01 сентября 2001 00:00
Beating heart coronary surgery supported by an axial blood flow pump
Background . We have previously presented a method for performing coronary artery bypass graft operation on the beating heart without cardiopulmonary bypass (CPB). This method has now been explored.
Results . All patients went through the procedure without major complications, and were discharged from the hospital. No statistical differences were observed between the groups for time on support (HP, 60.5 minutes; CPB, 70.5 minutes) or total operating time (HP, 178 minutes; CPB, 162 minutes). The number of grafts was greater in the CPB group (HP, 1.8; range, 1 to 3; CPB, 2.5; range, 1 to 4; p = 0.03). Statistical differences were found for intraoperative bleeding (HP mean, 312 mL; CPB mean, 582 mL; p = 0.0003) and myocardial trauma as measured by postoperative
The use of coronary artery bypass grafting (CABG) supported by cardiopulmonary bypass (CPB) evolved into a practical technique during the late 1960s and has since then been the state of the art with low morbidity and mortality. There are, however, several effects related to CPB that may be of concern in certain patient groups carrying high risk   .
Beating heart CABG has been reported earlier by Buffolo and coworkers  , Benetti and associates  , and Pfister and colleagues  as an alternative to the gold standard, ie, use of CPB, aortic
Ventricular assist devices have been successfully used to support patients during CABG  . These techniques avoid the risk of CPB and an artificial oxygenator because the patient's own lungs are functioning. Sweeney and Frazier  reported good results when using ventricular assist
This report describes a prospective randomized study comparing Hemopump
Material and methods
This study was approved by the Human Ethics Committee at the University Hospital, LinkoЁping, Sweden.
Cardiopulmonary bypass group
Patients randomized to CPB had standard cannulation of the right atrium and the ascending aorta. Cold crystalloid cardioplegia (Plegisol, Abbott Laboratories, Chicago, IL), together with aortic
Heparin was given in a dose of 5,000 to 10,000 U to achieve an activated clotting time of approximately 200 seconds. A 12−mm Hemashield graft (Meadox Medical, Oakland, NJ), 15 cm long and with a diameter of 12 mm, was cut at an angle of 45 degrees at one end. This end was sutured to the ascending aorta about 5 cm distal to the sinus of Valsalva with the edge of the graft pointing toward the aortic valve. A number 31, 24F Hemopump cannula was placed through the graft into the left ventricle . [Figure 2] Satisfactory position of the pump was ascertained
As soon as the pump was inserted through the graft it was set at the lowest speed while being positioned in the left ventricle. When in the right place the speed was increased to the highest speed within a minute. A bolus
The esmolol infusion was titrated up to a dose at which the surgeon felt the heart was flaccid enough to perform bypass procedures without difficulty. Before each increase in infusion rate an additional bolus dose of 0.5
The hemodynamic response was measured before anesthesia, after induction of anesthesia,
Two different techniques were used for the vein grafts. (1) The distal anastomosis was completed first and then connected to the aorta in a standard fashion. (2) The proximal anastomosis was sutured first at the same time as the graft for the HP was placed. With this approach flow to the native coronary artery could be established as soon as each distal anastomosis was done.
In both groups blood chemistry data were obtained the day before the operation and the morning after the operation at the ICU, except
Descriptive statistics were used to summarize the data in terms of mean, median, and range. Unpaired Student's t test was used to detect differences between the groups.
In the HP group there were 4 patients with complications. One patient had to be converted to CPB because of intolerance of the <Рисунок:
In the CPB group there were 4 patients with complications. One patient experienced reversible neurologic symptoms involving the left arm. One patient had to be reoperated on because of postoperative bleeding. One patient had respiratory insufficiency requiring prolonged ventilator treatment (3 days), and one patient had respiratory insufficiency together with sternal wound infection and was transferred to the referring hospital for rehabilitation on the 12th postoperative day.
Intraoрerative data are shown in . [Table 2] Statistically, there were more grafts placed in the CPB group than in the HP group (2.5, range, 1 to 4 versus 1.8, range, 1 to 3; p = 0.03). Time on cardiac support or total operating time did not differ between the groups. Heparin doses and activated clotting times differed because of the different need for heparinization between the two methods. Intraoperative bleeding was statistically different between the groups (HP group mean, 312 mL; range, 150 to 500 mL; CPB group mean, 582 mL; range, 350 to 1150 mL; p = 0.0003). Total fluid balance, including all fluids given or lost (crystalloids, colloids, urine output, evaporation), did not differ between the groups. The average aortic
Postoperative data are shown in . [Table 3] There were no statistical differences in the time to extubation between the groups (HP mean, 6.5 hours; CPB, 29.8 hours). The median time was 6 hours compared with 10 hours. Mean time spent in the ICU was in the HP group, 1.1 days, and in the CPB group, 1.9 days; this did not differ statistically. Four patients needed inotropic support in the CPB group compared with 1 in the HP group. Length of total stay in the hospital was on average 8 days in both groups.
Blood chemistry data are shown in . [Table 4] There were no statistical differences in the levels of aspartate aminotransferase, serum creatinine, or platelets preoperatively and postoperatively between the groups. The level
Hemodynamic data are shown in . [Figure 4] There were no statistically significant differences between the two groups at the various points of measurements, apart from just after induction of anesthesia. The cardiac index at this time was on average 1.93
Since the introduction of the MIDCAB procedure, operating on the beating heart has become an alternative choice in selected patients for many thoracic surgeons. It is, however, a more demanding task to perform than the gold standard, especially if done through a very small incision. We believe that the method described in this paper constitutes an intermediate step in the process of converting classic CABG operation
Hemodynamic conditions were stable throughout the operation in our patients in the HP group, and there were no signs of ischemia on the electrocardiogram. The HP was easily inserted into the left ventricle through the graft sutured to the ascending aorta. When the HP was in the correct position it effectively unloaded the left ventricle as has been reported previously   . A concomitant reduction in wall tension should decrease the oxygen demand and increase perfusion of the subendocardial tissue  , which is beneficial for impaired left ventricles with high filling pressures. An increase in myocardial perfusion pressure and decrease in myocardial oxygen consumption during HP treatment of experimental cardiogenic shock has been reported  . In our patients, the decompressed heart was manipulated and supported with bolsters of laparotomy pads without signs of ischemia or circulatory instability. Arrhythmias were temporary provoked by these maneuvers, probably because of changes in HP position. The HP was withdrawn within 15 minutes of completion of the operation in all patients. Should there have been any heart failure or signs of ischemia we could easily have continued with the HP support in the ICU as a left ventricular assist device.
Avoidance of full heparinization is an advantage
Coronary artery bypass grafting supported by HP may be an alternative way of handling patients with ongoing ischemia or with poor ventricular function. Besides providing good myocardial protection, an effective ventricular assist device is already in place if needed. In compromised hearts, improved patient outcome may be possible because intervention is early and the heart is maintained in an unloaded state postoperatively. There are also data indicating a reduction of the size of an acute infarction when mechanical ventricular decompression is applied  .
In both groups we followed our standard clinical protocol regarding anesthesia and postoperative
The most suitable candidates for this procedure are presumably patients with impaired left ventricular function or acute ongoing ischemia, as myocardial ischemia is reduced using this technique and if the heart should fail, left ventricular assist device is already in place.
In this study,
1.Kirklin J.K.. Prospects for understanding and eliminating the deleterious effects of cardiopulmonary bypass. Ann Thorac Surg 1991;51:529−531.
2.Hammerschmidt D.E., Stroncek D.F., Bowers T.K.. Complement activation and neutropenia occurring during cardiopulmonary bypass. J Thorac Cardiovasc Surg 1981;81:370−377.
3.Buffolo E.A., Andrade J.C.S., Branco J.N.R., Aquiar L.F., Ribeiro E.E., Jatene A.D.. Myocardial revascularization without extracorporeal circulation. Eur J Cardiothorac Surg 1990;4:504−508.
4.Benetti F.J., Naselli G., Wood M., Geffner L.. Direct myocardial revascularization without extracorporeal circulation. Chest 1991;100:310−316.
5.Pfister A.J., Zaki M.S., Garcia J.M., Mispereta L.A., Corso P.J.. Coronary bypass without cardiopulmonary bypass. Ann Thorac Surg 1992;54:1085−1092.
6.Acuff T.E., Landreneau R.J., Griffith B.P., Mack M.J.. Minimally invasive coronary artery bypass grafting. Ann Thorac Surg 1996;61:135−137.
7.Calafiore A.M., Angelini G.D., Bergsland J., Salerno T.A.. Minimally invasive coronary artery bypass grafting. Ann Thorac Surg 1996;62:1545−1548.
9.Sweeney M.S., Frazier O.H.. Device supported revascularization. Ann Thorac Surg 1992;54:1065−1070.
10.LoЁnn U., Peterzeґn B., Granfeldt H.,
11.LoЁnn U., Peterzeґn B., Granfeldt H.,
12.Wampler R.K., Moise J.C., Frazier O.H., Olsen D.B.. In vivo evaluation of a peripheral
13.Frazier O.H., Wampler R.K., Duncan J.M.. First human use of the Hemopump, a catheter mounted ventricular assist device. Ann Thorac Surg 1990;49:299−304.
14.Hoffman J.I.E., Buckberg G.D.. . Transmural variation in myocardial perfusion. Progress in cardiology. Lea & Febiger,Philadelphia, 1976, 37−89.
15.Scholtz K.H., Hering J.P., SchroЁder T.. Protective effects of the Hemopump left ventricular assist device in experimental cardiogenic shock. Eur J Cardiothorac Surg 1992;6:209−214.
16.Шverum E., Holen EA, Abdelnoor M., Шystese R.. Conventional blood conservation techniques in 500 consecutive coronary artery bypass operations. Ann Thorac Surg 1991;52:500−505.
17.Von Segesser L.K., Weiss B.M., Garcia E., Gallino A., Turina M.. Reduced blood loss and transfusion requirements with low systemic heparinization. Eur J Cardiothorac Surg 1990;4:639−643.
18.Lachterman B.S., Felli P., Smalling R.W.. Improved infarct salvage by left ventricular unloading with the Hemopump immediately prior to and during perfusion after a 2−hour coronary occlusion. J Am Coll Cardiol 1991; :134A- .
01 сентября 2001 | 00:09Ишемическая болезнь сердца
Ишемическая болезнь сердца
01 сентября 2001 | 00:09Coronary artery bypass grafting with an expanded polytetrafluoroethylene graft
Coronary artery bypass grafting with an expanded polytetrafluoroethylene graft
01 сентября 2001 | 00:09Individualized surgical strategy for the reduction of stroke risk in patients undergoing coronary artery bypass grafting
Individualized surgical strategy for the reduction of stroke risk in patients undergoing coronary artery bypass grafting
01 сентября 2001 | 00:09Effect of topical vasodilators on gastroepiploic artery graft
Effect of topical vasodilators on gastroepiploic artery graft
01 сентября 2001 | 00:09Myocardial revascularization with the left internal thoracic artery Y graft configuration
Myocardial revascularization with the left internal thoracic artery Y graft configuration