Illumination matters Part II: advanced comparative analysis of flexible ureteroscopes in a kidney model by PEARLS.

PURPOSE: The aim of the study was to evaluate illumination properties in an in-vitro kidney calyx model in saline. DESIGN AND METHODS: We evaluated a series of contemporary flexible ureteroscopes including the Storz Flex-Xc and Flex-X2s, Olympus V3 and P7, Pusen 7.5F and 9.2F, as well as OTU WiScope using a 3D-printed closed pink kidney calyx model, submerged in saline. A spectrometer was used for illuminance and color temperature measurements at different openings located at center (direct light), 45° (direct and indirect light) and 90°(indirect light) to the axis of the scope. RESULTS: Maximum illuminance was at the center opening for all scopes (range: 284 to 12,058 lx at 50% brightness and 454 to 11,871 lx at 100% brightness settings). The scope with the highest center illuminance (Flex-Xc) was 26 times superior to the scope with the lowest illuminance (Pusen 7.5Fr) at 100% brightness setting. For each scope, there was a peripheral illuminance drop ranging from - 43 to - 92% at 50% brightness and - 43% to - 88% at 100% brightness settings, respectively (all p < 0.01). Highest drop was for the P7 and the Pusen 9.2F. All scopes had illuminance skew, except the V3. All scopes had a warm color temperature. CONCLUSION: Illumination properties vary between ureteroscopes in an enclosed cavity in saline, and differs at center vs 45° and 90° positions within scopes. Peripheral illuminance drop can be as high as - 92%, which is undesirable. This may affect the choice of ureteroscope and light brightness settings used in surgery by urologists.

Pulsed Thulium:YAG laser - What is the lithotripsy ablation efficiency for stone dust from human urinary stones? Results from an in vitro PEARLS study.

BACKGROUND: The novel pulsed thulium:yttrium-aluminum-garnet (p-Tm:YAG) laser was recently introduced. Current studies present promising p-Tm:YAG ablation efficiency, although all are based on non-human stone models or with unknown stone composition. The present study aimed to evaluate p-Tm:YAG ablation efficiency for stone dust from human urinary stones of known compositions. METHODS: Calcium oxalate monohydrate (COM) and uric acid (UA) stones were subjected to lithotripsy in vitro using a p-Tm:YAG laser generator (Thulio®, Dornier MedTech GmbH, Germany). 200 J was applied at 0.1 J × 100 Hz, 0.4 J × 25 Hz or 2.0 J × 5 Hz (average 10W). Ablated stone dust mass was calculated from weight difference between pre-lithotripsy stone and post-lithotripsy fragments > 250 µm. Estimated ablated volume was calculated using prior known stone densities (COM: 2.04 mg/mm3, UA: 1.55 mg/mm3). RESULTS: Mean ablation mass efficiency was 0.04, 0.06, 0.07 mg/J (COM) and 0.04, 0.05, 0.06 mg/J (UA) for each laser setting, respectively. This translated to 0.021, 0.029, 0.034 mm3/J (COM) and 0.026, 0.030, 0.039 mm3/J (UA). Mean energy consumption was 26, 18, 17 J/mg (COM) and 32, 23, 17 J/mg (UA). This translated to 53, 37, 34 J/mm3 (COM) and 50, 36, 26 J/mm3 (UA). There were no statistically significant differences for laser settings or stone types (all p > 0.05). CONCLUSION: To our knowledge, this is the first study showing ablation efficiency of the p-Tm:YAG laser for stone dust from human urinary stones of known compositions. The p-Tm:YAG seems to ablate COM and UA equally well, with no statistically significant differences between differing laser settings.

Can the introduction of single-use flexible ureteroscopes increase the longevity of reusable flexible ureteroscopes at a high volume centre?

OBJECTIVES: To assess whether the introduction of single use flexibles ureteroscopes (su-fURS) at our high-volume centre had an advantageous impact on the turn-over and breakage rates of reusable fURS (re-fURS). METHODS: We analysed re-fURS number of usages and breakages at our centre between February 2015 and December 2018. We recorded the number of usages for analysed scope between the first usage until a breakage requiring reconditioning. Usage count was restarted following each reconditioning episode. Since su-fURS (Lithovue, Boston Scientific, USA) were introduced at our center in September 2016, we had the chance to compare different re-fURS life cycles according to both su-fURS availability and usage intensity (i.e., number of su-fURS used during each re-fURS life cycle). We then explored the relationship between su-fURS usage intensity and reusable scope survival (i.e., number of utilizations before any breakage requiring reconditioning) using locally weighted scatterplot smoothing (LOWESS) approach. RESULTS: Five different re-fURSs were employed at our centre, for a total of 1820 usages and 40 breakages requiring reconditioning. The overall mean (SD) number of usages before breaking was 40 (22). After su-fURS introduction, mean (SD) re-fURS number of usages increased from 35 (22) to 49 (20), (+ 40%, p = 0.02). The relationship between su-fURS usage intensity and reusable scopes survival showed a linear survival increase after 10 or more su-fURS scopes were used per life cycle. CONCLUSIONS: The life cycle of re-fURS increased by 40% after the introduction of su-fURS. Ten or more used su-fURS per life cycle were associated with increased re-fURS survival.

Treatment Options for Calyceal Diverticula.

PURPOSE OF REVIEW: Calyceal diverticula are rare entities that can pose a significant challenge when it comes to their management. We analyse and summarise the literature with a focus on recent advances in the management of calyceal diverticula and discuss the advantages and disadvantages of each surgical technique. RECENT FINDINGS: The identification of calyceal diverticula requires a certain level of suspicion and contrast-enhanced imaging. Conventional techniques of imaging the renal collecting system such as the classic intravenous urography are now superseded by the ease of access to contrast-enhanced CT imaging. Conventional surgical techniques for managing calyceal diverticula are not being superseded by new techniques but rather being progressively enhanced and improved through the amelioration of existing technology. Debate still exists over the best treatment approach for the management of symptomatic calyceal diverticula, the choice of which still very much depends on the location and anatomy of the diverticulum itself. The most significant advance in the management of calyceal diverticula and indeed stones, in general, seems to be the progressive miniaturisation of percutaneous nephrolithotomy (PCNL) equipment allowing effective treatment with a reduction in associated risks of conventional PCNL. The increasing accessibility of robotics has a role to play in the management of this condition but is not likely surpass flexible ureteroscopic (fURS) or percutaneous approaches. The future of surgical management for this condition lies in striking a balance between treatment efficacy and invasiveness. More recent identification of metabolic disturbances in patients with calyceal diverticular stones may provide further insights into the underlying pathology of this condition and is likely to play a role in future research of diverticular stones.

High prevalence of osteoporosis in patients with chronic pancreatitis: a systematic review and meta-analysis.

BACKGROUND & AIMS: Patients with chronic pancreatitis may be at high risk for osteoporosis and osteopenia. We performed a systematic review and meta-analysis to determine the prevalence of osteoporosis and osteopenia in patients with chronic pancreatitis. METHODS: Articles were identified from MEDLINE, EMBASE, and SCOPUS databases (through October 2012) and a manual search of the literature. The primary outcome measure was bone density, measured by dual-energy X-ray absorptiometry (T-score or Z-score). When available, data on the prevalence of osteopenia, bone mineral density, and bone mineral content also were recorded. RESULTS: Ten studies including 513 patients were eligible for inclusion. Based on a random-effects model, the pooled prevalence rate for osteoporosis among patients with chronic pancreatitis was 23.4% (95% confidence interval, 16.6-32.0). The pooled prevalence for osteopenia was 39.8% (95% confidence interval, 29.1-51.6). The pooled prevalence rate for either osteoporosis or osteopenia was 65% (95% confidence interval, 54.7-74.0). CONCLUSIONS: Based on meta-analysis, almost 1 of 4 patients with chronic pancreatitis have osteoporosis, and almost two-thirds of patients have either osteoporosis or osteopenia. Osteoporosis and osteopenia are underappreciated sources of morbidity in patients with chronic pancreatitis. Bone health management guidelines are urgently required in patients with chronic pancreatitis.

Pseudo-Renal Failure in the Context of Traumatic Bladder Rupture.

The bladder is both an intraperitoneal and extraperitoneal structure. Its anatomical position increases its risk of rupture. The resultant urine leak or extravasation can be intraperitoneal, extraperitoneal, or even both-with the former leading to more sinister outcomes. Intraperitoneal bladder rupture can lead to urinary ascites which along with anuria and abdominal pain, can present with an apparent abrupt decline in renal function as the creatinine-rich products diffuse across the peritoneal membrane. Glomerular filtration rate, a measure of kidney function is related to the levels of serum creatinine. Clinicians can therefore misdiagnose their patient with acute kidney injury when the serum creatinine is elevated as a consequence of urine being present in the peritoneal space.  This is a case report of a 62-year-old male with pseudo-renal failure following intraperitoneal bladder rupture after a fall face-forwards three hours previously. The fall was due to icy conditions outside and no preceding symptoms were reported. He presented to the Accident and Emergency department with abdominal pain and no other positive symptoms. The patient had a good World Health Organisation (WHO) performance status with a background of hypertension, diabetes, and hypercholesterolemia. The bedside examination of the patient revealed a distended, abdomen with peritonitis. There were no signs of urogenital trauma. Blood testing revealed a low estimated glomerular filtration rate (eGFR) and raised creatinine (eGFR of 7 millilitres/minute and creatinine of 658 micromoles/litre). Computerised tomography examination of the abdomen and pelvis (CTAP) revealed free fluid within the peritoneal cavity and an irregular bladder wall. A CT cystogram and consultation with urology led to the diagnosis of intraperitoneal bladder rupture. The patient's renal function from an initial set of blood tests was reduced. This was not a true impairment in renal function but rather a complication secondary to extravasation of urine in the intraperitoneal space, ie., pseudo renal failure. This supposed impairment in renal function had numerous implications. It affected the choice of antibiotics; amoxicillin and gentamicin were given at a reduced dose due to the patient's renal function and the patient was prepared for operation theatre. The patient's blood creatinine was falsely elevated at 658 micromoles/litre due to the diffusion of creatinine from the free urine in the peritoneal space into the blood. This painted a false image of renal failure and protracted the clinical decision-making process. Relatively simple measures like an ascitic tap could have helped to differentiate this from a true acute kidney injury and could have resulted in quicker and more effective treatment of this patient.  The patient went on to have bladder repair under urology. His follow-up cystogram four weeks post-operation did not show any leak.

Association of One-Step Nucleic Acid Amplification Detected Micrometastases with Tumour Biology and Adjuvant Chemotherapy.

One-step nucleic acid amplification (OSNA) is an intraoperative technique with a high sensitivity and specificity for sentinel node assessment. The aim of this study was to assess the impact of OSNA on micrometastases detection rates and use of adjuvant chemotherapy. A retrospective review of patients with sentinel node micrometastases over a five-year period was carried out and a comparison of micrometastases detection using OSNA and H&E techniques was made. Out of 1285 patients who underwent sentinel node (SLN) biopsy, 76 patients had micrometastases. Using H&E staining, 36 patients were detected with SLN micrometastases (9/year) in contrast to 40 patients in the OSNA year (40/year) (p < 0.0001), demonstrating a fourfold increase with the use of OSNA. In the OSNA group, there was also a proportional increase in Grade III, triple-negative, ER-negative, and HER-2-positive tumours being diagnosed with micrometastases. Also on interactive PREDICT tool, the number of patients with a predicted 10-year survival benefit of more than 3% with adjuvant chemotherapy increased from 52 to 70 percent. OSNA has resulted in an increased detection rate of micrometastases especially in patients with aggressive tumour biology. This increased the number of patients who had a predicted survival benefit from adjuvant chemotherapy.

Fistula formation between the external iliac artery and ileal conduit following a radical cystoprostatectomy: a rare complication with prewarning signs of haemorrhage.

A 76-year-old man was admitted with bleeding per-urostomy following a collapse at home. Three weeks prior to the admission, he had undergone a radical cystoprostatectomy and formation of ileal-conduit for an extensive bladder carcinoma. A CT angiogram revealed a possible small source of bleeding within the ileal-conduit itself, which settled with conservative management. However, prior to discharge he developed profuse fresh bleeding from the urostomy, which could not be controlled. The patient underwent an emergency endoscopy of the conduit and laparotomy, which revealed a fistula between the right external iliac artery and the proximal end of the ileal-conduit. The right iliac artery was ligated and an emergency left-to-right femoral-femoral crossover bypass was performed. The right ureter was stented and rediverted through the ileal-conduit and the left ureter was stented at a later date. He unfortunately had a stormy postoperative recovery with further episodes of per-urostomy bleeding and no identified source.

The prevalence of malnutrition and fat-soluble vitamin deficiencies in chronic pancreatitis.

BACKGROUND: Patients with chronic pancreatitis are at risk of malnutrition and nutrient deficiency due to malabsorption, pain, and poor diet. We sought to examine fat-soluble vitamin levels and malnutrition parameters in patients with chronic pancreatitis. MATERIALS AND METHODS: In a prospective controlled cohort study, 128 subjects (62 chronic pancreatitis patients and 66 age-/sex-matched controls) were recruited. Body mass index (BMI), handgrip strength (measure of functional capacity), fat stores (triceps skin fold), muscle stores (mid-arm muscle circumference), exocrine function, and serum levels of fat-soluble vitamins (A, D, E) were measured. RESULTS: Half of patients in the chronic pancreatitis group were overweight or obese, although the mean BMI was lower in patients than in controls (P = .007). Handgrip strength (P = .048), fat stores (P = .000), and muscle stores (P = .001) were lower in patients than in controls. Of the patients, 14.5% and 24.2% were deficient in vitamins A and E, respectively. Nineteen percent of patients had excess serum vitamin A levels. CONCLUSIONS: Despite the prevalence of overweight and obesity, patients had lower muscle stores, strength, and abnormal vitamin levels. Detailed nutrition assessment including anthropometry and vitamin status is warranted in chronic pancreatitis.

Assessing appropriateness of parenteral nutrition usage in an acute hospital.

BACKGROUND: Although parenteral nutrition (PN) has become an integral component of patient care, the risks and costs associated with this therapy must be weighed against the benefits. The Department of Nutrition and Dietetics at our tertiary referral, university-affiliated hospital has audited the use of enteral nutrition and PN based on criteria devised from guidelines developed by the American Society for Parenteral and Enteral Nutrition (A.S.P.E.N.). We aimed to examine the use of PN over time and in particular to investigate the appropriate and inappropriate use of this feeding method. MATERIALS AND METHODS: Each patient referred for PN was assessed by a dietitian and need for PN evaluated. The appropriateness of the PN was categorized according to predefined criteria. RESULTS: A total of 1191 patients had 1409 episodes of PN during the study period. According to the predefined criteria, 82% of PN episodes were considered "appropriate." PN was "appropriate but avoidable" in 13% of cases. In 5% of episodes, the commencement of PN was considered "inappropriate." The use of appropriate PN increased significantly over the study period (P = .018). CONCLUSION: Most PN episodes were deemed appropriate. We saw 5% inappropriate usage, which is lower than reported in comparable studies. This study underlines the importance of continuous audit and evaluation of practice to maintain appropriate and evidence-based practice in nutrition support.