Yuichiro Yabuki
Yokohama City University
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Publication
Featured researches published by Yuichiro Yabuki.
Journal of Vascular Surgery | 2012
Jiro Maegawa; Yuichiro Yabuki; Hiroto Tomoeda; Misato Hosono; Kazunori Yasumura
OBJECTIVE Lymphaticovenous anastomosis has been used for patients with peripheral lymphedema. However, the efficacy of this procedure is controversial due to a lack of evidence regarding postoperative patency. We sought to determine midterm postoperative patency of lymphaticovenous side-to-end anastomoses (LVSEAs) using indocyanine green fluorescence lymphography. METHODS This was a retrospective observational study set in a teaching hospital. Of 107 patients with chronic lymphedema who underwent 472 LVSEAs, 57 (223 anastomoses) consented to fluorescence lymphography and comprised the study cohort. The intervention consisted of a microsurgical LVSEA performed with a suture-stent method. Patients also had preoperative and postoperative complex decongestive physiotherapy. Anastomosis patency was assessed using indocyanine green fluorescence lymphography ≥6 months after surgery. Patency rates were calculated using Kaplan-Meier analysis. We assessed volume reduction on the operated-on limb and compared this between patients in whom anastomoses were patent and those in whom anastomoses were not obviously patent. RESULTS Patency could be evaluated only at the dorsum of the foot, ankle, and lower leg because the near-infrared rays emitted by the special camera used could not penetrate the deep subcutaneous layer containing collective lymphatics in areas such as the thigh. Several patterns were observed on fluorescence lymphography: straight, radial, and L-shaped. Cumulative patency rates of LVSEAs were 75% at 12 months and 36% at 24 months after surgery. No significant difference in volume change of the affected limb was seen between the 34 patients with patent anastomosis (600 ± 969 mL) and the 24 patients without obvious evidence of patency (420 ± 874 mL). CONCLUSIONS Although further study is required to determine factors leading to anastomotic obstruction and to optimize the results of microlymphatic surgery, the present LVSEA technique appears promising.
PLOS ONE | 2011
Shinji Kobayashi; Takanori Takebe; Yun-Wen Zheng; M. Mizuno; Yuichiro Yabuki; Jiro Maegawa; Hideki Taniguchi
Background Based on evidence from several other tissues, cartilage stem/progenitor cells in the auricular cartilage presumably contribute to tissue development or homeostasis of the auricle. However, no definitive studies have identified or characterized a stem/progenitor population in mice auricle. Methodology/Principal Findings The 5-bromo-2′-deoxyuridine (BrdU) label-retaining technique was used to label dividing cells in fetal mice. Observations one year following the labeling revealed that label-retaining cells (LRCs) were present specifically in auricular perichondrium at a rate of 0.08±0.06%, but LRCs were not present in chondrium. Furthermore, LRCs were successfully isolated and cultivated from auricular cartilage. Immunocytochemical analyses showed that LRCs express CD44 and integrin-α5. These LRCs, putative stem/progenitor cells, possess clonogenicity and chondrogenic capability in vitro. Conclusions/Significance We have identified a population of putative cartilage stem/progenitor cells in the auricular perichondrium of mice. Further characterization and utilization of the cell population should improve our understanding of basic cartilage biology and lead to advances in cartilage tissue engineering and novel therapeutic strategies for patients with craniofacial defects, including long-term tissue restoration.
Stem Cells | 2014
Mitsuru Mizuno; Shinji Kobayashi; Takanori Takebe; Hiroomi Kan; Yuichiro Yabuki; Takahisa Matsuzaki; Hiroshi Yoshikawa; Seiichiro Nakabayashi; Lee Jeong Ik; Jiro Maegawa; Hideki Taniguchi
In healthy joints, hyaline cartilage covering the joint surfaces of bones provides cushioning due to its unique mechanical properties. However, because of its limited regenerative capacity, age‐ and sports‐related injuries to this tissue may lead to degenerative arthropathies, prompting researchers to investigate a variety of cell sources. We recently succeeded in isolating human cartilage progenitor cells from ear elastic cartilage. Human cartilage progenitor cells have high chondrogenic and proliferative potential to form elastic cartilage with long‐term tissue maintenance. However, it is unknown whether ear‐derived cartilage progenitor cells can be used to reconstruct hyaline cartilage, which has different mechanical and histological properties from elastic cartilage. In our efforts to develop foundational technologies for joint hyaline cartilage repair and reconstruction, we conducted this study to obtain an answer to this question. We created an experimental canine model of knee joint cartilage damage, transplanted ear‐derived autologous cartilage progenitor cells. The reconstructed cartilage was rich in proteoglycans and showed unique histological characteristics similar to joint hyaline cartilage. In addition, mechanical properties of the reconstructed tissues were higher than those of ear cartilage and equal to those of joint hyaline cartilage. This study suggested that joint hyaline cartilage was reconstructed from ear‐derived cartilage progenitor cells. It also demonstrated that ear‐derived cartilage progenitor cells, which can be harvested by a minimally invasive method, would be useful for reconstructing joint hyaline cartilage in patients with degenerative arthropathies. Stem Cells 2014;32:816–821
Transplantation Proceedings | 2012
Takanori Takebe; Shinji Kobayashi; Hiroomi Kan; H. Suzuki; Yuichiro Yabuki; M. Mizuno; T. Adegawa; T. Yoshioka; Junzo Tanaka; Jiro Maegawa; Hideki Taniguchi
Transplantation of bioengineered elastic cartilage is considered to be a promising approach for patients with craniofacial defects. We have previously shown that human ear perichondrium harbors a population of cartilage progenitor cells (CPCs). The aim of this study was to examine the use of a rotating wall vessel (RWV) bioreactor for CPCs to engineer 3-D elastic cartilage in vitro. Human CPCs isolated from ear perichondrium were expanded and differentiated into chondrocytes under 2-D culture conditions. Fully differentiated CPCs were seeded into recently developed pC-HAp/ChS (porous material consisted of collagen, hydroxyapatite, and chondroitinsulfate) scaffolds and 3-D cultivated utilizing a RWV bioreactor. 3-D engineered constructs appeared shiny with a yellowish, cartilage-like morphology. The shape of the molded scaffold was maintained after RWV cultivation. Hematoxylin and eosin staining showed engraftment of CPCs inside pC-HAp/ChS. Alcian blue and Elastica Van Gieson staining showed of proteoglycan and elastic fibers, which are unique extracellular matrices of elastic cartilage. Thus, human CPCs formed elastic cartilage-like tissue after 3-D cultivation in a RWV bioreactor. These techniques may assist future efforts to reconstruct complicate structures composed of elastic cartilage in vitro.
Aesthetic Surgery Journal | 2012
Jiro Maegawa; Shinji Kobayashi; Yuichiro Yabuki; Kouichi Hirotomi; Kazunori Yasumura; Toshinori Iwai
BACKGROUND For patients with senile ptosis, aesthetic blepharoplasty can be combined with ptosis surgery. However, the amount of skin excision necessary in blepharoplasty is not clearly defined by measurements of the upper eyelids. OBJECTIVES The authors preoperatively evaluate the amount of skin to be excised in blepharoplasty. METHODS Fifty patients with bilateral senile ptosis were included in this study. The amount of skin to be excised from the upper eyelids was selected based on preoperative measurements of redundant skin, equivalent to the maximum lid height (MLH) while manually stretching the eyelid upwards minus resting lid height (RLH) with the eyes closed passively. Ptosis surgery (such as plication of the aponeurosis) followed blepharoplasty. RESULTS Preoperatively, mean MLH was 35 mm on the right and 36 mm on the left. Mean RLH was 25 mm bilaterally. The mean amount (height) of excised skin was 10 mm on the right and 11 mm on the left. At six months postoperatively, mean MLH and RLH were 29 and 23 mm on both sides, respectively. Significant differences between pre- and postoperative MLH and RDH were seen on both sides (P<.001). No complications due to overexcision were observed, but revision was performed for two patients with asymmetry of the lid folds and five patients with recurrence of drooping. CONCLUSIONS Preoperative measurements of upper eyelid heights (stretched and at rest) appear useful in determining the amount of skin excision required in blepharoplasty for senile ptosis. LEVEL OF EVIDENCE 4.
British Journal of Oral & Maxillofacial Surgery | 2013
Toshinori Iwai; Kazunori Yasumura; Yuichiro Yabuki; Susumu Omura; Yoshiro Matsui; Shinji Kobayashi; Ryo Fujimaki; Makiko Okubo; Iwai Tohnai; Jiro Maegawa
Treatment of fracture of the naso-orbitoethmoid (NOE) complex is difficult. There are not only aesthetic issues but also functional consequences related to the lacrimal system. Because prophylactic lacrimal intubation for such fractures remains controversial, we have assessed the effectiveness of intraoperative lacrimal intubation to prevent epiphora as a result of such injuries. Thirteen patients diagnosed with craniomaxillofacial fractures including fractures of the NOE complex were included in the study; 10 had unilateral fractures and 3 bilateral. Computed tomography (CT) showed all patients had displaced fragments that had the potential to damage the lacrimal duct. In 7 patients the fractures included the canthal region and in 6 they did not. All patients were treated by open reduction and internal fixation under general anaesthesia, followed by intraoperative lacrimal intubation unilaterally or bilaterally as required. Lacrimal intubation with a silicone tube was successful in all 13 patients (16 sides). The tube was removed 2-9 months (mean 3.8) postoperatively and no subsequent epiphora were seen during follow-up (mean (3-29 months) 11.3 months). Lacrimal intubation for at least 2 months may prevent epiphora caused by injury to the nasolacrimal system after fractures of the NOE complex.
Cell Transplantation | 2016
Shintaro Kagimoto; Takanori Takebe; Shinji Kobayashi; Yuichiro Yabuki; Ayaka Hori; Koichi Hirotomi; Taro Mikami; Toshimasa Uemura; Jiro Maegawa; Hideki Taniguchi
We recently developed a promising regenerative method based on the xenotransplantation of human cartilage progenitor cells, demonstrating self-renewing elastic cartilage reconstruction with expected long-term tissue restoration. However, it remains unclear whether autotransplantation of cartilage progenitors may work by a similar principle in immunocompetent individuals. We used a nonhuman primate (monkey) model to assess the safety and efficacy of our regenerative approach because the model shares characteristics with humans in terms of biological functions, including anatomical features. First, we identified the expandable and multipotent progenitor population from monkey ear perichondrium and succeeded in inducing chondrocyte differentiation in vitro. Second, in vivo transplanted progenitor cells were capable of reconstructing elastic cartilage by xenotransplantation into an immunodeficient mouse. Finally, the autologous monkey progenitor cells were transplanted into the subcutaneous region of a craniofacial section and developed mature elastic cartilage of their own 3 months after transplantation. Furthermore, we attempted to develop a clinically relevant, noninvasive monitoring method using magnetic resonance imaging (MRI). Collectively, this report shows that the autologous transplantation of cartilage progenitors is potentially effective for reconstructing elastic cartilage. This principle will be invaluable for repairing craniofacial injuries and abnormalities in the context of plastic and reconstructive surgery.
Journal of Foot & Ankle Surgery | 2018
Taro Mikami; Eriko Kaida; Yuichiro Yabuki; Sho Kitamura; Kenichi Kokubo; Jiro Maegawa
The distally based sural flap is regarded as the first choice for reconstruction in the distal part of the lower leg because the flap is easy to raise, reliable in its blood supply, and prone to only a few complications. Limited data have investigated the details of treatment in cases of failure of distally based sural flaps. We report a case of calcaneal osteomyelitis in which a successful outcome was finally obtained with a partially necrosed, distally based sural flap using negative pressure wound therapy with basic fibroblast growth factor spray. The 2-year follow-up examination was uneventful. Moreover, the patient was able to walk freely with an ankle-foot orthosis in her house. This technique can be considered as a useful and effective option to recover unfavorable results of distally based sural flaps.
BMC Surgery | 2017
Taro Mikami; Shintaro Kagimoto; Yuichiro Yabuki; Kazunori Yasumura; Toshinori Iwai; Jiro Maegawa; Nobuyasu Suganuma; Shohei Hirakawa; Katsuhiko Masudo
BackgroundWe present the cases of 2 patients with invasive thyroid cancer, who underwent reconstructive surgery using a deltopectoral flap. Although the overall rate of extrathyroidal extension in patients with thyroid cancer is quite low, skin invasion is the most common pattern observed. Reconstructive surgery, involving local skin flaps, is required in these patients. The deltopectoral flap relies on the blood supply from intercostal perforators of the internal thoracic artery and usually requires skin grafting to the donor site. The internal thoracic artery is rarely sacrificed in these cases, even in an advanced surgery such as in patients with invasive thyroid cancer.Case presentationA 55-year-old man with a distended thyroid gland presented to our hospital. He underwent advanced surgery, including skin excision, because we suspected that his tumor was thyroid cancer. The defect was covered with an ipsilateral deltopectoral flap via transposition of the flap, without skin grafting. In the second case, a 67-year-old woman with thyroid cancer that metastasized to her neck lymph nodes presented to our institution. Although the ipsilateral internal thoracic artery was sacrificed near its origin during tumor resection, the deltopectoral flap was raised in the usual manner without any complications. The skin defect caused by the tumor resection was covered with the flap. The patient had an uneventful clinical course for more than 2 years of follow-up.These 2 cases show the effectiveness of using the deltopectoral flap as a reconstructive option for patients with thyroid cancer who underwent radical surgery, resulting in a skin defect. The first case shows that this flap does not always require skin grafting to the donor site. To our knowledge, the second case may be the first report of a deltopectoral flap that was safely raised and applied with resection of the bifurcation of the ipsilateral internal thoracic artery.ConclusionsAlthough thyroid cancer surgery with surrounding skin excision is a rare procedure, we found that the deltopectoral flap was useful and should be the first choice for patients undergoing reconstructive surgery, whether the bifurcation of the ipsilateral internal thoracic artery is sacrificed.
Journal of vascular surgery. Venous and lymphatic disorders | 2015
S. Matsubara; Jiro Maegawa; S. Kitayama; T. Mikami; K. Hirotomi; E. Adachi; S. Kagimoto; Y. Sasaki; Y. Maruyama; Yuichiro Yabuki
Objectives: Lymphoscintigraphy is standard diagnostic imaging for the limbs of patients with lymphedema and also a good modality for functional assessment of lymph flow. However, this modality cannot reveal individual lymphatic vessels that are candidates for lymphaticovenous anastomosis. We report a preliminary study to detect the lymphatic vessel and to observe its flow in real time in the lower extremities of healthy volunteers with contrast-enhanced ultrasonography (ce-USG). Methods: The lymphatic vessels of the lower extremities (10 limbs) of 10 healthy volunteers were examined. They were all female, and the mean age was 42.5 years. First, indocyanine green fluorescence lymphography was performed to mark the superficial lymphatic vessels. Next, the contrast agent perflubutane (Sonazoid) was injected into the dorsum, and lymphatic vessels were detected by ce-USG. To check the optimal condition of injection, the point of it changed 1, 2, and 4 points, and the volume in total changed 0.1, 0.2, and 0.8 mL. The lymphatic flow under manual lymph drainage was investigated. Results: There is no remarkable side effect in this study. The lymphatic vessels were visible in all cases when the contrast agent injected was 0.8 mL and according to the line marked by indocyanine green fluorescence lymphography. They run superficial in the subcutaneous area from dorsum to groin continuously. Most of them were around the great saphenous vein (Fig). No perforated lymphatic vessel through the fascia was observed. In the inguinal region, some lymphatic vessels come into the lymphatic node, and the internal side of the lymphatic node was enhanced clearly. We could detect more lymphatic vessels depending on the injected points. During manual lymph drainage, they were enhanced clearly according to the rhythm of drainage. Conclusions: The study shows that ce-USG could be a useful diagnostic modality to clearly detect normal lymphatic vessels and to evaluate functional flow in real-time fashion in the normal limbs. In lymphaticovenous anastomosis treatment for lymphedema in selected patients, it is important to detect functional lymph vessels for the long-term patency and decreasing volume of diseased limb. The lymphatic flow in lymphedema patients was sometimes changed from superficial dominant to deep dominant. Further study to investigate the relation between superficial lymphatic flow and deep lymphatic flow is necessary in patients with lymphedema.