Sealant System Research Articles

Study on the bowel preparation methods before hemorrhoidectomy using LigaSure vessel sealant system

Objective To approach the effect of Hemorthoidectomy using LigaSure vessel sealantsystem with different bowel preparation means.Methods Seventy-eight patients with hemorrhoids were divided into three groups which are the Epsom salt group(21 cases),the Kaiselu group(32 eases),and the no bowel preparation group(25 cases)according to their operation's day.The observation items are the satisfaction rate of the operative doctors,the degree of comfort to patient,the severe pain duration time and scores,the first defecation time and the pain scores after operation,and the intention time．Results 61.90％patients in Epsom salt group felt uncomfortable but did not influence the life.6.25％patients in Kaiselu group felt uncomfortablebut did not influence the life and 6.25％patients felt uncomfortable and influence the life.The degree of comfort of patient Was significant difference in three groups(H=13.39,P=0.001 2).There were no significant differences in other observation items among three groups(P>0.05).Condusions There are similar effect in three groups with Hemorrhoidectomy patient using LigaSure vessel sealant system,but in the degree of comfort to patients,the no bowel preparation means is the hest choice for patient.If the doctor order to do bowel preparation for patient,the bowel preparation using Kaiselu is better than that using Epsom salt. Key words: Bowel preparation; Hemorrhoidectomy; Liga Sure vessel sealant system

Overcoming the Weak Link in Cemented Isolation

This article, written by Assistant Technology Editor Karen Bybee, contains highlights of paper SPE 110523, "Overcoming the Weak Link in Cemented Hydraulic Isolation," by N. Moroni and N. Panciera, Eni E&P; A. Zanchi, Stogit; and C.R. Johnson, SPE, S. LeRoy- Delage, SPE, H. Bulte-Loyer, SPE, S. Cantini, SPE, E. Belleggia, SPE, and R. Illuminati, SPE, Schlumberger, prepared for the 2007 SPE Annual Technical Conference and Exhibition, Anaheim, California, 11-14 November. The paper has not been peer reviewed. The full-length paper describes a unique isolation solution based on a responsive cement system with intrinsic self-healing properties that are activated automatically upon hydrocarbon exposure. Activation occurs whenever the integrity of the cement sheath is compromised. The new sealant system rapidly forms a complete barrier by swelling and continues to reseal should further damage occur. The technical advantages of this sealant have been demonstrated through successful field tests. New Sealant System In recent years, the well-cementing industry has begun to concentrate on the ability of set cement to provide zonal isolation throughout the lifetime of the well. Even if the cement has been placed properly and initially provides a competent hydraulic seal, zonal isolation could be compromised as a result of changing downhole conditions over the lifetime of the well. Studies have shown that the main causes of cement-sheath damage are stresses induced by varying downhole conditions. The loss of zonal isolation after cement has hardened can be a result of mechanical failure of the set cement itself or debonding of the casing from the cement or the cement from the formation. Several solutions have been developed and applied successfully in field applications. One current method to improve cement resistance to physical stresses involves the addition of fibrous or ribbon-like materials to increase the toughness of the cement matrix. While these methods increase the resistance of the cement matrix to physical stresses, none of these approaches can accommodate problems that occur once the cement sheath has actually failed and becomes permeable. The objective of the self-healing cement (SHC) system is to pro-vide long-term zonal isolation with a cement-based system that incorporates self-healing additives. Hydrocarbons activate the self-healing additives whenever the integrity of the cement sheath is compromised (e.g., cracks and micro-annuli), and the cement matrix would seal the leak path through a swelling mechanism. Application of this responsive sealant targets a wide range of wells to mitigate risks of future cement-sheath degradation through unplanned well events and operations, and to ensure long-term zonal isolation throughout the productive and abandoned periods. The versatile sealant can be strategically placed, from surface to total depth of the well in any string of the well, to provide an effective long-term seal.

Application of a hydrogel sealant improves watertight closures of duraplasty onlay grafts in a canine craniotomy model

The authors evaluated whether a polyethylene glycol-based hydrogel sealant system improved dural closures with collagen-based duraplasty onlay grafts. Dural defects 1.5 cm in diameter were created in 12 canines and repaired with one of two commercially available duraplasty onlay products. In six animals, hydrogel was applied onto the dural onlays, and the other six animals underwent duraplasty only. Before bone flap replacement, watertight closure was assessed. Before the animals were killed, the craniotomy was reopened, adhesions were rated by a neurosurgeon blinded to the treatment groups, and dural integrity was assessed using pressure testing. The animals that received the hydrogel sealant in addition to the duraplasty withstood intraoperative Valsalva maneuvers up to 20 cm H2O without cerebrospinal fluid (CSF) leakage. The duraplasty-only animals leaked CSF at spontaneous pressures (p = 0.0022). Postoperatively, all six duraplasty-only dogs developed CSF subcutaneous accumulations, compared with only one (16.7%) dog who underwent hydrogel application (p = 0.0152). At the time of harvesting (8 weeks after implantation), duraplasty-only dogs had extensive scarring between the bone flap and the dura mater (median adhesion score 4, range 3-4). The animals receiving hydrogel showed minimal scarring (median adhesion score 0.5, range 0-2). In hydrogel-treated dogs, the mean adhesion score was 82.6% lower than the scores in duraplasty-only animals (p = 0.0043). In animals receiving hydrogel, the mean dural leak pressure was 56.8 +/- 2.5 cm H2O compared with 9.8 +/- 3.8 cm H2O in duraplasty-only dogs (p = 0.0392). Application of the hydrogel was not associated with neurotoxicity, delayed healing, degenerative changes, or increased dura-cortex adhesions. The hydrogel sealant applied to collagen-based dural grafts significantly reduced CSF leakage and functioned as an adhesion barrier. Such technology could be an important tool for cranial surgery.

Which sealant system should I use?

As well as using Medline, Embase and the Cochrane library to source studies, a search was made by hand of reference lists of the selected articles and dental conference proceedings, and experts were contacted to identify any unpublished research, irrespective of language in each case. Two reviewers independently selected the studies. The latter were chosen if randomised, quasi-randomised or controlled clinical trials that used split-mouth design or were parallel group studies, and which compared different available resin-based sealants (RBS) on permanent molars or compared different clinical protocols for the same RBS. Studies comparing RBS with ultraviolet-activated sealants, glass ionomer cements (GIC) or resin-reinforced GIC sealants were not considered and neither were resins indicated for restoration, except for flowable resins. Data was extracted by two reviewers independently. Data synthesis was conducted using the program RevMan (version 4.2; Cochrane Collaboration, Dublin, Ireland). Relative risks (RR) were calculated because the outcome was a dichotomous variable; variance was expressed using 95% confidence intervals (CI). Meta-analysis was carried out if the studies were homogeneous enough and subgroup analyses were conducted if necessary. The heterogeneity of the results was assessed using chi-squared tests, and sensitivity analyses were performed excluding unpublished studies or poor-quality studies. A total of 31 studies met the inclusion criteria. Sixteen studies compared two different types of RBS, those that were light-cured (LRBS) or auto-polymerised (ARBS), with fluoride-containing sealants (FRBS). Seventy-five per cent were split-mouth design studies. Seven studies compared LRBS with ARBS and nine studies compared LRBS with FRBS. The retention rate of ARBS and LRBS did not differ significantly. LRBS had a significantly higher retention rate than FRBS at 48 months (RR, 0.80; 95% CI, 0.72-0.89). Only 15 studies of limited quality focused on the best clinical protocol to adopt for sealant application. Only FRBS had a lower retention rate than ARBS or LRBS. This review did not allow the best clinical procedure to be determined because of insufficient studies. Well-designed randomised clinical trials are still needed that focus on sealant retention and consider different clinical procedures, particularly new enamel preparation techniques such as air-abrasion or sono-abrasion.

Effects of Mixture of Fibrin-Fibronectin Sealant System and Calcium Carbonate in Periodontal Intrabony Defects

This study evaluated the effects of mixture of fibrin-fibronectin sealant system(FFSS) and calcium carbonate(CC) in periodontal intrabony defects. Thirty six sites with two or three wall intrabony defect were used. 14 defects treated with periodontal flap surgery were assigned as the control group. 11 defects treated with CC implantation were designed as experimental group 1 and 11 defects, treated with CC and FFSS implantation as experimental group 2. The control and experimental groups all achieved statistically significant improvements in probing depth and clinical attachment level from the baseline (P<0.01). In mean postsurgery probing depth and gingival recession reduction, there were no statiscally significant differences between the experimental groups and the controls. However, mean postsurgery clinical attachment levels of both experimental groups improved significantly more than that of the controls. As a result, we suggest that mixture of FFSS and CC can be used effectively in intrabony defect as osteoconductive materials.

The Use of a Hydrogel Sealant on Flexor Tendon Repairs to Prevent Adhesion Formation

The prevention of peritendinous adhesions after zone II flexor tendon repair poses a significant challenge to hand surgeons. This study evaluates a hydrogel sealant (FocalSeal-L) as a barrier to peritendinous adhesion formation. The deep flexors of toes 2 through 4 were divided and repaired in 30 chickens. Chickens were randomized to tendon repair with (n = 15) or without (n = 15) FocalSeal-L. Each group was further randomized to have their tendons studied postoperatively at 3 (n = 10), 6 (n = 10), or 12 (n = 10) weeks. Histologic evaluation revealed decreased peritendinous adhesion formation in the FocalSeal-L group. Biomechanical analysis demonstrated a decrease in work of flexion in the FocalSeal-L group that was most pronounced at 6 weeks (P = 0.0020). There was no significant difference in breaking strength. Apparently, an effective barrier to peritendinous adhesion formation, this sealant system is easy to use, biocompatible, and bioresorbable. In addition, it is not bulky or restrictive to tendon glide.

Effects of mixture of fibrin-fibronectin sealant system and calcuim carbonate in periodontal intrabony defects

Effects of mixture of fibrin-fibronectin sealant system and calcuim carbonate in periodontal intrabony defects

The Great Unsealing: A Perspective on Portland Cement Concrete Joint Sealing

The general mission of most transportation agencies is to ensure a customer focus in the development and operation of a safe and efficient transportation system. The customers desire comfort, convenience, safety, and cost-effectiveness in a transportation system. Agency research must have the objectives of addressing customer-related issues and measuring benefits of importance to them. Accordingly, any joint and sealant research must answer the questions, Why do we seal? and Is it cost-effective? Joint and sealant studies of portland cement concrete (PCC) pavements must address whether joint sealing enhances total pavement performance and is cost-effective, and, if so, what sealant system should be used. The Wisconsin Department of Transportation (WisDOT) has been studying the effect of PCC joint/crack sealing on total pavement performance for 50 years. By 1967 there was substantial documentation that filling and refilling of contraction joints had no beneficial effect on pavement performance. By 1984, it was concluded that pavements with unsealed joints had better overall performance (distress, ride, materials integrity) than pavements with sealed joints. In 1990, WisDOT passed a policy eliminating all PCC joint sealing, in new construction and maintenance. This "no-seal" policy has saved Wisconsin $6,000,000 annually with no loss in pavement performance and with increased customer safety and convenience. The entire PCC sealing issue is beginning to be addressed at the national level, ensuring no false assumptions and with the customer’s needs in view.

Sealing and resealing of joints in buildings

Sealants play a vital role in joints in maintaining the weather-tightness of buildings and engineering structures. This paper outlines the nature of joint movements and the requirements of sealants to fulfil this role. Aspects of economics, joint design, sealant system selection and joint preparation are then discussed, both in the context of new sealing and resealing. Important new guidance is also given in terms of resealing of joints. Finally, the requirements of a detailed contract specification are outlined.

Lendrum (-MSB) Staining for Fibrin Identification in Sealed Skin Grafts

The significance and effect of fibrin sealant systems for woundhealing are still unknown, because of the use of insufficient, conventional staining methods for the demonstration of the fibrin components used by sealant systems. From 21 patients with extensive burns of 2nd and 3rd degree biopsies of the skin were obtained during consecutive operations to cover the defect of the skin with split-thickness skin grafting. In the present paper morphological results concerning the demonstration of fibrin components and morphological differences in woundhealing of sealed and unsealed skin grafts are presented using Lendrum (-MSB) staining. With this staining method it is possible to identify exogenous fibrin components of the sealant system and to differentiate between fresh and older fibrin components, due to colour changes depending on time.

Sealants revisted: an update of the effectiveness of pit-and-fissure sealants.

The first sealant clinical trials used cyanoacrylate-based materials. These were replaced by dimethacrylate-based products which were marketed. A major difference between marketed sealants is their method of polymerization. First-generation sealants were initiated by ultraviolet light, second-generation sealants are autopolymerized, and third-generation sealants use visible light. Over time, clinical retention was found to be greater for second generation as compared with first-generation sealants. Five to 7 years after initial application the pits and fissures of approximately one third of teeth treated with first-generation sealants were fully protected as compared with two thirds of the teeth treated with second-generation sealants. First-generation, ultraviolet light initiated, sealants are no longer marketed. Clinical reports indicate that retention is similar for second- and third-generation systems, but longer clinical evaluations are necessary. A recent innovation is the addition of fluoride to sealants. Fluoride release to the saliva from a fluoride sealant system is rapid, but clinical studies are needed to determine if the fluoride addition improves caries inhibition.

Four years' experience with fibrin sealant in thoracic and cardiovascular surgery

A single-donor fibrin sealant system was used in 689 thoracic and cardiovascular surgical procedures over the 4-year period between April 1, 1985, and March 31, 1989. An excellent overall success rate (646/689, 94% effective) was achieved with specific applications, including reduction of leakage of air (29/33, 88% effective), blood (595/634, 94% effective), and fluid (14/14, 100% effective), as well as positioning of anatomical structures such as coronary bypass grafts (8/8, 100% effective). Application methods included use of spray bottles (477/497, 96% effective), syringes (165/186, 89% effective), and a Silastic cannula through the flexible fiber-optic bronchoscope (4/6, 67% effective). The system was used in a wide variety of cardiac, pulmonary, esophageal, and vascular procedures to seal staple lines, suture lines, anastomoses, conduits, fistulas, and raw surfaces. No complications with this single-donor system secondary to blood-borne disease have been documented. Overall infection occurred at a nominal rate (16/689, 2%). Thus, fibrin sealant has been a useful tool to control the leakage of air, blood, and fluid during a wide variety of thoracic and cardiovascular procedures and may be of benefit to other surgeons.

Effects of fibrin sealant on incorporation of autograft and xenograft tendons within bone tunnels

The anterior and posterior tibialis tendons in both hindlimbs of six adult dogs were rerouted through extraarticular bone holes created in the distal tibial metaphysis. Xenograft tendons of comparable dimensions were used in an additional six dogs. Fibrin Sealant System (FSS) was applied to the bone tendon interface in the right legs, whereas the left legs were used as controls. The animals were sacrificed at 5, 9, and 28 days. Coronal sections of the distal tibias were studied histologically and microangiographically. The autogenous tendons appeared to incorporate by means of fibrous ingrowth, whereas spicules of new bone in direct opposition to the xenografts were observed at 28 days. FSS promoted organization and maturation of fibrous connective tissue surrounding both implants at early sacrifice but did not appreciably alter incorporation at 28 days.

Morphometric studies on wound healing after systemic administration of adriamycin and local application of fibrin sealant: Application of a new wound healing model using spongiosa implants

For investigations on the development of regenerative granulation tissue in wound healing a new model using bone spongiosa ("Kieler Spongiosa") implants is presented. Particular attention was devoted to developing a model which permits studies on wound healing without disturbance by foreign body reaction and infections. Two test groups of rats received four blocks of "Kieler Spongiosa" each in a symmetrical fashion in a paramedian region underneath the dorsal skin. The spongiosa blocks had previously been treated with glutaraldehyde to achieve cross-linkage of the collagenous structures of the surfaces of the spongiosa trabeculae. After one week (group 1) and two weeks (group 2) the animals were sacrificed. The spongiosa blocks were removed, fixed and evaluated in layered serial sections after decalcification. Two blocks which had been removed randomly from the back and front served for morphometric determination of the total volume of bony substance and the developed granulation tissue. Moreover, the cellular composition of the granulation tissue was morphometrically examined with regard to its content of capillaries, granulation tissue cells and inflammatory cells. The two other blocks were examined for DNA and hydroxyproline content of granulation tissue. Comparison of the two experimental groups yielded marked differences in spongiosa space infiltrated by granulation tissue and its composition. Our model was used to assess the influence of systemic administration of adriamycin and/or local application of a fibrin sealant system on granulation tissue formation and its morphologic structure.(ABSTRACT TRUNCATED AT 250 WORDS)

Methods of fibrin seal application.

With the help of various tests (tensile strength, distribution in cancellous bone blocks, thrombin release from standard clots), the importance of mixing the solutions of the fibrin sealant system was demonstrated and an optimal mixing ratio of one to one was identified. Different application techniques are discussed. The spraying technique, which produces rapid hemostasis, is reviewed in detail. As further advantage, the resulting sealant film is thin. This appears important for promoting wound healing.

Segmental Concrete Liner for Soft Ground Tunnels

Concrete is presented as a low-cost material for use as a sole tunnel liner material in future mass transit tunnel projects. Existing mass transit tunnels throughout the world which have used concrete liners are presented. A systems summary is given which outlines numerous factors that must be considered for implementation of concrete as a sole tunnel liner material. Various concretes and liner sealant systems are presented as well as past and current research efforts directed toward greater use of concrete in future transit tunnel projects. Many aspects for consideration in a sealant system test verification program are also presented.

Development of an Effective Poured-in-Place Sealant for Concrete Joints

Some years ago, Thiokol began an active program to determine the physical properties and aging characteristics needed for an effective poured-in-place joint sealant system. Initial investigations were carried out in the field to determine the types of problems that occurred. Our ultimate goal was a series of laboratory tests that would screen sealants. Economics dictated this approach, provided laboratory data was a relative measure of field performance. Periodic photographs of both the commercial and laboratory sealants, which were installed in the field, comprised an accurate record of the types of sealant failures that developed.