Study reference

Study characteristics

Patient characteristics

Intervention (I)

Comparison / control (C)

Follow-up

Outcome measures and effect size

Comments

Sauerlan d, 2011

Cochrane SR and meta-analysis of RCT’s

Literature search up to july 2010

A: Ascensio, 2009

B: Barbaros, 2006

C: Buunen, 2010

D: Carbajo, 1999

E: Itani, 2010

F: Misra, 2006 G: Moreno- Egea, 2002

H: Navarra, 2007

I: Olmi, 2007

J: Pring, 2008

Study design: A: open RCT B: RCT

C: RCT D: RCT E: RCT

F: RCT

Inclusion criteria SR:

RCT’s, which compare laparoscopic with open repair (suture or mesh) in

patients with

ventral or incisional

hernia or both. Studies were included irrespective of language, publication status, or sample size.

Exclusion criteria SR: Quasi- randomized trials

10 studies included

Describe intervention: laparoscopic technique

A: 3 ports, ePTFE mesh,

3 cm overlap, transfascial sutures and helical tacks

B: 3 ports, ePTFE, HA- CMC coated

polypropylene meshes or polyurethane

and polyester meshes,

≥3 cm overlap, non- absorbable transfascial sutures and titanium tackers.

C: Not reported (abstract only)

D: 3 ports, PTFE mesh, transfascial sutures and helical tacks.

E: 3 ports, PTFE mesh,

≥3 cm overlap,

transfixation

sutures (every 6 cm) and tacks (in between). F: 3 ports,

polypropylene mesh, 3

- 5cm overlap, tacks

Describe control: conventional method= open repair (suture or mesh)

A: Standard

polypropylene mesh in Rives/Stoppa sublay technique or onlay technique

B: Polypropylene mesh, onlay, 5 cm overlap, onlay, non-absorbable sutures.

C: Not reported (abstract only)

D: Polypropylene mesh, sublay

E: Polypropylene mesh, onlay with component separation, 3 cm overlap

F: Polypropylene mesh, sublay, 3 - 5cm overlap, non-absorbable sutures G: Polypropylene mesh, sublay, overlap > 3cm H: Polypropylene mesh,

sublay, overlap 4 - 5 cm

End-point of follow-up: Recurrence (mean)

A: 12 months

B: 18 months in laparoscopic group and 20 months in open repair group

D: 27 months

E: 24 months

F: 13 months

G: 39 months

H: 6 months

I: 24 months

J: 27.5 months

For how many participants were no complete outcome data available?

A: No risk of bias according to authors. 3 patients were excluded from the analysis, because they withdrew consent (n= 2) or intra- operative hernia size was

Outcome measure-1 Defined as Hernia recurrence

Effect measure: RR (95% CI):

A: 1.24 (0.30 to 5.17)

B: 0.33 (0.01 to 7.78)

D: 0.20 (0.01 to 4.00)

E: 1.24 (0.30 to 5.17)

F: 1.88 (0.18 to 19.63)

G: Not estimable

H: Not estimable

I: 2.00 (0.18 to 21.64)

J: 0.80 (0.05 to 12.14)

Pooled effect (random effects model): 1.22 (95%

CI 0.62 to 2.38) favoring conventional Heterogeneity (I2): 0%

Outcome measure-2 Defined as acute pain

Effect measure: Mean difference (95% CI):

A: 0.48 (-0.40 to 1.36)

B: -0.08 (-1.52 to 1.36)

 Author’s conclusions: The short-term results of laparoscopic repair in ventral hernia are promising. In spite of the risks of adhesiolysis, the technique is safe. Nevertheless, long-term follow-up is needed in order to elucidate whether laparoscopic repair of ventral/ incisional hernia is efficacious.

Level of evidence: GRADE

1. Matig
2. Laag
3. Laag
4. Matig
5. Matig

Sensitivity analyses: Learning curve bias for hernia recurrence

Pooled effect with learning curve bias (studies B and D) (random

effects model): 0.25 (95%

G: RCT H: RCT I: RCT J: RCT

Setting and Country:

A: monocentric B: multicentric C: multicentric D: monocentric E: multicentric F: monocentric G: monocentric H: monocentric I: monocentric J: monocentric

Source of funding: German Ministry of Education and Research, Germany

Important patient characteristics at baseline:

A: incisional size

> 5 cm < 15 cm B: primary and incisional (incl. parastomal), size > 3 cm

C: Primary and incisional, size > 3 cm < 15cm

D: Primary and incisional, size > 80 cm2

E: Incisional (“Ventral incisional hernias (VIHs) after

laparotomy”)

F: Primary and incisional, size > 80 cm2

G: Spigelian, all sizes

H: Incisional, size 3-12 cm

I: Incisional, all sizes

J: Primary or incisional, size > 3 cm

G: either by totally extraperitoneal or by laparoscopic approach, 3 ports, polypropylene mesh in TEP and composite mesh, to overlap the defect widely, stapling (TEP) or transfascial sutures with helical tacks

H: 3 ports, ePTFE mesh or polypropylene- polydioxanone, 5 cm overlap, non- absorbable sutures

I: 3 ports, composite mesh, 4 to 5 cm overlap, tacks

J: 3 or 4 ports, PTFE

mesh, overlap 3 - 4 cm, transfascial sutures and helical tacks

I: Polypropylene mesh, sublay, nonabsorbable separate stiches

J: PTFE mesh, placed intraperitoneally, sutures

<5 cm. It is unclear to which group these patients

were initially randomised Those instances, where outcome data were missing, are clearly described.

B: No losses to follow-up mentioned.

C: 14 patients were excluded for various reasons. 7 patients

were converted to open surgery but analysed according to ITT principle D: No losses to follow-up mentioned.

E: The primary analysis was based on a modified intention-to- treatpopulation. In this analysis, patients who underwent surgery and had at least 1 follow-up visit were included. Two sensitivity

analyses based on all the randomized patients were performed”. Of the initially randomized sample (n= 162), a total of

16 (10%) had to be excluded from analysis. All 16 patients were excluded,

F: -0.10 (-1.19 to 0.99)

J: 0-0.22 (-1.28 to 0.83)

Pooled effect (random effects model): 0.09 (95%

CI -0.45 to 0.62), p=0.75

favoring conventional Heterogeneity (I2): 0%

Outcome measure-2 Defined as chronic pain

Effect measure: Mean difference (95% CI):

A: 0.44 (-0.24 -1.11),

p=0.11, favouring laparoscopic

No pooled effect (1 study)

Outcome measure-4a Defined as local infection (irregardless of severity)

Effect measure: RR (95% CI):

A: Not estimable

B: 0.25 (0.03 to 2.07)

C: 0.50 (0.18 to 1.41)

D: 0.14 (0.01 to 2.65)

E: 0.22 (0.08 to 0.62)

F: 0.18 (0.04 to 0.76)

G: Not estimable

H: 0.33 (0.01 to 7.45)

I: 0.14 (0.02 to 1.14)

J: 0.20 (0.02 to 1.67)

CI 0.03 to 2.23), p=0.22

favoring laparoscopic Heterogeneity (I2): 0%

Pooled effect no information on learning curve bias (studies A, G, H, I) (random effects model): 1.44 (95% CI 0.62

to 2.38), p=0.49 favoring conventional Heterogeneity (I2): 0%

Pooled effect (random effects model): 1.47 (95%

CI 0.62 to 3.46), p=0.38

favoring conventional Heterogeneity (I2): 0%

Mesh replacement for local seroma

Pooled effect for sublay mesh position (studies C, D, F, H, I) (random effects model): 1.99 (95% CI 1.05

to 3.76), p=0.03 favoring conventional Heterogeneity (I2): 0%

Pooled effect for onlay mesh position (studies A, B, E) (random effects model): 2.12 (95% CI 0.20

to 22.70), p=0.53 favoring conventional

Heterogeneity (I2): 86%

Unclear whether groups were comparable at baseline (no data on other characteristics from individual studies included)

because they were not operated on. The 16 patients were evenly distributed across the two groups. Follow-up completeness was similar between the groups.

F: 5 patients in group L and 4 patients in group O were lost to follow-up evaluation after 1 month. Review authors do not believe this will introduce bias

G: Follow-up was completed

in all patients.

H: No losses to follow-up mentioned.

I: Apparently no losses until the last follow-up 1 month after surgery

J: Only 54 of the 58 randomized patients were included in the analyses. 4 patients received a mesh other than PTFE (3 from the open group and 1 from the laparoscopic group). This violates the intention-to-treat principle

Pooled effect (random effects model): 0.26 (95%

CI 0.15 to 0.46), p<

0.00001 favoring laparoscopic Heterogeneity (I2): 0%

Outcome measure-4b Defined as local infection (requiting mesh removal)

Effect measure: RR (95% CI):

A: Not estimable

B: 0.25 (0.03 to 2.07)

D: 0.14 (0.01 to 2.65)

F: Not estimable G: Not estimable H: Not estimable

I: 3.00 (0.12 to 76.62)

J: 0.16 (0.01 to 3.21)

Pooled effect (random effects model): 0.32 (95%

CI 0.08 to 1.22), p=0.094,

favoring laparoscopic Heterogeneity (I2): 0%

Outcome measure-5 Defined as seroma

Effect measure: RR (95% CI):

A: 5.63 (1.35 to 23.44)

B: 9.00 (0.51 to 158.17)

C: 2.14 (0.91 to 5.04)

D: 0.09 (0.01 to 1.57)

Pooled effect for IPOM position (study J) (random effects model): 0.50 (95% CI 0.19 to 1.33),

p=0.17 favoring laparoscopic Heterogeneity (I2): NA

Heterogeneity for seroma may explained by the mesh position.

E: 0.33 (0.14 to 0.79)

F: 4.00 (0.47 to 33.91)

H: 5.00 (0.27 to 94.34)

I: 2.00 (0.52 to 7.74)

J: 0.50 (0.19 to 1.33)

Pooled effect (random

effects model): 1.42 (95%

CI 0.60 to 3.40), p=0.43

favoring conventional

Heterogeneity (I2): 69%

Study reference

Study characteristics

Patient characteristics 2

Intervention (I)

Comparison / control (C) 3

Follow-up

Outcome measures and

effect size 4

Comments

Eker, 2013

Type of study: Non-blinded randomised controlled trial

Setting:

Clinical multicentre setting (2 university

hospitals and 8 teaching hospitals)

Country: The Netherlands

Source of funding: Not reported

Inclusion criteria:

-hernia diameter 3 -15 cm

-location at the ventral abdominal wall at least 5 cm from the costae and inguinal area indication for elective repair

-age ≥18 years

-written informed consent

Exclusion criteria:

-contraindication for pneumo-peritoneum

-absolute

contraindication

Laparoscopic incisional hernia repair was performed through 3 to 5 abdominal trocars (one 10mmand 2 to four 5 mm). The mesh was introduced into the abdominal cavity through the 10-

Mm trocar. The mesh was then placed over the defect with at least 5-cm overlap at all sides. Fixation of the mesh was achieved by 5- mm non absorbable tackers.

Open ventral incisional hernia repair:

After closing of the peritoneum or posterior rectus sheath, a mesh was positioned preperitoneally or in the sublay position, respectively, with at least 5-cm overlap at all sides. The mesh was fixated to the rectus muscle at each corner

and side with non- absorbable (polypropylene) sutures

Length of follow-up: Preoperatively, patients were asked to complete VAS scales for pain and nausea at 3 days, 1 week, and 4 weeks postoperatively.

After

discharge from the hospital, patients were invited for follow-up visits at outpatient clinics at 1 week, 6 weeks, 1 year, and 5 years.

Postoperative pain on day 1, mean on VAS scale:

L: 5.1

O: 4.3

Hernia recurrence rate: N (%):

L: 17 (18)

O: 14 (14) P=0.30 (log rank test)

Seroma: N(%):

L: 7 (7)

O: 4 (4)

Mean on VAS scale voor acute pain afgelezen uit grafiek (onnauwkeurig, dus niet meegenomen in literatuur analyse)

for general anesthesia

Loss-to-follow-up:

-history of an open

Twelve patients

Infections

abdomen treatment

withdrew consent or

(wound

-Patients participating

underwent no

infection) N(%)

in other trials

incisional hernia

L: 4 (4)

repair after

O: 5 (5)

N total at baseline:

randomization.

Randomized:

At a mean (SD)

Laporoscopic:n=99

follow-up of 35 (33.3)

Open: n=107

months after index

surgery, 146 of 194

Analyzed:

patients (75%)

Laporoscopic:n=94

completed follow-

Open: n=100

up

Important prognostic

Incomplete outcome

factors2:

data:

Age: mean (SD)

94 patients were

L: 59.1 (12.8)

analysed

O: 56.7 (12.8)

Sex: % M

L: 60%

O: 59%

Preoperative BMI,

mean (SD):

L: 28.3 (4.7)

O: 29.3 (4.6)

Groups were

comparable at baseline

Rogmark, 2013

Type of study: Non-blinded randomised controlled trial

Inclusion criteria:

Age ≥ 18 years age Incisional hernia within the compartment of the

Pneumoperitoneum was achieved by an open-access technique laterally and the intra-abdominal

The retromuscular rectus aponeurosis was sutured and the hernia sac

invaginated. A heavyweight

Length of follow-up: 8 weeks

Loss-to-follow-up:

Hernia Recurrence (after 8 weeks):

L: 0 (0%)

O: 0 (0%)

Mean on VAS scale voor acute pain afgelezen uit grafiek

(onnauwkeurig, dus niet meegenomen

Setting:

2 university hospitals and 5 general

public hospitals 11 surgeons

Country: Sweden

Source of funding: funding from Lund University, Region Skane Research & Development Funds, Ethicon, Johnson & Johnson Medical Ltd., The Einar and Inga Nilsson Foundation, The Anna Lisa and Sven- Eric Lundgren Foundation,

and The Crafoord Foundation.

rectus muscles and with a hernia defect not exceeding 10 cm in width at preoperative physical examination.

Hernias

medially located in otherwise sufficient oblique or transverse incisions were accepted.

Exclusion criteria: Emergency operation, previous hernia mesh repairs, parastomal hernias, other planned simultaneous operation, immunesuppressive therapy, liver cirrhosis, ascites, generalized malignancy, enterocutaneous fistula, skin infection, physical conditions precluding

laparoscopic surgery, the ASA grade > III, risk of pulmonary insufficiency after reduction of

hernia content,

previous open abdomen treatment,

former abdominal

insufflation pressure was set at a

maximum of 10 to 12 mm Hg. A minimum of 3 trocars were used.

The total length of the old scar was covered with a composite mesh of appropriate size, overlapping the hernia defect by at least 5 cm. It

polypropylene mesh was positioned behind the rectus muscles, reaching the lateral borders covering the total length of the dissected area. An exception from covering the total length of the old scar was in the case of a hernia located in the midline of an oblique or transverse incision. The mesh was fixed to the closed posterior aponeurosis with only a running non-absorbable suture in the midline. The anterior aponeurosis was closed in front of the mesh, and when this was not possible, sutured to the mesh.

Of 157 randomized

patients, 133

received intervention and were analysed During follow-up:

2 lost to follow-up in LR (peritoneal carcinosis and

missing protocol data) and 2 (declined further participation and undiagnosed abuse) in OR.

Incomplete outcome data:

Intention to treat analysis was reported

Postoperative Pain 0-5 days (VAS)

L: 5.2

O: 4.3

Surgical Site Infections

L: n=1 O: n=16 P<0.001

(Fischer exact test)

in literatuur analyse)

radiation therapy, body

mass index (BMI)

exceeding 40 kg/m2,

bleeding

disorders, females

planning future

pregnancy, and

psychological

or social conditions

prohibiting the patient

to adhere to the

protocol

N total at baseline:

157 randomized

patients, 133 received

intervention: 64 LR and

69 OR.

Important prognostic

factors2:

Age: mean (SD)

L: 58 (13.6)

O: 58 (11.1)

Sex: % M

L: 42%

O: 41%

BMI, mean (SD):

L: 29.3 (4.0)

O: 29.3 (4.7)

Groups were

comparable at baseline

Study

reference

Study

characteristics

Patient

characteristics

Intervention (I)

Comparison / control

(C)

Follow-up

Outcome measures and

effect size

Comments

Mathes, 2016

SR and meta-

analysis of RCT’s

Literature search up to (06/2014)

A: Luijendijk, 2000

B: Korenkov, 2002

C: Venclauskas, 2010

D: Weber, 2010

Study design: RCT

Setting and Country:

Inclusion criteria SR:

1. Patients Adult patients (C18) with primary or incisional ventral hernia 2. Intervention/co mparison of suture versus mesh repair

3. Outcomes Recurrence (primary), overall or long- term complications, quality of life or pain
4. Study type

RCT

Describe intervention:

A:

Mesh (sublay, polypropylene)

B:

Suture

C:

Mesh (onlay, Polypropylene + polyglecaprone

CG1)

D:

Mesh (sublay)

Describe control:

A: Suture

(polypropylene)

B:

Mesh (onlay

polypropylene)

Onlay autodermal skin graft

C:

Suture (nonabsorbable, keel technique,

IG)

D:

Suture

End-point of follow-up:

A: 3 years

B: 9 months

C: 12 months

D: 5 years

For how many participants were no complete outcome data available? (intervention/control) A:

Randomised: 84/97 Analysed: 84/97

B:

Randomised: 33/39 + 28 Analysed: 33/39+ 28

C:

Randomised: 54/57+50

Outcome measure-1 Number of recurrences

Effect measure: RR, RD, mean difference (95% CI): A: 17 versus 39; 0.005

B: 4 versus 3 versus 4; NS

C: 12 versus 6 versus 1; NS (IG versus CG1); P= 0.002

D: 15 (8 %) versus 50 (27

%); p= 0.001

Pooled effect (random effects model / fixed effects model): 0.39((0.28, 0.54)

favouring mesh. Heterogeneity (I2): 0% P=<0.00001

Facultative:

Brief description of

author’s conclusion

Personal remarks on study quality, conclusions, and other issues (potentially) relevant to the research question

Level of evidence: GRADE (per comparison and outcome measure) including reasons for down/upgrading

Sensitivity analyses (excluding small studies; excluding studies with

short follow-up;

Faculty of Health-School of Medicine, Institute for

Research in Operative Medicine, Witten/Herdeck e University, Cologne, Germany

Source of funding:

Non-commercial

/ there was no funding for this systematic review.

5. Language Article in English or German Exclusion criteria SR:

Not mentioned

4 studies included

Hernia type: A: Primary or first time recurrent

vertical midline incisional hernia (≥ 6 cm)

B: Simple incisional hernia (< 10 cm diameter)

C: Middle incisional hernia D: Ventral

hernias ≤ 25

cm2

Important patient characteristics at baseline: Number of patients; characteristics important to the

research

Analysed: 50/53+49

D:

Randomised: 247/247 Analysed: 180/184

excluding low quality studies; relevant subgroup-analyses); mention only analyses which are of potential importance to the research question

Heterogeneity: clinical and statistical heterogeneity; explained versus unexplained (subgroupanalysis)

question and/or

for statistical

adjustment

(confounding in

cohort studies);

for example,

age, sex, bmi,...

N

A: I:84/ C:97

B: I: 33/ C 39 +

28

C: I: 54/C:57+50

D: I: 247/C: 247

Age:

A: Median

(Range)

I:63 (25–82)

C: 57 (23–85)

B: Mean ± SD

I:60 ± 13/ 50 ±

17

C: 61 ± 11

C: Mean ± SD

I: 56.9 ± 11.5

/53 ± 11.6

C: 54.2 ± 12.4

D:??

Sex:

A: Ratio

Male 1.0:1

Female 1.5:1

B:

I: 32%/33%

C: 25%

C:

D:

Groups comparable at

baseline?

Study

First author,

year

Appropriate and clearly focused question?1

Yes/no/unclear

Comprehensive and systematic literature search?2

Yes/no/unclear

Description of included and excluded studies?3

Yes/no/unclear

Description of relevant characteristics of included studies?4

Yes/no/unclear

Appropriate adjustment for potential confounders in observational studies?5

Yes/no/unclear/notapplicable

Assessment of scientific quality of included studies?6

Yes/no/unclear

Enough similarities between studies to make combining them reasonable?7

Yes/no/unclear

Potential risk of publication bias taken into account?8

Yes/no/unclear

Potential conflicts of interest reported?9

Yes/no/unclear

Sauerland, 2011

Yes

Yes

Yes

Yes

Not applicable, all RCT’s

Yes

Yes

Yes

Yes

Mathes,

2015

Yes

Yes

No

No

Not applicable, all RCT’s

Yes

Yes

No

Yes

Study reference

(first author, publicatio

n year)

Describe method of randomisation1

Bias due to inadequate concealment of allocation?2

(unlikely/likely/uncle ar)

Bias due to inadequate blinding of participants to treatment allocation?3

(unlikely/likely/uncle ar)

Bias due to inadequate blinding of care providers to treatment allocation?3

(unlikely/likely/uncle ar)

Bias due to inadequate blinding of outcome assessors to treatment allocation?3

(unlikely/likely/uncle ar)

Bias due to selective outcome reporting on basis of the results?4

(unlikely/likely/uncle ar)

Bias due to loss to follow-up?5

(unlikely/likely/uncle ar)

Bias due to violation of

intention to treat analysis?6

(unlikely/likely/uncle ar)

Eker, 2013

Patients were

randomized by computer-generated lists stratified by center and primary or recurrent incisional hernia.

Unclear

Likely

Likely

Likely

Unlikely

Unclear

Unclear

Rogmark, 2013

For allocation of the participants, a computer-generated list of random numbers was used. The randomization sequence was

created using Microsoft Excel

2003 and was stratified by the center with a 1:1

allocation using

Unlikely

Likely

Likely

Likely

Unlikely

Unlikely