A decade of ventral incisional hernia repairs with biologic acellular dermal matrix: what have we learned?

Meshing around: high-risk hernias and infected mesh

Open laparotomy carries a risk up to 20% for an incisional hernia, making repair one of the most common operations performed by general surgeons in the USA. Despite a multitude of mesh appliances and techniques, no size fits all, and there is continued debate on what is the best mesh type, especially in high-risk patients with contaminated hernias. Infected mesh carries a significant burden to the patient, the surgeon and overall healthcare costs with medical legal implications. A stepwise approach that involves optimization of patient comorbidities, patient selective choice of mesh and technique is imperative in mitigating outcomes and recurrence rates. This review will focus on the avoidance of mesh infection and the selection of mesh in patients with contaminated wounds.

Mesh Type With Ventral Hernia Repair: A Systematic Review and Meta-analysis of Randomized Trials

INTRODUCTION

Synthetic mesh is widely utilized for clean ventral hernia repair; however, it is unclear if synthetic mesh provides the same benefits with high-risk patients or during contaminated cases. Many surgeons use biologic mesh in these settings, but there is little evidence to support this practice. Our objective was to compare the clinical outcomes of utilizing biologic mesh versus synthetic mesh during ventral hernia repair.

METHODS

Following Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines, a review of the literature was conducted using Cochrane library, EMBASE, Clinicaltrials.gov, and PubMed for randomized controlled trials published that compared biologic versus synthetic mesh during ventral hernia repair. The primary outcome was major complications defined as deep or organ space surgical site infection, reoperations, and hernia recurrences.

RESULTS

Of 1889 manuscripts screened, four publications were included. The four studies included a total of 758 patients, with 381 receiving biologic mesh and 377 receiving synthetic mesh. Compared to biologic mesh, synthetic mesh had lower rates of major complications (38.6% versus 23.4, risk ratio = 0.55, 95% confidence interval = 0.35 to 0.86, P = 0.009) and hernia recurrence (24.5 % versus 10.3%, risk ratio = 0.44, 95% confidence interval = 0.28 to 0.69, P = 0.004). In addition, there was a lower percentage of surgical site infection and reoperation in the synthetic mesh group.

CONCLUSIONS

Contrary to current surgical teaching, placement of permanent synthetic mesh into a contaminated field yielded rates of complications that were comparable or reduced compared to biologic mesh.

Rise of Acellular Dermal Matrix: Cost Consciousness, Industry Payment, and Publication Productivity

BACKGROUND

Despite high cost and lack of FDA approval for breast surgery, acellular dermal matrix (ADM) has become commonplace in reconstructive surgery and has been the focus of more than 500 plastic surgery publications since its wide adoption. We hypothesized that ADM-related academic output would correlate with public interest and industry funding.

STUDY DESIGN

All PubMed-indexed studies focusing on ADM in 11 plastic surgery journals were included (n = 535). Data on industry funding to the 17 most productive authors were extracted from the Open Payments Database. Google Trends in "breast surgery cost" and related terms were queried. Relationships among publication quantity, author industry funding, and public interest were analyzed by Pearson's correlation and linear regression.

RESULTS

The most published authors produced 8 qualifying publications on average (range 5 to 17), with 80% focused on breast surgery. These individuals grossed a total of $19 million industry dollars overall with $17 million (89%) in nonconsulting compensation from ADM-producing companies (NC-ADM). Individual total compensation and NC-ADM compensation, by quartile, were $194,000/$320,000/$1.25 million and $17,000/$210,000/$1.1 million, respectively. These variables showed strong correlation with individual publication rate with a linear regression coefficient of $110K in NC-ADM per publication (p < 0.01). Authors disclosed funding in a mean ± SD of 65 ± 26% of their work with strong correlation between disclosure and NC-ADM (p < 0.01). Google "breast surgery cost" search volume has grown rapidly in significant correlation with ADM publications (p = 0.02).

CONCLUSIONS

This study demonstrates significant correlation between ADM-related publication, industry funding, funding disclosure, and public interest. Education in the potential for such relationships and the importance of objectivity in plastic surgery warrants discussion.

Comparative long-term effectiveness between ventral hernia repairs with biosynthetic and synthetic mesh

BACKGROUND

Debate exists regarding the most appropriate type of mesh to use in ventral hernia repair (VHR). Meshes are broadly categorized as synthetic or biologic, each mesh with individual advantages and disadvantages. More recently developed biosynthetic mesh has characteristics of both mesh types. The current study aims to examine long-term follow-up data and directly compare outcomes-specifically hernia recurrence-of VHR with biosynthetic versus synthetic mesh.

METHODS

With IRB approval, consecutive cases of VHR (CPT codes 49,560, 49,561, 49,565, and 49,566 with 49,568) performed between 2013 and 2018 at a single institution were reviewed. Local NSQIP data was utilized for patient demographics, perioperative characteristics, CDC Wound Class, comorbidities, and mesh type. A review of electronic medical records provided additional variables including hernia defect size, postoperative wound events to six months, duration of follow-up, and incidence of hernia recurrence. Longevity of repair was measured using Kaplan-Meier method and adjusted Cox proportional hazards regression.

RESULTS

Biosynthetic mesh was used in 101 patients (23%) and synthetic mesh in 338 (77%). On average, patients repaired using biosynthetic mesh were older than those with synthetic mesh (57 vs. 52 years; p = .008). Also, ASA Class ≥ III was more common in biosynthetic mesh cases (70.3% vs. 55.1%; p = .016). Patients repaired with biosynthetic mesh were more likely than patients with synthetic mesh to have had a prior abdominal infection (30.7% vs. 19.8%; p = .029). Using a Kaplan-Meier analysis, there was not a significant difference in hernia recurrence between the two mesh types, with both types having Kaplan Meir 5-year recurrence-free survival rates of about 72%.

CONCLUSION

Using Kaplan-Meier analysis, synthetic mesh and biosynthetic mesh result in comparable hernia recurrence rates and surgical site infection rates in abdominal wall reconstruction patients with follow-up to as long as five years.

Biologic vs Synthetic Mesh for Single-stage Repair of Contaminated Ventral Hernias: A Randomized Clinical Trial

IMPORTANCE

Biologic mesh is widely used for reinforcing contaminated ventral hernia repairs; however, it is expensive and has been associated with high rates of long-term hernia recurrence. Synthetic mesh is a lower-cost alternative but its efficacy has not been rigorously studied in individuals with contaminated hernias.

OBJECTIVE

To determine whether synthetic mesh results in superior reduction in risk of hernia recurrence compared with biologic mesh during the single-stage repair of clean-contaminated and contaminated ventral hernias.

DESIGN, SETTING, AND PARTICIPANTS

This multicenter, single-blinded randomized clinical trial was conducted from December 2012 to April 2019 with a follow-up duration of 2 years. The trial was completed at 5 academic medical centers in the US with specialized units for abdominal wall reconstruction. A total of 253 adult patients with clean-contaminated or contaminated ventral hernias were enrolled in this trial. Follow-up was completed in April 2021.

INTERVENTIONS

Retromuscular synthetic or biologic mesh at the time of fascial closure.

MAIN OUTCOMES AND MEASURES

The primary outcome was the superiority of synthetic mesh vs biologic mesh at reducing risk of hernia recurrence at 2 years based on intent-to-treat analysis. Secondary outcomes included mesh safety, defined as the rate of surgical site occurrence requiring a procedural intervention, and 30-day hospital direct costs and prosthetic costs.

RESULTS

A total of 253 patients (median [IQR] age, 64 [55-70] years; 117 [46%] male) were randomized (126 to synthetic mesh and 127 to biologic mesh) and the follow-up rate was 92% at 2 years. Compared with biologic mesh, synthetic mesh significantly reduced the risk of hernia recurrence (hazard ratio, 0.31; 95% CI, 0.23-0.42; P < .001). The overall intent-to-treat hernia recurrence risk at 2 years was 13% (33 of 253 patients). Recurrence risk with biologic mesh was 20.5% (26 of 127 patients) and with synthetic mesh was 5.6% (7 of 126 patients), with an absolute risk reduction of 14.9% with the use of synthetic mesh (95% CI, -23.8% to -6.1%; P = .001). There was no significant difference in overall 2-year risk of surgical site occurrence requiring a procedural intervention between the groups (odds ratio, 1.22; 95% CI, 0.60-2.44; P = .58). Median (IQR) 30-day hospital direct costs were significantly greater in the biologic group vs the synthetic group ($44 936 [$35 877-$52 656] vs $17 289 [$14 643-$22 901], respectively; P < .001). There was also a significant difference in the price of the prosthetic device between the 2 groups (median [IQR] cost biologic, $21 539 [$20 285-$23 332] vs synthetic, $105 [$105-$118]; P < .001).

CONCLUSIONS AND RELEVANCE

Synthetic mesh demonstrated superior 2-year hernia recurrence risk compared with biologic mesh in patients undergoing single-stage repair of contaminated ventral hernias, and both meshes demonstrated similar safety profiles. The price of biologic mesh was over 200 times that of synthetic mesh for these outcomes.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02451176.

Clinical applications of acellular dermal matrices: A review

INTRODUCTION

The extracellular matrix (ECM) plays an integral role in wound healing. It provides both structure and growth factors that allow for the organised cell proliferation. Large or complex tissue defects may compromise host ECM, creating an environment that is unfavourable for the recovery of anatomical function and appearance. Acellular dermal matrices (ADMs) have been developed from a variety of sources, including human (HADM), porcine (PADM) and bovine (BADM), with multiple different processing protocols. The objective of this report is to provide an overview of current literature assessing the clinical utility of ADMs across a broad spectrum of applications.

METHODS

PubMed, MEDLINE, EMBASE, Scopus, Cochrane and Web of Science were searched using keywords 'acellular dermal matrix', 'acellular dermal matrices' and brand names for commercially available ADMs. Our search was limited to English language articles published from 1999 to 2020 and focused on clinical data.

RESULTS

A total of 2443 records underwent screening. After removing non-clinical studies and correspondence, 222 were assessed for eligibility. Of these, 170 were included in our synthesis of the literature. While the earliest ADMs were used in severe burn injuries, usage has expanded to a number of surgical subspecialties and procedures, including orthopaedic surgery (e.g. tendon and ligament reconstructions), otolaryngology, oral surgery (e.g. treating gingival recession), abdominal wall surgery (e.g. hernia repair), plastic surgery (e.g. breast reconstruction and penile augmentation), and chronic wounds (e.g. diabetic ulcers).

CONCLUSION

Our understanding of ADM's clinical utility continues to evolve. More research is needed to determine which ADM has the best outcomes for each clinical scenario.

LAY SUMMARY

Large or complex wounds present unique reconstructive and healing challenges. In normal healing, the extracellular matrix (ECM) provides both structural and growth factors that allow tissue to regenerate in an organised fashion to close the wound. In difficult or large soft-tissue defects, however, the ECM is often compromised. Acellular dermal matrix (ADM) products have been developed to mimic the benefits of host ECM, allowing for improved outcomes in a variety of clinical scenarios. This review summarises the current clinical evidence regarding commercially available ADMs in a wide variety of clinical contexts.

Regenerative Engineering: Current Applications and Future Perspectives

Many pathologies, congenital defects, and traumatic injuries are untreatable by conventional pharmacologic or surgical interventions. Regenerative engineering represents an ever-growing interdisciplinary field aimed at creating biological replacements for injured tissues and dysfunctional organs. The need for bioengineered replacement parts is ubiquitous among all surgical disciplines. However, to date, clinical translation has been limited to thin, small, and/or acellular structures. Development of thicker tissues continues to be limited by vascularization and other impediments. Nevertheless, currently available materials, methods, and technologies serve as robust platforms for more complex tissue fabrication in the future. This review article highlights the current methodologies, clinical achievements, tenacious barriers, and future perspectives of regenerative engineering.

Resorbable Synthetic Ventral Hernia Repair in Contaminated Fields: Outcomes with Poly-4-Hydroxybutyrate Mesh

BACKGROUND

Hernia repair in the setting of contamination poses unique challenges, including complications such as recurrence and mesh infection. The ideal contaminated hernia repair including type of mesh use remains controversial. Poly-4-hydroxybutyrate is a biosynthetic scaffold for soft-tissue reinforcement and hernia repair and is potentially useful in contaminated hernia repair. The authors aim to describe postoperative outcomes, recurrence, and patient-reported outcomes after contaminated hernia repair with poly-4-hydroxybutyrate.

METHODS

Adult patients (≥18 years) undergoing a contaminated hernia repair with poly-4-hydroxybutyrate (Phasix) performed by a single plastic surgeon between January of 2015 and May of 2020 were identified. Patients with a ventral hernia defect and a Centers for Disease Control and Prevention wound class of II, III, or IV were included. Primary outcomes included recurrence, surgical-site infection, surgical-site occurrences, and surgical-site infection/occurrences requiring procedural interventions. As a secondary outcome, the authors assessed patient-reported outcomes as defined by the Abdominal Hernia-Q and Hernia-Related Quality of Life Survey.

RESULTS

Sixty patients were included with a median age of 52.5 and body mass index of 31 kg/m2. Median defect size was 300 cm2. Twenty-eight patients (46.7 percent) experienced a complication. The most common complications were surgical-site occurrence [n = 20 (33.3 percent)] and surgical-site infection [n = 10 (16.7 percent)]. Median follow-up was 24.2 months, with a recurrence rate of 8.3 percent (n = 4). Overall patient-reported outcomes improved postoperatively, and improvement was not affected by the presence of a complication.

CONCLUSIONS

Poly-4-hydroxybutyrateuse in contaminated hernia repair shows promising results with an acceptable safety profile. Although complications are frequent in this complex cohort, patient-reported outcomes improvement was significant even in patients with complications.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

An evaluation of clinical and quality of life outcomes after ventral hernia repair with poly-4-hydroxybutyrate mesh

PURPOSE

Despite continued efforts, recurrence after ventral hernia repair (VHR) remains a common problem. Biosynthetic Phasix^™ (Poly-4-Hydroxybutyrate, P4HB) mesh combines the durability of synthetic mesh with the bio-resistance of biologics. P4HB has shown promising early outcomes, but long-term data are lacking. We examine patients following VHR with P4HB with at least 3 years of follow-up to assess clinical and patient reported outcomes (PROs).

METHODS

Adult patients (≥ 18 years old) undergoing VHR with P4HB mesh between 10/2015 and 01/2018 by a single surgeon were retrospectively identified. Patients with < 36 months of follow-up were excluded unless they had a documented recurrence. Clinical outcomes and quality of life using the Hernia-Related Quality of Life Survey (HerQLes) were assessed.

RESULTS

Seventy-one patients were included with a median age and body mass index of 61.2 and 31 kg/m², respectively. Mesh was placed in the retromuscular (79%) and onlay (21%) planes with 1/3 of patients having hernias repaired in contaminated fields. There were no mesh infections, enterocutaneous fistulas, or mesh explantations. Nine patients (12.7%) developed recurrence at a median follow-up of 43.1 months [38.2-49.1]. Mesh plane, fixation technique, and Ventral Hernia Working Group were not associated with recurrence. Significant improvement in disease-specific PROs was observed and maintained at 3-year follow-up.

CONCLUSION

Longitudinal clinical and quality of life outcomes after clean and contaminated VHR with P4HB are limited. Here, we conclude that P4HB is an effective and versatile mesh option for use in abdominal wall reinforcement.

Onlay Poly-4-Hydroxybutyrate (P4HB) Mesh for Complex Hernia: Early Clinical and Patient Reported Outcomes

BACKGROUND

While mesh re-enforcement and advanced surgical techniques are cornerstones of complex ventral hernia repair (CVHR), the risk of complications and recurrence is common. We aim to evaluate the efficacy, safety, and patient reported outcomes (PROs) of patients undergoing CVHR with onlay Poly-4-hydroxybutyrate (P4HB).

METHODS

Adult (>18 y old) patients undergoing VHR with P4HB (Phasix) in the onlay plane by a single surgeon from 01/2015 to 05/2020 were reviewed. VHR was considered complex if patients had significant co-morbidities, large abdominal wall defects, a history of extensive abdominal surgery, and/or concurrent intra-abdominal pathology. A composite of postoperative outcomes including surgical site occurrences (SSO), surgical site infection (SSI), and surgical site occurrences requiring procedural intervention (SSOpi), as well as PROs as defined by the Abdominal Hernia-Q (AHQ), were analyzed.

RESULTS

A total of 51 patients were included with average age and body mass index of 56.4 and 29.9 kg/m². Median follow up was 20 mo with a hernia recurrence rate of 5.9% (n = 3). 21 patients had an SSO (41.2%), 8 had an SSI (15.7%), and 6 had an SSOpi (11.8%). There was an association with Ventral Hernia Working Group ≥ 2 and development of SSO. There was a significant improvement in overall PROs (P < 0.0001) with no difference in those patients with and without complications (P > 0.05).

CONCLUSION

For hernia patients with large defects and complex intra-abdominal pathology, a safe and effective repair is difficult. The use of onlay P4HB was associated with acceptable postoperative outcomes and recurrence rate.

Preventing Recurrence in Clean and Contaminated Hernias Using Biologic Versus Synthetic Mesh in Ventral Hernia Repair: The PRICE Randomized Clinical Trial

OBJECTIVE

The aim of this study was to evaluate which mesh type yields lower recurrence and complication rates after ventral hernia repair.

SUMMARY BACKGROUND DATA

More than 400,000 ventral hernia repairs are performed annually in the United States. Although the most effective method for repairing ventral hernias involves using mesh, whether to use biologic mesh versus synthetic mesh is controversial.

METHODS

Single-blind, randomized, controlled, pragmatic clinical trial conducted from March 2014 through October 2018; 165 patients enrolled with an average follow up of 26 months. Patients were randomized 1:1 to have their ventral hernias repaired using either a biologic (porcine) or synthetic (polypropylene) mesh. The primary study outcome measure was hernia recurrence at 2 years.

RESULTS

A total of 165 patients (68 men), mean age 55 years, were included in the study with a mean follow-up of 26 months. An intention-to-treat analysis noted that hernias recurred in 25 patients (39.7%) assigned to biologic mesh and in 14 patients (21.9%) assigned to synthetic mesh (P = 0.035) at 2 years. Subgroup analysis identified an increased rate of hernia recurrence in the biologic versus the synthetic mesh group under contaminated wound conditions (50.0% vs 5.9%; P for interaction = 0.041). Postoperative complication rates were similar for the 2 mesh types.

CONCLUSIONS

The risk of hernia recurrence was significantly higher for patients undergoing ventral hernia repair with biologic mesh compared to synthetic mesh, with similar rates of postoperative complications. These data indicate that the use of synthetic mesh over biologic mesh to repair ventral hernias is effective and can be endorsed, including under contaminated wound conditions.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02041494.

Bilateral transversus abdominis release: Complex hernia repair without sacrificing quality of life

BACKGROUND

Transversus Abdominis Release (TAR) during ventral hernia repair (VHR) allows for further lateral dissection by dividing the transversus abdominis muscles (TAM). The implications of division of the TAM on clinical and patient-reported outcomes has not be extensively studied.

METHODS

Adult patients undergoing retrorectus (RR) VHR with biosynthetic mesh with or without bilateral TAR were retrospectively identified. Post-operative and patient-reported outcomes (PROs) were collected.

RESULTS

Of 50 patients, 24 underwent TAR and 26 had RR repair alone. Median defect sizes were 449 cm² and 208 cm², respectively (p < 0.001). Rates of SSO and SSI were similar (p > 0.05). One TAR patient (4.2%) and four RR patients (15.4%) recurred (p = 0.26), with median follow up of 24 and 38 months. PROs improved significantly in both groups (p < 0.05).

CONCLUSION

Despite more complex abdominal wall reconstruction on larger defects, TAR has minimal major adverse events, low recurrence rates, and does not negatively affect PROs.

Ventral hernia repair with synthetic mesh in a contaminated field: a systematic review and meta-analysis

PURPOSE

The use of mesh in ventral hernia repair becomes especially challenging when associated with a contaminated field. Permanent synthetic mesh use in this setting is currently debated and this discussion is yet to be resolved clinically or in the literature. We aim to systematically assess postoperative outcomes of non-absorbable synthetic mesh (NASM) used in ventral hernia repair in the setting of contamination.

METHODS

A literature search of PubMed, Embase, Scopus, Cinahl, and Cochrane Library identified all articles from 2000-2020 that examined the use of NASM for ventral hernia repair in a contaminated field. Postoperative outcomes were assessed by means of pooled analysis and meta-analysis. Qualitative analysis was completed for all included studies using a modified Newcastle-Ottawa scale.

RESULTS

Of 630 distinct publications and 104 requiring full review, this study included 17 articles published between 2007 and 2020. Meta-analysis demonstrated absorbable mesh was associated with more HR (OR 1.89, 1.15-3.12, p = 0.008), SSO (OR 1.43, 0.96-2.11, p = 0.087), SSI (OR 2.84, 1.85-4.35, p < 0.001), and unplanned reoperation (OR 1.99, 1.19-3.32, p = 0.009) compared to NASM.

CONCLUSION

The use of NASM for ventral hernia repair in a contaminated field may be a safe alternative to absorbable mesh, as evidenced by lower rates of postoperative complications. This review counters the current clinical paradigm, and additional prospective randomized controlled trials are warranted.

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

BACKGROUND

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Biological mesh used to repair perineal hernias following abdominoperineal resection for anorectal cancer

PURPOSE

This study aimed to determine the outcome for patients who had undergone perineal hernia repair, via a perineal approach, using a biological mesh post-abdominoperineal excision (APE) for anorectal cancer.

METHOD

All consecutive patients having undergone perineal hernia repair involving an extracellular matrix of porcine small intestinal submucosa at our hospital between 2015 and 2018 were included. Follow-up clinical examinations and computed tomography scans were performed.

RESULTS

Six patients were treated surgically for symptomatic perineal hernia after a median of 31 months from APE. The median follow-up after hernia repair was 11 months (interquartile range [IQR], 6-35 months). Three patients (50%) developed a recurrent perineal hernia after a median interval of 6 months.

CONCLUSION

Perineal hernia repair using a biological mesh resulted in a high recurrence rate in patients who had undergone APE for anorectal cancer.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Comparison of biosynthetic versus synthetic mesh in clean and contaminated ventral hernia repairs

BACKGROUND

Abdominal hernias are an increasingly common presentation due to obesity, ageing and prevalence of prior abdominal surgery. Mesh repair is the mainstay of treatment; however, mesh selection remains largely subjective. There are little data available to assess the performance of biosynthetic meshes against synthetic meshes across all wound types. This study assessed the 6-month outcomes of a single surgeon's cohort of ventral hernia repairs performed with either GORE BIO-A (BioA) or Parietex ProGrip (ProGrip).

METHODS

Retrospective case cohort study across two centres with patients undergoing repair by a single surgeon (KS) between January 2014 and April 2018 was conducted. All hernia repairs were performed with either BioA (n = 55) or ProGrip mesh (n = 60). Outcomes were monitored for 6 months post repair. Wounds were classified according to the Centre for Disease Control Wound Status. Outcomes measured were length of stay, general complications, wound complications and hernia recurrence.

RESULTS

The overall complication rate and length of stay were similar for both groups. In clean wounds, the complication rate was equivalent for BioA and ProGrip (34% versus 22%, P = 0.22). There was a significant difference in complication rates in contaminated wounds - BioA 17% versus ProGrip 100% (P = 0.004). BioA performed equivocally in clean and contaminated wounds (34% versus 17%, P = 0.178), whereas ProGrip performed worse in contaminated wounds (22% versus 100%, P = 0.016).

CONCLUSION

Our results suggest that BioA is a suitable, if not preferable, choice for contaminated hernia repair. In this cohort, BioA was also demonstrated as safe and equivalent to ProGrip mesh in clean hernia wounds.

Hernia recurrence and infection rate in elective complex abdominal wall repair using biologic mesh

Background

Elective complex ventral hernia repairs, done using synthetic mesh in patients with comorbidities, can result in mesh related complications such as hernia recurrence or infection. We studied hernia recurrence and surgical site occurrences after elective complex repairs in predominately clean cases using biologic mesh and examined the impact of several comorbidities.

Methods

A retrospective chart review was completed on patients who underwent elective repair with biologic mesh in clean/clean-contaminated settings between 2012 and 2015 with a minimum of 1-year follow-up. Multiple comorbid conditions, including diabetes, chronic obstructive pulmonary disease, steroid use, smoking history and previous hernia repairs were identified. Post-operative complications including recurrence and infections were ruled out by computed tomography, clinical exam, and/or by telephone survey.

Results

40 patients were identified. 85% (n = 34) had class 1 wounds. 25% (n = 10) experienced a hernia recurrence. 10% (n = 4) of patients developed postoperative infection, none required mesh explantation or re-operation. No statistically significant association was found between the comorbidities assessed and recurrence/infection rates.

Conclusions

We present the first study analyzing clinical outcomes of complex ventral hernia repairs using biologic mesh in predominately clean settings. This study being non-comparative limits definitive conclusions, but our aim is to add to the growing literature on biologic mesh to help future researchers performing comparative trials of synthetic versus biologic meshes.

Randomized Controlled Trial Of Lichtenstein Repair Of Indirect Inguinal Hernias With Two Biologic Meshes From Porcine Small Intestine Submucosa

Background

Biologic mesh is a newly developed material for hernia repairs which has been successfully used in clinical practices. This study aims to evaluate the clinical efficacy between patients undergoing a Lichtenstein’s hernioplasty with a new biologic mesh derived from porcine small intestine submucosal (SIS) extracellular matrix versus a standard SIS mesh.

Methods

A prospective, randomized, double-blinded, multi-center trial was conducted in a 6-month study. Lichtenstein hernioplasty was performed using the new SIS mesh (Beijing Biosis Healing Biotechnology) or the standard SIS mesh (Biodesign Surgisis, Cook Biotech). The postoperative follow-up examinations were carried out at during hospitalization, 1st week, 1st, 3rd, and 6th month after surgery. The primary outcome was the excellent and good rate of recovery. Secondary outcomes included recurrence rate, complications, and patient-centered outcomes.

Results

A total of 194 patients were randomized into experimental group receiving the new SIS mesh (n=97) and control group receiving the standard SIS mesh (n=97). The excellent and good rate of rehabilitation in the experimental group was 98.97%, while it was 100.00% in the control group (P>0.05). One patient had a recurrence in the experimental group, while there was no recurrence in the control group (P>0.05). Other clinical outcomes, including the length of operation or hospitalization, foreign body sensation in the inguinal area, incision healing, infection, postoperative chronic pain, postoperative allergy, hydrocele, and orchitis, were similar between the two groups.

Conclusion

Lichtenstein hernioplasty using the SIS mesh was safe and effective, and the new SIS mesh tested in this study had comparable safety and efficacy to the wildly used SIS mesh.

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.

Free radical-decellularized tissue promotes enhanced antioxidant and anti-inflammatory macrophage response

Oxidative stress leads to the progression of many diseases including chronic wounds, atherosclerosis, stroke and cancer. The modification of biomolecules with reactive nitrogen or oxygen species has been shown to trigger oxidative stress pathways that are beneficial for healing. Extracellular matrix scaffolds have been used successfully in reconstructive applications due to the beneficial host response they induce. To tailor extracellular matrix scaffolds to enhance antioxidant response, ECM were prepared using reactive nitrogen or oxygen species. These scaffolds were shown to be effectively decellularized and possess oxidative or nitroxidative protein modifications. Macrophage responses in vitro and in an in vivo muscle injury model were shown to have enhanced antioxidant phenotypes without impairment of long-term remodeling. These observations suggest that ECM decellularized with reactive oxygen or nitrogen species could provide better outcomes for the treatment of ischemic diseases.

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.

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.

"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.

Combined single-stage enterolysis with pedicle seromuscular bowel flaps, myocutaneous and fasciocutaneous flaps to repair recurrent enterocutaneous fistulas in complex abdominal Wall defects

INTRODUCTION

Reconstruction of abdominal wall defects with enterocutaneous fistulas (ECF) remains challenging. The purpose of this report is to describe a single-stage approach using combined microscopic enterolysis, pedicle seromuscular bowel flaps, mesh, fasciocutaneous, and myocutaneous flaps.

METHODS

Between 1990 and 2016 a retrospective review identified a total of 18 patients with an average age of 39 years (ranging 26-59 years). Thirteen cases were associated with trauma, four were complication of previous mesh repair, and one was after an aortic dissection. Average diameter of defect size was 22 cm (ranging 20-24 cm). Surgical technique involved enterolysis using microscope magnification, a pedicle seromuscular bowel flap to reinforce the bowel anastomosis, mesh, musculocutaneous, and fasciocutaneous flaps to reconstruct the abdominal wall.

RESULTS

Fifteen patients required rotational flaps with an average skin paddle area of 442.7 cm² (ranging 440 cm² -260 cm² ) and 10 patients required a serosal patch with an average length of 5 cm (ranging 4-6 cm). Complications included three wound dehiscence and one abdominal wall bulging. Flap survival was 100%. The majority of patients (12 out of 18) were able to resume normal activities, and the remaining (n = 6) were able to resume most activities. Functional outcome as assessed by 36-Item Short Form Survey (SF-36) physical function component questionnaire at 18-24 months follow up was 67.8% (ranging from 59 to 72%). Mean length of hospital stay was 2.2 weeks (ranging 1.4-2.7 weeks). Mean follow-up was 24 months (ranging 22-26 months) with clinical examination.

CONCLUSION

Microscopically assisted intra-abdominal dissection with resection of diseased bowel, replacement with well-vascularized tissue at the anastomosis site in, and reinforcement with mesh combined with pedicle musculocutaneous and fasciocutaneous flaps may be an alternative when other local reconstructive options have failed.

Quality measures in ventral hernia repair: a systematic review

BACKGROUND

The US healthcare system is shifting towards reimbursement for quality over quantity of care. Quality measures are tied to financial incentives in these healthcare models. It is important that surgeons become familiar with quality measures addressing ventral hernia repair and understand candidate measures that may drive future quality measure development.

STUDY DESIGN

We performed a systematic review of society websites, quality measure databases, and the literature (Pubmed, Embase/Scopus, and Google Scholar) for quality measures addressing ventral hernia surgery. Clinical practice guidelines were included as candidate quality measures. All measures were categorized as structure, process or outcome according to Donabedian domains, as well as within the six National Quality Strategy (NQS) domains.

RESULTS

Thirty quality measures and candidate measures were identified. Eight candidate measures from the American Hernia Society addressed ventral hernia repair, and 22 quality measures in general surgery were also relevant to ventral hernia repair. Of the candidate measures, 6 (75%) were outcome and 2 (25%) were process measures. Of existing general surgery quality measures, 9 (41%) were outcome and 13 (59%) were process measures. No structural measures were identified. Overall, the majority of measures addressed NQS priorities of effective clinical care (33%) and patient safety (27%), while few addressed other domains.

CONCLUSION

Both the Donabedian domains of quality and NQS priorities were unequally represented in the current measures addressing ventral hernia repair. Recognizing and addressing the under-represented areas will provide a more balanced framework for developing quality measures and ensure that ventral hernia surgery is appropriately evaluated in value-based payment models.

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.

Cross-Linked Cholecyst-Derived Extracellular Matrix for Abdominal Wall Repair

Abdominal wall repair frequently utilizes either nondegradable or biodegradable meshes, which are found to stimulate undesirable biological tissue responses or which possess suboptimal degradation rate. In this study, a biologic mesh prototype made from carbodiimide cross-linked cholecyst-derived extracellular matrix (EDCxCEM) was compared with small intestinal submucosa (Surgisis^®), cross-linked bovine pericardium (Peri-Guard^®), and polypropylene (Prolene^®) meshes in an in vivo rabbit model. The macroscopic appearance and stereological parameters of the meshes were evaluated. Tailoring the degradation of the EDCxCEM mesh prevents untimely degradation, while allowing cellular infiltration and mesh remodeling to take place in a slower but predictable manner. The results suggest that the cross-linked biodegradable cholecyst-derived biologic mesh results in no seroma formation, low adhesion, and moderate stretching of the mesh. In contrast to Surgisis, Peri-Guard, and Prolene meshes, the EDCxCEM mesh showed a statistically significant increase in the volume fraction (V_v) of collagen (from 34% to 52.1%) in the central fibrous tissue region at both day 28 and 56. The statistically high length density (L_v), of blood vessels for the EDCxCEM mesh at 28 days was reflected also by the higher cellular activity (high V_v of fibroblast and moderate V_v of nuclei) indicating remodeling of this region in the vicinity of a slowly degrading EDCxCEM mesh. The lack of mesh area stretching/shrinkage in the EDCxCEM mesh showed that the remodeled tissue was adequate to prevent hernia formation. The stereo-histological assays suggest that the EDCxCEM delayed degradation profile supports host wound healing processes including collagen formation, cellular infiltration, and angiogenesis. The use of cross-linked CEM for abdominal wall repair is promising.

Soft Tissue Repair with Easy-Accessible Autologous Newborn Placenta or Umbilical Cord Blood in Severe Malformations: A Primary Evaluation

Disrupted organogenesis leads to permanent malformations that may require surgical correction. Autologous tissue grafts may be needed in severe lack of orthotopic tissue but include donor site morbidity. The placenta is commonly discarded after birth and has a therapeutic potential. The aim of this study was to determine if the amnion from placenta or plasma rich of growth factors (PRGF) with mononuclear cells (MNC) from umbilical cord blood (UCB), collected noninvasively, could be used as bio-constructs for autologous transplantation as an easy-accessible no cell culture-required method. Human amnion and PRGF gel were isolated and kept in culture for up to 21 days with or without small intestine submucosa (SIS). The cells in the constructs showed a robust phenotype without induced increased proliferation (Ki67) or apoptosis (caspase 3), but the constructs showed decreased integrity of the amnion-epithelial layer at the end of culture. Amnion-residing cells in the SIS constructs expressed CD73 or pan-cytokeratin, and cells in the PRGF-SIS constructs expressed CD45 and CD34. This study shows that amnion and UCB are potential sources for production of autologous grafts in the correction of congenital soft tissue defects. The constructs can be made promptly after birth with minimal handling or cell expansion needed.

Fetal subcutaneous cells have potential for autologous tissue engineering

Major congenital malformations affect up to 3% of newborns. Infants with prenatally diagnosed soft tissue defects should benefit from having autologous tissue readily available for surgical implantation in the perinatal period. In this study, we investigate fetal subcutaneous cells as cellular source for tissue engineering. Fetal subcutaneous biopsies were collected from elective terminations at gestational Week 20-21. Cells were isolated, expanded, and characterized in vitro. To determine cell coverage, localization, viability, and proliferation in different constructs, the cells were seeded onto a matrix (small intestine submucosa) or in collagen gel with or without poly(ε-caprolactone) mesh and were kept in culture for up to 8 weeks before analysis. Angiogenesis was analysed through a tube-forming assay. Fetal subcutaneous cells could be expanded until 43 ± 3 population doublings, expressed mesenchymal markers, and readily differentiate into adipogenic and osteogenic lineages. The cells showed low adherence to small intestine submucosa and did not migrate deep into the matrix. However, in collagen gels, the cells migrated into the gel and proliferated with sustained viability for up to 8 weeks. The cells in the matrices expressed Ki67, CD73, and α-smooth muscle actin but not cytokeratin or CD31. Fetal cells derived from subcutaneous tissue demonstrated favourable characteristics for preparation of autologous tissue transplants before birth. Our study supports the theory that cells could be obtained from the fetus during pregnancy for tissue engineering purposes after birth. In a future clinical situation, autologous transplants could be used for reconstructive surgery in severe congenital malformations.

Immunomodulation and Mobilization of Progenitor Cells by Extracellular Matrix Bioscaffolds for Volumetric Muscle Loss Treatment

Acellular bioscaffolds composed of extracellular matrix (ECM) have been effectively used to promote functional tissue remodeling in both preclinical and clinical studies of volumetric muscle loss, but the mechanisms that contribute to such outcomes are not fully understood. Thirty-two C57bl/6 mice were divided into eight groups of four animals each. A critical-sized defect was created in the quadriceps muscle and was repaired with a small intestinal submucosa ECM bioscaffold or left untreated. Animals were sacrificed at 3, 7, 14, or 56 days after surgery. The spatiotemporal cellular response in both treated and untreated groups was characterized by immunolabeling methods. Early time points showed a robust M2-like macrophage phenotype following ECM treatment in contrast to the predominant M1-like macrophage phenotype present in the untreated group. ECM implantation promoted perivascular stem cell mobilization, increased presence of neurogenic progenitor cells, and was associated with myotube formation. These cell types were present not only at the periphery of the defect near uninjured muscle, but also in the center of the ECM-filled defect. ECM bioscaffolds modify the default response to skeletal muscle injury, and provide a microenvironment conducive to a constructive healing response.

Extracellular Matrix Bioscaffolds as Immunomodulatory Biomaterials<sup/>

Suppression of the recipient immune response is a common component of tissue and organ transplantation strategies and has also been used as a method of mitigating the inflammatory and scar tissue response to many biomaterials. It is now recognized, however, that long-term functional tissue replacement not only benefits from an intact host immune response but also depends upon such a response. The present article reviews the limitations associated with the traditionally held view of avoiding the immune response, the ability of acellular biologic scaffold materials to modulate the host immune response and promote a functional tissue replacement outcome, and current strategies within the fields of tissue engineering and biomaterials to develop immune-responsive and immunoregulatory biomaterials.

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.

Biologic Scaffolds

Biologic scaffold materials composed of allogeneic or xenogeneic extracellular matrix are commonly used for the repair and functional reconstruction of injured and missing tissues. These naturally occurring bioscaffolds are manufactured by the removal of the cellular content from source tissues while preserving the structural and functional molecular units of the remaining extracellular matrix (ECM). The mechanisms by which these bioscaffolds facilitate constructive remodeling and favorable clinical outcomes include release or creation of effector molecules that recruit endogenous stem/progenitor cells to the site of scaffold placement and modulation of the innate immune response, specifically the activation of an anti-inflammatory macrophage phenotype. The methods by which ECM biologic scaffolds are prepared, the current understanding of in vivo scaffold remodeling, and the associated clinical outcomes are discussed in this article.

2017 update of the WSES guidelines for emergency repair of complicated abdominal wall hernias

Emergency repair of complicated abdominal wall hernias may be associated with worsen outcome and a significant rate of postoperative complications. There is no consensus on management of complicated abdominal hernias. The main matter of debate is about the use of mesh in case of intestinal resection and the type of mesh to be used. Wound infection is the most common complication encountered and represents an immense burden especially in the presence of a mesh. The recurrence rate is an important topic that influences the final outcome. A World Society of Emergency Surgery (WSES) Consensus Conference was held in Bergamo in July 2013 with the aim to define recommendations for emergency repair of abdominal wall hernias in adults. This document represents the executive summary of the consensus conference approved by a WSES expert panel. In 2016, the guidelines have been revised and updated according to the most recent available literature.

Biomimetic tendon extracellular matrix composite gradient scaffold enhances ligament-to-bone junction reconstruction

Management of ligament/tendon-to-bone-junction healing remains a formidable challenge in the field of orthopedic medicine to date, due to deficient vascularity and multi-tissue transitional structure of the junction. Numerous strategies have been employed to improve ligament-bone junction healing, including delivery of stem cells, bioactive factors, and synthetic materials, but these methods are often inadequate at recapitulating the complex structure-function relationships at native tissue interfaces. Here, we developed an easily-fabricated and effective biomimetic composite to promote the regeneration of ligament-bone junction by physically modifying the tendon extracellular matrix (ECM) into a Random-Aligned-Random composite using ultrasound treatment. The differentiation potential of rabbit bone marrow stromal cells on the modified ECM were examined in vitro. The results demonstrated that the modified ECM enhanced expression of chondrogenesis and osteogenesis-associated epigenetic genes (Jmjd1c, Kdm6b), transcription factor genes (Sox9, Runx2) and extracellular matrix genes (Col2a1, Ocn), resulting in higher osteoinductivity than the untreated tendon ECM in vitro. In the rabbit anterior cruciate ligament (ACL) reconstruction model in vivo, micro-computed tomography (Micro-CT) and histological analysis showed that the modified Random-Aligned-Random composite scaffold enhanced bone and fibrocartilage formation at the interface, more efficaciously than the unmodified tendon ECM. Therefore, these results demonstrated that the biomimetic Random-Aligned-Random composite could be a promising scaffold for ligament/tendon-bone junction repair.

STATEMENT OF SIGNIFICANCE

The native transitional region consists of several distinct yet contiguous tissue regions, composed of soft tissue, non-calcified fibrocartilage, calcified fibrocartilage, and bone. A stratified graft whose phases are interconnected with each other is essential for supporting the formation of functionally continuous multi-tissue regions. Various techniques have been attempted to improve adherence of the ligament/tendon graft to bone, including utilization of stem cells, growth factors and biomaterials, but these methods are often inadequate at recapitulating the complex structure-function relationships at native tissue interfaces. Here, we developed an easily-fabricated and effective biomimetic composite to promote the regeneration of ligament-bone junction by physically modifying the tendon extracellular matrix (ECM) into a Random-Aligned-Random composite using ultrasound treatment. The modified ECM enhanced expression of chondrogenesis and osteogenesis-associated epigenetic genes expression in vitro. In the rabbit anterior crucial ligament reconstruction model in vivo, results showed that the modified Random-Aligned-Random composite enhances the bone and fibrocartilage formation in the interface, proving to be more efficient than the unmodified tendon ECM. Therefore, these results demonstrated that the biomimetic Random-Aligned-Random composite could be a promising scaffold for ligament/tendon-bone junction repair.

Incidence, recurrence and risk factors of hernias following stoma reversal

BACKGROUND

To determine the incidence and risk factors for stoma site (SSH) and incisional (IH) hernias following stoma reversal as well as their recurrence following repair.

METHODS

A cohort of VA Surgical Quality Improvement Program patients undergoing stoma reversal from 2002 to 2014 were evaluated at a single institution. Variables were selected a priori and evaluated by univariate analyses.

RESULTS

Of 114 stoma reversals, 63 utilized a midline approach. The incidence of SSH and IH was 9.6% and 31.7% over a median follow-up of 5.7 (0.5-14) and 4.0 (0.1-14) years, respectively. Five SSH and 10 IH were repaired with no recurrences. Myofascial release and superficial surgical site infections (SSI) were associated with SSH while body mass index, preoperative radiotherapy, American Society of Anesthesiologists classification ≥3, operative duration ≥2.5 h and deep SSIs were associated with IH.

CONCLUSIONS

Incisional hernia incidence after stoma reversal is high for both the stoma site and midline. Risk factors differ for each hernia type. A low recurrence rate exists in short term follow-up following repair of a hernia occurrence.

Complex Abdominal Wall Hernia Repair in Contaminated Surgical Fields: Factors Affecting the Choice of Prosthesis

To compare patients with complex abdominal wall hernias undergoing surgical repair using synthetic nonabsorbable or biologic meshes in contaminated fields. Retrospective review of 62 patients with complex abdominal wall hernia with surgical repair in an elective setting and in the context of a clean-contaminated or contaminated fields (January 2009–April 2015). Two groups according to the prosthesis (synthetic nonabsorbable, n = 48 or biologic, n = 14). Mean follow-up was 24.6 (15.8) months. Clean-contaminated wounds were significantly more frequent in the synthetic group. Contaminated wounds were significantly more frequent in the biologic group. Enterocutaneous fistula, recurrent hernia, and removal of chronic infected mesh were significantly more frequently in the biologic group. Differences in postoperative complications and surgical site infections were not found. Recurrence was higher in the biologic group (35.7% vs 8.3%, P = 0.03). In the elective repair of complex hernia, the level of contamination, a recurrent hernia, an enterocutaneous fistula or removal of chronic infected mesh were the factors affecting the choice of prosthesis. In the clean-contaminated setting, the use of a synthetic nonabsorbable mesh versus a biologic mesh did not increase the rate of postoperative infections. Recurrences are significantly higher with biologic meshes.

Abdominal Wall Allograft: Preclinical Biomechanical Investigation of a Novel Reconstructive Adjunct

INTRODUCTION

Acellular dermal matrices have revolutionized abdominal wall reconstruction; however, device failure and hernia recurrence remain significant problems. Fascia grafts are a reconstructive adjunct with increased tensile strength compared with acellular dermal matrices; however, clinical use is limited by insufficient donor material and donor site morbidity. To this end, we investigate the biomechanical properties of human abdominal wall allografts (AWAs) consisting of the anterior rectus sheath from xiphoid to pubis.

METHODS

After cadaveric procurement of 6 human AWAs, the tissue was divided horizontally and a matched-sample study was performed with specimens randomized to 2 groups: fresh, unprocessed versus processed with gamma irradiation and decellularization. Specimens were evaluated for physical properties, DNA content, tensile strength, and electron microscopy.

RESULTS

All AWA donors were male, with a mean age of 55.2 years (range, 35-74 years). Procured AWAs had a mean length of 21.70 ± 1.8 cm, width of 14.30 ± 1.32 cm, and area of 318.50 cm, and processing resulted in a 98.3% reduction in DNA content. Ultimate tensile strength was significantly increased after tissue processing, and after subcutaneous implantation, processed AWA demonstrated 4-fold increased tensile strength compared with unprocessed AWAs.

CONCLUSIONS

Acellular AWAs represent a novel reconstructive adjunct for abdominal wall reconstruction with the potential of replacing "like with like" without additional donor site morbidity or antigenicity.

Complex Ventral Hernia Repair with Acellular Dermal Matrices: Clinical and Quality of Life Outcomes

Acellular dermal matrices (ADMs) are used in conjunction with complex hernia repair, but their efficacy is often debated. This study assesses clinical and quality of life (QOL) outcomes in multiply comorbid patients undergoing complex ventral hernia repair using ADMs. After obtaining institutional review board approval, a prospective study was conducted evaluating patients undergoing complex ventral incisional hernia repair with abdominal wall reconstruction (AWR) using either human (Flex HD) or porcine ADM (Strattice). Patient accrual occurred over three years. Demographics, comorbid conditions, and operative details were recorded. Postoperative two-week, six-week, six-month, and one-year follow-up occurred. Primary outcomes measures include wound occurrence, QOL parameters using the Short Form-12 health survey, and hernia recurrence. Groups were compared using chi-squared, Fisher's exact, Mann-Whitney U, or t tests as appropriate. Significance was set at P < 0.05. Thirty-five patients underwent hernia repair using ADM: mean age = 58 years, mean body mass index = 34 kg/m2, >50 per cent Centers for Disease Control and Prevention Wound Class II and above, >50 per cent recurrent hernia repair, and 25 per cent current or previous mesh infection. Twenty patients (57%) experienced surgical site occurrences, 15 (43%) wound infections, and 5 (14%) recurrences with a median follow-up of one year. All Short Form-12 QOL indicators improved at 12 months compared with baseline (NS). Outcomes were similar between mesh types. In conclusion, abdominal wall reconstruction for complex hernias using biologic materials is safe but has significant morbidity. Wound complications occur in over half of all patients and are not impacted by ADM type. There is no decrement in QOL one year after hernia repair despite associated morbidity.

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.