Emergency coronary angiography with gadolinium in a patient with thyrotoxicosis, pulmonary embolism and persistent right atrial thrombi.
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Contrast Media↗
Biomedical subjects
Hans-Hinrich Sievers
Publications and source records attributed to Hans-Hinrich Sievers.
Complex reconstruction of the thoracic aorta using a novel stent graft/graft prosthesis.
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Aged↗
In-vitro study on the relationship between progressive sinotubular junction dilatation and aortic regurgitation for several stentless aortic valve substitutes.
OBJECTIVE: Stentless aortic valves are widely used due to their excellent hemodynamic properties. However, if the subcoronary implantation technique is used later dilatation of the sinotubular junction (STJ) can cause regurgitation. The aim of the study was to determine the dilatation tolerance of two commercially available stentless xenografts and fresh aortic and pulmonary roots against such dilatation. METHODS: Four groups each comprising five specimens of fresh porcine aortic roots, pulmonary roots, Medtronic freestyle or Toronto SPV Xenografts were tested in a mock circulation using a special device for gradually increasing the diameter of the sinotubular junction. The smallest diameter D(r) where regurgitation occurs was measured and correlated with the starting diameter D(a) and expressed as per cent values. Opening and closing patterns were obtained by a high speed camera and flow characteristics were determined. RESULTS: The highest dilatation tolerance of STJ was found in the fresh porcine aortic roots (165%+/-10) followed by fresh pulmonary roots (146%+/-12), the Freestyle (143%+/-4) and the SPV (132%+/-5) bioprostheses. All differences were significant with P< or =0.05 except that between the fresh pulmonary roots and the two commercial available bioprostheses. CONCLUSIONS: Our results indicate that aortic homografts provide higher resistance against regurgitation induced by dilatation of the STJ than an autograft or the stentless xenografts, Freestyle xenograft followed by the Toronto SPV. The use of the full-root technique should be considered if aortic dilatation seems to be likely.
Aortic Valve↗
Mid-term findings on echocardiography and computed tomography after RVOT-reconstruction: comparison of decellularized (SynerGraft) and conventional allografts.
OBJECTIVE: The immune response against human-leucocyte-antigens on donor-cells may be an important factor contributing to the degeneration of allograft-valves. We have previously reported that the use of the decellularized allograft SynerGraft (CryoLife) reduces the immunologic response of the allograft-recipient. In this study we compare the echocardiographic and computed tomography angiographic (CTA) findings of SynerGrafts with conventional cryopreserved allografts. METHODS: 22 patients who received a pulmonary SynerGraft (SG-group) (21 during a Ross-procedure) underwent CTA and resting echocardiography (median: 10 months postoperatively). 47 randomly chosen patients who underwent a Ross-procedure served as controls (C-group) (median: 32 months postoperatively). RESULTS: Neither the pressure gradients (mean: SG=9+/-4 vs C=10+/-4mmHg; P=0.64) across the allograft, nor the effective orifice area (EOAI) (SG=0.93+/-0.80 vs C=0.93+/-0.42cm(2)/m(2); P=0.96) differed between the groups. The EOAI showed a significant correlation with the smallest allograft-conduit-area measured on CTA (r=0.81; P<0.001) which was most frequently (n=34) found in the proximal postvalvular tubular part of the conduit. Calcifications (n=11) or a fibroproliferative reaction (n=15) were rarely observed. Overall, there were no radiologic differences between the groups. On CTA, the smallest diameter of the allograft-conduits was significantly smaller than the diameter given on the cryopreservation protocol (SG=16+/-3 and C=17+/-3mm vs 25mm in both groups; P<0.001 each) whereas the diameter of the distal part of the allograft was not (SG=24+/-2, P=0.066, and C=25+/-3mm, P=0.82). CONCLUSIONS: Despite a significant shorter follow-up in the SynerGraft-group, no functional or radiologic differences were observed as compared to control-patients. The smallest diameter is located almost exclusively at the proximal level of allograft-conduits.
Adult↗
Prosthetic aortic valve replacement.
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Anthropometry↗
Expression of the erythropoietin receptor in human heart.
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Blotting, Western↗
Ubiquitin fusion degradation 1-like gene dysregulation in bicuspid aortic valve.
OBJECTIVE: Bicuspid aortic valve, the most common congenital cardiac malformation, is caused by fusion of valve cushions at the onset of valvulogenesis. Although its exact pathogenesis is still unclear, a genetic basis is appearing more and more likely. Search for a potential candidate gene by reviewing semilunar valve morphogenesis led us to the ubiquitin fusion degradation 1-like gene (UFD1L), which is highly expressed in the cardiac outflow tract during embryogenesis. METHODS: Aortic valves were collected during surgery from 39 patients with bicuspid aortic valve (mean age 56.8 +/- 18.1 years) and from 38 patients with tricuspid aortic valve (mean age 61.7 +/- 16.1 years). Fluorescence in situ hybridization was performed for detection of microdeletion, quantitative reverse transcriptase-polymerase chain reaction to measure gene expression, and Western blotting to analyze the amount of UFD1L gene product. RESULTS: No microdeletion was found in either group in the critical region of chromosome 22 containing the UFD1L gene. UFD1L gene expression, however, was significantly reduced in bicuspid aortic valve samples (median 787-fold) relative to tricuspid aortic valve samples (median 10,887-fold, P = .001). The amount of UFD1L gene product was also significantly diminished in bicuspid aortic valve samples (3.9 +/- 2.6 vs 8.4 +/- 4.8 optical density units, P < .05). CONCLUSION: Bicuspid aortic valve was associated with downregulation of UFD1L gene expression, supporting the hypothesis that bicuspid aortic valve is a genetic disorder, with the UFD1L gene as a potential candidate gene.
Adaptor Proteins, Vesicular Transport↗
Myocardial redox state during coronary artery bypass grafting assessed with microdialysis.
PURPOSE: Microdialysis allows the biochemical analysis of interstitial fluids of nearly every organ as a bedside procedure. This technique could be useful to reveal data about the myocardial metabolism during cardiopulmonary bypass in human coronary artery bypass graft (CABG) surgery. METHODS: In 17 patients undergoing CABG a myocardial microdialysis catheter (CMA 70, CMA/Microdialysis AB, Sweden) was inserted in the apical region of the beating heart. Microdialysis measurements were performed at timed intervals before, during, and after cardiopulmonary bypass (CPB). The concentrations of lactate and pyruvate were analyzed semi-continuously. RESULTS: During CPB the myocardial lactate-pyruvate-ratio (LPR) rose from an initial 11 (8-15) to 33 (29-41) ( P<0.01). After CPB the LPR decreased to 4 (3-7) at the end of observation ( P<0.05). The pyruvate concentration showed an immediate increase from 34 (30-42) microM at the end of CPB to 181 (147-234) microM after removal of the cross-clamp with subsequent increase during reperfusion ( P<0.01). Plasma lactate and pyruvate showed no essential changes during the study. CONCLUSION: Using the microdialysis technique it was possible to analyze myocardial metabolic changes during CABG. The course of myocardial LPR as a sensitive indicator of the myocardial redox state showed profound changes during and after CPB. We propose the microdialysis technique as an additional monitoring tool in CABG.
Aged↗
Emergency endovascular stent-grafting for life-threatening acute type B aortic dissections.
BACKGROUND: There is still a considerable controversy regarding optimal treatment for patients with acute type B aortic dissection. Patients with complicated disease are particularly challenging for cardiovascular treatment. Early surgery for acute dissections of the descending aorta with life-threatening complications is known to carry a high mortality. Endovascular stent grafting is developing as an alternative treatment mainly for chronic stages of type B aortic dissection. It is not clear whether endovascular stent grafting is safe and effective in emergency treatment of acute type B aortic dissection. METHODS: In 10 patients (7 men, 3 women; mean age, 59.2 years; range, 46 to 65 years), endovascular stent grafting was performed within 11.0 +/- 5.9 hours (range, 4 to 24 hours) of diagnosis of complications. Indications for acute intervention included contained rupture, hematothorax, life-threatening malperfusion, and refractory pain. Using a retrograde endovascular route after surgical exposure of the femoral artery, self-expanding stent prostheses consisting of polyester-covered Nitinol (Talent, World Medical; mean diameter, 40 +/- 4 mm; length, 10 cm) were placed into the descending aorta distal to the subclavian artery. Before discharge and on follow-up visits, imaging of the aorta was performed using computed tomography. RESULTS: In 9 of 10 patients (90%), the primary entry could be completely occluded with the endovascular stent. Early mortality was 20% (2 of 10): 1 patient died after disruption of the intimal layer distal to the stent, and 1 patient died in hemorrhagic shock after surgical fenestration of the abdominal aorta for persistent malperfusion. Three patients (30%) required consecutive surgical treatment: indications included acute development of retrograde type A aortic dissection, acute stent dislocation by fractured wires and secondary leakage, and late formation of an aneurysm of the descending aorta 6 months after endovascular stent grafting. There were no surgical or late deaths. CONCLUSIONS: Our experience provides some evidence that early mortality of life-threatening acute type B aortic dissection may be reduced by emergency endovascular stent grafting and that this form of treatment is a promising therapeutic option. Refinements, especially in stent design and application, may further improve the prognosis of patients in the life-threatening situation of complicated acute type B aortic dissection.
Acute Disease↗
High incidence of sudden death late after anterior LV-aneurysm repair.
OBJECTIVES: Sudden death due to ventricular arrhythmias occurs frequently among patients with dilated cardiomyopathy and congestive heart failure (CHF). In patients with left ventricular (LV) aneurysms, LV-aneurysm repair (LVAR) reduces LV-size and ameliorates symptoms of CHF, but the incidence of late sudden death is unknown, especially after LVAR without concomitant anti-arrhythmic therapy. METHODS: Between June 1993 and June 1999, 147 patients (70% males; 62+/-9 years) with CHF (median: NYHA III) due to anterior LV-aneurysms underwent LVAR. None of the patients underwent anti-arrhythmic surgical procedures concomitant to LVAR. Ninety percent of the patients had additional myocardial revascularization. Hospital records and laevocardiograms were reviewed, and follow-up information was obtained. RESULTS: In-hospital mortality was 4.1% (n=6). The median follow-up was 3.7 years (0.1-73.4 months; overall 462 patient-years). At follow-up, the patients had significantly less symptoms than preoperatively (median: NYHA II, P<0.001). Nineteen patients had died (5-year survival rate 78%). Of these late deaths, 84% (n=16) were cardiac-related, among which sudden death was most frequent (n=7). Predictors of sudden death were a bypass graft to the right coronary artery (P=0.0100), ventricular tachyarrhythmias early postoperatively (P=0.0315), and cross-clamp time (P=0.0496). CONCLUSIONS: Although the survival and functional state of most patients were good after LVAR without concomitant anti-arrhythmic surgery, we observed a high incidence of late sudden death, which was-among others-significantly associated with postoperative ventricular tachyarrhythmias. To further improve outcomes, intra- and postoperative anti-arrhythmic therapy is advisable in patients undergoing LVAR.
Aged↗
Intramyocardial oxygen monitoring in coronary artery bypass surgery.
OBJECTIVE: In coronary artery bypass surgery various parameters have been used to monitor patients clinical status. Direct monitoring of myocardial oxygenation can be performed by measuring intramyocardial partial oxygen tension pressure (p ti O2). This study was performed to determine the perioperative time course of this parameter in correlation to standard monitoring parameters. METHODS: Twenty-three patients underwent standard coronary artery bypass grafting (CABG). A special polarographic microprobes was inserted into the myocardium in the distribution zone of the left anterior descending artery which was one of the target vessels of myocardial revascularization. Intramyocardial p ti O2 was monitored intra- and up to 12 hours postoperatively. Values were correlated to hemodynamic, oxygenation and procedure associated parameters. RESULTS: Myocardial oxygenation during CABG is characterized by a significant decrease of p ti O2 during cross-clamping and a significant increase after removal of the cross-clamp. The postoperative time course of p ti O2 shows a steady increase of p ti O2 in the first 12 postoperative hours investigated. Preoperative ejection fraction as well as cardio-pulmonary bypass time does not seem to have an influence on the postoperative p ti O2 in these patients. Various standard monitoring parameters show complex influence on intramyocardial p ti O2- CONCLUSIONS: Determination of intramyocardial partial oxygen pressure in patients undergoing bypass surgery shows characteristic changes. Changes in p ti O2 as a direct online parameter of myocardial oxygenation occur immediately after procedures that influence myocardial perfusion and therefore, may help to detect potential complications earlier than standard monitoring parameters in cardiac surgery.
Aged↗
Intercompartmental fluid volume shifts during cardiopulmonary bypass measured by A-mode ultrasonography.
To investigate the time course of fluid extravasation during cardiopulmonary bypass (CPB), we measured the peripheral tissue thickness (TT) by A-mode ultrasound in 34 patients undergoing elective cardiac surgery. TT of the forehead was determined by a handheld A-mode ultrasound device and 10 MHz Transducer at nine defined intervals, from the night before surgery until the first postoperative day. Mean calculated loss of 1700 +/- 40 mL (SEM) water during the fasting period resulted in a significant reduction of TT by 0.28 +/- 0.03 mm. From induction to start of CPB, rehydration with 1000 mL of fluid was performed and TT increased to baseline. After 60 min of extracorporal circulation, forehead TT increased significantly by 0.75 +/- 0.08 mm and remained unchanged until the end of surgery when the measured fluid gain was 1580 +/- 138 mL. At discharge from ICU, negative fluid regimen resulted in a balance of -127 +/- 146 mL whereas TT declined significantly to +0.16 +/- 0.09 mm compared to baseline. Dehydration due to fasting and the marked interstitial fluid extravasation during CPB could be detected by the changes of the peripheral TT. We conclude that parts of the fluid load during CPB are shifted from the intravascular compartment to the interstitial space in a time-dependent manner.
Aged↗
Specific regional and directional contractile responses of aortic cusp tissue.
BACKGROUND AND AIM OF THE STUDY: The control of valve size and function is a dynamic process that may be modulated by vasoactive factors. The exact response of different regions of the cusp tissue with regard to extent and direction could influence valve shape, function and response to stress. METHODS: Porcine aortic valve cusps were cut into either circumferential (basal, belly and coapting edge) or radial (left, center and right) strips. Together with an intact cusp orientated circumferentially, specimens were set up in isolated organ baths. RESULTS: In response to 90 mM KCI, the belly of the cusp (0.66 +/- 0.05 mN; p <0.05) was significantly more responsive than either the basal region (0.41 +/- 0.06 mN) or the coapting edge (0.31 +/- 0.03 mN) and all three regions of radially orientated strips (left: 0.13 +/- 0.02 mN; center: 0.23 +/- 0.04 mN; right: 0.11 +/- 0.03 mN). All strips showed contraction to endothelin-1 (10(-9) to 10(-7) M). When corrected for weight, the responses of the basal (15.2 +/- 1.8 mN/g) and belly (11.3 +/- 1.5 mN/g) regions were significantly greater than that of the coapting edge (8.4 +/- 1.0 mN/g; p <0.05) and the intact cusp (7.1 +/- 1.9 mN/g, n = 7, p <0.05). In the radially orientated tissue, responses to endothelin-1 were similar in all three regions (left: 3.4 +/- 1.0 mN/g; center: 3.2 +/- 0.5 mN/g; right: 2.3 +/- 0.9 mN/g). CONCLUSION: The contractile ability of valve cusps occurs preferentially in the circumferential direction. The enhanced contraction of the basal region may have important implications for the management of stresses experienced by the hinge of the valve. In addition, these findings may be relevant in designing tissue for valve repair by cusp extension or for the tissue engineering of a whole valve.
Animals↗
Local generation of C-reactive protein in diseased coronary artery venous bypass grafts and normal vascular tissue.
BACKGROUND: Venous coronary artery bypass grafts (CABGs) are prone to accelerated atherosclerosis. In atherosclerotic diseases, serum C-reactive protein (CRP) levels have become an important diagnostic and prognostic marker. The origin of CRP in this setting remains to be elucidated. METHODS AND RESULTS: Monoclonal anti-CRP identified CRP expression in medial and intimal alpha-actin-positive smooth muscle cells (SMCs) of diseased CABGs with type V and VI lesions and also of native saphenous veins of atherosclerotic individuals. In addition, patent coronary arteries with type IV and V but not with type I through III lesions exhibited intense SMC staining for CRP. Calcified desobliterates of occluded coronary arteries with end-stage disease did not show SMC staining for CRP and were consistently negative for CRP mRNA, as detected by means of real-time polymerase chain reaction. However, CRP mRNA was expressed in 11 of 15 diseased CABGs and also in 10 of 15 native veins. By contrast, only 3 of 18 internal mammary and 4 of 12 radial arteries with virtually no atherosclerosis were positive for CRP mRNA. CONCLUSIONS: CRP is produced by SMCs of atherosclerotic lesions with active disease but not in end-stage plaques. The role of CRP constitutively expressed by normal vascular tissue in vein graft disease has yet to be elucidated.
Arteriosclerosis↗
Low-energy cardioversion versus medical treatment for the termination of atrial fibrillation after CABG.
BACKGROUND: Atrial fibrillation (AF) is the most frequent complication after cardiac surgery and can cause considerable morbidity. Low-energy cardioversion (LEC) using biatrial epicardial wires implanted during surgery has been shown to be effective and safe in conscious patients, but has not been directly compared with medical treatment so far. We therefore prospectively studied the efficacy of LEC in men 60 years of age and older. METHODS: Sixteen patients (mean +/- SD, 66.4 +/- 5.4 years) were randomized to LEC and 32 patients (66.3 +/- 5.0 years) to standarized medical treatment in the event of postoperative AF. Age, comorbidity, and surgical variables did not differ significantly between the groups. RESULTS: After cardiac surgery, AF occurred in 6 patients (38%) assigned to LEC and in 11 patients assigned to medical treatment (34%; p = NS). Low-energy cardioversion restored sinus rhythm in all but 1 patient, and 1 patient in the LEC group had early recurrence of AF. All other patients in the LEC group had prompt and stable restoration of sinus rhythm. Medical treatment was associated with the restoration of sinus rhythm in all patients. Although the total time in AF was decreased significantly by LEC (median 5 minutes versus 22 hours; p = 0.037), the length of postoperative hospitalization was not (5.1 +/- 1.4 days for the LEC group compared with 5.3 +/- 1.6 days for controls). CONCLUSIONS: Low-energy cardioversion significantly decreased the amount of time cardiac surgery patients spent in AF after the operation. Larger studies are needed to determine whether this new treatment modality has the ability to decrease morbidity associated with postoperative AF and is cost-effective.
Aged↗
Results of endoaneurysmorrhaphy: does the location of the aneurysm matter?
Endoaneurysmorrhaphy is mostly performed on anterior-septal left ventricular (LV) aneurysms. It may also be applied to posterior aneurysms, which is technically more challenging. Whether the surgical risk is the same, irrespective of the location of the aneurysm, has not been studied before. We reviewed our experience with 158 patients (62+/-9 years, 72% male) undergoing endoaneurysmorrhaphy. Eleven patients (7%) had posterior LV aneurysms. Perioperative mortality was 5.7%. Of all preoperative and surgical variables tested, the presence of a posterior LV aneurysm (p=0.017), concomitant mitral valve surgery (p=0.008) and duration of extracorporal circulation (p=0.001) were significantly associated with higher perioperative mortality. However, patients with posterior LV aneurysms had more severe heart failure (p=0.0061) and a higher LV end diastolic volume index (138+/-38 vs. 102+/-41 ml/kg body weight; p=0.040) than patients with antero-septal LV aneurysms. Further studies are needed to determine whether the location of the aneurysm is a risk factor for mortality irrespective of the clinical presentation.
Aged↗
Intramyocardial partial oxygen pressure in patients undergoing transmyocardial laser revascularization and bypass surgery.
OBJECTIVE: Numerous investigations could not clarify the exact mechanism of transmyocardial laser revascularization (TMLR). The aim of this study was to investigate, whether TMLR leads to an increase of myocardial oxygenation in comparison to patients undergoing coronary artery bypass grafting (CABG). DESIGN: Twelve patients (TMLR group) underwent TMLR alone with an 800 W CO2 laser through a left anterior thoracotomy. Seventeen patients (CABG group) underwent standard CABG. Myocardial oxygenation was determined by measuring intramyocardial partial oxygen pressure (ptiO2 ). PtiO2 was measured online and mean values at 1, 24, 32, and 48 h postoperatively were compared with baseline before intervention. Parameters influencing ptiO2 (arterial pO2, hemodynamic parameters, hemoglobin) were recorded. RESULTS: Mean baseline ptiO2 was significantly lower in the TMLR group compared with the CABG group (p < 0.05). In both groups ptiO2 increased significantly in the postoperative course, whereby ptiO2 in the TMLR group was significantly lower compared with the CABG group. CONCLUSION: Although the exact mechanism of action of TMLR remains unclear, ptiO2 and thus oxygen supply in the myocardium increased in patients undergoing TMLR at least in the early postoperative course. However, ptiO2 increased to a lesser extent compared with CABG.
Aged↗
Histopathological grading of ascending aortic aneurysm: comparison of patients with bicuspid versus tricuspid aortic valve.
BACKGROUND AND AIMS OF THE STUDY: Bicuspid aortic valve (BAV) is a common inherited condition that is often accompanied by ascending aortic aneurysm. A high level of histological wall abnormalities was reported to be present in non-dilated aortas of patients with BAV. In patients with tricuspid aortic valve, there appears to exist a direct relationship between the diameter of the ascending aorta and degree of histopathological aortic wall abnormalities. Whether this situation exists in patients with BAV has not yet been investigated. METHODS: Surgical and medical records of all patients undergoing surgery of the ascending aorta were reviewed. A total of 65 patients was identified in whom an aortic wall specimen was obtained intraoperatively. These specimens were systematically re-evaluated, and graded according to the severity of seven histopathological conditions: fibrosis, atherosclerosis, medionecrosis, cystic medial necrosis, smooth muscle cell orientation, elastic fiber fragmentation, and inflammation. RESULTS: BAVs were present in 26 patients (40%). Patients with BAV had significantly less aortic wall alterations than patients with tricuspid aortic valves (p < 0.001) in all variables examined. The severity of aortic wall abnormalities was significantly dependent on aortic diameter in patients with BAV as well as tricuspid aortic valve (p = 0.036 and 0.019), but dependent on age (p = 0.009) only in patients with tricuspid aortic valve. CONCLUSION: The study results provide evidence that ascending aortic aneurysm in patients with BAV differs clinically and histologically from that in patients with tricuspid aortic valve. Further studies are needed to elucidate the impact of inherited and acquired aortic wall abnormalities on the development of aneurysms.
Adult↗