PubMed Health⌕ Search

Biomedical subjects

A Mitsumaru

Publications and source records attributed to A Mitsumaru.

29 records · Page 2Linked to original sources
PubMed1994

[Preliminary clinical results of surgery for type A acute aortic dissections using gelatin-resorcin-formaldehyde glue].

We used gelatin-resorcin-form-aldehyde (GRF) glue to fuse the false lumen of type A acute aortic dissection in four patients. All were operated on within 3-24 hours after onset, and gluing of the two cylinders of the dissecting aorta could be done safely in a short time. Initial intimal tears were located in the transverse aorta in three patients and in the proximal descending aorta in one. Simple transection and end-to-end anastomosis of the ascending aorta was done for the first two cases. But in the last two patients, we resected the intimal tear in the transverse aorta and applied GRF glue to the stump of the aortic arch and to that of the aortic root, followed by graft replacement of the ascending aorta. There were no hospital deaths. But we had to reoperate on one patient five months after the first operation due to potentially residual dissection in the aortic root. GRF glue is a very useful adhesive for acute aortic dissection operations, but further refinement of the operative technique using it is necessary.

Acute Disease↗
PubMed1994

[The surgical treatment of coarctation of the aorta and interruption of the aortic arch in the first three months of life--effectiveness of temporary bypass between the pulmonary artery and the descending aorta].

From February 1987 to January 1994, we operated on 24 patients with coarctation of the aorta (CoA) and 9 patients with interruption of the aortic arch (IAA). A policy of staged repair was followed, consisting of reconstruction of the aortic arch with pulmonary artery banding and ligation of the ductus arteriosus in the first stage and intracardiac repair with pulmonary artery band removal in the second stage. In recent cases an extended aortic arch anastomosis was performed using a heparin-coated "shunt tube" between the pulmonary artery and the descending aorta to maintain blood flow to the lower half of the body during aortic cross-clamping. The use of the shunt increased intraoperative urine output (p < 0.05). This technique may allow patients whose condition is poor to undergo aortoplasty more safely. One patient died. This patient had CoA and total anomalous pulmonary venous return, who underwent a one-stage repair, in violation of our policy (early mortality 3.0%). There were two interim deaths before the second stage repair. At present, 18 patients have undergone staged intracardiac repair, including VSD closure (14 cases), Jatene's procedure (1), Ratelli's procedure (1), Damus-Kaye-Stansel (DKS) procedure (1), total cavo-pulmonary connection (TCPC) + DKS procedure+annuloplasty of a common atrioventricular valve (1). There were two early deaths and one late death following intracardiac repair, all in patients with IAA plus VSD.

Anastomosis, Surgical↗
PubMed1992

Surgical reconstruction of an ascending aortic dissection in Takayasu's arteritis.

A 45-year-old Japanese woman with Stanford type A dissecting aortic aneurysm underwent a reconstructive operation on the ascending aorta. Histopathological diagnosis was Takayasu's arteritis in the chronic and inactive phase. It is very rare that a dissecting aortic aneurysm results from Takayasu's arteritis. Long-standing hypertension and fragility of the aortic media due to disruption of elastic fibers were suspected to cause dissection in the entire aorta in this case.

Aortic Dissection↗
PubMedDate not supplied

Development and clinical application of a next generation implantable echocardiography probe for monitoring cardiac function under assisted circulation after open heart surgery.

Post-operative cardiac function generally is monitored by electrocardiography, invasive measurement of blood pressure, and determination of hemodynamic variables, such as pulmonary pressures and cardiac output with a Swan-Ganz catheter. In recent years, transesophageal echocardiography has been introduced into clinical use, but it is not a popular method of monitoring for various reasons, including the difficulty of application to unconscious post-operative patients. Since 1991, we have been developing a small implantable echocardiography probe. This probe was tested in 15 patients who underwent open heart surgery for severe left ventricular hypofunction, and its clinical utility was demonstrated. No deaths occurred in this series. The implantable echocardiography probe allowed post-operative cardiac function to be monitored in real-time. The ejection fraction, the cardiac output, the status of valves after valvuloplasty, the presence of cardiac tamponade, and other variables could be assessed. The echocardiography probe can be positioned at any site where specific information is desired during surgery. It can be inserted as easily as a pericardial drain tube and is removed in the same manner when no longer necessary. This probe has the potential to be useful for monitoring patients on assisted circulation after cardiac surgery.

Assisted Circulation↗
PubMedDate not supplied

Feasibility study of vascular-endoscopic valvuloplasty. Using a laser and flexible endoscope.

Percutaneous balloon valvuloplasty is generally accepted, but post procedural complications limit its efficacy and reduce long-term success. To eliminate these risks, the authors explored the feasibility of cardioscopy guided percutaneous laser valvuloplasty in an experimental setting. The combined working model consisted of a separate balloon tipped thin fiber optic endoscope, laser balloon catheter, and a Nd-YAG laser transmitter. A porcine pulmonary valve was used as our in vivo target of laser ablation in a beating heart. Under general anesthesia, the endoscopic catheter is delivered into the pulmonary valve area through either the internal jugular or femoral vein under fluoroscopy. Positioning the pulmonary apparatus coaxial to the endoscopic visual field by manipulation of the catheter allowed for targeting and ablation of the commissure of the pulmonary valve under endoscopic view through the balloon filled with saline solution. The ablation energy was 15-30 W, 0.5-1.0 sec, and 2,000-3,000 J total. The animal was then killed and histopathologic study of the ablated area was done. The commissure of the pulmonary valve was smoothly ablated in 4 cases, and the entire ablation procedure was successfully witnessed through endoscopy. The authors encountered some difficulty in laser targeting, limitations to the endoscopic field of vision, and difficulty in holding the position of the apparatus in the beating heart. These are the barriers to overcome for future clinical application of this procedure. However, these results indicate the clear possibility of future use of cardioscopy guided percutaneous laser valvuloplasty in a clinical setting.

Animals↗
PubMedDate not supplied

A new endo aortic occlusion balloon for limited access cardiac surgery: development and clinical evaluation.

In recent years, minimally invasive cardiac surgery (MICS), or limited access cardiac surgery, has been presented as a promising operative procedure. We developed a new balloon device that is inserted directly into the ascending aorta to stop the heart during limited access cardiac surgery. The balloon has a three lumen structure: balloon lumen port, cardioplegia/vent lumen port, and aortic root lumen port. This direct EAC balloon catheter, designed to be inserted directly into the ascending aorta, is different from the Heartport system. The Heartport EAC balloon catheter is inserted into the aorta via an artery in the lower limb, making lower limb arterial disease a key concern. Our Direct Endo Aortic Clamp (EAC) balloon overcomes this problem. The device was clinically used in seven cardiac cases. All patients were discharged within 5 postoperative days, confirming the utility of the device.

Aorta↗
PubMedDate not supplied

Efficiency of an air filter at the drainage site in a closed circuit with a centrifugal blood pump: an in vitro study.

In a closed circuit with a centrifugal blood pump, one of the serious obstacles to clinical application is sucking of air bubbles into the drainage circuit. The goal of this study was to investigate the efficiency of an air filter at the drainage site. We used whole bovine blood and the experimental circuit consisted of a drainage circuit, two air filters, a centrifugal blood pump, a membrane oxygenator, a return circuit, and a reservoir. Air was injected into the drainage circuit with a roller pump, and the number and size of air bubbles were measured. The air filter at the drainage site could remove the air bubbles (>40 microm) by itself, but adding a vacuum removed more bubbles (>40 microm) than without vacuum. Our results suggest that an air filter at the drainage site could effectively remove air bubbles, and that adding the filter in a closed circuit with a centrifugal blood pump would be safer.

Animals↗
PubMedDate not supplied

Experimental study of extraaortic balloon counterpulsation as a bridge to other mechanical assists.

A special extraaortic balloon was developed that can be placed around the ascending aorta. This balloon can easily support the heart temporarily in a median sternotomy field, especially in cases in which it is difficult to use intraaortic balloon pumping because of peripheral arterial disease. The goal of this study was to judge the applicability of this extraaortic balloon counterpulsation. An extraaortic balloon was placed around the ascending aorta of eight adult canines. Two heart failure models were used in this study: group A-moderate heart failure; group B-severe heart failure. In group A, the aortic systolic pressure was significantly reduced (9.3%, p < 0.01), but in group B, there was no significant change. In group A, there was a significant increase in cardiac output (12.0%, p < 0.01), but in group B, there was no significant change. The endocardial viability ratio in both groups significantly increased (group A: 11.3%, p < 0.01; group B: 11.9%, p < 0.05). An extraaortic balloon around the ascending aorta is easily applicable through a median sternotomy, and can be used as a bridge to more powerful mechanical assists when intraaortic balloon pumping cannot be used.

Animals↗
PubMedDate not supplied

Experimental study of combination of extraaortic balloon counterpulsation and ventricular assist cup to acute heart failure in dogs.

The goal of this study is to evaluate the applicability and effectiveness of combination support of the extraaortic balloon (EAB) and the ventricular assist cup (VAC) to the acute heart failure model. Under general anesthesia, 10 adult dogs were used. Through the median sternotomy, EAB was placed around the ascending aorta and VAC in the pericardial cavity. After heart failure was induced by administration of propranolol, the on-off tests of devices were done as follows. Only EAB was used, and only VAC was used and both devices were used. Regional blood flows (RBFs) of both ventricles, liver kidneys, and brain were measured by colored microsphere technique. Hemodynamic parameters were also measured. In heart failure model, cardiac output (CO) decreased to 66% of control value. In the group assisted by EAB, aortic peak-diastolic pressure and RBFs of both ventricle and brain increased significantly. In the group assisted by VAC, CO and RBFs of all but the left ventricle significantly increased. In the group assisted by EAB and VAC, aortic peak-diastolic pressure, CO, and all five RBFs significantly increased. These results suggest the combination of EAB and VAC is applicable and effective and would be a promising implantable device for the chronic heart failure.

Acute Disease↗
PubMedDate not supplied

Video assisted thoracoscopic and cardioscopic radiofrequency Maze ablation.

The authors examined the feasibility of transthoracic radio frequency Maze ablation of atrial fibrillation using video assisted thoracoscopy and cardioscopy in the experimental setting of a beating porcine heart. In six pigs under general anesthesia, the left atrium was viewed using a video assisted thoracoscopy system (VATS), and radiofrequency linear ablation of the left atrial wall was carried out using a radiofrequency ablation catheter (HAT200S:OSYPKA) inserted through a trocar port. The right atrium was also ablated in the same manner under VATS. In six other pigs, intravenous radiofrequency ablation by cardioscopic catheter device was carried out. Atrial fibrillation was provoked by acetylcholine injection plus rapid atrial pacing. The thoracoscopic visual field created for radiofrequency catheter ablation from a transthoracic approach and the cardioscopic visual field from an intravenous approach were sufficient, and safe positioning of the ablation catheter device on the atrial epicardium and endocardium, which enabled linear ablation of the atrium, was obtained. The Optimal setting for ablation was 70-80 degrees C/ 30 sec duration per each ablation. This process was monitored and documented by a video system through the thoracoscope and cardioscope, and results were confirmed by postmortem macrohistologic examination. In conclusion, the authors' results suggest the potential usefulness of the combination of transthoracic radiofrequency catheter ablation with video assisted thoracoscopic and cardioscopic linear ablation of atrial fibrillation, and the possibility that use of this system might eliminate the need for open heart Maze surgery.

Acetylcholine↗