Long-term Outcome 10 Years After Free Gastroepiploic Artery Graft for Coronary Artery Bypass Surgery.

BACKGROUND: The long-term benefits of "free" gastroepiploic artery (GEA) grafts remain unclear. The aim of this study is to investigate the long-term patency and clinical results of en bloc free GEA grafts. METHODS: Of the 1478 patients undergoing coronary artery bypass graft surgery at our institution between January 1997 and December 2009, 137 patients underwent en bloc free GEA grafting. Graft patency, late survival, and freedom from major adverse cardiovascular events were examined. Propensity score matching was used to compare the patency of free GEA grafts with the saphenous vein grafts, and 134 matched pairs were generated. RESULTS: The early patency rate of free GEA grafts was 98.6%. The long-term patency rates of the free GEA grafts was 96.5% at 5 years, 95% at 10 years, and 86.6% at 15 years. In the 134 matched pairs, the long-term patency rates of free GEA grafts anastomosed to the right coronary artery were significantly higher than those of saphenous vein grafts to the right coronary artery (97% vs 91.8% at 5 years; 95.3% vs 79.6% at 10 years; 85.9% vs 61.7% at 15 years; P < .001). Survival was 94% at 5 years, 86.6% at 10 years, and 66.8% at 15 years; and freedom from major adverse cardiovascular events was 93.2% at 5 years, 91.3% at 10 years, and 73.1% at 15 years. CONCLUSIONS: En bloc free GEA grafts had favorable long-term performance and can be considered as an effective option for patients who need to receive as many arterial grafts as possible.

A modified technique for supra-annular implantation of prosthetic tricuspid valve.

In conventional tricuspid valve replacement, there is a risk of valve detachment because stitches are placed on relatively fragile tissues. In the supra-annular implantation technique, stitches are placed lateral to the triangle of Koch and the coronary sinus instead of the anterior and septal leaflets as in conventional tricuspid valve replacement. This procedure relieves stress at the antero-septal commissural area, as well as avoids injury to the conduction system. However, there are a few drawbacks: (1) the valve sits obliquely at the annular surface, (2) the suture line becomes extremely long, and (3) the venous return to the coronary sinus may be impeded. We modified the suture line, which travels lateral to the triangle of Koch and medial to the coronary sinus, to solve these problems. We herein report the technique and results of four cases.

Routine presternotomy extracorporeal circulation for redo surgery.

To reduce the risk of adverse events, presternotomy extracorporeal circulation (ECC) is routinely performed at our institution for patients who require resternotomy. We report our 10-year experience of performing presternotomy ECC for cardiac reoperation and the clinical results. Fifty-seven consecutive cardiac reoperations involving resternotomy were performed between January 2006 and December 2015. ECC was established prior to median sternotomy in all patients. Two patients sustained injury to the right ventricle during sternotomy. Eleven patients sustained injury to the mediastinal structures during dissection (right atrium in 3; superior vena cava in 2; inferior vena cava in 3; left internal thoracic artery in 1; and saphenous vein graft in 2 patients). Longer ECC time and greater transfusion volume were necessary. Two patients (3.5%) died within 30 days of operation. Perioperative morbidity included reexploration for bleeding in 4 (7.0%), stroke in 1 (1.8%), acute renal failure that required hemodialysis in 5 (8.8%), sepsis in 5 patients (8.8%), prolonged ventilation in 9 (15.8%) and tracheostomy in 5 (8.8%). Routine establishment of presternotomy ECC reduces the risk of injury to the mediastinal structures during reentry and facilitates easier repair in the event of structural injury during reentry or dissection. However, longer ECC time and significantly greater transfusion volume requires attention.

Saphenous Vein Graft Aneurysm Repaired with Radial Artery Graft Pre-Sewn Vascular Prosthesis Patch.

Saphenous vein graft aneurysms are rare but are potentially fatal and their optimal management is not clearly established. Herein, we report a case of a saphenous vein graft aneurysm that was successfully treated with surgical intervention, including aneurysmal resection and re-grafting. The aneurysm, detected 36 years after coronary artery bypass grafting, was located at the proximal part of the saphenous vein graft to the posterolateral branch; the flow of the left anterior descending coronary artery was limited due to compression of the left internal thoracic artery by the adjacent aneurysm. The proximal anastomotic site was reconstructed under deep hypothermic circulatory arrest using a radial artery graft pre-sewn vascular prosthesis patch.

Implementation of bundled interventions greatly decreases deep sternal wound infection following cardiovascular surgery.

OBJECTIVE: Surgical site infection (SSI), particularly deep sternal wound infection (DSWI), is a serious complication after cardiovascular surgery because of its high mortality rate. We evaluated the effectiveness of an SSI bundle to reduce DSWI and identify the risk factors for DSWI. METHODS: During the period January 2004 to February 2012, 1374 consecutive patients undergoing cardiovascular surgery via sternotomy were included. The cohort was separated into periods from January 2004 through February 2007 (period I, 682 patients) and March 2007 through February 2012 (period II, 692 patients). During period II, all preventive measures for DSWI were completed as an SSI bundle. We compared the DSWI rate between the 2 periods. Univariate and multivariate analyses were performed for the entire period to identify the risk factors for DSWI. RESULTS: DSWI occurred in 13 patients (1.9%) during period I and in 1 patient (0.14%) during period II. The DSWI rate during period II was significantly decreased by 93%, compared with period I (P=.001). Independent risk factors for DSWI included obesity (odds ratio [OR], 3.4; 95% confidence interval [CI], 1.00-11.75; P=.049), the use of 4 sternal wires (OR, 8.2; 95% CI, 1.39-48.14; P=.020), long operative time (OR, 4.4; 95% CI, 1.20-16.23; P=.026), and postoperative renal failure (OR, 9.0; 95% CI, 2.44-33.30; P=.001). CONCLUSIONS: Complete implementation of simple multidisciplinary prevention measures as a bundle can greatly decrease the incidence of DSWI.

Retrograde cardioplegia revisited: open technique for long aortic cross clamping.

BACKGROUND: The efficacy of retrograde cardioplegia for myocardial protection is still controversial. In our institution, we exclusively use intermittent administration of tepid, undiluted blood supplemented with potassium and magnesium for the cases with aortic insufficiency, requiring aortotomy, or undergoing mitral valve repair. In using this retrograde technique, we make a point of cannulating a retrograde perfusion catheter under direct vision following right atriotomy. The purpose of this retrospective study is to evaluate the clinical outcome of using this technique. METHODS: This study comprises 49 patients who underwent elective valve surgery using direct-vision retrograde cardioplegia exclusively, requiring more than 3h aortic cross-clamping. Their clinical outcome was reviewed retrospectively. RESULTS: There was no hospital mortality in this study. No patient was noted to have evidence of mediastinitis, myocardial infarction, or cerebral complications in the postoperative period. The case requiring the longest aortic cross-clamping time (380 min) survived the operation without the use of intra-aortic balloon pumping or percutaneous cardiopulmonary support, and the postoperative course was uneventful. CONCLUSIONS: Our result suggests that direct-vision retrograde cardioplegia is a safe and effective method of cardioplegia delivery, and provides a longer period of myocardial protection than previously thought.

[Severe coronary artery spasm immediately after aortic valve replacement].

We report a case of 72-year-old man with severe manifestations of coronary artery spasm immediately after aortic valve replacement (AVR), which was associated with hemodynamic and arrhythmic instability. The AVR was performed under mild hypothermic cardiopulmonary bypass (34 degrees C), and retrograde blood cardioplegia was intermittently delivered at the same temperature. Immediately after the operation, the patient suddenly developed severe bradycardia and hypotension, and repeated ventricular fibrillation. Percutaneous cardiopulmonary support system (PCPS) and intra-aortic balloon pumping (IABP) were required for this circulatory collapse. Echocardiography revealed left ventricular segmental dysfunction, and coronary artery bypass grafting (CABG) to the right coronary artery and the left ascending artery was performed [during CABG, coronary spasm was strongly suspected by repetitive ST elevation and depression on electrocardiogram (ECG) monitor]. Eventually, the spasm subsided with the intravenous infusion of nitrates, nicorandil, and diltiazem. The remaining postoperative course was uneventful and the patient was discharged on the 24th postoperative day in good clinical condition.

Infected aortic aneurysm, purulent pericarditis, and pulmonary trunk rupture caused by methicillin-resistant Staphylococcus aureus.

A 66-year-old woman presented with cardiac tamponade. Pericardiocentesis revealed purulent pericarditis. Enhanced computed tomography showed a saccular aneurysm of the aortic arch. An irregularly shaped and partially enhanced mass was seen adjacent to the aneurysm, which suggested development of a mycotic pseudoaneurysm. Surgical drainage was performed through a subxiphoid incision, and continuous irrigation was commenced. On the following day, however, massive bleeding was recognized through the drains. The patient was immediately transferred to the operating theater, and extracorporeal circulation was established. A perforation 1 cm in diameter was found on the anterior surface of the pulmonary trunk, and a large amount of pus came out from the tear. The ascending aorta and the arch were found to be infected. Surgical repair was impossible due to extensive infection, and the patient died. Methicillin-resistant Staphylococcus aureus was isolated from the pericardial effusion, blood, and intraluminal thrombus of the aortic aneurysm.

Traumatic ventricular septal defect following a stab wound to the chest.

A 51-year-old man who had been suffering from depression stabbed himself in the chest with an ice pick. At presentation, an ice pick lodged in the left fifth intercostal space was moving synchronously with his heartbeat. Echocardiography revealed that the tip was penetrating the anterior wall of the right ventricle. Because the patient was tamponading, an emergency operation was carried out. The ice pick was removed following the establishment of a cardiopulmonary bypass and pericardiotomy. The perforation of the right ventricle was closed with a pledget-reinforced mattress stitch. On postoperative day 12, a holosystolic murmur was detected on auscultation. Transthoracic echocardiography revealed a ventricular septal defect 5 mm in diameter located near the apex. The pulmonary-tosystemic flow ratio was 1.1 by echocardiographic measurement. No sign of heart failure was present. Although it was agreed to manage the ventricular septal defect conservatively, careful echocardiographic follow-up is mandatory.

On-pump beating-heart coronary artery bypass grafting after acute myocardial infarction has lower mortality and morbidity.

OBJECTIVE: The mortality of conventional coronary artery bypass grafting after acute myocardial infarction remains high. This study compared the clinical outcomes of patients undergoing conventional and on-pump beating-heart coronary artery bypass grafting and evaluated the efficacy of an on-pump beating-heart technique for the surgical treatment of these critically ill patients. METHODS: Between January 1999 and March 2005, 61 patients underwent emergency coronary artery bypass grafting for acute myocardial infarction. In the first 23 patients, the conventional cardioplegic method was performed. In the most recent 38 patients, the on-pump beating-heart procedure was used without cardioplegic arrest. RESULTS: A significant reduction occurred in the observed mortality between the conventional and on-pump beating groups (21.7% vs 2.6%, P = .04), despite a higher predicted mortality risk calculated by using EuroSCORE (9.0 +/- 1.6 vs 9.6 +/- 1.6, P = .048) and a greater use of a preoperative intra-aortic balloon pump (43.5% vs 78.9%, P = .005). On-pump beating-heart patients received fewer bypass grafts than conventional patients (2.0 vs 2.9, P = .001), but the internal thoracic artery was used more often in on-pump beating-heart patients (P = .014). Three patients in the conventional coronary artery bypass grafting group required new insertion of an intra-aortic balloon pump, whereas no patients required this in the on-pump beating-heart group (P = .220). Postoperative renal failure requiring hemodialysis occurred in 2 patients in the conventional coronary artery bypass grafting group but in no patients in the on-pump beating-heart group (P = .138). CONCLUSIONS: On-pump beating-heart coronary artery bypass grafting is the preferred method of emergency myocardial revascularization for patients with acute myocardial infarction who might tolerate cardioplegic arrest poorly. It has lower postoperative mortality and morbidity than conventional coronary artery bypass grafting.

Transplantation of the free gastroepiploic artery graft for myocardial revascularization: long-term clinical and angiographic results.

BACKGROUND: Use of the free gastroepiploic artery (GEA) graft for coronary revascularization is not very popular because of its tendency to vasospasm. We hypothesize that the cause of free GEA spasm is graft damage caused by an interruption of venous drainage from the graft. To overcome this problem, we anastomosed the accompanied gastroepiploic vein to the right atrial appendage simultaneously with the GEA grafting in the aortocoronary position. We here assess the clinical result and the angiographic patency of the free GEA graft in our method in the late postoperative period. METHODS: Between January 1997 and April 2001, 57 patients underwent coronary artery grafting with a free GEA using our method. A total of 169 distal anastomoses (average 2.96) were constructed. The free GEA grafts were anastomosed to the main right coronary artery in 26 patients, right coronary artery branch in 27, left anterior descending artery in 1 patient, high lateral branch in 2 patients, and circumflex branch in 2. The mean clinical follow-up is 77 months (range, 35 to 110) in 57 cases, and the angiographic follow-up averages 77 months (range, 37 to 110) in 46 cases. RESULTS: There was no cardiac death, and all patients were in Canadian Cardiovascular Society class II or less. The mean 77-month patency rate of the free GEA in our method was 95.7%. The patency rates of internal thoracic artery, radial artery, and saphenous vein graft in the same period were respectively 93.2%, 100%, and 81.3%. CONCLUSIONS: Free GEA grafting with venous drainage for myocardial revascularization provided excellent long-term performance.

Spontaneous restoration of patency in the free gastroepiploic artery graft: the living transplanted vascular system for coronary revascularization.

We report an incidence of coronary revascularization with the gastroepiploic artery in which angiography demonstrated patency at 1 month, severe narrowing at 1 year, and restoration of patency associated with progression of proximal coronary disease at 8 years. This report documents the reversibility of the free gastroepiploic artery.

[New method for preparing proximal anastomotic system].

Heartstring is a useful device. However, the device failure at the time of loading the seal into the delivery device is a troublesome issue. To avoid this problem, we invent a new method using 2 tourniquets made of 5 mm-wide woven Teflon tapes and plastic tubes. Using our method, the loading procedure became easier and more reliable.

Pathophysiological significance of T-type Ca2+ channels: expression of T-type Ca2+ channels in fetal and diseased heart.

Re-expression of fetal genes has been considered to underlie ionic remodeling in diseased heart. T-type Ca(2+) channels have been reported to be functionally expressed in embryonic hearts. In this review, we summarize developmental changes of T-type Ca(2+) channels in mouse ventricles from 9.5 days postcoitum (dpc) to adulthood, using patch clamp and quantitative PCR. In addition, we introduced T-type Ca(2+) channel expression in hypertrophied ventricles caused by myocardial infarction (MI) and aortic banding (AOB). Substantial T-type Ca(2+) channel current was recorded at both 9.5 and 18 dpc. The currents were inhibited by Ni(2+) at low concentrations. The current was not detectable in the adult stage. Ca(v)3.2 (alpha(1H)) mRNA is expressed dominantly at both 9.5 and 18 dpc. Ca(v)3.1 (alpha(1G)) increases from 9.5 to 18 dpc, but remains at low level compared with Ca(v)3.2. In contrast, Ca(v)3.1 is greater than Ca(v)3.2 at the adult stage. In MI, Ca(v)3.1 mRNA correlates negatively with brain natriuretic peptide (BNP) mRNA, whereas Ca(v)3.2 mRNA correlates positively with BNP mRNA. In AOB, these correlations are weak. We also analyzed the neuron-restrictive silencer factor (NRSF) in these hearts because it is the suppressor of transcription of the fetal cardiac gene program. The negative correlation between NRSF and BNP was stronger in MI than in AOB. Our findings show that Ca(v)3.2 underlies the functional T-type Ca(2+) channel in embryonic heart and suggest that NRSF may regulate Ca(v)3.2 expression in diseased hearts.

Subtype switching of L-Type Ca 2+ channel from Cav1.3 to Cav1.2 in embryonic murine ventricle.

BACKGROUND: Embryonic hearts exhibit spontaneous electrical activity, which depends on Ca2+ influx through L-type Ca2+ channels. In this study the expression of the L-type Ca2+ channel alpha1 subunit gene in the developing mouse heart was investigated. METHODS AND RESULTS: Mouse cardiac ventricles 9.5 days post coitum (dpc), 18 dpc and adult were used. At 9.5 dpc the level of Cav1.3 mRNA was higher than that of Cav1.2 mRNA. With development, Cav1.2 mRNA increased and Cav1.3 mRNA decreased. Analysis of Cav1.3 splicing variants showed that Cav1.3(1b) mRNA was expressed at a higher density than Cav1.3(1a) mRNA. Cav1.3 protein was detected only at 9.5 dpc, whereas Cav1.2 protein was expressed from 9.5 dpc and its expression increased with development. L-type Ca2+ currents were prominent at 9.5 dpc. The Ca2+ current amplitude at 9.5 dpc was comparable to that at 18 dpc, and was larger in adults than at the embryonic stage. L-type Ca2+ current at 9.5 dpc was activated and/or inactivated at more negative membrane potentials than at 18 dpc or adult. L-type Ca2+ channels at 9.5 dpc were less sensitive to inhibition by nisoldipine than at adult. CONCLUSIONS: The Cav1.3 channel is functionally expressed in early embryonic mouse ventricular myocytes and potentially underlies ventricular automaticity.

Cav3.2 subunit underlies the functional T-type Ca2+ channel in murine hearts during the embryonic period.

T-type Ca2+ channels are implicated in cardiac automaticity, cell growth, and cardiovascular remodeling. Two voltage-gated Ca2+ subtypes (Ca(v)3.1 and Ca(v)3.2) have been cloned for the pore-forming alpha(1)-subunit of the T-type Ca2+ channel in cardiac muscle, but their differential roles remain to be clarified. The aim of this study was to elucidate the relative contribution of the two subtypes in the normal development of mouse hearts. A whole cell patch clamp was used to record ionic currents from ventricular myocytes isolated from mice of early (E9.5) and late embryonic days (E18) and from adult 10-wk-old mice. Large T-type Ca2+ current (I(Ca,T)) was observed at both E9.5 and E18, displaying similar voltage-dependence and kinetics of activation and inactivation. The current was inhibited by Ni2+ at relatively low concentrations (IC(50) 26-31 microM). I(Ca,T) was undetectable in adult myocytes. Quantitative PCR analysis revealed that Ca(v)3.2 mRNA is the predominant subtype encoding T-type Ca2+ channels at both E9.5 and E18. Ca(v)3.1 mRNA increased from E9.5 to E18, but remained low compared with Ca(v)3.2 mRNA during the whole embryonic period. In the adulthood, in contrast, Ca(v)3.1 mRNA is greater than Ca(v)3.2 mRNA. These results indicate that Ca(v)3.2 underlies the functional T-type Ca2+ channels in the embryonic murine heart, and there is a subtype switching of transcripts from Ca(v)3.2 to Ca(v)3.1 in the perinatal period.

Ionic mechanisms of acquired QT prolongation and torsades de pointes in rabbits with chronic complete atrioventricular block.

BACKGROUND: The ionic basis of acquired QT prolongation and torsade de pointes (TdP) unrelated to drugs is not fully understood. METHODS AND RESULTS: We created a rabbit model with chronic complete atrioventricular block (AVB) (n=34), which showed prominent QT prolongation (by 120%), high incidence of spontaneous TdP (71%), and cardiac hypertrophy. Patch-clamp experiments were performed in left ventricular myocytes from 9 rabbits (8 with TdP, 1 without TdP) at approximately 21 days of AVB and from 8 sham-operated controls with sinus rhythm. Action potential duration was prolonged in AVB myocytes compared with control (+61% at 0.5 Hz, +21% at 3 Hz). Both rapidly and slowly activating components of the delayed rectifier K(+) current (I(Kr) and I(Ks)) in AVB myocytes were significantly smaller than in control by 50% and 55%, respectively. There was no significant difference in Ca(2+)-independent transient outward current (I(to1)). L-type Ca(2+) current (I(Ca,L)) in control and AVB myocytes was similar in peak amplitude, but the half voltage for activation was shifted to the negative direction (5.9 mV) in AVB myocytes. Voltage dependence of I(Ca,L) inactivation was not different in control and AVB myocytes. The inward rectifier K(+) current (I(K1)) significantly increased in AVB myocytes compared with control. CONCLUSIONS: In the rabbit, chronic AVB leads to prominent QT prolongation and high incidence of spontaneous TdP. Downregulation of both I(Kr) and I(Ks) in association with altered I(Ca,L) activation kinetics may underlie the arrhythmogenic ventricular remodeling.

Optimal size of prostheses for functioning of the aortic prosthetic valve in aortic and mitral valve replacement with annular enlargement through Manouguian's technique.

There is not yet agreement about the optimal size of the prostheses in aortic and mitral valve replacement with Manouguian's technique. In this technique, the aortic prosthetic valve can be pushed upon the mitral prosthesis which may cause dysfunction of the aortic prosthetic valve. The aim of this study was to clarify the size of the prostheses needed to avoid dysfunction of the aortic prosthetic valve. Three patients underwent aortic and mitral valve replacement through this procedure. Two of them had active aortic and mitral valve endocarditis. Aortomitral continuity involved with abscesses could be approached and completely excised using this technique. All patients survived the operation, but 1 of them suffered aortic mechanical valve dysfunction for the reason stated. Anatomical analysis of the geometrical relation of the 2 prosthetic valves suggests that the mitral annulus should be enlarged less than 25 mm to avoid dysfunction of the aortic prosthetic valve.