Susumu Manabe

Extensive Reconstruction of the Left Anterior Descending Coronary Artery With an Internal Thoracic Artery Graft

BACKGROUND Revascularization of the diffusely diseased coronary artery is a big challenge for both cardiologists and cardiac surgeons. Long reconstruction of the diffusely diseased vessel may be a useful surgical option. The aim of this study is to assess clinical and angiographic outcomes of extensive reconstruction (≥4 cm) of the left anterior descending coronary artery (LAD) using an internal thoracic artery (ITA) graft with or without endarterectomy. METHODS We retrospectively reviewed 213 patients who underwent extensive reconstruction of the LAD using an ITA graft between September 2004 and July 2009. The diffusely diseased LAD was extensively incised, additional endarterectomy was performed if necessary, and then the LAD was reconstructed with an ITA graft in a long on-lay fashion. Early and 1-year postoperative angiography was performed in 188 patients (88.3%) and 152 patients (71.4%), respectively. RESULTS The mean length of the reconstructed LAD was 5.4 ± 1.2 cm. Endarterectomy was performed in 46.0% of the patients. The operative mortality was 1.4%. Low cardiac output and perioperative myocardial infarction were observed in 3.3 and 5.2% of the patients, respectively. Freedom from death and other cardiac or cerebrovascular events was 91.5 ± 2.2% at 3 years. The early and 1-year patency rates of the ITA to LAD grafting were 95.7% and 93.4%, respectively. CONCLUSIONS Extensive reconstruction of the diffusely diseased LAD using an ITA graft could be performed safely. Early and 1-year angiographic outcome were excellent. This surgical revascularization is an useful option for revascularization of the diffuse coronary artery disease.

Coronary artery bypass surgery versus percutaneous coronary artery intervention in patients on chronic hemodialysis: does a drug-eluting stent have an impact on clinical outcome?

Abstract  Coronary revascularization methods continue to be refined, and the emergence of the drug‐eluting stent (DES) has especially changed clinical practice related to ischemic heart disease. For chronic hemodialysis (HD) patients, however, the impact of DES on clinical outcome is yet to be determined. Forty‐six consecutive chronic HD patients who underwent myocardial revascularization in our institute were retrospectively reviewed. Twenty‐eight patients underwent coronary artery bypass surgery (CABG) and 18 patients underwent percutaneous coronary artery intervention (PCI). Patient characteristics were similar between the two groups. In the CABG group, bilateral internal thoracic artery (ITA) bypass grafting was performed in 27 patients and off‐pump CABG was performed in 20 patients. In the PCI group, a DES was used in 12 patients. The number of coronary vessels treated per patient was higher in the CABG group (CABG: 4.25 ± 1.32 vs. PCI: 1.44 ± 0.78; p < 0.001). Two‐year survival rates were similar between the two groups (CABG: 94.1% vs. PCI: 73.9%; p = 0.41), but major adverse cardiac event‐free survival (CABG: 85.9% vs. PCI: 37.1%; p = 0.001) and angina‐free survival (CABG: 84.9% vs. PCI: 28.9%; p < 0.001) rates were significantly higher in the CABG group. The one‐year patency rate for the CABG grafts was 93.3% (left ITA: 100%, right ITA: 84.6%, sapenous vein: 90.9%, gastro‐epiploic artery: 100%), and six‐month restenosis rate for PCI was 57.1% (balloon angio‐plasty: 75%, bare metal stent 40%, DES: 58.3%). Even in the era of DES, clinical results favored CABG. The difference in clinical results is due to the sustainability of successful revascularization.

Increased Graft Occlusion or String Sign in Composite Arterial Grafting for Mildly Stenosed Target Vessels

BACKGROUND Composite grafting is a useful technique that avoids the need for aortic manipulation and enables a wide range of target vessels to be revascularized, effectively using the limited arterial grafts available. However, it has not been clarified whether composite grafting can achieve angiographic outcomes equivalent to those obtained with individual grafting for specific target vessels. METHODS We retrospectively reviewed 830 distal arterial graft anastomoses in 256 patients who underwent off-pump coronary artery bypass surgery and also underwent 1-year follow-up coronary angiograms. Four hundred and ten anastomoses using a composite grafting technique were compared with 420 anastomoses using individual grafting. RESULTS In target vessels with mild stenosis, the incidence of graft occlusion or string sign was significantly higher in composite internal thoracic arteries (ITA) than in individual ITA grafts (composite 20.3% versus individual 7.3%; p = 0.018) and showed a higher tendency in composite radial arteries (RA) than in individual RA grafts (59.3% versus 36.4%, p = 0.09). In contrast, the incidence was similar between composite and individual ITA grafts (5.7% versus 3.3%, p = 0.278) and composite and individual RA grafts (11.5% versus 29.6%, p = 0.297) in target vessels with severe stenosis. CONCLUSIONS The angiographic outcomes of composite grafts were closely related to the severity of stenosis of the target coronary artery. In target vessels with mild stenosis, composite grafting resulted in a higher incidence of graft occlusion or string sign than individual grafting did.

Radial Artery Graft for Coronary Artery Bypass Surgery: Biological Characteristics and Clinical Outcome

Abstract  The radial artery (RA) is gaining popularity as a bypass conduit for coronary artery bypass grafting, and its impact on clinical practice has been extensively explored. In the present article, we provide a review of postoperative hand circulation, vascular biological characteristics of the RA graft, the efficacy of vasodilator therapies, and mid‐term clinical results of use of the RA graft. Fundamental studies revealed excellent vascular biological characteristics of the RA graft as a living arterial conduit, making it almost equivalent to the internal thoracic artery (ITA) graft. Clinical studies have yielded encouraging mid‐term results. Most studies reported in favor of the RA graft over the saphenous vein graft with regard to patency rate, freedom from cardiac events, and survival. However, superiority of either the RA or right ITA graft has not been conclusively determined. The long‐term results of RA grafts remain unknown, but at present, supplementary use of an RA graft with a left ITA graft appears feasible for CABG.

Graft Selection and One-Year Patency Rates in Patients Undergoing Coronary Artery Bypass Grafting

BACKGROUND The aim of this study was to assess the angiographic patency rates of grafts used for coronary artery bypass surgery. METHODS We reviewed the records of 930 patients who underwent isolated coronary artery bypass grafting between September 2004 and June 2009. Of these patients, 95.1% underwent off-pump coronary artery bypass grafting. Early and 1-year angiographic patency rates of grafts were assessed. RESULTS Mean anastomoses per patient were 4.0 +/- 1.3. Operative mortality was 0.5%. Stroke occurred in 2.2% of patients, and 1.3% had mediastinitis. Early and 1-year patency rate of total grafts was 97.4% and 87.5%, respectively. One-year patency rate of the left internal thoracic artery, right internal thoracic artery, radial artery, gastroepiploic artery, and saphenous vein graft was 96.1%, 92.0%, 69.5%, 81.4%, and 82.6%, respectively. One-year patency rates of in situ and free right internal artery graft were not significantly different (p = 0.13). One-year patency rate of the radial artery was significantly worse than that of the free right internal thoracic artery graft (p < 0.01) and saphenous vein graft (p < 0.01). CONCLUSIONS Multiple coronary arterial revascularizations in various combinations of grafts were clinically safe and effective for isolated coronary artery bypass surgery. Bilateral internal thoracic artery grafting for the left coronary artery system was the most reliable strategy as shown by angiographic patency rates.

Mechanisms of Recurrent Regurgitation After Valve Repair for Prolapsed Mitral Valve Disease

BACKGROUND We assessed mitral valve (MV) function using serial echocardiography as an indicator of the durability of MV repair. The aim of this study was to analyze the mechanisms of recurrent regurgitation after MV repair for degenerative disease. METHODS From 1991 to 2007, 736 patients had valve repair for mitral regurgitation caused by leaflet prolapse: 346 patients had posterior and 390 had anterior leaflet prolapse. The mean age was 54.6±14.6 years, with 495 males. The durability and mechanisms of recurrent regurgitation were evaluated by the findings of echocardiography and reoperation. Follow-up and late echocardiography averaged 5.7±3.9 and 5.1±3.6 years, respectively. RESULTS Survival was 91.9%±1.5% at 10 years. Freedom from reoperation and moderate or severe regurgitation at 10 years were 91.2%±1.7% and 84.5%±2.1%, respectively. Reoperations were performed for recurrent regurgitation in 29 patients, hemolysis in 5, and endocarditis in 1. Based on the findings of reoperation, the mechanisms of repair failure were procedure related in 9 (25.7%), valve related in 25 (71.4%), and unknown in 1. Late echocardiography revealed none to trivial regurgitation in 511 patients, mild in 153, moderate in 26, and severe in 40. Anterior leaflet prolapse, preoperative atrial fibrillation, and no use of annuloplasty ring were independent predictors of recurrent regurgitation. The main causes of moderate or severe regurgitation were leaflet thickening in 34 patients, leaflet prolapse in 20, dehiscence in 10, and unknown in 2. CONCLUSIONS The main mechanism of recurrent regurgitation after MV repair is progressive degeneration that is characterized by leaflet thickening and prolapse, especially in patients with anterior leaflet prolapse.

Angiographic outcomes of right internal thoracic artery grafts in situ or as free grafts in coronary artery bypass grafting

OBJECTIVE We sought to compare early and 1-year angiographic results of various coronary artery bypass grafting configurations with the right internal thoracic artery in combination with the left internal thoracic artery. METHODS We reviewed the records of 705 patients who underwent bilateral internal thoracic artery grafting between September 2004 and November 2008. The right internal thoracic artery was used as an in situ graft in 547 patients and as a free graft in 158 patients. We compared operative and postoperative variables and early and 1-year angiographic patency rates of the right internal thoracic artery between the groups. RESULTS The operative mortality and incidence of postoperative complications were not significantly different between groups. The overall patency rates of the right internal thoracic artery were 98.8% at early angiography and 94.3% at 1-year postoperative follow-up. There were no significant differences in patency rate between in situ and free right internal thoracic artery grafts (98.6% vs 99.3% early and 95.3% vs 89.8% at 1 year). The best patency rate of the right internal thoracic artery was achieved with in situ grafting to the left anterior descending system (99.4% early and 98.5% at 1 year). CONCLUSIONS Patency rates of in situ and free right internal thoracic artery grafts were similar in early and 1-year angiographic studies. Among various configurations, the best patency of the right internal thoracic artery was obtained with in situ grafting to the left anterior descending coronary artery.

Long-Term Outcome of Mitral Valve Repair for Infective Endocarditis

BACKGROUND In patients with mitral endocarditis, reconstruction of the damaged mitral valve (MV) is still challenging, and its durability remains unknown. We evaluated the long-term outcomes of MV repair for mitral regurgitation (MR) in patients with infective endocarditis. METHODS From 1991 to 2006, 633 patients had MV repair for MR caused by leaflet prolapse: 78 had endocarditis (active in 14, healed in 64) and 555 had degenerative disease. Durability was assessed by reoperation and recurrent MR. RESULTS The overall hospital mortality rate was 1.0% (endocarditis 0% vs degenerative 1.1%; p = 0.99). The 10-year survival and freedom from reoperation were 91.1 +/- 1.6% and 92.2 +/- 1.7%, respectively, with no differences between endocarditis and degenerative disease. Older age, New York Heart Association class III or IV, impaired ventricular function, and no use of annuloplasty were independent predictors of all-cause death. Freedom from moderate or severe MR was 99.8 +/- 0.2% at 2 weeks, 91.9 +/- 1.5% at 5 years, and 83.3 +/- 2.3% at 10 years, for all patients and did not differ between groups at 10 years (p = 0.388). Anterior leaflet prolapse, preoperative atrial fibrillation, and no annuloplasty were independent predictors of recurrent MR. In endocarditis patients, recurrent MR was mainly caused by leaflet thickening and calcification, but not by recurrence of endocarditis. CONCLUSIONS MV repair for endocarditis is associated with low operative mortality and morbidity, and its long-term durability is comparable with that of repair for degenerative disease. This study suggests that a degenerative process causes late failure after MV repair for endocarditis.

Impact of Proximal Anastomosis Procedures on Stroke in Off-Pump Coronary Artery Bypass Grafting

Abstract  Background: There are many options for proximal anastomosis during off‐pump coronary artery bypass grafting (CABG), but the efficacies of these procedures have not been well clarified. Therefore, we examined the clinical impact of our strategy to modify the proximal anastomosis procedure for aortic atherosclerosis. Methods: We retrospectively reviewed 535 consecutive patients undergoing off‐pump CABG between 2004 and 2007. The patients were divided into three groups depending upon the type of proximal anastomosis procedure: 241 patients with normal or mild atherosclerosis underwent partial clamping (clamp group), 81 patients with moderate atherosclerosis underwent the procedure with Heartstring (Guidant Corporation, Santa Clara, CA, USA), 28 patients underwent with Enclose II (Novare Surgical Systems, Inc., Cupertino, CA, USA) (device group), and 185 patients underwent the procedure without clamping, including six with severe atherosclerosis (no‐touch group). Results: There were seven in‐hospital mortalities (1.3%) and five strokes (0.9%). There was no difference in the mortality rate (clamp, 1.2%; device, 1.8%; no‐touch, 1.1%; p = 0.42) or stroke rate (clamp, 0.8%; device, 2.8%; no‐touch, 0.5%; p = 0.09) among the three groups. Graft patency was similar regardless of the method (clamp, 94.7%; Heartstring, 96.7%; Enclosed II, 96.0%; p = 0.80). Conclusions: Our strategy to modify the proximal anastomosis procedure resulted in a low stroke rate. Aortic clamping could be performed safely in patients with normal or mild atherosclerotic aorta. In patients with moderate atherosclerosis, the result of an anastomotic device may need a further investigation.

Arterial graft deterioration one year after coronary artery bypass grafting

OBJECTIVE Some arterial grafts have progressive narrowing or occlusion during the first postoperative year despite angiographic patency in the immediate postoperative period. This study analyzed the incidence and predictors of arterial graft deterioration. METHODS We reviewed 778 distal anastomoses of arterial grafts in 243 patients who underwent off-pump coronary artery bypass grafting. All patients underwent both early and 1-year follow-up coronary angiography, with all arterial grafts patent on the early angiograms. Arterial graft deterioration was defined as diffuse graft stenosis or occlusion newly found at 1-year follow-up angiography. RESULTS Graft deterioration was present in 13.8% (string sign, 6.9%; occlusion, 6.8%) of distal anastomoses. The incidence of graft deterioration was higher among cases of non-internal thoracic arterial graft (27.7% vs 6.0%, P < .001), non-left anterior descending coronary arterial anastomosis (19.1% vs 2.0%, P < .001), mild (≤75%) stenosis of the target coronary artery (26.0% vs 7.6%, P < .001), composite grafting (19.9% vs 7.8%, P < .001), and multiple anastomoses from a single inflow source (19.5% vs 5.1%, P < .001). The incidence was particularly high when composite or multiple grafting from a single inflow source was performed to a target coronary artery with mild stenosis. Non-internal thoracic arterial graft, mild target stenosis, and multiple grafting from a single inflow source were independent predictors of graft deterioration. CONCLUSIONS Arterial graft deterioration was closely related to particular graft materials and designs.