Potential interest of a new absorbable collagen membrane in the prevention of adhesions in paediatric cardiac surgery: A feasibility study

Role of intermediate water in alleviating postsurgical intrapericardial adhesion

PURPOSE

Various polymers have been used as postsurgical antiadhesive materials; however, the mechanisms underlying their efficacy remain unclear. Intermediate water has been found to prevent the adhesion between polymer molecules and proteins or cells. The present study investigated the role of intermediate water retained in the polymer in alleviating postsurgical pericardial adhesion.

METHODS

Hydrophobic fabrics were prepared using biodegradable polyglycolic acid. To add intermediate water, the fabric fibers were coated with poly(oxyethylene)oleyl ethers. Intermediate water in the hydrated state was detected by a thermal analysis for each material, and cell attachment to the fibers with or without coating was observed in vitro. Using a canine model of postsurgical pericardial adhesion, the severity of adhesion was examined along with a histological assessment during treatment, with or without fabric coating.

RESULTS

Intermediate water was detected in the coating materials but not in polyglycolic acid. Coating significantly reduced the cell attachment to the fibers. Coating also alleviated adhesion by reducing inflammation in the fibrous layer and replacing the fabric and granulomas that develop around the surgical sutures in the pericardial space.

CONCLUSIONS

Intermediate water in the hydrated polymer of anti-adhesives may play an important role in alleviating postoperative pericardial adhesion.

Adhesion barriers in cardiac surgery: A systematic review of efficacy

BACKGROUND

Postoperative pericardial adhesions have been associated with increased morbidity, mortality, and surgical difficulty. Barriers exist to limit adhesion formation, yet little is known about their use in cardiac surgery. The study presented here provides the first major systematic review of adhesion barriers in cardiac surgery.

METHODS

Scopus and PubMed were assessed on November 20, 2020. Inclusion criteria were clinical studies on human subjects, and exclusion criteria were studies not published in English and case reports. Risk of bias was evaluated with the Cochrane Risk of Bias Tool. Barrier efficacy data was assessed with Excel and GraphPad Prism 5.

RESULTS

Twenty-five studies were identified with a total of 13 barriers and 2928 patients. Polytetrafluoroethylene (PTFE) was the most frequently evaluated barrier (13 studies, 67% of patients) with adhesion formation rate of 37.31% and standardized tenacity score of 26.50. Several barriers had improved efficacy. In particular, Cova CARD had a standardized tenacity score of 15.00.

CONCLUSIONS

Overall, the data varied considerably in terms of study design and reporting bias. The amount of data was also limited for the non-PTFE studies. PTFE has historically been effective in preventing adhesions. More recent barriers may be superior, yet the current data is nonconfirmatory. No ideal adhesion barrier currently exists, and future barriers must focus on the requirements unique to operating in and around the heart.

Prevention of Post-Operative Adhesions: A Comprehensive Review of Present and Emerging Strategies

Post-operative adhesions affect patients undergoing all types of surgeries. They are associated with serious complications, including higher risk of morbidity and mortality. Given increased hospitalization, longer operative times, and longer length of hospital stay, post-surgical adhesions also pose a great financial burden. Although our knowledge of some of the underlying mechanisms driving adhesion formation has significantly improved over the past two decades, literature has yet to fully explain the pathogenesis and etiology of post-surgical adhesions. As a result, finding an ideal preventative strategy and leveraging appropriate tissue engineering strategies has proven to be difficult. Different products have been developed and enjoyed various levels of success along the translational tissue engineering research spectrum, but their clinical translation has been limited. Herein, we comprehensively review the agents and products that have been developed to mitigate post-operative adhesion formation. We also assess emerging strategies that aid in facilitating precision and personalized medicine to improve outcomes for patients and our healthcare system.

Biomaterials to Prevent Post-Operative Adhesion

Surgery is performed to treat various diseases. During the process, the surgical site is healed through self-healing after surgery. Post-operative or tissue adhesion caused by unnecessary contact with the surgical site occurs during the normal healing process. In addition, it has been frequently found in patients who have undergone surgery, and severe adhesion can cause chronic pain and various complications. Therefore, anti-adhesion barriers have been developed using multiple biomaterials to prevent post-operative adhesion. Typically, anti-adhesion barriers are manufactured and sold in numerous forms, such as gels, solutions, and films, but there are no products that can completely prevent post-operative adhesion. These products are generally applied over the surgical site to physically block adhesion to other sites (organs). Many studies have recently been conducted to increase the anti-adhesion effects through various strategies. This article reviews recent research trends in anti-adhesion barriers.

Postoperative Pericardial Adhesion Prevention Using Collagen Membrane in Pigs: A Pilot Study

Objective:

The operating procedure of a resternotomy in open-heart surgery is a complicated procedure with potentially problematic outcomes partly due to potential adhesions in the pericardial cavity and retrosternal space. Use of a collagen membrane has shown encouraging results in adhesion prevention in several regions of the body. This study was designed to evaluate the effectiveness of the use of this collagen membrane in the prevention of pericardial adhesions.

Materials and methods:

A total of 12 pigs were divided randomly into 2 groups: an experimental group in which collagen membranes were used and a control group. After sternotomy and an anterior pericardiectomy, the epicardial surface was exposed to room air and irrigated with saline, and an epicardial abrasion was performed using a sponge. The pericardial defect was repaired using a collagen membrane in the experimental group or left uncovered in the control group. After 8 to 12 weeks, the pigs were killed, and a resternotomy was performed by a single-blinded surgeon enabling the evaluation of adhesions. The heart was then removed and sent for microscopic assessment conducted by a single-blinded pathologist.

Results:

The resternotomy operations performed using a collagen membrane demonstrated a nonstatistically significant trend of fewer macroscopic and microscopic adhesions in all regions (P > .05), particularly in the retrosternal and defect regions.

Conclusions:

This study showed nonstatistically significant differences between the outcomes in the collagen membrane group and the control group in both macroscopic and microscopic adhesion prevention. Due to the many limitations in animal study design, further studies in human models will be needed before the true value of this procedure can be evaluated.

Variation on a Theme: Alternative to Plastic Bag in ALPPS Procedures: Feasibility and Clinical Safety of COVA+™ Membrane in ALPPS Procedures

BACKGROUND

Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) got wide success among hepatic surgeons as an efficient way to shorten to 7 days from the 4 weeks interval of classic 2-staged hepatectomy. The main disadvantage of ALPPS is the onset of inflammatory adhesions, particularly on the hepatic pedicle region, previously dissected. The aim of the study is the evaluation of a resorbable collagen membrane (CM) indicated in the prevention of postoperative adhesions as an alternative to the use of a plastic bag (PB) during ALPPS procedure.

METHODS

All patients undergoing ALPPS procedure in our department were prospectively included in a database. At the end of the first surgery, at least one resorbable CM (COVA+™, Biom'Up, France) was placed instead of a PB. Intraoperative adhesions during the second step and clinical short-term safety were assessed.

RESULTS

Ten patients with a mean age of 57.5 years underwent a 2-staged hepatectomy through ALPPS approach. At the second stage, 90 % of the patients experienced either grade-0 (no adhesion) or grade-I adhesions (mild adhesions easily divided). None of the reported complications were related to the use of the CM.

CONCLUSION

To our knowledge, this is the first clinical study evaluating the use of an anti-adhesion resorbable CM as a safe and efficient alternative to PB in ALPPS procedures.

Is Seprafilm valuable in infant cardiac redo procedures?

BACKGROUND

Morbidity and mortality are higher for cardiac reoperations than first operation due to the presence of post-operative adhesions. We retrospectively evaluated the efficacy of the bioresorbable membrane Seprafilm to prevent pericardial adhesions after cardiac surgery in a paediatric congenital heart disease population.

METHODS

Seventy-one children undergoing reoperations with sternotomy redo and cardiopulmonary bypass for congenital malformations were included. Twenty-nine of these patients were reoperated after previous application of Seprafilm (treatment group). The duration of dissection, aortic cross clamping and total surgery were recorded. A tenacity score was established for each intervention from the surgeon's description in the operating report.

RESULTS

In multivariate analysis, the duration of dissection and the tenacity score were lower in the treatment than control group (p < 0.01), independent of age and interval since preceding surgery.

CONCLUSION

Our results suggest that Seprafilm is effective in reducing the post-operative adhesions associated with infant cardiac surgery. We recommend the use of Seprafilm in paediatric cardiac surgery when staged surgical interventions are necessary.