Abstract No. 658 Exercise intolerance caused by chronic iliocaval venous occlusion: non-invasive quantitative assessment

Abstract

Patients with chronic inferior vena cava (IVC) and bilateral iliac vein postthrombotic occlusion often report subjective decreased exercise tolerance that improves after stent reconstruction. We report preliminary results of the use of quantitative exercise testing to assess change in exercise tolerance occurring after venous reconstruction. The Institutional Review Board approved this retrospective study. Exercise testing before and after intervention was conducted in the Human Performance Laboratory (HPL): resting blood pressure, heart rate, body mass index (BMI), body composition, standard pulmonary function tests, and incremental maximal exercise testing (VO2 max test). Maximal exercise was defined as a plateau in the oxygen uptake, a respiratory exchange ratio (RER) greater than 1.1, or voluntarily termination of exercise. The VO2 max (mL/kg/min), maximum work (W) and total exercise time were analyzed. Percutaneous venous reconstruction was performed using standard techniques and stents. Results were reported as simple averages and percentages. Three male patients with chronic postthrombotic IVC and bilateral iliac venous occlusions were studied. Mean age 63 ± 8 years, mean duration of occlusion 36 ± 12 months. The interval between reconstruction and testing ranged from 2.5 to 11 months. All patients had stents in the infra-renal IVC to bilateral common femoral veins. No exercise instructions were provided to patients after stent reconstruction. Following venous reconstruction, the V02 max increased an average of 38.7%, the total work increased 74.4%, and the total exercise time increased 18.7%. Each individual lost weight, with an average decrease of 7.5%. Subjectively, all patients reported an increased exercise tolerance and decreased shortness of breath with exertion. Subjective impairment in exercise tolerance and improvement after venous reconstruction was quantitated in three patients with chronic postthrombotic occlusion of the IVC and bilateral iliac veins. HPL testing may be a useful additional objective tool in the study of patients with chronic ilio-caval occlusions.