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G Lutter

Publications and source records attributed to G Lutter.

At least 19 recordsLinked to original sources
PubMed2001

Improved 3-D-echocardiographic endocardial border delineation using the contrast agent FS069 (Optison) transesophageal studies in a porcine model.

3-D echocardiography has the potential for quantitative assessment of regional wall motion. However, the 3-D procedures used to date do not provide the same spatial and temporal resolution as 2-D echocardiography, which results in problems with border delineation of the endocardium. There are, as yet, few studies testing if the use of contrast agent can improve endocardial definition in the 3-D data set. FS069 (Optison) was used for the first time for this purpose in the present study. A total of 12 mechanically-ventilated pigs were examined by transesophageal 3-D echocardiography, 1. using fundamental imaging and 2. following left-atrial injection of FS069 (Optison). The left ventricle was analyzed using an 18-segment model. Score with the value 0 (not visible), 1 (moderately visible) and 2 (well defined) were used to rate endocardial definition. All segments were assessed both end-diastolic and end-systolic. Various LV regions were examined by grouping segments (anterior/lateral/inferior and basal/mid-ventricular/apical). Using the contrast agent, the proportion of nonvisible segments fell diastolic from 40 (18.5%) to 15 (6.9%), and systolic from 26 (12.0%) to 11 (5.1%). The proportion of well defined segments increased diastolic from 62 (28.7%) to 108 (50%) and systolic from 73 (33.8%) to 123 (56.9%). The mean visibility score increased diastolic from 1.10 +/- 0.68 to 1.43 +/- 0.62 (p < 0.001), systolic from 1.22 +/- 0.64 to 1.52 +/- 0.59 (p < 0.001). The benefit was greatest in regions where the visibility score was lowest without contrast: in the area of the lateral wall and systolic near the apex. In conclusion, the use of FS069 (Optison) results in significantly better endocardial delineation in the 3-D data set. This could be important in future for the 3-D echocardiographic assessment of regional wall motion.

Albumins↗
PubMed2001

Microperfusion enhancement after TMLR in chronically ischemic porcine hearts.

OBJECTIVE: The purpose of this study was to determine the effect of transmyocardial laser revascularization (TMLR) on myocardial perfusion and function in chronically ischemic myocardium. METHODS: In the first operation a stenosis of the left anterior descending artery was created in 20 open-chest anesthetized pigs to implement this ischemic model. In contrast, four pigs served as controls (thoracotomy only). Seven days later (2nd operation), all animals were studied at baseline by analyzing different parameters of perfusion (radioactive microspheres), function, and intramyocardial pressure. Afterwards, pigs who received a left anterior descending artery stenosis were randomized into one of three groups: animals in laser group 1 (n=7) received one and in laser group 2 (n=7) two laser channels per cm(2) in the left anterior descending artery territory. Animals of the ischemic group (n=6) underwent the same procedures without transmyocardial laser revascularization. Three months later, the animals were re-studied (3rd operation) and additional analysis of histochemistry and myocardial water content was performed. RESULTS: Regional myocardial blood flow (RMBF) in laser group 2 revealed statistically higher RMBF values compared to the ischemic group (0.39+/-0.13 versus 0.14+/-0.12 ml/min/g; P=0.043), after 3 months, whereas the absolute RMBF had not increased compared to the 1-week baseline values. Left ventricular stroke work index (LVSWI) at rest and under stress did not show any improvement compared to the initial values in all study groups (P=ns). Nevertheless, laser group 1 demonstrated relatively higher LVSWI(max) values compared to the ischemic (1.33+/-0.19 versus 0.93+/-0.16 mJ/kg; P=0.03) and laser group 2 (1.33+/-0.19 versus 1.02+/-0.15; P=0.024). Regional contractility of laser groups 1 and 2 recovered after 3 months (which had deteriorated shortly after transmyocardial laser revascularization) and increased under stress (100% versus 144.33+/-46.42, P=0.029 and 100% versus 116.26+/-21.06, P=0.034; respectively). In contrast, the corresponding ischemic group values were not different from initial values (P=ns). CONCLUSIONS: This model of chronic regional ischemia demonstrates that CO(2)-laser revascularization significantly improves microperfusion and regional function, whereas the overall perfusion and global LV function is unchanged.

Angioplasty, Laser↗
PubMed2001

Investigations on the new free radical scavenger polynitroxyl-albumin to prevent ischemia and reperfusion injury after orthotopic heart transplantation in the pig model.

OBJECTIVE: Nitroxides have strong antioxidant capacity but their effectiveness is limited by their rapid intracellular inactivation. Polynitroxyl-Albumin (PNA) is capable of regenerating inactivated nitroxide. We tested the effect of PNA against reperfusion injury in heart transplantation. METHODS: Pig hearts were transplanted orthotopically. In the control group (n=9) reperfusion was performed without reperfusion modifications. In the experimental group (n=10) 1 ml/kg PNA was given before cross-clamp release. RESULTS: Hemodynamic performance was impaired after transplantation in both groups without significant intergroup differences. Plasma malonedialdehyde levels were significantly diminished in the PNA group as compared to the controls. CK-MB levels in both groups were increased within the first 2 h of reperfusion without significant intergroup differences. In contrast, there were found significant higher values of myocardial specific lactate dehydrogenase (LD1) in the controls versus PNA group. CONCLUSIONS: PNA was able to reduce lipid peroxidation and attenuate free radical activity. Contractile dysfunction could no be improved, indicating that (a) the radical scavenging effect was to weak or (b) other mechanisms than free oxygen radicals are responsible for myocardial damage in this experimental model.

Albumins↗
PubMed2001

Endoscopic vs. conventional vein harvesting: first results with a new, non-disposable system.

BACKGROUND: Most of the grafts used in coronary bypass surgery are still venous grafts. The preferred vein for bypass surgery is the long saphenous vein. Severe wound complications caused by saphenous vein harvesting occur in 1 % to 3 % of cases. Minor complications that do not need surgical revision occur in up to 43 % of cases. We developed an endoscopic harvesting technique using non-disposable instruments to reduce wound complications caused by vein harvesting. METHOD: In a retrospective study, the occurrence of wound complications, haematoma, postoperative pain, ambulation, sensory disturbances and patient satisfaction were studied (n = 182). Patients who had either endoscopically harvested (n = 91) or conventionally harvested (n = 91) saphenous vein grafts were reviewed. RESULTS: Results were collected for 173 patients. The overall prevalence of wound complications was 18.7 %. The incidence of wound healing complications could be reduced significantly (p = 0.015) from 15.3 % to 3.4 % using the endoscopic technique. In the endoscopic group, postoperative ambulation was significantly (p = 0.002) easier, patient satisfaction was significantly (p = 0.007) higher, and postoperative leg swelling (p = 0.003) and haematoma (p = 0.004) could be reduced significantly. The occurrence of postoperative pain and sensory disturbances did not differ significantly. COMMENT: We conclude that the used endoscopic vein harvesting is a safe and cost effective method that can significantly reduce wound complications. An ongoing prospective study should establish our demonstrated data.

Aged↗
PubMed2000

[Bleeding problems in open heart surgery].

Across centers, transfusion can vary eightfold for the same mediastinal drainage after adult cardiac operations. Excessive blood drainage resulting in increased transfusions occurs in 29% of patients. Various strategies have been proposed to decrease bleeding and allogenic transfusion requirements in the perioperative period of heart surgery. Blood conservation methods were reviewed critically. Avoidance of preoperative anemia, tolerance of low hemoglobin concentrations, the use of autologous blood, and adherence to a strict transfusion protocol will reduce the use of allogenic transfusions. Perioperatively, maintenance of normothermia contributes to improved hemostasis.

Adult↗
PubMed2000

Evaluation of the indirect revascularization method after 3 months chronic myocardial ischemia.

OBJECTIVE: The long-term effectiveness of transmyocardial laser revascularization (TMLR) was evaluated in the setting of a severe left anterior descending artery (LAD) stenosis. METHODS: To employ the chronic ischemic model, pigs underwent three operative procedures over a 13-week period. In the first operation, an operative stenosis of the LAD was created. One week later, the animals were studied at baseline by analyzing different parameters of perfusion (microspheres), function and ECG changes. Afterwards, pigs were randomized into one of three different experimental groups: animals in laser group 1 received one laser channel (n=9) and laser group 2 two channels per cm(2) (n=6) in the LAD territory (using a CO(2)-laser). Animals of the ischemic group (n=12) underwent the same procedures without TMLR-treatment. Twelve weeks later, the animals were re-studied (third operation) and killed. Additional analysis of myocardial water content and histochemistry was performed. RESULTS: Chronic myocardial ischemia and regional myocardial blood flow (RMBF) in laser group 2 revealed relatively higher RMBF values compared with the ischemic group (P=0.015), after 3 months, but no absolute improvement of perfusion at rest compared with baseline was observed in all experimental groups. Left ventricular stroke work index (LVSWI) at rest and under stress did not show any improvement compared with initial values in all study groups (P not significant). However, laser group 1 demonstrated relatively higher LVSWI(max) values in comparison with the ischemic group (P=0.013) as did laser group 2 (P=0.017). Regional contractility of the laser groups recovered after 3 months (which was deteriorated shortly after TMLR, P<0.001) and increased under stress compared with baseline (laser 1: P=0.015, laser 2: P=0.017). In contrast, the ischemic group did not show any difference from initial values (P not significant). The lased pigs of group 2 were less prone to intractable ventricular fibrillation (P=0.036 vs. ischemic group), and showed a significant smaller area of necrosis in the area at risk (P=0.012 vs. ischemic group). CONCLUSIONS: This model of chronic regional ischemia demonstrates that CO(2)-laser revascularization significantly ameliorates microperfusion and regional contractility, and diminishes the incidence of ventricular fibrillation and necrosis in the area at risk. However, it does not change the overall perfusion and global LV function.

Animals↗
PubMed2000

Pathomorphological and histological analysis of the indirect revascularization method.

OBJECTIVE: This experimental study was initiated to determine whether TMLR may prevent porcine myocardium from ischemia and necrosis after acute myocardial infarction. In addition, the influence of TMLR on healthy myocardium was analyzed. METHODS: The short-term effectiveness of TMLR was evaluated in 38 open-chest anesthetized pigs with (n = 18) or without (n = 20) acute LAD occlusion (observation period 6 hours): Six pigs served as controls (thoracotomy only). An additional six pigs had LAD occlusion only (ischemic group). A subsequent 12 pigs were treated by TMLR (CO2) prior to LAD occlusion: Six pigs received one laser channel/cm2 (group 1) and in six pigs two channels/cm2 in the LAD territory (group 2) were performed. In addition, 14 pigs underwent TMLR without ischemia: Seven pigs received 1 channel/cm2 (group 3) and seven pigs 2 channels/cm2 (group 4). Pathomorphological assessment and histology were performed. RESULTS: TMLR limits the expansion of the myocardial infarction zone: laser group 2 demonstrated a significantly smaller area of necrosis in the area at risk (ischemic group (32%) vs. laser group 1 (18%, p = ns) and 2 (8%, p = 0.0076); laser group 1 vs. 2, p = 0.0056). The amount of the area of necrosis of laser groups 3 (0.4%) and 4 (0.04%) compared to control (0%) did not differ significantly (p = ns). Furthermore, in the lased territories of laser groups 3 and 4 microscopic analysis revealed signs of ischemia in 10 +/- 30.9% of all examined histological samples (p = ns vs. control). During a short coronary occlusion the laser-induced tracks were partially filled with blue dye in 94.8 +/- 27.0/85.9 +/- 34.3/94.85 +/- 22.0%/70.21 +/- 47.0% (laser groups 1 - 4 respectively p = ns) The myocardial water content-measurements (MWC) of the ischemia and laser group 1 were not different at the end of the experiment (p = ns). In contrast, laser groups 2, 3 and 4 revealed significantly higher MWC values compared to control (p = 0.036, p < 0.001, p < 0.001; respectively). CONCLUSIONS: This prolonged acute study demonstrates that preventive CO2-laser revascularization significantly reduces the amount of necrosis in the area at risk. Histological examination supported the idea that some pigment gained access to the ischemic tissue via patent channels. In healthy myocardium, TMLR significantly increases myocardial water content and induces non-significant small ischemic and very small necrotic areas surrounding open laser channels.

Animals↗
PubMed2000

Evaluation of transmyocardial laser revascularization by following objective parameters of perfusion and ventricular function.

BACKGROUND: Does transmyocardial laser revascularization (TMLR), a new surgical technique for treating patients with otherwise intractable angina pectoris, improve myocardial perfusion, metabolism, and, consequently, function? METHODS: Patients referred for TMLR, alone or with coronary artery bypass grafting (CABG), were preoperatively evaluated clinically and by treadmill stress testing, echocardiography, ventriculography, radionuclide assessment of perfusion and metabolism, and hemodynamic assessment. Intraoperatively it was decided that some patients only required CABG. Follow-up evaluations were repeated after 6 (n = 40) and 12 months (n = 23) and compared with preoperative values. RESULTS: CABG only was performed in 35 cases, TMLR + CABG in 17, TMLR only in 45. 1-year mortality was 11% in the TMLR, zero in the TMLR + CABG, and 11% in the CABG groups. In all groups a significantly improved CCS angina- and NYHA class was observed immediately after operation and after 6 and 12 months. In all study groups treadmill tolerance (p<0.05) improved, but regional and global function, perfusion at rest, and metabolism were not significantly changed at 6 and 12-months follow-ups. Perfusion studies under stress demonstrated an improvement only in the CABG group after 12 months (p<0.05), whereas in both TMLR groups the lasered ischemic segments remained unchanged. CONCLUSIONS: TMLR significantly improves long-term clinical status and treadmill stress tolerance, but appears to have little if any effect upon regional and global function, perfusion, and metabolism.

Aged↗
PubMed1999

Transmyocardial laser revascularization: experimental studies in healthy porcine myocardium.

BACKGROUND: Clinical studies have demonstrated a significant reduction of cardiac index shortly after transmyocardial laser revascularization in patients with low ejection fraction. We analyzed the influence of transmyocardial laser revascularization on healthy myocardium in pigs. METHODS: Carbon dioxide channels were created in 20 pigs which were observed for 6 hours. Ten pigs received one laser channel and ten pigs two laser channels per cm2 in the left anterior descending artery region. Seven pigs served as controls. Perfusion (microspheres), function, histochemical, and histologic assessments were subsequently performed. RESULTS: A significant deterioration of left ventricular stroke work index was observed shortly after transmyocardial laser revascularization in both laser groups (p < 0.05). After 6 hours the left ventricular stroke work index did not increase and showed significantly reduced values at rest (p < 0.05) and during stress in the laser groups (p < 0.01). Normal regional perfusion, small ischemic and necrotic areas, open laser channels in the left anterior descending artery region and significantly increased myocardial water content were observed in the laser groups (p < 0.01). CONCLUSIONS: Carbon dioxide laser channels significantly decrease global heart function shortly after transmyocardial laser revascularization in healthy porcine myocardium. This myocardial tissue showed no recovery 6 hours postoperatively.

Animals↗
PubMed1999

Analysis of the new indirect revascularization method by determining objective parameters of clinical chemistry, histo-chemistry and histology.

OBJECTIVE: This experimental study was initiated to determine whether transmyocardial laser revascularization (TMLR) after acute myocardial ischemia may improve clinical chemistry and diminish the amount of necrosis. In addition, the influence of TMLR on healthy myocardium was analyzed. METHODS: The prolonged short-term effectiveness of TMLR was evaluated in 44 open-chest anesthetized pigs with (n = 21) or without (n = 23) the setting of acute myocardial ischemia (observation period 6 h): seven pigs served as controls (thoracotomy only). An additional seven pigs had left anterior descending artery (LAD) occlusion only (ischemia group). A subsequent 14 pigs were treated by TMLR (CO2) prior to LAD occlusion: Seven pigs received one laser channel/cm2 (group 1) and in seven pigs two channels/cm2 in the LAD territory (group 2) were performed. In addition, 16 pigs underwent TMLR without ischemia: Eight pigs received one channel/cm2 (group 3) and eight pigs two channels/cm2 (group 4). Clinical chemistry, histo-chemical assessment and histology were performed. RESULTS: TMLR limits the expansion of the myocardial infarction zone: laser group 2 indicated a significant smaller area of necrosis in the area at risk (ischemic group (31%) vs. laser group 1 (19%), P = ns; laser group 2 (7%) vs. ischemic group, P < 0.01; laser group 1 vs. 2, P < 0.01). The amount of the area of necrosis and ischemia of laser groups 3 and 4 compared with control did not differ significantly (P = ns). Preventive creation of microchannels before ischemia did not diminish ischemic parameters (P = ns). The myocardial water content-measurements (MWC) in the ischemia, laser 1 and 2 groups did not show any difference at the end of the experiment, except higher values of laser group 2 (P < 0.05). Laser groups 3 and 4 revealed significantly higher MWC values compared with control (P < 0.001). CONCLUSIONS: This prolonged acute study demonstrates that CO2-TMLR significantly reduces the amount of necrosis in the area at risk, but does not reduce cardiac ischemic markers. In healthy myocardium, TMLR significantly increases myocardial water content and ischemic parameters and induces small ischemic and very small necrotic areas surrounding open laser channels. Generally, the elevated cardiac enzymes and proteins are mainly attributed to the expected rise caused by vaporization of myocardial tissue in all laser groups.

Analysis of Variance↗
PubMed1999

Successful orthotopic pig heart transplantation from non-heart-beating donors.

BACKGROUND: With the aim to expand the severely limited donor pool by use of non-heart-beating donors we developed a technique for successful transplantation of hearts after 30 minutes of normothermic ischemia without donor pretreatment. METHODS: In control groups hearts were transplanted in a conventional fashion using crystalloid cardioplegia (Group I, n = 6) or BCP (Group II, n = 8) for induction of cardiac arrest. In the ischemic groups hearts were harvested after 30 minutes of normothermic ischemia, perfused with blood cardioplegia (BCP) (Group III, n = 9) or BCP containing the Na(+)-H(+)-exchange inhibitor HOE 642 (Group IV, n = 8) and transplanted orthotopically. RESULTS: All animals could be weaned from cardiopulmonary bypass. Low dose inotropic support was necessary in the ischemic groups only. Recovery of the maximal left ventricular stroke work index (LVSWImax) in Groups I vs II was 62.6+/-19.6% vs 73.3+/-23.3% (NS), maximal right ventricular stroke work index (RVSWImax) averaged 61.1+/-18.8 vs 87.8+/-31.7% (NS) as compared to the preoperative level. In the ischemic groups (III vs IV) LVSWImax was 27.3+/-11.7 vs 59.5+/-32.4% (p = 0.038), RVSWImax was 27.4+/-20.9 vs 64.2+/-46.6% (NS). CONCLUSIONS: The results indicate that (a) successful pig heart transplantation after 30 minutes of normothermic ischemia is possible without donor pretreatment, and (b) that HOE 642 improves posttransplant LVSWImax significantly.

Animals↗
PubMed1999

[Transmyocardial laser revascularization].

The clinical experience with transmyocardial laser revascularization indicates that angina is relieved significantly, perfusion and treadmill tolerance are improved and hospital admissions are decreased. The exact mechanism for a laser revascularization linked improvement is still unknown. Transmyocardial laser revascularization should be used only in highly selected cases when conventional methods fail to improve patients symptoms. Further evaluation of the efficacy of the new indirect revascularization method in clinical (larger multicenter trials) and experimental studies to elucidate the mechanism of TMLR is warranted. Experimental long-term studies to explain the mechanism are in progress.

Humans↗
PubMed1998

[Treatment strategies in therapy refractory angina pectoris: transmyocardial laser revascularization].

BACKGROUND: Does transmyocardial laser revascularization (TMLR) as a new surgical technique for treating patients with otherwise intractable angina pectoris improve myocardial perfusion or contractility? METHODS: Sixty-seven patients transferred for TMLR were evaluated by clinical evaluation, treadmill stress testing, echocardiography, ventriculography, and hybrid positron emission tomography preoperatively and in patients treated with TMLR at 6 and 12 month follow up. Hemodynamic assessment and clinical evaluation were performed perioperatively. RESULTS: In 28/67 cases (42%) CABG, in 9/67 patients (13%) CABG in combination with TMLR (combined group), and in 30/67 patients (45%) only TMLR (sole group) were performed. Perioperative mortality in the sole group was 13%, in the combined group zero, and in the CABG group 11%. In all groups a significantly improved clinical status (p < or = 0.01) 1 week postoperatively and in TMLR groups also at 6 and 12 months was observed. In the TMLR groups treadmill tolerance (p < 0.05) improved, although function, perfusion, and metabolism did not change significantly at the 6 and 12 month follow up. CONCLUSION: TMLR significantly improves clinical status and treadmill stress tolerance, but does not change function, perfusion, and metabolism.

Aged↗
PubMed1998

Histologic findings of transmyocardial laser channels after two hours.

Histologic examination of the human myocardium has been performed several days, weeks, and months after transmyocardial laser revascularization. We performed microscopic examinations 2 hours postoperatively. In addition to the patent channel (diameter, 1 mm) and a 1-to 2-mm rim of necrosis, a 1- to 3-mm zone of myofibrillary degeneration was found. This additional reversible injury immediately after transmyocardial laser revascularization could explain the higher mortality rate in patients with reduced left ventricular function.

Aged↗
PubMed1998

Transmyocardial laser revascularization (TMLR) in patients with unstable angina and low ejection fraction.

OBJECTIVE: Does perioperative use of the intraaortic balloon pump (IABP) improve the postsurgical outcome of patients presenting with endstage coronary artery disease, unstable angina and low ejection fraction transferred for transmyocardial laser revascularization (TMLR)? METHODS: TMLR, as sole therapy combined with the perioperative use of an intraaortic balloon pump has been assessed in seven patients with endstage coronary artery disease, unstable angina and low ejection fraction (EF < 35%). Six out of seven patients had signs of congestive heart failure. These patients are compared with 23 patients with endstage coronary artery disease, stable angina and EF > 35%, who were treated with TMLR as sole therapy without the use of IABP. The creation of transmural channels was performed by a CO2-laser. All patients were evaluated by hybrid positron emission tomography (perfusion SPECT and viability PET) and ventriculography preoperatively. Echocardiography, clinical status and hemodynamic assessment by Swan Ganz catheter were performed perioperatively. RESULTS: The perioperative mortality of this combined procedure (TMLR and IABP) was zero. Three out of seven patients had pneumonia with complete recovery. Swan Ganz catheter examinations showed deterioration of LV-function after TMLR intraoperatively and improvement after 2 h and further after 6 h on ICU (P < 0.05). In contrast, a decrease of LV-function in sole TMLR patients with an EF > 35%) has not been observed. Patients with EF < 35% needed the IABP for 2.3 days and moderate dose catecholamines for a mean of 3.0 days. The postoperative EF and resting wall motion score index (WMSI) of all analysed LV segments (evaluated by echocardiography) did not change compared to baseline (EF 31.3+/-2.6 preop. to 32.8+/-3.2 postop.; WMSI: 1.75+/-0.14 at baseline to 1.71+/-0.17 postop.). The average Canadian Angina Class at the time of discharge decreased from 4.0+/-0 (baseline) to 2.3+/-0.5 (P < 0.05) and the NYHA-Index from 3.9+/-0.3 to 2.7+/-0.5. No patient had signs of angina pectoris, whereas two patients still had signs of congestive heart failure. CONCLUSIONS: The reported data support our concept to start IABP preoperatively in patients with reduced LV contractile reserve in order to provide cardiac support during the postoperative phase of reversible decline of LV-function induced by TMLR.

Aged↗
PubMed1998

Transmyocardial laser-revascularization: experimental studies on prolonged acute regional ischemia.

OBJECTIVE: This experimental study in pigs was undertaken to answer the question whether TMLR after acute myocardial infarction may improve regional myocardial perfusion, left ventricular function and diminish myocardial necrosis in the area at risk. METHODS: Thirty open-chest anesthetized pigs were observed for 6 h, six pigs served as controls. In 24 pigs, occlusion of the left anterior descending artery (LAD) beyond the first diagonal branch was performed: seven pigs had LAD occlusion only (ischemia group), and 17 pigs were treated by TMLR (using a CO2-laser, energy: 40 J) prior to coronary occlusion; nine pigs received one laser channel (1 mm diameter) per cm2 (laser group 1) and eight pigs two channels per cm2 in the LAD territory (laser group 2). Regional myocardial blood flow by microspheres, function (franc starling curves), histochemical assessment (triphenyl tetrazolium chloride, TTC and histology), were performed. RESULTS: The lased pigs were less prone to ventricular fibrillation (laser group 2, 38%; laser group 1, 56%; ischemic group, 100%; P < 0.05), and showed a significant smaller area of necrosis (TTC) in the area at risk (laser group 1, 23%; laser group 2, 14%; vs. ischemia group, 31%; P < 0.01). There was no significant difference between laser-treated and ischemia hearts regarding the amount of blood flow into the infarcted LAD region and the maximal left ventricular stroke work index after 6 h (P = n.s). Regional myocardial blood flow: ischemia group, 4 +/- 5 ml/100 g/min; laser group 1, 3 +/- 10 ml/100 g/min, and laser group 2, 2 +/- 10 ml/100 g/min; maximal left ventricular stroke work index: ischemia group, 1.8 mJ/g; laser group 1, 2.1 mJ/g and laser group 2, 2.1 mJ/g. CONCLUSIONS: This model of acute regional ischemia demonstrates that CO2-laser revascularization diminish significantly the incidence of ventricular fibrillation and necrosis in the area at risk, and does not change regional myocardial perfusion and global left ventricular function. This experiment indicates that TMLR may be an alternative in treating advanced ischemic heart disease.

Animals↗
PubMed1998

Orthotopic transplantation of pig hearts harvested after 30 min of normothermic ischemia: controlled reperfusion with blood cardioplegia containing the Na+-H+-exchange inhibitor HOE 642.

OBJECTIVES: The aim of our study was to develop a surgical technique for a successful transplantation of hearts harvested after 30 min of normothermic ischemia without donor pretreatment. Successful transplantation of ischemic compromised hearts could help to expand the severely limited donor pool. We used the pig model because this species is very susceptible to myocardial ischemia. Na+-H+-exchange (NHE) inhibitors have shown excellent protective properties in several in vitro and in vivo models of myocardial ischemia and reperfusion. METHODS: In group I (n=12) hearts were harvested after 30 min of normothermic ischemia following cardiac arrest induced by exsanguination. Hearts were perfused with warm blood cardioplegia and transplanted orthotopically. In group II (n=9) controlled reperfusion with cold leucocyte-depleted blood cardioplegia was performed after 30 min of normothermic ischemia. In group III (n=8) the same procedure was performed as in group II but blood cardioplegia contained 1 mmol/l HOE 642. RESULTS: In group I massive myocardial oedema was observed and none of the animals could be weaned from cardiopulmonary bypass (CPB). In contrast, all animals in groups II and III could be weaned from CPB with low dose inotropic support. In groups II and III the contractility of the hearts, expressed as maximal left and right ventricular stroke work index was significantly impaired after transplantation as compared with the preoperative value. Supplementation of blood cardioplegia with HOE 642 resulted in a significantly better recovery of the LVSWImax (Group II vs. III). CONCLUSIONS: Successful transplantation of pig hearts is possible after 30 min of normothermic ischemia without donor pretreatment if a controlled reperfusion with cold leucocyte-depleted blood cardioplegia is performed. HOE 642 given during reperfusion only improves posttransplant left ventricular function.

Animals↗