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levels of CTGF and TGF-␤ will induce recruitment of myofibroblasts and provoke adventitial reorganization to limit outward remodeling of the vein graft in response to increased intramural wall stress.The authors created a model using a distal arterial venous fistula in the neck of rabbits that results in circumferential wall shear stress. Neck and fistula veins were harvested at 1, 3, and 7 days after implantation. Flow rates were recorded at the time of graft implantation and harvest using an ultrasonic flow meter. Real-time polymerase chain reaction and enzymelinked immunosorbent assays were used to assess production of CTGF and TGF-␤ 1 .With this model, the authors demonstrated increased production of TGF-␤ and CTGF in response to elevated wall stress. TGF-␤ and CTGF increased expression correlated with enhanced differentiation from fibroblasts to myofibroblasts, as reflected in increases in the ␣-actin-positive cells in the adventitia. Levels of ␣-actin, TGF-␤, and CTGF were all inversely correlated with outward remodeling of the graft wall.Comment: Wolinsky and Glagov originally demonstrated arterial adaption to maintain lumen diameter in atherosclerotic arteries. In vein grafts, this adaptive response might be limited by TGF-␤ and CTGF increases in myofibroblasts. Such an adaption may maintain vein wall integrity in the face of increased intraluminal pressure but may ultimately prove disadvantageous because it may limit the ability of the vein graft to maintain luminal diameter in response to the development of intimal hyperplasia. Temporary worsening of renal function after aortic surgery is associated with higher long-term mortalityWelten GM, Schouten O, Chonchol M, et al. Am J Kidney Dis 2007;50: 219-28. Conclusion: Temporary worsening of renal function after open surgery for abdominal aortic aneurysm (AAA) is associated with an increased long-term mortality rate.Summary: The authors sought to determine the effects of temporary renal dysfunction on the long-term mortality rate in patients undergoing AAA surgery. From January 1995 to June 2006, 1324 patients underwent elective open AAA repair in a single center in Rotterdam. Creatinine clearance was measured preoperatively and on postoperative days 1, 2, and 3. The patients were then divided into three groups. Group 1 had improved or unchanged renal function. Group 2 had temporary worsening of renal function with a Ͼ10% decrease on day 1 or 2, and then recovery Յ10% of baseline by day 3. Group 3 patients had persistent worsening of renal function as defined by a Ͼ10% decrease in creatinine clearance compared with the baseline value.The 30-day mortality rates in groups 1, 2, and 3 were 1.2%, 5%, and 12.6%, respectively. Adjusting for postoperative complications and baseline characteristics, the 30-day mortality rate was greatest in the patients with persistent worsening of renal function (hazard ratio (HR), 7.3; 95% confidence interval [CI], 2.7-19.8). Those who had temporary worsening of renal function also had an increased mortality risk (HR, 3.7; 95% CI...

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Modern treatment of acute pulmonary embolism requires rapid and accurate diagnosis followed by risk stratification to devise an optimal management strategy. Patients at low risk have good outcomes simply with intensive anticoagulation treatment. Higher-risk patients may require more aggressive intervention with thrombolysis or embolectomy.Clinical risk factors for an adverse outcome include increasing age, cancer, congestive heart failure, systemic arterial hypotension, chronic obstructive pulmonary disease and right ventricular dysfunction. A promising approach is the Geneva Prognostic Score, which is based upon a rapid clinical assessment.On physical examination, signs of right ventricular failure, including distended jugular veins and a right-sided S 3 gallop, should be looked for. The electrocardiogram may show evidence of right ventricular strain with a new right bundle branch block or T wave inversion in leads V1-V4. The troponin level may be elevated as a marker of cardiac injury and right ventricular microinfarction, even in the absence of coronary artery disease. The most useful imaging marker of high risk is the presence of moderate or severe right ventricular dilatation and hypokinesis on the echocardiogram, especially with progressively worsening right ventricular function despite intensive anticoagulation treatment.Patients at high risk should be considered for thrombolytic therapy or embolectomy rather than management with anticoagulation therapy alone. Special care must be taken to avoid thrombolytic therapy among patients who might be susceptible to intracranial haemorrhage. Intracranial haemorrhage reached a surprisingly high rate of 3.0% in the International Cooperative Pulmonary Embolism Registry of 2,454 prospectively evaluated acute pulmonary embolism patients at 52 hospitals in seven countries. An alternative approach to patients at high risk is a catheter-based or open surgical embolectomy. It is crucial to refer these patients as quickly as possible, rather than delaying intervention until cardiogenic shock has ensued. Fortunately the current tools for risk stratification provide an "early window" for prognostication and can help the coordination of a definitive treatment plan with optimal results.

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