Tissue Reaction to Vicryl Plus and Vicryl in Cats after Elective
Ovariectomy
A Comparative Double Blinded Randomized Study
MAAIKE STAPPER
Supervisors: Drs. BOUVIEN A.W. BROCKS and Prof. Dr. JOLLE KIRPENSTEIJN, Diplomate ACVS & ECVS
Surgeon: Drs A.F. Heijkants
Abstract
Objective—To evaluate tissue reaction to Vicryl Plus in cats
Study Design—Double-blinded, prospective, randomized clinical trial.
Animals—Cats (n=22) who were submitted for elective ovariectomy
Methods—Elective ovariectomy was performed by one single surgeon via a standardized abdominal
incision, which was sutured in 3 layers with either Vicryl or Vicryl Plus. Wounds were evaluated
during recovery and at four time intervals for pain, subdermal swelling of the wound edges, redness,
crusting and subdermal thickness by one single investigator.
Results—Nineteen animals met the inclusion criteria. In eight cats Vicryl was used and in eleven cats
Vicryl Plus. There was more subdermal swelling in the Vicryl group after 8 to 9 days and after 16 to
17 days (p<0.05). There was no significant difference in the other parameters.
Conclusion—The addition of triclosan to the coating of Vicryl may have a reducing effect in tissue
reaction to suture material in wound healing process in cats.
Clinical Relevance—Less tissue reaction may possibly occur in cats after wound closure with Vicryl
Plus compared to closure with Vicryl. Further research is warranted.
Introduction
The healing process of a wound or
incision involves well-regulated cellular and
molecular events that start at the moment of
tissue damage and ends weeks or months later
in the formation of completely reintegrated
tissue. After 24 to 48 hours the wound is sealed
with a fibrin scab and admission of bacteria is
prevented. Fleck 2007 Sutures are used frequently
to approximate tissue and promote tissue
healing. With a good apposition of wound
edges wound healing will be facilitated. To
choose which suture is best qualified the
following has to be taken into account: type of
tissue, implant location, size of the wound,
expected healing time, expected mechanical
loads, and required suture configuration.
Wound closure should provide adequate tensile
strength to the tissue until the wound is healed,
permit normal healing, and remain secure even
in the presence of an infection. Sahlin; 1993 Suture
materials act as a foreign body in the wound
tissue and cause an inflammatory and
immunological reaction. It affects host defense
against infections, while an infection of the
wound will prolong the inflammatory process
and delay the healing process. Impaired wound
healing is caused most often by infections Storch,
Perry, 2002, Fick; 2005, which can lead to weaker scars.
Katz; 1981,Chu; 1984, Eugster; 2004,Gabrielli; 2005, Edmiston; 2006.
The process of wound healing is wellregulated and consists of a cellular and a
molecular component. In the wound healing
process injured tissue is repaired. The repair
1
Tissue Reaction to Vicryl Plus and Vicryl in Cats after Elective Ovariectomy
2
begins at the moment tissue is traumatized and
can take weeks to months for completely
reintegrated tissue is formed. This results in
regeneration of the tissue’s cell lining and
reorganization
of
mesodermal
tissue
derivatives into a scar. Wound healing can be
divided in four phases (lag, inflammation,
proliferation and maturation and remodeling).
These phases are defined by the cell types that
are present at the healing process. Storch, Perry,
2002, Fick; 2005 Surgical wounds are often closed
with sutures to reduce healing time. The
inflammatory phase is shortened compared to
open wound healing due to minimal
debridement. Johnston 1990.
The inflammatory reaction to suture
material is more severe in absorbable sutures
than
in
nonabsorbable
sutures,
in
multifilamentous
sutures
compared
to
monofilamentous sutures, nonflexible sutures
compared to flexible sutures and superficial
dermal implantation compared to deep dermal
implantation of sutures. Niessen, 1997 The solubility
and physical structure of suture material
influences the severity of the inflammatory
reaction. Compared to natural absorbable
sutures synthetic absorbable sutures cause less
tissue reaction, have greater tensile strength
and are absorbed more predictably. Austin, 1995,
Kirpensteijn; 1997 An advantage of absorbable suture
material is that they do not require removal.
Due to their degradation by hydrolysis,
enzymatic digestion or phagocytosis there will
be a varying degree of tissue response. Yaltrik; 2003
Coated polyglactin 910 (Vicryl=V) is
the suture that is used most often in general
practice, because it has physical and functional
properties that meet the specific needs of
wound closure. V was first introduced in 1974,
and it is composed of a copolymer of lactide
and glycolide, coated with polyglactic acid and
calcium stearate. Storch, Scalzo, 2002 It is a
multifilament suture that is used frequently all
over the world in human and veterinary
M. Stapper
medicine. Ford; 2005 It is characterized by great
tensile strength, little tissue reaction, complete
absorption and low capillarity. Absorption
begins on day 40 and is completed on day 70.
Gammelgaard; 2001
It has been mentioned that some cats
are more sensitive to V by a local
hyperreactivity of the wound. It is an individual
reaction, but is regularly observed in the
veterinary
general
practice
(personal
communication Ethicon, Johnson & Johnson).
Also in a retrospective study an adverse
reaction in 9 out of 27 cats was seen, where V
was used for all layers (including linea alba).
Freeman 1987 Swelling beneath the incision line can
be caused by inflammation and proliferation of
fibrous tissue which occurs 5-7 days after feline
abdominal incision. This reaction is often
ascribed to the suture material used. An
increase of the inflammatory reaction along the
abdominal incision in the feline patient may
result from the type of suture material, an
individual allergic reaction to suture material,
unsuccessfully
closed
dead
space,
disproportionate tissue handling, excessive
tight sutures, or differences in feline tissue.
Automutilation due to daily grooming can also
enhance inflammation. Freeman; 1987
When V is compared to polydioxanon or
gut in feline patients with abdominal incisions
prospectively, there is no significant difference
between tissue reactions. Only incisional
swelling at first day postoperatively could be
due to tissue handling during surgery. Freeman;
1987 In humans significant more hypertrophic
scarring has been reported in comparison to
polydioxanon. Hohenleutner; 2000 Old age, length of
wound (> 3 cm) and experience level of surgeon
are predisposed to be a human risk factor.
Gabrielli; 2005 In dogs comparison of V with
polyglecaprone (Monocryl ) resulted in more
swelling and redness for the group with V,
which resulted in significant more tissue
reaction on histological biopsy after 7 days. It
Tissue Reaction to Vicryl Plus and Vicryl in Cats after Elective Ovariectomy
3
was hypothesized that this reaction was due to
the multifilamentous nature of V, which is
known to cause more friction and therefore
more redness and swelling postoperatively.
Kirpensteijn; 1997
Coatings are frequently added to a
suture to influence the handling properties and
security of the knot. Coatings that are water
soluble usually have chemical properties that
are similar to those of the suture material, and
are broken down by hydrolysis. The main
characteristics of sutures are: physical and
mechanical
properties,
biocompatibility,
biodegradation, and handling. The possibility to
add an antimicrobial component to the coating
of a suture or other medical device has been
gaining attention recently as it can play an
important role in preventing bacterial growth.
Storch, Scalzo 2002 Triclosan is such an addition to
the coating solution of V. For this reason Vicryl
Plus (VP), coated polyglactin 910 with
triclosan, was introduceda. It overcomes the
risk of a suture being a risk factor and prevents
wound contamination during the first 10 days
after surgery in which 90% of the wound
infections develop. Fleck; 2007
Triclosan,
2,2,4’-trichloro-2’-hydroxydiphenyl ether (C12H17CL3O2), is a nonionic, offwhite, odorless, and tasteless powder. It is a
synthetic nonionic broad-spectrum antimicrobial agent (effective against bacteria,
fungi and some viruses), that has been used for
over 30 years in personal care products. It is
significant more effective against gram-positive
species than it is against gram-negative species
Jones; 2000, Gilbert; 2002, Barbolt; 2002, Ford; 2005, Edmiston; 2006
Gómez-Alonso; 2007, Fleck; 2007,
Triclosan has shown to
be useful against methicillin-resistant bacteria
in topical infections and against most of the
device related pathogens. Triclosan has been
used successfully by health care facilities in
outbreaks to aid in the reduction of nosocomial
infections of antibiotic resistant bacteria. It
helped with bringing the MRSA outbreaks to a
halt. Jones; 2000, Rothenburger; 2002 ,Storch, Rothenburger, 2004
VP shows antimicrobial activity in vitro against
S. aureus and S. epidermidis, which was not
observed in V. Rothenburger 2002. Long term use of
triclosan in products for the skin or oral use did
not result in selection of a triclosan-resistant
population. The use of triclosan within the
suture is a short term application and it is
unlikely it would cause a triclosan-resistant
population. Jones; 2000,Gilbert; 2002 Triclosan binds to
albumin in the serum and is present as the
sulfate or the glucuronide conjugate. Only a
small amount of free triclosan is detected in the
blood. It does not accumulate and due to its
low exposure levels and the rapid metabolism
and excretion of triclosan, there is no toxicity
expected for the use of V coated with triclosan.
Barbolt; 2002 Triclosan is relatively nontoxic, has no
carcinogenic potential, is not mutagenic, has no
adverse effects on reproduction performance,
no potential teratologic effect, no impact on
postnatal development and has little or no
contact sensitization hazard for patients. Jones;
2000 Barbolt; 2002 The primary dermal index was
determined to be greater than 5.0 for all test
materials at all concentrations, indicating that
products containing as much as 1.0% triclosan
do not irritate the skin. Investigations have
shown that triclosan-containing skin care
products do not exhibit skin sensitizing or
photosensitizing effects. Jones; 2000
The in vitro studies pointed out that
triclosan used in the suture material does not
result in cell lysis or toxicity, is not cytotoxic,
has no irritant potential and is not a chemical
pyrogen. The tissue reaction, minimal to mild
granulomatous inflammation and fibrosis
infiltrating surrounding the suture, is
comparable to the tissue reaction that is
observed for V. It is the reaction that is often
seen as a response to a foreign body. The
healing process and tissue reaction to coated V
with triclosan is comparable with the traditional
suture with a similar absorption rate of 70 days.
M. Stapper
Vicryl by Ethicon
Vicryl Plus by Ethicon
Tissue Reaction to Vicryl Plus and Vicryl in Cats after Elective Ovariectomy
4
Barbolt; 2002
Zones of inhibition were still observed
after repeated inoculation of knotted VP and
after passing VP repeatedly through fascia and
subcutaneous tissue. Rothenburg, 2002, Edminston, 2006
After tissue passing and by aqueous diffusion
there is some removal of triclosan from the
sutures, but there is still enough triclosan left to
produce a measurable antimicrobial effect in
vitro. It is likely that, although there is an initial
loss of triclosan from the surface of the coating,
more triclosan remains within the suture
interstices of the braids. Knots in the suture do
not impair the antimicrobial affectivity of the
coating. Rothenburger; 2002 Treatment of sutures by
physical or chemical means can change the
handling and physical properties of the suture.
For this reason, VP has been tested extensively
to be sure that the performances were
comparable with traditional V. Storch, Scalzo 2002
Clinical performance in human wound healing
resulted in significantly less pain in the triclosan
group the first day postoperatively which was
possibly due to diminished inflammatory
reaction
and
reduction
of
bacterial
colonization. No significant difference was
observed between V or VP in wound healing,
tissue edema, tissue reaction or bursting
strength. The overall intraoperative handling
was comparable and favorable for both sutures.
Ford; 2005
No statistically significant difference
between VP and V was found with respect to:
ease of passage trough tissue, first throw knot
holding, knot tie down smoothness, and knot
security. In an experimental model with rats
tissue reaction for VP was generally minimal to
mild and comparable to V with a similar healing
process. Storch, Scalzo, 2002 In experimental infection
of rat wounds with orthopedic implants it can
significantly reduce colonization with less
polymorph nuclear cells on histology. Marco; 2004
In an experimental porcine model in case of
infection healing mediators were significantly
normalized by use of VP compared to V. In
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absence of an infection VP behaved similar to
V. Gómez-Alonso; 2007 In an experimental model with
guinea pigs VP had significant less
haemorrhagic subcutaneous tissue response
with less purulent exudates than V. Storch,
Rothenburger et al, 2004 No difference in impact on
wound healing was found based on
biomechanical testing and histopathologic
evaluation of the inflammatory responses and
collagen deposition in wound repair. Storch, Perry,
2002
Hypothesis
To avoid the suture material as a risk
factor for infection a new suture material is
introduced: Vicryl Plus (Polyglactin 910
coated with Triclosan). Ford; 2005, Edmistonl; 2006, GómezAlonso; 2007, Fleck; 2007 Triclosan is an antibacterial
component that should decrease the risk of a
wound infection after surgery. VP showed to
normalize infection healing mediators and
might have a beneficial effect on wound
healing. We hypothesized that coating with
triclosan in Vicryl Plus might lead to less
hypersensitivity reactions in cats then are
observed with traditional Vicryl. In this study
local tissue reaction of Vicryl Plus was
compared with Vicryl in cats after elective
ovariectomy.
Materials and Methods
Study design
Data were systematically collected from
22 cats that were admitted to the veterinary
clinic ‘De Langstraat’ at Waalwijk for an elective
ovariectomy. The operations were performed
between September and November 2008. The
animals were randomly assigned to one of the
two suture materials. A single experienced
general practice surgeon (AH) performed all
surgeries and all clinical examinations were
performed and recorded by one person (MS).
The design of the study is a prospective,
randomized, double-blinded, clinical trial,
Tissue Reaction to Vicryl Plus and Vicryl in Cats after Elective Ovariectomy
5
where coated polyglactin 910 was used as
control and coated polyglactin 910 with
triclosan of identical size was used as test
material.
Suture material
The ovaries of all the animals were
ligated with coated polyglactin 910 (Vicryl).
The suture materials used during this study
were 3-0 coated polyglactin (Vicryl) or coated
polyglactin 910 suture material with triclosan
(Vicryl Plus) for closure of the surgical wound.
All suture materials had a reversed cutting 3-8
swaged-on taper point type needle.
Animals
During this study 22 animals were
admitted for elective ovariectomy. The animals
that participated were cats from the local
animal shelter or cats that were privatelyowned patients. The owners of the privatelyowned cats consented to participation in the
study.
Surgery
The patients were admitted for an
elective ovariectomy. Pre-operative evaluation
was performed and data were collected. The
pre-operative
evaluation
consisted
of
identifying the patient, age (for shelter cats
estimated), bodyweight and body condition
score, performing a preanesthetic physical
examination
(respiration,
circulation,
temperature, capillary refill time, lymph nodes,
skin/hair/horn structures) Rijnberk, 2005 and
auscultation of the lungs and heart.
The anesthetic protocol consisted of
sedation with 50 g/kg medetomidine
hydrochloride (Domitor) or 40 g/kg
dexmedetomidine
hydrochloride
(Dexdomitor) intramuscular and 5 mg/kg
ketamine
hydrochloride
(Ketalin)
intramuscular. Maintenance was achieved by
M. Stapper
inhalation anesthesia with isoflurane (Isoflo)
with oxygen by endotracheal tube. Analgesia
consists of 0.2 mg/kg meloxicam (Metacam)
once subcutanously admitted pre-operatively.
Antimicrobial prophylaxis consists of 20 mg/kg
ampicillin
anhydrate
(Albipen
LA)
subcutaneous.
All surgeries were performed by one
experienced general practice surgeon (AH).
Using aseptic technique, a standardized 4 cm
abdominal incision was made with a # 10 BardParker blade. The incision was deepened with
Metzenbaum scissors. Care was taken not to
undermine the subcutaneous fat. The linea alba
was incised with a scalpel. The ovaria were
retracted and ligated with coated polyglactin
910. The abdominal incision was closed with
the assigned suture material in 3 layers: linea
alba simple continuous pattern with three
throws at the beginning and the end,
subcutaneous with a continuous horizontal
mattress pattern with three throws at the
beginning and the end and subdermal layer
with a continuous horizontal mattress pattern
with three throws at the beginning and the end
and. Surgeon and investigator were blinded for
the assigned suture material. The remainder of
the used suture material was measured, to
determine the total amount of used suture
material.
The time needed for preparation, the
operation, the suture placement, the total
anesthetic time, and the recovery time were
recorded. Postoperative 100 g/kg atipamezole
(Antisedan)
was
administered
for
antagonizing (dex)medetomidine.
Wound evaluation
Wound control was performed by one
investigator (MS) at all times. The wounds of
the shelter and privately owned cats were
routinely checked postoperatively after one
hour (R), 8 or 9 days (C2), 16 or 17 days (C3)
and 29 or 30 days (C4). Additionally the shelter
Tissue Reaction to Vicryl Plus and Vicryl in Cats after Elective Ovariectomy
6
owned cats were controlled on 1-2 days (C1). R
was for having a zero measurement. C1 was for
observing the short-term reaction to the suture
used. C2 and C3 were for following the wound
healing and C4 was to determine how the
wound was after the suture lost all its strength.
All operations were performed on Thursday or
Wednesday and all controls were performed on
Thursday.
The abdominal incision wound was
checked and graded following a standard
protocol. Redness was scored from 0-2 (0
similar as preoperative, 1 minimal redness, 2
severe redness), swelling was measured by a
standardized caliper at 3 points: lateral at the
suture knot and the midline, and the height
Pain was scored by observing the animal and
palpating the wound (Visual Analogue Scoring
described by Slingsby et al and Väisänen et al)
Slingsby; 2001, Väisänen; 2007. The amount of crustae
was scored from 0-2 (0 no crusting, 1 minimal
crusting, 2 severe crusting) and subdermal
thickness observed during the wound palpation
and scored from 0-2 (0 no subdermal thickness,
1 minimal subdermal thickness mainly at the
suture knot, 2 subdermal thickness along the
whole incision line).
In addition to this, the clinical condition
was described with special attention to pain,
itching, behavior, automutilation and appetite.
A digital photo was made from every wound at
every control moment.
Inclusion criteria
The animals that were admitted to this
study had to meet the inclusion criteria. The
inclusion criteria are: ASA 1 score and no
systemic illness or usage of pharmaceutical
preparations that may interfere with wound
healing. Animals had to be younger than 10
years old and have a maximum Purina body
score purina of 7. Animals could not have been
operated by an abdominal midline incision.
M. Stapper
Animals that did not meet the inclusion criteria
were excluded from the study.
Data collection
Every cat that was admitted to this
study was given a unique number. All data
concerning this patient were collected during
preoperative evaluation; surgery and wound
evaluation were filled in at this data sheet and
processed digitally.
Statistical methods
All statistical analysis were performed
using computer software (SPSS 15.0 Command
Syntax Reference 2006, SPSS Inc., Chicago Ill.
for Windows®). Descriptive statistics were
performed on all data. The Mann-Whitney U
test was used to compare the suture materials.
The Spearman’s rho test was used to find
correlations between ordinal values. The
Pearson test was used to find correlations
between scale values. A p value < 0.05 was
considered significant.
Results
Patient population
Twenty-two animals were adimitted for
elective ovariectomy. Two animals had a
previous abdominal midline incision and were
excluded from the study. Twenty animals met
the inclusion criteria. From these animals 11
were privately owned and the animal shelter
admitted 11. For the first control (C1), 10
animals were observed. At the second control
(C2), 20 animals were observed. At the third
control (C3) 17 animals were observed and at
the fourth control (C4) 19 animals were
observed.
One animal had an incisional hernia of
the linea alba (V). The animal had been
vomiting excessively the first day after surgery
and was not confined. It was corrected
operatively on day 8 after surgery and the
animal was excluded from the study.
Tissue Reaction to Vicryl Plus and Vicryl in Cats after Elective Ovariectomy
7
From the animals that were included,
eight animals were assigned to the group with
V and eleven animals to VP (Table 1). In the VP
group there was longer preparation time
(p=0.03). This was due to 3 cats that were
premedicated simultaneously with other cats
but were last in order to be operated. The
operation time of these three cats was not
longer than in other cats. The groups were
comparable for all the other variables.
There was one animal that had enlarged
mandibular lymph nodes and louder than
normal breath sounds on auscultation. This
animal was still included in the study, because
it met the inclusion criteria, and had no
influence on correlations in statistic analysis.
Nine animals had an elevated respiration
frequency before operation. Two animals had a
hernia umbilicalis that was corrected during
surgery.
There was one animal (VP) that received
antibiotics (amoxoral) for 7 days from the 7th till
the 14th day after surgery. The wound of this
cat was swollen subdermally and an infection of
the abdominal muscles was suspected by the
attending veterinarian.
Subdermal thickness
The results are shown in Figure 1. For R,
C1 and C4 there was no significant difference
between the groups. For C2 and C3 there was a
significant difference in the subdermal
thickness (C2: p=0.026, C3: p=0.006). The
thickness was more severe in the V group
compared to the VP group. In Figure 5-8 there
are wounds visible from 2 cats at C2 and C4.
The difference in subdermal thickness is
evident.
Crusting
The results for crusting of the wound
are listed in Figure 2. On every control the
amount of crustae was observed and scored
from 0-2. There was no significant difference in
M. Stapper
the amount of crustae between the two suture
materials.
Pain
The results are listed in Figure 3. The
pain at every control was scored by using the
Visual Analogue Scale. There was no significant
difference between the two materials in VAS
score.
Redness
There were 3 animals that showed
redness of the wound during the study. Two of
them occurred at C2 (one minimal and one
severe) and the third animal showed minimal
redness at C3. The wounds were not painful
and there was no suspicion of an infection.
There was no significant difference in redness
between the two materials used.
Swelling of the wound edges
The results are shown in Figure 4. The
wound edges were measured at every control.
The swelling of the controls was compared to
the swelling at the recovery. The differences
were calculated and used for the comparison.
There was no significant difference in swelling
of the wound edges between the two materials
used at any control time.
Complications
On the first control there were 4
animals that were licking their wounds. Three
of them were in the V group and one in the VP
group. The difference was not significant
(p>0.05). In the V group there was one animal
that had a herniation of the linea alba. This
animal was excluded from the study. One
animal had a suspected infection of the
abdominal muscles. The attending veterinarian
did not take a sample for bacterial culture and
prescribed antibiotics (amoxoral) for 7 days. In
this way it was no longer possible to attain a
sample for bacterial culture when the cat was
Tissue Reaction to Vicryl Plus and Vicryl in Cats after Elective Ovariectomy
8
observed on C2. After treatment with amoxoral
the subdermal swelling was dissolved.
Discussion
The inflammatory phase may progress
into excessive reaction after wound closure
with V in hypersensitive cats. These cats have a
more severe reaction to the suture after 5 to 7
days, which can result in swelling of the wound
edges, and a thickness under the incision line.
Freeman, 1987 In this study there was a difference in
the subdermal swelling observed. The
subdermal swelling was observed more severe
in wounds closed with V than wounds closed
with VP after 8 to 9 days and after 15 to 16 days
(p< 0.05). This might indicate that with the
addition of triclosan less cats show an excessive
reaction to VP than they show to V. The
difference in tissue reaction is in contrast with
earlier studies in humans and guinea pigs,
reported that the tissue reaction to VP is
comparable with V. Storz, Perry 2002, Ford 2005, GomezAlonso 2007 Our findings might be caused by the
sensitivity for V observed in cats. Freeman 1987
In our study there was no significant
difference between the two materials in
redness or swelling of the wound edges or in
the amount of crustae visible. The
hypersensitive reaction mentioned and
observed in this study does only happen in cats
(personal communication Ethicon, Johnson &
Johnson, Freeman 1987). This reaction to VP is less
severe based on the subdermal thickness
observed, which explains the difference
between V and VP in this study. However
histologic confirmation of this subjective finding
is necessary to determine what the subdermal
thickness triggers. In our clinical study setting
this was not obtained. Further research is
necessary to fully understand the reaction.
In our study there was not a significant
difference in pain between the two suture
material groups. This is in contrast with the
results of Ford et al., who observed in humans
M. Stapper
significantly less pain on day one in the VP
group by individual self evaluation. Ford; 2005
Scoring pain in animals is very difficult because
of the interpreter’s subjectivity and the
tendency of animals to hide pain.Hardie,2000,
Robertson, 2005 Although the VAS system showed to
be a valuable tool for pain scoring in animals
Slingsby, 2001, Väisãnen 2007 it is possible that it isn’t
accurate enough to find a small difference. On
the other hand our study may lack statistical
power in comparison to Ford’s study.
Althought there was a longer
preparation time in the VP group there was not
a correlation between the preparation time and
suture material or preparation time and
subdermal thickness observed. The preparation
time was longer in the VP group due to 3 cats
that were premedicated simultaneously with
other cats but were the last in order to be
operated. In this way there was a longer
preparation time for these cats which resulted
in a longer anesthetic time. The operating time
of these animals was comparable with the
other cats.
Postoperative complications were seen
in 2 cats (10.0%): one suspected surgical site
infection after 7 days (VP) (5,0%) and one
incisional hernia after several days (V) (5,0%).
The complication rate of 11% is higher than one
would expect. The infection rate observed in
cats and dogs is 3.0% The infection rate in this
study is higher than the infection rate in the
study of Eugster et al. Eugster 2004 Vasseur et al.
published in 1988 an overall infection rate of
5.1% in cats and dogs. This is comparable to the
infection rate observed in our study. Vassuer, 1988
Skin sutures were placed subcuticular to avoid
licking and auto mutilation. Another advantage
is that migration along the suture track does
not happen as often as it is seen with
cutaneous suture placement. In this way the
risk of a suture track infection is reduced. Fick;
2005 Even with the subcuticular placement of the
sutures there is one suspected SSI. After
Tissue Reaction to Vicryl Plus and Vicryl in Cats after Elective Ovariectomy
9
prescription of amoxoral for seven days the
subdermal swelling disappeared. We can not be
sure this was because the animal received
antibiotics or that it might have dissolved
anyway. A prolonged anesthetic time is a risk
factor for developing a SSI. Eugster ; 2004 The cat
that developed the suspected SSI was one of
the animals that had a prolonged preparation
time. Due to this the anesthetic time was also
prolonged. An increased anesthetic time is a
risk factor for developing a SSI. Eugster 2004 This
might have increased the risk in developing the
adverse reaction. Important sources for
postoperative infections are skin pathogens.
Gilbert, 2002 Triclosan helps with the prevention of
infection and has a bactericidal effect by
inhibition of fatty acid synthesis. Escalada 2005 The
suspected SSI observed in this study developed
in a VP cat. This is unexpected because triclosan
should help to prevent a SSI. It might be
possible that the reaction observed in this cat
was not a SSI. It could not be conformed by a
bacterial culture. Nevertheless it was a severe
reaction to the suture material.
For developing an incisional hernia
there are many patient-related risks mentioned
in human literature. No single factor is so
regularly associated that it can be called a
prognosticator Shell, 2008 Coughing or vomiting
can induce changes in fibroblast function and
result in herniation of the incisional wound.
Franz, 2008 More often it is a result of the surgical
technique. Most of the incisional hernias are a
result of surgeon related technical errors. Shell,
2008 Our cat had been vomiting excessively the
first day after surgery and was not confined.
This might contribute to the complication next
to iatrogenic operating failure.
In this study we tried to observe the
tissue reaction in cats to VP in comparison with
V in a clinical setting. This study design had the
benefits that cats can be followed during a
period of time were they are held in their
M. Stapper
normal lifestyle. It is not invasive and there are
no disadvantages for the animals included in
the study. The study was double blinded to
keep the bias as small as possible. The observer
(MS) did not know at the moment of the
controls which cat received which suture
material. After all the controls were performed
the suture material information was provided
by the supervisor (BB). A disadvantage of the
study was that there was no histological
information obtained. The palpation of the
subdermal thickness is subjective even when it
is performed by one person. The animal group
attended for this study was small. This was due
to a low number of ovariectomy operations
performed during the study period. But even
with this small amount of animals and
subjective observations some significant results
are obtained. It might be wisely to prolong the
study to obtain a larger study power and find
more differences between the two materials
used.
Conclusion
Vicryl Plus resulted in less subdermal
thickness than Vicryl. The addition of triclosan
to the coating of Vicryl may be beneficiary for
wound healing process in cats. Further research
is warranted in a larger study group to provide
statistical power for results that are not
significant now.
Acknowledgements
I would like to thank Bouvien Brocks, Jolle
Kirpensteijn and Toon Heijkants for their help
and support during this study. I would also like
to thank the veterinary clinic: Dierenkliniek ‘De
Langstraat’ in Waalwijk for the opportunity to
accomplish the study there and the help from
everyone. I would like to thank the cat owners
and the animal shelter for their trust and time
to cooperate in the study. I would like to thank
Ethicon for their support and providing the
materials.
Tissue Reaction to Vicryl Plus and Vicryl in Cats after Elective Ovariectomy
10
References
1. Fleck T, Moidl R, Blacky A, Fleck M, Wolner E,
2.
3.
4.
5.
6.
7.
8.
9.
Grabenwoger M, Wisser W. Triclosan-Coated
Sutures for the Reduction of Sternal Wound
Infections: Economical Considerations. The
Annals of Thoracic Surgery 2007; 84(1):232-236
Sahlin S, Ahlberg J, Granstörm L, Ljungstörm KG.
Monofilament Versus Multifilament Absorbable
Sutures for Abdominal Closure. British Journal of
Surgery 1993; 80(3):322-324
Storch M, Perry LC, Davidson JM, Ward JJ. A 28Day Study of the Effect of Coated VICRYL Plus
Antibacterial Suture (Coated Polyglactin 910
Suture with Triclosan) on Wound Healing in
Guinea Pig Linear Incisional Skin Wounds.
Surgical Infections 2002; 3(suppl 1):S89-S98
Fick JL, Novo RE, Kirchhof N. Comparison of
Gross and Histologic Tissue Responses of Skin
Incisions Closed by Use of Absorbable
Subcuticular. American Journal of Veterinary
Research 2005; 66(11):1975-1984
Katz S, Izhar M, Mirelman D. Bacterial Adherence
to Surgical Sutures. A Possible Factor in Suture
Induced Infection. Annals of Surgery 1981;
194(1):35-41
Chu CC, Williams DF.
Effects of Physical
Configuration and Chemical Structure of Suture.
American Journal of Surgery 1984; 147(2):197204
Eugster S, Schawalder P, Gaschen F, Boerlin P. A
Prospective Study of Postoperative Surgical Site
Infections in Dogs and Cats. Veterinary Surgery
2004; 33(5):542-550
Gabrielli F, Potenza C, Puddu P, Sera F, Masini C,
Abeni D. Suture Materials and Other Factors
Associated with Tissue Reactivity, Infection, and
Wound Dehiscence among Plastic Surgery
Outpatients. Plastic and Reconstructive Surgery
2001; 107(1):38-45
Edmiston CE, Seabrook GR, Goheen MP, Krepel
CJ, Johnson CP, Lewis BD, Brown KR. Bacterial
Adherence to Surgical Sutures: Can AntibacterialCoated Sutures Reduce the Risk of Microbial
Contamination? Journal of the American College
of Surgeons 2006; 203(4):481-489
10. Johnston DE. Wound Healing in Skin. Veterinary
11.
12.
13.
14.
15.
16.
17.
18.
19.
M. Stapper
Clinics of North America: Small Animal Practice
1990; 20(1):1-25
Niessen FB, Spauwen PH, Kon M. The Role of
Suture Material in Hypertrophic Scar Formation:
Monocryl vs. Vicryl-rapide. Annals of Plastic
Surgery 1997; 39(3):254-260
Austin PE, Dunn KA, Eily-Cofiels K, Brown CK,
Wooden WA, Bradfield JF. Subcuticular Sutures
and
the
Rate
of
Inflammation
in
Noncontaminated Wounds. Annals of Emergency
Medicine 1995; 25(3):328-330
Kirpensteijn J, Maarschalkerweerd RJ, Koeman
JP, Kooistra HS, van Sluijs FJ. Comparison of Two
Suture Materials for Intradermal Skin Closure in
Dogs. Veterinary Quarterly 1997; 19(1):20-22
Yaltrik M, Dedeoglu K, Nilgic B, Koray M, Ersev H,
Issever H, Dulger O, Soley S. Comparison of Four
Different Suture Materials in Soft Tissues of Rats.
Oral Diseases 2003; 9(6):284-286
Storch M, Scalzo H, van Lue S, Jacinto G. Physical
and Functional Comparison of Coated VICRYL
Plus Antibacterial Suture (Coated Polyglactin 910
Suture with Triclosan) with Coated VICRYL Suture
(Coated Polyglactin 910 Suture). Surgical
Infections 2002; 3(suppl 1):S65-S77
Ford HR, Jones P, Gaines B, Reblock M, Simpkins
DL. Intraoperative Handling and Wound Healing:
Controlled Clinical Trial Comparing Coated
VICRYL® Plus Antibacterial Suture (Coated
Polyglactin 910 Suture with Triclosan) with
Coated VICRYL® Suture (Coated Polyglactin 910
Suture). Surgical Infections 2005; 6(3):313-321
Gammelgaard N, Jensen J. Wound Complications
After Closure of Abdominal Incisions with Dexon
or Vicryl. A Randomized Double-Blind Study. Acta
Chirurgica Scandinavica 1983; 149(5):505-508
Freeman LJ, Pettit GD, Robinette JD, Lincoln JD,
Person MW. Tissue Reaction to Suture Material
in the Feline Linea Alba. A Retrospective,
Prospective, and Histologic Study. Veterinary
Surgery 1987; 16(6):440-445
Hohenleutner U, Egner N, Hohenleutner S,
Landthaler M. Intradermal Buried Vertical
Mattress Suture as Sole Skin Closure: Evaluation
of 149 Cases. Acta Dermato Venereologica 2000;
80(5):344-347
Tissue Reaction to Vicryl Plus and Vicryl in Cats after Elective Ovariectomy
11
20. Jones RD, Jampani HB, Newman JL, Lee AS.
21.
22.
23.
24.
25.
26.
27.
28.
29.
Triclosan: A Review of Effectiveness and Safety in
Health Care Settings. American Journal of
Infection Control 2000; 28(2):184-196
Gilbert P, McBain AJ. Literature-Based Evaluation
of the Potential Risks Associated with
Impregnation of Medical Devices and Implants
with Triclosan. Surgical Infections 2002; 3(suppl
1):S55-S63
Barbolt TA. Chemistry and Safety of Triclosan,
and Its Use as an Antimicrobial Coating. Surgical
Infections 2002; 3(suppl 1):S45-S53
Gómez-Alonso A, García-Criado FJ, ParreñoManchado FC, García-Sánchez JE, García-Sánchez
E, Parreño-Manchado A, Zambrano-Cuadrado Y.
Study of the Efficacy of Coated VICRYL Plus®
Antibacterial Suture (Coated Polyglactin 910
Suture with Triclosan). Journal of Infection 2007;
54(1):82-88
Rothenburger S, Spangler D, Bhende S, Burkley
D. In Vitro Antibacterial Evaluation of Coated
VICRYL Plus Antibacterial Suture (Coated
Polyglactin 910 with Triclosan) using Zone of
Inhibition Assays. Surgical Infections 2002;
3(suppl 1):S79-S87
Storch ML, Rothenburger SJ, Jacinto G.
Experimental Efficacy Study of Coated VICRYL
plus Antibacterial Suture in Guinea Pigs
Challenged with Staphylococcus Aureus. Surgical
Infections 2004; 5(3):281-288
Marco F, Vallez R, Gonzalez P, Ortega L, de la
Lama J, Lopez-Duran L. Study of the Efficacy of
Coated Vicryl Plus Antibacterial Suture in an
Animal Model of Orthopedic Surgery. Surgical
Infections 2007; 8(3):359-365
Rijnberk A, van Sluijs FJ. Anamnese en
Lichamelijk Onderzoek bij Gezelschapsdieren,
Bohn Stafleu van Loghum 2005; 2nd print:55-77
Slingsby L, Jones A, Waterman-Pearson AE. Use
of a New Finger-Mounted Device to Compare
Mechanical Nociceptive Thresholds in Cats Given
Pethidine or no Medication after Castration.
Research in Veterinary Science 2001; 70(3):243246
Väisänen MAM, Tuomikoski SK, Vainio OM.
Behavioral Alterations and Severity of Pain in
Cats Recovering at Home Following Elective
30.
31.
32.
33.
34.
35.
36.
M. Stapper
Ovariohysterectomy or Castration. Journal of
American Veterinary Medicine Association 2007;
231(2):236–242
Purina, Proplan; Zwijndrecht
Hardie EM. Recognition of Pain Behavior in
Animals. In: Hellebrekers, LJ, Animal pain.
Utrecht, Netherlands: van der Wees 2000; 51-69
Robertson SA. Managing Pain in Feline Patients.
Veterinary Clinics of North America: Small
Animal Science 2005; 35(1):129-146
Vasseur PB, Levy J, Down E, Eliot J. Surgical
Wound Infection Rates in Dogs and Cats. Data
From a Teaching Hospital. Veterinary Surgery
1988; 17(2):60-64
Escalada MG, Harwood JL, Maillard JY, Ochs D.
Triclosan Inhibition of Fatty Acid Synthesis and
its Effect on Growth of Escherichia coli and
Pseudomonas.
Journal
of
Antimicrobial
Chemotherapy 2005; 55(6):879-882
Shell DH, de la Torre J, Andrades P, Vasconez LO.
Open Repair of Ventral Incisional Hernias.
Surgical Clinics of North America 2008; 88(1):6183
Franz, MG. The Biology of Hernia Formation.
Surgical Clinics of North America 2008; 88(1):115
Tissue Reaction to Vicryl Plus and Vicryl in Cats after Elective Ovariectomy
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Attachments
Total: mean (+/- SD)
V: mean (+/- SD)
VP: mean (+/- SD)
Age (months)
13.53 (+/- 8.36)
12.88 (+/- 6.20)
14.00 (+/- 9.91)
Weight (kg)
2.63 (+/- 0.46)
2.82 (+/- 0.46)
2.49 (+/- 0.43)
Body condition score (0-9)
4.95 (+/- 0.85)
5.00 (+/- 0.76)
4.91 (+/- 0.94)
Preparation time (min)*
35.16 (+/- 19.05)
26.13 (+/- 11.78)
41.73 (+/ -21.06)
Operation time (min)
14.42 (+/- 3.44)
15.00 (+/- 3.59)
14.00 (+/- 3.44)
Stitching time (min)
6.05 (+/- 0.97)
5.88 (+/- 1.13)
6.18 (+/- 0.87)
Recovery time (min)
16.47 (+/- 5.85)
16.63 (+/- 6.93)
16.36 (+/- 5.30)
Anesthetic time (min)
66.05 (+/- 17.71)
57.75 (+/- 9.79)
72.09 (+/- 20.05)
Suture used (cm)
28.99 (+/- 2.45)
29.71 (+/- 3.13)
28.53 (+/- 1.93)
Recovery pain
33.95 (+/- 11.85)
30.00 (+/- 12.54)
36.82 (+/- 11.02
Recovery swelling knot (mm)
3.68 (+/- 0.89)
3.88 (+/- 0.99)
3.55 (+/- 0.82)
Recovery swelling midline incision (mm)
2.23 (+/- 0.83)
2.00 (+/- 1.10)
2.43 (+/-0.53)
Recovery swelling exterior (mm)
3.16 (+/- 1.07)
3.25 (+/- 1.04)
3.09 (+/- 1.14)
Table 1: distribution of patients. There was a longer preparation time in the VP group (p<0.05)
Figure 1 Subdermal thickness. There is a difference in subdermal thickness in C2 and C3 resulting in a more
severe thickness subdermal in V cats. (p<0.05)
M. Stapper
Tissue Reaction to Vicryl Plus and Vicryl in Cats after Elective Ovariectomy
13
Figure 2: Crusting of the wounds. There is no significant difference between the materials used.
Figure 3: Pain scores. There was no significant difference between the two materials used in their pain scores.
M. Stapper
Tissue Reaction to Vicryl Plus and Vicryl in Cats after Elective Ovariectomy
14
Figure 4: Swelling of the wound edges. The data recorded for the recovery are the actual width of the wound
edges measured. The other data are expansions of the recovery data. (Data shown in mm.) There is no significant
difference in swelling of the wound edges between the two materials used.
M. Stapper
Tissue Reaction to Vicryl Plus and Vicryl in Cats after Elective Ovariectomy
15
Figure 5: V wound on C2. The subdermal thickness is severe under the whole incision line.
Figure 6: V wound on C4. The subdermal thickness has dissolved.
M. Stapper
Tissue Reaction to Vicryl Plus and Vicryl in Cats after Elective Ovariectomy
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Figure 7: VP wound on C2. The subdermal thickness is located at the suture knots.
Figure 8: VP wound on C4. The subdermal thickness has dissolved.
M. Stapper