Kwang Ree Cho

Bilateral skeletonized internal thoracic artery graftings in off-pump coronary artery bypass: early result of Y versus in situ grafts

BACKGROUND Use of bilateral skeletonized internal thoracic arteries (ITAs) in off-pump coronary artery bypass (OPCAB) retains several advantages that may eventually result in better patient outcomes. We compared the early results of OPCAB using bilateral ITAs as Y grafts with results of OPCAB using bilateral ITAs as in situ grafts. METHODS A total of 223 consecutive patients who underwent OPCAB using bilateral skeletonized ITAs as Y grafts (group I, n = 113) or in situ grafts (group II, n = 110) were studied. RESULTS Both the number of distal anastomoses per patient and the number of distal anastomoses per bilateral ITA were higher in group I (3.5 +/- 1.0 and 2.9 +/- 0.7) than in group II (3.0 +/- 0.7 and 2.4 +/- 0.5) (p < 0.01). Hospital mortality was 1.8% (2/113) in group I and 0.9% (1/110) in group II (p = ns). There were no differences in postoperative complications including atrial fibrillation (13.3% vs 10.9%), perioperative myocardial infarction (0.9% vs 2.7%), mediastinitis (0.9% vs 1.8%), and hypoperfusion syndrome (0.9% vs 0%) between groups I and II (p = ns). Postoperative coronary angiographies performed in 110 patients in group I and 108 patients in group II showed 99.0% (382/386) overall patency and 99.4% (319/321) patency for distal anastomoses using ITAs in group I, and 98.1% (312/318) overall patency and 98.1% (258/263) patency for distal anastomoses using ITA in group II. There were no significant differences in graft patency rates between the two groups (p = ns). CONCLUSIONS Our results demonstrate that OPCAB using bilateral skeletonized ITAs is technically feasible, with excellent graft patency. Using bilateral skeletonized ITAs as Y grafts increases the number of distal anastomoses that can be performed and does not cause additional postoperative morbidity.

Midterm angiographic follow-up after off-pump coronary artery bypass: Serial comparison using early, 1-year, and 5-year postoperative angiograms

OBJECTIVE We analyzed the angiographic changes of the anastomotic sites at three time points for 5 years after off-pump coronary artery bypass surgery. METHODS Of the 402 patients who underwent off-pump coronary artery bypass surgery between January 1998 and December 2001, 240 patients who received the early, 1-year, and 5-year follow-up coronary angiograms regardless of the patients anginal symptoms were studied. Morphologic changes of grafts were traced by the FitzGibbon grading system. RESULTS Overall graft patency rates (FitzGibbon grade A+B) at early, 1-year, and 5-year angiography were 98.6%, 91.9%, and 88.3%, respectively. Graft patency rates in the left anterior descending artery, left circumflex artery, and right coronary artery territories were similar at early angiograms (P = .162). However, graft patency rate in the left anterior descending artery territory was higher than that in the left circumflex artery and right coronary artery territories at both the 1-year (P < .001) and 5-year (P < .001) angiograms. Of the 31 FitzGibbon grade B arterial grafts (internal thoracic artery and right gastroepiploic artery) at early angiography, 10 became occluded and 19 became grade A at 5-year angiography. In the saphenous vein grafts, grade B lesions gradually increased during the 5 postoperative years (2.6% vs 6.5% vs 13.3%). CONCLUSIONS Midterm angiographic follow-up demonstrated acceptable patency rates of grafts after off-pump coronary artery bypass surgery. Approximately half of the FitzGibbon grade B arterial grafts in the early angiograms became grade A at 5 years after surgery, but the proportion of grade B saphenous vein grafts gradually increased over the 5 postoperative years.

Bilateral Internal Thoracic Artery In Situ Versus Y-Composite Graftings: Five-Year Angiographic Patency and Long-Term Clinical Outcomes

BACKGROUND We compared 5-year graft patency rates and long-term clinical outcomes after off-pump coronary artery bypass grafting (OPCAB) using bilateral internal thoracic arteries (ITAs) as in situ grafts with those using bilateral ITAs as a Y-composite graft. METHODS Of 398 patients who underwent OPCAB, bilateral ITAs were used as in situ grafts in 164 patients and as a Y-composite graft in 234 patients. A propensity score-matched analysis was used to match patients using bilateral ITA in situ grafts (group I, n=110) with patients using bilateral ITA Y-composite grafts (group Y, n=110). Postoperative early, 1-year, and 5-year angiographic patency rates and long-term clinical outcomes during follow-up of 104 (1 to 149) months were compared. RESULTS There were no differences in operative mortalities (2 of 110 vs 1 of 110; p>0.999) and postoperative complications between groups I and Y. Early, 1-year, and 5-year postoperative angiographies showed no significant differences in bilateral ITA graft patency rates between groups I and Y (early, 98.2% vs 99.3%, p=0.450; 1-year, 92.5% vs 95.7%, p=0.138; 5-year, 92.5% vs 92.4%, p=0.978). No differences in overall survival (p=0.347) and freedom from cardiac death (p=0.780) rates were observed between the groups; 10-year freedom from cardiac death rates were 95.1% and 94.2% in groups I and Y, respectively. Reintervention-free survival (p=0.379) and major adverse cardiac event-free survival (p=0.338) rates were also similar between the groups. CONCLUSIONS The OPCAB using both bilateral ITA configurations demonstrated that there were no differences in terms of 5-year patency rates and long-term clinical outcomes between the groups.

Therapeutic angiogenesis using naked DNA expressing two isoforms of the hepatocyte growth factor in a porcine acute myocardial infarction model

OBJECTIVE We evaluated the potency of therapeutic angiogenesis using intramyocardial injection of naked DNA expressing two isoforms of hepatocyte growth factor (pCK-HGF-X7) in a porcine myocardial infarction model. METHODS Four weeks after left anterior descending coronary artery ligation, 14 pigs were allocated to pCK-Null (negative control, n=7) or pCK-HGF-X7 (n=7) treatment groups. Gated myocardial single photon emission computed tomography was performed 4 and 8 weeks following coronary ligation. The effect of pCK-HGF-X7 on capillary density in the gene-injected myocardium was examined by histological analysis using alkaline phosphatase staining. RESULTS Segmental myocardial perfusion of the underperfused area (< or =70%) from coronary ligation increased in the pCK-HGF-X7 group (p=0.051), without significant differences in changes over time between the two groups (p=0.54). Systolic wall thickening (p=0.001), left ventricular end-diastolic (p=0.045) and end-systolic volumes (p=0.009), and left ventricular ejection fraction (p=0.041) changed in both groups without significant differences in changes over time between the two groups. The increase in the left stoke volume was higher in the pCK-HGF-X7 group than in the pCK-Null group (p=0.008). Histological analysis showed that capillary density was significantly higher in the pCK-HGF-X7 group than the pCK-Null group (p<0.001). CONCLUSION Intramyocardial injection of pCK-HGF-X7 induced significant angiogenesis at infarct-border zone, and increased the left ventricular stroke volume probably caused by reverse remodeling process.

Comparison of Right Internal Thoracic Artery and Right Gastroepiploic Artery Y Grafts Anastomosed to the Left Internal Thoracic Artery

BACKGROUND Early and 1-year results of arterial Y composite grafts anastomosed to the in situ left internal thoracic artery were studied. METHODS Three hundred twelve patients who underwent off-pump coronary artery bypass using arterial Y composite grafts for revascularization of the left coronary artery territory were analyzed. A skeletonized right internal thoracic artery (RITA) or right gastroepiploic artery (RGEA) was anastomosed to the side of the left internal thoracic artery to construct a Y composite graft. Propensity-matched analysis was used to match patients using RITA (RITA group, n = 102) with patients using RGEA (RGEA group, n = 102). Postoperative coronary angiographies were performed early (200 of 204; 1.8 +/- 1.7 days) and 1 year (171 of 204, 11.3 +/- 2.5 months) postoperatively. RESULTS There were no differences in postoperative mortalities (1 of 102 versus 2 of 102; p = 1.000) and morbidities including atrial fibrillation, mediastinitis, and perioperative myocardial infarction between the RITA and RGEA groups (not significant). Early and 1-year postoperative angiographies showed that there were no significant differences in patency rate between the two groups (early, 99.4% versus 99.3%; p = 1.000; 1-year, 95.4% versus 97.4%; p = 0.251). When the early and 1-year patency rates were compared based on the side-arm graft used, there were no differences in patency rates of RITA versus RGEA grafts between the two groups (early, 99.4% versus 100%; p = 1.000; 1-year, 96.5% versus 97.7%; p = 0.724). CONCLUSIONS Construction of Y composite grafts using the RITA or RGEA showed comparable results including patency rates early and 1 year postoperatively.

Initial experience of an automated anastomotic distal device in off-pump CABG.

BACKGROUND Recent progress in minimally invasive technology in the field of coronary artery bypass grafting (CABG) stimulates interest in anastomotic devices used to facilitate distal coronary anastomosis. We assessed the feasibility of the automated anastomotic distal device (AADD) on arterial grafts in patients who underwent off-pump CABG (OPCAB) and evaluated the early anastomotic patency and clinical results of the AADD based on an elliptical nitinol ring with attached 8 pins. METHODS Fourteen patients scheduled for multivessel OPCAB using arterial grafts between August 2003 and February 2004 were studied. Among 19 patients enrolled, 5 patients were excluded: 2 patients because of failure of graft flaring onto the implant pins, 2 because of small and diseased target coronary artery (<1.5 mm in diameter), and 1 because of conversion to cardiopulmonary bypass. The distal anastomosis using the AADD was performed for the nondominant coronary artery. RESULTS The total number of distal anastomoses was 48 (34 hand-sewn sutures and 14 AADD sutures), and the average number of distal anastomoses per patient was 3.4 +/- 1.0. The grafts used for the AADD were right gastroepiploic artery (RGEA) in 10 patients, saphenous vein anastomosed to the end of the RGEA in 2 patients, and internal thoracic artery in 2 patients. The average time required for distal anastomosis using the AADD (from arteriotomy to anastomosis completion) was 2.9 +/- 0.7 minutes (range, 1.5-4 minutes). The mean flow and pulsatility index of the AADD grafts measured intraoperatively by transit time flow measurement were 20.0 +/- 10.3 mL/min and 2.4 =/- 1.2, respectively. Early postoperative coronary angiographies demonstrated widely patent grafts in 32 of 34 hand-sewn anastomoses and 13 of 14 AADD sutures. There were no adverse events related to the use of the device. CONCLUSIONS Our initial experience demonstrated that distal anastomosis using the AADD was feasible in most of the patients who underwent OPCAB using arterial grafts. Distal anastomosis using the AADD had the advantage of shortening the actual suturing duration and might provide a method for standardizing the anastomotic procedure.

Right Gastroepiploic Artery Graft for Myocardial Revascularization: Prevalence of Atherosclerosis and Availability as a Conduit

BACKGROUND We evaluated prevalence of atherosclerosis and availability of right gastroepiploic artery graft in patients undergoing coronary artery bypass graft surgery. METHODS Among the 1,579 patients who underwent isolated coronary artery bypass grafting between January 1999 and December 2008, we opened the peritoneum to examine the right gastroepiploic artery for use as a graft in 1,128 patients (71.4%). A computer-based patient database system was utilized for this retrospective study. RESULTS Of 1,128 patients, 139 patients (12.3%) had atherosclerotic right gastroepiploic arteries at gross examination. Seventy-three of 139 atherosclerotic right gastroepiploic arteries had multiple or diffuse atherosclerotic lesions that precluded their use as a bypass graft; the remaining 66 right gastroepiploic arteries were used as a bypass graft including the atheromatous segment or after exclusion of the atherosclerotic segment. Another 60 nonatherosclerotic right gastroepiploic arteries were unavailable to use as a graft because of their short length, small caliber, and weak pulsation. Overall availability of the right gastroepiploic arteries as a graft was 88.2% (995 of 1,128). Multivariable logistic regression analysis showed older age (≥65 years; p < 0.001), insulin-treated diabetes mellitus (p = 0.001), and chronic renal failure (p < 0.001) as independent risk factors for atherosclerosis. CONCLUSIONS The prevalence of atherosclerosis and availability of the right gastroepiploic artery graft in patients undergoing isolated coronary artery bypass grafting was 12.3% and 88.2%, respectively. Older age (≥65 years), insulin-treated diabetes mellitus, and chronic renal failure were identified as independent predictors for the atherosclerotic right gastroepiploic artery.