Abstract:

In the past three decades, the prevalence of aortic aneurysms has increased threefold. Incidence of aortic aneurysms increases with age and as the population ages, the prevalence increases. Population-based studies have shown that 10% of men over the age of 70 have abdominal aortic aneurysms. After many years of research, the exact pathogenesis of degenerative aneurysms -the most common form of aneurysm- is still unknown, although a number of factors including genetic, protelytic enzymes, hemodynamics, inflammation, and infection have been implicated.

Authors:

Christopher K. Zarins. M.D., F.A.C.S., Stanford University School of Medicine, Stanford, CA; Ramin E. Beygui, M.D., Stanford University Medical Center, Stanford, CA

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Abstract:

Three isoforms of endothelin (ET) exist, ET-l, ET-2,and ET-3.Nucleotide sequences for the three human ET genes are highly conserved. ET-l exactly matches the sequence ofET originally isolated from the conditioned medium of cultured bovine aortic endothelial cells (BAECs). All three forms have been found in vascular, neural, adrenal, and kidney tissue, but are expressed in different proportions. Endothelial cells exclusively produce ET_1. All three isoforms have different vasoconstrictive potencies but are otherwise qualitatively similar. ET-2 is the most potent vasoconstrictor, followed by ET-l and ET_3.

Authors:

Jason T. Koo, M.D., Mark D. Sawyer, M.D., Richard J. Powell, M.D., Bauer E. Sumpio, M.D., Ph.D., F.A.C.S., Yale University School of Medicine, New Haven, CT

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Abstract:

Interventional cardiology has undergone exciting changes since the first percutaneous transluminal coronary angioplasty was performed by Andreas Gruentzig in 1977. Over the last several years, a variety of techniques have been developed which provide the interventional cardiologist with a range of options to treat coronary stenoses. In addition, the indications for intervention have radically changed since the original work by Gruentzig, who limited treatment to patients with a single focal stenosis in a large vessel. Advances in balloon angioplasty, as well as the development of new techniques such as directional atherectomy, laser angioplasty, rotational atherectomy, extraction atherectomy, and now intracoronary stents have given the interventional cardiologist the ability to treat multivessel disease, increasingly complex lesions, and less stable patients.

Authors:

Jason T. Koo, M.D., Mark D. Sawyer, M.D., Richard J. Powell, M.D., Bauer E. Sumpio, M.D., Ph.D., F.A.C.S., Yale University School of Medicine, New Haven, CT

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Abstract:

Based on the concept of endoluminal aneurysm exclusion, we began to develop a plan for endovascular treatment for abdominal aortic aneurysm (AAA) in 1976. Two prototypes have been developed and were marked by a high failure rate. The first was a thin fabric graft mounted on a metallic cage-like structure composed by a self-expandable mesh with a zigzag configuration. The apparatus was compressed inside a tubular sheath, which acted as a vessel introducer and carrier. Experiments in normal canine aortas led to the abandonment of this prototype due to an inconsistent deployment of the metallic cage. The radial expansion properties of the cage were difficult to control and predict. Over-expansion resulted in aortic wall injury and subsequent rupture. Controversially, underexpansion led to leakage of blood between the apparatus and the host aorta with subsequent device migrations. The second prototype involved a Dacron graft fitted on a Silastic bag with a cylindrical lumen, which could be distended by injection of silicone into the bag. Unfortunately, this method was associated with prompt graft thrombosis of the aorta in all experimental essays.

Authors:

Juan Carlos Parodi, M.D., Bowman Gray School of Medicine, Wake Forest University, Winston-Salem, NC; Instituto Cardiovascular de Buenos Aires, Buenos Aires, Argentina

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Abstract:

Minimally invasive techniques have been gaining popularity in all fields of surgery. Their application to vascular surgery has spawned advances in endovascular treatment of aneurysmal and atherosclerotic arterial disease. These procedures are dependent on various imaging modalities, including angiography, intravascular ultrasound, and computerized tomography scanning to choose appropriate candidates and devices, and to assure precise en do luminal treatment. No single imaging method is adequate for all aspects of endovascular surgery; however, an algorithmic approach may judiciously reduce the inherent inaccuracy and morbidity associated with current methods.

Authors:

Eric P. Wilson, M.D., George E. Kopchok, B.S., Rodney A. White, M.D., F.A.C.S., UCLA School of Medicine, Harbor/UCLA Medical Center, Torrance, CA

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Abstract:

Spinal cord protection is of extreme importance to avoid the catastrophic complication of paraplegia related to surgery for thoracic and thoracoabdominal aortic disease. Spinal cord injury from surgically induced ischemia for aortic surgery has a variable risk of paraplegia. The incidence of spinal cord injury varies extensively-aneurysms of the proximal descending thoracic aorta and thoracoabdominal aorta 3% to 35%; to repair of traumatic rupture of the thoracic aorta performed with simple cross-clamping without distal perfusion, 25%; to repair of acute type B dissections of the thoracoabdominal aorta, as high as 35%.

Authors:

W.R. Eric Jamieson, M.D., F.R.C.S.(c), Michael T. Janusz, M.D., F.R.C.S.(c), Hilton Ling, M.D., F.R.C.S.(c), Vancouver Hospital and Health Sciences Centre, St. Paul's Hospital and Health Centre (University Heart Centre), University of British Columbia, Vancouver, BC, Canada

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Abstract:

Despite improvements in surgical practice and postoperative care, the large transperitoneal approaches used in elective aortic reconstructive surgery are still associated with a relatively high perioperative morbidity and mortality rate, even in patients who are good risks for undergoing aortic surgery. This perioperative morbidity is partly caused by major surgical trauma.

Authors:

György Weber, M.D., Ph.D., Medical University of Pecs, Pecs, Hungary; Geza J. Jako, M.D., Boston University School of Medicine, Boston, MA; Zoltan Szabo, Ph.D., F.I.C.S., M.O.E.T. Institute, San Francisco, CA, Fetal Treatment Center, Division of Pediatric Surgery, University of California School of Medicine, San Francisco, CA

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