Feasibility Study of a New Circular Anal Dilator for Transanal Hemorrhoidectomy

Historically, surgical hemorrhoidectomy has been effective at eliminating hemorrhoids but is associated with high complication rates and post-operative disability. The problems that are most common immediately after hemorrhoidectomy are severe pain, urinary retention, bleeding and fecal impaction. The most dreaded long term complications are anal stricture and fecal incontinence.

Stricture or narrowing of the anal canal after hemorrhoidectomy is the direct result of excising too much anoderm and mucosa. Even in circumferential prolapsed hemorrhoids, a standard three quadrant hemorrhoidectomy is all that is necessary. Mild anal stricture can be treated with a Hegar dilator but severe stricture requires a lateral internal sphincterotomy with or without a skin advancement flap. These operations are morbid and results are generally poor.

Anal sensation is partially impaired leading to some degree of incontinence of 50% of patients after hemorrhoidectomy. Persistent incontinence results from being over aggressive during the hemorrhoidectomy and excising muscle with the hemorrhoid during dissection.

The majority of these long term complications are solely dependent on surgical technique. The majority of hemorrhoidectomies performed today are still performed by non-specialty surgeons. They rely on various instruments during the surgery to perform the operation in the anal canal with adequate exposure but the most important instrument is the anoscope.

A variety of anoscopes are currently available, but the standard anoscope used for hemorrhoidectomy is the Hill-Ferguson. The Hill-Ferguson is a crescent shaped instrument that provides adequate exposure in the anal canal and allows the surgeon to perform a Ferguson hemorrhoidectomy, the standard of care for hemorrhoidectomy in this country. During this procedure an elliptical excision is begun at the perianal skin to include both external and internal hemorrhoids and is ended at the anorectal ring. A full thickness of mucosa and submucosa is excised and the surgeon should dissect superficial to the internal sphincter muscle. The strip of this excision should be no wider than 1.5 cm but currently nothing prevents the surgeon from exceeding this limitation or from taking muscle with the excision. The widely accepted Hill-Ferguson Anoscopes provide vast exposure but do not set any boundaries for the surgeon when performing this operation.