Analysis of Minimally Invasive Left Thoracotomy HVAD Implantation - A Single-Center Experience.

BACKGROUND: Minimally invasive left ventricular assist device (LVAD) implantation may reduce peri-/postoperative complications and risks associated with resternotomies. In this study, we describe our first results using a minimally invasive LVAD implantation technique (lateral thoracotomy [LT] group). These results were compared with LVAD implantations done via full median sternotomy (STX group). METHODS: HVAD (HeartWare, Framingham, Massachusetts, United States) implantations in 70 patients (LT group n = 22, 52 ± 15 years old; STX group n = 48, 59 ± 11 years old) were retrospectively analyzed. Minimally invasive access via left thoracotomy was feasible in 22 patients. Peri- and postoperative analyses of survival and adverse events were performed. RESULTS: No survival differences were observed between the LT and STX group (p = 0.43). LT patients without temporary right ventricular assist device (tRVAD) showed a significantly better survival rate compared to LT patients with concomitant tRVAD implantation (p = 0.02), which could not be demonstrated in the STX group (p = 0.11). Two LT and four STX patients were successfully bridged to heart transplantation and three STX patients were successfully weaned with subsequent LVAD explantations. LVAD-related infections (n = 4 LT group vs n = 20 STX group, p = 0.04) were less likely in the LT group. No wound dehiscence occurred in the LT group, whereas five were observed in the STX group (p = 0.17). The amount of perioperative blood transfusions (within the first 7 postoperative days) did not differ in both study groups (p = 0.48). CONCLUSION: The minimally invasive approach is a viable alternative with the possibility to reduce complications and should be particularly considered for bridge-to-transplant patients.

Introduction of the lung allocation score in Germany.

The aim of this study was to assess performance of the new lung allocation system in Germany based on lung allocation score (LAS). Retrospective analysis of waitlist (WL) outflow, lung transplantation (LTx) activity and 3-month outcomes comparing 1-year pre- and post-LAS introduction on December 10, 2011 was performed. Following LAS introduction, WL registrations remained constant, while WL mortality fell by 23% (p = 0.04). Reductions in WL mortality occurred in patients with cystic fibrosis (CF; -52%), emphysema (chronic obstructive pulmonary disease [COPD]; -49%) and pulmonary hypertension (PH; -67%), but not idiopathic pulmonary fibrosis (IPF; +48%). LTx activity increased by 9% (p = 0.146). Compared to pre-LAS, more patients with IPF (32% vs. 29%) and CF (20% vs. 18%) underwent transplantation and comparatively fewer with COPD (30% vs. 39%). Median LAS among transplant recipients was highest in PH (53) and IPF (49) and lowest in COPD (34). Transplantation under invasive respiratory support increased to 13% (in CF 28%, +85%, p = 0.017). Three-month survival remained unchanged (pre: 96.1% and post: 94.9%, p = 0.94). Following LAS implementation in Germany, reductions in waiting list size and WL mortality were observed. Composition of transplant recipients changed, with fewer COPD and more IPF recipients. Transplantation under invasive respiratory support increased. Reductions in WL mortality were most pronounced among CF and PH patients.

Granulocyte colony-stimulating factor therapy is associated with a reduced incidence of acute rejection episodes or allograft vasculopathy in heart transplant recipients.

BACKGROUND: We evaluated the potential effects of granulocyte colony-simulating factor (G- CSF) on the incidence of rejection and allograft vasculopathy in heart transplant recipients. METHODS: Of 247 patients undergoing heart transplantation from 2000 to 2007, 52 (21%) developed leukopenia (white blood cell [WBC] <2.5 × 10(9) cells/L) in the absence of active infection, rejection, or malignancy. In 24 (46%) patients a clinical decision was made to treat the leukopenia with G-CSF (G-CSF group), and 28 (54%) Patients received no G-CSF (non-GCSF group). Patients followed up for 1 year after the period of leukopenia were assessed for allograft vasculopathy and acute rejection incidence. RESULTS: At baseline, the G-CSF group and the non-GCSF group did not differ in age, gender, race, heart failure etiology, creatinine, left ventricular ejection fraction (LVEF) or immunosupressive regimen. During 1-year follow-up there were no deaths in the G-CSF group, and 1 death in the non-GCSF group (P = .34). The incidence of rejection or progressive allograft vasculopathy was lower in the G-CSF group when compared with the non-GCSF group (2 [8%] vs 15 [53%]; P < .01). Multivariate analysis identified both prior rejection episodes and G-CSF therapy as factors associated with the combined end-point of rejection or progressive allograft vasculopathy (odds ratio [OR] = 7.89 [1.67-37.2] and OR = 0.09 [0.02-0.52], respectively). CONCLUSIONS: G-CSF therapy appears to be associated with a decreased incidence of acute rejection episodes or allograft vasculopathy in heart transplant recipients, suggesting a potential immunomodulatory effect of G-CSF.

ST-elevation myocardial infarction following heart transplantation as an unusual presentation of coronary allograft vasculopathy: a case report.

BACKGROUND: The presentation, mechanisms, and incidence of ST elevation myocardial infarction (STEMI) in heart transplant recipients have been characterized only to a limited degree in the current literature. Herein, we present a unique case of STEMI years after heart transplantation with a focus on the salient features of its diagnosis and interventions. We also provide a review of the epidemiology of this phenomenon. CASE REPORT: A 33-year-old woman who was status post cardiac transplantation for dilated cardiomyopathy presented to the clinic with mild nonspecific fatigue and concern after having noticed relative bradycardia compared with her posttransplantation baseline heart rate. Electrocardiogram (ECG) showed junctional rhythm and inferior ST elevations, likely reflecting nodal ischemia. Troponins were grossly positive and echocardiogram showed marked right ventricular dysfunction. RESULTS: Successful percutaneous coronary intervention (PCI) with aspiration thrombectomy and drug-eluting stent placement was emergently performed. The heart's rhythm soon returned to sinus tachycardia. Right ventricular wall-motion abnormalities resolved. The patient suffered no clinical sequelae of her STEMI. CONCLUSION: This case illustrated that "classic" symptoms of STEMI may not occur at all in the setting of heart transplantation. To our knowledge, this is the first case of posttransplantation STEMI presenting as asymptomatic bradycardia, and highlights the importance of maintaining high clinical suspicion for ischemia in transplant recipients with subtle changes. In reviewing the epidemiology of this case, we locate and bundle different types of studies that have directly or indirectly looked at STEMI in heart transplantation. For a variety of putative pathophysiological reasons, STEMI is indeed a rare manifestation of the common transplant phenomenon of coronary artery vasculopathy (CAV).

Severe bacterial superinfection based on influenza A (H1N1) pneumonia in a heart-lung transplant recipient.

A 47-year-old heart-lung transplant recipient presented to our outpatient transplant clinic with respiratory infection. Her nose and throat swabs for influenza A (H1N1) infection were negative. Broncheoalveolar lavage showed a positive result for H1N1 infection. Antiviral therapy was initiated. Because of superinfection with Pseudomonas aeruginosa and Aspergillus terreus, her clinical condition worsened. The clinical condition of the patient improved with antibiotic and antifungal treatment. Negative nose and throat swab results cannot rule out H1N1 infection safely. We therefore advocate to routinely perform broncheoalveolar lavage.

Minimally invasive resection of a right atrial mass in a cardiac transplant recipient: a case report.

Intracardiac thrombus formation usually occurs in the left-sided cavities of the heart, most frequently in the presence of atrial fibrillation or cardiomyopathy. We report the case of an initially unclear mass developing in the right atrium (RA) of a heart transplant recipient, which was subsequently resected via a minimally invasive surgical approach. Access via right anterior minithoracotomy using videoscopic assistance allowed for uncomplicated RA thrombectomy in the presented case, avoiding reentry sternotomy with the potential risk of cardiac injury and without aortic cross-clamping or cardioplegic arrest. The patient is doing fine with excellent graft function at the latest follow-up 4 months after minimally invasive thrombectomy and 30 months after cardiac transplantation. To the best of our knowledge, this is the first report describing minimally invasive resection of a right atrial thrombus in a heart transplant recipient.

Transcatheter aortic valve implantation in a heart transplant recipient: a case report.

Transcatheter aortic valve implantation (TAVI) has evolved into a feasible therapeutic option for the management of selected patients with severe aortic stenosis and high or prohibitive risk for standard surgery. Symptomatic severe aortic stenosis occasionally occurs in the allograft long after heart transplantation. Because of specific characteristics and comorbidities of heart transplant recipients, these patients may be considered candidates for this less invasive approach. We report a first case of successful transapical TAVI in a heart transplant recipient with symptomatic severe calcific aortic valvular disease and relevant comorbidities long after heart transplantation.

Twenty-year survivors of heart transplantation at Stanford University.

Human heart transplantation started 40 years ago. Medical records of all cardiac transplants performed at Stanford were reviewed. A total of 1446 heart transplantations have been performed between January 1968 and December 2007 with an increase of 1-year survival from 43.1% to 90.2%. Sixty patients who were transplanted between 1968 and 1987 were identified who survived at least 20 years. Twenty-year survivors had a mean age at transplant of 29.4 +/- 13.6 years. Rejection-free and infection-free 1-year survivals were 14.3% and 18.8%, respectively. At their last follow-up, 86.7% of long-term survivors were treated for hypertension, 28.3% showed chronic renal dysfunction, 6.7% required hemodialysis, 10% were status postkidney transplantation, 13.3% were treated for diabetes mellitus, 36.7% had a history of malignancy and 43.3% had evidence of allograft vasculopathy. The half-life conditional on survival to 20 years was 28.1 years. Eleven patients received a second heart transplant after 11.9 +/- 8.0 years. The most common causes of death were allograft vasculopathy (56.3%) and nonlymphoid malignancy (25.0%). Twenty-year survival was achieved in 12.5% of patients transplanted before 1988. Although still associated with considerable morbidity, long-term survival is expected to occur at much higher rates in the future due to major advances in the field over the past decade.

Effect of inhaled tacrolimus on cellular and humoral rejection to prevent posttransplant obliterative airway disease.

This study aimed to investigate the pharmacokinetics after tacrolimus aerosol inhalation and to assess its efficacy to suppress acute and chronic airway allograft rejection. Orthotopic tracheal transplantations were performed and tacrolimus (4 mg/kg) was administered orally (PO) or via aerosol (AER). Tracheal tissue level AUCs(0-12) were similar in both treatment groups, but blood AUCs(0-12) were approximately 5.5-fold lower with AER (p < 0.001). Interestingly, only PO animals showed elevated BUN, cholesterol and triglycerides on POD 60 (p < 0.05). Histology of grafts harvested after 6 and 60 days revealed that both treatment groups were similarly effective in suppressing graft mononuclear infiltration (p < 0.001). Cellular immune activation (assessed by IFN-gamma- and IL-4-ELISPOTS), however, was far more effectively suppressed by tacrolimus PO (p < 0.001). In both treatment groups, the vigorous alloreactive IgM-antibody surge was effectively inhibited (p < 0.001). Due to the insufficient systemic cellular immunosuppression, discontinuation of tacrolimus AER resulted in a far stronger (3.5-fold) graft infiltration on POD 8 compared to PO (p < 0.001). Tacrolimus aerosol reduces systemic side effects and effectively protects the airway graft from early cellular rejection and chronic obliterative airway disease.

Is the malononitrilamide FK778 better for the prevention of acute or chronic rejection?

OBJECTIVE: The aim of this study was to assess the efficacy of FK778 to prevent acute and chronic allograft rejection compared with other immunosuppressive agents. MATERIALS AND METHODS: Heterotopic Brown-Norway (BN)-to-Lewis rat cardiac transplantations and heterotopic BN-to-Lewis tracheal transplantations were performed to study acute heart rejection and the development of chronic obliterative airway disease (OAD), respectively. Recipients were treated with FK778, tacrolimus, MMF, or sirolimus for 10 days (acute rejection study) or 28 days (chronic OAD study) at varying doses. RESULTS: In untreated recipients, cardiac allograft survival was 6.2 +/- 0.4 days. FK778 (20 mg/kg), tacrolimus (2 or 8 mg/kg), mycophenolate mofetil (MMF; 40 mg/kg), or sirolimus (0.5 or 2 mg/kg) significantly prolonged graft survival to 17.0 +/- 2.8, 18.5 +/- 2.7, 25.0 +/- 2.5, 20.7 +/- 3.8, 14.5 +/- 2.2, and 23.2 +/- 1.5 days, respectively (P < .05). Tracheal grafts in untreated recipients showed intense infiltration and complete luminal obliteration by day 28. FK778 (20 mg/kg), tacrolimus (1 or 4 mg/kg), MMF (10 or 40 mg/kg), or sirolimus (0.5 or 2 mg/kg) significantly inhibited tracheal luminal obliteration (19.5% +/- 16.4%, 44.2% +/- 33.6%, 12.3% +/- 3.3%, 61.7% +/- 18.6%, 18.3% +/- 11.3%, 55.0% +/- 30.9%, and 8.5% +/- 3.5% (P < .05). All 4 high-dose groups showed similar efficacy. CONCLUSIONS: When used in therapeutic doses, tacrolimus and sirolimus were more effective than FK778 to prolong cardiac allograft survival. However, with its antiproliferative effects on smooth muscle cells, its good tolerability, and its blockade of cytomegalovirus replication, FK778 proved effective to prevent chronic OAD development. Thus, FK778 may acquire an important role in maintenance therapy for the prevention of long-term fibroproliferative complications.

Stem cell transplantation: the lung barrier.

BACKGROUND: Mesenchymal stem cells (MSCs) show differentiation capacity along mesenchymal lineages and have the potential to aid tissue regeneration. MSC transplantation strategies are therefore currently being assessed following injury to various organs. However, potential MSC migration to these organs after intravenous (IV) MSC injection continues to be impeded by cell trapping within the lung. METHODS: Mouse MSCs were isolated, purified, transfected with firefly luciferase, and labeled with CSFE. Their size was assessed in vitro. To estimate the diameter of mouse pulmonary capillaries, fluorescence-labeled microspheres of different sizes were injected with or without sodium nitroprusside (SN) pretreatment. The lungs were harvested after 30 seconds and mean numbers of trapped microspheres per high-power field (HPF) were calculated. After IV injection of MSC suspensions (with or without SN), their dynamic distribution was monitored by in vivo luciferine imaging as well as by histopathology. RESULTS: The diameter of suspended MSCs in vitro was 15 to 19 microm. Whereas nearly no 4-microm microspheres could be detected in lung sections, the numbers of trapped 10- and 15-microm microspheres could be significantly decreased by prior SN injection from 19.3 +/- 11.1 to 6.0 +/- 1.6 cells/HPF (P = .004) and from 34.9 +/- 11.9 to 25.6 +/- 8.1 cells/HPF (P = .028), respectively. Within seconds after MSC IV injection, the vast majority of cells was found in the lungs. However, cell trapping in the pulmonary microvasculature was significantly reduced by pre-treatment with SN. CONCLUSIONS: We demonstrate that cell trapping in lungs can be reduced with IV SN pretreatment, increasing MSC passage through the lung capillaries, and potentially facilitating cell access to injured organs.

Tracheal allograft transplantation in rats: the role of different immunosuppressants on preservation of respiratory epithelium.

BACKGROUND: Bronchiolitis obliterans is the most significant complication adversely affecting the survival of lung allograft recipients. Injury and loss of epithelium are associated with obliteration of the airway lumen. The aim of this study was to examine the effects of various immunosuppressants on airway epithelium. METHODS: Tracheae from Brown Norway donors were heterotopically transplanted into the greater omentum of Lewis (allografts) or Brown Norway (isografts) animals. Recipients were treated for 28 days with FK778 (20 mg/kg), tacrolimus (4 mg/kg), or sirolimus (2 mg/kg). Tracheal segments were evaluated for the degree of luminal occlusion as well as the type and percent of luminal epithelial cell coverage. RESULTS: All agents inhibited peritracheal infiltration and luminal obliteration. Tacrolimus- more than sirolimus-treated recipients showed partial preservation of the luminal epithelial coverage, whereas animals that received FK778 showed no respiratory epithelium. The epithelial loss was accompanied by the appearance of fibrous tissue, which replaced the mucosa. CONCLUSIONS: Tacrolimus as well as sirolimus effectively prevented the development of obliterative airway disease whereas tacrolimus and, to a lesser degree, sirolimus preserved epithelial cells as a source of protective cytokines. With FK778 significant airway obliteration was suppressed despite complete epithelial loss. Thus, FK778-treated animals displayed an epithelial-independent inhibitory effect on myofibroblast proliferation.

FK778: new cellular and molecular mechanisms of action.

PURPOSE: The new malononitrilamide FK778 is currently being evaluated as an immunosuppressant for organ transplantation. Its main mechanism is inhibition of a pivotal enzyme of pyrimidine biosynthesis. This report revealed new mechanisms of action on different cell types involved in acute and chronic allograft rejection. METHODS: Purified Brown-Norway rat aortic endothelial cell (EC) cultures were pretreated with several concentrations of FK778. Endothelial adhesion molecule expression (ICAM-1/VCAM-1) stimulated with TNF-alpha was quantified by immunofluorescence. Purified Lewis rat lymphocytes (LC) incubated with FK778 were stimulated via TCR/CD28 signals, and CD25 expression was quantified using FACS analysis. Uridine addition was used in all assays to reverse the pyrimidine synthesis blockade. Lymphocyte-EC interaction was assessed by micromanipulator-assisted single-cell adhesion assays. Finally, smooth muscle cell (SMC) proliferation and migration was analyzed. Uridine addition was used in all assays to reverse the pyrimidine synthesis blockade. RESULTS: TNF-alpha stimulation and TCR/CD28 co-stimulation significantly increased EC ICAM-1/VCAM-1-expression and LC CD25 surface expression, respectively. These effects were dose-dependently inhibited by FK778 and were not reversed by the addition of uridine. FK778 dose-dependently attenuated LC adhesion to allogeneic EC. The dose-dependent inhibition of SMC proliferation by FK778 was abolished by uridine addition, whereas the inhibitory effect on SMC migration was not affected by uridine supplementation. CONCLUSIONS: FK778 directly reduced endothelial adhesion molecule up-regulation, inhibited lymphocyte activation, and attenuated lymphocyte-endothelium interactions, critical early steps in graft rejection. These effects were separate from the blockade of pyrimidine synthesis. The antiproliferative potency of FK778 on SMC may be an important mechanism to inhibit the fibroproliferative lesions of chronic organ rejection.

Robotically assisted coronary artery bypass surgery with the ZEUS telemanipulator system.

Our goal of minimally invasive coronary bypass surgery is a completely endoscopic operation and anastomosis. Minimally invasive procedures reduce the invasiveness of the operation and therefore the morbidity and length of hospitalization of the patients. A possible solution to the technical problems that accompany manually performed endoscopic anastomoses is telemanipulation, which provides surgeons with the necessary equipment to accomplish totally endoscopic coronary anastomoses. Robotic telemetric systems together with 3-D visualization provide the necessary platform. This article summarizes the current worldwide experience with the ZEUS(TM) system in cardiac surgery and describes the steps from preclinical to endoscopic operation, focusing on the potential limitations of the procedure and the system.

Correlation between mononuclear infiltration and changes in VASP phosphorylation patterns after heterotopic cardiac transplantation in the rat.

Chronic cardiac transplant vasculopathy still remains the major cause of late graft failure after the 1st postoperative year, with iNOS playing a central role in the progression of this disease. Since VASP, a recently identified microfilament-associated protein in smooth muscle cells, endothelial cells, and platelets, is phosphorylated by cyclic nucleotide dependent protein kinases, changing amounts of NO-producing mononuclear infiltration cells during cardiac rejection are supposed to change platelet VASP phosphorylation patterns. We investigated whether platelet VASP Ser(157) phosphorylation (VASP shift) after coronary passage of rat cardiac allografts correlates with graft infiltration. The Lew-F344 heterotopic rat cardiac transplantation model was used. Native hearts and grafts were harvested 3-150 days after transplantation and were used for Langendorff perfusion. The platelet VASP shift after native heart and graft perfusion was identified. Additional iNOS stimulation and iNOS inhibition were achieved pharmacologically. Immunohistology revealed graft mononuclear infiltration. Platelet VASP Ser(157) and Ser(239) phosphorylation significantly increased after coronary passage of native hearts and grafts (p < 0.01). Though platelet VASP Ser(157) phosphorylation failed to directly express graft infiltration, we showed a significant correlation between changes of platelet VASP shift and extent of grafts' mononuclear infiltration after competitive iNOS inhibition (p < 0.01). The platelet VASP shift is modified during coronary perfusion, and this modification correlates with mononuclear infiltration in the graft. This emphasizes the influence of mononuclear infiltration cells on microfilamental structures of the cytoskeleton in adjacent cells.

Midterm results and quality of life after minimally invasive vs. conventional aortic valve replacement.

BACKGROUND: This study compares early and mid-term results as well as the quality of life (QOL) between the minimally invasive and conventional aortic valve replacement (AVR). METHODS: Between 7/97 and 4/01, 70 patients (mean age 64.3 +/- 1.3 years) underwent minimally invasive AVR (group M) through an L-shaped ministernotomy. The results were compared to those of 70 conventional AVR (group C) patients during the same period. Patients were equally matched according to age, sex, ejection fraction, valvular lesion, and valve prosthesis. In groups M and C, follow-up was 98.5 % and 95.4 % complete and averaged 34.0 +/- 10.3 and 33.1 +/- 12.9 months, respectively. RESULTS: There were no hospital deaths in group M but two deaths in group C (p = n. s.). Conversion to full sternotomy was necessary in two group M patients. Cross-clamping time (71 +/- 15 min vs. 58 +/- 18 min), cardiopulmonary bypass time (105 +/- 22 min vs. 84 +/- 24 min), and time of surgery (228 +/- 45 min vs. 184 +/- 48 min) were significantly longer in group M. No statistically significant differences between the two groups for postoperative ventilation time, transfusion rate, ICU stay or length of hospital stay were recorded. At the end of follow-up, 98.5 % vs. 96.9 % of the patients were free of thromboembolism (p = n. s.), 100.0 % vs. 96.9 % were free of endocarditis (p = n. s.), and 98.5 % vs. 100.0 % were free of reoperation (p = n. s.) in group M compared to group C. Survival was 97.0 % vs. 91.9 % (p = ns). No differences in any of the 8 QOL categories, in patient satisfaction with the operative result or in judgment of the cosmetic aspect were noted among groups. CONCLUSIONS: This study has failed to show any advantage of minimally invasive AVR in early or midterm follow-up.