Ingo Dähnert

Transcatheter closure as standard treatment for most interatrial defects: experience in 200 patients treated with the Amplatzer Septal Occluder.

To judge whether an Amplatzer Septal Occluder can be used as standard therapy instead of surgery for closure of atrial septal defects we report our experiences in 200 patients. Of these patients, 127 had an atrial septal defect with haemodynamically significant left-to-right shunt, 68 patients a persistent oval foramen after presumed paradoxical embolism, and 5 had a fenestration after Fontan-repair. Mean age was 29.8 years (0.8 to 77.7 years). Body weight ranged from 6.9 to 120.0 kg (mean 51.5 kg). After diagnostic cardiac catheterization, and balloon-sizing of the defect, we implanted Amplatzer Septal Occluders with stents of 4 to 28 mm diameter. Follow-up studies were obtained after 48 hours, and one, six, and twelve months. Transcatheter closure of the atrial septal defect proved successful in all without any relevant residual shunts. In particular, complete closure was achieved in all patients after presumed paradoxical embolism. The mean period of follow-up is 9.5 months, with a range from 0.4 to 23.5 months, giving a total of 1898 patient months. The occlusion rate after three month was 98.1%. A trivial haemodynamically insignificant residual shunt remained in 1.9% of the patients. Fluoroscopy times ranged from 0 to 43.5 minutes, with a median of 8.7 minutes. The excellent results in the short and medium term in children and adults have resulted in using this device routinely at the present time for closure of central atrial septal defects up to a diameter of 28 mm. Final judgement, however, is only possible after long-term follow-up.

Peritoneal dialysis after infant open heart surgery: observations in 27 patients

BACKGROUND The role of peritoneal dialysis (PD) in the management of infants after heart operation is under discussion. The aim of this study was to investigate the effect of PD on fluid balance and outcome. METHODS Twenty-seven (33%) of 81 consecutive infants who underwent heart operation required PD. In 22 patients (81%), PD was started prophylactically at the end of the operation. We recorded hemodynamic data and fluid balance. Patients experiencing acute renal failure (ARF) were compared with the remaining infants. RESULTS Eleven of 81 patients (14%) experienced ARF; 3 of them died (4% of all patients undergoing operation, 27% of those with ARF). Complications of PD, present in 33%, were transitory and of minor significance. Patients with ARF had decreased cardiac function compared with those without ARF but similar fluid balance. CONCLUSIONS Peritoneal dialysis is an effective and safe method for the treatment of ARF in infants after open heart operation. As PD is helpful in modulating postoperative fluid balance, prophylactic use of PD can be recommended for selected patients who are at risk for low cardiac output syndrome.

Optimal conduit size for extracardiac Fontan operation

BACKGROUND Lack of conduit growth potential and thrombogenicity are the main drawbacks of the extracardiac Fontan operation (ECFO). Optimal size of the conduit according to the patients age and inferior vena cava diameter has not been established. OBJECTIVES We set out to ascertain whether the optimal dimensions of the conduit could be determined before an ECFO. METHODS Actual and expected age-related inferior vena cava diameters were compared with the extracardiac conduit diameter in 20 patients after ECFO. In 50 other pediatric and adult patients, the distance between intrapericardial part of the inferior vena cava and the undersurface of the right pulmonary artery (IVC-RPA) was measured. Cases of conduit thrombosis were analyzed. RESULTS The actual diameter of the inferior vena cava was variable and has a weak correlation with anthropometric data and expected diameter (R=0.07-0.23, P=0.32-0.76). The IVC-RPA distance correlated with height (R=0.87, P=0.0001), but was also variable. At the age of 2-4 years and body weight 12-15 kg IVC diameter and IVC-RPA distance are equal to 60-80% of adult values. Conduit thrombosis developed in two patients with unfavorable Fontan hemodynamics and oversized conduits. CONCLUSIONS Considering the inferior vena cava size, ECFO may be performed at the age of 2-3 years and at a body weight 12-15 kg, when a hemodynamically optimal almost adult sized conduit can be implanted. Optimization of the conduit is necessary on the basis of the actual inferior vena cava diameter and IVC-RPA distance. Anticoagulation postoperatively should be considered to prevent conduit thrombosis in patients with suboptimal Fontan circulation

Renal function after cardiopulmonary bypass surgery in cyanotic congenital heart disease.

UNLABELLED We studied perioperative renal damage in 22 patients with long-standing cyanotic congenital heart disease. BACKGROUND [corrected] Postoperative acute renal failure is a major complication of cardiac surgery associated with poor prognosis. Our study was designed to identify risk factors for renal failure in patients with cyanotic congenital heart disease. PATIENTS 22 cyanotic patients with a oxygen saturation of 82% (38-92%), age 14 years (5-42 years) and six controls with atrial septal defect, age 37 years (28-66 years) were investigated with repeated urinary analyses. RESULTS Before operation, six of 22 of the cyanotic patients had albuminuria. Postoperatively three patients developed acute renal failure including glomerular and tubular damage. Urinary albumin analysis >1000 mg g(-1) creatinine after 24 h and N-acteyl-beta-D-glucosaminidase analysis >100 U g(-1) creatinine after 48 h predicted dialysis requirement. In noncyanotic controls only one preoperative and none of the postoperative analyses were pathological. CONCLUSIONS Patients with cyanotic congenital heart disease are at risk for acute renal failure, which can be prognosed by urine analysis already 24 h after surgery. Cyanotic glomerulopathy should be known before surgery. To lower the risk, cardiopulmonary bypass time should be kept as short as possible and adequate hydration should be maintained in combination with extended diuretic therapy.

Treatment of atrial septal defects in symptomatic children aged less than 2 years of age using the Amplatzer septal occluder.

AIMS To assess results of closure of atrial septal defects within the oval fossa by devices delivered by catheterisation in symptomatic infants and children under 2 years of age. METHODS AND RESULTS The Amplatzer septal occluder was used. Results, and complications of transcatheter device treatment in patients aged below 2 years were compared to previous results from our institution. PATIENTS We attempted closure in 12 consecutive patients below the age of 2 years who presented with an atrial septal defect between May 1997 and 1999. Symptoms were failure to thrive in 6, frequent chest infections in 5, and the need for treatment of heart failure in the other. All were thought to have a defect suitable for interventional closure. The atrial defects were seen in isolation in 10 children, but 2 had associated pulmonary stenosis which had been treated by balloon dilation prior to placement of the Amplatzer occluder. RESULTS The Amplatzer septal occluder was implanted at a mean age of 1.4 +/- 0.4, with a range from 0.8 to 1.8 years. Ratios of pulmonary-to-systemic flow had been 2.1 +/- 0.5, with a range from 1.6 and 3.2, and the defect was measured at 12 +/- 4 mms. Fluoroscopy time was 12.8 +/- 10.2 minutes, with a range from 5 to 43 minutes, and the time of the overall procedure was 162 +/- 70 minutes, with a range from 85 to 360 minutes. It proved necessary to remove the device in 2 patients (16%) because of a residual shunt and movement after release. One of these developed transient neurological complications. Both subsequently underwent surgical treatment. CONCLUSION Symptomatic patients less than 2 years of age can undergo successful closure of an atrial septal defect using the Amplatzer device, but the rates of success are less, and procedure time longer, than in older children or adults.

Complement and Contact Activation During Cardiovascular Operations in Infants

BACKGROUND By comparing the results of cardiac operations with or without cardiopulmonary bypass (CPB) in infants in a prospective study, we sought to determine which part of the postoperative systemic inflammatory response was caused by CPB. METHODS Thirty-five patients were divided into two groups: 11 infants operated on without CPB and 24 infants operated on with CPB. Blood samples were drawn before, during, and after the operation. We assessed complement function and the concentrations or activities of C1q, C3, C4, C1 inhibitor, factor B, the activated split product C3a, and prekallikrein and factor XIIa of the contact system. RESULTS All of the patients exhibited a decrease of complement proteins. This was greater in infants who underwent CPB. A increase in C3a and factor XIIa and changes in prekallikrein activity occurred only in infants during CPB. CONCLUSIONS Complement activation occurs in all infants, but is significantly higher in the group with CPB. Contact activation only occurs in patients who undergo CPB. Thus, the inflammatory response is caused by the use of a CPB circuit and to a lesser degree by surgical procedures and anesthesia.

Results of left atrioventricular valve reconstruction after previous correction of atrioventricular septal defects.

OBJECTIVE The objective of this study was to determine causes of severe left atrioventricular (AV) incompetence and the factors leading to the success of valve repair later after correction of atrioventricular septal defects (AVSD). METHODS A total of 28 patients aged 5 months to 38 years (mean age 6.7 years) were operated for significant (grade II-III) left AV valve incompetence (LAVVI), two months to twenty-five years (median 1.5 years) after correction of complete (11 patients) or partial atrioventricular septal defects. Fourteen patients had initially undergone surgery during infancy. RESULTS At reoperation a completely open or partially sutured cleft was found in 16 patients combined with dysplastic valve tissue in four cases, with a fibrotic valve in three cases, with posterior leaflet prolapse in two cases, with a double orifice valve in three cases, and a parachute valve in two cases. Partial or complete reopening of a previously sutured cleft caused by suture dehiscence was found in 12 cases combined with a fibrotic valve in five cases, with a dysplastic valve in one case and with severe deformity of valve in one case. A combination of these anomalies was observed in seven patients in both groups. Left atrioventricular valve repair including cleft closure combined with annuloplasty and other surgical procedures resulted in the disappearance or significant diminishing of LAVI in 18 patients (64%). Severe SAVI persisted in six patients, five of them exhibiting a combination of several additional left AV valve anomalies (fibrotic or dysplastic valve, parachute valve). Five of these six patients underwent successful left AV valve replacement with a mechanical prosthesis 7 days to 2 years after reoperation. The presence of additional left AV valve anomalies was the single statistically significant factor for recurrent major LAVVI after reoperation (P = 0.0106). There were two postoperative deaths in patients with mild LAVVI after surgery, and no late deaths. CONCLUSION An open cleft is the major factor of late severe SAVVI after correction of AVSD. Although suturing the cleft in conjunction with performing annuloplasty improved valvular function in most of the cases, the presence of severe left AV valve anomalies increased the risk of recurrent LAVVI and the need for valve replacement, thus playing a major role in determining the outcome of valve reconstruction in patients after reoperation.

Comparison of porcine xenografts and homografts for pulmonary valve replacement in children

BACKGROUND Due to the limited availability of homografts, different alternatives are used for replacement of the pulmonary valve. This study investigates the value of porcine stentless pulmonary xenografts in pediatric cardiac patients. METHODS Twenty-three pediatric xenograft (size 10 to 21 mm) recipients were compared with 23 homograft (size 9 to 21 mm) recipients. RESULTS Hospital mortality was 2 of 23 patients in the xenograft group and 3 of 23 in the homograft group (NS). Six out of 20 xenografts and 1 of 19 homografts were stenotic after 1 year (p = 0.011). Xenograft stenoses were mainly located at the distal anastomosis, while the leaflets were preserved. Homografts showed valvular stenoses and wall calcification. The 1 year freedom from reoperation was 77% in the xenograft and 93% in homograft recipients (NS), and from transcatheter intervention 84% and 100% (p = 0.004), respectively. Transcatheter intervention in 7 xenograft patients and 1 homograft recipient improved stenosis gradients from 65 to 40 mm Hg (mean) in 6 out of 8 patients. Explanted xenografts showed a loss of elastic membranes and proliferating connective tissue scars coated with activated endothelium. CONCLUSIONS Xenografts demonstrated a higher incidence of supravalvular obstructions, which were possibly due to unfavorable hemodynamics at the distal anastomosis. Histological findings additionally indicated a pronounced immunological response. Interventional angioplasty lowered the rate of reoperation. Thus, the use of xenografts in children can be accepted as a second choice when a homograft is unavailable.

Acute hemodynamic effects of post cardiotomy peritoneal dialysis in neonates and infants.

Objective: Evaluation of the acute hemodynamic changes during peritoneal dialysis in patients with low cardiac output syndrome and acute renal failure after open heart surgery.¶Patients: Three newborns and three infants after corrective surgery of congenital heart disease with post cardiotomy dialysis. Five of these had an open thorax during dialysis.¶Methods: Cardiac output measurements using the thermodilution technique on two consecutive days at four different times during the peritoneal dialysis cycle.¶Results: We did not find a deterioration of the cardiac index or systemic vascular resistance measured over two cycles in each of the six patients. Pulmonary artery pressure rose slightly after instillation of the dialysate solution in all patients. Changes in central venous pressure and left atrial pressure were not clinically meaningful. In all patients fluid removal by peritoneal dialysis was effective. All five surviving patients recovered renal function.¶Conclusions: Peritoneal dialysis can be performed in newborns and infants following cardiac surgery without causing acute hemodynamic imbalances. An open chest may have a significant impact on hemodynamic stability during peritoneal dialysis by blunting any possible negative alterations of increased intraabdominal pressure.

Clopidogrel in Infants with Systemic-to-Pulmonary-Artery Shunts

BACKGROUND Infants with cyanotic congenital heart disease palliated with placement of a systemic-to-pulmonary-artery shunt are at risk for shunt thrombosis and death. We investigated whether the addition of clopidogrel to conventional therapy reduces mortality from any cause and morbidity related to the shunt. METHODS In a multicenter, double-blind, event-driven trial, we randomly assigned infants 92 days of age or younger with cyanotic congenital heart disease and a systemic-to-pulmonary-artery shunt to receive clopidogrel at a dose of 0.2 mg per kilogram of body weight per day (467 infants) or placebo (439 infants), in addition to conventional therapy (including aspirin in 87.9% of infants). The primary efficacy end point was a composite of death or heart transplantation, shunt thrombosis, or performance of a cardiac procedure due to an event considered to be thrombotic in nature before 120 days of age. RESULTS The rate of the composite primary end point did not differ significantly between the clopidogrel group (19.1%) and the placebo group (20.5%) (absolute risk difference, 1.4 percentage points; relative risk reduction with clopidogrel, 11.1%; 95% confidence interval, -19.2 to 33.6; P=0.43), nor did the rates of the three components of the composite primary end point. There was no significant benefit of clopidogrel treatment in any subgroup, including subgroups defined by shunt type. Clopidogrel recipients and placebo recipients had similar rates of overall bleeding (18.8% and 20.2%, respectively) and severe bleeding (4.1% and 3.4%, respectively). CONCLUSIONS Clopidogrel therapy in infants with cyanotic congenital heart disease palliated with a systemic-to-pulmonary-artery shunt, most of whom received concomitant aspirin therapy, did not reduce either mortality from any cause or shunt-related morbidity. (Funded by Sanofi-Aventis and Bristol-Myers Squibb; ClinicalTrials.gov number, NCT00396877.).