Biologic grafts for ventral hernia repair: a systematic review. Am J Surg. 2013;205:220-230. [PMID: 23200988 DOI: 10.1016/j.amjsurg.2012.05.028]

Advances, challenges, and future directions in the clinical translation of ECM biomaterials for regenerative medicine applications

Extracellular Matrix (ECM) scaffolds and biomaterials have been widely used for decades across a variety of diverse clinical applications and have been implanted in millions of patients worldwide. ECM-based biomaterials have been especially successful in soft tissue repair applications but their utility in other clinical applications such as for regeneration of bone or neural tissue is less well understood. The beneficial healing outcome with the use of ECM biomaterials is the result of their biocompatibility, their biophysical properties and their ability to modify cell behavior after injury. As a consequence of successful clinical outcomes, there has been motivation for the development of next-generation formulations of ECM materials ranging from hydrogels, bioinks, powders, to whole organ or tissue scaffolds. The continued development of novel ECM formulations as well as active research interest in these materials ensures a wealth of possibilities for future clinical translation and innovation in regenerative medicine. The clinical translation of next generation formulations ECM scaffolds faces predictable challenges such as manufacturing, manageable regulatory pathways, surgical implantation, and the cost required to address these challenges. The current status of ECM-based biomaterials, including clinical translation, novel formulations and therapies currently under development, and the challenges that limit clinical translation of ECM biomaterials are reviewed herein.

Quality of life measures and cost analysis of biologic versus synthetic mesh for ventral hernia repair: The Preventing Recurrence in Clean and Contaminated Hernias randomized clinical trial

BACKGROUND

Although the most durable method for ventral hernia repairs involves using mesh, whether to use biologic mesh versus synthetic mesh remains controversial. This study aimed to compare synthetic and biologic meshes with respect to patient-reported quality of life scores and costs after ventral hernia repair surgeries.

METHODS

This study is part of the Preventing Recurrence in Clean and Contaminated Hernias (PRICE) pragmatic randomized control trial conducted from March 2014 through October 2018. Patients were randomized 1:1 to undergo ventral hernia repair using either a biologic or synthetic mesh. The coprimary outcomes were 2-year changes in Visual Analog Scale, Activities Assessment Scale, Hernia-Related Quality-of-Life Survey, and Short-Form 36 Health Survey (SF-36) quality-of-life scores from repair. The secondary outcome was the overall cost per patient.

RESULTS

Among the 165 patients included in the study, 82 were randomized to biologic meshes and 83 to synthetic meshes. There were no significant differences in the performance between the 2 mesh types with regard to quality-of-life measures using a mixed model approach. This result was consistent even when performing subgroup analysis based on wound contamination. However, nonparametric tests comparing the differences in quality-of-life measures from preoperative to 24-month postoperative timepoints revealed that the synthetic mesh group showed a greater reduction in disability than biologic mesh for the SF-36 (median [interquartile range] of 20 [5-30] vs 6 [1-20], P = .025). This difference was due to reductions in the physical role limitations (62 [0-100] vs 0 [0-50], P = .018) and the pain (38 [12-50] vs 12 [0-25], P = .012) domains of the SF-36. Overall cost per patient was greater for biologic meshes (mean [95% confidence interval] of $80,420 [$66,485-$94,355] vs $61,036 [$48,946-$73,125], P = .038), regardless of insurance type.

CONCLUSION

In this randomized clinical trial, there were no differences in changes in quality-of-life scores at the 2-year timepoint except for the SF-36, where the synthetic mesh may be associated with less pain and physical role limitations than the biologic mesh. Overall costs per patient were less for synthetic than biologic mesh.

Killing two birds with one stone: A therapeutic copper-loaded bio-patch promoted abdominal wall repair via VEGF pathway

Hernia and life-threatening intestinal obstruction often result from abdominal wall injuries, and the regeneration of abdominal wall defects is limited due to the lack of biocompatible, antibacterial and angiogenic scaffolding materials for treating injured tissues. Taking inspiration from the facile preparation of dopamine polymerization and its surface modification technology, in this study, multi-therapeutic copper element was introduced into porcine small intestinal submucosa (SIS) bio-patches through polydopamine (PDA) deposition, in order to regenerate abdominal wall injury. In both in vitro antibacterial assays, cytocompatibility assays and in vivo abdominal wall repair experiments, the SIS/PDA/Cu bio-patches exhibited robust antibacterial efficiency (＞99%), excellent biocompatibility to cells (＞90%), and enhanced neovascularization and improved collagen maturity compared to other commercially available patches (3.0-fold higher than the PP mesh), due to their activation of VEGF pathway. These findings indicated the bio-patch was a promising application for preventing visceral adhesion, bacterial infection, and promoting soft tissue regeneration.

Synthetic Versus Biological Mesh in Ventral Hernia Repair and Abdominal Wall Reconstruction: A Systematic Review and Recommendations from Evidence-Based Medicine

AIM

To compare the efficacy and safety of synthetic and biological meshes in ventral hernia repair (VHR) and abdominal wall reconstruction (AWR).

METHODS

We screened all clinical trials that reported the application of synthetic and biological meshes in VHR and AWR using Medline, Web of Science, and Embase (Ovid). Only comparative studies with similar baselines such as age, sex, body mass index, degree of wound contamination, and hernia defects between the intervention and control groups were included. Effect sizes with 95% confidence were pooled using a random- or fixed-effects model based on the size of heterogeneity. A sensitivity analysis was performed to test the stability of the results.

RESULTS

Ten studies with 1305 participants were included. Biological meshes were associated with significantly higher recurrence rate (OR, 2.09; 95% CI 1.42-3.08; I2 = 50%), surgical site infection (OR, 1.47; 95% CI 1.10-1.97; I2 = 30%), higher re-admission rate (OR, 1.51; 95% CI 1.05-2.17; I2 = 50%), and longer length of hospital stay (SMD, 0.37; 95% CI 0.10-0.65; I2 = 72%). Similar surgical site occurrence, re-operation rate, and mesh explantation rate were observed among biological and synthetic meshes. Biological meshes have no difference in recurrence rate as compared to synthetic meshes, between the clean-contaminated, and contamination-infected fields (OR, 1.41; 95% CI 0.41-4.87 vs 3.00; 95% CI 1.07-8.46; P = 0.36).

CONCLUSION

Synthetic meshes are a safe alternative to biological meshes for VHR and AWR. Considering the high cost of biological meshes, synthetic meshes are more appropriate for the VHR and AWR.

Abdominal wall hernia repair: from prosthetic meshes to smart materials

Hernia reconstruction is one of the most frequently practiced surgical procedures worldwide. Plastic surgery plays a pivotal role in reestablishing desired abdominal wall structure and function without the drawbacks traditionally associated with general surgery as excessive tension, postoperative pain, poor repair outcomes, and frequent recurrence. Surgical meshes have been the preferential choice for abdominal wall hernia repair to achieve the physical integrity and equivalent components of musculofascial layers. Despite the relevant progress in recent years, there are still unsolved challenges in surgical mesh design and complication settlement. This review provides a systemic summary of the hernia surgical mesh development deeply related to abdominal wall hernia pathology and classification. Commercial meshes, the first-generation prosthetic materials, and the most commonly used repair materials in the clinic are described in detail, addressing constrain side effects and rational strategies to establish characteristics of ideal hernia repair meshes. The engineered prosthetics are defined as a transit to the biomimetic smart hernia repair scaffolds with specific advantages and disadvantages, including hydrogel scaffolds, electrospinning membranes, and three-dimensional patches. Lastly, this review critically outlines the future research direction for successful hernia repair solutions by combing state-of-the-art techniques and materials.

Prosthetic meshes for hernia repair: State of art, classification, biomaterials, antimicrobial approaches, and fabrication methods

Worldwide, hernia repair represents one of the most frequent surgical procedures encompassing a global market valued at several billion dollars. This type of surgery usually requires the implantation of a mesh that needs the appropriate chemical, physical and biological properties for the type of repair. This review thus presents a description of the types of hernias, current hernia repair methods, and the state of the art of prosthetic meshes for hernia repair providing the most important meshes used in clinical practice by surgeons working in this area classified according to their biological or chemical nature, morphology and whether bioabsorbable or not. We emphasise the importance of surgical site infection in herniatology, how to deal with this microbial problem, and we go further into the future research lines on the production of advanced antimicrobial meshes to improve hernia repair and prevent microbial infections, including multidrug-resistant strains. A great deal of progress has been made in this biomedical field in the last decade. However, we are still far from an ideal antimicrobial mesh that can also provide excellent integration to the abdominal wall, mechanical performance, low visceral adhesion and minimal inflammatory or foreign body reactions, among many other problems.

Decellularized xenografts in regenerative medicine: From processing to clinical application

Decellularized xenografts are an inherent component of regenerative medicine. Their preserved structure, mechanical integrity and biofunctional composition have well established them in reparative medicine for a diverse range of clinical indications. Nonetheless, their performance is highly influenced by their source (ie species, age, tissue) and processing (ie decellularization, crosslinking, sterilization and preservation), which govern their final characteristics and determine their success or failure for a specific clinical target. In this review, we provide an overview of the different sources and processing methods used in decellularized xenografts fabrication and discuss their effect on the clinical performance of commercially available decellularized xenografts.

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.

Outcomes of a new slowly resorbable biosynthetic mesh (Phasix™) in potentially contaminated incisional hernias: A prospective, multi-center, single-arm trial

BACKGROUND

Resorbable biomaterials have been developed to reduce the amount of foreign material remaining in the body after hernia repair over the long-term. However, on the short-term, these resorbable materials should render acceptable results with regard to complications, infections, and reoperations to be considered for repair. Additionally, the rate of resorption should not be any faster than collagen deposition and maturation; leading to early hernia recurrence. Therefore, the objective of this study was to collect data on the short-term performance of a new resorbable biosynthetic mesh (Phasix™) in patients requiring Ventral Hernia Working Group (VHWG) Grade 3 midline incisional hernia repair.

MATERIALS AND METHODS

A prospective, multi-center, single-arm trial was conducted at surgical departments in 15 hospitals across Europe. Patients aged ≥18, scheduled to undergo elective Ventral Hernia Working Group Grade 3 hernia repair of a hernia larger than 10 cm² were included. Hernia repair was performed with Phasix™ Mesh in sublay position when achievable. The primary outcome was the rate of surgical site occurrence (SSO), including infections, that required intervention until 3 months after repair.

RESULTS

In total, 84 patients were treated with Phasix™ Mesh. Twenty-two patients (26.2%) developed 32 surgical site occurrences. These included 11 surgical site infections, 9 wound dehiscences, 7 seromas, 2 hematomas, 2 skin necroses, and 1 fistula. No significant differences in surgical site occurrence development were found between groups repaired with or without component separation technique, and between clean-contaminated or contaminated wound sites. At three months, there were no hernia recurrences.

CONCLUSION

Phasix™ Mesh demonstrated acceptable postoperative surgical site occurrence rates in patients with a Ventral Hernia Working Group Grade 3 hernia. Longer follow-up is needed to evaluate the recurrence rate and the effects on quality of life. This study is ongoing through 24 months of follow-up.

The Few Who Made It: Commercially and Clinically Successful Innovative Bone Grafts

Bone reconstruction techniques are mainly based on the use of tissue grafts and artificial scaffolds. The former presents well-known limitations, such as restricted graft availability and donor site morbidity, while the latter commonly results in poor graft integration and fixation in the bone, which leads to the unbalanced distribution of loads, impaired bone formation, increased pain perception, and risk of fracture, ultimately leading to recurrent surgeries. In the past decade, research efforts have been focused on the development of innovative bone substitutes that not only provide immediate mechanical support, but also ensure appropriate graft anchoring by, for example, promoting de novo bone tissue formation. From the countless studies that aimed in this direction, only few have made the big jump from the benchtop to the bedside, whilst most have perished along the challenging path of clinical translation. Herein, we describe some clinically successful cases of bone device development, including biological glues, stem cell-seeded scaffolds, and gene-functionalized bone substitutes. We also discuss the ventures that these technologies went through, the hindrances they faced and the common grounds among them, which might have been key for their success. The ultimate objective of this perspective article is to highlight the important aspects of the clinical translation of an innovative idea in the field of bone grafting, with the aim of commercially and clinically informing new research approaches in the sector.

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.

Fasciocutaneous anterolateral thigh flaps for complex abdominal wall reconstruction after resection of enterocutaneous fistulas and the role of indocyanine green angiography: a pilot study

Purpose

No previous study reported the use of a fasciocutaneous anterolateral thigh (ALT) flap combined with a biological mesh for abdominal wall reconstruction (AWR) after enterocutaneous fistula (ECF) in a single-staged procedure and the use of Indocyanine Green Angiography (ICGA) intraoperatively. The purpose of this study was to determine the feasibility and safety of this procedure and to examine the added value of ICGA in minimizing postoperative complications.

Methods

A single-institution review of a prospectively maintained database was conducted at Maastricht University Medical Center. To evaluate the feasibility and safety of this procedure, early (≤ 30 days) and late (> 30 days) postoperative complications were assessed. ECF recurrence was considered the primary outcome. To examine the added value of ICGA, complications in the ICGA group and the non-ICGA group were compared descriptively.

Results

Ten consecutive patients, with a mean age of 66.7 years, underwent a single-staged AWR with fasciocutaneous ALT flaps. Mean follow-up was 17.4 months (4.3–28.2). Two early ECF recurrences were observed. Both restored without the need for reoperation. A lower rate of early complications was observed in the ICGA group compared to the non-ICGA group.

Conclusion

The combination of a biological mesh and fasciocutaneous ALT flap is feasible and safe in AWR after ECF repair in a single-staged approach, with an acceptable complication rate in a cohort of complex patients operated in a dedicated center. ECF closure was achieved in all patients. ICGA seems to be of great added value in minimizing postoperative complications during AWR.

Electronic supplementary material

The online version of this article (10.1007/s10029-020-02167-w) contains supplementary material, which is available to authorized users.

Complex abdominal wall hernia repair with biologic mesh in elderly: a propensity matched analysis

Background

Complex abdominal wall reconstruction (CAWR) has become a common surgical procedure both in non-elderly and elderly patients.

Objective

The aim of this study is to analyze the outcomes of the elderly compared to nonelderly undergoing CAWR using propensity score matching.

Methods

All patients who underwent CAWR using porcine-derived, non-crosslinked acellular dermal matrix (ADM) (Strattice™) between January 2014 and July 2017 were studied retrospectively. Propensity matched analysis was performed for risk adjustment in multivariable analysis and for one-to-one matching. The outcomes were analyzed for differences in postoperative complications, reoperations, mortality, hospital length of stay and adverse discharge disposition.

Results

One hundred-thirty-six patients were identified during the study period. Non-elderly (aged 18–64 years) constituted 70% (n = 95) and elderly (aged ≥ 65 years) comprised 30% of the overall patient population (n = 41). Seventy-three (56.7%) were females. After adjustment through the propensity score, which included 35 pairs, the surgical site infection (p = 1.000), wound necrosis (p = 1.000), the need for mechanical ventilation (p = 0.259), mortality (p = 0.083), reoperation rate (p = 0.141), hospital length of stay (p = 0.206), and discharge disposition (p = 0.795) were similar.

Conclusion

Elderly patients undergoing CAWR with biological mesh have comparable outcomes with non-elderly patients when using propensity matching score.

International classification of abdominal wall planes (ICAP) to describe mesh insertion for ventral hernia repair

BACKGROUND

Nomenclature for mesh insertion during ventral hernia repair is inconsistent and confusing. Several terms, including 'inlay', 'sublay' and 'underlay', can refer to the same anatomical planes in the indexed literature. This frustrates comparisons of surgical practice and may invalidate meta-analyses comparing surgical outcomes. The aim of this study was to establish an international classification of abdominal wall planes.

METHODS

A Delphi study was conducted involving 20 internationally recognized abdominal wall surgeons. Different terms describing anterior abdominal wall planes were identified via literature review and expert consensus. The initial list comprised 59 possible terms. Panellists completed a questionnaire that suggested a list of options for individual abdominal wall planes. Consensus on a term was predefined as occurring if selected by at least 80 per cent of panellists. Terms scoring less than 20 per cent were removed.

RESULTS

Voting started August 2018 and was completed by January 2019. In round 1, 43 terms (73 per cent) were selected by less than 20 per cent of panellists and 37 new terms were suggested, leaving 53 terms for round 2. Four planes reached consensus in round 2, with the terms 'onlay', 'inlay', 'preperitoneal' and 'intraperitoneal'. Thirty-five terms (66 per cent) were selected by less than 20 per cent of panellists and were removed. After round 3, consensus was achieved for 'anterectus', 'interoblique', 'retro-oblique' and 'retromuscular'. Default consensus was achieved for the 'retrorectus' and 'transversalis fascial' planes.

CONCLUSION

Consensus concerning abdominal wall planes was agreed by 20 internationally recognized surgeons. Adoption should improve communication and comparison among surgeons and research studies.

Medical Applications of Collagen and Collagen-Based Materials

Collagen and collagen-based materials have been successfully used in medicine for over 50 years. The number of scientific articles about the role of collagen in the construction of scaffolds for tissue engineering has risen precipitously in recent years. The review contains materials about historic and modern applications of collagen in medicine such as soluble collagen injections, solid constructs reconstructed from solution, and decellularized collagen matrices. The analysis of published data proves the efficacy of collagen material in the treatment of chronic wounds, burns, venous and diabetic ulcers, in plastic, reconstructive and general surgery, urology, proctology, gynecology, ophthalmology, otolaryngology, neurosurgery, dentistry, cardiovascular and bone and cartilage surgery, as well as in cosmetology. Further development of collagenoplasty requires addressing the problems of allergic complications, improvement of structure and maximizing therapeutic effects against pathological processes.

Pre-operative CT scan measurements for predicting complications in patients undergoing complex ventral hernia repair using the component separation technique

Background

The component separation technique (CST) is considered an excellent technique for complex ventral hernia repair. However, postoperative infectious complications and reherniation rates are significant. Risk factor analysis for postoperative complication and reherniation has focused mostly on patient history and co-morbidity and shows equivocal results. The use of abdominal morphometrics derived from CT scans to assist in risk assessment seems promising. The aim of this study is to determine the predictability of reherniation and surgical site infections (SSI) using pre-operative CT measurements.

Methods

Electronic patient records were searched for patients who underwent CST between 2000 and 2013 and had a pre-operative CT scan available. Visceral fat volume (VFV), subcutaneous fat volume (SFV), loss of domain (LOD), rectus thickness and width (RT, RW), abdominal volume, hernia sac volume, total fat volume (TFV), sagittal distance (SD) and waist circumference (WC) were measured or calculated. Relevant variables were entered in multivariate regression analysis to determine their effect on reherniation and SSI as separate outcomes.

Results

Sixty-five patients were included. VFV (p = 0.025, OR = 1.65) was a significant predictor regarding reherniation. Hernia sac volume (p = 0.020, OR = 2.10) and SFV per 1000 cm³ (p = 0.034, OR = 0.26) were significant predictors of SSI.

Conclusion

Visceral fat volume, subcutaneous fat volume and hernia sac volume derived from CT scan measurements may be used to predict reherniation and SSI in patients undergoing complex ventral hernia repair using CST. These findings may aid in optimizing patient-tailored preoperative risk assessment.

Biomaterial Implants in Abdominal Wall Hernia Repair: A Review on the Importance of the Peritoneal Interface

Biomaterials have long been used to repair defects in the clinical setting, which has led to the development of a wide variety of new materials tailored to specific therapeutic purposes. The efficiency in the repair of the defect and the safety of the different materials employed are determined not only by the nature and structure of their components, but also by the anatomical site where they will be located. Biomaterial implantation into the abdominal cavity in the form of a surgical mesh, such as in the case of abdominal hernia repair, involves the contact between the foreign material and the peritoneum. This review summarizes the different biomaterials currently available in hernia mesh repair and provides insights into a series of peculiarities that must be addressed when designing the optimal mesh to be used in this interface.

A post-market, prospective, multi-center, single-arm clinical investigation of Phasix™ mesh for VHWG grade 3 midline incisional hernia repair: a research protocol

Background

Incisional heia is a frequent complication of midline laparotomy. The use of mesh in hernia repair has been reported to lead to fewer recurrences compared to primary repair. However, in Ventral Hernia Working Group (VHWG) Grade 3 hernia patients, whose hernia is potentially contaminated, synthetic mesh is prone to infection. There is a strong preference for resorbable biological mesh in contaminated fields, since it is more able to resist infection, and because it is fully resorbed, the chance of a foreign body reaction is reduced. However, when not crosslinked, biological resorbable mesh products tend to degrade too quickly to facilitate native cellular ingrowth. Phasix™ Mesh is a biosynthetic mesh with both the biocompatibility and resorbability of a biological mesh and the mechanical strength of a synthetic mesh. This multi-center single-arm study aims to collect data on safety and performance of Phasix™ Mesh in Grade 3 hernia patients.

Methods

A total of 85 VHWG Grade 3 hernia patients will be treated with Phasix™ Mesh in 15 sites across Europe. The primary outcome is Surgical Site Occurrence (SSO) including hematoma, seroma, infection, dehiscence and fistula formation (requiring intervention) through 3 months. Secondary outcomes include recurrence, infection and quality of life related outcomes after 24 months. Follow-up visits will be at drain removal (if drains were not placed, then on discharge or staple removal instead) and in the 1st, 3rd, 6th, 12th, 18th and 24th month after surgery.

Conclusion

Based on evidence from this clinical study Depending on the results this clinical study will yield, Phasix™ Mesh may become a preferred treatment option in VHWG Grade 3 patients.

Trial registration

The trial was registered on March 25, 2016 on clinicaltrials.gov: NCT02720042.

Abdominal Compartment Syndrome as a Multidisciplinary Challenge. A Literature Review

Abdominal Compartment Syndrome (ACS), despite recent advances in medical and surgical care, is a significant cause of mortality. The purpose of this review is to present the main diagnostic and therapeutic aspects from the anesthetical and surgical points of view. Intra-abdominal hypertension may be diagnosed by measuring intra-abdominal pressure and indirectly by imaging and radiological means. Early detection of ACS is a key element in the ACS therapy. Without treatment, more than 90% of cases lead to death and according with the last reports, despite all treatment measures, the mortality rate is reported as being between 25 and 75%. There are conflicting reports as to the importance of a conservative therapy approach, although such an approach is the central to treatment guidelines of the World Society of Abdominal Compartment Syndrome, Decompressive laparotomy, although a backup solution in ACS therapy, reduces mortality by 16-37%. The open abdomen management has several variants, but negative pressure wound therapy represents the gold standard of surgical treatment.

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.

Nomenclature in Abdominal Wall Hernias: Is It Time for Consensus?

Abdominal wall reconstruction is a rapidly evolving area of surgical interest. Due to the increase in prevalence and size of ventral hernias and the high recurrence rates, the academic community has become motivated to find the best reconstruction techniques. Whilst interrogating the abdominal wall reconstruction literature, we discovered an inconsistency in hernia nomenclature that must be addressed. The terms used to describe the anatomical planes of mesh implantation ‘inlay’, ‘sublay’ and ‘underlay’ are misinterpreted throughout. We describe the misinterpretation of these terms and give evidence of where it exists in the literature. We give three critical arguments of why these misinterpretations hinder advances in abdominal wall reconstruction research. The correct definitions of the anatomical planes, and their respective terms, are described and illustrated. Clearly defined nomenclature is required as academic surgeons strive to improve abdominal wall reconstruction outcomes and lower complication rates.

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.

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.

Intraluminal mesh migration causing enteroenteric and enterocutaneous fistula: a case and discussion of the 'mesh problem'

The use of synthetic mesh in the abdominal compartment has recently become a topic of debate as high profile public cases have called into question their safety. Several case reports have demonstrated significant complications due to intra-abdominal mesh. Furthermore, some studies have suggested that the rates of these severe complications are underestimated. We present the case of a patient who developed an enteroenteric and enterocutaenous fistulae, an abdominal wall collection and an intraperitoneal inflammatory mass from intraluminal migration of a synthetic mesh inserted during laparoscopic incisional hernia repair. We discuss the considerations and complications of using synthetic mesh for ventral hernia repair and discuss the scientific evidence behind the increasingly apparent 'mesh problem'.

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.

Major Complex Abdominal Wall Repair in Contaminated Fields with Use of a Non-cross-linked Biologic Mesh: A Dual-Institutional Experience

Background

Data on the use of biologic mesh in abdominal wall repair in complex cases remain sparse. Aim of this study was to evaluate a non-cross-linked porcine acellular dermal matrix for repair of complex contaminated abdominal wall defects.

Methods

Retrospective observational cohort study of consecutive patients undergoing abdominal wall repair with use of Strattice™ Reconstructive Tissue Matrix (LifeCell Corporation, Oxford, UK) between January 2011 and February 2015 at two National Intestinal Failure Units.

Results

Eighty patients were identified. Indications for abdominal wall repair included enterocutaneous fistula takedown (n = 50), infected synthetic mesh removal (n = 9), restoration of continuity or creation of a stoma with concomitant ventral hernia repair (n = 12), and others (n = 9). The median defect area was 143.0 cm² (interquartile range or IQR 70.0–256.0 cm²). All had a grade III or IV hernia. Component separation technique (CST) was performed in 54 patients (68%). Complete fascial closure was not possible despite CST and biologic mesh-assisted traction (bridged repair) in 20 patients (25%). In-hospital mortality was 1%. Thirty-six patients (45%) developed a wound infection. None required mesh removal. Of 76 patients with a median clinical follow-up of 7 months (IQR 4–15) available for analysis, 10 patients (13%) developed a hernia recurrence, of whom 3 had undergone bridged repairs. Seven patients developed a postoperative (recurrent) fistula (9%).

Conclusion

Repair of challenging and contaminated abdominal wall defects can be done effectively with non-cross-linked biologic mesh and component separation technique without the need for mesh removal despite wound infections.

Comparison of biological and alloplastic meshes in ventral incisional hernia repair

PURPOSE

The aim of our retrospective analysis was to compare the results of incisional hernia repair by porcine small intestinal submucosa-derived (SIS) meshes with those obtained by alloplastic polypropylene-based (PP) meshes in comparable surgical indications by matched-pair design. We hypothesized that in incisional hernia, SIS mesh repair is associated with fewer recurrences and SSO than PP mesh repair in incisional hernias.

METHODS

Twenty-four matched pairs (SIS vs. PP mesh repair between 1 January 2005 and 31 December 2013) were identified by matching criteria: gender, age, comorbidities, body mass index, EHS hernia classification, mesh implantation technique, CDC wound classification, and source of contamination/primary surgery leading to incisional hernia. Minimal follow-up time was 24 months. Means and standard deviations were compared by paired t test; categorial data were compared by McNemar's test. Poisson's distribution and negative binominal distribution were employed to detect significant correlation.

RESULTS

There were no statistically significant differences between both groups in the pre- and perioperative factors and the follow-up times. There were significantly more wound complications (19 vs. 12, p = 0.041), longer hospital stay (22.0 ± 6.3 vs. 12.0 ± 3.1 days, p = 0.010), and significantly more recurrent hernias (25 vs. 12.5%, p = 0.004) after SIS mesh repair. Both the Poisson's distribution and the negative binominal distribution unveiled significantly more complication points (3-6 vs. 1-2) per month after SIS mesh repair.

CONCLUSION

There is no advantage of SIS meshes compared to PP meshes in incisional hernia repair with different degrees of wound contamination in this matched-pair analysis. Further prospective and randomized trials or at least registry studies such as the EHS register with standardized and defined conditions are warranted.

Evaluation of a Novel Hybrid Viable Bioprosthetic Mesh in a Model of Mesh Infection

Background:

The reported incidence of mesh infection in contaminated operative fields is as high as 30% regardless of material used. Our laboratory previously showed that augmenting acellular bioprosthetic mesh with allogeneic mesenchymal stem cells (MSC) enhances resistance to bacterial colonization in vivo and preserves mesh integrity. This study’s aim was to determine whether augmentation of non-crosslinked porcine dermis (Strattice) with commercially available, cryopreserved, viable MSC-containing human placental tissue (Stravix) similarly improves infection resistance after inoculation with Escherichia coli (E. coli) using an established mesh infection model.

Methods:

Stravix was thawed per manufacturer’s instructions and 2 samples were tested for cell viability using a Live/Dead Cell assay at the time of surgery. Rats (N = 20) were implanted subcutaneously with 1 piece of Strattice and 1 piece of hybrid mesh (Strattice + Stravix sutured at the corners). Rats were inoculated with either sterile saline or 10⁶ colony-forming units of E. coli before wound closure (n = 10 per group). At 4 weeks, explants underwent microbiologic and histologic analyses.

Results:

In E. coli–inoculated animals, severe or complete mesh degradation concurrent with abscess formation was observed in 100% (10/10) hybrid meshes and 90% (9/10) Strattice meshes. Histologic evaluation determined that meshes inoculated with E. coli exhibited severe acute inflammation, which correlated with bacterial recovery (P < 0.001). Viability assays performed at the time of surgery failed to verify the presence of numerous live cells in Stravix.

Conclusions:

Stravix cryopreserved MSC-containing human umbilical tissue does not improve infection resistance of a bioprosthetic mesh in vivo in rats after inoculation with E. coli.

Improvement of mesh recolonization in abdominal wall reconstruction with adipose vs. bone marrow mesenchymal stem cells in a rodent model

BACKGROUND

Reconstruction of muscle defects remains a challenge. Our work assessed the potential of an engineered construct made of a human acellular collagen matrix (HACM) seeded with porcine mesenchymal stem cells (MSCs) to reconstruct abdominal wall muscle defects in a rodent model.

METHODS

This study compared 2 sources of MSCs (bone-marrow, BMSCs, and adipose, ASCs) in vitro and in vivo for parietal defect reconstruction. Cellular viability and growth factor release (VEGF, FGF-Beta, HGF, IGF-1, TGF-Beta) were investigated under normoxic/hypoxic culture conditions. Processed and recellularized HACMs were mechanically assessed. The construct was tested in vivo in full thickness abdominal wall defect treated with HACM alone vs. HACM+ASCs or BMSCs (n=14). Tissue remodeling was studied at day 30 for neo-angiogenesis and muscular reconstruction.

RESULTS

A significantly lower secretion of IGF was observed with ASCs vs. BMSCs under hypoxic conditions (-97.6%, p<0.005) whereas significantly higher VEGF/FGF secretions were found with ASCs (+92%, p<0.001 and +72%, p<0.05, respectively). Processing and recellularization did not impair the mechanical properties of the HACM. In vivo, angiogenesis and muscle healing were significantly improved by the HACM+ASCs in comparison to BMSCs (p<0.05) at day 30.

CONCLUSION

A composite graft made of an HACM seeded with ASCs can improve muscle repair by specific growth factor release in hypoxic conditions and by in vivo remodeling (neo-angiogenesis/graft integration) while maintaining mechanical properties.

Temporary abdominal closure for trauma and intra-abdominal sepsis: Different patients, different outcomes

BACKGROUND

Temporary abdominal closure (TAC) after damage control surgery (DCS) for injured patients has been generalized to septic patients. However, direct comparisons between these populations are lacking. We hypothesized that patients with intra-abdominal sepsis would have different resuscitation requirements and lower primary fascial closure rates than trauma patients.

STUDY DESIGN

We performed a 3-year retrospective cohort analysis of patients managed with TAC for trauma (n = 77) or intra-abdominal sepsis (n = 147). All patients received negative pressure wound therapy (NPWT) TAC with intention for planned relaparotomy and sequential abdominal closure attempts at 24- to 48-hour intervals.

RESULTS

At presentation, trauma patients had higher rates of hypothermia (31% vs. 18%), severe acidosis (27% vs. 14%), and coagulopathy (68% vs. 48%), and septic patients had higher vasopressor infusion rates (46% vs. 27%). Forty-eight hours after presentation, septic patients had persistently higher vasopressor infusion rates (37% vs. 17%), and trauma patients had received more red blood cell transfusions (6.0 U vs. 0.0 U), fresh frozen plasma (5.0 U vs. 0.0 U), and crystalloid (8,290 vs. 7,159 ml). Among patients surviving to discharge, trauma patients had higher primary fascial closure (PFC) rates (90% vs. 76%). For trauma patients, independent predictors of failure to achieve PCF were ≥2.5 L NPWT output at 48 hours, ≥10 L crystalloid administration at 48 hours, and ≥10 U PRBC + FFP at 48 hours. For septic patients, relaparotomy within 48 hours predicted successful PFC; requirement for ≥3 diagnostic/therapeutic laparotomies predicted failure to achieve PFC.

CONCLUSIONS

Traumatic injury and intra-abdominal sepsis are associated with distinct pathophysiologic insults, resuscitation requirements, and outcomes. Failure to achieve primary fascial closure in trauma patients was attributable to the triad of hypothermia, acidosis, and coagulopathy; failure to achieve fascial closure in septic patients was dependent upon operative course. Indications and optimal techniques for TAC may differ between these populations.

LEVEL OF EVIDENCE

Therapeutic study, level IV; prognostic study, level III.

Non-crosslinked porcine acellular dermal matrix in pediatric abdominal wall reconstruction: a case series

INTRODUCTION

The use of biologic mesh where native tissue deficiencies limit reconstructive options has been well documented in the adult population, with increasing use to address the special requirements of complex abdominal wall reconstruction. There is, however, little documented evidence as to the safety and efficacy of these products in the pediatric population.

METHODS

This retrospective case series details 5 pediatric cases of complicated abdominal hernia repair with Strattice®, a non-crosslinked porcine acellular dermal matrix. Outcomes measured include recurrence, infection, seroma formation, symptomatic bulging, and need for mesh removal. Defect size, mesh size, and history of prior abdominal operations and infection were also recorded.

RESULTS

Patients received Strattice® with an average area of 132.2 (24-250)cm² and primary closure was achieved over a mesh underlay in three (60%) patients, while the remaining required a bridging approach secondary to lateral defects. Complications included suture extrusion, requiring suture removal, hernia recurrence without bulge, noted incidentally, and seroma formation, requiring placement of drains.

DISCUSSION/CONCLUSIONS

In conclusion, the use of porcine ADM in pediatric patients appears to be potentially safe and efficacious in the context of complex abdominal wall defects, including those with substantial contamination. Our small series builds on previous reports in this difficult patient population. Although additional study, with larger subject pools, would assist in solidifying the observations seen in this and other series, initial findings suggest that porcine ADM is a valuable tool in the treatment of these complex patients.

LEVEL OF EVIDENCE

Case series: Treatment study, Level IV.

Effectiveness and versatility of biological prosthesis in transplanted patients

AIM

To emphasize the effectiveness and versatility of prosthesis, and good tolerance by patients with incisional hernia (IH).

METHODS

From December 2001 to February 2016, 270 liver transplantations were performed at San Camillo Hospital. IH occurred in 78 patients (28.8%). IH usually appeared early within the first year post-orthotopic liver transplantation. In the first era, fascial defect was repaired by primary closure for defects smaller than 2.5 cm or with synthetic mesh for greater defects. Recently, we started using biological mesh (Permacol™, Covidien). We present a series of five transplanted patients submitted to surgery for abdominal wall defect correction repaired with biological mesh (Permacol™, Covidien).

RESULTS

In our cases, the use of biological prosthesis (Permacol™, Covidien) have proven to be effective and versatile in repairing hernia defects of different kinds; patients did not suffer infections of the prosthesis and no recurrence was observed. Furthermore, the prosthesis remains intact even in the years after surgery.

CONCLUSION

The cases that we presented show that the use of biological mesh (Permacol™, Covidien) in transplanted patients may be safe and effective, being careful in the management of perioperative immunosuppression and renal and graft function, although the cost of the product itself has been the main limiting factor and there is need for prospective studies for further evaluations.

Hospital wide porcine mesh conversion results in cost savings with equivalent clinical outcomes

BACKGROUND

A variety of biologic mesh is available for ventral hernia repair. Despite widely variable costs, there is no data comparing cost of material to clinical outcome.

METHODS

Biologic mesh product change was examined. A prospective survey was done to determine appropriate biologic mesh utilization, followed by a retrospective chart review of those treated from Sept. 2012 to Aug. 2013 with Strattice™ and from Sept. 2013 to Aug. 2014 with Permacol™. Outcome variables included complications associated with each material, repair success, and cost difference over the two periods.

RESULTS

28 patients received Strattice™ and 41 Permacol™. There was no statistical difference in patient factors, hernia characteristics, length of stay, readmission rates or surgical site infections at 30 days. The charges were significantly higher for Strattice™ with the median cost $8940 compared to $1600 for Permacol™ (p < 0.001). Permacol™ use resulted in a savings if $181,320.

CONCLUSIONS

Permacol™ use resulted in similar clinical outcomes with significant cost savings when compared to Strattice™. Biologic mesh choice should be driven by a combination of clinical outcomes and product cost.

How much does decompressive laparotomy reduce the mortality rate in primary abdominal compartment syndrome?: A single-center prospective study on 66 patients

Contribution of decompressive laparotomy within the framework of the complex therapeutic algorithm of abdominal compartment syndrome (ACS) is cited with an extremely heterogeneous percentage in terms of survival. The purpose of this study was to present new data regarding contribution of each therapeutic step toward decreasing the mortality of this syndrome.This is a longitudinal prospective study including 134 patients with risk factors for ACS. The intra-abdominal pressure was measured every hour indirectly based on transvesical approach and the appearance of organ dysfunction. Specific therapy for ACS was based on the 2013 World Society of Abdominal Compartment Syndrome guidelines, which include laparotomy decompression. Management of the temporarily open abdomen included an assisted vacuum wound therapy.Of 134 patients, 66 developed ACS. The average intra-abdominal pressure significantly decreased after therapy and decompression surgery. The overall rate of mortality was 27.3% with statistical significance in necrotizing infected pancreatitis. Surgical decompression performed within the first 24 hours after the onset of ACS had a protective role against mortality (odds ratio <1). The average time after which laparotomy decompression was performed was 16.23 hours. The complications occurred during TAC were 2 wound suppurations and 1 intestinal obstruction. Wound suppurations evolved favorably by using vacuum wound-assisted therapy associated with the general treatment, whereas for occlusion, resurgery was performed after which adhesions dissolved. The final closure of the abdomen was performed at a mean of 11.7 days (min. = 9, max. = 14). The closure type was primary suture of the musculoaponeurotic edges in 4 cases, and the use of dual mesh in the other 11 cases.The highest mortality rate in the study group was registered in patients with necrotizing pancreatitis and the lowest in trauma group. Surgical decompression within the framework of the complex algorithm treatment of ACS contributed to the reduction of mortality by 8.7%. It is extremely important that the elapsed time since the initiation of the ACS until the surgical decompression is minimal (under 24 hours).

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.

Practical Approaches to Definitive Reconstruction of Complex Abdominal Wall Defects

With advances in abdominal surgery and the management of major trauma, complex abdominal wall defects have become the new surgical disease, and the need for abdominal wall reconstruction has increased dramatically. Subsequently, how to reconstruct these large defects has become a new surgical question. While most surgeons use native abdominal wall whenever possible, evidence suggests that synthetic or biologic mesh needs to be added to large ventral hernia repairs. One particular group of patients who exemplify "complex" are those with contaminated wounds, enterocutaneous fistulas, enteroatmospheric fistulas, and/or stoma(s), where synthetic mesh is to be avoided if at all possible. Most recently, biologic mesh has become the new standard in high-risk patients with contaminated and dirty-infected wounds. While biologic mesh is the most common tissue engineered used in this field of surgery, level I evidence is needed on its indication and long-term outcomes. Various techniques for reconstructing the abdominal wall have been described, however the long-term outcomes for most of these studies, are rarely reported. In this article, I outline current practical approaches to perioperative management and definitive abdominal reconstruction in patients with complex abdominal wall defects, with or without fistulas, as well as those who have lost abdominal domain.

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.