Novel use of the AngioVac system

Abstract

The Vortex Medical AngioVac Cannula was employed in a 71-year-old man with a renal neoplasm with occlusion of the inferior vena cava and involvement of the right atrial cavity. Due to the presence of diffuse metastases, surgery was not indicated, and the AngioVac system was employed to remove the free-floating mobile atrial mass, thus minimizing the risk of pulmonary embolism and as a bioptic tool to allow a correct histological diagnosis. This novel use of this system may be advantageous in other similar cases.

Introduction

The Vortex Medical AngioVac Cannula (VMAC) (AngioDynamics, Latham, NY, USA) is used mainly for removal of soft thrombi from the inferior vena cava (IVC) or right atrium (RA) [1]. We have observed a patient with IVC obstruction protruding into the RA. An angio-computed tomography (CT) raised the suspicion of a renal neoplasm but, due to diffuse metastases, surgical treatment was excluded. Therefore, we have used the VMAC as bioptic tool to provide material for histological diagnosis and to remove the free-floating part of the mass from the RA. This novel use of the VMAC system may be advantageous in other similar cases.

Case report

A 71-year-old male presented with dyspnoea and fever during the last 2 months. On admission, he complained of recent loss of weight and dysuria and was initially treated with antibiotics suspecting a lower urinary tract infection. Worsening of symptoms and appearance of signs of peripheral venous congestion raised the suspicion of a deep venous thrombosis. An angio-CT showed occlusion of the IVC, partially involving both renal veins and extending into the RA, with hepatic and lung involvement. Moreover, signs of pulmonary embolism were already present and, in both kidneys, multiple cysts were present, with an heterogeneous lesion in the right kidney. (Fig. 1a, b). A 2D echo confirmed that the IVC thrombosis was protruding into the RA, consisting in a solid mass to which a second mobile and free-floating one was attached (Fig. 1c). The patient was treated with intravenous administration of heparin with strict echocardiographic monitoring of the RA mass. Since surgery was excluded in this setting, due to the risk of acute pulmonary embolism and in order to better clarify the nature of the RA mass, the use of VMAC was decided, after obtaining patient consent. Under general anaesthesia, tracheal intubation and complete heparinization, a 26F Gore Dryseal introducer (WL Gore & Associates Inc., Flagstaff, AZ) was inserted percutaneously into the right internal jugular vein, through which a VMAC was introduced. Due to complete IVC occlusion, access for the inflow line was obtained with a 22F OptiSite arterial perfusion cannula (Edwards Lifesciences, Irvine, CA) positioned percutaneously into the left internal jugular vein. Connecting the outflow and inflow lines, an extracorporeal bypass circuit was created provided with a filter and a Maquet Rotaflow centrifugal pump (Maquet Cardiopulmonary AG, Hirrlingen, Germany). Under fluoroscopic and transoesophageal echo guidance the tip of the VMAC was advanced into the RA to reach the mobile mass, which was completely removed with repeated suctions (Fig. 1d) yielding abundant whitish material collected into the filter (Fig. 2). During the procedure, which lasted 32 min, flows of 2–3 l were maintained; at the end both cannulae were removed and haemostasis achieved by hand compression.

Fig. 1.

a, b Computed tomography showing the right atrial mass and occlusion of the inferior vena cava (black asterisks). c 2D echo showing the solid mass with a free-floating part into the right ventricle and d suction of the latter by the AngioVac (white asterisks)

Fig. 2.

Material removed from the right atrium into the circuit filter

Histology of the removed material showed features consistent with a renal cell carcinoma. Since surgical treatment was excluded, due to the diffusion of the disease, the patient was referred for oncologic evaluation, for tumour staging and possible palliative treatment. Unfortunately, the patient died 7 days later for multiorgan failure.

Discussion

The VMAC is a system, recently introduced into clinical practice, consisting of a special cannula with a balloon-actuated, expandable funnel-shaped distal tip. Such characteristics enhance venous drainage flow when the balloon is inflated, preventing clogging of the cannula and allowing removal of fresh and soft thrombotic intra-cavitary material mainly from the RA or IVC [1, 2]. This device has been employed more rarely with other indications, such as removal of infective vegetations from endocavitary leads or thrombi from the pulmonary arteries [3, 4]. Recently, Brown et al. reported the use of the VMAC in a patient with renal cell carcinoma and IVC obstruction to prevent pulmonary embolism, combined with surgical excision of the neoplasm [5]. Potential complications of the technique have been reported. Among these, the occurrence of mechanical damage to the tricuspid valve chordae so that special attention is required when the cannula is advanced across the tricuspid valve [3, 4]. Others have reported difficulty in manipulation of the cannula, inability to obtain adequate flow rates, or large neck haematomas due to internal jugular vein lesions [1].

In our case, the initial diagnosis at presentation was uncertain; the presence of a renal neoplasm was suspected, but the histological type was unknown. Unfortunately, based on the findings of other potential tumour localizations, the patient was considered inoperable. However, to establish feasibility of a proper chemotherapic treatment, histological typing was needed. Therefore, we decided to employ the VMAC not only to prevent the risk of further pulmonary embolism, due to the fragility of the RA mass, but also to clarify the diagnosis using therefore this device as a bioptic tool. Since this was our initial experience with VMAC, we used both fluoroscopy and transesophageal echo guidance; however, we believe the latter may be sufficient for adequate positioning of the suction cannula and visualization of the intra-cardiac structures throughout the procedure. We believe that this previously unreported use of the VMAC might be useful in other similar cases in the presence of a right intra-atrial mass of uncertain origin, even if it might be unsuitable for surgical excision.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflicts of interest.

Human and animal rights and informed consent

There was no research involving animals. Patient informed consent was obtained.