Grafts For Reconstructive Surgery Research Articles

Biomechanical and Histological Study of Retrieved LARS Synthetic Ligaments.

Synthetic grafts have been used for a number of years in anterior cruciate ligament (ACL) reconstruction surgery. One of the more recent additions to the stable of synthetic ligaments is the Ligament Augmentation and Reconstruction System (LARS) ligament. To analyze the biomechanics and histology of LARS grafts retrieved due to failure of the device. Descriptive laboratory study. A total of 22 LARS ligament grafts that were explanted from patients were sent for analysis. Five new, unused samples of the standard LARS ACL graft were also analyzed. Biomechanical testing was performed: ultimate tensile force, force versus displacement, and stress versus strain were recorded. Histopathological examination was performed looking for degree of fibrous tissue ingrowth as well as the presence of a foreign body reaction. Of the 22 grafts retrieved, 14 were used for ACL grafts, 1 for a lateral collateral ligament graft, 2 for medial collateral ligament grafts, 4 for gluteal tendon augmentation, and 1 for a supraspinatus augmentation. A severe foreign body reaction was found in 86% of the grafts (18/22) and a mild foreign body reaction in the remaining 14% (4/22). Tissue ingrowth was minimal in the majority of ACL grafts; the other grafts showed moderate tissue ingrowth. Maximal tensile force was significantly higher for the new ACL grafts (mean ± SD, 1667 ± 845 N) compared with the retrieved grafts (897 ± 395 N; P < .05). This study demonstrated that the vast majority of retrieved LARS artificial ligaments had a florid foreign body reaction. There was minimal tissue ingrowth in ACL grafts and moderate ingrowth in other grafts. Retrieved grafts had a decreased ultimate tensile force, which increased their risk of rupture. Surgeons should be cautious in choosing to use these grafts in reconstructive surgery for patients.

Analysis of cognitive framework and biomedical translation of tissue engineering in otolaryngology

Tissue engineering is a relatively recent research area aimed at developing artificial tissues that can restore, maintain, or even improve the anatomical and/or functional integrity of injured tissues. Otolaryngology, as a leading surgical specialty in head and neck surgery, is a candidate for the use of these advanced therapies and medicinal products developed. Nevertheless, a knowledge-based analysis of both areas together is still needed. The dataset was retrieved from the Web of Science database from 1900 to 2020. SciMAT software was used to perform the science mapping analysis and the data for the biomedical translation identification was obtained from the iCite platform. Regarding the analysis of the cognitive structure, we find consolidated research lines, such as the generation of cartilage for use as a graft in reconstructive surgery, reconstruction of microtia, or the closure of perforations of the tympanic membrane. This last research area occupies the most relevant clinical translation with the rest of the areas presenting a lower translational level. In conclusion, Tissue engineering is still in an early translational stage in otolaryngology, otology being the field where most advances have been achieved. Therefore, although otolaryngologists should play an active role in translational research in tissue engineering, greater multidisciplinary efforts are required to promote and encourage the translation of potential clinical applications of tissue engineering for routine clinical use.

Comparison between the Different Types of Tendon Grafts in Reconstructive Surgery

Tendon grafts play a crucial role in reconstructive surgery, restoring function and stability to damaged tendons. This literature review examines the theoretical framework, surgical treatment, and potential complications associated with different types of tendon grafts. Autografts, harvested from the patient's own body, are considered the gold standard due to their biocompatibility and better integration. Allografts and synthetic grafts offer alternatives, eliminating donor site morbidity and providing consistent biomechanical properties. However, considerations include the risk of graft rejection and inferior mechanical performance. The selection of the most suitable graft should be tailored to individual patient needs, optimizing functional outcomes and patient satisfaction. Advances in graft technology continue to shape the landscape of reconstructive surgery, further enhancing patient outcomes and quality of life.

Buccal Mucosal Ureteroplasty for the Management of Ureteral Strictures: Patient Selection and Considerations.

The landscape for upper genitourinary tract reconstruction continues to evolve with innovations in technology and surgical techniques. While the use of flaps and grafts in reconstructive surgery is not a novel concept, the application of buccal mucosal grafts in ureteral reconstruction has only been described over the last 20 years and is now an important adjunct for approaching ureteral strictures. Alongside the increasing use of robotics in urologic surgery, the options available for reconstruction of the upper tract with decreasing patient morbidity are multiplying. Herein, we aim to highlight various patient characteristics which may favor the use of buccal mucosa for addressing ureteral strictures.

Surgical Free Flaps and Grafts in Head and Neck Reconstruction

This review article discusses the basic principles behind the use of flaps and grafts for reconstructive surgery in the head and neck, with a special emphasis on the types of commonly used free flaps, their imaging appearance as well as some frequently encountered postoperative complications. Given the ubiquity and complexity of these reconstructive techniques, it is essential that head and neck radiologists be familiar in distinguishing between the expected evolving findings, complications, and tumor recurrence.

Anatomical and Computed Tomographic Study of the Eighth and Ninth Costochondral Junctions Used as a Graft in Reconstructive Surgery

Autologous costochondral junctions have been used for decades as a source for osseo-cartilaginous grafts used in reconstructive surgery.In this study, cadaveric dissection is combined with CT imaging to identify the location of the 8th and 9th costochondral junctions and their relation to the surrounding anatomical landmarks and to provide topographic guidance for its harvesting as a graft and to minimize complications of the harvesting procedure.The aim of this study is to describe the anatomy of the 8th and 9th costochondral junctions and its relation to the surrounding anatomical landmarks by cadaveric dissection and computed tomography imagingCadavers: Twelve preserved human cadavers (Eight males and four females) obtained from the morgue of the Anatomy Department, Faculty of Medicine, Alexandria University.Radiological Images: Fifty retrospective thoracic Computed tomography images of living humans (Twenty-five males and twenty-five females) obtained from the database of the Radiology Department of Alexandria Main University Hospital.

Сосудистые трансплантаты в реконструктивной хирургии магистральных вен.

Сосудистые трансплантаты в реконструктивной хирургии магистральных вен.

Osseous Flap of Galea and Periosteum Filled With Mesenchymal Stem Cells, Platelet-Rich Plasma, Bone Dust, and Hyaluronic Acid.

Reconstructive surgery to craniofacial deformities caused by tumor ressections, traumas or congenital malformation are frequent in medicine practice. It aims to provide the patients with better quality of life and functional improvement of speech, breathing, chewing, and swallowing. Many are the techniques described in the literature to recover bone defects. This study evaluated a vascularized galeal and periosteum flap in rabbits, which could possibly substitute the bone graft in reconstructive surgery, especially for facial defects. It involved rabbits, divided into 12 groups, submitted to a surgical procedure to construct the galea and periosteum cranial flap filled with fragments of cranial bone, platelet-rich plasma, mesenchimal stem cells, and hyaluronic acid. The evaluation methods included image examinations and histological analysis.The results demonstrated bone formation with the use of platelet-rich plasma, mesenchimal stem cells, and bone fragments. The use of several enrichment materials of osseous cellular stimulation improved the quality and bone tissue organization. The more enrichment factor used, the better the tissue quality result was.Much research should be done to improve the methods and to analyze if results in human have the same bone formation as it happened in rabbits.

The use of grafts in reconstructive surgery of the retrotympanic area of the middle ear

The issues of surgical treatment and rehabilitation of the patients suffering from chronic suppurative otitis media (CSOM) belong to the most urgent problems in the present-day otiatrics. The latter is related to the significant number of unsatisfactory results in both sanitizing and reconstructive-functional interventions. Currently, most otosurgeons hold the opinion that alongside with sanation, it is necessary to restore the middle ear architectonics, thereby eliminating the conditions predisposing to inflammations. Reconstructive surgery of the middle ear retrotympanic regions is of high importance for solving this task.

A New Era of Diced Cartilage Rhinoplasty: Our Experience.

The use of diced cartilage grafts in reconstructive surgery was first described by Peer in 1943 though it was not for rhinoplasty. A number of studies describing diced cartilage have followed since then, but the technique has never achieved widespread use. In recent years, however, an interest in using diced cartilage for augmentation rhinoplasty has resurfaced. As surgeons revisit this technique, it is important that this technique is subjected to critical evaluation in terms of materials, approaches, and indications of using using diced-cartilage augmentation. External rhinoplasty approach with diced cartilage as a graft was used to for augmenting the nasal dorsumin 32 patients. Cosmetic appearance improved in all cases both subjectively and objectively. Only one patient showed constriction of dorsum 09months after surgery. None of the patient had any intra-operative complication, 02 had donor site complication in the form of aural haematoma in 01 patient and wound infection in 01 patient. Diced cartilage technique is an attractive option for use in rhinoplasties especially those requiring augmentation procedures.

Diced Cartilage Versus Solid Grafts in Rhinoplasty

The use of diced cartilage grafts in reconstructive surgery was first described by Peer [1] in 1943. A number of additional reports describing diced cartilage have followed since then, but the technique has never achieved widespread use. In recent years, however, an interest in using diced cartilage for rhinoplasty procedures has resurfaced. As aesthetic and reconstructive surgeons revisit this technique, it is important that we critically assess the various materials, approaches, and indications applied by clinicians using diced-cartilage augmentation. The use of diced cartilage rather than a solid piece of cartilage graft is an attractive concept because it offers greater flexibility, carries a minimal risk of warping, and obviates the need for a long and straight cartilage graft donor site. Diced cartilage also may be particularly advantageous by enabling the use of residual septum in cases of secondary and revision rhinoplasty or by proving to be a more effective method for delivering conchal cartilage that as a single piece may be inadequate. To prevent problems of palpability and visibility of diced grafts, surgeons have described the use of autogenous, synthetic, or alloplastic wraps to camouflage the cartilage construct. A great deal of controversy currently exists about the various techniques that have been advocated, and the optimal substance or scaffold for delivering diced cartilage has yet to be determined. In 2000, Erol [2] introduced the concept of a ‘‘Turkish Delight,’’ whereby diced cartilage wrapped in Surgicel was used as an adjunct to rhinoplasty. The report by Erol describes the use of Surgicel-wrapped diced cartilage in more than 2,000 rhinoplasty cases, with successful longterm follow-up evaluation. On the other hand, others have had far less success using this approach during rhinoplasty. Daniel and Calvert [3] reported their experience using Surgicel-wrapped diced cartilage for 22 patients involving 14 radix grafts, 4 upper dorsum grafts, and 4 full-length grafts. In all cases, this technique failed to correct the problem due to complete resorption by about 3 months. As a result, Daniel and Calvert abandoned Surgicel and instead used fascia to wrap diced cartilage. In contrast, this patient cohort of fascia-wrapped diced cartilage (n = 20) did not demonstrate any notable resorption but rather required removal of excess amounts of cartilage in one-third of patients due to overcorrection for anticipated volume loss. A recent follow-up article of 79 patients with diced cartilage and fascia demonstrated adequate results at 1to 2-year follow-up evaluations [4]. In this article titled A Novel Autologous Scaffold for Diced Cartilage Grafts in Dorsal Augmentation Rhinoplasty, Bullocks et al. present an innovative approach to rhinoplasty using diced cartilage combined with autologous tissue glue (ATG: platelet-rich plasma ? fibrin glue). The authors report the use of ATG-diced cartilage constructs for 68 rhinoplasty patients requiring dorsal augmentation. During a mean follow-up period of 15 months, no major complications (extrusion, displacement, or infections) were reported, but 11 patients did experience an erythematous reaction lasting 1–4 weeks. The authors report maintenance of dorsal height in all cases, but this was not objectively studied. We believe Bullocks et al. should be congratulated for their work. If diced cartilage is a preferred method of reconstruction, these authors have introduced a novel technique for delivering diced cartilage that may minimize negative factors (i.e., elevated costs, additional donor sites, N. Tabbal (&) O. M. Tepper 521 Park Avenue, New York, NY 10065-8140, USA e-mail: mail@tabbal.us

Clinical implications of the biology of grafts: conclusions of the 2005 IUGA Grafts Roundtable

With few exceptions, the current expansion of graft utilization in pelvic reconstructive surgery is not a product of evidence-based medicine. Abdominal sacrocolpopexy and suburethral sling procedures are two situations under which synthetic graft utilization is indicated, based on randomized prospective trials and reported clinical outcomes. Otherwise, indications and contraindications for graft utilization are unclear. Current published data on the biology of synthetic and biologic grafts are limited and overall not very helpful to the reconstructive surgeon who is faced with the selection of a graft for use during a reconstructive procedure. This Roundtable presented the opportunity for a series of basic science researchers to present their data to a group of reconstructive surgeons and provide publishable background information on the various currently available grafts. The occurrence of healing abnormalities after graft implantation is becoming increasingly recognized as a potentially serious problem. To date, definitions and a classification system for healing abnormalities do not exist. Based on the input from basic scientists and experienced surgeons, a simple classification is suggested based on the site of healing abnormality, timing relative to graft implantation, presence of inflammatory changes, and the viscera into which the graft is exposed. Many opportunities for clinical and basic science research exist. As the use of grafts in reconstructive surgery is expanded, surgeons are encouraged to familiarize themselves with currently published data, and determine whether a graft should, or should not be, utilized during a reconstructive procedure, and if so, the type of graft best indicated in each specific clinical situation.

Vergleich der Genexpressionsmuster humaner Chondrozyten und chondrogen differenzierter mesenchymaler Stammzellen für das Tissue-Engineering

Tissue engineering is a promising method for the generation of chondrogenic grafts for reconstructive surgery. In cultured chondrocytes, the dedifferentiation of cells seems unavoidable for multiplication. In this study, we investigated the expression of distinct markers during the dedifferentiation of human chondrocytes (HC) harvested during septoplasty and human mesenchymal stem cells (hMSC) from cartilage biopsies in cell culture using the microarray technique. The genes for collagen 1alpha1, 2alpha1, 3alpha1, 4alpha1, 11alpha1, biglycan, fibromodulin and lumican were activated during the dedifferentiation of the HCs, collagen 9alpha2, 9alpha3, 10alpha1 and chondroadherin were inactivated. During chondrogenic differentiation of hMSCs, the genes for collagen 3alpha1, 9alpha2, 9alpha3, 10alpha1, 11alpha1 were activated, collagen 4alpha1 and fibromodulin inactivated and the genes for Col 1alpha1, biglycan und chondroadherin constantly expressed. The genetic profile for the investigated markers in human chondrocytes generated from hMSCs resembles the profile in differentiated chondrocytes. Collagen 2alpha1, 9alpha2, 9alpha3, 10alpha1 could represent markers for the differentiation of chondrocytes, Col 1alpha1, 3alpha1 und 4alpha1, biglycan, fibromodulin and lumican markers for the dedifferentiation into a more fibroblastoid cell type.

Human chondrocytes differentially express matrix modulators during in vitro expansion for tissue engineering.

Cartilage tissue engineering plays an important role in the generation of grafts for reconstructive surgery. In cultured chondrocytes, the dedifferentiation of cells seems unavoidable for multiplication. Dedifferentiated cells produce matrix of less quality, and the molecular basis is still not well understood. Therefore, the aim of our study was to investigate the expression of matrix modulators in human chondrocytes during expansion. Human chondrocytes were isolated from septal cartilage (n=32) and held in primary cell culture. Cells were harvested after 1, 6 and 21 days. The differentiation of cells using light microscopy, the expression patterns of various proteins (MMPs, BMPs, and TIMPs) using immunohistochemistry, and the expression of distinct genes using microarray technique, were investigated. The chondrocytes showed strong in vitro proliferation. After 6 and 21 days, BMP-5 and -8 were up-regulated, BMP-2 was down-regulated and BMP-6 was inactivated. Other BMPs were not expressed. The expression of MMP-2, -3 and -13 was up-regulated from day 1 to 21, and MMP-12 and -20 were down-regulated. Other MMPs were not expressed. TIMP-1 was up-regulated and TIMP-3 was down-regulated during expansion. Differential expression of matrix modulators might influence the matrix composition of engineered cartilage. Improving the basic knowledge in this area may ultimately help clinicians to identify and proactively intervene in an attempt to prevent bioartificial cartilage from losing stability.

Tissue engineering with chondrocytes and function of the extracellular matrix (Review)

Tissue engineering represents a promising method for the construction of autologous chondrogenic grafts for reconstructive surgery. The destruction or malformation of organs such as nasal cartilage, pinna and trachea in otorhinology-head and neck surgery can be caused by both: primary disease or treatment modalities. A large part of modern medical practice is aimed to repair, replace, maintain or enhance the function of damaged or diseased tissues and organs. Replacement or repair is by either artificial implants or transplantation of tissues. Such interventions are hindered by factors such as rejection by the immune system, limited blood supply or morbidity of the donor site. Reconstruction of an injured face using plastic surgery is a prime example of when the limitations of materials, science and reconstructive techniques become apparent. This review aims to briefly outline the use of chondrocytes for tissue engineering with special regard to the function of the extracellular matrix for the signalling between the chondrocytes.

Mesenchymal stem cells--a new pathway for tissue engineering in reconstructive surgery

Mesenchymal stem cells (MSC) have the capacity to differentiate into chondrocytes with the synthesis of cartilage. This report presents the use of human adult bone marrow derived mesenchymal stem cells for tissue engineering of autologous cartilage grafts. Human bone marrow aspirates were obtained from the iliac crest and fractionated on a Percoll gradient. The isolated hMSC were plated at 20 x 10 (6) cells per 100 mm (2) culture dish. After 21 days in culture at 37 degrees C with 5 % CO 2, the adherent multiplied MSC were trypsinized, counted, and tested for viability by trypan blue assay. The hMSCs were loaded into a sterile 15 ml polypropylene tube (0.5 Mio cells/ml) and centrifuged on the bottom of the tube at 500 g for 5 minutes. The MSC were cultivated for 3 weeks in vitro in a specific chondrogenetic medium composed of Dulbecco's Modified Eagles Medium-High Glucose supplemented with 10 ng/ml transforming growth factor-beta 1, 1 % ITS-Premix medium, 80 micro M ascorbic acid, and 100 nM dexamethasone. Histological and immunohistochemical studies performed after 3 weeks in three dimensional culture demonstrated the expression of cartilage specific collagen type II and X as well as proteoglycans. Human adult mesenchymal stem cells derived from bone marrow aspirates have the ability to differentiate into chondrocytes under specific culture conditions by growth factors. The use of adult mesenchymal stem cells may be a promising tool for tissue engineering of autologous cartilage grafts in reconstructive surgery in the future.

INTERPOSITION OF SURAL NERVE RESTORES FUNCTION OF CAVERNOUS NERVES RESECTED DURING RADICAL PROSTATECTOMY

Purpose The permanent loss of erectile function when both neurovascular bundles are widely resected at radical prostatectomy as well as the successful use of autologous nerve grafts in reconstructive surgery led us to perform bilateral nerve grafts in an effort to restore erectile function in potent patients treated for prostate cancer who underwent radical retropubic prostatectomy and resection of both neurovascular bundles. Materials and Methods Radical retropubic prostatectomy with deliberate resection of both neurovascular bundles was recommended for high grade, locally extensive prostate cancer in 9 select, sexually active men who reported normal erectile function. After the prostate was removed but before vesicourethral anastomosis an autologous sural nerve graft was interposed between the divided ends of the cavernous nerves bilaterally. Erectile function was monitored by patient interview, questionnaire and nocturnal penile tumescence testing after the operation. Results Four to 5 months postoperatively patients noticed slowly improving spontaneous erections, as manifested by mild tumescence regularly every several hours. Nocturnal penile tumescence testing with the RigiScan * * UroHealth Systems, Inc., Laguna Niguel, California. device at 4 to 6 months in 2 cases revealed erections that approached minimal criteria for normalcy. Approximately 14 months after surgery a rigid erection sufficient for penetration and intercourse developed in 1 patient. He described this event as “an erection of substance-hard, not just fluffy.” Conclusions We have developed a technique using sural nerve grafts to restore continuity of the cavernous nerves, which are resected during radical prostatectomy. The early return of spontaneous partial erections in our patients suggests that interposition nerve grafts may enhance the recovery of erectile function when the neurovascular bundles are resected.

Interrelationship between size and tissue-separating potential of costochondral transplants

The aim was to determine whether the reportedly unpredictable outcome of the use of costochondral grafts in reconstructive surgery is related to variation in growth potential between the transplanted cartilages. A rib fragment including the costochondral junction was transplanted across the interparietal suture in 10-day-old rats. The transplants contained either a short, intermediate, or long cartilaginous end and a constant length of bone. The animals were killed 25 days later and the width of the neurocranium was measured from dry skulls. The neurocranium was wider the longer the cartilaginous end of the transplant. It is concluded that costochondral transplants have an intrinsic potential for separating skeletal components and that this capacity is closely related to the amount of cartilage in the transplant.

The effect of prolonged ischemia time on osteocyte and osteoblast survival in composite bone grafts revascularized by microvascular anastomoses.

Twenty-six adult mongrel dogs were used to investigate the effect of prolonged ischemia on osteocyte and osteoblast survival in composite bone grafts revascularized by microvascular anastomoses. The bone grafts were stored in chilled (+5 degrees C) Collins-Terasaki solution, and ischemia time varied from 90 minutes to 48 hours. With histologic techniques and fluorochrome bone labeling it was shown that the bone marrow, the osteocytes, and the osteoblasts could completely survive up to 25 hours of ischemia. Although bone grafting techniques are employed routinely in many orthopedic and plastic surgical procedures, our knowledge is incomplete concerning the ischemic period tolerated by osteocytes and osteoblasts in these grafts. This information is essential when bone transfer on microvascular pedicles is employed, since 3 to 6 hours of ischemia time may be necessary in these operations. The present experiment has shown that osteocytes and osteoblasts can survive a rather long ischemic period if the medullary nutrient blood supply is later reconstituted. This fact adds validity to the technique of free vascularized bone grafts in reconstructive surgery.

Development and utilization of a composite island flap employing omentum: experimental investigation.

In 39 pigs, four varieties of secondary island flaps were created using omentum as a carrier. This study demonstrates that: 1. Skin grafts (split- or full-thickness), when grafted to omentum, can be transformed into an "island flap," and the free transfer of this flap with microvascular anastomosis is feasible. 2. A skin flap, a combined skin flap, or both and subjacent muscle could be vascularized with omentum to obtain an omental island skin flap or an omental island musculocutaneous flap and transferred as already described. 3. Three varieties of secondary island osteocutaneous flaps were created using the omentum. Of these flaps, eight successfully underwent microvascular transfer. Bone vascularity and incontinuity viability were demonstrated by employing a variety of standard diagnostic techniques, including 99mTc-pyrophosphate tetracycline labeling, microangiography, and histologic sectioning. In addition to the many recognized advantages of a free living bone graft in reconstructive surgery, other benefits of this new kind of island composite flap include its unlimited size, minimal donor deformity, and ease of transfer. We have demonstrated that omentum can be used to vascularize skin, a skin flap, and either tibial, costal, or iliac bone graft to obtain a secondary island flap. The clinical uses of these flaps promise a new and exciting horizon in reconstructive surgery.