Prone vs supine percutaneous nephrolithotomy: does position affect renal pelvic pressures?

The purpose of this study was to measure and compare renal pelvic pressure (RPP) between prone and supine percutaneous nephrolithotomy (PCNL) in a benchtop model. Six identical silicone kidney models were placed into anatomically correct prone or supine torsos constructed from patient CT scans in the corresponding positions. A 30-Fr renal access sheath was placed in either the upper, middle, or lower pole calyx for both prone and supine positions. Two 9-mm BegoStones were placed in the respective calyx and RPPs were measured at baseline, irrigating with a rigid nephroscope, and irrigating with a flexible nephroscope. Five trials were conducted for each access in both prone and supine positions. The average baseline RPP in the prone position was significantly higher than the supine position (9.1 vs 2.7 mmHg; p < 0.001). Similarly, the average RPP in prone was significantly higher than supine when using both the rigid and flexible nephroscopes. When comparing RPPs for upper, middle, and lower pole access sites, there was no significant difference in pressures in either prone or supine positions (p > 0.05 for all). Overall, when combining all pressures at baseline and with irrigation, with all access sites and types of scopes, the mean RPP was significantly higher in the prone position compared to the supine position (14.0 vs 3.2 mmHg; p < 0.001). RPPs were significantly higher in the prone position compared to the supine position in all conditions tested. These differences in RPPs between prone and supine PCNL could in part explain the different clinical outcomes, including postoperative fever and stone-free rates.

Echidna Splenule: A Case Study of Continuous Splenogonadal Fusion.

Splenogonadal fusion (SGF) is a rare congenital anomaly of an aberrant accessory spleen-gonad connection. We present a rare case of continuous splenogonadal fusion in a full-term male with a left undescended testis, multiple congenital limb anomalies, and syndromic facies. Diagnostic laparoscopy revealed the "Echidna Splenule," a snake-like intraperitoneal splenule coursing from the spleen along the left paracolic region and engulfing an atrophic intra-abdominal testis preventing spontaneous descent and distally herniating into the left open internal inguinal ring. The atrophic testis and Echidna Splenule were resected. Splenogonadal fusion should be considered in children with left undescended testis and concomitant limb and facial anomalies.

A systematic review of pN0 testicular seminoma: a new clinical entity and future directions.

Retroperitoneal lymph node dissection (RPLND) for testicular seminoma with enlarged retroperitoneal lymph nodes has received increased consideration and exposed a new clinical entity: pN0 disease. Enlarged, nonmetastatic retroperitoneal lymph nodes provide insight into the natural history of seminoma while offering a benchmark for improving the accuracy of staging. The purpose of this systematic review was to report the pN0 rates, describe risk factors associated with it, and discuss emerging research that may reduce its incidence. We performed a systemic review of published literature on PubMed, Embase, Web of Science, as well as oncology meeting abstracts evaluating histology of lymph nodes in patients with testicular seminoma treated primarily with retroperitoneal lymph node dissection. Studies were excluded if histology was not reported. A total of 15 publications and abstracts were included. Although study designs were heterogeneous, there was a minimal risk of bias. Overall, the reported pN0 rates were 0% to 22%. In prospective clinical trials it was 9% to 16%. The presence of pN0 was associated with preoperative smaller lymph nodes, a solitary enlarged lymph node, or negative serum miRNA-371. The incidence of pN0 seminoma is concerning as it points to a potential historical overtreatment; however, it also represents an important inflection for testicular cancer research as quantifiable improvements in clinical staging will translate to clear benefits to patients.

Which Laser System Is Optimal for Cystolithotripsy of Large Bladder Calculi?

Introduction and Objective: A variety of laser sources are available to treat bladder stones. The aim of this study was to compare time and cost efficiency of the thulium fiber laser (TFL) to four holmium lasers (HLs) with different powers or technologies, including MOSES™ during simulated cystolithotripsy. Materials and Methods: In a benchtop simulation of laser cystolithotripsy, 25 identical 4-cm BegoStones (calcium oxalate monohydrate consistency) were placed on a grid within a 3D-printed bladder model. Lasers were operated at maximal energy, using a 550 µm fiber. Lasers compared were as follows: 60 W TFL, 120 W HL with MOSES, and conventional 120, 100, and 30 W HLs. Five trials were performed for each laser with endpoints of laser time, total time, number of fiber strippings, and total energy. Cost-effectiveness was modeled using laser purchase price, fiber, and operating room (OR) time cost. ANOVA with Tukey's B post hoc was performed to compare outcomes. Spearman's test was used to assess correlation between laser power and procedure time. Results: The laser and total operating times were significantly different between the five systems (p < 0.001). The 120 W HL with MOSES was the fastest with 60.9 minutes of laser and 68.3 minutes of procedure times, while the 30 W HL was the slowest with 281.2 minutes of laser and 297.5 minutes of procedure times. The 60 W TFL was faster than the 30 W HL, but slower than the higher power HLs. Higher laser power was associated with shorter procedure time (Rs = -0.98; p = 0.002). When estimating cost per procedure, the MOSES HL was the cheapest, but had the highest purchase cost. The TFL was not cost-effective for large bladder stones compared with the 100 W HL. Conclusions: When treating large bladder stones, total laser power was highly correlated with laser and procedure times and the TFL was limited by its total power. The most cost-effective laser for use will depend on the case volume.

Thulium versus holmium for in situ lower pole laser lithotripsy.

INTRODUCTION: During in situ lower pole laser lithotripsy, the dependent location may result in increased challenge fragmenting stones and a risk for stone regrowth if residual fragments remain. The purpose of this study was to compare the thulium fiber laser (TFL) with the holmium laser (HL) for in situ lower pole lithotripsy. MATERIALS AND METHODS: In a 3D printed kidney benchtop model, sixty 1 cm BegoStones were placed in the lower pole and fragmented in situ until fragments passed through a 2 x 2 mm mesh. Laser lithotripsy was performed using twelve energy, frequency and fiber size combinations and residual fragments were compared. In addition, laser fiber diameters and subsequent ureteroscope deflections and flow rates were compared between fibers. RESULTS: The TFL resulted in decreased residual fragments compared to the HL (11% vs. 17%, p < 0.001) and the three settings with least residual fragments were all TFL. Compared to the 150 µm TFL (265° deflection), there was a loss of 9° and 34° in the 200 µm TFL and 272 µm HL fibers, respectively. The measured fiber sizes were greater than manufacturer specified fiber size in every instance. Irrigation rates inversely correlated with fiber size. CONCLUSION: The TFL resulted in 35% less residual stone fragments, up to 34° additional deflection, and an increased irrigation rate when compared to the HL. Optimal fragmentation settings are identified to further improve lower pole lithotripsy. The combination of reduced residual fragments, improved deflection, and better flow rates make the TFL advantageous for in situ lower pole lithotripsy.