Immature Arteriovenous Fistula Research Articles

Cathepsin G promotes arteriovenous fistula maturation by positively regulating the MMP2/MMP9 pathway

Background Arteriovenous fistula (AVF) is currently the preferred vascular access for hemodialysis patients. However, the low maturation rate of AVF severely affects its use in patients. A more comprehensive understanding and study of the mechanisms of AVF maturation is urgently needed. Methods and results In this study, we downloaded the publicly available datasets (GSE119296 and GSE220796) from the Gene Expression Omnibus (GEO) and merged them for subsequent analysis. We screened 84 differentially expressed genes (DEGs) and performed the functional enrichment analysis. Next, we integrated the results obtained from the degree algorithm provided by the Cytohubba plug-in, Molecular complex detection (MCODE) plug-in, weighted gene correlation network analysis (WGCNA), and Least absolute shrinkage and selection operator (LASSO) logistic regression. This integration allowed us to identify CTSG as a hub gene associated with AVF maturation. Through the literature search and Pearson’s correlation analysis, the genes matrix metalloproteinase 2 (MMP2) and MMP9 were identified as potential downstream effectors of CTSG. We then collected three immature clinical AVF vein samples and three mature samples and validated the expression of CTSG using immunohistochemistry (IHC) and double-immunofluorescence staining. The IHC results demonstrated a significant decrease in CTSG expression levels in the immature AVF vein samples compared to the mature samples. The results of double-immunofluorescence staining revealed that CTSG was expressed in both the intima and media of AVF veins. Moreover, the expression of CTSG in vascular smooth muscle cells (VSMCs) was significantly higher in the mature samples compared to the immature samples. The results of Masson’s trichrome and collagen I IHC staining demonstrated a higher extent of collagen deposition in the media of immature AVF veins compared to the mature. By constructing an in vitro CTSG overexpression model in VSMCs, we found that CTSG upregulated the expression of MMP2 and MMP9 while downregulating the expression of collagen I and collagen III. Furthermore, CTSG was found to inhibit VSMC migration. Conclusions CTSG may promote AVF maturation by stimulating the secretion of MMP2 and MMP9 from VSMCs and reducing the extent of medial fibrosis in AVF veins by inhibiting the secretion of collagen I and collagen III.

The efficacy of percutaneous transluminal angioplasty and arteriovenous fistula reconstruction for immature arteriovenous fistula

BackgroundTo access the efficacy of percutaneous transluminal angioplasty and arteriovenous fistula reconstruction for immature arteriovenous fistula, compare the long-term patency and post-operative complications between them.Materials and methodsThe medical records and Hemodialysis record sheets from 44 patients between May 2020 and January 2022 who underwent percutaneous transluminal angioplasty or arteriovenous fistula reconstruction treatment for immature autogenous arteriovenous fistula (AVF) were retrospectively reviewed. The patients were divided into two groups according to the type of surgery they received, including 25 patients in the PTA group and 19 patients in the AVF reconstruction group. Clinical outcomes were included, such as the primary and secondary patency rates following the procedure, maturation time, peak systolic velocity (PSV) of brachial artery, maximum pump-controlled blood flow at initial dialysis, and post-operative complications rates in the two groups.ResultsTechnical and clinical success was achieved in 100% of the 44 cases. For patients who underwent percutaneous transluminal angioplasty, the primary patency rate at 3, 6, and 9 months was 84.0%, 68.0%, 60.0%, and the secondary patency rate was 92.0%, 84.0%, 80.0%, respectively. And for patients who underwent arteriovenous fistula reconstruction, the primary patency rate at 3, 6, and 9 months was 89.5%, 73.7%, 68.4%, and the secondary patency rate was 100.0%, 94.7%, 94.7%, respectively. There were no significant differences between the two groups in terms of patency rates (p > .050). In patients whose maturation was successful, the average maturation time of fistula after the PTA procedure was 19.36 ± 13.94 days, and 58.63 ± 18.95 days for the reconstruction procedure (p < .010). The PSV of brachial artery before and after the procedure was 87.64 ± 23.87 cm/s and 153.20 ± 21.69 cm/s in PTA group, for reconstruction group, the number was 86.26 ± 20.59 cm/s and 151.26 ± 29.94 cm/s, respectively. No statistically significant differences (p > .050). The maximum pump-controlled blood flow at initial dialysis was 232.60 ± 16.72 ml/min in PTA group, which was significantly higher than 197.11 ± 10.45 ml/min in reconstruction group (p < .010). Subcutaneous hematoma, restenosis, thrombus formation, and pseudoaneurysm were major complications in PTA group. Restenosis, thrombus formation, and pseudoaneurysm were major complications in reconstruction group, with no statistically significant differences between the two groups (p > .050).ConclusionWhen immature AVFs require reconstruction surgery, the patency outcomes are comparable to AVFs that undergo successful management by PTA. While, when AVFs are successfully managed by PTA, they have significantly less maturation times and higher maximum pump-controlled blood flow rates at initial dialysis AVF use.

Possibility and predictors of surgical salvage of infected mature arteriovenous fistula for hemodialysis

Background Infection in arteriovenous fistula (AVF) is a common complication in patients with end-stage renal disease (ESRD) requiring dialysis. The standard management includes ligation of the AVF to prevent the progression of septicemia. Till now, there is limited evidence on the effectiveness and possibility of salvage of infected AVFs. Aim To evaluate the effectiveness and safety of salvage of infected mature autogenous AVF. Methods This prospective study was conducted at the Fayoum University Hospital from September 2015 to April 2023. We included patients with dysfunctional and functioning infected AVF. Patients with infected synthetic grafts and immature infected AVFs were excluded. We aimed to excise the infected part of the vein wall and surrounding tissues to restore fistula patent and functioning after direct vein repair. We followed-up with all patients for 1 year and examined the repaired AVFs for patency and the possibility of re-infection. Tissue cultures were obtained to identify the commonest responsible organism and the recommended antibiotics. Results A total of 46 patients with infected AVFs were included. At the end of the follow-up period, 11 patients were ligated, and 35 underwent AVF salvage procedures. 19 cases experienced some complications: 5 cases had hematoma required surgical intervention, 2 cases had hematoma managed conservatively, 2 patients had wound dehiscence, 3 patients required hybrid angioplasty for acute failed AVF, and 7 cases required angioplasty for failing AVF. Conclusion When performed correctly and with expert hands, salvage of infected mature AVFs seems possible with excellent efficacy and high patency for up to 1 year.

Correlation between preoperative Doppler ultrasonography-assessed specific accessory cephalic vein diameter-cephalic vein diameter ratio (r) and early dysfunction of Radial artery-Cephalic vein arteriovenous fistula: a single-center cross-sectional study.

Accessory cephalic vein (ACV) ligation can circumvent immature arteriovenous fistula (AVF). However, no consensus has been reached on the definite timing of ACV ligation. This study aimed to retrospectively analyze the correlation between preoperative Doppler ultrasonography (DUS)-assessed specific ACV diameter-cephalic vein diameter ratio (r) and early dysfunction of Radial artery-Cephalic vein (RC)-AVF in order to improve the early maturity rate of RC-AVF. A total of 258 patients who underwent RC-AVF at The Third Affiliated Hospital, Sun Yat-sen University from 1 June 2018 to 31 March 2022 were included in this study. The inclusion criteria were as follows: (I) cephalic vein ≥2.0 mm and radial artery ≥1.5 mm, suitable for RC-AVF establishment; (II) presence of an ACV. As per the specific r determined using preoperative DUS assessment, all patients were classified into two groups: Group A (r<0.8) and Group B (r≥0.8). Furthermore, patients in each group were divided into intervention and non-intervention subgroups based on the presence or absence of intraoperative ACV ligation, respectively. Patient data including age, sex, underlying disease, AVF side, and radial diameter were compared. The difference of maturity rate between participants in the intervention group and non-intervention group with different r values was analyzed, so as to obtain the relationship between different r values and maturity rate. No statistical differences were observed between the intervention and non-intervention subgroups in the two groups in terms of sex, age, comorbidities, complications, AVF side, radial artery, cephalic vein, and ACV diameters (P>0.05). When r<0.8, the maturity rates of the intervention group and the non-intervention group were 80% and 92.98%, respectively, χ2=4.561. The difference in maturation rate between the intervention and non-intervention subgroups was insignificant (P=0.075) when r<0.8. When r≥0.8, the maturity rates of the intervention group and the non-intervention group were 89.83% and 45.45%, respectively, χ2=25.943. The difference in maturation rates between the intervention and non-intervention subgroups was significant when r≥0.8 (P<0.001). Preoperative DUS suggested a correlation between r≥0.8 and early immaturity of RC-AVF. Therefore, concurrent intraoperative ACV ligation should be carried out when preoperative r is ≥0.8, as it may reduce the early power dysfunction of RC-AVF.

The effect of early conversion from central venous catheter to arteriovenous fistula on hospitalization and mortality in incident haemodialysis patients.

Controversy remains as to whether initiating haemodialysis (HD) with a central venous catheter (CVC) and vascular access conversion are associated with the risk of morbidity and mortality in incident HD patients. At our dialysis centre, the vascular access strategy is to create an arteriovenous fistula (AVF) early and use the AVF to initiate HD. In emergency situations, HD is initiated with a CVC and subsequent conversion from a CVC to an AVF as soon as possible. The effects of early AVF conversion on hospitalization and mortality were analysed. At HD initiation, 35.42% used AVF, 15.63% used CVC with immature AVF and 48.96% used CVC, and all patients were able to convert from CVC to AVF within approximately 3 months. Compared to starting HD using an AVF, using a CVC was associated with access-related hospitalizations at 2 years, regardless of whether an AVF was created before (incidence rate ratio (IRR) = 3.02, 95% CI 0.89-10.24, p = 0.03) or after (IRR = 4.10, 95% CI 1.55-10.85, p < 0.01) HD initiation. The Kaplan-Meier method showed that the 2-year survival probability was not statistically significant between the three groups (log-rank χ2 = 0.165, p = 0.921). Multivariate Cox proportional hazards regression showed that starting HD with a CVC was not associated with mortality at 2 years (p > 0.05). In this cohort, initiating HD with a CVC was associated with more access-related hospitalizations. Under the impact of an early AVF conversion strategy, despite initiating HD with a CVC, subsequent conversion from a CVC to an AVF within approximately 3 months had no impact on all-cause mortality in incident HD patients.

Artery-to-Fistula Diameter Ratio as a Predictor of Early Re-Occlusion of Immature Right Radio-Cephalic Arteriovenous Fistula after Primary PTA

Percutaneous transluminal angioplasty (PTA) is widely performed for arteriovenous fistula (AVF) that fails to mature after initial formation. We observed that some immature AVFs re-occlude earlier than others. We sought to investigate the predictors for early post-intervention failure of immature fistulas after primary PTA. We retrospectively reviewed the records and angiographic images of patients who had immature fistulas and thereby received PTA between 2013 and 2019 at our center. We investigated the short-term post-intervention outcomes of the patients within 90 days post-PTA. Patients who had re-occlusion within the period were defined as the early failure group and the rest as the patent group. We investigated factors associated with early failure. There were 80 eligible patients with 22 brachio-cephalic (BC) and 58 radio-cephalic (RC) AVFs. The median age of the patients was 64 years [range, 38–87]. There were 51 (63%) males and 29 (36%) females. Among the 58 RC AVFs, 10 (17%) patients had early failure. Logistic regression analysis showed that a larger artery to fistula (A/F) diameter ratio was the sole independent predictor of early failure after primary PTA (odd ratio 2.29 [1.023–5.147], p value = 0.044). Although further studies on a larger scale are required to confirm the clinical significance, a larger A/F diameter ratio was a potential predictor of early re-occlusion in immature fistulas after primary PTA.

Accessory Vein Obliteration and Balloon-Assisted Maturation for Immature Arteriovenous Fistulas for Haemodialysis: A Systematic Review and Meta-Analysis.

This study aims to examine outcomes of immature arteriovenous fistula salvage using balloon angioplasty (PTA) without and with accessory vein obliteration (PTA + VO). PubMed and Embase were accessed on 21 September 2020 to retrieve cohort studies on adult patients with end-stage renal failure (ESRF) requiring dialysis. Risk of bias was assessed using Newcastle-Ottawa Scale. Studies were pooled into PTA or PTA + VO arms, with outcomes (technical/clinical success, primary/secondary post-intervention patency until 12months) reported as event rates with 95% confidence intervals. Random-effects model and maximum likelihood meta-regression were used for meta-analysis. Fourteen studies (1030 participants) were included. The between-subgroup difference in outcomes was largely non-significant (p > 0.050). The evidence does not support balloon angioplasty with concomitant accessory vein obliteration for immature fistula salvage.

The clinical outcome of balloon-assisted maturation procedure between autogenous radiocephalic fistula and brachiocephalic fistula in a single-center experience

ObjectiveBalloon-assisted maturation (BAM) by an endovascular method plays an important role in treating an immature arteriovenous fistula. However, the results between radiocephalic fistula and brachiocephalic fistula were rarely reported. This retrospective study aimed to investigate the effectiveness and outcome of BAM in different sites of autogenous arteriovenous fistulas. MethodsThis single-center retrospective study included patients who underwent BAM procedures from January 2015 to December 2016. Of 148 patients, 117 and 31 patients had a radiocephalic fistula (RC) and a brachiocephalic fistula (BC), respectively. The primary outcome was BAM success. Data regarding fistula lesions, balloon types and size, frequency of procedures, and maturation time were collected for BAMs. The secondary outcome was the patency of a fistula in the follow-up period. ResultsNo difference was observed in procedure of BAM frequency between the RC and BC groups. The total success rate was 77.7%, without significant difference between the RC and BC groups (81.20% vs 64.50%; P = .055). Within the procedures, the culprit lesion of juxta-anastomosis segment (73.5% vs 25.5%; P < .001) and arterial inlet (21.2% vs 7.8%; P = .04) were more common in the RC group, whereas the venous outlet was more common in the BC group (88.2% vs 57.7%; P < .001). Both groups had an equivalent patency rate after the BAM within the follow-up period (P = .272). ConclusionsBAM was an effective procedure for immature fistulas, without significant difference between RCs and BCs. Through the procedure, the culprit lesions causing non-maturation were found to be different between the two groups. The patency rate between the two groups after surgery seems to be equivalent within the follow-up period.

Arteriovenous fistula formation with adjuvant endovascular maturation

BackgroundThe clinical utility of the native arteriovenous fistula (AVF) has been limited by the prolonged time required for maturation, the low overall maturation rate, and subsequent abandonment. Endovascular intervention has been increasingly accepted as the first-line therapy for AVF stenosis. The objective of the present study was to evaluate the AVF formation outcomes when early endovascular intervention was selectively performed to bring about timely AVF maturation. MethodsWe performed a retrospective study (February 2014 to February 2020) of 82 AVF consecutive patients (mean age, 62.5 ± 13.5 years; range, 17-83; 58 men [70.7%]) with end-stage renal failure who had undergone vascular access construction at a single institution. The 4-year AVF patency, vascular diameters, hemodialysis parameters, reintervention rate, and mortality were analyzed. ResultsRadiocephalic AVF was the most common fistula constructed (71 patients; 88.6%). The evaluation at a mean of 46.2 ± 56.0 days (range, 5-343 days) after AVF formation revealed 33 immature AVFs (40.2%). Subsequently, 19 patients had undergone endovascular procedures, including angioplasty and/or stenting of the juxta-anastomosis, cannulation zones, and/or outflow segments to bring about timely maturation of the AVF. Hence, 93.9% of the AVFs had reached functional patency (maturation) by 6 months after formation, with a mean time to maturation of 67.8 ± 65.9 days (range, 5-320 days). After reaching maturation, the primary access functional patency was 82% ± 4.3% at 6 months, 58% ± 5.5% at 12 months, and 34% ± 6.8% at 48 months. The primary assisted access functional patency was 95% ± 2.4% at 6 months, 90% ± 3.3% at 12 months, and 83% ± 4.7% at 48 months. A total of 121 endovascular interventions were performed to maintain patency, equating to an endovascular reintervention rate of 0.37 procedure/patient year. The mean arterial, venous, and brachial flow rates did not change significantly after maturation with a mean AVF (primary assisted functional patency) survival time of 5.9 ± 0.26 years (range, 5.33-6.36 years) from maturation. Only 12 thromboses had occurred after the first follow-up review after AVF formation. These were all salvaged using endovascular techniques, leading to 100% total secondary functional patency at 4 years. The 5-year estimated all-cause mortality was 45.6% ± 12.7%. ConclusionsThe AVF maturation rate and interval to maturation were improved when early endovascular intervention was selectively performed after AVF formation. This allowed for near universal maturation. In addition, once matured, the use of ongoing endovascular reinterventions allowed for a low reintervention rate and long-term patency, providing reliable long-term renal vascular access.

Long–Term Patency Post–Endovascular Salvage Procedure and the Influencing Factors

Background : One of the greatest challenges of hemodialysis is the limited durability of vascular access. Immature AVF is defined as AVF that never develops adequately to support dialysis. One of the causes that makes very often immature AVF is stenosis besides creation of the fistula itself. The EFS is a treatment modality for preemptive repair of immature AVF besides surgical revision. The purpose of this study is to evaluate EFS effectiveness in immature AVF and its influencing factors as there was no study of EFS in Indonesia with specific characteristics. Methods: A retrospective cohort study conducted on patients with immature AFV underwent EFS procedures during period of January 2016 to December 2016. The primary patency post EFS was assessed in correlation to subjects’ characteristics, anatomical variations, diabetes mellitus, and the length and diameter of balloon to post EFS patency. Results : There were 125 stenosis found, 66 stenosis in juxta anastomosis. The average length of stenosis is 33.18 mm. On the study we found age, diabetes mellitus, length of stenosis and multiple stenosis were the factors that influence the primary patency. The length of stenosis was the most variable influencing on 6 months primary patency (p <0.001), with a cutoff point of the diameter at 35 mm. Multiple stenosis (p <0.001) was the most important factor influencing on 12 months primary patency. The length and diameter balloon were not influencing the primary patency on 6 months and 12 months. Overall primary patency were 69.3% and 38.6% on 6 months and 12 months respectively Conclusion : EFS procedures on immature AVF may be used as the first method of choice in treatment compared to new AVF creation or revision in surgical fashion. Keywords : endovascular salvage fistula, immature arteriovenous fistula, percutaneous transluminal angioplasty.

Outcome of endovascular salvage of immature hemodialysis arteriovenous fistulas.

To assess the causes of immature hemodialysis arteriovenous fistula and the outcome of endovascular salvage. The outcome of 207 endovascular salvage procedures in 139 patients after the first successful cannulation was analyzed retrospectively from January 2011 to December 2017 in the Catholic University of Korea, Seoul St. Mary's Hospital. Of the 139 patients aged 62 ± 13 years, 45% were women, 59% had diabetes, and 71% were maintained on hemodialysis using central venous catheters. Mean interval between arteriovenous fistula creation and referral to angiography was 87 ± 63 days. While inflow stenosis (54.4%) was the most common cause of immature forearm fistulas (n = 76), both inflow (38.6%) and mixed stenosis (35.1%) were the main causes of immature upper arm fistulas (n = 63). Endovascular salvage procedures included percutaneous transluminal angioplasty (n = 174) and accessory vein obliteration (n = 30). The overall technical and clinical success rates were 97% and 93.4%, respectively. Mean interval between endovascular procedure and the first successful cannulation of the fistula was 28 ± 35 days. At 3, 6, and 12 months following the first successful cannulation, the primary patency rates were 81%, 69.5%, and 57.6%, respectively, and the secondary patency rates were 97.2%, 96%, and 94.8%, respectively. Mixed stenosis was the only determinant of secondary patency rate of immature arteriovenous fistula (hazard ratio = 6.334, confidence interval = 1.364-29.423, p = 0.018), and patients with mixed stenosis had poorer access outcomes (p = 0.016). Immature arteriovenous fistulas can be successfully salvaged by aggressive and timely endovascular intervention. Mixed stenosis is associated with poor access outcomes.

Endovascular management in immature arteriovenous fistula for hemodialysis

To evaluate the outcomes and prognostic factors of endovascular management in immature arteriovenous fistula (AVF) for hemodialysis.From April 2007 to September 2017, 54 patients (male:female = 31:23, mean age 65.63 years, range 33–90 years) who underwent endovascular management for the salvage of immature AVF were retrospectively reviewed. Clinical data, procedural details, and results were evaluated. Primary and secondary patency rates and factors influencing the patency were also analyzed.Technical and clinical success rates were 88.9% (48/54) and 85.2% (46/54), respectively. Mean primary and secondary patency was 42.10 (±8.85) and 91.5 (±14.77) months, respectively. Primary and secondary patency rates were 66% and 89% in 1 year, 66% and 78% in 2 years, and 51% and 78% in 3 years. In multivariate analysis, only brachiocephalic AVF and antegrade access procedures showed significantly shorter primary patency (HR 5.196; 95% CI (1.04–25.77); P = .044, HR 8.096; 95% CI (1.36–48.00); P = .021). There was no statistically significant factor associated with secondary patency in the multivariate study.Endovascular management in immature AVF is safe and effective to make the AVF available. Brachiocephalic AVF and antegrade access procedures are the factors influencing the patency in multivariate analysis.

Percutaneous Salvage of a Thrombosed Immature Arteriovenous Fistula using a Long Segment Stent Graft across the Juxta-Anastomotic and Outflow Vein

The role for stent grafting in the juxta-anastomotic segment for nonmaturing arteriovenous (AV) fistulas is not well understood. We report a case in which a long segment stent-graft of nearly the entire venous limb of a brachiocephalic AV fistula was stented to salvage an access that would likely otherwise have been abandoned. The patient went on to mature his fistula 3 months later and access it for hemodialysis through percutaneous puncture of the stent graft.

Sonographic Evaluation of an Immature Brescia-Cimino Fistula

Arteriovenous fistulas are known to be traumatic, congenital, or created for hemodialysis purposes in patients diagnosed with end-stage renal disease. In this case study of an immature Brescia-Cimino fistula, an outflow vein stenosis was assessed solely using sonography. This type of stenosis has been found to be the most common cause of fistula failure. This case study demonstrates how the use of sonography identified an immature arteriovenous fistula as well as assisted in further treatment planning and outcomes.

Usefulness of assisted procedures for arteriovenous fistula maturation without compromising access patency.

To increase the rate of arteriovenous fistula (AVF) use, assisted procedures for immature AVF have been strenuously performed. However, this is controversial in that an AVF matured by these assisted procedures may require more frequent intervention to maintain its patency, and have decreased long-term patency. Eighty four AVFs that were matured with assisted maturation procedures and 266 AVFs that matured spontaneously without intervention, created between November 2009 and March 2013 from the hemodialysis (HD) vascular access (VA) cohort, were compared retrospectively and we also investigated the factors that may influence AVF long-term patency. Median follow-up was 26.8 months (interquartile range, 6.6-45.0 months). Access survival did not differ between AVFs matured by assisted procedures and spontaneously mature AVFs (P = 0.29). In multivariate Cox regression analysis of AVF survival, age (HR, 1.029; 95% CI, 1.004-1.056; P = 0.024), maturation without assisted procedures 4-6 weeks after AVF creation (HR, 0.233; 95% CI, 0.107-0.506; P < 0.001), and AVF thrombosis (HR, 26.511; 95% CI, 10.986-63.978; P < 0.001) were significantly associated with AVF survival. Performance of assisted procedures to induce AVF maturation did not influence AVF survival (HR, 0.437; 95% CI, 0.191-1.002; P = 0.05). Our results support that idea that assisted maturation procedures can ensure the success of immature AVF without compromising long-term patency. These procedures can be considered more positively for increasing AVF use for VA placement in HD patients.

Endovascular Salvage of Immature Hemodialysis Arteriovenous Fistulae

To assess the anatomical causes of immature hemodialysis arteriovenous fistula (AVF) and the outcome of the endovascular salvage. Over a 4-year period, 51 dysfunctional and 3 thrombosed immature AVF were treated by endovascular intervention, which included percutaneous transluminal angioplasty and accessory vein obliteration by coil insertion or surgical ligation. Anatomical causes, clinical characteristics and the success rate of the endovascular salvage of the immature AVF were retrospectively analyzed. The access types were 27 radiocephalic fistulae, 25 brachiocephalic fistulae, and 2 transposed basilic vein fistulae. Mean interval from access creation to referral to angiography was 116 days (44–349 days). Anatomic problems were identified in 53 cases (98%). The causes of the immature AVF were stenosis (59%), accessory vein (22%), and combined stenosis and accessory vein (15%) and deeply located vein (4%) in the upper arm fistulae, and stenosis (67%), accessory vein (11%), combined stenosis and accessory vein (11%), poor surgical technique (7%), and deeply located vein (4%) in the forearm fistulae. New fistulae were created in the cases of immature AVF due to poor surgical technique, and surgical superficialization was done in the cases of deeply located veins. In the remaining cases, overall clinical success rate of endovascular salvage was 94.4%. Immature AVF should be timely treated, because the most common causes are stenosis and accessory vein. Endovascular intervention can treat majority of cases with high success rate.

Endovascular Salvage of Immature Autogenous Hemodialysis Fistulas

To report the technical success and long-term clinical outcomes of immature arteriovenous fistula (AVF) after percutaneous angioplasty (PTA). Patients with 58 immature AVF underwent PTA treatment in our institute during the past 9 years. Based on pretreatment ultrasound findings, the immature AVFs were categorized as stenosed, thrombosed, and obliterated type. An optimal entry site was punctured under ultrasound guidance followed by conventional fluoroscopy-guided PTA technique. Technical and clinical success as well as complications were recorded. Patency after angioplasty was estimated using Kaplan-Meier analysis. Predictors of patency were estimated using log-rank test. In our series, 50 % (29 of 58), 20.7 % (12 of 58), and 29.3 % (17 of 58) of immature AVF were stenosed, thrombosed, and obliterated, respectively. Technical and clinical success was achieved in 96.6 % (56 of 58) of cases with 100 % success in both the stenosed and thrombosed lesions and 88.2 % (15 of 17) success in the obliterated lesions. Vascular ruptures occurred in 12.1 % (7 of 58) of lesions. The overall primary and secondary patency rates of the 58 lesions were 45.4 and 84.2 % at 12 months and 36.5 and 80.1 % at 36 months. There were no significant differences of patency between the three types of lesions (p = 0.075 and 0.093) and the two groups of patients with or without residual side branches after intervention (p = 0.527 and 0.644). There was a significant difference of primary patency in patients with vascular rupture (p = 0.012) with a hazard ratio of 3.236. PTA could effectively prolong the lifetime of immature AVFs with high technical success. Vessel rupture was predictive of shorter primary patency, and long-term secondary patency was acceptable.

Endovascular treatment for immature autogenous arteriovenous fistula

To evaluate the anatomical causes of maturation failure and to assess clinical outcomes after the causative lesions of immature arteriovenous fistula (AVF) have been corrected by endovascular treatment. The medical records and radiological data from 141 patients who underwent endovascular treatment for immature AVF were retrospectively reviewed. Clinical outcomes, such as the success rates and the patency rates following the procedure, were included. The variables, including patients' age, gender, co-morbidities, fistula age, fistula type, numbers of lesions, degree of stenosis, presence of accessory veins, were analysed as the potential predictors of primary and secondary patency. Technical and clinical success rates were 95.7% (135 of 141 AVFs) and 86.5% (122 of 141 AVFs), respectively. The primary and secondary patency rates were 71.9% and 82.8% at 1 year, 60.1% and 82.0% at 2 years, and 54.5% and 82.0% at 3 years, respectively. By multivariate analysis using Cox proportional hazards model, stenosis of >90% was the only independent predictor for both the primary and secondary patency rates [hazard ratio (HR) 5.026, 95% confidence interval (CI) 2.47-10.24, p < 0.0001 for primary patency and HR 11.076, CI 1.49-82.58, p = 0.019 for secondary patency, respectively]. All immature AVFs had significant anatomical causes of failure to mature, which could be safely and effectively salvaged with endovascular treatment. A degree of stenosis >90% was an independent predictor for both the primary and secondary patency after the treatment.

Strategies for the Creation and Maintenance of Reconstructed Arteriovenous Fistulas Using the Forearm Basilic Vein

Reconstruction of an arteriovenous fistula (AVF) after an initial failure to provide long-term patency has been desired in the era when hemodialysis patients' prognosis is improving. The forearm basilic vein AVF should be considered, before an artificial graft shunt or an AVF in the cubital region. The present study was designed to establish a strategy for the creation and maintenance of AVFs using the forearm basilic vein. This study reviewed 76 cases of reconstructed AVF including 18 cases using the basilic vein (23.7% of total cases). The following four points were considered: arm positioning of the cubital flexion position combined with the forearm supinated position; several small skin incisions with a subcutaneous tunnel; sufficient venous dilatation using Fogarty balloon catheter; and early percutaneous angioplasty introduction for immature AVF. The primary and secondary patency rates were examined. A radiobasilic AVF was created through a subcutaneous tunnel in two cases. The primary and secondary patency rates of AVF with the basilic vein were 54.7% and 76.7% respectively, whereas those of AVF with the cephalic vein were 49.3% and 71.3%. The basilic was not inferior to the cephalic vein (P-value of the log-rank test for primary and secondary patency rates were 0.927 and 0.811, respectively). Early stage percutaneous angioplasty was effective in five cases with immature AVF. The forearm basilic vein was useful in AVF reconstruction and equivalent to radiocephalic reconstruction. Careful observation and percutaneous angioplasty during the early period after the surgery were essential for long-term patency.