Introduction
Perianal fistulas of cryptoglandular origin cause considerable discomfort and arise from infections in anal glands lying in the intersphincteric space [
1]. To delineate the fistula tract, magnetic resonance imaging (MRI) and anal endosonography are nowadays readily available and are increasingly used for fistula imaging [
2]. The essence of surgical treatment of perianal fistulas is to eradicate the fistula tract and at the same time preserve continence. Low fistulas, where the fistula tract is submucosal, intersphincteric or located in the lower third of the external anal sphincter can be treated by fistulotomy with low recurrence rates and relatively little impact on continence [
3]. In patients with high perianal fistulas, the fistula tract is located in the upper two-thirds of the external sphincter. Fistulotomy performed on high fistulas results in loss of sphincter function in a considerable number of patients due to the interference of the external sphincter complex [
4,
5]. There are various alternative surgical options for high fistulas, namely, rectal advancement, fibrin glue, and seton drainage.
In 2006, Johnson et al. [
6] reported a new biologic anal fistula plug to treat high transsphincteric perianal fistulas. The anal fistula plug is biologic absorbable and consists of lyophilized porcine intestinal submucosa. In their series of 46 patients treated with the anal fistula plug, a success rate of 83% was achieved at a median follow-up of 12 months [
7]. After this publication, several authors have reported their experience with the anal fistula plug, resulting in success rates ranging from 41–88% [
8‐
10].
Currently, the transanal rectal advancement flap (AF) remains the “gold standard” in the treatment of high transsphincteric perianal fistulas of cryptoglandular origin. The rationale behind the AF is that the open internal opening is the cause of the persisting fistula tract. By advancing the tissue over the internal opening, it would be impossible for fecal material to be forced into the fistula tract during defecation. However, recurrence rates of the advancement flap found in literature vary considerably and extend up to 63% [
11‐
15]. Roughly, one out of every four patients requires multiple surgical interventions to close the fistula tract successfully.
In recent decades, fibrin glue has appeared as an alternative treatment for high perianal fistulas. As a result of the obliteration of the fistula tract and the closure of the internal opening, the fistula might heal. Early results seemed promising, with high success rates being reported. However, with increasing follow-up, the enthusiasm was tempered because of disappointing results [
16‐
20]. Recently, Zmora et al. [
21] conducted a retrospective study including 37 patients with high perianal fistulas. In a subset of 13 patients with fistulas of various etiologies, the advancement flap was used in addition to the fibrin glue installation. The results showed a recurrence rate of 46%.
The aim of this study was to assess the additional value of fibrin glue to the transanal rectal advancement flap in a well-defined group of patients with high transsphincteric fistulas of cryptoglandular origin. Patients with previous fistula surgery are a surgically more challenging group as the result of scar tissue and sometimes anal stenosis. Therefore, patients were matched for the presence of a history of fistula surgery.
Results
In the study period, a total of 127 patients were operated for high perianal fistulas. Inflammatory bowel disease (
n = 30), HIV (
n = 12), or no internal opening found during surgery (
n = 5) were the reason of exclusion in 47 patients. In total, 80 patients were analyzed in this comparative study. Of these, 54 patients were treated with the AF and 26 patients underwent AF combined with the installation of fibrin glue. Furthermore, patients were matched for a history of fistula surgery. Patient characteristics for both groups are shown in Tables
1 and
2. The groups were comparable for patients’ characteristics as sex, age, smoking, seton drainage, and number of tertiary referrals.
Table 1
Characteristics of patients with high anorectal fistula without previous fistula surgery
M/F (n) | 18:14 | 6:3 | 0.711 |
Age (median, in years) | 42 (21–67) | 41 (29–55) | 0.653 |
Tertiary referral | 26 (81%) | 7 (78%) | 1.000 |
Smoking | 43% | 71% | 0.232 |
Seton drainage | 18 (56%) | 6 (67%) | 0.711 |
Table 2
Characteristics of patients with high anorectal fistulas with previous fistula surgery
M/F (n) | 18:4 | 11:6 | 0.282 |
Age (median, in years) | 43 (22–62) | 47 (35–72) | 0.136 |
Tertiary referral | 15 (68%) | 8 (47%) | 0.209 |
Smoking | 53% | 50% | 1.000 |
Seton drainage | 10 (46%) | 12 (71%) | 0.193 |
Discussion
High perianal fistulas remain a surgical challenge. There are various treatment options for treating high transsphincteric fistulas, e.g., the rectal and anodermal advancement flap, loose and cutting seton, fibrin glue, and potentially the newly developed anal fistula plug [
3]. However, the results from these therapies vary. Transanal rectal advancement flap is nowadays the treatment of choice because of its sphincter-saving approach. Due to the low recurrence rate of only 30%, which leaves a lot of room for improvement [
11,
14], fibrin glue has been widely studied. Fibrin glue was developed to obliterate the fistula tract by stimulating fibroblasts, which leads to permanent closure of the fistula tract. Unfortunately, the long-term results were not as good as expected [
19,
20]. In the present series, an attempt was made to decrease the recurrence rate of the surgical treatment of high transsphincteric perianal fistulas of cryptoglandular origin by combining the two methods, i.e., fibrin glue and the rectal advancement flap in a consecutive series of patients. Overall, although not significant, a clear trend was found consisting of a worse outcome for patients from the AF + G group. The recurrence rate was 46% compared to 17% in the AF + G and AF group, respectively. In the group without a history of fistula surgery, patients in the AF + G group did significantly worse than the AF group. In the group with a history of fistula surgery, no significantly different recurrence rates were found.
In 2003, Zmora et al. [
21] described a small retrospective series of 13 patients with perianal fistulas of different origins treated with fibrin glue in combination with the AF [
14]. In their series, a recurrence rate of 46% was found after a mean follow-up of 12.1 months. The group contained patients with fistulas of cryptoglandular origin and fistulas associated with Crohn’s disease or surgical trauma. In addition, two patients with rectovaginal fistulas were included. More recently, Ellis and Clark [
23] reported on a series of 58 patients randomized into advancement flap repair alone or advancement flap repair combined with fibrin glue. Selected were patients with perianal fistulas where the fistula tract comprised more than 30 to 50% of the sphincter complex. Furthermore, patients were included when the fistula was located anteriorly in women or when the patient had a history of incontinence. In two thirds of the patients, the mucosal advancement flap was used and the remaining patients were treated by anodermal advancement flap. The recurrence rate was significantly higher in the group where fibrin glue was combined with the advancement flap compared to the group treated only by advancement (46% vs 20%). Two techniques, i.e., mucosal advancement flap and anodermal advancement flap, were used. Furthermore, no information was provided on the distribution of causes of the fistulas in both groups making the results difficult to interpret.
The effectiveness of the AF is the result of the closure of the internal opening [
24]. The reason why addition of fibrin glue fails to decrease the recurrence rate and even seems to worsen the result is still unclear. After AF, the fistula tract acts as a drainage canal for any remaining sepsis, with the external opening left open. With the installation of the fibrin glue, a temporary closure of the fistula tract is theoretically achieved. After a few weeks, when the clot resolves, the fibroblasts activated by the matrix should provide collagen syntheses for a definitive closure of the tract [
25]. A possible explanation to why the AF + G group does worse is that the closure of the fistula tract with the fibrin glue leads to a situation where insufficient drainage from the primary and eventual secondary fistula tracts occurs.
Sentovich reported on a prospective series of 48 patients (75% of cryptoglandular origin) treated with fibrin glue [
20]. In their technique of using the fibrin glue, the procedure was combined with closure of the internal opening with only a figure eight suture without an advancement flap. After a median follow-up of 22 months, a recurrence rate of 31% was found. Surprisingly, the patients with longer fistula tracts did significantly worse than those with short fistula tracts. Loungnarath et al. [
26] reported on 39 patients with perianal fistulas treated with fibrin glue. The overall recurrence rate was 69%. In 6 of the 39 patients, the internal opening was closed using a figure eight suture to avoid clot extrusion because of high pressure from the anal canal during defecation. Four of these patients had a recurrence (33%).
This retrospective study, in contrast to earlier studies [
21,
23], assessed the additional value of fibrin glue to the transanal rectal advancement flap of only patients with high transsphincteric fistulas of cryptoglandular origin with a long follow-up. The rectal advancement flap combined with fibrin glue installation was associated with a significantly higher recurrence rate, compared to the advancement flap treatment alone, in patients without previous fistula surgery. This observation must be interpreted carefully because of the small sample size of the AF + G group. As the costs of the fibrin glue are considerable and the therapeutic effect very doubtful, it cannot be recommended routinely in the adjunct of transanal rectal advancement flap treating high perianal fistulas. The rectal advancement flap remains the treatment of choice for high transsphincteric perianal fistulas of cryptoglandular origin until novel methods like the anal fistula plug are studied sufficiently in randomized trials.