Type Of Arteriovenous Fistula Research Articles

Patients referred for arteriovenous fistula construction: a retrospective outcome analysis.

With lower rates of sepsis and re-interventions, arteriovenous fistula (AVF) is the preferred vascular access modality. The aim of this study is to evaluate the outcomes of patients referred for AVF construction at a single center in Cork, Ireland. The current study is a single-center retrospective review of all patients who underwent AVF creation between 2015 and 2017. Additionally, the kidney disease clinical patient management system was used to provide statistics on AVF use in Ireland. 39.3% of hemodialysis patients in Ireland use an AVF for vascular access. Regional use ranged from 50 to 20% across Irish hemodialysis centers. At Cork University Hospital, 192 AVFs were created. The population was 69.3% male (n = 133), 30.7% female (n = 59) with a mean (±SEM) age of 58.8 ± 1.03years. 69.5% of females received a brachiocephalic AVF (BCAVF) while 13.6% had a radiocephalic AVF (RCAVF) constructed. Significance was seen when comparing gender and AVF type (p < 0.001). Fifty-four percent of the fistulae were brachiocephalic (n = 103), 33% were radiocephalic (n = 63), and 4% were brachiobasilic (n = 8). BCAVF patients (62.7 ± 1.2years) were significantly older than patients receiving a RCAVF (54.5 ± 1.9years, p < 0.001). A post-operative thrill or continuous flow on Doppler was present in 99% of patients (n = 190) with maturation and complication rates of 82.7% (n = 153) and 5.7% (n = 11) respectively. 69.9% of AVFs were needled for hemodialysis (n = 114). AVF outcomes at this center are consistent with reported statistics in the literature. Patient age, sex, and diabetic status may influence the use of proximal AVF. AVF creation rates in Ireland are below international reported recommendations.

Arteriovenous Fistula Is a Rare but Significant Finding After Endovenous Thermal Ablation

Endovenous thermal ablation (EVTA) has become the mainstay of treatment for symptomatic varicose veins in the setting of saphenous vein insufficiency. We observed 5 iatrogenic arteriovenous fistulas (AVFs) following thermal ablation of the great saphenous vein (GSV). Postprocedure duplex ultrasound (DUS) results were analyzed for the presence of AVF in any location along or adjacent to the treated saphenous veins. Cases were prospectively followed. English literature was reviewed for any other published reports of AVF after EVTA. Data were compiled using our 5 cases, 2 cases were shared with us by colleagues and 20 cases were reported in the literature. Our center has performed more than 4000 (4155) cases of EVTA over the past 15 years. Five cases of AVFs were detected, 3 were found in asymptomatic patients during routine post-EVTA surveillance. The additional 2 cases presented with signs or symptoms which prompted a DUS after ablation. Including cases in the literature, we were able to identify 2 different types of AVFs. The first type of AVF was demonstrated in 13 cases where the AVF occurred along the treated vein. All of these cases involved ablation of the GSV and 90% of these showed signs of recanalization. The second type of AVF was seen in 14 additional cases where the AVF involved a vein segment adjacent to or remote from the ablated vein. The second type occurred in the GSV in 5 cases, external iliac vein (EIV) in 3 cases, and in the popliteal vein in 5 cases. There is 1 reported case of AVF involving the sural artery after perforator vein EVTA. Three of the type 1 cases were followed and spontaneously resolved; 3 of the type 1 cases were treated with surgical ligation with unreported outcomes. Seven cases did not report any follow-up information. Seven of the type 2 cases were treated, and had spontaneous resolution and 7 were not treated. The follow-up on these cases ranged from 1 month to 6 years. Thermal ablation can result in AVF either along the length of the treated vein or adjacent to the area of ablation. Further study would help elucidate the cause and treatment algorithms.

Revision Using Distal Inflow for the Treatment of Dialysis Access Steal Syndrome: A Systematic Review.

The aim of this systematic review is to establish the efficacy of revision using distal inflow (RUDI) on the primary endpoints of complete dialysis access steal syndrome (DASS) resolution and arteriovenous fistula (AVF) longevity. An electronic search of literature from 1966 to 2017 in CINAHL, Medline, Embase and the Cochrane library according to PRISMA standards was conducted. Quality evaluations and recommendations for practice were examined. Data on power, age, gender, comorbidities, arterial inflow, conduit material, fistulae type, follow-up, failure incidence, ischaemia grade, modality of diagnosis, morbidity and mortality were subjected to pooled analysis of prevalence at a 95% confidence interval (CI). Eleven studies involving 130 individuals with a median age of 57 [interquartile ranges (IQR), 54–65] and equal gender distribution were conducted. Of the patients with diabetes mellitus (67.3%), the most common type of AVF with DASS was brachiocephalic AVF (73.7%). Overall, the prevalence of success was 82.0% (95%CI, 74.4%–89.6%) over 12 months (IQR, 1–40 months). Grade 3 ischaemia was the most common type of DASS (49.2%). Grade 4 had the worst outcomes compared with grades 2 and 3. The overall morbidity was 3% with no mortality. Overall, RUDI is an effective treatment for various grades of DASS and their longevity.

Microsurgery for "wrist" arteriovenous fistula creation in children: a retrospective cohort study.

Creating functional arteriovenous fistulae (AVF) at the wrist is challenging in paediatric patients because of the small calibre of the blood vessels. We report our experience with AVF surgery in children younger than 15 years of age using microsurgical techniques. Twenty-five patients underwent AVF surgery between 2003 and 2015 (20 for haemodialysis, 4 for plasmapheresis and 1 for parenteral nutrition). Median (range) age was 9 (2-15) years and median weight was 24 (8-61) kg. The one-month occlusion rate was 8%. The primary and secondary patency rates at 1, 2, 3 years were: 60%, 49%, 42%, and 82%, 72%, 54%, respectively. The median (range) maturation time was 4.53 (0.5-11.2) months. We found no statistically significant effect of patient age, body weight, type of AVF and indication for AVF creation on the primary and secondary patency rates. Microsurgical AVF creation at the wrist can be performed with satisfactory results and should be the preferred technique in the paediatric population.

Angiographic and Clinical Characteristics of Thoracolumbar Spinal Epidural and Dural Arteriovenous Fistulas.

The purpose of this study is to compare the angiographic and clinical characteristics of spinal epidural arteriovenous fistulas (SEAVFs) and spinal dural arteriovenous fistulas (SDAVFs) of the thoracolumbar spine. A total of 168 cases diagnosed as spinal dural or extradural arteriovenous fistulas of the thoracolumbar spine were collected from 31 centers. Angiography and clinical findings, including symptoms, sex, and history of spinal surgery/trauma, were retrospectively reviewed. Angiographic images were evaluated, with a special interest in spinal levels, feeders, shunt points, a shunted epidural pouch and its location, and drainage pattern, by 6 readers to reach a consensus. The consensus diagnoses by the 6 readers were SDAVFs in 108 cases, SEAVFs in 59 cases, and paravertebral arteriovenous fistulas in 1 case. Twenty-nine of 59 cases (49%) of SEAVFs were incorrectly diagnosed as SDAVFs at the individual centers. The thoracic spine was involved in SDAVFs (87%) more often than SEAVFs (17%). Both types of arteriovenous fistulas were predominant in men (82% and 73%) and frequently showed progressive myelopathy (97% and 92%). A history of spinal injury/surgery was more frequently found in SEAVFs (36%) than in SDAVFs (12%; P=0.001). The shunt points of SDAVFs were medial to the medial interpedicle line in 77%, suggesting that SDAVFs commonly shunt to the bridging vein. All SEAVFs formed an epidural shunted pouch, which was frequently located in the ventral epidural space (88%) and drained into the perimedullary vein (75%), the paravertebral veins (10%), or both (15%). SDAVFs and SEAVFs showed similar symptoms and male predominance. SDAVFs frequently involve the thoracic spine and shunt into the bridging vein. SEAVFs frequently involve the lumbar spine and form a shunted pouch in the ventral epidural space draining into the perimedullary vein.

Effect of first cannulation time and dialysis machine blood flows on survival of arteriovenous fistulas.

To study the effect of cannulation time on arteriovenous fistula (AVF) survival. Methods. Analysis of two prospective databases of access operations and dialysis sessions from 12 January 2002 through 4 January 2015 with follow-up until 4 January 2016. First cannulation time (FCT), defined from operation to first cannulation, was categorized as <2 weeks, 2-4 weeks, 4-8 weeks, 8-16 weeks and ≥16 weeks. Early cannulation was defined as FCT within 4 weeks. AVF survival was defined as the date until the AVF was abandoned. Maximum machine blood flow rate (BFR) for the first 29 dialysis sessions on AVF was analysed. Altogether, 1167 AVF with functional dialysis use were analysed: 667 (57%) radial cephalic AVF, 383 (33%) brachiocephalic AVF and 117 (10%) brachiobasilic AVF. The 631 (54%) AVF created in on-dialysis patients were analysed separately from 536 (46%) AVF created in pre-dialysis patients. AVF survival was similar between cannulation categories for both pre-dialysis patients (P = 0.19) and on-dialysis patients (P = 0.83). Early cannulation was associated with similar AVF survival in both pre-dialysis patients (P = 0.82) and on-dialysis patients (P = 0.17). Six consecutive successful cannulations from the start were associated with improved AVF survival (P = 0.0002). A below-median BFR at the start of dialysis was associated with better AVF survival (P < 0.0001). A below-median increase in BFR in the first 2 months was associated with worse AVF survival (P = 0.007). The type of AVF, diabetes, pre-dialysis state at operation and six successful cannulations from the start were independent predictors for AVF survival. FCT is not associated with AVF survival. Failures to achieve six successful cannulations from the start of dialysis and higher machine BFR in the first week of dialysis are associated with decreased AVF survival.

Outcomes of Arteriovenous Fistula for Hemodialysis in Pediatric and Adolescent Patients.

Purpose:This retrospective review aimed to report the outcomes of arteriovenous fistula (AVF) and to evaluate the suitability of AVF as a permanent vascular access in pediatric populations.Materials and Methods:Data were collected for all patients aged 0 to 19 years who underwent AVF creation for hemodialysis between January 2000 and June 2014.Results:Fifty-two AVFs were created in 47 patients. Mean age was 15.7±3.2 years and mean body weight was 46.7±15.4 kg. Of the 52 AVFs, 43 were radiocephalic AVFs, 7 were brachiocephalic AVFs and 2 were basilic vein transpositions. With a mean follow-up of 49.7±39.2 months, primary patency was 60.5%, 51.4%, and 47.7% at 1, 3, and 5 years, respectively and secondary patency was 82.7%, 79.2% and 79.2% at 1, 3, and 5 years, respectively. Age, body weight, AVF type, the presence of a central venous catheter, use of anticoagulation therapy, and history of vascular access failure were not significantly associated with patency rates. There were 9 cases (17.3%) of primary failure; low body weight was an independent predictor. Excluding cases of primary failure, the mean duration of maturation was 10.0±3.7 weeks. During follow-up, 20 patients (42.6%) underwent kidney transplantation, with a median interval to transplantation of 36 months.Conclusion:AVF creation in children and adolescents is associated with acceptable long-term durability, primary failure rate and maturation time. Considering the waiting time and limited kidney graft survival, placement of AVFs should be considered primarily even in patients expected to receive transplantation.

Outcomes for forearm and upper arm arteriovenous fistula creation with the transposition technique

To study the outcomes of three different types of arteriovenous fistula (AVF) transpositions (forearm cephalic vein transposition [FACVT], upper arm cephalic vein transposition [UACVT], and upper arm basilic vein transposition [UABVT]) for dialysis patients in a single center. A 6-year retrospective review, from 2006 to 2012, was conducted at a single institution in which the surgical outcomes for three different types of AVF transposition were reviewed. Preoperative duplex vein mapping was obtained in all patients to choose the best vein for access. There were 165 patients identified with 77 FACVTs, 52 UACVTs, and 36 UABVTs. Primary access maturation rates for the FACVT, UACVT, and UABVT groups were 86%, 90%, and 97%, respectively (P = .19). All transposed, matured primary AVFs were used after a mean of 9.9 weeks, without additional intervention. Primary 1-year patency for the FACVT, UACVT, and UABVT groups were 63%, 61%, and 70%, respectively (P = .71). Primary assisted 1-year patency for the FACVT, UACVT, and UABVT groups were 93%, 93%, and 100%, respectively (P > .999). Mean operating room times and time to intervention were not significantly different between the groups. The postoperative hematoma rate was 2% and wound infection rate was 2%. Multivariate analysis indicated no significant predictors of time to failure (P > .05). With low primary failure rates, reduced need for secondary interventions before maturation, and 1-year primary assisted patency rates in excess of 93%, our study showed that the transposition technique, in our experience, is superior to previously published literature in hemodialysis access creation.

Vascular access for long-term hemodialysis/hemodiafiltration patients.

We investigated the characteristics of patients who received long-term hemodialysis/hemodiafiltration (HD/HDF) treatment for over 30 years at our group of hospitals and type of vascular access (VA) used. As of August 2014, 950 patients were receiving HD/HDF treatment at one of our hospitals. Of those, we investigated 41 (4.3%) undergoing long-term treatment in regard to their characteristics and VA type. The items subjected to analysis were sex, primary illness, age at time of dialysis initiation, present age, duration (years) of HD/HDF, type of arteriovenous fistula (AVF) and arteriovenous graft (AVG), history of surgery and AVF persistence rate. The subjects consisted of 22 men and 19 women, and their mean HD/HDF duration was 33.4 ± 2.8 years. For primary illness, the majority (n = 31) had chronic glomerulonephritis. The age at time of dialysis initiation was 31.7 ± 7.76 years and present age was 64.5 ± 7.65 years. They had received 3.8 VA surgeries. For present VA type, 23 patients (56.0%) had an AVF and 13 (31.7%) an AVG, while 4 AVF patients (9.7%) had a history of AVG use. One patient (2.4%) had a superficialized artery. The mean HD/HDF duration of the 13 AVG patients was 7 years and the longest was 18 years. AVF persistence rate estimated by the Kaplan-Meier method was 75% at 30 years after dialysis initiation. The present results suggest that the ratio of patients with AVG increased with prolonged HD/HDF treatment. AVG has a higher probability of complications and lower patency as compared to AVF, thus careful management is needed. On the other hand, AVG contributes more to a good long prognosis, as it offers efficient dialysis. In cases of vascular deterioration due to long-term hemodialysis, it is inevitable to change from AVF to AVG, thus the ratio of AVG patients is expected to increase in cases of long-term HD/HDF.

Vascular access in diabetic patients. Are these patients "difficult"?

Diabetics with stage V chronic kidney disease (CKD) on hemodialysis (HD) are considered as "difficult patients", because of problems with creation of the vascular access. There is controversy regarding the results and recommendations for preparation of the vascular access in these patients. The aim of this retrospective study was to evaluate the results of creating different types of arteriovenous fistula (AVFs) in consecutive series of patients starting dialysis treatment. The analysis was performed in 741 patients (385 females and 356 males), average age 61.4±7 years, who started dialysis treatment in our department between January 2005 and December 2012. Native AVFs were created in all patients. No patients received an AVF requiring synthetic graft material. The number of patients with diabetic nephropathy was 166 (22.4%). Among them, 30 (18%) had type 1 diabetes and 136 (82%) type 2. In this group the occurrence of calcification in the forearm artery was estimated on the basis of physical examination, Allan's test, Doppler ultrasound and forearm X-ray. In a subgroup of patients with atherosclerotic changes in the arterial system the frequency of failed AVFs was analyzed. These results were compared with the group without diabetes. The number of procedures necessary for successfu AVF creation and type of access was counted in both groups. The assessment of the procedure frequency and AVF location in diabetic and in non-diabetic patients was made by χ² test with Yates correction. In the group of 166 patients with diabetes, in 100 cases (60%) atherosclerotic changes in forearm arteries were observed. In a subgroup of 30 patients with type 1 diabetes atherosclerosis was observed in 17 adults (57%). In this subgroup creation of a suitable forearm AVF in the first procedure in 9 patients was possible and in the other 8 cases the atherosclerotic changes necessitated repeated procedures and were an important obstacle to create the AVF. In the subgroup of 136 patients with type 2 diabetes, atherosclerosis in the forearm artery was observed in 83 cases (61%). In this subgroup the creation of a native AVF was possible in 40 patients during the first procedure and in 43 cases additional intervention was needed, but only in 8 cases was atherosclerosis the cause of fistula failure. Generally, among 166 patients only in 16 cases (10%) did atherosclerosis present an important obstacle for AVF creation, but the number of necessary procedures to create one functioning AVF was significantly greater in this population (2 v 2.7, p=0.0001). A functioning AVF in patients with diabetes was found significantly frequently in the arm localization in comparison to non-diabetic patients (4.3 v 2%, p=0.0478). Atherosclerotic changes in forearm arteries in diabetic patients appear in 60% of hemodialysis patients and make it difficult to create an AVF only in 10% of diabetic patients, but it is possible to create a native AVF in 90% of diabetic patients, although this requires more procedures. In patients with diabetes, AVF in the wrist region should be preferred.

Advanced teamworking in emergency surgical situations: Improving patient safety through the design of a multi-professional, multi-disciplinary course focusing on non-technical skills

Advanced teamworking in emergency surgical situations: Improving patient safety through the design of a multi-professional, multi-disciplinary course focusing on non-technical skills

Fistula components of brain arteriovenous malformations: Angioarchitecture analysis and embolization prior to gamma-knife surgery

BackgroundGamma-knife surgery (GKS) is ineffective for high-flow arteriovenous fistula (AVF). The purpose of this study was to present the angioarchitecture of the AVF of brain arteriovenous malformation (BAVM) and report our experience of endovascular embolization of AVF component prior to GKS. MethodsIn the past 10 years, a total of 523 BAVMs had been treated primarily by GKS. Among these, 10 patients with AVF components were identified and referred for embolization prior to GKS. Those patients underwent GKS within 4 weeks after embolization. We analyzed retrospectively the angioarchitecture of the AVFs of BAVMs, selection of embolic materials for embolization, and treatment outcomes. ResultsThe location of the AVFs was anterior (n = 7) or middle (n = 3) cerebral artery. Central and peripheral types of AVFs were found in seven and three patients, respectively. Nine AVFs were totally occluded by a single session of endovascular embolization, while one failed to be embolized because it was inaccessible to a microcatheter. Detachable coils (n = 6) or combination of liquid adhesives (n = 3) were selected to embolize the AVF. No significant periprocedural neurological complication was found. BAVMs were obliterated totally by subsequent GKS in six patients and partial occlusion was achieved in one, while three still awaited the effect of GKS. Mean imaging and clinical follow-up periods were 35 and 48 months, respectively. ConclusionEarly detection of the central type of AVF of BAVM prior to GKS may be difficult because of its overlapping with feeder, nidus, and/or venous drains or it being overlooked. Peripheral-type AVFs were usually evident prior to GKS, particularly those with proximal dilated venous drains. Endovascular embolization is an effective modality for managing these AVFs, which may be treated by GKS ineffectively.

Transvenous Coil Embolization of an Intraorbital Arteriovenous Fistula

Purely intraorbital arteriovenous fistulas (AVFs), which are rare vascular malformations that clinically mimic carotid-cavernous fistulas (CCFs), involve a fistula from the ophthalmic artery to 1 of the draining ophthalmic veins. We describe a case of an intraorbital AVF treated with transvenous endovascular coil embolization via the inferior petrosal sinus (IPS) route and review the literature on this rare entity. An 81-year-old woman sought treatment after 7 days of progressive left-sided visual acuity loss, chemosis, and lateral rectus palsy. Magnetic resonance imaging demonstrated dilated vascularity in the left orbit raising suspicions for a CCF. Cerebral angiography showed a purely intraorbital AVF with a fistula between the left ophthalmic artery and superior ophthalmic vein (SOV). Transvenous selective catheterization of the fistula was performed by successfully navigating the ipsilateral IPS to the cavernous sinus and SOV. The fistula was then embolized using detachable coils. The patient was discharged the next day. Three weeks after embolization, her ocular symptoms and findings had resolved. Intraorbital AVFs are a rare type of AVF that can be treated by direct surgical ligation, transarterial embolization, or transvenous embolization. We successfully navigated the IPS, which is frequently stenotic or occluded secondary to chronically increased fistulous drainage, and utilized this route to embolize the fistula with detachable coils.

Patients Characteristics and Outcome of 518 Arteriovenous Fistulas for Hemodialysis in a Sub-Saharan African Setting

To present the particular aspects of arteriovenous fistula (AVF) for hemodialysis in sub-Saharan Africa in terms of patients' characteristics, patency and complication rates, as well as factors influencing them. From November 2002 to November 2009, 518 fistulas were constructed on adults. Demographic data, patency, and complications were analyzed. The association between age, sex, and comorbidities (HIV, hypertension, diabetes) on one hand and complications as well as AVF patency on the other was sought. Males represented 73.7% of the patient population, and the mean age of the population was 45.3 years. As far as etiologies of end-stage renal disease (ESRD) and comorbidities are concerned, chronic glomerulonephritis was the leading cause of ESRD (134; 25.9%), followed by hypertension (22.3%), although prevalent in 83.2% of patients, and diabetes (20.1%), although prevalent in 22.2%. No cause for the ESRD could be identified in 89 patients (17.2%). Only 20.64% had AVF as the initial vascular access. The main types of AVF constructed were radiocephalic (68%) and brachiocephalic (24.9%). The median follow-up period was 275 days. The cumulative patency rate at 1 year and 2 years was 76% and 51%, respectively. Altogether, 188 complications occurred in 16% of the AVFs. Aneurysms, failure to mature, and thrombosis were the most frequent complications occurring in 27.65%, 14.89%, and 10.63% of cases, respectively. The management options for the complications included the creation of a new access for 63 complications (33.51%) and nonoperative management in 44.14% of the cases. We found no adverse effect of comorbid factors like diabetes mellitus (χ(2) = 3.58, P > 0.05) and HIV-positive status (χ(2) = 0.64, P > 0.05) on the complications rate. According to our patients' characteristics, there is a possibility of constructing AVF on nearly every hemodialysis patient with a good outcome.

Outcomes of Secondary Compared to Primary Autogenous Haemodialysis Arteriovenous Fistulae, a Five Year Survey

Aims: We examined the outcome and patency rates of secondary in comparison to primary arteriovenous fistulae (AVF) in a cohort of haemodialysis (HD) patients. Study design: A retrospective review of native AVFs formed in a five year period. Place and Duration of Study: Department of Renal and Vascular Medicine Hull and East Yorkshire Hospitals NHS Trust, East Yorkshire between December 2000 to December 2005. Methodology: HD patients who had autogenous AVF created in a single centre over a 5 year period. 346 patients (mean age 61±16 years, 35.8% females, 29.2% diabetics) were included. Data on type of AVF, demographics, co-morbidities, immediate outcome and subsequent vascular access (VA) patency were collected. Results: 463 AVF were created (304 radiocephalic (RC) and 159 brachiocephalic (BC)), of which 160 (34.6%) were secondary procedures. There was no significant difference in the primary failure rate (PFR) of primary and secondary AVFs (38.9 vs. 37.5% respectively). Primary RC fistulae had a higher failure rate in comparison to BC fistulae (42.6 and 21.3%, respectively, p = 0.002, OR 2.7; CI: 1.4-5.3). There was a higher PFR of AVF among females (primary access: 47 vs. 33% in males, p = 0.028; OR 1.7; 95% CI: 1.1-2.8; secondary access: 53 vs. 27%, p= 0.002; OR 3.1; 95% CI: 1.5-6). There was no difference in PFR of primary and secondary fistulae among Research Article British Journal of Medicine & Medical Research, 2(1): 62-73, 2012 63 diabetics and non-diabetics. Conclusion: The primary success rate of secondary autogenous AVFs is similar to primary fistulae. Females have a higher rate of fistula failure.

Efficiency of the kidney disease outcomes quality initiative guidelines for preemptive vascular access in an academic setting

The National Kidney Foundation-Kidney Diseases Outcomes Quality Initiative (KDOQI) for vascular access guidelines state that patients with late-stage chronic kidney disease (CKD) should undergo native arteriovenous fistula (AVF) creation at least 6 months before anticipated start of hemodialysis (HD) treatments to obviate the need for other vascular access types, such as grafts or central catheters. The objective of this study was to determine the incidence of HD, the functional patency, and associated morbidity of AVFs in patients with late-stage CKD placed according to KDOQI. Consecutive patients with late-stage CKD who underwent AVF creation using KDOQI guidelines for anatomy between January 2003 and December 2007 at two tertiary academic centers were retrospectively evaluated. Baseline demographics, AVF type, and clinical comorbidities were recorded. Patients were stratified into one of four groups (groups A-D) over the follow-up course based on two end points: patency of their AVF and whether or not they began HD. The ideal primary outcome was AVF maturation and use for HD (group A; cumulative functional patency). Other outcomes included AVF patency but no HD (group B), HD with AVF failure (group C), or no HD and AVF abandonment (ie, death, refused hemodialysis, kidney transplant, or fistula failure; group D). Secondary outcomes were time to first cannulation, complications, and secondary interventions. AVFs were created (46% forearm and 54% upper arm) in 150 patients with CKD (85% men, median age 63 years old). At a median follow-up of 10 months, 74 patients (49%) were receiving HD and of these, 48 patients (65%) were using their AVF (group A), whereas 26 patients (35%) were not due to fistula failure (group C). Thirty-four patients (23%) never initiated HD treatments, but had a viable AVF (group B), and 42 patients (28%) never initiated HD and abandoned their AVF (group D). Overall, AVF abandonment was 51%. Mean maturation time of all AVFs successfully cannulated was 285 days (range, 30-1265 days). Complications encountered were maturation failure for cannulation (15%), focal stenosis requiring intervention (13%), inadequate flows on HD (9%), steal syndrome (9%), and thrombosis (8%). Cumulative functional patency for all AVFs was 19% and 27% at 6 and 12 months, respectively, with a mean number of two interventions per AVF (range, 1-10). Mortality during the study was 23%. Despite successful creation and maturation of a preemptive AVF in nearly two-thirds of patients who started HD during the follow-up and given the following observations: the high overall mortality of the population, the morbidity and costs in secondary procedures of AVF creation, and the high incidence of abandonment, it is unclear if this strategy would demonstrate a benefit in a randomized trial when compared to other access strategies.

Efficiency of the KDOQI Guidelines for Vascular Access in an Academic Setting

Background: The National Kidney Foundation-Kidney Disease Outcomes Quality Initiative (KDOQI) for Vascular Access guidelines state that late-stage chronic kidney disease (CKD) patients should undergo native arteriovenous fistula (AVF) creation at least 6 months before the anticipated start of hemodialysis (HD) treatments to obviate the need for other vascular access types. The objective was to determine the incidence of HD, the functional patency, and associated morbidity of AVFs in late-stage CKD patients placed according to KDOQI. Methods: Consecutive patients with late-stage CKD who underwent “first-time” index AVF creation using K/DOQI guidelines for anatomy between January 2003 and December 2007 at three tertiary academic centers were retrospectively evaluated. Baseline demographics, index AVF type, and clinical comorbidities were recorded. Patients were stratified into one of four groups (A-D) over the follow-up course based on the patency of their index AVF and whether or not they began HD. The ideal primary outcome was AVF maturation and use for HD (group A; cumulative functional patency). Other outcomes included AVF patency but no HD (group B), HD with AVF failure (group C), or no HD and AVF abandonment (group D). Secondary end points were time to first cannulation, complications, and secondary interventions. Results: Index AVFs were created (46% forearm and 54% upper arm) in 150 CKD patients (85% male; median age, 63 years). At a median follow-up of 10 months, 74 patients (49%) were receiving HD and 48 (65%) were using their index AVF (group A), while 26 (35%) were not (group C). Thirty-four patients (23%) never initiated HD treatments, but had a viable AVF. AVF abandonment was 51%. Mean maturation time of all index AVFs that were cannulated was 285 days (range, 30-1265 days). Complications encountered were maturation failure for cannulation (15%), focal stenosis requiring intervention (13%), inadequate flows on HD (9%), steal syndrome (9%), and thrombosis (8%). Cumulative functional patency for all index AVFs was 19% at 6 months and 27% at 12 months, with a mean number of two interventions per AVF (range, 1-10). Mortality for the group during the study was 23%. Conclusion: AVF creation in late-stage CKD patients has sobering results. This calls into question the wisdom of early AVF planning in this population.

Two-Stage Basilic Vein Transposition—A New Approach for Pediatric Dialysis Access

Conclusion: Rates of arteriovenous fistula (AVF) maturation and patency in pediatric patients are higher for two-stage basilic vein transposition (BVT) than for BVT performed in one stage. Summary: BVT can be performed as a one-stage or a two-stage procedure. Advantages of a two-stage procedure are potential maturation of smaller veins before the actual transposition, thereby potentially improving ultimate success of the transposition. The two-stage procedure is technically easier than a one-stage transposition but does involve two separate procedures. The authors sought to determine whether using two-stage BVTs in children improves fistula maturation rates, fistula use, and overall patency compared with one-stage BVTs, other types of AVFs, and AV grafts. The study took place at two tertiary care children's hospitals. Between 1997 and 2008, 31 patients underwent AV access creation. Forty-two access procedures were performed: 15 two-stage BVTs (36%), 13 one-stage BVTs (31%), 6 radiocephalic fistulas (14%), 3 brachiocephalic fistulas (7%), 1 brachiobrachial fistula (2%), and 4 AV grafts (10%). Average follow-up was 20.4 ± 3.2 months for two-stage BVT and 47.9 ± 4.1 months for other AVFs. All two-stage BVTs matured, but only 14 of 27 (52%) other AVFs matured (P = .001). More two-stage BVTs (87%) were used for dialysis than other AVFs (48%; P = .024). The fistula failure rate in the two-stage BVT was 7% compared with 59% for other AVFs (P = .001). The patency at 1-year was 91% for two-stage BVT vs 47% for other AVFs (P = .003). The size of the basilic vein increased from 0.3 ± 0.027 cm before the performance of the first stage of the BVT to 0.79 ± 0.08 cm after the first stage of the two-stage BVT. Of the 16 failures in the other AVF group, 11 were primary failures occurring before attempted access. One case of steal syndrome occurred in the two-stage BVT group. Comment: Establishing durable hemodialysis access is difficult in all patients and is particularly difficult in the pediatric population because of the overall small caliber of the vessels. Most of the patients in this study, however, were not small children but adolescents with reasonable size vessels to work with. It is therefore a bit unclear whether the apparent advantage of the two-stage BVT in these patients was due to converting a more difficult procedure to a less difficult procedure for performance by surgeons who do not perform large volumes of dialysis access surgery. Two-stage BVT requires two operations, but the first is a relatively small procedure. Given the big picture, there appears to be no great disadvantage to the two-stage procedure and there may be a significant advantage in pediatric patients. The authors' contention that two-stage BVT should be preferred hemodialysis access in the pediatric population deserves consideration.

Type of arteriovenous fistula, NYHA class and apelin in hemodialyzed patients

Apelin, a newly discovered adipocytokine, is produced by white adipose tissue and also expressed in kidney and heart. Increasing evidence suggests a role for apelin in the pathology of the cardiovascular system. It was demonstrated that apelin may contribute to the pathophysiology of human chronic heart failure. Apelin locates at the endothelium-a site of key functional importance in the kidney, and apelin has been shown to increase cardiac output. Cardiovascular disease is a major contributor to the mortality and morbidity of patients with chronic renal failure. We previously found that apelin was significantly lower in dialyzed patients with coronary artery disease and its level was predicted by cardiac function. Creation of a-v fistula might contribute to the development or worsening of chronic heart failure. The aim of this study was to assess associations between apelin, other adipocytokines, NYHA class and location of a-v fistula in hemodialyzed patients. This cross-sectional study was performed on a cohort of one hundred, clinically stable hemodialyzed patients. We investigated plasma apelin as well other adipocytokines: resistin, visfatin and von Willebrand factor (vWF)-a marker of endothelial cell injury. In patients with a-v fistula on the forearm (n=77), apelin was significantly higher than in patients with a-v fistula on the arm (n=23) (56.79±23.56 vs. 43.12±23.19pg/ml). Patients with forearm a-v fistula had lower left ventricular internal end-diastolic dimension (LVIDd) (P<0.05), left ventricular internal end-systolic dimension (LVISd) (P<0.05), NYHA class (P<0.05), hsCRP (P<0.01), plasma vWF (P<0.01), and plasma resistin (P<0.05), whereas the ejection fraction was higher than in patients with arm a-v fistula (P<0.05), as well as hemoglobin (P<0.05), hematocrit (P<0.01), prevalence of diabetes (n<0.05), prevalence of coronary heart disease (P<0.05), serum pH (P<0.05), serum bicarbonate (P<0.05). Apelin was related to echocardiographic parameters, presence of diabetes, coronary artery disease, chronic heart failure, NYHA class and serum lipids (total cholesterol, LDL, triglycerides), hsCRP, vWF, residual renal function, and Kt/V. In multiple logistic regression analysis, apelin was significantly associated with ejection fraction (beta value was -0.51, P=0.007), the presence of diabetes (beta value 0.39, P=0.049), a-v fistula arm location (beta value 0.42, P=0.047). Multiple adjusted r (2) for variables in the equation=0.45, F=1.75, P=0.04, SE of estimate=20.85. Apelin level in dialyzed patients is predicted by cardiac function, presence of diabetes and location of a-v fistula. Apelin might be involved in the pathophysiology of cardiovascular disease in chronic renal failure. The arm location of the fistula might contribute to the development or the worsening of chronic heart failure in hemodialyzed patients.

Pre-Operative Vessel Mapping and Early Post-Operative Surveillance Duplex Scanning of Arteriovenous Fistulae

To increase the proportion of dialysis patients using native arteriovenous fistulae (AVF), improved selection of the most appropriate procedure must be coupled with early access surveillance to determine which access would likely mature and when intervention might lead to access salvage. This study was aimed at auditing pre-operative vessel mapping and post-operative access surveillance against the primary outcome measure of AVF maturation. Between January 2006 and August 2007, 113 AVF created in 101 patients were studied. Data on pre-operative vessel mapping, type of AVF, post-operative surveillance scans were analyzed against the outcome AVF. Pre-operative mapping and post-operative scanning were carried out in 86% and 91%, respectively. A maturing fistula on post-operative scan highly correlated with a satisfactory outcome (p<0.001). The sensitivity and specificity of the post-operative scan were 100% and 85%, respectively. There were 79 brachiocephalic and 34 radiocephalic fistulae with a primary failure rate of 23% and 47%, respectively, giving an overall failure rate of 30%. Nine fistulae had further intervention (angioplasty or thrombolysis) and five (56%) were salvaged. Seventy-two AVF matured satisfactorily giving a primary cumulative patency of 71% (72/102). This study shows that preoperative vessel mapping provides useful information regarding the choice of AVF. Access surveillance duplex scanning at 6-8 weeks post-operatively is viable and has a high sensitivity and specificity for final outcome of fistula. Identifying AVF with potential problems early means that further intervention or surgery can be planned earlier, which will have a positive impact on patients.