Shunei Saito

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.

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.

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.

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.

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.

Mitral valve motion after performing an edge-to-edge repair in an isolated swine heart

OBJECTIVES Mitral valve motion after performing an edge-to-edge repair is a major concern, but it has not yet been observed directly. Mitral valve motion was assessed by using a high-speed digital video camera and microsonometric analysis in an isolated swine heart, and any changes in the mitral valve area or the development of mitral stenosis symptoms were evaluated. METHODS A temporary edge-to-edge repair model was created. The mitral valve motion was assessed by using a high-speed digital video camera, and the motion of the mitral annulus was measured by means of sonomicrometric analysis with or without performing edge-to-edge repair (n = 5). The left ventricular volumetric measurements were also measured with a conductance catheter. One cardiac cycle was divided into 4 phases: the mitral valve open phase, the isovolumic contraction phase, the aortic valve open phase, and the isovolumic relaxation phase. RESULTS The mitral valve was divided into 2 orifices by using the edge-to-edge technique, and the mitral valve area decreased by approximately 30%. The ratio of mitral valve open phase significantly decreased (31.9% +/- 3.4% vs 41.4% +/- 3.7%, P = .04). There were no significant differences in the diameter and the changes of anteroposterior dimensions of the mitral annulus. The stroke volume and the peak positive and negative dp/dt values showed no obvious change, but dv/dt values increased slightly without significance after removing the edge-to-edge suture (118 +/- 25 vs 130 +/- 17 mL/s, P = .14). CONCLUSIONS The mitral valve area decreased slightly; however, edge-to-edge repair did not create symptomatic mitral stenosis and showed no adverse affects on cardiac function.

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.

Movement of mitral fibrous components in an isolated porcine working heart model

Background There is little research regarding the movement of mitral fibrous components. We analyzed changes in mitral fibrous components in normal and deteriorated isolated working swine hearts. Methods In 5 swine hearts, 6 sonomicrometry transducers were placed around the mitral annulus and 2 in the papillary muscle tip. During the working cycle, we evaluated the annular dimension and calculated the contraction range and contraction ratio during the cardiac cycle in normal and deteriorated modes. Results The transverse (24.5 ± 2.3 vs. 27.4 ± 2.4 mm) and posterior longitudinal diameter (18.3 ± 7.0 vs. 22.5 ± 5.5 mm) increased significantly in deteriorated mode. The contraction range in transverse (1.8 ± 0.6 vs. 0.8 ± 0.7 mm) and posterior longitudinal (1.6 ± 0.6 vs. 0.8 ± 0.3 mm) diameters decreased significantly in deteriorated mode. The contraction range of the strut chordae was less than 1.0 mm in both modes, with no significant differences. The contraction ratio of the anterior strut chordae was significantly reduced in deteriorated mode (3.2 ± 1.1% vs. 2.2 ± 1.1%). The contraction ratio of the annulus was significantly lower in deteriorated mode with respect to transverse (6.9 ± 2.1% vs. 2.9 ± 2.9%) and longitudinal (13.3 ± 4.5% vs. 8.6 ± 5.1%) diameters. Conclusions In the deteriorated hearts, the mitral annulus was dilated and contractility decreased. The length of the strut chordae differed 1 mm between the deteriorated and normal modes; however, the contraction ratio of the anterior chordae during the cardiac cycle was reduced, indicating increased stretching.

Cannula for retrograde cardioplegia under direct vision.

We greatly appreciate the interest of Keshavamurthy and colleagues in our work. We also believe that our technique for the delivery of retrograde cardioplegia is very safe and effective. We are encouraged to receive this affirmative comment from surgeons working in a high-volume centre. The middle cardiac vein, which may drain blood from some parts of the right ventricle, opens into the coronary sinus very close to its ostium. Accordingly, it is important not to exclude the vein in protecting the right ventricle. The retrograde coronary sinus perfusion catheter that we use has a larger balloon than the one they use; therefore, we must continually maintain the placement of the catheter in the terminal position of the coronary sinus so that the inflated balloon remains in a partially intra-atrial position. Their ingenuity in using a small balloon, to improve the efficiency of the retrograde cardioplegia, is very reasonable. In Japan, a catheter with a flattened disk-shaped balloon has been developed. [1] Although our clinical outcomes using the open technique have been satisfactory so far, we may adopt the same specially designed catheters to ensure that none of the

Novel technique of retrograde cerebral perfusion for descending aortic repair: direct cannulation into left internal jugular vein

We performed descending thoracic aortic repair via posterolateral thoracotomy using retrograde cerebral perfusion with direct cannulation into the left internal jugular vein. No postoperative neurological dysfunction was observed. This patient was discharged without any adverse events.