Training the resident in percutaneous nephrolithotomy

Objective: From the trainers\u27 perspective percutaneous nephrolithotomy (PCNL) is one of the most challenging endourological procedures. In this review we examine the problems arising when training residents in PCNL, and how to facilitate this process. Methods: The recommendations are derived from discussions and consensus during the First European Urolithiasis Society (EULIS) meeting held in London in September 2011. In addition, we searched Medline for articles identified using the keywords \u27training\u27, \u27percutaneous surgery\u27, \u27renal calculi\u27, \u27PCNL\u27, \u27virtual reality\u27 and \u27simulators\u27. We also assessed the effect of modern technology, including the availability of virtual reality models vs. operating room training, and how international organisations like EULIS and European Urological Association can help. Results: The difficulty of training residents in PCNL is partly due to the complexity of obtaining a safe access to the kidney for lithotripsy. The most common way of obtaining access is guided by imaging only, and usually only fluoroscopic imaging is available. This has the potential for injuring structures from the skin to the renal capsule. Minor vascular injuries are relatively common, although most are self-limiting. Visceral injuries that are particularly important are pleural and less commonly colonic injuries, but they are more complex and often require additional procedures. Conclusions: Teaching the skills is more challenging than performing PCNL. In most urological training programmes it is difficult to incorporate teaching and training skills when performing PCNL. To train an academic stone doctor, proficiency in the safe conduct of PCNL is mandatory

Endoscopic observations as a tool to define underlying pathology in kidney stone formers

PURPOSE: Advancements in endoscopy offer the possibility of inspection of intrarenal anatomy and pathology. The aim of the study was to evaluate renal papillary appearance in kidney stone formers and to correlate papillary findings with stone type and patient metabolic data. MATERIALS AND METHODS: A consecutive cohort of 46 kidney stone formers undergoing retrograde intrarenal surgery was enrolled. During surgery, renal papillae were characterized in the domains of ductal Plugging (DP), surface Pitting, Loss of papillary contour, and Amount of Randall's plaque (RP, PPLA scoring). Stone material was analyzed using micro-CT and infrared spectroscopy, and blood and urine were collected for metabolic evaluation. RESULTS: In all patients, renal papillae had changes in at least one of the domains of the PPLA score. Examining the total population, it was evident that patients with predominantly plugging (DP > 0) all had very low RP scores. There were no significant trends between mean PPLA scores and urinary analytes for the total group. CONCLUSION: Efforts to prevent renal stone formation have so far been insufficient in majority of patients. Digital endoscopy reveals that kidney stone formers have different and distinct papillary morphologies that seem to be linked to specific stone-forming pathways. Since renal papillary abnormalities may be easily identified during endoscopy, this may in the future prove to be an important method for tailoring prevention strategies in kidney stone patients

Effects of Acute Acid Loading on the Risk of Calcium Phosphate and Calcium Oxalate Crystallization in Urine

The aim of this study was to examine the risk of calcium phosphate and calcium oxalate crystallization during acute acid loading under controlled conditions. The effects of acute acid loading on rates of renal excretion of calcium, magnesium, phosphate, citrate, oxalate and urine pH were studied in healthy subjects. The risk of calcium phosphate and calcium oxalate crystallization were evaluated by estimates of the ion activity products of calcium phosphate [AP(CaP)-index] and calcium oxalate [AP(CaOx)-index] according to Tiselius. In addition, the risk of brushite [AP(Bru)-index] crystallization was estimated. An acute acid load administered as ammonium chloride (NH4Cl) produced increased urinary excretion of calcium, phosphate and oxalate, decreased urinary excretion of citrate, and a decrease in urine pH. Consequently, calcium-citrate-ratio in urine increased markedly in response to acid loading. AP(CaP)-index decreased markedly due to a fall in urine pH. AP(Bru)-index decreased slightly and remained low throughout the study. AP(CaOx)-index increased significantly, and acid loading is suggested as a risk factor for calcium oxalate stone formation

Development and characterization of hybrid coconut/glass fibers reinforced low density polyethylene composites for bumper application

The EU's End of Life Vehicles (ELV) regulations are forcing car manufacturers to consider the environmental impact of their production and possibly shift from the use of synthetic materials to the use of agro-based materials. However, poor mechanical properties and certain manufacturing limitations currently limit the use of agro-based materials to non-structural and semi-structural automotive components. This research is focused on a composite of hybrid coconut/glass fiber as reinforcement in recycled low density polyethylene matrix alone to enhance the desired mechanical properties for car bumper as automotive structural components. X-ray fluorescence analysis conducted on coconut fiber showed the presence of silica and alumina materials make coconut fibre a choice one. Morphology analysis was performed using scanning electron microscopy (SEM), which reveals that there are small discontinuities and reasonably uniform distribution of the reinforcement fibers and the reinforced low density polyethylene (RLDPE) binder resulting to better mechanical properties. Physic-chemical properties that directly affect developed composite such as variation of Density, Water Absorption, Tensile Strength, Bending strength, Modulus of rupture, Impact Strength and Hardness Values were investigated for both unhybridized and hybridized developed composite. The study shows the successful development of composites of coconut fiber (CF) hybridized with glass fiber (GF) and reinforced low density polyethylene (RLDPE) binder using a simple molding technique. Hybridized samples (CF-GF/RLDPE) showed higher strength when compared to un-hybridized (CF/RLDPE) composites. Better microstructural bonding exists with 25% and 30% wt CF-GF composite resulting in good mechanical properties for the hybridized composites. The grades of composites obtained in the course of this study are applicable in the production of low strength car bumpers

Identification of early stage and metastatic prostate cancer using electrochemical detection of beta-2-microglobulin in urine samples from patients

Abstract To improve prostate cancer (PCa) diagnosis, it is imperative to identify novel biomarkers and establish effective screening techniques. Here, we introduce electrochemical biosensing of β-2-Microglobulin (β2M) in urine as a potential diagnostic tool for PCa. The immunosensor is composed of a screen-printed graphene electrode coated with anti β2M antibodies. The sensor is capable of detecting the protein directly in urine without any sample pretreatment within 45 min including sample incubation and a lower limit of detection of 204 µg/L. The sensor demonstrated a significant difference in the β2M-creatinine ratio in urine between control and both local- and metastatic PCa (mPCa) (P = 0.0302 and P = 0.0078 respectively), and between local- and mPCa (P = 0.0302). This first example of electrochemical sensing of β2M for the diagnosis of PCa may set the stage for an affordable, on-site screening technique for PCa

Laparoscopic nephrectomy for ex-vivo correction of renal artery aneurism and auto transplant

INTRODUCTION AND OBJECTIVES: Renal artery aneurism are a rare condition, with a prevalence of 0.09% of the population. The outcomes and clinical management of this patients depend on the presence of symptoms and subsequent risk of rupture. Most patients are managed by endovascular techniques, but difficult cases may present a challenge to urologists. METHODS: We present a case of a 35 year old female, history of high blood pressure with the diagnosis of a left renal artery aneurism with a diameter of 27 mm. The patient was evaluated by vascular surgery, was unsuitable for endovascular treatment and was submitted to a laparoscopic left nephrectomy with correction of the aneurism ex-vivo and the kidney was transplanted to the left iliac region. RESULTS: Operative time was 150 minutes and the warm ischemia time was 160 seconds. Blood loss was estimated in 80 mL with a hematocrit drop of 2% post operative. Drainage and vesical catheter were removed at day 2 and 6 post-operative, respectively. Post operative creatinine clearance was comparable to the pre operative (Post - 95 vs. Pre - 98 mL/min/1.73m2) The follow up is 15 months and the patients has a functioning kidney and had a normalization of the blood pressure. CONCLUSIONS: In experienced centers, laparoscopic nephrectomy with subsequent autotransplantion can be a safe and effective option in the management of specific conditions. This case presents a possible way to treat renal artery aneurisms that can’t be managed by endovascular procedures

Consultation on kidney stones, Copenhagen 2019 : lithotripsy in percutaneous nephrolithotomy

Purpose: To evaluate the balance between existing evidence and expert opinions on the safety and efficacy of new technological improvements in lithotripsy techniques for percutaneous nephrolithotomy (PCNL). Methods: A scoping review approach was applied to search literature in Pubmed, Embase, and Web of Science. Consensus by key opinion leaders was reached at a 2-day meeting entitled \u201cConsultation on Kidney Stones: Aspects of Intracorporeal Lithotripsy\u201d held in Copenhagen, Denmark, in September 2019. Results: New-generation dual-mode single-probe lithotripsy devices have shown favourable results compared with use of ballistic or ultrasonic lithotripters only. However, ballistic and ultrasonic lithotripters are also highly effective and safe and have been the backbone of PCNL for many years. Compared with standard PCNL, it seems that mini PCNL is associated with fewer bleeding complications and shorter hospital admissions, but also with longer operating room (OR) time and higher intrarenal pressure. Use of laser lithotripsy combined with suction in mini PCNL is a promising alternative that may improve such PCNL by shortening OR times. Furthermore, supine PCNL is a good alternative, especially in cases with complex renal stones and large proximal ureteric stones; in addition, it facilitates endoscopic combined intrarenal surgery (ECIRS). Conclusion: Recent technological improvements in PCNL techniques are promising, but there is a lack of high-level evidence on safety and efficacy. Different techniques suit different types of stones and patients. The evolution of diverse methods has given urologists the possibility of a personalized stone approach, in other words, the right approach for the right patient