A review of available prosthetics for ventral hernia repair. Ann Surg. 2011;253:16-26. [PMID: 21135699 DOI: 10.1097/sla.0b013e3181f9b6e6]

One-Step Surface Functionalized Hydrophilic Polypropylene Meshes for Hernia Repair Using Bio-Inspired Polydopamine

An ideal hernia mesh is one that absorbs drugs and withstands muscle forces after mesh implantation. Polypropylene (PP) mesh devices have been accepted as a standard material to repair abdominal hernia, but the hydrophobicity of PP fibers makes them unsuitable to carry drugs during the pre-implantation of PP meshes. In this study, for the first time, one-step functionalization of PP mesh surfaces was performed to incorporate bio-inspired polydopamine (PDA) onto PP surfaces. All PP mesh samples were dipped in the same concentration of dopamine solution. The surface functionalization of PP meshes was performed for 24 h at 37 °C and 80 rpm. It was proved by scanning electron microscopic (SEM) images and Fourier Transform Infrared Spectroscopy (FTIR) results that a thin layer of PDA was connected with PP surfaces. Moreover, water contact angle results proved that surface functionalized PP meshes were highly hydrophilic (73.1°) in comparison to untreated PP mesh surfaces (138.5°). Thus, hydrophilic PP meshes with bio-inspired poly-dopamine functionalization could be a good choice for hernia mesh implantation.

Patient selection criteria for an effective laparoscopic intraperitoneal ventral hernia repair in day surgery

The laparoscopic treatment of abdominal wall defects is currently a valid alternative to the open technique, given the possibility to significantly reduce the length of hospital stay and, consequently, to allow its carrying out in a day surgery setting. The comparison between the two methods has also been the subject of a Cochrane meta-analysis performed by Sauerland et al. (Cochrane Database Syst Rev 3: CD007781, 2011), which pointed out how, in spite of many clinical trials indicating the superiority of laparoscopy in terms of invasiveness and postoperative pain control, the quality of evidence is low due to the excessive variability among the different series in terms of reported complications. Moreover, what should be the selection criteria of patients fit for laparoscopic treatment in day surgery is not yet defined. This retrospective study considered 94 patients with primary or recurrent incisional wall hernias treated with laparoscopic technique over a 7-year period of time, from 2011 to 2018. The aim was to define the selection criteria for an effective day surgery laparoscopic treatment, considering as outcome the rate of conversion to ordinary hospitalization (discharge > POD1). Discharge > POD 1 was necessary in 15 cases out of 94 (16%). Concerning this outcome, statistically significant risk factors were ASA score > I (p = 0.022), number of hernia orifices > 1 (p = 0.001), recurrent hernias (p = 0.002) and hernia diameter > 10 cm (p < 0.0001). These factors were confirmed by univariate binary logistic analysis. A stepwise model of multivariate analysis showed as determinants for adverse events ASA score > 1 (OR 5.2, 95% CI 1.1-25.6, p = 0.043) and hernias > 10 cm (OR 7.0, 95% CI 1.1-46.4, p = 0.045). This work highlighted some useful criteria for preoperative selection of patients fit for laparoscopic abdominal wall defects repair in a day surgery setting. In particular, criteria related to a favorable clinical outcome were ASA score < II and a hernia diameter < 10 cm.

Adhesion Prevention to Polypropylene Meshes Using Combined Icodextrin Four Percent and Dimetindene Maleate

BACKGROUND

The use of surgical meshes in ventral hernia repair has significantly reduced hernia recurrence rates. However, when placed intraperitoneally prosthetic materials can trigger the development of peritoneal adhesions. The present experimental study evaluated the combined icodextrin 4% and dimetindene maleate treatment in preventing peritoneal adhesion formation to polypropylene and titanium-coated polypropylene meshes.

MATERIALS AND METHODS

Sixty female white rabbits were divided into four groups. A 2 × 2 cm piece of mesh was fixed to intact peritoneum in all animals through a midline laparotomy. A lightweight polypropylene mesh was implanted in groups 1 and 2 and a titanium-coated polypropylene mesh in groups 3 and 4. Groups 2 and 4 were treated, intraoperatively, with intravenous dimetindene maleate (0.1 mg/kg) and intraperitoneal solution of icodextrin 4% (20 mL/kg) and for the next 6 d with dimetindene maleate intramuscularly. The observation period lasted 15 d. Adhesion scores, percentage of mesh affected surface, tissue hydroxyproline levels, and tissue histopathology were examined.

RESULTS

All animals in group 1 and 57% of animals in group 3 presented postoperative adhesions. The combination of antiadhesives significantly reduced the extent and severity of adhesions as well as the hydroxyproline levels in groups 2 and 4 compared with groups 1 and 3. On microscopic evaluation, animals in group 1 exhibited higher inflammation scores compared with group 2, whereas animals in groups 2 and 4 had better mesotheliazation compared with groups 1 and 3.

CONCLUSIONS

The combined administration of icodextrin 4% and dimetindene maleate reduces the extent and severity of adhesions and may be successfully used to prevent adhesion formation after mesh intraperitoneal placement.

"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.

The painless combination of anatomically contoured titanium plates and porcine dermal collagen patch for chest wall reconstruction

Background

A plethora of new biomaterials and dedicated rib fixator implant systems have been introduced into the field of chest wall reconstruction. The aim of our study is to evaluate the surgical outcomes of a novel combination of the anatomically contoured titanium rib implant and porcine dermal collagen patch for chest wall reconstruction.

Methods

We performed a retrospective review of eight consecutive patients who underwent chest wall resection and reconstruction between January 2014 to August 2015 in a single institution. MatrixRib Fixation System and Permacol Surgical Implant were utilized to achieve chest wall reconstruction.

Results

The indication for reconstruction was malignant infiltration in 50% of patients. Three other subjects (37.5%) had chest wall resections to achieve adequate and safe surgical exposure. One patient had a right lung apical mycetoma with chest wall invasion. All patients underwent lung resections with the removal of 2 to 6 (median 3) ribs. Reconstruction was performed using the MatrixRib system, with a median of 2.5 (range, 2-4) ribs fixed in each patient. There was no post-operative mortality. One patient had a superficial wound infection which resolved with one week of oral antibiotics. Upon discharge, the pain scores were near zero with minimal analgesic requirements. None of the patients required repeat surgery or removal of their implants.

Conclusions

Our early experience indicates that the combination of the MatrixRib system and Permacol patch for chest wall reconstruction is safe and feasible with promising results in terms of anatomical restoration of the chest wall mechanics, infection and pain.

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

Background

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

Methods

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

Results

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

Conclusion

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

Hyaluronan enhancement of expanded polytetrafluoroethylene cardiovascular grafts

Heart disease continues to be the leading cause of death in the United States. The demand for cardiovascular bypass procedures increases annually. Expanded polytetrafluoroethylene is a popular material for replacement implants, but it does have drawbacks such as high thrombogenicity and low patency, particularly in small diameter grafts. Hyaluronan, a naturally occurring polysaccharide in the human body, is known for its wound healing and anticoagulant properties. In this work, we demonstrate that treating the luminal surface of expanded polytetrafluoroethylene grafts with hyaluronan improves hemocompatibility without notably changing its mechanical properties and without significant cytotoxic effects. Surface characterization such as ATR-FTIR and contact angle goniometry demonstrates that hyaluronan treatment successfully changes the surface chemistry and increases hydrophilicity. Tensile properties such as elastic modulus, tensile strength, yield stress and ultimate strain are unchanged by hyaluronan enhancement. Durability data from flow loop studies demonstrate that hyaluronan is durable on the expanded polytetrafluoroethylene inner lumen. Hemocompatibility tests reveal that hyaluronan-treated expanded polytetrafluoroethylene reduces blood clotting and platelet activation. Together our results indicate that hyaluronan-enhanced expanded polytetrafluoroethylene is a promising candidate material for cardiovascular grafts.

A polypropylene mesh modified with poly-ε-caprolactone nanofibers in hernia repair: large animal experiment

Purpose

Incisional hernia repair is an unsuccessful field of surgery, with long-term recurrence rates reaching up to 50% regardless of technique or mesh material used. Various implants and their positioning within the abdominal wall pose numerous long-term complications that are difficult to treat due to their permanent nature and the chronic foreign body reaction they trigger. Materials mimicking the 3D structure of the extracellular matrix promote cell adhesion, proliferation, migration, and differentiation. Some electrospun nanofibrous scaffolds provide a topography of a natural extracellular matrix and are cost effective to manufacture.

Materials and methods

A composite scaffold that was assembled out of a standard polypropylene hernia mesh and poly-ε-caprolactone (PCL) nanofibers was tested in a large animal model (minipig), and the final scar tissue was subjected to histological and biomechanical testing to verify our in vitro results published previously.

Results

We have demonstrated that a layer of PCL nanofibers leads to tissue overgrowth and the formation of a thick fibrous plate around the implant. Collagen maturation is accelerated, and the final scar is more flexible and elastic than under a standard polypropylene mesh with less pronounced shrinkage observed. However, the samples with the composite scaffold were less resistant to distracting forces than when a standard mesh was used. We believe that the adverse effects could be caused due to the material assembly, as they do not comply with our previous results.

Conclusion

We believe that PCL nanofibers on their own can cause enough fibroplasia to be used as a separate material without the polypropylene base, thus avoiding potential adverse effects caused by any added substances.

Sirolimus-coated, poly(L-lactic acid)-modified polypropylene mesh with minimal intra-peritoneal adhesion formation in a rat model

PURPOSE

This study evaluated the manufacturing method and anti-adhesion properties of a new composite mesh in the rat model, which was made from sirolimus (SRL) grafts on a poly(L-lactic acid) (PLLA)-modified polypropylene (PP) hernia mesh.

METHODS

PLLA was first grafted onto argon-plasma-treated native PP mesh through catalysis of stannous chloride. SRL was grafted onto the surface of PP-PLLA meshes using catalysis of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) and 4-dimethylaminopyridine (DMAP) in a CH₂Cl₂ solvent. Sprague-Dawley female rats received either SRL-coated meshes, PP-PLLA meshes, or native PP meshes to repair abdominal wall defects. At different intervals, rats were euthanized by a lethal dose of chloral hydrate and adhesion area and tenacity were evaluated. Sections of the mesh with adjacent tissues were assessed histologically.

RESULTS

Attenuated total reflection Fourier transformed infrared (ATR-FTIR) spectroscopy indicated the existence of a C=O group absorption peak (1724.1 cm^-1), and scanning electron microscope morphological analysis indicated that the surface of the PP mesh was covered with SRL. Compared to the native PP meshes and PP-PLLA meshes, SRL-coated meshes demonstrated the greatest ability to decrease the formation of adhesions (P < 0.05) and inflammation.

CONCLUSIONS

The SRL-coated composite mesh showed minimal formation of intra-abdominal adhesions in a rat model of abdominal wall defect repair.

Lightweight, Highly Permeable, Biocompatible, and Antiadhesive Composite Meshes for Intraperitoneal Repairs

Ventral hernia is a public health issue and millions of meshes are used to repair abdominal wall defects every year. Polypropylene-based composite meshes represent an important class of materials for intraperitoneal repair, but the meshes generally give rise to infection, seroma, migration, and adhesion, leading to severe consequence or even reoperation. Here, a facile and versatile one-way fabrication of lightweight, highly permeable, and biocompatible composite meshes with superior antiadhesion properties is proposed by modifying polypropylene meshes with well-defined polydopamine nanocoating. The resulting composite meshes are found to significantly enhance the biocompatibility and antiadhesion effect in rat model. The scalable production and excellent biomedical properties of composite meshes make them a promising candidate for future-generation ventral hernia repair materials.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

Background

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

Methods

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

Results

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

Conclusion

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

The results of expanded-polytetrafluoroethylene mesh repair in difficult abdominal wall defects

BACKGROUND

The repair of difficult abdominal wall defects (AWDs) continues to be a crucial and demanding issue for surgeons. This study aimed to present the risk factors and the long-term results of usage of an expanded-polytetrafluoroethylene (e-PTFE) synthetic mesh for the AWR of difficult abdominal wall defects.

METHODS

This study included 156 adult patients who underwent difficult AWR with e-PTFE mesh for incisional hernia, ventral hernia, and created AWDs of various etiopathologies. The association between the risk factors and the postoperative complications of AWR was analyzed, and overall long-term outcomes of e-PTFE repair were assessed.

RESULTS

The median follow-up duration was 119.1 (ranging from 2 to 206) months. In 70 (44.8%) patients, there were major co-morbidities. A surgical site infection developed in 17 (10.9%) patients. Of these, only 2 (1.3%) patients had e-PTFE mesh infection. Seven (4.4%) patients experienced recurrence. Recalcitrant seroma formation occurred in 8 (36.3%) patients.

CONCLUSION

E-PTFE synthetic mesh usage for difficult abdominal wall hernias can help the hernia surgeon obtain safe and durable long-term results of sound repair.

The State of Prophylactic Mesh Augmentation

Prophylactic mesh augmentation (PMA) is the implantation of mesh during closure of an index laparotomy to decrease a patient's risk for developing incisional hernia (IH). The current body of evidence lacks refined guidelines for patient selection, mesh placement, and material choice. The purpose of this study is to summarize the literature and identify areas of research needed to foster responsible and appropriate use of PMA as an emerging technique. We conducted a comprehensive review of Scopus, Cochrane, PubMed, and clinicaltrials.gov for articles and trials related to using PMA for IH risk reduction. We further supplemented our review by including select papers on patient-reported outcomes, cost utility, risk modeling, surgical techniques, and available materials highly relevant to PMA. Five-hundred-fifty-one unique articles and 357 trials were reviewed. Multiple studies note a significant decrease in IH incidence with PMA compared with primary suture-only–based closure. No multicenter randomized control trial has been conducted in the United States, and only two such trials are currently active worldwide. Evidence exists supporting the use of PMA, with practical cost utility and models for selecting high-risk patients, but standard PMA guidelines are lacking. Although Europe has progressed with this technique, widespread adoption of PMA requires large-scale pragmatic randomized control trial research, strong evidence-based guidelines, current procedural terminology coding, and resolution of several barriers.

Early Wound Morbidity after Open Ventral Hernia Repair with Biosynthetic or Polypropylene Mesh

BACKGROUND

Recently introduced slow-resorbing biosynthetic and non-resorbing macroporous polypropylene meshes are being used in hernias with clean-contaminated and contaminated wounds. However, information about the use of biosynthetic meshes and their outcomes compared with polypropylene meshes in clean-contaminated and contaminated cases is lacking. Here we evaluate the use of biosynthetic mesh and polypropylene mesh in elective open ventral hernia repair (OVHR) and investigate differences in early wound morbidity after OVHR within clean-contaminated and contaminated cases.

STUDY DESIGN

All elective, OVHR with biosynthetic mesh or uncoated polypropylene mesh from January 2013 through October 2016 were identified within the Americas Hernia Society Quality Collaborative. Association of mesh type with 30-day wound events in clean-contaminated or contaminated wounds was investigated using a 1:3 propensity-matched analysis.

RESULTS

Biosynthetic meshes were used in 8.5% (175 of 2,051) of elective OVHR, with the majority (57.1%) used in low-risk or comorbid clean cases. Propensity-matched analysis in clean-contaminated and contaminated cases showed no significant difference between biosynthetic mesh and polypropylene mesh groups for 30-day surgical site occurrences (20.7% vs 16.7%; p = 0.49) or unplanned readmission (13.8% vs 9.8%; p = 0.4). However, surgical site infections (22.4% vs 10.9%; p = 0.03), surgical site occurrences requiring procedural intervention (24.1% vs 13.2%; p = 0.049), and reoperation rates (13.8% vs 4.0%; p = 0.009) were significantly higher in the biosynthetic group.

CONCLUSIONS

Biosynthetic mesh appears to have higher rates of 30-day wound morbidity compared with polypropylene mesh in elective OVHR with clean-contaminated or contaminated wounds. Additional post-market analysis is needed to provide evidence defining best mesh choices, location, and surgical technique for repairing contaminated ventral hernias.

A collective review of biological versus synthetic mesh-reinforced cruroplasty during laparoscopic Nissen fundoplication

Background:

Laparoscopic cruroplasty and fundoplication have become the gold standard in the treatment of hiatal hernia and gastro-oesophageal reflux disease (GERD). The use of a mesh-reinforcement of the cruroplasty has been proven effective; although, there is a lack of evidence considering which type of mesh is superior. The aim of this study was to compare recurrence rates after mesh reinforced cruroplasty using biological versus synthetic meshes.

Methods:

We performed a systematic review of all clinical trials published between January 2004 and September 2015 describing the application of a mesh in the hiatal hernia repair during Nissen fundoplication for both GERD and hiatal hernia. The primary outcome was the recurrence rate, and secondary outcomes were complication rate, mortality and symptomatic outcome.

Results:

We included 16 studies and extracted data regarding 1089 mesh operated patients of whom 385 received a biological mesh and 704 a synthetic mesh. The mean follow-up was 53.4 months. The recurrence rate in the synthetic mesh group was 6.8% compared to 16.1% in the biological mesh group (P < 0.05). The complication rate was 5.1% and 4.6% (P = 0.694), respectively, and there were 12 mesh-related complications. No mesh-related mortality was reported.

Conclusion:

Mesh reinforcement of hiatal hernia repair seems safe in the short-term follow-up. The available literature suggests no clear advantage of biological over synthetic meshes. Regarding cost-efficiency and short-term results, the use of synthetic nonabsorbable meshes might be advocated.

Transperineal rectocele repair: a systematic review

BACKGROUND

Transperineal rectocele repairs, either as isolated fascial repair or in combination with mesh augmentation, are hypothesized to reduce the risk of complications compared with alternative techniques.

AIM

The aim of this study was to ascertain long-term success and complication rates following transperineal rectocele repairs.

METHOD

A literature search of PubMed and Embase was performed using the terms 'transperineal rectocele', 'rectocele', 'transperineal' and 'repair'. Prospective studies, case series and retrospective case note analyses from 1 January 1994 to 1 December 2016 were included. Those that detailed outcomes of the transperineal approach or compared it to transanal/transvaginal approaches were included. The main outcome measures were reported complications and functional outcome scores.

RESULTS

A total of 14 studies were included. Of 566 patients, 333 (58.8%) underwent a transperineal rectocele repair and 220 (41.2%) a transanal repair. Complications were identified in 27 (12.3%) of the 220 transanal repairs and in 41 (12.3%) of the 333 transperineal repairs. A significant complication following transperineal repair was noted in eight studies. There are not enough data to make a reliable comparison between mesh and non-mesh transperineal repairs or to compare biological and synthetic mesh use.

LIMITATIONS

Outcome reporting differed between studies, precluding a full meta-analysis.

CONCLUSION

Transperineal rectocele repair offers an effective method of symptom improvement and appears to have a similar complication rate as transanal rectocele repair. Concomitant use of synthetic and biological mesh augmentation is becoming more common; however, high-quality comparative data are lacking, so a direct comparison between surgical approaches is not yet possible.

Comparison of Synthetic and Biologic Mesh in Ventral Hernia Repair Using Components Separation Technique

Ventral hernia repair (VHR) for large abdominal wall defects is challenging. Prior research established that the use of mesh is superior to suture closure alone and that component separation is an effective technique to combat loss of abdominal domain. Studies comparing component separation technique (CST) outcomes utilizing synthetic versus biologic mesh are limited. A retrospective review was conducted of 72 consecutive patients who underwent VHR with CST between 2006 and 2010 at our institution. Surgeon preference and the presence of contamination guided whether synthetic mesh (27 patients) or biologic mesh (45 patients) was used. Mean follow-up interval for all comers was 13.9 months and similar in both groups (P > 0.05). Degree of contamination and severity of premorbid medical conditions were significantly higher in the biologic mesh group, as reflected in the higher Ventral Hernia Working Group (VHWG) score (2.04 versus 2.86). Clinical outcomes, as measured by both minor and major complication rates and recurrence rates, were not significantly different. Minor complication rates were 26% in the synthetic group and 37% in the biologic group and major complication rates 15% in the synthetic group and 22% in the biologic group. There was 1 recurrence (4%) in the synthetic mesh group versus 5 (11%) in the biologic mesh group. Multivariable analysis for major complications revealed no significant difference for either synthetic or biologic mesh while controlling for other variables. Subset analysis of uncontaminated cases revealed recurrence rates of 4% in the synthetic mesh group and 6% in the biologic mesh group. VHR using CST and either synthetic mesh or biologic mesh resulted in low recurrence rates with similar overall complication profiles, despite the higher average VHWG grading score in the biologic mesh group. Our results support the VHWG recommendation for biologic mesh utilization in higher VHWG grade patients. In VHWG grade 2 patients, our clinical outcomes were similar, supporting the use of either type of mesh.

Challenging abdominal incisional hernia repaired with platelet-rich plasma and bone marrow-derived mesenchymal stromal cells. A case report

•

New treatment options for challenging procedures in hernia surgery are necessary.

•

Possibility of improving prosthetic compatibility and reducing future recurrences.

•

Tissue engineering offers new strategies to improve fascial healing.

•

Case of a surgeon – challenging abdominal incisional hernia.

•

Treatment provided was PRP and BM-MSCs on a biological mesh.

Introduction

The necessity to develop new treatment options for challenging procedures in hernia surgery is becoming even more evident and tissue engineering and biological technologies offer even newer strategies to improve fascial healing. The present case reports a patient-tailored surgical technique performed to repair a grade IV abdominal incisional hernia, with a combined use of platelet-rich plasma and bone marrow-derived mesenchymal stromal cells, implanted on a biological mesh.

Presentation of the case

A 71 year-old female patient complained of an abdominal incisional hernia, complicated by enterocutaneous fistula, four-months following laparostomy. Contrast enhanced computed tomography showed an incisional hernia defect of 15.5 × 20 cm, with a subcutaneous abscess and an intestinal loop adherent to the anterior abdominal wall, with a concomitant enterocutaneous fistula. Surgery involved abdominal wall standardized technique closure, with in addition platelet-rich plasma and bone marrow-derived mesenchymal stromal cells implanted on a biological mesh. Two years follow up showed no recurrences of incisional hernia.

Discussion

Coating surgical meshes with patient’s own cells may improve biocompatibility, by reducing inflammation and adhesion formation. Moreover, platelet-rich plasma is a good source of growth factors for wound healing, as well as a good medium for bone marrow multinucleate cells introduction into fascial repair.

Conclusion

This approach is likely to improve abdominal wall repair in high grade (IV) incisional hernia, with the real possibility of improving prosthetic compatibility and reducing future recurrences. The authors agree with the necessity of further studies and trials to assure the safety profile and superiority of this procedure.

Critical overview of all available animal models for abdominal wall hernia research

PURPOSE

Since the introduction of the first prosthetic mesh for abdominal hernia repair, there has been a search for the "ideal mesh." The use of preclinical or animal models for assessment of necessary characteristics of new and existing meshes is an indispensable part of hernia research. Unfortunately, in our experience there is a lack of consensus among different research groups on which model to use. Therefore, we hypothesized that there is a lack of comparability within published animal research on hernia surgery due to wide range in experimental setup among different research groups.

METHODS

A systematic search of the literature was performed to provide a complete overview of all animal models published between 2000 and 2014. Relevant parameters on model characteristics and outcome measurement were scored on a standardized scoring sheet.

RESULTS

Due to the wide range in different animals used, ranging from large animal models like pigs to rodents, we decided to limit the study to 168 articles concerning rat models. Within these rat models, we found wide range of baseline animal characteristics, operation techniques, and outcome measurements. Making reliable comparison of results among these studies is impossible.

CONCLUSION

There is a lack of comparability among experimental hernia research, limiting the impact of this experimental research. We therefore propose the establishment of guidelines for experimental hernia research by the EHS.

Absorbable Meshes in Inguinal Hernia Surgery: A Systematic Review and Meta-Analysis

PURPOSE

Absorbable meshes used in inguinal hernia repair are believed to result in less chronic pain than permanent meshes, but concerns remain whether absorbable meshes result in an increased risk of recurrence. The aim of this study was to present an overview of the advantages and limitations of fully absorbable meshes for the repair of inguinal hernias, focusing mainly on postoperative pain and recurrence.

METHODS

This systematic review with meta-analyses is based on searches in PubMed, Embase, Cochrane, and Psychinfo. Included study designs were case series, cohort studies, randomized controlled trials (RCTs), and non-RCTs. Studies had to include adult patients undergoing an inguinal hernia repair with a fully absorbable mesh.

RESULTS

The meta-analyses showed no difference in recurrence rates (median 18 months follow-up) and chronic pain rates (1 year follow-up) between absorbable- and permanent meshes. Crude chronic pain rates for the RCTs were 2.1% for the absorbable meshes and 7.6% for the permanent meshes. For the absorbable meshes, medial hernias were more susceptible for recurrence compared with lateral hernias ( P < .0005). None of the studies reported allergic reactions or other serious adverse events related to the absorbable mesh.

CONCLUSIONS

Patients with an absorbable mesh seem to have less chronic pain following inguinal hernia surgery compared with permanent meshes, without increased risk of recurrence.

Desmoid Fibromatosis of the Abdominal Wall: Surgical Resection and Reconstruction with Biological Matrix Egis®

Desmoid tumor is a rare monoclonal fibroblast proliferation that is regarded as benign. The clinical management of desmoid tumors is very complex and requires a multidisciplinary approach because of the unpredictable disease course. For those cases localized in the anterior abdominal wall, symptomatic and unresponsive to medical treatment, radical resection and reconstruction with a prosthetic device are indicated. We present here a case of desmoid fibromatosis of the left anterolateral abdominal wall with a marked increase of the mass that required a large excision followed by reconstruction with biological matrix. The fact that it can be incorporated in patient tissue without a fibrotic response and that it can resist future infections, together with a very competetive price, made the new collagen matrix Egis^® our first choice.

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

STUDY AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

Mechanical strength vs. degradation of a biologically-derived surgical mesh over time in a rodent full thickness abdominal wall defect

The use of synthetic surgical mesh materials has been shown to decrease the incidence of hernia recurrence, but can be associated with undesirable effects such as infection, chronic discomfort, and adhesion to viscera. Surgical meshes composed of extracellular matrix (i.e., biologically-derived mesh) are an alternative to synthetic meshes and can reduce some of these undesirable effects but are less frequently used due to greater cost and perceived inadequate strength as the mesh material degrades and is replaced by host tissue. The present study assessed the temporal association between mechanical properties and degradation of biologic mesh composed of urinary bladder matrix (UBM) in a rodent model of full thickness abdominal wall defect. Mesh degradation was evaluated for non-chemically crosslinked scaffolds with the use of (14)C-radiolabeled UBM. UBM biologic mesh was 50% degraded by 26 days and was completely degraded by 90 days. The mechanical properties of the UBM biologic mesh showed a rapid initial decrease in strength and modulus that was not proportionately associated with its degradation as measured by (14)C. The loss of strength and modulus was followed by a gradual increase in these values that was associated with the deposition of new, host derived connective tissue. The strength and modulus values were comparable to or greater than those of the native abdominal wall at all time points.

Feasibility study from a randomized controlled trial of standard closure of a stoma site vs biological mesh reinforcement

AIM

Hernia formation occurs at closed stoma sites in up to 30% of patients. The Reinforcement of Closure of Stoma Site (ROCSS) randomized controlled trial is evaluating whether placement of biological mesh during stoma closure safely reduces hernia rates compared with closure without mesh, without increasing surgical or wound complications. This paper aims to report recruitment, deliverability and safety from the internal feasibility study.

METHOD

A multicentre, patient and assessor blinded, randomized controlled trial, delivered through surgical trainee research networks. A 90-patient internal feasibility study assessed recruitment, randomization, deliverability and early (30 day) safety of the novel surgical technique (ClinicalTrials.gov registration number NCT02238964).

RESULTS

The feasibility study recruited 90 patients from the 104 considered for entry (45 to mesh, 45 to no mesh). Seven of eight participating centres randomized patients within 30 days of opening. Overall, 41% of stomas were created for malignant disease and 73% were ileostomies. No mesh-specific complications occurred. Thirty-one postoperative adverse events were experienced by 31 patients, including surgical site infection (9%) and postoperative ileus (6%). One mesh was removed for re-access to the abdominal cavity, for reasons unrelated to the mesh. Independent review by the Data Monitoring and Ethics Committee of adverse event data by treatment allocation found no safety concerns.

CONCLUSION

Multicentre randomization to this trial of biological mesh is feasible, with no early safety concerns. Progression to the full Phase III trial has continued. ROCSS shows that trainee research networks can efficiently develop and deliver complex interventional surgical trials.

Biological and proteomic characterization of a composite mesh for abdominal wall hernia treatment: Reference Study

AIMS

The industrial development of a product requires performing a deep analysis to highlight its characteristics useful for future design. The clinical use of a product stimulates knowledge improvement about it in a constant effort of progress. This work shows the biological characterization of CMC composite mesh. CMC polypropylene prosthesis was seeded with Human fibroblast BJ. Samples (cells and medium) were collected at different time points in order to perform different analysis: inflammatory markers quantification; collagens immunohistochemistry; matrix metalloproteinases zimography; extracellular matrix proteomic profile.

FINDINGS

CMC presented a good cell viability rate and cell growth during the 21 days. The inflammatory profile showed an initial secretion of anti-inflammatory IL-10 and a final increase of pro-inflammatory IL-6. Immunocytochemistry highlighted a similar Collagen type I/type III ratio. The proteomic analysis evidenced the ECM protein content profile composed, mainly, by collagens, fibronectin, laminin. MMPs resulted both expressed when in contact to mesh.

CONCLUSIONS

CMC shows a good cell biocompatibility and growth. The increase of pro-inflammatory markers could stimulate proliferation, influencing the integration process in human body. Proteomics highlights the ECM modulation by CMC. An integrated investigation of these biological analyses with mechanical data should improve the design process of a new product. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2045-2052, 2017.

Outcomes of Retromuscular Porcine Biologic Mesh Repairs Using Transversus Abdominis Release Reconstruction

BACKGROUND

Optimal mesh reinforcement and operative technique for major abdominal wall reconstructions (AWR) remain debatable. Posterior component separation via transversus abdominis release (TAR) allows for wide sublay mesh reinforcement with durable reconstruction, and has been gaining popularity in recent years. Although biologic mesh has been associated with mixed results, outcomes of AWR with bioprosthetics have not been well elucidated to date. We evaluated our outcomes of TAR reconstructions with retromuscular porcine biologic mesh reinforcement.

STUDY DESIGN

Consecutive patients undergoing AWR using TAR with biologic mesh sublay reinforcement were identified in our prospective databases and analyzed. We characterized patient demographics and perioperative details. Main outcomes measures included wound complications and hernia recurrence.

RESULTS

Between 2007 and 2014, seventy-seven patients (mean age 56 years, mean BMI 35 kg/m(2)) underwent AWR using TAR with biologic mesh. Mean hernia size was 306 ± 128 cm(2) with mean width of 14.3 ± 3.3 cm. The vast majority of patients had grade 3 hernias (92%) and more than half had a history of wound infection (55%). There were 22 (28.6%) surgical site infections consisting of 14 deep, 7 superficial, and 1 organ-space surgical site infections. There were no incidences of chronic mesh infection or explantation. In patients with at least 12 months follow-up (mean duration 28.2 months), there were 8 (12.5%) recurrences.

CONCLUSIONS

Complex hernias repaired with TAR and retromuscular porcine biologic mesh reinforcement are associated with a low rate of serious perioperative wound/mesh complications. Additionally, our approach resulted in a fairly low rate of hernia recurrences in this complex cohort of patients. We believe that the TAR approach and retromuscular mesh placement can be beneficial when biologic mesh reinforcement is chosen during complex and/or contaminated abdominal wall reconstructions.

Biologic mesh for repair of ventral hernias in contaminated fields: long-term clinical and patient-reported outcomes

BACKGROUND

Guidelines recommend biologic prosthetics for ventral hernia repair (VHR) in contaminated fields, yet long-term and patient-reported data are limited. We aimed to determine the long-term rate of hernia recurrence, and other clinical and patient-reported outcomes following the use of porcine small intestine submucosa (PSIS) for VHR in a contaminated field.

METHODS

Consecutive patients undergoing open VHR with PSIS mesh in a contaminated field from 2004 to 2014 were prospectively evaluated for hernia recurrence and other post-operative complications. Multivariate logistic and Cox regression analyses identified predictors of hernia recurrence and surgical site infection. Patient-reported outcomes were evaluated using SF-36, Hernia-Related Quality-of-Life Survey (HerQLes) and Body Image Questionnaire instruments.

RESULTS

Forty-six hernias were repaired in clean-contaminated [16 (35 %)], contaminated [11 (24 %)] and dirty [19 (41 %)] fields. Median follow-up was 47 months [interquartile range: 31-79] and all patients had greater than 12-month follow-up. Sixteen patients (35 %) were not re-examined. Incidence of surgical site events and surgical site infection were 43 % (n = 20) and 56 % (n = 25), respectively. American Society of Anesthesiologists score 3 or greater was an independent predictor of surgical site infection (odds ratio 5.34 [95 % confidence interval 1.01-41.80], p = 0.04). Hernia recurrence occurred in 61 % (n = 28) with a median time to diagnosis of 16 months [interquartile range 8-26]. After bridged repair, 16 of 18 patients (89 %) recurred, compared to 12 of 28 (43 %) when fascia was approximated (p < 0.01). Bridged repair was an independent predictor of recurrence (odds ratio 10.67 [95 % confidence interval 2.42-76.08], p < 0.01). Patients with recurrences had significantly worse scores on the SF-36 mental health component and self-perceived body image, whereas HerQLes scores were similar.

CONCLUSIONS

Hernia recurrences and wound infections are high with the use of biologic PSIS mesh in contaminated surgical fields. Careful consideration is warranted using this approach.

Posterior Component Separation with Transversus Abdominis Release: Technique, Utility, and Outcomes in Complex Abdominal Wall Reconstruction

BACKGROUND

Ventral hernia formation is a frequent and increasingly difficult problem. Nonmidline hernias, parastomal hernias, hernias near bony landmarks, and recurrent ventral hernias (especially after anterior component separation) present particular challenges. Typical reconstructive techniques may struggle to reestablish abdominal domain and to create a lasting repair. Posterior component separation with transversus abdominis release is a novel technique that offers a durable solution to a variety of complex ventral hernias.

METHODS

The posterior rectus sheath is incised and the retrorectus plane is developed. In a modification of the Rives-Stoppa technique, the transversus abdominis is released medial to the linea semilunaris to expose a broad plane that extends from the central tendon of the diaphragm superiorly, to the space of Retzius inferiorly, and laterally to the retroperitoneum. This preserves the neurovascular bundles innervating the medial abdominal wall. Mesh is placed in a sublay fashion above the posterior layer. In an overwhelming majority of patients, the linea alba is reconstructed, creating a functional abdominal wall with wide mesh reinforcement.

RESULTS

The technique is reliable and durable, with a 5 percent recurrence rate at 2 years. Although wound complications occur with a frequency similar to that of other techniques, they tend to be less severe, rarely requiring operative débridement. The technique is applicable to a broad range of hernias, including midline, parastomal, flank, subcostal, and recurrent hernias after prior component separations.

CONCLUSION

Posterior component separation with transversus abdominis release is a versatile, easy-to-learn technique of hernia repair that offers a reliable, durable solution to complex abdominal wall reconstruction.

Cost of ventral hernia repair using biologic or synthetic mesh

BACKGROUND

Patients undergoing ventral hernia repair (VHR) with biologic mesh (BioM) have higher hospital costs compared with synthetic mesh (SynM). This study compares 90-d pre- and post-VHR hospital costs (180-d) among BioM and SynM based on infection risk.

METHODS

This retrospective National Surgical Quality Improvement Program study matched patient perioperative risk with resource utilization cost for a consecutive series of VHR repairs. Patient infection risks, clinical and financial outcomes were compared in unmatched SynM (n = 303) and BioM (n = 72) groups. Propensity scores were used to match 35 SynM and BioM pairs of cases with similar infection risk for outcomes analysis.

RESULTS

BioM patients in the unmatched group were older with higher American Society of Anesthesiologists (ASA) and wound classification, and they more frequently underwent open repairs for recurrent hernias. Wound surgical site infections were more frequent in unmatched BioM patients (P = 0.001) as were 180-d costs ($43.8k versus $14.0k, P < 0.001). Propensity matching resulted in 31 clean cases. In these low-risk patients, wound occurrences and readmissions were identical, but 180-d costs remained higher ($31.8k versus $15.5k, P < 0.001). There were no differences in hospital 180-d diagnostic, emergency room, intensive care unit, floor, pharmacy, or therapeutic costs. However, 180-d operating room services and supply costs were higher in the BioM group ($21.1k versus $7.1k, P < 0.001).

CONCLUSIONS

BioM is used more commonly in hernia repairs involving higher wound class and ASA scores and recurrent hernias. Clinical outcomes after low-risk VHRs are similar; SynM utilization in low-risk hernia repairs was more cost-effective.

Synthetic surgical meshes used in abdominal wall surgery: Part II-Biomechanical aspects

This work reports the second part of a review on synthetic surgical meshes used for abdominal hernia repair. While material and structural characteristics, together with mesh-tissue interaction, were considered in a previous article (Part I), biomechanical behavior is described here in more detail. The role of the prosthesis is to strengthen the impaired abdominal wall, mimicking autologous tissue without reducing its compliance. Consequently, mesh mechanical properties play a crucial role in a successful surgical repair. The main available techniques for mechanical testing, such as uniaxial and biaxial tensile testing, ball burst, suture retention strength, and tear resistance testing, are described in depth. Among these methods, the biaxial tensile test is the one that can more faithfully reproduce the physiological loading condition. An outline of the most significant results documented in the literature is reported, showing the variety of data on mesh mechanical properties. Synthetic surgical meshes generally follow a non-linear stress-strain behavior, with mechanical characteristics dependant on test direction due to mesh anisotropy. Ex-vivo tests revealed an increased stiffness in mesh explants due to the gradual ingrowth of the host tissue after implant. In general, the absence of standardization in test methods and terminology makes it difficult to compare results from different studies. Numerical models of the abdominal wall interacting with surgical meshes were also discussed representing a potential tool for the selection of suitable prostheses. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 892-903, 2017.

Synthetic surgical meshes used in abdominal wall surgery: Part I-materials and structural conformation

Surgical implants are commonly used in abdominal wall surgery for hernia repair. Many different prostheses are currently offered to surgeons, comprising permanent synthetic polymer meshes and biologic scaffolds. There is a wide range of synthetic meshes currently available on the market with differing chemical compositions, fiber conformations, and mesh textures. These chemical and structural characteristics determine a specific biochemical and mechanical behavior and play a crucial role in guaranteeing a successful post-operative outcome. Although an increasing number of studies report on the structural and mechanical properties of synthetic surgical meshes, nowadays there are no consistent guidelines for the evaluation of mechanical biocompatibility or common criteria for the selection of prostheses. The aim of this work is to review synthetic meshes by considering the extensive bibliography documentation of their use in abdominal wall surgery, taking into account their material and structural properties, in Part I, and their mechanical behavior, in Part II. The main materials available for the manufacture of polymeric meshes are described, including references to their chemical composition, fiber conformation, and textile structural properties. These characteristics are decisive for the evaluation of mesh-tissue interaction process, including foreign body response, mesh encapsulation, infection, and adhesion formation. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 689-699, 2017.

Evolution and advances in laparoscopic ventral and incisional hernia repair

Primary ventral hernias and ventral incisional hernias have been a challenge for surgeons throughout the ages. In the current era, incisional hernias have increased in prevalence due to the very high number of laparotomies performed in the 20^th century. Even though minimally invasive surgery and hernia repair have evolved rapidly, general surgeons have yet to develop the ideal, standardized method that adequately decreases common postoperative complications, such as wound failure, hernia recurrence and pain. The evolution of laparoscopy and ventral hernia repair will be reviewed, from the rectoscopy of the 4^th century to the advent of laparoscopy, from suture repair to the evolution of mesh reinforcement. The nuances of minimally invasive ventral and incisional hernia repair will be summarized, from preoperative considerations to variations in intraoperative practice. New techniques have become increasingly popular, such as primary defect closure, retrorectus mesh placement, and concomitant component separation. The advent of robotics has made some of these repairs more feasible, but only time and well-designed clinical studies will tell if this will be a durable modality for ventral and incisional hernia repair.

Direct demonstration of bacterial biofilms on prosthetic mesh after ventral herniorrhaphy

BACKGROUND

Prosthetic mesh is employed routinely in the treatment of ventral and parastomal hernias, but its use can lead to major complications, including infection, extrusion, and fistula. Bacterial biofilms have been posited to play a role in mesh-related infection, but although bacteria have been noted to form biofilms on mesh surfaces in vitro, they have never been visualized directly in biofilms on mesh recovered from patients experiencing infectious complications.

METHODS

Five patients who developed complications after ventral hernia repair with prosthetic mesh were operated on again. Explanted mesh was examined for biofilm with confocal laser scanning microscopy (CLSM) and fluorescence in situ hybridization (FISH). In two cases, a novel molecular assay (the Ibis T5000) was used to characterize the biofilm-forming bacteria.

RESULTS

The CLSM examination demonstrated adherent biofilms on mesh surfaces in all five patients. Biofilms also were noted on investing fibrous tissue. The FISH study was able to discriminate between bacterial species in polymicrobial biofilms. In two patients the Ibis T5000 detected more species of constituent biofilm bacteria than did standard culture. Removal of the mesh and reconstruction with autologous tissues or biologic materials resolved the presenting complaints in all cases.

CONCLUSION

Bacterial biofilms should be considered an important contributor to the pathology and complications associated with prosthetic mesh implanted in the abdominal wall. If biofilms are present, complete removal of the mesh and repair of the resulting defect without alloplastic materials is an effective intervention.

Decreased hernia recurrence using autologous platelet-rich plasma (PRP) with Strattice™ mesh in a rodent ventral hernia model

BACKGROUND

Recurrence after ventral hernia repair (VHR) remains a multifactorial problem still plaguing surgeons today. Some of the many contributing factors include mechanical strain, poor tissue-mesh integration, and degradation of matrices. The high recurrence rate witnessed with the use of acellular dermal matrices (ADM) for definitive hernia repair has reduced their use largely to bridging repair and breast reconstruction. Modalities that improve classic cellular metrics of successful VHR could theoretically result in improved rates of hernia recurrence; autologous platelet-rich plasma (PRP) may represent one such tool, but has been underinvestigated for this purpose.

METHODS

Lewis rats (32) had chronic ventral hernias created surgically and then repaired with Strattice™ mesh alone (control) or mesh + autologous PRP. Samples were harvested at 3 and 6 months postoperatively and compared for gross, histologic, and molecular outcomes of: neovascularization, tissue incorporation, peritoneal adhesions, hernia recurrence, and residual mesh thickness.

RESULTS

Compared to control at 3 months postoperatively, PRP-treated rats displayed significantly more neovascularization of implanted mesh and considerable upregulation of both angiogenic genes (vEGF 2.73-fold, vWF 2.21-fold) and myofibroblastic genes (αSMA 9.68-fold, FSP-1 3.61-fold, Col1a1 3.32-fold, Col31a1 3.29-fold). Histologically, they also showed enhanced tissue deposition/ingrowth and diminished chronic immune cell infiltration. Peritoneal adhesions were less severe at both 3 (1.88 vs. 2.94) and 6 months (1.63 vs. 2.75) by Modified Hopkins Adhesion Scoring. PRP-treated rats experienced decreased hernia recurrence at 6 months (0/10 vs. 7/10) and had significantly improved ADM preservation as evidenced by quantification of residual mesh thickness.

CONCLUSIONS

PRP is an autologous source of pro-regenerative growth factors and chemokines uniquely suited to soft tissue wound healing. When applied to a model of chronic VHR, it incites enhanced angiogenesis, myofibroblast recruitment and tissue ingrowth, ADM preservation, less severe peritoneal adhesions, and diminished hernia recurrence. We advocate further investigation regarding PRP augmentation of human VHR.

Biomechanical properties of synthetic surgical meshes for pelvic prolapse repair

Synthetic meshes are widely used for surgical repair of different kind of prolapses. In the light of the experience of abdominal wall repair, similar prostheses are currently used in the pelvic region, to restore physiological anatomy after organ prolapse into the vaginal wall, that represent a recurrent dysfunction. For this purpose, synthetic meshes are surgically positioned in contact with the anterior and/or posterior vaginal wall, to inferiorly support prolapsed organs. Nonetheless, while mesh implantation restores physiological anatomy, it is often associated with different complications in the vaginal region. These potentially dangerous effects induce the surgical community to reconsider the safety and efficacy of mesh transvaginal placement. For this purpose, the evaluation of state-of-the-art research may provide the basis for a comprehensive analysis of mesh compatibility and functionality. The aim of this work is to review synthetic surgical meshes for pelvic organs prolapse repair, taking into account the mechanics of mesh material and structure, and to relate them with pelvic and vaginal tissue biomechanics. Synthetic meshes are currently available in different chemical composition, fiber and textile conformations. Material and structural properties are key factors in determining mesh biochemical and mechanical compatibility in vivo. The most significant results on vaginal tissue and surgical meshes mechanical characterization are here reported and discussed. Moreover, computational models of the pelvic region, which could support the surgeon in the evaluation of mesh performances in physiological conditions, are recalled.

An in vivo analysis of Miromesh--a novel porcine liver prosthetic created by perfusion decellularization

BACKGROUND

Bioprosthetics derived from human or porcine dermis and intestinal submucosa have dense, homogenous, aporous collagen structures that potentially limit cellular penetration, undermining the theoretical benefit of a "natural" collagen scaffold. We hypothesized that Miromesh-a novel prosthetic derived from porcine liver by perfusion decellularization-provides a more optimal matrix for tissue ingrowth.

METHODS

Thirty rats underwent survival surgery that constituted the creation of a 4 × 1 cm abdominal defect and simultaneous bridged repair. Twenty rats were bridged with Miromesh, and 10 rats were bridged with non-cross-linked porcine dermis (Strattice). Ten Miromesh and all 10 Strattice were rinsed in vancomycin solution and inoculated with 10(4) colony-forming units of green fluorescent protein-labeled Staphylococcus aureus (GFP-SA) after implantation. Ten Miromesh controls were neither soaked nor inoculated. No animals received systemic antibiotics. All animals were euthanized at 90 d and underwent an examination of their gross appearance before being sectioned for quantitative bacterial culture and histologic grading. A pathologist scored specimens (0-4) for cellular infiltration, acute inflammation, chronic inflammation, granulation tissue, foreign body reaction, and fibrous capsule formation.

RESULTS

All but one rat repaired with Strattice survived until the 90-d euthanization. All quantitative bacterial cultures for inoculated specimens were negative for GFP-SA. Of nine Strattice explants, none received a cellular infiltration score >0, consistent with a poor tissue-mesh interface observed grossly. Of 10 Miromesh explants also inoculated with GFP-SA, seven of 10 demonstrated cellular infiltration with an average score of +2.7 ± 0.8, whereas sterile Miromesh implants received an average score of 0.8 ± 1.0. Two inoculated Miromesh implants demonstrated acute inflammation and infection on histology.

CONCLUSIONS

A prosthetic generated from porcine liver by perfusion decellularization provides a matrix for superior cellular infiltration compared with non-cross-linked porcine dermis.

'Sandwich' technique in the treatment of large and complex incisional hernias

BACKGROUND

Reconstruction of large, complex abdominal wall hernias is an interesting challenge. Primary closure of those hernias is often not possible. There is little agreement about the most appropriate technique or prosthetic to repair these defects, in spite the fact of the prevalence of ventral hernias. Sometimes despite being contaminated surgical fields, we are often faced to reinforce with bio-prosthetic meshes. The component separation technique (CST) is a practical option; however, recurrence rates remain unacceptably high. In an attempt to reduce recurrences, we frequently added a biologic underlay mesh and a lightweight polypropylene on-lay mesh to the traditional CST. Our objective was to determine biologic mesh practice patterns of reconstructive surgeons with regard to indications, most appropriate technique, choice of prosthetics and experience with complications in order to work those hernias out.

METHODS

Thirty consecutive patients who underwent abdominal wall reconstruction by means of a component separations associated with non-cross-linked porcine dermal scaffolds (NCPDS) or a synthetic tissue scaffold (STS) reinforcement between October 2009 and December 2011 were retrospectively reviewed. Analysis of demographics, indications for NCPDS or STS placement, surgical technique, complications and follow-up data were performed. They underwent a 'sandwich' procedure with a biologic underlay mesh and a lightweight polypropylene on-lay mesh added to the traditional CST. We chose NCPDS or STS underlay mesh according to the fact of the presence or absence of a contaminated field.

RESULTS

A 'sandwich' procedure was used for abdominal wall repair in 30 patients. In all of them, NCPDS or STS was positioned using an intraperitoneal technique associated to a lightweight polypropylene on-lay mesh and the CST. At a mean follow-up time of 30.1 months, most patients had successful outcomes. Occurrences included seroma, recurrence and infection. One of our patients died from multi-organ failure unrelated to hernia repair.

CONCLUSIONS

This study shows that complex abdominal wall defects can be successfully reconstructed using a 'sandwich' procedure with a low rate of recurrence and occurrences. Moreover, repair of large, complex abdominal wall hernias by CST augmented with a biologic underlay mesh and a lightweight polypropylene on-lay mesh results in lower recurrence rates compared with historical reports of CST alone.

Complex ventral hernia repair with a human acellular dermal matrix and component separation: A case series

We present a case series of 19 patients requiring complex abdominal hernia repairs. Patients presented with challenging clinical histories with 95% having multiple significant comorbidities including overweight or obesity (84%), hypertension (53%), diabetes (42%), cancer (26%), and pulmonary disease (16%). The majority of patients (68%) had prior abdominal infections and 53% had at least one failed prior hernia repair. Upon examination, fascial defects averaged 282 cm². Anterior and posterior component separation was performed with placement of a human acellular dermal mesh. Midline abdominal closure under minimal tension was achieved primarily in all cases. Post-operative complications included 2 adverse events (11%) – one pulmonary embolism and one post-operative hemorrhage requiring transfusion; 6 wound-related complications (32%), 1 seroma (5%) and 1 patient with post-operative ileus (5%). Operative intervention was not required in any of the cases and most patients made an uneventful recovery. Increased patient age and longer OR time were independently predictive of early post-operative complications. At a median 2-year follow-up, three patients had a documented hernia recurrence (16%) and one patient was deceased due to unrelated causes.

Conclusion

Patients at high risk for post-operative events due to comorbidities, prior abdominal infection and failed mesh repairs do well following component separation reinforced with a human bioprosthetic mesh. Anticipated post-operative complications were managed conservatively and at a median 2-year follow-up, a low rate of hernia recurrence was observed with this approach.

•

Intraperitoneal placement of acellular dermal matrix using component separation.

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Acceptable recurrence rates of 16% at 2 years of follow up.

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Correlation in age and complication chances.

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Retrorectus technique possibly the best surgical technique for hernia repair.

Polypropylene and polypropylene/polyglecaprone (Ultrapro®) meshes in the repair of incisional hernia in rats

PURPOSE

To compare the inflammatory response of three different meshes on abdominal hernia repair in an experimental model of incisional hernia.

METHODS

Median fascial incision and skin synthesis was performed on 30 Wistar rats. After 21 days, abdominal hernia developed was corrected as follows: 1) No mesh; 2) Polypropylene mesh; and, 3) Ultrapro(r) mesh. After 21 days, the mesh and surrounding tissue were submitted to macroscopic (presence of adhesions, mesh retraction), microscopic analysis to identify and quantify the inflammatory and fibrotic response using a score based on a predefined scale of 0-3 degrees, evaluating infiltration of macrophages, giant cells, neutrophils and lymphocytes.

RESULTS

No significant difference was seen among groups in adherences, fibrosis, giant cells, macrophages, neutrophils or lymphocytes (p>0.05). Mesh shrinkage was observed in all groups, but also no difference was observed between polypropylene and Ultrapro mesh (7.0±9.9 vs. 7.4±10.1, respectively, p=0.967). Post-operatory complications included fistula, abscess, dehiscence, serohematic collection and reherniation, but with no difference among groups (p=0.363).

CONCLUSION

There is no difference between polypropylene (high-density) and Ultrapro(r) (low-density) meshes at 21 days after surgery in extraperitoneal use in rats, comparing inflammatory response, mesh shortening, adhesions or complications.

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

Preserving patients' native tissues has posed many challenges for surgeons. Increased life expectancy is leading to a proportionately older surgical population with weaker tissues. The growing population of morbidly obese patients in addition to those with multiple comorbidities which influence the native strength and perfusion of tissues compounds the surgeon's challenge. Certainly, there is a rising demand for materials to replace or augment a patient's native tissue when it has been compromised. Over time, the number of products available has increased substantially. The ideal substitute, however, is debatable. The manufacturing and processing of these materials has become more complex and this has resulted in a significant increase in cost. The composition of the mesh, clinical scenario, and operative technique all interact to impact the long-term results. Surgeons require a thorough understanding of these products to guide proper selection and use, to ensure optimal outcomes for patients, and to properly steward financial resources. This review will outline the properties of commonly used materials, highlighting the strength and weakness of each. It will then discuss recommendations regarding mesh selection, coding, and reimbursement. While general principles and trends can be highlighted, further studies of biologic versus synthetic meshes are clearly necessary.