Procedures

You will likely see a lot of biopsies performed during your rotation. Always feel free to grab a pair of gloves. It shows that you are engaged and residents/attendings are more likely to ask you to help with something! Additionally, you may 1) gather materials and 2) practice biopsies. The two main types include punch and shave. You will likely also see cryotherapy to treat lesions such as warts and actinic keratoses.

Punch Biopsy:

Equipment: Lido+/-epi, Q tips, pick-ups, suture scissors, needle driver, suture, punch tool, gauze, alcohol swab, surgical marking pen, wound cover, sample collection jar, vaseline, band aid. Sterile prep for larger biopsies requiring deep sutures (sterile field, betadine/chlorhexidine, sterile gloves)

Procedure:

  • Mark with surgical marker
  • Clean skin using EtOH, povidone, or chlorhexidine/Hibiclens (avoid near eyes and ears!)
  • Infiltrate with lido to raise a wheal. You can use a little more lido that you would for a shave biopsy (see below). Give it a minute to take effect (load needle driver while waiting). You can test if the patient is numb by tapping the anesthetized area with the lido needle and asking if they feel anything sharp.
  • Stretch skin and rotate punch through dermis to fat.
  • For hand or skin with superficial vessels: Move the skin away from the vessels or pinch up the skin.
  • Snip the base (fat). 
  • Close with single interrupted sutures (4-0 Ethilon is generally the standard suture for punch closure).
  • Instruct patient on wound care (keep area dry for 24 hrs, daily vaseline and bandaid, avoid lifting or strenuous exercise involving that area, monitor for signs of infection) and suture removal (2 weeks as a general rule, 1 week for the face). 

Shave Biopsy:

Equipment: Lido+/- epi, alcohol swab, blade, pick-up, drysol, q-tips, gauze, vaseline and bandaid

Procedure:

  • Mark with surgical marker
  • Clean skin using EtOH, povidone, or chlorhexidine/Hibiclens (avoid near eyes and ears!)
  • Infiltrate with lido to raise a wheal, give it a minute to take effect (while you set up remaining items).
  • Options for blades:
    • Dermablade (blue blade), a curved blade, great for flat lesions, allows you to enter at 30˚, flatten out, and then exit at 30˚ to get adequate dermis
  • Hold pressure with gauze. Achieve hemostasis with drysol or Monsel’s solution on q-tip. 
  • Clean site, cover with vaseline and a band-aid or pressure-gauze.

Cryotherapy:

Equipment: cryogun (contains liquid nitrogen)

Procedure: 

  • Identify the area to be treated.
  • Generally no local anesthesia is needed.
  • Do a little test spray away from the patient to ensure cryogun is working properly.
  • Aim and spray liquid nitrogen onto target lesion. Avoid spraying surrounding skin as this can be painful. Sprayed areas turn white (frozen). The duration of spray depends on the lesion and its thickness, but usually five seconds is sufficient.
  • Some lesions may require 2 “freeze-thaw” cycles: Wait for treated areas to return to normal color (thaw) and respray.