It is essential to evaluate the quality of coronary artery bypass grafting (CABG) anastomosis in the operating room. Transit-time flow measurement has been increasingly used for this purpose, because it is less invasive, more reproducible, and less time consuming. The electrocardiogram-gated flow measurement has made it possible to identify the systolic flow (Qs) and diastolic flow (Qd) and to calculate a new index, diastolic filling index (DFI=100∫Qd/[∫|Qs|+∫|Qd|]) for graft flow analysis. In this study, we investigated the clinical significance of DFI, together with other indexes, including mean flow (Qm), pulsatility index (PI), % insufficiency (INSUF), and F0/H1, where F0 is a power of the fundamental frequency and H1 is a power of the first harmonic in spectral analysis by fast Fourier transformation of the flow curve. We examined the relationships of these intraoperative flow variables of the postoperative angiographic findings of 125 CABG grafts, including 58 in-situ internal thoracic arteries. There were significant differences between patent and non-patent grafts in all of the intraoperative flow parameters (Qm: 47.9±31.8ml/min vs 10.2±3.6ml/min, PI: 3.0±1.4 vs 9.6±2.4, INSUF: 3.3±4.2% vs 29.9±8.1%, F0/H1: 2.8±2.0 vs 0.6±0.2, DFI: 68.5±8.4% vs 38.2±17.2%). Our data suggested that a DFI value of more than 50% can be useful for surgeons to distinguish patent from non-patent grafts in the operating room, in combination with other parameters: Qm>15ml/min, PI<5, INSUF<15%, and F0/H1 ratio>1.0.

We describe our surgical experience of localized thoracoabdominal aneurysm in a 60-year-old woman with hypertension and hyperlipidemia. She was admitted for severe nausea associated with uremia. The initial CT scan revealed bilateral hydronephrosis, retroperitoneal fibrosis, inflammatory abdominal aneurysm, and localized thoracoabdominal aneurysm. To resolve the bilateral urinary tract obstruction, bilateral ureteral stents were inserted. After the renal function improved, the thoracoabdominal aneurysm was removed and replaced with an 18-mm woven-Dacron graft under partial cardiopulmonary bypass. The inflammation and fibrosis along the abdominal aorta did not extend to the thoracoabdominal aneurysm. Following the case presentation, we discussed the pathophysiologic aspects of this patient.

Diffuse hepatic arteriovenous malformation is extremery rare disease. A 69-year-old female was admitted to Nagoya Ekisaikai Hospital because of heart failure in NYHA class III. A selective celiac angiogram, echo cardiography and cardiac catheterization revealed high output cardiac failure secondary to diffuse hepatic areteriovenous malformations. Hepatic artery embolization with steel coils was performed. This resulted in amelioration of heart failure.

A 39-year-old woman was referred for assessment of abnormality of on a CT scan with a vascular anomaly of the aortic arch. This patient was completely asymptomatic with no concomitant pathologies and no reported prior trauma. Laboratory data for syphilitic or other microbial infections were negative. The diagnosis was confirmed by angiographic computed tomographic scan with 3-dimensional reconstruction. This technique documented the presence of the aneurysm and the left subclavian artery arising from the unique form of aneurysm. Early surgery was preferred because of the young age of the patient and the morphology and the size of the aneurysm (50 mm). Surgery was performed by a left postero-lateral thoracotomy through the forth intercostal space. Femoro-femoral partial cardiopulmonary bypass was used for distal perfusion. An aortic clamp was placed just distal to the left carotid artery, and a second clamp was placed in the descending thoracic aorta. The aortic isthmus was replaced with a 20-mm Dacron graft, and the left subclavian artery was reimplanted to the prosthesis with an 8-mm Dacron graft interposition. This aneurysm was the result of abnormal organogenesis of a primitive aortic arch and the remnant of the dorsal aorta, in other words, Kommerell's diverticulum. Microscopic examination demonstrated severe medial layer atrophy. In the light of the high risk of rupture, which was proved to be present by the very thin aneurysm wall at the time of surgery, we suggest early surgical treatment of idiopathic isthmus aneurysms in young patients regardless of aneurysm diameter.

Cardiovascular reoperations involve high-risk because of adhesions. We examined the strategies and clinical outcomes of the reoperations in our institute. From January 2003 to December 2008, 52 patients underwent reoperations, accounting for 4.5% of all adult patients. The duration from the previous surgery was 10.1±9.3 years. Reoperations were performed due to infection (n=10), after valve surgery (n=16), after coronary surgery (n=9), due to Marfan syndrome (n=3), after aortic surgery (n=7), after congenital surgery (n=4), and for other reasons. In the reoperations, the same surgical site was exposed in 65%, the femoral vessels were exposed before re-sternotomy in 77%, the inflow was on the ascending aorta in 35%, and cardiopulmonary bypass was initiated before re-sternotomy in 37%. Systemic cooling was needed in 4 patients and some maneuvers for patent internal thoracic artery grafts in 6 patients. The operation time of 9.6±2.5 h and the cardiopulmonary bypass time of 295±111 min, respectively. We experienced intraoperative injuries in 16 patients (31%). Platelet transfusion was needed in 90% and a second CPB in 15%. Postoperative complications included hemorrhage (14%), infection (13%), stroke (4%), respiratory failure (44%), and renal failure (1%). The hospital mortality was 7.7% (4/52) due to uncontrolled infection, liver failure, pulmonary hemorrhage, and left ventricular rapture. The 2-year survival rate was 83.1% with the mean follow-up of 24±18 months. In conclusion, although the risk of injuries at re-sternotomy was not high, limited surgical field due to adhesions resulted in fatal injuries and in the cardiac reoperations we experienced. We need to improve our strategies for further reduction in mortality and morbidities in reoperations.

A 60-year-old man with type 2 diabetes mellitus and severe obesity (height 170 cm, weight 160 kg, BMI 55) was admitted to our hospital because of acute inferior wall myocardial infarction due to acute thromboembolism of the right coronary artery (RCA). Because of three-vessel coronary diseases, we planned coronary artery bypass grafting after the medical therapy. The patient was intubated, then suffered congestive heart failure and pneumonia, and had a tracheotomy because of obesity hypoventilation syndrome. When his general condition improved after 14 months of medical therapy, we performed the operation. At that time, his weight had decreased to 107.5 kg, and BMI decreased to 37.2. We decided that tracheotomy was necessary to avoid respiratory complications. We chose a thoracoabdominal spiral incision for 2 reasons. Firstly we needed to avoid wound contamination by the tracheotomy stoma. Secondly we decided that the left internal thoracic artery (LITA) and the right gastroepiploic artery (RGEA) were sufficient for bypass grafts to the left anterior descending artery (LAD), the diagonal branches (D1), the posterolateral artery (PL) and the posterior descending artery (PD). Before the operation, epidural anesthesia was performed for postoperative analgesia to prevent respiratory dysfunction. In the right semi-lateral position at 30°, a 4th intercostal space thoracotomy was performed, and the LITA was harvested. The skin incision was extended to the midline of the abdomen and the RGEA was harvested. The end of the LITA was anastomosed with the free RGEA as I composite and the composite was anastomosed to the LAD, the D1, the 14 PL and the 4 PL without cardiopulmonary bypass. Without any perioperative blood transfusion, the patient was discharged with no perioperative complication, including mediastinitis. With this incision, we achieved secure prevention of wound contamination by the tracheotomy stoma, harvesting of a sufficient length of the LITA and RGEA and good visualization of the anastomotic sites with less cardiac displacement than median sternotomy.