AN EXPERIMENTAL EVALUATION OF THE EFFECT OF A PLASTIC ADHESIVE, METHYL 2-CYANOACRYLATE, ON NEURAL TISSUE

Contact Dermatitis in the Surgical Patient: A Focus on Wound Closure Materials

ABSTRACT

Irritant and allergic contact dermatitis from wound closure materials can occur in patients after surgical procedures. The resulting inflammation from contact dermatitis can compromise wound healing, mimic surgical site infections, and result in wound dehiscence. Components of wound closure material, such as antibiotic coatings, dyes, sterilizing compounds, or the material itself, have been implicated as contact allergens. This article provides the latest overview of the components of 3 major forms of wound closure materials-sutures, staples, and tissue adhesives-associated with contact dermatitis, discusses their cross-reactivity, and provides diagnostic and treatment guidelines.

Complications associated with Dermabond® during head and neck surgery: MAUDE and literature review

INTRODUCTION

Dermabond® is a liquid surgical sealant containing 2-octyl-cyanoacrylate that has been widely used during head and neck surgeries. This study aims to provide a summary of adverse events related to Dermabond® in head and neck procedures as reported in the MAUDE database, and to report a complete overview of all documented adverse events related to Dermabond® use in current literature.

METHODS

The US Food and Drug Administration's Manufacturer and User Facility Device Experience (MAUDE) database was queried for reports of adverse events related to Dermabond® use from January 1, 2010, to February 1, 2020. Data were extracted from reports pertaining to head and neck procedures. In addition, literature review was performed from January 1970 to January 2021. Various adverse events related to Dermabond® were included in the study.

RESULTS

We identified 32 adverse events, from which 29 (90.6%) were patient-related events and 3 (9.4%) were operator-related events. Of the patient-related events, contact dermatitis (CD) (20 [69.0%]) was the most common, followed by wound dehiscence (4 [13.8%]). All of the operator-related events were from inadvertent cut injury (3 [100%]). Following the literature review, adverse events of Dermabond® were categorized into CD, wound dehiscence, infection, and cut injury.

CONCLUSION

Dermabond® demonstrated utility in various surgical procedures including head and neck surgeries but are associated with risks. This study identified adverse events associated with Dermabond®. Further studies are needed to establish the causation of contact dermatitis in certain populations.

Photocrosslinkable Gelatin/Tropoelastin Hydrogel Adhesives for Peripheral Nerve Repair

Suturing peripheral nerve transections is the predominant therapeutic strategy for nerve repair. However, the use of sutures leads to scar tissue formation, hinders nerve regeneration, and prevents functional recovery. Fibrin-based adhesives have been widely used for nerve reconstruction, but their limited adhesive and mechanical strength and inability to promote nerve regeneration hamper their utility as a stand-alone intervention. To overcome these challenges, we engineered composite hydrogels that are neurosupportive and possess strong tissue adhesion. These composites were synthesized by photocrosslinking two naturally derived polymers, gelatin-methacryloyl (GelMA) and methacryloyl-substituted tropoelastin (MeTro). The engineered materials exhibited tunable mechanical properties by varying the GelMA/MeTro ratio. In addition, GelMA/MeTro hydrogels exhibited 15-fold higher adhesive strength to nerve tissue ex vivo compared to fibrin control. Furthermore, the composites were shown to support Schwann cell (SC) viability and proliferation, as well as neurite extension and glial cell participation in vitro, which are essential cellular components for nerve regeneration. Finally, subcutaneously implanted GelMA/MeTro hydrogels exhibited slower degradation in vivo compared with pure GelMA, indicating its potential to support the growth of slowly regenerating nerves. Thus, GelMA/MeTro composites may be used as clinically relevant biomaterials to regenerate nerves and reduce the need for microsurgical suturing during nerve reconstruction.

Biocompatible alkyl cyanoacrylates and their derivatives as bio-adhesives

Cyanoacrylate adhesives and their homologues have elicited interest over the past few decades owing to their applications in the biomedical sector, extending from tissue adhesives to scaffolds to implants to dental material and adhesives, because of their inherent biocompatibility and ability to polymerize solely with moisture, thanks to which they adhere to any substrate containing moisture such as the skin.

Cyanoacrylate Adhesive as an Alternative Tool for Membrane Fixation in Guided Tissue Regeneration

AIM

To report a well succeeded use of cyanoacrylate adhesive for fixating a resorbable membrane during a guided tissue regeneration procedure (GTR).

BACKGROUND

The immobilization of membranes in GTR is essential for establishing proper environment for cell differentiation and tissue regeneration. However, some membranes are very difficult to be kept in position by sutures and its fixation by mini screws or pins may be time consuming and expensive.

CASE DESCRIPTION

A 47-year-old woman presenting a vertical bone defect at the palatal aspect of the left central incisor was treated by GTR using particulate autogenous bone graft associated to a collagen membrane. The membrane was glued to the bone surrounding the defect and to the tooth surface with cyanoacrylate adhesive. The postoperative period was uneventful and 4 years later, excellent results in terms of radiographic filling of the defect and reduction of the probing depth were seen. For illustrative purposes, histological findings obtained during a previous experiment in calvaria of guinea pigs is shown, characterizing a foreign body granuloma and proving that the cyanoacrylate adhesive is a safe tool in GTR.

CONCLUSION

The use of a membrane glued with cyanoacrylate to immobilize membranes in GTR is viable and safe from both technical and biological standpoints and may be advantageous for clinical and research purposes.

CLINICAL SIGNIFICANCE

The alternative method for membrane fixation shown in this case report can contribute to simplify the technique in GTR procedures.

Nerve repair: toward a sutureless approach

Peripheral nerve repair for complete section injuries employ reconstructive techniques that invariably require sutures in their application. Sutures are unable to seal the nerve, thus incapable of preventing leakage of important intraneural fluids from the regenerating nerve. Furthermore, sutures are technically demanding to apply for direct repairs and often induce detrimental scarring that impedes healing and functional recovery. To overcome these limitations, biocompatible and biodegradable glues have been used to seal and repair peripheral nerves. Although creating a sufficient seal, they can lack flexibility and present infection risks or cytotoxicity. Other adhesive biomaterials have recently emerged into practice that are usually based on proteins such as albumin and collagen or polysaccharides like chitosan. These adhesives form their union to nerve tissue by either photothermal (tissue welding) or photochemical (tissue bonding) activation with laser light. These biomaterial adhesives offer significant advantages over sutures, such as their capacity to unite and seal the epineurium, ease of application, reduced invasiveness and add the potential for drug delivery in situ to facilitate regeneration. This paper reviews a number of different peripheral nerve repair (or reconstructive) techniques currently used clinically and in experimental procedures for nerve injuries with or without tissue deficit.

Use of cyanoacrylate in the coaptation of edges of surgical wounds

Cyanoacrylate has been used in several fields of different surgical specialties as an adhesive for closure of gingival flaps and in mucous and cutaneous lacerations. One of its advantages is that it has an excellent immunological response. In view of aesthetic needs, cyanoacrylate has been applied with satisfactory results, when compared with sutures. It presents better coaptation of edges of cutaneous and mucosal lesions, smaller residual scars, and biocompatibility. However, it is limited to areas of little tissue tension. This work attempts to provide a literature review with the aim of revealing the advantages of using tissue adhesives, especially cyanoacrylates, in wound coaptation in comparison with conventional methods.

Effectiveness of fibrin adhesive in facial nerve anastomosis in dogs compared with standard microsuturing technique

PURPOSE

Epineural suturing is the most common technique used for peripheral nerve anastomosis. In addition to the foreign body reaction to the suture material, the surgical duration and difficulty of suturing in confined anatomic locations are major problems. We evaluated the effectiveness of fibrin glue as an acceptable alternative for nerve anastomosis in dogs.

METHODS

Eight adult female dogs weighing 18 to 24 kg were used in the present study. The facial nerve was transected bilaterally. On the right side, the facial nerve was subjected to epineural suturing; and on the left side, the nerve was anastomosed using fibrin adhesive. After 16 weeks, the nerve conduction velocity and proportion of the nerve fibers that crossed the anastomosis site were evaluated and compared for the epineural suture (right side) and fibrin glue (left side). The data were analyzed using the paired t test and univariate analysis of variance.

RESULTS

The mean postoperative nerve conduction velocity was 29.87 ± 7.65 m/s and 26.75 ± 3.97 m/s on the right and left side, respectively. No statistically significant difference was found in the postoperative nerve conduction velocity between the 2 techniques (P = .444). The proportion of nerve fibers that crossed the anastomotic site was 71.25% ± 7.59% and 72.25% ± 8.31% on the right and left side, respectively. The histologic evaluation showed no statistically significant difference in the proportion of the nerve fibers that crossed the anastomotic site between the 2 techniques (P = .598).

CONCLUSIONS

The results suggest that the efficacies of epineural suturing and fibrin gluing in peripheral nerve anastomosis are similar.

Skull base cerebrospinal fluid leakage control with a fibrin-based composite tissue adhesive

Cerebrospinal fluid (CSF) leaks can be responsible for significant patient morbidity and mortality. While the majority of leaks induced after head trauma will seal without intervention, spontaneous or surgically-induced leaks often require operative repair. Many modifications on standard surgical technique are available for repair of CSF fistulae, but none assures adequate closure. We have studied the efficacy of a novel fibrin-based composite tissue adhesive (CTA) for closure of experimentally-induced CSF leaks in rats. Fistulae were created in two groups of animals. Two weeks after creation of the leaks, the animals were sacrificed and analyzed for persistence of leak. A 58% leakage rate was noted in the control group (n = 12), and no leaks were noted in the experimental group closed after application of CTA to the surgical defect followed by skin closure (n = 11). Comparing the control group to the experimental group, results were statistically significant (p = 0.015). These data suggest that CTA may be effective as an adjunct for the closure of CSF fistulae.

Adesivos à base de cianoacrilato para síntese de tecido mole

FUNDAMENTOS - Adesivos teciduais têm sido muito usados para síntese de ferida, em função de ser um método indolor, rápido e de fácil execução. OBJETIVOS -Analisar e comparar compatibilidade dos adesivos, etil- cianoacrilato (Super Bonder) e butilcianoacrilato (Histoacryl), e a reparação de incisões em dorso de ratos entre o fio de sutura e os respectivos adesivos. MÉTODOS - Foram usados 15 ratos. Realizaram-se duas lojas cirúrgicas no dorso. Em cada uma, foi implantado um tubo de polietileno (10mm x 1mm), os quais foram preenchidos com os adesivos Super Bonder (lado direito) e Histoacryl (lado esquerdo). As incisões, do lado esquerdo, foram coaptadas com Super Bonder, e as do lado direito, com Histoacryl. Uma incisão mediana, entre as duas incisões,foi realizada e suturada com fio de seda. Os animais foram mortos, depois de 7(sete), 35(trinta) e 120 (cento e vinte dia) dias. RESULTADOS: Os adesivos usados, no presente estudo, não promoveram reação inflamatória, quando usados para síntese das incisões. Porém, estes adesivos, quando implantados no subcutâneo, promoveram reação inflamatória até 120 (cento e vinte dia) dias, no entanto, a reação é mais intensa com Histoacryl. CONCLUSÕES: Super Bonder e Histoacryl permitem o processo cicatricial dos tecidos incisados; facilitam a sutura das incisões. Desta forma, estes podem ser utilizados para sínteses de feridas, lacerações ou incisões cutâneas.

Anastomose do nervo facial de coelhos com cola de fibrina: estudo da velocidade de condução nervosa

OBJETIVO: Este estudo tem o objetivo de avaliar através da velocidade de condução nervosa com eletrodos de superfície a utilização da cola de fibrina na anastomose nervosa. MÉTODOS: Neste experimento, foram avaliadas as diferenças entre as velocidades de condução nervosa pré e pós-operatória do nervo facial esquerdo de 12 coelhos. Foi verificada a existência de correlação entre a velocidade de condução nervosa e o número de axônios regenerados no pós-operatório. Os nervos transeccionados foram unidos com cola de fibrina. O potencial de ação motora foi obtido com o uso de eletrodos de superfície. O eletrodo de estimulação foi colocado imediatamente à frente do pavilhão auditivo (tronco do nervo facial) e o eletrodo de gravação foi colocado no músculo quadrado do lábio inferior. RESULTADOS: A média normal da velocidade de condução nervosa foi de 36,53 m/seg. Ao final do período, a velocidade de condução nervosa atingiu um valor de aproximadamente 81% do valor normal. Não foi observada correlação significativa entre a velocidade de condução nervosa pós-operatória e o número de axônios regenerados (p=0,146). CONCLUSÃO: A anastomose com cola de fibrina pode ser utilizada para anastomose nervosa no modelo animal e nervo estudados.

Rabbit facial nerve anastomosis with fibrin glue: nerve conduction velocity evaluation

AIM

The aim of this study was to evaluate the use of fibrin glue on nerve anastomosis, and study conduction velocity obtained by surface electrodes.

METHODS

In this experimental model we evaluated nerve conduction velocity differences in the preoperative and postoperative periods, for the left facial nerve of 12 rabbits. Then, we evaluated whether there were correlations between conduction velocity and the number of postoperative regenerated axons. The sectioned nerves were anastomosed with fibrin glue. The muscle action potentials were obtained from surface electrodes. The stimulation electrode was placed immediately before the ear pinna (facial nerve trunk) and the recording surface electrode was placed on the quadratus labii inferioris muscle.

RESULTS

The facial nerve normal conduction velocity mean value was of 36.53 m/sec. On the postoperative period, the mean conduction velocity was approximately 81% of the normal mean value. A significant correlation was not observed between the postoperative conduction velocity and the number of regenerated axons (p=0.146).

CONCLUSION

The fibrin glue can be used on nerve anastomosis in this animal model and nerve.

Cyanoacrylates for Skin Closure

Cyanoacrylates (CAs) were not widely adopted for medical use until recently because of lingering concerns regarding the initial tissue toxicities of the short-chain CAs. The medium-chain CAs, primarily butyl-cyanoacrylate, have been widely used in Europe and Canada for several decades and have gone a long way in dispelling any lingering concerns about tissue toxicity. The newer, longer chain CA, octyl-2-cyanoacrylate (2-OCA), now has been approved for multiple uses in the United States and has achieved widespread acceptance by the medical and lay communities. The current authors believe that this is probably only the beginning of the use of 2-OCA and other CAs in cutaneous medicine. This article discusses the use of CAs in their original cutaneous use as glues for the repair of lacerations and incisions and in their more recent use as dressings for the treatment of abrasions and wounds.

Facial nerve repair with epineural suture and anastomosis using fibrin adhesive: An experimental study in the rabbit

PURPOSE

An experimental model in rabbits was used to compare epineural suturing and fibrin adhesive anastomosis for facial nerve repair.

MATERIALS AND METHODS

Thirty-four facial nerves from 17 rabbits were isolated, transected, and anastomosed, with an evaluation of their electrophysiologic and histologic parameters. The rabbits were divided into 2 groups of 5 and 12 animals, respectively: a 10-mm defect was made in the right facial nerve in the first group, with transection and epineural suturing of the left nerve, followed by death after 120 days. This was the control-versus-epineural suture group. In the second group, the right facial nerve was transected and subjected to epineural suturing, while the left nerve was transected and anastomosed using fibrin adhesive. The rabbits were killed 15, 30, 60, and 120 days after the microsurgical procedure. This was the epineural suture-versus-fibrin adhesive group.

RESULTS

From day 30, the number of regenerated axons increased with time in the epineural suture and fibrin adhesive anastomotic specimens. Epineural suture showed more regenerated axons and a faster linear rate of regeneration than anastomosis with fibrin adhesive. The reduction in conduction velocity decreased significantly with time with the same linear pattern for both suture techniques.

CONCLUSIONS

Epineural suturing offered superior performance versus anastomosis with fibrin adhesive in terms of axon count but not in decrease in conduction velocity.

A liquid adhesive bandage for the treatment of minor cuts and abrasions

BACKGROUND

Octyl-2-cyanoacrylate is U.S. Food and Drug Administration (FDA) approved for the closure of incisions and lacerations. In animal studies, a more flexible formulation of octyl-2-cyanoacrylate suitable for cuts and abrasions produced faster healing of partial thickness wounds than traditional bandages.

OBJECTIVE

To evaluate the effectiveness of a more flexible octyl-2-cyanoacrylate liquid adhesive bandage for the treatment of minor cuts and abrasions.

METHODS

One hundred sixty-two volunteers with recent minor cuts or abrasions were recruited and randomized to treatment with either liquid adhesive bandage (LAB) or a control device (Band-Aid brand adhesive bandage, sheer, 2.5 cm). The primary efficacy criterion was complete healing at day 12. Secondary efficacy criteria were the ability of patients to properly apply LAB, and the ability of LAB to stop bleeding, to reduce pain, and to remain on the wound.

RESULTS

At day 12 there was no statistical difference between the number of completely healed wounds in the LAB and the bandage-treated patients (P =.493). The ability of patients, as rated by investigators, to effectively apply the LAB device and the bandage was not significantly different (P =.165). Only the LAB provided significant hemostasis (P =.0001) and pain relief (P =.002).

CONCLUSION

In this randomized, controlled trial, the LAB was as effective as the control at promoting healing as measured by complete healing at day 12. The LAB was easy to use and gave rapid control of bleeding and pain, forming a film that stayed on wounds well.

Use of isobutyl cyanoacrylate tissue adhesive to stabilize external eyelid weights in temporary treatment of facial palsies

PURPOSE

To describe a technique for stabilizing external eyelid load weights with isobutyl cyanoacrylate tissue adhesive for the temporary treatment of facial palsies.

METHODS

This was a nonrandomized, prospective study of six consecutive patients with unilateral facial paralysis treated with external eyelid load weights stabilized with isobutyl cyanoacrylate tissue adhesive instead of adhesive tape. Follow-up assessment included corneal exposure, patient comfort, amount of artificial tear usage, and complications associated with the weights.

RESULTS

Of the six patients studied, five had decreased corneal exposure, decreased artificial tear usage, and increased patient comfort with use of the weights. One patient had no improvement of symptoms. Weights were retained for a mean of 10.7 days. Two patients had difficulty with the weights; one was secondary to dermatochalasis and blepharoptosis obscuring his vision, and the other patient's weight fell off after 1 day. No weights were lost.

CONCLUSIONS

The use of isobutyl cyanoacrylate tissue adhesive is a simple, quick, and inexpensive method for placement of external eyelid weights for temporary treatment of ocular exposure associated with facial paralysis and for determining the correct weight for implantation. Furthermore, isobutyl cyanoacrylate tissue adhesive used to stabilize external eyelid weights is better tolerated and lasts longer than the previously described fixation method with adhesive tape.

Delayed parent artery narrowing occurring months after aneurysm surgery: a complication after aneurysm surgery--technical case report

The authors report two patients with a rare complication of parent artery narrowing that occurred 3 and 6 months after aneurysm surgery. In both cases, the stenosed arteries had been wrapped around their entire circumferences with neurosurgical sponge (cotton linter) and coated with plastic adhesive (cyanoacrylate compounds) and the aneurysmal neck had been clipped. This reinforcement procedure was considered to have caused the unusual delayed arterial narrowing. The importance of avoiding circumferential parent artery wrapping with plastic-adhesive coating is emphasized.

Coating of intracranial aneurysms: a long-term follow-up study of 34 cases

We performed a retrospective follow-up study of 33 patients, with 34 ruptured aneurysms, treated by coating using bio-adhesive polymers. The rebleeding rate after a mean follow-up of 10 years was 18% (6 patients), with 4 cases of early haemorrhage and 2 late rebleedings (late rebleeding rate of 0.7% per year). All rebleedings proved fatal. Coating of the aneurysmal wall provides some protection in patients with "unclippable" aneurysms, but is obviously inferior to clipping, and should be used only in very selected cases.

Superior nerve anastomosis using a low-output CO2 laser on fibrin membrane

BACKGROUND AND OBJECTIVE

To date, no procedure of laser-aided nerve anastomosis has yet proved to be consistently superior to suture nerve repair. This study examines a new method for nerve repair using a low output CO2 laser and fibrin membrane to ascertain the efficacy of this method for nerve regeneration in comparison with the suture method.

STUDY DESIGN/MATERIALS AND METHODS

Both sciatic nerves of 42 Wister rats were used. The left sciatic nerves were cut and reconnected using 70 mW of irradiation on fibrin membrane bridging the nerve stumps, whereas the right sciatic nerves were repaired with two stitches of epineuro-fascicular sutures.

RESULTS

No deleterious effect of the irradiation on nerve regeneration was demonstrated at any time after surgery. The number of myelinated axons larger than 5 microns in diameter and the mean diameter of mylinated axons 8 weeks after surgery were significantly larger in the laser group than those in the suture group (P < 0.05).

CONCLUSION

The results suggest this new method may be useful and effective for clinical nerve repair.

Viscous isoamyl 2-cyanoacrylate as an osseous adhesive in the repair of osteochondral osteotomies in rabbits

An in vivo study of viscous isoamyl 2-cyanoacrylate used in limited amounts as an osseous adhesive was performed to evaluate the ability of the monomer to maintain the reduction of an unstable intra-articular osteochondral osteotomy as well as to allow for healing around the sites of adhesive placement. A histologic evaluation of any inflammatory reaction involving adjacent bone, cartilage, or synovium was also performed. Osteochondral fragments were created in 48 rabbit knees. In 24 knees, reduction of the fragment was secured with one small drop of adhesive at either end of the osteotomy surface. In 24 control knees, no adhesive was used. Ninety-six percent of the osteotomies in the adhesive treated group healed versus 50% of the control group. This difference is statistically significant (p less than 0.05). Osseous and cartilaginous healing was noted to proceed in an apparently unimpaired fashion around the sites of adhesive placement, and no inflammatory reaction involving adjacent viable tissue was evident.

The histotoxicity of cyanoacrylates. A selective review

Cyanoacrylates, a group of rapidly polymerizing adhesives, have found widespread uses in oral and general surgery as well as surgical subspecialties, for example as hemostatic and anastomotic agents. They have been utilized most recently as materials for embolotherapy of complex cerebral and extra-cerebral vascular anomalies. The histopathology that results from their deposition in human tissues is thus an important consideration, and the subject of this review. Particular attention is given to the fate of cyanoacrylates in cerebral lesions after iatrogenic embolization procedures. The apparent toxicity of these plastics on blood vessel walls is discussed in relation to experimental observations. It is imperative that clinicians who use this group of substances evaluate their potential functions in the light of the pathologic findings.

Neuropathological changes related to the transorbital application of ethyl 2-cyanoacrylate adhesive to the basal cerebral arteries of cats

The long-term toxic effects of ethyl 2-cyanoacrylate adhesive were evaluated histologically in 25 cats. Fresh medical- or commercial-grade adhesive was introduced transorbitally into the subarachnoid space in the vicinity of the right middle cerebral artery. Three sham-operated animals served as controls. The animals were sacrificed at intervals ranging from 2 days to 6 months. For both medical- and commercial-grade adhesive, neuropathological examination disclosed acute and chronic granulomatous inflammation of the meninges and evidence of severe vascular damage, including vessel wall necrosis, inflammation, thrombosis, and occasionally hemorrhage. Most animals showed cerebral infarcts of variable size in the territories of distribution of the basal arteries which were in contact with adhesive. The results of this study show that ethyl 2-cyanoacrylate is capable of producing severe arterial and parenchymal damage. The risk of its deleterious effects should be weighed against its potential benefits. Clinical experience would suggest that ethyl 2-cyanoacrylate can be used in difficult situations as long as care is taken to protect the brain and local blood vessels.

Isobutyl 2-cyanoacrylate as an osseous adhesive in the repair of osteochondral fractures

An in vivo evaluation of isobutyl 2-cyanoacrylate as an osseous adhesive was done in an effort to answer two questions: Used in limited amounts, can this monomer maintain the reduction of an unstable intra-articular osteochondral fracture while allowing for fracture healing around the sites of adhesive placement? Used in limited amounts, in this monomer toxic to adjacent viable bone? Osteochondral fractures were created in 32 dog knees. In 16 knees, the fracture reduction was secured with three small drops of adhesive placed around the periphery of the fracture surface. In 16 control knees no adhesive was used. Eighty-one percent of the fractures in the adhesive-treated group united compared to 56% of the control group. Although the difference in number of fractures that healed in the two groups is not definitely statistically significant and no conclusion was drawn as to effectiveness of the adhesive, osseous healing was noted to proceed around the sites of adhesive placement and the monomer appeared nontoxic to adjacent bone.

Healing of periodontal flaps following use of MBR 4197 (flucrylate) in rhesus monkeys. A clinical and histological evaluation

Experimental periodontal surgery was performed on six adult Rhesus monkeys, using the modified Widman flap technique. Each monkey provided four or six segments for flap surgery, and three different experimental time intervals were used. Flaps were immobilized after surgery by conventional sutures or by application of MBR 4197 cyanoacrylate spray. Each animal provided its own contralateral comparison, and the mode of flap immobilization was reversed in the corresponding segments in the other animal of each experimental group. One monkey died approximately 12 hours after surgery, and the other animals were sacrificed at 14, 35 and 180 days. Histological sections were prepared from all operated areas, and examined for the pattern of healing. A special staining technique was used to determine the presence of MBR 4197 within the tissues.

A physiological sealant for cerebrospinal fluid leaks

A combination of concentrated platelets, thrombin, and fibronogen was used to adhere a pericranial graft to surgically produced cerebrospinal fuild (CSF) fistulas in dogs. This sealant successfully stopped leakage of CSF in all fistulas produced in both acute and chronic preparations. All control animals leaked CSF acutely. In chronic control animals the CSF leaks sealed spontaneously but the grafts were not well incorporated. Histoligical examination of the grafts and underlying brain showed not injury to the brain of meningeal vessel from exposure to the platelet glue. Good fibrous union of the grafts to the dura was confirmed.

[Early and late results after coating intracranial aneurysms with biobond (author's transl)]

Fifteen patients with intracranial aneurysms have been treated by coating the aneurysms with Biobond. Three patients died in the postoperative period. Only one patient had recurrent haemorrhage one year after operation. In this case the sac had not been wrapped completely at operation. Histological examination of this aneurysm revealed macrophage reaction and signs of slow disappearance of the plastic. Ten patients, who were followed up for a period of 3 to 8 years after operation, had no recurrent haemorrhage and were in good clinical condition, 8 of them doing full-time work. No complications caused by the material have been encountered. In 5 patients carotid angiography was performed after operation. In 2 cases the size of the aneurysm was diminished and in 3 cases was unchanged. There were no signs of thrombosis or narrowing of the adjacent arteries. We believe that Biobond is suitable for coating intracranial aneurysms that cannot be treated by clipping or ligature. As Biobond in vivo seems partially to disappear after long periods, it should be applied in thick layers.

Use of tissue adhesive in the surgical treatment of cerebrospinal fluid leaks. Experience with isobutyl 2-cyanoacrylate in 12 cases

✓ This report describes 12 cases of cerebrospinal fluid leak repaired with isobutyl 2-cyanoacrylate. We have found this tissue adhesive to be a valuable technical adjunct in the management of this problem and have not seen any general or local toxicity to the material.