Luca Barozzi

Fate of the Aortic Root Late After Ross Operation

Background—The Ross operation is an alternative to mechanical aortic valve replacement in the young. Early dilatation of the pulmonary autograft root exposed to the systemic circulation has been reported. To define the prevalence of, risk factors for, and consequences of late autograft dilatation, outcome in all consecutive patients operated since May 1994 was reviewed. Methods and Results—Ninety one patients, 77 males and 14 females, with at least 1 year of follow-up underwent cross-sectional clinical and echocardiographic examination. Age at operation was 27±10 years (range 6 to 49), and the indication was aortic regurgitation in 54 (59%) patients and bicuspid valve was present in 62 (68%). End-points of the study were freedom from autograft dilatation (root diameter >4 cm or 0.21 cm/m2), from (moderate) autograft regurgitation and from reoperation. Follow-up (4.0±1.9, range 1 to 8 years) autograft root diameters were anulus, 29±4 mm (18–39); sinus of Valsalva, 38±7 mm (24–53); sinotubular junction, 37±6 mm (23–54); and ascending aorta, 37±5 mm (27–54). Late autograft dilatation was identified in 31 (34%) patients and regurgitation in 13 (14%), 7 of whom had autograft dilatation. At 7 years, freedom from dilatation was 42±8%, freedom from regurgitation was 75±8%, and freedom from reoperation was 85±10%. Cox proportional hazard analysis identified younger age (P =0.05), preoperative sinus of Valsalva (P =0.02), root replacement technique (P =0.03), and absence of pericardial buttressing (P =0.04) as predictive of autograft dilatation, whereas female sex (P =0.002), follow-up sinus of Valsalva (P =0.003), and sinotubular junction diameter (P =0.02) as predictive of autograft regurgitation. Conclusions—Autograft dilatation is common late after the Ross procedure, particularly in younger patients, in those with preoperative aortic aneurysm, and those having root replacement without support of anulus and sinotubular junction. Bicuspid aortic valve is not a risk factor. Significant autograft valve dysfunction affects a minority of patients, but it is more prevalent in those with autograft dilatation.

Diagnosis of infection in paediatric veno-arterial cardiac extracorporeal membrane oxygenation: role of procalcitonin and C-reactive protein

OBJECTIVES Plasma concentration of procalcitonin (PCT) and its value in the diagnosis of infection in paediatric patients treated with extracorporeal membrane oxygenation (ECMO) are undefined. This study aimed to define the levels of PCT and C-reactive protein (CRP) in paediatric cardiac ECMO patients and to determine their role in predicting infection, severity of organ dysfunction and clinical outcome. METHODS PCT and CRP plasma concentrations were measured daily in 20 consecutive infants and young children treated with veno-arterial ECMO. Each patient was examined daily for signs of infection and multiple organ dysfunction syndrome (MODS). A total of 139 patient days were classified for infection and MODS. RESULTS The median PCT and CRP plasma concentrations were not increased during infection: 2.4 vs 8.8 ng/ml and 223.8 vs 240.6 mg/l, in patients with vs without infection, respectively. PCT, but not CRP, was significantly elevated during MODS (10.9 vs 1.85 ng/ml) (P = 0.001). The area under the receiver operating characteristic (ROC) curve was 0.984 for PCT (95% confidence interval [CI], 0.962-1.000) compared with 0.347 for CRP (95% CI, 0.211-0.484) (P = 0.001). Only PCT differed significantly in patients weaned from ECMO who survived (2.6 ng/ml) vs patients not weaned from ECMO (10.5 ng/ml) (P = 0.001). The area under the ROC curve was 0.871 (95% CI, 0.786-0.956) compared with 0.261 for CRP (95% CI, 0.145-0.377) (P = 0.001). CONCLUSIONS Neither PCT nor CRP are reliable markers of infection in paediatric cardiac ECMO patients. However, high levels of PCT are associated with MODS. PCT may be used as a prognostic indicator of clinical outcome in this high-risk population.

Long-term results after aortic valve replacement with the Biocor PSB stentless xenograft in the elderly

BACKGROUND This study seeks to define the long-term results after Biocor PSB stentless aortic valve replacement (AVR) in elderly patients, including the effects of No-React treatment. METHODS We reviewed the outcomes of 106 consecutive patients, aged 70+/-6 years, having Biocor PSB (93 standard, 13 No-React) AVR between October 1992 and October 1996. RESULTS There were three early deaths (3%) and 15 late deaths (15%), during a mean follow-up of 5.8+/-1.6 years. At 8 years, survival was 82%+/-4% and freedom from cardiac death was 94%+/-3%. Freedom from valve failure was 92%+/-4% at 8 years (No-React: 92%+/-8% at 4 years). Replacement of the xenograft was required in 5 patients. Freedom from reoperation was 91%+/-4% at 8 years (No-React: 92%+/-8% at 4 years). Four bleeding and two embolic events were recorded: overall valve-related event-free survival was 81%+/-7% at 8 years (No-React: 76%+/-12% at 4 years). Age of long-term survivors averaged 77+/-5 years and their New York Heart Association status was 1.3+/-0.6 (versus 2.9+/-0.6 preoperatively, p = 0.01). CONCLUSIONS Satisfactory freedom from cardiac events and from valve deterioration added to uniform improvement in functional status despite advanced age and high prevalence of comorbid conditions make AVR with the Biocor PSB xenograft a valid long-term therapy for the elderly. No-React treatment does not influence xenograft durability.

Rescue extracorporeal life support for acute verapamil and propranolol toxicity in a neonate.

Extracorporeal life support (ECLS) to manage acute antiarrhythmic drugs toxicity in neonates has never been reported. Here presented is a case of venoarterial extracorporeal membrane oxygenation support in a newborn with refractory low cardiac output as a result of acute Ca-channel and β-receptor antagonist toxicity for treatment of paroxysmal supraventricular tachycardia (SVT). Shortly after onset of ECLS, the baby recovered sinus rhythm and subsequent bouts of SVT were controlled by amiodarone infusion and repeated DC shocks. Weaning was possible on the 5th day after implant, once recovery of the left ventricular function and optimization of the antiarrhythmic medication were achieved. In neonates with severe but potentially reversible cardiac dysfunction caused by drug toxicity, ECLS can maintain cardiac output and vital organ perfusion while allowing time for drug redistribution, metabolism, and clearance.

Aortic root replacement with the Carboseal composite graft: 7-year experience with the first 100 implants.

BACKGROUND Aortic root replacement remains a challenging surgical procedure. A variety of techniques and prosthetic devices have thus far been used. In order to assess the performance of the Carboseal (Sultzer Carbomedics, Inc, Austin TX) composite graft, review of the experience with composite root replacement was undertaken. METHODS Between January 1979 and December 1998, 273 patients underwent composite aortic root replacement. One-hundred-six received the Carboseal composite prosthesis (group 1) and 84 other types of composite grafts (group 2). Demographic and operative variables were similar in the 2 patient groups, except for an older mean age in group 1 (58+/-12 versus 50+/-12 years, p = 0.001). RESULTS Operative mortality was lower in group 1 patients (3 of 106, 3% versus 10 of 84, 12%, p = 0.04). Follow-up of survivors was longer in group 2 due to more recent adoption of the Carboseal grafts (93+/-57 versus 36+/-23 months, p = 0.01). Late mortality was higher in group 2 (3 of 103, 3% versus 13 of 74, 18%, p = 0.04), with higher prevalence of prosthetic-related complications (2 of 103, 2% versus 12 of 74, 15%, p = 0.002). Reoperation was more prevalent in group 2 (1 of 103, 1% versus 5 of 74, 8%, p = 0.04), and limited to patients having root replacement using the inclusion technique. Functional status of survivors was comparable in the 2 groups (83 of 103, 80% versus 45 of 74, 61% of patients in New York Heart Association class I, p = 0.1). CONCLUSIONS Aortic root replacement using the Carboseal composite graft offers excellent long-term results, with negligible prevalence of prosthetic-related complications. Superior performance compared to other available composite grafts in the present series may be influenced by more recent adoption of the Carboseal conduit and concomitant uniform adoption of coronary button technique.

Improved Outcome of Cardiac Extracorporeal Membrane Oxygenation in Infants and Children Using Magnetic Levitation Centrifugal Pumps

Extracorporeal membrane oxygenation (ECMO) has traditionally been and, for the most part, still is being performed using roller pumps. Use of first-generation centrifugal pumps has yielded controversial outcomes, perhaps due to mechanical properties of the same and the ensuing risk of hemolysis and renal morbidity. Latest-generation centrifugal pumps, using magnetic levitation (ML), exhibit mechanical properties which may have overcome limitations of first-generation devices. This retrospective study aimed to assess the safety and efficacy of veno-arterial (V-A) ECMO for cardiac indications in neonates, infants, and children, using standard (SP) and latest-generation ML centrifugal pumps. Between 2002 and 2014, 33 consecutive neonates, infants, and young children were supported using V-A ECMO for cardiac indications. There were 21 males and 12 females, with median age of 29 days (4 days-5 years) and a median body weight of 3.2 kg (1.9-18 kg). Indication for V-A ECMO were acute circulatory collapse in ICU or ward after cardiac repair in 16 (49%) patients, failure to wean after repair of complex congenital heart disease in 9 (27%), fulminant myocarditis in 4 (12%), preoperative sepsis in 2 (6%), and refractory tachy-arrhythmias in 2 (6%). Central cannulation was used in 27 (81%) patients and peripheral in 6. Seven (21%) patients were supported with SP and 26 (79%) with ML centrifugal pumps. Median duration of support was 82 h (range 24-672 h), with 26 (79%) patients weaned from support. Three patients required a second ECMO run but died on support. Seventeen (51%) patients required peritoneal dialysis for acute renal failure. Overall survival to discharge was 39% (13/33 patients). All patients with fulminant myocarditis and with refractory arrhythmias were weaned, and five (83%) survived, whereas no patient supported for sepsis survived. Risk factors for hospital mortality included lower (<2.5 kg) body weight (P = 0.02) and rescue ECMO after cardiac repair (P = 0.03). During a median follow-up of 34 months (range 4-62 months), there were three (23%) late deaths and two late survivors with neurological sequelae. Weaning rate (5/7 vs. 21/26, P = NS) and prevalence of renal failure requiring dialysis (4/7 vs. 13/26, P = NS) were comparable between SP and ML ECMO groups. Patients supported with ML had a trend toward higher hospital survival (1/7 vs. 12/26, P = 0.07) and significantly higher late survival (0/7 vs. 10/26, P = 0.05). The present experience shows that V-A ECMO for cardiac indications using centrifugal pumps in infants and children yields outcomes absolutely comparable to international registry (ELSO) data using mostly roller pumps. Although changes in practice may have contributed to these results, use of ML centrifugal pumps appears to further improve end-organ recovery and hospital and late survival.

Continuous Metabolic Monitoring in Infant Cardiac Surgery: Toward an Individualized Cardiopulmonary Bypass Strategy

Cardiopulmonary bypass (CPB) in infants is associated with morbidity due to systemic inflammatory response syndrome (SIRS). Strategies to mitigate SIRS include management of perfusion temperature, hemodilution, circuit miniaturization, and biocompatibility. Traditionally, perfusion parameters have been based on body weight. However, intraoperative monitoring of systemic and cerebral metabolic parameters suggest that often, nominal CPB flows may be overestimated. The aim of the study was to assess the safety and efficacy of continuous metabolic monitoring to manage CPB in infants during open-heart repair. Between December 2013 and October 2014, 31 consecutive neonates, infants, and young children undergoing surgery using normothermic CPB were enrolled. There were 18 male and 13 female infants, aged 1.4 ± 1.7 years, with a mean body weight of 7.8 ± 3.8 kg and body surface area of 0.39 m(2) . The study was divided into two phases: (i) safety assessment; the first 20 patients were managed according to conventional CPB flows (150 mL/min/kg), except for a 20-min test during which CPB was adjusted to the minimum flow to maintain MVO2>70% and rSO2>45% (group A); (ii) efficacy assessment; the following 11 patients were exclusively managed adjusting flows to maintain MVO2>70% and rSO2>45% for the entire duration of CPB (group B). Hemodynamic, metabolic, and clinical variables were compared within and between patient groups. Demographic variables were comparable in the two groups. In group A, the 20-min test allowed reduction of CPB flows greater than 10%, with no impact on pH, blood gas exchange, and lactate. In group B, metabolic monitoring resulted in no significant variation of endpoint parameters, when compared with group A patients (standard CPB), except for a 10% reduction of nominal flows. There was no mortality and no neurologic morbidity in either group. Morbidity was comparable in the two groups, including: inotropic and/or mechanical circulatory support (8 vs. 1, group A vs. B, P = 0.07), reexploration for bleeding (1 vs. none, P = not significant [NS]), renal failure requiring dialysis (none vs. 1, P = NS), prolonged ventilation (9 vs. 4, P = NS), and sepsis (2 vs. 1, P = NS). The present study shows that normothermic CPB in neonates, infants, and young children can be safely managed exclusively by systemic and cerebral metabolic monitoring. This strategy allows reduction of at least 10% of predicted CPB flows under normothermia and may lay the ground for further tailoring of CPB parameters to individual patient needs.

Operative risk and outcome of surgery in adults with congenital valve disease.

To define risk and outcome of surgery in adults with congenital valve disease (CVD), experience between 2002 and 2005 with 371 CVD operations (288 males, aged 56 ± 9 years) was compared with 2102 for acquired valve disease (AVD) (69 ± 22 years, p = 0.02). Diagnosis included: bicuspid aortic valve (BAV), 337, s/p ToF repair, 11; atrio-ventricular valve dysfunction, 10; other, 13. Associated lesions were present in 259 patients (70% vs. 17%, p = 0.001): ascending aorta, 205; right ventricular outflow tract obstruction, 40; coronary artery, 34; mitral/tricuspid valve, 27; septal defect, 17; subaortic stenosis, 4; aortic arch, 4; other, 3. Fifty-two patients (14% vs. 2.5% AVD, p = 0.001) had undergone 75 prior operations (1.4/patient) and 14 (3.8% vs. 1.9% AVD, p = 0.04) required urgent/emergent surgery (endocarditis, dissection). Valve repair was done in 36 (10% vs. 3% AVD, p = 0.02) and replacement in 335: stentless solution (native, autograft, xenograft) was offered to 101 (29%) patients. In BAV, partial root replacement was associated in 63, complete in 77 and ascending aorta in 92. Three (0.8%) hospital deaths occurred (vs. 1.9% AVD, p = 0.2) due to endocarditis. Twenty-six patients (7.0% vs. 10.8% AVD, p = 0.003) experienced complications (cardiac, 7; neurologic, 6; respiratory, 5; renal, 3; sepsis/multiple organ failure (MOF), 2; hemorrhage, 8). Urgent/emergent surgery predicted hospital mortality (p = 0.001). During 5-year follow- up (average 2.6 ± 1.8 years), there was one late cardiac death and three reoperations (98% free). Despite higher prevalence of associated procedures, reoperation and emergent indication, operative risk in CVD is lower than in AVD, possibly because of younger age. Stentless valve surgery, allowing normal life-style (e.g., exercise, pregnancy), is increasingly preferred.

Comparison Between D901 Lilliput 1 and Kids D100 Neonatal Oxygenators: Toward Bypass Circuit Miniaturization

Progress in biomaterial technology and improvements in surgical and perfusion strategy ameliorated morbidity and mortality in pediatric cardiac surgery. In this study, we describe our clinical experience comparing performance of two neonatal oxygenators. From January 2002 to March 2011, 159 infants with less than 5 kg body weight underwent heart surgery. Ninety-four patients received a D901 Lilliput 1 oxygenator with standard bypass circuit (group A), while 65 received a D100 Kids with miniaturized bypass circuit (group B). Miniaturization consisted in shortened arterial, venous, cardioplegia, and pump-master lines. Priming composition consisted in Ringers acetate solution with addition of albumin and blood, with target hematocrit of 24% or greater. In group B cardiopulmonary bypass (CPB) was vacuum-assisted and started with an empty venous line. Modified ultrafiltration and Cell-Saver blood infusion was routinely applied in both groups. Average ± standard deviation (SD) age at repair was 37 ± 38 days in group A and 59 ± 60 days in group B (P = 0.005). Average ± SD weight, height, and body surface area were 3.5 ± 0.7 kg, 52 ± 4 cm, and 0.22 ± 0.03 m(2) , respectively, in group A, and 3.7 ± 1 kg, 53 ± 5 cm, and 0.23 ± 0.02 m(2) , respectively, in group B (P = not significant [NS]). Male sex was predominant (55 vs. 58%, P = NS). Priming volume was 524 ± 67 mL (group A) and 337 ± 53 mL (group B) (P = 0.001). There were no statistical differences in hemoglobin at the start, during, and at the end of CPB, but group A required higher blood volume added to the prime (111 ± 33 vs. 93 ± 31 mL, P = 0.001). In group B, two surgical procedures were completed in total hemodilution. In group B, CPB time and aortic cross-clamp time were shorter than in group A (106 ± 52 vs. 142 ± 78 min and 44 ± 31 vs. 64 ± 31 min, respectively, P = 0.001). There were 16 hospital deaths in group A and 4 in group B (P = 0.04). Durations of mechanical ventilation and intensive care unit stay were 5.3 ± 3.2 vs. 4.1 ± 3.2 days (P = 0.02) and 6.5 ± 4.9 vs. 5.1 ± 3 days (P = 0.03), respectively. There were significant differences in inotropic score (1083 ± 1175 vs. 682 ± 938, P = 0.04) and blood postoperative transfusion (153 ± 226 vs. 90 ± 61 mL, P = 0.04). Twenty-seven patients in group A and 10 in group B presented with major adverse postoperative complications (P = 0.04). Use of neonatal oxygenators with low priming volume, associated with a miniaturized bypass circuit, seems to be a favorable strategy to decrease postoperative morbidity after cardiac surgery in neonates and infants.

Current management of double-outlet left ventricle: towards biventricular repair in infancy.

Background Double-outlet left ventricle (DOLV) is an extremely rare type of ventriculoarterial connection, mostly reported anecdotally with wide variations in morphology, surgical strategy and clinical outcome. The aim of the present study was to define current morbidity and mortality of biventricular repair and discuss surgical management in infancy. Methods Inclusion criteria were English literature publication; balanced ventricular development and completion of biventricular repair. Institutional experience was also reported. Study end points were survival and freedom from cardiovascular events. Univariate analysis to identify risk factors for complications was performed. Results During a 45-year interval, 37 cases of DOLV were identified. Median age at repair was 48 months (range 0.3–336); seven patients were infants. Extracardiac repair was performed in 21 (57%) patients, right ventricular outflow patch in seven, pulmonary translocation in six, and intraventricular repair in three. There were three (8%) hospital deaths, due to right heart failure, and seven (21%) patients experienced 10 perioperative complications. Univariate analysis showed year of operation (P = 0.02) and outflow patch technique (P = 0.003) as risk factors for hospital morbidity and mortality. During a median follow-up of 26 months (range 1–192), there was one death and seven reoperations. Ten-year survival and freedom from adverse cardiovascular events were 87 ± 6 and 70 ± 10%, respectively. Conclusion Although seldom reported in the past, repair of DOLV in infancy does not increase surgical risk. Early and late morbidity are mostly due to right heart complications and more common after right ventricular outflow patch repair. Paucity of follow-up information may underestimate actual late adverse event rate.