A randomized, controlled trial of Promogran (a collagen/oxidized regenerated cellulose dressing) vs standard treatment in the management of diabetic foot ulcers

HYPOTHESIS

Promogran, a wound dressing consisting of collagen and oxidized regenerated cellulose, is more effective that standard care in treating chronic diabetic plantar ulcers.

DESIGN

Randomized, prospective, controlled multicenter trial.

SETTING

University teaching hospitals and primary care centers.

PATIENTS

A total of 276 patients from 11 centers were enrolled in the study. The mean age of the patients was 58.3 years (range, 23-85 years). All patients had at least 1 diabetic foot ulcer.

INTERVENTIONS

Patients were randomized to receive Promogran (n = 138) or moistened gauze (control group; n = 138) and a secondary dressing. Dressings were changed when clinically required. The maximum follow-up for each patient was 12 weeks.

MAIN OUTCOME MEASURE

Complete healing of the study ulcer (wound).

RESULTS

After 12 weeks of treatment, 51 (37.0%) Promogran-treated patients had complete wound closure compared with 39 (28.3%) control patientss, but this difference was not statistically significant (P =.12). The difference in healing between treatment groups achieved borderline significance in the subgroup of patients with wounds of less than 6 months' duration. In patients with ulcers of less than 6 months' duration, 43 (45%) of 95 Promogran-treated patients healed compared with 29 (33%) of 89 controls (P =.056). In the group with wounds of at least 6 months' duration, similar numbers of patients healed in the control (10/49 [20%]) and the Promogran (8/43 [19%]; P =.83) groups. No differences were seen in the safety measurements between groups. Patients and investigators expressed a strong preference for Promogran compared with moistened gauze.

CONCLUSIONS

Promogran was comparable to moistened gauze in promoting wound healing in diabetic foot ulcers. It showed an additional efficacy for ulcers of less than 6 months' duration that was of marginal statistical significance. Furthermore, Promogran had a safety profile that was similar to that of moistened gauze, with greater user satisfaction. Therefore, Promogran may be a useful adjunct in the management of diabetic foot ulceration, especially in ulcers of less than 6 months' duration.

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.

The use of local agents: bone wax, gelatin, collagen, oxidized cellulose

The use of local agents to achieve hemostasis is an old and complex subject in surgery. Their use is almost mandatory in spinal surgery. The development of new materials in chemical hemostasis is a continuous process that may potentially lead the surgeon to confusion. Moreover, the more commonly used materials have not changed in about 50 years. Using chemical agents to tamponade a hemorrhage is not free of risks. Complications are around the corner and can be due either to mechanical compression or to phlogistic effects secondary to the material used. This paper reviews about 20 animal and clinical published studies with regard to the chemical properties, mechanisms of action, use and complications of local agents.

The role of oxidised regenerated cellulose/collagen in chronic wound repair and its potential mechanism of action

Normal wound healing is a carefully controlled balance of destructive processes necessary to remove damaged tissue and repair processes which lead to new tissue formation. Proteases and growth factors play a pivotal role in regulating this balance, and if disrupted in favour of degradation then delayed healing ensues; a trait of chronic wounds. Whilst there are many types of chronic wounds, biochemically they are thought to be similar in that they are characterised by a prolonged inflammatory phase, which results in elevated levels of proteases and diminished growth factor activity. This increase in proteolytic activity and subsequent degradation of growth factors is thought to contribute to the net tissue loss associated with these chronic wounds. In this study, we describe a new wound treatment, comprising oxidised regenerated cellulose and collagen (ORC/collagen), which can redress this imbalance and modify the chronic wound environment. We demonstrate that ORC/collagen can inactivate potentially harmful factors such as proteases, oxygen free radicals and excess metal ions present in chronic wound fluid, whilst simultaneously protecting positive factors such as growth factors and delivering them back to the wound. These characteristics suggest a beneficial role for this material in helping to re-balance the chronic wound environment and therefore promote healing.

Oxidized cellulose-based hemostatic materials

The application of hemostatic agents is essential to prevent significant blood loss and death from excessive bleeding in surgical or emergency scenarios. Oxidized cellulose is an excellent biodegradable and biocompatible derivate of cellulose, which has become one of the most important hemostatic agents used in surgical procedures. However, to date, there has been no comprehensive report assessing oxidized cellulose-based hemostatic materials. Hence, this paper first reviewed the oxidation preparation, cellulose origin and structure, as well as biodegradability and safety of oxidized cellulose. Then a comprehensive review regarding the hemostatic mechanisms, various forms, modification, and current commercially available products of oxidized cellulose is discussed, which emphatically presents the most significant developments in the recent scientific literature. In conclusion, this paper summarizes the latest developments in oxidized cellulose-based hemostatic materials and provides a reference for further research and development in this field.

Expression of matrix metalloproteinases and growth factors in diabetic foot wounds treated with a protease absorbent dressing

Wound healing in diabetes is impaired, and nonhealing ulceration represent clinically relevant complications. Persistently high levels of matrix metalloproteases (MMPs) contribute to wound chronicity. Thus, the topical use of protease inhibitors might influence wound healing and promote transition from a chronic to an acute wound.

METHODS

In this study, 33 patients with chronic diabetic foot lesions (stage 2a of the University of Texas Wound Classification system) were included. Fifteen patients received redundant "good standard wound care." In addition, 18 patients were treated with a protease inhibitory modulating matrix (the OCR/collagen Promogran matrix, Ethicon) with dressings changed on a daily basis. Prior to treatment and at 4 and 8 days after treatment, two 3-mm punch biopsies were taken from the center of the wounds and analyzed using ELISA techniques for MMPs, tissue inhibitor of MMP-2 (TIMP-2), and interleukin-1beta (IL-1beta) levels. In addition, mRNA levels of MMPs as well as IL-1beta and TNF-alpha were detected using quantitative real-time polymerase chain reaction (TaqMan, Applied Biosystems, Weiterstadt, Germany).

RESULTS

No differences were detected between both groups and at the three time points for the mRNA levels of MMPs as well as of IL-1beta and TNF-alpha. In addition, MMP levels in wound tissue (analyzed by ELISA) were also not significantly different between both groups. However, IL-1beta was increased on day 8 in the treatment group (P=.01) only. Interestingly, we found a significant reduction of the MMP-9/TIMP-2 ratio in the group being treated with the ORC/collagen. These wounds exhibited a more rapid healing rate when treated with the ORC/collagen matrix.

CONCLUSIONS

The local treatment with a protease inhibitor has a beneficial effect on wound healing. In contrast to the data on wound fluid, our study demonstrated for the first time the unaltered mRNA levels of MMPs during treatment with a protease inhibitory modulating matrix. At the cellular level, MMPs were also not statistically different. However, the more relevant ratio of MMP-9/TIMP-2 was decreased in the treatment group. An equally important finding was that we did not detect a compensatory increase in the MMP-RNA expression even though wound size was clearly reduced.

Long term follow-up of transcatheter embolization with autologous clot, oxycel and gelfoam in domestic swine

Transcatheter embolization of the distal gastrosplenic artery as well as the distal right renal artery or one of its bifurcational branches was performed in 9 domestic swine. The animals were embolized with fresh autologous clot, oxycel or gelfoam in groups of 3. The embolic material was opacified with tantalum in several animals. At 4 months, none of the initial occlusions was sustained and recanalization without residuals was found in the left gastroepipolic artery with only one minor exception. Organized thrombi as sole vascular residuals regardless of embolic substance were found in both the terminal splenic artery as well as in the right renal artery distribution in various degrees together with infarcts in both organs. No trace of either oxycel or gelfoam remained, nor tissue reaction against either material. All 3 agents are therefore regarded equivalent in their long term effects and are not suitable for permanent vascular occlusion.

The healing properties of Promogran in venous leg ulcers

OBJECTIVE

To evaluate the healing rate of venous leg ulcers treated with Promogran.

METHOD

Patients with stagnating venous leg ulcers were recruited. Target wounds were > or = 2 cm but < or = 10 cm in any one dimension. Subjects were randomly allocated to receive either Promogran or a non-adherent dressing (Adaptic) with a secondary dressing of gauze followed by short-stress compression (Biflex). Weekly wound assessments occurred over 12 weeks and dressings were changed twice weekly by the investigator and/or nurse team. Planimetry tracings and photographs were blindly reviewed and assessed by two independent investigators. An intent-to-treat analysis was performed.

RESULTS

Seventy-three patients were included. Thirty-seven were randomly allocated Promogran and 36 Adaptic. Twenty-nine patients completed the 12-week follow-up visit, 25 healed before week 12 and 19 stopped follow-up before week 12 for reasons unrelated to healing. Significantly more patients in the Adaptic group than in the Promogran group switched to another dressing (22.2% versus 5.4%; p = 0.035). Eleven venous leg ulcers healed in the control group (31%) and 15 in the Promogran group (41%) (p = 0.373). Overall, 15 venous leg ulcers healed or improved in the control group (42%) and 23 in the Promogran group (62%) (p = 0.079). Surface area decreased, on average, by 36.5 +/- 11.4% (median decrease: 44.6%) in the Adaptic group and by 54.4 +/- 10.9% (median decrease: 82.4%) in the Promogran group (p < 0.001). A < or = 20% surface area reduction was observed in 15 patients in the Adaptic group and in seven in the Promogran group (42% versus 19%; p = 0.034). No severe local adverse events were noted in either group, although poor tolerability caused a dressing switch in five patients in the control group and three in the Promogran group. Dressing acceptability was good or excellent in more than 60% of subjects in both groups.

CONCLUSION

The results suggest that Promogran may accelerate healing in venous leg ulcers and was well tolerated compared with the current standard of care.

The role of oxidised regenerated cellulose/collagen in wound repair: effects in vitro on fibroblast biology and in vivo in a model of compromised healing

Irrespective of underlying chronic wound pathology, delayed wound healing is normally characterised by impaired new tissue formation at the site of injury. It is thought that this impairment reflects both a reduced capacity to synthesize new tissue and the antagonistic activities of high levels of proteinases within the chronic wound environment. Historically, wound dressings have largely been passive devices that offer the wound interim barrier function and establish a moist healing environment. A new generation of devices, designed to interact with the wound and promote new tissue formation, is currently being developed and tested. This study considers one such device, oxidised regenerated cellulose (ORC) /collagen, in terms of its ability to promote fibroblast migration and proliferation in vitro and to accelerate wound repair in the diabetic mouse, a model of delayed wound healing. ORC/collagen was found to promote both human dermal fibroblasts proliferation and cell migration. In vivo studies considered the closure and histological characteristics of diabetic wounds treated with ORC/collagen compared to those of wounds given standard treatment on both diabetic and non-diabetic mice. ORC/collagen was found to significantly accelerate diabetic wound closure and result in a measurable improvement in the histological appearance of wound tissues. As the diabetic mouse is a recognised model of impaired healing, which may share some characteristics of human chronic wounds, the results of this in vivo study, taken together with those relating the positive effects of ORC/collagen in vitro, may predict the beneficial use of this device in the clinical setting.

The Use of Hemostatic Agents and Sealants in Urology

PURPOSE

While hemostatic agents and sealants have long been used in the fields of surgery and urology, confusion persists about their indications for use and the optimal agent choice. We comprehensively defined and evaluated the scientific basis for hemostatic agent and sealant use in urology, and provide a conceptual framework for future research and discussion.

MATERIALS AND METHODS

A MEDLINE search of all available literature concerning hemostatic agents in urology was performed, including topical hemostats, anti-fibrinolytics, fibrin sealants and matrix hemostats. Select references were also chosen from the broader surgical literature. Animal studies, case reports, retrospective and prospective studies, and opinion articles were reviewed.

RESULTS

Hemostatic agents include a wide range of components. Recent literature has focused on fibrin sealants and matrix agents. Two main indications exist for hemostatic agents, including 1) hemostasis and 2) sealant. The best evidence for efficacy and safety exists for hemostasis, especially for nephrectomy and trauma. Newer data highlight urinary tract reconstruction, fistula and percutaneous tract closure, suture line strengthening and infertility as potential uses. Novel drug delivery and tissue engineering are areas with large clinical potential.

CONCLUSIONS

Hemostatic agent use is promising and yet unproven for most conditions currently treated in urology. Hemostasis continues to be the main indication, which is well established. Few trials have examined comparative efficacy among hemostatic agents and further prospective studies are needed to justify additional indications as well as determine the optimal mode of use. Minimally invasive surgery will further drive the use of hemostatic agents and sealants. Cost-effective, evidence based hemostatic agent use will continue to challenge all urologists.

Cost-effectiveness of treating deep diabetic foot ulcers with Promogran in four European countries

OBJECTIVE

This study aimed to estimate the cost-effectiveness of treating non-superficial diabetic foot ulcers with Promogran plus good wound care (GWC) compared with GWC alone in four European countries (France, Germany, Switzerland and UK).

METHODS

An existing Markov-based health economic model of non-superficial diabetic foot ulcers was adapted to incorporate the relative efficacy of Promogran compared with GWC alone as demonstrated in a randomised controlled trial. Treatment with Promogran was modelled for a maximum of three months. Country-specific treatment costs were used to estimate the incremental cost per ulcer-free day gained over 12 months. Some parameter assumptions were changed to assess the sensitivity of the results.

RESULTS

Within the first three months of treatment, 26% of ulcers in the Promogran cohort healed compared with 20.7% in the GWC cohort. Over the 12 months, the average number of months spent in the healed state was 3.41 (GWC) and 3.75 (Promogran). Promogran treatment was found to be cost-saving in all four countries, using year 2000 Euro values.

CONCLUSION

Promogran with GWC may be cost-effective, perhaps even cost-saving, under a wide variety of assumptions for the treatment of neuropathic foot ulcers.

DECLARATION OF INTEREST

This study was funded by Ethicon Gmbh (Johnson and Johnson), Germany.

Barrier agents for adhesion prevention after gynaecological surgery

BACKGROUND

Pelvic adhesion can form as a result of inflammation, endometriosis or surgical trauma. During pelvic surgery, strategies to reduce pelvic adhesion formation may include placing synthetic barrier agents such as oxidised regenerated cellulose, polytetrafluoroethylene or Fibrin sheets between the pelvic structures.

OBJECTIVES

To assess the effect of physical barriers used during pelvic surgery in women of reproductive age on pregnancy rates, pelvic pain, or postoperative adhesion reformation.

SEARCH STRATEGY

We searched the Cochrane Menstrual Disorders and Subfertility Group Trials Register (searched September 2007) which is based on regular searches of MEDLINE, EMBASE, CINAHL, PsycINFO and CENTRAL, plus handsearching of 20 relevant journals and conference proceedings, and searches of several key grey literature sources. In addition, companies were contacted for unpublished trials.

SELECTION CRITERIA

Any randomised controlled trials (RCTs) comparing the use of physical barriers versus no treatment or other physical barriers in the prevention of adhesions in women undergoing gynaecological surgery.

DATA COLLECTION AND ANALYSIS

Review authors assessed trial eligibility and quality.

MAIN RESULTS

Sixteen RCTs were included. Five trials randomised patients while the remainder randomised pelvic organs. Laparoscopy (six trials) and laparotomy (10 trials) were the primary surgical techniques. Indications for surgery included myomectomy (five trials), ovarian surgery (five trials), pelvic adhesions (four trials), endometriosis (one trial), and mixed (one trial). Eleven trials assessed Interceed versus no treatment, two assessed Interceed versus Gore-Tex, one trial assessed Gore-Tex versus no treatment, and one trial assessed Seprafilm versus no treatment. A single trial assessed Fibrin sheet versus no treatment. No studies reported pregnancy or reduction in pain as outcomes. The use of Interceed was associated with reduced incidence of pelvic adhesion formation, both new formation and reformation following laparoscopic surgery or laparotomy. However, this result should be interpreted with caution. Gore-Tex was more effective than no barrier or Interceed in preventing adhesion formation. There was only limited evidence that Seprafilm was effective in preventing adhesion formation following myomectomy and no evidence to support Fibrin sheet.

AUTHORS' CONCLUSIONS

The absorbable adhesion barrier Interceed reduces the incidence of adhesion formation following laparoscopy and laparotomy, but there are insufficient data to support its use to improve pregnancy rates. Gore-Tex may be superior to Interceed in preventing adhesion formation but its usefulness is limited by the need for suturing and later removal. There was no evidence of effectiveness of Seprafilm and Fibrin sheet in preventing adhesion formation.

Adhesion formation of the parietal and visceral peritoneum: an explanation for the controversy on the use of autologous and alloplastic barriers?

OBJECTIVE

To compare formation of adhesions after injury to both parietal and visceral peritoneum and to determine the benefit of autologous transplants and alloplastic barriers in adhesion prevention.

DESIGN

Experimental prospective animal study and prospective randomized clinical study.

SETTING

An academic research environment.

PATIENT(S)

Forty women undergoing laparoscopy for endometriosis treatment.

INTERVENTION(S)

In 60 rats, either the visceral or parietal peritoneum was injured and covered with autologous peritoneal transplants in half of the animals. The formation of adhesions was assessed 21 days postoperatively. In women, adhesions were evaluated 3 months after surgery with or without placement of alloplastic barriers on visceral lesions.

MAIN OUTCOME MEASURE(S)

Adhesions evaluated according to a scoring system.

RESULT(S)

Adhesions after injury of the visceral peritoneum in rats were significantly more severe than those from the parietal peritoneum. Autologous peritoneal transplants led to fewer adhesions especially after serosal injuries. Female volunteers treated with alloplastic barrier material showed less severe adhesions than the control group.

CONCLUSION(S)

The present data indicate that the potential to form adhesions is significantly higher in visceral than in parietal peritoneal lesions. The development of adhesions after injury to the visceral peritoneum could be reduced by a synthetic barrier material.

Intraoperative chemical hemostasis in neurosurgery

Of the various electrical, mechanical, and chemical methods used in neurosurgical hemostasis, the chemical methods are the least well understood. In this review, data concerning seven modern chemical hemostatic agents are presented and special emphasis is placed on their neurosurgical applications. Overall, the general lack of fundamental knowledge concerning these agents at both the scientific and the clinical level was revealed by a relatively small number of publications over the past 4 decades. Several conclusions have been formulated to assist the neurosurgeon in the proper selection and use of these chemical agents. It is our belief that the use of chemical hemostatics in neurosurgery should be based on a thorough knowledge of their mechanism of action and should be supported by continuing laboratory and clinical research.

Reduction of ovarian adhesions by the use of Interceed. Ovarian Adhesion Study Group

OBJECTIVE

To evaluate the efficacy of Interceed (TC7) Absorbable Adhesion Barrier, an oxidized regenerated cellulose fabric, as a barrier to the development of postsurgical ovarian adhesions after surgery involving the ovaries.

METHODS

In a multicenter randomized study, 55 patients with bilateral ovarian disease were treated at initial laparotomy. At the end of the procedure, one ovary was assigned randomly to be wrapped with Interceed and the other was left uncovered. A second-look laparoscopy was performed 10-98 days later to evaluate the occurrence and severity of adhesions and the raw ovarian surface area exposed after lysis of adhesions.

RESULTS

At second-look laparoscopy, 26 of 55 Interceed-treated ovaries were free of adhesions, compared with 14 of 55 untreated control ovaries, a statistically significant difference (P = .028, Fisher exact test). At second-look laparoscopy, ovaries treated with Interceed formed adhesions less extensively (1.66 +/- 0.34 cm2) than did untreated ovaries (2.75 +/- 0.60 cm2) and with a greater reduction of raw ovarian surface area (difference in area differential -1.89 +/- 0.96 cm2; P = .055, paired t test). Adhesion scores at second-look laparoscopy were reduced significantly for ovaries treated with Interceed compared with untreated ovaries (P = .02, Wilcoxon signed-rank test). No adverse events were recorded during the course of the study.

CONCLUSION

Treatment of ovaries with Interceed significantly reduced the occurrence and severity of postsurgical ovarian adhesions.

Effects of physical barriers in prevention of adhesions: an incisional hernia model in rats

BACKGROUND

Adhesion formation between viscera and mesh is almost inevitable following incisional hernia repair with prosthetic mesh. Such adhesions may lead to intestinal obstruction and enterocutaneous fistulae formation and make further laparotomies extremely difficult. Sodium carboxymethylcellulose (SCMC) and Interceed TC7 (oxidized regenerated cellulose) as physical barriers have been shown to be effective in reducing postoperative adhesions.

MATERIALS AND METHODS

To evaluate the effects of SCMC and Interceed TC7, we used an incisional hernia model in rats. A ventral abdominal defect (15 x 25 mm) was created in each of 36 male rats which were then divided into three equal groups. In Group I (control) the defect was repaired with polypropylene mesh (PPM) only; in Group II the defect was repaired after a layer of Interceed TC7 was laid over the viscera with Interceed TC7-covered PPM; in Group III the defect was repaired after a layer of SCMC was laid over the viscera with SCMC-coated PPM. Six of the animals from each group were sacrificed at Postoperative Day 7 and the adhesions were scored. The remaining 6 were sacrificed at Day 30 and histological evaluation was made in addition to the adhesion score.

RESULTS

Animals in the SCMC-treated group developed significantly less adhesions (P = 0.0002) compared with control and Interceed TC7-treated groups. However, histological analysis revealed poor fibroblast proliferation with impaired wound healing in the SCMC group.

CONCLUSION

SCMC prevented adhesion formation but seriously impaired wound healing, and Interceed TC7 was ineffective in preventing adhesion in this model.

Comparison of 2 hemostatic agents for the prevention of postextraction hemorrhage in patients on anticoagulants

OBJECTIVE

The objective of this study was to compare the use of a resorbable oxycellulose dressing with a fibrin adhesive for the prevention of postextraction hemorrhage in patients taking anticoagulants.

STUDY DESIGN

A control group of 26 patients with a preoperative international normalized ratio (INR) in the range of 2.0 to 4.2 had extractions performed with the use of local anesthesia and the socket(s) dressed with a resorbable oxycellulose dressing and sutured with a resorbable suture. The study group with a comparable INR range of 2.1 to 4.1 was treated in a similar manner, except the sockets were dressed with a fibrin adhesive.

RESULTS

No discernible difference in the postoperative outcome with regard to hemorrhage was noted. Postoperative pain was reported more frequently in the group that used a resorbable oxycellulose dressing. Only 1 patient had significant postoperative bleeding.

CONCLUSIONS

This study shows that in patients receiving warfarin whose INR is within the therapeutic range, the fibrin adhesive is as effective as the resorbable oxycellulose dressing in preventing postextraction hemorrhage.

Fibrin sealant improves hemostasis in peripheral vascular surgery: a randomized prospective trial

OBJECTIVE

To evaluate the efficacy and safety of an investigational fibrin sealant (FS) in a randomized prospective, partially blinded, controlled, multicenter trial.

SUMMARY BACKGROUND DATA

Upper extremity vascular access surgery using polytetrafluorethylene (PTFE) graft placement for dialysis was chosen as a reproducible, clinically relevant model for evaluating the usefulness of FS. The FS consisted of pooled human fibrinogen (60 mg/mL) and thrombin (500 NIH U/mL). Time to hemostasis was measured, and adverse events were monitored.

METHODS

Consenting adult patients (n = 48) undergoing placement of a standard PTFE graft were randomized in a 2:1:1 ratio to the treatment group using FS (ZLB Bioplasma AG, Bern, Switzerland), oxidized regenerated cellulose (Surgicel, Johnson & Johnson, New Brunswick, NJ), or pressure. Patients received heparin (3,000 IU IVP) before placement of vascular clamps. If the treatment was FS, clamps were left in place for 120 seconds after the application of study material to permit polymerization. If treatment was Surgicel, clamps were left in place until the agent had been applied according to manufacturer's instructions. If the treatment was pressure, clamps were released as soon as the investigator was ready to apply compression. Immediately after release of the last clamp, the arterial and venous suture lines were evaluated for bleeding. The time to hemostasis at both the venous and arterial sites was recorded.

RESULTS

Significant (P < or =.005) reduction in time to hemostasis was achieved in the FS group. Thirteen (54.2%) patients randomized to FS experienced immediate hemostasis at both suture lines following clamp removal compared to no patients using Surgicel or pressure. Only one patient (7.1%) in the Surgicel group and no patients in the pressure group experienced hemostasis at 120 seconds from clamp removal, compared to 13 (54.2%) patients for FS. Adverse events were comparable in all groups. There were no seroconversions.

CONCLUSIONS

FS achieved more rapid hemostasis than traditional techniques in this peripheral vascular procedure. FS use appeared to be safe for this procedure.

A comparative study of polylactic acid, Gelfoam, and Surgicel in healing extraction sites

The search for a biodegradable material which may be placed in a fresh extraction socket to facilitate healing and prevent localized osteitis is a project which continues to hold much interest for oral surgeons. Polylactic acid is a biodegradable material which appears to have some promise in this area. The present study was devised to compare polylactic acid with two commonly used biodegradable substances and natural healing in order to determine the tissue response and suitability of polylactic acid as a treatment modality in fresh extraction sites. The over-all results were very satisfactory. The polylactic acid was well tolerated and did not interfere with the healing process.

Effect of different barriers of oxidized regenerated cellulose (ORC) on cecal and sidewall adhesions in the presence and absence of bleeding

Adhesion formation after bowel surgery is a significant problem. The objective of this study was to evaluate two adhesion barriers composed of oxidized regenerated cellulose (ORC) in a model of bowel surgery, with and without bleeding. Ceca of female New Zealand White rabbits were abraded with gauze and a 3 x 5 cm patch of peritoneum and underlying muscle was excised from the right sidewall. Animals were randomized to receive no treatment, INTERCEED Barrier (Ethicon, Inc.), or neutralized INTERCEED (nTC7). ORC fabrics were applied to the excision site. Seven days later the percentage of the site and length of cecum with adhesions were estimated. The study was replicated in the presence of blood by nicking small vessels near the site sufficient to saturate the fabrics with blood. With hemostasis, the percentage of the sidewall with adhesions was reduced (p < .01) from 63.2 +/- 14.7% in controls (n = 6) to 4 +/- 2.7% with INTERCEED Barrier (n = 6) and 3 +/- 1.2% (n = 5) with nTC7. With bleeding, however, control (n = 5) levels of adhesions (67 +/- 17.5%) were reduced significantly with nTC7 (5.5 +/- 4%, n = 4; p < .01), but not INTERCEED Barrier (34.2 +/- 18.4%, n = 4). Similar trends were observed when the extent of adherent cecum was examined, since the cecum was the main site of adherence to the sidewall. However in the presence of blood, there was no effect of INTERCEED Barrier on cecal adhesions. We conclude that with hemostasis, both absorbable fabrics of ORC reduced adhesion formation between the injured cecum and abdominal sidewall. The effectiveness of INTERCEED Barrier, but not nTC7, was reduced but not eliminated in the presence of bleeding. This confirms similar observations in models of gynecologic surgery.

Evaluation of hemostatic agents in experimental splenic lacerations

Avitene, Collastat, Gelfoam, and Surgicel were evaluated for their effectiveness in the control of hemorrhage from an experimental splenic laceration. Effectiveness was determined by measuring the amount of blood loss per kilogram of body weight until complete hemostasis was achieved and by determining mortality from hemorrhage. The study group in which Collastat, a collagen hemostatic sponge, was used had the smallest amount of blood loss. This group was also the only one with no deaths from breakthrough bleeding. The degrees of reaction in the spleens of the surviving animals 3 weeks after treatment were not significantly different when each of the various agents were compared. We believe that Collastat is the preferred topical hemostatic agent.

The prevention of postoperative pelvic adhesions: an animal study comparing barrier methods with dextran 70

There are two major approaches to the prophylaxis for adhesions: chemical methods (e.g., dextran) and barrier methods. Theoretically, dextran prevents the formation of adhesions by a surface-coating or hydroflotation effect, whereas the barrier methods either prevent the formation of or mask adhesions by covering and isolating the injured area with an inert substance. This study compared the efficacy of two different concentrations of dextran 70 and various barriers in preventing the formation of adhesions in the female rabbit pelvis. Symmetrical cut and scrape lesions were made on both sides of each rabbit's uterus; for the barrier-treated animals, the lesions on one side were covered with a barrier, and the contralateral side served as a control. The barriers tested were: Gelfilm, Surgicel, Silastic, Gelfoam paste, amnion, peritoneum, and omentum (five rabbits per subgroup). The same cut and scrape lesions were induced in 16 additional rabbits in the chemical group. These rabbits were subsequently treated with 10 ml/kg of intraperitoneal 6% dextran 70 (five rabbits), and 32% dextran 70 (five rabbits), and were compared with six external control rabbits. The severity of the adhesions that formed was graded by a numerical scoring system. The barrier methods tested resulted, generally, in an increased formation of adhesions when a comparison was made with control and with dextran-treated animals. The degree of formation of adhesions in the dextran-treated rabbits did not differ from that in the control animals. The data suggest that the barrier methods actually promote the formation of adhesions whereas the findings with dextran 70 were inconclusive.

A new material for prevention of peritendinous fibrotic adhesions after tendon repair: oxidised regenerated cellulose (Interceed), an absorbable adhesion barrier

In this experimental study, we aimed to examine the ability of absorbable oxidised regenerated cellulose (Interceed, TC-7, Johnson & Johnson, USA) to inhibit the formation of peritendinous fibrotic adhesions after tendon repair in rats. Both Achilles tendons of 23 female Wistar-Albino rats weighing between 350 and 450 grams were cut and repaired. On the right side, Interceed absorbable adhesion barriers were wrapped around the repaired tendon (group I). On the left, the same procedures were applied except for the Interceed wrapping and these were grouped as control (group II). Animals were sacrificed at postoperative day 28 and macroscopic and histological examination was performed. All the animals survived and no tendon rupture was observed. No wound dehiscence, wound infection or exposure of repaired tendons occurred. Macroscopically, there were three (13.1%) tendons without adhesion formation and 20 (86.9%) tendons with inferior adhesion formation in group I; on the other hand, there were 16 tendons (69.5%) with medium grade adhesion formation and seven tendons (30.5%) with severe peritendinous adhesion formation in group II (control group) (p<0.05). Histologically, adhesion formation was absent in 11 tendons (47.8%) and slight in 12 tendons (52.2%) in group I; while in group II, it was slight in two (8.6%), moderate in 15 (65.2%) and severe in six tendons (26.2%) (p<0.05). Sixteen (69.5%) of 23 tendons in group I and 11 (47.8%) of 23 tendons in group II showed no inflammatory reaction (p<0.05). Nineteen (82.6%) tendons in group I and only one tendon in group II showed excellent to good tendon healing (p=0.00). According to our results, we feel that Interceed may have an intraoperative role to play in the reduction of adhesions after surgical tendon repair. This study suggests that absorbable oxidised regenerated cellulose merits further evaluation as a potential treatment to inhibit the formation of peritendinous adhesions. Rigorous and extensive controlled trials should be undertaken on patients undergoing tendon repair with or without this barrier.

Minor oral surgical procedures in patients on oral anticoagulants — a controlled study

BACKGROUND

Patients on therapeutic anticoagulation are at risk of bleeding from minor oral surgical sites. When the anticoagulant regime is modified to prevent the risk of bleeding, this at the same time predisposes the patient to risks of the medical condition for which they are being treated.

METHODS

A total of 70 patients who were on warfarin treatment requiring minor oral surgical procedures were treated in the Oral Surgery Department. A control group of 35 had their warfarin stopped prior to the minor oral surgical procedure. The other 35 formed the study group. Patients with an International Normalized Ratio outside the therapeutic range of 2-4, or with history of liver disease or on drugs affecting liver function were excluded from the study. Any incidences of post-operative bleeding were recorded.

RESULTS

None of the patients in either control or study group had any serious bleeding complications.

CONCLUSION

The data suggest that patients can safely undergo routine minor oral surgical procedures without alterations of their therapeutic anticoagulation regime.

Barrier agents for adhesion prevention after gynaecological surgery

BACKGROUND

Pelvic adhesions can form as a result of inflammation, endometriosis or surgical trauma. During pelvic surgery, strategies to reduce pelvic adhesion formation include placing barrier agents such as oxidised regenerated cellulose, polytetrafluoroethylene or fibrin sheets between the pelvic structures.

OBJECTIVES

To evaluate the effects of barrier agents used during pelvic surgery on rates of pain, live birth and postoperative adhesions in women of reproductive age.

SEARCH METHODS

We searched the following databases in February 2015: the Menstrual Disorders and Subfertility Group (MDSG) Specialised Register of Controlled Trials, MEDLINE, EMBASE, CINAHL, PsycINFO, the Cochrane Central Register of Controlled Trials (CENTRAL) and trial registries. We handsearched relevant journals, conference proceedings and grey literature sources and we contacted pharmaceutical companies for information.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of the use of barrier agents compared with other barrier agents, placebo or no treatment for the prevention of adhesions in women undergoing gynaecological surgery.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for eligibility and risk of bias and extracted the data. We calculated odds ratios (ORs) or mean differences (MD) with 95% confidence intervals (CIs) using a fixed effect model. The overall quality of the evidence was assessed using GRADE (Grades of Recommendation, Assessment, Development and Evaluation) methods.

MAIN RESULTS

Eighteen RCTs (1262 women) were included. Six RCTs randomised women; the remainder randomised pelvic organs. Laparoscopy (eight RCTs) and laparotomy (10 RCTs) were the primary surgical techniques. Indications for surgery included myomectomy (six RCTs), ovarian surgery (five RCTs), pelvic adhesions (five RCTs), endometriosis (one RCT) and mixed (one RCT). The sole indication for surgery in three of the RCTs was infertility. Twelve RCTs reported commercial funding; the rest did not state their source of funding.No studies reported either of our primary outcomes of pelvic pain and live birth. Oxidised regenerated cellulose (Interceed) versus no treatment at laparoscopy or laparotomy (13 RCTs)At second-look laparoscopy oxidised regenerated cellulose at laparoscopy was associated with reduced incidence of de novo adhesions (OR 0.50, 95% CI 0.30 to 0.83, three RCTs, 360 participants, I(2) = 75%, very low-quality evidence) and of re-formed adhesions (OR 0.17, 95% CI 0.07 to 0.41, three RCTs, 100 participants, I(2) = 36%, low quality evidence).At second-look laparoscopy no evidence was found of any difference between the groups in the incidence of de novo adhesions after laparotomy (OR 0.72, 95% CI 0.42 to 1.25, one RCT, 271 participants, I(2) = 41%, low-quality evidence). However, the incidence of re-formed adhesions was lower in the intervention group (OR 0.38, 95% CI 0.27 to 0.55, six RCTs, 554 participants, moderate-quality evidence). Expanded polytetrafluoroethylene (Gore-Tex) versus no treatment at gynaecological surgery (one RCT) The evidence suggested that at second-look laparoscopy expanded polytetrafluoroethylene was associated with a reduction in new adhesion formation (OR 0.17, 95% CI 0.03 to 0.94, one RCT, 42 participants, low-quality evidence). Expanded polytetrafluoroethylene (Gore-Tex) versus oxidised regenerated cellulose (Interceed) at gynaecological surgery (two RCTs)One RCT found no difference between the groups at second-look laparoscopy in the incidence of de novo adhesions (OR 0.93, 95% CI 0.26 to 3.41, 38 participants, very low-quality evidence). A second RCT suggested that the expanded polytetrafluoroethylene group had a lower adhesion score (out of 11) (MD -3.79, 95% CI -5.12 to -2.46, 62 participants, very low-quality evidence) and a lower risk of re-formed adhesions (OR 0.13, 95% CI 0.02 to 0.80, 23 participants, very low-quality evidence). This last finding was sensitive to choice of effect estimate and no longer suggested a difference between the groups when a risk ratio was calculated (RR 0.36, 95% CI 0.13 to 1.01). Sodium hyaluronate and carboxymethylcellulose (Seprafilm) versus no treatment at gynaecological surgery (one RCT)Sodium hyaluronate and carboxymethylcellulose was associated with a lower adhesion score (out of 4) at second-look laparoscopy (MD 0.49, 95% CI 0.53 to 0.45, one RCT, 127 participants, moderate-quality evidence). Fibrin sheet versus no treatment at laparoscopic myomectomy (one RCT)There was no evidence of a difference between the groups in the incidence of de novo adhesions at second-look laparoscopy (OR 1.20, 95% CI 0.42 to 3.41, one RCT, 62 participants) or in adhesion score (out of 4) (MD 0.14, 95% CI -0.67 to 0.39, one RCT, 48 participants, low-quality evidence).Fourteen of the 18 RCTs reported adverse events. No events directly attributed to adhesion agents were reported.

AUTHORS' CONCLUSIONS

We found no evidence on the effects of barrier agents used during pelvic surgery on either pain or fertility outcomes in women of reproductive age.Low quality evidence suggests that oxidised regenerated cellulose (Interceed), expanded polytetrafluoroethylene (Gore-Tex) and sodium hyaluronate with carboxymethylcellulose (Seprafilm) may all be more effective than no treatment in reducing the incidence of adhesion formation following pelvic surgery. There is no conclusive evidence on the relative effectiveness of these interventions. There is no evidence to suggest that fibrin sheet is more effective than no treatment. No adverse events directly attributed to the adhesion agents were reported. The quality of the evidence ranged from very low to moderate. The most common limitations were imprecision and poor reporting of study methods. Most studies were commercially funded, and publication bias could not be ruled out.