Published papers

There are no procedures available to reconstruct the normal cranial shape irrespective of the type of cranial deformity with minimal patient stress and morbidity. To achieve dynamic total skull remodeling, we considered a new remodeling concept and developed a new procedure by combining morcellation craniotomy and distraction osteogenesis, termed the MoD procedure, and designed a distraction device, namely the angle variable distraction (AVD) system. Between 2000 and 2009, we treated 41 patients with craniosynostosis (28 and 13 cases of isolated and syndromic craniosynostosis, respectively) by using the MoD procedure with the AVD system. Compared with the conventional methods, the mean operative time was significantly shorter, and the mean transfusion volume was significantly less for the MoD procedure. In all the patients, good cranial shape and adequate cranial volume were achieved without serious complications. In conclusion, the MoD procedure with the AVD system is safe, effective, and reliable for dynamic total skull remodeling with minimal morbidity. It could be used to improve the previous surgical concepts for treating craniosynostosis.

This report describes a pitfall of reconstruction for severe enophthalmos after time has passed following traumatic injury. In severe cases, hypoglobus may be refractory to reconstructive surgery. The posterior wall of the maxillary sinus is sometimes implicated in severe enophthalmos. Thus, we considered that reconstruction of this posterior wall is critical for improvement in hypoglobus. In addition, a satisfactory contour and improvement in hypoglobus were maintained postoperatively.

This report addresses a pitfall of decompression for severe exophthalmos. In mild cases, removal of the orbital floor is an effective treatment, but in severe cases, the results of this approach are sometimes unsatisfactory, and only decompression is necessary. In these cases, orbital decompression in 3 areas including the medial wall, the lateral wall, and the orbital floor is usually performed. A 5.0-mm mean reduction in exophthalmos is observed, but more reduction is difficult to achieve.We considered the possibility that removal of the posterior wall of the maxillary sinus is critically important to achieving greater recovery. It is proposed that this technique is effective in creating about 10 mm of improvement for severe exophthalmos.

Vasculogenesis describes the process of de novo vessel formation from vascular precursor cells. Although formation of the first major vessels, such as the dorsal aorta and cardinal veins, occurs during embryonic vasculogenesis, the contribution of precursor cell populations to postnatal vessel development is not well understood. Here, we identified a novel population of postnatal vascular precursor cells in mice. These cells express the Schwann cell protein myelin protein zero (Po) and exhibit a CD45-CD31-VEcad-c-kit+CXCR4+ surface phenotype. Po+ vascular precursors (PVPs) are recruited into the growing vasculature, and comprise a minor population of arterial endothelial cells in adult mice. Recruitment of PVPs into growing vessels is mediated by CXCL12-CXCR4 signaling, and is enhanced during vascular expansion induced by Notch inhibition. Po-specific ablation of Flk1, a receptor for VEGF, results in branching defects and insufficient arterial patterning in the retina, as well as reduced neovascularization of tumors and ischemic tissues. Thus, in postnatal mice, although growing vessels are formed primarily by angiogenesis from preexisting vessels, a minor population of arterial endothelia may be derived from tissue-resident vascular precursor cells.

The V-Y advancement flap is one of the most frequently used methods in plastic surgery. But the movement of the flap is sometimes disrupted by tension, and there are various practical methods to release the tension of the flaps. We investigated a new method modifying V-Y advancement, in which we add a slit-cut in the middle of the flap, and insert a triangle shaped skin surplus into the space which is usually trimmed. We named this method the "Clione Method", because it resembles a clione, a cold-ocean dwelling creature. We used this method in 7 cases (2 cases are presented in this article), which required large tissue reconstruction after radical resection of tumors or scars. In all cases, the "Clione Method" was useful for covering the defects with less tension at the tip of the flaps, and all the flaps successfully survived. The "Clione Method" has the following advantages: 1) It does not leave complicated scarring on the flap which directly covers the defect, 2) The skin surplus which is trimmed and discarded is reused naturally, 3) The sutured line does not become straight eventually, which can prevent scar contracture, and 4) The technique is simple. On the other hand, an additional cut must be made on the flap, and thus the method should be used only when the flap is not undermined beneath the flap, or when there is sufficient blood supply under the flap.

Hair is one of the smallest organs, but has many important functions to mammals. Hair morphogenesis occurs through the reciprocal exchange of epithelial and mesenchymal signals. There are some reports about the expression of laminin-511 and -332 during hair morphogenesis, but are no reports of the chronological expression and function of laminin-511 and its counter regulator laminin-332 during hair morphogenesis. Our results of immunoblotting revealed that laminin-332 proteins were detected at stage 0 and downregulated during stage 1 to stage 2, and then recovered at stage 3. However, laminin α5 expression was constant throughout stages 0-3. According to the results of semi-quantitative RT-PCR, the mRNA expression of all laminin-332 subunits increased gradually from stage 0 to stage 2, while the mRNA expression of all laminin-511 subunits remained constant from stage 0 to stage 3. Our results suggest that the proper expression of laminin-332 and laminin-511 may regulate appropriate hair morphogenesis.

Objective The present study elucidates the relationship between the locations of rib defects and loss of respiratory function. Methods Ten sets of three-dimensional finite element models were produced from computed tomography data of 10 persons and categorized as normal type models. These models were modified by removing part of the ribs, and the resultant models were categorized as defect type models. Varying the location of the defects, six types of defect model were produced from each of the 10 normal models; the defects were made on the anterior-superior, anterior-inferior, lateral-superior, lateral-inferior, posterior-superior, and posterior-inferior regions of the thorax. To simulate respiration, contracture forces were applied to nonlinear springs modeling respiratory muscles for each of the normal and defect models. Difference in volume of the thoracic cavity between inspiration and expiration phases was viewed as the indicator of respiratory function and was defined as ΔV. The values of ΔV were compared between normal type models and their corresponding defect type models. Results Among the six types of defect, the degree of functional loss was greatest with those defects on the lateral-inferior part of the thorax, where ΔV of the affected side hemithorax drops to 38 to 45% of normal values, whereas ΔV was 62 to 88% with other defect models. Conclusion Thoraces that have defects on their lateral-inferior regions present lower respiratory functioning than thoraces with other defect locations. Hence, in treating clinical cases where defects are expected to occur in this region, effort should be made to minimize the area of the defect.

An 81-year-old male presented with a soft mass on his neck noted in the supine position. After undergoing an operation for an inguinal hernia, the mass was noted to persist regardless of the patient's position. Computed tomography and magnetic resonance imaging revealed phlebectasia of the external jugular vein with an associated thrombosis. Under general anesthesia, the external jugular vein was ligated and removed, along with the thrombus. A histological section revealed that the tunica media of the external jugular vein was absent, and the smooth muscle layer and elastic fibers were attenuated in the fusiform area of the vein. Due to the risk of propagation of the clot and pulmonary embolism, resection of the external jugular vein is advised in cases of phlebectasia of the external jugular vein.

"Collapsed nasal tip," one of the most characteristic features of cleft lip nose, resembles the effect of pushing the nose tip with a finger and is especially noticeable among Asians. The authors examined a rhinoplasty technique for improving collapsed nasal tip. Using an intercartilaginous incision, the distal nasal framework, including the alar cartilages, and the caudal septum were widely exposed. A septal extension graft was fixed to the caudal septum, and the alar cartilages were precisely sutured to the extension graft using markings transferred to the extension graft. This procedure was applied to 15 Asian rhinoplasties, with all patients having substantial improvement in the shape of their nasal tip. Comparing those with and without a history of rhinoplasty, effecting a projection of the nasal tip was more difficult in patients with a history of previous rhinoplasties. The advantages of this technique include inconspicuous scarring and versatility in the modification of the nasal tip. Rhinoplasty during the growth period should be planned with consideration of future augmentation rhinoplasties.

Pectus excavatum-commonly known as funnel chest-is one of the most frequently observed congenital deformities, in which the patients' thoraces present concavity. This paper presents our original hypothesis that the abnormal positioning of the major pectoral muscle can be a potential factor in the occurrence of pectus excavatum, and evaluates the validity of the hypothesis by performing an anatomical and a biomechanical study. An anatomical study on clinical cases revealed that the major pectoral muscle tends to be positioned more superiorly in pectus excavatum patients than in normal persons. The biomechanical study, using three-dimensional finite element dynamic simulation, revealed that the major pectoral muscle functions to elevate the sternum and that the elevating effect is reduced when the muscle is located at superior regions on the thoracic wall. These findings support our hypothesis that the abnormal position of the major pectoral muscle is a potential causative factor for pectus excavatum. This hypothesis suggests that, during surgical correction of pectus excavatum with an open approach, surgeons should reposition the major pectoral muscle to its correct anatomical position to avoid recurrence.

Treatment of calvarial defects has remained a challenge in reconstruction surgery, especially because of infection at these sites. We produced a bactericidal biomaterial for treating infected bone defects by using calcium phosphate bone cement mixed with antibiotics. We evaluated the usefulness of this material mixed with the antibiotic vancomycin in a cranium-infected rat model. The concentration of vancomycin used was 5.0 wt%, as reported in our previous study. In order to establish the rat model, a cranium defect (diameter, 5 mm) was made that was infected with methicillin-resistant Staphylococcus aureus (MRSA). Thirty-six rats were divided into 6 groups depending on whether an autologous graft or bone cement with or without antibiotic was used for the defect. After 1 and 4 weeks, abscess formation was checked, tissue bacterial counts were determined, and pathological examination was performed. At both 1 and 4 weeks, no MRSA was detected on tissue bacterial culture or pathological examination in groups that received bone cement with antibiotics. In groups that received bone cement without antibiotic, MRSA was detected, and the bone cement had compromised and disintegrated into several slices. In conclusion, bone cement that contains antibiotics appears to be effective not only for reconstruction in cases of cranial defect, but also in terms of preventing infection.

Background: As the antihelix is created in the operation for prominent ear, the helix often presents irregularities. This biomechanical study aims to elucidate effective techniques to prevent these irregularities. Methods: Finite element models were produced simulating 10 prominent ears. The scaphas of the 10 models were thinned to simulate scoring or abrasion of the cartilage. The thinning was conducted in four fashions. In the first group, no thinning was conducted (Non-Scoring Models); in the second group, the upper half of the scapha was thinned (Upper-Scoring Models); in the third group, the lower half of the scapha was thinned (Lower-Scoring Models); in the fourth group, the whole scapha was thinned (Whole-Scoring Models). Mattress sutures were applied to create the antihelix to simulate Mustarde's in-suture technique. Thereafter, transformation of the helix's contour was evaluated. Results: Irregularity developed on the upper region of the helix with Non-Scoring and Lower-Scoring Models; the degree of the upper-region's irregularity was reduced with Upper-Scoring Models and Whole-Scoring Models. Although the edge of the helix moved in the posterior-medial direction with other type models, it moved in the anterior direction with Whole-Scoring Models. Conclusion: Irregularity of the upper region of the helix can be prevented by performing scoring or abrasion of the upper part of the scapha. The prominence of the helix and width of the auricle are adjustable by varying the areas of the scapha receiving scoring or abrasion. These findings are useful in improving operative outcomes in the treatment of prominent ears.

Reconstruction for fingertip defects categorized as Type 3 and Type 4 in Allen's classification is challenging, because surgeons need to reconstruct not only the pulp but also great parts of the distal phalangeal bone. This paper introduces an original technique for the reconstruction of defects of these types. The defects of seven fingers (two small fingers and five index fingers) of seven patients (three males and four females; aged 14-44 years) were repaired. After the fingertip is divided in a fish-mouth fashion to expose the stump of the distal phalangeal bone, a curved block of hydroxyapatite is grafted to fill the phalangeal defect and straighten the nail bed. A rectangular flap is raised from the dorsal side of the neighbouring finger in the region between the PIP and DIP joints. Then the fish-mouth region carrying the grafted hydroxyapatite is covered with the rectangular flap to reconstruct the pulp. The rectangular cross-finger flap is separated 3-4 weeks postoperatively. In all seven cases, the flap survived completely. Infection developed in no case. In all cases, aesthetic appearance of the pulp and nail presented improvement, satisfying the patients. Combined usage of hydroxyapatite and a cross-finger flap from the neighbouring finger is an effective method for the reconstruction of type 3 and type 4 defects in Allen's classification.

Dysregulation in the RAS signaling cascade results in a family of malformation syndromes called RASopathies. Meanwhile, alterations in FGFR signaling cascade are responsible for various syndromic forms of craniosynostosis. In general, the phenotypic spectra of RASopathies and craniosynostosis syndromes do not overlap. Recently, however, mutations in ERF, a downstream molecule of the RAS signaling cascade, have been identified as a cause of complex craniosynostosis, suggesting that the RAS and FGFR signaling pathways can interact in the pathogenesis of malformation syndromes. Here, we document a boy with short stature, developmental delay, and severe craniosynostosis involving right coronal, bilateral lambdoid, and sagittal sutures with a de novo mutation in exon1 of SHOC2 (c.4A>G p.Ser2Gly). This observation further supports the existence of a crosslink between the RAS signaling cascade and craniosynostosis. In retrospect, the propositus had physical features suggestive of a dysregulated RAS signaling cascade, such as fetal pleural effusion, fetal hydrops, and atrial tachycardia. In addition to an abnormal cranial shape, which has been reported for this specific mutation, craniosynostosis might be a novel associated phenotype. In conclusion, the phenotypic combination of severe craniosynostosis and RASopathy features observed in the propositus suggests an interaction between the RAS and FGFR signaling cascades. Patients with craniosynostosis in combination with any RASopathy feature may require mutation screening for molecules in the FGFR-RAS signaling cascade.