t h e s u r g e o n 1 2 ( 2 0 1 4 ) 8 7 e9 3
Available online at www.sciencedirect.com
ScienceDirect The Surgeon, Journal of the Royal Colleges of Surgeons of Edinburgh and Ireland www.thesurgeon.net
Review
Meta-analysis of self-gripping mesh (Progrip) versus sutured mesh in open inguinal hernia repair Sanjay Pandanaboyana a,*, Devender Mittapalli b, Ahsan Rao b, Raj Prasad a, Niaz Ahmad a a b
Department of HPB Surgery, St. James Hospital, Beckett Street, Leeds LS7 1BD, United Kingdom Department of Surgery, Ninewells Hospital, Dundee DD2 5BN, United Kingdom
article info
abstract
Article history:
Background: This metaanalysis was designed to systematically analyse all published ran-
Received 8 October 2013
domized controlled trials comparing self-gripping mesh (ProGrip) and sutured mesh to
Received in revised form
analyse early and long term outcomes for open inguinal hernia repair.
24 November 2013
Methods: A literature search was performed using the Cochrane Colorectal Cancer Group
Accepted 25 November 2013
Controlled Trials Register, the Cochrane Central Register of Controlled Trials in the
Available online 11 January 2014
Cochrane Library, MEDLINE, Embase and Science Citation Index Expanded. Randomized trials comparing self-gripping mesh with sutured mesh were included. Statistical analysis
Keywords:
was performed using Review Manager Version 5.2 software. The primary outcome mea-
Inguinal hernia
sures were hernia recurrence and chronic pain after operation. Secondary outcome mea-
Progrip
sures included surgical time, wound complications and perioperative complications.
Metaanalysis
Results: Five randomized trials were identified as suitable, including 1170 patients. There was no significant difference between the two types of mesh repairs in perioperative complications, wound haematoma, chronic groin pain and hernia recurrence. Wound infection was lower in self gripping mesh group compared to sutured mesh but this was not statistically significant (risk ratio (RR) 0.57, 95% confidence interval 0.30e1.06, P ¼ 0.08). The duration of operation was significantly shorter with self-gripping mesh compared to sutured mesh with a mean difference of 5.48 min [9.31, 1.64] Z ¼ 2.80 (P ¼ 0.005). Conclusion: Self-gripping mesh was associated with shorter operative time compared to sutured mesh. Both types of mesh repairs have comparable perioperative and long term outcomes. ª 2013 Royal College of Surgeons of Edinburgh (Scottish charity number SC005317) and Royal College of Surgeons in Ireland. Published by Elsevier Ltd. All rights reserved.
* Corresponding author. Department of HPB and Transplant Surgery, St. James Hospital, Leeds LS7 1BD, United Kingdom. E-mail address: [email protected] (S. Pandanaboyana). 1479-666X/$ e see front matter ª 2013 Royal College of Surgeons of Edinburgh (Scottish charity number SC005317) and Royal College of Surgeons in Ireland. Published by Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.surge.2013.11.024
88
t h e s u r g e o n 1 2 ( 2 0 1 4 ) 8 7 e9 3
Introduction
Types of participants
Lichtenstein mesh repair is generally considered the gold standard technique for inguinal hernia repair.1 Although hernia recurrence rates have significantly reduced over the years, the levels of chronic groin pain after elective hernia repair have not reduced to the same extent, ranging between 19 and 29%.2,3 Chronic groin pain can be debilitating with impact on convalescence and return to work.4 Several factors can affect the incidence of groin pain such as type of mesh used5 and fixation of mesh.6 A recent study comparing conventional sutured fixation of the mesh with mesh fixation with fibrin glue has shown a reduction in chronic pain at 12 months with fibrin glue fixation.6 A further metaanalysis comparing glue versus sutured mesh fixation for Lichtenstein inguinal hernia repair has shown glue mesh fixation compared with sutures is faster and less painful, with comparable hernia recurrence rates.7 This suggests that the pain after mesh repair may be related to suture fixation of the mesh. Subsequent to this, a new self-gripping mesh (Parietene Progrip; Sofradim, Trevoux, France) that provided a Velcro like adherence to underlying tissues was developed with significant improvement in recurrence rates and chronic groin pain.8 Several randomised controlled trials are published in the recent past comparing self-gripping mesh with sutured repair to assess perioperative and long term outcomes. The objective of this study is to perform a metaanalysis of published randomized controlled trials comparing self-gripping mesh and sutured mesh in regards operative time, wound related complications and perioperative complications, chronic groin pain and hernia recurrence.
Adult patients (age 18) of both genders who underwent inguinal hernia repair (direct and indirect) were included. Patients with recurrent and bilateral inguinal hernias were excluded. Patients with femoral hernias were also excluded.
Methods Randomized controlled trials, irrespective of language, country of origin, hospital of origin, blinding, sample size or publication status, that compared the use of self-gripping mesh and standard sutured Lichtenstein mesh in open inguinal hernia repair were included in this review. The Cochrane Colorectal Cancer Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials in the Cochrane Library, MEDLINE, Embase and Science Citation Index Expanded were searched for articles published up to September 2013 using the medical subject headings (MeSH) terms ‘inguinal hernia’ and ‘groin hernia’. Equivalent freetext search terms, such as ‘mesh repair of inguinal hernia’, ‘inguinal hernioplasty’ and ‘tension free inguinal hernia repair’ were used in combination with ‘Self gripping mesh’, Self fixating mesh, Progrip mesh, Adhesive mesh and ‘Lichtenstein mesh’ and ‘Lichtenstein repair’. A filter for identifying randomized controlled trials recommended by the Cochrane Collaboration9 was used to filter out nonrandomized studies in MEDLINE and Embase. The references from the included trials were searched to identify additional trials.
Types of outcome measures The primary outcome measures were hernia recurrence and chronic pain after operation. Secondary outcome measures included surgical time, wound complications and perioperative complications. Peri-operative complications were defined as those arising 30 days from surgery. Chronic pain was defined as persistent groin pain or any groin discomfort affecting daily activities that did not disappear by 3 months after surgery. Wound Complications included haematoma, seroma and infection. Perioperative complications included urinary retention, seroma, infection, sensory loss, reoperation, delayed wound healing, testicular swelling, hyperaesthesia, mesh-related problems, hydrocoele or scrotal swelling, testicular pain, atrophy, numbness, groin pain and recurrence whether it was reported early or late.
Data extraction and quality assessment The trials for inclusion and exclusion were identified and data extracted by two authors independently. The accuracy of the extracted data was further confirmed by a third author. It was agreed that the lack of an adequate randomization technique and an intention-to-treat analysis would result in the trials being classified as having a high risk of bias. The included studies were evaluated for quality using the Cochrane collaboration guidelines.9 The methodological quality of the included trials was assessed initially using the published guidelines of Jadad and colleagues.10
Statistical analysis Statistical analysis was performed using Review Manager Version 5.2 software (Cochrane Collaboration). The risk ratio (RR) with 95 per cent confidence interval (CI) was calculated for binary data, and the mean difference with 95 per cent CI for continuous variables. Where studies reported median and range instead of mean and variance, their mean and variance was calculated based on the methods described by Hozo and colleagues.11 Random and fixed-effects models were used to calculate the combined outcomes of both binary and continuous data.12,13 In cases of heterogeneity, only the results of the random-effects model were reported. Heterogeneity was explored using the X2 test, with significance set at P < 0$05. Low heterogeneity was defined as an I2 value of 33 per cent or less.14 Sensitivity analyses were also performed to assess any impact of study quality on the effect estimates. If the standard deviation was not available, it was calculated according to the guidelines of the Cochrane Collaboration.9 This process
89
t h e s u r g e o n 1 2 ( 2 0 1 4 ) 8 7 e9 3
involved assumptions that both groups had the same variance, which may not have been true, and variance was estimated either from the range or from the P value. Forest plots were used for graphical display of the results. Subgroup analysis of complications was performed to determine whether the mesh technique influenced the overall incidence of wound haematoma and infection.
Results The literature search strategy and trial selection are summarized in Fig. 1. Five published randomized controlled trials encompassing 1170 patients were analysed to achieve a summated outcome.15e19 For studies reporting outcomes for the same groups of patients at different follow-up times, data from the last follow-up were used. The longest follow up recorded was 12 months.16e18 There were 579 patients in the Self gripping mesh group and 591 the sutured mesh group. The characteristics of the included trials are shown in Table 1. Pooled data were analysed by combining the results of the five randomized trials. According to the published guidelines10 all trials scored highly enough to suggest good quality of the included trials. The quality of trials is summarised in Table 2.
Records identified through database searching (n = 98131)
Combined analysis of five trials Duration of operation Data from 5 trials was included in this analysis. There was significant heterogeneity amongst the trials (Tau2 ¼ 15.67; Chi2 ¼ 70.49, df ¼ 4 (P < 0.00001); I2 ¼ 94%). In the random-effects model, the duration of operation was significantly shorter with self-gripping mesh compared to sutured mesh with a mean difference of 5.48 min [9.31, 1.64] Z ¼ 2.80 (P ¼ 0.005) (Fig. 2).
Wound complications Wound haematoma Data from four trials was included in this analysis.15,16,18,19 There was no heterogeneity amongst the trials (X2 ¼ 1.23, df ¼ 3 (P ¼ 0.75); I2 ¼ 0%). %). In the fixed-effects model, the wound haematoma rate was not significantly between Self gripping mesh and sutured mesh RR 1.93 [0.79, 4.71] (Z ¼ 1.45 (P ¼ 0.15).
Wound seroma Data from two trials was included in this analysis.15,16 There was no heterogeneity amongst the trials (X2 ¼ 0.00, df ¼ 1
Additional records identified through other sources (n = 86)
Records after duplicates, animal studies, book articles and conference papers removed (n = 14173 )
Records screened (abstracts relevant to the topic) (n = 835 )
Full-text articles assessed for eligibility (n = 12 )
Studies included in qualitative synthesis (n = 5)
Abstracts excluded (observational studies, non-randomised trials, case series) (n = 823)
Full -text articles excluded, different groups compared (n = 3) or non randomised studies (n = 4)
Studies included in quantitative synthesis (meta -analysis) (n = 5)
Fig. 1 e PRISMA flow diagram for the literature search.
90
0.23
6
12
12
12
60
66.8 (mean age)
49b
Standard Polypropylene Standard Polypropylene
64.2b
Data from 5 trials was included in this analysis.15e19 There was no heterogeneity amongst the trials (X2 0.97, df ¼ 4 (P ¼ 0.91); I2 ¼ 0%). In the fixed-effects model, the perioperative complications rate were similar with the Self gripping mesh and sutured mesh RR 1.00 [0.81, 1.22] (Z ¼ 0.04) (P ¼ 0.97) (Fig. 3).
Chronic groin pain
Parietene Progrip PP1208 Parietene Progrip PP1208 45
Hernia recurrence Data from three trials was included in this analysis.16e18 There was no heterogeneity among the trials X2 ¼ 0.36, df ¼ 1 (P ¼ 0.55); I2 ¼ 0%. In a fixed-effects model, the risk of hernia recurrence following the use of Self-Gripping Mesh and Sutured mesh was not statistically different: RR 0.74 [0.15, 3.70] (Z ¼ 0.37) (P ¼ 0.71) (Fig. 5).
45 UK e United Kingdom; No. of Pts e Number of patients. a All values are median (range) except. b Mean.
Single
Sept 2007e Apr 2008 Mar 2009e Mar 2010 Kapischke et al.19 2010 Esteban et al.15 2010
Single
Data from 3 trials was included in this analysis.16e18 There was no heterogeneity amongst the trials (X2 ¼ 0.39, df ¼ 2 (P ¼ 0.82); I2 ¼ 0%). In the fixed-effects model, chronic groin pain was similar with the Self gripping mesh and sutured mesh RR 1.08 [0.84, 1.40] (Z ¼ 0.62) (P ¼ 0.53) (Fig. 4).
Discussion Spain
24
149 153
Belgium, Netherlands, Sweden, UK, Germany Germany
26
60 (31e74) 60 (31e74)
55 (20e79) 53 (19e80) 198 196 Finland
Self gripping Suture
59.9 (45.8e67.5) 56.8 (40.2e65.1)
Parietene Parietene light Progrip PP1208 Parietene Parietene light Progrip PP1208 Parietene Parietene light Progrip PP1208 166 172 Denmark
Data from 5 trials was included in this analysis.15e19 There was no heterogeneity amongst the trials (X2 ¼ 3.19, df ¼ 3 (P ¼ 0.36); I2 ¼ 6%). In the fixed-effects model, no statistically significant difference was noted in the wound infection rates with the Self gripping mesh compared to sutured mesh RR 0.57 [0.30, 1.06] (Z ¼ 1.77) (P ¼ 0.08).
Perioperative complications
Nov 2008e Apr 2010 Feb 2008e Jan 2010 Oct 2008e Jun 2012
No. of Pts: Suture No. of Pts: Self Self gripping Sutured mesh group gripping group mesh Country Inclusion period Centre
Table 1 e Characteristics of included trials.
Study
(P ¼ 0.99); I2 ¼ 0%). In the fixed-effects model, the wound seroma rate was not significantly different between Self gripping mesh and sutured mesh (RR 1.01 [0.14, 7.09] (Z ¼ 0.01) (P ¼ 0.99)).
Wound infection
Jorgensen et al.17 Multicentre 2012 Single centre Pierides et al.18 2012 Kingsnorth et al.16 Multicentre 2012
Agea
Median follow up (months)
t h e s u r g e o n 1 2 ( 2 0 1 4 ) 8 7 e9 3
This meta-analysis comparing self-gripping mesh and sutured mesh repairs has shown a shorter operating time with self-gripping mesh repair compared to standard polypropylene mesh repair. The overall perioperative complications, chronic groin pain and hernia recurrence are comparable between the 2 mesh repair techniques. The hernia recurrence rates have been significantly reduced over the years, however the incidence of chronic groin pain remains high. Although the precise cause for chronic groin pain is difficult to ascertain, a combinations of factors such as type of mesh used and technique of mesh fixation. Recent studies including a metaanalysis comparing fixation with glue and sutures have shown a significant reduction in the incidence of early chronic groin pain with glue fixation suggesting suture fixation may predispose to increased groin pain.7 On this back ground, Chastan devised a new mesh that provided Velcro like adherence to underlying tissues, and preliminary studies showed good results at 2 years with no chronic pain or recurrence.8 Five randomised
91
t h e s u r g e o n 1 2 ( 2 0 1 4 ) 8 7 e9 3
Table 2 e Quality assessment of included trials. Study Jorgensen et al.17 Pierides et al.18 Kingsnorth et al.16 Kapischke et al.19 Esteban et al.15
End point Chronic pain, numbness, groin discomfort Chronic pain Chronic pain Chronic pain, operative time Acute pain
Randomisation technique
Concealment
Blinding
Power calculation
Jadad score
Computerised
Sealed Envelope
Single
Not mentioned
4
Sealed envelope Computerised Sealed envelope
Sealed envelope Sealed envelope Sealed envelope
Double Single Single
Not mentioned Not mentioned Yes
4 5 4
Sealed envelope
Sealed envelope
Single
Not mentioned
2
Fig. 2 e Forest plot comparing duration of operation from 5 trials comparing self gripping mesh and sutured mesh. A random-effects model was used for meta-analysis. Mean differences are shown with 95 per cent confidence intervals. trials comparing self-gripping mesh and sutured mesh have been published comparing short15 and long term outcomes.16e19 All the trials have shown a significantly shorter operative time with the self-gripping mesh compared to sutured mesh15e19 which is further confirmed in the pooled analysis of the five studies in this metaanalysis. A significant heterogeneity was noted amongst the included trials. The reduction in operating time with self-gripping mesh is attributed to lack of need for suturing during hernia repair reducing the operative time. This may translate to overall cost effectiveness by increasing the number of hernia repairs performed on a specific operating list, however, to date no cost
effectiveness study has been performed comparing the 2 mesh repair techniques. The wound infection rates were higher in the sutured mesh group compared to self-gripping mesh although the results were not statistically significant. Two trials in the metaanalysis did not show any difference in the wound infection rates, while one trial showed higher infection rates with sutured mesh. The cause for the increased infection rates in the sutured mesh group is difficult to ascertain, but may be related to longer operative time and dissection needed compared to selfgripping mesh. A recent study20 on abdominal wall hernia repair has shown that operative time is a significant factor
Fig. 3 e Forest plot comparing perioperative complications for self-gripping mesh and sutured mesh from 5 trials. A ManteleHaenszel fixed-effects model was used for meta-analysis. Risk ratios are shown with 95 per cent confidence intervals.
Fig. 4 e Forest plot comparing chronic groin pain from 3 trials following the use of self-gripping mesh and sutured mesh. A ManteleHaenszel fixed-effects model was used for meta-analysis. Risk ratios are shown with 95 per cent confidence intervals.
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t h e s u r g e o n 1 2 ( 2 0 1 4 ) 8 7 e9 3
Fig. 5 e Forest plot comparing hernia recurrence from 3 trials following the use of self-gripping mesh and sutured mesh. A ManteleHaenszel fixed-effects model was used for meta-analysis. Risk ratios are shown with 95 per cent confidence intervals.
predisposing to mesh infection, however we should be cautiously interpreted as the cause for wound infections are multifactorial and abdominal wall hernia repair is a significantly longer operation compared to inguinal hernia repair. In the present metaanalysis, three trials compared chronic groin pain16e18 and pooled analysis did not show any difference between the two groups. Four studies in this metaanalysis identified and preserved the ilioinguinal, iliohypogastric and genitofemoral nerves whenever possible.16e19 Chastan in his study has shown a significant reduction in neurological symptoms with the self-gripping mesh with only one patient out of 52 patients reporting mild discomfort in the groin.8 None of the trials in this metaanalysis obtained comparable results although 2 trials showed reduction in early postoperative pain,16,19 but no impact on long term (>3months) groin pain. This raises questions on the potential benefit of using self-gripping mesh to minimise long term pain. Larger studies with longer follow-up should clarify these issues. The summated hernia recurrence rates in this metaanalysis were 0.4% for the self-gripping mesh and 0.5% for the sutured mesh repair, and were not significantly different. These recurrent rates are comparable with laparoscopic repair inguinal hernia repair and better than non-mesh repairs.21 In addition, one trial compared patient satisfaction between the 2 mesh techniques and showed no significant difference. There are several limitations in this metaanalysis. There was no comparable data available to assess early postoperative pain, return to work and quality of life between the two mesh repair techniques. Trials recruiting a small number of patients in this metaanalysis may not have had sufficient power to recognize small differences in outcomes between self-gripping mesh and sutured mesh. While this meta-analysis does not provide data on cost-benefit analysis or longer than 1 year follow-up, early results suggests significant advantage with self-gripping mesh in reducing operating time. Further larger trials with longer follow up are needed to evaluate potential long term benefits such as chronic groin pain.
references
1. Amid PK, Lichtenstein IL. Long-term result and current status of the Lichtenstein open tension-free hernioplasty. Hernia 1998;2:89e94. 2. Koch A, Bringman S, Myrelid P, Smeds S, Kald A. Randomized clinical trial of groin hernia repair with titanium-coated
3.
4. 5.
6.
7.
8.
9.
10.
11.
12. 13.
14. 15.
16.
17.
lightweight mesh compared with standard polypropylene mesh. Br J Surg 2008;95:1226e31. Bay-Nielsen M, Nilsson E, Nordin P, Kehlet H, Base SHDBtDHD. Chronic pain after open mesh and sutured repair of indirect inguinal hernia in young males. Br J Surg 2004;91:1372e6. Fountain F. The chronic pain policy coalition. Ann R Coll Surg Engl 2006;88(Suppl):279. Bringman S, Wollert S, Osterberg J, Smedberg S, Granlund H, Heikkinen TJ. Three-year results of a randomized clinical trial of lightweight or standard polypropylene mesh in Lichtenstein repair of primary inguinal hernia. Br J Surg 2006;93:1056e9. Canonico S, Benevento R, Perna G, Guerniero R, Sciaudone G, Pellino G, et al. Sutureless fixation with fibrin glue of lightweight mesh in open inguinal hernia repair: effect on postoperative pain: a double-blind, randomized trial versus standard heavyweight mesh. Surgery 2013 Jan;153(1):126e30. de Goede B, Klitsie PJ, van Kempen BJ, Timmermans L, Jeekel J, Kazemier G, et al. Meta-analysis of glue versus sutured mesh fixation for Lichtenstein inguinal hernia repair. Br J Surg 2013 May;100(6):735e42. Chastan P. Tension-free open hernia repair using an innovative self-gripping semi-resorbable mesh. Hernia 2009;13:137e42. Higgins J, Green Se. Handbook for systematic reviews of interventions version 5.1.0 [updated March 2011], http://www. handbook.cochrane.org; 2011 [accessed 08.09.2013]. Jadad AR, Moore RA, Carroll D, Jenkinson C, Reynolds DJ, Gavaghan DJ, et al. Assessing the quality of reports of randomized clinical trials: is blinding necessary? Control Clin Trials 1996 Feb;17(1):1e12. Hozo SP, Djulbegovic B, Hozo I. Estimating the mean and variance from the median, range, and the size of a sample. BMC Med Res Methodol 2005;5:13. DerSimonian R, Laird N. Meta-analysis in clinical trials. Control Clin Trials 1986;7:177e88. Demets D. Methods for combining randomized clinical trials: strengths and limitations. Stat Med 1987 AprMay;6:341e50. Higgins JP, Thompson SG. Quantifying heterogeneity in a meta-analysis. Stat Med 2002;21:1539e58. Bruna Esteban M, Cantos Pallare´s M, Artigues Sa´nchez De Rojas E. Use of adhesive mesh in hernioplasty compared to the conventional technique. Results of a randomised prospective study. Cir Esp 2010 Oct;88(4):253e8. Kingsnorth A, Gingell-Littlejohn M, Nienhuijs S, Schu¨le S, Appel P, Ziprin P, et al. Randomized controlled multicenter international clinical trial of self-gripping Parietex ProGrip polyester mesh versus lightweight polypropylene mesh in open inguinal hernia repair: interim results at 3 months. Hernia 2012 Jun;16(3):287e94. Jorgensen LN, Sommer T, Assaadzadeh S, Strand L, Dorfelt A, Hensler M, et al. Randomized clinical trial of self-gripping
t h e s u r g e o n 1 2 ( 2 0 1 4 ) 8 7 e9 3
mesh versus sutured mesh for Lichtenstein hernia repair. Br J Surg 2013 Mar;100(4):474e81. 18. Pierides G, Scheinin T, Remes V, Hermunen K, Vironen J. Randomized comparison of self-fixating and sutured mesh in open inguinal hernia repair. Br J Surg 2012;99:630e6. 19. Kapischke M, Schulze H, Caliebe A. Self-fixating mesh for the Lichtenstein procedureea prestudy. Langenbecks Arch Surg 2010;395:317e22.
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20. Stremitzer S, Bachleitner-Hofmann T, Gradl B, Gruenbeck M, Bachleitner-Hofmann B, Mittlboeck M, et al. Mesh graft infection following abdominal hernia repair: risk factor evaluation and strategies of mesh graft preservation. A retrospective analysis of 476 operations. World J Surg 2010 Jul;34(7):1702e9. 21. Corbitt JJ. Transabdominal preperitoneal herniorrhaphy. Surg Laparosc Endosc 1993 Aug;3:328e32.
Available online at www.sciencedirect.com
ScienceDirect The Surgeon, Journal of the Royal Colleges of Surgeons of Edinburgh and Ireland www.thesurgeon.net
Review
Meta-analysis of self-gripping mesh (Progrip) versus sutured mesh in open inguinal hernia repair Sanjay Pandanaboyana a,*, Devender Mittapalli b, Ahsan Rao b, Raj Prasad a, Niaz Ahmad a a b
Department of HPB Surgery, St. James Hospital, Beckett Street, Leeds LS7 1BD, United Kingdom Department of Surgery, Ninewells Hospital, Dundee DD2 5BN, United Kingdom
article info
abstract
Article history:
Background: This metaanalysis was designed to systematically analyse all published ran-
Received 8 October 2013
domized controlled trials comparing self-gripping mesh (ProGrip) and sutured mesh to
Received in revised form
analyse early and long term outcomes for open inguinal hernia repair.
24 November 2013
Methods: A literature search was performed using the Cochrane Colorectal Cancer Group
Accepted 25 November 2013
Controlled Trials Register, the Cochrane Central Register of Controlled Trials in the
Available online 11 January 2014
Cochrane Library, MEDLINE, Embase and Science Citation Index Expanded. Randomized trials comparing self-gripping mesh with sutured mesh were included. Statistical analysis
Keywords:
was performed using Review Manager Version 5.2 software. The primary outcome mea-
Inguinal hernia
sures were hernia recurrence and chronic pain after operation. Secondary outcome mea-
Progrip
sures included surgical time, wound complications and perioperative complications.
Metaanalysis
Results: Five randomized trials were identified as suitable, including 1170 patients. There was no significant difference between the two types of mesh repairs in perioperative complications, wound haematoma, chronic groin pain and hernia recurrence. Wound infection was lower in self gripping mesh group compared to sutured mesh but this was not statistically significant (risk ratio (RR) 0.57, 95% confidence interval 0.30e1.06, P ¼ 0.08). The duration of operation was significantly shorter with self-gripping mesh compared to sutured mesh with a mean difference of 5.48 min [9.31, 1.64] Z ¼ 2.80 (P ¼ 0.005). Conclusion: Self-gripping mesh was associated with shorter operative time compared to sutured mesh. Both types of mesh repairs have comparable perioperative and long term outcomes. ª 2013 Royal College of Surgeons of Edinburgh (Scottish charity number SC005317) and Royal College of Surgeons in Ireland. Published by Elsevier Ltd. All rights reserved.
* Corresponding author. Department of HPB and Transplant Surgery, St. James Hospital, Leeds LS7 1BD, United Kingdom. E-mail address: [email protected] (S. Pandanaboyana). 1479-666X/$ e see front matter ª 2013 Royal College of Surgeons of Edinburgh (Scottish charity number SC005317) and Royal College of Surgeons in Ireland. Published by Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.surge.2013.11.024
88
t h e s u r g e o n 1 2 ( 2 0 1 4 ) 8 7 e9 3
Introduction
Types of participants
Lichtenstein mesh repair is generally considered the gold standard technique for inguinal hernia repair.1 Although hernia recurrence rates have significantly reduced over the years, the levels of chronic groin pain after elective hernia repair have not reduced to the same extent, ranging between 19 and 29%.2,3 Chronic groin pain can be debilitating with impact on convalescence and return to work.4 Several factors can affect the incidence of groin pain such as type of mesh used5 and fixation of mesh.6 A recent study comparing conventional sutured fixation of the mesh with mesh fixation with fibrin glue has shown a reduction in chronic pain at 12 months with fibrin glue fixation.6 A further metaanalysis comparing glue versus sutured mesh fixation for Lichtenstein inguinal hernia repair has shown glue mesh fixation compared with sutures is faster and less painful, with comparable hernia recurrence rates.7 This suggests that the pain after mesh repair may be related to suture fixation of the mesh. Subsequent to this, a new self-gripping mesh (Parietene Progrip; Sofradim, Trevoux, France) that provided a Velcro like adherence to underlying tissues was developed with significant improvement in recurrence rates and chronic groin pain.8 Several randomised controlled trials are published in the recent past comparing self-gripping mesh with sutured repair to assess perioperative and long term outcomes. The objective of this study is to perform a metaanalysis of published randomized controlled trials comparing self-gripping mesh and sutured mesh in regards operative time, wound related complications and perioperative complications, chronic groin pain and hernia recurrence.
Adult patients (age 18) of both genders who underwent inguinal hernia repair (direct and indirect) were included. Patients with recurrent and bilateral inguinal hernias were excluded. Patients with femoral hernias were also excluded.
Methods Randomized controlled trials, irrespective of language, country of origin, hospital of origin, blinding, sample size or publication status, that compared the use of self-gripping mesh and standard sutured Lichtenstein mesh in open inguinal hernia repair were included in this review. The Cochrane Colorectal Cancer Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials in the Cochrane Library, MEDLINE, Embase and Science Citation Index Expanded were searched for articles published up to September 2013 using the medical subject headings (MeSH) terms ‘inguinal hernia’ and ‘groin hernia’. Equivalent freetext search terms, such as ‘mesh repair of inguinal hernia’, ‘inguinal hernioplasty’ and ‘tension free inguinal hernia repair’ were used in combination with ‘Self gripping mesh’, Self fixating mesh, Progrip mesh, Adhesive mesh and ‘Lichtenstein mesh’ and ‘Lichtenstein repair’. A filter for identifying randomized controlled trials recommended by the Cochrane Collaboration9 was used to filter out nonrandomized studies in MEDLINE and Embase. The references from the included trials were searched to identify additional trials.
Types of outcome measures The primary outcome measures were hernia recurrence and chronic pain after operation. Secondary outcome measures included surgical time, wound complications and perioperative complications. Peri-operative complications were defined as those arising 30 days from surgery. Chronic pain was defined as persistent groin pain or any groin discomfort affecting daily activities that did not disappear by 3 months after surgery. Wound Complications included haematoma, seroma and infection. Perioperative complications included urinary retention, seroma, infection, sensory loss, reoperation, delayed wound healing, testicular swelling, hyperaesthesia, mesh-related problems, hydrocoele or scrotal swelling, testicular pain, atrophy, numbness, groin pain and recurrence whether it was reported early or late.
Data extraction and quality assessment The trials for inclusion and exclusion were identified and data extracted by two authors independently. The accuracy of the extracted data was further confirmed by a third author. It was agreed that the lack of an adequate randomization technique and an intention-to-treat analysis would result in the trials being classified as having a high risk of bias. The included studies were evaluated for quality using the Cochrane collaboration guidelines.9 The methodological quality of the included trials was assessed initially using the published guidelines of Jadad and colleagues.10
Statistical analysis Statistical analysis was performed using Review Manager Version 5.2 software (Cochrane Collaboration). The risk ratio (RR) with 95 per cent confidence interval (CI) was calculated for binary data, and the mean difference with 95 per cent CI for continuous variables. Where studies reported median and range instead of mean and variance, their mean and variance was calculated based on the methods described by Hozo and colleagues.11 Random and fixed-effects models were used to calculate the combined outcomes of both binary and continuous data.12,13 In cases of heterogeneity, only the results of the random-effects model were reported. Heterogeneity was explored using the X2 test, with significance set at P < 0$05. Low heterogeneity was defined as an I2 value of 33 per cent or less.14 Sensitivity analyses were also performed to assess any impact of study quality on the effect estimates. If the standard deviation was not available, it was calculated according to the guidelines of the Cochrane Collaboration.9 This process
89
t h e s u r g e o n 1 2 ( 2 0 1 4 ) 8 7 e9 3
involved assumptions that both groups had the same variance, which may not have been true, and variance was estimated either from the range or from the P value. Forest plots were used for graphical display of the results. Subgroup analysis of complications was performed to determine whether the mesh technique influenced the overall incidence of wound haematoma and infection.
Results The literature search strategy and trial selection are summarized in Fig. 1. Five published randomized controlled trials encompassing 1170 patients were analysed to achieve a summated outcome.15e19 For studies reporting outcomes for the same groups of patients at different follow-up times, data from the last follow-up were used. The longest follow up recorded was 12 months.16e18 There were 579 patients in the Self gripping mesh group and 591 the sutured mesh group. The characteristics of the included trials are shown in Table 1. Pooled data were analysed by combining the results of the five randomized trials. According to the published guidelines10 all trials scored highly enough to suggest good quality of the included trials. The quality of trials is summarised in Table 2.
Records identified through database searching (n = 98131)
Combined analysis of five trials Duration of operation Data from 5 trials was included in this analysis. There was significant heterogeneity amongst the trials (Tau2 ¼ 15.67; Chi2 ¼ 70.49, df ¼ 4 (P < 0.00001); I2 ¼ 94%). In the random-effects model, the duration of operation was significantly shorter with self-gripping mesh compared to sutured mesh with a mean difference of 5.48 min [9.31, 1.64] Z ¼ 2.80 (P ¼ 0.005) (Fig. 2).
Wound complications Wound haematoma Data from four trials was included in this analysis.15,16,18,19 There was no heterogeneity amongst the trials (X2 ¼ 1.23, df ¼ 3 (P ¼ 0.75); I2 ¼ 0%). %). In the fixed-effects model, the wound haematoma rate was not significantly between Self gripping mesh and sutured mesh RR 1.93 [0.79, 4.71] (Z ¼ 1.45 (P ¼ 0.15).
Wound seroma Data from two trials was included in this analysis.15,16 There was no heterogeneity amongst the trials (X2 ¼ 0.00, df ¼ 1
Additional records identified through other sources (n = 86)
Records after duplicates, animal studies, book articles and conference papers removed (n = 14173 )
Records screened (abstracts relevant to the topic) (n = 835 )
Full-text articles assessed for eligibility (n = 12 )
Studies included in qualitative synthesis (n = 5)
Abstracts excluded (observational studies, non-randomised trials, case series) (n = 823)
Full -text articles excluded, different groups compared (n = 3) or non randomised studies (n = 4)
Studies included in quantitative synthesis (meta -analysis) (n = 5)
Fig. 1 e PRISMA flow diagram for the literature search.
90
0.23
6
12
12
12
60
66.8 (mean age)
49b
Standard Polypropylene Standard Polypropylene
64.2b
Data from 5 trials was included in this analysis.15e19 There was no heterogeneity amongst the trials (X2 0.97, df ¼ 4 (P ¼ 0.91); I2 ¼ 0%). In the fixed-effects model, the perioperative complications rate were similar with the Self gripping mesh and sutured mesh RR 1.00 [0.81, 1.22] (Z ¼ 0.04) (P ¼ 0.97) (Fig. 3).
Chronic groin pain
Parietene Progrip PP1208 Parietene Progrip PP1208 45
Hernia recurrence Data from three trials was included in this analysis.16e18 There was no heterogeneity among the trials X2 ¼ 0.36, df ¼ 1 (P ¼ 0.55); I2 ¼ 0%. In a fixed-effects model, the risk of hernia recurrence following the use of Self-Gripping Mesh and Sutured mesh was not statistically different: RR 0.74 [0.15, 3.70] (Z ¼ 0.37) (P ¼ 0.71) (Fig. 5).
45 UK e United Kingdom; No. of Pts e Number of patients. a All values are median (range) except. b Mean.
Single
Sept 2007e Apr 2008 Mar 2009e Mar 2010 Kapischke et al.19 2010 Esteban et al.15 2010
Single
Data from 3 trials was included in this analysis.16e18 There was no heterogeneity amongst the trials (X2 ¼ 0.39, df ¼ 2 (P ¼ 0.82); I2 ¼ 0%). In the fixed-effects model, chronic groin pain was similar with the Self gripping mesh and sutured mesh RR 1.08 [0.84, 1.40] (Z ¼ 0.62) (P ¼ 0.53) (Fig. 4).
Discussion Spain
24
149 153
Belgium, Netherlands, Sweden, UK, Germany Germany
26
60 (31e74) 60 (31e74)
55 (20e79) 53 (19e80) 198 196 Finland
Self gripping Suture
59.9 (45.8e67.5) 56.8 (40.2e65.1)
Parietene Parietene light Progrip PP1208 Parietene Parietene light Progrip PP1208 Parietene Parietene light Progrip PP1208 166 172 Denmark
Data from 5 trials was included in this analysis.15e19 There was no heterogeneity amongst the trials (X2 ¼ 3.19, df ¼ 3 (P ¼ 0.36); I2 ¼ 6%). In the fixed-effects model, no statistically significant difference was noted in the wound infection rates with the Self gripping mesh compared to sutured mesh RR 0.57 [0.30, 1.06] (Z ¼ 1.77) (P ¼ 0.08).
Perioperative complications
Nov 2008e Apr 2010 Feb 2008e Jan 2010 Oct 2008e Jun 2012
No. of Pts: Suture No. of Pts: Self Self gripping Sutured mesh group gripping group mesh Country Inclusion period Centre
Table 1 e Characteristics of included trials.
Study
(P ¼ 0.99); I2 ¼ 0%). In the fixed-effects model, the wound seroma rate was not significantly different between Self gripping mesh and sutured mesh (RR 1.01 [0.14, 7.09] (Z ¼ 0.01) (P ¼ 0.99)).
Wound infection
Jorgensen et al.17 Multicentre 2012 Single centre Pierides et al.18 2012 Kingsnorth et al.16 Multicentre 2012
Agea
Median follow up (months)
t h e s u r g e o n 1 2 ( 2 0 1 4 ) 8 7 e9 3
This meta-analysis comparing self-gripping mesh and sutured mesh repairs has shown a shorter operating time with self-gripping mesh repair compared to standard polypropylene mesh repair. The overall perioperative complications, chronic groin pain and hernia recurrence are comparable between the 2 mesh repair techniques. The hernia recurrence rates have been significantly reduced over the years, however the incidence of chronic groin pain remains high. Although the precise cause for chronic groin pain is difficult to ascertain, a combinations of factors such as type of mesh used and technique of mesh fixation. Recent studies including a metaanalysis comparing fixation with glue and sutures have shown a significant reduction in the incidence of early chronic groin pain with glue fixation suggesting suture fixation may predispose to increased groin pain.7 On this back ground, Chastan devised a new mesh that provided Velcro like adherence to underlying tissues, and preliminary studies showed good results at 2 years with no chronic pain or recurrence.8 Five randomised
91
t h e s u r g e o n 1 2 ( 2 0 1 4 ) 8 7 e9 3
Table 2 e Quality assessment of included trials. Study Jorgensen et al.17 Pierides et al.18 Kingsnorth et al.16 Kapischke et al.19 Esteban et al.15
End point Chronic pain, numbness, groin discomfort Chronic pain Chronic pain Chronic pain, operative time Acute pain
Randomisation technique
Concealment
Blinding
Power calculation
Jadad score
Computerised
Sealed Envelope
Single
Not mentioned
4
Sealed envelope Computerised Sealed envelope
Sealed envelope Sealed envelope Sealed envelope
Double Single Single
Not mentioned Not mentioned Yes
4 5 4
Sealed envelope
Sealed envelope
Single
Not mentioned
2
Fig. 2 e Forest plot comparing duration of operation from 5 trials comparing self gripping mesh and sutured mesh. A random-effects model was used for meta-analysis. Mean differences are shown with 95 per cent confidence intervals. trials comparing self-gripping mesh and sutured mesh have been published comparing short15 and long term outcomes.16e19 All the trials have shown a significantly shorter operative time with the self-gripping mesh compared to sutured mesh15e19 which is further confirmed in the pooled analysis of the five studies in this metaanalysis. A significant heterogeneity was noted amongst the included trials. The reduction in operating time with self-gripping mesh is attributed to lack of need for suturing during hernia repair reducing the operative time. This may translate to overall cost effectiveness by increasing the number of hernia repairs performed on a specific operating list, however, to date no cost
effectiveness study has been performed comparing the 2 mesh repair techniques. The wound infection rates were higher in the sutured mesh group compared to self-gripping mesh although the results were not statistically significant. Two trials in the metaanalysis did not show any difference in the wound infection rates, while one trial showed higher infection rates with sutured mesh. The cause for the increased infection rates in the sutured mesh group is difficult to ascertain, but may be related to longer operative time and dissection needed compared to selfgripping mesh. A recent study20 on abdominal wall hernia repair has shown that operative time is a significant factor
Fig. 3 e Forest plot comparing perioperative complications for self-gripping mesh and sutured mesh from 5 trials. A ManteleHaenszel fixed-effects model was used for meta-analysis. Risk ratios are shown with 95 per cent confidence intervals.
Fig. 4 e Forest plot comparing chronic groin pain from 3 trials following the use of self-gripping mesh and sutured mesh. A ManteleHaenszel fixed-effects model was used for meta-analysis. Risk ratios are shown with 95 per cent confidence intervals.
92
t h e s u r g e o n 1 2 ( 2 0 1 4 ) 8 7 e9 3
Fig. 5 e Forest plot comparing hernia recurrence from 3 trials following the use of self-gripping mesh and sutured mesh. A ManteleHaenszel fixed-effects model was used for meta-analysis. Risk ratios are shown with 95 per cent confidence intervals.
predisposing to mesh infection, however we should be cautiously interpreted as the cause for wound infections are multifactorial and abdominal wall hernia repair is a significantly longer operation compared to inguinal hernia repair. In the present metaanalysis, three trials compared chronic groin pain16e18 and pooled analysis did not show any difference between the two groups. Four studies in this metaanalysis identified and preserved the ilioinguinal, iliohypogastric and genitofemoral nerves whenever possible.16e19 Chastan in his study has shown a significant reduction in neurological symptoms with the self-gripping mesh with only one patient out of 52 patients reporting mild discomfort in the groin.8 None of the trials in this metaanalysis obtained comparable results although 2 trials showed reduction in early postoperative pain,16,19 but no impact on long term (>3months) groin pain. This raises questions on the potential benefit of using self-gripping mesh to minimise long term pain. Larger studies with longer follow-up should clarify these issues. The summated hernia recurrence rates in this metaanalysis were 0.4% for the self-gripping mesh and 0.5% for the sutured mesh repair, and were not significantly different. These recurrent rates are comparable with laparoscopic repair inguinal hernia repair and better than non-mesh repairs.21 In addition, one trial compared patient satisfaction between the 2 mesh techniques and showed no significant difference. There are several limitations in this metaanalysis. There was no comparable data available to assess early postoperative pain, return to work and quality of life between the two mesh repair techniques. Trials recruiting a small number of patients in this metaanalysis may not have had sufficient power to recognize small differences in outcomes between self-gripping mesh and sutured mesh. While this meta-analysis does not provide data on cost-benefit analysis or longer than 1 year follow-up, early results suggests significant advantage with self-gripping mesh in reducing operating time. Further larger trials with longer follow up are needed to evaluate potential long term benefits such as chronic groin pain.
references
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mesh versus sutured mesh for Lichtenstein hernia repair. Br J Surg 2013 Mar;100(4):474e81. 18. Pierides G, Scheinin T, Remes V, Hermunen K, Vironen J. Randomized comparison of self-fixating and sutured mesh in open inguinal hernia repair. Br J Surg 2012;99:630e6. 19. Kapischke M, Schulze H, Caliebe A. Self-fixating mesh for the Lichtenstein procedureea prestudy. Langenbecks Arch Surg 2010;395:317e22.
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20. Stremitzer S, Bachleitner-Hofmann T, Gradl B, Gruenbeck M, Bachleitner-Hofmann B, Mittlboeck M, et al. Mesh graft infection following abdominal hernia repair: risk factor evaluation and strategies of mesh graft preservation. A retrospective analysis of 476 operations. World J Surg 2010 Jul;34(7):1702e9. 21. Corbitt JJ. Transabdominal preperitoneal herniorrhaphy. Surg Laparosc Endosc 1993 Aug;3:328e32.
