Introduction

Semirigid ureteroscopy and holmium laser is considered first-line therapy for many patients with ureteral stones. In recent years, flexible ureteroscopy and holmium laser or thulium fiber laser has become a first-line therapy option for kidney stones.¹ During these procedures, the risk of major complications is low, but in some cases this may pose a risk of serious morbidity and even mortality.² These rare complications can include the development of arteriovenous fistula (AVF). In most cases, AVF is satisfactorily treated with arterial embolization, but some cases require nephrectomy because of unsuccessful embolization and persistent bleeding.² Our aim is to show a rare case of nephrectomy after semirigid ureteroscopy due to persistent bleeding.

Case Report

In our center, a 61-year-old male patient presented with a 7-day history of left flank pain. He had a history of 2 previous ureteroscopies and 1 session of extracorporeal shock wave lithotripsy for ureteral and kidney stones. The patient also had a history of cardiovascular disease under medical treatment (aspirin, clopidogrel and diltiazem).

A computerized tomography (CT) scan demonstrated a 4 mm proximal ureteral stone and 8 mm lower pole calyceal stone. The opposite kidney was atrophic because of unknown cause. Preoperative creatinine was 1.7 mg/dl and hemoglobin was 13.7 gm/dl. Semirigid ureteroscopy was elected as treatment for the proximal ureteral stone. During the procedure, ureteral stenosis with an impacted stone was found. Partial laser lithotripsy was performed due to ureteral wall edema and a double-J stent was placed.

After 2 weeks, the patient was rehospitalized with severe hematuria (hemoglobin dropped to 7.1 gm/dl) and renal failure (creatinine 3.1 mg/dl). CT scan demonstrated multiple clots in the kidney, ureter and bladder. Blood transfusion was undertaken and cystoscopy with clot evacuation was performed. Ureteroscopy showed multiple clots throughout the ureter. Double-J stent relocation was performed and embolization was elected. Antiplatelet therapy was suspended and replaced by enoxaparin 40 mg/day due to Hematology Department indications.

Figure 1. Superselective arterial embolization.

Figure 2. CT scan showing contrast leakage persistence.

Figure 3. Clots in upper calyx.

Endovascular embolization with coils was performed (Fig. 1). Left renal arteriography showed an upper calyx AVF and pseudoaneurysm. Coil embolization was achieved successfully. Three days after embolization, gross hematuria recurred and hemoglobin dropped again. CT scan evidenced persistence of AVF and contrast leakage (Fig. 2). A second embolization was performed with similar findings and results to the first procedure, but the patient became hemodynamically unstable and surgical exploration was required.

Open nephrectomy was performed and multiple clots were found in the renal urinary system (Fig. 3). After surgery, hematuria resolved and the patient had good recovery. He remained hospitalized for another 2 weeks because of antibiotic treatment, with good clinical recovery. After 6 months, he is stable with chronic renal disease because of the atrophic contralateral kidney (creatinine 2.8 mg/dl), and in joint followup with Nephrology with no dialysis requirement.

Discussion

AVF is a well-known complication after percutaneous nephrolithotripsy,³ but is extremely rare after pure endoscopic procedures such as semirigid ureteroscopy or flexible ureteroscopy. In these surgeries, treatment is performed entirely through the urinary tract, avoiding potential damage to the renal vessels caused by percutaneous access, which leads to a very low reported incidence of hemorrhage following ureteroscopy (0.15%–0.4%).^4,5

The exact physiopathology of bleeding in these cases remains unclear, but it may be caused by the damage produced to the pelvicalyceal system by the guidewire and the elevated pressure the kidney is subjected to during ureteroscopy, generating rupture of the renal parenchyma and bleeding.^4,6 In our case, extracorporeal shock wave lithotripsy and previous surgeries which the patient underwent may have contributed to the parenchymal damage, but this remains unclear.

Endovascular superselective embolization is the first option to treat bleeding originating in AVFs.⁷ This usually produces complete cessation of bleeding and occlusion of the vascular lesion. The side effect of this procedure is that it reduces functional kidney tissue, and it is common to observe a predictable decrease in renal function after performing an embolization.⁴ Nephrectomy is our final choice to solve this uncommon but life-threatening complication,⁴ which was performed in our case after 2 embolizations without resolution and persistence of bleeding.

Conclusion

This case highlights the importance of maintaining low pressure during endoscopic procedures. Being aware of the constant outflow of irrigation solution is key. Semirigid ureteroscopy and flexible ureteroscopy have excellent safety profiles, but in a limited number of cases life-threatening complications may occur. Fast and accurate management is needed to handle these events.