Selective arterial embolization in the management of symptomatic renal angiomyolipomas

Renal AML Surgically Treated 33 Cases

BACKGROUND: Renal angiomyolipoma (RAML) is a rare benign neoplasm with a prevalence varying between 0.2% and 0.6% and a strong female predilection. They occur as sporadic, isolated entities in 80% of cases. The remaining 20% of angiomyolipomas (AMLs) develop in association with tuberous sclerosis complex or pulmonary lymphangioleiomyomatosis. AIM: We describe our 10-year experience with AML and discuss the treatment strategies employed at our center. METHODS: The medical records of all 33 patients with pathologically confirmed RAML treated either by nephrectomy or nephron-sparing surgery at our center over 10 years were reviewed for patient age and sex, tumor location and size, association with TBS. RESULTS: There were 28 females (84.8%) and 5 males (15.2%) with a median age that was 52 (range 22–74) years at the time of surgery. Thirty patients (90.9%) had sporadic isolated AML, and 3 patients (9.1%) had AML with TBS. The tumor was in the right kidney in 15 (45.5%) patients, in the left kidney in 17 (51.5%) patients, and bilateral in only 1 patient (3%) who was diagnosed with TBS. At presentation, flank pain was the main symptom in 23 patients (69.7%). CONCLUSIONS: Surgical resection of RAML provides short-term symptomatic relieve and long-term survival.

Updated International Tuberous Sclerosis Complex Diagnostic Criteria and Surveillance and Management Recommendations

BACKGROUND

Tuberous sclerosis complex (TSC) is an autosomal dominant genetic disease affecting multiple body systems with wide variability in presentation. In 2013, Pediatric Neurology published articles outlining updated diagnostic criteria and recommendations for surveillance and management of disease manifestations. Advances in knowledge and approvals of new therapies necessitated a revision of those criteria and recommendations.

METHODS

Chairs and working group cochairs from the 2012 International TSC Consensus Group were invited to meet face-to-face over two days at the 2018 World TSC Conference on July 25 and 26 in Dallas, TX, USA. Before the meeting, working group cochairs worked with group members via e-mail and telephone to (1) review TSC literature since the 2013 publication, (2) confirm or amend prior recommendations, and (3) provide new recommendations as required.

RESULTS

Only two changes were made to clinical diagnostic criteria reported in 2013: "multiple cortical tubers and/or radial migration lines" replaced the more general term "cortical dysplasias," and sclerotic bone lesions were reinstated as a minor criterion. Genetic diagnostic criteria were reaffirmed, including highlighting recent findings that some individuals with TSC are genetically mosaic for variants in TSC1 or TSC2. Changes to surveillance and management criteria largely reflected increased emphasis on early screening for electroencephalographic abnormalities, enhanced surveillance and management of TSC-associated neuropsychiatric disorders, and new medication approvals.

CONCLUSIONS

Updated TSC diagnostic criteria and surveillance and management recommendations presented here should provide an improved framework for optimal care of those living with TSC and their families.

TSC1 and TSC2: Tuberous Sclerosis Complex and Its Related Epilepsy Phenotype

Tuberous sclerosis complex (TSC) is an autosomal dominant disorder characterized by a multisystemic involvement. In TSC, reduced function of TSC1 and TSC2 genes products (hamartin and tuberin, respectively) leads to an hyperactivation of the mechanistic target of rapamycin (mTOR) pathway and to a consequent cell growth dysregulation. In TSC patients, neurological and neuropsychiatric manifestations, especially epilepsy and neuropsychiatric comorbidities such as autism or intellectual disability, represent the most disabling features. In particular, epilepsy occurrs up to 80% of patients, is often drug resistant and is frequently associated with neurological impairment. Due to the burden of this morbidity, different treatment strategies have been proposed with the purpose to make patients epilepsy free, such as the use of different antiepileptic drugs like vigabatrin, carbamazepine, valproic acid, and levetiracetam. More recently, a mTOR inhibitor (i.e. everolimus) has showed promising results in terms of seizures reduction.

Selective Arterial Embolization for Large or Symptomatic Renal Angiomyolipoma: 10 Years of Follow-up

OBJECTIVE

To assess long-term outcome after selective arterial embolization (SAE) as first-line treatment for large or symptomatic AML.

DESIGN, SETTING, AND PARTICIPANTS

Data from a prospectively maintained database on 71 patients who underwent SAE for large or symptomatic AML were reviewed. Patients with sporadic and tuberous-sclerosis-complex (TSC) were included.

OUTCOME MEASUREMENTS

The main endpoints were re-embolization rates, occurrence of clinical events related to AML, size of AML, and renal function.

RESULTS

Thirteen (19.1%) patients reported at least 1 major clinical event. Major complications affected 2 patients (2.9%), both ending in complete loss of renal unit function. Four renal units (5.9%) were eventually treated surgically. The re-embolization rate was 41.1%, with an average time from the initial to a repeat SAE of 2.18 years (range 0.31-10.65 years). The size of the tumor prior to SAE and after 5 and 10 years of follow-up were 8.9 cm (7-12), 6.5 cm (4-7.5), 7 cm (4-7.8), respectively [median (IQR)]. These results are translated to a size reduction of 27% in 10 years follow-up. Patients with TSC had larger tumors on long-term follow-up (77.8 vs 41.3 mm, P = .045). The long-term follow-up estimated average glomerular filtration rate was 81.97 (range 26-196). No patient needed renal replacement therapy, and disease-specific survival was 100%.

CONCLUSIONS

SAE is a safe treatment option for patients with symptomatic or large AML. It represents a minimally invasive intervention with good long-term outcome. SAE may be offered as first-line treatment in most cases, though, it is associated with high retreatment rates.

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.

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.

Long-term outcome of robotic partial nephrectomy for renal angiomyolipoma

BACKGROUND/OBJECTIVE

To present the long-term result and efficacy of robotic partial nephrectomy (RPN) for renal angiomyolipomas (AMLs) with perioperative outcome and renal function preservation.

METHODS

From September 2006 to October 2014, the database of a single medical center was reviewed and patients who underwent RPN for AMLs were enrolled. The patient demographics, perioperative complications, and postoperative outcomes were analyzed.

RESULTS

We identified 23 patients who were treated with RPN for renal AMLs. The average age was 52.7 (± 9.9) years, and 20 (87%) patients were female. The median size of the resected AML was 5.2 [interquartile range (IQR)=3.1-6.8] cm. The median estimated blood loss was 100 (IQR=50-225) mL, and three (13%) patients required blood transfusion. Perioperative complications occurred in six (26%) patients and none of them are higher than Clavien Grade II. The median estimated glomerular filtration rate at 3-month and the latest follow-ups were 103 (IQR=85.5-112) mL/min/1.73m² and 104 (IQR=90-112) mL/min/1.73m², respectively, with a median of 89.6% (IQR=84.2-100) and 86.9% (IQR=81.3-97.8) preservation, respectively. The median follow-up period was 40 (IQR=30.5-61.5) months. None of the patients developed complications requiring a second intervention or local recurrence of AML.

CONCLUSION

A long-term follow-up of RPN for renal AMLs revealed good preservation of renal function with a low complication rate. It may be considered as a reliable method to manage renal AMLs.

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.

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.

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.

Rates of interventional procedures in patients with tuberous sclerosis complex-related renal angiomyolipoma

OBJECTIVE

To describe rates of renal artery embolization, partial nephrectomy, and complete nephrectomy in patients with tuberous sclerosis complex (TSC) and renal angiomyolipoma.

METHODS

Data from the MarketScan® Research Databases were used to select patients with TSC and renal angiomyolipoma during January 1, 2000-March 31,2013 (Commercial database) and January 1, 2000-June 30, 2012 (Medicaid database). Patients had at least 30 days of follow-up and were followed until the earliest of inpatient death, end of enrollment, or end of study. Rates of embolization and nephrectomy were calculated.

RESULTS

In total, 218 patients <18 years (mean = 9.7 years) and 378 patients ≥18 years (mean 36.9 years) were selected from the Commercial database. Fifty-nine patients <18 years (mean = 7.2 years) and 117 patients ≥18 years (mean = 37.2 years) were selected from the Medicaid database. Follow-up in the Medicaid cohorts was approximately twice that of the Commercial cohorts. Among patients in the study, 24.2% had at least one interventional procedure: 15.2% had embolization, 5.2% had partial nephrectomy, and 7.6% had complete nephrectomy. Within the Commercial cohort ≥18 years, 18.5% had embolization, 7.7% had partial nephrectomy, and 11.4% had complete nephrectomy. Corresponding percentages in the Medicaid adult cohort were 17.1%, 5.1%, and 4.3%. Repeat embolization procedures occurred in up to 7.7% of Commercial patients and in up to 6.8% of Medicaid patients. Repeat partial nephrectomy occurred in up to 4.5% and 1.7% of Commercial and Medicaid patients, respectively.

CONCLUSIONS

Approximately 25% of patients with TSC-renal angiomyolipoma experienced embolization or nephrectomy, with some patients undergoing repeat procedures. Study limitations included small sample sizes, the majority of the study period occurred prior to the approval of mammalian target of rapamycin inhibitors for the treatment of TSC-renal AML, and results may not be generalizable to patients with insurance other than commercial or Medicaid.

Evaluation of split renal function before and after renal arterial embolization for angiomyolipoma using absolute ethanol

PURPOSE

Transcatheter arterial embolization (TAE) with absolute ethanol is widely accepted as a therapeutic procedure for renal angiomyolipoma (AML). We aim to evaluate the split renal function before and after AE for renal AML by using 99m-technetium (99mTc)-mercaptoacetyltriglycine 3 (MAG3) renography.

METHODS

This study was approved by the Institutional Review Board. The study population comprised 11 renal AML patients (three males, eight females, age 55.1 ± 13.8 years, AML in eight right and three left kidneys) who received unilateral renal TAE with absolute ethanol from April 2002 to January 2013. Blood renal function (i.e. serum creatinine and estimated glomerular filtration rate [eGFR] and split effective renal plasma flow [ERPF]) calculated on 99mTc-MAG3 renography was compared before and within 1 week after renal AE. Statistical analysis was calculated using Wilcoxon signed-ranked test.

RESULTS

TAE for renal AML was technically successful in all patients. Serum creatinine and eGFR did not change before and after TAE. ERPF on the embolized kidney did not change before (127.3 ± 60.8 ml/min) and after (127.6 ± 47.4 ml/min) TAE (p = 0.9726). ERPF on the nonembolized kidney showed a statistically significant increase before (152.5 ± 46.8 ml/min) and within 1 week after (169.1 ± 41.5 ml/min) TAE (p = 0.0093 and p < 0.05, respectively).

CONCLUSION

TAE for renal AML may not induce renal dysfunction on the embolized kidney and may immediately increase the renal blood flow of the nonembolized kidney.

Embolization of spontaneous intratumoral hemorrhage with the hemodynamic characteristics of arteriovenous fistula in renal angiomyolipoma

Aneurysms within renal angiomyolipomas (AML) may rupture into the tumor or pararenal space. Transcatheter arterial embolization is the first-choice treatment to control bleeding. Here, we describe the use of coil embolization in two cases of spontaneous intratumoral hemorrhage with the hemodynamic characteristics of renal arteriovenous (AV) fistula in renal AML. In case 1, renal angiography showed several intratumoral aneurysms, one of which had ruptured into the tumor, resulting in the formation of an intratumoral hematoma. Blood flow within the hematoma was rapid and the blood was immediately returned to the systemic circulation through the left renal vein. In case 2, renal angiography showed that the rupture of an intratumoral aneurysm of a tumor-feeding artery had resulted in formation of an intratumoral hematoma and direct renal vein communication. No extratumoral hemorrhage was observed in either case. The hemodynamics of both hematomas resembled those of a high-flow renal AV fistula. The ruptured aneurysms were embolized with detachable and pushable coils (case 1) or pushable coils only (case 2). To our knowledge, this is the first report of successful embolization of AV fistula-like intratumoral hemorrhage in renal AML.

Ultrasound-guided percutaneous microwave ablation of sporadic renal angiomyolipoma: preliminary results

BACKGROUND

Microwave ablation (MWA) has been developed as one of the most commonly used local oncologic treatments. However, there is still a dearth of studies concerning MWA in the treatment of renal angiomyolipomas (AML).

PURPOSE

To evaluate the efficacy and safety of ultrasound (US)-guided percutaneous MWA when treating AML.

MATERIAL AND METHODS

Nineteen lesions with pathologically confirmed AML in 14 patients (5 men, 9 women; mean age, 49.2 ± 14 years) were treated with US-guided percutaneous MWA with one or two cooled-shaft needle antennae. A power output of 45 W or 50 W for 300-1140 s was emitted to achieve complete tumor necrosis. Contrast-enhanced ultrasound (CEUS) was performed to observe the treatment efficacy 3 days later. Patients were followed up with CEUS, computed tomography (CT), and/or magnetic resonance imaging (MRI) after 1, 3, and 6 months, and long-term ablation efficacy was evaluated every 6 months thereafter.

RESULTS

Among the 19 renal lesions, 17 achieved complete ablation as monitored by US after one session of MWA, and two patients required a second session of MWA. Postoperative evaluation with CEUS showed that complete ablation was obtained in 15 lesions; however, in four lesions, complete ablation could not be attained. During the follow-up period of 6-36 months (median, 10 months), a fistula to the descending colon was found in one patient and local infection around the ablation zone was found in another. Neither injury to the renal pelvis nor damage to renal function was observed. None of the patients exhibited hematuria or abnormalities in routine urine tests during the hospitalization period or during follow-up. Minor complications, such as subcapsular bleeding, mild to moderate pain, and fever were eliminated after appropriate treatment.

CONCLUSION

MWA is an effective and minimally invasive technique for the management of AML that can preserve renal function with acceptable complication rates.

Tuberous sclerosis complex surveillance and management: recommendations of the 2012 International Tuberous Sclerosis Complex Consensus Conference

BACKGROUND

Tuberous sclerosis complex is a genetic disorder affecting every organ system, but disease manifestations vary significantly among affected individuals. The diverse and varied presentations and progression can be life-threatening with significant impact on cost and quality of life. Current surveillance and management practices are highly variable among region and country, reflective of the fact that last consensus recommendations occurred in 1998 and an updated, comprehensive standard is lacking that incorporates the latest scientific evidence and current best clinical practices.

METHODS

The 2012 International Tuberous Sclerosis Complex Consensus Group, comprising 79 specialists from 14 countries, was organized into 12 separate subcommittees, each led by a clinician with advanced expertise in tuberous sclerosis complex and the relevant medical subspecialty. Each subcommittee focused on a specific disease area with important clinical management implications and was charged with formulating key clinical questions to address within its focus area, reviewing relevant literature, evaluating the strength of data, and providing a recommendation accordingly.

RESULTS

The updated consensus recommendations for clinical surveillance and management in tuberous sclerosis complex are summarized here. The recommendations are relevant to the entire lifespan of the patient, from infancy to adulthood, including both individuals where the diagnosis is newly made as well as individuals where the diagnosis already is established.

CONCLUSIONS

The 2012 International Tuberous Sclerosis Complex Consensus Recommendations provide an evidence-based, standardized approach for optimal clinical care provided for individuals with tuberous sclerosis complex.

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.

[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.

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.

[Preventive and emergency embolization of angiomyolipomas: our experience]

AIM

To present our experience with emergency or programmed embolization of angiomyolipomas.

PATIENTS AND METHODS

The retrospective study 1999-2000 included a total of 20 patients with AML, five of whom had hypothyroidism. Group I emergency embolization: 11 patients age being 61.4 ± 15.6 years and the size of AML 8.2 ± 2.8 cm presented retroperitoneal hemorrhage from spontaneous rupture. Two had a hemorrhagic shock. A transfusion of 3.4 blood units per patient was performed for five patients. A clinical and radiological follow-up was done by scanning during the first week and in one month. Group II preventive embolization: nine patients, with age between 58.3 ± 15.2 years and tumor size 5.2 ± 2.2 cm, all asymptomatic. All successfully received a unilateral preventive embolization. A scan was performed one month later.

RESULTS

Group I: the embolization was effective in 100% of patients. No intraoperative incident was reported. After one month, the reduction in tumor volume was 40%. At eight months, a patient underwent nephrectomy because of a new fracture, and another a second embolization after 14 months. The technical result was maintained in 83% of cases after 18 months. Two patients developed HTA after embolization controlled by a single treatment, and five had limited renal ischemic sequels. Group II: no intraoperative incidents and no postoperatively complications have been reported. One month after embolization, the reduction in tumor volume was 23%. After 24 months, patients remained completely asymptomatic, no spontaneous bleeding has been reported, no surgery has been performed, and no HTA has been described. Only one re-embolization was done at 20 months (artery duplicity). Limited renal ischemic sequels were reported for one patient but no renal failure.

CONCLUSIONS

The required embolization became the method of choice in emergency with excellent results and few complications at distance. Programmed embolization effectively prevented the risk of bleeding, without impact on the renal function, with a low economic cost compared to hospitalization and emergency care. The significance of the observed AML--hypothyroidism association in our series requires a confrontation with more important cohorts.

Comparison of 3D two-point Dixon and standard 2D dual-echo breath-hold sequences for detection and quantification of fat content in renal angiomyolipoma

PURPOSE

To assess the utility of a 3D two-point Dixon sequence with water-fat decomposition for quantification of fat content of renal angiomyolipoma (AML).

METHODS

84 patients underwent renal MRI including 2D in-and-opposed-phase (IP and OP) sequence and 3D two-point Dixon sequence that generates four image sets [IP, OP, water-only (WO), and fat-only (FO)] within one breath-hold. Two radiologists reviewed 2D and 3D images during separate sessions to identify fat-containing renal masses measuring at least 1cm. For identified lesions subsequently confirmed to represent AML, ROIs were placed at matching locations on 2D and 3D images and used to calculate 2D and 3D SI(index) [(SI(IP)-SI(OP))/SI(IP)] and 3D fat fraction (FF) [SI(FO)/(SI(FO)+SI(WO))]. 2D and 3D SI(index) were compared with 3D FF using Pearson correlation coefficients.

RESULTS

41 AMLs were identified in 6 patients. While all were identified using the 3D sequence, 39 were identified using the 2D sequence, with the remaining 2 AMLs retrospectively visible on 2D images but measuring under 1cm. Among 32 AMLs with a 3D FF of over 50%, both 2D and 3D SI(index) showed a statistically significant inverse correlation with 3D FF (2D SI(index): r=-0.63, p=0.0010; 3D SI(index): r=-0.97, p<0.0001).

CONCLUSION

3D two-point Dixon sequence may provide a reasonable alternative to 2D dual-echo sequence for detection of renal AML and may have additional value for quantification of fat content of these lesions given the observation that 3D FF, unlike 2D and 3D SI(index), is not limited by ambiguity of water or fat dominance. This may assist clinical management of AML given evidence that fat content predicts embolization response.

Endovascular therapy for patients with renal angiomyolipoma presenting with retroperitoneal haemorrhage

We report our experience treating four patients with acutely bleeding angiomyolipoma (AML) of sizes between 4 and 12 cm who were managed with endovascular embolisation with a mean follow-up of 10 months. In our case series, we demonstrate that endovascular embolisation in the acute setting for bleeding AMLs is a viable treatment option. AML should be in the differential diagnosis of acutely bleeding renal masses, even when there is no fat assessed by computed tomography (CT) imaging in the renal mass.

The radiological diagnosis and treatment of renal angiomyolipoma-current status

Angiomyolipomas (AMLs) are the most common benign renal neoplasm and are often discovered incidentally. Due to both an increase in the use of imaging, as well as advances in imaging technology, they are being increasing identified in the general population. As these lesions are benign, there is good evidence that the majority of them can be safely followed up without treatment. However, there is an increasing wealth of information available suggesting there are individuals with AMLs where prophylactic treatment is indicated to prevent complications such as haemorrhage. In such cases, treatment with radiological interventional techniques with subselective particle embolization has superseded surgical techniques in most cases. Even in emergency cases with catastrophic rupture, prompt embolization may save the patient with the additional benefit of renal salvage. Confident identification of a lesion as an AML is important as its benign nature obviates the need for surgery in most cases. The presence of fat is paramount in the confirmatory identification and characterization of these lesions. Although fat-rich AMLs are easy to diagnose, some lesions are fat poor and it is these cases where newer imaging techniques, such as in-phase and out-of-phase magnetic resonance imaging (MRI) may aid in making a confident diagnosis of AML. In this paper, we comprehensively review the imaging techniques in making a diagnosis of AML, including features of both characteristic lesions as well as atypical lesions. In addition, we discuss current guidelines for follow-up and prophylactic treatment of these lesions, as well as the increasing role that the interventional radiologist has to play in these cases.

Long-term follow-up of the treatment of renal angiomyolipomas after selective arterial embolization with alcohol

STUDY TYPE

Therapy (case series).

LEVEL OF EVIDENCE

4.

OBJECTIVE

To present our institution's experience of selective embolization of renal angiomyolipomas with alcohol and the long-term follow up data.

PATIENTS AND METHODS

This retrospective study included 34 patients treated between October 1997 and October 2007 (29 women and five men, mean age 44 years). Of these patients, nine had tuberous sclerosis, 14 were bilateral and 16 were multifocal. Indications for treatment were previous haemorrhage (14), size >4 cm (19) and increasing size over a short period (one). The largest treated lesion was 24.4 cm, and the mean (range) size was 11.9 (2.9-24.4) cm. All patients were treated by selective embolization using a mixture of alcohol and lipiodol. Three patients also had coiling of aneurysms and two patients had additional embolization with polyvinyl alcohol particles. The follow-up was both radiological and clinical, with recurrence defined as growth by >2 cm or symptoms requiring further treatment.

RESULTS

The technical success rate was 100%, with only one significant complication of non-target renal embolization, with self-limiting effects. Minor complications included 11 patients with post-embolization syndrome, all of which settled with conservative measures. The mean (range) combined radiological and clinical follow-up was 44.2 (12-116) months, with all patients having a follow-up of >1 year. Radiological success was achieved in 97%, with only one lesion growing by >2 cm. The combined clinical and radiological success rate was 85%, with two patients undergoing surgery, two having repeat embolization and one currently offered surgery due to a recent increase in size.

CONCLUSION

Our study provides long-term evidence that selective arterial embolization with alcohol is a safe and effective method for improving clinical symptoms (85%) and preventing tumour progression (97%) in patients with renal angiomyolipoma.

Onyx embolization of sporadic angiomyolipoma

Percutaneous embolization is the currently preferred treatment of symptomatic or ruptured renal angiomyolipomas (AMLs). Alcohol, microparticles, and coils are usually used. We present what is to our knowledge the first case of successful embolization of a solitary sporadic AML with the use of a new nonadhesive liquid embolic agent (ethylene vinyl alcohol copolymer; Onyx). Onyx injection was slow and controllable and achieved complete tumor devascularization, producing a characteristic appearance like a vascular cast. Short-term follow-up magnetic resonance imaging showed complete tumor necrosis without any recurrent pathologic vessels. The specific features, potential advantages in AML treatment, and technical limitations of this new liquid embolic agent are discussed.

[Renal angiomyolipoma: presentation, treatment and results of 20 cases]

INTRODUCTION

Renal angiomyolipoma is a benign tumour, but its spontaneous rupture may become threatening for patient's live. Both surgery and selective arterial embolization are accepted treatments for this lesion.

OBJECTIVES

Analyze renal angyolipoma treated in our center, their clinical outcome and treatment purposed in each case.

MATERIAL AND METHODS

We retrospectively analyse 20 cases of patients with renal angiomyolipoma treated in our centre from March 1996 to March 2006. We describe tumour characteristics, treatment followed and results obtained.

RESULTS

Patients suffering from tuberous sclerosis (20%) showed multiple bilateral tumours, with size similar to the rest of patients. Diagnosis of tuberous sclerosis was the only factor attached to spontaneous rupture of those lesions. Four of 9 emergency embolized patients (44.4%) required from second treatment because of recurrent haemorrhage, and 4 of the 16 embolization episodes (25%) presented post-embolization syndrome, both with no predicting factors attached. Reduction of less than one third of the inicial diameter was observed in 58.4% of embolized tumours, which used to be multiple, bilateral and of size larger to the rest. No significative differences were observed in plasmatic creatinine after and before treatments.

CONCLUSIONS

Renal angiomyolipoma may behave in an aggressive way in patients with tuberous sclerosis. No predicting factors of recurrent haemorrhage or post-embolization syndrome were observed. Both surgery and arterial embolization have proved not to compromise renal function in treated patients.

Spontaneous hemorrhagic angiomyolipoma present with massive hematuria leading to urgent nephrectomy

Managing acute abdomen is a challenge for physicians in the emergency department. An immediate surgery is sometimes required for the hemorrhagic uropathy of renal angiomyolipoma. We present a case with left flank pain and findings of hematuria and pyuria. Abdominal and pelvic computed tomographic scans showed a 3 x 5-cm, fat-containing tumor at the left lower pole of the kidney and a bleeding and perirenal hematoma in the left perirenal space. An urgent left nephrectomy was lifesaving for the postoperative finding of renal angiomyolipoma. It is important to consider the possibility of the presence of such a tumor when spontaneous retroperitoneal hemorrhage and hypovolemic shock are encountered.

[Role of embolization in renal angiomyolipomas]

OBJECTIVE

The purpose of this study is to present the role of embolization in the treatment of renal angiomyolipoma (AML) in cases of hemorrhage and to prevent bleeding.

METHODS

Over a period of 10 years, 35 AMLs in 34 patients, recruited in two medical centers, were treated with embolization: 16/35 AML were treated urgently to stop bleeding, and 19/35 AML had preventive embolization. Six patients were completely asymptomatic and 13 had a history of previous hematoma or flank pain. Catheterization was highly selective in all cases (coaxial microcatheter in 19 cases), and for embolization we used nonresorbable microparticles, coils, and alcohol.

RESULTS

When patients presented with acute bleeding, embolization was efficient in 80% of cases; another embolization was necessary in two cases, and surgery in two others. In six of these cases, surgery was planned and done at a later date. When treatment was preventive, one embolization was necessary in 17 cases, and two embolizations per case were necessary in the other two. Over a period of 18 months of follow-up, we observed a 28% decrease in tumor volume; four patients were treated by surgery at a later date.

CONCLUSION

Embolization is the technique of choice to treat a bleeding AML urgently. When preventive treatment is considered, in symptomatic or asymptomatic AML, embolization can be an alternative for surgery, but more data is needed to specify its proper place in the management of these tumors.

Management of renal abscess formation after embolization due to renal angiomyolipomas in two cases

Current management strategies of renal angiomyolipomas (AMLs) include observation, embolization and partial or total nephrectomy. Selective arterial embolization is an effective and safe treatment of large angiomyolipomas with low complication rates. Percutaneous drainage was the recommended treatment for renal abscess formation following the embolization. Herein we describe two cases which we performed percutaneous drainage of the liquefaction of entire tumors after embolization. Open surgery was needed for one of the patients who showed recurrence after percutaneous drainage and alcohol irrigation of the cavity, whereas percutaneous drainage was the sufficient treatment for the other patient as recommended.

Sonography in Benign and Malignant Renal Masses

Ultrasonography and CT have allowed improved detection of renal mass lesions. Though ultrasonography is less sensitive in the characterization of the renal mass lesions, it is often the first imaging modality for evacuation of the kidneys. This article gives an overview of the benign and malignant renal mass lesions and the role of ultrasonography in their characterization.

Ethanol and polyvinyl alcohol mixture for transcatheter embolization of renal angiomyolipoma

OBJECTIVE

The purpose of this study was to assess the immediate and midterm effects of embolization of the angiogenic component of renal angiomyolipoma in which a mixture of ethanol and polyvinyl alcohol is used as a permanent obliterator.

MATERIALS AND METHODS

Seventeen patients with 18 renal angiomyolipomas (size range, 5.5-20 cm; mean size, 10 cm) were treated with transcatheter embolization over an 8-year period. Embolization was performed with a mixture of 96% ethanol and polyvinyl alcohol particles. Follow-up with CT (mean follow-up period, 22.4 months) and one (mean, 14 months) or two (mean, 27 months) angiographic examinations were conducted to evaluate changes in the size of the tumor and to look for recurrence of the angiogenic component.

RESULTS

All initial angiograms showed the characteristic tortuous, hypervascular, and aneurysm-forming angiogenic component. Immediate complete obliteration was achieved in 17 tumors (94.4% technical success rate). There was one partial technical failure. Mean tumor size was reduced to 7.6 cm (mean size reduction, 24%). Fourteen patients with 15 tumors underwent one angiographic follow-up examination (mean time after treatment, 14 months), and four patients underwent two angiographic follow-up examinations (mean time after treatment, 27 months). Reduction of the angiogenic component occurred in 10 (66.6%) of the tumors and complete obliteration in five (33.3%) of the tumors. No retroperitoneal hemorrhage or tumor growth was seen during the follow-up period. No complications were encountered.

CONCLUSION

We found a mixture of ethanol and polyvinyl alcohol an efficient embolizing agent with a sustained midterm effect in the management of renal angiomyolipoma. Repeated embolization was needed in tumors with a large angiogenic component. Tumor shrinkage after embolization was minimal.

Large renal angiomyolipomas: digital subtraction angiographic grading and presentation with bleeding

AIM

To investigate whether a grading system of renal AMLs based on digital subtraction angiography (DSA) and computerized tomography (CT), could help to select patients for embolization.

MATERIALS AND METHODS

Thirty patients with 35 renal angiomyolipomas (size range 4-20 cm, mean 9.9 cm) underwent both digital subtraction angiography (DSA) and computed tomography (CT). Based on the DSA appearance the tumours were graded into three grades: grade I, minimal vascularity; grade II, moderate vascularity; grade III, marked vascularity.

RESULTS

There were seven grade I (mean 9.3 cm, range 4.5-20 cm), 18 grade II (mean 8.9 cm, range 5-18 cm) and 10 grade III tumours (mean 12.1 cm, range 4-20 cm). Five grade I tumours did not cause symptoms (71%) and two caused flank pain and haematuria, respectively (14.3% each). Nine of the grade II tumours were asymptomatic (50%), seven caused bleeding (39%) and two caused flank pain (11%). Four grade III tumours were asymptomatic (40%), five caused bleeding (50%) and one pain (10%).

CONCLUSIONS

According to our criteria, large angiomyolipomas with minimal vascularity are less likely to bleed, and do not need prophylactic treatment. This needs to be confirmed in larger studies.

[Renal angiomyolipomatosis and pulmonary lymphangiomyomatosis. Its relationship with Bourneville syndrome]

INTRODUCTION

Renal angiomyolipomas are not very frequent in urologic activities. Pulmonary lymphangioleiomyomatosis is a rare disease that occurs mainly in women of reproductive age. Tuberous sclerosis shows lesions to different organs, including these both entities.

MATERIAL AND METHOD

We retrospectively analyze patients treated in our center. Three most representatives cases are reported. An indexed literature review is done, in order to establish a clinical protocol to manage these kinds of patients.

RESULTS

[corrected] Between 1990 and 2004, eight patients have been attended with an angiomyolipoma renal diagnostic. Five women (62%) and three men (38%). Medium age is 52,3y (29-69). In 3 of them (all women), it was also done a diagnostic of pulmonary lymphangioleiomyomatosis.

CONCLUSIONS

Bourneville syndrome is not very frequent. Associated angiomyolipomas usually are multiple, bilateral, with tender to grow and require more interventions. Previous diagnostic let us prevent future complications with vigilance, selective arterial embolization and nephron-spare surgery. Tumour size and the presence of symptoms are more decisive to decide best therapy alternative. Young patients with pulmonary lymphangioleiomyomatosis should be advise against pregnancy and the use of preparations containing estrogens.

Huge renal angiomyolipomas in tuberous sclerosis complex

Tuberous sclerosis complex (TSC) is an autosomal dominance disorder with variable penetrance. Renal angiomyolipoma (AML) is one of the commonest urological manifestations. These lesions may cause significant morbidity and mortality. We report two patients with multiple and huge renal angiomyolipomas presenting with gross haematuria. They subsequently underwent unilateral nephrectomy. The difficulty in diagnosis and controversies in management will be briefly discussed.

Radiofrequency ablation for tumor-related massive hematuria

To determine whether radiofrequency (RF) ablation targeting the tumor-collecting system interface has a durable effect in patients with transfusion-dependent kidney tumor-related hematuria, four patients aged 61-71 years were successfully treated with RF ablation, with a mean follow up of 12 months. Baseline creatinine levels varied from 2.0 mg/dL to 3.7 mg/dL. All patients had received red blood cell transfusions in the days and hours before RF ablation. No subsequent surgical or interventional procedures were required for management of hematuria. Gross hematuria resolved in 24-48 hours in all four patients. Two of the patients are alive with stable renal function and two died of causes unrelated to treatment. RF ablation may be an effective therapeutic option for transfusion-dependent cancer-related hematuria in patients with renal insufficiency, solitary kidney, or comorbidities, or after failed conventional therapies in patients who are not candidates for surgery.

Embolization of a bleeding renal angiomyolipoma in pregnancy: case report and review

A case is described of a woman 10 weeks pregnant who had severe bleeding, secondary to a renal angiomyolipoma (AML), that was treated with embolization. Subsequent pregnancy was uneventful and she delivered a normal female infant 28 weeks after the procedure. One month after delivery, liquefaction of the AML occurred, which eventually required surgical drainage. We review and discuss AML during pregnancy, its management and post-embolization complications.