Fistula Failure Research Articles

Primary Failure of Autogenous Arteriovenous Fistula: Critical Analysis.

Introduction:Permanent vascular access is an essential intervention in patients with advanced chronic kidney disease (CKD) and its success depends on various non-modifiable and modifiable factors. Considering the element of unpredictability and failure, we attempted to analyze various factors responsible for primary arteriovenous fistula (AVF) failure in presumed high-risk groups.Materials and Methods:We conducted an observational study of newly created AVFs at a tertiary referral government hospital in Eastern India between January 2014 and June 2015. All adult CKD patients undergoing AVF creation were included. Primary AVF failure was assessed at 12 weeks and total follow-up was 24 weeks in presumed high-risk groups of females, patients aged ≥65 years and those with diabetes mellitus.Results:Female gender was at a higher risk of primary AVF failure if aged ≥65 years (P = 0.0026), second AVF creation (P = 0.03), loupe magnification not used (P = 0.03), arterial plaque (P = 0.028), absent immediate thrill, and with radiocephalic AVF (P = 0.02). Absent immediate thrill (<0.0001) and AVF size ≤5 mm (P = 0.002) were important independent risk factors for primary failure. Diabetes or elderly age did not have additional risk, except with uncontrolled hypertension and female gender.Conclusion:Female gender was at a higher risk of poor unassisted AVF patency if their age was ≥65 years, had second AVF creation, loupe magnification not used or if arterial plaque was present. An absence of thrill immediately or at 24 hours or an AVF diameter ≤5 mm were independent intraoperative factors for poor outcome. On the contrary, diabetics, elderly males and intimal thickness were essentially noncontributors for AVF failure, except in few subsets.

A mouse model of stenosis distal to an arteriovenous fistula recapitulates human central venous stenosis

ObjectiveCentral venous stenosis (CVS) is a major cause of arteriovenous fistula (AVF) failure. However, central veins are relatively inaccessible to study with conventional Doppler ultrasound methods. To understand mechanisms underlying AVF failure owing to CVS, an animal model was established that creates a stenosis distal to an AVF. We hypothesized that this mouse model will show comparable morphology and physiology to human CVS. MethodsAn aortocaval fistula was created between the distal aorta and inferior vena cava (IVC); a stenosis was then created distal to the fistula by partial IVC ligation. Sham-operated animals, AVF without venous stenosis, and venous stenosis without AVF were used as controls. Physiologic properties of the IVC, both upstream and downstream of the stenosis, or the corresponding sites in models without stenosis, were assessed with ultrasound examination on days 0 to 21. The spectral broadening index was measured to assess the degree of disturbed shear stress. The IVC was harvested at day 21 and specimens were analyzed with immunofluorescence. ResultsThe IVC diameter of mice with an AVF and stenosis showed increased upstream (P = .013), but decreased downstream diameter (P = .001) compared with mice with an AVF but without a stenosis, at all postoperative times (days 3-21). IVC wall thickness increased in mice with an AVF, compared with IVC without an AVF (upstream of stenosis: 13.9 μm vs 11.0 μm vs 4.5 μm vs 3.9 μm; P = .020; downstream of stenosis: 6.0 μm vs 6.6 μm vs μm 4.5 μm vs 3.8 μm; P = .002; AVF with stenosis, AVF, stenosis, sham, respectively). AVF patency significantly decreased in mice with an AVF and stenosis by day 21 (50% vs 90%; P = .048). The IVC of mice with AVF and stenosis showed a venous waveform with pulsatility as well as enhanced velocity at and downstream of the stenosis; similar waveforms were observed in a human case of CVS. Downstream to the stenosis, the spectral broadening index was significantly higher compared with mice with AVF alone (1.06 vs 0.78; P = .011; day 21), and there was a trend towards less immunoreactivity of both Krüppel-like factor 2 and phosphorylated-endothelial nitric oxide synthase compared with mice with an AVF alone. ConclusionsPartial IVC ligation distal to a mouse aortocaval fistula alters the fistula diameter and wall thickness, decreases patency, and increases distal disturbed flow compared with fistulae without a distal stenosis. Our mouse model of stenosis distal to an AVF may be a faithful representation of human CVS that shows similar morphology and physiology, including disturbed shear stress.

Nipple-sparing mastectomy through periareolar incision with immediate reconstruction.

PurposeNipple-sparing mastectomy (NSM) has become increasingly popular due to improved cosmesis without compromising oncologic safety. Radial and inframammary incisions are usually used to achieve NSM, with periareolar incisions usually being avoided because of the risk to nipple-areola complex viability. In an attempt to maximize esthetic effects, we performed NSM through periareolar incision with immediate reconstruction. We report our initial experience.MethodsThis case series consisted of all consecutive patients (n = 34) who underwent NSM through a periareolar incision in our institution between August 2017 and December 2018. All patients underwent NSM through periareolar incision followed by immediate reconstruction with an implant or deep inferior epigastric perforator flap. Patient demographics, tumor and treatment characteristics, and short-term postoperative outcomes were reviewed.ResultsThe mean patient age was 46.74 ± 6.69 years (range, 38–62 years), and the mean operation time was 96.68 ± 28.00 minutes. Indications included in situ cancer in 12 cases and invasive cancer in 22 cases. There was 1 major complication (postoperative hematoma) requiring operative reintervention. No other complications including fistula, implant exposure, or reconstruction failure was observed. At the time of writing, no case of local recurrence has been observed.ConclusionOur initial report shows that NSM with immediate reconstruction may successfully be performed through periareolar incision. This method maximizes esthetic effects and may be an appropriate surgical option for NSM.

Robotic pancreatoduodenectomy in the Netherlands: A multicenter analysis of the first 100 procedures

Background: Minimally invasive surgery is currently the gold standard for many surgical procedures. Most pancreatoduodenectomies, however, are still being performed through laparotomy. As conventional laparoscopy is limited by the rigid visual- and working axis, it might be less suited for complex procedures such as pancreatoduodenectomy. Robotic technology potentially offers a solution. The technically enhanced articulating instruments and 3D vision allow for optimal surgical dexterity, as needed during meticulous dissection and construction of the anastomoses in pancreatoduodenectomy. The aim of this study was to determine safety and feasibility of robotic pancreatoduodenectomy in the Netherlands. Materials and Methods: This is a multicenter post hoc analysis of prospective databases from three high volume Hepato-Pancreato-Biliary centers in the Netherlands. Outcomes were scored during index admission. The first 100 patients undergoing robotic pancreatoduodenectomy were included. Primary endpoint was severe complication, defined as occurrence of one or more of the following complications: post-pancreatectomy hemorrhage (ISGPS gr.B/C), pancreatic fistula (ISGPS gr.B/C), multi- or single organ failure or death. Results: In total, 100 consecutive patients underwent robotic pancreatoduodenectomy. Proven or suspected malignancy was the most frequent indication for resection (n=78). A total of 22 patients suffered from a severe complication. Delayed gastric emptying (ISGPS gr.B/C) occurred in 26 patients. Pancreatic fistula (ISGPS gr.B/C) occurred in 19 patients and 9 patients suffered from post-pancreatectomy hemorrhage (ISGPS gr.B/C). Severe bile leakages (ISGPS gr.B/C) occurred in 9 patients. A total of 7 patients underwent relaparotomy during index admission. Two patients developed multiple organ failure. In 8 patients the minimally invasive procedure was converted to open pancreatoduodenectomy. There was no postoperative in-hospital or 30-day mortality. Conclusion: These outcomes of the first 100 robotic pancreatoduodenectomies demonstrate that this procedure was introduced safely in three hospitals in the Netherlands without postoperative mortality and acceptable morbidity. Our results justify further expansion of robotic pancreatic surgery.

Outcomes from our model for a nurse-led vascular renal access surveillance clinic

Background: A patent arteriovenous fistula (AVF) with adequate flow is essential for performing successful hemodialysis. However, the literature currently reports 1-year patency rates of 69%–74%. Surveillance of AVFs has been proposed to prevent failure of fistulas with the associated morbidity and mortality. We implemented a renal access surveillance clinic with the aims of detecting stenoses and arranging treatment to avoid underdialysis and thrombosis of AVFs. Methods: The nurse-led vascular renal access surveillance clinic (VRAC) of the Royal Brisbane and Women's Hospital was created in 2015. The surveillance program is run by a full-time vascular clinical nurse with experience in renal access. Over the 3-year period of 2015–2017, 1006 patients were in the surveillance program. We compared the rates of intervention on fistulas and the incidence of thrombosed fistula in the 5 years preceding the initiation of our VRAC surveillance program, with the 3 years after it was commenced. Results: Our results show that our rates of intervention on threatened fistulas have increased since the program was established, and that the percentage of thrombosed fistulas has remained stable. Allowing this early triage has expedited management and freed more outpatient clinic time. Conclusion: We have compared outcomes before and after implementation of a nurse-led dialysis access surveillance program and have found that the percentage of thrombosed fistulas has remained stable as the rates of intervention have increased for threatened fistulas.

血液透析患者内瘘失功原因及内瘘成熟时间的横断面调查研究

血液透析患者内瘘失功原因及内瘘成熟时间的横断面调查研究

Outcomes of Patients Referred for Arteriovenous Fistula Construction: A Systematic Review

Chronic Kidney Disease (CKD) affects 10-16% of the US population and its incidence is rising due to increasing prevalence of associated risk factors. Renal replacement therapy is required to treat late stage CKD and hemodialysis is the preferred modality for many patients. Vascular access is required for hemodialysis and arteriovenous fistulas (AVF) are currently the gold standard. This review intended to collate current knowledge on AVF outcomes regarding both the patient and fistula. Scopus and Medline were utilized to identify relevant literature. Inclusion and exclusion criteria were applied to narrow search results. Among CKD patients, 33.5-77.4% require a central venous catheter (CVC) before dialysis through a fistula. Many patients (33-51%) use a CVC regardless of AVF creation due to fistula immaturity or failure. There are large variations in AVF creation policies internationally; 16% of American hemodialysis patients use a fistula compared to 72% of German patients. Primary patency and primary AVFs' failure ranges from 60-70% and 20-26%, respectively. AVFs reduce morbidity and mortality in CKD. At present, too many patients are receiving hemodialysis through a CVC. Inadequate referral times for AVF creation can lead to fistula immaturity or failure in the intervention. Many countries are lagging behind recommended AVF creation rates published by the Kidney Disease Outcomes Quality Initiative. There is a paucity of literature concerning when a patient should be referred for AVF creation. It is paramount to have better predictive outcome measures and more clarity as to when patients will benefit from an AVF.

Diagnostic validity of CAVeA2T2 score in predicting failure of radiocephalic arteriovenal fistula in terminal stage renal failure patients at Sanglah Hospital, Bali, Indonesia

Introduction: Chronic kidney disease (CKD) is a global public health problem with increasing prevalence and incidence and poor prognosis. As a result, more patients will be in terminal stage kidney failure and require placement of vascular access for hemodialysis. Mature and functional arteriovenous fistula (AVF) is considered the best modality for access to hemodialysis. This study aims to examine the CAVeA2T2 scores in predicting failure of arteriovenous fistula radiocephalic, significant factors related to failure of arteriovenous fistula so that it can be used to predict failure using a scoring system to predict primary failure and secondary failure fistula.Methods: A cross-sectional study was carried out at Sanglah Hospital, Bali, Indonesia, during the study period. This study using diagnostic test evaluation method using ROC curve analysis on months 1 and 3, a total of 50 populations obtained using Purposive sampling quota period April 2018 - December 2018 and failure of Hemodialysis as gold standard. Data were analyzed using Stata version 12 for Windows.Results: Results of the CAVeA2T2 score where the maximum score of 7 was analyzed using the ROC curve, the cutoff point was obtained at month 1 ≥5 with AUC 0.8987 and at 3 months ≥ 4 with AUC 0.3966 sensitivity and specificity CAVeA2T2 score of 91.3% and 75% in month 1, in the 3rd month 85.7% and 87.5% were obtained.Conclusion: Sensitivity and specificity values that provide a good value so that the CAVeA2T2 score can be used to predict failure of arteriovenous radiocephalic fistulas.

Efficacy of Endovascular Treatment of Central Vein Stenosis to Improve Vascular Access Performance in Hemodialysis Patients

Introduction - central venous stenosis is one of the main causes of late arteriovenous fistula (AVF) failure. The endovascular techniques available for the treatment of central vein (CV) stenosis or obstruction (EVT) have been widely described in literature, however few studies have analyzed their efficacy in improving the AVF dialytic performance. Aim of our study is to evaluate the effectiveness of EVT in preserving AVF and improving its performance.

Outcomes After Primary Arterio-venous Fistula Formation for Haemodialysis Access in End Stage Renal Disease: Four Year Follow-up of Patients at a Single Centre in New Zealand. Should we be Prioritising Success Over Vein Conservation in a Population With Short Life Expectancy?

Introduction: Despite many studies reporting fistula patency rates and secondary interventions, few studies report longitudinal patient outcomes after first fistula formation. 23% of NZ haemodialysis patients are patients of Counties Manukau Health1. Many of these patients have a short life expectency due to co-morbidities, particularly in the older age group. The concept of conserving vein for future fistulas is therefore less valid. It is desirable to achieve a successful fistula with the first procedure. We assessed whether a vein conserving approach compromised successful outcome in Counties Manukau patients. Methods: A prospective analysis was undertaken of patients whose first fistula was formed between 1st January 2010 and 31st December 2014 by 2 surgeons at Counties Manukau Health, Auckland, NZ. Data collected included; demographics, dialysis status, fistula usage, reasons for not using the fistula, need for further fistula formation and patient outcome as at December 2018. Patients with prior attempt at fistula formation were excluded. The primary outcome was a successful fistula, defined as being the sole method of dialysis for over 6 months. Secondary outcomes were reasons for fistula failure. Results: Overall, 154 patients met inclusion criteria with ages ranging from 20 to 77 years (median 57) with 58% male. 78% were Maori or Pacific, compared with 59% in the NZ haemodialysis population1. Diabetes (71%) was one of the most prevalent co-morbidities, higher than the NZ haemodialysis population (58%). With respect to fistula formation, 2 patients had PTFE grafts, the rest were autologous vein. Radiocephalic fistulas comprised the majority 109(71%), with 17(16%) failed. There were 38(25%) brachiocephalic fistulas formed, with 14(37%) failed. Follow up for 2 patients could not be completed and all patients had a minimum of 4 years follow up. There were 4 outcome categories: 99(64%) fistulas were used until death, transplant or end of follow-up; 17(11%) were used for 6 or more months (median time to failure of 45 months); 32(21%) failed and had further procedures; and 6(4%) never used the fistula. Of the 17 that were used for over 6 months then failed, 1/3 were due to infection and secondary bleeding and 1/3 due to previously unrecognised central stenosis. 6 of the 32 failed fistulas(19%) were ligated due to steal syndrome all of which were brachiocephalic fistulas.16% of all brachiocephalic fistulas. Conclusion: The cohort of 154 patients had 64% requiring only one fistula formation and 11% had successful usage for a median of 45 months. Rates of infection and bleeding were higher than expected. This was surprising given the majority were autologous veins. There were also high rates of undiagnosed central stenosis indicating a need for central venous imaging preoperatively. Brachiocephalic fistulas had16% (6/38) risk of steal syndrome which could be attributed to the high rates of diabetes in the cohort, increasing the risk of microvascular complications. In summary, the current policy of a vein conserving approach is satisfactory. Moving to a larger more proximal vein is associated with increased risk of complication, in particular, steal syndrome. There is a role for further assessment of distal perfusion in these patients. Disclosure: Nothing to disclose

Increased Brachial Artery Compliance After Arteriovenous Fistula Creation as Measured by Shear Wave Elastography: Results From a Feasibility Study.

Arterial stiffness has been proposed as a marker of arteriovenous fistula failure and can be measured locally by using ultrasound shear wave elastography (SWE). This preliminary study aimed to assess whether SWE measurements of the brachial artery were associated with arteriovenous fistula failure. Data were collected on patients who were indicated for fistula creation. Preoperative and postoperative vessel diameters from B-mode ultrasound, brachial artery SWE maps, and demographic data were collected. Logistic and linear regression analyses were used to determine whether any of these variables were related to the outcome of the fistula 3 months after creation. Data were acquired for 33 patients. Shear wave velocity values decreased after fistula creation (mean ± SD, -1.2 ± 1 m/s; P < .05). No parameters were associated with failure of the fistula in the logistic regression analysis. No markers were related to fistula failure, but a decrease in the shear wave velocity was observed in the brachial arteries after fistula creation, indicating increased compliance.

Serum levels of the endothelial glycocalyx constituents and the early failure of forearm autologous arteriovenous fistulas in end-stage renal disease patients: a prospective cohort study.

The relationship between the endothelial glycocalyx constituents and the early failure of autologous arteriovenous fistulas (AVFs) in ESRD patients is still unknown. In this prospective cohort study, 181 ESRD patients (the mean age was 53.3 ± 11.8years, 66.3% of them were males) received forearm AVFs surgery were consecutively enrolled with a median follow-up time of 10months. The early AVF failure was defined as a fistula that never developed adequately for dialysis use or that failed within the first 3months of use. The serum levels of glycocalyx constituents including glypicans-1 (GPC-1), syndecans-1 (SDC-1), and hyaluronan (HA), and the indicator of endothelial activation reflected by E-selectin (ES) were determined by ELISAs. The primary patencies of AVFs were 98.3%, 96.7%, 91.7%, and 89.5% at 3, 6, 12, and 18months, respectively. The ROC curve was plotted and demonstrated that HA, not GPC-1, SDC-1 or ES, can diagnose the AVF failure, with the cut-off value of 6.37ng/ml, the sensitivity of 87.5%, the specificity of 46.9%, and the Youden index of 0.34, respectively. The Kaplan-Meier survival analysis demonstrated that patients with HA < 6.37ng/mL had better patency of AVFs than patients with HA ≥ 6.37ng/mL (log-rank test, p = 0.008). In the Cox proportional hazards analysis, after adjusting for confounders, HA (≥ 6.37ng/mL vs. < 6.37ng/mL) was associated with the early AVFs failure, with the OR of 5.88 (1.21-28.60). This study demonstrated that HA can predict the early failure of forearm AVFs, when its serum level is more than 6.37ng/mL.

Preoperative noninvasive artery flow volume and maturation of arteriovenous fistulae: A single surgeon's experience from 403 cases.

Preoperative Doppler ultrasound evaluation of arteriovenous fistula inflow artery includes measurements of arterial diameter and flow volume. The purpose of this study was to evaluate the significance of flow volume to arteriovenous fistula maturation rate. Review of consecutive patients who underwent arteriovenous fistula creation by a single surgeon. Cases with available preoperative arterial diameter and flow volume were analyzed. Primary end point was arteriovenous fistula failure to mature. Information collected included demographics, Doppler ultrasound reports, level of inflow artery, operative reports, and outcomes to the time of arteriovenous fistula maturation or failure. Risk factors were identified by logistic regression analysis. Outcomes were compared by odds ratio. Four hundred and three cases were identified. Arterial diameter and flow volume were both independent significant risk factors affecting arteriovenous fistula maturation rate (p = 0.001). Arterial diameter of <2.5 mm and flow volume of <20 mL/min predicted failure to mature with 95% specificity. Further comparison of cases with optimal arterial diameter but flow volume of <20 mL/min showed increased failure to mature rate compared to the combination of optimal arterial diameter with optimal flow volume (p = 0.01). Preoperative arterial diameter and flow volume values were both significant independent variables affecting arteriovenous fistula maturation rate. However, flow volume of <20 mL/min remained a significant risk factor to failure-to-mature rate, despite optimal arterial diameter.

Preoperative cephalic vein diameter and diabetes do not limit the choice of wrist radio-cephalic arteriovenous fistula.

To identify predictors that affect initial maturation of new wrist radio-cephalic arteriovenous fistula and evaluate the clinical effects of the ipsilateral mid-forearm radio-cephalic arteriovenous fistulas creation in the event of first wrist radio-cephalic arteriovenous fistula failure. We performed a retrospective review of all patients who underwent first wrist radio-cephalic arteriovenous fistula creation between September 2016 and May 2018. Currently, we prefer to re-create an ipsilateral mid-forearm radio-cephalic arteriovenous fistula when the first wrist radio-cephalic arteriovenous fistula fails. Predictors of successful radio-cephalic arteriovenous fistulas were identified using univariate and multivariate analyses. Kaplan-Meier survival analysis and log-rank test were used to calculate successful radio-cephalic arteriovenous fistula rates. Univariate analysis showed that predictive factors for successful wrist radio-cephalic arteriovenous fistula include larger preoperative cephalic vein diameter (p = 0.001) and non-diabetic kidney disease (p = 0.007). Multivariate binary logistic regression analysis revealed cephalic vein diameter ⩾2 mm (odds ratio = 4.55, 95% confidence interval = (1.49-13.92), p = 0.008) and non-diabetic kidney disease (odds ratio = 4.22, 95% confidence interval = (1.38-12.88), p = 0.011) to be independent predictors for successful radio-cephalic arteriovenous fistula. We re-created ipsilateral mid-forearm radio-cephalic arteriovenous fistulas in 15 patients among the 21 failed wrist radio-cephalic arteriovenous fistulas; all these arteriovenous fistulas maintained clinical maturation following up for 1-2 years. Small cephalic vein diameter (<2 mm) and diabetes were independent risk factors for failed wrist radio-cephalic arteriovenous fistulas, but this risk could be overcome by aggressive ipsilateral mid-forearm radio-cephalic arteriovenous fistula to address a failed first attempt. Cephalic vein diameter is more important during the maturation stage, and once maturation has occurred, diabetes has an additive role in determining the patency of wrist radio-cephalic arteriovenous fistula. The "wrist RCAVF first, ipsilateral mid-forearm RCAVF second" strategy is the most clinically significant message of our study.

DENTAL INFECTION LEADING TO A PULMONARY CATASTROPHE IN AN IMMUNOCOMPETENT PATIENT

SESSION TITLE: Monday Medical Student/Resident Case Report Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: 10/21/2019 02:30 PM - 03:15 PM INTRODUCTION: Necrotizing pneumonia is a rare complication of bacterial lung infection. It is caused by either a virulence factor of the microorganism or a predisposing factor of the host. Nearly 4% of all community acquired pneumonias are necrotizing. Most common pathogens are S. aureus, S. pneumoniae and K. pneumoniae. This disease may cause devastating complications such as diffuse pulmonary inflammation, parapneumonic effusions, empyema, bronchopleural fistula, septic shock, and respiratory failure, making treatment more difficult. Peptostreptococcus species are anaerobic gram-positive coccus, part of normal flora on mouth, skin and soft tissue, bone and joints, gastrointestinal and genitourinary tracts. It can become pathogenic under traumatic or immunosuppressed conditions. They can cause brain, liver and lung abscess, as well as necrotizing infections. CASE PRESENTATION: We present a 32 years-old male patient without comorbidities who complains of right upper quadrant and right hemithorax pain of 5 days evolution. Chest Pain 10/10 intensity, non-radiating, without alleviating or aggravating factors. Due to progressive shortness of breath, tachycardia and fever, he seeks for medical help for evaluation. Physical exam remarkable for acute respiratory distress, decreased breath sounds from mid lung to base on right hemithorax and right upper quadrant tenderness. He also complains about a tooth pain in molar number 2 that is fractured. He had gums edema, erythema without secretions. DISCUSSION: Laboratory workup show leukocytosis with left shift and 22% of bands. New Chest X-Ray showed right costophrenic angle opacification for which Chest CT scan was performed and demonstrate a right large pleural effusion and a small pneumothorax. He developed acute respiratory distress, shortness of breath, hypoactivity, persistent tachycardia and worsening hypoxemia. Right thoracostomy tube was placed, were purulent and fetid fluid was drained; Light’s Criteria consistent with an exudate; cytologic diagnosis shows necrotic material with bacterial colonization with final fluid culture growth of Peptostreptococcus prevotii. Blood cultures also found with same bacteria. HIV and hepatitis panel were negative. Directed antibiotic therapy with piperacillin/tazobactam was ordered. Due to loculated empyema Alteplase and DNAse therapy were given. With the adequate treatment he had resolution of effusion and symptoms. CONCLUSIONS: Empyema with Peptostreptococcus prevotii, which is a local flora of gastrointestinal tract, and could be acquired after a dental infection. Due to the aggressiveness of this conditions and high mortality rate, patient survival is dependent on an early recognition. Medical and surgical intervention with proper antimicrobial therapy has a cure of 90-95% after appropriate management. Physicians should be aware of this entity because mortality can be higher as 75% without adequate management. Reference #1: Tsujimoto N, Saraya T, Light RW, et al. A Simple Method for Differentiating Complicated Parapneumonic Effusion/Empyema from Parapneumonic Effusion Using the Split Pleura Sign and the Amount of Pleural Effusion on Thoracic CT. PLoS One 2015; 10:e0130141. DISCLOSURES: No relevant relationships by Ricardo Bauza Vinas, source=Web Response No relevant relationships by Marlene Farinacci Vilaro, source=Web Response No relevant relationships by Ricardo Fernandez, source=Web Response No relevant relationships by Luis Gerena Montano, source=Web Response

Evaluation of hemodynamic impact of absorbable sutures in native arteriovenous fistulas: A retrospective study.

One of the major causes of arteriovenous fistula failure is the venous stenosis due to aggressive neointimal hyperplasia. The aim of the study was to assess the arteriovenous fistula maturation comparing absorbable sutures and non-absorbable ones in native vessels. Surgeries performed during a period of 24 months by a single team of expert surgeons were evaluated. Surgeries that met the inclusion criteria, namely, age ⩾ 18 years and radio-cephalic arteriovenous fistula, were considered. According to type of suture, patients were classified as Max group (absorbable suture) and Prol group (non-absorbable). Data pertaining to 70 patients were collected; 51% were men and the mean age was 73 ± 12 years. In Max group, an increasing blood flow was observed during the first 4 weeks without post-operative complications. In Prol group, six patients had thrombosis that resulted in vascular access failure. After the first week, the duplex Doppler ultrasound of both groups showed a regular arteriovenous fistula maturation, with an increase of blood flow rate. Although pre-operative post-tourniquet mean vein diameters of Max group were not adequate, the mean vein diameter and mean blood flow rate increased after 4 weeks, respectively. On the contrary, in Prol group, mean vein diameters and blood flow rate decreased. The maturation of arteriovenous fistula and its functional performance were not altered by the type of suture (absorbable/non-absorbable). Absorbable sutures were associated with good results considering arteriovenous fistula maturation.

Thrombophilic risk factors in hemodialysis: Association with early vascular access occlusion and patient survival in long-term follow-up.

ObjectiveThrombophilic risk factors (TRFs) occur rather frequently in hemodialysis (HD) patients. However, little is known about their significance in HD patients, besides their potential impact on arteriovenous (AV) access failure, with varying results. We examined the effects of a wide variety of TRFs on both early AV fistula occlusion and survival among HD patients in long-term follow-up.MethodsIn this single-center, observational study, 70 consecutive HD patients from our dialysis center were examined with respect to shunt occlusion within the first 2 years after fistula creation and patient survival in a long-term follow-up (at least 16 years). We examined the presence of factor V, prothrombin, and MTHFR mutations using real-time fluorescence polymerase chain reaction. Furthermore, antithrombin (AT), protein C, protein S, and antiphospholipid antibodies (APL-Abs) were assessed.ResultsAmong the 70 patients, 32 had MTHFR mutations, 10 had heterozygous factor V Leiden mutations, 4 had prothrombin mutations, 4 had protein S deficiency, 2 had protein C deficiency, 9 had AT deficiency, and 14 had APL-Abs. 40 patients had shunt occlusion. TRFs were associated with a significantly increased risk for shunt thrombosis (P<0.02). Kaplan–Meier analysis with a log-rank test revealed significantly shorter survival in HD patients with TRFs (P<0.02). Cox regression analysis showed that the presence of TRFs (P<0.05; hazard ratio, 1.94; 95% CI: 1.07–3.56), but not early shunt occlusion, was associated with short patient survival.ConclusionsTRFs in hemodialysis patients have a strong impact on patient survival and early AV fistula failure; however, patient survival is not significantly affected by early shunt occlusion.

Effect of Dumbbell Exercise on Arteriovenous Fistula in Patients Undergoing Maintenance Haemodialysis: A Prospective Randomized Controlled Trial

Background: Arteriovenous fistulas (AVF) have been the main vascular accesses for haemodialysis patients, but the maintenance after maturation poses serious challenges. Arm exercises promote the maturation of AVFs. However, few studies have evaluated the effect of arm exercise on matured AVF and addressed the intervention for late fistula failure. Objectives: The study was conducted to explore the effect of dumbbell exercise on mature AVF. Methods: 86 participants undergoing haemodialysis with AVFs were randomized into the control group and experimental group. The experimental group held 6-pound dumbbells on non-dialysis days for 3 months, while the control group squeezed rubber balls. Results: For blood flow of draining vein (DV; primary outcome), the between-group effects, interaction effect and time effect showed significant differences. A significant increase in blood flow of DV was observed in the dumbbell group at the 3rd month (mean difference, 359.50 [111.90–829.05] mL/min; p = 0.001). The difference in blood flow of AVF proximal artery, blood flow of brachial artery, the diameter of DV and the incidence of adverse events at 3 months (secondary outcomes) between the 2 groups was insignificant. Conclusion: Prolonged training with arm exercises is essential for patients with AVFs though the fistula has matured. The designed dumbbell exercise is an economical, effective intervention to maintain the function of AVF, especially for patients with potential reduction of access blood flow and no percutaneous transluminal angioplasty indication.

Dynamic Banding (DYBAND) Technique for Symptomatic High-Flow Fistulae.

High flow rates may develop in arteriovenous fistula (AVF), resulting in clinical syndromes of steal, aneurysmal fistula, or high-output cardiac failure. Various techniques with varying success have been advocated to treat this difficult problem. We present a hemodynamically validated novel banding technique. We designed a computational fluid dynamic (CFD) model of the native high-flow AVF and tested various juxta-anastomotic venous diameters to determine the effect on AVF blood flow and pressure. We translated this principle in our banding technique, wherein adjustable banding was performed in conjunction with ultrasound-guided brachial artery flow measurement to determine the optimal band diameter. Polyurethane patch was used to fashion the adjustable band. Patient demographics, AVF flow parameters pre- and postintervention, operative intervention, and ultrasound follow-up data were collected prospectively. Our CFD testing demonstrated that the band diameter needed to achieve optimal distal blood pressure and preserve AVF flow depending on blood pressure, end capillary pressure, venous pressure, and vascular diameters. Five patients subsequently underwent dynamic banding of symptomatic high-flow AVF. Mean brachial artery blood flow rates pre- and postbanding were 2964 mL/min (confidence interval [CI]: 1487-4440 mL/min) and 1099 mL/min (CI: 571.7-1627 mL/min), respectively (P = .01). All patients had symptomatic improvement, and at a mean follow-up of 1 year, this benefit was sustained with no AVF thrombosis or loss. Adjustable dynamic band using ultrasound-guided brachial artery flow shows promising results in producing accurate AVF blood flow reduction with sustained efficacy in the short term for patients with symptomatic high-flow AVF.

Snuffbox fistula - a first-line approach to haemodialysis: A review.

To examine the feasibility of snuffbox arteriovenous fistula as a first option for haemodialysis. Snuffbox arteriovenous fistula is the most distal native anastomosis possible for haemodialysis access. It was described by Rassat et al. This systematic review evaluates all literature investigating the feasibility and efficiency of performing snuffbox arteriovenous fistula. PubMed, Cochrane Library and Google Scholar were systematically searched for all English articles related to snuffbox arteriovenous fistula. Included studies were appraised using relevant appraisal tools. Eleven papers were included, one prospective trial and the remaining being retrospective. Two trials compared snuffbox arteriovenous fistula to the standard Cimino-Brescia wrist fistula. Factors predicting success included vessel diameter, diabetes, age <70 years, male gender, palpable radial artery, central venous system patency and surgical technique. Patency rates ranged from 61% to 87% at 1-year follow-up and decreased to 36.3%-87% on longer duration follow-up. Ipsilateral radiocephalic fistula was successfully formed in 45%-100% of snuffbox arteriovenous fistula that failed (average of 73.5%). This is a systematic review investigating snuffbox arteriovenous fistula's efficacy. The current literature is scarce and of poor quality; however, it does reflect that, in the well-selected patient, snuffbox arteriovenous fistula is a good and valid option for first-line haemodialysis. It provides a long segment of vessel for needling and also spares the proximal vessels for future use. Ability to effectively convert to wrist fistula in the event of snuffbox arteriovenous fistula failure provides longevity to native haemodialysis access before prosthetic adjuncts are required. This review provides recommendation for well-constructed randomised controlled trials to help delineate snuffbox arteriovenous fistula efficacy and investigate factors that affect success of these fistulas.