Abstract No. 76 ▪ FEATURED ABSTRACT Intravascular ultrasound-guided transvenous biopsy of retroperitoneal targets inaccessible by percutaneous iopsy: technique and initial clinical experience

Abstract

Retroperitoneal lymph nodes and masses adjacent to the inferior vena cava (IVC) or iliac veins can be inaccessible by a conventional percutaneous needle biopsy (PNB) approach due to surrounding vascular and osseous structures. The purpose of this study was to report initial clinical experience with the use of intravascular ultrasound-guided transvenous biopsy (IVUS-TVB) of difficult to access extravascular lymph nodes and masses. From October 2018 to August 2020, 41 IVUS-TVB procedures were performed under fluoroscopy in 38 patients (n = 19 males, mean age = 63) using side viewing intracardiac echocardiography IVUS catheters (ViewFlex Xtra, St. Jude Medical) and 18-gauge transjugular liver biopsy kits (Argon) through separate 10 French sheaths. All cases were initially reviewed for feasibility by PNB but were deemed unacceptably high risk. Patient demographics, target locations and sizes, success rates, and 30-day complications were recorded. Forty biopsies were performed, and 1 lesion was determined to be a vascular malformation by IVUS. Lymph nodes were interaortocaval (n = 11), porta hepatis (n = 5), right paracaval (n = 3), retrocaval (n = 3), iliac chain (n = 3), and retrocrural (n = 2), and masses were in liver (caudate n = 2, dome n = 2, segment 6 n = 2), right adrenal (n = 3), pancreas (n = 2), aortic wall (n = 1) and IVC (n = 1). The average short axis size was 2.6 cm (range 1.0-6.8). IVUS access was jugular (n = 27) or femoral (n = 13), and biopsy access was jugular (n = 28), femoral (n = 11), or portal (n = 1) with passes made from the IVC (n = 37), iliac (n = 2), or portal vein (n = 1). In 32 procedures (80%) IVUS visualization was good. Final pathology was diagnostic of malignancy in 29 procedures (73%), correctly excluded malignancy in 4 (10%), and was non-diagnostic in 7 (18%) with subsequent diagnosis made via repeat IVUS-TVB (n = 3) or surgical biopsy (n = 2) or remaining unknown (n = 2). There were 3 minor complications requiring no treatment (hyperbilirubinemia attributed to hemobilia; contrast induced acute kidney injury; small non-occlusive IVC thrombus at the biopsy site). There was 1 major complication directly related to the biopsy (bleeding at the femoral vein access site requiring transfusion) and 1 other major complication (aortic pseudoaneurysm in a patient with preexisting salmonella aortitis). IVUS-TVB achieves high diagnostic yields similar to accepted thresholds for PNB. Complications rates may be higher but should be weighed relative to the risks of difficult PNB, surgical biopsy, or clinical management without biopsy.