Feasibility of Creation of an Endovascular Arteriovenous Fistula in Patients Undergoing Preoperative Vascular Mapping.

Background: The first endovascular arteriovenous fistula (endoAVF) device (WavelinQ), a novel percutaneous technique of AVF creation, was approved by the Food and Drug Administration in 2018 and has been placed in a small number of United States patients on hemodialysis. It is unknown how often patients with advanced CKD have vascular anatomy suitable for WavelinQ creation. The goal of this study was to determine the proportion of patients with vascular anatomy suitable for WavelinQ creation and to assess patient characteristics associated with such suitability. Methods: All patients referred for vascular access placement at a large academic medical center underwent standardized preoperative sonographic vascular mapping to assess suitability for an AVF. During a 2-year period (March 2019 to March 2021), we assessed the suitability of the vessels for creation of WavelinQ. We then compared the demographic characteristics, comorbidities, and vascular mapping measurements between patients who were or were not suitable for WavelinQ. Results: During the study period, 437 patients underwent vessel mapping. Of these, 51% of patients were eligible for a surgical AVF, and 32% were eligible for a WavelinQ AVF; 63% of those suitable for a surgical AVF were also suitable for a WavelinQ AVF. Patients with a vascular anatomy suitable for WavelinQ were younger (age 55±15 versus 60±14 years, P=0.01) but similar in sex, race, diabetes, hypertension, coronary artery disease, and peripheral artery disease. Conclusions: Among patients with CKD with vascular anatomy suitable for a surgical AVF, 63% are also suitable for a WavelinQ endoAVF. Older patients are less frequently suitable for WavelinQ.

Peritoneal Dialysis Catheter Placement: Percutaneous and Peritoneoscopic Techniques.

Chronic peritoneal dialysis (PD) is an underutilized renal replacement therapy in treating end-stage renal disease that has several advantages over hemodialysis. The success of continuous ambulatory PD is largely dependent on a functional long-term access to the peritoneal cavity. Several methods have been developed to place the PD catheter using both surgical and percutaneous techniques. The purpose of this article is to describe the percutaneous techniques using fluoroscopy guidance and peritoneoscope method. While fluoroscopic method uses fluoroscopy guidance and a guidewire to place the PD catheter, the peritoneoscopic technique utilizes a needlescope to directly visualize the peritoneal space to avoid adhesions and omentum during catheter placement. These percutaneous approaches are minimally invasive procedures that can be performed on an outpatient basis without the need for general anesthesia.

Why Peritoneal Dialysis is Underutilized in the United States: A Review of Inequities.

Given a choice, most patients with end-stage renal disease prefer home dialysis over in-center hemodialysis (HD). Peritoneal dialysis (PD) is a home dialysis method and offers benefits such as absence of central venous access and therefore preservation of veins, low cost, and decreased time per dialysis session, as well as convenience. Survival rate for patients on PD has increased to levels comparable to in-center HD. Despite endorsement by leaders in the medical field, professional societies, and those in government, PD has reached only 11% adoption among incident patients according to the 2019 United States Renal Data System Annual Data Report. This figure is dwarfed in comparison to rates as high as 79% in other countries. In addition, research has shown that inequities exist in PD access, which are most pronounced in rural, minority, and low-income regions as demonstrated by trends in regional PD supplies. To complicate things further, technique failure has been implicated as a major determinant of poor PD retention rates. The low initiation and retention rates of PD in the United States points to barriers within the healthcare system, many of which are in the early phases of being addressed.

Devices and Techniques for Percutaneous Creation of Dialysis Arteriovenous Fistulas.

Dialysis treatment for chronic kidney disease was first developed by Dr. Willem Kolff in 1943, and its availability began to grow in 1962 after which it has become a mainstay treatment for patients with chronic kidney disease. It is estimated that, in 2021, 15% of adults in the United States (∼37 million people) have chronic kidney disease, of which 661,000 individuals have renal failure, and 468,000 individuals require dialysis. There have been several advancements in dialysis treatment since its advent, most notably the creation of arteriovenous fistulas (AVFs) for venous access in 1966. In recent years, the U.S. Food and Drug Administration approved two new devices for AVF creation using a percutaneous approach. These are the WavelinQ (Becton Dickinson, New Jersey) and the Ellipsys (Avenu Medical, California) endovascular AVF (endoAVF) devices that use radiofrequency and thermal technologies, respectively, to create the AVF. Since the introduction of these technologies, several studies have shown that they are safe and effective, with favorable durability and low rate of serious adverse events. In this article, we will discuss these two devices and the techniques used for percutaneous creation of dialysis AVF as an alternative to traditional open surgical techniques.

Endovascular Management of Pelvic Trauma.

Major pelvic fractures result from high-energy trauma including traffic accidents and falls, which usually leads to multiple injuries complicating the patient's management. Management of these patients requires a coordinated multidisciplinary approach. Transcatheter embolization is a minimally invasive and effective technique to control massive hemorrhage and can be performed using a variety of embolic agents. It has become an accepted first-line management option for retroperitoneal bleeds in many centers. In this article, the indications for endovascular management of hemorrhage from pelvic trauma, the various embolization techniques, and potential complications will be discussed.

Comparative Study on the Outcomes of Elective-Start versus Urgent-Start Peritoneal Dialysis Catheter Placement.

The aim of this study is to compare the outcomes of the elective-start versus urgent-start use of peritoneal dialysis (PD) catheters using percutaneous radiologic or laparoscopic techniques. Patients having their first peritoneal dialysis catheter placed and used between January 2005 and January 2018 were identified, and their medical records were retrospectively reviewed. Two groups were identified: elective-start (n = 211) and urgent-start (n = 29). Patient's demographics were similar between the two groups with the exception of age, which was higher in the elective-start group. The catheter complication rates and catheter removal rates at 3 and 12 months, mean days-to-first complication, mean days-to-catheter removal, and overall patient survival at 12 months were analyzed. Catheter complication rates at 3 and 12 months were similar between the two groups (27.8% and 48.9%, respectively, in the elective-start group versus 35.9% and 54.2%, respectively, in the urgent-start group, p=0.415). The catheter removal rates at 3 and 12 months were also similar between the two groups (p=0.088). Catheter leak was higher in the urgent-start group (13.8% versus 3.3%, respectively, p=0.011). There was no difference between the elective-start and the urgent-start groups in the mean days-to-first complication (95 vs 69, p=0.086), mean days-to-catheter removal (145 vs 127, p=0.757), and overall patient survival at 12 months (100% vs 97%, p=0.41). In conclusion, apart from catheter leak, there were similar rates of catheter complication and removal for PD catheter used for the elective-start compared to the urgent-start PD. Furthermore, the technique of placement did not affect the outcomes.

Psoas Muscle Density in Combination with Model for End-Stage Liver Disease Score Can Improve Survival Predictability in Transjugular Intrahepatic Portosystemic Shunts.

PURPOSE: To examine the role of psoas muscle density (PD) measurement before transjugular intrahepatic portosystemic shunt (TIPS) creation in predicting survival when combined with Model for End-stage Liver Disease (MELD) score. MATERIALS AND METHODS: The medical records of 241 patients with cirrhosis who underwent TIPS creation between June 2005 and June 2015 were retrospectively reviewed. The patients were divided into 2 groups: those with variceal bleeding (VB; n = 113) and those with volume overload (VO; n = 128). The study included 149 men (62%), and mean patient age was 56 years ± 9.6 (range 24-83). Mean MELD score before TIPS creation was 11.8 ± 5.7. A threshold sensitivity of pre-TIPS PD for the assessment of mortality was calculated and then correlated with survival after TIPS creation. Receiver operating characteristic curves comparing 12-month mortality were used to assess the improvement in survival predictability after TIPS creation when the PD threshold was combined with MELD score vs MELD score alone. RESULTS: Mean post-TIPS follow-up was 29.9 month ± 34.1 (range 1-3700 days). There was no significant difference in 3- or 12-month mortality rates between the VB and VO groups (32.7% vs 25.8% [P = .23] and 46% vs 46.1% [P = .99], respectively). The MELD score threshold for prediction of survival was 15 (P < .0001). There was no difference in the mean PD between VB and VO groups (34.2 HU ± 8.8 and 33.1 HU ± 10.3, respectively; P = .359). The increase in MELD score after TIPS creation was significant in both groups (VB, P = .0013; VO, P < .0001). The threshold of pre-TIPS PD for discrimination of survival was 29.4 HU (P < .0001), and PD measurements greater than this threshold were associated with a lower risk of mortality (hazard ratio, 0.27; 95% confidence interval, 0.13-0.57; P = .0006). Compared with the use of MELD score alone, the addition of PD measurement significantly increased the area under the curve from 0.61 to 0.68 (P = .0006). CONCLUSIONS: Measurement of PD improved overall survival predictability in patients with cirrhosis undergoing TIPS creation when used in conjunction with MELD score. The best survival outcome was observed in patients with MELD score < 15 in combination with PD > 29.4 HU.

Approaches for safe transarterial chemoembolization of multifocal hepatocellular carcinoma with retrograde flow in a retroportal artery.

We report a case of an 81-year-old woman with multifocal hepatocellular carcinoma who underwent transarterial chemoembolization. The patient had significant superior mesenteric artery (SMA) ostial stenosis, which led to retrograde flow in the retroportal artery to the SMA. The authors adopted several approaches to avoid potential nontarget embolization that might result from the change in the hemodynamics in the hepatoenteric arteries by initially stenting the SMA ostial stenosis as well as the use of the Surefire infusion system and balloon occlusion for delivery of chemoembolization material to tumors in the hepatic lobes. To our knowledge, the collective use of these approaches to avoid potential risks related to SMA ostial stenosis and retrograde flow in a retroportal artery has not been previously described in the literature.

Persistent Pulmonary Arteriovenous Malformations: Percutaneous Embolotherapy.

Pulmonary arteriovenous malformations (PAVM) are an uncommon entity that interventional radiologists may face in their clinical practice. Many of these lesions are treated successfully using endovascular techniques with satisfactory long-term results. However, some PAVMs respond poorly to initial interventional techniques. This article reviews the signs and symptoms of persistent PAVMs, illustrates different imaging modalities used to diagnose these lesions, and outlines mechanisms by which these lesions may persist. The article highlights techniques and embolic agents used for percutaneous transcatheter embolotherapy of persistent PAVMs and discuss the outcomes of these interventions.

Chemoembolization of Hepatocellular Carcinoma with Extrahepatic Collateral Blood Supply: Anatomic and Technical Considerations.

Transarterial chemoembolization (TACE) is considered a standard local-regional treatment for intermediate-stage hepatocellular carcinoma (HCC) and the most common bridging therapy. This treatment is offered to more than 70% of patients who are on the waiting list for liver transplantation in the United States. HCC typically receives its blood supply from the hepatic artery; however, it can recruit a parasitic supply from extrahepatic collateral (EHC) arteries. The development of an EHC arterial blood supply can interfere with the therapeutic efficacy of TACE and result in treatment failure and poor outcome. Cross-sectional imaging-specifically computed tomography and magnetic resonance imaging-has some limitations in depicting the presence or absence of an EHC arterial supply during the pre-TACE evaluation. Catheterization and angiography of every possible EHC artery during a routine TACE procedure would be time consuming and technically challenging and would not always be feasible. Therefore, the prediction of a potential EHC arterial supply on the basis of tumor location before, during, and after TACE is fundamental to achieving optimal therapeutic efficacy. To perform TACE through EHC arteries, special considerations are necessary to avoid potentially serious complications. The authors review the factors influencing the development of an EHC arterial blood supply to HCC and describe a systematic approach to enhance the ability to predict the presence of EHC arteries. They also describe the proper technique for TACE of each EHC artery and how to avoid potential technique-related complications. ©RSNA, 2017.

Does the type and size of Amplatzer vascular plug affect the occlusion time of pulmonary arteriovenous malformations?

PURPOSE: Occlusion time (OT) is an important factor in the treatment of pulmonary arteriovenous malformations (PAVMs) since it can lead to serious complications. The purpose of our study is to calculate the OT of Amplatzer vascular plug (AVP, St Jude Medical), and correlate it to the type of the device used (AVP or AVP 2) and the percent of device oversizing. Technical success rates and complications were also recorded. METHODS: We retrospectively studied a total of 19 patients with 47 PAVMs who received percutaneous transcatheter embolization therapy using either AVP or AVP 2. We recorded the location, type, feeding artery diameter, AVP device used, and OT of each PAVM. We correlated the percent of device oversizing and the type of AVP with the OT. We also studied the rate of persistence of PAVM for both devices. RESULTS: Forty-six (98%) of the PAVMs were simple. Device diameters ranged from 4.0-16.0 mm with device oversizing ranging between 14% and 120%. There was a statistically significant difference in the OT of AVP and AVP 2 (3 min 54 s vs. 5 min 30 s, P = 0.030). There was a weak positive correlation between OT and device oversizing for AVP (r=0.246, P = 0.324) and AVP 2 (r=0.261, P = 0.240). No major complications were identified. Immediate technical success rate was 100%. CONCLUSION: The use of AVP 2, and increase in device oversizing were not associated with reduction in the OT of PAVMs. There was no reported difference in safety between the two devices, and no major complications were noted.

Embolization of congenital intercostobronchial trunk-pulmonary artery fistula using Amplatzer vascular plugs.

We present the case of a 54-year-old male patient diagnosed with a right upper lobe lung cancer and was referred for resection. Positron emission tomography-computed tomography scan showed a prominent vascular structure in the right lung, suspicious for vascular malformation. A computed tomography angiography was done, demonstrating an intercostobronchial trunk-pulmonary artery fistula. There was also non-tapering dilated wandering pulmonary artery coursing through the right lower lung without any abnormal connection with pulmonary veins and were supplying normal lung parenchyma. Amplatzer vascular plugs were used for the treatment of the intercostobronchial trunk-pulmonary artery fistula. Our case highlights these very rare vascular anomalies, and their management.

Percutaneous Transhepatic Embolization of Bleeding Rectal Varices Using A New Embolic And Sclerotic Mixture Augmented By Amplatzer Vascular Plug 2.

We report a case of 59-year-old female with non-alcoholic-steato-hepatitis (NASH) induced cirrhosis, who presented with hematochezia. The patient had a history of bleeding esophageal varices treated with endoscopic variceal ligation (EVL). Colonoscopy showed large rectal varices which were the source of her lower gastrointestinal bleeding (LGIB). Since endoscopic treatment for LGIB are limited, and because the patient had portal vein thrombosis which contraindicated transjugular intrahepatic portosystemic shunt (TIPS), we performed percutaneous transhepatic embolization of her rectal varices using a new mixture of embolic and sclerotic agents, followed by Amplatzer plug 2 (AVP 2). To our knowledge, the use of this new mixture with the AVP 2 in the rectal varices treatment has not been previously published in literature. Our case provides an alternative treatment modality that can be used for rectal varices treatment, when TIPS and endoscopic management fails or is contraindicated.

Analysis of the Final DENALI Trial Data: A Prospective, Multicenter Study of the Denali Inferior Vena Cava Filter.

PURPOSE: To report the final 2-year data on the efficacy and safety of a nitinol retrievable inferior vena cava (IVC) filter for protection against pulmonary embolism (PE). MATERIALS AND METHODS: This was a prospective multicenter trial of 200 patients with temporary indications for caval filtration who underwent implantation of the Denali IVC filter. After filter placement, all patients were followed for 2 years after placement or 30 days after filter retrieval. The primary endpoints were technical success of filter implantation in the intended location and clinical success of filter placement and retrieval. Secondary endpoints were incidence of clinically symptomatic recurrent PE, new or propagating deep vein thrombosis (DVT), and filter-related complications including migration, fracture, penetration, and tilt. RESULTS: Filter placement was technically successful in 199 patients (99.5%). Filters were clinically successful in 190 patients (95%). The rate of PE was 3% (n = 6), with 5 patients having a small subsegmental PE and 1 having a lobar PE. New or worsening DVT was noted in 26 patients (13%). Filter retrieval was attempted 125 times in 124 patients and was technically successful in 121 patients (97.6%). The mean filter dwell time at retrieval was 200.8 days (range, 5-736 d). There were no instances of filter fracture, migration, or tilt greater than 15° at the time of filter retrieval or during follow-up. CONCLUSIONS: The Denali IVC filter exhibited high success rates for filter placement and retrieval while maintaining a low complication rate in this clinical trial.

Persistence of pulmonary arteriovenous malformations after successful embolotherapy with Amplatzer vascular plug: long-term results.

PURPOSE: We aimed to evaluate the frequency of persistence and complication rates of pulmonary arteriovenous malformations (PAVMs) treated with Amplatzer vascular plug (AVP) or Amplatzer vascular plug type 2 (AVP2). METHODS: We retrospectively reviewed a total of 22 patients with 54 PAVMs between June 2004 and June 2014. We included 12 patients with 35 PAVMs who received percutaneous embolization using AVP or AVP2 only without the use of any other embolic devices. The mean follow-up was 54±24.3 months (range, 31-97 months). The primary end-points of the study were the efficacy of embolotherapy, the increase in oxygen saturation, and the persistence of PAVM on follow-up. Secondary end point was the incidence of complications. RESULTS: The study included 10 female and two male patients with a mean age of 50.2±13.7 years (range, 21-66 years). All PAVMs had a simple angioarchitecture. The technical success of the procedure for PAVM occlusion was 100%. There was a significant increase in the oxygen saturation following embolotherapy (P < 0.0001). Follow-up computed tomography angiography revealed successful treatment in 34 PAVMs (97%) and failed treatment in one PAVM (3%). Twenty-three aneurysmal sacs (67%) showed complete disappearance. The failed treatment was due to persistence of PAVM caused by subsequent development of systemic reperfusion, which did not require further intervention. There were two minor complications but no major complications were encountered. CONCLUSION: Embolotherapy of PAVMs using AVP or AVP2 devices is safe and effective, with high technical success rate, low persistence and complication rates, and with excellent long-term results.

Treatment of Hypersplenism by Partial Splenic Embolization Through Gastric Collaterals.

We report a case of Chronic lymphocytic leukemia (CLL) with associated hypersplenism, that was referred to us for partial splenic embolization (PSE) as the patient was not a surgical candidate for splenectomy. Initially, we were not successful in catheterizing the splenic artery from the celiac trunk due to significant atherosclerotic disease. Therefore, we successfully managed to access the distal splenic artery through patent gastro-epiploic collateral circulation along the greater curvature of the stomach. Partial splenic embolization was successfully performed and resulted in improvement of the patient's peripheral blood cell count as well as 60-70% reduction in the size of the spleen on follow up. Our case highlights an alternative pathway for splenic artery embolization when catheterization of the splenic artery is not feasible. To our knowledge, the use of gastro-epiploic collaterals to embolize the spleen has not been previously reported in literature.

Comprehensive Imaging Review of the Superior Vena Cava.

The superior vena cava (SVC) is the largest central systemic vein in the mediastinum. Imaging (ie, radiography, computed tomography [CT], magnetic resonance [MR] venography, and conventional venography) plays an important role in identifying congenital variants and pathologic conditions that affect the SVC. Knowledge of the basic embryology and anatomy of the SVC and techniques for CT, MR imaging, and conventional venography are pivotal to accurate diagnosis and clinical decision making. Congenital anomalies such as persistent left SVC, partial anomalous pulmonary venous return, and aneurysm are asymptomatic and may be discovered incidentally in patients undergoing imaging evaluation for associated cardiac abnormalities or other indications. Familiarity with congenital abnormalities is important to avoid image misinterpretation. Acquired abnormalities such as intrinsic and extrinsic strictures, fibrin sheath, thrombus, primary neoplasms, and trauma can produce mild narrowing to complete occlusion, the latter leading to SVC syndrome. Each imaging modality plays a role in evaluation of the SVC, helping to determine the site, extent, and cause of pathologic conditions and guide appropriate management. Commonly performed interventional procedures for fibrin sheath and benign and malignant strictures include low-dose thrombolytic infusion, fibrin sheath disruption, venous angioplasty, and stent placement.

Incidentally Discovered Middle Mesenteric Artery In A Renal Donor.

The middle mesenteric artery is a very rare anomalous artery originating from the ventral surface of the abdominal aorta in-between the superior mesenteric artery and inferior mesenteric artery. We identified a middle mesenteric artery during abdominal computed tomographic angiography in a renal donor patient as a part of his work up. The middle mesenteric artery branched out into ileal and ileocolic arteries, supplying the terminal ileal loops as well as the cecum. The anomalous artery had no effect on patient's eligibility as a renal donor candidate.

Inferior vena cava filter penetration following Whipple surgical procedure causing ureteral injury.

We report a case of an indwelling inferior vena cava filter that penetrated the IVC wall after Whipple's pancreatico-duodenectomy procedure performed in a patient with ampullary carcinoma, resulting in right ureteral injury and obstruction with subsequent hydroureter and hydronephrosis. This was incidentally discovered on a computed tomography scan performed as routine follow up to evaluate the results of the surgery. We retrieved the inferior vena cava filter and placed a nephrostomy catheter to relieve the ureteral obstruction. Our case highlights the importance of careful inferior vena cava manipulation during abdominal surgery in the presence of an inferior vena cava filter, and the option of temporary removal of the filter to be placed again after surgery in order to avoid this complication, unless protection is required against clot migration during the surgical procedure.