Adhesion prevention agents for gynaecological surgery: an overview of Cochrane reviews

Degradable Temperature-Sensitive Hydrogel Loaded with Heparin Effectively Prevents Post-Operative Tissue Adhesions

Tissue adhesions could occur following surgeries, and severe tissue adhesions can lead to serious complications. Medical hydrogels could be applied at surgical sites as a physical barrier to prevent tissue adhesion. For practical reasons, spreadable, degradable, and self-healable gels are highly demanded. To meet these requirements, we applied carboxymethyl chitosan (CMCS) to poloxamer-based hydrogels to generate low Poloxamer₃₃₈ (P₃₃₈) content gels displaying low viscosity at refrigerator temperature and improved mechanical strength at body temperature. Heparin, an effective adhesion inhibitor, was also added to construct P₃₃₈/CMCS-heparin composite hydrogel (PCHgel). PCHgel presents as a flowable liquid below 20 °C and could rapidly transform into gel when spread on the surface of damaged tissue due to temperature change. The introduction of CMCS enabled hydrogels to form a stable self-healable barrier at injured positions and slowly release heparin during the wound healing period before being degraded after ∼14 days. Ultimately, PCHgel significantly reduced tissue adhesion in model rats and displayed higher efficiency than P₃₃₈/CMCS gel without heparin. Its adhesion suppression mechanism was verified, and it also displayed good biosafety. Therefore, PCHgel showed good clinical transformation potential with high efficacy, good safety, and ease of use.

Effects of Icodextrin Solution (Adept®) on Ovarian Cancer Cell Proliferation in an In Vitro Model

Background and objective: Anti-adhesion barriers are currently used during ovarian cancer surgery to decrease adhesion-related morbidity. Adept® (4% icodextrin) solution, a liquid anti-adhesion material, has been widely used during gynecologic surgeries, though the risk of this barrier for oncologic surgery is controversial. The aim of this study was to determine the effect of Adept® solution on the proliferation of ovarian cancer cells. Materials and methods: We assessed the dose- and time-dependent effects of icodextrin on the growth and proliferation of OVCAR-3 and A2780 human ovarian tumor cell lines in vitro. Cell growth was determined by cell number counting. Expressions of cell cycle-regulation proteins (cyclin D1 and cyclin B1) were determined using Western blot analysis. Results: Adept® did not significantly increase ovarian cancer cell growth when tested at various concentrations (0, 1, 5, 10, 15, and 20%, equal to 0, 0.04, 0.2, 0.4, 0.6 and 0.8% icodextrin) and different time points (1–3 days) compared to control cells. Moreover, the protein levels of cyclin D1 and B1 were not overexpression-elevated in icodextrin-treated ovarian cancer cells, either with an increasing concentration or with an increasing treated time. These results demonstrated that Adept® does not activate the growth or proliferation of ovarian cancer cells in either a dose- or time-dependent manner. Conclusions: This study supports the use of Adept® solution as a safe anti-adhesion barrier for ovarian cancer surgery, though further in vivo studies are necessary.

PuraStat RADA16 Self-Assembling Peptide Reduces Postoperative Abdominal Adhesion Formation in a Rabbit Cecal Sidewall Injury Model

Objective: To evaluate the effect of PuraStat (2.5% RADA16) administration on postoperative abdominal adhesion formation in an in vivo model.

Methods: Anesthetized New Zealand white rabbits underwent cecal sidewall abrasion surgery in which the cecal serosa and juxtaposed parietal peritoneum were abraded after access through an abdominal midline incision. Eight animals were randomized to receive PuraStat administration at the interface of the injured tissues before incision closure, and five animals served as untreated controls. Treated animals received 3–12 ml PuraStat solution per lesion. Animals were sacrificed 14 days after surgery and examined for adhesion formation at the wound site.

Results: At study terminus, adhesions were identified in 90% (9/10) of abraded cecum/peritoneal wound sites in untreated controls versus 25% (4/16) of PuraStat-treated sites (p = 0.004). Mean ± SD Total Adhesion Score (average of the values for extent + strength of the adhesion in both defects per animal; maximum score = 14 points) was significantly 76% lower in PuraStat-treated animals (2.0 ± 3.0 points) compared to untreated controls (8.2 ± 1.9 points) (p = 0.029). Mean adhesion coverage area of wound sites was 79% lower in PuraStat-treated animals than controls (p < 0.001), and mean adhesion durability was 72% lower in PuraStat-treated animals versus controls (p = 0.005). Remnant hydrogel was observed at the wound sites of 75% of treated animals at postoperative Day 14.

Conclusion: PuraStat treatment has a positive protective effect in the cecal sidewall injury model, and significantly reduces abdominal adhesion formation at the interface of the injured cecum and overlying peritoneal sidewall defect.

Focus on the Primary Prevention of Intrauterine Adhesions: Current Concept and Vision

Intrauterine adhesion (IUA), and its severe form Asherman syndrome (Asherman’s syndrome), is a mysterious disease, often accompanied with severe clinical problems contributing to a significant impairment of reproductive function, such as menstrual disturbance (amenorrhea), infertility or recurrent pregnancy loss. Among these, its correlated infertility may be one of the most challenging problems. Although there are many etiologies for the development of IUA, uterine instrumentation is the main cause of IUA. Additionally, more complicated intrauterine surgeries can be performed by advanced technology, further increasing the risk of IUA. Strategies attempting to minimize the risk and reducing its severity are urgently needed. The current review will expand the level of our knowledge required to face the troublesome disease of IUA. It is separated into six sections, addressing the introduction of the normal cyclic endometrial repairing process and its abruption causing the formation of IUA; the etiology and prevalence of IUA; the diagnosis of IUA; the classification of IUA; the pathophysiology of IUA; and the primary prevention of IUA, including (1) delicate surgical techniques, such as the use of surgical instruments, energy systems, and pre-hysteroscopic management, (2) barrier methods, such as gels, intrauterine devices, intrauterine balloons, as well as membrane structures containing hyaluronate–carboxymethylcellulose or polyethylene oxide–sodium carboxymethylcellulose as anti-adhesive barrier.

Biomaterials to Prevent Post-Operative Adhesion

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

Post-surgical adhesions are triggered by calcium-dependent membrane bridges between mesothelial surfaces

Surgical adhesions are bands of scar tissues that abnormally conjoin organ surfaces. Adhesions are a major cause of post-operative and dialysis-related complications, yet their patho-mechanism remains elusive, and prevention agents in clinical trials have thus far failed to achieve efficacy. Here, we uncover the adhesion initiation mechanism by coating beads with human mesothelial cells that normally line organ surfaces, and viewing them under adhesion stimuli. We document expansive membrane protrusions from mesothelia that tether beads with massive accompanying adherence forces. Membrane protrusions precede matrix deposition, and can transmit adhesion stimuli to healthy surfaces. We identify cytoskeletal effectors and calcium signaling as molecular triggers that initiate surgical adhesions. A single, localized dose targeting these early germinal events completely prevented adhesions in a preclinical mouse model, and in human assays. Our findings classifies the adhesion pathology as originating from mesothelial membrane bridges and offer a radically new therapeutic approach to treat adhesions.

Surgical adhesions are organ-joining bands of scar tissue that remain clinically untreatable. Here, the authors show that adhesions are formed through expansive mesothelial membrane bridges, and that blocking these with small molecules prevents formation of adhesions in mice.

Crosslinked Hyaluronic Acid Gels for the Prevention of Intrauterine Adhesions after a Hysteroscopic Myomectomy in Women with Submucosal Myomas: A Prospective, Randomized, Controlled Trial

Intrauterine adhesion (IUA), fibrosis, and scarring resulting from damage to the endometrium is a rare but serious clinical disease, contributing to a significant impairment of reproductive function. Uterine instrumentation, especially that of a hysteroscopic myomectomy, has become the main cause of IUA. Therefore, a prospective randomized controlled study to assess the effectiveness and short-term safety of the use of hyaluronic acid gels in the prevention of IUA after a hysteroscopic myomectomy and an evaluation of the characteristics of IUA observed at follow-up are presented here. A total of 70 patients were analyzed at the end of 16 March 2020. The results show that the incidence of IUA in women who underwent a hysteroscopic myomectomy is 21.4% (15/70), overall. Women treated with hyaluronic acid gels have a statistically significantly lower incidence of IUAs than non-treated women (12.8% vs. 39.1%, p = 0.012). In addition, women in the anti-adhesive gel treatment group had a dramatically reduced severity of IUA than women in the no-treatment group (p = 0.002). Further analysis shows that the International Federation of Gynecology and Obstetrics (FIGO) classification type and the use of anti-adhesive gels are independent factors associated with moderate and severe degrees of IUA formation. The results here highlight the significant therapeutic benefits of the application of hyaluronic acid gels in women undergoing a hysteroscopic myomectomy, especially for those patients with a uterine myoma classified as FIGO type 2. Since the risk of IUA after a hysteroscopic myomectomy is high, especially for patients who have not received prophylactic anti-adhesive gels, the application of hyaluronic acid gels as a prevention strategy is highly recommended. More studies are encouraged to confirm our observation.

Surgical adhesions among women undergoing laparoscopic gynecological surgery with or without adhesiolysis - prevalence, severity, and implications: retrospective cohort study at a University Hospital

Objective:

To find out the prevalence of adhesions, severity, and their relation to the current clinical scenario and to the type of previous surgery.

Methods and Materials:

A retrospective study of patients who already had different previous abdominopelvic surgery and subsequently underwent gynecological laparoscopic surgery for various indications. The patients’ clinical and operative notes were reviewed and analyzed.

Results:

There were 654 procedures performed. The most common indication for the laparoscopic surgery was secondary infertility 23.5%, followed by adnexal lesions 22.0% and primary infertility 19.6%. Intraoperative adhesions were found in 45.3%. Adhesions were deemed relevant to the clinical scenario in 21.3%. Patients who had a previous history of open (traditional) surgery were more likely to be found with adhesions in comparison with patients with history of laparoscopic surgery (odds ratio: 2.7, 95% confidence interval: 1.4–5.3, p = 0.0025). The presence of adhesions was found to be strongly associated with previous abdominopelvic surgery than non-abdominopelvic surgery (odds ratio: 4.3, p = 0.0078, 95% confidence interval: 1.5–12.5). The most common location of the adhesions was abdominal (36.1%), mixed abdominal and pelvic (35.1%), and pelvic adhesions (28.1%). Severe adhesions were found in 36.1%; 13.6% of converted laparoscopy to open surgery was due to adhesions. Cesarean sections were significantly associated with adhesions. Patients who had cesarean sections were more likely to have adhesions than those who had not (odds ratio: 5.7, 95% confidence interval: 3.8–8.6, p < 0.0001). Adhesiolysis was done without complications in 19.6% of patients with adhesions.

Conclusion:

Adhesions were prevalent in gynecological patients with previous abdominopelvic surgery. They were a significant contributor to the gynecological and reproductive issues. To minimize the risk of postoperative adhesions, laparoscopic approach should be encouraged instead of traditional surgery and rates of cesarean section should be reduced. Further high-quality studies are needed to establish conclusion and practical guidance toward the use of adhesion barriers.

Does applied ultrasound prior to laparoscopy predict the existence of intra-abdominal adhesions?

Background/aim

The purpose of this study was to evaluate the efficacy of trans-abdominal ultrasonography (USG), a noninvasive diagnostic tool, in predicting the presence of intraabdominal adhesions, especially near the trocar entry area, to provide safe surgical access to the abdomen.

Materials and methods

Fifty-nine women with a previous history of open abdominal surgery (group A) and a group of 91 women with no previous history of surgery (group B) underwent dynamic ultrasound evaluation of the abdominal fields before laparoscopic operations. The anterior abdominal wall was divided into six quadrants: right upper, right lower, left upper, left lower, suprapubic, and umbilical. Adhesions were evaluated by surgeons during the operation and by radiologists using USG prior to the operation. Visceral organ movements greater than 1 cm was defined as normal visceral slide (positive test), with less than 1 cm of movement defined as abnormal visceral slide (negative test). Sliding test measures movements of omental echogenicity or a stable echogenic focus that corresponds to intestine peritoneal echogenicity that underlies abdominal wall during exaggerated inspiration and expiration. Adhesions observed during surgery were evaluated on a four-point scale, with 0 indicating no adhesions present, 1 indicating the presence of a thin, filmy avascular adhesion, 2 indicating the presence of a dense and vascular adhesion, and 3 indicating adhesions that connect surrounding organs with the overlying peritoneal surfaces. The McNemar test was used to compare the results of USG and laparoscopy for each measure.

Results

We found that preoperative USG was successful in identifying adhesions [sensitivity, 96.39% (95% CI 89.8–99.2); specificity, 97.43%]

Conclusion

Preoperative ultrasound examination of the abdominal wall may enhance the safety of abdominal entry during laparoscopic operations.

Practical considerations in the use of a porcine model (Sus scrofa domesticus) to assess prevention of postoperative peritubal adhesions

Infertility has been a common postoperative problem caused by peritoneal adhesions. Since several prophylactic agents have recently shown promising preliminary results, more complete studies comparing their real efficacy and safety are needed urgently. The aim of this study was to investigate and describe practical considerations of a porcine model that can be used to assess such prophylactic agents. First, 10 healthy 5½ months old female pigs (24.3-31.3 Kg) underwent a standardized laparoscopy to provoke peritubal adhesion formation without prophylactic agents. After 30 days, a second-look laparoscopy was performed to evaluate adhesions and perform adnexectomy for histopathological evaluation. Adhesions at different sites were classified by grade, for which the scores range from 0 (no adhesion) to 3 (very strong vascularized adhesions), and also by area, with scores ranging from 0 (no adhesion) to 4 (>75% of the injured area). The histopathological evaluation of the distal uterine horns, oviducts and ovaries were compared withthose from a control group of six healthy pigs with no previous surgery. Biological samples were collected to assess vitality, inflammation and renal, hepatic and hematopoietic systems. There were small (but significant) changes in serum albumin (P = 0.07), globulin (P = 0.07), C-reactive protein (P = 0.011), fibrinogen (P = 0.023) and bilirubin (P<0.01) after 30 days, but all values were within the normal range. No inflammation or abscess formation was observed, but different degrees of adhesion were identified. The estimated occurrence of adhesion (scores >0) and of strong / very strong adhesion (scores >1) was 75% (95% CI: 55-94.9) and 65% (95% CI: 45-85), respectively. The porcine model represents a useful animal platform that can be used to test the efficacy and safety of candidate prophylactic agents intended to prevent postoperative peritubal adhesions formation. We present several practical considerations and measures that can help to minimize animal suffering and avoid problems during such experiments.

Danhong Injection Alleviates Postoperative Intra-abdominal Adhesion in a Rat Model

Background

Among all the common complications that occur after abdominal surgery, intestinal adhesion is perhaps the most unpleasant one. However, current methods to treat and prevent intestinal adhesion are limited; thus, exploring new methods to prevent and treat intestinal adhesion is greatly needed. In this study, we demonstrated that Danhong injection (DHI) may be used as a promising method to prevent and treat intra-abdominal adhesion in a rat model.

Materials and Methods

Forty-eight rats were randomly divided into six groups. Except for the sham-operated group, all rats underwent cecal abrasion to establish an adhesion model. After the operation, the rats in the DHI-treated groups received different doses of DHI via the tail vein daily, while the other group was treated with the same volume of saline solution. Seven days after the operation, all rats were sacrificed, and the degree of adhesion was evaluated by Nair's scoring system. The extent of inflammation in the adhesion tissue was detected by HE staining and the expression of tumor necrosis factor-α (TNF-α) and transforming growth factor-β (TGF-β). The collagen deposition was assessed by Sirius red staining and α-SMA, MMP9, t-PA, and PAI-1 levels. Oxidative stress was indicated by the level of reactive oxygen species (ROS) in adhesion tissues and by immunohistochemical labeling of Nrf2. Furthermore, rat primary peritoneal mesothelial cells (RPMCs) were treated with H₂O₂ and DHI, and NF-κB phosphorylation was detected to illustrate the effect of DHI on oxidative stress.

Results

The intra-abdominal adhesion scores were significantly decreased in the groups treated with a high dose of DHI compared with the control groups, and the degree of inflammation, fibrosis, and oxidative stress was also significantly decreased. DHI treatment significantly reduced the levels of TNF-α, TGF-β1, and PAI and increased the expression levels of MMP9, Nrf2, and t-PA in the adhesion tissues. ROS levels and NF-κB phosphorylation were significantly reduced in DHI-treated RPMCs compared with the control RPMCs.

Conclusion

DHI alleviates the formation of postoperative intra-abdominal adhesions by inhibiting inflammation, collagen deposition, and oxidative stress in a rat model and may serve as a promising drug to prevent intra-abdominal adhesions.

Fucoidans inhibit the formation of post-operative abdominal adhesions in a rat model

Purpose

Fibrin clot is essential for post-operative abdominal adhesion formation. Fucoidans, sulfated polysaccharides, inhibit fibrin clot formation. In addition, they inhibit inflammation and fibrosis, which also play important roles in adhesion formation. The purpose of this study was to evaluate fucoidans’ potential for inhibiting post-operative abdominal adhesions and measure their effects on systemic coagulation parameters when administered intraperitoneally (IP).

Methods and materials

Female Sprague Dawley rats were studied. A 2.5x2.5cm full thickness segment of abdominal wall was excised. The skin edges were approximated. This model induces extensive adhesions and allows objective quantitation. Three fucoidans were evaluated- Sigma Fucoidan Crude (SFC), Fucus vesiculosis 95% (Sigma) and, Peridan. One protocol involved continuous infusion into the abdomen from a subcutaneous osmotic pump. Alternatively, boluses of the solutions were injected IP at the end of the operation. Rats were sacrificed a week later. Adhesion extent was scored. Systemic coagulation effects of fucoidans were also evaluated. INR and aPTT were measured following IP injection of the fucoidan solutions and after 7 days of continuous infusion.

Results

Animals given a continuous infusion of either SFC or Peridan yielded adhesion reduction of 80 to 90% from control. Bolus Peridan had no discernable influence on adhesion formation, but a single bolus of SFC caused significant adhesion reductions. Peridan resulted in prompt aPTT elevations which fell to nearly normal by 5 hours. The maximum peak value after SFC injection was seen in 15 hours. The maximal INR elevations were around 2. Measurement of INR and aPTT after a week of continuous infusion of either Peridan or SFC, were always in the normal control range. The third agent, Sigma, frequently yielded intraperitoneal infection found at autopsy.

Conclusions

These findings indicate that selected fucoidans infused intraperitoneally for a week after abdominal operations reduce adhesion extent by up to 90%.

Impact on Patient Care of a Multidisciplinary Center Specializing in Colorectal and Pelvic Reconstruction

Aim of the study: Many patients with an anorectal malformation (ARM) or pelvic anomaly have associated urologic or gynecologic problems. We hypothesized that our multidisciplinary center, which integrates pediatric colorectal, urologic, gynecologic and GI motility services, could impact a patient's anesthetic exposures and hospital visits.

Methods: We tabulated during 2015 anesthetic/surgical events, endotracheal intubations, and clinic/hospital visits for all patients having a combined procedure.

Main results: Eighty two patients underwent 132 combined procedures (Table 1). The median age at intervention was 3 years [0.2-17], and length of follow up was 25 months [7-31]. The number of procedures in patients who underwent combined surgery was lower as compared to if they had been done independently [1(1-5) vs. 3(2-7) (p < 0.001)]. Intubations were also lower [1[1-3] vs. 2[1-6]; p < 0.001]. Hospital length of stay was significantly lower for the combined procedures vs. the theoretical individual procedures [8 days [3-20] vs. 10 days [4-16]] p < 0.05. Post-operative clinic visits were fewer when combined visits were coordinated as compared to the theoretical individual clinic visits (urology, gynecology, and colorectal) [1[1-4] vs. 2[1-6]; p = < 0.001].

Conclusions: Patients with anorectal and pelvic malformations are likely to have many medical or surgical interventions during their lifetime. A multidisciplinary approach can reduce surgical interventions, anesthetic procedures, endotracheal intubations, and hospital/outpatient visits.

A new bioabsorbable polymer film to prevent peritoneal adhesions validated in a post-surgical animal model

Background

Peritoneal adhesions are a serious surgical postoperative complication. The aim of this study is to investigate, in a rat model, the anti-adhesive effects of a bioabsorbable film of polymer combining polyethylene glycol and polylactic acid.

Materials and methods

Sixty-three animals were randomized into five groups according to the anti-adhesion treatment: Hyalobarrier^®, Seprafilm^®, Polymer A (PA), Polymer B (PB), and control. The rats were euthanized on days 5 and 12 to evaluate the extent, severity and degree of adhesions and histopathological changes. Three animals were euthanized at day 2 in PA, PB and control groups to observe the in vivo elimination.

Results

Macroscopic adhesion formation was significantly lower in the PA group than in the control group at day 5 (median adhesion score 0±0 vs 9.6 ±0.5 p = 0.002) and at day 12 (0±0 vs 7.3±4 p = 0.02). Furthermore, median adhesion score at day 5 was significantly lower in the PA group than in the Seprafilm group (0±0 vs 4.2± 3.9 p = 0.03). Residence time of PA seems longer than PB.

Conclusion

The PA bioabsorbable film seems efficient in preventing the formation of peritoneal adhesions.

Prevalence of adhesions and associated postoperative complications after cesarean section in Ghana: a prospective cohort study

BACKGROUND

The global increase in Cesarean section rate is associated with short- and long-term complications, including adhesions with potential serious maternal and fetal consequences. This study investigated the prevalence of adhesions and association between adhesions and postoperative complications in a tertiary referral hospital in Accra, Ghana.

METHODS

In this prospective cohort study, 335 women scheduled for cesarean section at Korle-Bu Teaching Hospital in Accra, Ghana were included from June to December 2015. Presence or absence of adhesions was recorded and the severity of the adhesions was scored using a classification system. Associations between presence and severity of adhesions, postoperative complications, and maternal and infant outcomes at discharge and 6 weeks postpartum were assessed using multivariate logistic and linear regression analysis.

RESULTS

Of the participating women, 128 (38%) had adhesions and 207 (62%) did not. Prevalence of adhesions increased with history of caesarean section; 2.8% with no CS but may have had an abdominal surgery, 51% with one previous CS, 62% with >1 CS). Adhesions significantly increased operation time (mean 39.2 (±15.1) minutes, absolute adjusted difference with presence of adhesions 9.6 min, 95%CI 6.4-12.8), infant delivery time (mean 5.4 (±4.8) minutes, adjusted difference 2.4 min, 95%CI 1.3-3.4), and blood loss for women with severe adhesions (mean blood loss 418.8 ml (±140.6), adjusted difference 57.6 ml (95%CI 12.1-103.0). No differences for other outcomes were observed.

CONCLUSION

With cesarean section rates rising globally, intra-abdominal adhesions occur more frequently. Risks of adhesions and associated complications should be considered in counseling patients for cesarean section.

Decision Making in Bowel Obstruction: A Review

Over the last century there have not been significant changes in the anatomical location of obstruction. The age of presentation has increased along with age related co-morbidity. Management has consequently been challenging as risks keep on increasing with advanced age. Hence, clear decision making has become essential in its management. A selective review of the literature pertaining to common age related aetiologies, diagnosis methods leading to standard decision making and treatment of acute intestinal obstruction was done. The same is obtained from randomized controlled studies, meta-analysis and other related evidence based publications. Predicting the conservative or operative management of Bowel Obstruction (BO) is difficult. BO in young age, in unscarred abdomen and Large Bowel Obstruction (LBO) needs early surgery. Decision on surgery should be taken in paediatric patient by second day and preferably between 3-5 days of admission in adults. Higher American Society of Anaesthesiologists (ASA) grade correlates well with the mortalities. In this article, the timing of surgery, methods to avoid bowel resection and type of surgery in various causes are stressfully analysed and discussed.

Hyaluronic acid and oxidized regenerated cellulose prevent adhesion reformation after adhesiolysis in rat models

Postsurgical adhesion formation is the most common complication in abdominal and pelvic surgery. Adhesiolysis is the most commonly applied treatment for adhesion formation but is often followed by adhesion reformation. Therefore, an efficient strategy should be adopted to solve these problems. This study aimed to explore whether hyaluronic acid and oxidized regenerated cellulose (ORC) could prevent adhesion formation and reformation. Thirty female Sprague Dawley rats were randomly divided into three groups (n=10 each) and subjected to different treatments during the first and second surgery. The control group was treated with isotonic sodium chloride, the ORC group was treated with ORC (1.5×1 cm), and the medical sodium hyaluronate (MSH) group was treated with 1% MSH (0.5 mL). At 2 weeks after the first surgery, adhesion scores in the MSH group (1.90±0.99) and the ORC group (1.40±0.97) were significantly lower than those in the control group (3.00±0.82) (P=0.005). Similarly, 2 weeks after the second surgery, adhesion scores in the MSH group (2.00±0.82) and the ORC group (1.50±1.27) were significantly lower than those in the control group (3.50±0.53) (P=0.001). In addition, body weights in the MSH group and the ORC group did not change significantly, whereas the control group showed a consistent decrease in body weight during the experiment. Histological examination revealed that inflammatory infiltration was involved in both adhesion formation and reformation. In conclusion, hyaluronic acid and ORC were both efficient in reducing adhesion formation and reformation in the rat model.

Adhesive small bowel adhesions obstruction: Evolutions in diagnosis, management and prevention

Intra-abdominal adhesions following abdominal surgery represent a major unsolved problem. They are the first cause of small bowel obstruction. Diagnosis is based on clinical evaluation, water-soluble contrast follow-through and computed tomography scan. For patients presenting no signs of strangulation, peritonitis or severe intestinal impairment there is good evidence to support non-operative management. Open surgery is the preferred method for the surgical treatment of adhesive small bowel obstruction, in case of suspected strangulation or after failed conservative management, but laparoscopy is gaining widespread acceptance especially in selected group of patients. "Good" surgical technique and anti-adhesive barriers are the main current concepts of adhesion prevention. We discuss current knowledge in modern diagnosis and evolving strategies for management and prevention that are leading to stratified care for patients.

Adhesion prevention agents for gynaecological surgery: an overview of Cochrane reviews

BACKGROUND

Intraperitoneal adhesions are associated with considerable co-morbidity and have large financial and public health repercussions. They have secondary effects that include chronic pelvic pain, dyspareunia, subfertility and bowel obstruction. In women with adhesions, subsequent surgery is more difficult, often takes longer, and is associated with a higher complication rate (Broek 2013). The significant burden of adhesions has led to the development of several anti-adhesion agents, although there is disagreement as to their relative effectiveness.

OBJECTIVES

To summarise evidence derived from Cochrane systematic reviews on the clinical safety and effectiveness of solid agents, gel agents, liquid agents and pharmacological agents, used as adjuvants to prevent formation of adhesions after gynaecological pelvic surgery.

METHODS

The Cochrane Database of Systematic Reviews was searched using the keyword 'adhesion' up to August 2014. The Cochrane information management system was also searched for any titles or protocols of reviews in progress. Two review authors independently extracted information from the reviews, with disagreements being resolved by a third review author. The quality of the included reviews was described in a narrative manner, and the AMSTAR tool was used to formally assess each review included in this overview. The quality of evidence provided in the original reviews was described using GRADE methods.

MAIN RESULTS

We included two reviews, one with 18 studies comparing solid agents (oxidised regenerated cellulose expanded polytetrafluoroethylene, sodium hyaluronate and carboxymethylcellulose, and fibrin sheets) with control or with each other. The other review included 29 studies which compared liquid agents (4% icodextrin, 32% dextran, crystalloids), gel agents (carboxymethylcellulose and polyethylene oxide, polyethylene glycol gels, hyaluronic acid based gel, 0.5% ferric hyaluronate gel, sodium hyaluronate spray) and pharmacological agents (gonadotrophin-releasing hormone agonist, reteplase plasminogen activator, N,O-carboxymethyl chitosan, steroid agents, intraperitoneal noxytioline, intraperitoneal heparin, systemic promethazine) with control or each other. Both reviews met all of the criteria of the AMSTAR assessment.The reviews included as outcomes both the primary outcomes of this overview (pelvic pain, pregnancy, live birth rate and quality of life (QoL)) and our secondary outcomes (adverse effects, presence or absence of adhesions at second-look laparoscopy (SLL) and adhesion score). However, neither of the reviews identified any primary studies of solid, gel or pharmacological agents that reported any of our primary outcomes. The only studies in either review that reported any of our primary outcomes were studies comparing liquid agents versus control (saline or Hartmann's solution), which reported pelvic pain (two studies), live birth (two studies) and pregnancy (three studies).An external source of funding was stated for 25 of the 47 studies across both reviews; in 24 of these studies the funding was commercial. Solid agents (18 studies)None of our primary outcomes were reported. Adverse events were reported as an outcome by only 9 of the 18 studies. These reported no adverse events. Liquid agents (nine studies)There was no evidence of a difference between liquid agents and control (saline or Hartmann's solution) with respect to pelvic pain (odds ratio (OR) 0.65, 95% confidence interval (CI) 0.37 to 1.14, 1 study, n = 286, moderate quality evidence), pregnancy rate (OR 0.64, 95% CI 0.36 to 1.14, 3 studies, n = 310, moderate quality evidence) or live birth rate (OR 0.67, 95% CI 0.29 to 1.58, 2 studies, n = 208, moderate quality evidence). No studies of liquid agents reported QoL. Adverse events were not reported as an outcome by any of the nine studies. Gel agents (seven studies)None of our primary outcomes were reported. Adverse events were not reported as an outcome by any of the seven studies. Pharmacological agents (seven studies)None of our primary outcomes were reported. Adverse events were reported as an outcome by only one of the seven primary studies. This study reported no evidence of difference in ectopic pregnancy rates between intraperitoneal noxytioline and no treatment (OR 4.91, 95% CI 0.45 to 53.27, 1 study, n = 33, low quality evidence).

AUTHORS' CONCLUSIONS

There is insufficient evidence to allow us to draw any conclusions about the effectiveness and safety of anti-adhesion agents in gynaecological surgery, due to the lack of data on pelvic pain, fertility outcomes, quality of life or safety. A substantial proportion of research in this field has been funded by private companies that manufacture these agents, and further high powered, independent trials will be needed before definitive conclusions can be made.