Results of Coronary Bypass grafting in Treatment ... - Semantic Scholar

Results of Coronary Bypass Grafting in Treatment of Left Main Stenosis

Results of Coronary Bypass Grafting in Treatment of Left Main Stenosis Alen Karic1, Emir Mujanovic2, Amela Karic3, Zoran Jerkic1, Jacob Bergsland2, Emir Kabil2 Clinic of Cardiovascular Diseases, University Clinical Center Tuzla, Bosnia and Herzegovina1 Center for Heart, Tuzla, Bosnia and Herzegovina2 Department of Biology, Faculty of Natural Sciences and Mathematics, University of Tuzla, Bosnia and Herzegovina3 Original paper SUMMARY

Study comparing the results of coronary artery bypass grafting (CABG) with and without cardiopulmonary bypass (CPB) in the treatment of left main stenosis (LMS) has not yet been made in Bosnia and Herzegovina. The main aim of this study was to compare result of CABG performed on 176 patients, in Cardiovacular clinic of University Clinical Center in Tuzla from May 1999 to January 2005, by these two methods in LMS group of patients in the early and late postoperative period. The study was divided in two parts. In the first part, early postoperative period (30 days after the surgery) has been analysed, which encompasses results of CABG in 92 patients revascularisied without CPB (OPCAB) method (Group A), and 84 patients with LMS revascularisied with CPB method (ONCAB, CCAB) (Group B). In the second part, late postoperative period (one year after surgery) has been analysed. Patients from both groups were contacted and interviewed. Total number (276 versus 278), same as average number of grafts per patients (3.0 ±1.45 versus 3,31 ±0.86 p=0.096), was insignificantly higher in group B. Perioperative and postoperative results revealed significant differences between two groups in reduced mechanical ventilation time (2.9 versus 7.3 hours, p=0.039), less blood transfusion requirement (200.3 versus 419.9 ml, p=0.035) and postoperative length of stay (7.4 versus 8.3 days). Inotrop support requirement was significantly higher in group B during the surgery (14.1% versus 29.8%, p=0.019) and postoperative period longer than 12 hours (7.6 versus 22.6%; p=0.009). Significant difference for mortality was noticed in early postoperative period in group A (0.0 versus 5.95%, p=0.023). There was no significant difference for any of additional procedures (7.9 versus 7.8, p=0.802), for major complications (8.0 versus 9.1%; p=0.985) or for mortality (7.9 versus 5.2%; p=0.692). Patients’ survival after CABG for period of 12, 24, 36 and 48 months after surgery was not statistically significant (97.0 versus 96.1%, p= 0.802; 95.5 versus 96.1%, p=0.857; 93.2 versus 94.8%, p=0.913; 92.0 versus 94.8%, p= 0.692). This study revealed that OPCAB is effective and safe method for treatment of LMS, and there are certain advantages in comparison to classical method in short term follow up, with no difference in long term results. Keywords: coronary artery bypass grafting, LMS, early results of coronary artery bypass grafting, late results of coronary artery bypass grafting

1. INTRODUCTION Despite the fact that the results of numerous studies published in the literature in recent years speak of the clinical, angiography and economic superiority of coronary arterial bypass grafting (CABG) without cardio-pulmonary bypass (CPB)–(OPCAB) compared to the classical method with the use of CPB (ONCAB) (1, 2, 3) there is a large number of authors who say that most of these studies analyzed the low-risk patients, and that the for the good results obtained in these the major credit goes to this fact (4). Patients with significant stenosis (≥ 50%) of the main branch of the left coronary artery (left main stenosis-LMS) are under high risk for CABG (5, 6). LMS in addition to a standard indication for CABG (7), is identified as one of the main predictors of postoperative morbidity and mortality and thus operational risk in such patients multiply increases (8). Previous CABG results in the treatment of LMS are bur328

dened with a high rate of morbidity and mortality (9), which prompted cardio surgery to explore applicability of OPCAB surgery in the treatment of these patients (10). The presence of LMS was for years considered as relative contraindications for OPCAB, primarily due to the hemodynamic changes that occur during movement and exposure of the heart. Reduced tolerance to manipulation of the heart in patients with LMS has restricted the use of this method in this specific high-risk group (11). However, the evolution of the methods, especially the improvement of technical aids and maneuvers as well as improved surgical and anesthesiology techniques has led to situation that this operation become technically easier and safer (12). With increasing security of the method and experience of the cardiac surgeons created the preconditions for the treatment of high-risk patients, such as those suffering from the LMS. Shortly after that started publishing of the results of

MED ARH 2009; 63(6) • Original papers

first study with encouraging results of OPCAB application in the treatment of this group of patients (13). Unfortunately, the number of such studies is still very small compared with those which pose doubt on short and longterm results obtained by this method.

2. GOALS Compare the early results of CABG in subjects with LM stenosis made with and without CPB (the duration of surgery, amount of postoperative bleeding in thoracic drainage and the amount of received blood transfusion, the time spent on the respirator, the time spent in the intensive care unit, basic postoperative complications and the total duration of hospitalization). Compare the late results of CABG in subjects with LM stenosis made with and without CPB (recurrent angina pain, myocardial infarction, repeated catheterization, percutaneous coronary intervention, repeated CABG, death due to cardiac causes). 3. SAMPLE AND METHODOLOGY 3.1. Sample

The study was conducted in two parts. The first part included the period from surgery until one month after surgical treatment while the second part included the late post-surgical period after the first year of surgical treatment. The first part of the study included 176 patients with LMS > 50% undergoing CABG in the Clinic of Cardiovascular Diseases, University Clinical Center Tuzla in the period from May 1999 until January 2005. Respondents were divided into two groups. In group A were 92 subjects operated with OPCAB method, and in group B there was 84 subjects operated with ONCAB method. All respondents were similar according to gender, age, values of ejection factions and ERUOSCORE, risk factors before the surgery and the number of bypass grafts. The second part of the study included all patients from both groups that were followed in the late postoperative period. A total of 165 respondents was followed, of whom 88 (95.7%) from group A and 77 (91.7%) from group B. The main source of data from the early postoperative period was the computer database, and the standard patient’s records, while data from the late postop-


erative period is obtained by telephone survey with each respondent. 3.2. Methods

The standard approach for OPCAB was a medial sternotomy. To achieve adequate exposure LIMA stitch was used (14). The left front descending artery (left anterior descending-LAD) artery was the first for grafting then followed by grafting of other coronary arteries. The problem of local myocardial stabilization was solved using the CTS stabilizer (CTS, Cupertino, CA, USA). After exposure, stabilization and preparation of coronary blood vessel started the creation of anastomosis. Proximal from the point of anastomosis, a loop around blood vessel is made with a 4-0 prolene “pladget” suture, then intraluminar is applied intracoronary shunt and distal anastomosis was created. Then was placed a partial clamp on an ascendant aorta and proximal anastomosis is created. After that started the Transit time flow (TTFM) measurements. After the obtained satisfactory values of the flow surgery was completed in usual manner. The standard approach for ONCAB was also medial sternotomy. Followed by canulation of ascendant aorta and right atrium, and then establishment of CPB. After clamping of ascendant aorta to stop the heart used was intermittent normotehermal blood cardioplegic solution which is applied in anterograde or retrograde way, with the local ap-

plication of ice. Left front descendent artery (LAD) was the last for grafting. After creating the distal anastomosis and a stopped hearth, the heart gradually warms up to the establishment of a normal heart rhythm (with or without defibrillator). Upon removal aortic cross clamps placed was a partial clamp on ascendant aorta and created proximal anastomosis in the previously described manner. Upon completion of proximal anastomosis further procedures were identical as in the previously described method. 3.3. Verification of bypass grafts quality during surgery

In both groups after the completion of the proximal anastomosis access is the quality and verification of bypass grafts with transit time flow measurement method (TTFM). Machine used to measure TTFM was MediStim BF2004 (MediStim, Oslo, Norway). All measurements were performed in standardized hemodynamic conditions: systolic blood pressure in the range of 100-120 mmHg, heart rate ranges from 80-100 beats per minute. Recorded and printed are best TTFM measurements for each graft. In the event of unsatisfactory findings TTFM anastomosis was revised. 3.4. Early post-surgical period

In the early post surgery period (one month from the date of surgery) in both investigated groups were analyzed and compared: the total duration of surgery, time spent on Group A Group B p the respiraValue SD Value SD tor, the time Duration of surgery 326.6 ±73.4 325.9 ±63.8 =0.949 spent in the (minutes) intensive care Respirator (hours) 2.9 ±3.1 7.3 ±19.6 =0.039 u n it (IC U), Stay in ICU (days) 1.5 ±1.2 2.1 ±3.9 =0.178 the amount Bleeding (ml) 722.2 ±289.5 875.9 ±1349.1 =0.313 of postoperaBlood transfusion (ml) 200.3 ±364.4 419.9 ±832.7 =0.035 tive bleeding Duration of 7.4 ±1.3 8.3 ±3.6 =0.019 i n t horacic hospitalization (days) drainage, the Table 1. Results before and during surgery, ICU-intensive care unit amount of blood transfusions, priGroup A Group B p ma r y postN % N % operative Bleeding – repeated 2 2.2 4 4.8 =0.597 c o m p l i c a surgery Myocardial infarction 2 2.2 3 3.5 =0.918 tions (bleedRhythm disorders 22 23.9 27 32.1 =0.295 ing, repeated CVI 1 1.1 5 5.9 =0.174 surgery, myoDeep wound infection 3 3.3 3 3.6 =0.762 c a rd i a l i nIABP 1 1.1 3 3.6 =0.549 f a r c t i o n , rhythm disTable 2. Complications after surgery, IABP-intra aortal balloon pump order, cere-

brovacular insult, deep wound infections, insertion of itra-aortic balloon pump) and their frequency, duration of hospitalization). 3.5. Late post-surgical period

In the late post operative period (after one year from surgery) in both groups investigated and analyzed are the frequency of occurrence of: repeated angina problems, myocardial infarction, cerebrovascular insult, death due to cardiac etiology, the need for repeated coronography, the need for percutaneous coronary intervention (percutaneous coronary angioplasty and stent), the need for repeated CABG.

4. RESULTS In both analyzed groups there weren’t any significant differences between the average values of age, and ejection fractions EUROSCORE. The total number (276 vs. 278) and the average number of bypass grafts (3.00 ± 1:45 versus 3.31 ± 0.86) was higher in group B but without statistical significance (p = 0.091). The frequency of revisions of bypass grafts based on TTFM findings was higher in group A, but without statistical significance compared to group B (5.1 vs. 4.1%, p = 0.820). Analysis of basic results before and after the surgery indicate significant differences between groups in time spent on the respirator (2.9 versus 7.3 hours, p = 0.039), the amount of received blood transfusion (200.3 versus 419.9 ml, p = 0.035) and duration of hospitalization (7.4 versus 8.3 days, p = 0.0019) (Table 1). There were no statistically significant differences between groups in the incidence of post operative complications. The most common post operative complication was the atrial fibrillation type of rhythm disorder (23.9 vs. 32.1%, p = 0.295) (Table 2). Analysis of the frequency of lethal outcomes in both groups showed a significantly lower mortality in group A (0.0 versus 5.95%, p = 0.023) (Table 3). In the late postoperative period (one year after the surgery) a statistically significant differences are not recorded between the investigated groups in the frequency of recurrent angina pectoris (25.0 vs. 31.2%, p = 0.479). Analysis of subsequent procedures in both groups showed that there was somewhat more coronography after CABG in group A (6.8 vs. 5.2%, p = 0.917), one repeated PTCA and CABG revascularization in


329


sults obtained by this study also included respondents from method. the early stages of the learning curve of Since its introOPCAB method. Cardiogenic shock =0.226 Analysis of basic peri operative and Thromboembolizm =0.226 duction into surgipost operative results from this study MOF =0.477 cal practice OPCAB indicate significant differences between Total =0.023 method is connected to somewhat lower groups in time spent on the respirator, Table 3. Mortality and its causes, MOF-Multiple organ failure average number of the amount of received blood transfubypass grafts per pasion and duration of hospitalization, Group A Group B p Causes tient (20, 21), which while other parameters did not show N % N % according to some significant differences. While most auCardiogenic shock 5 5.7 2 2.6 =0.553 authors refer to the thors dealing with this issue agree that Thromboembolizm 1 1.1 1 1.3 =0.531 incomplete revasthe compensation of blood in post opMOF 1 1.1 1 1.3 =0.531 cularization and the erative period is significantly lower with Total 7 7.9 4 5.2 =0.692 possibility of more OPCAB method (17, 19), there are many Table 4. Mortality and its causes during late post operative period, frequent postoperadiverse data on the duration of hospiMOF-Multiple organ failure tive complications. talization. While Buffolo et all, 1985 reHowever, the imported significantly shorter hospitalizagroup B (0.0 vs. 1.3%, p = 0.946, 0.0 vs. provement of technical aids and surtion in OPCAB group (7 vs. 11 days) as 1.3%, p = 0.946) and one STENT progeons experience very quickly led to it was the case in this study (7.4 vs. 8.3 cedure for the right coronary artery in a significant increase in the number days), Dewey et all, 2001 reported insiggroup A (1.1 vs. 0.0%, p = 0.946) but grafts made with OPCAB method as is nificant difference between the groups without statistical significance. Comthe case in this study: the average numwith the fact that the hospitalization parative analysis of the most serious ber of bypass grafts was not statistically after ONCAB was shorter (7.8 vs. 7.2 complications without lethal outcome different between groups. days). Probable explanation for these showed that the most common compliDoubt in the quality of distal anastocontradictory statements is primarily cations in both groups was myocardial mosis and bypass grafts made with this because of difference in the experience Survived infarction (5.7 vs. 5.2%, p = 0.837) and Censored method is the most common reason for of that particular group of surgeons in cerebrovascular insult (2.3 vs. 3.9%, p = skepticism in OPCAB (22). One indicathe practice of OPCAB method. 0.880) but without statistically signifitor of the quality of distal anastomoAnalysis of the incidence of post opcant differences. Comparative analysis sis is the number intra operative revierative complications in both groups inof total mortality in the late post opersions of made ative period between the two groups of bypass grafts, Survived patients showed no statistically signifiaf ter TTMF Censored cant difference (7.9 vs. 5.2%, p = 0.692). method finds The most common cause of death in i t ’s i n a d e both groups was cardiogenic shock but quate. The rewithout statistically significant differsults of this Months after surgery ences between groups (5.7 vs. 2.6%, p study showed = 0.553). Comparative study of patient that the fre- Figure 1. Kaplan-Meier survival curve for group A patients survival after CABG in periods of 12, quency of re24, 36 and 48 months points to the difvised bypass ference between the groups, without grafts based statistical significance (97.0 vs. 96.1%, p on TTFM is = 0.802, 95.5 vs. 96.1%, p = 0.857, 93.2 Months after surgery not statistivs. 04.8%, p = 0.913, 92.0 vs. 94.8%, p = Figure 1. Kaplan-Meier survival forfor group A patients Figure 1. Kaplan-Meier survivalcurve curve group A patients cally dif fer0.692) (Figure 1 and Figure 2) ent between Survived groups. Com5. DISCUSSION Censored parative analLately, though still sporadic, studysis of the ies occur that report encouraging prenumber of liminary results of OPCAB method in respondents treatment of patients with LMS (15, 16, with a revised 17, 18). Although they show methods as Survived bypass grafts equal, and in some parameters the suCensored in both groups periority of OPCAB compared to ONindicate insigCAB method, a small number of bynificant difpass grafts made with this method as ferences bewell as the suspicion of their inferior tween groups, Months after surgery quality (19), imply the suspicion also in d e s p it e t he worse early and late postoperative reFigure 2.Kaplan-Meier Kaplan-Meier survival curve forfor group B patients survival curve group B patients fact that this Figure2. Causes

330

Group A N % 0 0.0 0 0.0 0 0.0 0 0.0

Group B N % 2 2.38 2 2.38 1 1.19 5 5.95

p


Months after surgery


dicates the tendency of a small number of them in the OPCAB group, but without statistically significant differences for any of the listed complications. The biggest difference in incidence was observed in CVI (1.1 vs. 5.1%, p = 0.174). Similar statements are made by John Lu et al, 2005 who also showed a lower incidence of CVI in the OPCAB group (0.4 vs. 2.2%, p = 0.088). Buffolo et all in 1990 also pointed to a lower incidence of neurological and respiratory complications in OPCAB group, and they conclude that it was primarily consequence of CPB use. Although most studies that analyzed mortality in patients with LMS does not indicate significant differences between groups (17, 18, 19), the results of this study suggest a significantly lower mortality in the OPCAB group (0.0 versus 5.95%, p = 0.023). Similar results are found by Taggart et all, 2006 which show the mortality rate of only 1.1% out of 1225 patients with LMS surgically treated with OPCAB method. Probably for the good results obtained in both studies is primarily responsible large clinical experience in performing this type of surgeries. Analysis of the results obtained in the late post operative period showed no statistically significant differences between the investigated groups in frequency of occurrence of recurrent angina pectoris, as well as the need for subsequent procedures. The same trend was observed with major complications without lethal outcome. It was noted that the most common complications in both groups was myocardial infarction (5.7 vs. 5.2%) but without statistically significant difference in frequency between the groups (p = 0.837). Also, analysis of total mortality in the late post operative period between the two groups of patients did not show statistically significant difference (7.9 vs. 5.2%, p = 0.692). Kaplan-Meier analysis of the survival curves (Figure 1 and Figure 2) showed that there was no significant difference in survival of the respondents in the late post operative period. Lethal outcomes at intervals of 30 days, 1 year and 2 years after CABG was not significantly different between groups, which is another argument that speaks in favor of equally good results obtained by the OPCAB method.

6. CONCLUSION The results of this study suggest that OPCAB is safe and effective method in the treatment of LMS, associated with a number of advantages in comparison with the classical method, and not worse long-term results. Ideally, the conclusions of this research are to increase the proportion of OPCAB in the daily treatment of these patients.

12.

13.

14.

REFERENCES

1.

Puskas JD, Thourani V, Marshall J. et all. Clinical outcomes, angiographic patency, and resource utilization in 200 consecutive Off-pump coronyry bypass patients. Ann Thorac Surg, 2001; 71: 1477-84. 2. Ancona G, Karamanoukian H, Ricci M, Tang L, Salerno T, Bergsland J. Myocardial revascularisation on the beating heart in high risk patients. In Salerno T, Bergslan J (ed): Beating heart coronary artery surgery. Armonk, NY, Futura Publishing Company, 2001: 217-33. 3. Calafiore AM, Giammarco G, Teodori G, Mazzei V, Vitola G. Recent Advances in Multivessel Coronary Grafting Withouth Cardiopulmonary bypass. Heart Surgery Forum, 1998; 11: 589-600. 4. Riha M, Danzmayr M, Nagele G. et all. Off pump coronary artery bypass grafting in EuroSCORE high and low risk patients. Eur Cardiothorac Surg, 2002; 21: 193-8. 5. Kouchoukos NT, Oberman A, Kirklin JW. Coronary bypass surgery: analysis of factors affecting hospital mortality. Circulation, 1980; 62(Suppl 1): 84-9. 6. Kennedy JW, Kaiser GC, Fisher LD, Maynard C, Fritz JK, Myers W, Mudd JG, Ryan TJ, Coggin J. Multivariate discriminant analysis of the clinical and angiographic predictors of operative mortality from the Collaborative Study in Coronary Artery Surgery (CASS). J Thorac Cardiovasc Surg, 1980; 80(6): 876-87. 7. C a rraciolo E A , Dav i s K B, Sopko G, Kaiser GC,Corley SD, Schaf H,Taylor HA,Chaitman BR. Comparison of surgical and medical group survival in patient with left main equivalent coronary artery disease.Long-term CASS experience.Circualtion, 1995; 91(9): 2335-44. 8. Takaro T, Peduzzi P, Detre KM, Hultgreen HN, Murphy ML, van der Bel-Khan J, Thomasen J Meadows WR. Survival in subgroups of patient with left main coronary artery disease.Veterans Administration Cooperative Study of Surgery for Coronary Arterial Occlusive Disease. Circulation, 1982; 66(1): 14-22. 9. Varnauskas E. Twelve-year follow-up of survival in the randomized European Coronary Surgery Study. N Engl J Med, 1988; 319(6): 332-7. 10. Ancona G, Karamanoukian H, Ricci M, Tang L, Salerno T, Bergsland J. Myocardial revascularisation on the beating heart in high risk patients. In Salerno T, Bergslan J (ed): Beating heart coronary artery surgery. Armonk, NY, Futura Publishing Company, 2001: 217-33. 11. Calafiore AM, Giammarco G, Teodori G, Mazzei V, Vitola G. Recent Advances in Multivessel Coronary Grafting Withouth

15.

16.

17.

18.

19.

20.

21.

22.

23.

24.

Cardiopulmonary bypass. Heart Surgery Forum, 1998; 11: 589-600. Bergsland J, Karamanoukian HL, Soltoski P, Salerno T. “Single suture” for circumflex exposure in off-pump coronary artery bypass grafting. Ann Thorac Surg, 1999; 68: 1428-30. Lancey R, Soller B, Vander Salm T. Offpump versus On-pump Coronary Artery Bypass Surgery: A Case-Matched Comparison of clinical Outcomes and Costs. The Heart Surgery Forum, 2000; 3(4): 277-81. Lima R. Revascularizacao da arteria circunflexa sem auxilio da CEC. In: XII Encorto dos Discipulos do Dr.E.J.Zerbini, curitibba. Sessao de Videos. Curitiba, Parana, Sociedada dos Discipulos do Dr.E.J.Zerbini, Outubro, p 6.Louagie YA, Gonzales ME, Shoreder E (1999) Off-pump myocardial revascularisation for the left main stem disease in high-risk patient. Acta Chir Belg, 1995; 99: 309-11. Louagie YA, Gonzales ME, Schröder E. Offpump myocardial revascularisation for left main stem diseaase in high –risk patient. Acta Chir Belg, 1999; (6): 309-11. Cartier R, Brann S, Martineau R, Couturier A. Left main coronary artery stenosis and revascularisation in the beating heart. Short- and long-term experience. Ann Chir, 1999; 53(8): 701-5. Dewey TM, Megee JM, Edgerton JR, Mathison M, Tennison D, Mack JM. Off-Pump Bypass Grafting Is Safe in Patients With Left Main Coronary Disease. Ann Thorac Surg, 2001; 72: 788-92. Yeatman M, Cputo M, Ascione R, Ciulli F, Angelini DG. Off-pump coronary artery bypass for critical left main stem disease: safety, efficacy and outcome. Eur J Cardiothorac Surg, 2001; 19: 239-44. Fukushima S, Kobayashi J, Tagusari O. et all. Rationale of Off-pump Coronary Artery Bypass Grafting for Left Main Trunk Disease. Jpn J Thorac Cardiovasc Surg, 2004; 52(12): 560-6. Buffolo E, Andrade JCS, Succi JE. et all. Direct myocardial revascularisation without extracorporeal circulation: technique and initial results. Texas Heart Inst J, 1985; 12: 33-41. Buffolo E, Andrade JCS, Branco JN, Aguiar LF, Riberio EF, Jantene AD. Myocardial revascularisation without extracorporeal circulation. Seven year experience in 593 cases. Eur J Cardiothorac Surg, 1990; 4: 504-8. Mujanović E. Intraoperativna kontrola kvaliteta koronarnih arterijskih bajpas gratova. Doktorska disertacija. Medicinski fakulteta, Univerzitet u Tuzli, 2005: 55-83. Lu C. Y. John, Grayson AD, Pullan MD. On-Pump versus Off-Pump Surgical Revascularisation for Left-Main Stem Stenosis: Risk Adjusted Outcomes. Ann Thorac Surg, 2005; 80: 136-43. Taggart PD. Coronary Artery Bypass Grafting is Still the Best Treatment for Multivesse and Left Main Disease, But Patients Need to Konw. Ann Thorac Surg, 2006; 82: 1966-75.

Corresponding author: Anel Karic. Address: Clinic of Cardiovascular Diseases, University Clinical Center Tuzla,BiH. Tel. +387 35 303 138. E-mail: [email protected]


331