Seton Drainage Research Articles

Experimental Model of Fistula-In-Ano

This study was designed to create and evaluate an experimental porcine model of fistula-in-ano. Initial cadaveric dissection enabled refinement of the technique for fistula formation and histoanatomical study of the porcine anal canal. Subsequently, three surgically created fistulas were treated by seton drainage in each of eight male pigs (weight, 38-41 kg). After 26 days, magnetic resonance imaging at 1.5 Tesla was performed and setons removed under general anesthesia, enabling clinical and microbiologic track assessment. Two pigs were killed for histologic fistula track assessment. Histoanatomical assessment noted a rudimentary internal anal sphincter, together with structures resembling anal glands. Artificial fistulas persisted during seton drainage and were more often associated with fecal than skin-derived organisms compared with both perineal and anal canal swabs (P = 0.002). All six fistulas assessed histologically had a lumen, and abundant surrounding granulation tissue similar to that seen in human fistula-in-ano. Epithelialization was not evident in any track. Fistulas were visualized as high signal tracks using magnetic resonance imaging. Porcine anal anatomy resembles that of humans, and an experimental model proved suitable when assessed by magnetic resonance imaging, microbiology, and histologically, which demonstrated abundant granulation tissue. This model could be further used to investigate fistula treatments.

Long-term Results of Seton Drainage on Complex Anal Fistulas in Patients with Crohn's Disease

Long-term Results of Seton Drainage on Complex Anal Fistulas in Patients with Crohn's Disease

Combined seton placement, infliximab infusion, and maintenance immunosuppressives improve healing rate in fistulizing anorectal Crohn's disease: a single center experience.

Infliximab (anti-TNF alpha) has been used for the treatment of fistulizing Crohn's disease with variable efficacy. The aim of this study was to evaluate the efficacy of infliximab combined with selective seton drainage in the healing of fistulizing anorectal Crohn's disease. This was a retrospective chart review of all patients with fistulizing Crohn's disease treated with infliximab between March 2000 and February 2002. Twenty-nine patients (12 male; mean age, 31 years) received a mean of 3 (range, 1-5) doses of infliximab 5 mg/kg. Twenty-one patients had perianal fistulas; eight had rectovaginal fistulas, four with combined rectovaginal/perianal fistula. Fourteen of 21 patients (67 percent) with perianal fistula had a complete response (mean follow-up, 9 months), 4 of the 14 relapsed (mean, 6 months), but all had a complete response to retreatment (mean, 9 months). A partial response occurred in four patients (19 percent), defined by decreased drainage (2 patients) or infliximab dependence (2 patients) requiring repeated dosing every six to eight weeks. Three patients (14 percent) had no response. Seton drainage was used before infusion in 13 perianal patients for perianal infection and 17 were treated with maintenance azathioprine or methotrexate. Of eight patients with rectovaginal fistula, complete response occurred in one, partial response in five, and no response in two. Two partial responders became infliximab dependent. A complete response was observed in one patient with isolated rectovaginal fistula, a partial response in five. No patient with a combined rectovaginal/perianal fistula had a complete response. Five rectovaginal fistula patients were taking maintenance immunosuppressive agents and two had seton drainage before infusion. Selective seton placement combined with infliximab infusion and maintenance immunosuppressives resulted in complete healing in 67 percent of Crohn's patients with perianal fistula and partial healing in 19 percent. Relapse was successfully treated with repeat infusion. Concomitant rectovaginal fistula was a poor prognostic indicator for successful infliximab therapy.

V-Y advancement flap for treatment of fistula-in-ano.

The management of high fistula-in-ano presents a difficult surgical challenge. Laying open of high transsphincteric, intersphincteric, and suprasphincteric fistulas is associated with incontinence. Mucosal advancement flap can be technically difficult and is associated with ectropion and incontinence. We report a new technique for the treatment of fistulas, which may eliminate these problems. Between 1997 and 2002, 18 patients (13 males), median age 46 (range, 25-64) years with high fistula-in-ano were treated. There were ten transsphincteric, four intersphincteric, and four suprasphincteric fistulas. In all patients, perianal sepsis was allowed to resolve completely with a drainage seton before definitive surgery. The surgical technique used involved core fistulectomy, curettage of any cavity, closure of the defect in the internal anal sphincter, and a V-Y advancement buttock flap to cover the internal opening, leaving the site of the external opening for drainage while preserving both internal and external sphincters. Outcome was assessed in terms of healing and continence. Most patients were discharged from the hospital within 48 hours. Median follow-up was 19 (range, 3-60) months. There were three patients who failed to heal. Of these, two underwent repeat surgery and healed. Two further patients had recurrent fistulas, both of whom continued with conservative treatment. Overall, 15 of 18 (83 percent) patients experienced healing of their fistula. Continence was preserved in all patients. This procedure is easy to perform, healing is rapid, and it appears to be effective in curing fistula-in-ano while preserving both external and internal anal sphincters.

Smoking affects the outcome of transanal mucosal advancement flap repair of trans-sphincteric fistulas.

The aim of the study was to identify variables affecting the outcome of transanal advancement flap repair (TAFR) for perianal fistulas of cryptoglandular origin. Between 1995 and 2000, a consecutive series of 105 patients (65 women, 40 men), with a median age of 44 (range 19-72) years was included in the study. The patients were recruited from the colorectal departments of two university medical centres. Patients with a rectovaginal fistula and those with a fistula due to Crohn's disease were excluded. The following variables were assessed: age, sex, number of previous attempts at repair, preoperative seton drainage, fistula type, presence of horseshoe extensions, location of the internal opening, postoperative drainage, body mass index and the number of cigarettes smoked per day. The results were analysed by means of multiple logistic regression. The median follow-up was 14 months. No differences were observed between the two centres. TAFR was successful in 72 patients (69 per cent). None of the variables affected the outcome of the procedure, except for smoking habit of the patient. In patients who smoked the observed healing rate was 60 per cent, whereas a rate of 79 per cent was found in patients who did not smoke. This difference was statistically significant (P = 0.037). Moreover, a significant correlation was observed between the number of cigarettes smoked per day and the healing rate (P = 0.003). Cigarette smoking affects the outcome of TAFR in patients with a cryptoglandular perianal fistula.

Outcomes of primary repair of anorectal and rectovaginal fistulas using the endorectal advancement flap.

The endorectal advancement flap is a surgical procedure used in the treatment of anorectal and rectovaginal fistulas. There is a wide range of success rates published in the literature. This study was undertaken to examine the success rate of primary endorectal advancement flap in our own institution. We attempted to identify factors that influence the rate of healing. A retrospective review was performed on 105 patients (43 males) who underwent their first endorectal advancement flap at our institution between January 1, 1994, and June 30, 1999. Ninety-nine patients were available for follow-up. Sixty-two patients had anorectal and 37 had rectovaginal fistulas. The causes of fistula included cryptoglandular (48 patients), Crohn's disease (44), obstetric injury (5), trauma (1), and other (1). The median follow-up was 17.1 (range, 0.4-66.9) months. The median age was 42 (range, 16-78) years. Recurrence was seen in 36 patients (36.4 percent); thus, the primary rate of healing was 63.6 percent. Factors that were associated with higher rates of success were increased age (P = 0.011), greater body surface area (P = 0.012), history of incision and drainage of a perianal abscess preceding advancement flap (P = 0.010), previous placement of a seton drain (P = 0.025), and short duration of fistula (P = 0.003). Factors that negatively influenced the healing rate of the flap were the diagnoses of Crohn's disease (P = 0.027) and rectovaginal fistula (P = 0.002). Length of hospitalization, discharge on oral antibiotics, and the presence of a diverting stoma did not influence the rate of healing. Prednisone was associated with a distinct trend toward failure, with none of the patients on high-dose prednisone (greater than 20 mg/day) having achieved long-term healing. No fistulas recurred after a period of 15 months. The endorectal advancement flap is an effective method of repair for both anorectal and rectovaginal fistulas, even though the success rate may not be as optimistic as in some other published studies. Patient selection is imperative, realizing that a higher rate of failure may be present in Crohn's disease and rectovaginal fistulas. Control of sepsis before endorectal advancement flap with drainage of a perianal abscess and/or seton placement, whenever possible, is indicated.

Long-term results of seton drainage on complex anal fistulae in patients with Crohn's disease.

The aim of this study was to assess the long-term (greater than 2 years) results of seton drainage on anal fistulae in patients with Crohn's disease. Between September 1990 and September 1999, 32 patients with Crohn's disease underwent seton drainage for complex anal fistulae. The median follow-up time in these patients was 62 months (range, 25-133 months). In 10 patients (31.3%), recurrent perineal abscesses occurred with inlying seton drainage, and these were drained by re-insertion of the seton. A Malecot catheter was also inserted in 8 patients with recurrence. The overall success rate of long-term seton usage was 87.5%. The subsequent associated procedure was simple seton removal ( n = 9), secondary core-out fistulectomy ( n = 7), or lay-open fistulotomy ( n = 4). Eleven patients still had the seton in place. Recurrence developed in 3 patients (33%) who underwent simple seton removal and in 2 patients (18.2%) who underwent the secondary core-out procedure or fistulotomy. At the last follow-up examination, continence had not changed in 28 (87.5%) of the 32 patients. No change in continence was experienced by 10 of the 11 patients who underwent secondary fistulotomy or the secondary core-out procedure. Long-term seton drainage for complex anal fistula in Crohn's disease is efficacious in both treating sepsis and preserving anal sphincter function. A relatively good result was achieved by the secondary core-out procedure or fistulotomy at the time of seton removal.

Image-guided surgery for anal fistula in a 0.5T interventional MRI unit.

To determine whether MR-guided anorectal surgery is feasible, and to develop techniques for MR-guided anal fistula surgery. Six patients with pilonidal sinus (PNS), and 21 with suspected anal fistulae were operated on in the GE Signa SPIO 0.5T interventional MRI unit. Procedures were performed with magnet-safe Lockhart-Mummery fistula probes. Preprocedural and intra-operative MRI (IOMRI) techniques were used to identify the extent of the fistula tracts and septic foci, and to ensure the adequacy of the surgical procedure. IOMRI demonstrated the PNS lesions and the adequacy of excision. Imaging failed to demonstrate a fistula in two patients, as confirmed by surgical examination. No images were obtained in one patient due to his size (weight in excess of 100 kg). In 18 patients a fistula tract or abscess was demonstrated and IOMRI was used to assess the adequacy of the surgical procedure. In three patients this demonstrated incomplete drainage of septic foci, which was not obvious on inspection of the surgical field. We believe that in these patients IOMRI prevented an incomplete procedure and the potential requirement for a second operation. Further surgery was performed to rectify this situation. The fistula tract was laid open in 13 patients, and a Seton drain was inserted in five. MRI-guided surgery for anal fistula is feasible. IOMRI demonstrates the exact anatomy of the tracts and abscesses, and confirms that all have been adequately treated. We believe it may become particularly useful in surgery for recurrent and complex anal fistulae, and may lead to fewer recurrences.

Simultaneous anus and bowel operation is preferable for anal fistula in Crohn's disease.

Anal fistula in Crohn's disease is reportedly intractable, and little is known about factors influencing the outcome of surgery. The purpose of this study was to clarify the current status of surgery for anal fistula in Crohn's disease, and possible factors influencing surgical outcome were investigated. From August 1993 to September 1998, 39 of 239 Crohn's disease patients underwent long-term seton drainage. The patients were divided into two groups: patients who received simultaneous bowel and anus operation (simultaneous group; n = 11) and a control group ( n = 28). Twenty-nine of the 39 (74%) patients received two seton drains or more, with a mean of 2.7. Twenty-one (54%) patients received two or more operations. The rate of seton drain removal was 52% at 12 months after operation and 86% at 24 months. The cumulative rate of seton drains remaining at 12 months after the first operation was 10% in the simultaneous group and 37.7% in the control group, with a significant difference ( P = 0.038). Multivariate analysis revealed that simultaneous operation was the only significant factor that influenced the surgical results ( P = 0.0489). Seven of the 21 (33%) patients recurred after total removal of seton drain(s). All the patients who had recurrence belonged to the control group. Continence did not deteriorate after seton drainage. Ten patients (26%) required enterostomy and no patient received proctectomy. Healing of Crohn's anal fistula was significantly better in the simultaneous group than in the control group, and the recurrence rate was lower in the simultaneous group. Seton drainage for anal fistula in Crohn's disease was effective and preserved sphincter function.

The outcome of surgery for complex anal fistula.

OBJECTIVE: The aim of this study was to examine the results of surgery for complex anal fistulas treated by a variety of techniques, in terms of fistula healing, recurrent anal sepsis and effect of surgery on anal continence. PATIENTS AND METHODS: This study included 63 patients with complex fistulas treated between November 1995 and September 1999. A variety of techniques were employed, including short-term loose seton drain (12), long-term loose seton drain (11), cutting seton (17), and rectal advancement flap (19). Outcome was assessed at clinic review and continence was further assessed by detailed questionnaire sent to the patients sometime after surgery. RESULTS: Healing occurred in 9 (75%) patients treated with a short-term, loose drainage seton; 16 (94%) patients treated with a cutting seton and 17 (89%) patients in the rectal advancement flap group. Incontinence reported at clinic review seemed to be more frequent in the advancement flap group. However, a detailed continence questionnaire revealed that 50% of patients reported episodes of incontinence to flatus or liquid after all techniques, which had not been detected at routine clinical review. Incontinence to solids was only reported by two of the patients who had been treated with a cutting seton. CONCLUSIONS: Complex fistulas may be successfully treated by a variety of techniques. Disturbed anal continence following surgery is common and worse than clinic assessment would suggest.

Tube loop (seton) drainage treatment of recurrent extrasphincteric perianal fistulae

Tube loop seton drainage treatment of multiply recurring high-spreading extrasphincteric perianal fistulae in 19 patients is reported in this study. The drainage loop setons make possible the rinsing of the wound following fistulectomy and also the bidirectional drainage of the wound discharge. Strangulation of the wound and an early closure of the fistula and hence the development of recurrence is prevented by means of controlled formation of scarred tissue. The sphincteral musculature of the anus is also protected from damage. Thirty-five recurring fistulae of 19 patients included in the present study were treated successfully by this method. Two fistula recurred. None of these patients developed incontinence. The use of tube loop setons was found to have advantages over the pull-out method in cases of high-spreading multiply recurring extrasphincteric or suprasphincteric perianal fistulae.

Recto-vaginal fistulas in Crohn's patients can be successfully managed by aggressive systemic treatment and advancement flaps

• Introduction: Recto-vaginal fistulas are a dreadful complication of Crohn's disease for which no consensus exists regarding optimal treatment. The aim of the study was to identify possible medical and surgical variables that may determine outcome. Patients and Methods: 43 patients with a symptomatic recto-vaginal fistula, 33 with Crohn's disease (mean age: 35.7 yrs) and 10 without (mean age: 38.5 yrs) were studied retrospectively. All patients were initially treated with a seton drainage. Fistula surgery included vaginal advancement flaps (n=18), rectal advancement flaps (n=9) and sphincter repairs (n=6). Variables that were studied included: presence of Crohn's disease, proctitis, azathioprine treatment, vaginal vs rectal advancement flap and fecal diversion. Results: The recto-vaginal fistula was successfully closed in the non-Crohn and Crohn patients in 90% (mean follow-up: 21.2 mths) and 72.2% (mean follow-up: 31.5 mths) resp. (NS). Aggravation of incontinence was reported in none of the patients. Crohn patients treated with azathioprine for proctitis showed a higher success rate of fistula surgery, 84% as compared to the patients who didn't receive azathioprine, 57% (p=0.1). In Crohn's patients recurrence rates following rectal and vaginal flaps were comparable, 33.3% and 27.7%, resp. Success rate of fistula surgery was higher in Crohn's patients with fecal diversion, 90% as compared to those treated with medical colostomy, 61.9% (p=0.1). In conclusion: The majority of recto-vaginal fistulas in Crohn's patients can successfully be managed with systemic treatment and a subsequent advancement flap. Treatment with azathioprine and fecal diversion, but not the initial presence of proctitis or the type of advancement flap seem to influence outcome.

Perianal abscess in Crohn's disease.

Perianal disease is frequent in patients with Crohn's disease, and many of these patients will eventually have abscess formation. In a prospective follow-up study, we evaluated factors influencing the occurrence and recurrence of perianal abscesses. Of 126 consecutive patients with perianal Crohn's disease seen regularly in an outpatient clinic, 61 (48.4 percent) had at least one perianal abscess (mean follow-up, 32 +/- 17 months). In all, 110 episodes of an abscess with 145 anatomically distinct abscesses were documented. The occurrence of first abscesses was dependent on the type of anal fistula (ischiorectal, 73 percent; transsphincteric, 50 percent; superficial, 25 percent; P < 0.02). Surgical therapy consisted of seton drainage (34 percent), mushroom catheter drainage (49 percent), or incision and drainage (29 percent) and led to inactivation in all patients. Cumulative two-year recurrence rates after the first and second abscess were 54 and 62 percent, respectively. Abscess recurrence was less frequent in patients with a stoma (13 vs. 60 percent in patients without stoma after two years) and in patients with superficial anal fistulas (0 vs. 55 percent/56 percent in patients with transsphincteric/ischiorectal fistulas). Only two abscesses recurred within one year after removal of seton drainage, whereas 13 abscesses recurred with the seton still in place. Neither intestinal nor rectal activity of Crohn's disease significantly influenced the occurrence of an abscess. During the study period, only two patients developed partial stool incontinence. Development of perianal abscesses in Crohn's disease depends on the fecal stream and the anatomic type of anal fistula. Seton and catheter drainage are safe and highly effective in treatment. Long-term use of setons to prevent recurrent abscesses is not supported by our data.

Treatment of recurrent high anal fistula by total excision and primary sphincter reconstruction.

Fourteen patients with recurrent high anal fistula were treated by total excision of the fistulous tract with primary sphincter reconstruction. Nine patients with sepsis had seton drainage for one to three months before the operation. The surgical approach was the transsphincteric technique described by Mason. No covering stoma was used routinely, but three patients referred with a colostomy had the stoma closed 3 to 5 months later. After a follow-up from 1 to 4 years two patients had recurrence, which in one necessitated a diverting ileostomy. Three patients, one with recurrence and two without, suffered from minor anal incontinence. It is concluded that total excision with primary sphincter reconstruction is a treatment modality which should be considered for recurrent high anal fistula, especially in patients where closure by an advancement flap is not possible.

Seton treatment for perianal Crohn's fistulas.

In this study, we evaluated the efficacy of long-term seton drainage in the management of 13 patients with severe perianal Crohn's fistulas which had proven to be intractable to conventional therapy. After adequate curettage of the fistulous tracts and infected tissue, either a Penrose drain or a fine polyethylene catheter was inserted to encircle the tracts and tied. Patients were followed up for a mean period of 12.1 months. Perianal pain disappeared or improved in all 13 patients, while the body temperature of all 7 with pyrexia dropped to within the normal range. Discharge disappeared or diminished in 77% (10/13) and tenderness disappeared or improved in 77% (10/13). Induration disappeared or improved in 69% (9/13). Overall, good results were achieved in 10 patients, although 3 required redrainage. In one of these patients, a good result was achieved after colostomy was performed for active intestinal disease. Nevertheless, 2 patients did not improve, one of whom required lay-open surgery after seton treatment. In 8 of the 13 patients, some seton drains were able to be removed, and none of the patients experienced any soiling or leakage. Thus, we conclude that seton treatment is worthwhile in the management of perianal Crohn's fistulas as it alleviates the symptoms and simplifies multiple tracts. Moreover, it preserves sphincter function, is less invasive, and can be managed easily.

Glaucoma after penetrating keratoplasty.

Glaucoma after penetrating keratoplasty remains a management problem. The incidence is significant because of the status of those eyes undergoing PKP. Many have had multiple previous surgeries, and aqueous outflow may be compromised before the PKP. The surgery itself causes additional damage to the angle, often inducing peripheral anterior synechiae formation, with further impediment to aqueous outflow. Control of postkeratoplasty glaucoma is complicated by the need to preserve graft clarity for visual function. Medical treatment with aqueous suppressants is the first line of care. Since the introduction of apraclonidine 0.5%, and with topical carbonic anhydrase inhibitors soon to be introduced, perhaps medical management will become easier. When medical management fails, if the angle is open and viable, argon laser trabeculoplasty may be an option. If further intervention is indicated, the authors recommend a drainage seton (double-plate Molteno, or Baerveldt tube) in those eyes with good visual potential. For those eyes with poor visual potential (or those patients who cannot undergo surgery), we recommend contact Nd: YAG CPC.

Fistula-in-Ano in Crohn's disease

The outcome of aggressive surgical treatment of 64 symptomatic anal fistulas in 55 patients with Crohn's disease has been studied. Forty-one fistulas, in 33 patients, were treated by conventional fistulotomy (17 subcutaneous, 19 intersphincteric, 5 low transsphincteric fistulas). Thirty wounds (73 percent) healed within 3 months and eight more wounds (93 percent) healed within 6 months. Three wounds did not heal within 12–18 months. Two of these patients subsequently required proctocolectomy. Wound healing was not influenced by the presence of rectal Crohn's disease or granulomatous inflammation in the tract. No change in continence was experienced by 26 of the 33 patients who underwent fistulotomy. Three patients required proctocolectomy and the remaining four patients experienced minor degrees of incontinence postoperatively. Sixteen high transsphincteric, five suprasphincteric, and one extrasphincteric fistula in 22 patients were treated by laying open external tracts and placing a noncutting seton through the sphincter, which was left in place for prolonged periods to maintain drainage. During follow-up (6 months to 10 years, median 2.5 years), three fistulas healed and seven remained quiescent. Nine patients required further treatment by a new seton and three patients required proctocolectomy. Eight of the 22 patients who had a seton inserted had no change in continence, and six patients in this group developed minor changes in continence, mostly related to diarrhea associated with intestinal disease. Anal fistulas in Crohn's disease, which involve minimal sphincter muscle, can be successfully treated by fistulotomy. High fistulas should be treated with seton drainage to limit recurrent suppuration and preserve sphincter function.

Fistula-in-ano in Crohn's disease

The outcome of aggressive surgical treatment of 64 symptomatic anal fistulas in 55 patients with Crohn's disease has been studied. Forty-one fistulas, in 33 patients, were treated by conventional fistulotomy (17 subcutaneous, 19 intersphincteric, 5 low transsphincteric fistulas). Thirty wounds (73 percent) healed within 3 months and eight more wounds (93 percent) healed within 6 months. Three wounds did not heal within 12-18 months. Two of these patients subsequently required proctocolectomy. Wound healing was not influenced by the presence of rectal Crohn's disease or granulomatous inflammation in the tract. No change in continence was experienced by 26 of the 33 patients who underwent fistulotomy. Three patients required proctocolectomy and the remaining four patients experienced minor degrees of incontinence postoperatively. Sixteen high transsphincteric, five suprasphincteric, and one extrasphincteric fistula in 22 patients were treated by laying open external tracts and placing a noncutting seton through the sphincter, which was left in place for prolonged periods to maintain drainage. During follow-up (6 months to 10 years, median 2.5 years), three fistulas healed and seven remained quiescent. Nine patients required further treatment by a new seton and three patients required proctocolectomy. Eight of the 22 patients who had a seton inserted had no change in continence, and six patients in this group developed minor changes in continence, mostly related to diarrhea associated with intestinal disease. Anal fistulas in Crohn's disease, which involve minimal sphincter muscle, can be successfully treated by fistulotomy. High fistulas should be treated with seton drainage to limit recurrent suppuration and preserve sphincter function.