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Biomedical subjects

A Henze

Publications and source records attributed to A Henze.

At least 37 records · Page 2Linked to original sources
PubMed1991

Decreased liberation of noradrenaline from the heart following cold crystalloid cardioplegia.

Exogenous catecholamine support is often needed soon after termination of cardiopulmonary bypass even when appropriate cardioplegia has been used. To study the effect of hypothermic cardioplegic ischemia and reperfusion on the activity of the cardiac sympathetic nervous system, plasma noradrenaline concentration in the coronary sinus and general circulation was measured in six patients undergoing valve replacement for nonischemic mitral disease. Before cardiopulmonary bypass and cardioplegia the release of noradrenaline from the heart was greater than the mean systemic release. After ischemia, during reperfusion, the heart tended to extract noradrenaline, and 10 min after termination of bypass the plasma noradrenaline gradient over the heart remained less than pre-bypass. The results indicated decreased activity of the cardiac sympathetic nervous system, which may explain the frequent need for catecholamine support.

Cardiopulmonary Bypass↗
PubMed1990

Myocardial revascularization with three native in situ arteries. Gastroepiploic and bilateral internal mammary artery grafting.

Three native arteries were used for coronary artery bypass grafting in six patients in whom complete revascularization was not feasible because of varices or previous venous stripping. The right gastroepiploic and both internal mammary arteries were placed as pedicled conduits, and four patients additionally received a total of six vein grafts available from the greater or lesser saphenous system. Surgical complications were minimal and complete relief from angina was obtained in all patients, even in maximal stress testing. All 24 grafts were angiographically checked: 23 (96%) were patent and one gastroepiploic artery was occluded. All patients had at least three patent grafts. These native arteries are excellent conduits when suitable veins are not available. They should also be used on individual indications to replace occluded grafts.

Adult↗
PubMed1989

Bilateral internal mammary artery for coronary revascularization. Early experience of 100 cases.

One hundred cases are presented in which both right and left internal mammary artery (IMA) were used as coronary bypass grafts. Special indications were thrombosis of previous venous graft (14 cases), poor venous resources (10) and small-vessel (probe less than 1.5 mm) disease (34), but bilateral IMA was used also for routine revascularization (42 cases). The total 212 distal IMA anastomoses included 12 jump grafts, three free grafts and seven thrombendarterectomies. There were 3.8 distal anastomoses per patient, 2.1 with IMA and 1.7 with vein graft. The right IMA was preferably inserted into LAD and the left into diagonal or obtuse marginal coronary artery. Excessive postoperative bleeding was the only major complication attributable to bilateral IMA grafting in the 97 survivors of surgery. In routine revascularization the procedure involved minimal morbidity and no mortality. The superiority of the IMA as regards long-term patency is widely recognized. Since many thrombosed vein grafts will require replacement, we believe that bilateral IMA grafting will become common, and it is also an option when no suitable vein is available.

Adult↗
PubMed1989

The internal mammary artery free and flap aortoplasty in coarctation of the aorta.

A technique for correction of aortic coarctation is described in which the left internal mammary artery (IMA) is distally divided for integration in the repair. After resection of the internal coarctation ridge, the distal end of the freed IMA is obliquely severed, opened to required length and thus fashioned as a widening flap suitable fro aortoplasty. IMA free end flap aortoplasty gave promising early results in seven patients aged 10-15 years with aortic coarctation and IMA of good quality and calibre.

Adolescent↗
PubMed1989

The internal mammary artery origin flap aortoplasty in coarctation of the aorta.

The left internal mammary artery (IMA) was divided proximally to form an integral part of the repair in coarctation. After resection of the internal coarctation ridge, the origin of the IMA was obliquely divided, opened to required length and thus fashioned as a widening flap for aortoplasty. This procedure preserves distal continuity of the IMA with direct blood supply to the breast. The 'origin flap' aortoplasty gave promising early results in six patients and 10-17 years with aortic coarctation and IMA of suitable calibre and good quality.

Adolescent↗
PubMed1989

Intra-aortic balloon counterpulsation with special reference to determinants of survival.

From 1981 through 1985 intra-aortic balloon counterpulsation (IABP) was required by 90 patients on a total of 91 occasions. They included 85 (3.1%) of the 2751 patients undergoing open-heart surgery during that time. IABP was used preoperatively in 13 cases, to assist weaning from cardiopulmonary bypass in 64, postoperatively in nine, and without cardiac surgery in five cases. Complications arose from IABP in 24/90 patients (27%). The overall short-term survival rate following IABP was 61%, and the long-term (mean 23 months) rate was 51%. Early recovery of cardiac function was the main determinant of survival. Female sex, renal failure and postinfarction ventricular septal defect and mitral incompetence were over-represented among the nonsurvivors. IABP therefore is useful in reversible left ventricular dysfunction, whereas inadequate perfusion of vital organs with potential for failure of more than one organ system implies diminished likelihood of survival.

Aged↗
PubMed1989

Neonatal endocarditis requiring surgery.

A case of infective endocarditis in a neonate is reported. Echocardiography demonstrated a large (1 X 1.5 cm) vegetation on the anterior mitral leaflet protruding into the ventricle during diastole. The left atrium was enlarged and Doppler showed mitral regurgitation. Excision of the vegetation during effective antibiotic treatment involved no complications. Although histologically the endocarditis was in the early stage of healing, surgical removal of large, floppy vegetations is advocated because of the unpredictable risk of catastrophic embolization.

Anti-Bacterial Agents↗
PubMed1988

Complications of intra-aortic balloon counterpulsation, with special reference to limb ischemia.

During a 5-year period, intra-aortic balloon pumping (IABP) was performed on 90 patients (3.1% of those undergoing open-heart surgery), using a Percor catheter inserted with Seldinger technique. Overall prognosis was poor; only 46 of the 90 patients were alive at postoperative follow-up averaging 23 months. Limb ischemia arose in 20%, with incidence uninfluenced by catheter insertion technique (percutaneous v. 'open'). Surgical treatment was required for half of the ischemic limbs. Groin hematoma commonly followed percutaneous extraction of IABP catheter, whereas 'open' removal was always hemostatic, with potential for embolectomy. Percutaneous insertion of IABP catheter via the femoral artery is the method of choice in an emergency situation. 'Open' Seldinger technique is preferable in the operating room. For elective IABP catheter removal, the 'open', hemostatic technique is recommended. If limb-threatening ischemia develops, the catheter must be removed. If the patient is IABP-dependent, the contralateral femoral artery or the ascending aorta should be considered as an alternative catheter route.

Female↗
PubMed1987

Myocardial enzyme activities in patients with mitral regurgitation or mitral stenosis.

To determine the adaption of myocardial metabolism in mitral regurgitation and mitral stenosis, human papillary muscles obtained during open heart surgery were analysed to measure selective enzyme activities in energy metabolism. All enzyme activities were expressed per unit dry weight muscle, per unit alkali soluble protein, and per unit total creatine and the different results compared. The activities of enzymes concerned with mitochondrial energy production and energy transfer (namely, citrate synthase and mitochondrial creatine kinase) tended to be higher in papillary muscles from hearts with mitral regurgitation than in those with mitral stenosis. The activities of enzymes concerned with cytoplasmic energy production (creatine kinase MM, lactate dehydrogenase, and phosphofructokinase) did not show statistically significant differences between mitral regurgitation and mitral stenosis. The ratio of creatine kinase MB activity to total creatine content showed the greatest difference when papillary muscles from patients with mitral regurgitation and mitral stenosis were compared (31% higher in mitral regurgitation; p less than 0.001). The specific function of creatine kinase MB, which is located in cytoplasm, is not well defined. Creatine kinase MB activity increases with extreme endurance training of human skeletal muscle. Thus the higher creatine kinase MB activity in papillary muscle of mitral regurgitation may represent an adaptation to increased physical demand.

Adult↗
PubMed1987

Enhanced mitogenic reactivity of human T cells after passage through the thymus. Response to phytohemagglutinin and mercuric chloride.

Lymphocytes in blood samples taken from the thymic, brachiocephalic and internal jugular vein of children undergoing thoracic surgery were compared regarding their phenotypic markers and their proliferative response to mercuric chloride (HgCl2) and phytohemagglutinin (PHA). Of these two mitogens, PHA stimulated the DNA synthesis of the lymphocytes from the thymic vein to a significantly higher degree than those taken from the brachiocephalic or internal jugular vein. The response to HgCl2 resulted in the highest stimulation of the DNA synthesis in cells from the thymic and the brachiocephalic veins, though the differences were not significant. The higher reactivity to PHA and the tendency to higher reactivity to HgCl2 of lymphocytes taken from efferent thymic blood might be due to a higher frequency of T cells. This, however, could not be verified by immunohistochemical staining, as Leu4-positive cells occurred in the same proportion in all three venous samples. We therefore suggest that the passage through the thymus of circulating T cells may increase their immune reactivity by the influence of thymic maturation hormones.

Humans↗
PubMed1987

The internal mammary artery as subclavian artery substitute in repair of coarctation of the aorta with subclavian flap technique.

In three children, aged 11, 11 and 13 years, long isthmic tubular hypoplasia of the aorta technically precluded resection and end-to-end anastomosis. The coarctation was instead corrected by means of a subclavian flap. Anastomosis between the distal end of the left internal mammary artery and the descending aorta permitted perfusion of the remaining portion of the subclavian artery. At invasive reexamination 6 months after surgery, there was adequate functional and anatomic relief of coarctation in all three children. The three mammary artery-aorta anastomoses were patent, which probably prevented the potential ischemia of the left arm after ligation of the subclavian artery.

Adolescent↗
PubMed1987

Preservation of myocardial high-energy phosphates in open-heart surgery with deep general hypothermia and multidose crystalloid cardioplegia.

Myocardial energy metabolism during deep general hypothermia (20 degrees C) and multidose crystalloid cardioplegia, and also during subsequent reperfusion, was studied in eight patients undergoing isolated aortic valve replacement. Six serial transmural biopsy samples from the left ventricular apex were analyzed for high-energy phosphates and their degradation products. Reductions in ATP, total adenine nucleotide content and energy charge were insignificant during cardioplegia, as were changes in adenosine and uric acid concentrations. During reperfusion, however, there was slight but significant reduction in total adenine nucleotide content, despite adequate oxygenation as indicated by reversal of lactate accumulation. These observations suggest that the reperfusion phase is accompanied by metabolic aberrations which are not overcome by good oxygenation in relation to the metabolic rate.

Adenine Nucleotides↗
PubMed1987

Extended intrathoracic resection for lung cancer. Follow-up of 49 cases.

Extended resection was performed for primary lung cancer (stage III) on 49 patients in 1973-1982. Their mean age was 61 (38-76) years. In addition to pneumonectomy (29) or lobectomy (20), surgery included resection of the thoracic wall (8 cases) left atrium (12), pericardium (15), parietal pleura (13) and oesophagus (1 case). Among the 47 "surgical survivors" (96%), the mean survival time was 19.9 +/- SD 20.3 months, and only four patients (9%) were alive after 5 years or more. The cumulative 5-year survival was 14% (4/29 patients). Poorly differentiated tumour forms (squamous cell cancer) carried the worst prognosis, whereas the type of resection and presence or absence of lymph-node metastases did not per se influence survival. The prognosis in extended resection is poorer than in standard lung resection, but superior to that in simple exploration. The surgeon therefore should always be prepared to extend a planned resection when a patient on the operating table is found to have extension of lung cancer to other intrathoracic organs, since only in invasion of the chest wall is the surgical strategy as a rule clear from the outset.

Adenocarcinoma↗
PubMed1987

Three-year clinical results with the Monostrut Björk-Shiley prosthesis.

Between November 1981 and June 1983, 351 patients underwent valve replacement with the Monostrut Björk-Shiley prosthesis. There were 214 aortic valve replacements, 101 mitral valve replacements, and 31 double (aortic and mitral) valve replacements. Four patients had valve implanted in the tricuspid position, and one patient underwent exchange of a valved, extracardiac conduit. Mean age was 61 years (range 2 to 78) and 186 (53%) were male. Concomitant procedures were performed in 52 patients (15%) and 17 (5%) were emergency operations. Early mortality (4.3%) was related to New York Heart Association Functional Class IV, emergency operation, or the presence of a concomitant procedure. Follow-up was 100% and covered 870 patients-years (mean 2.6 years per operative survivor). Postmortem examination was performed in 38 (79%) of the 48 fatalities. Only one patient suffered a sudden, unexplained death. The 3 year survival rate (early mortality excluded) was 88.6% (aortic valve replacement 89.2%, mitral valve replacement 89.3%, and double valve replacement 82.5%). The 3 year freedom from thromboembolism in patients receiving anticoagulants was as follows: aortic valve replacement 97.5%, mitral valve replacement 92.8%, and double valve replacement 100%. There were no instances of valve thrombosis or fatal embolism. In contrast, there were two instances of aortic valve thrombosis among 34 patients having aortic valve replacement without anticoagulation. The 3 year freedom from valve failure (modified Stanford definition) was as follows: aortic valve replacement 96.0%, mitral valve replacement 93.9%, and double valve replacement 89.7%. There were no mechanical failures. In conclusion, the Monostrut Björk-Shiley valve showed a low incidence of complications. There were no mechanical failures, no fatal emboli, and, when anticoagulants were administered, no valve thromboses.

Actuarial Analysis↗
PubMed1986

Thrombendarterectomy in chronic pulmonary embolism. Reports of 3 cases.

Thrombendarterectomy of the pulmonary artery was performed in three cases of chronic pulmonary embolism with pulmonary hypertension and right heart failure. The indications for such tissue-preserving surgery are discussed against the background of the presented cases and of the literature. These indications are unilateral vascular obstruction with good run-off in combination with "moderate" pulmonary hypertension. Patients with peripheral vascular changes in both lungs and equilibrated pressures respond poorly to thrombendarterectomy and present high surgical risk. For such patients hope lies in future resources for combined heart-lung transplantation.

Adult↗
PubMed1985

Release patterns of CK-MB and mitochondrial CK following myocardial ischaemia.

Following myocardial damage as in acute myocardial infarction (AMI) or open heart surgery, the tissue damage might result in a release of mitochondrial CK (CK-MIT). The presence of this CK isoenzyme in serum may be detected after chromatographic separation of CK-activity on Sephacryl S-200. By combining chromatographic separation of CK-MB with immunologic inhibition of CK-M, both CK-MB and CK-MIT can be estimated in serum. Using this procedure changes in enzyme activities were studied in ten patients with AMI and twelve patients subjected to open heart surgery using cardioplegia. Following AMI CK-MB peaked about 24 h after onset of ischaemic symptoms. CK-MIT increased similarly and reached a plateau after 24 h where it remained during an additional 24-36 h. At peak CK-MB concentration, the corresponding CK-MIT activity was about 22% of the CK-MB activity. Following cardiac surgery there was a rapid release of CK-MB with a peak about 5 h after release of aortic cross-clamping, and with a simultaneous CK-MIT activity amounting to 19% of the CK-MB activity. In conclusion, CK-MIT is released into serum following myocardial ischaemia. Its appearance has time characteristics similar to that of other mitochondrial enzymes. The CK-B method does not specifically determine CK-B, but non-CK-M, which in cardiac ischaemia at peak serum CK-MB concentrations includes about 20% CK-MIT.

Adult↗
PubMed1985

The monostrut strength.

The fatigue endurance limit for Haynes 25 from which the Björk-Shiley (B-S) valve is made is 4900 kg per square centimeter (70000 pounds per square inch). A welded strut may have a variation of fatigue endurance limit from 4900 kg per square centimeter (70000 pounds per square inch) in an incomplete weld with phase segregation. To avoid a weld with this variation, the monostrut has been developed, where the valve is made by electrochemical machining from one piece of Haynes 25. The homogenous outflow monostrut will then have a stable fatigue endurance limit of 4900 kg per square centimeter (70000 pounds per square inch). In a pulse duplicator at a pulse rate of 120 and a peak ventricular pressure of 200 mmHg, the maximum inservice tensile stresses for the 29 mm valve outflow strut do not exceed 700 kg per square centimeter (9800 pounds per square inch). Therefore, a seven times safety limit is present for the monostrut under maximal physiological stress conditions. The struts in the B-S monostrut valve cannot be fractured even under extreme experimental conditions and never under peak physiological conditions.

Equipment Design↗