Keisuke Imai

Kagawa University, Takamatu, Kagawa, Japan

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Publications (17)29.41 Total impact

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    ABSTRACT: Blepharophimosis-ptosis-epicanthus inversus syndrome (BPES) is a rare, congenital, surgically challenging disease. We undertook an objective, functional, and cosmetic comparison between the modified Uchida procedure and the Mustarde procedure on Asian patients with BPES.
    Annals of plastic surgery. 08/2014;
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    ABSTRACT: The authors have developed a unique multilayered culture method that expands to large volumes elastic chondrocytes from a small piece of human auricular cartilage. In this study, the authors applied the two-stage transplantation method for cultured auricular chondrocytes to difficult cases of nasal/chin reconstruction where subcutaneous tissue is thin or scarred. Auricular chondrocytes were cultured and expanded to sufficiently large volumes, and then, in a two-stage transplantation process, injection-transplanted into a patient's lower abdomen, where they were regenerated into larger chondrofat composite tissue in 6 months and used as a material for nasal/chin reconstruction. The authors then performed histologic and electron microscopic analysis of serial cross-sections and magnetic resonance imaging analysis of the chondrofat composite tissue. The cultured auricular chondrocytes consistency regenerated intraabdominally to a larger, stable neocartilage, with adherent fat tissue within 6 months. Eighteen patients (nose, n = 14; chin, n = 4) underwent this procedure, and the chondrofat composite tissue was stable after 1 to 5 years' postoperative follow-up. The chondrofat composite tissue maintained good shape, with no major complications. Magnetic resonance imaging showed that the chondrofat composite tissue was regenerated and vascularized in the abdomen in all 18 cases (100 percent). Infection and total absorption were not seen. Only partial absorption was noted (5.6 percent). The chondrofat composite tissue was found to be a new innovative graft material in which neocartilage is regenerated to be continuous with fat tissue by means of the neoperichondrium. It has thereby become possible to perform the previously impossible simultaneous reconstruction of cartilage and fat tissue.
    Plastic and reconstructive surgery 12/2013; 132(6):1467-77. · 2.74 Impact Factor
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    ABSTRACT: Although cranial distraction osteogenesis (CDO) is beneficial, few studies have reported on detailed operative procedures and postoperative cranial growth. Herein, we demonstrated the objective effectiveness of CDO in younger infants. The study included infants who underwent primary cranial distraction for craniosynostosis. Infants who had hydrocephalus were excluded and those who underwent additional osteotomy surgeries were analysed before the subsequent procedures. The infants' computed tomography data were analysed using Mimics(®) software (Materialise, Leuven, Belgium) to calculate the cranial volumes and compare them with the Abbott curve for a normal population. We defined cranial growth gap as the difference between the subject data and normal infant data to demonstrate the perioperative effects on cranial growth. CDO was performed in 10 infants. The mean infant age at the time of surgery was 6.4 months (range, 24-61 months) and the mean duration of postoperative follow-up was 38.9 months (range, 24-61 months). Five infants with Crouzon syndrome and five with Apert's syndrome were included. All infants showed postoperative cranial growth, but cranial growth gap showed postoperative declines for a certain period, indicating cranial growth suppression immediately following expansion. At the last follow-up, all cases were within ±2 standard deviation (SD) compared with the normal population. We derived a formula to predict the CDO target volume using the declining cranial growth gap curve. CDO was applicable and suitable for younger infants requiring aggressive cranial expansion.
    Journal of Plastic Reconstructive & Aesthetic Surgery 09/2013; · 1.44 Impact Factor
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    ABSTRACT: Crouzon and Apert syndromes are frequently complicated by ocular abnormalities and patients with these syndromes often present with abnormal ocular morphology. The present study assesses orbital volume and ocular complications in patients associated with Crouzon and Apert syndromes.During an 8-year period starting in 2002, fronto-orbital advancement was used for cranial expansion on 23 cases of syndromic craniosynostosis. Of those, it was possible to evaluate 5 Crouzon and eight Apert syndrome cases. Orbital volume was measured using multislice CT scans. Both preoperative and postoperative orbital volumes were compared with normal orbital volume.Preoperative orbital volume was 5.8 to 10.0 cm (mean, 7.1 cm) in patients with Crouzon syndrome and 7.2 to 10.8 cm (mean, 9.1 cm) in patients with Apert syndrome. Postoperative intraorbital volume was 9.4 to 11.2 cm (mean, 10.4 cm) in patients with Crouzon syndrome and 11.6 to 13.2 cm (mean, 12.4 cm) in patients with Apert syndrome. The mean of orbital volume relative to the normal volume was 58% preoperatively and 74% postoperatively in patients with Crouzon syndrome and 69% (56-81%) preoperatively and 88% (81-95%) postoperatively in patients with Apert syndrome.In conclusion, orbital volume was smaller in the Crouzon syndrome group than in the Apert syndrome group, and symptoms, such as exophthalmos and exotropia, were noted in the Crouzon syndrome group. Orbit expansion did not fully restore normal orbital volume, but in most cases, it was useful for alleviation of preoperative symptoms (exophthalmos/eyeball prolapse, corneal erosion, conjunctivitis).
    The Journal of craniofacial surgery 01/2013; 24(1):191-4. · 0.81 Impact Factor
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    ABSTRACT: We have developed a unique method that allows us to culture large volumes of chondrocyte expansion from a small piece of human elastic cartilage. The characteristic features of our culturing method are that fibroblast growth factor-2 (FGF2), which promotes proliferation of elastic chondrocytes, is added to a culture medium, and that cell-engineering techniques are adopted in the multilayered culture system that we have developed.( 1-4 ) We have subsequently discovered that once multilayered chondrocytes are transplanted into a human body, differentiation induction that makes use of surrounding tissue occurs in situ, and a large cartilage block is obtained through cartinogenesis and matrix formation. We have named this method two-stage transplantation. We have clinically applied this transplantation method to the congenital ear defect, microtia, and reported successful ear reconstruction.( 4 ) In our present study, we demonstrated that when FGF2 was added to elastic chondrocytes, the cell count increased and the level of hyaluronic acid, which is a major extracellular matrix (ECM) component, increased. We also demonstrated that these biochemical changes are reflected in the morphology, with the elastic chondrocytes themselves producing a matrix and fibers in vitro to form a natural scaffold. We then demonstrated that inside the natural scaffold thus formed, the cells overlap, connect intercellularly to each other, and reconstruct a cartilage-like three-dimensional structure in vitro. We further demonstrated by immunohistochemical analysis and electron microscopic analysis that when the multilayered chondrocytes are subsequently transplanted into a living body (abdominal subcutaneous region) in the two-stage transplantation process, neocartilage and neoperichondrium of elastic cartilage origin are regenerated 6 months after transplantation. Further, evaluation by dynamic mechanical analysis showed the regenerated neocartilage to have the same viscoelasticity as normal auricular cartilage. Using our multilayered culture system supplemented with FGF2, elastic chondrocytes produce an ECM and also exhibit an intercellular network; therefore, they are able to maintain tissue integrity post-transplantation. These findings realized a clinical application for generative cartilage surgery.
    Tissue Engineering Part A 05/2012; 18(19-20):2020-9. · 4.64 Impact Factor
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    ABSTRACT: Patients with syndromic craniosynostosis have many problems involving the upper airway, laryngotracheal airway, and tracheobronchial tree. Evaluation of tracheobronchial disorders in syndromic craniosynostosis is very important for accurately diagnosing these problems. We have used three-dimensional computed tomography (CT) imaging of the tracheobronchial tree (three-dimensional tracheal CT imaging) since a multidetector CT was installed in our hospital in 2004. In this study, we assessed the configuration of the tracheobronchial system using three-dimensional tracheal CT imaging and bronchoscopy.During the period from 2004 to 2009, 48 patients with syndromic craniosynostosis underwent surgery at our hospital. Of those, 16 patients required tracheostomy. These syndromic craniosynostosis cases were examined with three-dimensional tracheal CT imaging and bronchoscopy. All CT scans were performed on a multidetector CT (120 kV, 22-120 mA, 0.5 s/slice, 1-mm slice; Aquilion; Toshiba Co, Tokyo, Japan) without respiratory suppression.All 16 study patients presented with severe stenosis of the upper airway on bronchoscopic examination. Seven were confirmed to have abnormalities by both bronchoscopy and three-dimensional tracheal CT imaging. Four were confirmed to have abnormalities on either bronchoscopy or three-dimensional tracheal CT imaging, whereas 5 patients were apparently free of abnormalities as determined by both modalities.In conclusion, it was possible to accurately assess the configuration of the tracheobronchial system using both three-dimensional tracheal CT imaging and bronchoscopy. Our results suggest these examinations to be very useful for assessing the optimal timing of decannulation and respiratory function prognosis.
    The Journal of craniofacial surgery 09/2011; 22(5):1579-83. · 0.81 Impact Factor
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    ABSTRACT: In 1997 the authors presented the case of a 3-year-old girl who underwent complete resection of a huge tumor via a new technique using a dismasking flap. Since that report, 14 patients have undergone surgery using this technique. There have been few reports on long-term follow-up after a craniofacial surgical approach and reconstruction of a huge tissue defect. The authors report details of this procedure based on these cases, including long-term follow-up in the original case. The dismasking flap is a cranioorbitofacial degloving method that uses a circumpalpebral approach with or without piriform margin incisions and presents a wide surgical field under direct vision. Fourteen patients have undergone surgery using the dismasking flap technique. These patients had multiple craniofacial bone fractures (3 cases) and malignant or premalignant craniofacial tumors (11 cases). Patients ranged in age from 3 to 62 years old. The longest follow-up period was 15 years. The results of these cases are reported regarding changes in the facial bones and soft tissues with growth, the various pathologies involved, and complications. Complications using this approach were lagophthalmos with ectropion of the lower eyelid, disturbance of the superior orbital nerve, disturbance of the inferior orbital nerve, maxillary hypoplasia, and blepharoptosis. In all affected patients these complications were almost always temporary. In 2 of the 14 cases, a repair operation for lagophthalmos was necessary, while others showed spontaneous improvement approximately 6 months to a year after the procedure. In the case with the longest follow-up duration, the patient's nose is asymmetrical, especially the alar portion, due to hypoplasia of the grafted bone and/or the fixation with titanium miniplates. This flap is very useful for en bloc resection of huge skull base tumors, multiple craniofacial bone fractures, and as a lateral approach to a deep portion of the middle cranial base. Careful attention is necessary, however, because one may encounter unexpected complications if one does not ensure adequate protection of the perioperative flap. Meticulous postoperative management is also essential.
    Journal of Neurosurgery Pediatrics 04/2011; 7(4):345-50. · 1.63 Impact Factor
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    ABSTRACT: Emphasis of secondary repair for unilateral cleft-lip has been placed on correction of the cleft-lip nasal deformity by translocation of the alar cartilage with its attached vestibular lining into a normal position, thereby establishing the normal vault and shape of the cartilage. We have managed cleft-lip deformities employing a modified reverse-U method. We present our modified technique and the obtained results. Eighty-nine patients with unilateral cleft-lip nasal deformity underwent surgical repair between 1998 and 2007 by one surgeon. These patients were divided into two groups based on their previous operative histories. Group A comprised 52 patients who underwent primary cheiloplasty using a modified Tajima technique. No other surgery had been performed prior to our modified reverse-U method in these cases. Group B consisted of 37 patients receiving the primary operation and/or more than one rhinoplasty at another hospital before our method was employed. The ages of our patients at the time of the secondary operation ranged from 4 to 40 years (average, 8.1 years; 4.2 years in group A and 13.4 years in group B). The follow-up period ranged from 2 to 11 years (average 7.2 years). For objective evaluation, points on the nasal dome and alar crease were measured on patient photographs. The results were retrospectively distinguished to three levels by total point score: Excellent, Good and Fair. Excellent or Good results were obtained in 74 cases, while 15 had Fair results. Eighty-one percent of all cases maintained acceptable results without relapse. Fair results were attributed to an unclear alar crease or relapse. In conclusion, rigid fixation and release of nasal cartilage are very important. We believe our modified reverse-U method to be very useful for achieving symmetry of the unilateral cleft-lip nose in the long term.
    Journal of Plastic Reconstructive & Aesthetic Surgery 12/2010; 64(6):747-53. · 1.44 Impact Factor
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    ABSTRACT: Microtia is a congenital ear hypoplasia associated with auricular defects. Conventional treatment involves implanted costal cartilage. The impact of surgical invasion and donor-site morbidity can be particularly severe in pediatric patients, and the collectable volume of autologous cartilage is limited. The authors therefore developed a new technique for microtia and applied it to treat four patients. Through the development of a multilayer chondrocyte culture system and two-stage implantation technique, the authors successfully generated human ears. In culture, the chondrocytes are expanded to a sufficiently large volume, produce rich chondroid matrix, and form immature cartilaginous tissues. In the authors' two-stage implantation, the cultured chondrocytes are injection-implanted into the lower abdomen of the patient, where the cells grow into a large, newly generated cartilage with neoperichondrium in 6 months. This cartilage is harvested surgically, sculptured into an ear framework, and implanted subcutaneously into the position of the new ear. The cultured chondrocytes formed a mature cartilage block with sufficient elasticity for use as an auricular cartilage. The formed block had the same histologic origin as elastic cartilage. The ear framework produced from this block was implanted into the auricular defect area, and an auricle with a smooth curvature and shape was subsequently configured. In the 2 to 5 years of postoperative monitoring, the neocartilage maintained good shape, without absorption. The authors' four patients are the first successful cases of regenerative surgery for microtia using cultured ear chondrocytes. The benefits of the technique include minimal surgical invasion, lower donor-site morbidity, lessened chance of immunologic rejection, and implantation stability.
    Plastic and reconstructive surgery 10/2009; 124(3):817-25. · 2.74 Impact Factor
  • Hiroko Yanaga, Keisuke Imai, Katsu Yanaga
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    ABSTRACT: Conventional treatment for nasal augmentation utilizes autologous grafts, allografts, or synthetic implants such as silicon implants. Silicon implants could protrude/expose or induce nasal bone resorption. Autologous grafts are usually associated with donor site morbidity and the volume of harvested tissue is limited. We had developed a new method for nasal augmentation using cultured autologous chondrocytes (CAC). The current report presents the results of a study using that method with a larger number of patients and an improved graft technique for the nasal tip. Approximately 1 cm2 of cartilage was harvested from the auricular concha and treated with collagenase, and then chondrocytes were obtained. In our multilayer culture system the chondrocytes formed immature cartilaginous tissues with a gelatinous chondroid matrix. They were injection-grafted into the subcutaneous pocket of the nasal dorsum. The chondrocytes with a gelatinous chondroid matrix change from a soft gel to hard neocartilage tissue within 2 to 3 weeks and then stabilize. The authors have used this procedure over a 6-year period on 75 cases: 58 secondary augmentation rhinoplasties following silicon implantation and 17 primary augmentation cases. The results have been satisfactory and long-lasting. Grafting of CAC is an optional method for nasal augmentation and could be used for a wide range of facial augmentation cases.
    Aesthetic Plastic Surgery 09/2009; 33(6):795-802. · 1.26 Impact Factor
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    ABSTRACT: New method to exercise creation of three-dimensional cartilage framework for ear by using a precise copy of the costal cartilage is presented. Precise negative impressions were taken from harvested 6th to 9th rib cartilage using molding material. Silicon-type dental impression material was injected into the negative impression to create a copy of the costal cartilage. Simulated surgical procedures were performed to evaluate this model; each step of creating three-dimensional framework for total auricular reconstruction was performed with exactly the same instrumentation for real surgery. We found that simulation of surgery was successfully performed, and created three-dimensional framework was very close to the real costal cartilage framework. By using a precise copy of the costal cartilage, simulation of creating ear framework came to a very realistic method to practice, and this method may give the "ear maker" a good opportunity to prepare for the actual surgical procedure.
    The Journal of craniofacial surgery 06/2009; 20(3):899-902. · 0.81 Impact Factor
  • Journal of Plastic Reconstructive & Aesthetic Surgery 02/2008; 61(2):225-7. · 1.44 Impact Factor
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    Burns 03/2007; 33(1):112-20. · 1.80 Impact Factor
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    ABSTRACT: The repair of a craniofacial or nose deformity requires a large volume of reconstructive material. A conventional cartilage graft does not provide a sufficient volume of reconstructive material. Therefore, augmentation of the facial form to the defect shape is quite difficult. The authors developed a new treatment method that provides a sufficiently large volume of reconstructive material and enables an easier reconstruction of the original shape. Ages of the patients ranged between 9 and 63 years. Approximately 1 cm of auricular cartilage was collected from the auricular concha. Isolated chondrocytes were cultured with autologous serum that accelerates cell proliferation. The cells were subcultured and formed a gel-form mass. This mass, together with autologous serum, was grafted (injected) on the periosteum and into the subcutaneous pocket. The volume of grafted cultured chondrocytes ranged from 1.7 to 40 cc (1 to 5 x 10(7) cells/cc). The lesion changed from soft gel form into hard cartilage tissues within 2 to 3 weeks and stabilized. Excellent or good satisfactory results were obtained in all patients and have been maintained for periods ranging from 3 to 34 months. No patient experienced absorption of cultured chondrocytes. Biopsy of the newly formed tissues showed that it was an elastic cartilage derived from the original tissue. A small number of chondrocytes obtained from a 1-cm auricular cartilage are successfully cultured into a large number of cells in a gel form. Those autologous auricular chondrocytes in a gel form allow for the repair of complicated shapes of the defect area. This technique is applicable to various treatments for craniofacial or nose deformity.
    Plastic and reconstructive surgery 06/2006; 117(6):2019-30; discussion 2031-2. · 2.74 Impact Factor
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    ABSTRACT: The aim of this study was to analyze the morphologic changes of the craniofacial skeleton in synostotic plagiocephaly after cranial distraction. Preoperative and postoperative computed tomography scans were taken, and three-dimensional reconstruction was then performed. Three measurements were obtained: intracranial volume, volume of the middle cranial fossa, and length of the zygomatic arch. Intracranial volume reached values that were normal for a 2-year-old child postoperatively, and the discrepancy between left and right half volumes decreased over time. The discrepancy of the volume of the middle cranial fossa also decreased after surgery, and the asymmetry of the zygomatic arch improved significantly. Based on these objective findings, the authors believe that cranial distraction could favorably affect craniofacial dysmorphology of synostotic frontal plagiocephaly.
    Journal of Craniofacial Surgery 08/2005; 16(4):688-93. · 0.69 Impact Factor
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    ABSTRACT: A new method of nasal augmentation has been developed, in which cultured autologous chondrocytes are transplanted. Using biotechnology, a piece of the choncha cartilage 1 cm2 is cultured into a gel-type mass of chondrocytes, which then is transplanted by injection into a surgically created subperiosteal skin pocket on the nasal dorsum. The augmented nose is taped and protected for 1 week. The grafted chondrocytes develop into mature cartilaginous tissue after approximately 1 month. This method was used in eight cases of nasal augmentation, and one case of chin augmentation (performed simultaneously), and one case of depressed deformity on the forehead. The results obtained by this method to date have been satisfactory after a follow-up time of 6 to 24 months. The authors believe that this method may at least partially be able to replace silicone implantation for nasal augmentation.
    Aesthetic Plastic Surgery 01/2004; 28(4):212-21. · 1.26 Impact Factor
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    ABSTRACT: The authors describe their experience in remodeling the shape of the cranium in children with craniosynostosis by using gradual distraction. In half of the cases, a new distraction device developed by the authors was used. Twenty children with craniosynostosis underwent frontoorbital advancement and cranial remodeling assisted by gradual distraction. There were five children with brachycephaly, two with oxycephaly, five with scaphocephaly, two with plagiocephaly, one with combined scaphocephaly and plagiocephaly, and five with trigonocephaly. Four cases were syndromic and 16 were nonsyndromic. The patients ranged in age from 3 to 50 months (mean 14.5 months) at the first surgery. Simulated surgery was first performed on a three-dimensional solid model made of polyurethane, which accurately represented cranial flexibility, to determine the most favorable osteotomy line. Distraction was initiated 1 week postoperatively. The speed and extent of advancement (maximum extension 45 mm) were predetermined on the basis of previously reported criteria and the results of simulated surgery. Postoperatively, the cranial configuration was favorable in all cases. Spontaneous remodeling of irregularities and/or gaps apparent after distraction was found to occur 2 to 5 months after removal of the distraction devices, especially in patients with trigonocephaly or scaphocephaly. No major perioperative complication was observed in any patient. There were minor complications in six of the first 10 cases, including exposure of the device, shaft slippage, and fluid discharge. A new device was developed and used on the last 10 patients treated; it successfully eliminated device exposure and shaft slippage. A 3-year follow-up review confirmed that there was no relapse of advanced bones. Highly satisfactory results were achieved in cases of both syndromic and nonsyndromic craniosynostosis when gradual distraction was performed.
    Journal of Neurosurgery 05/2002; 96(4):654-9. · 3.15 Impact Factor