Causes of renal forniceal rupture

What's known on the subject? and What does the study add? Renal forniceal rupture is a common finding in patients with ureteral obstruction. It is thought to be due to increased renal pelvis pressure from backup of urine, causing one or more renal fornices to leak urine. This phenomenon has not been systematically studied. Herein we retrospectively review the causes and associated clinical findings in over 100 cases of renal forniceal rupture.

• To perform a retrospective review aiming to identify causes of renal forniceal rupture.

• A retrospective review was performed of the longitudinal medical record and CT records for patients identified as having renal 'forniceal rupture' or 'calyceal rupture' using a radiological database.

• In total, 108 patients were identified with the CT diagnosis of renal 'forniceal' or 'calyceal' rupture. • Forniceal rupture was caused by ureteric stones in 80 cases (74.1%), malignant extrinsic ureteric compression in nine cases (8.3%), benign extrinsic ureteric compression in two cases (1.9%), pelvic-ureteric junction obstruction in two cases (1.9%), vesico-ureteric junction (VUJ) obstruction in one case (0.9%), bladder outlet obstruction in one case (0.9%) and iatrogenic causes in four cases (3.7%). • No definitive cause was found in nine cases (8.3%). For patients in whom a ureteric stone was the cause of forniceal rupture, the level of obstruction was proximal ureter in 24.3% of cases, distal ureter in 17.6% of cases and VUJ in 58.1% of cases. • Mean (sd) stone size was 4.09 (2.0) mm. Mean (sd) stone size was 5.34 (1.87) mm for proximal stones, 4.08 (1.69) mm for distal stones and 3.53 (1.96) mm for VUJ stones (P= 0.005). • Urinary tract infection was present in five out of 97 patients (5.2%) in whom data were available for analysis.

• The most common aetiology of renal forniceal rupture is obstruction caused by distal ureteric stones followed by malignant extrinsic ureteric compression.