RESUMEN
Calcific aortic stenosis (AS) is primarily a disease of the elderly, possessing features that are biomechanical as well as systemic and inflammatory in nature, with risk factors and histopathology similar to atherosclerosis. To date no medical therapy has been shown to conclusively alter the progression of the disease, and for those with symptomatic AS, aortic valve replacement (AVR) is advocated. Factors that may alert the physician to an accelerated progression of calcific aortic valvular disease toward severe symptomatic AS include moderate aortic valve calcification, chronically dialyzed patients, and patients 80 years and older. There remains significant morbidity and mortality associated with AVR, and new techniques and technologies for AVR are being developed. For those who undergo successful AVR the long-term prognosis is good. A substantial number of patients with symptomatic AS present for anesthesia care for a variety of procedures. A thorough, modern understanding of AS and its course are necessary for the anesthesiologist to guide the patient through the perioperative period.
Asunto(s)
Anestesia , Estenosis de la Válvula Aórtica/cirugía , Anciano , Anciano de 80 o más Años , Estenosis de la Válvula Aórtica/clasificación , Estenosis de la Válvula Aórtica/diagnóstico , Estenosis de la Válvula Aórtica/patología , Estenosis de la Válvula Aórtica/fisiopatología , Progresión de la Enfermedad , Femenino , Humanos , Desprendimiento de Retina/cirugíaRESUMEN
Autogenous arteriovenous access is the preferred access for hemodialysis patients with end-stage renal disease but is not feasible in a significant number of patients. The creation of a prosthetic arteriovenous access (PAVA) for hemodialysis using expanded polytetrafluoroethylene is technically simple and the short-term results are usually good, but the PAVA's 1-year patency rate is low (less than 60% in many centers). We have developed an integrated approach for the creation and maintenance of PAVAs, under the direction of a dedicated vascular access surgeon, involving preoperative imaging, anesthetic and surgical techniques, and a postoperative graft surveillance program, to improve patency rates. The design used was a prospective nonrandomized study. Between January 1, 1999 and December 31, 2001, 158 PAVAs were created (37.7% of the 419 fistulae created during this period). High-resolution duplex ultrasonography was added to careful clinical assessment in planning and follow-up of the dialysis access. The preferred method of PAVA creation was the forearm loop using tapered 4 to 7 mm stretch expanded polytetrafluoroethylene. After surgery, patients entered a program of close follow-up and regular graft surveillance and maintenance. Prophylactic surgical revisions and endovascular interventions were performed routinely according to ultrasonography findings to prevent thrombosis. Thrombolysis and thrombectomy were performed without delay when the PAVA thrombosed, minimizing the use of central venous access and salvaging the central veins. No patients were excluded from the study. One-, 2-, and 3-year assisted primary patency rates (including patients without occlusion but who were judged to require prophylactic revision) were 65%, 54.1%, and 48.8%, respectively. With surveillance-directed surgical revisions and endovascular treatment before or after occlusion, the 1-, 2-, and 3-year secondary patency rates (functional patency) were 91.4%, 84.3%, and 78.5%. Of the 158 grafts, 110 never occluded during the study period. There were 155 interventions in 74 PAVAs: 30 surgical revisions, 63 prophylactic endovascular procedures, and 52 instances of thrombolytic therapy combined with percutaneous transluminal angioplasty. The use of prosthetic arteriovenous access for hemodialysis, when autogenous arteriovenous access is not feasible, can still be associated with excellent long-term patency, in spite of previously published poor results, as long as good planning, close follow-up, and aggressive intervention (when indicated) are carried out.