Can we predict the existence of extrarenal feeders to renal angiomyolipomas?
To identify factors predicting the presence of extrarenal feeders to renal angiomyolipomas (AMLs)
This is a retrospective study of 44 patients with 58 renal AMLs embolized in our department. Arteriography obtained during embolization and CT angiography obtained before and after embolization were reviewed to characterize AMLs with and without extrarenal feeders. Tumor characteristics were compared between the two groups. Simple logistic regression and ROC curve analysis were performed. P < 0.05 was considered to be statistically significant.
Of the 58 AMLs reviewed, 29% had extrarenal arteries and 71% did not. AMLs with extrarenal feeders were significantly larger than those without, in terms of volume (median, 368 mL versus 109 mL, p < 0.0002) and the largest diameter (mean, 12.0 cm versus 7.7 cm, p < 0.0001). Patient age, presence of tuberous sclerosis complex or sporadic lymphangioleiomyomatosis, and tumor location did not differ between the groups. The largest diameter and volume had similar predictive values for the presence of extrarenal feeders (AUC, 0.83 versus 0.82, p = 0.673). Extrarenal feeders were present in 0%, 21%, and 79% of the AMLs ≤ 6.5 cm, AMLs 6.6–10.5 cm, and AMLs > 10.5 cm, respectively.
AML size correlates with the presence of extrarenal feeders, with the largest diameter and volume being significant predictors. AMLs > 10.5 cm had a high chance of extrarenal feeders, making it mandatory to search for feeders to them in order to avoid incomplete embolization; AMLs ≤ 6.5 cm did not have extrarenal feeders, making a search for them unnecessary in these cases.
• The presence of extrarenal feeders to renal angiomyolipoma is associated with tumor size, but not with patient age, concomitant disease, or tumor location.
• The largest diameter and volume predict the presence of extrarenal feeders to AML, with similar predictive values.
• AMLs > 10.5 cm have a high chance (79%) of extrarenal feeders, making it mandatory to search for feeders to them in order to avoid incomplete embolization; AMLs ≤ 6.5 cm do not have extrarenal feeders, making a search for them unnecessary in these cases.
KeywordsAngiomyolipoma Arteries Angiography Endovascular procedures Kidney neoplasms
Renal arterial branches
Transcatheter arterial embolization
Tuberous sclerosis complex
The authors state that this work has not received any funding.
Compliance with ethical standards
The scientific guarantor of this publication is Ryohei Kuwatsuru.
Conflict of interest
The authors of this manuscript declare no relationships with any companies, whose products or services may be related to the subject matter of the article.
Statistics and biometry
One of the authors has significant statistical expertise.
Written informed consent was waived by the Institutional Review Board.
Institutional Review Board approval was obtained.
Study subjects or cohorts overlap
Some study subjects or cohorts have been previously reported in Kato H, Kuwatsuru R, Inoue T, Okada S, Aida M, Yamashiro Y (2018) Superselective Transcatheter Arterial Embolization for Large Unruptured Renal Angiomyolipoma in Lymphangioleiomyomatosis. J Vasc Interv Radiol 29:958–65.
• Performed at one institution
- 18.Hoshii T, Morita S, Ikeda Y, Hasegawa G, Nishiyama T (2017) Laparoscopic retroperitoneal nephron-sparing surgery without renal artery clamping with preoperative selective arterial embolization for management of right renal angiomyolipoma of diameter 10 cm: a case report. J Endourol Case Rep 3:13–16CrossRefGoogle Scholar
- 19.Cai T, Rozzanigo U, Tiscione D, Dalla Palma P, Malossini G (2011) Selective arterial embolization for renal angiomyolipoma treating: the role of pain. Eur J Vasc Endovasc Surg 41:134–135Google Scholar
- 24.Bordei P, St Anothe D, Sapte E, Iliescu D (2003) Morphological aspects of the inferior suprarenal artery. Surg Radiol Anat 25:247–251Google Scholar
- 30.Stamatiou KN, Moschouris H, Marmaridou K, Kiltenis M, Kladis-Kalentzis K, Malagari K (2016) Combination of superselective arterial embolization and radiofrequency ablation for the treatment of a giant renal angiomyolipoma complicated with caval thrombus. Case Rep Oncol Med. https://doi.org/10.1155/2016/8087232