Biologic grafts for ventral hernia repair: a systematic
Nicholas J. Slater, B.Sc.*, Marion van der Kolk, M.D., Thijs Hendriks, Ph.D.,
Harry van Goor, M.D., Ph.D., Robert P. Bleichrodt, M.D., Ph.D.
Department of Surgery, Radboud University Nijmegen Medical Centre, PO Box 9101, 6500 HB, Nijmegen,
Ventral hernia repair;
BACKGROUND: Biologic grafts hold promise of a durable repair for ventral hernias with the poten-
tial for fewer complications than synthetic mesh. This systematic review was performed to evaluate the
effectiveness and safety of biologic grafts for ventral hernia repair.
METHODS: MEDLINE, Embase, and Cochrane Central Register of Controlled Trials were searched
for studies on biologic grafts for the repair of ventral hernias. Outcomes are presented as weighted
RESULTS: Twenty-five retrospective studies were included. Recurrence depended on wound class,
with an overall rate of 13.8% (95% confidence interval [CI], 7.6–21.3). The recurrence rate in contam-
inated/dirty repairs was 23.1% (95% CI, 11.3–37.6). Abdominal wall laxity occurred in 10.5% (95%
CI, 3.7–20.3) of patients. The surgical morbidity rate was 46.3% (95% CI, 33.3–59.6). Infection
occurred in 15.9% (95% CI, 9.8–23.2) of patients but only led to graft removal in 4.9% of cases.
CONCLUSIONS: No randomized trials are available to properly evaluate biologic grafts for ventral
hernia repair. The current evidence suggests that biologic grafts perform similarly to other surgical op-
tions. Biologic grafts are associated with a high salvage rate when faced with infection.
? 2013 Elsevier Inc. All rights reserved.
Incisional hernia is a common complication after lapa-
rotomy, occurring in 10% to 20% of cases.1,2Since the in-
troduction of synthetic prostheses, repair of the defect with
polypropylene mesh or expanded polytetrafluorethylene has
become the mainstay of treatment showing good short- and
long-term results.3,4The drawback of prosthetics is adhe-
sion formation to the viscera, which may cause bowel ob-
struction or erosion into the viscera.5Surgeons are also
reluctant to implant synthetic prostheses in complex hernias
because of an increased risk of infection and mesh extru-
sion. Complicated hernias have not been properly defined
but usually include repairs combined with bowel surgery
or in the presence of enterocutaneous fistulas, multiple re-
current hernias, previous or current (mesh) infection, and
hernias after trauma or tumor resection.
Biologic grafts have been introduced as an alternative to
synthetic mesh. They consist of an extracellular collagen
matrix. The graft is incorporated into the surrounding tissue
by ingrowth of fibrocollagenous tissue and blood vessels.
During incorporation, the graft is gradually degraded and
theoretically remodeled into a neofascia to withstand the
mechanical forces of the abdominal wall.6Commercially
available biologic grafts used for ventral hernia repair are
The authors declare no conflicts of interest.
* Corresponding author. Tel.: 131-24-361-6421; fax: 131-24-354-
E-mail address: firstname.lastname@example.org
Manuscript received October 24, 2011; revised manuscript March 12,
0002-9610/$ - see front matter ? 2013 Elsevier Inc. All rights reserved.
The American Journal of Surgery (2013) 205, 220-230
derived from human and porcine dermis, porcine small in-
testinal submucosa, and bovine pericardium. After harvest-
ing, all tissues undergo decellularization aimed at the
prevention of a foreign-body response. Some biologic
grafts are dehydrated during processing to extend shelf-
life, reduce extensibility, make them easier to handle, and
limit the loss of growth factors during storage. A minority
of biologic grafts undergo additional cross-linking. During
this process, extra bonds are added between the polymers of
the collagen matrix aimed at controlling the enzymatic deg-
radation of the graft, which is claimed to be beneficial in a
Because of their biocompatible nature, biologic grafts
hold promise of a durable repair and lower infection
propensity compared with synthetic mesh. The aim of this
systematic review was to summarize and evaluate the use of
biologic prostheses for ventral hernia repair under clean and
contaminated conditions with a focus on recurrence and
Search methods for the identification of studies
Electronic databases were searched to identify relevant
studies. No restrictions were set on language or publication
status. By using PubMed and Ovid, the search covered
databases MEDLINE (including In-Process & Other Non-
present), and the Cochrane Central Register of Controlled
Trials. Current registered trials were also identified in the
metaRegister of Controlled Trials. Considering the scarcity
of studies on the biological materials, a high sensitivity
with a consequently low precision was chosen for the search
strategy. The following search terms were used: hernia,
abdominal-wall defect, reconstruction, and repair. These
[LifeCell Corp, Branchburg, NJ], Collamend [Davol Inc.,
[Synovis, St. Paul, MN], Permacol [Covidien, Mansfield,
MA], Pelvicol [Bard, Olen, Belgium], Strattice [LifeCell
Corp, Branchburg, NJ], Surgisis [Cook Surgical, Blooming-
ton, IN], Tutomesh [Taureon GmbH, Lienen, Germany],
Veritas [Synovis, St. Paul, MN] and Xenmatrix [Davol
Inc., Warwick, RI]) and the generic names (ie, human acel-
lular dermal matrix/allograft, acellular dermis, small intesti-
nal submucosa, porcine dermal matrix/graft, porcine dermis,
and bovine pericardium) of the various collagen-based pros-
theses. All terms were searched for as free text and, where
possible, mapped to Medline subject headings. Preliminary
screening of titles and abstracts was undertaken. Then,
full-text articles of eligible studies were retrieved for evalu-
were manually scanned for additional studies missed in the
electronic search. To preventdouble counts of data, different
studies by the same authors were scanned for uniqueness
with regard to the included patients. The most recent study
with the longestfollow-up was chosen inthe case ofoverlap.
The last search was performed on November 16, 2010. The
characteristics andcostsofthe biologicgrafts usedinventral
hernia repair were sought in the literature, on the manufac-
turers’ web sites, and via telephone contact with the manu-
facturer and/or distributor. Costs presented are based on
standard sheet sizes and exclude any form of discount.
Inclusion and exclusion criteria
Studies including men and women over the age of 18
who underwent definitive repair of all types (ie, incisional,
epigastric, Spiegel [lateral ventral], and [para-]umbilical) of
ventral hernias were selected. In addition, the reconstruc-
tion of large defects created during surgery (eg, transverse
rectus abdominus myocutaneous (TRAM) flap reconstruc-
tion and tumor resection) or trauma were included. The
biological prosthesis had to be the sole graft material used
to repair the defect. Studies on biologic grafts placed as
reinforcement or as a bridging material were included.
Studies with less than 7 patients were excluded.
The methodological quality and the risk of bias of each
individual remaining study were assessed by subjecting it to
a modified version of the methodological index for non-
randomized studies tool 7 (Table 1). This instrument was
item results in a maximum score of 14. Studies that scored a
0 on items 2, 5, or 7 or had a total score of less than 8 were
excluded from analysis of the primary outcome. All articles
selected for inclusion during the search process were scored
independently by 2 authors (NJS and RPB). Disagreement
was resolved by discussion and consensus.
Primary and secondary outcomes
The primary outcome of this systematic review was
recurrence as defined by the authors in the individual reports
follow-up duration and included mortality, laxity of the
repair, surgical site infection, deep (fascial) wound dehis-
cence, seroma and haematoma formation, enterocutaneous
fistula, and the total number of surgical complications.
Data extraction and subgroup formation
All data were extracted using a predesigned data form.
The demographic variables age, body mass index (BMI),
size of defect, comorbidities, American Society of Anes-
thesiologists (ASA) score, the indication for surgery and
wound class, and the surgical technique (ie, open or
laparoscopic, reinforcement or bridging, and anatomic
position) were noted. Reinforcement repair is defined as
the placement of a graft to augment approximated native
N.J. Slater et al. Biologic grafts for ventral hernia repair221
fascia, whereas in bridging there is no (complete) approx-
imation of native fascia. The anatomic position of the
prosthesis was defined as subcutaneous on top of the
anterior rectus fascia (‘‘onlay’’), between the rectus muscle
and the posterior rectus fascia (‘‘preperitoneal underlay’’ or
the Rives-Stoppa technique), behind the posterior rectus
sheath (‘‘intraperitoneal underlay’’ or modified Rives-
Stoppa technique), or within the defect and sutured directly
to the fascial edges (‘‘interpositional’’ or ‘‘inlay’’).
Certain assumptions were made while extracting infor-
mation because of the lack of consistency of reporting and
terminology in the reports. Only complications explicitly
noted in the methods or results section were counted.
Laxity, diastasis, and ‘‘bulging’’ were all grouped as laxity
of the repair. Superficial wound dehiscence was counted as
a wound infection. The total number of surgical complica-
tions per study was calculated by adding up all reported
surgical complications. In case additional data were
needed, authors were contacted.
Subgroups were formed for wound class (ie, clean/clean-
contaminated, contaminated/dirty, or complicated), biologic
graft (ie, Alloderm, Permacol, or Surgisis), and surgical
technique (ie, reinforcement or bridging). Where necessary,
patients from a single study were divided between different
subgroups. Wound classification was performed according
to the US National Research Council group.8Patients classi-
fied by the authors were grouped accordingly. If this was not
done by the authors, the indications for surgery were re-
viewed to determine the wound classes. The classes clean
andclean-contaminated weregroupedtogether, andcontam-
inated and dirty were grouped together. The third group
(complicated) consisted of patients who could not be strati-
fied into the first 2 groups (ie, clean/clean-contaminated and
contaminated/dirty) and/or had complex, complicated, or
potentially contaminated hernias as noted by the authors.
In the wound class subgroups, data allowed for the
extraction of the outcomes recurrence, infection, and total
surgical morbidity. Biologic grafts subgroups were ana-
lyzed with regard to the following outcomes: recurrence,
laxity, seroma, and total surgical morbidity. Surgical tech-
niques were analyzed with regard to recurrence and laxity.
Weighted pooled proportions with 95% confidence
intervals (CIs) using the random-effects (DerSimonian-
Laird) model were calculated for all primary and secondary
outcomes and are presented for subgroups and the whole
group. Differences in weighted pooled proportions were
analyzed using the chi-square test and only performed
on outcomes that could be stratified by wound class.
A P value , .05 was considered statistically significant.
neity of the wound class subgroups was quantified using I2.
Analysis of outcome differences between grafts was not un-
dertaken because insufficient data left subgroups that were
too small or empty after stratification by both wound class
to explore the relationship between recurrence and the out-
comes infection and overall surgical complications. Median
scores were calculated for the modified Methodological In-
dex of Non-Randomised Studies (MINORS) indices and
for the reported means of months follow-up, age, BMI, and
the size of the hernia defect. Univariate analyses were
1 A clearly stated aimNot reported
Partially reported, no clear aim
Patients in a certain time period
Consecutive patients 1 characteristics
Not reported/unclear/telephone used
Clinical examination 1 CT/Ultrasound
Reported clearly, appropriate to aim
Stated but inadequate
Recurrences and postoperative complications
2 Minimum of 5 patients included
3 Inclusion of consecutive patients
4 Diagnostic modality of follow-up
5 Surgical methods (ie, anatomic placement of prosthesis,
surgical technique, bridge/reinforcement used)
6Endpoints clearly stated in methods section
7 Endpoints appropriate to aim
222 The American Journal of Surgery, Vol 205, No 2, February 2013
analyses were performed using StatsDirect statistical soft-
ware (StatsDirect Ltd., Cheshire, England).10
The search strategy yielded a total of 1,152 titles and
abstracts (Fig. 1). A total of 27 studies11–37were included
in the systematic review. Seventeen studies provided suffi-
cient follow-up and were included for primary outcome
analysis, and 25 studies were included for secondary out-
come analysis. Although various studies reported on using
prospectively collected data, none of them elaborated on
how data were collected according to a protocol rendering
them qualitatively indistinguishable from the retrospective
studies. The median modified MINORS score of the in-
cluded studies was 11 (range 8–14) (Table 2).
Most studies reported age (82%) and BMI (52%),
whereas less than half reported the ASA score (44%) and
the size of the defect (40%). The median of reported means
were 54.5 years, 32.0 kg/m2, and 150.0 cm2for age, BMI,
and the size of the defect, respectively. All reported median
ASA scores were 3. No differences between subgroups
were found for age (P 5 .108) or BMI (P 5 .123).
Alloderm, Permacol, and Surgisis
Three biologic grafts were found almost exclusively in
the ventral hernia literature and were included for primary
outcome analysis: Alloderm, Permacol, and Surgisis.
Alloderm is an allograft derived from human cadaveric
dermis and is available in sizes up to 16 ! 20 cm and costs
$35.31 per cm2. Varying thicknesses are available includ-
ing .79 to 2.03 mm (‘‘Thick’’) and 2.06 to 3.30 mm
(‘‘X-Thick’’). To prevent physical and chemical alterations
because of sterilization, after decellularization Alloderm is
not sterilized but instead treated with antibiotic agents and
packaged aseptically. Alloderm needs to be stored refriger-
ated, undergo a 2-step rehydration (10-40 minutes depend-
ing on the thickness), and be prestretched for hernia repair
to prevent otherwise expected laxity.
Permacol is derived from porcine dermis and has the
largest grafts available with sizes up to 28 ! 40 cm costing
$18.97 per cm2. Grafts are available with thickness varying
from .5 mm to 1.5 mm. After decellularization, Permacol is
sterilized by gamma radiation and is packaged in a hy-
drated state that makes it usable straight away without
any preparation. Permacol undergoes additional cross-
linking during processing by hexamethylene diisocyanate
aimed at decreasing its biodegradability, which might be
accelerated in contaminated wounds.
Surgisis is made from porcine small intestinal submu-
cosa and is available in sizes up to 20 ! 30 cm. The cost
per cm2graft is $20.00. Material harvested from small in-
testinal submucosa is thin, but Surgisis undergoes lamina-
tion to make it thick enough (up to 2.0 mm) for hernia
repair. This graft undergoes ethylene oxide sterilization
and is packed dehydrated, making rehydration necessary
before implantation. Surgisis has been found to retain cer-
tain proteoglycans, glycosaminoglycans, and angiogenic
growth factors that potentially stimulate cell attachment
Mortality was reported in 19 series11,12,14–16,18–20,22,23,27,
28,30,31,33–37including 879 patients. Thirty-six (4.1%) pa-
tients died; 20 (2.3%) died within 30 days of surgery.
One study described 2 deaths after multiple attempts to re-
pair enterocutaneous fistulas.16All other deaths were noted
as unrelated to the ventral hernia repair (eg, multiple organ
failure, congestive heart failure, and disseminated intravas-
ing Items for Systematic Reviews and Meta-Analyses. Search per-
formed in databases Cochrane Central Register of Controlled
Trials, Embase, MEDLINE, and MEDLINE In-Process & Other
box includes information from references.38–54
Search flow chart in accordance with Preferred Report-
N.J. Slater et al. Biologic grafts for ventral hernia repair223
Table 3 presents the surgical morbidity divided by wound
class. Overall, surgical morbidity could be extracted for
1,152 patients out of 25 studies11–18,20–26,28–37in which
584 surgical complications (46.3%; 95% CI, 33.3–59.6)
were documented. Infectious complications were reported
most often. Wound infections were reported in 246 of
1,109 (15.9%; 95% CI, 9.8–23.2) patients.12,14–18,20,22–
30,32,34–37In 12 patients (4.9%), the prostheses had to be re-
moved.26,29,34,36Other infectious complications were intra-
abdominal abscesses in 2.4% and miscellaneous in 2.7%.
Seromaformationwasreported in115of827(14.2%, 95%
CI, 9.5–19.5) patients (Table 4).14–18,21,23,24,26,28,32,35,37Five
cases of explantation after significant seroma formation
were documented in 1 report of repair with Surgisis.17All
other seromas resolved either spontaneously or after percu-
taneous aspirations. Hematomas were reported 9 times in
354 patients (3.0%, 95% CI 1.4–5.3).12,14,15,17,20,22,24,33,35
Deep wound dehiscence necessitating operative inter-
vention was documented in 16 of 191 patients (8.6%; 95%
CI, 6.2–11.2).12,22,24,36The postoperative course was com-
plicated by an enterocutaneous fistula in 59 of 756 patients
(6.5%; 95% CI, 3.5–10.3).13–16,21–23,25,27,30,32,34Fifty-six
percent was related to fistula takedown performed concom-
itantly with the hernia repair, 10.4% after bowel surgery,
and 12.6% in patients with open wounds or after simple
ventral hernia repair. Other postoperative wound-related
complications were skin necrosis/breakdown (14/83 pa-
tients, 16.9%) and graft rejection/degradation (4/157, 2.5%).
Medical complications were inconsistently reported.
The data allowed for the comparison of morbidity be-
tween wound classes regarding infection and total surgical
total surgical morbidity (P ,.0001) were both dependent on
wound class. Infection was significantly higher in the con-
taminated/dirty group than in the clean/clean-contaminated
group (P 5.0016; OR 5 1.9; 95% CI, 1.24–2.91). Infection
Study characteristics and recurrence rates for ventral hernia repair with biologic grafts
of defect, cm2
No. of C/D
Buinewicz et al14
Glasberg et al17
Gupta et al18
Boehmler et al13
Helton et al36
Gupta et al18
Overall C/CC (95% CI)*
Buinewicz et al14
Alaedeen et al11
Taner et al28
Ueno et al37
Helton et al36
Gupta et al18
Connolly et al31
Overall C/D (95% CI)*
Kolker et al21
Jin et al19
Candage et al15
Lee et al22
Parker et al34
Shaikh et al35
Hsu et al32
Loganathan et al33
Overall combined (95% CI)*
84 23.1% (11.3–37.6)
C/CC 5 clean/clean-contaminated; C/D 5 contaminated/dirty; NA 5 not available; NS 5 not specified.
*This subgroup contains groups of patients for which the outcomes could not be stratified per wound class and/or that contained cases with unclear
surgical indications that were classified by the corresponding authors as either ‘‘complex,’’ ‘‘complicated,’’ ‘‘potentially contaminated,’’ or ‘‘high risk.’’
†Weighted pooled proportion using the random-effects (DerSimonian-Laird) model.
224The American Journal of Surgery, Vol 205, No 2, February 2013
was also significantly higher in the complicated group
than in the clean/clean-contaminated group (P 5 .004;
OR 5 1.7; 95% CI, 1.16–2.39).
The contaminated/dirty subgroup showed a significantly
higher total surgical morbidity rate compared with the
clean/clean-contaminated subgroup (P 5.0064; OR 5 1.8;
95% CI, 1.15–2.75). The complicated subgroup also had
significantly higher overall surgical morbidity compared
with the clean/clean-contaminated subgroup (P , .0001;
OR 5 3.3; 95% CI, 2.39–4.58).
Seventeen studies11,13–15,17–19,21,22,28,31–37with a total
enrollment of 531 patients met the inclusion criteria for
the primary outcome. Overall, there were 86 recurrences
(13.8%; 95% CI, 7.6–21.3; Table 3). Weighted pooled re-
currence rates for each wound class are presented in
Table 3 and Fig. 2. There were significantly less recurrences
in the clean/clean-contaminated group compared with the
contaminated/dirty group (P , .0001; OR 5 55.9; 95%
CI, 8.5–2,321.3) and the complicated group (P , .0001;
OR 5 39.0; 95% CI, 6.5–1,581.0; Table 3). No significant
difference was found between the contaminated/dirty and
the complicated subgroup (P 5 .2233).
To identify factors associated with recurrent hernia,
univariate regression was performed. Postoperative infec-
tion (r25 .325, P 5.011, Fig. 3) and total surgical morbid-
ity (r25 .189, P 5.038, Fig. 4) were revealed as significant
explanatory variables for recurrent hernia.
Laxity of the repair was documented in 8 studies12–14,17,
18,21–23including 451 patients and occurred in 51 patients
(10.5%; 95% CI, 3.7–20.3). All cases of laxity were re-
ported with the use of Alloderm.
Recurrence and/or laxity by type of closure were
adequately documented in 14 studies including 380 pa-
tients.11–15,17,19,27,28,30–32,35,37In patients who underwent
reinforcement, recurrence occurred in 14 of 161 (8.1%;
Pooled proportions of recurrence, infection, and total surgical morbidity divided by wound class
ComplicationWound classNo. of studies No. of patientsIncidence % (95% CI)* Significance
9 2.9 (.2–8.3)
P , .0001x
P 5 .0077x
Total surgical morbidity
P , .0001x
C/CC 5 clean/clean-contaminated; C/D 5 contaminated/dirty; Comp 5 complicated.
*Weighted pooled proportion using the random-effects (DerSimonian-Laird) model.
†This subgroup contains groups of patients for which the outcomes could not be stratified per wound class and/or that contained cases with unclear
surgical indications that were classified by the corresponding authors as either ‘‘complex,’’ ‘‘complicated,’’ ‘‘potentially contaminated,’’ or ‘‘high risk’’.
‡Does not add up because 1 or more studies were split into multiple groups.
xStatistically significant difference using the chi-square test.
Pooled proportions of infection, seroma, and total surgical morbidity divided by biologic graft
Complication MaterialNo. of studies No. of patientsIncidence% (95% CI)*
Total surgical morbidity 16 502
*Weighted pooled proportion using the random-effects (DerSimonian-Laird) model.
N.J. Slater et al.Biologic grafts for ventral hernia repair225
95% CI, 2.2–17.2). Laxity was observed in 9 of 72 patients
(9.7%; 95% CI, .1–32.1). Only 3 studies (75 patients) pro-
vided the mean size of defect specifically for reinforced re-
pairs; it ranged from 86 to 180 cm2.14,19,35
In patients in whom the defect was bridged, recurrence
occurred in 39 of 219 (21.8%; 95% CI, 7.5–40.9). La-
xity was reported in 28 of 138 patients (21.0%; 95% CI,
14.8–28.0). The mean size of defect could be extracted for
bridging repairs in 7 studies (168 patients), with a median
of 158.0 cm2(range 147–210 cm2).12,14,17,19,27,30,32
Of all repairs, underlay placement of the graft was the
most used technique (57.3%) followed by inlay (25.9%),
onlay (14.7%), and ‘‘sandwich’’ placement including both
onlay and underlay placement of prostheses (2.1%). About
inated/dirty (I25 52.9%), and (C) complicated (I25 64.2%) ventral hernia repair with biologic grafts. The square size represents the
weight of the study, and the horizontal line through the square represents the CI of the effect estimate.
Meta-analysis (random-effects model) of proportions of recurrences of (A) clean/clean-contaminated (I25 68.4%), (B) contam-
226 The American Journal of Surgery, Vol 205, No 2, February 2013
a third of the authors (31.0%) reported the additional use of
the component separation technique in some or all of their
patients to achieve primary fascial closure. Inadequate
reporting made it impossible to relate component separa-
tion technique or the type of anatomic graft position to any
The current systematic review evaluated postoperative
morbidity and the recurrence rate after ventral hernia repair
with biologic grafts. Half of the patients suffered wound-
related morbidity. Infectious complications developed in a
fifth of the patients but only rarely necessitated graft
removal. The overall recurrence rate was 13.8% after a
mean follow-up of 18 months. The recurrence rate was low
(2.9%) in clean and clean-contaminated cases and in-
creased with the extent of contamination. Nearly a quarter
of the patients undergoing contaminated, dirty, or otherwise
complicated repair experienced a recurrence. Overall, lax-
ity of the repair occurred in 1 out of 10 patients.
Quality of studies
The quality of evidence rates a 4 (recommendation
grade C) according to the Oxford Centre for Evidence-
based Medicine levels of evidence.55The current findings
are troubled by the heterogeneity of patients and hernia
characteristics within and between studies. The interpreta-
tion of data was difficult because of the lack of uniformity
in definitions, terminology, and reporting. Classification of
hernias following the European Hernia Society guidelines
was not possible.56
A limited follow-up is a well-recognized flaw in many
studies. In this review, a study follow-up of at least
12 months was considered sufficient to provide a reliable
outcome, realizing that recurrence rates are underestimated
and increase up to and beyond 13 years after repair.4,57
Despite these limitations, results of the current study are
meaningful because a large number of patients who under-
went ventral hernia repair using biologic grafts were
included, encompassing 531 patients to determine recur-
rence rate and 1,152 patients for secondary outcome param-
eters. Also, outcome stratification by wound class made
more homogenous groups.
Postoperative morbidity increased with wound class,
overall occurring in nearly half of the patients. Because of
the inability to stratify surgical complications by both
wound class and biologic graft, safety comparisons be-
tween different grafts are hard to undertake. Still, certain
outcomes were surprising and deserve further attention.
Seroma formation was the second most common post-
operative complication, occurring in 14.2% of patients.
Noteworthy is the high rate of seroma formation found with
the use of Surgisis, which is also observed after laparo-
scopic hernia repair.44,47This may be because of delamina-
tion of the graft or an enhanced inflammatory response.
Gupta et al18performed histologic analysis on grafts ex-
planted after significant seroma formation and found that
they were only partially incorporated and remodeled into fi-
brocollagenous tissue, allowing seroma formation between
the different (unincorporated) layers of the graft. An exag-
gerated inflammatory response to small intestinal submu-
cosa grafts was reported in 3 publications. Helton et al36
observed a pronounced inflammatory response in 6 of 53
outcome and the infection rate as the predictor (r25 .325,
P 5 .011). Circles represent observed rates in the studies, and
the line represents the linear regression.
Univariate regression with the recurrence rate as the
outcome and the overall surgical morbidity rate as the predictor
(r25 .189, P 5.038). Circles represent observed rates in the stud-
ies, and the line represents the linear regression.
Univariate regression with the recurrence rate as the
N.J. Slater et al.Biologic grafts for ventral hernia repair227
patients (11%) in whom a Surgisis graft was implanted.
Fluid aspiration around the graft presented a negative cul-
ture, and the inflammatory response rapidly decreased in
all patients with anti-inflammatory medication. Zheng
et al (unpublished data, February 2005) observed transient
noninfectious edema and pain in patients treated for rotator
cuff injury with Surgisis grafts. Similar inflammatory re-
sponses were observed after implantation of small intestinal
submucosa–derived products in pubourethral sling proce-
dures.58Cell remnants and other immunogenic material,
noncollagenous proteins, growth factors, and glycosamino-
glycans found in porcine small intestinal submucosa may
Infection was the most common postoperative compli-
cation and increased with the extent of wound contamina-
tion, with an overall rate of 15.9% (Table 3). The high
infection rates seem to refute the claims that biologic grafts
are infection resistant because of their biocompatibility and
direct access of immune cells. However, the majority of in-
fections were superficial, and the biologic graft could
nearly always be salvaged. Grafts were removed in only
4.9% of infected cases.
In a recent meta-analysis of incisional hernia repair with
synthetic mesh, open repairs resulted in seroma formation
in 15.5% and hemorrhagic complications in 5.9%. Infection
not requiring mesh removal occurred in 10.1%, and infec-
tions requiring removal occurred in 3.5%, meaning a
quarter of all infections required mesh removal.62A
meta-analysis of the component separation technique for
ventral hernia repair revealed an 18.9% infection rate, con-
tributing to an overall complication rate of 23.8%.63Given
the current evidence, biologic grafts do not seem to result in
fewer surgical complications than other techniques. How-
ever, biologic grafts are associated with a high salvage
rate in cases of infection. After synthetic mesh repair,
mesh removal is often mandatory when infection develops.
Recurrence and laxity
Recurrence rates were also related to the extent of
wound contamination. Reconstruction in a contaminated
field is a major indication for the use of biologic grafts.
Surprisingly, about a quarter of repairs in the included
studies were performed under clean or clean-contaminated
conditions. In this group, the recurrence rate was low (2.9%)
and similar to recurrence rates after synthetic mesh repair
found in a meta-analysis.62
The recurrence rates for the contaminated/dirty and
complicated subgroups were 23.1% and 19.4%, respec-
tively. Despite the reluctance to use synthetic mesh in a
contaminated environment, similar results were reported
after synthetic mesh repair in selected contaminated and
complex ventral hernia repairs including concomitant en-
terostomy closure, necrotic bowel resection, enterocuta-
neous fistula takedown,and
procedures.64–70Recurrence rates varied between 0% and
21% and morbidity between 15.8% and 26%. Given these
results, there are still possible indications for synthetic
mesh use in the certain compromised wound environments.
However, the option of a 1-stage repair in grossly infected
wounds still makes biologic grafts a potential attractive al-
ternative to 2-stage repair with synthetic mesh. Techniques
of autologous repair have been summarized and also yield
similar results.63Of these, the component separation tech-
nique met with wide acceptance, yielding an 18.2% rate
of recurrence found in a meta-analysis63and more recent
studies showing even lower rates.53,71In view of the current
evidence, biologic grafts have similar results to synthetic
mesh or autologous repair in either clean, contaminated,
or complicated ventral hernia repair.
Laxity is a common complication with the use of
biologic grafts, showing an overall rate of 10.5%. Unlike
hernias, which can be debilitating and coincide with a risk
of strangulation, laxity does not necessarily affect a
patient’s functionality and it is unclear what effect it has
on quality of life. However, its occurrence is considered a
All reported cases of laxity in this review were related to
repairs with Alloderm. The high elastin/collagen ratio,
insufficient prestretching, no additional cross-linking, and
thin and vulnerable border regions because of the derma-
tome harvest from human cadavers may all be responsible
for bulging. Laxity is rarely investigated with the use of
synthetic mesh, and the prominent focus it receives in
studies on biologic grafts may be an attention bias. How-
ever, in their study comparing human acellular dermal
allograft (Alloderm) with polypropylene mesh repair of
abdominal wall defects after TRAM flap harvesting,
Boehmler et al13reported rates of bulging and other com-
plications of 29% and 39% in the Alloderm group and 7%
and 17% in the polypropylene mesh group, respectively.
When taking laxity into account alongside reherniation, a
quarter of all patients experienced full or partial failure of
the integrity of their abdominal wall reconstruction.
A relevant aspect of hernia repair, whether bridging the
defect or reinforcing the closure, is the anatomic position of
the prosthesis. Unfortunately, the data did not allow for
pooled analysis. In individual reports, it was found that
interpositional (inlay) placement of the prostheses while
bridging the defect resulted in higher recurrence rates
compared with methods in which an adequate overlap
between the prosthesis and the adjacent fascia was
A major issue surrounding biologic grafts is their high
price. Depending on the choice of product, a 150 cm2pros-
thesis costs between $2,845 and $5,311. In the clinic, proper
228 The American Journal of Surgery, Vol 205, No 2, February 2013
evidence and clear indication for their use is thus paramount
for the provision of not only effective but also efficient
health care. Claims are made by the industry that long-
term financially beneficial outcomes are to be expected
with biologic grafts when taking into account less short-
and long-term complications compared with other tech-
niques.72These analyses are based on scant literature and
should be strengthened by more evidence from properly de-
signed trials comparing the various techniques available.
The current review did not compare biologic with
synthetic prostheses. No randomized controlled trials are
available yet that compare the results of both techniques.
However, postoperative morbidity and recurrence rates
seem to be similar between biological and synthetic pros-
theses in nondirty fields. Considering the high costs of
biologic grafts, they are not recommended in these situa-
tions. The use of biologic grafts results in high complica-
tion and recurrence rates in contaminated and dirty fields
but is associated with a high salvage rate of the prosthesis
in cases of infection and potentially offers a 1-stage repair
in these compromised surgical fields. Biologic grafts are
not popular in Europe because of their high costs, and more
convincing evidence of their performance and proper
indication is awaited. The Food and Drug Administration
reported adverse events with the use of biologic grafts that
warrant caution and judicious decision making. Biologic
grafts have not been approved for use in abdominal wall
reconstruction in contaminated fields.73Studies with longer
follow-ups are essential to properly determine the durabil-
ity of biologic grafts given their biodegradable nature.
1. Ho ¨er J, Lawong G, Klinge U, et al. Einflußfaktoren der Narbenhernien-
entstehung: Retrospektive Untersuchung an 2983 laparotomierten
Patienten u ¨ber einen Zeitraum von 10 Jahren. Chirurg 2002;73:478–80.
2. Mudge M, Hughes LE. lncisional hernia: a 10 year prospective study
of incidence and attitudes. Br J Surg 1985;72:70–1.
3. Cassar K, Munro A. Surgical treatment of incisional hernia. Br J Surg
4. Flum DR, Horvath K, Koepsell T. Have outcomes of incisional hernia
repair improved with time? A population-based analysis. Ann Surg
5. Basoglu M, Yildirgan MI, Yilmaz I, et al. Late complications of inci-
sional hernias following prosthetic mesh repair. Acta Chir Belg 2004;
6. Campanelli G, Catena F, Ansaloni L. Prosthetic abdominal wall hernia
repair in emergency surgery: from polypropylene to biological meshes.
World J Emerg Surg 2008;3:33.
7. Slim K, Nini E, Forestier D, et al. Methodological index for non-
randomized studies (minors): development and validation of a new in-
strument. ANZ J Surg 2003;73:712–6.
8. Berard F, Gandon J. Postoperative wound infections: the influence of
ultraviolet irradiation of the operating room and of various other fac-
tors. Ann Surg 1964;160:1–192.
9. SPSS for Windows [computer program]. Rel. 16.0.2. Chicago, IL:
SPSS Inc; 2008.
10. StatsDirect statistical software [computer program]. Version 2.7.8.
Cheshire, England: StatsDirect Ltd; 2008.
11. Alaedeen DI, Lipman J, Medalie D, et al. The single-staged approach
to the surgical management of abdominal wall hernias in contaminated
fields. Hernia 2007;11:41–5.
12. Bellows CF, Albo D, Berger DH, et al. Abdominal wall repair using
human acellular dermis. Am J Surg 2007;194:192–8.
13. Boehmler JH 4th, Butler CE, Ensor J, et al. Outcomes of various tech-
niques of abdominal fascia closure after TRAM flap breast reconstruc-
tion. Plast Reconstr Surg 2009;123:773–81.
14. Buinewicz B, Rosen B. Acellular cadaveric dermis (AlloDerm): a new
alternative for abdominal hernia repair. Ann Plast Surg 2004;52:188–94.
15. Candage R, Jones K, Luchette FA, et al. Use of human acellular der-
mal matrix for hernia repair: friend or foe? Surgery 2008;144:703–9.
16. Diaz JJ Jr, Conquest AM, Ferzoco SJ, et al. Multi-institutional experi-
ence using human acellular dermal matrix for ventral hernia repair in a
compromised surgical field. Arch Surg 2009;144:209–15.
17. Glasberg SB, D’Amico RA. Use of regenerative human acellular tissue
flap breast reconstruction surgery. Plast Reconstr Surg 2006;118:8–15.
18. Gupta A, Zahriya K, Mullens PL, et al. Ventral herniorrhaphy: experi-
ence with two different biosynthetic mesh materials, Surgisis and Al-
loderm. Hernia 2006;10:419–25.
19. Jin J, Rosen MJ, Blatnik J, et al. Use of acellular dermal matrix for
complicated ventral hernia repair: does technique affect outcomes?
J Am Coll Surg 2007;205:654–60.
20. Kim H, Bruen K, Vargo D. Acellular dermal matrix in the management
of high-risk abdominal wall defects. Am J Surg 2006;192:705–9.
21. Kolker AR, Brown DJ, Redstone JS, et al. Multilayer reconstruction of
abdominal wall defects with acellular dermal allograft (AlloDerm) and
component separation. Ann Plast Surg 2005;55:36–41.
22. Lee EI, Chike-Obi CJ, Gonzalez P, et al. Abdominal wall repair using
human acellular dermal matrix: a follow-up study. Am J Surg 2009;
23. Lin HJ, Spoerke N, Deveney C, et al. Reconstruction of complex ab-
dominal wall hernias using acellular human dermal matrix: a single in-
stitution experience. Am J Surg 2009;197:599–603.
24. Maurice SM, Skeete DA. Use of human acellular dermal matrix for ab-
dominal wall reconstructions. Am J Surg 2009;197:35–42.
25. Misra S, Raj PK, Tarr SM, et al. Results of AlloDerm use in abdominal
hernia repair. Hernia 2008;12:247–50.
26. Patton JH Jr, Berry S, Kralovich KA. Use of human acellular dermal
matrix in complex and contaminated abdominal wall reconstructions.
Am J Surg 2007;193:360–3.
27. Scott BG, Welsh FJ, Pham HQ, et al. Early aggressive closure of the
open abdomen. J Trauma 2006;60:17–22.
28. Taner T, Cima RR, Larson DW, et al. Surgical treatment of complex
enterocutaneous fistulas in IBD patients using human acellular dermal
matrix. Inflamm Bowel Dis 2009;15:1208–12.
29. Chavarriaga LF, Lin E, Losken A, et al. Management of complex ab-
dominal wall defects using acellular porcine dermal collagen. Am
30. Catena F, Ansaloni L, Gazzotti F, et al. Use of porcine dermal collagen
graft (Permacol) for hernia repair in contaminated fields. Hernia 2007;
31. Connolly PT, Teubner A, Lees NP, et al. Outcome of reconstructive
surgery for intestinal fistula in the open abdomen. Ann Surg 2008;
32. Hsu PW, Salgado CJ, Kent K, et al. Evaluation of porcine dermal col-
lagen (Permacol) used in abdominal wall reconstruction. J Plast Re-
constr Aesthet Surg 2009;62:1484–9.
33. Loganathan A, Ainslie WG, Wedgwood KR. Initial evaluation of Per-
macol bioprosthesis for the repair of complex incisional and parasto-
mal hernias. Surgeon 2010;8:202–5.
34. Parker DM, Armstrong PJ, Frizzi JD, et al. Porcine dermal collagen (Per-
macol) for abdominal wall reconstruction. Curr Surg 2006;63:255–8.
35. Shaikh FM, Giri SK, Durrani S, et al. Experience with porcine acellular
dermal collagen implant in one-stage tension-free reconstruction of acute
and chronic abdominal wall defects. World J Surg 2007;31:1966–72.
N.J. Slater et al. Biologic grafts for ventral hernia repair229
36. Helton WS, Fisichella PM, Berger R, et al. Short-term outcomes with Download full-text
small intestinal submucosa for ventral abdominal hernia. Arch Surg
37. Ueno T, Pickett LC, de la Fuente SG, et al. Clinical application of por-
cine small intestinal submucosa in the management of infected or po-
tentially contaminated abdominal defects. J Gastrointest Surg 2004;8:
38. Butler CE, Langstein HN, Kronowitz SJ. Pelvic, abdominal, and chest
wall reconstruction with AlloDerm in patients at increased risk for
mesh-related complications. Plast Reconstr Surg 2005;116:1263–75.
39. Raftopoulos I, Courcoulas AP. Outcome of laparoscopic ventral hernia
repair in morbidly obese patients with a body mass index exceeding 35
kg/m2. Surg Endosc 2007;21:2293–7.
40. Sailes FC, Walls J, Guelig D, et al. Synthetic and biological mesh in
component separation: a 10–year single institution review. Ann Plast
41. Schuster R, Singh J, Safadi BY, et al. The use of acellular dermal ma-
trix for contaminated abdominal wall defects: wound status predicts
success. Am J Surg 2006;192:594–7.
42. Pomahac B, Aflaki P. Use of a non-cross-linked porcine dermal scaf-
fold in abdominal wall reconstruction. Am J Surg 2010;199:22–7.
43. Cobb GA, Shaffer J. Cross-linked acellular porcine dermal collagen
implant in laparoscopic ventral hernia repair: case-controlled study
of operative variables and early complications. Int Surg 2005;90:24–9.
44. Eid GM, Mattar SG, Hamad G, et al. Repair of ventral hernias in mor-
bidly obese patients undergoing laparoscopic gastric bypass should not
be deferred. Surg Endosc 2004;18:207–10.
45. Franklin ME Jr, Trevino JM, Portillo G, et al. The use of porcine small
intestinal submucosa as a prosthetic material for laparoscopic hernia
repair in infected and potentially contaminated fields: long-term fol-
low-up. Surg Endosc 2008;22:1941–6.
46. Parra MW, Rodas EB, Niravel AA. Laparoscopic repair of potentially
contaminated abdominal ventral hernias using a xenograft: a case se-
ries. Hernia 2011;15:575–8.
47. Trevin ˜o JM, Franklin ME, Berghoff KR, et al. Preliminary results of
a two-layered prosthetic repair for recurrent inguinal and ventral her-
nias combining open and laparoscopic techniques. Hernia 2006;10:
48. Blatnik J, Jin J, Rosen M. Abdominal hernia repair with bridging acellular
dermal matrix–an expensive hernia sac. Am J Surg 2008;196:47–50.
49. Franklin ME Jr, Gonzalez JJ Jr, Michaelson RP, et al. Preliminary ex-
perience with new bioactive prosthetic material for repair of hernias in
infected fields. Hernia 2002;6:171–4.
50. Franklin ME Jr, Gonzalez JJ Jr, Glass JL. Use of porcine small
intestinal submucosa as a prosthetic device for laparoscopic repair
of hernias in contaminated fields: 2–year follow-up. Hernia 2004;
51. Espinosa-de-los-Monteros A, de la Torre JI, Marrero I, et al. Utiliza-
tion of human cadaveric acellular dermis for abdominal hernia recon-
struction. Ann Plast Surg 2007;58:264–7.
52. Ko JH, Salvay DM, Paul BC, et al. Soft polypropylene mesh, but not
cadaveric dermis, significantly improves outcomes in midline hernia
repairs using the components separation technique. Plast Reconstr
53. Moore M, Bax T, MacFarlane M, et al. Outcomes of the fascial com-
ponent separation technique with synthetic mesh reinforcement for re-
pair of complex ventral incisional hernias in the morbidly obese. Am J
54. Vertrees A, Greer L, Pickett C, et al. Modern management of complex
open abdominal wounds of war: a 5-year experience. J Am Coll Surg
55. Phillips B, Ball C, Sackett D, et al. Oxford Centre for Evidence-based
Medicine - Levels of Evidence [CEBM]. March, 2009. Available at:
http://www.cebm.net/index.aspx?o51025. Accessed October 19, 2010.
56. Muysoms FE, Miserez M, Berrevoet F, et al. Classification of primary
and incisional abdominal wall hernias. Hernia 2009;13:407–14.
57. Hawn MT, Snyder CW, Graham LA, et al. Long-term follow-up of
technical outcomes for incisional hernia repair. J Am Coll Surg
58. Ho KL, Witte MN, Bird ET. 8-ply small intestinal submucosa tension-
free sling: spectrum of postoperative inflammation. J Urol 2004;171:
59. Cornwell KG, Landsman A, James KS. Extracellular matrix biomate-
rials for soft tissue repair. Clin Podiatr Med Surg 2009;26:507–23.
60. Zheng MH, Chen J, Kirilak Y, et al. Porcine small intestine submucosa
(SIS) is not an acellular collagenous matrix and contains porcine
DNA: possible implications in human implantation. J Biomed Mater
Res B Appl Biomater 2005;73:61–7.
61. Trabuco EC, Klingele CJ, Gebhart JB. Xenograft use in reconstructive
pelvic surgery: a review of the literature. Int Urogynecol J Pelvic Floor
62. Forbes SS, Eskicioglu C, McLeod RS, et al. Meta-analysis of random-
ized controlled trials comparing open and laparoscopic ventral and in-
cisional hernia repair with mesh. Br J Surg 2009;96:851–8.
63. de Vries Reilingh TS, Bodegom ME, van Goor H, et al. Autologous tis-
sue repair of large abdominal wall defects. Br J Surg 2007;94:791–803.
64. Antonopoulos IM, Nahas WC, Mazzucchi E, et al. Is polypropylene
mesh safe and effective for repairing infected incisional hernia in renal
transplant recipients? Urology 2005;66:874–7.
65. Birolini C, Utiyama EM, Rodrigues AJ Jr, et al. Elective colonic op-
eration and prosthetic repair of incisional hernia: does contamination
contraindicate abdominal wall prosthesis use? J Am Coll Surg 2000;
66. Geisler DJ, Reilly JC, Vaughan SG, et al. Safety and outcome of use of
nonabsorbable mesh for repair of fascial defects in the presence of
open bowel. Dis Colon Rectum 2003;46:1118–23.
67. Kelly ME, Behrman SW. The safety and efficacy of prosthetic hernia
repair in clean-contaminated and contaminated wounds. Am Surg
68. Machairas A, Liakakos T, Patapis P, et al. Prosthetic repair of incisional
hernia combined with electivebowel operation. Surgeon 2008;6:274–7.
69. McNeeley SG Jr, Hendrix SL, Bennett SM, et al. Synthetic graft place-
ment in the treatment of fascial dehiscence with necrosis and infection.
Am J Obstet Gynecol 1998;179:1430–4.
70. Vix J, Meyer C, Rohr S, et al. The treatment of incisional and abdom-
inal hernia with a prosthesis in potentially infected tissuesda series of
47 cases. Hernia 1997;1:157–61.
71. DiCocco JM, Magnotti LJ, Emmett KP, et al. Long-term follow-up of
abdominal wall reconstruction after planned ventral hernia: a 15-year
experience. J Am Coll Surg 2010;210:686–95.
72. Kaleya RN, Thomas R. Use of a global economic model to analyze the
cost-benefit of AlloDerm in Ventral Hernia repair [LifeCell]. 2005.
Available at: http://www.lifecell.com. Accessed June 25, 2010.
73. Harth KC, Rosen MJ. Major complications associated with xenograft
biologic mesh implantation in abdominal wallreconstruction. Surg
230 The American Journal of Surgery, Vol 205, No 2, February 2013