Incomplete biochemical adaptation of vein grafts to the arterial environment in terms of prostacyclin production

Mechanotransduction in embryonic vascular development

A plethora of biochemical signals provides spatial and temporal cues that carefully orchestrate the complex process of vertebrate embryonic development. The embryonic vasculature develops not only in the context of these biochemical cues, but also in the context of the biomechanical forces imparted by blood flow. In the mature vasculature, different blood flow regimes induce distinct genetic programs, and significant progress has been made toward understanding how these forces are perceived by endothelial cells and transduced into biochemical signals. However, it cannot be assumed that paradigms that govern the mature vasculature are pertinent to the developing embryonic vasculature. The embryonic vasculature can respond to the mechanical forces of blood flow, and these responses are critical in vascular remodeling, certain aspects of sprouting angiogenesis, and maintenance of arterial-venous identity. Here, we review data regarding mechanistic aspects of endothelial cell mechanotransduction, with a focus on the response to shear stress, and elaborate upon the multifarious effects of shear stress on the embryonic vasculature. In addition, we discuss emerging predictive vascular growth models and highlight the prospect of combining signaling pathway information with computational modeling. We assert that correlation of precise measurements of hemodynamic parameters with effects on endothelial cell gene expression and cell behavior is required for fully understanding how blood flow-induced loading governs normal vascular development and shapes congenital cardiovascular abnormalities.

Common factors regulating patterning of the nervous and vascular systems

The vascular and the nervous systems of vertebrates share many features with similar and often overlapping anatomy. The parallels between these two systems extend to the molecular level, where recent work has identified ever-increasing similarities between the molecular mechanisms employed in the specification, differentiation, and patterning of both systems. This review discusses some of the most recent literature on this subject, with particular emphasis on the roles that the Ephrin, Semaphorin, Netrin, and Slit signaling pathways play in vascular development.

The Quality of Surgical Care Project: benchmark standards of open resection for abdominal aortic aneurysm in Western Australia

BACKGROUND

The Quality of Surgical Care Project (QSCP) was established in May 1996, to evaluate surgical outcomes and where indicated, recommend changes to improve the quality of surgical care in Western Australia (WA). The purpose of this study is to establish benchmark standards in WA for operative mortality, 5-year survival and length of stay in all patients who were surgically treated for aneurysm of the abdominal aorta (AAA) in WA.

METHODS

The WA Linked Database was used to link the morbidity and mortality records of all patients admitted and surgically treated for AAA in WA from 1985 to 1994. The linked chains of de-identified hospital morbidity and death records were selected using diagnostic and procedure codes pertaining to AAA. Three groups were separated for analysis: those admitted for rupture, those admitted for elective repair, and those who were admitted to hospital as an emergency without mention of rupture but who underwent repair for AAA. Independent analysis for gender and patients 80 years or more were included in the study. Patients were excluded from the study if they were less than 55 years of age.

RESULTS

A total of 1475 cases (1257 males, 218 females) were identified. The mean age in elective cases was 70.4 years in males and 72.4 years in females, and for rupture the mean ages were 71.9 and 74.8 years, respectively. Median length of stay for males was 12 days for elective cases. Admission type or age did not significantly influence length of stay. Thirty-day mortality in males was 4.4% for elective repair and 36.7% for ruptured AAA and 5-year survival was 71.7 and 47.7%, respectively. The overall case fatality rate for ruptured AAA was 79.3% which included those cases who died from rupture without being admitted to hospital.

CONCLUSIONS

These community-wide data provide a realistic measure of surgical performance for open repair of AAA. The outcomes for elective and rupture repair for AAA compare favourably with standards reported by international centres of excellence. They also support the use of this procedure in patients over 80 years of age with rupture. This information can be used for ongoing audit purposes and as a benchmark for the introduction of new treatment modalities.