Short-Term Postoperative Outcomes between 4% Icodextrin Solution and Hyaluronic Acid- Carboxymethyl Cellulose Membrane during Emergency Cesarean Section

Adhesive Nanoparticle-in-Microgel System with ROS Scavenging Capability and Hemostatic Activity for Postoperative Adhesion Prevention

Postoperative adhesion is a noteworthy clinical complication in abdominal surgery due to the existing physical barriers are unsatisfactory and inefficient in preventing its occurrence. In this work, an elaborate nanoparticle-in-microgel system (nMGel) is presented for postoperative adhesion prevention. nMGel is facilely formed by crosslinking manganese dioxide (MnO2) nanoparticles-loaded gelatin microspheres with polydopamine using a modified emulsification-chemical crosslinking method, generating a nano-micron spherical hydrogel. After drying, powdery nMGel with sprayability can perfectly cover irregular wounds and maintains robust tissue adhesiveness even in a wet environment. Additionally, nMGel possesses prominent antioxidant and free radical scavenging activity, which protects cell viability and preserves cell biological functions in an oxidative microenvironment. Furthermore, nMGel displays superior hemostatic property as demonstrated in mouse tail amputation models and liver trauma models. Importantly, nMGel can be conveniently administrated in a mouse cecal defect model to prevent adhesion between the injured cecum and the peritoneum by reducing inflammation, oxidative stress, collagen synthesis, and angiogenesis. Thus, the bioactive nMGel offers a practical and efficient approach for ameliorating postsurgical adhesion.

Biosafe Polydopamine-Decorated MnO2 Nanoparticles with Hemostasis and Antioxidative Properties for Postoperative Adhesion Prevention

Surgical bleeding and cumulative oxidative stress are significant factors in the development of postoperative adhesions, which are always associated with adverse patient outcomes. However, effective strategies for adhesion prevention are currently lacking in clinical practice. In this study, we propose a solution using polydopamine-decorated manganese dioxide nanoparticles (MnO2@PDA) with rapid hemostasis and remarkable antioxidant properties to prevent postsurgical adhesion. The PDA modification provides MnO2@PDA with enhanced tissue adhesiveness and hemocompatibility with negligible hemolysis. Furthermore, MnO2@PDA exhibits impressive antioxidant and free radical scavenging properties, protecting cells from the negative effects of oxidative stress. The hemostatic activity of MnO2@PDA is evaluated in a mouse truncated tail model and a liver injury model, with results demonstrating reduced bleeding time and volume. The in vivo test on a mouse cecal abrasion model shows that MnO2@PDA exhibits excellent antiadhesion properties coupled with alleviated inflammation around the damaged tissue. Therefore, MnO2@PDA, which exhibits high biosafety, rapid hemostasis, and beneficial antioxidant capacity, displays exceptional antiadhesion performance, holding great potential for clinical applications to prevent postoperative adhesion.

Limited efficacy with additional adverse effect of anti-adhesion barrier at primary cesarean section

BACKGROUND/PURPOSE

In our experience, adhesion after the primary CS is generally minimal or nonexistent. However, adhesion barriers users have experienced more febrile episodes that may require therapeutic antibiotics during the postcesarean period. We evaluated clinical efficacy of HA-CMC and ORC to prevent adhesion at secondary CS and the post-operative outcome at primary and secondary CS.

METHODS

This retrospective study includes 199 Asian women undergoing primary and secondary cesarean section between January1, 2011, and September 31, 2019. We used linear and logistic regression to analyze risk factors of postcesarean fever. An interaction term analysis was performed to examine the effect of surgical site infection risk factors and use of adhesion barrier on postcesarean fever rates.

RESULTS

We found that use of adhesion barrier at the primary cesarean section is associated with a significantly higher incidence of postcesarean fever (p = 0.045), which is an independent risk factor of postcesarean fever (adjusted hazard ratio (Adj-HR)= 3.53, 95% CI = 1.03-10.24, p = 0.045). The strongest risk factor for postcesarean fever is the use of anti-adhesion film during emergency cesarean section (p = 0.041). In the subgroup of labor before operation and emergency cesarean section, adhesion barrier user had significant higher risk of postcesarean fever than nonuser (p = 0.018, Adj-HR = 12.12, 95% CI = 1.53-95.78; emergency cesarean section: p = 0.016, Adj-HR = 12.71, 95% CI = 1.62-99.62).

CONCLUSION

Use of anti-adhesion films during emergency cases and with a significantly higher risk of postcesarean fever which potentially means increased risk of surgical site infection. Therefore, we do not suggest routine application of anti-adhesion films during cesarean deliveries especially in emergency cesarean section or in a woman having labor before operation.

Peritoneal adhesions: Occurrence, prevention and experimental models

Peritoneal adhesions (PA) are a postoperative syndrome with high incidence rate, which can cause chronic abdominal pain, intestinal obstruction, and female infertility. Previous studies have identified that PA are caused by a disordered feedback of blood coagulation, inflammation, and fibrinolysis. Monocytes, macrophages, fibroblasts, and mesothelial cells are involved in this process, and secreted signaling molecules, such as tumor necrosis factor alpha (TNF-α), interleukin-10 (IL-10), tissue plasminogen activator (tPA), and type 1 plasminogen activator inhibitor (PAI-1), play a key role in PA development. There have been many attempts to prevent PA formation by anti-PA drugs, barriers, and other therapeutic methods, but their effectiveness has not been widely accepted. Treatment by biomaterial-based barriers is believed to be the most promising method to prevent PA formation in recent years. In this review, the pathogenesis, treatment approaches, and animal models of PA are summarized and discussed to understand the challenges faced in the biomaterial-based anti-PA treatments.