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Biomedical subjects

Atsushi Seichi

Publications and source records attributed to Atsushi Seichi.

At least 19 recordsLinked to original sources
PubMed2006

Fusionless surgery for scoliosis: 2-17 year radiographic and clinical follow-up.

STUDY DESIGN: Descriptive case series. OBJECTIVE: To determine whether fusionless, multiple vertebral wedge osteotomy can safely obtain correction of the deformity with adolescent idiopathic scoliosis (AIS). SUMMARY OF BACKGROUND DATA: To our knowledge, no such attempts to manage the AIS with fusionless, vertebral osteotomies have been reported. METHODS: A total of 20 consecutive patients were treated since 1987. Deformity correction, complications, respiratory function, and patient-oriented outcome were investigated. RESULTS: There were 20 patients (17 females and 3 males), including 19 with idiopathic and 1 with syringomyelia scoliosis, who underwent surgery at an average age of 16.4 years and were followed for 8.9 years (range 2-17) on average. There were no neurologic complications. One superficial wound infection necessitated debridement. There were 2 patients converted to posterior instrumentation surgery because of deterioration of the deformity. The average Cobb angle of 64.0 degrees before surgery was corrected to 48.2 degrees at 8.9 years after surgery. Decline of the pulmonary function test after surgery was not statistically significant. The patients' responses to questions about function and pain were favorable. CONCLUSION: Deformity with AIS was safely corrected with fusionless, multiple vertebral wedge osteotomy.

Adolescent↗
PubMed2006

Prognostic factors for patients with spinal metastases from lung cancer.

STUDY DESIGN: We conducted a retrospective study to identify prognostic factors of patients with spinal metastases from lung cancer. OBJECTIVE: To provide clinical data with strong association to the prognosis and to propose criteria determining indication of operation for spinal metastases. SUMMARY OF BACKGROUND DATA: To make a proper selection of patients for whom surgery is indicated, forecasting short-time survival after spinal metastases is very important. In the past, there has been no report of prognostic factors of patients with such metastases from this cancer. METHODS: This study included 114 patients with spinal metastases of lung cancer. Tumors were histologically categorized as non-small cell lung cancer (NSCLC) in 94 patients and small cell lung cancer (SCLC) in 20 patients. We investigated prognostic factors after spinal metastases using Cox comparative hazard model and a preoperative prognostic score proposed by Tokuhashi. We also investigated the patients who underwent operation for spinal metastases from lung cancer in our hospital. RESULTS: Multivariate analysis showed that the significant prognostic factors for survival after spinal metastases from NSCLC were performance status (PS), Ca, Alb. Among SCLC patients, Ca, Alb, and a history of chemotherapy were significant (P < 0.05) in univariate analysis. The score of Tokuhashi was not correlative to the survival period. Among the operated patients, postoperative PS was significant for the period of postoperative survival. CONCLUSION: PS, Ca, and Alb in NSCLC and Ca, Alb, and a history of chemotherapy in SCLC are useful for determining an indication of operation for spinal metastases from lung cancer.

Activities of Daily Living↗
PubMed2006

Neurologic level diagnosis of cervical stenotic myelopathy.

STUDY DESIGN: A cross-sectional analysis. OBJECTIVE: To elucidate the accuracy of neurologic level diagnosis of cervical stenotic myelopathy. SUMMARY OF BACKGROUND DATA: Neurologic level diagnosis in cervical myelopathy has not been well established. METHODS: A total of 106 patients with cervical stenotic myelopathy, with a single-level intramedullary high-intensity area confirmed on both preoperative and postoperative T2-weighted magnetic resonance imaging (MRI), were included in this study. We performed a level diagnosis on the basis of neurologic signs (the uppermost muscle with weakness, diminished or exaggerated deep tendon reflex, the uppermost level of sensory disturbance of the upper extremities) and compared it with a level diagnosis made by T2-weighted MRI. The sensitivity, specificity, and accuracy of neurologic signs on our index corresponding to each intervertebral level were calculated. RESULTS: The averages of sensitivity, specificity, and accuracy were 42%, 80%, and 70%, respectively, in the uppermost muscle with weakness, 66%, 89%, and 83% in deep tendon reflex, and 74%, 91%, and 87% in the sensory disturbance area. The positive and negative predictive values were 40% and 91%, respectively, in the uppermost muscle with weakness, 66% and 89% in deep tendon reflex, and 74% and 91% in the sensory disturbance area. Accuracy of a diagnosis based on muscle weakness was less high, the reason being that in many patients, the uppermost muscle with weakness was extensor digiti communis or the intrinsic muscles of the hands, and this led to a lower sensitivity. CONCLUSIONS: The average accuracy of neurologic level diagnosis based on the index we proposed was > or =70%. The level diagnosis by a sensory disturbance area showed the highest accuracy (87%).

Adult↗
PubMed2006

Incidence and prognostic factors of Japanese breast cancer patients with bone metastasis.

BACKGROUND: Few previous studies have analyzed the incidence of bone metastases in a defined population of Japanese breast cancer patients and their prognosis after chemotherapy. METHODS: This is a retrospective cohort study. We investigated 695 patients who underwent surgery for breast cancer. The strategy of adjuvant therapy was as follows. Patients with both estrogen receptors (ERs) and progesterone receptors (PgRs) had endocrine therapy as initial adjuvant therapy (n = 239). Patients with neither ERs nor PgRs had chemotherapy. When metastasis to other organs, including bone, was identified, patients received chemotherapy. The survival rates after surgery and after the onset of bone metastasis, as well as the incidence of bone metastasis, were calculated. We also evaluated the prognostic and predictive factors. RESULTS: Bone metastases developed in 148 of 695 patients. All 148 received chemotherapy, and 121 of them developed spinal metastases. The 5-year survival rate after bone metastases was 26.1%. Prognostic factors for bone metastases were visceral metastases and PgR status. Cord compression was observed in 17 of the 148 patients, with the thoracic spine being the most common. The 1-year survival rate for patients with bone metastases who received chemotherapy was 66.3%, whereas that of patients with paralysis after spinal metastases was 17.6%. Within 6 months of the development of spinal cord compression, 70.6% of the patients died. CONCLUSIONS: We reported the incidence and prognostic factors for a defined population of Japanese breast cancer patients with bone and spinal metastases. Our results suggest that the expected survival time for patients with paralysis who received adequate endocrine therapy or chemotherapy is generally poor. However, to detect a predictive factor of long survival after paralysis and establish the indications for surgery, a comparative study among large groups of patients with paralysis and with different backgrounds is necessary.

Adult↗
PubMed2006

Age-related changes in histogram pattern of anterior horn cells in human cervical spinal cord.

The purpose of the present study was to clarify age-related changes in histograms of spinal anterior horn cells. The study examined Rexed lamina IX of the C7 spinal cord segment in 22 men who had died of non-spinal disease (age range, 0-85 years). First, we confirmed that the size of nucleoli exhibited a linear relationship to the diameter of spinal anterior horn cells by preparing histograms of nucleoli. Second, this formula was used to create histograms of cervical anterior horn cells. Results were as follows: (i) diameter of nucleoli ranged from 2.0 microm to 6.0 microm; (ii) in each subject, no changes were seen in histogram patterns among ventral, intermediate, dorsal and overall sections; (iii) at < or =20 years of age, histograms displayed a single peak for the diameter of nucleoli at about 4.0-4.5 microm; (iv) at 21-60 years of age, histograms displayed two peaks, at about 3.5-4.0 microm and 5.0-5.5 microm; and (v) at 61-85 years of age, histograms displayed a single peak at about 5.0-5.5 microm.

Adolescent↗
PubMed2006

Multiple vertebral wedge osteotomy for adolescent idiopathic scoliosis.

19 idiopathic and 1 syringomyelia scoliosis patients (17 females and 3 males) underwent fusionless, multiple vertebral wedge osteotomy and with follow-up for an average of 8.9 years. The average age at surgery was 16.4 years. The average curve magnitude measured by Cobb was 64.0 degrees before surgery, 38.8 degrees after surgery, 43.7 degrees one year after surgery, 46.9 degrees two years after surgery and 48.2 degrees at the latest follow-up. The difference between the Cobb angle two years after surgery and latest follow-up was not significant. There were no major complications such as neurological problems.

Adolescent↗
PubMed2006

Correction of scoliosis using segmental pedicle screw instrumentation versus hybrid constructs with hooks and screws.

Eighteen consecutive patients with scoliosis surgically treated by posterior correction and fusion were recruited. The major coronal curve averaged 65.8 degrees (range 51 degrees -87 degrees ). Eight patients were treated by hybrid constructs and four of them had anterior release before posterior surgery. Ten patients were treated by posterior correction and fusion alone with pedicle screw instrumentation. Flexibility was assessed by radiographs using the active bending and the fulcrum bending techniques. Two correction indices were not statistically different between the two groups. However, there was a tendency towards better correction in the screw group: mean surgical correction was 62.6+/-11.8% in the hook group and 71.6+/-12.3% in the screw group (p=0.07). Comparable pre- and post-operative radiographic results may indicate the advantages of posterior-only segmental pedicle screw instrumentation over hybrid constructs.

Adolescent↗
PubMed2005

Distinct association of gene polymorphisms of estrogen receptor and vitamin D receptor with lumbar spondylosis in post-menopausal women.

Contribution of genetic backgrounds to the etiology of lumbar spondylosis has been suggested by epidemiological studies. This study was designed to determine the association of restriction fragment length polymorphisms (RFLPs) of estrogen receptor (ER), vitamin D receptor (VDR), parathyroid hormone (PTH) and interleukin-1beta (IL-1beta) genes with the radiological severity of lumbar spondylosis at the disk level from L1/2 to L5/S1 in Japanese post-menopausal women. ER and VDR RFLP haplotypes were associated with the severity of spondylosis in the upper levels (L1/2 and L2/3) more than in the lower levels. Association of ER genotype was more pronounced in the group younger than average than in the older group, while that of VDR genotype was more significant in the older group. Neither PTH nor IL1-beta RFLP was associated with the severity at any levels in either stratified group. We thus conclude that ER and VDR genes may contribute to lumbar spondylosis in a distinct manner: estrogen sensitivity influences the severity in the early phase after menopause while vitamin D plays an important role at older ages when the contribution of estrogen loss is weaker.

Female↗
PubMed2005

Results of posterior surgery with intraoperative radiotherapy for spinal metastases.

OBJECT: Spinal cord compression from spinal metastasis represents a substantial clinical problem. Complete resection of spinal metastases is difficult in many cases, and conventional surgical decompression of the spinal cord with or without instrumentation often results in unsatisfactory neurological recovery and local recurrence, even if combined with external radiotherapy. To increase rates of local control and improve neurological recovery in such cases, we introduced decompressive surgery combined with intraoperative radiotherapy (IORT) for the treatment of spinal metastasis in 1992. We report the results of neurological recovery and local control in cases that received surgery with IORT. METHODS: Between November 1992 and December 2001, 133 cases (117 patients) were treated using IORT at Tokyo Metropolitan Komagome Hospital. The 79 cases (74 patients) that received posterior spine surgery only for spinal paresis due to spinal metastasis were reviewed. RESULTS: Improvement of at least one level according to Frankel's classification was attained in 68 cases (86%). Of the 58 patients unable to walk preoperatively, 45 patients (78%) regained walking ability postoperatively. Rate of local recurrence was 2.5%. CONCLUSIONS: IORT, combined with posterior surgery and FERT, might be one of the effective methods for local control of spinal metastasis and neurological improvement, especially in cases with progressive and multi-level lesions.

Adult↗
PubMed2005

Can laminoplasty maintain the cervical alignment even when the C2 lamina is contained?

STUDY DESIGN: Retrospective case-controlled study of cervical laminoplasty. OBJECTIVE: To evaluate the alignment and clinical result by laminoplasty when the C2 lamina is contained or retained. SUMMARY OF BACKGROUND DATA: Resection of the C2 lamina was reported to progress to kyphosis after laminectomy. Laminoplasty was reported to inhibit kyphosis. But no study has ever shown if the alignment is retained when laminoplasty also included the C2 lamina. METHODS: Seventy-two patients with cervical spondylotic myelopathy undergoing laminoplasty were analyzed. Follow-up averaged 4.0 years. The outcome was assessed by the Cobb angle between C2 and C7, and the motor function scores of the upper and lower extremities for cervical myelopathy were made by the Japanese Orthopedic Association. Patients were stratified into three groups depending on the handling of the C2 lamina: fully split (S group; n = 17), C2 dome-like laminotomy (D group; n = 19), and intact (I group; n = 36). Change of the C2-C7 angle was compared by the analysis of variance and post hoc test. The association between the alignment and the motor scores was analyzed. RESULTS: Upper/lower score increased from 2.4/2.0 to 3.4/2.9, respectively. The C2-C7 angle decreased in S group: -8.3 degrees , D group: -5.2 degrees , and I group: -1.5 degrees . The cervical alignment deteriorated significantly in S group compared with the I group (P < 0.01). The C2-C7 angle change or postoperative C2-C7 angle had no significant correlation with the postoperative upper and lower m-JOA scores or score change. CONCLUSIONS: Subaxial laminoplasty maintained the alignment. But if laminoplasty included the C2 lamina, the alignment worsened.

Adult↗
PubMed2005

Klotho insufficiency causes decrease of ribosomal RNA gene transcription activity, cytoplasmic RNA and rough ER in the spinal anterior horn cells.

The klotho gene was identified in 1997 as the gene whose severe insufficiency (kl/kl) causes a syndrome resembling human aging, such as osteoporosis, arteriosclerosis, gonadal atrophy, emphysema, and short life span in a mouse strain. Regarding the gait disturbance reported in kl/kl mice, the present study examined the spinal cord of kl/kl mice, and revealed decreases in the number of large anterior horn cells (AHCs), the amount of cytoplasmic RNA, the number of ribosomes and rough endoplasmic reticulum (rER), and the activity of ribosomal (r) RNA gene transcription without significant loss of the total number of neurons in the ventral gray matter. Increased immunostaining of phosphorylated neurofilament in the AHCs and of glial fibrillary acidic protein in reactive astrocytes in the anterior horn of kl/kl mice were also observed. On the other hand, the posterior horn was quite well preserved. The results suggest that the kl/kl insufficiency causes atrophy and dysfunction of the spinal AHCs through decreased activity of rRNA gene transcription, which may reduce the amount of cytoplasmic RNA and the number of ribosomes and rER. These findings resemble those found in the spinal cord of patients with classic amyotrophic lateral sclerosis (ALS). The results show that klotho gene insufficiency causes dysfunction of the protein synthesizing system in the AHCs, and might indicate the klotho gene is involved in the pathological mechanism of classic ALS. The kl/kl is a new animal model of AHC degeneration, and may provide clues to understanding the etiology of classic ALS.

Animals↗
PubMed2005

Spinal stenosis in grade I degenerative lumbar spondylolisthesis: a comparative study of outcomes following laminoplasty and laminectomy with instrumented spinal fusion.

The management of grade I lumbar degenerative spondylolisthesis remains controversial. There have been few reports comparing any form of surgery with conservative treatment. As for surgical management, the need for arthrodesis with instrumentation has not been established. A series of 53 patients with single-level spinal stenosis at L4/5 due to grade I degenerative spondylolisthesis entered into a study to compare outcomes of two surgical methods of treatment with those of a control group treated conservatively: group 1, 19 patients treated by decompression laminectomy combined with posterolateral fusion and pedicle screw instrumentation; group 2, 18 patients treated by decompression of the spinal canal using a laminoplasty technique to preserve the integrity of the midline structure; group 3, 16 patients treated conservatively after being recommended that they have surgery. We compared the 2-year results among the three groups. Alleviation of symptoms was noted in groups 1 and 2, whereas the controls (group 3) showed no improvement. There was no significant difference in the degree of clinical improvement between groups 1 and 2. Spondylolisthesis was controlled in group 1, but it did not lead to better clinical results than those achieved in group 2. Our findings indicate that the technique for decompressing the spinal canal with preservation of the posterior elements of its roof can be useful for treating patients with grade I degenerative spondylolisthesis with symptoms of spinal stenosis.

Aged↗
PubMed2005

Revision cervical spine surgery using transarticular or pedicle screws under a computer-assisted image-guidance system.

BACKGROUND: The exact insertion of a cervical screw is technically demanding, especially when normal anatomic landmarks have been obscured and are difficult to identify, such as in revision surgery. The purpose of this study was to evaluate the efficacy of an image-guidance system to aid placement of transarticular and pedicular screws for revision cervical spine surgery. METHODS: Ten patients with recurrent myelopathy, including seven with cerebral palsy, two with a giant cell tumor, and one with rheumatoid arthritis, underwent computer-aided reconstruction surgery. The authors used a frameless stereotactic image-guidance system with simultaneous fluoroscopy. Postoperative computed tomography was used to determine the accuracy of the screw placement. RESULTS: There were no neurovascular complications and no correction loss. All patients showed solid bony union. All four C1/2 transarticular screws were exactly placed inside the pedicles. Of 47 pedicular screws, 11 showed a slight breach of the cortex. When a reference arc could not be attached to the relevant vertebra, the rate of cortical perforation of screws was high (5/10; 50%) compared with the rate when a reference arc was attached to the relevant vertebra (6/37; 16%). CONCLUSION: Although more advanced technology is hopeful, a computer-assisted image-guidance system with simultaneous fluoroscopy is useful for aiding revision surgery to achieve rigid fixation and ensure safety.

Bone Screws↗
PubMed2005

Bone resorption of the facet joint in rheumatoid arthritis as a predictor of lower cervical myelopathy.

The purpose of the present study was to identify the risk factors to predict instability of the subaxial cervical spine and cervical myelopathy based on plain radiographs. The study was performed on 99 patients with mutilating rheumatoid arthritis (RA). From plain lateral radiographs of the cervical spine over time, rheumatoid cervical spine lesions were investigated and evaluation was made on the possibility to develop cervical myelopathy. The incidence of subaxial cervical spine lesions in the patients with mutilating RA was as high as 98%. In particular, resorption of the superior facet suggests high risk to develop cervical myelopathy. The presence of spinous process erosion is also likely to reveal such a possibility. There was no statistically significant difference in the anteroposterior diameter of cervical spinal canal between the cases with cervical myelopathy and those without it. Resorption of the superior facet is the most important factor for the development of cervical myelopathy. In the cases with rheumatoid cervical spine lesions, it is necessary to take special notice of the superior facet.

Journal Article↗
PubMed2005

Image-guided surgery for thoracic ossification of the posterior longitudinal ligament. Technical note.

The authors describe an anterior decompression procedure for thoracic ossification of the posterior longitudinal ligament (PLL) in which they used an image guidance system in three cases. To make registration possible in anterior thoracic surgery, they devised a surgical reference frame that could be connected to a rod and attached to an external fixation device, which was then attached to the thoracic VB. The mean fiducial error at the registration was acceptable (range 0.5-0.8 mm). They were able to confirm the success of decompression on postoperative computerized tomography scans. In the removal of an ossified thoracic PLL, an image guidance system has been shown to be a useful tool.

Decompression, Surgical↗
PubMed2004

Postoperative expansion of intramedullary high-intensity areas on T2-weighted magnetic resonance imaging after cervical laminoplasty.

STUDY DESIGN: A cohort study. OBJECTIVE: To determine the frequency of swelling of the spinal cord with an intramedullary lesion occurring after laminoplasty for nontraumatic cervical myelopathy and the possible mechanism of postoperative motor paresis of the upper extremity. SUMMARY OF BACKGROUND DATA: Postoperative enlargement of the spinal cord with an intramedullary lesion after decompression surgery for cervical stenotic myelopathy has been reported. But the frequency of the incidence remains unknown. Postoperative motor paresis occurring mainly in the C5 and C6 segments is known but various theories on its etiology exist, including the root involvement hypothesis and the spinal cord impairment hypothesis. Thus, the etiology is controversial. METHODS: One hundred fourteen patients with cervical stenotic myelopathy were included in this study. All of them underwent preoperative magnetic resonance imaging and postoperative magnetic resonance imaging 3 weeks after surgery. We watched for the occurrence of postoperative neurologic deterioration including paralysis of the upper extremities. We also observed the presence or absence of postoperative abnormal expansion of T2 high-signal intensity areas on magnetic resonance imaging in the spinal cord. RESULTS: Seven patients (6.1%) showed postoperative abnormal expansion of the T2 high-signal intensity area; 3 of the 7 were asymptomatic. A total of 9 patients (7.9%) experienced unilateral upper motor paresis after surgery. In 4 of the 9 cases, paresis of the unilateral deltoid, biceps and brachialis muscles (proximal paresis) occurred between 4 and 6 days after surgery. None of the 4 showed postoperative abnormal expansion of the T2 high-signal intensity area. In 3 other of the 9 patients, distal paresis occurred just after surgical intervention. Two of the 3 showed postoperative abnormal expansion of the T2 high-signal intensity area and 1 showed slight expansion of the area. In the other 2 cases, diffuse paresis occurred, and their postoperative magnetic resonance imaging showed abnormal expansion of the T2 high-signal intensity area. CONCLUSIONS: Spinal cord enlargement with abnormal expansion of the T2 high-signal intensity area, although not common, is an unpreventable complication after laminoplasty. This was strongly related with distal and diffuse type of postoperative paresis of the upper extremity without deterioration of lower motor function, but was little associated with a proximal type of paresis, so-called C5 and C6 palsies.

Aged↗