Fixation of a Myocardial Lead via a 5th Costal Cartilage Resection Approach / 日本心臓血管外科学会雑誌

Median sternotomy is commonly used for suture fixation of a myocardial lead. Instead of this conventional technique, we used the technique of resecting the 5th costal cartilage through a small horizontal skin incision at the left 5th sternocostal junction in 33 patients, between 1980 and 2001. Here we describe this procedure, as well as the outcome of patients who underwent this myocardial lead fixation procedure. A skin incision of about 6 to 8cm was made in the left 5th intercostal space. Approximately 5cm of the 5th costal cartilage was resected through the skin incision. Then, a myocardial lead was sutured on to the anterior wall of the right ventricle. The generator was generally placed in the upper subcutaneous space of abdomen. Additional costal cartilages were removed in 7 patients in whom a larger operating field could not be obtained initially. The electrode was sutured to the right ventricular wall in 28 patients, right atrial wall in 6 patients, and the left ventricular wall in 5 patients. The mean operation time was 150min and mean bleeding during operation was 82ml. Long-term results (258 months at the longest, at the time of writing) showed that all the patients did well, except for one adult who suffered cerebral infarction, and one child with pacing failure. Based on these findings, we believe that this procedure is minimally invasive method, and is good for fixation of a myocardial lead.

Long-Term Results of Aortic Valve Replacement Using a 19mm Bileaflet Valve / 日本心臓血管外科学会雑誌

We studied cardiac function and outcome long after aortic valve replacement using a 19mm bileaflet valve. The subjects consisted of 10 of 12 patients living 10 or more years after the operation and 7 of 8 living 5-9 years after the operation. We measured the left ventricular ejection fraction (LVEF), %fraction shortening (%FS), left ventricular diastolic dimension (LVDd), systolic dimension (LVDs), PWT, IVST, and LV-aortic pressure gradient (PG) of in 6 patients each in 10 more years after the operation (Group I) and 5-9 years after the operation (Group II) who underwent ultrasonography, and calculated the left ventricular mass index (LVMI). No statistically significant differences were seen in either parameter in either group. Prognosis was 1 cardiac 2 cancer deaths each in 10 or more years after the operation group. The cumulative survival rate was in 85.7% post operative 5-9 years and 72.7% in 10 years. Although cardiac function was maintained in both groups, more observation is needed from now on because the pressure difference or LVMI may increase.

An Experiment Study on the Surgical Production of Atrioventricular Block by Direct Current Electrocautery / 日本心臓血管外科学会雑誌

Therapeutic AV block has been preferred in drug-resistant cases, although concurrent pacemaker implantation is mandatory. If it is technically possible to control surgically produced AV block to the first or second degree, this would certainly make conjoined use of a demand pacemaker quite unnecessary. This concept prompted us to undertake an experimental study, in which we succeeded in producing first to third degree AV block in 30 mongrel dogs through ablation of the AV node by applying direct current from the epicardial side. From immediately after starting ablation a stepwise progressive prolongation of the PQ interval was noted, with eventual development of third degree AV block. Histopathologically, the lesion consisted of coagulation necrosis which involved an average of 95% of the AV node in animals developing third degree AV block and an average of 66% in those with first degree AV block. These results suggest that our surgical procedure, if technically refined to permit ablation of the AV node to the desired extent, will provide an acceptable means of treating supraventricular tachyarrhythmia without requiring permanent pacemaker implantation.

Argon Beam Coagulator as an Adjunct to Surgery in the Treatment of Drug-Resistant Ventricular Tachycardia. Basic Experiments and Clinical Application / 日本心臓血管外科学会雑誌

Surgery and cryoablation have been the preferred method for treating drug resistant ventricular tachycardia (VT). Cryoablation, the therapeutic usefulness of which has been documented in many reported studies, is nevertheless not free from technical difficulaties. The advent of Bard^® System 6000 Argon beam coagulator (ABC) as a new procedure alternative to cryoablation offered us a hope for solving problems with conventionally used techniques. Preliminary experiments with this device on dog myocardium permitted us to determine therapeutically adequate irradiation time and depth of cauterization and to locate an optimum area of myocardium to be coagulated. Based on these experiences, an attempt was made to use ABC as an adjunct to surgery in the surgical treatment of 4 patients with monofocal non-ischemic VT. In 1 of these 4 patients, VT disappeared postoperatively, making use of antiarrythmia drugs quite unnecessary, while in the remaining 3, a marked diminution of ventricular arrhythmia with a consequent reduction of drug dosage was achieved, use of the device thus being judged to be beneficial. These results led to the conclusion that ABC will provide a valuable adjunct to operation in selected cases of VT and, if the probe and other appliances are further refined, can reasonably be anticipated to be used as frequently as cryoablation.

A Case of Recurred Left Ventricular Myxoma / 日本心臓血管外科学会雑誌

Myxoma of the left ventricle is exceedingly rare and to the best of our knowledge not a single case of its recurrence has been reported in Japan. We have recently experienced a case in which a myxomatous tumor of the left ventricle recurred at the same site as the primary lesion 2.5 years after operation and was treated by surgical excision. The patient was a 28-year-old female who, under the diagnosis of myxoma of the left ventricle, underwent surgical removal of the tumor and mitral valve replacement at her age of 25 years. Although her postoperative course was uneventful, she was noticed, at her age of 28 years, of her inaudible prosthetic valve clicks on auscultation at the outpatient service. Echocardiography revealed a tumor mass in the left ventricle, which tended to grow with the elapse of time. Echocardiography on rehospitalization disclosed a mobile cystic tumor on the posterior wall of the left ventricle, while pulmonary arteriography also revealed a movable tumor in the left ventricle. Intraoperatively, there was noted a solid tumor, composed partly of cystic structure, on the posterior wall of the left ventricle and quick pathology led to a suspected diagnosis of myxoma. Since the tumor was found to have involved the ventricular septum and myocardial tissue of the posterior wall of the left ventricle, its complete surgical excision was impossible. The tumor, with its growth pattern and morphology, was diagnosed as a malignant clinical behavior one, although histopathological evidence indicates its benignancy.