Sven Dittrich

Masked left ventricular restriction in elderly patients with atrial septal defects: A contraindication for closure?

The impact of an atrial septal defect in the elderly with reduced diastolic elasticity of the left ventricle is unclear. We studied the hemodynamic changes during balloon occlusion of atrial septal defects in patients over 60 years of age. In 18 patients (61–78 years old; median, 70), the left atrial pressure and the mitral valve inflow was measured during complete balloon occlusion of the defect and after deflation of the balloon. In seven patients, the left atrial pressure and the E/A ratio of the mitral valve inflow increased markedly (P = 0.02). Mean atrial pressures reached values of 27 mm Hg and the v‐wave peak values of 55 mm Hg. Two patients received a transcatheter device closure and developed congestive heart failure. In the elderly, an atrial septal defect can have a decompressive impact on the left ventricle. Therefore, caution appears to be warranted if atrial septal closure is planned. Cathet Cardiovasc Intervent 2001;52:177–180.

Primary cardiac tumours: when is surgery necessary?

OBJECTIVE Primary cardiac tumours are rare. The literature predominantly contains series on myxomas in adults and only a few long-term series that involve the very different primary cardiac tumours in early childhood. As foetal ultrasonography has continued to improve, cardiac tumours are increasingly detected early before significant symptoms develop. It is a challenge for paediatric cardiologists and surgeons to ascertain which patients need surgery and which will benefit from conservative follow-up. METHODS A retrospective review of a 10-year period revealed 51 tumours in 26 children (median age: 1 month). Analysis was by presentation, location, associated findings, interventions, histological findings, and clinical course. RESULTS The most common tumours were rhabdomyomas (29), fibromas (nine), teratomas (two), and haemangiomas (two). The tumour location was the right ventricle in 24 and the left ventricle in 22 patients. The symptoms varied between abnormal heart murmur (20), arrhythmia and conduction abnormalities (ten), obstruction of the outflow tract >30 mmHg (nine), severe cyanosis (three) and congestive heart failure (two). Fourteen children with haemodynamic compromises underwent surgery. There was one post-operative death and one heart transplantation after bridging with an assist device. There was no tumour recurrence even when resection was incomplete. Nine of 13 children with rhabdomyomas had spontaneous tumour regression without intervention. CONCLUSIONS Most of the cardiac tumours in children are benign. Spontaneous regression is possible not only in rhabdomyoma. Surgical intervention is only required for children who develop relevant clinical symptoms. Total resection of the tumour is not the only therapeutic aim; more important is the restoration of the best possible heart function.

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.

Early failure of xenogenous de-cellularised pulmonary valve conduits — a word of caution!

OBJECTIVE The longevity of valved right ventricle to pulmonary artery (RV-PA) conduits is limited due to calcification and degeneration of non-viable structures. Xenografts are commonly used because of the restricted availability of cryopreserved homografts. Tissue-engineered (de-cellularised) pulmonary valves (TEPVs) were thought to be a valuable alternative to cryopreserved pulmonary homografts due to postoperative seeding with viable autologous vascular endothelial cells. METHODS From July 2007 to December 2008, xenogenous TEPV (Matrix P plus) were implanted in 16 patients in the right ventricular outflow tract for different indications, related to congenital heart disease. Mean age at operation was 14+/-11 years, including three patients younger than 1 year. The median conduit size was 22 mm (range: 13-26 mm). RESULTS The early and late survival rates were 100%. At a median follow-up of 10 months (range: 2-17 months), six patients (38%) had to be re-operated upon due to obstructed grafts. Five of these patients were older than 13 years (range: 13-26 years); one patient was younger than 1 year. On echocardiography before re-operation, mean systolic gradient in the main PA was 66+/-18 mmHg. In explanted conduits, we found a predominantly peripheral conduit narrowing without leaflet calcification. Histological examination revealed stenosis formation, due to inflammatory infiltration and severely fibrogenic pseudo-intimal reaction. CONCLUSIONS On the basis of our short-term results, the Matrix P plus de-cellularised tissue-engineered pulmonary valve cannot be regarded as an ideal conduit for right ventricular outflow tract reconstruction, as the widespread use of these grafts may increase the possibility of frequent early conduit failures.

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.

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.

Early obstruction of decellularized xenogenic valves in pediatric patients: involvement of inflammatory and fibroproliferative processes

BACKGROUND Decellularization of pulmonary valve substitutes is believed to eliminate immunogenicity and improve conduit durability. This study focused on a detailed histopathological and immunohistochemical analysis of explanted Matrix P plus valves, following their early obstruction in pediatric patients. METHODS Occurrence of fibrosis, scar formation, neovascularization, and inflammatory infiltrates were determined in longitudinal sections of four valve specimens explanted after 12-15 months. Valves were immunohistochemically analyzed for presence of different subtypes of inflammatory cells. The expression of smooth muscle actin and connective tissue growth factor was determined. RESULTS We observed a foreign body-type reaction accompanied by severe fibrosis and massive neointima formation around decellularized porcine valve wall, whereas the equine pericardial patch remained separated from porcine layer and acellular. Re-cellularization of decellularized matrix was low, and neovascularization was observed only in the neointima and scar tissue. Inflammatory infiltrates, composed mainly of T cells, B cells, and plasma cells, as well as the presence of dendritic cells, macrophages, and mast cells were detected in the tissue surrounding the porcine matrix. In the fibrous tissue, overexpression of connective tissue growth factor was observed. The leaflets remained functional, with normal endothelialization and no degenerative changes. Control pre-implant samples of Matrix P plus valve revealed incomplete decellularization of porcine matrix, which may have contributed to increased immunogenicity of these conduits. CONCLUSIONS Early obstruction of decellularized Matrix P plus valve is associated with massive inflammatory reaction and exaggerated fibrotic scaring around porcine conduit wall. Detailed studies will be necessary to determine factors that contribute to remnant immunogenicity of decellularized grafts.

Multimodality 3D‐roadmap for cardiovascular interventions in congenital heart disease—A single‐center, retrospective analysis of 78 cases

Modern fluoroscopic angiography systems permit rendering of three‐dimensional volumetric data sets using rotational angiography (3D‐RA). Along with magnetic resonance imaging (MRI) or multi‐detector‐row computed tomography (MDCT) data sets, they can be fused with live fluoroscopy images for roadmapping during therapeutic procedures, but the value of multimodality fused data sets has not been clarified.

Influence of Cold Storage on Renal Ischemia Reperfusion Injury after Non-Heart-Beating Donor Explantation

Background: Due to the increasing need for kidney donors, transplantation from non-heart-beating donors (NHBD) is currently being practiced more extensively. As detailed studies on the reperfusion injury of these kidneys do not exist so far, a comparison of renal ischemia reperfusion injury scores immediately after organ explantation with injury scores after NHBD organ explantation with subsequent cold storage would be useful. Methods: Non-stored kidneys were compared to a group of kidneys stored for 6.9 ± 1.8 h. Functional analyses were made during 145 min of ex vivo perfusion. Quantitative histological analyses were performed in all kidneys after termination of perfusion. Results: During ex vivo reperfusion, renal vascular resistance was elevated, while creatinine clearance, filtration fraction, renal oxygen consumption, and sodium reabsorption were below normal after non-heart-beating explantation and further decreased after subsequent washing and cold storage. In the kidneys subjected to cold preservation, histologically tubular damage was enhanced, and the total count, as well that for the intraglomerular neutrophil granulocytes were also elevated. Conclusions: Explantation from NHBD causes renal ischemia reperfusion injury. Cold storage augmented deterioration of the kidney as histologically and functionally demonstrated. Thus, preservation times for non-heart-beating kidneys should be carefully reappraised.

Cystatin C and neutrophil gelatinase-associated lipocalin: biomarkers for acute kidney injury after congenital heart surgery.

QUESTIONS UNDER STUDY To evaluate the diagnostic value of serum Cystatin C and urine neutrophil gelatinase-associated lipocalin (NGAL) for the detection of acute kidney injury in patients undergoing congenital heart surgery. METHODS Serial samples of serum Cystatin C and urine NGAL were collected from 139 consecutive patients with congenital heart defects aged 3 days to 30 years after admission to the intensive care unit, 2 and 6 hours after the end of cardiopulmonary bypass. Biomarker levels were compared to perioperative data retrospectively. Acute kidney injury was defined according to the paediatric-modified RIFLE classification. RESULTS According to the paediatric-modified RIFLE criteria 53% of patients developed evidence of acute kidney injury. Serum Cystatin C concentrations were strongly correlated with severity of acute kidney injury. Optimal sensitivity of 80% and specificity of 66% for the prediction of acute kidney injury occurred at a cut-off value of 0.995 mg/l, 2 hours after the end of cardiopulmonary bypass. The 2 hour urine NGAL concentration was significantly correlated to the duration of cardiopulmonary bypass, time of aortic cross clamping, and serum lactate concentration. Moreover a significant correlation was found between urine NGAL and both length of hospital stay and mechanical ventilation. CONCLUSIONS In patients after congenital heart surgery, urine NGAL indicates the damaging force of cardiopulmonary bypass and serum Cystatin C is a valuable predictive biomarker for resulting acute kidney injury.