First human magnetic resonance visualisation of prosthetics for laparoscopic large hiatal hernia repair

Preparation and Biocompatibility Study of Contrast-Enhanced Hernia Mesh Material

BACKGROUND

Meshes play a crucial role in hernia repair. However, the displacement of mesh inevitably leads to various associated complications. This process is difficult to be traced by conventional imaging means. The purpose of this study is to create a contrast-enhanced material with high-density property that can be detected by computed tomography (CT).

METHODS

The contrast-enhanced monofilament was manufactured from barium sulfate nanoparticles and medical polypropylene (PP/Ba). To characterize the composite, stress tensile tests and scanning electron microscopy (SEM) was performed. Toxicity and biocompatibility of PP/Ba materials was verified by in vitro cellular assays. Meanwhile, the inflammatory response was tested by protein adsorption assay. In addition, an animal model was established to demonstrate the long-term radiographic effect of the composite material in vivo. Subsequent pathological tests confirmed its in vivo compatibility.

RESULTS

The SEM revealed that the main component of the monofilament is carbon. In vitro cell experiments demonstrated that novel material does not affect cell activity and proliferation. Protein adsorption assays indicated that the contrast-enhanced material does not cause additional inflammatory responses. In addition, in vivo experiments illustrated that PP/Ba mesh can be detected by CT and has good in vivo compatibility.

CONCLUSION

These results highlight the excellent biocompatibility of the contrast-enhanced material, which is suitable for human abdominal wall tissue engineering.

Surgical and radiological behavior of MRI-depictable mesh implants after TAPP repair: the IRONMAN study

PURPOSE

Knowledge of postoperative behavior of mesh implants used for hernia repair is generally limited to cases of recurrence, local complications or return to the previous operative field in other pathological conditions. Previous studies with MRI-visible mesh implants in different parts of the abdominal wall have led to variable findings with regard to mesh properties and mostly described a reduction in size over time with subsequently limited mesh overlap over hernia defects which could contribute to recurrence. We aimed to evaluate implant properties in a mechanically stable anatomical region after TAPP repair of primary unilateral inguinal hernias in men with clinical and MRI examinations 4 weeks and 1 year after surgery.

METHODS

From 11/2015 to 01/2019, 23 men with primary, unilateral, inguinal hernias underwent TAPP repair with iron particle-loaded, MRI-visible mesh implants in a prospective cohort study. In 16 patients the operative outcome could be evaluated 4 weeks and 12 months after surgery by clinical examination and MRI evaluation with regard to postoperative course, possible adverse outcomes and radiological findings related to implant behavior-namely MRI-identifiability, mesh dislocation or reduction in surface area.

RESULTS

All included patients had an uneventful postoperative clinical course. MRI after 4 weeks revealed one postoperative seroma, which resolved spontaneously. No recurrence was detected. Mesh implants could be accurately delineated in DIXON-IN studies and showed neither clinically nor statistically significant changes in size or position.

CONCLUSION

4 weeks and 1 year after a standardized TAPP procedure the mesh implant used in this study showed no tendency towards dislocation or reduction in size in this anatomical position. Its MRI visibility allows accurate delineation during the postoperative course by experienced radiologists in appropriate MRI protocols. Larger patient series are desirable to further support these findings. Shrinkage of implants in the groin as a reason for early recurrence may be overestimated.

Follow Up Data of MRI-Visible Synthetic Meshes for Reinforcement in Large Hiatal Hernia in Comparison to None-Mesh Repair-A Prospective Cohort Study

Background: Mesh augmentation for large hiatal hernia is still controversial because of high alleged risk of chronic reaction or shrinkage of mesh orifice surrounding the esophagus. The aim of this cohort study was to develop and establish an image analysis scheme, including 3D reconstruction, for MRI-visible meshes (DynaMesh®) to measure postoperative mesh shrinkage in order to observe potential complications. Methods: Between 12/2012 and 10/2016, n = 33 patients underwent surgery to correct symptomatic hiatal hernia (implantation indicated: n = 18). Intraoperative measurement of the hiatal surface area (HSA) > 5 cm2 was indication for mesh implantation. Early postoperatively, and during long-term follow-up, MRI was performed and patients filled out the gastrointestinal quality of life index (GIQLI score). Results: Follow-up rate was 76% (n = 25/33). Overall recurrence rate was 4% (1/25). No other patient showed reflux or dysphagia symptoms. Mesh related complications were not observed during follow-up period. Median GIQLI score of patients with mesh was 123 (range: 67-144), and 93 (52-141) for patients without mesh. Comparison of early and mid-term postoperative MRI for patients with mesh showed changes in mesh orifice size of 3% (corresponding to a slight increase in size of about 6 mm2) without any significant correlations with BMI, HSA, or patient age. Conclusion: We established an image analysis and 3D reconstruction scheme for MRI visible meshes in hiatal hernia repair. MRI images of normal clinical quality are sufficient for this analysis. Mesh orifice size in MRI-visible meshes does not seem to change at a clinically relevant level in the small cohort observed here. Further studies of large cohorts are necessary to establish if HSA >5 cm2 could be a suitable measure for indication of mesh implantation.

Mesh implants for hernia repair: an update

INTRODUCTION

Today the use of textile meshes has become a standard for the treatment of abdominal wall hernias and for the reinforcement of any tissue repair as the strength of the implant decreases the recurrence rates. With increasing use, side effects of the textile implants became apparent, as well.

AREAS COVERED

Based on publications in Medline over the past decade, general and specific benefits, as well as risks, are discussed with the challenge to define individual risk-benefit ratios. For meshes, certain high-risk or low-risk conditions can be defined. In an attempt to eliminate mesh-related risks, quality control for medical devices has meanwhile been revised. In both the USA and the EU post-market surveillance studies are required to keep medical devices approved.

EXPERT COMMENTARY

The impact of material on the complication rate will vary depending on the patient's co-morbidity or the risks of the procedure. Even the best material can end up with disappointing results in case of poor healing or poor surgery. On the other hand, when using high-risk devices, most of the complications after excellent surgery with excellent indication can be supposed to be mesh-related. Thus, the use of low-risk devices is recommended even though its advantage may not be demonstrable in clinical studies.