Search PubMed⌕ Search

Biomedical subjects

K H Siedentop

Publications and source records attributed to K H Siedentop.

At least 19 recordsLinked to original sources

Technical manual for manufacturing autologous fibrin tissue adhesive.

PURPOSE: The aim of this article is to provide a concise and simple technical manual for manufacturing autologous fibrin tissue adhesive derived from the precipitation of fibrinogen using a combination of ethanol and freezing for surgery. METHODS: All materials and equipment needed to manufacture ethanol-based autologous fibrin tissue adhesive are listed. In addition, step-by-step instructions are provided to allow for easy and rapid fibrin adhesive production. RESULTS: Ethanol-based autologous fibrin tissue adhesive can be manufactured in under 60 minutes. Furthermore, at our institution the startup cost for manufacturing ethanol-based autologous fibrin tissue adhesive was under $2,500.00. CONCLUSION: Ethanol-based autologous fibrin tissue adhesive is a safe, reliable, and easily manufactured autologous fibrin tissue adhesive that can be made by a trained technician in any blood bank, pharmacy, or surgical laboratory.

Ethanol↗

Fibrin sealant for treatment of cerebrospinal fluid leaks.

OBJECTIVE: Persistent cerebrospinal fluid leaks in the human population are rarely found in otherwise healthy individuals, but occur in patients with comorbid illnesses. These leaks are frequently resistant to dural suturing or closure of the defect site with connective tissue, cartilage, or plastic materials. In this study, fibrin sealant (ViGuard Fibrin Sealant was used to adhere muscle grafts to surgically created dural defects to close cerebrospinal fluid leaks in chinchillas. Histologic evaluation of the defect sites were conducted to assess healing and tissue response in the test and control groups. METHOD: In 20 chinchillas, after a skin incision, a 6 mm X 6 mm window was created in the right superior bulla exposing the underlying bony tegmen. Using a microcutting burr, a 3 mm X 3 mm area of tegmen was drilled out and the exposed dura was resected to create a large cerebrospinal fluid (CSF) leak. In the control group (n = 10), a small muscle graft from the surrounding tissue was placed into the defect site. In the test group (n = 10), the muscle graft was glued into the defect with ViGuard Fibrin Sealant. Bulla and skin were then closed. All animals were killed at 3 weeks into the experiment, and tissue was harvested for histologic examination. SETTING: The Department of Otolaryngology, Head and Neck Surgery Research Laboratory. University of Illinois, Chicago. RESULTS: Three weeks after surgery in the test group the tegmen defects were found to be closed by bone or connective tissue or both. Meninges had regrown, and the underlying brain appeared histologically normal. There was no evidence of CSF leak, toxicity, infection or other deleterious tissue reactions. In the control group, again the meningeal and bony tegmen defects were seen to be closed by connective tissue or bone or both. Brain tissues appeared histologically normal. There was no evidence of CSF leak, toxicity, or other deleterious tissue reactions. One animal of the test group died of unknown causes. On autopsy, no signs of meningitis or encephalitis could be detected and the cause of death was unapparent. CONCLUSION: Fibrin Sealant, made from pooled donor blood and treated with viral elimination procedures, was found in combination with muscle grafts to securely close induced CSF leaks in the chinchilla model. Inflammation, infection, or toxic reactions were not observed. We believe that ViGuard Fibrin Sealant has stronger bonding power compared with available autologous fibrin tissue adhesives.

Animals↗

Comparison of the bonding power of various autologous fibrin tissue adhesives.

OBJECTIVE: Three known autologous fibrin tissue adhesives were evaluated for bonding power on Silastic and animal and human tissues. These adhesives were also injected into living tissue to determine if any of these fibrin glues cause inflammatory or deleterious reactions when kept in living tissue for a sustained period. METHODS: In Part I of our study, blood was drawn from 59 healthy volunteers, and autologous fibrin tissue adhesives were manufactured using the cryoprecipitation (AFTA-C), ammonium sulfate (AFTA-A), and ethanol/freezing (AFTA-E) methods. Blocks were then prepared using Silastic, porcine dermis, and human dura mater and bonded together for 10 or 30 minutes using the three adhesives. The blocks were then separated while bonding power was measured. In Part II of our study, 0.01 mL AFTA-C, AFTA-A, or AFTA-E was injected subcutaneously into the auricles of 60 rats. The rats were then killed 3, 7, 14, or 21 days later, and the auricles were examined histologically for signs of toxicity. RESULTS: The bonding powers of AFTA-E and AFTA-C were found to be statistically similar, and both were statistically stronger than AFTA-A. The injection of AFTA-A, AFTA-E, and AFTA-C into rat auricles did not cause any adverse effects. CONCLUSIONS: All three methods for manufacturing AFTA are effective in producing a reliable, stable fibrin glue. However, AFTA-E and AFTA-C demonstrate stronger bonding power than AFTA-A. In addition, all three forms of AFTA produce no undesirable tissue changes when injected into rat auricles.

Animals↗

Evaluation of pooled fibrin sealant for ear surgery.

HYPOTHESIS: This study investigated the bonding strength and tissue toxicity of a commercially prepared dual-virally-inactivated pooled-blood fibrin tissue adhesive (ViGuard-FS; Melville Biologics, Inc., NY, U.S.A.) and compared it with an autologous fibrin tissue adhesive made by the precipitation of fibrinogen using ethanol and freezing (AFTA-E). METHODS: The bonding strength of FS was optimized by varying the concentrations of fibrinogen and human or bovine thrombin using three different surface media: inorganic (silastic), animal skin, and human dura mater. Furthermore, tissue reactions and duration of fibrin clots were studied by injecting FS into the auricles of rats. RESULTS: This study showed that optimized FS with human thrombin was superior in bonding strength to AFTA-E on all three surface media, and that FS does not produce any toxic tissue responses when injected into rat auricles. Minimal traces of the adhesive clot could be observed in a few auricles at 35 days after application. CONCLUSIONS: Because it is made from pooled-donor blood that has been treated with virus elimination procedures, FS is superior to autologous fibrin tissue adhesive in which fibrinogen is precipitated by the ethanol/freezing method. FS has not shown any undesirable tissue reactions when injected into live rat auricles. We believe that these results provide a rationale for further clinical development of ViGuard-FS as a tissue adhesive for otologic surgery.

Animals↗

An autologous fibrin tissue adhesive with greater bonding power.

OBJECTIVE: To describe and evaluate an autologous fibrin tissue adhesive (AFTA) that uses a combination of ethanol and freezing to precipitate fibrinogen (AFTA-E). DESIGN: The bonding power of AFTA-E was compared with that of a conventional AFTA based on ammonium sulfate precipitation of fibrinogen (AFTA-A). In this study, Silastic, porcine dermis, and human dura mater blocks were bonded together for 10 and 30 minutes with AFTA-E or AFTA-A. The blocks were then separated and the bonding power was measured. The efficacy of AFTA-E was also evaluated after a 24-hour refrigeration. SETTING: The Department of Otolaryngology Research Laboratory at the University of Illinois Eye and Ear Infirmary, Chicago, Ill. PARTICIPANTS: Blood was drawn from 86 healthy volunteers and AFTA-E and/or AFTA-A was manufactured. RESULTS: The AFTA-E was shown statistically to bond stronger than the AFTA-A. In addition, it was found that the efficacy of AFTA-E was unchanged after a 24-hour refrigeration. CONCLUSIONS: The improved AFTA, AFTA-E, is a superior alternative to the conventional AFTA-A. Furthermore, AFTA-E can be manufactured before surgery and stored, thus minimizing preparation time during surgery.

Adhesiveness↗

Stapedectomy modified by the application of fibrin tissue adhesive.

Certain failures of the stapes operation are caused by loosening of the crimped metal loop on the long process of the incus, atrophy or necrosis of the lenticular process, erosion of the long process with the prosthesis causing injury to the labyrinth, erosion of the incudostapedial joint with upward rotation of the long process, and dislocation of the prosthesis. To reduce the occurrences of these failures following stapes removal, we close the oval window by gluing a fascia graft into place with fibrin tissue adhesive. A ceramic strut with a cup on its upper end that fits the lenticular process is glued between the fascia graft and the lenticular process. This method does not cause bone necrosis or blood circulation disturbances. The hearing results are the same or better than those reported for other stapes procedures.

Animals↗

Autologous fibrin tissue adhesive: factors influencing bonding power.

Bonding power of Autologous Fibrin Tissue Adhesive (AFTA) is directly related to its fibrinogen concentration. By increasing the ammonium sulfate concentration 100% during fibrinogen precipitation, the bonding power of two glued 1-cm2 pieces of human dura almost doubled. No relationship between blood fibrinogen level and bonding power was demonstrated. Comparing AFTA with Fibrin Sealant, the commercial fibrin tissue adhesive, shearing strength between two glued pieces of human dura with AFTA was less 10 minutes and greater 30 minutes after gluing. Gluing a TORP (Richards) to a 1-cm2 piece of human dura yielded generally somewhat greater bonding power when using Fibrin Sealant. Autologous Fibrin Tissue Adhesive provides bonding power adequate for middle-ear surgery, eliminates transmission of viral diseases and, unlike Fibrin Sealant, AFTA is available in the United States.

Ammonium Sulfate↗

Otogenic intracranial inflammations: role of CT.

This article reviews the authors' results using CT in the diagnosis of 18 selected patients who were clinically suspected of having otogenic intracranial complications, demonstrating with illustrative examples the important role of CT in diagnosing various stages of acute coalescent mastoiditis and its associated complications.

Adolescent↗

Autologous fibrin tissue adhesive biodegration and systemic effects.

A series of experiments was conducted to investigate the rate of Autologous Fibrin Tissue Adhesive (AFTA) degradation by the fibrinolysis inhibitor, epsilon amino caproic acid (EACA). The duration of AFTA clots in vitro, subcutaneous, and in the middle ear was prolonged for a time interval that was proportional to the concentration of EACA in Component II of the adhesive. No toxic reactions were observed in the middle or inner ear. Systemic pathology (thrombosis or emboli) could not be related to the presence of EACA applied in the middle ear or directly into the blood stream at concentrations (mg/kg body weight) up to 1,500 times that expected to occur during surgery on humans.

Aminocaproic Acid↗

Extended experimental and preliminary surgical findings with autologous fibrin tissue adhesive made from patients own blood.

A surgical tissue adhesive can be made from the patient's own blood. We have been refining the procedures for manufacturing autologous fibrin tissue adhesive to facilitate its use in the operating room and to increase its bonding strength. Fibrin tissue adhesive efficacy depends on fibrinogen concentration. We found that fibrinogen precipitation using the ammonium sulfate method produced the highest concentration. Bonding power was compared with that of the commercial glue 10 minutes and 30 minutes after glueing two pieces of 1 X 1 cm2 human dura together. Bonding strength of the autologous product was close to that of the commercial product. Comparisons of fibrinolysis inhibition time of autologous fibrin tissue adhesive and commercial glue in experiments on rats over a period of one hour to six days after subcutaneous injection are described.

Aminocaproates↗

Fibrin tissue adhesive and glass ceramic strut for ossicular chain replacement. Electrophysiologic and histologic findings.

The tolerance of the inner ear to fibrin tissue adhesive was tested. In experimental surgery on thirty-four chinchilla ears, Fibrin Sealant was applied to the inner ear contents by closing the oval window with a connective tissue graft dipped in the adhesive and gluing a Macor glass ceramic strut between this graft and tympanic membrane. No inner ear changes or tissue damage were found. The loss in auditory sensitivity monitored by auditory brain stem response thresholds was commensurate with the amount of loss to be expected with ossicular chain replacement. The findings suggest that this tissue glue can be safely applied to the labyrinth.

Animals↗

Autologous fibrin tissue adhesive.

Various methods of making fibrin tissue adhesive from a patient's own blood were evaluated. The method using ammonium sulfate for fibrinogen preparation produced the greatest bonding strength. The average bonding strength of the commercially manufactured adhesive and of the autologous fibrin tissue adhesive were compared at 10 minutes and 30 minutes after glueing together 1 X 1 cm samples of fresh human dura. Results indicate the commercial glue holding 57 gms/cm2 at 10 minutes and 123 gms/cm2 at 30 minutes, while autologous glue prepared with the "ammonium sulfate method" has a bonding strength of 41 gms/cm2 at 10 minutes and 217 gms/cm2 at 30 minutes.

Ammonium Sulfate↗

Experimental use of fibrin tissue adhesive in middle ear surgery.

The biocompatibility of a new tissue adhesive was tested. Its major advantages are adhesions, hemostasis, and the promotion of wound healing. In experimental surgery on 43 middle ears of chinchillas, documented by histological evidence obtained 45 days after operation, the validity of the following two hypotheses was established. That fibrin tissue adhesive placed upon the footplate of the stapes is biologically compatible, biodegradable and does not cause toxic, inflammatory or foreign body reactions, or other tissue damage to middle ear structures. That a small piece of bone glued on the long process of the incus with fibrin tissue adhesive shows permanent tissue union. In addition, in cases where the inner ear was accidentally opened by surgically subluxating the stapes and adhesive was free to enter the vestibule, evidence was obtained that there was no damage to inner ear structures. This finding deserves further investigation.

Animals↗

Tissue adhesive Histoacryl (2-cyano-butyl-acrylate) in experimental middle ear surgery.

The tissue adhesive Histoacryl (2-cyano-butylacrylate) was experimentally applied to the stapes region of nine middle ears of baboons. Stapes footplate, labyrinth, and middle ear did not show any damage or injury due to the adhesive application. Only minor inflammatory reactions were observed to surround the adhesive bubbles. Histoacryl is considered safe for use in human ear surgery.

Animals↗

Facial nerve repair with tissue adhesive.

The facial nerve in dogs was exposed, transected, and repaired by either of two methods. Suture and a Silastic sheath was the control method, since a review of the literature suggests it gives the highest rate of success. A tissue adhesive (Histoacryl) was used as the experimental method. In both techniques, the surgical microscope was used. Thirteen nerves were repaired: seven with the adhesive and six with suture and Silastic sheath. Success was judged on two criteria: (1) observation of motion in the muscles that were innervated after electrical stimulation of the nerve proximal to the repair site and (2) evaluation of microanatomical continuity after removal of the repair site and preparation of slides and tissues staining. The two repair methods produced statistically equal results. The "adhesive" method can be performed with greater ease and is less time-consuming. The number of studies required for statistical reliability was determined by means of sequential analysis.

Animals↗

Heterograft Myringoplasty.

Heterograft myringoplasty on dogs was performed. Serosa of the cecum of the calf was used in eight middle ears and cadaver tympanic membrane of the calf with the malleus attached in four. All canine eardrums were healed 10 to 12 weeks postoperatively. The heterografts were then unidentifiable. In only two middle ears did a mild inflammatory reaction occur with serosa grafts, but in three of the four middle ears with cadaver eardrum grafts, severe inflammation and scarring appeared. The attached denatured calf malleus was being remodeled into a canine ossicle by new bone deposits. The results with calf serosa graft indicate that tolerance and survival might be expected using it in the human ear. However, the experiences with the calf cadaver tympanic membrane suggest a need for great caution in expanding the present information to surgical use in the human.

Animals↗