Intrarenal Arteriovenous Fistula Research Articles

Flow turbulence or twinkling artifact? A primary observation on the intrarenal color Doppler sonography

Objective The objective of this report was to describe and potentially explain differences of intrarenal color Doppler sonography (CDUS) manifestations between blood flow turbulence and twinkling artifact. Methods We retrospectively reviewed 32 cases with appearance of focally increased color Doppler signal on intrarenal CDUS from May 1, 2007, to February 28, 2009. Indications for intrarenal CDUS in 32 cases were suspicion of renovascular hypertension, investigation of complications related to renal biopsy, or hematuria. Characteristics of the color Doppler signal, relationship between color Doppler signal and renal vessels, and the spectral Doppler sampled at the anatomic site of the focal color signal were analyzed. The value and pitfall of color Doppler in the diagnosis of the intrarenal vascular abnormality and detection of renal calculus are discussed. Results Thirty-two cases with focally increased color Doppler during sonography of native or transplanted kidneys were classified into two groups: (1) turbulent blood flow—intrarenal vascular abnormalities including intrarenal arteriovenous fistula (15 cases) and intrarenal artery stenosis (eight cases); and (2) color Doppler artifact—twinkling produced by renal calculus (nine cases). There were differences in the characteristics of the color Doppler signal, the relationship between the color signal and renal vessel, and the spectral waveform on CDUS between flow turbulence and twinkling. Conclusion Flow turbulence and twinkling artifact on intrarenal CDUS are distinguishable by analyzing the manifestations on intrarenal CDUS. Proper color Doppler setting and spectral Doppler play important roles in differentiation between flow turbulence in renal vascular abnormalities and twinkling produced by renal stones.

A Safe Surgical Approach to a giant Intrarenal Arteriovenous Fistula and Aneurysm

Received November 2008 Accepted April 2009 INTRODUCTION Giant arteriovenous fistulas (AVF) pose a challenging management problem with respect to open surgery versus endovascular interventional techniques. Endovascular techniques may not be ideal for larger fistulas and may be associated with potential risks of embolism, whilst open surgery poses the risk of uncontrollable hemorrhage.(1,2) We describe a safe surgical technique for this challenging problem.

Congenital intrarenal arteriovenous malformation presenting with gross hematuria after endoscopic intervention: a case report

IntroductionAlthough diagnostic ureterorenoscopy is a minimally invasive and effective diagnostic procedure, it has the potential for significant postoperative complications. We report the first case in the literature of intrarenal arteriovenous fistulas causing hemodynamic effective anemia 4 days after ureterorenoscopic biopsy.Case presentationA 63-year-old Caucasian woman presented with hemodynamic effective macrohematuria (hemoglobin 70 g/liter) 4 days after ureterorenoscopy and biopsy of the upper pole collecting system due to recurrent microhematuria. Duplex-sonography and computed tomography angiography revealed multiple arteriovenous fistulas and erosions into the calyceal system. Intra-arterial digital subtraction angiography confirmed this condition. After superselective embolization of the arteriovenous fistulas, the patient had no further episodes of bleeding or microhematuria.ConclusionIf malignancies, urolithiasis or urinary tract infections are ruled out by common diagnostic procedures as the cause of recurrent minor or gross hematuria, the possibility of arteriovenous fistulas should be included in the differential diagnosis and Duplex-Sonography or the more invasive selective renal arteriography should be performed as this is the most definitive method for diagnosing arteriovenous fistula.

Management of post-biopsy renal allograft arteriovenous fistulas with selective arterial embolization: immediate and long-term outcomes

To evaluate the outcomes after transcatheter embolization of percutaneous biopsy-related arteriovenous fistulas in renal allografts. All post-biopsy renal-transplant vascular injuries referred for embolization between June 1999 and October 2006 were reviewed retrospectively. There were six male and six female patients with a mean age of 49.8 years (range 25-67 years); nine patients were symptomatic, three asymptomatic. Colour Doppler ultrasound (CDUS) and angiography showed one intra-renal arteriovenous fistula in 10 patients and two in two patients, combined with a pseudoaneurysm in six patients. Superselective embolization using a single catheter or coaxial microcatheter was performed with 0.035'' coils or 0.018''microcoils, respectively, in all 12 cases. 24-h creatinine clearance values before (the day of biopsy) and after (7-14 days; 3 months) the procedure were compared using the Wilcoxon signed-rank test. Physical examination and CDUS were performed after 1, 6, and 12 months, and yearly thereafter. Mean follow-up was 33.6 months. Complete definitive occlusion of the fistula was achieved consistently with a single procedure. No procedure-related complications occurred. Renal infarction was minor in all patients (0-10% in nine and 10-20% in three). Symptoms resolved completely. Creatinine clearance values obtained before and after embolization were not statistically different (p=0.168;.889 respectively). No late recurrences were reported. Transcatheter embolization with coaxial or single-catheter techniques was effective and safe for treating post-biopsy arteriovenous fistulas in renal transplants. The loss of renal parenchyma was minimal and no mid-term deterioration of allograft function was noted. The long-term survival of the renal allograft seemed to be not affected by embolization.

Intrarenal Color Duplex Ultrasonography

We analyze and discuss the importance of intrarenal color duplex ultrasonography (CDUS) in the diagnosis and differential diagnosis of vascular complications in renal transplants. We retrospectively reviewed results of CDUS, especially intrarenal CDUS, in 102 consecutive inpatients with vascular complications of renal transplants from January 1, 2000, to December 31, 2006. Correlations between CDUS and magnetic resonance angiography, digital subtraction angiography, surgical findings, and clinical diagnoses were studied. Abnormal findings on intrarenal CDUS clearly represent vascular complications primarily located at the main renal vessels and intrarenal vessels. In our study, there were 5 cases of false-negative intrarenal arteriovenous fistulas, 1 case of false-positive transplant renal vein thrombosis, and 2 cases of false-negative transplant renal artery stenosis. The accuracy of detecting vascular complications of renal transplants with CDUS was 92% (94/102). Intrarenal CDUS is a noninvasive, accurate diagnostic tool that can be administrated portably and is easily repeatable, thereby making it not only a highly valuable imaging technique but also the method of choice in screening and diagnosing vascular complications of renal transplants.

Case Report: Intrarenal Arteriovenous Fistula after Ureteroscopic Stone Extraction with Holmium Laser Lithotripsy

A 79-year-old woman presented with gross hematuria 10 days after flexible ureteroscopic stone extraction with holmium laser lithotripsy. Work-up revealed a bleeding intrarenal arteriovenous fistula that was embolized. To our knowledge, this is the first report of this complication causing delayed hematuria after ureterorenoscopy.

Rupture of an intrarenal arteriovenous fistula secondary to carcinoma: a case report.

Rupture of an intrarenal arteriovenous fistula secondary to carcinoma: a case report.

Surgical correction of intrarenal arteriovenous fistula with preservation of the kidney.

Abstract A patient with a calcified arteriovenous fistula of the left kidney was correctly diagnosed by selective renal arteriography. At surgery it was possible to identify the single vessel supplying the arteriovenous fistula and to ligate it with correction of the vascular abnormality. The end-artery characteristics of the renal arterial distribution make this surgical approach feasible and, in addition, permits the salvage of the involved kidney. Although renal arteriovenous fistula is not a common condition, with the increasing number of people having needle biopsies of the kidney as well as experiencing major abdominal injuries, its existence should be kept in mind whenever such patients develop abdominal pain, bruit, cardiomegaly, congestive heart failure, and diastolic hypertension. Early surgery is indicated, with the primary aim being the eradication of the vascular abnormality and salvage of the kidney if at all possible.

Renal vascular Doppler imaging: clinical benefits of power mode.

Power Doppler ultrasound (US) is a new technology that is superior to conventional color Doppler imaging in the detection of blood flow. Because of its greater sensitivity to flow and reduced angle dependence, power Doppler US demonstrates optimal color filling of renal pedicular vessels and allows improved evaluation of the renal parenchymal microvasculature. Power Doppler US was used as an adjunct to conventional color Doppler imaging in technically challenging cases and to improve evaluation of renal vascular disorders in a series of 916 patients. The primary clinical advantages of using power Doppler US compared with conventional color Doppler imaging include better morphologic appreciation of atherosclerotic changes in the renal artery wall, allowing improved diagnostic performance especially in hemodynamically nonsignificant plaques; ability to differentiate between subocclusive renal artery stenosis and occlusion; increased confidence in the diagnosis of renal vein thrombosis and in the assessment of caval tumor thrombus; and better appreciation of renal cortical perfusion defects. In addition, because of its greater sensitivity to perivascular artifact, power Doppler US has the potential to increase the detection rate for intrarenal arteriovenous fistulas.

Intrarenal Arteriovenous Fistula Simulating a Hypervascular Renal Tumor on Radionuclide Renal Imaging

A 45-year-old man underwent Tc-99m DTPA studies for evaluation of hypertension. The early focal increased perfusion in the right kidney simulating a hypervascular tumor was found to be an intrarenal arteriovenous fistula at surgery

ANGIOGRAPHY AND INTERVENTIONAL ASPECTS OF RENAL TRANSPLANTATION

Interventional techniques play key roles in the management of the renal transplant donor and recipient. With prompt diagnosis and intervention, postoperative vascular and urologic complications frequently may be treated by nonsurgical means. Current concepts in percutaneous intervention for renal transplant patients are discussed. Topics include transluminal angioplasty of arterial stenoses, treatment of arterial or venous occlusion, embolization of intrarenal arteriovenous fistula or pseudoaneurysm, management of periallograft fluid collections, and therapy for urinary obstruction or leak.

A successful treatment of an intrarenal arteriovenous fistula by percutaneous embolization

A 37-year-old woman patient, known to have poorly controlled arterial hypertension that was diagnosed following a cerebrovascular accident at the age of 15 years, was referred to our outpatient clinic for investigation in 1987. An intrarenal arteriovenous fistula was diagnosed by selective renal angiography. Embolization of the fistula was performed using four 15-mm/5-cm coils, which induced thrombosis and obstructed the fistula. The vascularization of the affected kidney improved immediately. During the following 4 months, the antihypertensive treatment was stopped gradually, and the patient remained normotensive. This is an unusual case of a large intrarenal arteriovenous fistula, whose etiology was not clear, that was successfully treated by percutaneous embolization.

A Successful Treatment of an Intrarenal Arteriovenous Fistula by Percutaneous Embolization

A 37-year-old woman patient, known to have poorly controlled arterial hypertension that was diagnosed following a cerebrovascular accident at the age of 15 years, was referred to our outpatient clinic for investigation in 1987. An intrarenal arteriovenous fistula was diagnosed by selective renal angiography. Embolization of the fistula was performed using four 15-mm/5-cm coils, which induced thrombosis and obstructed the fistula. The vascularization of the affected kidney improved immediately. During the following 4 months, the antihypertensive treatment was stopped gradually, and the patient remained normotensive. This is an unusual case of a large intrarenal arteriovenous fistula, whose etiology was not clear, that was successfully treated by percutaneous embolization.

Arteriovenous Fistula After Biopsy of Renal Transplant: Detection and Monitoring With Color Flow and Duplex Ultrasonography

An asymptomatic intrarenal arteriovenous fistula was incidentally discovered by color flow and duplex ultrasonography approximately 2 weeks after a percutaneous biopsy of a renal allograft. On the basis of information obtained from the color flow image and pulsed Doppler analysis, the vascular communication could be characterized without the need for angiographic correlation. The patient was managed successfully with close observation aided by serial ultrasound examinations. Spontaneous resolution of the fistula occurred within 4 weeks after the biopsy and was evident on a follow-up ultrasound examination. Duplex ultrasonography in conjunction with color flow imaging proved to be a valuable noninvasive technique for diagnosing and monitoring this postbiopsy vascular complication.

Renal arteriovenous fistula associated with fibromuscular dysplasia

A case is reported of a woman with long-standing progressive hypertension and an abdominal bruit who on angiography demonstrated fibromuscular dysplasia of the right renal artery and an arteriovenous fistula in the upper pole of the right kidney. The various causes of renal arteriovenous fistula are reviewed. The relationship of mural aneurysms seen in fibromuscular dysplasia and the formation of arteriovenous fistulas by rupture of these aneurysms is discussed. Review of the English literature indicates a probable causal relationship between fibromuscular dysplasia of the renal arteries and intrarenal arteriovenous fistulas.

Non-neoplastic congenital and acquired renal arteriovenous malformations and fistulas.

Abnormal renal arteriovenous communications were documented by renal angiography in 21 patients. Included were congenital malformations, traumatic fistulas and spontaneous fistulas associated with renal arterial disease. Each type exhibited characteristic angiographic features. Overt clinical manifestations were observed in more than half the cases. Specific treatment depended upon type, location and size of the arteriovenous communication. Small, covert renal fistulas and malformations were managed conservatively. Five medium size symptomatic intrarenal arteriovenous fistulas and one malformation were successfully treated by transcatheter embolization. Large lesions, especially when associated with renal arterial disease, may be more appropriately treated by surgery.

Intrarenal Arteriovenous Fistulas: Transcatheter Steel Coil Occlusion

Intrarenal arteriovenous fistulas are either congenital (cirsoid), acquired or idiopathic. Transcatheter occlusion of these fistulas was accomplished using the Gianturco stainless steel coil. The anatomical configuration of the feeding and draining vessels dictated the technical approach. There was considerable conservation of renal tissue as the result of this non-surgical therapeutic alternative.

Iatrogenic renal vascular injury

Bilateral arteriovenous fistulas secondary to percutaneous needle biopsy of each kidney dcrcloped in a patient with malignant hypertension and chronic renal failure. The fistulas with aneurysmal formation and hematuria were of such magnitude that bilateral nephrectomy was required fin control. The patient is now normotensive and is maintained on hemodialysis The advisability of renal needle biopsy in uncontrolled hypertension is questioned. Cases o] intrarenal arteriovenous fistulas resulting from percutaneous needle biopsy of the kidney are being reported with increasing frequency. The exact incidence of fistula formation after kidney biopsy, is unknoun but several series based on arteriographic studies show an incidence as high as IN per cent. A1though many of these fistulas disappear spontaneonsly, approximately 4 per cent persist. A review of the literature failed to reveal the incidence of aneurysmal formation. Our case was complicated by formation of bilateral renal arteriovenous fistulas secondary to repeat bilateral percutaneous needle biopsy and right open renal biopsy. Subsequent gross hematuria from the ureteral orifice also resulted which was proved by cystoscopy and required replacement with sev eral units of blood. The likelihood of rupture led to bilateral nephrectomy.

Hyperdynamic Heart Failure Due to A-V Fistula Associated With Wilms' Tumor

Intrarenal arteriovenous (A-V) fistula associated with Wilms' tumor is extremely rare and is an unusual cause of congestive heart failure in infancy and childhood. In a recent review of 440 children with Wilms' tumor, Miller et al.1 did not find a single case of A-V fistula; nor did Gomes and Bernatz2 find any Wilms' tumors in 139 patients with various forms of A-V fistula. Results of angiographic studies in children with Wilms' tumor are at marked variance as to the occurrence of A-V fistula. Whereas Hidai et al.3 and others4-6 did not find a single patient in whom Wilms' tumor was associated with intrarenal A-V fistula, Cremin et al.7 and Meng and Elkin8 reported such an association in two of 13 and one of 6 children, respectively.

Intrarenal arteriovenous fistula: documented increase in size during an eight-year interval in one case and surgical treatment with renal salvage in another.

Two cases of intrarenal arteriovenous fistula are presented, one with a large increase in fistula size during an eight-year interval and the other demonstrating renal salvage after excision of the fistula. The former represents the first such documentation of interval enlargement of a nontraumatic intrarenal fistula and the latter adds to the small number of documented cases treated by fistula excision with renal salvage, a result greatly aided by arteriographic description of the lesion.