Residual Coarctation Research Articles

Surgery for coarctation of the aorta in infants weighing less than 2 kg

Background. Low- and very low-birth weight infants are now candidates for reparative cardiac surgery. Outcomes after coarctation repair have not been characterized in this patient population. Methods. We performed a retrospective review of 18 consecutive neonates less than 2 kg who underwent repair of aortic coarctation between August 1990 and December 1999. Results. Median weight was 1,330 g, and median gestational age was 31 weeks. A ventricular septal defect was present in 5 patients, and Shone’s complex in 4. Sixteen patients had resection and end-to-end anastomosis, and 2 had resection and subclavian flap. Median clamp time was 15.5 minutes. One patient died during hospitalization. Two patients died late postoperatively (5-year estimated survival 80%). Mean follow-up was 28.5 months. Eight patients (44%) had a residual or recurrent coarctation, 5 underwent balloon dilation, and 3 underwent reoperation. Freedom from reintervention for recoarctation was 60% at 5 years. Shone’s complex or a hypoplastic arch was an independent risk factor for decreased survival ( p < 0.001). Very low birth weight was a multivariate predictor for increased risk of recoarctation ( p = 0.01). Conclusions. Coarctation repair in less than 2-kg premature non-Shone’s infants can be performed with a low mortality. The rate of recoarctation is higher in the very low-birth weight infants, but can be managed with low risk.

Balloon dilation for aortic recoarctation: morphology at the site of dilation and long-term efficacy.

We undertook this study to assess the immediate and long-term outcome of balloon angioplasty performed for recurrent or residual coarctation of the aorta, and to assess the changes in the vessel wall caused by this procedure. Clinical, echocardiographic, angiographic and hemodynamic data from 71 patients who underwent balloon angioplasty for recoarctation between January 1987 and January 1998 were analysed retrospectively. Angioplasty was performed after a median of 82.6 months (range 1.4 mo-20.9 y, mean 88.5 mo) following surgery for coarctation. Mean systolic pressure gradients were reduced from 27 +/- 15 mmHg to 11 +/- 11 mmHg after angioplasty (p < 0.0001). The mean diameter at the site of recoarctation increased from 5.5 +/- 2.5 to 7.5 +/- 2.7 mm (p < 0.0001). Outpouchings of contrast agents, indicating the disruption of the inner layers of the vessel wall, were defined as extravasations. They were observed in one-quarter of the angiograms performed immediately after the intervention. Immediate success of angioplasty was achieved in 71%, and persisted in 69% of patients during long-term follow up. The main determinant for immediate success was the age at the time of the procedure (p < 0.05), while the main determinant for long-term success was the increase achieved in diameter. Extravasations did not progress to aneurysms, neither acutely nor during echocardiographic follow-up studies. For further follow-up, more sensitive imaging techniques will be necessary to delineate the morphology of the site of extravasation observed immediately after angioplasty.

Misrepresentation of left ventricular contractile function by endocardial indexes: Clinical implications after coarctation repair

Background Endocardial function indexes overestimate myocardial fiber shortening, a geometric effect proportional to wall thickness. We hypothesized that elevated endocardial indexes of left ventricular contractile function after repair of isolated coarctation of the aorta could be related to this effect. Methods Chamber dimensions and wall thickness were measured from 59 echocardiograms in 57 patients aged 1.2 to 32 years, 8.5 ± 5.6 years after coarctation repair, and in 305 normal controls aged 1 to 35 years. Midwall and endocardial shortening indexes and end-systolic fiber stress were calculated. The stress-velocity index (SVI), a load-independent index of contractility, was derived from these variables. All values were expressed as z scores. Results After coarctation repair, the midwall-derived SVI was elevated, but significantly less so than the endocardial-derived SVI (0.6 ± 1.6 vs 1.3 ± 2.6; P = .01). The endocardial-derived SVI correlated with the end-systolic thickness/dimension ratio (P < .0001), but the midwall-derived SVI did not. There was no linear relation between the midwall-derived SVI and the residual blood pressure gradient. The mean midwall-derived SVI was higher compared with the normal population in those with a minor residual blood pressure gradient (≤15 mm Hg) and in those with more significant obstruction (>15 mm Hg), but this achieved statistical significance only in the latter group (0.5 ± 1.6, P = .08; and 0.8 ± 1.7, P = .03, respectively). Conclusions Endocardial indexes of function and contractility overestimate fiber shortening after coarctation repair. Nevertheless, midwall shortening indexes demonstrate enhanced contractility, particularly in those with residual coarctation.

Early results and medium-term follow-up of stent implantation for mild residual or recurrent aortic coarctation

Background Optimal timing and mode of treatment for patients with aortic coarctation remains controversial, particularly when the degree of obstruction is mild. Surgery, balloon dilatation, and stent implantation have all proven effective in the treatment of moderate or severe obstruction. In this report, we describe the use of stents to treat coarctation in a heterogeneous population, including patients with relatively mild obstruction. Methods Retrospectively, we studied the results of stent implantation in 33 patients, children and young adults, who underwent catheterization for treatment of coarctation. Patients with isolated coarctation, as well as those with associated cardiac defects, were included. The median systolic pressure gradient of our patients was 25 mm Hg. Results Patients had an acute decrease in systolic blood pressure gradient (25 mm Hg to 5 mm Hg, P <.001) and an increase in lumen diameter (8 mm to 13 mm, P <.001). When 16 patients were recatheterized during the follow-up period, gradients remained decreased (30 mm Hg to 14 mm Hg, P <.001) compared with prestent values. Ventricular end-diastolic pressure, which was increased in 82% of patients at the time of initial catheterization, decreased from 17 mm Hg to 14 mm Hg (P =.002). Although the procedure was generally safe, serious complications did occur. Conclusions Stent implantation represents a therapeutic option that can safely and effectively reduce gradient in challenging patients with mild postoperative coarctation. Furthermore, our data suggest that aortic obstruction often coexists with ventricular diastolic dysfunction in these patients and that relief of obstruction may play a role in improvement of function. (Am Heart J 2000;139:1054-60.)

Repair of coarctation of the aorta during infancy minimizes the risk of late hypertension

Background. Recent surgical reports on coarctation of the aorta have primarily focused on the relative merits of various operative techniques. However, appropriate timing for elective repair remains unclear. Methods. In a retrospective analysis we examined the surgical outcomes in 176 consecutive patients undergoing repair of coarctation of the aorta in our institution over a 25-year period. Ninety-nine percent of the patients had follow-up for a median of 7.5 years. Results. A total of 13 patients have died (7.4% overall mortality). Nine of these patients had associated complex intracardiac anomalies. There was no mortality in the 113 patients with isolated coarctation. Residual or recurrent coarctation occurred in 27 patients (15.3%). The age at operation and the type of surgical repair did not have an effect on the incidence of recurrence. Persistent or late hypertension was identified in 18 of the 107 patients who have been followed up for more than 5 years (16.8%). A total of 48 patients operated on during infancy have been followed up for more than 5 years. Only 2 have developed late hypertension (4.2%). Both of these patients had recurrence. In contrast, 16 of the 59 patients operated on after a year of age had late hypertension (27.1%). Conclusions. To minimize the risk of persistent hypertension, elective repair of coarctation should be performed within the first year of life.

Coarctation Repair: Modification of End-to-End Anastomosis With Subclavian Flap Angioplasty

Background. Subclavian angioplasty and resection and end-to-end anastomosis for coarctation repair carry a substantial risk of recurrence of coarctation. The combined technique using both these methods has shown good results but requires a longer period of continuous cross-clamping of the aorta. Methods. A modified technique using intermittent cross-clamping with a period of reperfusion between cross-clamping periods was used. After the end-to-end anastomosis the clamps are released for 10 minutes and reapplied to do the subclavian angioplasty. Between 1991 and 1996 this was done in 26 infants (mean age, 5 weeks; range, 1 day to 6 months; median, 3 weeks). Mean weight was 3.85 kg (range, 1.5 to 8.4 kg). Mean length of follow-up was 23 months. Twenty-two patients (85%) had associated anomalies, excluding patent ductus arteriosus, and 5 patients (19%) had another procedure performed at the same time. Results. There was no mortality. The mean echocardiographic gradient was 4 mm Hg in the immediate postoperative period and 2.9 mm Hg during follow-up. Residual or recurrent coarctation as detected by significant echocardiography or blood pressure gradient did not develop in any infant. Conclusions. This modified technique of anastomosis is an effective way of relieving coarctation with excellent intermediate-term results.

Aortic coarctation, multiple ventricular septal defects, and anomalous coronary artery arising from the right pulmonary artery

The literature reveals no reports of a left coronary artery arising from the right pulmonary artery in association with aortic coarctation and multiple ventricular septal defects. The patient we describe here died of left myocardial infarction after palliative operation because this defect was unanticipated. Case report. The patient was admitted at the age of 12 days with a diagnosis of aortic coarctation and multiple ventricular septal defects. She had classic signs of aortic coarctation and predominantly left-sided heart failure, which responded partially to prostaglandin E1 and diuretics. Chest radiography revealed severe cardiomegaly and symmetrically plethoric lungs. The electrocardiogram showed sinus rhythm at 140 beats/min, right ventricular hypertrophy, and no signs of myocardial ischemia. Echocardiography demonstrated an aortic coarctation with long, severe hypoplasia of the arch, a large ductus arteriosus, and multiple ventricular septal defects. The left ventricle was neither hypokinetic nor hypoplastic. No coexisting mitral regurgitation was documented. There was also a left superior caval vein draining into the coronary sinus and a large ostium secundum–type atrial septal defect. The patient underwent pulmonary artery banding, division of the ductus arteriosus, and aortic coartectomy. Within 2 hours of the patient’s return to the intensive care unit, her condition deteriorated rapidly and dramatically, with a global but predominantly left-sided intractable heart failure, complete atrioventricular block, and cardiogenic shock. The postoperative electrocardiogram revealed signs of severe myocardial anterolateral ischemia and necrosis and a third-degree atrioventricular block (Fig. 1). Creatine kinase had increased to 530 U/L (normal range 15 to 100 U/L) with an MB fraction of 365 U/L (68%), representing a significant acute myocardial necrotic phenomenon. Postoperative cross-sectional echocardiography visualized a mildly dilated and severely hypokinetic left ventricle (less than 10% of shortening fraction) with severe impairment of diastolic function. The pulmonary artery banding was adequate, and there was no residual aortic coarctation. The right coronary artery was predominant, and the left coronary artery’s origin was not seen from the corresponding aortic Valsalva sinus. This raised suspicion of an anomalous left coronary artery arising from the pulmonary artery, which would provide an explanation for the myocardial infarction. Unfortunately, the child’s deteriorating condition did not allow performance of any further investigations. Despite maximum hemodynamic support and intravascular cardiac pacing with a 5F bipolar balloon pacing electrode (USCI International, BARD, C.R. Bard Ireland Ltd., Galway, Ireland), she died on the third postoperative day. Postmortem examination. The heart weighed 30 gm. There was, as expected, an abnormal left superior caval vein draining into the coronary sinus, a large ostium secundum–type atrial septal defect, and one large perimembranous and multiple muscular ventricular septal defects. The right ventricle was predominant, and the left one was small but not hypoplastic. Necrotic patches, confirmed by histologic analysis, were evident in the left anterolateral wall. The endocardium did not exhibit fibroelastosis. The aortic coarctation was well repaired, and the pulmonary banding was found to be in place. A tortuous, dilated right predominant coronary artery originated from the right aortic Valsalva sinus. The left coronary artery arose from the posterior right pulmonary artery wall immediately after the pulmonary bifurcation and followed a tortuous course over the anterior interventricular groove (Fig. 2). Discussion. Within the wide variety of left coronary anomalous origin, left coronary artery arising from the right pulmonary artery is extremely uncommon. The chief reason for this report, however, is the association of this origin with lesions producing high pulmonary flow, with consequent lack of clinical data suggesting such a diagnosis. Many factors led to misdiagnosis. First, this finding is not classically anticipated in cases of ventricular septal defects and aortic coarctation. Second, the left-to-right shunt provided normal perfusion to the aberrant coronary artery before the operation. Until palliation, this child’s left coronary blood flow was normal, and so were the left ventricular myocardial perfusion and oxygenation, because the pulmonary and aortic pressures and saturations were similar. The fall in pulmonary pressure to a low level after the pulmonary artery banding was therefore accompanied by a decline in the left coronary flow, with drops in coronary perfusion pressure and oxygen saturation leading to left ventricular ischemia and myocardial infarction. A similar physiopathologic condition related to closure of From the Department of Pediatric Cardiac Surgery, Centre Medico-Chirurgical de la Porte de Choisy, and the Department of Pediatric Cardiology, Institut de Puericulture de Paris, Paris, France.

Cardiological and general health status in preschool- and school-age children after neonatal arterial switch operation.

Cardiological and general health status 3-9 years after neonatal arterial switch operation for transposition of the great arteries should be evaluated by non-invasive methods. A total of 77 unselected children with intact ventricular septum (75.3%) or ventricular septal defect (24.7%) without or with aortic isthmic stenosis (5.2%) were prospectively examined 3.2-9.4 years (5.4 +/- 1.6) after neonatal switch. Clinical pediatric and cardiological examination, standard and 24 h Holter electrocardiogram, M-mode, 2D-, Doppler and colour Doppler echocardiography were performed. Outcome data were compared to published normals. Reoperation rate was 2.6%, 96.1% were without limitation of physical activity and 98.7% without medication. Compared to normals, growth was adequate, weight and head circumference were slightly reduced. After median sternotomy, 23.4% had abnormal thoracic configuration (16.9% asymmetry, 6.5% funnel chest). ECG and Holter: 93.5% were in sinus, 6.5% in ectopic atrial or junctional rhythm. Incidence of complete right bundle branch block was 15.8% in patients with ventricular septal defect and 5.2% in those without. Ischemic ST-T changes during exercise due to coronary artery occlusion and evidence of old myocardial infarction were found in 1 patient (1.3%) each. Occasional atrial ectopy was found in 27.4%, ventricular ectopy in 15.3%: occasional in 12.5% and frequent (> 30/h) in 2.8% presenting bigemini, couplets and short runs of ventricular tachycardia at rest and during exercise. Echocardiography: Left ventricular function was normal in all. Endsystolic diameter of neoaortic valve annulus was beyond 90% confidence interval for controls in 79.2%, neoaortic root diameter in 100%. Mild aortic insufficiency was seen in 10.4%. No correlation was found between aortic insufficiency and aortic dilatation. Neoaortic stenosis was not seen, mild residual coarctation after end-to-end-anastomosis was found in 2.6%, native coarctation corrected later on in 1.3%. Supravalvular pulmonary stenosis was seen in 29.9% (19.5% trivial, 7.8% mild, 2.6% moderate), mild subvalvular pulmonary stenosis in 1.3%, pulmonary insufficiency in 2.6%. The study confirms good midterm results after neonatal arterial switch operation for transposition with or without ventricular septal defect. Long-term observation is necessary to assess rhythm, coronary artery and myocardial function as well as development of neo-aorta and pulmonary artery system.

Echocardiographic evaluation of systolic and diastolic function in postoperative coarctation patients.

Postoperative coarctation (CoA) patients are often found to have signs of persistent myocardial dysfunction. M-mode echocardiography was performed to study left ventricular (LV) size, mass, and systolic function and Doppler ultrasonography to study LV filling and flow velocity in the LV outflow tract and aorta in 28 "healthy" postoperative CoA patients (5-21 years) and 28 age- and sex-matched controls. The early (E) and late (A) diastolic transmitral velocities were significantly higher in the patient group than in the controls (p < 0.05). Other diastolic parameters (isovolumic relaxation time, E/A ratio, and deceleration time of the early diastolic velocity) were similar in the two groups (p = NS). The left atrial diameter, LV wall average, end-diastolic diameter of the LV and LV mass were higher in the patients than controls (p < 0.05). The patients also had a higher stroke volume, cardiac output, and cardiac index than the controls (p < 0.01). The fractional shortening was similar in the two groups (p = NS). Blood flow velocities in both the LV outflow tract and aorta were higher in the patients than the controls (p < 0.0002). We found LV hypertrophy with signs of a hyperdynamic circulation (increased cardiac index and stroke volume) in our patients. An increase in A is associated with LV hypertrophy and seems to be a sensitive marker of diastolic abnormality. The rise in E is paradoxical but has been seen in other studies. The increased blood flow velocity in the LV outflow tract suggests obstruction to LV outflow and increased flow in the descending aorta is due to residual coarctation.

Quantitative echocardiographic analysis of the aortic arch predicts outcome of balloon angioplasty of native coarctation of the aorta.

The use of balloon angioplasty for treatment of native aortic coarctation is controversial. Cineangiographic data suggest that aortic arch hypoplasia and isthmic narrowing are associated with angioplasty failure. This study of echocardiographic measurements of preangioplasty aortic arch morphology was performed to identify potential anatomic predictors of outcome noninvasively. The preangioplasty echocardiograms of 105 patients 3 days to 17 years old with native coarctation of the aorta were analyzed off-line. Angioplasty was considered successful if the residual coarctation gradient was < 20 mm Hg and no intervention for recoarctation occurred. Univariate analysis identified young age at angioplasty, presence of a patent ductus arteriosus, and the diameters of the aortic isthmus, distal transverse arch, and aortic valve as predictors of early and late outcomes. Multivariate analysis showed that the preangioplasty aortic isthmus z value was the best independent predictor of outcome, eliminating the effect on outcome of age and associated cardiac defects. An isthmus z value < or = -2.16 predicted early failure with 91% sensitivity and 85% specificity. Kaplan-Meier analysis demonstrated that 90% of patients with an isthmus z value > -1.0 remained free of recoarctation at late follow-up, whereas 89% of patients with a preangioplasty isthmus z value < or = -2.0 developed recoarctation within 36 months. Echocardiographic measurements of the aortic arch predict both early and late outcomes of balloon angioplasty for native aortic coarctation, and the preangioplasty aortic isthmus z value was the best independent predictor. Quantitative aortic arch analysis may improve selection of angioplasty candidates who are likely to benefit from the procedure.

Taussig-Bing anomaly: Arterial switch versus Kawashima intraventricular repair

Current corrective surgical approaches for the Taussig-Bing heart include arterial switch with ventricular septal defect (VSD) closure and intraventricular repair as described by Kawashima. Between 1983 and 1994, 20 children underwent intracardiac repair of Taussig-Bing anomaly. Mean age at operation was 17 months (range, 1 week to 9 years). Prior palliation included pulmonary artery band (15) with coarctation repair (8) and atrial septectomy (1). Arterial switch with VSD closure was performed in 16 patients, 10 with anteroposterior great arteries. Kawashima repair was performed in 4 patients, all with side-by-side great arteries. After arterial switch, there was one operative death (6.2%) due to myocardial ischemia and three late deaths (18.7%) due to pulmonary hypertension, gastrointestinal bleeding, and acute lymphocytic leukemia. In the Kawashima repair group there have been no deaths. After arterial switch, 9 patients underwent 11 reoperations for residual coarctation (3), residual pulmonary artery stenosis (2), aortic valve replacement, aortic valvuloplasty, unrecognized VSD, mitral valvuloplasty, mediastinitis, and pacemaker insertion. After Kawashima repair, 1 patient underwent reoperation for baffle stenosis and 1 for an unrecognized VSD. For children with Taussig-Bing anomaly, the Kawashima intraventricular repair (for side-by-side great arteries) preserves the native aortic valve and avoids coronary dissection. The arterial switch operation with VSD closure can be applied without ventriculotomy to all great artery relationships and allows neonatal repair with or without concomitant coarctation repair. Both techniques yield excellent early and intermediate-term results despite the high rates of prerepair palliation and postrepair reoperation for both groups.

Surgical Repair of Coarctation of the Aorta in Neonates: Factors Affecting Early Mortality and Re-Coarctation

Between October 1979 and January 1993, 85 Chinese neonates in Hong Kong underwent surgical repair for coarctation of the aorta. Their mean(s.e.) age and body weight at operation was 15.6(8.5) days and 3.06(0.56) kg, respectively. Simple coarctation was present in 17 babies, while 36 had additional ventricular septal defect and 31 had associated major complex intracardiac lesions. Subclavian flap aortoplasty was performed in 56 babies, resection with end-to-end anastomosis in 18 and aortoplasty with the use of a GORETEX patch in 11. The overall early mortality rate was 16.5%. To identify risk factors for early operative mortality. various clinical variables, surgical options, associated heart lesions and dimensions of the aortic arch at different sites for each patient were reviewed. Univariate analysis identified statistically significant differences between the survivors and non-survivors for the following factors: preoperative body-weight, arterial pH and base excess, serum urea and creatinine levels. Stepwise logistic regression further distinguished serum creatinine levels and the period of operation as two significant risk factors. Contrary to previous reports, the dimensions of the aortic arch and type of surgery did not affect early operative mortality. Among the 71 hospital survivors followed for 38.2(38) months, residual or recurrent coarctation of the aorta was detected in 12(17%). The different surgical operations were not related to the incidence of late complication. The size of the distal transverse arch, however, was different ( P= 0.05) in those who did and did not develop aortic sequela. Successful balloon angioplasty was subsequently performed in 11 patients. In an era of echocardiography with prenatal diagnosis and therapeutic catheterization, early recognition of the disease with prompt prostaglandin infusion should prevent collapse of the baby, thus avoiding renal impairment and severe metabolic acidosis. Balloon angioplasty would offer a simple effective treatment for patients who developed aortic re-coarctation.

Surgical repair of coarctation of the aorta in neonates: factors affecting early mortality and re-coarctation

Between October 1979 and January 1993, 85 Chinese neonates in Hong Kong underwent surgical repair for coarctation of the aorta. Their mean(s.e.) age and body weight at operation was 15.6(8.5) days and 3.06(0.56) kg, respectively. Simple coarctation was present in 17 babies, while 36 had additional ventricular septal defect and 31 had associated major complex intracardiac lesions. Subclavian flap aortoplasty was performed in 56 babies, resection with end-to-end anastomosis in 18 and aortoplasty with the use of a GORETEX patch in 11. The overall early mortality rate was 16.5%. To identify risk factors for early operative mortality, various clinical variables, surgical options, associated heart lesions and dimensions of the aortic arch at different sites for each patient were reviewed. Univariate analysis identified statistically significant differences between the survivors and non-survivors for the following factors: preoperative body-weight, arterial pH and base excess, serum urea and creatinine levels. Stepwise logistic regression further distinguished serum creatinine levels and the period of operation as two significant risk factors. Contrary to previous reports, the dimensions of the aortic arch and type of surgery did not affect early operative mortality. Among the 71 hospital survivors followed for 38.2(38) months, residual or recurrent coarctation of the aorta was detected in 12(17%). The different surgical operations were not related to the incidence of late complication. The size of the distal transverse arch, however, was different ( P = 0.05) in those who did and did not develop aortic sequela. Successful balloon angioplasty was subsequently performed in 11 patients. In an era of echocardiography with prenatal diagnosis and therapeutic catheterization, early recognition of the disease with prompt prostaglandin infusion should prevent collapse of the baby, thus avoiding renal impairment and severe metabolic acidosis. Balloon angioplasty would offer a simple effective treatment for patients who developed aortic re-coarctation.

Balloon angioplasty for postoperative recurrent coarctation of the aorta.

Surgical repair for recurrent or residual postoperative coarctation of the aorta is associated with some morbidity, mortality, and an incidence of recurrent coarctation that may be as high as 20%. Balloon angioplasty for recurrent or residual postoperative coarctation has become the standard treatment of choice for this condition. In this article, we review the protocol we use, and the acute and long-term results of this procedure. Since 1983, over 400 patients have undergone balloon angioplasty for recurrent coarctation with excellent immediate relief of the gradient and improvement in the diameter. On long-term follow-up, the majority of these patients enjoyed a lasting beneficial effect of the balloon angioplasty. We discuss the future use of stents for selected patients who are not amenable or failed balloon angioplasty of recurrent or residual postoperative coarctation.

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.

Coarctation of the Aorta

The clinical evaluation and management of the patient with coarctation of the aorta continues to evolve. Traditional imaging evaluation by plain film chest radiography, barium esophagography, and arteriography with pressure measurements across the coarctation has been largely supplanted by Doppler echocardiography and magnetic resonance imaging (MRI). The complications of surgery and balloon angioplasty, including residual or recurrent coarctation and aneurysm, can also be evaluated noninvasively by echocardiography and MRI. Chest radiography continues to play an important role in "first discovery" imaging in asymptomatic patients.

Oscillometric Blood Pressures in the Arm, Thigh, and Calf in Healthy Children and Those With Aortic Coarctation

Comparing blood pressure (BP) obtained in the arm with that obtained in the thigh or calf is important in the diagnosis of aortic coarctation. However, normative mean and range of differences in BP between the arm and lower extremity sites are not available for normal children. It is also not known how accurately the differences in BP between the arm and the lower extremity sites predict the pulsed Doppler estimation of systolic pressure (SP) gradient across an aortic coarctation. To resolve these questions, the authors obtained two BP measurements by an oscillometric (Dinamap) method in the arm, thigh, and calf in 74 healthy children aged 4 to 16 years. Oscillometric BP was also obtained in 21 children aged 3 to 17 years with preoperative or postoperative aortic coarctation and BP gradients were compared with that estimated by the pulsed Doppler method. Overall, SP was higher in the thigh and calf than in the arm. The gradients in SP expressed as arm SP minus calf SP [S(A-C)] and arm SP minus thigh SP [S(A-T)] were significantly greater in children 4 through 8 years old than in those 9 to 16 years old. The S(A-C) was -9.3 (+/- 7.4 SD) mm Hg in the 4- through 8-year group and -5.0 (+/- 6.9 SD) mm Hg in the 9- to 16-year group. The S(A-T) was -7.1 (+/- 6.8 SD) mm Hg in the 4- through 8-year group and -2.4 (+/- 7.7 SD) mm Hg in the 9- to 16-year group.(ABSTRACT TRUNCATED AT 250 WORDS)

Doppler evaluation of femoral arteries in children after aortic balloon valvuloplasty or coarctation balloon angioplasty.

To assess long-term femoral artery complications after aortic balloon valvuloplasty or coarctation balloon angioplasty, we examined 19 children who were 3 weeks to 21 years old (mean 7.6 years) at the time of catheterization. Two-dimensional and Doppler echocardiographic examinations of the common, superficial, and deep femoral arteries were performed at an average of 2.0 years after balloon dilatation. Pulsatility index (PI) was calculated as the maximum velocity minus the minimum velocity divided by the mean velocity. No patient was suspected clinically of having peripheral arterial disease prior to the echocardiographic examination. Fourteen patients had normal femoral arteries. Of these, 10 had normal two-dimensional and Doppler echocardiographic examinations of both femoral arteries. These patients had triphasic flow patterns (forward in systole, reverse in early diastole, forward in middiastole) and Pls of 3.7-41.6 (mean 9.5). Four of the 14 normal patients had abnormal pulsed Doppler examinations showing continuous forward flow and low Pls (1.7-3.5) reflecting residual coarctation (10-30 mmHg gradients). Five patients had abnormal femoral arteries. Of these, two had no visible obstruction by two-dimensional echocardiography and color-flow imaging but had abnormal pulsed Doppler patterns (continuous forward flow and low Pls of 2.5 and 2.9) only on the side of the balloon catheter insertion. Three of the five abnormal patients had visible obstructions by two-dimensional echocardiography and color-flow imaging and had abnormal pulsed Doppler patterns (continuous forward flow and low Pls from 1.1-3.6).(ABSTRACT TRUNCATED AT 250 WORDS)

Increased stiffness and persistent narrowing of the aorta after successful repair of coarctation of the aorta: Relationship to left ventricular mass and blood pressure at rest and with exercise

Fifteen children and adolescents who had repair of coarctation of the aorta before age 15, who were not hypertensive at rest, and who had resting arm-leg blood pressure gradients of <20 mm Hg underwent noninvasive evaluation of left ventricular structure and function, aortic stiffness, and residual coarctation as well as bicycle exercise testing. These results were compared with those in 15 age- and sex-matched control subjects. The mean resting age-related systolic blood pressure percentiles (63% versus 46%), transverse aortic stiffness measured by the elastic modulus (Ep) (42.1 versus 23.2 kPa), stiffness index beta (β) (3.66 versus 2.17), echocardiographic left ventricular fractional shortening (0.42 versus 0.36), left ventricular mass index (99.3 versus 81.0 gm/m 2), maximum exercise right arm systolic blood pressure (173 versus 156 mm Hg), and exercise arm-leg blood pressure gradient (35 versus 6 mm Hg) were significantly increased in the coarctectomy patients compared with controls. Univariate correlations in the coarctectomy group showed significant relationships of residual aortic narrowing with left ventricular mass index ( r = 0.68, p < 0.01) and resting systolic blood pressure percentile for age ( r = 0.55, p < 0.05). Residual aortic narrowing did not significantly correlate with aortic stiffness, resting blood pressure gradient, or exercise blood pressure gradient. Neither left ventricular mass index nor resting systolic blood pressure percentile significantly correlated with age of repair or years after repair. These results demonstrate persistent abnormalities in aortic stiffness and left ventricular mass and function after successful repair of coarctation of the aorta in childhood and adolescence. Mild degrees of residual aortic narrowing may affect resting blood pressure and left ventricular mass. Elevated blood pressure and blood pressure gradients between upper and lower extremities during exercise may be a reflection of increased arterial stiffness in the upper body as well as mild persistent coarctation.

End-to-end repair of aortic coarctation using absorbable polydioxanone suture

Based on previous laboratory work, we have used polydioxanone absorbable suture in a variety of vascular and cardiac repairs in pediatric patients. However, some investigators have expressed concern about the potential for aneurysm formation at the anastomotic site. Between March 1983 and June 1989, 15 patients (7 male, 8 female) aged 2.5 months to 9.2 years (mean, 3.7 years) had resection of coarctation of the aorta and end-to-end anastomosis with polydioxanone absorbable suture. Thirteen patients have returned for routine postoperative evaluation, the follow-up time ranging from 11 to 49 months (mean, 23 months). Noninvasive two-dimensional, pulsed-wave Doppler and color echocardiography and magnetic resonance imaging studies demonstrated good anatomical repair and no anastomotic aneurysm formation or residual coarctation of the aorta in any patient after end-to-end anastomosis with polydioxanone. In summary, this intermediate follow-up study has revealed no vascular complications related to the repair of coarctation with absorbable polydioxanone suture.