A comparison of Power Doppler with conventional sonographic imaging for the evaluation of renal artery stenosis

BACKGROUND: Power Doppler (PD) has improved diagnostic capabilities of vascular sonography, mainly because it is independent from the angle of insonation. We evaluated this technique in a prospective comparison with conventional imaging, consisting in Duplex and Color Doppler, for the evaluation of Renal Artery (RA) stenosis. METHODS: Sensitivity, specificity and predictive values of PD and conventional imaging were assessed in a blinded fashion on eighteen patients, 9 with angiographic evidence of unilateral RA stenosis (hypertensive patients) and 9 with angiographically normal arteries (control group). PD images were interpreted with an angiography-like criteria. RESULTS: In the control group both techniques allowed correct visualization of 16 out of the 18 normal arteries (93% specificity). Only in five hypertensive patients RA stenosis was correctly identified with conventional technique (56% sensitivity and 86% negative predictive value); PD was successful in all hypertensive patients (100% sensitivity and negative predictive value), since the operators could obtain in each case of RA stenosis a sharp color signal of the whole vessel with a clear "minus" at the point of narrowing of the lumen. All results were statistically significant (p < 0.01). CONCLUSIONS: This study demonstrates that PD is superior to conventional imaging, in terms of sensitivity and specificity, for the diagnosis of RA stenosis, because it allows a clear visualization of the whole stenotic vascular lumen. Especially if it is used in concert with the other sonographic techniques, PD can enable a more accurate imaging of renovascular disease with results that seem comparable to selective angiography

Renal artery stenosis-when to screen, what to stent?

Renal artery stensosis (RAS) continues to be a problem for clinicians, with no clear consensus on how to investigate and assess the clinical significance of stenotic lesions and manage the findings. RAS caused by fibromuscular dysplasia is probably commoner than previously appreciated, should be actively looked for in younger hypertensive patients and can be managed successfully with angioplasty. Atheromatous RAS is associated with increased incidence of cardiovascular events and increased cardiovascular mortality, and is likely to be seen with increasing frequency. Evidence from large clinical trials has led clinicians away from recommending interventional revascularisation towards aggressive medical management. There is now interest in looking more closely at patient selection for intervention, with focus on intervening only in patients with the highest-risk presentations such as flash pulmonary oedema, rapidly declining renal function and severe resistant hypertension. The potential benefits in terms of improving hard cardiovascular outcomes may outweigh the risks of intervention in this group, and further research is needed

Stent-Graft Treatment of Patients with Acute Bleeding from Hepatic Artery Branches

To present a new treatment option in patients with acute bleeding from the hepatic artery branches.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41326/1/270_2004_Article_56.pd

Promoting Drp1-mediated mitochondrial fission in midlife prolongs healthy lifespan of Drosophila melanogaster

The accumulation of dysfunctional mitochondria has been implicated in aging, but a deeper understanding of mitochondrial dynamics and mitophagy during aging is missing. Here, we show that upregulating Drp1—a Dynamin-related protein that promotes mitochondrial fission—in midlife, prolongs Drosophila lifespan and healthspan. We find that short-term induction of Drp1, in midlife, is sufficient to improve organismal health and prolong lifespan, and observe a midlife shift toward a more elongated mitochondrial morphology, which is linked to the accumulation of dysfunctional mitochondria in aged flight muscle. Promoting Drp1-mediated mitochondrial fission, in midlife, facilitates mitophagy and improves both mitochondrial respiratory function and proteostasis in aged flies. Finally, we show that autophagy is required for the anti-aging effects of midlife Drp1-mediated mitochondrial fission. Our findings indicate that interventions that promote mitochondrial fission could delay the onset of pathology and mortality in mammals when applied in midlife

[Endovaskuläre Therapie der Nierenarterienstenose: Technische Ergebnisse mit dem Palmaz®-CorinthianTM-Stent]

Objective: To evaluate the technical performance and delivery characteristics of the Palmaz-Corinthian stent for endovascular therapy of atherosclerotic renovascular disease. Methods: 61 patients underwent implantation of 76 Palmaz-Corinthian (PC) stents in 72 arteries. 50 original PC and 26 PC stents with the modified IQ- design were employed. The indications comprised primary stenting of ostial (n=49) or truncal (n=1) stenosis or occlusion (n=3), and selective stenting following complicated (dissection, n=4) or unsuccessful (n=8) angioplasty. The remaining stents were placed in patients with recurrent stenosis (n=5) or acute aortic dissection (n=2) involving the renal artery. Mean severity and length of stenosis were 81,3% and 9.8 mm, respectively. 39 lesions were rated eccentric or calcified. Data on technical success, complication rate, delivery characteristics and ease of placement compared to standard renal stents were retrieved from a prospective multi-center registry. Results: Stent delivery was successful in all patients, major complications were not reported. Stent placement was suboptimal in 7 of 72 cases: 4 stents were located too distally in the renal artery, necessitating proximal coaxial overstenting in 2 cases. The distal part of the stenosis was incompletely covered and the orifice of a segmental branch inappropriately overstented in one case each. One stent was dislodged from the balloon, resulting in stent protrusion in the aortic lumen. Significnt residual stenosis after stenting was not observed. Overall stent deliverability, trackability and potential repositioning inside the stenosis were rated positive, radio-opacity was rated superior for the IQ design, Conclusion: Technical performance and delivery characteristics of the Palmaz-Corinthian stent have been significantly improved compared to the Palmaz design, allowing mostly correct placement in renal artery stenoses with a low complication rate

Early results of endovascular treatment of the thoracic aorta using the Valiant endograft.

Endovascular repair of the thoracic aorta has been adopted as the first-line therapy for much pathology. Initial results from the early-generation endografts have highlighted the potential of this technique. Newer-generation endografts have now been introduced into clinical practice and careful assessment of their performance should be mandatory. This study describes the initial experience with the Valiant endograft and makes comparisons with similar series documenting previous-generation endografts. Data were retrospectively collected on 180 patients treated with the Valiant endograft at seven European centers between March 2005 and October 2006. The patient cohort consisted of 66 patients with thoracic aneurysms, 22 with thoracoabdominal aneurysms, 19 with an acute aortic syndrome, 52 with aneurysmal degeneration of a chronic dissection, and 21 patients with traumatic aortic transection. The overall 30-day mortality for the series was 7.2%, with a stroke rate of 3.8% and a paraplegia rate of 3.3%. Subgroup analysis demonstrated that mortality differed significantly between different indications; thoracic aneurysms (6.1%), thoracoabdominal aneurysms (27.3%), acute aortic syndrome (10.5%), chronic dissections (1.9%), and acute transections (0%). Adjunctive surgical procedures were required in 63 patients, and 51% of patients had grafts deployed proximal to the left subclavian artery. Comparison with a series of earlier-generation grafts demonstrated a significant increase in complexity of procedure as assessed by graft implantation site, number of grafts and patient comorbidity. The data demonstrate acceptable results for a new-generation endograft in series of patients with diverse thoracic aortic pathology. Comparison of clinical outcomes between different endografts poses considerable challenges due to differing case complexity