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Dive into the research topics where Nobuyuki Kaji is active.

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Featured researches published by Nobuyuki Kaji.


Scandinavian Journal of Plastic and Reconstructive Surgery and Hand Surgery | 2009

Experience of sclerotherapy and embolosclerotherapy using ethanolamine oleate for vascular malformations of the head and neck

Nobuyuki Kaji; Masakazu Kurita; Mine Ozaki; Akihiko Takushima; Kiyonori Harii; Mitsunaga Narushima; Shinichi Wakita

Sclerotherapy is effective in the treatment of vascular malformations. However, in lesions with relatively high blood flow, its effect is not always adequate. We therefore developed a three-grade classification of vascular malformations to facilitate the selection of treatments according to vascular flow. We also developed the technique of embolosclerotherapy, in which transarterial embolisation is done before sclerotherapy to control blood flow in the lesion during sclerotherapy. We now have 14 years’ experience with 112 cases of vascular malformations of the head and neck treated with sclerotherapy. Results were evaluated with pretreatment and post-treatment photographs, and reduction of volume was calculated on findings from magnetic resonance imaging. Clinical improvement in 110 cases was graded as excellent in 32 (29%), good in 48 (43%), fair in 19 (17%), and poor in 11 (10%). In 84 cases, mean rate of reduction of volume was 35%. The most common complication was haemolytic haemoglobinuria (n=37, 33%). Our results suggest that this three-grade classification is useful to judge resistance to sclerotherapy and decide on treatment. Our experience indicates that ethanolamine oleate (EO), with or without arterial embolisation, was effective using our classification of vascular dynamics. We consider EO to be equivalent or superior to other sclerosants such as ethanol.


Aesthetic Plastic Surgery | 1998

One-Stage Reconstruction of an Upper Part Defect of the Auricle

Kotaro Yoshimura; Takashi Nakatsuka; Shigeru Ichioka; Nobuyuki Kaji; Kiyonori Harii

Abstract. A one-stage procedure for the reconstruction of a defect of the upper auricle is described. The anterior surface of a carved costal cartilage graft was covered with an anterosuperiorly based skin flap, and the posterior surface was covered by the superficial mastoid fascial flap and a skin graft. This method can be performed easily, without leaving any scar in the hair-bearing area or visible postauricular region, and can be applied to cases in which the condition of the margin scar of an auricular defect is poor.


Journal of Plastic Surgery and Hand Surgery | 2010

Efficacy and evaluation of safety of sclerosants for intramuscular venous malformations: clinical and experimental studies.

Mine Ozaki; Masakazu Kurita; Nobuyuki Kaji; Takashi Fujino; Mitsunaga Narushima; Akihiko Takushima; Kiyonori Harii

Abstract Excision of intramuscular venous malformations may damage intact functional muscles, and sclerotherapy is an alternative way of relieving symptoms. Several sclerosants are available, but selection of the optimal one is controversial. We report our clinical experiences of sclerotherapy, and experimental studies in rats that investigated muscular damage after injection of various sclerosants. For the clinical study, 10 patients with intramuscular venous malformations were reviewed who had been treated by sclerotherapy using ethanolamine oleate. The rate by which the volume reduced was assessed quantitatively using findings from magnetic resonance imaging (MRI). Pain was cured or improved in all cases, and volume reduced on imaging analysis. There were no severe complications such as renal failure or thromboembolism. For the experimental study, 62 Wistar rats were used to investigate the toxicity of sclerosants on the intact-muscle by injecting three types of sclerosants (100% ethanol, 5% ethanolamine oleate, and 1% polidocanol). After the injection of each sclerosant into the anterior tibial muscle, the daily measurement of the circumference of the legs, histological and morphological alterations in the muscles, and maximal isometric tetanic tension, were investigated. Swelling was most prominent with ethanolamine oleate, while destruction and atrophy of the muscle were most prominent after injection of ethanol. In the clinical study, the efficacy of 5% ethanolamine oleate was at least equivalent or possibly superior to that of 100% ethanol. In the experimental study, ethanol had a more detrimental effect on muscles than the other agents. We consider that ethanolamine oleate is the most suitable sclerosant for the treatment of intramuscular venous malformations.


Annals of Plastic Surgery | 1999

Free jejunal patch to reconstruct oral scar contracture following caustic ingestion.

Shigeru Ichioka; Takashi Nakatsuka; Kotaro Yoshimura; Nobuyuki Kaji; Kiyonori Harii

Reconstruction of oral scar contracture is often a challenging problem due to the complex structures and functions of the oral cavity. This report describes the treatment of a patient who sustained extensive oral scar contracture following caustic liquid soda ingestion. Surgical release of the scar contracture formed an S-shaped, thin, long defect that was difficult to cover with a conventional flap or skin graft. A jejunal segment was transferred microsurgically as a patch to reconstruct the defect. It sustained a sufficient oral space to provide full opening of the mouth and good movement of the tongue. A free jejunal flap, used occasionally for reconstruction following oral cancer resection, has significant advantages for restoration of function after release of an oral scar contracture.


Dermatologic Surgery | 2011

Subcutaneous Injection of Normal Saline Prevents Cutaneous Complications of Ethanol Sclerotherapy for Superficial Vascular Lesions: An Experimental Study

Aki Ihara; Masakazu Kurita; Mine Ozaki; Masahide Fujiki; Nobuyuki Kaji; A. Takushima; Kiyonori Harii

BACKGROUND Percutaneous sclerotherapy is an effective therapeutic option for the treatment of venous malformations. Absolute ethanol is used as a sclerotic agent because of its effectiveness but is often avoided for treatment of superficial lesions because of the possible risk of cutaneous necrosis. OBJECTIVE A preclinical experimental study was performed to validate whether the cytotoxic effects of ethanol on surrounding healthy tissues could be diminished with prophylactic subcutaneous injection of normal saline above the vascular lesion immediately after intraluminal injection of ethanol by dilution. METHODS AND MATERIALS The effect of normal saline dilution on cytotoxicity of ethanol to the main cells of the skin (fibroblasts and keratinocytes) were assessed using 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide colorimetric assay. Effects of subcutaneous injection of normal saline immediately after intraluminal ethanol injection were assessed in a newly developed animal experimental model using the rabbit auricular vein. RESULTS Cytotoxic effects of ethanol were decreased by saline dilution in vitro. Subcutaneous injection of normal saline after intraluminal injection of ethanol prevented the cutaneous ulceration observed in all cases without subcutaneous injection of normal saline in our animal model. CONCLUSION Subcutaneous injection of normal saline appears effective for preventing cutaneous complications after ethanol sclerotherapy for superficial vascular lesions. The authors have indicated no significant interest with commercial supporters.


Journal of Plastic Surgery and Hand Surgery | 2012

Detrimental influences of intraluminally-administered sclerotic agents on surrounding tissues and peripheral nerves: An experimental study

Masahide Fujiki; Masakazu Kurita; Mine Ozaki; Hayato Kawakami; Nobuyuki Kaji; Akihiko Takushima; Kiyonori Harii

Abstract The minimally-invasive nature of sclerotherapy makes it one of the first treatment options for venous malformations, although treatment-related complications, such as peripheral nerve paralysis, have been reported in some clinical cases. However, no studies of the aetiology of the detrimental effects of intraluminally-administered sclerotic agents on the surrounding tissues, including the peripheral nerves, have yet been published. This study therefore investigated the influences of intraluminally-administered sclerotic agents on the tissues surrounding the injection site using a newly-developed rat femoral vein model. Using this model, the effects of absolute ethanol, 5% ethanolamine oleate, and 1% polidocanol were compared histologically with those of normal saline controls. Fluorescein isothiocyanate-conjugated agents were administered and the leakage of sclerotic agents through the venous wall was evaluated by fluorescence microscopy. Damage to the adjacent femoral nerve was quantitatively evaluated by counting the numbers of axons in cross-sections. All the sclerotic agents caused vascular wall injuries and leakage into the surrounding tissues. The number of axons in the femoral nerve was significantly reduced following administration of absolute ethanol or 5% ethanolamine oleate, compared with normal saline. The results of this study suggest that sclerotic agents commonly leak out the vascular lumen, and some agents can cause adjacent nerve injury. It is important to be aware of this type of complication of sclerotherapy for venous malformations when selecting appropriate therapeutic interventions.


Scandinavian Journal of Plastic and Reconstructive Surgery and Hand Surgery | 2005

Simultaneous reconstruction of breast and well-projected nipple after expansion of mammary skin

Kotaro Yoshimura; Shinichi Wakita; Katsujiro Sato; Nobuyuki Kaji; Emiko Aiba; Daisuke Matsumoto; Hisayo Yamaoka; Takashi Nagase

The problem of postoperative reduction of projecting reconstructed nipples remains to be resolved. To this end we did a clinical study of reconstructing the nipple at the same time as the breast. A tissue-expander was placed under the skin of the breast at the first operation, and then the breast and nipple were reconstructed at the second. A nipple was reconstructed using a dermal-fat flap harvested from the myocutaneous flaps used for reconstruction of the breast. A small hole was made in the corresponding site of the skin of the breast, and the reconstructed nipple was projected through the hole. This method was used in 8 cases. This method is useful in reconstructing a breast without a pad of skin and a projected nipple simultaneously. Its disadvantages are the relatively weak blood supply of the flaps, and difficulty in calculating the position of the nipple. The procedure may be beneficial for selected cases.


Plastic and Reconstructive Surgery | 2017

A Temporoparietal Fascia Pocket Method in Elevation of Reconstructed Auricle for Microtia.

Takashi Kurabayashi; Hirotaka Asato; Yasutoshi Suzuki; Nobuyuki Kaji; Yoko Mitoma

Background: In two-stage procedures for reconstruction of microtia, an axial flap of temporoparietal fascia is widely used to cover the costal cartilage blocks placed behind the framework. Although a temporoparietal fascia flap is undoubtedly reliable, use of the flap is associated with some morbidity and comes at the expense of the option for salvage surgery. Methods: The authors devised a simplified procedure for covering the cartilage blocks by creating a pocket in the postauricular temporoparietal fascia. In this procedure, the constructed auricle is elevated from the head superficially to the temporoparietal fascia, and a pocket is created under the temporoparietal fascia and the capsule of the auricle framework. Then, cartilage blocks are inserted into the pocket and fixed. A total of 38 reconstructed ears in 38 patients with microtia ranging in age from 9 to 19 years were elevated using the authors’ method from 2002 to 2014 and followed for at least 5 months. To evaluate the long-term stability of the method, two-way analysis of variance (p < 0.05) was carried out to analyze the effect on the projection angles of the method (an axial temporoparietal fascia flap method versus a temporoparietal fascia pocket method) over long-term follow-up. Results: Good projection of the auricles and creation of well-defined temporoauricular sulci were achieved. Furthermore, the sulci had a tendency to hold their steep profile over a long period. Conclusions: The temporoparietal fascia pocket method is simple but produces superior results. Moreover, pocket creation is less invasive and has the benefit of sparing temporoparietal fascia flap elevation. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.


European Journal of Vascular and Endovascular Surgery | 2012

Extravascular Injection of Sclerotic Agents does not Affect Vessels in the Rat: Experimental Implications for Percutaneous Sclerotherapy of Arteriovenous Malformations

D. Sato; Masakazu Kurita; Mine Ozaki; Nobuyuki Kaji; A. Takushima; Kiyonori Harii

OBJECTIVES Sclerotherapy is useful for the treatment of arteriovenous vascular malformations. However, intravascular administration of sclerotic agents into small arteriovenous niduses is often difficult. Extravascular administration of sclerotic agents causes reduction of vascular flow on Doppler echo during clinical sclerotherapy. Therefore, we aimed to investigate whether the extravascular injection of sclerotic agents affects tiny vessels. DESIGN Animal study. MATERIALS The effect of extravascular injection of sclerotic agents on vessels was investigated using rat femoral and superficial inferior epigastric vessels. METHODS After surgical exposure of vessels, absolute ethanol, 5% ethanolamine oleate and 3% polidocanol were injected into perivascular surrounding tissues, and their effect on vessels was evaluated after 14 days using histology and coloured silicone rubber injection. RESULTS The integrity of the vascular lumen, endothelial cells and vascular patency were not affected by injection of sclerotic agents. CONCLUSIONS Attenuation of vascular flow of an arteriovenous shunt after extravascular injection of sclerotic agents is transient and/or trivial and does not cause disruption of vessels. Therefore, sclerotic agents should be delivered to obtain sufficient destruction of arteriovenous malformation lesions and blood flow.


Annals of Plastic Surgery | 2005

Changes in angiogenic gene expression in a case of expanded capillary malformation: does an expanded capillary malformation grow?

Nobuyuki Kaji; Takashi Nagase; Miki Nagase; Isao Koshima

We examined a 59-year-old woman with a capillary malformation (CM) in her thigh, which was serially excised. Interestingly, the remnant CM after the first excision was enlarged at the time of the second excision. To investigate whether this phenomenon was caused by mere passive expansion or regrowth, the CM specimens of the first operation (nonexpanded) and the second operation (expanded) were examined. Expressions of angiogenic genes Tie2 and Angiopoietin-1 were up-regulated within the expanded CM compared with the nonexpanded lesion, suggesting angiogenesis in the expanded CM. Expression pattern of the endothelial marker von Willebrand factor and the capillary densities were unchanged after the excision, suggesting that angiogenesis seen in the expanded CM resulted in reorganization of vascular networks. We consider that our data support a hypothesis that the expanded lesion in this case was caused by regrowth, not a passive expansion, of the CM.

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