Ikutaro Kigawa

Comparison of durability of bioprostheses in tricuspid and mitral positions.

BACKGROUND Few reports have assessed differences in the durability of mitral and tricuspid bioprostheses after simultaneous implantation of the same bioprosthesis in both positions. We investigated the long-term outcome after simultaneous mitral valve replacement (MVR) and tricuspid valve supraannular implantation (TVSI) with the Carpentier-Edwards bioprostheses in patients with severe tricuspid regurgitation and advanced mitral valve disease. METHODS Between 1982 and 1998, 37 patients in our hospital underwent MVR and TVSI with Carpentier-Edwards bioprostheses. The mean age of the patients was 55+/-11 years. The average postoperative follow-up was 7.9+/-4.5 years after surgery (range 0 to 14.6 years, 315.1 patient-years). The follow-up rate was 100%. We evaluated the actuarial survival rate, the actuarial freedom from structural valve deterioration (SVD) and reoperation, and postoperative complications. RESULTS The overall actuarial survival rate at 13 years after the operation was 69%+/-31%. The actuarial freedom from SVD and reoperation in the mitral and tricuspid positions were 78+/-22 and 100% and 70+/-30 and 90%+/-10% (p = 0.03), respectively. No patient had systemic or pulmonary thromboembolism, or complications associated with fatal arrhythmia. CONCLUSIONS These results suggest that the bioprostheses in the tricuspid position yield significantly better long-term results than those in the mitral position after simultaneous MVR and TVSI.

Coronary artery reoperation through the left thoracotomy with hypothermic circulatory arrest

BACKGROUND The left thoracotomy approach to avoid injury of the patent old graft and the myocardium with mid sternal reentry at coronary artery reoperation. METHODS The left thoracotomy approach was used in 13 patients. There were 11 men and 2 women with a mean age of 63 years, ranging from 39 to 75 years. Three patients were having their third coronary bypass operation. In 11 patients, distal anastomoses were performed under circulatory arrest with moderate hypothermia. In the other 2 patients, distal anastomoses were performed on a beating heart. No aortic cross-clamp was applied in all patients. The mean number of distal anastomoses was 1.8; the grafted vessels were 11 anterior descending, 3 diagonal, 8 circumflex, and 1 posterolateral coronary arteries. Used grafts were 17 saphenous veins, 4 left internal thoracic arteries, and 2 gastroepiploic arteries. Inflow sites of the free graft were descending aorta in 10 patients and left subclavian artery in 3 patients. RESULTS All patients were alive and well at the mean follow-up of 16 months, and all grafts were patent. CONCLUSIONS The left thoracotomy approach is safe and effective for reoperation on the left coronary artery system, and circulatory arrest is convenient and safe for performing distal anastomosis.

Tricuspid valve supra-annular implantation in adult patients with Ebstein's anomaly

BACKGROUND Tricuspid valve supra-annular implantation (TVSI) has been performed for adult patients with Ebsteins anomaly at our hospital for several decades. TVSI is characterized by reliable reduction of tricuspid annulus size without affecting the conduction system; by prevention of residual tricuspid regurgitation (RTR) through preservation of the native tricuspid valve; and by implantation of the bioprosthesis at a supra-annular site. METHODS Ten adult patients with Ebsteins anomaly underwent TVSI. The right ventricular diameter and residual tricuspid regurgitation were evaluated by echocardiography preoperatively, at discharge, 1 year after the operation, and over the long term (12.4 +/- 5.5 years). Actuarial survival rate, actuarial freedom from structural valve deterioration rate, and postoperative occurrence of arrhythmia were also evaluated. RESULTS The actuarial survival rate at 19 years was 76 +/- 15%. Tricuspid regurgitation disappeared in 8 patients just after operation. Right ventricular diameter was significantly smaller at discharge than preoperatively (63 +/- 11 vs 37 +/- 9, p < 0.01), and there were no significant differences between values at discharge and at follow-up. The actuarial freedom from structural valve deterioration rate and the reoperation rate were both 100%. There were no fatal complications related to arrhythmia or thromboembolism. CONCLUSIONS TVSI is useful for adult patients with Ebsteins anomaly. The absence of complications related to fatal arrhythmia and thromboembolism, good durability of the bioprosthesis, and a simple operative procedure are merits of this therapy.

Arteriovenous access closure in hemodialysis patients with refractory heart failure: a single center experience.

Arteriovenous dialysis access may impose a burden on the cardiac system. The objective of this study is to examine the usefulness of access closure in hemodialysis patients with refractory heart failure and to identify possible factors associated with symptomatic improvements. The study population comprised 33 hemodialysis patients with symptomatic heart failure (New York Heart Association [NYHA] class ≥II), who underwent arteriovenous access closure (30 fistulas and three grafts) between 1991 and 2008. In all patients, heart failure was refractory to all possible medical and surgical treatments, and persisted after optimal dry weight control. First, short‐term changes in hemodynamics, clinical symptoms and echocardiographic morphology were examined. Second, clinical and echocardiographic parameters were compared between responders (N = 23), who demonstrated NYHA class improvement after access closure, and non‐responders (N = 10). After access closure, systolic blood pressure rose and the heart rate decreased significantly. Body weight and echocardiographic parameters did not change significantly. Twenty‐three patients (70%) demonstrated NYHA class improvement and were designated as responders. In responders, the duration from access creation to closure was significantly shorter and fewer had ischemic heart disease, compared with non‐responders. Access flow, cardiac output and ejection fraction were comparable between the two groups. Although the five‐year survival was 20.2% in all patients, responders showed better early survival than non‐responders. Arteriovenous access closure improved clinical symptoms in 70% of patients with refractory heart failure. This improvement was especially likely to be achieved in patients without ischemic heart disease and those who developed heart failure within a relatively short time after access creation.

Rapid diagnosis and management of intraoperative myocardial infarction during valvular surgery: using intraoperative transesophageal echocardiography followed by emergency coronary artery bypass grafting without coronary angiography.

A 68‐year‐old man was admitted to undergo elective mitral valve surgery. Although the preoperative coronary angiography was normal, the patient suffered a myocardial infarction that resulted in untreatable collapsed hemodynamics. After inferring the responsible occluded coronary artery from the segmental wall motion abnormality detected in intraoperative transesophageal echocardiography, together with the anatomy found in preoperative coronary angiography, we performed an emergency coronary artery bypass graft surgery without a new angiography. This procedure resulted in survival of a potentially life‐threatening situation. In selected cases, this therapeutic strategy may lead to reduction of mortality as a result of the intraoperative myocardial infarction. (ECHOCARDIOGRAPHY, Volume 22, November 2005)

LIMITATION OF IMPLANTATION OF ENDOVASCULAR STENT-GRAFT: CASE REPORT OF A PATIENT WITH THORACOABDOMINAL ANEURYSM

graft prostheses has offered a largely successful alternative approach to the treatment of thoracic aortic aneurysm, an approach that is less invasive and carries a lower risk than does the standard operative method.1,2 However, cardiac surgeons who use the new method have not fully determined optimum indications for applying this alternative to open repair. We report on the autopsy of a patient with reruptured thoracoabdominal aneurysm after endovascular stent-grafting 6 months previously. Clinical summary. A 76-year-old man was admitted to our hospital with a diagnosis of thoracoabdominal aneurysm. He had undergone distal gastrectomy, a low anterior resection for early-stage gastric and sigmoid colon cancer, and radical neck resection for a soft-palate cancer. His height was 152 cm and his body weight was 39 kg. He had significant psychroesthesia in all 4 limbs and anterior chest pain. A large thoracoabdominal aneurysm, 10.0 × 6.7 cm in diameter, extended to just above the celiac artery. For the prevention of impending rupture, we decided that implantation of an endovascular stent-graft, rather than the usual thoracotomy and graft replacement, was indicated because of the patient’s poor general conditions. The dimensions of the stent-graft were determined by his preoperative computed tomographic and angiographic evaluations. The stent-graft, covered by 32 × 190-mm thin-walled woven polyester, was 34 mm in diameter and 200 mm long. Spinal fluid was drained through a catheter placed in the lumbar space before the operation to ensure spinal cord protection. The endovascular stent-graft was implanted into the descending thoracic aorta from the right femoral artery. Although we attempted to place and fix the distal edge of the stent-graft just above the celiac artery, it moved to the cranial side of the aorta. Because of perigraft leakage seen at the distal edge of the stent-graft on intraoperative angiogram, a second implantation was attempted. The second stent-graft, 35 ×

Repeated mitral valve replacement in a patient with extensive annular calcification

BackgroundMitral valve replacement in the presence of severe annular calcification is a technical challenge.Case reportA 47-year-old lady who had undergone mitral and aortic valve replacement for rheumatic disease 27 years before presented with dyspnea. At reoperation, extensive mitral annular calcification was hindering the disc motion of the Starr-Edwards mitral prosthesis. The old prosthesis was removed and a St Jude Medical mechanical valve was implanted after thorough annular debridement. Postoperatively the patient developed paravalvular leak and hemolytic anemia, subsequently undergoing reoperation three days later. The mitral valve was replaced with an Edwards MIRA valve, with a bulkier sewing cuff, after more aggressive annular debridement. Although initially there was no paravalvular leak, it recurred five days later. The patient also developed a small cerebral hemorrhage. As the paravalvular leak and hemolytic anemia gradually worsened, the patient underwent reoperation 14 days later. A Carpentier-Edwards bioprosthetic valve with equine pericardial patches, one to cover the debrided calcified annulus, another as a collar around the prosthesis, was used to eliminate paravalvular leak. At 7 years postoperatively the patient is doing well without any evidence of paravalvular leak or structural valve deterioration.ConclusionMitral valve replacement using a bioprosthesis with equine pericardial patches was useful to overcome recurrent paravalvular leak due to severe mitral annular calcification.

Papillary Fibroelastoma of the Left Ventricle: Report of Two Cases

Papillary fibroelastoma is a relatively rare cardiac tumor. We report two cases of papillary fibroelastoma. The first case involved a 45-year-old woman who presented with rheumatic valves and three tumors developing from the papillary muscle and left ventricle. The second case involved a 68-year-old man who was asymptomatic and whose tumor was detected incidentally on echocardiogram. Both cases were treated surgically. An additional 71 cases of papillary fibroelastoma reported in the medical literature in Japan are reviewed.

Mid-term results of a closed biatrial procedure using bipolar radiofrequency ablation concomitantly performed with non-mitral cardiac operations

The long-term success rate of the Cox maze III procedure is excellent, although it has not been widely adopted because of the need for extensive incisions of the atria. In this study, we report our experience with a closed biatrial procedure using bipolar radiofrequency (RF) ablation for treating atrial fibrillation (AF) during non-mitral cardiac operations. Beginning in December 2004, a total of 19 patients underwent a closed biatrial procedure with bipolar RF energy. All the patients had a maze procedure plus a concomitant non-mitral operation. Except for several stabs to introduce the bipolar device, no incisions were made in either atrium. The first six patients were investigated with 64-slice multidetector computed tomography (MDCT), six months after the operation. Patients were followed-up monthly with a clinical examination and electrocardiography. There were no operative deaths. MDCT showed no evidence of coronary sinus stenosis. At one year of follow-up, 93% of the patients (14/15) were in sinus rhythm. The closed biatrial procedure using bipolar RF ablation is safe and effective in treating AF during open-heart surgery. This could be particularly beneficial for patients with AF who are undergoing a cardiac surgical procedure without opening the left atrium.

Off-pump coronary artery bypass grafting in a patient with Werner’s syndrome

Werner’s syndrome is a rare hereditary disorder that is characterized by premature aging. We report a case of off-pump coronary artery bypass grafting (OPCAB) in a 56-year-old man with Werner’s syndrome. We used an endoscopic vessel-harvesting system to harvest great saphenous vein grafts (SVGs) because this system helps minimize surgical wounds. This is important because poor wound healing is a prominent feature of Werner’s syndrome. Revascularization of the coronary arteries in this case was thought to improve his prognosis, although he had already outlived the average life-span of Werner’s syndrome. A detailed examination of the cardiovascular system should be performed in patients with this disorder.