Search PubMed⌕ Search

Biomedical subjects

M Kawauchi

Publications and source records attributed to M Kawauchi.

At least 55 records · Page 3Linked to original sources

Coronary artery bypass grafting by median sternotomy in patients with a tracheostoma.

The approach to the heart for open heart surgery in patients with a tracheostoma requires careful consideration. The presence of a tracheostoma interferes with the standard sternotomy and increases the risk of mediastinitis. We have successfully performed coronary artery bypass grafting in two patients with a tracheostoma using the limited median sternotomy and describe the surgical procedure used in these patients.

Coronary Artery Bypass↗

Oxygen utilization and hemodynamic response during exercise in children after Fontan procedure.

Eight patients, 9.1 to 16.5 years of age, were studied 2.8 to 8.5 years after Fontan operation. Oxygen utilization was determined during upright bicycle exercise. The cardiac index and stroke index were measured by echocardiography and the anaerobic threshold was determined. The results were compared with 10 patients after surgical closure of the atrial septal defect. Anaerobic threshold (AT) in Fontan patients was lower than in the control subjects. Oxygen consumption at each stage of exercise was significantly lower in the Fontan group compared with the control subjects. From the beginning of exercise until AT, the increase in stroke index was lower in the Fontan patients than in the control subjects. After that point, the stroke index decreased significantly in the Fontan patients while it remained almost at the same level in the control subjects. Significant correlations were observed between the oxygen pulses and the stroke index at AT both in the control and Fontan groups. These results suggest that impaired exercise capacity in Fontan patients is mainly due to a subnormal response of the stroke index at AT and to the decreased response of the stroke index and the heart rate at the maximal workload.

Adolescent↗

[Cardiac surgery in Jehovah's Witness].

Clinical experiences of 35 cardiothoracic operations in Jehovah's Witness patients were presented with special reference to a method of taking informed consent for surgery. At first the surgeon explained the details of the proposed surgery including its risks and benefits. He should also express his confidence in accomplishing the operation without blood transfusion. Otherwise he should not dare to perform the operation. The surgeon asked the patient to talk about his or her religious belief in transfusion denial. Then the surgeon was allowed to talk about his professional duty and ethical belief in saving the patient at all costs. Finally, both the patient and the surgeon would sign the document of informed consent without fully determining whether or not the patient would undergo transfusion at an unexpected situation since the possibility of such unexpected necessity of blood transfusion was believed extremely low by both the surgeon and the patient. The trust of the patient in the technique of the surgeon was the key to this agreement.

Blood Transfusion↗

[Open heart surgery in patients with a tracheostoma].

From April 1992 to May 1997 six patients underwent open heart surgery, who had tracheostoma at the time of operation. The sternum was divided completely in three patients whose tracheostoma lay highly on the neck, and it was cut transversely on the manubrium at the level of the first intercostal space, below which it was split longitudinally in two patients (partial median sternotomy). In one patient right anterolateral thoracotomy was used. There were no operative death and no complication related to infection. A left internal thoracic artery (LITA) was used successfully for a bypass conduit in two patients who underwent partial median sternotomy. Dissection of the proximal portion of the LITA through the second intercostal space prior to the sternotomy made the graft procurement feasible in this particular situation. In conclusion, full-length sternotomy is performable safely when the tracheostoma lies highly on the neck, and the partial sternotomy up to the midmanubrium is applicable, including LITA harvesting, even if it is just at the sternal angle.

Adolescent↗

[Extradural temporopolar approach for giant pituitary adenomas invading the cavernous sinus and parasellar regions].

OBJECTIVE: An extradural temporopolar approach has recently been used in the treatment of the parasellar, infrachiasmatic, or intracavernous regions. In this approach, the temporal (superficial) dural layer is separated from the deep layer (inner cavernous membrane) to expose the cavernous sinus extradurally. We report our experiences with 5 cases in which a giant pituitary adenoma invading the cavernous sinus and parasellar regions was resected via the extradural temporopolar approach. PATIENTS AND METHODS: Between January 1995 and December 1997, 60 patients with pituitary adenomas were operated on at Okayama University Hospital. The extradural temporopolar approach was used for 5 patients who had a giant pituitary adenoma invading the cavernous sinus and parasellar regions. The 5 patients were women aged from 32 to 62 years and presented with a visual dysfunction. Four patients had hormonally non-functioning pituitary adenomas and one had a growth-hormone secreting pituitary adenoma. RESULTS: The operations resulted in 1 total, 3 subtotal and 1 partial removal. There was no operative mortality or major morbidity. Transient oculomotor palsy occurred in 2 cases postoperatively. This approach provided excellent exposure of the tumor, relevant cranial nerves and arteries in and around the cavernous sinus through extradural retraction of the temporal lobe, allowing for sufficient resection of the intracavernous and parasellar portion of the tumor. Tumors invading the inferior portion of the clivus or the contralateral cavernous sinus could not be removed through this approach. CONCLUSION: Our findings suggest that the extradural temporopolar approach is useful for resection of giant pituitary adenomas invading the cavernous sinus and parasellar regions.

Adenoma↗

Detection of lipid peroxidation and hydroxyl radicals in brain contusion of rats.

To examine the relationship between the free radicals and brain tissue damage, we investigated the intensity of brain hydroxyl (OH) radical generation and lipid peroxidation in the rat contusion injury model. A unilateral contusion was induced by a weight-drop method. All rats were decapitated six hours after the injury, and brain samples were taken from three portions (core, peripheral, and distal) to examine the specific gravity as an indicator of brain edema, generation of OH using an electron paramagnetic resonance spectrometer (EPR), and malondialdehyde (MDA) and 4-hydroxyalkenals production. Analysis of the specific gravity revealed cerebral edema on the ipsilateral side in the injured group. The signal intensity of EPR in the core and peripheral portions in the contusion group was significantly higher than that in the distal portion of the contusion group and that of all portions in the control animals. No significant difference was observed between the core and peripheral portions of the contusion group. The MDA and 4-hydroxyalkenals production was significantly higher in the core and peripheral portions than in the distal portion of the contusion group and that of all portions of the control group. The degree of posttraumatic brain edema was closely correlated with the increase of DMPO-OH adduct, MDA, and 4-hydroxyalkenals. These results support the current concept that free radical production following traumatic brain injury may induce lipid peroxidation and may be the direct cause of edema formation.

Animals↗

Effects of lecithinized SOD on contusion injury in rats.

To analyze the effect of lecithinized superoxide dismutase (SOD) on superoxide accumulation after traumatic injury, the expression of Cu,Zn-SOD mRNA was examined after contusion in rat using Northern blotting. As determined by specific gravity, lecithinized SOD decreased brain edema. The expression of Cu,Zn-SOD mRNA increased at the core, peripheral and contralateral hemisphere of injury. These increases were then suppressed by lecithinized SOD. Our results support the hypothesis that superoxide may play an important role in edema formation after contusion, and that lecithinized SOD appears to prevent brain edema through a protective effect against superoxide injury.

Animals↗

Hemoptysis from an emphysematous bulla developing after open-heart surgery: report of a case.

We present herein the case of a 62-year-old woman with an emphysematous bulla who developed intractable hemoptysis 16 days after undergoing mitral and aortic valve replacement with tricuspid annuloplasty. A bronchoscopic examination with balloon occlusion of the bronchial lumen revealed that the blood source was the right middle lobe bronchus. A computed tomographic (CT) scan of the chest subsequently demonstrated a blood-filled emphysematous bulla in the right middle lobe. A right middle lobectomy was performed and the bulla was observed to be swollen with clotted blood. The respiratory tract bleeding stopped immediately after the lobectomy. Pathohistological examinations suggested that disruption of the pulmonary vessels in the wall of the bulla had caused the respiratory tract bleeding.

Aortic Valve Insufficiency↗

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

Accurate 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.

Animals↗

Mitral valve repair through combined left atrial and ventricular approach for congenital mitral stenosis.

A 3-year-old boy underwent mitral valve repair for congenital mitral stenosis through combined superior-septal atriotomy and apical left ventriculotomy. The operation was performed safely with excellent exposure of the subvalvular apparatus by the ventricular approach, while sufficient visualization of the valvular lesion was obtained by the atrial approach. Postoperative echocardiography demonstrated normal left-ventricular motion and no residual mitral stenosis.

Cardiac Surgical Procedures↗

Effects of lecithinized superoxide dismutase on traumatic brain injury in rats.

Only small amounts of superoxide dismutase (SOD) are present in the extracellular space to scavenge excess amounts of superoxide anions (02-) released after traumatic brain injury (TBI). Experiments were performed in rats with cerebral contusion produced by weight-drop technique. We investigated the effects of exogenous lecithinized SOD (PC-SOD) on accumulation of 02- produced in our model, by measuring the level of SOD activity (using the NBT-reducing method) and the expression of copper, zinc-SOD (Cu, Zn-SOD) mRNA (by Northern blot analysis). As determined by tissue-specific gravity, administration of PC-SOD reduced brain edema in the periphery of the lesion 6 h after contusion. SOD activity increased in the peripheral region at 30 min after contusion, but returned to normal levels at 6 h after TBI. Administration of PC-SOD increased SOD activity up to 6 h after TBI. The expression of Cu, Zn-SOD mRNA increased in the core region, peripheral portion, and contralateral hemisphere up to 6 h after TBI, then was suppressed in all three regions by PC-SOD. Our results confirm the important role of 02- in the development of brain edema after TBI and indicate that PC-SOD diminishes brain edema through a protective effect against 02-.

Animals↗

Surgical repair for atrial septal defect in patients over 70 years of age.

Atrial septal defect (ASD) is the most common congenital heart anomaly encountered in adults. For patients over 60 years old, acceptable operative mortality and symptomatic improvement following surgery have been reported. We reviewed patients with ASD aged over 70 years and studied their preoperative hemodynamics, the surgical procedures used and the results. Between January 1994 and December 1996, 18 patients over the age of 40 years underwent surgical repair of ASD. Four patients were over 70 years of age (Group A). The other 14 patients were studied as a control group (Group B). We compared the preoperative clinical status, hemodynamic data, and surgical results between the two groups. The postoperative clinical status of Group A was studied during the follow-up period. The NYHA functional class of the elderly patients was greater than that of the middle-aged patients. None of the elderly patients had pulmonary hypertension. Moderate or severe tricuspid valve regurgitation (TR) due to annular dilatation was found, and tricuspid annuloplasty was performed in all four elderly patients. There were no operative or hospital deaths in either group. The NYHA functional class and TR improved in all the aged patients after surgery. In order to prevent progressive tricuspid annular dilatation due to an intraatrial left to right shunt, surgical closure of ASD should be performed for physically active adult patients.

Adult↗

Mitral valve repair with extensive resection of the anterior leaflet for regurgitation due to Barlow's disease. Report of a case.

We recently performed mitral valve repair for a case of mitral regurgitation due to Barlow's disease, which is relatively rare in Japan. Both the anterior and posterior leaflets were affected by advanced myxomatous change, and appeared markedly thickened and redundant. Although extensive resection of the anterior leaflet is not a generally accepted method, nearly one fourth of the anterior leaflet was resected in this case. Now, at 36 months after the operation, there is only trivial regurgitation and the patient is doing well and without symptoms. We believe that extensive resection of the anterior leaflet can be a useful treatment for repair of a redundant anterior leaflet with excess tissue.

Cardiac Surgical Procedures↗