Use of chronically occluded fistula to establish access outflow

Maintaining a good quality vascular access in the long term can become particularly challenging especially in patients that are on dialysis for many years and present with exhausted venous capital and chronic access related complications. We present a 60-year-old female patient with multiple bilateral previous failed accesses, a previous distal revascularization interval ligation (DRIL) for hemodialysis access induced distal ischemia (HAIDI). Her chronically (more than a month) occluded arteriovenous fistula AVF was used to establish outflow and create a functioning forearm arteriovenous graft (AVG).

The Impact of Seasonality on Prosthetic Arteriovenous Vascular Access Graft Thrombosis

Highlights Abstract Introduction: Arteriovenous prosthetic grafts are susceptible to recurrent thrombotic occlusions mainly due to venous outflow disease secondary to neointimal hyperplasia. Maintenance of vascular access for dialysis is a perpetual challenge for both patients and health care systems. In regions with hotter climates, there is a clinical impression that episodes of prosthetic arteriovenous vascular access graft thrombosis are more frequent during hot dry summers secondary to dehydration and increased blood viscosity. Seasonality of thrombotic events has been observed in multiple vascular beds. However, a seasonal pattern or any association of arteriovenous graft thrombosis with temperature and relative humidity levels has never been fully demonstrated. Methods: Data were collected prospectively from January 2014 until December 2020 but analyzed retrospectively. In this 7-year timeframe, 289 episodes of arteriovenous graft thrombosis were identified from 142 grafts fashioned. Results: No monthly variation (P = 0.35) or seasonal variation (P = 0.91) was identified. No statistically significant correlation between episodes of thrombosis and mean monthly temperature and mean relative humidity was noted. Conclusion: No evidence was identified to support this theory. However, multiple issues with assessments of events must be conceded. Graft thrombosis is multifactorial in nature, and venous outflow disease contributes toward a significant number of these events. Within our local cohort, a low primary patency rate was identified, which further contributes to graft interventions. Relatively small numbers were recruited, and therefore, potential correlations could have been missed.

Brachio-azygos transthoracic arteriovenous grafts for hemodialysis patients with bilateral central venous obstruction: A small case series

Background: It is difficult to find a reliable outflow vein for vascular access in hemodialysis patients with bilateral central venous obstruction. The lower extremity veins are currently used as the most common alternative veins to make a new vascular access. However, in patients not amenable to make lower extremity access, intrathoracic vein should be considered as an outflow vein, but there are limitations in its use due to postoperative complications. Methods: We introduce a series of cases that underwent arteriovenous graft operation using an intrathoracic vein, the azygos arch, as an outflow vein. Brachio-azygos transthoracic arteriovenous graft is a surgical procedure that anastomoses the azygos arch and the brachial artery with 7 mm ringed polytetrafluoroethylene graft via lateral thoracotomy without median sternotomy. Results: The chest tubes of the patients were removed on the third postoperative day and they discharged within a week. About 1 month later, hemodialysis was initiated through the BATAVG, and it has been used without access dysfunction. Conclusion: Brachio-azygos transthoracic arteriovenous grafts were performed using the azygos arches without major complications. The azygos arch can be a good alternative outflow vein to make a new vascular access for hemodialysis patients with bilateral central venous obstruction.

The role of venous pressure variability during hemodialysis in the prediction of impending arteriovenous graft occlusion

Background: Elevated venous pressure during hemodialysis (VPHD) is associated with arteriovenous graft (AVG) stenosis. This study investigated the role of VPHD variations in the prediction of impending AVG occlusion. Methods: Data were retrieved from 118 operations to treat AVG occlusion (occlusion group) and 149 operations to treat significant AVG stenosis (stenosis group). In addition to analyzing the VPHD values for the three hemodialysis (HD) sessions prior to the intervention, VPHD values were normalized to mean blood pressure (MBP), blood flow rate (BFR), BFR × MBP, and BFR2 × MBP to yield ratios for analysis. The coefficient of variation (CV) was used to measure relative variations. Results: The within-group comparisons for both groups revealed no significant differences in the VPHD mean and CV values among the three HD sessions prior to intervention. However, the CVs for VPHD/MBP, VPHD/(BFR × MBP), and VPHD/(BFR2 × MBP) exhibited significant elevation in the occlusion group during the last HD session prior to intervention compared with both the penultimate and antepenultimate within-group HD data ( p < 0.05). In the receiver operating characteristic curve analysis, the CV for VPHD/(BFR2 × MBP) was the only parameter able to discriminate between the last and the penultimate HD outcomes ( p < 0.001). According to a multivariate analysis, after controlling for covariates, CV for VPHD/(BFR2 × MBP) >8.76% was associated with a higher risk of AVG thrombosis (odds ratio: 3.17, p < 0.001). Conclusions: Increasing the variation in VPHD/(BFR2 × MBP) may increase the probability of AVG occlusion.

Dialysis access graft occlusion with contrast and ultrasound guided thrombin injection for intractable arm edema and pseudoaneurysm

We present the case of a patient with a brachio-basilic graft forearm loop with intractable edema and thrombosed central veins. She showed up with an important edema after some effort and a previously thrombosed pseudoaneurysm with significant growth. She refused angioplasty treatment for central veins, the graft had not been used for dialysis during the last year, so that arteriovenous graft (AVG) ligation was considered. Due to local conditions thrombin percutaneous embolization was performed to avoid possible complications of a conventional surgery approach. AVG occlusion was done in 10 min by fluoroscopy and ultrasound guidance. In 24 h the patient was significantly better and after 1 week she had no edema at all. There were no complications and no recanalization was observed after 3 months. Percutaneous thrombin embolization is a safe and effective technique for AVG occlusion in case of intractable arm edema with central vein thrombosis, and most likely to be considered in other situations where arteriovenous graft or fistula ligature is needed.

A Case of Brachial Artery Thrombosis Caused by Massage of an Occluded Arteriovenous Graft

Background: Acute upper limb ischemia (AULI) is a potential complication associated with massages of occluded vascular accesses in patients undergoing hemodialysis. Pharmacological thrombolysis, endovascular intervention and surgical intervention are possible treatment options. Deciding the appropriate treatment strategy is still a controversial issue. Case Presentation: The patient was a 43-year-old woman with renal failure who underwent hemodialysis and peritoneal dialysis. She was found to have an arteriovenous graft (AVG) thrombosis at the start of a hemodialysis session. She underwent massage of the vascular access, and immediately after the massage, she reported pain and cyanosis in her right-hand fingers and was referred to our hospital. Duplex ultrasonography revealed a large number of thrombi in the brachial, radial and ulnar arteries. AULI due to brachial artery thrombosis was diagnosed and surgical intervention was performed on the same day. The vascular wall of the forearm artery was incised vertically against the running vessel and thrombi around the bifurcation of the radial and ulnar arteries were removed. Angiography guided-surgical intervention was performed and improvement in blood flow was achieved. The patient was discharged on the second day after the operation. Conclusion: Surgical intervention has been reported as an effective treatment of AULI due to brachial artery thrombosis after massage of an occluded vascular access.

Hemodynamic Analysis on the Anastomosis Angle in Arteriovenous Graft Using Multiphase Blood Model

Numerical analysis was performed for the effect of the venous anastomosis angle in a forearm arteriovenous graft for hemodialysis using a multiphase blood model. The geometry of the blood vessel was generated based on the patient-computed tomography data. The anastomosis angles were set at 15°, 30°, and 45°. The hematocrit was set at 34%, 45%, and 58%. The larger anastomosis angle, high wall shear stress area >11 Pa, increases to the side of the vein wall away from the anastomosis site. Further, the relatively low wall shear stress area, <3 Pa, occurs near the anastomosis site in larger anastomosis angles. Therefore, the effect of high wall shear stress has advantages in the vicinity of the anastomosis, as the anastomosis angle is larger, but disadvantages as the distance from the anastomosis increases. Moreover, patients with low hematocrit are advantageous for WSS area.