Xylose absorption test before and after surgical repair of coarctation of the aorta.

The aim of the study was to ascertain whether the acceleration of physical development in children after operation for coarctation of the aorta is due to the improved intestinal absorption. Lowered values of the oral xylose absorption test were found in all 9 patients before surgery. In all the patients who had been operated on, sphigmo-oscillometry revealed an increased pulsatile character of the blood flow, pulsatile volume in the lower extremities, and a rise of mean arterial blood pressure in this area. On the other hand, surgical repair had no influence on the renal blood flow as evidenced by PAH clearance and isotope renography. There was no correlation of diuresis and the xylose excretion test. Increased values of the xylose test after operation for coarctation of the aorta are due to the increased intestinal absorption rather than to improved renal function. Improved intestinal absorption may be a factor responsible for the accelerated physical development of children operated on for coarctation of the aorta.