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Biomedical subjects

K J Cho

Publications and source records attributed to K J Cho.

At least 181 records · Page 10Linked to original sources
PubMedDate not supplied

Carbon dioxide gas as a venous contrast agent to guide upper-arm insertion of central venous catheters.

PURPOSE: Evaluate in a prospective randomized study carbon dioxide (CO2) gas compared to iodinated contrast agent for image-guided placement of peripherally inserted central venous catheters (PICCs). METHODS: The upper-arm approach to the central vein was used for placement of PICCs in 74 patients requiring intermediate or long-term central venous access. Fluoroscopy was used to obtain venous access during peripheral injection of CO2 (n = 41) or low osmolar contrast material (Omnipaque 240 mgI/ml) (n = 33). RESULTS: Placement of PICCs was accomplished in 88% of the CO2 group and in 100% of the contrast group, with a mean venipuncture of two in both groups. Venous access was unsuccessful in five patients with CO2 due to a small vein, venous spasm, or technical failure. The mean and range of procedure times were 22.8 min (13-64 min) with CO2 and 23.2 min (12-60 min) with contrast material. The average and range of CO2 and nonionic contrast volumes injected during the procedure were 35.4 ml (5-300 ml) and 27.8 ml (8-120 ml), respectively. Vital signs and oxygen saturation did not change significantly during or after injection of CO2. There was no incidence of adverse reaction following CO2 injection. CONCLUSION: CO2 gas is a useful contrast agent to guide upper-arm insertion of PICCs and may be a safe alternative in patients with renal insufficiency and/or allergy to iodinated contrast material.

Adolescent↗
PubMedDate not supplied

Percutaneous transhepatic embolization as treatment for bleeding ileostomy varices.

We report two patients with bleeding stomal varices following total colectomy and ileostomy. The varices were demonstrated by superior mesenteric angiography and percutaneous transhepatic mesenteric venography; dilated ileal veins drained via the stomal varices into abdominal wall veins. Bleeding from the stomal varices was treated by transhepatic embolization. The first patient required three transhepatic embolizations after recurrent bleeding due to recanalization of the embolized ileal vein and the development of collaterals from the adjacent ileal veins over a one-year period. The second patient died of respiratory failure 1 week after embolization. Neither patient developed mesenteric or stomal ischemia.

Aged↗
PubMedDate not supplied

Embolic control of lumbar artery hemorrhage complicating percutaneous renal biopsy with a 3-F coaxial catheter system: case report.

A case is presented in which massive retroperitoneal hemorrhage from the left first lumbar artery complicating a percutaneous renal biopsy was successfully controlled by superselective embolization with microcoils. An anterior radiculomedullary artery (artery of Adamkiewicz) originated from the lumbar artery. To minimize the risk of ischemic damage to the spinal cord from embolization, the extravasating branch of the lumbar artery had to be superselectively catheterized using a 3-F coaxial catheter system. Computed tomography (CT) scan localized the hematoma within the left posterior pararenal space in the retroperitoneal space.

Arteries↗
PubMedDate not supplied

In vivo evaluation of vena caval filters: can function be linked to design characteristics?

PURPOSE: To compare the five vena caval filters marketed in the United States and one investigational vena caval filter and to determine whether there is an association between their design and their in vivo function. METHODS: Four of each type of filter--Simon Nitinol (SN), Bird's Nest (BN), Vena Tech (VT), Greenfield stainless steel (PSGF), Greenfield titanium (TGF), and the investigational stent cone filter (NGF)--were studied for 60 days in 12 sheep. Radiographic and pathologic outcomes to be assessed included clot capture and resolution, vena caval penetration, position of the filter, thrombogenicity, and vessel wall reaction. RESULTS: Filters differed with respect to the number of clot-trapping levels and the interdependence of the legs. All devices were successfully placed. Intentionally embolized clot was captured. One VT and two SN filters migrated in response to clot capture. Resolution of thrombus was variable, and related to the design of the device. Fibrin webbing was widely present with the VT, BN, and SN filters but limited in the others. The VT and NGF filters demonstrated the most stable filter base diameter. CONCLUSIONS: The performance of vena caval filters differs with respect to clot resolution and mechanical stability. Interdependent filter limbs and single-stage conical capture sites appear to result in more favorable performance in in vivo studies.

Animals↗
PubMedDate not supplied

Basal cell adenoma in the parapharyngeal space: MR findings.

We report MR findings of a case of basal cell adenoma arising in the parapharyngeal space. On MR imaging, the mass was a well-circumscribed cystic and solid tumor with a thin fibrous capsule and intratumoral hemorrhage. It was confined to the parapharyngeal space, separating from the deep lobe of the parotid gland. The solid portion of the tumor was slightly hypointense/hyperintense to the muscle on T1-/T2-weighted images and was relatively well enhanced on Gd-enhanced T1-weighted images. The cystic contents of the mass were hyperintense on both T1- and T2-weighted images and were proven to be a hemorrhage.

Adenoma↗
PubMedDate not supplied

Evaluation of a new percutaneous stainless steel Greenfield filter.

PURPOSE: To evaluate a new percutaneous Greenfield filter with an alternating hook design and over-the-wire delivery system. MATERIALS AND METHODS: The alternating hook stainless steel Greenfield filter was evaluated in a prospective clinical trial between March 10, 1994, and January 27, 1995. Filters were placed in 75 patients in nine clinical centers and follow-up with radiographs and ultrasound scans was carried out at 30 days. RESULTS: Clinical trial results revealed successful placement in all patients. There were four cases of filter limb asymmetry (5.3%) without clinical sequelae, with one incidence of failure to span the cava. No significant migration was found. There were no clinically suspected pulmonary emboli, but one instance of probable caval penetration (1.7%) did occur. Caval occlusion was documented in three patients (5%). CONCLUSION: The percutaneous stainless steel Greenfield filter provides ease of insertion and improved deployment while maintaining the high standards of efficacy and safety associated with the standard and titanium Greenfield filters.

Adult↗
PubMedDate not supplied

The dissected aorta: percutaneous treatment of ischemic complications--principles and results.

PURPOSE: Describe the principles and results of percutaneous treatment of ischemic complications of aortic dissection. MATERIALS AND METHODS: Twenty-four patients with aortic dissection complicated by ischemic compromise of the liver or bowel (n = 15), kidney (n = 18), or lower extremity (n = 13) were evaluated by means of aortography, intravascular ultrasound, and manometry, and were treated percutaneously. Visceral arteries were classified as obstructed or nonobstructed. Obstruction was classified as static, in which the dissecting hematoma extended into and narrowed the lumen of a branch artery, or dynamic, in which the dissection flap prolapsed into the vessel origin or narrowed the true lumen (TL) above it. Treatment consisted of vascular stents alone (n = 4), or balloon fenestration (n = 20) without (n = 8) or with (n = 12) vascular stents. RESULTS: Obstruction was present in 77 arteries and was static in 12 arteries, dynamic in 45 arteries, static and dynamic in 17 arteries, and indeterminate in three arteries. Percutaneous treatment did not alter false lumen (FL) pressure, but reduced the peak systolic interluminal pressure gradient from 28 mm Hg to 2 mm Hg and restored flow in 71 of 77 arteries (92%). Six patients died within 30 days (25% operative mortality), none as a result of the procedure. Two additional patients died in follow-up from complications of an expanding FL. Technical complications in two patients due to altered hemodynamics after initial intervention were recognized and corrected percutaneously during the same procedure. CONCLUSIONS: Percutaneous fenestration and endovascular stent deployment are indicated to restore blood flow to arteries compromised by aortic dissection. The prognosis of patients is related to the ischemic injury sustained prior to the percutaneous interventional procedure and, in patients with acute type I dissection who have not undergone surgery, to the preoperative stability of the FL.

Adult↗
PubMedDate not supplied

Selective arterial infusion of vasoconstrictors for control of traumatic splenic hemorrhage.

The spleen of each of 20 mongrel dogs was traumatized by creating a wedge laceration, and selective arterial infusion was then performed with vasopressin in four dogs, pituitrin in eight, and epinephrine in eight. Infusion therapy with vasoconstrictors controlled the splenic hemorrhage in 19 of 20 dogs. The 15 dogs surviving the experimental period of four to eight weeks showed well-healed scars at the sites of lacerations. Three dogs had small contracted spleens as a result of massive infarction. The results of this experiment indicate that splenic hemorrhage in the experimental dogs can be controlled by selective infusion of pituitrin or vasopressin, but is more effectively controlled with epinephrine.

Animals↗
PubMedDate not supplied

Angiographic nephrectomy using iodinated contrast agent.

Diatrizoate meglumine and sodium (Renografin-76) was perfused in an obstructed renal artery in 13 dogs. Intense and prolonged accumulation of contrast agent ("contrast staining") was achieved in all animals. Repeat injection was frequently necessary to enhance staining. Renin output from the stained kidneys was lower than that from the opposite kidneys. Angiography at 14-18 weeks demonstrated a marked decrease in renal size in all dogs, with complete occlusion of the renal artery in two dogs. No collateral circulation was discerned. Grossly, all experimental kidneys were uniformly shrunken. Histologically, diffuse renal infarction was evident with coagulative necrosis. Contrast staining is an effective method for uniform destruction of renal tissue.

Animals↗
PubMedDate not supplied

Renal artery occlusion and infarction with Sotradecol.

Sodium tetradecyl sulfate 3% (Sotradecol) was perfused into a proximally obstructed renal artery in ten random-source adult dogs. In all animals, the intra-arterial injections of Sotradecol produced immediate thrombosis of the renal arteries. Angiographic studies, lasting up to ten weeks, on eight dogs demonstrated persistent occlusion. In one dog, unintentional thrombosis occurred in the opposite renal artery due to reflux of Sotradecol. Histopathologic studies showed total obliteration of the renal arteries through organized thrombosis, intimal sclerosis, and luminal collapse. In all dogs, the kidneys were not visible, and diffuse renal infarction was confirmed by histologic studies of five dogs.

Animals↗
PubMedDate not supplied

Experimental hepatic artery embolization with Gelfoam powder. Microfil perfusion study of the rabbit liver.

After hepatic artery embolization with Gelfoam powder in five rabbits, two colors of Microfil (silicone rubber solution) were perfused into the aorta and the portal vein to study hepatic microcirculation under a dissection microscope. In three of the animals, many intrahepatic arterial branches and portions of the hepatic sinusoids were perfused with the arterial Microfil (orange color), whereas in the other two animals no orange Microfil was found in the liver. In the three animals, occlusions of the hepatic artery were random in distribution and often segmental, and arteries as small as 50 microns in diameter were involved. In the latter group, levels of arterial occlusion could not be evaluated. Microcollaterals developed through the capsular artery, peribiliary arterial plexus, and vasa vasora of the portal vein.

Animals↗
PubMedDate not supplied

Indications for aortography. Radiography after blunt chest trauma: a reassessment of the radiographic findings associated with traumatic rupture of the aorta.

Indications for aortography in truncal trauma patients have expanded as reports of radiographic findings associated with traumatic rupture of the aorta (TRA) have proliferated. By studying to what extent these findings also occurred in trauma patients without TRA, we determined the utility of these findings in selecting patients for aortography. The detection of nine radiographic findings associated with TRA was tabulated in 173 patients undergoing arch aortography to rule out TRA from 1975 to 1980. Twenty-five of these had TRA. All patients with TRA under age 65 had a widened mediastinum (WM); this was the only finding that taken alone correlated significantly with TRA (P = 0.001). Only two of six patients with TRA over 65 had a WM. Other findings such as hemothorax, fracture of ribs 1 or 2, pulmonary contusion, or multiple rib fracture were more likely to be found in patients without TRA. Formal radiographic interpretation by staff radiologists detected more radiographic abnormalities than physicians caring for the patient emergencly, who had access to a junior radiology resident. However, these physicians were as successful as staff radiologists in detecting WM when it was associated with TRA. A widened mediastinum is the best single criterion for aortography in young trauma patients; all elderly persons with severe truncal trauma should probably have aortography even in the absence of mediastinal widening. Radiologic consultation is important for complete detection of thoracic pathology in trauma patients, but in this study late interpretation of more subtle findings did not detect additional patients with TRA.

Adolescent↗
PubMedDate not supplied

Diagnosis of renal vascular disease with MR angiography.

Renal magnetic resonance (MR) angiography allows accurate evaluation of patients suspected to have renal artery stenosis without the risks associated with nephrotoxic contrast agents, ionizing radiation, or arterial catheterization. Other applications of renal MR angiography are mapping the vascular anatomy for planning renal revascularization, planning repair of abdominal aortic aneurysms, assessing renal bypass grafts and renal transplant anastomoses, and evaluating vascular involvement by renal tumors. A variety of pulse sequences provide complementary information about kidney morphology, arterial anatomy, blood flow, and renal function and excretion. Three-dimensional gadolinium-enhanced MR angiography can be combined with several other sequences to produce a comprehensive approach to renal MR angiography. This comprehensive approach is designed to allow hemodynamic characterization of renal artery stenosis with a single MR imaging examination that can be easily completed in 1 hour. Three-dimensional gadolinium-enhanced MR angiography demonstrates the renal arteries along with the abdominal aorta, iliac arteries, and mesenteric arteries in a 20-30-second acquisition that can be performed during breath holding. Numerous projections are reconstructed from a single three-dimensional volume of data acquired with a single injection of contrast material to obtain perpendicular and optimized views of each renal artery.

Anastomosis, Surgical↗
PubMedDate not supplied

Glassy cell carcinoma of the uterine cervix. Cytologic features and expression of estrogen and progesterone receptors.

OBJECTIVE: To identify the cytomorphologic features and investigate the expression of estrogen receptor (ER) and progesterone receptor (PR) in glassy cell carcinoma (GCC) of the uterine cervix. STUDY DESIGN: A retrospective analysis of nine GCCs encountered at Korea Cancer Center Hospital between January 1990 and April 1999 was undertaken. The cervical smears were obtained prior to histologic diagnosis of GCC. The cytomorphologic and clinical features were reviewed, and the expression of ER and PR was investigated immunohistochemically on histologic sections. RESULTS: Smears of GCC were hypercellular and remarkably cohesive. The tumor cells were large and characterized by abundant granular cytoplasm, distinct cell membranes and round to polygonal, large nuclei with prominent nucleoli. In the background tumor diathesis and numerous inflammatory cells containing eosinophils were present. The inflammatory cells (mainly eosinophils) were intimately associated with tumor cells to form "granuloepithelial complex." Immunohistochemically, ER was identified in two of the nine cases and PR in one of them. CONCLUSION: Cytology of GCC has characteristic features that differ from those of other carcinomas or atypical reparative cells. Although there are deceptive mimics of GCC, the characteristic cytologic findings should prompt a diagnosis of GCC. ER and PR positivity was found in two cases (22%) and one case (11%), respectively, of GCC, suggesting that this tumor might be hormonally responsive.

Adult↗
PubMedDate not supplied

Differential diagnosis of adenoid cystic carcinoma from pleomorphic adenoma of the salivary gland on fine needle aspiration cytology.

OBJECTIVE: To evaluate the distinguishing morphologic features of pleomorphic adenoma and adenoid cystic carcinoma on fine needle aspiration cytology. STUDY DESIGN: A retrospective study was undertaken to compare the cytomorphology of 9 adenoid cystic carcinomas with that of 12 pleomorphic adenomas of the salivary gland among histologically proven cases. RESULTS: The most consistent finding for differentiating adenoid cystic carcinoma from pleomorphic adenoma in our study was the amount of cytoplasm of individual tumor cells. Plasmacytoid appearance is a reliable finding for pleomorphic adenoma, and it enables us to rule out adenoid cystic carcinoma. All 12 cases of pleomorphic adenoma showed tumor cells containing abundant cytoplasm in clusters and isolated cells, with plasma cell-like appearance in 9 cases, especially in isolated cells. In contrast with pleomorphic adenoma, most adenoid cystic carcinomas showed little cytoplasm. Hyaline spherical globules were found in four of nine adenoid cystic carcinomas but were not found in any case of pleomorphic adenoma. It was specific but not sensitive to adenoid cystic carcinoma. Fibrillary chondromyxoid ground substance and a mixture of epithelial cells with stroma were found in two-thirds of the pleomorphic adenomas in our cases. The pattern of cell clusters was helpful to differentiate pleomorphic adenoma from adenoid cystic carcinoma. Large, loose clusters with a spindle cell core suggested pleomorphic adenoma. Small, dense trabeculae with a smooth margin and dense clusters containing clear, round spaces were more suggestive of adenoid cystic carcinoma. Overall cellularity, proportion of isolated cells, orientation of cellular clusters and degree of cellular overlapping gave almost no help in making the distinction between the lesions. CONCLUSION: A plasmacytoid appearance of individual tumor cells with abundant cytoplasm was a reliable finding in pleomorphic adenoma for differentiating it from adenoid cystic carcinoma. Practically, nuclear features were not enough to distinguish the two lesions in isolated cases.

Adenoma, Pleomorphic↗