Mohs micrographic surgery is a specialized procedure designed to remove skin cancer while preserving healthy surrounding tissue. This technique involves removing thin layers of tissue, which are immediately examined under a microscope until only cancer-free tissue remains. Mohs surgery has a very high success rate, with cure rates reaching up to 99% for new skin cancers. The procedure inevitably leaves a wound, or defect, that requires immediate attention for proper healing. The method of closing this defect is highly variable and depends on its size, depth, and location on the body.
Why Closure is Necessary After Mohs
The wound created by Mohs surgery is precisely defined and usually deeper than a standard excision, requiring careful reconstruction. Closure is an important step that serves multiple purposes beyond simply bringing the skin edges together. A primary reason for closure is to promote functional healing and protect the underlying tissues from infection.
Leaving a wound open can lead to poor healing, increasing the risk of complications and extending the recovery period. Optimizing the cosmetic outcome is also a significant consideration, especially since Mohs is often performed on the head and neck. The chosen closure technique is heavily influenced by the defect’s location, as areas like the nose, eyelids, and lips require methods that preserve their complex structure and function.
Simple Stitches and Direct Repair
Simple stitches, or linear closure, are a common method of repairing the Mohs defect. This technique involves drawing the wound edges together and securing them with sutures to create a straight incision line. It is utilized for smaller defects where the surrounding skin is loose enough to stretch without causing excessive tension or distorting nearby features.
The surgeon often performs undermining, which involves separating the skin from the underlying tissue. Undermining helps release tension on the wound edges, allowing them to be pulled together more easily and resulting in a less noticeable scar. Sutures are placed in two layers: dissolvable stitches are used deep within the wound for structural support, and non-dissolvable stitches are placed on the surface.
Advanced Reconstruction Options
When a defect is large, deep, or located in an area with little skin laxity, simple linear closure is often inadequate, necessitating more complex reconstructive options.
Skin Flaps
One advanced technique is the use of a skin flap, which involves surgically lifting and moving adjacent healthy skin tissue into the defect. The flap remains partially attached to its original location, maintaining its own blood supply. Flaps are frequently used on the face to cover complex defects and yield excellent functional and cosmetic results.
Skin Grafts
Another option is a skin graft, where skin is completely removed from a distant donor site and transferred to cover the surgical wound. Full-thickness skin grafts are commonly used after Mohs and are taken from areas like the neck, collarbone, or behind the ear. Unlike a flap, the graft must establish a new blood supply from the recipient site over the first few days to survive.
Secondary Intention
In certain cases, especially on concave areas like the nasal ala or inner ear, the defect may be left to heal naturally through a process called secondary intention. This method allows the wound to granulate and close from the bottom up. This often results in a good cosmetic result without the need for stitches or grafts.
Post-Closure Healing and Follow-Up
The post-operative phase focuses on protecting the closure site to ensure optimal healing and minimize the appearance of the scar. Patients are typically sent home with a pressure dressing, which helps control minor bleeding and provides a protective barrier. For the first one to two weeks, patients are advised to avoid strenuous activities or heavy lifting that could put tension on the wound.
Non-dissolvable surface sutures are usually removed about 5 to 14 days after the procedure, depending on the repair location. During this initial recovery period, the wound must be kept clean and moist, often with a petroleum-based ointment, as this promotes faster healing and reduces scarring. Patients should monitor the site for signs of infection, such as excessive drainage, fever, or persistent pain. Full maturation of the scar can take up to a year, with significant fading occurring gradually.