Liver transplantation in a patient with pulmonary hypertension.
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Biomedical subjects
Publications and source records attributed to W J Ko.
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Central venous catheterization represents a significant medical advancement, particularly in the treatment of critical ill. However, there is a high risk of central venous catheters-related infection. A novel antiseptic central venous catheter, made of polyurethane and impregnated with chlorhexidine and silver sulfadiazine, was developed to reduce the risk of catheters-related infection. In this study, we did a randomized clinical study to determine the efficacy by using antiseptic catheters for the prevention of central venous catheters-related infection in the intensive care units. A total of 204 patients with 235 central venous catheters were studied at the surgical intensive care units at National Taiwan University Hospital between November 1998 and June 1999. Participants received either a standard triple-lumen polyurethane catheter or an antiseptic catheter (Arrow International, Reading, Pennsylvania, USA). Both were indistinguishable from each other. Compared to standard polyurethane catheters, antiseptic catheters were less likely to be colonized by microorganisms when they were cultured at the removal (8.0 versus 20.0 colonized catheters per 100 catheters; relative risk 0.34 [95% CI, 0.15 to 0.74]; p<0.01). There was no significant differences between both groups in catheter-related infections (0.9 versus 4.9 infections per 100 catheters; relative risk 0.17 [95% CI, 0.03 to 1.15]; p = 0.07). Gram-positive cocci and fungi were more likely to colonize in the standard polyurethane catheters (p = 0.06 and 0.04, compared to antiseptic catheters respectively). Two of our cases in the control group died directly due to catheter-related candidemia. No adverse reactions such as hypersensitivity or leukopenia were found in the antiseptic catheter group. Our study showed that central venous catheters with antiseptic coating were safe and had less risk of colonization of bacteria and fungi than standard catheters in the critically ill patients.
Extracorporeal membrane oxygenation plays a very important role in resuscitation when patients are approaching impending death, because it can provide adequate cardiac and pulmonary support immediately. But percutaneous tunnel creation is a critical step for set-up of extracorporeal membrane oxygenation by percutaneous Seldinger technique. A guidewire dilator forceps used in percutaneous tracheostomy was tried to create the femoral subcutaneous tunnel. We found it could make easy the advancement of the percutaneous cannula into the vessels and over-dilatation of the vessels could also be prevented by controlled jaw opening.
Both family consent and legal consent were required for organ/tissue donation from non-heart-beating donors (NHBD) in Taiwan. A district attorney had to come to the bedside to confirm the donor's asystole, confirm the family consent, and complete some legal documents before a legal consent was issued for organ donation. The resultant warm ischemic time would be unpredictably long and in fact precluded the organ donation from NHBD in Taiwan. We developed a method of using extracorporeal membrane oxygenation (ECMO) to maintain NHBD for a longer time and prevent warm ischemic injury of the donor abdominal organs. After ventilator disconnection in NHBD, phentolamine and heparin were injected and mannitol infusion was given. After the donor's asystole was confirmed by the electrocardiogram (EKG) strip recording, the ECMO support was set up through the right femoral veno-arterial route, an occlusion balloon catheter was inserted through the left femoral artery to occlude the thoracic aorta, and bilateral femoral arteries were ligated. Usually, the ECMO could begin within 10 min after the donor's asystole. The ECMO, combined with a cooler, provided cold oxygenated blood to the abdominal visceral organs, and prevented their warm ischemic injuries. Under the ECMO support (range: 45-70 min), eight renal grafts were procured from 4 NHBD. With the exception of the first two renal grafts with delayed function, all others had immediate function postoperatively and dialysis was no longer needed. In conclusion, by our ECMO technique, NHBD could be maintained for a longer time and the renal grafts had better immediate postoperative function than those reported by other methods.
A 21-year-old male patient had suffered from palpitation and exertional dyspnea since October, 1997. He was admitted to our hospital, and a series of examinations were performed. Chest computed tomography (CT) revealed marked dilatation of the ascending aorta (about 7.5 cm at the proximal portion) and aortic annulus, an intimal flap in the ascending aorta and aortic arch was also noted. Cardiac catheterization revealed the pulmonary capillary wedge pressure was 33 mmHg, pulmonary artery pressure was 47/38 mmHg with a mean of 35.4. The cardiac index was 1.01 l/min/m2. Poor left ventricular contractility was shown by a left ventricular ejection fraction (LVEF) of 13.8% and a right ventricular ejection fraction (RVEF) of 5.13% by a radionuclide angiogram (RNA) study. Under the diagnosis of dilated cardiomyopathy and dissecting aortic aneurysm of the ascending aorta and aortic arch, he was put on a waiting list for heart transplantation. On November 11, 1997 he received heart transplantation. Resection of the dissecting aneurysm of the ascending aorta and the aortic arch and replacement with a 26 mm Vascutek graft were performed first under deep hypothermia and retrograde cerebral perfusion. Then while he was rewarming up, heart implantation was performed. He was discharged 30 days after surgery and has been doing well since then. As far as we know, no literature regarding combined heart transplantation and resection of a dissecting aneurysm of the ascending aorta and aortic arch has been reported.
Acute respiratory distress syndrome (ARDS) carries a high mortality of about 60%. The results of conventional treatments for ARDS are poor. We report the use of extracorporeal membrane oxygenation (ECMO) to rescue a child with ARDS. The patient, a 7-year-old boy, underwent a Ross procedure and mitral valvuloplasty because of severe aortic and mild mitral regurgitation. ARDS due to massive transfusion and prolonged cardiopulmonary bypass developed in the early postoperative period. Hypoxemia persisted despite conventional treatments, including pressure-controlled ventilation and high-frequency ventilation. Finally, venovenous ECMO was used to rescue the patient. With ECMO support, gas exchange was well maintained with a lower ventilator setting, and ventilator-induced lung injuries were avoided. ECMO was used for 183 hours, at which point the boy was weaned without complications. His recovery was uneventful. At the latest follow-up, 6 months after the operation, he was in New York Heart Association function class I and had no complaints of lung disease. This case suggests that venovenous ECMO can be a rescue method for patients with ARDS that is refractory to conventional treatments.
Heart failure refractory to medical treatment is consuming an increasingly large proportion of health care resources. Partial left ventriculectomy has recently been used to treat patients with end-stage dilated cardiomyopathy. A 45-year-old man in end-stage heart failure had progressive exertional dyspnea for 3 years. Cardiac catheterization showed dilated cardiomyopathy with severe pulmonary hypertension and severely impaired left ventricular function. After partial left ventriculectomy, cardiac output increased from 2.11 L/min to 5.0 L/min. The left ventricular ejection fraction measured by radionuclide angiography increased from 13% preoperatively to 28% 1 month after the operation. The patient was discharged and monitored at the outpatient clinic. He had an exercise capacity of NYHA functional class II. However, he received heart transplantation 10 months after the partial left ventriculectomy because of recurrent heart failure. Partial left ventriculectomy improves heart function and may be used as a bridge to heart transplantation as an alternative to ventricular assist devices.
We describe three successful cases of HeartMate left ventricular assist device (LVAD; Thermo Cardiosystems, Woburn, MA, USA) implantation in patients with end-stage heart failure for long-term circulatory support. Patient 1 was a 34-year-old woman with postpartum cardiomyopathy. Patients 2 and 3 were both males with dilated cardiomyopathy, 50 years and 21 years of age, respectively. They all presented in cardiogenic shock with decreased sensorium and anuria. Temporary mechanical support with an intra-aortic balloon pump or extracorporeal membrane oxygenation (ECMO) was needed for life support. Because bleeding and right ventricular failure often occur after HeartMate LVAD implantation, we used a Vascutek tube (Vascutek Ltd, Inchinnan, Scotland) graft to wrap inflow and outflow valve conduits and ECMO as a bridge to HeartMate LVAD implantation. Following surgery, cardiac output increased from 2.70, 2.06 and 2.53 L/min to 4.50, 5.80 and 5.00 L/min in the three patients. HeartMate LVAD can provide safe and stable long-term circulatory support without the need for anticoagulation. One of the patients remained on HeartMate for 287 days before undergoing successful heart transplantation. Patients with HeartMate LVAD are ambulatory and may be discharged while awaiting heart transplantation. Heart function may recover after long-term ventricular unloading with HeartMate LVAD.
Although ventricular remodeling after long-term unloading of the heart has been reported in patients after the use of medical therapy or left ventricular assist devices, it has rarely been reported in patients after heterotopic heart transplantation. Here, we describe a case of ventricular remodeling of the native heart after heterotopic heart transplantation. A 61-year-old man with end-stage dilated cardiomyopathy underwent heterotopic heart transplantation because of high pulmonary vascular resistance and a small donor heart. After the operation, echocardiography showed ventricular remodeling of the native heart, with decreased size and improved contractility of the left ventricle. Six months after the transplantation, acute graft failure of the donor heart occurred. However, the patient remained in good condition with the support of the improved native heart.
The authors evaluated risk factors potentially associated with the development of popliteal artery atherosclerosis in a population-based study and compared them with factors linked to carotid wall intimal-medial thickness. The Atherosclerosis Risk in Communities (ARIC) Study is a longitudinal investigation of cardiovascular disease in 15,800 individuals. The present analyses are based on the baseline popliteal and carotid ultrasonography examination in 10,002 subjects conducted in 1987-1989. After adjustment for covariates, both carotid and popliteal intimal-medial thicknesses were strongly associated with male sex and age (p < 0.01), having a graded relation with increasing quartiles of plasma total cholesterol and low density lipoprotein cholesterol and with plasma triglycerides (women only for popliteal) (p < 0.01). An inverse correlation was noted between plasma high density lipoprotein cholesterol and carotid (p < 0.01) and popliteal (women only) (p < 0.05) intimal-medial thicknesses. Cigarette use (p < 0.01), a history of diabetes mellitus (p < 0.01), alcohol use, elevated systolic pressures (p < 0.01), and fibrinogen levels (p < 0.01) were directly associated with both popliteal and carotid intimal-medial thicknesses. Although menopause was associated with thickened carotid (p < 0.01) and popliteal (p < 0.05) intimal-medial thicknesses, hormone replacement therapy was associated with thinner carotid walls only (p < 0.05). Although there were some differences, many of the classical risk factors associated with cardiovascular disease were also related to early thickening of both the popliteal and the carotid artery walls.
BACKGROUND: Acute myocarditis (AM) complicated with refractory cardiogenic shock carries a very high mortality. We report our experience in treating these patients, who were rescued by extracorporeal membrane oxygenation (ECMO) and intravenous immunoglobulin. METHODS: Over a 5-year period, 5 patients with AM were rescued with ECMO in our hospital. Femoral venoarterial ECMO was performed in 4 patients, and right atrium-left atrium-aorta ECMO in the other 1 due to ventricular dysfunction. Hemofiltration was applied to 3 patients. Marked elevated creatine kinase, its MB form, and troponin T (TnT) were found before ECMO. RESULTS: All the patients could be weaned off the ECMO after 140.0+/-57.7 hours of ECMO support. One patient died of multiple organ failure 10 days later after removal of ECMO, resulting in a 20% mortality. Renal function returned to normal in all survivors. The 4 survivors were discharged uneventfully in 23.3+/-8.3 days and resumed functional class I status. The TnT level declined to the low level within 3 days (slope -4.94+/-1.18 ng/mL/day), and might be an indicator of good recovery of myocardium. CONCLUSIONS: ECMO can provide an effective and simple treatment for critical AM with a satisfactory result and reduce the possibility of progressive cardiomyopathy.
OBJECTIVES: This study sought to assess the incidence of transplant coronary artery disease (CAD) in Chinese heart recipients. BACKGROUND: The prevalence of transplant CAD detected by angiography at 1, 2 and 4 years after heart transplantation was 11%, 22% and 45%, respectively. The incidence of transplant CAD in Chinese heart recipients has not been reported. METHODS: For those recipients surviving for more than 1 year after transplantation, coronary angiography was performed annually for surveillance of transplant CAD. The recipient characteristics, donor characteristics, rejection episodes, medication and human leukocyte antigen (HLA) mismatches were recorded. RESULTS: Fifty patients were included in this study. Thirteen (26%) recipients had ischemic heart disease. Two patients (4%) had active cytomegalovirus (CMV) infection after transplantation. The mean number of rejection episodes in the 1st year after transplantation was 1.15. Among 47 patients with complete data of donor and recipient histocompatibility antigens, there were seven patients (14.9%) with two or fewer HLA mismatches. Among 74 angiograms of 50 patients reviewed, only one patient had discrete stenosis less than 50% in the middle portion of the left anterior descending artery at 1 year after transplantation. The cumulative incidence of transplant CAD was 2% at 1 year and 2% at 2 and 4 years after transplantation. CONCLUSIONS: The incidence of transplant CAD was low in Chinese heart transplant recipients. Low percentage of ischemic heart disease in recipients, low occurrence of active CMV infection and rejection episodes after transplantation, less racial disparity, and lower HLA mismatches may be the important factors.
Primary rat hepatocytes can self-assemble to form multicellular spheroids when plated onto Primaria petri dishes or suspended in stirred vessels. These spheroids exhibit prolonged viability, enhanced liver-specific functions and differentiated ultrastructure compared to monolayer cultures. Upon transfer to collagen coated surface, or upon the addition of fetal bovine serum (FBS) to the culture, these spheroids began to disassemble and spread on the surface. The dynamics of cytochrome P450 CYP1A1/2 activity in the course of spheroid disassembly was examined in situ by detection of the fluorescent product, resorufin, of ethoxyresorufin O-dealkylation. Optical sectioning of the disassembling spheroids by confocal microscopy demonstrated that hepatocytes that reverted to monolayer exhibited markedly lower CYP1A1/2 activity than those that remained in a multilayered structure. This occurred whether the disassembly was caused by incubation with FBS-containing medium or by cultivation on a collagen-coated surface. When spheroids were cultured on the surface of agar, the disassembly process was retarded even in the presence of FBS. However, even in those intact spheroids, the exposure to FBS markedly decreased CYP1A1/2 activity. The decreased CYP1A1/2 activity was correlated to a diminished smooth endoplasmic reticulum as seen in the transmission electron micrograph. The results clearly demonstrate that the disassembly of hepatocyte spheroids led to decreased CYP1A1/2 activity. Furthermore, FBS contained a factor that caused CYP1A1/2 to decrease even in intact spheroids.