Seprafilm (modified hyaluronic acid and carboxymethylcellulose) acts as a physical barrier

Bletilla striata Polysaccharide-Containing Carboxymethyl Cellulose Bilayer Structure Membrane for Prevention of Postoperative Adhesion and Achilles Tendon Repair

Postoperative tissue adhesion and poor tendon healing are major clinical problems associated with tendon surgery. To avoid postoperative adhesion and promote tendon healing, we developed and synthesized a membrane to wrap the surgical site after tendon suturing. The bilayer-structured porous membrane comprised an outer layer [1,4-butanediol diglycidyl ether cross-linked with carboxymethyl cellulose (CX)] and an inner layer [1,4-butanediol diglycidyl ether cross-linked with Bletilla striata polysaccharides and carboxymethyl cellulose (CXB)]. The morphology, chemical functional groups, and membrane structure were determined. In vitro experiments revealed that the CX/CXB membrane demonstrated good biosafety and biodegradability, promoted tenocyte proliferation and migration, and exhibited low cell attachment and anti-inflammatory effects. Furthermore, in in vivo animal study, the CX/CXB membrane effectively reduced postoperative tendon-peripheral tissue adhesion and improved tendon repair, downregulating inflammatory cytokines in the tendon tissue at the surgical site, which ultimately increased tendon strength by 54% after 4 weeks.

A novel tetra-PEG based hydrogel for prevention of esophageal stricture after ESD in a porcine model

Endoscopic submucosal dissection (ESD) is an accepted treatment for early esophageal cancer and precancerous lesions, but resection of a large mucosal area often leads to postoperative esophageal stricture. Biomaterials provide a new option for the treatment of post-ESD ulcers. In this study, we developed a well-defined ammonolysis-based tetra-armed poly (ethylene glycol) (Tetra-PEG) hydrogel and investigated its efficacy and related mechanisms for preventing esophageal ESD-induced stricture in a porcine model. In terms of material properties, Tetra-PEG hydrogel present great biocompatibility，great capability to retain moisture, strong tissue adhesion and high mechanical strength. Then, six domestic female pigs were randomly divided into PEG (n = 3) and control groups (n = 3). A 3/4 of the esophageal circumference ESD was performed in all pigs. In PEG group, Tetra-PEG hydrogel was easily delivered via endoscopy and adhered to the ulcer bed tightly. Compared to control group, Tetra-PEG hydrogel accelerated esophageal ulcer healing at an early stage with enhanced epithelium regeneration, milder inflammation and lesser fibrosis by regulating TGF-β/Smad2 signaling. Taken together, our findings reveal Tetra-PEG hydrogel is a promising and attractive candidate for preventing the formation of fibrotic stricture in the process of esophageal ESD-induced ulcer repair.

The preventive effect of omega-3 fish oil on the formation of peritoneal adhesions

<br><b>Introduction:</b> Postoperative peritoneal adhesions that form after abdominal surgery still continue to exist as an unresolved health problem.</br> <br><b>Aim:</b> The aim of the study is to examine whether omega-3 fish oil has a preventive effect on postoperative peritoneal adhesions.</br> <br><b>Material and methods:</b> Twenty-one female Wistar albino rats were separated into 3 groups (sham, control and experimental), each consisting of 7 rats. In the sham group, only laparotomy was performed. In both the control and experimental group rats, the right parietal peritoneum and cecum were traumatised to form petechiae. Following this procedure, the abdomen was irrigated with omega-3 fish oil in the experimental group. The rats were re-explored on the 14^th postoperative day and any adhesions were scored. Tissue samples and blood samples were taken for histopathological and biochemical analysis.</br> <br><b>Results:</b> None of the rats that were administered omega-3 fish oil developed macroscopic postoperative peritoneal adhesions (P = 0.005). The omega-3 fish oil formed an anti-adhesive lipid barrier on the injured tissue surfaces. Microscopic evaluation revealed diffuse inflammation with excessive connective tissue and fibroblastic activity in the control group rats, while foreign body reactions were common in the omega-3 rats. The mean amount of hydroxyproline in samples from injured tissues was significantly lower in the omega-3 rats than in the control rats (P = 0.004).</br> <br><b>Conclusion:</b> Intraperitoneal application of omega-3 fish oil prevents postoperative peritoneal adhesions by forming an anti-adhesive lipid barrier on injured tissue surfaces. However, further studies are needed to determine whether this adipose layer is permanent or will be resorbed over time.</br>.

Effects of Hyaluronic Acid/Collagen Resorbable Gel Use in Endoscopic Dacryocystorhinostomy

The purpose of this study was to investigate whether the use of hyaluronic acid/collagen resorbable gel (Regenwel®) has an inhibitory effect on rhinostomy obstruction during endoscopic dacryocystorhinostomy (Endo DCR). A total of 298 patients diagnosed with unilateral primary acquired nasolacrimal duct obstruction from May 2017 to June 2021 who underwent Endo DCR were enrolled. The patients were divided into the Regenwel group (152 patients) and the Control group (146 patients) that did not use Regenwel during surgery, and the medical records were compared and analyzed retrospectively. The mean age of the Regenwel group was 65.8 years, and that of the Control group was 63.2 years. Regarding anatomical success as the primary outcome, the Regenwel group had a higher success rate than the Control group (96.7% vs 86.3%, P = .012), and the functional success result confirmed that the Regenwel group had a higher success rate than the Control group (94.1% vs 84.3%, P = .024). Among secondary outcomes, granulation formation occurred less frequently in the Regenwel group than in the Control group (9.2% vs 32.2%, P < .001), and there was no statistically significant difference in postoperative bleeding between the 2 groups (0% vs 1.4%, P = .478). The Regenwel group had fewer infections after surgery than the Control group (5.3% vs 8.9%, P = .012) and required less frequent revision surgery (2.0% vs 15.8%, P < .001). In conclusion, Regenwel is a resorbable gel containing hyaluronic acid and collagen that is used during Endo DCR and is thought to contribute to the improvement of surgical success rate by preventing complications such as rhinostomy obstruction and bleeding after surgery.

Recent Advances of Biomedical Materials for Prevention of Post-ESD Esophageal Stricture

Esophageal stricture commonly occurs in patients that have suffered from endoscopic submucosal dissection (ESD), and it makes swallowing difficult for patients, significantly reducing their life qualities. So far, the prevention strategies applied in clinical practice for post-ESD esophageal stricture usually bring various inevitable complications, which drastically counteract their effectiveness. Nowadays, with the widespread investigation and application of biomedical materials, lots of novel approaches have been devised in terms of the prevention of esophageal stricture. Biomedical polymers and biomedical-derived materials are the most used biomedical materials to prevent esophageal stricture after ESD. Both of biomedical polymers and biomedical-derived materials possess great physicochemical properties such as biocompatibility and biodegradability. Moreover, some biomedical polymers can be used as scaffolds to promote cell growth, and biomedical-derived materials have biological functions similar to natural organisms, so they are important in tissue engineering. In this review, we have summarized the current approaches for preventing esophageal stricture and put emphasis on the discussion of the roles biomedical polymers and biomedical-derived materials acted in esophageal stricture prevention. Meanwhile, we proposed several potential methods that may be highly rational and feasible in esophageal stricture prevention based on other researches associated with biomedical materials. This review is expected to offer a significant inspiration from biomedical materials to explore more effective, safer, and more economical strategies to manage post-ESD esophageal stricture.

Polysaccharide-based films for the prevention of unwanted postoperative adhesions at biological interfaces

Postoperative adhesions protect, repair, and supply nutrients to injured tissues; however, such adhesions often remain permanent and complicate otherwise successful surgeries by tethering tissues together that are normally separated. An ideal adhesion barrier should not only effectively prevent unwanted adhesions but should be easy to use, however, those that are currently available have inconsistent efficacy and are difficult to handle or to apply. A robust hydrogel film composed of alginate and a photo-crosslinkable hyaluronic acid (HA) derivative (glycidyl methacrylate functionalized hyaluronic acid (GMHA)) represents a solution to this problem. A sacrificial porogen (urea) was used in the film manufacture process to impart macropores that yield films that are more malleable and tougher than equivalent films produced without the sacrificial porogen. The robust mechanical behavior of these templated alginate/GMHA films directly facilitated handling characteristics of the barrier film. In a rat peritoneal abrasion model for adhesion formation, the polysaccharide films successfully prevented adhesions with statistical equivalence to the leading anti-adhesion technology on the market, Seprafilm®. STATEMENT OF SIGNIFICANCE: Postoperative adhesions often remain permanent and complicate otherwise successful surgeries by tethering tissues together that are normally separated and pose potentially significant challenges to patients. Therefore, the generation of adhesion barriers that are easy to deploy during surgery and effectively prevent unwanted adhesions is a big challenge. In this study robust hydrogel films composed of alginate and a photo-crosslinkable hyaluronic acid (HA) derivative (glycidyl methacrylate functionalized HA, GMHA) were fabricated and investigated for their potential to act as a solution to this problem using a rat peritoneal abrasion model for adhesion formation. We observed the polysaccharide films successfully prevented adhesions with statistical equivalence to the leading anti-adhesion technology on the market, Seprafilm®, suggesting that such films represent a promising strategy for the prevention of postoperative adhesions.

Intrathoracic retention of insoluble hyaluronic acid and its absorption process in rats

BACKGROUND

Post-thoracotomy adhesions are frequent postoperative complications. It has been reported that insoluble hyaluronic acid may prevent adhesions.

MATERIALS AND METHODS

This study had two objectives: first, to determine the in vivo degradation and absorption process, as well as the intrathoracic retention, of solid insoluble hyaluronic acid membrane; and second, to elucidate the association between postoperative intrathoracic retention and the morphological changes of insoluble hyaluronic acid in 12 Wistar rats. Insoluble hyaluronic acid membranes were cut into 2.0 cm × 1.0 cm rectangles in a dry state. After weighing, the test membranes were soaked and washed with saline to be implanted after pericardiotomy via thoracotomy. At Days 4, 7, 10, 14, and 28 after implantation, the rats were euthanized, the chest was opened, and the condition and implantation site of the inserted test membrane were examined.

RESULTS

Although approximately 10 days were required for the test membrane to decrease to half in the thoracic cavity, the intrathoracic remnant decreased to a mean of ~2% just 4 days later.

CONCLUSION

This study clarified the time-dependent degradation process and remnants of insoluble hyaluronic acid in the thoracic cavity. A close relationship between the intrathoracic remnant of insoluble hyaluronic acid and its morphological change associated with degradation was demonstrated.

Clinical Results of Anti-adhesion Adjuvants after Endonasal Dacryocystorhinostomy

PURPOSE

Various absorbable anti-adhesion agents have been used to prevent postoperative synechia formation after endonasal surgery. The purpose of this study was to evaluate the anti-adhesion effects of HyFence and Mediclore after endonasal dacryocystorhinostomy (DCR) compared to a mixed solution of hyaluronic acid and sodium carboxymethylcellulose (Guardix-Sol).

METHODS

In this retrospective study, endonasal DCR and silicone tube intubation were performed on 198 eyes of 151 patients. Three different anti-adhesion adjuvants were applied to the osteotomy site in the nasal cavity after standard endonasal DCR procedures. The subjects were classified into three respective groups: group A (71 eyes, Guardix-Sol 1.5 g), group B (89 eyes, HyFence 1.5 mL), and group C (38 eyes, Mediclore 1 cc). The three groups were evaluated by asking patients about subjective symptoms and by performing lacrimal irrigation tests and endoscopic examinations.

RESULTS

There were no statistically significant differences in age, sex, timing of tube removal, or follow-up period among the three groups. There were no statistically significant differences in success rates among the three groups (p = 0.990, 91.5% [65 / 71], 92.1% [82 / 89], and 92.1% [35 / 38], respectively).

CONCLUSIONS

HyFence and Mediclore are safe and effective adjunctive modalities following endonasal DCR compared to Guardix-Sol. Therefore, these agents can be considered good alternatives to Guardix-Sol to increase the success rate of endonasal DCR in treating patients with poor prognosis.

Assessment of the subcutaneous degradation process of insoluble hyaluronic acid in rats

Insoluble hyaluronic acid (IHA) may prevent adhesions by forming a physical barrier during the period when postoperative adhesions form. This study was performed to verify the changes that a solid IHA membrane undergoes as it is degraded in vivo, and to ascertain the swelling rate of IHA required for it to function as a physical barrier during the postoperative adhesion formation period. Nine female WI rats weighing 300-400 g were used. Discs 8 mm in diameter were cut out of dry IHA membranes made of IHA with a swelling rate (wet weight/dry weight) of either 2.47 (high-swelling IHA) or 1.94 (low-swelling IHA). They were placed in saline to swell and then washed with saline before subcutaneous implantation in four pockets in each rat. The high-swelling IHA started to degrade more rapidly than the low-swelling IHA. There was no evidence of degradation of the low-swelling IHA until day 7, but once it had started, the speed of degradation tended to be similar to that of the high-swelling IHA. The present results showed that, when IHA is implanted subcutaneously in rats, it is degraded over time in a phased process. The swelling rate required for the use of IHA as a postoperative adhesion barrier was also suggested.

Deployment of carboxymethyl cellulose sheets to prevent esophageal stricture after full circumferential endoscopic submucosal dissection: A porcine model

BACKGROUND AND AIM

Esophageal stricture is a serious adverse event secondary to extensive endoscopic submucosal dissection (ESD). The present study aimed to investigate the efficacy of carboxymethyl cellulose (CMC) sheets for the prevention of esophageal stricture after full circumferential ESD in an animal model.

METHODS

Fourteen porcine models were randomized into a control group (n = 7) and a CMC group (n = 7). Five-centimeter-long circumferential esophageal ESD was carried out at a distance of 40 to 45 cm from the incisors in all models. In the CMC group, CMC sheets were placed over the mucosal defect completely after ESD, whereas the control group underwent routine ESD only. Endoscopic examination was conducted after the first and second week post-ESD. Esophageal specimens were harvested during post-mortem and were evaluated for macroscopic and histological appearance. Blood serum levels of four pro-inflammatory or profibrotic cytokines were measured quantitatively.

RESULTS

The CMC group had better food tolerability during the second week post-ESD. The CMC group showed a significantly lower esophageal mucosal stricture rate compared to the control group. Histological assessments showed less fibrosis in the submucosal layer, milder damage to the muscularis propria, and enhanced re-epithelization in the CMC group. Serum transforming growth factor beta 1 levels were significantly lower in the CMC group post-ESD.

CONCLUSION

Deployment of CMC sheets on the mucosal defect appears to be a promising method for preventing esophageal strictures after extensive ESD.

Antiadhesive Effect of the Mixed Solution of Sodium Hyaluronate and Sodium Carboxymethylcellulose after Endoscopic Sinus Surgery

Background

We evaluated the clinical efficacy and safety of the mixed solution of sodium hyaluronate and sodium carboxymethylcellulose (HA-CMC) for prevention of adhesion after endoscopic sinus surgery.

Methods

Preoperative computed tomography (CT) scans were graded. At the completion of surgery, HA-CMC was applied to Merocel and repeatedly applied after the removal of Merocel. As a control, normal saline was applied. Endoscopic examination was performed postoperatively and grading was done.

Results

The rate of adhesion was the highest at 2 weeks postoperatively and was significantly lower in the HA-CMC–treated group than the control on all postoperative days. The grouping of cases by CT scores at 2 weeks postoperatively showed lower adhesion formation with the HA-CMC treatment than the control. The safety profile of the patients was normal at 4 weeks postoperatively.

Conclusion

HA-CMC is an efficacious and safe material in decreasing the incidence of adhesion after endoscopic sinus surgery.

Effect of sodium hyaluronate/carboxymethyl cellulose (Guardix-sol) on retear rate and postoperative stiffness in arthroscopic rotator cuff repair patients: A prospective cohort study

PURPOSE

Hyaluronate-based anti-adhesive agents are expected to enhance rotator cuff healing; however, their effect on the incidence and extent of postoperative complications such as stiffness and retears has not been investigated.

METHODS

From July 2012 to February 2013, 80 patients undergoing arthroscopic rotator cuff repair surgery were prospectively enrolled. Forty patients were assigned to the control group, while the other 40 were assigned to the injection group and received a Guardix-sol injection immediately after surgery. Passive range of motion, pain visual analog scale, and functional score were assessed at 8 weeks, 6 months, and 24 months postoperatively. Gliding motion between the deltoid muscle and the greater tuberosity of the proximal humerus was evaluated using ultrasonography at 2 and 8 weeks postoperatively, and tendon integrity was evaluated using magnetic resonance imaging at 6 months postoperatively.

RESULTS

We found no significant difference between the groups regarding gliding motion at 2 weeks postoperatively. However, at 8 weeks, the incidence of poor gliding motion was 2.5% and 15% for the injected patients and control group, respectively, which was statistically significant. At 6 months after surgery, the retear rate between the two groups was not statistically significant. We found no statistically significant difference between the two groups regarding retear rate and clinical score throughout the follow-up period. We noted no complications related to the use of Guardix-sol.

CONCLUSIONS

Patients who received the Guardix-sol injection showed improved gliding motion between the deltoid muscle and the greater tuberosity in the early postoperative period.

Effects of Membrane Adhesion Barriers on Wound Healing Reaction after Glaucoma Filtration Surgery: A Comparative Study with Interceed and Seprafilm

Purpose

To evaluate and compare the effectiveness of two adhesion barriers, Interceed and Seprafilm, on wound healing reaction after glaucoma filtration surgery.

Materials and Methods

Full-thickness filtration surgery was carried out on three groups, each containing four rabbits. Interceed and Seprafilm prepared in 3×4 mm dimensions was put on and around scleral opening in Groups 1 and 2, respectively. All groups received tobramycin and dexamethasone drops tid for 14 days. Intraocular pressure (IOP), anterior chamber depth, and bleb appearance were checked on the first, third, seventh, and 14th days. The rabbits were killed on the 14th day and the trabeculectomy area with overlying conjunctiva was excised. The samples were fixed with 10% formalin, buried in paraffin, and stained with hematoxylin and eosin. The surgical site and surrounding subconjunctival area were evaluated histopathologically for cell counts (fibroblast, lymphocyte, eosinophil, and macrophage), presence of edema and foreign body reaction, and potency of the fistula tract.

Results

Mean IOP at the first and third day examinations was significantly different between groups, but there was no statistically significant difference among the groups with respect to IOP, anterior chamber depth, or bleb appearance at the seventh and 14th days. The groups were similar with respect to number of fibroblasts, eosinophils, and neutrophils. Number of macrophages was significantly increased in Groups 1 and 2 and number of vessels was significantly decreased in Group 1.

Conclusions

Neither of these two adhesion-preventing substances seems to suppress wound healing reaction after glaucoma filtration surgery. However, a diminished wound healing reaction was expected with a decreased number of vessels, such as in Group 1. Increased number of macrophages in both groups may result in a decreased level of some inflammatory mediators.

Anti-adhesive effect of solid mixture of sodium hyaluronate/carboxymethylcellulose in murine nasal cavities

The purpose of the study was to evaluate the effect of a solid mixture of sodium hyaluronate and carboxymethylcellulose (S-HA/CMC) for the prevention of adhesions after iatrogenic mucosal injury in murine nasal cavities. We introduced iatrogenic adhesions into the bilateral nasal cavities of 20 male Sprague-Dawley rats. S-HA/CMC was applied to the left nasal cavity, while no packing was placed in the right nasal cavity as a control. At 1, 2, and 4 weeks post-procedure, we examined the number of adhesions, the ratio of the longest cross-sectional length of adhesion to septal cartilage length (RAC), and the degree of fibrosis. S-HA/CMC significantly reduced the number of adhesions when compared to the control group in total (p = 0.031), but not at each individual time point. The S-HA/CMC group showed significantly shorter RAC than the control group in total (p = 0.044), but not at each individual time point. The total fibrosis score was less severe in the S-HA/CMC group than in the control group (p < 0.001), with a significant difference between the two groups at the second week (p = 0.001). Therefore, in an animal model, S-HA/CMC can prevent post-injury mucosal adhesions suggesting a potential for clinical applications in endoscopic sinus surgery. Further clinical trials are needed to determine the safety and efficacy of S-HA/CMC as nasal packing after endoscopic sinus surgery.

Ghrelin ameliorates adhesions in a postsurgical mouse model

BACKGROUND

Peritoneal adhesion formation is a well-recognized consequence of abdominal and pelvic surgery, causing infertility, chronic pelvic pain, and intestinal obstruction. We hypothesized that ghrelin, a 28-amino acid peptide predominantly found in the stomach, plays an important role in preventing postoperative surgical adhesions. The purpose of this study was to develop a new surgical peritoneal adhesion model to define the role that ghrelin plays in wound healing and adhesion formation.

MATERIALS AND METHODS

C57BL/6 wild-type mice (n = 40) and growth hormone secretagogue receptor-knockout (GHSR KO) mice (n = 20) underwent a midline laparotomy to establish a peritoneal adhesion model characterized by the combination of two different techniques: ischemic peritoneal buttons and cecal multiple abrasion. All mice received intraperitoneal injections with ghrelin (0.16 mg/kg) or saline twice daily for 20 d after surgery. Peritoneal ischemic buttons were harvested to determine protein expression of collagen (Masson trichrome, picrosirius red stain, and Western blot).

RESULTS

The novel mouse model demonstrated consistent and easily reproducible formation of intra-abdominal adhesions. Ghrelin administration significantly reduced postoperative adhesion formation (P < 0.001) in wild-type mice. The antifibrotic effect of ghrelin in wild-type mice was confirmed by measuring collagen I protein levels via Western blot analysis. The anti-adhesion effect of ghrelin seen in wild-type mice was not detected in GHSR KO mice demonstrating that this effect is mediated by the GHSR-1a receptor.

CONCLUSIONS

Ghrelin administration may improve surgical outcome by reducing peritoneal adhesion formation and fibrotic response in a mouse model.

Application of free temporoparietal fascial flap for recurrent neural adhesion of superficial radial nerve--A case report

Because of its anatomical location, the superficial radial nerve is vulnerable to trauma as well as injury during various surgical procedures. Once the nerve adheres to surrounding scar tissue, radiating pain often occurs due to nerve traction caused by loss of smooth gliding. Since it has been reported that the success rate with neurolysis only is lower, additional preventive procedures for recurrent neural readhesion are recommended. In the current report, we describe our experience performing neurolysis followed by nerve coverage using a free temporoparietal fascial flap for recurrent neural adhesion of the superficial radial nerve. A 45-year-old male complained of motion pain of the left wrist and thumb joints caused by recurrent neural adhesion of the superficial radial nerve after a chain saw trauma and following multiple reconstructive procedures. The radiating pain completely disappeared after neurolysis performed by a previous surgeon; however, it recurred 4 weeks later. Four months after the previous neurolysis the patient underwent external neurolysis and covering of the nerve with a free temporoparietal fascial flap to prevent neural readhesion because local soft tissue could not be used due to the massive scar tissues on the forearm. One year after the secondary neurolysis, the symptoms of radiating pain during wrist and thumb motion were drastically improved. A free adipofascial flap such as a temporoparietal flap may be an option for prevention of neural readhesion after neurolysis of the superficial radial nerve in cases where a local flap cannot be used on the forearm.

A multicentre, randomised, controlled trial to assess the safety, ease of use, and reliability of hyaluronic acid/carboxymethylcellulose powder adhesion barrier versus no barrier in colorectal laparoscopic surgery

Background

Intra-peritoneal adhesions are frequent following abdominal surgery and are the most common cause of small bowel obstructions. A hyaluronic acid/carboxymethylcellulose (HA/CMC) film adhesion barrier has been shown to reduce adhesion formation in abdominal surgery. An HA/CMC powder formulation was developed for application during laparoscopic procedures.

Methods

This was an exploratory, prospective, randomised, single-blind, parallel-group, Phase IIIb, multicentre study conducted at 15 hospitals in France to assess the safety of HA/CMC powder versus no adhesion barrier following laparoscopic colorectal surgery. Subjects ≥18 years of age who were scheduled for colorectal laparoscopy (Mangram contamination class I‒III) within 8 weeks of selection were eligible, regardless of aetiology. Participants were randomised 1:1 to the HA/CMC powder or no adhesion barrier group using a centralised randomisation list. Patients assigned to HA/CMC powder received a single application of 1 to 10 g on adhesion-prone areas. In the no adhesion barrier group, no adhesion barrier or placebo was applied. The primary safety assessments were the incidence of adverse events, serious adverse events, and surgical site infections (SSIs) for 30 days following surgery. Between-group comparisons were made using Fisher’s exact test.

Results

Of those randomised to the HA/CMC powder (n = 105) or no adhesion barrier (n = 104) groups, one patient in each group discontinued prior to the study end (one death in each group). Adverse events were more frequent in the HA/CMC powder group versus the no adhesion barrier group (63% vs. 39%; P <0.001), as were serious adverse events (28% vs. 11%; P <0.001). There were no statistically significant differences between the HA/CMC powder group and the no adhesion barrier group in SSIs (21% vs. 14%; P = 0.216) and serious SSIs (12% vs. 9%; P = 0.38), or in the most frequent serious SSIs of pelvic abscess (5% and 2%; significance not tested), anastomotic fistula (3% and 4%), and peritonitis (2% and 3%).

Conclusions

This exploratory study found significantly higher rates of adverse events and serious adverse events in the HA/CMC powder group compared with the no adhesion barrier group in laparoscopic colorectal resection.

Trial registration

ClinicalTrials.gov NCT00813397. Registered 19 December 2008.

Modified novel technique for improving the success rate of applying seprafilm by using laparoscopy

STUDY OBJECTIVE

To describe a modified surgical procedure for applying the adhesion barrier Seprafilm laparoscopically.

DESIGN

Retrospective analysis with videos and illustrations showing laparoscopic application of Seprafilm.

SETTING

University hospital.

PATIENTS

Women undergoing fertility-sparing laparoscopic surgery (myomectomy, endometriotic ovarian cyst or dermoid cyst enucleation, and tuboplasty) via a modified technique.

INTERVENTION

Two layers of Seprafilm with plastic covering were rolled together and delivered through a 10-mm trocar, and an irrigation tube was used to moisten the Seprafilm and cover the irregular postoperative rough surface of the organ. After application of Seprafilm, the patient was placed in a reverse Trendelenburg position to check whether the Seprafilm remained in situ on the target surgical surface to act as a physical barrier to adhesion development.

MEASUREMENTS AND MAIN RESULTS

After changing the patient's position, illustrations and videos showed that the Seprafilm remained on the postoperative surgical surface, creating a site-specific physical barrier. On day 4 after myomectomy, second-look laparoscopy in 2 patients showed that the Seprafilm had become gel-like and remained between the intestine and posterior rough surface of the uterus. There were no systemic second-look laparoscopic data.

CONCLUSION

It is feasible and easier to apply Seprafilm adhesion barrier laparoscopically using the modified technique. Further studies are warranted to prove its efficacy after such use.

A Randomized, Multi-Center, Single Blind, Active-Controlled, Matched Pairs Clinical Study to Evaluate Prevention of Adhesion Formation and Safety of HyFence in Patients After Endoscopic Sinus Surgery

Objectives

Recurrent mucosal disease and anatomic obstruction are commonly cited causes of failed endoscopic sinus surgery (ESS). Hyaluronic acid (HA) has been reported to reduce scarring and to promote wound healing in sinonasal surgery. HyFence is HA stabilized by 1, 4-butandiol diglycidyl ether, which makes it less-water-soluble and highly viscoelastic. The purpose of this study is to examine the anti-adhesion effect of HyFence after ESS compared to that of HA-CMC (Guardix-Sol).

Methods

Seventy-four patients with chronic rhinosinusitis who underwent ESS were included in the study. After the ESS procedure, Merocel was placed in the ethmoidectomized areas of the both sides. Five milliliters of Guardix-Sol was then applied to the Merocel of one side and HyFence LV was applied to the other side. The effect of the agents was evaluated at one, two, and four weeks after surgery by endoscopic examination. The severity of adhesion, edema, infection and complications were evaluated.

Results

There was no significant difference in the incidence of postoperative adhesion between the HyFence group and the Guardix-Sol group (P>0.05). Mean postoperative grades of edema and infection showed no significant difference between groups (P>0.05). There was no significant postoperative complications associated with either anti-adhesion agent (P>0.05).

Conclusion

HyFence has equivalent anti-adhesion effect compared to Guardix-Sol following ESS.

Prevention of intra-abdominal adhesion by bi-layer electrospun membrane

The aim of this study was to compare the anti-adhesion efficacy of a bi-layer electrospun fibrous membrane consisting of hyaluronic acid-loaded poly(ε-caprolactone) (PCL) fibrous membrane as the inner layer and PCL fibrous membrane as the outer layer with a single-layer PCL electrospun fibrous membrane in a rat cecum abrasion model. The rat model utilized a cecal abrasion and abdominal wall insult surgical protocol. The bi-layer and PCL membranes were applied between the cecum and the abdominal wall, respectively. Control animals did not receive any treatment. After postoperative day 14, a visual semiquantitative grading scale was used to grade the extent of adhesion. Histological analysis was performed to reveal the features of adhesion tissues. Bi-layer membrane treated animals showed significantly lower adhesion scores than control animals (p < 0.05) and a lower adhesion score compared with the PCL membrane. Histological analysis of the bi-layer membrane treated rat rarely demonstrated tissue adhesion while that of the PCL membrane treated rat and control rat showed loose and dense adhesion tissues, respectively. Bi-layer membrane can efficiently prevent adhesion formation in abdominal cavity and showed a significantly decreased adhesion tissue formation compared with the control.

Efficacy of Seprafilm(®) graft with adhesiolysis in experimentally induced lid adhesion in rabbits

AIM

To evaluate the efficacy of Seprafilm(®) transplantation following adhesiolysis for preventing postoperative readhesion and improving surgical outcomes.

METHODS

Primary blepharoplasty was carried out on both eyelids of 18 albino rabbits. After 2 weeks, a new skin incision was made, and adhesiolysis was performed on both eyelids. The rabbits were categorized into two groups, one with adhesiolysis alone in the left eyelid (control group), and the other with adhesiolysis with a Seprafilm(®) graft in the right eyelid (Seprafilm(®) group). The degrees of inflammation and fibrosis were examined with hematoxylin-eosin (HE) and Masson's trichrome stains. Expression of α-smooth muscle actin (α-SMA) was also immunohistochemically examined.

RESULTS

Eyelid examination immediately after the operation revealed mild swelling and hemorrhage in both groups, but these symptoms resolved after 1 week-2 weeks, and eyelid shape had recovered completely in both groups. Microscopic assessments demonstrated that the Seprafilm(®) group showed less inflammation and fibrosis than the control group. The Seprafilm(®) group also exhibited fewer α-SMA-positive cells than the control group.

CONCLUSION

Based on these findings, we conclude that Seprafilm(®) graft with adhesiolysis is an effective method for preventing postoperative readhesions after eyelid surgery.

The effect of postoperative hyperbaric oxygen treatment on intra-abdominal adhesions in rats

Abdominal adhesions, whether caused by peritoneal trauma, radiation, infection, or a congenital condition, are associated with a wide range of complications. These complications include chronic abdominal or pelvic pain, infertility, and adhesive small bowel obstruction. Such adhesions render re-operation difficult, with attendant risks of inadvertent enterostomy and increased operation time. The purpose of this study was to investigate the potential of hyperbaric oxygen (HBO) therapy in the prevention of abdominal adhesions in an experimental animal study. A laparotomy was performed on Wistar rats to induce the formation of adhesions on the cecum and the intra-abdominal area (1 × 2 cm). A superficial layer of the underlying muscle from the right abdominal wall was also shaved and prepared for aseptic surgery. The rats were divided into four groups according to the duration of HBO therapy; five additional groups were designated according to the conditions of HBO therapy. When the rats were evaluated according to adhesion area and grade, a statistically significant difference was observed between the control and HBO treatment groups (p < 0.005). Results from this study suggest that HBO treatment could reduce adhesion formation; and further suggest that HBO therapy may have therapeutic potential in the treatment of postoperative peritoneal adhesion.

Remote efficacy for two different forms of hyaluronate-based adhesion barriers

BACKGROUND

Chemically modified sodium hyaluronate and carboxymethylcellulose (HA/CMC) membrane clinically reduces adhesion formation following surgery but was not designed for laparoscopic use. HA/CMC powder of identical chemical composition has been developed to allow for application laparoscopically. We compared the adhesion reduction efficacy of HA/CMC powder and film when applied directly to or remote from sites of surgical trauma. We also investigated the effect of the powder on wound healing.

MATERIALS AND METHODS

Two animal models of adhesion formation were used to evaluate efficacy: a rat peritoneal sidewall defect model and a rabbit cecal abrasion/sidewall defect model. The products were applied directly to the defect or the contralateral sidewall. Adhesions were examined seven days after surgery. In a separate study, the effect of the powder on healing was evaluated at 5, 7, and 28 days using a rat incisional wound strength model.

RESULTS

HA/CMC powder and film, when applied directly to the peritoneal defect, significantly reduced adhesions relative to the untreated control in both models. Remote applications of HA/CMC powder also reduced adhesions. In contrast, remote applications of HA/CMC film had no effect. HA/CMC powder did not significantly alter incisional wound strength at any of the timepoints tested.

CONCLUSION

In our preclinical models, HA/CMC powder had similar adhesion reduction efficacy to HA/CMC film when applied directly to sites of trauma. In addition, HA/CMC powder reduced adhesions remote from the application site. Importantly, HA/CMC powder did not impair incisional wound healing. On the basis of these results, future investigation of HA/CMC powder is warranted.

Clinical effect of a mixed solution of sodium hyaluronate and sodium carboxymethylcellulose during the transconjunctival approach for orbital wall reconstruction

This study aimed to evaluate the anti-adhesive effect of a mixed solution of sodium hyaluronate and sodium carboxymethylcellulose (HACMC, Guardix-sol®) during the transconjunctival approach to orbital wall reconstruction. Eighty-seven patients who underwent orbital wall reconstruction by the transconjunctival approach were enrolled in this prospective study. We applied HACMC between the orbicularis oculi muscle and the orbital septum after surgery in 47 patients and did not use it in 40 patients. Lower lid retraction and marginal reflex distance 2 (MRD₂) were measured to analyze the degree of postoperative adhesion at 1 week and 1, 3, and 6 months. The degree of MRD₂ showed clinically significant differences at postoperative 1 week and 1 month between the HACMC and control groups (p<0.05). Lower lid ectropion developed in two patients (5.0%) in the control group but did not occur in the HACMC group. In orbital wall reconstruction by the transconjunctival approach, the HACMC mixture solution is effective for preventing adhesion and lower lid ectropion during the early postoperative period.

Adhesion prevention in patients with multiple cesarean deliveries

Adhesion formation is a well-known complication of abdominal surgery. Although one third of all deliveries in the United States are by cesarean delivery (CD), little is known about adhesions in the obstetric setting. Various surgical techniques for reducing adhesion formation following CD have been investigated. The relative benefits of peritoneal closure and single-layer uterine closure are areas of continued research and debate. Adhesion prevention products are also becoming more commonplace in gynecologic surgery. Two membrane/adhesion barriers have been approved in the United States. A barrier consisting of oxidized regenerated cellulose (Interceed absorbable adhesion barrier) has been shown to reduce adhesions during microsurgery. Its use may be limited following CD because complete hemostasis is crucial to its efficacy. Seprafilm adhesion barrier, composed of hyaluronic acid and carboxymethylcellulose, is approved for use in abdominal or pelvic laparotomy. Preliminary data suggest that it may be effective for reducing adhesions following CD. This article discusses what is currently known about adhesion prevention in the obstetric population and highlights the paucity of level I evidence available to clinicians in this setting.

Effect of hyaluronic acid-carboxymethylcellulose solution on perineural scar formation after sciatic nerve repair in rats

Background

Scar tissue formation is the major cause of failure in peripheral nerve surgery. Use of a hyaluronic acid-carboxymethylcellulose (HA-CMC) membrane (Seprafilm) as a solid anti-adhesion barrier agent is one of the therapeutic approaches to reduce postoperative scar tissue formation. However, a solid membrane may not be suitable for repair of a weak peripheral nerve site. This study examined the effect of HA-CMC solution on perineural scar formation after peripheral nerve repair in rats.

Methods

The sciatic nerves of 40 rats were transected and then immediately repaired using 10-0 nylon. The nerves were divided randomly into two groups. Saline and HA-CMC solution were applied topically to the nerve repair sites in the control and experimental groups, respectively. Reoperation was performed at 3, 6, 9, and 12 weeks to assess scar tissue formation. The assessment included the quality of wound healing, presence of perinueral adhesion, cellular components of the scar tissue, thickness of the scar tissue and histomorphological organization of the repair site.

Results

Topical application of the HA-CMC solution significantly decreased the macroscopic nerve adherence score and the numbers of the cellular components such as fibroblasts and inflammatory cells (p < 0.05, Mann-Whitney U-test). The scar tissue formation index was significantly lower in the experimental group at 12 weeks than that in the control group (p < 0.05, Mann-Whitney U-test). The grading scores of the histomorphological axonal organization at the repair site were significantly higher in the experimental group than those in the control group at 12 weeks (p < 0.05, Mann-Whitney U-test). No evidence of wound dehiscence or inflammatory reactions against the HA-CMC solution was noted.

Conclusions

Topical application of a HA-CMC solution is effective in reducing the perineural scar formation and adhesion after sciatic nerve repair in rats, and is effective in promoting peripheral nerve regeneration at the repair site.

Gynecologic use of Sepraspray Adhesion Barrier for reduction of adhesion development after laparoscopic myomectomy: a pilot study

OBJECTIVE

To assess the safety and efficacy of Sepraspray Adhesion Barrier (a modified hyaluronic acid and carboxymethylcellulose powder) after laparoscopic surgery, in view of both the high efficacy of Seprafilm Adhesion Barrier in reducing postoperative adhesions after open surgical procedures and the difficulty with laparoscopic delivery.

DESIGN

Multicenter, randomized, reviewer-blinded trial.

SETTING

Reproductive endocrinology and infertility clinics.

PATIENT(S)

Women undergoing laparoscopic myomectomy for indications including infertility.

INTERVENTION(S)

Randomization to treatment with (n = 21) or without (n = 20) Sepraspray Adhesion Barrier.

MAIN OUTCOME MEASURE(S)

Postoperative adhesions development was assessed at early second-look laparoscopy. Adhesions were scored using the modified American Fertility Society scoring system.

RESULT(S)

Surgical procedure duration length was 99 versus 102 minutes in the control versus Sepraspray Adhesion Barrier groups, respectively, with the median number of fibroids removed being two in each group and corresponding fibroid weights of 134 ± 103 versus 113 ± 161 g, respectively. Adhesions scores increased in both the control and Sepraspray Adhesion Barrier groups, with larger although nonstatistically significant increases noted in control subjects when evaluating for the anterior uterus, the posterior uterus, and the entire uterus.

CONCLUSION(S)

Laparoscopic application of Sepraspray Adhesion Barrier after myomectomy in this pilot study was associated with a trend toward a reduction in postoperative adhesion development, as well as an encouraging safety profile. Further evaluation is warranted.

CLINICAL TRIAL NUMBER

Sepraspray Adhesion Barrier #NCT00624930.

Adhesion prevention and reduction: current status and future recommendations of a multinational interdisciplinary consensus conference

Adhesions can be found after virtually every abdominopelvic operation performed through standard laparotomy as well as by laparoscopic approaches. Adhesions can be completely asymptomatic or can cause significant morbidity and mortality including strangulation, obstruction, and necrosis of bowel loops and/or infertility and organ injury during repeat abdominal surgery. Perhaps because of the multifactorial nature of adhesion development, prevention has been very limited. Three anti-adhesion products are commercially available, none of which has been universally accepted as a panacea. Part of the obstacles with adhesion management is the lack of an objective clinically relevant classification to allow their study. Because a single band can cause a life-threatening bowel obstruction, whereas extensive dense intra-abdominal adhesions may be asymptomatic, neither the mere presence or absence of adhesions nor their extent if present is totally adequate endpoints. Adhesions are a major health care burden, and their reduction is a significant unmet need in surgical therapeutics facing all surgeons. Of all the parameters assessing adhesions currently available, the authors believe that adhesion incidence (presence or absence) is the most relevant endpoint with a direct clinical implication. The authors endorse the development of a validated, clinically relevant scale to assess intra-abdominal adhesions. Given the present limitation of objective assessment of adhesions and prediction of their clinical effect, the authors also advocate, when appropriate, the use of one of the Food and Drug Administration-approved adhesion barriers. Further research is required to develop safe and effective anti-adhesion methods as well as better assessment tools for their efficacy.

The effects of applying adhesion prevention gel on the range of motion and pain after TKA

A mixed solution of sodium hyaluronate and sodium carboxymethylcellulose (HA/CMC) has been shown to be effective for decreasing postoperative adhesions in various kinds of surgeries. We evaluated the clinical efficacy and safety of HA/CMC gel on the early postoperative range of motion and pain relief after total knee arthroplasty (TKA). Thirty one patients who underwent bilateral TKA as a single-stage procedure for primary osteoarthritis were included in the study. At the completion of surgery, among both knees, the HA/CMC gel was applied to one knee (the HA/CMC group) and HA/CMC gel was not applied to the other knee (the control group). The primary outcome measure was the early assessment of range of motion and the secondary outcome measures were the VAS pain scores and the number of complications in each group. Periarticular application of HA/CMC gel was safe without causing any wound problems or infection. However, local application of HA/CMC gel neither increased the range of motion nor reduced the pain during the early postoperative period of TKA.

Efficacy of antiadhesion barrier solution on periimplant capsule formation in a white rat model

Antiadhesive barrier solution (AABS) has been proven to prevent intraabdominal adhesion by reducing inflammation and fibrosis formation. Because this mechanism can also be applied to capsule formation after the breast implant insertion, we hypothesize that AABS can reduce capsular contraction and evaluate the efficacy of AABS on perisilastic implant capsule formation after submuscular insertion. A silicone block was inserted beneath the panniculus carnosus muscle in 10 rats. The experiment group received 0.1 mL of AABS (Guardix, Hanmi Medical Co.) instilled into the pocket, whereas the control group received 0.1 mL saline solution. Periimplant capsules were excised after 4 weeks and were evaluated for inflammatory cell count, capsular thickness, collagen pattern, and amount of myofibroblast. The inflammatory cell count and the capsular thickness were lower in the experiment group than in the control group (P < 0.05). The collagen pattern was loose and parallel in the experiment group, and the amount of myofibroblast was much less compared with the control group. AABS reduced the amount of inflammatory cells, myofibroblast, and capsular thickness. It also made the collagen fibers in the capsule loose and parallel. Therefore, AABS seemed to be effective in reducing the periimplant capsule formation.

Novel polysaccharide-derived hydrogel prevents perineural adhesions in a rat model of sciatic nerve adhesion

We investigated the effects of a novel carboxymethylcellulose (CMC)-derived hydrogel, in which phosphatidylethanolamine (PE) was introduced into the carboxyl groups of CMC, for preventing perineural adhesion after extensive internal neurolysis of rat sciatic nerve. Sciatic nerves were randomly assigned to one of the following groups: the Control group, operated but no treatment; the HA group, operated and treated with 1% hyaluronan; the CMC-PE(L) group, operated and treated with low-viscosity CMC-PE hydrogel; and the CMC-PE(H) group, operated and treated with high-viscosity CMC-PE hydrogel. Perineural adhesions were evaluated at 6 weeks. Nerves were also subjected to biomechanical testing to assess ultimate breaking strength. Electrophysiological and wet muscle weight measurements were performed. Breaking strengths were significantly lower for the CMC-PE(L) group than for the Control and HA groups. Latency was significantly longer for the Control group than for the CMC-PE(L) group at 20 days. The mean percentage of wet muscle weight to body weight was significantly lower for the Control group than for the CMC-PE(L) group at 6 weeks. Low-viscosity CMC-PE hydrogel appears to prevent perineural adhesions and allow early restoration of nerve function.

Orbital wall fracture repair using Seprafilm

PURPOSE

Seprafilm is a hybrid product of carboxymethylcellulose and sodium hyaluronate that can act as an absorbable barrier to decrease the formation and severity of postoperative adhesions in abdominal, thoracic, and pelvic surgeries. The authors report their experience with use of Seprafilm in "trap door" orbital wall fracture repair.

METHODS

Retrospective case series of 4 consecutive patients with trap door orbital wall fractures secondary to blunt trauma with entrapped orbital soft tissue who underwent surgical repair with placement of Seprafilm implant in 2008. Orbitotomy was performed via standard transconjunctival and/or transcaruncular approaches with release of entrapped tissues, and placement of Seprafilm implant over the fracture site without fixation. Patients were followed for at least 6 months. Ophthalmic and orbital examinations, including ocular motility and Hertel exophthalmometry measurements, were recorded.

RESULTS

All 6 orbital wall fractures (4 floor, 2 medial wall) were successfully corrected with resolution of restrictive motility in the follow-up period (average 10 months; range 6 months to 1.5 years). Mean patient age was 13.5 years (range, 9-20 years). Two of the 4 patients had 2 separate fractures. There were no complications and no need for reoperation.

CONCLUSIONS

Seprafilm may have a role in reconstruction of the "trap door" type of orbital wall fractures. The ease of use, lack of fixation, and absorbable properties without inflammation are encouraging for further study.

The new adhesion prophylaxis membrane A-part--from in vitro testing to first in vivo results

INTRODUCTION

Formation of postoperative intra-abdominal adhesions is a severe problem in surgery. Apart from standard surgical procedures, a variety of different substances is available to prevent adhesions, but no universal method has been developed so far. A membrane consisting of polyvinyl alcohol (PVA) and carboxymethylcellulose (CMC) has been demonstrated to be antiadhesive. Here, the in vitro testing and first in vivo results in a rabbit sidewall model are reported.

MATERIALS AND METHODS

A-part membrane contains a PVA/CMC mixture in a thickness of 40 microm. The composition, dissolution, tensile strength, and elasticity were examined to characterize the membrane in vitro. Experiments in vivo were carried out using a 'rabbit sidewall model' in which a standardized peritoneal trauma was covered with a 5 x 6 cm A-part membrane. Adhesion formation in A-part-treated animals was compared with that in Adept (15 mL/kg body weight) and untreated controls.

RESULTS

An 80/20 PVA/CMC mixture forms a stable, elastic, transparent membrane, which can easily be placed intraoperatively. The dissolution shows a half-life of about 2 weeks [day 15: (45.1 +/- 4.9)% SD], which affords good adhesion protection during the initial critical phase of adhesion formation. In wet conditions, the membrane follows abdominal movements without tearing (tensile strength 5.0 +/- 4.2 N/cm SD; elasticity 29.5%). In a rabbit sidewall model, A-part membrane significantly reduced adhesion development by (83.1 +/- 31.5)% SD compared with the control and the Adept group (p < 0.001).

CONCLUSION

The properties of the A-part membrane suggest that it may be useful as an antiadhesive in surgery. A-part is effective in in vivo testing as determined in a rabbit sidewall model.