Inflow stenoses in dysfunctional hemodialysis access fistulae and grafts.

BACKGROUND: The aim of the study is to prospectively determine the incidence of inflow stenoses in dysfunctional hemodialysis access arteriovenous fistulae (AVFs) and grafts (AVGs). METHODS: Contrast-enhanced magnetic resonance angiography (CE-MRA) was performed of 66 dysfunctional AVFs and 35 AVGs in 56 men and 45 women (mean age, 62 years; age range, 31 to 86 years). Complete inflow (from the subclavian artery), shunt region, and complete outflow (including subclavian vein) were shown at CE-MRA. In addition to standard digital subtraction angiography (DSA) of the shunt region and outflow, DSA of the complete inflow was obtained through access catheterization of all cases in which CE-MRA showed an inflow stenosis. Vascular stenosis is defined as greater than 50% decrease in luminal diameter compared with an uninvolved vascular segment located adjacent to the stenosis. Endovascular intervention of stenoses was performed in connection with DSA. RESULTS: CE-MRA showed 19 arterial stenoses in 14 patients (14%). DSA confirmed 18 of these lesions in 13 patients and showed no additional inflow lesions. Of the 13 patients, 7 patients had arterial stenoses only and 6 patients had accompanying stenoses in the shunt region and/or outflow. Referral criteria for the 13 patients to undergo access evaluation had been decreased flow rates (9 patients), steal symptoms (2 patients), and insufficient access maturation (2 patients). Access flow of the 9 patients with a low-flow access improved from 477 +/- 74 mL/min to 825 +/- 199 mL/min after angioplasty. One patient with steal symptoms became symptom free after angioplasty. Endovascular intervention in 3 patients proved to be unsuccessful. CONCLUSION: Inflow stenoses are not uncommon in dysfunctional hemodialysis access shunts. We suggest that radiological evaluation comprise assessment of the complete arterial inflow.

Low-intensity pulsed ultrasound (LIPUS) in fresh clavicle fractures: a multi-centre double blind randomised controlled trial.

BACKGROUND: Several randomised trials have been published on the effect of low-intensity pulsed ultrasound (LIPUS) on fracture healing in both distal radius and tibia fractures. Most studies showed a positive effect on time to clinical and radiological healing. We hypothesised that LIPUS has a beneficial effect on the healing of fresh clavicle fractures as well and studied its effect in non-operatively treated shaft fractures. METHODS: We conducted a randomised double blind, placebo-controlled multi-centre trial in 101 adult patients with a non-operatively treated fresh clavicle shaft fracture. Of these patients, 49 used a placebo transducer and 52 patients had an active transducer with ultrasound stimulation (Exogen 2000). Data were analysed on intention to treat basis. Baseline parameters of both groups were not significantly different. RESULTS: There were no differences in time to subjective clinical fracture healing, resumption of daily activities, sports or professional work, Visual Analogue pain Scores (VAS) and use of pain medication. CONCLUSION: Our findings did not confirm that LIPUS accelerates clinical healing time of fresh clavicle shaft fractures. LEVEL OF EVIDENCE: Level 1 evidence that low-intensity pulsed ultrasound does not accelerate clinical fracture healing in non-operatively treated fresh midshaft clavicle fractures.

Outpatient treatment of arterial inflow stenoses of dysfunctional hemodialysis access fistulas by retrograde venous access puncture and catheterization.

OBJECTIVE: To determine the feasibility of endovascular treatment of inflow stenoses in arteriovenous fistulae (AVFs) through retrograde venous access catheterization. METHODS: We included all 22 dysfunctional AVFs with arterial inflow stenoses at access imaging between January 2002 and September 2006. Following retrograde venous access puncture, an interventional radiologist intended to cross the arteriovenous anastomosis and advance a catheter into the aortic arch. After depiction of the complete vascular access tree, angioplasty and/or stent placement was aimed for stenoses with a >50% luminal diameter reduction at digital subtraction angiography (DSA). RESULTS: In one radiocephalic AVF, a catheter could not be positioned into the aortic arch after retrograde venous access puncture. DSA depicted 28 inflow stenoses in the remaining 21 patients (11 radiocephalic AVFs and 10 brachiocephalic AVFs). Clinical improvement was obtained in 18 out of 19 patients with a technically successful intervention (<30% residual stenosis after angioplasty or stent placement). Following endovascular therapy, access flow of 12 patients with a low flow access improved from 431 +/- 150 ml/min to 818 +/- 233 ml/min, and four patients with steal symptoms became symptom free. One nonmaturing fistula could be salvaged by angioplasty, and access cannulation problems were solved in another patient following angioplasty. Brachial artery stent placement did not reduce steal symptoms in one case, whereas two patients, in whom stent placement was not thought desirable, showed a >30% residual arterial stenosis after angioplasty. No complications were observed at DSA and endovascular intervention. CONCLUSION: Retrograde venous access puncture and catheterization, as an alternative to a potentially more hazardous brachial artery or more invasive femoral artery approach, should be considered for the visualization of the arterial inflow and endovascular treatment of inflow stenoses.