Ear wedges: Maintaining, understanding tissue orientation key to processing

Key Points

Williamsburg, Va. - In processing an ear wedge during Mohs micrographic surgery, maintaining proper orientation of the tissue helps keep the surgeon and technician working smoothly together, an expert says.

"When working on the ear, surgeons sometimes use wedges instead of standard Mohs layers if the tumor has infiltrated through the ear. Wedges can provide cosmetically great results and are easier to process," says Tanja Douglass, a Mohs technician and president of Torrance, Calif.-based Travel Tech Mohs Services, which provides Mohs technician services for Mohs surgeons in the western United States.

Because ear wedges contain many dimensions, however, maintaining proper orientation is the most difficult element of Mohs surgery for a technician, she says. But Ms. Douglass says proper training can make this task fairly straightforward.

Mapping

The first stage in processing an ear wedge involves mapping the specimen, which allows the technician and surgeon to stay on the same page in terms of knowing exactly where the tissue came from.

With proper orientation, Ms. Douglass says, "The doctor can read the slides and look at the map, and there's no confusion about where he is on the slides or on the ear."

Unfortunately, she says that in her experience, working personally with more than 80 Mohs surgeons, "Many technicians don't draw the map with the surgeon. Or the surgeon will map the specimen on his or her own."

However, she says it's extremely beneficial if the technician and surgeon draw the map together.

Bisecting

In prepping specimens, "One thing that's different about ear wedges is that you always have to bisect the specimen rather than processing it whole," which is a typical approach with tissue taken from other areas of the body, Ms. Douglass tells Dermatology Times.

Therefore, she says it's important that the technician learns to bisect correctly, without moving the tumor from its original location. Tips in this regard include always using a sharp blade and cutting in one clean swipe to minimize any misrepresentation of tissue.

And because ear wedges contain cartilage, she says, "Controlling the specimen when you're bisecting can be difficult." At Travel Tech, technicians practice such steps on pig tissue.

Margins

Once the tissue is bisected, "It's turned on its side so the bisected side is the one that's sticking up, and the true margins are against the cutting board when prepping the tissue," Ms. Douglass says.

"Mohs surgery is all about margins. The technician's job is to show the surgeon all the circumferential and deep margins from the tissue they removed from the patient," so surgeons will know where to take additional layers from if needed, she says.

"With Mohs surgery," Ms. Douglass says, "the surgeon will be able to say, 'at the two o'clock position, there's still a little tumor left.' Because of the mapping, the orientation and how the technician represents the tissue on the slide, the doctor will know exactly where to go back on the ear."

Regarding mapping, she says ear wedges require both a two-dimensional and a three-dimensional map. The three-dimensional drawing helps the surgeon and technician know if they're working in the back or front of the ear, for example.

"That's where the directional terms come in," she says.

For similar reasons, she says, "I always like to draw a picture of the ear where the wedge came from, then put the same markings on this drawing."

This further helps surgeons understand how the three-dimensional wedge corresponds with the two-dimensional slide, which Ms. Douglass says can be the source of much confusion.