated with a history of digital ulcers.

CONCLUSIONS

Ultrasound demonstrated potential to quantify finger vascularity of RP-SSc. The ventral side of the fingers showed a higher accuracy in detecting RP-SSc than the dorsal side.

Study Protocol: A Randomized Controlled Prospective Single-Center Feasibility Study of Rheopheresis for Raynaud’s Syndrome and Digital Ulcers in Systemic Sclerosis (RHEACT Study)

Introduction

Raynaud’s phenomenon (RP) and digital ulcers (DU) are frequent manifestations of Systemic Sclerosis (SSc). Despite being very common in SSc patients, both conditions have proven to be notoriously difficult to study. There are very few available approved drugs with varying efficacy. It has been shown that the presence of DU is associated with increased whole blood viscosity (WBV). Rheopheresis (RheoP) is an extracorporeal apheresis technique used to treat microcirculatory disorders by improving blood viscosity. Improved blood flow and wound healing after RheoP treatments have been reported in single case reports.

Methods and Analysis

We report the clinical trial protocol of “A randomized controlled prospective single-center feasibility study of Rheopheresis for Raynaud’s syndrome and Digital Ulcers in Systemic Sclerosis (RHEACT).” RHEACT aims to investigate the efficacy of RheoP on the Raynaud Condition Score (RCS) as the primary efficacy outcome measure after 16 weeks from baseline. Thirty patients will be randomized in a 1:1:1 ratio to one of two RheoP treatment groups or assigned to the standard of care (SoC) control group (intravenous iloprost). Secondary endpoints include changes in DU, changes in nailfold video capillaroscopy and patient-reported-outcomes (Scleroderma Health Assessment Questionnaire, FACIT-Fatigue, and the Disability of Arm, Shoulder, and Hand, quick version).

Discussion

Apheresis techniques have been investigated in SSc but mainly in observational, retrospective studies, or single case reports. RheoP is a pathophysiologically driven potential new therapy for heavily burdened patients with SSc-associated secondary RP with or without DU.

Ethics and Dissemination

The study was registered at clinicaltrials.gov (Identifier: NCT05204784). Furthermore, the study is made publicly available on the website of the German network of Systemic Sclerosis “Deutsches Netzwerk Systemische Sklerodermie (DNSS).”

Endothelial Dysfunction in Systemic Lupus Erythematosus and Systemic Sclerosis: A Common Trigger for Different Microvascular Diseases

This review describes the complex interplay between inflammation, vasculopathy and fibrosis that involve the heart and peripheral small vessels, leading to endothelial stiffness, vascular damage, and early aging in patients with systemic lupus erythematosus and systemic sclerosis, which represents two different models of vascular dysfunction among systemic autoimmune diseases. In fact, despite the fact that diagnostic methods and therapies have been significantly improved in the last years, affected patients show an excess of cardiovascular mortality if compared with the general population. In addition, we provide a complete overview on the new techniques which are used for the evaluation of endothelial dysfunction in a preclinical phase, which could represent a new approach in the assessment of cardiovascular risk in these patients.