Ken Miyahara

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.

The effects of using a leukocyte removal filter during cold blood cardioplegia

During myocardial ischemia, neutrophils and platelets exert negative effects on the myocardium. In this study, we used a leukocyte removal filter during cardioplegia, and investigated its effect on myocardial damage during reperfusion by measuring the plasma levels of granulocyte components, platelet components, and cardiac enzymes [creatinine phosphokinase (CK) and creatinine phosphokinase myocardial band (CK-MB)] in 24 patients who underwent cardiopulmonary bypass. The patients were divided into two groups of 12 according to whether or not a filter was placed in the cardioplegic route. Blood samples were drawn directly from the coronary sinus before aortic cross clamping, and at 1, 5, and 15 min after declamping. Group F, which had the filter, showed better cardiac enzyme and lipid peroxidation results than group N, which did not. The results of this study suggest that the application of a filter during cold blood cardioplegia may reduce myocardial damage.

A new device for exposing the circumflex coronary artery

We have devised a new retractor for use in coronary artery bypass grafting that is made from three woven Teflon tapes. This method allows sufficient counterclockwise rotation of the heart, provides excellent exposure of the posterior and inferior coronary artery systems, and creates a horizontal surgical plane for the circumflex anastomosis.

Cardiovascular surgery in patients on chronic dialysis: effect of intraoperative hemodialysis

To evaluate the operative result and the perioperative management of dialysis patients undergoing elective cardiac surgery, we retrospectively reviewed consecutive adult patients with chronic renal failure dependent on maintenance dialysis. Between April 1994 and March 2002, 20 patients who underwent cardiopulmonary bypass (CPB) procedures were studied. Fourteen patients underwent isolated coronary artery bypass grafting, four valve replacements and two combined procedures. Our strategy for the chronic dialysis patients was as follows: dialysis the day before the operation, intraoperative hemodialysis (HD) during CPB, and no dialysis or hemofiltration (HF) on the operative day. Intraoperative HD produces the optimal fluid and electrolyte balance at the end of the operation. The mean interval between the end of surgery and the commencement of HD was 31.2+/-12.5 h. No patients required any hemocatharsis such as HF or HD on the day of operation. The overall operative mortality was 5.0%. There were six late deaths (30.0%). Overall, including the operative and non-cardiac death, actuarial survival rate was 85.0% at 1 year, 70.0% at 5 years, and 65.0% at 6 years. Intraoperative HD has an advantage in the postoperative period; it avoids the hemodynamic instability and the risk of heparin-associated bleeding associated with the use of HD.

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.

Successful repair of tricuspid regurgitation 46 years after causal blunt trauma.

Tricuspid regurgitation arising from chest trauma 46 years earlier was successfully corrected by valve reconstruction in a 67-year-old man. As the merits of valve repair are well established, it can be advocated for traumatic tricuspid regurgitation, regardless of the time from the causal injury.

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.

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.

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.