A Case of Ischemic Monomelic Neuropathy following Endovascular Arteriovenous Fistula Creation and Assisted Maturation.

Dialysis access steal syndrome (DASS) is a phenomenon known to occur following creation of an arteriovenous fistula or arteriovenous graft. The clinical presentation of DASS is characterized by symptoms of limb ischemia due to diversion of arterial flow from the distal extremity. Ischemic monomelic neuropathy (IMN) is a rare subtype of DASS classically described as an acute, isolated presentation of peripheral neuropathy following dialysis access creation. Although the underlying pathophysiology is not entirely understood, the clinical manifestation of IMN is often described as severe distal limb pain that progresses to motor and sensory defects. The onset of IMN may occur immediately following dialysis access creation or intervention. Here, we present a case of IMN following assisted maturation of an endovascular fistula.

Combined Transjugular Intrahepatic Portosystemic Shunt Plus Variceal Obliteration versus Transjugular Intrahepatic Portosystemic Shunt Alone for the Management of Gastric Varices: Comparative Single-Center Clinical Outcomes.

PURPOSE: To compare the safety and clinical outcomes of combined transjugular intrahepatic portosystemic shunt (TIPS) plus variceal obliteration to those of TIPS alone for the treatment of gastric varices (GVs). MATERIALS AND METHODS: A single-center, retrospective study of 40 patients with bleeding or high-risk GVs between 2008 and 2019 was performed. The patients were treated with combined therapy (n = 18) or TIPS alone (n = 22). There were no significant differences in age, sex, model for end-stage liver disease score, or GV type between the groups. The primary outcomes were the rates of GV eradication and rebleeding. The secondary outcomes included portal hypertensive complications and hepatic encephalopathy. RESULTS: The mean follow-up period was 15.4 months for the combined therapy group and 22.9 months for the TIPS group (P = .32). After combined therapy, there was a higher rate of GV eradication (92% vs 47%, P = .01) and a trend toward a lower rate of GV rebleeding (0% vs 23%, P = .056). The estimated rebleeding rates were 0% versus 5% at 3 months, 0% versus 11% at 6 months, 0% versus 18% at 1 year, and 0% versus 38% at 2 years after combined therapy and TIPS, respectively (P = .077). There was no difference in ascites (13% vs 11%, P = .63), hepatic encephalopathy (47% vs 55%, P = .44), or esophageal variceal bleeding (0% vs 0%, P > .999) after the procedure between the groups. CONCLUSIONS: The GV eradication rate is significantly higher after combined therapy, with no associated increase in portal hypertensive complications. This translates to a clinically meaningful trend toward a reduction in GV rebleeding. The value of a combined treatment strategy should be prospectively studied in a larger cohort to determine the optimal management of GVs.

Immediate postoperative inferior vena cava stenting to improve hepatic venous outflow following orthotopic liver transplantation.

Orthotopic liver transplantation can be a surgically complex undertaking, with hepatic venous outflow obstruction occurring at a rate of 1%-6% due to inferior vena cava (IVC) torsion, compression, or anastomotic stenosis. In this report, we present 2 cases of immediate postoperative hepatic venous outflow obstruction in the setting of Budd-Chiari syndrome successfully treated with immediate IVC stenting. Although IVC stenting has been reported for management of long-term IVC anastomotic stenosis after orthotopic liver transplantation, use of stenting to address immediate postoperative caval outflow obstruction is less commonly described. We describe the potential utility of immediate stenting to improve outflow from the transplanted liver and highlight the value of this approach in addressing early postsurgical IVC pathology.

High Incidence of Hepatic Encephalopathy After Viatorr Controlled Expansion Transjugular Intrahepatic Portosystemic Shunt Creation.

BACKGROUND: The Viatorr Controlled Expansion (VCX) stent-graft was designed to mitigate hepatic encephalopathy (HE) after transjugular intrahepatic portosystemic shunt (TIPS) creation. AIMS: To determine the incidence and degree of HE after VCX TIPS. METHODS: Thirty-three patients (M:F 17:16, mean age 58 years, mean MELD score 12) who underwent VCX TIPS between 2018 and 2019 were retrospectively studied. 11/33 (33%) patients had medically controlled pre-TIPS HE. TIPS indications included variceal hemorrhage (n = 12, 30%) and ascites (n = 21, 70%). Measured outcomes were post-TIPS HE (overall, recurrent, de novo) graded using the West Haven system, time-to-HE occurrence, HE-related hospitalization rate, and TIPS reduction rate. RESULTS: VCX TIPS were 8 mm in 28/33 (85%) and 10 mm in 5/33 (15%). Mean final portosystemic pressure gradient was 6 mmHg. Cumulative HE incidence post-TIPS was 61% (20/33). 1-, 3-, 6-, and 12-month HE rates were 24%, 30%, 53%, and 61% over 247-day median follow-up. Median time-to-HE was 180 days. HE grades spanned grade 1 (n = 6), grade 2 (n = 8), and grade 3 (n = 6); 9 and 11 cases were recurrent and de novo HE, respectively. Medication non-compliance/infection was implicated in HE in 9/20 (45%) cases. Medical therapy addressed HE in 18/20 (90%) cases; however, HE still resulted in 39 hospitalizations among 13 patients, and median time to first hospitalization was 75 days. Shunt reduction was necessary in 2 (10%) cases of medically refractory HE. CONCLUSIONS: The incidence of HE after VCX TIPS is high. Though HE symptoms may be medically controlled, hospitalization rates are high, and shunt reduction may be necessary.

Emergent Percutaneous Nephrostomy for Pyonephrosis: A Primer for the On-Call Interventional Radiologist.

Pyonephrosis is gross accumulation of pus within an obstructed renal collecting system that, if left untreated, can lead to potentially fatal septic shock. Treatment requires urgent decompression coupled with systemic antibiotics. Percutaneous nephrostomy (PCN) placement, first described in 1976 for the treatment of pyonephrosis, is now widely utilized for emergent decompression in these patients. When performed by an experienced interventional radiologist, PCN is a safe procedure with technical success rates of over 96 to 99%. This article will address the clinical presentation of pyonephrosis, and will discuss the indications, technique, complications, and outcomes of emergent PCN placement. Additionally, the expanded indications for PCN placement in nonemergent scenarios will also be described.

Percutaneous Gastrostomy Tube Placement: Recognizing When Things Go Wrong.

Percutaneous radiologic gastrostomy is a commonly performed, minimally invasive procedure for long-term enteral access in patients with a variety of conditions. Compared with other methods, it is less invasive, less costly, and safe, with a high technical success rate. The risk of complications is low, and most require only conservative management. Early, accurate diagnosis of more severe complication is crucial, as these may require prompt intervention. Therefore, radiologists should understand the imaging features, clinical presentation, and management of gastrostomy-related complications. This article will review the indications for long-term enteral access, discuss the available methods, summarize the percutaneous radiologic technique, and highlight the associated complications from gastrostomy placement.

Hemolytic Anemia following Stent-Graft Transjugular Intrahepatic Portosystemic Shunt Creation.

Transjugular intrahepatic portosystemic shunt (TIPS) creation is a minimally invasive technique aimed at managing the complications of portal hypertension. Initially performed in the setting of variceal bleeding, the role of TIPS has expanded to treatment of medically refractory ascites, portal hypertensive gastropathy, hepatic hydrothorax, Budd-Chiari syndrome, portal vein thrombus, and hepatorenal syndrome. Potential complications from TIPS are well documented, and include hepatic encephalopathy, hepatic failure, and TIPS dysfunction. Hemolytic anemia is a lesser known complication related to TIPS creation. In this article, a case of hemolytic anemia following TIPS creation using a Viatorr stent-graft in described.

Retrievable inferior vena cava filters in neurosurgical patients: Retrieval rates and clinical outcomes.

OBJECTIVE: To assess inferior vena cava (IVC) filter retrieval rates and clinical outcomes in neurosurgical patients and to determine patient characteristics associated with filter retrieval. PATIENTS AND METHODS: This single-center retrospective study included 204 consecutive neurosurgical patients (120 men, 84 women; mean age 60 ± 13 years) who underwent retrievable IVC filter insertion between 1/2011-9/2013. Institutional IVC filter database review was used to identify demographic and clinical data, indication for IVC filtration, and IVC filter type. Patients were followed clinically by the neurosurgical, hematology, and interventional radiology services until removal or conversion to a permanent device. Measured outcomes included filter retrieval rates and parameters associated with device removal. RESULTS: The majority of filters were placed for venous thromboembolism (200/204, 98%). Of 204 filters, 38(19%) were retrieved at median 186 days post-placement (range 3-665 days), 112(55%) converted to permanent devices, 44(22%) patients were deceased, and 10(5%) patients were lost to follow-up after transfer to an outside healthcare facility. Patients with subarachnoid hemorrhage (18% vs. 35%, p = 0.025) and malignancy (5% vs. 25%, p = 0.009) were less likely to have filters removed. Filter type (p = 0.475), gender (p = 0.221), neurosurgical procedure (p = 0.639), and insurance status (p = 0.207) did not demonstrate a significant association with filter retrieval. CONCLUSION: IVC filter retrieval rates in neurosurgical patients are low despite tracking patients clinically in a multidisciplinary setting. Those neurosurgical patients with intracranial hemorrhage or malignancy requiring IVC filters have a lower likelihood of filter retrieval and may benefit from use of permanent devices.

Alternative treatment for bleeding peristomal varices: percutaneous parastomal embolization.

PURPOSE: To describe how peristomal varices can be successfully embolized via a percutaneous parastomal approach. METHODS: The medical records of patients who underwent this procedure between December 1, 2000, and May 31, 2008, were retrospectively reviewed. Procedural details were recorded. Median fluoroscopy time and bleeding-free interval were calculated. RESULTS: Seven patients underwent eight parastomal embolizations. The technical success rate was 88 % (one failure). All embolizations were performed with coils combined with a sclerosant, another embolizing agent, or both. Of the seven successful parastomal embolizations, there were three cases of recurrent bleeding; the median time to rebleeding was 45 days (range 26-313 days). The remaining four patients did not develop recurrent bleeding during the follow-up period; their median bleeding-free interval was 131 days (range 40-659 days). CONCLUSION: This case review demonstrated that percutaneous parastomal embolization is a feasible technique to treat bleeding peristomal varices.

Transcriptional profiling of Bacillus anthracis during infection of host macrophages.

The interaction between Bacillus anthracis and the mammalian phagocyte is one of the central stages in the progression of inhalational anthrax, and it is commonly believed that the host cell plays a key role in facilitating germination and dissemination of inhaled B. anthracis spores. Given this, a detailed definition of the survival strategies used by B. anthracis within the phagocyte is critical for our understanding of anthrax. In this study, we report the first genome-wide analysis of B. anthracis gene expression during infection of host phagocytes. We developed a technique for specific isolation of bacterial RNA from within infected murine macrophages, and we used custom B. anthracis microarrays to characterize the expression patterns occurring within intracellular bacteria throughout infection of the host phagocyte. We found that B. anthracis adapts very quickly to the intracellular environment, and our analyses identified metabolic pathways that appear to be important to the bacterium during intracellular growth, as well as individual genes that show significant induction in vivo. We used quantitative reverse transcription-PCR to verify that the expression trends that we observed by microarray analysis were valid, and we chose one gene (GBAA1941, encoding a putative transcriptional regulator) for further characterization. A deletion strain missing this gene showed no phenotype in vitro but was significantly attenuated in a mouse model of inhalational anthrax, suggesting that the microarray data described here provide not only the first comprehensive view of how B. anthracis survives within the host cell but also a number of promising leads for further research in anthrax.

Transcriptional profiling of the Bacillus anthracis life cycle in vitro and an implied model for regulation of spore formation.

The life cycle of Bacillus anthracis includes both vegetative and endospore morphologies which alternate based on nutrient availability, and there is considerable evidence indicating that the ability of this organism to cause anthrax depends on its ability to progress through this life cycle in a regulated manner. Here we report the use of a custom B. anthracis GeneChip in defining the gene expression patterns that occur throughout the entire life cycle in vitro. Nearly 5,000 genes were expressed in five distinct waves of transcription as the bacteria progressed from germination through sporulation, and we identified a specific set of functions represented within each wave. We also used these data to define the temporal expression of the spore proteome, and in doing so we have demonstrated that much of the spore's protein content is not synthesized de novo during sporulation but rather is packaged from preexisting stocks. We explored several potential mechanisms by which the cell could control which proteins are packaged into the developing spore, and our analyses were most consistent with a model in which B. anthracis regulates the composition of the spore proteome based on protein stability. This study is by far the most comprehensive survey yet of the B. anthracis life cycle and serves as a useful resource in defining the growth-phase-dependent expression patterns of each gene. Additionally, the data and accompanying bioinformatics analyses suggest a model for sporulation that has broad implications for B. anthracis biology and offer new possibilities for microbial forensics and detection.