Increased mortality and perioperative complications in patients with previous elective percutaneous coronary interventions undergoing coronary artery bypass surgery.

OBJECTIVE: The relationship between previous percutaneous coronary intervention and perioperative outcome after coronary artery bypass grafting remains undetermined. The aim of the study was to investigate whether previous elective percutaneous coronary intervention influences the outcome of elective coronary artery bypass grafting. METHODS: Between 2002 and 2007, 4412 consecutive patients underwent first-time open surgery at the Innsbruck Medical University. After excluding patients with a history of emergency percutaneous coronary intervention, we isolated 306 patients with elective percutaneous coronary intervention during the last 24 months before isolated coronary artery bypass grafting (group 1). Those patients were compared with 452 consecutive age-, gender-, and EuroSCORE-matched patients without a history of percutaneous coronary intervention (group 2), in terms of 30-day mortality, major adverse cardiac events, and perioperative complications. RESULTS: Both groups were comparable concerning preoperative linear EuroSCORE (group 1: 4.83 +/- 0.18, group 2: 4.72 +/- 0.14, P = .63). Patients who underwent previous elective percutaneous coronary intervention before coronary artery bypass grafting had an increase in perioperative mortality (group 1: 4.4% vs group 2: 2.4%, P < .001) and major adverse cardiac events (group 1: 7.9% vs 4.3%, P < .001). In addition, the incidence of bleeding complications (group 1: 5.9% vs group 2: 3.8%, P = .017) and the number of blood products (group 1: 1.70 +/- 0.31 vs 0.61 +/- 0.17, P < .001) used were higher in patients of group 1. A higher incidence of acute renal failure (5.9% vs 2.7%, P = .025) and renal replacement therapy (3.6% vs 1.7%, P = .03) was observed in patients of group 1. CONCLUSION: Patients with a history of elective percutaneous coronary intervention before referral to coronary artery bypass grafting have a worse perioperative outcome in terms of mortality, major adverse cardiac events, and perioperative complications compared with patients without a history of percutaneous coronary intervention. This fact should be considered in risk stratification for patients who are scheduled for elective coronary artery bypass grafting.

Biochemical, biomechanical and histological properties of osteoarthritic porcine knee cartilage: implications for osteochondral transplantation.

INTRODUCTION: Cartilage lesions of the knee joint are frequently observed during arthroscopy and when surgical intervention is required, osteochondral autograft procedures are an established method of treatment. Frequently lesions are located on the medial femoral condyle (MFC), and typical donor locations for osteochondral grafts include the medial and lateral patellar groove. This technique provides good results, even when the quality of cartilage transplanted from an osteoarthritic joint is doubtful. This study characterizes biological, biomechanical and histological properties of cartilage explants from the patellar groove harvested from osteoarthritic joints. MATERIALS AND METHODS: Cylindrical cartilage explants were harvested from the arthritic areas of the MFC as well as normal appearing regions of the medial and lateral patellar groove from porcine joints revealing various grades of osteoarthritis. Matrix synthesis rates were determined, and explants were investigated by mechanical testing and histology. RESULTS: Articular cartilage obtained from the typical donor areas of the medial and lateral patellar groove provided constant enhanced material properties, matrix synthesis rates and histological appearance compared to samples from the arthritic lesions of the MFC, even in joints with end-stage osteoarthritis of the MFC. No significant difference was found between patellar groove cartilage samples harvested from joints with different stages of osteoarthritis. CONCLUSION: Our findings demonstrate that healthy appearing cartilage from the patellar groove does not undergo significant alterations in material properties due to the arthritic milieu present in osteoarthritic joints. Accordingly these locations provide a source of functional tissue for transplant procedures even in joints with end-stage osteoarthritis.

Regional differences in prostaglandin E2 and nitric oxide production in the knee meniscus in response to dynamic compression.

Injury or loss of the knee meniscus is associated with altered joint stresses that lead to progressive joint degeneration. The goal of this study was to determine if dynamic mechanical compression influences the production of inflammatory mediators by meniscal cells. Dynamic compression increased prostaglandin E2 (PGE(2)) and nitric oxide (NO) production over a range of stress magnitudes (0.0125-0.5 MPa) in a manner that depended on stress magnitude and zone of tissue origin. Inner zone explants showed greater increases in PGE(2) and NO production as compared to outer zone explants. Meniscal tissue expressed NOS2 and NOS3 protein, but not NOS1. Mechanically induced NO production was blocked by NOS inhibitors, and the non-selective NOS inhibitor L-NMMA augmented PGE(2) production in the outer zone only. These findings suggest that the meniscus may serve as an intra-articular source of pro-inflammatory mediators, and that alterations in the magnitude or distribution of joint loading could significantly influence the production of these mediators in vivo.

Repair response of the inner and outer regions of the porcine meniscus in vitro.

BACKGROUND: The menisci are essential intra-articular structures that contribute to knee function, and meniscal injury or loss is associated with joint degeneration. Tears of the outer vascularized zone have a greater potential for repair than do tears in the inner avascular region. OBJECTIVE AND HYPOTHESIS: Develop an in vitro explant model to examine the hypothesis that differences exist in the intrinsic repair response between the outer and inner region of the meniscus. STUDY DESIGN: Controlled laboratory study. METHODS: Cylindrical explants were harvested from the outer one third and inner two thirds of medial porcine menisci. To simulate a full-thickness defect, a central core was removed and reinserted immediately. Explants were cultured for 2, 4, or 6 weeks, and meniscal healing was investigated using mechanical testing, histologic analysis, and fluorescence confocal microscopy. RESULTS: Over the 6-week culture period, meniscal explants exhibited migration of cells into the repair site, followed by increased tissue formation that bridged the interface. The repair strength increased significantly over time, with no differences between the 2 regions. CONCLUSION: The findings show that explants from the avascular inner zone and vascular outer zone of the meniscus exhibit similar healing potential and repair strength in vitro. CLINICAL RELEVANCE: These findings support the hypothesis that the regional differences in meniscal repair observed clinically are owed to the additional vascular supply of the outer meniscus rather than intrinsic differences between the extracellular matrix and cells from these 2 areas.