Edward Buratto

Physiological Performance of a Detergent Decellularized Heart Valve Implanted for 15 Months in Vietnamese Pigs: Surgical Procedure, Follow‐up, and Explant Inspection

This study features the longest experimental follow-up for decellularized heart valves implanted in an animal model. Porcine aortic heart valves were decellularized according to a disclosed standardized method in which TRITON X-100 and sodium cholate (TRICOL) are used in succession, followed by a further treatment with the endonuclease Benzonase to completely remove the nucleic acid remnants. Experimental animals (n = 17), represented by Vietnamese pigs (VPs), received a decellularized aortic allograft as a substitute for the replacement of their right ventricular outflow tract. The surgical implantation of the TRICOL-treated aortic valve conduit was successful in 11 VPs, while perioperative or postoperative complications occurred in the remaining six animals. In the sham-operated group (n = 4), the native pulmonary root was excised and immediately reimplanted orthotopically in the same animal. Echocardiography demonstrated a satisfactory hemodynamic performance of the TRICOL-treated valves during follow-up as well as the absence of relevant leaflet alterations concerning thickness and motility or valve insufficiency. At explantation, macroscopic inspection of tissue-engineered heart valve conduits did not evidence calcifications and showed a decreased wall thickness, comparable to that of the reimplanted native pulmonary roots. Noteworthy, extended functional performance, recovery of DNA content, and active extracellular matrix precursor incorporation are apparently compatible with the properties of a living self-supporting substitute.

Repair of partial atrioventricular septal defect: a 37-year experience

OBJECTIVES Partial atrioventricular septal defect (pAVSD) is routinely repaired with a low mortality. However, limited data are available on the long-term follow-up of these patients. The current study was designed to determine long-term survival and morbidity of a large cohort of patients operated on at a single institution. METHODS From 1975 to 2012, 249 consecutive patients underwent pAVSD repair at the Royal Childrens Hospital. The follow-up data were obtained from hospital records, correspondence with cardiologists and primary care physicians, patient surveys and the state death registry. RESULTS The early mortality rate was 1.2% (3/249), while the long-term survival rate was 96% (95% CI: 93-98%) at 10 years and 94% (95% CI: 89-97%) at 30 years. Freedom from reoperation was 84% at 10 years and 75% at 30 years. The most common reoperations were left atrioventricular valve surgery (30/249, 12.1%), resection of left ventricular outflow tract obstruction (12/249, 4.8%) and closure of residual atrial septal defects (5/249, 2.0%). Implantation of a permanent pacemaker was required in 3.2% (8/249) of patients. Despite a substantial reoperation rate, only 43% of patients older than 18 years of age were seen by a cardiologist within the most recent 2 years of the study period, compared with 80% of those younger than 18 years (P < 0.001). CONCLUSIONS Repair of pAVSD is performed with a low mortality and excellent long-term survival. However, a substantial reoperation rate warrants close follow-up into adulthood.

Hemorrhage and thrombosis with different LVAD technologies: a matter of flow?

BACKGROUND Much of the morbidity and mortality associated with ventricular assist devices (VADs) is due to haemorrhagic and thrombotic complications. To manage antithrombotic therapy, interactions between the patient and pump should be better understood. METHODS We have compared the Jarvik 2000, an axial flow left ventricular assist device (LVAD), with the HeartWare ventricular assist device (HVAD) centrifugal pump, regarding conventional laboratory findings, thromboelastometric and aggregometric tests. RESULTS Patients with the Jarvik 2000 experienced a significant reduction in platelet count following implantation, a phenomenon not seen with the HeartWare model. Conversely, we observed that levels of platelet activation, as assessed by a platelet function analyzer, and activation of the coagulation system, as assessed by thromboelastometry, were significantly greater in the HeartWare group. CONCLUSIONS It seems that axial flow pumps, being more destructive on blood cells, tend to reduce platelet numbers. On the other hand, centrifugal flow is associated with a hypercoagulable state, possibly resulting from the activation of the coagulation system in the absence of platelet destruction.

Impact of vacuum-assisted closure therapy on outcomes of sternal wound dehiscence †

OBJECTIVES Sternal wound dehiscence (SWD) after cardiac surgery is a rare but serious condition associated with considerable costs and morbidity. We sought to evaluate the results of the introduction of vacuum-assisted closure (VAC) therapy in the management of sternal wound dehiscence, compared with those of previous conventional treatments. METHODS We retrospectively collected 7148 patients who underwent cardiac surgery at our institution between January 2002 and June 2012. A total of 152 (2.1%) patients had a sternal wound dehiscence: 107 were treated with conventional treatments (Group A) and 45 were managed with VAC therapy (Group B). Patients were stratified according to preoperative risk factors and type of sternal wound dehiscence (superficial or deep; infected or not) and compared by means of a propensity-matched analysis. A cost analysis was also performed. RESULTS Forty-five patients of each group matched for all preoperative risk factors and type of sternal wound dehiscence. SWD-related mortality rate was significantly lower in Group B (11 vs 0%; P = 0.05). Incidence of mediastinitis (P < 0.0001), sepsis (P = 0.04), delayed SWD infection (P = 0.05), other complication (P = 0.05), surgical sternal revision (P = 0.04) and surgical superficial revision (P < 0.0001) were all significantly lower in Group B. Mean patient cost was 31 106€ in Group A and 24 383€ in Group B, thus achieving a mean saving of 6723€ per patient. CONCLUSIONS In our experience, the use of VAC therapy for the management of SWD was considerably effective in decreasing mortality (SWD related), incidence of complications and need for surgical procedures; thus, leading to a significant reduction of costs.

Long-term outcomes of single-ventricle palliation for unbalanced atrioventricular septal defects: Fontan survivors do better than previously thought

Background: Single‐ventricle palliation (SVP) for children with unbalanced atrioventricular septal defect (uAVSD) is thought to carry a poor prognosis, but limited data have been reported. Methods: We performed a retrospective review of children with uAVSD who underwent SVP at a single institution. Data were obtained from medical records and correspondence with general practitioners and cardiologists. Results: Between 1976 and 2016, a total of 139 patients underwent SVP for uAVSD. A neonatal palliative procedure was performed in 83.5% of these patients (116 of 139), and early mortality occurred in 11.2% (13 of 116). Ninety‐four patients underwent stage II palliation, with an early mortality of 6.4% (6 of 94). Eighty patients (57.6%) underwent Fontan completion, with an early mortality of 3.8% (3 of 80). Interstage mortality was 11.7% (12 of 103) between stages I and II and 17.0% (15 of 88) between stage II and Fontan. Long‐term survival was 66.5% (95% confidence interval [CI], 57.9%‐73.9%) at 5 years, 64.4% (95% CI, 55.5%‐72.0%) at 15 years, and 57.8% (95% CI, 47.5%‐66.8%) at 25 years. Survival post‐Fontan was 94.9% (95% CI, 86.9%‐98.0%) at 5 years, 92.0% (95% CI, 80.6%‐96.8%) at 15 years, and 82.4% (95% CI, 61.5%‐92.6%) at 25 years. Risk factors associated with death or transplantation were aortic atresia (hazard ratio [HR], 5.3; P = .03) and hypoplastic aortic arch (HR, 2.5; P = .02). Atrioventricular valve operations were required in 31.7% of the patients (44 of 139), with 31.8% of them (14 of 44) requiring a further operation. Conclusions: Children undergoing SVP for uAVSD have substantial mortality, with <60% survival at 25 years. However, survival of children who achieve Fontan completion is better than has been reported previously.

Implantation of the HeartWare HVAD: from full sternotomy to less invasive techniques.

Left ventricular assist devices (LVADs) are increasingly used for the treatment of end-stage congestive heart failure, both as a bridge to transplantation and as destination therapy (1). The HeartWare HVAD (HeartWare Inc, Framingham, MA, USA) is a continuous centrifugal-flow left ventricular assist device with a magnetic levitating rotor pump. The pump weighs just 140 g and its small design allows for intra-pericardial placement. It is powered by two portable batteries that connect to the pump via a driveline tunneled through the abdominal wall, and these can be worn on a belt, allowing out of hospital support (2). The HVAD is currently indicated for use in patients with refractory end stage congestive heart failure. We outline two techniques for implanting the HeartWare HVAD: via a full median sternotomy, and using minimal access incision (Video 1). Video 1 Implantation of the HeartWare HVAD: from full sternotomy to less invasive techniques. Case 1 Clinical vignette A 56-year-old man with refractory shock due to end-stage dilated cardiomyopathy was transferred to our institution. He was initially placed on peripheral veno-arterial Extra-Corporeal Membrane Oxygenator (ECMO), as a bridge to decision, and then underwent implantation of a HeartWare HVAD as a bridge to transplantation. After three months of HVAD support, he underwent successful heart transplantation.

From bench to bedside: Can the improvements in left ventricular assist device design mitigate adverse events and increase survival?

OBJECTIVE In vitro tests demonstrated that the new cone-bearing configuration of the Jarvik 2000 (Jarvik Heart Inc, New York, NY) left ventricular assist device exhibits better hydraulic efficiency than the previous pin-bearing design. We investigated the long-term outcomes of patients who received the Jarvik 2000 left ventricular assist device, depending on bearing design. METHODS A retrospective review of prospectively collected data from 18 centers included in the Italian Registry was performed. From May 2008 to September 2013, 99 patients with end-stage heart failure were enrolled. Patients were divided into 2 groups according to their Jarvik 2000 suspending mechanism: Group pin included patients with pin bearings (May 2008 to June 2010), and group cone included patients with newer cone bearings (July 2010 to September 2013). The 2 groups did not differ significantly in terms of baseline characteristics. RESULTS A total of 30 of 39 patients (group pin) and 46 of 60 patients (group cone) were discharged. During follow-up, 6 patients underwent transplantation, and in 1 patient the left ventricular assist device was explanted. The cumulative incidence competing risk of the entire cohort for noncardiovascular-related death was 28% (20%-40%); the cumulative incidence competing risk for cardiovascular-related death was 56% (42%-73%): 71% in group pin versus 26% in group cone (P = .034). The multivariate analyses confirmed that the pin-bearing design was a risk factor for cardiovascular death, along with Interagency Registry for Mechanically Assisted Circulatory Support class. Right ventricular failures and ischemic and hemorrhagic strokes were significantly higher in group pin. CONCLUSIONS Patients with the new pump configuration showed a better freedom from cardiovascular death and lower incidence of fatal stroke and right ventricular failure. Further studies are needed to prove the favorable impact of pump-enhanced fluid dynamics on long-term results.

Successful atrioventricular valve repair improves long-term outcomes in children with unbalanced atrioventricular septal defect

Background: Atrioventricular valve regurgitation is a significant cause of morbidity and mortality in patients with unbalanced atrioventricular septal defect. However, knowledge of the outcomes of atrioventricular valve repair in children with unbalanced atrioventricular septal defect and univentricular physiology is limited. Methods: We conducted a retrospective review of all patients with unbalanced atrioventricular septal defect treated with single‐ventricle palliation who underwent atrioventricular valve surgery at The Royal Childrens Hospital. Results: Between 1976 and 2016, 139 children with unbalanced atrioventricular septal defect underwent single‐ventricle palliation, of whom 31.7% (44/139) required atrioventricular valve surgery. Repair of the atrioventricular valve was attempted in 97.7% (43/44) of patients, of whom 4.7% (2/43) were converted to replacement during the initial operation. Replacement of the atrioventricular valve without attempted repair was performed in 2.3% (1/44) of patients. Early mortality was 18.2% (8/44). Freedom from death or transplantation at 10 years was 66.0% (95% confidence interval, 49.1–78.5) and at 20 years was 53.3% (95% confidence interval, 32.1–70.6). In multivariable analysis, significant predischarge atrioventricular valve regurgitation (hazard ratio, 6.4; P = .002), age less than 1 year (hazard ratio, 8.3; P = .01), and repair before stage II palliation (hazard ratio, 3.4; P = .04) were associated with death. Freedom from reoperation at 10 years was 61.9% (95% confidence interval, 41.9–76.8) and at 20 years was 56.3% (95% confidence interval, 35.3–72.8). Moderate or greater atrioventricular valve regurgitation at discharge was associated with an increased risk of reoperation (hazard ratio, 1.8; P = .03). Of transplant‐free survivors, atrioventricular valve regurgitation was less than moderate in 60.0% (15/25) at the most recent follow‐up. Conclusions: Atrioventricular valve surgery in patients with unbalanced atrioventricular septal defect is associated with substantial mortality and a high rate of reoperation. Successful atrioventricular valve repair is associated with better survival and freedom from reoperation.

Long-term outcomes of reoperations following repair of partial atrioventricular septal defect

OBJECTIVES Partial atrioventricular septal defect (pAVSD) is repaired with excellent long-term survival. However, up to 25% of patients require reoperations. This study reviews results of reoperation following pAVSD repair at a single institution. METHODS From 1975 to 2012, 40 patients (16%, 40/246) underwent reoperation following pAVSD repair at the study institution. The data were retrospectively reviewed. RESULTS The mean time to reoperation was 5.4 ± 5.8 years. The most common reoperations were left atrioventricular valve (LAVV) surgery (78%, 31/40) and resection of left ventricular outflow tract obstruction (20%, 8/40). The most common cause for LAVV surgery was regurgitation through the cleft (58%, 18/31), followed by central regurgitation (29%, 9/31). Most cases of LAVV regurgitation were treated by repair (77%, 24/31), rather than replacement (23%, 7/31). Since the introduction of a patch augmentation technique for LAVV repair in 1998, the rate of repair has increased from 54 to 94% (P = 0.012). The early mortality rate was 2.5% (1/40). The survival rate was 90% (95% CI: 76-96) at 10 years and 83% (95% CI: 60-94) at 20 years. The rate of freedom from further reoperation was 66% (95% CI: 46-80) at 10- and 20-year follow-up. CONCLUSIONS The most common cause for reoperation following pAVSD repair was LAVV regurgitation through the LAVV cleft. Reoperation is performed with survival comparable to that of primary pAVSD repair, yet the rate of further reoperations remains high. The patch augmentation technique for LAVVR has significantly increased the rate of successful LAVV repair.

Single vs double antiplatelet therapy in acute coronary syndrome: Predictors of bleeding after coronary artery bypass grafting.

AIM To investigate the contribution of anti-platelet therapy and derangements of pre-operative classical coagulation and thromboelastometry parameters to major bleeding post-coronary artery bypass grafting (CABG). METHODS Two groups of CABG patients were studied: Group A, treated with aspirin alone (n = 50), and Group B treated with aspirin and clopidogrel (n = 50). Both had similar preoperative, clinical, biologic characteristics and operative management. Classic coagulation parameters and rotational thromboelastometry (ROTEM) profiles were determined preoperatively for both groups and the same heparin treatment was administered. ROTEM profiles (INTEM and EXTEM assays) were analyzed, both for traditional parameters, and thrombin generation potential, expressed by area-under-curve (AUC). RESULTS There was no significant difference between rates of major bleeding between patients treated with aspirin alone, compared with those treated with aspirin and clopidogrel (12% vs 16%, P = 0.77). In the 14 cases of major bleeding, pre-operative classic coagulation and traditional ROTEM parameters were comparable. Conversely we observed that the AUC in the EXTEM test was significantly lower in bleeders (5030 ± 1115 Ohm*min) than non-bleeders (6568 ± 548 Ohm*min) (P < 0.0001). CONCLUSION We observed that patients with a low AUC value were at a significantly higher risk of bleeding compared to patients with higher AUC, regardless of antiplatelet treatment. This suggests that thrombin generation potential, irrespective of the degree of platelet inhibition, correlates with surgical bleeding.