Translation from Le Lettre du Gynecoiogue, no. 291 – April 2004
TECHNIQUES OBSTETRICALES
The Kiwi Vacuum Delivery System: a simple extraction device, efficient and for single (disposable) use.
The instrumental extraction is clearly identified as a major risk factor of morti-morbidity (fatal illness) of the fetus and also responsible of an immediate and secondary maternal morbidity (including anal incontinence). Good practice rules for the instrumentation for the birth have been decided (1) and in substance they say that obstetricians should be competent in the use of forceps and obstetrical vacuum cup. It is also added that, in the perspective of reducing maternal lesions (tears), the vacuum delivery system should be considered as a first choice instrument. Of course, strict rules on using this instrument are necessary in order to avoid serious neonatal (postnatal) complications. However, learning how to use it seems easier than the forceps.
Until recently, when a team decided to develop their own vacuum delivery system in its unit, they had not only to acquire several cups which could be sterilised but also a vacuum engine. These technical necessities have probably limited, in France, outside medical training school notions, the development of this type of instrumental extraction.
All the surgical services are confronted with the problem of sterilisation of the instruments and a wide policy of encouraging the use of single use equipment is relevant today.
The obstetricians who are in favour of the obstetrical vacuum delivery system were waiting for a simple and efficient device for single use for a long time.
Kiwi Omni Cup vacuum delivery system (Clinical Innovations, Murray, Utah), is a single use vacuum system with a hand pump of which enables the user to get a vacuum easily under the cup and thus requires no engine to do so (picture 1). The flexible suction tube through which goes a traction cable is attached at the centre of the dome of the cup. On the traction cable, there are two marks for distance to the cup (6 and 11cm) which allows the extrapolation of the height of the presentation in the birth canal. This cup, which is 50mm in diameter, is built in rigid plastic and the traction handle is used as a vacuum pump with a depression gauge (efficient depression = 0.8 bar). On this hand pump there is a push button which allows the release of the vacuum which had been made.
The central position and the possibility of 180 degrees of the traction system prevent, during the unexpected failure of the suction cup, a rocking movement of the cup and that way avoid locking. Its plastic structure makes it a particularly light instrument.
This fetal extraction technique appears as efficient in the publications and comparable to the metallic suction cups without extra complications 12,3). It enables assisted birth of presentations of the posterior and anterior variety, and this up to the level of the middle station. By flexing the presentation, the suction cup in most cases mechanically leads to the front rotation of the posterior occipital varieties without excessive force. This seems all the more interesting that the big rotation with the forceps is condemned today (4) and that the extraction by these very forceps in occipital-posterior positions is a source of numerous serious perineal lesions. Like any other vacuum cup it is responsible for a low number of perineal lesions of high degree (5).
The light, autonomous and sterile features make in an instrument, which is easy to give to the obstetrician when he/she encounters difficulties of extracting the fetus during a caesarean. Its setting up under these circumstances only requires a limited access (50mm of diameter) and less than a minute to reach the depression which enables the traction (picture 2). Its low obstruction does not generally require to make the hysterotomy larger.
This single use autonomous vacuum delivery system seems very interesting and should enable the spread of this way of instrumental extraction in our country.