Browsing by Subject "Ureteroscopy"

Now showing 1 - 6 of 6
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    Association Between Randall's Plaque Stone Anchors and Renal Papillary Pits
    (Mary Ann Liebert, 2019-04-01) Borofsky, Michael S.; Williams, James C., Jr.; Dauw, Casey A.; Cohen, Andrew; Evan, Andrew C.; Coe, Fredric L.; Worcester, Elaine; Lingeman, James E.; Anatomy and Cell Biology, School of Medicine
    Introduction: Renal papillary pits are commonly encountered during ureteroscopy. The mechanism by which such pits arise is unclear. One hypothesis is that pits represent sites where stones overgrowing Randall's plaque (RP) were dislodged. We sought to examine this theory by using digital ureteroscopy and stone μCT. Materials and Methods: Patients undergoing endoscopic stone removal had procedures recorded and stones analyzed by using μCT. Stones with evidence of Randall's plaque anchors (RPAs) were identified in a blinded fashion. Surgical videos were reviewed independently by two urologists. Results: Twenty-eight patients had μCT-confirmed stones with RPA. Among them, 93% were recurrent stone formers and 75% had had prior stone procedures. Metabolic abnormalities were present in 87%, with 79% classified as idiopathic calcium oxalate stone formers. A mean of 7.6 stones with RPA were identified per procedure. In each case, papillary pits were visualized before any stone manipulation and in several cases the active dislodgement of an attached stone led to immediate identification of an underlying pit. Such stones routinely demonstrated an RPA on μCT. The average depth of RPA was 302 ± 172 μm, consistent with the corresponding shallow pits visualized on the papillary surface. Conclusions: Stones overgrowing RP are capable of pulling away a piece of papilla when dislodged, resulting in a visible papillary pit. This process manifests as an RPA on the undersurface of the stone and a papillary pit on the corresponding area of attachment. Identification of pits may help identify patients who form stones primarily by the RP mechanism.
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    Endoscopic Evidence That Randall's Plaque is Associated with Surface Erosion of the Renal Papilla
    (Mary Ann Liebert, Inc., 2017-01) Cohen, Andrew J.; Borofsky, Michael S.; Anderson, Blake B.; Dauw, Casey A.; Gillen, Daniel L.; Gerber, Glenn S.; Worcester, Elaine M.; Coe, Fredric L.; Lingeman, James E.; Urology, School of Medicine
    OBJECTIVE: This study was conducted to assess the reliability and precision of an endoscopic grading scale to identify renal papillary abnormalities across a spectrum of equipment, locations, graders, and patients. MATERIALS AND METHODS: Intra- and interobserver reliability of the papillary grading system was assessed using weighted kappa scoring among 4 graders reviewing a single renal papilla from 50 separate patients on 2 occasions. Grading was then applied to a cohort of patients undergoing endoscopic stone removal procedures at two centers. Patient factors were compared with papillary scores on the level of the papilla, kidney, and patient. RESULTS: Graders achieved substantial (kappa >0.6) intra- and inter-rater reliability in scored domains of ductal plugging, surface pitting, and loss of contour. Agreement for Randall's Plaque (RP) was moderate. Papillary scoring was then performed for 76 patients (89 kidneys, 533 papillae). A significant association was discovered between pitting and RP that held both within and across institutions. A general linear model was then created to further assess this association and it was found that RP score was a highly significant independent correlate of pitting score (F = 7.1; p < 0.001). Mean pitting scores increased smoothly and progressively with increasing RP scores. Sums of the scored domains were then calculated as a reflection of gross papillary abnormality. When analyzed in this way, a history of stone recurrence and shockwave lithotripsy were strongly predictive of higher sums. CONCLUSIONS: Renal papillary pathology can be reliably assessed between different providers using a newly described endoscopic grading scale. Application of this scale to stone-forming patients suggests that the degree of RP appreciated in the papilla is strongly associated with the presence of pitting. It also suggests that patients with a history of recurrent stones and lithotripsy have greater burdens of gross papillary disease.
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    Fragmentation of Stones by Burst Wave Lithotripsy in the First 19 Humans
    (Wolters Kluwer, 2022) Harper, Jonathan D.; Lingeman, James E.; Sweet, Robert M.; Metzler, Ian S.; Sunaryo, Peter L.; Williams, James C., Jr.; Maxwell, Adam D.; Thiel, Jeff; Cunitz, Bryan W.; Dunmire, Barbrina; Bailey, Michael R.; Sorensen, Mathew D.; Urology, School of Medicine
    Purpose: We report stone comminution in the first 19 human subjects by burst wave lithotripsy (BWL), which is the transcutaneous application of focused, cyclic ultrasound pulses. Materials and methods: This was a prospective multi-institutional feasibility study recruiting subjects undergoing clinical ureteroscopy (URS) for at least 1 stone ≤12 mm as measured on computerized tomography. During the planned URS, either before or after ureteroscope insertion, BWL was administered with a handheld transducer, and any stone fragmentation and tissue injury were observed. Up to 3 stones per subject were targeted, each for a maximum of 10 minutes. The primary effectiveness outcome was the volume percent comminution of the stone into fragments ≤2 mm. The primary safety outcome was the independent, blinded visual scoring of tissue injury from the URS video. Results: Overall, median stone comminution was 90% (IQR 20, 100) of stone volume with 21 of 23 (91%) stones fragmented. Complete fragmentation (all fragments ≤2 mm) within 10 minutes of BWL occurred in 9 of 23 stones (39%). Of the 6 least comminuted stones, likely causative factors for decreased effectiveness included stones that were larger than the BWL beamwidth, smaller than the BWL wavelength or the introduction of air bubbles from the ureteroscope. Mild reddening of the papilla and hematuria emanating from the papilla were observed ureteroscopically. Conclusions: The first study of BWL in human subjects resulted in a median of 90% comminution of the total stone volume into fragments ≤2 mm within 10 minutes of BWL exposure with only mild tissue injury.
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    Management of Nephrolithiasis in Pregnancy: Multi-Disciplinary Guidelines From an Academic Medical Center
    (Frontiers Media, 2021-12-22) Lee, Matthew S.; Fenstermaker, Michael A.; Naoum, Emily E.; Chong, Suzanne; Van de Ven, Cosmas J.; Bauer, Melissa E.; Kountanis, Joanna A.; Ellis, James H.; Shields, James; Ambani, Sapan; Krambeck, Amy E.; Roberts, William W.; Ghani, Khurshid R.; Radiology and Imaging Sciences, School of Medicine
    Introduction: The management of nephrolithiasis during pregnancy can be stressful for urologists due to concerns for investigations and treatments that may pose risk of fetal harm, and unfamiliarity with optimal management of these complex patients. In response, we created multi-disciplinary evidence-based guidelines to standardize the care for obstetric patients presenting with flank pain and suspicion for nephrolithiasis. Methods: A multi-disciplinary team involving Urology, Obstetric Anesthesiology, Obstetrics and Gynecology, Diagnostic Radiology, and Interventional Radiology from a single academic medical center was assembled. A PubMed search was performed using keywords of pregnancy/antepartum, nephrolithiasis/calculi/kidney stones, ureteroscopy, non-obstetric surgery, complications, preterm delivery, MRI, computerized tomography, renal bladder ultrasound (RBUS), and anesthesia to identify relevant articles. Team members reviewed their respective areas to create a comprehensive set of guidelines. One invited external expert reviewed the guidelines for validation purposes. Results: A total of 54 articles were reviewed for evidence synthesis. Four guideline statements were constructed to guide diagnosis and imaging, and seven statements to guide intervention. Guidelines were then used to create a diagnostic and intervention flowchart for ease of use. In summary, RBUS should be the initial diagnostic study. If diagnostic uncertainty still exists, a non-contrast CT scan should be obtained. For obstetric patients presenting with a septic obstructing stone, urgent decompression should be achieved. We recommend ureteral stent placement as the preferred intervention if local factors allow. Conclusions: We present a standardized care pathway for the management of nephrolithiasis during pregnancy. Our aim is to standardize and simplify the clinical management of these complex scenarios for urologists.
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    Removal of Small, Asymptomatic Kidney Stones and Incidence of Relapse
    (Massachusetts Medical Society, 2022) Sorensen, Mathew D.; Harper, Jonathan D.; Borofsky, Michael S.; Hameed, Tariq A.; Smoot, Kimberly J.; Burke, Barbara H.; Levchak, Branda J.; Williams, James C., Jr.; Bailey, Michael R.; Liu, Ziyue; Lingeman, James E.; Radiology and Imaging Sciences, School of Medicine
    Background: The benefits of removing small (≤6 mm), asymptomatic kidney stones endoscopically is unknown. Current guidelines leave such decisions to the urologist and the patient. A prospective study involving older, nonendoscopic technology and some retrospective studies favor observation. However, published data indicate that about half of small renal stones left in place at the time that larger stones were removed caused other symptomatic events within 5 years after surgery. Methods: We conducted a multicenter, randomized, controlled trial in which, during the endoscopic removal of ureteral or contralateral kidney stones, remaining small, asymptomatic stones were removed in 38 patients (treatment group) and were not removed in 35 patients (control group). The primary outcome was relapse as measured by future emergency department visits, surgeries, or growth of secondary stones. Results: After a mean follow-up of 4.2 years, the treatment group had a longer time to relapse than the control group (P<0.001 by log-rank test). The restricted mean (±SE) time to relapse was 75% longer in the treatment group than in the control group (1631.6±72.8 days vs. 934.2±121.8 days). The risk of relapse was 82% lower in the treatment group than the control group (hazard ratio, 0.18; 95% confidence interval, 0.07 to 0.44), with 16% of patients in the treatment group having a relapse as compared with 63% of those in the control group. Treatment added a median of 25.6 minutes (interquartile range, 18.5 to 35.2) to the surgery time. Five patients in the treatment group and four in the control group had emergency department visits within 2 weeks after surgery. Eight patients in the treatment group and 10 in the control group reported passing kidney stones. Conclusions: The removal of small, asymptomatic kidney stones during surgery to remove ureteral or contralateral kidney stones resulted in a lower incidence of relapse than nonremoval and in a similar number of emergency department visits related to the surgery.
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    Variability in stone composition and metabolic correlation between kidneys in patients with bilateral nephrolithiasis
    (Elsevier, 2019-12-20) Rivera, Marcelino E.; Nottingham, Charles U.; Borofsky, Michael S.; Kissel, Suzanne M.; Maniar, Viraj; Dauw, Casey A.; York, Nadya E.; Krambeck, Amy E.; Lingeman, James E.; Urology, School of Medicine
    Introduction: To evaluate the clinical significance of discordant stone analyses in patients undergoing bilateral ureteroscopy. Methods: A retrospective chart review was performed for all patients undergoing stone extraction with bilateral ureteroscopy at our institution in an aim to identify patients who had bilateral stone analysis and 24-hour urine chemistry data available. Stones were then classified based upon the dominant present (>50%). Twenty-four hour urinalysis results were reviewed and statistical analysis performed comparing discordant and concordant patient populations, assessing significant differences that would potentially influence clinical management. Results: We identified 79 patients (158 renal units) who had bilateral stones removed at the time of ureteroscopy. The majority of stones were classified as calcium oxalate (CaOx) (60.1%) followed by calcium phosphate (CaP) (27.8%), brushite (5.1%), uric acid (UA) (4.4%) and cystine (2.5%). Discrepancies in stone classifications were present 24% of the time. Evaluation of 24-hour urinalysis results demonstrated that patients with CaOx:CaP stone discordance compared to CaOx:CaOx concordant stone formers were more likely to have an elevated pH (p=0.02) and lower uric acid supersaturation (p=0.01). Conclusions: Discrepancies in stone mineral content are common in patients with bilateral stone disease. A single stone analysis from one side in the setting of bilateral stone disease is insufficient for management of patients with bilateral renal stones, and may lead to mismanagement when this misrepresented information is utilized in addition to 24-hour urinalysis results. At least one stone analysis should be performed from both sides during a bilateral stone extraction procedure.