Long-Term Results from the Pivotal Multicenter Trial of Ultrasound-Guided Percutaneous Arteriovenous Fistula Creation for Hemodialysis Access.

PURPOSE: To report the 5-year results from the Pivotal Multicenter Trial of Ultrasound-Guided Percutaneous Arteriovenous Fistula (pAVF) Creation for Hemodialysis Access. MATERIALS AND METHODS: The retrospective review of 107 intent-to-treat (ITT) patients from the pivotal trial provided a long-term follow-up population (LTP) of 85 patients with a median follow-up duration of 50 months (range, 12-60 months). Data evaluated in the LTP group were fistula maturation and usage, secondary procedures, and complications. The Kaplan-Meier analysis of primary patency, assisted primary patency, cumulative patency, and functional patency (time from 2-needle cannulation to abandonment) were performed for the ITT population. RESULTS: In the LTP, 99% (84 of 85) of fistulae were mature, with 99% (78 of 79) of patients requiring hemodialysis using their pAVF. Sustained fistula use (2-needle cannulation at the prescribed rate, 2 of 3 sessions) was achieved in 92% (78 of 85) of patients, with 7 patients not using their pAVF because they were not on dialysis (n = 4), were on peritoneal dialysis (n = 2), and refused to use fistula (n = 1). Fistula maintenance was required in 31.8% (27 of 85) of patients and included fistula dysfunction (21.2%), thrombosis (5.9%), cannulation injury (12.9%), and arm swelling (4.7%). The number of procedures performed per patient per year to maintain function and patency was 0.32 (91 of 288) for years 2-5. The cumulative patency rates were 89.5%, 88.4%, 88.4%, 85.6%, and 82.0% for years 1, 2, 3, 4, and 5, respectively. The functional patency was 91.8% at the end of the study. There were no major complications related to pAVF during the long-term follow-up. CONCLUSIONS: Percutaneous fistulae have provided clinically effective and durable access for hemodialysis with low complications. The continued use and evaluation of pAVF are warranted.

Optimal reperfusion strategy in acute high-risk pulmonary embolism requiring extracorporeal membrane oxygenation support: a systematic review and meta-analysis.

BACKGROUND: The optimal pulmonary revascularisation strategy in high-risk pulmonary embolism (PE) requiring implantation of extracorporeal membrane oxygenation (ECMO) remains controversial. METHODS: We conducted a systematic review and meta-analysis of evidence comparing mechanical embolectomy and other strategies, including systemic thrombolysis, catheter-directed thrombolysis or ECMO as stand-alone therapy, with regard to mortality and bleeding outcomes. RESULTS: We identified 835 studies, 17 of which were included, comprising 327 PE patients. Overall, 32.4% were treated with mechanical pulmonary reperfusion (of whom 85.9% had surgical embolectomy), while 67.6% received other strategies. The mortality rate was 22.6% in the mechanical reperfusion group and 42.8% in the "other strategies" group. The pooled odds ratio for mortality with mechanical reperfusion was 0.439 (95% CI 0.237-0.816) (p=0.009; I2=35.2%) versus other reperfusion strategies and 0.368 (95% CI 0.185-0.733) (p=0.004; I2=32.9%) for surgical embolectomy versus thrombolysis. The rate of bleeding in patients under ECMO was 22.2% in the mechanical reperfusion group and 19.1% in the "other strategies" group (OR 1.27, 95% CI 0.54-2.96; I2=7.7%). The meta-regression model did not identify any relationship between the covariates "more than one pulmonary reperfusion therapy", "ECMO implantation before pulmonary reperfusion therapy", "clinical presentation of PE" or "cancer-associated PE" and the associated outcomes. CONCLUSIONS: The results of the present meta-analysis and meta-regression suggest that mechanical reperfusion, notably by surgical embolectomy, may yield favourable results regardless of the timing of ECMO implantation in the reperfusion timeline, independent of thrombolysis administration or cardiac arrest presentation.

Research Priorities for Percutaneous Arteriovenous Fistula Creation in Patients with End-Stage Renal Disease: Proceedings and Recommendations from a Multidisciplinary Research Consensus Panel.

Recently developed endovascular techniques to create percutaneous arteriovenous fistulas are an alternative to surgical arteriovenous fistula creation, although there is currently a lack of high-level evidence regarding their creation, maturation, utilization, and long-term function. Recognizing this, the Society of Interventional Radiology Foundation sponsored a Research Consensus Panel and Summit for the prioritization of a research agenda to identify and address the gaps in current knowledge.

Going Home: Access for Home Modalities.

The cost and health burden of ESRD continues to increase globally. Total Medicare expenditure on dialysis has increased from 229 million USD in 1973 to 35.4 billion USD in 2016. Dialysis access can represent almost a tenth of these costs. Central venous catheters have been recognized as a significant factor driving costs and mortality in this population. Home dialysis, which includes peritoneal dialysis and home hemodialysis, is an effective way of reducing costs related to renal replacement therapy, reducing central venous catheter usage and in many cases improving the clinical and psychosocial aspects of patients' health. Addressing access-related issues for peritoneal dialysis, urgent-start peritoneal dialysis and home hemodialysis can have impact on the success of home dialysis. This article reviews issues related to dialysis access for home therapies.

Survey of non-tunneled temporary hemodialysis catheter clinical practice and training.

BACKGROUND: Nephrologists are placing fewer non-tunneled temporary hemodialysis catheters. Requiring competence for nephrology fellow graduation is controversial. METHODS: Anonymous, online survey of all graduates from a single, military nephrology training program (n = 81; 1985-2017) and all US Nephrology program directors (n = 150). RESULTS: Graduate response and completion rates were 59% and 100%, respectively; 93% agreed they had been adequately trained; 58% (26/45) place non-tunneled temporary hemodialysis catheters, independent of academic practice or time in practice, but 12/26 did ⩽5/year and 23/26 referred some or all. The most common reason for continuing non-tunneled temporary hemodialysis catheter placement was that it is an essential emergency procedure (92%). The single most significant barrier was time to do the procedure (49%). Program director response and completion rates were 50% and 79%, respectively. The single most important barrier to fellow competence was busyness of the service (36%), followed by disinterest (21%); 55% believed that non-tunneled temporary hemodialysis catheter insertion competence should be required, with 81% indicating it was an essential emergency procedure. The majority of graduates and program directors agreed that simulation training was valuable; 76% of programs employ simulation. Graduates who had simulation training and program directors with ⩽20 years of practice were significantly more likely to agree that simulation training was necessary. CONCLUSION: Of the graduate respondents from a single training program, 58% continue to place non-tunneled temporary hemodialysis catheters; 55% of program directors believe non-tunneled temporary hemodialysis catheter procedural competence should be required. Graduates who had non-tunneled temporary hemodialysis catheter simulation training and younger program directors consider simulation training necessary. These findings should be considered in the discussion of non-tunneled temporary hemodialysis catheter curriculum requirements.

Survey of Kidney Biopsy Clinical Practice and Training in the United States.

BACKGROUND AND OBJECTIVES: Practicing clinical nephrologists are performing fewer diagnostic kidney biopsies. Requiring biopsy procedural competence for graduating nephrology fellows is controversial. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: An anonymous, on-line survey of all Walter Reed training program graduates (n=82; 1985-2017) and all United States nephrology program directors (n=149; August to October of 2017), regarding kidney biopsy practice and training, was undertaken. RESULTS: Walter Reed graduates' response and completion rates were 71% and 98%, respectively. The majority felt adequately trained in native kidney biopsy (83%), transplant biopsy (82%), and tissue interpretation (78%), with no difference for ≤10 versus >10 practice years. Thirty-five percent continued to perform biopsies (13% did ≥10 native biopsies/year); 93% referred at least some biopsies. The most common barriers to performing biopsy were logistics (81%) and time (74%). Program director response and completion rates were 60% and 77%. Seventy-two percent cited ≥1 barrier to fellow competence. The most common barriers were logistics (45%), time (45%), and likelihood that biopsy would not be performed postgraduation (41%). Fifty-one percent indicated that fellows should not be required to demonstrate minimal procedural competence in biopsy, although 97% agreed that fellows should demonstrate competence in knowing/managing indications, contraindications, and complications. Program directors citing ≥1 barrier or whose fellows did <50 native biopsies/year in total were more likely to think that procedural competence should not be required versus those citing no barriers (P=0.02), or whose fellows performed ≥50 biopsies (P<0.01). CONCLUSIONS: Almost two-thirds of graduate respondents from a single military training program no longer perform biopsy, and 51% of responding nephrology program directors indicated that biopsy procedural competence should not be required. These findings should inform discussion of kidney biopsy curriculum requirements.

The Pivotal Multicenter Trial of Ultrasound-Guided Percutaneous Arteriovenous Fistula Creation for Hemodialysis Access.

PURPOSE: To evaluate safety and efficacy of arteriovenous fistulas (AVFs) created with a thermal resistance anastomosis device. MATERIALS AND METHODS: A prospective single-arm trial at 5 sites enrolled 107 patients. Patients underwent ultrasound (US)-guided anastomosis creation between the proximal radial artery and perforating vein with the Ellipsys Vascular Access System (Avenu Medical, Inc, San Juan Capistrano, California) followed by separate maturation procedures. Primary endpoints were brachial artery flow volume ≥ 500 mL/min and target vein diameter ≥ 4 mm in > 49% of patients and absence of device-related complications at 90 days. RESULTS: AVFs with fused anastomoses were created in 95% (102/107) of patients. Maturation procedures included anastomotic balloon dilation in 72% (77/107), brachial vein embolization in 32% (34/107), cubital vein ligation in 31% (33/107), and surgical transposition in 26% (28/107) of patients. Primary flow and diameter endpoints were achieved in 86.0% (92/107) of patients, exceeding performance goal of 49% (P < .0001). No major adverse events were attributed to the device. Cumulative patency was 91.6%, 89.3%, and 86.7% at 90 days, 180 days, and 360 days. Target dialysis veins were cephalic, basilic, and brachial veins in 74% (73/99), 24% (24/99), and 2% (2/99) of patients. Two-needle dialysis was achieved in 88% (71/81) of patients on hemodialysis at a mean 114.3 days ± 66.2. Functional patency was 98.4%, 98.4%, and 92.3% at 90 days, 180 days, and 360 days. CONCLUSIONS: The Ellipsys® Vascular Access System met primary safety and efficacy endpoint goals in the US pivotal trial.

Left Ventricular Mechanical Support with the Impella during Extracorporeal Membrane Oxygenation.

Background: Venoarterial extracorporeal membrane oxygenation (ECMO) provides systemic arterial support without directly unloading the left heart, which causes an elevated left ventricular (LV) pressure. The aim of the present study was to investigate the adjunctive application of the Impella device for LV unloading in patients during ECMO. Methods: This retrospective cohort study included patients who received Impella support in addition to venoarterial ECMO between April 2012 and December 2015. ECMO cannulation was performed peripherally or centrally, while the Impella device was surgically inserted into the femoral artery or the right axillary artery. Results: Among 62 patients, 10 (16.1%) received an Impella device during ECMO support. Following Impella support, right atrial pressure improved from a median of 18 (IQR, 14-24) mmHg to 13 (IQR, 10-15) mmHg and pulmonary wedge pressure improved from 30 (IQR, 26-35) mmHg to 16 (IQR, 12-19) mmHg in all the patients (p value < 0.001). Follow-up transthoracic echocardiograms (n = 6) showed a median decrease of 0.8 cm in LV end-diastolic volume (p value = 0.021). There were 5 (50%) in-hospital deaths due to sustained brain injury (n = 3) and refractory cardiogenic shock (n = 2). The remaining 5 patients were discharged and successfully bridged to more permanent LV assist device (n = 2) or heart transplantation (n = 3). Conclusion: The findings of the present study indicate that the application of the Impella device during ECMO support is effective in LV unloading and confers optimal hemodynamic support.

Imaging and Peritoneal Dialysis Catheters.

The placement of a peritoneal dialysis (PD) catheter by interventionalists demands not only procedural skill but also an ability to decipher real-time ultrasonographic and fluoroscopic images. In this article, we discuss how imaging assists in PD placement and recognition of complications. To aid this endeavor, we have provided images and video clips that should assist interventionalists. Compared with the fluoroscopic technique, peritoneoscopic PD catheter placement provides direct visual imaging to also aid placement of the initial trocar and the peritoneal catheter.

Extracorporeal Membrane Oxygenation in Massive Pulmonary Embolism.

BACKGROUND: Extracorporeal Membrane Oxygenation (ECMO) has been suggested for cardiopulmonary support in patients with massive pulmonary embolism (PE) refractory to other treatment or as bridging to embolectomy. The survival benefit from ECMO in patients with massive PE remains unclear. METHODS: Here, we describe 5 cases in which ECMO was used as cardiopulmonary support following massive near-fatal pulmonary embolism. RESULTS: The overall mortality in patients with massive PE that received ECMO support was 40%. Death occurred secondary to ECMO-related complication in one case and due to inability to maintain adequate cerebral perfusion despite ECMO support in the second case. CONCLUSIONS: ECMO can be considered as a treatment modality for patients with massive PE.

Extracorporeal membrane oxygenation in transcatheter aortic valve replacement.

Background Patients undergoing transcatheter aortic valve replacement can experience severe perioperative complications leading to hemodynamic instability and death. Venoarterial extracorporeal membrane oxygenation can be used to provide cardiorespiratory support during this time. Methods From 2012 to 2015, of 247 patients who underwent transcatheter aortic valve replacement, 6 (2.42%) required extracorporeal membrane oxygenation support. Their mean age was 82 ± 7.4 years, mean Society of Thoracic Surgeons score was 9.4 ± 6.6, and mean aortic gradient was 28.3 ± 12 mm Hg. Rescue extracorporeal membrane oxygenation was required for hemodynamic instability due to ventricular fibrillation ( n = 1), respiratory failure ( n = 1), left ventricular wall rupture ( n = 2), and aortic annulus rupture ( n = 1). In one patient, prophylactic extracorporeal membrane oxygenation was required due to advanced heart failure. Additional procedures included valve-in-valve implantation ( n = 1), conversion to an open procedure ( n = 3), and intraaortic balloon pump insertion ( n = 1). Results The median hospital stay was 20 days. There were 2 hospital deaths in patients whose hospital course was complicated by left ventricular wall rupture or aortic annulus rupture with resulting tamponade. Among the 4 survivors, one required continuous ventilator support following discharge, and 3 experienced no major complications during the first month after discharge. Conclusions Extracorporeal membrane oxygenation can be considered a viable option for high-risk patients undergoing transcatheter aortic valve replacement and those who develop cardiac complications following this procedure and require cardiorespiratory support.

Thrombectomy using suction filtration and veno-venous bypass: single center experience with a novel device.

OBJECTIVES: To describe the first single center experience with a novel aspiration thrombectomy device. BACKGROUND: The appearance of inferior vena cava or right-sided intracardiac thrombus may prompt consideration of percutaneous thrombectomy as a method to prevent new or worsening pulmonary embolism (PE). The AngioVac is a novel thrombectomy device composed of a cannula and extracorporeal circuit with filter for pump-assisted removal of intravascular debris which is coupled with a reinfusion catheter for return of blood to the patient. The device has been approved by the United States Food and Drug Administration since 2009. This report represents the first significant case series describing its use, feasibility and outcomes in evacuating large caval thrombi or intracardiac masses in PE. METHODS: This is a retrospective analysis of patient and case characteristics and in-hospital clinical outcomes of AngioVac thrombectomy in 14 consecutive patients treated between April 2010 and July 2013 at our institution. RESULTS: Fourteen consecutive patients (mean age 50, 64% female) underwent 15 AngioVac procedures over 40 months. Indications included intracardiac mass (73%), acute PE (33%), and caval thrombus (73%). Four patients (27%) were in shock at the start of the procedure. Peri-procedure mortality was 0% and in-hospital mortality was 13% at a mean follow-up of 23 days. There were no pulmonary hemorrhages, strokes or myocardial infarctions. Though 73% had a post procedural drop in hematocrit, only two bleeding events were related to access site and required a transfusion. CONCLUSIONS: AngioVac thrombectomy is feasible in critically ill patients with acute DVT or PE and large caval thrombi or intracardiac masses.

Structural barriers at the workplace for employees with vision and locomotor disabilities in New Delhi, India.

BACKGROUND: India, a signatory to the United Nations Convention on the Rights of Persons with Disabilities (UNCRPD), has 2.21% of people with disabilities to the total population of which 26% are employed (Census 2011 and 2001). Accessibility was introduced for the first time in 1995 under The Persons with Disabilities (Equal Opportunities, Protection of Rights and Full Participation) Act. Article 9 of UNCRPD promotes barrier-free environment on an equal basis with others. Despite the legislation and the UN convention, structural barriers continue to be one of the largest barriers posing concern for PwDs at their workplace. OBJECTIVE: To identify various physicall barriers limiting accessibility of PWDs in the formal sector in Delhi. METHOD: Quantitative descriptive research design. Random sample was drawn. RESULT: Structural barriers create difficulty in accessing basic amenities such as canteens, toilets etc. CONCLUSION: Disability is a human rights issue. An employee with disability is entitled to dignified life. Effective implementation of Article 9 and 27 of UNCRPD will pave a way for removing structural barriers at workplace.

The Massachusetts General Hospital Pulmonary Embolism Response Team (MGH PERT): creation of a multidisciplinary program to improve care of patients with massive and submassive pulmonary embolism.

New and innovative tools have emerged for the treatment of massive and submassive pulmonary embolism (PE). These novel treatments, when considered alongside existing therapy, such as anticoagulation, systemic intravenous thrombolysis, and open surgical pulmonary embolectomy, have the potential to improve patient outcomes. However, data comparing different treatment modalities are sparse, and guidelines provide only general advice for their use. Treatment decisions rest on clinician expertise and institutional resources. Because various medical and surgical specialties offer different perspectives and expertise, a multidisciplinary approach to patients with massive and submassive PE is required. To address this need, we created a novel multidisciplinary program - the Massachusetts General Hospital (MGH) Pulmonary Embolism Response Team (PERT) - which brings together multiple specialists to rapidly evaluate intermediate- and high-risk patients with PE, formulate a treatment plan, and mobilize the necessary resources to provide the highest level of care. Development of a clinical, educational, and research infrastructure, as well as the creation of a national PERT consortium, will make our experience available to other institutions and serve as a platform for future studies to improve the care of complex patients with massive and submassive PE.

Successful treatment of severe carbamazepine toxicity with 5% albumin-enhanced continuous venovenous hemodialysis.

Carbamazepine overdose is a common, toxic ingestion, manifesting as central nervous system (CNS) and respiratory depression. Carbamazepine is highly protein bound with a large volume of distribution and, therefore, inefficiently removed by conventional hemodialysis. We describe the successful use of continuous venovenous hemodialysis (CVVHD) with 5% albumin enhanced dialysate in a 31-year-old female who developed CNS depression, hypotension and respiratory failure, requiring mechanical ventilation, after an intentional ingestion of approximately 10 g of extended release carbamazepine, Tegretol CR(®). The peak drug level was 26 mcg/ml, therapeutic range 8-12 mcg/ml, with toxicity often developing a level above 15 mcg/ml. Normal half-life of drug elimination is 35-60 h in carbamazepine naïve patients. In contrast, with albumin-enhanced dialysis, we observed a drug half-life of 18 h. She was extubated on day two and was transferred to inpatient psychiatry by day 3 without significant neurologic sequelae. In vitro studies have been done with bovine blood demonstrating significant carbamazepine removal using CVVHD with albumin-enhanced dialysate. There has been very limited experience using albumin-enhanced CVVHD in an adult patient with carbamazepine toxicity.

Minimally invasive fluoroscopic percutaneous peritoneal dialysis catheter salvage.

BACKGROUND: Peritoneal dialysis catheter (PDC) dysfunction can often be treated fluoroscopically by manipulation with wire, balloon or stiff stylet, saving surgical intervention for refractory cases. We describe an enhanced percutaneous approach to PDC salvage that can lead to a more definitive intervention and salvage for cases refractory to fluoroscopic manipulation. METHODS: In five cases of PD catheter malfunction, the deep cuff was dissected free after a 0.035 hydrophilic wire was passed into the peritoneum through the PDC. Only the intraperitoneal portion of the PDC was explanted. The PDC was cleared of obstruction and omentum. The intraperitoneal portion of the PDC was reimplanted over wire via a peel-away sheath and the deep cuff sutured. RESULTS: Omental entrapment was present in three of five patients and fibrin occlusion in four of the five cases. All catheters were repaired successfully by the described technique. Post procedure, 3-5 days of lower volume, recumbent PD exchanges were performed prior to full-dose PD. No perioperative complications or leaks were noted. All PDCs were patent at 6 months. One patient required laparoscopy for recurrent omental wrapping 3 months post intervention. CONCLUSIONS: PDC salvage in this manner is a cost-effective alternative to laparoscopic repair of PDCs failing catheter manipulation. The infection barrier afforded by the original superficial cuff and subcutaneous tunnel is maintained. PD can be resumed immediately. Only refractory cases need laparoscopy. This procedure allows for a more definitive correction of catheter migration and obstruction, avoids placement of a new PDC or temporary hemodialysis, is cost-effective and expands percutaneous options for dysfunctional PD catheters.

GuideLiner mother-and-child guide catheter extension: a simple adjunctive tool in PCI for balloon uncrossable chronic total occlusions.

OBJECTIVES: To investigate the use of the GuideLiner "mother-and-child" guide catheter extension system as a simple solution to facilitate initial device delivery in balloon uncrossable chronic total occlusions (CTOs) undergoing percutaneous coronary intervention (PCI). BACKGROUND: During PCIs for CTO lesions, an important reason for procedural failure is the inability to deliver a balloon or microcatheter across the lesion. METHODS: We retrospectively accessed our interventional registry for 07/01/2010 to 03/21/2012 and extracted data on all CTO lesions involving GuideLiner catheter use. Cine review was performed to identify cases where a guidewire had crossed the CTO and the use of a GuideLiner catheter facilitated initial device delivery. RESULTS: We identified 28 patients that underwent PCI for CTO with a GuideLiner catheter used to assist initial balloon or microcatheter advancement across the culprit lesion. Mean overall CTO length was 26.3 ± 18.1 mm. The GuideLiner catheter was successful in delivering a small balloon to the CTO lesion in 85.7% of cases (24/28). A single CTO PCI resulted in a distal guidewire perforation, but there was no hemodynamic compromise or pericardial effusion and the patient was discharged the next day. Overall procedural success in these selected cases (where a guidewire had already crossed the CTO) was 89.3% (25/28). CONCLUSIONS: The GuideLiner mother-and-child catheter is a simple, safe and efficacious adjunctive device for difficult CTO PCIs where despite standard measures it is not possible to deliver an initial balloon or microcatheter across the occluded segment.

Percutaneous closure of left ventricular pseudoaneurysm.

The risk of rupture of a left ventricular (LV) pseudoaneurysm ranges from 30% to 45% in the first year. Open surgical repair carries high mortality related to anatomic complexity and patient comorbidities. Percutaneous closure may offer a viable alternative to surgical intervention in this cohort. Herein, we describe 3 unique cases of transcatheter LV pseudoaneurysm closure.