Mohs micrographic surgery is a precise method used to treat common skin cancers, such as basal cell carcinoma and squamous cell carcinoma. This technique involves removing the tumor layer by layer and immediately analyzing the tissue under a microscope to ensure complete cancer removal. Because the surgeon can examine 100% of the tumor margins, Mohs surgery offers the highest possible cure rate while preserving the maximum amount of healthy tissue surrounding the cancer. This detailed, tissue-sparing approach is particularly beneficial for cancers located on the face, ears, hands, and other cosmetically or functionally sensitive areas.
Anesthesia and Level of Consciousness
Patients are almost always awake during Mohs surgery, which is nearly universally performed using local anesthesia. The surgeon injects a numbing agent, typically lidocaine, directly into the area surrounding the skin cancer site. This ensures the patient feels no pain during the removal of the tissue layers.
Local anesthesia offers several benefits, including a much faster recovery time compared to general anesthesia. Since the patient is fully awake, they can cooperate easily with the surgical team throughout the process. General anesthesia is reserved only for extremely rare cases involving specific medical vulnerabilities or tumors that are exceptionally large or complex.
The Steps of Mohs Surgery
The procedure begins with the surgeon marking the visible tumor and surrounding skin with a surgical pen. After the local anesthetic is administered, the surgeon removes a very thin layer of tissue using a scalpel. The patient will feel pressure or pulling during this step but should not experience any sharp pain because of the numbing injection.
Once the initial tissue layer is excised, the wound is covered with a temporary bandage. The surgeon immediately processes the removed tissue in an on-site laboratory. This step involves freezing the tissue, cutting it into ultra-thin horizontal sections, staining the slides, and mapping the precise location of the tissue relative to the wound. If the microscopic examination reveals cancer cells still present, the entire process is repeated in subsequent stages until a cancer-free margin is confirmed.
Managing Downtime and Waiting Periods
A significant portion of the day is spent waiting for the laboratory analysis. After each layer of tissue is removed, the patient is escorted to a waiting area while the Mohs surgeon examines the tissue under the microscope. This downtime is necessary because the tissue processing and microscopic examination typically take about 60 to 90 minutes per layer.
Patients are encouraged to bring materials like books, electronic devices, or a companion to help pass the time. The surgical team ensures the patient has access to snacks, drinks, and bathroom breaks. This waiting period requires patience, as the entire process can take several hours, often lasting most of the day.
Immediate Post-Procedure Care
Once the surgeon confirms all cancer cells have been removed, attention shifts to repairing the surgical wound. The method of wound closure depends entirely on the size and location of the defect. Options range from stitching the wound closed, allowing it to heal naturally (secondary intention healing), or performing a skin graft or flap.
The wound is covered with a protective dressing, which the patient is instructed to leave in place for 24 to 48 hours to promote initial healing. The surgical team provides detailed instructions for initial bandaging, including when to change the dressing and how to clean the site. Pain management is achieved with over-the-counter medications like acetaminophen. Patients are advised to avoid strenuous activity, heavy lifting, or bending from the waist for at least a week to prevent stressing the sutures and impeding healing.