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Anal Injectable and Implantable Bulking Agents for Faecal Incontinence

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Chapter
Anal Injectable and Implantable
Bulking Agents for Faecal
Incontinence
JohnCamilleri-Brennan
Abstract
Faecal incontinence (FI) is a common condition, the prevalence of which
increases with age. It is associated with a negative impact on the quality of one’s
life. The aetiology is multifactorial; hence, both the diagnosis and the treatment
of faecal incontinence may be challenging. A variety of surgical treatments for
faecal incontinence have emerged over the years. One of these is the use of anal
bulking agents. Anal bulking agents have been available for over 25years, with
various studies being published. Initial results were disappointing, mainly due to
lack of efficacy and reliability as well as concerns about safety. Great strides have
been made recently with the introduction of the anal implants Gatekeeper (GK)
and Sphinkeeper (SK). This chapter explores the evolution of anal injectables and
implants, discusses operative techniques and provides a critical analysis of the
results of the various studies to date.
Keywords: faecal incontinence, anal sphincter, anal implants, anal injectables,
analbulking agents, gatekeeper, Sphinkeeper
. Introduction
Faecal incontinence (FI) may be defined as an impaired ability of the control
of the release of flatus or faeces. It is a socially stigmatising condition that may
have an adverse effect on one’s quality of life. From the financial point of view, the
investigation and treatment of faecal incontinence may add to a significant cost to
the health systems of most countries. In fact, the annual treatment cost of patients
in the UK with urinary and faecal incontinence is of about £500 million.
Many factors may be involved in the pathophysiology of FI.A thorough clinical
assessment of the patient is therefore mandatory. This starts with a full history, which
may include a cognitive assessment if necessary. The characteristics of the faeces and
the type and frequency of incontinence should be noted. Urge incontinence is sugges-
tive of poor external anal sphincter (EAS) function, whilst passive and post-defae-
catory incontinence indicates that internal anal sphincter (IAS) function is weak.
Various questionnaires that enable the clinician to quantify the degree of incontinence
and the impact on quality of life are available. These include symptom-specific
questionnaires, such as the ones developed by Vaizey etal. [1] and Wexner etal.[2]
Current Topics in Faecal Incontinence
andthe faecal incontinence quality of life (FIQOL) scale developed by Rockwood
etal. [3], and also generic questionnaires such as the Short Form 36 (SF 36) [4].
A full examination of the patient, including the abdomen and perineum and
a neurological examination in some cases, is necessary. Beneficial investigations
include a flexible sigmoidoscopy, anal manometry (resting and squeeze pressure),
rectal compliance, pudendal nerve terminal motor latency (PNTML) and endoanal
ultrasound (EAUS). Clinicians, however, need to be able to determine which test to
perform, and when, as well as be able to correctly interpret the results.
The management of FI is complex and multidisciplinary, involving the general
practitioner, continence nurse, physiotherapist, gastroenterologist, urologist and
colorectal surgeon. Conservative measures, which include patient education and
support, improvement in diet and bowel habit, judicious use of anti-diarrhoeal
medication and pelvic floor exercises, are used in the first instance. This is, in
fact, recommended in the UK by the National Institute for Clinical Excellence
(NICE) guideline ‘CG49 Faecal Incontinence’ [5]. If these measures fail, surgical
intervention may be necessary. A variety of surgical options are available, with the
appropriate therapy being selected depending on the cause of the incontinence and
the patient’s cognitive function and general physical condition (Table  ). One of the
surgical options available is the use of anal bulking agents.
1. Restoration and improvement of residual sphincter function
a. Correcting a defective external anal sphincter
Sphincteroplasty (end-to-end repair; overlap repair)
b. Correcting a defective pelvic floor:
Levatorplasty
Postanal repair
Total pelvic floor repair
c. Correction of anorectal deformities
d. Sacral nerve stimulation (SNS)
e. Posterior tibial nerve stimulation (PTNS)
2. Increasing the outlet resistance of the anal sphincter
a. Augmentation of the anal sphincter and anal cushions (anal bulking agents)
b. Anal submucosal fibrosis (SECCA)
c. Anal encirclement (Thiersch procedure)
d. Non-dynamic graciloplasty
3. Dynamic sphincter replacement
a. Dynamic graciloplasty
b. Artificial anal sphincter
4. Antegrade continence enema (ACE)
5. Faecal diversion
a. Colostomy
b. Ileostomy
Table 1.
Surgical options in the management of faecal incontinence.
Anal Injectable and Implantable Bulking Agents for Faecal Incontinence
DOI: http://dx.doi.org/10.5772/intechopen.91952
. Anal bulking agents
Anal bulking agents have emerged as a treatment for FI, following the success
of bulking agents for urinary stress incontinence in females. In the urology setting,
bulking agents have been employed to augment the bladder neck and increase
urethral resistance [6]. Therefore, the aim of anal bulking agents is to prevent FI by
closing the anal canal or increasing the pressure within the anal sphincter.
The ideal characteristics of a bulking agent have been described in the literature
[7]. The injected or implanted substance should be biocompatible, non-migratory,
non-allergenic and noncarcinogenic. The substance should also be easy to inject or
implant and should produce an improvement in continence, both in the short term
and in the long term.
. The evidence for anal bulking agents
Anal injectables and implantables have been used to manage faecal incontinence
for over 20years. It may be useful to chart their development over the years and to
classify this development into three phases. The first phase consists of the initial
experimental studies that took place in the 1990s. The second phase, from about
the year 2000 onwards, encompasses an increase in the number of studies using a
wide variety of agents and injection techniques. The third phase features the latest
generation of anal bulking agents, the implantable polyacrylonitrile, available as
Gatekeeper (GK) and Sphinkeeper (SK) devices.
. Initial studies: The first phase
Anal bulking agents were first described in 1993 by Shafik [8]. Shafik, an
Egyptian surgeon, is considered to be a pioneer in this field. In his first study, he
described the outcomes following the injection of 5ml of PTFE (polytef/Teflon)
paste in 11 patients, 7 of whom had incontinence following a lateral internal sphinc-
terotomy for anal fissure. In another study, the same author used 60ml of abdomi-
nal wall fat as a submucosal injection into the rectal neck at 3 and 9 oclock in 14
patients with partial faecal incontinence [9]. Pescatoris group from Rome, Italy,
reported the use of anal injection of autologous buttock fat to restore continence
in one patient who had poor results following a sphincteroplasty. This patient’s
continence improved following repeated injections [10].
The indications for injection of the anal bulking agents in these studies were
various. Most patients had passive FI, but some had urge incontinence, indicating
EAS disruption. The results of these initial studies showed that continence was
improved in the short term. However, the medium- and long-term results were
poor, probably because of the resorption or migration of the injected material.
Reinjection was necessary in order to maintain continence.
A number of safety issues were raised with these studies. Teflon could poten-
tially cause granuloma formation and sarcomas. The injection of autologous fat as a
bulking agent in urology has been implicated in fatal fat embolism and stroke.
. The second phase
The second phase in the development of anal bulking agents consisted of a wide
variation in the types of materials used, surgical technique and clinical indications
[11]. Some of the materials used to bulk the anal sphincter were being used in urol-
ogy to augment the bladder neck. Nine different types of injectable bulking agents
have been used in these studies (Table).
Current Topics in Faecal Incontinence
Type of bulking
agent
Commercial
name(s)
Injection site Injection route Published
studies
No. of
patients
Silicone biomaterial.
Polydimethylsiloxane
elastomer particles
suspended in a
biocompatible
hydrogel made of poly-
N-vinyl-pyrrolidone
PTQ;
Bioplastique
Intersphincteric;
within IAS
Transsphincteric 21 619
Carbon-coated
zirconium beads,
comprised of pyrolytic
carbon-coated beads
suspended in a
water-based carrier gel
containing β-glucan
Durasphere Submucosal Transmucosal;
transsphincteric
7187
Spherical particles
of calcium
hydroxylapatite,
suspended in a gel
Coaptite Submucosal Transsphincteric 110
Dextranomer
microspheres and
stabilised sodium
hyaluronate in
phosphate-buffered
0.9% sodium chloride
solution
NASHA
Dx, Zuidex,
Solesta
Submucosal Transmucosal 5192
Glutaraldehyde cross-
linked collagen
Contigen Submucosal Transmucosal 290
Synthetic non-
particulate hydrogel
consisting of water
(97.5%) and cross-
linked polyacrylamide
(2.5%)
Bulkamid Intersphincteric Intersphincteric 1 5
Cross-linked porcine
dermal collagen
matrix
Permacol Submucosal;
intersphincteric
Transmucosal;
intersphincteric
5172
8% ethylene vinyl
alcohol copolymer
dissolved in dimethyl
sulfoxide. A spongy
solid mass forms from
the solidification
of the hydrophobic
copolymer when the
solvent diffuses away
on contact with tissue
fluid
Onyx34 Intersphincteric Intersphincteric 121
Expandable silicone
microballoons filled
with a biocompatible
hydrogel made of poly-
N-vinyl-pyrrolidone
Submucosal Transmucosal 1 6
Table 2.
Injectable materials used in the second phase of studies.
Anal Injectable and Implantable Bulking Agents for Faecal Incontinence
DOI: http://dx.doi.org/10.5772/intechopen.91952
.. Indications
The clinical indications for which these bulking agents were used varied from
study to study. These were:
• Failure of conservative management of faecal incontinence.
• Structurally intact but weak internal anal sphincter. This would be due to
either primary idiopathic degeneration of the IAS or degeneration secondary
to tissue disorders such as scleroderma.
• IAS damage (childbirth, haemorrhoidectomy, anal stretch, sphincterotomy)
(Figure ).
• Defect in the external anal sphincter.
The main indication was IAS dysfunction or disruption. Unlike the EAS, the IAS
is not amenable to surgical repair.
.. Surgical procedure and technique
The bulking agents may be inserted under local, regional (anal or pudendal
nerve block) or general anaesthesia. The type of anaesthesia used depends on the
preference of the patient and the surgeon. The patient may be positioned in the
prone (jackknife), lithotomy or left lateral positions, although the latter position
may not give a satisfactory view of the anorectum to enable accurate injection. A
phosphate enema is usually administered preoperatively. The procedure is usu-
ally covered by prophylactic antibiotics, such as intravenous (IV) co-amoxiclav
1.2g, cefuroxime 750mg and metronidazole 500mg or gentamicin 1.5mg/kg and
metronidazole 500mg at induction.
Figure 1.
Endoanal ultrasound scan showing a defect in the IAS of a 57-year-old lady with passive faecal incontinence
following haemorrhoidectomy. The defect is present between the arrows from the 3 to the 5 o’clock positions.
Current Topics in Faecal Incontinence
The injection of the bulking agent varies depending on the type of substance
used and the clinical indications. Three different routes of needle insertion were
mentioned in the literature: transmucosal, transsphincteric or intersphincteric. The
bulking agent was placed submucosally, within the intersphincteric space or within
the IAS itself. For example, porcine dermal collagen (Permacol) may be injected
via the transmucosal or transsphincteric route using a disposable 19G needle [12]
(Figure ). In patients with an intact IAS, 2.5ml of Permacol is equally injected
into the submucosal space at the 3, 7 and 11 o’clock positions above the dentate
line. In cases of an IAS defect, 5ml of Permacol may be injected at the site of the
defect, with 2.5ml of the substance injected diametrically opposite. With silicone
biomaterial (PTQ or Bioplastique), four doses of 2.5ml of silicone are used, using
an 18G needle [13, 14]. Patients with an intact IAS have the silicone injected trans-
sphincterically into the intersphincteric space at the 2, 4, 8 and 10 oclock positions.
In patients with an IAS defect, for example, after a lateral internal sphincterotomy,
a total of three doses of 2.5ml of silicone are injected into the defect. A fourth dose
is injected into the intersphincteric space contralateral to the IAS defect, to provide
symmetry. With carbon-coated beads (Durasphere), a total of 10ml is injected in
four divided doses in the submucosal plane using an 18G needle [14].
It is of utmost importance to ensure that the anal mucosa is not breached during
injection, since that would allow intra-anal leakage of the substance. Intravascular
injection must also be avoided.
Once the injection is completed, it is a good practice to leave the needle and
syringe in place for a few seconds. As the needle is being withdrawn, pressure on the
needle track by the index finger may prevent leakage of the bulking agent [12].
The bulking agent may be injected freehand, with an anal retractor such as
Eisenhammer used to identify the IAS and intersphincteric groove. A finger placed
within the anal canal may be useful to guide the needle to its correct position.
However endoanal ultrasound has been recommended to guide the needle to an
optimum position [13], especially if the agent is to be injected into the intersphinc-
teric space or adjacent to a defect in the IAS.
.. Results
The majority of studies in this second phase of development were mainly case
series and observational studies. Most of these studies reported either an improve-
ment in the faecal continence scores or less frequent episodes of incontinence over
time. Anorectal manometry testing is featured in some studies, with some showing
an improvement in resting or squeeze pressures. Others studies showed no such
improvement. Clinical improvement was not always associated with an increase in
Figure 2.
Porcine dermal collagen (Permacol) in a 2.5ml syringe.
Anal Injectable and Implantable Bulking Agents for Faecal Incontinence
DOI: http://dx.doi.org/10.5772/intechopen.91952
these pressures. Quality of life was formally assessed in some of these studies. The
majority reported an improvement across various domains such as physical and
social function.
To date there have been 6 randomised trials using anal bulking agents, with
more than 400 patients. Two trials compared a bulking agent with a sham or saline
injection. Siproudhis etal. in 2007 [15] compared a silicone biomaterial (PTQ )
with a normal saline injection (control) into the intersphincteric space. PTQ did
not demonstrate any appreciable clinical benefit when compared to the control.
The trial was however deemed to be too small to detect any differences in conti-
nence. Graf etal. in 2011 [16] compared the injection of dextranomer (NASHA
Dx) against sham injection (no substance injected). Continence was better in
the short term (6months) in the active intervention group, although interest-
ingly about 30% of patients in the control group had an improvement in their
continence. This same group, the NASHA Dx study group, published the results
of a prospective multicentre trial in 2014, showing that ‘submucosal injection
of NASHA Dx provided a significant improvement of FI symptoms in a major-
ity of patients and this effect was stable during the course of the follow-up and
maintained for 3 years.
A small study with 10 patients by Maeda etal. in 2008 [17] revealed significant
improvement at 6weeks postinjection using injection of Bulkamid and Permacol.
Continence decreased slightly in the Permacol group at 6months. However there
was no reported difference between the two agents. The numbers were too small
to detect a difference. Tjandra etal. in 2009 reported the results of a randomised
study comparing PTQ with carbon-coated beads (Durasphere) [14]. PTQ injection
was associated with better continence scores and quality of life and was safer than
Durasphere.
Tjandra etal. in 2004 reported the short-term benefits from ultrasound-guided
injection of silicone biomaterial (PTQ ) compared with digital guidance [13].
The follow-up for the majority of patients in studies was less than a median of
3years. A question on the term durability and effectiveness of these agents is there-
fore raised. The majority (97%) of patients were only followed up once or twice.
No long-term evidence on outcomes was available, and further conclusions were
not warranted from the available data. None of the studies reported patient evalu-
ation of outcomes, and thus it is difficult to gauge whether the improvement in the
continence scores matched the practical symptom and quality of life improvements
that mattered to the patients.
The majority of patients did not report any complications. The complications
described were mainly pain, anal bruising and leakage of injected material [11, 12].
Less common complications were anal ulceration and infection (local cellulitis and
abscess formation). There were two reported cases of local giant cell foreign body
reaction after injection of silicone (PTQ ) [18]. Durasphere has been associated with
skin rashes and arthritis. Skin patch testing is therefore recommended before using
this agent [14].
. The third phase: The implantable gatekeeper and Sphinkeeper
A relatively new and innovative development in anal bulking technology is
the Gatekeeper and Sphinkeeper (THD S.p.A., Correggio, Italy). The material
used is polyacrylonitrile (Hyexpan). Polyacrylonitrile is an inert, non-allergenic,
nondegradable material that is also non-immunogenic and noncarcinogenic. First
developed by Medtronic in Minneapolis, USA, it was originally used as an implant
in the oesophagogastric junction for the management of gastro-oesophageal reflux
disease.
Current Topics in Faecal Incontinence
The main indications for the use of the GK and SK are passive faecal inconti-
nence, secondary to IAS dysfunction or damage, where conservative measures or
injection of other bulking agents such as PTQ or Permacol has failed. However, the
use of GK and SK in patients with other causes of FI is being explored.
The following are contraindications to the use of the GK and SK.Similar con-
traindications have also been described by the product manufacturers of other anal
bulking agents:
• Perianal sepsis
• Inflammatory bowel diseases with anorectal involvement (Crohns disease,
ulcerative colitis)
• Anal, rectal or colon cancer undergoing active treatment
• Rectal bleeding of unknown or undiagnosed origin
• Rectal prolapse
• Uncontrolled blood coagulation disorders
• Pelvic radiotherapy
• Immunosuppression
• Pregnancy or planned pregnancy in the next 12months.
.. Surgical apparatus, procedure and technique
Whereas the anal bulking agents that were developed in phases 1 and 2 are
injected into or around the anal canal by means of a hypodermic syringe, the
Hyexpan prostheses are implanted into the intersphincteric space using a custom-
made gun (Figure ).
The difference between GK and SK lies in the size of the prostheses. The
dehydrated GK prostheses consist of thin solid cylinders, 22mm long and 2mm
in diameter. The success of this material depends on its hydrophilic properties.
Figure 3.
The gatekeeper gun, made of the dispenser that houses one prosthesis and the delivery system. The Sphinkeeper
delivery system and dispenser are similar but slightly larger.
Anal Injectable and Implantable Bulking Agents for Faecal Incontinence
DOI: http://dx.doi.org/10.5772/intechopen.91952
Within 48hours after implantation in the human tissue, the Hyexpan cylinders
absorb water to become thicker and shorter. The invitro maximum diameter is
6.5mm and the length is 17mm (Figure ). The volume of each individual implant
increases from approximately 70mm3 to 500mm3, a 750% increase. The implant
also becomes much softer in consistency. On the other hand, the SK prostheses in
the dehydrated state are thin, solid cylinders, 29mm long with a diameter of 3mm,
changing their size to a length of 23mm and a diameter of 7mm within 48h of
contact with fluids.
The technique of implantation of the GK and SK is identical. The operation is
performed under regional or general anaesthesia. Intravenous antibiotics are given
at induction. The author’s patients receive gentamicin 1.5mg/kg and metronidazole
500mg IV.The patient is placed in the lithotomy position. A strict sterile technique
is used. The IAS and intersphincteric groove are identified by the placement of an
anal retractor (e.g. Eisenhammer). The author’s preference is a THD surgy Mini-
light proctoscope, a self-illuminating anal and rectal retractor that gives a very good
view of the anorectum without causing trauma to the anal sphincter (Figure ). A
2mm incision is made in the perianal skin, 2cm from the anal verge (Figure ).
Having attached the dispenser to the delivery system, the needle is inserted
through the incision and tunnelled to the intersphincteric margin and introduced
into the intersphincteric space. The needle is then positioned so that the tip would
lie just beyond the dentate line. When the needle is identified in the correct posi-
tion, by direct vision and palpation and/or by endoanal ultrasound, the prosthesis is
released into the intersphincteric space (Figure ).
The steps may be repeated to insert up to 10 prostheses, equidistant from each
other. The GK has been originally described with the insertion of between 4 and
6 prostheses, whereas the SK has been described with the use of 10 prostheses.
The choice of inserting 4 as opposed to 6 or 10 prostheses is arbitrary. The use of
10 prostheses enables the formation of a circumferential or quasi-circumferential
intersphincteric ring, akin to an artificial anal sphincter. The prostheses self-fix in
the desired position, thereby preventing displacement and migration in the major-
ity of cases.
The wounds are closed with a single absorbable suture (Figure ). At the end of
procedure, EAUS imaging will show the location of all prostheses. The procedure
takes about 30 to 40minutes to complete and is done as a day case. Oral metronida-
zole 400mg tds is prescribed for 5days postoperatively. Oral laxatives such as lactu-
lose are prescribed to minimise the risk of constipation. The patients are advised
to avoid any anal trauma as well as anal intercourse for at least 72h after implant
insertion. The patients are followed up after 6weeks and 3months thereafter. The
material remains identifiable both by palpation and by endoanal ultrasonography in
the postoperative period (Figures  and ).
Figure 4.
(a) Shape of Hyexpan gatekeeper cylinder at insertion. (b) Fully expanded Hyexpan gatekeeper cylinder
following contact with water.
Current Topics in Faecal Incontinence

Figure 6.
Making an incision, 2cm away from the anal verge, at the 6 o’clock position.
Figure 5.
Palpating the IAS and the intersphincteric groove at the 6 o’clock position with a THD surgy mini-light
proctoscope in position.

Anal Injectable and Implantable Bulking Agents for Faecal Incontinence
DOI: http://dx.doi.org/10.5772/intechopen.91952
Figure 7.
The gatekeeper needle at the 9 o’clock position, with the endoanal ultrasound probe in place to determine
correct placement.
Figure 8.
Up to 10 equidistant circumferential perianal wounds, each closed with an absorbable suture (Monocryl 3/0).
Current Topics in Faecal Incontinence

.. Results
The first reported experience with the Gatekeeper was by Ratto etal. in 2011
[19]. This was a study with 14 patients. Eight had idiopathic FI, four had an IAS
defect, and two had combined IAS and EAS defects. The median follow-up was of
12months (ranging from 5 to 48months). The authors reported a clinically signifi-
cant improvement in continence in 13 patients, a sustained significant improvement
in the Wexner and Vaizey scores and in the SF36 and FIQOL scores. No complica-
tions have been reported.
The second study was a comparative retrospective study by Parello etal. in
2012 [20]. Seven patients who had the Gatekeeper implanted were compared to six
patients who underwent sacral nerve stimulation. The median follow-up was of
18months in the Gatekeeper group and 20months in the SNS group. The authors
reported a sustained improvement in the Wexner continence scores with both
modalities of treatment.
Fabiani etal. [21] used Gatekeeper for a group of patients affected by minor
faecal incontinence. Four out of seven patients complained of passive incontinence
prior to the procedure. After an average follow-up of 6months, 6 patients reported
a Wexner incontinence score under the value of 4, meaning that they rarely experi-
enced symptoms (0=perfect incontinence and 20=complete incontinence). Only
one patient who suffered mixed incontinence failed to respond.
Biondo etal. [22] concluded that Gatekeeper is a safe and effective procedure
in more than 50% of patients for at least a year after implantation. They found
that no patients had postoperative or long-term complications. Forty-eight per
cent of patients were classed as responders, and significant differences were found
between baseline mean Vaizey scores at 6months, 12months and last follow-up. At
long-term follow-up (2.7years), those patients that responded were found to have
maintained an improvement more than 50% of their baseline Vaizey score.
Figure 9.
Endoanal ultrasound scan (Aloka) at 6weeks following the implantation of six gatekeeper prostheses in a
72-year-old male with idiopathic passive faecal incontinence.

Anal Injectable and Implantable Bulking Agents for Faecal Incontinence
DOI: http://dx.doi.org/10.5772/intechopen.91952
In a multicentre study involving 54 patients and a clinical follow-up for a year,
Ratto etal. [23] noted that after Gatekeeper implantation, incontinence to gas,
liquid and solid stool improved significantly, soiling was reduced and the ability
to defer defaecation was enhanced. All faecal incontinence severity scores were
significantly reduced, and patients’ quality of life improved. At 12months, 30
patients (56 per cent) showed at least 75 per cent improvement in all faecal incon-
tinence parameters, and 7 (13 per cent) became fully continent. Dislodgement
of a few prostheses was reported, but this made no difference to postoperative
continence.
The author has carried out more than 40 GK procedures in a single centre
since 2012. The main indications were idiopathic FI and passive incontinence
following surgery (anal stretch for anal fissure and haemorrhoidectomy). All
patients had failed conservative management. There was a significant sustained
improvement in the median Vaizey scores. The median (range) Vaizey scores
improved from 16 (12–17) preoperatively to 5 (3–9), 4 (3–7), 4 (3–5), 4 (3–5),
5 (3–6) and 5 (3–6) at 6weeks and at 3, 6, 12, 24 and 36months, respectively
(p<0.01, Wilcoxon test). There was also an improvement in the Rockwood qual-
ity of life scores. The author reports no complications apart from minor pain that
is managed by paracetamol.
Publications on the Sphinkeeper are limited. Ratto etal. [24] treated 10 patients
with SK and followed them up for 3months. The study demonstrated that the SK,
with its larger prostheses than that of GK, is safe and effective. The Pelvic Floor
Society of the Association of Coloproctology of Great Britain and Ireland is cur-
rently collecting prospective data on the SK from multiple centres in the UK.
Figure 10.
Endoanal ultrasound scan (B&K) at 6weeks following the implantation of 10 Sphinkeeper prostheses in a
68-year-old female with passive faecal incontinence and previous episiotomy.
Current Topics in Faecal Incontinence

. Discussion
The development of anal injectable and implantable technology over the past
20years has taken great strides forwards. Starting with the pioneering efforts of
Shafik with autologous fat, more materials have been tried and used, the most
popular being collagen (Permacol) and silicone (PTQ or Bioplastique). These agents
were associated with variable and inconsistent results. Injections were frequently
repeated to maintain continence in the long term. The latest generation of anal
bulking agents is the implantable Hyexpan (Gatekeeper and Sphinkeeper). This
material fits the criteria for the ‘ideal’ bulking agent. It overcomes most limitations
of other bulking agents, and its use has shown very promising results.
The choice to implant the GK and SK prostheses into the intersphincteric
space of the anal canal plays a key role. This location potentially avoids extrusion
or migration of prostheses (different to what could happen if implanted into the
submucosa). Moreover, thanks to the rapid increase of their volume, the prostheses
self-fix and are unlikely to move after deployment.
The mechanism of action of anal bulking agents is a subject of debate. Most
ofthe resting anal pressure is the function of the IAS, with some contribution from
the EAS and anal cushions. Studies of faecal incontinence in patients who have
undergone a traditional Milligan-Morgan haemorrhoidectomy lend support to the
concept that anal cushions play an important part in the maintenance of the normal
mechanism of continence. It is thought that the mechanism of action of a bulking
agent injected into the submucosal space is an increase in the size of the natural anal
cushions. On the other hand, a bulking agent injected or implanted into the inter-
sphincteric space would bulk up the size of the anal sphincter. The end result would
be an improvement in the seal of the lumen of the anal canal at rest and potentially
an increase in resting anal pressure and in the length of the anal high pressure zone.
When the injection is placed adjacent to an identifiable IAS defect, a better degree
of anal canal sealing may be obtained through improvement in the configuration
and symmetry of the anal canal [7]. Ratto argues that GK and SK, being embed-
ded within the intersphincteric space, thereby pushing the EAS outwards and the
IAS inwards, ‘may improve sphincter contractility by increasing sarcomere length
as well as increase the length of the anal canal and provide a powerful “bulking
effect”’ [24].
It is acknowledged that more research is required in this field. Most studies are
case series with very few randomised trials. The Gatekeeper and Sphinkeeper, the
latest generation of anal bulking agents, show promising results. Whether these
results are maintained in the longer term or not awaits to be seen. The key factor
however remains that correct patient selection is extremely important to achieve
good results.
Larger series with longer follow-up and randomised controlled trials are there-
fore necessary. Further development on existing and emerging technology is also
warranted.

Anal Injectable and Implantable Bulking Agents for Faecal Incontinence
DOI: http://dx.doi.org/10.5772/intechopen.91952
Author details
JohnCamilleri-Brennan
Department of Surgery, Forth Valley Royal Hospital and the University of Glasgow
Medical School, Scotland, UK
*Address all correspondence to: johncbrennan@doctors.org.uk
© 2020 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms
of the Creative Commons Attribution License (http://creativecommons.org/licenses/
by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,
provided the original work is properly cited.

Current Topics in Faecal Incontinence
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... Faecal incontinence (FI), a highly prevalent condition, is the involuntary loss of intestinal contents due to an impaired ability to control the release of faeces/flatus [1][2][3]. Patients with FI suffer from a complex health problem causing considerable physical and social impairments leading to massive limitations in the quality of life (QoL) due to isolation, shame, and social rejection [4]. These stigmatising conditions adversely affect psychological well-being [3,[5][6][7]. ...
... Patients with FI suffer from a complex health problem causing considerable physical and social impairments leading to massive limitations in the quality of life (QoL) due to isolation, shame, and social rejection [4]. These stigmatising conditions adversely affect psychological well-being [3,[5][6][7]. The prevalence is estimated to 2-20% in the adult population and increases with age [6,7]. ...
... Injectable and implantable bulking agents can be considered as a minimally invasive option in FI management [16]. Injectable bulking agents, i.e. non-self-expandable prostheses, such as Solesta ® , Bulkamid ™ , PTQ ™ , Durasphere ® , and Permacol ™ , are injected around or into the anal canal [3,4]. The main clinical indication for injectable bulking agents is IAS disruption/dysfunction, causing passive FI [3]. ...
Article
Full-text available
Purpose The purpose of this systematic review is to evaluate whether self-expandable implantable vs non-self-expandable injectable bulking agents (second-line therapies) are equal/superior in terms of effectiveness (severity, quality of life [QoL]) and safety (adverse events) for faecal incontinence (FI). Methods A systematic review was conducted, and five databases were searched (Medline via Ovid, Embase, Cochrane Library, University of York Centre for Reviews and Dissemination, and International Network of Agencies for Health Technology database). In-/exclusion criteria were predefined according to the PICOS scheme. The Institute of Health Economics risk of bias (RoB) tool assessed studies' internal validity. According to the Grading of Recommendations, Assessment, Development and Evaluation approach, the strength of evidence for safety outcomes was rated. A qualitative synthesis of the evidence was used to analyse the data. Results The evidence consists of eight prospective single-arm, before-after studies (166 patients) fulfilling the inclusion criteria for assessing clinical effectiveness and safety of implantable bulking agents. FI severity statistically significantly improved in five of seven studies rated by the Cleveland Clinic FI Score and in three of five studies measured by the Vaizey score. Statistically significant improved disease-related QoL was found in one of five studies measured by the FI QoL Score and in one of two studies rated by the American Medical Systems score. Procedure-related adverse events occurred in 16 of 166 patients (i.e., intraoperative complications, anal discomfort and pain). Device-related adverse events occurred in 48 of 166 patients, including prostheses’ dislodgement and removed/extruded prostheses. Studies were judged with moderate/high RoB. The strength of evidence for safety was judged to be very low. Conclusion Implantable bulking agents might be an effective and safe minimally invasive option in FI treatment if conservative therapies fail. FI severity significantly improved, however, effects on QoL need to be explored in further studies. Due to the uncontrolled nature of the case series, comparative studies need to be awaited.
... They can be performed in an outpatient setting with a low risk of morbidity, therefore increasing in popularity [45]. The use of bulking agents results in less frequent episodes of fecal incontinence over time as they can guide the healing process [46]. Some examples of bulking agents include the silicon biomaterial (PTQ), carbon-coated microsphere (Durasphere ® ), and the dextranomer in stabilized hyaluronic acid, also known as NASHA Dx [47]. ...
... Cell therapy technologies have the potential to significantly alter the paradigm of treatment for patients with sphincter damage and for elderly patients. The conservative treatment options are generally not effective enough and the patient is referred further to undergo the different kinds of surgical treatments [46,69], which are often unsuitable or undesirable. Treatment using regenerative medicine products need to be entirely safe to differentiate them from other surgical interventions. ...
... The principle behind all these bulking agents is to provide the cushion effect (as provided by the anal cushion). So, patients with failed conservative management and a structurally intact but weak anal sphincter complex benefit from these agents [14][15][16]. ...
... Recent advances in these agents include using Polyacrylonitrile (Hyexpan) cylinders that inflate by absorbing water. The volume of these implants increases by up to 750%, which has shown much promise in providing continence to these patients [9,[14][15][16]. Another recent advance uses a magnetic anal sphincter augmentation device (FENIX MAS). ...
Chapter
Full-text available
The anatomy and physiology of the pelvic floor are complex. A thorough understanding of the anatomy is required to understand how we attain physiological continence. Fecal incontinence can be a life-altering condition that presents as an inability to maintain voluntary control of the passage of gas, liquid, or solid stool through the anus in patients who previously had control. The key to successfully managing a patient with fecal incontinence is to identify the underlying cause. There have been many prescribed procedures for patients requiring surgical correction to attain continence. However, the results are dismal for many patients. Recent advances have challenged these procedures with higher success rates.
... The operative technique has been described elsewhere [15]. Using a custom THD Gatekeeper™ Delivery System (THD SpA, Correggio, Italy) and dispenser the GK prostheses are placed in the intersphincteric space of the mid to upper anal canal. ...
Article
Full-text available
Background: Implantation of Gatekeeper™ prostheses presents an option for the treatment of passive faecal incontinence (FI). Whilst preliminary results are encouraging, long-term data regarding its sustained benefit are limited. The aim of this study was to assess and evaluate the long-term clinical function and quality of life of patients with passive faecal incontinence who were treated with Gatekeeper™ prostheses. Methods: This was a single centre, single surgeon retrospective study of prospectively collected clinical data in patients with FI treated between June 2012 and May 2019. Patients with passive FI with symptoms refractory to conservative treatment and endoanal ultrasonography showing intact or disrupted internal anal sphincter were included. Formal clinical and quality of life assessments were carried out using the St. Mark's Incontinence Score (SMIS) and Faecal Incontinence Quality of Life (FIQoL) questionnaires at baseline, 3 months, 6 months, 12 months and then annually. Endoanal ultrasonography was performed both before and after surgery. Results: Forty patients (14 males, 26 females) with a median age of 62.5 (range 33-80) years were treated with the Gatekeeper™ implant. The majority of patients (87.5%) received six implants. There were no peri or post-operative complications. Prosthesis migration was observed in 12.5% patients. The median follow-up duration was 5 years (interquartile range (IQR) 3.25-6.00 years). A sustained improvement in median SMIS and FIQoL scores from baseline to follow-up was noted. Significant differences were observed between the median baseline SMIS score and last follow-up score of 16.00 (IQR 15.00-16.75) to 7.00 (IQR 5.00-8.00) respectively (p < 0.001), a 56.25% decrease. The overall median FIQoL score showed a significant improvement from 7.95 (IQR 7.13-9.48) to 13.15 (IQR 12.00-13.98) (p < 0.001) a 65.40% increase. Conclusions: Gatekeeper™ implantation is a safe approach to treating passive FI and is minimally invasive, reproducible and has minimal complications. Long-term sustained clinical improvement is achievable beyond 5 years. Careful patient selection is paramount, as is consistency of technique and follow-up protocol.
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Introduction: A new artificial anal sphincter, SphinKeeper(TM), was devised with the aim to treat fecal incontinence (FI) by implanting specifically designed self-expandable prostheses into the intersphincteric space. Preliminary data concerning the procedure feasibility and prosthesis localization at 3 months are presented. Methods: SphinKeeper(TM) prostheses in the native state are dehydrated, thin, solid cylinder (length 29 mm, diameter 3 mm), changing their state (shorter-length 23 mm, thicker-diameter 7 mm-and softer, with shape memory) within 48 h of contact with fluids. In this study, 10 prostheses were implanted in each patient with FI under local anesthesia and under endoanal ultrasound (EAUS) guidance, into the upper-middle intersphincteric space of the anal canal by a specifically designed delivery system. EAUS was used postoperatively to assess prostheses dislocation. Results: Ten patients (5 females; median age 58 years, range 20-75) were enrolled and treated with SphinKeeper(TM) implantation. Median duration of procedure (performed by endoanal ultrasound guidance) was 40 min (range 30-45). Neither intraoperative nor postoperative complications were reported after a 3-month follow-up. In one patient, a partial dislocation of a single prosthesis was documented by EAUS, causing anal discomfort which resolved after 1 week. Conclusion: SphinKeeper(TM) can be safely implanted in patients with FI of different etiology. Implantation was well tolerated with no dislodgment of implants at 3-month follow-up.
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Background: A variety of therapeutic approaches are available for faecal incontinence. Implantation of Gatekeeper™ prostheses is a new promising option. The primary endpoint of this prospective observational multicentre study was to assess the clinical efficacy of Gatekeeper™ implantation in patients with faecal incontinence. Secondary endpoints included the assessment of patients' quality of life, and the feasibility and safety of implantation. Methods: Patients with faecal incontinence, with either intact sphincters or internal anal sphincter lesions extending for less than 60° of the anal circumference, were selected. Intersphincteric implantation of six prostheses was performed. At baseline, and 1, 3 and 12 months after implantation, the number of faecal incontinence episodes, Cleveland Clinic Faecal Incontinence, Vaizey and American Medical Systems, Faecal Incontinence Quality of Life Scale and Short Form 36 Health Survey scores were recorded. Endoanal ultrasonography was performed at baseline and follow-up. Results: Fifty-four patients were implanted. After Gatekeeper™ implantation, incontinence to gas, liquid and solid stool improved significantly, soiling was reduced, and ability to defer defaecation enhanced. All faecal incontinence severity scores were significantly reduced, and patients' quality of life improved. At 12 months, 30 patients (56 per cent) showed at least 75 per cent improvement in all faecal incontinence parameters, and seven (13 per cent) became fully continent. In three patients a single prosthesis was extruded during surgery, but was replaced immediately. After implantation, prosthesis dislodgement occurred in three patients; no replacement was required. Conclusion: Anal implantation of the Gatekeeper™ in patients with faecal incontinence was effective and safe. Clinical benefits were sustained at 1-year follow-up.
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Various injectable bulking agents have been used for the treatment of faecal incontinence (FI). However, encouraging early results are not maintained over time. This study aimed to assess short- and medium-term results of a new bulking agent for the treatment of FI. The Gatekeeper(™) prosthesis comprises a thin solid polyacrylonitrile cylinder that becomes thicker, shorter and softer within 24 h after implantation. Fourteen patients with FI underwent treatment with Gatekeeper(™) under local anaesthesia. Four prostheses were implanted in the intersphincteric space in each patient, under endoanal ultrasound guidance. Number of episodes of major FI, Cleveland Clinic FI score (CCFIS), Vaizey score, anorectal manometry, endoanal ultrasonography (EUS), health status and quality of life (Short Form 36 and Faecal Incontinence Quality of Life questionnaires) were assessed before and after treatment. Mean(s.d.) follow-up was 33·5(12·4) months. There were no complications. There was a significant decrease in major FI episodes from 7·1(7·4) per week at baseline to 1·4(4·0), 1·0(3·2) and 0·4(0·6) per week respectively at 1-month, 3-month and last follow-up (P = 0·002). CCFIS improved significantly from 12·7(3·3) to 4·1(3·0), 3·9(2·6) and 5·1(3·0) respectively (P < 0·001), and Vaizey score from 15·4(3·3) to 7·1(3·9), 4·7(3·0) and 6·9(5·0) respectively (P = 0·010). Soiling and ability to postpone defaecation improved significantly, and patients reported significant improvement in health status and quality of life. At follow-up, manometric parameters had not changed and EUS did not demonstrate any prosthesis dislocation. The Gatekeeper(™) anal implant seemed safe, reliable and effective. Initial clinical improvement was maintained over time, and follow-up data were encouraging.
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Since the 1990s, one of the methods used for treating fecal incontinence due to internal anal sphincter defects has been the injection of bulking agents. The aim of this paper is to report two cases of local giant cell foreign body reaction after injection of PTQ(TM) in humans. To the best of the authors' knowledge, this is the first report of an adverse immune response to silicone injection in humans.
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Background: The implantation of Gatekeeper ™ (GK) represents a new option for the treatment of fecal incontinence (FI). The aim of this study was to analyze the postoperative morbidity associated with GK and to determine its clinical efficacy after at least 1 year of follow-up. Methods: This was a multicenter, retrospective and longitudinal study of patients with FI who were treated with GK at our institutions between January 2010 and December 2015. Patients with FI without sphincter lesions or with sphincter injuries < 120° and with low anterior resection syndrome were included. Postoperative complications, long-term adverse effects and migration were recorded. FI severity was assessed using the Vaizey score. Patients were classified as responders or non-responders according to the improvement of the Vaizey score (≥ than 50 and < 50%, respectively) during the first 6 months after implantation. Results: Forty-nine consecutive patients treated with GK between 2010 and 2015 were included (11 males and 38 females, mean age 63.3 years, SD 13.5). No postoperative and long-term complications were observed. Prosthesis migration was observed in 51% of patients. Twenty-three patients (48%) were classified as responders and 25 (52%) as non-responders. The mean Vaizey score at baseline, 6, 12 months and last visit post-surgery in the responder group was, respectively, 13.3 (SD 3.8), 4.3 (SD 2.1), 4.2 (SD 3.6) and 5.7 (SD 5.3). Significant differences were observed between the mean baseline Vaizey score and the mean 6, 12 and last follow-up Vaizey score values (p < 0.001). In long-term follow-up (2.7 years (SD 1.1)), responders maintained an improvement of more than 50% of the baseline Vaizey score. In the non-responder group the mean number of migrated prostheses was higher than in the responder group (2.4 SD 2.5 vs. 1.0 SD 1.6; p = 0.040). Conclusions: GK is a safe and effective procedure in more than 50% of the patients for at least 1 year after the implantation.
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Fecal incontinence is a challenging condition of diverse etiology and devastating psychosocial impact. Multiple mechanisms may be involved in its pathophysiology, such as altered stool consistency and delivery of contents to the rectum, abnormal rectal capacity or compliance, decreased anorectal sensation, and pelvic floor or anal sphincter dysfunction. A detailed clinical history and physical examination are essential. Anorectal manometry, pudendal nerve latency studies, and electromyography are part of the standard primary evaluation. The evaluation of idiopathic fecal incontinence may require tests such as cinedefecography, spinal latencies, and anal mucosal electrosensitivity. These tests permit both objective assessment and focused therapy. Appropriate treatment options include biofeedback and sphincteroplasty. Biofeedback has resulted in 90 percent reduction in episodes of incontinence in over 60 percent of patients. Overlapping anterior sphincteroplasty has been associated with good to excellent results in 70 to 90 percent of patients. The common denominator between the medical and surgical treatment groups is the necessity of pretreatment physiologic assessment. It is the results of these tests that permit optimal therapeutic assignment. For example, pudendal nerve terminal motor latencies (PNTML) are the most important predictor factor of functional outcome. However, even the most experienced examiner's digit cannot assess PNTML. In the absence of pudendal neuropathy, sphincteroplasty is an excellent option. If neuropathy exists, however, then postanal or total pelvic floor repair remain viable surgical options for the treatment of idiopathic fecal incontinence. In the absence of an adequate sphincter muscle, encirclement procedures using synthetic materials or muscle transfer techniques might be considered. Implantation of a stimulating electrode into the gracilis neosphincter and artificial sphincter implantation are other valid alternatives- The final therapeutic option is fecal diversion. This article reviews the current status of the etiology and incidence of incontinence as well as the evaluation and treatment of this disabling condition.
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The aim of this review was to assess and evaluate reports of studies on the efficacy of anal bulking agents used in the treatment of faecal incontinence. A systematic review of the literature was carried out to identify studies that have reported on the use of anal bulking agents. A variety of biomaterials have been employed for anal bulking. These include autologous fat, bovine glutaraldehyde cross-linked collagen, carbon-coated zirconium oxide beads, dextranomer microspheres in a gel, hydrogel cross-linked with polyacrylamide, polydimethylsiloxane elastomer in a gel, porcine dermal collagen and synthetic calcium hydroxylapatitie ceramic microspheres. Although the ideal site of injection (submucosal or intramuscular) and the mechanism of action remain the subject of debate, most published studies report a significant improvement in continence in at least 50% of subjects with mild to moderate symptoms with little or no associated morbidity.We concluded that anal bulking agents may be used to alleviate symptoms of faecal seepage and soilage.
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Both injectable silicone biomaterial (PTQ) and pyrolytic carbon-coated beads (Durasphere) have been shown to be effective in treating passive faecal incontinence due to internal sphincter dysfunction. This is a randomized study to evaluate their relative safety and efficacy. Forty patients (mean age 59.5 years vs 58.9 years) were randomized to have inter-sphincteric injection of PTQ or submucosal injection of Durasphere. Patients were assessed with anorectal physiology, endoanal ultrasound, a validated incontinence score and quality of life questionnaires. In the Durasphere group, complications included rectal pain (5%), erosion through rectal mucosa (10%), and type III hypersensitivity reaction (5%). No complications occurred in the PTQ group. Compared with PTQ, Durasphere group has a more rapid action, with improved continence at 2 weeks after injection. In both groups, faecal continence significantly improved 6 weeks after injection, and continued to improve significantly up to 6 months in both groups (P < 0.0001). At 6 weeks, 6 and 12 months after injection, significantly more PTQ patients achieved greater than 50% improvement in Wexner's continence score than Durasphere patients (respectively, P = 0.01; P < 0.0001; P = 0.001). There was a significant improvement in faecal incontinence quality of life scale and the 12-month physical health scale of Short Form-12 health survey in the PTQ group but not in the Durasphere group. In patients with internal sphincter dysfunction, injectable silicone biomaterial was safer and more effective than Durasphere.
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Injection of a bulking agent in the anal canal is an increasingly used treatment for faecal incontinence, but efficacy has not been shown in a controlled trial. We aimed to assess the efficacy of injection of dextranomer in stabilised hyaluronic acid (NASHA Dx) for treatment of faecal incontinence. In this randomised, double-blind, sham-controlled trial, patients aged 18-75 years from centres in USA and Europe were randomly assigned (2:1) to receive either transanal submucosal injections of NASHA Dx or sham injections. Randomisation was stratified by sex and region in blocks of six, and managed with a computer generated, real-time, web-based system. Patients and investigators were masked to assignment for 6 months when the effect on severity of faecal incontinence and quality of life was assessed with a 2-week diary and clinical assessments. The primary endpoint was response to treatment based on the number of incontinence episodes. A response to treatment was defined as a reduction in number of episodes by 50% or more. Patients in the active treatment group are still being followed up. This trial was registered with ClinicalTrials.gov, number NCT00605826. 278 patients were screened for inclusion, of whom 206 were randomised assigned to receive NASHA Dx (n=136) or sham treatment (n=70). 71 patients who received NASHA Dx (52%) had a 50% or more reduction in the number of incontinence episode, compared with 22 patients who received sham treatment (31%; odds ratio 2·36, 95% CI 1·24-4·47, p=0·0089). We recorded 128 treatment-related adverse events, of which two were serious (1 rectal abscess and 1 prostatic abscess). Anal injection of NASHA Dx is an effective treatment for faecal incontinence. A refinement of selection criteria for patients, optimum injected dose, ideal site of injection, and long-term results might further increase the acceptance of this minimally invasive treatment. Q-Med AB.