Arterioureteral fistula after radical cystectomy and ureterocutaneostomy: two case reports and a systematic literature review

Abstract

Background

Arterioureteral fistula (AUF) is a rare, life-threatening condition wherein communication occurs between a ureter and the common, internal, or external iliac artery. The sensitivity of common clinical imaging examination for AUF is low, which leads to a delayed diagnosis and increased mortality. In addition, the increased use of ureteral stents contributes to the growing frequency of AUF.

Case presentation

Our two patients were 74 and 65 years old males respectively. They both had a medical history of bladder cancer and underwent radical cystectomy with ureterocutaneostomy. The patients underwent routine catheter exchange during over 1 year postradical cystectomy and subsequently experienced intermittent gross pulsatile haematuria. After a series of imaging examinations failed to identify the cause, the patients were ultimately diagnosed with AUF and treated with interventional radiotherapy, followed by broad-spectrum antibiotics. Positive effects were found.

Conclusions

The incidence of AUF is increased with the prolongation of survival in patients with related risk factors. This case report aims to highlight early diagnosis and management of AUF to lower the mortality.

Background

Arterioureteral fistula (AUF) is a rare but potentially life-threatening condition that was first reported in 1908 by Moschcowitz [1]. The pathophysiology of AUF involves the development of communication between a ureter and the common, internal, or external iliac artery. The causes of AUF can be divided into primary (15%) and secondary (85%) types [2]. Pelvic radiotherapy, genitourinary surgery, chronic ureteral stenting, and peripheral arterial disease are the most common secondary causes [3]. While haematuria is the most common symptom of AUF, flank pain, urinary retention, and infection have been described in the clinical as well [4]. Although AUF is uncommon, the mortality rate can reach 10% to 20% and increases in cases where the preoperative diagnosis is delayed [5]. We herein report two cases of AUF patients manifesting gross haematuria after radical cystectomy with ureterocutaneostomy.

Case presentation

Case 1

A 74-year-old male with persistent gross haematuria and flank pain was admitted to our department. He had a medical history of bladder cancer and asthma. In addition, he had severe obstructive pulmonary disease for many years. Bladder cancer was treated with radical cystectomy and ureterocutaneostomy in another hospital two years ago and the final pathology report revealed high-grade urothelial carcinoma of the bladder, stage unknown. A single-J polymeric stent was inserted and replaced every 3 months after surgery. However, a few days after the last replacement, the patient began to suffer from persistent gross haematuria and flank pain, without other significant symptoms. There was deep-red liquid and blood clots in the fistula bag. Contrast-enhanced computed tomography (CT) showed a low-density filling in the left renal pelvis. After admission, he developed haemodynamic instability and received 4 U red blood cell and 2 U haemocoagulase. After supportive treatment, the patient's symptoms were relieved significantly. The patient's urine became clear, and his vital signs gradually stabilized.

In the early morning of the third day of hospitalization, bright-red liquid and blood clots were noticed in the patient’s fistula bag. As the blood pressure (BP) is 90/60 mmHg and the heart rate is 90, his haemodynamic status was instable. Timely support treatment was given to maintain hemodynamic stability. Nonethless he continued to experience intermittent haematuria. The Interventional Radiology Department was urgently contacted, and emergent diagnostic catheter angiography was performed for suspected arterioureteral fistula. With the movement of contrast medium, a fistula was observed at the intersection of left ureter and common ipsilateral iliac artery. The patient was diagnosed with AUF (Fig. 1A–B); placement of a covered stent by endovascular treatment during interventional radiotherapy was immediately requested (Fig. 1C–D). The degree of haematuria gradually improved until disappearing and the patient was discharged 5 days after the operation with good diuresis and haemodynamic stability and remained free of gross haematuria during the 1-month follow-up. The patient was satisfied with the treatment results.

Fig. 1

A–B Left arteriogram with contrast noted a exudation through the fistula tract from left iliac artery into the left ureter. C–D No contrast agent exudation was found in both arteriogram and nephrostogram after a heparinbonded stent-graft placed in left iliac artery

Case 2

A 65-year-old male with intermittent haematuria was admitted to our department. He had a medical history of bladder cancer and accepted radical cystectomy with ureterocutaneostomy 15 months ago. Besides, He had a medical history of myocardial infarction and obstinate cardiac insufficiency. The patient’s final pathology report revealed high-grade urothelial carcinoma of the bladder, stage pT₂N₀M₀. The patient exhibited no other discomfort except the haematuria in left single-J polymeric stent. His haemodynamic status was stable. Enhanced CT and magnetic resonance imaging (MRI) were performed, but there were no findings capable of explaining the patient's clinical symptoms. Combined with the patient's medical history of pelvic surgery and long-term ureteral stent implantation, AUF was suspected. Ureteroscopy and angiography were performed to assess fistula after the correction of anaemia. However, no bleeding point was identified clearly on angiography. Rough mucosa was found 15 cm from the ureteral orifice on ureteroscopy. Then, ureteral stent implantation was performed for urine drainage. No haematuria was detected during several days of hospitalization, and the urine drained by the ureteral stent was clear. The patient was discharged 5 days after the operation and followed up regularly.

One month after returning home, the patient developed massive haematuria when the ureteral stent was replaced and accepted angiography in a local hospital. Fortunately, a fistula was found (Fig. 2A–B), and an iliac artery stent was placed. The patient was finally diagnosed with AUF. The patient's haematuria symptoms did not appear again during the 1 month of follow-up.

Fig. 2

A Left arteriogram with contrast noted extravasating through the fistula tract. B The catheter entered the ureter through the fistula of the iliac artery

Discussion and conclusion

The occurrence of AUF is not common, yet in the present era of increasing longevity and huge increases in accessibility to endoscopic interventions of the urinary tract, there is now a widespread recognition of AUF. In recent years, more than 150 cases of AUF with various causes have been reported [6]. Furthermore, AUF has become easier to diagnose due to the prolonged survival of patients with malignant tumours [7]. A review gave a summary of literature reports of 139 case reports of AUF from 1899 to 2008, in which gynaecologic cancer (28%), bladder cancer (13%), colorectal cancer (11%), other cancers (5%), untreated aneurysm (4%) and prior vascular surgery (18%) were mentioned [8]. Pregnancy-associated AUF was discussed in 3 reports [9]. Moreover, a study including 445 patients showed that 80% had chronic indwelling ureteral stents while 70% with a history of pelvic oncology, and most AUFs occurred at the common iliac artery ureteral crossing [10]. We reviewed 216 cases of 92 studies in English from the past 10 years (2011–2021) in PubMed and summarized them in Table 1. Risk factors included oncology (173 patients), ureteral stent placement (187 patients), radiotherapy (136 patients), aneurysm or pseudoaneurysm of the iliac artery (19 patients), vascular surgery (21 patients) and others (25 patients). The 213 patients in 92 studies consisted of 131 females and 82 males, with a mean age of 65.1 years (range 35–90 years). Details are provided in Table 2.

Table 1 Case reports review of past 10 years(2011–2021)

Table 2 Study group characteristics and risk factors for AUF

The pathophysiology of the formation of arterioureteral fistula is still unclear. However, it can be divided into primary iliac AUF and secondary iliac AUF according to medical history and the disease process. Primary AUF is mainly caused by aneurysm or pseudoaneurysm rupture and is associated with atherosclerosis or vascular surgery history [11]. In secondary AUF, radiotherapy and chronic ureteral stents might be risk Factors [6]. Changes in the media and adventitial layers of the large vessels are caused by prior radiation, rendering the tissues more prone to rupture, erosion and necrosis [12]. Besides long-term compression of the ureteral stent leads to tissue necrosis and fistula between the ureter and iliac vessels. Therefore, a ureteral stent replaced after the operation should be as soft and thin as possible. To prevent strong compression and abrasion of the ureteral tube wall, it is recommended that the stent be less than Fr8 [12]. If the stent tube is too hard, the ureter wall and the iliac artery, particularly the turning point of the ureter, will be under excessive pressure and forced close to the artery. In this way, a fistula can easily form under the erosion of the pulsating artery against the baseline mechanical friction caused by the pulsatile arterial flow [6]. Due to the limited fat support between the ureter and iliac vessels for patients with low BMI, this situation may also result in AUF. In patients undergoing lymph node dissection, the iliac vascular sheath is opened, exposing the vascular wall and further leading a lack of tough connective tissue protection between the iliac vascular sheath and the left ureter. The combined action might lead to fistula formation.

The most common symptom is haematuria, occasionally with flank pain. The degree of haematuria can range from intermittent bleeding to life-threatening haemorrhagic shock. In some cases obstructed clot formation in the ureter causes flank pain [2].

Although the danger of AUF has been mentioned in many studies, some patients cannot receive prompt treatment because of the difficulty of diagnosis. The most effective diagnostic method is digital subtraction angiography, yielding a diagnosis of 69% of 139 cases [8]. Angiography with concurrent manipulation of a neophroureteral stent has been shown to improve the sensitivity to 100%, which can achieve the same effect as balloon stimulation. The sensitivity of provocative retrograde pyelogram may be as low as 63% [13, 14]. Enhanced CT has less sensitivity in identifying bleeding but can be highly beneficial if active haemorrhage or a pseudoaneurysm is exist. It can also be used to rule out renal haemorrhages and plan endovascular treatment [15]. Cystoscopy may contribute to localized bleeding of the ureter.

There are two main therapeutic approaches to AUF: open surgery and endovascular treatment. Since 1996, a stent graft has been used as treatment for AUF in most patients [16]. Because of its minimally invasion and outcomes similar to those of open surgical reconstruction, endovascular treatment has become an appealing alternative to open surgical reconstruction [17]. It is important to note that intravascular stents increase the possibility of infection, which is an main factor leading to the shortening of postoperative survival [18]. Accordingly, empiric broad-spectrum antibiotics with the ability to penetrate bacterial biofilms should be used [18]. When replacing the ureteral stent regularly, use of a guide wire and a balloon with an appropriate amount of water in replacement of the ureteral stent can reduce the occurrence of AUF.

Regarding to our two cases with history of chronic ureteral stenting after radical cystectomy and ureterocutaneostomy, the priority of diagnosing AUF needs to be emphasized for patients with a history of pelvic malignancy, chronic ureteral stenting, pelvic irradiation or symptoms that include haematuria, flank pain, or both. Thus, the interval between the onset of symptoms and rapid progression of AUF may be minimized, which makes it reasonable to carry out emergency intervention without definitive imaging evidence in patients with related risk factors. The delay in clinical diagnosis may lead to the deterioration of the condition, which cannot be treated [12]. Overall, treatment results may be improved by timely angiography.

AUF is a life-threatening condition that can occur in patients with long-term ureteral stents. Although rare, AUF should be highly suspected if a patient has a medical history of pelvic surgery or pelvic irradiation in the setting of ureteral stents and haematuria. Timely interventional radiotherapy can help lower mortality.