PURPOSE: Porous hydroxyapatite is resorbable and osteoconductive, so it is slowly replaced by ingrowing new bone. Optimal pore geometry for osteoconduction, however, has not been determined yet. The objective of this investigation was to assess both the histological response and the reinforcing effects of bone ingrowth within the porous hydroxyapatite implants depending on pore size. MATERIALS AND METHODS: Four kinds of cylindrical types (50, 100, 300, 500 micrometer) of porous hydrox-yapatite were prepared. Fifty-six white rabbits were divided into 4 groups and porous hydroxyapatite block was inserted through the medial cortical window of a proximal tibia. Histomorphological changes were examined using light microscopy and scanning electron microscopy. Biomechanical compression test was performed using a material test machine. RESULTS: Hydroxyapatite implants appeared to have no early adverse effects, such as inflammation and foreign body reaction. Osteoconduction through the pores was found in all four implants and new bone was found on the surface of pores with no histologically demonstrable intervening nonosseous tissue. At four weeks after implantation, new bone was arranged in a concentric pattern around the vessel, similar to osteon. New bone formation through pores was most evident at 300 micrometer-sized type. At 8 weeks, active osteoconduction was also found at 50 micrometer-sized type. Evidence of bone marrow formation within porous hydroxyapatite was found. In a biomechanical study, ultimate compression strength significantly increased in the 300 micrometer-sized type, after 8 weeks implantation compared to preimplantation. CONCLUSIONS: Porous hydroxyapatite implanted into rabbit tibia showed biological fixation and osteointegration. A pore size of 300 micrometer was most effective for bone ingrowth. Osteoconduction also took place in 50 micrometer-sized cylindrical pores.
Bone Marrow ; Bone Regeneration* ; Durapatite* ; Foreign-Body Reaction ; Haversian System ; Inflammation ; Microscopy ; Microscopy, Electron, Scanning ; Osteogenesis ; Rabbits ; Tibia

Because of the two merits of nonoperative management of blunt abdominal trauma, 1) avoidance of operative morbidity and 2) better treatment of associated injuries, the use of nonoperative management has been extended, but the indications for such treatment have not been sufficiently found. One hundred two(102) cases admitted due to hemoperitoneum, 44 involving surgery and 58 conservative managment, were analyzed for age, sex, cause of injury, injured organ, injury grade, transfusion amount, and shock on admission. The major causes of injury in the nonoperative and the operative groups are as follows : 23 cases of auto-pedestrian accidents and 15 cases of in-car accidents in the nonoperative group and 19 cases of auto-pedestrian accidents in the operative group. In terms of the injured organ, liver trauma was the most frequent, and spleen trauma was next. The difference in the transfusion amount between the two groups was statistically significant; 8.1 units in the nonoperative group and 13 units in the operative group. In conclusion, 1) nonoperative management can be considered as a first choice in children with blunt abdominal trauma and stable vital signs; 2) patients with hemodynamically stable liver injury with AAST OIS grade 4 and isolated splenic injury AAST OIS grade 4 are candidates for nonoperative management; and 3) nonoperative management through emergency care without transfusion can be considered in cases with stable vital signs.
Child ; Emergency Medical Services ; Hemoperitoneum* ; Humans ; Liver ; Shock ; Spleen ; Vital Signs

PURPOSE: To describe the characteristics of CT findings in nasal lymphoma. MATERIALS AND METHODS: We retrospectively reviewed CT findings and pathologic findings of eight patients (six males and two females) aged between 24 and 68 years with pathologically-proven nasal lymphoma. We analyzed mass location, laterality, size, margin, mass effect, adjacent bony change and contrast enhancement pattern. RESULTS: All eight cases werenon-Hodgkin's lymphoma, intermediate grade, diffuse large cell type. Seven cases were B-cell type and one was T-cell. In all cases, tumors were located in the medial wall of the inferior turbinate. In four cases, they were also found in the anterior ethmoidal sinus, and in one case, in the nasal septum. The mean size of the main mass was 3.3 cm. In seven cases, tumors were unilateral (one on the right; six on the left), and in the remaining case, bilateral. In six cases tumor margin was smooth and in two cases focal nodularity was seen. In two cases there was no bony change, and in four, there was mucosal thickening along the nasal septum; in one of these four, minimal bony erosion was also found. In the other two cases, bony destruction was seen, and tumors were very large (7 cm in diameter) or bilterally located. In three cases, the nasal septum was displaced by the mass. In all cases with bony change, the nasal septum was involved. All tumors were homogeneously well enhanced after IV contrast administration. CONCLUSION: The main CT findings of nasal non-Hodgkin's lymphoma were smooth margin, unilateral location (mainly in the medial wall of the inferior turbinate and growing to the medial side without bony destruction) mucosal thickening along the nasal septum and clear homogeneous enhancement after IV contrast administration. These characteristics will help diagnosis, help determine the appropriate region for radiation and other appropriate therapy, and facilitate prognosis in patients with nasal non-Hodgkin's lymphoma.
B-Lymphocytes ; Diagnosis ; Humans ; Lymphoma ; Lymphoma, Non-Hodgkin* ; Male ; Nasal Septum ; Prognosis ; Retrospective Studies ; T-Lymphocytes ; Turbinates

Cancer-related stroke is occasionally observed in elderly patients, with varying risks depending on the cancer type. Traditionally, lung and pancreatic cancers exhibit the highest stroke risk by increased venous thromboembolism associated with cancer-induced hypercoagulability. However, we present a novel case of immediate recurrent thrombosis in separate large vessels, including the basilar and internal carotid arteries, during endovascular thrombectomy. Retrieved thrombus was identified as cancer cells in a patient with sarcomatoid carcinoma and multifocal metastases to the spine and iliacus muscle.

Cancer-related stroke is occasionally observed in elderly patients, with varying risks depending on the cancer type. Traditionally, lung and pancreatic cancers exhibit the highest stroke risk by increased venous thromboembolism associated with cancer-induced hypercoagulability. However, we present a novel case of immediate recurrent thrombosis in separate large vessels, including the basilar and internal carotid arteries, during endovascular thrombectomy. Retrieved thrombus was identified as cancer cells in a patient with sarcomatoid carcinoma and multifocal metastases to the spine and iliacus muscle.

Cancer-related stroke is occasionally observed in elderly patients, with varying risks depending on the cancer type. Traditionally, lung and pancreatic cancers exhibit the highest stroke risk by increased venous thromboembolism associated with cancer-induced hypercoagulability. However, we present a novel case of immediate recurrent thrombosis in separate large vessels, including the basilar and internal carotid arteries, during endovascular thrombectomy. Retrieved thrombus was identified as cancer cells in a patient with sarcomatoid carcinoma and multifocal metastases to the spine and iliacus muscle.

BACKGROUND: Hypotension is one of the most common complications from the spinal anesthesia frequently used for surgery on the lower abdomen or extremities. It might be important in prognostic improvements to maintain cardiovascular homeostasis in elderly or patients with cardiovascular diseases. This study evaluated the effect of the patients' position on the preservation of cardiovascular stability when elderly patients suffering from hypertension undergo surgery for an axillo-femoral arterial bypass. METHODS: 24 patients with hypertension undergoing an elective axillo-femoral bypass surgery were examined. The patients were randomly allocated into two groups (Lateral 20 min group: patients with lateral position for 20 min after spinal anesthesia; Supine group: patients with the supine position immediately after spinal anesthesia). The observers recorded the hemodynamic variables, as well as the loss of sensation on both sides. RESULTS: Considering the changes in the arterial blood pressure and heart rate from the baseline values, patients in the supine group showed a greater decrease in arterial blood pressure and heart rate (P < 0.05). In the lateral 20 min group, there was a lower block level of cold sensation that reflected the sympathetic blockade at the non-operated site (P < 0.05). CONCLUSIONS: The lateral decubitus position for 20 min after spinal anesthesia can contribute to the maintenance of cardiovascular stability during unilateral axillo-femoral bypass surgery in elderly patients with hypertension.
Abdomen ; Aged ; Anesthesia, Spinal* ; Arterial Pressure ; Blood Pressure* ; Cardiovascular Diseases ; Extremities ; Heart Rate* ; Heart* ; Hemodynamics ; Homeostasis ; Humans ; Hypertension ; Hypotension ; Sensation ; Supine Position

BACKGROUND: Melatonin has been shown to attenuate the reflex sympathetic increases that arise in response to orthostatic challenges. We tested the hypothesis that the attenuated sympathetic increase induced by melatonin premedication may weaken the arterial blood pressure (ABP) preserving the capability during acute hypotension, thereby altering dynamic cerebral autoregulation and causing a further decrease in cerebral blood flow (CBF). METHODS: Acute hypotension was induced in 12 healthy subjects by releasing bilateral thigh cuffs before and after an oral dose of melatonin (0.2 mg/kg). Heart rate (HR), arterial blood pressure (ABP), Modelflow estimate of cardiac output (CO), total peripheral resistance (TPR) and cerebral blood flow velocity (CBFV) by transcranial Doppler were measured. RESULTS: Steady state HR, the mean arterial pressure and CBFV were not altered 60 minutes after melatonin ingestion. Reduced systolic arterial pressure (DeltaSAP), changes in HR (DeltaHR), CO (DeltaCO), and TPR (DeltaTPR), DeltaHR/DeltaSAP and percentage restoration of SAP were not affected after a temporal decrease in ABP induced by thigh cuff release. In the cerebral circulation, melatonin did not affect changes in CBFV, cerebrovascular resistance index, the rate of regulation and percentage restoration of CBFV following a sudden decrease in ABP. CONCLUSIONS: Contrary to our hypothesis, melatonin did not affect the rapid vasodilatory and recovery responses of cardiovascular and dynamic cerebral autoregulation. These results suggest that melatonin premedication may not impair ABP and CBF preserving capability induced by sudden postural changes or hemorrhage.
Arterial Pressure ; Blood Flow Velocity ; Blood Pressure ; Cardiac Output ; Cerebrovascular Circulation ; Eating ; Heart Rate ; Hemorrhage ; Homeostasis ; Humans ; Hypotension ; Male ; Melatonin ; Premedication ; Reflex ; Thigh ; Vascular Resistance

Transurethral resection of the prostate (TURP) is a common procedure for managing benign prostatic hyperplasia (BPH), and this procedure is associated with low complication rates. Bladder perforation is an unusual complication of TURP, and it may create an air leak into the retroperitoneal space. Here we describe a case of pneumomediastinum, pneumoretroperitoneum and subcutaneous emphysema that were all due to a bladder perforation that occurred during performing TURP in a 74-year-old male patient with BPH.
Aged ; Humans ; Male ; Mediastinal Emphysema ; Prostate ; Prostatic Hyperplasia ; Retroperitoneal Space ; Retropneumoperitoneum ; Subcutaneous Emphysema ; Transurethral Resection of Prostate ; Urinary Bladder

OBJECTIVES: The purpose of this retrospective study is to find the differentiating characteristics of cystic and cystic-appearing lesions that involve the impacted mandibular third molar by analyzing panoramic radiographs and computed tomography images, and to aid the preoperative diagnosis. MATERIALS AND METHODS: Eighty-one patients who had a mandibular cystic or cystic-appearing lesion that involved impacted mandibular third molar and underwent cyst enucleation were included in the study. The preoperative panoramic radiograph and computed tomography findings were analyzed in accordance to the histopathologic type. RESULTS: Most of the cystic lesions containing the mandibular third molar were diagnosed as a dentigerous cyst (77.8%). The occurrence of mesio-distal displacement of the third molar was more frequent in the odontogenic keratocyst (71.4%) and in the ameloblastoma (85.7%) than in the dentigerous cyst (19.1%). Downward displacement was primarily observed in each group. Odontogenic keratocyst and ameloblastoma showed more aggressive growth pattern with higher rate of bony discontinuity and cortical bone expansion than in dentigerous cyst. CONCLUSION: When evaluating mandibular cystic lesions involving the impacted mandibular third molar, dentigerous cyst should first be suspected. However, when the third molar displacement and cortical bone absorption are observed, then odontogenic keratocyst or ameloblastoma should be considered.
Absorption ; Ameloblastoma ; Dentigerous Cyst ; Diagnosis ; Humans ; Mandible ; Molar, Third* ; Odontogenic Cysts ; Retrospective Studies ; Tooth*