[Why should carotid artery restoration be carried out in acute occlusion of the internal carotid artery].
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OBJECTIVE: Valve-preserving root replacement has become an accepted alternative to composite replacement both in dissection and in aneurysmal disease. We retrospectively analysed 5-year results comparing root remodelling and reimplantation procedures. METHODS: From October 1995 to January 2001, 119 patients underwent either root remodelling (group A; n = 98; age: 61 +/- 14 years) or valve reimplantation within a vascular graft (group B; n = 21; age: 47 +/- 17 years). In group A, 26 patients were operated for aortic dissection type A and 72 for aortic valve regurgitation and aneurysmal disease. In group B, 8 patients were operated for aortic dissection type A, 13 for aortic valve regurgitation and aneurysm. Concomitant arch surgery was performed in 65 patients (group A: 57; group B: 8). RESULTS: Time on cardiopulmonary bypass was 121 +/- 30 min in group A, 143 +/- 24 min in group B, and aortic cross-clamp time was 87 +/- 19 min in group A and 113 +/- 24 min in group B. Average duration was therefore longer in group B (p = n.s.) Hospital mortality was 3.1 % in group A and 0 % in group B. Following elective procedures, hospital mortality was 1.1 % in group A. Freedom from aortic regurgitation over grade 2 at 4 years was 86 % in group A and 94.7 % in group B. At 4 years, freedom from proximal reoperation was 97.8 % in group A and 100 % in group B. There was no deterioration of valve function or need for reoperation observed after 1 year in either group. CONCLUSION: Five-year results are comparable and encouraging for remodelling and reimplantation procedures. If the initial valve function and geometry is adequate, the chance of secondary failure beyond the first year is minimal.
An active involvement of blood-brain barrier endothelial cell basement membranes in development of inflammatory lesions in the central nervous system (CNS) has not been considered to date. Here we investigated the molecular composition and possible function of the extracellular matrix encountered by extravasating T lymphocytes during experimental autoimmune encephalomyelitis (EAE). Endothelial basement membranes contained laminin 8 (alpha4beta1gamma1) and/or 10 (alpha5beta1gamma1) and their expression was influenced by proinflammatory cytokines or angiostatic agents. T cells emigrating into the CNS during EAE encountered two biochemically distinct basement membranes, the endothelial (containing laminins 8 and 10) and the parenchymal (containing laminins 1 and 2) basement membranes. However, inflammatory cuffs occurred exclusively around endothelial basement membranes containing laminin 8, whereas in the presence of laminin 10 no infiltration was detectable. In vitro assays using encephalitogenic T cell lines revealed adhesion to laminins 8 and 10, whereas binding to laminins 1 and 2 could not be induced. Downregulation of integrin alpha6 on cerebral endothelium at sites of T cell infiltration, plus a high turnover of laminin 8 at these sites, suggested two possible roles for laminin 8 in the endothelial basement membrane: one at the level of the endothelial cells resulting in reduced adhesion and, thereby, increased penetrability of the monolayer; and secondly at the level of the T cells providing direct signals to the transmigrating cells.
Regulated adhesion of leukocytes to the extracellular matrix is essential for transmigration of blood vessels and subsequent migration into the stroma of inflamed tissues. Although beta(2)-integrins play an indisputable role in adhesion of polymorphonuclear granulocytes (PMN) to endothelium, we show here that beta(1)- and beta(3)-integrins but not beta(2)-integrin are essential for the adhesion to and migration on extracellular matrix molecules of the endothelial cell basement membrane and subjacent interstitial matrix. Mouse wild type and beta(2)-integrin null PMN and the progranulocytic cell line 32DC13 were employed in in vitro adhesion and migration assays using extracellular matrix molecules expressed at sites of extravasation in vivo, in particular the endothelial cell laminins 8 and 10. Wild type and beta(2)-integrin null PMN showed the same pattern of ECM binding, indicating that beta(2)-integrins do not mediate specific adhesion of PMN to the extracellular matrix molecules tested; binding was observed to the interstitial matrix molecules, fibronectin and vitronectin, via integrins alpha(5)beta(1) and alpha(v)beta(3), respectively; to laminin 10 via alpha(6)beta(1); but not to laminins 1, 2, and 8, collagen type I and IV, perlecan, or tenascin-C. PMN binding to laminins 1, 2, and 8 could not be induced despite surface expression of functionally active integrin alpha(6)beta(1), a major laminin receptor, demonstrating that expression of alpha(6)beta(1) alone is insufficient for ligand binding and suggesting the involvement of accessory factors. Nevertheless, laminins 1, 8, and 10 supported PMN migration, indicating that differential cellular signaling via laminins is independent of the extent of adhesion. The data demonstrate that adhesive and nonadhesive interactions with components of the endothelial cell basement membrane and subjacent interstitium play decisive roles in controlling PMN movement into sites of inflammation and illustrate that beta(2)-integrins are not essential for such interactions.
BACKGROUND: The T-graft procedure achieves complete arterial revascularization in coronary three-vessel disease. In this technique, all bypass anastomoses are supplied by the left internal mammary artery (IMA). This prospective study explores the question of whether the quantitative flow in such grafts is influenced by the pathology in the native coronary arteries. METHODS: Eighty-two patients with coronary three-vessel disease were studied after complete arterial coronary revascularization with T-grafts. Quantitative flow and coronary flow reserve were measured in the proximal IMA with a Doppler guide wire. Three groups were compared: group 1, all native coronary arteries were stenosed but patent (n = 31); group 2, one occluded native coronary vessel (n = 33); group 3, two or more occluded native coronary arteries (n = 18). RESULTS: Quantitative flow was significantly higher in group 3 than in group 2 at 1 week (93.9 +/- 39.5 vs 75.8 +/- 27.3 mL/min, p < 0.05) and 6 months postoperatively (86.0 +/- 40.1 vs. 69.1 +/- 35.5 mL/min, p < 0.05). Flow in group 2 was significantly (p < 0.05) higher than in group 1 (1 week: 58.0 +/- 28.4 mL/min, 6 months: 55.2 +/- 29.2 mL/min) in both examinations. There were no significant differences in coronary flow reserve between the three groups (1: 2.88 +/- 0.97, 2: 2.84 +/- 0.96, 3: 2.74 +/- 0.94). CONCLUSIONS: After complete arterial revascularization with T-grafts, the quantitative flow in the IMA is influenced by the status of the native coronary arteries. As a result of competitive flow phenomena, blood flow in the bypasses is significantly lower when the coronary arteries are affected only by stenosis.
We report two cases of patients with left internal mammary artery (LIMA) grafts impaired by proximal stenosis of the subclavian artery. The functional impact of the subclavian lesions was investigated using flow-wire. The hemodynamic relevance of the lesions could be documented with the functional flow measurements in both instances. The relevance of preoperative evaluation of the subclavian artery is emphasized when it is planned to use the LIMA as coronary bypass. Moreover, the case reports indicate that percutaneous intervention of the subclavian artery is an effective treatment modality to restore adequate flow in the LIMA.
OBJECTIVE: Pulmonary thromboendarterectomy (PTE) for chronic thromboembolic pulmonary hypertension is a challenging procedure with a considerable mortality. The aim of this investigation was to identify risk factors influencing mortality and operative results. METHODS: Between October 1995 and August 2000, 69 patients (age 54 years; 34 women; mean New York Heart Association (NYHA) stage 3.4) underwent PTE. The preoperative pulmonary vascular resistance (PVR) was 988+/-554 dynes x s x cm(-5), mean pulmonary artery pressure 50+/-12 mmHg, right atrial pressure (RAP) 11.5+/-4 mmHg. Hospital mortality was 10.1% (n=7/69). Mean postoperative PVR on the 2nd day was 324+/-188 dynes x s x cm(-5). Pulmonary angiography was reviewed for number of involved segments (mean 9.3+/-2) and bronchial arteries diameter (BAD; mean 4.6+/-1.6 mm). A univariate and multivariate analysis was performed to determine preoperative risk factors for hospital death and inadequate hemodynamic improvement. RESULTS: By univariate analysis, mortality was influenced by age (P=0.04), right atrial pressure (P=0.009), NYHA (P=0.02) and the number of angiographically involved segments (P=0.02). Sex, left ventricular function, presence of coronary artery disease and bronchial artery diameter did not show correlation with mortality. Inadequate hemodynamic improvement in a dichotomized analysis (PVR > or =500 dynes x s x cm(-5), n=11, and PVR < 500 dynes x s x cm(-5), n=58), assessed by univariate analysis, was significantly influenced by age (P=0.02), preoperative PVR (P=0.01), NYHA (P=0.002), RAP (P=0.02) and female sex (P=0.02). Multivariate analysis identified age (P=0.1), RAP (P=0.002) and female sex (P=0.007) as risk factors for inferior hemodynamic improvement. CONCLUSIONS: Preoperative parameters can be utilized to assess postoperative mortality and hemodynamic improvement after pulmonary thromboendarterectomy. Patient age and clinical deterioration of pulmonary hypertension are considerable preoperative factors influencing hospital mortality. Inadequate postoperative hemodynamic improvement is affected by severity of disease and female sex.
OBJECTIVE: Arterial revascularization with either internal thoracic artery (ITA) or radial artery (RA) appears to be particularly attractive in diabetic patients. Previous investigations have shown that endothelial dysfunction and artherosclerosis are seen more often in these patients. The aim of this study was to compare the vasoreactive properties of ITA and RA grafts in diabetic and non-diabetic patients. METHODS: Arterial rings were harvested from 57 patients who underwent complete arterial revascularization. The patients were divided into a non-diabetic group (I: n = 30) and patients with diabetes mellitus (II: n = 27). Arterial rings of the ITA (I: n = 30; II: n = 27) and RA (I: n = 28; II: n = 19) were mounted on a strain gauge in oxygenated, normothermic Krebs's--Henseleit solution at optimal resting tension. With KCL (80 mM) serving as the control, assessment of force of contraction (norepinephrine), endothelium-dependent relaxation (acetylcholine) and smooth muscle-dependent relaxation (glyceroltrinitrate) were obtained. RESULTS: After KCL, the RA showed a trend to lower maximum contraction forces in diabetics (I: 76 +/- 25 mN; II: 69 +/- 29 mN), which was pronounced in patients with diabetes of more than 10 years duration (55 +/- 23 mN; P = 0.1). Maximum contraction force of the ITA was similar in both groups (I: 41 +/- 20 mN; II: 34 +/- 19 mN) and not influenced by the duration of diabetes. The two groups showed no significant differences of the relative vasoconstriction after norepinephrine in RA (I: 53 +/- 18%; II: 61 +/- 19%) and ITA rings (I: 70 +/- 23%; II: 69 +/- 25%). Also, endothelium-dependent relaxation with acetylcholine in RA (I: 53 +/- 14%; II: 57 +/- 16%) and ITA rings (I: 42 +/- 17%; II: 44 +/- 20%), and smooth muscle relaxation with glyceroltrinitrate of RA (I: 72 +/- 8%; II: 73 +/- 12%) and ITA rings (I: 64 +/- 12%; II: 58 +/- 20%) was comparable in both groups. No influence of duration of the diabetic disease was noted. CONCLUSIONS: Although RA rings of patients with a long duration of diabetes have decreased maximum contraction forces, their relative vasoconstriction after norepinephrine, endothelium-dependent relaxation and smooth muscle relaxation was similar to non-diabetic patients. We thus conclude that the RA is an adequate arterial conduit in the patient with diabetes mellitus.
Perioperative acute right heart failure after orthotopic heart transplantation contributes significantly to morbidity and mortality. Vasodilators administered intravenously may decrease pulmonary vascular resistance, but also affect systemic circulation. A decrease of mean arterial pressure will result in reduced right coronary blood flow and deterioration of right ventricular performance. Vasodilators administered by inhalation, i.e. nitric oxide and prostacyclin, are attractive due to a more selective effect on the pulmonary circulation. This is the first report on the use of aerosolized iloprost, a long-acting prostacyclin analogue, applied for treatment of postoperative right heart failure in cardiac transplantation. After uneventful surgery, a heart transplant recipient was extubated on the first postoperative day and exhibited right heart failure on the following day. Standard treatment did not resolve this clinical problem sufficiently. A trial with inhalation of iloprost (16 microg per inhalation cycle, applied six times per day) was initiated. Iloprost inhalation resulted in a sufficient decrease of pulmonary vascular resistance (-23.5%), while cardiac index (+24.0%) and mixed venous saturation (+9.0%) increased. No profound effect on the systemic vascular resistance was observed (-2.8%). Iloprost inhalation may be an effective alternative to nitric oxide in the intensive care management of acute right heart failure after orthotopic heart transplantation. Due to the prolonged effect on the pulmonary vascular resistance, iloprost is especially useful for extubated patients.
BACKGROUND: The T-graft procedure achieves complete arterial coronary revascularization with only two conduits. In this technique, all the bypass anastomoses are supplied by the left internal mammary artery (IMA). Changes in flow conditions or flow redistribution in the subclavian artery may thus sigificantly influence coronary perfusion. The objective of this study was to determine whether changes in blood flow in the subclavian artery affect the flow in IMA grafts in patients who have undergone complete arterial revascularization with T-grafts. METHODS: Quantitative flow volume and flow profiles in the IMA graft and the proximal subclavian artery were measured with a flow-wire in 20 patients one week postoperatively. Following baseline measurements, brachial artery constriction was achieved by applying a blood pressure measurement cuff to the patient's left upper arm. After 5 minutes, quantitative flow in the IMA and in the proximal subclavian artery was assessed. The cuff was then released and the measurements repeated. RESULTS: Flow in the subclavian artery changed significantly (p < 0.01) from baseline (355.4 +/- 95.2 ml/ min) to constriction (171.2 +/- 61.3 ml/min) and hyperemia (679.3 +/- 195.1 ml/min). Flow in the IMA graft remained constant irrespective of subclavian artery flow (75.4 +/- 26.2 ml/min vs. 78.0 +/- 28.9 ml/min vs. 75.5 +/- 29.3 ml/min, respectively). The flow profile in the IMA was similarily unchanged. CONCLUSION: In patients in whom the coronary bypass blood flow is dependent on the left IMA, neither the quantitative flow volume nor the flow profile are altered by changes in blood flow of the subclavian artery.
BACKGROUND: In aortic valve replacement stentless bioprostheses results in improved hemodynamic function compared to stented valves. Using the root replacement technique even larger prostheses are implantable. We present our experience with stentless bioprostheses implanted in the "full-root" technique. PATIENTS AND METHODS: Between 01/1997 and 12/2000, 149 patients underwent root replacement with a stentless xenograft (age 70 +/- 9y, women 52 %, ejection-fraction 58 +/- 15 %). Isolated stenosis was present in 34 %, incompetence in 24 %, and mixed disease in 42 % of patients. Bacterial endocarditis was found in 16 %, and 3 patients suffered from acute aortic dissection. RESULTS: Mean bypass time was 118 +/- 45 min, ischemic time 83 +/- 26 min and operating time 201 +/- 62 min. Concomitant procedures were CABG (32 %), replacement of ascending aorta (22 %) and aortic arch (13 %), mitral valve repair (6.7 %), and carotid thrombendarterectomy (1.3 %). Total in-hospital mortality was 6.7 %, with a 1.8 % mortality rate for patients with isolated aortic valve disease. CONCLUSION: Aortic valve replacement using stentless bioprostheses in the root replacement technique is a safe surgical option. In patients with small aortic roots or ring abscesses it guarantees remodelling of the aortic annulus.
BACKGROUND: Coronary artery bypass grafting (CABG) using left internal thoracic artery and vein grafts is standard in patients of advanced age. A number of these patients, however, present without suitable vein grafting material and thus require the use of arterial conduits. In order to investigate the safety and efficacy of complete arterial revascularisation, we have compared the perioperative results of patients older than 70 years with conventional CABG and complete arterial revascularisation. PATIENTS AND METHODS: Group I (n = 172) with conventional CABG in 1999 was compared with 152 patients (group II) with complete arterial CABG between 1996 and July 2000. There were no significant differences regarding age, gender, left ventricular ejection fraction or incidence of three-vessel disease or left main stenosis. The proportion of reoperations was significantly higher in group II (16 %) vs. group I (4 %). RESULTS: A mean of 3.7 +/- 0.7 anastomoses (I) versus 4.0 +/- 0.9 (II) were performed per patient (p = n. s.). Mean operating time (I: 210 +/- 46 min; II: 194 +/- 46 min) and bypass time (I: 87 +/- 25 min; II: 78 +/- 29 min) were significantly lower in group II. Ischemic time (I: 46 +/- 22 min; II: 49 +/- 21 min) was not significantly different. The incidence of sternal dehiscence was 2.9 % (I: n = 5) vs. 1.3 % (II: n = 2). Hospital mortality was 4.6 % in group I vs. 3.9 % (II). CONCLUSION: Complete arterial revascularisation is a safe option in patients aged over 70. It remains to be shown whether it may also have advantage in the long term.
BACKGROUND: The prognostic benefit of arterial grafts appears to be particularly high in patients with diabetes mellitus, but has been limited by availability of grafts and sternal complications. Complete arterial coronary artery bypass grafting (caCABG) using skeletonized grafts, radial arteries (RA) and the T-graft approach may reduce the perioperative risk particularly in the diabetic patient. METHODS: The perioperative data of 174 diabetic (group I) and 402 non-diabetic patients (group II) who underwent caCABG were studied retrospectively. The operations were performed using bilateral internal thoracic arteries (ITA) (I: 20%; II: 21%; ns) or ITA and RA (I: 80%; II: 79%; ns). Diabetic patients presented with a higher incidence of 3-vessel disease (I: 93%; II: 83%; p<0.05) and a lower left ventricular ejection fraction (I: 55+/-16%; 11:60+/-16%; p<0.05). RESULTS: No differences were found regarding need of intraaortic balloon pump (I: 1.7%; II: 2.7%; ns), incidence of myocardial infarction (I: 1.2%; II: 1.7%; ns) and sternal complications (I: 2.3%; II: 1.0%; ns). In-hospital mortality was 1.7%(I) versus 2.2% (II) (p = ns). CONCLUSIONS: Using skeletonized arterial grafts and the T-graft approach, caCABG in diabetic patients is as safe as in non-diabetics. With the RA as a second graft, bilateral ITA harvesting is avoidable.
OBJECTIVE: Valve-preserving aortic replacement has evolved into an accepted therapeutic option for aortic ectasia with morphologically intact leaflets. Some patients, however, exhibit additional leaflet prolapse. We compared the results of established valve-preserving techniques with those of the combination of valve-preserving aortic surgery and additional repair of leaflet prolapse. METHODS: Between October 1995 and March 2000, 99 patients underwent valve-preserving root replacement by means of root remodeling or valve reimplantation for acute dissection (n = 25), chronic dissection (n = 4), or aneurysm (n = 70). In group A (63 patients) either root remodeling (n = 49) or valve reimplantation (n = 14) was performed with a standard technique. In group B (36 patients) valvepreserving aortic replacement (remodeling, n = 31; reimplantation, n = 5) was combined with repair of leaflet prolapse in the presence of bicuspid (n = 24) or tricuspid (n = 12) valve anatomy. Additional replacement of the aortic arch was required more frequently in group A (group A, n = 43; group B, n = 14; P =.006); otherwise, the groups were comparable. RESULTS: Cardiopulmonary bypass (group A, 133 +/- 31 minutes; group B, 117 +/- 30 minutes; P =.006) and myocardial ischemia times (group A, 96 +/- 25 minutes; group B, 88 +/- 20 minutes; P =.05) were significantly longer in group A. Mortality was not significantly different between groups (group A, 4.8%; group B, 0%). One patient in each group underwent secondary valve replacement, and all other patients had stable valve function. Freedom from aortic regurgitation of grade 2 or greater after 48 months was 93.0% in both groups. CONCLUSION: Repair of leaflet prolapse in conjunction with valve-preserving root replacement leads to midterm results that are equal to those of valve-preserving root replacement for morphologically intact leaflets.
BACKGROUND: Complete arterial CABG is a surgical option to improve long-term results in the treatment of coronary artery disease (CAD). Harvesting of multiple arterial grafts is commonly associated with prolonged operating times and increased trauma. By use of new operative techniques (skeletonized grafts and the T-graft approach), CABG in multivessel CAD is now possible with only 2 grafts. We present our experience in the use of these techniques on a routine basis. METHODS AND RESULTS: Between March 1996 and September 1999, 490 patients (aged 61+/-9 years, 20% female) underwent complete arterial CABG. Left ventricular ejection fraction ranged from 15% to 85% (mean 59+/-15%). Triple-vessel disease was present in 88% of the patients. The incidence of diabetes mellitus was 32% (14% insulin dependent). Either both internal thoracic arteries (ITAs) (23%) or the left ITA and radial artery (77%) were used as conduits. In 85% of the patients, a T graft was created. Mean operating time was 198+/-46 minutes; bypass time, 82+/-25 minutes; and ischemic time, 58+/-22 minutes. Two to 7 (mean 4.1+/-0.9) anastomoses were performed per patient. Perioperative intra-aortic balloon pump was necessary in 12 patients (2.4%). The rate of perioperative myocardial infarction was 1.2%. Sternal complications occurred in 1. 0%, and in-hospital mortality was 2.2%. Postoperative coronary angiography in 172 patients (35%) documented excellent patency rates (left ITA 98.3%, right ITA 96.5%, and radial artery 96.6%). CONCLUSIONS: Complete arterial revascularization in multivessel CAD is possible with the use of only 2 grafts with good perioperative results. This approach allows for complete arterial CABG on a routine basis.
The free flow of skeletonized ITA grafts was compared with that of pedicled ITA grafts. One hundred patients with coronary artery diseases underwent elective CABG. In the group I (n = 50), the left ITA was dissected using the skeletonization technique. In the group II (n = 50), the ITA was harvested as a pedicled graft. Free flow of the ITA was recorded before and 15 min after intraluminal application of diluted papaverine. Mean arterial pressure was maintained at 9.31 kPa (70 mmHg). The results showed that before the application of papaverine, free flow of skeletonized and pedicled ITA grafts was identical between the two groups. After treatment with papaverine, the maximum free flow was significantly higher in the skeletonized ITA's in the group I (199.3 +/- 69.6 ml/min) than in the group II (145.7 +/- 70.3 ml/min, P < 0.05). There was on significant difference between the free flow after dilatation of the left and right ITA in the group I (left 199.3 +/- 69.6 ml/min, right 198.9 +/- 61.8 ml/min, respectively). It was concluded that preparation of the ITA with the skeletonization technique resulted in significantly higher free flow capacity than in pedicled grafts and would improve the results of arterial revascularization. The complication rate seems to be lower than with the conventional method.
On the first day after an uneventful emergence caesarean section a 36-year-old woman developed circulatory collapse requiring cardiopulmonary resuscitation for 15 minutes. After resuscitation the patient remained haemodynamically unstable and was clinically highly suspected to suffer from fulminant pulmonary embolism. In this situation the physicians caring for the patient decided to perform a surgical pulmonary embolectomy without previous diagnostic workup. Massive emboli were removed from both pulmonary arteries. Postoperatively the patient recovered and was transferred to a rehabilitation center without severe cerebral sequelae.
Reconstruction of a regurgitant bicuspid aortic valve is a new alternative to aortic valve replacement. With concomitant aortic root dilatation adequate reconstruction is feasible by valve-sparing aortic replacement. Between 10/95 and 02/00, 30 patients underwent reconstruction of a regurgitant bicuspid aortic valve. Additional aortic replacement was performed in 23 cases. Valve reconstruction was performed by plication of the prolapsing leaflet. No patient died peri- or postoperatively. Freedom from aortic valve regurgitation > or = II as well as freedom from reoperation were 100% after 48 months. Reconstruction of a regurgitant bicuspid aortic valve is feasible with encouraging mid-term results. With concomitant dilatation of the ascending aorta, a combination of aortic replacement and valve reconstruction can achieve stable results even in bicuspid valve anatomy.