Biologic versus Synthetic Mesh Reinforcement: What are the Pros and Cons?

Ibuprofen-loaded bilayer electrospun mesh modulates host response toward promoting full-thickness abdominal wall defect repair

Pro-inflammatory response impairs the constructive repair of abdominal wall defects after mesh implantation. Electrospinning-aid functionalization has the potential to improve the highly orchestrated response by attenuating the over-activation of foreign body reactions. Herein, we combined poly(L-lactic acid-co-caprolactone) (PLLA-CL) with gelatin proportionally via electrospinning, with Ibuprofen (IBU) incorporation to fabricate a bilayer mesh for the repair improvement. The PLLA-CL/gelatin/IBU (PGI) mesh was characterized in vitro and implanted into the rat model with a full-thickness defect for a comprehensive evaluation in comparison to the PLLA-CL/gelatin (PG) and off-the-shelf small intestinal submucosa (SIS) meshes. The bilayer PGI mesh presented a sustained release of IBU over 21 days with degradation in vitro and developed less-intensive intraperitoneal adhesion along with a histologically weaker inflammatory response than the PG mesh after 28 days. It elicited an M2 macrophage-dominant foreign body reaction within the process, leading to a pro-remodeling response similar to the biological SIS mesh, which was superior to the PG mesh. The PGI mesh provided preponderant mechanical supports over the SIS mesh and the native abdominal wall with similar compliance. Collectively, the newly developed mesh advances the intraperitoneal applicability of electrospun meshes by guiding a pro-remodeling response and offers a feasible functionalization approach upon immunomodulation.

In vivo comparison of mesh fixation solutions in open and laparoscopic procedures for inguinal hernia repair: A meta-analysis

Background

Abdominal hernia repair surgeries involve the fixation of a surgical mesh to the abdominal wall with different means such as suture, tacks, and glues. Currently, the most effective mesh fixation system is still debated. This review compares outcomes of mesh fixation in different surgical procedures, aiding surgeons in identifying the optimal technique.

Methods

A meta-analysis was conducted according to PRISMA guidelines. Articles published between January 2003 and January 2023 were searched in electronic databases. Randomized controlled trials (RCTs) comparing mesh fixation with cyanoacrylate-based or fibrin glues with classical fixation techniques (sutures, tacks) in open and laparoscopic procedures were included.

Results

17 RCTs were identified; the cumulative study population included 3919 patients and a total of 3976 inguinal hernias. Cyanoacrylate-based and fibrin glues were used in 1639 different defects, suture and tacks in 1912 defects, self-gripping mesh in 404 cases, and no mesh fixation in 21 defects. Glue fixation resulted in lower early postoperative pain, and chronic pain occurred less frequently. The incidence of hematoma was lower with glue fixation than with mechanical fixation. Recurrence rate, seroma formation, operative and hospitalization time showed no significant differences; but significantly, a higher number of people in the glue group returned to work by 15- and 30-days after surgery when compared to the tacker and suture groups in the same time frame.

Conclusion

Cyanoacrylate and fibrin glue may be effective in reducing early and chronic pain and hematoma incidence without increasing the recurrence rate, the seroma formation, or the operative and hospitalization time.

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.

Ventral hernia repair using bioresorbable poly-4-hydroxybutyrate mesh in clean and contaminated surgical fields: a systematic review and meta-analysis

PURPOSE

Use of biologic or synthetic mesh in hernia repair shifts is based on evolving evidence. Poly-4-hydroxybutyrate (P4HB) biosynthetic mesh is a potential alternative to biologic and synthetic mesh in ventral hernia repair (VHR). This meta-analysis assesses the efficacy of P4HB mesh in clean and contaminated surgical settings.

METHODS

Two authors searched literature on PubMed, reviewing titles and abstracts of all articles to determine inclusion eligibility. Post-operative data were compared via transformation method to convert the proportion of patients with the outcome of interest into a suitable quantity for random-effects synthesis using STATA software.

RESULTS

Initial search yielded 287 citations. Six studies were included and categorized on whether hernia repairs were conducted in clean (CDC class I) or contaminated cases (CDC class II-IV). The pooled proportion of surgical site infection (SSI), surgical site occurrence (SSO), hernia recurrence, total surgical complications, and reoperation were calculated in 391 clean and 81 contaminated cases. For clean vs. contaminated cases, the following pooled proportions were noted: SSI (2% (CI 0-7%) vs 9% (CI 0-025) (p = 0.03), SSO: 14% (CI 5-25%) vs 35% (CI 22-50%) (p = 0.006), hernia recurrence (8% (CI 1-19%) vs 4% (CI 0-12%) (p = 0.769); surgical complications (17% (CI 6-32%) vs 50% (CI 27-72%) (p = 0.009). Reoperation data were available in 298 clean cases across four studies: 5% (CI 0-15%).

CONCLUSIONS

P4HB biosynthetic mesh may be more effective than previously thought, particularly in clean wounds. P4HB may also be superior to biologic mesh when compared to clinical trial data. Further research is necessary for more direct comparison.

Reviewing Outcomes and Complications with the Use of Mesh in Breast Reduction Surgery

INTRODUCTION

Reduction mammoplasty is a common reconstructive and esthetic procedure with variable long-term outcomes regarding breast shape, projection, and nipple-areolar complex. One common complaint is recurrent breast ptosis, which may be mitigated by sufficient support of the inferior pole. This review will look at the effects of mesh in mitigating postoperative ptosis following reduction mammoplasty.

METHODS

A comprehensive review of the literature was performed using the PubMed database. Manuscripts that provided data with respect to the effects of mesh on cosmetic outcomes, patient-reported outcomes, complications, and surveillance were utilized.

RESULTS

Six studies with a total of 634 patients were included in this review. There is limited evidence to support a cosmetic benefit with the use of mesh in reduction mammoplasty patients. While subjective satisfaction was demonstrated in one paper, few others had objective measurements of the impact of mesh. Complications included infection, skin necrosis, and loss of nipple sensation. Mammography was found to not be affected by mesh placement.

DISCUSSION

The use of mesh during reduction mammoplasty is a relatively modern innovation that does not appear to have a significantly different risk profile than that of traditional reduction procedures. There is limited cosmetic value based on currently available data. More objective future analysis is necessary in order to justify the use of mesh in reduction mammoplasty for its claimed cosmetic benefits.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine Ratings, please refer to Table of Contents or online Instructions to Authors www.springer.com/00266.

Maximizing mesh mileage: evaluating the long-term performance of a novel hybrid mesh for ventral hernia repair

PURPOSE

The objective of this study is to evaluate the safety and long-term outcomes of GORE Synecor™ in ventral hernia repair (VHR).

METHODS

This retrospective, single-center case review analyzed outcomes in patients who underwent VHR with Synecor from May 2016 to December 2022. Primary outcomes were hernia recurrence and mesh infection rates. Secondary outcomes were 30-day morbidity, 30-day mortality, 30-day readmission, re-operation, surgical-site infection (SSI) and occurrence (SSO) rates, and occurrences requiring intervention (SSOI).

RESULTS

278 patients were identified. Mean follow-up was 24.1 (0.2-87.1) months. Mean hernia defect size was 63.4 (± 77.2) cm2. Overall hernia recurrence and mesh infection rates were 5.0% and 1.4% respectively. No mesh infections required full explantation. We report the following overall rates: 13.3% 30-day morbidity, 4.7% 30-day readmission, 2.9% re-operation, 7.2% SSI, 6.1% SSO, and 2.9% SSOI. 30-day morbidity was significantly higher in non-clean (42.1% vs 11.2%, p < 0.01), onlay (OL) mesh (37.0% vs preperitoneal (PP) 16.4%, p = 0.05 vs retrorectus (RR) 15.0%, p < 0.05 vs intraperitoneal (IP) 5.2%, p < 0.001), and open cases (23.5% vs 3.1% laparoscopic vs 4.4% robotic, p < 0.01). SSI rates were significantly higher in non-clean (31.6% vs 5.4%, p < 0.001), OL mesh (29.6% vs RR 11.3%, p < 0.05 vs PP 5.5%, p < 0.01 vs IP 0.0%, p < 0.001), and open cases (15.2% vs 0% laparoscopic vs 0% robotic, p < 0.05).

CONCLUSION

Long-term performance of a novel hybrid mesh in VHR demonstrates a low recurrence rate and favorable safety profile in various defect sizes and mesh placement locations.

Definitive Closure Using an Ovine Reinforced Tissue Matrix in Contaminated Penetrating Abdominal Trauma

BACKGROUND Cases involving penetrating abdominal trauma may be complex and often involve damage to multiple organ systems. Synthetic, biologic, and reinforced biologic matrices/reinforced tissue matrices (RBMs/RTMs) are frequently used in hernia repair and other surgical procedures requiring reinforcement, including trauma cases that require abdominal repair. CASE REPORT The first case was a 35-year-old male patient with a stab wound (SW) to the right side of the chest and the abdomen resulting in damage to the diaphragm, epicardium, liver, and duodenum. The second case was a 22-year-old male patient who suffered multiple traumas after an automated trencher accident, including a skull fracture with exposed brain and major lacerations to the shoulder and abdomen causing a large right-flank hernia. In both cases, OviTex® (TELA Bio, Inc., Malvern, PA), a reinforced tissue matrix (RTM), was used to help obtain and maintain abdominal wall closure. We also present an institutional economic analysis using data from the author's institution with average case cost and future projections for procedure volume and product usage volume through 2021. CONCLUSIONS We report favorable outcomes in a series of patients with contaminated (CDC Wound Class III) surgical fields who underwent abdominal wall closure and reinforcement with OviTex RTM. Our work adds to the growing body of literature suggesting that reinforced biologics offer a potential alternative to biological meshes in the setting of a contaminated surgical field. Additionally, in comparison to other commonly available biologic matrices, use of OviTex RTM may be a cost-effective option to achieve abdominal wall closure even in complex cases.

Wound healing and hernia after abdominal aortic aneurysm repair - Onlay self-gripping polyester mesh reinforcement compared with small bite sutured closure

BACKGROUND

Prophylactic mesh implantation following open surgical repair of abdominal aortic aneurysm is a debatable subject.

OBJECTIVE

To assess the efficacy of a self-gripping polyester mesh used in on-lay technique to prevent incisional hernia after open abdominal aortic aneurysm repair.

METHODS

We retrospectively reviewed the records of 495 patients who underwent aortic surgery between May 2017 and May 2021. Patients included in the study underwent open surgical repair for infrarenal abdominal aortic aneurysm (AAA) with closure of the abdominal wall with either small bite suture technique or prophylactic mesh reinforcement. Primary endpoint of the study was the occurrence of incisional hernia during a two-year follow-up period. Secondary endpoints were mesh-related complications.

RESULTS

Mesh implantation with the on-lay technique was successful in all cases. No patient in the mesh group developed an incisional hernia during the 24-month follow-up period. Two patients in the non-mesh group developed a symptomatic incisional hernia during the follow-up period at 6 months. Three cases of post-operative access site complications were observed in the mesh group.

CONCLUSIONS

Application of a self-gripping polyester mesh using the on-lay technique demonstrates acceptable early-durability after open surgical repair of abdominal aortic aneurysms. However, it appears to be associated with a number of post-operative access site complications.

Reconstructive Strategies in Pediatric Patients after Oncological Chest Wall Resection: A Systematic Review

An appropriate reconstruction strategy after surgical resection of chest wall tumors in children is important to optimize outcomes, but there is no consensus on the ideal approach. The aim of this study was to provide an up-to-date systematic review of the literature for different reconstruction strategies for chest wall defects in patients less than 18 years old. A systematic literature search of the complete available literature was performed and results were analyzed. A total of 22 articles were included in the analysis, which described a total of 130 chest wall reconstructions. All were retrospective analyses, including eight case reports. Reconstructive options were divided into primary closure (n = 21 [16.2%]), use of nonautologous materials (n = 83 [63.8%]), autologous tissue repair (n = 2 [1.5%]), or a combination of the latter two (n = 24 [18.5%]). Quality of evidence was poor, and the results mostly heterogeneous. Reconstruction of chest wall defects can be divided into four major categories, with each category including its own advantages and disadvantages. There is a need for higher quality evidence and guidelines, to be able to report uniformly on treatment outcomes and assess the appropriate reconstruction strategy.

Cysteine-Silver-Polymer Systems for the Preparation of Hydrogels and Films with Potential Applications in Regenerative Medicine

Herein, the problem concerning the poorer mechanical properties of gels based on low molecular weight gelators (LMWGs)-L-cysteine and silver nitrate-was solved by the addition of various polymers-polyvinyl alcohol (PVA), polyvinyl pyrrolidone (PVP) and polyethylene glycol (PEG)-to the initial cysteine-silver sol (CSS). The physicochemical methods of analysis-viscosimetry, UV spectroscopy, DLS, and SEM-identified that cysteine-silver hydrogels (CSG) based on PVA possess the best rheological properties and porous microstructure (the average pore size is 2-10 µm) compared to gels without the polymer or with PVP or PEG. Such gels are able to form cysteine-silver cryogels (CSC) and then porous cysteine-silver films (CSF) with an average pore size of 10-20 µm and good mechanical, swelling, and adhesion to skin characteristics as long as the structure of CSS particles remains stable. In vitro experiments have shown that hydrogels are non-toxic to normal human fibroblast cells. The obtained materials could potentially be applied to regenerative medicine.

Bubble plastic use in rats hernioplasty: Uso do plástico bolha em hernioplastias de ratos

Purpose

Despite the high frequency of hernioplasties worldwide, their complications and recurrences are still a challenge to be overcome. The search for prostheses that aim to promote the correction of hernia defects has been a challenge. For this purpose, the materials used in hernioplasties must be biocompatible, promote the formation of little or no peritoneal adhesion, possess compatible texture and flexibility, providing the necessary resistance to protect the viscera and allow the movement of the abdomen.

Methods

The aim of the present study was to evaluate the effectiveness of bubble plastic (low density polyethylene, LDPE) as a material for the correction of hernia in the abdominal wall. For this, twenty male rats (Rattus norvegicus, Wistar variety) were used and divided into four groups of five animals. The animals were evaluated at 7, 15, 30 and 90 days after surgery according to clinical, thermographic and morphological parameters (macroscopic and microscopic).

Results

The results showed that the bubble plastic induced inflammatory reaction in the initial period (7 day), followed by a reduction (30 day) to increase considerably at 90 days after the operation.

Conclusion

So, bubble plastic can be used for temporary implants (up to 30 days).

Comparing the Outcomes and Complication Rates of Biologic vs Synthetic Meshes in Implant-Based Breast Reconstruction: A Systematic Review

OBJECTIVE

This systematic review evaluates all published studies comparing biologic and synthetic meshes in implant-based breast reconstruction (IBBR), to determine which category of mesh produces the most favorable outcomes.

SUMMARY BACKGROUND DATA

Breast cancer is the most common cancer in women globally. Implant-based breast reconstruction is currently the most popular method of postmastectomy reconstruction, and recently, the use of surgical mesh in IBBR has become commonplace. Although there is a long-standing belief among surgeons that biologic mesh is superior to synthetic mesh in terms of surgical complications and patient outcomes, few studies exist to support this claim.

METHODS

A systematic search of the EMBASE, PubMed, and Cochrane databases was performed in January 2022. Primary literature studies comparing biologic and synthetic meshes within the same experimental framework were included. Study quality and bias were assessed using the validated Methodological Index for Non-Randomized Studies criteria.

RESULTS

After duplicate removal, 109 publications were reviewed, with 12 meeting the predetermined inclusion criteria. Outcomes included common surgical complications, histological analysis, interactions with oncologic therapies, quality of life measures, and esthetic outcomes. Across all 12 studies, synthetic meshes were rated as at least equivalent to biologic meshes for every reported outcome. On average, the studies in this review tended to have moderate Methodological Index for Non-Randomized Studies scores.

CONCLUSION

This systematic review offers the first comprehensive evaluation of all publications comparing biologic and synthetic meshes in IBBR. The consistent finding that synthetic meshes are at least equivalent to biologic meshes across a range of clinical outcomes offers a compelling argument in favor of prioritizing the use of synthetic meshes in IBBR.

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.

Does bioabsorbable mesh reduce hiatal hernia recurrence rates? A meta-analysis

INTRODUCTION

The use of bioabsorbable mesh at the hiatus is controversial. Long-term data are scant. We evaluated the world literature and performed a meta-analysis to determine if these meshes were effective in reducing recurrence.

METHODS

A literature search was performed using PubMed, MEDLINE, and ClinicalKey. We evaluated articles reporting on both Bio-A™ (polyglycolic acid:trimethylene carbonate-PGA:TMC) and Phasix™ (poly-4-hydroxybutyrate-P4HB) used at the hiatus. The DerSimonian-Laird random effects model was used to estimate the overall pooled treatment effect along with a 95% confidence interval (CI). Similar analysis was conducted to compare the clinical outcomes, i.e., recurrence rate, mean surgical time, mean hospital stays and mean follow-up duration between non-Mesh and Mesh group. The I² statistic was computed to assess the heterogeneity in effect sizes across the studies.

RESULTS

A total of 21 studies (12 mesh studies with 963 subjects and 9 non-mesh studies with 617 subjects) were included to conduct the meta-analysis. There was one article reporting outcomes on P4HB mesh (73 subjects) and 11 on PGA:TMC mesh (890 subjects). The bioabsorbable mesh group had a significantly lower recurrence rate compared to the non-mesh group (8% vs. 18%; 95%CI 0.08-0.17), pooled p-value < 0.0001. Surgery time was shorter in the mesh group compared to the non-mesh group (136.4 min vs. 150 min) but not statistically significant (p = 0.54). There tended to be a more extended follow-up period after surgery in the non-mesh group compared to the mesh group (27 vs. 25.8 months, range 10.8-54 months); but not statistically significant (ES: 27.4; 95%CI 21.6-33.3; p = 0.92).

CONCLUSIONS

Hiatal hernia repair with bioabsorbable mesh is more effective at reducing hernia recurrence rate in the mid-term than simple suture cruroplasty. Further studies investigating the long-term outcomes and P4HB mesh are needed.

Fabrication of Mechanically Enhanced, Suturable, Fibrous Hydrogel Membranes

Poly(vinyl-alcohol) hydrogels have already been successfully utilised as drug carrier systems and tissue engineering scaffolds. However, lacking mechanical strength and suturability hinders any prospects for clinical and surgical applications. The objective of this work was to fabricate mechanically robust PVA membranes, which could also withstand surgical manipulation and suturing. Electrospun membranes and control hydrogels were produced with 61 kDa PVA. Using a high-speed rotating cylindrical collector, we achieved fibre alignment (fibre diameter: 300 ± 50 nm). Subsequently, we created multilayered samples with different orientations to achieve multidirectional reinforcement. Finally, utilising glutaraldehyde as a cross-linker, we created insoluble fibrous-hydrogel membranes. Mechanical studies were performed, confirming a fourfold increase in the specific loading capacities (from 0.21 to 0.84 Nm²/g) in the case of the monolayer samples. The multilayered membranes exhibited increased resistance from both horizontal and vertical directions, which varies according to the specific arrangement. Finally, the cross-linked fibrous hydrogel samples not only exhibited specific loading capacities significantly higher than their counterpart bulk hydrogels but successfully withstood suturing. Although cross-linking optimisation and animal experiments are required, these membranes have great prospects as alternatives to current surgical meshes, while the methodology could also be applied in other systems as well.

Robotic Ventral Transabdominal Preperitoneal Repair of Uncomplicated Spigelian Hernia

Spigelian hernias are rare herniations through the Spigelian fascia, with an incidence rate of 0.12-2.0% of all hernias. Diagnosis may be difficult due to a potential lack of symptoms until complications arise. Therefore, imaging with either ultrasound or CT with oral contrast is recommended to confirm the diagnosis if a Spigelian hernia is suspected. Once the diagnosis has been established, it is essential that operative repair be performed as soon as possible because 24% of Spigelian hernias become incarcerated, and 27% of Spigelian hernias lead to strangulation. Management options include open surgery, laparoscopic surgery, and robotic surgery. This case report discusses the management of a 47-year-old man with an uncomplicated Spigelian hernia that was repaired with the robotic ventral transabdominal preperitoneal repair technique.

NIR-II live imaging study on the degradation pattern of collagen in the mouse model

The degradation of collagen in different body parts is a critical point for designing collagen-based biomedical products. Here, three kinds of collagens labeled by second near-infrared (NIR-II) quantum dots (QDs), including collagen with low crosslinking degree (LC), middle crosslinking degree (MC) and high crosslinking degree (HC), were injected into the subcutaneous tissue, muscle and joints of the mouse model, respectively, in order to investigate the in vivo degradation pattern of collagen by NIR-II live imaging. The results of NIR-II imaging indicated that all tested collagens could be fully degraded after 35 days in the subcutaneous tissue, muscle and joints of the mouse model. However, the average degradation rate of subcutaneous tissue (k = 0.13) and muscle (k = 0.23) was slower than that of the joints (shoulder: k = 0.42, knee: k = 0.55). Specifically, the degradation rate of HC (k = 0.13) was slower than LC (k = 0.30) in muscle, while HC showed the fastest degradation rate in the shoulder and knee joints. In summary, NIR-II imaging could precisely identify the in vivo degradation rate of collagen. Moreover, the degradation rate of collagen was more closely related to the implanted body parts rather than the crosslinking degree of collagen, which was slower in the subcutaneous tissue and muscle compared to the joints in the mouse model.

Outcomes of Biosynthetic and Synthetic Mesh in Ventral Hernia Repair

The introduction of mesh for reinforcement of ventral hernia repair (VHR) led to a significant reduction in hernia recurrence rates. However, it remains controversial whether synthetic or biologic mesh leads to superior outcomes. Recently, hybrid mesh consisting of reinforced biosynthetic ovine rumen (RBOR) has been developed and aims to combine the advantages of biologic and synthetic mesh; however, outcomes after VHR with RBOR have not yet been compared with the standard of care.

Methods

We performed a retrospective analysis on 109 patients, who underwent VHR with RBOR (n = 50) or synthetic polypropylene mesh (n = 59). Demographic characteristics, comorbidities, postoperative complications, and recurrence rates were analyzed and compared between the groups. Multivariate logistic regression models were fit to assess associations of mesh type with overall complications and surgical site occurrence (SSO).

Results

Patients who underwent VHR with RBOR were older (mean age 63.7 versus 58.8 years, P = 0.02) and had a higher rate of renal disease (28.0 versus 10.2%, P = 0.01) compared with patients with synthetic mesh. Despite an unfavorable risk profile, patients with RBOR had lower rates of SSO (16.0 versus 30.5%, P = 0.12) and similar hernia recurrence rates (4.0 versus 6.78%, P = 0.68) compared with patients with synthetic mesh. The use of synthetic mesh was significantly associated with higher odds for overall complications (3.78, P < 0.05) and SSO (3.87, P < 0.05).

Conclusion

Compared with synthetic polypropylene mesh, the use of RBOR for VHR mitigates SSO while maintaining low hernia recurrence rates at 30-month follow-up.

Establishing Peer Consensus About the Use of Long-Term Biosynthetic Absorbable Mesh for Hernia (Grades 2-3) as the Standard of Care

BACKGROUND

Standard synthetic and biologic meshes, often used in hernia repair, have commonly been used and each have their strengths but associated drawbacks. Long-term biosynthetic absorbable (LTBA) mesh has been developed to combine the strengths of synthetic and biologic meshes without the associated weaknesses. As a newer type of mesh, the supporting evidence base is still growing, and their optimum use has yet to be defined. This consensus was initiated to provide insight into those situations where a LTBA might be considered the Standard of Care in ventral hernia repair grades 2-3 (original classification, 2010) of the Ventral Hernia Working Group.

METHODS

A steering group of expert surgeons identified 35 statements, based around the evidence supporting LTBA, surgical technique, patients type most suitable for LTBA, risk-benefit of LTBA, patient and surgeon considerations, LTBA value. Surgeons involved in hernia repair received an online survey to assess consensus with these statements. Consensus was defined as high if ≥ 70% and very high if ≥ 90% of respondents agreed. Statements that had not achieved consensus agreement were revised and these were then issued for a subsequent round. Finally, 34 statements were included.

RESULTS

Two hundred fifty-five surgeons were involved. Fourteen statements (41%) achieved very high consensus, 24 achieved consensuses (≥ 70-< 90%), whilst one (3%) just failed to achieve consensus with an agreement score of 69%.

CONCLUSIONS

Expert consensus opinion about the use of LTBA for hernia (Grades 2-3) as the Standard of Care was achieved. Based on the consensus scores, the steering group derived eleven keys.

The sternum reconstruction: Present and future perspectives

Sternectomy is a procedure mainly used for removing tumor masses infiltrating the sternum or treating infections. Moreover, the removal of the sternum involves the additional challenge of performing a functional reconstruction. Fortunately, various approaches have been proposed for improving the operation and outcome of reconstruction, including allograft transplantation, using novel materials, and developing innovative surgical approaches, which promise to enhance the quality of life for the patient. This review will highlight the surgical approaches to sternum reconstruction and the new perspectives in the current literature.

Extensive orbital inflammation in an anophthalmic socket: is the Bioceramic implant a bystander or a participant?

Purpose

Porous orbital implants are commonly used materials following enucleation or evisceration. Implant-associated inflammation is a rare but serious complication which may necessitate explantation.

Observations

We report a case of a patient who developed extensive orbital inflammation six months after implantation of a vicryl (polyglactin 910) mesh-wrapped Bioceramic (aluminum oxide) spherical implant. An orbital biopsy demonstrated an extensive fibroinflammatory reaction with multinucleated giant cells. Removal of the implant resulted in complete resolution of symptoms.

Conclusions and importance

We surmise that the Bioceramic implant played a significant contributory role in this patient's orbital inflammation, a complication which has not been described previously.

A biomimetic multilayered polymeric material designed for heart valve repair and replacement

Materials currently used to repair or replace a heart valve are not durable. Their limited durability related to structural degeneration or thrombus formation is attributed to their inadequate mechanical properties and biocompatibility profiles. Our hypothesis is that a biostable material that mimics the structure, mechanical and biological properties of native tissue will improve the durability of these leaflets substitutes and in fine improve the patient outcome. Here, we report the development, optimization, and testing of a biomimetic, multilayered material (BMM), designed to replicate the native valve leaflets. Polycarbonate urethane and polycaprolactone have been processed as film, foam, and aligned fibers to replicate the leaflet's architecture and anisotropy, through solution casting, lyophilization, and electrospinning. Compared to the commercialized materials, our BMMs exhibited an anisotropic behavior and a closer mechanical performance to the aortic leaflets. The material exhibited superior biostability in an accelerated oxidization environment. It also displayed better resistance to protein adsorption and calcification in vitro and in vivo. These results will pave the way for a new class of advanced synthetic material with long-term durability for surgical valve repair or replacement.

Synthetic versus Biological Patches for CDH: A Comparison of Recurrence Rates and Adverse Events, Systematic Review, and Meta-Analysis

OBJECTIVE

 Our systematic review aims to compare recurrence rates and complications of biological versus synthetic patches for the repair of congenital diaphragmatic herniae.

METHODS

 Studies from January 1, 1980 to April 25, 2020, with patients under the age of 16 years and with a minimum 6-month follow-up, were included from MEDLINE, Embase, and Cochrane databases. Funnel plots for recurrence rates were constructed for biological and synthetic patches. Subgroup analysis was performed for recurrence rate at the 1-year time-point and data were gathered on individual adverse events from relevant studies.

RESULTS

 A total of 47 studies with 986 patients (226 biological, 760 synthetic) were included. Funnel plot analysis determined overall recurrence rates of 16.7% for synthetic and 30.3% for biological patches. Subgroup analysis of 493 and 146 patients with synthetic and biological patches, respectively, showed recurrence rates of 9.9 and 26%, respectively.The most commonly used patch types-PTFE (polytetrafluoroethylene) and SIS (small intestinal submucosa)-had 11.5 and 33.3% recurrence, respectively. Adhesive bowel obstruction rates ranged from 4 to 29% in studies that systematically reported it for synthetic, and 7 to 35% for biological patches. Gastroesophageal reflux rates ranged from 25 to 48% in studies that systematically reported it for synthetic, and 21 to 42% for biological patches. Pectus deformity rates were reported as high as 80% for synthetic patches.

CONCLUSION

 Biological patches appear to have higher recurrence rates than synthetic patches, while skeletal deformities are associated more commonly with synthetic patches. Results of biological patches are mainly using SIS and this may overestimate complications of current superior biological patches.

Abdominal hernia mesh repair in patients with inflammatory bowel disease: A systematic review

Background

Postoperative hernia-repair complications are frequent in patients with inflammatory bowel disease (IBD). This fact challenges surgeons’ decision about hernia mesh management in these patients. Therefore, we systematically reviewed the hernia mesh repair in IBD patients with emphasis on risk factors for postoperative complications.

Method

A systematic review was done in compliance with the PRISMA guidelines. A search was carried out on PubMed and ScienceDirect databases. English language articles published from inception to October 2021 were included in this study. MERSQI scores were applied along with evidence grades in agreement with GRADE’s recommendations. The research protocol was registered with PROSPERO (CRD42021247185).

Results

The present systematic search resulted in 11,243 citations with a final inclusion of 10 citations. One paper reached high and 4 moderate quality. Patients with IBD exhibit about 27% recurrence after hernia repair. Risk factors for overall abdominal septic morbidity in Crohn’s disease comprised enteroprosthetic fistula, mesh withdrawals, surgery duration, malnutrition biological mesh, and gastrointestinal concomitant procedure.

Conclusion

Patients with IBD were subject, more so than controls to postoperative complications and hernia recurrence. The use of a diversity of mesh types, a variety of position techniques, and several surgical choices in the citations left room for less explicit and more implicit inferences as regards best surgical option for hernia repair in patients with IBD.

Biodegradation of poly(L-lactic acid) and poly(ε-caprolactone) patches by human amniotic fluid in an in-vitro simulated fetal environment

Open spina bifida or myelomeningocele (MMC) is a devastating neurologic congenital defect characterized by primary failure of neural tube closure of the spinal column during the embryologic period. Cerebrospinal fluid leak caused by the MMC spinal defect in the developing fetus can result in a constellation of encephalic anomalies that include hindbrain herniation and hydrocephalus. The exposure of extruded spinal cord to amniotic fluid also poses a significant risk for inducing partial or complete paralysis of the body parts beneath the spinal aperture by progressive spinal cord damage in-utero. A randomized trial demonstrated that prenatal repair by fetal surgery, sometimes using patches, to cover the exposed spinal cord with a watertight barrier is effective in reducing the postnatal neurologic morbidity as evidenced by decreased incidence and severity of postnatal hydrocephalus and the reduced need for ventricular-peritoneal shunting. Currently, the use of inert or collagen-based patches are associated with high costs and inadequate structural properties. Specifically, the inert patches do not degrade after implantation, causing the need for a post-natal removal surgery associated with trauma for the newborn. Our present study is aimed towards in-vitro degradation studies of a newly designed patch, which potentially can serve as a superior alternative to existing patches for MMC repair. This novel patch was fabricated by blending poly(l-lactic acid) and poly(ε-caprolactone). The 16-week degradation study in amniotic fluid was focused on tracking changes in crystallinity and mechanical properties. An additional set of designed patches was exposed to phosphate-buffered saline (PBS), as a time-paired control. Crystallinity studies indicate the progress of hydrolytic degradation of the patch in both media, with a preference to bulk erosion in phosphate buffered saline and surface erosion in amniotic fluid. Mechanical testing results establish that patch integrity is not compromised up to 16 weeks of exposure either to body fluids analog (PBS) or to amniotic fluid.

Low Concentrated Fractionalized Nanofibers as Suitable Fillers for Optimization of Structural–Functional Parameters of Dead Space Gel Implants after Rectal Extirpation

Dead space after rectal resection in colorectal surgery is an area with a high risk of complications. In this study, our goal was to develop a novel 3D implant based on composite hydrogels enriched with fractionalized nanofibers. We employed, as a novel approach in abdominal surgery, the application of agarose gels functionalized with fractionalized nanofibers on pieces dozens of microns large with a well-preserved nano-substructure. This retained excellent cell accommodation and proliferation, while nanofiber structures in separated islets allowed cells a free migration throughout the gel. We found these low-concentrated fractionalized nanofibers to be a good tool for structural and biomechanical optimization of the 3D hydrogel implants. In addition, this nano-structuralized system can serve as a convenient drug delivery system for a controlled release of encapsulated bioactive substances from the nanofiber core. Thus, we present novel 3D nanofiber-based gels for controlled release, with a possibility to modify both their biomechanical properties and drug release intended for 3D lesions healing after a rectal extirpation, hysterectomy, or pelvic exenteration.

A case of disintegrated Strattice™ 4 years after immediate breast reconstruction

Acellular dermal matrices (ADMs) are used frequently in immediate breast reconstruction (IBR). In general, the porcine-derived ADM Strattice™ has been reported with good outcomes and low complication rates. Nonetheless, we report here a case of a 42-year-old, otherwise healthy woman with a history of uncomplicated bilateral prophylactic nipple-sparing mastectomies and subpectoral IBRs performed using Strattice™ and Mentor^® CPG™, who was referred to the Department of Plastic Surgery 4 years after this surgery due to changed appearance of her breast implants. Both CPG implants were found intact and there were no signs of infection but, surprisingly, the Strattice™ had completely disintegrated on both sides. Examinations did not show any malignancies, and at 1-year clinical follow-up, the patient had no signs of relapse. Thus, we suggest that the Strattice™ had disintegrated as a late aseptic foreign body reaction and emphasise the importance of surgeons being aware of this late and rare complication.

Prophylactic Mesh for Prevention of Parastomal Hernia Following End Colostomy: an Updated Systematic Review and Meta-Analysis of Randomized Controlled Trials

OBJECTIVE

To evaluate the efficacy of prophylactic mesh placement during end colostomy formation at reducing rates of parastomal hernia using the most recently available data.

BACKGROUND

Systematic reviews and meta-analyses of randomized controlled trials (RCTs) have uniformly concluded that the use of prophylactic surgical mesh when fashioning an end colostomy reduces the risk of parastomal hernia. However, recent RCTs have failed to corroborate these findings. This study was designed to provide an updated systematic review and meta-analysis evaluating the efficacy of prophylactic mesh placement during end colostomy formation.

METHODS

A search of Medline, EMBASE, and CENTRAL was performed. Articles were included if they were RCTs that compared the use of prophylactic mesh to no prophylactic mesh during construction of an end colostomy following colorectal resection for benign or malignant disease. The primary outcome was parastomal hernia rate. A pairwise meta-analysis was performed using inverse variance random effects.

RESULTS

From 1,089 citations, 12 RCTs with 581 patients having prophylactic mesh placement and 671 patients not having prophylactic mesh placement met inclusion criteria. Incidence of parastomal hernia was significantly reduced in patients receiving prophylactic mesh (OR 0.60, 95% CI 0.46 to 0.80, p = 0.0003, I² = 74%). Results were no longer significantly different when only studies conducted in the last 5 years were analyzed (p = 0.10). There was no significant difference in postoperative morbidity, postoperative mortality, colostomy-specific morbidity, or length of stay between groups.

CONCLUSIONS

There remains a significant reduction in the risk of parastomal hernia with the use of prophylactic mesh at the time of end colostomy formation, despite recent evidence suggesting no difference. Further contemporary trials with the application of modern surgical technology are required.

Design, mechanical and degradation requirements of biodegradable metal mesh for pelvic floor reconstruction

Pelvic organ prolapse (POP) is the herniation of surrounding tissue and organs into the vagina and or rectum, and is a result of weakening of pelvic floor muscles, connective tissue,...

Systematic review and meta-analysis of risk factors for Mesh infection following Abdominal Wall Hernia Repair Surgery

BACKGROUND

Surgical Mesh Infection (SMI) after Abdominal Wall Hernia Repair (AWHR) represents a catastrophic complication. We performed a systematic review and meta-analysis to analyze the risk factors for SMI in the context of AWHR.

METHODS

PubMed, Embase, Scielo, and LILACS were searched without language or time restrictions from inception until June 2021. Articles evaluating the association between demographic, clinical, laboratory and surgical characteristics with SMI in AWHR were included.

RESULTS

23 studies were evaluated, comprising a total of 118,790 patients (98% males; mean age 56.5 years) with a mesh infection pooled prevalence of 4%. Significant risk factors for SMI were type 2 diabetes mellitus, obesity, smoking history, steroids use, ASA III/IV, laparotomy vs laparoscopy, emergency surgery, duration of surgery and onlay mesh position vs sublay. The quality of evidence was regarded as very low-moderate.

CONCLUSION

Several factors, highlighting sociodemographic characteristics, comorbidities, and the clinical scenario, may increase the risk of developing mesh infections in AWHR. The recognition and mitigation of these may significantly reduce mesh infection rates in this context.

New Insights into the Application of 3D-Printing Technology in Hernia Repair

Abdominal hernia repair using prosthetic materials is among the surgical interventions most widely performed worldwide. These materials, or meshes, are implanted to close the hernial defect, reinforcing the abdominal muscles and reestablishing mechanical functionality of the wall. Meshes for hernia repair are made of synthetic or biological materials exhibiting multiple shapes and configurations. Despite the myriad of devices currently marketed, the search for the ideal mesh continues as, thus far, no device offers optimal tissue repair and restored mechanical performance while minimizing postoperative complications. Additive manufacturing, or 3D-printing, has great potential for biomedical applications. Over the years, different biomaterials with advanced features have been successfully manufactured via 3D-printing for the repair of hard and soft tissues. This technological improvement is of high clinical relevance and paves the way to produce next-generation devices tailored to suit each individual patient. This review focuses on the state of the art and applications of 3D-printing technology for the manufacture of synthetic meshes. We highlight the latest approaches aimed at developing improved bioactive materials (e.g., optimizing antibacterial performance, drug release, or device opacity for contrast imaging). Challenges, limitations, and future perspectives are discussed, offering a comprehensive scenario for the applicability of 3D-printing in hernia repair.

A Prospective, Single Arm, Multi-Center Study Evaluating the Clinical Outcomes of Ventral Hernias Treated with OviTex® 1S Permanent Reinforced Tissue Matrix: The BRAVO Study 12-Month Analysis

BACKGROUND

Conflicting results from previous studies have led to dissent over whether surgical mesh is safe and effective in ventral hernia repair. A newer class of mesh known as a reinforced tissue matrix, combining a biologic scaffold and minimal polymer reinforcement, offers promise in reducing inflammatory response and increasing abdominal wall support. This study sought to assess the clinical utility of a reinforced tissue matrix (OviTex) in ventral hernia repair 12 months after implantation.

METHODS

This is a prospective, single-arm, multi-center study to evaluate the clinical performance of OviTex^® 1S Permanent (OviTex) in the repair of primary or recurrent ventral hernias (VH) in consecutive patients (ClinicalTrials.gov/NCT03074474). The rate of surgical site occurrences (SSOs) was evaluated 90 days post-surgery as the primary endpoint. Hernia recurrence and the incidence of postoperative events were evaluated between three and 12 months as secondary endpoints. The incidence of other complications and patient-reported outcomes were also recorded.

RESULTS

Ninety-two (92) patients were enrolled in the study, of whom seventy-six (76) reached the 12-month follow-up. All patients were at least 18 years of age with a BMI of <40 kg/m². Hernia defects were <20 × 20 cm, classified as class I-III according to the CDC wound classification system. Of the 76 patients who reached 12-month follow-up, twenty-six (34%) had previous VH repairs and thirteen (17%) had previous surgical infection. Sixty (79%) had factors known to increase the risk of recurrence. Twenty patients (26%) experienced SSOs, with ten (13%) requiring procedural intervention. Two of the 75 patients (2.7%) experienced a recurrence.

CONCLUSIONS

The low rate of hernia recurrence and SSOs requiring intervention illustrates the potential that reinforced tissue matrices, and OviTex 1S, in particular, have to improve outcomes in VH repairs. Follow-up to 24 months is ongoing.

Symptomatic hernia of the thigh musculature requiring reconstruction: A rare late presenting sequela after fascial release for compartment syndrome

Acute compartment syndrome (ACS) of the lower extremity is a surgical emergency, often secondary to severe crush injury, and requires immediate fascial release. In treatment of ACS, the underlying fascia is left unrepaired and the subsequent fascial defect does not generally cause negative consequences. Here, we present a 24-year-old man who developed symptomatic muscle herniation 3-years after undergoing fascial release secondary to ACS of the anterior thigh. Given the size of the defect, reconstruction was performed using Acellular Dermal Matrix (ADM). The patient did well, with no complications 6 months postoperatively. Symptomatic muscle herniation following fasciotomy can be treated with hernia reduction and fascial repair. When primary closure is not possible, Acelluar Dermal Matrix (ADM) is an option for successful fascial reconstruction.

Complex abdominal wall reconstruction after massive resection due to neoplastic invasion: a case report

Complex reconstructions of the abdominal wall, necessary after resection of neoplasms, infection or trauma, are a challenge for the surgical team. Although ovarian carcinoma is commonly presented with peritoneal carcinomatosis and invasion of adjacent organs, it rarely can invade the abdominal wall. Invasion of the abdominal wall was documented on ultrasound and abdominal computed tomography. Surgery was discussed and performed in a multidisciplinary team and consisted of wide en bloc excision and reconstruction with open intraperitoneal onlay mesh with inorganic polypropylene-coated mesh (Bard/BD Sepramesh), a midweight macroporous mesh and abdominoplasty. Postoperative course was uneventful and the patient showed good evolution 1 year after the procedure. Our report highlights the main objectives in complex reconstructions, the importance of a multidisciplinary team and discusses the characteristics that the mesh must have in order to achieve the desired goal.

Slowly resorbable biosynthetic mesh: 2-year results in VHWG grade 3 hernia repair

Introduction

Information on the long-term performance of biosynthetic meshes is scarce. This study analyses the performance of biosynthetic mesh (Phasix™) over 24 months.

Methods

A prospective, international European multi-center trial is described. Adult patients with a Ventral Hernia Working Group (VHWG) grade 3 incisional hernia larger than 10 cm², scheduled for elective repair, were included. Biosynthetic mesh was placed in sublay position. Short-term outcomes included 3-month surgical site occurrences (SSO), and long-term outcomes comprised hernia recurrence, reoperation, and quality of life assessments until 24 months.

Results

Eighty-four patients were treated with biosynthetic mesh. Twenty-two patients (26.2%) developed 34 SSOs, of which 32 occurred within 3 months (primary endpoint). Eight patients (11.0%) developed a hernia recurrence. In 13 patients (15.5%), 14 reoperations took place, of which 6 were performed for hernia recurrence (42.9%), 3 for mesh infection (21.4%), and in 7 of which the mesh was explanted (50%). Compared to baseline, quality of life outcomes showed no significant difference after 24 months. Despite theoretical resorption, 10.7% of patients reported presence of mesh sensation in daily life 24 months after surgery.

Conclusion

After 2 years of follow-up, hernia repair with biosynthetic mesh shows manageable SSO rates and favorable recurrence rates in VHWG grade 3 patients. No statistically significant improvement in quality of life or reduction of pain was observed. Few patients report lasting presence of mesh sensation. Results of biosynthetic mesh after longer periods of follow-up on recurrences and remodeling will provide further valuable information to make clear recommendations.

Trial registration

Registered on clinicaltrials.gov (NCT02720042), March 25, 2016.

The evaluation of functional small intestinal submucosa for abdominal wall defect repair in a rat model: Potent effect of sequential release of VEGF and TGF-β1 on host integration

Ineffective vessel penetration and extracellular matrix (ECM) remodeling are responsible for the failure of porcine small intestinal submucosa (SIS)-repaired abdominal wall defects. Combined growth factors could be used as directing signals in a nature-mimicking strategy to improve this repair through mesh functionalization. In this work, vascular endothelial growth factor (VEGF) and transforming growth factor β1 (TGF-β1) were incorporated into a silk fibroin membrane via coaxial aqueous electrospinning to exploit their benefits of biological interactions. The membrane was sandwiched into the SIS bilayer as a functional mesh to repair partial-thickness defects in a rat model. Membrane characterization demonstrated that the core-shell structure ensured the independent distribution and sequential release of two regulators and protection of their bioactivities, which were confirmed by cell viability and protein expression. The mesh was further assessed to facilitate vasculature formation and collagen secretion in vitro, and exhibited better host integration than VEGF- or TGF-β1-containing mesh and developed reinforced mechanical properties compared with the VEGF-containing mesh after 28 days in vivo. Determination of the underlying biological interactions revealed that rapid VEGF release promotes angiogenesis and collagen secretion but initially potentiates the inflammatory response. Sustained TGF-β1 release at relatively low concentrations promoted VEGF for vessel permeation and maturation and steadily induced ECM remodeling under milder foreign body reactions. The functionalization of SIS improves repair by sufficient integration with timely remodeling and helps elucidate the related regulatory interactions.

In vivo Analysis of the Resistance of the Meshes to Escherichia coli Infection

Background: The mesh infection is mostly related to the gram-negative bacteria, such as Escherichia coli (E. coli) for emergency surgery of incarcerated hernia. However, few study investigated the effects of E. coli concentration, mesh materials and antibiotic prophylaxis on mesh infection after hernioplasty. The aim of this study was to evaluate the bacterial resistance to E. coli for three different materials of mesh, and to measure the minimum E. coli concentration for mesh infection with and without antibiotic prophylaxis in a rat model.

Methods: Three types of mesh (polytetrafluoroethylene, polypropylene, and biologic meshes) were used in the repair of an acute ventral hernia rat model in the setting of different concentrations of E. coli loads and antibiotics. At the 8th day after surgery, mesh samples were sent for microbiologic and histologic analyses.

Results: The positive rates of bacterial culture increased with E. coli concentration. The biologic mesh showed better bacterial resistance compared to polytetrafluoroethylene mesh and polypropylene mesh when the concentration of E. coli ranges from 10⁶ CFU/ml to 10⁸ CFU/ml (P = 0.002 and P = 0.029, respectively). Prophylactical ceftriaxone treatment could not decrease the colonization rate of E. coli at 10⁶ CFU/ml or 10⁸ CFU/ml in each group (P > 0.05). The scores of neovascularization in polypropylene mesh and biologic mesh were similar, which was higher than that of polytetrafluoroethylene mesh (P < 0.05). Compared with other meshes, biologic mesh showed better tolerance to 10⁶ CFU/ml E. coli with respect to inflammation, depth of inflammation, neovascularization, cellular repopulation and foreign body giant cells.

Conclusion: The biologic mesh had better E. coli resistance compared to polytetrafluoroethylene mesh and polypropylene mesh when the E. coli concentration is higher than 10⁶ CFU/ml in rats. Antibiotic prophylaxis was useful when the contamination was not particularly severe.

A Polymer-Biologic Hybrid Hernia Construct: Review of Data and Early Experiences

Surgical mesh reinforcement of the human abdominal wall has been found to reduce the chance of recurrence in hernia repairs. While traditionally polymer meshes have been used in hernia repair, alternative mesh options have been engineered to prevent the inflammatory foreign body response invoked by polymers. A reinforced tissue matrix (RTM) mesh has been developed by embedding a polymer within a decellularized extracellular matrix. This combination has been attributed to the recruitment of host cells, a pro-healing response, and attenuation of the foreign body response. This has been observed to lead to the regeneration of functional tissue within the repair site that is reinforced by the polymer to offload abdominal pressures over time. This manuscript presents the review of OviTex, an RTM, in several types of hernia repair. The authors have found that the use of RTM in hernia repair is effective in preventing foreign body response, promoting wound healing, and providing reinforcement to lower the risk of hernia recurrence.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Poly-4-Hydroxybutyric Acid Mesh Compares Favorably With Acellular Dermal Matrix in Tissue Expander-Based Breast Reconstruction

BACKGROUND

Acellular dermal matrix (ADM) is commonly used during immediate expander-based breast reconstruction, with potential advantages of greater intraoperative expansion, decreased time to complete expansion, and decreased rates of capsular contracture. However, ADM is associated with increased infection rate, seroma, and subsequent reconstructive failure. Poly-4-hydroxybutyric acid (P4HB) mesh is a large pore, biosynthetic scaffold shown to fully resorb and incorporate host tissues within 18 months. We sought to compare outcomes between the use of P4HB and ADM in immediate retropectoral expander-based reconstruction.

METHODS

One hundred ninety-two consecutive cases (107 patients) of breast reconstruction using ADM were compared with a subsequent cohort of 112 cases (62 patients) using P4HB mesh. In all patients, reconstruction was performed immediately after mastectomy by a single surgeon, and outcomes were compared between groups.

RESULTS

Baseline characteristics were similar between the P4HB and ADM groups. Overall infection rates were lower, but not significantly with P4HB (11% vs 17%, P = 0.18). Time to drain removal was significantly lower with P4HB (15 vs 18 days, P = 0.008), although there was no difference in rates of seroma (0.9% vs 3%, P = 0.43). Similar numbers of patients underwent external beam radiation (22% vs 24%) and received chemotherapy in each group (48% vs 45%). By univariate analysis, all odds ratios were decreased with use of P4HB, including risk of major complications (0.55), seroma (0.17), infection (0.59), need for reoperation (0.78), and skin necrosis (0.77).

CONCLUSIONS

Initial findings suggest P4HB mesh to be a safe alternative to ADM in expander-based breast reconstruction, with trends toward decreased rates of infection, seroma, and need for device removal using P4HB mesh. Although our results are limited to a small series of initial patients, P4HB mesh may be a promising novel technique to decrease complications inherent to use of ADM at a reduced material cost.

Evaluation of a Novel Absorbable Mesh in a Porcine Model of Abdominal Wall Repair

Bioabsorbable meshes have seen increasing clinical use to reinforce soft tissue, and exist on a spectrum of strength loss versus absorption: several retain their strength for months, but remain in situ for years. Others lose strength fully by 6 weeks. An intermediate profile, with some strength for 3 -4 months, but consistent absorption in less than a year, may be an optimal balance of near-term support and long-term safety. In this large animal study, we evaluate such a mesh (DuraSorb, SIA), assessing its utility in a porcine model of abdominal wall repair.

METHODS

Two full-thickness defects were created in the abdominal walls of nine Yucatan swine via midline approach and repaired preperitoneally with either DuraSorb or long-lasting control mesh (TIGR, Novus Scientific). At 30 days, 3 months, and 1 year, the implantations were assessed by clinical pathology, post-necropsy histopathology, and burst strength testing.

RESULTS

No device-associated complications were found in vivo, at necropsy, or histologically. DuraSorb was well-integrated and vascularized by 30 days. DuraSorb demonstrated minimal/mild inflammation and fibroplasia, and lower inflammatory scores when compared with TIGR at all time points (P < 0.05). Burst strength of the repair sites was higher than adjacent abdominal wall at all time points (P < 0.05).

CONCLUSIONS

DuraSorb provided durable long-term support, minimal inflammation, and consistent absorption in this porcine model of abdominal wall repair, as compared to a long-term control. Clinical data is needed, but these results suggest that this mesh provides adequate structural support while potentially reducing long-term device reactions.

Functionalized Strategies and Mechanisms of the Emerging Mesh for Abdominal Wall Repair and Regeneration

Meshes have been the overwhelmingly popular choice for the repair of abdominal wall defects to retrieve the bodily integrity of musculofascial layer. Broadly, they are classified into synthetic, biological and composite mesh based on their mechanical and biocompatible features. With the development of anatomical repair techniques and the increasing requirements of constructive remodeling, however, none of these options satisfactorily manages the conditional repair. In both preclinical and clinical studies, materials/agents equipped with distinct functions have been characterized and applied to improve mesh-aided repair, with the importance of mesh functionalization being highlighted. However, limited information exists on systemic comparisons of the underlying mechanisms with respect to functionalized strategies, which are fundamental throughout repair and regeneration. Herein, we address this topic and summarize the current literature by subdividing common functions of the mesh into biomechanics-matched, macrophage-mediated, integration-enhanced, anti-infective and antiadhesive characteristics for a comprehensive overview. In particular, we elaborate their effects separately with respect to host response and integration and discuss their respective advances, challenges and future directions toward a clinical alternative. From the vastly different approaches, we provide insight into the mechanisms involved and offer suggestions for personalized modifications of these emerging meshes.

Prevention of incisional hernia at the site of stoma closure with different reinforcing mesh types: a systematic review and meta-analysis

Purpose

To evaluate safety and efficacy of a mesh reinforcement following stoma reversal to prevent stoma site incisional hernia (SSIH) and differences across the prostheses used.

Methods

A systematic search of PubMed/MEDLINE, EMBASE, SCOPUS and Cochrane databases was conducted to identify comparative studies until September 2020. A meta-analysis of postoperative outcomes and a network meta-analysis for a multiple comparison of the prostheses with each other were performed.

Results

Seven studies were included in the analysis (78.4% ileostomy and 21.6% colostomy) with a total of 1716 patients with (n = 684) or without (n = 1032) mesh. Mesh placement was associated with lower risk of SSIH (7.8%vs18.1%, OR0.266,95% CI 0.123–0.577, p < 0.001) than no mesh procedures but also with a longer operative time (SMD 0.941, 95% CI 0.462–1.421, p < 0.001). There was no statistically significant difference in terms of Surgical Site infection (11.5% vs 11.1%, OR 1.074, 95% CI 0.78–1.48, p = 0.66), seroma formation (4.4% vs 7.1%, OR 1.052, 95% CI 0.64–1.73, p = 0.84), anastomotic leakage (3.7% vs 2.7%, OR 1.598, 95% CI 0.846–3.019, p = 0.149) and length of stay (SMD − 0.579,95% CI − 1.261 to 0.102, p = 0.096) between mesh and no mesh groups. Use of prosthesis was associated with a significant lower need for a reoperation than no mesh group (8.1% vs 12.1%, OR 0.332, 95% CI 0.119–0.930, p = 0.036). Incidence of seroma is lower with biologic than polypropylene meshes but they showed a trend towards poor results compared with polypropylene or biosynthetic meshes.

Conclusion

Despite longer operative time, mesh prophylactic reinforcement at the site of stoma seems a safe and effective procedure with lower incidence of SSIH, need for reoperation and comparable short-term outcomes than standard closure technique. A significant superiority of a specific mesh type was not identified.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10029-021-02393-w.

The Role of Mesh Implants in Surgical Treatment of Parastomal Hernia

A parastomal hernia is a common complication following stoma surgery. Due to the large number of hernial relapses and other complications, such as infections, adhesion to the intestines, or the formation of adhesions, the treatment of hernias is still a surgical challenge. The current standard for the preventive and causal treatment of parastomal hernias is to perform a procedure with the use of a mesh implant. Researchers are currently focusing on the analysis of many relevant options, including the type of mesh (synthetic, composite, or biological), the available surgical techniques (Sugarbaker’s, “keyhole”, or “sandwich”), the surgical approach used (open or laparoscopic), and the implant position (onlay, sublay, or intraperitoneal onlay mesh). Current surface modification methods and combinations of different materials are actively explored areas for the creation of biocompatible mesh implants with different properties on the visceral and parietal peritoneal side. It has been shown that placing the implant in the sublay and intraperitoneal onlay mesh positions and the use of a specially developed implant with a 3D structure are associated with a lower frequency of recurrences. It has been shown that the prophylactic use of a mesh during stoma formation significantly reduces the incidence of parastomal hernias and is becoming a standard method in medical practice.

C-reactive protein is a predictive factor for complications after incisional hernia repair using a biological mesh

The introduction of biological or absorbable synthetic meshes has provided an alternative to conventional repair for incisional hernia. The ability to predict the development of complications after hernia surgery is important, as it guides surgical planning and patient management. This retrospective study assessed whether the postoperative C-reactive protein (CRP) level can predict complications after incisional hernia repair using biological mesh reinforcement. Patients who underwent incisional hernia repair surgery using biological meshes between February 2009 and February 2015 were screened for study inclusion. Patients included in the study were divided into two groups: those with and without postoperative complications. The two groups were analysed based on sex, surgical operation, length of intensive care unit stay (ICU), complications and mortality. Laboratory values, including white blood cell (WBC) count and CRP levels, were determined preoperatively and up to postoperative day (POD) 10. Postoperative complications requiring further management occurred in 32 of the 60 patients (53.3%). Among 47 patients, the mean CRP and WBC levels were 6.6 mg/L and 9.073 G/L in the group without complications vs. 141.0 mg/L, 16.704 G/L in the group with complications (p < 0.001). Patients with complications also had a longer ICU stay (10.1 vs. 0.6 days, p < 0.0001). A cut-off was 101 mg/L and offered 80.00% sensitivity (IC 61.43% to 92.29) and 95.24% specificity (76.18% to 99.88%) for postoperative complication. The rate of postoperative complications before POD10 was 95% in the group with CRP > 100 mg/L vs. 46% in the group with CRP < 100 mg/L (p = 0.000372). A high postoperative CRP level (> 100 mg/L) up to POD10 may serve as a predictor of postoperative complications in patients undergoing incisional hernia using biological meshes.

Risk factors, outcomes, and complications associated with combined ventral hernia and enterocutaneous fistula single-staged abdominal wall reconstruction

PURPOSE

To compare two cohorts of patients; those with isolated ventral hernias (VH) and those with VH and enterocutaneous fistulas (ECF). Risk factors for surgical complications (including recurrent ECF) and outcomes during single-stage VH with ECF surgical reconstruction were analyzed.

METHODS

A retrospective review was performed from 2008 to 2019. We compared two cohorts of patients with single-stage VH repairs: (1) ventral hernia repair alone (hernia alone), and (2) combined VH repair and ECF repair (hernia plus ECF). Inclusion criteria were patients ≥ 18 years of age with pre-operative VH either with or without an ECF, who underwent open hernia repair and ECF repair in a single-stage operation, with a minimum follow-up of 12 months. Patient risk factors, operative characteristics, outcomes and surgical-site complications were compared using univariate and multivariate analyses.

RESULTS

We included 442 patients (hernia alone = 401; hernia plus ECF = 41) with a median follow-up of 22 months (12-96). Hernia plus ECF patients were more likely to have inflammatory bowel disease (IBD)(OR 4.4, 95% CI 1.1-17.5, p = 0.037), a history of abdominal wound infections (OR 3.4, 95% CI 1.5-7.9, p = 0.004), reoperations (OR 4.9, 95% CI 1.6-15.4, p = 0.006), superficial soft tissue infections (OR 2.5, 95% CI 1.1-6.1, p = 0.044) and hematomas (OR 8.4, 95% CI 1.2-58.8, p = 0.031), compared to hernia alone patients. ECF recurrence was associated with diabetes mellitus (DM) (n = 8, 73% vs. n = 6, 20%; p = 0.003) and surgical-site complications (n = 10, 91% vs. n = 16, 53%; p = 0.048), compared to ECF resolution.

CONCLUSION

Risk factors for developing ECF were IBD and history of abdominal wound infections. Single-staged combined ECF reconstruction was associated with reoperations, soft tissue infections and hematomas. DM and surgical-site complications were associated with ECF recurrence.