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Biomedical subjects

K Arakaki

Publications and source records attributed to K Arakaki.

15 recordsLinked to original sources
PubMed2004

[Spinal cord protection during thoracoabdominal aortic aneurysm repair; efficacy of distal aortic perfusion and segmental aortic clamping].

Despite improvement in adjuncts for thoracoabdominal aortic aneurysms (TAAA) repairs, many devastating complications remains after the surgery. Our experience with these aneurysms has been reviewed in order to identify those methods at risk of major morbidity, as well as which further improvements required. During last 16 years, 53 consecutive patients were operated on TAAA. The mean age was 58 years. Twenty patients had dissecting aneurysms and 13 patients had had prior aortic surgery. A femoro-femoral bypass was used to maintain distal aortic perfusion in most patients. Reimplantation of intercostal or lumbar arteries under the multi-segmental aortic clamping is consistent in our technique. Motor evoked potentials (MEP) were measured to monitor spinal cord protection since 2000. The hospital mortality was 9.4% (5/53), 22.2% (2/9) for emergency operation and 15.4% (2/13) for patients with prior aortic surgery. The mortality for the first and elective operations was 3.2% (1/31). No any neurologic dysfunction was observed in all patients including the hospital deaths. In view of clinical results, our adjuncts and techniques are useful for prevention of spinal cord ischemia during the TAAA surgery.

Adult↗
PubMed2003

Blood distribution to the anterior spinal artery from each segment of intercostal and lumbar arteries.

AIM: Prevention of paraplegia, a serious complication of surgery for thoracoabdominal aortic aneurysm, has been well documented. However no assured prophylaxis against this complication has yet been found. Spinal ischemia is believed to be the major cause of paraplegia. We conducted an experimental study to define the development of paraplegia with regard to the blood supply to the spinal cord. METHODS: A porcine model was used to evaluate blood distribution to the anterior spinal artery. Colored silastic agent was selectively injected into the intercostal and lumbar arteries, and distribution to the anterior spinal artery was evaluated on 50 animals. The intercostal and lumbar arteries were ligated in the segments where the blood supply to the anterior spinal artery would be interrupted. Whether or not paraplegia developed was checked 2 days later. RESULTS: Colored silastic agent arrived at the anterior spinal artery from all segments of the 8th intercostal to 4th lumbar arteries. Two of 9 pigs (22.2%) that underwent ligation of the segments from the 9th intercostal to 2(nd) lumbar artery suffered paraplegia. In 3 non-paraplegic pigs, colored silastic agent injected into the preserved arteries was found to have covered a wider range. CONCLUSION: All the intercostal and lumbar arteries supplied blood to the anterior spinal artery. When large segments of intercostal and lumbar arteries were ligated, the blood flow from the preserved segments acquired increased dominance. The possibility exists that any intercostal and lumbar artery can supply blood to the spinal cord and become collateral circulation to the anterior spinal artery.

Animals↗
PubMed2002

[Impact of multi-segmental aortic clamping and distal aortic perfusion on the prevention of postoperative paraplegia during thoracoabdominal aortic graft replacement].

OBJECTIVE: We present the impact of multisegmental aortic clamping under distal aortic perfusion and segmental artery reimplantation on the prevention of postoperative paraplegia during thoracoabdominal aortic graft replacement. PATIENTS: During the last 14 years in 47 patients (age range: 22 to 82 years; average: 57,9 +/- 13,2 years; 16 females and 31 males) with thoracoabdominal aortic aneurysm a graft replacement was performed with adjuncts of normothermic partial bypass and multisegmental aortic clamping. As many patent segmental arteries as possible were reimplanted. RESULTS: Five patients died during hospitalization, for an in-hospital mortality rate of 10,6 %. In the elective patients (n = 40), the hospital mortality rate was 7,5 %. The average number of segmental aortic clampings per patient was 2,83 +/- 1,19 times. In 39 patients (82,9 %), 117 segmental arteries were reimplanted or preserved by beveled anastomosis. Eighty-three out of 117 segmental arteries (70,9 %) were located between TH9 and L2. Postoperative paraplegia/paraparesis did not occur in any patient. CONCLUSION: In view of our results reimplantation of as many segmental arteries as possible under multisegmental aortic clamping with adequate distal aortic perfusion can be recommended for effective prevention of spinal cord ischemia in TAAA surgery.

Adult↗
PubMed2001

One-stage operation for descending thoracic aortic aneurysm and left lung cancer: a case report.

We performed concomitant graft replacement for descending thoracic aortic aneurysm and pulmonary resection for squamous cell carcinoma of the left upper lobe in a 79-year-old man. The tumor reached the parietal pleura. No distance metastasis was found, and the tumor was diagnosed preoperatively as a stage IIB (N0, M0, T3) tumor. The descending thoracic aortic aneurysm was saccular, with greatest diameter being 55 mm, and extending from TH5 to TH8. A left upper lobectomy was performed, and after irrigation with a large volume of saline diluted with povidone iodine, graft replacement for the aortic aneurysm was performed under femoro-femoral partial bypass. To prevent postoperative graft infection, the greater omentum was dissected and placed over the resected pulmonary hilum and the graft. The patient's postoperative course was uneventful. There was no sign of infection, and the patient was discharged 1 month after surgery. Artificial graft wrapping with the greater omentum was useful for the prevention of the postoperative graft infection in this case of surgical treatment of lung cancer and descending thoracic aortic aneurysm.

Aged↗
PubMed2001

Management of the heart rate during coronary artery bypass grafting on the beating heart: newly devised methods of decreasing heart rate--a preliminary report-.

BACKGROUND: To develop new methods for achieving bradycardia, we studied the feasibility of producing transient, reversible bradycardia with atrial stimulation and cooling of the sinoatrial node. METHODS: In an animal study, the atrium was stimulated electrically during the refractory period of the atrioventricular node. Alternatively, an area of the sinoatrial node was cooled regionally. The two methods were also performed in combination. In a clinical study, atrial stimulation was applied in seven consecutive patients who underwent coronary artery bypass grafting (CABG). RESULTS: In the animal study, atrial stimulation was effective only when 2 mg/kg of diltiazem was administered. Such atrial stimulation decreased heart rate (beats/minute) from 95.8+/-16.9 to 64.2+/-20.0 (the average reduction from the control value 66.1+/-10.3%). Cooling the sinoatrial node decreased heart rate, and was effective with or without administration of diltiazem. Heart rate was decreased from 156.6 31.7 to 110.7+/-21.7 (average reduction from control value 71.3+/-9.2%) before using diltiazem and from 102.0+/-11.9 to 63.5+/-13.9 (average reduction from control value 62.0+/-10.4%) after administration of diltiazem. By combining the two methods, heart rate was decreased from 102.0+/-12.3 to 44.6+/-9.1 (average reduction from control value 43.5+/-6.3%). In our clinical study, the atrial stimulation method was effective. CONCLUSION: Atrial stimulation or regional cooling of the sinoatrial node slowed the heart rate. By combining the two methods, the heart rate was slowed to 40. Clinically, atrial stimulation was effective in CABG patients.

Aged↗
PubMed1999

A new devised skirted elephant trunk technique.

A simple and effective new elephant trunk technique was devised and applied to two patients with a successful result. In advance before the operation, an arch graft with a skirted elephant trunk was made. This was done by inserting a smaller, 22 mm diameter sized graft into the arch graft at the distal end and suturing it so as to leave a skirt extending over the smaller graft. This configuration facilitates the distal anastomosis and effectively shortens anastomotic time.

Adult↗
PubMed1999

Two-stage operation for multiple aneurysms of the thoracic aorta, abdominal aorta, and left common iliac artery in an octogenarian.

Multiple aortic aneurysms are well described in the surgical literature. However, there are many problems related to surgical treatment of elderly patients with such aneurysms. This report presents the case, an octogenarian with multiple aortic aneurysms that were successfully treated by graft replacement. An 82-year-old man with a descending aortic aneurysm was referred to our institution for surgery. In addition to the previously diagnosed aneurysm, computed tomography and aortography showed an abdominal aortic aneurysm and a left common iliac aneurysm. Since the patient was an elderly man with chronic obstructive pulmonary disease, a two-stage operation was performed. The abdominal aortic aneurysm and left common iliac aneurysm were resected first due to the risk of thromboembolism from the abdominal aortic aneurysm during surgery involving replacement of the descending aorta under femoro-femoral (F-F) bypass. Fifty-two days after the first operation, a second operation was performed to repair the descending aortic aneurysm. The postoperative course was uneventful. Angiography after the operation showed satisfactory replacement of the multiple aortic aneurysms. The patient was discharged 25 days after the second operation.

Aged↗
PubMed1999

Sutureless technique for subacute left ventricular free wall rupture: A case report of an 85-year-old.

This case was an 85-year-old female who developed left ventricular free wall rupture (LVFWR) of the anterior wall 13 days after an acute myocardial infarction. She was further complicated with an ascending aortic aneurysm and severe aortic regurgitation. The wall was repaired using a sutureless technique with an autologous pericardial patch and GRF glue without cardiopulmonary bypass. Although the complication of a left ventricular aneurysm was seen, the postoperative course was uneventful. Nevertheless, she is doing well 9 months after surgery.

Aged↗
PubMed1998

Successful treatment of bilateral deep femoral aneurysms and multiple iliac aneurysms associated with severe aortic valve disease: report of a case.

We report herein the case of a patient in whom aneurysms of the bilateral deep femoral arteries (DFA) and multiple iliac aneurysms associated with severe aortic valve disease were successfully treated by a two-staged operation. The patient was a 74-year-old man who had dense calcification of the ascending aorta and aortic arch. Prior to aortic valve replacement (AVR), the aneurysms of the DFA and internal iliac arteries were resected. The terminal end of the abdominal aorta and bilateral common iliac arteries were then reconstructed with a Y graft to be used as a possible alternative arterial input route in place of the ascending aorta for extracorporeal circulation during the AVR. The inferior mesenteric artery (IMA) was well developed, and the external iliac arteries and their branches were preserved at aneurysmectomy. Postoperatively, there was no ischemia of the pelvic organs or the hip muscles. The AVR was subsequently performed 5 weeks after the first operation, and the patient was discharged after an uneventful postoperative course.

Aged↗
PubMed1998

A ruptured syphilitic descending thoracic aortic aneurysm. The characteristic findings on computed tomography for the etiological diagnosis of aneurysm.

We report the case of a 72-year-old man with a ruptured syphilitic descending thoracic aneurysm who underwent an emergency operation and successful graft replacement. Preoperative physical examination showed a pulsative mass on the left back. Preoperative computed tomography showed bone destruction in the TH6 to TH10 thoracic vertebrae and ribs and penetration (or rupture) of the aneurysm into the subcutaneous tissue. During the period of preoperative evaluations, free wall rupture of the aneurysm occurred and emergency operation for graft replacement was performed. The microscopical examination of the aneurysmal wall revealed the syphilitic changes. In literature, the vertebral destruction by atherosclerotic aneurysm is usually located at the TH12 to L3 of vertebral bodies. From the findings of this patient and a study of existing literature, we concluded that the finding of vertebral bone beyond TH12 to L3 region on CT examination of the aneurysm could be a etiological characteristic finding for syphilitic aortic aneurysm.

Aged↗
PubMed1997

High prevalence of GAD65 (and IA-2) antibodies in Japanese IDDM patients by a new immunoprecipitation assay based on recombinant human GAD65.

Marked differences have been reported in the prevalence of glutamic acid decarboxylase (GAD) antibodies between Caucasian (63-84%) and Japanese (30-50%) or Asian (5-50%) IDDM patients. Using a new immunoprecipitation assay based on 125I-labelled recombinant human GAD65 we have reassessed prevalence of GAD65 antibodies in Japanese patients. We also assessed prevalence of IA-2 antibodies. GAD65 antibodies were detected in 83.3% of sera taken within 1 year of onset, comparable to the prevalence reported in Caucasian patients. Positivity decreased to 66.7% after 2 to 3 years and to 54.3% after 3 years from onset, still higher than previously reported Asian prevalence. Except in one patient, high antibody levels persisted chronically, up to 12 years. There was no difference in the prevalence of GAD65 antibodies between Japanese IDDM patients with and without autoimmune thyroid disease (AITD). IA-2 antibodies were detected in 64.7% of sera taken within 1 year of onset. Prevalence of IA-2 antibodies was lower than that of GAD65 antibodies. The difference in positivity in Asian IDDM patients between present and previous reports arose from the sensitivity of our assay for GAD65 antibodies. Additionally, the patients we studied had classic IDDM with a well-defined onset. We conclude that prevalence of GAD65 antibodies in Japanese IDDM patients is comparable to that in Western studies. There was no relationship of GAD65 antibody positivity to coexistence of AITD. Our results suggest that autoimmunity is the most significant cause of Japanese IDDM.

Adolescent↗
PubMed1996

In situ right internal thoracic artery graft via transverse sinus for revascularization of posterolateral wall: early results in 116 cases.

The in situ right internal thoracic artery graft brought through the transverse sinus was used to revascularize the posterolateral wall in 116 patients. Its advantages were assessed retrospectively. The graft was anastomosed to the circumflex marginal branch in 70 patients (60%) or to the posterolateral branch in 41 patients (35%). One patient died (mortality rate 0.9%). Perioperative myocardial infarction occurred outside the territory of the right internal thoracic artery graft in 10 patients, four of whom required mechanical support for hemodynamic deterioration. Postoperative early angiography in 114 patients found the graft to be patent in 97.4%. The ratio of the diameter of the right internal thoracic artery to that of the recipient marginal branch was 0.94 +/- 0.18 (n = 69), and that to the posterolateral branch was 0.88 +/- 0.18 (n = 37) (not significantly different). Results of a postoperative stress test were abnormal in one patient (1/96 tested patients). This retrospective study suggests that the right internal thoracic artery brought through the transverse sinus to revascularize the posterolateral wall provided excellent early patency and good clinical results, even to the most distally located branches. This continues to be our procedure of choice for patients with multivessel coronary disease.

Adolescent↗
PubMed1996

[Coronary artery bypass surgery in patients over 80 years].

Coronary artery bypass grafting (CABG) was being performed with increased frequency in elderly patients. However, the results of operations in patients over the age of 80 years have not been previously reported in Japan. Between May 1988 and September 1994, we have performed CABG in 28 patients over the 80 years of age (group A: mean 82.2). These patients were compared with 240 patients in 60s (group B: mean 65.0). Mean New York Association functional class (NYHA) was significantly higher in group A (p < 0.01). Left main trunk stenosis was more frequent in group A patients (p < 0.01), while the number of diseased vessels did not differ. Preoperative use of an intra-aortic balloon pump (29%) and emergency operation (54%) were more frequent in group A patients (p < 0.01). There was no significant difference in the number of grafts per patient between the groups (2.93 for group A versus 2.93 for group B), but the internal mammary artery was used more frequently in group B patients (99% versus 39%, p < 0.01). In group A, the major complicatines were stroke, cardiac tamponade, reoperatin for bleeding and respiratory failure in 1 patient each (3.6%). The hospital mortality did not differ between the groups (0% for group A and 2.9% for group B). In group A, at mean follow-up of 16.3 months, 25 patients (89%) are alive and no patient had recurrent angina. We conclude that CABG in patients over 80 years of age can be performed with low mortality and significant symptomatic benefit. Patients should not be denied CABG because of age alone.

Age Factors↗