Reduce Adhesion Formation Research Articles

Effects of hyaluronic acid/carboxymethylcellulose gel on bowel anastomoses in the New Zealand white rabbit

Intra-abdominal adhesions form in more than 90% of patients undergoing major abdominal surgery and can lead to significant complications. Application of a bioresorbable gel consisting of chemically modified hyaluronic acid (HA) and carboxymethylcellulose (CMC) has shown promise as a means of preventing intra-abdominal adhesions, but there have been concerns that the presence of the gel might interfere with the integrity and healing of bowel anastomoses. We tested the effects of HA/CMC gel on adhesion formation and anastomotic healing in 60 New Zealand white rabbits after transection and complete (100%) or incomplete (90%) anastomosis of the ileum. Half of the animals underwent application of HA/CMC gel and half served as control subjects. Animals were killed at 4, 7, or 14 days after surgery. Anastomotic adhesions were scored in a blinded fashion. Integrity of the anastomosis was tested by measuring bursting pressure at the anastomotic site and in an adjacent section of intact bowel. With complete anastomosis HA/CMC gel significantly reduced adhesion formation at 7 and 14 days after surgery ( P <0.05), but gel application did not inhibit adhesion formation when the anastomosis was incomplete. Anastomosed segments of bowel burst at a lower pressure than intact bowel 4 days after surgery, but bursting pressures were normal at 7 and 14 days. Burst pressures of anastomoses receiving an application of HA/CMC gel were nearly identical to control anastomoses at all three time points. HA/CMC gel did not interfere with the normal healing process of bowel anastomoses. Furthermore, HA/CMC gel decreased adhesion formation after complete anastomoses, yet it did not affect adhesion formation in the presence of anastomotic disruption.

Gonadotrophin-Releasing Hormone Agonist (GnRHa) Therapy Alters Activity of Plasminogen Activators (PA), Matrix Metalloproteinases (MMP) and of Their Inhibitors (PAI and MMPI) in Rat Models for Adhesion Formation and Endometriosis: Potential GnRHa-Regulated Mechanisms Reducing Adhesion Formation

Gonadotrophin-Releasing Hormone Agonist (GnRHa) Therapy Alters Activity of Plasminogen Activators (PA), Matrix Metalloproteinases (MMP) and of Their Inhibitors (PAI and MMPI) in Rat Models for Adhesion Formation and Endometriosis: Potential GnRHa-Regulated Mechanisms Reducing Adhesion Formation

Reduction of adhesion formation by postoperative administration of ionically cross-linked hyaluronic acid

To examine the efficacy of various formulations of hyaluronic acid (HA), including HA ionically cross-linked with trivalent iron, in animal models of adhesion formation. Hyaluronic acid formulation of varying concentrations and cross-linked densities were prepared and evaluated in a rabbit uterine horn model and a rabbit sidewall model. ETHICON, Inc., Somerville, New Jersey. New Zealand White rabbits. Test formulations were applied as intraperitoneal instillates after surgery. Adhesion formation was assessed at 7 and 14 days (sidewall and uterine horn model, respectively). Hyaluronic acid that was not ionically cross-linked was ineffective in reducing adhesions in these models even at high viscosity, whereas the ionically cross-linked formulations of HA with trivalent iron were highly effective. Efficacy improved with increased levels of ionic cross-linking. Flowable gels, which could be delivered readily by syringe and cannula, also were effective when administered at a site remote from injury and with saline present. Whereas previous studies show that HA was effective in reducing adhesions peripheral to the site of injury, HA ionically cross-linked with trivalent iron was effective in reducing adhesions at all sites. From these studies, a formulation of HA ionically cross-linked with trivalent iron, 0.5% Ferric Hyaluronate Gel (LUBRICOAT; ETHICON, Inc., Somerville, NJ), was identified for subsequent clinical evaluations.

R-235. Comparison of REPEL™ and INTERCEED™ in the reduction of adhesion formation in the presence of blood in rabbit models

R-235. Comparison of REPEL™ and INTERCEED™ in the reduction of adhesion formation in the presence of blood in rabbit models

Reduction of adhesion formation with hyaluronic acid after peritoneal surgery in rabbits

To examine the effect of hyaluronic acid, a high-molecular-weight glucosaminoglycan found in the extracellular matrix, on the formation of adhesions, a major source of postoperative complications. The ability of hyaluronic acid to reduce adhesion formation was evaluated using a standardized rabbit model. The material was administered i.p. at the end of surgery. University laboratory. New Zealand White female rabbits. Intraperitoneal administration of various formulations of hyaluronic acid at the end of surgery. One week after surgery, a second laparotomy was performed and the extent of adhesion formation was determined. Five separate molecular weight ranges of hyaluronic acid representing eight viscosities between 1,000 and 12,000 centipoise (CPS) were shown to reduce adhesion formation in this model. All volumes, 1 to 30 mL, of hyaluronic acid tested reduced adhesion formation. In addition, the low-viscosity, low-molecular-weight hyaluronic acid significantly reduced adhesion formation when added to the trauma site or when injected at a site remote from the trauma area. This study showed that hyaluronic acid administered at the end of surgery reduced adhesion formation.

Prevention of postsurgical adhesions with N,O-carboxymethyl chitosan: Examination of the most efficacious preparation and the effect of N,O-carboxymethyl chitosan on postsurgical healing

Background. Adhesion formation after operation can result in major complications. We have previously demonstrated that N,O-carboxymethyl chitosan (NOCC) is an effective inhibitor of postsurgical peritoneal adhesion formation. However, the optimal form of NOCC (i.e., cross-linked gel versus solution), as well as the best time of administration for optimal reduction in adhesion development, was not investigated. In addition, because adhesion formation and normal wound healing are related events and weakening of wound healing would be a serious drawback to the use of NOCC clinically, we wished to assess the effect of NOCC on the healing of surgical incisions. Methods. Three surgical models were used: (1) an abdominal aortic anastomosis, (2) a large bowel anastomosis, and (3) an abdominal skin incision. In the first model Sprague-Dawley rats received an abdominal aortic transection and repair. NOCC solution or gel was administered at different time points throughout the procedure. Control and NOCC-treated animals were killed 14 days after operation. The condition of the anastomosed vessel was examined, and adhesion frequency and intensity in the abdomen were scored. In the second model Sprague-Dawley rats underwent large bowel transection and repair. Control and NOCC-treated animals were killed on postoperative days 4, 7, and 14, and strength of repair was assessed by removal of the large bowel and measurement of the bursting strength of the repaired incision. In the third model rats received an abdominal incision and were immediately closed. Control and NOCC-treated animals were killed 14 days after operation, and the skin tensile strength of the wound was measured with a tensiometer. Results. In all three models studied, NOCC treatment did not adversely affect the strength of the repaired incision. NOCC solution administered before operation did not greatly reduce adhesion formation, whereas the delivery of both NOCC gel and solution after operation was most efficacious. Conclusions. The administration of both NOCC gel and solution after operation is most efficacious, and NOCC does not compromise postsurgical healing in rats at doses that prevent peritoneal adhesion formation.

Reduction of Adhesion Formation by Intraperitoneal Administration of Anti-inflammatory Peptide 2

Adhesion formation is a major source of postoperative morbidity and mortality. Therefore, the reduction of postoperative adhesion formation would be of clinical benefit. Various modalities have been shown to reduce adhesion formation, including fibrinolytic enzymes, nonsteroidal anti-inflammatory drugs, and barriers that reduce the apposition of sites of potential adhesion formation. This study examined the ability of a phospholipase A2 inhibitor, anti-inflammatory peptide 2 (antinflammin), to reduce the formation of intraperitoneal adhesions in two rabbit models of adhesion formation. In the sidewall model, antinflammin was administered via Alzet miniosmotic pump for the entire postoperative interval, and there was a dose-dependent reduction in the area of the sidewall injury that was involved in adhesions to the cecum and the bowel. In the double uterine horn model, antinflammin was administered via Abet miniosmotic pump to the area of injury for either 1, 2, 3, or 7 days. Administration of antinflammin for as little as 24 h after surgery significantly reduced the extent of adhesion formation. Administration of the peptide for longer periods of time did not further increase the reduction in adhesion formation. These studies clearly demonstrate that postoperative administration of antinflammin to the site of injury reduced the formation of postoperative adhesions in two animal models.

Prevention of Adhesion Formation with Intraperitoneal Administration of Tolmetin and Hyaluronic Acid

Adhesion formation after peritoneal surgery is a major source of postoperative complications and pain. Previous studies showed that intraperitoneal administration of the nonsteroidal anti-inflammatory drug tolmetin reduced adhesion formation after two types of peritoneal surgery. The effect of tolmetin combined with hyaluronic acid (HA), a high-molecular-weight glucosaminoglycan found in the extracellular matrix, on the formation of adhesions was examined. In this study, the effect of tolmetin in HA on adhesion formation was evaluated in a standardized rabbit model. The medicament was administered intraperitoneally at the end of surgery. One week after surgery, a second laparotomy was performed and the extent of adhesion formation was determined. A range of molecular weights (7.5 × 105-2 × 106 Da) and viscosities (1000–25,000 centapoise) of HA in combination with tolmetin was effective in reducing adhesion formation. However, low viscosity HA solutions in combination with tolmetin, 0˙5–2˙0 mg/mL, were most efficacious in reducing adhesion formation. These data suggest that HA, in combination with tolmetin, acts as an effective carrier to reduce adhesion formation in the abdominal cavity after surgery.

O-134 Gonadotrophin-releasing hormone agonist (GnRHa) therapy alters activity of plasminogen activators (PA), Matrix Metalloproteinases (MMP) and of their inhibitors (PAI and MMPI) in rat models for adhesion formation and endometriosis: Potential GnRHa-regulated mechanisms reducing adhesion formation

O-134 Gonadotrophin-releasing hormone agonist (GnRHa) therapy alters activity of plasminogen activators (PA), Matrix Metalloproteinases (MMP) and of their inhibitors (PAI and MMPI) in rat models for adhesion formation and endometriosis: Potential GnRHa-regulated mechanisms reducing adhesion formation

Adenovirus-mediated gene transfer into tendon and tendon sheath.

In this study, we successfully transferred the Escherichia coli beta-galactosidase gene. LacZ, into the chicken tendon and tendon sheath by a recombinant adenovirus. The recombinant adenovirus Adv-beta gal that carried the E. coli LacZ gene was constructed by homologous recombination in 293 cells (human transformed embryonic kidney) between the expressing vector and the ClaI large fragment of adenovirus 5 genome. Each chicken received a 10 microliters injection containing 10(5) plaque-forming units of recombinant virus Adv-beta gal. into the tendon sheath of the long toe Samples of tendon and tendon sheath were harvested at 3.30, and 75 days after the injection. The LacZ gene transfer was detected for its coding product beta-galactosidase by staining with X-gal solution. The results showed that all tendon and tendon sheath samples from the three harvest times stained positive (blue). The tendon sheath samples were more extensively stained; staining of the tendon was limited to the epitenon layer. These data suggest that a functional exogenous gene can potentially be transferred into the tendon and tendon sheath by similar techniques; such techniques may be used to improve healing and reduce adhesion formation.

Efficacy of tenoxicam on intra-abdominal adhesion prevention in a rat model.

The aim of this study was to investigate the effect of tenoxicam as a non-steroidal anti-inflammatory drug (NSAID) on intra-abdominal adhesion prevention in a rat model. Altogether 50 Wistar-Albino rats weighing 220-280 g were assigned to five groups, each of which was made up of 10 rats. All the rats were anaesthetized and prepared for sterile surgery. After a mid-line laparotomy was performed, a 1 cm area of the caecum was rubbed with gauze until subserosal haemorrhage developed, and then a 5 mm-diameter part of the peritoneum on the right side of the abdominal wall was removed. Prior to complete closure, 3 ml of the test material was placed into the abdominal cavity. On the eighth day the rats were killed and the adhesion score was determined. The groups and their mean adhesion scores were as follows: control group (normal saline), 2.5; group of dilution buffer, 1.8; tenoxicam (0.125 mg/kg), 1.3; tenoxicam (0.25 mg/kg), 1.3; and tenoxicam (0.5 mg/kg), 0.9. The differences between the adhesion scores among all the groups (P < 0.05, Kruskal-Wallis test), and those between the tenoxicam groups and control group (P < 0.05, Mann-Whitney U-test), were significant. Thus a single instillation of tenoxicam into the peritoneal cavity at the time of surgery reduced adhesion formation effectively in this model, irrespective of dosage.

Reduction of postoperative adhesion formation after laparoscopic ovarian cystectomy

The purpose of this randomized, open-label study was to assess the efficacy of the product Interceed absorbable adhesion barrier in the prevention of adhesion formation on the ovary after laparoscopic ovarian cystectomy. A total of 25 patients requiring laparoscopic bilateral ovarian cystectomy were enrolled into this study. After removal of ovarian cysts, peri-adnexal adhesions, and peritoneal irrigants, and the attainment of meticulous haemostasis, the random assignment of one ovary for wrapping with Interceed was revealed to the surgeon. The other ovary served as the untreated control. A follow-up laparoscopy was performed 8-30 weeks after the initial procedure in 17 patients. Significantly fewer adhesions formed at the Interceed treated ovaries compared with the control (untreated) ovaries (P < 0.05). In terms of adhesion-free outcome, 76% (13/17) of Interceed treated ovaries and 35% (6/17) of control ovaries were free of adhesions. A significant reduction was observed in the area of the sutured ovaries involved with adhesions when Interceed (6%) was used, compared with controls (20%). The reduction of adhesion formation was not related to the size of the cysts at the initial procedure. No adverse events were reported by any patient during the study. In conclusion, Interceed was found to be safe and effective in reducing the incidence of postoperative adhesion formation in patients undergoing laparoscopic ovarian cystectomy.

Kinetics of transperitoneal tissue-type plasminogen activator absorption

Peritoneal hypofibrinolysis has been suggested to be a central denominator in the formation of postoperative adhesions. Topical application of tissue-type plasminogen activator (t-PA) has been demonstrated to reduce adhesion formation, but the absorption of t-PA is not known. The aim of the present study was to determine the absorptive kinetics of t-PA by injecting varying doses of t-PA in intraperitoneally (i.p.) in rats. Plasma elimination was investigated in another set of experiments, where the same doses were injected intravenously (i.v.). The concentrations of t-PA in plasma were dose-dependent after both administrations, and at three and six hours the t-PA concentration in plasma was significantly higher after i.p. [64 (12.8) ng/mL (40 μg dose)] and [297.6 (6.7) (400 μg dose)] then after i.v. [27.9 (15.8) (40 μg dose)] and [127.0 (35.0) (400 μg dose)] (P<0.05). Uptake rate of t-PA from the peritoneal cavity was 2.4–6.2 μL/min, which is compatible with peritoneal lymph flow. Plasma clearance was rapid after an i.v. injection (3.3–5.7 mL/min), and slower (0.8–1.7 mL/min) after i.p. administration, indicating a greater availability of t-PA when given i.p. To increase abdominal fibrinolytic capacity without affecting systemic fibrinolysis, a slow-release form of t-PA has to be used. The finding that i.p. administration gave rise to prolonged elevation of plasma concentration as compared to an i.v. injection may have some therapeutic implications in thrombolysis.

Local Release of Fibrinolytic Agents for Adhesion Prevention

Tissue plasminogen activator (tPA), urokinase plasminogen activator (uPA), and streptokinase were evaluated for their ability to reduce postsurgical adhesion formation in a rat uterine horn devascularization and serosal injury model in a blinded, randomized study. Small doses of tPA, uPA, or streptokinase were delivered over approximately a 4-day period either from a biodegradable hydrogel matrix or as four daily intraperitoneal injections. The hydrogel was formed upon the uterine horns by photopolymerization of an aqueous precursor solution containing dissolved drug. A control group that received no treatment had an average extent of adhesion formation of 72 ± 15% (mean ± SEM, percentage of the length of the uterine horns involved in adhesions). Application of this formulation of the hydrogel alone reduced the extent of adhesion formation to 22 ± 10% by functioning as a mechanical barrier. When tPA was released from the hydrogel, adhesion formation was reduced to 4 ± 3%, while when tPA was given by intraperitoneal injection, adhesion formation was only reduced to 49 ± 8%. Local delivery of urokinase reduced adhesion formation to 6 ± 6%, but intraperitoneal injection of urokinase did not reduce adhesion formation. Streptokinase did not reduce adhesion formation when administered by intraperitoneal injection and increased adhesion formation to 45 ± 9% when locally released relative to the hydrogel alone. These results suggest that both tPA and uPA may be used to prevent adhesion formation when delivered locally.

Comparison of covalently and physically cross-linked polyethylene glycol-based hydrogels for the prevention of postoperative adhesions in a rat model

A covalently and a physicochemically cross-linked hydrogel, both based primarily on polyethylene glycol and both formed in situ, were compared side by side in a rat uterine horn devascularization and serosal injury model for efficacy in adhesion prevention. The primary difference between the two materials was the nature of their cross-linking. The covalently cross-linked hydrogel was a photopolymerized polyethylene glycol- co-lactic acid diacrylate, and the physically cross-linked hydrogel was a polyethylene glycol-co-polypropylene glycol, Poloxamer 407 ®. In the surgical model employed, application of the covalently cross-linked hydrogel reduced the extent of adhesion formation from 75 ± 10% in the control group to 16 ± 6% (mean ± s.d., P < 0.001). Application of the physically crosslinked hydrogel reduced adhesion formation to 38 ± 19% ( P < 0.01). Retention of the two hydrogels upon the site of application was also evaluated. The covalently cross-linked hydrogel formed a continuous barrier upon the uterine horns for more than 4 d, while the physicochemically cross-linked hydrogel was present upon the uterine horns for less than 2 d. This difference in retention was probably the cause of the difference in efficacy and may be attributed to the nature of the cross-linking.

Analysis of the kinetics of peritoneal adhesion formation in the rat and evaluation of potential antiadhesive agents

Peritoneal adhesions continue to be a significant cause of postoperative complications. Elucidating the origin of these adhesions has been hampered by the lack of a reproducible animal model. The purpose of this study was to create a standardized model in which a single, specific adhesion could be objectively measured. With this model the kinetics of adhesion formation were then evaluated. A variety of potential antiadhesive agents were then tested and compared. In this study a reproducible, quantitative rat model was developed that used uniform defects on the peritoneal wall and cecal surface. The resulting adhesions were subsequently scored, and their strength was measured with a tensiometer. An evaluation of the kinetics of peritoneal adhesion formation was obtained by using a timed removal of silicone elastomer sheeting held between the two injured surfaces. The following antiadhesive agents were evaluated: Ringer's lactate solution; dextran 70 (32%); modified carboxymethylcellulose (1.0% and 2.0%); an absorbable barrier of specially knitted material composed of oxidized regenerated cellulose; fibrin sealant; silicone elastomer film; and expanded polytetrafluoroethylene membrane. Evaluation of the kinetics of peritoneal adhesion formation indicated that the susceptibility for adhesion formation was significantly decreased or eliminated after the first 36 hours. Evaluation of antiadhesion agents indicated that the magnitude of adhesion prevention was directly proportional to the agent's ability to remain at the site of injury during the critical period of adhesion formation. Permanent barriers (silicone elastomer film, expanded polytetrafluoroethylene membrane) provided the greatest antiadhesion effect but were not believed to be ideal agents because they remained at the site of injury well after the critical period of adhesion formation. The incidence of adhesion formation for the other agents was as follows: control (34 of 34), Ringer's lactate (12 of 12), absorbable barrier of knitted cellulose (10 of 10), 32% dextran 70 (8 of 12), 1% carboxymethylcellulose (6 of 12), fibrin sealant (4 of 9), and 2% carboxymethylcellulose (4 of 12). The efficacy of antiadhesion agents appears to be related to the agent's viscosity, ability to coat the wound surface, and residence time at the site of injury. In this rat model an agent that remained on the injured surfaces for at least 36 hours after injury appeared to be more effective in reducing adhesion formation than an agent with a shorter residence time.

Preventing postoperative intraperitoneal adhesion formation with Polyactive™, a degradable copolymer acting as a barrier

In this study a degradable barrier, composed of a poly(ethyleneglycol) and poly(butyleneterephthalate) copolymer (1000 Polyactive™ 55/45), was investigated for the prevention of postoperative adhesion formation. Three different designs of polymer films were used in a standardized rat adhesion model in order to investigate which barrier form would be most efficacious in reducing adhesion formation. Neither non-porous nor porous film reduced the adhesion formation as compared with control experiments. A bilayered film, however, composed of a porous underlayer and a non-porous toplayer, reduced the adhesion formation significantly compared with control animals without a barrier. In the case of adhesion formation with this bilayered film the adhesions were limited to areas that were macroscopically not covered, either due to fractures in or detachment of the barrier. Subsequently a more malleable porous/dense film was designed which did not fracture and reduced the adhesion formation significantly compared with animals treated with Interceed™, even though some barriers detached as in the first experiment. The porous/dense Polyactive™ barrier seems to be a promising adjuvant in the reduction of postoperative adhesion formation, although further research is needed to accomplish better attachment of the barrier.

Gonadotropin-releasing hormone agonist therapy reduces postoperative adhesion formation and reformation after adhesiolysis in rat models for adhesion formation and endometriosis

To evaluate the effectiveness of GnRH agonist (GnRH-a) therapy on adhesion formation and reformation in established rat models for surgically induced adhesion formation and endometriosis. Before surgery, female Sprague-Dawley rats were injected with GnRH-a or control diluent. Six days later, rats were assigned to one of four surgical groups: [1] endometriosis, [2] endometriosis sham, [3] adhesion model, or [4] adhesion sham. Three weeks after surgery, a second-look laparotomy was performed, adhesions were scored (0 = no adhesions to 3 = severe adhesions) and mechanically disrupted, and rats received a second GnRH-a or diluent injection either analogous to their initial injection or in a crossover design. Three weeks after the second injection, rats were killed and adhesion reformation was scored. Data were evaluated using nonparameteric tests including Mann-Whitney, Kruskal-Wallis, and Friedman's tests comparing GnRH-a treatments with diluent controls. Preoperative GnRH-a therapy reduced adhesion scores in rats with surgically induced endometriosis (mean +/- SEM; GnRH-a 1.1 +/- 0.2 versus diluent 2.2 +/- 0.2) and adhesions (GnRH-a 0.3 +/- 0.1 versus diluent 0.6 +/- 0.1). Pretreatment GnRH-a therapy did not affect adhesion scores in the endometriosis sham procedure. Combined preoperative and postoperative GnRHa therapy (GnRH-a-GnRH-a) but not postoperative GnRH-a therapy alone (diluent-GnRH-a) reduced adhesion reformation after adhesiolysis in the endometriosis model (GnRH-a-GnRH-a 1.1 +/- 0.3, diluent-GnRH-a 1.6 +/- 0.7), the endometriosis sham (GnRH-a-GnRH-a 0.7 +/- 0.2, diluent-GnRHa 1.8 +/- 0.1), and the adhesion model (GnRH-a-GnRH-a 0.3 +/- 0.2, diluent-GnRHa 1.0 +/- 0.5). No adhesions were observed in the adhesion sham group. Gonadotropin-releasing hormone agonist therapy was successful in reducing adhesion formation and reformation. These studies suggest that GnRH-a therapy for adhesion prevention in women should be explored.

Extraperitoneal laparoscopic paraaortic lymph node dissection: development of a technique.

Surgical assessment of cervical cancer spread primarily involves pathologic evaluation of the pelvic and paraaortic lymph nodes. Extended field radiation therapy, which may result in a survival advantage, is often based on such surgical findings, since clinical staging is inaccurate for this purpose. Extraperitoneal lymph node dissection is superior to a transperitoneal laparotomy approach, largely because of the absence of intraperitoneal adhesion formation and resulting bowel complications. Although transperitoneal laparoscopy may reduce adhesion formation when compared with laparotomy, it does not eliminate this problem. We developed an entirely extraperitoneal laparoscopic technique for paraaortic lymph node dissection in a pig model, using latex balloon dissection technology. The technique was quick, had a short learning curve, and eliminated bowel retraction or dissection. Excellent bilateral retroperitoneal exposure was achieved from the level of the renal to the iliac vessels for aortocaval lymph node dissection.

Efficacy of a resorbable hydrogel barrier, oxidized regenerated cellulose, and hyaluronic acid in the prevention of ovarian adhesions in a rabbit model

To compare the efficacy of a resorbable hydrogel material with oxidized regenerated cellulose and hyaluronic acid in an ovarian adhesion model. Controlled, blinded, and randomized study involving female rabbits. Academic research environment. A water-soluble hydrogen precursor was applied to the ovary as a liquid and converted to a hydrogel by exposure to long wavelength ultraviolet light, a 0.4% solution of hyaluronic acid was applied to the ovary, or an oxidized regenerated cellulose patch was applied to the ovary after wedge resectioning. Extent and severity of adhesion formation. Application of the hydrogel reduced adhesion formation by 88%. Neither oxidized regenerated cellulose nor hyaluronic acid reduced adhesion formation. The photopolymerized, resorbable hydrogel material is highly effective for the reduction of periovarian adhesions in this model.