[Use of the internal thoracic artery in repeat myocardial revascularization surgery]. / Upotreba unutrasnje torakalne arterije u ponovnoj operaciji revaskularizacije miokarda.

The incidence of redo myocardial revascularization is increasing lately. These procedures are accompanied by the higher operative risk, and the use of internal thoracic artery graft may have additional negative impact on early-rization. Mortality and morbidity in this group did not differ significantly compared to a group where only venous grafts were used. Independent predictors of the unfavorable outcome (for both groups) were the presence of the chronic pulmonary disease, age over 65 and NYHA functional class IV. In the group with internal thoracic graft it was the age over 65, while in the group with only vein grafts it was chronic pulmonary disease. We have discussed potential problems during the redo procedure in patients in whom internal thoracic graft was used during the first procedure.

[Assisted circulation II--systems for intermediate and long-term mechanical circulatory support]. / Asistirana cirkulacija II--sistemi za intermedijarnu i dugotrajnu mehanicku potporu cirkulacije.

The concept of artificial circulatory support has been established almost 200 years ago. It has only been within the last four decades that physicians and engineers have developed mechanical assist devices that can temporarily support the circulation until the native heart recovers from a reversible injury. In patients who do not regain native heart function, long-term circulatory support or permanent replace (biologically--heart transplant or permanent mechanical circulatory support) is indicated. In this paper we describe the devices (ABIOMED BSV 5000, Thoratec, HeartMate, Novacor and CardioWest TAH), that are in current clinical use for intermediate and long-term mechanical circulatory support.

[The internal thoracic artery in myocardial revascularization in patients with severely depressed left ventricular function]. / Unutrasnja torakalna arterija u revaskularizaciji miokarda kod bolesnika s tesko ostecenom funkcijom leve komore srca.

INTRODUCTION: In most prospective, randomized studies, severely depressed left ventricular function is found to be the independent predictor of increased morbidity and mortality after myocardial revascularization [3]. Surgical treatment in this particular group of patients results in superior long-term results [1, 2]. Internal thoracic artery (ITA) is considered to be superior compared to venous grafts in myocardial revascularization for the majority of patients with ischaemic heart disease. However, its value in patients with already severely depressed left ventricular function (EF < or = 30%) is still a matter of debate. There are no prospective, randomized studies, so far. In some studies it was shown that revascularization with ITA graft resulted in superior long-term results (10- and 15-year follow-up) in all subgroups of patients, including those with severely depressed left ventricular function [4, 5]. Some authors find it still unacceptable, if this result would be possible at the expense of higher early mortality (due to use of ITA). The purpose of this study is to analyze the early and long-term results of myocardial revascularization using ITA graft in patients with severely depressed left ventricular function (EF < 30%). MATERIAL AND METHODS: Over the period from November 1986 through March 1999, 2860 pts have received ITA (alone or with additional vein grafts) for myocardial revascularization. In 431 pts EF was < or = 30% (15.1%), average EF being 25.7% (by echocardiography); 33 were women, 29 were diabetics, while average age was 56.7 +/- 8.4 years. The control group consisted of 430 pts, with similar preoperative characteristics, who received vein grafts alone. RESULTS: Operative mortality in the ITA group was 2.55% (11/431), and postoperative morbidity was 7.4% (32/431). In the group with vein grafts only the mortality was 3.25% (14/430) and morbidity 6.7% (29/430)--Table 2. The average postoperative hospital stay was 9.1 days (range 7-32). There was no difference in operative and postoperative parameters (extracorporeal time, ischaemic time, duration of mechanical ventilation, need for inotropic support, mortality, morbidity and hospital stay) compared to the group with vein grafts alone, except for the blood drainage--significantly higher in the ITA group--p < 0.00001)--Table 3. Multivariate analysis showed that independent predictors of unfavorable outcome were the presence of peripheral vascular disease (beta--0.9; p = 0.02) and aortic cross-clamp time (beta--0.02; p = 0.01). Long-term results in 14 pts with ITA graft operated on from 1986 to 1992 (6-12 years of follow-up) showed the survival of 92.7%. DISCUSSION: Superior long-term patency of ITA graft resulted in its practically routine use in myocardial revascularization. However, in some studies it was shown that ITA flow might be insufficient during the maximal effort [6]. This may result in hypoperfusion, low cardiac output syndrome and cardiac arrest. This frequently happens at the end of the operation, and may be accentuated with the use of vasopressors that can further decrease the ITA flow [9]. In patients with already severely depressed left ventricular function preoperatively, the use of vasopressors at the end of procedure when the myocardium may be quite vulnerable, is to be expected. Friesewinkel et al., [18] showed that there was an impairment of the regional contractility of the left ventricle early (up to 4 hours) after myocardial revascularization, when one or both ITA grafts were used. Since this was not the case if vein grafts were used, they advised to be careful in patients with "depressed left ventricular function". However, Elefteriades et al., [1] found no higher mortality in patients with "bad left ventricle" in whom ITA was used, but point out that patients with elective operation and without need for intensive care treatment preoperatively had much better outcome. Jagaden et al., [19] found very good results in these patients, after the routine use of ITA, during a 20-year follow-up. In our study EF < or = 30% was present in 861 patients, 431 with ITA graft and 430 with vein grafts only. There was no difference between groups considering all possible preoperative and operative factors of importance for the outcome. We found no increased early morbidity and mortality in patients in whom ITA was used compared to patients with vein grafts only. In patients operated on from 1986-1992 (follow-up of 6-12 years), we noted the survival of 92.7%. This was not statistically different compared to patients with vein grafts (survival of 88.9%). Despite the small number of patients, we found these long-term results very encouraging. CONCLUSION: ITA graft is a very good and absolutely acceptable choice in patients with severely damaged left ventricular function, particularly if we consider its long-term superiority. These pts should not be deprived of the long-term benefit of ITA graft, since early results are very good.

[History of surgical treatment of atherosclerosis of the coronary arteries--the first 100 years]. / Istorijat hirurskog lecenja aterosklerotskog oboljenja koronarnih krvnih sudova--prvih 100 godina.

Atherosclerotic coronary artery disease is the most common cause of morbidity and mortality. The incidence of cardiovascular morbidity and mortality has been doubled in our country during the period 1980 through 1996. Surgical treatment of the atherosclerotic coronary artery disease is already a century old, ever since Francois-Franck (in 1899) tried to achieve sympathetic denervation of the cervical ganglion. After the interim period of indirect myocardial revascularization, during the last 30 years, direct surgical revascularization has reached excellent early and long-term results, and became one of the most frequently performed procedures in the surgical practice. Use of arterial grafts and, introduced recently, procedures on the beating heart, minimally invasive procedures and, so called, port-access procedures became a daily routine in many centers. Surgical revascularization of the ischaemic cardiac muscle is the rapidly changing entity, along with diagnostic, technical and other improvements. We present a brief historical overview of the efforts of cardiac surgeons to combat the "disease of the century" atherosclerotic coronary artery disease.

[Occlusion of a calcified ascending aorta with a Foley catheter in aortocoronary bypass--case report]. / Okluzija kalcifikovane ascendentne aorte Foley-kateterom tokom aorto-koronarnog premoscenja--prikaz slucaja.

Heavily calcified ascending aorta predisposes to aortic injury and distal embolization during total or partial cross-clamping, during the performance of open-heart procedures. Placement of the arterial cannula may be particularly difficult, occasionally virtually impossible using the standard technique, while placing the clamp on such aorta may be extremely risky. We present a case where we have used a Foley-balloon catheter to occlude the densely calcified ascending aorta, during a aorta-coronary bypass procedure, thus completely avoiding the use of the total aortic clamp.

[Use of the internal thoracic artery in patients with stenosis of the left main branch of the coronary artery]. / Upotreba unutrasnje torakalne arterije kod bolesnika sa suenjem glavnog stabla leve koronarne arterije.

UNLABELLED: Internal thoracic artery (ITA) is the graft of choice in myocardial revascularization. However, superiority of the ITA graft in patients (pts) with left main coronary artery disease is still a matter of debate. PATIENTS: In the period from November 1986 through February 1999, ITA graft was used for myocardial revascularization in 2860 pts. Stenosis of the left main stem was present in 229 patients (8.0%); there were 39 women (17.0%) and 26 diabetics (11.4%). Severely depressed left ventricular function was present in 32 pts (14.0%), while the average age was 56.4 +/- 7.2 years. RESULTS: Operative mortality was 1.3% and postoperative morbidity was 5.2%. Average postoperative hospital stay was 7.9 days (6-29). There were no differences in analyzed parameters between patients who received ITA graft and similar group of 240 patients who received vein grafts only, during the same period of time. All 16 patients operated on in the period 1986-1992 (6-12 years follow-up) are alive. CONCLUSION: It is safe to use ITA graft for myocardial revascularization in patients with left main coronary artery stenosis. Early operative results are favorable and these patients should not be denied the benefit of the ITA graft, since long-term results are proved to be good as well.

Active infective endocarditis: low mortality associated with early surgical treatment.

BACKGROUND: Early surgical treatment is important for successful outcome in selected cases of active, either native (NVE) or prosthetic valve endocarditis (PVE). The aim of this study was to evaluate the early results of the surgical treatment of active NVE and PVE. METHODS: During a 3-yr period (January 1 1996-December 31 1998), 57 out of 60 patients (pts) with active, either NVE (46 pts) or PVE (11 pts) underwent surgical treatment. There were 11 women (23.9%), average age of the group being 43.3+/-9.1yr (18-73). They were operated on 12-35days, mean 17.7+/-7.5days (for NVE) and 5-33days, mean 13.2+/-10.1days (for PVE) after the diagnosis of endocarditis was first suspected. All pts had at least one absolute indication for early surgical treatment, the most frequent being (in NVE) worsening heart failure (19 cases) and inability to control the infection (10 cases), while in PVE it was valve dehiscence (8 cases). In 8 cases of NVE and 2 cases of PVE fresh, antibiotic sterilized aortic homograft was used to replace the aortic valve. RESULTS: Operative mortality was 1.8% (1/57) and hospital mortality 5.2% (3/57). Three pts with PVE died before they were operated on, giving an overall mortality of 10% (6/60). Postoperative morbidity included valve dehiscence in two pts (probable late onset recurrent endocarditis - 3.5%), three episodes of acute renal failure (5.3%), four cases of respiratory insufficiency (7.0%) and one chronic pleural effusion (1.8%). All pts that were discharged from the hospital (54/60), are still alive and well 1-35months postoperatively (mean 20.3+/-9.6months), including pts with recurrent endocarditis and valve dehiscence, after they were successfully reoperated. CONCLUSIONS: Along with early diagnosis and appropriate antibiotic treatment, aggressive surgical attitude is of importance for the successful outcome in this group of seriously ill patients. Our data indicate that early surgical treatment in cases of active endocarditis may be associated with low mortality and morbidity.

[Myocardial revascularization using the internal thoracic artery: pro and con]. / Revaskularizacija miokarda unutrasnjom torakalnom arterijom: "pro et contra".

Internal thoracic artery (ITA) has superior histological, physiological and pharmacological properties over the venous grafts, and it is considered to be the graft of choice for myocardial revascularization. It has low incidence of late atherosclerotic lesions, and excellent long-term patency. Usage of ITA yields improved clinical results in all subgroups of patients with coronary artery disease, including patients with poor left ventricular function (EF%), left main stenosis, diffuse coronary artery disease and octogenarians. Since superior long-term results (to be expected only 10-15 years after the operation) may be outweighed with slightly higher incidence of early morbidity and mortality, many cardiac surgeons are reluctant to use it routinely. However, this attitude is difficult to justify, since early operative results in patients that have received ITA graft are superior as well, compared to patients that have received vein grafts only.

Combined carotid and coronary artery surgery: what have we learned after 15 years?

UNLABELLED: Optimal surgical strategy in patients with concomitant coronary and carotid artery disease is debatable. We have analysed 15-years of experience (January 1981-August 1996) with 195 consecutive patients in whom we have used two different surgical approaches. Group A consisted of 48 patients who underwent a single-stage surgical procedure, and group B (147 patents) underwent a two-stage procedure, either as carotid endarterectomy followed by coronary artery bypass surgery (group B1, 97 patients), or as coronary artery bypass surgery followed by carotid endarterectomy (group B2, 50 patients). Overall, there were 40 (20.5%) patients with left main coronary artery disease, 49 (25.1%) with poor left ventricular function, 128 (65.6%) with previous myocardial infarction, 134 (68.7%) were in New York Health Authority (NYHA) functional class III or IV, and bilateral carotid involvement was present in 57 patients (29.2%). Unstable angina was more frequent in groups A and B2 (P < 0.0001), NYHA class III-IV was more frequent in group A (versus B1, P = 0.001 and versus B2, P = 0.02), low ejection fraction (EF) was more frequent in groups A and B2 (P < 0.0001 for both), bilateral carotid stenosis in groups A and B1 (P = 0.02 and P = 0.0001, respectively) and ulcerated plaque in group B1 (versus A, P = 0.0001). These differences dictated the surgical strategy, which resulted in different protocols for clinical and operative management. RESULTS: Early mortality for the entire group was 4.6% (9/195-6.2% in group A, 6.2% in group B1 and 0% in group B2, respectively P > 0.05). Serious morbidity occurred in 7.3% of patients (14/195-8.3% in group A, 7.2% in group B1 and 6% in group B, respectively P > 0.05). Univariate analysis revealed only bilateral carotid stenosis as a predictor of outcome (P = 0.04). Follow-up was completed for 156 patients (80.0%) and averaged 84.1 +/- 13.3 months (range 1-180 months). Kaplan-Meier survival estimate for the entire group was 81% and event-free survival was 76% at 5 years. Actuarial and event-free survivals were similar for all groups. Early and late outcome in these patients were influenced more by their preoperative clinical status than by the surgical strategy itself. It is therefore concluded that surgical approach should be individualized for the majority of patients.

Cardiac events after combined surgery for coronary and carotid artery disease.

OBJECTIVE: To evaluate serious cardiac events after combined (either single or two stage) coronary artery surgery (CAS) and carotid endarterectomy (CEA) for concomitant coronary and carotid artery disease. METHODS: We have analyzed our 15 year experience (January 1981-September 1996) with 201 consecutive patients operated on using both approaches. Group A consisted of 48 patients with the single-stage procedure, while in group B (153 patients), two stage procedure was carried out, either as carotid endarterectomy (CEA), followed by coronary artery bypass surgery (CAS) (group B1- 103 patients), or as CAS followed by CEA (group B2- 50 patients). Five patients from B1 group died after the CEA procedure, but were included, despite the fact they never reached the second stage. Left main coronary artery disease was found in 41 patients (20.4%), poor left ventricular function in 49 (24.4%) previous MI in 133 (66.2%), while 136 (67.7%) were in NYHA functional class III or IV. Bilateral carotid involvement was present in 61 patients (30.3%). Unstable angina was more prevalent in groups A and B2 (P < 0.0001). NYHA class III/IV in group A (versus B1, P = 0.001 and versus B2, P = 0.02), low ejection fraction in groups A and B2 (P < 0.0001), bilateral carotid stenosis in group B1 (versus A, P = 0.003 and versus B2, P < 0.0001), and ulcerated plaque in group B1 (P < 0.0001). These differences dictated the surgical strategy, which resulted in different protocols for clinical and operative management. RESULTS: Early mortality for the entire group was 5.5% (11/201) 6.2% in group A, 7.8% in group B1 and 0% in group B2, respectively; (P > 0.05). Serious morbidity occurred in 7.5% of patients (8.3% in group A, 7.8% in group B1 and 6% in group B2, respectively; P > 0.05). Univariate analysis revealed only bilateral carotid stenosis to influence early outcome (P = 0.04). CONCLUSION: Patients with concomitant coronary and carotid artery disease have relatively good immediate operative results, providing all existing lesions are corrected. Despite it did not reach the statistical significance, cardiac events were less frequent in groups A and B2 indicating possible protective effect of prior CAS in patients with concomitant disease.

[Perioperative myocardial failure and mechanical cardiac support --a five year experience]. / Perioperaciona slabost srca i mehanicka potpora radu srca--petogodnisnje iskustvo.

Inability to wean a patient from the cardiopulmonary bypass after open heart procedure is reality of the clinical practice. The only realistic chance for these patients is some form of mechanical circulatory support. Over the period from November 1988 to November 1993, in 17 patients the roller-pump mechanical assist device was inserted, i.e. 0.47% of 3589 patients were operated on during this period. Thirteen patients required mechanical circulatory support immediately after surgical procedure due to inability to wean them from cardiopulmonary bypass. In three patients the roller-pump was inserted preoperatively (percutaneous insertion), and in one patient mechanical circulatory support was started six hours after the procedure for sudden cardiac deterioration. Partial and temporary "bypass" of the damaged left ventricular function is achieved by insertion of inflow cannula into the left atrium, and outflow cannula into the ascending aorta. Depending on the inflow cannula size and volume load, we were able to achieve blood flow of 3.5 to 5 liters/minute. Using this system we were able to improve the left ventricular function in eight patients (47%), and five patients were discharged from hospital (29.4%). The roller-pump mechanical circulatory support proved to be efficient, reliable, easy to monitor and operate. Overall results are comparable to the published data as well as to other types of more versatile and costly devices for mechanical circulatory support.

[Coronary endarterectomy: has the time come for randomized evaluation of clinical research?]. / Koronární endarterektomie: nadesel jiz cas pro randomizované zhodnocení klinického významu?

The authors review contemporary and hitherto not uniform views on the clinical impact of endarterectomy in the surgical treatment of diffuse coronary disease. Exact evaluation of this problem is still lacking. The authors suggest an original, prospective project for the objective evaluation of this therapeutic method by a randomized study called PROCESS. Initial experience indicates that revascularization procedures with endarterectomy are in the early postoperative stage associated with a higher mortality and morbidity than conventional surgery using only bypasses without endarterectomy of diffusely altered coronary arteries. Hypothetically it is possible that the long-term fate of patients with more complete revascularization, i.e. with reconstruction of diffusely altered arteries, will be more favourable than the prognosis of patients with partial reconstruction of the coronary circulation. The objective of the proposed project is to test this hypothesis. This will be, however, possible only after a longer time interval.

[The importance of annulo-ventricular integrity in replacement of the mitral valve. Experience with the double-disc low profile Carbo Medics mechanical valve]. / Význam annuloventrikulárnej integrity pri náhradách mitrálnej chlopne. Skúsenosti s dvojdiskovou nízkoprofilovou mechanickou chlopnou Carbo Medics.

In the submitted paper the authors compare the results of the conventional replacement of the mitral valve with total excision of the subvalvular apparatus and the results of mitral replacement with a completely or partly preserved or reconstructed integrity of the annulopapillary structures. During the last five years the authors operated by the former method 115 patients (group A) and the second surgical method was used in 93 patients (group B). In both groups the authors compared 33 demographic, clinical, peroperative, postoperative and echocardiographic indicators. Group B comprised substantial more patients with severe myocardial disorders. In the latter group significantly more frequently a mechanical double-disc valve Carbo Medics was implanted than other types of synthetic valves which were used mostly in patients of group A. In patients of group B the operation took longer and after operation they needed more frequently intense inotropic support. Despite that their mortality on hospitalization was lower -3.2% than in group A where it was 6.9%. The late echocardiographic results were also in favour of group B where, contrary to group A, after operation the left ventricular function improved. The authors' experience support the view that preserving the integrity of the annulopapillary apparatus is nowadays one of the demands in surgical correlation of a mitral defect and is of decisive importance for the subsequent fate of the thus treated patients.

[Surgical treatment of diffuse coronary disease]. / Chirurgická lécba difúzní koronární nemoci.

In order to obtain an idea on contemporary opportunities of surgical treatment of diffuse coronary disease the authors compared the results of surgery in 103 patients whose finding called for endarterectomy and bridging of at least one coronary artery (KEA) with the results in 220 patients where it was possible to overcome all significant changes by coronary bypasses only (KBP). Patients in group KEA had more infarctions before operation than patients in group KBP. Diffuse changes of the coronary arteries were found only in patients in group KEA. All patients were operated with extracorporeal circulation and local cooling of the myocardium. Surgery took longer in patients of group KEA than in group KBP. Early mortality was higher in group KEA--4.8% than in group KBP--0.9%. This difference was not statistically significant. Early morbidity in group KEA did not differ, from the morbidity in group KBP. Using effective peroperative protection of the myocardium by local cooling, the risk of KEA is only insignificantly higher than the risk of KBP. KEA makes safe and effective revascularization of the heart muscle in patients with diffuse coronary disease possible.

[Coronary surgery in patients with severely impaired left ventricular function]. / Koronárni chirurgie u nemocných s tezce omezenou funkcí levé komory.

Views on surgical treatment of patients with coronary disease and severely restricted left ventricular function are still controversial. In the present work the authors compare the results of direct reconstruction of the coronary arteries in 184 patients with satisfactory or medium restricted left ventricular function (SLV) with a group of 77 patients with severely restricted left ventricular function (RLV). Twenty-three clinical, angiographic, peroperative and postoperative indicators were compared. Patients with RLV had more frequently a myocardial infarction before operation, on average a more restricted functional capacity and lower ejection fraction of the left ventricle than patients with SLV. The mortality during hospitalization was 1.1% in patients with SLV and 5.2% in patients with RLV. These results confirm that reconstruction of the coronary arteries is safe also in patients with a significantly restricted left ventricular function. An essential prerequisite of successful operation is perfect peroperative protection of the heart muscle by the method of continuous local cooling.

A new efficient method of topical cooling and rewarming of the myocardium.

Profound myocardial hypothermia (below 17 degrees C, and more often around 12 degrees C) is imperative in myocardial protection while the aorta is cross-clamped. Based on our experience in more than 800 open-heart operations, profound myocardial hypothermia can be achieved by very efficient topical cooling despite mild systemic hypothermia (30 to 33 degrees C) and a small, single dose of crystaloid K + cardioplegia. Very efficient topical cooling is achieved by a high flow (1 to 1(1/2) L/min) of continuously cooled fluid (+ 0.5 to + 2 degrees C). The great temperature-reducing capacity of the cooling system is due to a 10 to 15 meter long metal coil tube that is immersed in an ice-salt cold bath. The water pump placed in the bath makes heat exchange even more efficient. The described method of myocardial protection with stable profound myocardial hypothermia safely prolongs the ischemic time during operation to more than 2 hours. By repositioning the coil into the warm bath (39 to 40 degrees C), the whole system can be used for topical rewarming of the heart.

A technique of myocardial protection during aorto-coronary bypass in high-risk patients.

In the authors' opinion, profound myocardial hypothermia is imperative in myocardial protection while the aorta is cross-clamped. They based their own protection method, beside using a single dose of crystalloid cardioplegic solution, on very efficient topical cooling, by which myocardial temperature is reduced to below 15 degrees C. Very efficient topical cooling is achieved by a high flow (2 l/min) of continuously cooled fluid (0 degrees C- +2 degrees C). The great temperature-reducing capacity of the cooling system is due to 10-15 metres long metal coil tubing which is immersed in an ice-salt cold bath. The water pump placed in the bath makes heat exchange even more efficient. The described method of myocardial protection with stable profound myocardial hypothermia safely prolongs the ischaemic time during operation to more than two hours.