A systematic review of outcomes following repair of complex ventral incisional hernias with biologic mesh

Long-term outcomes of PGA-TMC absorbable synthetic scaffold in both clean and contaminated ventral hernia repairs

BACKGROUND

Biosynthetic meshes afford the cost advantages of being made from fully synthetic material, but are also biodegradable, making them a versatile option that can be used in both clean and contaminated cases. The aim of this study is to evaluate the safety profile and long-term outcomes of using GORE BIO-A (BIO-A) as an adjunct to abdominal wall reconstruction in all wound classes.

METHODS

A retrospective review identified patients undergoing abdominal hernia repair using BIO-A from October 2008 to June 2018. The primary outcome was hernia recurrence rate. Only patients with at least 6-month follow-up were included when looking at recurrence rates. Secondary outcomes included 30-day morbidity categorized according to CDC Surgical Site Infection Criteria, return to operating/procedure room (RTOR), 30-day readmission, length of stay (LOS), and mortality.

RESULTS

A total of 207 patients were identified, CDC Wound Classification breakdown was 127 (61.4%), 41 (19.8%), 14 (6.8%), and 25 (12.1%) for wound classes I, II, III, and IV, respectively. Median follow-up was 55.4 months (range 0.2-162.4). Overall recurrence rate was 17.4%. Contaminated cases experienced higher recurrence rates (28.8% versus 10.4%, p = 0.002) at a mean follow up of 46.9 and 60.8 months for contaminated and clean patients, respectively. Recurrent patients had higher BMI (32.4 versus 28.4 kg/m2, p = 0.0011), larger hernias (162.2 versus 106.7 cm2, p = 0.10), higher LOS (11.1 versus 5.6 days, p = 0.0051), and higher RTOR rates (16.7% versus 5.6%, p = 0.053). 51 (24.5%) patients experienced some morbidity, including 19 (9.2%) surgical site occurences, 7 (3.4%) superficial surgical site infections, 16 (7.7%) deep surgical site infections, and 1 (0.5%) organ space infection.

CONCLUSION

This study affirms the use of biosynthetic mesh as a cost-effective alternative in all wound classifications, yielding good outcomes, limited long-term complications, and low recurrence. rates.

Amniotic fluid allograft enhances the host response to ventral hernia repair using acellular dermal matrix

Ventral hernia repair (VHR) with acellular dermal matrix (ADM) has high rates of recurrence that may be improved with allogeneic growth factor augmentation such as amniotic fluid allograft (AFA). We hypothesized that AFA would modulate the host response to improve ADM incorporation in VHR. Lewis rats underwent chronic VHR with porcine ADM alone or with AFA augmentation. Tissue harvested at 3, 14, or 28 days was assessed for region-specific cellularity, and a validated histomorphometric score was generated for tissue incorporation. Expression of pro-inflammatory (Nos1, Tnfα), anti-inflammatory (Arg1, Il-10, Mrc1) and tissue regeneration (Col1a1, Col3a1, Vegf, and alpha actinin-2) genes were quantified using quantitative reverse-transcription polymerase chain reaction. Amniotic fluid allograft treatment caused enhanced vascularization and cellularization translating to increased histomorphometric scores at 14 days, likely mediated by upregulation of pro-regeneration genes throughout the study period and molecular evidence of anti-inflammatory, M2-polarized macrophage phenotype. Collectively, this suggests AFA may have a therapeutic role as a VHR adjunct.

Platelet-rich plasma enhances mechanical strength of strattice in rat model of ventral hernia repair

Incisional hernia is a common complication of hernia repair despite the development of various synthetic and bio-synthetic repair materials. Poor long-term mechanical strength, leading to high recurrence rates, has limited the use of acellular dermal matrices (ADMs) in ventral hernia repair (VHR). Biologically derived meshes have been an area of increasing interest. Still these materials bring the risk of more aggressive immune response and fibrosis in addition to the mechanical failures suffered by the synthetic materials. Platelet-rich plasma (PRP), a growth-factor-rich autologous blood product, has been shown to improve early neovascularization, tissue deposition, and to decrease the rates of recurrence. Here, we demonstrate that PRP promotes the release of growth factors stromal derived factor (SDF)-1, transforming growth factor-beta, and platelet-derived growth factor in a dose-dependent manner. Additionally, we utilize an aortic ring angiogenesis assay to show that PRP promotes angiogenesis in vitro. A rat model of VHR using StratticeTM ADM demonstrates similar findings in vivo, corresponding with the increased expression of vascular endothelial growth factor and collagen type 1 alpha 1. Finally, we show that the molecular and cellular activity initiated by PRP results in an increased mechanical stiffness of the hernia repair mesh over time. Collectively, these data represent an essential step in demonstrating the utility and the mechanism of platelet-derived plasma in biomaterial-aided wound healing and provide promising preclinical data that suggest such materials may improve surgical outcomes.

Biologic mesh is non-inferior to synthetic mesh in CDC class 1 & 2 open abdominal wall reconstruction

BACKGROUND

Biologic mesh has historically been used in contaminated abdominal wall reconstructions (AWRs). No study has compared outcomes of biologic and synthetic in clean and clean-contaminated hernia ventral hernia repair.

METHODS

A prospective AWR database identified patients undergoing open, preperitoneal AWR with biologic mesh in CDC class 1 and 2 wounds. Using propensity score matching, a matched cohort of patients with synthetic mesh was created. The objective was to assess recurrence rates and postoperative complications.

RESULTS

Fifty-eight patients were matched in each group. Patient in the biologic group had higher rates of immunosuppression, history of transplantation, and inflammatory bowel disease (p ≤ 0.05). Operative variables were comparable for biologic vs synthetic, including defect size (230.5 ± 135.4 vs 268.7 ± 194.5 cm², p = 0.62), but the synthetic mesh group had larger meshes placed (575.6 ± 247.0 vs 898.8 ± 246.0 cm² p < 0.0001). Wound infections (15.5% vs 8.9%, p = 0.28) were equivalent, and recurrence rates (1.7% vs 3.4%, p = 1.00) were similar on follow up (19.3 ± 23.3 vs 23.3 ± 29.7 months, p = 0.56).

CONCLUSIONS

In matched, lower risk, complex AWR patients with large hernia defects, biologic and synthetic meshes have equal outcomes.

Mesh in Elective Hernia Repair: 10-Year Experience with over 6,000 Patients

BACKGROUND

The use of mesh in hernia repair has faced intense scrutiny, leading patients to become fearful of its use, despite its benefits in reducing hernia recurrence. We report a single institutional experience in performing hernia repair with mesh in terms of hernia-specific outcomes, mesh-related complications, and patient-reported quality of life.

STUDY DESIGN

Patients who underwent abdominal wall hernia repair with mesh at a single institution were identified from a prospectively maintained quality database. Demographic, perioperative, and postoperative outcomes data were analyzed. Surgical Outcomes Measurements System (SOMS) and Carolinas Comfort Scale (CCS) surveys were administered pre- and postoperatively at 3 weeks, 6 months, 1, 2, and 5 years.

RESULTS

Between 2010 and 2020, a total of 6,387 patients underwent abdominal hernia repair with mesh. Inguinal hernia repairs made up the majority (65%) of the operations. Rates of mesh infection varied by hernia type, with lower rates after umbilical (0.0%) and inguinal (0.4%) repair, and highest after incisional repair (1.3%). Similarly, mesh explantation rates were low after umbilical and inguinal repair (0.0% and 0.4%, respectively) and highest after incisional repair (3.0%). Scores on all SOMS domains were significantly improved from baseline (all p < 0.05). On CCS, 2.9%, 3.3%, and 4.4% of patients reported severe or disabling symptoms postoperatively at 1, 2, and 5 years, respectively.

CONCLUSIONS

Rates of mesh-related complications vary by hernia type. A majority of patients report excellent long-term quality of life, although a relatively large percentage of patients experience severe or disabling symptoms at long-term follow-up.

Biologic Mesh in Surgery: A Comprehensive Review and Meta-Analysis of Selected Outcomes in 51 Studies and 6079 Patients

BACKGROUND

In recent decades, biologic mesh (BM) has become an important adjunct to surgical practice. Recent evidence-based clinical applications of BM include but are not limited to: reconstruction of abdominal wall defects; breast reconstruction; face, head and neck surgery; periodontal surgery; other hernia repairs (diaphragmatic, hiatal/paraesophageal, inguinal and perineal); hand surgery; and shoulder arthroplasty. Prior systematic reviews of BM in complex abdominal wall hernia repair had several shortcomings that our comprehensive review seeks to address, including exclusion of laparoscopic repair, assessment of risk of bias, use of an acceptable meta-analytic method and review of risk factors identified in multivariable regression analyses.

MATERIALS AND METHODS

We sought articles of BM for open ventral hernia repair reporting on early complications, late complications or recurrences and included minimum of 50. We used the quality in prognostic studies risk of bias assessment tool. Random effects meta-analysis was applied.

RESULTS

This comprehensive review selected 62 articles from 51 studies that included 6,079 patients. Meta-analytic pooling found that early complications are present in about 50%, surgical site occurrences (SSOs) in 37%, surgical site infections (SSIs) in 18%, reoperation in 7%, readmission in 20% and mortality in 3%. Meta-analytic estimates of late outcomes included overall complications (42%), SSOs (40%) and SSIs (22%). Specific SSOs included seroma (14%), hematoma (4%), abscess (10%), necrosis (5%), dehiscence (8%) and fistula formation (5%). Reoperation occurred in about 17%, mesh explantation in 9% and recurrence in 36%.

CONCLUSION

Estimates of nearly all outcomes from individual studies were highly heterogeneous and sensitivity analyses and meta-regressions generally failed to explain this heterogeneity. Recurrence is the only outcome for which there are consistent findings for risk factors. Bridge placement of BM is associated with higher risk of recurrence. Prior hernia repair, history of reintervention and history of mesh removal were also risk factors for increased recurrence.

Clinical outcomes and quality of life associated with the use of a biosynthetic mesh for complex ventral hernia repair: analysis of the "Italian Hernia Club" registry

With the development of newer meshes and approaches to hernia repair, it is currently difficult to evaluate their performances while considering the patients' perspective. The aim of the study was to assess the clinical outcomes and quality of life consequences of abdominal hernia repairs performed in Italy using Phasix and Phasix ST meshes through the analysis of real-world data to support the choice of new generation biosynthetic meshes. An observational, prospective, multicentre study was conducted in 10 Italian clinical centres from May 2015 to February 2018 and in 15 Italian clinical centres from March 2018 to May 2019. The evaluation focused on patients with VHWG grade II-III who underwent primary ventral hernia repair or incisional hernia intervention with a follow-up of at least 18 months. Primary endpoints included complications' rates, and secondary outcomes focused on patient quality of life as measured by the EuroQol questionnaire. Seventy-five patients were analysed. The main complications were: 1.3% infected mesh removal, 4.0% superficial infection requiring procedural intervention, 0% deep/organ infection, 8.0% recurrence, 5.3% reintervention, and 6.7% drained seroma. The mean quality of life utility values ranged from 0.768 (baseline) to 0.967 (36 months). To date, Phasix meshes have proven to be suitable prostheses in preventing recurrence, with promising outcomes in terms of early and late complications and in improving patient quality of life.

Retrospective analysis of defect reconstruction after abdominal wall tumor resection in 30 patients

PURPOSE

It is difficult to manage the full-thickness defect that is created by radical resection of an abdominal wall tumor. This report aimed to review our institutional experience with immediate reconstruction using mesh reinforcement after abdominal wall tumor resection.

METHODS

We retrospectively examined patients who underwent abdominal wall tumor resection with immediate mesh-reinforced reconstruction between April 2014 and November 2018. The patients' records were reviewed to collect data regarding their demographic characteristics, surgical procedures, and complications.

RESULTS

We identified 30 eligible patients, including 5 who underwent simultaneous resection of affected intra-abdominal organs or tissues. The median size of the resulting abdominal wall defect was 60 cm² (interquartile range: 32-127.5 cm²) and the median mesh size was 150 cm² (interquartile range: 150-225 cm²). The median operative time was 85 min (interquartile range: 60-133.8 min), the mean hospital stay was 19.4 ± 9.0 days, and the mean follow-up period was 28.6 ± 16.0 months. The complications included seroma (n = 4), infection (n = 2), massive hematoma (n = 1), and abnormal sensation (n = 3). Tumor recurrence was observed in two patients, and three patients died because of cancer progression. No patient developed a ventral hernia or abdominal bulging.

CONCLUSION

Immediate mesh-reinforced reconstruction is feasible and effective for patients who require abdominal wall tumor resection.

Single-stage repair of contaminated hernias using a novel antibiotic-impregnated biologic porcine submucosa tissue matrix

Background

Single-stage repair of incisional hernias in contaminated fields has a high rate of surgical site infection (30–42%) when biologic grafts are used for repair. In an attempt to decrease this risk, a novel graft incorporating gentamicin into a biologic extracellular matrix derived from porcine small intestine submucosa was developed.

Methods

This prospective, multicenter, single-arm observational study was designed to determine the incidence of surgical site infection following implantation of the device into surgical fields characterized as CDC Class II, III, or IV.

Results

Twenty-four patients were enrolled, with 42% contaminated and 25% dirty surgical fields. After 12 months, 5 patients experienced 6 surgical site infections (21%) with infection involving the graft in 2 patients (8%). No grafts were explanted.

Conclusions

The incorporation of gentamicin into a porcine-derived biologic graft can be achieved with no noted gentamicin toxicity and a low rate of device infection for patients undergoing single-stage repair of ventral hernia in contaminated settings.

Trial registration

The study was registered March 27, 2015 at www.clinicaltrials.gov as NCT02401334.

Absorbable Polyglactin vs. Non-Cross-linked Porcine Biological Mesh for the Surgical Treatment of Infected Incisional Hernia

BACKGROUND

The use of absorbable meshes during contaminated or infected incisional hernia (IH) repair is associated with high morbidity and recurrence rates. Biological meshes might be more appropriate but have been described in highly heterogeneous series. This study aimed at comparing the efficacy of absorbable vs. biological meshes for the treatment of contaminated or infected IH in a homogeneous series with a standardized technique.

METHODS

Data of all patients operated on between 2008 and 2015 for contaminated or infected IH, using an absorbable (A) Vicryl® or a biological (B) Strattice® mesh, were reviewed. Patient characteristics, infectious complication rates, and recurrence-free outcome (RFO) were compared between the two groups. A propensity score methodology was applied to a Cox regression model to deal with unbalanced characteristics between groups.

RESULTS

Patient demographics in A (n = 57) and in B (n = 24) were similar except that B patients had larger parietal defects (p < 0.001) and higher Center for Disease Control (CDC) wound class (p = 0.034). Patients in A had statistically significantly more postoperative early (61.4% vs. 33.3%, p = 0.03) and late (31.2% vs. 8.3%, p = 0.046) infectious complications. Six-, 12-, and 36-month RFO rates were 77%, 47%, and 24%, and 96%, 87%, and 82% in A and B, respectively, p < 0.001. Raw multivariable Cox regression analysis found that B (HR = 0.1, 95% CI [0.03-0.34], p < 0.001) was independently associated with prolonged RFO (HR = 0.091, 95% CI [0.045-0.180], p < 0.001).

CONCLUSION

Biological meshes seem to be superior to absorbable meshes in patients with contaminated or infected incisional hernia. These results need to be confirmed by prospective randomized trials.

Mesh fistula after ventral hernia repair: What is the optimal management?

BACKGROUND

A mesh-related intestinal fistula is an uncommon and challenging complication of ventral hernia repair. Optimal management is unclear owing to lack of prospective or long-term data.

METHODS

We reviewed our prospective data for mesh-related intestinal fistulas from 2004 to 2017and compared suture repair versus ventral hernia repair with mesh at the time of mesh-related intestinal fistula takedown.

RESULTS

Eighty-two mesh-related intestinal fistulas were treated; none of the fistulas had closed spontaneously, and all fistula persisted at the time of our treatment. Mean age was 61 ± 12 years with 33-month follow-up. Comorbidities were similar between groups. Defects were 2.5-times larger in ventral hernia repair with mesh (324 ± 392 cm² vs 1301 ± 133 cm²; P = .044). Components separation (64% vs 21%; P = .0003) and panniculectomy (35% vs 7%; P = .0074) were more common in ventral hernia repair with mesh. Mortality occurred in 4 patients. Complications were similar. In patients undergoing ventral hernia repair with non-bridged, acellular, porcine dermal matrix, hernia recurrence was less than in patients without mesh (26% vs 66%; P = .0030). Only partial excision of the mesh involved with the fistula resulted in a substantial increase in developing another fistula (29% vs 6%; P < .05).

CONCLUSION

Patients undergoing preperitoneal ventral hernia repair with mesh for mesh-related intestinal fistula had a lesser rate of hernia recurrence and similar complications compared to suture repair despite larger hernias. Complete mesh excision decreases the risk of fistula recurrence. We maintain that ventral hernia repair with mesh during mesh-related intestinal fistula takedown represents the best opportunity for a durable herniorrhaphy.

Resistance of Synthetic and Biologic Surgical Meshes to Methicillin-Resistant Staphylococcus aureus Biofilm: An In Vitro Investigation

Surgical meshes have become the standard procedure for a variety of surgical applications with 20 million meshes being implanted each year. The popularity of mesh usage among surgeons is backed by the multiple studies that support its functionality as a tool for improving surgical outcomes. However, their use has also been associated with infectious surgical complications and many surgeons have turned to biologic meshes. While there have been several studies investigating synthetic meshes, there is limited data comparing synthetic and biologic meshes in vitro in an infection model. This study evaluates the in vitro susceptibility of both synthetic and biologic meshes to single-species methicillin-resistant Staphylococcus aureus (MRSA) biofilms. This research compares biofilm biomass, average thickness, and coverage between the three meshes through florescent in situ hybridization (FISH), confocal scanning microscopy (CSLM), and image analysis. We also report the varying levels of planktonic and attached bacteria through sonication and cfu counts. While the data illustrates increased biofilm formation on biologic mesh in vitro, the study must further be investigated in vivo to confirm the study observations.

A novel tool to evaluate bias in literature on use of biologic mesh in abdominal wall hernia repair

PURPOSE

Biologic meshes are being increasingly used for abdominal hernia repair in high-risk patients or patients with a previous history of wound infection, due to their infection-resistant properties. Several studies have been carried out to assess whether biologic mesh is superior to synthetic mesh, as well as to establish guidelines for their use. Unfortunately, most of these studies were not rigorously designed and were vulnerable to different types of bias. The systematic reviews that have been published so far on this topic contain the same biases and limitations of the primary articles that are analyzed. The lack of a literature review on the bias on the use of biological mesh prompted us to conduct the literature search, assessment and plan this article.

METHODS

We performed a literature search in PubMed, Embase and Cochrane databases of systematic reviews on biologic mesh for ventral hernia repair. The literature review was conducted using the Population, Intervention, Comparisons, Outcomes and Design approach. We identified 40 studies that matched the stringent criteria we had set. We then created a 13-point instrument to assess for bias and applied it on the primary studies that we intended to analyze.

RESULTS

Most primary studies are case series or case reports of patients undergoing abdominal hernia repair with biologic mesh, without any comparison group, and the inclusion of cases was only specified to be consecutive in 6 out of 40 cases. In terms of assessing outcomes, in none of the 40 articles were the outcome assessors blinded to the intervention or exposure status of participants.

CONCLUSION

The instrument that we created could allow to assess the risk of bias in different kind of studies. Our assessment of the studies based on the criteria that we had set up in the instrument clearly identified that further research needs to be done due to the lack of unbiased studies regarding the use of biologic meshes for abdominal hernia repair.

Long-term clinical, radiological, and histological follow-up after complex ventral incisional hernia repair using urinary bladder matrix graft reinforcement: a retrospective cohort study

Background

Complex ventral incisional hernia repair represents a challenging clinical condition in which biologically derived graft reinforcement is often utilized, but little long-term data inform that decision. Urinary bladder matrix (UBM) has shown effectiveness in diverse clinical settings as durable reinforcement graft material, but it has not been studied over a long term in ventral incisional hernia repair. This study evaluates the clinical, radiographic, and histological outcome of complex incisional hernia repair using UBM reinforcement with 12–70 months of follow-up.

Methods

A single-arm, retrospective observational study of all ventral incisional hernia repairs utilizing UBM reinforcement over a 6-year time frame by a single surgeon was performed. Patients were assessed in long-term follow-up clinically and with the Carolina Comfort Scale. A subset of patients was assessed with abdominal wall ultrasound or CT scan. Three patients had abdominal wall fascial biopsies years after the incisional hernia repair with UBM graft, and the histology is analyzed.

Results

64 patients underwent repair of complex incisional hernias with UBM graft reinforcement by a single surgeon. 42 patients had concomitant procedures including large or small bowel resection, excision of infected mesh, evacuation of abscess or hematoma, cholecystectomy, or panniculectomy with abdominoplasty. 16 patients had ostomies at the time of repair. Median follow-up time is 36 months, with a range of 12–70 months. Nine patients (14%) have required surgical repair of a recurrent hernia, and a tenth patient has a recurrence that is managed non-surgically, for a total recurrence rate of 15.6% over the entire time frame. Median time to recurrence was 32 months, and a Kaplan–Meier freedom from recurrence curve is depicted. 28 patients have undergone ultrasound or CT assessments of the abdominal wall which demonstrate radiographic fascial integrity 12–70 months after repair. Three patients have been re-explored for unrelated reasons in the years following ventral incisional hernia repair with UBM, and full thickness fascial biopsies demonstrate a robust remodeling response histologically similar to native myofascial tissue. No patients have developed graft infection, fistulization to the graft, or required graft explantation. Carolina Comfort Scale assessment of 45 patients 3 years after the repair averaged 16 out of a possible 115.

Conclusion

In 64 patients undergoing complex ventral incisional hernia repair with UBM reinforcement, all have experienced successful resolution of complex clinical conditions and 15.6% of these repairs have recurred at a median follow-up of 3 years. Three full-thickness biopsies of the repaired fascia years later shed light on a promising remodeling response which may signal strength and durability comparable to native fascia.

"Complex abdominal wall" management: evidence-based guidelines of the Italian Consensus Conference

To date, there is no shared consensus on a definition of a complex abdominal wall in elective surgery and in the emergency, on indications, technical details, complications, and follow-up. The purpose of the conference was to lay the foundations for a homogeneous approach to the complex abdominal wall with the primary intent being to attain the following objectives: (1) to develop evidence-based recommendations to define “complex abdominal wall”; (2) indications in emergency and in elective cases; (3) management of “complex abdominal wall”; (4) techniques for temporary abdominal closure. The decompressive laparostomy should be considered in a case of abdominal compartment syndrome in patients with critical conditions or after the failure of a medical treatment or less invasive methods. In the second one, beyond different mechanism, patients with surgical emergency diseases might reach the same pathophysiological end point of trauma patients where a preventive “open abdomen” might be indicated (a temporary abdominal closure: in the case of a non-infected field, the Wittmann patch and the NPWT had the best outcome followed by meshes; in the case of an infected field, NPWT techniques seem to be the preferred). The second priority is to create optimal both general as local conditions for healing: the right antimicrobial management, feeding—preferably by the enteral route—and managing correctly the open abdomen wall. The use of a mesh appears to be—if and when possible—the gold standard. There is a lot of enthusiasm about biological meshes. But the actual evidence supports their use only in contaminated or potentially contaminated fields but above all, to reduce the higher rate of recurrences, the wall anatomy and function should be restored in the midline, with or without component separation technique. On the other site has not to be neglected that the use of monofilament and macroporous non-absorbable meshes, in extraperitoneal position, in the setting of the complex abdomen with contamination, seems to have a cost effective role too. The idea of this consensus conference was mainly to try to bring order in the so copious, but not always so “evident” literature utilizing and exchanging the expertise of different specialists.

Defining the characteristics of certified hernia centers in Italy: The Italian society of hernia and abdominal wall surgery workgroup consensus on systematic reviews of the best available evidences

BACKGROUND

The terms "Hernia Center" (HC) and Hernia Surgeon" (HS) have gained more and more popularity in recent years. Nevertheless, there is lack of protocols and methods for certification of their activities and results. The Italian Society of Hernia and Abdominal Wall Surgery proposes a method for different levels of certification.

METHODS

The national board created a commission, with the task to define principles and structure of an accreditation program. The discussion of each topic was preceded by a Systematic Review, according to PRISMA Guidelines and Methodology. In case of lack or inadequate data from literature, the parameter was fixed trough a Commission discussion.

RESULTS

The Commission defined a certification process including: "FLC - First level Certification": restricted to single surgeon, it is given under request and proof of a formal completion of the learning curve process for the basic procedures and an adequate year volume of operations. "Second level certification": Referral Center for Abdominal Wall Surgery. It is a public or private structure run by at least two already certified and confirmed FLC surgeons. "Third level certification": High Specialization Center for Abdominal Wall Surgery. It is a public or private structure, already confirmed as Referral Centers, run by at least three surgeons (two certified and confirmed with FLC and one research fellow in abdominal wall surgery). Both levels of certification have to meet the Surgical Requirements and facilities criteria fixed by the Commission.

CONCLUSION

The creation of different types of Hernia Centers is directed to create two different entities offering the same surgical quality with separate mission: the Referral Center being more dedicated to clinical and surgical activity and High Specialization Centers being more directed to scientific tasks.

A New Approach to an Old Technique—The S.U.T.R. First Technique

Ventral and incisional hernias of the abdominal wall are common problems treated by surgeons around the globe. Incisional hernias are common postoperative complications of abdominal laparotomies with a reported incidence of up to 20 per cent. The increasing use of prosthetic mesh in open ventral hernia repairs necessitated the development of different operative techniques used in the repairs. It also required that surgeons become facile with placement of the mesh in different anatomical positions on the abdominal wall. One of the most common locations is placement of the mesh in the underlay position. Many surgeons who use the underlay technique have expressed significant concerns. Among these are fear of an inadvertent bowel injury while placing the mesh, poor visualization during mesh placement, and the inability to use the underlay technique for difficult hernias. We present a very useful, if not, novel technique of open hernia repair using mesh in the underlay position that helps to 1) prevent complications, 2) facilitate easier mesh fixation, 3) simplify open repair of atypical ventral hernias, and 4) reduce total operative time while still adhering to the important fundamental principles of a tension-free hernia repair. This technique as we describe it has been compared with the old parachute technique, but we think this is a significant improvement of that seldom used technique. We believe the use of this technique for the underlay position makes open ventral hernia repair safer, faster, and easier; however, our goal for this article is to describe the procedure in detail. In addition, we recently have started using this technique to fix the mesh when doing the retrorectus approach as well.

What is the evidence for the use of biologic or biosynthetic meshes in abdominal wall reconstruction?

INTRODUCTION

Although many surgeons have adopted the use of biologic and biosynthetic meshes in complex abdominal wall hernia repair, others have questioned the use of these products. Criticism is addressed in several review articles on the poor standard of studies reporting on the use of biologic meshes for different abdominal wall repairs. The aim of this consensus review is to conduct an evidence-based analysis of the efficacy of biologic and biosynthetic meshes in predefined clinical situations.

METHODS

A European working group, "BioMesh Study Group", composed of invited surgeons with a special interest in surgical meshes, formulated key questions, and forwarded them for processing in subgroups. In January 2016, a workshop was held in Berlin where the findings were presented, discussed, and voted on for consensus. Findings were set out in writing by the subgroups followed by consensus being reached. For the review, 114 studies and background analyses were used.

RESULTS

The cumulative data regarding biologic mesh under contaminated conditions do not support the claim that it is better than synthetic mesh. Biologic mesh use should be avoided when bridging is needed. In inguinal hernia repair biologic and biosynthetic meshes do not have a clear advantage over the synthetic meshes. For prevention of incisional or parastomal hernias, there is no evidence to support the use of biologic/biosynthetic meshes. In complex abdominal wall hernia repairs (incarcerated hernia, parastomal hernia, infected mesh, open abdomen, enterocutaneous fistula, and component separation technique), biologic and biosynthetic meshes do not provide a superior alternative to synthetic meshes.

CONCLUSION

The routine use of biologic and biosynthetic meshes cannot be recommended.

Scarring vs. functional healing: Matrix-based strategies to regulate tissue repair

All vertebrates possess mechanisms to restore damaged tissues with outcomes ranging from regeneration to scarring. Unfortunately, the mammalian response to tissue injury most often culminates in scar formation. Accounting for nearly 45% of deaths in the developed world, fibrosis is a process that stands diametrically opposed to functional tissue regeneration. Strategies to improve wound healing outcomes therefore require methods to limit fibrosis. Wound healing is guided by precise spatiotemporal deposition and remodelling of the extracellular matrix (ECM). The ECM, comprising the non-cellular component of tissues, is a signalling depot that is differentially regulated in scarring and regenerative healing. This Review focuses on the importance of the native matrix components during mammalian wound healing alongside a comparison to scar-free healing and then presents an overview of matrix-based strategies that attempt to exploit the role of the ECM to improve wound healing outcomes.

Risk-adjusted adverse outcomes in complex abdominal wall hernia repair with biologic mesh: A case series of 140 patients

INTRODUCTION

Biologic mesh is preferred for repair of complex abdominal wall hernias (CAWHs) in patients at high risk of wound infection. We aimed to identify predictors of adverse outcomes after complex abdominal wall hernia repair (CAWR) using biologic mesh with different placement techniques and under different surgical settings.

METHODS

A retrospective case series study was conducted on all patients who underwent CAWR with biologic mesh between 2010 and 2015 at a tertiary medical center.

RESULTS

the study population included 140 patients with a mean age of 54 ± 14 years and a median follow up period 8.8 months. Mesh size ranged from 50 to 1225 cm². Ninety percent of patients had undergone previous surgery. Type of surgery was classified as elective in 50.7%, urgent in 24.3% and emergent in 25.0% and a porcine mesh was implanted in 82.9%. The most common mesh placement technique was underlay (70.7%), followed by onlay (16.4%) and bridge (12.9%). Complications included wound complications (30.7%), reoperation (25.9%), hernia recurrence (20.7%), and mesh removal (10.0%). Thirty-two patients (23.0%) were admitted to the ICU and the mean hospital length of stay was 10.8 ± 17.5 days. Age-sex adjusted predictors of recurrence were COPD (OR 4.2; 95%CI 1.003-17.867) and urgent surgery (OR 10.5; 95%CI 1.856-59.469), whereas for reoperation, mesh size (OR 6.8; 95%CI 1.344-34.495) and urgent surgery (OR 5.2; 95%CI 1.353-19.723) were the predictors.

CONCLUSIONS

Using biologic mesh, one-quarter and one-fifth of CAWR patients are complicated with reoperation or recurrence, respectively. The operation settings and comorbidity may play a role in these outcomes regardless of the mesh placement techniques.

Synthetic versus Biologic Mesh in Single-Stage Repair of Complex Abdominal Wall Defects in a Contaminated Field

BACKGROUND

Synthetic meshes have been used with varying rates of success in a contaminated setting, although their use is not widely accepted because of concerns for infection. A biologic mesh (BM) is assumed to be more resistant to infection than a synthetic mesh; however, sparse clinical data support this theory. The hypothesis for this study: Uncoated polypropylene synthetic mesh (USM) can be used to obtain a durable repair in the setting of a contaminated abdominal wall reconstruction (AWR) in a single-stage procedure with comparable infectious outcomes to a biologic mesh repair.

PATIENTS AND METHODS

We performed a retrospective chart review on contaminated AWR, comparing 34 BM with 24 USM with infection as the primary outcome of interest. Secondary outcomes were re-admission and re-operation. We also investigated the microbial isolates that were cultured.

RESULTS

Mesh groups were similar in their demographics, duration of surgery, previous mesh, surgical site class, and source of contamination. Length of stay was 4 d longer in BM, p = 0.01. Overall infection rate was 50% for BM vs. 29.2% for USM, p = 0.18. Treatment in case of infection was similar across both groups. Gram positive bacteria comprised 39% of BM microbiology vs. 63% for USM. Re-admission rate was 52.9% for BM versus 45.8% for USM, p > 0.5. The BMs re-admitted for surgical site infection/abdominal abscess were 38.9% versus 55.6% for USM. No USM were re-admitted for seroma versus 33.3% of BM, p = 0.06. Re-operation rate was 26.5% for BM versus 33.3% for USM, p > 0.5. Procedures performed at re-operation were similar between groups. Regression analysis did not demonstrate an association between mesh type and our outcomes.

CONCLUSION

Our results show that synthetic meshes are not inferior to biologic meshes in contaminated AWR. This is important in view of the tremendous cost disparity between these two products and the questionable ability of biologic mesh to offer a durable hernia repair.

Xenograft biologic mesh in parietal and general surgery: Technical assessment and review of clinical effectiveness and safety data

STUDY AIM

To describe the main technical characteristics of biologic prostheses used for parietal reinforcement and to present the state of the art on their risk/benefit ratio.

METHODS

We conducted a technical analysis of manufacturer specifications of the biologic prostheses that are currently available in France accompanied by a literature review by selecting meta-analyses and systematic reviews, randomized controlled trials and publications of health technology rating agencies.

RESULTS

Biological implants for parietal reinforcement are mainly intended for use in a contaminated environment where the use of synthetic prostheses is contra-indicated. We identified fourteen systematic reviews and meta-analyses and one randomized controlled trial. Six ongoing clinical trials were identified as well as two clinical trials that had been interrupted. In the current state of knowledge, there are no high-level evidence data on the therapeutic contribution of biologic prostheses that allow prioritization of the various biologic prostheses according to their characteristics or their different manufacturing processes.

CONCLUSION

Pending the results of current randomized controlled trials to validate the indications and an eventual specific reimbursement, indications for the use of biologic parietal reinforcement prostheses seems to be limited to rare clinical situations and only after collegial discussion.

Reconstruction of the Abdominal Wall in Anatomical Plans. Pre- and Postoperative Keys in Repairing "Cold" Incisional Hernias

BACKGROUND AND AIMS

The clinical results of the vertical "vest-over-pants" Mayo repair were evaluated, and the risk factors for incisional hernia recurrence were studied. The purpose of this study is to point out the importance of reducing pre and post operative risk factors in the incisional hernia repair process in order to achieve a physiologically normal abdominal wall.

METHODS

Twenty patients diagnosed with incisional hernia underwent an abdominal reconstruction procedure using the Mayo (Paletot) technique at Bichat Claude Bernard Hospital between 2005 and 2015. All procedures were performed by a single surgeon and all patients were pre-operatively prepared, identifying all coexisting conditions and treating them accordingly before undergoing surgery.

RESULTS

All patients underwent at least one surgical operation before the hernia repair procedure and a quarter had experienced at least three, prior to this one. Nine patients had a body mass index of >30 kg/m2. Additional risk factors and comorbidities included obesity in 45%, diabetes mellitus in 10%, smoking in 55%, and high blood pressure in 40%. Hernia defect width was from 3 cm (25% F) to 15 cm (5% M) of which nine patients (45%) had a 10 cm defect. Most of the patients had an average hospitalization of 7 days. The patients were carefully monitored and were called on periodic consultations after 3, 6, and 12 months from the moment of the procedure. Patient feedback regarding hernia recurrence and complaints about the scar were noted. Physical examination is essential in determining the hernia recurrence therefore the scar was examined for any abnormalities that may have occurred, which was defined as any palpable or detected fascial defect located within seven centimeters of the hernia repair. Post-operative complications: seroma formation, wound hematoma, superficial and deep wound infection, recurrences and chronic pain were followed and no complications were registered during the follow-up period.

CONCLUSIONS

Reducing the risk factors to a minimum prior to surgery will increase the success of the incisional hernia repair and generate a positive impact on the patient's quality of life. The lofty goal of significant weight loss prior to elective hernia has shown to be the key factor in using the Mayo technique for incisional hernia repair. This study demonstrates that the Mayo repair technique is a suitable and trustworthy alternative for repairing incisional hernias with very good results. It's costs are minimal and it can be easily reproduced, even by less experienced surgeons.

Outcomes following placement of non-cross-linked porcine-derived acellular dermal matrix in complex ventral hernia repair

Repair of complex ventral hernias frequently results in postoperative complications. This study assessed postoperative outcomes in a consecutive cohort of patients with ventral hernias who underwent herniorrhaphy using components separation techniques and reinforcement with non–cross-linked intact porcine-derived acellular dermal matrix (PADM) performed by a single surgeon between 2008 and 2012. Postoperative outcomes of interest included incidence of seroma, wound infection, deep-vein thrombosis, bleeding, and hernia recurrence determined via clinical examination. Of the 47 patients included in the study, 25% were classified as having Ventral Hernia Working Group grade 1 risk, 62% as grade 2, 2% as grade 3, and 11% as grade 4; 49% had undergone previous ventral hernia repair. During a mean follow-up of 31 months, 3 patients experienced hernia recurrence, and 9 experienced other postoperative complications: 4 (9%) experienced deep-vein thrombosis; 3 (6%), seroma; 2 (4%), wound infection; and 2 (4%), bleeding. The use of PADM reinforcement following components separation resulted in low rates of postoperative complications and hernia recurrence in this cohort of patients undergoing ventral hernia repair.

Laparoscopic repair of complicated umbilical hernia with Strattice Laparoscopic™ reconstructive tissue matrix

INTRODUCTION

Complex hernias continue to present a challenge. Surgical techniques for repair are carefully considered to reduce risk for complications. Laparoscopic repairs improve postoperative infection rates, and placement of biologic mesh decreases mesh infection rates. However, laparoscopic repairs using biologic mesh is generally challenging due to difficulty with maneuverability.

PRESENTATION OF CASE

We present a case of a complex ventral hernia that was laparoscopically repaired using a new FDA cleared laparoscopic biologic graft. The patient had multiple comorbidities, including obesity, hepatitis C, endocarditis secondary to IV drug use, tobacco smoking, bilateral inguinal hernia, and recurrent umbilical hernia. The recurrent hernia was larger, irreducible, and discolored compared to original defect. The patient underwent laparoscopic repair with primary closure and reinforcement with Strattice™ Tissue Matrix Laparoscopic (LifeCell Corporation, Branchburg, NJ). At nine months postoperative, the patient had no evidence of recurrence, infection, or chronic pain, demonstrating early success from the surgical management.

DISCUSSION

Presence of multiple comorbidities and incarcerated recurrent hernia increase risk for complications during and/or after hernia repair. Considering these factors, laparoscopic repair with Strattice Laparoscopic and defect closure was a reasonable technique for repair.

CONCLUSION

Laparoscopic suture repair reinforced with biologic dermal tissue matrix was successfully performed during a complex hernia repair.

In vitro and in vivo characterization of a fully resorbable and composite surgical mesh

Fully resorbable and composite synthetic meshes are intended to provide advantages over nonabsorbable synthetic meshes, such as minimization of visceral adhesions and improved biocompatibility, but the inflammatory response to these materials has not previously been fully characterized. We compared resorbable and composite synthetic meshes using in vitro characterization and evaluated the host response in a nonhuman primate acute abdominal wall defect. After a 2-week in vitro incubation, resorbable synthetic mesh mechanical strength decreased to 0.12 ± 0.09 N (0.25% of initial strength), which preceded acidification and a fractured morphology at 1 month. The composite synthetic mesh strength decreased to 10.0 ± 3.2 N (41.1% of initial strength), coincident with morphological changes. In vivo, resorbable synthetic mesh elicited an intense yet transient foreign-body response, with macrophages and myofibroblasts persisting through 3 months of implantation. At 6 months, resorbable synthetic mesh was undetectable and the mesh–host tissue interface strength (14.7 ± 7.9 N) was equivalent to that of primary repair (21.4 ± 4.9 N). The composite synthetic mesh elicited a significant foreign-body response following 1 month of implantation. By 3 months, the composite synthetic mesh resorbable films had fully degraded, with foreign-body reaction localized to polypropylene fibers. By 6 months, macrophages had surrounded these polypropylene fibers, with a myofibroblast-positive capsule encircling a macrophage-rich layer. Resorbable and composite synthetic meshes may ultimately not be the most ideal biomaterials in situations where the biological response is expected to lead to a regeneration of host soft tissues.