Hammer and gouge mastoidectomy for acute mastoiditis - Vula ...

appearance of an egg. The spine of Henléremains and is the only really importantlandmark.Colour: Normally the bone appears whiteor oozes blood through the porous portionsof the retromeatal region. However, inmastoiditis the external cortex bleedsdiffusely due to the deep inflammatoryprocess. If there is underlying empyema,the wall appears bluish.4 th cut: 1cm behind 1 st , thus completinga circle of trephinationThe 1 st 3 taps of the gouge areperpendicular to the bony surfaceThe 4 th tap is applied obliquely toavoid the lateral sinus which may besuperficial or prominent.Surface: Some irregularities may appearalong the surface of the mastoid. Theseoften consist of inflammatory granulationswhich are apparent through the externalposterior petrosquamous suture or of afistula, which may be verified with the aidof a probe. The existence of a fistula issought wherever the incision hasuncovered free pus.Fourth Step: Trephining - Exploration ofSuperficial Antral RegionA large gouge is placed immediately belowthe linea temporalis (Figure 8). It is heldbetween the thumb and first two fingers,with the ring finger serving as a brake. Theinstrument is held in the position shown inthe illustration, being directed vertically atright angles to the bone surface.Site of Trephination: If a fistula is presentand is at the level of the antral region or itsimmediate vicinity, the trephine isperformed at that level. If no fistula existsor is very far from the antral region, thetrephining is done as follows. An area ofapproach is outlined with the gouge byapplying it above and behind the canal atthe following points (Figures 9, 10):Figure 8: Trephining and exploring antralregionFifth Step: Exploration of SuperficialSubantral Region and TipAfter trephining and curetting thesuperficial antral region, the gouge isdirected toward the inferior portion of themastoid, making a superficial verticaltrench. The instrument is held between thethumb and first two fingers of the left handwith the two remaining fingers resting onthe bony surface to provide control and toavoid dangerous slip of the gouge.1 st cut: 2 - 3mm. behind spine of Henlé2 nd cut: just below linea temporalis3 rd cut: parallels, but 1cm. below 2 ndcut5