Munemoto Endoh

Hemodynamic effects of carbon dioxide insufflation under single-lung ventilation during thoracoscopy.

BACKGROUND The hemodynamic effects of carbon dioxide insufflation under single-lung ventilation were studied in 22 consecutive thoracoscopic harvests of the left internal mammary artery, which was used for minimally invasive coronary artery bypass grafting. METHODS An electrocardiograph, arterial catheter, Swan-Ganz catheter, and transesophageal echocardiograph were used to monitor seven hemodynamic variables. Baseline data were obtained during ventilation of both lungs and the measurements were repeated after the left lung was collapsed and at 5 and 30 minutes after hemithorax insufflation with low-flow (2 to 3 L/minute) carbon dioxide gas was begun. The intrapleural pressure was maintained at 8 to 10 mm Hg. RESULTS Thoracoscopic harvest of the internal mammary artery was completed in all cases with a mean insufflation time of 44+/-12 minutes. There were no significant changes in the mean arterial pressure, heart rate, cardiac index, and left ventricular ejection fraction throughout the procedure, whereas the central venous pressure, mean pulmonary arterial pressure, and pulmonary capillary wedge pressure (p < 0.05 for each variable) during insufflation. CONCLUSIONS Low-flow carbon dioxide insufflation into the left hemithorax with an intrapleural pressure of 8 to 10 mm Hg under selective right-lung ventilation does not compromise the human heart with normal to moderately depressed function and can be an efficacious adjunct in specific thoracoscopic procedures.

Ultrasonic coagulator for video-assisted internal mammary artery harvest

BackgroundThe Harmonic Scalpel (HS; Ethicon Endo-Surgery, Cincinnati, OH, USA) is an ultrasonic coagulator that generates less heat than electrocautery. We compared canine internal mammary arteries (IMAs) harvested using the HS or electrocautery and reviewed the early clinical outcome after thoracoscopic IMA takedown with the HS.MethodsUsing HS and bipolar electrocautery (BE), 51 and 49 IMA branches, respectively, in six mongrel dogs were divided. The divided branches were subjected to a pressure tolerance test. The impact of coagulation on the main trunk was investigated microscopically. Thoracoscopic IMA harvesting with the HS was performed in 41 patients. Seven human IMA segments including 10 branches were examined microscopically. Postoperative angiography of 40 IMA grafts (97.6%) was performed.ResultsAll the IMA branches withstood intraluminal pressures up to 250 mmHg. With BE, coagulation reached the adventitia of the main trunk in six segments (12.2%), but the HS caused no injury. Thoracoscopic IMA harvesting with excellent hemostasis was achieved using only the HS in all 41 patients. The main trunks of the human IMA segments were microscopically intact, and postoperative angiography demonstrated that the IMA grafts were intact.ConclusionThe HS appears to be a reliable coagulator for thoracoscopic IMA harvesting with minimal damage.

Conventional repair and operative stent-grafting for acute and chronic aortic dissection

Conventional graft replacement of the ascending aorta and surgically endovascular stent-grafting of the proximal descending aorta were performed concomitantly in a 82-year-old woman with an acute DeBakey type II aortic dissection and a chronic DeBakey type IIIb aortic dissection. Postoperative computed tomography and angiography showed the adequately replaced ascending-aortic prosthesis, the well-expanded stent-graft, and the thrombosed false lumen in the descending aorta.

Expression of cell division cycle 2 kinase transcription in chronically rejected cardiac allografts of nonhuman primates.

SummaryAccurate diagnosis and prevention of graft arteriosclerosis, known as chronic rejection, is critical to the success of cardiac transplantation, but often is difficult to attain. Expression of cell division cycle (cdc) 2 kinase, which plays a critical role in cell transition through the G2/M phase, is critical to the proliferation of vascular smooth muscle cells. To evaluate the usefulness of cdc2 kinase expression for pathophysiological analysis of chronic rejection, heterotopic cardiac transplantation was performed in Japanese monkeys (n=7). Standard reverse transcriptase-polymerase chain reaction (RT-PCR) and in situ RT-PCR were performed to evaluate the expression. In the coronary arteries of chronically rejected allografts, enhanced cdc2 kinase expression was observed in thickened intima and media, while none was expressed in native hearts. The cdc2 kinase was also expressed before the intimal thickening occurred. These results indicate that enhanced expression of cdc2 kinase is a sensitive indicator for chronic cardiac rejection; targeting cdc2 kinase may be a viable gene therapy for prevention of this vasculopathy.

Ontogeny of antipig xenoantibody and hyperacute rejection.

BACKGROUND Neonatal primates have been reported to receive pig hearts without hyperacute rejection (HAR). We examined the ontogeny of the anti-pig xenoantibody (XenoAb) and HAR in the neonatal and infant monkeys. METHODS Twenty-six serum samples from 15 monkeys ages 14-192 days were subjected to hemagglutination titration against pig erythrocytes. Ten pig hearts were heterotopically transplanted into the monkeys. RESULTS Six monkeys, ages 52-114 days, received pig hearts without HAR, and those ages 129-191 days hyperacutely rejected them. XenoAb titers were increased according to the age (Spearmans rank correlation value=0.909 (P<0.01)). XenoAb titers in 16 monkeys <4 months were significantly (P<0.01) lower than those in 10 monkeys >4 months. CONCLUSIONS Anti-pig XenoAb titers increased with the age of the monkeys. XenoAb levels in monkeys >4 months are high enough to reject pig hearts hyperacutely.

Video-assisted micabg for the patient with right mammary carcinoma —a case report—

A 69-year-old female with advanced right mammary carcinoma presented to us with diffuse stenosis of the proxymal left anterior descending artery (LAD). Right mastectomy had been suspended. The LAD was treated with minimally invasive CABG (MICABG) assisted with a thoracoscopic procedure. The left internal thoracic artery (LITA) was taken down through thoracoscopy from the upper margin of the 1st rib to the lower margin of the 5th rib using only the Harmonic Scalpel (Ethicon Endo-Surgery). Coronary anastomosis to the LAD was completed without cardiopulmonary bypass through a small thoracotomy on the anterior 4th intercostal space. The operation time was 4 h 30 min and the blood loss was 120 ml. Post operative course was uneventful. Doppler study and angiography demonstrated patent LITA to the LAD. Right mastectomy was achieved 29 days after MICABG. MICABG can be a veneficial alternative method for the patient with malignant disease, allowing quick convalescence and early cancer operation. Thoracoscopy allows for sufficient LITA harvest up to the 1st rib or higher with the Harmonic Scalpel.

Nonmuscle myosin heavy chain and nuclear factor-kappa B expression in pig-to-primate xenotransplanted hearts.

IT IS well known that angiopathy on the intima of the blood vessels causes atherosclerosis. The damage on the intima injures endothelial cells and then smooth muscle cells (SMCs) of the media give rise to hypertrophy. The phenotypic change of SMCs should be necessary for the hypertrophy of the SMCs. Nonmuscle type myosin heavy chain (SMemb), which is an embryonic isoform of myosin heavy chain, is specifically expressed in fetal aorta and proliferating SMCs. Nuclear factor-kappa B (NF-k B) regulates multiple genes involved in vascular remodeling as a transcriptional factor. SMemb and NF-k B should be the important factors for the dedifferentiation and phenotypic change of SMCs. In the process of xenograft rejection, the same phenomenon as angiopathy has been reported and proliferating SMCs have been observed in blood vessels of rejected tissues. In this study, the expression pattern of SMemb and NF-k B in pig-toprimate xenotransplanted hearts were investigated. It will be useful to understand the mechanisms of xenograft rejection, particularly in cardiovascular remodeling.