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Is re-revascularization clinically beneficial?
Is Re-revascularization Clinically Beneficial?
Quentin Ft. Stiles, MD, Los Angeles, California James M. Cunningham, MD, Los Angeles, California
After initial myocardial revascularization some patients have recurrence of angina1 symptoms. These symptoms may appear in the first few months after the primary procedure, or they may return later, during the early postoperative years. When contemplating the need for repeated myocardial revascularization in a patient, several questions can be raised: (1) Why did the initial procedure fail to give long-term good results? (2) What are the operative risks of a repeated procedure? (3) What are the chances that the second operation will be successful when the first one failed? (4) What are the indications for reoperation? (5) What special technical considerations are necessary in reoperation? (6) What percentage of patients are returning for reoperation? (7) What can be done to minimize the number of patients returning for a second procedure? The answers to some of these questions are relatively straightforward, whereas the answers to others are not. In previous reports [1,2] we reviewed our experience in the first 50 patients on whom we reoperated for myocardial revascularization. The operations proved hazardous, with a 12 percent mortality, partly because of the risk of accidents on reopening the sternum when the heart and functioning grafts were adherent to the sternum. Twenty-three patients (46 percent) required reoperation in that early series because of occluded grafts from the first operation, 13 (26 percent) because of an inadequate first operation, 3 (6 percent) because of progression of atherosclerosis in ungrafted From the Department of Surgery, University of Southern California School of Medicine, Los Angeles, California. Raqu&s for reprints should be addressed to Quentin Ft. Stiles, MD, 1136 West 6th Street, Los Angeles, California 90017. Presented at the Sixth Annual Lyman A. Brewer Ill Cardiothoracic Symposium, Los Angeles, California, December 3 and 4, 1980.
656
vessels, and ll(22 percent) because of various combinations of these factors. The average interval between the first and second revascularization procedures was 24 months. The patients who survived the second operation had very satisfactory relief of anginal symptoms similar to those with primary operations. In the nine patients who underwent cardiac catheterization after reoperation, 10 of 14 newly fashioned grafts were found to be functional, a patency rate of 71 percent. Despite the increased operative risk from accidents incurred on opening the sternum (seven surgical mishaps), we concluded that the indications for a second attempt were much the same as for primary revascularization. Each surgeon developed considerable respect for reopening the sternum in order to avoid problems associated with technique. Since 1976 we have performed coronary bypass grafts in 51 other patients who had a previous revascularization procedure. Our data were analyzed to determine whether increased experience has produced better clinical results. Lessons we learned from these second generation reoperations are enumerated herein. As of December 1,1980, we have performed coronary arterial grafting in 3,550 patients. Of the total of 101 reoperation patients, 12 had the primary operation done by surgical teams other than our own. Approximately 3 percent of our original patients have returned for a second operation. Two patients have had the procedure done three times. Our percentage of reoperation is essentially the same as that at the Cleveland Clinic [3]. Why did the initial procedure fail to give good long-term results? The factors responsible for the return of angina1 symptoms after an initial revascularization include (1) occlusion of grafts; (2) an in-
The American Journal of Surgery
Is Re-revascularization Clinically Beneficial?
adequate number of grafts constructed, resulting in incomplete revascularization; and (3) progression of atherosclerotic disease in ungrafted vessels. In general we conclude that grafts occlude in the early postoperative period (30 days) from technical errors such as twisting or kinking, too much tension, narrowing or purse-stringing of the anastomotic suture line, or from grafts being sutured to vessels with little runoff. Grafts which become occluded during the interval from 1 month to 1 year are most commonly caused by reactive intimal hyperplasia in the vein segments. After 3 or 4 years the vein grafts may become obstructed by the atherosclerotic process. In our series we have been unable to relate the postpericardiotomy syndrome to graft closure, but this possibility should not be overlooked. Culliford et al [4] felt that excessive pericardial reaction was the cause of graft occlusion in one third of the patients who had early graft failure. Although we are not prepared to defend the concept with significant data, patients who exhibit the typical findings of pericardial friction rub, fever or malaise with pleuritic or pericardial pain should be aggressively treated with steroids. Since the probability of graft occlusion or patency seems to be independent for each graft, the concept of graft construction on a redundant plan has evolved. Several years ago a patient with three-vessel disease usually received three grafts, and that was considered complete revascularization. Now we tend to graft vessels further distally and, by using the sequential type of graft with multiple coronary vessel connections, secondary branches as well as the primary coronary vessels are grafted. Patients with three-vessel disease are now receiving an average of four grafts at an initial operation. Thus, if the patency rate remains the same, the patient will have more functioning grafts and may be less likely to have recurrent angina. Actually the patency rate has improved somewhat over the years, although it is difficult to say whether this is due to the use of sequential grafts or to increased experience of the surgeon. Technical errors involving the proximal portion of a sequeritial graft can result in failure of multiple distal anastomoses, so even greater care should be used to establish the proper length, course and orientation of the graft. Furthermore, too large an opening in the vein should be avoided when the anastomosis is constructed along the transverse axis of the vein. Even with the increased risk of technical error in the sequential grafts, their greater probability of remaining open, presumably from the higher flow rate, more than offsets the risk, resulting in more patent grafts. How often did occluded grafts contribute to the necessity for a second operation? Compared
with 66 percent of the patients in the first series of 50 reoperations, 42 (84 percent) of 51 patients in the
Volume 141, June 1961
later group had occluded grafts. Thus graft occlusion remains by far the single most important factor. Incomplete revascularization at the initial procedure was the second most important factor, involving 48 percent of the first group. In the second group of 51 patients undergoing reoperation, 18 (36 percent) were judged to have had an inadequate first operation when significantly obstructed primary coronary vessel_s were not grafted. The reasons for incomplete revascularization’are often not clear, but lack of determination, aggressiveness or experience on the part of the surgeon appear more common than anatomic reasons. From the foregoing discussion regarding sequential grafting, one might expect that the incidence of incomplete revascularization would be smaller in the second group. The explanation seems obvious when one examines the difference in the interval between operations. In the first 50 patients, an average of 24 months elapsed between operations. In the later series the interval had increased to 56 months with a range of 1 to 133 months. Thus the pool of patients from which selection for reoperation was made was to a large extent the same pool of patients who were operated on earlier when the interval was only 24 months. In the second group only three patients had as a single factor an inadequate first operation. Fifteen patients had-combinations of factors such as occluded grafts and progression of disease in addition to an inadequate first operation. When additional factors developed, incomplete revascularization predisposed these patients to the development of recurrent angina, and the second operation became necessary. Initial complete revascularization might have obviated a second operation. Only 4 patients in the entire series of 101 patients had as many as four grafts at the initial operation, and these patients had multiple graft failure. Our current philosophy is to graft every artery greater than 1 mm in diameter that is obstructed as much as 30 or 40 percent. Progression of disease might be expected to be a more important factor in the second series with the longer interval between operations. This was the case with 24 percent of patients so categorized, compared with 8 percent in the early series. It was not found to occur as a single factor, however, but was always accompanied by occlusion of grafts, an inadequate first operation, or both. What are the risks of reoperation? In the first series we had a high mortality rate (12 percent) and several serious accidents on opening the sternum, but patients in the second series fared much better. There were two hospital deaths, one of which was due to acute pancreatitis in the late postoperative period, perhaps unrelated to the cardic surgery. In the later series five accidents occurred on opening the sternum, involving lacerations of the innominate vein, the pulmonary artery and the right ventricle. These
657
Stilesand Cunningham
were all relatively minor and easily controlled, and did not contribute to patient mortality or morbidity. What is the prognosis after reoperation? When a specific operation has failed to attain its intended purpose, it may seem presumptuous to think that the same or another surgeon can perform a similar procedure with success. With proper patient selection, however, this can be done. Several published series of reoperation for coronary grafting [6-81 report complete relief of angina in 47 to 84 percent of patients, with an average of 62 percent. This is very much in line with our own experience and represents about a 10 percent lower chance of complete relief of angina than is expected in patients undergoing priqary revascularization. The patency rate of newly constructed grafts is difficult to establish because of the small numbers of patients routinely undergoing cardiac catheterization after the second procedure. Published reports indicate that the expected patency rate should be only slightly lower than that after primary coronary arterial grafting [3,7,9]. What are the indications for reoperation? We continue to think that indications for repeated surgery should be much the same as those for a primary procedure. The decision is based on (1) the presence of angina or the objective demonstration of myocardial ischemia by either stress electrocardiography or radionuclide study, or both, and (2) anatomic demonstration of the feasibility of grafting two or more target vessels at least 1.5 mm in diameter with a significant myocardial distribution. Carrying out a second operation when only a single target is demonstrated for grafting should make the surgeon consider the risk-benefit ratio very carefully. Additional factors to be considered in the evaluation are the functional state of the left ventricle and a review of the previous operative notes to learn whether the pericardium was closed and how the surgeon described the distal vessels. If the pericardium was left open, one should assume a higher risk of accident on opening the sternum. What special technical considerations are required in reoperation? As with all repeated
TABLE I
658
Percentage of Patients Returning for Surgery
Year
PoolOf Patients
1975 1976 1977 1978 1979 1980
1,017 1,405 1,793 2,084 2,375 ,2.666
Reoperated n
%
5 7 10 9 11 9
0.49 0.50
0.56 0.43 0.46 0.34
sternotomy procedures, certain precautions should be taken to minimize the possibility of a surgical accident. 30th groins are exposed in the sterile field, but the femoral vessels are not routinely exposed before division of the sternum. Blunt dissection behind the sternum and xiphoid is avoided. The Stryker oscillating saw is preferred to divide the outer table of the sternum. The inner table is then divided very carefully either with this saw, heavy scissors or a Lebsche knife, or by a combination of these techniques. The sternal retractor is not placed until the posterior aspect of the sternal halves is freed for several centimeters on both sides. Concentration is then focused on exposing sufficient right atrium and ascending aorta to allow rapid c~nulation and establishment of c~diopulmon~ bypass if necessary. The surgeon has the option of proceeding with dissection to free the heart of adhesions before bypass or to establish bypass and finish the dissection of adhesions when the heart is decompressed. Dissection is usually made much easier by the latter course. If the left internal mammary artery was not used in the first operation, we think it is an excellent conduit to be used in the repeated procedure. Postoperative bleeding has not been as much of a problem in our experience as might be expected. During the procedure, we have found that the Cell Saver device (Haemonetics, Natik, Massachusetts) enables us to keep transfusions in these patients to a minimum. This device collects and heparinizes shed blood, which is then washed, centrifuged and returned to the patient as packed red blood cells. What percentage of patients return for reoperation, and how can we minimize this number? The proportion of patients undergoing a second revascularization as compared with a primary procedure has remained about 2 percent over the past 6 years. These reoperated patients are drawn from an ever-increasing pool of patients who have had an initial procedure. It is evident from the increasing interval between operations in the more recent series that these patients are still being selected mainly fromi those operated on for the first time during our earlier experience, when we were constructing far fewer coronary anastomoses per operation than is our current practice. We can see from these data that the percentage of patients returning for surgery has not changed much over the past 6 years (Table I). It should stay at a very low rate for some time, but perhaps we may begin to see a significantly higher graft occlusion rate from the atherosclerotic process in the future. To minimize the chances of requiring a second procedure, the first attempt should be carried out in a technically flawless manner, and all primary coronary vessels and any secondary branches should be
The American Journal of Surgery
Is Re-revascularization
grafted if there is as much as 30 or 40 percent proximal luminal narrowing. After the initial procedure, prudence appears to dictate, even in the absence of scientific proof, that the patient should do his part by altering the risk factors associated with the development of atherosclerotic disease. We conclude from our data that re-revascularization is clinically beneficial and well worth the extra effort required. Careful patient selection and precise operative technique are essential if a favorable outcome is to be expected. Summary The decision to perform a second operation for myocardial revascularization is a difficult one. Review of our experience with 101 such patients reveals that the second procedure can be conducted with reasonable safety, and results can be achieved which are nearly as satisfactory as with primary procedures. The indications for repeat operation are much the same as for the initial surgery. In many cases, complete revascularization at the first operation will prevent the need for a second one.
Volume 141, June 1981
Clinically
Beneficial?
References 1. Stiles GR. Reoperation for myocardial revascularization. Cleve Clin Q 1978;45:136-8. 2. Stiles QR, Lindesmith GG, Tucker BL, Hughes RK, Meyer BW. Experience with fifty repeat procedures for myocardial revascularization. J Thorac Cardiovasc Surg 1976;72:84953. 3. Loop FD, Thurer RL, Lytle BW, Cosgrove DM. Reoperation for myocardial revascularization. World J Surg 1978;2:71929. 4. Culliford AT, Girdwood RW, lsom OW, Krauss KR, Spencer FC. Angina following myocardial revascularization. Does time of recurrence predict etiology and influence results of operation? J Thorac Cardiovasc Surg 1979;77:889-95. 5. Norwood WI, Cohn LH, Collins JJ. Results of operation for recurrent angina pectoris. Ann Thorac Surg 1977;23:9-13. 6. Kobayashi T, Mendez AM Zubiate P, Vanstrom NR, Yokoyama T, Kay JH. Repeat aortocoronary bypass grafting. Early and late results. Chest 1978;73:446-9. 7. lrarrazaval MJ, Cosgrove DM, Loop FD, Ennix CL, Groves LK, Taylor PC. Reoperations for myocardial revascularization. J Thorac Cardiovasc Surg 1977;73:181-8. 8. Oglietti J, Angelini P, Leachman RD. Cooley DA. Myocardial revascularization. Early and late results after operation.’ J Thorac Cardiovasc Surg 1976;71:736-40. 9. Vouhe P, Grondin CM. Reoperation for coronary graft failure: Clinical and angiographic results in 43 patients. Ann Thorac Surg 1979;27:328-34.
659
Quentin Ft. Stiles, MD, Los Angeles, California James M. Cunningham, MD, Los Angeles, California
After initial myocardial revascularization some patients have recurrence of angina1 symptoms. These symptoms may appear in the first few months after the primary procedure, or they may return later, during the early postoperative years. When contemplating the need for repeated myocardial revascularization in a patient, several questions can be raised: (1) Why did the initial procedure fail to give long-term good results? (2) What are the operative risks of a repeated procedure? (3) What are the chances that the second operation will be successful when the first one failed? (4) What are the indications for reoperation? (5) What special technical considerations are necessary in reoperation? (6) What percentage of patients are returning for reoperation? (7) What can be done to minimize the number of patients returning for a second procedure? The answers to some of these questions are relatively straightforward, whereas the answers to others are not. In previous reports [1,2] we reviewed our experience in the first 50 patients on whom we reoperated for myocardial revascularization. The operations proved hazardous, with a 12 percent mortality, partly because of the risk of accidents on reopening the sternum when the heart and functioning grafts were adherent to the sternum. Twenty-three patients (46 percent) required reoperation in that early series because of occluded grafts from the first operation, 13 (26 percent) because of an inadequate first operation, 3 (6 percent) because of progression of atherosclerosis in ungrafted From the Department of Surgery, University of Southern California School of Medicine, Los Angeles, California. Raqu&s for reprints should be addressed to Quentin Ft. Stiles, MD, 1136 West 6th Street, Los Angeles, California 90017. Presented at the Sixth Annual Lyman A. Brewer Ill Cardiothoracic Symposium, Los Angeles, California, December 3 and 4, 1980.
656
vessels, and ll(22 percent) because of various combinations of these factors. The average interval between the first and second revascularization procedures was 24 months. The patients who survived the second operation had very satisfactory relief of anginal symptoms similar to those with primary operations. In the nine patients who underwent cardiac catheterization after reoperation, 10 of 14 newly fashioned grafts were found to be functional, a patency rate of 71 percent. Despite the increased operative risk from accidents incurred on opening the sternum (seven surgical mishaps), we concluded that the indications for a second attempt were much the same as for primary revascularization. Each surgeon developed considerable respect for reopening the sternum in order to avoid problems associated with technique. Since 1976 we have performed coronary bypass grafts in 51 other patients who had a previous revascularization procedure. Our data were analyzed to determine whether increased experience has produced better clinical results. Lessons we learned from these second generation reoperations are enumerated herein. As of December 1,1980, we have performed coronary arterial grafting in 3,550 patients. Of the total of 101 reoperation patients, 12 had the primary operation done by surgical teams other than our own. Approximately 3 percent of our original patients have returned for a second operation. Two patients have had the procedure done three times. Our percentage of reoperation is essentially the same as that at the Cleveland Clinic [3]. Why did the initial procedure fail to give good long-term results? The factors responsible for the return of angina1 symptoms after an initial revascularization include (1) occlusion of grafts; (2) an in-
The American Journal of Surgery
Is Re-revascularization Clinically Beneficial?
adequate number of grafts constructed, resulting in incomplete revascularization; and (3) progression of atherosclerotic disease in ungrafted vessels. In general we conclude that grafts occlude in the early postoperative period (30 days) from technical errors such as twisting or kinking, too much tension, narrowing or purse-stringing of the anastomotic suture line, or from grafts being sutured to vessels with little runoff. Grafts which become occluded during the interval from 1 month to 1 year are most commonly caused by reactive intimal hyperplasia in the vein segments. After 3 or 4 years the vein grafts may become obstructed by the atherosclerotic process. In our series we have been unable to relate the postpericardiotomy syndrome to graft closure, but this possibility should not be overlooked. Culliford et al [4] felt that excessive pericardial reaction was the cause of graft occlusion in one third of the patients who had early graft failure. Although we are not prepared to defend the concept with significant data, patients who exhibit the typical findings of pericardial friction rub, fever or malaise with pleuritic or pericardial pain should be aggressively treated with steroids. Since the probability of graft occlusion or patency seems to be independent for each graft, the concept of graft construction on a redundant plan has evolved. Several years ago a patient with three-vessel disease usually received three grafts, and that was considered complete revascularization. Now we tend to graft vessels further distally and, by using the sequential type of graft with multiple coronary vessel connections, secondary branches as well as the primary coronary vessels are grafted. Patients with three-vessel disease are now receiving an average of four grafts at an initial operation. Thus, if the patency rate remains the same, the patient will have more functioning grafts and may be less likely to have recurrent angina. Actually the patency rate has improved somewhat over the years, although it is difficult to say whether this is due to the use of sequential grafts or to increased experience of the surgeon. Technical errors involving the proximal portion of a sequeritial graft can result in failure of multiple distal anastomoses, so even greater care should be used to establish the proper length, course and orientation of the graft. Furthermore, too large an opening in the vein should be avoided when the anastomosis is constructed along the transverse axis of the vein. Even with the increased risk of technical error in the sequential grafts, their greater probability of remaining open, presumably from the higher flow rate, more than offsets the risk, resulting in more patent grafts. How often did occluded grafts contribute to the necessity for a second operation? Compared
with 66 percent of the patients in the first series of 50 reoperations, 42 (84 percent) of 51 patients in the
Volume 141, June 1961
later group had occluded grafts. Thus graft occlusion remains by far the single most important factor. Incomplete revascularization at the initial procedure was the second most important factor, involving 48 percent of the first group. In the second group of 51 patients undergoing reoperation, 18 (36 percent) were judged to have had an inadequate first operation when significantly obstructed primary coronary vessel_s were not grafted. The reasons for incomplete revascularization’are often not clear, but lack of determination, aggressiveness or experience on the part of the surgeon appear more common than anatomic reasons. From the foregoing discussion regarding sequential grafting, one might expect that the incidence of incomplete revascularization would be smaller in the second group. The explanation seems obvious when one examines the difference in the interval between operations. In the first 50 patients, an average of 24 months elapsed between operations. In the later series the interval had increased to 56 months with a range of 1 to 133 months. Thus the pool of patients from which selection for reoperation was made was to a large extent the same pool of patients who were operated on earlier when the interval was only 24 months. In the second group only three patients had as a single factor an inadequate first operation. Fifteen patients had-combinations of factors such as occluded grafts and progression of disease in addition to an inadequate first operation. When additional factors developed, incomplete revascularization predisposed these patients to the development of recurrent angina, and the second operation became necessary. Initial complete revascularization might have obviated a second operation. Only 4 patients in the entire series of 101 patients had as many as four grafts at the initial operation, and these patients had multiple graft failure. Our current philosophy is to graft every artery greater than 1 mm in diameter that is obstructed as much as 30 or 40 percent. Progression of disease might be expected to be a more important factor in the second series with the longer interval between operations. This was the case with 24 percent of patients so categorized, compared with 8 percent in the early series. It was not found to occur as a single factor, however, but was always accompanied by occlusion of grafts, an inadequate first operation, or both. What are the risks of reoperation? In the first series we had a high mortality rate (12 percent) and several serious accidents on opening the sternum, but patients in the second series fared much better. There were two hospital deaths, one of which was due to acute pancreatitis in the late postoperative period, perhaps unrelated to the cardic surgery. In the later series five accidents occurred on opening the sternum, involving lacerations of the innominate vein, the pulmonary artery and the right ventricle. These
657
Stilesand Cunningham
were all relatively minor and easily controlled, and did not contribute to patient mortality or morbidity. What is the prognosis after reoperation? When a specific operation has failed to attain its intended purpose, it may seem presumptuous to think that the same or another surgeon can perform a similar procedure with success. With proper patient selection, however, this can be done. Several published series of reoperation for coronary grafting [6-81 report complete relief of angina in 47 to 84 percent of patients, with an average of 62 percent. This is very much in line with our own experience and represents about a 10 percent lower chance of complete relief of angina than is expected in patients undergoing priqary revascularization. The patency rate of newly constructed grafts is difficult to establish because of the small numbers of patients routinely undergoing cardiac catheterization after the second procedure. Published reports indicate that the expected patency rate should be only slightly lower than that after primary coronary arterial grafting [3,7,9]. What are the indications for reoperation? We continue to think that indications for repeated surgery should be much the same as those for a primary procedure. The decision is based on (1) the presence of angina or the objective demonstration of myocardial ischemia by either stress electrocardiography or radionuclide study, or both, and (2) anatomic demonstration of the feasibility of grafting two or more target vessels at least 1.5 mm in diameter with a significant myocardial distribution. Carrying out a second operation when only a single target is demonstrated for grafting should make the surgeon consider the risk-benefit ratio very carefully. Additional factors to be considered in the evaluation are the functional state of the left ventricle and a review of the previous operative notes to learn whether the pericardium was closed and how the surgeon described the distal vessels. If the pericardium was left open, one should assume a higher risk of accident on opening the sternum. What special technical considerations are required in reoperation? As with all repeated
TABLE I
658
Percentage of Patients Returning for Surgery
Year
PoolOf Patients
1975 1976 1977 1978 1979 1980
1,017 1,405 1,793 2,084 2,375 ,2.666
Reoperated n
%
5 7 10 9 11 9
0.49 0.50
0.56 0.43 0.46 0.34
sternotomy procedures, certain precautions should be taken to minimize the possibility of a surgical accident. 30th groins are exposed in the sterile field, but the femoral vessels are not routinely exposed before division of the sternum. Blunt dissection behind the sternum and xiphoid is avoided. The Stryker oscillating saw is preferred to divide the outer table of the sternum. The inner table is then divided very carefully either with this saw, heavy scissors or a Lebsche knife, or by a combination of these techniques. The sternal retractor is not placed until the posterior aspect of the sternal halves is freed for several centimeters on both sides. Concentration is then focused on exposing sufficient right atrium and ascending aorta to allow rapid c~nulation and establishment of c~diopulmon~ bypass if necessary. The surgeon has the option of proceeding with dissection to free the heart of adhesions before bypass or to establish bypass and finish the dissection of adhesions when the heart is decompressed. Dissection is usually made much easier by the latter course. If the left internal mammary artery was not used in the first operation, we think it is an excellent conduit to be used in the repeated procedure. Postoperative bleeding has not been as much of a problem in our experience as might be expected. During the procedure, we have found that the Cell Saver device (Haemonetics, Natik, Massachusetts) enables us to keep transfusions in these patients to a minimum. This device collects and heparinizes shed blood, which is then washed, centrifuged and returned to the patient as packed red blood cells. What percentage of patients return for reoperation, and how can we minimize this number? The proportion of patients undergoing a second revascularization as compared with a primary procedure has remained about 2 percent over the past 6 years. These reoperated patients are drawn from an ever-increasing pool of patients who have had an initial procedure. It is evident from the increasing interval between operations in the more recent series that these patients are still being selected mainly fromi those operated on for the first time during our earlier experience, when we were constructing far fewer coronary anastomoses per operation than is our current practice. We can see from these data that the percentage of patients returning for surgery has not changed much over the past 6 years (Table I). It should stay at a very low rate for some time, but perhaps we may begin to see a significantly higher graft occlusion rate from the atherosclerotic process in the future. To minimize the chances of requiring a second procedure, the first attempt should be carried out in a technically flawless manner, and all primary coronary vessels and any secondary branches should be
The American Journal of Surgery
Is Re-revascularization
grafted if there is as much as 30 or 40 percent proximal luminal narrowing. After the initial procedure, prudence appears to dictate, even in the absence of scientific proof, that the patient should do his part by altering the risk factors associated with the development of atherosclerotic disease. We conclude from our data that re-revascularization is clinically beneficial and well worth the extra effort required. Careful patient selection and precise operative technique are essential if a favorable outcome is to be expected. Summary The decision to perform a second operation for myocardial revascularization is a difficult one. Review of our experience with 101 such patients reveals that the second procedure can be conducted with reasonable safety, and results can be achieved which are nearly as satisfactory as with primary procedures. The indications for repeat operation are much the same as for the initial surgery. In many cases, complete revascularization at the first operation will prevent the need for a second one.
Volume 141, June 1981
Clinically
Beneficial?
References 1. Stiles GR. Reoperation for myocardial revascularization. Cleve Clin Q 1978;45:136-8. 2. Stiles QR, Lindesmith GG, Tucker BL, Hughes RK, Meyer BW. Experience with fifty repeat procedures for myocardial revascularization. J Thorac Cardiovasc Surg 1976;72:84953. 3. Loop FD, Thurer RL, Lytle BW, Cosgrove DM. Reoperation for myocardial revascularization. World J Surg 1978;2:71929. 4. Culliford AT, Girdwood RW, lsom OW, Krauss KR, Spencer FC. Angina following myocardial revascularization. Does time of recurrence predict etiology and influence results of operation? J Thorac Cardiovasc Surg 1979;77:889-95. 5. Norwood WI, Cohn LH, Collins JJ. Results of operation for recurrent angina pectoris. Ann Thorac Surg 1977;23:9-13. 6. Kobayashi T, Mendez AM Zubiate P, Vanstrom NR, Yokoyama T, Kay JH. Repeat aortocoronary bypass grafting. Early and late results. Chest 1978;73:446-9. 7. lrarrazaval MJ, Cosgrove DM, Loop FD, Ennix CL, Groves LK, Taylor PC. Reoperations for myocardial revascularization. J Thorac Cardiovasc Surg 1977;73:181-8. 8. Oglietti J, Angelini P, Leachman RD. Cooley DA. Myocardial revascularization. Early and late results after operation.’ J Thorac Cardiovasc Surg 1976;71:736-40. 9. Vouhe P, Grondin CM. Reoperation for coronary graft failure: Clinical and angiographic results in 43 patients. Ann Thorac Surg 1979;27:328-34.
659