Quantification of Lymphangiogenesis in the Murine Lymphedema Tail Model Using Intravital Microscopy.

Background: Lymphedema is chronic limb swelling resulting from lymphatic dysfunction. It affects an estimated five million Americans. There is no cure for this disease. Assessing lymphatic growth is essential in developing novel therapeutics. Intravital microscopy (IVM) is a powerful imaging tool for investigating various biological processes in live animals. Tissue nanotransfection technology (TNT) facilitates a direct, transcutaneous nonviral vector gene delivery using a chip with nanochannel poration in a rapid (<100 ms) focused electric field. TNT was used in this study to deliver the genetic cargo in the murine tail lymphedema to assess the lymphangiogenesis. The purpose of this study is to experimentally evaluate the applicability of IVM to visualize and quantify lymphatics in the live mice model. Methods and Results: The murine tail model of lymphedema was utilized. TNT was applied to the murine tail (day 0) directly at the surgical site with genetic cargo loaded into the TNT reservoir: TNTpCMV6 group receives pCMV6 (expression vector backbone alone) (n = 6); TNTProx1 group receives pCMV6-Prox1 (n = 6). Lymphatic vessels (fluorescein isothiocyanate [FITC]-dextran stained) and lymphatic branch points (indicating lymphangiogenesis) were analyzed with the confocal/multiphoton microscope. The experimental group TNTProx1 exhibited reduced postsurgical tail lymphedema and increased lymphatic distribution compared to TNTpCMV6 group. More lymphatic branching points (>3-fold) were observed at the TNT site in TNTProx1 group. Conclusions: This study demonstrates a novel, powerful imaging tool for investigating lymphatic vessels in live murine tail model of lymphedema. IVM can be utilized for functional assessment of lymphatics and visualization of lymphangiogenesis following gene-based therapy.

Medicaid Patients Travel Disproportionately Farther for Revision Total Joint Arthroplasty.

BACKGROUND: Access to high-quality care for revision total joint arthroplasty (rTJA) is poorly understood but may vary based on insurance type. This study investigated distance traveled for hip and knee rTJA based on insurance type. METHODS: A total of 317 revision hips and 431 revision knees performed between 2010 and 2020 were retrospectively reviewed. Cluster sampling was used to select primary hips and knees for comparison. Median driving distance was compared based upon procedure and insurance type. RESULTS: Revision hip and knee patients traveled 18.2 and 11.0 miles farther for surgery compared to primary hip and knee patients (P ≤ .001). For hip rTJA, Medicaid patients traveled farther than Medicare patients followed by commercially insured patients with median distances traveled of 98.4, 67.2, and 35.6 miles, respectively (P = .016). Primary hip patients traveled the same distance regardless of insurance type (P = .397). For knee rTJA, Medicaid patients traveled twice as far as Medicare and commercially insured patients (medians of 85.0, 43.5, and 42.2 miles respectively, P ≤ .046). Primary knee patients showed a similar pattern (P = .264). Age and ASA-PS classification did not indicate greater comorbidity in Medicaid patients. CONCLUSION: Insurance type may influence rTJA referrals, with disproportionate referral of Medicaid and Medicare patients to nonlocal care centers. In addition to patient burden, these patterns potentially present a financial burden to facilities accepting referrals. Strategies to improve equitable access to rTJA, while maintaining the highest and most economical standards of care for patients, providers, and hospitals, are encouraged.

Time Required for Planned and Unplanned Episodes of Care in Septic Two-Stage Revision Hip and Knee Arthroplasty.

BACKGROUND: Septic revision total hip (rTHA) and knee (rTKA) arthroplasty requires more effort but is reimbursed less than primary procedures per minute of intraoperative time. This study quantified planned and unplanned work performed by the surgical team for septic 2-stage revision surgeries during the entire episode-of-care "reimbursement window" and compared that time to allowable reimbursement amounts. METHODS: Between October 2010 and December 2020 all unilateral septic 2-stage rTHA and rTKA procedures performed by a single surgeon at a single institution were retrospectively reviewed. Time dedicated to planned work was calculated over each episode of care, from surgery scheduling to 90 days postoperatively. Impromptu patient inquiries and treatments after discharge, but within the episode of care, involving the surgeon/surgeon team constituted unplanned work. Planned and unplanned work minutes were summed and divided by the number of patients reviewed to obtain average minutes of work per patient. RESULTS: Sixty-eight hips and 64 knees were included. For 2-stage rTHA and rTKA the average time per patient for planned care was 1728 and 1716 minutes and for unplanned care was 339 and 237 minutes. Compared to the Centers for Medicare and Medicaid Services' allowable reimbursement times, an additional 799 and 887 minutes of uncompensated time was required to care for 2-stage rTHA and rTKA patients. CONCLUSION: Two-stage revision procedures are substantially more complex than primary procedures. Financially disincentivizing surgeons to care for these patients reduces access to care when high-quality care is most needed. These findings support increasing the allowable times for 2-stage septic revision cases.