Biomechanical Features of Reinforced Esophageal Hiatus Repair in a Porcine Model

Outcomes of Bariatric Surgery With Concomitant Hiatal Hernia Repair Using an Absorbable Tissue Matrix

BACKGROUND

Hiatal hernias are a common finding in patients who undergo bariatric surgery with an incidence of about 20% of all bariatric patients. Controversy exists on the utility of a biosynthetic tissue matrix (BTM) usage in combination with crural repair. This study was designed to explore the safety and benefits of the use of a BTM during concomitant hiatal hernia repair with bariatric surgical procedures.

METHODS

This was a retrospective chart review of bariatric surgical patients who underwent a concomitant hiatal hernia repair at a single practice at a tertiary academic medical center from January 2014 to February 2019.

RESULTS

A total of 420 patients were reviewed. Hiatal BTM reinforcement, recurrence, and postoperative proton pump inhibitor use were reported by type of operation. Recurrence was higher in gastric bypass patients who underwent hiatal hernia repair with suture cruroplasty alone vs. those who also underwent hiatal BTM reinforcement (7.1% vs. 3.7%, P = .52) and significantly higher in gastric sleeve patients who underwent hiatal hernia repair with suture cruroplasty alone vs. those who also underwent hiatal BTM reinforcement (7.1% vs. .5%, P = .01). No patient required reoperation for hiatal hernia recurrence.

DISCUSSION

Performing Roux-en-Y gastric bypass or vertical sleeve gastrectomy with concomitant hiatal hernia repair is safe and durable. Employing crural reinforcement with BTM may be of benefit in reducing recurrence rates of hiatal hernia, particularly in sleeve gastrectomy patients.

A Systematic Review Examining the Experimental Methodology Behind In Vivo Testing of Hiatus Hernia and Diaphragmatic Hernia Mesh

INTRODUCTION

Mesh implants are regularly used to help repair both hiatus hernias (HH) and diaphragmatic hernias (DH). In vivo studies are used to test not only mesh safety, but increasingly comparative efficacy. Our work examines the field of in vivo mesh testing for HH and DH models to establish current practices and standards.

METHOD

This systematic review was registered with PROSPERO. Medline and Embase databases were searched for relevant in vivo studies. Forty-four articles were identified and underwent abstract review, where 22 were excluded. Four further studies were excluded after full-text review-leaving 18 to undergo data extraction.

RESULTS

Of 18 studies identified, 9 used an in vivo HH model and 9 a DH model. Five studies undertook mechanical testing on tissue samples-all uniaxial in nature. Testing strip widths ranged from 1-20 mm (median 3 mm). Testing speeds varied from 1.5-60 mm/minute. Upon histology, the most commonly assessed structural and cellular factors were neovascularisation and macrophages respectively (n = 9 each). Structural analysis was mostly qualitative, where cellular analysis was equally likely to be quantitative. Eleven studies assessed adhesion formation, of which 8 used one of four scoring systems. Eight studies measured mesh shrinkage.

DISCUSSION

In vivo studies assessing mesh for HH and DH repair are uncommon. Within this relatively young field, we encourage surgical and materials testing institutions to discuss its standardisation.

Platelet-rich plasma PRP vs. absorbable mesh as cruroplasty reinforcement: a study on an animal model

BACKGROUND

Reinforcement of posterior cruroplasty has been proposed to minimize the failure of hiatal hernia repair (HHR). The applications of autologous platelet-rich plasma (PRP) and absorbable mesh are barely reported in this area.

AIMS

To analyze local macroscopic and microscopic changes induced by mesh vs. PRP as reinforcement of HHR, using a reliable laparoscopic experimental porcine model.

MATERIAL AND METHODS

This prospective, comparative pilot study was conducted on 14 female pigs, aged four to six months. An iatrogenic hiatal defect was laparoscopically simulated and repaired, reinforced with Bio-A® mesh (group A) or PRP (group B). Specimen retrieval was performed after seven months for histopathological (HP) examination.

RESULTS

No local or general complications were registered, with complete resorption of reinforcements, that determined inflammatory infiltrates with local collagen production and tissue neo-vascularization. Group A had an increased mean chronic inflammation score (p = .3061), showing significant sclerotic collagenizing process. PRP enhanced angiogenesis, collagenizing, myofibroblast recruitment and tissue ingrowth.

CONCLUSIONS

No residual materials or evidence of anatomical distortion were found. Animal model was safe and reliable. This is the first report of complete absorption of Bio-A^® positioned on crural area. HP results suggest the clinical application of PRP in HHR as a promising co-adjuvant to local remodeling and healing.Abbreviations: ASA: American Society of Anesthesiologists; AB: Alcian Blue; PAS: Periodic Acid-Schiff; CP: platelet concentrate; fPC: filtered plasma concentrate; GERD: gastro-esophageal reflux disease; HSA: hiatal surface area; HHR: hiatal hernia repair; HP: histopathological; HH: hiatal hernia; HE: hematoxylin and eosin; HR: hiatus repair alone; HRM: hiatus repair and acellular dermal matrix; NM: Nicolae Manolesccu; LNF: laparoscopic Nissen fundoplication; PC: posterior cruroplasty; PPP: platelet-poor plasma; RP: platelet-rich plasma.

Urinary Bladder Matrix Scaffolds Promote Pericardium Repair in a Porcine Model

Pericardium closure after cardiac surgery is recommended to prevent postoperative adhesions to the sternum. Synthetic materials have been used as substitutes, with limited results because of impaired remodeling and fibrotic tissue formation. Urinary bladder matrix (UBM) scaffolds promote constructive remodeling that more closely resemble the native tissue. The aim of the study is to evaluate the host response to UBM scaffolds in a porcine model of partial pericardial resection. Twelve Landrace pigs were subjected to a median sternotomy. A 5 × 7 cm pericardial defect was created and then closed with a 5 × 7 cm multilayer UBM patch (UBM group) or left as an open defect (control group). Animals were survived for 8 wk. End points included gross morphology, biomechanical testing, histology with semiquantitative score, and cardiac function. The UBM group showed mild adhesions, whereas the control group showed fibrosis at the repair site, with robust adhesions and injury to the coronary bed. Load at failure (gr) and stiffness (gr/mm) were lower in the UBM group compared with the native pericardium (199.9 ± 59.2 versus 405.3 ± 99.89 g, P = 0.0536 and 44.23 ± 15.01 versus 146.5 ± 24.38 g/mm, P = 0.0025, respectively). In the UBM group, the histology resembled native pericardial tissue, with neovascularization, neofibroblasts, and little inflammatory signs. In contrast, control group showed fibrotic tissue with mononuclear infiltrates and a lack of organized collagen fibers validated with a histologic score. Both groups had normal ultrasonography results without cardiac motility disorders. In this setting, UBM scaffolds showed appropriate features for pericardial repair, restoring tissue properties that could help reduce postsurgical adhesions and prevent its associated complications.