In ureteroscopy, a common method for kidney stone removal, a ureteroscope is inserted into the patient's kidney, through which working tools such as a laser are inserted. During the procedure, the renal space proximal to the scope tip is irrigated with fluid in order to clear stone particles and debris. However, even with continual fluid flow into and out of the kidney, stone dust may become trapped in vortical structures, significantly impairing the operating clinician's field of view. Key to overcoming this challenge is a clear understanding of the flow patterns within an irrigated kidney calyx, and a modelling framework that enables to interrogate how different flow conditions impact on the wash-out time of debris. Previous theoretical studies have uncovered the interplay between fluid structure, in particular the presence of vortical regions, and dust washout, but only in a regime of steady inlet flow conditions. In this paper we model a kidney calyx in an idealised 2D cavity geometry, in which we investigate the presence and potential disturbance of vortical structures due to an oscillatory inlet condition, and the impact on dust washout, modelled as a passive tracer in the flow. By varying the flow amplitude and frequency at the inlet, we uncover a delicate relationship with vortex size and vortex disturbance, and we demonstrate the potential for significant decrease in wash-out time with low-frequency high-amplitude conditions. We then compare this result to the commonly used practice of flushing, a discrete and temporary increase in flow, and we also demonstrate the qualitative robustness of our findings to changes in cavity geometry.
Introduction and aim of study: Metachronous upper tract urothelial carcinoma (UTUC) is a rare yet aggressive malignancy that is often multifocal and invasive at the time of diagnosis. Unfortunately, the rarity of metachronous UTUC results in a paucity of targeted data, as current literature and clinical management of this tumor is largely extrapolated from that of bladder cancer. Urinary comprehensive genomic profiling with the UroAmp assay identifies six general classes of tumor-mutations present in the urine and thus, may aid in detecting UTUC when the limitations of current tools impede definitive diagnosis. We describe the utility of urinary comprehensive genomic profiling in confirming the provider's suspicion for metachronous UTUC and recommending radical nephroureterectomy.
Patient case: A 68-year-old male with a history of recurrent carcinoma in situ (CIS) of the bladder presented to the urology clinic in 2022 for continued surveillance. Abnormal soft tissue thickening surrounding the proximal right ureter, revealed on computerized tomography urography, prompted further evaluation. Selective right upper tract cytology was indeterminate, and urinary comprehensive genomic profiling was ordered to adjudicate. No tumor was visualized on ureteroscopy however the cytologic brush biopsy of the renal pelvis and proximal ureter were positive for urothelial carcinoma (UC) and/or CIS. UroAmp testing identified genomic features associated with high-grade UC, risk of invasion, and a high genomic disease burden.
Results: The patient underwent a right kidney and ureter nephroureterectomy in September 2022. Surgical pathology confirmed non-invasive multifocal urothelial CIS. A postoperative urinary comprehensive genomic profiling in February and May of 2023 detected no evidence of residual disease, consistent with complete resection of the tumor. The provider will continue intensive urinary comprehensive genomic profile monitoring coupled with conventional surveillance.
Conclusion: Urinary measurement of mutated UC genes correlate with disease burden, pathologic grade, and invasion risk and provide clinical utility when reliance on visual confirmation and cytology were not definitive or feasible.
The advent of sensitive enhanced culture (metaculturomic) and culture-independent DNA-based (metagenomic) methods has revealed a rich collection of microbial species that inhabit the human urinary tract. Known as the urinary microbiome, this community of microbes consists of hundreds of distinct species that range across the entire phylogenetic spectrum. This new knowledge clashes with standard clinical microbiology laboratory methods, established more than 60 years ago, that focus attention on a relatively small subset of universally acknowledged uropathogens. Increasing reports support the hypothesis that this focus is too narrow. Single uropathogen reports are common in women with recurrent urinary tract infection (UTI), although wider disruption of their urinary microbiome is likely. Typical "UTI" symptoms occur in patients with "no growth" reported from standard culture and sometimes antibiotics improve these symptoms. Metaculturomic and metagenomic methods have repeatedly detected fastidious, slow growing, and/or anaerobic microbes that are not detected by the standard test in urine samples of patients with lower urinary tract symptoms. Many of these microbes are also detected in serious non-urinary tract infections, providing evidence that they can be opportunistic pathogens. In this review, we present a set of poorly understood, emerging, and suspected uropathogens. The goal is to stimulate research into the biology of these microbes with a focus on their life as commensals and their transition into pathogens.

