Reconstructive Transplantation Research Articles

Mesenchymal stem cells in craniofacial reconstruction: a comprehensive review.

Craniofacial reconstruction faces many challenges, including high complexity, strong specificity, severe injury, irregular and complex wounds, and high risk of bleeding. Traditionally, the "gold standard" for treating craniofacial bone defects has been tissue transplantation, which involves the transplantation of bone, cartilage, skin, and other tissues from other parts of the body. However, the shape of craniofacial bone and cartilage structures varies greatly and is distinctly different from ordinary long bones. Craniofacial bones originate from the neural crest, while long bones originate from the mesoderm. These factors contribute to the poor effectiveness of tissue transplantation in repairing craniofacial defects. Autologous mesenchymal stem cell transplantation exhibits excellent pluripotency, low immunogenicity, and minimally invasive properties, and is considered a potential alternative to tissue transplantation for treating craniofacial defects. Researchers have found that both craniofacial-specific mesenchymal stem cells and mesenchymal stem cells from other parts of the body have significant effects on the restoration and reconstruction of craniofacial bones, cartilage, wounds, and adipose tissue. In addition, the continuous development and application of tissue engineering technology provide new ideas for craniofacial repair. With the continuous exploration of mesenchymal stem cells by researchers and the continuous development of tissue engineering technology, the use of autologous mesenchymal stem cell transplantation for craniofacial reconstruction has gradually been accepted and promoted. This article will review the applications of various types of mesenchymal stem cells and related tissue engineering in craniofacial repair and reconstruction.

Modified mini-SLET for treatment of complex cases in pterygium surgery

The major problem associated with the benign but destructive growing pterygium is the high recurrence rate. Anew surgical technique to lower recurrence rates is minor ipsilateral simple limbal epithelial transplantation (mini-SLET), where the regeneration potential of limbal stem cells is used in combination with amniotic membrane transplantation (AMT) for surgical reconstruction. The aim of this study is to assess the surgical outcome of the mini-SLET technique with tenonectomy, mitomycinC, and AMT as used in the authors' hospital. Atotal of 16eyes from 15patients undergoing mini-SLET after surgical pterygium removal with tenonectomy, mitomycinC, and AMT were analyzed retrospectively. Two different groups of pterygia were enrolled: group1 included recurrent pterygia (n = 10) and group2 comprised primary large pterygia such as double-head pterygia (n = 6). In addition to assessment of best corrected visual acuity and compete ophthalmological examination, preoperative slip-lamp examination with photo documentation served to calculate the corneal size of the pterygium head using VISUPAC software (Zeiss, Oberkochen, Germany). Postoperatively, best corrected visual acuity and slit-lamp examination were routinely evaluated. The surgical outcome was defined by the postoperatively achieved best corrected visual acuity, restoration of the ocular surface, recurrence rate, and rate of postoperative complications. Median follow-up in all patients was 27months; in groups1 and 2 it was 30.7and 25.3months, respectively. No recurrence developed in 15eyes (93.75%). Only one group1 patient (6.25%) suffered arecurrent lesion after 10months. Postoperatively, logMAR visual acuity did not change significantly. During follow-up, complications were limited to one case of early wound dehiscence. Mini-SLET in combination with tenonectomy, mitomycinC, and AMT enables good surgical reconstruction of the ocular surface, and almost complete healing in the sense of restitutio ad integrum is possible. The results of the present study have shown the technique's effectiveness for recurrence prevention.

Current opinion: advances in machine perfusion and preservation of vascularized composite allografts - will time still matter?

A major hurdle hindering more widespread application of reconstructive transplantation is the very limited cold ischemia time (CIT) of vascularized composite allografts (VCAs). In this review, we discuss cutting edge machine perfusion protocols and preservation strategies to overcome this limitation. Several preclinical machine perfusion studies have demonstrated the multifactorial utility of this technology to extend preservation windows, assess graft viability prior to transplantation and salvage damaged tissue, yet there are currently no clinically approved machine perfusion protocols for reconstructive transplantation. Thus, machine perfusion remains an open challenge in VCA due to the complexity of the various tissue types. In addition, multiple other promising avenues to prolong preservation of composite allografts have emerged. These include cryopreservation, high subzero preservation, vitrification and nanowarming. Despite several studies demonstrating extended preservation windows, there are several limitations that must be overcome prior to clinical translation. As both machine perfusion and subzero preservation protocols have rapidly advanced in the past few years, special consideration should be given to their potential complementary utilization. Current and emerging machine perfusion and preservation technologies in VCA have great promise to transform the field of reconstructive transplantation, as every extra hour of CIT helps ease the complexities of the peri-transplant workflow. Amongst the many advantages, longer preservation windows may allow for elective procedures, improved matching, establishment of novel immunomodulatory protocols and global transport of grafts, ultimately enabling us the ability to offer this life changing procedure to more patients.

Reconstructive Transplant Investigator‐Initiated Research Award (DOD)

Reconstructive Transplant Investigator‐Initiated Research Award (DOD)

Amniotic Membrane Transplantation for Reconstruction of Ocular Surface Lesion Excisions in Pediatric Population.

To define the use of human amniotic membrane transplantation (hAMT) for reconstruction of the ocular surface after ocular surface lesion excisions in pediatric population during the last decade in a tertiary eye center. A total of 31 patients who underwent hAMT procedure because of the excision of ocular surface lesions between January 2009 and December 2021 were included in this study. The medical data were retrospectively evaluated. The female-to-male ratio was 14/17. The mean age of the patients was 10.1±4.1 (range, 1-18) years. Although a single hAMT was applied to most of the cases (94.4%; 34 eyes), more than one hAMT was applied to 5.6% of cases (2 eyes). The amniotic membrane degradation duration was found to be 21.5±10.8 (range, 13-50) days. Amniotic membrane is used as a biomaterial in various ocular surface diseases with its anti-inflammatory, antimicrobial, and wound healing properties. Although widely used, there are only a few studies reporting its clinical efficacy in the pediatric age group. It seems to be safe and effective in pediatric age group for ocular surface reconstruction after ocular surface lesion excisions.

Effectiveness of lobulated pedicled rectus abdominis myocutaneous flap for repairing huge chest wall defect

To explore the effectiveness of lobulated pedicled rectus abdominis myocutaneous flap to repair huge chest wall defect. Between June 2021 and June 2022, 14 patients with huge chest wall defects were treated with radical resection of the lesion and lobulated pedicled rectus abdominis myocutaneous flap transplantation for reconstruction of chest wall defects. The patients included 5 males and 9 females with an average age of 44.2 years (range, 32-57 years). The size of skin and soft tissue defect ranged from 20 cm×16 cm to 22 cm×22 cm. The bilateral pedicled rectus abdominis myocutaneous flaps in size of 26 cm×8 cm to 35 cm×14 cm were prepaired and cut into two skin paddles with basically equal area according to the actual defect size of the chest wall. After the lobulated pedicled rectus abdominis myocutaneous flap was transferred to the defect, there were two reshaping methods. The first method was that the skin paddle at the lower position and opposite side was unchanged, and the skin paddle at the effected side was rotated by 90° (7 cases). The second method was that the two skin paddles were rotated 90° respectively (7 cases). The donor site was sutured directly. All 14 flaps survived successfully and the wound healed by first intention. The incisions at donor site healed by first intention. All patients were followed up 6-12 months (mean, 8.7 months). The appearance and texture of the flaps were satisfactory. Only linear scar was left at the donor site, and the appearance and activity of the abdominal wall were not affected. No local recurrence was found in all tumor patients, and distant metastasis occurred in 2 breast cancer patients (1 liver metastasis and 1 lung metastasis). The lobulated pedicled rectus abdominis myocutaneous flap in repair of huge chest wall defect can ensure the safety of blood supply of the flap to the greatest extent, ensure the effective and full use of the flap tissue, and reduce postoperative complications.

The Value of Upper Extremity, face, and uterus transplantation: A Summit Conference

A panel of over 60 experts in the field of vascular composite allotransplantation from around the United States gathered on November 8, 2019 at the Uniformed Services University of the Health Sciences, in Bethesda MD. Experts in the field were recruited and invited through a collaborative effort of the American Society for Reconstructive Transplantation, the American Society of Transplantation, the American Society for Reproductive Medicine, and the American Society of Transplant Surgeons in order to discuss The Value of Upper Extremity, Face, and Uterus Transplantation: A Summit Conference . All sessions were directed by a moderator and focused on indications and contraindications, outcomes and costs of vascular composite allotransplantations in order to evaluate and discuss the state of the art science in the field. Representatives of major vascular composite allotransplantation centers in North America (Cleveland Clinic, University of Pennsylvania, Brigham and Women’s Health, New York University, the Mayo Clinic, Baylor, John Hopkins University, the University of Louisville) collaborated in order to present the combined experience of the major transplant centers in the United States. The panel members developed consensus guidelines for publication demonstrating success and unity amongst the vascular composite allotransplantation and solid organ transplantation communities. • A panel of 60 vascular composite allotransplantation experts from around the United States met in Bethesda, MD on November 8, 2019. • Indications, contraindication, outcomes and complications of face, hand and uterus transplantation were discussed. • This consensus meeting served to propel the field of vascular allograft transplantation through unity.

Aspartic acid and epidermal growth factor modified decellularized rabbit conjunctiva for conjunctival reconstruction

Conjunctival reconstruction is an indispensable part of ocular surface regeneration. Decellularized matrix has been considered as an ideal conjunctival substitution for conjunctival reconstruction. In the present study, we report the use of a decellularized rabbit conjunctiva (DRC) for conjunctival reconstruction in the rabbit surgical trauma model. Prepared by the phospholipase A2 decellularized method, the DRC was nearly DNA free while the collagen structure and natural extracellular matrix (ECM) were well preserved. In order to improve the performance of DRC, aspartic acid (Asp) was used as a spacer arm to crosslink epidermal growth factor (EGF) on the DRC to obtain DRC-Asp-EGF. The conjunctival epithelial cells cultured on the DRC-Asp-EGF showed a higher survival rates and a greater potential to differentiate into conjunctival goblet cells (CGCs) than those on the DRC. Finally, three groups were set to evaluate the transplantation effects in the rabbit surgical trauma model for 28 days: DRC-Asp-EGF group, amniotic membrane (AM) group, and ungrafted group. The DRC-Asp-EGF group was completely re-epithelized, and more CGCs were regenerated than the AM group, while no significant improvements were observed in the ungrafted group. Intact collagen structure, angiogenesis, and no scar formation were also observed in the DRC-Asp-EGF group. These results suggest that DRC-Asp-EGF is a feasible and effective transplant for conjunctival reconstruction and ocular surface regeneration.

Transcutaneous CO2 Pressure Monitoring Increases Salvage Rates after Free Tissue Transplantation for Extremity Reconstruction.

Background:Although free tissue transplantation (FTT) is an essential technique in extremity functional reconstruction, postoperative blood flow disturbance is one of the critical complications leading to transplanted tissue necrosis. Early detection of this complication may prevent tissue failure by prompt improvement of blood flow. The aim of this study was to determine whether transcutaneous carbon dioxide pressure (TcPCO2) monitoring increases the salvage rates after FTT.Methods:We retrospectively reviewed 75 consecutive patients who underwent FTT for extremity reconstruction with TcPCO2 monitoring postoperatively between December 2016 and September 2021.Results:Extremity reconstruction was performed in 53 cases due to trauma, 20 cases due to infection, and two cases due to tumor resection for tissue defects. The overall success rate of the FTT was 98.7%, with 13 complications. Of the 11 patients who underwent reoperation, nine had thrombosis and two had vascular strangulation. However, when reoperation was decided, none of the reoperation cases still exhibited any deterioration in the Doppler or clinical assessment. All reoperated cases were salvaged. Of the two patients who did not undergo reoperation, one had failed flaps and one had partial skin necrosis. With a TcPCO2 cutoff value of 70 mm Hg, the sensitivity and specificity for detecting complications due to impaired blood flow were 100% and 93.5%, respectively.Conclusions:TcPCO2 monitoring was performed after FTT for extremity reconstruction, and all cases of reoperation were salvaged. TcPCO2 monitoring can detect impaired postoperative blood flow critically earlier than clinical assessments and may increase salvage rates of transplanted tissue.

Comparison of Rapid Rehabilitation after Anterior Cruciate Ligament Reconstruction with Tensioning Technique and Traditional Rehabilitation.

To investigate the efficacy of a fast rehabilitation program for the recovery of knee joint function after arthroscopic autologous hamstring tendon transplantation for reconstruction of the anterior cruciate ligament (ACL), from January 1, 2017, to March 31, 2019, a total of 65 patients with ACL injury were randomly divided into a study group and a control group. Both groups were treated with autologous hamstring tendon to reconstruct the anterior cruciate ligament, arthroscopic transplantation, and decompression techniques. The research group was treated with a fast rehabilitation program. The control group was treated with traditional rehabilitation program. Knee flexion angles were measured at 2, 4, and 8 weeks postoperatively. KT-1000 knee anterior stability was measured at 3, 6, and 12 months after operation. Knee function was assessed by subjective knee function assessment scale (IKDC) and Lysholm knee score. The knee curvature, KT-1000 measurement, IKDC score, and Lysholm score were compared between the two groups before and after treatment. KT-1000 measured value, IKDC score, and Lysholm score in 2 groups were significantly improved 3, 6, and 12 months compared with those before treatment, and the difference was statistically significant (P < 0.001). Comparison between the two groups: 2 weeks, 4 weeks, and 8 weeks after treatment, the knee curvature in the study group was better than that in the control group, and the difference was statistically significant (P < 0.001); there was no significant difference in the measured values of KT-1000 between the two groups 3, 6, and 12 months after treatment (P > 0.05); IKDC score and Lysholm score in the study group 3 and 6 months after treatment were significantly better than those in the control group, with statistical significance (P < 0.001); there was no significant difference in IKDC score and Lysholm score between the two groups 12 months after treatment (P >0.05). Autograft hamstring tendon transplantation and tense-reducing technique for anatomical reconstruction of anterior cruciate ligament under arthroscopy combined with rapid rehabilitation program can quickly, safely, and effectively restore the knee function of patients, greatly shortening the rehabilitation period of patients.

Long-term preservation of metacarpophalangeal joint function in traumatic defects by metatarsophalangeal osteochondral transplantation.

The integrity of the metacarpophalangeal (MCP) joints is essential for finger and hand function. Preservation of range-of-motion is one of the aims in reconstruction of complex injuries to these joints. Osteochondral transplants have shown to be reliable in reconstruction of various joint defects. This series presents three patients with traumatic injuries to four MCP joints, which were reconstructed by seven avascular osteochondral transplants of metatarsophalangeal (MTP) joints. The joints were examined for radiographic signs of resorption or joint space narrowing, and if this would affect the joints' function in the long term. In three patients (40, 45 and 48years) with complex injuries to their MCP joints (one milling, two saw injuries), four joints were reconstructed by three metatarsal head and four osteochondral transplants of the base of the proximal toe phalanges. Beside the joint itself, various soft tissue defects were reconstructed in each patient. The patients were clinically and radiographically examined after 9, 6, respectively, 7years. All patients were satisfied with the result without any pain in the MCP joints. Range-of-motion in the four affected joints rated 25, 60, 75, and 80°, DASH scores rated 13, 29, and 17, respectively. None of the patients complained of problems at their feet. Radiographic examination revealed moderate joint space narrowing in one of the four joints. In another patient, localized osteolysis was found around the screws' heads, so that the screws were removed 7years post-op. Osteochondral transplants for reconstruction of MCP defects are able to preserve function in severely injured joints even in the long term. Joint space narrowing may occur, which is not accompanied by pain, however. Since localized osteolysis can cause screw head prominence, mid-term radiographic follow-up is necessary to prevent damage to the joint. In the long term, remaining bone stock may be adequate for total joint replacement.

The Chauvet Workgroup: A Resource for the Psychosocial Aspects of Reconstructive Transplantation

From the first successful hand transplant that ushered in the era of reconstructive transplantation or vascularized composite allotransplantation (VCA), it was apparent that the psychosocial background of the patients and the psychological impact of these visible grafts were of extreme importance to their successful outcome. The outcome that is expected from these grafts includes improving patients’ functional abilities, quality of life, and psychological well-being.1 Notably, the visible and functional nature of most VCA grafts, such as hand, face, or penis, makes the experience of transplantation uniquely different from that of solid organ transplantation.

CBCT Evaluation of the maxillary palatine process as a donor site for the regeneration of periodontal defects.

Background The maxillary palatine process (MPP) is an excellent source of autogenous bone transplants for anterior maxillary reconstruction. This research aimed to determine the quantity and quality of accessible MPP as a donor location. Methods Cone-beam computed tomography (CBCT) scans of patients referred to the School of Dentistry were evaluated by a certified examiner. The harvestable MPP was defined as the space between the distal surfaces of maxillary first premolars. OnDemand 3D Imaging software was used to determine bone properties. SPSS software was used to investigate the following variables: Bone characteristics are correlated with age and gender, accessible volume, and palatal width and height. P<0.05 was defined as the level of statistical significance. Results This study was performed on CBCT scans of 81 subjects (41 females and 40 males). MPP volume and palatal heights were 1.33±0.53 cm3 and 20.86±5.51 mm, respectively. Maximum bone density was observed around lateral incisors. Palatal width was 33.81±2.42 mm between canines and 41.81±2.66 mm between premolars. The MPP volume was significantly greater in males (P<0.001). Additionally, there was a positive correlation between the volume and palatal width (P<0.05).Conclusion Within the constraints of this research, there is a limited supply of MMP accessible for use as a graft source, and it is best suited for treating localized bone lesions. The favorable link between palatal breadth and harvestable volume aids the surgeon in estimating the quantity of bone accessible during the first evaluation.

A Reliable Porcine Fascio-Cutaneous Flap Model for Vascularized Composite Allografts Bioengineering Studies.

Vascularized Composite Allografts (VCA) such as hand, face, or penile transplant represents the cutting-edge treatment for devastating skin defects, failed by the first steps of the reconstructive ladder. Despite promising aesthetic and functional outcomes, the main limiting factor remains the need for a drastically applied lifelong immunosuppression and its well-known medical risks, preventing broader indications. Therefore, lifting the immune barrier in VCA is essential to tip the ethical scale and improve patients' quality of life using the most advanced surgical techniques. De novo creation of a patient-specific graft is the upcoming breakthrough in reconstructive transplantation. Using tissue engineering techniques, VCAs can be freed of donor cells and customized for the recipient through perfusion-decellularization-recellularization. To develop these new technologies, a large-scale animal VCA model is necessary. Hence, swine fascio-cutaneous flaps, composed of skin, fat, fascia, and vessels, represent an ideal model for preliminary studies in VCA. Nevertheless, most VCA models described in the literature include muscle and bone. This work reportsa reliable and reproducible technique for saphenous fascio-cutaneous flap harvest in swine, a practical tool for various research fields, especially vascularized composite tissue engineering.

Induction of Corneal Epithelial Differentiation of Induced Pluripotent and Orbital Fat-Derived Stem Cells Seeded on Decellularized Human Corneas.

Up to 40% of donor corneas are deemed unsuitable for transplantation, aggravating the shortage of graft tissue. In most cases, the corneal extracellular matrix is intact. Therefore, their decellularization followed by repopulation with autologous cells may constitute an efficient alternative to reduce the amount of discarded tissue and the risk of immune rejection after transplantation. Although induced pluripotent (hiPSCs) and orbital fat-derived stem cells (OFSCs) hold great promise for corneal epithelial (CE) reconstruction, no study to date has evaluated the capacity of decellularized corneas (DCs) to support the attachment and differentiation of these cells into CE-like cells. Here, we recellularize DCs with hiPSCs and OFSCs and evaluate their differentiation potential into CE-like cells using animal serum-free culture conditions. Cell viability and adhesion on DCs were assessed by calcein-AM staining and scanning electron microscopy. Cell differentiation was evaluated by RT-qPCR and immunofluorescence analyses. DCs successfully supported the adhesion and survival of hiPSCs and OFSCs. The OFSCs cultured under differentiation conditions could not express the CE markers, TP63, KRT3, PAX6, and KRT12, while the hiPSCs gave rise to cells expressing high levels of these markers. RT-qPCR data suggested that the DCs provided an inductive environment for CE differentiation of hiPSCs, supporting the expression of PAX6 and KRT12 without the need for any soluble induction factors. Our results open the avenue for future studies regarding the in vivo effects of DCs as carriers for autologous cell transplantation for ocular surface reconstruction.

Результаты аутотрансплантации второго пальца стопы в позицию утраченного первого пальца кисти

Defects of the thumb negatively impact physical and mental health, lead to depression, inferiority complex and hopelessness in the future. The aim of the study was to explore long-term results of thumb reconstruction using autologous transplantation of the second toe with microvascular anastomoses. Material and methods Second toe transplantation for thumb reconstruction was performed for 54 patients. There were 48 male and 6 female patients aged from 12 to 55 years. When analyzing the long-term results of surgical treatment of patients. The anatomy and functionality of the repaired finger was evaluated at a long term measuring the range of motion in the joints, muscle strength of the hand and major types of hand grips. Results The autograft completely healed with opposition of the reconstructed thumb and the rest fingers restored in 51 patients. The autograft failed in three cases treated with less functional methods. Conclusion Microsurgical reconstruction technologies used for a lost thumb facilitated rapid recovery of the finger and significantly improved functions of the injured hand as an entity. Free second toe transplantation using microvascular anastomoses for the thumb reconstruction allowed the patient regain basic gripping functions and improve cosmesis of the injured hand.

Surgical treatment of extensive symblepharon with oral mucosa autografting transplantation in two patients with ocular cicatricial pemphigoid

AbstractPurposeTο present the surgical management of extensive symblepharon in two cases of advanced ocular cicatricial pemphigoid.MethodsA 68‐year‐old male with ocular cicatricial pemphigoid treated with methotrexate was presenting trichiasis and extensive symblepharon in the left lower eyelid. The second case was a 70‐year‐old woman treated with dapsone and mycophenolate mofetil with extensive symblepharon in her left lower eyelid. In both cases, we harvested oral mucosa autograft and sutured it in the left lower tarsus after surgical dissection of the symblepharon.ResultsIn both cases postoperatively the lower eyelid was mobile, the graft was in place and vivid, no signs of inflammation nor rejection, quiet eye. Three months later there was no scarring of the graft and fornix in the first patient, but some scarring in the second patient as the control of ocular cicatricial pemphigoid was inadequate.ConclusionsOral mucosa autografting transplantation for forniceal reconstruction is a surgical technique that should be considered in patients with symblepharon formation and ocular cicatricial pemphigoid when active disease is controlled.BibliographyKheirkhah A, Blanco G, Casas V, Hayashida Y, Raju VK, Tseng SC. Surgical strategies for fornix reconstruction based on symblepharon severity. Am J Ophthalmol. 2008 Aug;146(2):266‐275. doi: 10.1016/j.ajo.2008.03.028. Epub 2008 Jun 2. PMID: 18514608.

Effect of free deep inferior epigastric artery perforator flap transplantation in breast shaping of two-staged breast reconstruction with vertical scar

To summarize the difficulties and key points of free deep inferior epigastric artery perforator flap (DIEP) transplantation in breast shaping of two-staged breast reconstruction with vertical scar. The clinical data of 32 postoperative breast cancer patients after mastectomy who underwent free DIEP transplantation for breast reconstruction between October 2015 and October 2019, whose original surgical incisions were all vertical and longitudinal, were retrospectively analysed. All the patients were female, aged from 31 to 42 years, with an average of 34.6 years. The disease duration of breast cancer ranged from 9 to 48 months (mean, 22.8 months). Free DIEP pedicled with contralateral vessels were used in all cases, and the recipient vessels were intrathoracic vessels. Among them, 17 flaps were placed longitudinally, 15 flaps were placed obliquely; Z-shaped flaps were used in 18 cases to adjust the chest wall skin contracture, and contralateral breast reduction and mastopexy were accomplished at the same time in 23 cases. All DIEP survived completely, and all donor and recipient sites healed by first intention. Internal thoracic lymph node metastasis was found in 1 case and treated with radiotherapy. All 32 cases were followed up 9-48 months, with an average of 19.4 months. The appearance and texture of all flaps were satisfactory, and only linear scar was left in donor site. Eleven patients underwent further autologous fat transplantation and nipple reconstruction. All patients had no effect on abdominal wall activity, and no local recurrence and metastasis was found. It is difficult to use free DIEP for two-staged breast reconstruction in patients received mastectomy with vertical longitudinal scar left. Combined with different breast shaping techniques, the outcomes can significantly improve.

Reconstructive Transplant Investigator‐Initiated Research Award (DOD)

Federal Grants & ContractsVolume 45, Issue 18 p. 4-4 Grants alerts Reconstructive Transplant Investigator-Initiated Research Award (DOD) First published: 16 August 2021 https://doi.org/10.1002/fgc.31894Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume45, Issue1819 August 2021Pages 4-4 RelatedInformation

Sensitization and Desensitization in Vascularized Composite Allotransplantation.

Vascularized composite allotransplantation (VCA) is a field under research and has emerged as an alternative option for the repair of severe disfiguring defects that result from severe tissue loss in a selected group of patients. Lifelong immunosuppressive therapy, immunosuppression associated complications, and the effects of the host immune response in the graft are major concerns in this type of quality-of-life transplant. The initial management of extensive soft tissue injury can lead to the development of anti-HLA antibodies through injury-related factors, transfusion and cadaveric grafting. The role of antibody-mediated rejection, donor-specific antibody (DSA) formation and graft rejection in the context of VCA still remain poorly understood. The most common antigenic target of preexisting alloantibodies are MHC mismatches, though recognition of ABO incompatible antigens, minor histocompatibility complexes and endothelial cells has also been shown to contribute to rejection. Mechanistically, alloantibody-mediated tissue damage occurs primarily through complement fixation as well as through antibody-dependent cellular toxicity. If DSA exist, activation of complement and coagulation cascades can result in vascular thrombosis and infarction and thus rejection and graft loss. Both preexisting DSA but especially de-novo DSA are currently considered as main contributors to late allograft injury and graft failure. Desensitization protocols are currently being developed for VCA, mainly including removal of alloantibodies whereas treatment of established antibody-mediated rejection is achieved through high dose intravenous immunoglobulins. The long-term efficacy of such therapies in sensitized VCA recipients is currently unknown. The current evidence base for sensitizing events and outcomes in reconstructive transplantation is limited. However, current data show that VCA transplantation has been performed in the setting of HLA-sensitization.