Stress echocardiography as a gatekeeper to donation in aged marginal donor hearts: anatomic and pathologic correlations of abnormal stress echocardiography results.

BACKGROUND: Owing to the shortage of donor hearts, the criteria for acceptance have been considerably expanded. Pharmacologic stress echocardiography is highly accurate in identifying prognostically significant coronary artery disease, but brain death and catecholamine storm in potential heart donors may substantially alter the cardiovascular response to stress. This study assessed correlates of an abnormal resting/stress echocardiography results in potential donors. METHODS: From April 2005 to December 2007, 18 marginal candidate donors (9 men) aged 58 +/- 5 years were initially enrolled. After legal declaration of brain death, all marginal donors underwent bedside echocardiography, with baseline and (when resting echocardiography was normal) dipyridamole (0.84 mg/kg in 6 min) or dobutamine (up to 40 microg/kg/min) stress echo. Non-eligible hearts (with abnormal rest or stress echo findings) were excluded and underwent cardioautoptic verification. RESULTS: Resting echocardiography showed wall motion abnormalities in 5 patients (excluded from donation). Stress echocardiography was performed in the remaining 13 (dipyridamole in 11; dobutamine in 2). Results were normal in 7, of which 6 were uneventfully transplanted in marginal recipients. Results were abnormal in 6, and autoptic verification performed showed coronary artery disease in 5, and initial cardiomyopathy in 1. CONCLUSIONS: Bedside pharmacologic stress echocardiography can safely be performed in candidate heart donors, is able to unmask occult coronary artery disease or cardiomyopathy, and shows potential to extend donor criteria in heart transplantation. Further experience with using marginal donors is needed before exact guidelines can be established.

Pulmonary endarterectomy: an alternative to circulatory arrest and deep hypothermia: mid-term results.

BACKGROUND: The current surgical technique for pulmonary endarterectomy (PEA) involves the use of deep hypothermia and circulatory arrest at 18 degrees C (DHCA). Our experience started in 2004 when we decided to use an original alternative strategy which consists of avoiding deep hypothermia and subsequent circulatory arrest by using moderate hypothermia at 26 degrees C, and maintaining a bloodless field. This can be achieved by means of negative pressure in the left heart chambers and appropriate pump flow modulation in order to maintain the mixed venous oxygen saturation (SVO(2)) higher than 65%. MATERIALS AND METHODS: From June 2004 to June 2007, 40 consecutive patients were operated on in our department with this strategy. The aim of this article is to report the early results for all patients and the complete six-month follow-up for 30 subjects who have reached this end-point at the time of writing. The mean temperature during extracorporeal circulation was 25.9 degrees C; core temperature was lowered to 21 degrees C in only one patient and an 8 min DHCA was performed in order to complete the PEA. RESULTS: Two patients died (6.6%): one on the third postoperative day due to myocardial infarct, requiring an ECMO implantation. The other patient died from septic shock. The six-month follow-up, performed in all other patients, included clinical and hemodynamic evaluation. Pulmonary vascular resistance (PVR) decreased from 793.5+/-284 dyn/cm/s(-5) to 286+/-143 (p=0.000). A comparable reduction of mean pulmonary arterial pressure and an increase of cardiac output were also observed. CONCLUSIONS: The results confirm that adequate removal of pulmonary artery obstructive lesions can also be achieved with an operative procedure that avoids or reduces the use of DHCA while allowing a bloodless field during PEA interventions. This technique may limit the well known adverse effects of DHCA due to organ hypoperfusion, improving the postoperative recovery of the patients.

Right-left atrium by-pass as salvage treatment for graft failure after heart transplantation.

Chronic functional pulmonary hypertension (FPH) secondary to end-stage cardiomyopathy constitutes a risk factor for graft right ventricular failure (RVF) after orthotopic heart transplantation (HTx). A novel form of mechanical assist circuit, the extracorporeal right to left atrium bypass (ECRLAB), has been proposed. Since 1998, at our institution, a total of six patients with FPH who experienced graft RVF after HTx, as ischemic end-stage cardiomyopathy, during the effort to wean from cardiopulmonary bypass, underwent ECRLAB support. There were five men and one woman with a mean age of 55+/-3.5 years (49-59 years). The Jostra Rota Flow pump was used in five patients and the Bio-Medicus in one. Mean duration of support was 94.3+/-17.5 h (75-126 h). All (100%) patients were successfully weaned from ECRLAB support. Hemodynamic parameters improved in all patients. Two patients died from cerebral haemorrhage. Four (66.6%) patients were successfully discharged home. ECRLAB could be proposed during HTx in patients with increased preoperative transpulmonary gradient to promote the functional adaptation of the graft and avoid graft RVF, until the decline of pulmonary resistances.

Intrapericardial lipoma: successful resection of a giant tumor without cardiopulmonary bypass.

Cardiac lipomas are very rare neoplasms. We describe herein a case of giant intrapericardial extracavitary lipoma in a 67-year-old man who has been previously treated for prostate and kidney cancers. The patient underwent successful resection of the tumor through right anterolateral thoracotomy.

Pulmonary endarterectomy: is there an alternative to profound hypothermia with cardiocirculatory arrest?

The current surgical strategy for pulmonary endarterectomy (PEA) involves the use of extracorporeal circulation and hypothermic circulatory arrest (HCA). The aim of the present study was to test the feasibility of a different strategy of extracorporeal circulation, which could prevent bronchial back bleeding and allow a bloodless operating field, avoiding the risks associated with HCA in patients undergoing pulmonary endarterectomy. Between June 2004 and September 2005, eight patients underwent PEA without HCA. We introduced a double venting of the left heart sections, utilizing two cannulas placed in the left ventricle and atrium. Both vent cannulas are connected with vacuum device to prevent back-bleeding and left heart distension from the large amount of bronchial flow. We were able to perform pulmonary endarterectomy avoiding circulatory arrest and deep hypothermia without sacrificing the effectiveness of the procedure. The initial encouraging results have convinced us to apply systematically this technique in the cases operated in our center, even though further investigations are necessary to fully examine this technique.

BIOSA bileaflet pericardial valve: experimental study in sheep model.

BACKGROUND: BIOSA is a single sheet, two-cuspal-shaped ("bileaflet") glutaraldehyde fixed bovine pericardial valve prosthesis (BP), designed to minimize stress and prevent mechanical failure. We tested this device in the adult sheep model. METHODS: Seven BIOSA and two Baxter Carpentier-Edwards (Perimount) pericardial BPs, 25 mm in size, were implanted in the tricuspid position of adult sheep. A mid term BIOSA explant (81 days) died of infective endocarditis. The remaining BPs were divided in three early explants (0-3 days: two BIOSA and one Perimount) and five late explants (162-189 days: four BIOSA and one Perimount). Protocol of the study included gross examination, mammography X-ray (score 0-4), histology, scanning (SEM) and transmission (TEM) electron microscopy and atomic absorption spectroscopy. RESULTS: (a) Early explants: The mesothelium was detached, collagen-elastic fibers and pericardiocytes of the fibrosa showed optimal preservation. Calcium content in BIOSA BPs was 6.22 mg/g dry weight (mean) versus 7.75 mg/g of the Perimount BP. (b) Late explants: At naked eye all BPs showed regular cusp pliability and coaptation, without tears, perforations, fibrous pannus or calcific deposits. X-ray was either negative (three BPs) or exhibited score 1 (two BPs). Microscopic features were excellent both in terms of collagen-elastic fibers preservation and absence of inflammation. The calcium content was 4.95 mg/g dry weight (mean) in BIOSA BPs versus 5.29 mg/g in the Perimount BP. CONCLUSIONS: Tissue characteristics of BIOSA BPs were optimal, without difference with Perimount BPs and in this animal model no case of structural valve deterioration occurred in the long term.