Uretero-Iliac artery fistula: a rare cause of haematuria
- 1 Urology, Houston Methodist Hospital, Houston, Texas, USA
- 2 Urology, Baylor College of Medicine, Houston, Texas, USA
- 3 Vascular Surgery, Houston Methodist Hospital, Houston, Texas, USA
- Correspondence to Dr Raj Satkunasivam; raj.satkunasivam@gmail.com
Abstract
A woman in her mid-forties with a history of cervical cancer requiring chemoradiation presented with bilateral ureteral strictures secondary to radiation therapy. The ureteral obstruction was initially relieved with bilateral percutaneous nephrostomy tubes, and subsequently, bilateral ureteral stents. Over the course of 8 months, she presented with multiple episodes of severe gross haematuria. This persisted even after stent removal and conversion back to percutaneous nephrostomy tubes. The initial evaluation, done with concern for an uretero-iliac artery fistula, which included bilateral retrograde pyelograms and CT angiography was non-diagnostic. Given continued haematuria, repeat endoscopic evaluation was undertaken; on retrograde pyelogram, brisk contrast was seen to pass into the arterial system, consistent with a left ureteroarterial fistula. The patient underwent endovascular iliac artery stent placement. Subsequently, the patient underwent resection of the iliac artery with endovascular graft in situ, left distal ureterectomy with proximal ureteral ligation following femoral-to-femoral bypass. This allowed for complete resolution of the patient’s gross haematuria episodes.
Background
Uretero-iliac arterial fistulas are a rare cause of haematuria. However, they must be considered in the differential diagnosis of a patient with intermittent haematuria and risk factors for fistula formation. Thus far, guidance on the diagnosis and management of this entity has been derived from expert opinion and case reports. There is no consensus on the optimal imaging tools for the detection of these fistulae. In this report, we present a case of an uretero-iliac fistula, with initial negative retrograde pyelogram and negative vascular angiographic assessment, and repeat retrograde pyelogram demonstrating evidence of an uretero-iliac fistula requiring endovascular management and subsequent vascular repair.
Case presentation
Mid-forties woman with a history of stage IIB cervical cancer, treated with chemotherapy and radiation 6 years prior, presented with radiation-related complications including radiation proctitis requiring diverting colostomy, bilateral hydronephrosis and recurrent pyelonephritis. Her ureteral obstruction required bilateral percutaneous nephrostomy (PCN) tubes for several years. However, the bilateral PCN tubes impacted quality of life, and was therefore converted to bilateral 6-French double-J ureteral stents. She was then lost to follow-up for 1 year, when she presented with new-onset gross haematuria, which required repeat emergency room visits and blood transfusions. Her ureteral stents were removed, bilateral PCN tubes were again placed for drainage. Despite intervention, she continued to have haematuria which required her to have multiple blood transfusions. Thus, she was then taken to the operating room (OR) for cystoscopy, with evidence of minimal radiation cystitis without active bleeding; bilateral retrograde pyelograms showed no evidence of uretero-iliac fistula. Vascular surgery was consulted, and an abdominal CT aortogram showed no fistulation between arteries close to the ureter along its course. At this point, she began hyperbaric oxygen therapy, as the radiation cystitis was thought to be the cause of the persistent haematuria. She represented to the emergency room couple weeks later with flank pain, gross haematuria, with left nephrostomy tube in place.
Investigations
Initial workup revealed severe anaemia, and cross-sectional imaging demonstrated high density material in the bladder, suspicious for clot. The need for transfusion and bright red, sudden bleeding raised the suspicion of a missed ureter-iliac artery fistula. After resuscitation, the patient underwent cystoscopy with no evidence of active bleeding. A retrograde pyelogram showed a left uretero-iliac fistula with contrast visible in the arterial system (see video 1 and figure 1). Her primary risk factors for the development of this rarely documented fistula were smoking, pelvic radiation and prolonged ureteral stent placement.
Treatment
The patient was transferred under the same general anaesthetic to the vascular OR for immediate left iliac artery endovascular stent graft placement. Approximately 1 week later, the patient underwent a femoral-femoral bypass graft, ligation of left iliac artery, and resection of the area involving the left iliac artery (with endovascular stent in situ) and adjacent ureter (with ligation proximally). The decision to resect this segment of graft and area of urinary contamination from the ureter was made to prevent endovascular graft infection in the future. In this case, the ureteral fibrosis extended proximally and there was insufficient length for urinary reconstruction, such as reimplantation with boari flap. The patient had diminished renal function (glomerular filtration rate (GFR)=21 mL/min/ 1.73 m2) and a PCN tube was left in favour of a nephrectomy.
Outcome and follow-up
The patient had resolution of haematuria, and currently has bilateral nephrostomy tubes for urinary diversion.
Discussion
Uretero-iliac arterial fistulae are rare, however, there is a recent increase in incidence due to the liberal use of ureteral stents, definitive treatment of pelvic malignancies including surgical resections and radiotherapy (table 1).1 Diagnosis requires a high index of suspicion, and management requires a prompt multidisciplinary approach with input and intervention from urologists, vascular surgeons and potentially interventional radiologists (table 2).2 Both genders appear to be equally affected. There is no preference for laterality.1 While obtaining the patient’s history, the duration and nature of haematuria (unprovoked, brisk, bright red), as well as weighing patient risk factors, is integral to identifying uretero-arterial fistulae. These risks can categorise patients into two groups: (1) patients with a history of pelvic cancer, vascular pathology, or abdominal vascular surgery and (2) patients with a history of history of pelvic radiation, urinary diversion and history of indwelling ureteral stents.2 van den Bergh et al performed a systematic review of 139 uretero-arterial fistulae, in which 54% of patients had a history of pelvic or abdominal cancer surgery, most commonly from cervical, bladder and colorectal cancer. Thirty-one per cent of these patients had history of abdominal vascular surgery including surgical reconstruction of the common iliac and/or external iliac arteries.2 Further, in a case series of seven uretero-arterial fistulae at Mayo clinic, five patients developed symptoms within 10 days of ureteral stent exchange.1
Differential diagnosis and risk factors for uretero-iliac artery fistula
| Differential diagnosis |
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| Risk factors |
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Recommended investigations for evaluation of uretero-iliac artery fistula
| Work up | |
| Complete blood count | Evaluate haemoglobin level and white cell count |
| Basic metabolic panel | Evaluate renal function and electrolyte abnormalities |
| Type and screen | High likelihood of requiring blood transfusion |
| CT—urogram | Evaluate for pelvic, genitourinary malignancy causing gross haematuria |
| Cystoscopy | Rule out bladder tumour, foreign body |
| Retrograde pyelogram | Evaluate urinary collecting system for tumour, fistula |
| Provocative angiography | Evaluate and rule our evidence of fistula, seen as contrast in the collecting system during angiography after removal of indwelling ureteral stent |
In patients with history of oncological pelvic surgery or vascular abdominal procedures, it is believed that fistulas develop from degenerative tissue changes. In this scenario, the presence of unhealthy tissue leads to a propensity of the fistula to occur near the anastomosis of arterial graft with native artery.2 Conversely, patients with previous history of indwelling ureteral stents, or urinary diversion requiring crossing of the ureter over the iliac vessels, are at high risk of uretero-arterial fistulae as the result of erosion of a pulsating artery against an inflamed ureter.2
The principle sign for uretero-arterial fistula is haematuria—in the majority of documented cases, haematuria is the only symptom for this underlying pathology. However, associated symptoms like flank pain or signs of infection can also be present.1 2 Krambeck et al developed an algorithm for diagnosis and management of uretero-arterial fistulae (figure 2). They emphasise having a high index of clinical suspicion for further workup, as diagnostic tools for uretero-arterial fistulae are limited. Provocative angiography, retrograde pyelogram or direct cystoscopy have been described as diagnostic methods. However, initial negative findings cannot rule out an uretero-arterial fistula, as also demonstrated in this case. Angiography in their study only confirmed 63%–69% of fistulae, and retrograde pyelogram confirmed 52% of the fistulae.1 2 A separately study showed provocative angiography, which requires removal of ureteral stent at the time of angiography to visualise the uretero-arterial fistula, has been reported to have a 100% sensitivity from another series published (compared with 63% found by Krambeck et al).1 3 Other methods have been described, including ureteroscopy with direct vision of the fistula.1
Algorithm for management of uretero-iliac fistula adopted from Krambeck et al.1
There is still uncertainty about the pathophysiology of the formation of a uretero-arterial fistula, It is believed that changes in the media and adventitial layers of the large arteries are caused by external beam radiation, making these tissues more prone to necrosis and rupture.1 4 Additionally, radiation can create extensive fibrosis that can obstruct the ureters, requiring ureteral stenting. Then, subsequent changes in ureteral wall elasticity and vascular changes may lead to fistula development.1 Krambeck et al recommend the use of small and the softest stent available in patients requiring indwelling ureteral stenting.1
Management of ureteroarterial fistulae requires a multidisciplinary approach, requiring vascular surgery and urology (figure 2). If managed surgically, both the artery and the ureter must be repaired. Vascular approaches include open primary repair, embolisation, ligation and extra-anatomic arterial reconstruction. Newer techniques include endovascular stenting, which can be performed during the angiography. In one case series, endovascular stenting was recommended as a temporary measure in patients who are poor surgical candidates.1 The stent by definition is prone to infection from urinary contamination, and as was the motivation in this case, it was resected in a staged manner. Survival for patients undergoing endovascular management was 100%.2 Urological management includes ureteral stenting as a temporising measure, and then possible planned nephroureterectomy, PCN tube placement, ureteral resection with primary anastomosis, or in some cases, ileal ureter creation (figure 2).1
Learning points
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Smoking, pelvic chemoradiation and the use of longstanding indwelling ureteral stents were the highest risk factors for the development of an uretero-arterial fistula.
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A high index of suspicion is required when doing a workup for a patient with these risk factors.
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Both ureteroscopic and radiologic imaging of the urinary and arterial systems, respectively, including repeated or provocative imaging, may be required to make the definitive diagnosis.
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A multidisciplinary approach, including urology, diagnostic radiology, interventional radiology and vascular surgery, is key to the successful diagnosis and subsequent treatment of a uretero-arterial fistula.
Acknowledgments
We thank Bayo Tojoula from Houston Methodist Hospital for his support.
Footnotes
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Contributors RS: conception, design, drafting, editing, final approval. NH: design, drafting, editing, final approval. BD: drafting, editing, final approval. EP: drafting, editing, final approval.
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Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
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Competing interests None declared.
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Patient consent for publication Parental/guardian consent obtained.
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Provenance and peer review Not commissioned; externally peer reviewed.
- © BMJ Publishing Group Limited 2020. No commercial re-use. See rights and permissions. Published by BMJ.
References
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