REVIEW

The inheritance of groin hernia: a systematic review

J. Burcharth • H. C. Pommergaard •

J. Rosenberg

Received: 9 September 2012 / Accepted: 8 February 2013 / Published online: 20 February 2013

� Springer-Verlag France 2013

Abstract

Background Groin hernia has been proposed to be

hereditary; however, a clear hereditary pattern has not been

established yet. The purpose of this review was to analyze

studies evaluating family history and inheritance patterns

and to investigate the possible heredity of groin hernias.

Methods A literature search in the MEDLINE and Em-

base databases was performed with the following search

terms: genetics, heredity, multifactorial inheritance, inher-

itance patterns, sibling relations, family relations, and

abdominal hernia. Only English human clinical or register-

based studies describing the inheritance of groin hernias,

family history of groin hernias, or familial accumulation of

groin hernias were included.

Results Eleven studies evaluating 37,166 persons were

included. The overall findings were that a family history of

inguinal hernia was a significant risk factor for the devel-

opment of a primary hernia. A family history of inguinal

hernia showed a tendency toward increased hernia recur-

rence rate and significantly earlier recurrence. The included

studies did not agree on the possible inheritance patterns

differing between polygenic inheritance, autosomal domi-

nant inheritance, and multifactorial inheritance. Further-

more, the studies did not agree on the degree of penetrance.

Conclusion The literature on the inheritance of groin

hernias indicates that groin hernia is most likely an inher-

ited disease; however, neither the extent of familial accu-

mulation nor a clear inheritance pattern has yet been found.

In order to establish whether groin hernias are accumulated

in certain families and to what extent, large register studies

based on hernia repair data or clinical examinations are

needed.

Groin hernia repair (inguinal and femoral hernia) is among

the most commonly performed gastrointestinal surgical

procedures [1]. Emergency groin hernia surgery is associ-

ated with increased mortality, increased patient-related

morbidity, and increased hospital stay compared with

elective groin hernia procedures [2, 3]. Identifying patients

at high risk of developing groin hernia would therefore

provide the possibility of timely elective surgical inter-

vention, thus reducing the rate of emergency procedures. It

could also potentially make way for individualized surgical

methods in the future.

Keywords Inguinal hernia � Groin hernia � Risk factor �Inheritance � Systematic review

Introduction

Earlier proposed risk factors for developing groin hernias

are, for example, male gender [4], old age [5], patent

processus vaginalis [6], low body mass index [7], and high

intraabdominal pressure [8]. Knowledge of systemic col-

lagen diseases, such as cutis laxa [9], Marfan syndrome

[10], and Ehlers–Danlos syndrome [11], has revealed a

link to hernia formation. In particular, systemic collagen

subtype imbalance [12] and altered extracellular matrix

composition/degradation [13, 14] correlate to increased

occurrence of primary and recurrent hernia. Furthermore,

positive family history (i.e., the presence of hernia in

directly related close family members) has been proposed

as a predictor for development [15] as well as an increased

risk of recurrence of primary hernia [16].

J. Burcharth (&) � H. C. Pommergaard � J. Rosenberg

Department of Surgery, Center for Perioperative Optimization,

Herlev Hospital, University of Copenhagen, Herlev Ringvej 75,

2730, DK, Copenhagen, Denmark

e-mail: jakobburcharth@gmail.com

123

Hernia (2013) 17:183–189

DOI 10.1007/s10029-013-1060-4

The purpose of this review was to analyze studies

evaluating the impact of positive family history and

inheritance patterns and thereby investigate the possible

heredity of groin hernias.

Methods

Literature search

Using the PRISMA [17, 18] guidelines, a systematic lit-

erature search was performed in February 2012 in MED-

LINE and Embase. To supply the strategic search, a

reference search in the obtained articles0 reference list was

done, as not all relevant studies are expected to be returned

only by relying on systematic database searches [19].

The aim of the literature search was to identify studies

describing the inheritance patterns of groin hernia and the

impact of positive family history and familial accumulation

of groin hernia.

The literature search in the MEDLINE database utilized

the Advanced Search feature with the following search terms:

genetics, heredity, multifactorial inheritance, inheritance

patterns, sibling relations, family relations, and abdominal

hernia as All Field and MeSH terms. The literature search in

Embase used the Multifield Advanced Search Function with

the same search terms. We did not apply further filtering in

order to enhance the possibilities of the search strategy.

Study selection criteria

Only human clinical or register-based studies describing

the inheritance of groin hernias, positive family history of

groin hernias, or familial accumulation of groin hernias

were included. Only studies published in English were

considered for inclusion.

The primary study outcome for this review was inheri-

tance patterns of groin hernia. The secondary study out-

come was determination of risk estimates odds ratio (OR),

relative risk (RR) of positive family history of groin her-

nias as a risk factor for groin hernia development. Studies

not evaluating the above mentioned (e.g., studies focusing

on specific gene-finding techniques) and case reports were

excluded. For the study selection process, see Fig. 1.

Initial abstract screening and full-text assessment

Titles and abstracts were assessed for eligibility by two

reviewers according to the study selection criteria. Any

uncertainties between the reviewers were settled by dis-

cussion until consensus. For the abstracts possibly suited

for inclusion in this systematic review, full manuscripts

were obtained and evaluated in detail.

Data extraction

The following were extracted from the included studies:

study design, study aims, population (patient material,

number, subgroups, and demographics), hernia type inves-

tigated, results, inheritance patterns when possible, risk

estimates (OR/RR in absolute numbers), and study con-

clusions. Data were extracted directly from the included

studies and discussed by both reviewers. Furthermore,

studies were evaluated for limitations and possible bias.

Results

A total of 1,023 possible studies were identified, and after

doublets were removed, the search strategy resulted in 712

studies possible for inclusion (Fig. 1). After screening of

title and abstract, 30 full-text manuscripts were selected

and assessed for eligibility. After application of study cri-

teria, 11 studies evaluating a total of 37,166 persons

remained, which were included in this systematic review

(Fig. 1). All of the included studies evaluated inguinal

hernias and none evaluated femoral hernias (Table 1).

Seven studies evaluated primary hernias [15, 16, 20–24],

whereas the remaining four studies evaluated both primary

and recurrent hernias [25–28]. Nine studies determined risk

estimates of a positive family history on the development

of an inguinal hernia. Two studies determined possible

inheritance patterns of inguinal hernias [23, 24].

Positive family history (Table 1)

Six studies evaluated the effect of a positive family history

in both adults and children including a total of 28,746

persons [15, 16, 20, 23, 25, 26]. However, the majority of

patients arise from a single prevalence study simply reg-

istering persons with self-reported first-degree family

members with hernias [20], leaving 1,338 persons from the

other clinical studies. The overall findings of these studies

were that a positive family history of inguinal hernia was a

significant risk factor for the development of a primary

hernia, with the highest risk being a RR 8.35 (CI 95 %

4.72–14.76, p \ 0.01) between male family members [15].

Moreover, a positive family history showed a tendency

toward a higher recurrence rate with an OR 8.43 (CI 95 %

0.91–78.40, p = 0.06) [25] and significantly earlier recur-

rence after the primary procedure [16].

Two studies evaluated the effects of a positive family

history in children [21, 24]. It was found that mothers and

girls more often were affected than mothers and sons and

that this effect was most pronounced when the daughters

had bilateral hernias [21]. Furthermore, it was shown that

all other first-degree relatives to a child with an inguinal

184 Hernia (2013) 17:183–189

123

hernia had an increased relative risk [24]. The studies

showed that girls with sisters that had been operated for

inguinal hernia had a significantly increased risk of devel-

oping a hernia themselves of RR 17.8 (CI 95 % 6.9–46.3).

Twin studies (Table 1)

Two studies examined the hernia occurrence between

monozygotic (MZ) and dizygotic (DZ) twins and included

a total of 2,861 twin pairs [27, 28]. One study found that

MZ twins did not have an increased occurrence of inguinal

hernia compared with DZ twins [27], whereas the other

study found that MZ twins had a significantly higher fre-

quency of hernias than DZ and concluded that the differ-

ence was related to genetic factors [28]. Both of these twin

studies were large in size; however, the largest of the

studies did not specify what types of hernia that were

included in the study [28].

Inheritance patterns and penetrance (Table 1)

The studies evaluating inguinal hernia inheritance patterns

did not agree. Polygenic inheritance [21], autosomal dom-

inant with reduced penetrance [23], and multifactorial

inheritance [24] have been suggested. No studies have

reported indications of inguinal hernias being inherited

through simple inheritance patterns. Common for the

studies that addressed penetrance was a reporting of it as a

secondary finding despite its importance for the subject.

Discussion

This systematic review found that a positive family history

was a significant risk factor for development of primary

inguinal hernia. The suggested inheritance patterns in the

included studies differed between autosomal dominant,

Fig. 1 Flow diagram of study

selection

Hernia (2013) 17:183–189 185

123

Ta

ble

1O

utc

om

eso

fth

ein

clu

ded

stu

die

s

Stu

dy

Po

pu

lati

on

,H

ern

ia

typ

e

Res

ult

sL

imit

atio

ns

Co

ncl

usi

on

s

Inh

erit

ance

Co

nco

rdan

ceR

isk

Mar

shal

l

etal

.[2

8]

2,5

37

twin

pai

rs

(ag

e2

–7

0y

ears

).

Her

nia

typ

e:n

s

ns

Mo

reM

Z

twin

sw

ith

her

nia

s

than

DZ

twin

s

(p=

0.0

2)

ns

Tw

inzy

go

sity

loo

sely

det

erm

ined

by

qu

esti

on

sto

rela

tiv

es(i

ncl

usi

on

bia

s,

reca

llb

ias)

.Z

yg

osi

tyte

stin

gp

erfo

rmed

on

44

twin

pai

rs

An

yd

iffe

ren

cein

con

cord

ance

reli

edo

n

gen

etic

fact

ors

Bak

win

etal

.[2

7]

32

4tw

inp

airs

(ag

e

5–

18

yea

rs).

Her

nia

typ

e:II

H

ns

No

dif

fere

nce

bet

wee

n

MZ

and

DZ

twin

s

ns

Inte

rvie

w-b

ased

dat

afr

om

mo

ther

s(r

ecal

l

bia

s).T

win

zyg

osi

tyd

eter

min

edp

artl

yb

y

clin

ical

exam

inat

ion

No

gen

etic

bas

isfo

rh

ern

ia

dev

elo

pm

ent

inch

ild

ren

Saw

agu

chi

etal

.[2

1]

1,7

23

chil

dre

n

(ag

e0

–1

2y

ears

).

Her

nia

typ

e:II

H

Mo

rep

ron

ou

nce

dfr

om

mo

ther

to

dau

gh

ter

than

mo

ther

toso

n

(p\

0.0

5)

ns

Bil

ater

alh

ern

ias

in

chil

dre

nco

rrel

ated

to

mo

ther

sw

ith

her

nia

s

(p\

0.0

5)

Inte

rvie

w-b

ased

dat

afr

om

par

ents

(rec

all

bia

s).

Fam

ily

dat

are

trie

ved

fro

mh

alf

of

the

incl

ud

edch

ild

ren

.N

oco

ntr

ol

gro

up

,

bac

kg

rou

nd

freq

uen

cies

of

IHb

ased

on

assu

mp

tio

ns

Po

lyg

enic

inh

erit

ance

wit

h

thre

sho

ld.

Mo

reli

kel

yth

at

fem

ales

hav

ep

osi

tiv

e

fam

ily

his

tory

of

her

nia

than

mal

es

Cze

izel

etal

.[2

2]

70

7p

aren

tso

f

chil

dre

nw

ith

CIH

.H

ern

ia

typ

e:C

IH

Fat

her

s/m

oth

ers

toch

ild

ren

(RR

2/R

R5

).B

roth

ers/

sist

ers

of

fem

ale

case

s(R

R3

.4/R

R7

.1).

Bro

ther

s/si

ster

so

fm

ale

case

s

(RR

3.6

/RR

5.3

)

ns

ns

Inte

rvie

w-b

ased

dat

afr

om

par

ents

(rec

all

bia

s).

Sta

tist

ical

sig

nifi

can

cen

ot

stat

ed

Mu

ltif

acto

rial

do

min

ant

inh

erit

ance

wit

hth

resh

old

.

Mo

ther

sm

ore

affe

cted

than

fath

ers.

Par

ents

less

affe

cted

than

sib

lin

gs

Go

ng

etal

.

[23]

34

0p

erso

ns

(31

9

mal

es,

21

fem

ales

).H

ern

ia

typ

e:II

H

Dir

ect

mal

eto

mal

etr

ansm

issi

on

in5

2%

of

fam

ilie

s

ns

ns

No

con

tro

lg

rou

p.

No

bac

kg

rou

nd

po

pu

lati

on

inci

den

ceo

fh

ern

ias.

No

kn

ow

led

ge

of

spo

nta

neo

us

her

nia

occ

urr

ence

inp

op

ula

tio

n

Au

toso

mal

do

min

ant

inh

erit

ance

wit

hre

du

ced

pen

etra

nce

Lie

met

al.

[26]

72

fem

ale

pat

ien

ts

(12

9co

ntr

ols

).

Her

nia

typ

e:IH

ns

ns

Po

siti

ve

fam

ily

his

tory

inp

atie

nts

com

par

ed

wit

hco

ntr

ol

gro

up

(OR

4.3

(CI

95

%

1.9

–9

.7))

Inte

rvie

w-b

ased

dat

a(r

ecal

lb

ias)

.T

he

deg

ree

the

rela

tiv

esh

adto

the

pat

ien

ts

no

td

efin

ed.N

ot

com

ple

tely

mat

ched

case

and

con

tro

lg

rou

ps

Po

siti

ve

fam

ily

his

tory

of

ing

uin

alh

ern

iais

ari

sk

fact

or

for

dev

elo

pm

ent

of

ing

uin

alh

ern

iain

fem

ales

Ak

inet

al.

[20]

27

,40

8m

ales

(ag

e

20

–2

2).

Her

nia

typ

e:IH

ns

ns

Fam

ily

his

tory

:(2

0.6

%

rep

ort

edfi

rst-

deg

ree

rela

tiv

esw

ith

her

nia

)

Inte

rvie

w-b

ased

dat

a(r

ecal

lb

ias)

.N

o

con

tro

lg

rou

p.

No

po

pu

lati

on

pre

val

ence

of

IHfo

rco

mp

aris

on

Hig

hfr

equ

ency

of

po

siti

ve

fam

ily

his

tory

amo

ng

IH

pat

ien

ts

Jon

eset

al.

[24]

2,2

68

chil

dre

n

(1,9

21

mal

es,

34

7fe

mal

es)

(ag

e0

–5

yea

rs).

Her

nia

typ

e:C

IH

Bro

ther

so

fm

ale

case

and

fem

ale

case

s(R

R5

.8,

RR

4.3

).S

iste

ro

f

mal

eca

sean

dfe

mal

eca

se(R

R

3.7

,R

R1

7.8

)

ns

ns

Mu

ltif

acto

rial

inh

erit

ance

wit

hth

resh

old

Jun

ge

etal

.

[25]

14

2p

atie

nts

(ag

e

18

–7

9y

ears

),

(91

.2%

mal

es).

Her

nia

typ

e:IH

ns

ns

Po

siti

ve

fam

ily

his

tory

inp

atie

nts

(OR

8.4

3

(CI

95

%0

.91

–7

8.4

0)

Inte

rvie

w-b

ased

fam

ily

dat

a(r

ecal

lb

ias)

.

No

con

tro

lg

rou

p.

No

td

efin

edth

ed

egre

e

the

rela

tiv

esh

adto

the

pat

ien

ts

Po

siti

ve

fam

ily

his

tory

fact

or

for

IH

186 Hernia (2013) 17:183–189

123

polygenic and multifactorial inheritance; however, all

suggested inheritance patterns were complex and no stud-

ies suggested simple monogenic inheritance. Neither did

the included studies agree on the degree of penetrance.

The included studies in this review are heterogenic and

differ somewhat in design, size, aim, and outcome. In five

of the included studies, positive familial history of hernia

or inheritance of hernia was typically a secondary finding

[15, 16, 20, 25, 26]. All of the included studies except one

[24] had a degree of recall bias, since recording of hernia

occurrence was based on interviews rather than actual

surgical data, register-based data, or clinical examinations.

Furthermore, a general problem in all of the studies except

three [15, 24, 26] was the lack of a comparative control

group, which reduced the possibility of transferring the

results to a wider demographic population. Some studies

lacked a clear definition of a positive family history

[15, 16, 23, 26]. This reduces the possibilities of deter-

mining the degree of inheritance, since it could not be

extracted from the studies whether affected relatives were

directly related (first degree) or more distantly related,

which may greatly complicate interpretation of the results.

Some studies were unclear in the calculation of the degree

of inheritance from the data or did not state whether results

were significant [16, 22, 25, 28]. In two of the included

studies [21, 26], it was not stated whether the data were

based on clinical examinations or surgical procedures, in

which case clinical observer bias cannot be excluded.

In the two included twin studies, the twin zygosity was

established by blood group analysis on a small subgroup of

the entire included study population and by opinions from

relatives, as to whether the siblings were MZ or DZ twins.

Thus, these methods may be neither rigorous nor consistent

enough to produce clear conclusions [27, 28]. However, in

the one study finding a higher concordance between MZ

twins compared with DZ twins, the results are interesting

since it is given that MZ twins have identical genomes, and

the fact that a larger fraction of MZ twins develops hernias

compared with DZ twins strongly points toward a genetic

aspect [28].

Besides the included studies in this review, a few case

studies have reported families with a hereditary predispo-

sition to inguinal hernias [29–34]. Together with the

studies in this review, the two main other studies suggested

that inheritance patterns are autosomal dominant inheri-

tance with incomplete penetrance and male influence

[23, 29, 30, 32, 33] and polygenic multifactorial inheri-

tance with a threshold [21, 22, 24, 34]. The strongest link

has been found between females with hernias; however, a

definite and clear inheritance pattern has not yet been

found. It is most likely that a possible inheritance pattern of

groin hernia is complex, and the level of penetrance of the

involved genes may play a major role. No studies haveTa

ble

1co

nti

nu

ed

Stu

dy

Po

pu

lati

on

,H

ern

ia

typ

e

Res

ult

sL

imit

atio

ns

Co

ncl

usi

on

s

Inh

erit

ance

Co

nco

rdan

ceR

isk

Lau

etal

.

[15]

70

9m

ale

pat

ien

ts

(ag

e5

2–

78

)(7

09

mal

eco

ntr

ols

).

Her

nia

typ

e:IH

ns

ns

Po

siti

ve

fam

ily

his

tory

risk

fact

or

for

IH

dev

elo

pm

ent

(p\

0.0

1,

RR

8.3

5

(CI

95

%)

4.7

2–

14

.76

)

Inte

rvie

w-b

ased

fam

ily

dat

a(r

ecal

lb

ias)

.

No

td

efin

edth

ed

egre

eth

ere

lati

ves

had

toth

ep

atie

nts

Po

siti

ve

fam

ily

his

tory

risk

fact

or

for

pri

mar

yin

gu

inal

her

nia

dev

elo

pm

ent

Jan

sen

etal

.[1

6]

75

pat

ien

ts(a

ge

18

–7

4).

Her

nia

typ

e:IH

ns

ns

Po

siti

ve

fam

ily

his

tory

risk

fact

or

for

earl

ier

on

set

of

recu

rren

ce

Inte

rvie

w-b

ased

fam

ily

dat

a(r

ecal

lb

ias)

Pat

ien

tsw

ith

afa

mil

yh

isto

ry

hav

ere

curr

ence

ata

yo

un

ger

age

Ns

no

tst

ated

,M

Zm

on

ozy

go

te,D

Zd

izy

go

te,C

IHco

ng

enit

alin

gu

inal

her

nia

,II

Hin

dir

ect

ing

uin

alh

ern

ias,

IHin

gu

inal

her

nia

,R

Rre

lati

ve

risk

,O

Ro

dd

sra

tio

,C

I9

5%

95

%co

nfi

den

cein

terv

al

Hernia (2013) 17:183–189 187

123

reported on possible hereditary predisposition of other

types of groin hernia (e.g., femoral hernias) than inguinal

hernias, most likely due to their rarity compared with

inguinal hernias.

In determining a possible inheritance pattern of a disease

as common as inguinal hernias, several elements need to be

addressed. Besides distinguishing between inguinal and

femoral hernias, it may be relevant to separate analyses of

inguinal hernias for direct and indirect inguinal hernias,

since the two hernia types might have different etiologies.

It is known that children predominantly develop indirect

inguinal hernias, whereas adults have both direct and

indirect inguinal hernias [35]. It has been hypothesized that

a direct inguinal hernia is caused by a local collagen

weakness, whereas the indirect hernia is due to a congenital

malformation (persistent processus vaginalis) [36, 37]. This

possible difference between the indirect and the direct

inguinal hernia may suggest that the children and the adult

hernia have different etiologies. The included studies in

this review are based on data from children as well as

adults and include both direct and indirect inguinal hernias

in their datasets, which may reduce the possibility of

retrieving a common conclusion on inheritance pattern

among the studies. As seen in Table 1, gender seems to be

an important factor for the development of groin hernias.

In general, contradictory results were seen among the

included studies regarding gender influence on the risk of

developing an inguinal hernia. Some studies found that

female members of affected families had higher risks than

males [21, 22, 24, 26], whereas other studies found high

risk among males for developing inguinal hernias [15, 23,

25]. Due to the heterogeneity of the study designs as well

as the disagreement of the results, no final conclusion

regarding the gender influence can be made on the basis of

the included studies. Furthermore, it is important to be

aware of the amount of male and female cases in the

selected families, since inguinal hernias are more common

among males. Therefore, families with many males may be

influenced by a high spontaneous frequency of inguinal

hernias. Finally, it should be clarified if any of the affected

family members suffered from a collagen disease that may

predispose to hernias. The fact that the included studies

suggested different complex possible inheritance patterns

and varying degrees of penetrance points out the possible

complexity of this area. The fact that inguinal hernias

might are inherited with reduced or varying penetrance

greatly increases the requirements for study designs and

study size, since the possibility of locating a strong familial

connection reduces with low genetic penetrance.

In finding a possible positive family history of groin

hernia, several factors need to be considered. The design of

the study should be as concise and methodically strict

as possible. Preferably, it should be a large-scale study,

including persons over a geographically wide area so that

the data are representative of the general population. Sev-

eral of the studies lack this element. Furthermore, a precise

definition of a positive family history should be used. The

authors recommend that the definition should be restricted

to include only first-degree family members. The studies

should also be based on incidence data rather than preva-

lence data, given that there otherwise will be a risk of

misjudging the potential familial relation. Thus, the risk

estimates from prevalence data are limited to the study

period only, whereas lifetime risk is evaluated in incidence

data. Finally, the data should be based on safe measureable

hernia data such as operation charts instead of interview

data or clinical examinations, in order to eliminate possible

recall bias and clinical observer bias. The strongest of the

included studies make use of register-based repair data,

however, only focusing on indirect congenital inguinal

hernias in children aged 0–5 years and their siblings [24].

None of the other included studies make use of register-

based data.

The possible determination of hernia inheritance and

thereby identification of high-risk patients may have several

clinical implications. It is known that up to 5 % of inguinal

hernias and 40 % of femoral hernias require acute surgery

due to hernia incarceration [2, 3]. Mortality rates in elective

groin hernia procedures are reported to be less than 0.5 %

[38], whereas emergency groin hernia repairs are associated

with a mortality rate of 2–8 % [39, 40]. A possible method

for identification of high-risk patients would allow timely

control and intervention before the hernia is presented

acutely. By establishing patients at high risk and possible

inheritance patterns, it may be possible to reduce mortality

and complications by having particular focus on these

patients. From a clinical point of view, knowledge of these

high-risk patients may potentially result in different treat-

ment strategies, for example, with the use of larger meshes

and more frequent postoperative follow-up, since patients

with a positive family history have a documented tendency

of overall higher recurrence rate [25] and a significantly

higher risk of earlier recurrence [16].

Conclusion

In conclusion, the literature on the inheritance of groin

hernias indicates that groin hernias most probably are

inherited. However, due to the heterogeneity of the inclu-

ded studies, no final conclusion can be made at this point,

on either the extent of familial accumulation or an inheri-

tance pattern. In order to establish whether groin hernias

are hereditary and to what extent, large register studies

based on hernia repair data or clinical examinations are

needed. Furthermore, larger-scale studies examining the

188 Hernia (2013) 17:183–189

123

inguinal hernia concordance of MZ twins compared with

DZ twins should be performed.

Conflict of interest None.

References

1. Kingsnorth A, LeBlanc K (2003) Hernias: inguinal and inci-

sional. Lancet 362:1561–1571

2. Dahlstrand U, Wollert S, Nordin P, Sandblom G, Gunnarsson U

(2009) Emergency femoral hernia repair: a study based on a

national register. Ann Surg 249:672–676

3. Nilsson H, Stylianidis G, Haapamaki M, Nilsson E, Nordin P

(2007) Mortality after groin hernia surgery. Ann Surg 245:656–

660

4. Phillips W, Goldman M (2004) Groin Hernia. In: Raftery J, Mant

J, Simpson S (eds) Stevens A. Radcliffe publ, Health care needs

assessment, pp 671–721

5. Ruhl CE, Everhart JE (2007) Risk factors for inguinal hernia

among adults in the US population. Am J Epidemiol 165:1154–

1161

6. van Veen RN, van Wessem KJP, Halm JA, Simons MP, Plaisier

PW, Jeekel J, Lange JF (2007) Patent processus vaginalis in the

adult as a risk factor for the occurrence of indirect inguinal

hernia. Surg Endosc 21:202–205

7. Rosemar A, Angeras U, Rosengren A (2008) Body mass index

and groin hernia: a 34-year follow-up study in Swedish men. Ann

Surg 247:1064–1068

8. Ponka J (1980) Hernias of the abdominal wall. WB Saunders,

Philadelphia, pp 264–273

9. Ringpfeil F (2005) Selected disorders of connective tissue:

pseudoxanthoma elasticum, cutis laxa, and lipoid proteinosis.

Clin Dermatol 23:41–46

10. Pyeritz RE, McKusick VA (1979) The Marfan syndrome: diag-

nosis and management. N Engl J Med 300:772–777

11. Liem MS, van der Graaf Y, Beemer FA, van Vroonhoven TJ

(1997) Increased risk for inguinal hernia in patients with Ehlers-

Danlos syndrome. Surgery 122:114–115

12. Henriksen N, Yadete DH, Sorensen LT, Agren MS, Jorgensen LN

(2011) Connective tissue alteration in abdominal wall hernia. Br J

Surg 98:210–219

13. Abrahamson J (1998) Etiology and pathophysiology of primary

and recurrent groin hernia formation. Surg Clin North Am

78:953–972

14. Bellon JM, Bajo A, Ga-Honduvilla N, Gimeno MJ, Pascual G,

Guerrero A et al (2001) Fibroblasts from the transversalis fascia

of young patients with direct inguinal hernias show constitutive

MMP-2 overexpression. Ann Surg 233:287–291

15. Lau H, Fang C, Yuen WK, Patil NG (2007) Risk factors for

inguinal hernia in adult males: a case-control study. Surgery

141:262–266

16. Jansen PL, Klinge U, Jansen M, Junge K (2009) Risk factors for

early recurrence after inguinal hernia repair. BMC Surg 9:18

17. Moher D, Liberati A, Tetzlaff J, Altman DG (2009) Preferred

reporting items for systematic reviews and meta-analyses: the

PRISMA statement. PLoS Med 21(6):e1000097

18. Liberati A, Altman DG, Tetzlaff J, Mulrow C, Gøtzsche PC,

Ioannidis JPA et al (2009) The PRISMA statement for reporting

systematic reviews and meta-analyses of studies that evaluate

health care interventions: explanation and elaboration. J Clin

Epidemiol 62:e1–e34

19. Greenhalgh T, Peacock R (2005) Effectiveness and efficiency of

search methods in systematic reviews of complex evidence: audit

of primary sources. BMJ 331:1064–1065

20. Akin ML, Karakaya M, Batkin A, Nogay A (1997) Prevalence of

inguinal hernia in otherwise healthy males of 20 to 22 years of

age. J R Army Med Corps 143:101–102

21. Sawaguchi S, Matsunaga E, Honna T (1975) A genetic study on

indirect inguinal hernia. Jpn J Hum Genet 20:187–195

22. Czeizel A, Gardonyi J (1979) A family study of congenital

inguinal hernia. Am J Med Genet 4:247–254

23. Gong Y, Shao C, Sun Q, Chen B, Jiang Y, Guo C et al (1994)

Genetic study of indirect inguinal hernia. J Med Genet 31:187–

192

24. Jones ME, Swerdlow J, Griffith M, Goldacre MJ (1998) Risk of

congenital inguinal hernia in siblings: a record linkage study.

Paediatr Perinat Epidemiol 12:288–296

25. Junge K, Rosch R, Klinge U, Schwab R, Peiper C, Binnebosel M

et al (2006) Risk factors related to recurrence in inguinal hernia

repair: a retrospective analysis. Hernia 10:309–315

26. Liem MS, van der Graaf Y, Zwart RC, Geurts I, van Vroonhoven

TJ (1997) Risk factors for inguinal hernia in women: a case-

control study. The Coala Trial Group. Am J Epidemiol 146:721–

726

27. Bakwin H (1971) Indirect inguinal hernia in twins. J Pediatr Surg

6:165–168

28. Marshall AG, Hutchinson EO, Honisett J (1962) Heredity in

common diseases. A retrospective survey of twins in a hospital

population. BMJ 1:1–6

29. West L (1936) Two pedigrees showing inherited predisposition to

hernia. J Hered 27:449–455

30. Montague M (1942) A case of familial inheritance of oblique

inguinal hernia. J Hered 33:355

31. Akbulut S, Cakabay B, Sezgin A (2010) A familial tendency for

developing inguinal hernias: study of a single family. Hernia

14:431–434

32. Weimer BR (1949) Congenital inheritance of inguinal hernia.

J Hered 40:219

33. Smith M (1965) Familial inguinal hernia. Surgery 57:809–812

34. Carter CO (1969) Genetics of common disorders. Br Med Bull

25:52–57

35. Ein SH, Njere I, Ein A (2006) Six thousand three hundred sixty-

one pediatric inguinal hernias: a 35-year review. J Pediatr Surg

41:980–986

36. Wagh PV, Leverich AP, Sun CN, White HJ, Read RC (1974)

Direct inguinal herniation in men: a disease of collagen. J Surg

Res 17:425–433

37. van Wessem KJP, Simons MP, Plaisier PW, Lange JF (2003) The

etiology of indirect inguinal hernias: congenital and/or acquired?

Hernia 7:76–79

38. Bay-Nielsen M, Kehlet H, Strand L, Malmstrøm J, Andersen FH,

Wara P et al (2001) Quality assessment of 26,304 herniorrhaphies

in Denmark: a prospective nationwide study. Lancet 358:1124–

1128

39. Kjaergaard J, Bay-Nielsen M, Kehlet H (2010) Mortality

following emergency groin hernia surgery in Denmark. Hernia

14:351–355

40. Alani A, Page B, O’Dwyer PJ (2006) Prospective study on the

presentation and outcome of patients with an acute hernia. Hernia

2006:62–65

Hernia (2013) 17:183–189 189

123