Stress testing for comparison of synthetic patch aortoplasty with resection and end to end anastomosis for repair of coarctation in childhood

Ambulatory blood pressure in patients with occult recurrent coarctation of the aorta

The hypothesis that mild recurrent aortic obstruction produces subtle changes in ambulatory blood pressure was investigated by performing 24-hour monitoring on 11 postoperative coarctation patients. Patients (age 16.1 +/- 2.7 years) were compared with normal controls (age 15.7 +/- 2.5 years, n = 15). Surgery (end-to-end anastomosis) was performed at 6.0 +/- 1.0 years of age. There were no significant differences between patients and controls in terms of baseline blood pressure (right arm 123/78 +/- 4/3 mmHg versus 120/75 +/- 3/2 mmHg) or right leg systolic pressure (125 +/- 6 mmHg versus 123 +/- 4 mmHg). Of the 11 patients 8 had recoarctation by Doppler study (mean gradient 25.3 +/- 2.1 mmHg), 5 of 11 had a postexercise arm-leg pressure difference of > 30 mmHg, and 6 patients had aortic diameters at the site of surgery < 70% of the descending aortic diameter (by magnetic resonance imaging). There were no significant differences between the coarctation and control groups in terms of mean ambulatory systolic (125 +/- 3 mmHg versus 119 +/- 2 mmHg) or diastolic (69 +/- 2 mmHg versus 72 +/- 2 mmHg) pressures throughout the day. However, coarctation patients had a larger number of systolic pressures that exceeded the 95th percentile (18.2 +/- 5.6% versus 6.8 +/- 1.2%). These labile increases in systolic pressure correlated with residual coarctation (r = 0.642, p = 0.003). Ambulatory monitoring is a useful tool for detecting and monitoring subtle abnormalities of blood pressure control after coarctation repair.

Transsternal repair of coarctation and associated cardiac defects

Over a 13-year period, 20 infants and children underwent transsternal approach for repair of coarctation and associated cardiac defects. Fifteen patients (75%) were operated on in the last 6 years. Thirteen patients (group 1) had intracardiac shunts and 7 (group 2), intracardiac obstruction or valvular insufficiency. Group 1 had a mean age of 0.8 +/- 1.9 years versus 4 +/- 3 years for group 2 (p = 0.05). There were 12 patients (92%), 7 months old or less in group 1. Aortic arch hypoplasia was present in 6 patients in group 1. A large patent ductus arteriosus was present in 5 of these 6 patients versus no patent ductus arteriosus in patients without aortic arch hypoplasia (p = 0.006). The mean pulmonary blood flow to systemic blood flow ratio in group 1 was 3.8 +/- 2 and the mean right ventricular to left ventricular ratio, 0.8 +/- 0.2. The coarctation repair fell mostly into three types: side patch aortoplasty (8), ductal tissue excision and patch aortoplasty of the concavity of the aortic arch (6), and subclavian aortoplasty (4). There was one early death (5%) which was due to sepsis in a newborn. Another newborn who had subclavian aortoplasty needed a left carotid artery--descending aorta bypass conduit early because of aortic arch hypoplasia. All patients were followed to 12 years (mean follow-up, 4.3 +/- 3.5 years). There were no late deaths. Two patients had recurrent coarctation, 1 after an end-to-end repair and the other because of incomplete arch enlargement after a side patch aortoplasty.(ABSTRACT TRUNCATED AT 250 WORDS)

Left ventricular function in dogs 1 year after coarctectomy

Juxtaductal aortic coarctation was surgically created in beagle puppies at the age of 2 months and resected at the age of 10 months, after the development of good collateral circulation. Control dogs undergoing sham operations on each occasion were studied in the same environment. Cardiac catheterization was performed 1 year after the coarctectomy to evaluate the recovery of the heart. Cardiac output, heart rate, end-diastolic pressure, and Vmax were similar in both groups of seven dogs, but the systolic pressure gradient (SPG) over the operated area during isoproterenol infusion was significantly higher in the coarctectomized group, with a mean of 8.9 +/- 6.3 (SD) vs. 0.1 +/- 0.3 mmHg (p less than 0.05). The preejection period [PEP, 58 +/- 8 vs. 47 +/- 5 ms (p less than 0.01)], electromechanical delay [EMD, 18 +/- 3 vs. 13 +/- 3 ms (p less than 0.05)], and isometric contraction time [ICT, 39 +/- 7 vs. 32 +/- 4 ms (p less than 0.05)], were all significantly longer in the coarctation group after isoproterenol infusion. The results demonstrate that, even though cardiac output increased adequately during loading and mechanical pumping efficiency was preserved, excitation-contraction coupling was still prolonged. Thus, an anatomical successful coarctectomy, even at the age of 10 months, does not fully restore left ventricular function in dogs after chronic experimental coarctation.

Estimation of Doppler gradients at rest and during exercise in patients with recoarctation of the aorta

In patients with suspected recoarctation of the aorta the estimation of the pressure difference between the arms and legs is an important part of the examination. Because this difference is often augmented when the circulation is stressed by exercise, exercise tests are a useful part of the evaluation. Doppler echocardiography was used to estimate this pressure difference in 16 adult patients in whom simultaneous pressure and Doppler recordings were made both at rest and during exercise. There was a close correlation between the invasive peak instantaneous gradient and the Doppler gradient both at rest and during exercise. There was only a moderate correlation between the invasive peak to peak gradient and the Doppler gradient at rest and during exercise. Doppler echocardiography is recommended as an easy and accurate method of estimating the peak instantaneous gradient both at rest and during exercise in patients with suspected recoarctation.

Long-term follow-up of coarctation of the aorta repaired by patch angioplasty

The long-term complications of patch plasty repair for coarctation of the aorta were assessed retrospectively in 119 patients who were operated upon from 4 days to 13 years of age. There were 7 late deaths and 17 patients were lost to follow-up. Thus 95 patients were followed up for a minimum period of 3 years (mean 6.3 years). In addition, graded exercise tests were performed on 15 patients and 11 normal controls, measuring systolic blood pressure response and arm-leg blood pressure gradients. In this series, 16 patients (17%) were hypertensive, while 25 (26%) had a resting systolic arm-leg gradient greater than 20 mm Hg. Re-coarctation occurred more frequently when surgery had been undertaken under 1 month of age. Review of chest X-rays revealed calcification in the patch in 4 patients, one of whom subsequently went on to aneurysm formation. In a second child aneurysm formation was detected at repeat operation. Exercise tests showed a significantly higher systolic arm pressure in patients (mean: 165.3 mm Hg) when compared to controls (mean: 139.2 mm Hg) (P = 0.017) and a significant increase in arm-leg systolic gradient viz. 36 and 5.9 mm Hg, respectively (P = 0.0016). A good correlation was found between the systolic arm pressure and the systolic arm-leg gradient after exercise (r = 0.822; P = 0.0001). We conclude that the most important long-term complication following an aortic patch plasty, is re-stenosis. The development of an aneurysm was observed only twice. We believe that this apparently rare occurrence, as assessed on chest radiographs; is related to the young age (53% under 1 year) at which the repairs were carried out. Another possible reason may be that the follow-up period is not yet long enough.

Exercise in children before and after coarctectomy: hemodynamic, echocardiographic, and biochemical assessment

After repair of coarctation of the aorta, some patients with normal blood pressure at rest have an exaggerated hypertensive response to activity. Blood pressure response to exercise was studied in 15 children, aged 5 to 15 years, prior to and at periods up to 6 months following coarctectomy. Preoperatively, 11 of 15 children had systolic hypertension at rest and 12 of 15 after exercise. After surgery, only one child had mild systolic hypertension at rest, whereas exercise-induced hypertension persisted in 33% of patients (all older than 10 years). Exercise plasma renin activity was elevated preoperatively but normalized following surgery. No significant difference was seen in resting and exercise plasma catecholamine levels measured before and after surgery. Over the follow-up period of 6 months, echocardiographic evidence of left ventricular hypertrophy regressed in the younger patients but not in the older patients with exercise-induced hypertension. Exercise testing defines a subgroup of patients with exercise-induced hypertension evident soon after surgery. Structural upper segment arterial vessel wall changes in the older patient may explain these observations.

Changing trends in the surgical treatment of coarctation of the aorta

From 1974 through 1983, 107 patients 4 days to 27 years old underwent 115 operations for treatment of coarctation of the aorta. Thirty-two patients were infants (1 year old or younger), and 28 of them were newborns. All newborns were seen with congestive heart failure. Seventy-one patients were seen with hypertension. Associated anomalies were present in 72 patients (67%). Resection was performed in 48 patients, patch aortoplasty in 16, bypass of the coarcted segment in 15, and left subclavian artery flap angioplasty (LSAFA) in 36. Ligation of a patent ductus arteriosus was simultaneously performed in 28 patients and pulmonary artery banding, in 4. Follow-up was 6 months to 9.2 years. There was a significant difference in aortic cross-clamp time between 26 patients who had resection (37.9 +/- 12.9 minutes) (mean +/- standard deviation) and 32 patients who had LSAFA (22.9 +/- 7.7 minutes) (p less than 0.05). Six patients died within thirty days after operation; 5 of them had resection, and 1 had bypass. Major postoperative complications included bleeding requiring exploration in 3 patients (2 after resection and 1 after LSAFA) and paraplegia in 1 patient after reoperation (resection) for recurrent coarctation 3 years after patch aortoplasty. Paradoxical hypertension was observed in 13 patients, and sustained systemic postoperative hypertension developed in 11 after effective repair of coarctation. There was no significant difference in early postoperative arm-leg pressure gradients between the types of operation or the various age groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Repair of aortic coarctation in infants: experience with an intraluminal shunt

From 1962 to mid-1984, 63 infants underwent coarctation repair. Cardiac defects were present in 46 (73%). Repair was by subclavian aortoplasty in 35 patients, resection and end-to-end anastomosis in 19, and other techniques in 6. Three patients died before the repair was completed. In 15 patients, an intraluminal shunt was used during subclavian aortoplasty. Prostaglandin E1 (PGE1) was infused in 9 patients. Early (thirty-day) mortality was 16% (10 patients): 4 patients who underwent end-to-end anastomosis; 3 during attempted end-to-end anastomosis; 2 who received bypass grafts; and 1 who had subclavian aortoplasty without a shunt. None of the 15 patients who had subclavian aortoplasty with a shunt died. There were no early deaths among the last 25 patients seen. One patient who underwent subclavian aortoplasty without a shunt is paraplegic. There were 10 late deaths among the 53 patients followed from 1 month to 12 years (mean, 3 years). Arm-leg pressure gradients of 20 mm Hg or greater were found in 4 of the patients who had end-to-end anastomosis but not in any of the patients who had subclavian aortoplasty. Improved results of coarctation repair in infants in this study were attributed to PGE1, subclavian aortoplasty, and use of an intraluminal shunt.