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Dive into the research topics where Ataru Sunaga is active.

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Featured researches published by Ataru Sunaga.


Plastic and Reconstructive Surgery | 2014

Brava and autologous fat grafting for breast reconstruction after cancer surgery.

Hirokazu Uda; Yasushi Sugawara; Syunji Sarukawa; Ataru Sunaga

Background: Although autologous fat grafting is widely accepted for breast reconstruction, its indications remain limited to minor contour deformities after reconstruction and small deformities after breast-conserving surgery. The authors describe a case series of total or nearly total breast reconstructions treated with the perioperative use of a vacuum-based external tissue expander (i.e., the Brava device) followed by autologous fat grafting. Methods: The authors assessed the clinical outcomes and aesthetic results in six nonirradiated total mastectomy cases and eight severely deformed irradiated breast-conserving surgery cases. Total Brava wearing time and skin complications were also investigated. Results: The number of fat grafting procedures required ranged from one to four, and the mean amount of fat grafted during each procedure was 256 cc (range, 150 to 400 cc). Postoperative fat lysis and cellulitis occurred in two cases (14.3 percent). Brava worked effectively for total mastectomy cases, and improvement in the total aesthetic score was significantly higher than that in the breast-conserving surgery cases. All patients wore the device for more than 8 hours/day. The most frequent skin complication was dermatitis [n = 11 (79 percent)], which occurred in all breast-conserving surgery cases. Conclusions: Brava was well tolerated by patients. Fat grafting with perioperative use of Brava is an alternative to total breast reconstruction in total mastectomy cases. However, for severely deformed breast-conserving surgery breasts treated with radiation therapy, the contracted skin was difficult to extend despite Brava use, and the results were less satisfactory. These cases also experienced a higher incidence of skin complications compared with the total mastectomy cases. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.


Plastic and Reconstructive Surgery | 2010

Multidirectional Cranial Distraction Osteogenesis for the Treatment of Craniosynostosis

Yasushi Sugawara; Hirokazu Uda; Shunji Sarukawa; Ataru Sunaga

Background: Although many operative methods for the treatment of craniosynostosis exist, whether any difference in outcome could be associated with either the childs age at surgery or the extent of the operation remains to be elucidated. The authors have developed a method of distraction osteogenesis for craniosynostosis that uses a new multidirectional cranial distraction osteogenesis system. Methods: From 2003 to 2008, 26 selected patients with syndromic and nonsyndromic craniosynostosis were treated with this method. The ages of the patients ranged from 9 to 139 months (median, 27 months). The follow-up period ranged from 13 to 81 months (median, 49 months). Results: The postoperative course was uneventful in all cases. The mean blood transfusion was 20.9 ml/kg. The mean postoperative hospital stay was 12 days. Sixteen of 49 (32.7 percent) anchor pins used in the first eight patients loosened because of bone absorption during the consolidation period. After the authors altered the screw shape, loosening occurred in seven of 81 pins (8.6 percent) in the last 18 patients. Loosening occurred in 28 of 204 traction pins (13.7 percent) among all patients. The phase of activation ranged from 8 to 14 days (mean, 10.5 days) and the consolidation period ranged from 21 to 42 days (mean, 29 days). Conclusions: Overall, distraction osteogenesis with the multidirectional cranial distraction osteogenesis method is safe and effective. The authors conclude that the multidirectional cranial distraction osteogenesis method constitutes an excellent alternative for all phenotypes of syndromic or nonsyndromic craniosynostosis.


Plastic and Reconstructive Surgery | 2017

Mechanical Micronization of Lipoaspirates: Squeeze and Emulsification Techniques.

Takanobu Mashiko; Szu-Hsien Wu; Jingwei Feng; Koji Kanayama; Kaori Kinoshita; Ataru Sunaga; Mitsunaga Narushima; Kotaro Yoshimura

Background: Condensation of grafted fat has been considered a key for achieving better outcomes after fat grafting. The authors investigated the therapeutic potential of two mechanical tissue micronizing procedures: squeeze and emulsification. Methods: Human aspirated fat was centrifuged (centrifuged fat) and fragmented with an automated slicer (squeezed fat). Alternatively, centrifuged fat was emulsified by repeated transfer between two syringes through a small-hole connecter and then separated by mesh filtration into two portions: residual tissue of emulsified fat and filtrated fluid of emulsified fat. The four products were examined for cellular components. Results: Histologic and electron microscopic analyses revealed that squeezed fat and residual tissue of emulsified fat contained broken adipocytes and fragmented capillaries. Compared with centrifuged fat, the squeezed fat and residual fat products exhibited increased specific gravity and increased numbers of adipose-derived stem/stromal cells and endothelial cells per volume, suggesting successful cell/tissue condensation in both squeezed fat and residual tissue of emulsified fat. Although cell number and viability in the stromal vascular fraction were well maintained in both squeezed fat and residual fat, stromal vascular fraction culture assay showed that adipose-derived stromal cells were relatively damaged in residual tissue of emulsified fat but not in squeezed fat. By contrast, no adipose-derived stromal cells were cultured from filtrated fluid of emulsified fat. Conclusions: The authors’ results demonstrated that mechanical micronization is easily conducted as a minimal manipulation procedure, which can condense the tissue by selectively removing adipocytes without damaging key components, such as adipose-derived stromal cells and endothelial cells. Depending on the extent of adipocyte removal, the product may be a useful therapeutic tool for efficient tissue volumization or therapeutic revitalization/fertilization. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, V.


Scientific Reports | 2017

An injectable non-cross-linked hyaluronic-acid gel containing therapeutic spheroids of human adipose-derived stem cells

Jingwei Feng; Kazuhide Mineda; Szu-Hsien Wu; Takanobu Mashiko; Kentaro Doi; Shinichiro Kuno; Kahori Kinoshita; Koji Kanayama; Rintaro Asahi; Ataru Sunaga; Kotaro Yoshimura

For chronic wounds, the delivery of stem cells in spheroidal structures can enhance graft survival and stem cell potency. We describe an easy method for the 3D culture of adipose-derived stem/stromal cells (ASCs) to prepare a ready-to-use injectable. We transferred suspensions of monolayer-cultured ASCs to a syringe containing hyaluronic acid (HA) gel, and then incubated the syringe as a 3D culture vessel. Spheroids of cells formed after 12 h. We found that 6 × 106 ASCs/ml in 3% HA gel achieved the highest spheroid density with appropriate spheroid sizes (20–100 µm). Immunocytology revealed that the stem cell markers, NANOG, OCT3/4, SOX-2, and SSEA-3 were up-regulated in the ASC spheroids compared with those in nonadherent-dish spheroids or in monolayer cultured ASCs. In delayed wound healing mice models, diabetic ulcers treated with ASC spheroids demonstrated faster wound epithelialization with thicker dermis than those treated with vehicle alone or monolayer cultured ASCs. In irradiated skin ulcers in immunodeficient mice, ASC spheroids exhibited faster healing and outstanding angiogenic potential partly by direct differentiation into α-SMA+ pericytes. Our method of 3D in-syringe HA gel culture produced clinically relevant amounts of ready-to-inject human ASC microspheroids that exhibited superior stemness in vitro and therapeutic efficacy in pathological wound repair in vivo.


Plastic and reconstructive surgery. Global open | 2013

The Fate of Nonvascularized Fat Grafts: Histological and Bioluminescent Study

Ataru Sunaga; Yasushi Sugawara; Yoko Katsuragi-Tomioka; Eiji Kobayashi

Background: Nonvascularized fat grafting has become one of the most popular options for breast contouring. However, the survival process of the grafts remains to be elucidated. In this study, we tracked the fate of nonvascularized fat grafts with in vivo bioluminescence and immunohistochemistry. Methods: Nonvascularized fat grafts or vascularized adiposal flaps from luciferase transgenic rats were transplanted to Lewis rats. The bioluminescent signals from the grafts were monitored longitudinally. In addition, nonvascularized fat grafts from Lewis rats were engrafted to Lewis rats and the viability of the adipocytes in the grafts was evaluated with immunohistochemical staining for perilipin at postoperative week 1, 2, 3, 4, and 6. Results: The bioluminescent signals from the nonvascularized fat grafts increased drastically from postoperative day 3 to 7, stayed flat from day 7 to 12, and declined from day 12 to 17, whereas those from the vascularized fat flaps remained throughout the entire postoperative period. Immunohistochemistry revealed that the survival zones with large adipocytes were decreased within 2 weeks and the regenerating zones with small adipocytes appeared after 3 weeks. Conclusions: Our study showed the process of survival and regeneration of nonvascularized fat grafts and suggested that graft-derived stromal cells proliferated within 7 days after transplantation and differentiated into adipocytes after postoperative week 3.


Journal of Plastic Reconstructive and Aesthetic Surgery | 2015

Comparison of abdominal wall morbidity between medial and lateral row-based deep inferior epigastric perforator flap

Hirokazu Uda; Yoko Katsuragi Tomioka; Syunji Sarukawa; Ataru Sunaga; Yasusih Sugawara

INTRODUCTION Although deep inferior epigastric perforator (DIEP) flap is associated with decreased abdominal morbidity, motor nerve damage during flap elevation cannot be ignored. We compared abdominal morbidity after elevation of DIEP flap with lateral row perforators (L-DIEP) and medial row perforators (M-DIEP) to determine the perforators associated with less abdominal morbidity. METHODS Women who underwent breast reconstruction with DIEP flaps (n = 49) were included in this study. Among them, M-DIEP and L-DIEP were harvested in 27 and 22 patients, respectively. Pre- and postoperative trunk flexor muscle ability (at 3 and 6 months after surgery) was measured prospectively in all patients using an isokinetic dynamometer. The patients were also investigated for postoperative pain, stiffness, activity, bulging, and lumbago. RESULTS At 3 months after surgery, a significant decrease in trunk flexor muscle ability was observed in the patients of the L-DIEP group, but they recovered well after further 3 months. However, the recovery tended to be weak. Similar results were obtained with respect to pain, stiffness, activity, bulging, and lumbago between the two groups at 6 months after surgery. CONCLUSIONS Dominant perforators for DIEP flap elevation should be chosen by considering flap viability. However, surgeons should be aware that elevation with L-DIEP is associated with a high risk of nerve injury, and may in turn result in short-term decreases in trunk flexor muscle ability. Therefore, precautionary methods should be taken by the surgeons to preserve the motor nerve with atraumatic dissection, especially during elevation with L-DIEP.


Aesthetic Surgery Journal | 2015

Shaping of the Unaffected Breast with Brava-Assisted Autologous Fat Grafting to Obtain Symmetry after Breast Reconstruction

Hirokazu Uda; Yoko Katsuragi Tomioka; Yasusih Sugawara; Syunji Sarukawa; Ataru Sunaga

BACKGROUND In breast reconstruction, symmetry is a vital issue. However, when the original breast is unusually shaped or the patient desires augmentation at the time of reconstruction, obtaining symmetrical breasts becomes difficult. OBJECTIVES The authors performed shaping of unaffected breasts by Brava-assisted autologous fat grafting to enhance breast symmetry, and evaluated the clinical results to validate this new approach. METHODS Brava-assisted autologous fat grafting was performed to the unaffected breasts of 12 patients who had undergone unilateral breast reconstruction. The procedure was used for augmentation in six patients and to correct ptosis, volume, and tuberous breast deformity in three, two, and one patient, respectively. Clinical outcomes were assessed in all 12 patients. RESULTS All patients could complete fat grafting within two sessions (one session in nine patients and two sessions in three patients). The mean volume of grafted fat per session was 211 cc in all patients. The mean retention rate of grafted fat was 58.9% in the 10 patients for whom the retention rate could be calculated using preoperative and postoperative magnetic resonance imaging (MRI). Postoperative MRI revealed small benign foci in two patients (16.7%), which were not palpable and did not become a clinical problem. A postoperative mammography revealed a small agglutinate calcification in one patient, which was determined to be benign through biopsy. CONCLUSIONS Shaping the unaffected breast by autologous fat grafting combined with Brava is predictable, effective, and feasible as an aesthetic adjunct to unilateral breast reconstruction to achieve breast symmetry. LEVEL OF EVIDENCE 4 Therapeutic.


Plastic and Reconstructive Surgery | 2013

The concept and method of closed reduction and internal fixation: a new approach for the treatment of simple zygoma fractures.

Hirokazu Uda; Hideaki Kamochi; Yasushi Sugawara; Syunji Sarukawa; Ataru Sunaga

Background: The authors have developed a new minimally invasive surgical procedure for simple zygoma fractures, a closed reduction and internal fixation method, that uses a cannulated cortical screw system. Methods: From 2007 to 2012, 42 selected patients with simple zygoma fractures without ocular problems or shear at the zygomatic frontal portion were treated with this method. The mean age of the patients was 33 years (range, 13 to 77 years). Results: The authors achieved good repositioning, equivalent to results achieved with conventional procedures in all cases. No notable complication occurred except for minor infection in two cases. Mean operative time was 32 minutes (range, 19 to 58 minutes). Postoperative relapse was found only in the posterior direction (p < 0.001), but the distance of that was so small (mean, 0.47 mm) that it did not cause any problem clinically. Conclusions: Although further improvement might be needed, such as screw specification, the closed reduction and internal fixation method has many advantages: short operative time, less effect on soft tissue, maintenance of bone healing potential, and decreased postoperative pain and swelling. The authors concluded that this method has the potential to become a future surgical procedure for simple zygoma fractures. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.


Plastic and Reconstructive Surgery | 2017

Blood Congestion Can Be Rescued by Hemodilution in a Random-Pattern Skin Flap

Koji Kanayama; Kazuhide Mineda; Takanobu Mashiko; Szu-Hsien Wu; Jingwei Feng; Kahori Kinoshita; Ataru Sunaga; Kotaro Yoshimura

Background: There is no standard method to ensure survival of random-pattern skin flaps. The authors developed a rat anemia model to observe survival of random-pattern skin flaps after blood transfusion and hemodilution. Methods: Anemia was induced by withdrawal of 35 percent blood volume followed by compensation with the same amount of blood (blood transfusion model) or plasma equivalent (normovolemic hemodilution). Control rats were subjected to a sham procedure. Subsequently, a random-pattern skin flap (1.5 × 6 cm) was elevated on the back of each rat. Physiologic assessments of flap vascularity/viability were performed using laser Doppler spectrophotometry before and after flap elevation. Results: The normovolemic hemodilution group showed anemia (hemoglobin, 9.5 ± 0.8 g/dl) but less flow occlusion and greater flap survival (72.8 ± 8.6 percent) compared with control (57.4 ± 9.6 percent; p < 0.01) and blood transfusion (62.1 ± 6.5 percent; p < 0.089) groups. In control and blood transfusion groups but not the normovolemic hemodilution group, blood flow was decreased and relative quantity of hemoglobin was increased toward the flap tip, indicating congestion. In control and blood transfusion groups, blood flow and tissue oxygen saturation dropped after flap elevation, but recovered by day 7; congestion gradually improved by day 7. Conclusions: The authors determined that congestion promoted necrosis and hemodilution reduced microcirculatory occlusion and increased blood flow and oxygenation in skin flaps. It was suggested that perioperative hemodilution is superior to blood transfusion in any flap operations unless there is a critical systemic need for blood transfusion.


Journal of Korean Neurosurgical Society | 2016

Distraction Osteogenesis Update: Introduction of Multidirectional Cranial Distraction Osteogenesis

Akira Gomi; Ataru Sunaga; Hideaki Kamochi; Hirofumi Oguma; Yasushi Sugawara

In this review, we discuss in detail our current procedure for treating craniosynostosis using multidirectional cranial distraction osteogenesis (MCDO). The MCDO method allows all phenotypes of skull deformity to be reshaped by distraction osteogenesis, except in patients who are 5 months of age or younger and patients with posterior cranial vault problems. We report the results of clinical data of 36 children with craniosynostosis who underwent MCDO between 2005 and 2014 in our institute. This method has the following benefits, such as a high flexibility of reshaping, shorter treatment period and less invasive secondary intervention. We also discuss the other distraction osteogenesis techniques that are used to treat craniosynostosis and compare them with MCDO. The preferred procedure for correction of craniosynostosis may depend on the patients age, the extent of deformity, and the extent of correction achievable by surgery. We can arrange the combinations of various methods according to the advantage and disadvantage of each technique.

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Hirokazu Uda

Jichi Medical University

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Rintaro Asahi

Jichi Medical University

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Daekwan Chi

Jichi Medical University

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