You have accessJournal of UrologyCME1 May 2022PD02-01 PRENATAL CLOSURE OF MYELOMENINGOCELE IS ASSOCIATED WITH HIGHER RISK FOR EARLY SECONDARY SPINAL CORD TETHERING Hsin-Hsiao Wang, Duncan Morhardt, Benjamin Warf, Lawrence Karlin, Asal Hojjat, Shahram Khoshbin, Erin Mcnamara, Carlos Estrada, and Stuart Bauer Hsin-Hsiao WangHsin-Hsiao Wang More articles by this author , Duncan MorhardtDuncan Morhardt More articles by this author , Benjamin WarfBenjamin Warf More articles by this author , Lawrence KarlinLawrence Karlin More articles by this author , Asal HojjatAsal Hojjat More articles by this author , Shahram KhoshbinShahram Khoshbin More articles by this author , Erin McnamaraErin Mcnamara More articles by this author , Carlos EstradaCarlos Estrada More articles by this author , and Stuart BauerStuart Bauer More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002517.01AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: The long-term impact of prenatal myelomeningocele (MMC) closure on neuro-urologic function is unclear. Urodynamic studies (UDS) often serve as an early indicator of symptomatically acquired spinal cord tethering. We sought to compare the risk for early neuro-urologic deterioration due to spinal cord tethering in children with prenatal versus postnatal MMC repair. METHODS: Children with prenatal MMC closure followed at our institution from 1999 to 2019 were included. Children with postnatally closed MMC were selected as matched controls in 1:3 ratio by sex, neurological level, & follow-up. Primary outcome was defined as time to secondary untethering procedure. Birth year, gender, functional neurological level, UDS & reasons for surgery were assessed. Multivariate cox proportional hazard model was fitted. RESULTS: Our study included 21 with prenatal & 62 with postnatal MMC closure. 12/21 (57%) of the prenatally and 15/62 (24%) of the postnatally closed babies underwent secondary spinal cord surgery (SSCS). Median age for SSCS in those closed prenatal was younger (median 16 [IQR 13-62] months) compared to the postnatal group (median 69 [IQR 35-120] months, p=0.02). Compared to the postnatal MMC group, prenatal MMC closure was significantly associated with need for SSCS (p <0.01, figure 1). When adjusting for birth year, sex, functional neurologic level, prenatal MMC closure remained significantly associated with the need for untethering surgery (HR=4.7(2.5-12.0), p <0.001). Under the same MMC bladder management protocol for both groups, 8/12 (67%) of prenatally closed children requiring secondary untethering surgery had symptomatic UDS changes, with 7/8 (88%) showing improved postoperative UDS parameters. Similarly, 93% (14/15) of postnatally closed children with acquired tethering had UDS changes, with 11/14 (78%) showing improved postoperative UDS. CONCLUSIONS: We found substantially more children with prenatal MMC closure who required SSCS compared to those closed postnatally. In each group, most presented with worsening UDS parameters. Early detection of UDS changes & secondary untethering resulted in neuro-urologic improvement. The cause of this phenomenon is not clear and requires further investigation. Source of Funding: None © 2022 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 207Issue Supplement 5May 2022Page: e35 Advertisement Copyright & Permissions© 2022 by American Urological Association Education and Research, Inc.MetricsAuthor Information Hsin-Hsiao Wang More articles by this author Duncan Morhardt More articles by this author Benjamin Warf More articles by this author Lawrence Karlin More articles by this author Asal Hojjat More articles by this author Shahram Khoshbin More articles by this author Erin Mcnamara More articles by this author Carlos Estrada More articles by this author Stuart Bauer More articles by this author Expand All Advertisement PDF DownloadLoading ...

The urinary bladder is a highly dynamic organ that undergoes large deformations several times per day. Mechanical characteristics of the tissue are crucial in determining the function and dysfunction of the organ. Yet, literature reporting on the mechanical properties of human bladder tissue is scarce and, at times, contradictory. In this study, we focused on mechanically testing tissue from both human and pig bladders using identical protocols to validate the use of pigs as a model for the human bladder. Furthermore, we tested the effect of two treatments on tissue mechanical properties. Namely, elastase to digest elastin fibers, and oxybutynin to reduce smooth muscle cell spasticity. Additionally, mechanical properties based on the anatomical direction of testing were evaluated. We implemented two different material models to aid in the interpretation of the experimental results. We found that human tissue behaves similarly to pig tissue at high deformations (collagen-dominated behavior) while we detected differences between the species at low deformations (amorphous matrix-dominated behavior). Our results also suggest that elastin could play a role in determining the behavior of the fiber network. Finally, we confirmed the anisotropy of the tissue, which reached higher stresses in the transverse direction when compared to the longitudinal direction.

Constructive remodeling of focal esophageal defects with biodegradable acellular grafts relies on the ability of host progenitor cell populations to repopulate implant regions and facilitate growth of de novo functional tissue. Intrinsic molecular mechanisms governing esophageal repair processes following biomaterial-based, surgical reconstruction is largely unknown. In the present study, we utilized mass spectrometry-based quantitative proteomics and in silico pathway evaluations to identify signaling cascades which were significantly activated during neoepithelial formation in a Sprague Dawley rat model of onlay esophagoplasty with acellular silk fibroin scaffolds. Pharmacologic inhibitor and rescue experiments revealed that epithelialization of neotissues is significantly dependent in part on pro-survival stimuli capable of suppressing caspase activity in epithelial progenitors via activation of hepatocyte growth factor receptor (c-MET), tropomyosin receptor kinase A (TrkA), phosphoinositide 3-kinase (PI3K), and protein kinase B (Akt) signaling mechanisms. These data highlight the molecular machinery involved in esophageal epithelial regeneration following surgical repair with acellular implants.

Surgical reconstruction of tubular esophageal defects with autologous gastrointestinal segments is the gold standard treatment to replace damaged or diseased esophageal tissues. Unfortunately, this approach is associated with adverse complications, including dysphagia, donor-site morbidity, and in some cases patient death. Bilayer silk fibroin (BLSF) scaffolds were investigated as alternative, acellular grafts for tubular esophagoplasty in a porcine defect model for 3 months of implantation. Adult Yucatan mini-swine (n = 5) were subjected to esophageal reconstruction with tubular BLSF grafts (2 cm in length) in combination with transient esophageal stenting for 2 months followed by a 1-month period, where the graft site was unstented. All animals receiving BLSF grafts survived and were capable of solid food consumption, however strictures were noted at graft regions in 60% of the experimental cohort between 2 and 3 months postop and required balloon dilation. In addition, fluoroscopic analysis showed peristaltic function in only 1/5 neotissues. Following swine harvest at 3 months, ex vivo tissue bath evaluations revealed that neoconduits exhibited contractile responses to carbachol, electric field stimulation, and KCl, whereas sodium nitroprusside and isoproterenol induced relaxation effects. Histological (Masson's Trichrome) and immunohistochemical analyses of regenerated tissue conduits showed a stratified, squamous epithelium expressing pan-cytokeratins buttressed by a vascularized lamina propria containing a smooth muscle-rich muscularis mucosa surrounded by a muscularis externa. Neuronal density, characterized by the presence of synaptophysin-positive boutons, was significantly lower in neotissues in comparison to nonsurgical controls. BLSF scaffolds represent a promising platform for the repair of tubular esophageal defects, however improvements in scaffold design are needed to reduce the rate of complications and improve the extent of constructive tissue remodeling. Impact statement The search for a superior "off-the-shelf" scaffold capable of repairing tubularesophageal defects as well as overcoming limitations associated with conventional autologous gastrointestinal segments remains elusive. The purpose of this study was to investigate the performance of an acellular, bilayer silk fibroin graft (BLSF) for tubular esophagoplasty in a porcine model. Our results demonstrated that BLSF scaffolds supported the formation of tubular neotissues with innervated, vascularized epithelial and muscular components capable of contractile and relaxation responses. BLSF scaffolds represent a promising platform for esophageal tissue engineering.

OBJECTIVE To evaluate the association of clinical factors on outcomes in patients with spinal cord injury (SCI) undergoing ureteroscopy. Immobility, recurrent urinary tract infection, and lower urinary tract dysfunction contribute to renal stone formation in patients with SCI. Ureteroscopy is a commonly utilized treatment modality; however, surgical complication rates and outcomes have been poorly defined. Evidence guiding safe and effective treatment of stones in this cohort remains scarce. METHODS Records were retrospectively reviewed for patients with SCI who underwent ureteroscopy for kidney stones from 1996 to 2014 at a single institution. Multivariate relationships were evaluated using a general estimating equation model. RESULTS Forty-six patients with SCI underwent a total of 95 ureteroscopic procedures. After treatment, stone-free rate was 17% and 20% with <2-mm fragments. The complication rate was 21%. On multivariate analysis, SCI in cervical (C) levels was associated with higher risk of complications (C3: odds ratio [OR] 3.83, 95% confidence interval [CI] 2.17-6.98; C6: OR 3.83, 95% CI 1.08-13.53). American Spinal Injury Association Scale A classification was associated with a lower probability of stone-free status (OR 0.16, 95% CI 0.03-0.82). Patients averaged 2.2 procedures yet more procedures were associated with lower stone-free status (OR 0.83, 95% CI 0.03-0.32). Chronic obstructive pulmonary disease and bladder management modality were not associated with stone-free status or complications. CONCLUSION In patients with SCI, higher injury level and complete SCI were associated with worse stone clearance and more complications. Stone-free rate was 17%. Overall, flexible ureteroscopy is a relatively safe procedure in this population. Alternative strategies should be considered after failed ureteroscopy. (c) 2018 Elsevier Inc.

INTRODUCTION AND OBJECTIVE Recently there has been interest in a dusting technique for lithotripsy during ureteroscopy (URS) utilizing high-frequency and low-pulse energy (HiFr-LoPE) settings. We assessed a 120-W holmium laser that permits high-frequency (>50 Hz) dusting. MATERIALS AND METHODS Consecutive URS cases performed by a single surgeon using the P120H (Lumenis, San Jose, CA) were reviewed. Lithotripsy was performed using HiFr-LoPE settings (50-80 Hz/0.2-0.5 J [10-40 W]). Residual fragments (RFs) were determined on postoperative radiography, ultrasonography, or CT. Complications were classified using the Clavien-Dindo grade. RESULTS URS was performed on 82 renal units (71 patients). Renal stones constituted the majority (73%), including four partial staghorn stones. Mean stone size and density (HU) were 12.5 mm (SD 8.7; range 5.0-50.0) and 993 (SD 353; range 230-1580), respectively. Ureteral access sheath was used in 15 (21%) patients. Mean total laser energy per case was 5.2 kJ (range 0.1-42.1). Dusting was exclusively performed in 84% of cases. Postoperative stents were placed in 91% (41% string). Zero-fragment and ≤2 mm RF rates were 62.1% and 74.2%, respectively. There were 11 complications (13%) (grade 1 = 5, grade 2 = 6). The emergency department visit rate was 5.6%. There were no hospitalizations or reinterventions. CONCLUSIONS Refinements in laser technology have expanded methods to ablate urinary stones. Outcomes utilizing a dusting technique demonstrated acceptable RF and complication rates. However, not all stones are amenable to dusting, and further study is needed to define the optimal role of this technique during laser lithotripsy.

OBJECTIVE To demonstrate that commercial activity monitoring devices (CAMDs) are practical for monitoring resident sleep while on call. Studies that have directly monitored resident sleep are limited, likely owing to both cost and difficulty in study interpretation. The advent of wearable CAMDs that estimate sleep presents the opportunity to more readily evaluate resident sleep in physically active settings and "home call," a coverage arrangement familiar to urology programs.METHODS Twelve urology residents were outfitted with Fitbit Flex devices during "home call" for a total of 57 (out of 64, or 89%) call or post-call night pairs. Residents were surveyed with the Stanford Sleepiness Scale (SSS), a single-question alertness survey. Time in bed (TIB) was "time to bed to "rise for day." Fitbit accelerometers register activity as follows: (1) not moving; (2) minimal movement or restless; or (3) above threshold for accelerometer to register steps. Total sleep time (TST) was the number of minutes in level 1 activity during TIB. Sleep efficiency (SE) was defined as TST divided by TIB.RESULTS While on call, 10 responding (of 12 available, 83%) residents on average reported TIB as 347 minutes, TST as 165 minutes, and had an SE of 47%. Interestingly, SSS responses did not correlate with sleep parameters. Post-call sleep demonstrated increases in TIB, SE, and TST (+23%, +15%, and +44%, respectively) while sleepiness was reduced by 22%.CONCLUSION We demonstrate that urologic residents can consistently wear CAMDs while on home call. SSS did not correlate with Fitbit-estimated sleep duration. Further study with such devices may enhance sleep deprivation recognition to improve resident sleep. (C) 2017 Elsevier Inc.

You have accessJournal of UrologyStone Disease: Surgical Therapy III1 Apr 2016MP33-06 URETEROSCOPIC STONE TREATMENT OUTCOMES IN SPINAL CORD INJURED PATIENTS Duncan Morhardt, Miriam Hadj-Moussa, J. Stuart Wolf, He Chang, Gary Faerber, William Roberts, John Stoffel, and Ann Pelletier-Cameron Duncan MorhardtDuncan Morhardt More articles by this author , Miriam Hadj-MoussaMiriam Hadj-Moussa More articles by this author , J. Stuart WolfJ. Stuart Wolf More articles by this author , He ChangHe Chang More articles by this author , Gary FaerberGary Faerber More articles by this author , William RobertsWilliam Roberts More articles by this author , John StoffelJohn Stoffel More articles by this author , and Ann Pelletier-CameronAnn Pelletier-Cameron More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2016.02.1363AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Spinal cord injury (SCI) results in immobility, infection, lower urinary tract dysfunction, and changes in body habitus that contribute to stone formation. Surgical positioning issues and the complexity of stone burden require repeated interventions and complications often necessitate intensive care unit admissions. In the era of flexible ureteroscopy, evidence guiding safe and effective treatment in this cohort remains scarce and would be instructive for directing appropriate surgical stone management. METHODS Records from 7000 consecutive stone procedures at the University of Michigan from 1996-2013 were retrospectively reviewed for patients with SCI who underwent ureteroscopy. Patients without stones on post-operative imaging were considered stone free. Bivariate relationships were tested using a generalized estimating equation model. Sample size prevented the ability to adjust for other factors in a multivariable analysis. RESULTS Forty-seven SCI patients underwent a total of 95 ureteroscopic procedures. Based on post-operative CT and KUB imaging, 16% of patients were stone free at 2 months follow-up. On bivariate analysis: cervical injury was associated with higher risk of a complication, but not severity of complication (p<0.0001); sacral injury was associated with stone-free status (p<0.0001), as was post-operative stenting (p=0.018); and there was a trend of more distal SCI with improved stone clearance. Pre-operative fluorourodynamic study parameters were not significantly associated with outcomes. Interestingly, chronic obstructive pulmonary disease (p=0.94) and respiratory comorbidities were not associated with complications. Contractures, use of sheath, stone size (p=0.09), and bladder management modality were not associated with stone free status. Pre-operative positive urine cultures were not associated with statistically increased incidence of sepsis (p=0.51) or complications (p=0.71). CONCLUSIONS In SCI patients, both stone clearance and complications of ureteroscopy were associated with level of injury, with higher levels of injury having less favorable outcomes. © 2016FiguresReferencesRelatedDetails Volume 195Issue 4SApril 2016Page: e438 Advertisement Copyright & Permissions© 2016MetricsAuthor Information Duncan Morhardt More articles by this author Miriam Hadj-Moussa More articles by this author J. Stuart Wolf More articles by this author He Chang More articles by this author Gary Faerber More articles by this author William Roberts More articles by this author John Stoffel More articles by this author Ann Pelletier-Cameron More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Crossed-fused renal ectopy is an uncommon abnormality of the genitourinary tract that results from errors during embryological development. Ureteral herniation represents another rare anatomic event and can often occur from spontaneous, postoperative, and congenital causes (Allam, Johnson, Grewal & Johnson 2015; Pollack, Popky & Blumberg 1975). Here, we discuss the complex clinical course of a patient with crossed-fused renal ectopia who presents with symptoms due to ureteroinguinal herniation and provide a brief overview of the literature. We highlight the clinical considerations in the management of this patient and provide a potential anatomical and embryological explanation for his presentation.

You have accessJournal of UrologyStone Disease: Surgical Therapy V1 Apr 2016MP51-07 FLEXIBLE URETEROSCOPY AND LASER LITHOTRIPSY FOR RENAL STONES USING ‘POP-DUSTING’: COMPARISON OF OUTCOMES BETWEEN TRADITIONAL DUSTING SETTINGS VERSUS ULTRA-HIGH FREQUENCY SETTINGS James Tracey, Galina Gagin, Duncan Morhardt, John Hollingsworth, and Khursid Ghani James TraceyJames Tracey More articles by this author , Galina GaginGalina Gagin More articles by this author , Duncan MorhardtDuncan Morhardt More articles by this author , John HollingsworthJohn Hollingsworth More articles by this author , and Khursid GhaniKhursid Ghani More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2016.02.462AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES The ″dusting″ technique for laser lithotripsy during flexible ureteroscopy (fURS) has become popular with the advent of multi-cavity high power holmium lasers. However the evidence base in this area is limited, especially regarding different laser settings for dusting. We analyzed our outcomes of dusting for renal stones, before and after acquisition of a 120-watt holmium system that can achieve frequencies of up to 80 Hertz (Hz). METHODS We performed a retrospective review of consecutive fURS for renal stones by a single surgeon using a dusting technique over a 14-month period. Dusting, i.e. high frequency and low pulse energy, was used in two groups: Group 1 using 60-100-watt Holmium:YAG systems with settings of 0.2-0.5 Joules (J) x 30-50Hz; Group 2 using a 120-watt system (Pulse 120H, Lumenis Inc, San Jose, CA) using settings of 0.2-0.5J x 30-80Hz, including the technique of ″Pop-dusting″ (0.5J x 80Hz). All cases were recorded in a database and assessed for stone size, Hounsfield unit (HU), use of staged procedures and ureteral access sheaths (UAS). Stone clearance was determined on post-operative radiography, ultrasound or computed tomography. Complications were classified using the Clavien-Dindo Grade.″ RESULTS Dusting for renal stones was performed in 28 patients in Group 1 and 35 patients in Group 2, including a total of 6 patients with partial staghorn stones. The mean stone sizes were 11.1 (Group 1) and 12.2 mm (Group 2) (p=0.41). The mean body mass index was higher in Group 2 (33.3 vs 29.7, p<0.05). There were no differences in HUs (1015 vs 948, p=0.45), or percentage of solitary (71% vs 74%, p=0.58) or lower pole (25% vs 29%, p=0.78) stones between groups 1 and 2, respectively. UAS was used in 32% (Group 1) and 37% (Group 2) of patients, primarily to keep low intra-renal pelvic pressures. There was no difference in mean laser energy used between groups (7.2kJ vs 6.6kJ, p=0.85, Groups 1 and 2, respectively). The zero-fragment and ≤2 mm-fragment rates were 39% vs 66% (p<0.05), and 57% vs 77% (p=0.11) for Groups 1 and 2, respectively. There were no differences in complications (Group 1: Grade 1-2=3 vs Group 2: Grade 1-2=4). Staged procedures were performed less frequently in Group 2 (11% vs 32%, p=0.06). CONCLUSIONS We demonstrated an improvement in complete stone-free rates when using a dusting technique for renal stones with ultra-high frequencies. Our results suggest dusting during fURS is a reasonable alternative to conventional laser lithotripsy strategies or basket retrieval techniques. © 2016FiguresReferencesRelatedDetails Volume 195Issue 4SApril 2016Page: e683 Advertisement Copyright & Permissions© 2016MetricsAuthor Information James Tracey More articles by this author Galina Gagin More articles by this author Duncan Morhardt More articles by this author John Hollingsworth More articles by this author Khursid Ghani More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

You have accessJournal of UrologyStone Disease: Surgical Therapy IV1 Apr 2016PD23-11 STONE DUSTING: OUTCOMES OF URETEROSCOPIC LITHOTRIPSY USING A MULTI-CAVITY HIGH-POWER HOLMIUM LASER James Tracey, Galina Gagin, Duncan Morhardt, John Hollingsworth, and Khurshid Ghani James TraceyJames Tracey More articles by this author , Galina GaginGalina Gagin More articles by this author , Duncan MorhardtDuncan Morhardt More articles by this author , John HollingsworthJohn Hollingsworth More articles by this author , and Khurshid GhaniKhurshid Ghani More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2016.02.1750AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES A popular approach to treating renal stones with ureteroscopy (URS) is laser fragmentation and basket retrieval. Recently, there has been great interest in ′Dusting′ technique in comparison to retrieval. However, critics contend this may be associated with high residual fragment (RF) rates. To better inform this debate we evaluated our experience with dusting using a multi-cavity high-power holmium laser. METHODS We performed a retrospective review of all consecutive URS cases performed by a single surgeon at an academic center utilizing a 120-Watt Holmium:YAG laser (Pulse 120H, Lumenis Inc, San Jose, CA). The 120-Watt has dual lithotripsy modes of ′Dusting′ and ′Fragmentation′. Dusting i.e., high frequency and low pulse energy (HiFr-LoPE), settings of 0.2-0.5 J x 30-80 Hz were utilized. All cases were recorded on a database by a research assistant and assessed for stone size, Hounsfield unit (HU), and use of: staged procedures, ureteral access sheath (UAS) and post-operative stenting. Stone clearance was determined on post-operative radiography (KUB), ultrasound or computed tomography. Complications were classified using the Clavien-Dindo Grade. RESULTS Over an eight month period, URS was performed on 82 renal units (71 patients). Renal stones constituted the majority of cases (73.2%) including four partial staghorn stones. Bilateral URS was performed in five patients, while a further five had staged procedures. The mean stone size and HU were 11.5 mm (SD 5.6; range 4-30) and 1032.9 (range 200-1530), respectively. The maximum cumulative diameter for stones ranged from 5 to 50 mm. UAS was used in 15 patients (21.1%) primarily to keep low intra-renal pelvic pressures. Mean laser energy used was 5.20kJ (range 0.06-42.09). Post-operative stents were used in 91.4% of cases, of which 41.3% were self-extraction strings. Ten patients (14.0%) had complications (Grade 1=5, Grade 2=5). Four of these patients had an emergency department visit, but no readmission. At a mean follow-up of 102 days, the zero-fragment and ≤2 mm residual fragment rates were 67.2% and 80.3%, respectively. CONCLUSIONS In our series we observed acceptable rates of residual fragments and post-operative complications after dusting technique for ureteroscopy. These data would suggest that dusting may be an attractive alternative to basket extraction thereby sparing patients possible morbidity associated with the routine use of ureteral access sheaths. © 2016FiguresReferencesRelatedDetails Volume 195Issue 4SApril 2016Page: e510 Advertisement Copyright & Permissions© 2016MetricsAuthor Information James Tracey More articles by this author Galina Gagin More articles by this author Duncan Morhardt More articles by this author John Hollingsworth More articles by this author Khurshid Ghani More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

You have accessJournal of UrologyUrolithiasis1 Apr 2015V6-12 THE NEW STONE AGE: URETEROSCOPIC STONE “DUSTING” WITH A 120-WATT HOLMIUM LASER Duncan R. Morhardt, James Tracey, J. Stuart Wolf, and Khurshid R. Ghani Duncan R. MorhardtDuncan R. Morhardt More articles by this author , James TraceyJames Tracey More articles by this author , J. Stuart WolfJ. Stuart Wolf More articles by this author , and Khurshid R. GhaniKhurshid R. Ghani More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2015.02.477AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Techniques for laser lithotripsy during ureteroscopy (URS) have evolved with improvements in laser technology. The “Dusting” technique utilizes a high-power laser to ablate stones into fine powder. This was previously impractical due to limitations in energy settings using low-power systems. In this video we describe our experience of using a 120-Watt (W) holmium laser with dual dusting and fragmentation modes to perform flexible URS lithotripsy. We demonstrate the technique of ureteroscopic stone dusting for large renal and ureteral stones including use of ‘dancing’ and ‘chipping’ maneuvers. METHODS We present two cases of renal stones (1.5 and 1.7 cm, respectively) and one of an impacted upper ureteral stone (1.7 cm) treated predominantly with dusting approach. Dusting is use of low pulse energy and high frequency (LoPE-HiFr) during laser lithotripsy. We used a 120-W holmium laser (Lumenis, San Jose, CA) with digital architecture that permits dual lithotripsy modes (dusting and fragmentation) and change in pulse width. A 200 micron ball-tip laser fiber was used (Flexiva, Boston Scientific, Boston, MA). Energy settings were adjusted according to stone composition, location and size, varying from 0.2-0.5 Joules (J) and rate between 30-80 Hertz (Hz). RESULTS We demonstrate effective dusting technique to treat large stones in the kidney and ureter. Our dusting strategies include use of chipping, dancing and popcorning techniques. For chipping, the laser fiber is directed to the periphery of the stone to allow small fragments to chip off. For dancing, the tip of the laser fiber is brushed back and forth across the stone surface so that it is broken down layer by layer. During dusting of renal stones if they break into medium sized fragments, we push them into dependent calyces and utilize a “popcorning” technique (1J x 15Hz). In practice, dusting is also useful for impacted ureteral stones: dusted fragments are small and do not interfere with ureteroscopic vision while appropriate dusting settings avoid inadvertent retropulsion and stone migration. We used no retrieval devices for these cases. CONCLUSIONS High-power holmium lasers have opened a new frontier in ureteroscopic laser lithotripsy by permitting a dusting approach that ablates stones into powder. Further clinical evidence is needed to better understand the efficacy of dusting and determine if outcomes are similar to conventional laser lithotripsy strategies. © 2015 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetailsCited byHumphreys M, Shah O, Monga M, Chang Y, Krambeck A, Sur R, Miller N, Knudsen B, Eisner B, Matlaga B and Chew B (2018) Dusting versus Basketing during Ureteroscopy–Which Technique is More Efficacious? A Prospective Multicenter Trial from the EDGE Research ConsortiumJournal of Urology, VOL. 199, NO. 5, (1272-1276), Online publication date: 1-May-2018. Volume 193Issue 4SApril 2015Page: e580-e581 Advertisement Copyright & Permissions© 2015 by American Urological Association Education and Research, Inc.MetricsAuthor Information Duncan R. Morhardt More articles by this author James Tracey More articles by this author J. Stuart Wolf More articles by this author Khurshid R. Ghani More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

The link between neural activity and the refinement of projections from retina to the dorsal lateral geniculate nucleus (dLGN) of thalamus is based largely on studies that disrupt presynaptic retinogeniculate activity. Postsynaptic mechanisms responsible for implementing the activity-dependent remodeling in dLGN remain unknown. We tested whether L-type Ca2+ channel activity in the form of synaptically evoked plateau potentials in dLGN cells is needed for remodeling by using a mutant mouse that lacks the ancillary β3 subunit and, as a consequence, has highly reduced L-type channel expression and attenuated L-type Ca2+ currents. In the dLGNs of β3-null mice, glutamatergic postsynaptic activity evoked by optic tract stimulation was normal, but plateau potentials were rarely observed. The few plateaus that were evoked required high rates of retinal stimulation, but were still greatly attenuated compared with those recorded in age-matched wild-type mice. While β3-null mice exhibit normal stage II and III retinal waves, their retinogeniculate projections fail to segregate properly and dLGN cells show a high degree of retinal convergence even at late postnatal ages. These structural and functional defects were also accompanied by a reduction in CREB phosphorylation, a signaling event that has been shown to be essential for retinogeniculate axon segregation. Thus, postsynaptic L-type Ca2+ activity plays an important role in mediating the refinement of the retinogeniculate pathway.

A 48-year-old man presented for evaluation of an expanding abdominal mass. Twenty years earlier, he had developed Fournier's gangrene requiring extensive debridement. He underwent augmentation cystoplasty with a catheterizable stoma due to a proximal urethral stricture. Fifteen years later, he was found to have a 14 cm x 18 cm bladder augment calculus. Simpson obstetric forceps were passed into the augment to deliver a 1110 gram stone with minimal devitalization of the colonic augmentation tissue. This is the first report of stone management with obstetric forceps in an augmented bladder. The specimen itself is among the largest stones ever reported.