Embolization of the Pancreas Using Microspheres: A Proof-of-Safety Study in a Porcine Model.

PURPOSE: To evaluate safety and impact of particle embolization on pancreatic function in a pig model. MATERIALS AND METHODS: Embolization of the dorsal pancreatic artery using 100-300-µm particles was performed on 14 Yorkshire pigs. Baseline and post-embolization glucose tolerance testing results and serum amylase/lipase levels were obtained. Pigs were observed for 2 weeks to assess for behavioral signs of pain/distress, bowel changes, and changes to intake/output. After 2 weeks, euthanasia and necropsy with gross and histopathologic assessment of the pancreas were performed. RESULTS: Embolization was technically successful in all pigs. All animals survived the 2-week follow-up without evidence of pain/distress. There were significant increases in amylase and lipase at 24 and 48 hours (P < .001), which normalized by 2 weeks. There was minimal change in glucose tolerance testing at 2 weeks. Bowel habits were unchanged without diarrhea. At necropsy, all examined pancreases had fibrosis in the distal body and tail, without gross evidence of ongoing inflammation. On histopathologic evaluation, all pancreases demonstrated fibrosis in the embolized portions without evidence of active inflammation in treated or adjacent pancreatic tissue. CONCLUSIONS: Particle embolization of the pancreas was feasible and tolerated by all tested pigs with transient amylasemia, lipasemia, and mildly impaired glucose tolerance but without clinical or histopathologic evidence of acute pancreatitis and no evident impact on pancreatic endocrine or exocrine function.

Correlation of Ablation Volume with Renal Function Loss after Cryoablation in Solitary Functioning Kidneys.

PURPOSE: To determine the degree of renal function deterioration after renal cryoablation in patients with a solitary functioning kidney on the basis of ablation volume. MATERIALS AND METHODS: Over a 15-year period, 81 percutaneous cryoablations were performed in solitary functioning kidneys. After exclusion of patients with baseline end-stage renal disease (ESRD) and insufficient follow-up, analysis was performed on 65 procedures in 52 patients (40 men; mean age, 63.5 years). The postcryoablation renal function was based on the lowest serum creatinine within 6 months after procedure. Renal function change was defined as percentage glomerular filtration rate (GFR) change. Volumetric analysis was performed on the target lesion, renal parenchyma, and ablation zone. RESULTS: The median tumor diameter was 2.0 cm (range, 0.8-4.7 cm). The median baseline GFR decreased from 56.4 mL/min/1.73 m2 (range, 17.5-89.7 mL/min/1.73 m2) to 46.9 mL/min/1.73 m2 (range, 16.5-89.7 mL/min/1.73 m2) at median of 95 days (P < .001), equating to a -7.9% median renal function change (range, -45.0% to +30.7%). All patients had Stage 2 or worse chronic kidney disease, and baseline function did not correlate with renal function change. The median volume of ablated parenchyma was 19.7 mL (range, 2.4-87.3 mL), equating to 8.1% (range, 0.7%-37.2%) of total parenchyma. The volume of parenchymal volume ablated correlated significantly with renal function loss, whereas age, hypertension, and diabetes mellitus did not. No patient developed ESRD within 1 year after cryoablation. CONCLUSIONS: Cryoablation in solitary functioning kidneys resulted in a modest reduction in renal function, even in patients with chronic kidney disease and ablations up to 20% of renal parenchymal volume.

Long term impact of transjugular intrahepatic portosystemic shunt (TIPS) creation on hepatic morphology.

PURPOSE: The purpose of this study was to evaluate long-term morphologic changes occurring in the liver after TIPS creation with correlation with hepatic function to gain insight on the physiologic impact of TIPS on the liver. METHODS: This retrospective study included patients who underwent TIPS creation between 2005 and 2022 and had contrasted CT or MRI studies prior to and between 1 and 2 years post procedure. Strict exclusion criteria were applied to avoid confounding. Parenchymal volume and vessel measurements were assessed on the pre- and post-TIPS CT or MRI and MELD scores calculated. RESULTS: Of 580 patients undergoing TIPS creation, 65 patients (mean age, 55 years; 36 males) had pre-TIPS and post-TIPS imaging meeting inclusion criteria at median 16.5 months. After TIPS, the mean MELD score increased (12.9 to 15.4; p = 0.008) and total liver volume decreased (1730 to 1432 mL; p < 0.001). However, the magnitude of volume change did not correlate with MELD change. Neither portosystemic gradient nor TIPS laterality correlated with total or lobar hepatic volume changes or MELD changes. The main portal vein diameter increased (15.0 to 18.7 mm; p < 0.001). Thrombosis of the hepatic vein used for TIPS creation resulted in a mean increase in MELD of +4.1 compared to -2.1 in patients who had a patent and normal hepatic vein (p = 0.007). CONCLUSIONS: Given lack of correlation between portosystemic gradient, hepatic atrophy, hepatic function, and TIPS laterality, the alterations in portal flow dynamics after TIPS may not be impactful to hepatic function. However, hepatic vein patency after TIPS correlated with improved hepatic function.

Comparing magnetic resonance imaging and ultrasound in the clinical evaluation of fibroids prior to uterine artery embolization.

PURPOSE: Uterine artery embolization has become established as a frontline treatment for uterine leiomyomata. In planning embolization, preprocedural imaging can further characterize pathology and anatomy, but it may also reveal coexisting diagnoses that have the potential to change clinical management. The purpose of this study is to compare the diagnostic outcomes of ultrasound and MRI performed for patients prior to undergoing embolization. METHODS: The study cohort consisted of 199 patients who underwent uterine artery embolization at a single academic institution between 2013 and 2018. Prior to embolization, all patients had an MRI confirming a leiomyomata diagnosis. Additionally, 118 patients underwent transvaginal ultrasound within five years prior to MRI. MRI findings were analyzed and, when applicable, compared to prior ultrasound impressions to assess for the incidence of new findings. The diagnoses of interest were adenomyosis, hydrosalpinx, predominantly infarcted leiomyomata, and large intracavitary leiomyomata. Data were collected from retrospective chart review and included demographics, symptomology, and imaging reports. RESULTS: 199 patients ultimately underwent embolization for treatment of MRI-confirmed leiomyomata. Of 118 patients who also had an ultrasound within five years prior to their MRI, 26 (22.0%) received a second gynecologic diagnosis based on MRI findings that was not previously seen on ultrasound. Of 81 patients who only had an MRI before embolization, 19 (23.5%) received a second gynecologic diagnosis not previously documented. The most common coexisting pathology was adenomyosis, presenting in 34 (17.1%) patients with leiomyomata, followed by large intracavitary leiomyomata (8, 4.0%), infarcted leiomyomata (7, 3.5%), and hydrosalpinx (6, 3.0%),. CONCLUSIONS: When considering uterine artery embolization for the treatment of symptomatic leiomyomata, preprocedural MRI is superior to ultrasound in detecting coexisting pathologies, including adenomyosis and hydrosalpinx. It can also better characterize leiomyomata, including identifying lesions as intracavitary or infarcted. These findings have the potential to alter clinical management or contraindicate embolization entirely.