The vascular response induced by transmyocardial laser revascularization is determined by the size of the channel scar: Results of CO2, holmium and excimer lasers

BACKGROUND AND OBJECTIVES: To investigate the angiogenic effect of CO2, Ho:YSGG, and XeCl excimer TMLR in a rat model with morphologic characteristics of chronic myocardial ischemia. STUDY DESIGN/MATERIALS AND METHODS: Two channels (200-320 microm) were created per rat heart. After 14 days, vessel numbers and densities in and around laser scars were assessed. RESULTS: Capillary densities in the laser scars were equal between the three lasers ( approximately 130 vessels/mm2) but much lower than in control areas ( approximately 2,100 vessels/mm2). Vessel densities excluding capillaries were significantly higher in Ho:YSGG and CO2 scars compared to excimer scars, while only Ho:YSGG scars contained significantly more large vessels (diameter > or = 20 microm) than control areas. Only rarely, extension of vascular growth into adjacent myocardium was observed in any of the three groups. CONCLUSIONS: These results indicate that the angiogenic response following TMLR is limited to the channel scar and related to the scar size rather than the specific laser type.     

Outpatient metrizamide myelography: prospective evaluation of safety and cost effectiveness

A group of 228 consecutive patients undergoing metrizamide myelography was prospectively evaluated for postprocedure symptoms. The observed prevalence of these symptoms concurs with previously reported inpatient studies, with the most common sequelae being exacerbation or onset of spine or extremity pain, headache, nausea, and paresthesia. Limitation of administered dose of metrizamide in lumbar myelography may slightly reduce the occurrence of common symptoms, but withdrawal of contrast medium at the completion of examination had no impact on their occurrence. There was a higher occurrence of paresthesia in cervical myelography, but otherwise there was no significant difference in symptoms between cervical and lumbar studies. Outpatient metrizamide myelography can be performed with relative safety with the potential for significant cost savings.     

Low-speed rotational angioplasty in chronic peripheral artery occlusions: experience in 83 patients. Work in progress

Between December 1986 and October 1988, 83 patients with chronic peripheral artery occlusions were treated with a new technique. In 56 patients, the superficial femoral artery was completely occluded; in 21 patients, the popliteal artery; and in six patients, the iliac artery. The length of occlusion ranged from 5 to 35 cm (mean, 12.5 cm). The duration, estimated by history, was 5-48 months (mean, 16.5 months). In seven patients, durations of 6-36 months were documented angiographically. A flexible, blunt, motor-driven rotating catheter was introduced through an 8-F sheath, and rotational angioplasty was performed at low speed (up to 200 rpm). In 49 of 60 (82%) patients in whom this new technique was used as the primary intervention, the occlusions were successfully reopened. In 23 patients in whom conventional methods had failed more than 4 weeks earlier, the success rate for rotational angioplasty was 67% (12 of 18 patients); when the time interval was less than 4 weeks, only one of five patients was treated successfully. In none of the 83 patients did a perforation occur. This new technique can reopen chronic artery occlusions with a high degree of success and without the danger of vessel-wall perforation, even after failure of conventional techniques.