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Minimal Invasive Procedure for simple Fistula in Ano ( D & C )

Minimal Invasive Procedure for Simple Fistula in ano

Dr. Shantikumar D. Chivate MS, FCPS, FICS, FAIS, FACRSI. Dr. Laxmikant D. Ladukar. MS, FICS, FACRSI Dr. Meghana V. Chougule M.D.  Jeevan Jyot Hospital, Opposite Shahu Market Naupada,THANE ( Maharashtra.)400602 This e-mail address is being protected from spambots. You need JavaScript enabled to view it This e-mail address is being protected from spambots. You need JavaScript enabled to view it www.drchivate.com



The study of 92 patients suffering from simple anal fistula which includes; straight, trans sphincteric, inter sphincteric fistulae were treated with new procedure.  The new procedure was under taken, to determine & compare the healing time and post operative pain & pain during dressings, recurrence and complications after procedure dilatation to curettage and lay open fistulatomy / fistulectomy.


During 2006 to 2010, 92 cases of simple fistula were treated by dilatation, curettage and suturing of internal opening; under regional anaesthesia.


Histology of Curetted material indicated 8 cases suffering from tuberculosis & 84 from inflammatory pathology from crypto glandular origin. Healing of 34 fistulae was noted in 7 days, 42 in 14 days and 8 in 21 days. Complete healing was achieved in 82 patients out of 84 (97.6 %) in 3 weeks. In two cases discharge continued. The minimum pain was suffered by the patients in the post operative period or during dressings. No deformity of anal canal or incontinence was noted. In 5 cases of fistula recurrence was noted after 6 months.  Over all out of 84 cases 7 cases (8.3 %) had recurrence. After operation patients were discharged in 48 hours after removal of pack.


Dilatation and curettage is less invasive, faster healing and nearly pain free procedure for simple fistula in ano. This is non touch technique to the sphincters & does not have potential danger of incontinence.

Key words:-Simple straight fistulae, dilatation & curettage, suturing of internal opening





Fistula in ano is an age old problem, notorious for its chronicity, recurrences and frequent acute exacerbations. Fistula-in-ano is one of the common but difficult surgical problems [1]. The classification of Parks is based on the location of fistula tract in relation to anal sphincter muscle; intersphincteric, transsphincteric, suprasphincteric, or extrasphincteric [2]. The term complex fistula is modification of the Park’s classification, in which the track crosses >30 to 50% of the external sphincter, anterior in females, multiple tracks, recurrent and horse fistulae. Due to the involvement of the anal sphincter, treatment of complex fistulae has potential high risk for impairment of continence [3, 4].

Nearly 91% of the fistulae are in the category of simple fistulae. The first surgical lay open of fistula in ano as practiced today was used by John of Arderne in 1337 [5].  Routinely treated by lay open & curette or excise & pack and 90 % fistulae heal. The variation in treatments have been tried to cure fistula in ano which include fistulectomy with primary closure / skin grafting [6, 7, 8]. Minor variations in classical operation of lay open have been added by Hanlay[9] .

It is very difficult to assess how much sphincter is involved and consider for lay open procedure in simple transsphicteric fistula.  The healing with fibrosis can cause distortion of anal sphincter, resulting in impairment of its function.

Due to the lack of a single appropriate technique for treatment of fistula-in-ano, it is selected by the surgeon’s experience and judgment. Every surgeon has to keep in mind the balance between the extent of sphincter division, postoperative healing rate, and functional loss [3]. Whatever the type and the extent of fistulae are, the principles of anal fistula surgery are to get rid of the fistula, prevent recurrence, and preserve sphincter function. Most of the fistula-in-ano has been conventionally treated by either fistulotomy, or fistulectomy, which have been proven to be effective [5].

The treatment of simple fistula remains simple but causes pain, long healing time and potential danger of incontinence. In planning of procedure minimum invasive has efforts to avoid wound, pain and minimizing healing duration and functional impairment of anal sphincters and save working days. Moreover, the need of prolonged hospitalization, extensive mutilation of anorectal region, pain during post operative period and during dressings, chances of recurrence and anal incontinence in some of the cases of simple fistula have encouraged us to try out a new indigenous minimum invasive treatment of fistula in ano.





During the period between; 2006 to 2010 at Jeevan Jyot hospital Thane; a tertiary center for fistula treatment, 92 selected cases of simple fistula were admitted, after careful examination and assessment. All cases were examined clinically, investigated for routine tests, proctoscopy, sigmoidoscopy & manometry. When patients were seen in the clinic, no effort was made to define the tract or investigate the condition by radiology. All patients were counseled about the method of treating the fistula and informed consent was taken. The procedure was discussed in hospital ethical committee and permission was granted for it.

The fistula particularly exclude from the study are:-

Complex Fistula,

High Fistula,

Horse shoe Fistula

Recurrent Fistula.

Anterion fistula in females

The cases suffering from pulmonary & gastrointestinal  tuberculosis and inflammatory bowel  disease were excluded from study.


In the operation room, the patients were evaluated in the lithotomy position under spinal anaestheia. The fistula was palpated from external to internal opening and around dentate line circumferentially and the rectum above it. An infant feeding tube No. 5 was introduced into external opening and 3 – 5 ml. of hydrogen peroxoid and was injected with gentle force. The internal opening was confirmed. A ureteric catheter No. 5 was negotiated from external opening to internal opening smoothly. Hegar dilators were introduced in ascending order up to No 6 dilator was passed. [Fig No 1] The external sphincter was palpated over the dilator. A small size sharp curette was passed from external to internal opening and tract was confirmed.  The index finger of left hand was introduced into the rectum and its tip was kept on internal opening. The curetting was started from internal opening to external one till fibrotic gritting sensation was felt and no more soft material on curette. The internal opening was curetted with guidance of tip of the index finger. The internal opening was sutured along with inclusion of internal sphincter muscle in the stitch. The fistula tract was packed with small tape of linen soaked with povidone-iodine. The curetted material was submitted for histology examination. The pack was removed after 48 hours. An infant feeding tube was passed in the tract & gentle syringing was done every day with diluted povidone iodine solution, till wound was healed. After healing patients were followed weekly for 4 weeks and monthly for 6 months. Later on yearly patients were communicated on telephone about their condition.


In the specialized colon & rectal unit, 92 patients of simple fistula-in-ano wer operated with dilatation and curettage, from January 2006 to December 2010; average age was 32.5 years ranging from 15 to 65 years. Out of 92 cases 68 were males and 24 were females. In the series out of 92 cases, 12 were diabetics.  In twenty- two patients did not have any prior history of perianal problem, while the 70 patients had past history of perianal abscess. The fistula tract was traced from external to internal opening. The internal opening was delineated in all the cases. Proctoscpy, sigmoidoscopy and manometry did not reveal any significant abnormality. Histology indicated in 84 cases were inflammatory originated from crypto glandular tissue and 8 patients were suffering from tuberculosis. The cases proved for tuberculosis were excluded from the follow up. Healing of 34 (40.4%) fistulae was noted in 7 days, 42 (50%) in 14 days and 8 (9.5%) more in 21 days. Complete healing was achieved in 76 patients out of 84 (90.4 %) in two weeks. In two cases discharge continued. The minimum pain was suffered by the patients in the post operative period or while doing dressings.

No deformity of anal canal or incontinence was noted. In 5 cases of fistula recurrence was noted after 6 months. Out of 84 cases 7 cases (8.3 %) had recurrence. All the patients were followed up for a minimum period of two year.


Out of all fistulae, there are 90 % classified as simple fistulae. They are simple in treatment and have good result in 90 % cases. They are defined as tracts without branching and close to anal verge. The simple fistulae are commonly treated by lay open techniques, fistulectomy, fistulotomy, excision and skin grafting. All these procedures require excision of tissue in anal & perianal sensitive region. The wounds are very painful and daily dressings are more painful. These wounds require daily packing. In dilatation and curettage the wound is hardly one centimeter in diameter and dressings are painless, done by syringing with infant feeding tube in the tract.

The healing period for fistulotmy in simple fistula is on average 20 days and for fistulectomy 25 days. In the series of dilatation & curettage healing of 34 fistulae was noted in 7 days, 42 in 14 days and in 8 cases 21 days. Most of the cases 76 out of 79 healed in 14 days. The patient with recurrent fistula requested to do same procedure for them.

The cure of simple fistula is simple & it is common phenomena.  The complications like incontinence & anal deformities cannot be ruled out. Lay-open of fistula is procedure involves cutting the fistula open and curette.[ 10 ] Once the fistula has been laid open it will be packed on a daily basis for a short period of time to ensure that the wound heals from the inside out. It leaves behind a scar, and depending on the position of the fistula in relation to the sphincter muscle, can cause functional impairment of anal canal.  All procedures are having potential danger of complications. In fistulectomy,  the chances of getting recurrence or incontinence or both cannot be ruled out in addition to wide removal of chunk of anal & perianal sensitive tissue up to the dentate line. The recurrent rate of “lay-open” fistulotomy is of 0%-8%. Minor and major incontinence is 34%-64% and 2%-26%, respectively [11. 12].

If the fistula is trans sphincteric 30 % of fistulae and it can pass through a significant portion of the sphincter muscle. It is very difficult asses how much portion is involved during clinical examination and examination under anaesthesia. Without anaesthesia probe cannot be passed and with anaesthesia muscle is not well felt. In this situation a cutting seton may be used. The seton is tightened over time, with a median of six times (3–15 times range) gradually cutting through the sphincter muscle and healing as it  goes, period required is around two / three months and it is painful. [13 ] In our series it was not mandatory to recognize and respect the trans sphincteric fistula for its complications.

Other alternative approaches are the application of fibrin glue and fistula plug. Since 1999, several studies on fibrin glue treatment of anal fistula have been published. The healing rate after debridement and fibrin glue injection is 14%-60% [14,15]. Continence may not be affected. Injection of fibrin glue for the treatment of perianal fistulas is safe, simple, and associated with early return to normal activity. Although moderately successful, it may preclude extensive surgery in more than one-half of these patients. [16]

Fistula plug, the latest technique for complex fistula-in-ano repair, has a reported failure rate of 13%. A success rate of 83% with a median follow-up of 12 months is reported for high cryptoglandular anal fistulas. In the systematic review published, the success rate of the Fistula Plug is 65-75% [17,18  ]

In our series, we found 0% incontinence and recurrence in 7 cases from84 patients treated by the procedure dilatation & curettage for simple fistulae including transsphincteric fistulae. The data on continence was determined by validated Wexner’s score in all the patients with complete follow up, which includes incontinence of faeces & flatus. All the procedures were done by a single surgeon. However, it is a single-arm study with no comparison group.


The life after treatment of piles or fistula is measurable. The painless conditions before operation are unbearable and painful after it. Fistula is common surgical problem, simple fistulae are 90 – 92 %; have 90 % success rate of treatment. The trans sphincteric fistulae are in this group which can be potentially dangerous to be treated by simple lay open method. They are treated without much significance and complications in dilatation & curettage. The lay open or ablation of fistula associated with excision of anal and perianal sensitive tissue gives excruciating pain and painful dressing. Wide wound requires prolong time for healing. In the minimal invasive dilatation and curettage heals faster, short hospital stay and painless dressings. All the patients are more comfortable & had less absentee from their work. The outcome of the procedure is comparable to open methods. There is no even potential danger of incontinence.




















1. C. Zanotti, C. Martinez-Puente, I. Pascual, M. Pascual, D. Herreros, and D. García-Olmo, “An assessment of the incidence of fistula-in-ano in four countries of the European Union,” International Journal of Colorectal Disease, vol. 22, no. 12, pp. 1459–1462, 2007.

2. A. G. Parks, P. H. Gordon, and J. D. Hardcastle, “A classification of fistula in ano,” British Journal of Surgery, vol. 63, no. 1, pp. 1–12, 1976.

3. I. J. Kodner, A. Mazor, E. I. Shemesh et al., “Endorectal advancement flap repair of rectovaginal and other complicated anorectal fistulas,” Surgery, vol. 114, no. 4, pp. 682–690, 1993.

4. N. Mizrahi, S. D. Wexner, O. Zmora et al., “Endorectal advancement flap: are there predictors of failure?” Diseases of the Colon and Rectum, vol. 45, no. 12, pp. 1616–1621, 2002.


5.Parks, A. G.: The pathogenesis and treatment of fistula in ano. Brit. Med. J., 1: 463-469, 1961.

6. Perez F, Arroyo A, Serrano P, Candela F, Perez MT, Calpena R, Prospective clinical and manometric study of fistulotomy with primary sphincter reconstruction in the management of recurrent complex fistula-in-ano. Int J Colorectal Dis 2005 Oct 20:1-5.



7. F. Seow-Choen and R. J. Nicholls, “Anal fistula,” British Journal of Surgery, vol. 79, no. 3, pp. 197–205, 1992. Khurana, C., Saronwala, K. C. and Gupta, S. P.: Primary skin grafting after fistulectomy in the treatment of fistula in ano. Amer. J. Proctol., 23: 139-152, 1972.

8. Hughes, E. S. R.: Primary skin grafting in proctological surgery. Brat. J. Surg., 41: 639-642, 1953.






Mandache, F., Prodescu. V., Constantinescu, S., Kover, G. and Stanciulescu, P.: The treatment of perineo-anal and perineoanorectal fistulae (long term results). Zbl. Chir., 87: 1884-1890, 1962.  

9.Hanley, P. H.: Conservative surgical correction of horse-shoe abscess and fistula. Dis. Colon Rec., 8: 364-368, 1965.

10. Garcia-Aguilar J, Belmonte C, Wong WD, Goldberg SM, Madoff RD. Anal fistula surgery : factors associated with recurrence and incontinence. Dis Colon Rectum 1996; 39 : 723-9.

11 Mandache, F., Prodescu. V., Constantinescu, S., Kover, G. and Stanciulescu, P.: The treatment of perineo-anal and perineoanorectal fistulae (long term results). Zbl. Chir., 87: 1884-1890, 1962.

12. Jackman, R. J.: Operation for anal fistula-some reasons for failure. Collected papers from the Mayo Clinic. Amer. J. Surg., 68: 323-325, 1945.

13    R. K. Pearl, J. R. Andrews, C. P. Orsay et al., “Role of the seton in the management of anorectal fistulas,” Diseases of the Colon and Rectum, vol. 36, no. 6, pp. 573–579, 1993.

14. R. Cirocchi, A. Santoro, S. Trastulli, et al., “Meta-analysis of fibrin glue versus surgery for treatment of fistula-in-ano,” Annali Italiani Di Chirurgia, vol. 81, no. 5, pp. 349–356, 2010.

15 Johnson EK, Gaw JU, Armstrong DN. Efficacy of anal fistula plug vs. fibrin glue in closure of anorectal fistulas. Dis Colon Rectum. Mar 2006;49(3):371-6.

16. Buchanan GN, Bartram CI, Phillips RK. Efficacy of fibrin sealant in the management of complex anal fistula: a prospective trial. Dis Colon Rectum. Sep 2003;46(9):1167-74.

17. Chung W, Kazemi P, Ko D, Sun C, Brown CJ, Raval M, et al. Anal fistula plug and fibrin glue versus conventional treatment in repair of complex anal fistulas. Am J Surg. May 2009;197(5):604-8.

18. Safar B, Jobanputra S, Sands D, Weiss EG, Nogueras JJ, Wexner SD. Anal fistula plug: initial experience and outcomes. Dis Colon Rectum. Feb 2009;52(2):248-52.

19. P. Meinero and L. Mori. Video-assisted anal fistula treatment (VAAFT): a novel sphincter-saving procedure for treating complex anal fistulas, Tech Coloproctol. 2011; 15(4): 417–422.

Figure No. 1


Black arrow internal opening. White arrow Hegar dilator