Biomedical subjects

Lawrence S C Czer

Publications and source records attributed to Lawrence S C Czer.

9 recordsLinked to original sources

PubMed2005

Total circulatory arrest for the replacement of the descending and thoracoabdominal aorta.

HYPOTHESIS: Hypothermic total circulatory arrest (TCA) in the resection and replacement of the thoracoabdominal and descending thoracic aorta is safe, will significantly decrease the incidence of postoperative renal failure, and should be preferentially performed over left heart bypass (LHB). DESIGN: Retrospective review case series. SETTING: Large, private, urban teaching hospital. PATIENTS: All adult patients with aortic disease that involved the distal aortic arch, the descending thoracic aorta, or the thoracoabdominal aorta who underwent resection and graft replacement of the diseased segment via LHB or TCA at our institution from 1989 to 2001 are included in this study. A total of 59 patients were evaluated: 10 had descending thoracic aneurysms, 20 had thoracoabdominal aneurysms, 22 had chronic type B dissections, 4 had acute type B dissections, and 3 had adult coarctations. INTERVENTIONS: In 1989 to 1994, LHB was primarily used; in 1994 to 2001, TCA was primarily used. MAIN OUTCOME MEASURES: Renal failure, 30-day operative mortality, paraplegia, and any other morbidities. RESULTS: A significant decrease occurred in the incidence of postoperative renal failure from 15% (3/20) in patients who underwent LHB to 0% (0/39) in patients who underwent TCA (P = .04). Furthermore, a significant decrease occurred in the 30-day operative mortality, which decreased from 20% (4/20) in patients who underwent LHB to 5% (2/39) in patients who underwent TCA (P = .04). Postoperative paraplegia decreased from 5% (1/20) in patients who underwent LHB to 2.6% (1/39) in patients who underwent TCA (P > .99). CONCLUSIONS: Our use of TCA in the resection and replacement of the diseased thoracoabdominal and descending thoracic aorta has produced excellent results. Our patients have experienced no postoperative renal failure and a low 30-day operative mortality. The use of TCA in this patient population is a viable option for surgeons comfortable with the technique.

Adult↗

PubMed2005

Ischemic mitral regurgitation: revascularization alone versus revascularization and mitral valve repair.

BACKGROUND: In this study we compared the surgical management of ischemic mitral regurgitation (IMR) by revascularization alone and by revascularization combined with mitral valve repair. METHODS: We studied 355 patients who underwent revascularization alone (n = 168) or revascularization combined with mitral valve repair (n = 187) for IMR from March 1994 to September 2003. Preoperative and operative characteristics, postoperative mitral regurgitation severity, operative mortality, and late survival were examined for each surgical group. RESULTS: No differences were noted between the two groups in age, sex, history of diabetes or hypertension, and number of bypass grafts. The combined surgical group had a lower preoperative left ventricular ejection fraction (0.38 +/- 0.14 versus 0.44 +/- 0.15), greater severity of IMR, higher frequency of prior myocardial infarction, and longer cross-clamp and pump times (p < 0.01). The combined surgical group had a greater reduction in IMR grade (2.7 +/- 0.1 grades versus 0.2 +/- 0.1 grade), a lower postoperative IMR grade (0.9 +/- 0.1 versus 2.3 +/- 0.1), and a higher success with reduction of IMR by two or more grades (89% versus 11%) (p < 0.001). In patients with 3+ or 4+ IMR, both groups had similar operative mortality (11.0% in the combined group compared with 4.7% for revascularization alone, p = 0.11) and actuarial survival at 5 years (44% +/- 5% versus 41% +/- 7%, p = 0.53). Independently predictive of higher early mortality (< or = 30 days) by Cox analysis were longer pump time (p < 0.001) and older age (p < 0.02). Predictive of late mortality (> 30 days) were older age (p < 0.001), fewer bypass grafts (p < 0.01), and lower ejection fraction (p < 0.01). After adjustment for these variables, there was a trend (p = 0.08) toward a higher late survival with the combined surgical procedure. CONCLUSIONS: In patients with IMR, combined mitral valve repair and revascularization resulted in less postoperative mitral regurgitation and similar 5-year survival when compared with revascularization alone. Attempts to reduce pump time by using off-pump techniques may reduce early mortality in these high-risk patients.

Aged↗

PubMed2004

A novel sub-population of bone marrow-derived myocardial stem cells: potential autologous cell therapy in myocardial infarction.

BACKGROUND: Several studies have identified beta2-microglobulin-negative (beta2M(-)) cells as a potential stem cell fraction in the bone marrow of rats and humans. We studied the ability of bone marrow-derived beta2M(-) cells to differentiate into cardiomyocytes and reconstitute the myocardium in a model of myocardial infarction. METHODS: beta2M(-) cells were purified from bone marrow of Lewis rats using a magnetic activated cell-sorting technique. beta2M(-) cells, 2.5 x 10(6) cells in 100 microl of phosphate-buffered saline (PBS), were transplanted 7 days after infarction into a transmural myocardial scar induced by cryoinjury in Lewis rats (n = 9). Control Group 1(n = 10) received a 100-microl injection of PBS, and Control Group 2 (n = 15) received no injection. The beta2M(-) cells were labeled before transplantation, using the membrane fluorescent intercalated dye, PKH26. Repopulation was examined at 6 and 8 weeks after transplantation. Differentiation of beta2M(-) cells into cardiac myocytes was determined by the colocalization of troponin and PKH26 to the same cell, utilizing immunohistochemistry, ultraviolet photomicroscopy and fluorescence microscopy on 6-microm serial sections. Area of engraftment within the scar was calculated by planimetry. RESULTS: The treatment group had multiple islands of de novo-formed myocardium within the fibrous matrix of the transmural scar (mean area 35 +/- 4.2% of scar area at 6 and 8 weeks). These cells colocalized cardiac-specific troponin and PKH26. Using these techniques, no myocardial islands were seen in the control groups. Before transplantation, beta2M(-) cells were troponin-negative. CONCLUSIONS: This study demonstrates that beta2M(-) cells represent a novel sub-population of bone marrow-derived stem cells capable of successful and substantial engraftment in areas of transmural myocardial scar, with de novo formation of cardiac myocytes. The functional significance of this observation is being studied.

Animals↗

PubMed2004

Eosinophilic myocarditis in patients awaiting heart transplantation.

OBJECTIVE: To determine the possible causative agents of eosinophilic or hypersensitivity myocarditis in patients awaiting heart transplantation. DESIGN: Consecutive patient series. SETTING: Large university-affiliated hospital. PATIENTS: A total of 190 consecutive patients who had heart transplantation at our center. INTERVENTIONS: The myocardium of the explanted heart was examined for a mixed inflammatory cell infiltrate containing an identifiable component of eosinophils. The relative quantity of each cell type was evaluated by a semiquantitative grading system (scored 0 to 3). The clinical findings and medications were reviewed, and patients were followed after heart transplantation. MEASUREMENTS AND MAIN RESULTS: Eosinophilic myocarditis (EM) was found in the explanted heart in 14 patients (7.4%). Myocardial infiltration by eosinophils ranged from mild (n = 6), often focal involvement to marked (n = 8), usually multifocal or widespread involvement. Twelve patients (86%) had peripheral blood eosinophilia before transplant, and in ten (71%), the eosinophil count at least doubled. Loop or thiazide diuretics were used in all 14 patients, and angiotensin-converting enzyme inhibitors were used in 12. Preoperative characteristics were similar in patients with and without EM, except for a higher frequency of inotropic support and assist devices in EM patients. Dobutamine was used in 12 (86%) and dopamine in seven (50%; one with dopamine alone), and one patient (7%) received neither dopamine nor dobutamine. In two patients receiving dobutamine and one receiving dopamine, tapering or discontinuation of the inotropic infusion resulted in a significant diminution of the peripheral eosinophilia and the EM before transplantation. Postoperative survival in patients with and without EM was similar at 8 yrs (50% +/- 13% and 54% +/- 4%, p =.34). No patient in this study has had EM on biopsy after transplant. CONCLUSIONS: EM is a complication of multiple drug therapy in patients awaiting heart transplantation, and should be suspected when peripheral blood eosinophilia is present or the eosinophil count increases by at least two-fold. EM may be related to intravenous inotropic therapy, and this is the first study to document improvement in myocardial pathology after inotropic drug withdrawal. Hypersensitivity to thiazide and loop diuretics, angiotensin-converting enzyme inhibitors, and antibiotics must also be considered. Survival after heart transplantation is not impaired, and postoperative steroid therapy may prevent EM.

Angiotensin-Converting Enzyme Inhibitors↗

PubMed2004

Making an impossible mission possible.

Cardiovascular disease (CVD) is widespread in developing countries. Hypertension is a major contributor of CVD. Left ventricular hypertrophy (LVH) is a risk marker in hypertensive populations. Identification of LVH and treatment of high-risk patients can result in more effective use of the limited resources. LVH is diagnosed by echocardiography, often unavailable in developing countries. In Gambia, we used a hand-carried ultrasound (HCU) to examine 1,997 people. Seventeen percent had hypertension; of these, LVH was found in 65%. The battery-powered HCU permits clinicians to detect LVH in areas with limited access to diagnostic equipment, allowing identification of a high-risk hypertensive population.

Adolescent↗

PubMed2004

Inhibition of graft coronary arteriosclerosis after heart transplantation.

Graft coronary arteriosclerosis (GCA) is the leading cause of long-term mortality after heart transplantation (HTx). The goal of this study was to demonstrate that inhibition of immunemediated injury by cyclosporine (CsA) protects the allograft from GCA. ACI-to-Lewis rat allografts were disparate in major and nonmajor histocompatibility loci. Isografts (Lewis-Lewis) were controls. Treatment groups received either olive oil or CsA at 2.5, 5, 10, or 20 mg/kg/day for 3 months. Histology (elastin) and immunohistochemistry using monoclonal antibodies to CD4, CD8, CD45R, RT1B, CD11b/c, CD25, and alpha-actin was performed to examine the epicardial and intramyocardial coronary arteries. Computerized image morphometry was utilized to measure intimal and medial thickness and area. Rats receiving olive oil or CsA at 2.5 mg/kg/day had severe rejection and no graft survival. CsA at 5 mg/kg/day resulted in less severe rejection with significant intimal and medial proliferation (P < 0.001). CsA at 10-20 mg/kg/day paralleled Lewis-Lewis isograft outcomes and inhibited arteriosclerotic vascular changes in the allograft (P < 0.001). Perivascular T-helper cells and macrophages were a characteristic finding with low-dose CsA but rare with higher CsA doses. In this new model of accelerated GCA in rats, immune-mediated antigen-dependent vasculopathy as a result of inadequate immunosuppresion is fundamental in the development of GCA, which appeared equally in epicardial arteries and intramyocardial arterioles. CsA prevents GCA in a dose-dependent fashion in the rat allograft.

Animals↗

PubMed2004

Hemodynamics during humoral rejection events with total versus standard orthotopic heart transplantation.

PURPOSE: We hypothesized that total orthotopic heart transplantation (TOHT) improves humoral rejection hemodynamics compared with biatrial transplantation or standard orthotopic heart transplantation (SOHT). METHODS: We reviewed 1942 biopsies from 134 patients (pts) and right heart catheterization data obtained at endomyocardial biopsy. Biopsies that displayed humoral rejection by histological findings and positive immunofluorescence for immunoglobulins and complement were analyzed. Patients with pacemakers, atrial fibrillation or beta-blocker therapy at the time of biopsy were excluded. Thirty-two pts after TOHT and 22 after SOHT matching these criteria were identified. RESULTS: Demographic data, underlying disease, pretransplant hemodynamics, and donor demographics were similar. Cardiac output and index were higher in the total orthotopic group (5.9+/-1.1 vs 5.1+/-1.4 L/min, p=0.027; 3.3+/-0.5 vs 2.8+/-0.6 L/min/m2, p=0.016). Right atrial and pulmonary capillary wedge pressure were lower after TOHT (7+/-3 vs 11+/-5 mmHg, p<0.001; 13+/-4 vs 16+/-5 mmHg, p=0.035). Pulmonary pressures, pulmonary vascular resistance and heart rate were similar. CONCLUSION: TOHT offers improved hemodynamics during humoral rejection as evidenced by higher cardiac output and index with lower right atrial and pulmonary capillary wedge pressures. Future studies must examine the potential benefits of TOHT during combined cellular and humoral rejection events.

Anastomosis, Surgical↗

PubMed2002

Heart transplantation with donors fifty years of age and older.

OBJECTIVE: Limited availability of donor organs has led to the progressive expansion of the criteria for donor selection, particularly a higher age limit of potential donors. We retrospectively reviewed the outcomes of patients who underwent heart transplantation using cardiac allografts 50 years of age and older and compared them with patients who had donor organs younger than 50 years. METHOD: Between September 1989 and May 2000, 20 patients underwent orthotopic heart transplantation using donor hearts 50 years of age and older (range 50-56 years, mean 52.7 +/- 1.8 years) and were compared with 267 patients who received donor organs less than 50 years of age (range 9-49.9 years, mean 27.2 +/- 8.6 years). Patient and donor criteria were identical in both groups. Follow-up was 4 to 128 months with a mean of 37.4 +/- 2.8 months in the older donor group and 52.6 +/- 2.4 months in the younger donor group. RESULTS: There were no differences between these 2 cohorts of patients regarding age, sex, cardiomyopathy, preoperative cytomegalovirus status, New York Heart Association class, and transplant status at transplantation. Donor characteristics, including sex, left ventricular ejection fraction, diabetes, cytomegalovirus status, and allograft ischemic times, were also similar in the 2 groups. Donor/recipient cytomegalovirus matching showed no differences as well. Thirty-day or to discharge operative mortality was similar in the older and younger donor groups (5% +/- 4.8% vs 3.5% +/- 1.1%; P =.84). Actuarial survival at 1 and 5 years was also similar in both groups (89.7% +/- 6.9% vs 91% +/- 1.8% and 53.1% +/- 14.7% vs 71.0% +/- 3.1%, respectively; P =.59). No patient in the older donor group required coronary artery bypass grafting or retransplantation during the follow-up period, whereas 2 patients in the younger donor group required coronary artery bypass, and 5 patients underwent retransplantation (P > or =.50). Two patients in the older donor group died of nonspecific allograft failure, whereas 3 patients in the younger donor group experienced similar posttransplant complication (P > or =.50). CONCLUSIONS: Carefully selected donor hearts 50 years of age and older can be used for heart transplantation with long-term survival and related outcomes similar to those of younger donor organs. This use of selective cardiac allografts maximizes donor organ usage and expands the donor pool effectively without an adverse impact on long-term results.

Adolescent↗

PubMedDate not supplied

Biventricular support in patients with profound cardiogenic shock: a single center experience.

Options for managing heart failure patients with cardiogenic shock refractory to inotropic and intra-aortic balloon pump (IABP) therapy are limited. Ventricular assist devices (VADs) can bridge these patients to heart transplantation. However, controversy exists over whether extracorporeal membrane oxygenation (ECMO) before VAD placement is beneficial. We report our use of biventricular assist devices (BiVADs) as a direct bridge to transplant. Since July 1999, 19 Thoratec BiVADs were implanted for heart failure unresponsive to medical therapy. Patient ages ranged from 20 to 67 years. Causes of heart failure included idiopathic 32%, ischemic 26%, postcardiotomy 21%, and other 21%. All patients were in cardiogenic shock, and three were receiving cardiopulmonary resuscitation (CPR) before implant. Preimplant conditions included IABP 89%, mechanical ventilation 68%, three or more inotropes 84%, hyperbilirubinemia 59%, acute renal failure 63%, and hemodialysis 16%. Fifty-nine percent of patients bridged successfully to transplantation, with 90% posttransplant survival. Duration of BiVAD support ranged from 0 to 91 days, with two patients currently on support awaiting transplantation. Complications included bleeding requiring reoperation 26%, stroke 11%, infection (any positive culture) 68%, and cannula site infection 5%. The Thoratec BiVAD can successfully be used as a direct bridge to transplantation in heart failure patients with cardiogenic shock.

Adult↗