Radiation therapy attenuates lymphatic vessel repair by reducing VEGFR-3 signalling.

Introduction: Surgery and radiotherapy are key cancer treatments and the leading causes of damage to the lymphatics, a vascular network critical to fluid homeostasis and immunity. The clinical manifestation of this damage constitutes a devastating side-effect of cancer treatment, known as lymphoedema. Lymphoedema is a chronic condition evolving from the accumulation of interstitial fluid due to impaired drainage via the lymphatics and is recognised to contribute significant morbidity to patients who survive their cancer. Nevertheless, the molecular mechanisms underlying the damage inflicted on lymphatic vessels, and particularly the lymphatic endothelial cells (LEC) that constitute them, by these treatment modalities, remain poorly understood. Methods: We used a combination of cell based assays, biochemistry and animal models of lymphatic injury to examine the molecular mechanisms behind LEC injury and the subsequent effects on lymphatic vessels, particularly the role of the VEGF-C/VEGF-D/VEGFR-3 lymphangiogenic signalling pathway, in lymphatic injury underpinning the development of lymphoedema. Results: We demonstrate that radiotherapy selectively impairs key LEC functions needed for new lymphatic vessel growth (lymphangiogenesis). This effect is mediated by attenuation of VEGFR-3 signalling and downstream signalling cascades. VEGFR-3 protein levels were downregulated in LEC that were exposed to radiation, and LEC were therefore selectively less responsive to VEGF-C and VEGF-D. These findings were validated in our animal models of radiation and surgical injury. Discussion: Our data provide mechanistic insight into injury sustained by LEC and lymphatics during surgical and radiotherapy cancer treatments and underscore the need for alternative non-VEGF-C/VEGFR-3-based therapies to treat lymphoedema.

Resurfacing of a Degloved Finger With a Reverse Radial Adipofascial Forearm Flap.

Complex upper-limb trauma, in particular crush and avulsion injuries, present an ongoing challenge for the reconstructive hand surgeon given the extensive zone of injury, particularly involving the neurovascular structures. When replantation is deemed unsuitable, the reconstruction must be both robust and flexible enough to meet the functional needs of the patient. The authors present a case of a ring avulsion amputation of the middle digit of a young patient's dominant hand. Due to the distal extent of avulsion, the amputated digit was determined to be nonreplantable, and the patient's medical comorbidities precluded traditional delayed pedicle flap options. Therefore, a reverse radial adipofascial flap was used as a single-stage reconstruction to resurface the entirety of the circumferential digital defect. At 8 months of follow up, the patient demonstrated exceptional passive and active range of motion with excellent contour and cosmesis, illustrating the utility of this reconstructive option.

A transcriptomic dataset evaluating the effect of radiotherapy injury on cells of skin and soft tissue.

Radiotherapy injury to cells of the skin and subcutaneous tissue is an inevitable consequence of external beam radiation for treatment of cancer. This sublethal injury to normal tissues plays a significant role in the development of fibrosis, lymphedema, impaired wound healing, and recurrent infections. To elucidate the transcriptional changes that occur in cells of the skin and soft tissues after radiotherapy injury, we performed genome-wide RNA-sequencing comparing irradiated cells (10Gy) with non-irradiated (0Gy) controls in normal human dermal fibroblasts, normal human keratinocytes, human microvascular endothelial cells, human dermal lymphatic endothelial cells, pericytes and adipose derived stem cell populations. These data are publicly available from the Gene Expression Omnibus database (accession number GSE184119). Further insights can be gained by comparing the mRNA signatures arising from radiation injury derived from these data to publicly available signatures from other studies involving similar or different tissue types. These global targets hold potential for manipulation to mitigate radiotherapy soft tissue injury.

Defining the Reliability of Deltoid Reanimation by Nerve Transfer When Using Abnormal but Variably Recovered Triceps Donor Nerves.

Upper brachial plexus injuries to the C5/6 roots or axillary nerve can result in severe deficits in upper limb function. Current techniques to reinnervate the deltoid muscle utilise the well-described transfer of radial nerve branches to triceps to the axillary nerve. However, in around 25% of patients, there is a failure of sufficient deltoid reinnervation. It is unclear in the literature if deltoid reanimation should be attempted with a nerve transfer from a weak but functioning triceps nerve. The authors present the largest series of triceps to axillary nerve transfers for deltoid reanimation in order to answer this clinical question. Seventy-seven consecutive patients of a single surgeon were stratified and analysed in four groups: (1) normal triceps at presentation, (2) abnormal triceps at presentation recovering to clinically normal function preoperatively, (3) abnormal triceps at presentation remaining abnormal preoperatively, and lastly (4) where pre-operative triceps function was deemed insufficient for use, requiring alternative reconstruction for deltoid reanimation. The authors considered deltoid re-animation of ≥ M4 as successful for the purpose of this study. Median Medical Research Council (MRC) values demonstrate group 1 achieves this successfully (M5), while median values for groups 2-4 result in M4 power (albeit with decreasing interquartile ranges). Median post-operative shoulder abduction active range of motion (AROM) values were represented by 170° (85-180) in group 1, 117.5° (97.5-140) in group 2, 90° (35-150) in group 3, and 60° (40-155) in group 4. For both post-operative assessments, subgroup analyses demonstrated statistically significant differences when comparing group 1 with groups 3 and 4 (p < 0.05), while all the other group to group pairwise comparisons did not reach significance. The authors postulated that triceps deficiency can act as a surrogate marker of a more extensive plexus injury and may predict poorer outcomes if the weakness persists representing the trending differences between groups 2 and 3. However, given no statistical differences were demonstrated between groups 3 and 4, the authors conclude that utilising an abnormal triceps nerve that demonstrates sufficient strength and redundancy intraoperatively is preferable to alternative transfers for deltoid reanimation. Lastly, in group 4 patients where triceps nerves are damaged and unusable for nerve transfer, alternative operations can also achieve sufficient outcomes and should be considered for restoration of shoulder abduction.

Radiological assessment of facial fractures: a comparative study between surgeon and radiologist.

BACKGROUND: The authors aimed to examine the differences in CT facial bone interpretation by the faciomaxillary surgeon and the radiologist, in order to improve communication gaps and subsequently, the quality and consistency of patient care. METHODS: This study was conducted at a level I tertiary trauma centre. Patients with facial trauma who were referred to the faciomaxillary unit following a facial CT examination from August 2017 to September 2018 were eligible for inclusion. The inclusion period was extended to 5 years for panfacial trauma patients. All consecutive patients that fulfilled the study inclusion criteria for each type of injury were included in the study (a total of 120 patients assigned to the following six categories: orbits, skull and skull base, zygomaticomaxillary complex, Le Fort pattern, mandible and pan-facial fractures). Faciomaxillary surgeons, blinded to the radiology report, were asked to provide a verbal description of the fractures. The surgical interpretation was compared to the radiology report and further analysed. RESULTS: Of the 120 cases, the same fractures were reported in 43 cases (35.8%). Both types of specialists noted the predominant and clinically relevant fractures in 106 cases (88.3%). The reports did not match in 14 cases (11.7%) and different terminology was used in 76 cases (63.3%), with agreement in 25% (95% CI: 18-34%), partial agreement in 11.7% (95% CI: 5.9-17.4%) and no agreement in 63.3% (95% CI: 54.7-72.0%) cases. CONCLUSION: Radiologists and faciomaxillary surgeons frequently differ in their assessment of facial fractures.

Case Report: Revisiting the Internal Mammary Artery Perforator Flap: Salvage Option for Circumferential Pharyngo-Esophageal Defects.

Patients that present with pharyngeal strictures and pharyngocutaneous fistulas in the context of previous reconstruction and post-operative radiotherapy often report significant morbidity and reduction in quality of life. Reconstruction of such defects present a substantial clinical challenge requiring the importation of unirradiated vascularized tissue to facilitate healing in a friable, fibrotic, and vessel depleted tissue bed. The authors present a case report demonstrating an adaptation of the internal mammary artery perforator (IMAP) flap for reliable reconstruction of circumferential pharyngeal defects with primary tension free closure of the donor site. This technique avoids the use of free tissue transfer in a hostile, irradiated neck. The tubed IMAP flap is an excellent option, serving the purposes of reconstruction as well as addressing the patient's presenting issues of a chronic sinus and pharyngeal stricture inhibiting oral intake.

Therapeutic Reversal of Radiotherapy Injury to Pro-fibrotic Dysfunctional Fibroblasts In Vitro Using Adipose-derived Stem Cells.

Cancer patients often require radiotherapy (RTx) to enhance their survival. Unfortunately, RTx also damages nearby healthy non-cancer tissues, leading to progressive fibrotic soft-tissue injury, consisting of pain, contracture, tissue-breakdown, infection, and lymphoedema. Mechanisms underlying the clinically observed ability of fat grafting to ameliorate some of these effects, however, are poorly understood. It was hypothesized that RTx significantly alters fibroblast cell function and the paracrine secretome of adipose-derived stem cells (ADSC) may mitigate these changes. METHODS: To investigate cellular changes resulting in the fibrotic side-effects of RTx, cultured normal human dermal fibroblasts (NHDF) were irradiated (10Gy), then studied using functional assays that reflect key fibroblast functions, and compared with unirradiated controls. RNA-Seq and targeted microarrays (with specific examination of TGFß) were performed to elucidate altered gene pathways. Finally, conditioned-media from ADSC was used to treat irradiated fibroblasts and model fat graft surgery. RESULTS: RTx altered NHDF morphology, with cellular functional changes reflecting transition into a more invasive phenotype: increased migration, adhesion, contractility, and disordered invasion. Changes in genes regulating collagen and MMP homeostasis and cell-cycle progression were also detected. However, TGFß was not identified as a key intracellular regulator of the fibroblast response. Finally, treatment with ADSC-conditioned media reversed the RTx-induced hypermigratory state of NHDF. CONCLUSIONS: Our findings regarding cellular and molecular changes in irradiated fibroblasts help explain clinical manifestations of debilitating RTx-induced fibrosis. ADSC-secretome-mediated reversal indicated that these constituents may be used to combat the devastating side-effects of excessive unwanted fibrosis in RTx and other human fibrotic diseases.

Fat Therapeutics: The Clinical Capacity of Adipose-Derived Stem Cells and Exosomes for Human Disease and Tissue Regeneration.

Fat grafting is a well-established surgical technique used in plastic surgery to restore deficient tissue, and more recently, for its putative regenerative properties. Despite more frequent use of fat grafting, however, a scientific understanding of the mechanisms underlying either survival or remedial benefits of grafted fat remain lacking. Clinical use of fat grafts for breast reconstruction in tissues damaged by radiotherapy first provided clues regarding the clinical potential of stem cells to drive tissue regeneration. Healthy fat introduced into irradiated tissues appeared to reverse radiation injury (fibrosis, scarring, contracture and pain) clinically; a phenomenon since validated in several animal studies. In the quest to explain and enhance these therapeutic effects, adipose-derived stem cells (ADSCs) were suggested as playing a key role and techniques to enrich ADSCs in fat, in turn, followed. Stem cells - the body's rapid response 'road repair crew' - are on standby to combat tissue insults. ADSCs may exert influences either by releasing paracrine-signalling factors alone or as cell-free extracellular vesicles (EVs, exosomes). Alternatively, ADSCs may augment vital immune/inflammatory processes; or themselves differentiate into mature adipose cells to provide the 'building-blocks' for engineered tissue. Regardless, adipose tissue constitutes an ideal source for mesenchymal stem cells for therapeutic application, due to ease of harvest and processing; and a relative abundance of adipose tissue in most patients. Here, we review the clinical applications of fat grafting, ADSC-enhanced fat graft, fat stem cell therapy; and the latest evolution of EVs and nanoparticles in healing, cancer and neurodegenerative and multiorgan disease.

Inhibition of glioblastoma cell proliferation, migration and invasion by the proteasome antagonist carfilzomib.

Glioblastoma multiforme is the most aggressive and lethal tumor of the central nervous system with limited treatment strategies on offer, and as such the identification of effective novel therapeutic agents is paramount. To examine the efficacy of proteasome inhibitors, we tested bortezomib, carfilzomib, nafamostat mesylate, gabexate mesylate and acetylsalicylic acid on glioblastoma cell viability, migration and invasion. Both bortezomib and carfilzomib produced significant reduction of cell viability, while nafamostat mesylate, gabexate mesylate and acetylsalicylic acid did not. Subsequent testing showed that carfilzomib significantly reduced cell viability at nM concentrations. Carfilzomib also reduced cell migration, secretion and activation of MMP2 and also cell invasion of all four glioblastoma cells tested. In summary, carfilzomib represents a novel, yet FDA-approved agent for the treatment of glioblastoma multiforme.

A novel literature-based approach to identify genetic and molecular predictors of survival in glioblastoma multiforme: Analysis of 14,678 patients using systematic review and meta-analytical tools.

Glioblastoma multiforme (GBM) has a poor prognosis despite maximal multimodal therapy. Biomarkers of relevance to prognosis which may also identify treatment targets are needed. A few hundred genetic and molecular predictors have been implicated in the literature, however with the exception of IDH1 and O6-MGMT, there is uncertainty regarding their true prognostic relevance. This study analyses reported genetic and molecular predictors of prognosis in GBM. For each, its relationship with univariate overall survival in adults with GBM is described. A systematic search of MEDLINE (1998-July 2010) was performed. Eligible papers studied the effect of any genetic or molecular marker on univariate overall survival in adult patients with histologically diagnosed GBM. Primary outcomes were median survival difference in months and univariate hazard ratios. Analyses included converting 126 Kaplan-Meier curves and 27 raw data sets into primary outcomes. Seventy-four random effects meta-analyses were performed on 39 unique genetic or molecular factors. Objective criteria were designed to classify factors into the categories of clearly prognostic, weakly prognostic, non-prognostic and promising. Included were 304 publications and 174 studies involving 14,678 unique patients from 33 countries. We identified 422 reported genetic and molecular predictors, of which 52 had ⩾2 studies. IDH1 mutation and O6-MGMT were classified as clearly prognostic, validating the methodology. High Ki-67/MIB-1 and loss of heterozygosity of chromosome 10/10q were classified as weakly prognostic. Four factors were classified as non-prognostic and 13 factors were classified as promising and worthy of additional investigation. Funnel plot analysis did not identify any evidence of publication bias. This study demonstrates a novel literature and meta-analytical based approach to maximise the value that can be derived from the plethora of literature reports of molecular and genetic factors in GBM. Caution is advised in over-interpreting the results due to study limitations. Further research to develop this methodology and improvements in study reporting are suggested.

Adipose-derived stem cells in radiotherapy injury: a new frontier.

Radiotherapy is increasingly used to treat numerous human malignancies. In addition to the beneficial anti-cancer effects, there are a series of undesirable effects on normal host tissues surrounding the target tumor. While the early effects of radiotherapy (desquamation, erythema, and hair loss) typically resolve, the chronic effects persist as unpredictable and often troublesome sequelae of cancer treatment, long after oncological treatment has been completed. Plastic surgeons are often called upon to treat the problems subsequently arising in irradiated tissues, such as recurrent infection, impaired healing, fibrosis, contracture, and/or lymphedema. Recently, it was anecdotally noted - then validated in more robust animal and human studies - that fat grafting can ameliorate some of these chronic tissue effects. Despite the widespread usage of fat grafting, the mechanism of its action remains poorly understood. This review provides an overview of the current understanding of: (i) mechanisms of chronic radiation injury and its clinical manifestations; (ii) biological properties of fat grafts and their key constituent, adipose-derived stem cells (ADSCs); and (iii) the role of ADSCs in radiotherapy-induced soft-tissue injury.

Randomized blinded control trial into tourniquet tolerance in awake volunteers.

BACKGROUND: The ability to tolerate a tourniquet is often the limiting factor to elective and emergent procedures of the upper limb performed under local anaesthesia. This study aims to demonstrate that upper limb tourniquets are more predictably and better tolerated when inflated to 200 mmHg than to the traditional inflation pressure of 250 mmHg in awake, unsedated subjects. METHODS: Forty healthy volunteers were randomized to have a tourniquet applied at either 200 or 250 mmHg for 20 min. Vital signs and pain scores were measured pre-test, at intervals throughout the time the tourniquet was inflated and post-deflation until the parameters normalized. Grip strength was measured pre-test, immediately post-deflation of the tourniquet and every 2 min until return of normal strength. RESULTS: All subjects were able to tolerate a tourniquet inflated for the allocated 20 min irrespective of the inflation pressure; however, there was a statistically significant lower average pain score in the group where the tourniquet was inflated to 200 mmHg compared with 250 mmHg. There was a quicker return of normal grip strength, although this was not shown to be statistically significant. CONCLUSIONS: Tourniquets inflated to 200 mmHg are better tolerated in awake, unsedated subjects that would allow predictably short procedures of the hand, wrist and forearm to be performed under local anaesthesia. It represents a pilot study prior to a further clinical study investigating the efficacy of tourniquets inflated to a lower pressure in maintaining an effective bloodless field.

Preoperative radiation and free flap outcomes for head and neck reconstruction: a systematic review and meta-analysis.

BACKGROUND: There is a general consensus among reconstructive surgeons that preoperative radiotherapy is associated with a higher risk of flap failure and complications in head and neck surgery. Opinion is also divided regarding the effects of radiation dose on free flap outcomes and timing of preoperative radiation to minimize adverse outcomes. Our meta-analysis will attempt to address these issues. METHOD: A systematic review of the literature was conducted in concordance to PRISMA protocol. Data were combined using STATA 12 and Open Meta-Analyst software programmes. RESULTS: Twenty-four studies were included comparing 2842 flaps performed in irradiated fields and 3491 flaps performed in non-irradiated fields. Meta-analysis yielded statistically significant risk ratios for flap failure (RR 1.48, P = 0.004), complications (RR 1.84, P < 0.001), reoperation (RR 2.06, P < 0.001) and fistula (RR 2.05, P < 0.001). Mean radiation dose demonstrated a trend towards increased risk of flap failure, but this was not statistically significant. On subgroup analysis, flaps with >60 Gy radiation had a non-statistically significant higher risk of flap failure (RR 1.61, P = 0.145). CONCLUSION: Preoperative radiation is associated with a statistically significant increased risk of flap complications, failure and fistula. Preoperative radiation in excess of 60 Gy after radiotherapy represents a potential risk factor for increased flap loss and should be avoided where possible.