Remote ischemic conditioning: from experimental observation to clinical application: report from the 8th Biennial Hatter Cardiovascular Institute Workshop

In 1993, Przyklenk and colleagues made the intriguing experimental observation that 'brief ischemia in one vascular bed also protects remote, virgin myocardium from subsequent sustained coronary artery occlusion' and that this effect '.... may be mediated by factor(s) activated, produced, or transported throughout the heart during brief ischemia/reperfusion'. This seminal study laid the foundation for the discovery of 'remote ischemic conditioning' (RIC), a phenomenon in which the heart is protected from the detrimental effects of acute ischemia/reperfusion injury (IRI), by applying cycles of brief ischemia and reperfusion to an organ or tissue remote from the heart. The concept of RIC quickly evolved to extend beyond the heart, encompassing inter-organ protection against acute IRI. The crucial discovery that the protective RIC stimulus could be applied non-invasively, by simply inflating and deflating a blood pressure cuff placed on the upper arm to induce cycles of brief ischemia and reperfusion, has facilitated the translation of RIC into the clinical setting. Despite intensive investigation over the last 20 years, the underlying mechanisms continue to elude researchers. In the 8th Biennial Hatter Cardiovascular Institute Workshop, recent developments in the field of RIC were discussed with a focus on new insights into the underlying mechanisms, the diversity of non-cardiac protection, new clinical applications, and large outcome studies. The scientific advances made in this field of research highlight the journey that RIC has made from being an intriguing experimental observation to a clinical application with patient benefit

Access ligation in transplant patients.

Access surgeons will encounter patients with functioning transplants who want to lose their fistula, and every dialysis unit sees patients returning after a failed kidney transplant for whom an old fistula is a readily available lifeline. The decision is straightforward in patients with perfectly functioning transplants and disabling complications of their fistula, or in patients with failing transplants and a good fistula. The challenge is to make this decision in patients with good transplant function and an asymptomatic fistula. Despite improvements in one-year survival of renal grafts, the long-term graft survival has improved modestly. This means about half of the patients with a successful kidney transplant will return to dialysis within 10 years. Use of recently developed risk calculators, based on clinical parameters, may help in the decision process. A high flow fistula can lead to heart failure but most fistulae are well tolerated in asymptomatic patients and the effects of closure of the AVF on the heart are modest. Recent evidence suggests that there may be benefits of a functioning AVF that may need to be considered in this decision process. This article reviews the literature and comes to pragmatic recommendations of what to do with this conundrum