{'fraction_non_alphanumeric': 0.029223744292237442, 'fraction_numerical': 0.0, 'mean_word_length': 5.682926829268292, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
An Enigmatic Route to the Contralateral Pelvicalyceal System on Antegrade Pyelogram

Introduction: The authors present the rare yet enigmatic phenomenon of ‘pyelo-renal’ backflow. Case Presentation: An eight-month-old boy with multiple congenital anomalies underwent left Anderson-Hynes Pyeloplasty for pelvi-ureteric junction obstruction. Antegrade dye-study done through the nephrostomy revealed obstruction at the level of the pelvi-ureteric junction, yet the contrast was visualized in the pelvis of contralateral kidney and urinary bladder (pyelo-venous backflow) masquerading as vesicoureteric reflux. The phenomenon of ‘pyelo-renal’ backflow along with pyelo-tubular, pyelo-interstitial, pyelo-sinusal and pyelo-lymphatic backflow have been described and the respective mechanisms discussed. Conclusion: The phenomenon is known to happen in the presence of obstruction to outflow from renal pelvis thereby creating a closed compartment. Injection of contrast at a pressure above the critical limit may result in forniceal tears and back-flow of contrast into the renal tubules and beyond.