Spontaneous upper urinary tract rupture caused by ureteric stones: A prospective high-volume single centre observational study and proposed management.

Objective: To evaluate incidence, clinical, radiological and laboratory features of spontaneous upper urinary tract rupture (s-UUTR) due to ureteric stones and discuss their management.

Methods: Out of 1629 patients admitted to the Emergency Department (ED) for renal colic from January 2015 to December 2016 and studied by kidney US and contrast enhanced CT (CECT), 31 patients had a s-UUTR categorized in 3 stages: a) local spread, b) free fluid, c) urinoma. Presentation, therapeutic procedures and outcomes were registered.

Results: S-UUTR is reported in 1.9% of renal colic. The stone was most commonly identified at the vesicoureteric junction (VUJ) (61.3%) and mean (standard deviation, SD) stone size was 5.71 mm (2.31). S-UUTR was most frequently located in a calyx (54.84%). 26 patients (83.87%) had a clinical presentation of a renal colic, 3 cases (9.68%) had an atypical presentation and 2 (6.45%) presented an acute abdomen. In 26 cases a J-J stent (83,87%) was placed, 3 patients underwent primary ureteroscopic lithotripsy (9.67%); in 1 patient (3.23%) a nephrostomy was inserted and in 1 case (3.23%) active surveillance was adopted. Cases who underwent sole urinary derivation were revaluated after 30 days: ureteroscopic lithotripsy was performed in 48.15% of the cases; extracorporeal shock wave lithotripsy in 3.7%; in 22.2% of cases a CT demonstrated the spontaneous expulsion of the stone. 7 patients were lost at follow-up. The patient undergoing an active surveillance spontaneously expelled the stone.

Conclusions: S-UUTR is a rare radiological sign of a renal colic most commonly located in a calyceal fornix. A high incidence of s-UUTR is caused by small distal ureteral stones in which a spontaneous passage is reasonable. Clinical presentation usually does not arise the suspicion of s-UUTR. In our experience, most patients were actively treated with good results but a conservative approach can be offered in selected cases.