[Contribution of curative and preventive embolization for renal angiomyolipomas treatment]

Radiologic and clinical results of transarterial ethanol embolization for renal angiomyolipoma

OBJECTIVE

We sought to determine the efficacy and safety of selective arterial embolization for renal angiomyolipoma (AML) using ethanol alone or ethanol with additional embolic materials and to analyze the factors influencing safety and efficacy.

METHODS

One hundred nineteen AMLs treated with embolization were included retrospectively during a 15-year period. Technical, radiologic, and clinical success were recorded and risk factor analysis was performed. Complications on follow-up images, post-embolization syndrome (PES), major complications, and changes in renal function were also evaluated.

RESULTS

Technical success was achieved in 106 of 119 tumors. Tumor size significantly decreased after treatment (reduction rate: 55%). Significant risk factors for tumor reduction included tumor enhancement on preprocedural CT and residual tumor staining. Radiologic success was achieved in 114 of 119 tumors (risk factor: residual tumor staining), and clinical success was achieved in 22 of 23 patients. Complications on follow-up images occurred in 40 of 119 tumors, and PES occurred in 53 of 104 patients. No major complications occurred. There were no cases of renal function impairment.

CONCLUSION

Selective transarterial embolization using ethanol alone or ethanol with additional embolic materials reduced AML size, alleviated symptoms, and can be performed safely without permanent impairment.

KEY POINTS

• Percutaneous transarterial ethanol embolization reduces AML size and alleviates symptoms. • Embolization can be performed safely without permanent impairment of renal function.

Selective arterial embolization of symptomatic and asymptomatic renal angiomyolipomas: a retrospective study of safety, outcomes and tumor size reduction

BACKGROUND

Angiomyolipoma (AML) is the most common renal benign tumor. Treatment should be considered for symptomatic patients or for those at risk for complications, especially retroperitoneal bleeding which is correlated to tumor size, grade of the angiogenic component and to the presence of tuberous sclerosis complex (TSC). This study reports our single-center experience with the use of selective arterial embolization (SAE) in the management of symptomatic and asymptomatic renal AMLs.

METHODS

In this retrospective mono-centric study, all demographic and imaging data, medical records, angiographic features, outpatient charts and follow-up visits of patients who underwent prophylactic or emergency SAE for AMLs between January 2005 and July 2016 were reviewed. Tumor size and treatment outcomes were assessed at baseline and after the procedure during follow-up. Computed tomography (CT), magnetic resonance imaging (MRI) or ultrasonography was used to evaluate AML shrinkage. Renal function was measured pre- and post-procedure.

RESULTS

Twenty-three patients (18 females, 5 males; median age, 45 years; range, 19-85 years) who underwent SAE either to treat bleeding AML (n=6) or as a prophylactic treatment (n=17) were included. Overall, 34 AMLs were embolized. TSC status was confirmed for 6 patients. Immediate technical success rate was 96% and 4 patients benefitted from an additional procedure. Major complications occurred in 3 patients and minor post-embolization syndrome (PES) in 14 patients. The mean AML size reduction rate was 26.2% after a mean follow-up was 20.5 months (range, 0.5-56 months), and only non-TSC status was significantly associated with better shrinkage of tumor (P=0.022). Intralesional aneurysms were significantly more frequent in patients with hemorrhagic presentation (P=0.008). There was no change in mean creatinine level after SAE.

CONCLUSIONS

SAE is a safe and effective technique to manage renal AMLs as a preventive treatment as well as in emergency setting, with significant reduction in tumor size during follow-up. A multidisciplinary approach remains fundamental, especially for TSC patients. In addition to size, the presence of intralesional aneurysms should be considered in any prophylactic treatment decision.

Long-term results of preventive embolization of renal angiomyolipomas: evaluation of predictive factors of volume decrease

OBJECTIVES

To evaluate the efficacy of selective arterial embolization (SAE) of angiomyolipomas based on the percentage volume reduction after embolization and to identify predictive factors of volume decrease.

METHODS

Patients receiving prophylactic SAE of renal angiomyolipomas were included retrospectively over 3 years. The volume change after SAE and haemorrhagic or surgical events were recorded. Initial tumour volume, percentage tumour fat content, mean tumour density, embolic agent used, number of angiomyolipomas and tuberous sclerosis disease were evaluated as predictive factors of volume decrease.

RESULTS

A total of 19 patients with 39 angiomyolipomas were included with median follow-up of 28 months (interquartile range 21-37 months). All treatments were technically successful (92% primary and 8% secondary). No distal bleeding or any increase in size or surgical nephrectomy after SAE was recorded. Mean volume reduction was 72% (±24%). Volumes before SAE (R(2) = 0.276; p = 0.001), percentage fat content (R(2) = 0.612; p < 0.0001) and mean angiomyolipoma density (R(2) = 0.536; p < 0.0001) were identified as predictive factors of volume decrease. In multivariate regression, only percentage fat content influenced volume decreases.

CONCLUSIONS

SAE is an efficient treatment for angiomyolipoma devascularisation and volume reduction. A significant reduction of volume is modulated by the initial volume and tissue composition of the tumour.

KEY POINTS

• Selective arterial embolization is effective for angiomyolipoma devascularisation and volume reduction • Volume reduction depends of initial volume and tissue composition of the tumour • Selective arterial embolization is a low radiation treatment.

[Giant renal angiomyolipoma with right heart failure]

We report the case of a 63-year-old woman presenting a 26cm right renal angiomyolipoma with intratumoral arteriovenous fistula responsible for a high-output right heart failure. A radical surgical treatment after preoperative embolization allowed rapid improvement of cardiac symptoms with an uneventful postoperative course.