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Biomedical subjects

H H Scheld

Publications and source records attributed to H H Scheld.

At least 91 records · Page 5Linked to original sources
PubMed2000

Fetoscopic direct fetal cardiac access in sheep : An important experimental milestone along the route to human fetal cardiac intervention.

BACKGROUND: Fetal cardiac interventions by direct ultrasound-guided approaches or open fetal cardiac surgery have been fraught with technical difficulties, as well as with significant maternal and fetal morbidity in humans. Therefore, the purpose of our study in sheep was to assess the feasibility and potential of fetoscopic direct fetal cardiac access. METHODS AND RESULTS: In 15 anesthetized pregnant ewes (88 to 109 days of gestation; term, 145 days), 3 to 4 trocars were percutaneously placed in the uterus. Using videofetoscopic equipment, we assessed the feasibility of achieving direct fetal cardiac access. Minimally invasive direct fetal cardiac access by operative fetoscopy was achieved in 10 of the 15 fetal sheep. In 7 fetuses, the approach was successfully tested for fetal cardiac pacing (n=5) or antegrade fetal cardiac catheterization (n=2). Access was not achieved in 5 fetuses because of bleeding complications (n=2) or because the fetoscopic setup could not be established (n=3). All but 2 fetal sheep were alive at the end of the procedure. Acute fetal demise resulted from maternal hypotension or kinking of the fetal inferior caval vein by sternal suspension. Six ewes continued gestation; 3 of these went to term, with a normal fetal outcome. Two ewes died from septicemia 3 and 7 days after the procedure, and 1 ewe aborted 1 month after the procedure. CONCLUSIONS: Minimally invasive direct fetal cardiac access by operative fetoscopy is feasible in fetal sheep. The fetoscopic approach carries important potential for fetal cardiac pacing, antegrade fetal valvuloplasties, and resection of fetal intrapericardial teratomas in human fetuses.

Animals↗
PubMed2000

Effect of receiving a heart transplant: analysis of a national cohort entered on to a waiting list, stratified by heart failure severity. Comparative Outcome and Clinical Profiles in Transplantation (COCPIT) Study Group.

OBJECTIVE: To determine whether there is a survival benefit associated with cardiac transplantation in Germany. DESIGN: Prospective observational cohort study. SETTING: All 889 adult patients listed for a first heart transplant in Germany in 1997. MAIN OUTCOME MEASURE: Mortality, stratified by heart failure severity. RESULTS: Within 1 year after listing, patients with a predicted high risk had the highest global death rate (51% v 32% and 29% for medium and low risk patients respectively; P<0.0001), had the highest risk of dying on the waiting list (32% v 20% and 20%; P=0.0003), and were more likely to receive a transplant (48% v 45% and 41%; P=0.01). Differences between the risk groups in outcome after transplantation did not reach significance (P=0.2). Transplantation was not associated with a reduction in mortality risk for the total cohort, but it did provide a survival benefit for the high risk group. CONCLUSION: Cardiac transplantation in Germany is currently associated with a survival benefit only in patients with a predicted high risk of dying on the waiting list. Patients with a predicted low or medium risk have no reduction in mortality risk associated with transplantation; they should be managed with organ saving approaches rather than transplantation.

Acute Disease↗
PubMed2000

Regional expression of protein phosphatase type 1 and 2A catalytic subunit isoforms in the human heart.

In mammalian species, including man, the duration of myocardial contraction is shorter in atria than ventricles. Total contraction time depends at least in part on phosphorylation and dephosphorylation of cardiac regulatory proteins. Dephosphorylation reactions are mediated by protein phosphatases. In the mammalian heart more than 90% of the protein phosphatase (PP) activity consists of PP1 and PP2A. Therefore, the aim of this study was to investigate which isoforms of PP1 and PP2A are present in human myocardium and whether their expression is regionally different. RT-PCR and Northern blotting revealed that all isoforms of PP1 and PP2A presently known are expressed in the human heart. Expression levels of PP1 alpha, delta, and gamma as well as 2A alpha were higher in right ventricles than in right atria. However, there was no such difference for PP2A beta. At the protein level PP1 alpha was unchanged, whereas PP2A was by 56% higher in right ventricles compared to atria. The phosphorylation state of TnI was lower in right ventricle than in right atrium. Thus, lower protein expression of PP2A in atrium could contribute to the faster relaxation by increasing the phosphorylation state of TnI. We conclude that expression of PP1 and PP2A isoforms is regionally regulated in the human heart.

Blotting, Northern↗
PubMed2000

Operative techniques and strategies for minimally invasive fetoscopic fetal cardiac interventions in sheep.

BACKGROUND: Recent efforts to develop procedures for fetoscopic fetal cardiac interventions have been prompted by the development of severe secondary damage to the fetal heart due to semilunar valvar obstructions and the poor outcome of therapy-refractory fetal arrhythmias. The purpose of our manuscript is to analyze and share our experience with the creation of an operative setup for these procedures in sheep. METHODS: We studied a total of 48 fetal sheep between 81 and 106 days of gestation (term, 145 days). After entering the amniotic cavity by a percutaneous approach, we performed various fetoscopic fetal cardiac procedures. We analyzed the success of percutaneous fetal access, methods of trocar support, the incidence and management of trocar dislodgement or accidental insertion into the chorioamniotic space, problems related to amniotic insufflation and trocar placement, as well as techniques for fetal posturing and uterine closure. RESULTS: Percutaneous fetal access was achieved in all sheep. The use of resterilizable trocars substantially decreased the costs of our procedures. Utilizing a percutaneous transuterine purse-string suture for trocar support helped to minimize the number of nonabsorbable T-fasteners remaining inside the uterus postoperatively. As complications such as trocar dislodgement, insertion of the trocar into the chorioamniotic space, and problems with intraamniotic insufflation and gas loss were mastered, conversion to an open operative approach was never required. A novel strategy that we devised for percutaneous fetal posturing permitted adequate fetal posturing with ease and minimal trauma to the fetal skin. CONCLUSION: As operative techniques have become more refined, the feasibility of performing fetoscopic fetal cardiac interventions in human fetuses now depends mainly on technical improvements in imaging and interventional catheters, as well as advances in pacemaker equipment.

Animals↗
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

Emergency coronary artery bypass grafting after failed coronary angioplasty: what has changed in a decade?

BACKGROUND: We assessed the impact of patient and procedural characteristics on the outcome after emergency coronary artery bypass grafting (CABG) for failed percutaneous transluminal coronary angioplasty (PTCA) and temporal changes in these factors. METHODS: Patients who underwent PTCA and subsequent emergency CABG were identified from the databases of the Departments of Cardiology and Cardiothoracic Surgery. RESULTS: Two periods of clinical practice were compared. In 1989 to 1993, 2,880 PTCAs were performed, 64 patients underwent emergency CABG (2.3%), and 7 patients died (10.9%). During 1994 to 1998, 46 patients of 3,801 PTCAs underwent emergency CABG (1.2%, p < 0.01), and 7 patients died (15.2%, NS). The average rate of stenting increased from 0.8% to 24% in 1994 to 1998 as well as the frequency of arterial bypass grafts (0% vs 39%). In the latter period, patients were older, were more often females, had more cardiovascular risk factors, a higher Cleveland score (each p < 0.05), and suffered more often from periprocedural myocardial infarctions (p < 0.001) and nonfatal periprocedural complications (p < 0.01). CONCLUSIONS: Although the frequency of emergency CABG after failed PTCA declined, perioperative mortality tended to increase according to an unfavorable shift in patient risk factors and morbidity.

Adult↗
PubMed2000

Preoperative immunoglobulin treatment in patients with Werlhof's disease undergoing cardiac operation.

BACKGROUND: Patients with Werlhof's disease and undergoing a cardiac surgical procedure with cardiopulmonary bypass are at increased risk for bleeding complications. We report the usefulness of preoperative immunoglobulin treatment in selected patients. METHODS: Between May 1995 and July 1998, 10 patients with Werlhof's disease underwent a cardiac surgical procedure with cardiopulmonary bypass in our department. Five patients with mean platelet counts of less than 80x10(9)/L received immunoglobulin therapy preoperatively (group 1). The other 5 patients with mean platelet counts higher than 80x10(9)/L were not so treated (group 2). RESULTS: In group 1, mean platelet count increased from 54x10(9)/L 5 days before operation to 112x10(9)/L after immunoglobulin treatment (p = 0.018) and did not fall to less than 60x10(9)/L postoperatively. Patients in group 1 received 16 units of packed red blood cells and 5 units of platelet concentrate. Patients in group 2 required 24 units of packed red blood cells, 5 units of platelet concentrate, and 23 units of fresh frozen plasma. Only 1 patient (group 2) had a surgical bleeding complication that required reexploration. Mean drainage loss was 1,100 mL in group 1 and 1,210 mL in group 2. CONCLUSIONS: Our data demonstrate that immunoglobulin treatment of patients with Werlhof's disease and mean platelet counts of less than 80x10(9)/L significantly augments platelet counts preoperatively. It may be useful in selected patients.

Adult↗
PubMed2000

Anticoagulative management of patients requiring left ventricular assist device implantation and suffering from heparin-induced thrombocytopenia type II.

BACKGROUND: Heparin-induced thrombocytopenia type II (HIT II) is a rare but life-threatening side effect of heparin therapy. We describe the perioperative anticoagulative management of patients tested positive for HIT II and requiring implantation of a left ventricular assist device (LVAD). METHODS: We report on 3 patients with a different perioperative anticoagulative management (preoperative, intraoperative, and postoperative anticoagulation with danaparoid-sodium; preoperative anticoagulation with recombinant hirudin, anticoagulation with danaparoid-sodium intraoperatively and postoperatively; preoperative anticoagulation with recombinant hirudin, intraoperative anticoagulation with heparin, and postoperative anticoagulation with danaparoid-sodium) and discuss the difficulties of the treatment. RESULTS: Anticoagulation with alternative drugs such as recombinant hirudin and danaparoid-sodium led to serious and life-threatening bleeding complications as well as to thromboembolic events in the first 2 patients. Therefore the third patient underwent LVAD implantation using heparin for intraoperative anticoagulation to avoid administration of high doses of recombinant hirudin or danaparoid-sodium. Despite very low anti-factor Xa activities, when using danaparoid-sodium postoperatively, the patient suffered from a bleeding complication on the 4th day after LVAD implantation requiring reexploration. CONCLUSIONS: In selected cases (negative heparin-induced platelet aggregation (HIPA) test at the time of LVAD implantation and continuation of postoperative anticoagulation with recombinant hirudin or danaparoid-sodium), heparin may be used for LVAD implantation in HIT II patients to reduce bleeding complications.

Adult↗
PubMed2000

Surgical management of extensive lipomatous hypertrophy of the right atrium.

Lipomatous hypertrophy of the right atrium is a rare lesion that is usually limited to the interatrial septum. The authors report on a patient that suffered from an extensive lipomatous hypertrophy, which protruded into the right and left atrium as well as the superior vena cava and caused inflow obstruction. Therapeutic management is discussed.

Cardiomegaly↗
PubMed2000

Impact of malignant hematological disorders on cardiac surgery.

BACKGROUND: Patients suffering from malignant hematological disorders may be at increased risk, when undergoing cardiac surgery. We report on our experiences with ten cardiac procedures in nine patients (3 males, 6 females, 19-85 yr old, mean age 61 yr). METHODS AND RESULTS: There were two patients with Hodgkin's lymphoma and one patient each with Waldenstrom's syndrome, multiple myeloma, polycythemia, myelodysplasia, chronic lymphocytic leukemia, non-Hodgkin's lymphoma and idiopathic aplastic anemia. Cardiac diseases included coronary artery disease in six, aortic stenosis in two, and mitral insufficiency in one patient. Consecutively, cardiac procedures were coronary artery bypass grafting in six, aortic valve replacement in two, and mitral valve replacement in one patient. No patient died. Postoperatively, one patient suffered from a pericardial tamponade requiring surgical removal and 5 months later from a prosthetic endocarditis necessitating change of the bioprosthesis. One patient developed a superficial wound infection, which was treated conservatively. Four patients received no blood products. Altogether, we transfused 32 packed red blood cells, seven units of fresh frozen plasma and 16 platelet concentrates. Total drainage loss was 883 ml (250-1510 ml). CONCLUSIONS: Cardiac surgery in patients suffering from malignant hematological disorders may be performed, but carries an increased morbidity. Therefore, indications for cardiac procedures must be carefully considered.

Adult↗
PubMed2000

Effect of high dose platelet inhibitor treatment on thromboembolism in Novacor patients.

BACKGROUND: Thromboembolism and bleeding are among the most hazardous complications following implantation of long-term left ventricular support systems. This report focuses on the effect of high dose platelet inhibitor treatment in patients with the Novacor system to prevent thromboembolic events. METHODS: Thirty-eight (out of 58) Novacor patients (43+/-11 years old) were studied in a non-randomized manner. Postimplantation: 20 patients were treated with heparin only (control group), whereas in the other 18 patients aspirin (3x330 mg/day) and dipyridamol (3x75 mg/day) were added to the treatment protocol (aspirin group). RESULTS: Age, body size, underlying heart disease and support interval were comparable among both groups, however, patients in the aspirin group were much sicker with regard to urgency status, postoperative right heart failure and hematologic disorders. Cerebral thromboembolic complications were lower in the aspirin group (33% of patients, 0.4+/-0.7 events) as compared to the control group (55% (P=0.18), 1.4+/-2.3 events (P=0. 048)). Non-cerebral thromboembolism of surgical relevance was rare. The incidence of bleeding complications was mildly increased in the aspirin group. CONCLUSION: The addition of high dose platelet inhibitors seems to lower the incidence of thromboembolism in Novacor patients.

Adult↗
PubMed2000

Are patients with Werlhof's disease at increased risk for bleeding complications when undergoing cardiac surgery?

BACKGROUND: It is generally assumed, that patients with Werlhof's disease (WD) are at increased risk for bleeding complications when undergoing cardiac surgery with extracorporeal circulation. Therefore we performed this case control study to estimate the real risk for bleeding complications of these patients. METHODS: Between 05/95 and 07/98, ten patients with WD (eight males, two females) underwent cardiac surgery employing extracorporeal circulation (WD-group). Five of these patients with platelet counts below 80/nl were treated by immunoglobulins preoperatively. Each patient with WD was matched to five patients without WD (no-WD-group) using diagnosis, age, gender, ejection fraction, number of distal anastomosis and body-mass-index as matching criteria. RESULTS: Mean number of platelet counts were significant lower in the WD-group than in the no-WD-group despite a significant increase of platelet counts after immunoglobulin treatment (54/nl-->112/nl, P=0.018). On the day before, directly after and on the first day after surgery they were 141/nl vs. 215/nl (P=0.012), 75/nl vs. 147/nl (P=0.001) and 93/nl vs. 136/nl (P=0.009). Accordingly, patients of the WD-group received significantly more platelet concentrates than patients of the no-WD-group (mean number of platelet concentrates: 2.3 versus 0.7, P=0.007). Total drainage loss via the mediastinal chest tubes was almost identical (1197 ml in the no-WD-group and 1140 ml in the WD-group). One patient of each group suffered from a bleeding complication requiring reexploration. Three patients of the no-WD-group (6%) and one patient of the WD-group (10%) expired postoperatively unrelated to WD. CONCLUSIONS: Patients with WD may possibly undergo cardiac surgery without a markedly enhanced risk for bleeding complications despite a more than usual transfusion requirement and significantly lower platelet counts perioperatively.

Adult↗
PubMed2000

Selection and management of ventricular assist device patients: the Muenster experience.

BACKGROUND: Because of the growing discrepancy between the availability of donor organs and the number of patients with end-stage heart disease who need heart transplantation, a larger proportion of patients waiting for a suitable donor heart require pre-operative mechanical circulatory assistance. The criteria for the selection and management of these patients as applied at Muenster University Hospital are reviewed. METHODS: The study population consists of 631 patients referred to our center for transplantation between January 1, 1990, and December 31, 1996. Two hundred ninety-seven patients were listed for transplantation and 157 were transplanted. Of 41 patients who underwent implantation of a ventricular assist device (n = 34, Novacor; n = 6, TCI HeartMate; n = 1, Medos), 39 received the device as a bridge to transplantation and 2 as permanent support. For the purpose of the analysis, the study population was divided into 3 groups (elective bridging, urgent bridging, emergency bridging) and compared with heart transplant candidates who did not require mechanical circulatory assistance. RESULTS: Patients who underwent elective or urgent assist-device implantation were younger and had greater hemodynamic compromise than the remainder of patients waiting for heart transplantation, as suggested by a higher functional class and lower mean arterial pressure, cardiac index, serum sodium, and pulmonary artery wedge pressure. Survival of patients who electively underwent implantation of an assist device was better than that of patients who were stable on the waiting list and did not undergo heart transplantation during follow-up. CONCLUSIONS: This finding suggests that earlier implantation of assist devices may facilitate resolution of organ dysfunction before heart transplantation.

Adult↗
PubMed2000

Diagnosis, treatment and outcome of patients with Askin-tumors.

Askin tumors are highly malignant small-round-cell tumors of the thoracopulmonary region, which occur rarely. Therefore, we report on our experiences with eight patients (5 male, 3 females), who were treated in our department between 11'94 and 10'97 (age: 9-40 years, mean age: 20.5 years). All Askin tumors were diagnosed by histological and immunohistochemical examinations as well as molecular genetic proof of characteristic translocations. In all patients, the tumor arose from the chest wall, infiltrating adjacent ribs and parts of the lung. At the time of first diagnosis, five patients did not reveal any metastases. One patient suffered from intrapulmonary metastases and two patients from an infiltration of the diaphragm and of adjacent vertebral bodies. Treatment consisted of a pre- and postoperative (radio-) chemotherapy according to the EVAIA protocol and a radical tumor resection in all patients. The postoperative course was uneventful in seven patients, one patient suffered from pneumonia after multiple wedge resections for intrapulmonary metastases. Four patients, in whom primary tumor resection was complete, are alive 14, 20, 35 and 84 months after first diagnosis - only one patient had to undergo a second operation for a local relapse 17 months after first diagnosis. The other 4 patients, who suffered from a very extensive primary tumor, expired 13, 17, 18 and 39 months after the diagnosis was made. Our data demonstrate that Askin tumors require an aggressive multimodality treatment consisting of pre- and postoperative chemotherapy, radical surgical resection and postoperative irradiation, which may be performed preoperatively in selected cases, too.

Adolescent↗
PubMed2000

Mesenteric blood flow during cardiopulmonary bypass in pigs.

BACKGROUND: Gastrointestinal complications represent a serious problem after cardiopulmonary bypass. Hypoperfusion of the gastrointestinal tract during bypass has been implicated as the cause. We therefore investigated blood flow in the superior mesenteric artery during cardiopulmonary bypass. METHODS: Mature female pigs (n = 12) were investigated. While six sham-operated animals served as control (group I), six pigs underwent normothermic cardiopulmonary bypass for 180 minutes (group II). Bypass flow was 2.4 l/m2/minute. Standard regimens for anesthesia and cardiopulmonary bypass were used. Blood flow in the superior mesenteric artery was assessed by Doppler flowmetry. RESULTS: Blood flow in the superior mesenteric artery did not change significantly in group I. In group II, mesenteric blood flow increased significantly from baseline at 120, 150, and 180 minutes. Oxygen consumption in the mesenteric circulation increased significantly in group II at 90 and 180 minutes compared to baseline, as well as oxygen extraction. Lactate content in the mesenteric vein in group II increased compared to control at 30, 90 and 180 minutes. CONCLUSION: Overall gastrointestinal blood flow is not impaired during cardiopulmonary bypass in this animal model. Instead, gastrointestinal blood flow increased during normothermic cardiopulmonary bypass as well as oxygen consumption.

Animals↗