Single institutional experience using biological mesh for abdominal wall reconstruction

Acellular dermal matrices in reconstructive surgery; history, current implications and future perspectives for surgeons

Large-scale defects of body in the reconstructive surgical practice, and the helplessness of their repair with autologous tissues, have been an important factor in the development of artificial biological products for the temporary, definitive, or staged repair of these defects. A major advance in the field of plastic and other reconstructive surgery in this regard has been the introduction and successful use of acellular dermal matrices (ADMs). In recent years, not only the type of tissue from which ADMs are produced, product range, diversity and areas of use have increased, but their use in reconstructive fields, especially in post oncologic breast surgery, has become highly regarded and this has favored ADMs to be a potential cornerstone in specific and well-defined surgical fields in future. It is essential that reconstructive surgeons become familiar with some of the ADM’s as well as the advantages and limitations to their use. This review not only provides basic science and clinical evidence of the current use of ADMs in wide range of surgical fields but also targets to keep them as an important backdrop in the armamentarium of reconstructive surgeons. Brief considerations of possible future directions for ADMs are also conducted in the end.

Combined use of composite mesh and acellular dermal matrix graft for abdominal wall repair following tumour resection

BACKGROUND

Surgeries for sarcomas in the abdominal wall require wide resections, often radical en bloc resections, which generate major defects involving a very complex repair. The combined use of porcine dermal xenografts, together with composite meshes, may assist in the repair of these defects with minimal complications.

METHOD

We present a series of 19 patients (10 males and 9 females), with a mean age of 53.2 years (range: 11-86 years) treated in the Sarcoma Unit of the Virgen de la Arrixaca University Hospital from January 2015 to December 2021. Histopathologically, there were four chondrosarcomas (21%), three Ewing sarcomas (15.7%), two desmoid tumours (10.5%), two undifferentiated pleomorphic sarcomas (10.5%), two well-differentiated liposarcomas (10.5%), two leiomyosarcomas (10.5%), one synovial sarcoma, one dermatofibrosarcoma protuberans, one fibromyxoid sarcoma (or Evans tumour), and one metastasis from an adenocarcinoma of unknown origin. All the patients were resected following surgical oncology principles and reconstructed by means of the combined use of a composite mesh acting as a neoperitoneum and a porcine dermal xenograft acting as an abdominal neofascia.

RESULTS

The mean size of the defects generated after surgery for tumour excision was 262.8 cm2 (range: 150-600 cm2). After a mean follow-up of 38 months, six patients (31.5%) developed complications-two cases of wound dehiscence, one case of surgical wound infection, one case of graft partial necrosis, one case of anastomotic leak and one death due to multiorgan failure secondary to massive bronchoaspiration.

CONCLUSION

Surgeries for sarcomas of the abdominal wall require wide oncological resections, which generate major abdominal wall defects. The repair of these defects by means of the combined use of synthetic and biological meshes is a technique associated with minimal complications and excellent medium-term results.

Component Separation Decreases Hernia Recurrence Rates in Abdominal Wall Reconstruction with Biologic Mesh

BACKGROUND

It is not clear whether mesh-reinforced anterior component separation (CS) for abdominal wall reconstruction (AWR) results in better outcomes than mesh-reinforced primary fascial closure (PFC) without CS, particularly when acellular dermal matrix is used. The authors compared outcomes of CS versus PFC repair in AWR procedures aiming to determine whether CS results in better outcomes.

METHODS

This retrospective study of prospectively collected data included 461 patients who underwent AWR with acellular dermal matrix during a 10-year period at an academic cancer center. The primary endpoint was hernia recurrence; the secondary outcome was surgical-site occurrence (SSO).

RESULTS

A total of 322 patients (69.9%) who underwent mesh-reinforced AWR with CS (AWR-CS) and 139 (30.1%) who underwent AWR with PFC (AWR-PFC) without CS were compared. AWR-PFC repairs had a higher hernia recurrence rate than AWR-CS repairs (10.8% versus 5.3%; P = 0.002) but similar overall complication (28.8% versus 31.4%; P = 0.580) and SSO (18.7% versus 25.2%; P = 0.132) rates. CS repairs experienced significantly higher wound separation (17.7% versus 7.9%; P = 0.007), fat necrosis (8.7% versus 2.9%; P = 0.027), and seroma (5.6% versus 1.4%; P = 0.047) rates than PFC repairs. The best cutoff with respect to hernia recurrence was 7.1 cm of abdominal defect width.

CONCLUSION

AWR-CS repair resulted in a lower hernia recurrence rate than AWR-PFC but, despite the additional surgery, had similar SSO rates on long-term follow-up.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Comparison of outcomes of ventral hernia repair using different meshes: a systematic review and network meta-analysis

PURPOSE

We conducted a network meta-analysis to evaluate potential differences in patient outcomes when different meshes, especially biological meshes, were used for ventral hernia repair.

METHODS

PubMed, Embase, Cochrane Library, and Clinical Trials.gov databases were searched for studies comparing biological meshes with biological or synthetic meshes for ventral hernia repair. The outcomes were hernia recurrence rate, surgical site infection, and seroma. We performed a two-step network meta-analysis to investigate the outcomes of several biological meshes: non-cross-linked human acellular dermal matrix (NCHADM), non-cross-linked porcine ADM (NCPADM), non-cross-linked bovine ADM (NCBADM), cross-linked porcine ADM (CPADM), and porcine small intestinal submucosa (PSIS).

RESULTS

From 6304 publications, 23 studies involving 2603 patients were finally included. We found no differences between meshes in recurrence at 1-year follow-up and in surgical site infection rate. NCBADM was associated with the lowest recurrence rate and the lowest surgical site infection rate. NCHADM implantation was associated with the lowest rate of seroma. PSIS was associated with a higher risk of seroma than NCHADM (pooled risk ratio 3.89, 95% confidence interval 1.13-13.39) and NCPADM (RR 3.42, 95% CI 1.29-9.06).

CONCLUSIONS

Our network meta-analysis found no differences in recurrence rate or surgical site infection among different biological meshes. The incidence of postoperative seroma was higher with PSIS than with acellular dermal matrices. We observed large heterogeneity in the studies of ventral hernia repair using biological meshes, and, therefore, well-designed randomized clinical trials are needed.

Incisional hernia repair with a slowly absorbable P4HB mesh: what happens after the mesh disappears? A retrospective longitudinal clinical study

PURPOSE

To analyze the incisional hernia recurrence rate at a long-term follow-up using a biosynthetic long-term absorbable mesh in patients with a higher risk of surgical infection in a contaminated surgical field.

METHODS

This was a retrospective multicentric study. All patients undergoing incisional hernia repair between 2016 and 2018 at 6 participating university centers were included. Patients were classified according to the Ventral Hernia Working Group (VHWG). All consecutive patients who underwent abdominal wall repair using biosynthetic long-term absorbable mesh (Phasix^®) in contaminated fields (grade 3 and 4 of the VHWG classification) were included. Patients were followed-up until September 2021. Preoperative, operative, and postoperative data were collected. All patients' surgical site infections (SSIs) and surgical site occurrences (SSOs) were recorded. The primary outcome of interest was the clinical incisional hernia recurrence rate.

RESULTS

One hundred and eight patients were included: 77 with VHWG grade 3 (71.3%) and 31 with VHWG grade 4 (28.7%). Median time follow-up was 41 months [24; 63]. Twenty-four patients had clinical recurrence during the follow-up (22.2%). The SSI and SSO rates were 24.1% and 36.1%, respectively. On multivariate analysis, risk factors for incisional hernia recurrence were previous recurrence, mesh location, and postoperative enterocutaneous fistula.

CONCLUSIONS

At the 3 year follow-up, the recurrence rate with a biosynthetic absorbable mesh (Phasix^®) for incisional hernia repair in high-risk patients (VHWG grade 3 and 4) seemed to be suitable (22.2%). Most complications occurred in the first year, and SSI and SSO rates were low despite high-risk VHWG grading.

Slowly absorbable mesh in contaminated incisional hernia repair: results of a French multicenter study

PURPOSE

To analyze the postoperative morbidity and 1-year recurrence rate of incisional hernia repair using a biosynthetic long-term absorbable mesh in patients at higher risk of surgical infection in a contaminated surgical field.

METHODS

All patients undergoing incisional hernia repair in a contaminated surgical field with the use of a biosynthetic long-term absorbable mesh (Phasix®) between May 2016 and September 2018 at six participating university centers were included in this retrospective cohort and were followed-up until September 2019. Regarding the risk of surgical infection, patients were classified according to the modified Ventral Hernia Working Group classification. Preoperative, operative and postoperative data were collected. All patients' surgical site infections (SSIs) and occurrences (SSOs) and recurrence rates were the endpoints of the study.

RESULTS

Two hundred and fifteen patients were included: 170 with mVHWG grade 3 (79%) and 45 with mVHWG grade 2 (21%). The SSI and SSO rates at 12 months were 22.3% and 39.5%, respectively. According to the Dindo-Clavien classification, 43 patients (20.0%) had at least one minor complication, and 57 patients (26.5%) had at least one major complication. Among the 121 patients (56.3%) having at least 1 year of follow-up, the clinical recurrence rate was 12.4%. Multivariate analysis showed that a concomitant gastrointestinal procedure was an independent risk factor for surgical infection (OR = 2.61), and an emergency setting was an independent risk factor for major complications (OR = 11.9).

CONCLUSION

The use of a biosynthetic absorbable mesh (Phasix®) is safe in a contaminated surgical field, with satisfying immediate postoperative and 1-year results.

TRIAL REGISTRATION

The study is registered on Clinical Trial ID: NCT04132986.

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.

Invasive Candida albicans fungal infection requiring explantation of a noncrosslinked porcine derived biologic mesh: a rare but catastrophic complication in abdominal wall reconstruction

SUMMARY

Biologic mesh is preferred over synthetic mesh for complex and contaminated abdominal wall repairs; however, there are very little data on the risks and complications associated with its use. We report the case of a 67-year-old man with failed synthetic mesh repair for recurrent ventral hernia, who subsequently required an abdominal wall reconstruction (AWR), including the intraperitoneal sublay of noncrosslinked biologic mesh. His postoperative course was complicated with catastrophic sepsis and sustained hemodynamic instability, responding only to mesh explantation. The biologic mesh was subsequently noted to be histologically infected with invasive Candida albicans. Although noncrosslinked biologic mesh is a valuable adjunct to AWR, it is not infection-resistant. Although it is rare, infection of any foreign tissue, including biologic mesh, can occur in the setting of complex ventral abdominal wall repairs. Clinicians should be watchful for such infections in complex repairs as they may require biologic mesh explantation for clinical recovery.

Non-cross-linked biological mesh in complex abdominal wall hernia: a cohort study

Purpose

Complex abdominal wall hernia repair (CAWHR) is a challenging procedure. Mesh prosthesis is indicated, but the use of synthetic mesh in a contaminated area may add to overall morbidity. Biological meshes may provide a solution, but little is known about long-term results. The aim of our study was to evaluate clinical efficacy and patient satisfaction following Strattice™ (PADM) placement.

Methods

In this cohort study, all patients operated for CAWHR with PADM in three large community hospitals in Germany were included. Patients underwent abdominal examination, an ultrasound was performed, and patients completed quality-of-life questionnaires. The study was registered in ClinicalTrials.gov under Identifier NCT02168231.

Results

Twenty-seven patients were assessed (14 male, age 67.5 years, follow-up 42.4 months). The most frequent postoperative complication was wound infection (39.1%). In no case, the PADM had to be removed. Four patients had passed away. During outpatient clinic visit, six out of 23 patients (26.1%) had a recurrence of hernia, one patient had undergone reoperation. Five patients (21.7%) had bulging of the abdominal wall. Quality-of-life questionnaires revealed that patients judged their scar with a median 3.5 out of 10 points (0 = best) and judged their restrictions during daily activities with a median of 0 out of 10.0 (0 = no restriction).

Conclusions

Despite a high rate of wound infection, no biological mesh had to be removed. In some cases, therefore, the biological meshes provided a safe way out of desperate clinical situations. Both the recurrence rate and the amount of bulging are high (failure rate 47.8%). The reported quality of life is good after repair of these complex hernias.

A retrospective, Italian multicenter study of complex abdominal wall defect repair with a Permacol biological mesh

Complex abdominal wall defects (CAWDs) can be difficult to repair and using a conventional synthetic mesh is often unsuitable. A biological mesh might offer a solution for CAWD repair, but the clinical outcomes are unclear. Here, we evaluated the efficacy of a cross-linked, acellular porcine dermal collagen matrix implant (Permacol) for CAWD repair in a cohort of 60 patients. Here, 58.3% patients presented with a grade 3 hernia (according to the Ventral Hernia Working Group grading system) and a contaminated surgical field. Permacol was implanted as a bridge in 46.7%, as an underlay (intraperitoneal position) in 38.3% and as a sublay (retromuscolar position) in 15% of patients. Fascia closure was achieved in 53.3% of patients. The surgical site occurrence rate was 35% and the defect size significantly influenced the probability of post-operative complications. The long-term (2 year) hernia recurrence rate was 36.2%. This study represents the first large multi-centre Italian case series on Permacol implants in patients with a CAWD. Our data suggest that Permacol is a feasible strategy to repair a CAWD, with acceptable early complications and long-term (2 year) recurrence rates.

Long-term outcomes after contaminated complex abdominal wall reconstruction

PURPOSE

Complex abdominal wall repair (CAWR) in a contaminated operative field is a challenge. Available literature regarding long-term outcomes of CAWR comprises studies that often have small numbers and heterogeneous patient populations. This study aims to assess long-term outcomes of modified-ventral hernia working group (VHWG) grade 3 repairs. Because the relevance of hernia recurrence (HR) as the primary outcome for this patient group is contentious, the need for further hernia surgery (FHS) was also assessed in relation to long-term survival.

METHODS

A retrospective cohort study with a single prospective follow-up time-point nested in a consecutive series of patients undergoing CAWR in two European national intestinal failure centers.

RESULTS

In long-term analysis, 266 modified VHWG grade 3 procedures were included. The overall HR rate was 32.3%. The HR rates for non-crosslinked biologic meshes and synthetic meshes when fascial closure was achieved were 20.3% and 30.6%, respectively. The rates of FHS were 7.2% and 16.7%, and occurred only within the first 3 years. Bridged repairs showed poorer results (fascial closure 22.9% hernia recurrence vs bridged 57.1% recurrence). Overall survival was relatively good with 80% en 70% of the patients still alive after 5 and 10 years, respectively. In total 86.6% of the patients remained free of FHS.

CONCLUSIONS

In this study of contaminated CAWR, non-crosslinked biologic mesh shows better results than synthetic mesh. Bridging repairs with no posterior and/or anterior fascial closure have a higher recurrence rate. The overall survival was good and the majority of patients remained free of additional hernia surgery.

Acellular Dermal Matrices: Applications in Plastic Surgery

Modern advances in tissue engineering have transformed the plastic surgeon's management strategies across a wide variety of applications. Comprehension of the fundamentals of biologic constructs is critical to navigating the available armamentarium. It is essential that plastic surgeons become familiar with some of the existing methods for utilizing biologics as well as the advantages and limitations to their use. In this article, the authors describe the basic science of biologics with a focus on acellular dermal matrices (ADMs), and review the recent evidence behind their use for a variety of reconstructive and aesthetic purposes. The review is organized by system and examines the common indications, techniques, and outcomes pertaining to the application of ADMs in select anatomic areas. The final section briefly considers possible future directions for using biologics in plastic and reconstructive surgery.

Non-Cross-Linked Collagen Mesh Performs Best in a Physiologic, Noncontaminated Rat Model

BACKGROUND

In laparoscopic incisional hernia repair, direct contact between the prosthesis and abdominal viscera is inevitable and may lead to adhesions. Despite the large variety of mesh prosthesis, little is known about their in vivo behavior. Biological meshes are considered to have many advantages, but due to their price they are rarely used. A rat model was used to assess biological and conventional synthetic meshes on their in vivo characteristics.

DESIGN

One-hundred twenty male Wistar rats were randomized into five groups of 24 rats. A mesh was implanted intraperitoneally and fixated with nonresorbable sutures. The following five meshes were implanted: Parietene (polypropylene), Permacol (cross-linked porcine acellular dermal matrix), Strattice (non-cross-linked porcine acellular dermal matrix), XCM Biologic (non-cross-linked porcine acellular dermal matrix), and Omyra Mesh (condensed polytetrafluoroethylene). The rats were sacrificed after 30, 90, or 180 days. Incorporation, shrinkage, adhesions, abscess formation, and histology were assessed for all meshes.

RESULTS

All animals thrived postoperatively. After 180 days, Permacol, Parietene, and Omyra Mesh had a significantly better incorporation than Strattice ( P = .001, P = .019, and P = .037 respectively). After 180 days, Strattice had significantly fewer adhesions on the surface of the mesh than Parietene ( P < .001), Omyra Mesh ( P = .011), and Permacol ( P = .027). After 30 days, Permacol had significantly stronger adhesions than Strattice ( P = .030). However, this difference was not significant anymore after 180 days. After 180 days, there was significantly less shrinkage in Permacol than in Strattice ( P = .001) and Omyra Mesh ( P = .050).

CONCLUSION

Based on incorporation, adhesions, mesh shrinkage, and histologic parameters, Strattice performed best in this experimental rat model.

A systematic methodological review of non-randomised interventional studies of elective ventral hernia repair: clear definitions and a standardised minimum dataset are needed

BACKGROUND

Ventral hernias (VHs) often recur after surgical repair and subsequent attempts at repair are especially challenging. Rigorous research to reduce recurrence is required but such studies must be well-designed and report representative and comprehensive outcomes.

OBJECTIVE

We aimed to assesses methodological quality of non-randomised interventional studies of VH repair by systematic review.

METHODS

We searched the indexed literature for non-randomised studies of interventions for VH repair, January 1995 to December 2017 inclusive. Each prospective study was coupled with a corresponding retrospective study using pre-specified criteria to provide matched, comparable groups. We applied a bespoke methodological tool for hernia trials by combining relevant items from existing published tools. Study introduction and rationale, design, participant inclusion criteria, reported outcomes, and statistical methods were assessed.

RESULTS

Fifty studies (17,608 patients) were identified: 25 prospective and 25 retrospective. Overall, prospective studies scored marginally higher than retrospective studies for methodological quality, median score 17 (IQR: 14-18) versus 15 (IQR 12-18), respectively. For the sub-categories investigated, prospective studies achieved higher median scores for their, 'introduction', 'study design' and 'participants'. Surprisingly, no study stated that a protocol had been written in advance. Only 18 (36%) studies defined a primary outcome, and only 2 studies (4%) described a power calculation. No study referenced a standardised definition for VH recurrence and detection methods for recurrence varied widely. Methodological quality did not improve with publication year or increasing journal impact factor.

CONCLUSION

Currently, non-randomised interventional studies of VH repair are methodologically poor. Clear outcome definitions and a standardised minimum dataset are needed.

Repair of complex abdominal wall hernias with a cross-linked porcine acellular matrix: cross-sectional results of a Dutch cohort study

BACKGROUND

The use of synthetic mesh in potentially contaminated and contaminated incisional hernias may lead to a higher morbidity and mortality. Biological meshes may provide a solution, but since these meshes are rarely used, little is known about long-term results. The aim of this cohort study was to evaluate the long-term clinical efficacy and patient satisfaction following Permacol™ in complex abdominal wall hernia repair (CAWHR) patients in a cross-sectional fashion.

MATERIALS AND METHODS

All patients were operated for CAWHR with Permacol™ in the Netherlands between 2009 and 2012. The design was a multicenter cross-sectional cohort study. The STROCSS statement was followed. Patients were interviewed, underwent abdominal examination, and completed quality-of-life questionnaires. ClinicalTrials.gov Identifier NCT02166112. Research Registry Identifier researchregistry4713.

RESULTS

Seventy-seven patients were seen in the outpatient clinic. Their hernias were classified as potentially contaminated in 25 patients (32.5%) and infected in 52 patients (67.5%). The mean follow-up was 22.2 ± 12.6 months. The most frequent postoperative complication was wound infection (n = 21; 27.3%), meshes had to be removed in five patients (6.5%). By the time of their visit to the outpatient clinic, 22 patients (28.6%) had a recurrence of whom ten (13%) had undergone reoperation. Thirty-nine patients (50.6%) had bulging of the abdominal wall. Quality-of-life questionnaires revealed that patients graded their health status with a mean 6.8 (± 1.8) out of 10 points.

CONCLUSION

Bulging and recurrence are frequently observed in patients treated with Permacol™ for CAWHR. Considering both recurrence and bulging as undesirable outcomes of treatment, a total of 46 patients (59.7%) had an unfavorable outcome. Infection rates were high, but comparable with similar patient cohorts. Quality-of-life questionnaires revealed that patients were satisfied with their general health, but scored significantly lower on most quality-of-life modalities of the Short Form-36 questionnaire.

Performance of biological mesh materials in abdominal wall reconstruction: study protocol for a randomised controlled trial

INTRODUCTION

Abdominal wall hernias are a common source of morbidity and mortality. The use of biological mesh has become an important adjunct in successful abdominal wall reconstruction. There are a variety of biological mesh products available; however, there is limited evidence supporting the use of one type over another. This study aims to compare the performance (eg, the rate of hernia recurrence) of either a crosslinked biological mesh product or a non-crosslinked product in patients undergoing abdominal wall reconstruction.

METHODS AND ANALYSIS

This is a single-centre, dual arm randomised controlled trial. Patients requiring abdominal wall reconstruction will be assessed for eligibility. Eligible patients will then undergo an informed consent process following by randomisation to either (1) crosslinked porcine dermis mesh (Permacol); or (2) non-crosslinked porcine dermis mesh (Strattice). These groups will be compared for the rate of hernia recurrence at 1 and 2 years as well as the rate of postoperative complications (eg, surgical site infections).

ETHICS AND DISSEMINATION

This study has been approved by the institution's research ethics board and registered with clinicaltrials.gov. All eligible participants will provide informed consent prior to randomization. The results of this study may help guide the choice of biologic mesh for this population. The results of this study will be published in peer-reviewed journals as well as national and international conferences.

TRIAL REGISTRATION NUMBER

NCT02703662.

Systematic review of the stage of innovation of biological mesh for complex or contaminated abdominal wall closure

Background

Achieving stable closure of complex or contaminated abdominal wall incisions remains challenging. This study aimed to characterize the stage of innovation for biological mesh devices used during complex abdominal wall reconstruction and to evaluate the quality of current evidence.

Methods

A systematic review was performed of published and ongoing studies between January 2000 and September 2017. Eligible studies were those where a biological mesh was used to support fascial closure, either prophylactically after midline laparotomy, or for reinforcement after repair of incisional hernia with midline incision. The primary outcome measure was the IDEAL framework stage of innovation. The key secondary outcome measure was the GRADE criteria for study quality.

Results

Thirty‐five studies including 2681 patients were included. Four studies considered mesh prophylaxis, 23 considered hernia repair, and eight reported on both. There was one published randomized trial (IDEAL stage 3), none of which was of high quality; the others were non‐randomized studies (IDEAL stage 2a). A detailed description of surgical technique was provided in most studies (27 of 35); however, no study reported outcomes according to the European Hernia Society consensus statement and only two described quality control of surgical technique during the study. From 21 ongoing randomized trials and observational studies, 11 considered repair of incisional hernia and 10 considered prophylaxis (seven in elective settings).

Conclusion

The evidence base for biological mesh is limited, and better reporting and quality control of surgical techniques are needed. Although results of ongoing trials over the next decade will improve the evidence base, further study is required in the emergency and contaminated settings.

Biological Implant for Complex Abdominal Wall Reconstruction: A Single Institution Experience and Review of Literature

AIM

To present our single institution and surgeon's complex abdominal wall reconstructions (CAWR) experience with Permacol™ mesh through a non-randomized study.

PATIENTS AND METHOD

Data of 51 consecutive patients were prospectively collected between 2003 and 2015. Patients had a median of 3 comorbidities (range 0-10) and 68% were Center for Disease Control class II-IV. The mean previous repair was 1.3 (range, 0-12), and 25 (44%) had a mesh in situ. The median defect size was 625 cm².

RESULTS

Among the 56 CAWR procedures, in 16 (29%) bowel resection/anastomosis was performed. The overall post-operative complication rate was 45%, and it was wound-related except from 1 patient dead for myocardial infarction. One was lost at follow-up. Five were re-operated for recurrence with a second Permacol mesh, leading to 14 (26%) overall recurrences at a mean follow-up of 44 months (range, 4-123). In 33 (59%) cases, fascial closure was achieved. The mesh placement was intraperitoneal in 89%, retro-muscular in 9% and supra-fascial in 1% of cases. A multivariate analysis showed that predictor risk for recurrence was more than 3 previous repairs, wound class III-IV, whereas age, type of comorbidities, defect size and fascial closure did not influence the recurrence. Median post-operative performance status was 0 (range; 0-3). A satisfaction questionnaire was obtained in 43 patients, and 86% of them were satisfied with the outcome.

CONCLUSIONS

Biological materials have the potential to reduce morbidity and improve outcome of definitive repair of CAWR.

Single-center ventral hernia repair with porcine dermis collagen implant

INTRODUCTION

This study aims to evaluate the outcomes and utilization of porcine acellular dermal collagen implant (PADCI) during VHR at a large tertiary referral center.

METHODS

Records of 5485 patients who underwent VIHR from June 1995 to August 2014 were retrospectively reviewed to identify patients >18 years of age who had VIHR with PADCI reinforcement. Use of multiple mesh reinforcement products, inguinal hernias, and hiatal hernias were exclusion criteria. The primary outcome was hernia recurrence, and secondary outcomes were early complications and surgical site occurrences (SSOs). Uni- and multivariate analyses assessed risk factors for recurrence after PADCI reinforced VIHR.

RESULTS

There were 361 patients identified (54.5% female, mean age of 56.7 ± 12.5 years, and mean body mass index (BMI) of 33.0 ± 9.9 kg/m²). Hypertension (49.5%), diabetes (24.3%), and coronary artery disease (14.4%) were the most common comorbidities, as was active smoking (20.7%). Most were classified as American Association of Anesthesiologists (ASA) Class 3 (61.7%). Hernias were distributed across all grades of the ventral hernia working group (VHWG) grading system: grade I 93 (25.7%), grade II 51 (14.1%), grade III 113 (31.3%), and grade IV 6 (1.6%). Most VIHR were performed from an open approach (96.1%), and were frequently combined with concomitant surgical procedures (47.9%). Early postoperative complications (first 30 days) were reported in 39.0%, with 71 being SSO. Of the 19.7% of patients with SSO, there were 31 who required procedural intervention. After a mean follow-up of 71.5 ± 20.5 months, hernia recurrence was documented in 34.9% of patients. Age and male gender were predictors of recurrence on multivariate analysis.

CONCLUSION

To the best of our knowledge, this is the largest retrospective single institutional study evaluating PADCI to date. Hernias repaired with PADCI were frequently in patients undergoing concomitant operations. Reinforcement with PADCI may be considered a temporary closure, with a relatively high recurrence rate, especially among patients who are older, male, and undergo multiple explorations in a short perioperative period.

Characteristics of different mesh types for abdominal wall repair in an experimental model of peritonitis

BACKGROUND

The use of synthetic mesh to repair a potentially contaminated incisional hernia may lead to higher failure rates. A biological mesh might be considered, but little is known about long-term results. Both biological and synthetic meshes were investigated in an experimental model of peritonitis to assess their characteristics in vivo.

METHODS

Male Wistar rats were randomized into five groups and peritonitis was induced. A mesh was implanted after 24 h. Five meshes were investigated: Permacol™ (cross-linked collagen), Strattice™ (non-cross-linked collagen), XCM Biologic^® (non-cross-linked collagen), Omyra^® Mesh (condensed polytetrafluoroethylene) and Parietene™ (polypropylene). The rats were killed after either 30, 90 or 180 days. Incorporation and shrinkage of the mesh, adhesion coverage, strength of adhesions and histology were analysed.

RESULTS

Of 135 rats randomized, 18 died from peritonitis. Some 180 days after implantation, both XCM Biologic^® and Permacol™ had significantly better incorporation than Strattice™ (P = 0·003 and P = 0·009 respectively). Strattice™ had significantly fewer adhesions than XCM Biologic^® (P = 0·001) and Permacol™ (P = 0·020). Thirty days after implantation, Permacol™ had significantly stronger adhesions than Strattice™ (P < 0·001). Shrinkage was most prominent in XCM Biologic^® , but no significant difference was found compared with the other meshes. Histological analysis revealed marked differences in foreign body response among all meshes.

CONCLUSION

This experimental study suggested that XCM Biologic^® was superior in terms of incorporation, macroscopic mesh infection, and histological parameters such as collagen deposition and neovascularization. There must be sufficient overlap of mesh during placement, as XCM Biologic^® showed a high rate of shrinkage. Surgical relevance The use of synthetic mesh to repair a potentially contaminated incisional hernia is not supported unequivocally, and may lead to a higher failure rate. A biological mesh might be considered as an alternative. There are few long-term studies, as these meshes are expensive and rarely used. This study evaluated the use of biological mesh in a contaminated environment, and investigated whether there is an ideal mesh. A new non-cross-linked biological mesh (XCM Biologic^® ) was evaluated in this experiment. The new non-cross-linked biological mesh XCM Biologic^® performed best and may be useful in patients with a potentially contaminated incisional hernia.

Closed incision prophylactic negative pressure wound therapy in patients undergoing major complex abdominal wall repair

Purpose

To evaluate if incisional prophylactic negative pressure wound therapy (pNPWT) reduces wound infections and other wound complications in high-risk patients undergoing major complex ventral abdominal wall repair.

Methods

Retrospective before–after comparison nested in a consecutive series of patients undergoing elective major complex abdominal wall repair. Starting January 2014, pNPWT was applied on the closed incisional wound for a minimum of 5 days. To minimize selection bias, we compared two periods of 14 months before and after January 2014. Wound infections according to the Centre for Disease Control Surgical Site Infection classification as well as other wound complications were recorded.

Results

Thirty-two patients were included in the pNPWT group and 34 in the control group. The study group involved clean-contaminated and contaminated operations due to enterocutaneous fistula, enterostomies or infected mesh. Median duration of pNPWT was 5 days (IQR 5–7). Overall wound infection rate was 35%. pNPWT was associated with a significant decrease in postoperative wound infection rate (24 versus 51%; p = 0.029, OR 0.30 (95% CI 0.10–0.90)). Incisional wound infection rates dropped from 48 to 7% (p < 0.01, OR 0.08 (95% CI 0.16–0.39), whereas the number of subcutaneous abscesses was comparable in both groups. Moreover, less interventions were needed in the pNPWT group (p < 0.001).

Conclusions

Closed incision pNPWT seems a promising solution to reduce the incidence of wound infections in complex abdominal wall surgery. Randomized controlled trials are needed to estimate more precisely the value and cost-effectiveness of pNPWT in this high-risk setting.

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.

Long-Term Outcomes after Abdominal Wall Reconstruction with Acellular Dermal Matrix

BACKGROUND

Long-term outcomes data for hernia recurrence rates after abdominal wall reconstruction (AWR) with acellular dermal matrix (ADM) are lacking. The aim of this study was to assess the long-term durability of AWR using ADM.

STUDY DESIGN

We studied patients who underwent AWR with ADM at a single center in 2005 to 2015 with a minimum follow-up of 36 months. Hernia recurrence was the primary end point and surgical site occurrence (SSO) was a secondary end point. The recurrence-free survival curves were estimated by Kaplan-Meier product limit method. Univariate and multivariable Cox proportional hazards regression models and logistic regression models were used to evaluate the associations of risk factors at surgery with subsequent risks for hernia recurrence and SSO, respectively.

RESULTS

A total of 512 patients underwent AWR with ADM. After excluding those with follow-up less than 36 months, 191 patients were included, with a median follow-up of 52.9 months (range 36 to 104 months). Twenty-six of 191 patients had a hernia recurrence documented in the study. The cumulative recurrence rates were 11.5% at 3 years and 14.6% by 5 years. Factors significantly predictive of hernia recurrence developing included bridged repair, wound skin dehiscence, use of human cadaveric ADM, and coronary disease; component separation was protective. In a subset analysis excluding bridged repairs and human cadaveric ADM patients, cumulative hernia recurrence rates were 6.4% by 3 years and 8.3% by 5 years. The crude rate of SSO was 25.1% (48 of 191). Factors significantly predictive of the incidence of SSO included at least 1 comorbidity, BMI ≥30 kg/m², and defect width >15 cm.

CONCLUSIONS

Use of ADM for AWR was associated with 11.5% and 14.6% hernia recurrence rates at 3- and 5-years follow-up, respectively. Avoiding bridged repairs and human cadaveric ADM can improve long-term AWR outcomes using ADM.

Primary fascial closure with biologic mesh reinforcement results in lesser complication and recurrence rates than bridged biologic mesh repair for abdominal wall reconstruction: A propensity score analysis

BACKGROUND

Previous studies suggest that bridged mesh repair for abdominal wall reconstruction may result in worse outcomes than mesh-reinforced, primary fascial closure, particularly when acellular dermal matrix is used. We compared our outcomes of bridged versus reinforced repair using ADM in abdominal wall reconstruction procedures.

METHODS

This retrospective study included 535 consecutive patients at our cancer center who underwent abdominal wall reconstruction either for an incisional hernia or for abdominal wall defects left after excision of malignancies involving the abdominal wall with underlay mesh. A total of 484 (90%) patients underwent mesh-reinforced abdominal wall reconstruction and 51 (10%) underwent bridged repair abdominal wall reconstruction. Acellular dermal matrix was used, respectively, in 98% of bridged and 96% of reinforced repairs. We compared outcomes between these 2 groups using propensity score analysis for risk-adjustment in multivariate analysis and for 1-to-1 matching.

RESULTS

Bridged repairs had a greater hernia recurrence rate (33.3% vs 6.2%, P < .001), a greater overall complication rate (59% vs 30%, P = .001), and worse freedom from hernia recurrence (log-rank P <.001) than reinforced repairs. Bridged repairs also had a greater rate of wound dehiscence (26% vs 14%, P = .034) and mesh exposure (10% vs 1%, P = .003) than mesh-reinforced abdominal wall reconstruction. When the treatment method was adjusted for propensity score in the propensity-score-matched pairs (n = 100), we found that the rates of hernia recurrence (32% vs 6%, P = .002), overall complications (32% vs 6%, P = .002), and freedom from hernia recurrence (68% vs 32%, P = .001) rates were worse after bridged repair. We did not observe differences in wound healing and mesh complications between the 2 groups.

CONCLUSION

In our population of primarily cancer patients at MD Anderson Cancer Center bridged repair for abdominal wall reconstruction is associated with worse outcomes than mesh-reinforced abdominal wall reconstruction. Particularly when employing acellular dermal matrix, reinforced repairs should be used for abdominal wall reconstruction whenever possible.

Retro-rectus repair of complex incisional hernia leads to low recurrence rate

BACKGROUND

To assess the outcome of retro-rectus repair of complex abdominal wall repair (CAWR) in a single institution in relation to the use of biologic and synthetic mesh.

METHOD

A retrospective review was undertaken of complex abdominal wall repairs performed by a single surgical team, assessing the outcome of the retro-rectus repair and factors affecting the outcome.

RESULTS

Between 2007 and 2013, 57 (33 male) patients underwent CAWR retro-rectus repair. The material used was assessed as either synthetic or biologic (cross-linked porcine dermal collagen). The Ventral Hernia Working Group grades were similar between groups of patients having a repair with synthetic and biologic mesh. Median follow-up in the synthetic group was 18 months (1-80.5) and 18.4 months (0.5-70.7) in the biologic group. There was no statistical difference in seroma, wound infection or haematoma rates. No fistulae occurred in either group. Overall recurrence was 3.4% and there was no statistical difference between groups.

CONCLUSION

The retro-rectus repair technique is associated with a low rate of recurrence and is now the technique of choice. The choice of material, biologic or synthetic, in Ventral Hernia Working Group grades 1-3 remains controversial.