Management of fistula in ano.
Fistula in ano is an age old problem, involving the anorectal region. It is notorious for its chronicity, recurrences and frequent acute exacerbations. Hippocrates (460 B.C.) described the use of seton to cure fistula in ano. He also favoured use of knife if not cured by seton. The first surgical lay open of fistula in ano as practised today was performed by John of Arderne in 1337 (Quoted by Perrin). Various treatments have been tried to cure fistula in ano including fistulectomy with primary closure and fistulectomy with skin grafting., ,  Minor variations in classical operation of lay open have been added by Hanlay and Parks. The routine surgical treatment employed today is fistulectomy and fistulotomy., 
Thus, in principle the surgical. treatment of fistula in ano has remained the same without much improvement. Moreover, the need of prolonged hospitalization, extensive mutilation of anorectal region, chances of recurrence and anal incontinence in some of the cases of high level fistula have encouraged us to try out a new indigenous ambulatory treatment of fistula in ano.
Great Indian Surgeon Sushruta narrated in his teachings the use of Kshara for cure of fistula in ano. The work of Sushruta was later compiled as "Sushrut Samhita" in the 5th century A.D. (as quoted by Sharma,). Acharya Chakrapani Datta (10-11 Century A.D.) and Acharya Bhav Mishra (16-18 century A.D.) have described in their classical Ayurvedic texts, the method of preparation and treatment of fistula in ano by use of Kshara Sutra (K.S.)., 
Many studies have been published by Ayurvedic surgeons recently with encouraging results for treatment of fistula in ano by use of Kshara Sutra. ,,,
Drainage of fistula in ano by plain threads has also been advocated by Toupet, Mandache et al and Duhamel, with satisfactory results. The treatment used in the present study is by ligating the fistulous tract with K.S. (Caustic Ligature), described in the Ayurveda, the Indian system of medicine.
Preparation of Kshara Sutra
The materials used were cotton surgical thread No. 20, milk of Euphorbia neri-folic and powder of Rhizomes of Curcuma longa. The milk of Euphorbia neri-folic was collected in a clean receptacle by repeatedly incising the stem of the plant. Equal amounts of the milk of Euphorbia neri-folic and powder of dry Rhizomes of Curcuma Longa were thoroughly mixed together till a fine mixture was prepared. The cotton threads pre-cut in one meter length were now immersed in the mixture and left there for one to two hours. Then, these were taken out and dried in hot air oven. The impregnation of threads in the mixture was repeated seven times and Kshara Sutra thus prepared was sealed in glass tubes.
Selection of cues
Forty cases of fistula in ano were included in the present study. A detailed history of the patient was taken. Local examination was conducted noting carefully the number, site, distance, discharge, tenderness, induration and the positions of internal and external openings. Rectal and proctoscopic examination was also done in each case. Routine investigations like hemogram, urine, stool and skiagram chest were done in all cases.
Application of Kshara Sutra
All patients were advised a low residual diet, laxative and rectal wash before the application of K.S. Perineum was shaved and cleaned with soap and water. The patient was put in a lithotomy position and the perineum was prepared with antiseptic lotions. Adult cases were administered injection diazepam 10 mg intravenously and children were given general anesthesia. The findings of local examination were again confirmed and probing done to know the extent and direction of the fistulous tract. Depending on the site of fistula, the index finger of the right or the left hand was passed into the anal canal and a silver malleable probe was passed into the fistulous tract gradually and cautiously by the other hand, till it touched the finger in the anal canal. The tip of the probe was brought out of anus, by bending it. A suitable length of K.S. was cut and threaded through the eye of the probe [Fig. 1]. The probe was brought out of the anus leaving the K.S. in the fistulous tract. The K.S. was now moderately tightened and tied outside the anal verge over a small piece of gauze [Fig. 2], Two additional knots were applied to keep the tension created by the first knot in place. Sterile dry gauze dressing was applied.
A new piece of K.S. was replaced and tied on every 6th day in all the cases by rail road technique till the last K.S. gradually cut through the fistulous tract, leaving a small healing ulcer at the anal verge. No anesthesia was required for these changes. The length of K.S. taken out on each occasion was measured and recorded. Shortening of the thread removed at each change indicated the shortening of the fistulous tract. The ulcer at the end of the cut through also healed in about seven days time. All cases were kept ambulatory throughout the postoperative period. Oral analgesics were allowed in all cases and suitable antibiotic was administered in a few cases for 5 to 7 days, as they had significant discharge of pus.
All the cases were examined every month for the first 3 months and every 3rd month thereafter. Anal defects and recurrences if any were recorded. Total period of followup was 18 months.
Male patients were the usual sufferers (89.47%). Duration of the disease varied from 3 months to 3 years. Majority of the cases complained of pain, discharge and swelling in the perianal region. Twenty per cent fistulae were subcutaneous, 10% submucous, 45% intermuscular, 17.5% anorectal and 7.5% high level variety.
[Table 1] gives the details regarding the number of fistulae, average initial lengths, average durations of cut through (in days) average unit cutting time (i.e., the number of days required to reduce the length of K.S. by one centimeter), and average durations of treatment (in days) in various types of fistulas encountered in the present series. The Table is self-explanatory and needs no comments.
Ninety five per cent of the cases had complete cure while 5% had recurrence after treatment with K.S. The incontinence of feeces and flatus was not observed in any of the cases. The first application of K.S. was easy in majority of the cases but some had difficulty. But all cases had successful application of K.S. in the fistulous tract. Subsequent application of K.S. was painless in 85.0%.
The routine surgical treatment of fistula in ano is by laying open the tract either by fistulectomy or fistulotomy. Many modification have been added to these operations. It is a common observation that in inexperienced hands, incontinence of faeces or stricture of the anal canal are frequent in cases of high level fistula in ano. The high recurrence of fistula in ano is another common problem.
In the present study all the cases were ambulatory after initial application and subsequent changes of K.S. A few cases were confined to bed for a day or two because of pain. All the cases were treated on outpatient basis; but, a few patients had to be hospitalized as they had come from far off places. The unit cutting time in the present study was five days which is similar to that of Deshpande et al, ,,, i.e. 5 days,,, and 6 days.,  The duration of treatment in the present study when compared to conventional surgical treatment of fistula in ano was less in submucous, subcutaneous and intermuscular fistula. In cases of high level fistulae and anorectal fistula it was very much less than the reported duration by surgical treatment of fistula in ano.
Deshpande et al,,, have advocated application of K.S. without anesthesia. But it was observed during the present study that it was difficult to apply K.S. without sedation.
The results of treatment in the present study when compared to those of Deshpande et al,,, are almost similar. These authors have reported 96.5% and 96% cure rate, while in the present study it is 95.0%. The rate of recurrence after conventional treatment of fistula as reported by Bennet was 10 cases out of 118 and by Jackman it was 215 patients out of 500. In the present series it was only 5%. Deshpande el have reported a recurrence rate of 3.5% (7 cases out of 200) in a 2-9 years follow up.
The treatment of fistula in ano by K.S. is simple, easy and safe, The chances of recurrence are very much less in properly selected cases of pyogenic fistulae in ano excluding horse shoe fistulae. The treatment can also be employed to severaly ill patients of hypertension, diabetes and heart disease.
The suggested mode of action of K.S. is as follows:
1. The cut through of fistulous tract is effected by the pressure exerted on anorectal tissue by the moderately tight K.S. tied in the fistulous tract.
2. The presence of K.S. in the fistulous tract does not allow cavity to close down from either ends and there is a continuous drainage of pus along the K.S. itself.
3. The K.S. slowly and gradually cuts through the fistulous tract from apex to the periphery. There is an ideal simultaneous cutting and healing of the tract and no pocket of pus is allowed to stay back.
4. The Kshara (Caustics) applied on the thread are anti-inflammatory, antislough agents and in addition, have property of chemical curetting. The K.S. remains in direct contact of the tract and therefore, it chemically curettes out the tract and sloughs out the epithelial lining, thereby allowing the fistulous tract to collapse and heal. ,,
5. The K.S., due to its antibacterial property, does not allow bacteria to multiply in its presence.
6. The pH of K.S. was towards the alkaline side and therefore it did not allow rectal pathogens to invade the cavity.
We are thankful to the Principal, R.N.T. Medical College, Udaipur for allowing us to publish the Hospital records and to Dr. P. J. Deshpande, Professor and Head, Department of Shalya Shalakya, Institute of Medical Sciences, B.H.U. Varanasi-5, for his guidance during the present study.