Nosocomial infections after cardiac surgery in infants and children: incidence and risk factors.

This prospective study was undertaken to determine the spectrum, sites and main risk factors for hospital-acquired infections (HAI) in our paediatric cardiothoracic intensive care unit (PCICU), and to determine the main organisms causing bloodstream infection in this setting. All patients admitted between January and December 1999 were prospectively followed for the development of HAI. To define risk factors, patients were grouped by age, complexity score, length of stay in PCICU, and whether the patient's chest was open or closed postoperatively. Three hundred and thirty-five patients underwent cardiac surgery. Fifty-five patients acquired 69 HAIs (HAI patient rate 16.4%). The most common HAI were bloodstream and surgical wound infection in 10 and 8%, respectively. The main causative organisms were Klebsiella spp.,Enterobacter spp. and Pseudomonas spp. in 22, 17 and 16% of episodes, respectively. Staphylococcus spp. accounted for 16% of episodes. The main risk factors for developing HAI were: neonatal age [P < 0.05, odds ratio (OR): 5.89, 95% confidence interval (CI): 2.96-11.58] prolonged PCICU stay (P < 0.05, OR: 6.82, 95% CI: 3.37-14.48), open chest postoperatively (P < 0.05, OR: 3.44, 95% CI: 1.31-8.52) and high complexity score (P < 0.05, OR: 4.03 95% CI: 1.87-8.43). The main causative organisms of bloodstream infections in children hospitalized in the PCICU differ from those in adult and pediatric general intensive care units (ICUs) and include mainly Gram-negative bacilli. High complexity score, neonatal age, prolonged ICU stay, and open chest postoperatively are risk factors of HAI in this patient population.

Plasma vascular endothelial growth factor level is a predictor of the severity of postoperative capillary leak syndrome in neonates undergoing cardiopulmonary bypass.

Capillary leak syndrome (CLS), characterized by extravascular fluid accumulation and significant organ dysfunction, is a serious complication in children undergoing cardiopulmonary bypass (CPB). We examined the relationship between plasma vascular endothelial growth factor (VEGF) levels and severity of CLS. The kinetics of VEGF in the plasma of 11 neonates and 7 older children undergoing CPB were investigated, correlating plasma VEGF levels and CLS clinical presentation. The degree of postoperative CLS was quantified by measuring parameters of extracellular volume and end-organ dysfunction. A chest-wall soft-tissue-width index (CSTWI) was designed in order to standardize the extracellular fluid accumulation. Most CLS parameters were significantly more prominent in the neonatal patients. Low plasma VEFG levels (>35 pg/ml) were found in 3 neonatal control patients and all but, sample from the older group patient. The neonates had significantly higher preoperative VEGF plasma levels (684.4 +/- 559.1 pg/ml, P = 0.02), which decreased during the operation to levels below 35 pg/ml and increased again 24 h postoperatively to levels significantly higher than in the older patients (484 +/- 270.3 pg/ml, P = 0.001). Multilinear regression analysis found preoperative VEGF levels to independently correlate with CLS as represented by CSTWI (P < 0.01, r = 0.726). Both the occurrence of post-CPB CLS and plasma VEGF levels pre- and postoperatively were thus higher in neonates than in children. Plasma VEGF level is a predictor of the severity of postoperative CLS.

The Konno aortoventriculoplasty for repeat aortic valve replacement.

OBJECTIVE: To evaluate the outcome of aortic root augmentation by the Konno-aortoventriculoplasty technique as part of reoperative aortic valve replacement. METHODS: Since 1983, 15 patients, 12 males and three females, had repeat aortic valve replacement (AVR) with concomitant Konno aortoventriculoplasty. Age ranged from 1.2 to 18 years (mean 12.5 years). The underlying anatomic diagnoses were valve and subvalvar aortic stenosis in 11, truncal valve insufficiency in one, endocarditis in one, Shone's complex in one and severe aortic insufficiency associated with a ventricular septal defect in one patient. All patients had had previous AVR. The causes for reoperation were prosthetic valve stenosis due to growth in ten and paravalvular leak in one, homograft failure in two, xenograft failure in one, and left ventricular outflow tract obstruction (LVOTO) after mitral valve replacement in one patient. The mean size of explanted prostheses was 19.2 mm (13-23 mm) while the mean size of the implanted prostheses was 24.3 mm (19-27 mm) (P<0.01). Previous aortic root enlargement had been performed in 11 patients in conjunction with AVR. The Manougian technique was used previously in two, Konno aortoventriculoplasty in eight, and both techniques in one patient. The newly implanted aortic valves were a homograft in one patient and mechanical prostheses in 14 patients. RESULTS: There was one operative death (1 of 15 or 6.6%) in a 17.5 year old patient with previous AVR and posterior root enlargement, due to low cardiac output state. Follow-up ranged from 6 months to 17 years (mean 7.2 years). The only late death occurred in an 11.6-year-old patient due to prosthetic valve endocarditis. Two patients had complete heart block and had permanent pacemaker insertion (2 of 15 or 13.3%). One patient had pulmonary valve replacement because of combined stenosis and insufficiency 5 years after operation. All 13-surviving patients are asymptomatic at latest follow up. CONCLUSION: Konno aortoventriculoplasty with repeat AVR may be safely performed. Excellent results may be achieved despite previous aortic root enlargement. It is a good surgical option for complex LVOTO and may even reduce reoperation in children by allowing placement of a larger prosthesis.

Successful biventricular repair after initial Norwood operation for interrupted aortic arch with severe left ventricular outflow tract obstruction.

BACKGROUND: Management of newborns with interrupted aortic arch (IAA) remains challenging. Associated severe left ventricular outflow tract obstruction (LVOTO) have often led to increased mortality with neonatal biventricular repair. We review our experience with an alternative approach for this complex surgical problem. METHODS: From May 1991 to June 1999, 28 neonates were treated for IAA. Thirteen of 28 neonates (46%) had type B IAA, ventricular septal defect (VSD) and severe LVOTO (Z value -2 to -7; mean -5 +/- 1.7). Mean age was 8 days (3 to 23 days old) with average weight of 3.3 kg (2.4 to 4.2 kg). Eight of 13 (62%) had anomalous right subclavian artery. Ten of 13 (77%) had thymic aplasia and chromosome 22 region qll deletion. All 13 patients were treated initially with a modified Norwood procedure. RESULTS: There were no perioperative deaths. Complications included 2 patients with recurrent arch stenosis treated with balloon dilatation. Two patients had systemic arterial shunt revision. Follow-up ranged from 2 to 99 months old (mean 39 months). There were 2 late deaths unrelated to any operation. Nine of 12 patients had a second stage palliation consisting of a bidirectional Glenn shunt. Six patients went on to have biventricular repairs (3 Ross-Konno, 2 Rastelli, 1 VSD closure with LVOT resection). One patient had a modified Fontan operation and 5 patients are awaiting potential biventricular repair. CONCLUSIONS: Children with IAA and severe LVOTO may be managed by initial Norwood palliation with an excellent outcome likely. This initial "univentricular" approach has enabled eventual successful biventricular repair despite severe LVOTO.

Structural modification and cryopreservation of porcine heart valves for xenotransplantation with reduced immunity.

BACKGROUND AND AIM OF THE STUDY: In order to provide valved xenografts with reduced immunity, yet durability comparable with that of homografts, a method for endothelial cell removal was developed. METHODS: Adult porcine valved pulmonary conduits were isolated, washed and incubated in trypsin-EDTA solution. The endothelial cells were flushed free with a stream of culture medium, and the xenografts cryopreserved. Grafts were thawed after three months, and evaluated structurally. RESULTS: Macroscopic inspection of the grafts revealed no cracks or other morphological damage. Light microscopy revealed mildly edematous changes, and the elastic layers appeared to be preserved. Incubation with trypsin-EDTA solution consistently removed the entire endothelial layer, without obvious damage to the underlying tissues. CONCLUSION: With care and appropriate timing, the xenograft endothelium can be selectively removed, leaving the underlying tissue intact. This process may allow further structural manipulations to improve the durability of these grafts.

Superior vena cava syndrome following neonatal cardiac surgery.

OBJECTIVE: To review the incidence, diagnosis, and management of superior vena cava syndrome (SVCS) after surgery for congenital heart disease. DESIGN: Retrospective clinical review. All patients were computer registered. Our database includes daily follow-up. SETTING: Pediatric cardiac surgery intensive care unit in a university hospital. PATIENTS: A total of 1853 consecutive pediatric cardiac operations performed in 285 neonates and 1568 older children from 1993 to 1999 are reviewed. MEASUREMENTS AND MAIN RESULTS: The diagnosis of SVCS was suspected clinically: Color changes and swelling of the upper part of the body, confirmed by echo-Doppler, showed no or minimal flow in the superior vena cava at the beginning and collateral flow later on. Nine patients developed SVCS (0.5%). All the study patients were neonates. The prevalence of SVCS in our neonatal patients was 3.15% (nine of 285), with no SVCS in older children. Accompanying complications included chylothorax (five), hydrocephalous (four)-three of whom required ventriculoperitoneal shunt during follow-up. Thrombolytic therapy was used in five patients, and thrombectomy was used in one patient. The ventilation period ranged from 4 to 46 days (mean 20.1 days), and the length of hospital stay ranged from 37 to 120 days (mean 61.3 days). No mortality was observed during follow-up. CONCLUSIONS: SVCS is an uncommon, severe complication following neonatal cardiac surgery. It may cause chylothorax, hydrocephalus, and severe respiratory complications leading to high morbidity. Early diagnosis and thrombolytic therapy may prevent the progression of this syndrome to its subsequent sequels.

Extra-anatomic aortic bypass via sternotomy for complex aortic arch stenosis in children.

OBJECTIVE: Recurrent aortic narrowing after repair of aortic coarctation or interrupted aortic arch, as well as diffuse, long-segment aortic hypoplasia, can be difficult to manage. Extra-anatomic ascending aorta-descending aorta bypass grafting through a sternotomy is an alternative approach for this problem. METHODS: Since 1985, 19 patients aged 2 months to 18 years (mean 10.7 years) underwent extra-anatomic bypass with 10- to 30-mm Dacron grafts. The initial diagnosis was coarctation with hypoplastic arch in 15, interrupted aortic arch in 3, and diffuse long-segment aortic hypoplasia in 1. Seventeen of the children had a total of 22 previous operations: transthoracic interposition or bypass graft (n = 7), end-to-end anastomosis (n = 7), subclavian arterioplasty (n = 6), and synthetic patch (n = 2). The mean time from initial repair was 8.0 years (range 0.6-18 years). Three children had previous sternotomies. Cardiopulmonary bypass was avoided in all but 6 patients (5 with simultaneous intracardiac repairs). RESULTS: No hospital or late deaths occurred. On follow-up from 4 months to 14.7 years (mean 7.9 years), no reoperations for recurrent stenosis were performed. Two patients have arm-to-leg pressure gradients: 20 mm Hg at rest in 1 patient and a 60-mm Hg systolic exercise gradient with no resting gradient in the other. One patient required exclusion of an aortic aneurysm at the old coarctation repair site 13 years after extra-anatomic bypass. Three children had subsequent successful cardiac operations. CONCLUSIONS: Extra-anatomic bypass is an effective and relatively easy approach for selected cases of complex or reoperative aortic arch obstruction. It should be considered as an alternative operative technique for complex aortic arch reconstruction.

Anomalous origin of the left coronary artery from the pulmonary artery: diagnosis and postoperative follow up.

BACKGROUND: Anomalous origin of the left coronary artery from the pulmonary artery is a rare congenital malformation that presents a diagnostic challenge to the pediatrician and pediatric cardiologist. Although surgical repair is always indicated, the optimal technique has yet to be determined. OBJECTIVES: To review our experience with the diagnosis of children with ALCAPA and to assess short to midterm surgical results. METHODS: Between 1992 and 1998, 13 infants and children (2 months to 15 years) were treated for ALCAPA at our medical center. Eight were diagnosed during the first year of life; all were symptomatic and had severe dysfunction of the left ventricle. The five patients diagnosed at an older age had normal myocardial function. Diagnosis was established by echocardiography alone in seven patients; six required catheterization (one infant and all older patients). Surgery was performed in 12 patients to establish dual coronary artery system: 7 underwent the Takeuchi procedure and 5 had re-implantation of the anomalous left coronary artery. RESULTS: One infant died shortly after diagnosis before surgical repair was attempted, and one died postoperatively. Four patients required additional surgery: three for late complications of the Takeuchi procedure and one valve replacement for mitral insufficiency. Recent evaluation revealed good global left ventricle function in all patients except for one, who is still within the recovery phase and shows gradual improvement. However, most patients who presented with severe myocardial dysfunction upon diagnosis still display abnormal features such as echo-dense papillary muscles or evidence of small akinetic segments. In this group, early repair was associated with faster myocardial recovery. CONCLUSIONS: The diagnosis of ALCAPA remains a clinical challenge to the pediatrician and cardiologist. Diagnosis can be established echocardiographically, and early diagnosis and treatment may lead to faster myocardial recovery. The preferred surgical method appears to be re-implantation of the ALCA. The chance for good recovery of global ventricular function is high even in the sickest patients, nonetheless abnormal myocardial features can be identified even years after surgery.

Increased levels of basic fibroblast growth factor are found in the cross-clamped heart during cardiopulmonary bypass.

BACKGROUND: High concentrations of fibroblast growth factors (FGFs) are found in the heart. Even higher levels are measured during ischemia. Exogenous administration of FGF to ischemic myocardium promotes synthesis of collateral coronary circulation and induces local myocardial hypertrophy. The kinetics and the contribution of the heart and lungs to circulating basic FGF (bFGF) levels during cardiac surgery were characterized. PATIENTS AND METHODS: Plasma bFGF levels were measured in seven adults undergoing coronary artery bypass operations and 11 neonates undergoing congenital cardiac anomaly repair during cardiopulmonary bypass. RESULTS: In both the adult and the neonatal groups, bFGF plasma levels increased significantly immediately after removal of the aortic cross-clamp (adult group 15.43+/-6.3 aorta cross-clamped versus 29+/-4.1 after release, P=0.011; neonatal group 17.09+/-9.43 aorta cross-clamped versus 43.55+/-14.25 after release, P=0.004) and declined thereafter. In the adult group, higher levels of bFGF were recorded in blood recovered from the coronary sinus than in the aortic root during aortic cross-clamping (63.14+/-14.42 versus 43.86+/-12.05, P=0.011), and in both, levels were significantly higher than the peripheral measurements. CONCLUSIONS: Plasma bFGF levels increase during cardiopulmonary bypass. The source of this elevation is the lungs and heart.

Pectoralis major muscle flap for deep sternal wound infection in neonates.

BACKGROUND: Deep sternotomy wound infections during the neonatal period, their management utilizing the pectoralis major muscle flap (PMF), and their follow-up are reported. METHODS: Seven hundred-twenty consecutive pediatric cardiac operations performed from 1995 to mid 1998 in 108 neonates and 612 infants are reviewed. Nine children (1.25%), 6 neonates and 3 infants, developed deep sternotomy wound infections and underwent PMF reconstruction. The 6 neonates are reviewed. Their follow-up includes growth and development reports, physical examination, and computerized tomographic scans of the chest. RESULTS: The incidence of sternal wound complications in our neonatal patients (5.5%, 6 of 108) was significantly higher than in the infantile group (0.5%, 3 of 612), (p = 0.0001, odds ratio = 11.94). Five neonates were treated with a unilateral, turnover PMF reconstruction. One patient was treated by a bilateral rotational PMF. All sternal wounds healed successfully, and all patients survived. In a follow-up period, ranging from 6 to 31 months (mean 16.5 months), the growth and development of all operated neonates was as expected for their age. There were no signs of chronic sternal infection in any of them. CONCLUSIONS: Early recognition of sternal wound complications should facilitate surgical treatment. Utilizing the PMF promotes rapid wound healing and preservation of life in these severely ill neonates, with minimal developmental problems.

Septic emboli caused by vascular catheters after surgery for congenital heart disease.

OBJECTIVE: To review the incidence, diagnosis, and management of septic emboli caused by vascular catheters after surgery for congenital heart disease. DESIGN: Retrospective clinical review. All patients were computer registered. Our database includes daily follow-up and every sign of infection registered. SETTING: Pediatric cardiac surgery intensive care unit in a university hospital. PATIENTS: A total of 720 consecutive pediatric cardiac operations performed in 108 neonates and 612 older children from 1995 to 1997 are reviewed. MEASUREMENTS AND MAIN RESULTS: Septic emboli were defined as erythematous non-tender papulonodular hemorrhagic lesions restricted to the limb and distal to the monitoring catheter. Four patients (0.55%) with catheter-related septic emboli after congenital heart surgery were identified, three neonates (0.41%) and one older infant (0.14%). The incidence of catheter-related septic emboli in our patients was significantly higher in the neonatal group compared with older infants (p = .0076; odds ratio=17.45). All infants with catheter-associated septic emboli were severely ill and required prolonged intensive care management postoperatively for periods ranging from 27 to 90 days (mean, 50 days). The catheters involved were in place for periods ranging from 5 to 7 days. All patients were treated by catheter removal and intravenous antibiotics without surgical intervention in the vascular access area. The affected limbs healed well without residual damage. CONCLUSIONS: Septic emboli are a rare complication of infected vascular catheters in neonates and small infants undergoing prolonged postoperative intensive care management (0.55%). They may indicate the source of unexplained sepsis involving mainly Gram-negative bacilli. Generally, treatment consists of removal of the offending catheter and antibiotic administration with no need for surgical intervention.

Outcome and risk factors in octogenarians undergoing open-heart surgery.

BACKGROUND AND AIM OF THE STUDY: Increasing numbers of elderly (aged > 80 years) patients are being referred for cardiac surgery, and results for coronary artery bypass grafting (CABG) are generally better than for combined CABG and valve replacement. METHODS: During the past 55 months, 77 octogenarians underwent cardiac intervention in our institution. Forty-five patients (mean age 82.5 years) underwent CABG alone; surgery was elective in 33% of patients and 2.7 +/- 1.0 grafts per patient were performed. Thirty-two patients (mean age 82.4 years) underwent combined CABG and valve surgery (28 aortic, four mitral); 2.1 +/- 0.8 grafts per patient were performed and 65% of cases were emergencies. RESULTS: In patients undergoing CABG alone, the operative mortality rate was 2% and rose to 4% (n = 2) at the end of follow up. Mean NYHA functional class improved significantly from 3.5 +/- 0.5 to 1.4 +/- 0.3 after surgery (p < 0.05) and most patients reported marked improvement in their quality of life. In CABG + valve surgery patients, the operative mortality rate was 6% (n = 2) and reached 18% by the end of follow up. In these patients the complication rate was 24% and mean hospitalization stay 11.0 +/- 2.9 days, while mean NYHA functional class improved from 3.4 +/- 0.6 to 1.2 +/- 0.5. Data analysis revealed that mitral regurgitation combined with coronary artery disease (p < 0.03) and prolonged cross-clamping time (p < 0.01) were the most important independent factors for mortality. CONCLUSION: This study confirms that, in selected elderly patients, combined CABG and cardiac surgery can achieve good postoperative results.