Reduce Adhesion Formation Research Articles

Coated Polypropylene Mesh Is Associated With Increased Infection in Abdominal Wall Reconstruction.

Barrier-coated meshes were designed to reduce adhesion formation between mesh and the surrounding viscera. There have been questions raised but little data to determine if rapidly absorbable coatings pose an increased risk of infection. The objective of this study was to determine if a difference exists in wound and mesh infection rates between coated and uncoated polypropylene mesh in patients undergoing open ventral hernia repair. A prospective, institutional database at a tertiary hernia center identified patients undergoing open preperitoneal ventral hernia repair (OPPVHR) with polypropylene mesh in CDC class 1 and 2 wounds. Using propensity score matching, an absorbable, coated and uncoated group were matched based on age, comorbidities, wound class, defect size, and mesh size. There were 265 patients each in the matched coated and uncoated mesh groups for a total of 530 patients. Postoperative wound infections (10.9% versus 4.6%, P=0.01) and need for IV antibiotics (10.5% versus 4.3%, P=0.01) were significantly higher in the coated group. There was an increase in mesh infection for the coated group (3.4% versus 0.4%, P=0.02), and of those developing a mesh infection, 60.0% eventually required mesh excision. Coated mesh was associated with increased postoperative wound and mesh infection following OPPVHR. An uncoated mesh should be strongly considered when placed in an extraperitoneal location.

New Use of an Absorbable Adhesion Barrier (INTERCEED) for Temporary Diverting Ileostomy in Minimally Invasive Rectal Surgery

Abstract Objectives Sometimes, severe adhesion occurs between the rectus abdominis muscle and the ileal intestinal limbs after temporary diverting ileostomy. This can make ileostomy reversal difficult. The aim of the present study is to assess whether absorbable adhesion barrier made of oxidized regenerated cellulose (INTERCEED) could contribute to improved surgical outcomes in stoma reversal. Methods This was a single-institutional retrospective study. A total of 36 consecutive patients who underwent ileostomy reversal by a single surgeon were retrospectively reviewed. INTERCEED was inserted between the ileal limbs and the rectus abdominis muscle at the time of ileostomy creation in 12 patients. Surgical outcomes of the ileostomy reversal were compared between patients treated with and without INTERCEED. Results The degree of adhesion formation between the ileal limbs and the rectus abdominis muscles, operating time, and estimated blood loss were significantly reduced in patients treated with INTERCEED compared with those treated by the conventional approach. None of the patients in the INTERCEED group had postoperative complications after the initial surgery and ileostomy reversal. Conclusions INTERCEED is suitable for insertion between the ileal limbs and the rectus abdominis muscles because of its softness and flexibility. The use of INTERCEED for diverting ileostomy contributes to reduced adhesion formation, operative time, and blood loss in patients, and further research is needed to confirm our results.

Ultra-Fine Polyethylene Hernia Meshes Improve Biocompatibility and Reduce Intraperitoneal Adhesions in IPOM Position in Animal Models.

(1) Introduction: The intraperitoneal onlay mesh technique (IPOM) is widely used to repair incisional hernias. This method has advantages but suffers from complications due to intraperitoneal adhesion formation between the mesh and intestine. An ideal mesh minimizes adhesions and shows good biocompatibility. To address this, newly developed multifilamentous polyethylene (PET) meshes were constructed from sub-macrophage-sized monofilaments and studied regarding biocompatibility and adhesion formation. (2) Methods: We investigated fine (FPET, 72 filaments, 11 µm diameter each) and ultra-fine multifilament (UFPET, 700 filaments, 3 µm diameter each) polyethylene meshes for biocompatibility in subcutaneous implantation in rats. Adhesion formation was analyzed in the IPOM position in rabbits. Geometrically identical mono-filamentous polypropylene (PP) Bard Soft® PP meshes were used for comparison. Histologic and immune-histologic foreign body reactions were assessed in 48 rats after 7 or 21 days (four mesh types, with two different mesh types per rat; n = 6 per mesh type). Additionally, two different mesh types each were placed in the IPOM position in 24 rabbits to compile the Diamond peritoneal adhesion score after the same timeframes. The biocompatibility and adhesion score differences were analyzed with the Kruskal–Wallis nonparametric statistical test. (3) Results: Overall, FPET and, especially, UFPET showed significantly smaller foreign body granulomas compared to PP meshes. Longer observation periods enhanced the differences. Immunohistology showed no significant differences in the cellular immune response and proliferation. UFPET demonstrated significantly reduced peritoneal adhesion formation compared to all other tested meshes after 21 days. (4) Conclusions: Overall, FPET and, especially, UFPET demonstrated their suitability for IPOM hernia meshes in animal models by improving major aspects of the foreign body reaction and reducing adhesion formation.

Intraperitoneal microbial contamination drives post-surgical peritoneal adhesions by mesothelial EGFR-signaling

Abstract Objective Abdominal surgeries are lifesaving procedures but can be complicated by the formation of peritoneal adhesions, intra-abdominal scars that cause intestinal obstruction, pain, infertility, and significant health costs. Despite this burden, the mechanisms underlying adhesion formation remain unclear and no cure exists. Here, ask how contamination of gut microbes influences post-surgical adhesion formation. Methods We make use of an experimental mouse model that allows to investigate how wound repair and adhesion formation differs between sterile injury vs. sterile injury in combination with microbial contamination. We use genetic lineage tracing, bulk- and single-cell RNA-Sequencing to identify potential mechanisms of the observed differences. Next, we use two human cohort studies to confirm the target identified by RNA-Sequencing. Finally, the identified targets are experimentally confirmed by going back to the mouse model. Results We show that adhesion myofibroblasts arise from the mesothelium. This transformation is driven by epidermal growth factor receptor (EGFR) signaling. The EGFR ligands amphiregulin and heparin-binding epidermal growth factor, are sufficient to induce these changes. Correspondingly, EGFR inhibition leads to a significant reduction of adhesion formation in mice. Adhesions isolated from human patients are enriched in EGFR positive cells of mesothelial origin and human mesothelium shows an increase of mesothelial EGFR expression during bacterial peritonitis. Conclusion Bacterial contamination drives adhesion formation through mesothelial EGFR signaling. This mechanism may represent a therapeutic target for the prevention of adhesions after intra-abdominal surgery.

The Use of Self-Assembling Peptides (PuraStat™) in Functional Endoscopic Sinus Surgery for Haemostasis and Reducing Adhesion Formation. A Case Series of 94 Patients

Introduction: Functional endoscopic sinus surgery (FESS) is a treatment option for patients with chronic rhinosinusitis. Bleeding and adhesions are common complications postoperatively. Objective: To assess the effectiveness of PuraStat™ (3-D Matrix Medical Technology Pty Ltd, Melbourne, Australia) for use in FESS to achieve haemostasis and reduce adhesion formation. Materials and Methods: A retrospective chart review over four years was performed on 94 patients undergoing FESS by a single surgeon, using PuraStat™ in absence of nasal packing. Results: Twenty-eight patients underwent complete FESS and 66 cases limited FESS most often combined with nasal surgery. Six patients had bleeding postoperatively, of which only four required additional treatment (4.25%). Twenty-three patients (24.47%) required debridement during the follow up, simply performed by suction for 13 or by scissors for 10. No patient required revision surgery for adhesion. Conclusion: PuraStat™ used for the first time in context of FESS seems to be effective in achieving haemostasis, reducing adhesion formation, and avoiding nasal packing in most patients.

E8002 Reduces Adhesion Formation and Improves Joint Mobility in a Rat Model of Knee Arthrofibrosis.

Knee arthrofibrosis is a common complication of knee surgery, caused by excessive scar tissue, which results in functional disability. However, no curative treatment has been established. E8002 is an anti-adhesion material that contains L-ascorbic acid, an antioxidant. We aimed to evaluate the efficacy of E8002 for the prevention of knee arthrofibrosis in a rat model, comprising injury to the surface of the femur and quadriceps muscle 1 cm proximal to the patella. Sixteen male, 8-week-old Sprague Dawley rats were studied: in the Adhesion group, haemorrhagic injury was induced to the quadriceps and bone, and in the E8002 group, an adhesion-preventing film was implanted between the quadriceps and femur after injury. Six weeks following injury, the restriction of knee flexion owing to fibrotic scarring had not worsened in the E8002 group but had worsened in the Adhesion group. The area of fibrotic scarring was smaller in the E8002 group than in the Adhesion group (p < 0.05). In addition, the numbers of fibroblasts (p < 0.05) and myofibroblasts (p < 0.01) in the fibrotic scar were lower in the E8002 group. Thus, E8002 reduces myofibroblast proliferation and fibrotic scar formation and improves the range of motion of the joint in a model of knee injury.

Adhesion-related readmissions after open and laparoscopic colorectal surgery in 16524 patients.

Colorectal surgery is associated with a high risk of adhesion formation and subsequent complications. Laparoscopic colorectal surgery reduces adhesion formation by 50%; however, the effect on adhesion-related complications is still unknown. This study aims to compare differences in incidence rates of adhesion-related readmissions after laparoscopic and open colorectal surgery. Population data from the Scottish National Health Service were used to identify patients who underwent colorectal surgery between June 2009 and June 2011. Readmissions were registered until December 2017 and categorized as being either directly or possibly related to adhesions, or as reoperations potentially complicated by adhesions. The primary outcome measure was the difference in incidence of directly adhesion-related readmissions between the open and laparoscopic cohort. Colorectal surgery was performed in 16524 patients; 4455 (27%) underwent laparoscopic surgery. Patients undergoing laparoscopic surgery were readmitted less frequently for directly adhesion-related complications, 2.4% (95% CI 2.0%-2.8%) versus 7.5% (95% CI 7.1%-7.9%) in the open cohort. Readmissions for possibly adhesion-related complications were less frequent in the laparoscopic cohort, 16.8% (95% CI 15.6%-18.0%) versus 21.7% (95% CI 20.9%-22.5%), as well as reoperations potentially complicated by adhesions, 9.7% (95% CI 8.9%-10.5%) versus 16.9% (95% CI 16.3%-17.5%). Overall, any adhesion-related readmissions occurred in over one in three patients after open colorectal surgery and one in four after laparoscopic colorectal surgery. Compared with open surgery, incidence rates of adhesion-related complications decrease but remain substantial after laparoscopic surgery.

Improving laparoscopic myomectomy outcomes

In the field of benign gynecology, laparoscopic myomectomy has clear advantages, although learning curve is longer. Our study aims to review the factors that improve the technique of laparoscopic myomectomies. For women with symptomatic fibroids who wish to maintain their fertility minimally invasive myomectomy is in most cases the best option. Therefore, laparoscopic approach is associated with shorter hospital stay, faster recovery, less postoperative pain, and reduced adhesion formation. Standardization of laparoscopic techniques could help to reduce the learning curve. The costs are higher compared with open myomectomy, but when we take into account the numerous advantages that laparoscopy has, including shorter operative time, less blood loss, shorter hospital stay and a more rapid recovery time, laparoscopy is more cost-efficient.

An Overview on Etiology, Diagnosis and Management of Ovarian Dermoied Cyst: Simple Review Article

The most common neoplastic ovarian lesions in teens are mature cystic teratomas (MCTs) or dermoid cysts. Little is known about the cause of dermoid cysts. Elevated levels of estrogen and progesterone have been suggested to stimulate the sebum components of these tumors, which may explain why MCTs grow after puberty and stop growing after menopause. MCTs are often asymptomatic and are randomly identified during examination or diagnostic imaging. MCTs show a special appearance during ultrasonography. Most studies suggest that most ovarian dermoid cysts can be successfully treated surgically using laparoscopic surgery. Reduced adhesion formation is one of the benefits of laparoscopic treatment for dermoid cysts. Studies also suggest that laparoscopy causes less blood loss. Less hospitalization and less postoperative pain. And there are fewer postoperative problems than the laparotomy approach. In this article, we will look at the etiology, diagnosis, and treatment of dermoid cysts in the ovary.

Management of Retained Products of Conception with Office Hysteroscopy

<h3>Study Objective</h3> The objective of this video is to demonstrate the feasibility of office hysteroscopy for the management of retained products of conception (POCs). <h3>Design</h3> N/A. <h3>Setting</h3> Two patients present weeks after early pregnancy loss with ongoing bleeding without fever or pain. Imaging is notable for heterogenous endometrial contents. After informed consent is obtained, office hysteroscopy is performed which visualizes retained POCs in the endometrial cavities. <h3>Patients or Participants</h3> Two patients with retained POCs are highlighted. <h3>Interventions</h3> A 5.5mm rigid hysteroscope with a 12-degree lens is used for office operative procedures so the working instrument is kept in the field of view. We routinely use vaginoscopy without a speculum or tenaculum to minimize patient discomfort. The first case has a smaller lesion which is taken down with blunt scissors in a targeted fashion. Given the large amount of products in the second case, a 5mm hysteroscopic morcellator facilitates efficient and directed removal, taking care to preserve normal endometrium. <h3>Measurements and Main Results</h3> Direct visualization of the endometrial cavities confirms complete removal of retained POCs. <h3>Conclusion</h3> Office hysteroscopy is a safe and effective approach for the management of retained POCs. It allows for targeted removal under visualization and reduces adhesion formation compared to traditional dilation and curettage. The vaginoscopic approach significantly reduces pain so no anesthesia is necessary, and patients are able to resume normal activities post-procedurally. It cost-effective compared to operating room procedures.

In Vivo Evaluation of a Pectin-Honey Hydrogel Coating on Polypropylene Mesh in a Rat Model of Acute Hernia

Investigations about ventral hernia repair are focused on improving the quality, resistance, and biocompatibility of mesh. This study compared plain polypropylene mesh with a pectin-honey hydrogel-coated polypropylene mesh in an acute hernia model in rats. Forty Wistar rats, randomly assigned to two groups, were submitted to laparotomy, and a 1 cm × 2 cm fascial defect was created, centered on the midline. Uncoated (group C) or coated mesh (group T) was inserted in an inlay fashion to repair the defect. After 30 days, the rats were euthanized, and the presence of adhesions to the mesh was macroscopically evaluated. Histology and measurement of COX-2 as tissue inflammation markers were used to assess fascia tissue healing. Grades of adhesion were not different between groups. Histological score and COX-2 expression were not significantly different between groups, except for the higher inflammatory response demonstrated in group T. The pectin-hydrogel coated mesh could not reduce adhesion formation compared to uncoated polypropylene mesh but improved peritoneal regeneration and tissue healing.

Reduction of adhesion formation after gynaecological adhesiolysis surgery with 4DryField PH – a retrospective, controlled study with second look laparoscopies

Adhesions are a common consequence of abdomino-pelvic surgery. Efficacy of available adhesion prevention agents is discussed controversially. Here, we used the adhesion barrier 4DryField PH: a powder, which is transformed into a barrier gel with saline solution. The study includes 40 consecutive patients with surgeries for adhesiolysis, endometriosis and other gynaecological pathologies and subsequent second look interventions. The intervention group (n = 17) received 4DryField PH gel while control patients (n = 23) did not receive any adhesion prevention. Severity and extent of adhesion formation were scored during both interventions using an established score. Direct comparison between first and second interventions showed that extent and severity of adhesions could be reduced significantly using 4DryField PH gel. In contrast, in the control group, extent was not reduced and severity was even significantly higher. Direct comparison of second look laparoscopies revealed that adhesion extent and severity were significantly lower in the 4DryField PH than in the control group. Impact Statement What is already known on this subject? Adhesion formation after gynaecologic surgeries is known to be frequent and highly problematic as it directly induces complications and additionally makes subsequent surgeries more difficult. The effectiveness of established adhesion barriers is not sufficient to tackle these problems adequately. What the results of this study add? This is the first controlled study using the relatively new adhesion barrier 4DryField PH. It yields a significant reduction of extent as well as severity of adhesions, while adhesiolysis surgery alone does not solve the problem. What the implications are of these findings for clinical practice and/or further research? Usage of 4DryField PH gel seems to be a good approach to solve the adhesion problem of gynaecologic surgery in general and the reformation problem of adhesiolysis surgery specifically. The results should be confirmed in a larger prospective randomised controlled trial.

Nanostructured Non-Newtonian Drug Delivery Barrier Prevents Postoperative Intrapericardial Adhesions.

With the increasing volume of cardiovascular surgeries and the rising adoption rate of new methodologies that serve as a bridge to cardiac transplantation and that require multiple surgical interventions, the formation of postoperative intrapericardial adhesions has become a challenging problem that limits future surgical procedures, causes serious complications, and increases medical costs. To prevent this pathology, we developed a nanotechnology-based self-healing drug delivery hydrogel barrier composed of silicate nanodisks and polyethylene glycol with the ability to coat the epicardial surface of the heart without friction and locally deliver dexamethasone, an anti-inflammatory drug. After the fabrication of the hydrogel, mechanical characterization and responses to shear, strain, and recovery were analyzed, confirming its shear-thinning and self-healing properties. This behavior allowed its facile injection (5.75 ± 0.15 to 22.01 ± 0.95 N) and subsequent mechanical recovery. The encapsulation of dexamethasone within the hydrogel system was confirmed by 1H NMR, and controlled release for 5 days was observed. In vitro, limited cellular adhesion to the hydrogel surface was achieved, and its anti-inflammatory properties were confirmed, as downregulation of ICAM-1 and VCAM-1 was observed in TNF-α activated endothelial cells. In vivo, 1 week after administration of the hydrogel to a rabbit model of intrapericardial injury, superior efficacy was observed when compared to a commercial adhesion barrier, as histological and immunohistochemical examination revealed reduced adhesion formation and minimal immune infiltration of CD3+ lymphocytes and CD68+ macrophages, as well as NF-κβ downregulation. We presented a novel nanostructured drug delivery hydrogel system with unique mechanical and biological properties that act synergistically to prevent cellular infiltration while providing local immunomodulation to protect the intrapericardial space after a surgical intervention.

Methylene blue reduces peritoneal adhesions in Syrian golden hamsters that undergo hepatopancreatic surgical procedures

Tissue ischemia, mechanical or thermal trauma, infection and foreign body reaction predispose to adhesion formation. Adhesion formation resembles an inflammatory process. Sometimes, they appear as a bridge to wound healing, however, in other times it may cause small bowel obstruction. Methylene blue is known to inhibit the generation of oxygen radicals. Therefore, it may be used as an antioxidant reducing adhesion formation. Hamsters are animals used in surgical experiments, including pancreatic and hepatic surgeries. &#x0D; Objective. To study the effectiveness of using methylene blue in hamsters that undergo hepatectomy or pancreatectomy. &#x0D; Methods. Syrian golden hamsters were divided in 6 groups: Partial pancreatectomy with splenectomy (PPS), PPS and MB (PPS-MB), Partial hepatectomy (PH), PH and MB (PH-MB), Sham operation (SO), and Sham operation and MB (SO-MB). MB was administered intraperitoneally before closing abdominal wall. Side effects were observed. Animals were sacrificed 10 days later and adhesions were quantified. &#x0D; Results. Adhesions were present in all animals (100%) of PH group and 3 of 5 (60%) of PPS group. In PH-MB and SO groups, 1 of 5 hamsters (20%) in each group showed adhesions. No adhesions were found in PPS-MB and SO-MB treated groups. None of animals showed loss of weight. &#x0D; Conclusion. This study suggests that methylene blue administration showed to be effective to prevent adhesion formation in hepatopancreatic surgical procedures.

Two natural materials found to reduce adhesion formation in a rat uterine horn model

Background/Aim: Post-operative pelvic adhesions cause various problems in patients, pose surgical difficulties to clinicians, and an increase in health costs. We compared the effectiveness of two natural materials, Trehalose (TRZ), Human Amnion Fluid (HAF), with oxidized regenerated cellulose (ORC) in terms of adhesion prevention after gynecological operations. Methods: In this controlled experimental study, twenty-four female Wistar Hannover rats were divided into four groups: Control, TRZ, HAF, and ORC. The control group received medication used for the surgical procedure only. 3% TRZ, cell-free HAF, and 1 cm2 ORC (interceed®) were laid on the tissue on the antimesenteric side of each uterine horn damaged with a 10-Watt bipolar cautery. Adhesions were scored 30 days after the first surgical procedure. Results: The extent, severity, degree, total adhesion, inflammation, and fibrosis scores of the control group were significantly higher than those of the TRZ and HAF groups (P<0.05 for each). There was no significant difference between the Control and ORC groups in terms of inflammation (P=0.055), but all other parameters were significantly higher in the control group compared to the ORC group (P<0.05). The TRZ group had lower total adhesion scores (P=0.019) and histopathological scores (P=0.015, P=0.001) than the ORC group. Conclusions: TRZ and HAF may be useful in preventing pelvic adhesions.

Prevention of adhesions post-abdominal surgery: Assessing the safety and efficacy of Chitogel with Deferiprone in a rat model.

Adhesions are often considered to be an inevitable consequence of abdominal and pelvic surgery, jeopardizing the medium and long-term success of these procedures. Numerous strategies have been tested to reduce adhesion formation, however, to date, no surgical or medical therapeutic approaches have been successful in its prevention. This study demonstrates the safety and efficacy of Chitogel with Deferiprone and/or antibacterial Gallium Protoporphyrin in different concentrations in preventing adhesion formation after abdominal surgery. 112 adult (8-10 week old) male Wistar albino rats were subjected to midline laparotomy and caecal abrasion, with 48 rats having an additional enterotomy and suturing. Kaolin (0.005g/ml) was applied to further accelerate adhesion formation. The abrasion model rats were randomized to receive saline, Chitogel, or Chitogel plus Deferiprone (5, 10 or 20 mM), together with Gallium Protoporphyrin (250μg/mL). The abrasion with enterotomy rats were randomised to receive saline, Chitogel or Chitogel with Deferiprone (1 or 5 mM). At day 21, rats were euthanised, and adhesions graded macroscopically and microscopically; the tensile strength of the repaired caecum was determined by an investigator blinded to the treatment groups. Chitogel with Deferiprone 5 mM significantly reduced adhesion formation (p<0.01) when pathologically assessed in a rat abrasion model. Chitogel with Deferiprone 5 mM and 1 mM also significantly reduced adhesions (p<0.05) after abrasion with enterotomy. Def-Chitogel 1mM treatment did not weaken the enterotomy site with treated sites having significantly better tensile strength compared to control saline treated enterotomy rats. Chitogel with Deferiprone 1 mM constitutes an effective preventative anti-adhesion barrier after abdominal surgery in a rat model. Moreover, this therapeutic combination of agents is safe and does not weaken the healing of the sutured enterotomy site.

Engineering a cell-hydrogel-fibre composite to mimic the structure and function of the tendon synovial sheath

The repair of tendon injuries is often compromised by post-operative peritendinous adhesions. Placing a physical barrier at the interface between the tendon and the surrounding tissue could potentially solve this problem by reducing adhesion formation. At present, no such system is available for routine use in clinical practice. Here, we propose the development of a bilayer membrane combining a nanofibrous poly(ε-caprolactone) (PCL) electrospun mesh with a layer of self-assembling peptide hydrogel (SAPH) laden with type-B synoviocytes. This bilayer membrane would act as an anti-adhesion system capable of restoring tendon lubrication, while assisting with synovial sheath regeneration. The PCL mesh showed adequate mechanical properties (Young's modulus=19±4 MPa, ultimate tensile stress=9.6±1.7 MPa, failure load=0.5±0.1 N), indicating that the membrane is easy to handle and capable to withstand the frictional forces generated on the tendon's surface during movement (~0.3 N). Morphological analysis confirmed the generation of a mesh with nanosized PCL fibres and small pores (< 3 μm), which prevented fibroblast infiltration to impede extrinsic healing but still allowing diffusion of nutrients and waste. Rheological tests showed that incorporation of SAPH layer allows good lubrication properties when the membrane is articulated against porcine tendon or hypodermis, suggesting that restoration of tendon gliding is possible upon implantation. Moreover, viability and metabolic activity tests indicated that the SAPH was conducive to rabbit synoviocyte growth and proliferation over 28 days of 3D culture, sustaining cell production of specific matrix components, particularly hyaluronic acid. Synoviocyte-laden peptide hydrogel promoted a sustained endogenous production of hyaluronic acid, providing an anti-friction layer that potentially restores the tendon gliding environment.

Evaluation of adhesion barrier types in a rat hepatectomy-induced adhesion model

BackgroundAdhesion formation after hepatectomy creates problems for repeat hepatectomy. This study aimed to compare the effectiveness of a spray (AdSpray) and sheet adhesion barrier (Seprafilm) in a rat hepatectomy-induced adhesion model.MethodsThirty male Sprague-Dawley rats underwent partial resection of the left lateral liver lobe. They were randomly assigned to control (n = 10), AdSpray (n = 10), and Seprafilm groups. Seven days after surgery, the animals were sacrificed, and adhesions at the hepatic resection surface were blindly evaluated.ResultsIn the control group, adhesions were formed in all 10 animals (100%), with a 69% adhesion extent (mean). In the AdSpray group, the incidence of adhesions (40%) and the adhesion extent (mean, 10%) were significantly lower than in the control group (incidence; p = 0.0147, adhesion extent; p = 0.0007). In the Seprafilm group, the incidence of adhesions was 70%. The adhesion extent of Seprafilm (mean, 30%) was significantly lower than in the control group (p = 0.0492). No significant differences were observed between the AdSpray and Seprafilm groups. As for histopathological examination, animals in the AdSpray group showed a similar healing profile to that of the control group without delayed healing and regeneration of mesothelial cells. In contrast, the Seprafilm group showed ongoing foreign body reaction to Seprafilm, and regeneration of mesothelial cells was immature at 7 days.ConclusionsBoth the spray-type gel and sheet adhesion barriers significantly reduced adhesion formation after hepatectomy. The spray-type adhesion barrier caused no adverse events and induced favorable healing. These adhesion barriers may be effective in hepatectomy. Further animal studies and clinical trials are required to determine their benefits in clinical use.

Prevention of intra-abdominal adhesions by a hyaluronic acid gel; an experimental study in rats.

In 80% to 90% of the patients intra-abdominal adhesions occur after abdominal surgery, which can cause small-bowel obstruction, chronic abdominal pain, female infertility and difficulty during reoperation. A novel crosslinked hyaluronic acid gel is evaluated regarding its anti-adhesive capacities in an ischemic button model in rats. 51 adult, male Wistar rats from a registered breeder, received eight ischemic buttons each and were treated with hyaluronic acid gel (HA, HyaRegen©), hyaluronic acid carboxymethylcellulose (HA-CMC, Seprafilm©) or no anti-adhesive barrier. After 14 days, the animals were sacrificed and adhesions were scored macroscopically. The number of buttons and organs involved in adhesions were recorded. Per animal, one button with adhesions and one without adhesions was explanted for qPCR analysis. Mann-Whitney U, Fisher's exact and Wilcoxon signed rank test were used for data analysis. A p-value of 0.05 was considered significant. Macroscopic evaluation of adhesion formation did not differ between the groups. The number of organs involved in adhesions in the HA gel group was significantly lower compared to HA-CMC (p = .041) and the control group (p = .012). A significantly, 1.36-fold higher clec10a (p = 0.25), 1.80-fold higher cd163 (p = 0.003) and 5.14-fold higher mmp1 expression (p = 0.028) was found in ischemic buttons with adhesions compared to buttons without adhesions. HA gel application reduces the number of organs involved in adhesions in an ischemic button model, but no overall reduction in adhesion formation was encountered. Macrophage subtype 2 polarization and high mmp1 expression are associated with adhesion formation. Further investigation is needed in the exact pathophysiologic process of adhesion formation and the role of macrophage polarization.

Increasing the level of cytoskeletal protein Flightless I reduces adhesion formation in a murine digital flexor tendon model

BackgroundSurgical repair of tendons is common, but function is often limited due to the formation of flexor tendon adhesions which reduce the mobility and use of the affected digit and hand. The severity of adhesion formation is dependent on numerous cellular processes many of which involve the actin cytoskeleton. Flightless I (Flii) is a highly conserved cytoskeletal protein, which has previously been identified as a potential target for improved healing of tendon injuries. Using human in vitro cell studies in conjunction with a murine model of partial laceration of the digital flexor tendon, we investigated the effect of modulating Flii levels on tenocyte function and formation of adhesions.MethodsHuman tenocyte proliferation and migration was determined using WST-1 and scratch wound assays following Flii knockdown by siRNA in vitro. Additionally, mice with normal and increased levels of Flii were subjected to a partial laceration of the digital flexor tendon in conjunction with a full tenotomy to immobilise the paw. Resulting adhesions were assessed using histology and immunohistochemistry for collagen I, III, TGF-β1and -β3ResultsFlii knockdown significantly reduced human tenocyte proliferation and migration in vitro. Increasing the expression of Flii significantly reduced digital tendon adhesion formation in vivo which was confirmed through significantly smaller adhesion scores based on collagen fibre orientation, thickness, proximity to other fibres and crimping. Reduced adhesion formation was accompanied with significantly decreased deposition of type I collagen and increased expression of TGF-β1 in vivo.ConclusionsThese findings suggest that increasing the level of Flii in an injured tendon may be beneficial for decreasing tendon adhesion formation.