Laparoscopic application of hyaluronate/carboxymethylcellulose slurry: an adhesion barrier in a slurry formulation goes where the available sheets cannot

Cost-effectiveness of the prevention of adhesions and adhesive small bowel obstruction after colorectal surgery with adhesion barriers: a modelling study

Background

Adhesion barriers have proven to reduce adhesion-related complications in colorectal surgery. However, barriers are seldom applied. The aim of this study was to determine the cost-effectiveness of adhesion barriers in colorectal surgery.

Methods

A decision-tree model was developed to compare cost-effectiveness of no adhesion barrier with the use of an adhesion barrier in open and laparoscopic surgery. Outcomes were incidence of clinical consequences of adhesions, direct healthcare costs, and incremental cost-effectiveness ratio per adhesion prevented. Deterministic and probabilistic sensitivity analyses were performed.

Results

Adhesion barriers reduce adhesion incidence and incidence of adhesive small bowel obstruction in open and laparoscopic surgery. Adhesion barriers in open surgery reduce costs compared to no adhesion barrier ($4376 versus $4482). Using an adhesion barrier in laparoscopic procedures increases costs by $162 ($4482 versus $4320). The ICER in the laparoscopic cohort was $123. Probabilistic sensitivity analysis showed 66% and 41% probabilities of an adhesion barrier reducing costs for open and laparoscopic colorectal surgery, respectively.

Conclusion

The use of adhesion barriers in open colorectal surgery is cost-effective in preventing adhesion-related problems. In laparoscopic colorectal surgery, an adhesion barrier is effective at low costs.

Effect of Hydrogen-Rich Saline on Postoperative Intra-Abdominal Adhesion Bands Formation in Mice

Background

Postsurgical peritoneal adhesions (PPAs) are pathologic fibrous bands within the peritoneal cavity. The aim of this study was to investigate the protective effect of hydrogen-rich saline (HRS) on PPAs formation in mice.

Material/Methods

Adhesions were induced in mice using the cecum rubbing model. The mice were allocated into 4 groups: control sham group without cecum rubbing; PPA group with saline applied intraperitoneally (i.p.) daily after cecum rubbing; PPA+HRS (5) group with 5 ml/kg of HRS applied i.p. daily after cecum rubbing; and PPA+HRS (10) group with 10 ml/kg of HRS applied i.p. daily after cecum rubbing. On the 1^st, 3^rd, and 7^th days after the operation, mice were killed and pathological adhesion bands were quantified to detect the effect of HRS on PPAs formation.

Results

HRS did not affect PPAs formation on the 1^st day, but did make a significant reduction on the 3^rd and 7^th days. A significant increase of t-PA and decrease of TGF-β1 and PAI-1 in the peritoneal fluids were observed in the HRS-treated groups. The levels of MDA and MPO in the HRS-treated groups were significantly lower than those in the PPA group. TNF-α and IL-6 levels in HRS-treated groups significantly decreased compared with those in the PPA group on postoperative day 3 and 7. Moreover, HRS decreased the mRNA levels of pro-inflammatory cytokines and TGF-β1 expression in the postsurgical adhesion bands.

Conclusions

These results showed that HRS had therapeutic potential for preventing PPAs formation, possibly through balancing the expression of TGF-β1, t-PA, and PAI-1, and inhibiting oxidative stress and inflammation.

Multi-layered intra-abdominal adhesion prophylaxis following laparoscopic colorectal surgery

BACKGROUND

Small bowel obstruction secondary to intra-abdominal adhesions is a frequent postoperative complication. Less invasive surgery carries a lower risk of postoperative adhesions, but adhesions may still occur after laparoscopic colorectal surgery. We present here some of our methods of adhesion prophylaxis for laparoscopic colorectal surgery.

METHODS

The 167 patients who underwent laparoscopic colorectal surgery at our center from 2007 to 2012 were retrospectively reviewed. To prevent postoperative intra-abdominal adhesions, anti-adhesion barriers were placed using the half-overlap method. The rate of postoperative small bowel obstruction was compared among three groups: patients who received no adhesion prophylaxis (Group NP), patients who received single-layered adhesion prophylaxis adjacent to the incision (Group SP), and patients who received three layers of adhesion prophylaxis at different depths (Group MLP).

RESULTS

The rate of postoperative ileus was significantly different among the three groups, at 9.7 % (6/62) in Group NP, 5.0 % (1/19) in Group SP, and 0 % (0/86) in Group MLP).

CONCLUSIONS

This retrospective analysis found that placement of multi-layered anti-adhesion barriers using the half-overlap method provided the most effective prophylaxis. Prospective clinical trials are needed to further evaluate these methods of anti-adhesion prophylaxis.

The neurokinin 1 receptor regulates peritoneal fibrinolytic activity and postoperative adhesion formation

BACKGROUND

Intra-abdominal adhesions are a common source of postoperative morbidity. Previous studies in our laboratory have shown that a neurokinin 1 receptor antagonist (NK-1RA) reduces abdominal adhesion formation and increases peritoneal fibrinolytic activity. However, the cellular pathway by which the antagonist exerts its effects is unclear, as cultured peritoneal mesothelial cells exposed to the NK-1RA show increases in fibrinolytic activity despite having very low expression of neurokinin 1 receptor (NK-1R) messenger RNA and protein. Our aim was to determine whether the NK-1R plays an essential role in the adhesion-reducing effects of the NK-1RA, or if the NK-1RA is acting independently of the receptor.

METHODS

Homozygous NK-1R knockout mice and age matched wild-type mice underwent laparotomy with cecal cautery to induce adhesions. At the time of surgery, mice received a single intraperitoneal dose of either NK-1RA (25 mg/kg) or saline alone. Adhesion severity at the site of cecal cautery was assessed on postoperative day 7. In a separate experiment, peritoneal fluid was collected from wild type and NK-1R knockout mice 24 h after laparotomy with cecal cautery and administration of either NK-1RA or saline. Tissue plasminogen activator levels, representative of total fibrinolytic activity, were then measured in peritoneal fluid.

RESULTS

In wild-type mice, NK-1RA administration significantly decreased adhesion formation compared with saline controls. Among the NK-1R knockout mice, there was no significant reduction in adhesion formation by the NK-1RA. Fibrinolytic activity increased 244% in wild-type mice administered NK-1RA compared with saline controls; however, the NK-1RA did not raise fibrinolytic activity above saline controls in NK-1R knockout mice.

CONCLUSIONS

These data indicate that the NK-1R mediates the adhesion-reducing effects of the NK-1RA, in part, by the upregulation of peritoneal fibrinolysis, and suggest that the NK-1R is a promising therapeutic target for adhesion prevention.

Histone deacetylase inhibitors decrease intra-abdominal adhesions with one intraoperative dose by reducing peritoneal fibrin deposition pathways

BACKGROUND

We previously demonstrated that postoperative peritoneal injury and inflammation contribute to adhesiogenesis. Recent evidence suggests that in addition to their role of interfering with the acetylation status of nuclear histone proteins, histone deacetylase inhibitors (HDACIs) including valproic acid (VPA) can target nonhistone proteins to resolve inflammation and modulate immune cells. We hypothesized that HDACIs could reduce adhesions.

METHODS

Seventy-two rats underwent laparotomy with creation of 6 peritoneal ischemic buttons to induce adhesions. A single intraperitoneal (IP) dose of 50 mg/kg VPA was administered intraoperatively, whereas controls received vehicle. To evaluate the timing, 25 rats underwent ischemic button creation with either an intraoperative or a delayed IP dose of VPA at 1, 3, or 6 hours postoperatively. On postoperative day 7, adhesions were quantified. To investigate mechanisms, ischemic buttons were created in 24 rats and either VPA or saline was administered in 1 intraoperative dose. At 3 or 24 hours later, peritoneal fluid was collected and fibrinolytic activity measured. Alternatively, button tissue was collected 30 minutes postoperatively to measure tissue factor, fibrinogen, and vascular endothelial growth factor (VEGF) by real-time polymerase chain reaction or Western blot.

RESULTS

A single intraoperative dose of VPA reduced adhesions by 50% relative to controls (P < .001). Delayed dosing did not reduce adhesions. In operated animals, peritoneal fibrinolytic activity was not different between groups. Tissue factor mRNA was downregulated by 50% (P = .02) and protein by 34% (P < .01) in animals administered VPA versus saline. VPA decreased fibrinogen protein by 56% and VEGF protein by 25% compared with saline (P = .03).

CONCLUSION

These findings suggest that VPA rapidly reduces the extravasation of key adhesiogenic substrates into the peritoneum. A single, intraoperative intervention provides an ideal dosing strategy and indicates an exciting new role for HDACIs in adhesion prevention.

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.

Seprafilm(®) adhesion barrier: (2) a review of the clinical literature on intraabdominal use

This study seeks to provide a review of the clinical data published as of July 2011 concerning the postsurgical adhesion barrier, Seprafilm (chemically modified hyaluronic acid and carboxymethylcelulose; Genzyme Corporation, Cambridge, MA). Included articles detail the application of Seprafilm for intraabdominal uses that have been approved (on-label) and those considered investigational (off-label) by the FDA. Medline and EMBASE Drugs and Pharmaceuticals databases were searched for all original clinical Seprafilm research published as of July 2011. All human Seprafilm intraabdominal clinical reports and studies, excluding those related to prosthetic mesh were included. Data extraction involved the systematic review of each article. The data synthesis is the summary of Seprafilm human intraabdominal clinical reports and studies describing safety and/or efficacy. The safety and efficacy of Seprafilm in reducing postoperative adhesions has been clearly demonstrated in abdominal and pelvic laparotomy. While reports have described the safe and successful use of Seprafilm following laparoscopy, pediatric laparotomy, and in patients with malignancy and/or infection, the safety and efficacy of Seprafilm use in these procedures has not been definitively established in randomized controlled trials.

A sprayable hyaluronate/carboxymethylcellulose adhesion barrier exhibits regional adhesion reduction efficacy and does not impair intestinal healing

BACKGROUND

While bioresorbable solid barriers such as Seprafilm® prevent adhesions, their efficacy is limited to sites of application. The aim of this study was to assess the effectiveness of the sprayable adhesion barrier Sepraspray® in preventing adhesions to sites of direct application and to remote sites.

METHODS

Intraabdominal adhesions were induced in 30 rats by creating three ischemic buttons on each side of a midline incision. To assess efficacy, Sepraspray (5 mg/button) or Seprafilm (1 cm(2)/button) was applied over three buttons on one side of the peritoneum. Operated control animals received no treatment. On day 7, adhesions were scored as percent of buttons with adhesions. To assess safety, 81 rats underwent a colonic transection repaired with an end-to-end anastomosis. Both barriers were applied circumferentially to anastomoses. Controls received no product. The integrity of healing anastomosed colonic wounds was assessed by burst pressure and tensile strength at days 3, 5, and 7 postoperatively.

RESULTS

The direct application of both Sepraspray and Seprafilm significantly (p < 0.001) reduced adhesion formation compared to controls. While Seprafilm had no remote effect on adhesion formation, Sepraspray significantly (p < 0.001) reduced adhesion formation to contralateral ischemic buttons. Neither barrier affected anastomotic integrity at any time point.

CONCLUSIONS

Sepraspray has widespread efficacy throughout the peritoneum in reducing adhesions without compromising intestinal healing. Furthermore, this sprayable alternative offers the potential for easier intraabdominal application.

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

OBJECTIVE

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

DESIGN

Multicenter, randomized, reviewer-blinded trial.

SETTING

Reproductive endocrinology and infertility clinics.

PATIENT(S)

Women undergoing laparoscopic myomectomy for indications including infertility.

INTERVENTION(S)

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

MAIN OUTCOME MEASURE(S)

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

RESULT(S)

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

CONCLUSION(S)

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

CLINICAL TRIAL NUMBER

Sepraspray Adhesion Barrier #NCT00624930.

Laparoscopic use of a hyaluronic acid carboxycellulose membrane slurry in gynecological oncology

Described in this study is the use of a hyaluronic acid carboxycellulose slurry to prevent adhesions in complex gynecological cases.

Objectives:

We evaluated the use of a hyaluronic acid-carboxycellulose membrane (HAC) slurry in complex laparoscopies.

Materials and Methods:

A gel-like mixture of HAC was prepared and applied in 171 consecutive complex laparoscopies on a gynecologic oncology service. The HAC slurry was used to coat deperitonealized surfaces and surgical pedicals to prevent postoperative adhesions. The technique is described and the outcomes are prospectively evaluated for feasibility and safety.

Results:

There were no postoperative bowel obstructions, 1 pelvic hematoma in a patient on clopidogrel (Plavix) immediately prior to surgery, 8 postoperative ilea, and 1 bowel perforation. The bowel perforation occurred in a patient with extensive adhesiolysis and intraoperative bowel suturing.

Conclusion:

This report describes an easy approach to the laparoscopic application of HAC. Caution should be taken if HAC slurry is applied after significant bowel suturing because 1 of 9 patients with extensive adhesiolysis requiring suturing of the sigmoid colon developed sigmoid perforations.

A membrane slurry reduces postoperative adhesions in rat models of abdominal surgery

BACKGROUND

Sodium hyaluronate and carboxymethylcellulose (HA-CMC) membrane is an effective barrier material for limiting postoperative adhesions, but can be difficult to apply in certain situations due to its physical properties. We tested whether HA-CMC membrane hydrated in saline (slurry) is an effective alternative to HA-CMC membrane for preventing surgical adhesions in rat models of abdominal surgery.

MATERIALS AND METHODS

All studies were performed in rat cecal abrasion or sidewall defect models of adhesion formation. Adhesions were examined 7 d after surgery. In separate studies, the effects of variations in slurry composition, volume, and site of application on anti-adhesive properties were studied and compared with untreated controls. Finally, the effectiveness of HA-CMC membrane slurry for preventing adhesions was compared with that of conventional HA-CMC membrane.

RESULTS

Application of HA-CMC membrane slurry to traumatized tissue resulted in a significant reduction in the incidence of adhesions compared with untreated controls in both rat surgery models. Slurry was equally effective when applied in low and high film-to-volume formulations, but had minimal effect when applied in a small volume or at a location distal to the injury. Comparison of HA-CMC membrane slurry and conventional HA-CMC membrane indicated similar efficacy for reducing postoperative adhesions.

CONCLUSIONS

In rat models of abdominal surgery, HA-CMC membrane slurry reduced postoperative adhesion formation and may be an effective alternative for HA-CMC membrane in situations where its use is limited by its physical properties.