Solution blow spun polymer: A novel preclinical surgical sealant for bowel anastomoses

BACKGROUND

Solution blow spinning is a technique for depositing polymer fibers with promising potential use as a surgical sealant. This study assessed the feasibility and efficacy of solution blow spun polymer (BSP) for sealing bowel perforations in a mouse model of partial cecal transection. We then evaluated its use for reinforcing a surgical anastomosis in a preclinical piglet model.

METHODS

Three commercially available surgical sealants (fibrin glue, polyethylene glycol (PEG) hydrogel, and cyanoacrylate) were compared to BSP in the ability to seal partially transected cecum in mice. For anastomosis feasibility testing in a piglet model, piglets were subjected to small bowel transection with sutured anastomosis reinforced with BSP application. Outcome measures included anastomotic burst pressure, anastomotic leak rate, 14-day survival, and complication rate.

RESULTS

For the mouse model, the survival rates for the sealants were 30% for fibrin glue, 20% for PEG hydrogel, 78% for cyanoacrylate, and 67% for BSP. Three of 9 mice died after BSP administration because of perforation leak, failure to thrive with partial obstruction at the perforation site, and unknown causes. All other mice died of perforation leak. The mean burst pressure at 24h was significantly higher for BSP (81mm Hg) when compared to fibrin glue (6mm Hg, p=0.047) or PEG hydrogel (10mm Hg, p=0.047), and comparable to cyanoacrylate (64mm Hg, p=0.91). For piglets, 4 of 4 animals survived at 14days. Mean burst pressures at time of surgery were 37±5mm Hg for BSP and 11±9mm Hg for suture-only controls (p=0.09).

CONCLUSIONS

Solution blow spinning may be an effective technique as an adjunct for sealing of gastrointestinal anastomosis. Further preclinical testing is warranted to better understand BSP properties and alternative surgical applications.

New materials in embolizations

Percutaneous, catheter-directed embolotherapy is an established interventional technique for the management of many vascular disorders. For more than three decades, typical embolization devices included macro and microcoils, polyvinyl alcohol microparticles, glue and certain liquids such as absolute alcohol. In the past decade, however, several new embolic devices and refinements of existing embolic devices have arrived on the market and a number of clinical studies have demonstrated their added value. In this review article, these new embolic devices and their typical indications will be discussed, as well as the results of studies involving the embolic devices.

Novel management of an isolated comminuted cricoid cartilage fracture

Laryngeal trauma is a rare occurrence that can result in significant morbidity and mortality. Isolated cricoid cartilage fractures are exceedingly rare, and their treatment is highly variable. We describe a case of an isolated comminuted, uncalcified cricoid cartilage fracture in a 34-year-old man that responded well to novel management with suture and 2-octylcyanoacrylate tissue adhesive fixation intraoperatively and topical ciprofloxacin/dexamethasone applied to the airway postoperatively. We discuss the novel application of cyanoacrylate glue in laryngeal trauma and the potential benefits of topical ciprofloxacin/dexamethasone application to the airway.

Sutureless Lamellar Corneoscleral Patch Graft With Fibrin Sealant for Limbal Dermoid Removal

A 2-year-old boy with Goldenhar syndrome had a limbal dermoid removed and covered with a lamellar corneoscleral patch graft that was attached with fibrin glue and no sutures. The graft healed and attached well. A sutureless technique is beneficial due to decreased scarring and chance of infection.

Histological Benefits of Sealants in Tracheal Lesions in Wistar Rats

INTRODUCTION

The purpose of our study was to compare the effect, on the inflammatory response and fibrosis formation, of four commercially available sealant products applied on an injured trachea in a Wistar rat population.

MATERIALS AND METHODS

We compared four different sealants: cyanoacrylate, fibrin/thrombin, albumin/glutaraldehyde, and polyethylene glycol-based hydrogel (PEG). Rats were organized into six groups of similar size. Four of them were experimental, one was a baseline control group (BCG), and the sixth one was a reference control group (RCG). The RCG and experimental groups underwent the same surgical intervention with tracheal puncture, but no sealant was applied in the RCG. The BCG underwent the same cervical and peritracheal dissection without tracheal puncture. Rats were euthanized after eight weeks.

RESULTS

The operation was performed on 54 rats, of which 12 died, leaving a final sample of 42 rats. Macroscopic analysis revealed no superficial tracheal or vascular fistulas, nor signs of local abscess. Although the groups treated with cyanoacrylate, fibrin/thrombin, and albumin/glutaraldehyde showed some degree of fibrosis, the treated area of the PEG group showed neither inflammatory nor scar signs. Microscopic assessment of the BCG and RCG showed no remarkable findings. With the exception of the PEG group, which had a light fibrosis and poor inflammatory response as did the BCG and RCG groups, the other groups showed varying degrees of fibrosis and cicatrization.

CONCLUSION

Our study showed that the group treated with PEG had a mild inflammatory and fibrotic response, which is useful in tracheal or tracheobronchial surgical procedures. However, groups treated with cyanoacrylate, fibrin/thrombin, and albumin/glutaraldehyde showed fibrosis and cicatrization.

Comparison of 2-Ethyl-Cyanoacrylate and 2-Butyl-Cyanoacrylate for Use on the Calvaria of CD1 Mice

Short-chain cyanoacrylates (SCCA), such as ethyl-2-cyanoacrylate (KrazyGlue, Aron Alpha, Columbus, OH) are commonly used as commercial fast-acting glues. Although once used in clinical medicine as skin adhesives, these products caused tissue toxicity and thus their use in live tissue was discontinued. SCCA were replaced by longer-chain versions (LCCA), such as butyl-cyanoacrylate (Vetbond, 3M, St Paul, Minnesota), which were found to be less toxic than the short-chain formulations. Some researchers prefer to use SCCA due to the belief that they create a stronger bond than do the longer-chain counterparts. In survival surgeries, we compared the bone thickness, bone necrosis, fibrosis, inflammation, and bone regeneration in the calvaria of control (naïve), surgery-only, SCCA-treated, and LCCA-treated mice (n = 20 per group). At 1 and 14 d after surgery, all mice except those treated with SCCA showed statistically similar bone measurements to those of the naive control group. The SCCA group had significantly less bone regeneration than did all other groups. These results suggest that the application of SCCA causes bone damage resulting in the loss of bone regeneration. This finding may assist investigators in choosing a tissue glue for their studies and may support the IACUC in advocating the use of pharmaceutical-grade tissue glues.

Poloxamer bioadhesive hydrogel for buccal drug delivery: Cytotoxicity and trans-epithelial permeability evaluations using TR146 human buccal epithelial cell line

A salbutamol sulfate (SS)-Poloxamer bioadhesive hydrogel specially developed for buccal administration was investigated by studying interactions with TR146 human buccal epithelium cells (i.e. cellular toxicity (i) and trans-epithelial SS diffusion (ii)). The assessment of cell viability (MTT, Alamar Blue), membrane integrity (Neutral Red), and apoptosis assay (Hoechst 33342), were performed and associated to Digital Holographic Microscopy analysis. After the treatment of 2h, SS solution induced drastic cellular alterations that were prevented by hydrogels in relation with the concentrations of poloxamer and xanthan gum. The formulation containing P407 19%/P188 1%/Satiaxane 0.1% showed the best tolerance after single and multiple administrations and significantly reduced the trans-epithelial permeability from 5.00±0.29 (×10(3)) (SS solution) to 1.83±0.22 cm/h. Digital Holographic Microscopy images in good agreement with the viability data confirmed the great interest of this direct technique. In conclusion, the proposed hydrogels represent a safe and efficient buccal drug delivery platform.

Elastic sealants for surgical applications

Sealants have emerged as promising candidates for replacing sutures and staples to prevent air and liquid leakages during and after the surgeries. Their physical properties and adhesion strength to seal the wound area without limiting the tissue movement and function are key factors in their successful implementation in clinical practice. In this contribution, the advances in the development of elastic sealants formed from synthetic and natural materials are critically reviewed and their shortcomings are pointed out. In addition, we highlight the applications in which elasticity of the sealant is critical and outline the limitations of the currently available sealants. This review will provide insights for the development of novel bioadhesives with advanced functionality for surgical applications.

Lung Sealing with the Sandwich-Technique: A New Surgical Method to Deal with the Emphysematous Lung

The persistent air leak is a common and sometimes difficult to manage complication after major pulmonary resections. Especially in cases with lung emphysema spontaneous sealing of the lung surface under conservative therapy can be prolonged or even fail and a reoperation to close the damaged visceral pleura might be necessary. An ideal surgical solution to deal with this problem is not known, all of the techniques have advantages but also limitations and additional operations should be avoided in this group of frail patients. In this paper a new surgical method to seal the lung surface is presented based on two exemplary cases and our clinical experience. Basically, two stripes of fleece bounded fibrin based sealant are put on the visceral pleura parallel to the wound, which will be then closed by multiple stitches of absorbable suture line inserted through the stripes. Afterwards, a second layer of the same sealant will be placed over it to cover the suture with a narrow overlapping in all directions to the adjacent visceral pleura (Sandwich-Technique). In our experience, this technique can be used to successfully prevent or treat persistent air leaks especially in patients with lung emphysema in whom otherwise treatment options are limited.

ABBREVIATIONS

VATS = video-assisted thoracoscopic surgery POD = postoperative day LVRS = lung volume reduction surgery FEV1 = forced expiratory volume in the first second DLCO = diffusing capacity of the lung for carbon monoxide.

Shear lag sutures: Improved suture repair through the use of adhesives

Suture materials and surgical knot tying techniques have improved dramatically since their first use over five millennia ago. However, the approach remains limited by the ability of the suture to transfer load to tissue at suture anchor points. Here, we predict that adhesive-coated sutures can improve mechanical load transfer beyond the range of performance of existing suture methods, thereby strengthening repairs and decreasing the risk of failure. The mechanical properties of suitable adhesives were identified using a shear lag model. Examination of the design space for an optimal adhesive demonstrated requirements for strong adhesion and low stiffness to maximize the strength of the adhesive-coated suture repair construct. To experimentally assess the model, we evaluated single strands of sutures coated with highly flexible cyanoacrylates (Loctite 4903 and 4902), cyanoacrylate (Loctite QuickTite Instant Adhesive Gel), rubber cement, rubber/gasket adhesive (1300 Scotch-Weld Neoprene High Performance Rubber & Gasket Adhesive), an albumin-glutaraldehyde adhesive (BioGlue), or poly(dopamine). As a clinically relevant proof-of-concept, cyanoacrylate-coated sutures were then used to perform a clinically relevant flexor digitorum tendon repair in cadaver tissue. The repair performed with adhesive-coated suture had significantly higher strength compared to the standard repair without adhesive. Notably, cyanoacrylate provides strong adhesion with high stiffness and brittle behavior, and is therefore not an ideal adhesive for enhancing suture repair. Nevertheless, the improvement in repair properties in a clinically relevant setting, even using a non-ideal adhesive, demonstrates the potential for the proposed approach to improve outcomes for treatments requiring suture fixation. Further study is necessary to develop a strongly adherent, compliant adhesive within the optimal design space described by the model.

The use of "2-octyl cyanoacrylate" as skin adhesive in pediatric and congenital cardiac surgery

AIM

The aim of this paper was to evaluate the safety and cost-effectiveness of "2-octyl-cyanoacrylate" as skin adhesive in congenital heart surgery.

METHODS

From April 2010 to December 2011, we collected data from 300 patients who underwent cardiac surgery for congenital heart disease. We divided our population into 3 groups: group-1 (N.=100):"2-octyl-cyanoacrylate" has been used to replace the intra-dermal suture line; group-2 (N.=100):"2-octyl-cyanoacrylate" has been utilized as a barrier ("add-on measure") in addition to the intra-dermal suture line, group-3 (N.=100) with a standard intra-dermal suture line.

RESULTS

Median age of patients was 1.36 years. One-hundred and thirty-nine patients were younger than 12 months and 56 older than 16 years. There were 11 wound dehiscence (3.6%) (2 in group-1 and 9 in group-3, P=0.001) and 1 superficial wound infection (group-1). Six patients (2%) required surgical wound revision (2 in group-1 and 4 in group-3, P=NS). Wound complication was significantly associated to delayed sternal closure (3/12 patients, 25% versus 13/288 patients, 4.5%) (P=0.04). Median cost (intra-/postoperative) for wound treatment was lower in group-1 and 2 (19±5.5 and 23.9±7.4 € respectively) when compared to Group-3 (26.7±3.2) (P<0.0001).

CONCLUSION

The use of "2-octyl-cyanoacrylate" proved to be safe and effective; the "add-on measure" strategy provided the best cost-effective solution.

No-needle, single-visit adult male circumcision with Unicirc: a multi-centre field trial

Background

Voluntary medical male circumcision (VMMC) is a priority HIV preventive intervention. Current adult circumcision methods need improvement.

Methods

Field trial in 3 primary care centres. Minimally invasive VMMC using the Unicirc instrument following topical lidocaine/prilocaine anesthetic. Men were followed up at 1 and 4 weeks.

Results

We circumcised 110 healthy volunteers. Two men complained of transient burning pain during circumcision, but none required injectable anaesthesia. Median blood loss was 1ml and median procedure time was 9.0 min. There were 7 (6.3%) moderate complications (5 (4.5%) post-operative bleeds requiring suture and 2 (1.8%) post-operative infections) affecting 7 men. No men experienced significant wound dehiscence. 90.4% of men were fully healed at 4 weeks of follow-up and all were highly satisfied.

Conclusions

Use of topical anaesthesia obviates the need for injectable anesthetic and makes the Unicirc procedure nearly painless. Unicirc is rapid, easy to learn, heals by primary intention with excellent cosmetic results, obviates the need for a return visit for device removal, and is potentially cheaper and safer than other methods. Use of this method will greatly facilitate scale-up of mass circumcision programs.

Trial Registration

ClinicalTrials.gov NCT02091726

A systematic examination of the effect of tissue glues on rhytidectomy complications

BACKGROUND

Fibrin glue has widespread use in multiple fields of surgery. There have been numerous studies on the use of fibrin glue in facelifts, with no consensus regarding differences in outcomes.

OBJECTIVES

This study compared the risk of hematoma, seroma, and the 24-hour drainage volume in all published prospective controlled trials.

METHODS

A MEDLINE search of English-language articles on fibrin glue and rhytidectomy published up to July 2013 yielded 49 citations. After screening, we examined 7 relevant controlled trials. The DerSimonian and Laird random-effects model was used to perform the meta-analysis.

RESULTS

Seven controlled trials measuring the outcomes of fibrin glue in facelifts were used to estimate the pooled relative risk of complications and confidence intervals. Hematoma formation was four times less likely with the use of fibrin glue (relative risk 0.25, P = .002). There was no significant reduction in seroma formation (relative risk 0.56, P = .19). There was not enough data to properly measure 24-hour drainage and ecchymoses.

CONCLUSIONS

This analysis suggests that fibrin glue reduces the rates of hematoma formation, but does not significantly reduce the rates of seroma development.

LEVEL OF EVIDENCE

3 Therapeutic.

Mucoadhesive cellulosic derivative sponges as drug delivery system for vaginal application

Vaginal delivery of active drugs has been largely studied for local and systemic applications. It is well known that vagina is a complex route, due to physiological and non-physiological changes. Therefore, in order to achieve a prolonged local effect, these variations have to be considered. The aim of this study was to formulate and to characterize a solid system, called sponges, obtained by lyophilization of cellulosic derivative (HEC 250M) hydrogels. These sponges have to meet particular criteria to be adapted for vaginal application: they have to adhere to the vaginal cavity and to be rehydrated by the small amount of vaginal fluids. Moreover, they have to be easily manipulated and to be stable. Three freezing temperatures have been tested to prepare sponges (-15°C, -25°C, -35°C). By SEM analyzes, it was observed that the pores into the sponges were smaller and numerous as the freezing temperature decreases. However, this temperature did not have any influence on the rehydration speed that was rather influenced by the HEC concentration. Viscosity and mucoadhesive strength of hydrogels and corresponding sponges were also measured. It appeared that these parameters are mainly dependent on the HEC concentration. These mucoadhesive sponges can be considered as potential drug delivery systems intended for vaginal application.

Comparative evaluation of cyanoacrylate and fibrin glue for muscle recession in strabismus surgery

PURPOSE

To compare the safety and efficacy of fibrin glue and cyanoacrylate glue for refixating the recessed muscle to the sclera in patients undergoing strabismus surgery.

METHODS

In this prospective, randomized, and interventional case series, there were 15 patients in each group. Two different types of glue were used for refixating the muscle to the sclera after its recession: fibrin glue (fibrin group) and cyanoacrylate glue (cyanoacrylate group). Resection was performed as usual with a 6-0 polyglactin suture. The conjunctiva was closed with the same glue that was used for muscle recession.

RESULTS

Average time required per muscle attachment was 1.48±0.694 minutes in the fibrin group and 2.42±0.584 minutes in the cyanoacrylate group. There was no significant difference in pain at all postoperative visits in both groups. Significantly more chemosis was observed in the cyanoacrylate group at postoperative 3 weeks. At all other postoperative visits, there was no significant difference in chemosis in both groups. There was significantly more conjunctival reaction in the cyanoacrylate group at 1 and 3 weeks and 3 months; the difference was highly significant at 3 months (P=.00). Total inflammatory score was significantly high in the cyanoacrylate group at 1 week, 3 weeks, and 3 months.

CONCLUSIONS

Both fibrin and cyanoacrylate glue are equally efficacious for muscle reattachment; however, fibrin glue is more biotolerant compared to cyanoacrylate glue and results in less postoperative inflammation, and is thus recommended for recession in strabismus surgery.

Allergic contact dermatitis to 2-octyl cyanoacrylate

Cyanoacrylates are widely used as topical skin adhesives in emergency departments, clinics, and operating rooms. We report 4 patients who developed allergic contact dermatitis (ACD) following postsurgical closure with 2-octyl cyanoacrylate. These patients were challenged with a novel method of use testing to confirm sensitivity to 2-octyl cyanoacrylate. The popularity of skin adhesives makes this emerging allergen worthy of examination. It is possible that cyanoacrylate allergy currently is underrecognized.

Human fibrin glue sealing versus suture polypropylene fixation in Lichtenstein inguinal herniorrhaphy: a prospective observational study

BACKGROUND

Patients who underwent primary inguinal hernia repair still report a high rate of postoperative pain after operation due to the effect of mesh fixation by suture.An alternative is the use of human fibrin glue. We compared the two techniques.

METHODS

468 patients randomly underwent primary inguinal hernia Lichtenstein repair fixing the mesh by suture or by human fibrin glue (HFG); in both cases the mesh was fixed to the posterior wall of the inguinal canal and to the inguinal ligament.

RESULTS

No significant differences were recorded between the two groups in terms of complications, while the sutureless technique reduces the operative time and the postoperative pain.

CONCLUSIONS

A widespread technique for the treatment of inguinal hernia is the application of a mesh using Lichtenstein procedure. The prosthesis can be fixed by traditional suture or using a new method of sutureless fixation with adhesive materials that shows an excellent local tolerability and lack of adverse effects and contraindications.

Clinical comparison between wall defects surgery using conventional and low-adhesion mesh materials Preliminary results

PURPOSE

The use of prosthetic materials for hernia repair has become a standard procedure. Still the optimal material has not yet been found. Primitive hernia with loss of substance and big incisional hernia repair requires a prosthetic material which not induce, especially in the area of visceral peritoneal contact, chronic inflammation and fibrosis. The aim of this study is to clinically compare two different mesh materials: uncoated monofilament polypropylene and polypropylene- polyurethane double surface mesh.

METHODS

Forty eight primitive hernia and incisional hernia affected patients were included in the study. They were randomly allocated in two groups. In each group a different type of mesh was utilized, respectively uncoated monofilament polypropylene mesh and polypropylene-polyurethane double surface synthetic mesh. Lichtenstein and Rives surgical techniques were utilized. Intra-operative, early and late post-operative complications were clinically evaluated.

RESULTS

Uncoated monofilament polypropylene meshes treated patients showed higher abdominal pain, inflammatory diseases and hernia recurrence incidence than polypropylene-polyurethane double surface meshes. Abdominal wall hypo-mobility, discomfort and atypical sensation were the same in the two groups of treated patients.

CONCLUSIONS

Given the limited number of our patient's set, from our preliminary results is possible to assert that polypropylene-polyurethane double surface meshes have revealed superior bio-functional and bio-compatible efficacy.

Combination of fibrin glue protection with microsurgical technique for duct-to-mucosa pancreatico-jejunostomy reduces the incidence of leakages after pancreaticoduodenectomy

The Achilles' heel of pancreatic surgery is the management of the pancreatic stump. Leakage from pancreatic anastomosis with subsequent fistula, abscess formation, sepsis, or bleeding is one of the most common causes of morbidity and mortality, and it also contributes significantly to prolonged hospitalization and increased hospital expenses. Many surgical methods have been developed aimed at reducing the incidence of post-operative pancreatic fistula. However, the best technique for pancreatico-enteric reconstruction continues to be disputed. Herein, we describe an interim analysis of 35 consecutive pancreatico-duodenectomies, all with the same standardized technique that combines microsurgical technique for duct-to-mucosa pancreatico-jejunostomy with the routine use of fibrin sealant. The rate of leakage of pancreaticojejunostomy was 5,7% (n=2), all of which were grade A fistulas, treated conservatively. The increased precision of magnification instruments and microsurgical technique for duct to mucosa anastomosis, combined with routine sealing of the pancreatic anastomosis are key factors to efficiently manage the pancreatic stump. The good results obtained and especially the minimal rate of fistula suggests that this technical solution is a safe, feasible and reliable approach for pancreatic reconstruction after pancreatico-duodenectomy.

Post-embryo transfer interventions for assisted reproduction technology cycles

BACKGROUND

In women undergoing in vitro fertilisation (IVF) and intracytoplasmic sperm injection (ICSI), embryos transferred into the uterine cavity can be expelled due to many factors including uterine peristalsis and contractions, low site of deposition and negative pressure generated when removing the transfer catheter. Techniques to reduce the risk of embryo loss following embryo transfer (ET) have been described but are not standard in all centres conducting ET.

OBJECTIVES

To evaluate the efficacy of interventions used to prevent post-transfer embryo expulsion in women undergoing IVF and ICSI.

SEARCH METHODS

We searched the Menstrual Disorders and Subfertility Group Specialised Register of controlled trials to June 2014 and PubMed, MEDLINE, EMBASE, CENTRAL, PsycINFO, CINAHL, World Health Organization ICTRP, and trial registers from inception to June 2014, with no language restrictions. Additionally, we handsearched reference lists of relevant articles, and ESHRE and ASRM conference abstracts.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of interventions used to prevent post-transfer embryo expulsion in women undergoing IVF and ICSI. Two review authors independently screened titles and abstracts and reviewed the full-texts of all potentially eligible citations to determine whether they met our inclusion criteria. Disagreements were resolved by consensus.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the risk of bias of included trials using standardised, piloted data extraction forms. Data were extracted to allow intention-to-treat analyses. Disagreements were resolved by consensus. The overall quality of the evidence was rated using GRADE methods.

MAIN RESULTS

We included four RCTs (n = 1392 women) which administered the following interventions: bed rest (two trials), fibrin sealant (one trial), and mechanical closure of the cervix (one trial). Our primary outcome, live birth rate, was not reported in any of the included trials; nor were the data available from the corresponding authors. For the ongoing pregnancy rate, two trials comparing more bed rest with less bed rest showed no evidence of a difference between groups (odds ratio (OR) 0.88; 95% confidence interval (CI) 0.60 to 1.31, 542 women, I(2) = 0%, low quality evidence). Secondary outcomes were sporadically reported with the exception of the clinical pregnancy rate, which was reported in all of the included trials. There was no evidence of a difference in clinical pregnancy rate between more bed rest and less bed rest (OR 0.88; 95% CI 0.60 to 1.31, 542 women, I(2) = 0%, low quality evidence) or between fibrin sealant and usual care (OR 0.98; 95% CI 0.54 to 1.78, 211 women, very low quality evidence). However, mechanical closure of the cervix was associated with a higher clinical pregnancy rate than usual care (OR 1.92; 95% CI 1.40 to 2.63, very low quality evidence). The quality of the evidence was rated as low or very low for all outcomes. The main limitations were failure to report live births, imprecision and risk of bias. Overall, the risk of bias of the included trials was high. The use of a proper method of randomisation and allocation concealment was fairly well reported, while only one trial clearly reported blinding. There was no evidence that any of the interventions had an effect on adverse event rates but data were too few to reach any conclusions.

AUTHORS' CONCLUSIONS

There is insufficient evidence to support any specific length of time for women to remain recumbent, if at all, following embryo transfer, nor is there sufficient evidence to recommend the use of fibrin sealants added to the embryo transfer fluid. There is very limited evidence to support the use of mechanical pressure to close the cervical canal following embryo transfer. Further well-designed and powered studies are required to determine the true effectiveness and safety of these interventions.

Treatment of fistula in ano with fibrin glue: preliminary results from a prospective study

AIM

This prospective study was done to evaluate the efficacy of commercial fibrin glue application in the healing of patients with fistulas-in-ano from a short follow up period (one year).

METHODS

This randomized clinical trial of 26 patients was performed during the period from January 2012 to July 2012. Nineteen men and seven women were treated for a fistula-in-ano with a commercial fibrin glue injection. In the operating room, the patients underwent an anorectal examination under spinal anesthesia. The external and internal fistula tract openings were then identified and the fistula tract was accurately curetted. Fibrin glue was introduced by a loaded double-channel syringe into the external fistula opening until the fibrin glue tip could be seen emerging from the internal opening.

RESULTS

The initial success rate was 76.9% (20/26). Recurrence rate was 23% (6/26). Four patients underwent a re-application of fibrin glue and the fistulas of these patients closed. Total recurrence rate was 7.6% (2/26). The overall success rate was 69.2% (18/26).

CONCLUSION

Fibrin glue application was thus found to be an easy, safe, successful alternative treatment in the management of fistulas-in-ano. Specifically, this therapeutic option demonstrated his efficacy for simple non-ramificated transsphincteric and intersphincteric fistulas. Multicentric randomized clinical trials with more representative sample seem to be necessary to investigate the best patients to treat by fibrin glue injection and the optimal application technique to improve these results.

In vivo toxicity and biodistribution of intraperitoneal and intravenous poly-L-lysine and poly-L-lysine/poly-L-glutamate in rats

The combination of two differently charged polypeptides, poly-L-lysine (PL) and poly-L-glutamate (PG), has shown excellent postsurgical antiadhesive properties. However, the high molecular, positively charged PL is toxic in high doses, proposed as lysis of red blood cells. This study aims to elucidate the in vivo toxicity and biodistribution of PL and complex bound PLPG comparing intravenous and intraperitoneal administration. Fifty-six Sprague-Dawley rats were used in a model with repeated blood samples within 30 min examining blood gases and blood smears. Similarly, FITC labelled PL were used to track bio distribution and clearance of PL, given as single dose and complex bound to PG after intravenous and intraperitoneal administration. Tissue for histology and immunohistochemistry was collected. Blood gases and blood smears as well as histology points to a toxic effect of high dose PL given intravenously but not after intraperitoneal administration. The toxic effect is exerted through endothelial disruption and subsequent bleeding in the lungs, provoking sanguineous lung edema. FITC-labelled PL experiments reveal a rapid clearance with differences between routes and complex binding. This study advocates a new theory of the toxic effects in vivo of high molecular PL. PLPG complex is safe to use as antiadhesive prevention based on this toxicity study given that PL is always intraperitoneally administered in combination with PG and that the dose is adequate.

[Intracameral fibrin glue in spontaneous corneal perforation]

CASE REPORT

A 70-year-old male was referred to our department due to a herpetic corneal perforation in the left eye. The perforation was healed with intracameral fibrin tissue sealant (Tissucol(®)), an amniotic membrane, and a large diameter soft contact lens. Postoperatively there were complete dissolution of the fibrin sealant and closure of the perforation without endothelial damage.

DISCUSSION

Intracameral fibrin glue may be effective in the closure of corneal perforations.