Andrea Valori

Nosocomial infections in pediatric cardiac surgery, Italy.

OBJECTIVE To evaluate the incidence of nosocomial infection (NI) in pediatric patients who received cardiothoracic surgery and to identify possible associated risk factors. DESIGN Prospective observational study. SETTING The cardiac surgery and cardiac intensive care units at the Regina Margherita Childrens Hospital, Turin, Italy. PATIENTS All patients who underwent surgery from July 20, 1998, to July 19, 1999, were enrolled, except patients with operative catheterization only. METHODS Clinical data were collected daily from July 20, 1998, to July 19, 1999. NIs were diagnosed according to US Centers for Disease Control and Prevention criteria. RESULTS 104 patients were included in the present study, 80 (76.9%) of whom underwent extracorporeal circulation. The NI ratio was 48.1% (50/104); the percentage of patients with NI was 30.8% (32/104): 23.1% developed one infection, 7.7% two or more. The rate of NI was 2.17 per 100 days of hospitalization (50/2,304). The most common pathogen was Pseudomonas aeruginosa. Important risk factors were length of preoperative admission >5 days, total length of admission >10 days, open chest during postoperative phase, and cyanotic heart disease. There was a significant association between sepsis and central venous catheterization for 3 days or more. Rate of sepsis was 19 per 1,000 catheter days (16/852). CONCLUSION NIs represent a frequent complication for children who undergo heart surgery. Based on our data, we suggest decreasing the preoperative stay as much as possible. The higher NI incidence in patients with an open chest postoperatively suggests that an alternative antibiotic strategy should be considered for these patients.

Asymptomatic inflammatory myofibroblastic tumor of the heart: immunohistochemical profile, differential diagnosis, and review of the literature

BACKGROUND Inflammatory myofibroblastic tumor (IMT) is an uncommon lesion, mainly occurring in children and young adults and extremely rare in the heart. IMTs are composed of differentiated myofibroblastic cells accompanied by inflammatory cells. Cardiac IMTs are considered biologically benign, but they may have fatal consequences depending upon the peculiarity of site. Because of their rarity in the heart, most knowledge is based on extracardiac lesions that have uncertain behaviour. METHODS AND RESULTS We investigated the morphologic features and the immunohistochemical profile of an intracardiac IMT, arising in the right outflow tract of an asymptomatic 11-month-old boy, by using a large panel of antibodies, many of them previously reported in extracardiac IMTs only. Results were compared with data of literature. After complete surgical excision of the tumor, the patient is disease-free at 1 year of follow-up. CONCLUSIONS The present case showed morphologic and immunohistochemical features characteristic of IMT. Immunohistochemistry was helpful for characterization and differential diagnosis. The immunoreactivity pattern (including calponin expression) was similar to that of extracardiac IMTs except for anaplastic lymphoma kinase 1 immunoreactivity, lacking in this benign intracardiac IMT but usually associated to favourable prognosis in extracardiac IMTs.

Liver stiffness modifications shortly after total cavopulmonary connection

OBJECTIVES Hepatic damage in Fontan circulation setting is well known. Mainly represented by fibrosis, it is still poorly understood. Transient hepatic elastography (Fibro-Scan) is a useful tool to test liver stiffness and is commonly used in the evaluation of liver fibrosis. Unfortunately, the increase of inferior vena cava pressure consequent to total cavopulmonary connection can probably interfere with Fibro-Scan evaluation altering the result evaluation with the conventional scale. To verify this hypothesis and to quantify the impact of venous pressure on Fibro-Scan results, we checked perioperative liver stiffness changes in patients undergoing total cavopulmonary connection. METHODS A prospective observational study was carried out on 9 patients undergoing extracardiac total cavopulmonary connection. Mean age at operation was 4.3 ± 0.6 years, and mean weight 14 ± 2.4 kg. Hepatic stiffness was analysed with Fibro-Scan evaluation immediately before and 4 months after surgery. Results were matched with several perioperative data: pulmonary pressures, conduit size, fenestration, hepatic enzymes and coagulation setting. RESULTS Preoperative hepatic stiffness was 6.2 ± 1.5 kPa, with a significant increase to 11.2 ± 4 kPa at a mean follow-up of 4 months (P < 0.01). Mean alanine aminotransferase was 16.9 ± 8.3 mg/dl preoperatively and 16.3 ± 8.7 mg/dl at discharge. Both values showed a significant correlation with liver stiffness raise, their Pearson Correlation Indexes being 0.8 and 0.7, respectively (P < 0.01). Mean aspartate aminotransferase/alanine aminotransferase ratio at discharge was 1.7 ± 0.5 and showed a significant negative correlation with liver stiffness raise, its Pearson Correlation Index being -0.7 (P < 0.01). CONCLUSIONS Liver stiffness increases rapidly after total cavopulmonary connection and perioperative variations in some liver enzymes appear to correlate with this change. Since a true anatomical damage is known to develop gradually with Fontan circulation, early liver stiffness raise is likely due to parenchymal congestion only. Fibro-Scan can easily recognize and assess the entity of such a change. For these reasons, this diagnostic tool must be considered useful only to monitor liver stiffness changes and evolution with time, but a conventional evaluation of results, like in other acquired hepatic fibrosis, can be misleading.

Life-Threatening Tumors of the Heart in Fetal and Postnatal Age

OBJECTIVES To evaluate the role of histology in diagnosis and management of biologically benign heart tumors causing life-threatening symptoms and even death in children and fetuses. The clinical impact of a multidisciplinary approach including 2-D echocardiography, histology, genetics, and cardiac surgery has not yet been fully elucidated. STUDY DESIGN Forty-one consecutive antenatal (n = 17) or postnatal (n = 24) detected cardiac masses were evaluated by 2-D echocardiography (in alive patients) or at autopsy, and 12/41 cases with definite histologic diagnosis of primary and benign cardiac tumor were entered in this study. RESULTS Rhabdomyomas (n = 6), hemangiomas (n = 3), central fibrous body chondroma (n = 1), fibroma (n = 1), or left atrial myxoma (n = 1) were histologically diagnosed in 4 fetuses and in 8 children. Death occurred in 6 patients showing diffuse or infiltrative tumors, 2/6 experiencing intrauterine death or sudden and unexpected infant death. Seven patients underwent surgery, 4/7 are alive and well at >5 years follow-up, whereas 3 deaths followed partial tumor resection. Two fetuses with extensive tumor/s were aborted. Tuberous sclerosis complex gene mutations were seen in patients with rhabdomyomas. CONCLUSIONS Histology represents the best diagnostic approach in life-threatening pediatric cardiac tumors allowing definite diagnosis in cases other than rhabdomyoma and in sudden deaths, influencing clinical management and counselling. 2-D echocardiography remains the main tool for early clinical diagnosis and follow-up. A multidisciplinary approach is advisable because of rarity, difficult management, and possible associations with inheritable diseases.

Pulmonary Valve Replacement With Mechanical Prosthesis: Long-Term Results in 4 Patients

Pulmonary valve replacement is rarely performed and is usually done with biological prostheses or grafts. The use of mechanical prostheses is still a debated issue. We analyzed the outcome of 4 patients at 11 years after pulmonary valve replacement with a mechanical prosthesis. During follow-up, all patients remained asymptomatic, with no arrhythmias and good anticoagulation. An echocardiogram showed preserved ventricular contraction and normal function of the prostheses, with low pressure gradients. No infective endocarditis occurred. Mechanical prostheses appear to be a good choice for pulmonary valve replacement. Surgical and clinical results were satisfactory with no complications, acceptable pressure gradients, and good ventricular function after more than 10 years. Lifelong anticoagulation is mandatory, but this is usually well tolerated.

Partial hepatic vein diversion in pulmonary arteriovenous malformations in congenital heart disease

The late appearance of pulmonary arteriovenous malformations after operations for complex congenital cardiac conditions may be explained in many ways. The necessity of hepatic blood flow to the lungs is now generally accepted for carrying some labile substance that is secreted by the liver and that has not yet been identified. Rerouting of hepatic blood to the lungs in cardiac patients can be accomplished with different methods, most of which are predisposed to thrombosis because of the slow flow in the tunnel. My colleagues and I describe a case of partial diversion of hepatic blood into the pulmonary circulation and suggest a strategy to decrease the likelihood of conduit thrombosis and to treat pulmonary arteriovenous malformations.

Securing atrial lines with Silastic ligatures.

We present a safe and easy-to-apply method of securing monitoring atrial cannulae after pediatric cardiac operations. We used Silastic ligatures together with purse strings on the tip of the atrial appendages in more than 350 cases, in a 5-year period. We never reported malfunctioning during their use, and no bleeding or rupture complication was detected by echocardiographic control after withdrawal.

Ventricular assist device in a failing total cavopulmonary connection: a new step-by-step approach

The management of failing Fontan patients with mechanical circulatory support has been reported with unsatisfactory results. A 5-year-old girl, listed for heart transplantation for failing Fontan, underwent rescue extracorporeal membrane oxygenation support. As it was necessary to move the patient to the Berlin Heart Excor, a step-by-step approach was designed to obtain a gradual adaptation to this form of support. A central extracorporeal membrane oxygenation, with a Berlin Heart apical and aortic cannulae, was implanted leaving the previously positioned femoral vein cannula in parallel with the outflow apical one. The femoral vein cannula was removed when the lungs recovered from the effects of surgical trauma. Four days later, the Fontan fenestration was closed, and after 4 more days, a gradual reduction of gas support was planned without problems. Oxygenator was then removed, and 4 days later, a 30-ml Berlin Heart EXCOR ventricle replaced the centrifugal pump. This sequential approach, which has never been described before, can improve the results of the ventricular assist device support in failing Fontan patients, because it allows a gradual adaptation, even in patients with damaged lungs.