Ureteroarterial fistula: A review of the literature

Abstract

Ureteroarterial fistulas are rare, erosive defects that occur between the distal segments of the ureter and the adjacent blood vessels in individuals with urologic and vascular comorbidities. Characterized by diffuse, pulsatile bleeding into the urinary tract, this condition carries a significant mortality rate in the absence of early recognition. Recent treatment efforts have focused on use of endovascular stenting techniques as an alternative to open surgical closure of the underlying defects in hemodynamically stable patients. We provide a literature review detailing the characteristics, mechanism, and management of ureteroarterial fistulas.

Keywords

Ureteroarterial fistula ureteroiliac fistula arterioureteral fistula ilioureteral fistula hematuria

Introduction

Ureteroarterial fistulas (UAF) are a rare and potentially life-threatening emergency which require a rapid and multidisciplinary approach to both diagnosis and treatment. Initially described in patients with chronic indwelling ureteral stents, subsequent reports of UAF demonstrate frequent associations with pelvic or genitourinary surgery and radiation as well as underlying vascular disease and intervention.^1,2 Diagnostic and therapeutic approaches to UAF evolved from surgical exploration and open repair to angiographic evaluation and endovascular intervention.^3,4 Acute mortality associated with UAF has reportedly ranged from 10% to 38%.^1,3 Herein, we provide a review of the literature detailing the characteristics, diagnosis, and treatment of UAF.

Materials and methods

We conducted online searches of all case reports and case series of UAF. The PubMed and EMBASE databases were queried with the following terms “ureteroarterial OR ureterovascular OR arterio-ureteral OR ureteroiliac AND fistula.” Publications were considered for review if they included a diagnosis of UAF from surgical or radiographic investigation.

For each included case, patient demographics as well as surgical, oncologic, vascular and urologic histories were captured within a standardized template. Incidences of particular surgical procedures (including history of urinary diversion) and cancer types were compared across cases. Clinical presentation was characterized by presence or absence of gross hematuria, circulatory compromise, and flank pain. Diagnostic workup was classified as surgical exploration, angiographic (with or without provocative maneuvers), or involving ureteral contrast or computed tomography.

Anatomic incidence of UAF was described, when available, according to the fistula’s arterial location. Treatments were organized as open repair and/or bypass, endovascular, or other alternative treatments. Success of diagnostic modalities was defined as being of assistance to the patient’s diagnosis, while success of treatment modalities was defined as perioperative survival without acute need for revision or further treatments.

Results

Our search yielded 61 case reports and case series which included a total of 118 individual UAF cases occurring from 1908 to 2013. Patient demographics and known risk factors are characterized in Table 1. Female patients with UAF were more common than males (approximately 3:2 ratio), and a wide age range was observed from 6 to 88 years old with a mean age of 61. Interestingly, patients aged 50 years or younger with UAF were predominantly female (21 of 26).

Table 1.

Demographics and clinicopathologic characteristics.

	n	%
Female/Male	75/43
Mean age (range)	61 (6–88)
Presentation
Gross hematuria	118	100
Circulatory instability	21	17.8
Precipitated by ureteral manipulation	16	13.5
Flank pain	9	7.6
Indwelling ureteral stent	87	73.7
History of malignancy	83	70.3
Gynecologic	39	33.1
Cervical cancer	30	25.4
Urologic	22	18.6
Bladder cancer	20	16.9
Colorectal	17	14.4
Pelvic/Abdominal surgery	82	69.5
Ileal conduit	25	21.2
Vascular surgery	25	21.2
Pelvic exenteration	21	17.8
>1 Pelvic/Abdominal surgery	16	13.6
Cutaneous ureterostomy	8	6.8
Pelvic/Abdominal radiation	57	48.3
Vascular pathology	49	41.5

Clinical presentation of UAF universally involved gross hematuria, with 17.8% of patients presenting with circulatory compromise. Ureteral manipulation, usually in the setting of a chronic stent exchange, precipitated the UAF’s symptoms in 13.5% of cases.

Risk factors associated with UAF, as previously described, were present in all patients. The most common risk factor seen was presence of a chronic indwelling ureteral stent, found in 73.7% of patients. Nearly as common was a history of malignancy, with cervical, bladder, and colorectal cancers being the most frequently observed (25%, 22%, and 17%, respectively). Abdominal and pelvic surgeries (the majority of which were oncologic procedures) were reported in 69.5% of patients, including urinary diversion in 30% of patients. Pelvic radiation and vascular pathology were found in 48.3 and 41.5% of patients, respectively.

Anatomic incidence of UAF was divided into patients with and without a history of urinary diversion (Figure 1). Previous reviews have found a slightly increased incidence of UAF in left-sided locations in patients with a history of a urinary diversion.⁵ It should be noted that anatomic description was not sufficiently reported to characterize in 26% of patients without urinary diversion and 25% of patients with urinary diversion. The majority of UAF’s in each group were reportedly located at the common iliac artery (61% in patients with diversion, 60% in patients without diversion), with external iliac artery being the second most frequent location in both groups. Three UAF’s in our reviewed cases were reported to have involved the aorta.^6–8 No patients with history of urinary diversion had a UAF at the internal iliac artery.

Figure 1.

Anatomic incidence of ureteroarterial fistulas in patients with and without urinary diversion.

Diagnostic modalities were found to have shifted from predominantly surgical exploration in earlier reports to angiographic evaluation.³ Vascular contrast studies, in addition to avoiding the obvious morbidity of surgical exploration, have been described as advantageous in that they allow diagnosis of UAF in a setting which allows rapid deployment of either an endovascular stent graft or coil embolization of affected vasculature in appropriate cases (Table 2).

Table 2.

Diagnostic and treatment strategies of ureteroarterial fistulas.

Diagnostic strategies	n performed	n diagnostically useful
Surgical exploration	45	42
Cystoscopy	34	26*
Ureteral contrast studies	26	16
Vascular contrast studies	76	55
Provocative angiography	28	21
Computed tomography	36	13
Treatment strategies	n performed	n successful
Open repair/bypass	55	45
Endovascular stent graft	37	31
Other
Ureteral tamponade	2	2
Renal artery embolization	4	0
Nephrectomy ± Ureterectomy	16	4

*Cystoscopy revealed pulsatile bleeding at ureteral orifice or fresh thrombus in ureteral stent in 26/34 patients.

Treatments for UAF similarly changed over time from predominantly open repair and coil embolization with bypass to the incorporation of endovascular stent grafts. Long term data comparing open repair to endovascular stent grafts is only available in a small minority of patients with UAF’s and showed no significant difference in rates of recurrence or complications such as limb ischemia.^3,7 A commonly accepted contraindication to placement of an endovascular stent graft is evidence of a complex, contaminated fistula due to increased risk of infection, sepsis, and graft failure.^3,9

Clinical presentation

Ureteroarterial fistulas represent an elusive, yet diagnostically important consideration in the context of the patient with hematuria. It has been postulated that the rising incidence of reported UAF’s reflects expanding therapeutic options for patients with advanced cancers or severe vascular pathology.^2,3,10 According to a literature review by Madoff et al.,¹¹ the mortality rate in the absence of preoperative diagnosis was nearly 64%, but fell to a mere 8% when UAF was identified before surgery. Therefore, an early diagnosis should be aggressively pursued in cases of suspected UAF to ensure that unnecessary delays in subsequent management can be avoided.

Imaging and diagnosis

Initial clinical evaluation of UAF can be challenging for multiple reasons. The presenting symptoms of UAF can be nonspecific and only transiently present at the time of initial workup. These features can include urinary retention, fever, or flank pain which is thought to be caused by the passage of blood distending the affected renal collecting system.^1,11 However, the most common presenting symptom of UAF is hematuria, which is seen exclusively in up to 74% of cases.⁵

Although not universally informative, imaging studies can be useful in the work-up of UAF. Of the available imaging options, selective arteriography appears to be the most effective modality.^4,10,12–14 After injecting dye into the iliac vasculature, direct extravasation of contrast through the ureteroarterial defect is documented along with subsequent opacification of the contiguous ureter (Figure 2). Several other nonspecific findings have also been reported in conjunction with UAF.

Figure 2.

Direct extravasation of contrast through the ureteroarterial defect along with subsequent opacification of the contiguous ureter.

As an alternative to arteriography, anterograde or retrograde ureterogram can be used to document direct contrast extravasation from the ureter to the arterial circulation. In a review by van den Bergh et al.,⁵ arteriogram and ureterogram helped to establish UAF diagnosis in 69% and 52% of their respective uses, thus outperforming all other imaging modalities. However, other reports have described lower diagnostic yield, with selective iliac arteriography thought to possess only a 50% sensitivity despite being one of the most useful diagnostic tests for UAF.¹¹

Few other effective options exist for UAF detection. In some cases, cystoscopy can help lateralize the potential UAF to a particular side by documenting passage of pulsatile blood from the corresponding ureteral orifice. Additional confirmatory studies are almost always required in conjunction with cystoscopy to guide appropriate treatment. CT scans are also unlikely to provide direct confirmation of UAF, more often showing nonspecific findings such blood clot formation in the renal pelvis and hydronephrosis rather than the discrete erosive structural wall defect necessary for diagnosis.⁷

Pathophysiology

UAF are caused by inflammation or chronic degenerative processes that lead to erosion of the ureteral wall into the adjacent vasculature.^1,5 The baseline mechanical friction provided by the pulsatile arterial flow in direct contact with the ureter is thought to underlie this irritation, eventually producing breakdown between these structures. Primary causes of UAF, comprising 15% of all known cases, are associated with intrinsic structural weakening of the involved artery or ureter. These etiologies mainly consist of preexisting aortoiliac aneurysms but also, rarely, include arteriovenous malformations, both of which ultimately contribute to thinning of the arterial wall. Representing the remaining 85%, secondary causes of UAF extrinsically influence fistula formation by causing extensive pelvic fibrosis, enhancing local inflammation, or by rerouting pertinent structures within close proximity of one another.¹¹ These include vascular (prior arterial graft placement, endovascular manipulation, surgery), urologic (urinary diversions, indwelling stents, ureteral strictures), or other causes such as previous abdominopelvic surgery, cancer, or local radiation.

Treatments

Treatment of UAF requires a multidisciplinary approach to close the uretero-arterial communication while controlling blood loss. In an increasing number of cases, use of endovascular procedures has become an appealing alternative to traditional open surgery given its less invasive nature and the frequency of complicated anatomic presentation in most patients secondary to previous comorbidity. A series of 11 patients treated with endovascular stent placement by Okada et al.⁷ reported only one UAF-related death after treatment with 76.2% and 40.6% of patients remaining hematuria free at 1 and 2 years, respectively. However, a separate series of 19 patients by Fox et al.³ revealed no clear advantage of endovascular stent grafts over open surgical repair when comparing outcomes of early mortality and complications. However, stent occlusion and lower extremity ischemia have both been reported as complications of endovascular stent grafts.

In patients who’s UAF is not amenable to endovascular intervention and for those with secondary complications, alternative efforts may be necessary. Options in these cases include vascular bypass grafting, proximal arterial ligation, open vessel repair, and, in some cases, nephrectomy if irreversible damage to the renal collecting system has occurred.

Conclusion

Ultimately, having a high clinical suspicion for UAF is imperative in the context of a patient with predisposing comorbidities who presents with hematuria. With early recognition and expedient management, the risk of mortality and complications can be substantially reduced. Imaging studies, including provocative arteriography and anterograde/retrograde ureterogram, can be useful aids in establishing the diagnosis if it remains unclear at the time of clinical presentation. In terms of treatment, endovascular stenting has emerged as an appealing initial modality and should be considered in stable patients with less favorable candidacy for open surgical intervention secondary to preexisting comorbidities.

Disclosures

This paper was not an animal or human study, therefore there was no approval sought by the Institution Review Board or Ethics Committee.

Footnotes

Declaration of conflicting interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

References

Batter

McGovern

Cambria

. Ureteroarterial fistula: Case report and review of the literature. Urology 1996; 48: 481–489.

Van den Bergh

RCN

Moll

de Vries

J-PPM

. Arterio-ureteral fistula: 11 new cases of a wolf in sheep’s clothing. J Urol 2008; 179: 578–581.

Fox

Krambeck

McPhail

. Ureteroarterial fistula treatment with open surgery versus endovascular management: Long-term outcomes. J Urol 2011; 185: 945–950.

Quillin

Darcy

Picus

. Angiographic evaluation and therapy of ureteroarterial fistulas. AJR Am J Roentgenol 1994; 162: 873–878.

Van den Bergh

RCN

Moll

de Vries

J-PPM

. Arterioureteral fistulas: Unusual suspects-systematic review of 139 cases. Urology 2009; 74: 251–255.

Kutikov

Van Arsdalen

Levin

. Communication between the ureter and an aortic aneurysm sac after an abdominal aortic aneurysm repair. Urology 2008; 71: 351.e7–8.

Okada

Yamaguchi

Muradi

. Long-term results of endovascular stent graft placement of ureteroarterial fistula. Cardiovasc Intervent Radiol 2013; 36: 950–956.

Horikawa

Saito

Hokotate

. Treatment of ureteroarterial fistula with an endoureteral stent graft. J Vasc Interv Radiol 2012; 23: 1241–1243.

Malgor

Oderich

Andrews

. Evolution from open surgical to endovascular treatment of ureteral-iliac artery fistula. J Vasc Surg 2012; 55: 1072–1080.

10.

Krambeck

DiMarco

Gettman

. Ureteroiliac artery fistula: Diagnosis and treatment algorithm. Urology 2005; 66: 990–994.

11.

Madoff

Toombs

Skolkin

. Endovascular management of ureteral-iliac artery fistulae with Wallgraft endoprostheses. Gynecol Oncol 2002; 85: 212–217.

12.

Vandersteen

Saxon

Fuchs

. Diagnosis and management of ureteroiliac artery fistula: Value of provocative arteriography followed by common iliac artery embolization and extraanatomic arterial bypass grafting. J Urol 1997; 158: 754–758.

13.

Gelder

Alvarez

Partridge

. Ureteroarterial fistulae in exenteration patients with indwelling ureteral stents. Gynecol Oncol 1993; 50: 365–370.

14.

Yamasaki

Omori

Takaoka

E-I

. Successful management by provocative angiography and endovascular stent of Ureteroarterial fistula in a patient with a long-term indwelling ureteral stent. Jpn J Clin Oncol 2010; 40: 267–270.