Homologous Grafts Research Articles

Experiences with the Mittelmeier ceramic screw acetabulum in exchange operations for loose endoprostheses

This is a report about our experience with the replacement of loosened acetabular endosprotheses by the self locking ceramic Endoprosthesis Mittelmeier. That's an analysis of 60 patients concerning age, sex incidence, indications, primary implant type and long term findings. The clinical findings are illustrated according to the schedule of Merle d' Aubigné. The critical evaluation shows, that the self locking ceramic cup allows the additional implantation of homologous or autologous bone chips and grafts avoiding further allogenous implants.

Substitutos ósseos comparados ao enxerto ósseo autólogo em cirurgia ortopédica: revisão sistemática da literatura

OBJETIVO: Identificar, a partir de revisao sistematizada da literatura, estudos clinicos com nivel de evidencia 1 comparando substitutos osseos ao enxerto autologo. METODOS: Realizada busca eletronica de artigos que comparassem o uso do enxerto osseo autologo a um substituto osseo em cirurgia ortopedica. Foram considerados como criterios de elegibilidade ensaios clinicos prospectivos e randomizados em cirurgia ortopedica, com casuistica minima de 20 pacientes, envolvendo ossos da coluna vertebral ou esqueleto apendicular, publicados entre janeiro de 1990 e janeiro de 2006. RESULTADOS: Foram identificados 22 trabalhos, todos em lingua inglesa, dos quais cinco compararam enxerto autologo ao homologo, sete envolveram uso de proteina morfogenetica do tipo 2 (BMP-2), em tres foi avaliada a proteina morfogenetica do tipo 7 (BMP- 7) e sete utilizaram biocerâmicas, como hidroxiapatita, fosfato tricalcio e sulfato de calcio. Os resultados mais sugestivos da equivalencia com o enxerto autologo se deram nos trabalhos com BMP-2 em cirurgia da coluna vertebral, embora diversos questionamentos possam ser feitos em relacao a estes e aos demais estudos analisados, referentes a metodos e possiveis conflitos de interesses. CONCLUSAO: Existem poucos estudos com alto nivel de evidencia que demonstrem a aplicabilidade clinica dos substitutos osseos atualmente existentes.

Fresh frozen homologous bone in oral surgery: case reports

Intraoral bone defects may be treated using autologous grafts, homologous grafts, heterologous grafts or synthetic products. Autologous bone is now considered the gold standard for bone grafting procedures. Homologous fresh frozen bone, provided by bone banks, is frequently utilized by orthopaedic surgeons because it is considered a safe material from immunological and viral points of view. In the cases reported here, homologous bone was used to repair some osseous defects without changing the surgical protocol utilized for autologous bone procedures. The main advantages of this strategy are low morbidity, shorter surgical times, more comfort and less risk of infection for the patient as well as the greater availability of bone.

Morphologic changes in the canine urinary tract after ureteral reconstruction with the tunica albuginea (experimental study)*

The problem of ureteral reconstruction has not been fully solved, despite dramatic developments in surgical methods. Many attempts to repair a ureteral damage with autologous or homologous organ grafts, or with organic substitutes have not really been satisfactory. Also, attempts to use alloplastic and heteroplastic prostheses made of synthetic materials have been equally disappointing. Experimental studies, particularly in dogs, indicate great regenerative abilities of ureters when appropriate surgical techniques are used. In our experimental study, suitability of the tunica albuginea for reconstruction of the middle part of the ureter was investigated in 20 dogs. The dogs were divided into two groups according to a type of ureteral damage: partial (a patch graft) or complete (a tube graft). The ureteral damage was 2-3 cm long in 10 dogs and 3-3.5 cm long in the subsequent 10 dogs. Each dog underwent two operations. The first operation involved a fenestrating incision in the ureter, 23.5 cm long, so as to preserve the ureteral continuity, and then the produced injury was repaired with a patch of the tunica albuginea, with the 4 Charr catheter being inserted in the ureter. The second operation involved a complete excision of ureteral segments, 2-3.5 cm long, on the contralateral side. The excised length of the ureter was substituted with a tube graft of the tunica albuginea, also using the 4 Charr catheter. Thus, in 21 cases, a partial damage of the ureteral wall was repaired with a patch graft of the tunica albuginea. In 19 cases, a complete damage of the ureter was repaired with a tube graft of the tunica albuginea. Four dogs died after the tube-graft implantation due to urinary infiltration and/or purulent inflammatory changes in the kidneys. Autopsies were performed in all the dogs after they had been put to sleep. Definitely poor results were obtained in case of the complete reconstruction of the ureteral loss with a tube graft of the tunica albuginea, 3-3.5 cm long. Within the graft area, we observed inflammatory infiltrates of varied intensity, fibrosis, cicatricial strictures or ureteral obstruction. Occasionally, necrotic foci, degenerative changes or hydronephrosis were found. In case of the reconstruction with a shorter tube graft, i.e. 2-3 cm long, similar changes were observed, however, they were less intense. Satisfactory results were obtained following the partial reconstruction of the ureteral loss with a patch graft of the tunica albuginea. In this case, we observed generally normal regeneration not only of the transitional epithelium but the muscular layer and ureteral structure as well, with full patency of the ureter preserved. The findings obtained in our study are compatible with the findings of other authors. (1) The success of reconstructive procedures in the ureters can be achieved if the continuity of the ureter is preserved and the catheter is removed after 14 days. (2) The substitution of a complete ureteral loss with a tube-graft of the tunica albuginea results in necrosis of the graft and restenosis.

Tympanoplasty: Surgical results and a comparison of the factors that may interfere in their success

SummaryChronic otitis media has a high prevalence on the population and their treatment continuous to be a challenge for the otorhinolaryngologists. Aim: To demonstrate the factors that could interfere in the tympanoplasty success and the surgical results during 2002. Study Design: Clinical prospective. Material and Method: were included 37 patients with chronic otitis media non cholesteatoma (COMNC) undergo to tympanoplasty (in lay or underlay, with homologous graft). All the patients were submitted to a survey pre and postoperative include clinical, physical examinations, flexible nasal endoscope and audiometry. Results: The age, the dimension and localization of the tympanic membrane perforation; the condition of middle ear mucosa; number of otorrhea/year; smoking; parents history of otorrhea and hearing loss; personals history of otological surgery; monthly family income; the graft, technique and access used were not significantly to repair tympanic membrane perforations. The closure rate was 65% and the gain in air-bone gap was 100%. Conclusion: The timpanoplasty must be considerate in the treatment of the COMNC.

Blood flow study of arteriovenous grafts with homologous and autologous veins in canine femoral vessels

The objective of this study was to assess the blood flow in arteriovenous (AV) communications comparing autologous and homologous veins, in the femoral vessels of dogs. Ten mongrel dogs were used for the blood flow analysis, and two AV grafts (AVG) were placed in each of them. The grafts were made with an autologous vein in one side, and a omologous vein, kept in a 0.25% glutaraldehyde solution, in the other side. The volumetric flow was measured before and after AVG placement. Fifteen minutes after surgery, the volumetric flow was measured in the cranial artery, in the caudal artery, in the graft and in the vein, and the same procedure was repeated 15 days after surgery. Measurements were done using an eletromagnetic flowmeter calibrated previously. For data analysis, the Wilcoxon test was used (to compare the difference in the results between the times and the techniques used) alfa </=0.05). An increase of about 5.3 times was observed in the femoral artery cranial portion flow of these accesses during the first operation and an increase of 6.8 times in the re-operation for both techniques. In the femoral artery caudal portion of the AVGs there was a blood flow inversion of about 1.6 times for both techniques during the first operation and about 4.1 and 3.7 times for the autologous and homologous veins, respectively. There was a significant increase in the autologous grafts. In the cranial portion of the femoral vein, there was an increase in the flow in relation to the femoral artery flow before graft placement. There was an increase of 5.3 and 7.4 times for the autologous and homologous grafts, respectively, in the first operation and from 8-9.6 times in the re-operation. There was also a significant increase in the autologous graft in relation to the two procedures. A significant difference among the grafts placed during the first surgery was observed, which was not observed after 15 days. In the graft blood flow analysis, a flow increase of 5.1 times for the autologous vein and 6.6 times for the homologous vein and from 7.5-8.2 times in the re-operation was found in relation to the femoral artery flow. There was a significant increase in autologous vein flow between the first operation and the re-operation. The mean blood flow of the homologous AVG was greater during the first operation and similar to the autologous grafts during the re-operation. Therefore, the homologous AVG could be considered a possible alternative to vascular access for hemodialysis.

Reconstruction of chest wall defects with homologous dura mater grafts

Reconstruction of chest wall defects with homologous dura mater grafts

Homologous dermal acellular matrix graft for urethral reconstruction in man (report of 16 cases)

To investigated the value of homologous dermal acellular matrix graft (AMG) for urethral reconstruction in man, and found an ideal replacement material to simplify the urethroplastic surgery. 16 male patients, aged 18-46 (mean 26.5), with urethral diseases were treated with allograft of tissue engineering material AMG. The causes of urethroplasty were complex urethral stricture followed by pelvic fracture (13 cases), anterior urethral stricture (2 cases), hypospadia (1 case). During the operation, AMG was sutured to a tubular graft and replaced the defect urethra. A 18-22 Fr silicone catheter was inserted in the reconstructed urethra for 4-6 weeks. All 16 patients were voiding well after removing the catheter, urethrography reveal excellent caliber of the reconstructed urethra. Urethroscopic examination showed the graft urethra was covered by epithelial tissue and grew into the native tissue. But stenosis was developed in 3 patients postoperatively, 1 patients received transurethral incision, another 2 needed urethral sounding. The patients were followed-up for 12-72 months (mean 45.6), no rejection was observed, all patients voided normally except 4 cases needed urethral dilatation periodically. The homologous dermal acellular matrix graft may serve as an ideal replacement material for complex urethral stricture or defect, without concern of rejection.

Viability of a 12‐Ring Complete Tracheal Segment Transferred in the Form of a Compound Flap: An Experimental Study in Dogs

There is a lack of an ideal substitute for the injured tracheal tissues. Autologous or homologous grafts and prostheses are inadequate because of their unreliable and nonviable nature for the reconstruction of a complete tracheal segment (CTS). We studied the viability of a 12-ring CTS transferred in the form of a compound flap from the sternohyoid muscle (SM) for tracheal reconstruction. Sixteen mongrel dogs of both sexes were divided into two groups of eight dogs each. In group I (control), a 12-ring CTS was removed and then reimplanted as an autograft. In group II, an SM flap was used to envelop four rings of the CTS to produce a compound CTS flap neovascularized by the SM (CTSNV). After 21 days, a 12-ring CTSNV, consisting of the four rings previously covered with SM, four rings above, and four rings below (without muscle covering), was sectioned and completely separated from the trachea. The CTS was then reimplanted at its original site, with the SM being the only vascular supply pedicle for the flap. The results were evaluated clinically and by macroscopic and microscopic examination of the surgical specimens. All the animals in group I (control) died or were killed by the first or second week because of necrosis and stenosis of the CTS graft. In group II, all animals were killed after 77 days of follow-up without showing any alteration in the CTSNV. We conclude that a compound 12-ring CTSNV flap remains viable and can be mobilized from the trachea without the risk of necrosis or stenosis.

Outcome of Rotational Keratoplasty

The nature of chronic endothelial cell loss in homologous corneal grafts is still unclear. Possible causes are cell migration to the recipient bed and chronic subclinical immune reaction. To compare endothelial cell loss after autologous rotational keratoplasty and homologous keratoplasty and present the clinical outcome of patients after rotational keratoplasty. In this open prospective study, we included 7 consecutive patients who underwent rotational keratoplasty between 1998 and 2000 in our hospital. Patients were examined clinically every 3 months, and visual acuity, astigmatism, and endothelial cell density were evaluated. Endothelial cell densities were compared with endothelial cell counts of 293 homologous keratoplasties. Mean follow-up for autologous grafts was 39 months. Mean increase in visual acuity was 3.5 lines. Mean astigmatism was 4.75 diopters in the autologous graft group. Mean preoperative endothelial cell density was 2058 (637 cells/mm(2)). Mean endothelial cell density after 1 year was 1865 (639 cells/mm(2)), which represents a mean +/- SD cell loss of 15% +/- 7.19%. At the end of follow-up, endothelial cell number after autologous grafting was 1630 +/- 622 cells/mm(2). Endothelial cell loss after 1 year in homologous grafts was 40% +/- 21.34%. There was 1 decompensation of autologous graft in the follow-up period. Main Outcome Measure Comparison of endothelial cell count at different postoperative time points using nonpaired t test. Endothelial cell loss in autologous grafts is significantly lower than in homologous grafts, which supports the hypothesis that chronic endothelial cell loss is due to chronic subclinical immune reactions in homologous grafts. Autologous keratoplasties can lead to good functional results and can be superior to homologous corneal grafting in suitable situations.

Induction of osteogenesis by demineralized homologous and xenograft bone matrix

The osteogenesis induction by demineralized bone matrix grafts remains as a challenge in the reconstructions of the mandible through homologous and xenografts or in implants in abdominal muscle. PURPOSE: Observed the behaviour of implants of demineralized bone matrix at the mandible (right side with homologous graft and left side with xenograft of pig). METHODS: Experimental study with homologous and heterologous implants of demineralized bone matrix at the mandible and in ectopic muscle at the Center of Experimental Surgery of Heliopolis Hospital, Hosphel, São Paulo, Brazil. In 6 white New Zeland rabbits, 46 grafts were performed being 23 with homologous (rabbit) and 23 with xenograft (pig). 12 homologous implants (6 at the right side of the mandible and 6 at abdominal muscle of the rabbit) and 12 heterologous implants of pigs (6 at the left side of the mandible and 6 at abdominal muscle rabbit) were performed with demineralized bone matrix. RESULTS: Osteogenesis was assessed through histologic features after 30 and 60 days. After 1 rabbit dead, osteogenesis (mandible) were detected in 9 of 11 (82%) rabbits that received homologous matrix, in spite of heterologous implants showed osteogenesis in 6 out of 11 (54%) (p=0,18). The abdominal muscle showed induced osteogenesis in 3 out of 11(27%) animals with homologous and 0% with heterologous implants (p=0,10). CONCLUSIONS: Osteogenesis induction through homologous grafts in rabbit mandible and abdominal muscle were more effective than xenografts.

Mechanical comparative analysis of three different types of sutures in different dimensions tendons - experimental study

The authors present sixteen patients with congenital kyphosis treated by posterior spinal arthrodesis. A homologous or autogenous iliac bone graft was used. The patients walked with Risser-Cotrel body cast in the 6 months of postoperatory period. The mean time of follow-up was 58,25 months and the mean age of the patients at time of surgery was 9,3 years. The mean angular value of the congenital kyphosis before surgery was 50,44º Cobb and after ther surgery it was 46,94º Cobb. One of the patients who had curve of 69º Cobb, presented pseudoarthrosis. The final results were good in 10, regular in 4 and bad in 2 patients. The need of the diagnostic and precocious treatment is recommended by authors.

Colour Atlas of Ophthalmic Plastic Surgery

Anthony G. Tyers and J. Richard O. Collin Colour Atlas of Ophthalmic Plastic Surgery, 2nd ed.360 pagesButterworth Heinemann, Oxford, 2001.Isbn 0750642548Price: £ 130.00 The first edition of this atlas appeared in 1995. In the second, the authors' have revised the text and added previously omitted procedures and newer techniques like the use of hard palate grafts. Homologous grafts, especially donor sclera, have given rise to great concern (or even become abandoned) in many states. Although still useful, alternative materials are presented in this edition. Introductory chapters cover relevant anatomy, evaluation, anaesthesia, instruments, and basic surgical principles. The 13 following chapters focus on lid surgery; there are also thorough descriptions of enucleation/evisceration and socket reconstruction and a brief chapter on orbital decompression. The authors have selected well documented procedures for the treatment of all frequent and many less often occurring conditions. The text is brief, logical and extremely clear, and there should be little difficulty to follow the course recommended. Colour photographs of superb quality illustrate almost every step of the operations. It is self-evident that the reviewer does not agree with all the authors' opinions. I would sometimes select less elaborate techniques (e.g. for a lateral tarsorrhaphy) and I never use Frost sutures after ptosis surgery, a spacer for upper eyelid retraction, etc. I can neither accept the general recommendation of a dressing after lid surgery. There are minor errors of no practical importance, e.g. the so-called Kuhnt-Szymanowski operation which is not the original one but a late modification. Of somewhat greater importance for the less experienced surgeon is the slightly confusing order of presentation of tumour surgery. Also, I do not think that many of those buying this book would (or should) perform a Mustardé cheek flap. In its place, the Hewes laterally based tarsoconjunctival flap and the tarsomarginal flap of Hübner could have been detailed. This is minor criticism; the surgeon who operates according to the book will do a prime job. When asked to recommend a manual for oculoplastic surgery, I have earlier most often suggested the first edition; the second one is even more recommendable.

HETEROLOGOUS ACELLULAR MATRIX GRAFT FOR RECONSTRUCTION OF THE RABBIT URETHRA: HISTOLOGICAL AND FUNCTIONAL EVALUATION

Purpose: In a rabbit model we evaluated urethral replacement by a free heterologous dog acellular matrix graft and compared these results with those of a homologous graft with the exclusion of antigenicity as a major goal.Materials and Methods: In 14 male New Zealand rabbits a 0.8 to 1.1 cm. segment of urethra was resected and replaced with a tubular acellular 1.0 to 1.5 cm. (mean 1.3) urethral matrix graft placed on an 8Fr feeding tube. Seven animals received a rabbit graft, 7 received a canine graft and 3 untreated rabbits served as controls. All animals underwent urethral pressure profile determination and retrograde urethrography before 8 and 6 were sacrificed at 6 and 8 months, respectively. Grafted and normal specimens were evaluated by histological testing.Results: In all animals the acellular matrix graft remained in its original position. Histological examination showed complete epithelialization and progressive vessel infiltration. At 6 months more than a third of the homologous grafts had smoot...

Heterologous acellular matrix graft for reconstruction of the rabbit urethra: histological and functional evaluation.

In a rabbit model we evaluated urethral replacement by a free heterologous dog acellular matrix graft and compared these results with those of a homologous graft with the exclusion of antigenicity as a major goal. In 14 male New Zealand rabbits a 0.8 to 1.1 cm. segment of urethra was resected and replaced with a tubular acellular 1.0 to 1.5 cm. (mean 1.3) urethral matrix graft placed on an 8Fr feeding tube. Seven animals received a rabbit graft, 7 received a canine graft and 3 untreated rabbits served as controls. All animals underwent urethral pressure profile determination and retrograde urethrography before 8 and 6 were sacrificed at 6 and 8 months, respectively. Grafted and normal specimens were evaluated by histological testing. In all animals the acellular matrix graft remained in its original position. Histological examination showed complete epithelialization and progressive vessel infiltration. At 6 months more than a third of the homologous grafts had smooth muscle bundles but the heterologous grafts had only poorly disseminated smooth muscle. Picrosirius red stain demonstrated a shift in the ratio of collagen types I-to-III with an increase in type III in the processed homologous and heterologous matrices that did not change significantly postoperatively. At 8 months the urethral pressure profile detected no difference in control and matrix grafted animals, and urethrography did not readily differentiate host from implant. In the heterologous matrix all tissue components were present after 6 months with no signs of rejection and even gradual improvement with time. However, regenerated smooth muscle did not equal that in normal rabbit urethra and it was not well oriented. Even after 8 months only a few disseminated smooth muscle cells were evident. Most alpha-actin positive cells were surrounding the vessels. Although function was normal, the alteration in the collagen ratio effected by matrix production indicated that the matrix collagen appeared not to have been replaced by host collagen. The increase in collagen type III may explain the lack of stricture in the grafted animals on normal retrourethrography.

Reconstruction of an elbow destroyed in gas explosion with total elbow replacement: a case report

A 25-year-old man severely injured his left elbow and lost his right hand in a gas explosion. The left forearm fracture was plated, the elbow debrided, an external fixator was applied, and the skin defect closed using local flaps and a split skin graft. Six months later the elbow was immobile due to an intra-articular fibrosis; a fully constrained hinged elbow replacement (Protetim) was implanted. Five weeks later there was a wound breakdown due to infection; the prosthesis became exposed. To salvage the limb, a latissimus dorsi myocutaneous neurovascular island flap was used to cover the soft tissue defect. Postoperative progress was uneventful and 30–100° of elbow flexion was achieved. One year later, the elbow replacement loosened without evidence of infection and it was replaced with a semiconstrained Coonrad-Morrey joint (Zimmer). In addition, the enlarged medullary canal of the humerus and ulna was packed with a morsalized homologous bone graft. One year after the revision and 3 years after the initial injury, the elbow is fully stable and pain-free with 5–120° of flexion and 40° of rotation. The patient works as a tradesman and is satisfied with the preserved function of his left hand.

HOMOLOGOUS ACELLULAR MATRIX GRAFT FOR URETHRAL RECONSTRUCTION IN THE RABBIT: HISTOLOGICAL AND FUNCTIONAL EVALUATION

To evaluate urethral replacement by a free homologous graft of acellular urethral matrix in a rabbit model. In 30 male New Zealand rabbits, a 0.8 to 1.1 cm. segment of the urethra was resected, replaced with an acellular matrix graft of 1.0 to 1.5 cm. (mean 1.3 cm.), and placed on an 8F feeding tube. Additionally 4 animals underwent sham operation. At varying intervals before sacrifice (from 10 days to 8 months), the animals underwent urodynamic evaluation and retrograde urethrography (for which 4 untreated rabbits served as control). The grafted specimens were prepared for evaluation histologically and by reverse-transcription polymerase chain reaction (RT-PCR). In all animals, the acellular matrix graft remained in its original position. Histological examination showed complete epithelialization and progressive vessel infiltration. At 3 months, smooth muscle bundles were first observed infiltrating the matrix at the end-to-end anastomosis; after 6 months, the smooth muscle bundles had grown into one-third of the matrix. Urodynamics did not detect any difference between the control and matrix-grafted animals in bladder volume, leak-point pressure and residual volume. RT-PCR detected an increase in IGF mRNA in the graft between week 3 and month 6 and in HB-EGF mRNA after day 10 through month 3. TGF-alpha mRNA was not detected; TGF-beta mRNA was unchanged from normal urethral tissue. By 8 months, the host and implant could not be differentiated by urethrography. The acellular urethral matrix allows single-stage urethral reconstruction. All tissue components were seen in the grafted matrix after 3 months, with further improvement over time; however, the smooth muscle in the matrix was less than in normal rabbit urethra and was not well oriented. RT-PCR revealed the importance of time-dependent growth factor influences during regeneration.

Treatment of bone tumors by total excision and replacement with massive autologous and homologous grafts. 1966.

Treatment of bone tumors by total excision and replacement with massive autologous and homologous grafts. 1966.

Congenital scleral staphyloma in a dog repaired with preserved homologous peritoneum

A case of congenital scleral staphyloma was treated with a preserved homologous peritoneum graft. A 2-year-old female poodle with a blue-gray mass in a dorsal and temporal position of the sclera of the left eye was evaluated. The repair of the scleral defect with a graft of preserved homologous peritoneum reduced the strabismus and the size of the staphyloma, and improved the cosmetic appearance of the eye.

Computerized tomography with CT models for contemporary ramus frame implant planning and construction.

Loss of bone in the mandible after tooth removal is associated with anatomic and aesthetic complications and instability of the mandibular complete denture. This continuing bone loss is not limited to alveolar bone; portions of the basal bone may also be resorbed. Thus, mandibular complete denture is the most unstable, unretentive, conventional prosthesis fabricated in routine dental practice. Root-form endosteal implants cannot always be placed in advanced atrophic mandibles without autogenous bone grafting (from either the iliac hip crest or another site) or bone regeneration. The ramus frame implant (RFI) is indicated when the atrophy in the mandible is advanced. An RFI is an immediate, totally implant-supported prosthesis, which can use homologous grafting material and platelet-rich plasma for increased bone regeneration. The third-generation RFI provides all of the benefits of the first- and second-generation RFIs as well as improvements provided by computed tomography and computer-aided design/stereolithography applications: planning, simplified placement, improved grafting, predictable manufactured components, and retrievability.