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Year : 2018  |  Volume : 31  |  Issue : 3  |  Page : 867-870

Cutting seton in management of complex perianal fistula – is it a safe procedure?

Department of Colorectal Surgery, Damanhur Medical National Institute, El Behera, Damanhur, Egypt

Date of Submission13-Sep-2017
Date of Acceptance09-Sep-2017
Date of Web Publication31-Dec-2018

Correspondence Address:
El Mohamady M Saeed
Department of Surgery, Damanhur Medical National Institute, Damanhour, Behira 22516
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/mmj.mmj_615_17

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The aim of this study was to evaluate the effectiveness, frequency of incontinence, and recurrence after treatment of complex perianal fistula with cutting seton.
Cutting seton commonly is prescribed for complex perianal fistula, because it is simple and cheap, but high incontinence rates suggest that cutting seton can damage continence musculature.
Patients and methods
A study was carried out in Damanhur Medical National Institute Colorectal Unit from October 2013 to October 2016 and included 30 patients with complex anal fistula. Patients were treated with cutting silk seton. Patients were followed-up for tightening or change of seton and for observing complications like incontinence and recurrence.
There were 24 male and six female. Mean age was 38 years. There were 14 high intersphincteric, 12 trans-sphincteric, and four suprasphincteric fistulas. Time taken for seton to cut through the fistulous tract varied from 4 to 10 weeks. Fistulas completely healed in 90% of the patients in 12 weeks. Recurrence of fistula developed in 10% of patients during the follow-up period. A total of six patients experienced minor incontinence, with two from each type of fistula in the study. Incontinence was to flatus in two patients and to liquid stool in four patients. There were no incidents of solid stool incontinence.
Use of cutting seton in treatment of complex perianal fistula is simple and cheap. This commonly used technique can damage continence musculature. Other techniques that do not cut the sphincter, when available, should be performed for higher fistula and anterior fistula in female.

Keywords: anal fistula, fecal incontinence, rectal fistula, seton, wound healing

How to cite this article:
Saeed EM. Cutting seton in management of complex perianal fistula – is it a safe procedure?. Menoufia Med J 2018;31:867-70

How to cite this URL:
Saeed EM. Cutting seton in management of complex perianal fistula – is it a safe procedure?. Menoufia Med J [serial online] 2018 [cited 2020 Feb 28];31:867-70. Available from: http://www.mmj.eg.net/text.asp?2018/31/3/867/248758

  Introduction Top

Fistula-in-ano is a hallow track lined with granulation tissue connecting a primary opening inside the anal canal to secondary opening in the perianal skin[1]. The etiology includes idiopathic and fistulas secondary to specific conditions like Crohn's disease, tuberculosis, and malignancy[2],[3]. There are many different classifications. The most well-known classification is Park's classification[2], which divides fistula into four groups, i.e., intersphincteric, transsphincteric, suprasphincteric, and extrasphincteric, based on the relation between the tract and anal sphincter[1],[2],[3]. Fistula-in-ano can also be classified as simple and complex. Simple fistulas include those that involve the submucosa only, such as low intersphincteric and low transsphincteric fistulas. In complex fistulas, there might be significant involvement of the anal sphincter muscle complex of more than 30–50% of the anal sphincter, and fistulas contain multiple fistula tracts. Horseshoe posterior fistula and anterior fistulas in a female patient were considered complex[2],[3].

The most frequent presenting complaints of patients with an anal fistula are swelling, pain, and discharge. Patients usually provide a reliable history of spontaneous or planned surgical drainage of anorectal abscess[4]. However, the identification of tract especially in complex fistulas required a combination of careful clinical examination and radiological assessment by either hydrogen peroxide-enhanced end-rectal ultrasound or MRI[5],[6],[7].

Success of surgery is usually determined by identification of the primary opening and dividing the least amount of muscle as possible. Continence-related morbidity has plagued physicians throughout history, a fact that is evidenced even in antiquity by the use of horsehair setons described by Hippocrates in his writings[1].

Although most surgeons were reluctant on the division of the external anal sphincter, division of the internal sphincter was practiced routinely during treatment of a perianal fistula until colorectal surgeons highlighted the risks associated with this practice; they reported 50–53% incidence of fecal incontinence after surgery for intersphincteric and transsphincteric fistulas[8].

Simple low fistula-in-ano is treated with laying open technique; on the contrary, various surgical techniques have been described to treat complex high fistula. These include seton technique, advancement flap procedure, intersphincteric ligation of perianal fistula tract, fibrin glues, stem cell, fibrin plug, and video-assisted anal fistula treatment[7],[8],[9],[10],[11],[12],[13].

Setons are commonly prescribed for high or complex fistula. The seton can be a tied cutting seton or loose seton, and the fistulotomy is performed as a second procedure[7]. The function of the seton is to provide drainage, to induce chronic fibrosis, and to cut the fistulous tract with preservation of sphincter function[7]. The purpose of this study was to evaluate the effectiveness of cutting seton in the treatment of complex perianal fistulas.

  Patients and Methods Top

This prospective study was conducted in colorectal unit in Damanhur Medical National Institute from October 2013 to October 2016. A total of 30 patients, with 24 male and six female, presenting with complex fistula-in-ano of cryptoglandular origin were included in the study. All patients did not have had fecal incontinence before the operation. Perianal area was inspected, which revealed the external opening. A digital rectal examination identified the internal opening. In few doubtful cases, we advised MRI. A rectal wash was done 24 h before the surgery.

The procedure was carried out under spinal anesthesia in lithotomy position. Before proceeding for surgery, hydrogen peroxide was injected through the external opening to localize the internal opening.

Probe was introduced through the external opening and the fistulous tract cored up to the external sphincter, and curettage was performed. The tip of the probe was then introduced through the remaining tract and brought out through the internal opening and anus. Suitable length of nonabsorbable suture was introduced through the probe and other end brought out of the anus. Both ends of the suture were tightened and dressing applied. The patient was discharged on the second postoperative day and advised to pull on the seton daily as tolerated. Repeated examinations were carried out at 1–2 weeks interval.

At each visit, the position of seton was assessed. The seton gradually cut through the fistulous tract within 4–10 weeks. The patients were followed-up for 6 months to see the wound healing and development of any complications such as recurrence or incontinence.

Ethical issue

The procedure followed in the study is in accordance with ethical committee of Damanhur Medical National Institute, and written consents were taken from the patients' guardians.

Statistical analysis

Data were fed to the computer and analyzed using IBM SPSS software package version 20.0for windows (SPSS Inc., Chicago, Illinois, USA) and MedCalc 13 for windows (MedCalc Software BVBA, Ostend, Belgium). Qualitative data were described using number and percentage. The Kolmogorov–Smirnov test was used to verify the normality of distribution. Quantitative data were described using range (minimum and maximum), mean, SD, and median. Significance of the obtained results was judged at the 5% level. All these tests were used as tests of significance at P less than 0.05.

  Results Top

Among the 30 patients, there were 24 (80%) men and six (20%) women. The age range was from 23 to 55 years; with a mean of 38 years [Table 1].
Table 1: Demographic data of patients

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There were 14 high intersphincteric, 12 trans-sphincteric, and four suprasphincteric types. Some patients experienced pain owing to the presence of the seton, which was relieved with analgesic. The time taken for the seton to cut through the fistulous tract varied from 5 to 8 weeks.

In 10 patients, the wound healing was complete in 8 weeks, whereas in 14 patients in the 10th week. In the remaining six patients, healing took place till the 12th week in three of them, whereas in the other three, no complete healing occurred at all and was considered as recurrence [Table 2].
Table 2: Wound healing time

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One patient re-presented with an abscess that required incision and drainage, but no further treatment of the fistula was required. Of the three fistulas that recurred, two patients required further treatment with a seton, and fistulas healed completely. On this occasion, one patient required lay-open of the submucous tract, which healed subsequently. Only six (20%) patients were noted with continence disorders, including gas incontinence in two (6.7%) patients and liquid stool incontinence in four (13.3%) patients. Of them, four fully recovered within 8 weeks of complete perineal wound healing. There were no incidents of solid stool incontinence [Table 3].
Table 3: Complications of cutting seton

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  Discussion Top

Hippocrates in 400 BC described fistulotomy using a cutting seton made of horsehair wrapped with lint threads. More than 2000 years later, the debate surrounding the various treatment options of perianal fistula is far from over, and the optimal treatment method is yet to be found[1]. The age distribution, maximum incidence, and male predominance seen in this series are similar to most other series[14],[15],[16],[17]. The cutting seton is used to slowly cut through the tissue and allow healing from inside to outside, thus minimizing the risk of incontinence[17],[18],[19]. The cutting seton requires further follow-up visits to achieve the desired effect. In our series, eight cases needed change of seton to achieve the desired effect.

The time for a fistula to heal with this method ranged from 2 to 3 months[20],[21]. The mean healing time in this study was 50 days which is comparable with other studies[14],[20],[21]. Only three (10%) of our patients had recurrence, a finding which correlated well with other studies such as McCourtney and Finlay[22] who reported only 4% recurrence, whereas Lykke et al.[23] in their study reported 12% recurrence. Kamrava et al.[24] reported 9% recurrence. Yet, there are studies that have reported no recurrence, such as Gurer et al.[16].

Incontinence is another aspect of the outcome after using cutting seton for treating complex fistula-in-ano. In literature studies, the range of incontinence is from 0 to 67%, with average rate of 12%. There was no relation between it and the frequency of tightening or type of seton[23],[24],[25]. Incontinence rates after treatment of transsphincteric, suprasphincteric, and extrasphincteric were 20.5, 67, and 37%, respectively[25]. In our study, six patients (four male and two female) with anterior fistula (20%) experienced incontinence, with two from each type of fistula (intersphincteric, trans-sphincteric, suprasphincteric representing 14.2 16.7, 50%, respectively). The incontinence was to flatus in two patients and for liquid stool (soling) in four patients. There were no incidents of solid stool incontinence. Incontinence after cutting seton was mostly for liquid stool followed by incontinence to flatus[13],[14],[15],[25]. The two patients with transsphincteric fistula and were complaining of incontinence to liquid stool recovered fully within 8 weeks of perianal wound healing. The other two cases were female and have not fully recovered until now. Incontinence rates were lower for cutting seton treatment of transsphincteric than suprasphincteric fistulas, 16.7 versus 50%, and lowest rate of incontinence was in intersphincteric type. The rates of incontinence increase with high level of tract, as reported by most of the previous studies[24],[25],[26].

  Conclusion Top

The use of cutting seton in the treatment of complex anal fistula is simple and cheap. The patient's tolerance of the procedure is well, but the high incontinence rates suggest that cutting setons can damage continence musculature. Other techniques that do not damage continence musculature, when available, should be performed especially in female.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

Malik AI, Nelson RL. Surgical management of anal fistulae: a systematic review. Colorectal Dis 2008; 10:420–430.  Back to cited text no. 1
Parks AG, Gordon PH, Hdcastle AD. A classification of fistula-in-ano. Br J Surg 1976; 63:1–12.  Back to cited text no. 2
Sheriff S, Steven DW. Idiopathic fistula-in-ano. World J Gastroenterol 2011; 17:3277–3285.  Back to cited text no. 3
Aman Z, Naeem M, Ahmad S, Aslam R, Ahmed T, Shamsi H. The effect of seton cut through technique on continence and recurrence after treatment of high fistula-in-ano. JPMI 2009; 23:251–253.  Back to cited text no. 4
Halligan S, Stoker J. Imaging of fistula in ano. Radiology 2006; 239:18–33.  Back to cited text no. 5
Cheong DM, Nougeras M. Anal endosonography for recurrent anal fistulas: image enhancement with hydrogen peroxide. Dis Colon Rectum 1993; 36:1158–1160.  Back to cited text no. 6
Theerrapol A. Routine use of setones for treatment of anal fistula. Singapore Med J 2002; 43:305–307.  Back to cited text no. 7
Sheikh P, Baakza A. Management of fistula-in-ano-the current evidence. Indian J Surg 2014; 76:482–486.  Back to cited text no. 8
The Surgisis. AFP anal fistula plug: report of a consensus conference. Colorectal Dis 2008; 10:17–20.  Back to cited text no. 9
Dixon M, Root J, Grant S, Stamos MJ. Endorectal flap advancement repair is an effective treatment for selected patients with anorectal fistulas. Am Surg 2004; 70:925–927.  Back to cited text no. 10
Sirikurnpiboon S, Awapittaya B, Jivapaisarnpong P. Ligation of intersphincteric fistula tract and its modification: results from treatment of complex fistula. World J Gastrointest Surg 2013; 5:123–128.  Back to cited text no. 11
Garcia D, Herreros D, Pascual I, Pascual JA, Del-Valle E, Zorrilla J, et al. Expanded adipose-derived stem cells for the treatment of complex perianal fistula: a phase II clinical trial. Dis Colon Rectum 2009; 52:79–86.  Back to cited text no. 12
Meinero P, Mari L. Video-assisted anal fistula [VAAFT]: a novel procedure for treating complex anal fistula. Tech Coloproctol 2011; 15:417–422.  Back to cited text no. 13
Pearl RK. Andrews JR, Orsay CP, Weisman RI, Prasad ML, Nelson RL, et al. Role of the seton in the management of anorectal fistulas. Dis Colon Rectum 1993; 36:573–577.  Back to cited text no. 14
Chuang WC, Chang CW, Tsai YL, Chun-Che F, Shu-Wen J. The cutting setones for complex anal fistulas. Surgeon 2008; 6:185–188.  Back to cited text no. 15
Gurer A, Ozlem N, Gokakin AK, Ozdogan M, Kulacoglu H, Aydin R. A novel material in seton treatment of fistula-in-ano. Am J Surg 2007; 193:794–796.  Back to cited text no. 16
Tozer P, Sala S, Cianci V, Kalmar K, Atkin GK, Rahbour G, et al. Fistulotomy in the tertiary setting can achieve high rates of fistula cure with an acceptable risk of deterioration in continence. J Gastrointest Surg 2013; 17:1960–1965.  Back to cited text no. 17
Visscher AP, Schuur D, Roos R, van der Mijnsbrugge GJ, Meijerink WJ, Felt-Bersma RJ. Long-term follow-up after surgery for simple and complex cryptoglandular fistulas: fecal incontinence and impact on quality of life. Dis Colon Rectum 2015; 58:533–539.  Back to cited text no. 18
Vial LM, Pares D, Pera M, Grande L. Faecal incontinence after seton treatment of anal fistula with or without surgical division of internal anal sphincter. Colorectal Dis 2010; 12:172–175.  Back to cited text no. 19
Hamalainen KP, Sainia AP. Cutting seton for anal fistulas: high risk of minor control defects. Dis Colon Rectum 1997; 40:1443–1446.  Back to cited text no. 20
Raslan SM, Aladwani M, Alsanea N. Evaluation of the cutting seton as a method of treatment for perianal fistula. Ann Saudi Med 2016; 36:210–215.  Back to cited text no. 21
Mc Courtney JS, Finlay IG. Cutting seton without preliminary internal sphincterotomy in managenment of complex high fistula in ano. Dis Colon Rectum 1996; 39:55–58.  Back to cited text no. 22
Lykke A, Stendahl J, Wille PA. Treating high anal fistula with slow cutting. Ugeskr Laeger 2010; 172:516–519.  Back to cited text no. 23
Kamrava A, Collins JC. A decade of selective use of adjustable cutting seton combined with fistulotomy for anal fistula. Am Surg 2011; 77:1377–1380.  Back to cited text no. 24
Ritchie RD, Sackur JM, Hodol JP. Incontinence rates after cutting Seton treatment of anal fistula. Colorectal Dis 2009; 11:564–571.  Back to cited text no. 25
Vial M, Pares D, Pera M, Grande L. Faecal incontinence after seton treatment for anal fistulae with and without surgical division of internal anal sphincter: a systematic review. Colorectal Dis 2010; 12:172–178.  Back to cited text no. 26


  [Table 1], [Table 2], [Table 3]


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