Postintervention Primary Patency Rates Research Articles

The feasibility of a novel method to remove circumferentially ruptured balloons during ultrasound-guided percutaneous transluminal angioplasty for arteriovenous dialysis access

Objective: Angioplasty balloon rupture is a rare complication during percutaneous transluminal angioplasty (PTA). Conventional approach to retrieve circumferentially ruptured balloons is open surgery. This study examined the feasibility of a novel approach which can remove ruptured balloon during PTA in vascular access. Methods: This retrospective study analyzed 35 patients of a total 6465 patients that underwent ultrasound-guided PTA with a circumferential balloon rupture from February 2016 and August 2023. The patients underwent surgery (Group I, n = 13) or the novel method (Group II, n = 22) for balloon retrieval. Kaplan–Meier curve was used to assess the primary patency rates of the two groups. Result: The total incidence of circumferential balloon rupture was 0.5% in our center. Balloon retrieval was successful in both groups with no complications except one case had an infection in the surgical wound. Kaplan–Meier curve analysis showed that the post-intervention primary patency rates of the two methods were not significantly different ( p > 0.05). There was a significant difference between pre-operation and post-operation brachial arterial flow ( p < 0.001). Conclusion: The feasibility of the novel technique for retrieval of circumferential ruptured balloons during ultrasound-guided PTA is validated. The technique enables less invasive retrieval and continuation of PTA.

#1664 Assessing vascular access thrombectomy service adherence to GIRFT recommendations: single centre experience

Abstract Background and Aims Studies showed that early thrombectomy of dialysis vascular access (VA) is associated with better outcomes [1], especially for native VA [2]. Timely treatment of VA thrombosis within 24-48 hours is recommended by GIRFT to minimize access loss and requirement for dialysis line insertion [3]. Our centre has approximately 430 HD patients but has no on-site vascular surgery or vascular access interventional radiology (IR) service. Wait time for elective VA surgery or fistuloplasty is >8 weeks and VA surveillance is based on routine clinical monitoring. VA prevalence is 62% AV fistula (AVF), 2% AV graft (AVG), 36% central venous catheter (CVC). Fistula thrombectomy is provided at another centre, with increasing waiting times over recent years due to shortage of interventional radiologists. This study evaluates adherence to GIRFT recommendations for patients at our centre requiring thrombectomy and will identify potential local strategies to reduce fistula thrombosis and CVC use. Method In a 24-months’ retrospective cohort analysis of maintenance HD patients with permanent VA, we obtained data on: Results 44 patients with permanent VA developed VA thrombosis. The median waiting time for thrombectomy was 8 days (Fig. 1). Post-intervention primary patency rate was 71% at 3-months and 60% at 6-months (Fig. 2). 61% of patients required hospital admission with a 12-day median length of stay, with total inpatient admission days of 403 days over 2 years (2022-2023), and total cost of £246,065 (Figs. 3 and 4). The median CFD-extended was 356 days, i.e. 9 days/patient/year with VA-related complications (Fig. 5). Conclusion This study shows that our centre's VA thrombectomy service falls far outside the GIRFT recommendation of intervention within 24-48 hours. The high associated rates of CVC use, inpatient bed days and avoidable costs place a heavy burden on patient outcomes and NHS resources. The ideal solution of an on-site thrombectomy service is difficult to achieve due to lack of vascular IR support. In response to this study, we now aim to reduce thrombosis rates by training additional interventional nephrologists in elective fistuloplasty, implementing a robust VA surveillance to improve early detection of malfunctioning VA suitable for elective intervention and improving staff education on fistula care.

#2559 “Remote software technology to assist clinical decision in vascular access surveillance: single UK centre experience”

Abstract Background and Aims Optimal arteriovenous access monitoring and surveillance aims for early detection of dysfunctional access, enabling pre-emptive referral for angioplasty or surgery to prevent access loss or thrombosis. Here we compared the addition of remote software surveillance to standard clinical care in our units. Method From January–December 2023 we conducted a 12-month prospective study of maintenance hemodialysis (HD) patients. We used Vasc-Alert software technology to assist clinical decision making for vascular access (VA) surveillance in 2 out of 5 HD units. In these units, vascular access risk score was calculated using Vasc-Alert software platform from routinely collected data from the dialysis procedure as previously described [1]. Patients with high Vasc-Alert access risk score (≥7) underwent clinical assessment and were referred for fistulogram if they met the relevant KDOQI criteria [2]. The following variables were collected from all 5 HD units: baseline permanent VA prevalence, subsequent VA events (stenosis or thrombosis), access abandonment (i.e. unsalvageable access loss), complication free days (CFD)-extended over one year (defined as days without serious vascular access events, radiological or surgical intervention, VA infection, hospitalisation or use of central venous catheter). Data was collected on patients who were pre-emptively referred for diagnostic fistulogram ± angioplasty but thrombosed while awaiting intervention. Median time interval from the date of fistulogram request till the date of confirmed thrombosed access was calculated. Comparison between HD units with Vasc-Alert use (Group 1) or without (Group 2) was performed using appropriate statistical tests depending on the type and distribution of the data. Survival analysis of post-intervention primary patency rate was conducted at 3 and 6 months defined as the time from the index procedure until the next access thrombosis or reintervention [3]. Results There were 81 (53.6%) patients with permanent VA in group 1and 201 (59.3%) patients in group 2at the start of the study. We recorded 23 (28.4%) episodes of stenosis and 6 (7.4%) episodes of thrombosis in Group 1 and 40 (19.9%) episodes of stenosis and 21 (10.4%) episodes of thrombosis in Group 2 (p value 0.121 and 0.432, respectively). In Group 2, 11 patients (5.5%) developed repeated stenosis and 2 patients (1%) repeated thrombosis. In Group 1, 5 /6 (83%) cases preemptively referred for diagnostic fistulogram ± angioplasty developed thrombosis whilst awaiting elective intervention, compared with 4/21 (19%) in group 2 (p value = 0.008) (Fig. 1). The median time interval from the date of fistulogram request till date of thrombosed VA was 26 days with Interquartile range (IQR 25-75%) of 21-34 days. Group 1 had better post-intervention primary patency rate of VA (Fig. 2) and longer CFD-extended compared to group 2 (p values < 0.001 and 0.002 respectively) (Table 1). Conclusion Our study shows that integrating Vasc-Alert technology into the VA surveillance program was associated with improved early detection of high-risk access, higher primary patency rates and CFD-extended. Additionally, our data emphasizes the need to enhance interventional radiology capacity for timely access intervention, to realise the true potential of Vasc-Alert technology in prevent access thrombosis.

Efficacy of drug-coated balloon catheters for patients with short-term recurrent dysfunction of arteriovenous fistula.

In this study, we aimed at clarifying the usefulness of drug-coated balloon catheters (DCBs) for arteriovenous fistulas (AVFs) that repeatedly undergo restenosis over a short period and to examine the factors that influence the patency period after DCB use. This retrospective observational study was conducted using IN.PACT AV in 29 cases of AVFs with repeated restenosis within approximately 3 months, and temporary patency before and after DCB use in the same patients was compared. For target participants, the flow volume, resistive index (RI), and vascular diameter of the brachial artery were measured using an ultrasound diagnostic device. Stenosis diameter, reference vessel diameter, and stenosis length of the lesion were measured before and after DCB dilatation using digital subtraction angiography. Before DCB angioplasty, the postintervention primary patency at 3 months was 66%, and the average interval was 92 ± 21 days (mean ± standard deviation). After DCB angioplasty, the postintervention primary patency rates at 3 and 6 months were 92% and 36%, respectively. The postintervention primary patency was significantly higher after than before DCB angioplasty (p < 0.0001). A sub-analysis was performed on 25 patients who were followed up for 4 months or more after DCB. The RI values before and after dilatation with DCB significantly differed between the patency group 4 or more months after DCB and the patency group less than 4 months after DCB. For AVFs that require frequent PTA over a short period of time, DCB improved the patency rate 3 months after PTA, but the improvement effect at 6 months was limited. The effect of DCB on prolonging the patency rate of AVFs that require frequent PTA over a short period of time may be correlated with the RI value before and after PTA.

Factors affecting the primary patency of native arteriovenous fistulas after ultrasound-guided percutaneous transluminal angioplasty

Objective By analyzing the clinical history, laboratory test indexes, and intraoperative ultrasound imaging data of patients receiving ultrasound-guided percutaneous transluminal angioplasty (UG-PTA) for the first time, the application value of UG-PTA in the treatment of peripheral stenosis of autogenous arteriovenous fistula (AVF) and the related factors affecting postoperative patency were investigated. Methods A total of 381 patients with dysfunction of radio-cephalic AVF were treated with UG-PTA from June 2017 to September 2019. According to the inclusion and exclusion criteria, 199 patients were included in this study. Baseline characteristics of patients, including demographic, clinical, and laboratory data, were collected. Kaplan–Meier’s survival curve was used to demonstrate the cumulative primary patency rate of UG-PTA. Univariate and multivariate Cox regression analysis was performed on clinical, anatomic, biochemical, and medication variables to identify the predictors of postintervention primary patency. Results The early technical success rate of UG-PTA was 98.4% (375/381). One hundred and ninety-nine patients, with an average age of 52.9 years, were analyzed, 97 of whom were males (48.7%). The median follow-up duration was 21 months. No major complication was observed. Postintervention primary patency rates were 87.7%, 75.8%, and 60.0% at 6, 12, and 24 months, respectively. A previously failed AVF (HR, 1.935, 95% CI 1.071–3.494; p = .029) and an increased level of parathyroid hormone (HR per 100 pg/mL increase, 1.105; 95% CI 1.014–1.203; p = .004) were identified as independent negative predictors of primary patency of UG-PTA. Conclusions UG-PTA is a safe and effective method for the treatment of peripheral stenosis of AVF. Previously failed AVF and elevated parathyroid hormone levels are associated with lower primary patency rate.

Comparison of percutaneous transluminal angioplasty and surgical revision after intraoperative dilatation with biliary tract probes for arteriovenous fistula stenosis at juxta-anastomosis.

Percutaneous transluminal angioplasty (PTA) is widely used for stenosis of vascular access (VA) for hemodialysis. We aimed to evaluate the effectiveness of both PTA and surgical revision after intraoperative dilatation with biliary tract probes for juxta-anastomotic stenosis in autogenous radiocephalic arteriovenous fistulas (RCAVFs). We performed a retrospective analysis of PTA and surgical revision after intraoperative dilatation with biliary tract probes; these were the first interventions after RCAVF establishment in 112 patients with juxta-anastomotic stenosis. Anatomical (number of stenoses) and clinical variables (age and gender of the patient, time of hemodialysis, AVF age, presence of diabetes mellitus, and cause of end-stage renal disease) were reviewed. Technical success, clinical success, and post-intervention primary patency were evaluated. Our study enrolled 35 patients in the PTA group and 77 patients in the surgical revision group. Clinical and technical success rates of both groups were 100%. There were no complications, such as bleeding or hematomas. Using the Kaplan-Meier method, the post-intervention primary patency rates at 3, 6, 9, 12, 18, and 24months in the PTA group were 100%, 94.28%, 77.1%, 60%, 54.29%, and 45.71%, respectively, and those in the surgical revision group were 100%, 94.81%, 92.2%, 90.91%, 81.82%, and 76.62%, respectively. The post-intervention primary patency rates at 9-24months in the surgical revision group were significantly higher than those in the PTA group (χ2 = 19.04, p < 0.0001). The post-intervention long-term primary patency rate of surgical revision after intraoperative dilatation with biliary tract probes is higher than that of PTA for the first intervention of patients with juxta-anastomotic stenosis in RCAVFs. The surgical revision method is safe and effective, especially in hospitals that have not yet carried out PTA.

The related factors to the re-thrombosis of hemodialysis arteriovenous graft after endovascular salvage.

Only a few issues of the related factors to hemodialysis access dysfunction have been evaluated, and the effects of antiplatelets to improve the patency of hemodialysis access remained controversial. Hence, this study aimed to determine the related factors to the re-thrombosis of arteriovenous grafts (AVGs) after endovascular treatment. This retrospective study was conducted at a university-affiliated teaching hospital in Southern Thailand. All patients who underwent hemodialysis with thrombosed AVG, who had pharmacomechanical thrombolysis from January 2016 to December 2018, were enrolled. Post-intervention primary patency was analyzed by the Kaplan-Meier method, and the related factors to the re-thrombosis of AVG were evaluated using logistic regression. A total of 157 patients with thrombosed hemodialysis AVG were enrolled. The most common graft location and configuration was a forearm loop graft (65%). Post-intervention primary patency rate at 1, 3, and 6 months were 79.0%, 67.1%, and 54.0%, respectively. Diabetes mellitus (DM) was a significant related factor for re-thrombosis (hazard ratio [HR], 1.89; 95% confidence interval [CI], 1.20-2.98; p = 0.006). A single antiplatelet after the procedure was a protective factor for re-thrombosis (HR, 0.58; 95% CI, 0.38-0.89; p = 0.013). The median post-intervention primary patency was 15.7 months in the group of single antiplatelet usage, which was better than that of the non-antiplatelet group (p = 0.012). DM and antiplatelet usage were significant related factors to the re-thrombosis of hemodialysis AVG after endovascular salvage.

Cleaner XT Rotational Thrombectomy: An Efficacious Endovascular Technique for Salvage of Thrombosed Arteriovenous Access and a 12 Month Outcome Analysis

Purpose: This study aims to describe an efficacious method using Cleaner XT rotational thrombectomy with catheter-directed thrombolysis and drug-eluting balloon angioplasty for the salvage of thrombosed arteriovenous fistulae and grafts. Materials and Methods: Retrospective analysis of all patients with thrombosed hemodialysis accesses who underwent endovascular salvage using the Cleaner XT rotational thrombectomy system at a single institution between June 2019 and September 2020 was performed. Patency was presented as Kaplan-Meier survival curves, and regression analysis was performed to examine predictors of postintervention primary patency and assisted primary patency based on Cox proportional-hazards model. Results: Thirty-four patients with thrombosed accesses underwent Cleaner XT rotational thrombectomy between June 2019 and September 2020. Technical and clinical success were both 100%. Mean procedure time was 62 ± 20 minutes. Mean postintervention primary patency time was 152 ± 51 days; 30, 90, 180, and 365 day postintervention primary patency rates were 89%, 80%, 68%, and 56%, respectively. Mean postintervention-assisted primary patency time was 157 ± 59 days; 30, 90, 180, and 365 day postintervention-assisted primary patency rates were 91%, 82%, 71%, and 59%, and 180 and 365 day secondary patency rates were 97.2% and 94.4%, respectively. Conclusion: The Cleaner XT rotational thrombectomy device demonstrates excellent clinical and technical success rates, with good patency results at all time points up to 12 months postintervention.

Outcomes of endovascular treatment for stenosis occurring after cephalic vein transposition and graft interposition

ObjectiveTo evaluate the outcome of endovascular treatment after surgical treatment for cephalic arch stenosis (CAS) in the brachiocephalic fistula (BCF) and to analyze the factors influencing patency. MethodsWe conducted a retrospective review of patients undergoing cephalic vein transposition (CVT) or graft interposition (GIP) for CAS from January 1, 2017, to December 31, 2019. A total of 73 patients with restenosis were included in this study. Patients were classified into cephalic transposition (BCF-CVT) (n = 49) and graft interposition (BCF-GIP) (n = 24) groups. We calculated the postintervention primary and secondary patency of endovascular treatment by using the Kaplan-Meier analysis and analyzed variables associated with loss of postintervention patency. ResultsSix-month and 12-month postintervention primary patency rates of endovascular treatment for restenosis were 56.7% and 15.6% and secondary patency rates were 89.7% and 72.1%, respectively. In the BCF-CVT group, 6-month and 12-month postintervention primary patency was 56.8% and 17.6% and secondary patency was 93.3% and 79.4%, respectively. In the BCF-GIP group, 6-month and 12-month postintervention primary patency was 56.5% and 8.7% and secondary patency was 85.7% and 56.3%, respectively. There was no significant difference in postintervention primary patency between the two groups (P = .79). However, the BCF-CVT group demonstrated higher postintervention secondary patency (P = .034). The BCF-GIP group had a higher number of stenosis sites (P < .01). There was no significant predictor of reduced postintervention primary patency. The only adverse variable of postintervention secondary patency was BCF-GIP (hazard ratio, 3.14; 95% CI, 1.06-9.34; P < .05). ConclusionsEndovascular treatment is still the acceptable option for stenosis occurring after surgical treatment for CAS. CVT provides higher postintervention secondary patency than GIP.

Endovascular treatment of nonfunctional vascular access through retrograde arterial access: A single-center experience with midterm follow-up

Background/Aim: Nonfunctional vascular access is treated through venous or brachial artery access traditionally. However, each route has its drawbacks. This study aimed to evaluate the feasibility, safety, and effectiveness of retrograde arterial access (RAA) in the treatment of nonfunctional vascular access with mid-term results. Methods: Patients with nonfunctional vascular access who were treated through RAA between January 2019 and December 2020 were included in this cohort study. Patient demographics, lesion characteristics, procedural details, technical and clinical outcomes were noted. Results: Thirty-six interventions were performed on 30 patients. Twenty-nine occlusions and seven long segment stenoses were treated. The radial artery was accessed in 34 cases, the interosseous and ulnar arteries were accessed in one case each. The technical and clinical success rates were 100% and 97.2%, respectively (35/36). Venous rupture was encountered in three patients. No puncture-site complication was observed. The mean follow-up time was 14.3 (range: 6-24) months. None of the patients showed signs of hand ischemia and the accessed arteries were patent at Color Doppler Ultrasound examinations. Post-intervention primary patency rates were 100%, 73.3%, 47.5% at 1, 6 and 12 months, respectively. Post-intervention secondary patency rates were 100%, 93.3%, 84.8% at 1, 6 and 12 months, respectively. Conclusion: RAA is effective and safe in the treatment of nonfunctional vascular access with comparable outcomes to traditional routes. The low access-site complication rates make this access site an attractive salvage route when traditional approaches are not feasible.

Comparison of Clinical Outcomes in Patients Undergoing a Salvage Procedure for Thrombosed Hemodialysis Arteriovenous Grafts.

BackgroundThe major limitation of arteriovenous graft access is the high incidence of thrombotic occlusion. This study investigated the outcomes of our salvage strategy for thrombosed hemodialysis arteriovenous grafts (including surgical thrombectomy with balloon angioplasty) and evaluated the efficacy of intragraft curettage.MethodsSalvage operations were performed for 290 thrombotic occluded arteriovenous grafts with clinical stenotic lesions from 2010 to 2018. Of these, 117 grafts received surgical thrombectomy and balloon angioplasty from 2010 to 2012 (group A), and 173 grafts received surgical thrombectomy and balloon angioplasty, with an additional salvage procedure using a curette and a graft thrombectomy catheter, from 2013 to 2018 (group B). Outcomes were described in terms of post-intervention primary patency and secondary patency rates.ResultsThe post-intervention primary patency rates in groups A and B were 44.2% and 66.1% at 6 months and 23.0% and 38.3% at 12 months, respectively (p=0.003). The post-intervention secondary patency rates were 87.6% and 92.6% at 6 months and 79.7% and 85.0% at 12 months, respectively (p=0.623). Multivariate Cox regression analysis demonstrated that intragraft curettage was a positive predictor of post-intervention primary patency (hazard ratio, 0.700; 95% confidence interval, 0.519–0.943; p=0.019).ConclusionSurgical thrombectomy and balloon angioplasty showed acceptable outcomes concerning post-intervention primary and secondary patency rates. Additionally, intragraft curettage may offer better patency to salvage thrombotic occluded arteriovenous grafts with intragraft stenosis.

Sharp Needle Recanalization Technique for Peripheral Hemodialysis Arteriovenous Fistula Occlusion.

To determine the efficacy of a percutaneous sharp needle recanalization technique for the treatment of peripheral hemodialysis arteriovenous fistula (AVF) occlusion. This study included 13 patients (14 procedures) between May 2010 and February 2020 with non-thrombotic AVF occlusion wherein guidewire passage through the occluded segment had failed. We successfully passed the guidewire through the occluded segment using a sharp needle recanalization technique with Chiba or Colapinto needles, under ultrasound or fluoroscopic guidance. The type of AVF, site and length of occlusion, technical success, complications, and long-term patency were analyzed. Technical success was achieved in 12 (85.7%) out of 14 procedures. The procedure failed in two patients due to the poor angle of approach in the axillary area and diffuse severe stenosis in the draining cephalic vein. In eight procedures, sharp needle recanalization was performed under ultrasound guidance, while the other six procedures were performed under fluoroscopic guidance. Chiba and Colapinto needles were used in five and nine procedures, respectively. The mean length of occlusion was 2.7cm (range 1.8-4.2cm). There was one case of mild complication, that is, mild contrast extravasation, which was treated by stent deployment. The post-intervention primary patency rates at 6months, 1year, and 2years were 81.8%, 36.4%, and 18.2%, respectively. The results of this limited series suggest that the sharp needle recanalization technique is a simple and effective method for the treatment of peripheral non-thrombotic AVF occlusion.

Efficacy of ultrasound-guided percutaneous transluminal angioplasty for arteriovenous fistula stenosis or occlusion at juxta-anastomosis: A 3-year follow-up cohort study

ObjectiveArteriovenous fistula (AVF) is the preferred access for hemodialysis. Percutaneous transluminal angioplasty (PTA) has become a choice for AVF stenosis, and ultrasound has been used in PTA more frequently. MethodsThis single-center retrospective cohort study analyzed 129 patients who underwent PTA in the First Affiliated Hospital of Chongqing Medical University from January 2016 to December 2016. Angioplasty was performed using a noncompliant high-pressure balloon. The process was visualized by duplex scan. Our inclusion criteria were as follows: (1) stenoses or occlusions were located at the juxta-anastomosis site: the first 5 cm of the vein distal to the anastomosis; (2) stenosis was confirmed with the following conditions: (a) flow rates are <500 mL/min in the brachial artery and <200 mL/min in the fistula during dialysis, and (b) the stenosis diameter is <1.7 mm. We used the Kaplan-Meier curve to show the postintervention primary and secondary patency rates of patients with stenosis and occlusion. ResultsAltogether, 129 patients with 76 males were analyzed. Moreover, 104 have AVFs on the left arm, and only one patient had an ulnar-basilic AVF, whereas others had a radial-cephalic AVF. The postintervention primary patency rates are better in occlusion cases (P < .05), whereas secondary patency rates have no difference. The postintervention primary patency rates are better in patients without diabetes mellitus (P < .05), whereas the secondary patency rates had no difference. ConclusionsFor juxta-anastomosis site stenosis or occlusion, PTA can be used to obtain satisfactory results.

The usefulness and feasibility of placing a clinch knot with a guidewire to achieve temporary hemostasis in arteriovenous dialysis access interventions.

To evaluate the usefulness and feasibility of using a reversible clinch knot with a guidewire in place rather than eliminating the access route during an arteriovenous hemodialysis access (AV access) intervention using the facing sheath technique. From July 2016 to June 2019, we retrospectively studied 78 sessions performed as interventional treatment for arteriovenous (AV) hemodialysis (HD) access using the "facing-sheath technique." In all sessions, all antegrade sheaths were removed while a 0.035-inch guidewire remained in place with purse-string suture and the clinch knot. Seventy-two sessions were performed in patients with thrombosed AV accesses (69 arteriovenous grafts [AVGs] and three arteriovenous fistulas [AVFs]), and six sessions were carried out to treat non-thrombosed AV accesses (four AVGs and two AVFs). We evaluated whether proper hemostasis and successful reinsertion of the sheath over the wire into the clinch knot was achieved. Clinical success was defined as achieving prompt restoration of blood flow for AV access, and the postintervention primary and secondary patency were also evaluated. In all 87 clinch knots created in 78 total sessions, proper hemostasis was achieved. All clinch knots that required reversal for additional procedures were successfully reopened (55 clinch knots in 50 sessions). The postintervention primary patency rates at 1, 3, and 6 months, and at 1 year were 77.8%, 68.9%, 55.6%, and 33.3%, respectively. The postintervention secondary patency rates at 1, 3, and 6 months, and also at 1 year were 93.3%, 91.1%, 86.7%, and 86.7%, respectively. Our AV access intervention which used a clinch knot with purse-string suture while the guidewire remained in place was both useful and feasible for maintaining temporary hemostasis.

Comparison between endovascular versus hybrid thrombectomy for arteriovenous graft under complete ultrasound guidance.

Endovascular treatment of acute thrombosed arteriovenous grafts performed completely under ultrasound guidance has rarely been reported. We compared the efficacy of a new endovascular thrombectomy technique (percutaneous manual thromboaspiration through the introducer sheath) with classical hybrid thrombectomy (minimally invasive surgical thrombectomy combined with high-pressure angioplasty) performed completely under ultrasound guidance, for arteriovenous graft thrombosis. This was a retrospective cohort study involving patients receiving hemodialysis who underwent arteriovenous graft thrombectomy between January 2014 and December 2017. We divided 130 participants into an intervention (endovascular) group (N.=65) and a control (classical hybrid) group (N.=65) according to the thrombectomy technique. The procedural success rate, immediate outcomes and patency were compared between the groups. There was no significant difference in the procedural success rate (92.31% vs. 89.23%, P=0.55) between the intervention and control groups, respectively. No major complications were noted, but two cases of vessel rupture occurred in the control group and three cases of vessel rupture occurred in the intervention group. The procedure time in the intervention group was significantly shorter than that in the control group (74±14.21 min vs. 109.05±19.20 min, respectively; P<0.05). During the 6-month follow-up, we found no significant difference in the postintervention primary patency rate (48.33% vs. 55.17%; P=0.51) or the postintervention second patency rate (83.33% vs. 84.49%; P=0.79) between the intervention and control groups, respectively. Dialysis clearance and ≥50% stenosis were predictors of postintervention primary patency (hazard ratio, 7.80; 95% confidence interval: 1.75-34.81; P=0.01; and hazard ratio, 6.43; 95% confidence interval: 2.43-17.03; P<0.001), respectively. Completely ultrasound-guided percutaneous manual thromboaspiration through the introducer sheath can be used for thrombosed arteriovenous grafts. This approach has the advantage of shorter operative time compared with hybrid treatment.

Factors affecting patency of arteriovenous fistula following first percutaneous transluminal angioplasty.

Percutaneous transluminal angioplasty (PTA) has generally replaced surgical procedures to treat arteriovenous fistula (AVF) dysfunction, but the predictors of post-intervention patency are highly variable. This study aimed to determine predictors of primary patency following PTA of dysfunctional AVF. Retrospective analysis of first-time PTA of 307 AVF in 307 patients (171 males, mean age 64.3 ± 12.4years). Demographic, clinical, anatomical and medication variables were reviewed and subjected to univariate and multivariate Cox regression analysis. The post-intervention primary patency rates at 6, 12, 24, and 36months were 76.3%, 58.3%, 43.2%, and 38.2%, respectively. The higher aortic arch calcification (AAC) grade patients were older, had higher incidence of comorbidities and cardiomegaly, and younger AVF age, but their dialysis vintage term was shorter and diastolic blood pressure was lower, and the maximum diameter of balloon angioplasty was mostly ≤ 6mm, and had lower phosphorus level and less calcium-containing phosphate binder use. In multivariate Cox proportional hazard analysis, the presence of higher AAC grade [hazard ratio (95% confidence interval): (1.46 (1.02-2.09); p = 0.037)] and stenosis at upper arm [1.76 (1.16-2.67); p = 0.008] were associated with shorter post-intervention primary patency. In conclusion, higher AAC grade and anatomic factor related to the location of AVF (upper arm) were the important predictors of AVF dysfunction after PTA. These results could assist in tailoring surveillance programs and performing appropriate interventions for risky AVF.

Factors influencing outcomes of rheolytic thrombectomy on thrombosed dialysis access grafts: Door to angiographic bed time and what else?

The aim of this study was to investigate the effect of the time interval from clinical presentation of arteriovenous graft thrombosis and the thrombectomy procedure by the AngioJet system in terms of technical and clinical success and to identify factors influencing success. A total of 60 consecutive patients (35 men and 25 women; mean age = 52 ± 7.89 years) who had undergone percutaneous thrombectomy by the AngioJet device from 2016 to 2019 were retrospectively enrolled. Demographics and fistula data, previous treatments, time from clinical onset of thrombosis to intervention, procedural details and complications were recorded. Technical and clinical success and primary and secondary patency rates were calculated. One-way analysis of variance was performed to test any correlation between patient-related and fistula/procedure-related variables and technical/clinical success. Odds ratio and relative risk were also calculated when necessary. Technical success and clinical success were 95% and 91.7%, respectively. Post-interventional primary and secondary patency rates at 1 year were 72.5% and 84.3%, respectively. Complication rate was 6.7%. One-way analysis of variance showed that clinical success was higher in patients with no previous treatment (p = 0.015). Furthermore, clinical success was significantly associated with door to angiographic bed time (p = 0.002): p-value for the 24-h and the 72-h cut-off was 0.012 and 0.006, respectively. Percutaneous rheolytic thrombectomy is safe and effective for thrombosed arteriovenous grafts, with acceptable primary and secondary patency rates. Higher clinical success was found in patients never treated before and when the procedure was carried out within 24 h from the clinical onset of thrombosis.

Stent graft deployment in haemodialysis fistula: patency rates in partially thrombosed aneurysm and residual thrombi.

BackgroundCurrent evidence is insufficient to determine the contribution of stent grafts as treatment in partially thrombosed aneurysms or residual wall-adherent thrombi in arteriovenous fistulae (AVFs) for haemodialysis. The overall purpose of this study was to analyse patency rates of post-interventional covered stent deployment in those cases. We also assessed if patency rates differed when fistulas were punctured through the stent during dialysis sessions. MethodsWe conducted a retrospective study between 2006 and 2014 analysing post-intervention primary patency rates using the Kaplan–Meier log-rank test. Multivariate Cox proportional regression models were performed to determine if cannulation within the stent graft area was a potential risk factor for occlusion, by adjusted hazard ratio (HR).ResultsA total of 27 procedures were included in the study. Primary patency rates (%) after stent deployment at 3, 6, 12, 24, 36 and 72 months were, respectively: total 59, 32, 32, 21, 11 and 5; stent puncture 53, 21, 21, 16, 5 and 0; and no stent puncture 80, 80, 80, 40, 40 and 40. Cannulation through the stent graft was not significantly associated with increased risk of obstruction in multivariate analysis (HR = 3.01; P = 0.286).ConclusionStent graft treatment may be a feasible procedure in partially thrombosed aneurysms and residual thrombi in AVF. Although fistulas punctured through the stent presented lower patency rates, this practice was not associated with a higher risk of obstruction. Giving the impossibility of comparing with similar approaches, further studies are needed to confirm or refute the advantages of this procedure.

A randomized feasibility study of the effect of ascorbic acid on post-angioplasty restenosis of hemodialysis vascular access (NCT03524846)

Restenosis remains a significant problem after angioplasty of hemodialysis vascular access. Both experimental and clinical studies have shown a protective effect of antioxidants against post-angioplasty restenosis. A prospective, randomized, feasibility study was conducted to investigate the effect of ascorbic acid to prevent restenosis. Ninety-three hemodialysis patients were randomized into three groups after angioplasty: placebo (n = 31), 300 mg ascorbic acid (n = 31), and 600 mg ascorbic acid (n = 31), treated intravenously 3 times per week for 3 months. Eighty-nine completed the clinical follow-up, and 81 had angiographic follow-up. In the angiographic follow-up, the mean (stand deviation) late loss of luminal diameter for the placebo, 300 mg, and 600 mg groups were 3.15 (1.68) mm, 2.52 (1.70) mm (P = 0.39 vs. placebo group), and 1.59 (1.67) mm (P = 0.006, vs. placebo group), with corresponding angiographic binary restenosis of 79%, 67% (P = 0.38 vs. placebo group), and 54% (P = 0.08 vs. placebo group). The post-interventional primary patency rates at 3 months were 47%, 55% (P = 0.59 vs. placebo group), and 70% (P = 0.18 vs. placebo group) for placebo, 300 mg, and 600 mg groups. Our results demonstrated that intravenous 600 mg ascorbic acid was a feasible therapy and might attenuate restenosis after angioplasty; however, its effect on post-interventional primary patency was modest.

Percutaneous transluminal angioplasty combined with thrombolysis for acute thrombosis in arterio-venous fistula and graft

To evaluate the efficacy of ultrasound or fluoroscopic-guided percutaneous transluminal angioplasty (PTA) combined with thrombolysis for the treatment of acutely thrombosed arteriovenous fistula (AVF) or grafts (AVG). One hundred and ninety-two hemodialysed patients, in whom the thrombosed arterio-venous AVF or AVG developed less than 72 h and there were no contraindications for thrombolysis and PTA, underwent PTA combined with thrombolysis therapy in Sir Run Run Shaw Hospital of Zhejiang University from October 2014 to October 2017. Under ultrasound and/or fluoroscopic guidance, balloon catheter was introduced to thrombosis sites along a guide wire. Then the balloon was inflated and normal saline mixed with urokinase and heparin was injected for thrombolysis. After blood flow was restored, angioplasty was performed on vascular stenosed sites. A total of 274 endovascular interventional operations were performed for 192 patients. The procedure success rate was 98.2%, clinical success rate was 93.8%and complication rate was 1.46%. The post-intervention primary patency rates for AVF group were 87.4%, 76.7%and 63.9%at 3, 6 and 12 months, respectively; while the post-intervention secondary patency rates were 93.7%, 91.6%and 83.0%, respectively. The post-intervention primary patency rates for AVG group were 60.7%, 51.5%and 43.1%at 3, 6 and 12 months, while the post-intervention secondary patency rates were 82.7%, 77.1%and 70.8%, respectively. PTA combined with thrombolysis is an effective and safe therapeutic option for AVF and AVG thrombosis, which would prolong hemodialysis access and save vascular resources for hemodialyzed patients.