Safety and Effectiveness of Transhepatic Access for Percutaneous Renal Mass Cryoablation: A Multicenter Cohort.

PURPOSE: To establish transhepatic percutaneous cryoablation of renal masses as a safe and effective approach. MATERIALS AND METHODS: A retrospective review of records from 3 separate medical centers was performed identifying 23 patients (median age, 63 years [range 41-84 years]; 12 female [52.2%]) who underwent percutaneous transhepatic cryoablation for right-sided renal masses (median diameter, 2.4 cm [1.5-4.6 cm]) between 2008 and 2021. The median radius, exophytic/endophytic, nearness to collecting system or sinus, anterior/posterior, and location relative to polar lines (RENAL) nephrometry score was 5 (4-10). Adverse events (AEs) were classified according to the Society of Interventional Radiology (SIR) and Clavien-Dindo (CD) classifications. Primary and secondary technical success of each procedure were recorded. RESULTS: Renal cell carcinoma (of any subtype) was found in 10 (71.5%) of the 14 masses that were biopsied. Tract cautery was used for transhepatic probes in 14 (63.6%) of 22 procedures. Three (13%) of 23 patients had postprocedural AEs. Two cases (8.6%) were hemorrhages related to transhepatic access (SIR moderate-2, CD 2; SIR severe-3, CD 1), and 1 case (4.4%) was related to bowel injury (SIR severe-3, CD 3a). There were no instances of pneumothorax. Tract cautery was used in the procedures that resulted in an AE. Primary technical success was achieved in 84.2% (16/19) of procedures, whereas secondary technical success was achieved in 2 additional patients. The secondary technical success rate was 94.7% (18/19). Four patients did not have imaging follow-up. CONCLUSIONS: The transhepatic approach to cryoablation of renal masses appears to have an acceptable safety profile and technical success rate. Larger studies, preferably comparative to nontranshepatic approach, are recommended.

External Validation of the Percutaneous Renal Ablation Complexity Scoring System in Patients Undergoing Percutaneous Cryoablation or Microwave Ablation of Renal Tumors.

PURPOSE: To assess the ability of the Percutaneous Renal Ablation Complexity (P-RAC) scoring system to predict procedural complexity or adverse events (AEs) in adult patients undergoing percutaneous thermal ablation of renal tumors. MATERIALS AND METHODS: A retrospective review of 240 consecutive adult patients who underwent percutaneous thermal renal ablation from 2004 to 2018 was conducted. The P-RAC score was calculated for each renal tumor and procedural complexity recorded. A correlation coefficient was calculated for the P-RAC score and both the number of probes used and procedural duration. Receiver operating characteristic curves assessed the score's ability to predict the use of adjunctive techniques and/or major AEs, classified according to the Society of Interventional Radiology guidelines. RESULTS: For the entire cohort, there was a weak correlation between P-RAC scores and both the number of probes used (r = 0.31; P < .001) and procedural duration (r = 0.18; P = .03). When evaluating only patients treated with microwave ablation (MWA), no correlation between P-RAC scores and either the number of probes (P = .7) used or procedural duration (P = .4) was found. The area under the curve (AUC) for the P-RAC score to predict the use of adjunctive techniques was 0.55 and 0.53 for the entire cohort and MWA group, respectively. The AUC for the P-RAC score to predict major AEs was 0.70, 0.71, and 0.73 for the entire cohort, MWA group, and cryoablation group, respectively. CONCLUSIONS: The P-RAC scoring system is limited in its ability to predict percutaneous thermal renal tumor ablation procedural complexity, especially in patients treated with MWA. The scoring system may have a role in identifying patients at risk of major AEs.

Portal Interventions in the Setting of Venous Thrombosis or Occlusion.

Portal vein thrombosis most commonly occurs as a complication of liver cirrhosis and can result in worsening symptoms of portal hypertension, which often can be challenging to treat with conventional decompression therapies. In addition, because complete portal vein thrombosis is associated with higher posttransplant morbidity and mortality, it is regarded as a relative contraindication to liver transplant. Often, the diagnosis of portal vein thrombosis is incidental; hence, imaging remains the mainstay for diagnosing this complication and is used to guide subsequent treatment. Although anticoagulation is the initial approach used to treat acute portal vein thrombosis, endovascular and/or surgical interventions may be necessary when there is concern for impending bowel ischemia. Treatment of chronic portal vein thrombosis is primarily aimed at alleviating the symptoms of portal hypertension and improving the chance of candidacy for liver transplant. Awareness of the portal venous anatomy to differentiate it from the periportal collaterals is key during recanalization of a chronically occluded portal vein. The authors provide an overview of the pathophysiology, acute and chronic imaging findings, and management of portal vein thrombosis, with a specific focus on endovascular management, as well as a summary of the current related literature. An invited commentary by Lopera and Yamaguchi is available online. ©RSNA, 2022.

Survival Outcomes of Very Small Drug-Eluting Beads Used in Chemoembolization of Unresectable Hepatocellular Carcinoma.

PURPOSE: To assess the safety and efficacy of transarterial chemoembolization using a 75-µm drug-eluting embolic (DEE) in patients with unresectable hepatocellular carcinoma (HCC). MATERIALS AND METHODS: The medical records of 109 patients with a mean age of 64.1 years (range 85-49) treated for unresectable HCC between November 2013 and August 2016 with transarterial chemoembolization using a 75-µm DEE were retrospectively reviewed. Patients who had prior therapy for HCC were excluded. Child-Pugh A patients and Barcelona Clinic Liver Cancer stages A/B patients constituted 68.8% and 65.1% of the patients, respectively. The mean size of the index tumors was 5.8 cm (range 18.5-1.2) with 42 (39%) patients with central tumors around the porta-hepatis region. Portal vein invasion was seen in 10 (9.2%) patients. Tumor response was categorized according to the modified Response Evaluation Criteria in Solid Tumors 1.1, and the toxicity profile was assessed using Common Terminology Criteria for Adverse Events, version 4.03. RESULTS: At 1-month follow-up, complete response, objective response, and disease control was seen in 23%, 66%, and 90%, respectively. The median progression-free survival was 11.2 months. The median overall survival was 25.1 months (33.4 months for Child-Pugh A and 28.2 months for Barcelona Clinic Liver Cancer stages A/B), and transplant-free survival was 21.3 months. The 6-, 12-, and 24-month survivals were 91.7%, 75.5%, and 50.5%, respectively. Grade 3 toxicity was seen in 1.8% of the patients; no grade 4 or 5 toxicity was reported. CONCLUSIONS: Transarterial chemoembolization using 75-µm DEE is safe and efficacious in the treatment of HCC.

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.

Transhepatic inferior vena cava recanalization in a case of Budd Chiari syndrome: A novel approach.

Sharp recanalization for short-segment intravascular occlusion, using an endovascular route, has been described for inferior vena cava (IVC) occlusion. Often, the technical challenge to the endovascular management of Budd-Chiari syndrome (BCS) is the recanalization of the occluded hepatic vein or suprahepatic IVC. Presented here, the challenge was the level of occlusion of the suprahepatic IVC, with the resultant separation of both the patent IVC segments in a horizontal plane, making it technically challenging for sharp recanalization. We describe the use of percutaneous transhepatic access into the suprahepatic IVC via the middle hepatic vein under ultrasound guidance with eventual sharp recanalization of the occluded segment of the IVC, in a woman with BCS. This novel approach has not been described in the literature and can serve as an important addition to guide complex suprahepatic IVC recanalization.

Hemodialysis Catheters: Update on Types, Outcomes, Designs and Complications.

Hemodialysis catheters (HDCs) are an essential part of kidney replacement therapy. While these catheters are considered only the bridge to long-term vascular access such as arteriovenous fistulas and grafts, they are associated with significant morbidity and mortality and subsequent increased health care expenditures. However, despite these risks, a large proportion of end stage kidney disease population initiates dialysis using these catheters. The pathogenicity of HDCs stems from its invasive nature to the venous vasculature tree resulting in both mechanical and infectious complications. Therefore, the wide use these catheters in dialysis population and the associated complications necessitated continuous innovations in the catheter material, design, and placement techniques. This review provides an update on the catheter types, catheter tip designs, and the new technologies and innovations aimed to improve the catheter functionality and mitigate its related complications.

Radiological correlation of mechanism of intravascular migration of the ventriculoperitoneal shunt and technical considerations for endovascular retrieval.

Migration of ventriculoperitoneal shunt into the pulmonary artery is a rare complication that can lead to shunt malfunction and cardiopulmonary complications. This case illustrates the significance of accidental transvenous placement of the shunt. Identification of the transvenous course of the catheter on cross sectional imaging can predict future catheter migration and also aid at surgical extraction. Formation of knot within the distal portion of the shunt catheter during migration or endovascular retrieval can occur, therefore measures to retrieve with knot and adhesions should be factored in before.

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.

External Validation of the Renal Ablation-Specific (MC)2 Risk Scoring System in Predicting Complications from Percutaneous Renal Cryoablation.

PURPOSE: The (MC)2 score is a renal ablation-specific risk scoring system to predict major complications from percutaneous renal cryoablation (PRCA). However, it is untested in an external population of patients. The purpose of this study is to validate the ability of the (MC)2 score to predict major complications after PRCA in an external population. MATERIALS AND METHODS: Retrospective review of patients who underwent PRCA from 2004 to 2019. Patient demographics, medical histories, and tumor characteristics were collected. The (MC)2 score was calculated and patients were assigned to low risk (< 5), moderate risk (5-8) and high-risk (> 8) groups. Complications were recorded. Major complications were classified according to CIRSE guidelines. RESULTS: Two hundred and one patients [M = 116; F = 85; median age = 65 (range 27-90)] met inclusion criteria. Eleven patients (5.5%) developed major complications and 50 patients (24.9%) developed minor complications. Of patients with major complications, mean tumor diameter was 39 mm (± 10.4), seven patients (63.6%) had a central tumor, four patients (36.4%) had complicated diabetes, and one patient (9.1%) had a prior MI. Major complication rates were 2.1%, 14%, and 14.3% in the (MC)2 low risk, moderate risk, and high risk groups, respectively. The mean (MC)2 score for patients with major complications [6.2 (± 2.4)] was higher than the mean score for patients with minor complications [4.7 (± 2.4) (p = 0.07)] and no complications [3.9 (± 1.9) (p < 0.01)]. The area under the ROC curve to predict major complications was 0.78. CONCLUSION: The (MC)2 risk scoring system appropriately identifies patients at risk for major complications from PRCA in this external patient population.

Percutaneous Cryoablation of Stage T1b Renal Cell Carcinoma: Safety, Technical Results, and Clinical Outcomes.

PURPOSE: The use of percutaneous cryoablation for T1b (4.1-7.0 cm) renal cell carcinoma, has not yet been widely adopted. The purpose of this study was to describe our experience in the cryoablation of stage T1b tumors with an emphasis on safety, technical results, and clinical outcomes. MATERIALS AND METHODS: A retrospective review of hospital records identified 37 patients who underwent cryoablation for T1b lesions from 2008 to 2018. Patient demographics, comorbidities, tumor characteristics, technical parameters, and outcomes were recorded and analyzed. Recurrence-free, overall, and cancer-specific survival rates were estimated using the Kaplan-Meier method. RESULTS: Thirty-seven patients (22 males, 15 females; mean age 66.5 ± 11.3) with 37 T1b tumors (mean diameter 47.3 ± 6.3 mm) were included. A median of 3 probes were used (range: 1-7). Angio-embolization was used in 3/37 (8.1%) and 2/37 patients (5.4%) required hydrodissection. The mean number of total cryoablation procedures for each patient was 1.5 (median 1; range: 1-4). Technical success was achieved in 88.2% of patients. Recurrence-free survival was 96.5%, 86.1%, and 62.6% at 1, 2, and 3 years respectively. Cancer-specific survival was 100% at 1, 2, and 3 years respectively. Overall survival was 96.7%, 91.8%, and 77.6% at 1, 2, and 3 years respectively. Complications classified as CIRSE grade 2 or higher occurred in 6/37 (16.2%) patients. CONCLUSION: T1b cryoablation is associated with high rates of technical success, excellent cancer-specific survival, and an acceptable safety profile. LEVEL OF EVIDENCE: Level 4, Case Series.