Wessely corneal ring phenomenon: An unsolved pathophysiological dilemma.

The cornea is a densely innervated avascular tissue showing exceptional inflammatory and immune responses. The cornea is a site of lymphangiogenic and angiogenic privilege devoid of blood and lymphatic vessels that limits the entry of inflammatory cells from the adjacent and highly immunoreactive conjunctiva. Immunological and anatomical differences between the central and peripheral cornea are also necessary to sustain passive immune privilege. The lower density of antigen-presenting cells in the central cornea and the 5:1 peripheral-to-central corneal ratio of C1 are two main features conferring passive immune privilege. C1 activates the complement system by antigen-antibody complexes more effectively in the peripheral cornea and, thus, protects the central corneas' transparency from immune-driven and inflammatory reactions. Wessely rings, also known as corneal immune rings, are noninfectious ring-shaped stromal infiltrates usually formed in the peripheral cornea. They result from a hypersensitivity reaction to foreign antigens, including those of microorganism origin. Thus, they are thought to be composed of inflammatory cells and antigen-antibody complexes. Corneal immune rings have been associated with various infectious and noninfectious causes, including foreign bodies, contact lens wear, refractive procedures, and drugs. We describe the anatomical and immunologic basis underlying Wessely ring formation, its causes, clinical presentation, and management.

Customizable Collagen Vitrigel Membranes and Preliminary Results in Corneal Engineering.

Corneal opacities are a leading cause of visual impairment that affect 4.2 million people annually. The current treatment is corneal transplantation, which is limited by tissue donor shortages. Corneal engineering aims to develop membranes that function as scaffolds in corneal cell transplantation. Here, we describe a method for producing transplantable corneal constructs based on a collagen vitrigel (CVM) membrane and corneal endothelial cells (CECs). The CVMs were produced using increasing volumes of collagen type I: 1X (2.8 µL/mm2), 2X, and 3X. The vitrification process was performed at 40% relative humidity (RH) and 40 °C using a matryoshka-like system consisting of a shaking-oven harboring a desiccator with a saturated K2CO3 solution. The CVMs were characterized via SEM microscopy, cell adherence, FTIR, and manipulation in an ex vivo model. A pilot transplantation of the CECs/CVM construct in rabbits was also carried out. The thickness of the CVMs was 3.65-7.2 µm. The transparency was superior to a human cornea (92.6% = 1X; 94% = 2X; 89.21% = 3X). SEM microscopy showed a homogenous surface and laminar organization. The cell concentration seeded over the CVM increased threefold with no significant difference between 1X, 2X, and 3X (p = 0.323). The 2X-CVM was suitable for surgical manipulation in the ex vivo model. Constructs using the CECs/2X-CVM promoted corneal transparency restoration.

Hybrid revascularization vs. coronary bypass for coronary artery disease: a systematic review and meta-analysis.

INTRODUCTION: Coronary artery bypass graft is the mainstay of treatment for multivessel coronary artery disease and is superior to percutaneous coronary intervention. Combined approaches such as hybrid coronary revascularization integrate coronary artery bypass grafting with percutaneous coronary intervention during the same procedure or weeks apart. These attempt to improve surgical morbidity and long-term outcomes. EVIDENCE ACQUISITION: Per PRISMA criteria, a systematic review of keywords "Hybrid Revascularization," "Hybrid Coronary Revascularization," "Surgical," "Surgery," "Treatment," "CABG," "HCR" and "PCI" was conducted in PubMed, EMBASE and SCOPUS. Studies comparing this technique's performance on either single or two-stage approach against traditional multiple vessel coronary artery bypass grafting were screened and analyzed for our review. EVIDENCE SYNTHESIS: Twenty-two studies totaling 6981 participants were ultimately included for analysis. Mean differences in operative time, bleeding, ventilator time and length of stay were significantly lower in the hybrid coronary revascularization group. Odds ratios in transfusions and in-hospital myocardial infarction were also lower in the hybrid coronary revascularization group. Results for in-hospital and all-cause mortality, major adverse cardiac events (MACE), stroke, reintervention, and complete revascularization were not significantly different. CONCLUSIONS: Our analysis shows hybrid coronary revascularization is a feasible alternative to traditional coronary artery bypass grafting. Short-and long-term outcomes including mortality, MACE, and postoperative morbidity are similar between both groups, while hybrid approaches are associated with decreased perioperative morbidity.

Laparoscopic vs open portoenterostomy in biliary atresia: a systematic review and meta-analysis.

Hepatoportoenterostomy remains the cornerstone of treatment for biliary atresia. Current employed techniques include laparoscopy and open surgery. This study aims to determine if either method provides an advantage. Following PRISMA guidelines, a systematic review was conducted. Nineteen studies were included. Mean operative time 34.98 (95% CI 20.10, 49.85; p ≤ 0.00001) was longer in laparoscopic while bleeding volumes - 16.63 (95% CI - 23.39, - 9.86; p ≤ 0.00001) as well as the time to normal diet - 2.42 (95% CI - 4.51, - 0.32; p = 0.02) were lower in the laparoscopic group. No differences were observed in mean length of stay - 0.83. Similar complication, transfusions, postoperative cholangitis 0.97, and transplant free survival rates 1.00 (0.63, 1.60; p = 0.99) were seen between groups. Laparoscopic portoenterostomy provides advantages on operative time and bleeding as well as to normal diet when compared to open procedures. Both procedures showed no differences in length of stay, complications, cholangitis, and importantly, native liver survival. Level of evidence: III.