Lateral internal sphincteromy for treatment of anal fissure

Lateral internal sphincterotomy (LIS)

Lateral internal sphincterotomy for treatment of anal fissure

The lateral internal sphincterotomy is considered the gold standard for treatment of anal fissures all over the world. It’s also recommended by the American Society of Colon and Rectal Surgeons (ASCRS). It was first introduced by Eisenhammer in 1951. The goal of the operation is to promote healing by decreasing the resting anal pressure and breaking the cycle of spasm and pain. There are some variations of the lateral sphincterotomy. It can be performed with an open or closed technique. The procedure itself is done under anesthesia (general or regional).

The open technique is not as popular nowadays. The surgeon would make a direct incision, exposing the intersphincteric groove. Then the internal sphincter would be carefully divided. The wound is closed with a suture.

The closed technique utilizes a scalpel to laterally divide the internal sphincter. The division is usually up to linea dentata. The closed technique has been demonstrated as safer and less postoperative care is required.

However, both methods could lead to some complications. These include postoperative hemorrhage, perianal abscess, anal fistula, prolapsed hemorrhoids, and fecal incontinence. The most serious of them being long-term fecal incontinence. Numerous studies have reported different results, with postoperative incontinence in ranges from 0% to 30%. Patients will usually complain of inability to control gas, mild soiling of the underwear or even uncontrolled bowel movements. Most of these complications are temporary and to be expected. The rate of persistent fecal incontinence is usually as low as 5%.

Researchers have noted that the reason for incontinence after LIS surgery is the length of the incision and the amount of internal sphincter divided. The internal sphincterotomy should be tailored according to the patient’s needs, as in women the internal sphincter might be shorter due to anatomical differences of the anal canal. Careful examination is needed before the division. Special attention should be paid to women who gave vaginal birth, as incontinence rates are higher in this specific group.

Postoperative procedures

Pain relief is immediate after the procedure. Studies have shown that LIS is effective in more than 95% of the cases. Hospital stay is short as the operation can be done as an outpatient procedure in the office. Recovery is light and lasts from 2 to 4 weeks. Physicians will usually see the patient 1 month after the procedure. The postoperative course is aimed at keeping the stool soft and easy to pass. Here are some tips:

  • Switch to a high-fiber diet and drink at least 64-70 oz of water (or more depending on the weight).
  • Dip into hot water or sitz baths for 10-15 minutes, two-three times per day.
  • Additional topical agents are not required. You shouldn’t apply any other agents used for the treatment of anal fissure. This can actually lead to incontinence.
  • Taking natural stool softeners of bulk-forming agents, such as psyllium fiber or unprocessed bran will aid the effort.

Other complications

Some complications may arise from the presence of other anorectal diseases, mainly large internal hemorrhoids. One of the complications after lateral sphincterotomy is prolapsing hemorrhoids. The surgeon should inform the patient and perform hemorrhoidectomy to excise any adjacent hemorrhoidal tissue. This will help avoid any further complications. If the chronic fissure has developed any sentinel piles or hypertrophied anal papillae, they can be removed.

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