Biological Implant for Complex Abdominal Wall Reconstruction: A Single Institution Experience and Review of Literature

Polyurethane-based three-dimensional printing for biological mesh carriers

Repair and reconstruction of the myopectineal orifice area using meshes is the mainstay of surgical treatment of inguinal hernias. However, the limitations of existing meshes are becoming increasingly evident in clinical applications; thus, the idea of using three-dimensionally (3D)-printed biological meshes was put forward. According to the current level of the 3D printing technology and the inherent characteristics of biological materials, the direct use of the 3D printing technology for making biological materials into finished products suitable for clinical applications is not yet supported, but synthetic materials can be first printed into 3D form carriers, compounded with biological materials, and finally made into finished products. The purpose of this study was to develop a technical protocol for making 3D-printed biomesh carriers using polyurethane as a raw material. In our study: raw material, polyurethane; weight, 20-30 g/m2; weaving method, hexagonal mesh; elastic tension aspect ratio, 2:1; diameters of pores, 0.1-1 mm; surface area, 8 × 12 cm2; the optimal printing layer height, temperature and velocity were 0.1 mm, 210-220 °C and 60 mm/s. Its clinical significance lies in: (1) applied to preoperative planning and design a detailed surgical plan; (2) applied to special types of surgery including patients in puberty, recurrent and compound inguinal hernias; (3) significantly improve the efficiency of doctor-patient communication; (4) it can shorten the operation and recovery period by about 1/3 and can save about 1/4 of the cost for patients; (5) the learning curve is significantly shortened, which is conducive to the cultivation of reserve talents.

The use of Permacol® biological mesh for complex abdominal wall repair

BACKGROUND

Complex abdominal wall repair (CAWR) remains challenging, especially in contaminated fields where the use of a synthetic mesh is associated with prohibitively complication rates. Consequently, biological mesh has been proposed as an alternative. The aim of our study was to evaluate the safety and efficacy of using Permacol® in patients who had CAWR.

METHODS

We retrospectively reviewed the files of patients who had CAWR using the Permacol® mesh. Analysis included patients' preoperative characteristics, procedural parameters, and early and late post-operative complications including mainly recurrence. A multivariate regression model was performed to determine factors that influence 24-months recurrence rate.

RESULTS

Between January 2009 and December 2018, 75 patients. The most common indication was hernia in a contaminated field (48.0%) and abdominal wall defect greater than 10 cm in diameter (36%). Overall, 44% of our patients were Centers for Disease Control (CDC) class II or III and 81.3% fall into category II or III according to the Ventral Hernia Working Group (VHWG) classification. Recurrence rate of our series was 9.3%. Complete fascial closure was achieved in 60 patients (80%). Upon univariate analysis complete fascial closure, posterior component separation, seroma drainage, BMI >30 kg/m2 and age >65 years, VHWD grade >2, DINDO CLAVIEN class > 2 affected the recurrence rate at 2 years follow up. When subcutaneous drains are placed prophylactically, recurrence rates drop from 38.7% (5/14) to 3.3% (2/61 patients) when drains are placed at the time of operation (p=0.02). Only fascial closure affected the 24-months recurrence rate on multivariate analysis (p<0.001).

CONCLUSIONS

Permacol® surgical implant use for CAWR is safe with a relatively low rate of hernia recurrence at 2 years. Prophylactic subcutaneous drain placement may reduce the risk of hernia recurrence. The presence of contaminated fields does not appear to influence hernia recurrence when Permacol® is used, in fact, the only factor that affects recurrence rate at 24-months on multivariate analysis is completeness of the fascial closure.

Long-Term Outcomes in Complex Abdominal Wall Reconstruction Repaired With Absorbable Biologic Polymer Scaffold (Poly-4-Hydroxybutyrate)

Introduction

After promising early outcomes in the use of absorbable biologic mesh for complex abdominal wall reconstruction, significant criticism has been raised over the longevity of these repairs after its 2-year resorption profile.

Methods

This is the long-term (5-year) follow-up analysis of our initial experience with the absorbable polymer scaffold poly-4-hydroxybutyrate (P4HB) mesh compared with a consecutive contiguous group treated with porcine cadaveric mesh for complex abdominal wall reconstructions. Our clinical analysis was performed using Stata 14.2 and Excel 16.16.23.

Results

After a 5-year follow-up period, the P4HB group (n = 31) experienced lower rates of reherniation (12.9% vs 38.1%; P = 0.017) compared with the porcine cadaveric mesh group (n = 42). The median interval in months to recurrent herniation was similar between groups (24.3 vs 20.8; P = 0.700). Multivariate logistic regression analysis on long-term outcomes identified smoking (P = 0.004), African American race (P = 0.004), and the use of cadaveric grafts (P = 0.003) as risks for complication while smoking (P = 0.034) and the use of cadaveric grafts (P = 0.014) were identified as risks for recurrence. The long-term cost analysis showed that P4HB had a $10,595 per case costs savings over porcine cadaveric mesh.

Conclusions

Our study identified the superior outcomes in clinical performance and a value-based benefit of absorbable biologic P4HB scaffold persisted after the 2-year resorption timeframe. Data analysis also confirmed the use of porcine cadaveric grafts independently contributed to the incidence of complications and recurrences.

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.

Chinese expert consensus on adult ventral abdominal wall defect repair and reconstruction

BACKGROUND

Surgical management of patients with ventral abdominal wall defects, especially complex abdominal wall defects, remains a challenging problem for abdominal wall reconstructive surgeons. Effective surgical treatment requires appropriate preoperative assessment, surgical planning, and correct operative procedure in order to improve postoperative clinical outcomes and minimize complications. Although substantial advances have been made in surgical techniques and prosthetic technologies, there is still insufficient high-level evidence favoring a specific technique. Broad variability in existing practice patterns, including clinical pre-operative evaluation, surgical techniques and surgical procedure selection, are still common.

DATA SOURCES

With the purpose of providing a best practice algorithm, a comprehensive search was conducted in Medline and PubMed. Sixty-four surgeons considered as experts on abdominal wall defect repair and reconstruction in China were solicited to develop a Chinese consensus and give recommendations to help surgeons standardize their techniques and improve clinical results.

CONCLUSIONS

This consensus serves as a starting point to provide recommendations for adult ventral abdominal wall repair and reconstruction in China and may help build opportunities for international cooperation to refine AWR practice.

3D Reconstruction Model of an Extra-Abdominal Desmoid Tumor: A Case Study

In recent years, three-dimensional reconstruction (3DR) models have become a standard tool in several medical fields such as education, surgical training simulation, patient–doctor communication, and surgical planning. Postoncologic reconstructive surgery in thoracic diseases might benefit from 3DR models; however, limited data on this application have been published worldwide. In this paper, the aim was to report our experience with 3DR modeling to determine resection and plan the surgical reconstruction in a patient with a desmoid tumor of the chest wall. For a better understanding of the case study, we describe all the steps from acquiring computed tomography (CT) scans to the final 3D rendering. A 68-year-old, non-smoking man presented at our outpatient department with painless swelling of the right anterobasal chest wall. A thorax–abdomen–brain CT scan revealed homogenous solid tissue with a dense mass measuring 80 mm × 62 mm. The final 3D model was evaluated by the surgical team (three medical doctors), who found the model to be powerful. Based on the results and the accuracy of the model, the multidisciplinary team decided that the tumor was resectable. Consequently, a surgical plan based on the 3D model was developed to perform chest wall reconstruction after radical resection. The patient underwent right anterolateral thoracotomy at the seventh intercostal space, which confirmed the CT scan findings and revealed infiltration of the serratus muscle and medial portion of the diaphragm. A radical tumor en bloc resection with chest wall and diaphragm resection was performed. The full-thickness chest wall and diaphragm defects were reconstructed using two separate biological patches of a porcine dermal collagen implant (Permacol™ Surgical Implant). Postoperative X-ray revealed unremarkable findings; the patient had an uneventful recovery and was discharged 6 days after surgery. This case study illustrates that 3DR models enable a personalized approach to the treatment of desmoid tumors. Therefore, this approach should be developed further and studied systematically.

A retrospective, Italian multicenter study of complex abdominal wall defect repair with a Permacol biological mesh

Complex abdominal wall defects (CAWDs) can be difficult to repair and using a conventional synthetic mesh is often unsuitable. A biological mesh might offer a solution for CAWD repair, but the clinical outcomes are unclear. Here, we evaluated the efficacy of a cross-linked, acellular porcine dermal collagen matrix implant (Permacol) for CAWD repair in a cohort of 60 patients. Here, 58.3% patients presented with a grade 3 hernia (according to the Ventral Hernia Working Group grading system) and a contaminated surgical field. Permacol was implanted as a bridge in 46.7%, as an underlay (intraperitoneal position) in 38.3% and as a sublay (retromuscolar position) in 15% of patients. Fascia closure was achieved in 53.3% of patients. The surgical site occurrence rate was 35% and the defect size significantly influenced the probability of post-operative complications. The long-term (2 year) hernia recurrence rate was 36.2%. This study represents the first large multi-centre Italian case series on Permacol implants in patients with a CAWD. Our data suggest that Permacol is a feasible strategy to repair a CAWD, with acceptable early complications and long-term (2 year) recurrence rates.