Injectable Double Crosslinked Hydrogel-Polypropylene Composite Mesh for Repairing Full-Thickness Abdominal Wall Defects

Abdominal wall defects are common clinical diseases, and mesh repair is the standard treatment method. The most commonly used polypropylene (PP) mesh in clinical practice has the advantages of good mechanical properties, stable performance, and effective tissue integration effect. However, direct contact between abdominal viscera and PP mesh can lead to severe abdominal adhesions. To prevent this, the development of a hydrogel-PP composite mesh with anti-adhesive properties may be an effective measure. Herein, biofunctional hydrogel loaded with rosmarinic acid is developed by modifying chitosan and Pluronic F127, which possesses suitable physical and chemical properties and commendable in vitro biocompatibility. In the repair of full-thickness abdominal wall defects in rats, hydrogels are injected onto the surface of PP mesh and applied to intraperitoneal repair. The results indicate that the use of hydrogel-PP composite mesh can alleviate abdominal adhesions resulting from traditional PP mesh implantation by decreasing local inflammatory response, reducing oxidative stress, and regulating the fibrinolytic system. Combined with the tissue integration ability of PP mesh, hydrogel-PP composite mesh has great potential for repairing full-thickness abdominal wall defects.

[Safety of mesh with fluoropolymer coating during intra-abdominal placement in large animals: results of the pilot study]

OBJECTIVE

When performing laparoscopic intraperitoneal hernioplasty (IPOM), endoprostheses made of fluoropolymers are often used. However, there is no data in the literature on the intra-abdominal use of inexpensive polyester prostheses with a fluoropolymer coating compared to composite implants. Thus, the aim of the pilot study was a preliminary assessment of the safety profile of FTOREX mesh endoprostheses during intra-abdominal placement in large animals.

MATERIAL AND METHODS

6 endoprostheses were installed laparoscopically intraperitoneally in each of the 3 pigs: 1) FTOREX; 2) FTOREX with a layer of carboxymethylcellulose; 3) REPEREN-16-2; 4) SYMBOTEX; 5) VENTRALIGHT ST; 6) decellularized pork peritoneum. Fixation was performed with a herniator, transfascial sutures were not used. Relaparoscopy was performed after 45 days, and withdrawal from the experiment was performed after 90 days. Performance characteristics, signs of deformation and retraction, parameters of spike formation were evaluated.

RESULTS

All the animals survived, no complications were observed. There were no clinical manifestations or behavioral reactions indicating the presence of adhesions. The most convenient to use were the SYMBOTEX and FTOREX implants (5.0 points each). By the end of the experiment, deformation and retraction were noted in both variants of the FTOREX implants and the REPEREN prosthesis. These changes were completely absent only when using the SYMBOTEX endoprosthesis. According to the number of implants with adhesions, by the end of the observation, both variants of FTOREX prostheses occupied an intermediate position between the Reference (the worst indicator) and VENTRALIGHT ST (the best indicator). However, both FTOREX endoprostheses showed the best performance among all implants in the integral assessment of adhesions, as well as in terms of parameters such as the area and appearance of adhesions, and in terms of the strength of the joints, they were second only to the VENTRALIGHT ST endoprosthesis (0.67 vs. 0.5 points). During the study, there was no reliable dependence of deformation, retraction and adhesion formation indicators on the type of implant.

CONCLUSION

The results of the pilot study showed that all the implants used did not cause any clinically significant adverse reactions or complications. FTOREX endoprostheses with their intraperitoneal installation have anti-adhesive properties that are not inferior to VENTRALIGHT ST or SYMBOTEX composite implants. However, having less rigidity, they are more often deformed and subjected to retraction.

PuraStat RADA16 Self-Assembling Peptide Reduces Postoperative Abdominal Adhesion Formation in a Rabbit Cecal Sidewall Injury Model

Objective: To evaluate the effect of PuraStat (2.5% RADA16) administration on postoperative abdominal adhesion formation in an in vivo model.

Methods: Anesthetized New Zealand white rabbits underwent cecal sidewall abrasion surgery in which the cecal serosa and juxtaposed parietal peritoneum were abraded after access through an abdominal midline incision. Eight animals were randomized to receive PuraStat administration at the interface of the injured tissues before incision closure, and five animals served as untreated controls. Treated animals received 3–12 ml PuraStat solution per lesion. Animals were sacrificed 14 days after surgery and examined for adhesion formation at the wound site.

Results: At study terminus, adhesions were identified in 90% (9/10) of abraded cecum/peritoneal wound sites in untreated controls versus 25% (4/16) of PuraStat-treated sites (p = 0.004). Mean ± SD Total Adhesion Score (average of the values for extent + strength of the adhesion in both defects per animal; maximum score = 14 points) was significantly 76% lower in PuraStat-treated animals (2.0 ± 3.0 points) compared to untreated controls (8.2 ± 1.9 points) (p = 0.029). Mean adhesion coverage area of wound sites was 79% lower in PuraStat-treated animals than controls (p < 0.001), and mean adhesion durability was 72% lower in PuraStat-treated animals versus controls (p = 0.005). Remnant hydrogel was observed at the wound sites of 75% of treated animals at postoperative Day 14.

Conclusion: PuraStat treatment has a positive protective effect in the cecal sidewall injury model, and significantly reduces abdominal adhesion formation at the interface of the injured cecum and overlying peritoneal sidewall defect.

[Existing and forward-looking ways to prevent adhesions in IPOM hernia repair. A research overview]

IPOM intraperitoneal hernia repair, in comparison with other abdominal wall reconstruction methods, has a number of significant advantages. Among them are a reduction in operative time, low rate of surgical site infections, quick rehabilitation, and good cosmetic results. At the same time, one of the main constraining factors for its widespread use is the rather high frequency of adhesion formation between the implant and the abdominal organs. The first way to solve this serious problem is to improve the structure of the implant itself, and in the first place, its anti-adhesive layer. The second is the search for adjuvant tools that work in «problematic» areas, prone to adhesions formation, such as the points of implant fixation, its edges, or the areas of damage to antiadhesive layer due to a violation of the operative technique. It is desirable that they could exert their effect also in other parts of the abdominal cavity, which, despite the absence of a zone of «active» intervention, can also undergo adhesions. Based on this, the purpose of this review was to summarize modern data on the anti-adhesive activity of both composite implants and specialized membranes and liquid agents.

[Laparoscopic adhesiolysis and prevention of abdominal adhesions by using mechanical barriers]

Adhesions commonly result from abdominal and pelvic surgical procedures and may result in intestinal obstruction, infertility, chronic pain, or complicate subsequent operations. Laparoscopy produces less peritoneal trauma than does conventional laparotomy and may result in decreased adhesion formation. We present a review of the available data on laparoscopy and adhesion formation, as well as laparoscopic adhesiolysis. We also review current adjuvant techniques that may be used by practicing laparoscopists to prevent adhesion formation.