Homograft Tympanic Membrane Research Articles

Homograft (allograft) tympanoplasty update.

If homograft tympanoplasty is to be of value, specific instances in which homograft tympanic membrane, malleus, and incus (TMMI) provide significant hearing and anatomical advantages over standard techniques should be identified. This author has performed 305 homograft tympanoplasties limited to the reconstruction of the severely damaged middle ear. Indications include: previous failure with standard tympanoplasty techniques; high risk of anatomic or hearing failure with standard techniques (total perforation with absent malleus, slag burns); reconstruction of radical mastoidectomy; congenital aural atresia. The first 125 consecutive homograft tympanoplasties were reported in 1982. One hundred eighty additional homograft tympanoplasties have been performed since then. In the past 3 years the anatomic success rate has risen to 97% (174/180) with refinement of surgical techniques. Eighty-five percent of all patients have maintained an average air-bone gap of 25 dB or better. Formalin preserved homograft tympanic membranes with attached malleus offer significant advantages over standard tympanoplasty techniques in these specific indications.

Reconstruction of hearing when malleus is absent: Torp vs. Homograft tmmi

To study the most appropriate ossicular reconstruction of patients with an absent malleus, a comparison was made utilizing a homograft tympanic membrane with attached malleus and shaped incus (TMMI) columella and the alternative use of underlay fascia tympanoplasty with a cartilage covered TORP. Forty-six patients were reconstructed with a homograft TMMI and 38 with cartilage covered TORP and underlay fascia technique; 4.5 years postoperatively, 84% of those patients reconstructed with a homograft TMMI maintained an average A/B gap of 25 dB or better. Though 1 year postoperatively the TORP hearing results were satisfactory, only 18% of the TORP patients maintained a hearing level within 25 dB A/B gap at 4 years postoperatively. Primary causes of failure of the TORP were instability with migration off the stapes footplate, protrusion or extrusion through the TM and finally, long-term softening and bending secondary to biodegradation of the Plastipore. The discouraging long-term hearing results found in the TORP patients in this study confirm similar findings reported in 1982 by Smyth in a 5 year follow-up on 116 TORP patients.

Homograft tympanoplasty in perspective. A long-term clinical-histologic study of formalin-fixed tympanic membranes used for the reconstruction of 125 severely damaged middle ears.

This seven and a half year clinical-histologic study evaluates the effectiveness of buffered, formaldehyde-fixed homograft tympanic membranes for reconstructing the severely damaged middle ear in 125 consecutive patients. Indications for use of homograft tympanoplasty were limited to those cases in which standard tympanoplasty had already failed to produce a satisfactory hearing or anatomic result (i.e., recurrent perforations or draining radical mastoidectomy cavity), or to those cases in which there was a high risk of unsatisfactory result with standard tympanoplasty techniques (i.e., total perforation with absent malleus or congenital aural atresia). Anatomic data was documented with serial postoperative photomicrography. Audiograms were performed at yearly intervals and long-term hearing results were analyzed. Histologic studies were performed on 2 homograft tympanic membranes removed 6 months and 6 years postoperatively. Postoperative photographs of the healing donor tympanic membrane and histologic studies confirmed that the homograft collagen attracts host angioblasts, fibroblasts and epithelial cells. The initial inflammatory response (primarily lymphocytic) subsides and the host produces collagen and elastin fibers interspersed among the donor collagen. Gradually the donor collagen is resorbed. At the completion of this study, 95% (119/125) of the homograft tympanoplasties are currently intact. There were 13 immediate postoperative perforations, but 11 were repaired with a second stage underlay fascia tympanoplasty. Long-term hearing results were analyzed according to the type of ossicular reconstruction employed (mean follow-up 4 years). In 87 patients with chronic otitis media, 94% of the type I repairs maintained an air-bone gap of 25 dB or less, 85% of the type II, and 81% of the type III. Forty-four patients presented with an absent malleus and absent tympanic membrane and were reconstructed with a homograft tympanic membrane with attached malleus and a shaped incus columella. At 4 years postoperatively, 83% of these patients maintained an average air-bone gap of 25 dB or better. A similar group of 38 patients presenting with absent malleus, incus, and stapes were reconstructed with isograft temporalis fascia and a cartilage covered TORP. Only 18% of the TORP patients maintained an air-bone gap of 25 dB 4 years postoperatively. Thirty-three patients with draining radical mastoidectomy cavities were reconstructed; 97% (32/33) had a dry, self-cleansing ear with no activity restriction. Only 59% maintained an air-bone gap closure of 25 dB or better in the long-term follow-up; 30% (10/33) developed persistent eustachian tube dysfunction, usually in the second through fourth postoperative years.(ABSTRACT TRUNCATED AT 400 WORDS)

Complications of Homograft Tympanoplasty

The use of a homograft tympanic membrane with an attached malleus has provided an excellent alternative for reconstructing the severely damaged middle ear. I have limited homograft tympanoplasty to four specific indications: previous failure of standard tympanoplasty techniques, high risk of failure (total perforation, absent malleus, slag burns), reconstruction of radical mastoidectomy, and congenital aural atresia. Homograft tympanoplasty has provided a 94 per cent incidence of anatomic success in these severely damaged middle ears. Closure of the air-bone gap to within 25 dB. was accomplished in 85 per cent of these patients. Complications must be viewed in the perspective of the extensive disease in the middle ear that was being reconstructed. Only meticulous attention to surgical technique and postoperative care will provide the successes described by Wehrs, Marquet, Perkins, and others. The otologic surgeon is urged to observe the surgical techniques of homograft tympanoplasty rather than merely read about it. I believe that the transplant tympanic membrane should be used only when it provides an advantage over standard grafting techniques. Underlay fascia tympanoplasty yields excellent results in the majority of eardrum reconstructions. A final word about homograft tympanic membrane and ossicles. Although several "banks" for ear tissue are available in the United States, there are few established guidelines that these banks are required to follow. The otologic surgeon who uses homograft tissue must be guaranteed that the biologic product he is implanting in his patient is sterile, is anatomically perfect, has been stored in a chemically stable preservative, and has proven biologic effectiveness. Ear banks should be managed by surgeons who are using that tissue in their own patients, thus monitoring the tissue's quality. Each bank has a responsibility to donors, recipients, and surgeons to maintain the highest laboratory standards that will guarantee the quality of its product. Since there is no regulating agency, the practicing physician should insist that these standards for processed homograft ear tissue be maintained.

The homograft tympanic membrane after 12 years.

The homograft tympanic membrane has been utilized in reconstructive middle ear surgery since 1968. Previous reports describing its preservation and use were published in 1971, 1972, 1976 and 1978. Throughout this time the same preservative of 70% ethyl alcohol and the same surgical technique of covering the transplant with canal skin or fascia has been employed. These transplants have been used to supplement, not replace, other grafting tissues, and to improve the graft-take rate and hearing results. The graft-take rate has averaged over 90% for the past 12 year and 98% for the past 5 years. The hearing results have been satisfactory in 69 to 95% of the cases depending on the associated ossicular reconstruction. Furthermore these results have been consistent and have not deteriorated with the passage of time.

Controversies in surgery of chronic otitis media

draining ears and dry ears and that sensorineural hearing impairment should not result from the mere process of grafting the tympanic membrane. The major area of disagreement is in regard to the technique of grafting : underlay (under surface), overlay (outer surface) and use of homograft tympanic membranes. There are problems with each technique. It is apparent that the results with each are comparable in the hands of those who have used each procedure extensively. They know the problems associated with their procedure and how to avoid them in most cases. The novice will find that the most important element in his success rate is how well he uses the technique, not which technique he uses. At the Otologic Medical Group (OMG) we prefer the overlay technique, but use an underlay on occasion.(l)

Homograft Tympanoplasty

Otoadmittance measurements and air- and bone-conduction thresholds were obtained for 20 subjects who underwent type I tympanoplasty. Component tympanometry, particularly with a high-frequency probe tone, demonstrated that homograft tympanic membrane transplants exhibited more normal function than did temporalis fascia grafts. Audiometric results revealed greater hearing improvement by the homograft transplant group.

Results of reconstructive mastoidectomy with homograft knee cartilage.

The technique of reconstructing the posterior canal wall with homograft knee cartilage originally described in 1972 is reviewed and refinements are presented along with additional cases. The homograft knee cartilage is used in conjunction with the homograft tympanic membrane and ossicles to rebuild the middle ear and mastoid as near as possible to anatomical configuration and function. Anatomical follow-up of one year or more is reported on 63 ears. Satisfactory results were obtained in 36 of these ears or 57% of the total. Hearing results are reported overall and in relation to different types of reconstruction. One year or more follow-up demonstrates satisfactory hearing with an air-bone gap of 20 db or less in 77% of the postoperative ears.

Results of homografts in middle ear surgery.

Anatomical and hearing results following the use of the homograft tympanic membrane and ossicles either in combination or separately are reported for the period 1968 through 1975. The study is divided into two parts, the first covering the primary years 1968 through 1971, and the latter covering the last four years, 1972 through 1975. The original technique was to cover completely the homograft tympanic membrane with a canal skin graft. During the year 1969 new and different techniques were attempted. Unfortunately this resulted in a marked increase of graft failures; therefore, there was a prompt return to the original technique, which has been used without change throughout the study. The graft take rate for the first four years which included 1969 was 92%. There was a slight increase to 96% during the second part of the study. The hearing results show a greater discrepancy for the two periods with 89% of the patients receiving a satisfactory hearing result during the last four years, compared to 77% for the earlier period.

Experiences in homograft membrane tympanoplasty.

Experience of a short series of 37 cases of tympanoplasty involving the use of a homograft tympanic membrane is presented, with a discussion of the problems involved. The initial results correspond to the earlier series' anatomical success rates and indicate that these grafts will become widely used as an effective method of tympanoplasty.

Hearing and Anatomical Results with Homograft Tympanoplasty

Homograft tympanic membranes and ossicles have been found to be a valuable asset in tympanoplasty surgery. The homograft tympanic membrane has been used in conjunction with a canal skin graft with a graft take rate of 94 per cent. Anatomical results have been gratifying in that most patients are totally rehabilitated and may swim or shower without restrictions. The homograft incus has been sculptured into prostheses to reconstruct the sound conduction mechanism, both at the initial procedure and in revision cases to improve the hearing.

The homograft myringoplasty and the lamina propria of the tympanic membrane

The lamina propria of the tympanic membrane is composed of a unique system of radial and nonradial fibers which contribute importantly to its function. Over 1000 patients have undergone operations for the transplantation of the homograft tympanic membrane. Animal experiments have been presented to determine whether or not the fiber system of the lamina propria of the tympanic membrane is preserved in the homograft tympanic membrane. In conjunction with this, a small series of experiments was conducted to determine the appearance of the fiber system in perforations that heal spontaneously. Current knowledge concerning the function of the fiber network is discussed. The results of the present study indicate that the lamina propria fiber network is at least partially preserved in the homograft tympanic membrane and that the fiber network of the lamina propria is not reconstituted in spontaneously healed tympanic membranes.

Homograft Tympanoplasty Techniques and Results for Restoration of Hearing

The use of a homograft tympanic membrane with and without attached ossicles, staging the operation, and the use of sculptured homograft or autograft ossicles have improved the results in tympanoplasty. The indications and techniques of homograft tympanoplasty are described, and the results in 99 primary cases and 11 cases with repair of a mastoid cavity are given. The overall graft success rate was 86 per cent. In patients with an intact ossicular chain, the conductive loss was reduced to less than 20 dB. in 88 per cent. A hearing loss less than 20 dB. was obtained in 68 per cent with an intact stapes, in 77 per cent when the stapes superstructure was absent, and in 79 per cent in stapedectomy done at a second stage. The use of homograft material has provided the means for significantly improving the results in our patients who require tympanoplasty.

Homograft tympanic membrane myringoplasty.

During a six-year period, homograft tympanic membranes have been used successfully for myringoplasty or tympanoplasty in 85% of 175 cases. This percentage is not as high as might be expected with fascia, and the homografts have not been as dependable in the wet, draining ear. However, the results do show that the homograft is an acceptable grafting material. The eardrums are not suggested as substitutes for fascia, but should be available for difficult cases. Their use is indicated in large or total defects to restore the natural anatomical conical shape of the eardrum, particularly in congenital atresia. The prime indication for their use is a missing malleus, and the malleus handle can be included within the transplant. The eardrum's rigid properties and the possibility of inclusion of ossicles make the homografts valuable in reconstruction of the old mastoid cavity.

Tympanomastoid reconstruction: an operative procedure for anatomical and functional restoration of the radicalized ear.

A new operative procedure for the anatomical and functional restoration of both the middle ear and mastoid is described. The technique employs homograft tympanic membrane with ossicles en bloc for the middle ear reconstruction and a homograft dura form and autogenous bone pate is used to recreate the bony posterior ear canal wall. The reconstructed wall becomes hard viable bone in about one year. Results in terms of wall integrity, tympanic membrane survival and hearing are discussed. The mechanism of new bone formation is discussed with presentation of histologic findings.

Homograft replacement of the tympanic membrane.

This paper presents the authors' experiences with one method of reconstruction of the tympanic membrane when it is totally absent or when there is a fixed, retracted, defective, or absent malleus. Ten patients undergoing surgery for chronic suppurative otitis media between April, 1971, and January, 1973, had homograft tympanic membranes and/or ossicles used to reconstruct the defect in the tympanic membrane or ossicular mechanism. The patients had certain clinical and surgical characteristics in common: 1. all had either an absent tympanic membrane or almost total perforation of it; 2. all were operated upon in the absence of acute infection or active drainage; cholesteatoma, if present, was totally removed; 3. all had patent eustachian tubes; 4. all had intact middle ear mucosa at the time of utilization of the homograft; 5. all patients were operated upon by the same surgeon; 6. all of the homografts were obtained within 24 hours and were used within one month after the death of the donor; 7. all of the homografts used had been preserved in 70 percent ethyl alcohol; 8. all of the homograft materials came from donors who were under 40 years of age at the time of death and who died of accidental causes. (None of the donors was known to have any pre-existing disease); 9. all homografts, after being placed in proper position in the recipient, were covered with ear canal skin; 10. all patients received homografts that were from the corresponding ear of the donor. (In other words, right ear homografts were used in the patient's right ear, etc.); 11. whenever the tympanic ring was greater than the size of the homograft, the patient's temporalis fascia was used in conjunction with the homograft tympanic membrane to bridge the defect; 12. all patients had the middle ear packed with gelfoam prior to inserting the homograft (compressed gelfoam was used also for the outer packing); 13. none of the patients had tissue-typing procedures carried out in an effort to match the donor and the recipient, nor was any attempt made to match the sex of the donor and the recipient; and 14. all patients received antibiotics postoperatively; however, none received immunosuppressive therapy postoperatively. In 3 of 10 patients receiving homografts, the malleus was normal, and only the tympanic membrane was reconstructed. In seven others there was a fixed, retracted, defective or absent malleus in addition to the tympanic membrane defect.(ABSTRACT TRUNCATED AT 400 WORDS)

Reconstructive mastoidectomy with homograft knee cartilage.

AbstractDuring the past decade the trend in surgery on the mastoid segment of the temporal bone has been toward restoration of function and normal anatomical configuration. The primary preservation of the posterior bony canal wall with aeration of the mastoidectomy cavity has eliminated many of the problems associated with an open cavity. The likelihood of good hearing increases when the support for the posterior and superior portions of the tympanic membrane are preserved; however, there are many patients whose surgery included removal of this bony barrier and exposure of the mastoid segment to the outside. It is for these patients that a means has been sought to eliminate the cavity and reconstruct the hearing mechanism.Previous techniques have sought to eliminate the mastoidectomy cavity by obliteration with muscle pedicles, fascia, cartilage and bone. All these techniques tend to modify rather than to reconstruct nature's plan of the middle ear and mastoid. It would seem more physiologic to rebuild these structures as nearly as possible in their normal anatomical relationship and function. It was with this goal in mind that the herein described technique of knee cartilage reconstructive mastoidectomy was developed.A review of the literature revealed that in 1940 cartilage homografts were being used in rhinoplasty by Brown. This author preserved the cartilage in alcohol because it was “simple and safe.” Homograft nasal septum cartilage had been utilized in tympanoplasty by Smyth and Jansen and in otosclerotic surgery by Pfaltz. No previous article referring to the use of knee cartilage for transplantation could be found.Homograft knee cartilage was discovered to possess the gentle curve and thin lower border characteristic of the posterior bony canal wall. With this support the homograft tympanic membrane may be used to reconstruct the drumhead in normal anatomical position. The homograft incus then becomes a prosthesis to rebuild the conduction mechanism in this one stage operation. Silastic sheeting from the eustachian tube to the mastoid antrum prevents adhesions and assures aeration of these structures. Likewise, mucoid discharge from the remaining mastoid cells finds its way to the eustachian tube and nasopharynx.Fifteen ears have been reconstructed by this technique. All cases have healed completely and uneventfully with no infection or extrusion of the knee cartilage transplant. Postoperatively the ear canal and drumhead have an almost normal appearance, and epithelial migration keeps these structures clean and functioning. Hearing improvement has been gratifying with a return to normal in some instances. Three case presentations are included as examples of the procedure.

Homograft transplants to the middle ear. A follow-up report.

AbstractIn April, 1967, we performed our first transplant of a homograft tympanic membrane in a case of chronic ear disease. This work was presented in a “Preliminary Report” in January, 1968. The purpose of this paper is to give our experience (almost five years) with this technique of tympanoplasty.Our initial investigation was fraught with many difficulties. At the beginning of the project there were no clear cut legal priorities for obtaining and using cadaver material. No specific or generally accepted preservation solution was available, and the best method of storage was yet to be determined.The aim of the series was to develop a method of grafting the drum in patients with chronic ear disease. In addition, it was our hope that by incorporating the intact ossicles as well we would be able to increase the hearing in those difficult cases in which all ossicular remnants had been destroyed.While our original results were encouraging, the long term evaluation has been somewhat disappointing. The overall take rate for the drums has dropped to 65 percent. Hearing results are approximately the same as for any standard tympanoplasty procedure, no worse, but certainly no better.Since the beginning of our series other investigators have begun to use the technique with considerable more success. Perkins has been able to raise the take rate to 90 percent (acceptable) by using a buffered Formalin solution. The passage of the Uniform Donor Act has made homograft tissues more available and opened the way for the new national ear bank programs.While our experience has been disappointing, we feel we did help to stimulate interest in this procedure and that many of our failures have since been corrected by other investigators. We feel the future is good for homograft transplants to the middle ear and will continue to improve on our own techniques as well as those of others.

Three years' experience with the homograft tympanic membrane.

Three years' experience with the homograft tympanic membrane.

Homograft tympanic membrane in tympanoplasty.

Homograft tympanic membranes appear to meet the requirements of ideal tissue transplants. The surgical technique herein differs from that previously reported in that the homograft tissue is not used alone but is overlayed with canal skin or fascia. This maneuver utilizes the homograft tympanic membrane as a supporting scaffold to maintain anatomic shape and position of the drum head while the skin or fascia serves to assure rapid epithelization. In ears where all ossicular tissue has been destroyed the homograft tympanic membrane with attached malleus provides the main building block for reconstruction of the hearing mechanism. The initial hearing results are good and all indications are that they will be maintained with the passage of time.