Comparison of expandable electrodes in percutaneous radiofrequency ablation of renal cell carcinoma.

OBJECTIVE: To compare two different expandable electrodes in radiofrequency ablation of renal cell carcinoma. METHODS: Percutaneous ablation was performed at two centers using either an expandable 7F umbrella-shaped LeVeen probe (diameter 2-4 cm) and a 200-W generator (group A), or an expandable Starburst XL electrode with a 150-W generator (group B). From each center, eight patients with one tumor each were matched retrospectively with regard to tumor volume, which was 9.71+/-6.43 cm3 for group A and 8.74+/-4.35 cm3 for group B (mean tumor diameter: 2.47+/-0.9 cm versus 2.50+/-0.4 cm, respectively). An unpaired t-test showed no significant difference in tumor volume between the two groups (p=0.820). RESULTS: Sixteen patients with 16 tumors were treated. The primary technical success of radiofrequency ablation was 94% (15 of 16 patients). After retreatment of residual tumor in one patient from group B, secondary technical success was 100%. No major complications were observed. The resulting mean volume of the almost spherical necroses was 21.1+/-9.1 cm3 versus 14.6+/-6.7 cm3 for groups A and B (diameter of necrosis: 3.5+/-0.7 cm versus 3.1+/-0.6 cm, respectively). A Mann-Whitney U-test showed no significant difference in necrosis volume between the two groups (CI [-0.215; 0.471]; p=0.2892). The calculated shape value of S (ratio of length to height of the coagulation necrosis) was 0.9+/-0.1 and 1.0+/-0.1 for groups A and B, respectively. No local recurrence was observed during a mean follow-up of 14.8+/-11.6 months, while extrarenal tumor progression occurred in three patients. CONCLUSIONS: No significant differences in coagulation volume and shape were found after RF ablation of renal cell carcinoma using two different expandable electrodes. To avoid local recurrence, however, accurate placement of probes and appropriate expansion of the electrode is necessary.

[Effect of a new 10% hydroxyethyl starch solution HES/270/0.5 on blood coagulation, blood loss and hemodynamics in comparison with 3.5% PPL]. / Einfluss einer neuen Hydroxyäthylstärkelösung 10% HES/270/0,5 auf Blutgerinnung, Blutverlust und Hämodynamik im Vergleich zu PPL 3,5%.

20 patients scheduled for total hip replacement were given 1,000 ml of a new preparation of 10% hydroxyethylstarch (HES) (MW 270,000: 0.5) preoperatively. They were compared to a group of 20 patients who received 1,000 ml of 3.5% plasma protein solution (PPS). HES caused a more pronounced hemodilution than PPS. With HES, central venous pressure (CVP) rose significantly higher than with PPS. PTT was significantly prolonged in the HES but not in the PPS group. TT was significantly reduced by HES in comparison to PPS. PT (Quick-value %) and fibrinogen levels showed no difference in both groups. Blood loss and transfusion volume were comparable to HES and PPS until 24 h after the operation. One patient showed generalised flush after HES. This HES preparation is a colloid with volume-expanding properties and appears to be without clinically apparent effects on coagulation (up to a volume of 11).

[Detection of bronchial hyperreactivity especially in exercise asthma using cold air hyperventilation provocation, free walking and acetylcholine]. / Zum Nachweis der bronchialen Hyperreaktivität besonders beim Belastungsasthma mittels Kaltlufthyperventilationsprovokation, freien Laufens und Azetylcholin.

In 92 children with different severity of bronchial asthma, a provocation by hyperventilation with cold air has been performed. Forty seven percent of the patients reacted with significant changes of RvD, of RoS, and of FEV1. All patients with negative response to cold air (53%) showed a significant increase of Ros after the inhalation of acetylcholine (threshold value: less than or equal to 0.1%). Eighty percent of the examined asthmatics with negative reaction to cold air reacted after free running with a significant increase of Ros. Thus, the hyperreactivity to a stress by cold air was no general or regular phenomenon in the patients with bronchial asthma investigated by us. There was also no correlation between complaints triggered by exercise reported in the anamnesis, the results of provocation tests using cold air, and the results of respiratory function test after free running.