Cardiovasc Intervent Radiol DOI 10.1007/s00270-014-0887-0
CASE REPORT
Renoduodenal Fistula After Transcatheter Embolization of Renal Angiomyolipoma Rahul A. Sheth • Adam S. Feldman T. Gregory Walker
•
Received: 5 February 2014 / Accepted: 21 February 2014 Ó Springer Science+Business Media New York and the Cardiovascular and Interventional Radiological Society of Europe (CIRSE) 2014
Keywords Angiomyolipoma Complication Embolization
minimally invasive procedure that has been successfully used to prophylactically reduce bleeding risk from AMLs in the elective setting and to acutely control hemorrhage in the emergent setting. Embolization is an established, safe, and effective method for managing AMLs, with long-term studies revealing a low incidence of acute and chronic complications [1–5]. Fistula formation between visceral organs and the alimentary tract is a rare complication of transcatheter embolization. Previously published case reports have described bronchoesophageal fistulas after bronchial artery embolization [6] as well as renocolonic [7] and renoduodenal [8] fistulae after radiofrequency ablation and cryoablation of renal masses. In this report, we describe the formation of a renoduodenal fistula after embolization of a renal AML.
Introduction
Case Report
Renal angiomyolipomas (AMLs) are soft tissue hamartomatous tumors composed of various stromal elements that include fat, smooth muscle, and blood vessels. Although these tumors are benign, they can undergo spontaneous hemorrhage, a potentially life-threatening event [1]. Transcatheter arterial embolization is a
Institutional review board approval was obtained for the conduct of this case report. A 34-year-old woman with a medical history of tuberous sclerosis complex had been followed closely since childhood with annual magnetic resonance imaging examinations for follow-up of known bilateral renal AMLs. At baseline, the patient was in good health, living independently, and working full-time. One day before the patient’s referral to our service, she developed acute right lower back pain. A noncontrast computed tomography (CT) scan at another hospital revealed a hemorrhagic right AML measuring 11 9 9 cm. Given these imaging findings, the patient was transferred to our hospital for further management. At presentation, the patient was normotensive, with physical examination findings notable only for mild right
Abstract 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.
R. A. Sheth T. G. Walker (&) Division of Interventional Radiology, Department of Radiology, Massachusetts General Hospital, 55 Fruit St, Boston, MA 02114, USA e-mail: [email protected] A. S. Feldman Division of Urology, Department of Surgery, Massachusetts General Hospital, 55 Fruit St, Boston, MA 02114, USA
123
R. A. Sheth et al.: Renoduodenal Fistula After AML Embolization
Fig. 1 Procedural imaging from angiomyolipoma embolization. A Angiogram of right kidney demonstrates large exophytic angiomyolipoma (arrows indicate outer boundary of mass). Arteries
costovertebral angle tenderness. She was slightly anemic, with a hematocrit of 30.5 % and a hemoglobin of 10.8 g/dL, compared to baselines of 40.5 % and 13.8 g/dL, respectively. Given the patient’s imaging findings of perinephric and retroperitoneal hematoma, the decision was made to perform transcatheter embolization of the hemorrhagic AML. This was performed with the patient under conscious sedation. Initial aortography revealed single bilateral renal arteries. The right renal artery was selected by a Cobra 1 catheter (Angiodynamics, Latham, NY), and digital subtraction angiography (DSA) revealed a large hypervascular mass arising from the lateral margin of the right kidney (Fig. 1A), which corresponded to the patient’s known hemorrhagic AML. The DSA was also notable for multiple pseudoaneurysms involving several of the feeding arteries supplying the tumor. A microcatheter (Progreat; Terumo, Somerset, NJ) was passed coaxially through the main catheter and into the lesion. Transcatheter embolization of multiple arteries feeding the AML was performed using a combination of 300–500 lm microspheres and Gelfoam pledgets; a single VortX 2 9 3 mm coil (Boston Scientific, Natick, MA) was used as well. Postembolization DSA showed stasis of contrast flow within the arteries supplying the tumor, a finding that was interpreted as a successful embolization (Fig. 1B). The patient’s immediate postprocedure recovery was essentially unremarkable. She developed a low-grade fever 24 h after the embolization procedure. This was managed conservatively as a manifestation of postembolization syndrome. Serial hematocrit evaluations during her hospitalization
123
feeding lesion demonstrate multiple aneurysms. B Postembolization digital subtraction angiography reveals stasis of contrast flow within arteries supplying tumor
Fig. 2 Follow-up CT scan of abdomen in coronal reconstruction performed 6 months after embolization demonstrates hypoattenuation within treated angiomyolipoma, which was interpreted as suggestive of treatment response. However, foci of gas within lesion raised suspicion of infection
were stable, and she was discharged home on postprocedure day 2. After discharge, the patient was followed closely in both the urology and nephrology clinics. Over the next several months, the patient experienced repeated episodes of lightheadedness and generalized fatigue. A complete blood count performed 6 months after the procedure revealed hemoglobin of 7.6 g/dL and hematocrit of 22.7 %. A CT
R. A. Sheth et al.: Renoduodenal Fistula After AML Embolization
Fig. 3 A CT scan demonstrating nasogastric tube coursing from proximal duodenum directly into right renal angiomyolipoma, consistent with renoduodenal fistula. B Contrast injection through percutaneous drainage catheter terminating within infected angiomyolipoma directly opacifies fistula between right kidney and duodenum
scan performed at this time revealed an interval decrease in the size of the embolized AML, but it also revealed foci of gas within the AML (Fig. 2), which raised the possibility of infection. However, she demonstrated no signs of clinical infection, and no new source of hemorrhage was identified that would have explained the patient’s anemia. Although there was no definite cause for the patient’s anemia, she was treated with intravenous iron infusions and erythropoietin injections, with some improvement over the
ensuing 4 months. However, at 10 months after the procedure, the patient presented to the emergency department with fevers and a nonwitnessed seizure. She had been found in the bathroom by her family early in the morning and was initially noted to be nonresponsive and to have left-sided hemiplegia. After approximately 5 min, she gradually recovered mobility of her left side and became appropriately responsive. The patient had been experiencing low-grade temperatures to 38.3 °C during the week before her seizure. During her emergency department evaluation, a magnetic resonance imaging of the brain was performed, which revealed a 4.8 cm right temporal lobe abscess as well as a small 4 mm right subdural empyema. The complete blood count was notable for a white blood cell count of 20,600 cells/mm3, hemoglobin of 7.6 g/dL, and hematocrit of 24.9 %. She underwent emergency evacuation of the intracranial empyema and abscess. A repeat abdominal CT scan after the surgery showed multiple gas- and fluid-filled abscesses within the right kidney. The CT was also notable for extension of a nasogastric tube through the duodenal wall and into the right renal abscesses. This finding raised the suspicion for a renoduodenal fistula. Five separate drainage catheters were placed percutaneously into these renal abscess collections. Subsequent contrast injection through the drainage catheters immediately opacified the duodenum, thereby demonstrating a fistulous communication between the right renal collecting system and the bowel (Fig. 3). This finding of a renoduodenal fistula was thought to be the likely source of the patient’s intracranial abscess. Transesophageal echocardiography revealed the presence of a patent foramen ovale, thus confirming a mechanism for paradoxical septic embolization. The patient’s chronic anemia was also suspected to be related to the fistula: chronic inflammation of the duodenal mucosa as a result of the fistula likely resulted in a low-grade, chronic gastrointestinal bleed, though endoscopy was not performed to confirm this hypothesis. The patient was discharged with a prolonged course of antibiotics with drains in place, with the expectation that the fistula would close via this conservative approach. Her mental status recovered to baseline, and her fevers abated. The drains were subsequently removed in an outpatient setting, and she was followed closely for the next 24 months with serial imaging to evaluate her for any evidence of recurrence of the renal abscesses. On serial imaging, there were unresolving foci of gas within the treated right renal AML, and thus the decision was made to perform a partial versus total nephrectomy for definitive treatment of what was thought to most likely represent a persistent renoduodenal fistula. Surgery was performed 39 months after the initial embolization procedure. Intraoperatively, the fistulous connection was visualized, and an
123
R. A. Sheth et al.: Renoduodenal Fistula After AML Embolization
approximately 8 mm defect in the duodenum was primarily repaired. The necrotic portion of the upper pole of the kidney was debrided, but the mid and lower pole of the kidney were preserved. Two years after surgery, the patient continued to do well, with resolution of her anemia and return to baseline level of function.
renal abscesses that the diagnosis was made. In retrospect, the only suggestive evidence that could have allowed an earlier diagnosis was the persistence of gas within the treated AML. Although there are numerous potential causes for this finding, it is important to consider fistula formation to the alimentary tract, particularly in a patient with otherwise unexplainable symptoms such as chronic anemia, weight loss, or low-grade fevers.
Discussion Transcatheter embolization of renal AMLs 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 [9]. However, fistula formation between visceral organs and the alimentary tract is a rare complication of transcatheter embolization. Case reports have described bronchoesophageal fistulas occurring after bronchial artery embolization for massive hemoptysis [6]. Similarly, renocolonic [7] and renoduodenal [8] fistulae have been reported after radiofrequency ablation and cryoablation of renal masses. The mechanism by which this major complication arose in the case presented in this report is uncertain but may be attributable to the inflammatory changes that arise in response to the ischemia induced by embolization resulting in erosion into the duodenal lumen. Interestingly, Yoon et al. [10] describe a renocolonic fistula that arose after embolization of a renal arteriovenous malformation using guide wires. The putative mechanism for this patient’s complication was erosion by the guide wires into the adjacent colon; however, because the patient in our report received only a single 3 mm coil during her embolization procedure, this seems an unlikely explanation for her fistula formation. Another remarkable aspect of this patient’s case is the length of time that passed before the complication was recognized. The patient was treated for persistent anemia of unknown cause for almost a year after embolization, and it was not until the development of fulminant brain and
123
Conflict of interest Dr. Feldman has served as a consultant for Novartis Pharmaceuticals for the medical treatment of spontaneous angiomyolipomas. Rahul A. Sheth declares no conflict of interest. T. Gregory Walker declares no conflict of interest.
References 1. Rimon U, Duvdevani M, Garniek A et al (2006) Large renal angiomyolipomas: digital subtraction angiographic grading and presentation with bleeding. Clin Radiol 61:520–526 2. Steiner MS, Goldman SM, Fishman EK, Marshall FF (1993) The natural history of renal angiomyolipoma. J Urol 150:1782–1786 3. Kothary N, Soulen MC, Clark TWI et al (2005) Renal angiomyolipoma: long-term results after arterial embolization. J Vasc Interv Radiol 16:45–50 4. Chatziioannou A, Gargas D, Malagari K et al (2012) Transcatheter arterial embolization as therapy of renal angiomyolipomas: the evolution in 15 years of experience. Eur J Radiol 81: 2308–2312 5. Ewalt DH, Diamond N, Rees C et al (2005) Long-term outcome of transcatheter embolization of renal angiomyolipomas due to tuberous sclerosis complex. J Urol 174:1764–1766 6. Munk PL, Morris DC, Nelems B (1990) Left main bronchialesophageal fistula: a complication of bronchial artery embolization. Cardiovasc Intervent Radiol 13:95–97 7. Vanderbrink BA, Rastinehad A, Caplin D et al (2007) Successful conservative management of colorenal fistula after percutaneous cryoablation of renal-cell carcinoma. J Endourol 21:726–729 8. de Arruda HO, Goldman S, Andreoni C et al (2006) Renoduodenal fistula after renal tumor ablation with radiofrequency. Surg Laparosc Endosc Percutan Tech 16:342–343 9. Lee SY, Hsu HH, Chen YC et al (2009) Embolization of renal angiomyolipomas: short-term and long-term outcomes, complications, and tumor shrinkage. Cardiovasc Intervent Radiol 32:1171–1178 10. Yoon JW, Koo JR, Baik GH et al (2004) Erosion of embolization coils and guidewires from the kidney to the colon: delayed complication from coil and guidewire occlusion of renal arteriovenous malformation. Am J Kidney Dis 43:1109–1112
CASE REPORT
Renoduodenal Fistula After Transcatheter Embolization of Renal Angiomyolipoma Rahul A. Sheth • Adam S. Feldman T. Gregory Walker
•
Received: 5 February 2014 / Accepted: 21 February 2014 Ó Springer Science+Business Media New York and the Cardiovascular and Interventional Radiological Society of Europe (CIRSE) 2014
Keywords Angiomyolipoma Complication Embolization
minimally invasive procedure that has been successfully used to prophylactically reduce bleeding risk from AMLs in the elective setting and to acutely control hemorrhage in the emergent setting. Embolization is an established, safe, and effective method for managing AMLs, with long-term studies revealing a low incidence of acute and chronic complications [1–5]. Fistula formation between visceral organs and the alimentary tract is a rare complication of transcatheter embolization. Previously published case reports have described bronchoesophageal fistulas after bronchial artery embolization [6] as well as renocolonic [7] and renoduodenal [8] fistulae after radiofrequency ablation and cryoablation of renal masses. In this report, we describe the formation of a renoduodenal fistula after embolization of a renal AML.
Introduction
Case Report
Renal angiomyolipomas (AMLs) are soft tissue hamartomatous tumors composed of various stromal elements that include fat, smooth muscle, and blood vessels. Although these tumors are benign, they can undergo spontaneous hemorrhage, a potentially life-threatening event [1]. Transcatheter arterial embolization is a
Institutional review board approval was obtained for the conduct of this case report. A 34-year-old woman with a medical history of tuberous sclerosis complex had been followed closely since childhood with annual magnetic resonance imaging examinations for follow-up of known bilateral renal AMLs. At baseline, the patient was in good health, living independently, and working full-time. One day before the patient’s referral to our service, she developed acute right lower back pain. A noncontrast computed tomography (CT) scan at another hospital revealed a hemorrhagic right AML measuring 11 9 9 cm. Given these imaging findings, the patient was transferred to our hospital for further management. At presentation, the patient was normotensive, with physical examination findings notable only for mild right
Abstract 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.
R. A. Sheth T. G. Walker (&) Division of Interventional Radiology, Department of Radiology, Massachusetts General Hospital, 55 Fruit St, Boston, MA 02114, USA e-mail: [email protected] A. S. Feldman Division of Urology, Department of Surgery, Massachusetts General Hospital, 55 Fruit St, Boston, MA 02114, USA
123
R. A. Sheth et al.: Renoduodenal Fistula After AML Embolization
Fig. 1 Procedural imaging from angiomyolipoma embolization. A Angiogram of right kidney demonstrates large exophytic angiomyolipoma (arrows indicate outer boundary of mass). Arteries
costovertebral angle tenderness. She was slightly anemic, with a hematocrit of 30.5 % and a hemoglobin of 10.8 g/dL, compared to baselines of 40.5 % and 13.8 g/dL, respectively. Given the patient’s imaging findings of perinephric and retroperitoneal hematoma, the decision was made to perform transcatheter embolization of the hemorrhagic AML. This was performed with the patient under conscious sedation. Initial aortography revealed single bilateral renal arteries. The right renal artery was selected by a Cobra 1 catheter (Angiodynamics, Latham, NY), and digital subtraction angiography (DSA) revealed a large hypervascular mass arising from the lateral margin of the right kidney (Fig. 1A), which corresponded to the patient’s known hemorrhagic AML. The DSA was also notable for multiple pseudoaneurysms involving several of the feeding arteries supplying the tumor. A microcatheter (Progreat; Terumo, Somerset, NJ) was passed coaxially through the main catheter and into the lesion. Transcatheter embolization of multiple arteries feeding the AML was performed using a combination of 300–500 lm microspheres and Gelfoam pledgets; a single VortX 2 9 3 mm coil (Boston Scientific, Natick, MA) was used as well. Postembolization DSA showed stasis of contrast flow within the arteries supplying the tumor, a finding that was interpreted as a successful embolization (Fig. 1B). The patient’s immediate postprocedure recovery was essentially unremarkable. She developed a low-grade fever 24 h after the embolization procedure. This was managed conservatively as a manifestation of postembolization syndrome. Serial hematocrit evaluations during her hospitalization
123
feeding lesion demonstrate multiple aneurysms. B Postembolization digital subtraction angiography reveals stasis of contrast flow within arteries supplying tumor
Fig. 2 Follow-up CT scan of abdomen in coronal reconstruction performed 6 months after embolization demonstrates hypoattenuation within treated angiomyolipoma, which was interpreted as suggestive of treatment response. However, foci of gas within lesion raised suspicion of infection
were stable, and she was discharged home on postprocedure day 2. After discharge, the patient was followed closely in both the urology and nephrology clinics. Over the next several months, the patient experienced repeated episodes of lightheadedness and generalized fatigue. A complete blood count performed 6 months after the procedure revealed hemoglobin of 7.6 g/dL and hematocrit of 22.7 %. A CT
R. A. Sheth et al.: Renoduodenal Fistula After AML Embolization
Fig. 3 A CT scan demonstrating nasogastric tube coursing from proximal duodenum directly into right renal angiomyolipoma, consistent with renoduodenal fistula. B Contrast injection through percutaneous drainage catheter terminating within infected angiomyolipoma directly opacifies fistula between right kidney and duodenum
scan performed at this time revealed an interval decrease in the size of the embolized AML, but it also revealed foci of gas within the AML (Fig. 2), which raised the possibility of infection. However, she demonstrated no signs of clinical infection, and no new source of hemorrhage was identified that would have explained the patient’s anemia. Although there was no definite cause for the patient’s anemia, she was treated with intravenous iron infusions and erythropoietin injections, with some improvement over the
ensuing 4 months. However, at 10 months after the procedure, the patient presented to the emergency department with fevers and a nonwitnessed seizure. She had been found in the bathroom by her family early in the morning and was initially noted to be nonresponsive and to have left-sided hemiplegia. After approximately 5 min, she gradually recovered mobility of her left side and became appropriately responsive. The patient had been experiencing low-grade temperatures to 38.3 °C during the week before her seizure. During her emergency department evaluation, a magnetic resonance imaging of the brain was performed, which revealed a 4.8 cm right temporal lobe abscess as well as a small 4 mm right subdural empyema. The complete blood count was notable for a white blood cell count of 20,600 cells/mm3, hemoglobin of 7.6 g/dL, and hematocrit of 24.9 %. She underwent emergency evacuation of the intracranial empyema and abscess. A repeat abdominal CT scan after the surgery showed multiple gas- and fluid-filled abscesses within the right kidney. The CT was also notable for extension of a nasogastric tube through the duodenal wall and into the right renal abscesses. This finding raised the suspicion for a renoduodenal fistula. Five separate drainage catheters were placed percutaneously into these renal abscess collections. Subsequent contrast injection through the drainage catheters immediately opacified the duodenum, thereby demonstrating a fistulous communication between the right renal collecting system and the bowel (Fig. 3). This finding of a renoduodenal fistula was thought to be the likely source of the patient’s intracranial abscess. Transesophageal echocardiography revealed the presence of a patent foramen ovale, thus confirming a mechanism for paradoxical septic embolization. The patient’s chronic anemia was also suspected to be related to the fistula: chronic inflammation of the duodenal mucosa as a result of the fistula likely resulted in a low-grade, chronic gastrointestinal bleed, though endoscopy was not performed to confirm this hypothesis. The patient was discharged with a prolonged course of antibiotics with drains in place, with the expectation that the fistula would close via this conservative approach. Her mental status recovered to baseline, and her fevers abated. The drains were subsequently removed in an outpatient setting, and she was followed closely for the next 24 months with serial imaging to evaluate her for any evidence of recurrence of the renal abscesses. On serial imaging, there were unresolving foci of gas within the treated right renal AML, and thus the decision was made to perform a partial versus total nephrectomy for definitive treatment of what was thought to most likely represent a persistent renoduodenal fistula. Surgery was performed 39 months after the initial embolization procedure. Intraoperatively, the fistulous connection was visualized, and an
123
R. A. Sheth et al.: Renoduodenal Fistula After AML Embolization
approximately 8 mm defect in the duodenum was primarily repaired. The necrotic portion of the upper pole of the kidney was debrided, but the mid and lower pole of the kidney were preserved. Two years after surgery, the patient continued to do well, with resolution of her anemia and return to baseline level of function.
renal abscesses that the diagnosis was made. In retrospect, the only suggestive evidence that could have allowed an earlier diagnosis was the persistence of gas within the treated AML. Although there are numerous potential causes for this finding, it is important to consider fistula formation to the alimentary tract, particularly in a patient with otherwise unexplainable symptoms such as chronic anemia, weight loss, or low-grade fevers.
Discussion Transcatheter embolization of renal AMLs 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 [9]. However, fistula formation between visceral organs and the alimentary tract is a rare complication of transcatheter embolization. Case reports have described bronchoesophageal fistulas occurring after bronchial artery embolization for massive hemoptysis [6]. Similarly, renocolonic [7] and renoduodenal [8] fistulae have been reported after radiofrequency ablation and cryoablation of renal masses. The mechanism by which this major complication arose in the case presented in this report is uncertain but may be attributable to the inflammatory changes that arise in response to the ischemia induced by embolization resulting in erosion into the duodenal lumen. Interestingly, Yoon et al. [10] describe a renocolonic fistula that arose after embolization of a renal arteriovenous malformation using guide wires. The putative mechanism for this patient’s complication was erosion by the guide wires into the adjacent colon; however, because the patient in our report received only a single 3 mm coil during her embolization procedure, this seems an unlikely explanation for her fistula formation. Another remarkable aspect of this patient’s case is the length of time that passed before the complication was recognized. The patient was treated for persistent anemia of unknown cause for almost a year after embolization, and it was not until the development of fulminant brain and
123
Conflict of interest Dr. Feldman has served as a consultant for Novartis Pharmaceuticals for the medical treatment of spontaneous angiomyolipomas. Rahul A. Sheth declares no conflict of interest. T. Gregory Walker declares no conflict of interest.
References 1. Rimon U, Duvdevani M, Garniek A et al (2006) Large renal angiomyolipomas: digital subtraction angiographic grading and presentation with bleeding. Clin Radiol 61:520–526 2. Steiner MS, Goldman SM, Fishman EK, Marshall FF (1993) The natural history of renal angiomyolipoma. J Urol 150:1782–1786 3. Kothary N, Soulen MC, Clark TWI et al (2005) Renal angiomyolipoma: long-term results after arterial embolization. J Vasc Interv Radiol 16:45–50 4. Chatziioannou A, Gargas D, Malagari K et al (2012) Transcatheter arterial embolization as therapy of renal angiomyolipomas: the evolution in 15 years of experience. Eur J Radiol 81: 2308–2312 5. Ewalt DH, Diamond N, Rees C et al (2005) Long-term outcome of transcatheter embolization of renal angiomyolipomas due to tuberous sclerosis complex. J Urol 174:1764–1766 6. Munk PL, Morris DC, Nelems B (1990) Left main bronchialesophageal fistula: a complication of bronchial artery embolization. Cardiovasc Intervent Radiol 13:95–97 7. Vanderbrink BA, Rastinehad A, Caplin D et al (2007) Successful conservative management of colorenal fistula after percutaneous cryoablation of renal-cell carcinoma. J Endourol 21:726–729 8. de Arruda HO, Goldman S, Andreoni C et al (2006) Renoduodenal fistula after renal tumor ablation with radiofrequency. Surg Laparosc Endosc Percutan Tech 16:342–343 9. Lee SY, Hsu HH, Chen YC et al (2009) Embolization of renal angiomyolipomas: short-term and long-term outcomes, complications, and tumor shrinkage. Cardiovasc Intervent Radiol 32:1171–1178 10. Yoon JW, Koo JR, Baik GH et al (2004) Erosion of embolization coils and guidewires from the kidney to the colon: delayed complication from coil and guidewire occlusion of renal arteriovenous malformation. Am J Kidney Dis 43:1109–1112
