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Dive into the research topics where Naozumi Saiki is active.

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Featured researches published by Naozumi Saiki.


Surgery Today | 2011

Hybrid procedures combining conventional and thoracic endovascular aortic repair for thoracic aortic aneurysms

Yukio Obitsu; Nobusato Koizumi; Satoshi Takahashi; Yasunori Iida; Naozumi Saiki; Satoshi Kawaguchi; Hiroshi Shigematsu

PurposeTo minimize surgical invasiveness for extensive aortic aneurysms and expand the indications for thoracic endovascular aortic repair (TEVAR), we evaluated outcomes of hybrid procedures combining conventional surgical aortic repair and TEVAR for thoracic aortic aneurysms.MethodsThe following hybrid procedures were performed: second-stage TEVAR after total aortic arch replacement using the elephant trunk as the landing zone in 17 patients; and for multiple aortic aneurysms, vascular graft replacement and TEVAR in 13 patients, vascular graft replacement and TEVAR with bypass in 2 patients, and TEVAR with bypass in 23 patients.ResultsThere were three (5.3%) hospital deaths, from serious complications including stroke, paraplegia, paraparesis, and aspiration pneumonia; and eight late deaths. There was only one aneurysm-related death, of a patient who underwent emergency surgery for an esophageal fistula resulting from enlargement of a residual false lumen of a thoracoabdominal aorta after second-stage TEVAR.ConclusionHybrid procedures minimize surgical invasiveness in thoracic aortic aneurysm repair, but further evaluation of a larger number of patients is necessary.


The Japanese Journal of Thoracic and Cardiovascular Surgery | 2010

Long-term results of second-stage thoracic endovascular aortic repair following total aortic arch replacement

Yukio Obitsu; Nobusato Koizumi; Yasunori Iida; Toru Iwahashi; Naozumi Saiki; Hisahito Takae; Satoshi Kawaguchi; Hiroshi Shigematsu

PurposeWe investigated the surgical results of secondary thoracic endovascular aneurysm repair (TEVAR) using the elephant trunk graft after total aortic arch replacement (TAR) for extensive thoracic aortic lesions.MethodsThe subjects comprised 16 patients who underwent TEVAR as a staged procedure following TAR at our institution between 1997 and 2007. Long-term results were retrospectively surveyed (mean observation period 68.4 months). We performed TEVAR with the elephant trunk graft as a proximal landing zone for the descending thoracic repair, the mean duration between TAR and TEVAR was 4.7 weeks for the staged operations and 18.3 months for the nonstaged operations.ResultsEarly results were good in all cases, with no deaths and no noteworthy complications. For the seven patients without dissection, long-term results were also good. Among the nine patients with dissection, the false lumen in the thoracoabdominal area enlarged in three during follow-up. We performed thoracoabdominal repair in two, but one died of an aneurysm-esophageal fistula. There was only one long-term aneurysm-related death.ConclusionSecond-stage TEVAR using the elephant trunk graft after TAR allows less invasive surgery for extensive aortic lesions and achieves good long-term results. However, enlargement of the false lumen was a long-term concern in patients with aortic dissection, and careful follow-up is essential.


Annals of Vascular Diseases | 2011

Skin perfusion pressure measurement to assess improvement in peripheral circulation after arterial reconstruction for critical limb ischemia.

Atsuko Onozuka; Yukio Obitsu; Hiroyoshi Komai; Nobusato Koizumi; Naozumi Saiki; Hiroshi Shigematsu

AIM To assess the utility of skin perfusion pressure (SPP) measurement in evaluating the outcome of vascular constructions for critical limb ischemia (CLI) patients. METHODS We retrospectively studied 19 lower limbs in 18 patients who underwent arterial reconstruction for CLI from whom SPP measurements had been obtained pre- and postoperatively between 2008 and 2010. Six limbs whose ulcers had healed postoperatively were classified into group H, 7 limbs whose ulcers had not healed into group U, and 6 limbs without ulcers into group N. SPP values were compared among these groups. RESULTS The preoperative SPP values in all groups were <30 mmHg, without significant differences among the groups. The SPP values in groups H and N significantly improved after operation, and those in group U were significantly lower than those in the other groups. CONCLUSIONS SPP measurement before and after arterial reconstruction is useful to assess improvement in tissue circulation and to predict the likelihood of wound healing. An SPP value ≥30 mmHg was considered necessary for wound healing, supporting the findings of the few reports in the literature on the usefulness of SPP for assessing vascular reconstruction effects on ulcer wound healing.


Journal of Cardiothoracic Surgery | 2010

Surgical repair for aortic dissection accompanying a right-sided aortic arch

Yukio Obitsu; Nobusato Koizumi; Toru Iwahashi; Naozumi Saiki; Hiroshi Shigematsu

Aortic anomaly in which a right-sided aortic arch associated with Kommerells diverticulum and aberrant left subclavian artery is rare. The present report describes a patient with type-B aortic dissection accompanying aortic anomalies consisting of right-sided aortic arch and the left common carotid and left subclavian artery arising from Kommerells diverticulum. As dissecting aortic aneurysm diameter increased rapidly, Single-stage surgical repair of extensive thoracic aorta was performed through median sternotomy and right posterolateral fifth intercostal thoracotomy, yielding favorable results. Our surgical procedures are discussed.


Annals of Vascular Diseases | 2008

Hybrid Treatment of Multiple Aortic Aneurysms by Combined Conventional Surgery and Endovascular Aortic Repair

Yukio Obitsu; Nobusato Koizumi; Yasunori Iida; Kazuhiro Satou; Hisahito Takae; Naozumi Saiki; Satoshi Kawaguchi; Hiroshi Shigematsu

PURPOSE We evaluated the operative results of our treatment for multiple aortic aneurysms by means of a hybrid procedure consisting of a combination of conventional surgical maneuvers and simultaneous or sequential endovascular aortic repair (EVAR). MATERIALS AND METHODS From August 1998 to April 2007, a total of 15 patients, 11 men and 4 women, ranging in age from 62 to 78 years, were treated with hybrid procedures for multiple aortic aneurysms. The pathology of these patients were, atherosclerotic aneurysm in 12 patients, atherosclerotic aneurysm associated with chronic dissection in 2 and type III chronic dissection in 1 patient. The distribution of aneurysmal locations were as follows: 5 patients had aneurysms at the arch and descending aorta, 1 had at the arch and thoracoabdominal aorta, 6 at the descending and abdominal aorta. Two patients with chronic dissection had simultaneous abdominal aortic aneurysms. In all except 1 of the 7 patients who had abdominal aortic aneurysm, we performed abdominal aneurysmectomy and EVAR simultaneously. In 7 patients, EVAR was performed sequentially after graft replacement surgery. In 2 patients, EVAR was the initial procedure followed by conventional surgery. The mean interval between first and second stage procedures was approximately 4 months. RESULTS One patients died of methicillin resistant Staphylococcus aureus pneumonia 3 months after the simultaneous procedure, all others were discharged and survive. In particular, no major EVAR linked complication was observed in the follow-up period (range 3 to 91 months, mean 46 months). CONCLUSION The hybrid procedure for the treatment of multiple aortic aneurysmal disease is less invasive compared to conventional staged surgery and the outcome in terms of mortality and morbidity in hospital as well as long-term follow-up are satisfactory.


Journal of Vascular Surgery | 2011

Staged hybrid repair using telescoped stent graft fixation for aortic arch and descending aortic aneurysms

Nobusato Koizumi; Yukio Obitsu; Naozumi Saiki; Yasunori Iida; Satoshi Kawaguchi; Hiroshi Shigematsu

Staged repair of extensive thoracic aortic aneurysms is complicated, with a high incidence of interval rupture between stages. We describe the systematic staged hybrid procedure of a previous endovascular repair of a descending aortic aneurysm and open surgical repair of an aortic arch aneurysm. In the second-stage arch repair, the stent graft was easily retracted and fixed, without dissection, around the aortic arch aneurysm distal side. Extensive thoracic aortic aneurysms were managed without interim rupture or neurologic deficits. This approach avoided the potential for interim rupture because recovery from the first-stage endovascular repair was shorter than that from open repair.


Annals of Vascular Diseases | 2011

Conservative Therapy for Surgically Untreatable Extensive Arteriovenous Malformation from the Lower Extremityto the Pelvis with Secondary Consumptive Coagulopathy

Toru Iwahashi; Naozumi Saiki; Nobusato Koizumi; Toshiya Nishibe; Hitoshi Ogino

We present a woman with surgically untreatable extended arteriovenous malformations (AVM) and consumptive coagulopathy, which had been controlled by conservative compression and anticoagulation therapies for 17 years. At age 13, she was diagnosed with extended AVM in the entire left leg and pelvis. At age 16, limited surgical resection of the enlarged superficial vein in the left calf was performed for persistent leg pain. One year later, anticoagulation therapy was performed for massive bleeding from hemorrhoids due to AVM and coagulopathy. Despite its intractability, her condition has been favorably controlled with conservative methods, including compression and anticoagulation therapies.


Journal of Cardiothoracic Surgery | 2010

Long-term result of hybrid procedure for an extensive thoracic aortic aneurysm in Takayasu arteritis: a case report

Yukio Obitsu; Nobusato Koizumi; Naozumi Saiki; Satoshi Kawaguchi; Hiroshi Shigematsu

We herein present a 60 years old woman with Takayasu arteritis and an extensive thoracic aortic aneurysm who initially underwent a total aortic arch replacement. Then, in the second stage, thoracic endovascular aortic repair was performed using the elephant trunk graft as the proximal landing zone at four weeks after aortic arch repair. The postoperative course was relatively uncomplicated, but a type II endoleak was noted. Currently, about 5 years postoperatively, the slight type II endoleak from intercostal artery persists, but aneurism dilatation has not been noted, so the patient is being followed up.


Vascular and Endovascular Surgery | 2006

Evaluation of thrombogenicity by indium-111 platelet scintigraphy in endografting for abdominal aortic aneurysms.

Taro Shimazaki; Satoshi Kawaguchi; Yoshihiko Yokoi; Susumu Makimura; Naozumi Saiki; Shin Ishimaru

Obstruction of the endograft limb by thrombosis has often been reported and may cause fatal complications such as leg necrosis or myonephropathic metabolic syndrome. The purpose of this study was to evaluate endograft antithrombogenicity by indium-111 platelet scintigraphy. Seventeen patients with abdominal aortic aneurysms were treated by endografting. Thirteen patients were treated with conventional open surgery using an artificial graft. The endograft was constructed from a self-expanding Z-shaped stent and woven polyester fabric. Autologous platelets labeled with indium-111 were injected at 2 weeks postoperatively. At 24 hours and 72 hours postinjection, the ratio of scintillation count of the endograft or graft to that of the native artery was calculated to assess platelet deposition. The normalization ratio was calculated as follows: (scintillation count per pixel of endograft or graft/circumference)/(scintillation count per pixel of the native femoral artery). Platelet factor 4 and beta-thromboglobulin were measured to evaluate the systemic platelets activity at 2 weeks postoperatively. There was no significant difference in platelet counts or labeling efficiency between the groups. The ratio was significantly higher in the endografting group than in the open surgery group at 72 hours postinjection (2.5-0.7 vs 3.9-1.1, P<.001). There was no significant difference in platelet factor 4 and beta-thromboglobulin between the groups. Although there was no difference in systemic platelet activity, endografting was associated with lower antithrombogenicity. It remains unclear whether lower antithrombogenicity causes thromboembolism as a complication of the procedure. The authors recommend the administration of antiplatelet drugs to prevent endograft obstruction in patients with very narrow iliac arteries.


Annals of Vascular Surgery | 2011

Intraoperative Evaluation of Blood Perfusion by Laser-Assisted Indocyanine Green Angiography After ex vivo Vascular Reconstruction of Intrahilar Renal Artery Aneurysm

Toru Iwahashi; Yukio Obitsu; Nobusato Koizumi; Naozumi Saiki; Satoshi Takahashi; Hiroshi Shigematsu

The surgical reconstruction of intrahilar renal artery aneurysms (RAAs) is a difficult surgery because of complex anatomy. We present a case of right intrahilar RAA diagnosed in a 67-year-old man. We performed ex vivo reconstruction using an organ preservation solution to prevent postoperative renal failure. We assessed graft patency and blood perfusion was assessed by laser-assisted indocyanine green angiography using the SPY system after autotransplantation. Postoperative renal insufficiency was not observed. The results demonstrate that ex vivo reconstruction of intrahilar RAAs using an organ preservation solution, and graft patency and blood perfusion evaluation using the SPY system are effective methods for preserving renal function.

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Yukio Obitsu

Tokyo Medical University

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Toru Iwahashi

Tokyo Medical University

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Shin Ishimaru

Tokyo Medical University

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Hisahito Takae

Tokyo Medical University

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Taro Shimazaki

Tokyo Medical University

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