RESUMO
Severity assessment for coarctation of the aorta (CoA) is challenging due to concomitant morphological anomalies (complex CoA) and inaccurate Doppler-based indices. Promising diagnostic performance has been reported for the continuous flow pressure gradient (CFPG), but it has not been studied in complex CoA. Our objective was to characterize the effect of complex CoA and associated hemodynamics on CFPG in a clinical cohort. Retrospective analysis identified discrete juxtaductal (n = 25) and complex CoA (n = 43; transverse arch and/or isthmus hypoplasia) patients with arm-leg systolic blood pressure gradients (BPG) within 24 h of echocardiography for comparison to BPG by conventional Doppler indices (simplified Bernoulli equation and modified forms correcting for proximal kinetic energy and/or recovered pressure). Results were interpreted using the current CoA guideline (BPG ≥ 20 mmHg) to compare diagnostic performance indicators including receiver operating characteristic curves, sensitivity, specificity, and diagnostic accuracy, among others. Echocardiography Z-scored aortic diameters were applied with computational simulations from a preclinical CoA model to understand aspects of the CFPG driving performance differences. Diagnostic performance was substantially reduced from discrete to complex CoA for conventional Doppler indices calculated from patient data, and by hypoplasia and/or long segment stenosis in simulations. In contrast, diagnostic indicators for the CFPG only modestly dropped for complex vs discrete CoA. Simulations revealed differences in performance due to inclusion of the Doppler velocity index and diastolic pressure half-time in the CFPG calculation. CFPG is less affected by aortic arch anomalies co-existing with CoA when compared to conventional Doppler indices.
RESUMO
Aims: Severity assessment for coarctation of the aorta (CoA) is challenging due to concomitant morphological anomalies (complex CoA) and inaccurate Doppler-based indices. Promising diagnostic performance has been reported for the continuous flow pressure gradient (CFPG), but it has not been studied in complex CoA. Our objective was to characterize the effect of complex CoA and associated hemodynamics on CFPG in a clinical cohort. Methods and Results: Retrospective analysis identified discrete juxtaductal (n=25) and complex CoA (n=43; transverse arch and/or isthmus hypoplasia) patients with arm-leg systolic blood pressure gradients (BPG) within 24 hours of echocardiography for comparison to BPG by conventional Doppler indices (simplified Bernoulli equation and modified forms correcting for proximal kinetic energy and/or recovered pressure). Results were interpreted using the current CoA guideline (BPG ≥20 mmHg) to compare diagnostic performance indicators including receiver operating characteristic curves, sensitivity, specificity, and diagnostic accuracy, among others. Echocardiography Z-scored aortic diameters were applied with computational stimulations from a preclinical CoA model to understand aspects of the CFPG driving performance differences.Diagnostic performance was substantially reduced from discrete to complex CoA for conventional Doppler indices calculated from patient data, and by hypoplasia and/or long segment stenosis in simulations. In contrast, diagnostic indicators for the CFPG only modestly dropped for complex vs discrete CoA. Simulations revealed differences in performance due to inclusion of the Doppler velocity index and diastolic pressure half-time in the CFPG calculation. Conclusion: CFPG is less affected by aortic arch anomalies co-existing with CoA when compared to conventional Doppler indices.
RESUMO
<p>Several problems have been reported following coarctectomy, especially in cases involving long-segment coarctation (COA). Although residual COA, proximal arch kinking, and airway compression may occur after coarctectomy, avoiding the use of artificial materials provides a better chance for the subsequent growth of the aorta. We successfully performed a modified end-to-end anastomosis with subclavian flap aortoplasty for a two-month-old boy with COA. A two-month-old boy was admitted to our hospital for nocturnal tachypnea and a feeding disorder. The initial echocardiography showed a preductal long COA beyond the left subclavian artery. A perimembranous VSD, a patent foramen ovale, and a patent ductus arteriosus were also noted. The left ventricular function was mildly depressed with an ejection fraction of 59%. Enhanced CT revealed a long-segment COA with a length of 15 mm. The blood pressure gradient between the upper and lower limbs was 40 mmHg. The operation was performed at the age of 2 months. The 4th intercostal space was opened through a posterolateral left thoracotomy incision. The distal end of the isthmus was so ligated as to maintain blood perfusion to the lower body through the PDA. The arch was clamped between the left carotid and the left subclavian artery (LSCA). The LSCA and the isthmus were divided as distally as possible, and the two distal ends were longitudinally incised and sutured to each other in a side-to-side fashion using a 7-0 polypropylene continuous suture. After complete resection of the ductal tissue, a newly created distal arch was anastomosed to the descending aorta. The left ventricular ejection fraction was increased to 74% at discharge. Catheterizations 3 years after the surgery did not reveal any stenosis or deformity in the aorta at normal PA pressure. The patient has been doing well and is free of complications 7 years after the surgery. At present, end-to-end anastomosis and aortic arch advancement with or without cardiopulmonary bypass are widely used procedures for coarctectomy ; however, a modified end-to-end anastomosis is still a viable option for cases involving long-segment coarctation.</p>