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A percutaneous approach to calyceal diverticular stones allows simultaneous ablation of the diverticular cavity and typically renders patients both stone- and symptom-free. [ABSTRACT FROM AUTHOR]

Michelle Jo Semins,1 Brian R Matlaga21University of Pittsburgh Medical Center, Pittsburgh, PA, USA; 2Johns Hopkins Medical Institutions, Baltimore, MD, USAAbstract: Kidney stones are very common and unfortunately do not spare the pregnant population. Anatomical and pathophysiological changes occur in the pregnant female that alter the risk for development of nephrolithiasis. Acute renal colic during pregnancy is associated with significant potential risks to both mother and fetus. Diagnosis is often challenging because good imaging options without radiation use are limited. Management of diagnosed nephrolithiasis is unique in the pregnant population and requires multi-disciplinary care. Herein, we review the metabolic alterations during pregnancy that may promote kidney stone formation, the complications associated with acute renal colic in the pregnant state, and our proposed diagnostic and management algorithms when dealing with this clinical scenario.Keywords: kidney stones, nephrolithiasis, pregnancy

Purpose: Retrograde intrarenal surgery (RIRS) requires urologists to adopt an awkward body posture for long durations. Few urologists receive training in ergonomics despite the availability of ergonomic best practices utilized by other surgical specialties. We characterize ergonomic practice patterns and rates of musculoskeletal (MSK) pain among urologists performing RIRS. Methods: A web-based survey was distributed through the Endourological Society, the European Association of Urology, and social media. Surgeon anthropometrics and ergonomic factors were compared with ergonomic best practices. Pain was assessed with the Nordic Musculoskeletal Questionnaire (NMQ). Results: Overall, 519 of 526 participants completed the survey (99% completion rate). Ninety-three percent of urologists consider ergonomic factors when performing RIRS to reduce fatigue (68%), increase performance (64%), improve efficiency (59%), and reduce pain (49%). Only 16% received training in ergonomics. Residents/fellows had significantly lower confidence in ergonomic techniques compared with attending surgeons with any career length. Adherence to proper ergonomic positioning for modifiable factors was highly variable. On the NMQ, 12-month rates of RIRS-associated pain in ≥1 body part, pain limiting activities of daily living (ADLs), and pain requiring medical evaluation were 81%, 51%, and 29%, respectively. Annual case volume >150 cases (odds ratio [OR] 0.55 [0.35-0.87]) and higher adherence to proper ergonomic techniques (OR 0.67 [0.46-0.97]) were independently associated with lower odds of pain. Limitations include a predominantly male cohort, which hindered the ability to assess gender disparities in pain and ergonomic preferences. Conclusions: Adherence to ergonomic best practices during RIRS is variable and may explain high rates of MSK pain among urologists. These results underscore the importance of utilizing proper ergonomic techniques and may serve as a framework for establishing ergonomic guidelines for RIRS.

Objective: In recent years, there has been increasing interest in the use of ultrasound guidance for endoscopic and percutaneous procedures. Kidney mockups could be used for training, however, available mockups are normally incompatible with ultrasound imaging. We developed a reproducible method to manufacture an ultrasound-compatible collecting system mockup that can be made at urology laboratories. Methods: Positive and negative molding methods were used. A three-dimensional (3D) digital model of a urinary collecting system and the overlying skin surface were segmented from computed tomography. A containment mold (negative) was made following the shape of the skin surface using 3D printing. A collecting system mold (positive) was also 3D printed, but made of a dissolvable material. The containment mold was filled with a gelatin formula with the collecting system mold submersed in situ within. After the gelatin solidified, a solution was used to dissolve the collecting system mold, but not the gelatin, leaving a cavity with the shape of the collecting system. The gelatin was extracted from the container mockup and the collecting system cavity was filled with water. The mockup was imaged with ultrasound to assess echogenicity and suitability for simulating ultrasound-guided procedures. Results: A clear shape corresponding to the collecting system was observed inside the gel structure. Structural integrity was maintained with no observable manufacturing marks or separation seams. Ultrasound images of the mockup demonstrated clear differentiation at the gelatin/water interface. A mock stone was placed in the collecting system and needle targeted to simulate percutaneous needle access. Conclusion: We developed a simple method to manufacture a personalized mockup of the renal collecting system of a patient that can be used for ultrasound-guided percutaneous needle access. Generic collecting system mockups can be used for training, and patient-specific models can be used to simulate and decide the best access path before a clinical case.

Introduction: We performed a decision analysis model of the cost-effectiveness of observation vs intervention for asymptomatic residual fragments less than 4 mm in diameter following ureteroscopic holmium laser lithotripsy., Methods: Outcomes data from a retrospective analysis evaluating the natural history, complications and reintervention rates of asymptomatic residual stone fragments performed by the EDGE (Endourology Disease Group for Excellence) Research Consortium were used. A decision analysis model was constructed to compare the cost-effectiveness of initial observation of residual fragments to immediate intervention. Cost of observation included emergency room visits, hospitalizations and reinterventions. The cost analysis model extended to 3 years to account for delayed reintervention rates for fragments less than 4 mm. Costs of emergency department visits, readmissions and reinterventions were calculated based on published figures from the literature., Results: Decision analysis modeling demonstrated that when comparing initial observation to immediate reintervention, the cost was $2,183 vs $4,424. The difference in cost was largely driven by the fact that over 3 years, approximately 55% of all patients remained asymptomatic and did not incur additional costs. This represents an approximate annual per patient savings of $747, and $2,241 over 3 years when observation is selected over immediate reintervention., Conclusions: Our decision analysis model demonstrates superior cost-effectiveness for observation over immediate reintervention for asymptomatic residual stones less than 4 mm following ureteroscopic lithotripsy. Based on these findings careful stratification and selection of patients may enable surgeons to improve cost-effectiveness of managing small, asymptomatic residual fragments following ureteroscopic lithotripsy.

Urolithiasis is a significant worldwide source of morbidity, constituting a common urological disease that affects between 10 and 15% of the world population. Recent technological and surgical advances have replaced the need for open surgery with less invasive procedures. The factors which determine the indications for percutaneous nephrolithotomy include stone factors (stone size, stone composition, and stone location), patient factors (habitus and renal anomalies), and failure of other treatment modalities (ESWL and flexible ureteroscopy). The accepted indications for PCNL are stones larger than 20 mm 2 , staghorn and partial staghorn calculi, and stones in patients with chronic kidney disease. The contraindications for PCNL include pregnancy, bleeding disorders, and uncontrolled urinary tract infections. Flexible ureteroscopy can be one of the options for lower pole stones between 1.5 and 2 cm in size. This option should be exercised in cases of difficult lower polar anatomy and ESWL-resistant stones. Flexible ureteroscopy can also be an option for stones located in the diverticular neck or a diverticulum. ESWL is the treatment to be discussed as a option in all patient with renal stones (excluding lower polar stones) between size 10 and 20 mm. In addition, in lower polar stones of size between 10 and 20 mm if the anatomy is favourable, ESWL is the option. In proximal ureteral stones, ESWL should be considered as a option with flexible ureteroscopy Active monitoring has a limited role and can be employed in post-intervention (PCNL or ESWL) residual stones, in addition, asymptomatic patients with no evidence of infection and fragments less than 4 mm can be monitored actively.

Context: Endourologic procedures are very common in daily urologic practice for treatment of benign prostatic obstruction, stone disease, urothelial tumors, or stenosis., Objective: To characterize the complications following endoscopic procedures, to describe their management, and to gather information about their prevention in current urologic practice., Evidence Acquisition: A review of the literature was conducted using PubMed/Medline database to include the most relevant articles on the topic. The search focused on endoscopic approaches for treatment of prostate, bladder, or upper urinary tract disease. Percutaneous approaches and noninvasive extracorporeal techniques were excluded. Complications of endourologic procedures were identified through level 1 evidence, systematic reviews of the literature, or original articles assessing complications as the primary end point. Data about management and prevention of each type of complication were retrieved in a second round using specific keywords., Evidence Synthesis: Complications of endoscopic urologic procedures are specific to each surgical approach. Main complications after prostate surgery include transurethral resection of the prostate syndrome, bleeding and transfusion, acute urinary retention, urinary tract infection, clot retention, postoperative irritative symptoms, ejaculatory dysfunction, urinary incontinence, bladder neck contracture, and urethral stricture. Major complications after transurethral bladder tumor include severe bleeding, transfusion, bladder perforation, and urinary tract infection. The most frequent complications after ureteroscopy are fever and sepsis, bleeding, steinstrasse, and ureteral injury. Overall, the literature is very poor, with no systematic reporting of complications and underuse of classification systems. No clear protocols are available for management of complications, and most are based on studies with low levels of evidence. Good clinical practice recommendations and guidelines give useful support about technical issues, intraoperative safety, and prevention of urinary tract infection. The efficacy of these preventive measures remains poorly investigated., Conclusions: Complications following endoscopic surgery are potentially numerous and vary with patient characteristics, surgical approach, and type of medical device. Improved standardization and quality of publications are warranted to improve knowledge of these issues, which are directly linked to the level of care., Patient Summary: We focused on the potential complications of each endoscopic approach used to treat urologic disease. We described the frequency of these complications and gathered information about how to manage them in the operating theater. We also noted caveats for the literature regarding standardization of reporting and classification systems., (Copyright © 2016 European Association of Urology. Published by Elsevier B.V. All rights reserved.)

Purpose: Encrusted ureteral stents are a challenging endourologic problem. We performed a multi-institutional review of percutaneous nephrolithotomy (PCNL) as primary treatment for encrusted stents., Materials and Methods: We identified 36 patients who underwent PCNL for treatment of an encrusted stent. A retrospective review was performed to compile details of procedures and outcomes for these patients., Results: In 36 patients, 38 renal units underwent PCNL for encrusted ureteral stents. The mean patient age was 47.1 years (±16.7), and the female:male ratio was 15:21. Mean stent indwelling time before removal was 28.2 months (±27.8). The reason for long indwelling time was reported in 25 cases; these reasons included "patient unaware stent needed to be removed" (17 cases), pregnancy (2 cases), other comorbidities (3 cases), and patient incarceration (3 cases). In 3 cases, the stent had become encrusted within 3 months of placement. Mean operative time was 162 minutes (±71). There were no major intraoperative complications, and no patients required blood transfusion. Litholapaxy was required for bladder coil encrustations in 22 cases (58%), and ureteroscopy with lithotripsy was required for encrustation of the ureteral portion of the stent in 13 cases (34.2%). Second look percutaneous procedures were required in 13 cases (34.2%). The stent was removed at the time of PCNL without need for concomitant or delayed ureteroscopy and/or cystolitholapaxy in 8 cases (21%). Ultimately, all stents were removed successfully. Patients were rendered stone free according to radiographs in 24 cases (63%)., Conclusions: In this multicenter review, PCNL is confirmed to be a safe and effective means of addressing the retained and encrusted ureteral stent. PCNL without ureteroscopy or litholapaxy was sufficient in a minority of cases (21%). Adjunctive endourologic modalities are often required, and the surgeon should anticipate the need for concomitant antegrade ureteroscopic laser lithotripsy and/or cystolitholapaxy. Although complete stent removal can be anticipated, residual fragments are not uncommon.

Purpose: We determined the optimal imaging study by which to diagnose and treat pregnant patients with suspected urolithiasis., Materials and Methods: A retrospective, multicenter study was performed to determine the comparative accuracy of imaging modalities used before the surgical management of suspected urolithiasis in pregnant patients. Patients with a clinical suspicion of urolithiasis were evaluated with directed imaging including renal ultrasound alone, renal ultrasound and low dose computerized tomography, or renal ultrasound and magnetic resonance urography. When indicated, patients underwent therapeutic ureteroscopy. The rate of negative ureteroscopy was determined and the positive predictive values of the imaging modalities were calculated., Results: A total of 51 pregnant patients underwent ureteroscopy. The mean age of the cohort was 27 years. Mean gestational age was 24.4 weeks. Of the women 24 (47%) underwent renal ultrasound and low dose computerized tomography, 22 (43%) underwent ultrasound alone, and 5 (10%) underwent renal ultrasound and magnetic resonance urography. Negative ureteroscopy occurred in 7 of the 51 patients (14%). The rate of negative ureteroscopy among patients who underwent renal ultrasound alone, renal ultrasound and low dose computerized tomography, and renal ultrasound and magnetic resonance urography was 23%, 4.2% and 20%, respectively. The positive predictive value of computerized tomography, magnetic resonance and ultrasound was 95.8%, 80% and 77%, respectively., Conclusions: The rate of negative ureteroscopy was 14% among pregnant women undergoing intervention in our series. Of the group treated surgically after imaging with ultrasound alone, 23% had no ureteral stone, resulting in the lowest positive predictive value of the modalities used. Alternative imaging techniques, particularly low dose computerized tomography, offer improved diagnostic information that can optimize management and obviate unnecessary intervention., (Copyright © 2013 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.)

Background and Purpose: The optimal management of renal and ureteral calculi in transplanted kidneys is not well defined. Although larger (>1.5 cm) stone burdens are generally treated with percutaneous nephrolithotomy (PCNL), smaller stones may be reasonably approached with retrograde or antegrade ureteroscopy (URS). We report our multicenter experience with URS for transplant lithiasis., Patients and Methods: URS performed for stone disease within a transplanted kidney were retrospectively identified at three stone-referral centers between 2006 and 2011. Demographic and disease parameters were recorded, as were perioperative and postoperative details., Results: Twelve patients underwent URS for a calculus in a transplant renal unit and/or ureter. For retrograde procedures (7), access to the ureteral orifice was facilitated by the use of a Kumpe catheter; a two-wire (safety and working guidewire) technique was used. For antegrade procedures (5), the ureteroscope was passed into the kidney using a two-wire technique without tract dilation. All stones but one necessitated holmium:yttrium-aluminum-garnet laser lithotripsy with extraction of stone fragments. All patients were stone free on postoperative imaging except for one patient with a 2-mm fragment that was observed. Stone analysis included calcium oxalate (6), calcium phosphate (4), and struvite (1)., Conclusion: Antegrade and retrograde URS are safe and effective treatments for patients with simple stone burdens in a transplanted kidney. Although retrograde access to the ureter can be challenging, specialized techniques and modern endoscope technology facilitate this process. Antegrade URS for small stone burdens can be performed safely and effectively without tract dilation.

Purpose: During pregnancy a ureteral stone and its management may pose risks for the mother and fetus. Definitive ureteroscopic management of an obstructing stone during pregnancy has been increasingly used without a reported increased incidence of urological complications. However, the rate of obstetric complications of ureteroscopy during pregnancy remains undefined., Materials and Methods: Charts of pregnant women who had undergone ureteroscopy at 5 tertiary centers were reviewed. Patient and procedure characteristics were collected. Records were evaluated for the occurrence of obstetric complications in the postoperative period., Results: A total of 46 procedures were performed in 45 patients at 5 institutions. There were 2 obstetric complications (4.3%), including 1 preterm labor managed conservatively and 1 preterm labor resulting in preterm delivery. There was no fetal loss. No statistically significant characteristics were identified differentiating those patients having obstetric complications., Conclusions: Ureteroscopy performed during pregnancy has been previously reported to be urologically safe and effective for addressing ureteral stones. In our multi-institutional series a 4% rate of obstetric complications was observed. Based on this risk a multidisciplinary approach is prudent for the pregnant patient undergoing ureteroscopy., (Copyright © 2012 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.)

Purpose: Shock wave lithotripsy and ureteroscopy are highly effective treatments for urinary lithiasis. While stone size and location are primary determinants of therapy, little is known about other factors associated with treatment. We identified patient, provider and practice setting characteristics associated with the selection of ureteroscopy or shock wave lithotripsy., Materials and Methods: We used the Medicare 5% sample to identify beneficiaries with an incident stone encounter from 1997 to 2007. Within this group we identified beneficiaries undergoing shock wave lithotripsy or ureteroscopy for the management of urinary calculi. Multivariable regression models identified factors associated with the use of ureteroscopy., Results: The cohort comprised 9,358 beneficiaries who underwent an initial procedure. Shock wave lithotripsy was used in 5,208 (56%) beneficiaries while ureteroscopy was used in 4,150 (44%). Female patients were less likely than males to undergo ureteroscopy (OR 0.844, p = 0.006). Providers who more recently completed residency training used ureteroscopy more often (p = 0.023). Provider and facility volume were associated with initial procedure selection. The odds of a second procedure following initial shock wave lithotripsy were 1.54 times those of ureteroscopy (p <0.001)., Conclusions: Nonclinical factors are associated with the use of ureteroscopy or shock wave lithotripsy for initial stone management, which may reflect provider and/or patient preferences or experience. Further investigation is required to understand the impact of these outcomes on quality and cost of care., (Copyright © 2011 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.)

Aim: Precise targeting is essential for adequate treatment of lesions during image-guided therapy. The aim of this study was to compare the performance of two emerging image-guided targeting technologies in a phantom model., Materials and Methods: A computer-assisted navigation system and AcuBot were tested using three operators: an interventional radiologist and two endourologists. Fiducials were placed in an anatomic gelatin phantom and targeted by both systems. The images were reconstructed and analyzed using a specialized software package (Amira; Visage Imaging, Carlsbad, CA). Accuracy was assessed by measuring proximity of the tip of the needle to the fiducial on computed-tomography-guided imaging. Accuracy and time to target were quantified and compared., Results: The mean distance from the desired target for AcuBot was 1.2 mm (range: 0.39-2.82). The mean distance from the desired target for the navigation system was 5.8 mm (range: 1.8-11.9). The AcuBot was significantly more accurate than the navigation system (p < 0.0001). The mean time from target acquisition to needle placement was 37 seconds (range: 15-75) for the AcuBot and 108 seconds (range: 45-315) for the navigation system (p = 0.001)., Conclusion: Emerging technologies hold promise for increased accuracy during percutaneous targeted procedures. Both the AcuBot and the computer-assisted navigation system were accurate and efficient in a phantom targeting model. AcuBot was significantly more accurate, faster, and less user dependent than the navigation system. Further studies in animal and clinical studies are warranted to further advance this promising technology.

Background: Historically, the prostate was evaluated for cancer by simple digital rectal examination, and biopsy to obtain a tissue diagnosis of cancer was performed blindly. The advent of ultrasound technology offered a new way to evaluate the prostate, and biopsy techniques were soon developed to incorporate ultrasound guidance., Methods: The authors review the role of transrectal ultrasound (TRUS) of the prostate and ultrasound-guided biopsy of the prostate in the diagnosis of prostate cancer. These techniques are traced from their origins to the current standards of care, with attention paid to developments and controversies in recent literature., Results: Early experience with TRUS led to the description of "classic" sonographic findings of prostate cancer. To obtain a tissue diagnosis of cancer, these regions were initially targeted in ultrasound-guided biopsies. Concomitant with the development of TRUS, though, was the development of the prostate-specific antigen (PSA) assay. Over the past decade, there has been a profound stage migration due to earlier detection of prostate cancer. Most patients now diagnosed with prostate cancer have no palpable abnormality or specific sonographic findings. In response, ultrasound-guided biopsies have become more systematic, rather than lesion-specific, in nature., Conclusions: TRUS continues to play an important role in the evaluation of the prostate when malignancy is suspected. Although the optimal method of prostate biopsy is controversial, ultrasound is critical in ensuring accurate sampling of the gland.

Enzyme histochemical procedures for both hydrolase and oxidoreductase enzyme activity were applied to cryostat sections of polyglactin 910 suture implant sites. Sutures were implanted either solely in tissue or in a combination of in vitro incubation followed by implantation in vivo for total time periods of seven to 56 days. Suture absorption rates were also measured. It is concluded from the results that neither cellular nor enzyme activity is necessary for the degradation and absorption of polyglactin 910 sutures. This conclusion is based on similar absorption rates for sutures implanted solely in vivo and sutures treated in vitro and then implanted in tissue to give equivalent time spans. There were strong indications, however, that the products of suture hydrolysis are probably metabolized through the oxidative enzyme systems of cells adjacent to the suture. This mechanism of polyglactin 910 suture absorption is quite different from that observed and reported for catgut absorbable sutures.

Transmission electron microscopy was used to study the ultrastructure of cells at the interface with an implanted biodegradable polymer, Polyglactin 910. Various stages of implantation were observed from 1 day to 63 days, when absorption of the polymer was essentially complete. Events occurring at the interface include initial adhesion of macrophages on the implant surface; phagocytosis of wound debris; and subsequent erosion, invasion, and phagocytosis of the polymer by macrophages and giant cells. A vascular perfusion technique for fixation of the polymer sites implanted in soft tissue is also described.

A new anastomotic device is demonstrated that is suitable in microvascular surgery for repairing severed blood vessels and inserting vein grafts. Initial pilot studies indicate a 100% patency rate for vessel anastomosis, and a one-year study produced a 96% success rate. However, histological examination revealed notable vessel deterioration with a rigid device. Therefore, an absorbable anastomotic coupler was developed that demonstrates a high patency rate (92%) in both arteries and veins, with substantial absorption of the device by 70 days. Healing at the anastomotic site was qualitatively similar to that obtained with a sutured anastomosis; there was endothelialization by 14 days and absorption of the device by 70 days.

Studies were designed to demonstrate the need for standardization of shape of samples used as implants to evaluate histotoxicity of polymer materials. Six medical-grade polymers (polypropylene, polyethylene, polyurethane, silicone rubber, poly(vinyl chloride), and Teflon) were extruded as rods with circular-, triangular-, and pentagonal-shaped cross sections, and were implanted in rat gluteal muscles for 14 days. Evaluation of the tissue response was assessed by quantitating cellular lysosomal acid phosphatase enzyme activity by using microspectrophotometry. All triangular-shaped implants showed the highest enzyme activity and cellular response; pentagon shapes showed less, and circular rods showed the lowest activity. The results demonstrate the need for standard sample shape for valid comparative studies of tissue response to implanted polymers.

The rabbit ear chamber provides a unique system for viewing an in vivo environment from outside the body. The plastic chamber, modified for our use, is described. Once surgically implanted into the ear of a Laboratory Lop rabbit, a thin tissue bed which grows between the layers of the chamber can be viewed through the microscope. The absorption of biomaterials placed into the chamber can then be observed as a dynamic process.

In order to further evaluate the role of lasers in microvascular tissue closure, we modified an existing CO2 surgical laser (Xanar XA-20) by adding a partially reflecting mirror to attenuate the beam. This allowed the laser to operate at an output of approximately 100 mW, which was appropriate to achieve microvascular closures. In each of 43 rats, one carotid artery was transected and then anastomosed with standard suture technique with 10 to 12 simple interrupted sutures of size 10-0 Ethilon nylon suture (Ethicon, Inc.). The opposite carotid in each rat was anastomosed by the placement of three stay sutures followed by the application of laser irradiation to the tissue between the stay sutures at 90 to 100 mW, spot size of 0.2 mm, pulse duration 0.2 seconds, approximately 20 to 30 pulses per anastomosis. In vivo test periods were 1 hour, 1 day, 3 days, 7 days, 10 days, 14 days, 28 days, 91 days, and 180 days. All anastomoses were evaluated for patency, and selected samples were utilized for light microscopy, and mechanical testing (intraluminal pressure raised to 300 mmHg). It was determined that similar patency rates and slightly faster time to perform the same procedure could be achieved with the use of the low-powered CO2 laser. However, histologic evidence of significant medial damage raises concern about the long-term risk of a higher aneurysm rate. Vessel damage and the lack of simple intraoperative methods to verify the quality of the laser technique restrict these authors from advocating the clinical introduction of the procedure until further advances are made.(ABSTRACT TRUNCATED AT 250 WORDS)

The hydrolytic enzyme activity associated with the tissue reaction to implanted polyvinyl chloride rods containing graded concentrations of an organotin stabilizer was quantitated by microphotometry of tissue sections. The procedure was more sensitive to the effects of the additive than the usual histologic evaluation. It is considered that this type of approach offers a sensitive and objective index to supplement the more subjective morphologic observations in judging the acute histotoxicity of implants.