MRI of the Male Pelvic Floor.

The pelvic floor is a complex structure that supports the pelvic organs and provides resting tone and voluntary control of the urethral and anal sphincters. Dysfunction of or injury to the pelvic floor can lead to gastrointestinal, urinary, and sexual dysfunction. The prevalence of pelvic floor disorders is much lower in men than in women, and because of this, the majority of the published literature pertaining to MRI of the pelvic floor is oriented toward evaluation of the female pelvic floor. The male pelvic floor has sex-specific differences in anatomy and pathophysiologic disorders. Despite these differences, static and dynamic MRI features of these disorders, specifically gastrointestinal disorders, are similar in both sexes. MRI and MR defecography can be used to evaluate anorectal disorders related to the pelvic floor. MRI can also be used after prostatectomy to help predict the risk of postsurgical incontinence, to evaluate postsurgical function by using dynamic voiding MR cystourethrography, and subsequently, to assess causes of incontinence treatment failure. Increased tone of the pelvic musculature in men secondary to chronic pain can lead to sexual dysfunction. This article reviews normal male pelvic floor anatomy and how it differs from the female pelvis; MRI techniques for imaging the male pelvis; and urinary, gastrointestinal, and sexual conditions related to abnormalities of pelvic floor structures in men.Online supplemental material is available for this article.©RSNA, 2019.

Ablative Liver Partition and Portal Vein Embolization: Proof-of-Concept Testing in a Rabbit Model.

PURPOSE: To test the hypothesis that a modified approach to portal vein embolization (PVE)-termed ablative liver partition (ALP) and PVE (ALP-PVE)-is feasible and results in greater future liver remnant (FLR) growth compared with PVE alone in a rabbit model. MATERIALS AND METHODS: Eighteen rabbits (median weight, 2.7 kg) underwent PVE (n = 9) or ALP-PVE (n = 9). PVE to cranial liver lobes was performed with 100-300-µm microspheres and metallic coils; the caudal lobe was spared as the FLR. In the ALP-PVE cohort, a liver partition between cranial and caudal lobes was created by using microwave ablation (40 W, 1 min). Animals were euthanized and livers were harvested on postprocedure day 7. Caudal and cranial liver lobes were weighed after 4 weeks of oven drying. Ki-67 immunohistochemistry was used to quantify liver mitotic index. ALP-PVE feasibility was determined based on procedure technical success. Standardized FLR (sFLR; ie, FLR divided by whole liver weight) and mitotic index were compared between PVE and ALP-PVE groups by two-tailed independent-samples Mann-Whitney U test. RESULTS: One PVE-group rabbit died during anesthesia induction and was excluded from technical success calculation. Eight of 8 (100%) and 8 of 9 rabbits (89%) underwent technically successful PVE and ALP-PVE, respectively. There was no difference in sex or weight distribution between groups. sFLR (0.32 vs 0.29; P = .022) and mitotic index (17.5% vs 6.2%; P = .051) were higher in ALP-PVE vs PVE caudal lobes when the first "learning-curve" case from each group was excluded. CONCLUSIONS: ALP-PVE is feasible and may stimulate greater FLR growth compared with PVE in a rabbit model.

Transjugular Intrahepatic Portosystemic Shunt Creation and Variceal Coil or Plug Embolization Ineffectively Attain Gastric Variceal Decompression or Occlusion: Results of a 26-Patient Retrospective Study.

PURPOSE: To assess the efficacy of transjugular intrahepatic portosystemic shunt (TIPS) creation with or without variceal coil and/or plug embolization in decompressing or occluding gastric varices (GVs). MATERIALS AND METHODS: In this retrospective study, 78 patients with GV bleeding who underwent TIPS creation with or without embolotherapy with metallic coils and/or plugs from 1999 to 2014 were identified. Individuals who had a bare-metal TIPS and/or lacked post-TIPS imaging or endoscopic follow-up were excluded. The final cohort included 26 patients (16 men; median age, 54 y; median Model for End-stage Liver Disease score, 16). Variceal types, supplying vessels, and postprocedure GV patency on cross-sectional imaging or endoscopy were assessed. The primary study outcome measure was GV patency rate as a surrogate for efficacy of TIPS creation with or without embolization. RESULTS: GVs included gastroesophageal varix types 1 (n = 10) and 2 (n = 2), isolated GV types 1 (n = 4) and 2 (n = 2), and unspecified (n = 8). TIPS creation resulted in a median final portosystemic pressure gradient of 7 mm Hg. Multiple GV-supplying vessels (left/posterior/short gastric veins) were present in 65% of patients (n = 17). Embolization was performed in 69% (n = 18). Thirteen, four, and nine patients had imaging, endoscopic, or both imaging/endoscopic follow-up. GV patency rate was 65% (n = 17; 61%/75% with/without embolization) at a median of 128.5 days (range, 1-1,295 d) after TIPS creation. Incidence of recurrent bleeding was 27% (n = 7), and the 90-day mortality rate was 15% (n = 4). CONCLUSIONS: In this study, most GVs showed persistent patency despite TIPS decompression and variceal embolization, and the incidence of recurrent bleeding was high. The findings suggest suboptimal efficacy for GVs, and indicate a need for study of alternative or adjunctive approaches to GV treatment, such as chemical obliteration.

What constitutes liver failure after transjugular intrahepatic portosystemic shunt creation? A proposed definition and grading system.

UNLABELLED:  Background and rationale for the study. There is currently no definition of post-transjugular intrahepatic portosystemic shunt (TIPS) liver failure (PTLF), which constitutes a barrier to standardization of TIPS results reporting and limits the ability to compare liver failure incidence across clinical studies. Thisdescriptive study proposes and preliminarily tests the performance of a PTLF definition and grading system. RESULTS: PTLF was defined by ≥ 3-fold bilirubin and/or ≥ 2-fold INR elevation associated with clinical outcomes of prolonged hospitalization/increase in care level (grade 1), TIPS reduction or liver transplantation (grade 2), or death (grade 3) within 30-days of TIPS. PTLF incidence was 20% (grades 1, 2, 3: 10%, 3%, 8%) among 270 TIPS cases, and the scheme identified patients at increased risk for morbidity and mortality with a statistically significant difference in clinical outcomes between PTLF and non-PTLF groups (P<0.0001). CONCLUSIONS: In conclusion, the PTLF definition and classification scheme put forth distributes patients into unique risk groups. PTLF grading may thus be useful for standardization of TIPS results reporting.

Root Cause Analysis of Rebleeding Events following Transjugular Intrahepatic Portosystemic Shunt Creation for Variceal Hemorrhage.

PURPOSE: To identify fundamental causes underlying recurrent variceal hemorrhage (VH) after transjugular intrahepatic portosystemic shunt (TIPS) to ascertain opportunities for improvement of TIPS-based management of VH and prevention of rebleeding. MATERIALS AND METHODS: This single-center retrospective study comprised 166 patients (male-to-female ratio 101:65; median age, 52 y; median Model for End-Stage Liver Disease score, 14) who had TIPS created for VH in 1998-2014. Medical record review was used to identify patients who had recurrent VH events, and root cause analysis allowed identification of the most probable causal factors. A 5-person interventional radiology physician group generated quality improvement (QI) recommendations for process changes to address causal factors, with consensus achieved using a modified Delphi method. RESULTS: Variceal rebleeding occurred after TIPS in 25 (15%) patients. The 1-, 3-, and 5-year variceal rebleeding incidence was 17%, 21%, and 21%, respectively. Variceal rebleeding was associated with high 90-day all-cause mortality incidence (10/25; 40%). Male sex (P = .018) and Model for End-Stage Liver Disease score (P = .009) were statistically associated with variceal rebleeding. The most common primary and secondary causes of recurrent VH were lack of or insufficient variceal embolization (64%). Other causal factors included TIPS stenosis or occlusion (28%) with recurrent portosystemic gradient (PSG) elevation (20%), severe coagulopathy (20%), inadequate portosystemic gradient reduction (12%), and TIPS underdilation (4%). To potentially address variceal rebleeding, 14 preventive QI recommendations were developed. CONCLUSIONS: Although recurrent VH rates after TIPS are not trivial, rebleeding may be related to addressable underlying causal factors. Further investigation may assess the efficacy of QI-based procedure methodologic enhancements in reducing rebleeding incidence after TIPS.

Clearing the Confusion over Hepatic Encephalopathy After TIPS Creation: Incidence, Prognostic Factors, and Clinical Outcomes.

PURPOSE: To assess the incidence, prognostic factors, and clinical outcomes of hepatic encephalopathy (HE) after transjugular intrahepatic portosystemic shunt (TIPS) creation. MATERIALS AND METHODS: In this single-institution retrospective study, 191 patients (m:f = 114:77, median age 54 years, median Model for End-Stage Liver Disease or MELD score 14) who underwent TIPS creation between 1999 and 2013 were studied. Medical record review was used to identify demographic characteristics, liver disease, procedure, and outcome data. Post-TIPS HE within 30 days was defined by new mental status changes and was graded according to the West Haven classification system. The influence of data parameters on HE occurrence and 90-day mortality was assessed using binary logistic regression. RESULTS: TIPS was successfully created with hemodynamic success in 99 % of cases. Median final PSG was 7 mmHg. HE incidence within 30 days was 42 % (81/191; 22 % de novo, 12 % stable, and 8 % worsening). Degrees of HE included grade 1 (46 %), grade 2 (29 %), grade 3 (18 %), and grade 4 (7 %). Medical therapy typically addressed HE, and shunt reduction was necessary in only three cases. MELD score (P = 0.020) and age (P = 0.009) were significantly associated with HE development on multivariate analysis. Occurrence of de novo HE post-TIPS did not associate with 90-day mortality (P = 0.400), in contrast to worsening HE (P < 0.001). CONCLUSIONS: The incidence of post-TIPS HE is non-trivial, but symptoms are typically mild and medically managed. HE rates are higher in older patients and those with worse liver function and should be contemplated when counseling on expected TIPS outcomes and post-procedure course.

MELD score for prediction of survival after emergent TIPS for acute variceal hemorrhage: derivation and validation in a 101-patient cohort.

UNLABELLED: BACKGROUND AND RATIONALE FOR THE STUDY: The Model for End Stage Liver Disease (MELD) score has not been derived and validated for the emergent transjugular intrahepatic portosystemic shunt (TIPS) population. We sought to identify predictive factors for survival among emergent TIPS patients, and to substantiate MELD for outcomes prognostication in this population. RESULTS: 101 patients with acute life threatening variceal hemorrhage underwent emergent TIPS (defined by failed endoscopic therapy for active bleeding, acute hemoglobin drop, ≥ 2-unit transfusion requirement, and/or vasopressor need) at between 1998-2013. Demographic, clinical, laboratory, and procedure parameters were analyzed for correlation with mortality using Cox proportional hazards regression to derive the prognostic value of MELD constituents. Area under receiver operator characteristic (AUROC) curves was used to assess the capability of MELD prediction of mortality. TIPS were created 119 ± 167 h after initial bleeding events. Hemodynamic success was achieved in 90%. Median final portosystemic pressure gradient was 8 mmHg. Variceal rebleeding incidence was 21%. The four original MELD components showed significant correlation with mortality on multivariate Cox regression: baseline bilirubin (regression coefficient 0.366), creatinine (0.621), international normalized ratio (1.111), and liver disease etiology (0.808), validating the MELD system for emergent cases. No other significant predictive parameters were identified. MELD was an excellent predictor of 90-day mortality in the emergent TIPS population (AUROC = 0.842, 95% CI 0.755-0.928). CONCLUSIONS: Based on independent derivation of prognostic constituents and confirmation of predictive accuracy, MELD is a valid and reliable metric for risk stratification and survival projection after emergent TIPS.

Lobar Radioembolization for Intermediate and Advanced Hepatocellular Carcinoma: Retrospective and Prospective Data.

Historically, outcomes reporting for radioembolization with yttrium-90 ( 90 Y) of hepatocellular carcinoma has included patients across the range of Barcelona Clinic Liver Cancer (BCLC) stages. With the potential for curative radiation segmentectomy for BCLC 0/A patients and evolution of systemic therapy for BCLC C patients, focused review by group is of increasing interest. In this review, we report on efficacy of 90 Y in patients with intermediate (BCLC B) and advanced (BCLC C) hepatocellular carcinoma as well as expected toxicities. Additionally, we review existing trials comparing 90 Y to transarterial chemoembolization and systemic treatments in these patient groups and outline future studies.

Radiopaque beads loaded with doxorubicin in the treatment of patients with hepatocellular carcinoma: A retrospective, multi-center study.

BACKGROUND AND AIMS: Radiopaque drug-eluting beads are an emerging treatment option for patients with hepatocellular carcinoma (HCC). The primary objective of this study was to evaluate overall disease and target tumor response of non-resectable HCC after TACE with a doxorubicin-loaded radiopaque microsphere. METHODS: Data were abstracted from records of patients with unresectable HCC who received TACE with doxorubicin-loaded radiopaque LC Bead LUMITM microspheres at one of five United States centers between February 2016 - November 2017. Response was measured using modified response criteria in solid tumors. Primary efficacy endpoints included objective response rate (ORR) and disease control rate (DCR) at first assessment post-treatment, both overall and for targeted tumors. ORR was the sum of complete and partial response. DCR was ORR plus stable disease. Toxicity was calculated using common terminology criteria for adverse events. RESULTS: Eighty-two patients were included. Overall ORR and DCR were 47.6% (39/82) and 76.8% (63/82), respectively. ORR and DCR of target tumors were 56% and 98%, respectively. Five patients experienced adverse events (5/82, 6.1%). No grade 4-5 toxicities occurred. CONCLUSIONS: TACE with drug-loaded radiopaque beads is a promising treatment for unresectable HCC. Prospective studies should evaluate whether radiopaque beads reduce off-target distribution of microspheres.

Does advanced chronic kidney disease impact transjugular intrahepatic portosystemic shunt efficacy and safety?

BACKGROUND AND STUDY AIMS: There are currently limited data available summarizing the clinical outcomes and safety of transjugular intrahepatic portosystemic shunts (TIPS) in cases of advanced chronic kidney disease (CKD). The study aimed to assess efficacy and safety of TIPS in patients with advanced CKD. PATIENTS AND METHODS: Seventeen patients (M :F 8 :9, age 55 years, MELD 24) with grade 4-5 CKD who underwent TIPS for ascites (n = 7) or varices (n = 10) were analyzed. The primary outcome was TIPS efficacy - assessed by comparing paracentesis frequency and diuretic regimen pre- and post-TIPS among ascites patients - and through bleeding cessation in variceal bleeding patients. Other outcomes included hepatic encephalopathy (HE), GFR increase, and mortality. RESULTS:   Median baseline GFR was 19.9 mL/min. No patients were hemodialysis dependent. Median post-TIPS pressure gradient was 8 mm Hg. Among ascites patients, 5/6 (83%) were TIPS responsive, with reduced or stable diuretics in 4/5 (80%). Among variceal hemorrhage cases, bleeding cessation rate was 90% (9/10). New or worsening HE incidence was 47% (8/17), and one patient required shunt reduction. Of 8 patients with lab follow-up, 6 (75%) demonstrated significant GFR increase (42.2 versus 20.0 mL/min, P = 0.028). The 90-day mortality incidence was 29% (5/17). CONCLUSIONS: In conclusion, TIPS can potentially address ascites and variceal bleeding in advanced CKD patients, though HE incidence may be increased. Further investigation in larger cohorts may corroborate these results.

Gastroesophageal Variceal Filling and Drainage Pathways: An Angiographic Description of Afferent and Efferent Venous Anatomic Patterns.

Varices commonly occur in liver cirrhosis patients and are classified as esophageal (EV), gastroesophageal (GEV), or isolated gastric (IGV) varices. These vessels may be supplied and drained by several different afferent and efferent pathways. A working knowledge of variceal anatomy is imperative for Interventional Radiologists performing transjugular intrahepatic portosystemic shunt and embolization/obliteration procedures. This pictorial essay characterizes the angiographic anatomy of varices in terms of type and frequency of venous filling and drainage, showing that different varices have distinct vascular anatomy. EVs typically show left gastric vein filling and "uphill" drainage, and GEVs and IGVs exhibit additional posterior/short gastric vein contribution and "downhill" outflow. An understanding of these variceal filling and drainage pathways can facilitate successful portal decompression and embolization/obliteration procedures.

Yttrium-90 microsphere radioembolization for treatment of lung cancer hepatic metastases.

Because stage 4 lung cancer is associated with dismal 5-year survival rates, new treatment approaches targeting extrapulmonary disease are necessary. Yttrium-90 microsphere radioembolization is an emerging treatment for metastatic hepatic malignancies that results in high tumor response rates and extended patient survival. To date, application of this therapy toward management of lung cancer hepatic metastases has not been extensively described. Herein, we present 2 cases of effective yttrium-90 radioembolization for treatment of lung cancer hepatic metastases, and emphasize the potential coadjuvant value of this procedure in patients with advanced-stage lung cancer and liver-dominant metastatic disease.

Effect of isoflurane on brain tissue oxygen tension and cerebral autoregulation in rabbits.

Oxygen tension (PO(2)) was measured in rabbit whisker barrel cortex using oxygen sensitive electrodes to investigate the impact of isoflurane anesthesia on oxygen autoregulation. Responses to 90s episodes of 100% oxygen inspiration were obtained from rabbits before anesthesia, and then when the animals were anesthetized with 0.5% or 1.5% isoflurane. For each episode, ΔPO(2) (i.e., hyperoxic PO(2) minus baseline PO(2)) was computed. Compared to the conscious state, brain ΔPO(2) increased during anesthesia with 1.5% isoflurane (0.73 MAC) by an average of 116%, whereas 0.5% isoflurane produced an insignificant average increase of 31%. The results suggest that moderate levels of isoflurane impaired autoregulation of brain tissue oxygen tension.