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Dive into the research topics where Kazufumi Miyagi is active.

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Featured researches published by Kazufumi Miyagi.


The Annals of Thoracic Surgery | 2003

Prevention of postoperative paraplegia during thoracoabdominal aortic surgery

Yukio Kuniyoshi; Kageharu Koja; Kazufumi Miyagi; Mituyoshi Shimoji; Tooru Uezu; Katuya Arakaki; Satoshi Yamashiro; Katuhito Mabuni; Shigenobu Senaha; Yoshiyuki Nakasone

BACKGROUND We present data showing the impact of sequential multisegmental aortic clamping accompanied by reimplantation of as many segmental arteries as possible on the prevention of postoperative paraplegia or paraparesis during thoracoabdominal aortic graft replacement. METHODS Since 1987 we have performed graft replacements in 51 individuals undergoing thoracoabdominal aortic surgery using the technique of normothermic partial bypass with sequential multisegmental aortic clamping. The procedure was performed emergently in 10 patients and electively in 41 patients. The patients ranged in age from 22 to 82 years (mean, 57.6 +/- 13.8 years). Indications for surgery included dissecting thoracoabdominal aortic aneurysm (n = 19) and nondissecting thoracoabdominal aortic aneurysm (n = 32). The extent of aneurysm was Crawford type I in 19 patients, type II in 7 patients, type III in 12 patients, and type IV in 13 patients. Along the entire extent of aneurysm to be replaced, we reimplanted as many of the patent segmental arteries as feasible. RESULTS Five patients died during hospitalization, for an in-hospital mortality rate of 9.8%. The number of aortic clampings per patient ranged from one to five (median, three). A total of 124 segmental arteries were reimplanted in 44 (86.3%) of 51 patients. Of the 124 arteries, 90 (72.6%) were distributed between T9 and L2. Postoperative paraplegia or paraparesis did not develop in any of the patients. CONCLUSIONS Our results demonstrate that extensive reimplantation of segmental arteries using sequential multisegmental aortic clamping, accompanied by adequate intraoperative distal aortic perfusion, is effective in preventing spinal cord ischemia.


Asian Cardiovascular and Thoracic Annals | 2005

Graft for Mycotic Thoracic Aortic Aneurysm: Omental Wrapping to Prevent Infection

Yukio Kuniyoshi; Kageharu Koja; Kazufumi Miyagi; Tooru Uezu; Satoshi Yamashiro; Katuya Arakaki

Nine cases of mycotic thoracic aortic aneurysm were treated surgically between July 1995 and March 2003. The aneurysms were located in the ascending aorta in 1 patient, the descending thoracic aorta in 5, and the thoracoabdominal aorta in 3. Preoperatively, 3 patients were in shock due to rupture of the aneurysm. All patients underwent aneurysmectomy and in-situ graft placement. In 5 patients, the graft was covered with a pedicled omental flap to prevent postoperative graft infection. There were 2 hospital deaths: one patient died of multi-organ failure, and the other died from intrathoracic bleeding. After discharge, one patient died from intrathoracic bleeding 3 months after surgery. These 3 patients had not received omental wrapping. Postoperative graft infection did not occur in the 6 surviving patients during a mean follow-up period of 4.0 ± 3.1 years. It was concluded that covering the prosthetic graft with a pedicled omental flap may help prevent postoperative graft infection and improve the surgical results.


Journal of Artificial Organs | 2003

Pannus formation in aortic valve prostheses in the late postoperative period

Yukio Kuniyoshi; Kageharu Koja; Kazufumi Miyagi; Mituyoshi Shimoji; Tooru Uezu; Katuya Arakaki; Satoshi Yamashiro; Katuhito Mabuni; Shigenobu Senaha; Yoshiyuki Nakasone

We present three patients who underwent repeat aortic valve replacement for prosthetic valve dysfunction caused by tissue ingrowth in the late postoperative period. These patients (three women aged 48–51 years, mean 49.3 ± 1.53 years) underwent operations for restriction of prosthetic valve leaflet movement by pannus in the left ventricular outflow tract. The interval from the previous operation ranged from 8.0 to 9.6 years (mean 9.6 ± 2.0 years). The symptoms of the patients were New York Heart Association functional class I, II, and IV in one patient each. Diagnosis was made by cinefluoroscopy in two patients and aortography in one patient. The operative procedures consisted of aortic valve replacement (n = 1) and aortic valve replacement with mitral valve replacement (n = 2). Pannus was found at the left ventricular aspect of the prosthetic valve in all patients. In two patients, the pannus directly restricted movement of the leaflet and also severely narrowed the inflow orifice of the prosthetic valve. In the other patient, the pannus had grown at a distance of 7 mm from the valve and narrowed the left ventricular outflow tract circularly. The postoperative course was uneventful and all three patients were discharged in a good condition. One patient died of pneumonia 8 months after surgery and the other two patients have remained well and have been followed up for one and a half years. In conclusion, there may be a discrepancy between the clinical symptoms and the grade of subvalvular stenosis caused by pannus. Therefore, it is essential for satisfactory operative results that early diagnosis be made by various means.


The Annals of Thoracic Surgery | 1998

Improvement in esophageal varices and liver histology postoperatively in Budd-Chiari syndrome

Yukio Kuniyoshi; Kageharu Koja; Mituru Akasaki; Kazufumi Miyagi; Mituyoshi Shimoji; Manabu Kudaka; Tooru Uezu

BACKGROUND In the past 17 years, 32 patients with Budd-Chiari syndrome were treated by reconstruction of the occluded inferior vena cava and reopening of the hepatic veins under femoro-femoral normothermic extracorporeal partial bypass. The mean follow-up was 8 years (range, 1.5 to 17 years). METHODS To evaluate the benefits of our operative procedure, we compared the preoperative, early postoperative, and late postoperative endoscopic appearance of the esophageal varices and the histologic findings of the liver tissue obtained intraoperatively and at a later date. RESULTS The esophageal varices found preoperatively in 29 patients (90.6%) had disappeared in 7 patients by the time of discharge, and in 2 patients they disappeared 4 to 7 years after surgery. In the remaining 20 patients, the grade of the esophageal varices was reduced markedly. Histologic examination of the liver showed cirrhosis in 22 patients, fibrosis in 9 patients, and severe congestion in 1 patient. Inspection of the liver in the late postoperative period (in 10 patients) showed improvement in centrilobular congestion and no increase in interlobular fibrosis. CONCLUSIONS Gradual and steady improvement of esophageal varices and hepatic fibrosis can be achieved after our operative procedure.


Journal of Vascular Surgery | 2012

Nonsurgical treatment of scalp arteriovenous malformation using a combination of ultrasound-guided thrombin injection and transarterial coil embolization.

Isao Nishijima; Ryo Ikemura; Masuichi Gushiken; Kazufumi Miyagi; Kiyoshi Iha

Scalp arteriovenous malformations are treated by surgical excision in many patients. We report a patient with a scalp arteriovenous malformation who was successfully treated by a combination of ultrasound-guided thrombin injection (UGTI) and transarterial coil embolization. This patient was a 52-year-old man with a subcutaneous mass in the left retroauricular region. An angiogram showed that the mass was a nidus of arteriovenous malformation. We performed UGTI after transarterial coil embolization. No recurrence or complication was reported during 2 years of follow-up. This report describes the advantages of UGTI and the method for complete occlusion of the collateral artery.


Surgery Today | 1998

Successful Treatment of Bilateral Deep Femoral Aneurysms and Multiple Iliac Aneurysms Associated with Severe Aortic Valve Disease: Report of a Case

Yukio Kuniyoshi; Kageharu Koja; Mituru Akasaki; Kazufumi Miyagi; Mituyoshi Shimoji; Manabu Kudaka; Tooru Uezu; Katuya Arakaki; Hitoshi Sakuta; Yoshihiko Kamada

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.


Surgery Today | 2005

Improvement of Liver Function After Surgery for Budd-Chiari Syndrome

Yukio Kuniyoshi; Kageharu Koja; Kazufumi Miyagi; Tooru Uezu; Satoshi Yamashiro; Katsuya Arakaki; Takaaki Nagano; Katsuhito Mabuni; Shigenobu Senaha

PurposeWe evaluated the relationship between liver histology and postoperative improvement of liver function after surgery for Budd-Chiari syndrome (BCS).MethodsOver a period of 23 years, we operated on 46 patients with BCS by reconstructing the occluded inferior vena cava (IVC) and reopening as many occluded hepatic veins as possible. We divided the patients into a liver cirrhosis group (group I, n = 30) and a hepatic fibrosis or liver congestion group (group II, n = 16), and compared the ages, duration of illness, preoperative liver function, changes in liver function, and changes in esophageal varices (EV).ResultsThere were no hospital deaths. In group I the patients were older, and the duration of illness was longer. The group I patients also had a lower thrombotest percentage and a higher serum ammonia. The indocyanine green clearance (ICG) test showed more remarkable improvement in liver function in group II. The rate of disappearance of EV was also higher in group II.ConclusionSurgery during the early stage of BCS is important in improving postoperative liver function.


Asian Cardiovascular and Thoracic Annals | 2004

Type B Dissection Complicated with Subacute Visceral Ischemia

Satoshi Yamashiro; Yukio Kuniyoshi; Kazufumi Miyagi; Toru Uezu; Katsuya Arakaki; Kageharu Koja

A 63-year old man presented with back pain and abdominal pain that worsened after eating. Contrast-enhanced computed tomography revealed type B aortic dissection. Arteriography 20 days after dissection revealed celiac trunk stenosis and the superior mesenteric artery did not arise from the true lumen. Saphenous vein bypass grafting from the right common iliac artery to the superior mesenteric and gastroduodenal arteries was performed. The postoperative course was uneventful and the abdominal symptoms completely disappeared.


European Journal of Cardio-Thoracic Surgery | 2003

Intraoperative transesophageal echocardiographic assessment of myocardial protection in a redo ascending-arch aortic operation

Yukio Kuniyoshi; Kageharu Koja; Kazufumi Miyagi; Manabu Kakinohana

In a redo operation of the ascending aortic arch, transesophageal echocardiography was useful in confirming antegrade infusion flow of cardioplegia solution into the left main coronary artery.


Asian Cardiovascular and Thoracic Annals | 2004

The prevention of nerve injury in aortic arch aneurysmal surgery.

Yukio Kuniyoshi; Kageharu Koja; Kazufumi Miyagi; Tooru Uezu; Satoshi Yamashiro; Katuya Arakaki

In a case of aortic arch aneurysm associated with adhesion to the surrounding structures, we devised an operative technique to avoid nerve injury during the surgical procedure. By preserving the adventitial layer of the aortic arch aneurysm to which the phrenic and recurrent nerves were attached, injury to the nerves was avoided, and the aneurysmectomy was completed with the distal anastomosis being performed intraluminally.

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Kageharu Koja

University of the Ryukyus

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Yukio Kuniyoshi

University of the Ryukyus

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Tooru Uezu

University of the Ryukyus

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Katsuya Arakaki

University of the Ryukyus

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Toru Uezu

University of the Ryukyus

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Katuya Arakaki

University of the Ryukyus

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Manabu Kudaka

University of the Ryukyus

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Mitsuru Akasaki

University of the Ryukyus

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