a An irregular fissure which might be of some concern. b Epidermoid cancer of the anus. c Adenocarcinoma of the anus. d Lymphoma. e Melanoma of the anus. f Crohn’s disease of the anus
These would include large or irregular fissures, possibly located off the midline, multiple fissures, and fissures with edematous piles at the anal opening and fissures not associated with anal stenosis or constipation. Diseases that should come to mind in such a situation would be Crohn’s disease or anal neoplasm. To proceed with a partial lateral internal sphincterotomy in any of these situations could be catastrophic. If any operation is to be done in such a situation it is an examination under anesthesia and biopsy.
Surgery is almost never recommended for patients with an acute anal fissure. It is thought that acute anal fissure will often resolve spontaneously or with minimal medical intervention and that only a small proportion would evolve into a chronic fissure. Diagnostic criteria for acute anal fissure are the absence of the findings described above, that is a flat lesion with a red base, friability, and a short symptom history (Fig. 5.3).
This fissure can either be an acute fissure, or a chronic one if present for a longer time. The findings in Fig. 5.1 do not develop in all chronic fissures
This in fact is another puzzling problem in anal rectal surgery in that to diagnose chronic anal fissure requires only one of any of the findings described above, including simply a longer symptom history. So a fissure that looks in every way acute but that has been causing symptoms for six months is a chronic anal fissure. But what is the threshold? In fact it is different in almost every publication on this topic ranging from two weeks to three months. Symptoms of anal fissure often wax and wane so that the short symptom history may have been preceded by similar symptoms many months earlier, which would categorize this as a chronic fissure . This topic will be revisited at the end of the chapter.
Incontinence, a History
Anal fissure is not really mentioned by any ancient author. Sushruta, Hippocrates, and Galen all write extensively about hemorrhoids and fistula including surgical treatment. This was usually cauterization, and ulcers are mentioned but never separated from hemorrhoids or fistula. Abū Bakr Muḥammad ibn Zakariyyā al-Rāzī does specifically mention fissure but felt it was due to constipation and was treated with laxatives . John of Arderne does mention fissuring associated with tenesmus but felt that it was secondary to piles rather than a specific diagnosis . The treatment for fissure alone was nonsurgical.
It was not until the nineteenth century that fissure seems to be recognized as a specific diagnosis and that surgical intervention was needed for its cure. The birth of sphincterotomy was attributed to Alexis Boyer’s eleven volume Traitē des Maladies Chirurgicales published between 1818 and 1826 . The operation described is very little different from that which is performed today. The extent of sphincterotomy is not delineated. It is also not in most publications today. In a very thorough and fascinating book by Bodenhamer about anal fissure published in 1868, he writes that Ambrose Pare may have described the same operation and Albucasis described a more conservative incisional approach at the end of the tenth century . The number of surgeons actively involved in investigating the surgical treatment of fissure by the time of Bodenhamer and communicating their results was outstanding. Not only efficacy in pain relief and healing were described but also harms of the procedures including incontinence. The procedure of Boyer was regarded as too extensive and a lesser incision recommended, especially for continence preservation.
Another approach described in this book above is forced dilation as a method for relieving the outlet obstruction associated with fissure. One operation of some note was that of Maisonneuve who inserted his whole hand and then closed his fist upon withdrawal. The risk of incontinence was obviously recognized with this procedure and so lesser dilatations were investigated, including two thumbs stretch to the ischial tuberosities, also found to have a high risk of incontinence and finally just two index fingers inserted until a release was palpated. All that these surgeons seem to have been lacking in their investigations were the statisticians.
In the 1920s an old approach got a new name: pectenosis . The previously described internal sphincter fibers were thought to have undergone fibrosis, the so-called pectin band, through chronic congestion. The preferred method of treatment was to incise the fibers, apparently away from the fissure in most descriptions, until the anus could accommodate a two finger insertion, a much more conservative procedure than Maisonneuve’s or Boyer’s procedures. It was subsequently found that the presumed fibrosis was intact spastic internal sphincter fibers. By the late 1930s, attention had shifted to the external sphincter with injections or actual division of external fibers by Gabriel . Kilbourne also raised the possibility that fissures could be caused by tuberculosis or syphilis at that time .
Then in 1951, Eisenhammer  described the partial lateral internal sphincterotomy (LIS), though he combined this with a rather liberal dilation of the anal canal after the sphincterotomy. He is, I believe the first to list the number of patients treated by his method (181) and states that none had any defecation difficulties afterwards  Fig. 5.4.
a The ridge is an hypertrophied internal sphincter in a patient with fissure. b Isolated internal sphincter about to be divided in an LIS. c Completed LIS with an intact external sphincter at the base. Does it support the anal canal better here than in the poster mid line?
This procedure was enthusiastically adopted by surgeons around the world. It was also thought by others that incontinence was not an issue . The first publication to quantify continence disturbance was in 1985. It stated that, out of 306 patients who had had an LIS at least one year earlier, only 15 suffered from any degree of incontinence. This was principally to flatus. In no patient was it severe enough for the patient to wear a pad .
However in 1989 everything changed. Khubchandani published a large case series of follow-up after LIS, in which 36% of the patients were incontinent to flatus and 5% to solid stool . In 1996, from the University of Minnesota, which had reported such low incontinence rate in 1985  in a retrospective comparison of open versus closed LIS now found that 30.3% of their patients were incontinent to flatus and 11.8% to solid stool . The age of GTN (glyceryl trinitrate), Botox, and calcium channel blockers was born. In many countries it appears that LIS had been abandoned in favor of medical therapy . In a systematic review of anal incontinence following LIS, 22 studies, mostly nonrandomized case series or cohorts found an overall incontinence rate of 14% with less than 1% having incontinence to solid stool . Yet patient satisfaction with LIS has been reported to be high . The often crippling pain of fissure is almost immediately relieved. And the rest of us colorectal surgeons wondered: “Where are all these incontinent patients?”