Transarterial treatment of congenital renal arteriovenous fistulas

A Huge High-Flow Aneurysmal Renal Arteriovenous Malformation Treated With Endovascular Transcatheter Embolization

Renal arteriovenous anomalies are uncommon. They are characterized by an abnormal vascular connection that usually bypasses the capillary bed. Most are acquired arteriovenous fistulas (AVF) while the rest are congenital or idiopathic arteriovenous malformations (AVM). AVF are usually caused by renal interventions, trauma, or neoplastic processes. They can lead to hypertension, heart failure, hematuria, and renal insufficiency. A 69-year-old woman presented with arrhythmia, tachycardia, mild ankle edema, and increasing fatigue. Right kidney color Doppler ultrasound confirmed the presence of a huge AVM with a blood flow of 9 L/minute and a dilated, 35 mm in diameter, right renal vein. Two months later, an attempt to embolize the AVM failed as the Amplatzer™ Vascular Plug II (Abbott Laboratories, Chicago, Illinois, United States) migrated to the pulmonary circulation and was later removed. Complete embolization was achieved by implanting two Amplatzer Vascular Plug IIs, various embolization coils, histoacryl glue, and lipiodol. Control angiography revealed significant stenosis in the right subclavian artery endovascular access, which was managed with BeGraft (Bentley InnoMed GmbH, Hechingen, Germany) and Zilver (Cook Group Incorporated, Bloomington, Indiana, United States) stents. The patient was discharged on the third postoperative day, all her symptoms resolved, and she reported eventual recovery. Three months later, the patient was operated on due to a 40x58 mm pseudoaneurysm at the right femoral access site. Thus, renal AVMs should be included as a potential alternative diagnosis for various symptoms such as hematuria and hypertension resistant to medication. Endovascular embolization is a less-invasive, safer, and more effective option than open surgery but has a risk of complications. Success requires fully occluding the shunted vessel, preventing embolic material migration, and preserving normal arterial branches. It depends on selecting adequate techniques and embolic materials individually, based on etiology and precise vascular anatomy assessment.

Transarterial Embolization of Renal Arteriovenous Malformations: Treatment Outcomes According to Angiographic Classification

PURPOSE

To assess the different adjunctive catheter techniques required to achieve complete occlusion of renal arteriovenous malformations (rAVMs) of different angioarchitectural types.

MATERIALS AND METHODS

Overall, data on 18 patients with rAVM (Type 1, n = 7; Type 2, n = 2; Type 3, n = 9; mean age, 53.8 years) who underwent 25 procedures between 2011 and 2022 were reviewed. The clinical presentations, endovascular techniques, arteriovenous malformation (AVM) occlusion rate, adverse events (including the incidence of renal infarction), and clinical symptoms and outcomes (including recurrence/increase of AVM) were analyzed according to the Cho-Do angioarchitectural classification. Posttreatment renal infarction was classified as no infarction, small infarction (<12.5%), medium infarction (12.5%-25%), and large infarction (>25%) using contrast-enhanced computed tomography or magnetic resonance imaging.

RESULTS

Hematuria and heart failure were presenting symptoms in 10 and 2 patients, respectively. The embolic materials used were as follows: Type 1 rAVM, coils alone or with n-butyl-2-cyanoacrylate (nBCA); Type 2 rAVM, nBCA alone or with coils; and Type 3 rAVMs, nBCA alone. Fourteen patients underwent adjunctive catheter techniques, including flow control with a balloon catheter and multiple microcatheter placement, alone or in combination. Immediate postprocedural angiography revealed complete occlusion in 15 patients (83%) and marked regression of rAVM in 3 (17%). Small asymptomatic renal infarctions were observed in 6 patients with Type 3 rAVMs without any decrease in renal function. No major adverse events were observed. All symptomatic patients experienced symptom resolution. Recurrence/increase of rAVM was not observed during the mean 32-month follow-up period (range, 2-120 months).

CONCLUSIONS

Transarterial embolization using adjunctive catheter techniques according to angioarchitectural types can be an effective treatment for rAVMs.

Endovascular Treatment Failure of Renal Arteriovenous Malformation due to an Extrarenal Feeding Artery: A Case Report

Renal arteriovenous malformation (RAVM) is a rare pathology. It may present with heamturia, hypertension, and congestive heart failure. Digital subtraction angiography (DSA) is the standard diagnostic choice, and endovascular embolization is a preferred procedure of management in most cases. The feeding branches of RAVM are reported to originate from renal arteries. In this report, a 43-year-old female with recurrent massive hematuria and left flank pain was described. Renal angiography revealed double renal arteries supplying the left kidney and multiple renal arteriovenous fistula formation around the renal pelvis. Embolization with coils and gelfoam was performed after which her hematuria subsided. One month later, the patient was readmitted to our hospital due to the relapse of massive hematuria following heavy physical activities. DSA found another feeding artery of the RAVM originating from the aorta around the 4th lumbar vertebra. After embolization of this arterial feeder, hematuria settled. There was no recurrence during a 10-month follow-up. To our knowledge, this is the first case of RAVM with an extrarenal feeding artery, and omission of this scenario can lead to treatment failure.

Percutaneous intervention for giant renal extrarenal aneurysm and arteriovenous fistula

Arteriovenous fistula is a high-flow vascular malformation characterized by a direct connection between an artery and a vein without the presence of a nidus (a network of arterial and venous channels). Renal artery aneurysm concomitant with a renal arteriovenous fistula (RAVF) is extremely rare. We report the case of a 45-year-old woman with a giant renal artery aneurysm combined with RAVF who presented with gross hematuria. The patient was successfully treated by embolization of a giant extrarenal aneurism and RAVF using coils and a plug device. RAVF can lead to harmful complications, and treatment is necessary upon diagnosis. Endovascular embolization is a feasible, efficient, and safe method able to retain maximal normal renal function

Renal arteriovenous fistula complicated with malignant hypertension: a case report

Renal arteriovenous fistula (RAVF) is a rare vascular disease and is usually presented with severe hypertension. Renin-angiotensin-aldosterone system (RAAS) activation was proposed to play a key role in RAVF-induced hypertension but the data was inconsistent. We reported a case of RAVF presented as malignant hypertension, which was detected by contrast-enhanced ultrasonography and successfully managed by interventional embolization. A 35-year-old male was presented with a headache and blurred vision. His blood pressure was up to 220/110 mmHg, with significantly elevated serum creatinine and proteinuria. Hypertensive target organ impairments were noted. A RAVF was detected by contrast-enhanced renal ultrasonography. He underwent renal artery angiography and renal arteriovenous fistula embolization. RAAS activation was also evaluated by separate renal vein sampling. The patient's blood pressure and target-organ damage improved after RAVF embolization and blood pressure control. This is a rare case of renal arteriovenous fistula with malignant hypertension. Contrast-enhanced ultrasonography can be useful for diagnosis.

Treatment strategies for inferior vena cava aneurysms

OBJECTIVE

An inferior vena cava (IVC) aneurysm is a rare but potentially life-threatening entity. We successfully embolized an IVC aneurysm in a patient with history of blue rubber bleb nevus syndrome, a rare syndrome with multiple venous malformations. This new case was added to a literature review of previously reported cases, to analyze the management algorithm.

METHODS

A PubMed search for all English-language articles and abstracts of IVC aneurysm were conducted. A comprehensive descriptive analysis, including etiology, presentation, classification, comorbidities, and treatment options of our case joining all previously published cases, is presented and discussed.

RESULTS

Including our new case, a total of 74 (44 males) IVC aneurysms were analyzed. The average age was 39.0 ± 21.1 years (range, 0.4-89 years). Forty-nine (66.2%) were symptomatic; common symptoms include abdominal or back pain (24/74, 32.4%) and leg swelling or heaviness (20/74, 27.0%). Nineteen (19/59, 33.2%) were complicated with vena cava thrombosis, and 14 (14/59, 23.7%) were complicated with deep venous thrombosis of lower extremities. Thirty-two (43.2%) accepted surgical or endovascular intervention. There were 26 type I, 13 type II, 31 type III, and 4 type IV aneurysms. In type I group, 25 of 26 were treated conservatively, 2 deaths were reported. In type II group, 5 of 13 accepted conservative treatment. In type III group, 9 of 31 accepted conservative treatment, and 1 death was reported. In type IV group, 3 of 4 accepted conservative treatment, and 1 death was reported.

CONCLUSIONS

Conservative management can be conducted in type I and type IV groups with close surveillance. For type II and III groups, considering the high incidence of vena cava thrombosis and risk of rupture, more active treatment should be considered.

Endovascular Management of Renal Arteriovenous Fistula With Large Aneurysm Masquerading as a Renal Cyst

Large renal aneurysms can masquerade as simple renal cysts on ultrasound, especially if Doppler examination is not routinely done to assess flow characteristics. We present a case report of a 26-year-old male, as a clinical challenge in urology, who had minimal symptoms, yet had an arteriovenous fistula with a large aneurysm which was diagnosed as a parapelvic cyst on ultrasound. Endovascular treatment of the arteriovenous fistula was done using a vascular plug with satisfactory outcomes.

Successful endovascular embolization of large symptomatic congenital renal arteriovenous fistula in an octogenarian

Congenital renal arteriovenous fistula (rAVF) is a rare and often underdiagnosed clinical condition. Here, we present a case of a large congenital rAVF in an 81-year-old woman with a right flank bruit and high-output heart failure. The rAVF was successfully treated with percutaneous endovascular coil embolization. Complications included a small right renal hematoma, mild contrast-induced nephropathy, and small right renal infarct in the lower pole. Postoperatively, the patient had complete resolution of symptoms with salvage of the kidney. She has been observed annually for 5 years with computed tomography scan and ultrasound examination.

Renal arteriovenous malformation: An unusual pathology

Renal arteriovenous malformations are rare renal vascular abnormalities. More commonly, the term refers to the congenital type of malformation. Only a few cases have ever been presented and reported in the literature, mostly with a nidus. We present the clinical, ultrasound and computed tomography findings and discuss the management related to a 63-year-old male with a right congenital renal arteriovenous malformation without a nidus that was successfully managed with coil embolisation. Relevant literature is hereby reviewed to highlight characteristic imaging and appropriate treatment.

Embolization of hemorrhagic renal angiomyolipoma complicated by arteriovenous shunting: A case report

Arteriovenous shunting associated with angiomyolipoma is an unusual entity, which carries important implications to embolization approach. We present a distinctive case involving a 41-year-old woman who presented with retroperitoneal hemorrhage relating to renal angiomyolipoma. During angiography for urgent embolization, a complex vascular supply with arteriovenous shunting was encountered. Superselective embolization using alcohol or small particles is the standard approach to definitive treatment of symptomatic angiomyolipoma; however; their use is precluded in the setting of arteriovenous shunt hemodynamics. In this case, a 2-step approach was employed by which the initial hemorrhage was treated with proximal embolization using large gelatin foam and metallic coils. This resulted in decreased flow through the arteriovenous shunt, allowing the use high viscosity ethylene vinyl alcohol copolymer dissolved in dimethyl sulfoxide for definitive treatment.

Use of angioembolization in urology: a review

This review discusses current and developing indications for angioembolization (AE) techniques in urology cases, including trauma and non-trauma uses for kidney, prostate, and bladder conditions. AE methods, complications and technical and clinical outcomes are outlined for each indication for the purpose of aiding urologists in selecting ideal candidates for this procedure.

Long-Term Outcomes of Selective Renal Artery Embolization for Renal Arteriovenous Fistulae with Dilated Venous Sac

PURPOSE

To retrospectively evaluate the role of selective renal artery embolization for renal arteriovenous fistulae (AVFs) with dilated venous sac.

MATERIALS AND METHODS

Between 2002 and 2015, 14 patients (7 men and 7 women; mean age, 60 years) with a single renal AVF with dilated venous sac underwent selective renal artery embolization. Three patients presented with gross hematuria, 4 presented with occult blood in urine, and 1 presented with chronic heart failure. Five patients had a history of renal biopsy or partial nephrectomy. Embolic agents used included pushable fibered coils, detachable microcoils, hydrogel coils, N-butyl 2-cyanoactylate, and/or absolute ethanol. Technical success was defined as complete angiographic occlusion of the renal AVF without visualization of the venous sac. Clinical success was defined as the disappearance of the AVF on ultrasound and contrast-enhanced computed tomography, without any symptoms.

RESULTS

Fifteen sessions of selective renal artery embolization were performed. Technical success was achieved in 13 sessions (86.7%). Clinical success was achieved in 13 patients (92.9%) after a mean follow-up of 48 months (range, 6-155 months). Two major complications occurred-renal vein thrombosis (n = 1) and renovascular hypertension (n = 1)-and were successfully managed with warfarin and an angiotensin-II receptor blocker, respectively. The former patient required re-embolization because of recanalization. No significant changes were observed in the mean serum creatinine level (.86 mg/dL vs .85 mg/dL; P = .67) and the mean estimated glomerular filtration rate (66.0 mL/min/1.73m² vs 67.4 mL/min/1.73m²; P = .4) after 6 months.

CONCLUSIONS

Selective renal artery embolization is a safe and effective treatment for renal AVFs with dilated venous sac.

Endovascular Treatment of 12 Cases of Renal Arteriovenous Malformations: The Experience of 1 Center and an Overview of the Literature

Objectives:

Congenital renal arteriovenous malformations (rAVMs) represent rare vascular diseases. The heterogeneous vascular architecture of each rAVM determines the endovascular treatment techniques employed. We reported our experience with the endovascular treatment of a series of rAVMs.

Materials:

This retrospective study consisted of 12 patients with 12 rAVMs who underwent renal arterial embolization (RAE) in our hospital. Embolic materials, including particles, liquid embolic agents (n-butyl 2-cyanoacrylate, Onyx, and ethanol), and coils, were selectively used based on the decisions of interventional radiologists. Technical success was defined as the complete occlusion of the feeding arteries and nidus on postprocedure renal arteriography. Clinical success was defined as the resolution of hematuria or the disappearance of rAVM-relevant symptoms.

Results:

The median follow-up period was 13.5 months (range: 4-72). The technical success based on 12 procedures in 12 patients was 83.3% (10 of 12). In the 2 procedures that technically failed, the existence of multiple fine feeding arteries arising from the proximal portion of different segmental renal arteries explains the incomplete embolization. One of the 2 patients achieved clinical success without additional RAE. The other patient had recurrent hematuria 25 months after initial treatment, which was successfully managed conservatively with hemostatic agents. Thus, the clinical success was 91.7% (11 of 12).

Conclusions:

Renal artery embolization with the selective use of various embolic materials is an effective treatment for patients with rAVMs. The existence of multiple fine feeding vessels arising from the proximal portion of different segmental renal arteries is likely to affect the technical success of treatment.

Transarterial embolisation for congenital renal arteriovenous malformations improves clinical condition even with partial obliteration

AIM

To evaluate the efficacy and safety of transarterial embolisation (TAE), used to treat congenital renal arteriovenous malformations (CRAVMs).

MATERIALS AND METHODS

The medical records were searched retrospectively to identify patients who underwent TAE to treat CRAVM from January 2003 to August 2015. Patient demographics, clinical presentations, and imaging findings were reviewed. TAE outcomes, including complete or partial obliteration, clinical success, complications, renal function changes, and relapse of symptoms or signs after the final TAE, were assessed.

RESULTS

Over the 12-year period, 16 patients (nine male, seven female; median age, 47 years) who underwent 21 TAE procedures to treat 16 CRAVMs were enrolled in the study. The most common clinical presentation was haematuria (81.3%). Thirteen patients (81.3%) had cirsoid and three (18.7%) had aneurysmal CRAVMs. Of the 16 CRAVMs, 11 (68.8%) were peripheral, four (25%) were central, and one (6.3%) was both peripheral and central. The complete obliteration rate was 56.3%. The clinical success rate was 87.5% over a median follow-up period of 398.5 days. Two (9.5%) major complications and 14 (66.7%) minor complications were encountered. No statistically significant change in renal function was evident after TAE.

CONCLUSION

TAE was safe and effective when used to treat CRAVM; the complication profile was acceptable and renal function was preserved. TAE improved the clinical condition of CRAVM patients even when obliteration was only partial.

Renal Arteriovenous Shunts: Clinical Features, Imaging Appearance, and Transcatheter Embolization Based on Angioarchitecture

Renal arteriovenous (AV) shunt, a rare pathologic condition, is divided into two categories, traumatic and nontraumatic, and can cause massive hematuria, retroperitoneal hemorrhage, pain, and high-output heart failure. Although transcatheter embolization is a less-invasive and effective treatment option, it has a potential risk of complications, including renal infarction and pulmonary embolism, and a potential risk of recanalization. The successful embolization of renal AV shunt requires a complete occlusion of the shunted vessel while preventing the migration of embolic materials and preserving normal renal arterial branches, which depends on the selection of adequate techniques and embolic materials for individual cases, based on the etiology and imaging angioarchitecture of the renal AV shunts. A classification of AV malformations in the extremities and body trunk could precisely correspond with the angioarchitecture of the nontraumatic renal AV shunts. The selection of techniques and choice of adequate embolic materials such as coils, vascular plugs, and liquid materials are determined on the basis of cause (eg, traumatic vs nontraumatic), the classification, and some other aspects of the angioarchitecture of renal AV shunts, including the flow and size of the fistulas, multiplicity of the feeders, and endovascular accessibility to the target lesions. Computed tomographic angiography and selective digital subtraction angiography can provide precise information about the angioarchitecture of renal AV shunts before treatment. Color Doppler ultrasonography and time-resolved three-dimensional contrast-enhanced magnetic resonance angiography represent useful tools for screening and follow-up examinations of renal AV shunts after embolization. In this article, the classifications, imaging features, and an endovascular treatment strategy based on the angioarchitecture of renal AV shunts are described.

[ANEURYSMAL TYPE RENAL ARTERIOVENOUS FISTULA WITH GIANT VENOUS ANEURYSM, MIMICKING RENAL CELL CARCINOMA: A CASE REPORT]

A 39-year-old man was referred to our clinic for a 7 cm tumor in the right kidney, found by simple CT scan. It was suspected as renal cell carcinoma accompanying tumor emboli in the inferior vena cava by enhanced CT scan. For further evaluation of the tumor emboli, color Doppler ultrasound and enhanced MRI was performed. They showed a large cystic lesion with high velocity turbulent flow and flow voids in T2-weighted imaging, it seemed as giant venous aneurysm of the right renal vein. Subsequently, angiography revealed aneurysmal type renal arteriovenous fistula (AVF), transarterial embolization (TAE) of the arterial feeder with coils was performed on the same day. After 6 months from embolization, there was no recurrences or reinterventions. Color Doppler ultrasound and MRI are beneficial in distinguishing vascular disease from neoplastic disease which may sometimes mimick in other diagnostic imaging studies. In addition TAE seems to be an effective treatment for the AVF.

Endovascular intervention in renovascular disease: a pictorial review

Interventional radiologic procedures offer a significant and expanding role in the management of various renovascular diseases including renal artery stenosis, renal artery aneurysm and pseudoaneurysm, renal vascular malformations, renal tumours, trauma, and resistant hypertension. In this article, we discuss these entities in the context of currently accepted definitions, incidence, modes of diagnosis, and management as they pertain to the practice of interventional radiology. Particular emphasis is placed on current interventional procedures for managing and treating these diseases as well as emerging procedures and technologies.

• Highlights the literature on renovascular diseases

• Reviewing the role of various interventional procedures in the management of renovascular disease

• Review of imaging techniques in the identification and characterisation of renovascular disease

Open repair, endovascular repair, and conservative management of true splenic artery aneurysms

OBJECTIVE

True splenic artery aneurysms (SAAs) are a rare but potentially fatal pathology. For many years, open repair (OPEN) and conservative management (CONS) were the treatments of choice, but throughout the last decade endovascular repair (EV) has become increasingly used. The purpose of the present study was to perform a systematic review and meta-analysis evaluating the outcomes of the three major treatment modalities (OPEN, EV, and CONS) for the management of SAAs.

METHODS

A systematic review of all studies describing the outcomes of SAAs treated with OPEN, EV, or CONS was performed using seven large medical databases. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed to ensure a high-quality review. All articles were subject to critical appraisal for relevance, validity, and availability of data regarding characteristics and outcomes. All data were systematically pooled, and meta-analyses were performed on several outcomes, including early and late mortality, complications, and number of reinterventions.

RESULTS

Original data of 1321 patients with true SAAs were identified in 47 articles. OPEN contained 511 patients (38.7%) in 31 articles, followed by 425 patients (32.2%) in CONS in 16 articles and 385 patients (29.1%) in EV in 33 articles. The CONS group had fewer symptomatic patients (9.5% vs 28.7% in OPEN and 28.8% in EV; P < .001) and fewer ruptured aneurysms (0.2% vs 18.4% in OPEN and 8.8% in EV; P < .001), but no significant differences were found in existing comorbidities. CONS patients were usually older and had smaller-sized aneurysms than patients in the OPEN and EV groups. The only identified difference in baseline characteristics between OPEN and EV was the number of ruptured aneurysms (18.4% vs 8.8%; P < .001). OPEN had a higher 30-day mortality than EV (5.1% vs 0.6%; P < .001), whereas minor complications occurred in a larger number of the EV patients. EV required more reinterventions per year (3.2%) compared with OPEN (0.5%) and CONS (1.2%; P < .001). The late mortality rate was higher in patients treated with CONS (4.9% vs 2.1% in OPEN and 1.4% in EV; P = .04).

CONCLUSIONS

EV of SAA has better short-term results compared with OPEN, including significantly lower perioperative mortality. OPEN is associated with fewer late complications and fewer reinterventions during follow-up. Patients treated with CONS showed a higher late mortality rate. Ruptured SAAs are predictors of a significantly higher perioperative mortality compared with nonruptured SAAs in the OPEN and EV groups.

Embolization of a giant arterioportal fistula requiring multiple Amplatzer vascular plugs

Arterioportal fistulas (APFs) are rare vascular communications between the mesenteric arterial tree and the portal vein. The causes and presentations of this entity are varied. APFs related to tumor, infection, and trauma have been described. Patients may be asymptomatic or present with hemobilia, portal hypertension, or mesenteric steal syndrome. Small APFs require no intervention, with treatment indicated for large or symptomatic APFs. The treatment has shifted from surgical ligation or hepatic resection to an endovascular-first approach. We describe an endovascular treatment option for the management of an acquired extrahepatic (type 2) APF and present a review of the literature.