Free Right Internal Thoracic Artery Research Articles

The Growth Potential and Patency of Free Right Internal Thoracic Arteries Verified by Computed Tomography Angiography

BackgroundThe use of the left internal thoracic artery (LITA) is the gold standard in coronary artery bypass graft surgery (CABG). Multiarterial grafting for CABG is being increasingly emphasized. This study aimed to resolve the utility of the right internal thoracic artery (RITA) for multiple CABG as “free” RITA and described new evidence. MethodsOne hundred sixty-three patients received solo CABG with bilateral internal thoracic arteries between 2005 and 2018. The RITA was used as in situ RITA, group A (n = 62), and the composite graft created with saphenous vein graft (SVG), group B (n = 101). The patency rate and graft size of the composite free RITA and SVG were examined by coronary computed tomography angiography. ResultsThe average number of distal anastomoses per patient was 3.4 ± 1.0 in group A, and 4.2 ± 1.1 in group B (P < .001). The sequential grafting with free RITA was in 86 patients. The patency rate of both LITA and RITA was similar in both groups. In group B, 40 patients received late computed tomography angiography at a mean of 46 months (range, 17 to 175). The late patency rate was 95.1% in LITA and 96.9% in free RITA. The diameter of free RITA increased from 2.06 ± 0.34 mm to 2.37 ± 0.23 mm (P = .036); that of in situ LITA increased from 2.08 ± 0.51 mm to 2.44 ± 0.49 mm (P = .047); and that of composite SVG decreased from 4.1 ± 0.9 mm to 2.6 ± 0.7 mm (P < .001). ConclusionsMultiple bypass grafting can be sufficiently achieved with LITA and free RITA. The growth potential of free RITA and in situ LITA might play the important role of expected long-term patency.

Second best conduit-is it the tag or patency that counts?

The Radial Artery Patency and Clinical Outcomes (RAPCO) trial compared radial artery (RA) with free right internal thoracic artery (RITA) and saphenous vein grafts (SVG). This was a prospective, randomized, single-center trial with two separate arms (RA-RITA and RA-SVG). The study showed that RA was superior to free RITA in terms of 10-year angiographic patency and provided a survival advantage as well. In contrast, RA-SVG comparison suggested a trend towards better outcomes with RA but no statistically significant difference in patency or survival. In this appraisal of the RAPCO trial, both the conduct and the findings have been critically evaluated. The concerns over using free RITA as aorto-coronary grafts as opposed to composite grafts and the insufficient sample size for the RA-SVG comparison have been highlighted. In the RAPCO trial that spanned almost quarter of a century, patency of all three conduits studied in the trial appears satisfactory.

Long-term graft patency after coronary artery bypass grafting: Effects of surgical technique.

The aim of the current study was to identify surgical factors associated with long-term patency of grafts used in coronary artery bypass grafting (CABG). The present study analyzed data from 127 patients who underwent CABG at our institute between 2000 and 2006 and presented for ambulatory examination and coronary computed tomography angiography evaluation of graft patency in 2016 (139.78±36.64 months post-CABG). The 127 patients received 340 grafts (2.68 grafts/patient) and 399 distal anastomoses (3.14 anastomoses/patient), 220 (55.14%) with arterial grafts and 179 (44.86%) with saphenous vein grafts. Graft patency varied according to coronary territory, proximal anastomosis type (in situ graft, composite graft, graft anastomosed to the ascending aorta), Y anastomosis angle (47.21° for patent arterial grafts vs. 56° for occluded), and distal anastomosis angle (in sequential anastomoses irrespective to graft type, 48.60° for patent side-to-side anastomosis vs. 53.97° for occluded, 65.12° for patent end-to-side anastomosis vs. 90.80° for occluded; in single end-to-side anastomosis of arterial grafts, 39.46° for patent and 44.94° for occluded). A single end-to-side anastomosis angle 60° or greater was associated with a 5.149 occlusion odds ratio (OR) (P<0.001) for arterial grafts. Venous grafts were not sensitive to single end-to-side anastomosis angle. In conclusion, a small anastomosis angle for proximal Y and distal anastomoses is associated with a higher long-term patency of the free graft. Radial artery grafts registered higher patency rates when anastomosed to the ascending aorta compared with composite grafting with the left internal thoracic artery, whereas in situ right internal thoracic artery (RITA) anastomosed to the right coronary territory is associated with a lower patency rate compared with free RITA used to revascularise the anterolateral or circumflex territory in composite grafting.

Abstract 11559: Long-term Outcomes of in situ versus Free Right Internal Thoracic Artery Grafting for Multivessel Coronary Artery Bypass Graft Surgery

Introduction: The right internal thoracic artery (RITA) is occasionally used as a free graft when it does not have sufficient length to reach the target vessels. We compared the long-term clinical outcomes in propensity score-matched patients undergoing coronary artery bypass grafting (CABG), using the RITA as an in situ or free graft. Methods: From September 2004 to June 2013, 1413 patients underwent isolated CABG using the bilateral internal thoracic artery (ITA) for the revascularization of the left coronary system. Of these, 1365 patients undergoing CABG using the RITA as an in situ graft (n=878) or a free graft (n=487) were retrospectively analyzed, after excluding 48 patients in whom at least 1 ITA was used as the inflow conduit of the other graft. A total of 461 pairs were matched using propensity scores calculated from 28 preoperative variables (C statistic, 0.62). The study end-points were repeat revascularization, cardiac death, and major adverse cardiac and cerebrovascular events (MACCE). Results: The average numbers of total distal anastomoses and distal anastomoses of the RITA were significantly higher in patients undergoing free RITA grafting than in those undergoing in situ RITA grafting (4.5±1.1 versus 4.3±1.1, P=0.003 and 1.5±0.6 versus 1.1±0.2, P&lt;0.001, respectively). In patients undergoing free RITA grafting, the RITA was used as an aortocoronary bypass graft in 68 (14.8%) and as a composite graft in 393 (85.2%) patients. There was no significant difference in the postoperative mortality and morbidity between the groups. The mean follow-up period was 4.4 years. The Kaplan-Meier estimated cumulative survival rate free from repeat revascularization, cardiac death, and MACCE at 5 years in patients undergoing in situ versus free RITA grafting, was 89.5±1.6% versus 89.9±1.6% (P=0.519), 97.3±0.9% versus 98.0±0.7% (P=0.736), and 73.7±2.3% versus 75.3±2.4% (P=0.783), respectively. Conclusions: The long-term clinical outcomes in patients undergoing free RITA grafting were comparable to those in patients undergoing in situ RITA grafting. Free RITA grafting is the effective surgical alternative to in situ RITA grafting for CABG in patients with multivessel coronary artery disease.

What Is the Best Proximal Anastomosis for the Free Right Internal Thoracic Artery during Bilateral Internal Thoracic Artery Revascularization? A Prospective, Randomized Study

Objective. Bilateral internal thoracic artery (BITA) grafting provides improved graft patency and potential survival advantage in selected patients as compared to single left internal thoracic artery (LITA) revascularization. The ideal functional BITA configuration remains controversial. Methods. Patients undergoing planned BITA revascularization with greater than 75% stenosis in both the left anterior descending artery (LAD) and in a circumflex branch were prospectively randomized to one of two proximal free right internal thoracic artery (RITA) connections directly off the aorta (Ao) (n = 12) or as a “t” graft off the LITA (t) (n = 12). The LITA was placed to the LAD in all cases, and the RITA was placed to a single lateral wall vessel. Intraoperative transit time flow measurements of all arterial grafts were performed, and RITA fractional flow parameters were compared between the 2 groups. Results. There were no differences in preoperative patient variables between the two groups. Cross-clamp times (91.5 + 15.3 versus 68.0 + 12.5 minutes, P < 0.01) and total cardiopulmonary bypass times (109.0 + 16.2 versus 85.0 + 15.1 minutes, P < 0.01) were shorter in the t group. The Ao group demonstrated significantly higher mean RITA flow (38.3 ± 13.5 versus 22.1 ± 9.5, P < 0.01), mean RITA conductance (flow/mean arterial pressure) (0.45 ± 0.16 versus 0.28 ± 0.11, P < 0.01), RITA fractional flow (0.52 ± 0.15 versus 0.36 ± 0.11, P < 0.01), and RITA fractional conductance (0.51 ± 0.15 versus 0.36 ± 0.11, P < 0.01) than the “t” grafted patients. Thirty-day mortality and wound infection were 0% for each group. Over an average of 42.8 + 6.6 months of followup there were no mortalities in either group. Repeat angiography were performed in 4 patients (33%) in the Ao group and 2 patients in the t group (16%). One occluded RITA graft and one ostial RITA stenosis were detected in the Ao group. Conclusions. Acute flow measurements indicate that the free RITA anastomosed to the aorta provides more acute fractional RITA flow than composite “t” grafting to the LITA. Longer-term angiographic and clinical followup are necessary to determine the consequences of these acute hemodynamic findings.

The second best arterial graft: A propensity analysis of the radial artery versus the free right internal thoracic artery to bypass the circumflex coronary artery

We sought to determine if the radial artery (RA) or the free right internal thoracic artery (RITA) is the better conduit to bypass the circumflex coronary artery during coronary artery bypass grafting (CABG) using the left internal thoracic artery (LITA). Propensity matching was performed on 2488 CABG-LITA patients from 2 affiliated centers, resulting in 528 pairs who received either a RA at one center or a free RITA at the other center to bypass the circumflex coronary artery from 1995 to 2009. Kaplan Meier estimated 1-, 5-, 10-, and 15-year survival rates were 99%, 95%, 85%, and 76% for RA patients, respectively, and 97%, 92%, 80%, and 71% for RITA patients, respectively (P=.060). Major adverse events (MAEs) were fewer in the RA group (7.6% vs 14.0%; P=.001) and use of the RA was a significant predictor of reduced MAEs (odds ratio [OR], 0.48; P=.002) in all patients and especially in diabetic (OR, 0.32; P=.003), older (OR, 0.40; P=.009), obese (OR, 0.15; P<.001), and chronic obstructive pulmonary disease (COPD) (OR, 0.05; P=.016) patients. However, survival was better with RA only in COPD (hazard ratio, 0.49; P=.045) and older (hazard ratio, 0.71; P=.050) patients. Overall RA patency (83.9%) was similar to RITA patency (87.4%) at a mean of 5.1 ± 3.8 years (P=.155). Long-term survival is similar in CABG-LITA patients using either a RA or free RITA graft to bypass the circumflex coronary artery. RA grafting has fewer MAEs, a similar patency to RITA, and improves survival in older and COPD patients. The choice of the second arterial conduit should be guided by patient profiles and surgeon preferences.

Mid-term results of the Radial Artery Patency and Clinical Outcomes randomized trial.

The radial artery (RA), as an alternative to the saphenous vein or the right internal thoracic artery (RITA) for coronary artery bypass grafting, has gained considerable interest over the years. A randomized controlled trial was undertaken to assess the suitability of the radial artery as a conduit. The Radial Artery Patency and Clinical Outcomes (RAPCO) trial is a double-armed randomized controlled trial comparing the RA with the free RITA in a younger cohort of patients undergoing elective coronary bypass surgery, and the RA with the saphenous vein in an older group. The trial conduit was grafted to the most important coronary target after the left anterior descending artery, which received the gold standard left internal thoracic artery. Clinical outcomes and angiographic patency up to 10 years was recorded during careful follow up, with annual clinical review and a program of randomly assigned, staggered angiography. The final trial results will be available in 2014. Mid-trial results have shown equivalent survival and event-free survival and graft patency in both arms at median follow up of approximately 6 years. The demographic and clinical data, pre- and postoperative angiographic findings of the trial database have led to a number of substudies focusing on the role of lipid exposure in patency and disease progression, the fate of moderate lesions when grafted or left alone, patterns of disease regression, and patient satisfaction with graft harvest sites. While the final analysis of the primary trial end points is eagerly awaited, the additional insight into the natural history of grafted coronary artery disease with modern secondary prevention will be of considerable interest.

Is the mid-term outcome of free right internal thoracic artery with a proximal anastomosis modification inferior to in situ right internal thoracic artery?

We investigated the mid-term results of free right internal thoracic artery (RITA) grafts used in an aorto-coronary fashion with a modified proximal anastomosis. The subjects were 214 patients who underwent coronary artery bypass grafting with anastomosis to the left circumflex arteries using the RITA as a free graft (Group A: 158 patients) or an in situ graft (Group B: 56 patients). In Group A, the proximal end of the free RITA was anastomosed onto the ascending aorta interposing free graft tissue or to part of its own tissue as a cuff. The number of RITA anastomoses was 1.38±0.50 in Group A and 1.04±0.19 in Group B (P<0.001). The relationship between perioperative variables and mid-term outcomes was assessed using Cox proportional hazard models. Survival was not associated with the way the RITA graft was performed (Hazard Ratio 5.26, 95% CI 0.52-53.1, P=0.159), however, the number of cardiac events was decreased in Group A (Hazard Ratio 2.55, 95% CI 1.03-6.33, P=0.043). The graft patency was evaluated in 187 of 214 patients, and at 1, 3 and 5years was 97.0, 97.0 and 97.0% in Group A, and 97.9, 92.5 and 80.5% in Group B (P=0.378), respectively. By modifying the proximal anastomosis of the free RITA, cardiac events may be decreased, while survival and graft patency comparable with in situ RITA can be obtained, and a significantly larger number of targets can be revascularized.

Sequential free right internal thoracic artery grafting for multivessel coronary artery bypass grafting

This study compared early and follow-up angiographic results of individual and sequential grafting with the free right internal thoracic artery (RITA). We reviewed 334 patients who underwent multivessel coronary artery bypass grafting with the free RITA between September 2004 and December 2010. The free RITA was used for individual grafting in 179 patients and for sequential grafting in 155 patients. We compared operative and postoperative variables and early and follow-up angiographic patency rates of distal anastomoses of the free RITA between the groups. The mean number of distal anastomoses in sequential grafting was 2.2 ± 0.4. The inflow of the free RITA included the aorta (27.4%) and other grafts (72.6%) in the individual group. The inflow of free RITA was exclusively other grafts in the sequential group. Operative mortality and incidence of postoperative complications were not significantly different between groups. Overall patency rate of distal anastomosis of the free RITA was 99.1% at early angiography and 91.8% at follow-up angiography, and the rate did not differ significantly between individual and sequential grafting (early, 98.6% vs 99.3%; follow-up, 93.0% vs 91.2%). Multivessel coronary artery bypass grafting with the free RITA is safe and useful. Patency rates of distal anastomoses are similar between individual and sequential grafting with the free RITA at early and follow-up angiography. When the RITA cannot be used as an in situ graft for multiple anastomoses, sequential grafting with the free RITA should be considered.

The Right Internal Thoracic Artery: The Forgotten Conduit—5,766 Patients and 991 Angiograms

The right internal thoracic artery (RITA) is biologically identical to the left ITA, yet is rarely used in coronary artery bypass graft surgery (CABG). We examined the results and long-term patency of RITA grafts. Between 1986 and 2008, 991 consecutive RITA graft angiograms for postoperative cardiac symptoms were evaluated by two independent observers. Grafts were considered nonpatent if they had a greater than 80% stenosis, string sign, or total occlusion. Patency was examined over time by coronary territory, whether in situ or free RITA, and compared with other conduits. Clinical results were collected prospectively and by the National Death Index. A total of 5,766 patients had a RITA graft as part of a bilateral ITA CABG procedure. Operative mortality was 1.1%; deep sternal infection 1.5%. Of 7,780 coronary conduits studied, 991 RITA conduits were examined; a mean of 100±60 months postoperatively (1 to 288 months). Overall ten-year RITA patency was 90%. The RITA graft patency to the left anterior descending artery (LAD; n=149) was 95% at 10 years and 90% at 15 years. Ten-year RITA patency to the circumflex marginal (Cx; n=436) was 91%, right coronary artery (n=199) was 84% (p<0.001), and posterior descending artery (n=207) was 86%. Ten-year RITA and LITA patencies to the LAD were identical (95% vs 96%) and to the Cx (91% vs 89%), respectively. In situ RITA (n=450) and free RITA (n=541) had similar ten-year patencies (89% vs 91%; p=0.44). The RITA patency was always better than the radial artery (p<0.01) and saphenous vein grafts (p<0.001). Atheromatous changes were not seen in the RITA angiograms. Ten-year survival of patients with RITA and LITA for triple-vessel coronary disease was 89%. Late patencies of RITA are excellent, equivalent to the LITA for identical territories, always better than radial arteries and saphenous vein grafts, and remain free of atheroma. Use of RITA in addition to LITA is associated with excellent survival in triple-vessel coronary disease. More extensive use of the RITA in CABG is recommended.

Multiple Arterial Revascularization Using the Tangential K-Graft Technique

The tangential K graft is a comfortable surgical technique aiming to increase cardiac surgeons' versatility in performing multiple arterial grafting using only two arterial conduits. One end of the free graft--either the right internal thoracic artery (RITA) or the radial artery (RA)--is attached to a marginal circumflex branch. Its other end is anastomosed end to side to a diagonal branch. After the left internal thoracic artery (LITA) is attached to the left anterior descending coronary artery, a wide-open side-to-side LITA to free RITA or RA anastomosis--resembling the letter K--is constructed.

Total Arterial Myocardial Revascularization Using Composite and Sequential Grafting With the Off-Pump Technique

Multiple arterial myocardial revascularizations are increasingly undertaken using off-pump techniques; however, various arterial grafting techniques are utilized. This study aimed to review the outcome of combining arterial composite and sequential grafting with off-pump techniques. We retrospectively reviewed the records of 107 consecutive patients who underwent coronary bypass surgery with off-pump and arterial composite grafting techniques between April 2001 and March 2004. The left internal thoracic artery (LITA) was harvested in all patients, and the right internal thoracic artery (RITA), the radial artery (RA), and the gastroepiploic artery (GEA) were harvested in 69 patients, in 83 patients, and in 53 patients, respectively. Early postoperative angiograms were evaluated in 97 patients. There were 488 distal anastomoses, an average of 4.5 per patient. Forty-four in situ LITAs were used as LITA Y-composite grafts with a free RITA (n = 19), RA (n = 24), or free GEA (n = 1). Forty-three in situ RITAs were used as RITA-RA grafts (n = 42) or a RITA-GEA graft (n = 1). Twenty-one in situ GEAs were used as composite grafts with the RA (n = 17) or a free RITA (n = 4). There were no hospital deaths. The patency of the LITA was 100%, and that of the RA was 97.3%, while patencies of both in situ and free RITA and GEA were 100%. During the follow-up period (mean: 22.1 months), there were 3 late deaths, but none were cardiac related. Total arterial revascularization with composite and sequential grafting is a safe and effective technique in patients undergoing off-pump coronary artery bypass surgery.

Revascularization of the Right Coronary Artery in Bilateral Internal Thoracic Artery Grafting

Bilateral internal thoracic artery (BITA) grafting with a composite T-graft enables right coronary artery (RCA) system revascularization with the distal end of the free right internal thoracic artery (RITA). This study compares this grafting technique to left-sided BITA grafting and RCA revascularization with the right gastroepiploic artery (RGEA) and saphenous vein grafts (SVG). From April 1996 to July 1999, 1000 consecutive patients underwent left-sided revascularization with BITA. In 231 patients RCA grafting was performed with free RITA, in 246 with RGEA, in 142 with SVG, and 381 did not receive any graft to the RCA (no-graft group). Female gender, old age (> 70), emergency, and congestive heart failure were less prevalent in the RGEA group, and prior percutaneous transluminal coronary angioplasty was more prevalent in the no-graft group. Thirty-day mortality (3.6%, 4.9%, 2%, and 3.4% in the RITA, SVG, RGEA, and no-graft groups, respectively) and occurrence of perioperative complications (sternal infection, myocardial infarction, cerebrovascular accident, and bleeding) were similar. Overall, however, the trend was toward a higher complication rate in the RITA group (10.3%, 4.9%, 5.6%, and 7.3% respectively, p = 0.06). Midterm follow-up (40 to 78 months) showed similar 6-year survival (Kaplan-Meier) (88%, 87%, 89.5%, and 85.5%, respectively) and similar return of angina (10.8%, 6.3%, 10.6%, and 9.5%, respectively) in the four groups. Early and midterm results in patients undergoing left-sided BITA grafting are not affected by the conduit used for RCA grafting.

Factors affecting patency of internal thoracic artery graft: clinical and angiographic study in 1434 symptomatic patients operated between 1982 and 2002.

The purpose is to define factors influencing long-term patency of the internal thoracic artery (ITA) to optimize the operative strategy. 1482 left internal thoracic artery (LITA) and 636 right internal thoracic artery (RITA) symptom-directed angiograms were studied in 1434 patients. Data were prospectively collected from patients who had primary coronary artery bypass surgery during the period 1982-2002. The mean age of patients was 59 years; 85% were male. The mean period from operation to re-angiogram was 80 months. LITA was grafted to left anterior descending coronary artery (LAD) in 82% of cases, RITA to right coronary artery (RCA) in 40% and circumflex artery in 35% of cases. Graft failure was defined as > or =80% stenosis. 96.3% of LITA and 88.1% of RITA grafts were patent. No patient variables were significantly associated with graft patency (age, gender, diabetes, hypertension, LVEF, NYHA, AMI). Target coronary artery was associated with patency of both LITA and RITA grafts with maximum patency when grafted to LAD (P = 0.02) RITA had the worst patency to RCA, patency for the left system was identical to LITA. Proximal anastomosis to aorta (free RITA) had significantly better patency when compared with in situ RITA to RCA system (P = 0.005) while similar patency when grafted to left system. ITA diameter and target artery diameter were not associated with graft patency. Recent operations had better RITA patency (P = 0.03). The interval from operation to angiogram was not associated with ITA patency (96% patency for LITA and 88% patency for RITA, remained stable when studied at <1, 1-4, 5-9, 10-14 and >15 years). Even in a patient cohort that had adverse symptoms, excellent LITA and RITA patency was achieved which almost remained constant through all time intervals studied.

Patencies of 2,127 arterial to coronary conduits over 15 years

Background Use of arterial grafts in coronary surgery is based on the excellent patency of the left internal thoracic artery (LITA) and an expectation that other arterial grafts—right internal thoracic artery (RITA) and radial artery (RA)—will give similar patencies, superior to saphenous vein. We examined patencies of arterial grafts in a practice with extensive use for more than 15 years. Methods Consecutive postoperative angiograms of 2,127 arterial/coronary conduits were evaluated. Angiograms were performed for cardiac symptoms. Assessment was by two observers. String signs were considered as occlusions. Results There were 2,127 arterial conduits. Overall patencies were as follows: LITA, 96.4% (1,296 of 1,345); RITA, 88.3% (534 of 605); aortocoronary RA, 89.3% (158 of 177). The LITA patency to the left anterior descending artery was 97.1% (1,131 of 1,165); to the obtuse marginal artery it was 91.7% (165 of 180; p 0.01). The RITA pedicled graft patency was 86% (275 of 321) compared with free RITA, 91% (259 of 284; p = not significant). For RITA there was a hierarchy of patency for coronary territory grafted (left anterior descending artery best, right coronary/posterior descending artery worst) and for degree of coronary stenosis: if stenosis was less than 60%, patency was 65% (47 of 72); if stenosis was more than 60%, patency was 90.9% (485 of 533; p = 0.0001). Similarly for the radial artery there was higher patency with greater coronary stenosis. The LITA patency at 5 years was 98%, at 10 years it was 95%, and at 15 years it was 88%. The RITA patency at 5 years was 96%, at 10 years it was 81%, and at 15 years it was 65%. The radial artery patency at 1 year was 96% and at 4 years it was 89%. For 3,714 vein grafts also studied overall patency was 61% (2,266 of 3,214) with patencies of 95% at 5 years, 71% at 10 years, and 32% at 15 years. Conclusions Excellent long-term patencies of arterial grafts are noted, superior to those of vein grafts. Patencies were influenced by conduit, by distribution, and by coronary artery stenosis.

Adequacy of flow capacity of bilateral internal thoracic artery T graft

Background. With the T graft configuration, multiple arterial revascularization can be accomplished using bilateral internal thoracic arteries. However, concern remains about the flow capacity of the main stem of the left internal thoracic artery (LITA). Methods. Forty patients who underwent multiple revascularization of the entire territory of the left coronary system with a T graft were investigated. Six months after the operation, they were examined angiographically. During the same period, dobutamine stress echocardiography was performed to evaluate the adequacy of the myocardial blood supply from the T graft. The T graft revascularized two branches in 5 patients, three branches in 23, four branches in 11, and five branches in 1 of the left coronary system. Other conduits were used if revascularization was required for the right coronary system. Results. Complete revascularization was achieved in the left coronary territory in all patients. The LITA main stem showed a wide lumen in all patients. Luminal narrowing was present in the distal segment of the LITA in 3 patients. The right internal thoracic artery (RITA) was patent in all patients, whereas luminal narrowing was observed in the distal segment of the RITA in 5 patients. No patient exhibited ischemic wall motion abnormality in the anteroseptal, lateral, or posterolateral region of the left ventricle where the T graft revascularized. Eight patients showed ischemic response in the inferoposterior region, that is, the territory of the right coronary artery. Conclusions. The LITA main stem, forming a T-graft configuration with the free RITA, has an adequate flow reserve to supply at least the entire left coronary arterial system with sufficient blood. Therefore, multiple coronary revascularization using the T-graft technique is feasible.

A new strategy of total arterial revascularization

We report a new strategy of total arterial revascularization based on bilateral internal thoracic arteries (ITAs) and a radial artery (RA). The technique employs a graft extension of the proximal third of the right internal thoracic artery (RITA) with the RA, in combination with the T-graft technique, by which the lower two-thirds of the free RITA is anastomosed to the side of the left internal thoracic artery (LITA).

Results of 1,454 Free Right Internal Thoracic Artery-to-Coronary Artery Grafts

After beginning our use of bilateral internal thoracic artery grafts in 1985, we found the pedicled right internal thoracic artery grafts limiting, and expanded the application of the right internal thoracic artery by elective use as a free graft. We evaluated the results of patients having a free right internal thoracic artery (FRITA)-to-coronary artery graft as part of their coronary revascularization. From 1986 to 1995, 1,454 patients had a FRITA graft. Preoperative characteristics included mean age, 58.8 years (range 29 to 84 years); non-insulin-dependent diabetes, 116 (8%); insulin-dependent diabetes, 7 (0.5%); left ventricular ejection fraction from 0.30 to 0.40, 159 (11%); left ventricular ejection fraction less than 0.30, 14 (1%); and unstable angina, 144 (9.9%). In 11 patients the FRITA was the only graft, in 1,443 a left internal thoracic graft was also used and revascularization completed with additional arterial and vein grafts. There were 3.3 +/- 1.1 distal anastomoses per patient, the aortic clamp time was 49 +/- 12 minutes, and bypass time was 69 +/- 16 minutes. The FRITA was used to reach the circumflex marginal arteries in 718 patients (49.5%), posterior descending artery in 286 (19.7%), diagonal or intermediate in 172 (11.8%), left anterior descending artery in 119 (8.1%), right coronary artery in 115 (7.9%), and left ventricular branch of right coronary artery in 44 (3%). The proximal anastomosis was directly on the aorta in 1,441, other arterial graft in 8, and vein graft in 5. Operative mortality was 13 patients (0.9%); stroke occurred in 14 patients (1%) and myocardial infarction in 19 (1.3%). The peak creatine kinase myocardial isoenzyme serum level was 20.6 +/- 13.6 IU/L. Complications included sternal infection in 18 patients (1.2%) and reoperation for hemorrhage in 23 (1.6%). Survival at 5 and 7 years, respectively, was 96% +/- 2.1% and 94% +/- 2.5%. In 71 patients with a FRITA studied at a mean of 41.5 +/- 14 months postoperatively for recurrent symptoms, 67 FRITA grafts were widely patent (94.5%), 3 displayed a string sign, and 1 was totally occluded. Use of the right internal thoracic artery as a free graft is safe and effective and allows greater flexibility in arterial coronary revascularization.