Study of a New Circular Anal Dilator

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.

Over the last several decades few modifications have been introduced to alter the contour of the anoscope in an attempt to reduce the complications of post-operative stricture and incontinence. Furthermore, the current anoscopes lack the ability to outline a precise excision path for the infrequent anorectal surgeon or for the non-specialist in the community.

Recently, Ethicon surgical has developed an anoscope that outlines the precise path for hemorrhoid excision without the possibility of excision greater than 1.5 cm of anoderm with each excision. This instrument allows the standard of care Ferguson hemorrhoidectomy to be performed and does not alter the steps of the operation. The presumed advantages are the ability of the instrument to guide an accurate dissection and also to decrease the overall time it takes to perform hemorrhoidectomy. It has been tested in several porcine models. Operative times, tissue excised, and evaluation of the suture line were addressed during these trials and there were no instances of bleeding or excessive tissue excision.

The study design will be a prospective feasibility trial. Patients who are scheduled for operative excisional hemorrhoidectomy will undergo their planned procedure according to the standard of care which is a Ferguson hemorrhoidectomy. The only new variable introduced will be the application of a new anoscope to facilitate the dissection. Other than the new anoscope all pre-operative, intra-operative, and post-operative guidelines consistent with the current standards will be followed. The primary goal is to confirm that the new anoscope permits standard hemorrhoidectomy, and to obtain phase I data confirming that this novel anoscope is safe and efficacious in the performance of a Ferguson hemorrhoidectomy.