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Dive into the research topics where Joshua A. Gillis is active.

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Featured researches published by Joshua A. Gillis.


Plastic and Reconstructive Surgery | 2015

Reply: Alternatively Activated M2 Macrophages Improve Autologous Fat Graft Survival in a Mouse Model through Induction of Angiogenesis.

Kyle D. Phipps; Simon Gebremeskel; Joshua A. Gillis; Paul Hong; Brent Johnston; Michael Bezuhly

Background: Variability in graft retention with subsequent undercorrection remains a significant limitation of autologous fat grafting. The authors evaluated whether graft retention in a mouse model could be improved via graft supplementation with alternatively activated M2 macrophages, cells known to play a critical role in tissue repair. Methods: Grafts from C57BL/6 mouse inguinal fat pads were supplemented with M2 macrophages generated by intraperitoneal Brewer’s thioglycollate injection and in vitro culture. Grafts with saline or M2 macrophages were injected under recipient mouse scalps and assessed by serial micro–computed tomographic analysis. Explanted grafts underwent immunohistochemical and flow cytometric analyses. M2 culture supernatants were added to stromal vascular fraction adipose-derived stem cells to assess adipogenic gene expression induction. Results: One month after graft injection, no significant difference was noted between M2 macrophage–supplemented (105 ± 7.0 mm3) and control graft volumes (72 ± 22 mm3). By 3 months after injection, M2 macrophage–supplemented grafts remained stable, whereas controls experienced further volume loss (103 ± 8 mm3 versus 39.4 ± 15 mm3; p = 0.015). Presence of macrophages in supplemented grafts was confirmed by flow cytometry. M2 macrophage–supplemented grafts exhibited a 157 percent increase in vascular density compared with controls (p < 0.05). Induction of adipogenic C/EBP&agr; gene expression was observed with M2 supernatants addition to stromal vascular fraction adipose-derived stem cells. Conclusions: M2 macrophages improve autologous fat graft volume retention by stimulating angiogenesis. These findings provide proof-of-principle for development of fat grafting techniques that harness reparative properties of M2 macrophages.


Canadian Journal of Plastic Surgery | 2011

Review of thumb carpometacarpal arthritis classification, treatment and outcomes.

Joshua A. Gillis; Kevin Calder; Jason Williams

Thumb carpometacarpal osteoarthritis (CMC OA) is a common disease, affecting up to 11% and 33% of men and women in their 50s and 60s, respectively, which leads to pain, laxity and weakness of the CMC joint. Based on the staging of the CMC OA, different forms of treatment can be used, including both conservative and surgical measures. Surgical options include osteotomy, trapezial excision, ligament reconstruction with or without tendon interposition, and various prosthetic interpositional implants with or without trapezial excision. The present article reviews the staging of CMC OA, the evaluation of hand function using patient-reported questionnaires, and outcomes of both conservative and surgical treatments. The present review also introduces a commercially available interpositional spacer surgical technique for CMC OA and the early evidence that the literature has shown for improving hand function, strength and stability of the thumb CMC joint postoperatively.


Plastic and Reconstructive Surgery | 2015

Effect of N-Acetylcysteine on Adipose-Derived Stem Cell and Autologous Fat Graft Survival in a Mouse Model.

Joshua A. Gillis; Simon Gebremeskel; Kyle D. Phipps; Lori A. MacNeil; Christopher J. Sinal; Brent Johnston; Paul Hong; Michael Bezuhly

Background: Autologous fat grafting is a popular reconstructive technique, but is limited by inconsistent graft retention. The authors examined whether a widely available, clinically safe antioxidant, N-acetylcysteine, could improve adipose-derived stem cell survival and graft take when added to tumescent solution during fat harvest. Methods: Inguinal fat pads were harvested from C57BL/6 mice using tumescent solution with or without N-acetylcysteine. Flow cytometric, proliferation, and differentiation assays were performed on isolated primary adipose-derived stem cells and 3T3-L1 preadipocytes treated with or without hydrogen peroxide and/or N-acetylcysteine. N-Acetylcysteine–treated or control grafts were injected under recipient mouse scalps and assessed by serial micro–computed tomographic volumetric analysis. Explanted grafts underwent immunohistochemical analysis. Results: In culture, N-acetylcysteine protected adipose-derived stem cells from oxidative stress and improved cell survival following hydrogen peroxide treatment. Combined exposure to both N-acetylcysteine and hydrogen peroxide led to a 200-fold increase in adipose-derived stem cell proliferation, significantly higher than with either agent alone. N-Acetylcysteine decreased differentiation of adipose-derived stem cells into mature adipocytes, as evidenced by decreased transcription of adipocyte differentiation markers and reduced Oil Red-O staining. In vivo, N-acetylcysteine treatment resulted in improved graft retention at 3 months compared with control (46 versus 17 percent; p = 0.027). N-Acetylcysteine–treated grafts demonstrated less fibrosis and inflammation, and a 33 percent increase in adipocyte density compared with controls (p < 0.001) that was not associated with increased vascularity. Conclusion: These findings provide proof of principle for the addition of N-acetylcysteine to tumescent harvest solution in the clinical setting to optimize fat graft yields.


Journal of Plastic Reconstructive and Aesthetic Surgery | 2017

Cost analysis of percutaneous fixation of hand fractures in the main operating room versus the ambulatory setting

Joshua A. Gillis; Jason Williams

PURPOSE To date, there have been no studies identifying the cost differential for performing closed reduction internal fixation (CRIF) of hand fractures in the operating room (OR) versus an ambulatory setting. Our goal was to analyse the cost and efficiency of performing CRIF in these two settings and to investigate current practice trends in Canada. METHODS A detailed analysis of the costs involved both directly and indirectly in the CRIF of a hand fracture was conducted. Hospital records were used to calculate efficiency. A survey was distributed to practicing plastic surgeons across Canada regarding their current practice of managing hand fractures. RESULTS In an eight-hour surgical block we are able to perform five CRIF in the OR versus eight in an ambulatory setting. The costs of performing a CRIF in the OR under local anaesthetic, not including surgeon compensation, is


Plast Surg (Oakv) | 2018

Visual Estimation of Dupuytren’s Flexion Contractures—A Prospective Comparative Trial

Joseph P. Corkum; Joshua A. Gillis; David T. Tang

461.27 Canadian (CAD) compared to


Archive | 2017

Umbilicoplasties Postabdominal Free Flap Harvest

Joey Corkum; Joshua A. Gillis; Ammar Al-Dhamin; Steven F. Morris

115.59 CAD in the ambulatory setting, a 299% increase. The use of a regional block increases the cost to


Archive | 2016

Coding System for CT Angiography of Inferior Epigastric Artery Perforators in DIEP Flaps

Joshua A. Gillis; Ammar Al-Dhamin; Steven F. Morris

665.49 CAD, a 476% increase. The main barrier to performing CRIFs in an outpatient setting is the absence of equipment necessary to perform these cases effectively, based on survey results. CONCLUSION The use of the OR for CRIF of hand fractures is associated with a significant increase in cost and hospital resources with decreased efficiency. For appropriately selected hand fractures, CRIF in an ambulatory setting is less costly and more efficient compared to the OR and resources should be allocated to facilitate CRIF in this setting.


Plastic and Reconstructive Surgery | 2015

Abstract 1: N-Acetylcysteine Improves Autologous Fat Graft Survival in a Mouse Model

Joshua A. Gillis; Simon Gebremeskel; Kyle D. Phipps; Lori A. MacNeil; Christopher J. Sinal; Brent Johnston; Paul Hong; Michael Bezuhly

Purpose: Surgeons and resident physicians in a clinic setting often visually estimate Dupuytren flexion contractures of the hand to follow disease progression and decide on management. No previous study has compared visual estimates with a standardized instrument to ensure measurement reliability. Methods: Consecutive patients consulted for Dupuytren flexion contractures of the hand had individual joint contractures estimated in degrees (°) by both a resident physician and staff surgeon. Estimates were compared with goniometer measurements to generate intraclass correlation coefficients (ICCs), and residents and surgeons were compared based on their accuracy. Results: Twenty-eight patients enrolled in this study, which provided a total of 80 hand joints for analysis. Resident physicians achieved an ICC of 0.42, which indicates poor reliability. The hand surgeon achieved an ICC of 0.86, which indicates high reliability. The surgeon also had better accuracy than the residents. Conclusion: Hand surgeons should be mindful of the limitations of visual estimates of Dupuytren flexion contractures, particularly when conducted by trainees. Joint angle measurements taken for the purposes of research should be done with a goniometer at minimum.


Plastic and Reconstructive Surgery | 2014

Three-dimensional printing of perforator vascular anatomy.

Joshua A. Gillis; Steven F. Morris

The umbilicus is a very important anatomic and physiologic landmark of the abdomen that represents a remnant of the umbilical stalk during embryological development. The use of autologous abdominal flaps for breast reconstruction has become increasingly popular, and repositioning of the umbilicus on the superior abdominal flap is an important aesthetic step of the operation. The neoumbilicus must be depressed and vertically oriented with an inconspicuous scar with minimal chance of cicatricial scarring to obtain proper results. We describe previously used techniques for umbilicoplasties postabdominoplasty or autologous abdominal tissue transfer and our technique to achieve an aesthetically pleasing umbilicus post-free abdominal flap transfer.


Journal of Plastic Reconstructive and Aesthetic Surgery | 2014

Levamisole-induced vasculopathy: Staging and management

Joshua A. Gillis; Peter J. Green; Jason Williams

The use of autologous abdominal tissue for breast reconstruction has become the gold standard. The highly variable anatomy of the inferior epigastric system has caused an increase in pre-operative computed tomographic angiography (CTA) studies to determine the dominant vascular pedicle of which to base the DIEP or SIEA flap. The use of a coding system based on the dominant perforators increases the utility of the CTA by improving communication between the radiologist and the surgeon, and also enhancing documentation of these perforators for research purposes. The authors describe their coordinate system of identifying perforators so that preoperatively the unique anatomy of the patient can be understood in order to shorten operating time and improve patient outcomes.

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