The influence of different surgical procedures on hypertension after repair of coarctation

Abstract

We measured resting and exercise haemodynamics, as well as 24-hour ambulatory blood pressure, so as to study the influence on development of hypertension in children after repair of coarctation by either construction of a subclavian flap or end-to-end anastamosis. The patients in both groups were studied a mean time of 13 years after surgery. Thus, we divided 43 children who had undergone surgical repair of coarctation, and who were not on antihypertensive therapy, into a group of 22 patients who had undergone subclavian flap repair, with a mean age of 14 plus or minus 2.6 years, and another group of 21 patients undergoing end-to-end anastomosis, with a mean age of 13.5 plus or minus 3.9 years. We examined blood pressure at rest and during exercise, along with the measurement of cardiac output using impedance cardiography, and during 24-hour ambulatory monitoring. We recorded systolic and diastolic blood pressures, pulse pressure, cardiac output and total peripheral vascular resistance at rest and at peak exercise. During ambulatory monitoring, we measured mean pressures over 24 hours, in daytime and nighttime, 24-hour pulse pressure, and 24-hour mean arterial pressure. Student's t test was used to judge significance, accepting this when p was less than 0.05. The group repaired using the subclavian flap showed significantly disadvantageous differences for diastolic blood pressure at rest, systolic blood pressure at peak exercise and for 24-hour systolic and diastolic blood pressure, 24-hour mean arterial pressure, and daytime and nighttime systolic blood pressure during ambulatory monitoring. Our findings suggest that, after repair using the subclavian flap in comparison to end-to-end anastomosis, patients show a higher incidence of late hypertension, both during exercise and ambulatory monitoring. The data indicate different residual aortic stiffnesses, these being lower after end-to-end anastomosis, which may be due to the greater resection of the abnormal aortic tissue when coarctation is repaired using the latter technique.