Issel E P
Zentralbl Gynakol. 1977;99(8):487-97.
By means of schematic illustrations we demonstrate the working point of the power of labour, obstetrical forceps and vacuum extractor, The bones of the fetal skull are by sutures movable fastened together. Every extraction so will rise the intracranial pressure of the fetus, because the resistance of the birth canal tissues must be overcome. This for the extraction needed power and rising of the intracranial pressure is independent from the instrument with which the extraction is carried out. It is impossible to make a "cage" around the fetal head with the Shute forceps during extraction, to protect the fetal head from the extraction power. Another question is, that some instruments (included vacuum extractor) can limit the used power. By using forcipes with crossed lock without fixation the forces for extraction are not limited and there is a need of better operative technic. By the comparison of the forcipes from Shute, Naegele and Zweifel we can summarize, that for success is decided the indication and good operative technic and not the instrument. Every instrument for vaginal extraction has advantages and disadvantages in different obstetrical situations.
通过示意图，我们展示了产力、产钳和真空吸引器的作用点。胎儿颅骨的骨头通过缝线可活动地固定在一起。每次牵引都会升高胎儿的颅内压，因为必须克服产道组织的阻力。这种牵引所需的力量和颅内压的升高与进行牵引所使用的器械无关。在牵引过程中，用舒特产钳在胎儿头部周围做一个“笼子”来保护胎儿头部免受牵引力是不可能的。另一个问题是，一些器械（包括真空吸引器）可以限制所用的力量。使用无固定交叉锁的产钳时，牵引力量不受限制，需要更好的手术技巧。通过比较舒特、内格尔和茨魏费尔产钳，我们可以总结出，成功取决于适应症和良好的手术技巧，而不是器械。每种阴道牵引器械在不同的产科情况下都有优缺点。
