Extracorporeal life support in pediatric patients with congenital heart diseases: outcome of a single centre.

AIM: In pediatric patients with congenital heart disease low cardiac output (LCO) is the principal complication after corrective heart surgery. In LCO refractory to all therapeutic options, mechanical circulatory support is the final method to keep these patients alive. In this present study the authors reviewed the outcome of pediatric patients who required mechanical circulatory support after corrective surgery with extracorporeal membrane oxygenation or ventricle assisted devices (VAD). METHODS: A retrospective single centre consecutive cohort study was carried out in children who required different mechanical circulatory support indicated by postcardiotomy low output syndrome between 1991 and 2004. A total of 20 patients received extracorporeal life support. The indications for surgery were: 12 transposition of great arteries, 1 Bland-White-Garland syndrome, 3 tetralogy of Fallot, 1 hypoplasia of aortic arch, 1 total anomalous pulmonary vein connection, and 2 ventricle septum defect. RESULTS: Mean age was 1.29 years. Mean duration of assist was 8.87 days. Seven patients out of 20 survived, six could be discharged after myocardial recovery from LCO and one could be discharged after successful heart transplantation. The overall mortality in patients with extracorporeal life support was 65%. The causes of death were multiorgan failure and bleeding in one case was a VAD related complication. CONCLUSION: The use of extracorporeal life support (ECLS) shows a high mortality rate. However, ECLS can still help to keep some of those patients alive. Mechanical support devices are the ultimate chance to save time, to increase survival and to bridge the time until heart transplantation.

Heart transplantation in children after mechanical circulatory support: comparison of heart transplantation with ventricular assist devices and elective heart transplantation.

Heart transplantation (HTx) is an ultimate treatment for children with end-stage heart failure or inoperable congenital heart disease. The supply of hearts is inadequate; therefore, different mechanical support systems must be used as bridge to HTx in pediatric patients with postoperative low output. The use of ventricular assist devices (VADs) as bridge to HTx in children is limited because of size differences. The purpose of this study was to evaluate the overall long-term outcome of pediatric circulatory support before pediatric HTx. From 1989 through 2004, 91 pediatric patients underwent isolated HTx. Seven of them required mechanical support before transplantation. We reviewed retrospectively the course of 91 children (mean age 14.7 years) who underwent HTx. Group A consisted of elective HTx patients who were treated as outpatients before HTx, whereas group B was the VAD-HTx bridging group (n=7; mean age 12.31 +/- 2.8 years). Mean duration of VAD support was 108 +/- 98 days (minimum 1 day, maximum 258 days). Overall survival rate after HTx was 80% at 1 year without significant differences between groups. Five of seven patients survived and could be discharged after successful HTx, for a survival rate of 77%. The mean follow-up period was 16.76 +/- 10.6 months. No differences in posttransplantation long-term survival and rejection episodes occurred between patients transplanted with or without VAD. VAD therapy can keep pediatric patients with end-stage heart failure alive until successful HTx, and bridge to HTx is a safe procedure in pediatric patients. After HTx, survival rates of these children are similar to those of patients awaiting elective HTx.

Mechanical circulatory support: reality and dreams experience of a single center.

Because of the increasing number of patients waiting for heart transplantation and the decreasing number of donor organs, mechanical circulatory support has become a generally accepted therapeutic option. Several high-tech devices developed in the last 15 years differ in terms of location, kind of support, and driving units. They are suitable for different patients and their therapeutics objectives. Based on 13 years of experience, we developed a specific protocol for selection and management of patients and devices. Six hundred two patients have received mechanical circulatory support (MCS) in our institution since 1987. The indication spectrum includes cardiogenic shock for various reasons: acute myocarditis, right heart failure, acute rejection and postcardiotomy heart failure, alternative to transplantation, and bridge to recovery. Eight different systems are in use at our center. The extracorporeal devices, the Biomedicus centrifugal pump (n = 169) and the Abiomed BVS 5000 (n = 92) are used for short-term support. The Thoratec VAD (n = 179), and Medos HIA-VAD (n = 10) located in paracorporeal position preferably used for midterm support. Novacor LVAS (n= 96), and HeartMate (n = 58) are partially implantable systems used for long-term ventricular assistance in patients who did not require biventricular support. The advantage of the implantable devices is the option of discharging patients under support if they fulfill special criteria before being discharged to home. Eighty-five LVAD patients were discharged home with support, Novacor (n = 52), HeartMate (n = 27), ThoratecTLC-II (n = 8), Lionheart (n = 3) fulfill our criteria for being discharged home while on support. Careful postoperative patient management does not exclude a variety of complications. Bleeding: occurred in 22-35% of patients, right heart failure in 15-26%, neurologic disorder in 7-28%, infection in 7-30%, and liver failure in 11-20%. Complications varied with different devices, and the patients' preoperative conditions. Eighty-five patients fulfilled the criteria of our out of hospital program (OOH) and were discharged from hospital for a mean period of 184 days. Readmission was necessary for complications caused by thromboembolism and infection. This report describes our patient device selection criteria as a bridge to transplant setting.

The heater-cooler unit--a conceivable source of infection.

Even drinking water is contaminated with pathogenic microorganisms. This does not necessarily pose a risk for healthy individuals, but it may result in serious consequences in people with impaired immune systems. This is particularly valid if drinking water is used for medical purposes. The heater-cooler unit (HCU) connected to heat exchangers or blankets by tubing, the connection is closed water circuit that contains microorganisms and algae. While connecting the tubing to the heat exchanger, spilling of water cannot be avoided. Microbiological examinations showed that germs and particles pollute the units. Exposure to the patient and the OR equipment has the potential to increase the risk of infection should the HCU water come in contact with the patient. As a result of the high incidence of particle and algae in the HCU, malfunction occurs. Sampling shows >1000/mL CFU (colony forming units) at 36 degrees C and 55/mL CFU at 20 degrees C on average. The specific findings include Pseudomonas and Legionella. Disinfecting HCU is very difficult. Often HCUs do not provide any technology to reduce bacterial or other contamination. The instructions for use of oxygenators often exclude the use of disinfectants. Maintenance instructions for the HCU advocate the use of disinfectants that carry the risk of oxygenator damage and of heat exchanger leakage. The effect of chemical disinfectants and heat exchanger membranes have not been examined, they may impair heat exchanger permeability and function. As an alternative to chemical and thermal disinfection, we used the alternative method of filtration. Using a membrane filter element, we noticed a decreasing number of CFUs from 55 to sterile conditions at 20 degrees C and from >1000 CFUs to 100 CFUs at 36 degrees C (Figure 1). In addition, we noticed a removal of other particles and algae. In conclusion, we have demonstrated a technique that is simple to implement and effectively reduces the microbiological load of the water in the heater-cooler unit.

Pulsatile and nonpulsatile extracorporeal circulation using Capiox E terumo oxygenator: a comparison study with Ultrox and Maxima membrane oxygenators.

An open randomised, prospective study was undertaken on 90 patients who underwent routine myocardial revascularization. The aim of the study was to demonstrate that the Capiox E polypropylene fiber membrane oxygenator with a conventional single pulsatile/nonpulsatile blood pump for cardiopulmonary bypass (CPB) was comparable in performance to that of the Maxima and the Ultrox membrane oxygenators using a double pump system. The patients were divided into six groups according to perfusion mode and oxygenator type. Laboratory parameters, fluid balance and oxygenation was examined at set times before during and after cardiopulmonary bypass. Net fluid input was lower in the Capiox E groups regardless of perfusion mode: 2932 +/- 562 ml (Capiox E), compared to 3646 +/- 531 ml (Ultrox) and 3593 +/- 582 ml (Maxima). Net fluid balance 1288 +/- 534 ml was lowest in the Capiox/NP group, compared to 1604 +/- 460 ml (Ultrox/NP) and 1881 +/- 594 ml (Maxima/NP), (p < 0.05). The higher net fluid balance in the Capiox E/PP group 1649 +/- 580 ml compared to 1592 +/- 583 ml (Ultrox E/PP) and 1494 +/- 542 ml (Maxima/PP) was attributed to a technicality whereby the recommended priming volume of the Capiox E oxygenator was exceeded for safety reasons. The values of plasma free Hb were slightly higher in the PP than NP groups: Maxima/PP 80 mg/dl, /NP 50 mg/dl; Ultrox/PP 62 mg/dl, /NP 48 mg/dl; Capiox E/PP 55 mg/dl, /NP 48 mg/dl. The FiO2 was higher in the Capiox E groups 0.77 (PP) and 0.88 (NP) compared to Maxima/PP (0.66), /NP (0.65) and Ultrox/PP (0.64), /NP (0.63). Reciprocally, the venous saturation was higher in the Ultrox and Maxima groups compared to Capiox E at end of CPB. The study demonstrated that the CapioxE oxygenator with a single blood pump system can compare to the Maxima and Ultrox oxygenators with a double blood pump for CPB with regard to blood handling, oxygenation and fluid balance in routine cardiac surgery.