[Bipolar irrigation forceps. Initial experiences with a new device in high frequency surgery]. / Bipolare Spülpinzette. Erste Erfahrungen mit einer Neuentwicklung in der Hochfrequenzchirurgie.

PROBLEM: During most surgeries, tissues are coagulated by a high-frequency current in order to stop the bleeding. Usually, bipolar forceps are used for this procedure. Until now it could not be avoided, however, that the biotissue would adhere to the forceps ends making hemostasis more difficult to achieve. Can this negative effect possibly be avoided? MATERIAL AND METHOD: A newly developed bipolar irrigation forceps spilling out a 0.9% sodium chloride solution during the coagulation process has been designed to avoid this disadvantage. The irrigation forceps has been tested and evaluated experimentally in surgery as well as clinically. RESULTS: The irrigation liquid selected is a 0.9% sodium chloride solution. Thermal imaging during biotissue coagulation has shown that the tissue heats up more and faster with flushed coagulation, and that the tip of the forceps heats up less than with unirrigated coagulation. In both experimental-surgical as well as in clinical tests it was possible to stop the biotissue sticking to the ends of the forceps. This effect was also confirmed histologically. CONCLUSION: Since other methods of avoiding the sticking effect during tissue coagulation by a high-frequency current have not been successful until now, the bipolar irrigation electrode is a promising new development. It helps the surgeon to work more efficiently and safely without having to adapt to big changes, and, at the same time, it reduces the risk of complications.

3-Amino- and 5-aminopyrazoles with anticonvulsant activity.

New 3-amino- and 5-aminopyrazoles were synthesised. 3-Aminopyrazoles exert a strong anticonvulsant effect, 4-Chlorophenyl-3-(morpholin-4-yl)-1 H-pyrazole 2 distinctively blocks sodium channels and is strongly effective in the Maximal Electroshock Seizure (MES) test.

Synthesis, anticonvulsant activity, and structure-activity relationships of sodium channel blocking 3-aminopyrroles.

Starting from the corresponding acetophenone and glycine derivatives, a series of new 3-aminopyrroles was synthesized in few steps. Using this procedure with hydrazine and hydroxylamine instead of the glycinates provides access to 3-aminopyrazoles and 5-amino 1,2-oxazoles. The various derivatives were tested for anticonvulsant activity in a variety of test models. Several compounds exhibit considerable activity with a remarkable lack of neurotoxicity. 4-(4-Bromophenyl)-3-morpholinopyrrole-2-carboxylic acid methyl ester, 3, proved to be the most active compound. It was protective in the maximal electroshock seizure (MES) test in rats with an oral ED50 of 2.5 mg/kg with no neurotoxicity noted at doses up to 500 mg/kg. Compound 3 blocks sodium channels in a frequency-dependent manner. The essential structural features which could be responsible for an interaction with an active site of the voltage-dependent sodium channel are established within a suggested pharmacophore model.

[The bipolar needle electrode in surgical laparoscopy. Initial technical experimental and clinical results]. / Die bipolare Nadelelektrode in der operativen Laparoskopie. Erste experimentell-technische und klinische Ergebnisse.

To date the tremendous spread of operative laparoscopic procedures associated with monopolar high-frequency techniques has lead to an increase in complications caused by monopolar leakage currents. Experimental-surgical measurements on minipigs have shown no significant leakage currents in clinical relevant power range during laparoscopic application of a bipolar needle electrode as compared to monopolar electrodes. Practicability and safety of the bipolar electrode was proven in 100 operative laparoscopies for organ preserving or reconstructive surgery. In summary, with the new laparoscopic bipolar needle electrode a secure surgical instrument is available, with which finest tissue handling and minimal thermal damage feasible.