Article

Selective Arterial Embolization of Angiomyolipomas: A Comparison of Smaller and Larger Embolic Agents

Department of Urology, University of California, San Francisco, San Francisco, California 94143, USA.
The Journal of urology (Impact Factor: 4.47). 09/2011; 186(3):921-7. DOI: 10.1016/j.juro.2011.04.082
Source: PubMed

ABSTRACT

Selective transarterial embolization for renal angiomyolipomas is effective in preventing or limiting hemorrhage and preserving normal parenchyma. Data are insufficient regarding the safety and efficacy of embolic agents. We compared transarterial embolization of angiomyolipomas using embolic agents of different sizes.
We performed a retrospective review of all transarterial angiomyolipoma embolizations from 1999 to 2010, and evaluated demographics, procedural data, embolization response and outcomes comparing smaller (less than 150 microns) and larger (more than 150 microns) embolic agents.
Overall 48 patients underwent 66 embolization procedures for 72 angiomyolipomas. Smaller agents were used more commonly (58%). Age, gender, indications, pre-embolization angiomyolipoma size and prevalence of tuberous sclerosis were similar between the groups. Angiomyolipomas decreased a mean±SD 25%±18% after embolization with no differences between the groups (p=0.24). There were 10 angiomyolipomas that required 14 repeat embolizations (median 14 months). Repeat embolization of the same mass was almost sixfold more likely in those embolized with smaller agents (OR 5.88, 95% CI 1.64-20.8, p=0.002). Complications were similar between the groups, although 2 of 3 patients with acute respiratory distress underwent embolization with smaller agents. Patients with tuberous sclerosis had similar angiomyolipoma size, decrease in angiomyolipoma size, followup, complications and need for repeat embolization. Practice patterns changed regarding embolization agent size during the study period.
Angioembolization with larger embolic agents is associated with higher long-term efficacy compared to smaller agents. Due to concerns for serious pulmonary complications, we no longer use agents smaller than 150 microns. Prospective studies are necessary to evaluate the optimal embolization technique to achieve durable outcomes without increasing patient morbidity.

    • "The small size microparticles (< 150 ) seem less effective than the large ones (> 150 ), with a risk of re-embolisation that is six times higher [89]. Three cases of respiratory distress with pulmonary hypertension after embolisation with microparticles less than 500 [89] and five cases of fatal pulmonary embolism after embolisation of hepatic masses with microparticles of 40 to 120 have been described 102—104. It, therefore, seems prudent to use microparticles that are greater than 500 for which no complications of this type have been reported. "
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    ABSTRACT: To review existing literature and deduce guidelines for the management of renal disease in patients with tuberous sclerosis complex (TSC). After review of literature, a core panel of five physicians wrote a draft that was evaluated by 14 reviewers who used a 9-level scale (1: total disagreement; 9: total agreement). The guidelines were then reformulated until each item received a median score superior or equal to 8. Forty-eight to 80 % of TSC patients have significant renal involvement including angiomyolipomas (AMLs), cysts, malignant tumors and renal insufficiency. It is recommended to perform an abdominal ultrasound (and serum creatinine if abnormal ultrasound) when TSC is diagnosed. This work-up will be repeated every 3-5years if normal. Associated autosomal dominant polycystic kidney disease must be suspected in case of numerous and large cysts. After the age of 20, follow-up should use computed tomography (CT) or MRI that are more precise than ultrasound for the measurement of AMLs. Biopsy of a renal mass should be discussed in case of calcifications, necrosis or rapid growth. Females with TSC should undergo screening for pulmonary lymphangioleiomyomatosis by CT at the age of 18, and, if negative at the age of 30-40. Acute bleeding should be treated with percutaneous embolization. Asymptomatic angiomyolipomas with several risk factors (size>80mm, predominant vascular component, micro-aneurysms) should undergo prophylactic treatment, if possible using embolization. The role of mTOR inhibitors in the management of angiomyolipomas needs to be defined. Standardization of follow-up and treatment is necessary to improve the management of TSC renal involvement.
    No preview · Article · Jun 2012 · Progrès en Urologie
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    ABSTRACT: We review our single center experience in the management of renal angiomyolipoma (AML) in patients who were treated with active surveillance (AS) or invasive treatment protocols. A prospectively evaluated database was reviewed, and we identified 91 patients with the diagnosis of renal AML who presented between June 1985 and February 2009. Patient characteristics, clinical presentation, treatment modalities, and patient outcomes were evaluated. Patients on AS were analyzed for successful completion of the surveillance protocol considering age, symptomatic presentation, and tumor size as potential predictors of invasive treatment. A total of 91 patients with AMLs were identified. The mean patient age was 57 years. Seventy-three (83.9%) patients presented incidentally, and 14 (16%) patients were symptomatic at presentation. Forty-five patients were treated with AS, 4 underwent embolization, and 38 patients had extirpative surgery. After a median follow-up of 54.8 months (range 0.2-211.7 mos), there was a mean growth rate of 0.088 cm/year in the group who were treated with AS. AS failed in three patients. Two patients had retroperitoneal bleeding during the observation period, and one patient manifested an expeditious growth rate of 0.7 cm/year and underwent a radical nephrectomy. AML is a renal tumor that usually exhibits a benign course. Surgical removal and embolization are the standard invasive treatment modalities. AS for AMLs is associated with a slow and consistent growth rate (0.088 cm/year), typically has minimal morbidity, and is a reasonable option in selected patients. Symptomatic presentation and size (> 3 cm) are not predictive for necessitating an invasive procedure.
    Full-text · Article · Oct 2010 · Journal of endourology / Endourological Society
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    ABSTRACT: Purpose To review existing literature and deduce guidelines for the management of renal disease in patients with tuberous sclerosis complex (TSC). Patients After review of literature, a core panel of five physicians wrote a draft that was evaluated by 14 reviewers who used a 9-level scale (1: total disagreement; 9: total agreement). The guidelines were then reformulated until each item received a median score superior or equal to 8. Results Forty-eight to 80 % of TSC patients have significant renal involvement including angiomyolipomas (AMLs), cysts, malignant tumors and renal insufficiency. It is recommended to perform an abdominal ultrasound (and serum creatinine if abnormal ultrasound) when TSC is diagnosed. This work-up will be repeated every 3–5 years if normal. Associated autosomal dominant polycystic kidney disease must be suspected in case of numerous and large cysts. After the age of 20, follow-up should use computed tomography (CT) or MRI that are more precise than ultrasound for the measurement of AMLs. Biopsy of a renal mass should be discussed in case of calcifications, necrosis or rapid growth. Females with TSC should undergo screening for pulmonary lymphangioleiomyomatosis by CT at the age of 18, and, if negative at the age of 30–40. Acute bleeding should be treated with percutaneous embolization. Asymptomatic angiomyolipomas with several risk factors (size > 80 mm, predominant vascular component, micro-aneurysms) should undergo prophylactic treatment, if possible using embolization. The role of mTOR inhibitors in the management of angiomyolipomas needs to be defined. Conclusion Standardization of follow-up and treatment is necessary to improve the management of TSC renal involvement.
    No preview · Article · Jun 2012
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