Irreversible Electroporation in Treating Colorectal Liver Metastases in Proximity to Critical Structures.

PURPOSE: To evaluate the safety, efficacy and oncological outcomes of irreversible electroporation (IRE) of unresectable colorectal liver metastases (CRLM) close to critical structures. MATERIALS AND METHODS: This is a single center, IRB approved, retrospective analysis of patients who underwent percutaneous, CT-guided IRE of CRLM. Between August 2018 and October 2023, 26 patients had 46 tumors treated with percutaneous IRE in 30 ablation sessions. Primary endpoints were tumor response and local progression-free survival (LPFS) analyzed using Kaplan-Meier survival curves. Secondary endpoints were overall survival (OS), and distant progression-free survival (DPFS) using Kaplan-Meier survival curves, adverse events rated according to Common Terminology Criteria for Adverse Events, and length of hospital stay. RESULTS: All tumors were close to critical structures, including portal and hepatic veins, inferior vena cava, bile ducts and the gallbladder. All patients received preprocedural systemic therapy (median ten cycles). Median length of hospital stay was one night. Adverse events occurred in seven out of 30 (23%) procedures, with four grade 1 and two grade 2 adverse events, including pleural effusions (n=2), ileus (n=1), small hematoma (n=1) and pneumothorax (n=2) requiring chest tube placements. Following IRE, 1- and 2-year LTPFS was 55.0% and 51.3%. Median DPFS was 3.5 months, with 1- and 2-year DPFS of 23.3% and 9.7%. Six patients died during follow-up (23.1%), with a median OS of 40.4 months. The 1- and 2-year OS were 90.9% and 83.9%. CONCLUSION: IRE is a safe and viable option in the treatment of unresectable CRLM in locations close to critical structures.

Arterial Evaluation.

The vascular lab (VL) is a powerful tool in diagnosing arterial disease, including peripheral and aortic disease, which is cornerstone of many VLs. This article discusses the indications, protocol, and diagnostic criteria of noninvasive testing for peripheral arterial disease and contrast enhanced ultrasound after endovascular repair of aortic aneurysm.

The Vascular Lab and the Interventional Radiologist.

A vascular laboratory (VL) can be defined as a place where physicians and technologists have a commitment to perform and interpret non-invasive testing with objective techniques that are most appropriate to the facility and the skills of the laboratory personnel. It provides the entry point for many patients as well as being the sight for diagnosis and follow up for patients with vascular disease for Interventional Radiologists (IRs). VLs may be run by a multi-specialty service, may be hospital-based, or may be private practice-based providing more of a concierge service. Resident education in the VL is essential and allows IRs to function on equal footing with other medical colleagues who see and treat similar patients from an early stage and throughout an IR's career. In this article we will discuss the IRs imperative connection to the VL.

Abdominal Vascular Evaluation.

The vascular lab (VL) is instrumental in diagnosing vascular diseases such as renal artery stenosis and mesenteric ischemia or following a patient after transjugular intrahepatic portal systemic shunt (TIPS) creation. This article discusses indications, protocol, and diagnostic criteria for abdominal vascular ultrasound. The vascular lab can be used to investigate pathology in the abdomen either as a preliminary screening tool to evaluate for a pathology such as mesenteric artery stenosis in a patient with food fear and weight loss, renal artery stenosis in a patient with refractory hypertension or renal failure, or as a diagnostic tool in follow up after a patient has undergone a transjugular intrahepatic portal systemic shunt (TIPS) for portal hypertension. The technical success of duplex ultrasonography of the abdomen can be compromised by respiratory motion, obesity, and intestinal gas. Therefore, duplex scanning is performed in the fasting state particularly in elective outpatient cases. In emergent cases when pathology such as acute mesenteric ischemia is suspected evaluation with CT angiography may be best.

Intracranial and Extracranial Evaluation.

The vascular lab is an essential tool in diagnosing intracranial and extracranial disease including vasospasm from subarachnoid hemorrhage and carotid artery stenosis in the setting of stroke or transient ischemic attack. This article discusses the indications, protocol, and diagnostic criteria for transcranial doppler (TCD) and carotid artery duplex ultrasound. Intracranial and extracranial arterial testing by way of TCD and carotid imaging carries enormous implications and can provide life or death information. The learning curve for these techniques is steep but can be mastered with repetition and precise technique.