Patients are referred for outpatient surgery when the warts or lesions are not responsive to other treatments, for very large volume of disease, or if there is any suspicion for cancer or HSIL that cannot be found due to the presence of large amounts of warts.

Surgical fulguration involves treating the lesions with an electric needle and is the most commonly used surgical intervention.

During the surgery, the colorectal surgeon and HRA provider will perform an in-depth examination or treatment while someone is anesthetized or very heavily sedated in the operating room. Surgery is usually required for only a small percentage of patients being treated for anal HSIL. These include:

1. Lesions that are so extensive that they cannot be treated by any of the other methods described in the treatment section. Patients who have a lot of intra-anal warts or warts that are bulky in size or involve nearly the entire circumference of the anal canal and/or the warts extend out to the perianal skin are probably best treated in the operating room.
2.  Lesions are so large that they cannot be sufficiently biopsied in the office to establish or exclude a diagnosis of cancer to the satisfaction of the clinician.
3.  Lesions are so large that extensive excision is required.

The advantage of surgery is that under anesthesia, not only is the patient sedated and relaxed, but the sphincter muscle is also relaxed and dilated, which allows better exposure and provides a better opportunity to visualize any abnormalities. This approach also provides the ability to take larger specimens if necessary.