Interstitial Laser Photocoagulation with Diode Laser Unit in Bovine Liver

PURPOSE: To evaluate the extent of tissue coagulation during interstitial laser photocoagulation (ILP) innormal bovine liver, using a diode laser unit and various parameters, and to determine whether the procedure isapplicable to clinical practice.. MATERIALS AND METHODS: Using an 18-gauge needle, experimental interstitiallaser photocoagulation (ILP) was carried out in normal bovine liver. On the basis of differing parameters, threegroups were established. For group I, a single photofiber with laser power of 1, 3 and 5 watts and an exposuretime of 60, 180, 300, 420 or 600 seconds was used. For groups II and III, four needles were fixed at a distance of1cm and 1.5cm ; in each case a needle fixation device was used, as well as a laser distributor for simultaneouslaser exposure of photofibers. As a control, four photofibers were placed as for groupIII, but to compare groups IIand III, each photofiber was exposed to a laser of 3 watts 300 seconds, without using a laser distributor. Toevaluate the range of tissue coagulation, specimens were analyzed both with regard to cross-sectional grossfindings and histopathologically . RESULTS: The largest diameter of thermal coagulation necrosis in Group I was15x15mm, and this was ball-shaped. Coalescence of coagulation between each photofiber was observed in Group II,and this was up to 25 mm in diameter. In Group III and controls, coalescence was not found, though the extent oftissue coagulation increased with increasing wattage and exposure time. The extent of charring at the center ofcoagulation also increased with increasing wattage. Smoke bubbles emanating from the coagulation area wereobserved, and during ILP involving a single photofiber, increased from 3 watts, applied for 300 seconds.CONCLUSION: Using an 8-gauge needle and a diode laser ILP, we have shown that a range of tissue coagulationacutely ablates normal bovine liver. In selective cases, the procedure could be applied to clinical trials.

Evaluation of Chronic Patellar Tendinitis by Utrasonography and MR Imaging

PURPOSE: To evaluate the usefulness of magnetic resonance imaging(MRI) and ultrasonography(US) for thediagnosis of jumper's knee in high school basketball players. MATERIALS AND METHODS: In order to detect clinicalcases of jumper's knee, 40 sites of patellar tendon in 20 knees of ten basketball players were assessed by anevaluation of personal history and physical examination. US and MRI were used for detecting compatible findings ofthis condition ; the diagnostic criteria were hypoechoic focus with focal thickening as seen on US, and increasedsignal intensity with focal thickening as seen on MRI. As an early finding of jumper's knee a new sonographiccriterion of focal hypoechoic focus with or without focal thickening, was also applied. RESULTS: At 19 of 40sites(48%), clinical jumper's knee was diagnosed. For the detection of this condition according to known cliteria,sensitivity and specificity were, respectively, 63% and 100%(US) and 32% and 90%(MRI). Using the new criterion,the sensitivity and specificity of US were 84% and 76%, respectively. CONCLUSION: On the basis of known US andMRI criteria for jumper's knee, the sensitivity and specificity of US were higher than those of MRI. We suggestthat hypoechoic focus without focal thickening oas seen on US, is an early finding of jumper's knee.

Intra-arterial Port Implantation for Intraarterial Chemoinfusion

PURPOSE: To evaluate, using various port systems, the technique and complications of intra-arterial portimplantation in visceral (mainly hepatic) arteries for intra-arterial chemoinfusion. MATERIALS AND METHODS: Weretrospectively evaluated 30 cases of intra-arterial port implantation in 29 patients. Angiography was performedin all cases, and insertion of an implantable polyurethane port catheter was followed by angiographic exchangewhich, utilizing a .035" hydrophilic guide wire, targeted the artery. If a change in the direction of flow wasrequired, arterial flow control was performed, using an enbolie coil. In order to insert the subcutaneous portchamber, an incision approximately 4cm long was made at the puncture site and subcutaneous tissue was dissected.The port chamber was inserted into the subcutaneous pocket and fixed with a black-silk tagging suture. When thefemoral artery was punctured, the port chamber was inserted into the supra-or infrainguinal area; when the leftsubclavian artery was used, the port chamber was inserted into the lateral one third of the left clavicle. Theport systems used in the procedure were as follows : 5.8F Port-A-Cath (SIMS, Deltec, U.S.A.)(n=20) ; 5.2F A-Port(Therex, U.S.A.)(N=5); 5F PU-Anthron(Deny, Japan)(n=4) ; 5.2F R-Port(Therex, U.S.A.)(n=1). The subcutaneouschambers were inserted into the infrainguinal (n=22), suprainguinal (n=6) or subclavian area(n=2). RESULTS: Theprocedure was technically successful in all 30 cases. Port catheter tips were located in the hepatic arteryproper(n=11), the right hepatic(n=9), gastroduodenal (n=6), common hepatic (n=2), inferior mesenteric (n=1) andinternal iliac artery(n=1). In 12 cases, flow was controlled using embolic coils. Follow-up study was performed in23 cases, with a mean follow up period of 55.8 (11-161) days. Complications were noted in four cases ; two wereprocedure related and two were catheter related. CONCLUSION: Intra-arterial port implantation is a safe procedureand can be performed easily by skilled radiologists; long-term observation is, however, still needed.