Biomedical subjects

H Oelert

Publications and source records attributed to H Oelert.

At least 73 records · Page 4Linked to original sources

PubMed1998

Early failure of an autologous pericardium aortic heart valve (ATCV) prosthesis.

BACKGROUND AND AIMS OF THE STUDY: The risk of reoperation due to calcific degeneration is the most important drawback of biological heart valves compared with mechanical prostheses. Concepts to mitigate calcification have been tested experimentally and clinically, but none has proven completely to prevent degeneration. METHODS: Renewed interest has involved the use of autologous pericardium for intraoperative construction of autologous aortic valves (ATCV). RESULTS: Of 10 ATCV implanted between 1994 and 1996, one was removed from an 84-year-old female 27 months after implantation because of severe valvular insufficiency. Eight months earlier, a broken spring of the stent system was detected radiographically, with normal valvular competence at echocardiography. Valve dysfunction was due to shrinkage of one leaflet. Measurement of tissue calcium by atomic absorption spectroscopy showed high levels in the shrunken leaflet compared with two intact leaflets (42.82 versus 0.51 and 2.42 mg Ca2+/g). Histology and immunohistology demonstrated extensive fiber degeneration without inflammation or immune reactions in the destroyed leaflet, and moderate fiber degeneration in intact leaflets. Scanning electron microscopy showed smooth surfaces in the normal leaflet and exposure of collagen in the degenerated leaflet in association with calcium deposition. CONCLUSIONS: In contrast to the outcome in animal studies, intraoperative tanning did not prevent tissue shrinkage in this case. Leaflet malfunction was associated with calcification. At present, the clinical use of valves constructed from autologous pericardium can not be recommended.

Aged↗

PubMed1998

Determinants of calcium uptake of bovine pericardium for heart valve replacement: results of in vitro studies.

BACKGROUND AND AIMS OF THE STUDY: Reduction of biomaterial calcification is an important aim in the basic research of biological heart valves. An in vitro model was used to investigate the influence of serum calcium concentration and surface coverage with cells or basal proteins on calcium uptake of bovine pericardium. METHODS: Samples of glutaraldehyde-tanned bovine pericardium, stored in formaldehyde and detoxified with borohydride were incubated for two weeks with cell culture medium containing low (1.0 mmol/l) or physiologic (2.3 mmol Ca/l) calcium concentration. Specimens were either unseeded, completely surface-covered with rat fibrocytes (rf) or fibrin (fi), or incompletely seeded with rabbit cells (re). Quality of surface coverage was assessed by surface scanning electron microscopy and calcium content by atomic absorption spectroscopy. RESULTS: Serum calcium had a significant influence on calcium uptake (low versus physiological (1.58 +/- 2.45 mg/g versus 8.10 +/- 1.73 mg/g wet wt, p < 0.001). This may explain early calcification of bioimplants in children and patients on dialysis. Surface coverage significantly reduces calcium uptake (fi, 1.20 +/- 0.41 mg/g, rf, 4.20 +/- 1.70 mg/g, p < 0.001) but complete coverage is necessary (re, 6.98 +/- 1.64 mg/g, NS). CONCLUSIONS: In vitro testing of calcium uptake has proven to be a valuable tool for evaluation of biomaterial calcification.

Animals↗

PubMed1998

In vitro effects of anticalcification treatment on the calcium uptake of bioprosthetic materials.

BACKGROUND AND AIM OF THE STUDY: The frequent need for re-replacement of tissue valves due to calcification remains their major disadvantage compared with mechanical implants. A variety of anticalcification treatments has been proposed but none has proved to prevent calcific degeneration. The study aim was to evaluate, in vitro, the time course of calcium uptake of procine and bovine biomaterials and the efficacy of anticalcification treatments. METHODS: Samples of glutaraldehyde-tanned biomaterials with (Carpentier-Edwards, Medtronic Intact, Hancock II, MZGTB) or without anticalcification treatment (Mitroflow) were incubated with culture medium containing physiological calcium levels. Specimens were then analyzed at two, four or eight weeks for their calcium content (mg/g wet weight). RESULTS: All specimens calcified over time, though the time courses for each were significantly different. Mitroflow and Intact valves accumulated high calcium levels rapidly during the first two weeks, with small further increases thereafter. Anticalcification treatment reduced calcium uptake of Carpentier-Edwards material during the first two weeks of incubation, but the material gradually attained comparable calcium levels at eight weeks. Hancock valves and the self-customized MZGTB valve showed the lowest calcium levels over the test period. CONCLUSIONS: This in vitro study documented major differences in calcium uptake of different biomaterials. Some anticalcification treatments render the material temporarily less susceptible to calcium binding but none can prevent calcification. In vitro testing has proved to be a valuable instrument for evaluating anticalcification treatments, but should be combined with evaluation of bioprosthesis surface interaction with circulating blood.

Animals↗

PubMed1998

Blocking of classical complement pathway inhibits endothelial adhesion molecule expression and preserves ischemic myocardium from reperfusion injury.

Myocardial injury after ischemia (I) and reperfusion (R) is related to leukocyte activation with subsequent release of cytokines and oxygen-derived free radicals as well as complement activation. In our study, the cardioprotective effects of exogenous C1 esterase inhibitor (C1 INH) were examined in a rat model of myocardial I + R (i.e., 20 min + 24 hr or 48 hr). The C1 INH (10, 50 and 100 U/kg) administered 2 min before reperfusion significantly attenuated myocardial injury after 24 hr of R compared to vehicle treated rats (P < .001). Further, cardiac myeloperoxidase activity (i.e., a marker of PMN [polymorphonuclear leukocyte] accumulation) in the ischemic area was significantly reduced after C1 INH treatment compared to vehicle treated animals (0.81 +/- 0.1, 0.34 +/- 0.13, 0.13 +/- 0.1 vs. 1.44 +/- 0.3 U/100 mg tissue, P < .001). In addition, C1 INH (100 U/kg) significantly attenuated myocardial injury and neutrophil infiltration even after 48 hr of reperfusion compared to vehicle treatment. Immunohistochemical analysis of ischemic-reperfused myocardial tissue demonstrated activation of classical complement pathway by deposition of C1q on cardiac myocytes and cardiac vessels. In addition, expression of the endothelial adhesion molecules P-selectin and intercellular adhesion molecule 1 (ICAM-1) was observed after reperfusion of the ischemic myocardium. In this regard, C1 INH administration abolished expression of P-selectin and ICAM-1 on the cardiac vasculature after myocardial ischemia and reperfusion. Blocking the classical complement pathway by exogenous C1 INH appears to be an effective means to preserve ischemic myocardium from injury after 24 and 48 hr of reperfusion. The mechanisms of this cardioprotective effect appears to be due to blocking of complement activation and reduced endothelial adhesion molecule expression with subsequent reduced PMN-endothelium interaction, resulting in diminished cardiac necrosis.

Animals↗

PubMed1998

[Value of molecular markers for administration of anticoagulant therapy after heart valve replacement].

In a prospective study, 39 patients following aortic or mitral valve replacement underwent investigation of molecular markers (prothrombin fragment F1+2, Factor II) in the initial phase of oral anticoagulation therapy (OAT). The results demonstrate that, despite INR being in the depicted range, the levels of the molecular markers remained high, indicating an increased risk of thromboembolic events. This leads to the conclusion that molecular markers are superior to INR in the monitoring of the early phase of OAT.

Anticoagulants↗

PubMed1998

Clinical performance of the native pulmonary valve in the systemic circulation.

BACKGROUND AND AIM OF THE STUDY: In a number of corrective and palliative procedures the autologous pulmonary valve is used as the systemic semilunar valve. This study reviews the surgical results and function of the native pulmonary valve in the systemic position after various surgical procedures. METHODS: Between January 1994 and December 1997, the autologous pulmonary valve was transferred functionally or anatomically into the systemic circulation in 89 patients. Follow up echocardiograms and cardiac angiograms were reviewed for 51 neonates with transposition of the great arteries after an arterial switch operation (ASO), in 21 patients after first-stage palliation of hypoplastic left heart syndrome (HLHS), in eight children and adults with pulmonary autograft aortic valve replacement (Ross procedure), and in nine patients with a pulmonary artery-to-aortic anastomosis (Damus-Kaye-Stansel (DKS) procedure) in complex heart defects with outflow obstruction. RESULTS: Nine patients (five with HLHS) died; thus, overall mortality rate was 10.2%. There was no evidence of valve-related mortality. Trivial insufficiency following ASO was noted in 11 patients, with no progression of incompetence over time. None of the HLHS patients had pulmonary insufficiency preoperatively, but all showed mild regurgitation on postoperative echocardiography. There was a moderate increase in insufficiency which was attenuated after an early second-stage palliation. Three of nine patients undergoing a DKS anastomosis demonstrated a hemodynamically insignificant insufficiency. Modification of the surgical technique avoided postoperative regurgitation. Four of seven patients having a Ross procedure showed trivial but non-progressive neoaortic regurgitation. CONCLUSIONS: Based on this experience, the autologous pulmonary valve performs adequately at intermediate term follow up. Postoperatively, trivial regurgitation was a frequent finding but was hemodynamically insignificant. Progression or late development of insufficiency as well as stenosis were rare problems.

Adolescent↗

PubMed1998

[Short distal venous bypass for saving the extremity diabetic foot].

If inflow to the distal superficial or popliteal artery is not compromised in diabetic patients with critical leg ischemia short distal vein bypass grafts can be constructed to tibial or foot arteries. By restoration of foot perfusion, durable limb salvage with only minor tissue loss can be achieved in most patients. Postoperative progression of inflow artery disease is uncommon.

Aged↗

PubMed1997

[Early results of pulmonary thromboendarterectomy in chronic thromboembolic pulmonary hypertension].

Pulmonary thromboendarterectomy (PTE) is a potentially curative procedure in chronic thromboembolic pulmonary hypertension. From June, 1989, to December, 1994, we performed PTE in 109 consecutive patients. Multiple changes in surgical approach and postoperative management have been implemented since January, 1995. We report the early results of 32 thromboendarterectomies performed from January, 1995, to January, 1997. Thirty-two patients (16 females, 16 males; mean age 55 years) were operated using cardiopulmonary bypass, deep hypothermia and circulatory arrest. Preoperative NYHA functional class was III in 21 and IV in 11 patients. Pulmonary vascular resistance (PVR) and mean pulmonary artery pressure (mPAP) were elevated to 967 +/- 238 dynes.s.cm-5 and 51 +/- 11 mm Hg respectively. The perioperative mortality rate was 9.3% (3 of 32). Twenty-nine survivors were weaned from mechanical ventilation and extubated after a mean of 35 hours (12 to 190 hours). PVR was reduced to 301 +/- 151 dynes.s.cm-5 (p < 0.001) and mPAP was reduced to 28 +/- 10 mm Hg (p < 0.001). Pulmonary thromboendarterectomy is an effective surgical procedure for chronic thromboembolic pulmonary hypertension. By means of modifications in surgical approach and postoperative management, early results can be improved and perioperative mortality can be decreased to less than 10%.

Chronic Disease↗

PubMed1997

[Reversibility of changes in left and right ventricular geometry and hemodynamics in pulmonary hypertension. Echocardiographic characteristics before and after pulmonary thromboendarterectomy].

Pulmonary thromboendarterectomy (PTE) leads to an acute decrease of right ventricular (RV) afterload in patients with chronic thromboembolic pulmonary hypertension. We investigated the changes in right and left ventricular (LV) geometry and hemodynamics by means of transthoracic echocardiography. The prospective study was performed in 14 patients (8 female, 6 male; age 55 +/- 20 years) before and 18 +/- 12 days after PTE. Total pulmonary vascular resistance and systolic pulmonary artery pressure were significantly decreased (PVR: preoperative 986 +/- 318, postoperative 323 +/- 280 dyn x s/cm5, p < 0.05; PAP preoperative 71 +/- 40, postoperative 41 +/- 40 mm Hg + right atrial pressure, p < 0.05). End diastolic and end systolic RV area decreased from 33 +/- 12 to 23 +/- 8 cm2, respectively, from 26 +/- 10 to 16 +/- 6 cm2, p < 0.05. There was an increase in systolic RV fractional area change from 20 +/- 12 to 30 +/- 16%, p < 0.05. RV systolic pressure rise remained unchanged (516 +/- 166 vs. 556 +/- 128 mm Hg/sec). LV ejection fraction remained within normal ranges (64 +/- 16 vs. 62 +/- 12%). Echocardiographically determined cardiac index increased from 2.8 +/- 0.74 to 4.1 +/- 1.74 l/min/m2. A decrease in LV excentricity indices (end diastolic: 1.9 +/- 1 vs. 1.1 +/- 0.3, end systolic: 1.7 +/- 0.6 vs. 1.1 +/- 0.4, p < 0.05) proved a normalization of preoperatively altered septum motion. LV diastolic filling returned to normal limits: (E/A ratio: 0.62 +/- 0.34 vs. 1.3 +/- 0.8; p < 0.05); Peak E velocity: 0.51 +/- 0.34 vs. 0.88 +/- 0.28 m/sec, p < 0.05; Peak A velocity: 0.81 +/- 0.36 vs. 0.72 +/- 0.42 m/sec, ns; E deceleration velocity: 299 +/- 328 vs. 582 +/- 294 cm/sec2, p < 0.05; Isovolumic relaxation time: 134 +/- 40 vs. 83 +/- 38 m/sec, p < 0.05). We could show a marked decrease in RV afterload shortly after PTE with a profound recovery of right ventricular systolic function--even in case of severe pulmonary hypertension. A decrease in paradoxic motion of the interventricular septum and normalization of LV diastolic filling pattern resulted in a significant increase of cardiac index.

Aged↗

PubMed1997

[Surgical aspects of pulmonary thrombendarterectomy].

Pulmonary thromboendarterectomy is an accepted operative procedure for treatment of pulmonary hypertension due to chronic embolism. Despite its proven value this procedure has been established at very few centers worldwide. In this paper we report our actual operative concept and operative results. Between 8'89 and 4'96 127 patients were operated with use of extracorporeal circulation, deep hypothermia and circulatory arrest. After analysis of the initial high perioperative mortality (26%, 29/108) our operative and postoperative concept changed since 11'94: 1. central incision of both pulmonary arteries, 2. endarterectomy exclusively during circulatory arrest, 3. prolonged reperfusion to 37 degrees C, 4. pressure controlled ventilation, NO-inhalation, early extubation, and 5. modified vasopressor therapy. Preoperatively 12 of the 19 patients were in NYHA class III and 6 in class IV. Mean pulmonary artery pressure was 52(17) mmHg with a calculated pulmonary resistance of 1013(579) dynes.s.cm-5. Mean circulatory arrest time was 37 min (19-57 min) (bypass time 345 min, (240-430 min)). Perioperatively two patients (11%) died (multiorgan failure; rethrombosis of pulmonary artery/right heart failure), all other patients survived (89%). Perioperative complications included reversible renal failure, delirium and postcardiotomy syndrome (1/2/1). Mean pulmonary resistance was postoperatively significantly reduced (362(124) dynes.s.cm-5) (p < 0.01). Early results of pulmonary thromboendarterectomy can be improved by consequent modifications of the intra- and postoperative concept.

Adolescent↗

PubMed1997

[Thymectomy in myasthenia gravis].

Myasthenia gravis is a relatively uncommon autoimmune disorder of neuromuscular transmission. Surgical therapy plays an important role in addition to medical treatment. Follow-up results of 52 patients with thymectomy are presented. Between 1984-1996 thymectomy via median sternotomy was performed in 52 patients with myasthenia gravis (female = 28, male = 24). The score described by Ossermann and Genkins was used for classification. According to this classification, we found 12 patients in class II(I), 21 in class IIA, 17 in class IIB and 2 in class III, respectively. A thymoma was found in 19, follicular lymphoid hyperplasia in 24 and an atrophic thymus in 9 cases, respectively. There was no mortality. Severe postoperative complications consisted of bleeding and reoperation in one patient and another patient developed a sternal instability with consecutive operative refixation. Follow-up evaluation after a mean period of 36 months (min. 6 months, max. 130 months) revealed a relief of myasthenic symptoms in 37 patients. Thymectomy is effective in the treatment of myasthenia gravis with a low complication rate.

Adult↗

PubMed1996

[Thromboendarterectomy in chronic thromboembolic pulmonary hypertension. Hemodynamics and right-heart function over the long term].

OBJECTIVE: To find out whether pulmonary thromboendarterectomy (PTE) can achieve lasting reduction of pulmonary vascular resistance in patients with pulmonary arterial hypertension due to chronic thromboembolism. PATIENTS AND METHODS: 45 patients (25 women, 20 men; mean age 45 +/- 24 [19-67] years) were re-investigated a mean of 21 (13-32) months after successful PTE. Two patients had then been in New York Heart Association (NYHA) stage II, 26 in stage III, and 17 in stage IV. In addition to clinical examination and chest radiogram 36 patients had right heart catheterization, 28 pulmonary angiography and 44 echocardiography. RESULTS: Definite improvement of symptoms had occurred in all. 34 were now in NYHA stage I, nine in stage II, and two in stage III. The pulmonary vascular resistance was significantly lower than before and immediately after PTE (pre-PTE: 1052 +/- 472 dyn.s.cm-5; post-PTE: 293 +/- 175 dyn.s.cm-5; at follow-up: 187 +/- 92 dyn.s.cm-5; P < 0.001 for follow-up vs pre-PTE; P < 0.05 for follow-up vs post-PTE). Correspondingly, cardiac index had significantly increased (3.0 +/- 0.5 vs 2.0 +/- 0.7 l/min.m2; P < 0.001). Radiological and echocardiographic examinations showed a definite decrease in right ventricular dimensions and improvement in right ventricular function. CONCLUSION: In patients with pulmonary arterial hypertension due to chronic pulmonary thromboembolism PTE can achieve a reduction in pulmonary vascular resistance with lasting improvement in right heart function and clinical symptoms.

Adult↗

PubMed1996

Gradual angioplasty and stent implantation to treat complete superior vena cava occlusion after Mustard procedure.

A 16-year-old male was admitted with complete occlusion of the superior vena cava pathway 14 years after Mustard procedure for transposition of the great arteries. From a left subclavian vein approach, the atretic vein segment was perforated using a straight guidewire, and was followed by sequential balloon dilation. Implantation of a 30 mm Palmaz-stent through a femoral vein approach resulted in a widely patent channel of the vena cava superior into the systemic venous atrium.

Adolescent↗

PubMed1996

Quantification of mitral valve stenosis by three-dimensional transesophageal echocardiography.

The aim of this study was the evaluation of the diagnostic potentials of transesophageal 3D- echocardiography in the determination of mitral valve stenosis. 54 patients were investigated by transthoracic and multiplane transesophageal echocardiography. In 41 patients cardiac catheterization was performed. 3D- echocardiographic data acquisition was performed by automatic transducer rotation at 2 degree increments over a span of 180 degrees. The transesophageal probe was linked to an ultrasound unit and to a 3D- workstation capable of ECG- and respiration gated data acquisition, postprocessing and 2D/3D image reconstruction. The mitral valve was visualized in sequential cross-sectional planes out of the 3D data set. The spatial position of the planes was indicated in a reference image. In the cross-sectional plane with the narrowest part of the leaflets the orifice area was measured by planimetry. For topographic information a 3D view down from the top of the left atrium was reconstructed. Measurements were compared to conventional transthoracic planimetry, to Doppler-echocardiographic pressure half time and to invasive data. The mean difference to transthoracic planimetry, pressure half time and to invasive measurements were 0.3 +/- 0.1 cm2, 0.2 +/- 0.1 cm2 and 0.1 +/- 0.1 cm2, respectively. Remarkable differences between the 3D- echocardiographic and the 2D- or Doppler- echocardiographic methods were observed in patients with severe calcification or aortic regurgitation. In 22% of the patients the 3D data set was not of diagnostic quality. New diagnostic information from a 3D view of the mitral valve could be obtained in 69% of the patients. Thus, although image quality is limited, 3D- echocardiography provides new topographic information in mitral valve stenosis. It allows the use of a new quantitative method, by which image plane positioning errors and flow-dependent calculation is avoided.

Adult↗

PubMed1996

Mid-term results of pulmonary thromboendarterectomy for chronic thromboembolic pulmonary hypertension.

BACKGROUND: In patients with chronic thromboembolic pulmonary hypertension, acute and striking decreases of pulmonary artery pressures and vascular resistance can be achieved by pulmonary thromboendarterectomy. In this study, the long-term effects of pulmonary thromboendarterectomy on hemodynamic indices and right ventricular function were investigated. METHODS: Sixty-five patients (31 women and 34 men; mean age, 47 +/- 17 years; range, 19 to 69 years; New York Heart Association [NYHA] functional class II, n = 3; class III, n = 38; class IV, n = 24) were reassessed 13 to 48 months (mean, 27 months) after pulmonary thromboendarterectomy. Measurements are reported as mean +/- standard deviation. RESULTS: All patients reported a significant improvement of symptoms: 46 patients were in NYHA functional class I, 16 patients in class II, and 3 patients in class III. Mean pulmonary vascular resistance was significantly reduced compared with preoperative and postoperative values (preoperative: 1,015 +/- 454 dynes.s.cm-5; postoperative: 322 +/- 154 dynes.s.cm-5; follow-up: 198 +/- 72 dynes.s.cm-5; p < 0.001 versus preoperative; p < 0.025 versus postoperative). Concomitantly, cardiac index was significantly increased compared with preoperative values (preoperative: 2.0 +/- 0.7 L.min-1.m-2; follow-up: 2.9 +/- 0.5 L.min-1.m-2; p < 0.001). Significant reductions of right ventricular dimensions and recovery of right ventricular function could be demonstrated radiologically and echocardiographically. In 3 patients (preoperative NYHA class IV, NYHA class III at follow-up) with proven coagulation abnormalities, pulmonary vascular resistance was moderately increased at follow-up compared with postoperative measurements. CONCLUSIONS: In patients with chronic thromboembolic pulmonary hypertension, a persistent decrease of pulmonary vascular resistance and improvement of right ventricular function and NYHA functional status can be achieved by pulmonary thromboendarterectomy.

Adult↗

PubMed1996

Expression of cell adhesion molecules in lung cancer cell lines.

Cell adhesion mechanisms are among the basic aspects in organism development. Adhesion molecules are involved in the building of complex structures and of association of the tissue. They also mediate as substratum adhesion molecules and are involved in the building of the scaffold. The process of tumor growth and metastasis is a complex cascade of events (FIDLER 1989). For many of these steps the tumor cells must be able to change their degree of adherence. Tumor progression and metastatic dissemination are tightly linked with the ability of the tumor cells to interact with other cells and with the extracellular matrix. The first step of metastasis is the active migration of tumor cells into the surrounding tissue.

Antigens, CD↗

PubMed1996

The extended transseptal approach in complex mitral valve surgery--evaluation of risks and benefits.

The extended transseptal approach to the mitral valve was used in 32 patients undergoing isolated or combined mitral valve surgery. In all cases exposure of the entire mitral valvular apparatus was excellent. Two patients died of low output within 30 days of surgery. No cause of death was related to the extended transseptal approach. In one early patient reexploration revealed arterial bleeding from the right atrial suture line which was caused by damage to the sinus nodal artery. In 7 patients temporary atrial conduction disturbances occurred which completely resolved within 10 days after responding well to dual-chamber pacing. Temporary ventricular pacing was necessary in two patients with preoperative bradyarrhythmia. In two patients undergoing mitral re-do surgery a permanent ventricular pacer was implanted. The extended transseptal approach offers an excellent exposure of the entire mitral valve both in primary isolated or combined mitral surgery particularly in re-do surgery where the primary standard vertical left atriotomy is impeded or the conventional transseptal approach gives only limited access. Temporary atrial dysrhythmia is not crucial and is easily controlled by short-term dual-chamber pacing.

Arrhythmias, Cardiac↗

PubMed1996

Extrathoracic arteriosclerotic vascular changes preclude the use of the internal thoracic artery for coronary artery bypass grafting.

During a two-years period we have treated 6 patients where use of the internal thoracic artery for coronary artery grafting was precluded because of extrathoracic arteriosclerotic vascular lesions. In four patients with severe aorto-iliac occlusive disease preoperative digital angiography demonstrated collateralisation of the lower extremity by either the left, right, or both internal thoracic arteries (ITA). In these cases use of the ITA was excluded in order to preserve the collateral supply and coronary bypass grafting was performed using only saphenous vein. In two patients with proximal occlusion of the left subclavian artery the right ITA was used as in-situ bypass to graft the left anterior descending artery. All patients survived the operation without development of a perioperative myocardial infarction, neurological deficit, or peripheral ischemia. Although they rarely do, extrathoracic vascular disorders can exclude the use of the ITA for grafting. Especially in the case of aorto-iliac occlusive disease or proximal arteriosclerotic subclavian lesions angiographic evaluation is mandatory to prevent the development of life-threatening peripheral ischemia by harvesting an ITA and to avoid the use of an inadequate ITA graft with in-flow occlusion.

Aged↗