Fluid Dynamics of Single-needle Dialysis in an Experimental Model

Background:Acceptance has grown for single-needle dialysis when a vascular access is not suited for the insertion of two needles. Its impact on flow patterns was unknown. Methods:We produced transparent life-size models of arteriovenous(AV)fistulas and AV grafts that we placed into a pulsatile flow system to examine flow characteristics during simulated dialysis cycles. For this purpose we injected dye, and recorded and analyzed the resulting flow patterns using suitable software tools. Results:There is a definite flow reversal during the arterial phases in both AV fistulas and -less pronounced-in AV grafts leading to flow oscillations. Conclusion:Flow oscillations initiate subintimal hyperplasia possibly leading to stenoses in vivo. Reversal of the flow direction may also cause steal phenomena in the poorly perfused distal extremity. Single-needle dialysis should therefore be avoided if possible

Aortic Valve Replacement in Anomalous Aortic Origin of Right Coronary Artery

A 75-year-old man with severe aortic regurgitation was referred to our department for surgery. Coronary angiography revealed 75% stenosis at left coronary artery( LAD) and a normally positioned left coronary artery. However, the location of the right coronary artery was anomalous. The right coronary artery ostium originated from the ascending aorta above the left coronary cusp. Emergency surgery proceeded to address severe dyspnea due to congestive heart failure. The higher portion of the right coronary artery was incised in sigmoid fashion, the aortic valve was replaced with a 23-mm stented bioprosthesis and coronary bypass grafting proceeded. The postoperative course was uneventful

Hemolytic Anemia soon after Replacement of Ascending Aorta for acute Aortic Dissection

A 61-year-old female underwent replacement of the ascending aorta for Type A aortic dissection, then gradually developed severe hemolytic anemia over 1 month. The cause of hemolysis was found to be mechanical damage of red blood cells caused by an inverted felt strip at the proximal anastomosis. A reoperation for resection of the felt and repair of the proximal anastomosis successfully resolved the problem. Here, we report a rare case of hemolytic anemia at the site of an inverted felt strip that occurred after replacement of the ascending aorta

Modified Bentall operation with bioprosthetic valve and Valsalva graft conduit:the "slit skirt" technique

We elucidated the efficacy of the slit skirt technique to prevent bleeding from the proximal anastomosis between the graft and aortic annulus. Between September 2008 and September 2014, 15 patients underwent a modified Bentall operation with the slit skirt technique at our institution. No patients had bleeding from the proximal anastomosis. No re-thoracotomy for bleeding was required. During midterm follow-up (median period, 21 months), no patient had pseudoaneurysms at the proximal suture line. We conclude that the slit skirt technique is useful to prevent bleeding from the proximal anastomosis after the Bentall operation

Molecular Mechanism of the Urate-lowering Effects of Calcium Channel Blockers

Hyperuricemia has recently been recognized as one of the risk factors for cardiovascular diseases. Some calcium channel blockers(CCBs), commonly used in the treatment of hypertension, have been reported to decrease serum urate level. Here, we tried to elucidate the molecular mechanism of the urate-lowering effects of CCBs. We performed [^C]urate uptake in cells stably expressing human urate transporter 1, a major contributor of renal urate reabsorption and a major target of uricosuric drugs such as benzbromarone and losartan(HEK-URAT1), together with mock(HEK-mock)cells to analyze the uricosuric action of CCBs. We also measured the activity of human xanthine oxidase(XO)to determine whether CCBs have inhibitory effects on urate production. The CCBs tested were nifedipine, nilvadipine, nitrendipine, benidipine, nisoldipine, nicardipine, efonidipine, amlodipine, azelnidipine, verapamil and diltiazem. We found for the first time that at least seven CCBs in the dihydropyridine subgroup interacted with URAT1-mediated urate uptake in HEK-URAT1 cells. Among these CCBs, nifedipine, nilvadipine and nitrendipine strongly inhibited URAT1-mediated urate uptake. Their IC_s were 15.8, 0.018 and 0.40?μM, respectively. In contrast, urate production mediated by XO was weakly inhibited by nifedipine and nisoldipine. In summary, URAT1 interacted with various CCBs differently, whereas XO, a major enzyme for urate production in the liver, did not interact with most of CCBs. Although CCBs were not excreted from the urine basically, their urate-lowering effects may be associated with the inhibition of renal urate reabsorption mediated by renal urate transporters such as URAT1 with their metabolites, and the results for structure-activity information in this study will provide a clue for developing new uricosuric drugs targeting URAT1

An assessment of the cost-effectiveness of magnetic resonance, including diffusion-weighted imaging in patients with transient ischaemic attack and minor stroke : a systematic review, meta-analysis and economic evaluation

Erratum issued September 2015 Erratum DOI: 10.3310/hta18270-c201509Peer reviewedPublisher PD

Aortoesophageal fistula involving the central aortic arch salvaged with emergent percutaneous TEVAR, great vessel coverage and in vivo graft fenestration

Immediate intervention is needed for aortoesophageal fistulas (AEF), a rare but highly lethal cause of massive gastrointestinal hemorrhage. Emergent thoracic endovascular aortic repair (TEVAR) is considered first-line treatment for massive bleeding from AEFs. We describe an unusual and challenging case of TEVAR coverage of an AEF involving the central aortic arch immediately followed by in vivo endograft fenestration to regain arch vessel perfusion. In vivo fenestration, currently a procedure for emergency or investigational purposes only, was shown to be life saving in our case. The main complications associated with the procedure included stroke and infection, requiring esophagectomy and cervical diversion as well as ongoing antibiotic treatment