Biomedical subjects

Chang-Young Lee

Publications and source records attributed to Chang-Young Lee.

8 recordsLinked to original sources

PubMed2006

Traumatic pseudoaneurysm of the pharyngeal artery: An unusual cause of hematemesis and hematochezia after craniofacial trauma.

BACKGROUND: Traumatic aneurysms of the internal maxillary artery are extremely rare. We report a case of traumatic pseudoaneurysm of the pharyngeal artery, a branch of the internal maxillary artery, presenting with hematemesis and hematochezia. CASE DESCRIPTION: An 18-year-old man presented with deep drowsy consciousness after a motor vehicle accident, in which he had a severe craniofacial injury. Three days later, he had hematemesis and hematochezia with a marked decrease in circulating hemoglobin level. External carotid arteriography performed to rule out vascular injury revealed active leakage from a false aneurysm of the pharyngeal artery. The lesion was successfully obliterated by superselective endovascular embolization. CONCLUSIONS: In patients with craniofacial injury associated with multiple traumas, traumatic pseudoaneurysm of the pharyngeal artery should be suspected as one of the possible causes of hematemesis and hematochezia. Selective endovascular embolization with cerebral angiography is an effective modality for the treatment and diagnosis of this lesion.

Accidents, Traffic↗

PubMed2006

Effect of smear layer and chlorhexidine treatment on the adhesion of Enterococcus faecalis to bovine dentin.

The aim of this in vitro study was to determine the effects of a smear layer and chlorhexidine (CHX) treatment on the adhesion of Enterococcus faecalis to bovine dentin. Forty dentin blocks from bovine incisors were prepared and randomly divided into four groups of 10 each. The blocks in group 1 were placed in sterile saline for 5 minutes, while those in group 2 were treated with 17% EDTA for 5 minutes. The blocks in group 3 were placed in 2% CHX for 7 days. The blocks in group 4 were treated with 17% EDTA for 5 minutes, and then placed in 2% CHX for 7 days. All the blocks were immersed in a suspension of E. faecalis for 3 hours. The bacteria adhering to the dentin surface were counted by examination using a scanning electron microscope. The most significant amount of bacteria was retained on the samples from group 1 (p < 0.05) and the smallest amount of bacteria adhered to the samples from group 4. These results suggest that a smear layer enhances the adherence of E. faecalis to the dentin, and CHX is effective in reducing the adherence of microorganisms.

Analysis of Variance↗

PubMed2006

Primary stent therapy for symptomatic intracranial atherosclerotic stenosis: 1-year follow-up angiographic and midterm clinical outcomes.

OBJECT: The aim of this study was to report 1-year angiographic follow-up results and midterm clinical outcomes in patients with symptomatic intracranial atherosclerotic lesions treated with stent placement. METHODS: Ten patients with ischemic symptoms referable to stenotic intracranial atherosclerotic arteries, with greater than 60% stenosis, underwent elective surgery in which a primary stent was placed. All patients underwent pretreatment (> or =1 week) combination oral antiplatelet (clopidogrel and aspirin) therapy and long-term (6-month) combination oral antiplatelet (clopidogrel and aspirin) therapy after stents were placed. The procedure involved selecting stents of the same size as the diameter of the target vessel and slowly inflating the balloon to its nominal pressure. One-year angiography and midterm clinical follow-up data were obtained. The stents were successfully placed in all patients without any perioperative complication. The mean preoperative stenosis rate of 81% decreased to 4% after the stent was placed. Nine patients who underwent follow-up angiography (one patient refused) at a mean of 12.3 months (range 10-19 months) had no changes in luminal diameter compared with the immediate postoperative luminal diameter. Luminal narrowing increased, from 15 to 38%, in one case in which there was comparatively greater residual stenosis (15%). No patient suffered new ischemic symptoms during a mean clinical follow-up period of 21 months (range 12-36 months). CONCLUSIONS: Elective stent surgery can provide good angiographic and clinical midterm outcomes in patients with symptomatic intracranial atherosclerotic stenosis, and the procedure is associated with a high degree of technical success. Reassessment of these promising results is needed in a larger population and in a randomized prospective comparison study.

Adult↗

PubMed2005

Three-dimensional visualization of a mandibular first molar with three distal roots using computer-aided rapid prototyping.

Nonsurgical endodontic therapy of a right mandibular first molar with 3 distal roots was successfully performed with the aid of magnification. 3D data (DICOM format) of the tooth were obtained from a CT HighSpeed Advantage and a Denta Scan program produced by GE Medical Systems. The CT protocol used for this procedure involved a slit thickness of 1 mm. The 3D digital data obtained were fed into a visualization program (V-works; Cybermed Co) and then exported to the rapid prototyping machine for fabrication of the actual-sized tooth model. The material for the model-making process was starch. The 3D digital visualization and the computer-aided rapid prototyping (CARP) model clearly showed 3 separate distal roots (distobuccal, distolingual, and middle distal). The CARP technique seems to be a useful imaging technology to document unusual root anatomy in clinical dentistry.

Adult↗

PubMed2005

Three-dimensional computed tomography-guided multitract aspiration of extensive ganglionic hemorrhage: technical note.

BACKGROUND: We describe a methodology for effectively improving the lysis and drainage of intracerebral hematomas during stereotactic surgery. METHODS: Stereotactic aspiration using a multitrack technique was performed in 20 patients with ganglionic hemorrhages perforating into the subcortex. Using 3-dimensional computed tomography (3D-CT) guidance, the trajectories and targets of hematoma drainage were selected to extract most portions of the irregular and expansive intracerebral hematomas. Volumes ranged from 36 to 60 mL (mean, 45 mL). Four to 5 drains were inserted into the parenchymal and ventricular clots. Aspiration and injections of urokinase (5000 IU) were repeated every 2 to 3 hours until the hematoma was almost completely removed. RESULTS: The intended catheters for hematoma aspiration were placed precisely along the predetermined tracks with the aid of 3D-CT visualization. The deep and subcortical hematomas were totally removed within a mean of 10 hours postoperatively. Multiple catheter placements itself caused no complications. Sixteen patients (80%) recovered with a favorable neurological outcome. CONCLUSIONS: The 3D-CT-based multitrack technique is a rapid and effective method for the stereotactic removal of extensive ganglionic hemorrhages. It has the advantage of giving better neurological recovery than conventional stereotactic or microscopic surgery for selected patients.

Adult↗

PubMed2005

The sustaining effect of three polymers on the release of chlorhexidine from a controlled release drug device for root canal disinfection.

OBJECTIVES: The aim of this in vitro study was to evaluate the suitability of using chitosan, poly (lactide-co-glycolide) (PLGA), and polymethyl methacrylate (PMMA) to control the release of chlorhexidine digluconate (CHX) from a prototype of controlled release drug device for root canal disinfection. STUDY DESIGN: Four different prototypes with different formulations were prepared. Group A (n = 12): the device (absorbent paper point) was loaded with CHX as control. Group B (n = 12): same as group A, but the device was coated with chitosan (Texan MedTech). In Groups C and D, the device was treated in the same way as group A and then coated 3 times with 5% PMMA (Group C, n = 12, Aldrich), or coated 3 times with 3% PLGA (Group D, n = 12, Sigma). The devices were randomly allocated to experimental groups of 12 each. All the prototypes of controlled release drug device were soaked in 3 mL distilled water. The concentrations of CHX were determined using a UV spectrophotometer. The surface characteristics of each prototype were observed using a scanning electron microscope. RESULTS: The result showed that release rate of CHX was the greatest in the noncoated group, followed by the chitosan-coated group, the PLGA-coated group, and the PMMA-coated group (P < 0.05). Pores were observed on the surface of the prototypes that were coated with PLGA and PMMA. When the pore size was smaller, the release rate was lower. CONCLUSION: These data indicate that polymer coating can control the release rate of CHX from the prototypes of controlled release drug device.

Analysis of Variance↗

PubMed2004

Traumatic aneurysm of the supraclinoid internal carotid artery and an associated carotid-cavernous fistula: vascular reconstruction performed using intravascular implantation of stents and coils. Case report.

This report documents the treatment of a traumatic aneurysm of the supraclinoid internal carotid artery (ICA) that was associated with a carotid-cavernous fistula (CCF), which appeared following closed head trauma. This life-threatening lesion, which is very rare, required aggressive management achieved using intravascular stents and coils. A 19-year-old man presented with severe traumatic intracerebral and subarachnoid hematoma after he had suffered a severe closed head injury in a motor vehicle accident. Cerebral angiography performed 11 days after the injury demonstrated a traumatic aneurysm and severe narrowing of the right supraclinoid ICA, which was consistent with a dissection-induced stenosis associated with a direct CCF. Both lesions were successfully obliterated with preservation of the parent artery by using stents in conjunction with coils. Follow-up angiography obtained 7 months postoperatively revealed persistent obliteration of the aneurysm and CCF as well as patency of the parent artery. The patient remained asymptomatic during the clinical follow-up period of 14 months. Endovascular treatment involving the use of a stent combined with coils appears to be a feasible, minimally invasive option for treatment of this hard-to-treat lesion.

Adult↗

PubMed2002

Merits of intralesional fibrin glue injection in surgery for cavernous sinus cavernous hemangiomas. Technical note.

In planning surgical treatment for extraaxial cavernous hemangiomas, care should be taken to control severe tumor bleeding. The authors present a case of a large cavernous hemangioma of the cavernous sinus, which was completely removed with the aid of multiple intratumoral injections of fibrin glue. This novel method is very effective for preventing excessive blood loss during surgery for this type of lesion.

Adult↗