Introduction

Anal fistulae present a significant challenge to surgeons and patients. While low transsphincteric fistulae are well-addressed by fistulotomy (i.e., lay-open technique) with minimal change in long-term bowel habits,1 , 2 fistulae which involve more than 30 % of the internal sphincter carry a substantial risk of fecal incontinence with this approach.3 , 4 The tried-and-true placement of a draining seton carries no morbidity with regards to continence and can be instrumental in decreasing local sepsis. However, setons may cause patient discomfort, both from irritation and from persistent drainage. The need to achieve definitive control of the local sepsis, maintain fecal continence, and optimize patient quality of life has driven many surgeons to explore sphincter-sparing alternatives for fistula management.

The ligation of intersphincteric fistula tract (LIFT) was first described by Rojanasakul and colleagues in 2007.5 Since then, this technique has become popular among providers due to its simple technical elements, particularly when compared to anorectal advancement flaps, and favorable success rate. Among the many studies published in the literature, the success rate after LIFT ranges from 40 to 95 %, with a recurrence rate of 6–28 % (see Table 1).3 , 5 – 28 In comparison, success after advancement flap ranges from 60 to 94 %, while primary fistulotomy has been shown in some groups to have success rates over 90 %.29 – 31

Table 1 Selected LIFT studies
Full size table

In our practice, we use the LIFT procedure in patients with high or low transsphincteric fistulae in the absence of underlying inflammatory bowel disease. Patients with prior fistula operations, including failed prior LIFT or advancement flaps, recurrent fistulae, and complex fistulae characterized by multiple tracts, remain candidates for this procedure. In complex cases, an MRI of the pelvis or endorectal ultrasound may help identify the location and course of the fistula tract(s). We routinely place a draining seton 6–8 weeks prior to the LIFT procedure to ensure resolution of ongoing inflammation and sepsis, although significant differences in healing in the absence of seton placement have not been reported in the series commenting on this issue.3 , 8 , 9 , 17 Prior to proceeding with the LIFT procedure, the patient is examined in the clinic to confirm absence of residual infection, as defined by lack of induration, fluctuance, erythema, and purulent drainage associated with the external opening.

Surgical Technique

Our patients undergo full bowel preparation prior to surgery, consisting of a polyethylene glycol-based solution and oral antibiotics (neomycin 3 g and metronidazole 3 g, in three split doses). When brought to the operating room, the patient is placed in prone jackknife position and the buttocks taped apart with heavy tape. The choice of general endotracheal anesthesia versus monitored anesthesia care is generally a discussion between the surgeon, patient, and anesthesiologist, with patient safety being the obvious priority. Once anesthesia has been initiated and the patient is draped, an anal block is placed using 0.25 % Marcaine with epinephrine (Fig. 1).

Fig. 1
figure 1

The patient is positioned in prone jackknife, and the buttocks are taped apart with heavy tape. Once the patient has been positioned, an anal block is placed using 0.25 % Marcaine with epinephrine

Full size image

The fistula tract is identified, usually by the existing seton. An anal retractor, either Pratt bivalve or Hill-Ferguson type, is used to examine the anal canal and identify the internal opening. The perianal region is carefully examined to rule out any other pathology, particularly additional fistula tracts. Once ready to proceed, a fistula probe is placed through the tract, and the seton, if present, is removed. The intersphincteric groove is marked on the skin, and a 2–3 cm incision made along this line (Fig. 2). Careful dissection is undertaken, using a combination of electrocautery and blunt dissection, until the fistula tract is identified within the intersphincteric groove (Fig. 3). Injury to the sphincter muscle must be avoided during this maneuver. Palpation of the probe can assist with finding this tract, particularly if it has small caliber. A Lone Star retractor is often helpful in spreading the skin incision and optimizing exposure (Fig. 4).

Fig. 2
figure 2

An incision is created through the previous skin marking. The fistula probe is exiting from the internal and external opening, allowing the seton to be removed without losing the tract

Full size image
Fig. 3
figure 3

Using the probe as a guide, the intersphincteric fistula tract is isolated with electocautery and blunt dissection

Full size image
Fig. 4
figure 4

Identification of the fibrotic fistula tract

Full size image

Once identified, the fistula tract is dissected free circumferentially while the probe remains in place as a guide. A pediatric right angle clamp can greatly assist this dissection, particularly on the road side of the tract. The length of tract exposed must be able to accommodate ligation on both sides, without risking loss of the suture when the tract is divided. Once this is accomplished, the fistula tract is encircled by two free silk ties (usually 2–0) to maintain its position, and the probe is removed. The ties are used to ligate the tract on both sides within the intersphincteric groove, and the tract is sharply divided between the two sutures using a blade (Fig. 5). For additional security, the tract stumps are then suture ligated on both sides using absorbable suture, usually 3–0 vicryl. If the original silk ties slip or are cut during tract division, we attempt to grasp the cut end of the tract and replace the silk tie. If this is not possible, we place one or two 3–0 absorbable suture stitches in a deep figure of eight fashion to complete the ligation; this may require gentle replacement of the fistula probe to reconfirm the location of tract within the intersphincteric groove. Both sides of the divided tract are tested using hydrogen peroxide to verify complete ligation (Fig. 6). An 18 gauge angiocath is used to deliver hydrogen peroxide through the external opening while looking for egress of fluid within the wound. To test ligation of the internal opening, the wound itself is filled with hydrogen peroxide and anal retractors used to look for fluid leak through the internal opening. If leak is seen on either side, an additional 3–0 absorbable suture is used to create a water-tight ligation.

Fig. 5
figure 5

The fistula tract is suture ligated with 2–0 silk ties proximally and distally after removal of the fistula probe

Full size image
Fig. 6
figure 6

The fistula tract is divided between the two ties using a blade and secured on each side using an additional 3–0 absorbable suture (vicryl) for ligation

Full size image

The external portion of the tract is gently debrided using a curette, and the opening is left open (Fig. 7). The internal opening can be similarly cleaned of inflammatory material and is either left open or closed using absorbable sutures. The skin incision is irrigated and closed using 3–0 vicryl deep dermal and 4–0 monocryl subcuticular absorbable sutures (Fig. 8).

Fig. 7
figure 7

A curette is used to debride the external opening of the fistula tract

Full size image
Fig. 8
figure 8

The LIFT wound is closed with 3–0 vicryl deep dermal and 4–0 monocryl subcuticular absorbable suture, and the external opening is left open

Full size image

Postoperative Care

Patients typically undergo LIFT as an outpatient procedure and are sent home after meeting standard postanesthesia discharge criteria. They are advised to cover the incision with a gauze dressing which is changed daily and as needed if saturated. Patients may shower but should avoid soaking baths or swimming in the immediate postoperative period. The incision is monitored for drainage, bleeding, and erythema, and patients are asked to contact their surgeon if they experience any wound changes or fevers. Most patients require narcotic pain medication for a few days and are encouraged to use non-narcotic adjuncts including acetaminophen, ibuprofen, and warm or ice packs. Patients should avoid heavy lifting and are seen in follow-up within 2 weeks for wound check.

Discussion

Anal fistula management is still a challenge for colorectal surgeons. The results in the literature are variable, and no one technique seems to be superior and uniformly successful. The ideal surgical management should result in fistula closure, low recurrence rates, and preservation of anal sphincter functions.

LIFT has been proposed as a sphincter-preserving procedure with success rate ranging from 40 to 95 %3 , 5 – 28 and recurrence rate ranging from 6 to 28 % (Table 1). This operation can treat high transsphincteric fistulae and complex fistulae and can often be considered a second line of treatment when previous procedures have failed.

The large range in healing and recurrence endpoints reported in the literature are due to the heterogeneity of the reported patient populations in terms of prior attempts at repair, type of fistula treated, and preoperative use of setons. In some studies, LIFT is the first choice for transsphincteric fistula, while in others, it is used only for recurrence after prior failed repairs18 with advancement flap, fistula plug, seton, fistulotomy, and/or fibrin glue, with the majority of them including a variety of clinical scenarios.3 , 6 – 17 , 19 – 22 Some groups include multiple fistula tracts, horseshoe fistula, and complex fistula in addition to high transsphincteric fistula as indications for a LIFT procedure.17 The lowest success rate (39.8 %) is reported when patients have undergone multiple previous operations or multiple fistula tracts are present.17 A recent systematic review published by Sirani et al. highlights the challenges of evaluating results for LIFT, emphasizing the variability in technique, heterogeneity of selected patients, and wide range of follow-up available in the current published literature. In the 26 studies they examined, success rates ranged from 47 to 95 %. They particularly emphasized the lack of standard definition of failure or recurrence and associated risk factors, which limits surgeons’ ability to translate these results into their own practice.32

Tan et al.12 have described three patterns of failure after LIFT: localized when a focus of sepsis is still present in the intersphincteric wound and not eradicated during surgery; partial when the external opening becomes more medial resulting in an intersphincteric fistula; and complete when the communication between the internal and external opening persists, which is attributed to the presence of ongoing sepsis making the internal opening too big. When a LIFT fails, it often results in a more manageable fistula. Localized failure can be treated with antibiotics and eventual curettage of the fistula tract. Partial failure can be managed with a fistulotomy because the intersphincteric tract involves a limited amount of sphincter muscle. Complete failure can be managed with insertion of a seton for 8–12 weeks to control and drain the focus of sepsis, allowing maturation of the fistula tract around it.9 , 14 , 19 This can then be followed by a definitive procedure, including another LIFT.9 , 13 , 19

Several factors contribute to failure of a LIFT procedure. Longer tracts decrease healing rates. Liu et al.19 reported an 85 % healing rate in fistula less than 3 cm in length versus 48 % for fistula more than 3 cm in length; this translates to a decrease in the odds ratio of healing by 0.55 for every 1-cm increment in tract length. LIFT is also more successful if used as a first-line treatment. The healing rate for patients who have had 0 or 1 previous operation before LIFT is 90 and 75 %, respectively, versus 65 % for patients who have undergone two or more operations.13 , 18 , 20 Failure in cases of recurrent fistula may be a consequence of underlying disease complexity or may reflect reduced vascularity and increased scar tissue in the perineum due to multiple operative manipulations. To avoid these factors, several authors now consider LIFT to be the first-line treatment for the majority of transsphincteric fistulae. Other factors that can reduce fistula healing rates are diabetes, smoking, and obesity.30 , 33 Abcarian et al.13 report that 37.5 % of smokers and 22.2 % of obese patients did not heal after a LIFT procedure.

Length of follow-up after LIFT is extremely variable in the published series, ranging between 12 weeks and 19 months. Of failures, 80 % are early failures with persistent symptoms or failure at ≤6 months.19 However, even if the average healing time is 4–8 weeks,5 , 8 , 10 , 11 , 19 , 20 depending on the underlying pathology, failures can be detected as far as 12 months after the operation.6 , 8 , 10 , 19 The authors feel that it is critical to follow these patients for at least 1 year in order to reach definitive conclusion on the effectiveness of this approach.

Continence is difficult to assess after fistula-in-ano surgery, especially when patients have undergone multiple operations. Decreased continence and frank incontinence have been seen in 67 % patients after cutting seton34 and 35 % of patients after advancement flap.35 However, the data available has demonstrated that the LIFT procedure is a sphincter-saving technique resulting in minimal impact on continence even when addressing high transsphincteric fistula (Table 1).3 , 5 – 11 , 19 – 22 A recent study using anal manometry prior to and 3 months after the procedure, in addition to simple clinical evaluations by validated tools and questionnaires to assess continence, detected no significant changes in resting pressure and squeeze pressure.20

Even if sphincter division is limited to the lower third of the external anal sphincter, the risk of incontinence is still present, especially in patients with decreased anal sphincter function and females with anterior fistula tracts. The rate of incontinence increases with the amount of anal sphincter divided. LIFT procedures allow preservation of the internal and external sphincters by working in the intersphincteric plane. For these reasons, even patients with low transsphincteric fistulae are eligible for LIFT.21

Endorectal advancement flap is an alternative sphincter-preserving technique proposed for definitive treatment of high transsphincteric fistula. In a recent randomized trial, Madbouly et al.22 compared LIFT and mucosal advancement flap (MAF), reporting 1-year healing rates of 74.3 % for LIFT compared with 65.7 % for MAF. LIFT patients did not report any problem with continence versus five MAF patients who reported worsening of continence for flatus and soiling. In addition, LIFT patients had lower pain scores and shorter healing time. In another smaller and non-randomized series,15 MAF was reported to have a better success rate as definitive management of fistula after seton insertion (93.5 % MAF vs 62.5 % LIFT), but these results are limited by group heterogeneity and shorter follow-up in the MAF group. LIFT seems to be a simpler and technically easier option than MAF, which remains technically challenging with a higher risk of incontinence.14

Ellis has described a variation of the LIFT technique,7 in which a bioprosthetic graft is placed in the intersphincteric space to reinforce the closure; the successful rate of this so-called BioLIFT technique was 94 % with a median follow-up of 15 months. Potential drawbacks of this approach include the high cost of the bioprosthetic material, and the more extensive dissection needed in the intersphincteric space to allow the material to overlap the tract by 1–2 cm in all directions.7 More recently, Bastawrous et al. described a novel modification in which the fistula tract is unroofed between the internal opening and the intersphincteric groove, essentially performing an internal sphincterotomy and obliterating the internal opening, while ligating the external portion of the tract within the groove. Among 56 retrospectively reviewed cases, they report an overall cure rate of 74 %, with 9 % having temporary incontinence to stool or flatus, presumably as a consequence of the sphincterotomy.36

Conclusion

The LIFT procedure should be considered as a first-line treatment for patients with high and low transsphincteric fistula tract. In addition, it can be used after seton placement or when other procedures have failed to manage fistula-in-ano. When LIFT fails, it often results in a more superficial intersphincteric tract that in most cases can be treated with a simple fistulotomy or a second attempt at LIFT. No significant postoperative changes in continence have been reported uniformly in the literature. In our practice, we have embraced LIFT as a first-line therapy for transsphincteric fistula, as well as a strong option for recurrent or otherwise complex fistulae.