Clot stones in transplant kidneys.

We describe two cases of stones with unusual radiological characteristics in transplanted kidneys that originated from a blood clot as the nidus for lithogenesis. Both patients presented years after renal transplant, with gross haematuria. CT of the urinary tract showed a stone with a peripheral hyperdense shell (Hounsfield unit, HU >500) and a radiolucent centre (HU <100). Both patients underwent percutaneous nephrolithotomy successfully.Stone analysis showed that the outer shell was calcium oxalate monohydrate and further examination of the stone in the second case confirmed an inner layer of organised clot material. Although the management of these clot stones is similar to that of other types of stones, clinicians should be aware of such a phenomenon and investigate the patients for the possibility of stone formation after haematuria, especially in allograft kidneys.

The role of neoadjuvant chemotherapy for patients with variant histology muscle invasive bladder cancer undergoing robotic cystectomy: Data from the International Robotic Cystectomy Consortium.

OBJECTIVE: To assess the role of neoadjuvant chemotherapy (NAC) before robot-assisted radical cystectomy (RARC) for patients with variant histology (VH) muscle-invasive bladder cancer (MIBC). METHODS: Retrospective review of 988 patients who underwent RARC (2004-2023) for MIBC. Primary outcomes included the utilization of NAC among this cohort of patients, frequency of downstaging, and discordance between preoperative and final pathology in terms of the presence of VH. Secondary outcomes included disease-specific (DSS), recurrence-free (RFS), and overall survival (OS). RESULTS: A total of 349 (35%) had VH on transurethral resection or at RARC. The 4 most common VH subgroups were squamous (n = 94), adenocarcinoma (n = 64), micropapillary (n = 34), and sarcomatoid (n = 21). There was no difference in OS (log-rank: P = 0.43 for adenocarcinoma, P = 0.12 for micropapillary, P = 0.55 for sarcomatoid, P = 0.29 for squamous), RFS (log-rank: P = 0.25 for adenocarcinoma, P = 0.35 for micropapillary, P = 0.83 for sarcomatoid, P = 0.79 for squamous), or DSS (log-rank P = 0.91 for adenocarcinoma, P = 0.15 for micropapillary, 0.28 for sarcomatoid, P = 0.92 for squamous) among any of the VH based on receipt of NAC. Patients with squamous histology who received NAC were more likely to be downstaged on final pathology compared to those who did not (P < 0.01). CONCLUSION: Our data showed no significant difference in OS, RFS, or DSS for patients with VH MIBC cancer who received NAC before RARC. Patients with the squamous variant who received NAC had more pathologic downstaging compared to those who did not. The role of NAC among patients with VH is yet to be defined. Results were limited by small number in each individual group and lack of exact proportion of VH.

Holmium laser for RIRS. Watts are we doing? / Laser holmium para ureteroscopia flexible retrograda. ¿Qué estamos haciendo?

OBJECTIVE: To review recent and relevant information regarding the use of high-power (HPL) and low-power (LPL) Holmium:YAG lasers (Ho:YAG) in retrograde intrarenal surgery (RIRS) for lithotripsy. METHODS: A PubMed/Embase search was conducted and recent and relevant papers on Ho:YAG for RIRS were reviewed. RESULTS: Settings for Ho:YAG are pulse energy (PE), pulse frequency (PF), and pulse width. Currently, the majority of LPL can also adjust pulse-width but cannot reach PF as high as HPL, however, the higher energy outputs reached by HPL are rarely useful in lithotripsy. Higher PE might enhance ablation but generates larger fragments and higher retropulsion. Pulse width does not affect energy output but delivers energy for a longer time-length. Dusting and basketing are complementary techniques. Dusting seeks to pulverize stones into particles ≤250 μm avoiding the use of instruments for stone retrieval, whereas in fragmenting, the stones are break into smaller pieces which are then retrieved. Dusting can prevent the use of supplies such as access sheaths and baskets and also prevent the complications related to their use. However, is not always feasible in clinical practice to fully ablate a stone into dust, then the use of this supplies and popcorn technique are helpful for rendering a patient stonefree. The energy gap between HPL and LPL is wide and leaves room for a mid-power laser classification, which can overcome the main drawback of LPL, the expenses of HPL, and still holding its versatility for other procedures beyond stones. CONCLUSIONS: HPL and LPL have similar effectiveness, but long-term cost-effectiveness comparisons are underexplored. Newer HPL would need to be compared to emerging technologies as the thulium fiber, and prove superiority to mid-power laser to determine how powerful is enough for Ho:YAG in the years to come

OBJETIVO: El láser Holmio:YAG (Ho:YAG) es el de elección para litotricia en cirugía retrógrada intrarenal (RIRS). Los equipos láser de alto poder (HPL) y bajo poder (LPL) tienen diferentes características, por lo tanto, pueden tener diferente desempeño. En el presente trabajo tuvimos el objetivo de revisar evidencia sobre el uso de HPL y LPL en RIRS. MATERIAL Y MÉTODOS: Se realizó una búsqueda en PubMed/Embase y la información reciente y relevante sobre HPL y/o LPL en RIRS fue evaluada para una revisión monográfica. RESULTADOS: Los HPL y algunos LPL más recientes permiten al cirujano ajustar la duración del pulso, por lo tanto, al configurar un pulso largo, alta frecuencia y baja energía, se puede lograr una verdadera pulverización. Los LPL no pueden alcanzar la misma emisión de energía que los HPL. La retropulsión aumenta si la energía de pulso es mayor, entonces, se previene la retropulsión al incrementar la emisión total de energía mediante el incremento de la frecuencia. El costo de adquisión de los HPL es considerablemente mayor que el de los LPL, sin embargo, el costo a largo plazo pudiera ser similar pues los procedimientos pueden abaratarse al disminuir el uso de insumos para recuperar los litos, preservar la punta de las fibras reutilizables y disminuir el tiempo quirúrgico. CONCLUSIONES: La evidencia no favorece la efectividad de los HPL o LPL de modo abrumador. Ambos dispositivos son efectivos y seguros. No cabe duda de que los HPL alcanzan mayor emisión de energía que los LPL, pero los dispositivos de 50-80 Watts, tienen emisiones de energía que rara vez se alcanzan para litotricia y por lo tanto pudiera considerarse demasiada energía. A medida que nuevas tecnologías han surgido, la brecha entre LPL y HPL se amplía, dejando espacio para una clasificación de poder intermedio (36-55 Watts) y la comparación entre estos dispositivos sería más justa. Asimismo, los HPL aún necesitan ser contrastados en el escenario clínico, con las nuevas tecnologías disponibles, tal como la fibra de laser tulio