Biomedical subjects

Courtney Lee

Publications and source records attributed to Courtney Lee.

10 recordsLinked to original sources

PubMed2006

Durability of flexible ureteroscopes: a randomized, prospective study.

PURPOSE: We performed a randomized, prospective, multi-institutional study evaluating the durability of commercially available flexible ureteroscopes. MATERIALS AND METHODS: A total of 192 patients were randomized to the use of 7 less than 9Fr flexible ureteroscopes, including the Storz 11274AA and Flex-X, the ACMI DUR-8 and DUR-8 Elite, Wolf models 7330.170 and 7325.172, and the Olympus URF-P3. Information about total and lower pole use time, the number and method of ureteroscope insertion, and they type and duration of accessory instrumentation was recorded. Surgeons were asked to rate the visibility and maneuverability of the instrument on a scale of 0-poor to 10-excellent. RESULTS: The indication for ureteroscopy was upper tract calculi in 87% of cases. Of ureteroscope insertions 97% were performed through an access sheath. The average of number of cases before repair ranged from 3.25 for the Wolf 7325 to 14.4 for the ACMI DUR-8 Elite. Average ureteroscope operative time was statistically longer for the DUR-8 Elite (494 minutes) than for the Flex-X (p = 0.047), and the Wolf 7325 and 7330 (p = 0.001 and 0.001, respectively). Duration of use before repair for the URF-P3 (373 minutes) was statistically longer than for the Wolf 7325 and 7330 (p = 0.016 and 0.017, respectively). Minutes of use with an instrument in the working channel were significantly more with the DUR-8 Elite and the URF-P3 than the Wolf 7330 (p = 0.017 and 0.008) and 7325 (p = 0.012 and 0.005, respectively). The ureteroscope that experienced the greatest average duration of lower pole use was the URF-P3, while the shortest was the Wolf 7325 (103 vs 20 minutes, p = 0.005). Average minutes of laser use before breakage was significantly longer for the DUR-8 Elite than for the Wolf 7325 (110 vs 21 minutes, p = 0.021) and 7330 (24 minutes, p = 0.025). CONCLUSIONS: Currently available less than 9Fr flexible ureteroscopes remain fragile instruments. The DUR-8 Elite and Olympus URF-P3 proved to be the most durable devices.

Equipment Design↗

PubMed2005

Minimally invasive therapy for benign prostatic hyperplasia: practice patterns in Minnesota.

BACKGROUND AND PURPOSE: Benign prostatic hyperplasia (BPH) affects more than 50% of men by the age of 60 and 90% by age 85. Many of these men are not candidates for surgical procedures such as transurethral resection of the prostate (TURP), stimulating the development of less-invasive forms of therapy. We studied the utilization of these newer therapies by urologists practicing in Minnesota. MATERIALS AND METHODS: An anonymous questionnaire was sent to 174 members of the Minnesota Urological Society, of which 58 were available for analysis. A case scenario was presented of a patient with BPH refractory to medical therapy. The options were traditional and minimally invasive therapies. The physician was asked to select whether he or she would offer each option and perform the procedure or refer the patient within or outside the practice. Statistical analysis was performed using chi-square and two-sample t-tests on Minitab software. The results were considered significant at P < 0.05. RESULTS: While 59% of the respondents would offer both minimally invasive and traditional alternatives, 10% would offer only minimally invasive therapy, while 29% would offer only traditional therapy (P = 0.01). The most common minimally invasive therapies offered were transurethral microwave thermotherapy and (55%) and transurethral needle ablation (33%). If they offered a form of minimally invasive therapy, the majority of respondents would perform the procedure themselves. Rural urologists were less likely to offer minimally invasive therapy (43%) than metro physicians (81%; P = 0.035). There was no significant difference in the use of minimally invasive therapies by rural and urban urologists (P = 0.409) or urban and metropolitan urologists (P = 0.119). Urologists completing their training between 1960 and 1980 were less likely to offer minimally invasive therapy. There was no significant difference in the likelihood of offering traditional versus minimally invasive alternatives according to the percent of managed care in the practice. CONCLUSIONS: Urologists closer to the completion of their residency training are more likely to include a minimally invasive technique in their treatment plan, while urologists practicing in rural Minnesota are less likely to offer minimally invasive procedures. Further emphasis should be placed on increasing the availability of minimally invasive techniques in rural settings.

Age Factors↗

PubMed2005

Randomized evaluation of Ureteral Stents using validated Symptom Questionnaire.

BACKGROUND AND PURPOSE: Ureteral stents are associated with significant pain and urinary symptoms. Manufacturers have altered stent designs and materials in an attempt to minimize this morbidity. This study evaluated the impact of these modifications. PATIENTS AND METHODS: Stent manufacturers were asked to provide the 6F ureteral stent they believed would be associated with the least patient discomfort. Patients undergoing uncomplicated ureteroscopy were randomized to the Bard Inlay, Cook Endo-Sof, Microvasive Contour, Applied Medical Vertex, or Surgitek Classic Double-Pigtail stent. The Ureteric Stent Symptom Questionnaire (USSQ) was administered on days 1, 3, and 5, and the patients maintained a narcotic diary. The data were analyzed using ANOVA and nonparametric methods. RESULTS: A total of 44 patients (73%) completed all USSQ questionnaires. Urinary symptom scores were significantly lower for the Inlay stent on day 3 than for the Vertex (P = 0.01), Contour (P = 0.05), Endo-Sof (P = 0.03), and Classic (P = 0.02) stents. No significant differences were noted in pain and general symptom scores or narcotic use. CONCLUSIONS: The Bard Inlay stent is associated with less-severe urinary symptoms than other ureteral stents. The USSQ is a sensitive tool to measure differences between stents.

Adult↗

PubMed2005

Temperature activated deflection of a novel ureteroscopic laser fiber sheath.

PURPOSE: Loss of active deflection with insertion of a holmium laser fiber can significantly decrease the efficacy of intrarenal flexible ureteroscopy. We evaluated the impact of inserting a novel, temperature activated, deflectable laser sheath on active deflection and flow rates. METHODS AND MATERIALS: Active deflection of 5 flexible ureteroscopes was measured with an empty channel and following separate insertions of 2, 272 mum holmium fibers. Insertion of the same fibers was then repeated through a proprietary, temperature activated, coiling nitinol sheath. Active deflection of the sheath following insertion into the working channel was achieved by a rapid flush of 10 cc hot water (60C) through the irrigation side port. Release of active deflection was obtained by repeating this maneuver with cold water (15C). Degrees of deflection were measured in triplicate. Flow rates were measured at 100 cm H2O pressure. RESULTS: Active deflection with an empty working channel decreased significantly with insertion of the 2 laser fibers (12 to 32 degrees). Insertion of the laser fiber through the nitinol sheath followed by temperature activation of the sheath maximized active deflection beyond baseline measures with the laser fibers by up to 60 degrees. Flow rates in all ureteroscopes decreased significantly with the use of the Powerflex sheath (Optical Integrity, Panama City, Florida) but it remained above 12 ml per minute in all ureteroscopes. CONCLUSIONS: A temperature activated, deflectable nitinol sheath facilitates active deflection with a 272 mum holmium laser fiber in the working channel of the flexible ureteroscope, suggesting strong potential for clinical evaluation.

Alloys↗

PubMed2004

Systematic evaluation of stone basket dimensions.

OBJECTIVES: To evaluate 17 commercial stone baskets for characteristics we believe are favorable for stone extraction. METHODS: The ACMI (Sur-Catch 3.0), Bard (Dimension 3.0), Boston Scientific (Zero-tip 2.4/3.0, Segura 2.4/3.0, Gemini 3.0, Parachute 3.1), Cook (N-Circle 2.2/3.0/3.2, N-Force 3.2, Flatwire 2.0), and Sacred Heart (Halo 1.9, Vantage 2.4, Summit 3.0, Hercules 3.0) were tested in triplicate. The maximal basket width was measured with a digital caliper as the basket length was opened in 0.5 to 2-mm increments using a mechanical caliper under optical light microscope visualization. Baskets were rated for the linearity of opening and length at which the target basket width (5 mm) was reached. RESULTS: The only basket to exhibit linear opening was the N-Circle. All other baskets opened in an exponential fashion, with the initial excursion in length corresponding to little change in basket width, followed by a rapid increase in basket width as the basket extended further. The N-Circle 2.2F, 3.0F, and 3.2F baskets reached the target basket width at a basket length of 9.4, 9.7, and 9.6 mm, respectively. As a group, the tipless baskets opened more rapidly to the target basket width (9.4 to 14.8 mm) than did the flat-wire baskets (17.5 to 22.7 mm) or helical baskets (18.6 to 24.8 mm). CONCLUSIONS: A basket that requires a shorter basket excursion to reach a 5-mm width will be easier to maintain in the field of view. Linear basket opening provides the operator with greater control to engage a stone. After closure of a basket on a 5-mm stone, the larger the basket length dimension, the greater the likelihood the calculus may escape.

Equipment Design↗

PubMed2004

Minimally invasive therapy for renal cell carcinoma: is there a new community standard?

OBJECTIVES: To evaluate current practice use of laparoscopic and minimally invasive therapies in the treatment of renal cell cancer. METHODS: A questionnaire was sent to 174 members of the Minnesota Urological Society. The first case scenario described a 6-cm lesion not amenable to nephron-sparing surgery. The second case scenario described a 3-cm lower pole exophytic mass amenable to nephron-sparing surgery. The treatment options included traditional therapy (open partial or radical nephrectomy) and minimally invasive therapy (laparoscopic radical or partial nephrectomy or renal cryoablation). RESULTS: Our survey response rate was 49%. For the first scenario, 86% of respondents would offer open radical nephrectomy; however, 57% would offer laparoscopic surgery. Of those urologists offering laparoscopic surgery, 14% would refer outside their practice and 43% would use a hand-assisted approach. Sixty-four percent of the metropolitan and 56% of the urban respondents would offer a form of minimally invasive therapy; only 29% of rural respondents offered these options. For the second scenario, 90% of respondents would offer open partial nephrectomy and 45% a minimally invasive therapy; however, 24% of these would refer outside their practice. Thirty-eight percent of respondents would offer laparoscopic partial nephrectomy and 22% of respondents would offer renal cryoablation. Urologists completing residency after 1990 were more likely to offer a minimally invasive option (65%) compared with urologists completing residency before 1990 (31%). CONCLUSIONS: Minimally invasive therapy for renal cell cancer is evolving into a community standard of care, with urologists relying heavily on outside referrals to access minimally invasive alternatives. Younger urologists living in metropolitan and urban areas are more likely to offer minimally invasive therapy. Additional emphasis should be placed on increasing the availability of minimally invasive techniques in rural settings.

Adult↗

PubMed2004

Radial dilation force of tipless and helical stone baskets.

PURPOSE: To evaluate one aspect of tipless and helical stone basket function that is critical for ureteral stone extraction: the radial-dilation force. MATERIALS AND METHODS: Nine commercially available tipless baskets and five commercially available helical stone baskets were tested. Two Teflon blocks were positioned with the lower block sitting on a digital scale and the upper block secured to a plastic frame and base. A 0.01-inch gap was maintained between the blocks using a digital micrometer. Alignment pins secured the position of the lower block in relation to the upper block. A 4-mm cylindrical hole was drilled through the center of the block interface, and each basket was passed through the hole and opened to its fully extended length. The basket was then slowly retracted through the hole, and the maximum force reading was recorded. Twenty repetitions were performed for each basket. RESULTS: Of the tipless baskets > or =3.0F, the Cook N-Circle 3.2F provided the best radial dilation (24.7 +/- 0.4 g). For tipless baskets <3.0F, the Sacred Heart Vantage 2.4F provided the best radial dilation (19.6 +/- 0.8 g). Of the helical baskets, the Sacred Heart Hercules provided the most radial dilation (102 +/- 12.1 g) followed by the Cook N-Force (71.8 +/- 4.3 g). CONCLUSION: The radial-dilation force of tipless and helical stone baskets differs significantly among baskets and may impact stone extraction performance in the ureter.

Equipment Design↗

PubMed2003

Evaluation of overall costs of currently available small flexible ureteroscopes.

OBJECTIVES: To perform a meta-analysis of the currently available data regarding the durability of flexible ureteroscopes to establish cost estimates for the purchase and use of five currently available, smaller than 9F, ureteroscopes. Healthcare costs have become increasingly germane to the determination of disease management strategies. Improved ureteroscope technology has expanded the role of these instruments. However, the initial purchase costs and high maintenance costs have become problematic with these fragile instruments. METHODS: Ureteroscope durability data on the Storz 11274AA, Olympus URF-P3, Wolf 7325.172, ACMI AUR-7, and ACMI DUR-8 were collected from three prior studies. Combining the durability data and cost data regarding the initial purchase price and maintenance costs of these instruments, we calculated the overall costs associated with the use of each of the ureteroscopes for 25, 50, 75, and 100 cases during the first year (warranties included) and with subsequent use. RESULTS: The variability in the costs associated with the use of the currently available smaller than 9F ureteroscopes was significant. The initial instrument purchase price, durability, repair costs, and associated warranties all contributed to large discrepancies in the cost of performing ureteroscopy. In this model, during the first year of ownership, the projected cost of performing 100 ureteroscopic cases varied by a difference of 95% depending on the ureteroscope used. CONCLUSIONS: Physicians and institutions that perform ureteroscopy should strongly consider the purchase price, durability, repair cost, and associated warranties before the purchase of small flexible ureteroscopes.

Costs and Cost Analysis↗

PubMedDate not supplied

Contemporary management of ureteropelvic junction obstruction: practice patterns in Minnesota.

BACKGROUND AND PURPOSE: Ureteropelvic junction (UPJ) obstruction can be addressed surgically by an open, laparoscopic, endoscopic, or fluoroscopic procedure. Our objective was to establish what surgical alternatives are currently offered by urologists in Minnesota. MATERIALS AND METHODS: A questionnaire was sent to 174 members of the Minnesota Urological Society. Practice settings were characterized as rural, urban, or metropolitan on the basis of the ZIP-code classifications of the Minnesota Ambulance Association and state geographic legislation. Respondents were asked to select initial treatment options for an adult patient with flank pain, decreased renal function, and hydronephrosis secondary to UPJ obstruction. RESULTS: Whereas 60% of the respondents would offer open pyeloplasty, only 12% would offer it as the only treatment option. The two most common minimally invasive therapies offered were the Acucise balloon (48%) and percutaneous antegrade endopyelotomy (48%). Rural urologists were more likely to offer Acucise balloon incision (71%) than were urban (28%; P=0.045) or metropolitan (55%; P=0.412) urologists. CONCLUSIONS: The majority of urologists still offer open pyeloplasty as first-line therapy for UPJ obstruction. Further emphasis should be placed on increasing the availability of endoscopic and laparoscopic procedures.

Adult↗

PubMedDate not supplied

Nephrolithiasis: "scope," shock or scalpel?

PURPOSE: To evaluate treatment preferences for complex urinary calculi. MATERIALS AND METHODS: A questionnaire was sent to 174 members of the Minnesota Urological Society. Three case scenarios were presented: a 1.5-cm lower-pole calculus with unfavorable anatomy, a 1.4-cm proximalureteral calculus, and a staghorn calculus. The treatment options offered were extracorporeal shockwave lithotripsy (SWL), ureteral stenting, ureteroscopy (URS), percutaneous nephrolithotomy (PCNL), and open surgery. RESULTS: Our survey response rate was 49%. A PCNL for staghorn calculi was more likely to be offered by urologists in metropolitan (100%; P<0.001) and urban (100%; P=0.003) settings than rural settings (57%). Whereas only 22% of urban and metropolitan urologists would offer anatrophic nephrolithotomy, 43% of rural urologists would include this among their treatment options. A PCNL was more likely to be offered by urologists trained after 1980 (100%) than by urologists trained before 1980 (81%; P=0.004). For a large lower-pole calculus with unfavorable anatomy, urologists with >50% managed-care practices were more likely (91%) than urologists with <50% managed-care practices (65%) to select PCNL for such stones (P=0.034). Whereas 82% of metropolitan urologists would select PCNL, 43% of rural urologists would consider SWL as initial therapy. A URS was more likely to be offered by urologists trained after 1980 (16%) than by urologists trained before 1980 (0; P=0.044). For a large proximal-ureteral calculus, metropolitan urologists were most likely (64%) to use stents initially (urban 28%; P=0.014; rural 14%; P=0.017). Rural urologists were more likely to offer SWL (100%) than were metro urologists (55%; P=0.024). CONCLUSIONS: Initial therapy for nephrolithiasis differs significantly according to geographic location, year of residency completion, and the percentage of managed-care patients in a urologist's practice. Future emphasis should be placed on increasing the availability of endoscopic techniques in rural settings.

Decision Making↗