Percutaneous Removal of Migrated Gastrointestinal Stents Using Gastrostomy Access.

This report describes the experience of removing migrated gastrointestinal (GI) stents using a gastrostomy (G) access. Four male patients aged 23-62 years (mean, 42 years) had 6 migrated stents removed using an existing (n = 3) or new (n = 1) G access. Removed stents included 5 covered esophageal stents that migrated into the stomach and 1 distal noncovered duodenal stent that migrated into the proximal duodenum. One patient had 2 stents removed during the same session. All stents were removed successfully without adverse events. Techniques used included the folding technique using a wire in 3 stents and forceps in 2 stents. Eversion technique was used in the duodenal stent. The G or gastrojejunostomy tubes were replaced after stent removal and used for enteral feedings. In conclusion, removing migrated GI stents using an existing or new G access was technically successful and safe.

An Ex Vivo Human Kidney Perfusion Model Confirms Larger Microwave Ablation Dimensions After Transarterial Embolization.

PURPOSE: To utilize a novel ex vivo perfused human renal model and quantify microwave ablation (MWA) size differences in renal tissue when combining MWA with transarterial embolization (TAE). MATERIALS AND METHODS: Human kidneys (n = 5) declined for transplantation were obtained and connected to a fluoroscopic-compatible ex vivo perfusion system. Two ablations-1 standard MWA, 1 TAE-MWA-were performed in each kidney for 2 minutes at 100 Watts using a MWA system (Solero Angiodynamics). MWA alone was performed in the upper pole. In the lower pole, MWA was performed after TAE with M0 LUMI microspheres (Boston Scientific) to achieve angiographic stasis. Ablation zones of coagulative necrosis were sectioned along the long axis and segmented for maximal short axis diameter (SAD) and long axis diameter (LAD) measurements. RESULTS: A total of 10 ablations (5 MWA, 5 TAE-MWA) were performed in five human kidneys. TAE-MWA resulted in significantly increased SAD, LAD, volume, and sphericity compared to standard MWA + SD with mean measurements as follows (5 standard MWA + SD vs 5 TAE-MWA, two-tailed t-test): SAD, 1.8 ± 0.1 cm vs 2.5 ± 0.1 cm (p < 0.001); LAD, 2.9 ± 0.3 cm vs 3.2 ± 0.1 cm (p = 0.039); volume, 5.0 ± 0.5 mL vs 11.0 ± 0.7 mL (p < 0.001); sphericity, 0.4 ± 0.2 vs 0.6 ± 0.1 (p = 0.049). Histology demonstrated no differences in TAE-MWA other than concentrated microspheres. CONCLUSION: This study utilized a novel ex vivo human kidney perfusion model to confirm combined MWA-TAE significantly increases ablation size and spherical shape.

Evaluation of the Catheter Clamp over Hydrophilic Guide Wire Central Venous Catheter Exchange Technique for Air Embolism Prophylaxis in an In Vitro Model.

PURPOSE: To develop a reproducible in vitro model simulating central venous catheter (CVC) exchange with high potential for air embolization and test the hypothesis that a closed catheter clamp over hydrophilic guide wire exchange technique will significantly reduce the volume of air introduced during CVC exchange. MATERIALS AND METHODS: The model consisted of a 16-F valved sheath, 240-mL container, and pressure transducer submerged in water in a 1,200-mL suction canister system. Continuous wall suction was applied to the canister to maintain negative pressure at -7 mm Hg or -11 mm Hg. Each trial consisted of 0.035-inch hydrophilic guide wire introduction, over-the-wire catheter exchange, and wire removal following clinical protocol. A total of 256 trials were performed, 128 trials at each pressure with the catheter clamp open (n = 64) or closed (n = 64) around the hydrophilic guide wire. RESULTS: There was a statistically significant lower volume of air introduced with closed clamp over-the-wire exchanges than with open clamp exchanges at both pressures (2-tailed t-test, P < .001). At -7 mm Hg, a mean of 48.0 mL (SD ± 9.3) of air was introduced with open clamp and 20.6 mL (SD ± 4.7) of air was introduced with closed clamp. At -11 mm Hg, 97.8 mL (SD ± 11.9) of air was introduced with open clamp and 37.8 mL (SD ± 6.3) of air was introduced with closed clamp. CONCLUSIONS: This study demonstrated the use of a reproducible in vitro model mimicking conditions causing air embolism during CVC exchange. Results showed that CVC exchange using closed catheter clamp over hydrophilic guide wire exchange technique significantly reduced the volume of air introduced per exchange.

Biliary Leaks: Multidisciplinary Approach to Diagnosis and Treatment.

Bile leaks arise from various causes such as trauma, complications after hepatobiliary surgery, and intrahepatic malignancies or their associated liver-directed treatments. Bile leaks can result in significant morbidity and mortality. Delayed diagnosis is not uncommon due to nonspecific manifestations; therefore, a high clinical suspicion is needed. A multidisciplinary approach for treatment of biliary leaks with prompt referral to tertiary care centers with experienced hepatobiliary surgeons, advanced endoscopists, and interventional radiologists is needed to address these challenging complications. Management of biliary leaks can range from conservative management to open surgical repair. Minimally invasive procedures play a crucial role in biliary leak treatment, and the interventional radiologist can help guide appropriate management on the basis of a clear understanding of the pathophysiology of biliary leaks and a current knowledge of the armamentarium of treatment options. In most cases, a simple diversion of bile to decompress the biliary system may prove effective. However, persistent and high-output biliary leaks require delineation of the source with tailored treatment options to control the leak. This may be done by additional diversions, occluding the source, reestablishing connections, or using a combination of therapies to bridge to more definitive surgical interventions. The authors describe the different treatment options and emphasize the role of interventional radiology. ©RSNA, 2024.

Creation of an Ex Vivo Renal Perfusion Model to Investigate Microwave Ablation.

This study hypothesized that an ex vivo renal perfusion model can create smaller microwave ablation (MWA) measurements during perfused states compared with nonperfused states across multiple device settings. Nine bovine kidneys, a fluoroscopic compatible perfusion model, and a commercially-available clinical MWA system were used to perform 72 ablations (36 perfused and 36 nonperfused) at 9 different device settings. Comparing perfused and nonperfused ablations at each device setting, significant differences in volume existed for 6 of 9 settings (P < .05). Collapsed across time settings, the ablation volumes by power were the following (perfused and nonperfused, P value): 60 W, 2.3 cm3 ± 1.0 and 7.2 cm3 ± 2.7, P < .001; 100 W, 5.4 cm3 ± 2.1 and 11.5 cm3 ± 5.6, P < .01; and 140 W, 11.2 cm3 ± 3.7 and 18.7 cm3 ± 6.3, P < .01. Applied power correlated with ablation volume: perfused, 0.021 cm3/W and R = 0.462, P = .004, and nonperfused, 0.029 cm3/W and R = 0.565, P < .001. These results support that an ex vivo perfused organ system can evaluate MWA systems and demonstrate heat sink perfusion effects of decreased ablation size.

Experimental Analysis of Passenger Comfort with Variable Preloaded Rear Springs on a Low-Cylinder Motorcycle.

The present study contains an experimental analysis of the vibratory response in a low-cylinder engine motorcycle at varying suspension preloads. Three different speed bumps of varying heights were used to subject the motorcycle to different vibrations. The analysis was carried out in three domains: time, frequency, and time-frequency. A triaxial accelerometer was used to measure the vibrations at the seat of the vehicle. The results indicated that the suspension system became more differentiated as the height of the bumps increased. However, for lower bumps, the action of the three spring preloads studied was quite similar. Quantitatively, only the higher bump showed a significant difference between the set preloads. The spectral distribution revealed that the frequency of interest was below 20 Hz for all the studied cases, which is in the same range of human body natural frequencies. The findings of this research can be utilized to enhance the design of low-cost motorcycles, thereby improving the safety and comfort of their drivers and passengers. This study constitutes a significant step towards developing an affordable system capable of gathering sufficient data to support the creation of evidence-based public health policies and propose new transport industry standards based on field measurements.

Superior vena cava filter placement over existing central venous lines: Is line removal necessary?

OBJECTIVES: To evaluate the technical feasibility and clinical safety of superior vena cava (SVC) filter placement over preexisting central venous lines (CVLs) in 23 patients who had upper extremity deep venous thrombosis with contraindications to anticoagulation. METHODS: A retrospective review of the images and electronic medical records of 23 patients from 2008 to 2018 with SVC filters placed over an existing central venous line was performed in a single tertiary medical center. Twenty-one filters were placed over smaller lines (<8 Fr), and two were placed over hemodialysis catheters. Venograms before and after filter placement were compared to detect any evidence of line displacement or entrapment. Medical records were reviewed to determine whether there was any difficulty during line removal. RESULTS: In two of five patients with dual lines, significant line displacement was noted in the left-sided lines, both lines were later removed without complications. In one patient with a hemodialysis catheter, the filter was deployed over the tip of the catheter resulting in the entrapment of one of the legs of the filter within a side hole of the line. Fourteen patients had their lines later removed 3 days to 3 months after filter placement without reported problems. Nine patients had their CVLs left in place until the patient's death or discharge to a long-term facility. CONCLUSIONS: SVC filter placement over preexisting CVLs seems to be technically feasible and clinically safe in patients with <8-Fr CVLs. However, placement of the filters over hemodialysis catheters can result in leg entrapment.

A single center 10-year clinical experience with superior vena cava retrievable filters.

PURPOSE: To report a 10-year clinical experience with superior vena cava (SVC) retrievable filters. METHODS: A retrospective review of patients with SVC filters was performed between 2008 and 2018 in a single tertiary medical center. Patient demographics, indications for filter placement, type of filter placed, and clinical evolution were recorded. Complications during placement, retrieval, and follow-up were determined. RESULTS: Fifty patients ages 17-89 years (average 54) underwent SVC retrievable filter placement. Main indication for filter placement was deep venous thrombosis of the major upper extremity and/or internal jugular veins with contraindications to anticoagulation. Complications during placement included inadvertent filter placement in the right brachiocephalic vein in two patients, another patient had a leg of the filter entrapped in the tip of a hemodialysis catheter that required filter reposition and line exchange. Thirteen patients had attempted retrieval with 12 filters successfully removed 7-420 days after placement (mean 170). On follow-up images available in 24 patients, 13 filters were noted to be significantly tilted and 10 filters had evidence of leg penetration. No other serious late complications were noted. CONCLUSION: The use of retrievable SVC filters in patients with upper extremity DVT is highly questionable. There is a high incidence of filter malposition, filter tilting, and leg penetration.

Transjugular Portosystemic Shunt Reductions: A Retrospective Single-Center Experience.

PURPOSE: To report the results of transjugular intrahepatic portosystemic shunt (TIPS) reductions for hepatic encephalopathy (HE), acute liver failure (ALF), and pulmonary hypertension (PH). MATERIALS AND METHODS: A single-institution retrospective review analysis was performed between 2007 and 2017 on patients undergoing TIPS reduction at single tertiary liver transplant center. A total of 27 patients (14 males and 13 females) underwent TIPS reduction for refractory HE (n = 18), ALF (n = 7), and PH (n = 2). The average age at time of reduction was 59 years (range, 23-73; standard deviation [SD], 8). Mean prereduction Model of End-State Liver Disease-Na and portosystemic pressure gradient were 19 (range, 11-29; SD, 6) and 9.4 mm Hg (range, -2 to 19; SD, 4.8), respectively. Comparison between responders and nonresponders was performed for multiple variables using a 2-tailed t test. Methods of reduction were compared in cases of HE. RESULTS: Technical success, defined as a decrease of at least 50% of the caliber of the shunt, was 100%. Clinical success rates in improving HE, ALF, and PH were calculated at 89%, 71%, and 100%, respectively. Eight patients had major and 10 had minor complications after the reductions. There were 3 shunt thrombosis. Pre- and postreduction Model of End-State Liver Disease-Na, portosystemic pressure gradient change, duration of indwelling TIPS, and reduction method were not significantly different between responders and nonresponders. Six-month survival rates were 80%, 20%, and 100% for HE, ALF, and PH, respectively. CONCLUSIONS: TIPS reduction is effective in reversing refractory HE, ALF, and PH after TIPS creation. TIPS reduction is associated with a high rate of complications and should be reserved for severe refractory overshunting complications.

Segmental liver ischemia/infarction after elective transjugular intrahepatic portosystemic shunt creation: clinical outcomes in 10 patients.

PURPOSE: To determine the clinical significance and potential mechanisms of segmental liver ischemia and infarction following elective creation of a transjugular intrahepatic portosystemic shunt (TIPS). MATERIALS AND METHODS: A retrospective review of 374 elective TIPS creations between March 2006 and September 2014 was performed, yielding 77 contrast-enhanced scans for review. Patients with imaging evidence of segmental perfusion defects were identified. Model for End-stage Liver Disease scores, liver volume, and percentage of liver ischemia/infarct were calculated. Clinical outcomes after TIPS creation were reviewed. RESULTS: Ten patients showed segmental liver ischemia/infarction on contrast-enhanced imaging after elective TIPS creation. Associated imaging findings included thrombosis of the posterior division (n = 7) and anterior division (n = 3) of the right portal vein (PV). The right hepatic vein was thrombosed in 5 patients, as was the middle hepatic vein in 3 and the left hepatic vein in 1. One patient had acute thrombosis of the shunt and main PV. Three patients developed acute liver failure: 2 died within 30 days and 1 required emergent liver transplantation. One patient died of acute renal failure 20 days after TIPS creation. A large infarct in a transplant recipient resulted in biloma formation. Five patients survived without additional interventions with follow-up times ranging from 3 months to 5 years. CONCLUSIONS: Segmental perfusion defects are not an uncommon imaging finding after elective TIPS creation. Segmental ischemia was associated with thrombosis of major branches of the PVs and often of the hepatic veins. Clinical outcomes varied significantly, from transient problems to acute liver failure with high mortality rates.

An international multicenter comparison of time-SLIP unenhanced MR angiography and contrast-enhanced CT angiography for assessing renal artery stenosis: the renal artery contrast-free trial.

OBJECTIVE: The unenhanced MR angiography (MRA) technique time-spatial labeling inversion pulse (time-SLIP) may provide a safe alternative for evaluating the renal arteries for stenosis. This international multicenter trial tested the hypothesis that time-SLIP unenhanced MRA is accurate and robust for assessing the renal arteries for stenosis in comparison with contrast-enhanced CT angiography (CTA). SUBJECTS AND METHODS: Four centers (United States, Europe, Asia) enrolled 75 patients (average age ± SD, 58 ± 13 years; 41 [55%] men and 34 [45%] women). Each patient underwent abdominal contrast-enhanced CTA and abdominal unenhanced MRA using time-SLIP with balanced steady-state free precession. All images were visually assessed for quality (arterial signal intensity) and for the absence or presence of renal artery stenosis (≤ 50% or > 50% stenosis, respectively). In addition, for arteries with any visible disease, the severity of the stenosis was quantified. Two blinded readers evaluated each study. No arteries were excluded from analysis. RESULTS: Unenhanced MRA image quality was excellent for 56 of 75 patients (75%) and good for 16 of 75 patients (21%). CTA was used as the reference standard and showed that 23 of 161 renal arteries (14.3%) had stenosis > 50%. Unenhanced MRA correctly classified 17 of the 23 renal arteries with > 50% stenosis and correctly classified 128 of the 138 renal arteries as not having disease (≤ 50% stenosis) to yield a sensitivity of 74%, specificity of 93%, and accuracy of 90% (χ(2) = 0.56; p = 0.45, no statistically significant difference). Of the 16 misclassified arteries, only three had a clinically relevant misclassification (CTA ≥ 70% stenosis and unenhanced MRA ≤ 50% stenosis or unenhanced MRA ≥ 70% stenosis and CTA ≤ 50% stenosis). On average, measured stenotic severity (n = 28 arteries) was similar for unenhanced MRA (64% ± 17%) and CTA (62% ± 16%) (p = 0.51). CONCLUSION: Compared with contrast-enhanced CTA, the unenhanced MRA technique time-SLIP shows promise for assessing the renal arteries for stenosis. The unenhanced MRA technique time-SLIP may provide a safe alternative for evaluating the renal arteries for stenosis.

Transjejunal biliary interventions: going back to a road less traveled.

Percutaneous transhepatic biliary interventions are not without risk and potential complications. In patients with bilioenteric anastomosis in whom repeat biliary interventions are expected, percutaneous transjejunal access is a very useful approach that is not frequently used nowadays. We provide a brief review of the history, indications, and current status of transjejunal biliary interventions. Transjejunal biliary access provides a relatively atraumatic pathway to the biliary system in patients that need repeat interventions. Multiple studies have provided convincing data that in appropriately chosen patients receiving a bilioenteric anastomosis, an antecolic limb of jejunum should be placed for subsequent access in biliary intervention.

Superior vena cava (SVC) filters placed over central lines - analysis of line trapping and difficulties with line retrieval: an in-vitro experimental study.

BACKGROUND: Placement of superior vena cava (SVC) filters has been shown to be both safe and effective in preventing symptomatic pulmonary embolism in patients with upper extremity deep venous thrombosis that have contraindications to anticoagulation therapy. In many patients, existing central lines pose a challenge to SVC filter placement due to the theoretical risk of line displacement and/or entrapment. PURPOSE: To assess the risk of catheter entrapment by filter legs during SVC filter deployment and the risk of subsequent filter migration during catheter removal. MATERIAL AND METHODS: A model was created by placing a 22 mm vascular graft inside a plastic tube and submerged in a warm saline bath. Five types of filters were deployed under fluoroscopic guidance over different types of central lines of varying calibers (5-14 Fr). Each filter was deployed five times over each type of central line. The positioning of the legs of the filters in relationship to the central lines was studied by fluoroscopic and direct inspection. The lines were then removed under fluoroscopic guidance noting any line trapping, migration, and/or tilting of the filters. RESULTS: Movement of the lines during filter expansion was commonly seen after deployment of all filters with varying frequencies. During line removal slight resistance was encountered with the Celect filter (10%) and the Option filter (5%), while significant resistance was only encountered when using the OptEase filter (20%). Filter migration was only observed when the OptEase filter was deployed over large (>10 Fr) caliber lines (10%). CONCLUSION: When SVC filters are placed over existing central lines, the risk of catheter entrapment is very low in this in-vitro model. Filter migration during line retrieval was only observed when the OptEase filter was placed over >10 Fr caliber lines.

Integrative multi-omics characterization of hepatocellular carcinoma in Hispanic patients.

Background: The incidence and mortality rates of hepatocellular carcinoma (HCC) among Hispanics in the United States are much higher than those of non-Hispanic whites. We conducted comprehensive multi-omics analyses to understand molecular alterations in HCC among Hispanic patients. Methods: Paired tumor and adjacent non-tumor samples were collected from 31 Hispanic HCC in South Texas (STX-Hispanic) for genomic, transcriptomic, proteomic, and metabolomic profiling. Additionally, serum lipids were profiled in 40 Hispanic and non-Hispanic patients with or without clinically diagnosed HCC. Results: Exome sequencing revealed high mutation frequencies of AXIN2 and CTNNB1 in STX Hispanic HCCs, suggesting a predominant activation of the Wnt/ß-catenin pathway. The TERT promoter mutation frequency was also remarkably high in the Hispanic cohort. Cell cycles and liver functions were identified as positively- and negatively-enriched, respectively, with gene set enrichment analysis. Gene sets representing specific liver metabolic pathways were associated with dysregulation of corresponding metabolites. Negative enrichment of liver adipogenesis and lipid metabolism corroborated with a significant reduction in most lipids in the serum samples of HCC patients. Two HCC subtypes from our Hispanic cohort were identified and validated with the TCGA liver cancer cohort. The subtype with better overall survival showed higher activity of immune and angiogenesis signatures, and lower activity of liver function-related gene signatures. It also had higher levels of immune checkpoint and immune exhaustion markers. Conclusions: Our study revealed some specific molecular features of Hispanic HCC and potential biomarkers for therapeutic management of HCC and provides a unique resource for studying Hispanic HCC.

A Comprehensive Review of Transjugular Intrahepatic Portosystemic Shunt-Related Complications.

Transjugular intrahepatic portosystemic shunt (TIPS) is one of the most technically complex procedures in interventional radiology, the need to connect two veins with variable anatomy, located in two different planes in hard and many times small cirrhotic livers using a needle, can be quite challenging. Despite more than 30 years of performing TIPS, the complex hemodynamics of the portal system are not fully understood, and sometimes unpredictable alterations of the portal flow can lead to serious unexpected complications. The best strategies to prevent TIPS complications are optimal patient selection, meticulous technique, operator experience, and immediate correction of identified adverse events. The purpose of this article is to review the technical complications with TIPS, the unique complications related to the use of stent grafts, and the late complications after the procedure, with emphasis on ways to prevent and treat them.

Transjugular Intrahepatic Portosystemic Shunt Reductions.

Transjugular intrahepatic portosystemic shunts (TIPS) are effective in reducing the portosystemic gradient and relieving complications of portal hypertension. Despite optimal patient selection, TIPS placement can be limited due to worsening hepatic encephalopathy and liver failure. In these cases, TIPS reduction may be necessary. A brief history of TIPS reduction and techniques for reduction are reviewed.

Abscess drain migration into the colon following laparoscopic cholecystectomy.

Percutaneous abscess drainage is a procedure commonly performed by interventional radiologists to provide source control on infections using CT or ultrasound guidance. The interventionalist has many different sizes and shapes of catheters to treat abscesses of varying sizes and locations, but the general approach to each abscess is similar: provide a percutaneous route for purulence, bacteria, necrotic tissue, and other debris to escape the body. While generally considered a low-risk procedure, adverse events can occur due to operator error or other means. We present a unique case of an abscess drain placed into a right upper quadrant abscess that formed following laparoscopic cholecystectomy that perforated and entered the colon. Astute physicians, both in the emergency department and the radiology reading room, were able to rapidly rule out more common post-operative complications and make the correct diagnosis, likely preventing dangerous sequelae from developing in this patient.