๐ ็ธฝ็ฎ้ ๏ฝ ๐ ่ฑๆๅๆ๏ผๆฌ็ฏ๏ผ ๏ฝ ๐ ๅฎๆด็ฟป่ญฏ ๏ฝ โญ ็ฒพ่ฏ็ญ่จ
Preoperative preparation and anesthesia
Preoperative preparation and anesthesia
A surgical marking pen is used to mark the punctum and the palpable margins of the cyst prior to local anesthetic infiltration, as local anesthesia may distort the cyst boundaries (Figs. 50-7 and 50-8).
Tegaderm, a transparent film dressing, may be applied overlying the cyst immediately after marking and prior to local anesthetic infiltration. This may serve to mitigate the risk of cyst contents or local anesthetic agent backsplash contaminating the injector. The film is removed after local anesthesia infiltration, and the area is cleaned and sterilized per standard protocol (Fig. 50-9).10
Injection of a local anesthetic agent may help to dissect the cyst from the surrounding tissue. If considerable fibrosis or scar tissue exists, little separation of the cyst from the surrounding tissue will occur. Care should always be taken not to inject directly into the cyst cavity, which may lead to cyst distention and possible rupture. Additional anesthetic can be infiltrated more deeply beneath the cyst as dissection and removal progresses, if necessary. Warning patient preoperatively that local anesthetic infiltration deep to the cyst may be incomplete may be worthwhile. Additionally, local anesthetic effect may be impeded in the acidic context of an infected cyst, though such cysts should generally not be approached surgically until the bulk of infection has been cleared through either incision and drainage or systemic antibiotic therapy.
Figure 50-7. A moderately-sized cyst is seen on the right cheek.
Figure 50-8. A surgical marking pen is used to mark the punctum and the palpable margins of the cyst prior to local anesthetic infiltration, as local anesthesia may distort the cyst boundaries.
Figure 50-9. Tegaderm, a transparent film dressing, may be applied overlying the cyst immediately after marking and prior to local anesthetic infiltration. This may serve to mitigate the risk of cyst contents or local anesthetic agent backsplash contaminating the injector. The film is removed after local anesthesia infiltration, and the area is cleaned and sterilized per standard protocol.