Carlo Pederzolli

Orthotopic heart transplantation: Standard versus bicaval technique

We compared orthotopic heart transplantation (HT) by bicaval technique with the standard technique. Between January 1995 and December 1997, 117 patients underwent 118 HTs; 71 patients (15 women and 56 men) had 72 HTs by standard technique and 46 patients (9 women, 37 men) underwent HT using bicaval procedures. Preoperative parameters were similar in both groups; 5 patients who underwent the standard technique and no patients who underwent bicaval procedures required permanent pacemakers (p = NS). Isoproterenol infusion was significantly longer in the standard technique. Major perioperative arrhythmias (ventricular tachycardia and fibrillation, asystole) appeared in 8.2% and 7.0% of standard and bicaval HTs, respectively; atrial fibrillation appeared in 13.1% and 4.6%, respectively (p = NS). At 1 month, mitral and tricuspid regurgitation rates were higher in the standard group (p = NS); at 1 year only tricuspid regurgitation was still higher (p = NS). Right atrial pressure, Wood units, cardiac output, and cardiac index were examined (p = NS). At multivariate analysis, interaction between preoperative Wood units and transplant type was elicited for Wood units at 1 month and for right atrial pressure at 1, 3, and 6 months. In the high resistance subgroup, the patients who underwent bicaval procedures had higher resistances at 1 month. In the low resistance subgroup, right atrial pressure was higher in patients who underwent standard techniques at 1, 3, and 6 months follow-up. Thus, bicaval HT was found to be safe, without surgically related complications, it provoked significantly less blood loss, and required less isoproterenol use. No significant advantages were observed in conduction disturbances and major arrhythmias or regarding the need for temporary or permanent pacemakers.

The spectrum of aortic complications after heart transplantation.

BACKGROUND The connection between the donor and the recipient aorta is a potential source of early and late complications as a result of infection, compliance mismatch, and technical and hemodynamic factors. Moreover, the abrupt change in systolic pressure after heart transplantation involves the entire thoracic aorta in the risk of aneurysm formation. The aim of this study was to analyze the types of aortic complications encountered in our heart transplantation series and to discuss etiology, diagnostic approach, and modes of treatment. METHODS Of the 442 patients having orthotopic heart transplantation and the 11 patients having heterotopic heart transplantation at our center, 9 (2%) sustained complications involving the thoracic aorta. These 9 patients were divided into four groups according to the aortic disease: acute aortic rupture (2 patients); infective pseudoaneurysm (3 patients); true aneurysm and dissection of native aorta (2 patients); and aortic dissection after heterotopic heart transplantation (2 patients). Surgical intervention was undertaken in 8. RESULTS Five (83%) of 6 patients who underwent surgical treatment for noninfective complications survived the operation, and 4 are long-term survivors. One patient who underwent a Bentall procedure 71/2 years after heterotopic heart transplantation died in the perioperative period of low-output syndrome secondary to underestimated chronic rejection of the graft. One patient with pseudoaneurysm survives without surgical treatment but died several years later of cardiac arrest due to chronic rejection. Both patients operated on for evolving infective pseudoaneurysm died in the perioperative period. CONCLUSIONS Infective pseudoaneurysms of the aortic anastomosis are associated with a significant mortality. In noninfective complications, an aggressive surgical approach offers good long-term results. The possibility of retransplantation in spite of complex surgical repair should be considered in the late follow-up after heart transplantation, due to the increasing incidence of chronic rejection.

Risk factors for early death in patients awaiting heart-lung or lung transplantation: experience at a single European center.

BACKGROUND Our purpose was to establish whether patients on the waiting list for heart-lung or lung transplantation had different survival rates according to diagnosis and to determine the specific variables responsible for early death. METHODS Between 1988 and 1996, 278 patients were placed on the waiting list for organ transplant. Diagnoses were pulmonary vascular disease in 128, parenchymal disease in 141, and retransplantation in 9 patients. Eighty patients received transplants, 100 patients died awaiting transplantation, and 98 patients are still awaiting transplantation. Univariate and multivariate analyses of risk factors for early death on the waiting list were performed. Patients still listed < or =6 months (n=24), transplanted < or =6 months (n=37), or in the retransplantation group (n=9) were excluded. Of the remaining 208 patients, 52 died < or =6 months and 156 survived >6 months. RESULTS Patients with primary pulmonary hypertension, pulmonary fibrosis, or cystic fibrosis had statistically significantly lower survival rates at 6, 12, and 24 months (31%, 36% and 26%, respectively, at 24 months) than patients with Eisenmengers syndrome and chronic obstructive pulmonary disease (76% and 71%). Patients with Eisenmengers syndrome who died < or =6 months had significantly higher systolic pulmonary artery pressure (134+/-39 vs. 108+/-25 mmHg) and pulmonary vascular resistance (1928+/-1686 vs. 1191+/-730 dyn/sec/cm(-5)) than those who survived longer. Patients with pulmonary fibrosis who died < or =6 months had significantly lower forced vital capacity (36+/-15 vs. 47+/-13% predicted), forced expiratory volume (37+/-14 vs. 48+/-14% predicted), room air PO2 (42+/-11 vs. 50+/-11 mmHg), and room air O2-saturation (78+/-10 vs. 84+/-8%) than those who survived longer. In the multivariate analysis, only the type of pathology was a significant risk factor for death after being on the waiting list < or =6 months. CONCLUSIONS Certain pathologies and variables are risk factors for early death in patients on the waiting list. This information may be used to allocate specific donor organs to patients in greater need.

Human cytomegalovirus early infection, acute rejection, and major histocompatibility class II expression in transplanted lung. Molecular, immunocytochemical, and histopathologic investigations.

The present study aimed to investigate the relationship between acute rejection and human cytomegalovirus (HCMV) infection, as well as the coexpression of HLA-DR and immediate-early (IE) viral antigens, in 143 transbronchial biopsies and bronchoalveolar lavage fluids of 32 lung transplant recipients. We investigated the occurrence of morphologically overt viral infection with conventional histopathology, the expression of IE antigens with single labeling immunohistochemistry, the coexpression of IE antigens and HLA-DR molecules with double labeling techniques, and the presence of viral IE genes with polymerase chain reaction. Histopathologic study showed overt viral infections (12.6%) in 18 of the 143 biopsies; 8 were in a context of pneumonia and 10 were localizations without surrounding inflammatory cells; immunohistochemistry showed IE viral antigen expression in 31 (21.67%); PCR detected viral IE genes in 73/143 lavage fluids and biopsies (51%). The double labeling immunohistochemical technique showed that most IE antigen-expressing, noncytopathic cells were either HLA-DR negative in areas without infiltrates, or HLA-DR positive in those areas where inflammatory infiltrates were consistent, in the absence of viral cytopathy, with acute rejection. The results indicate that, in transplanted lung, the frequency of morphologically occult HCMV infection (as detected by immunohistochemically and/or PCR) is much higher than that of morphologically overt viral infection. The occurrence of inflammatory infiltrates (consistent with acute rejection) around morphologically occult infected cells and the possible lack of inflammation around both early- and late-infected cells suggest that in biopsies with occult infection the infiltrates should be attributed to allograft reaction. This conclusion would be in keeping with the coexpression of HLA-DR and HCMV IE in infiltrate-rich biopsies that are consistent with acute rejection, as well as with the absence of HLA-DR expression in IE antigen-positive cells in infiltrate-free-areas.

Different results of cardiac transplantation in patients with ischemic and dilated cardiomyopathy.

We retrospectively analyzed 275 consecutive transplanted patients, dividing them into group A (128 patients) affected by ischemic cardiomyopathy and group B (147 patients) affected by dilated cardiomyopathy. The difference in demographic, clinical and hemodynamic preoperative and postoperative data between the groups was studied; group A patients presented at transplantation with a less compromised hemodynamic picture, requiring inotrope infusion and mechanical assistance less frequently. The influence of etiology on early postoperative complications was also analyzed: group A patients needed postoperative mechanical assistance, inotrope, infusion and prolonged mechanical ventilation more often, therefore requiring a longer stay in the intensive care unit (ICU). Hospital mortality was twice as high in group A. The older age of group A patients per se did not influence these results significantly. The long-term follow-up was then studied with particular attention to parenchymal functions, hemodynamics, coronary artery disease, metabolic and surgical complications, and survival. The complication rate was higher in group A, with more severe hypertension and higher cholesterol levels at 1 year, a higher prevalence of accelerated coronary artery disease (CAD) and a more frequent onset of insulin-dependent diabetes. Surgical and vascular complications were also more frequent. The final result was a better 5-year actuarial survival rate for group B patients. Donor and recipient ages at the time of transplant did not influence this result. We conclude that ischemic patients, even if they are transplanted in better condition and operated more electively, have a more critical early and long-term postoperative course and a worse survival rate. These findings are not explained by advanced age, but could be due to the impact of atherosclerosis and metabolic impairments associated with ischemic disease.

Pulmonary valve lipoma presenting as syncope

We report a case of a pulmonary valve lipoma presenting as syncope in a 28-year-old woman. Surgical excision of the mass was performed in urgency and the patient was discharged uneventfully.

Successful treatment of aortic dissection after heterotopic heart transplantation

Heterotopic heart transplantation is a valid option when there is a large donor-recipient size mismatch. However, the presence of the diseased native heart can jeopardize the medium-term and long-term outcome. The problems stemming from this most commonly described in the literature are thromboembolism, angina, and arrhythmias. In this report, we describe the case of a type A aortic dissection in the native aorta that occurred 30 months after heterotopic heart transplantation and the surgical technique successfully applied for its repair. We also discuss some of the alternative techniques.

Emergency and elective cardiac retransplantation

Among 265 patients transplanted at our Institution, 7 underwent cardiac retransplantation. There were five emergency retransplantations, the indication being graft failure in one case and acute rejection in four cases. Two patients, retransplanted because of acute rejection, had a positive panel reactivity antibody and a negative donor crossmatch. In the rejection cases immunosuppression was enhanced by perioperative plasmapheresis and a postoperative 1-month course of cyclophosphamide. In two cases emergency retransplantations were successfully performed despite a highly positive prospective crossmatch. Two patients underwent elective retransplantations for chronic rejection 12 and 41 months, respectively, after the primary transplants. The overall early and late survival rates are 71% and 57%, respectively, with a mean follow-up of 48.5 months. The early and late mortality for elective retransplantation is zero. Our experience confirms both the high operative risk for emergency retransplantation and the excellent results for elective retransplantation. The use of plasmapheresis and cyclophosphamide allowed us to undertake retransplantation successfully in 2 cases with positive donor crossmatch. Both hyperimmunized patients in our series were retransplanted because of irreversible acute rejection despite a negative crossmatch with the primary donor. The meaning of negative crossmatch in patients with preformed cytotoxic antibodies is therefore questionable.

Minimally Invasive Thoracoscopic Technique for LV Lead Implantation in CRT Patients

Background: Epicardial placement of the left ventricular (LV) lead is an alternative approach to the standard cardiac resynchronization therapy (CRT) procedure. In our center we developed a minimally invasive thoracoscopic technique. We reviewed our experience to evaluate the long-term safety and effectiveness of the technique. Methods: The procedure is performed under general anesthesia with oro-tracheal intubation and right-sided ventilation, and requires 3 thoracoscopic ports (two 5-mm and one 15-mm). We analyzed 94 consecutive patients referred to our center for epicardial LV lead implantation. Results: Five patients were excluded because of concomitant conditions precluding surgery or lack of indication for CRT. The remaining 89 patients underwent the procedure. Of these, 57 had undergone previous unsuccessful LV lead implantation (Group 1). In the remaining 32 patients, effective CRT was discontinued owing to LV lead dislodgment (Group 2). LV lead implantation was successful in all patients (median pacing threshold 0.8V, IQR: 0.6-1.2, at 0.5 ms, no phrenic nerve stimulation) and CRT was successfully established in all but one patient. No complications were reported, except for 2 cases of transitory peri-electrode bleeding and 3 cases of ventricular fibrillation induced during the procedure (no sequelae). The median procedure time was 75 min (IQR: 55-95). During a median follow-up of 24 [IQR: 13-39] months, 21 patients died and 4 additional device-related complications were reported (comparable rates between groups). Conclusions: Our thoracoscopic approach proved to be safe and effective. It is a viable alternative to the standard transvenous approach in the case of failed de novo implantation and in those patients who positively respond to CRT but experience LV lead dislodgment.

A spectral approach for the quantitative description of cardiac collagen network from nonlinear optical imaging.

The assessment of collagen structure in cardiac pathology, such as atrial fibrillation (AF), is essential for a complete understanding of the disease. This paper introduces a novel methodology for the quantitative description of collagen network properties, based on the combination of nonlinear optical microscopy with a spectral approach of image processing and analysis. Second-harmonic generation (SHG) microscopy was applied to atrial tissue samples from cardiac surgery patients, providing label-free, selective visualization of the collagen structure. The spectral analysis framework, based on 2D-FFT, was applied to the SHG images, yielding a multiparametric description of collagen fiber orientation (angle and anisotropy indexes) and texture scale (dominant wavelength and peak dispersion indexes). The proof-of-concept application of the methodology showed the capability of our approach to detect and quantify differences in the structural properties of the collagen network in AF versus sinus rhythm patients. These results suggest the potential of our approach in the assessment of collagen properties in cardiac pathologies related to a fibrotic structural component.