Giuseppe D'Ancona

Primary Graft Failure After Heart Transplantation: The Importance of Donor Pharmacological Management

BACKGROUND Primary graft failure (PGF) remains the strongest determinant of perioperative mortality after heart transplantation (HT). Donor management may play an important role in the incidence of PGF. MATERIALS AND METHODS Multivariate analysis was used to identify PGF determinants after HT. Donor and recipient data were analyzed together with preharvest management information and perioperative results. PGF was defined as the need for mechanical circulatory support immediately post-HT. RESULTS Isolated HT was performed in 54 consecutive patients from January 2006 to June 2009. PGF occurred in 11 (20%) patients. Upon univariate analysis, preoperative mean pulmonary arterial pressure was significantly higher among patients developing PGF (P=.02). The donors for PGF patients had more often been managed with high inotropic support (dopamine>10 microg/kg/min and/or alpha agonists>0.06 microg/kg/min; P=.008). In contrast, death for head trauma was more common among donors for patients who did not develop PGF (P=.02). In-hospital mortality was 13% (7/54); 71% of these deceased patients displayed PGF (5/7). Upon multivariate analysis, preharvest high donor inotropic support was the strongest determinant of PGF (P=.01, odds ratio [OR]=7.5). Donor death due to head trauma showed a protective effect against PGF (P=.03, OR=0.1). CONCLUSION PGF remains a lethal perioperative complication despite modern tools for prompt cardiac mechanical assistance. As a result of the organ shortage, many centers accept marginal hearts assuming that donor hemodynamic management shows a reduced impact on PGF. We suggest a timely evaluation of the hazards for PGF whenever high inotropic support is used, especially among donors dying for causes other than head trauma.

Donor pharmacological hemodynamic support is associated with primary graft failure in human heart transplantation

The aim of this study was to test the impact of donor and recipient characteristics on the development of primary graft failure (PGF) after heart transplantation (HT) by focusing on the donors inotropic support. Heart donors and matched recipients data were prospectively collected. Univariate and multivariate analyses were used to determine independent predictors for PGF and peri-operative mortality. The donors high inotrope requirement was defined as sustained need for dopamine exceeding 10 microg/kg/min and/or alpha agonists exceeding 0.06 microg/kg/min. PGF instead was defined as need for immediate post-HT mechanical circulatory support. Since 2006, we have performed 37 HTs. PGF occurred in six patients (16.2%). Although four patients (66.6%) were weaned off circulatory support, two of them (33.3%) died on mechanical assistance. Total in-hospital mortality was 10.8% (4/37). Upon multivariate analysis, pre-harvesting donor high inotrope dosage was the major determinant for PGF (P=0.03, OR=10.8). Given the organ shortage, many centers accepted marginal hearts assuming the donors pre-harvest hemodynamic managing has a reduced impact on PGF development. As PGF remains the most lethal postoperative complication, the hazards should be carefully considered when using pre-harvesting high inotrope infusion rates.

Aortic valve repair for aortic insufficiency: a review.

r c r d i AORTIC INSUFFICIENCY (AI) refers to the backward leaking of blood through the aortic valve (AV) during iastole. AI can be treated with many techniques that repair r replace the AV and modify the structural dimensions of he aortic root and ascending aorta. Based on the anatomy of n individual patient, a combination of surgical approaches ay be used to repair an AI. It is common to use multiple repair methods based on an ndividual patient’s specific pathology and the mechanisms of I. Although AV replacement (AVR) remains the most comon surgery to treat AI, valve repair has become increasingly ommon despite its technical demands. The resurgence of AV epair may be attributed to the desire to avoid the downfalls of eplacement and the increasing experience with the reparative rocedures. Furthermore, a native AV repair theoretically could ndergo slower valve degeneration compared with a bioproshesis. These issues are especially important in younger patients ho undergo AVR and are exposed to a more extended risk of leeding and repeat surgery. The present report reviews the anatomy of the AV, the athophysiology of AI, and the surgical indications in patients ith AI. Furthermore, surgical repair options, outcomes of epair and replacement, and postoperative evaluation of paients undergoing AV repair for AI are discussed.

Ischemic mitral valve regurgitation in patients with depressed ventricular function: cardiac geometrical and myocardial perfusion evaluation with magnetic resonance imaging

OBJECTIVE To investigate geometrical and functional changes involving the left ventricle (LV) and mitral valve (MV) apparatus in patients with depressed LV ejection fraction (LVEF) and ischemic MV regurgitation (IMVR). METHODS A series of patients with three vessels coronary artery disease (CAD) and depressed LVEF underwent cardiac magnetic resonance imaging to investigate MV/LV geometry and function, and myocardial perfusion/vitality. Geometrical data were indexed by anterior MV leaflet length. Two groups were identified: CAD without IMVR (group CAD), and with IMVR (group IMV). RESULTS Eleven patients were enrolled in the CAD group and 13 in the IMV group. IMVR volume was significantly higher in the IMV group (24.0+/-12.0 vs 4.5+/-5.2; p<0.0001). LVEF% was comparable (IMV 34.6+/-13.0 vs CAD 31.5+/-13.0; p=ns). Indexed MV/LV geometrical variables were comparable in the two groups. Perfusion/vitality study showed inferior myocardial necrosis occurred more often in the IMV group (p=0.01). At Pearson test, MV regurgitation occurrence correlated with inferior myocardial necrosis (r=0.5; p=0.006), non-indexed systolic/diastolic annular inter-commissural diameters (r=0.4; p=0.04) and MV annular areas (r=0.4; p=0.04). Papillary muscles distance (PMD) and LV volumes inversely correlated with LVEF% (r=-0.6; p<0.05 and r=-0.8; p<0.001). At multivariable analysis, no independent determinants for IMVR were identified and LV volumes were the sole determinants for LVEF% (p<0.05). CONCLUSION In patients with depressed LVEF%, IMV cannot be explained by LV geometrical modifications alone. Although PMD, LV volumes, and LVEF% are correlated, they have no direct impact in the development of IMVR. In contrast, inferior myocardial necrosis and increased inter-commissural MV diameters may lead to deformity of MV complex and subsequent IMV.

Intraoperative Graft Patency Verification in Coronary Artery Surgery: Modern Diagnostic Tools

HE STANDARD OF CARE in modern medicine is supported by many quality control tools, and intraoperative graft patency testing after coronary artery surgery can be proposed, in this context, as part of the operation documenting the success of the procedure itself. The aim of coronary artery bypass graft (CABG) surgery is to increase blood flow to the ischemic myocardium. This statement makes more of an impact if it is realized that 5% to 20% of all grafts performed fail before discharge from the hospital and up to 30% before 1 year 1,2 without any objective evidence that these grafts were actually patent in the operating room. Many of these early failures are probably secondary to technical issues that could be solved promptly if adequately diagnosed intraoperatively. Although there are no data available in the literature documenting the actual utilization rate of intraoperative coronary artery graft patency verification tools, a survey conducted on a limited sample of cardiac surgeons has shown some interesting figures.3 The majority (68.1%) of those interviewed stated that manual palpation of the grafts is their current method to detect graft patency after CABG surgery; 70% of the surgeons included had never used an intraoperative graft patency verification tool in their practice. Most of the surgeons interviewed thought that graft flowmeters are often difficult to use, interpretation of the findings is unclear, and revision rates are low enough that graft patency verification seems unnecessary. Although the majority declared that a flowmeter is not routinely necessary, 86% of them interestingly stated that it is important to have a system available in the operating room. 3 Being complementary to percutaneous coronary intervention, cardiac surgery has lost its supremacy in the treatment of coronary artery disease, and cardiac surgeons should concentrate on how to optimize the quality of care they are providing. This article reviews the methods that are currently available to intraoperatively test and document the status of newly constructed coronary anastomoses. A clear distinction is made between imaging techniques and flow-assessment devices.

Epicardial coronary artery Doppler: validation in the animal model

The aim of the study was to validate a newly-designed epicardial coronary artery Doppler probe and test its detection of changes in coronary blood flow velocity. Left anterior descending (LAD) coronary blood flow and flow velocity were evaluated in four pigs with a pericoronary transit time flow (TTF) probe and a newly-designed epicardial Doppler micro-probe. Four consecutive measurements were taken for each of the following conditions: basal, partial stenosis, occlusion, and reperfusion of the LAD. Mean TTF value (ml/min) was 23.2+/-6.6 in basal condition, 16.2+/-5.7 after partial LAD stenosis, 0.1+/-0.3 during LAD occlusion, and 67.4+/-23.3 at reperfusion (P<0.001). Similar patterns were recorded in terms of Doppler velocity (cm/s) with values of 4.0+/-1.9 in basal condition, 3.5+/-2.3 after partial LAD stenosis, 0.5+/-1.4 during LAD occlusion, and 11.1+/-5.5 at reperfusion (P<0.001). No significant differences in both TTF and Doppler velocity were detected between basal condition and partial LAD stenosis (P=ns). Epicardial coronary arterial Doppler represents a valuable tool to detect coronary arterial flow velocity in basal condition. Although changes in flow velocity are easily recorded after coronary occlusion and reperfusion, modifications after partial coronary stenosis are not clearly defined.

An In Vitro Phantom Study on the Role of the Bird-Beak Configuration in Endograft Infolding in the Aortic Arch

Purpose: To assess endograft infolding for excessive bird-beak configurations in the aortic arch in relation to hemodynamic variables by quantifying device displacement and rotation of oversized stent-grafts deployed in a phantom model. Methods: A patient-specific, compliant, phantom pulsatile flow model was reconstructed from a patient who presented with collapse of a Gore TAG thoracic endoprosthesis. Device infolding was measured under different flow and pressure conditions for 3 protrusion extensions (13, 19, and 24 mm) of the bird-beak configuration resulting from 2 TAG endografts with oversizing of 11% and 45%, respectively. Results: The bird-beak configuration with the greatest protrusion extension exhibited the maximum TAG device displacement (1.66 mm), while the lowest protrusion extension configuration led to the minimum amount of both displacement and rotation parameters (0.25 mm and 0.6°, respectively). A positive relationship was found between the infolding parameters and the flow circulating in the aorta and left subclavian artery. Similarly, TAG device displacement was positively and significantly (p<0.05) correlated with the pulse pressure for all bird-beak configurations and device sizes. However, no collapse was observed under chronic perfusion testing maintained for 30 days and pulse pressure of 100 mm Hg. Conclusion: These findings suggest that endograft infolding depends primarily on the amount of aortic pulsatility and flow rate and that physiological flows do not necessarily engender hemodynamic loads on the proximal bird-beak segment sufficient to cause TAG collapse. Hemodynamic variables may allow for identification of patients at high risk of endograft infolding and help guide preventive intervention to avert its occurrence.

Hybrid treatment of inferior vena cava obstruction after orthotopic heart transplantation.

Caval stenosis with subsequent thrombosis may occur after orthotopic heart transplantation (HT). Management of this complication may include a percutaneous approach or an open surgical one. Here, we report the case of an obstruction and severe thrombosis of the inferior vena cava, following orthotopic HT, that was managed in a hybrid fashion with surgical venous thrombectomy, inferior vena cava stenting, and atrio-caval patch-plasty.

Circulatory support system as a bridge to decision in patients with refractory acute cardiogenic shock: Is there a space for extracorporeal membrane oxygenation?

a bridge to decision in patients with refractory acute cardiogenic shock: Is there a space for extracorporeal membrane oxygenation? To the Editor: We read with interest the timely report by John and colleagues about the elective use of the Levitronix CentriMag as a bridge to decision in cardiogenic shock. We commend them for their encouraging results in 12 patients assisted with biventricular support. Although the concept of cardiac assistance as bridge to decision is well addressed by the authors, we believe that extracorporeal membrane oxygenation (ECMO) could play a more valuable role in this context. This is especially so when the expected assistance time is relatively short (eg, an average support length of 9.4 days, as reported in John and colleagues’ experience). In our institution, we routinely use both ECMO and the Levitronix device. The latter is mainly used for patients with postcardiotomy syndrome or primary graft failure; we advise the use of ECMO in nonsurgical situations, such as cardiogenic shock after acute myocardial infarction or failed percutaneous coronary interventions. In this selected group of patients, ECMO offers some advantages. These include avoidance of sternotomy and central cannulation, which may cause catastrophic bleeding after aggressive thrombolysis and antiplatelet treatment, and ease of emergency implantation, even in the intensive care unit or catheter laboratory, with consequent rapid institution of assistance. Furthermore, newly designed oxygenators and ECMO circuits (Quadrox Jostra, Permanent Life Support PLS; MAQUET GmbH & Co KG, Rastatt, Germany) require a lower priming volume and present a bioinert surface treatment, guaranteeing assistance for an extended 14 days with a reduced risk of device-related complications and a less strict anticoagulation regimen. Moreover, ECMO can be easily switched to cardiopulmonary bypass at the time of transplantation or long-term device implantation. In our institution, since the beginning of 2006, the PLS ECMO system has been extensively used to treat either lung (6 patients) or cardiac (8 patients) failure (venovenous and venoarterial cannulation, respectively). No device failures have been recorded, even for assistance extending longer than 60 days. In our experience, ECMO units are managed by intensive care unit nurses, and dedicated personnel are usually not required. Activated thromboplastin time is kept between 40 and 50 seconds, with a level of antithrombin III activity greater than 80%. In cases of bleeding, we have withheld heparin for more than 30 hours without any thrombotic events. Leg ischemia, related to common femoral artery cannulation, is the complication we have seen most frequently. In most cases, however, this condition can be resolved by cannulating the superficial femoral artery as well with a small perfusion cannula. In conclusion, although the many advantages offered by the Levitronix pump are remarkable, patient-tailored assistance can be achieved for selected candidates with new versions of ECMO systems, such as the PLS. Thanks to modern technology, these systems couple ease of implantation and management with device reliability and long-term durability.