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Dive into the research topics where Kohei Kanaya is active.

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Featured researches published by Kohei Kanaya.


Transplantation | 2003

Combined gene therapy with adenovirus vectors containing CTLA4Ig and CD40Ig prolongs survival of composite tissue allografts in rat model.

Kohei Kanaya; Yoshihiko Tsuchida; Manabu Inobe; Masaaki Murakami; Toshiaki Hirose; Shigeyuki Kon; Satoshi Kawaguchi; Takuro Wada; Toshihiko Yamashita; Seiichi Ishii; Toshimitsu Uede

Background. The blockade of costimulatory signal pathway by anti-CD40 ligand antibody or cytotoxic T lymphocyte antigen 4 immunoglobulin (CTLA4Ig) prolongs allograft survival in various vascularized organ transplantations. Because of the short half life of these agents, repeated administration of proteins is required to achieve significant graft survival. Furthermore, there is limited information regarding the effect of cosimulatory blockade on the survival of composite tissue allografts. Therefore, we examined the effect of adenovirus-mediated gene transfer of CTLA4Ig or CD40Ig gene or both in composite tissue allotransplantation. Methods. The hind limbs removed from male ACI rats (RT1a) were transplanted into female Lewis rats (RT11) heterotopically. The recombinant adenovirus carrying CTLA4Ig (AxCTLA4Ig) or CD40Ig (AxCD40Ig) was intravenously administered after limb transplantation. Results. Limb allograft survival was significantly prolonged by either AxCTLA4Ig or AxCD40Ig treatment at 1×109 plaque forming unit (mean survival time [MST] of 39.4±6.0 and 13.0±2.9, respectively) compared with the adenovirus vector containing &bgr;-galactosidase-treated group (MST of 4.8±0.8). Combination of AxCTLA4Ig and AxCD40Ig led to significant prolongation of graft survival (MST of 49.2±6.6). Serum levels of CD40Ig were higher in rats treated with combination therapy than those treated with AxCD40Ig alone, whereas the serum levels of CTLA4Ig in rats treated with AxCTLA4Ig alone and AxCTLA4Ig and AxCD40Ig combined were very similar. Conclusion. This study indicates that an adenovirus-mediated gene therapy of CTLA4Ig or CD40Ig has a therapeutic potential for preventing rejection in composite tissue transplantation. Furthermore, a combination therapy of AxCTLA4Ig and AxCD40Ig was even more effective in preventing acute rejection and prolonging the survival of allografted limbs without apparent complication.


Journal of Pediatric Orthopaedics | 2001

Correlation between progression of spinal deformity and pulmonary function in Duchenne muscular dystrophy

Toshihiko Yamashita; Kohei Kanaya; Kazutoshi Yokogushi; Yuka Ishikawa; Ryoji Minami

The purpose of this study was to investigate how age at and value of the plateau of vital capacity (VC plateau) correlate with the severity of the progression of spinal deformity in patients with Duchenne muscular dystrophy (DMD). Changes in spinal deformity and pulmonary function in 36 DMD patients were examined in a retrospective longitudinal study. Patterns of progression of spinal deformity were classified into three types according to Odas classification. Of the 32 patients who showed spinal deformity, six were classified as type 1, 19 as type 2, and seven as type 3. The correlation between the patterns of progression of spinal deformity and the VC plateau was examined using a discriminant analysis. Rapid and severe progression of spinal deformity could be expected in patients whose VC plateau was less than 1,900 mL and in those in which it occurred before age 14 years. Thus VC plateau may be an indicator of the severity of the progression of spinal deformity in DMD patients.


Spine | 2001

Prediction of progression of spinal deformity in Duchenne muscular dystrophy: a preliminary report.

Toshihiko Yamashita; Kohei Kanaya; Satoshi Kawaguchi; Takanori Murakami; Kazutoshi Yokogushi

Study Design. Discriminatory power was statistically estimated for multiple combinations of risk indicators for the progression of spinal deformity in Duchenne muscular dystrophy (DMD). Objective. To differentiate DMD cases in which spinal deformity will rapidly and severely progress from those with lesser progression of spinal deformity. Summary of Background Data. Early surgical intervention using instrumentation has recently been advocated for DMD patients to prevent the progression of spinal deformity. However, early determination of cases needing surgical intervention is difficult because of variations in the severity of the clinical courses of DMD patients. Methods. Charts and spinal radiographs of 12 DMD patients were reviewed retrospectively. Patterns of progression in spinal deformity were classified into three types according to Oda’s classification. Discriminant analysis was conducted to categorize the patients into either a severe progression group (type-1 and type-2 patients) or a less severe progression group (type-3 patients and patients without spinal deformity) on the basis of four predictors: 1) vital capacity at the age of 10 years, 2) the age at which ambulation ceased, 3) curve pattern of spinal scoliosis, and 4) Cobb angles of spinal scoliosis at the age of 10 years. Results. Eleven of the twelve DMD patients showed spinal deformity. Three were classified as type 1, six were classified as type 2, and two were classified as type 3. The remaining patient showed no spinal deformity. Multiple discriminant analysis correctly predicted the severity of the clinical course of 91.7% of the DMD patients. Vital capacity at age 10 was found to be the strongest predictor among the variables. Conclusions. Through multiple discriminant analysis, the clinical course of spinal deformity in DMD patients was correctly predicted in 92% of subjects. This method would be useful to determine early which DMD cases need surgical intervention for treatment of spinal deformity.


Journal of Hand Surgery (European Volume) | 2013

The Thompson Procedure for Chronic Mallet Finger Deformity

Kohei Kanaya; Takuro Wada; Toshihiko Yamashita

PURPOSE To evaluate the outcomes of the Thompson procedure for chronic mallet finger deformity and review the utility of this procedure. METHODS Seven cases of chronic mallet finger with a swan neck deformity were treated by the Thompson procedure. Ranges of motion for the distal interphalangeal (DIP) and proximal interphalangeal (PIP) joints were measured, and complications were investigated at the final examination. Patients were evaluated using the criteria reported by Abouna and Brown. RESULTS Four patients were men, and 3 were women. The average age at the time of surgery was 44 years (range, 25 to 71 y). The middle finger was affected in 4 cases, and the index, ring, and small finger were involved in 1 case each. The average extensor lag on the DIP joint was 42° (range, 35° to 50°). All cases were treated with the Thompson procedure. The swan neck deformity was corrected in all cases. The average motion at the final examination was -4° (range, -30° to 0°) in extension and 91° (range, 85° to 110°) in flexion for the PIP joint and -5° (range, -10° to 0 °) in extension and 63° (range, 45° to 85°) in flexion for the DIP joint. A buttonhole deformity and a dimple at the proximal tied end of the graft were seen in 1 case. Assessment by the criteria of Abouna and Brown revealed that 6 of 7 patients were categorized as cured and one as improved. No patient was categorized as unchanged. CONCLUSIONS The procedure provides a predictable method for correcting loss of DIP joint extension with or without PIP joint hyperextension. We believe that the Thompson procedure is an effective technique for the salvage, following failed treatment, of a closed mallet injury with an associated swan neck deformity.


Journal of Hand Surgery (European Volume) | 2014

Total Dorsal Capsulectomy for the Treatment of Mucous Cysts

Kohei Kanaya; Takuro Wada; Kousuke Iba; Toshihiko Yamashita

PURPOSE To describe the technique of total dorsal capsulectomy alone for mucous cysts of the distal interphalangeal (DIP) joint and evaluate its outcomes and complications. METHODS Nineteen patients (18 women and 1 man) with 19 mucous cysts were treated by a total dorsal capsulectomy without cyst excision or osteophyte removal. The average age at surgery was 63 years. The thumb was involved in 4 patients, index finger in 1, middle finger in 7, ring finger in 4, and little finger in 3. Twelve patients had nail deformities associated with the mucous cyst. The average period of postoperative follow-up was 26 months. The dorsal half of the DIP joint capsule was resected with a punch and curette. The cyst and osteophytes were left intact. RESULTS The average preoperative range of motion for the DIP joint was from 10° of extension to 45° of flexion. Radiographs showed osteophytes at the DIP joint in all affected digits. After surgery, all cysts disappeared at an average of 3 weeks. There was no recurrence at the time of final follow-up. All nail deformities had resolved at an average of 5 months after surgery. The average motion for the DIP joint at the time of final follow-up was from 8° of extension to 56° of flexion. There were no acquired nail deformities or other complications. CONCLUSIONS A total dorsal capsulectomy alone was a simple treatment for mucous cysts and did not lead to any recurrence. TYPE OF STUDY/LEVEL OF EVIDENCE Therapeutic IV.


Journal of Shoulder and Elbow Surgery | 2016

Long-term results after a free vascularized adipofascial graft for congenital proximal radioulnar synostosis with an average follow-up of 10 years: a series of four cases

Kohei Kanaya; Kousuke Iba; Toshihiko Yamashita

BACKGROUND The aim of this study was to observe the long-term and chronologic changes in clinical and radiologic findings after a free vascularized adipofascial graft interposition with radial osteotomy for congenital proximal radioulnar synostosis (PRUS). METHODS Six forearms in 4 patients with congenital PRUS who underwent a free vascularized adipofascial graft interposition combined with radial osteotomy were followed up for an average of 10 years (8-12 years) postoperatively. Extension and flexion angles of the elbow and pronation and supination angles of the forearm as well as radiographs were evaluated preoperatively and throughout the postoperative follow-up period. RESULTS The average extension/flexion angles of the elbow and the average pronation/supination angles of the forearm were 3°/130° and 14°/- before surgery, -4°/135° and 39°/23° at 1 year after surgery, 6°/138° and 44°/30° at 3 years after surgery, and -2°/139° and 35°/7° at the time of the final follow-up, respectively. Final radiographs showed hypertrophy of the radial head in 4 patients, dislocation of the radial head in 2 patients, and deformity of the radial head in 1 patient. CONCLUSIONS Extension and flexion angles of the elbow in patients with congenital PRUS were constant and the average range of pronation was relatively well maintained throughout the postoperative period, but the average range of supination decreased by 16° from 1 year postoperatively to the time of the final follow-up.


Journal of Orthopaedic Science | 2015

Effect of simultaneous stretching of the wrist and finger extensors for lateral epicondylitis: a gross anatomical study of the tendinous origins of the extensor carpi radialis brevis and extensor digitorum communis

Rikiya Shirato; Takuro Wada; Mitsuhiro Aoki; Kousuke Iba; Kohei Kanaya; Mineko Fujimiya; Toshihiko Yamashita

BackgroundPulling the wrist into flexion with the elbow in extension and forearm in pronation has been used as the stretching technique of wrist extensors for lateral epicondylitis. Simultaneous stretching of the fingers in addition to the wrist flexion has also been applied. However, the mechanism of this simultaneous stretching has not been clarified. This study is designed to clarify the mechanism underlying this simultaneous stretching technique based on the anatomical features of the origins of the extensor carpi radialis brevis (ECRB) and extensor digitorum communis (EDC).MethodsThirty-nine arms from formalin-embalmed Japanese human specimens were dissected. The features of the origins of the ECRB and EDC were macroscopically observed, and the locations of each origin on the lateral epicondyle were measured.ResultsThe ECRB had a long and wide, purely tendinous origin which originated from the anterior slope of the lateral epicondyle. The tendinous origin of the index finger of the EDC (EDC-IF) arose from the posterior aspect of the ECRB tendinous origin, with a coexisting muscular portion observed at the level of the proximal forearm. The middle finger of the EDC (EDC-MF) had a short tendinous origin with an associated muscular portion and originated proximo-laterally to the origin of the ECRB on the lateral epicondyle. In addition, the muscular origin of the EDC-MF arose on the superficial and posterior aspect of the ECRB tendinous origin. In contrast, the ring and little fingers of the EDC originated from the tendinous septum of the extensor digiti minimi and extensor carpi ulnaris, and had no connection with the ECRB tendinous origin.ConclusionsOn the basis of our anatomical findings, simultaneous stretching of the wrist extensors by wrist, index and middle fingers flexion could provide stretching force to both the tendinous origins of the ECRB and EDC through the EDC-IF and EDC-MF.


Journal of Reconstructive Microsurgery | 2014

Innervated thenar pedicle flap with the palmar cutaneous branch of the median nerve for treating a thumb pulp defect: a case report.

Kohei Kanaya; Takuro Wada; Kosuke Iba; Toshihiko Yamashita

A 51-year-old male plumber with a thumb pulp defect was treated with a reversed innervated thenar pedicle flap. The flap was based on the radial digital artery originating from the princeps pollicis artery with the palmar cutaneous branch of the median nerve. The flap survived and achieved good innervation with a moving 2-point discrimination of 6 mm at 12 months after surgery. This flap is indicated for patients who hesitate to have tissue taken from the foot. We believe that this flap is a feasible option for reconstructing thumb pulp defects.


Journal of Hand Surgery (European Volume) | 2013

Reconstruction of Chronic Thumb Metacarpophalangeal Joint Radial Collateral Ligament Injuries With a Half-Slip of the Abductor Pollicis Brevis Tendon

Kousuke Iba; Takuro Wada; Tetsuro Hiraiwa; Kohei Kanaya; Gosuke Oki; Toshihiko Yamashita

PURPOSE To evaluate a reconstructive method for chronic radial collateral ligament (RCL) injuries of the thumb metacarpophalangeal (MCP) joint using a combination of RCL advancement and the transfer of a half-slip of the abductor pollicis brevis tendon. METHODS Eight patients (4 male and 4 female; mean age, 25 y) with chronic RCL injury of the thumb MCP joint were enrolled. All patients were referred to our institution because of continuing pain and instability on the radial side of the MCP joint when grasping or pinching objects. The mechanism of the injury was adduction stress to the thumb during sporting activities in 5 patients, a heavy object falling on the thumb in 1, and a fall in 2. The mean duration from RCL injury to surgery was 20 weeks. The average postoperative follow-up was 51 months. We evaluated postoperative outcomes including pain, range of motion of the thumb MCP joint, grip strength, key pinch strength, Disabilities of the Arm, Shoulder, and Hand score, and ability to return to preinjury work or sporting activities. RESULTS No patients demonstrated continuing symptoms, and the MCP joint was stable after surgery. Postoperative grip and pinch strength (37 and 6.3 kg, respectively) were increased compared with preoperative values (34 and 3.9 kg, respectively). All patients returned fully to their preinjury work or sporting activities within 6 months after surgery. Although postoperative flexion was decreased by an average of 6°, no patients noted functional deficiency. CONCLUSIONS We recommend the reconstructive method of RCL advancement and transfer of a half-slip of the abductor pollicis brevis tendon to alleviate pain and improve grip and pinch strength in chronic RCL injuries of the thumb MCP joint.


Hand Surgery | 2010

SCAPHOID DISLOCATION ASSOCIATED WITH AXIAL CARPAL DISSOCIATION DURING VOLAR FLEXION OF THE WRIST: A CASE REPORT

Kohei Kanaya; Takuro Wada; Toshihiko Yamashita

We present the first report of a patient with an isolated scaphoid dislocation with axial carpal dissociation sustained during volar flexion of the wrist. The scaphoid was dislocated to the radial side of the radial styloid process and was slightly shifted to the dorsal side. It was shown that the position of the wrist played an irrelevant role for occurring scaphoid dislocation.

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Takuro Wada

Sapporo Medical University

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Kousuke Iba

Sapporo Medical University

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Satoshi Isogai

Sapporo Medical University

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Hikono Aiki

Sapporo Medical University

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Satoshi Kawaguchi

Sapporo Medical University

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Masamichi Usui

Sapporo Medical University

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Aki Ishikawa

Sapporo Medical University

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