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

Emerging materials and technologies for advancing bioresorbable surgical meshes

Surgical meshes play a significant role in the treatment of various medical conditions, such as hernias, pelvic floor issues, guided bone regeneration, and wound healing. To date, commercial surgical meshes are typically made of non-absorbable synthetic polymers, notably polypropylene and polytetrafluoroethylene, which are associated with postoperative complications, such as infections. Biological meshes, based on native tissues, have been employed to overcome such complications, though mechanical strength has been a main disadvantage. The right balance in mechanical and biological performances has been achieved by the advent of bioresorbable meshes. Despite improvements, recurrence of clinical complications associated with surgical meshes raises significant concerns regarding the technical adequacy of current materials and designs, pointing to a crucial need for further development. To this end, current research focuses on the design of meshes capable of biomimicking native tissue and facilitating the healing process without post-operative complications. Researchers are actively investigating advanced bioresorbable materials, both synthetic polymers and natural biopolymers, while also exploring the performance of therapeutic agents, surface modification methods and advanced manufacturing technologies such as 4D printing. This review seeks to evaluate emerging biomaterials and technologies for enhancing the performance and clinical applicability of the next-generation surgical meshes. STATEMENT OF SIGNIFICANCE: In the ever-transforming landscape of regenerative medicine, the embracing of engineered bioabsorbable surgical meshes stands as a key milestone in addressing persistent challenges and complications associated with existing treatments. The urgency to move beyond conventional non-absorbable meshes, fraught with post-surgery complications, emphasises the necessity of using advanced biomaterials for engineered tissue regeneration. This review critically examines the growing field of absorbable surgical meshes, considering their potential to transform clinical practice. By strategically combining mechanical strength with bioresorbable characteristics, these innovative meshes hold the promise of mitigating complications and improving patient outcomes across diverse medical applications. As we navigate the complexities of modern medicine, this exploration of engineered absorbable meshes emerges as a promising approach, offering an overall perspective on biomaterials, technologies, and strategies adopted to redefine the future of surgical meshes.

The increased angiogenic capacity and decreased inflammatory response when a mesh is used in combination with an omental flap. A prospective experimental study

BACKGROUND

The use of a surgical mesh for abdominal wall reconstruction is well established and has been used for long with minor complications, whereas the omental flap has been used for decades in reconstructive surgery.

AIM

To demonstrate the increased angiogenic capacity and the reduced inflammatory markers of a synthetic mesh when used in combination with an omental flap. Furthermore, we compare two independent meshes when used alone or in combination with the omental flap.

MATERIALS AND METHODS

Twenty-eight rats were included in the study. To determine the effect of using an omental flap under two different meshes, the animals were separated into four groups, i.e., group A (flap + mesh 1), group B (flap + mesh 1 + silicone), group C (flap + mesh 2), and group D (flap + mesh 2 + silicone). A silicone sheet was placed as a barrier between the mesh and the flap. All groups were sacrificed 8 weeks post-operatively.

RESULTS

The use of a silicone sheet barrier between any of the two synthetic meshes and the omental flap in an abdominal wall defect is accompanied by a markedly reduced angiogenesis in terms of a cluster of differentiation (CD)-34 (p < 0.001) and factor VIII (p = 0.0012) and by increased inflammatory response CD-68 (p = 0.0024) and visual scoring (p < 0.001).

CONCLUSIONS

Τhe increased angiogenic capacity and the reduced inflammatory markers of a synthetic surgical mesh when used in combination with an omental flap make it a useful option in the reconstruction of an abdominal wall defect on a large or contaminated wound.

Abdominal wall hernia repair: from prosthetic meshes to smart materials

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

Tissue-Adhesive Decellularized Extracellular Matrix Patches Reinforced by a Supramolecular Gelator to Repair Abdominal Wall Defects

Implantation of surgical meshes composed of synthetic and biological materials has been applied for abdominal wall defect repair. Despite many efforts, there are no reliable meshes that fully satisfy clinical requirements because of their lack of biodegradability, mechanical strength, and tissue-adhesive properties. Here, we report biodegradable, decellularized extracellular matrix (dECM)-based biological patches to treat abdominal wall defects. By incorporating a water-insoluble supramolecular gelator that forms physical cross-linking networks through intermolecular hydrogen bonding, dECM patches were reinforced to improve mechanical strength. Reinforced dECM patches possessed higher tissue adhesion strength and underwater stability compared with the original dECM because of enhanced interfacial adhesion strength. In vivo experiments using an abdominal wall defect rat model showed that reinforced dECM patches induced collagen deposition and the formation of blood vessels during material degradation, and the accumulation of CD68-positive macrophages was suppressed compared to nonbiodegradable synthetic meshes. Tissue-adhesive and biodegradable dECM patches with improved mechanical strength by a supramolecular gelator have enormous potential for use in the repair of abdominal wall defects.

Development of a conceptual framework for reporting modifications in surgical innovation: scoping review

BACKGROUND

Innovative surgical procedures and devices are often modified throughout their development and introduction into clinical practice. A systematic approach to reporting modifications may support shared learning and foster safe and transparent innovation. Definitions of 'modifications', and how they are conceptualized and classified so they can be reported and shared effectively, however, are lacking. This study aimed to explore and summarize existing definitions, perceptions, classifications and views on modification reporting to develop a conceptual framework for understanding and reporting modifications.

METHODS

A scoping review was conducted in accordance with PRISMA Extension for Scoping Reviews (PRISMA-ScR) guidelines. Targeted searches and two database searches were performed to identify relevant opinion pieces and review articles. Included were articles relating to modifications to surgical procedures/devices. Data regarding definitions, perceptions and classifications of modifications, and views on modification reporting were extracted verbatim. Thematic analysis was undertaken to identify themes, which informed development of the conceptual framework.

RESULTS

Forty-nine articles were included. Eight articles included systems for classifying modifications, but no articles reported an explicit definition of modifications. Some 13 themes relating to perception of modifications were identified. The derived conceptual framework comprises three overarching components: baseline data about modifications, details about modifications and impact/consequences of modifications.

CONCLUSION

A conceptual framework for understanding and reporting modifications that occur during surgical innovation has been developed. This is a first necessary step to support consistent and transparent reporting of modifications, to facilitate shared learning and incremental innovation of surgical procedures/devices. Testing and operationalization is now needed to realize the value of this framework.

In Situ Cross-Linked Collagen-Based Biological Patch Integrating Anti-Infection and Anti-Calcification Properties

Acellular dermal matrix (ADM) can be used as collagen-based biological patches for regeneration and repair of soft tissues in vivo. However, the problems of calcification and infection during treatment with patches can lead to premature patch failure and even to a severely increased risk of recurrence. In this study, first, porcine ADM (pADM) grafted with vinyl underwent an in situ cross-linking reaction in the presence of an initiator, while quaternary ammonium groups were introduced into the pADM during the cross-linking process to obtain MA-DMC-pADM, which is a biological patch with anti-infection and anti-calcification properties. The results of physicochemical property tests of the material showed that the pADM after cross-linking had better physical and mechanical properties. Importantly, antibacterial and anti-calcification experiments showed that MA-DMC-pADM had a good antibacterial and anti-calcification effect. Therefore, the MA-DMC-pADM biological patch facilitates their longer-lasting effectiveness, allowing pADM to be used in a wider range of applications.

Comparison of Hybrid Versus Synthetic Mesh in Robotic Rives-Stoppa Ventral Hernia Repair

Background and Objectives

To estimate the average treatment effect on the treated (ATT) and to assess the clinical outcomes in two different types of mesh in robotic Rives-Stoppa (rRS) ventral hernia repair (VHR).

Methods

A retrospective analysis of a robotic VHR database between February 1, 2013 and May 31, 2022. Patients who underwent a rRS VHR were included in this study and separated into two groups depending on the mesh used: Synecor^TM Preperitoneal Biomaterial (Synecor^TM Pre) and Bard™ Soft. Through propensity score and inverse-probability-treatment-weighting, the ATT was estimated for two scenarios; the first with the treated target having used the Synecor^TM Pre, the second having used the Bard™ Soft mesh. Adjusted linear regression models, including lingering imbalanced variables, were used for both the primary outcome of the Comprehensive Complication Index (CCI®), and the secondary outcome of the hospital cost.

Results

A total of 186 patients who underwent rRS were separated into the two groups (Synecor^TM Pre mesh, n = 85; Bard™ Soft mesh, n = 101). Adjusted linear regression models for the CCI showed no statistical difference between both groups (p > 0.05), whereas ATT on hospital cost was significantly higher (p < 0.001) in the Synecor^TM Pre group in both scenarios [(95% confidence interval) = 3882 (2352, 5413) and -5185 (-8213, -2157), respectively].

Conclusion

Both mesh materials provided excellent outcomes with no difference in complications or recurrence rates. However, hospital cost was found to be higher in the hybrid mesh group. Long-term follow-up is needed to fully assess the performance of both mesh types in rRS.

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.

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.

Systematic Review of Innovation Reporting in Endoscopic Sleeve Gastroplasty

BACKGROUND

Endoscopic sleeve gastroplasty (ESG) is a novel endoscopic procedure used to treat obesity-related comorbidities. Whilst its use is increasing in clinical practice, there is comparatively little understanding about how it has been evaluated. This study aimed to systematically summarize and appraise the reporting of ESG in the context of guidelines for evaluating innovative surgical devices and procedures.

METHODS

Systematic searches were used to identify all published studies reporting ESG insertion. Data collected included patient selection, governance arrangements, proceduralist expertise, technique description and outcome reporting.

RESULTS

Searches identified 2289 abstracts; 37 full-text papers were included (one prospective comparative cohort study, 16 retrospective cohort studies, 17 prospective cohort studies and three case reports). No randomized trials were identified. Eighteen studies were conducted prospectively. The number of patients in the included studies ranged from 1 to 1000. The lower BMI limit ranged from 27 to 35 kg/m². Research approvals were reported in 26 studies. Two studies reported on the learning curve. All studies reported some aspect of technical implementation, but many variations were noted. Suturing device used and suture pattern were the most commonly reported aspects (32 studies). Follow-up ranged from 1 to 24 months, but was 12 months or less in 28 studies. Forty-eight different outcomes were reported across all studies.

CONCLUSION

The literature on ESG has demonstrated some progression in reporting and analysis and the next stage of assessment should be a randomized controlled trial to demonstrate efficacy.

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.

Surgical site infection in mesh repair for ventral hernia in contaminated field: A systematic review and meta-analysis

Background

Given the risk of surgical site infection (SSI), the use of mesh in contaminated ventral hernia repair (VHR) is not standardized and still a clinical dilemma. This meta-analysis aimed to assess whether mesh use increased the risk of SSI in patients following VHR in contaminated field.

Methods

We performed a systematic review of published literature. Studies comparing the mesh repair and anatomic repair, the use of mesh in different Center for Disease Control and Prevention (CDC) wound classes and mesh repair with synthetic mesh or other type of meshes to treat complicated and contaminated VHR were considered for analysis. The main outcome was SSI incidence.

Results

Six studies compared mesh and suture repairs. No significant difference in SSI incidence was observed between patients with complicated VHR in the mesh and suture repair groups.Five studies analyzed mesh repair in patients by field contamination level. There was no significant difference between the use of mesh in clean-contaminated, contaminated and dirty field versus clean wound class. Moreover, there was no significant difference between the use of mesh in clean-contaminated and contaminated cases.Four studies compared mesh repair technique with synthetic mesh or other type of meshes were included. The incidence of SSI was significantly lower in the synthetic mesh group.

Conclusions

The use of mesh repair in the management of complicated VHR compared to suture repair is not associated with an increased incidence of SSI even in potentially contaminated fields.

Regulatory science for hernia mesh: Current status and future perspectives

Regulatory science for medical devices aims to develop new tools, standards and approaches to assess the safety, effectiveness, quality and performance of medical devices. In the field of biomaterials, hernia mesh is a class of implants that have been successfully translated to clinical applications. With a focus on hernia mesh and its regulatory science system, this paper collected and reviewed information on hernia mesh products and biomaterials in both Chinese and American markets. The current development of regulatory science for hernia mesh, including its regulations, standards, guidance documents and classification, and the scientific evaluation of its safety and effectiveness was first reported. Then the research prospect of regulatory science for hernia mesh was discussed. New methods for the preclinical animal study and new tools for the evaluation of the safety and effectiveness of hernia mesh, such as computational modeling, big data platform and evidence-based research, were assessed. By taking the regulatory science of hernia mesh as a case study, this review provided a research basis for developing a regulatory science system of implantable medical devices, furthering the systematic evaluation of the safety and effectiveness of medical devices for better regulatory decision-making. This was the first article reviewing the regulatory science of hernia mesh and biomaterial-based implants. It also proposed and explained the concepts of evidence-based regulatory science and technical review for the first time.

Biologic Mesh in Surgery: A Comprehensive Review and Meta-Analysis of Selected Outcomes in 51 Studies and 6079 Patients

BACKGROUND

In recent decades, biologic mesh (BM) has become an important adjunct to surgical practice. Recent evidence-based clinical applications of BM include but are not limited to: reconstruction of abdominal wall defects; breast reconstruction; face, head and neck surgery; periodontal surgery; other hernia repairs (diaphragmatic, hiatal/paraesophageal, inguinal and perineal); hand surgery; and shoulder arthroplasty. Prior systematic reviews of BM in complex abdominal wall hernia repair had several shortcomings that our comprehensive review seeks to address, including exclusion of laparoscopic repair, assessment of risk of bias, use of an acceptable meta-analytic method and review of risk factors identified in multivariable regression analyses.

MATERIALS AND METHODS

We sought articles of BM for open ventral hernia repair reporting on early complications, late complications or recurrences and included minimum of 50. We used the quality in prognostic studies risk of bias assessment tool. Random effects meta-analysis was applied.

RESULTS

This comprehensive review selected 62 articles from 51 studies that included 6,079 patients. Meta-analytic pooling found that early complications are present in about 50%, surgical site occurrences (SSOs) in 37%, surgical site infections (SSIs) in 18%, reoperation in 7%, readmission in 20% and mortality in 3%. Meta-analytic estimates of late outcomes included overall complications (42%), SSOs (40%) and SSIs (22%). Specific SSOs included seroma (14%), hematoma (4%), abscess (10%), necrosis (5%), dehiscence (8%) and fistula formation (5%). Reoperation occurred in about 17%, mesh explantation in 9% and recurrence in 36%.

CONCLUSION

Estimates of nearly all outcomes from individual studies were highly heterogeneous and sensitivity analyses and meta-regressions generally failed to explain this heterogeneity. Recurrence is the only outcome for which there are consistent findings for risk factors. Bridge placement of BM is associated with higher risk of recurrence. Prior hernia repair, history of reintervention and history of mesh removal were also risk factors for increased recurrence.

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

SUMMARY

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

Systematic review and meta-analysis of factors associated with post-operative pancreatic fistula following pancreatoduodenectomy

BACKGROUND

Many studies have explored factors relating to post-operative pancreatic fistula (POPF); however, the original definition (All-POPF) was revised to include only 'clinically relevant' (CR) POPF. This study identified variables associated with the two International Study Group on Pancreatic Surgery definitions to identify which variables are more strongly associated with CR-POPF.

METHODS

A systematic review identified all studies reporting risk factors for POPF (using both International Study Group on Pancreatic Fistula definitions) following pancreatoduodenectomy. The primary outcome was factors associated with CR-POPF. Meta-analyses (random effects models) of pre-, intra- and post-operative factors associated with POPF in more than two studies were included.

RESULTS

Among 52 774 patients All-POPF (n = 69 studies) and CR-POPF (n = 53 studies) affected 27% (95% confidence interval (CI_95% ) 23-30) and 19% (CI_95% 17-22), respectively. Of the 176 factors, 24 and 17 were associated with All- and CR-POPF, respectively. Absence of pre-operative pancreatitis, presence of renal disease, no pre-operative neoadjuvant therapy, use of post-operative somatostatin analogues, absence of associated venous or arterial resection were associated with CR-POPF but not All-POPF.

CONCLUSION

In conclusion this study demonstrates wide variation in reported rates of POPF and that several risk factors associated with CR-POPF are not used within risk prediction models. Data from this study can be used to shape future studies, research and audit across ethnic and geographic boundaries in POPF following pancreatoduodenectomy.

Critical appraisal of gastric conduit ischaemic conditioning (GIC) prior to oesophagectomy: A systematic review and meta-analysis

INTRODUCTION

Anastomotic leaks remain a major complication following oesophagectomy, accounting for high morbidity and mortality. Recently, gastric ischaemic conditioning (GIC) has been proposed to improve anastomotic integrity through neovascularisation of the gastric conduit. This systematic review and meta-analysis aim to determine the impact of GIC on postoperative outcomes following oesophagectomy.

METHODS

A systematic literature search was performed to identify studies reporting GIC for any indication of oesophageal resection up to April 25, 2019. The primary outcome was anastomotic leak. Secondary outcomes were conduit necrosis, anastomotic strictures, overall and major complications or in-hospital mortality. Meta-analyses were conducted using random-effects modelling.

RESULTS

Nineteen studies reported on GIC, of which 13 were comparative studies. GIC was performed through ligation in 13 studies and embolisation in six studies. GIC did not appear to reduce anastomotic leakages (OR 0.80, CI_95: 0.51-1.24, p = 0.3), anastomotic strictures (OR 0.75, CI_95: 0.35-1.60, p = 0.5), overall complications (OR 1.02, CI_95: 0.48-2.16, p = 0.9), major complications (OR 1.06, CI_95: 0.53-2.11, p = 0.9), or in-hospital mortality (OR 0.70, CI_95: 0.32-1.53, p = 0.4). However, GIC was associated with reduced rates of conduit necrosis (OR 0.30, CI_95: 0.11-0.77, p = 0.013).

CONCLUSION

GIC does not appear to reduce overall rates of anastomotic leakage after oesophagectomy but seems to reduce severity of leakages. More in depth studies are recommended.

Prophylactic biological mesh reinforcement versus standard closure of stoma site (ROCSS): a multicentre, randomised controlled trial

BACKGROUND

Closure of an abdominal stoma, a common elective operation, is associated with frequent complications; one of the commonest and impactful is incisional hernia formation. We aimed to investigate whether biological mesh (collagen tissue matrix) can safely reduce the incidence of incisional hernias at the stoma closure site.

METHODS

In this randomised controlled trial (ROCSS) done in 37 hospitals across three European countries (35 UK, one Denmark, one Netherlands), patients aged 18 years or older undergoing elective ileostomy or colostomy closure were randomly assigned using a computer-based algorithm in a 1:1 ratio to either biological mesh reinforcement or closure with sutures alone (control). Training in the novel technique was standardised across hospitals. Patients and outcome assessors were masked to treatment allocation. The primary outcome measure was occurrence of clinically detectable hernia 2 years after randomisation (intention to treat). A sample size of 790 patients was required to identify a 40% reduction (25% to 15%), with 90% power (15% drop-out rate). This study is registered with ClinicalTrials.gov, NCT02238964.

FINDINGS

Between Nov 28, 2012, and Nov 11, 2015, of 1286 screened patients, 790 were randomly assigned. 394 (50%) patients were randomly assigned to mesh closure and 396 (50%) to standard closure. In the mesh group, 373 (95%) of 394 patients successfully received mesh and in the control group, three patients received mesh. The clinically detectable hernia rate, the primary outcome, at 2 years was 12% (39 of 323) in the mesh group and 20% (64 of 327) in the control group (adjusted relative risk [RR] 0·62, 95% CI 0·43-0·90; p=0·012). In 455 patients for whom 1 year postoperative CT scans were available, there was a lower radiologically defined hernia rate in mesh versus control groups (20 [9%] of 229 vs 47 [21%] of 226, adjusted RR 0·42, 95% CI 0·26-0·69; p<0·001). There was also a reduction in symptomatic hernia (16%, 52 of 329 vs 19%, 64 of 331; adjusted relative risk 0·83, 0·60-1·16; p=0·29) and surgical reintervention (12%, 42 of 344 vs 16%, 54 of 346: adjusted relative risk 0·78, 0·54-1·13; p=0·19) at 2 years, but this result did not reach statistical significance. No significant differences were seen in wound infection rate, seroma rate, quality of life, pain scores, or serious adverse events.

INTERPRETATION

Reinforcement of the abdominal wall with a biological mesh at the time of stoma closure reduced clinically detectable incisional hernia within 24 months of surgery and with an acceptable safety profile. The results of this study support the use of biological mesh in stoma closure site reinforcement to reduce the early formation of incisional hernias.

FUNDING

National Institute for Health Research Research for Patient Benefit and Allergan.

Autologous abdominal wall reconstruction using anterolateral thigh and iliotibial tract flap after extensive tumor resection: A case series study of 50 consecutive cases

BACKGROUND

The utility of anterolateral thigh (ALT) + iliotibial tract (ITT) flaps for the reconstruction of large abdominal wall defects has been reported, especially in cases with huge skin defects, surgical contamination, or a history of radiotherapy. However, previous reports have mainly described short-term results such as flap success rates or incidence of wound complications. The present study reviewed 50 consecutive cases of abdominal wall reconstruction using an ALT+ITT flap after extensive tumor resection and evaluated the durability of this approach (incidence of bulge or hernia) and the factors affecting the results.

PATIENTS AND METHODS

A detailed retrospective review of 50 consecutive cases was conducted. Computed tomography or magnetic resonance imaging findings were reviewed to assess the incidence of abdominal bulge or hernia. Items extracted as variables from patient records were subjected to univariate and multivariate logistic regression analyses to identify their relationship with postoperative abdominal bulge or hernia.

RESULTS

Forty-six cases that were followed up for more than six months were analyzed. Twenty-three patients (50.0%) developed abdominal bulge, while none (0%) developed hernia. The multivariate logistic regression analysis revealed that old age and a high body mass index were independently associated with abdominal bulge, while abdominal defect size was not.

CONCLUSIONS

Abdominal wall reconstruction using an ALT+ITT flap after extensive tumor resection was considered a reasonable option with a low risk of hernia despite a marked incidence of postoperative abdominal bulge; however, the usage of additional material may be considered depending on the situation.

Is water-soluble contrast enema examination for integrity of rectal anastomosis necessary prior to ileostomy reversal?

Background and Aim

Routine use of water-soluble contrast enema (WSCE) to assess anastomotic integrity is debated. This study aimed to evaluate the role of WSCE to assess anastomotic integrity following anterior resections (AR) with defunctioning stoma prior to reversal and identify factors to limit its selective use.

Methods

This retrospective study evaluated all WSCE performed over a 7-year period at a high-volume colorectal unit. Risk factors for radiological abnormality/leak, including malignancy, chemoradiotherapy, and immediate postoperative complications, were recorded. A gastrointestinal specialist radiologist and surgeon validated all WSCEs reported as abnormal.

Results

Of the 486 WSCE studies identified, 92 were excluded (repeat studies (n = 51), pediatric cases [n = 2], no AR [n = 39]). A total of 394 WSCE studies were evaluated (260 cancer; 134 noncancer patients); 14% (37/260) of cancer patients and 8% (10/134) of noncancer patients had abnormal studies (P = 0.072). Of the 37 abnormal studies in cancer patients, 73% (27/37) radiological leaks were found, and 41% (n = 11/27) of these patients had postoperative complications. Of the 10 abnormal studies in noncancer patients, 20% (2/10) radiological leaks were found, but none of these patients had postoperative complications. Overall leak rates were 7% (29/394), and rates were significantly higher in cancer patients than noncancer patients (10 vs 2%, P = 0.005).

Conclusion

Routine use of WSCE may not be necessary prior to reversal. WSCE should be selectively used in event of postoperative leak or complications. Noncancer resections are less likely demonstrate a leak.

Evaluation of decellularization protocols for production of porcine small intestine submucosa for use in abdominal wall reconstruction

BACKGROUND

Porcine-derived acellular biologic grafts are increasingly used in abdominal wall reconstruction and other soft tissue repairs. In a previous work, we have shown porcine small intestine submucosa (PSIS) exhibits clear advantages over porcine pericardium (PPC) and porcine acellular dermal matrix (PADM) in repairing full-thickness abdominal wall defects. In the present study, we aim to determine, quantify, and compare the effects of two most commonly used decellularization protocols on biomechanical and biocompatible properties of PSIS.

MATERIALS AND METHODS

After mechanical preparation, PSIS was treated with either alkaline and acid (AA) protocol or sodium dodecyl sulfate (SDS) protocol. Cellular content removal, preservation of matrix components, micro- and ultra- structures, and mechanical properties were compared. The host responses were evaluated using PSIS for repairing rat abdominal wall defects.

RESULTS AND CONCLUSION

With regard to the absence of cellular contents, neatly arranged collagen fiber structures, better retention of growth factors, better mechanical strength, lower degrees of local and systemic inflammatory responses, higher degree of vascularization and tissue ingrowth, alkaline and acid protocol exhibits clear advantages over SDS protocol for the preparation of PSIS extracellular matrix.

Biocellulose for Incisional Hernia Repair-An Experimental Pilot Study

Ventral or incisional hernia are a common disease pattern in general surgery. Most commonly, a mesh repair is used for reconstruction, whereby the mesh itself might cause complications, like infections or adhesions. Biological materials, like biocellulose, might reduce these clinical problems substantially. In this prospective rodent study, a biocellulose mesh (produced by Gluconacetobacter xylinus) was implanted either by a sublay technique or as supplementation of the abdominal wall. After an observation period of 90 days, animals were sacrificed. The adhesions after the reconstruction of the abdominal wall were moderate. The histologic investigations revealed that the biocellulose itself was inert, with a minimal regenerative response surrounding the mesh. The explanted mesh showed a minimal shrinkage (around 15%) as well as a minimal loss of tear-out force, which might be without clinical relevance. This is the first in vivo study describing biocellulose as a suitable mesh for the repair of ventral hernia in two different hernia models. The material seems to be a promising option for solving actual problems in modern hernia surgery.