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Aorta-coronary bypass grafting with polytetrafluoroethylene conduits
J
THoRAc CARDIOVASC SURG
1987;94: 132-4
Aorta-coronary bypass grafting with polytetrafluoroethylene conduits Early and late outcome in eight patients During 1982 and 1983 we performed aorta-coronary bypass grafts on eight patients using 4 mm
polytetrafluoroethylene conduits and predominantly the multiple sequential graft technique. Angiography was performed 1 weekpostoperatively and seven of eight patientshad patent grafts and wereangina free. At 1 year's foUow-up 18 of 28 distal anastomoses werepatent and five of eight patients wereangina free. At 45 month's foUow-up four of 28 distal anastomoses were patent and one of eight patients was angina free.
Richard B. Chard, M.B., B.S., David C. Johnson, F.R.A.C.S., Graham R. Nunn, F.R.A.C.S., and Timothy B. Cartmill, F.R.A.C.S., Sydney, Australia
h e conduits of choice for aorta-coronary bypass grafting are the internal mammary artery and long saphenous veins. If these are unavailable, a short saphenous vein is the next choice. Beyond this, the commonly used alternative is upper limb veins, usually the cephalic. However, these are often thin, of poor caliber, and subject to intravenous cannula insertion, especially in the patient group requiring bypass grafting. Other conduits used include preserved human umbilical vein, radial artery, and splenic and gastroepiploic vessels. The first two have had minimal success.t' and the addition of laparotomy and possibly splenectomy to coronary bypass grafting increases potential morbidity significantly. Synthetic grafts of 4 mm polytetrafluoroethylene* (PTFE) have been used with success by a number of workers.r" During 1982 and 1983 we evaluated this material in eight patients who had no suitable long or short saphenous veins, usually because of varicosities or previous stripping. From the Department of Cardiothoracic Surgery, Westmead Hospital, West mead, Sydney, Australia. Received for publication April 8, 1986. Accepted for publication June 24, 1986. Address for reprints: Dr. D. C. Johnson, 169 Hawkesbury Rd., Westmead, NSW 2145, Sydney Australia. "Gore-Tex vascular grafts, registered trademark of W. L. Gore & Associates, Inc., Elkton, Md.
132
Methods During 1982 and 1983 PTFE was used to fashion aorta-coronary bypass grafts in eight patients. Multiple sequential grafting techniques were used predominantly in an attempt to improve graft flow and limit the length of what is regarded as a less than optimal conduit. Multiple sequential grafts were used alone in six patients. These were done with a single aortic anastomosis with continuous 6-0 Prolene sutures. Side-to-side anastomoses of the diamond-to-diamond type were performed with continuous 7-0 Prolene sutures, the graft being passed around the heart such that it formed a smooth curve. Two of eight patients had a sequential graft. One of the two also had a single PTFE graft from the aorta to the left anterior descending coronary artery (LAD), and the other had a poor-quality saphenous vein graft from the aorta to the diagonal LAD with a side-to-side anastomosis to the LAD. Angiography was performed 1 week postoperatively in all cases. Follow-up over 45 months was performed clinically. Renewed angina was used as an indication for repeat angiography. In addition one patient, angina free, was electively restudied 45 months postoperatively.
Results (Table I) Seven of eight patients are still alive 45 months later. One died of m;yocardial failure in the postbypass
Volume 94 Number 1
Coronary bypass with PTFE conduits
July 1987
13 3
Table I. Results
2
4
5 6
7
8
Early (I wk) postop. angiogram
Grafts done
Patient
Aorta-RCA graft with side-to-side anastomoses to MCx, diagonal branch of LAD, and LAD Aorta-LAD graft, aorta-post. desc. artery graft with side-to-side anastomoses to MCx and first diagonal branch Aorta-LAD graft with side-to-side anastomoses to MCx, diagonal branch of LAD, and posterolateral branch of Cx Aorta-RCA graft with side-to-side anastomoses to MCx and posterolateral branch of Cx Aorta-RCA graft with side-to-side anastomoses to MCx and LAD G raft from aorta to posterolateral branch of Cx, with side-to-side anastomosis to intermediate artery; vein grafts: aorta to LAD and diagonal branch of LAD Aorta-post. desc. artery graft with side-to-side anastomoses to MCx, diagnonal branch of LAD, and LAD Aorta-MCx graft with side-to-side anastomoses to intermediate artery, diagonal branch of LAD, and LAD
Late result
Patent
Return of angina at 4 mo; proximal obstruction on angiogram
Patent
Patent
Angina at 35 mo; on repeat angiography: aorta-LAD graft patent, 95% stenosis at origin of sequential graft Angina-free at 46 mo; on repeat angiography, diagonal LAD skip graft blocked, three of four grafts functioning Return of angina; blockage at 16 mo
Patent
Blockage at 3 mo
PTFE graft patent; vein graft occluded (poor quality vein)
Return of angina at 36 rno, PTFE graft blocked
Patent
Return of angina at 16 mo, occlusion on angiography
Patent
Occlusion of graft and return of angina; graft redone with cephalic vein
Legend: RCA, Main right coronary artery. MCx. Marginal circumflex artery. LAD, Left anterior descending coronary artery. Cx, Circumtlex artery. PTFE, Polytetrafluorocthylcne.
period during a reoperation 16 months after the original operation. Twenty-four of 28 anastomoses were patent at 1 week. In one patient four anastomoses on a sequential graft were occluded 4 days postoperatively. At 1 year 18 ofthe 28 anastomoses were patent and five patients were angina free. At 2 years nine of the 28 anastomoses were patent and three patients were angina free. At 3 years six of the 28 anastomoses were patent and two patients were angina free. At 45 months four of the 28 anastomoses were patent and one patient was angina free. In the angina-free patient three of four anastomoses on a sequential graft were patent. The other patent graft, present in a patient who had angina, was a single aorta-LAD graft. This patient also had a sequential graft that was 95% occluded (Fig. 1).
Discussion The short-term patency rate of 18 of 28 anastomoses
(64%) after 12 months is comparable with the experi-
ence reported by Sapsford, Oakley, and Talbot,' in which 61% were patent at 3 months. The attrition rate after 2 years is also comparable, as three of the eight patients were angina free and nine of the 28 anastomoses were patent. Sapsford, Oakley, and Talbot! reported that six of 27 grafts were patent at 2 years. Several groups have reported single cases with 53 months' and 18 months' patency.v" The mode of failure of PTFE grafts observed at reoperation has been bridging across the side-to-side anastomoses by the pseudointima. The aorta-graft anastomoses were obstructed totally but the lumen of the graft had a smooth pseudointima with some nonadherent thrombus (Fig. 2). The graft in Fig. 1 shows this process. We suspect that the distal anastomoses become obstructed initially by pseudointimal thickening and bridging, and then, with reduced runoff, the aortagraft anastomosis becomes obstructed. In our view, the results are unacceptable. Furthermore, the results of published series of aorta-coronary
The Journal of Thoracic and Cardiovascular
1 3 4 Chard et al.
Fig. 1. Patient 2. A, Angiogram of sequential graft 7 days postoperatively. B. Angiogram of sequential graft 35 months postoperatively showing 95% proximal stenosis.
grafts constructed with arm veins are also poor. Stoney's group? described a 57% 2 year patency rate and Prieto, Basile, and Abdulvour" showed five of eight grafts patent at 1 year with two of those having gross abnormalities. The problem of what to use when the optimal conduits are not available remains unanswered. REFERENCES I. Carpentier A, Guermonprez JL, DeLoche A, Frechette C, Dubost C. The aorta to coronary radial artery bypass graft. Ann Thorac Surg 1973;16:111-21. 2. Edwards WS, Blakeley WR, Lewis CEo Technique of coronary bypass with antogenous arteries. J THORAC CAR· DlOVASC SURG 1973;65:272-5. 3. Sapsford RN, Oakley GO, Talbot S. Early and late patency of expanded polytetraftuoroethylene vascular
Surgery
Fig. 2. Patient 7. Operative specimen showing smooth pseudointima with nonadherent thrombus.
4.
5.
6.
7.
8.
grafts in aorta-coronary bypass. J THoRAc CARDlOVASC SURG 1981;81:860-4. Molina JE, Carr M, Yarnoz MD. Coronary bypass with Gore-Tex graft. J THoRAc CARDIOVASC SURG 1978;75:76971. Islam MN, Zikria EA, Sullivan ME, et al. Aorto coronary Gore-Tex graft: 18 month patency. Ann Thorac Surg 1981;31:569-73. Murtra M, Mestres CA, Igual A. Long term patency of polytetraftuoroethylene vascular grafts in coronary artery surgery. Ann Thorac Surg 1984;37:86-7. Stoney WS, Alford WC, Burrus GR, Glassford DM, Petracek MR, Thomas CS. The fate of arm veins used for aorta-coronary bypass grafts. J THoRAc CARDIOVASC SURG 1984;88:522-6. Prietro I, Basile F, Abdulvour E. Upper extremity vein graft for aorta-coronary bypass. Ann Thorae Surg 1984; 37:218-21.
THoRAc CARDIOVASC SURG
1987;94: 132-4
Aorta-coronary bypass grafting with polytetrafluoroethylene conduits Early and late outcome in eight patients During 1982 and 1983 we performed aorta-coronary bypass grafts on eight patients using 4 mm
polytetrafluoroethylene conduits and predominantly the multiple sequential graft technique. Angiography was performed 1 weekpostoperatively and seven of eight patientshad patent grafts and wereangina free. At 1 year's foUow-up 18 of 28 distal anastomoses werepatent and five of eight patients wereangina free. At 45 month's foUow-up four of 28 distal anastomoses were patent and one of eight patients was angina free.
Richard B. Chard, M.B., B.S., David C. Johnson, F.R.A.C.S., Graham R. Nunn, F.R.A.C.S., and Timothy B. Cartmill, F.R.A.C.S., Sydney, Australia
h e conduits of choice for aorta-coronary bypass grafting are the internal mammary artery and long saphenous veins. If these are unavailable, a short saphenous vein is the next choice. Beyond this, the commonly used alternative is upper limb veins, usually the cephalic. However, these are often thin, of poor caliber, and subject to intravenous cannula insertion, especially in the patient group requiring bypass grafting. Other conduits used include preserved human umbilical vein, radial artery, and splenic and gastroepiploic vessels. The first two have had minimal success.t' and the addition of laparotomy and possibly splenectomy to coronary bypass grafting increases potential morbidity significantly. Synthetic grafts of 4 mm polytetrafluoroethylene* (PTFE) have been used with success by a number of workers.r" During 1982 and 1983 we evaluated this material in eight patients who had no suitable long or short saphenous veins, usually because of varicosities or previous stripping. From the Department of Cardiothoracic Surgery, Westmead Hospital, West mead, Sydney, Australia. Received for publication April 8, 1986. Accepted for publication June 24, 1986. Address for reprints: Dr. D. C. Johnson, 169 Hawkesbury Rd., Westmead, NSW 2145, Sydney Australia. "Gore-Tex vascular grafts, registered trademark of W. L. Gore & Associates, Inc., Elkton, Md.
132
Methods During 1982 and 1983 PTFE was used to fashion aorta-coronary bypass grafts in eight patients. Multiple sequential grafting techniques were used predominantly in an attempt to improve graft flow and limit the length of what is regarded as a less than optimal conduit. Multiple sequential grafts were used alone in six patients. These were done with a single aortic anastomosis with continuous 6-0 Prolene sutures. Side-to-side anastomoses of the diamond-to-diamond type were performed with continuous 7-0 Prolene sutures, the graft being passed around the heart such that it formed a smooth curve. Two of eight patients had a sequential graft. One of the two also had a single PTFE graft from the aorta to the left anterior descending coronary artery (LAD), and the other had a poor-quality saphenous vein graft from the aorta to the diagonal LAD with a side-to-side anastomosis to the LAD. Angiography was performed 1 week postoperatively in all cases. Follow-up over 45 months was performed clinically. Renewed angina was used as an indication for repeat angiography. In addition one patient, angina free, was electively restudied 45 months postoperatively.
Results (Table I) Seven of eight patients are still alive 45 months later. One died of m;yocardial failure in the postbypass
Volume 94 Number 1
Coronary bypass with PTFE conduits
July 1987
13 3
Table I. Results
2
4
5 6
7
8
Early (I wk) postop. angiogram
Grafts done
Patient
Aorta-RCA graft with side-to-side anastomoses to MCx, diagonal branch of LAD, and LAD Aorta-LAD graft, aorta-post. desc. artery graft with side-to-side anastomoses to MCx and first diagonal branch Aorta-LAD graft with side-to-side anastomoses to MCx, diagonal branch of LAD, and posterolateral branch of Cx Aorta-RCA graft with side-to-side anastomoses to MCx and posterolateral branch of Cx Aorta-RCA graft with side-to-side anastomoses to MCx and LAD G raft from aorta to posterolateral branch of Cx, with side-to-side anastomosis to intermediate artery; vein grafts: aorta to LAD and diagonal branch of LAD Aorta-post. desc. artery graft with side-to-side anastomoses to MCx, diagnonal branch of LAD, and LAD Aorta-MCx graft with side-to-side anastomoses to intermediate artery, diagonal branch of LAD, and LAD
Late result
Patent
Return of angina at 4 mo; proximal obstruction on angiogram
Patent
Patent
Angina at 35 mo; on repeat angiography: aorta-LAD graft patent, 95% stenosis at origin of sequential graft Angina-free at 46 mo; on repeat angiography, diagonal LAD skip graft blocked, three of four grafts functioning Return of angina; blockage at 16 mo
Patent
Blockage at 3 mo
PTFE graft patent; vein graft occluded (poor quality vein)
Return of angina at 36 rno, PTFE graft blocked
Patent
Return of angina at 16 mo, occlusion on angiography
Patent
Occlusion of graft and return of angina; graft redone with cephalic vein
Legend: RCA, Main right coronary artery. MCx. Marginal circumflex artery. LAD, Left anterior descending coronary artery. Cx, Circumtlex artery. PTFE, Polytetrafluorocthylcne.
period during a reoperation 16 months after the original operation. Twenty-four of 28 anastomoses were patent at 1 week. In one patient four anastomoses on a sequential graft were occluded 4 days postoperatively. At 1 year 18 ofthe 28 anastomoses were patent and five patients were angina free. At 2 years nine of the 28 anastomoses were patent and three patients were angina free. At 3 years six of the 28 anastomoses were patent and two patients were angina free. At 45 months four of the 28 anastomoses were patent and one patient was angina free. In the angina-free patient three of four anastomoses on a sequential graft were patent. The other patent graft, present in a patient who had angina, was a single aorta-LAD graft. This patient also had a sequential graft that was 95% occluded (Fig. 1).
Discussion The short-term patency rate of 18 of 28 anastomoses
(64%) after 12 months is comparable with the experi-
ence reported by Sapsford, Oakley, and Talbot,' in which 61% were patent at 3 months. The attrition rate after 2 years is also comparable, as three of the eight patients were angina free and nine of the 28 anastomoses were patent. Sapsford, Oakley, and Talbot! reported that six of 27 grafts were patent at 2 years. Several groups have reported single cases with 53 months' and 18 months' patency.v" The mode of failure of PTFE grafts observed at reoperation has been bridging across the side-to-side anastomoses by the pseudointima. The aorta-graft anastomoses were obstructed totally but the lumen of the graft had a smooth pseudointima with some nonadherent thrombus (Fig. 2). The graft in Fig. 1 shows this process. We suspect that the distal anastomoses become obstructed initially by pseudointimal thickening and bridging, and then, with reduced runoff, the aortagraft anastomosis becomes obstructed. In our view, the results are unacceptable. Furthermore, the results of published series of aorta-coronary
The Journal of Thoracic and Cardiovascular
1 3 4 Chard et al.
Fig. 1. Patient 2. A, Angiogram of sequential graft 7 days postoperatively. B. Angiogram of sequential graft 35 months postoperatively showing 95% proximal stenosis.
grafts constructed with arm veins are also poor. Stoney's group? described a 57% 2 year patency rate and Prieto, Basile, and Abdulvour" showed five of eight grafts patent at 1 year with two of those having gross abnormalities. The problem of what to use when the optimal conduits are not available remains unanswered. REFERENCES I. Carpentier A, Guermonprez JL, DeLoche A, Frechette C, Dubost C. The aorta to coronary radial artery bypass graft. Ann Thorac Surg 1973;16:111-21. 2. Edwards WS, Blakeley WR, Lewis CEo Technique of coronary bypass with antogenous arteries. J THORAC CAR· DlOVASC SURG 1973;65:272-5. 3. Sapsford RN, Oakley GO, Talbot S. Early and late patency of expanded polytetraftuoroethylene vascular
Surgery
Fig. 2. Patient 7. Operative specimen showing smooth pseudointima with nonadherent thrombus.
4.
5.
6.
7.
8.
grafts in aorta-coronary bypass. J THoRAc CARDlOVASC SURG 1981;81:860-4. Molina JE, Carr M, Yarnoz MD. Coronary bypass with Gore-Tex graft. J THoRAc CARDIOVASC SURG 1978;75:76971. Islam MN, Zikria EA, Sullivan ME, et al. Aorto coronary Gore-Tex graft: 18 month patency. Ann Thorac Surg 1981;31:569-73. Murtra M, Mestres CA, Igual A. Long term patency of polytetraftuoroethylene vascular grafts in coronary artery surgery. Ann Thorac Surg 1984;37:86-7. Stoney WS, Alford WC, Burrus GR, Glassford DM, Petracek MR, Thomas CS. The fate of arm veins used for aorta-coronary bypass grafts. J THoRAc CARDIOVASC SURG 1984;88:522-6. Prietro I, Basile F, Abdulvour E. Upper extremity vein graft for aorta-coronary bypass. Ann Thorae Surg 1984; 37:218-21.