Renal cortical retention of contrast medium on delayed CT and nephropathy following transcatheter arterial chemoembolisation in patients with high serum creatinine level

Evaluation of the renal parenchymal retention of iodinated contrast agent during follow-up computed tomography performed one day after undergoing contrast-enhanced computed tomography

PURPOSE

To examine the frequency and patterns of renal parenchymal retention of iodinated contrast agent during follow-up computed tomography (CT) performed one day after undergoing contrast-enhanced CT and to evaluate the association with the renal function before and after contrast-enhanced CT.

MATERIALS AND METHODS

This retrospective study included 55 patients who underwent follow-up CT the day after contrast-enhanced CT had been performed. Two radiologists categorized the retention patterns on a scale of 0-6 (0: no retention, 1: diffuse parenchymal, 2: diffuse cortical, 3: subcapsular tiny nodular, 4: cortical wedge-shaped, 5: medullary focal, 6: renal pelvic). In addition, we collected the patients' clinical data, including the development of contrast-induced nephropathy (CIN).

RESULTS

A total of 37 patients (67 %) showed retention of contrast agent in the kidney (retention group), while 18 did not (non-retention group). A diffuse parenchymal pattern and renal pelvis pattern were the most common. High levels of creatinine (Cre) and blood urea nitrogen (BUN) before contrast-enhanced CT were significantly associated with the retention in the kidney (p = 0.018, 0.006, respectively). The frequency of the development of CIN was significantly higher (p = 0.021) in the retention group (10/37) than in the non-retention group (0/18). A diffuse parenchymal pattern and diffuse cortical pattern were significantly more common in patients with CIN than in those without CIN (p = 0.003, p = 0.045, respectively).

CONCLUSION

Renal parenchymal retention of iodinated contrast agent the day after contrast-enhanced CT was a frequently recognized finding and was associated with renal dysfunction. This finding, especially diffuse parenchymal and cortical patterns, may be a potential biomarker of CIN development.

Postprocedure clinical management for the interventional radiologist

Interventional procedures for oncology patients are being used more frequently in the front line and palliative setting. It is important that interventional radiologists familiarize themselves with some of the frequently encountered symptoms and potential complications and develop guidelines to help manage and sometimes prevent these complications from occurring. Unfortunately, there is not much data to support various supportive measures specifically for the post-procedural patient. However, by extrapolating the information available for the management of systemic chemotherapy patients, as well as discussing the steps that can be taken to avoid certain complications like acute renal failure, we as oncologists and interventional radiologists can better care for this unique and often complicated patient population.

High-risk situations and procedures

With the wider use of imaging and interventional techniques that require the use of iodinated contrast media in seriously ill patients, many clinical situations occur where patients may be at increased risk for contrast-induced nephropathy (CIN). There is little guidance for clinicians in these areas. The aim of this review is to assess the available literature. Acute renal failure is a common complication following coronary artery bypass surgery, and exposure to contrast medium may increase the risk for this condition, although there is insufficient evidence to make a definitive statement. Evidence is also limited for patients with liver disease: in those undergoing transarterial chemoembolization, cirrhosis may be a risk factor for renal failure. There is some evidence that periprocedural hypotension may be a risk factor for CIN after percutaneous coronary intervention, but no published information was identified on the significance of shock or hypotension in other groups of patients. The published evidence on the risk of CIN in renal transplant recipients is inconsistent. In emergency situations, the course of action is usually dictated by clinical circumstances; the renal status of a patient is likely to be unknown and it is important to ensure adequate volume expansion, especially after the procedure. In all clinical situations that are potentially associated with a high risk for CIN, the decision to administer contrast medium is a matter for clinical judgment, based on the clinical status of the patient and the expected benefits of the investigation or procedure.

Pathophysiology of contrast-induced nephropathy

Contrast-induced nephropathy (CIN) is the third leading cause of acute kidney injury in hospitalized patients and is associated with significant patient morbidity. The pathogenesis of CIN is complex and not fully understood, but iodinated contrast agents induce intense and prolonged vasoconstriction at the corticomedullary junction of the kidney. Moreover, high-osmolar dyes directly impair the autoregulatory capacity of the kidney through a loss of nitric oxide production. These effects, coupled with direct tubular toxicity of contrast media, lead to overt acute tubular necrosis and the syndrome of CIN.