Is intra-operative blood flow predictive for early failure of radiocephalic arteriovenous fistula?

Background. For over 50 years, radiocephalic wrist arteriovenous fistulae (RCAVF) have been the primary and best vascular access for haemodialysis. Nevertheless, early failure due to thrombosis or non-maturation is a major complication resulting in their abandonment. This prospective study was designed to investigate the predictive value of intra-operative blood flow on early failure of primary RCAVF before the first effective dialysis. Methods. We enrolled patients undergoing creation of primary RCAVF for haemodialysis based on the pre-operative ultrasound vascular mapping discussed in a multidisciplinary approach. Intra-operative blood flow measurement was systematically performed once the anastomosis had been completed using a transit-time ultrasonic flowmeter. During the follow-up, blood flow was estimated by colour flow ultrasound at various intervals. Any events related to the RCAVF were recorded. Results. Autogenous RCAVFs (n = 58) in 58 patients were constructed and followed up for an average of 30 days. Thrombosis and non-maturation occurred in eight (14%) and four (7%) patients, respectively. The intra-operative blood flow in functioning RCAVFs was significantly higher compared to non-functioning RCAVFs (230 vs 98 mL/min; P = 0.007), as well as 1 week (753 vs 228 mL/min; P = 0.0008) and 4 weeks (915 vs 245 mL/min, P < 0.0001) later. Blood flow volume measurements with a cut-off value of 120 mL/min had a sensitivity of 67%, specificity of 75% and positive predictive value of 91%. Conclusions. Blood flow <120 mL has a good predictive value for early failure in RCAVF. During the procedure, this cut-off value may be used to select appropriately which RCAVF should be investigated in the operation theatre in order to correct in real time any abnormalit

Long-term follow-up of surgically excluded popliteal artery aneurysms with multi-slice CT angiography and Doppler ultrasound

The purpose of this study was to evaluate the role of multi-slice computed tomography (MSCT) angiography in the follow-up of popliteal artery aneurysms (PAAs) that have been operated on. Aneurysm exclusion and progression, graft patency and graft-related complications were analyzed. Fourteen patients with 21 surgically excluded PAAs were evaluated with MSCT angiography with slice thickness of 1.25mm. The mean follow-up time was 67 months. MSCT demonstrated blood flow in six non-excluded PAAs (24%), with an average increase in the diameter of 21mm over time. Fifteen PAAs demonstrated no blood flow and revealed an average decrease of 7mm in diameter. The origin of this residual perfusion was demonstrated, and collaterals were involved in five of six non-excluded PAAs. In addition, MSCT demonstrated three graft stenoses. Furthermore, two occluded grafts were visualized. Twenty-four percent of the patients after surgical exclusion of PAAs revealed residual perfusion within the aneurysmal sac during follow-up, with a significant increase in the aneurysmal size with MSCT. Moreover, evaluation of the graft patency could also be done as could demonstration of anastomotic abnormalities. Thus, MSCT might be considered as a new tool to evaluate residual collateral feeding of popliteal aneurysmal sac and could be useful in identification and localization of feeding vessel

Systematic hybrid laparoscopic and endovascular treatment of median arcuate ligament syndrome: A single-center experience

BackgroundMedian arcuate ligament syndrome (MALS) is caused by celiac trunk (CT) compression by the median arcuate ligament. Clinically, this pathology varies from postprandial pain (Dunbar syndrome) to a life-threatening hemorrhage because of a rupture of a gastroduodenal artery aneurysm (GAA). Due to the low prevalence of this disease, there is no standard management for MALS.Material and methodThis was a single-center, retrospective study of 13 patients. Two groups were identified on the basis of the initial clinical presentation: those operated for a GAA rupture (bleeding group—BG) and those operated electively for Dunbar syndrome (Dunbar syndrome group—DG). The primary endpoint was 30-day postoperative complications of a systematic laparoscopic release of the median arcuate ligament and stenting during the same procedure.ResultsSeven patients (54%) underwent elective surgery. Six patients (46%) underwent semiurgent repair under elective conditions post-embolization for GAA bleeding. The total operative time was longer in the BG (p = 0.06). Two patients in the BG suffered early major complications and needed reintervention, and those in the DG had a lower comprehensive complication index. No mortality was reported at 30 days. Overall median length of stay was 5 days (IQR: 3.5–15.3). Patients in the DG had a significantly shorter length of stay (p = 0.02). At 6 months, the primary and secondary CT stent patencies were 82% and 100%, respectively. There were no high-flow GAA recurrences.ConclusionsA combined approach of laparoscopic release of the median arcuate ligament and stenting during the same procedure is feasible and safe, and this approach must be systematically discussed in symptomatic patients

Blood CXCR3(+) CD4 T Cells Are Enriched in Inducible Replication Competent HIV in Aviremic Antiretroviral Therapy-Treated Individuals

We recently demonstrated that lymph nodes (LNs) PD-1+/T follicular helper (Tfh) cells from antiretroviral therapy (ART)-treated HIV-infected individuals were enriched in cells containing replication competent virus. However, the distribution of cells containing inducible replication competent virus has been only partially elucidated in blood memory CD4 T-cell populations including the Tfh cell counterpart circulating in blood (cTfh). In this context, we have investigated the distribution of (1) total HIV-infected cells and (2) cells containing replication competent and infectious virus within various blood and LN memory CD4 T-cell populations of conventional antiretroviral therapy (cART)-treated HIV-infected individuals. In the present study, we show that blood CXCR3-expressing memory CD4 T cells are enriched in cells containing inducible replication competent virus and contributed the most to the total pool of cells containing replication competent and infectious virus in blood. Interestingly, subsequent proviral sequence analysis did not indicate virus compartmentalization between blood and LN CD4 T-cell populations, suggesting dynamic interchanges between the two compartments. We then investi-gated whether the composition of blood HIV reservoir may reflect the polarization of LN CD4 T cells at the time of reservoir seeding and showed that LN PD-1+ CD4 T cells of viremic untreated HIV-infected individuals expressed significantly higher levels of CXCR3 as compared to CCR4 and/or CCR6, suggesting that blood CXCR3-expressing CD4 T cells may originate from LN PD-1+ CD4 T cells. Taken together, these results indicate that blood CXCR3-expressing CD4 T cells represent the major blood compartment con-taining inducible replication competent virus in treated aviremic HIV-infected individuals

Amino Acid Restriction Triggers Angiogenesis via GCN2/ATF4 Regulation of VEGF and H2S Production

Angiogenesis, the formation of new blood vessels by endothelial cells (ECs), is an adaptive response to oxygen/nutrient deprivation orchestrated by vascular endothelial growth factor (VEGF) upon ischemia or exercise. Hypoxia is the best-understood trigger of VEGF expression via the transcription factor HIF1 alpha. Nutrient deprivation is inseparable from hypoxia during ischemia, yet its role in angiogenesis is poorly characterized. Here, we identified sulfur amino acid restriction as a proangiogenic trigger, promoting increased VEGF expression, migration and sprouting in ECs in vitro, and increased capillary density in mouse skeletal muscle in vivo via the GCN2/ATF4 amino acid starvation response pathway independent of hypoxia or HIF1 alpha. We also identified a requirement for cystathionine-gamma-lyase in VEGF-dependent angiogenesis via increased hydrogen sulfide (H2S) production. H2S mediated its proangiogenic effects in part by inhibiting mitochondrial electron transport and oxidative phosphorylation, resulting in increased glucose uptake and glycolytic ATP production.11Ysciescopu

Inhibition du développement de l'hyperplasie intimale par la rapamycine sur un modèle de culture de veine humaine

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