Bilateral Internal Thoracic Artery Composite Y Grafts: Analysis of 464 Angiograms in 296 Patients.
BACKGROUND
The use of bilateral internal thoracic arteries (BITA) in coronary artery bypass graft surgery improves patient survival. The optimum BITA graft configuration is unknown. This study evaluates outcomes after the use of bilateral internal mammary Y grafting as the primary grafting strategy.


METHODS
Patients who underwent BITA composite Y grafting (n = 1,011) between October 1994 and March 2009 were identified from a cardiac surgical database. Follow-up (mean 12 years) was obtained by cross-reference with the state death registry and local cardiology databases.


RESULTS
Perioperative mortality was 1.6%. Kaplan-Meier 10-year survival was 87.2%. There were 464 episodes of postdischarge angiography in 296 patients, at an average of 5.5 years to first angiography. Graft failure occurred in 151 patients, predominately affecting the right ITA limb (n = 139). Degree of native vessel stenosis (odds ratio [OR] 0.66 per 10% increase), anatomic territory grafted (circumflex OR 2.64, right coronary OR 6.73 versus anterior), and end-to-side free wall anastomoses (OR 1.98) predicted anastomotic occlusion. The left anterior descending artery graft patency was unaffected by sequential grafting. Progression to graft failure after the first angiogram was rarely seen in the 111 patients who had serial angiography.


CONCLUSIONS
Outcomes of BITA Y grafting are similar to those for other BITA configurations. The rate of presentation with arterial graft dysfunction decreases over time. Although competitive flow affects anastomotic patency, there is no threshold at which risk of occlusion substantially increases.
Baird Institute of Applied Heart and Lung Surgical Research, Sydney, Australia.
Benjamin M
BM
Robinson
Kolling Institute of Medical Research, Royal North Shore Hospital, Sydney, Australia; Faculty of Medicine, University of Sydney, Sydney, Australia. Electronic address: patersonh@aol.com.
Hugh S
HS
Paterson
Department of Cardiothoracic Surgery, The Prince Charles Hospital, Brisbane, Australia.
Rishendran
R
Naidoo
Baird Institute of Applied Heart and Lung Surgical Research, Sydney, Australia.
Vikrant
V
Dhurandhar
Department of Cardiology, Westmead Hospital, Sydney, Australia; Faculty of Medicine, University of Sydney, Sydney, Australia.
A Robert
AR
Denniss
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001315:Australia / Q000453:epidemiology; D017023:Coronary Angiography; D023921:Coronary Stenosis / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006085:Graft Survival; D006801:Humans; D015994:Incidence; D007387:Internal Mammary-Coronary Artery Anastomosis / Q000379:methods* / Q000401:mortality; D008297:Male; D008323:Mammary Arteries / Q000000981:diagnostic imaging / Q000502:physiology / Q000637:transplantation*; D008875:Middle Aged; D011183:Postoperative Complications / Q000453:epidemiology*; D012042:Registries; D012189:Retrospective Studies; D015996:Survival Rate / Q000639:trends; D013997:Time Factors; D014654:Vascular Patency