Sphincter-saving therapy for fistula-in-ano: long-term follow-up after FiLaC®

Abstract

Background
The treatment of anal fistula remains a challenge between maintaining continence and radical surgery to prevent recurrence. Fistula-tract Laser Closure (FiLaC®) is a sphincter-saving technique using a radial emitting laser fibre to close the fistula tract. The aim of this study was to report long-term outcomes in patients who received FiLaC® therapy for transsphincteric and intersphincteric anal fistula between January 2011 and December 2017.MethodsA retrospective study was performed on patients who were treated with FiLaC®- for a transsphincteric and intersphincteric anal fistula at our institution between January 2011 and December 2017. In all patients, the FiLaC® procedure was combined with a closure of the internal orifice using a simple 3-0 Z stitch. Patient characteristics, previous proctological history, healing rates, failures and postoperative continence were investigated.ResultsThe study included 83 patients [mean age 50.01 ± 14.59 years. 64 (77.1%) males] with a mean follow-up period of 41.99 (± 21.59) months (range 4–87 months). Thirteen patients (15.7%) had a recurrent fistula. 65 patients (78.3%) had undergone prior abscess drainage with insertion of a seton. The primary healing rate was 74.7% (62 of 83 patients) overall. Eleven (13.3%) of the 21 patients (25.3%) who failed FiLaC®-therapy underwent a second operation. In eight cases, Re-FiLaC® and in three cases, fistulectomy with closure of the internal orifice was performed. Afterwards 6 (54.5%) of these 11 patients could be considered cured: 3 who had fistulectomy and three who had Re-FiLaC® treatment. The overall healing rate after second FiLaC® was 78.3% (65 of 83 patients) while the overall healing rate for FiLaC® therapy combined with any second procedure was 81.9% (68 of 83 patients). The follow-up period in this group of 11 patients who received re-operation was 38 months (range 13–84 months). Changes in continence occurred in eight patients (9.6%). No patient reported major incontinence postoperatively.Conclusions
The FiLaC® procedure is associated with good healing rates in long-term follow-up and should be considered as a treatment option for transsphincteric and intersphincteric anal fistulae, especially due to the low complication rate and low risk of sphincter injury.

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Techniques in Coloproctology (2021) 25:177–184
https://doi.org/10.1007/s10151-020-02332-4
ORIGINAL ARTICLE
Sphincter‑saving therapy forfistula‑in‑ano: long‑term follow‑up
after FiLaC®
A.Wolicki1 · P.Jäger1· T.Deska1· M.Senkal1
Received: 24 March 2020 / Accepted: 17 August 2020 / Published online: 31 August 2020
© Springer Nature Switzerland AG 2020
Abstract
Background The treatment of anal fistula remains a challenge between maintaining continence and radical surgery to prevent
recurrence. Fistula-tract Laser Closure (FiLaC®) is a sphincter-saving technique using a radial emitting laser fibre to close
the fistula tract. The aim of this study was to report long-term outcomes in patients who received FiLaC® therapy for trans-
sphincteric and intersphincteric anal fistula between January 2011 and December 2017.
Methods A retrospective study was performed on patients who were treated with FiLaC®- for a transsphincteric and inter-
sphincteric anal fistula at our institution between January 2011 and December 2017. In all patients, the FiLaC® procedure
was combined with a closure of the internal orifice using a simple 3-0 Z stitch. Patient characteristics, previous proctological
history, healing rates, failures and postoperative continence were investigated.
Results The study included 83 patients [mean age 50.01 ± 14.59years. 64 (77.1%) males] with a mean follow-up period
of 41.99 (± 21.59) months (range 4–87months). Thirteen patients (15.7%) had a recurrent fistula. 65 patients (78.3%) had
undergone prior abscess drainage with insertion of a seton. The primary healing rate was 74.7% (62 of 83 patients) overall.
Eleven (13.3%) of the 21 patients (25.3%) who failed FiLaC®-therapy underwent a second operation. In eight cases, Re-
FiLaC® and in three cases, fistulectomy with closure of the internal orifice was performed. Afterwards 6 (54.5%) of these
11 patients could be considered cured: 3 who had fistulectomy and three who had Re-FiLaC® treatment. The overall healing
rate after second FiLaC® was 78.3% (65 of 83 patients) while the overall healing rate for FiLaC® therapy combined with any
second procedure was 81.9% (68 of 83 patients). The follow-up period in this group of 11 patients who received re-operation
was 38months (range 13–84months). Changes in continence occurred in eight patients (9.6%). No patient reported major
incontinence postoperatively.
Conclusions The FiLaC® procedure is associated with good healing rates in long-term follow-up and should be considered
as a treatment option for transsphincteric and intersphincteric anal fistulae, especially due to the low complication rate and
low risk of sphincter injury.
Keywords Anal fistula· Fistula tract laser closure· FiLaC· Sphincter-saving
Introduction
Fistula-in-ano is a common anorectal disease that is asso-
ciated with a decreased quality of life [1, 2]. Despite the
advances made in recent years, the treatment of fistula-
in-ano remains a challenge due the difficulty of maintain-
ing continence while preventing recurrence [3]. Effective
therapy may lead to fecal incontinence particularly in the
treatment of high transsphincteric and intersphincteric fis-
tula. Most patients are more interested in preserving conti-
nence than in definitive fistula treatment [4].
Therefore, the latest research concentrates especially on
sphincter-sparing procedures for the therapy of anal fistula.
The sphincter-sparing procedures include ligation of the
intersphincteric fistula tract (LIFT) [5], video assisted anal
fistula treatment (VAAFT) [6], anal fistula plug [7] and the
use of several biomaterials [8].
Another minimally invasive technique that is currently
under investigation is fistula tract laser closure (FiLaC®).
Wilhelm presented this procedure for the first time in a pilot
* A. Wolicki
ninasprzagala@t-online.de
1 Department ofGeneral andVisceral Surgery, Marien
Hospital Witten, Teaching hospital oftheRuhr University
Bochum, Marienplatz 2, 58452Witten, Germany

178 Techniques in Coloproctology (2021) 25:177–184
1 3
study in 2011 [9]. Since then, the method has been modified
and applied by study groups in Turkey and Italy [10–12].
The fistula tract is destroyed using a radial-emitting laser
fiber. This technique can be combined with an additional
method to close the internal orifice [9].
The reported healing rates vary between 20 and 82%
depending on the surgical technique used. When FiLaC®
is combined with a closure of the internal orifice healing
rates can rise to 82% [9]. An overview of the current status
of research regarding the outcome of the FiLaC® procedure
is given in Table1. There appears to be only a low risk of
complications or changes in continence. However there is a
lack of long-term follow-up in the available studies.
In this study, we present our experience with FiLaC®
since we began using this procedure in 2011. Data were
analyzed with a focus on effectiveness and safety of this
procedure including pre- and postoperative continence.
Materials andmethods
Study design andpatients
This single-center study included 83 patients with anal fis-
tula, who were treated with FiLaC®- between January 2011
and December 2017.
This study was approved by the local ethics committee.
Written informed consent for the operation was obtained
from all patients.
Preoperative evaluation included a thorough medical his-
tory and clinical examination (digital and procto-sigmoidos-
copy). Further diagnostic included endoanal ultrasonogra-
phy (Hitachi EUB-5500) and, if necessary, MRI.
Indications for the FiLaC®-procedure were transsphinc-
teric or intersphincteric fistula. Exclusion criteria were signs
of inflammation (presence of abscess), wide fistula tract
(more than 8mm) or cavities and fistula related to malig-
nancy. Very superficial fistula were treated by fistulotomy,
when it could be performed without causing sphincter
damage.
Sixty-five patients underwent drainage of a perianal
abscess in a primary operation with identification of the
Table 1 Comparison of FiLaC® studies in the literature
FiLaC fistula tract laser closure; LAFT laser ablation of fistula tract
Study No. of patients Previous fistula
surgery, n (%)
Seton drainage Treatment type Energy, watts Follow-up period,
moths, median
(range)
Success
rate,
(%)
Wilhelm [9] 11 NA Yes (NA) FiLaC® + exci-
sion of internal
and external
ostium + flap
13 7.4 (2–11) 81.8
Giamundo [10] 35 25 (71) In 16 patients FiLaC® only 10 13 (980nm) 20 (3–36) 71.4
Öztürk [12] 50 NA Yes (NA) in case of
abscess
FiLaC® only 15 12 (2–18) 82.0
Giamundo [13] 45 35 (78) In 24 patients
(10weeks)
FiLaC® only 12 30 (6–46) 71.1
Wilhelm [14] 117 16 (14) In 99 patients
(16.1weeks)
FiLaC® + exci-
sion of internal
and external
ostium + flap or
suture closure
13 25.4 (6–60) 64.0
Lauretta [15] 30 22 (73.3) In 26 patients
(5.1months)
FiLaC® only 12 11.3 (6–24) 33.3
Terzi [11] 103 53 (52) No FiLaC® only 12 28.3 (2.3–50) 40.0
Marref [16] 68 37 (54.4) Yes (3.5month) FiLaC® only 12–15 6.3 (4.2–9.3) 45.6
Stijns [17] 20 NA In 15 patients
(12weeks)
LAFT (CORONA™
fistula probe) only
10 10 20.0
Present study 83 26 (31.3) In 65 patients
(6.9weeks)
FiLaC® + exci-
sion of external
ostium + internal
suture closure
12 41 (4–87) 74.7

179Techniques in Coloproctology (2021) 25:177–184
1 3
internal orifice and seton drainage using a 2-mm latex ves-
sel loop (Ethiloop™, Ethicon®).
Eighteen patients had a chronic fistula without inflam-
mation and underwent immediate fistula repair by laser. In
these cases, the seton was placed at the commencement of
the FiLaC®-procedure.
Surgical technique
Preoperative bowel preparation and antibiotic prophylaxis
were not required.
All laser procedures took place in a clinical setting under
general or epidural anesthesia.
The FiLaC®-procedure was performed using either
a “Ceralas®” or more recently, a “Leonardo® DUAL 45”
diode laser (Biolitec biomedical technology GmbH, Ger-
many). The laser fiber delivers energy at a wavelength of
1470nm homogenously at 360°. This radial-emitting laser
fiber causes shrinkage of the surrounding fistula tract and
destroys the tract to a depth of 2mm.
The laser fiber was introduced through the external ori-
fice in Seldinger technique using the seton as a guidewire.
After it was placed on mucosal level, the fiber was with-
drawn with a speed of 1mm per 1s by applying energy of
12 Watts. As a result, the energy delivered per centimeter
is 120J. The internal orifice was closed using a 3/0 Vicryl
suture and performing a Z-stitch. The external orifice was
excised with a diameter of 10–15mm and send for histologi-
cal examination.
Postoperatively, there were no dietary restrictions, and
all patients were placed on stool softeners for the duration
of their hospital stay. Patients were discharged on the 2nd
postoperative day after they were instructed to clean the
external wound in the shower after defecation and at least
two times daily.
Follow-up examinations were performed in the second
postoperative week and afterwards at fortnightly intervals.
The patients were instructed to return to the clinic if symp-
toms recurred.
Data collection
Data recorded for the study included patient characteristics,
symptoms, recurrence of fistulae or symptoms, following
operations and pre- and postoperative continence. Anal
continence was assessed with the Cleveland-Clinic-Score
(CCS). Incontinence was classified in major and minor
incontinence. Major incontinence included incontinence
to liquid and solid stool and minor incontinence included
incontinence to gas and minor soiling.
Data were collected using the hospital information system
and telephone interviews. Permanent healing was defined
as closure of the internal orifice and external orifice and the
absence of pain or leakage. Otherwise anoscopy or endoanal
ultrasound examination was performed to asses a recurrence
or persistent fistula.
All patients underwent regular outpatient follow-up
examinations after the FiLaC® procedure. Follow-up ended
when wound healing was complete.
In the telephone interviews, detailed questions were
asked about complaints such as bleeding, secretion, itching,
open sores. Patients with complaints, were asked to come
to the clinic for a follow-up examination and patients who
denied these complaints, were classified as cured. The tel-
ephone interviews also included questions about hospital
stays in other clinics and operations that followed after the
FiLaC®-treatment. All telephone interviews were held using
the same structured questionnaire.
Statistical analysis
The anonymized data were entered in Excel. Statistical anal-
ysis was performed using software “R” (R version 3.4.4).
For statistical analysis, the packages “lmtest” [18], “dplyr”
[19], “magrittr” [20], “psych” [21] and “ggpubr” [22] were
used. For graphical presentation, the R – package “ggplot2”
[23] was used.
First, the data of this survey were presented descriptively.
To assess relevant patient characteristics for the healing rate,
a univariate statistical analysis was performed. Therefore,
the binary variable “primary healing” was developed, dis-
tinguishing “yes” if the above mentioned criteria of perma-
nent healing were fulfilled and “no” otherwise. In case of an
interval or ratio measurement of these characteristics, a two-
sided t test was carried out after. A normal distribution of the
respondent variables was tested using the Shapiro–Wilk test
and homoscedasticity was tested with the Breusch–Pagan
test beforehand. P values < 0.05 were considered statistically
significant.
For detecting the influence of non-metric variables on
the outcome, a test of given equal proportions (based on a
Pearsons Chi squared test statistic) was performed. In case
of discrete, e.g., binary values (that cannot be approximates
by a continuous Chi square distribution) or a sample size < 5
within the contingency table, a Yate’s correction for continu-
ity is used. For determining the strength of association, the
Phi (φ) coefficient is presented.
The full reproducible code is available from the author
on request.
Results
Between January 2011 and December 2017, 286 surgi-
cal procedures were performed on patients with anal fis-
tula (Fig.1). Two hundred and twenty-nine patients had

180 Techniques in Coloproctology (2021) 25:177–184
1 3
FiLaC®- for transsphincteric or intersphincteric fistula.
There were no current contact details available for 29
patients. Eighty-three of the other 200 patients agreed to
be interviewed.
Seventy-two patients (86.7%) were interviewed by
telephone. In 11 cases (13.2%), the interview took place
at the clinic and clinical examination with anoscopy and
endoanal ultrasonund was performed.
All 83 patients had been treated with FiLaC® combined
with a suture closing of the internal orifice. The overall
mean age was 50.01 ± 14.59 (range 13–80) years and 64
(77.1%) were male.
Sixty-five patients (78.3%) underwent prior abscess
drainage with insertion of a seton. The primary heal-
ing rate was 81.5%. The median time between seton
insertion and definitive fistula treatment was 6.9weeks
(3.9–208weeks). Eighteen patients (21.7%) presented
themselves with a chronic fistula without abscess or other
signs of inflammation for definitive fistula operation. The
healing rate in this group was 50.0%.
In 76 cases (91.6%), the patients had had previous sur-
gery including abscess drainage and prior fistula opera-
tions. Twenty-eight patients (33.7%) had had prior fistula
operations, five of these patients underwent multiple opera-
tions. Thirteen patients (15.7%) had a recurrent fistula after
previous operation. Of these 13 patients, 9 had undergone
fistulectomy, 3 fistulotomy and in 1 patient closure of the
internal ostium was performed with an over-the-scope-clip
(OTSC) clip. The healing rate in case of a primary fistula
was 72.9% and 84.6% in the group of patients after previous
fistula surgery.
Eighty-one fistulae (97.6%) were of cryptoglandular ori-
gin and two fistulae (2.4%) were Crohn-related. The primary
healing rate of the patients with Crohn’s disease was 50.0%.
The patient with the persistent fistula received second
FiLaC®-treatment and was afterwards free of complaints.
The mean length of follow-up was 41.40 ± 21.34months
(range 4.8–87.6months) (Fig.2).
The primary healing rate was 74.7% (62 of 83 patients)
overall. To identify potential factors for success of primary
Fig. 1 Flow diagram of the study

181Techniques in Coloproctology (2021) 25:177–184
1 3
healing, univariate analysis with a number of independent
variables was performed. The primary healing rates in rela-
tion to the different variables are listed in (Table2). Higher
failure rates were only found in patients with an anteriorly
located internal orifice vs. patients with a posteriorly located
internal orifice.
In 21 (25.3%) cases, there was a relapse. In the postop-
erative period, the majority of the patients (n = 62–74.4%)
did not have any complications. However, 11 patients
reported pain and 7 reported bleeding. The reported bleed-
ing appeared in the context of wound healing. No transfusion
or reoperation was needed in any of the cases. The patients
who reported pain complained about restrictions in daily
life, especially in sitting, that caused pain in the wound area.
This pain lasted on average 3weeks and required analgesic
treatment with non-steroidal anti-inflammatory drugs or
metamizole.
In 14 patients, wound healing complications affecting
the external orifice were recorded. In five patients, a re-
operation was carried out. A persistent fistula was excluded
either preoperatively with an MRI scan or intraoperatively.
These patients underwent operative excisional debridment
with removal of necrotic or granulation tissue.
Eleven patients (13.3%) of 21 (25.3%) who failed
FiLaC®-therapy underwent a second operation. In eight
cases, Re- FiLaC® and in three cases fistulectomy followed
by closure of the internal opening with a z stitch was
performed. Afterwards six patients (54.5%) of these 11
patients could be released from the treatment as cured.
Three of the eight patients who had received the second
laser treatment were symptom-free afterwards. The over-
all success rate of FiLaC® treatment increased after the
second laser treatment from 74.7% (62 of 83 patients) to
78.3% (65 of 83 patients). The overall healing rate for
FiLaC® therapy combined with any second procedure
was 81.9% (68 of 83 patients). The follow-up period in
this group of 11 patients who received re-operation was
38months (range 13–84 months). The postoperative
treatment and examinations were equal to the primary
operation.
No major-incontinence (solid or liquid stool) was reported
postoperatively. In patients who underwent a second treat-
ment, the assessment of continence was carried out after the
second treatment. Changes in continence occurred in eight
patients (9.6%). Five patients (6%) had minor soiling and
three patients (3.6%) complained about intermittent occur-
rence of incontinence for gas. Seventy-five patients (90.4%)
did not notice any change in continence postoperatively.
Additionally, continence was assessed using the Cleve-
land Clinic Incontinence Score pre- and postoperatively.
There was no statistically significant change in conti-
nence (preoperative score 0.53 ± 2.42, postoperative score
Fig. 2 Follow-up period in months

182 Techniques in Coloproctology (2021) 25:177–184
1 3
0.73 ± 2.55 on average, p = 0.31, Wilcoxon rank sum test
with continuity correction W = 3282.5).
Discussion
In this follow-up survey, we found a healing rate of 74.70%
after an observation period of 41.99 (± 21.59) months on
average. No variable that affected the success of the opera-
tion significantly could be determined. Postoperatively,
66.27% of the patients had no complaints and there were
no major complications at all. Continence did not change
significantly after the operation.
The FiLaC®-method performed in our study is a modifi-
cation of the FiLaC®-method presented by Arne Wilhelm in
2011. After excising the internal orifice of the fistula, Wil-
helm closed it with an advancement, mucosal or anodermal
flap. In the following studies, most of the surgeons refrained
from closing the internal orifice.
In the present study, the FiLaC®-procedure was combined
with a suture closing of the internal orifice using a 3/0-Vic-
ryl suture. The decision to abstain from flap techniques was
made to reduce operation time and postoperative pain.
The healing rate in this study was 74.7%. This rate is
in line with the published data of the early FiLaC® studies
and the ones in which a closure of the internal orifice was
performed.
The latest studies published in 2018 and 2019 showed
disappointing healing rates between 20% and 45.6% [16,
17]. This may be because there was no closure of the internal
orifice and no excision of the external orifice. The cohorts
seem to be comparable in terms of demographic data.
Another aim of the present study was to identify factors
associated with a successful outcome after FiLaC® surgery.
An association between fistula characteristics and an
increased risk of fistula recurrence was found in a meta-anal-
ysis by Mei etal. They found a correlation between lower
healing rates and fistula characteristics like high transsphinc-
teric fistulae, an undetected internal orifice, the presence of
horseshoe extensions, multiple fistula tracts and previous
anal surgery. It has not yet been established if patient-related
factors play a role [24]. A connection with smoking, diabetes
mellitus and obesity is suspected as well as other conditions
that promote poor wound healing.
It is well known that the treatment of anal fistula in
patients with Crohn’s disease is especially challenging.
Most studies, specifically the studies dealing with FiLaC®,
excluded patients suffering from Crohn’s disease from
analysis. But this group of patients is one that suffers more
frequently from fistulae with a high-risk for recurrence and
Table 2 Patient characteristics and healing rates after FiLaC®
FiLaC fistula tract laser closure, BMI body mass index
Patient characteristics nOverall Primary healing
Yes (%) No (%)
n83 62 (74.7) 21 (25.3)
Age, years mean (SD) 83 50.01 49.76 50.76 p = 0.80, CI = − 8.96–6.96
Sex Male 64 48 (75) 16 (25) p = 1; X2 = 0.00, df = 1,
CI = − 0.22–0.25, φ = 0.01
Female 19 14 (73.7) 5 (26.3)
Body mass index, kg/m2Mean (SD) 83 28.99 (5.66) 29.33 (5.50) 28.00 (5.07) p = 0.37, W = 737.5, r = 0.1,
CI = − 0.14–0.3
BMI > 30kg/m224 19 (79.2) 5 (20.8) p = 0.75, X2 = 0.10, df = 1,
CI = 0.69–0.76, φ = − 0.07
Prior abscess drainage if there was
any inflammation
Yes 65 53 (81.5) 12 (18.5) p = 0.56, X2 = 0.34, df = 1,
CI = − 0.17–0.38;
φ = −0.10
No 18 9 (50.0) 9 (50.0)
Primary fistula Yes 70 51 (72.9) 19 (27.1) p = 0.58, X2 = 0.30, df = 1,
CI = − 0.38–0.15; φ = -0.10
No 13 11 (84.6) 2 (15.4)
Internal orifice site Anterior 33 19 (23.17) 14 (15.85) p = 0.01, X2 = 7.06, df = 1,
CI = − 0.50–0.06; φ = –0.32
Posterior 50 43 (52.44) 7 (8.4)
Diabetes mellitus Yes 15 10 (66.7) 5 (33.3) p = 0.64, X2 = 0.21, df = 1,
CI = − 0.20–0.40, φ = 0.09
No 68 52 (76.5) 16 (23.5)
Smoker Yes 35 29 (82.9) 6 (17.1) p = 0.23, X2 = 1.45, df = 1,
CI = − 0.44–0.08; φ = -0.16
No 48 33 (68.75) 15 (31.25)
Follow-up-period in weeks, mean (SD) 83 180.52 (92.81) 178.93 (95.38) 185.21 (86.83) p = 0.81, W = 627, r = − 0.03,
CI = − 0.23–0.17

183Techniques in Coloproctology (2021) 25:177–184
1 3
would therefore particularly benefit from a procedure that
is minimally invasive and sphincter-saving.
Alam etal. evaluated retrospectively patients with
Crohn’s disease that underwent FiLaC®-therapy [25].
They found a healing rate of 55% with a median follow-up
period of 7.1months. No closing of the internal orifice was
performed. All patients received pretreatment with a loose
seton and this lasted on average 9.5months. However, the
healing rate in this study was higher than in comparable
studies with patients not suffering from Crohn’s disease.
The role of the seton is controversial [26]. The hypoth-
esis behind seton insertion is that the width of the fistula
tract will be reduced and he inflammation eliminated. The
laser reaches a penetration depth of 2–3mm at the wave-
length of 1470nm. In consequence, it causes only minimal
damage to the surrounding tissue and the sphincter muscle.
In case of a very wide fistula tract or an abscess cavity,
the laser cannot reach the walls and does not destroy the
fistula epithelium. The seton is designed to prevent this.
Lateral ducts should also be dried out. Giamundo etal.
found a better outcome in a group of patients treated with
a seton before definitive fistula therapy [10]. Probably due
to a small number of patients, there were no statistically
significant results.
However, there is no data about the optimal period of
time for the seton to be in place or whether an advantage is
achieved at all. In the present study, the seton was inserted
for an average of 6weeks. The decision about the timing was
made due to clinical factors including the amount and type
of secretion, presence of pus and the local wound conditions
after abscess surgery.
Besides, higher failure rates were found in patients in
whom the internal orifice was anteriorly located. So far
there is no clear explanation for this. Wilhelm analyzed
the patients with failure after FiLaC® and found a dis-
talization of the fistula tract in many cases during reop-
eration [14]. This is in accordance with our experienceof
9years of FiLaC®-surgery. We think that therefore the
FiLaC®-operation can also be considered a preliminary
operation, e.g., in patients with high fistulae. Scarring is
minimal, there is less pain due to the small wounds and a
second operation is not complicated but simplified.
In some cases, wound healing problems occurred in the
area of the external opening and necessitated reoperation.
Sometimes the external opening has to be re-excised. The
hypothesis is that these wound healing disorders are due to
the skin healing occurring before healing of the fistula, for
example in patients with long fistula tract.
The results of this study confirm that FiLaC® is a sphinc-
ter-saving technique. No major incontinence occurred post-
operative and there was no statistically significant change in
pre- and postoperative continence assessed with CCS. All
the studies published to date havesimilar results.
The main limitations of this study are its retrospective
nature, the small number of patients as well as the single-
center design. The majority of patients could not be inter-
viewed because of the missing written informed consent.
Another limitation is the lack of differentiation between
transsphincteric and intersphincteric fistulas. One reason for
this is the inconsistent performance of preoperative imaging.
Also, related to this, is the lack of documentation of the fistula
type in the hospital information system. As a result, statistical
analysis was limited and an underestimation of relevant covari-
ates cannot be excluded. Since the survey was carried out on a
voluntary basis, selection biases cannot be ruled out.
In general, we see the main benefit of the FiLaC® procedure
in its minimally invasive approach. After FiLaC® patients were
quickly able to return to their everyday life because there was
less pain, small wounds and no sphincter damage. The FiLaC®
procedure can also be performed on an outpatient basis. This is
a big advantage compared to fistulectomy. And a further opera-
tion can be performed at any time without restrictions. Patient
comfort is increasingly becoming the focus of attention. Today,
patients are well informed and can therefore also be involved in
the decision on the choice of the surgical procedure.
Conclusions
Our results confirm that FiLaC® is a simple, effective, sphinc-
ter-saving technique. It must be performed carefully and accu-
rately in combination with a closure of the internal orifice and
excision of the external orifice. The learning curve is short.
The present evidence suggest FiLaC® should be more widely
used for transsphincteric and intersphincteric fistula.
Funding The authors declare that there is no funding source.
Compliance with ethical standards
Conflict of interest Author Dr. med. Thomas Deska has received trav-
el grants and speaker honoraria from Company Biolitec biomedical
GmbH Germany.
Ethics approval The study was accepted by the local ethics committee
of the Ruhr University Bochum.
Informed consent All patients undergoing the FiLaC-procedure pro-
vided informed consent.
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