Tension-free hernia repair is associated with an increase in inflammatory response markers against the mesh

Inflammation in Hernia and the epigenetic control

Inflammation is much more intrinsic to hernia then is what is generally appreciated. The occurrence of hernias is associated with swelling, stress and inflammation. Surgery remains an important intervention to treat hernias and for many years, post-surgical levels of inflammatory cytokines have been evaluated to compare the different strategies for their comparative advantages. All surgical procedures elicit some sort of inflammatory response and moreover the meshes used for hernia repair are also associated with elevated inflammatory response, although some favor predominantly a pro-inflammatory response while the other meshes favor anti-inflammatory response. An estimated more than 90% of hernia repairs involve some meshes with polypropylene considered as the gold standard. Efforts are underway to modulate polypropylene meshes associated inflammation through use of alternative materials as well as modifications to polypropylene meshes themselves. In the last one decade, miRNAs have entered hernia research and the data on a role of miRNAs in different hernias is slowly emerging, providing the first evidence of epigenetics in hernia. Some reports are connecting miRNAs with inflammation in hernia. All these aspects, such as, surgery-related to mesh-related inflammation as well as miRNA-related inflammation, are discussed in this article to present an up-to-date information on the topic.

Autoimmunity and hernia mesh: fact or fiction?

BACKGROUND

There is an increasing number of patients following hernia surgery with implanted mesh reporting symptoms that could indicate autoimmune or allergic reactions to mesh. 'Allergy' to metals, various drugs, and chemicals is well recognised. However, hypersensitivity, allergy or autoimmunity caused by surgical mesh has not been proven by a scientific method to date. The aim of this study was twofold: to describe the pathophysiology of autoimmunity and foreign body reaction and to undertake a systematic review of surgical mesh implanted at the time of hernia repair and the subsequent development of autoimmune disease.

METHODS

A systematic review using the PRISMA guidelines was undertaken. Pubmed (Medline), Google Scholar and Cochrane databases were searched for all English-written peer-reviewed articles published between 2000 and 2021. The search was performed using the keywords "hernia", "mesh", "autoimmunity", "ASIA", "immune response", "autoimmune response".

RESULTS

Seven papers were included in the final analysis-three systematic reviews, three cohort studies and one case report. Much of the current data regarding the association of hernia mesh and autoimmunity relies on retrospective cohort studies and/or case reports with limited availability of cofounding factor data linked to autoimmune disease such as smoking status or indeed a detailed medical history of patients. Three systematic reviews have discussed this topic, each with a slightly different approach and none of them has identified causality between the use of mesh and the subsequent development of autoimmune disease.

CONCLUSION

There is little evidence that the use of polypropylene mesh can lead to autoimmunity. A large number of potential triggers of autoimmunity along with the genetic predisposition to autoimmune disease and the commonality of hernia, make a cause and effect difficult to unravel at present. Biomaterials cause foreign body reactions, but a chronic foreign body reaction does not indicate autoimmunity, a common misunderstanding in the literature.

Are polypropylene mesh implants associated with systemic autoimmune inflammatory syndromes? A systematic review

Purpose

The surgical implantation of polypropylene (PP) meshes has been linked to the occurrence of systemic autoimmune disorders. We performed a systematic review to determine whether PP implants for inguinal, ventral hernia or pelvic floor surgery are associated with the development of systemic autoimmune syndromes.

Methods

We searched Embase, Medline, Web of Science, Scopus, Cochrane library, clinicaltrialsregister.eu, clinicaltrails.gov and WHO-ICTR platform. Last search was performed on November 24th 2021. All types of studies reporting systemic inflammatory/autoimmune response in patients having a PP implant for either pelvic floor surgery, ventral or inguinal hernia repair were included. Animal studies, case reports and articles without full text were excluded. We intended to perform a meta-analysis. The quality of evidence was assessed with the Newcastle–Ottawa Scale. This study was registered at Prospero (CRD42020220705).

Results

Of 2137 records identified, 4 were eligible. Two retrospective matched cohort studies focused on mesh surgery for vaginal prolapse or inguinal hernia compared to hysterectomy and colonoscopy, respectively. One cohort study compared the incidence of systemic conditions in women having urinary incontinence surgery with and without mesh. These reports had a low risk of bias. A meta-analysis showed no association when comparing systemic disease between mesh and control groups. Calculated risk ratio was 0.9 (95% CI 0.82–0.98). The fourth study was a case series with a high risk of bias, with a sample of 714 patients with systemic disease, 40 of whom had PP mesh implanted.

Conclusion

There is no evidence to suggest a causal relationship between being implanted with a PP mesh and the occurrence of autoimmune disorders.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10029-021-02553-y.

Randomized and Comparative Clinical Trial of Bovine Mesh Versus Polypropylene Mesh in the Repair of Inguinal Hernias

BACKGROUND

The type of mesh (synthetic vs. biological) play integral roles in the recovery and long-term outcomes of patients undergoing hernia repair. The aim of this study was to determine whether a biological mesh from bovine pericardium is equivalent to a standard polypropylene mesh in an open inguinal hernia repair using the Lichtenstein technique.

MATERIALS AND METHODS

A prospective, randomized, double-blinded, single-center trial was conducted to evaluate the safety and efficacy of a biological mesh compared with a commonly used polypropylene mesh using Lichtenstein's inguinal hernia repair in a 6-month study. Patients were evaluated for recurrence and complications by a blinded surgeon at 1 day, 1 week, 1 month, 3 months, and 6 months after surgery.

RESULTS

A total of 132 patients were randomized into experimental group receiving the bovine mesh (n=66) and control group receiving the standard polypropylene mesh (n=66). No recurrences were diagnosed in both arms within 6-month follow-up. Patients in the experimental group reported markedly less groin pain during the 3-month postoperative assessment period compared with the control group. There were no statistically significant differences in other complications, such as incision inflammation, physical limitation, testicular problems, and foreign body sensation, between the 2 groups.

CONCLUSIONS

Biological mesh is safe and effective in repairing inguinal hernia, with comparable intraoperative and early postoperative morbidity to the synthetic mesh.

Postoperative clinical outcomes and inflammatory markers after inguinal hernia repair using local, spinal, or general anesthesia: A randomized controlled trial

Background

No consensus has yet been reached regarding the best anesthetic technique for inguinal hernia repair. This study aimed to compare postoperative clinical outcomes and inflammatory markers among patients who were anesthetized using local, spinal, or general anesthesia for inguinal hernia repair.

Methods

This randomized controlled trial included patients scheduled to undergo elective unilateral inguinal hernioplasty at Siriraj Hospital during November 2014 to September 2015 study period. Patients were randomly assigned to the local (LA), spinal (SA), or general (GA) anesthesia groups. Primary outcomes were postoperative pain at rest and on mobilization at 8 and 24 hours after surgery.

Results

Fifty-four patients were included, with 18 patients randomly assigned to each group. Patient demographic and clinical characteristics were similar among groups. There were no significant differences among groups for postoperative pain at rest or on mobilization at 8 and 24 hours after surgery. No significant differences were observed for interleukin-1β, interleukin-6, and interleukin-10 at any time points in any groups. Patients with local anesthesia was associated with less time spent in anesthesia (p = 0.010) and surgery (p = 0.009), lower intraoperative cost (p = 0.003) and total cost in hospital (p = 0.036); however, patient satisfaction in the local anesthesia group (94/100) was statistically significantly lower than the spinal and general anesthesia groups (100/100) (p = 0.010).

Conclusions

No statistically significant difference was observed among groups for postoperative pain scores, duration of hospital stays, complications, or change in inflammatory markers. However, time spent in anesthesia and surgery, the intraoperative cost and total cost for hernia repair, and patient satisfaction were significantly lower in the local anesthesia group than in the other two groups.

Polypropylene mesh and systemic side effects in inguinal hernia repair: current evidence

INTRODUCTION

Increasing awareness and regulatory body attention is directed towards the insertion of synthetic material for a variety of surgical procedures. This review aims to assess current evidence regarding systemic and auto-immune effects of polypropylene mesh insertion in hernia repair.

METHODS

The electronic literature on systemic and auto-immune effects associated with mesh insertion was examined.

RESULTS

Foreign body reaction following mesh implantation initiates an acute inflammatory cellular response. Involved markers such as IL-1, IL-6, IL-10 and fibrinogen are increased in circulation in the presence of mesh but return to normal at 7 days post operatively. Oxidative degradation of implanted mesh is likely, but no evidence exists to support systemic absorption or resulting disease effects. Variable cytokine production in healthy hosts leading to unpredictable or overwhelming response to implanted biomaterial warrants further investigation. Clinical studies show no associated long-term systemic effects with mesh.

CONCLUSION

To date, there remains no evidence to link polypropylene mesh and systemic or auto-immune symptoms. Based on current evidence, the use of polypropylene mesh is supported.

Preparation of a nano- and micro-fibrous decellularized scaffold seeded with autologous mesenchymal stem cells for inguinal hernia repair

Prosthetic meshes used for hernioplasty are usually complicated with chronic pain due to avascular fibrotic scar or mesh shrinkage. In this study, we developed a tissue-engineered mesh (TEM) by seeding autologous bone marrow-derived mesenchymal stem cells onto nanosized fibers decellularized aorta (DA). DA was achieved by decellularizing the aorta sample sequentially with physical, mechanical, biological enzymatic digestion, and chemical detergent processes. The tertiary structure of DA was constituted with micro-, submicro-, and nanosized fibers, and the original strength of fresh aorta was retained. Inguinal hernia rabbit models were treated with TEMs or acellular meshes (AMs). After implantation, TEM-treated rabbit models showed no hernia recurrence, whereas AM-treated animals displayed bulges in inguinal area. At harvest, TEMs were thicker, have less adhesion, and have stronger mechanical strength compared to AMs (P<0.05). Moreover, TEM showed better cell infiltration, tissue regeneration, and neovascularization (P<0.05). Therefore, these cell-seeded DAs with nanosized fibers have potential for use in inguinal hernioplasty.

Assessment of systemic inflammatory response after total extraperitoneal repair and Lichtenstein repair for inguinal hernia

PURPOSE

The aim of the study was assessment of the systemic inflammatory response (SIR) intensity by measuring the blood serum levels of high sensitivity C-reactive protein (hsCRP), Interleukin-6 (IL-6) and Total Leukocyte Counts of patients. The estimations were done before and after the patient underwent either open Lichtenstein or endoscopic TEP inguinal hernia repair. This is a prospective observational type of study.

METHODS

Sixty patients with a diagnosis of unilateral uncomplicated inguinal hernia were included in the study. Patients were divided into two groups. In the first group, endoscopic total extraperitoneal repair (TEP) was done, while the other group underwent Lichtenstein repair. The patient selection was random. Serum markers for SIR were measured prior to and 24 h post-surgery.

RESULTS

Total extraperitoneal repair (TEP) and open Lichtenstein inguinal hernia repair both cause a significant Systemic Inflammatory Response in the body. The rise in serum markers for SIR post-surgery was statistically significant in both the groups. The rise in serum hsCRP and IL-6 concentrations was observed to be equivocal among the two groups. Statistically significant difference was observed in serum TLC rise: Lichtenstein repair group having a higher value.

CONCLUSION

Both, open and endoscopic surgical techniques incite a systemic inflammatory response in the body. However, it cannot be conclusively stated that TEP is associated with lesser SIR compared to the Lichtenstein repair on the basis of this study.

Early assessment of bilateral inguinal hernia repair: A comparison between the laparoscopic total extraperitoneal and Stoppa approaches

BACKGROUND:

The present clinical trial was designed to compare the results of bilateral inguinal hernia repair between patients who underwent the conventional Stoppa technique and laparoscopic total extraperitoneal repair (LTE) with a single mesh and without staple fixation.

PATIENTS AND METHODS:

This controlled, randomised clinical trial was conducted at General Surgery and Trauma of the Clinics Hospital, Medical School, the University of São Paulo between September 2010 and February 2011. Totally, 50 male patients, with a bilateral inguinal hernia, older than 25 years were considered eligible for the study. The following parameters were analysed during the early post-operative period: (1) The intensity of surgical trauma, operation time, C-reactive protein (CRP) levels, white blood cell count, bleeding and pain intensity; (2) quality of life assessment; and (3) post-operative complications.

RESULTS:

LTE procedure was longer than the Stoppa procedure (134.6 min ± 38.3 vs. 90.6 min ± 41.3; P < 0.05). The levels of CRP were higher in the Stoppa group (P < 0.05) but the number of leucocytes, haematocrit, and haemoglobin were similar between the groups (P > 0.05). There was no difference in pain during the 1^st and 7^th post-operative, physical functioning, physical limitation, the impact of pain on daily activities, and the Carolinas Comfort Scale during the 7^th and 15^th post-operative (P > 0.05). Complications occurred in 88% of Stoppa group (22 patients) and 64% in LTE group (16 patients) (P < 0.05).

CONCLUSION:

The comparative study between the Stoppa and LTE approaches for the bilateral inguinal hernia repair demonstrated that: (1) The LTE approach showed less surgical trauma despite the longer operation time; (2) Quality of life during the early post-operative period were similar; and (3) Complication rates were higher in the Stoppa group.

UltraPro Hernia System, Prolene Hernia System and Lichtenstein for primary inguinal hernia repair: 3-year outcomes of a prospective randomized controlled trial

PURPOSE

Chronic pain and discomfort are common after inguinal hernia repair (IHR). In this study, results from a 3-year follow-up from a randomized controlled study comparing three different mesh repairs for postoperative pain, discomfort, Quality of Life (QoL) and patient satisfaction are reported.

METHODS

Between November 1, 2006 and January 31, 2009, 309 men, who underwent day surgery for primary unilateral inguinal hernia under local anesthesia, were randomized to three different mesh repairs; UltraPro Hernia System (U), Prolene Hernia System (P) and Lichtenstein procedure (L).

RESULTS

Preoperatively, there were no differences between groups regarding demographics, symptoms, inguinal pain or QoL (SF-36 and a hernia-specific questionnaire). Operating time, postoperative pain, complications and time to full recovery were similar. At 36 months, 21 patients indicated pain [L, n = 6, P, n = 6 and U, n = 9; VAS (median (IQR)): L 0.4 (0.2-1.7), P 0.2 (0.1-2.3) and U 1.6 (0.7-4.6), p = ns]. Physical QoL was reduced in all groups before surgery and was similarly increased to normal levels after 3 months without further changes throughout the study. Although 92 % of participants were satisfied, sixteen percent reported any discomfort from the groin (ns between groups). Five recurrences were reported (L, n = 2, P, n = 1 and U, n = 2, p = ns).

CONCLUSIONS

After 3 years of follow-up, all three procedures provided equally good results regarding, pain, discomfort and QoL and could therefore be recommended for primary IHR in LA.

Histological findings in equine testes one year after standing laparoscopic peritoneal flap hernioplasty

In order to know reproduction-related complications due to standing laparoscopic peritoneal flap hernioplasty, histological characteristics of the testicles from five stallions one year after surgery were compared with seven testicles from four healthy stallions. Moreover, the daily sperm output (DSO) was determined before (T0) and one year after surgery (T12). DSO did not show significant differences between T0 and T12. The diameter of the seminiferous tubules was significantly decreased in the samples from the hernioplasty group. The percentage of tubules with full spermatogenesis was smaller in the hernioplasty group, but the difference was not significant. It can be concluded that standing laparoscopic peritoneal flap hernioplasty produced mild histological changes in the testicular parenchyma, epididymis and pampiniform plexus after one year follow-up.

The Comparison of Inflammatory Responses and Clinical Results After Groin Hernia Repair Using Polypropylene or Polyester Meshes

The aim of this study was to compare the clinical results and the inflammatory responses against polypropylene and polyester meshes after groin hernia repair. Ninety patients with unilateral inguinal hernia randomly underwent Shouldice herniorrhaphy or Lichtenstein hernioplasty using polypropylene or polyester meshes. Venous blood samples were collected to evaluate serum interleukin-6 (IL-6) and C-reactive protein (CRP) levels. Postoperative acute and chronic pain and time to attain to normal activities were evaluated. IL-6 levels decreased to preoperative levels in all groups at 48th hour. CRP levels of mesh-implanted groups are significantly higher than preoperative level at 48th hour, while it reduced to preoperative level in Shouldice herniorrhaphy group. Patients treated with mesh repair had less postoperative acute pain and recovered more rapidly than those who underwent Shouldice herniorrhaphy. It was concluded that polypropylene and polyester meshes used in hernia repair caused similar inflammatory responses and that clinical results after groin hernia repair with these prostheses were not significantly different.

Acute systemic response to intraperitoneal implantation of polypropylene mesh/chitosan-based film composite in pigs

PURPOSE

To assess the systemic response of pigs to the intraperitoneal implantation of polypropylene mesh associated with chitosan-based film with a degree of deacetylation of 95%.

METHODS

Blood samples were collected 24 hours before, and two and seven days after surgery. Systemic reactions were evaluated based on white blood cell count, C-reactive protein, and total serum protein, albumin and globulin levels.

RESULTS

The systemic response was proportional to the composite response induced by polypropylene mesh, and the tissue inflammatory response was higher in the PP group (p=0.0033).

CONCLUSION

The polypropylene mesh/chitosan-based film composite did not elicit a systemic response in pigs.

Standing laparoscopic peritoneal flap hernioplasty of the vaginal rings does not modify the sperm production and motility characteristics in intact male horses

Laparoscopic hernioplasty techniques have been developed in the recent years to avoid the recurrence of inguinal hernias and to spare the testicles for breeding purposes in stallions. However, there have been no previous comprehensive and systematic studies of the reproductive outcomes and prognoses for stallions after inguinal hernioplasty. Therefore, the objective of this study was to assess the possible effects of one of these techniques (standing laparoscopic peritoneal flap hernioplasty) on the sperm production and motility characteristics of six healthy stallions that received this procedure based on 1-year follow-ups. There were no significant differences in the measured sperm variables (assessments based on the DSO, MOT, PMOT, VSL, VCL and VAP) during 1-year follow-ups.

Evaluation of six synthetic surgical meshes implanted subcutaneously in a rat model

The long-term efficacy and mechanical integrity of implanted materials is largely determined by early host response. Therefore, implanting materials with well-characterized tissue responses provides the greatest chance of 'one-hit' surgical successes, without repeated interventions to replace, repair or remove non-compliant biomaterials. Six synthetic meshes were implanted subcutaneously in a rat model to deduce and quantify modulations in host response, based on material fabrication variables. The materials consisted of knitting variations of polypropylene (PP), polyethyleneterephthalate (PET) and polyglycolic acid (PGA) yarns and were implanted for 2, 5, 7, 14 and 28 days before fixation and both semi- and fully quantitative histopathology. In a subcutaneous niche, material weight did not influence foreign body response. PET stimulated earlier inflammation than PP and PGA, which normalized over 28 days. Multifilament meshes recruited foreign body giant cells, which were largely absent from monofilaments. Using CD68, PGA was demonstrated to be the greatest leukocyte-activating polymer at a number of the time points analysed. This research therefore highlights that underlying polymer composition may be more over-arching in deciding the inflammatory properties of surgical meshes, based on increased macrophagic responses to PGA vs alternative base polymers of comparable weights and porosities. Copyright © 2013 John Wiley & Sons, Ltd.

Open transinguinal preperitoneal mesh repair of inguinal hernia: a targeted systematic review and meta-analysis of published randomized controlled trials

OBJECTIVE

The objective of this article is to systematically analyse the randomized, controlled trials comparing transinguinal preperitoneal (TIPP) and Lichtenstein repair (LR) for inguinal hernia.

METHODS

Randomized, controlled trials comparing TIPP vs LR were analysed systematically using RevMan® and combined outcomes were expressed as risk ratio (RR) and standardized mean difference.

RESULTS

Twelve randomized trials evaluating 1437 patients were retrieved from the electronic databases. There were 714 patients in the TIPP repair group and 723 patients in the LR group. There was significant heterogeneity among trials (P < 0.0001). Therefore, in the random effects model, TIPP repair was associated with a reduced risk of developing chronic groin pain (RR, 0.48; 95% CI, 0.26, 0.89; z = 2.33; P < 0.02) without influencing the incidence of inguinal hernia recurrence (RR, 0.18; 95% CI, 0.36, 1.83; z = 0.51; P = 0.61). Risk of developing postoperative complications and moderate-to-severe postoperative pain was similar following TIPP repair and LR. In addition, duration of operation was statistically similar in both groups.

CONCLUSION

TIPP repair for inguinal hernia is associated with lower risk of developing chronic groin pain. It is comparable with LR in terms of risk of hernia recurrence, postoperative complications, duration of operation and intensity of postoperative pain.

A single-surgeon randomized trial comparing three meshes in lichtenstein hernia repair: 2- and 5-year outcome of recurrences and chronic pain

BACKGROUND

Chronic pain may be a major long-term problem related to mesh material and operative trauma in inguinal hernioplasty.

STUDY DESIGN

Lichtenstein hernioplasty was performed under local anaesthesia in 312 patients by the same surgeon and technique between 2003 and 2005. The patients were randomized to receive a partly absorbable polypropylene-polyglactin mesh (Vypro II(®) 50 g/m(2), 104 hernias), a lightweight polypropylene mesh (Premilene Mesh LP(®) 55 g/m(2), 107 hernias) or a conventional densely woven polypropylene mesh (Premilene(®) 82 g/m(2), 101 hernias). The 2- and 5-year recurrences and pain scores were analysed.

RESULTS

Patient's characteristics and the mean duration of operation (30-32 min) were similar between the three groups. After two years, there were 6 recurrences (2 in each group) of which 3 patients were re-operated. A feeling of a foreign body and sensation of pain were comparable with all meshes. After five years, overall recurrence rate was 10/312 (3.2%) with only 4 re-operations. A feeling of a foreign body (6.5-8.1%), chronic pain (13-23%) as well as use of analgesics (0-2.9%) were similar in all groups.

CONCLUSION

There were no statistical differences between the three meshes in pain, a feeling of a foreign body or use of analgesics after 5 years of Lichtenstein hernioplasty, when the same surgeon operated all patients with exactly the same surgical technique. CLINICAL TRIAL REGISTER: NCT01295437.

Randomized prospective trial comparing clinical outcomes 3 years after surgery by Marcy repair and Prolene Hernia System repair for adult indirect inguinal hernia

PURPOSE

The use of mesh in the surgical repair of adult indirect inguinal hernias is widely recommended in Western countries, but no randomized controlled trials have so far been reported in Japan. The purpose of the present randomized prospective trial was to compare a mesh method with non-mesh method for surgical repair of primary adult indirect inguinal hernias in which the diameter of the internal inguinal ring was up to 3.0 cm (I-1 or I-2 of Japanese Hernia Society Classification).

METHODS

Patients with a primary unilateral inguinal hernia and I-1 or I-2 surgical findings were randomized to undergo either Marcy repair or Prolene Hernia System repair. Primary endpoints were recurrence, infection, and pain, with follow-up continued for 3 years postoperatively.

RESULTS

Ninety-one of 479 patients with an inguinal hernia during the study period did not meet the exclusion criteria, and 46 were allocated to Marcy repair and 45 were allocated to Prolene Hernia System repair. No recurrence was observed in either group, and no significant differences were identified between the groups in any of the primary endpoints.

CONCLUSION

This randomized prospective trial of I-1 and I-2 inguinal hernias suggests that Marcy repair is not inferior to PHS repair. A large-scale randomized controlled trial appears warranted to confirm whether to use mesh for Japanese adult I-1 and I-2 hernias.

Inflammatory reaction and neotissue maturation in the early host tissue incorporation of polypropylene prostheses

PURPOSE

The use prosthetic materials for the surgical repair of abdominal wall defects has become almost standard practice. This study was designed to assess the expression of different growth factors (VEGF/TGF-β1) and macrophages during the early host tissue incorporation of several polypropylene lightweight (PP-LW)-including one partially absorbable-and heavyweight (PP-HW) prosthetic meshes.

METHODS

Ventral defects were created in the anterior abdominal wall of New Zealand rabbits and repaired by fixing PP-LW meshes of different pore size and a low porosity PP-HW mesh to the edges of the defect. Following killing 14 days after implant, specimens were taken to examine TGF-β1/VEGF gene and protein expression by qRT-PCR and immunohistochemistry. The macrophage response was also assessed.

RESULTS

All the materials showed good host tissue incorporation, with a more severe inflammatory reaction and greater numbers of macrophages recorded in the partially absorbable LW implants. Relative amounts of VEGF mRNA were significantly lower for the LW partially absorbable implants compared with the remaining LW meshes. Protein expression of VEGF showed undetectable or minimum staining in the different groups. TGF-β1 mRNA levels were also lower in the partially absorbable group compared with one of PP-LW type of mesh. Gene expression patterns were consistent with the TGF-β1 protein levels detected.

CONCLUSIONS

The results suggest that VEGF and TGF-β1 expression were independent of mesh pore size. The expression of both growth factors and the macrophage response were correlated with the presence of biodegradable material in the mesh. The presence of absorbable material in the LW mesh gave rise to a more intense inflammatory reaction and the reduced synthesis of growth factors known to contribute to neotissue maturation.

Lichtenstein, prolene hernia system, and UltraPro Hernia System for primary inguinal hernia repair: one-year outcome of a prospective randomized controlled trial

PURPOSE

The optimal technique for open inguinal hernia repair is yet to be determined.

METHODS

Three hundred and nine male patients [median of 60 years (range, 31-75)] undergoing primary open inguinal hernia repair in local anesthesia and day-care surgery were randomly allocated to operation with the Lichtenstein technique (L), Prolene Hernia System (PHS), or UltraPro Hernia System (UHS).

RESULTS

[Median (IQR)] There were no differences in operating time [47 (40-58) vs. 50 (40-57) and 50 (42-56) min in groups L, PHS, and UHS, respectively], intra- or postoperative complications, time until return to normal workload (8 (4-14) vs. 9 (4-14), and 8 (4-14) days) or occurrence of chronic pain at 12 months (15 vs. 12, and 13 patients). Self-reported physical quality of life (SF-36) was reduced compared to matched controls preoperatively and increased similarly to levels not different from controls in all groups at 12 months postoperatively. There was one recurrence in each group during the follow-up period.

CONCLUSIONS

The Lichtenstein technique, PHS, and UHS seem all acceptable approaches for open inguinal hernia repair in local anesthesia and day-care surgery regarding perioperative course, rehabilitation, complications, recurrence rates, development of chronic groin pain, and improvement in quality of life after 12 months. However, due to reduced costs and lack of need for the exploration of the preperitoneal space, the Lichtenstein technique should be recommended as first choice.

Systematic review and meta-analysis of the use of lightweight versus heavyweight mesh in open inguinal hernia repair

BACKGROUND

The objective of this study was systematically to analyse published randomized trials comparing lightweight mesh (LWM) with heavyweight mesh (HWM) in open inguinal hernia repair.

METHODS

Randomized trials on LWM versus HWM were selected from the standard electronic databases. Reported outcomes were analysed systematically using RevMan. Pooled risk ratios were calculated for categorical outcomes, and mean differences for secondary continuous outcomes, using the fixed-effects and random-effects models for meta-analysis.

RESULTS

Nine randomized trials containing 2310 patients were included. There was significant heterogeneity among trials. There was no difference in duration of operation, postoperative pain, recurrence rate, testicular atrophy and time to return to work between LWM and HWM groups. The two mesh types had a similar risk of perioperative complications, but LWM was associated with a reduced risk of developing chronic groin pain (risk ratio (RR) 0·61, 95 per cent confidence interval 0·50 to 0·74) and a reduced risk of developing other groin symptoms, such as stiffness and foreign body sensations (RR 0·64, 0·50 to 0·81).

CONCLUSION

The use of LWM for open inguinal hernia repair was not associated with an increased risk of hernia recurrence. LWM reduced the incidence of chronic groin pain as well as the risk of developing other groin symptoms.

Randomized clinical trial of tissue glue versus absorbable sutures for mesh fixation in local anaesthetic Lichtenstein hernia repair

Background

Chronic pain may be a long-term problem related to mesh fixation and operative trauma after Lichtenstein hernioplasty. The aim of this study was to compare the feasibility and safety of tissue cyanoacrylate glue versus absorbable sutures for mesh fixation in Lichtenstein hernioplasty.

Methods

Lichtenstein hernioplasty was performed under local anaesthesia as a day-case operation in one of three hospitals. The patients were randomized to receive either absorbable polyglycolic acid 3/0 sutures (Dexon®; 151 hernias) or 1 ml butyl-2-cyanoacrylate tissue glue (Glubran®; 151 hernias) for fixation of lightweight mesh (Optilene®). Wound complications, pain, discomfort and recurrence were identified at 1 and 7 days, 1 month and 1 year after surgery.

Results

A total of 302 patients were included in the study. The mean(s.d.) duration of operation was 34(12) min in the glue group and 36(13) min in the suture group (P = 0·113). The need for analgesics was similar during the first 24 h after surgery. Five wound infections (3·4 per cent) were detected in the glue group and two (1·4 per cent) in the suture group (P = 0·448). The recurrence rate at 1 year was 1·4 per cent in each group (P = 1·000). The rates of foreign body sensation, acute and chronic pain were similar in the two groups. Logistic regression analysis showed that the type of mesh fixation did not predict chronic pain 1 year after surgery.

Conclusion

Mesh fixation without sutures in Lichtenstein hernioplasty was feasible without compromising postoperative outcome. Registration number: NCT00659542 (http://www.clinicaltrials.gov).

Short-term complications of hemorrhoidectomy in outpatient and inpatient operations in shiraz, southern iran

BACKGROUND

Today, hospitals and patients are both willing to benefit from outpatient services. Considering limits of supply, it seems that there is a need to run productive management in offering health services to prevent wasting of supplies and facilities. This study compares the complications caused by hemorrhoidectomy in outpatient and inpatient operations.

METHODS

In a cross-sectional study during 1.5 years, 208 patients without any background disease were enrolled. They were randomly allocated into two groups (inpatient and outpatient) and interviewed within two weeks after surgical operations. The data were collected through a questionnaire and physical examination. The complications in the two groups of operating theater of hospital and clinic were then compared regarding sex, occupation, education and etc.

RESULTS

One week after the surgical operation, the patients in the hospital operating theater showed significantly a better healing recovery of their wound. Other complications such as pain, hemorrhage, infection, inflammation, involuntary emission of feces and gas indicated no significant difference between the two groups. After 2 weeks, more pain was noticed in patients in the operating theaters of the hospital and in clinics, there was more infection visible. The hemorrhage, inflammation, wound healing, involuntary emission of feces and gas did not indicate a significant difference between the operating theater of hospital and the clinic. There was no significant difference regarding the patients' satisfaction in the two groups.

CONCLUSION

We recommend that for optimized use of supplies and equipments in operating theaters and to lower the cost and shorten queue of patients, grade 2 hemorrhoids are performed in the operating theater of clinics considering sterilization and safety procedures.

Comparison of three separate antiadhesive barriers for intraperitoneal onlay mesh hernia repair in an experimental model

Background

Adhesion formation is a common adverse effect in intraperitoneal onlay mesh (IPOM) surgery. Different methods of adhesion prevention have been developed, including coated meshes and separate antiadhesive barriers (SABs). In this study one type of mesh was tested with different SABs, which were fixed to the sutured mesh using fibrin sealant. The primary aim was to compare adhesion prevention between different SABs. Secondary aims were the assessment of tissue integration and evaluation of SAB fixation with fibrin sealant.

Methods

Thirty-two rats were randomized to one of three treatment groups (SurgiWrap®, Prevadh® and Seprafilm®) or a control group (no SAB). Animals were operated on with an open IPOM technique (8 per group). One macroporous polypropylene mesh per animal (2 × 2 cm) was fixed with four non-absorbable sutures. An antiadhesive barrier of 2·5 × 2·5 cm was fixed with fibrin sealant. After 30 days, adhesion formation, tissue integration, seroma formation, inflammation and vascularization were evaluated macroscopically and by histology.

Results

Prevadh® and Seprafilm® groups showed a significant reduction in adhesion formation compared with the control group. Tissue integration of the mesh was reduced in these groups. Fibrin sealant fixed the SAB to the mesh securely in all groups.

Conclusion

Prevadh® and Seprafilm® are potent materials for the reduction of adhesion formation. A potential relationship between effective adhesion prevention and impaired tissue integration of the implant was observed. Fibrin sealant proved an excellent agent for SAB fixation.

Impact of Heavy Polypropylene Mesh and Composite Light Polypropylene and Polyglactin 910 on the Inflammatory Response

The aim of the study was to analyze the acute inflammatory response after implantation of a heavyweight mesh of polypropylene (PP) compared with a composite mesh of light PP and polyglactin 910 (PG) in patients undergoing inguinal hernioplasty. A total of 30 male patients with inguinal hernia were included in the study and divided into 2 groups (PP and PP-PG) according to the mesh used. Changes of leukocytes, cytokines, growth factors, and acute phase proteins were evaluated in the sera. Leukocytes and acute phase proteins were significantly increased postoperatively in both groups, and the values were slightly higher in the PP group. Cytokine levels were significantly increased postoperatively in both groups; a slight increase was observed in the PP-PG group, especially for the proinflammatory cytokine. Growth factors decreased significantly in both groups immediately after surgery. The authors found that the use of the mesh is a stimulator of inflammatory response, and the 2 types of mesh induce a similar inflammatory response.

Commentary: Nationwide analysis of complications related to inguinal hernia surgery in Finland: a 5 year register study of 55,000 operations

BACKGROUND

The aim of this study was to evaluate the incidence of severe complications of adult inguinal hernia surgery from 2003 to 2007 using data from the Finnish National Patient Insurance Association.

METHODS

All major surgical complications are reported to the association because it handles financial compensation for patients' injuries without proof of malpractice. The number of inguinal hernioplasties was obtained from the National Hospital Discharge Registry.

RESULTS

The association received reports of 115 major and 135 moderate complications from 55,000 hernia operations. The overall complication rate was 4.5 per 1,000 hernia procedures. The distribution of injuries consisted of chronic pain (32%), infections (22%), bleeding complications (13%), urologic complications (12%), recurrence (8%), intestinal complications (7%), and miscellaneous disorders (6%). Altogether, 94 patients (38%) received financial compensation from their hospitals. On multivariate analysis, significant associations with chronic pain were found for general anesthesia, length of operation, and the presence of wound complications.

CONCLUSIONS

Chronic inguinal pain and deep infections were associated with severe long-term discomfort and financial compensation to patients with inguinal hernias in Finland.

Retraction and fibroplasia in a polypropylene prosthesis: experimental study in rats

BACKGROUND

The treatment of hernia, independent of anatomical site and technique utilized, generally involves using prostheses, which may cause complications, despite their unarguable advantage in allowing safe reinforcement. An example of this is possible retraction, which causes discomfort and hernia recurrence. Polypropylene is still the most often used biomaterial of the great number available. The purpose of this study is to evaluate the amount of retraction of the polypropylene mesh, as well as the histological reactions that accompany this phenomenon.

METHODS

Polypropylene meshes (Marlex) were inserted in an anterior position to the whole abdominal aponeurosis of 25 Wistar rats (Rattus norvegicus albinus). The animals were divided into groups and another intervention was performed 7, 28, and 90 days later to measure the dimensions of the prostheses and to calculate the final area. Histological analysis was performed with hematoxylin-eosin to evaluate neutrophils, macrophages, giant cells, and lymphocytes surrounding the mesh threads in ten random fields of each slide.

RESULTS

Seven days after the mesh was inserted, the mean rate of retraction was 1.75% (P = 0.64); at 28 days, it was 3.75% (P = 0.02); and at 90 days, it was 2.5% (P = 0.01). As to the histological analysis, there was a total decline of neutrophils and a progressive increase of macrophages, giant cells, and lymphocytes proportional to the post-implant time of the mesh (P < 0.05).

CONCLUSION

There was a statistically significant retraction of 3.75% at 28 days and 2.5% at 90 days after the prosthesis was inserted. There is a well-established sequence of cellular events which aim at synthesizing new connective tissue to reinforce the mesh.

The effect of the type of intraperitoneally implanted prosthetic mesh on the systemic inflammatory response

BACKGROUND

The purpose of this study was to determine any differences in the systemic inflammatory response after the intraperitoneal implantation of three different types of polypropylene mesh.

METHODS

Thirty-two male New Zealand rabbits underwent a 6-cm midline incision and opening of the peritoneal cavity. The animals were randomly divided into four groups. In groups A, B, and C, there was an intraperitoneal placement of polypropylene mesh, titanium-coated polypropylene mesh, and composite polypropylene/e-PTFE mesh, respectively. Group D received a sham operation. Blood was sampled preoperatively and at 6, 24, 48, and 168 h postoperatively to measure white blood cell count (WBC), tumor necrosis factor-alpha (TNF-alpha), and malondialdehyde (MDA).

RESULTS

Statistically significant elevations of WBC, TNF-alpha and MDA were observed in all four groups at 6, 24, and 48 h postoperatively (P<0.05). There were no statistically significant differences in WBC, TNF-alpha, and MDA between groups A, B, and C at any time interval. However, a statistically significant elevation of WBC (P<0.05) and TNF-alpha (P<0.05) was observed between each of the groups with mesh implantation and group D at 24 h postoperatively.

CONCLUSION

Intraperitoneal mesh implantation induces mild systemic inflammatory response regardless of the type of implanted mesh.

Impact of Different Texture of Polypropylene Mesh on the Inflammatory Response

Over the past decade, hernia surgery has undergone a considerable transformation with the use of prosthetic materials. The most used polypropylene meshes induce a rapid acute inflammatory response followed by chronic foreign body reaction. Many factors influence this response such as density, size, physical characteristics, different texture and porosity of each biomaterial. The aim of this study is to assess whether the implant of monofilament or multifilament meshes, in the inguinal hernioplasty, determine a different inflammatory response. Thirty-two male patients were included in the study and were randomly divided into two groups. In the first group (MO) inguinal hernioplasty was performed using monofilament polypropylene mesh, while in the second one (MU) multifilament prosthesis was used. Peripheral venous blood samples were collected 24 hours before surgery and then 6,24,48 and 168 hours posto-peratively. Modifications in leukocyte count, C-reactive protein (CRP), alpha-1 antitrypsin (α1-AT), interleukin (IL)-1, IL-6, IL-1 ra and IL-10 serum levels were recorded at all sampling times. We present evidence that serum levels of CRP, (α1-AT), leukocytes and cytokines were significantly increased post-operatively in both groups, returning to basal values 168 hours afterwards. In particular, the production of all pro-inflammatory mediators was higher in the MU group, whereas the anti-inflammatory cytokine (IL-10, IL-1ra) production was higher in MO patients. Our results indicate that polypropylene multifilament mesh allows a higher intense acute inflammatory response as compared to monofilament mesh implantation.

Anatomical basis of neuropathies and damage to the ilioinguinal nerve during repairs of groin hernias. (about 100 dissections)

Surgical access to the inguinal region, notably during hernia repairs, exposes the ilioinguinal nerve to the risk of damage at the origin of the neuralgia. The incidence of these post-operative neuropathies and their medicolegal consequences justify this study about the anatomical variations of the ilioinguinal nerve. With the aim of preventing its damage during repairs of groin hernias and identifying the factors of onset of chronic spontaneous neuropathy of the ilioinguinal nerve, we dissected 100 inguinal regions of 51 fresh adult corpses. The nerve was absent in seven cases and double in one case. Out of the 94 ilioinguinal nerves observed, we analyzed the path in relation to the inguinal ligament and the connections with the walls of the inguinal canal and its content. The ilioinguinal nerve travels along the superficial surface of the internal oblique muscle, passing on average 1.015 cm from the inguinal ligament. In one case, the fibers of the internal oblique muscle spanned it in several places. The nerve was antero-funicular in 78.72% of cases and perforated the fascia of the external oblique in 28.72% of cases. The terminal division took place in the inguinal canal in 86% of cases, with terminal branches that sometimes perforated the fascia of the external oblique. These results enabled us to better understand the etiopathogenic aspects of certain neuropathies of the groin and to propose techniques useful for the protection of the nerve during repairs of groin hernias.

Does the approach to the groin make a difference in hernia repair?

BACKGROUND

Laparoscopic and open preperitoneal hernia repair techniques both use the preperitoneal space. This study investigated whether the surgical approach to the inguinal canal affects outcome measures.

METHODS

One hundred sixty patients with inguinal hernia were assigned randomly into open anterior (42), open preperitoneal (39), laparoscopic transabdominal preperitoneal (39), and laparoscopic total extraperitoneal (40) groups according to the surgical method. The peroperative serum tumor necrosis factor-alpha (TNF-alpha) levels, interleukin-6 (IL-6) levels, VAS scores at 6 and 48 h, per- and postoperative complications, and recurrence rates were determined as main variables.

RESULTS

The serum IL-6 levels were 335 +/- 1.8, 283 +/- 1.8, 283 +/- 1.4, and 269.3 +/- 1.6 pg/ml in the open anterior, posterior, transabdominal preperitoneal, and total extraperitoneal groups, respectively (P < 0.01). The TNF-alpha levels were highest in the open anterior group. The pain scores were lower in groups undergoing the posterior approach than in the open anterior approach group.

CONCLUSION

The approach to the inguinal canal through the preperitoneal space appears to be less invasive than the transinguinal anterior approach.

Histopathological alterations of the vas deferens in rats exposed to polypropylene mesh

OBJECTIVE

To assess the histological and physiological effects of polypropylene mesh for inguinal herniorraphy, as it can cause lesions in the vas deferens in 0.3-2.0%, leading to infertility, and induces an inflammatory process and adjacent fibrosis, strengthening the posterior inguinal wall.

MATERIALS AND METHODS

In all, 40 male albino rats (3 months old) had bilateral vas deferens dissection followed by mesh implantation on one side; the contralateral side was used as the control. The rats were killed 90 (group 1) and 120 (group 2) days later, and the vas deferens, epididymides and testicles assessed histopathologically.

RESULTS

There was a foreign-body reaction after mesh implantation, but not in the controls. The mean lumen dilatation in regions proximal to the mesh in groups 1 and 2 was 0.468 and 0.371 mm(2), respectively, and all the sections had spermatozoids. The mean dilatation in control groups 1 and 2 was 0.239 and 0.170 mm(2), respectively, with spermatozoids present in 58% and 75%, respectively (significant, P < 0.05). In group 1 the wall thickness of mesh-implanted segments reduced to 0.177 mm, and in segments proximal to the mesh to 0.099 mm; the control segment was 0.298 mm (P < 0.05). In group 2 the mean thickness of mesh-implanted and proximal segments was 0.134 and 0.224 mm, respectively, while in the control it was 0.284 mm (not significant). There was loss of mucosal folding in all segments proximal to the mesh but not in the control. The epididymides and testicles were unchanged.

CONCLUSION

Polypropylene mesh induces a foreign-body reaction, with histological changes in the vas deferens that cause functional obstruction, with dilatation and spermatozoid repression.

A single-surgeon randomized trial comparing three composite meshes on chronic pain after Lichtenstein hernia repair in local anesthesia

BACKGROUND

Chronic pain may be a long-term problem related to operative trauma and mesh material in Lichtenstein hernioplasty.

STUDY DESIGN

Inguinal hernioplasty was performed under local anesthesia in 228 patients (232 hernias) in day-case surgery by the same surgeon and exactly by the same surgical technique. The patients were randomized to receive either a partly absorbable polypropylene-polyglactin mesh (Vypro II(R) 50 g/m(2), 79 hernias), a lightweight polypropylene mesh (Premilene Mesh LP(R) 55 g/m(2), 75 hernias) or a conventional densely woven polypropylene mesh (Premilene(R) 82 g/m(2), 78 hernias). Pain, patients discomfort and recurrences of hernias were carefully followed at days 1, 7, 1 month, 1 and 2 years after surgery.

RESULTS

The duration of operation (29-33 min) and the amount of local anesthetic (55-57 ml) were similar in the three groups. Two wound infections and four hematomas were detected with no difference between the meshes. Immediate pain reaction up to 1 month was statistically equal among the three meshes. After 2 years of follow-up, there were five recurrences (two in the Vypro group, one in the Premilene LP and two in the Premilene). A feeling of a foreign body, sensation of pain and patient's discomfort were similar with all meshes.

CONCLUSION

There was no difference of pain and quality of life among a conventional polypropylene mesh, lightweight mesh or partly absorbable mesh in 2 years of follow-up, when the same surgeon operated on all patients with exactly the same technique.

Intra-Abdominal Placement of Antimicrobial-Impregnated Mesh is Associated with Noninfectious Fever

The antimicrobial, silver/chlorhexidine, when impregnated on mesh has been demonstrated to resist mesh infection in in vitro and in vivo models. The clinical, human systemic response to intraperitoneal placement of silver/chlorhexidine-impregnated mesh has not been investigated to date. Between October 2002 and November 2004, all in-patients undergoing laparoscopic ventral hernia repair were retrospectively analyzed. All repairs used expanded polytetraflouroethylene (ePTFE) Dual Mesh (DM) or ePTFE impregnated with silver/chlorhexidine, Dual Mesh Plus (DM+). Patient demographics, hernia characteristics, mesh type, operative details, and hospital course data were collected. Noninfectious fevers were defined as a temperature greater than 100.4 F without an identified source. Standard statistical methods were used. During the 2-year study period, 120 patients underwent laparoscopic ventral hernia repair (DM = 55, DM+ = 65). The two groups were similarly matched in terms of age, body mass index, American Society of Anesthesiologists score, defect size, and mesh size. Postoperative fever without an identified source occurred in 10 (18.2%) patients with DM and in 25 (38.5%) patients using DM+ (P = 0.015). A multivariant analysis revealed that only mesh type and body mass index predicted postoperative fever. All fevers resolved within the first 72 hours in the DM patients; however, 16 per cent of the DM+ group had persistent fevers of unknown origin after 72 hours. Within the DM+ group, patients with postoperative fevers had significantly longer postoperative stays (4.8 days vs 3.0 days; P = 0.009). The use of antimicrobial-impregnated ePTFE mesh with silver/chlorhexidine in laparoscopic ventral hernia repair is associated with noninfectious postoperative fever. In our patients, the evaluation and management of these fevers resulted in a significantly longer hospital stay.

Modifications in the production of cytokines and growth factors in drainage fluids following mesh implantation after incisional hernia repair

BACKGROUND

The aim of this study was to evaluate changes in the production of some cytokines (interleukins [ILs]-6, -10, -1, and -1ra), vascular endothelial growth factor, and beta-fibroblast growth factor after polypropylene mesh implantation.

METHODS

Twenty female patients were divided into 2 groups. In 1 group, hernia repair was performed with conventional sutures (CR), whereas in the other group polypropylene mesh (MR) was used. Growth factors and cytokines production was analyzed in wound drain fluids based on the amount produced during 24 hours.

RESULTS

IL-1 increased substantially in MR patients on postoperative days 1 and 2. IL1-ra and IL-10 production was always significantly higher in CR patients. IL-6 production did not show any considerable difference between the 2 groups. Vascular endothelial growth factor production was significantly higher in the MR than the CR group at all time points, whereas beta-fibroblast growth factor production was higher in the MR than the CR group only on postoperative day 1.

COMMENTS

Our data suggest that different surgical procedures induce various levels of inflammation and that implantation of prostheses significantly stimulates the inflammatory response.

Systemic inflammatory response in erderly patients following hernioplastical operation

The number of old and oldest old patients undergoing surgery of varying severity is increasing. Ageing is a process that changes the performances of most physiological systems and increases susceptibility to diseases and death; accordingly, host responses to surgical stress are altered with ageing and the occurrence of age-related increase in susceptibility to post-operative complications has been claimed. Twenty-four male patients undergoing Lichtenstein (LH) hernioplasty for unilateral inguinal hernia were included in this study and divided in two groups (Young and Old respectively), according to their age. As expression of the acute phase response, we measured changes in concentration of pro-inflammatory cytokines Tumor necrosis factor-α and Interleukin-1β, leukocytes, acute phase proteins C-reactive protein and α 1-antitrypsin. Elderly humans showed prolonged and strong inflammatory activity compared to younger subjects in response to surgical stress, indicating that the acute-phase response to surgical stress of elderly humans varies from that of the young, showing initial hyperactivity and a delayed termination of the response. Thus, the acute phase response to surgical stress is higher in old subjects, but the clinical significance of this remains unclear. It is not known whether a causal relationship exists between this stronger acute phase response and the increases in susceptibility to post-operative complications observed in aged patients.