Post-Operative Adhesions: A Comprehensive Review of Mechanisms

Bioinspired Janus Mesh with Mechanical Support and Side-specific Biofunctions for Hernia Repair

Postoperative adhesion (PA) caused by the combination of proteins, inflammatory response and bacterial infection poses substantial challenges for polypropylene meshes (PPMs) based hernioplasty. Herein, inspired by the peritoneum, a Janus PPMs with side-specific functions was developed via a surface-initiated photoiniferter-mediated polymerization technology. A physical barrier composed of zwitterionic polymer brushes (PS) was firstly constructed on the one side of the PPMs, while the polymethacrylic acid (PMAA) brushes acting as the linker for bioactive nanoparticles (HAP) were precisely situated on the opposite surface subsequently. Our findings reveal that the mesh surface modified with PS demonstrated significant antifouling property that more than 99% of protein adhesion could be inhibited even after the co-incubation for 72 h in the crucial test. Meanwhile, on the other surface of the PPMs modified with HAP achieved satisfactory ROS-scavenging, inflammation-inhibiting and cell adhesion-promoting properties as well as good bactericidal performance (killing rate > 99.9%). Furthermore, the Janus PPMs could maintain comparable mechanical property with pristine meshes. Equipped with the above multiple merits and asymmetric property, the constructed Janus PPMs demonstrated effective treatment for abdominal hernia defects in vivo without any PA formation. Overall, this study duplicates the unique characteristics of peritoneum onto PPMs to successfully address postoperative complications of the hernioplasty and also offers a versatile and innovative idea to construct asymmetrical functions on the one implant. STATEMENT OF SIGNIFICANCE: The implantation of surgical meshes in the hernia defect provides additional firm support to reinforce the abdomen fascia in tension-free way. However, multiple post-surgery complications induced tissue adhesions is of great challenges for commercial mesh-based hernioplasty. Although material designing and surface modification might circumvent these limitations partly, the construction of side-specific biofunctions on the commercial mesh surfaces is very challenging because of its porous structure. Herein, we demonstrate a feasible and promising approach to construct asymmetric biofunctions on the opposite sides of network structured polypropylene mesh, which is rarely achieved previously. The fabricated Janus PPMs maintains the inherent long-term mechanical support; meanwhile, the opposite sides of PPMs could perform multiple biofunctions independently.

Mesothelial cell responses to acute appendicitis or small bowel obstruction reactive ascites: Insights into immunoregulation of abdominal adhesion

Previous abdominal surgery (PAS) increases risk of small bowel obstruction (SBO) due to adhesions, and appendectomy (appy) is an independent risk factor for abdominal adhesion-related complications. Peritoneal inflammation, e.g., acute appendicitis (AA), causes formation of reactive ascitic fluid (rA) that activates peritoneum surface mesothelial cells (MCs) to form adhesions. Pathologic adhesions may arise if restoration of MC-regulated fibrinolysis and secretion of glycocalyx (GCX) are disrupted. Proteins affecting these processes may originate from peritoneal rA. This is a prospective observational IRB-approved study at three Level 1 trauma centers where rA is collected prior to surgical intervention for non-perforated AA or adhesiolysis for SBO. Samples from 48 appy and 15 SBO patients were used to treat human MCs and subjected to quantification of 85 inflammatory mediators. Results were compared between patients with surgically naïve abdomens (naïve) and patients with >1 PAS. Select rA caused MCs to form clusters of fibroblastic cells, extracellular matrix fibers (FIB), and secretion of GCX. PAS and naïve patient rA fluids were clustered into "fiber-GCX" (FIB-GCX) groups: highFIB-highGCX, highFIB-lowGCX, noFIB-highGCX, noFIB-lowGCX, and noFIB-noGCX. Between groups, 26 analytes were differentially abundant including innate immune response, wound healing, and mucosal defense proteins. Factors that contributed to the differences between groups were rA-induced highFIB and history of PAS. Overall, PAS patient rA showed a muted immune response compared to rA from naïve patients. Our data suggest that abdominal surgery may negatively impact future immune responses in the abdomen. Further, quantifying immunomodulators in peritoneal rA may lead to the development a personalized approach to post-surgical adhesion treatment and prevention.

Assessment of peri- and post-operative outcomes following apical prolapse repair in octogenarians: A retrospective cohort study

OBJECTIVE

To assess the risk of postoperative complications and unanticipated healthcare encounters in octogenarians compared to younger patients following apical prolapse repair.

DESIGN

Retrospective cohort study.

SETTINGS

University-affiliated academic tertiary hospital center.

INTERVENTION

Surgery for pelvic organ prolapse PATIENTS: Patients who underwent apical prolapse repair between 2009 and 2024. The cohort was divided into two groups: 1) Patients over the age of 80 (octogenarians); 2) Patients aged 18-79 (younger cohort). Patients who underwent obliterative procedures or had missing complication data within 30 days post-surgery were excluded.

MEASUREMENTS AND MAIN RESULTS

A total of 481 patients were analyzed, including 136 octogenarians and 355 younger patients. Postoperative complications within 30 days were the primary outcome, while secondary outcomes included unanticipated healthcare encounters such as emergency department visits, clinic visits, and readmissions. Octogenarians had significantly higher frequency of comorbidities, such as hypertension (61.5% vs. 28.1%, p < 0.001) and a history of deep vein thrombosis (6.7% vs. 1.7%, p < 0.001), compared to younger patients. However, overall complication frequency within 30 days did not differ significantly between groups (7.4% vs. 7.6%, p = 0.934). Specific complications varied, with octogenarians experiencing higher frequency of postoperative urinary retention (5.2% vs. 0%, p < 0.001), and younger patients showing a higher likelihood of urinary tract infections (5.9% vs. 0.7%, p = 0.013). Multivariate analysis identified prior abdominal surgery (OR: 2.20, 95% CI: 1.05-4.57, p = 0.036) and undergoing anterior repair (OR: 3.36, 95% CI: 1.27-8.89, p = 0.015) as predictors of complications within 30 days. No significant differences were observed in unanticipated healthcare encounters between groups.

CONCLUSION

Apical prolapse repair in octogenarians is safe and feasible, with similar complication frequencies and healthcare encounters compared to younger patients. These findings suggest that age alone should not preclude surgical intervention in this population, though individualized risk assessment remains crucial.

An Interior/Exterior Collaboration-Enhanced Intestinal Anastomosis (IECIA) for Multi-Tiered Leakage Complication Management

Anastomotic leakage (AL) is a pervasive and risky postoperative complication that presently features inaccessible prevention, delayed diagnosis, and intractable remediation, resulting in distressing morbidity and mortality. Herein an interior/exterior collaboration-enhanced neoteric intestinal anastomosis (IECIA) is developed, which consists of an interior hydrogel-based protective barrier adhering to mucosa, and exterior synergistic leakage-prevention safeguard sutured to serosa, for multi-tiered leakage complication management. Noticeably, the hydrogel barrier protects anastomosis stoma against injurious stimulation from digestive liquid, consequently reducing leakage risk effectively and comfortably in place of painful gastric tube insertion. The exterior safeguard encompassing fluorescein-loaded hydrogel and electrospun film functions as a secondary defense, exhibiting critical leakage-prevention capability to refrain from lethal intra-abdominal infection. Meanwhile, fluorescein is released to the enteric cavity for following detection within the excrement in case anastomotic leakage occurs, achieving presymptomatic alarming in providing valuable prompts for timely clinical intervention. Importantly, IECIA has been investigated in realistic in vivo end-to-end intestinal anastomosis scenarios as well as simulated leakage models, which present satisfactory postoperative recovery of gastrointestinal functions and systematic indexes. Moreover, the IECIA system is endowed with guaranteed biocompatibility, effective durability, comprehensibility for surgical operation, comfort, and compliance for patients, which demonstrates precious value for clinical translation.

Challenges following CRS and HIPEC surgery in cancer patients with peritoneal metastasis: a comprehensive review of clinical outcomes

Cytoreductive Surgery (CRS) and Hyperthermic Intraperitoneal Chemotherapy (HIPEC) are a pair of relatively modern therapeutic surgical methods in advanced cancerous patients with peritoneal metastasis (PM). The goal of CRS + HIPEC is treatment or to improve survival outcomes, which are linked to high morbidity side effects and complications, even with their possible advantages. Surgical-related, chemotherapy-related, anesthetic-related, gastrointestinal, organs and systemic complications are the categories into which complications are separated according to frequency, risk factors, and effect on patient outcomes. In this narrative review of the literature, the side effects and complications of HIPEC + CRS in cancer patients with PM are examined. The present knowledge on the incidence, frequency, kinds, and risk factors of acute complications following CRS + HIPEC is summarized in this study. This review emphasizes the need for careful patient selection criteria, precise surgical technique, and thorough intraoperative care to reduce or manage these risks. Moreover, it highlights the need for interdisciplinary collaboration in treating these patients. This study aims to know these complications, improve clinical practice, and guide future studies to increase the safety and efficacy of CRS + HIPEC in treating metastatic colorectal cancer.

Complications of Post-Roux-en-Y Gastric Bypass: A Case of Excluded Stomach Perforation

Roux-en-Y gastric bypass (RYGB) is a common surgical treatment for morbid obesity, but rare complications involving the excluded gastric remnant can pose significant challenges. A 65-year-old female with a history of RYGB presented with sudden onset of left upper quadrant abdominal pain, bloating, nausea, and loss of appetite. Laboratory tests revealed leukocytosis. An initial CT scan showed significant distention of the excluded stomach, suggesting possible obstruction. While preparing for percutaneous decompression, her abdominal pain worsened acutely. A repeat CT scan demonstrated decompression of the excluded stomach and new free fluid in the abdomen, indicating a perforation. Emergent exploratory laparotomy uncovered a large necrotic perforation in the excluded gastric remnant and extensive adhesions from prior surgeries. A partial gastrectomy and antrectomy were performed to remove the perforated tissue. Pathological examination revealed ulcerated gastric mucosa with acute and chronic inflammation, reactive gastropathy, and no evidence of Helicobacter pylori infection or malignancy. Postoperatively, the patient recovered well with supportive care and was discharged home. Diagnosing complications in the excluded stomach after RYGB is challenging due to altered anatomy and nonspecific symptoms. Maintaining a high index of suspicion is essential when evaluating post-RYGB patients with unexplained abdominal pain. Early recognition and prompt surgical intervention are critical for favorable outcomes in these patients.

Lycopene Inhibits Postoperative Abdominal Adhesion Formation in a Mouse Model

INTRODUCTION

The prevention of postoperative abdominal adhesions is one of the top concerns of surgeons after abdominal surgery. Therefore, identifying effective interventions to reduce postoperative abdominal adhesions are essential.

METHODS

Fifty male Bagg's albino/c mice were randomly divided into five groups, and all groups underwent postoperative adhesion model surgery, except for the sham group. The sham and control groups were gavaged with saline solution. Based on the control group, the sodium hyaluronate group was treated with 1 mL sodium hyaluronate (smeared on the modeling site and the abdominal cavity was closed). The other two groups were gavaged with different doses of lycopene (10 μg/kg and 20 μg/kg). Seven d after surgery, the mice were sacrificed and adhesion conditions were assessed using Nair's scoring system. Subsequently, adherent tissues were harvested and the inflammation was assessed by using haematoxylin and eosin staining and enzyme linked immunosorbent assay for interleukin-6 and transforming growth factor-β1. Oxidative stress and collagen deposition condition were also detected in each mouse. Furthermore, a lycopene-induced HMrSV5 cell model was used to explore the possible functional mechanisms.

RESULTS

20 μg/kg of lycopene-treated group had a lower Nair's and inflammation score, both with an average score of 1.75. Also, the level of transforming growth factor -β1 and interleukin-6 in the 20 μg/kg of lycopene-treated group was lower than others. Furthermore, 20 μg/kg of lycopene had reduced the reactive oxygen species and malondialdehyde levels in adhesion tissues compared to other groups. Fiber thickness and α-smooth muscle actin expression in adherent tissues were significantly reduced after lycopene treatment. Besides, 20 μg/kg of lycopene treatment can promote the expression of nuclear factor erythroid 2-related factor 2 and silent information regulator 1. In in-vitro studies, lycopene protected mesothelial cells from H2O2 -induced oxidative stress injury.

CONCLUSIONS

Lycopene can attenuate abdominal adhesion in the mouse model by reducing inflammation and oxidative stress, and the possible mechanism may rely on promoting the expression of nuclear factor erythroid 2-related factor 2 and silent information regulator 1.

Biodegradable exosome-engineered hydrogels for the prevention of peritoneal adhesions via anti-oxidation and anti-inflammation

Peritoneal adhesions (PA) are a common and severe complication after abdominal surgery, impacting millions of patients worldwide. The use of anti-adhesion materials as physical barriers is an effective strategy to prevent postoperative adhesions. However, the local inflammatory microenvironment exerts a significant impact on the efficacy of anti-adhesion therapies. In this study, an injectable hydrogel based on oxidized dextran/carboxymethyl chitosan (DCC) is designed and prepared. Furthermore, the DCC hydrogel is specifically engineered to load the adipose mesenchymal stem cells (ADSCs)-derived exosomes (Exos) for the treatment of PA. The prepared DCC hydrogel can act as the physical barrier via covering the irregular wound surface effectively. Moreover, it shows controlled degradation property, enabling the regulated release of Exos. The DCC hydrogel loaded Exos (DCC/Exo) system has high antioxidant capacity, and can effectively modulate the inflammatory microenvironments and diminish apoptosis. Notably, it promotes a polarization shift towards the M2-like phenotype in macrophages. The RNA-seq analysis confirms that the DCC/Exo system exhibits significant anti-inflammatory properties and promotes a reduction in collagen deposition. Consequently, the DCC/Exo system can inhibit peritoneal adhesions significantly in a mouse cecum-abdominal wall injury model. These results demonstrate the DCC/Exo is an ideal material for preventing postoperative adhesions.

A simplified pre-conceptional laparoscopic cervical cerclage for cervical insufficiency: a retrospective study from a single center

BACKGROUND

Cervical insufficiency is a pathological condition in obstetrics in which the cervix fails to retain the fetus before uterine contractions or labor (painless cervical dilatation). Patients usually have fetal loss in the mid-trimester or spontaneous pre-term birth due to painless cervical dilation. For non-pregnant women with cervical insufficiency, prophylactic laparoscopic abdominal cerclage (LAC) has been reported to improve pregnancy outcomes, such as live birth, neonatal survival, and full-term delivery rate. Conventional LAC involves opening the vesicular space and separating the anterior broad ligament leaves. In our surgical procedure, these two steps were omitted.

METHODS

An observational study was conducted retrospectively on patients who underwent a simplified pre-conceptional LAC between January 2015 and December 2022 at West China Second University Hospital, Sichuan University. Follow-ups for all the patients ended at the delivery of the fetus. Subsequently, clinical characteristics, perioperative data, and obstetric outcomes were recorded and analyzed.

RESULTS

In total, 108 patients were included in a pre-conception LAC group Mean operation time was 56.8 ± 22.8 min, and mean estimated blood loss was 21.4 ± 23.6 mL. Only one case of urinary retention was classified as a grade I postoperative complication, according to the Clavien-Dindo classification. No severe complications or sequelae were observed during the perioperative period. Obstetric outcomes from 98 patients were collected: three patients had miscarriages, and 95 had live births. Of the 95 live births, 4 were twins and 91 were singletons. Two patients had vaginal delivery, and 93 underwent Cesarean section; mean neonatal weight was 3310.2 ± 382.1 g.

CONCLUSION

A simplified pre-conceptional LAC is a simple, safe, and effective method for women with cervical insufficiency. Thus, it is worthy of promotion to assist women with cervical insufficiency in achieving improved obstetric outcomes. Vaginal delivery after LAC is possible once the tape is removed before labor.

The burden of adhesive bowel obstruction requiring surgery in children: a single-center retrospective review

PURPOSE

Investigate causes, predictors, and complications of adhesive bowel obstruction (ABO) necessitating surgery in children.

METHODS

Single-center retrospective review of operative cases classified as 'adhesive bowel obstruction ' between May 2014 and December 2023. Parameters assessed included previous surgeries, operative time (indicative of adhesion extent), length of stay and postoperative complications. Results were statistically analyzed afterward.

RESULTS

We identified 71 patients with ABO; seven had recurrences. Age (11 d-18 y, median 5.9 y) and time after surgery (four days-16 years, median 6.4 months) varied considerably. Preceding appendicitis (16 cases), NEC (seven cases) and gastroschisis (five cases) were most prevalent. Operative time ranged from 43 min to 8.4 h, was longer after previous surgery during infancy (median 177 vs. 124 min), recurrent ABO (median 213 vs. 150 min) and significantly shorter after appendicitis (82 vs. 175 min). ICU stay (median 2 days) and hospital stay (median 11 days) reduced with age. 32 patients (41%) suffered complications, doubling mean lengths of stay. Bowel resection and longer surgery were associated with complications, while age and enterostomy creation were not.

CONCLUSION

ABO is an impactful complication with limited predictors. The high incidence of complications adds to the burden for patients, parents, and health systems.

In situ crosslinked injectable chondroitin sulfate hydrogel for preventing postoperative adhesion

Postoperative adhesion is a common clinical disease caused by surgical trauma, accompanying serious subsequent complications. Current non-surgical drug therapy and biomaterial barrier administration have limited therapeutic effects due to their inherent deficiencies. Therefore, developing a simple, effective, and feasible method to effectively prevent postoperative adhesions after surgical procedures remains a challenge. An injectable chondroitin sulfate complex hydrogel was prepared based on aldehyde-modified chondroitin sulfate (ChS-CHO) and hydrazine-modified chondroitin sulfate (ChS-ADH). The hydrogel showed enhanced strength and good self-healing ability. By using the Schiff base reaction principle that aldehyde group reacts with hydrazide to form hydrazone bond, C-A hydrogel physical barrier is formed at the wound site to reduce the occurrence of postoperative adhesion. There is no use of chemical crosslinkers in the whole reaction system to prepare C-A hydrogel, which has excellent biocompatibility and is safe and non-toxic. The results showed that C-A hydrogel showed excellent mechanical properties, good self-healing, and biocompatibility. The cecal-abdominal wall adhesion model and hepatic adhesion model of rats were constructed respectively to evaluate its preventive effect on postoperative adhesion. The results showed that C-A hydrogel had a more significant preventive effect on postoperative adhesion, and appears to be a promising candidate for postoperative adhesion.

Acute pericardial postischemic inflammatory responses: Characterization using a preclinical porcine model

BACKGROUND

Pericardial fluid (PF) contains cells, proteins, and inflammatory mediators, such as cytokines, chemokines, growth factors, and matrix metalloproteinases. To date, we lack an adequate understanding of the inflammatory response that acute injury elicits in the pericardial space.

OBJECTIVE

To characterize the inflammatory profile in the pericardial space acutely after ischemia/reperfusion.

METHODS

Pigs were used to establish a percutaneous ischemia/reperfusion injury model. PF was removed from pigs at different time points postanesthesia or postischemia/reperfusion. Flow cytometry was used to characterize the immune cell composition of PF, while multiplex analysis was performed on the acellular portion of PF to determine the concentration of inflammatory mediators. There was a minimum of 3 pigs per group.

RESULTS

While native PF mainly comprises macrophages, we show that neutrophils are the predominant inflammatory cell type in the pericardial space after injury. The combination of acute ischemia/reperfusion (IR) and repeatedly accessing the pericardial space significantly increases the concentration of interleukin-1 beta (IL-1β) and interleukin-1 receptor antagonist (IL-1ra). IR significantly increases the pericardial concentration of TGFβ1 but not TGFβ2. We observed that repeated manipulation of the pericardial space can also drive a robust pro-inflammatory response, resulting in a significant increase in immune cells and the accumulation of potent inflammatory mediators in the pericardial space.

CONCLUSION

In the present study, we show that both IR and surgical manipulation can drive robust inflammatory processes in the pericardial space, consisting of an increase in inflammatory cytokines and alteration in the number and composition of immune cells.

The Toll-like receptor 4 antagonist TAK-242 in combination with sodium hyaluronate alleviates postoperative abdominal adhesion in a mouse model

Postoperative abdominal adhesion is one of the most common complications after abdominal surgery. The Toll-like receptor 4 (TLR4) signaling pathway is one of the most common inflammation-related pathways, and it has been demonstrated that TLR4 is highly expressed in adhesive tissues; however, the function of TLR4 in adhesion formation has not yet been studied. In the present study, the expression of TLR4 was first detected by immunohistochemical (IHC) and double-immunofluorescence staining in 40 mice, which were randomly divided into four groups, and sacrificed at 1, 3, 5 and 7 days after surgery. Subsequently, another 40 mice were randomly divided into five groups; with the exception of the sham group, the other groups were modeled and treated with saline that contained DMSO, sodium hyaluronate (HA), TAK-242 or TAK-242 + HA (applied to damaged peritoneal wounds). A total of 7 days after surgery, the mice were sacrificed and specimens were collected. Inflammation was detected by hematoxylin and eosin staining, and ELISA of transforming growth factor- β1 (TGF-β1) and interleukin-6 (IL-6); collagen deposition was examined by Masson staining and IHC staining of α-SMA; and reactive oxygen species (ROS) were detected by ROS staining and malondialdehyde (MDA) assay. The results revealed that TLR4 was highly expressed in the adhesive tissues at 3, 5 and 7 days after surgery. In addition, TAK-242 + HA treatment could reduce abdominal adhesion formation, exhibiting lower Nair's score and inflammation scores, lower TGF-β1 and IL-6 levels, and lower collagen thickness and α-SMA levels compared with those in the control group. In addition, the TAK-242 + HA group had lower levels of ROS and MDA compared with those in the control group. The present study revealed that TLR4 was highly expressed in the process of adhesion formation and its inhibitor, TAK-242, combined with HA, could reduce adhesion formation by reducing inflammation and ROS, and alleviating collagen deposition.

The Role of Natriuretic Peptides in Pericardial Fluid in Predicting Cardiovascular Disorders: A Systematic Review

Atrial and ventricular natriuretic peptides play an important role in the neurohormonal regulation of cardiac function. Plasma levels of these peptides may aid in the diagnosis and prognosis of different cardiac disorders, such as congestive heart failure, ischemic heart disease, and atrial fibrillation. However, the association between elevated pericardial fluid levels of natriuretic peptides and these clinical conditions has not been proven. Databases Medline, EMBASE, Cochrane, ClinicalTrials.gov, and Google Scholar were searched for primary studies evaluating atrial natriuretic peptide, B-type natriuretic peptide, and N-terminal-pro-B-type natriuretic peptide concentrations within the pericardial fluid in various cardiac disorders. A total of 1060 citations were screened, of which 38 studies underwent a full-text evaluation, and 10 were finally included in this review. Sample size varied across studies (n = 8-148), and there was a total of 577 patients across the 10 studies. Findings suggested that pericardial fluid levels of B-type natriuretic peptide and N-terminal-pro-B-type natriuretic peptide but not atrial natriuretic peptide, may correlated with the reported cardiac conditions. Our findings suggest that pericardial fluid levels of natriuretic peptides may correlate with some cardiac disorders such as congestive heart failure and atrial fibrillation. The addition of these peptides to the existing clinical risk stratification scores may be helpful in the early diagnosis and management of these conditions.

Long-Term Efficacy and Safety of Adhesion Prevention Agents in Abdominal and Pelvic Surgeries: A Systematic Review

This systematic review evaluates the long-term efficacy and safety of adhesion prevention agents in abdominal and pelvic surgeries, synthesizing data from randomized controlled trials and meta-analyses. Adhesions, common postoperative complications, can lead to significant morbidity, including chronic pain, infertility, and bowel obstruction. Various agents, including hyaluronic acid-carboxymethylcellulose films and icodextrin solutions, have been developed to mitigate these risks. Our review highlights that agents like bioresorbable membranes (Seprafilm) and icodextrin significantly reduce the incidence and severity of adhesions, particularly in high-risk surgeries. However, certain complications such as anastomotic leaks and infections are associated with some agents, emphasizing the need for careful consideration in clinical decision-making. Additionally, while these agents reduce postoperative morbidity and enhance recovery, further research is needed to assess their long-term impact, particularly regarding fertility outcomes and chronic pain. This review underscores the importance of integrating adhesion prevention agents into surgical protocols, which has the potential to reduce healthcare costs, improve patient outcomes, and optimize postoperative care pathways. Standardization of adhesion prevention practices could further enhance surgical efficiency and patient recovery, particularly in high-risk patient populations and complex surgeries.

Abdominal Gynecologic Procedures in Pancreas Transplant Recipients

INTRODUCTION

With the growing population of pancreas transplant recipients followed long-term, some female recipients are going to require surgical intervention for gynecologic symptoms and pathologies. Currently, there is a lack of literature describing how to approach this population and whether pelvic gynecologic procedures (GYN) can be performed safely given the proximity of the pancreatic (and possibly renal) allograft. In this single-center retrospective analysis, all pancreas transplant recipients that subsequently underwent GYN were reviewed.

METHODS

Subjects were identified by cross-referencing all pancreas transplants performed between January 2003 and December 2022 for any subsequent GYN. Demographics at transplant and GYN, indications and procedure performed, operative time, presence and involvement of a transplant surgeon, complications length of stay, and readmissions were reviewed.

RESULTS

Seventeen patients who underwent a total of 19 GYN after pancreas transplantation were identified. Operations performed included tubal ligation (n = 2), total abdominal hysterectomy with (n = 6) or without bilateral salpingectomy (n = 2), oophorectomy versus cyst drainage (n = 2), bilateral oophorectomy (n = 1), and unilateral (n = 4) versus bilateral (n = 2) salpingectomy. Four were performed through an open laparotomy and 15 were performed laparoscopically. In 11 cases, a transplant surgeon was involved intra-operatively. Eight of the 17 patients developed post-operative complications including post-operative fevers, fluid overload, neutropenia, elevated creatinine (n = 2), nephrolithiasis, urinary tract infection, and incisional hernia. Five required readmission.

CONCLUSION

GYN can be performed safely following pancreas transplantation, but careful planning and the involvement of the transplant surgery team are advised.

Investigation of the Effects of Boric Acid against Post Operative Testicular Adhesion Caused by Experimental Laporotomy in Rats

Post-operative intra-abdominal adhesions, significantly affecting testicular tissue, are a prevalent and serious complication following laparoscopic surgery. This study investigated the efficacy of boric acid, known for its antioxidant, anti-inflammatory, and anti-apoptotic properties, in preventing post-operative testicular adhesions. Forty rats, were divided into four groups: control, laparoscopy (LA), boric acid (BA), and LA + BA. Following laparoscopic surgery, BA treatment was administered for seven days. While the adhesion score was around 3 in the LA group, it was 1 or below in the LA + BA group. Testicular tissues were examined by histopathological and biochemical methods. In testis tissues, in the LA group, malondialdehyde (MDA) levels increased while superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) levels decreased; these parameters normalized with BA treatment. Additionally, the LA group exhibited reduced levels of IL-10, Bcl-2, Kisspeptin-1, and GnRH, alongside elevated levels of inflammatory markers IL-1β, IL-6, TNF-α, JNK, BAX, and Caspase 3. BA treatment significantly restored these levels to normal. In conclusion, oxidative stress, inflammation, and apoptosis in testicular tissues were associated with post-operative testicular adhesions. BA demonstrated potential as an anti-adhesive agent, reducing testicular adhesions and normalizing biochemical and histological parameters following laparoscopic surgery.

Injectable polyamide-amine dendrimer-crosslinked meloxicam-containing poly-γ-glutamic acid hydrogel for prevention of postoperative tissue adhesion through inhibiting inflammatory responses and balancing the fibrinolytic system

Establishing a physical barrier between the peritoneum and the cecum is an effective method to reduce the risk of postoperative abdominal adhesions. Meloxicam (MX), a nonsteroidal anti-inflammatory drug has also been applied to prevent postoperative adhesions. However, its poor water solubility has led to low bioavailability. Herein, we developed an injectable hydrogel as a barrier and drug carrier for simultaneous postoperative adhesion prevention and treatment. A third-generation polyamide-amine dendrimer (G3) was exploited to dynamically combine with MX to increase the solubility and the bioavailability. The formed G3@MX was further used to crosslink with poly-γ-glutamic acid (γ-PGA) to prepare a hydrogel (GP@MX hydrogel) through the amide bonding. In vitro and in vivo experiments evidenced that the hydrogel had good biosafety and biodegradability. More importantly, the prepared hydrogel could control the release of MX, and the released MX is able to inhibit inflammatory responses and balance the fibrinolytic system in the injury tissues in vivo. The tunable rheological and mechanical properties (compressive moduli: from ∼ 57.31 kPa to ∼ 98.68 kPa;) and high anti-oxidant capacity (total free radical scavenging rate of ∼ 94.56 %), in conjunction with their syringeability and biocompatibility, indicate possible opportunities for the development of advanced hydrogels for postoperative tissue adhesions management.

Effect of Compressive Modulus of Porous PVA Hydrogel Coating on the Preventing Adhesion of Polypropylene Mesh

PP mesh is a widely used prosthetic material in hernia repair. However, visceral adhesion is one of the worst complications of this operation. Hence, an anti-adhesive PP mesh is developed by coating porous polyvinyl alcohol (PVA) hydrogel on PP surface via freezing-thawing process method. The compressive modulus of porous PVA hydrogel coating is first regulated by the addition of porogen sodium bicarbonate (NaHCO3) at various quality ratios with PVA. As expected, the porous hydrogel coating displayed modulus more closely resembling that of native abdominal wall tissue. In vitro tests demonstrate the modified PP mesh show superior coating stability, excellent hemocompatibility, and good cytocompatibility. In vivo experiments illustrate that PP mesh coated by the PVA4 hydrogel that mimicked the modulus of native abdominal wall could prevent adhesion effectively. Based on this, the rapamycin (RPM) is loaded into the porous PVA4 hydrogel coating to further improve anti-adhesive property of PP mesh. The Hematoxylin and eosin (H&E) and Masson trichrome (MT) staining results verified that the resulting mesh could alleviate the inflammation response and reduce the deposition of collagen around the implantation zone. The biomimetic mechanical property and anti-adhesive property of modified PP mesh make it a valuable candidate for application in hernioplasty.

Nanofiber Graft Therapy to Prevent Shoulder Stiffness and Adhesions after Rotator Cuff Tendon Repair: A Comprehensive Review

Stiffness and adhesions following rotator cuff tears (RCTs) are common complications that negatively affect surgical outcomes and impede healing, thereby increasing the risk of morbidity and failure of surgical interventions. Tissue engineering, particularly through the use of nanofiber scaffolds, has emerged as a promising regenerative medicine strategy to address these complications. This review critically assesses the efficacy and limitations of nanofiber-based methods in promoting rotator cuff (RC) regeneration and managing postrepair stiffness and adhesions. It also discusses the need for a multidisciplinary approach to advance this field and highlights important considerations for future clinical trials.

A bioinspired injectable antioxidant hydrogel for prevention of postoperative adhesion

Postoperative adhesions, a prevalent complication following abdominal surgery, affect 90% of patients undergoing abdominal surgical procedures. Currently, the primary approach to prevent postoperative adhesions involves physical isolation of the surgical site and surrounding tissues using a hydrogel; however, this method represents a rudimentary strategy. Herein, considering the impact of oxidative stress and free radicals on postoperative adhesion during wound healing, an injectable antioxidant hydrogel, named PU-OHA-D, was successfully synthesized, which is formed by the crosslinking of dopamine-modified oxidized hyaluronic acid (OHA-D) and dihydrazide-terminated polyurethane (PU-ADH) through hydrazone bonding. PU-OHA-D hydrogel possesses versatile characteristics such as rapid gel formation, injectability, self-repair capability and biodegradability. Additionally, they exhibit an excellent ability to clear free radicals and superior tissue adhesion. PU-OHA-D can be injected in situ to form a hydrogel to prevent abdominal wall-cecum adhesion. Importantly, it can effectively eliminate free radicals and inhibit oxidative stress at the wound site. Thereby, it leads to collagen physiological degradation and prevents the occurrence of postoperative adhesions. The bioinspired hydrogel demonstrates its great potential in preventing postoperative adhesion and promoting wound healing.

Surgical Strategies in Reoperation of the Proximal Aorta and Arch for Patients with Previous Frozen Elephant Trunk

Background: The frozen elephant trunk (FET) technique is increasingly utilized for aortic arch replacement in cases of aortic dissections and aneurysms. This rise in usage has led to more patients needing redo aortic surgeries due to progression of existing conditions, FET-related complications, or new valvular/coronary diseases. This article aims to evaluate surgical techniques to minimize risks during these reoperations, including a case study of a complex redo surgery. Methods: A comprehensive examination of surgical strategies was conducted, focusing on preoperative preparation, cannulation site identification, cerebral and cardiac protective measures, and pitfalls to avoid. The importance of adapting to the modified anatomical landscape post-FET is emphasized. A detailed case study of a patient undergoing complex redo FET surgery is included. Results: The article identified key surgical strategies for reoperation in patients with prior FET, highlighting the importance of meticulous preoperative planning and execution. Techniques to minimize risks include detailed imaging for planning, strategic cannulation for optimal perfusion, multidisciplinary approaches as well as careful fail-safe measures. The case study demonstrates the practical application of these strategies in a high-risk scenario. The evidence underscores the necessity for individualized patient management and the development of standardized protocols. Conclusions: The FET technique, while effective for initial aortic arch repairs, often necessitates complex reoperations. Adopting advanced surgical strategies and multidisciplinary planning can significantly mitigate risks associated with these procedures. Future research should focus on refining these techniques and establishing standardized protocols to improve patient outcomes.

Type of Prior Operation Does Not Predict Surgical Intervention for Small Bowel Obstruction

Background: Patients with prior abdominal surgeries are at higher risk for intra-abdominal adhesive tissue formation and subsequently higher risk for small bowel obstruction (SBO).Purpose: In this study, we investigated whether surgical intervention for SBO was more likely following specific types of abdominal surgeries.Research Design: With retrospective chart review, we pooled data from 799 patients, ages 18 to 89, admitted with SBO between 2012 and 2019. Patients were evaluated based on whether they underwent surgery or were managed conservatively. They were further compared with regard to past surgical history by way of type of abdominal surgery (or surgeries) undergone prior to admission.Results: Of the 799 patients admitted for SBO, 206 underwent surgical intervention while 593 were managed nonoperatively. There was no significant difference in number of prior surgeries (2.07 ± 1.56 vs 2.36 ± 2.11, P = .07) or in number of comorbidities (2.39 ± 1.97 vs 2.65 ± 1.93, P = .09) for surgical vs non-surgical intervention. Additionally, of the operations evaluated, no specific type of abdominal surgery predicted need for surgical intervention in the setting of SBO. However, for both surgical and non-surgical intervention following SBO, pelvic surgery was the most common type of prior abdominal surgery (45% vs 43%). There are significantly more female pelvic surgeries in both the operative (91.4% vs 8.6%, P < .0001) and nonoperative groups (89.9% vs 10.2%, P < .0001).Conclusion: Ultimately, no specific type of prior operation predicted the need for surgical intervention in the setting of SBO.

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.

Fat-associated lymphoid clusters: Supporting visceral adipose tissue B cell function in immunity and metabolism

It is now widely understood that visceral adipose tissue (VAT) is a highly active and dynamic organ, with many functions beyond lipid accumulation and storage. In this review, we discuss the immunological role of this tissue, underpinned by the presence of fat-associated lymphoid clusters (FALCs). FALC's distinctive structure and stromal cell composition support a very different immune cell mix to that found in classical secondary lymphoid organs, which underlies their unique functions of filtration, surveillance, innate-like immune responses, and adaptive immunity within the serous cavities. FALCs are important B cell hubs providing B1 cell-mediated frontline protection against infection and supporting B2 cell-adaptative immune responses. Beyond these beneficial immune responses orchestrated by FALCs, immune cells within VAT play important homeostatic role. Dysregulation of immune cells during obesity and aging leads to chronic pathological "metabolic inflammation", which contributes to the development of cardiometabolic diseases. Here, we examine the emerging and complex functions of B cells in VAT homeostasis and the metabolic complications of obesity, highlighting the potential role that FALCs play and emphasize the areas where further research is needed.

Neutrophil Extracellular Traps: A Crucial Factor in Post-Surgical Abdominal Adhesion Formation

Post-surgical abdominal adhesions, although poorly understood, are highly prevalent. The molecular processes underlying their formation remain elusive. This review aims to assess the relationship between neutrophil extracellular traps (NETs) and the generation of postoperative peritoneal adhesions and to discuss methods for mitigating peritoneal adhesions. A keyword or medical subject heading (MeSH) search for all original articles and reviews was performed in PubMed and Google Scholar. It included studies assessing peritoneal adhesion reformation after abdominal surgery from 2003 to 2023. After assessing for eligibility, the selected articles were evaluated using the Critical Appraisal Skills Programme checklist for qualitative research. The search yielded 127 full-text articles for assessment of eligibility, of which 7 studies met our criteria and were subjected to a detailed quality review using the Critical Appraisal Skills Programme (CASP) checklist. The selected studies offer a comprehensive analysis of adhesion pathogenesis with a special focus on the role of neutrophil extracellular traps (NETs) in the development of peritoneal adhesions. Current interventional strategies are examined, including the use of mechanical barriers, advances in regenerative medicine, and targeted molecular therapies. In particular, this review emphasizes the potential of NET-targeted interventions as promising strategies to mitigate postoperative adhesion development. Evidence suggests that in addition to their role in innate defense against infections and autoimmune diseases, NETs also play a crucial role in the formation of peritoneal adhesions after surgery. Therefore, therapeutic strategies that target NETs are emerging as significant considerations for researchers. Continued research is vital to fully elucidate the relationship between NETs and post-surgical adhesion formation to develop effective treatments.

Intra-peritoneal lavage of Zingiber officinale rhizome and its active constituent gingerol impede inflammation, angiogenesis, and fibrosis following post-operative peritoneal adhesion in male rats

Post-operative peritoneal adhesions (PA) are a common and important clinical problem. In this study, we focused on the ameliorative efficacy of ginger and gingerol compounds on surgical-induced peritoneal adhesion, and their strategies that disrupted the PA formation pathways to suppress their incidence. First, liquid chromatography-mass spectrometry (LC-MS) was established to separate and identify several chemical groups of ginger rhizome extract. In the next steps, male Wistar albino rats were randomly selected and divided into various groups, namely sham, control, ginger extract (0.6, 1.8, 5 %w/v), and gingerol (0.05, 0.1, 0.3, and 1 %w/v). Finally, we investigated the macroscopic parameters such as wound healing, body weight as well as spleen height and weight. In addition, visual peritoneal adhesion assessment was performed via Nair et al and Adhesion Scoring Scheme. Moreover, the microscopic parameters and biological assessment was performed via and immunoassays. The present findings revealed significant improvement in wound healing and reduction of the adhesion range, as Nair et al. and Adhesion Scoring Scheme scoring, in both the ginger and gingerol groups compared to the PA group (P < 0.05). Whereas, gingerol (0.3 % w/v) was able to increase the body weight in rats (P < 0.0001) at end stage of experiment. Also, inflammation, angiogenesis, and fibrosis were significantly decreased due to the downregulation of interleukin (IL)-6, tumor necrosis factor (TNF)-α, transforming growth factor (TGF)-β1, vascular endothelial growth factor (VEGF), respectively, in the ginger and gingerol groups compared to the PA group (P < 0.05). In contrast, the levels of IL-10 were increased in the ginger and gingerol groups compared to the control group (P < 0.01). Our results proved that ginger rhizome and gingerol, as novel therapeutic compounds, could be used to prevent PA for their beneficial anti-inflammatory as well as anti-fibrosis properties in clinical trials. However, further clinical studies are required to approve the effectiveness of ginger and gingerol.

Effects of pioglitazone and metformin on abdominal adhesion formation in an experimental model

BACKGROUND

This study evaluated the use of metformin or pioglitazone in preventing or reducing the development of post-operative intra-abdominal adhesion (PIAA) by employing histopathological, immunohistochemical, and biochemical analyses in an experimental adhesion model.

METHODS

Fifty Wistar-Albino rats were divided into five groups: Group I (Control), Group II (Sham Treatment), Group III (Hy-aluronic Acid), Group IV (Metformin), and Group V (Pioglitazone). Adhesions were induced in the experimental groups, except for the sham group, using the scraping method. After 10 days, rats were euthanized for evaluation. Macroscopic adhesion degrees were assessed using Nair's scoring system. Immunohistochemical and enzyme-linked immunosorbent assay (ELISA) methods were utilized to assess serum, peritoneal lavage, and intestinal tissue samples. Fructosamine, interleukin-6 (IL-6), transforming growth factor-beta (TGF-β), and fibronectin levels were measured in serum and peritoneal lavage samples.

RESULTS

The groups exhibited similar Nair scores and Type I or Type III Collagen staining scores (all, p>0.05). Pioglitazone significantly reduced serum IL-6 and TGF-β levels compared to controls (p=0.002 and p=0.008, respectively). Both metformin and pioglitazone groups showed elevated IL-6 in peritoneal lavage relative to controls, while fibronectin levels in the lavage were lower in pioglitazone-treated rats compared to the sham group (all, p<0.005).

CONCLUSION

Pioglitazone, but not metformin, demonstrated a positive biochemical impact on preventing PIAA formation in an experimental rat model, although histological impacts were not observed. Further experimental studies employing different dose/duration regimens of pioglitazone are needed to enhance our understanding of its effect on PIAA formation.

Laparoscopic application of sodium hyaluronate-carboxymethylcellulose barrier in abdominopelvic surgery: A Preferred Reporting Items for Systematic Reviews and Meta-Analyses for Systematic Review Protocols-compliant systematic review and meta-analysis

BACKGROUND

We aimed to evaluate the incidence of postoperative adhesion formation and adhesion-related consequences (eg, bowel obstruction) after placement of a sodium hyaluronate-carboxymethylcellulose adhesion barrier after laparoscopic abdominopelvic surgery.

METHODS

In this systematic review and meta-analysis, we searched the Medical Literature Analysis and Retrieval System Online and Embase via Ovid, Cochrane Central Register of Controlled Trials, ScienceDirect, BIOSIS Previews, Cumulative Index to Nursing and Allied Health Literature, and Clinical Trial Registries. A manual search (eg, Google Scholar and professional association websites) was also conducted to supplement the electronic database results. Two reviewers independently identified relevant studies based on inclusion and exclusion criteria and extracted data.

RESULTS

A total of 28 studies were included in the systematic qualitative review. Three of the 28 studies included had comparable outcome measures, interventions, and control groups, allowing the pooling of study data. A total of 938 patients (490 patients in the sodium hyaluronate-carboxymethylcellulose barrier group and 448 in the no adhesion barrier group) from these 3 studies were included in the meta-analyses, which found the incidence of bowel obstruction was significantly lower (65% risk reduction) in the sodium hyaluronate-carboxymethylcellulose barrier group compared with the control group (relative risk = 0.35; 95% confidence interval, 0.19-0.63; P = .005) with extremely low heterogeneity between studies (I2 = 0; P = .41). The placement of sodium hyaluronate-carboxymethylcellulose barrier laparoscopically did not create new safety signals nor did it increase the incidence of adverse events.

CONCLUSION

Our meta-analysis found that laparoscopic application of a sodium hyaluronate-carboxymethylcellulose barrier in abdominopelvic surgery reduces the risk of bowel obstruction where applied during the early postoperative phase.

A Laparoscopically Compatible Rapid-Adhesion Bioadhesive for Asymmetric Adhesion, Non-Pressing Hemostasis, and Seamless Seal

Bioadhesive hydrogels offer unprecedented opportunities in hemostatic agents and tissue sealing; however, the application of existing bioadhesive hydrogels through narrow spaces to achieve strong adhesion in fluid-rich physiological environments is challenged either by undesired indiscriminate adhesion or weak wet tissue adhesion. Here, a laparoscopically compatible asymmetric adhesive hydrogel (aAH) composed of sprayable adhesive hydrogel powders and injectable anti-adhesive glue is proposed for hemostasis and to seal the bloody tissues in a non-pressing way, allowing for preventing postoperative adhesion. The powders can seed on the irregular bloody wound to rapidly absorb interfacial fluid, crosslink, and form an adhesive hydrogel to hemostatic seal (blood clotting time and tissue sealing in 10 s, ≈200 mm Hg of burst pressure in sealed porcine tissues). The aAH can be simply formed by crosslinking the upper powder with injectable glue to prevent postoperative adhesion (adhesive strength as low as 1 kPa). The aAH outperforms commercial hemostatic agents and sealants in the sealing of bleeding organs in live rats, demonstrating superior anti-adhesive efficiency. Further, the hemostatic seamless sealing by aAH succeeds in shortening the time of warm ischemia, decreasing the blood loss, and reducing the possibility of rebleeding in the porcine laparoscopic partial nephrectomy model.

Tissue-mimicking composite barrier membranes to prevent abdominal adhesion formation after surgery

Postoperative abdominal adhesions often occur after abdominal surgery; barrier membranes which mimic peritoneal tissue can be constructed to prevent abdominal adhesions. To this end, silk fibroin (SF) sheets were coated with polyvinyl alcohol (PVA) and agarose (AGA) at PVA:AGA ratios of 100:0, 70:30, 50:50, 30:70, and 0:100 to create a composite anti-adhesive barrier and allow us to identify a suitable coating ratio. The membranes were characterized in terms of their molecular organization, structure, and morphology using Fourier transform Infrared spectrometer (FT-IR), differential scanning calorimeter (DSC), and scanning electron microscope (SEM), respectively. The physical and mechanical properties of the membranes and their biological performance (i.e., fibroblast proliferation and invasion) were tested in vitro. Each membrane showed both smooth and rough surface characteristics. Membranes coated with PVA:AGA at ratios of 100:0, 70:30, 50:50, and 30:70 exhibited more -OH and amide III moieties than those coated with 0:100 PVA:AGA, which consequently affected structural organization, degradation, and fibroblast viability. The 0:100 PVA:AGA-coated degraded the fastest. Barrier membranes coated with 100:0 and 70:30 PVA: AGA demonstrated reduced fibroblast proliferation and attachment. The membrane coated with 70:30 PVA:AGA exhibited a stable appearance, and did not curl under wet conditions. Therefore, SF sheets coated with 70:30 PVA:AGA show promise as anti-adhesive barrier membranes for further development.

Advanced postoperative tissue antiadhesive membranes enabled with electrospun nanofibers

Tissue adhesion is one of the most common postoperative complications, which is frequently accompanied by inflammation, pain, and even dyskinesia, significantly reducing the quality of life of patients. Thus, to prevent the formation of tissue adhesions, various strategies have been explored. Among these methods, placing anti-adhesion membranes over the injured site to separate the wound from surrounding tissues is a simple and prominently favored method. Recently, electrospun nanofibers have been the most frequently investigated antiadhesive membranes due to their tunable porous structure and high porosities. They not only can act as an essential barrier and functional carrier system but also allow for high permeability and nutrient transport, showing great potential for preventing tissue adhesion. Herein, we provide a short review of the most recent applications of electrospun nanofibrous antiadhesive membranes in tendons, the abdominal cavity, dural sac, pericardium, and meninges. Firstly, each section highlights the most representative examples and they are sorted based on the latest progress of related research. Moreover, the design principles, preparation strategies, overall performances, and existing problems are highlighted and evaluated. Finally, the current challenges and several future ways to develop electrospun nanofibrous antiadhesive membranes are proposed. The systematic discussion and proposed directions can shed light on ideas and guide the reasonable design of electrospun nanofibrous membranes, contributing to the development of exceptional tissue anti-adhesive materials in the foreseeable future.

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.

Biocompatible Nanocomposites for Postoperative Adhesion: A State-of-the-Art Review

To reduce and prevent postsurgical adhesions, a variety of scientific approaches have been suggested and applied. This includes the use of advanced therapies like tissue-engineered (TE) biomaterials and scaffolds. Currently, biocompatible antiadhesive constructs play a pivotal role in managing postoperative adhesions and several biopolymer-based products, namely hyaluronic acid (HA) and polyethylene glycol (PEG), are available on the market in different forms (e.g., sprays, hydrogels). TE polymeric constructs are usually associated with critical limitations like poor biocompatibility and mechanical properties. Hence, biocompatible nanocomposites have emerged as an advanced therapy for postoperative adhesion treatment, with hydrogels and electrospun nanofibers among the most utilized antiadhesive nanocomposites for in vitro and in vivo experiments. Recent studies have revealed that nanocomposites can be engineered to generate smart three-dimensional (3D) scaffolds that can respond to different stimuli, such as pH changes. Additionally, nanocomposites can act as multifunctional materials for the prevention of adhesions and bacterial infections, as well as tissue healing acceleration. Still, more research is needed to reveal the clinical potential of nanocomposite constructs and the possible success of nanocomposite-based products in the biomedical market.

Improving the Physical Properties of Starch-Based Powders for Potential Anti-Adhesion Applications

Postoperative adhesion is one of the most common complications that occur during and after surgery; thus, materials that can prevent adhesion are often applied. Starch powders with a high water absorption capacity are preferred, and many studies have focused on increasing the water absorption of modified starches, as native starch powders display poor water-holding capacities. The effects of salts on the physical properties of acetylated distarch phosphate potato starch powders were investigated here. Changes in functional groups, the crystal structures of modified starch, particle morphologies, water absorption, viscosity, and in vivo adhesion were investigated. The results showed that salts greatly improved the water absorption and viscosity of acetylated distarch phosphate potato starch powders. Among the three different salt-modified starch powders, NaCl-modified starch powders displayed higher water absorption and viscosity and demonstrated better in vivo anti-adhesion performance. The results of this study propose a potential biomaterial that may function as an anti-adhesive, potentially leading to reduced surgical risks and a better quality of life for patients.

A Zwitterionic Hydrogel with Anti-Oxidative and Anti-Inflammatory Properties for the Prevention of Peritoneal Adhesion by Inhibiting Mesothelial-Mesenchymal Transition

Postoperative peritoneal adhesion is a serious clinical complication. Various hydrogel barriers have been developed to prevent peritoneal adhesion. However, it remains a challenge to design a hydrogel with desirable physicochemical properties and bioactivities. In this study, a zwitterionic polysaccharide-based multifunctional hydrogel is developed using epigallocatechin-3-gallate (EGCG) to prevent postoperative abdominal adhesion. This hydrogel is simple to use and has desirable properties, such as excellent injectability, self-healing, and non-swelling properties. The hydrogel also has ultralow fouling capabilities, such as superior bactericidal performance, cell and protein adhesion, and low immunogenicity resistance. Moreover, the hydrogel exhibits good antioxidant activity, which is attributed to the integration of EGCG. Furthermore, the detailed mechanism from in vivo and in vitro experimental studies illustrates that hydrogel compositions can synergistically prevent adhesion formation through multiple pathways, including anti-inflammatory and antioxidant capabilities and inhibition effects on the mesothelial-mesenchymal transition (MMT) process induced by transforming growth factor (TGF-β). In summary, this zwitterionic multifunctional hydrogel has great potential to prevent postoperative adhesion formation in the clinical setting.

Cardiac surgery elicits pericardial inflammatory responses that are distinct compared with postcardiopulmonary bypass systemic inflammation

Objectives

Cardiac surgery using cardiopulmonary bypass contributes to a robust systemic inflammatory process. Local intrapericardial postsurgical inflammation is believed to trigger important clinical implications, such as postoperative atrial fibrillation and postsurgical intrathoracic adhesions. Immune mediators in the pericardial space may underlie such complications.

Methods

In this prospective pilot clinical study, 12 patients undergoing isolated coronary artery bypass graft surgery were enrolled. Native pericardial fluid and venous blood samples (baseline) were collected immediately after pericardiotomy. Postoperative pericardial fluid and venous blood samples were collected 48-hours after cardiopulmonary bypass and compared with baseline. Flow cytometry determined proportions of specific immune cells, whereas multiplex analysis probed for inflammatory mediators.

Results

Neutrophils are the predominant cells in both the pericardial space and peripheral blood postoperatively. There are significantly more CD163lo macrophages in blood compared with pericardial effluent after surgery. Although there are significantly more CD163hi macrophages in native pericardial fluid compared with baseline blood, after surgery there are significantly fewer of these cells present in the pericardial space compared with blood. Postoperatively, concentration of interleukin receptor antagonist 6, and interleukin 8 were significantly higher in the pericardial space compared with blood. After surgery, compared with blood, the pericardial space has a significantly higher concentration of matrix metalloproteinase 3, matrix metalloproteinase 8, and matrix metalloproteinase 9. The same trend was observed with transformational growth factor β.

Conclusions

Cardiac surgery elicits an inflammatory response in the pericardial space, which differs from systemic inflammatory responses. Future work should determine whether or not this distinct local inflammatory response contributes to postsurgical complications and could be modified to influence clinical outcomes.

Perspectives in adhesion prevention in gynaecological surgery

Adhesions are a frequent, clinically relevant, and often costly complication of surgery that can develop in any body location regardless of the type of surgical procedure. Adhesions result from surgical trauma inducing inflammatory and coagulation processes and to date cannot be entirely prevented. However, the extent of adhesion formation can be reduced by using good surgical technique and the use of anti-inflammatory drugs, haemostats, and barrier agents. Strategies are needed in the short-, medium- and longer-term to improve the prevention of adhesions. In the short-term, efforts are needed to increase the awareness amongst surgeons and patients about the potential risks and burden of surgically induced adhesions. To aid this in the medium- term, a risk score to identify patients at high risk of adhesion formation is being developed and validated. Furthermore, available potentially preventive measures need to be highlighted. Both clinical and health economic evaluations need to be undertaken to support the broad adoption of such measures. In the longer- term, a greater understanding of the pathogenic processes leading to the formation of adhesions is needed to help identify effective, future treatments to reliably prevent adhesions from forming and lyse existing ones.

Impact of Previous Conventional Cardiac Surgery on the Clinical Outcomes After Heart Transplantation

The impact of the type, purpose, and timing of prior surgery on heart transplantation (HT) remains unclear. This study investigated the influence of conventional cardiac surgery (PCCS) on HT outcomes. This study analyzed HTs performed between 1999 and 2019 at a single institution. Patients were categorized into two groups: those with and without PCCS. Short-term outcomes, including post-transplant complications and mortality rates, were evaluated. Cox proportional and Kaplan-Meier survival analyses were used to identify risk factors for mortality and assess long-term survival, respectively. Of 368 patients, 29% had PCCS. Patients with PCCS had a higher incidence of post-transplant complications. The in-hospital and 1 year mortality rates were higher in the PCCS group. PCCS and cardiopulmonary bypass time were significant risk factors for 1 year mortality (hazard ratios = 2.485 and 1.005, respectively). The long-term survival rates were lower in the PCCS group, particularly in the first year. In sub-analysis, patients with ischemic cardiomyopathy and PCCS had the poorest outcomes. The era of surgery and timing of PCCS in relation to HT did not significantly impact outcomes. In conclusion, PCCS worsen the HT outcomes, especially in patients with ischemic etiology. However, the timing of PCCS and era of HT did not significantly affect this concern.

Partial volvulus, entrapment, and extraluminal obstruction of the jejunum in a cat

A 2-year-old, spayed female, domestic shorthair cat was presented in compensated hypovolemic shock after 24 h of anorexia, vomiting, and lethargy. An enterotomy had been performed at 9 mo of age to remove a foreign body. Due to inconclusive findings on abdominal imaging, an exploratory laparotomy was done. An adhesion at the root of the mesentery, likely associated with the previous surgery, had resulted in partial volvulus, entrapment, and extraluminal obstruction of the jejunum. Transection of the adhesion allowed repositioning of the bowel without the need for resection. The cat was discharged from the hospital 7 d postoperatively. Adhesions have not previously been reported to cause small bowel volvulus in cats. Key clinical message: Abdominal adhesions as a cause of clinical disease in cats have apparently not been reported. This case report demonstrates how malposition of the gastrointestinal tract, secondary to adhesions, should be included as a differential diagnosis for feline patients presenting with acute abdomens. Previous abdominal surgery is a risk factor for development of adhesions. This case emphasized the importance of Halsted's principles of surgery to reduce the risk of postoperative adhesions, even in species not predisposed to forming adhesions.

Pericardial Inflammatory Mediators That Can Drive Postoperative Atrial Fibrillation in Cardiac Surgery Patients

Postoperative atrial fibrillation (POAF) is a common dysrhythmia that affects a significant number of patients undergoing cardiac surgery. Many studies aim to better understand this complex postsurgical complication by analysing circulating biomarkers in patients who develop POAF. More recently, the pericardial space was shown to contain inflammatory mediators that could trigger POAF. In this review we summarise recent studies that examine the immune mediators present in the pericardial space and their potential implications for the pathophysiology of POAF in cardiac surgery patients. Ongoing research in this area should better delineate the multifactorial etiology of POAF, where specific markers may be targeted to reduce the incidence of POAF and improve outcomes for this patient population.

Pericardial Immune Cells and Their Evolving Role in Cardiovascular Pathophysiology

The pericardium plays several homeostatic roles to support and maintain everyday cardiac function. Recent advances in techniques and experimental models have allowed for further exploration into the cellular contents of the pericardium itself. Of particular interest are the various immune cell populations present in the space within the pericardial fluid and fat. In contrast to immune cells of the comparable pleura, peritoneum and heart, pericardial immune cells appear to be distinct in their function and phenotype. Specifically, recent work has suggested these cells play critical roles in an array of pathophysiological conditions including myocardial infarction, pericarditis, and post-cardiac surgery complications. In this review, we spotlight the pericardial immune cells currently identified in mice and humans, the pathophysiological role of these cells, and the clinical significance of the immunocardiology axis in cardiovascular health.

Multifunctional Sodium Hyaluronate/Chitosan Foam Used as an Absorbable Hemostatic Material

Absorbable hemostatic materials have great potential in clinical hemostasis. However, their single coagulation mechanism, long degradation cycles, and limited functionality mean that they have restricted applications. Here, we prepared a sodium hyaluronate/carboxymethyl chitosan absorbable hemostatic foam (SHCF) by combining high-molecular-weight polysaccharide sodium hyaluronate with carboxymethyl chitosan via hydrogen bonding. SHCFs have rapid liquid absorption performance and can enrich blood cells. They transform into a gel when it they come into contact with blood, and are more easily degraded in this state. Meanwhile, SHCFs have multiple coagulation effects and promote hemostasis. In a rabbit liver bleeding model, SHCFs reduced the hemostatic time by 85% and blood loss by 80%. In three severe and complex bleeding models of porcine liver injury, uterine wall injury, and bone injury, bleeding was well-controlled and anti-tissue adhesion effects were observed. In addition, degradation metabolism studies show that SHCFs are 93% degraded within one day and almost completely metabolized within three weeks. The absorbable hemostatic foam developed in this study is multifunctional; with rapid hemostasis, anti-adhesion, and rapid degradation properties, it has great clinical potential for in vivo hemostasis.

Peritoneal Adhesions in Osteopathic Medicine: Theory, Part 1

Peritoneal adhesions form as a result of trauma to the abdomen, injuries resulting from surgery, and infections. These tissutal neoformations are innervated and vascularized, and with lymphatic vessels, adherence becomes a new and independent structure, capable of negatively influencing visceral functions. Adherent neogenesis can be asymptomatic or can be a source of pain, limiting the patient's quality of life. Although adhesiolysis remains the elective approach to eliminate adhesions, this therapeutic route prepares the peritoneal anatomical area to recur. The article reviews information on adhesion formation and peritoneal anatomy, probable subjective predispositions, and pathways that carry nociception. The text aims to be a theoretical basis for making new treatment suggestions for non-invasive osteopathic medicine, through a second part will be discussed in another article.

Piperine Liposome-Embedded in Hyaluronan Hydrogel as an Effective Platform for Prevention of Postoperative Peritoneal Adhesion

This study aimed to prepare piperine (PIP) loaded liposomes in hyaluronic acid (HA) hydrogel to provide a hybrid superstructure for postoperative adhesion prevention. Liposomes were prepared using thin-film hydration method. The optimised formulation was characterised by size, SEM, TEM, FTIR, encapsulation efficiency (EE)% (w/w), and release pattern. Liposome-in-hydrogel formulation was investigated by rheology, SEM, and release studies. The efficacy was evaluated in a rat peritoneal abrasion model. EE% (w/w) increased with increasing lipid concentration from 10 to 30; however, a higher percentage of Chol reduced EE% (w/w). The optimised liposome (EE: 68.10 ± 4.18% (w/w), average diameter: 513 ± 14.67 nm, PDI: 0.15 ± 0.04) was used for hydrogel embedding. No sign of adhesion in 5/8 rats and no collagen deposition confirmed the in vivo effectiveness of the optimised formulation. Overall, providing a sustained delivery of PIP, the developed liposome-in-hydrogel formulation can be a promising carrier to prevent postoperative adhesion.

Vermiform Appendix within Post-Laparoscopic Incisional Hernia: A Unique Case Report and Literature Review

Background: Appendicitis within incisional hernia is an extraordinarily rare postoperative complication with an incidence range from 0.08 to 1%. From the 14 cases that we found in the English literature, only three present appendixes vermiform in incisional hernia followed by laparoscopic surgery. Only two cases are treated minimally invasively by the laparoscopic approach. Case presentation: We introduce a 65-year-old man who had a laparoscopic sigmoid colon resection and had a lump found at the 12 mm trocar site in the right iliac area in the late postoperative phase. There were no complaints from the patient. A vermiform appendix was unexpectedly discovered in the sac of that incisional hernia during control CT scans performed by chemotherapists. Laparoscopic hernia repair without appendectomy was performed. Postoperative outcomes were excellent. Conclusions: Because of low incidence and a lack of distinctive clinical presentation of appendicitis within incisional hernia, there is a risk of delayed perioperative diagnosis and treatment. A CT scan might play an important role in verifying the diagnosis early. For better postoperative outcomes, if possible, laparoscopic surgery should be chosen.

Polypropylene composite hernia mesh with anti-adhesion layer composed of PVA hydrogel and liposomes drug delivery system

Polypropylene (PP) mesh has been widely used in hernia repair as prosthesis material owing to its excellent balanced biocompatibility and mechanical properties. However, abdominal adhesion between the visceral and PP mesh is still a major problem. Therefore, anti-adhesive PP mesh was designed with poly(vinyl alcohol) (PVA) hydrogel and liposomes drug delivery system. First, PVA hydrogel coating was formed on the surface of PP mesh with freezing-thawing processing cycles (FTP). Subsequently, the lyophilized PVA₁₀-c-PP was immersed in rapamycin (RPM)-loaded liposome solution until swelling equilibrated to obtain the anti-adhesion mesh RPM@LPS/PVA₁₀-c-PP. It was demonstrated that the hydrogel coating can stably fix on the surface of PP mesh even after immersed in PBS solution at 37 °C or 40 °C for up to 30 days. In vitro cell tests revealed the excellent cytocompatibility and the potential to inhibit cell adhesion of the modified PP mesh. Moreover, the anti-adhesive effects of the RPM@LPS/PVA₁₀-c-PP mesh was evaluated through in vivo experiments. The RPM@LPS/PVA₁₀-c-PP mesh exhibited less adhesion than original PP mesh throughout the duration of implantation. At 30 days, the adhesion score of RPM@LPS/PVA₁₀-c-PP mesh was 1.37 ± 0.75, however the original PP was 3 ± 0.71. Furthermore, the results of H&E and Masson trichrome staining proved that the RPM@LPS/PVA₁₀-c-PP mesh showed slighter inflammation response and significant looser fibrous tissue surrounded the PP filaments as compared to the native PP. The current findings manifested that this type of RPM@LPS/PVA₁₀-c-PP might be a potential candidate for anti-adhesion treatment. DATA AVAILABILITY: Data will be made available on request.

Lumbrokinase, a Fibrinolytic Enzyme, Prevents Intra-Abdominal Adhesion by Inhibiting the Migrative and Adhesive Activities of Fibroblast via Attenuation of the AP-1/ICAM-1 Signaling Pathway

Intra-abdominal adhesion is a complication following abdominal surgery caused by the suppression of fibrinolytic activity and aggravated fibroblast invasion of the injured area, which may lead to chronic illnesses such as chronic pain, intestinal obstruction, and female infertility. This study hypothesized that lumbrokinase, a fibrinolytic enzyme extracted from the earthworm, supports the wound healing process. Therefore, we assessed the effect of lumbrokinase on intra-abdominal adhesion. Lumbrokinase treatment significantly decreased the severity and the area of intra-abdominal adhesion in vivo in a dose-dependent manner compared with the controls (untreated and hyaluronate-treated). Lumbrokinase-associated adverse effects were not observed. Immunohistochemical analysis of adhesion tissues revealed a loosened adhesive band between tissues, coupled with significantly decreased peritoneal thickening in the lumbrokinase-treated group versus the control group. Three-dimensional spheroid, MTT, and scratch wound migration assays using the IMR-90 human fibroblast cell line demonstrated that lumbrokinase significantly attenuated the migration and adhesive activity of fibroblasts without compromising cell proliferation. The luciferase assay and western blot analysis showed that lumbrokinase inhibited the AP-1/ICAM-1 cell adhesion signaling pathway. Therefore, lumbrokinase decreases intra-abdominal adhesion and peritoneal thickening by augmenting fibrinolytic action and inhibiting fibroblast migration and adhesive activity via attenuation of the AP-1/ICAM-1 signaling pathway. Lumbrokinase is thus a promising agent to prevent intra-abdominal adhesion.

Comprehensive characterization of the postoperative pericardial inflammatory response: Potential implications for clinical outcomes

Objective

There is a paucity of data on the inflammatory response that takes place in the pericardial space after cardiac surgery. This study provides a comprehensive assessment of the local postoperative inflammatory response.

Methods

Forty-three patients underwent cardiotomy, where native pericardial fluid was aspirated and compared with postoperative pericardial effluent collected at 4, 24, and 48 hours' postcardiopulmonary bypass. Flow cytometry was used to define the levels and proportions of specific immune cells. Samples were also probed for concentrations of inflammatory cytokines, matrix metalloproteinases (MMPs), and tissue inhibitors of metalloproteinases (TIMPs).

Results

Preoperatively, the pericardial space mainly contains macrophages and T cells. However, the postsurgical pericardial space was populated predominately by neutrophils, which constituted almost 80% of immune cells present, and peaked at 24 hours. When surgical approaches were compared, minimally invasive surgery was associated with fewer neutrophils in the pericardial space at 4 hours' postsurgery. Analysis of the intrapericardial concentrations of inflammatory mediators showed interleukin-6, MMP-9, and TIMP-1 to be highest postsurgery. Over time, MMP-9 concentrations decreased significantly, whereas TIMP-1 levels increased, resulting in a significant reduction of the ratio of MMP:TIMP after surgery, suggesting that active inflammatory processes may influence extracellular matrix remodeling.

Conclusions

These results show that cardiac surgery elicits profound alterations in the immune cell profile in the pericardial space. Defining the cellular and molecular mediators that drive pericardial-specific postoperative inflammatory processes may allow for targeted therapies to reduce immune-mediated complications.