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Biomedical subjects

T D Tjan

Publications and source records attributed to T D Tjan.

At least 19 recordsLinked to original sources
PubMed2001

Pyodera gangrenosum after aortic valve replacement.

A 68-year-old male patient developed pyoderma gangrenosum after elective aortic valve replacement. Treatment with steroids and clofazimine was initiated, which resulted in rapid cessation of the necrotic process. Due to thoracic instability, stabilization of the sternum was performed followed by surgical debridement and atraumatic wound closure. Postoperatively, immunosuppression with cyclosporine A was added; the patient recovered completely. Pyoderma gangrenosum is a potential life-threatening complication that must be considered in patients with severely impaired wound healing after cardiac operation.

Aged↗
PubMed2001

The impact of anti-endotoxin core antibodies on endotoxin and cytokine release and ventilation time after cardiac surgery.

OBJECTIVES: We hypothesized that a temporary cardiopulmonary bypass (CPB)-induced reduction of endotoxin antibody levels contributes to elevated endotoxin levels and the associated inflammatory consequences, with a significant influence on the postoperative ventilation time period. BACKGROUND: Cardiac surgery using CPB induces a systemic inflammatory response syndrome with an associated risk of increased postoperative morbidity and mortality. METHODS: A total of 100 consecutive patients undergoing elective coronary artery bypass graft surgery using CPB were prospectively investigated. Endotoxin core antibodies (immunoglobulin [Ig] M/IgG against lipid A and lipopolysaccharide), endotoxin, interleukin (IL)-1-beta, IL-6, IL-8 and tumor necrosis factor-alpha were measured serially from 24 h preoperatively until 72 h postoperatively. RESULTS: Eighty-five patients had no complications (group 1), whereas 15 patients required prolonged ventilation (group 2). In both groups, there was a decrease of all antibodies 5 min after CPB onset, compared with baseline values (p < 0.001), an increase of endotoxin and IL-8 peaking at 30 min postoperatively (p < 0.001) and an increase of IL-6 peaking 3 h postoperatively (p < 0.001). In group 2, preoperative antibody levels were lower (p < 0.01)--specifically, the decrease in IgM was significantly stronger and of longer duration (p < 0.002)--and levels of endotoxin (p < 0.001) and IL-8 (p < 0.001) were higher at 30 min postoperatively. CONCLUSIONS: We conclude that an CPB-associated temporary reduction of anti-endotoxin core antibody levels contributes to elevated endotoxin and IL-8 release. Furthermore, lower levels of IgM anti-endotoxin core antibodies were associated with a greater rise in endotoxin and IL-8, as well as prolonged respirator dependence.

Adult↗
PubMed2001

Activation of the cardiac interleukin-6 system in advanced heart failure.

OBJECTIVES: The study objective was to assess the cardiac expression of interleukin-6 (IL6) and its receptor (IL6R) in advanced heart failure. BACKGROUND: While IL6 plasma levels are elevated and associated with an impaired prognosis in advanced heart failure, little is known about the intracardiac expression of the IL6 system. METHODS: Heart tissue was obtained from 20 patients (n=10, idiopathic dilated cardiomyopathy, age 44+/-15 years; n=10, ischemic cardiomyopathy, age 55+/-8 years) at the time of transplantation. Left and right ventricular tissue was subjected to in situ hybridization, Northern blot analysis, and RT-PCR. Signals were quantified by densitometric scanning and corrected for G3PDH-mRNA levels. Right ventricular biopsy specimens (n=11) of patients with arrhythmias and normal cardiac function served as controls. In addition, data were correlated with cardiac catheterization and echocardiography data obtained at transplant evaluation. RESULTS: Ventricular IL6 and IL6R transcripts were detected in all explant specimens examined. Expression of both mRNA species was higher than in controls (P=0.001). Left ventricular IL6 mRNA levels correlated positively with heart rate (r=0.77; P=0.009), pulmonary capillary wedge pressure (r=0.53; P=0.03), right atrial pressure (r=0.77; P=0.003), and inversely with left ventricular ejection fraction (r=-0.61; P=0.03). Right ventricular IL6 mRNA levels correlated inversely with cardiac index (r=-0.48; P=0.05). IL6R expression did not correlate with hemodynamic data. CONCLUSIONS: In advanced heart failure, cardiac IL6/IL6R mRNA expression is increased and may play a role in the pathophysiology of advanced heart failure.

Adult↗
PubMed2001

Prediction of clinical outcome after cardiac surgery: the role of cytokines, endotoxin, and anti-endotoxin core antibodies.

Coronary artery bypass grafting (CABG) using cardiopulmonary bypass (CPB) can lead to a systemic inflammatory response syndrome with organ failure and increased morbidity and mortality. The mechanisms of these findings are still under discussion. We investigated whether anti-endotoxin core antibodies, endotoxin, and proinflammatory cytokines influence the clinical course after cardiac surgery. Seventy-eight patients undergoing CABG using CPB were investigated. Anti-endotoxin core antibodies, endotoxin, interleukin (IL)-6, IL-8, IL-1beta, and TNF-alpha were measured 24 h preoperatively and up to 72 h postoperatively. Patients with a postoperative mechanical ventilation time below 24 h (n = 65; Group A) were compared to patients with prolonged respirator therapy (>24 h; n = 13; Group B). Preoperative antibody levels were significantly lower in Group B (P < 0.001). In this group, antibody levels remained decreased during the observation period (P < 0.001). Endotoxin significantly increased 30' postoperatively in both groups (P < 0.002). The increase in Group B was 3-fold higher (P< 0.001). IL-8 increased postoperatively in both groups, peaking 3 h after surgery (P < 0.001). In Group B, the IL-8 release was significantly higher than in Group A (P < 0.001). IL-6 significantly increased in both groups, reaching its maximum 24 h postoperatively (P < 0.001). No differences between groups were observed. No significant changes of IL-1beta and TNF-alpha were observed. We conclude that anti-endotoxin core antibodies may be predictive of adverse outcome after cardiac surgery. The imbalance between antibodies and endotoxin results in an exaggerated increase in endotoxin and IL-8 with an impact on clinical outcome.

Aged↗
PubMed2000

Wound complications after left ventricular assist device implantation.

BACKGROUND: Wound necrosis and infection pose a tremendous risk for patients with left ventricular assist devices. METHODS: We analyzed our database of patients with left ventricular assist devices for those who developed wound dehiscence and concomitant infection after left ventricular assist device implantation. RESULTS: Three of our 66 patients (4.5%) with implantable ventricular assist devices had had severe wound complications with necrosis of the abdominal or thoracic wall uncovering part of the device. The predominant impact on the development of these complications was presumably related to multiple surgical interventions on the same site. CONCLUSIONS: Nevertheless, these patients can recover and undergo successful heart transplantation if adequately managed.

Abdominal Muscles↗
PubMed2000

Reversal of metallothionein expression is different throughout the human myocardium after prolonged left-ventricular mechanical support.

OBJECTIVES: We examined the distribution of metallothionein (MT), a stress-inducible protein, and the cardiomyocyte diameter in human hearts after left-ventricular assist device (LVAD) support. BACKGROUND: Remodeling in end-stage heart failure is characterized by myocyte hypertrophy and alterations of several inducible proteins. LVADs used as a bridge to cardiac transplantation unload the left ventricle and may lead to a reversal of the remodeling, but little is known about the pathophysiology of this process. METHODS: The immunoreactivity for MT and the cardiomyocyte diameter was analyzed in left-ventricular tissue specimens of 17 patients with end-stage heart failure before and after LVAD support. RESULTS: MT positive cells were mainly located sub-endocardially in vacuolized cardiomyocytes and in small vessels throughout the myocardium. During LVAD support, MT-positive myocytes decreased in the sub-endocardial (p < 0.008) and sub-epicardial region (p < 0.003), MT-positive vessels decreased similarly (p < 0.003). Cardiomyocyte diameter decreased significantly only in the sub-endocardium (p < 0.03). Hearts of patients supported longer than 88 days (= median) showed substantially lower MT reactivity at the time of LVAD explantation as compared to patients supported less than 88 days. CONCLUSION: Our results suggest that unloading of the left ventricle during prolonged LVAD support leads to regression of cellular hypertrophy and a decrease of MT expression. The preferential reduction of MT-positive vacuolized cardiomyocytes in the sub-endocardium is comparable with the concept of greatest reduction of wall stress in this area of the myocardium and may be due to the improvement of myocardial blood flow and the energy balance.

Adult↗
PubMed2000

The bad ventricle--revascularization versus transplantation.

BACKGROUND: The proportion of patients with left-ventricular dysfunction (LVD) undergoing high risk revascularization is increasing. In this patient group, the perioperative risk is elevated because of the pre-existing pathophysiology. Detailed evaluation and interdisciplinary differential therapeutic considerations on the basis of the comparative benefit rationale, with cardiac transplantation alternative, is mandatory. METHODS: Among 7275 patients who underwent coronary artery bypass grafting between 1990 and 1998 in our institution, we found 51 patients who had had an ejection fraction <20%, and thus were candidates for transplantation (group CABG); these were compared with 163 patients who were listed for cardiac transplantation because of ischemic cardiomyopathy (group HTX). The survival analysis was performed on the basis of the intention-to-treat principle independent of subsequent transplantation. RESULTS: Both groups were comparable with regard to left-ventricular ejection fraction; pulmonary capillary wedge pressure and serum creatinine, but patients in the CAGB group were older (63+/-11 vs 56+/-8; p = 0.001) and included a higher percentage of women (m/f: 42/9 vs 152/11; p = 0.03). Nevertheless, there was a similar 1-year survival in both groups (group BP 71.9% vs group HTX 66.3%; p = ns). Looking at the CABG group, the internal thoracic artery was used in 36/51 patients, an intra-aortic balloon pump was used preoperatively in 26 patients, and intraoperatively in 6. Left-ventricular assist devices had to be inserted in three patients, extracorporeal membrane oxygenation once. Perioperative (30 day) survival was 88.2 %. An elevated preoperative serum creatinine and the nonusage of the internal thoracic artery predicted an adverse outcome. In the long-term course, the NYHA functional class improved in most cases from III preoperatively to I after 26 (2-66) months. CONCLUSION: We conclude that patients with ischemic cardiomyopathy, viable myocardium, and graftable vessels can be revascularized with acceptable risk. Since for these patients a standby of mechanical circulatory support must be anticipated perioperatively, this infrastructure should be established within the center.

Aged↗
PubMed1999

Ambulatory care of patients with left ventricular assist devices.

BACKGROUND: Left ventricular assist devices (LVAD) have revolutionized the treatment of patients with acute and chronic heart failure as they provide a high quality of life. We report on our experience with patients receiving ambulatory care after LVAD implantation. METHODS AND RESULTS: Since July 1995, 46 patients with a mean age of 45+/-11 years underwent implantation of an electrically driven LVAD with portable controller and batteries. Sixteen (35%) patients bridged >30 days were treated in part on an outpatient basis. After LVAD implantation, they were treated in the hospital for 86+/-32 days (range 40 to 153 days). Afterward, they received ambulatory care for 74+/-76 days (range 2 to 301 days, total experience 1206 days). In 13 cases, the outpatient treatment was interrupted by 1.7+/-1.7 readmissions, for a total of 32+/-42 days (median 19 days). Reasons for readmission included systemic or drive line infections (incidence 0.0066 per outpatient day), suspected or true thromboembolic events (incidence 0.0066 per outpatient day), and suspected malfunction of the LVAD. One patient supported as alternative to transplantation died after cerebral bleeding after 244 days, 1 patient with a history of acute myocarditis had ventricular fibrillation during LVAD assist while being at home for 177 days and died in a low output state, 10 patients were given transplantation after a mean support interval of 206+/-88 days, and 4 patients currently await heart transplantation. CONCLUSIONS: Outpatient treatment after LVAD implantation is feasible, and severe complications are uncommon.

Adult↗
PubMed1999

Combining nonpharmacologic therapies for advanced heart failure: the Münster experience with the assist device-defibrillator combination.

Implantable cardioverter defibrillators (ICDs) and ventricular assist devices (VADs) have been used as a bridge to cardiac transplantation. In selected patients, the combined implantation may be required. This study was motivated by a case of a 33-year-old female patient with giant cell myocarditis who died of ventricular tachyarrhythmias after having been placed on a VAD with which she had been treated on an out-of-hospital basis for a prolonged period of time. A subsequent retrospective analysis of our data showed that, of 73 patients who had to be bridged mechanically (54 Novacor, 12 TCI Heartmate, 4 Thoratec, 3 Medos) in our institution between 1993 and 1998, 10 patients had undergone defibrillator implantation either before (n = 8) or after (n = 2) implantation of a VAD. The cases are presented, and the feasibility of the combination therapy discussed.

Adult↗
PubMed1999

Anastomosis to the wrong vessel during off-pump bypass surgery via mini-thoracotomy.

Recently, minimally invasive coronary artery bypass graft operation has been established as a new treatment strategy for cardiac surgeons. We report on a patient who underwent off-pump coronary artery bypass graft operation through a mini-thoracotomy to the wrong coronary artery (first diagonal) with consecutive successful percutaneous transluminal coronary angioplasty of the vessel involved (left anterior descending coronary artery) to demonstrate a special risk that is associated with this kind of operation.

Adult↗
PubMed1999

Minimally-invasive versus conventional aortic valve replacement--perioperative course and mid-term results.

OBJECTIVE: We performed a case-control-study to compare perioperative and mid-term results of minimally invasive with conventional aortic valve replacement. METHODS: Between 8/96 and 7/97, 113 patients underwent isolated aortic valve replacement (minimally invasive: 29, conventional: 84) in our Department. Diagnosis, ejection fraction, pressure gradient/regurgitation fraction, age, gender and body-mass-index were used as matching criteria for the case-control-study. For qualitative data correspondence was requested, for quantitative data deviations up to 10% were accepted. With these criteria 25 patients of the minimally invasive group were matched to 25 patients of conventional group. All patients were reexplored 1 year after aortic valve replacement. Statistical analysis was done by the Fisher's exact test for qualitative data and the Mann-Whitney test for quantitative data. RESULTS: We implanted 15 (20) bioprosthesis' and 10 (five) mechanical prosthesis' in the minimally invasive, respectively, conventional group. There were no statistically significant differences between both groups with respect to the perioperative course, only duration of surgery (mean 201.6 vs. 143.9 min, P < 0.01) and extracorporeal circulation (mean 116.1 vs. 71.3 min, P < 0.01) as well as aortic-cross-clamp-time (mean 77.9 vs. 46.9 min, P < 0.01) were significantly longer in the minimally invasive group. Postoperative complications occurred in one patient of the minimally invasive group (dissection of the right coronary artery) and four patients of the conventional group (third degree AV block, pneumothorax, grand mal convulsion, cardiopulmonary resuscitation). Two patients, one of each group, died during follow-up for unknown reasons. Follow-up revealed no significant differences with respect to clinical and echocardiographic data, but the shorter skin incision was cosmetically more accepted by patients of the minimally invasive group. Minor paravalvular leaks occurred in four patients of the minimally invasive and three patients of the conventional group as diagnosed by transthoracic echocardiography. CONCLUSIONS: Both surgical techniques may be performed with comparable perioperative and mid-term results, but the better cosmetic result in the minimally invasive group is paid by a longer duration of surgery.

Adult↗
PubMed1999

Metallothionein: localization in human transplant endomyocardium, relation to cytokines and allograft function.

BACKGROUND: The aim of this study was to investigate the role of metallothionein in cardiac transplants in relation to cytokines and allograft function. Recent studies have revealed an association of allograft dysfunction with elevated proinflammatory cytokines independent of cellular rejection. In animal experiments, cytokines induced overexpression of metallothionein, a low-molecular-weight protein implicated in cellular stress response. METHODS: In 105 consecutive biopsies from 15 patients during the first 3 months after heart transplantation, metallothionein expression was investigated immunohistochemically. Its relation to serum interleukin-6, tumor necrosis factor-alpha, interleukin-2 (IL-2), soluble interleukin-2 receptor rejection, and echocardiographic parameters was determined. Forty-three biopsies of 12 patients with idiopathic ventricular tachycardia served as controls. RESULTS: Metallothionein expression was demonstrated in small vessels, cardiomyocytes, fibrocytes, and interstitial round cells. A positive relation between interleukin-6 levels and the number of metallothionein-positive small vessels (p < 0.028) was observed. Patients with lower serum IL-2 levels showed significantly higher numbers of metallothionein-positive small vessels (p < 0.043). Grafts with prolonged ischemic time (>150 minutes) showed a significantly higher myocardial metallothionein score (p < 0.021). Metallothionein expression was associated with lower fractional shortening, larger left ventricular end-systolic diameter, and lower mean arterial pressure but not with acute cellular rejection. CONCLUSIONS: Metallothionein expression is associated with elevated interleukin-6 and decreased interleukin-2 serum levels and left ventricular allograft dysfunction in the absence of rejection.

Acute Disease↗
PubMed1999

A simple new model of physiologically working heterotopic rat heart transplantation provides hemodynamic performance equivalent to that of an orthotopic heart.

BACKGROUND: The widely used non-volume-loaded abdominal heterotopic heart transplant (NL) in rats undergoes atrophy after transplantation. Various techniques have been designed to load the transplanted heart because of its potential immunological impact. Our aim was to create a volume-loaded heterotopic heart transplantation model (VL) capable of ejection and practical for routine studies. Using this model, we tested the hypothesis that VL isografts would retain myocardial performance comparable to native hearts (NH). METHODS: Heterotopic hearts were transplanted using and end-to-side anastomosis between the donor's superior vena cava and the recipient's abdominal inferior vena cava. The right ventricle loads the left ventricle (LV) via a direct anastomosis of the pulmonary artery to the left atrium. The LV ejects volume through an end-to-side anastomosis of the donor's aorta to the recipient's abdominal aorta. Hemodynamic data (systolic and diastolic LV pressures, dP/dt max and min, tau) were studied in-situ (at baseline and after adding volume) and in a Langendorff perfusion system (at baseline and after stimulation with isoproterenol) 2 weeks after transplantation. RESULTS: In situ systolic pressure and diastolic function of VL was superior to NL, and beta-adrenergic stimulated performance in the Langendorff perfusion of VL showed hemodynamic performance equivalent to NH, unlike NL which had a diminished response. CONCLUSION: This technique results in a volume-loaded ejecting heart transplant model that preserves anatomical structures. The VL can be evaluated in situ and after explantation in Langendorff perfusion system and may offer advantages if workload of the graft is of significance to the study performed.

Abdomen↗
PubMed1999

Evolving short-term and long-term mechanical assist for cardiac-failure -- a decade of experience in Münster.

Technological advances and growing expertise has lead to referral of much sicker patients with a greater incidence of heart failure prior to and after cardiac surgical procedures. The diversity of the heart failure patient cohort mandates a differentiated protocol for mechanical support adapted to the clinical requirements. It is desirable to have appropriate mechanical support available for different circumstances of heart failure. In this paper, we review the first decade of the Muenster University Hospital experience with the use of intra-aortic ballon pump, extracorporal membrane oxygenators, short term uni- and biventricular assist systems such as Thoratec and Medos devices, as well as long term left ventricular assist systems such as the TCI Heartmate and the Novacor system. The patient profiles, indications, contraindications, and future trends are reviewed within the framework of a contemporary university hospital Servive.

Assisted Circulation↗
PubMed1999

Left ventricular assist system support is associated with persistent inflammation and temporary immunosuppression.

BACKGROUND: In patients undergoing left-ventricular assist system support, it has not been elucidated to which extent mechanical circulatory support itself as opposed to the underlying condition of endstage heart-failure contributes to perturbation of immune homeostasis. METHODS: In eleven heart transplant candidates who had to undergo Novacor left-ventricular assist device bridging, we prospectively sampled interleukin-6, T-cell and monocyte subsets and compared them to fifteen UNOS status II patients awaiting cardiac transplantation on medical heart failure treatment as outpatients at the time of LVAS implantation/listing decision as well as 2.0+/-1.2 months and 4.5+/-2.3 months later. In order to assess deviations in both groups from normal values, thirty-two healthy subjects served as reference group. RESULTS: Patients undergoing Novacor bridging had higher C-reactive protein, leukocyte, neutrophil, and monocyte levels at all three times, and exhibited lower CD3 +, CD4+, CD3+/CD45 RO T-cell and natural killer cell counts than medically treated patients awaiting transplantation 2 months after the LVAS implantation/listing decision. In comparison to controls, both groups had higher levels of inflammatory activation and lower levels of immunocompetence at all three times. CONCLUSIONS: While both groups of endstage heart failure patients show immunological alterations compared to controls, patients who have to be bridged by the Novacor LVAS exhibit a more pronounced activation of inflammatory markers. This may be due to more advanced heart failure but the device itself also may contribute to more pronounced inflammation and a temporary suppression of immunocompetent cells.

Adult↗
PubMed1999

Milrinone modulates endotoxemia, systemic inflammation, and subsequent acute phase response after cardiopulmonary bypass (CPB).

BACKGROUND: Compromised splanchnic perfusion and the resulting intestinal mucosal injury leads to a decreased mucosal barrier function, which allows translocation of intestinal flora and endotoxemia. The authors evaluated the effects of milrinone on splanchnic oxygenation, systemic inflammation, and the subsequent acute-phase response in patients undergoing coronary artery bypass grafting. METHODS: This open, placebo-controlled randomized clinical study enrolled 22 adult patients in two groups. Before induction of anesthesia, baseline values were obtained and patients were randomized to receive milrinone (30 microg/kg bolus administered progressively in 10 min, followed by a continuous infusion of 0.5 microg x kg(-1) x min(-1)) or saline. The following parameters were determined: hemodynamics; systemic oxygen delivery and uptake; arterial, mixed venous and hepatic venous oxygen saturation; intramucosal pH (pHi); and mixed and hepatic venous plasma concentrations of endotoxin, interleukin 6, serum amyloid A, and C-reactive protein. RESULTS: Milrinone did not prevent gastrointestinal acidosis as measured by pHi, but its perioperative administration resulted in significantly higher pHi levels compared with control. Venous and hepatic venous endotoxin and the interleukin 6 concentration were reduced significantly in the milrinone group. Serum amyloid A values were attenuated in the milrinone group 24 h after surgery. No significant differences could be seen in routinely measured oxygen transport-derived variables. CONCLUSIONS: Perioperative administration of low-dose milrinone may have antiinflammatory properties and may improve splanchnic perfusion in otherwise healthy patients undergoing routine coronary artery bypass grafting.

Acute-Phase Reaction↗
PubMed1999

Pectus excavatum: special surgical technique, perioperative management and long-term results.

BACKGROUND: It is generally accepted that pectus excavatum should be repaired in childhood if possible. The procedure could be performed conveniently even without implantation of any foreign material. In contrast there are several adult patients with aesthenic or marfanoid habitus and poor thorax cosmetics, who seek medical help especially surgical correction due to late awareness or cardiopulmonary dysfunction. METHODS: Between 1989 and 1997, 22 adult patients (mean age 26 years, 18 males and 4 females) underwent repair of the pectus excavatum in our institution. Patients data were analysed retrospectively. Indication was mainly for aesthetics or cardiopulmonary symptoms, in 3 patients for recurrence after primary repair elsewhere. The total surgical repair technique consisted of V-shape osteotomy of the ribs at the outer and inner limit of the funnel and transverse osteotomy of the sternum without displacement of the posterior cortical The sternal and chest wall stabilization in corrected position was performed with at least two metal struts installed transsternal and transversely. In most of our cases other diagonal struts on both sides were needed to achieve further stabilization of the lowest costal cartilages. The metal struts are removed 1 year after the procedure. RESULTS: All repairs were completed with a low complication rate. Chest radiographs and pulmonary function studies were performed routinely before and after corrective surgery. Good to satisfactory chest contour was achieved in 20 patients (91%), with a follow-up from 5 months to 8 years. CONCLUSIONS: Our current technique with perioperative management is successfully performed in adults and will be presented.

Adult↗