Hidraulic device for gradual occlusion in the canine pulmonary artery

Abstract

A HYDRAULIC OCCLUSION DEVICE (HOD) MADE OF INERT AND BIOCOMPATIBLE MATERIAL IS PRESENTED HERE. BY INJECTING WATER INTO THE DEVICE, IT EXPANDS AND CAUSES COMPRESSION OF THE MAIN PULMONARY ARTERY, CONSEQUENTLY INCREASING THE RIGHT VENTRICULAR SYSTOLIC PRESSURE (RVSP) TO MIMIC THE EFFECT OF PULMONARY DISEASE OF THE RIGHT VENTRICLE. INERT AND BIOCOMPATIBLES MATERIALS IN THE CONSTRUCTION OF THE DOH WERE USED. AFTER TESTING THE HOD FOR DISTENTION, THE DEVICES WERE SURGICALLY IMPLANTED INTO THE MAIN PULMONARY ARTERY OF 12 HEALTHY, MONGREL DOGS WEIGHING 18-28 KG. BOTH THE PRE AND POST-SURGICAL RVSP, AND THE RVSP UNDER ACUTE AND CHRONIC COMPRESSION WERE ASSESSED. RESULTS ARE EXPRESSED AS MEAN ± STANDARD DEVIATION. DIFFERENCES BETWEEN RVSP UNDER BASAL AND ACUTE COMPRESSION WERE COMPARED USING THE T TEST FOR PAIRED GROUPS; WHILE DIFFERENCES BETWEEN RVSP UNDER BASAL AND CHRONIC COMPRESSION WERE COMPARED USING MULTIPLE SAMPLE ANOVA WITH BONFERRONI'S ADJUSTMENT. STATISTICAL SIGNIFICANCE WAS CONSIDERED WHEN P < 0.05. CHAMBER PRESSURES AT KNOWN VOLUMES RANGED FROM 1.4 ± 1.4 MMHG FOR 0.1 ML OF WATER TO 185.8 ± 9.3 MMHG FOR 0.8 ML OF WATER. BASAL PRE AND POST-SURGICAL RVSP WERE 20.9 ± 3 MMHG AND 22 ± 2 MMHG, RESPECTIVELY (P < 0.871). AFTER ACUTE COMPRESSION, BASAL RVSP INCREASED FROM 22 ± 2 MMHG TO 58 ± 3 MMHG (P < 0.001); WHILE AFTER CHRONIC COMPRESSION, RVSP INITIALLY INCREASED TO 41.7 ± 1.1 MMHG, REACHING 61.4 ± 1.9 MMHG (P < 0.005). THE HOD ALLOWED MAINTAINING THIS PRESSURE LEVEL FOR 60 DAYS. THE HOD IS A VERSATILE DEVICE THAT CAN BE USED TO ACUTELY OR CHRONICALLY INCREASE THE RVSP.