Mei-Hsiu Chen

Cervical subdural empyema following acupuncture.

A review of the literature reveals only a few cases of spinal subdural empyema. Etiologies of spinal subdural empyema include hematogenous spread from skin lesions, systemic sepsis, direct spread from spinal osteomyelitis and complications of discography. However, in this report, we describe a patient who developed spinal subdural empyema following several cervical acupuncture sessions. Operative treatment with adequate laminectomy, removal of abscess, and copious irrigation resulted in good recovery. Microbiologic culture study of pus obtained at surgery was positive for Staphylococcus aureus. The need for sterilization procedures for acupuncture is emphasized and a brief review of the relevant literature is presented.

A lumbar clear cell meningioma with foraminal extension in a renal transplant recipient

Spinal meningiomas are characteristically dural based. We report a lumbar clear cell meningioma extending into the intervertebral foramen without dural attachment which mimics a neurilemmoma. This is a rare finding, with no other reported cases in the literature. The importance of recognizing clear cell meningioma relates specifically to its inordinately aggressive clinical course. Compared to with of spinal clear cell meningiomas reported to date, our case showing the extension into the intervertebral foramen and mimicking a neurilemmoma is rather unique. Clear cell meningioma may be confused with other clear cell tumors, especially with the similar-looking metastatic renal cell carcinoma, which should be carefully ruled out in our case - an immunosuppressed renal transplant recipient.

Catheter migration after implantation of an intrathecal baclofen infusion pump for severe spasticity: a case report.

We report a case of intrathecal baclofen infusion pump implantation complicated by migration of the catheter tip. A 55‐year‐old man required an intrathecal baclofen infusion for severe spasticity 4 years after a cervical spinal cord injury with incomplete tetraparesis. Twelve months after initial implantation of the device, the patient began to experience a recurrence of trunk tightness and spasticity. Subsequent X‐ray and computed tomography evaluations of the catheter system revealed pooling of contrast medium outside of the intrathecal distribution in the lumbar subcutaneous region of the back and therefore migration of the pump catheter tip. At surgical revision, emphasis was placed on minimizing the length of catheter outside of the spine and securing the catheter in the supraspinous fascia with a right‐angled anchor. The distance between the anchors and the entry point of the catheter into the supraspinous fascia was also reduced to prevent slipping when the patient bends forward. After surgery, the patients spasticity improved and, 1 year later, he has experienced no further complications during follow‐up, requiring an average baclofen dose of 150 mg/day. Here, we describe several surgical methods intended to secure the intrathecal catheter and prevent catheter migration. Other complications related to catheter failure are also highlighted.

Low-intensity pulsed ultrasound stimulates matrix metabolism of human annulus fibrosus cells mediated by transforming growth factor β1 and extracellular signal-regulated kinase pathway

Abstract Purpose: There are limited strategies to restore the damaged annulus fibrosus (AF) of the intervertebral disc. Low-intensity pulsed ultrasound (LIPUS) has positive effects on the proliferation of several types of cells and the repair of damage tissue in vivo. However, scientific evidence of therapeutic effects of LIPUS on AF cells remains limited. The purpose of this study is to evaluate the feasibility of applying LIPUS to the repair of the AF. Materials and methods: We used an in vitro model of human AF cells subjected to LIPUS stimulation to examine its effects on cell proliferation and matrix metabolism. Cell viability, synthesis of collagen and glycosaminoglycan (GAG), expression of matrix metalloproteinases (MMPs) and transforming growth factor β1 and pathways involving mitogen-activated protein kinases (MAPKs) were investigated. Results: LIPUS significantly enhanced proliferation of AF cells after 5 days of treatment. LIPUS with an intensity of 0.5 W/cm2 increased the collagen and GAG synthesis and decreased the expressions of MMP-1 and -3 of human AF cells. Real-time polymerase chain reactions and western blotting analysis revealed that LIPUS could increase transforming growth factor β1 (TGF-β1) and activate extracellular signal-regulated kinase (ERK) pathway. In addition, TGF-β receptor kinase inhibitor could suppress the ultrasound-induced alterations in cell viability and matrix metabolism. Conclusions: The findings suggested that LIPUS could be useful as a physical stimulation of cell metabolism for the repair of the AF.

Ibuprofen-conjugated hyaluronate/polygalacturonic acid hydrogel for the prevention of epidural fibrosis:

The formation of fibrous tissue is part of the natural healing response following a laminectomy. Severe scar tissue adhesion, known as epidural fibrosis, is a common cause of failed back surgery syndrome. In this study, by combining the advantages of drug treatment with a physical barrier, an ibuprofen-conjugated crosslinkable polygalacturonic acid and hyaluronic acid hydrogel was developed for epidural fibrosis prevention. Conjugation was confirmed and measured by 1D 1H NMR spectroscopy. In vitro analysis showed that the ibuprofen-conjugated polygalacturonic acid–hyaluronic acid hydrogel showed low cytotoxicity. In addition, the conjugated ibuprofen decreased prostaglandin E2 production of the lipopolysaccharide-induced RAW264.7 cells. Histological data in in vivo studies indicated that the scar tissue adhesion of laminectomized male adult rats was reduced by the application of our ibuprofen-conjugated polygalacturonic acid-hyaluronic acid hydrogel. Its use also reduced the population of giant cells and collagen deposition of scar tissue without inducing extensive cell recruitment. The results of this study therefore suggest that the local delivery of ibuprofen via a polygalacturonic acid-hyaluronic acid-based hydrogel reduces the possibility of epidural fibrosis.

An injectable extracellular matrix for the reconstruction of epidural fat and the prevention of epidural fibrosis.

Extensive epidural fibrosis is a common complication following spinal surgery and can cause pain and limited mobility. In the present study, a novel biomimetic approach was developed to prevent postsurgical adhesion of the dura. We aimed to reconstruct epidural fat, which prevents scar-tissue adhesion, through the development of an injectable decellularized adipose matrix (DAM)-containing hyaluronic acid (HA) hydrogel loaded with adipose stromal cells (ASCs). Injectable DAM was prepared from porcine adipose tissue by four freeze-thaw cycles with subsequent pepsin digestion. Residual analyses confirmed the efficacy of detergent-free decellularization, while most sulfated glycosaminoglycans and collagen were preserved. The Transwell migration assay demonstrated the anti-infiltrative property of the DAM-containing HA hydrogel. After 14 d of 3D culture, the DAM-containing HA hydrogel showed inductive potential in the adipogenic differentiation of ASCs. For an in vivo study, the ASC-loaded DAM-containing HA hydrogel (DAM/ASC-incorporated HA hydrogel) was injected into adult laminectomized male rats, and the results were assessed by microscopic histological examination. The in vivo data indicated that HA hydrogel, DAM, and ASCs were all required for the ability of the engineered fat tissue to block the invasion of the fibrous tissue. Our results suggested that this injectable DAM/ASC-incorporated HA hydrogel has potential applications in minimally invasive surgery for soft-tissue reconstruction and epidural fibrosis prevention.

MRI features of an infected cephalhaematoma in a neonate

Bacterial infection of a cephalhaematoma is rare and has been associated with needle aspiration of the haematoma, placement of scalp electrodes and systemic sepsis. Clinical diagnosis of infected cephalhaematoma is difficult without obvious evidence of local infection. The role of imaging in differentiating infected from non-infected cephalhaematoma has not been clearly established. Needle aspiration is considered mandatory for suspected cases. In this report, we present the magnetic resonance imaging (MRI) findings of a 23-day-old neonate with an infected cephalhaematoma. Cephalhaematoma is a subperiosteal accumulation of blood, thus the diagnosis of infected cephalhaematoma was made as the MRI showed an accumulation of blood under thick, contrast-enhancing periosteum in the presented case. Without a diagnostic puncture, the decision for surgical intervention was made before complicating osteomyelitis developed. Early intervention with simple incision and drainage resulted in prompt improvement.

Gelatin-tricalcium phosphate membrane modified with ngf and cultured schwann cells for peripheral nerve repair : A tissue engineering approach

This study attempted to enhance the efficacy of peripheral nerve regeneration using our previously developed gelatin-tricalcium phosphate (GTG) conduits by incorporating them with nerve growth factors and cultured Schwann cells. The nerve growth factors were covalently immobilized onto the GTG conduits (GEN) using carbodiimide. Schwann cells were harvested from neonatal Lewis rats, cultured for seven days and injected into the GEN conduits. The experiment was performed in three groups: GTG conduits, GEN conduits and GEN conduits with Schwann cells injected (GEN+Sc). The effects of different conduits (GTG, GEN and GEN with Schwann cells) on the peripheral nerve regeneration were evaluated in rat sciatic nerve repair model. 24 weeks after implantation of conduits, degradation of the conduits in all groups was illustrated by the fragmentation of the conduits. All conduits were well tolerated by the host tissue. Under microscopic evaluations, regenerated nerve tissue with myelinated and unmyelinated axons presented in all groups. Histomorphometrically, the total nerve area of GEN+Sc group was significantly higher than GTG group. Conversely, the autotomy score evaluated 12 weeks after nerve repair showed better results for GTG group. Besides, GEN+Sc group had the highest average recovery index of compound muscle action potential, but the difference among each group did not reach statistical significance. Although the electrophysiological recovery of nerve was not significantly improved with GEN+Sc conduit, nerve repair using tissue engineered conduits still provided better histological results. However, it should be noticed that autotomy may be the price paid for enhanced peripheral nerve.