Sabbah, Belal Nedal

Purpose: To systematically review the literature on the effectiveness, safety, and long-term outcomes of genicular artery embolization (GAE) for knee joint osteoarthritis (OA) associated pain. Materials and Methods: After registering the protocol with the PROSPERO database, a search was conducted from inception until July 31, 2023, in MEDLINE, Cochrane Central Register of Controlled Trials, and ScienceDirect databases to gather studies evaluating GAE’s safety and efficacy in knee OA. A total of 4979 studies were identified and evaluated against the inclusion criteria. Data on study characteristics, success parameters, and adverse events were collected and synthesized. Results: Twenty-three studies, primarily single-center prospective studies with a total of 657 patients, were included. Most studies reported a 100% technical success rates, except one study reporting a rate of 84.2%. Clinical success rates, defined variably across studies, ranged from 30% to 100%, depending on the study’s follow-up period and outcome measures. The most frequent adverse events included skin discoloration without an ulcer (15.6%, n = 98) and transient post-procedural knee pain (10.2%, n = 64). Most studies were rated as fair in terms of quality, but the lack of robust randomized controlled trials highlighted the need for further comparative studies to standardize outcome reporting. Conclusion: GAE appears to be a promising option for knee OA pain, particularly for patients unresponsive to conservative treatments or ineligible for surgery. High-quality studies are needed to confirm long-term effectiveness and standardize outcome measures. Clinical Impact This study highlights the safety and efficacy of genicular artery embolization as a minimally invasive treatment for knee osteoarthritis, particularly in patients who are unresponsive to conservative treatments or unsuitable for surgery. By targeting neovascularization and reducing inflammation, genicular artery embolization provides pain relief and functional improvement. Clinicians can consider genicular artery embolization as an alternative to surgery for mild-to-moderate OA, offering a lower adverse event rate and faster recovery.

To address the ongoing shortage of organs available for replacement, xenotransplantation of hearts, corneas, skin, and kidneys has been attempted. However, a major obstacle facing xenotransplants is rejection due to a cycle of immune reactions to the graft. Both adaptive and innate immune systems contribute to this cycle, in which natural killer cells, macrophages, and T-cells play a significant role. While advancements in the field of genetic editing can circumvent some of these obstacles, biomarkers to identify and predict xenograft rejection remain to be standardized. Several T-cell markers, such as CD3, CD4, and CD8, are useful in both the diagnosis and prediction of xenograft rejection. Furthermore, an increase in the levels of various circulating DNA markers and microRNAs is also predictive of xenograft rejection. In this review, we summarize recent findings on the advancements in xenotransplantation, with a focus on pig-to-human, the role of immunity in xenograft rejection, and its biomarkers.