Long-term outcome of transcatheter embolization of renal angiomyolipomas due to tuberous sclerosis complex

Delayed bilateral spontaneous renal rupture after surgery for unilateral upper ureteral calculi: a case report

Spontaneous renal rupture is a rare clinical condition characterized by spontaneous bleeding in the renal subcapsular and perinephric spaces in patients without a history of trauma. It occurs mainly in pathologic kidneys and after some renal surgeries. We report a 40-year-old male patient admitted with a diagnosis of gallstones with cholecystitis due to fever and abdominal pain after unilateral ureteral calculi. The patient developed delayed right renal rupture hemorrhage during treatment, controlled after selective arterial embolization (SAE). Still, the patient developed spontaneous left renal rupture due to a systemic inflammatory response. Finally, the patient's life was saved after several selective embolizations of the renal artery. We retrospectively analyzed this case to improve our understanding of the disease.

Endovascular Interventional Radiology of the Urogenital Tract

Interventional radiology of the male urogenital system includes percutaneous and endovascular procedures, and these last consist mostly of transcatheter arterial embolizations. At the kidney level, arterial embolizations are performed mainly for palliative treatment of parenchymal tumors, for renal traumas and, less frequently, for arteriovenous fistulas and renal aneurysms and pseudoaneurysms. These latter may often require emergency intervention as they can cause renal or peri-renal hematomas or significant hematuria. Transcatheter arterial embolization is also an effective therapy for intractable severe bladder hematuria secondary to a number of neoplastic and inflammatory conditions in the pelvis, including unresectable bladder cancer and radiation-induced or cyclophosphamide-induced hemorrhagic cystitis. Endovascular interventional procedures for the penis are indicated for the treatment of post-traumatic priapism. In this article, we review the main endovascular radiological interventions of the male urogenital system, describing the technical aspects, results, and complications of each procedure at the various anatomical districts.

Evidence-based protocol-led management of renal angiomyolipoma: A review of literature

Renal angiomyolipomas (R-AMLs) are rare benign tumors, which occur sporadically and in association with genetic conditions such as tuberous sclerosis complex (TSC) and lymphangioleiomyomatosis (LAM). The key clinical concern is life-threatening hemorrhage. There is uncertainty about the optimal management strategy for patients with R-AMLs. We aim to review the evidence and provide a protocolled approach for the management of R-AMLs. A literature search of R-AML was conducted using MEDLINE and EMBASE for articles published between January 1990 and March 2020. Patient with TSC and sporadic cases were included. Treatment strategies, including active surveillance, surgery, selective arterial embolization (SAE), ablation, and systemic therapies, were reviewed. Outcomes from contemporary case series of active surveillance, surgery, and SAE were collated. There were no randomized controlled trials on this topic. The retrospective case series reviewed showed that many R-AMLs can be managed safely with active surveillance. Tumor size is the most important predictor of bleeding, and other factors such as rate of growth, women of child-bearing age, aneurysm size, and symptoms should be considered when deciding on prophylactic treatment. There is limited evidence for the traditional 4-cm cutoff for treatment, which may lead to overtreatment. The primary intervention options are SAE and surgery; whereas SAE is a less invasive option, nephron sparing surgery offers a lower risk of recurrence. Both appear to have similar morbidity, and the current evidence does not recommend one over the other in most cases. Thermal ablation has promising results but has only been trialed in small case series. Patients with TSC can be offered mammalian target of rapamycin inhibitors of which everolimus appears to cause the greatest shrinkage of tumors with an acceptable side-effect profile. R-AMLs should be assessed for their risk of bleeding. Low-risk tumors should be treated with active surveillance. High-risk tumors should be treated with SAE or surgery. Systemic treatments are the first-line of treatment for patients with TSC to preserve renal parenchyma.

Enhancing disease awareness for tuberous sclerosis complex in patients with radiologic diagnosis of renal angiomyolipoma: an observational study

Background

Tuberous Sclerosis Complex (TSC) is a genetic disorder, with renal manifestations like angiomyolipoma (AML) occurring in 70–80% of patients. AML usually cause more complications in TCS patients than in non-TSC patients. However, AML patients are not routinely investigated for TSC. Our aim was to retrospectively assess the correlation between radiologically diagnosed AML and TSC.

Methods

All patients were stratified into AML related vs. unrelated to TSC. Correlations were calculated to determine the association between age, AML, and TSC.

Results

Complete data were available for 521 patients with renal AML, in 7 of which the concurrent diagnosis of TSC was found. Younger age significantly positively correlated with the prevalence of TSC in AML patients (p <  0.01). 37 (7%) of the 521 patients were within the age-range of 18–40 years, in which TSC occurred in 6 cases, 4 (66.7%) of which presented with multiple, bilateral renal AML (p <  0.05), and 2 (33.3%) of which with a single, unilateral AML (p <  0.05). In patients with AML but without TSC, unilateral AML was found in 83.9% and bilateral AML in 16.1% (p <  0.05). Simple binary logistic regression analysis revealed bilateral AML (OR 33.0; 95% CI 3.2–344.0; p = 0.003) (but not unilateral AML (OR 0.09; 95% CI 0.01–0.88; p = 0.04)) to be a risk factor for TSC.

Conclusions

The presence of bilateral AML in patients within the age-range of 18–40 years should raise suspicion for TSC as the underlying cause. Therefore, our advice is to refer patients with multiple bilateral renal AML for further investigations regarding TSC.

Renal function, complications, and outcomes of a reduction in tumor size after transarterial embolization for renal angiomyolipomas: a meta-analysis

OBJECTIVE

The present study aimed to evaluate renal function, complications, and changes in tumor size after transarterial embolization for patients with renal angiomyolipomas.

METHODS

We performed a meta-analysis of transarterial embolization in patients with renal angiomyolipomas from January 1994 to April 2018. Endpoints of interest were the estimated glomerular filtration rate, serum creatinine levels, blood urea nitrogen levels, complications, and reduction of tumors.

RESULTS

A total of 30 studies comprising 653 patients were included. A total of 32.0% of patients were treated by urgent transarterial embolization for spontaneous ruptured renal angiomyolipomas. Other patients sought to relieve symptoms or received embolism prophylactically. The estimated glomerular filtration rate showed no significant difference between before and after embolization. In 363 patients with data on complications, post-embolization syndrome occurred most frequently (54.0%). Only 16 (4.4%) patients had major complications. The diameter of sporadic angiomyolipomas was reduced by a mean of 2.09 cm (95% confidence interval [CI], 0.73-3.45 cm; I2 = 29.3%) and they were reduced in size by 30.0% (95% CI, 16.0%-44.0%; I2 = 27.9%).

CONCLUSIONS

Transarterial embolization of renal angiomyolipomas affects renal function preservation, with a low complication rate. Transarterial embolization is useful for sporadic and tuberous sclerosis complex-related angiomyolipomas.

Tuberous sclerosis complex: new insights into clinical and therapeutic approach

Tuberous sclerosis complex (TSC) is a complex disease with many different clinical manifestations. Despite the common opinion that TSC is a rare condition, with a mean incidence of 1/6000 live births and a prevalence of 1/20,000, it is increasingly evident that in reality this is not true. Its clinical sequelae span a range of multiple organ systems, in particular the central nervous system, kidneys, skin and lungs. The management of TSC patients is heavily burdensome in terms of time and healthcare costs both for the families and for the healthcare system. Management options include conservative approaches, surgery, pharmacotherapy with mammalian target of rapamycin inhibitors and recently proposed options such as therapy with anti-EGFR antibody and ultrasound-guided percutaneous microwaves. So far, however, no systematically accepted strategy has been found that is both clinically and economically efficient. Thus, decisions are tailored to patients' characteristics, resource availability and clinical and technical expertise of each single center. This paper reviews the pathophysiology and the clinical (diagnostic-therapeutic) management of TSC.

Effect of everolimus treatment for regrown renal angiomyolipoma associated with tuberous sclerosis complex after transcatheter arterial embolization

BACKGROUND

The aim of this study was to evaluate the effects and the utility of second-line everolimus treatment for regrown renal angiomyolipoma (AML) with tuberous sclerosis complex (TSC) after transcatheter arterial embolization (TAE).

METHODS

We investigated a total of 14 patients who underwent second-line everolimus treatment for TSC-AML that regrew after TAE, and assessed their effects and adverse events. Everolimus treatment was performed for AML with a maximum diameter of 4 cm. To determine the reduction ratio of AML, the volume of AML was measured using multislice helical computed tomography. Adverse events were evaluated according to CTCAE v4.0-JCOG. We further compared the treatment effect and adverse events with those in patients receiving first-line everolimus treatment.

RESULTS

The AML volume decreased in all patients, with a ≥ 50% volume decrease in 57% (8 of 14) of the cases, and the mean reduction rate was 53%. We observed no significant difference in the mean reduction rate of AML between second-line everolimus treatment for regrown TSC-AML after TAE and first-line everolimus treatment for TSC-AML. The adverse events were mild and consistent with those reported in our previous study.

CONCLUSION

Although further studies are needed, everolimus appears to be effective as second-line treatment for TSC-AML that regrew after TAE and a beneficial treatment option for TSC-AML.

An update on recent developments in rupture of renal angiomyolipoma

BACKGROUND

Renal angiomyolipoma (AML) is a common benign tumor of the kidney. The main complication of AML is retroperitoneal hemorrhage caused by AML rupture, which can be severe and life threatening. The risk of AML rupture used to be determined by tumor size. However, these criteria have been challenged by series of clinical studies and case reports, suggesting prediction AML rupture based on tumor size is not always reliable.

METHODS

The authors searched PubMed using "angiomyolipoma," "AML," and "rupture" and reviewed relevant studies. The authors investigated the risk factors of AML rupture using the retrieved literature. The authors also summarized current modalities to evaluate and manage AML.

RESULTS

It is established that risk of AML rupture is associated with lesion size. However, genetic abnormality, aneurysm formation, and pregnancy are also risk factors for tumor rupture. Thus, the prediction of AML rupture should be based on a more comprehensive risk assessment system. The management of renal AML and tumor rupture was also discussed in the present paper.

CONCLUSION

The risk of AML rupture is associated with but not exclusive to lesion size. Any decision to intervene AML must be based on multiple factors including risk, symptoms, and auxiliary findings.

Are We Overtreating Renal Angiomyolipoma: A Review of the Literature and Assessment of Contemporary Management and Follow-Up Strategies

Renal angiomyolipoma (AML) are benign tumours composed of fat, muscle, and disorganised blood vessels. Historic treatment algorithms for sporadic AML based on size fail to consider additional risk factors such as tumour vascularity and pseudoaneurysm formation. As AML is now predominantly incidental, rupture is rare and its mortality low. The recent publication of the largest longitudinal series to date also suggest that growth is uncommon, challenging existing surveillance paradigms. The evidence assessing treatment strategies in AML are reviewed, with particular emphasis on incidental sporadic AML. The relative merits of various AML treatments are discussed, and areas of clinical uncertainty highlighted.

mTOR Inhibitors in Children: Current Indications and Future Directions in Neurology

The mammalian/mechanistic target of rapamycin (mTOR) pathway is a key signaling pathway that has been implicated in genetic epilepsy syndromes, neurodegenerative diseases, and conditions associated with autism spectrum disorder and cognitive impairment. The mTOR pathway has become an exciting treatment target for these various disorders, with mTOR inhibitors such as rapamycin being studied for their potential therapeutic applications. In particular, tuberous sclerosis complex (TSC) is a genetic disorder resulting from overactivation of the mTOR pathway, and pharmacologic therapy with mTOR inhibitors has emerged as a viable treatment option for the systemic manifestations of the disease. In this review, we discuss the approved indications for mTOR inhibitors in TSC, the potential future applications of mTOR inhibitors in TSC and other neurological conditions, and the safety considerations applicable to mTOR therapy in the pediatric population.

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.

Spontaneous rupture of renal angiomyolipoma during pregnancy

A renal angiomyolipoma (AML) is a rare benign tumour of kidney origin. Pregnancy is known to be associated with an increased risk of tumour rupture causing hypovolaemic shock, which is usually managed surgically or through an embolisation procedure. However, having surgery during pregnancy predisposes the mother to a preterm delivery, and the unknown influences of radiation exposure to the fetus make the management of such cases very challenging. A 30-year-old pregnant woman had a sudden onset of gross haematuria at the 20th week of her pregnancy. The MRI showed a 10 cm mass suggestive of AML in the left kidney, with evidence of an intrarenal haematoma. To avoid an iatrogenic preterm delivery and unnecessary fetal exposure to radiation, conservative management was conducted until 34 weeks of gestation, when she came to our hospital reporting of flank pain. An endovascular treatment was performed immediately after an emergency caesarean delivery.

Urgent transcatheter arterial embolization for the treatment of ruptured renal angiomyolipoma with spontaneous hemorrhage

Background The rich neovascularization of renal angiomyolipoma (AML) has a tendency for spontaneous rupture with subsequent hemorrhage. Nephrectomy or nephron-sparing surgery has rarely been used as a primary treatment in urgent situations. Purpose To evaluate the safety and long-term outcomes for patients treated by urgent transcatheter arterial embolization (TAE) for spontaneous ruptured renal AML with severe hemorrhage. Material and Methods A retrospective evaluation was performed of 25 renal AML cases with spontaneous hemorrhage confirmed by imaging. Polyvinyl alcohol (PVA) particles and coils of multiple sizes were used to embolize the spontaneous renal AML ruptures. Results The technical success rate of TAE was 96% (24/25). One week post-TAE, 1 patient with recurrent hemorrhage underwent emergency nephrectomy. Minor complications affected 16 patients with post-embolization syndrome; 15 patients resolved using conservative measures and one patient received nephrectomy post TAE 1 week later. All patients were followed up for 24-72 months (median, 50.2 months). Surgical treatment was avoided for 92% (23/25) of patients, and the re-embolization rate was 0% at 2 years post TAE. In the 23 patients without surgical treatment, the mean maximum diameter of renal AML was reduced from 12.4 ± 5.5 cm to 6.3 ± 2.5 cm and no hemorrhage occurred during follow-up. Conclusion Urgent TAE is a technically feasible and minimally invasive procedure for controlling severe hemorrhage and preservation of renal function following spontaneous ruptured renal AML.

The impact of renal angiomyolipoma on estimated glomerular filtration rate in patients with tuberous sclerosis complex

BACKGROUND

There is a growing concern that renal impairment may develop in patients with renal angiomyolipomas (AMLs) associated with tuberous sclerosis complex (TSC) as a consequence of the disease itself and/or the interventions to mitigate the risk of hemorrhage.

OBJECTIVE

To assess the estimated glomerular filtration rate (eGFR) in patients with bilateral renal AMLs and the impact of tumor burden and intervention on renal function.

DESIGN

Retrospective study.

SETTING

Urology department of a tertiary care hospital.

PATIENTS AND METHODS

All adult patients (>=18 years of age) with TSC-associated renal AMLs seen from October 1998 to June 2015. We included only patients with bilateral tumors or solitary kidneys at the last follow-up.

MAIN OUTCOME MEASURES

The eGFR, renal volume, and number and type of interventions.

RESULTS

We identified 12 patients (median age 27.6, interquartile range 23.7-39.9 years), a median follow-up period of 1266 days (33-3133), and a median renal size of 454.7 mL (interquartile range 344.7-1016.9 on the right side; 558.1 mL, interquartile range 253.7-1001.4 on the left). In 11 (91.7%) patients, the eGFR was > 60 mL/min/1.77 m2. Six patients had three total nephrectomies, one had a contralateral partial nephrectomy, and seven had selective arterial embolizations. Intervention was associated with a significantly reduced eGFR. The renal size did not correlate with the eGFR.

CONCLUSIONS

TSC-associated renal AMLs may attain a large size but normal renal function is maintained in 92% of patients. Interventions to mitigate the risk of hemorrhage are associated with decreased renal function.

LIMITATIONS

The renal size was used as a surrogate for tumor size. Other limitations were the limited number of patients and lack of split renal function testing.

Optimal treatment of tuberous sclerosis complex associated renal angiomyolipomata: a systematic review

Renal angiomyolipomata associated with tuberous sclerosis complex are often bilateral, multiple and progressive. They cause significant morbidity and mortality in older children and adults. Surveillance and pre-emptive treatment reduce this risk. Recent research suggests treatment with mammalian target of rapamycin inhibitors is better at preventing bleeding, recurrence, and preserving renal function than percutaneous embolization.

Angiographic and volumetric effects of mammalian target of rapamycin inhibitors on angiomyolipomas in tuberous sclerosis

AIM: To investigate the angiographic and volumetric effects of mammalian target of rapamycin (mTOR) inhibitors on angiomyolipomas (AMLs) in a case series of patients with tuberous sclerosis complex.

METHODS: All patients who underwent catheter angiography prior to and following mTOR inhibitor therapy (n = 3) were evaluated. All cross-sectional imaging studies were analyzed with three-dimensional volumetrics, and tumor volume curves for all three tissue compartments (soft tissue, vascular, and fat) were generated. Segmentation analysis tools were used to automatically create a region of interest (ROI) circumscribing the AML. On magnetic resonance images, the “fat only” map calculated from the in- and opposed-phase gradient recalled echo sequences was used to quantify fat volume within tumors. Tumor vascularity was measured by applying a thresholding tool within the ROI on post-contrast subtraction images. On computed tomography images, volume histogram analysis of Hounsfield unit was performed to quantify tumor tissue composition. The angiography procedures were also reviewed, and tumor vascularity based on pre-embolization angiography was characterized in a semi-quantitative manner.

RESULTS: Patient 1 presented at the age of 15 with a 6.8 cm right lower pole AML and a 4.0 cm right upper pole AML. Embolization was performed of both tumors, and after a few years of size control, the tumors began to grow, and the patient was initiated on mTOR inhibitor therapy. There was an immediate reduction in the size of both lesions. The patient then underwent repeat embolization and discontinuation of mTOR inhibition, after which point there was a substantial regrowth in both tumors across all tissue compartments. Patient 2 presented at the age of 18 with a right renal AML. Following a brief period of tumor reduction after embolization, she was initiated on mTOR inhibitor therapy, with successful reduction in tumor size across all tissue compartments. As with patient 1, however, there was immediate rebound growth following discontinuation of inhibitor therapy, without sustained control despite repeat embolization. patient 3 presented at the age of 5 with a left renal AML and underwent two embolization procedures without lasting effect prior to starting mTOR inhibition. As with patients 1 and 2, following discontinuation of therapy, there was immediate rebound growth of the tumor. Repeat embolization, however, was notable for a substantial reduction in intratumoral aneurysms and vascularity.

CONCLUSION: AML volume reduction as well as post-treatment rebound growth due to mTOR inhibitors involves all three tissue components of the tumor.

Natural History of Renal Angiomyolipoma (AML): Most Patients with Large AMLs >4cm Can Be Offered Active Surveillance as an Initial Management Strategy

BACKGROUND

The natural history of renal angiomyolipoma (AML) is unknown. Treatment recommendations are based on smaller case series, with selection bias towards symptomatic patients.

OBJECTIVE

To define the natural history of renal AML, including growth rates, size, and clinical presentation.

DESIGN, SETTING, AND PARTICIPANTS

We used a unique radiology data-mining system (Montage; Montage Healthcare Systems, Philadelphia, PA, USA) to retrospectively review the radiology database in an academic health centre between 2002 and 2013 to identify all renal AMLs. Of 2741 patients identified, 447 with 582 AMLs had three or more imaging studies suitable for analysis.

INTERVENTION

Angioembolisation, surgery, radiofrequency ablation, and mammalian target of rapamycin inhibitors.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary end point was the growth rate of untreated AMLs. We used a linear mixed-effects model to determine change in growth rate over time. We evaluated the association among growth rate, size, and patient factors as well as interventions.

RESULTS AND LIMITATIONS

The majority of untreated AMLs (>92%) had not grown at a median follow-up of 43 mo, with no difference in growth rates between AMLs ≤4 and >4cm. Most AMLs occurred in female participants (80%) and were asymptomatic (91%). Tuberous sclerosis complex (TSC) was confirmed in 3.8% (n=17) and presented at an earlier age. Median size was 1cm but was significantly larger for TSC (5.5cm; p<0.001). Interventions were performed in 5.6% of patients. Limitations of our study include the retrospective design, selection against fat-poor AMLs, and lack of histology.

CONCLUSIONS

This large, single-institution series on AMLs confirms that lesions >4cm do not require early intervention based on size alone. The vast majority are sporadic, asymptomatic, and initially harmless, with a negligible growth rate. Our findings support a policy of initial active surveillance for all asymptomatic AMLs.

PATIENT SUMMARY

We evaluated the natural history and growth rates of renal AMLs. We found no difference in growth rates between AMLs >4 and ≤4cm. Initial AS appears to be a safe management option.

Feasibility, Safety, and Efficacy of Flow-Diverting Stent-Assisted Microsphere Embolization of Fusiform and Sidewall Aneurysms

BACKGROUND

Treatment of wide-necked internal carotid artery aneurysms is frequently associated with incomplete occlusion and high recurrence rates. Furthermore, platinum coils cause strong beam-hardening artifacts, hampering subsequent image analyses.

OBJECTIVE

To assess the feasibility, safety, and efficacy of flow-diverting, stent-assisted microsphere embolization of fusiform and sidewall aneurysms in vitro and in vivo.

METHODS

Using a recirculating pulsatile in vitro flow model, 5 different aneurysm geometries (inner/outer curve, narrow/wide neck, and fusiform) were treated (each n = 1) by flow-diverting stent (FDS) implantation and subsequent embolization through a jailed microcatheter using calibrated microspheres (500-900 μm) larger than the pores of the FDS mesh. Treatment effects were analyzed angiographically and by micro computed tomography. The fluid of the in vitro model was filtered to ensure that no microspheres evaded the aneurysm. The experiment was repeated once in vivo.

RESULTS

In vitro, all 5 aneurysms were safely and completely occluded by FDS-assisted microsphere embolization. Virtually complete aneurysm occlusion was confirmed by angiography and micro computed tomography. No microspheres escaped into the circulation. The experiment was successfully repeated in 1 pig with a sidewall aneurysm generated by vessel occlusion. An embolic protection system placed distally of the FDS in vitro and in vivo (each n = 1) contained no microspheres after the embolization. Thus, no microspheres were lost in the circulation, and the use of an embolic protection system seems feasible to provide additional safety.

CONCLUSION

FDS-assisted microsphere embolization of fusiform and sidewall aneurysms is feasible and yields virtually complete aneurysm occlusion while avoiding coil-associated beam-hardening artifacts.

Treatment of renal angiomyolipoma: pooled analysis of individual patient data

Background

This study was performed to evaluate the impact of baseline characteristics and treatment methods on the outcome of sporadic renal angiomyolipoma (AML).

Methods

This was a pooled analysis of individual data of 441 patients with AML retrieved from 58 studies and 3 institutional series.

Results

Ninety-three patients underwent nephrectomy, 163 partial nephrectomy/enucleation, 128 embolisation, 19 cryoablation, 6 radiofrequency ablation, and 32 conservative treatment. Their mean follow-up period was 44.5 months. Patients who experienced major bleeding at presentation had significantly larger tumours than did those without bleeding (mean diameter, 10.1 vs. 5.9 cm, respectively; p < 0.0001). A total of 9.4 % and 26.4 % of bleeding tumours had a diameter of <4 and <6 cm, respectively. A tumour diameter of ≥8.0 cm (hazard ratio, 2.07; 95 % confidence interval, 1.20–4.77) and the treatment method (p = 0.001) were independent predictors of re-intervention. The risk of re-intervention was significantly higher after embolisation, particularly for large tumours (5-year rate of freedom from re-intervention: diameter of ≥8.0 cm, 49.2 %; diameter of <8.0 cm, 74.8 %; p = 0.018). Conservatively treated AMLs had a mean baseline diameter of 3.2 ± 2.7 cm; after 41 months, their mean diameter was 3.7 ± 3.1 cm (p = 0.109).

Conclusions

The prevalence of major bleeding is high in sporadic AMLs with a diameter of >6 cm. These results suggest that conservative treatment can be considered in AMLs of <6 cm in diameter. Among current treatment methods, embolisation was associated with a significantly higher risk of re-intervention. Further studies are needed to define risk factors for bleeding and assess the relative benefits of different treatment modalities.

Evolving Strategies in the Treatment of Tuberous Sclerosis Complex-associated Angiomyolipomas (TSC-AML)

Tuberous sclerosis complex (TSC) is a rare autosomal dominant genetic disorder characterized by the development of numerous benign tumors that occur in multiple organ systems throughout the lifetime of the affected individuals. Renal angiomyolipomas occur in up to 80% of TSC patients, and chronic kidney disease from increasing tumor burden is the primary cause of TSC-related mortality. Our review evaluates evidence for localized and systemic therapy in the management of TSC-angiomyolipomas. Urologists or nephrologists experienced in TSC disease should coordinate the care of TSC patients with renal involvement to improve care and reduce costs.

Annual review of children with tuberous sclerosis

Tuberous sclerosis complex is a complex childhood disorder characterised by the formation of hamartomas in multiple organs. Annual review of this disease is recommended to monitor the development of complications. We aim to provide a concise, evidence-based framework to assist clinicians during this annual review. We focus on the following areas: (A) what questions need to be asked during annual review, (B) which areas need emphasis on examination, (C) when is an investigation required and (D) referral to tertiary specialists and other members of the multidisciplinary team. It should also be noted that there are ongoing debates regarding screening intervals in certain areas. These include the frequency, modality of screening and degree of intervention for astrocytomas and renal angiomyolipomas. This review seeks to summarise the product of the ongoing debates, and provide evidence-based suggestions in light of the uncertainty.

Spontaneous rupture of a renal angiomyolipoma at 25 weeks of pregnancy treated with transarterial embolization: A case report and review of the literature

Treatment for ruptured renal angiomyolipoma in pregnancy requires immediate and appropriate decision-making based on the condition of the mother and fetus, and gestational age. A 37-year-old woman at 25 weeks of pregnancy presented with severe right flank pain. Computed tomography showed a ruptured right renal angiomyolipoma (8 cm in diameter). The maternal and fetal conditions were stable. Transcatheter arterial embolization was carried out electively 4 days after the rupture. Minimization of radiation exposure to the fetus was achieved by X-ray shielding for the fetus, low-dose-rate fluoroscopy, minimal angiography imaging and a color Doppler ultrasonography-guided procedure. Although threatened premature labor occurred because of post-embolization syndrome, the pregnancy was continued until cesarean section at 37 weeks of pregnancy.

Tuberous sclerosis complex

Tuberous sclerosis complex (TSC) is a neurocutaneous syndrome that can affect the brain, skin, eyes, kidneys, heart, and lungs. TSC alters cellular proliferation and differentiation, resulting in hamartomas of various organs, tumor formation, and altered neuronal migration. The phenotype is highly variable. Most individuals have seizures, commonly including infantile spasms, and there is variable intellectual disability and autism. Neonates can present with cardiac failure due to intracardiac rhabdomyomas. The likelihood of renal angiomyolipomas increases with age, and renal disease is the most common cause of death in adults with TSC. Pulmonary involvement occurs predominantly in women and carries a high morbidity and mortality. TSC is inherited as an autosomal dominant trait, but spontaneous mutations are common. A mutation of either TSC1 on chromosome 9 or TSC2 on chromosome 16 leads to dysfunction of hamartin or tuberin, respectively. These two proteins form a functional complex that modulates the mammalian target of rapamycin (mTOR) pathway. Medications that inhibit mTOR are being used to treat TSC-related tumors, and current studies are investigating whether these agents could alleviate other TSC complications. Consensus statements guide identification and optimal management of many of the TSC-related complications at diagnosis and throughout the lifespan. A multidisciplinary approach is necessary for optimal management of individuals with TSC.

Renal artery embolization-indications, technical approaches and outcomes

Owing to improvements in catheters and embolic agents, renal artery embolization (RAE) is increasingly used to treat nephrological and urological disease. RAE has become a useful adjunct to medical resuscitation in severe penetrating, iatrogenic or blunt renal traumatisms with active bleeding, and might avoid surgical intervention, particularly among patients that are haemodynamically stable. The role of RAE in pre-operative or palliative management of advanced malignant renal tumours remains debated; however, RAE is recommended as a first-line therapy for bleeding angiomyolipomas and can be used as a preventative treatment for angiomyolipomas at risk of bleeding. RAE represents an alternative to nephrectomy in various medical conditions, including severe uncontrolled hypertension among patients with end-stage renal disease, renal graft intolerance syndrome or autosomal dominant polycystic kidney disease. RAE is increasingly used to treat renal artery aneurysms or symptomatic renal arteriovenous malformations, with a low complication rate as compared with surgical alternatives. This Review highlights the potential use of RAE as an adjunct in the management of renal disease. We first compare and contrast the technical approaches of RAE associated with the various available embolization agents and then discuss the complications associated with RAE and alternative procedures.

Role of embolization in the treatment of renal masses

Renal arterial embolization (RAE) performed for the treatment of renal masses has been proven to be a safe and effective technique, with several decades of experience. RAE is well tolerated with few complications, particularly if the time interval from embolization to surgery is reduced to less than 48 hours. Review of the literature suggests that RAE is also extremely effective for palliation of symptoms in the setting of nonoperative advanced stage renal cell carcinoma. In addition, this technique plays a large role in the management of angiomyolipomas that are symptomatic or at risk of spontaneous rupture. To date, RAE has not been evaluated in a randomized controlled setting, which has contributed to its underutilization. All of these potential benefits warrant the need for prospective studies for further validation.

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.

Renoduodenal fistula after transcatheter embolization of renal angiomyolipoma

Transcatheter embolization of renal angiomyolipomas is a routinely performed, nephron-sparing procedure with a favorable safety profile. Complications from this procedure are typically minor in severity, with postembolization syndrome the most common minor complication. Abscess formation is a recognized but uncommon major complication of this procedure and is presumably due to superinfection of the infarcted tissue after arterial embolization. In this case report, we describe the formation of a renoduodenal fistula after embolization of an angiomyolipoma, complicated by intracranial abscess formation and requiring multiple percutaneous drainage procedures and eventual partial nephrectomy.

Patterns of renal angiomyolipoma regression post embolisation on medium- to long-term follow-up

OBJECTIVE

To assess the patterns of regression of renal angiomyolipoma (AML) post embolisation and report the outcomes related to the use of different embolic materials.

METHODS

A retrospective review of all patients who underwent embolisation for renal AML at our institution between January 2004 and April 2012.

RESULTS

13 patients underwent 16 episodes of embolisation. Coils were used as the primary embolisation material in 10 episodes and microspheres in 6 episodes. The size reduction rate highly correlated on CT follow-up between the two groups, with 25.6% vs 22.7% reduction at 12 months, 27.5% vs 25.1% at 24 months, 35.0% vs 33.0% at 36 months and 35.0% vs 36.8% at 48 months. During follow-up, all tumours reduced in size with one patient requiring subsequent embolisation whose tumour reduced by only 6.5% after 1 year and subsequently exhibited regrowth after 4 years. Two patients presented with rebleeding and underwent repeat embolisation. Our overall retreatment rate (23%) is well within the literature range (up to 37%). None of the patients underwent surgery.

CONCLUSION

The majority of AML shrinkage occurs within the first year following embolisation and appears to plateau after 3 years, which could have an impact on follow-up strategy. The percentage reduction at 1 year may reflect the long-term effect of embolisation with tumours demonstrating minor size reduction more likely to relapse at long-term follow-up. Embolisation of renal AML produces durable long-term results regardless of the choice of embolic agent.

ADVANCES IN KNOWLEDGE

These findings provide information to guide CT follow-up of renal AML post embolisation.

Renal angiomyolipomas in tuberous sclerosis--rare but potentially life-threatening lesions

We discuss an 18-year-old girl, diagnosed with tuberous sclerosis complex and known to have renal angiomyolipomas (AMLs) but having no regular urological follow-up, who presented with left-sided abdominal pain and haematuria on urine dipstick testing at the out-of-hours General Practitioner (GP) service. She was diagnosed as having urinary tract infection/pyelonephritis and discharged with simple analgesia and antibiotics. Subsequent imaging of her renal tract demonstrated multiple large AMLs with evidence of recent bleeding, which required arterial embolisation.

[Guidelines for the management of tuberous sclerosis complex renal disease]

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 3-5years 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.

CONCLUSION

Standardization of follow-up and treatment is necessary to improve the management of TSC renal involvement.

An Australian tuberous sclerosis cohort: are surveillance guidelines being met?

AIM

This study aims to describe the phenotypic and genotypic characteristics of 45 Australian patients with tuberous sclerosis complex (TSC), to assess risk factors for intellectual disability, to compare patients with TSC1 and TSC2 mutations and to assess adherence to surveillance recommendations.

METHODS

Phenotypic features were recorded in 45 patients who fulfilled established criteria for a diagnosis of definite TSC. All patients underwent TSC1 and TSC2 sequencing and multiplex ligand probe amplification. Features were compared in patients with TSC1 mutations versus TSC2 mutations. Recent surveillance was recorded at the point of first contact. Surveillance adherence was compared in the adult and paediatric cohorts.

RESULTS

This cohort consisted of 31 children and 14 adults with definite TSC. The rates of TSC manifestations and TSC1 and TSC2 mutation detection rates were consistent with previous studies. There was a trend towards greater severity for patients with TSC2 mutations compared with their TSC1 counterparts, particularly for autistic spectrum disorder, but this did not reach statistical significance. The presence of seizures was shown to be a risk factor for intellectual disability (P < 0.001). Overall, 12/45 patients (27%) were not undergoing recommended surveillance at the point of first contact. Surveillance guidelines were being followed in 3/31 (11%) children compared with 9/14 (64%) adult patients (P < 0.05).

CONCLUSIONS

The genotypic and phenotypic characteristics of this TSC cohort were consistent with previous studies. Surveillance rates in adult patients were significantly lower than in paediatric patients. This highlights the need for patients with TSC to undergo a focussed transition into adult services.

Clinically relevant imaging in tuberous sclerosis

Tuberous sclerosis (TS), also known as Bourneville disease or Bourneville–Pringle disease, is an autosomal dominant genetic disorder classically characterized by the presence of hamartomatous growths in multiple organs. TS and tuberous sclerosis complex (TSC) are different terms for the same genetic condition. Both terms describe clinical changes due to mutations involving either of the two genes named TSC1 and TSC2, which regulate cell growth. The diagnosis of TSC is established using diagnostic criteria based on clinical and imaging findings. Routine screening and surveillance of patients with TSC is needed to determine the presence and extent of organ involvement, especially the brain, kidneys, and lungs, and identify the development of associated complications. As the treatment is organ specific, imaging plays a crucial role in the management of patients with TSC.

Selective arterial embolization of angiomyolipomas: a comparison of smaller and larger embolic agents

PURPOSE

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.

MATERIALS AND METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Prophylactic embolization of renal angiomyolipomas: evaluation of therapeutic response using CT 3D volume calculation and density histograms

PURPOSE

To evaluate the efficacy and tolerance of prophylactic embolization of angiomyolipomas (AMLs) and to analyze the therapeutic response by using three-dimensional 3D volume calculation and 3D quantification of fatty and angiomyogenic components during computed tomography (CT) follow-up.

MATERIALS AND METHODS

Over a 51-month period, 30 patients with 34 AMLs (mean diameter, 82 mm ± 37; range, 30-173 mm) underwent 37 prophylactic embolization procedures. The protocol included supraselective arterial embolization with a combination of absolute alcohol, microparticles, and coils. Mean clinical and imaging follow-up were 20.5 and 14.5 months, respectively. The 3D volume calculation and density histograms were retrospectively analyzed for treatment evaluation.

RESULTS

Four technical failures were observed (11%), with one successful secondary reattempt, resulting in 31 AMLs (91.2%) being embolized. Thirty (88.2%) had CT follow-up and were included in the analysis. Embolization was complete after a single procedure for 25 AMLs (83%) and required two procedures in two cases. Three AMLs had incomplete embolization and were scheduled for a second procedure. Mean volume reductions were 43% ± 32 for AMLs followed for 1-6 months after embolization and 81% ± 19 for the 12 AMLs followed for more than 1 year. The volume reduction after embolization was significantly correlated with the AML initial composition, with fat-rich AMLs showing a much smaller reduction of size than predominantly angiomyomatous AMLs (P < .05).

CONCLUSIONS

Prophylactic embolization allows significant reduction of AML volume with a high success rate. Three-dimensional CT volume and density histogram calculations suggest that it is especially effective on angiomyogenic components and fat-poor AMLs.

Transcatheter arterial embolization as therapy of renal angiomyolipomas: the evolution in 15 years of experience

OBJECTIVE

This study aims at presenting the evolution of the embolization technique in treating renal angiomyolipomas (AMLs) either diagnosed in patients with acute bleeding or discovered accidentally.

METHODS

Ten patients with renal AMLs have been through thirteen selective transcatheter arterial embolizations for 15 years. Two patients had tuberous sclerosis complex (TSC) with bilateral tumors and were embolized twice. Four embolic materials were employed: PVA particles, Gianturco coils, microspheres and microcoils. Catheterization was achieved by means of 5F Cobra 2 catheters and coaxial microcatheter systems.

RESULTS

On an emergency basis, embolization was a first-line treatment. In one case, surgery was necessary; in two patients, a second embolization was performed. When treatment was preventive, a single embolization proved to be sufficient, as well. There was no significant deterioration of the serum creatinine levels in the post-embolization period.

CONCLUSION

Selective arterial embolization is a rather safe and effective technique to treat AMLs both urgently and preventively. Different embolic materials can be employed. Microspheres and microcatheters stand for new promising materials.

Recognition of tuberous sclerosis in adult women: delayed presentation with life-threatening consequences

BACKGROUND

Tuberous sclerosis complex (TSC) is associated with tumor development in the brain, retina, kidney, skin, heart, and lung. Seizures, intellectual disability, and characteristic skin lesions commonly manifest in early childhood, but some findings, notably renal angiomyolipomas and pulmonary lymphangioleiomyomatosis (LAM), emerge later, placing adults with undiagnosed TSC at increased risk for morbidity and mortality.

OBJECTIVE

To describe the clinical presentation and severity of TSC in adult women.

DESIGN

Retrospective cohort study.

SETTING

National Institutes of Health Clinical Center, Bethesda, Maryland, 1995 to 2010.

PATIENTS

79 women aged 18 years or older who were enrolled in an observational cohort study of TSC to evaluate disease manifestations.

MEASUREMENTS

History, physical examination, pulmonary function testing, chest radiography, abdominal computed tomography, high-resolution chest computed tomography, and brain magnetic resonance imaging were used to evaluate patients.

RESULTS

Among the 45 patients who received a diagnosis of TSC in adulthood, 21 presented with symptoms due to LAM, 19 with renal angiomyolipomas, and 10 with seizures. Of the 45 patients, 30 met clinical criteria for TSC in childhood that remained undiagnosed for a median of 21.5 years and 15 were older than 18 years before meeting the clinical criteria for TSC. Patients diagnosed in adulthood and those diagnosed in childhood had similar occurrences of pneumothorax, shortness of breath, hemoptysis, nephrectomy, and death.

LIMITATION

No men were included in the study, and selection was biased toward patients having pulmonary LAM.

CONCLUSION

Women who received a TSC diagnosis in adulthood had minimal morbidity during childhood but were still at risk for life-threatening pulmonary and renal manifestations.

PRIMARY FUNDING SOURCE

Intramural Research Program, National Institutes of Health, National Heart, Lung, and Blood Institute.