Coronary artery revascularization using both ITAs as free conduits in patients with three-vessel disease--the lambda graft.

BACKGROUND: There is little information on using internal thoracic arteries (ITA) as free conduits in coronary artery bypass grafting. This study examines the results using both ITAs as free grafts in a lambda configuration implanting the common trunk into the ascending aorta. METHODS: Over a 6-year period, 317 patients underwent coronary artery revascularization with both ITAs as free grafts in a lambda configuration. RESULTS: An average of 4.9 distal anastomoses per patient was performed. There were 4 deaths (three early and one late). The mean NYHA class improved from preoperatively 2.8 to 1.1 at the last check. All 16 patients with suspected recurrent angina or a pathologic exercise test were restudied by angiography. Segmental graft stenosis or occlusion was found in 13 (in only one at aortic anastomosis). Five patients underwent late PTCA, and two underwent coronary reoperation. The six-year actuarial survival was 98% (90 % CL+/- 2 %), intervention-free survival 96 % (90 % CL +/- 2 %). CONCLUSION: Revascularization using both ITAs as free grafts in a lambda configuration gives good early and mid-term results for up to 6 years. The aortic ITA anastomosis can be considered safe.

[Abdominal aortic aneurysms. Results of surgical treatment from 1987 to 1998]. / Das Bauchaortenaneurysma. Resultate der chirurgischen Behandlung von 1987 bis 1998.

Conventional open surgery for abdominal aortic aneurysm has recently been challenged by a closed transfemoral approach for repair (stent-graft). The presented data over the past eleven years after open surgery for graft implantation are intended to serve for comparison with future results after transfemoral graft placement. In addition, it is the purpose of this study to investigate the prognostic importance of treatment of concomitant coronary artery disease. Early mortality of all 195 consecutive patients with abdominal aortic aneurysm repair was 1.5%; it was 0.6% after elective repair for infrarenal aneurysm and not dependent on the presence of coronary artery disease if the latter was treated. Late outcome, however, related closely to coronary artery disease as a major risk factor. Late graft complications are extremely rare and occurred only once (graft thrombosis). Incisional hernias and impotence in male patients are non-lethal complications affecting quality of life. Open surgical repair of abdominal aneurysm is safe, and long-term, complication-free survival is good. Coronary artery disease is the most frequent concomitant disease and major risk factor requiring close observation and treatment. These results need to be matched by the new transfemoral graft implantation technique before broad application of the latter.

[Catheter-induced dissection of the right coronary ostium and aortic root]. / Katheter-induzierte Dissektion des rechtskoronaren Ostiums und der Aortenwurzel.

We describe a catheter-induced dissection of the ostium of the right coronary artery extending to the aortic root. As an alternative to emergency surgery, a dacron stent-graft was placed in the proximal right coronary artery, thus, sealing the dissection. The patient later underwent elective aortocoronary bypass surgery. The therapeutic options in this situation with diffuse coronary disease, in which only one severe culprit lesion can be identified, are discussed.

[Surgery of mitral valve insufficiency. Results of 10 years]. / Die Chirurgie der Mitralinsuffizienz. 10-Jahres-Resultate.

From 1987 to 1996 we operated on 263 patients for mitral insufficiency. Multiple valve operations were excluded, with the exception of tricuspid reconstruction for functional regurgitation. The perioperative mortality was 3%, while the late mortality rate during a mean follow-up period of 3.5 years amounted to 2% per patient year and 1.7% if only cardiac causes were considered. The prognosis for patients with rheumatic, endocarditic and ischemic valvular disease was much worse compared to that for a degenerative cause. The latter group consisted of 209 patients with an operative mortality of 1.4% and a late mortality rate per patient year of 1.4% and 0.9% for cardiac causes only. Further analysis showed a significant prognostic improvement for patients with a preoperative ejection fraction of more than 60% and a repairable valve.

Implantation of the Toronto SPV stentless porcine bioprosthesis in dilated ascending aorta.

In the presence of severe dilatation of the ascending aorta the implantation of a Toronto SPV stentless bioprosthesis is compromised by the risk of postoperative central regurgitation. A modification of the implantation technique is described that restores the normal shape of the ascending aorta and thereby avoids the risk of dysfunction of the prosthesis.

[Cerebral insult in heart surgery]. / Der zerebrale Insult in der Herzchirurgie.

The aim of the study was to identify causes for perioperative stroke in cardiac surgery in order to reduce its occurrence. From 1989 to 1994, 3593 open heart operations were performed in adult patients. In 59 patients carotid endarterectomy for high grade stenosis was combined with the cardiac operation. There were a total of 68 (2%) focal strokes, 41 of which were considered minor and 14 major; 13 were lethal. The etiology of the 27 major and lethal events was most probably an embolus from the ascending aorta (6), from the ascending aorta or a cardiac valve (5), a thrombus in the left heart (6), air (1), cardiac arrest and resuscitation (4), cerebral hemorrhage (1), preoperatively unknown but high grade internal carotid stenosis (3), and a 50% stenosis of both internal carotid arteries preoperatively known but not operated on (1). There were 2 minor but no major neurologic complications in patients undergoing a combined carotid and cardiac procedure. A wide indication for preoperative neuroangiologic examination, echocardiography and careful intraoperative management may help to identify sources of possible emboli. Endarterectomy of high grade carotid stenosis is recommended simultaneously with the cardiac procedure.

[Cardiology 1995]. / Herzmedizin 1995.

Rapid progress in the field of cardiology calls for an almost continuous update on latest developments. In particular, this is the case with respect to indications for diagnostic and therapeutic interventions. The present contribution deals with some topics in this area. The first article elaborates on the theme of which diagnostic test is indicated, under what circumstances, and for which patient. Technical improvements in the surgical practice of coronary revascularization are discussed in the light of better therapeutic results. Unsolved questions of percutaneous dilatation (PTCA) are critically reviewed in a third article. Current problems in surgical treatment of valvular heart disease are dealt with in the fourth report. Finally, the enormous progress in pacemaker medicine that has accumulated since the world-wide first implant in 1959 by A. Senning is summarized in the last contribution.

Development of nitrate tolerance in human arteries and veins: comparison of nitroglycerin and SPM 5185.

Nitrate tolerance is a clinical problem in patients with coronary artery disease and heart failure. Human internal mammary arteries and saphenous veins obtained intraoperatively were suspended in organ chambers, and isometric tension was measured. In the artery, nitroglycerin elicited a potent relaxation, which was significantly diminished after prolonged incubation with nitroglycerin (10(-6) M, 1 h). In contrast, no tolerance occurred in saphenous vein under the same conditions. However, incubation with 10(-5) M nitroglycerin also developed tolerance. Compared to nitroglycerin, the new cysteine-containing mononitrate SPM 5185 exhibited a lower sensitivity but comparable maximal relaxation in arteries and veins. In nitroglycerin-tolerant arteries and veins, SPM 5185 caused relaxations similar to those under control conditions. Our results show that in isolated blood vessels, vascular nitrate tolerance occurs more readily in the mammary artery than in the saphenous vein. SPM 5185 seems to be less prone to the development of tolerance, which may be advantageous during chronic nitrate therapy.

[Acquired heart diseases and pregnancy]. / Erworbene Herzkrankheiten und Schwangerschaft.

Understanding of the mechanisms of cardiovascular and hemodynamic adaptation during pregnancy helps to prevent or manage complications in cardiac patients during gestation. Manifestations of coronary heart disease are exceptional during pregnancy and delivery. The same is true of disorders of the pericardium. Peripartal cardiomyopathy is a myocardial disorder of undetermined cause occurring shortly before, during or after delivery, which may take a fatal course. Hypertrophic obstructive or non-obstructive cardiomyopathy is compatible with gestation and delivery without serious complications in most cases. Rheumatic mitral stenosis was the most common cardiac disorder until the 1950s. Nowadays it is rarely seen in this country. Surgical and other interventional therapies have greatly changed the outlook in pregnant women with valvular heart disease. A highly controversial issue is heart valve replacement in young women and management of anticoagulation during pregnancy. Like any other drug therapy, anticoagulation during gestation requires careful weighing of the benefit for the mother against toxic and teratogenic effects for the fetus. In women with heart disease the management of pregnancy should start, if possible, before conception. Thorough counseling and proper planning of pregnancy and of therapeutic measures is essential in order to avoid or manage complications.

Thrombin-induced endothelium-dependent inhibition and direct activation of platelet-vessel wall interaction. Role of prostacyclin, nitric oxide, and thromboxane A2.

BACKGROUND: Platelet-vessel wall interaction plays an important role in acute cardiovascular disorders. Thrombin is a potent platelet activator but also has profound effects on the endothelium. Endothelial cells possess antithrombotic activity by releasing nitric oxide and prostacyclin, both potent vasodilators and platelet inhibitors. We studied the role of thrombin as a regulator of platelet-vessel wall interaction in isolated human arteries suspended in organ chambers for isometric tension recording. METHODS AND RESULTS: In arteries with endothelium, thrombin (0.01 to 1 U/mL) induced endothelium-dependent relaxations, which were reduced by the nitric oxide synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME; 10(-4) mol/L) and/or indomethacin (10(-5) mol/L). Human platelets (75,000/microL) evoked only marginal contractions in arteries with endothelium (3 +/- 3% of the contraction to KCl 100 mmol/L; NS), which were markedly enhanced by endothelial removal (22 +/- 4%; P < .05). Thrombin (1 U/mL) did not affect the response to platelets in arteries with (6 +/- 5%; NS) but induced a huge contraction in rings without endothelium (53 +/- 6%; P < .01 versus control without endothelium). The potent contraction to thrombin-activated platelets (1000 to 75,000/microL) in arteries without endothelium was markedly inhibited by the thromboxane A2 synthetase/receptor antagonist ridogrel (10(-5) mol/L; P < .005 versus control) and the single-acting thromboxane receptor blocker SQ-30741 (10(-7) mol/L; P < .01 versus control). CONCLUSIONS: Thus, thrombin directly stimulates platelets to release thromboxane A2, inducing potent vasoconstriction, which is prevented by the simultaneous thrombin-induced release of prostacyclin and nitric oxide from endothelial cells. In arteries devoid of functional endothelial cells, as occurs in patients with coronary artery disease, a combined inhibition of thromboxane production and action provides a potent therapeutic tool to interfere with the thrombin-induced activation of platelet-vessel wall interaction.

Both ETA and ETB receptors mediate contraction to endothelin-1 in human blood vessels.

BACKGROUND: Endothelin (ET)-1 has potent vascular effects. Two endothelin receptors have been cloned, namely, the ETA receptor, which preferentially binds ET-1, and the ETB receptor, which equally binds ET-1 and ET-3 and preferentially sarafotoxin S6c. We characterized endothelin receptor subtypes on vascular smooth muscle and endothelium of isolated human internal mammary artery (IMA) and vein (IMV) and porcine coronary artery (PCA) using the ETA antagonists FR139317 and BQ-123, the ETB ligand sarafotoxin S6c, and the ETA/ETB antagonist Ro 47-0203 (bosentan). METHODS AND RESULTS: In endothelium-denuded IMA and PCA and less so in IMV, FR139317 and BQ-123 (in PCA only) shifted the concentration-contraction curves to ET-1 parallel to the right. However, even at 10(-5) mol/L, FR139317 did not inhibit a high-sensitivity portion of the concentration-contraction curve. Moreover, the ETB receptor agonist sarafotoxin S6c induced contraction in vessels preincubated with FR139317. IMV was significantly more sensitive to the contractile effect of ET-1 and sarafotoxin S6c than was IMA (P < .05). Prolonged incubation with sarafotoxin S6c (to downregulate ETB receptors) and FR139317 eliminated the contraction resistant to FR139317. The ETA/ETB receptor antagonist bosentan caused a parallel shift of the concentration-contraction curve to the right at all concentrations of endothelin. ETB receptor mRNA was detected by Northern blot analysis in IMA and aortic smooth muscle cells. In precontracted IMA and PCA with endothelium, sarafotoxin S6c did not cause endothelium-dependent relaxations, whereas transient responses occurred in IMV. CONCLUSIONS: Vascular smooth muscle cells of human IMA, IMV, and PCA contain both ETA and ETB receptors, whereas the endothelium of IMA and PCA does not express functional ETB receptors linked to nitric oxide and/or prostacyclin production. Hence, inhibition of endothelin-induced contraction in patients requires the use of combined ETA/ETB antagonists.

[Work load in occupations]. / Belastbarkeit im Beruf.

Fewer subjects return to work after acute myocardial infarction or a cardiac surgical procedure than one would expect from the results of their medical examinations and cardiac tests. To decide whether a patient is able to return to work, one has to assess his individual prognosis and measure his maximal physical working capacity without cardiac dysfunction. Psychological and socioeconomic aspects have also to be considered. Recommendations are presented for practical procedure in assessing the ability of a patient to return to work.

The internal mammary artery 'string phenomenon'. Analysis of 10 cases.

The internal mammary artery (IMA) string sign has been described as a narrowing of IMA grafts in the late course after coronary artery bypass grafting. It has been assumed that this phenomenon was due to competitive flow in grafts connected to only mildly stenosed coronary arteries. We analyzed 10 cases of IMA string sign operated on between March 1988 and June 1991. Bilateral IMA was used in six cases and unilateral IMA in four. The mean interval between operation and reangiography was 14 +/- 11 months. String sign of the whole length of the IMA was detected in nine cases, and of the distal part between two sequential anastomoses in one. In all cases, the stenosis of the vessel bypassed with the narrowed graft proved to be only mild (50% or less) at reangiography. In all six cases with bilateral IMA grafts, the contralateral IMA was widely patent. These were all connected to highly stenosed or occluded coronary arteries. With respect to this observation, there is a high index of suspicion that the string phenomenon occurs due to competitive flow in only mildly stenosed coronary arteries. We decided, for our strategy in coronary artery surgery, still to aim at complete revascularization using IMAs as much as possible, but to avoid connecting IMA grafts to only mildly or moderately stenosed coronary arteries.

Different effects of angiotensin-converting enzyme inhibition in human arteries and veins.

The renin-angiotensin system (RAS) participates in the regulation of vascular tone; its effects were studied in human internal mammary artery (IMA) and saphenous vein (SV) suspended in organ chambers for isometric tension recording. The angiotensin-converting enzyme (ACE) inhibitor enalaprilat (10(-7) M) markedly augmented endothelium-dependent relaxations to bradykinin in SV (concentration shift: 10-fold; n = 6; p < 0.005), but not in IMA; in both blood vessels, it had no effect on endothelium-dependent relaxations to acetylcholine. The contractions to angiotensin I (Ang I; 10(-7) M) were markedly inhibited by enalaprilat (10(-7) M) in SV (control: 34 +/- 6% of 100 mM KCl; treatment: 18 +/- 6%; n = 7; p < 0.05) but not in IMA (control: 33 +/- 4%; treatment: 30 +/- 6%; n = 7; NS) and abolished by the Ang II receptor antagonist DuP 753 (10(-7) M) in both blood vessels. Ang II (10(-7) M) induced more pronounced contractions than Ang I in IMA (63 +/- 4%) and SV (63 +/- 5%; n = 5-6; p < 0.05 vs. Ang I), which was markedly inhibited by DuP 753 (10(-7) M; IMA: 21 +/- 5%; SV: 32 +/- 5%; p < 0.05). Thus, in SV but not IMA, ACE inactivates bradykinin and thereby blunts endothelium-dependent relaxations to the peptide and converts Ang I to Ang II.

Different effects of activated platelets in the right gastroepiploic and internal mammary arteries. Implications for coronary artery grafting.

The right gastroepiploic artery is increasingly utilized as an alternative coronary bypass conduit, although postoperative spasm can represent a problem. Platelet-vessel wall interactions are important determinants of graft function and patency. We studied the effects of activated platelets in porcine and human gastroepiploic and mammary arteries. Arterial rings were suspended in organ chambers for isometric tension recording. In the porcine and human gastroepiploic arteries with or without endothelium contracted with norepinephrine, activated platelets evoked only further and strong contraction. In contrast, in the porcine and human mammary arteries, endothelium-dependent relaxations to platelets mediated by nitric oxide were noted, particularly in rings preincubated with the thromboxane A2 receptor antagonist SQ-30741 and the 5-hydroxytryptamine (5HT2)-serotonergic receptor antagonist ketanserin. Although endothelium-dependent and endothelium-independent relaxation to bradykinin and the nitrovasodilator 3-morpholino sydnonimine were more pronounced in the gastroepiploic than in the mammary artery, norepinephrine, serotonin, and potassium chloride evoked much stronger contractions in the former than in the latter. Thus activated platelets induce pronounced contraction of the gastroepiploic artery that may contribute to postoperative spasm. The administration of antiplatelet drugs and vasodilators that prevent the effects of thromboxane A2 and serotonin may be beneficial for gastroepiploic graft function.

Similar endothelium-dependent relaxation, but enhanced contractility, of the right gastroepiploic artery as compared with the internal mammary artery.

The right gastroepiploic artery is an alternative coronary bypass graft. The excellent graft function of the internal mammary artery has been related to its physiologic properties, particularly to endothelial function. Isolated artery rings were suspended in organ chambers for recording of isometric tension. Norepinephrine and potassium chloride evoked threefold greater contractions in the gastroepiploic artery than in the mammary artery (p less than 0.01 to 0.05), whereas the sensitivity to the catecholamine was comparable. Acetylcholine induced endothelium-dependent relaxations, but the sensitivity (pD2: 6.7 +/- 0.3) and maximal relaxation (81% +/- 9%) were slightly less in the gastroepiploic artery than in the mammary artery (pD2: 7.6 +/- 0.2; 100% +/- 0%; p less than 0.05). Histamine induced endothelium-dependent relaxations with a similar sensitivity (pD2: 7.5 +/- 0.3 and 7.2 +/- 0.1), whereas the maximal relaxation was slightly enhanced in the gastroepiploic artery. The relaxation to the nitric oxide donor SIN-1 was identical in the two arteries. Thus the right gastroepiploic artery exhibits better contractility than the internal mammary artery but comparable endothelium-dependent and endothelium-independent relaxations. The good endothelial function of the gastroepiploic artery might be important for graft function and patency, whereas the enhanced contractility may facilitate vasospasm, especially in the presence of high circulating levels of catecholamines.

[Developments in mitral valve surgery]. / Entwicklungen in der Mitralklappenchirurgie.

Between 1987 and 1990 we operated on 104 patients for mitral valve disease. If possible the valve was reconstructed according to CARPENTIER's technique: 8 of 28 stenotic, 43 of 57 regurgitant and 2 of 7 mixed lesions were repaired. Twelve patients underwent re-replacement of a previously inserted mitral prosthesis. Six patients died early (7.8% after replacement, 8% after isolated replacement, 3.7% after repair and 2% after isolated repair). Five of these six patients were in NYHA class IV preoperatively. Seven patients died late after a mean observation period of 18 months (5 after replacement, 1 after double valve replacement and 1 after repair and multiple coronary bypass surgery). Prognosis is best for patients whose valve can be repaired and who are not already in NYHA class IV. The postoperative NYHA class for surviving patients is excellent (1.3 in the replacement group and 1.2 after repair).

[Emergency surgery for PTCA complications: tactics and results]. / Notfallchirurgie bei PTCA-Zwischenfällen: Taktik und Ergebnisse.

Incidence, risk and results of emergency coronary bypass surgery after failed percutaneous transluminal coronary angioplasty (PTCA) have been analyzed in a retrospective study. Failed PTCA has been defined as visible pathology (dissection, occlusion) of the dilated vessel associated with acute chest pain and ECG changes. From 3-1-1987 to 11-30-1990, 23 patients of 433 (5%) underwent emergency surgery for failed PTCA (19 male, 4 female, mean age 55 +/- 8 years). PTCA was performed in 16 cases of one-vessel-disease, 3 cases of two-vessel-disease and 4 cases of three-vessel-disease. All had an ejection fraction beyond 40%. 19 patients remained in stable hemodynamic condition. In average 2.1 vessels have been bypassed; in 13 cases the internal mammary artery (IMA) has been used, in 10 cases the saphenous vein (VSM) only. No early nor late death occurred. The perioperative infarction rate is 30%. Comparing the group with IMA and the group with VSM only, no difference could be found regarding the number of unstable hemodynamics, the use of catecholamines nor the perioperative infarction rate. After a mean follow-up period of 14.3 months, 21 patients are in NYHA class I, 2 in NYHA class II. Emergency coronary bypass surgery can be performed with low risk and favorable results, if the operation is timed without delay after the onset of acute chest pain and ECG changes in failed PTCA. The infarction rate is remarkably higher than in elective coronary surgery. The use of the IMA seems to be no additional risk factor.

[Use of the right gastroepiploic artery as a coronary bypass graft. Indications, technique and early results]. / Die Verwendung der Arteria gastroepiploica dextra (RGE) als koronarer Bypassgraft. Indikationen, Technik und Frühresultate.

435 isolated coronary artery procedures have been performed between January and December 1989 at the HerzZentrum Hirslanden. In 93% of the cases, one or two internal mammary arteries (IMA) and in 7%, saphenous vein grafts only were used as a bypass conduit. In 12 patients, the right gastroepiploic artery (RGE) was used as a free (3) or pedicled (9) graft to the posterior surface of the heart. This group of 12 patients was analyzed in a retrospective study. Postoperative complications in this group included one myocardial infarction and reexploration for intraabdominal bleeding in the same patient. All patients were discharged from hospital after an average of 9.7 days. After a mean follow-up time of 5 months, all patients are in NYHA-functional class I without antiischemic drugs. Postoperative angiography in 7 patients (mean postoperative interval 4 months) showed all 13 IMA-grafts and 5 RGE-grafts patent, 1 RGE-conduit is occluded, 1 RGE-graft could not been assessed for technical reasons. The RGE is an viable additional arterial bypass conduit and an alternative to other grafts. Indications for use of the RGE are lack of sufficient other conduits, calcified ascending aorta, coronary reoperation after vein graft failure and probably young patients with severe hyperlipidemia.