Assessing a new coarctation repair simulator based on real patient's anatomy.

OBJECTIVES: To perform the preliminary tests of coarctation of aorta repair trainer, evaluate the surgical properties of the simulation and to assess and enhance residents' skills. METHODS: Single patient's angio-CT anatomy data were converted into magnified 3D-printed model of aortic coarctation with hypoplastic aortic arch, serving for creation of a mould used during wax copies casting. Wax cores were painted with six layers of elastic silicone and melted, yielding phantoms that were consecutively fixed in a mounting with and without a thoracic wall. Simulation included: proximal and distal aortic arch clamping, incision of its lesser curvature, extended end-to-end anastomosis with 7-0 suture. A head-mounted camera video recording enabled anastomosis time and mean one suture bite time evaluation. Leakage assessment was done by a water test. RESULTS: Two residents performed nine simulations each. Last four runs were performed with thoracic wall attached. All phantoms performed well, enabling tissue-like handling and cutting, excellent suture retention, and satisfactory elasticity. Median anastomosis times were 22'33″ and 24'47″ for phantoms without and with thoracic wall (p = not significant (NS)). Median times needed to pass suture through one side of anastomosis and regrasp needle were, respectively, 9″ and 13″ (p < 0.001). Median total number of leakages per phantom equalled 2 for both difficulty levels. There were no significant inter-resident differences in all assessed parameters. CONCLUSIONS: This medium-fidelity aortic coarctation repair trainer showed its feasibility in replication of major critical steps of the real operation. Objective surgical efficiency parameters could be obtained from each simulation and compared between trainees and at different adjustable difficulty levels.

Porcine carotid artery replacement with biodegradable electrospun poly-e-caprolactone vascular prosthesis.

OBJECTIVE: There is a continuous search for shelf-ready small-caliber vascular prostheses with satisfactory early and late results. Biodegradable scaffolds, repopulated by recipient's cells regenerating a neovessel, can be a suitable option for adult and pediatric, urgent and elective cardiovascular procedures. METHODS: This was a short-term experimental assessment of a new biodegradable vascular prosthesis for arterial replacement in the pig. Eleven pigs underwent bilateral carotid artery replacement with biodegradable electrospun poly-ε-caprolactone (PCL) nanofiber prostheses (internal diameter, 4 mm; length, 5 cm); or expanded polytetrafluoroethylene (ePTFE) prostheses as control. Perioperative anticoagulation was achieved with intravenous heparin (double baseline activated clotting time). Postoperatively, until conclusion of the study at 1 month, animals received aspirin and clopidogrel daily. Transit time flow was measured intraoperatively and at sacrifice. Doppler ultrasound (1 and 4 weeks) and a selective carotid angiography (4 weeks) were performed to assess patency. All explanted grafts were analyzed by histology, morphometry, and scanning electron microscopy in order to study graft-host interaction. RESULTS: Surgical handling and hemostasis of the new prostheses were excellent. Patency rate was 78% (7/9) for PCL grafts, compared with 67% (4/6) for ePTFE grafts. Transit time flow and Doppler ultrasound showed no significant changes in flow and velocity or diameter over time in both groups. Both prostheses showed no detectable in vivo compliance as compared with native carotid artery. Percent neoendothelialization was 86% for PCL and 58% for ePTFE grafts (P = .008). Neointima formation was equal in both grafts. More adventitial infiltration of macrophages, myofibroblasts, and capillaries was seen in PCL grafts with a milder foreign-body reaction when compared with ePTFE implants. Both grafts showed similar endoluminal thrombus formation. CONCLUSIONS: Biodegradable, electrospun PCL grafts showed good surgical and mechanical properties, no aneurysm formation, and similar short-term patency compared with ePTFE grafts. Rapid endothelialization and cell ingrowth confirms favorable PCL graft-recipient biological interaction. Despite good early results, long-term follow-up is required before clinical application.

Valve-sparing surgery for isolated cleft mitral valve complicated by endocarditis in a child.

A 12-year-old girl presented with an isolated cleft mitral valve complicated by infective endocarditis that was confined to the medial part of the cleft anterior leaflet. An innovative valve-sparing surgery was applied whereby the destroyed part of the leaflet was removed. The corresponding anterior annulus was plicated by approximation of the base of the cleft to the posteromedial commissure. The 'cleft' edge of AML was then sutured to the plicated annulus and to P3 at the level of the posteromedial commissure. The reconstructed valve was fully functional, and showed trivial regurgitation and an absence of stenosis for up to two years postoperatively.

A biodegradable ring enables growth of the native tricuspid annulus.

BACKGROUND AND AIM OF THE STUDY: The study aim was to assess the growth potential and function of the tricuspid valve (TV) annulus after annuloplasty with the intra-annular biodegradable ring. METHODS: Among 11 children (median age 4.5 years; age range: 0.2-10.9 years) who underwent surgery for severe congenital TV regurgitation, valve repair was completed using a biodegradable annuloplasty ring. The children were followed regularly using transthoracic echocardiography, whereby the TV annulus lateral diameter (TVALD) and valve function were monitored. Rates of valve growth were derived from the slope of the regression equations which related TVALD to the natural logarithm of the body surface area (lnBSA). RESULTS: The children's somatic growth was harmonious throughout the entire follow up period (mean 478 days; range: 171-1,477 days). The TVALD differed significantly at six months and at one and two years after surgery compared to the postoperative value at discharge, rising from 19 mm (range: 15.5-26.0 mm) to 24 mm (range: 19.0-30.0 mm) at the last control examination (p = 0.003), while the related Z-scores remained stable. A significant linear correlation between TVALD and lnBSA was found in 63.6% of patients. The median rate of growth for the whole cohort was 1.96-fold (range: 0.52-5.53-fold) higher than a norm, and correlated strongly and positively with age (r = 0.91; p <0.05). The median postoperative TV insufficiency fraction of 9.8% (range: 0-28.8%) remained constant during the follow up period. The postoperative TV maximal pressure gradient was 5.5 mmHg (range: 3.1-12.2 mmHg), and did not increase over time. CONCLUSION: The implantation of a biodegradable ring does not restrict growth of the native TV annulus; this enabled its stabilization in proportion to the somatic growth in the majority of the children. The TV annulus began to change its dimension at six months postoperatively, which may coincide with its biodegradation. The rate of growth of the TV annulus differed from that in the normal population, and was proportional to the patient age. The increase in TV annulus diameter over time did not have any negative influence on the function of the repaired valve.

Comprehensive assessment of a nationwide simulation-based course for artificial life support.

BACKGROUND: Successful implementation of medical technologies applied in life-threatening conditions, including extracorporeal membrane oxygenation (ECMO) requires appropriate preparation and training of medical personnel. The pandemic has accelerated the creation of new ECMO centers and has highlighted continuous training in adapting to new pandemic standards. To reach high standards of patients' care, we created the first of its kind, National Education Centre for Artificial Life Support (NEC-ALS) in 40 million inhabitants' country in the Central and Eastern Europe (CEE). The role of the Center is to test and promote the novel or commonly used procedures as well as to develop staff skills on management of patients needing ECMO. METHOD: In 2020, nine approved and endorsed by ELSO courses of "Artificial Life Support with ECMO" were organized. Physicians participated in the three-day high-fidelity simulation-based training that was adapted to abide by the social distancing norms of the COVID-19 pandemic. Knowledge as well as crucial cognitive, behavioral and technical aspects (on a 5-point Likert scale) of management on ECMO were assessed before and after course completion. Moreover, the results of training in mechanical chest compression were also evaluated. RESULTS: There were 115 participants (60% men) predominantly in the age of 30-40 years. Majority of them (63%) were anesthesiologists or intensivists with more than 5-year clinical experience, but 54% had no previous ECMO experience. There was significant improvement after the course in all cognitive, behavioral, and technical self-assessments. Among aspects of management with ECMO that all increased significantly following the course, the most pronounced was related to the technical one (from approximately 1.0 to more 4.0 points). Knowledge scores significantly increased post-course from 11.4 ± SD to 13 ± SD (out of 15 points). The quality of manual chest compression relatively poor before course improved significantly after training. CONCLUSIONS: Our course confirmed that simulation as an educational approach is invaluable not only in training and testing of novel or commonly used procedures, skills upgrading, but also in practicing very rare cases. The implementation of the education program during COVID-19 pandemic may be helpful in founding specialized Advanced Life Support centers and teams including mobile ones. The dedicated R&D Innovation Ecosystem established in the "ECMO for Greater Poland" program, with developed National Education Center can play a crucial role in the knowledge and know-how transfer but future research is needed.

Does patient-prosthesis mismatch influence the results of combined aortic valve replacement and coronary bypass grafting?

BACKGROUND: Combined aortic valve replacement and coronary revascularisation is becoming more frequent. Patient-prosthesis mismatch (PPM) as an additional risk factor may potentially affect the early and late outcome. AIM: To evaluate the impact of PPM on early and mid-term clinical results including quality of life in patients undergoing combined surgical treatment of coronary artery disease and aortic valve defects. METHODS: Medical records of 309 consecutive patients referred for combined surgery were reviewed. Patients were divided into three groups according to the presence of moderate or severe PPM (defined by aortic valve effective orifice area index in the range 0.85-0.65 cm2/m2 and smaller than 0.65 cm2/m2, respectively) or absence of PPM. The demographic and perioperative data, and early and late survival, as well as quality of life (SF-36) were analysed. RESULTS: The presence of severe PPM was found in 51 (16.5%) patients, whereas moderate PPM--in 153 (49.5%) patients. Patients from both PPM groups were significantly older than those without PPM. Subjects with severe PPM had higher weight and body mass index. They frequently had dyslipidaemia and both PPM groups received a biological valve more often than patients without PPM (94.1 and 77.1 vs. 19.1%, p<0.0001). There was no significant difference between all groups regarding early or late mortality. Advanced age, renal insufficiency and arrhythmia were predictors of early death. Late survival was determined only by number of postoperative complications in a Cox regression model. There was no difference in any components of the SF-36 survey between all groups. CONCLUSIONS: PPM is a frequent phenomenon in older patients requiring aortic valve replacement and revascularisation. Severe PPM occurs rarely, predominantly in obese patients. However, its presence does not affect early and late survival or quality of life.

[Is atrial septal defect always a simple defect?]. / Czy ubytek przegrody miedzyprzedsionkowej jest zawsze prosta wada?

A case of an asymptomatic 4-year-old girl with hemodynamically significant type II atrial septal defect is described. The patient underwent TEE in order to assess the eligibility for interventional device closure. Due to unfavorable anatomy and suspicion of the sinus venous type of the defect the child was selected for surgical treatment. No abnormalities were detected during surgery but a superfluous left atrial return of the venous blood during the cardiopulmonary bypass was noticed. The postoperative catheterisation was performed to elucidate this finding since the intraoperative TEE was normal. An anomalous venous drainage from superior and medial lobes of the right lung to the inferior vena cava was revealed. The 'scimitar' syndrome was diagnosed. Next, the patient underwent a successful surgical correction of this abnormality. The study presents the epidemiology, symptomatology and treatment modalities of the syndrome.

Type of cardioplegic solution as a factor influencing the clinical outcome of open-heart congenital procedures.

INTRODUCTION: Cardioplegia is one of the most important modalities of myocardial protection during heart surgery. AIM: To assess the impact of blood cardioplegia on postoperative variables, in comparison with two types of crystalloid cardioplegic solutions during pediatric heart surgery. MATERIAL AND METHODS: One thousand one hundred and twenty-nine patients underwent surgical correction of congenital heart disease with cardioplegia administration between 2006 and 2012. Nonlinear regression models of postoperative low cardiac output syndrome (LCOS) incidence, catecholamine index and total complication count were developed using a genetic algorithm. The Akaike information criterion was applied for selection of the best model. The following explanatory variables were evaluated: cardioplegia type (ST - Saint Thomas, n = 440; FR - Fresenius, n = 432; BL - Calafiore, n = 257), congenital heart diseases (CHD) type, age, sex, genetic disorder presence, body surface area (BSA), cardiopulmonary bypass (CBP) time, aortic cross-clamp time, operation urgency, redo surgery, surgeon. RESULTS: Low cardiac output syndrome presence and higher than average catecholamine indexes were negatively influenced by use of crystalloid cardioplegia (ST or FR), presence of specific CHDs, redo surgery and prolonged CBP time. Increased complication count was related to: crystalloid cardioplegia, presence of specific CHDs, redo surgery, urgency of operation, operation time and CBP time. Higher BSA had a protective effect against higher catecholamine index and increased complication count. Older age was protective against LCOS. CONCLUSIONS: Cardioplegic solutions type influences postoperative variables in children after heart surgery by the negative impact of crystalloid cardioplegia. Blood cardioplegia presents potential advantages for patients - its application may reduce the incidence of low cardiac output syndrome and related complications.

Comparison of cardiac function in children after surgical and Amplatzer occluder closure of secundum atrial septal defects.

OBJECTIVE: The aim of the retrospective study was to examine the changes in the left and right ventricular size as well as the systolic and diastolic function of the left ventricle after surgical and transcatheter treatment of atrial septal defects with Amplatzer atrial septal defect occluder (ASDO). METHODS: Two groups of patients were examined using transthoracic cross-sectional echocardiography before and after the treatment of atrial septal defect: Group A--Amplatzer ASD occluder--38 children and Group S treated surgically--20 children. The following parameters were assessed: left and right ventricular end-diastolic diameter indexes, ejection fraction, mitral E wave to A wave velocity ratio, deceleration time (DCT), isovolumetric relaxation time (IVRT) and heart rate. RESULTS: There was a significant decrease in right ventricular and an increase in left ventricular size in both groups during the follow-up observation. The long-term ECHO examination revealed smaller right ventricle (RV) (Group A: RVEDI=1.00+/-0.20 vs Group S RVEDI: 1.18+/-0.20 (p=0.001)) and bigger left ventricle (Group A: LVEDI=1.04+/-0.08 vs Group S: LVEDI=0.99+/-0.07 (p=0.022)) in Group A in comparison to Group S. Children undergoing operation had significantly shorter IVRT (Group A: IVRT=50.00+/- 9.65 vs Group S: IVRT=42.5+/- 8.95 (p=0.02)) than patients after ASDO device application. CONCLUSIONS: (1) During the follow-up period, the diastolic function of the left ventricle is better in children with device closure of ASD compared with those patients treated surgically. (2) Postoperative changes of the left and right ventricular size indexes are more favourable in patients after the device closure of ASD compared with children undergoing the surgical procedure.

Is device closure for direct access valved stent implantation safe?

OBJECTIVE: Despite the progress made in the development of valved stents for trans-apical valve replacement, a reliable closure of the access orifice remains a major issue. The present study was designed to evaluate if device closure of the ventricular wall is safe. MATERIALS AND METHODS: Transventricular access for pulmonary valve replacement was simulated with a 26F sheath and the resulting orifice was closed with an Amplatzer Muscular VSD Occluder (AMuscVSDO) in chronic sheep experiments (body weight 45-48 kg). Mean procedure time, blood loss, and standard hemo-dynamics were recorded. The animals were sacrificed electively and the histopathological changes in and around AMuscVSDO in the right ventricular wall were systematically studied by semi-quantitative analysis of collagenisation, inflammatory response and 'resorptive' process. RESULTS: Mean procedure time was 31+/-10.7 min, blood loss was 22.5+/-8.7 ml, heart rate was 123+/-22.6 bits/min before and 128+/-28.7 bits/min after, mean arterial blood pressure was 88+/-16.7 mm Hg before and 82.6+/-18.3 mm Hg after the procedure. Mean survival was 5.3 weeks. The collagen and scar formation studies revealed three different periods: (1) initial fibrosis (0-3 weeks); (2) so-called 'capsulation' (3-9 weeks after the implantation of the Occluder); and (3) final remodelling and differentiation (9 weeks). The fabric inside the Occluder played the role of a collagenisation promoter, active from the 3rd week till it vanishes. Inflammation plays a role as a temporary reaction (0-3 weeks) during the healing process, with no signs of any active, focal or circumscribed, myocardial damage. CONCLUSIONS: (1) The closure of the free ventricular wall perforation with AMuscVSDO is safe due to the scar tissue resulting from the healing process around and in the device. (2) The myocardial healing around and inside an implanted AMuscVSDO represents two processes: extensive fibrosis ensues around metallic wires with the progression towards the inside of the myocardium, whereas inside AMuscVSDO the loose connective tissue fills the myocardial lesion. During cicatrisation, the fabric elements of AMuscVSDO act as the ground for collagen formation and fibroblast proliferation. (3) The cicatrisation processes after ventricular AMuscVSDO implantation show remodelling, with rearrangement of collagen fibres architecture and distribution.

Application of the CardioCel bovine pericardial patch - a preliminary report.

INTRODUCTION: Animal pericardial patches are widely used in adult and pediatric cardiac surgery. A search is ongoing for a new material with optimal surgical properties that will reduce intraoperative bleeding and the occurrence of restenosis, calcification, and pseudoaneurysms in long-term observation. One product of interest is the CardioCel bovine pericardial patch. AIM: Evaluation of the short-term results of CardioCel bovine pericardial patch implantation during pediatric cardiac surgery. MATERIAL AND METHODS: The study included 8 patients who underwent surgical correction of congenital cardiac defects between January 2015 and February 2016. Pericardial patches were used to repair supravalvular aortic stenosis and reconstruct the aortic arch and pulmonary arteries. The age of the patients ranged from 10 days to 14 years. RESULTS: There were no hospital deaths. The new material exhibited satisfactory durability and elasticity during surgery, facilitating optimal adaptation of the patch to the patient's tissues. No significant bleeding was reported from the suture site. The median duration of follow-up was 58 days. During the follow-up, there were no symptoms of pseudoaneurysm formation, patch thickening, or calcification in the areas where the pericardial patches were implanted. No clinical or laboratory symptoms of infection were observed in locations where the new material was applied. CONCLUSIONS: Satisfactory surgical properties of the patch were observed intraoperatively. Positive results using the new pericardial patch were obtained in short-term follow-up.

Mid-term experience with valved bovine jugular vein conduits.

From June 1999 to January 2004, 43 children underwent implantation of a valved bovine jugular vein conduit and correction of complex congenital heart defects. Median age was 1.98 years (range, 11 days - 13.3 years). There were 7 early deaths (16.3%) unrelated to conduit failure or thrombosis. Median follow-up of 36 survivors was 24 months (range, 1-48 months, quartile range, 12-48 months), total follow-up was 78 patient-years. There were 3 late deaths (8.3%) due to infection, pulmonary thromboembolism, and sudden cardiac arrest after re-operation to repair a right ventricular outflow tract aneurysm. There were 2 conduit explantations due to dysfunction and suspected endocarditis. Three patients underwent balloon dilatation of distal stenoses. The mean peak gradient through the pulmonary anastomosis was 15 mm Hg (range, 3-42 mm Hg) among patients free from re-intervention. No severe valve regurgitation was observed. Freedom from re-intervention was 72% at 48 months. This conduit remains a good alternative to homografts. Causes of distal stenosis must be clarified, guidelines for prophylactic anticoagulation must be created, and the role of percutaneous balloon dilatation established.

Closure of perimembranous ventricular septal defect using transcatheter technique versus surgical repair.

INTRODUCTION: Since the Membr VSD occluders have been introduced into clinical practice it is now possible to compare two treatment methods -- surgical and percutaneous. AIM: Assessment of the effectiveness and risk of complications in patients with perimembranous ventricular septal defect (VSD) treated with the Membr VSD occluder or surgery as well as comparison of postprocedural left and right ventricular systolic functions. METHODS: The study involved 11 children with perimembranous VSD treated with occluder implantation (Group A) and 12 children with surgical repair (Group C). Groups A and C differed slightly in terms of age of patients (p=0.026), but had similar mean weights (p=0.103), pulmonary to systemic flow ratios (Qp: Qs, p=0.929) and follow-up duration after the procedure. No significant differences were observed between the two groups in terms of left ventricular systolic function [left ventricular ejection fraction (EF, p=0.567)], diastolic function [mitral flow E/A ratio (p=0.975)], E deceleration time (DCT, p=0.346), isovolumetric relaxation time (IVRT, p=0.606), heart rate (HR, p=0.133) or left ventricular diameter (LV) on transthoracic echocardiography (TTE) before VSD closure. TEE was performed in all patients and the parameters listed above were measured within 3 to 16 months after the procedure, and then intra- and inter-group comparisons were carried out. Additionally, mitral (MV), tricuspid (TV) and aortic (Ao) valve regurgitations were evaluated. RESULTS: Tricuspid (TR, p=0.028) and mitral regurgitation (MR, p=0.043) decreased significantly after closure of VSD with the Membr VSDO. MR was significantly smaller in patients treated with the occluder than in those after surgery (p=0.026). Postprocedural TR (p=0.486) and aortic regurgitation (AR, 0.607) did not differ significantly between the two groups. Left ventricular EF was significantly (p=0.004) lower and HR higher (0.043) after surgery than in children treated with the occluder. No significant differences of the diastolic function were found - E/A (p=0.88), DCT (p=0.413), IVRT (p=0.09). CONCLUSIONS: 1. During the mid-term follow-up left ventricular EF was higher in patients after Membr VSDO occluder implantation than after surgical repair of VSD. 2. Higher EF and reduction of the left ventricular diameter after closure of perimembranous VSD with the occluder may result in a lower incidence and degree of MR in comparison to the subjects operated on.

[Ross operation using "contegra" conduit in a 5 year old girl with severe aortic valve insufficiency in Kawasaki disease coexisting with infective endocarditis--a case report]. / Ciezka niedomykalnosc aortalna w chorobie Kawasaki wspólistniejaca z bakteryjnym zapaleniem wsierdzia u 5-letniego dziecka. Operacja Ross'a z zastosowaniem Conduitu "Contegra".

A case of a 5-year-old girl with severe dysfunction of aortic valve in Kawasaki disease coexisting with endocarditis, is described. The role of Ross operation in the treatment of this condition is discussed. The 18-months follow-up showed good function of aortic valve and "Contegra" conduit (bovine jugular vein), but long-term follow-up of patients with "Contegra" conduit remains unknown. In conclusion, a Ross operation using "Contegra" conduit in pulmonary position could be effective method in the treatment of dysfunction of aortic valve in Kawasaki disease coexisting with endocarditis in children.

[Percutaneous procedures for the repair of iatrogenic occlusion or stenosis of peripheral vessels in children--report of 5 cases]. / Przezskórne zabiegi naprawcze zwezonych jatrogennie naczyn obwodowych. Opis pieciu przypadków.

Invasive percutaneous diagnostic or therapeutic procedures are associated with the risk of thrombosis and occlusion of peripheral vessels which are used for vascular access. Data on the transcatheter therapy of vascular complications in children are scarce. We described five children in four of whom percutaneous transluminal balloon angioplasty of occluded peripheral vessels was successfully performed. Technical aspects of this treatment and indications are discussed.

Aortoventriculoplasty and left ventricle function: long-term follow-up.

OBJECTIVE: Depressed cardiac function after aortoventriculoplasty is well known during the postoperative period. Little data exist concerning the long-term follow-up. The aim of this study is to determine whether septal incision has any permanent effect on the left ventricle function. METHODS: From 1988 to 2002, 45 patients received aortic mechanical prosthesis. These patients were divided into two groups. Group A consisted of 26 patients 5-18 years old, who underwent simple aortic valve replacement. Group B consisted of 19 patients 4-20 years old, who underwent the Konno procedure. Systolic and diastolic functions of the left ventricle were analyzed using echocardiography. For the systolic function, the following parameters were assessed: pressure gradient between left ventricle and ascending aorta, shortening and ejection fraction of the left ventricle. For the diastolic function, left ventricle-filling parameters were assessed: ratio of early to late filling velocity, deceleration slope of the early filling velocity and left ventricular isovolumetric relaxation time. Furthermore the percentage fraction of the aortic valve index (AOVI%) was calculated and compared between these two groups. RESULTS: After the surgery in group A, AOVI% dropped from 110+/-21 to 98+/-11%, while in group B it increased from 82+/-16 to 114+/-11%. As a result a higher residual pressure gradient across the aortic valve was noted in group A: 21.26+/-15 as compared to 11.17+/-5 mmHg in group B. A mean pressure above 30 mmHg appeared in group A 2 years after the surgery, while in group B this was obtained after 6 years. As for the diastolic function no significant difference was noted between these two groups. Overall there was one late death in group A, and in group B two early deaths, two reoperations because of excessive drainage and in two patients permanent pacemakers had to be implanted. CONCLUSIONS: Improvement of the systolic function after the surgery was noted in both groups. In patients with low AOVI%, postsurgical pressure gradient, either residual or recurrent, appeared during the follow-up. As for the septal incision, it may have some transient effects on the left ventricle function in the postoperative period, but no permanent sequelae were observed in the long-term follow-up.

Arterial switch operation in neonates with complex congenital heart defects.

The aim of the study was to analyze short-term results of the arterial switch operation in 29 neonates with simple transposition of the great arteries (group A) and 18 (group B) with complex heart defects: transposition with a ventricular septal defect (10), coarctation of the aorta (5), or Taussig-Bing anomaly (3). The operations were usually performed on the 7th day of life (2nd-30th day), after a Rashkind procedure when necessary. The mean weight was 3,530 +/- 780 g, body surface area was 0.219 +/- 0.032 m(2). Delayed sternal closure was necessary in 7 patients from group A (24%) and 8 from group B (44%) because of hemodynamic instability after weaning from extracorporeal circulation; these neonates had significantly lower body weights and smaller body surface areas. Perioperative mortality was 13.8% (4 patients) in group A and 27.8% (5 patients) in group B. Correction of complex transposition tends to be associated with a higher operative risk than simple transposition, but the difference was not significant.

Infection risk factors in pediatric cardiac surgery.

Cardiac operations were preformed in 499 children from January 1998 through December 1999. Their median age was 263 days. A positive culture from blood, bronchoalveolar lavage, wound, or central catheter was obtained in 110 patients (22%). Age, sex, presence of pulmonary hypertension, body surface area, ratio of body surface area to oxygenator surface area, whether heart surgery was open or closed, and the duration of the operation, cardiopulmonary bypass, intubation, and intensive care were analyzed. Patients who developed infections were significantly younger, with smaller body surface areas and disparity with the oxygenator surface area, longer operative and bypass times, extended intubation, and prolonged intensive care. There was a significant correlation between infection and pulmonary hypertension. Sex and type of operation were not predictors of infection.

Biological effects of anti-CD34-coated ePTFE vascular grafts. Early in vivo experimental results.

AIM OF THE STUDY: To assess the biological activity of anti-CD34 antibody-coated ePTFE vascular prostheses. MATERIAL AND METHODS: Indium(111)-labeled autologous thrombocytes were administered to 5 anesthetized pigs after the placement of femoral arterial and venous catheters. An arterio-venous fistula, created by the random interposition of 4 different ePTFE grafts (A = dry control, B = dry anti-CD34, C = wet control, D = wet anti-CD34), was blood perfused for 0, 10, 30, 60 and 120 minutes. Radioactivity of each graft was measured and expressed in cpm/mg. Morphological studies were performed to assess intraluminal deposition. RESULTS: The median radioactivity of graft B was significantly higher than that of graft A after 60 min (1074 vs. 18; p = 0.021) and 120 min (1990 vs. 25; p = 0.043) of perfusion. Similarly, graft D was significantly more active than graft C (60 min: 1388 vs. 26; p = 0.021 and 120 min: 2780 vs. 23; p = 0.021). Histological and SEM results confirmed the radio-labeling in-vivo studies by showing significantly more protein/cell and platelet depositions (p = 0.012). CONCLUSIONS: Anti-CD34-coated ePTFE grafts bound significantly more platelets/cells and proteins than their uncoated counterparts, confirming the bioactivity of the antibody. This process is time-dependent and matches the morphological results. The anti-CD34 coating may enhance temporal and spatial endothelialization of vascular grafts and, thus, possibly improve clinical results by providing direct endothelial progenitor cell (EPC) adhesion/entrapment or by creating a biocompatible protein-thrombocyte/cell layer that indirectly enhances migration and further proliferation of EPCs.

A novel high vacuum chest drainage system - a pilot study.

AIM: To assess the safety and feasibility of use of a novel high vacuum chest drainage system (HVCDS) and its influence on the cardiovascular system compared to a conventional system (CCDS). MATERIAL AND METHODS: Five anesthetized pigs underwent a median sternotomy. Three drains were placed in retrocardiac, retrosternal and left pleural positions. The animals received a HVCDS (22 Fr with 180 2-mm holes, n = 2) or a CCDS (n = 2). In the fifth animal off pump coronary artery bypass graft (OPCABG) stabilizers were tested. After chest closure animals had three 30 min runs of artificial bleeding (5 ml/min) under different negative aspiration pressures (-2, -20, -40 kPa) for both groups, followed by standardized surgical bleeding (-40 kPa - HVCDS, - 2 kPa - CCDS). Hemodynamic parameters and each drain's output were registered every 5 minutes and the residual blood was assessed. All catheters, the heart and left lung underwent macroscopic and histopathological examination. RESULTS: The application of the different pressures showed neither hemodynamic changes nor differences in blood drainage with both systems in two bleeding models. The HVCDS enabled drainage comparable to the CCDS but showed relevant clotting. Application of -20 kPa and -40 kPa caused macroscopic epicardial and pulmonary lesions in all tested devices including OPCABG stabilizers consisting of sub-epicardial or sub-pleural hemorrhage without myocyte or alveolar damage. CONCLUSIONS: The novel and conventional chest drainage systems used at pressures up to 40 kPa induced no hemodynamic instability. Both systems showed adequate equal drainage, despite major HVCDS clotting. High negative pressure drainage with both systems showed focal sub-epicardial and subpleural hemorrhage. Thus, long-term assessment of high pressure drainage and potential interaction with fragile structures (coronary bypass graft) should be carried out.