Pathological study of infective endocarditis on Hancock porcine bioprostheses.

A pathological study has been performed on 10 infected Hancock bioprostheses removed from nine patients who died of prosthetic endocarditis. The devices had been in place from 2 to 87 months (average 37.5), the interval between operation and onset of infection averaging 30 months. The offending organisms were Gram negative bacteria in three patients (Klebsiella pneumoniae, Enterobacter cloacae, and Serratia marcescens), Gram positive bacteria in two (Staphylococcus aureus and Streptococcus viridans), and fungi in four (Candida species in three and Aspergillus species in one). Gross examination of the explants revealed in most cases a vegetative endocarditis of one porcine valve leaflets. Septic embolization occurred in five cases owing to the high friability of the vegetations. Prosthetic valve incompetence was the commonest type to dysfunction observed because of tears, perforations, and even complete destruction of the cusps. Prosthetic valve stenosis following obstruction of the valve orifice by infected polypous masses was noted in two cases. Clumps of infective organisms were detected deep in the cusp tissue in most cases on histologic examination. Infection located on the paraprosthetic tissues, associated with ring abscess, valve detachment, and insufficiency, was observed only once. According to the results of investigation, endocarditis on porcine bioprostheses is associated with a better preserved native valvular ring as viewed at reoperation. Therefore surgical intervention appears appropriate in the presence of severe hemodynamic complications after adequate antibiotic treatment. However, infection of these particular prostheses still carries an extremely high mortality. In the present series, this poor outcome might be explained by the frequently associated septic and thromboembolic events.

Incidence of residual defects determining the clinical outcome after correction of tetralogy of Fallot: postoperative late follow-up.

The postoperative results in 150 patients who had repair of tetralogy of Fallot (mean follow-up, 10.2 +/- 2.6 years) were defined as good in 71.3%, fair in 20.7%, and unsatisfactory in 8.0% on the basis of clinical criteria. Ninety-six percent of the patients are socially active, 92.0% have a good exercise tolerance, and 79.3% participate in sports. Data from 78 postoperative hemodynamic studies show mild right ventricular dysfunction in almost all patients examined. Peak systolic right ventricular/left ventricular pressure ratio decreased in the postoperative period in 65.4% of patients, remained unchanged in 3.8%, and increased in 30.8%. Minimal residual anomalies can modify the prognosis substantially. Of our patients, 53.3% of those with a shunt (p less than 0.05), 37.5% of those with stenosis (not significant), and 53.8% of those with pulmonary incompetences (p = not significant) have fair or unsatisfactory results. The associated defects are particularly unfavorable. Rhythm and conduction disturbances have resulted in fair or unsatisfactory results in 65.1% of patients. Such a disturbance occurring soon after bypass must be considered an incremental risk factor: 52.9% of patients seen with rhythm and conduction disturbances show the same disturbances later (p less than 0.001).

Vascular rings and slings. Diagnosis and surgical treatment of 49 patients.

Forty-nine infants with symptomatic vascular rings and slings, ranging in age from 20 days to 12 months, required surgical intervention between 1973 and 1984. The following anomalies were present in our patients: double aortic arch with left descending aorta (14), double aortic arch with right descending aorta (6), anomalous innominate artery (13), right aortic arch with aberrant left subclavian artery (4), left aortic arch with aberrant right subclavian artery (10), aberrant left pulmonary artery (pulmonary sling) (2). All the babies had symptoms related to compression of the trachea and/or esophagus. Four patients required temporary tracheostomy in the early postoperative period; 1 patient, affected by a pulmonary sling, required tracheal resection and anastomosis, for severe tracheomalacia. There was one hospital death in a patient with severe tracheal compression from an anomalous innominate artery and brain damage as a result of metabolic problems. Forty-eight patients survived and follow-up ranged from 3 months to 11 years. For each type of vascular anomaly encountered, and based on personal experience, we have outlined a diagnostic scheme allowing an accurate morphological definition and a subsequent surgical procedure.

Clinical evaluation of oxidative stress and myocardial reperfusion injury in pediatric cardiac surgery.

BACKGROUND: To evaluate oxidative stress and myocardial damage after aortic crossclamping release (ACCR) during cardio pulmonary bypass (CPB) in children two parameters were investigated: total glutathione (GSH) and its oxidoreductive reactions (GSH/GSSG) as expression of oxidative stress, and plasmatic turnover of myocardial taurine (TAU) as expression of cell damage. METHODS: The study was divided in two periods: 1) first period: analysis of oxidative stress and myocardial damage in 18 children. 2) Second period: evaluation of myocardial cell protection by controlled anterograde low oxygen warm reperfusion (ALOWR) before declamping. Twenty-one children were divided in two groups: not receiving (Group 1, 9 patients) and receiving (Group 2, 12 patients) ALOWR. RESULTS: In the first period GSH values increased significantly after onset of mechanical ventilation (MV) in vein, after CPB start in artery and after ACCR in coronary sinus. Moreover TAU turnover in aortic and coronary sinus blood increased significantly after ACCR. In the second period, Group 2 showed a lower oxidative stress after ACCR, while no differences were observed in TAU turnover. CONCLUSIONS: 1) Assessment of TAU and GSH levels can be considered a good method to clinically evaluate myocardial injury during cardiac surgery. 2) MV and CPB can induce oxidative stress before aortic clamping and can decrease the physiologic scavengers. Therefore, to prevent that depletion, the strategy of these techniques must be adapted to the patient and to his cardiac disease. 3) Intramyocardial TAU turnover is not significantly modified by the reperfusion technique. 4) ALOWR can reduce myocardial oxidative stress and can improve heart recovery after the cardioplegic arrest.

[Occurrence of hospital infections in a department of pediatric heart surgery]. / Studio di incidenza delle infezioni ospedaliere in un reparto di cardiochirurgia pediatrica.

The incidence of nosocomial infections (NI) and the related risk factors in a Department of Pediatric Cardiovascular Surgery were studied, during a 6 months period. 155 successive admissions were considered. Nosocomial infections were 17 (11%), nosocomial colonizations 18 (11.6%). The most important risk factors for nosocomial infections were: age, cyanosis, duration of hospitalization, hospitalization in Intensive Care Unit and central venous catheter only as a risk factor for sepsis. The most important risk factors for nosocomial colonizations were: tracheal intubation and central venous catheter. In 4 cases the NI was related to nosocomial colonization (2 sepsis, 1 pneumonia, 1 wound infection). The most frequently isolated microorganisms were Pseudomonas aeruginosa and Staphylococcus spp. The Authors found that a longer than 5 days period of antibiotic prophylaxis did not reduce the incidence of nosocomial infections.

[Severe neonatal cardiac insufficiency due to arteriovenous fistula of the vein of Galen]. / Grave insufficienza cardiaca neonatale da fistola artero-venosa della vena di Galeno. Considerazioni emodinamiche a proposito di 3 casi clinici.

The cerebral arteriovenous fistula is a rare cause of neonatal cardiac failure. We have recently observed three cases of severe cardiac failure associated with an arterio-venous malformation of the vein of Galen. At echocardiography and angiography the right cardiac chambers were seen to be more enlarged than the left ones. This may have resulted to some extent from an insufficient right-to-left shunt during foetal life due to a relatively small foramen ovale confronting an increased systemic venous return. Two of the neonates were operated upon and one survived. Based on our experience and on a review of the literature we feel that the diagnostic clues are: 1) severe cardiac enlargement; 2) a vascular bruit on the head; 3) hyperpulsatile neck vessels, sometimes with small peripheral pulses.

[Surgical treatment of infectious endocarditis in the active phase. Experience in 40 cases]. / Trattamento chirurgico dell'endocardite infettiva in fase attiva. Esperienza su 40 casi.

Despite recent advances in antimicrobial therapy infective endocarditis (IE) still remains a major surgical problem. All patients undergoing surgical treatment for IE at our Institution since 1970 were reviewed; among these in 40 IE was considered to be active at time of operation. Thirty patients were males and 10 females, ranging in age from 11 to 66 years (average 41); indications for operation were heart failure in 31, mycotic emboli in 5, and sepsis in 4. Nine were in NYHA functional class 11, 18 in NYHA class III, and 13 in class IV. Aortic valve replacement (AVR) was performed in 24 cases, mitral valve replacement (MVR) in 5 and multiple valve replacement (PVR) in 11. Overall hospital mortality was 15% (4.2% in the AVR group, 40% in the MVR group, and 27% in the PVR group). Postoperative follow-up was available in all survivors. Four patients died in the late postoperative period for not infective causes. Almost long-term survivors show, from 7 months to 10 years (average 58 months) postoperatively, a significant improvement. No complications related to the initial infective process were recorded. According to the results of the present study the following conclusions can be drawn: 1) active IE does not represent a contraindication to open heart surgery and prosthetic valve replacement; 2) the surgical results depend not only on the degree of cardiac failure, but mainly on its duration; 3) early surgical intervention affects favourably the prognosis, especially in cases of isolated aortic valve involvement; 4) the surgical management of IE removes the focus of infection.

Activation of the intracellular glutathione system by oxydative stress during cardiopulmonary bypass and myocardial perfusion.

The glutathione (GSH) system is the main defence of tissues against free radicals and red blood cells (RBC) are the most efficient sites for GSH redox cycle activation. Total GSH was assayed during cardiopulmonary bypass (CPB) in RBC and serum from the coronary sinus, peripheral arteries and veins in 18 children corrected of their cardiac defect. Our conclusions are: (1) RBC-GSH redox cycle is activated during heart ischaemia and reperfusion; (2) the activation of intracellular GSH system is preponderant compared with the extracellular one; (3) variations in intraerythrocytic total GSH during heart ischaemia and perfusion are detectable in peripheral veins and arteries, which can be the convenient sites for monitoring changes in the GSH cycle; and (4) increased total GSH levels are present in RBC before aortic crossclamping: at the beginning of mechanical ventilation in veins and, when CPB is started, also in arteries.