3D margin assessment predicts local tumor progression after ablation of colorectal cancer liver metastases.

OBJECTIVE: To determine the feasibility and prognostic value of 3D measuring of the ablation margins using a dedicated image registration software. METHODS: This retrospective study included 104 colorectal liver metastases in 68 consecutive patients that underwent microwave ablation between 08/2012 and 08/2019. The minimal ablation margin (MM) was measured in 2D using anatomic landmarks on contrast enhanced CT(CECT) 4-8 weeks post-ablation, and in 3D using an image registration software and immediate post-ablation CECT. Local tumor progression (LTP) was assessed by imaging up to 24 months after ablation. A blinded interventional radiologist provided feedback on the possibility of additional ablation after examining the 3D-margin measurements. RESULTS: The 3D-margin assessment was completed in 79/104 (76%) tumors without the need for target manipulation. In 25/104 (24%) tumors, manipulation was required due to image misregistration. LTP was observed in 40/104 (38.5%) tumors: 92.5% vs 7.5% for those with margin <5mm vs ≥5mm, respectively (p = 0.0001). The 2D and 3D-assessments identified margin <5mm in 17/104 (16%), and in 74/104 (71%) ablated tumors, respectively (p < 0.01). The sensitivity and specificity of the 3D software for predicting LTP was 93% (37/40) and 42% (27/64), respectively. Additional ablation to achieve a MM of 5 mm would have been offered in 26/37 cases if the 3D-margin assessment was available intraoperatively. CONCLUSION: Image registration software can measure ablation margins and detect MM under 5 mm intraoperatively, with significantly higher sensitivity than the 2D technique using landmarks on the post-ablation CECT. The identification of a margin under 5 mm is strongly associated with LTP.

Biopsy and Margins Optimize Outcomes after Thermal Ablation of Colorectal Liver Metastases.

BACKGROUND: Thermal ablation is a definitive local treatment for selected colorectal liver metastases (CLM) that can be ablated with adequate margins. A critical limitation has been local tumor progression (LTP). METHODS: This prospective, single-group, phase 2 study enrolled patients with CLM < 5 cm in maximum diameter, at a tertiary cancer center between November 2009 and February 2019. Biopsy of the ablation zone center and margin was performed immediately after ablation. Viable tumor in tissue biopsy and ablation margins < 5 mm were assessed as predictors of 12-month LTP. RESULTS: We enrolled 107 patients with 182 CLMs. Mean tumor size was 2.0 (range, 0.6-4.6) cm. Microwave ablation was used in 51% and radiofrequency ablation in 49% of tumors. The 12- and 24-month cumulative incidence of LTP was 22% (95% confidence interval [CI]: 17, 29) and 29% (95% CI: 23, 36), respectively. LTP at 12 months was 7% (95% CI: 3, 14) for the biopsy tumor-negative ablation zone with margins ≥ 5 mm vs. 63% (95% CI: 35, 85) for the biopsy-positive ablation zone with margins < 5 mm (p < 0.001). CONCLUSIONS: Biopsy-proven complete tumor ablation with margins of at least 5 mm achieves optimal local tumor control for CLM, regardless of the ablation modality used.

Immunofluorescence Assay of Ablated Colorectal Liver Metastases: The Frozen Section of Image-Guided Tumor Ablation?

PURPOSE: To validate an immunofluorescence assay (IFA) detecting residual viable tumor (VT) as intraprocedural thermal ablation (TA) zone assessment and demonstrate its prognostic value for local tumor progression (LTP) after colorectal liver metastasis (CLM) TA. MATERIALS AND METHODS: This prospective study, approved by the institutional review board, included 99 patients with 155 CLMs ablated between November 2009 and January 2019. Tissue samples from the ablation zone (AZ) center and minimal margin underwent immunofluorescent microscopic examination interrogating cellular morphology and mitochondrial viability (IFA) within 30 minutes after ablation. The same tissue samples were subsequently evaluated with standard morphologic and immunohistochemical methods. The sensitivity, specificity, and overall accuracy of IFA versus standard morphologic and immunohistochemical examination were calculated. The LTP-free survival rates were evaluated for the 12-month follow-up period. RESULTS: Of the 311 tissue samples stained, 304 (98%) were deemed evaluable. Of these specimens, 27% (81/304) were considered positive for the presence of VT. The accuracy of IFA was 94% (286/304). The sensitivity and specificity were 100% (63/63) and 93% (223/241), respectively. The 18 false-positive IFA assessments corresponded to samples that included viable cholangiocytes. The 12-month LTP-free survival was 59% versus 78% for IFA positive versus negative for VT AZs, respectively (P < .001). There was no difference in LTP between margin positive only and central AZ-positive tumors (25% vs 31%, P = 1). CONCLUSIONS: The IFA assessment of the AZ can be completed intraprocedurally and serve as a valid real-time biomarker of complete tumor eradication or detect residual VT after TA. This method could improve tumor control by TA.

Imaging and Image-Guided Thermal Ablation for Oligometastatic Colorectal Cancer Liver Disease.

Colorectal cancer affects more than 1 million people worldwide, and half of this population develops liver metastases. Image-guided thermal ablation is an acceptable local therapy for the management of oligometastatic colorectal cancer liver disease, in patients who are noneligible for surgery, or present with recurrence after hepatectomy. Continuous technological evolutions, understanding of tumor variability through disease biology and genetics, and optimization of ablation parameters with ablation margin assessment have allowed patients with resectable small-volume disease to be treated by thermal ablation with curative intent. The growing role of imaging and image guidance in thermal ablation for patient selection, procedure planning, tumor targeting, and assessment of technical success is discussed in this article.

Carotid artery stenting: an update.

PURPOSE OF REVIEW: To present the latest evidence about carotid artery stenting (CAS) including indications, safety, efficacy, and available equipment. RECENT FINDINGS: The micromesh stent, a new stent design which offers excellent flexibility and embolic protection, has been associated with promising outcomes. SUMMARY: CAS has emerged as a minimally invasive treatment method for carotid artery stenosis with comparable outcomes with surgical management. The implementation of new technology combined with operator experience has led to a paradigm shift; however, to date, no robust evidence exists about patient and lesion selection. Many studies are underway to clarify the technical aspects of CAS as well as the optimal treatment of carotid artery stenosis for each patient population.

Current evidence of drug-elution therapy for infrapopliteal arterial disease.

New and sophisticated endovascular devices, such as drug-eluting stents (DES) and drug-coated balloons (DCB), provide targeted drug delivery to affected vessels. The invention of these devices has made it possible to address the reparative cascade of arterial wall injury following balloon angioplasty that results in restenosis. DESs were first used for the treatment of infrapopliteal lesions almost 20 years ago. More recently, however, DCB technology is being investigated to improve outcomes of endovascular below-the-knee arterial procedures, avoiding the need for a metallic scaffold. Today, level IA evidence supports the use of infrapopliteal DES for short to medium length lesions, although robust evidence that justifies the use of DCBs in this anatomical area is missing. This review summarizes and discusses all available data on infrapopliteal drug-elution devices and highlights the most promising future perspectives.

Recanalization of Occluded Transjugular Intrahepatic Portosystemic Shunts Using the Rösch-Uchida Stiffening Cannula.

PURPOSE: To report the safety and efficacy of occluded transjugular intrahepatic portosystemic shunts (TIPS) recanalization using the stiffening cannula (SC) technique. MATERIALS AND METHODS: This is a retrospective, single-centre, single-arm study, investigating the safety and efficacy of transjugular recanalization of occluded TIPS using the SC (Cook, Ind. USA), in cases of failure to cross the occlusion with standard angiographic catheters and balloons. Between October 2015 and October 2017, a total of 15 TIPS revisions have been performed due to shunt occlusion. In all cases in which the initial standard approach to cross the lesion failed, the SC technique was used. The study's primary efficacy outcome measure was technical success, and primary safety outcome measure was immediate procedure-related complications rate. Secondary outcome measures included restenosis and peri-procedural adverse events rates. RESULTS: Among 15 patients with shunt occlusion, seven (7/15; 46.5%) were successfully crossed via transjugular access, using standard angiographic catheters. In the remaining eight patients (nine procedures), recanalization with the SC technique was performed. Technical success was 100%. No complications or peri-procedural adverse events were noted. Restenosis rate was 11.1% (1/9 cases) as only one case of re-occlusion was noted, 3 months following recanalization using sole balloon angioplasty and successfully retreated using the SC technique and stent graft deployment. CONCLUSIONS: The SC technique is a safe and efficient option for the recanalization of occluded TIPS, in cases in which conventional lesion crossing is not feasible, in order to avoid percutaneous transhepatic access or new TIPS creation.