Ablative margin quantification using deformable versus rigid image registration in colorectal liver metastasis thermal ablation: a retrospective single-center study.

PURPOSE: To investigate the correlation of minimal ablative margin (MAM) quantification using biomechanical deformable (DIR) versus intensity-based rigid image registration (RIR) with local outcomes following colorectal liver metastasis (CLM) thermal ablation. METHODS: This retrospective single-institution study included consecutive patients undergoing thermal ablation between May 2016 and October 2021. Patients who did not have intraprocedural pre- and post-ablation contrast-enhanced CT images for MAM quantification or follow-up period less than 1 year without residual tumor or local tumor progression (LTP) were excluded. DIR and RIR methods were used to quantify the MAM. The registration accuracy was compared using Dice similarity coefficient (DSC). Area under the receiver operating characteristic curve (AUC) was used to test MAM in predicting local tumor outcomes. RESULTS: A total of 72 patients (mean age 57; 44 men) with 139 tumors (mean diameter 1.5 cm ± 0.8 (SD)) were included. During a median follow-up of 29.4 months, there was one residual unablated tumor and the LTP rate was 17% (24/138). The ranges of DSC were 0.96-0.98 and 0.67-0.98 for DIR and RIR, respectively (p < 0.001). When using DIR, 27 (19%) tumors were partially or totally registered outside the liver, compared to 46 (33%) with RIR. Using DIR versus RIR, the corresponding median MAM was 4.7 mm versus 4.0 mm, respectively (p = 0.5). The AUC in predicting residual tumor and 1-year LTP for DIR versus RIR was 0.89 versus 0.72, respectively (p < 0.001). CONCLUSION: Ablative margin quantified on intra-procedural CT imaging using DIR method outperformed RIR for predicting local outcomes of CLM thermal ablation. CLINICAL RELEVANCE STATEMENT: The study supports the role of biomechanical deformable image registration as the preferred image registration method over rigid image registration for quantifying minimal ablative margins using intraprocedural contrast-enhanced CT images. KEY POINTS: • Accurate and reproducible image registration is a prerequisite for clinical application of image-based ablation confirmation methods. • When compared to intensity-based rigid image registration, biomechanical deformable image registration for minimal ablative margin quantification was more accurate for liver registration using intraprocedural contrast-enhanced CT images. • Biomechanical deformable image registration outperformed intensity-based rigid image registration for predicting local tumor outcomes following colorectal liver metastasis thermal ablation.

Understanding the Basics of Commonly Used Wires in Interventional Radiology.

A wide variety of wires are available for use in interventional radiology, with wires demonstrating differences in construction, diameter, length, coating, shape, and taper. It is crucial to understand the difference in characteristics between these wires to select the most effective and safe wire for the intended purpose when undertaking a procedure. This article reviews the qualities and functions of different types of wires to aid in this decision-making process.

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.

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.

Role of Interventional Radiologist in the Management of Acute Pulmonary Embolism.

Pulmonary embolism is a common cause of morbidity and mortality which continues to increase in overall incidence. Because it can occur with a wide range of clinical presentations, different guidelines have been developed for appropriate risk stratification of patients; interventional radiology plays a vital role in the management of both massive and submassive pulmonary embolism. Catheter-directed therapy, including mechanical and aspiration thrombectomy, standard catheter-directed thrombolysis, and ultrasound-accelerated thrombolysis, has many benefits, including lower thrombolytic doses and intraclot administration of thrombolytic therapy. While the role of catheter-directed therapy is still being developed, four important prospective studies have demonstrated its safety and efficacy. Additional studies comparing short- and long-term clinical outcomes in patients treated with catheter-directed therapy versus anticoagulation are the next step in understanding its role within the management of submassive pulmonary embolism. Furthermore, multidisciplinary pulmonary embolism response teams, in which interventional radiology plays a crucial role, are becoming essential to appropriately managing pulmonary embolism patients, including selection of those who may benefit from catheter-directed therapy.

Erratum: Role of Interventional Radiologist in the Management of Acute Pulmonary Embolism.

[This corrects the article DOI: 10.1055/s-0039-3401841.].

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.