Multimodal Approach of Isolated Pulmonary Vasculitis: A Single-Institution Experience

Ex Vivo Comparison of the Elastic Properties of Vascular Substitutes Used for Pulmonary Artery Replacement

INTRODUCTION

Study aims were to evaluate the elastic properties of vascular substitutes frequently used for pulmonary artery (PA) replacement, and then to compare their compliance and stiffness indexes to those of human PA.

METHODS

A bench-test pulsatile flow experiment was developed to perfuse human cadaveric vascular substitutes (PA, thoracic aorta, human pericardial conduit), bovine pericardial conduit, and prosthetic vascular substitutes (polytetrafluorethylene and Dacron grafts) at a flow and low pulsed pressure mimicking pulmonary circulation. Intraluminal pressure was measured. An ultrasound system with an echo-tracking function was used to monitor vessel wall movements. The diameter, compliance, and stiffness index were calculated for each vascular substitute and compared to the human PA at mean pressures ranging from 10 to 50 mmHg.

RESULTS

The compliance of the PA and the thoracic aorta were similar at mean physiological pressures of 10 mmHg and 20 mmHg. The PA was significantly less compliant than the aorta at mean pressures above 30 mmHg (P = 0.017). However, there was no difference in stiffness index between the two substitutes over the entire pressure range. Compared to the PA, human pericardial conduit was less compliant at 10 mmHg (P = 0.033) and stiffer at 10 mmHg (P = 0.00038) and 20 mmHg (P = 0.026). Bovine pericardial conduit and synthetic prostheses were significantly less compliant and stiffer than the PA for mean pressures of 10, 20, and 30 mmHg. There were no differences at 40 and 50 mmHg.

CONCLUSIONS

Allogenic arterial grafts appear to be the most suitable vascular substitutes in terms of compliance and stiffness for PA replacement.

Pulmonary endarterectomy in patients with occlusive isolated pulmonary vasculitis

BACKGROUND

Isolated pulmonary vasculitis (IPV) is a rare, insidious, and localized inflammatory disease affecting the pulmonary arteries, often leading to severe luminal obstruction. The prognosis for patients with occlusive IPV is poor, and there is currently a lack of effective treatments. The objective of this study was to evaluate the performance of pulmonary endarterectomy (PEA) as a treatment for occlusive IPV.

METHODS

This single-center retrospective analysis included patients who received PEA for occlusive IPV between January 2018 and June 2022. Clinical characteristics and hemodynamic parameters were evaluated at baseline and follow-up.

RESULTS

Among 114 consecutive patients who underwent PEA, occlusive IPV was identified in 7 patients. Two patients underwent bilateral PEA for the involvement of both pulmonary arteries. Patch angioplasty was performed to treat four severe constrictions. One patient died from residual pulmonary hypertension after limited PEA of a transmural vascular lesion. In addition, no obvious surgical complications were observed. Three months after PEA, a substantial relief in symptoms was achieved. Also, there is a decrease in the mean pulmonary artery pressure (median 33 [20-48] mmHg before versus median 21 [16-26] mmHg after; P < 0.018) and pulmonary arterial resistance (median 234 [131-843] dyn.s.cm-5 versus median 180 [150-372] dyn.s.cm-5; P = 0.310). Three patients experienced a relapse of restenosis of the treated arteries within a 6-month follow-up period, despite daily oral prednisolone administration. They were treated with balloon pulmonary angioplasty of both the main pulmonary arteries and branches.

CONCLUSIONS

PEA is a valuable choice for treating occlusive IPV, with notable hemodynamic and clinical advantages. To increase long-term vascular patency, complete management should be optimized.