Intra-peritoneal prophylactic agents for preventing adhesions and adhesive intestinal obstruction after non-gynaecological abdominal surgery

Spray-Type Adhesion Barrier Enhances Safety and Feasibility of Robotic Repeat Liver Resection: Initial Experience and Outcomes

Background Although various types of adhesion barriers are widely utilized in liver surgery, the safety and feasibility of their use during repeat robotic liver resection (R-RLR) are still unknown. Methods Among the 68 patients undergoing RLR with the application of the spray-type adhesion barrier at Kokura Memorial Hospital, Kitakyushu, Japan, between 2021 and 2023, 24 cases that underwent R-RLR were included in this study. The included patients were divided into two groups: those who underwent previous hepatectomy with the use of a spray-type adhesion barrier (R-RLR-B, n = 14) and those without its previous use (R-RLR-NB, n = 10). The perioperative outcomes were compared between the groups. Results There were no differences between the R-RLR-B and R-RLR-NB groups in background characteristics, difficulty scores, operative and console time, or surgical blood loss. Although no difference was found between the groups in the time required for adhesiolysis before the robotic operation, both the time required for robotic adhesiolysis (75 minutes vs. 58 minutes, p = 0.034) and total time for adhesiolysis (192 minutes vs. 141 minutes, p = 0.014) were significantly shorter in the R-RLR-B group than in the R-RLR-NB group. Otherwise, there was no conversion to open hepatectomy, no intraoperative transfusion of red blood cells, no cases of grade B or C post-hepatectomy liver failure, and no mortality in the whole cohort. Conclusions The spray-type adhesion barrier may not be associated with an increase in the incidence of postoperative complications, including bile leakage or intraperitoneal abscess. In addition, its application during the previous hepatectomy can facilitate a secure R-RLR with reduced time for adhesiolysis. Thus, the use of the spray-type adhesion barrier for R-RLR is safe, effective, and time efficient.

Open IPOMs for medium/large incisional ventral hernia repairs in the French Hernia Registry: factors associated with their use and mesh-related outcomes

PURPOSE

The use of open intra-peritoneal onlay mesh repairs (O-IPOMs) for treating medium/large incisional ventral hernias has come into question due to the development of minimally invasive and sublay procedures. This study aimed to identify factors that are associated with the use of O-IPOMs in France.

METHODS

We analysed prospectively collected data from the French Hernia Registry on incisional ventral hernia repairs (IVHR) for hernias ≥ 4 cm in width.

RESULTS

We obtained data for 2261 IVHR (from 11/09/2011 to 30/03/2020): 733 O-IPOMs and 1,528 other techniques. We found that the O-IPOMs were performed on patients with more patient-related risk factors compared with the other techniques. Specifically, there was a higher proportion of patients with ASA III/IV (40.47% vs. 28.02%; p < 0.00001) and at least one patient-related risk factor (66.17% vs. 58.51%; p = 0.0005). Of the 733 O-IPOMs, 195 used Ventrio ST™ (VST), the most commonly used mesh for such IPOMs in our database; the other 538 O-IPOMs used other meshes (OM). The VST subgroup had a higher proportion of patients with ASA III/IV (52.58% vs. 36.07%; p < 0.0001) and on anticoagulants (26.04% vs. 18.41%; p = 0.0229) compared with the OM subgroup; they also had a lower recurrence rate after 2 years (5.83% vs. 15.41%; p = 0.008). However, large (≥ 10 cm) or lateral defects were more common in the OM subgroup, and their mesh/defect area ratio was lower.

CONCLUSION

O-IPOMs were performed on patients with more comorbidities and/or complex incisional hernias compared with other techniques.

Novel nomogram for predicting risk of early postoperative small bowel obstruction after right colectomy for cancer

Background

Early postoperative small bowel obstruction (EPSBO) is a common complication after colorectal cancer surgery. Few studies have specifically studied risk factors for early small bowel obstruction after right colectomy, especially in establishing predictive models. The purpose of the current study was to establish an effective nomogram to predict the incidence of EPSBO after right colectomy.

Methods

The current study retrospectively analyzed data from a total of 424 patients who underwent right colectomy in a local hospital from January 2014 to March 2021. A logistic regression model was used to identify potential risk factors for EPSBO after right colectomy. A nomogram was established by independent risk factors, and the prediction performance of the model was evaluated using an area under the receiver operating characteristic (ROC) curve and calibration chart.

Results

A total of 45 patients (10.6%) developed early small bowel obstruction after right colectomy. Male sex, history of abdominal surgery, open surgery, long operative time, anastomotic leakage, and preoperative albumin were closely related to EPSBO. Analysis of postoperative rehabilitation indices showed that EPSBO remarkably slowed the postoperative rehabilitation speed of patients. Multivariate logistic regression analysis showed that male sex, open surgery, operative time, and anastomotic leakage were independent risk factors (P < 0.05), and the operation time had the greatest impact on EPSBO. On the basis of multivariate logistic regression, a nomogram was constructed, which showed moderate accuracy in predicting EPSBO, with a C-statistic of 0.716. The calibration chart showed good consistency between the predicted probability and ideal probability.

Conclusion

The current study constructed a nomogram based on the clinical data of patients who underwent right colectomy, which had moderate predictability and could provide reference value for clinicians to evaluate the risk of EPSBO.

Small Bowel Obstruction

Small bowel obstruction (SBO) remains a common problem for surgeons and nonsurgeons alike. Management of SBO has shifted from primarily being surgical to a nonoperative approach, which can be attributed to a multitude of reasons, including better understanding of the pathophysiology of SBO, the advent of laparoscopy, and improvement in diagnostic imaging. But given the nature of SBO, the need for surgical consultation continues to remain a necessity. This article will review the etiology, diagnosis, and management of SBO.

Prevention of Post-Operative Adhesions: A Comprehensive Review of Present and Emerging Strategies

Post-operative adhesions affect patients undergoing all types of surgeries. They are associated with serious complications, including higher risk of morbidity and mortality. Given increased hospitalization, longer operative times, and longer length of hospital stay, post-surgical adhesions also pose a great financial burden. Although our knowledge of some of the underlying mechanisms driving adhesion formation has significantly improved over the past two decades, literature has yet to fully explain the pathogenesis and etiology of post-surgical adhesions. As a result, finding an ideal preventative strategy and leveraging appropriate tissue engineering strategies has proven to be difficult. Different products have been developed and enjoyed various levels of success along the translational tissue engineering research spectrum, but their clinical translation has been limited. Herein, we comprehensively review the agents and products that have been developed to mitigate post-operative adhesion formation. We also assess emerging strategies that aid in facilitating precision and personalized medicine to improve outcomes for patients and our healthcare system.

Peritoneal Adhesions and their Prevention - Current Trends

The development of adhesions after gynecologic surgery is a severe problem with ramifications that go beyond the medical complications patients suffer (which most often include pain, obstruction and infertility), since they also impose a huge financial burden on the health care system and increase the workload of surgeons and all personnel involved in surgical follow-up care. Surgical techniques to avoid adhesion formation have not proven to be sufficient and pharmaceutical approaches for their prevention are even less effective, which means that the use of adhesion prevention devices is essential for achieving decent prophylaxis. This review explores the wide range of adhesion prevention products currently available on the market. Particular emphasis is put on prospective randomized controlled clinical trials that include second-look interventions, as these offer the most solid evidence of efficacy. We focused on adhesion scores, which are the most common way to quantify adhesion formation. This enables a direct comparison of the efficacies of different devices. While the greatest amount of data are available for oxidized regenerated cellulose, the outcomes with this adhesion barrier are mediocre and several studies have shown little efficacy. The best results have been achieved using adhesion barriers based on either modified starch, i.e., 4DryField® PH (PlantTec Medical GmbH, Lüneburg, Germany), or expanded polytetrafluoroethylene, i.e., GoreTex (W.L. Gore & Associates, Inc., Medical Products Division, Flagstaff, AZ), albeit the latter, as a non-resorbable barrier, has a huge disadvantage of having to be surgically removed again. Therefore, 4DryField® PH currently appears to be a promising approach and further studies are recommended.

Effectiveness of barrier agents for preventing postoperative bowel obstruction after laparoscopic surgery: a retrospective cohort study

PURPOSE

The effectiveness of using anti-adhesion agents in laparoscopic surgery is controversial. We compared the outcomes of patients exposed to anti-adhesion agents (barrier group) with those of patients not exposed (no barrier group) in laparoscopic surgery.

METHODS

Using a nationwide claim-based database in Japan, we analyzed data from patients who underwent laparoscopic surgery between 2005 and 2019 and compared the patient characteristics and the proportion of those with bowel obstruction between the barrier and no barrier groups. We also performed several sensitivity and subgroup analyses.

RESULTS

Of the 57,499 patients who met the inclusion criteria, 14,360 and 43,139 were assigned to the barrier and no barrier groups, respectively. The proportion of patients with a bowel obstruction in the two groups did not differ among all patients hospitalized for obstruction (1.1 vs. 1.1%, p = 0.63) and those requiring surgery (0.2 vs. 0.2%, p = 0.39). In the sensitivity analysis with propensity score matching, the incidences of bowel obstruction between the barrier and non-barrier groups were equivocal (1.3 vs. 1.6%), but statistically marginal (chi-square test, p = 0.035; log-rank test, p = 0.09).

CONCLUSION

The use of barrier agents for adhesive prevention did not show clear effectiveness for the prevention of bowel obstruction after laparoscopic surgery for unselected cases. Further studies focusing on more specific procedures are needed.

Enhancing delivery of small molecule and cell-based therapies for ovarian cancer using advanced delivery strategies

Ovarian cancer is the most lethal gynecological malignancy with a global five-year survival rate of 30-50%. First-line treatment involves cytoreductive surgery and administration of platinum-based small molecules and paclitaxel. These therapies were traditionally administered via intravenous infusion, although intraperitoneal delivery has also been investigated. Initial clinical trials of intraperitoneal administration for ovarian cancer indicated significant improvements in overall survival compared to intravenous delivery, but this result is not consistent across all studies performed. Recently cell-based immunotherapy has been of interest for ovarian cancer. Direct intraperitoneal delivery of cell-based immunotherapies might prompt local immunoregulatory mechanisms to act synergistically with the delivered immunotherapy. Based on this theory, pre-clinical in vivo studies have delivered these cell-based immunotherapies via the intraperitoneal route, with promising results. However, successful intraperitoneal delivery of cell-based immunotherapy and clinical adoption of this technique will depend on overcoming challenges of intraperitoneal delivery and finding the optimal combinations of dose, therapeutic and delivery route. We review the potential advantages and disadvantages of intraperitoneal delivery of cell-based immunotherapy for ovarian cancer and the pre-clinical and clinical work performed so far. Potential advanced delivery strategies, which might improve the efficacy and adoption of intraperitoneal delivery of therapy for ovarian cancer, are also outlined.

An Evaluation of Wound Healing Efficacy of a Film Dressing Made from Polymer-integrated Amnion Membrane

A film dressing is an easy and common wound management, which is flexible to cover many types of superficial injuries. In a recent study, we developed a scaffold from poly (1,8-octanediolco-citrate) incorporated decellularized amnion membrane (DAM-POC). The DAM-POC scaffold was biocompatible and could enhance soft and hard tissue regeneration when applied to repair the cleft palate in rat. The efficacy of the DAM-POC scaffold in oral repair had led us to hypothesize that it could be employed extensively in the medical field as a wound dressing. This study aimed to investigate the feasibility and efficacy of the DAM-POC scaffold as a film dressing in accelerating wound healing when applied in multiple tissue injuries. Our results demonstrated that both the DAM and DAM-POC scaffolds were biocompatible and anti-adhesive without causing severe foreign body reactions when covering wounds in abdominal wall, back muscle, tibia bone, and liver. In addition, the DAM-POC scaffold was superior to the DAM scaffold in reducing inflammation, preventing fibrosis, and regenerating tissues. In conclusion, the DAM-POC scaffold might potentially be adopted as a film dressing in a wide range of therapeutic applications and healing situations to protect the damaged tissues from the external environment and prevent infections.

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

BACKGROUND

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.

METHOD

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.

RESULTS

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.

CONCLUSION

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.

Fluid and pharmacological agents for adhesion prevention after gynaecological surgery

BACKGROUND

Adhesions are fibrin bands that are a common consequence of gynaecological surgery. They are caused by conditions that include pelvic inflammatory disease and endometriosis. Adhesions are associated with comorbidities, including pelvic pain, subfertility, and small bowel obstruction. Adhesions also increase the likelihood of further surgery, causing distress and unnecessary expenses. Strategies to prevent adhesion formation include the use of fluid (also called hydroflotation) and gel agents, which aim to prevent healing tissues from touching one another, or drugs, aimed to change an aspect of the healing process, to make adhesions less likely to form.

OBJECTIVES

To evaluate the effectiveness and safety of fluid and pharmacological agents on rates of pain, live births, and adhesion prevention in women undergoing gynaecological surgery.

SEARCH METHODS

We searched: the Cochrane Gynaecology and Fertility Specialised Register, CENTRAL, MEDLINE, Embase, PsycINFO, and Epistemonikos to 22 August 2019. We also checked the reference lists of relevant papers and contacted experts in the field.

SELECTION CRITERIA

Randomised controlled trials investigating the use of fluid (including gel) and pharmacological agents to prevent adhesions after gynaecological surgery.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures recommended by Cochrane. We assessed the overall quality of the evidence using GRADE methods. Outcomes of interest were pelvic pain; live birth rates; incidence of, mean, and changes in adhesion scores at second look-laparoscopy (SLL); clinical pregnancy, miscarriage, and ectopic pregnancy rates; quality of life at SLL; and adverse events.

MAIN RESULTS

We included 32 trials (3492 women), and excluded 11. We were unable to include data from nine studies in the statistical analyses, but the findings of these studies were broadly in keeping with the findings of the meta-analyses. Hydroflotation agents versus no hydroflotation agents (10 RCTs) We are uncertain whether hydroflotation agents affected pelvic pain (odds ratio (OR) 1.05, 95% confidence interval (CI) 0.52 to 2.09; one study, 226 women; very low-quality evidence). It is unclear whether hydroflotation agents affected live birth rates (OR 0.67, 95% CI 0.29 to 1.58; two studies, 208 women; low-quality evidence) compared with no treatment. Hydroflotation agents reduced the incidence of adhesions at SLL when compared with no treatment (OR 0.34, 95% CI 0.22 to 0.55, four studies, 566 women; high-quality evidence). The evidence suggests that in women with an 84% chance of having adhesions at SLL with no treatment, using hydroflotation agents would result in 54% to 75% having adhesions. Hydroflotation agents probably made little or no difference to mean adhesion score at SLL (standardised mean difference (SMD) -0.06, 95% CI -0.20 to 0.09; four studies, 722 women; moderate-quality evidence). It is unclear whether hydroflotation agents affected clinical pregnancy rate (OR 0.64, 95% CI 0.36 to 1.14; three studies, 310 women; moderate-quality evidence) compared with no treatment. This suggests that in women with a 26% chance of clinical pregnancy with no treatment, using hydroflotation agents would result in a clinical pregnancy rate of 11% to 28%. No studies reported any adverse events attributable to the intervention. Gel agents versus no treatment (12 RCTs) No studies in this comparison reported pelvic pain or live birth rate. Gel agents reduced the incidence of adhesions at SLL compared with no treatment (OR 0.26, 95% CI 0.12 to 0.57; five studies, 147 women; high-quality evidence). This suggests that in women with an 84% chance of having adhesions at SLL with no treatment, the use of gel agents would result in 39% to 75% having adhesions. It is unclear whether gel agents affected mean adhesion scores at SLL (SMD -0.50, 95% CI -1.09 to 0.09; four studies, 159 women; moderate-quality evidence), or clinical pregnancy rate (OR 0.20, 95% CI 0.02 to 2.02; one study, 30 women; low-quality evidence). No studies in this comparison reported on adverse events attributable to the intervention. Gel agents versus hydroflotation agents when used as an instillant (3 RCTs) No studies in this comparison reported pelvic pain, live birth rate or clinical pregnancy rate. Gel agents probably reduce the incidence of adhesions at SLL when compared with hydroflotation agents (OR 0.50, 95% CI 0.31 to 0.83; three studies, 538 women; moderate-quality evidence). This suggests that in women with a 46% chance of having adhesions at SLL with a hydroflotation agent, the use of gel agents would result in 21% to 41% having adhesions. We are uncertain whether gel agents improved mean adhesion scores at SLL when compared with hydroflotation agents (MD -0.79, 95% CI -0.82 to -0.76; one study, 77 women; very low-quality evidence). No studies in this comparison reported on adverse events attributable to the intervention. Steroids (any route) versus no steroids (4 RCTs) No studies in this comparison reported pelvic pain, incidence of adhesions at SLL or mean adhesion score at SLL. It is unclear whether steroids affected live birth rates compared with no steroids (OR 0.65, 95% CI 0.26 to 1.62; two studies, 223 women; low-quality evidence), or clinical pregnancy rates (OR 1.01, 95% CI 0.66 to 1.55; three studies, 410 women; low-quality evidence). No studies in this comparison reported on adverse events attributable to the intervention.

AUTHORS' CONCLUSIONS

Gels and hydroflotation agents appear to be effective adhesion prevention agents for use during gynaecological surgery, but we found no evidence indicating that they improve fertility outcomes or pelvic pain, and further research is required in this area. It is also worth noting that for some comparisons, wide confidence intervals crossing the line of no effect meant that clinical harm as a result of interventions could not be excluded. Future studies should measure outcomes in a uniform manner, using the modified American Fertility Society score. Statistical findings should be reported in full. No studies reported any adverse events attributable to intervention.

Evidence according to Cochrane Systematic Reviews on Alterable Risk Factors for Anastomotic Leakage in Colorectal Surgery

Anastomotic leakage reflects a major problem in visceral surgery, leading to increased morbidity, mortality, and costs. This review is aimed at evaluating and summarizing risk factors for colorectal anastomotic leakage. A generalized discussion first introduces risk factors beginning with nonalterable factors. Focus is then brought to alterable impact factors on colorectal anastomoses, utilizing Cochrane systematic reviews assessed via systemic literature search of the Cochrane Central Register of Controlled Trials and Medline until May 2019. Seventeen meta-anaylses covering 20 factors were identified. Thereof, 7 factors were preoperative, 10 intraoperative, and 3 postoperative. Three factors significantly reduced the incidence of anastomotic leaks: high (versus low) surgeon's operative volume (RR = 0.68), stapled (versus handsewn) ileocolic anastomosis (RR = 0.41), and a diverting ostomy in anterior resection for rectal carcinoma (RR = 0.32). Discussion of all alterable factors is made in the setting of the pre-, intra-, and postoperative influencers, with the only significant preoperative risk modifier being a high colorectal volume surgeon and the only significant intraoperative factors being utilizing staples in ileocolic anastomoses and a diverting ostomy in rectal anastomoses. There were no measured postoperative alterable factors affecting anastomotic integrity.

Application of hyaluronic acid/carboxymethyl cellulose membrane for early continence after nerve-sparing robot-assisted radical prostatectomy

Background

To assess whether application of a hyaluronic acid-carboxymethyl cellulose membrane (HA/CMC) to the prostate bed and neurovascular plate facilitated early return of continence after nerve-sparing robot-assisted radical prostatectomy (RARP).

Methods

The subjects were 183 consecutive patients with organ-confined prostate cancer who underwent unilateral or bilateral nerve-sparing RARP. After vesicourethral anastomosis, HA/CMC was placed to cover Denonvilliers’ fascia (behind the anastomotic suture) and the preserved neurovascular plate. The time until complete continence after RARP and perioperative complications were compared between patients with or without HA/CMC.

Results

HA/CMC was applied in 13/46 patients (28.3%) receiving bilateral nerve-sparing surgery and 40/137 patients (29.2%) receiving unilateral nerve-sparing surgery. After bilateral nerve-sparing RARP, the median time until continence was significantly shorter in patients with HA/CMC than in those without HA/CMC (3.2 vs. 9.3 months, respectively, p < 0.01). After unilateral nerve-sparing RARP, the median time until continence was also significantly shorter in patients with HA/CMC than in those without HA/CMC (3.2 vs. 12.0 months, respectively, p < 0.01). Multivariate Cox proportional hazards regression analysis showed that an age < 70 years (hazard ratio [HR]: 1.74, 95% confidence interval [CI]: 1.12–2.80), institutional caseload > 200, (HR: 1.64, 95%CI: 1.10–2.47), and use of HA/CMC (HR: 1.84, 95%CI: 1.22–2.76) were independent predictors of early postoperative continence. Complication rates, including urinary leakage, did not differ significantly between patients with or without HA/CMC.

Conclusion

Application of HA/CMC to the prostate bed and neurovascular plate resulted in significantly faster postoperative return of continence after both unilateral and bilateral nerve-sparing RARP.

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%.

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.

Active agents, biomaterials, and technologies to improve biolubrication and strengthen soft tissues

Normal functioning of articulating tissues is required for many physiological processes occurring across length scales from the molecular to whole organism. Lubricating biopolymers are present natively on tissue surfaces at various sites of biological articulation, including eyelid, mouth, and synovial joints. The range of operating conditions at these disparate interfaces yields a variety of tribological mechanisms through which compressive and shear forces are dissipated to protect tissues from material wear and fatigue. This review focuses on recent advances in active agents and biomaterials for therapeutic augmentation of friction, lubrication, and wear in disease and injured states. Various small-molecule, biological, and gene delivery therapies are described, as are tribosupplementation with naturally-occurring and synthetic biolubricants and polymer reinforcements. While reintroduction of a diseased tissue's native lubricant received significant attention in the past, recent discoveries and pre-clinical research are capitalizing on concurrent advances in the molecular sciences and bioengineering fields, with an understanding of the underlying tissue structure and physiology, to afford a desired, and potentially patient-specific, tissue mechanical response for restoration of normal function. Small and large molecule drugs targeting recently elucidated pathways as well as synthetic and hybrid natural/synthetic biomaterials for restoring a desired tissue mechanical response are being investigated for treatment of, for example, keratoconjunctivitis sicca, xeroderma, and osteoarthritis.

Barriers to Epineural Scarring: Role in Treatment of Traumatic Nerve Injury and Chronic Compressive Neuropathy

The physiological limitations of neural regeneration make peripheral nerve surgery challenging to both the surgeon and the patient. Presence of nerve gaps and local wound factors may all influence outcome, suggesting that barriers to reduce perineural scarring, minimize fibrosis, and avoid ischemia would be beneficial. To examine the evidence supporting their use, we reviewed the autologous and commercially-available options for barriers against scarring around a nerve. Numerous clinical case series demonstrated the effectiveness and safety of local/rotational flaps and autologous vein wrapping when used in the presence of recurrent compressive neuropathy. Translational research in animal models supports the biocompatibility of commercially available nerve wraps following nerve repair. To date, there are no reports of clinical use of commercially available nerve wraps in acute nerve repair, but a growing number of case series demonstrate their effectiveness and safety in chronic compressive neuropathy. Limited clinical evidence exists to support the efficacy of vein or flap coverage in acute nerve repairs.

Sutures impregnated with carbazate-activated polyvinyl alcohol reduce intraperitoneal adhesions

BACKGROUND

Intraperitoneal adhesions cause significant morbidity. They occur after peritoneal trauma, which induces oxidative stress with production of inflammatory cytokines, peroxidized proteins (carbonyls) and lipids (aldehydes). This study aimed to investigate if carbazate-activated polyvinyl alcohol (PVAC), an aldehyde-carbonyl inhibitor, can reduce intraperitoneal adhesions in an experimental model.

MATERIAL AND METHODS

Male Sprague-Dawley rats (n=110) underwent laparotomy, cecal abrasion and construction of a small bowel anastomosis. They either were treated with intraperitoneal instillation of PVAC or were sutured with PVAC-impregnated sutures. Thromboelastography analysis was performed using human blood and PVAC. The lipid peroxidation product malondialdehyde (MDA) and inflammatory cytokines IL-1β and IL-6 were quantified in peritoneal fluid. At day 7, bursting pressure of the anastomosis was measured and adhesions were blindly scored.

RESULTS

PVAC in human blood decreased the production of the fibrin-thrombocyte mesh without affecting the coagulation cascade. MDA, IL-1β and IL-6 were increased after 6h without significant difference between the groups. PVAC-impregnated sutures reduced intraperitoneal adhesions compared to controls (p=0.0406) while intraperitoneal instillation of PVAC had no effect. Anastomotic bursting pressure was unchanged.

CONCLUSIONS

Intervention with an aldehyde-carbonyl inhibitor locally in the wound by PVAC-impregnated sutures might be a new strategy to reduce intraperitoneal adhesions.

Paeoniflorin prevents postoperative peritoneal adhesion formation in an experimental rat model

Although materials and modern surgical techniques have been developed to suppress postoperative adhesions, adhesion formation can still occur, and thus, a novel effective anti-adhesion drug is greatly needed. In the present study, we explored the efficacy of paeoniflorin treatment against postoperative peritoneal adhesions and examined the anti-oxidative stress and anti-inflammatory properties of PE. Forty-eight male Sprague-Dawley rats were randomly divided into 6 groups for the study: the sham, control, hyaluronan and three concentrations (10, 20 and 40 mg/kg/d) paeoniflorin groups. Abdominal adhesions were created by abrasion of the caecum and its opposite abdominal wall. In the paeoniflorin groups, the rats were administered daily oral doses of paeoniflorin for 7 days. The abdominal cavities of the rats were reopened with a U-shaped incision to macroscopically grade the adhesions. Histologic analysis was performed, and oxidative stress, inflammatory cytokine, collagen fiber degradation and cytokeratin levels were measured. Macroscopic and histopathological measurements revealed that paeoniflorin reduced peritoneal adhesion and inflammation. Notably, treatment with paeoniflorin reduced the protein levels of TGF-β1, IL-6 and COX-2. The collagen fiber fractions were distinctly lower in the PE groups than in the control group. Western blotting analyses showed that paeoniflorin increased MMP-9 and superoxide dismutase-2 protein expression and sharply reduced α-SMA and COX-2 protein expression. Peritoneal mesothelium cells were more continuous and complete in animals treated with paeoniflorin. Our study suggests that paeoniflorin can be used to ameliorate peritoneal adhesions via anti-oxidative stress and anti-inflammatory actions during the postoperative period.

Attenuation of postoperative adhesions using a modeled manual therapy

Postoperative adhesions are pathological attachments that develop between abdominopelvic structures following surgery. Considered unavoidable and ubiquitous, postoperative adhesions lead to bowel obstructions, infertility, pain, and reoperations. As such, they represent a substantial health care challenge. Despite over a century of research, no preventive treatment exists. We hypothesized that postoperative adhesions develop from a lack of movement of the abdominopelvic organs in the immediate postoperative period while rendered immobile by surgery and opiates, and tested whether manual therapy would prevent their development. In a modified rat cecal abrasion model, rats were allocated to receive treatment with manual therapy or not, and their resulting adhesions were quantified. We also characterized macrophage phenotype. In separate experiments we tested the safety of the treatment on a strictureplasty model, and also the efficacy of the treatment following adhesiolysis. We show that the treatment led to reduced frequency and size of cohesive adhesions, but not other types of adhesions, such as those involving intraperitoneal fatty structures. This effect was associated with a delay in the appearance of trophic macrophages. The treatment did not inhibit healing or induce undesirable complications following strictureplasty. Our results support that that maintained movements of damaged structures in the immediate postoperative period has potential to act as an effective preventive for attenuating cohesive postoperative adhesion development. Our findings lay the groundwork for further research, including mechanical and pharmacologic approaches to maintain movements during healing.

Laparoscopic Surgery is Useful for Preventing Recurrence of Small Bowel Obstruction After Surgery for Postoperative Small Bowel Obstruction

INTRODUCTION

Risk factors for recurrence postoperative small bowel obstruction in patients who have postoperative abdominal surgery remain unclear.

MATERIALS AND METHODS

The study group comprised 123 patients who underwent surgery for ileus that developed after abdominal surgery from 1999 through 2013. There were 58 men (47%) and 65 women (53%), with a mean age of 63 years (range, 17 to 92 y). The following surgical procedures were performed: lower gastrointestinal surgery in 47 patients (39%), gynecologic surgery in 39 (32%), upper gastrointestinal surgery in 15 (12%), appendectomy in 9 (7%), cholecystectomy in 5 (4%), urologic surgery in 5 (4%), and repair of injuries caused by traffic accidents in 3 (2%). Laparoscopic surgery was performed in 75 patients (61%), and open surgery was done in 48 (39%). We examined the following 11 potential risk factors for recurrence of small bowel obstruction after surgery for ileus: sex, age, body mass index, the number of episodes of ileus, the number of previously performed operations, the presence or absence of radiotherapy, the previously used surgical technique, the current surgical technique (laparoscopic surgery, open surgery), operation time, bleeding volume, and the presence or absence of enterectomy.

RESULTS

The median follow-up was 57 months (range, 7 to 185 mo). Laparoscopic surgery was switched to open surgery in 11 patients (18%). The reason for surgery for postoperative small bowel obstruction was adhesion to the midline incision in 36 patients (29%), band formation in 30 (24%), intrapelvic adhesion in 23 (19%), internal hernia in 13 (11%), small bowel adhesion in 20 (16%), and others in 1 (1%). Postoperative complications developed in 35 patients (28%): wound infection in 12 (10%), recurrence of postoperative small bowel obstruction in 12 (10%), paralytic ileus in 4 (3%), intra-abdominal abscess in 3 (2%), suture failure in 1 (1%), anastomotic bleeding in 1 (1%), enteritis in 1 (1%), and dysuria in 1 (1%). Enterectomy was performed in 42 patients (38%). On univariate analysis, 2 risk factors were significantly related to the recurrence of small bowel obstruction: open surgery (P=0.017) and bleeding volume (P=0.031). On multivariate analysis, open surgery was an independent risk factor for the recurrence of small bowel obstruction (odds ratio, 5.621; P=0.015).

CONCLUSIONS

Open surgery was an independent risk factor for the recurrence of small bowel obstruction after abdominal surgery. In the future, laparoscopic surgery should be performed to prevent the recurrence of small bowel obstruction.

Comparison of the effects of Mitomycin-C and sodium hyaluronate/carboxymethylcellulose [NH/CMC] (Seprafilm) on abdominal adhesions

Introduction

Intra-abdominal adhesions (IA) may occur after abdominal surgery and also may lead to complications such as infertility, intestinal obstruction and chronic pain. The aim of this study was to compare the effects of Mitomycin-C (MM-C) and sodium hyaluronate/carboxymethylcellulose [NH/CMC] on abdominal adhesions in a cecal abrasion model and to investigate the toxicity of MM-C on complete blood count (CBC) and bone marrow analyses.

Methods

The study comprised forty rats in four groups (Control, Sham, Cecal abrasion + MM-C, and Cecal abrasion + NH/CMC). On postoperative day 21, all rats except for the control (CBC + femur resection) group, were sacrificed. Macroscopical and histopathological evaluations of abdominal adhesions were performed. In order to elucidate the side effects of MM-C; CBC analyses and femur resections were performed to examine bone marrow cellularity.

Results

CBC analyses and bone marrow cellularity assessment revealed no statistically significant differences between MM-C, NH/CMC and control groups. No significant differences in inflammation scores were observed between the groups. The MM-C group had significantly lower fibrosis scores compared to the NH/CMC and sham groups. Although the adhesion scores were lower in the MM-C group, the differences were not statistically significant.

Conclusion

Despite its potential for systemic toxicity, MM-C may show some anti-fibrosis and anti-adhesive effects. MM-C is a promising agent for the prevention of IAs, and as such, further trials are warranted to study efficacy.

Standard Biocompatibility Studies Do Not Predict All Effects of PVA/CMC Anti-Adhesive Gel in vivo

Purpose: PVA/CMC (polyvinyl alcohol/carboxymethyl cellulose) hydrogel fulfills various physiochemical properties required for an adhesion barrier and has shown good anti-adhesion properties in previous in vivo studies. In this investigation, we assessed the in vitro and in vivo biocompatibility of PVA/CMC gel and compared this to the functionality and promotion of wound healing for two surgical indications. Methods: Standardized ISO10993 in vitro and in vivo biocompatibility studies, comprising cytotoxicity, genotoxicity, acute systemic toxicity, delayed contact and maximization sensitization test, intracutaneous reactivity and local muscle implantation, were performed on PVA/CMC gel. In the functional studies, PVA/CMC gel was applied - on the one hand - to a rabbit abdominal wall model enforced with a polypropylene mesh for testing the anti-adhesion properties and - on the other hand - to an end- to-end anastomosis model that was selected for surveying potential influences of different dosages of PVA/CMC gel on anastomotic wound healing. Results: The ISO10993 methods indicated generally good biocompatibility properties, such as the absence of cytotoxic and mutagenic effects as well as no signs of systemic toxicity and sensitization potentials. No irritation effects were observed after the intracutaneous injection of lipophilic PVA/CMC sesame oil extract. However, the injection of hydrophilic PVA/CMC physiologic saline extract induced slight irritation. Following rabbit muscle implantation of the PVA membrane for 2, 4, 12, 26 and 52 weeks, a slight irritant effect was observed at 12 weeks due to the peak of phagocytosis. In the functionality tests, PVA/CMC gel showed good anti-adhesive effects in the abdominal wall model enforced with the mesh, with significantly lower and less tense adhesions compared to the untreated control. However, moderate signs of inflammation, especially in the spleen were observed after the intra-abdominal implantation of 3.3 ml PVA/CMC gel per kg body weight. In the end-to-end anastomosis model, PVA/CMC gel had no influence on wound healing. For dosages of 1-6 ml gel per treatment, no signs of intestinal leaks were detected, and tensile strength was equal to that of the untreated control, but again more moderate signs of inflammation in the spleen were observed at a dosage >3 ml. Conclusion: Comparing the standardized ISO10993 methods, anti-adhesive PVA/CMC gel displays good biocompatibility. However, those methods do not seem to be sensitive enough because the rabbit abdominal wall and the end-to-end anastomosis models display more effects with respect to the dosage and routes of the intra-abdominal resorption of PVA/CMC gel - with the recommended <2 ml PVA/CMC gel per kg body weight as a secure dosage.

[Peritoneal adhesion formation]

Postoperative peritoneal adhesions are common sequelae of abdominal surgery. Acute as well as chronic complications, including bowel obstruction, abdominal pain and infertility can arise from adhesion formation. So far, the only reliable treatment is surgical adhesiolysis, which in turn is accompanied by an increased risk of adhesion recurrence. Despite significant progress in modern perioperative medicine, only limited prophylactic approaches are available and atraumatic surgery is still the most important factor.Current research concepts focus on two major antiadhesion strategies: firstly, the intraoperative placement of mechanical barriers and secondly novel immunomodulation concepts. Clinical data about the use of antiadhesive barriers show a heterogeneous outcome. Promising data have arisen from the immunomodulatory approaches and now require a step-up development from experimental to clinical trial level.The present review gives a short overview about the current research on the pathophysiology and prevention of peritoneal adhesions. The promising data are encouraging and require realization of carefully designed prospective clinical trials.

Application of a hyaluronic acid gel after intrauterine surgery may improve spontaneous fertility: a randomized controlled trial in New Zealand White rabbits

Objective

Intrauterine adhesions (IUAs) are the most common complication after hysteroscopy in patients of reproductive age. Intra-abdominal anti-adhesion gel reduces the incidence of adhesions, but effects on fertility after uterine surgery are not known. The objective of our work was to evaluate the effect of intrauterine anti-adhesion gel on spontaneous fertility after repeated intrauterine surgery with induced experimental synechiae in the rabbit model.

Materials and Methods

Twenty New Zealand White rabbits underwent a double uterine curettage 10 days apart and were randomized into two groups. Each rabbit served as its own control: one uterine tube was the treatment group (A), the second uterine tube was the control group (B) to avoid bias through other causes of infertility. Group A received a post curettage intrauterine instillation of anti-adhesion gel whereas group B, the control group, underwent curettage without instillation of the gel. After a recovery period, the rabbits were mated. An abdominal ultrasound performed 21 days after mating allowed us to diagnose pregnancy and quantify the number of viable fetuses.

Results

There was a significant difference in total fetuses in favor of group A, with an average of 3.7 (range, 0–9) total fetuses per tube against 2.1 (0–7) in group B (p = .04). The number of viable fetuses shows a trend in favor of group A, with an average of 3.4 (0–7) viable fetuses per tube against 1.9 (0–6) viable fetuses per tube in group B (p = .05).

Conclusion

The use of immediate postoperative anti-adhesion gel improved fertility in an animal model after intrauterine surgery likely to cause uterine synechiae. This experimental model will permit comparison of different anti-adhesion solutions, including assessment of their tolerance and potential mucosal toxicity on embryonic development.

Cell-based therapy for preventing postoperative adhesion and promoting regeneration after hepatectomy

Postoperative adhesion is a critical clinical issue after almost all abdominal or pelvic surgeries including liver surgery. Postoperative adhesion causes several complications, such as small bowel obstruction and chronic abdominal pain. Furthermore, it makes reoperation much more difficult, leading to increased mortality and morbidity rate. Postoperative adhesion is particularly problematic for repeated hepatectomy, since hepatic malignant neoplasm recurs frequently and repeated hepatectomy is widely used as one of the most curative treatments. Several treatments to reduce postoperative adhesion have been developed, which include laparoscopic surgery, administration of pharmacological agents and use of prophylactic barrier materials. However, none of them are optimal. We have proposed a novel treatment using a cell sheet of fetal liver mesothelial cells (FL-MCs) to prevent postoperative adhesion in a novel mouse model. Besides adhesion, repeated hepatectomy has another serious problem; although the liver has a remarkable ability to regenerate, the recovery of liver mass and function of the remnant liver after multiple repeated hepatectomy is limited. The FL-MC cell sheet enhances proliferation of hepatocytes after hepatectomy by providing growth factors for hepatocytes. Thus the FL-MC sheet could simultaneously solve the two problems associated with repeated hepatectomy.

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.

Efficacy and safety of the C-Qur™ Film Adhesion Barrier for the prevention of surgical adhesions (CLIPEUS Trial): study protocol for a randomized controlled trial

BACKGROUND

Adhesions develop in over 90% of patients after intra-abdominal surgery. Adhesion barriers are rarely used despite the high morbidity caused by intra-abdominal adhesions. Only one of the currently available adhesion barriers has demonstrated consistent evidence for reducing adhesions in visceral surgery. This agent has limitations through poor handling characteristics because it is sticky on both sides. C-Qur™ Film is a novel thin film adhesion barrier and it is sticky on only one side, resulting in better handling characteristics. The objective of this study is to assess efficacy and safety of C-Qur™ Film to decrease the incidence of adhesions after colorectal surgery.

METHODS/DESIGN

This is a prospective, investigator initiated, randomized, double-blinded, multicenter trial. Eligible patients undergoing colorectal resection requiring temporary loop ileostomy or loop/split colostomy by laparotomy or hand assisted laparoscopy will be included in the trial. Before closure, patients are randomized 1:1 to either the treatment arm (C-Qur™ Film) or control arm (no adhesion barrier). Patients will return 8 to 16 weeks post-colorectal resection for take down of their ostomy. During ostomy takedown, adhesions will be evaluated for incidence, extent, and severity. The primary outcome evaluation will be assessment of adhesions to the incision site. It is hypothesized that the use of C-Qur™ Film underneath the primary incision reduces the incidence of adhesion at the incision by 30%. To demonstrate 30% reduction in the incidence of adhesions, a sample size of 84 patients (32 + 10 per group (25% drop out)) is required (two-sided test, α = 0.05, 80% power).

DISCUSSION

Results of this study add to the evidence on the use of anti-adhesive barriers in open and laparoscopic 'hand-assisted' colorectal surgery. We chose incidence of adhesions to the incision site as primary outcome measure since clinical outcomes such as small bowel obstruction, secondary infertility and adhesiolysis related complications are considered multifactorial and difficult to interpret. Incidence of adhesions at repeat surgery is believed to be the most valuable surrogate endpoint for clinically relevant adhesion prevention, since small bowel obstruction and adhesiolysis at repeat surgery are not likely to occur when complete adhesion reduction in a patient is accomplished.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier NCT01872650, registration date 6 June 2013.

Fluid and pharmacological agents for adhesion prevention after gynaecological surgery

BACKGROUND

Adhesions are fibrin bands that are a common consequence of gynaecological surgery. They are caused by various conditions including pelvic inflammatory disease and endometriosis. Adhesions are associated with considerable co-morbidity, including pelvic pain, subfertility and small bowel obstruction. Patients may require further surgery-a fact that has financial implications.

OBJECTIVES

To evaluate the role of fluid and pharmacological agents used as adjuvants in preventing formation of adhesions after gynaecological surgery.

SEARCH METHODS

The following databases were searched up to April 2014: Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, Cumulative Index to Nursing and Allied Health Literature (CINAHL) and PsycINFO. Studies involving hydroflotation, gel and such pharmacological agents as steroids, noxytioline, heparin, promethazine, N,O-carboxymethyl chitosan and gonadotrophin-releasing hormone agonists were evaluated.

SELECTION CRITERIA

Randomised controlled trials investigating the use of fluid and pharmacological agents to prevent adhesions after gynaecological surgery. Gels were defined as fluid agents.

DATA COLLECTION AND ANALYSIS

Three review authors independently assessed trials for eligibility, extracted data and evaluated risk of bias. Results were expressed as odds ratios (ORs), mean differences (MDs) or standard mean differences (SMDs) as appropriate, with 95% confidence intervals (CIs).

MAIN RESULTS

Twenty-nine trials were included (3227 participants), and nine were excluded. One study examined pelvic pain and found no evidence of a difference between use of hydroflotation agents and no treatment. We found no evidence that any of the antiadhesion agents significantly affected the live birth rate. When gels were compared with no treatment or with hydroflotation agents at second-look laparoscopy (SLL), fewer participants who received a gel showed a worsening adhesion score when compared with those who received no treatment (OR 0.16, 95% CI 0.04 to 0.57, P value 0.005, two studies, 58 women, I(2) = 0%, moderate-quality evidence) and with those given hydroflotation agents (OR 0.28, 95% CI 0.12 to 0.66, P value 0.003, two studies, 342 women, I(2) = 0%, high-quality evidence). Participants who received steroids were less likely to have a worsening adhesion score (OR 0.27, 95% CI 0.12 to 0.58, P value 0.0008, two studies, 182 women, I(2) = 0%, low-quality evidence). Participants were less likely to have adhesions at SLL if they received a hydroflotation agent or gel than if they received no treatment (OR 0.34, 95% CI 0.22 to 0.55, P value < 0.00001, four studies, 566 participants, I(2) = 0%, high-quality evidence; OR 0.25, 95% CI 0.11 to 0.56, P value 0.0006, four studies, 134 women, I(2) = 0%, high-quality evidence, respectively). When gels were compared with hydroflotation agents, participants who received a gel were less likely to have adhesions at SLL than those who received a hydroflotation agent (OR 0.36, 95% CI 0.19 to 0.67, P value 0.001, two studies, 342 women, I(2) = 0%, high-quality evidence). No studies evaluated quality of life. In all studies apart from one, investigators stated that they were going to assess serious adverse outcomes associated with treatment agents, and no adverse effects were reported.Results suggest that for a woman with a 77% risk of developing adhesions without treatment, the risk of developing adhesions after use of a gel would be between 26% and 65%. For a woman with an 83% risk of worsening of adhesions after no treatment at initial surgery, the chance when a gel is used would be between 16% and 73%. Similarly, for hydroflotation fluids for a woman with an 84% chance of developing adhesions with no treatment, the risk of developing adhesions when hydroflotation fluid is used would be between 53% and 73%.Several of the included studies could not be included in a meta-analysis: The findings of these studies broadly agreed with the findings of the meta-analyses.The quality of the evidence, which was assessed using the GRADE approach, ranged from low to high. The main reasons for downgrading of evidence included imprecision (small sample sizes and wide confidence intervals) and poor reporting of study methods.

AUTHORS' CONCLUSIONS

Gels and hydroflotation agents appear to be effective adhesion prevention agents for use during gynaecological surgery, but no evidence indicates that they improve fertility outcomes or pelvic pain, and further research is required in this area. Future studies should measure outcomes in a uniform manner, using the modified American Fertility Society (mAFS) score. Statistical findings should be reported in full.

Da-cheng-qi decoction, a traditional Chinese herbal formula, for intestinal obstruction: systematic review and meta-analysis

BACKGROUND

This study was aimed at determining the effects and safety of Da-Cheng-Qi decoction (DCQD) or DCQD combined with conservative therapy in patients with intestinal obstruction.

MATERIALS AND METHODS

PubMed, EMBASE, Cochrane Controlled Trials Register, and several other databases were searched. Randomised controlled trials (RCTs) of DCQD or DCQD plus conservative therapy in patients with intestinal obstruction were eligible. Therapeutic effect was estimated by the improvement of clinical manifestations and diagnostic imaging; dichotomous/ordinal data assessment of overall response to therapy, adverse effects; or continuous variable were identified, including time to first bowel movement, time to first flatus, length of hospital stay.

RESULTS

Sixty eligible RCTs including 6,095 patients were identified. Response rate: (1) DCQD versus conservative therapy (6 RCTs, 361 patients, RR of respond =1.13; 95% CI 0.97 to 1.31). (2) DCQD plus conservative therapy versus conservative therapy (48 RCTs, 4,916 patients, RR of respond =1.25 which favoured DCQD plus conservative therapy; 95% CI 1.20 to 1.30). Treatment effect remained similar when RCTs at high risk of bias were excluded. Time to first flatus postoperatively: (1) DCQD versus conservative therapy (2 RCTs, 240 patients, SMD=-3.65; 95% CI -8.17 to 0.87). (2) DCQD plus conservative therapy versus conservative therapy (11 RCTs, 1,040 patients, SMD=-2.09 which favoured DCQD plus conservative therapy; 95% CI -3.04 to -1.15).

CONCLUSION

DCQD combined with conservative therapy may increase the success rate of conservative therapy for intestinal obstruction significantly and can shorten the duration of postoperative ileus in patients undergoing abdominal surgery compared with conservative therapy alone.

Benefits and harms of adhesion barriers for abdominal surgery: a systematic review and meta-analysis

BACKGROUND

Formation of adhesions after peritoneal surgery results in high morbidity. Barriers to prevent adhesion are seldom applied, despite their ability to reduce the severity of adhesion formation. We evaluated the benefits and harms of four adhesion barriers that have been approved for clinical use.

METHODS

In this systematic review and meta-analysis, we searched PubMed, CENTRAL, and Embase for randomised clinical trials assessing use of oxidised regenerated cellulose, hyaluronate carboxymethylcellulose, icodextrin, or polyethylene glycol in abdominal surgery. Two researchers independently identified reports and extracted data. We compared use of a barrier with no barrier for nine predefined outcomes, graded for clinical relevance. The primary outcome was reoperation for adhesive small bowel obstruction. We assessed systematic error, random error, and design error with the error matrix approach. This study is registered with PROSPERO, number CRD42012003321.

FINDINGS

Our search returned 1840 results, from which 28 trials (5191 patients) were included in our meta-analysis. The risks of systematic and random errors were low. No trials reported data for the effect of oxidised regenerated cellulose or polyethylene glycol on reoperations for adhesive small bowel obstruction. Oxidised regenerated cellulose reduced the incidence of adhesions (relative risk [RR] 0·51, 95% CI 0·31-0·86). Some evidence suggests that hyaluronate carboxymethylcellulose reduces the incidence of reoperations for adhesive small bowel obstruction (RR 0·49, 95% CI 0·28-0·88). For icodextrin, reoperation for adhesive small bowel obstruction did not differ significantly between groups (RR 0·33, 95% CI 0·03-3·11). No barriers were associated with an increase in serious adverse events.

INTERPRETATION

Oxidised regenerated cellulose and hyaluronate carboxymethylcellulose can safely reduce clinically relevant consequences of adhesions.

FUNDING

None.

Bologna guidelines for diagnosis and management of adhesive small bowel obstruction (ASBO): 2013 update of the evidence-based guidelines from the world society of emergency surgery ASBO working group

Background

In 2013 Guidelines on diagnosis and management of ASBO have been revised and updated by the WSES Working Group on ASBO to develop current evidence-based algorithms and focus indications and safety of conservative treatment, timing of surgery and indications for laparoscopy.

Recommendations

In absence of signs of strangulation and history of persistent vomiting or combined CT-scan signs (free fluid, mesenteric edema, small-bowel feces sign, devascularization) patients with partial ASBO can be managed safely with NOM and tube decompression should be attempted. These patients are good candidates for Water-Soluble-Contrast-Medium (WSCM) with both diagnostic and therapeutic purposes. The radiologic appearance of WSCM in the colon within 24 hours from administration predicts resolution. WSCM maybe administered either orally or via NGT both immediately at admission or after failed conservative treatment for 48 hours. The use of WSCM is safe and reduces need for surgery, time to resolution and hospital stay.

NOM, in absence of signs of strangulation or peritonitis, can be prolonged up to 72 hours. After 72 hours of NOM without resolution, surgery is recommended.

Patients treated non-operatively have shorter hospital stay, but higher recurrence rate and shorter time to re-admission, although the risk of new surgically treated episodes of ASBO is unchanged. Risk factors for recurrences are age <40 years and matted adhesions. WSCM does not decrease recurrence rates or recurrences needing surgery.

Open surgery is often used for strangulating ASBO as well as after failed conservative management. In selected patients and with appropriate skills, laparoscopic approach is advisable using open access technique. Access in left upper quadrant or left flank is the safest and only completely obstructing adhesions should be identified and lysed with cold scissors. Laparoscopic adhesiolysis should be attempted preferably if first episode of SBO and/or anticipated single band. A low threshold for open conversion should be maintained.

Peritoneal adhesions should be prevented. Hyaluronic acid-carboxycellulose membrane and icodextrin decrease incidence of adhesions. Icodextrin may reduce the risk of re-obstruction. HA cannot reduce need of surgery.

Adhesions quantification and scoring maybe useful for achieving standardized assessment of adhesions severity and for further research in diagnosis and treatment of ASBO.

Burden of adhesions in abdominal and pelvic surgery: systematic review and met-analysis

OBJECTIVE

To estimate the disease burden of the most important complications of postoperative abdominal adhesions: small bowel obstruction, difficulties at reoperation, infertility, and chronic pain.

DESIGN

Systematic review and meta-analyses.

DATA SOURCES

Searches of PubMed, Embase, and Central, from January 1990 to December 2012, without restrictions to publication status or language.

STUDY SELECTION

All types of studies reporting on the incidence of adhesion related complications were considered.

DATA EXTRACTION AND ANALYSIS

The primary outcome was the incidence of adhesive small bowel obstruction in patients with a history of abdominal surgery. Secondary outcomes were the incidence of small bowel obstruction by any cause, difference in operative time, enterotomy during adhesiolysis, and pregnancy rate after abdominal surgery. Subgroup and sensitivity analyses were done to study the robustness of the results. A random effects model was used to account for heterogeneity between studies.

RESULTS

We identified 196 eligible papers. Heterogeneity was considerable for almost all meta-analyses. The origin of heterogeneity could not be explained by study design, study quality, publication date, anatomical site of operation, or operative technique. The incidence of small bowel obstruction by any cause after abdominal surgery was 9% (95% confidence interval 7% to 10%; I(2)=99%). the incidence of adhesive small bowel obstruction was 2% (2% to 3%; I(2)=93%); presence of adhesions was generally confirmed by emergent reoperation. In patients with a known cause of small bowel obstruction, adhesions were the single most common cause (56%, 49% to 64%; I(2)=96%). Operative time was prolonged by 15 minutes (95% confidence interval 9.3 to 21.1 minutes; I(2)=85%) in patients with previous surgery. Use of adhesiolysis resulted in a 6% (4% to 8%; I(2)=89%) incidence of iatrogenic bowel injury. The pregnancy rate after colorectal surgery in patients with inflammatory bowel disease was 50% (37% to 63%; I(2)=94%), which was significantly lower than the pregnancy rate in medically treated patients (82%, 70% to 94%; I(2)=97%).

CONCLUSIONS

This review provides detailed and systematically analysed knowledge of the disease burden of adhesions. Complications of postoperative adhesion formation are frequent, have a large negative effect on patients' health, and increase workload in clinical practice. The quantitative effects should be interpreted with caution owing to large heterogeneity.

REGISTRATION

The review protocol was registered through PROSPERO (CRD42012003180).

Influence of 4% icodextrin solution on peritoneal tissue response and adhesion formation

BACKGROUND

Postoperative peritoneal adhesion formation following abdominal surgery remains a relevant surgical problem. The application of soluble physico-chemical barriers like 4% icodextrin is one approach to protect the peritoneal surface from getting linked to adhesive scar. The aim of this study was to investigate the influence of 4% icodextrin on peritoneal tissue response both of visceral and parietal peritoneum, adhesion formation and wound healing.

METHODS

40 rats were divided into two groups. After creation of an intraabdominal defect, either 4% icodextrin (Adept®) or sodium chloride was applied. Animals were sacrificed after 7 and 21 days. Adhesions were scored by an adhesion score. Furthermore, immunohistochemical investigations were conducted to determine the discrete influence of icodextrin on the parietal and visceral peritoneal tissue responses (CD68+ macrophages, CD3+ T-lymphocytes, vimentin for mesenchymal cells, HBME-1 for mesothelial cells, and as components of wound healing COX-2, C-myc, catenin).

RESULTS

Postoperative peritoneal adhesions were predominantly present in the sodium chloride group as compared to the icodextrin group (14/19 (74%) vs. 9/19 (47%); p = 0.048). The adhesion score however did not reveal any significant differences, (p = 0.614). Furthermore, the expression of vimentin in both the parietal and visceral peritoneum after 21 days was significantly lower in the icodextrin group than in the sodium chloride group (p = 0.038 and p = 0.028, respectively). No significant differences were observed for macrophages, lymphocytes, reperitonealisation or the expression of COX-2, C-myc or Catenin.

CONCLUSIONS

The intraperitoneal application of 4% icodextrin reduces adhesion formation in comparison to sodium chloride. 4% icodextrin solution reduces the inflammatory and mesenchymal infiltrate in the wounded area, thus improving the ratio of mesothel cells to mesenchymal infiltrate. As demonstrated, icodextrin is able to ameliorate the local tissue response. Further experimental studies would be done to elaborate the impact on the early response of the adaptive immune system, which may then trigger the subsequent wound healing and tissue repair.

All the commercially available adhesion barriers have the same effect on adhesion prophylaxis?; A comparison of barrier agents using a newly developed, severe intra-abdominal adhesion model

BACKGROUND

Various types of adhesion barriers are widely used to prevent intra-abdominal adhesion. However, few studies have compared the efficacy of adhesion barriers using the same animal model. The aim of this study was to compare the anti-adhesive effects of various barrier agents using a newly developed, severe adhesion model.

METHODS

A severe adhesion model was established by excision of a 1-cm(2) intra-abdominal wall and application of cyanoacrylate in rat. Eighty male Sprague-Dawley rats (10 weeks old; 370 ± 50 g) were divided randomly into four groups (n = 20 each): the untreated control group, G-group using a hyaluronic acid and sodium carboxymethyl cellulose gel (Guardix-sol®), A-group using 4% icodextrin (Adept®), and S-group using a hyaluronate-carboxymethyl cellulose membrane (Seprafilm®). The effect of each adhesion barrier was evaluated by means of the extent and severity of adhesion, difficulty of adhesiolysis scoring systems, and microscopic grade of fibrosis.

RESULTS

The G-group showed no difference in adhesion score and fibrosis, the A-group demonstrated only a significantly lower fibrosis, and the S-group exhibited a significantly lower adhesion score and lower fibrosis compared with the control group. The S-group had a significantly lower adhesion score and reduced fibrosis compared with the G-group; however, no significant difference in adhesion score and fibrosis was noted with the A-group.

CONCLUSIONS

The membranous barrier Seprafilm® may be effective in the prevention of adhesion in the condition of peritoneal injury combined with foreign material. Adept® showed a tendency of decreasing the severity of adhesion and was effective in the prevention of fibrosis.

Adhesions after abdominal surgery: a systematic review of the incidence, distribution and severity

Abdominal adhesions are associated with increased postoperative complications, cost and workload. We performed a systematic review with statistical pooling to estimate the formation rate, distribution and severity of postoperative adhesions in patients undergoing abdominal surgery. A literature search was carried out for all articles reporting on the incidence, distribution and severity of adhesions between January 1990 and July 2011. Twenty-five articles fulfilled the inclusion criteria. The weighted mean formation rate of adhesions after abdominal surgery was 54 % (95 % confidence interval [CI] 40-68 %), and was 66 % (95 % CI 38-94 %) after gastrointestinal surgery, 51 % (95 % CI 40-63 %) after obstetric and gynaecological surgery and 22 % (95 % CI 7-38 %) after urological surgery. The mean overall severity score was 1.11 ± 0.98 according to the Operative Laparoscopy Study Group classification. Laparoscopic surgery reduced the adhesion formation rate by 25 % and decreased the adhesion severity score (laparoscopic; 0.36 ± 0.69 vs. open; 2.14 ± 0.84) for gastrointestinal surgery. Our results demonstrate that the incidence and severity of abdominal adhesions varies between surgical specialties and procedures. An increased awareness of adhesions can help in identifying the underlying mechanisms of adhesion formation and novel therapeutic approaches, while also improving the surgical consent process.

Hyaluronic acid derivatives and their healing effect on burns, epithelial surgical wounds, and chronic wounds: a systematic review and meta-analysis of randomized controlled trials

Hyaluronic acid (HA) is a polysaccharide common to most species and is found in many sites in the human body, including the skin and soft tissue. A systematic review of the literature and meta-analysis was performed to identify randomized controlled trials, evaluating the use of HA derivatives in healing burns, epithelial surgical, and chronic wounds. Nine studies were identified, which met the search criteria and clinical endpoints of complete healing and percent wound size reduction when using HA vs. either an active or passive comparator. It was found in the vast majority of randomized controlled trials (eight of nine) that HA derivatives significantly improved the healing of wounds vs. traditional therapies or placebo (either via complete healing or a significant reduction in wound size) occurring from burns, venous insufficiency, diabetes, neuropathic insufficiency, and surgical removal of the epithelial layer (for tattoo removal). In the other remaining trial, one formulation of HA was compared with another, with the higher concentration showing improved application characteristics. Further, it was found in a meta-analysis in subsets of patients with diabetic foot ulcers (neuropathic) that HA derivatives healed these types of wounds significantly faster than standard of care. These studies in aggregate show that HA derivatives accelerate the healing process in burns, epithelial surgical wounds, and chronic wounds.

Current strategies and future perspectives for intraperitoneal adhesion prevention

INTRODUCTION

The formation of peritoneal adhesions still is a relevant clinical problem after abdominal surgery. Until today, the most important clinical strategies for adhesion prevention are accurate surgical technique and the physical separation of traumatized serosal areas. Despite a variety of barriers which are available in clinical use, the optimal material has not yet been found.

DISCUSSION

Mesothelial cells play a crucial physiological role in friction less gliding of the serosa and the maintenance of anantiadhesive surface. The formation of postoperative adhesions results from a cascade of events and is regulated by various cellular and humoral factors. Therefore, optimization or functionalization of barrier materials by developments interacting with this cascade on a structural or pharmacological level could give an innovative input for future strategies in peritoneal adhesion prevention. For this purpose, the proper understanding of the formal pathogenesis of adhesion formation is essential. Based on the physiology of the serosa and the pathophysiology of adhesion formation, the available barriers in current clinical practice as well as new innovations are discussed in the present review.

Oral traditional Chinese medication for adhesive small bowel obstruction

BACKGROUND

Small bowel obstruction (SBO) is one of the most common emergent complications of general surgery. Intra-abdominal adhesions are the leading cause of SBO. Because surgery can induce new adhesions, non-operative management is preferred in the absence of signs of peritonitis or strangulation. Oral traditional Chinese herbal medicine has long been used as a non-operative therapy to treat adhesive SBO in China. Many controlled trials have been conducted to investigate its therapeutic value in resolving adhesive SBO.

OBJECTIVES

The aim of this review was to assess the efficacy and safety of oral traditional Chinese medicine (TCM) for adhesive small bowel obstruction.

SEARCH METHODS

We searched the following databases, without regard to language or publishing restrictions: the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, Chinese Biomedical Database (CBM), China National Knowledge Infrastructure/Chinese Academic Journals full-text Database (CNKI), and VIP (a full-text database of Chinese journals). The searches were conducted in November 2011.

SELECTION CRITERIA

Randomised controlled trials and quasi-randomised controlled trials comparing Chinese medicines administered orally, via the gastric canal, or both with a placebo or conventional therapy in participants diagnosed with adhesive SBO were considered. We also considered trials of TCM (oral administration, gastric tube perfusion, or both) plus conventional therapy compared with conventional therapy alone for patients with adhesive SBO. Studies addressing the safety and efficacy of oral traditional Chinese medicinal agents in the treatment of adhesive SBO were also considered.

DATA COLLECTION AND ANALYSIS

Two authors collected the data independently. We assessed the risk of bias according to the following methodological criteria: random sequence generation, allocation concealment, blinding, incomplete outcome data, selective outcome reporting and other sources of bias. Dichotomous data are presented as risk ratios (OR) and 95% confidence intervals (CI); continuous outcomes are presented as mean differences (MD) and 95% CIs. The data analyses were carried out using Review Manager 5.1. For cases in which necessary information was not reported in the paper, we contacted the primary authors for additional information.

MAIN RESULTS

Five randomised trials involving 664 participants were analysed. Five different herbal medicines were tested in these trials, including Huo-Xue-Tong-Fu decoction, Xiao-Cheng-Qi-Tang decoction, a combination of Xiao-Cheng-Qi-Tang and Si-Jun-Zi-Tang decoctions, Chang-Nian-Lian-Song-Jie-Tang decoction, and Fufang-Da-Cheng-Qi-Tang decoction. There were variations in the tested herbal compositions and methods of medicine administration. The main outcomes reported in the trials were effects on abdominal pain, abdominal distension, constipation defection, time of first defecation after treatment, and reoperation rate during the course of the disease. Secondary outcomes selected for this review were not available, including complications such as small bowel perfusion (bowel resection, system complications, and other possible complications), length of hospital stay, cost of hospitalisation, and time from admission to surgical intervention. The results of five trials showed that patients receiving TCM combined with conventional therapy seemed to have improved outcomes compared with patients receiving conventional treatment alone (OR 4.24, 95% CI 2.83 to 6.36).However, we cannot conclusively determine the efficacy of TCM in this review due to inadequate reporting, low methodological quality, and the prevalence of various biases in the reviewed studies. Furthermore, because none of the reviewed trials discussed adverse events, we could not evaluate the safety of TCM for adhesive SBO patients. All trials were conducted and published in China.

AUTHORS' CONCLUSIONS

Although many studies have assessed the use of TCM products for adhesive SBO, most were excluded from this review due to their methodological limitations. This systematic review did not find sufficient evidence to support the objective efficacy and safety of TCM for patients with adhesive SBO. The positive evidence should be interpreted with caution given the insufficient number of studies with large sample sizes, the absence of well-designed, high-quality trials, and the lack of safety information. Therefore, further studies with larger sample sizes and high-quality, randomised, and controlled trials are necessary to produce more accurate and meaningful data on the efficacy of Chinese herbal medicines for adhesive SBO.

Secular trends in small-bowel obstruction and adhesiolysis in the United States: 1988-2007

BACKGROUND

Postoperative adhesions are common after surgery and can cause small-bowel obstruction (SBO) and require adhesiolysis. The impact that laparoscopy and other surgical advances have had on rates of SBO and adhesiolysis remains controversial. This study examines trends in discharges from US hospitals for SBO and adhesiolysis from 1988 to 2007.

METHODS

We performed an analysis of secular trends for SBO and adhesiolysis, using the National Hospital Discharge Survey. Spearman correlation coefficients were calculated to assess trends over time.

RESULTS

Rates of SBO were stable over time (ρ = .140; P = .28). Adhesiolysis rates were stable over time (ρ = -.18; P = .17), although there were significant downward trends in patients older than age 65 (ρ = -.55; P = .01) and age 15 to 44 (ρ = -.84; P < .01).

CONCLUSIONS

There has been no significant change in overall rates of SBO or adhesiolysis from 1988 to 2007. For adhesiolysis, there were decreasing trends when stratified by age. Further research is required to understand the factors associated with adhesion-related complications.

New and Simple Approach for Preventing Postoperative Peritoneal Adhesions: Do not Touch the Peritoneum without Viscous Liquid-A Multivariate Analysis

Background. Postoperative peritoneal adhesions (PPAs) are an unsolved and serious problem in abdominal surgery. Method. Viscous liquids of soybean oil, octyl methoxycinnamate, flax oil, aloe vera gel, and glycerol were used in five experiments, using the same methodology for each. Liquids were applied in the peritoneal cavity before and after mechanical peritoneal trauma. Results were evaluated by multivariate analysis. Results. Compared with the control group, macroscopic and microscopic adhesion values before (P < .001) and after (P < .05) application of viscous liquids significantly reduced PPAs. Values were significantly lower when liquids were applied before rather than after peritoneal trauma (P < .0001). Discussion. Viscous liquids injected into the peritoneal cavity before or after mechanical peritoneal trauma decrease PPA. Injection before trauma was more effective than after trauma. In surgical practice, PPA formation may be prevented or decreased by covering the peritoneal cavity with an appropriate viscous liquid before abdominal surgery.