Gross hematuria caused by a congenital intrarenal arteriovenous malformation: a case report

Endovascular Embolization of Aneurysmal Renal Arteriovenous Malformation

Renal arteriovenous malformations (AVM) represent an uncommon vascular condition characterized by an abnormal direct communication between an intrarenal artery and vein. Though asymptomatic in many individuals, treatment is often indicated if the AVM causes flank pain, hematuria, or medically refractory hypertension, or if there is an associated renal artery aneurysm. We present a case of a large right renal AVM with associated renal artery aneurysm and large varix which was incidentally found on magnetic resonance imaging of the spine. Endovascular and open surgical options were considered, including ex-vivo renal vascular reconstruction and nephrectomy. The patient was successfully treated with endovascular embolization of the AVM with coil packing of the arterial aneurysm and inflow artery. The patient recovered uneventfully with well-maintained renal function and blood pressure control. We review and discuss the literature on the etiology and treatment options for renal AVM.

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.

Fogarty-assisted transcatheter embolization of a large renal high-flow arteriovenous fistula

Background

Renal high-flow arteriovenous fistulas and its complications may involve high output heart failure, hematuria, hypertension or lethal hemorrhage.

Case presentation

This case report covers the case of a 65-year-old male patient with a large renal high-flow arteriovenous fistula of the right kidney (RAVF), treated with balloon-assisted coil and liquid (n-Butyl Cyanoacrylate) embolization. By use of ballon-occlusion with an over-the-wire Fogarty catheter and advancement of a microcatheter through the lumen distal to the balloon during the transcatheter embolization of a high-flow RAVF, control of arterial blood flow is feasible by temporary occlusion of the afferent artery. This technique of flow modulation facilitates controlled deployment of embolization materials and decreases the risk of inadvertent distal embolization by use of only one 6-French (F) arterial sheath.

Conclusions

Balloon-assisted embolization using a Fogarty occlusion catheter represents a feasible, safe and effective treatment option for the treatment of large, high-flow arteriovenous fistulas of the kidney.

Congenital Renal Arteriovenous Malformation: Diagnostic Clues and Methods

Background and objectives: Renal arteriovenous malformation (AVM) is a rare disease and is difficult to be diagnosed by conventional methods because of its rarity. In this study, we investigated the diagnostic clues, and made an algorithm for the better diagnosis of renal AVM. Materials and Methods: We reviewed 13 patients who were diagnosed with AVM by using renal angiography from 1986 to 2020 at our institutes. We evaluated clinical features, diagnostic tools, treatment modalities, and outcomes after the treatment of patients. Results: All patients were female, and the mean age was 36.9 years (range 19 to 54 years). Twelve (92.3%) patients complained of gross hematuria. Four (30.8%) patients showed symptoms in relation with pregnancy and delivery. Angiographic findings demonstrated cirsoid type in 10 patients and aneurysmal type in 3 patients. Among the 11 patients who underwent computed tomography, AVMs were detected in 3 (27.3%) patients. Renal duplex Doppler was performed in 6 patients, and all of these patients were diagnosed with AVM, demonstrating a vascular turbulence or blood-rich area. Twelve patients were initially treated with transarterial embolization. Nephrectomy was performed in two patients due to persistent bleeding with hypovolemic shock. Conclusions: We should consider possible AVMs in patients who were not detected by conventional work up for hematuria, especially in mid-aged, pregnant, or recently delivered women. Renal duplex Doppler might be the optimal diagnostic modality in these patients. Our diagnostic algorithm could be aid to diagnosis and treatment for renal AVM patients.

Use of a 4 mm Amplatzer Vascular Plug II in the treatment of a renal arteriovenous fistula: a case report

Background

We report the use of a 4 mm vascular Amplatzer for the occlusion of a renal arterovenous fistula between the renal artery, at the hylum trifurcation point, and an aneurismatic vein draining into the main renal vein, where there was no possibility to use any other device from the venous side, because of the diameter and the high flow, neither from the arterious side without sacrificing lobar branches. The device was implanted at the exact point of communication, like a patent foramen ovale occluder, with the distal disc into the artery lumen and the other two proximal discs into the venous side.

Case presentation

A 34-years-old Caucasian woman suffered several episodes of paroxysmal supraventricular tachycardia associated with dyspnoea, after the onset of post-pregnancy hypertension. She underwent CTA, spectral Doppler sonography and angiography which showed a renal arteriovenous fistula (RAVF) between the renal artery, at the hylum trifurcation point, and an extremely ectatic vein draining into the main renal vein of the right kidney.

With both arterial and venous access, the RAVF was selectively embolized using a 4 × 6 mm Amplatzer Vascular Plug II, released into the communication between artery and vein ensuring the patency of vessels involved.

The RAVF was almost completely excluded and the hemodynamic effects associated were also corrected.

Conclusions

The use of this device, though in an alternative way, allowed the exclusion of the high flow A-V fistula without sacrificing any parent renal vessel and preserving the renal function.

Massive hematuria due to an autogenous saphenous vein graft and urinary bladder fistula in an extra-anatomic iliofemoral bypass: a case report

INTRODUCTION

Gross hematuria caused by rupture of an artery in the urinary tract is a rare but potentially fatal condition. Iliac artery aneurysms, pelvic surgery with radiation, vascular reconstructive surgery, surgery for stenosis of the ureteropelvic junction, and transplantation are reported to be associated with this condition. In the vascular reconstructive surgery group, the most common etiology is rupture of the degenerated artery or synthetic graft in the ureter.

CASE PRESENTATION

We present a case of rupture of the small anastomotic pseudoaneurysm at the proximal anastomosis of a right iliofemoral autogenous vein extra-anatomic graft in the urinary bladder. To our knowledge, this is the first report of a rupture of an autogenous vein graft in the urinary bladder. Our patient, a 24-year-old Albanian farmer, was admitted to the emergency department in severe hemorrhagic shock induced by exsanguinating hematuria. He underwent immediate surgery, during which direct sutures to the bladder were placed and the saphenous graft was replaced with a synthetic one. The patient recovered completely, was free of hematuria, and showed no signs of pathological communication between the urinary and arterial tracts on postoperative cystoscopy and computed tomographic angiography during 2 years of follow-up.

CONCLUSION

The incidence of artery-to-urinary tract fistulas is growing due to the increasing use of urologic and vascular surgery, pelvic oncologic surgery, and radiation therapy. In addition to fistulas involving a degenerated artery and ureter or synthetic grafts and ureter, they can also involve an autogenous vein graft and the urinary bladder. In our patient, the fistula was a result of erosion of the bladder from a pseudoaneurysm at the proximal anastomosis of an autogenous vein iliofemoral bypass in an extra-anatomic position. Open surgery remains the best treatment option, although there is increasing evidence of successful endovascular treatment.

Management of renal arteriovenous malformations: A pictorial review

Background

Arteriovenous malformations (AVMs) are communications between an artery and a vein outside the capillary level. This pathologic communication may be either a fistula, a simple communication between a single artery and a dilated vein, or a more complex communication, a nidus of tortuous channels between one or more arteries/arterioles and one or more draining veins. The latter type of lesion is most frequently seen in the extremities; in the kidney they tend to appear more rarely. The most common clinical presentation of renal arteriovenous malformations (RAVMs) is haematuria. Percutaneous treatment with selective endovascular techniques offers a minimally invasive, nephron-sparing option in comparison to the more invasive surgical approaches. The purpose of this pictorial review is to highlight the general lines of management and to show the range of imaging findings of the percutaneous treatment of RAVMs.

Methods

The imaging characteristics of a selection of cases of percutaneously managed congenital RAVMs are presented and the most common lines of approach are discussed.

Conclusion

The imaging spectrum of diagnosis and percutaneous treatment of RAVMs is presented in order to aid interpretation and endovascular management.

Teaching points

• Renal arteriovenous malformations are very rare lesions.

• Clinical expression is usually haematuria.

• Diagnosis is made with CT or MRI but the gold standard is digital subtraction angiography.

• Catheter-directed treatment with the use of coils or liquid embolics is minimally invasive, safe and effective.

Complete Renal Artery Embolization in a Comorbid Patient with an Arteriovenous Malformation

Renal arteriovenous malformations are uncommon and are rarely a cause for presentation. However, they can occasionally pose life-threatening problems. We present a case of an elderly female who underwent a complete left renal artery embolization, following a difficult presentation complicated by advanced dementia and multiple comorbidities. This is the first documented case of complete renal artery embolisation used to treat a renal AVM.

The role of transarterial embolization in the management of hematuria secondary to congenital renal arteriovenous malformations

OBJECTIVE

To evaluate the efficacy and safety of transarterial embolization (TAE) in the management of hematuria secondary to congenital renal arteriovenous malformations (AVM).

PATIENTS AND METHODS

Between May 2007 and February 2012, 6 patients with congenital AVM treated with TAE were analyzed retrospectively, followed by a brief review of TAE in the treatment of congenital AVM. Clinical records with respect to general conditions, location, embolic materials, complications and overall outcome were collected from the original hospital charts and outpatient medical records.

RESULTS

Three patients with AVM were confirmed by contrast-enhanced CT scans, and the other 3 patients were detected by renal angiography. TAE was performed with steel coils in 2 patients and n-butyl-2-cyanoacrylate (NBCA) in 4 patients. After a mean follow-up of 22 months, no serious adverse effects were observed in all patients. There were no complaints of hematuria at the end of the follow-up period.

CONCLUSION

For unexplained massive hematuria, congenital renal AVM needs to be considered as a differential diagnosis. Selective renal angiography and embolization should be recommended as the first choice to treat massive hematuria secondary to congenital renal AVM.