Biomedical subjects

N Mukohara

Publications and source records attributed to N Mukohara.

At least 37 records · Page 2Linked to original sources

PubMed1994

[Surgical treatment of incomplete endocardial cushion defect in elderly patients].

We experienced 5 surgical cases of incomplete endocardial cushion defect who were 50 years old or older. Preoperatively, 3 cases were in New York Heart Association (NYHA) class II and 2 in class III. Catheterization study showed that systolic pulmonary arterial pressure was 24 to 48 (average; 38) mmHg and pulmonary-to-systemic flow ratio was 3.4 to 8.1 (average; 5.2). Left ventriculography showed mitral valve regurgitation (grade I-1 cases, grade II-3, grade III-1) with cleft and goose neck sign in all cases. Single atrium and patent foramen ovalis were associated in each one case. At operation, suture of mitral cleft and patch closure of ostium primum defect from mitral valve side were performed. Postoperatively, NYHA class, cardiomegaly, pulmonary arterial pressure and mitral regurgitation improved remarkably in all patients. During the follow-up period from 18 to 126 months (average; 57), right bundle branch block and supraventricular arrhythmia in electrocardiogram disappeared in 3 of 4 and 4 of 5 cases, respectively. Surgical treatment and postoperative course of incomplete ECD were reviewed in over-50-year-old patients, in reference to 17 surgical cases in Japan.

Electrocardiography↗

PubMed1993

Surgical treatment of cardiac myxoma and its complications.

A total of 20 patients (15 women, five men) were operated on for cardiac myxoma. Their ages ranged from 17 to 74 (mean 56) years. Myxoma was located in the left atrium in 18 patients and in the right in two. Systemic embolism occurred in eight patients, causing cerebral infarction in three, ischaemia of the extremities in two, occlusion of the external carotid artery with cerebral infarction in one, myocardial infarction in one and pulmonary infarction in one. Five patients with severe congestive heart failure required emergency surgery. All myxomas were removed using cardiopulmonary bypass with excision of the attachment walls. Details are given of additional surgery performed on some of the patients. Two patients died, one from pulmonary insufficiency after emergency surgery and the other from an unrelated problem. The remaining 18 patients showed a good recovery and are doing well with no intracardiac recurrence, although one with cerebral infarction underwent clipping of an aneurysm, which was detected later in the infarcted area.

Adolescent↗

PubMed1993

[Aortic arch reconstruction without aortic cross-clamping using separate extracorporeal circulation].

Between March 1991 and October 1992, 21 consecutive patients underwent aortic arch reconstruction without aortic cross-clamping using separate extracorporeal circulation in combination with retrograde blood cardioplegia (Non-clamping selective cerebral perfusion). Twelve patients had true arch aneurysm, 3 had acute aortic dissection and 6 had chronic aortic dissection including 2 redo cases. Cardiopulmonary bypass (CPB) was instituted with an arterial cannula in the femoral artery and 2 cannulae in both vena cavae. When tympanum temperature was lowered to 20 degrees C by central cooling, CBP was stopped temporarily. As soon as the aortic arch was incised longitudinally together with aneurysm, flexible 12 Fr. balloon cannulae were inserted into the three arch arteries via their orifices and selective cerebral perfusion was started. The perfusion flow was kept between 0.3 L/m2/min and 0.35 L/m2/min with the pressure of catheter tip from 30 to 60 mmHg to keep tympanum temperature 18 degrees C. Heart was protected by retrograde continuous cold blood cardioplegia. During arch correction, the descending aorta was occluded by a balloon then abdominal viscera were perfused via a femoral return cannula and rewarming to 25 degrees C was started to prevent visceral organ failure and coagulopathy. The time of separate perfusion ranged 20 to 161 minutes with a mean of 99.9 minutes. Except one patient who died of pneumonia, 20 patient (95.2%) were discharged and doing well. No cerebral complication, myocardial infarction, lung bleeding and coagulopathy occurred. In order to prevent the infarction by debris and to protect vital organs, this method is reliable for aortic arch reconstruction.

Aged↗

PubMed1993

[Surgical treatment of coronary artery-pulmonary artery fistula].

We experienced 4 cases of left coronary artery-pulmonary artery fistula. Two cases had small fistulas associated with atherosclerotic coronary lesions, and the other 2 had large fistulas with aneurysmal enlargement. In the former 2 cases, ligation of the fistulas and closure of the opening of fistula into the pulmonary artery through pulmonary arteriotomy were performed together with coronary artery bypass grafting and left ventricular aneurysmectomy. In one of the latter 2 cases, the fistula arising from the anterior descending branch was ligated and the opening of fistula draining into the pulmonary artery was closed through pulmonary arteriotomy. In another case, both openings of the fistula into the anterior descending branch and the pulmonary artery were closed from inside through incision of the dilated fistula. In all 4 cases, operations were performed using cardiopulmonary bypass and retrograde coronary perfusion, which could afford good heart protection even in cases with coronary lesions and coronary steal phenomenon. All cases went an uneventful postoperative course. Postoperative angiograms showed disappearance of the fistulas in 3 cases. In one case, however, residual fistula was found because a fine fistula might be overlooked. In such a case with complicated fistulas with aneurysmal enlargement, fistulas should be examined carefully through incision of the enlarged anomalous vessels. In this paper, diagnosis, operative indication and treatment for coronary artery-pulmonary artery fistula were discussed.

Adult↗

PubMed1993

[Surgical treatment of left atrial myxoma with coronary arterial lesion].

We experienced two patients of left atrial myxoma with coronary arterial lesion. One patient, who was a 52-year-old female, was transferred to our institute with the diagnosis of acute myocardial infarction. The coronary angiogram showed an abrupt 99% stenosis of posterolateral branch of circumflex artery with no atherosclerotic lesion, and the echocardiography revealed a left atrial myxoma disturbing the blood flow across the mitral valve. She was in congestive heart failure with pulmonary hypertension, and underwent an emergency removal of the myxoma under cardiopulmonary bypass. Another patient, who was a 70-year-old male, was admitted to our institute with the chief complaint of chest pain. The coronary angiogram showed an 75% atherosclerotic stenosis of the right coronary artery, and the echocardiography revealed the left atrial myxoma. He received a removal of myxoma and a coronary artery bypass grafting simultaneously. These 2 patients went a good postoperative course and live a lively life with no local recurrence. In this paper, the surgical treatment of left atrial myxoma with coronary arterial lesion was reviewed.

Aged↗

PubMed1993

[Surgical treatment for true aneurysm of the deep femoral artery, and a review of literatures in Japan].

A true aneurysm of the deep femoral artery is very rare among peripheral aneurysms because of its anatomical position and characteristics of wall tissue. An early operation is mandatory because it has a tendency to become a large size and to rupture. During the last eight years, we experienced two cases. One ruptured case underwent only resection of aneurysm and another case received an additional reconstruction of deep femoral artery using saphenous vein graft. Both of them are doing well postoperatively. In this paper, a review of 24 cases including these two in Japanese literature was discussed.

Aged↗

PubMed1993

[Medtronic model 6500 temporary myocardial pacing lead: a report of clinical assessment until three weeks after cardiac surgery].

Medtronic model 6500 heart wire as a right ventricular electrode was assessed in 41 postoperative cases. R-wave amplitude, slew rate, peak-to-peak, output, current, and resistance were measured by Medtronic A-V pacing system analyser, model 5311, for three weeks after open heart surgery. These parameter changed until the 7 th postoperative day, but did not change significantly thereafter. Output and current did not exceed beyond 10 V and 20 mA respectively, where there is limitations of usually available pacemaker. No complication was encountered. These results showed that this heart wire was reliably useful even until 3 weeks after open heart surgery.

Adolescent↗

PubMed1993

[Surgical treatment of thoracic and thoracoabdominal aneurysm during partial cardiopulmonary bypass].

We operated on 3 patients with thoracic or thoracoabdominal aneurysm using partial cardiopulmonary bypass with right atrial drainage. The first patient was in the preshock state with severe chest and back pain. The aortography and enhanced computed tomography showed a thoracic aneurysm of 70 mm in maximum diameter ruptured into the extrapleural space and an emergency surgery was performed. The second patient was also in the preshock state with chest and back pain. The enhanced computed tomography showed a thoracoabdominal aneurysm of 120 mm in maximum diameter ruptured into the bilateral pleural spaces and an emergency surgery was performed. The third patient had a thoracoabdominal aneurysm of 60 mm in maximum diameter with a low pulmonary function. In all 3 cases, a perfusion cannula was inserted in the femoral artery and a drainage cannula was placed in the right atrium through the femoral vein. In the first case, an additional perfusion cannula was inserted into the axillary artery in order to secure the cerebral flow even at the time of intraoperative massive bleeding from the aneurysm. In all 3 cases, the approach for aneurysm was through spiral incision and aneurysms were replaced by graft inclusion technique. All 3 patients had an uneventful postoperative course and are doing well. In surgical treatment of thoracic and thoracoabdominal aneurysm, usefulness of partial cardiopulmonary bypass using right atrial drainage was discussed.

Aged↗

PubMed1993

[Surgical treatment of ruptured sinus of Valsalva aneurysm].

We operated on 3 patients with ruptured sinus of Valsalva aneurysm (RSVA). According to the classification by Konno, 2 of them had type I RSVA where aneurysm originated from the right coronary sinus rupturing into the right ventricle, and another type IV where it arose from the non-coronary sinus draining into the right atrium. Both of the 2 with type I RSVA had accompanied ventricular septal defect (VSD) of Kirklin type I. One of them had infective endocarditis with vegetations clinging to the aortic valve, the pulmonary valve and the right ventricular wall adjacent to VSD, and aortic regurgitation of grade II consequently occurred. In this patient, the aortic cusps and the wall of sinus of Valsalva aneurysm were taken out with vegetations. The defect of sinus and VSD were closed with one large patch and a 25 mm SJM aortic valve was implanted using the patch as a part of annulus. The other patient with type I RSVA received a direct closure of defect of Valsalva sinus and VSD. Another patient with type IV RSVA underwent a direct closure of right atrial wall where aneurysm protruded. All 3 patients are doing well without shunt and aortic regurgitation. In this paper, diagnosis, surgical treatment and outcome of RSVA were reviewed.

Adult↗

PubMed1993

[Surgical treatment of left atrial myxoma with concomitant acquired heart disease].

Among 21 patients with left atrial myxoma treated during the past 11 years in our institute, 3 patients had associated acquired heart disease which required concomitant cardiac surgery. Two patients had atherosclerotic coronary arterial disease, and underwent single coronary artery bypass grafting (CABG) and 4 CABGs in addition to removal of myxoma, respectively. Both of them received CABGs after removal of myxoma, because the intraoperative heart protection using retrograde coronary perfusion could afford the situation. Another patient had a huge left atrial myxoma associated with mitral and tricuspid regurgitation. She suffered from sudden heart failure caused by tumor obstruction of blood flow across the mitral valve, and an emergency surgery was performed. She underwent mitral valve replacement for annular dilatation with prolapse of both leaflets and tricuspid annuloplasty for annular dilatation, in addition to removal of myxoma. All of these 3 patients went a good postoperative course and are doing well now with no local recurrence. In this paper, preoperative and intraoperative evaluation, and surgical treatment of associated heart disease with left atrial myxoma were discussed.

Aged↗

PubMed1992

Use of cytosolic metabolite patterns to estimate free magnesium in normoxic myocardium.

Cytosolic free magnesium (Mgf) is considered relatively constant. To test this concept, Mgf was estimated during hyperkalemic ventricular akinesis, normal and maximum adrenergic stimulation, and sulfate loading of the normoxic perfused guinea-pig heart. The Mgf estimates utilized a new sliding scale derived from the Mg(2+)-dependence of glyceraldehyde-3-phosphate dehydrogenase/phosphoglycerate kinase (GAPDH/PGK). The pseudo constant K'GAPDH.K'PGK was measured as ([creatine phosphate][3-phosphoglycerate][lactate]KLDH)/([creatine][Pi] [glyceraldehyde 3-phosphate][pyruvate]KCK), which varied with magnesium due to KCK (CK, LDH = creatine kinase, lactate dehydrogenase). However, the correct magnesium dependencies of the true constants KGAPDH.KPGK and KCK were taken from the literature. The [Mg2+] at which pseudo K'GAPDH.K'PGK equalled true KGAPDH.KPGK was the best estimate of Mgf.Mgf fell to approximately 0.13 mM in hyperkalemic arrest from a control of approximately 0.6 mM, rising to approximately 0.85 mM only during maximum adrenergic stress. Mgf increased further to approximately 1.3 mM during sulfate loading which induced ATP catabolism. Mgf and ATP were reciprocally related. Thus; (1) myocardial free [Mg2+] judged from GADPH/PGK mass-action relations changed appreciably only under extreme physiological states; (2) ATP was a major chelator of Mg2+ in perfused myocardium, i.e., acute ATP pool size reduction may be associated with increments in Mgf.

Aconitate Hydratase↗

PubMed1992

Severe hypoxia due to ventilation-perfusion mismatch caused by aortic arch aneurysm.

We report a very rare case of hugh aortic arch aneurysm associated with aortic restenosis, which caused severe hypoxia due to ventilation-perfusion mismatch by compression of the left main bronchus and the right pulmonary artery. Aortic arch replacement was performed under circulatory arrest and deep hypothermia in addition to aortic valve replacement as a redo operation, and consequently such hypoxia was relieved.

Adult↗

PubMed1992

[Efficacy of nicorandil on myocardial protection during coronary artery bypass grafting--a comparison with diltiazem].

Diltiazem (DTZ), a calcium slow channel blocker, is estimated to be highly effective for myocardial protection and the prevention of perioperative coronary spasms (PCS). However, the use of high doses of DTZ sometimes results in difficulty in coming off cardiopulmonary bypass due to negative chronotropic activity. Nicorandil (NCD) has remarkable coronary vasodilating effect but possesses little negative chronotropic activity. The purpose of this study was to compare NCD with DTZ with respect to effect on myocardial protection during coronary artery bypass grafting (CABG). As parameters, excess lactate (delta XL), redox potential (delta Eh), left and right ventricular stroke work indices (LVSWI, RVSWI), cardiac index (C.I.), systemic vascular resistance index (SVRI.), myocardial isoenzymes (CK-MB, LDH1), number of PCS and recovery time of chronotropic action were used. delta XL, delta Eh, LVSWI, RVSWI, C.I., SVRI, CK-MB, LDH1 were measured at 0, 1, 3, 6, 9, 18 and 24 hours after the removal of aortic cross clamping. The degree of chronotropic action was evaluated by the length of the recovery time to self beat or normal sinus rhythm after the removal of aortic cross clamping. Forty patients who underwent CABG with retrograde cold blood cardioplegia between Dec. 1989 and May 1991 were divided into the NCD group (n = 20), in which 1.1 micrograms/kg/min NCD was continuously administered from the beginning of the operation and the DTZ group (n = 20), in which the initial St. Thomas cardioplegia containing 5 mg/L and subsequent cold blood cardioplegia solution contained DTZ 3.5 mg/L, for a total DTZ dose of less than 10 mg.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardioplegic Solutions↗

PubMed1992

[Ischemic cardiomyopathy associated with ischemic mitral regurgitation--a case report of successful repair].

We experienced a case of 62-year-old man with ischemic cardiomyopathy and mitral regurgitation. He had a heart failure of New York Heart Association class IV together with unstable angina. His further examination showed an enlarged left ventricle with markedly reduced ejection fraction (12.9%) and ischemic mitral regurgitation of grade III associated with 3-vessel disease. He underwent three coronary artery bypass graftings and mitral annuloplasty by a modification of Kay's method. He showed a remarkable improvement of heart failure and cardiac function together with a disappearance of mitral regurgitation. He discharged from hospital in NYHA class II on the 50th postoperative day and lives an almost normal life now. Operative indication and management of ischemic cardiomyopathy and mitral regurgitation were discussed.

Coronary Artery Bypass↗

PubMed1992

[Surgical treatment of primary cardiac tumors].

Twenty patients with primary cardiac tumors were operated on during the past ten years. The age of 15 female and 5 male patients ranged from 17 to 73 years. Eighteen patients had myxomas, 16 of which located in the left atrium and 2 in the right atrium. Systemic embolism occurred in 8 patients, subsequently caused cerebral infarction in 4, ischemia of extremities in 2, myocardial infarction in 1 and pulmonary infarction in 1. Emergency operation was performed in 5 patients because of severe congestive heart failure. In all cases, removal of myxoma was performed together with the excision of the wall to which the pedicle attached with the use of cardiopulmonary bypass. One patient with pulmonary infarction underwent resection of the infarcted lung simultaneously. Only one patient with severe heart failure died of pulmonary insufficiency one month after the operation. Another patient with cerebral infarction underwent clipping of cerebral aneurysm which appeared later in the infarcted area. The 17 patients including the latter patient showed a good recovery and no local recurrence during the follow-up period of 1 to 120 months. Two patients had malignant tumors, which were malignant fibrous histiocytoma of the left atrium and leiomyosarcoma of the pulmonary artery, respectively. Both of these rare tumors were resected noncuratively and led to the death because of their local recurrence with distant metastasis, though they received adjuvant chemotherapy. The symptoms, complications, diagnoses, surgical treatment and outcome of the primary cardiac tumors are reviewed in this study.

Adolescent↗

PubMed1992

[Coronary artery bypass surgery in patients with severely impaired left ventricular function].

The efficacy and problem of coronary artery bypass grafting (CABG) in patients with severely impaired left ventricular function (left ventricular ejection fraction < or = 30%) were assessed in 27 patients of whom 17 (group 1) underwent emergent CABG and 10 (group 2) elective between Jan 1984 to Aug 1990. As a whole, history of myocardial infarction (24/27, 88.9%), large left ventricular volume with reduced ejection fraction (LVEDVI 126.08 +/- 25.91 ml/m2, LVESVI 93.04 +/- 21.02 ml/m2, LVEF 25.04 +/- 4.75%) and multiple vessel disease with at least one vessel total occlusion (20/27, 74.1%) were characteristically seen in these patients. The patients of group 1 were significantly older (mean 66.12 +/- 5.68 vs 57.10 +/- 8.08, p < 0.01) and needed more frequent preoperative support with IABP (17/17 vs 4/10, p < 0.01). Using Thallium-201 scintigraphy, in 10 patients of group 1 and 9 of group 2, myocardial viability in the proposed bypass area was evaluated before operations. Average 2.37 +/- 0.79 grafts were placed and continuous retrograde cold blood cardioplegia via the coronary sinus was employed for myocardial protection. Two mitral annuloplasty (MAP) for ischemic mitral regurgitation and 2 cryoablation for the treatment of ventricular tachycardia were performed concomitantly. Operative mortality was 47.1% in group 1 and none in group 2 (p < 0.05). Two cases of MAP died, but two cases of cryoablation survived. Postoperative LVEF was improved significantly only in group 2 (p < 0.05), but during the follow-up period of 7 months to 6 years, all 19 survivors expect one remains with NYHA class I or II.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1992

[Postoperative conduction disturbances in patients with retrograde continuous cold blood cardioplegia].

Two hundred twenty-seven patients who underwent open heart surgery with retrograde continuous cold blood cardioplegia (RC-CBCP) were investigated to manifest the incidence of postoperative conduction disturbances (CD) and to determine factors related to the occurrence of CD. The incidence of CD in patients with RC-CBCP was 16.7%, which was lower than that (24.4%) in 41 patients with antegrade continuous cold blood cardioplegia. In addition, the CD resolved by the time of hospital discharge in 65% of the patients. There were no patients with new complete atrioventricular block requiring a pacemaker. The development of postoperative CD was related to topical cooling with slushed ice and lower myocardial temperature of the left ventricle, but not to kinds of diseases, duration of aortic cross-clamp, or the distribution of RC-CBCP evaluated from myocardial temperature at the end of initial infusion of cold cardioplegic solution. Furthermore, terminal warm blood cardioplegia reduced the occurrence of CD. We conclude that the occurrence of CD in patients with RC-CBCP is lower than that in patients with antegrade cardioplegia, and is most related to local hypothermia with slushed ice. This suggests that the most likely mechanism for the development of CD would be ischemic or reperfusion injury to the specialized conduction system with the disturbance of microcirculation because of rouleaux formation in CBCP at very low myocardial temperature.

Aged↗

PubMed1992

[Surgical treatment of native valve endocarditis].

Twenty eight patients with native valve endocarditis (NVE) were subjected to this study. Thirteen patients underwent an operation at the chronic phase, and 15 patients at the active phase. One of the 13 patients at the chronic phase died of cardiac rupture due to myocardial infarction which had occurred preoperatively, and one of 10 patients at active phase without annular infection died of rupture of mycotic cerebral aneurysm early postoperatively. Among 5 patients at the active phase with annular infection, prosthetic valve endocarditis occurred in one patient 1.5 months after supraannular aortic valve replacement, and the second operation with a translocation technique was needed. This patient was lost from low output syndrome. Another patient in this group, who underwent a translocation technique because of mycotic annular abscess, died of intestinal infarction late postoperatively. The other 24 patients went a good postoperative course. Five patients with annular infection at the active phase had a shorter duration from the infectious onset to operation (20 days to 2 months, average 38 days), and the causative microorganisms were streptococcus faecalis, staphylococcus epidermidis and gram-negative coccus. One patient, who died of mycotic cerebral aneurysmal rupture, had candida albicans as a causative microorganism. For patients with NVE, an early aggressive operation is essential before infection extends to the annulus or to other vital organs, especially when these microorganisms are identified.

Adult↗