Distal hypoperfusion ischemic syndrome (DHIS), commonly referred to as hand ischemia or “steal” after dialysis access placement, occurs in 5–10% of cases when the brachial artery is used, or 10 times that of wrist arteriovenous fistulas (AVFs) using the radial artery. It is typically seen in elderly women with diabetes, and may carry severe morbidity including tissue or limb loss if not recognized and treated. Three distinct etiologies include (1) blood flow restriction to the hand from arterial occlusive disease either proximal or distal to the AV access anastomosis, (2) excess blood flow through the AV fistula conduit (true steal), and (3) lack of vascular (arterial) adaptation or collateral flow reserve (ie atherosclerosis) to the increased flow demand from the AV conduit. These three causes of steal may occur alone or in concert. The diagnosis of steal is based on an accurate history and physical examination and confirmed with tests including an arteriogram, duplex Doppler ultrasound (DDU) evaluation with finger pressures and waveform analysis. Treatment of steal includes observation of developing symptoms in mild cases. Balloon angioplasty is the appropriate intervention for an arterial stenosis. At least three distinct surgical corrective procedures exist to counteract the pathophysiology of steal. The ultimate treatment strategy depends on severity of symptoms, the extent of patient co-morbidity, and the local dialysis access technical team support and skills available.
Background. There are controversial data about vascular access stenosis surveillance by ultrasonography. The definition of stenosis significance varies among centres. We performed a retrospective study to describe short-term outcomes of borderline asymptomatic stenoses defined by precise criteria and to determine possible risk factors of stenosis progression. Methods. We studied the outcome of borderline stenoses in accesses with PTFE grafts. Stenosis was considered significant if there was a combination of >50% lumen reduction and peak systolic ratio >2, together with at least one of the following additional criteria: (1) residual diameter 25% or actual flow volume <600 ml/min. Stenosis was considered borderline in the absence of the additional criteria. Results. Of the 102 borderline stenoses, after 11 ± 6 weeks, 55 remained non-progressive, in 38 the degree of the stenosis progressed, in 8 a percutaneous transluminal angioplasty (PTA) was performed due to clinical indication and only 1 thrombosed. A significant relative risk of developing significant stenosis was found in grafts with prior PTA [RR = 1.91 (95% CI: 1.27, 2.88), P = 0.002] and in female gender [RR = 2.29, (95% CI: 1.29, 4.06), P = 0.025]. Conclusions. Delaying PTA of borderline stenoses is safe using this watch-and-wait strategy and stenoses remain stable over at least short time, but with higher risk of progression especially after prior PTA. We believe that the definition of precise criteria of stenosis significance is necessary for the benefit of ultrasound surveillance.
Purpose: Patency of mature vascular access for hemodialysis is mostly limited by the growing stenoses leading to acute access thrombosis. The therapy of choice is usually percutaneous balloon angioplasty (PTA). However, PTA injures the vessel wall and subsequent re-stenosis develops faster than de novo stenosis. Therefore, the key is in appropriate timing of PTA procedures – as late as possible but before access thrombosis develops. Ultrasonography combines the morphologic and functional access assessment, but the former is less precise than angiography. The aim of this study was to compare ultrasonographic and angiographic measuring of residual diameter as the additional criterion of significant stenoses used in our center. Methods: Residual diameter of significant stenoses was measured by B-mode ultrasonography three times in 20 patients. All the patients were indicated for angiography and the residual diameter of the stenoses was re-analyzed by this method. The repeatability of ultrasonographic residual diameter measurements and reproducibility in comparison to angiography were expressed by coefficients of variation (CV). Results: The residual diameter was 1.69 ± 0.05 mm by ultrasound and 1.65 ± 0.59 mm measured by angiography. In the ultrasound repeatability study, CV was 3.17 ± 2.76% and in the reproducibility study CV was 18.0 ± 15.6%. All the stenoses found to be significant by ultrasound were above 65% by angiography and PTA was performed. Conclusions: Ultrasonographic measurement of the residual diameter is stable in experienced hands and is well comparable to angiography results. These findings advocate residual diameter of 2.0 mm as the strong additional criterion of the significant stenoses, which can also be used in ultrasound surveillance of arteriovenous grafts.
1 July 2021 in International Journal of Cardiology
Patients on chronic haemodialysis have a wide range of changes in cardiac function and structure, including left ventricular hypertrophy, dilation and diastolic dysfunction or pulmonary hypertension. All these changes were linked to increased mortality in previous studies. High-flow arteriovenous fistulas (AVF) are supposed to be a factor contributing to their development. This study investigated the early effect of surgical AVF blood flow (Qa) reduction on these changes in patients with or without heart failure changes. Forty-two patients in chronic haemodialysis programme with high-flow AVF (Qa over 1500 mL/min), indicated for surgery for ≥1 of the following indications: 1.manifest heart failure; 2.hand ischemia; 3.advanced structural heart changes detected by echocardiography. The patients underwent echocardiography on selection visit, before blood flow reducing surgery and six weeks thereafter. The Qa reduction led to decrease of left ventricular mass (p = 0.02), end-diastolic volume (p = 0.008), end-diastolic diameter (p = 0.003) and left atrial volume (p = 0.0006). Diastolic function improved. Similarly, right ventricular diameter and right atrial volume decreased (p = 0.000001 and 0.00009, respectively) together with the decrease of estimated pulmonary artery systolic pressure. 81% of patients suffered from pulmonary hypertension prior to surgery, only 36% thereafter. The surgical restriction of the hyperkinetic circulation leads to several improvements of heart structure and function, which was linked to higher mortality in other studies. The beneficial effect of Qa reduction is present even in patients without symptoms of heart failure. The contribution of AVF must be considered with structural or functional heart changes.
We aimed to evaluate cardiovascular (CV) risk in patients with idiopathic inflammatory myopathies (IIM) compared with healthy controls (HC) and to assess its association with disease-specific features. Ninety IIM patients and 180 age-/sex-matched HC were included. Subjects with a history of CV disease (angina pectoris, myocardial infarction and cerebrovascular/peripheral arterial vascular events) were excluded. All participants were prospectively recruited and underwent examinations of carotid intima–media thickness (CIMT), pulse wave velocity (PWV), ankle-brachial index (ABI), and body composition. The risk of fatal CV events was evaluated by the Systematic COronary Risk Evaluation (SCORE) and its modifications. Compared with HC, IIM patients had a significantly higher prevalence of traditional CV risk factors, carotid artery disease (CARD), abnormal ABI and PWV. After propensity score matching (using traditional CV risk factors), the prevalence of CARD and pathological PWV remained significantly higher in IIM than HC. No significant difference in SCORE was observed. The most unfavourable CV risk profile was observed in patients with necrotizing myopathy, especially in statin-induced anti-HMGCR+ patients. The calculated CV risk scores by SCORE, SCORE2 and SCORE multiplied by the coefficient 1.5 (mSCORE) were reclassified according to CIMT and the presence of carotid plaques. SCORE was demonstrated to be most inaccurate in predicting CV risk in IIM. Age, disease activity, lipid profile, body composition parameters and blood pressure were the most significant predictors of CV risk in IIM patients. Significantly higher prevalence of traditional risk factors and subclinical atherosclerosis was observed in IIM patients compared with HC.