David Bayne

Diastolic dysfunction in patients with end-stage liver disease is associated with development of heart failure early after liver transplantation.

Background Liver transplantation (LTx) is a life-saving treatment of end-stage liver disease. Cardiac complications including heart failure (HF) are among the leading causes of death after LTx. The Aim The aim is to identify clinical and echocardiographic predictors of developing HF after LTx. Methods Patients who underwent LTx at the University of Nebraska Medical Center (UNMC) between January 2001 and January 2009 and had echocardiographic study before and within 6 months after transplantation were identified. Patients with coronary artery disease (>70% lesion) were excluded. HF after LTx was defined by clinical signs, symptoms, radiographic evidence of pulmonary congestion, and echocardiographic evidence of left ventricular dysfunction (left ventricle ejection fraction <50%). Results Among 107 patients (presented as mean age [SD], 55 [10] years; male, 70%) who met the inclusion criteria, 26 (24%) patients developed HF after LTx. The pre-LTx left ventricle ejection fraction did not differ between the HF (69 [7]) and the control groups (69 [7] vs. 67 [6], P=0.30). However, pre-LTx elevation of early mitral inflow velocity/mitral annular velocity (P=0.02), increased left atrial volume index (P=0.05), and lower mean arterial pressure (P=0.03) were predictors of HF after LTx in multivariate analysis. Early mitral inflow velocity/mitral annular velocity greater than 10 and left atrial volume index 40 mL/m2 or more were associated with a 3.4-fold (confidence interval, 1.2–9.4; P=0.017) and 2.9-fold (confidence interval, 1.1–7.5; P=0.03) increase in risk of development of HF after LTx, respectively. Conclusions This study suggests that elevated markers of diastolic dysfunction during pre-LTx echocardiographic evaluation are associated with an excess risk of HF and may predict post-LTx survival.

Guidelines of guidelines: a review of urethral stricture evaluation, management, and follow-up

Background Our objective is to report a comparative review of recently released guidelines for the evaluation, management, and follow-up of urethral stricture disease. Methods This is an analysis of the American Urologic Association (AUA) and Société Internationale d’Urologie (SIU) guidelines on urethral stricture. Strength of recommendations is stratified according to letter grade that corresponds to the level of evidence provided by the literature. Results Although few, the discrepancies between the recommendations offered by the two guidelines can be best explained by varying interpretations of the literature and available evidence on urethral strictures. When comparing the AUA guidelines and the SIU guidelines on urethral stricture, there are very few discrepancies. Perhaps the most notable difference is in the use of repeat DVIU or urethral dilation after an initial failed attempt. SIU guidelines state that there are instances where repeat DVIU or urethral dilation can be indicated, and they give a range of time at which stricture recurrence post procedure mandates an urethroplasty (less than 3 to 6 months). The AUA guidelines definitively state that repeat endoscopic procedures should not be offered as an alternative to urethroplasty, and they do not mention time of stricture recurrence as a factor. SIU guidelines allow for management of urethral stricture with indwelling urethral stenting. Conclusions Overall there is a need for more high quality research in the work up, management, and follow up care of urethral stricture.

Determinants of nephrostomy tube dislodgment after percutaneous nephrolithotomy.

BACKGROUND AND PURPOSE Percutaneous nephrolithotomy (PCNL) traditionally necessitates the placement of a nephrostomy tube at the conclusion of the surgical procedure. Although tubeless PCNL has become more popular, patients with complex problems still need traditional nephrostomy tube drainage. The goal of this study was to investigate whether patient body mass index (BMI) impacted inadvertent nephrostomy tube dislodgement. Furthermore, we hoped to determine whether nephrostomy tube type impacted tube dislodgement rates. METHODS A retrospective review between 2005 and 2012 of 475 consecutive PCNL cases was undertaken. Patients were categorized based on the type of nephrostomy tube placed. BMI was examined as a continuous variable. The primary outcome of nephrostomy tube dislodgment was determined based on imaging obtained at the time of PCNL and postoperative hospitalization. Logistic regression analysis was then used to adjust for nephrostomy tube type and BMI. RESULTS Overall, 24 (5.5%) total patients experienced nephrostomy tube dislodgment postoperatively. The mean BMI for patients experiencing nephrostomy tube dislodgment was 39.7 vs 30.9 for those without tube dislodgment (P<0.0001; 95% confidence interval [CI] 4.6 to 12.9). Using logistic regression and adjusting for the use tube type, BMI was an independent predictor of tube dislodgement (P<0.001). For each unit of increase in BMI, the likelihood of tube dislodgment increased by 6% (1.06). After adjusting for BMI, however, nephrostomy tube type was not found to be an independent predictor of nephrostomy tube dislodgment. CONCLUSIONS Nephrostomy tube type did not influence nephrostomy tube dislodgment rates. As a patients BMI increased, the likelihood of tube dislodgment increased in a directly proportionate fashion. This is possibly because of the nephrostomy tube being fixed directly to the mobile skin associated with their fat pannus. Although the nephrostomy tube type itself did not affect tube dislodgment rates, a redesigned nephrostomy tube or fixation device should take into account the above findings related to obese patients to reduce the likelihood of nephrostomy tube dislodgment.

Smart watch RSSI localization and refinement for behavioral classification using laser-SLAM for mapping and fingerprinting.

As a first step toward building a smart home behavioral monitoring system capable of classifying a wide variety of human behavior, a wireless sensor network (WSN) system is presented for RSSI localization. The low-cost, non-intrusive system uses a smart watch worn by the user to broadcast data to the WSN, where the strength of the radio signal is evaluated at each WSN node to localize the user. A method is presented that uses simultaneous localization and mapping (SLAM) for system calibration, providing automated fingerprinting associating the radio signal strength patterns to the users location within the living space. To improve the accuracy of localization, a novel refinement technique is introduced that takes into account typical movement patterns of people within their homes. Experimental results demonstrate that the system is capable of providing accurate localization results in a typical living space.

Ultrasound for Intraoperative Confirmation of Antegrade Ureteral Stent Placement During Laparoscopic Pyeloplasty

OBJECTIVE To describe our ultrasound technique for confirming intraoperative, antegrade-placed ureteral stent position during laparoscopic pyeloplasty. BACKGROUND Disadvantages of retrograde stent placement include the need to reposition the patient into and out of the lithotomy position. Antegrade stent placement can reduce procedure time but requires confirming appropriate distal placement into the bladder with cystoscopy, percutaneous drain placement, or instillation of methylthioninium chloride or indigo carmine. MATERIALS AND METHODS A 3-way 20-French Foley catheter is placed after induction with general anesthesia. Laparoscopic transperitoneal dismembered pyeloplasty is performed. Intraoperatively, the bladder is filled retrograde with 300ccs normal saline. After completing the posterior suture line of the ureteral anastomosis, a 4.8-French, 26-cm ureteral stent is placed antegrade down the ureter using a 5-French exchange catheter and guidewire. The stent is passed over the guidewire into the bladder. The proximal curl is then placed into the renal pelvis and the anastomosis is completed. Without patient repositioning, an intraoperative bladder ultrasound is performed to identify the distal stent curl within the bladder lumen. RESULTS This technique demonstrated that ultrasound can guide antegrade stent placement in adult, laparoscopic ureteral surgery. It eliminated the need for intraoperative repositioning of the patient for intraoperative cystoscopy to confirm stent placement and was performed successfully during 8 laparoscopic pyeloplasty cases without failure. Ultrasound is likely more sensitive compared with looking for the presence of vesicoureteral reflux after stent placement, prevents stent malposition, and avoids the use of intravesical dyes that upon reflux can stain tissues and obscure surgical planes. CONCLUSION Here we demonstrate successful use of intraoperative ultrasound to confirm appropriate distal stent positioning in the bladder of an adult patient following antegrade stent placement for laparoscopic dismembered pyeloplasty. To our knowledge, this has been described in pediatrics, but never in adult patients.

Increasing Body Mass Index Steepens the Learning Curve for Ultrasound-guided Percutaneous Nephrolithotomy

OBJECTIVE To define how the learning curve for success in ultrasound-guided percutaneous nephrolithotomy (PCNL) is impacted by body mass index (BMI). Previous research has shown ultrasound-guided PCNL to be an effective method of nephrolithiasis treatment comparable to fluoroscopy-guided PCNL. A common concern for the ultrasound-guided approach is potential imaging difficulty in the obese patient population. METHODS A prospective cohort study of consecutive patients undergoing PCNL with ultrasound guidance for renal tract access was performed. Clinical data collected included success in gaining renal access with ultrasound guidance, patient BMI, and clinical outcomes over time. Nonparametric LOWESS regression modeling was performed in R using locally weighted scatterplot smoother (R version 3.3.3) for gradations of patients by BMI group (<30, 30-40, and >40). RESULTS A total of 150 cases were examined. Case number and BMI were evaluated as continuous variables. Multivariate logistic regression revealed that BMI (P = .010; OR 0.93) and case number (P<.001; OR 1.03) were significantly correlated with ultrasound success. Sex, age, hydronephrosis, stone type, puncture location, and stone size did not influence success at obtaining ultrasound-only access in a statistically significant fashion. LOWESS regression modeling of the relationship between case number and renal access success depicts that the curve representative of the BMI >40 group is downward and right-shifted relative to the other two groups. CONCLUSION The learning curve for successful ultrasound-guided PCNL is impacted by patients BMI as well as case number. Increasing BMI makes access more challenging when performing ultrasound-guided PCNL.

Lower genitourinary tract trauma

Lower genitourinary tract trauma comprises a substantial portion of the trauma burden in the USA. Some key trends and findings are described. Mortality is relatively high in patients with bladder trauma due to associated injuries. Urethral injuries should be suspected in patients presenting with the triad of blood at the urethral meatus, suprapubic fullness indicative of a full bladder, and urinary retention. Urethral injury is common in penetrating penile trauma, and stab wounds to the penis are more likely to involve the urethra than gunshot wounds. Penile fracture is largely a clinical diagnosis and suspicion of fracture requires urgent surgical exploration. Zipper injuries are the most common cause of presentation to the emergency department for penile trauma in adults. Toilet seat injuries are the leading cause of penile pediatric trauma presenting to the emergency department. In the setting of testicular trauma, rates of testicular salvage are excellent when exploration is prompt. Trauma in the form of animal or human bites requires treatment with broad-spectrum antibiotics in addition to repair of the injury. Military trauma has seen an increase in explosive injuries to the lower urinary tracts due to evolution of warfare tactics. Increasing awareness of presentation and context of lower genitourinary tract trauma can reduce delay of diagnosis and morbidity associated with such injuries.

Significant differences in struvite and cystine stone frequency seen among Chinese nephrolithiasis patients living in North America compared to those living in China

Background Interracial disparities in nephrolithiasis prevalence have been reported, but the interplay between genetics and the environment for urinary stone disease risk factors is poorly understood. To examine how environment may alter genetic predisposition for stone formation, we established the International Chinese Consortium on Nephrolithiasis (ICCON) as a multi-institutional collaboration to examine patterns of nephrolithiasis presentation between Chinese patients living in different countries. Methods Chinese patients undergoing percutaneous nephrolithotomy (PCNL) at six participating institutions in China and North America over 4 years were reviewed retrospectively. Patient demographics and clinical data were compared between Chinese patients living in China and North America. Results A total of 806 patients were included, encompassing 721 Chinese patients living in China and 85 living in North America. Nephrolithiasis patients living in China were more likely to be male (67% vs. 56%, P=0.02), present at a younger age (48.6±15.0 vs. 55.0±13.0 years, P<0.01), and have a lower BMI (24.6±4.0 vs. 25.9±5.7, P=0.04) but were less likely to form struvite stones (5.5% vs. 14.1%, P<0.01). No cystine stone patients were seen in North American Chinese patients, whereas 1.8% of nephrolithiasis patients living in China presented with cystine stones. Similar rates of calcium-based and uric acid calculi as well as urinary pH were seen among both groups. Conclusions Significant differences exist between Chinese nephrolithiasis patients living in China compared to those living in North America, highlighting the importance of environmental factors in addition to genetics in modulating risk for urinary stone disease.

MP17-05 PROSPECTIVE CLINICAL TRIAL EVALUATING ANTEGRADE NEPHROSTOGRAPHY TO ASSESS URINE FLOW AFTER PERCUTANEOUS NEPHROLITHOTOMY

INTRODUCTION AND OBJECTIVES: Percutaneous nephrolithotomy (PNL) remains an effective treatment for patients with a large stone burden. When a nephrostomy tube (NT) is left in place postoperatively, antegrade flow of urine is often confirmed with antegrade nephrostography (ANG) as edema from a chronically obstructing stone can resolve in variable amounts of time. Alternatively, antegrade flow can be estimated by injecting methylene blue dye into the NT or performing a NT capping trial. We compared the methylene blue dye test and capping trial against ANG to assess antegrade urine flow. METHODS: Consecutive patients undergoing PNL at 2 hospitals were prospectively enrolled between July and October, 2014. A cap was placed on the NT on the morning of postoperative day 1 (POD1). Capping trial failure was defined as need to uncap NT for any reason including increased pain or fever. 2 hours after capping, 7cc of methylene blue was injected into the NT and the tube recapped. Positive test was defined as the presence of blue per urethral Foley. Later that afternoon, ANG was performed to radiographically document antegrade urine flow. Sensitivity, specificity, positive (PPV) and negative predictive values (NPV) were calculated comparing capping and methylene blue tests against ANG. RESULTS: 34 subjects underwent PNL. 55.9% were left sided and 73.5% were lower pole punctures (mean age 54.9 13.9 years; mean BMI 31.7 12.7kg/m2; mean stone size 2.86 1.42cm). Capping trial was successful in 86.7% of patients. Compared to ANG, it had a sensitivity of 94.4% (CI 83.9-100%), specificity 25.0% (CI 0.5-49.5%), PPV 65.4% (47.1-83.7%), and NPV 75.0% (CI 32.6-100%) to predict antegrade urine flow. The methylene blue test was positive in 41.4% of patients. Compared to ANG, it had a sensitivity of 52.9% (CI 29.2-76.7%), specificity 75.0% (CI 50.5-99.5%), PPV 75.0% (CI 50.5-99.5%), and NPV 52.9% (CI 29.2-76.7%) to predict antegrade urine flow. CONCLUSIONS: Compared to ANG, a capping trial and methylene blue test are 94% and 53% sensitive and 25% and 75% specific respectively for confirming antegrade urine flow following PNL. In clinical practice, these tests may potentially be used in combination to obviate the need for ANG, which can be redundant and timeconsuming.

Inherent difficulties of measuring the burden of surgical disease in resource-poor settings: reply.

We thank Mr. Leeds for his letter and applaud his noble efforts in addressing urologic surgical needs in Haiti. Similar to the reported experience of the Emory Medishare group, we too found both a demonstrated need for and a substantial lack of urologic specialists throughout the Central Plateau. The Emory group correctly highlights many of the gaps in quality care that exist not only in Central Haiti but in resource-poor regions of lowand middle-income countries (LMICs) around the world. The capacity for Haitain providers to meet the regionally specific surgical demands of their own community is something on which we should all be acutely focused in our present and future work. We appreciate the critical insight with which Mr. Leeds addressed our article, and acknowledge, as we did in the article itself, that our study has limitations to consider before translating our results into practice. We do not purport that our data should be the ultimate guide to policymaking. Indeed, our work was necessarily and intentionally limited in time and scope. We simply sought to capture objectively the urologic experience at several Partners In Health/Zanmi Lasante (PIH/ZL) facilities over a defined period of time. We relied on available operative logs at each of the hospitals we assessed. Mr. Leeds’ own reports are more limited in both time and geography compared to our work. As such, they may not be directly comparable to our findings. Our study was and is meant to offer introductory comments in a much longer discussion about the burden of urologic disease in LMICs. For several years now, progress within the global surgical community has focused on the development of collaborative partnerships, both within and across borders, as well as on the demolition of individual silos among participants in health care on the global stage [1, 2]. Rather than the differences that Mr. Leeds and his colleagues highlight in their letter, we believe that our published experience and that of the Emory Medishare group serve to emphasize the fact that we are health care providers united by common problems. In fact, Mr. Leeds himself has correctly championed this crucial need for meaningful and productive cross-institutional collaboration within the global health community [3, 4]. An overfocused attention on experiential differences that do not help promote a common solution can develop into what Dean Julio Frenk has dubbed ‘‘perverse paradoxes’’: false and artificial dichotomies between or within health care communities that can retard meaningful development [5]. As a community, we should be ever wary of promoting these false dichotomies and becoming potential ‘‘victims of our own success.’’ Rather, we should strive to think in an integrated fashion. We recognize that the problem of adequate access to and provision of essential surgical care is larger than any one group or any one study can begin to address in a comprehensive manner. We believe that an integrated and multidisciplinary effort will continue to promote meaningful development in health systems for the world’s poorest populations. M. D. Manganiello (&) Institute of Urology, Lahey Clinic, Burlington, MA 01805, USA e-mail: manganiello1@gmail.com