[Repeated Coronary Artery Bypass Surgery 18 Years After the Primary Revascularization of Myocardium in a Patient With Acute Coronary Syndrome Without the Segment ST Elevation].

This article describes a clinical case of successful repeated coronary bypass grafting 18 years after the initial surgery in a patient with non-ST-elevation acute coronary syndrome.

[Method of optimal hydraulic dilatation of venous conduits for coronary artery bypass grafting]. / Sposob optimal'noi gidravlicheskoi dilatatsii venoznykh konduitov dlia aortokoronarnogo shuntirovaniia.

Hydraulic dilatation is used in everyday cardiac surgical practice for assessment of leak-proofness and prevention of spasm of autovenous shunts. The classical technique envisages manual high-pressure solution injection, which exerts a negative effect on venous conduits and is one of the causes of incompetence of shunts in the postoperative period. Limiting pressure during hydraulic dilatation is necessary to minimize morphological changes and preserve functional viability of venous conduits. The purpose of the present study was to develop and assess efficacy of a standardized methodology of controlled hydraulic dilatation of venous conduits. We worked out an original technique of controlled hydraulic dilatation of venous conduits under perfusion pressure of artificial circulation. This was followed by assessing morphological changes and functional viability of venous segments after controlled hydraulic dilatation as compared with veins after conventional uncontrolled hydraulic dilatation and the control intact veins. Uncontrolled hydraulic dilatation was accompanied by endothelial damage (p<0.05), multiple conduit wall tears (p<0.05) according to the findings of light microscopy, leading to a significant decrease in the functional vitality of the venous conduit (a decreased reaction to hyperpotassium solution, phenylephrine, acetylcholine and sodium nitroprusside (p<0.05) according to the findings of biophysical examination. Our original technique of controlled hydraulic dilatation of venous conduits under perfusion pressure of artificial circulation made it possible not only to evaluate leak-proofness of the vessel but also to achieve comparable to the control segments parameters of structural integrity of the venous wall and functional viability of the conduit. Thus, using the developed method of controlled hydraulic dilatation makes it possible to minimize morphofunctional alterations in venous conduits, influencing the function of autovenous shunts.

[Role of intraoperative flowmetric assessment of coronary artery bypass grafts established on-pump]. / Rol' floumetricheskoi otsenki koronarnykh shuntov na ostanovlennom serdtse.

AIM: This study was undertaken to evaluate the efficacy of three-stage measurement of the transit-time flow through coronary bypass grafts with the help of flowmetry for early verification of technical errors during on-pump coronary artery bypass graft surgery. PATIENTS AND METHODS: We performed an intraoperative analysis of 214 bypass grafts with the help of three-stage flowmetry. The first stage of measuring was performed on-pump with and without the proximal loop test, the second stage of measurement was performed after weaning the patient off the heart-lung machine, and the third stage of measurement was carried out after heparin inactivation prior to chest wound closure. RESULTS: Amongst the 214 transplants regarded as functioning, intraoperative flowmetry revealed insufficient blood flow in 9 (4.2%) cases. Technical surgical errors were confirmed in these shunts during revision thereof. In 6 (2.8%) of the 9 such grafts we detected non-optimal parameters of flowmetry during the first measurement (while the heart was stopped); of these, in 5 (2.3%) cases non-optimal blood flow was verified with the use of the proximal loop test on the target coronary artery and in 1 (0.47%) case without it. In another one (0.47%) of the nine such transplants, inadequate blood flow was revealed during the second measurement, which confirmed technical errors in proximal anastomoses. In a further 2 (0.93%) of the 9 such transplants we observed low parameters of blood flow during the third measurement, which was related to kinking of the shunts due to their excessive length. All surgical errors were corrected immediately at the stage of verification thereof. CONCLUSION: The strategy of three-stage assessment of flowmetry makes it possible to ensure and confirm adequate functionality of coronary artery bypass grafts at all stages of the operation, thus allowing timely verification and immediate correction of any technical problems with coronary artery bypass grafts.

[Blood loss control during endoscopic vein harvesting for myocardial revascularization in patients with acute coronary syndrome]. / Kontrol' krovopoteri pri éndoskopii ven pri revaskuliarizatsii miokarda u patsientov s ostrym koronarnym sindromom.

From 5 to 10% of patients presenting with acute coronary syndrome and receiving dual antiplatelet therapy require surgical myocardial revascularization. Dual antiplatelet therapy considerably increases the risk of surgical bleeding. Endoscopic harvesting of the great saphenous vein is a technique that can make it possible to decrease the injury and to minimize blood loss. The study included a total of 32 patients presenting with acute coronary syndrome and undergoing coronary artery bypass grafting. They were subdivided into two groups: Group One (study group) was composed of 17 patients subjected to endoscopic harvesting of the great saphenous vein in the flap. Group Two (comparison group) consisted of 15 patients undergoing an open technique of harvesting of the vein in the flap. During the entire perioperative period, the amount of discharge through drainages from the mediastinum did not differ significantly (958±173 ml for Group One patients and 1005±165 ml for Group Two patients, p=0.47). The amount of discharge from the bed of the great saphenous vein on the lower extremities in Group One patients turned out to be less than in Group Two patients (443±37 ml vs. 570±77 ml, p=0.04). A higher haemoglobin content in the total blood count was observed in the postoperative period in the Study Group patients (90±30 g/l vs. 74±21 g/l, respectively, p=0.03). The necessity to use donor blood preparations in Group One patients turned out to be less (transfusion of erythrocytic mass 0 and 2 (0; 2) doses, p=0.001; fresh frozen plasma 2 (0; 3) and 5 (3; 8) doses, respectively, p=0.0001). The duration of hospital stay amounted to 8±1.1 days in the study group and to 15±4.5 days in the comparison group (p<0.0001). Hence, this approach makes it possible to control blood loss in high-risk patients undergoing coronary artery bypass grafting on the background of dual antiplatelet therapy, to decrease the amount of donor blood, and to reduce the length of hospital stay.

[Successful experience in the correction of post-infarction ventricular septal defect].

Rupture of the interventricular septum (MVP) as a complication of acute myocardial infarction is a rare event and associated with high mortality without timely surgical treatment. We present a case of a 68-year-old patient who had an acute myocardial infarc­ tion with ST-segment elevation complicated by a rupture of MVP. In this article we discusse the difficulties of patient management with this pathology and the problem of choice of treatment tactics.

[Functionality of mammary-coronary bypass grafts according to the data of intraoperative flowmetry]. / Funktsional'nost' mammarokoronarnykh shuntov po dannym intraoperatsionnoi floumetrii.

Improvement of surgical treatment for ischaemic heart disease is one of the main trends in modern medicine. After the operation of coronary bypass grafting, further functioning of blood flow in the grafts largely depends upon its domination over the native blood flow in the target coronary arteries. Therefore, intraoperative diagnosis of functional competence of coronary bypass grafts by means of flowmetry is currently of special importance. The purpose of this study was flowmetric quantitative assessment of the curves of blood flow through the coronary bypass grafts, depending on the degree of stenosis of the target coronary arteries. A total of 135 patients were examined during our study. We evaluated the curves of blood flow through the bypass grafts from the left internal thoracic artery to the anterior descending artery. The bypass grafts were divided into three groups: the 1st group (n=47) with moderate stenosis of the coronary arteries (from 50 to 75%); the 2nd group (n=42) with a more pronounced lesion of the target vessel (from 75 to 99%), and the 3rd group (n = 46) with occluded coronary arteries (100%). It was revealed that the flow rate (Q, ml/min) in group one was lower (17±3.1) than in group two (33±5.3) and group three (45±3.4). Also, differences were revealed in the resistance index of the grafts: it turned out to be higher in group one (5.2±1.1) and group two (4.5±0.9) as compared with group three (1.8±0.5). However, there was no between-group difference in diastolic filling of the grafts, which amounted to 58±13, 61±10 and 64±9% for groups one, two and three, respectively. By the shape of the curve, we assessed the reverse systolic peak whose presence prevailed in the grafts of group one (15 of 47; 31.9%) and group two (11 of 42; 26.2%) as compared with that in the grafts of group three (5 of 46; 10.8%). The obtained findings confirm higher frequency of the presence of competitive blood flow in the grafts used on non-occluded coronary arteries.

[A new method of endoscopic harvesting of the great saphenous vein in an open system]. / Novyi metod éndoskopicheskogo vydeleniia bol'shoi podkozhnoi veny v otkrytoi sisteme.

We examined a total of 246 patients subjected to coronary artery bypass grafting with the use of the great saphenous vein (GSV). The patients were subdivided into two groups. Group One (n=121) patients endured procurement of the great saphenous vein by a new endoscopic technique in an open system with the help of the equipment Karl Storz and electric dissector Ligasure. In Group Two (n=125) patients the vein was harvested by means of the traditional open method. In all patients we evaluated complications in the early postoperative period 13±2.5 days after the operation. The rate of relapsing angina pectoris in both Groups turned out to be low and did not differ (1.65% in Group One and 1.6% in Group Two). Patients of the both groups differed significantly by the incidence of postoperative complications on the lower limbs in the zone of procurement of the GSV (9.09% in Group One and 26.4% in Group Two, p=0.131). Group Two patients (open method of procurement of the GSV) were considerably more often found to have developed cases of lymphorrhoea, haematomas, disjunction of the sutures (21.6%) compared with Group One (endoscopic method) patients (3.3%) (p=0.167), which in 10.4% of cases required secondary surgical debridement of wounds in patients after the open harvest of the GSV. Eventually, the length of hospital stay for Group Two patients increased significantly (15 ± 4.5 days) compared with Group One patients (8±1.1 days) (p=0.361). Hence, the endoscopic method of harvesting the GSV in the open CO2 system makes it possible to obtain a good cosmetic effect on the lower limbs after the operation, to considerably decrease the complications rate, thus reducing the length of hospital stay.

[Bilateral Internal Mammary Grafts With Preservation of Sternum Blood Supply].

We have prospectively collected data from 43 patients who underwent coronary artery bypass surgery and received bilateral internal thoracic artery (ITA) graft. Left ITA was harvested on full length from ostium to bifurcation. Right ITA harvesting included mobilization of only its proximal stump (5-6 cm long), that allowed its distal segment to remain intact. Proximal stump of right ITA was lengthened by radial artery or large subcutaneous vein grafts in order to reach various parts of coronary vascular bed. After comparative intraoperative manometry of ante- and retrograde pressures in right ITA patients were divided into two groups. In group 1patients (n=28) difference between ante- and retrograde systolic pressure (112.5+/-17.4 and 92.4+/-19.6 mm Hg, respectively) was <30%; in group 2 patients (n=15) difference between ante- and retrograde pressure (110.2+/-14.1 and 68.9+/-12.3 mm Hg, respectively) was more or equal 30%. Lower limb and carotid (arteries stenotic lesions (stenosis >60-70%) were more frequent in group 2 (n=8; 18.6%) than in group 1 (n=4; 9%). However postoperative ultrasound study detected no significant differences between two groups in systolic retrograde blood flow velocity in intact portion of right ITA (29.8+/-8.7 and 23.1+/-8.0 cm/s, respectively, p>0.05). Absence of sternal wound healing complications confirmed efficacy of sternal retrograde blood supply through lower and upper epigastric arteries. Patency rate of composite grafts according to angiography (n=19) performed in 3+/-0.8 years after surgery was high (94.7%). Our data confirm high functionality of bilateral ITA grafts with preservation of sternal supply.

[Policy of using the right internal thoracic artery "in situ" for coronary artery bypass grafting].

The authors analysed the outcomes in a total of 73 patients subjected to coronary artery bypass grafting with the use of the "in situ" the right internal thoracic artery. Of these, 14 patients endured bypass grafting with assessment of the conformity of the length of the "in situ" right ITA as a conduit for the distal third of the right coronary artery (RCA). 16 patients underwent grafting of the RITA "in situ" with the RCA by passing through the pleural cavity. The remaining 43 patients were subjected to bilateral mammary composite bypass grafting using the radial artery (RA). A total of 22 segments of the RA were subjected to a comparative morphometric examination depending on the method of exposure. We additionally analysed 56 cases of utilizing the RA with the use of the pharmacological protocol of preventing spasm. The results were regarded statistically significant if p<0.05. We used the non-parametric criterion of Mann-Whitney. The obtained results showed that the right ITA "in situ" may be used for bypass grafting of the RCA system, excluding the risk of graft tension, if the perpendicular from the 6th intercostal space crosses the sharp edge of the heart 1.5-2 cm distal to the medial point, with the minimum number of complications after 1.5±0.3 years (7.1%). When the above-mentioned perpendicular is located proximal to the middle point of the sharp edge of the heart it is possible to use the right ITA "in situ" for the RCA system thanks to passing the conduit through the right pleural cavity under the anterior segment of the upper lobe and the medial segment of the middle lobe of the right lung with no complications after 1 year. The method of composite bypass grafting by means of the proximal segment of the right ITA "in situ" and the RA makes it possible to effectively revascularize any portions of the coronary bed (latency 94.7% after 3.0±0.8 years), to avoid manipulations on the aorta, and to save the bed of the right ITA in the middle and distal third of the sternum with no postoperative complications. It was revealed that in the conditions of decreased osmotic pressure the increase in the thickness of the vascular wall is more pronounced in the skeletonized segments of the RA (1.38±0.05 mm) as compared with the segments surrounded by connective and fatty tissue (1.09±0.04 mm). The pharmacological protocol for prevention of radial artery spasm used in 56 patients resulted in a small number of complications observed after 3.0±0.8 years (myocardial infarctions - 1.75%, angina pectoris relapse - 7%). Hence, the developed methods of using the right ITA "in situ" widen possibilities of bilateral mammary bypass grafting, excluding the existing problems of routine use of the both ITAs "in situ".

[Fasciotomy as a method of surgical preparation of a conduit for coronary artery bypass grafting].

The study included a total of 59 patients undergoing coronary artery bypass grafting with the use of the radial artery (RA). Group One consisted of 28 patients who while preparing the conduit were subjected to longitudinal dissection of the fascial compartment (fasciotomy) of the RA. Group Two comprised 31 patients not undergoing fasciotomy. In Group One patients prior to fasciotomy, 2 segments were cut off from each RA and incubated in a hypo osmotic solution either in the fascial compartment (n=28) or after fasciotomy (n=28) followed by morphometric analysis. Therapeutic results in all patients were studied averagely 3.3 ± 0.8 years after surgery. 32 patients underwent control coronary bypass angiography averagely 2.5 ± 0.54 years after the operation. The morphometric analysis of the RA segments in conditions of simulated oedema revealed that a more pronounced decrease in the RA lumen (by 49.7%) was observed in the segments kept in the fascial compartment as compared with the segments after fasciotomy (1.08 ± 0.12 mm and 2.21 ± 0.09 mm, respectively, p=0.0129). In the remote period after the operation (mean 3.3 ± 0.8 years) Group One patients were found to have fewer cases of renewal and increase of the angina class (n=3; 10.7%) than Group Two patients (n=7; 22.5%; p=0.0289). There were no cases of secondary myocardial infarction in Group One patients, whereas in Group Two there were 2 (6.5%) cases of myocardial infarction in the postoperative period. Based on the findings of coronary bypass angiography, patency of the RA in Group 1 was higher than in Group 2 (91.6 and 78.6%, respectively; p=0.0371). The obtained results are suggestive that fasciotomy of the RA during surgical preparation of the conduit is appropriate, thus decreasing the risk of blood flow reduction via the arterial bypass graft and improving the outcomes of autoarterial coronary bypass grafting.

[In vitro study of the radial artery vasodilatory reactions].

The aim of the study was to investigate comparative contractility of isolated radial artery segments (n = 50). Phosphodiesterase inhibitor (papaverine) was used in 15 segments; dihydropyridine calcium channel antagonist (adalat) was used in 12 segments; calmodulin inhibitor (aminazine) was used in 13 segments; and "nitromixture" (5 mg verapamil hydrochloride, 2.5 mg nitroglycerine, 500-UN heparin, and 300 mL isosmotic Krebs solution) was used in 10 segments. Effect of hyposmotic solution for the morphometric properties of radial artery was analyzed in 22 arterial segments. The data didn't show statistical differences between drugs: "nitromixture" decreased tone by 100 ± 2% (n = 10), papaverine by 100 ± 11% (n = 15), adalat by 95 ± 6.1% (n = 12) and aminazine by 92 ± 11.3% (n = 13) (p > 0.05). The most effective drug in duration was adalat (n = 12, 90 ± 6.5 minutes) versus "nitromixture" (n = 10, 60 ± 9.3 minutes), papaverine (n = 15, 60 ± 4.3 minutes) and aminazine (n = 13, 50 ± 3.2 minutes) (p < 0.05).