Detection of coronary arteries and evaluation of anastomoses with a commercially available 15-MHz, broadband, linear array transducer

Intraoperative epicardial ultrasound probe for visualization of embedded coronary arteries: a novel approach

The identification of coronary anatomy at the time of cardiac revascularization can be problematic. Preoperative studies (ie, coronary angiography) can aid in the mapping of the coronary anatomy. However, there remain a select few patients with intramyocardial coronaries that provide challenges for surgical dissection during revascularization. Probing the visible portion of the coronary artery, intraoperative cine angiography, thermal angiography, and epicardial Doppler probes have been used to identify the coronary anatomy intraoperatively. Aggressive surgical maneuvers can result in damage and increased time on cardiopulmonary bypass. Previous studies have used epicardial echocardiography on patients undergoing off-pump coronary artery bypass grafting. We report 2 cases in patients undergoing cardiac revascularization on cardiopulmonary bypass where the use of a high-frequency epicardial ultrasound probe facilitated the identification of the embedded coronary arteries. We describe a technique of using antegrade and retrograde cardioplegia administration sequentially to locate the coronary arteries. Easy availability and familiar technology make the epicardial Doppler probe an attractive tool for the identification of embedded coronary arteries.

Acute renal venous obstruction is more detrimental to the kidney than arterial occlusion: implication for murine models of acute kidney injury

In this study, we compared the traditional murine model with renal pedicle clamp with models that clamped the renal artery or vein alone as well as to a whole body ischemia-reperfusion injury (WBIRI) model. Male C57BL/6J mice underwent either clamping of the renal artery, vein, or both (whole pedicle) for 30 or 45 min followed by reperfusion, or 10 min of cardiac arrest followed by resuscitation up to 24 h. After 30 min of ischemia, the mice with renal vein clamping showed the mostly increased serum creatinine and the most severe renal tubule injury. After 45 min of ischemia, all mice with renal vasculature clamping had a comparable increase in serum creatinine but the renal tubule injury was most severe in renal artery-clamped mice. Renal arterial blood flow was most decreased in mice with a renal vein clamp compared with a renal artery or pedicle clamp. A 30-or 45-min renal ischemia time led to a significant increase in the protein level of interleukin-6, keratinocyte-derived chemokine (KC), and granular colony-stimulating factor in the ischemic kidney, but the KC was the highest in the renal pedicle-clamped kidney and the lowest in the renal vein-clamped kidney. Of note, 10 min of WBIRI led to kidney dysfunction and structural injury, although less than longer time clamping of isolated renal vasculature. Our data demonstrate important differences in ischemic AKI models. Understanding these differences is important in designing future experimental studies in mice as well as clinical trials in humans.