NSS is a well-established treatment tool for patients with renal masses and it is growing up as treatment of choice for patients with small lesions and poor functional residual parenchyma.
Active bleeding (AB),
pseudoaneurysms (PA),
arteriovenous fistulas (AVF),
and arterio-caliceal fistulas (ACF) have been described as rare but potentially life-threatening RVI associated to NSS.
In this scenario,
rapid clinical evaluation and diagnosis of the underlying RVI are essential to obtain a good treatment outcome,
avoiding fatal events in this subgroup of patients.
Ultrasonography (US) and Computed Tomography (CT) are the imaging tools commonly used to achieve the correct diagnosis and are generally sufficient to provide a proper lesion characterization (site,
extension,
vascular involvement) and,
in association with the clinical evaluation,
an adequate treatment planning (surgical vs endovascular; material choice).
US is generally the first imaging screening tool,
in patients with suspected RVI,
because of its clear advantages such as rapidity,
availability,
absence of radiation exposure,
possibility to be performed at bedside,
while the patient is being evaluated and managed in an emergency room and absent contrast medium administration.
It has a high sensitivity for detecting intra-abdominal fluid but is relatively insensitive for parenchymal injuries and retroperitoneal haemorrhage.
CT angiography is often necessary to confirm the diagnostic suspect.
CT easily detects signs of active bleeding in the peri-renal space or in the urinary tract,
suggesting if bleeding has an arterial or venous origin,
defines peri-renal hematoma and the possible discontinuity of Gerota’s fascia and clearly identifies other RVI such as PA and AVF.
Surgery (nephrectomy) remains the treatment of choice in patients presenting with unstable hemodynamic conditions.
RAE refers to the intentional occlusion of the renal artery,
or its branches,
by the delivery of one or more embolic agents through an endovascular catheter,
with the intent of permanently/temporary exclude the underlying RVI from the renal vascular bed.
Recently,
as the consequence of the advances in interventional techniques,
such as an improved image quality,
the introduction of micro-catheters and more controllable embolic agents,
super-selective RAE has emerged as a mini-invasive and effective approach for RVI management in haemodynamically stable patients,
ensuring a good parenchymal preservation.
However,
the wide availability of materials prevents a univocal consensus on the technique and embolizing agent(s) to be used in the various possible situations.