Evaluation of the Appropriate Root Pressure for Maintaining Heartbeat during an Aortic Cross-clamp for Primary Repair of the Aortic Arch in Premature Infants with Associated Cardiac Anomalies

We developed a new cardiopulmonary bypass (CPB) method to minimize myocardial damage during aortic arch reconstruction. In this method, coronary flow and heartbeat were stabilized by maintaining the aortic root pressure with an adjusted preload of the ventricle during aortic cross-clamping. This study was performed to determine the appropriate root pressure to maintain the heartbeat without causing deterioration of ventricular function. Study 1. Under partial CPB, the ascending aorta was cross-clamped in 6 pigs (group 1). Experimental data at various systolic aortic root pressures was analysed to determine the appropriate root pressure. Study 2. In group 2 (control, n＝6), the aorta was not clamped, while in group 3 (n＝6), the aorta was cross-clamped for 60 min and the systolic aortic root pressure was maintained at the pressure determined in study 1. Study 1. The diastolic coronary flow was stabilized at values comparable to that before initiation of CPB (6.6±1.4ml/beat) when the systolic aortic root pressure was above 80mmHg. Intracardiac pressure and the myocardial oxygen consumption (MvO2) seemed to be acceptable when the systolic aortic root pressure was below 100mmHg. Therefore, 90mmHg was selected for study 2. Study 2. Perioperative cardiac function did not differ between the groups. We concluded that 90mmHg was the systolic aortic root pressure appropriate for this method

A primary aorto-duodenal fistula associated with an inflammatory abdominal aortic aneurysm: a case report.

Primary aorto-enteric fistula (PAEF)is a serious complication of abdominal aortic aneurysm(AAA). We report a patient with PAEF associated with inflammatory AAA who underwent emergent surgery. A 52-year-old male presented with recurrent hematemesis. A computer tomography scan showed a sealed rupture of the AAA adjacent to the duodenum. At surgery, a coin-sized PAEF was noted. The aorta was replaced with a Dacron graft in situ . Histological examination revealed the characteristics of an inflammatory AAA. The postoperative course was uneventful, and there has been no evidence of infection during a follow-up period of 3 years. We discuss the etiologic and surgical considerations regarding this unusual entity.</p

Efficacy of MCI-186, a free-radical scavenger and antioxidant, for resuscitation of nonbeating donor hearts

ObjectiveOxygen-derived free radicals are responsible in part for reperfusion injury in globally ischemic myocardium. In this study, the efficacy for resuscitation of nonbeating donor hearts of MCI-186, a free-radical scavenger and antioxidant, was investigated in a pig transplantation model.MethodsCardiac arrest was induced by asphyxiation. After 30 minutes of global ischemia, the hearts were excised and immediately reperfused from the aortic root with normoxemic blood cardioplegia (Po2 100 mm Hg) for 20 minutes, followed by perfusion with hyperoxemic blood (Po2 300 mm Hg). MCI-186 (3 mg/kg) was administered into the aortic root for the first 30 minutes of reperfusion in the treated group (n = 6), and untreated hearts were used as a control group (n = 6). Transplantation was performed with the heart beating.ResultsPosttransplantation recovery of cardiac output, end-systolic pressure–volume ratio, and first derivative of pressure of the left ventricle in the treated group were significantly better than those in the control group. The coronary sinus–aortic root difference in malondialdehyde levels remained low throughout reperfusion in the treated group but abruptly increased after initiation of oxygenated blood perfusion in the control group. The MCI-186–treated hearts showed low degree of edema and well-preserved ultrastructure with normal-appearing organelles, whereas the untreated hearts had marked swelling of mitochondria and scant glycogen granules.ConclusionMCI-186 exerts a cardioprotective action at least partly by inhibition of lipid peroxidation. Antioxidant therapy at the initial reperfusion is essential to successful resuscitation of nonbeating hearts by continuous myocardial perfusion

Early outcomes of moderate-to-high-risk pediatric congenital cardiac surgery and predictors of extracorporeal circulatory life support requirement

BackgroundCardiopulmonary failure refractory to medical management after moderate-to-high-risk congenital cardiac surgery may necessitate mechanical support with veno-arterial extracorporeal membrane oxygenation (ECMO). On the extreme, ECMO can also be initiated in the setting of cardiac arrest (extracorporeal cardiopulmonary resuscitation, ECPR) unresponsive to conventional resuscitative measures.MethodsThis was a single-center retrospective cohort study of patients (n = 510) aged &lt;3 years old who underwent cardiac surgery with cardiopulmonary bypass with a RACHS-1 score ≥3 between 2011 and 2014. Perioperative factors were reviewed to identify predictors of ECMO initiation and mortality in the operating room (OR) and the intensive care unit (ICU).ResultsA total of 510 patients with a mean surgical age of 10.0 ± 13.4 months were included. Among them, 21 (4%) patients received postoperative ECMO—12 were initiated in the OR and 9 in the ICU. ECMO cannulation was associated with cardiopulmonary bypass duration, aortopulmonary shunt, residual severe mitral regurgitation, vaso-inotropic score, and postprocedural lactate (p &lt; 0.001). Of the 32 (6%) total deaths, 7 (22%) were ECMO patients—4 were elective OR cannulations and 3 were ICU ECPR. Prematurity [hazard ratio (HR): 2.61, p &lt; 0.01), Norwood or Damus–Kaye–Stansel procedure (HR: 4.29, p &lt; 0.001), postoperative left ventricular dysfunction (HR: 5.10, p = 0.01), residual severe tricuspid regurgitation (HR: 6.06, p &lt; 0.001), and postoperative ECMO (ECPR: HR: 15.42, p &lt; 0.001 vs. elective: HR: 5.26, p = 0.01) were associated with mortality. The two patients who were electively cannulated in the ICU survived.DiscussionAlthough uncommon, postoperative ECMO in children after congenital cardiac surgery is associated with high mortality, especially in cases of ECPR. Patients with long cardiopulmonary bypass time, residual cardiac lesions, or increased vaso-inotropic requirement are at higher risk of receiving ECMO. Pre-emptive or early ECMO initiation before deterioration into cardiac arrest may improve survival

Persistent fenestration may be a marker for physiologic intolerance after Fontan completion

BackgroundWe sought to evaluate the medium-term implications of fenestration status.MethodsBetween 1994 and 2012, 326 patients received an extracardiac Fontan (hospital mortality n = 6, 1.8%). A fenestration was routinely created (n = 306, 94%) unless there was technical difficulty. Three hundred patients discharged with an open fenestration were included. The primary end points were death and Fontan failure. Secondary outcomes were Fontan complications such as venovenous collaterals, protein-losing enteropathy, pacemaker requirement, and arrhythmias.ResultsThe fenestration was closed in 260 patients: 185 as a catheter intervention (62%) and 75 (25%) spontaneously. Forty patients (13%) had the fenestration open at a median follow-up period of 5.05 years. Of these patients, catheter-based closure failed in 10 (3%). There was no statistically significant difference in pre-Fontan hemodynamic parameters, such as pulmonary artery pressure and pulmonary vascular resistance between the patients with open fenestration and the ones with closed fenestration. Patients with an open fenestration had significantly more late deaths (P < .001), Fontan failure (P = .021), and Fontan complications (P = .011) compared with those with a closed fenestration. Multivariable Cox regression revealed open fenestration (P < .001) and indeterminate ventricular morphology (P = .002) as risk factors for death/Fontan failure, and ventricular dysfunction (P = .014) and open fenestration (P = .009) as risk factors for Fontan complications.ConclusionsPersistent fenestration was a marker for physiologic intolerance as noted by increased rates of mortality and a higher incidence of Fontan failure/complications. The specificity of pre-Fontan physiologic data for fenestration status may not have the fidelity needed for long-term care and thus, the consequences of decision making regarding fenestration status may not be determined until well after the operation

Hybrid Palliation for Neonates With Hypoplastic Left Heart Syndrome: Current Strategies and Outcomes

In the last decade the hybrid procedure has emerged as an alternative stage I palliation in neonates with hypoplastic left heart syndrome (HLHS). This review discusses the historical aspect, surgical and interventional techniques, current outcomes and future direction of this procedure. Hybrid palliation yields equivalent but not superior stage I palliation survival and comparable 1-year survival to conventional Norwood palliation, comparable prestage II hemodynamics and pulmonary artery growth, and preserved ventricular function in stage II palliation. Hybrid palliation utilizes significantly less resource and shortens postoperative recovery. In comprehensive stage II palliation the impact of pulmonary artery reconstruction on subsequent pulmonary artery growth has not been determined and should be further investigated. A prospective, randomized trial is warranted to compare these two surgical strategies for neonates with hypoplastic left heart syndrome

Late functional outcomes after repair of tetralogy of Fallot with atrioventricular septal defect: A double case-match control study

ObjectivesWe sought to elucidate late functional outcomes of the right ventricular outflow tract and atrioventricular valves after repair of tetralogy of Fallot with atrioventricular septal defect.MethodsFrom 1990 to 2010, the data from 41 patients who underwent repair were retrospectively reviewed. The median age at repair was 22.4 months (interquartile range, 10.8-41.6 months). Of the 41 patients, 13 (32%) had received previous palliations. The preoperative anatomic differences, physiologic differences, and long-term functional outcomes were determined using a double case-matched control with isolated tetralogy of Fallot and isolated atrioventricular septal defect.ResultsThe right ventricular outflow tract was reconstructed, with the pulmonary valve preserved in 23 patients (56%). There were 3 early deaths and no late deaths. Survival was 92.1% at 15 years. During a median follow-up period of 5.9 years (interquartile range, 0.14-13.7 years), 29 reinterventions were performed in 13 (32%) patients. Freedom from all reintervention at 15 years was 52.8%. Of the 29 procedures, 12 (41%) were related to the right ventricular outflow tract. Freedom from right ventricular outflow tract-related reintervention was greater in patients who had their pulmonary valve preserved (95% vs 70% at 10 years; P = .046). Reinterventions were performed for the atrioventricular valve in 2 (5%) patients and subaortic stenosis in 1 (2%) patient. Freedom from right ventricular outflow tract-related reintervention (tetralogy of Fallot with atrioventricular septal defect, 88.6% vs tetralogy of Fallot alone, 83.9% at 5 years; P = .809) and atrioventricular valve/left ventricular outflow tract-related reintervention (tetralogy of Fallot with atrioventricular septal defect, 95.2% vs atrioventricular septal defect alone, 86.0% at 5 years; P = .332) were comparable between the tetralogy of Fallot with atrioventricular septal defect and matched control groups.ConclusionsLate survival and atrioventricular valve function after repair of tetralogy of Fallot with atrioventricular septal defect were excellent. Pulmonary valve preservation and avoidance of an artificial conduit were associated with greater freedom from right ventricular outflow tract reintervention. In the current era, the surgically modified history of tetralogy of Fallot with atrioventricular septal defect is not significantly different from that of isolated tetralogy of Fallot or isolated atrioventricular septal defect

Biventricular structural and functional responses to aortic constriction in a rabbit model of chronic right ventricular pressure overload

Objectives: Chronic right ventricular (RV) pressure overload results in pathologic RV hypertrophy and diminished RV function. Although aortic constriction has been shown to improve systolic function in acute RV failure, its effect on RV responses to chronic pressure overload is unknown. Methods: Adjustable vascular banding devices were placed on the main pulmonary artery and descending aorta. In 5 animals (sham group), neither band was inflated. In 9 animals (PAB group), only the pulmonary arterial band was inflated, with adjustments on a weekly basis to generate systemic or suprasystemic RV pressure at 28 days. In 9 animals, both pulmonary arterial and aortic devices were inflated (PAB+AO group), the pulmonary arterial band as for the PAB group and the aortic band adjusted to increase proximal systolic blood pressure by approximately 20 mm Hg. Effects on the functional performance were assessed 5 weeks after surgery by conductance catheters, followed by histologic and molecular assessment. Results: Contractile performance was significantly improved in the PAB+AO group versus the PAB group for both ventricles. Relative to sham-operated animals, both banding groups showed significant differences in myocardial histologic and molecular responses. Relative to the PAB group, the PAB+AO group showed significantly decreased RV cardiomyocyte diameter, decreased RV collagen content, and reduced RV expression of endothelin receptor type B, matrix metalloproteinase 9, and transforming growth factor beta genes. Conclusions: Aortic constriction in an experimental model of chronic RV pressure overload not only resulted in improved biventricular systolic function but also improved myocardial remodeling. These data suggest that chronically increased left ventricular afterload leads to a more physiologically hypertrophic response in the pressure-overloaded RV. (J Thorac Cardiovasc Surg 2012;144:1494-501)Deutsche Herzstiftung e.V., Frankfurt, German