Papers by Raymond Leveillee
International Journal of Hyperthermia, 2019
Introduction: Microwave ablation (MWA) uses heat to ablate undesired tissue. Development of prepl... more Introduction: Microwave ablation (MWA) uses heat to ablate undesired tissue. Development of preplanning algorithms for MWA of small renal masses requires understanding of microwave-tissue interactions at different operating parameters. The objective of this study was to compare the performance of two MWA systems in in-vivo porcine kidneys. Methods: Five ablations were performed using a 902-928 MHz system (24 W, 5 min) and a 2450 MHz system (180 W, 2 min). Nonlinear regression analysis of temperature changes measured 5 mm from the antenna axis was completed for the initial 10 s of ablation using the power equation DT ¼ at b and after the inflection point using an exponential equation. Thermal damage was calculated using the Arrhenius equation. Long and short axis ablation diameters were measured. Results: The average 'a' varied significantly between systems (902-928 MHz: 0.0299 ± 0.027, 2450 MHz: 0.1598 ± 0.158), indicating proportionality to the heat source, but 'b' did not (902-928 MHz: 1.910 ± 0.372, 2450 MHz: 2.039 ± 0.366), signifying tissue type dependence. Past the inflection point, average steady-state temperature increases were similar between systems but reached more quickly with the 2450 MHz system. Complete damage was reached at 5 mm for both systems. The 2450 MHz system produced significantly larger short axis ablations (902-928 MHz: 2.40 ± 0.54 cm, 2450 MHz: 3.32 ± 0.41cm). Conclusion: The 2450 MHz system achieved similar steady state temperature increases compared to the 902-928 MHz system, but more quickly due to higher output power. Further investigations using various treatment parameters and precise thermal sensor placement are warranted to refine equation parameters for the development of an ablation model.
The use of general descriptive names, registered names, trademarks, service marks, etc. in this p... more The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use.
Journal of Urology, 2004
hemorrhagic complication was 18/189 (9.5%) in the HEP group, of which 16/189 (8.5%) were major. T... more hemorrhagic complication was 18/189 (9.5%) in the HEP group, of which 16/189 (8.5%) were major. This rate was 6/165 (3.6%), with 5/165 (3.0%) being major, in the SCD group. CONCLUSIONS: In urologic Japaroscopic patients, fractionated subcutaneous heparin is associated with increased hemorrhagic complications (p=0.03) without an apparent reduction in thrombotic complications (p>0.50) as compared with the use of sequential compression boots.
Current Opinion in Urology, 2009
To review the role of robotics for the management of ureteral pathology, in particular, ureterope... more To review the role of robotics for the management of ureteral pathology, in particular, ureteropelvic junction obstruction and ureteric stricture disease. Minimally invasive surgery has an expanding role in the management of ureteric pathology. Minimally invasive surgery modalities are associated with decreased morbidity when compared with open reconstructive techniques. Robotics solves many of the technical complexities that may be prohibitive with standard laparoscopic surgery such as intracorporeal suturing. Several studies have demonstrated equivalent or superior short-term outcomes in comparison to traditional open techniques. Encouraging long-term data are now emerging for robotic pyeloplasty. In 2008, robotic surgery appears to be a feasible and effective alternative to laparoscopy for reconstructive procedures of the ureter and may represent a potential solution to some of the drawbacks associated with ureteric reconstruction.
Current Opinion in Urology, 1996
International Journal of Surgery, 2016
h i g h l i g h t s The detection of small renal masses (SRM) has increased due to the increased ... more h i g h l i g h t s The detection of small renal masses (SRM) has increased due to the increased use of cross-sectional abdominal imaging. Renal parenchyma preservation has become the standard of care. Thermal ablation (TA) is discussed and often offered for all patients with SRM as near-equivalent treatment without respect to age or co-morbidities. As provider experience improves and long-term outcome studies become available, TA is becoming increasingly accepted as a potential new standard of care for solid SRM. This review will highlight the role of image guided TA. We will discuss radiofrequency ablation (RFA) however, the principles will apply to any TA device. Improvements in image guided hardware/software has improved accuracy of probe placement.
International Journal of Surgery, 2016
h i g h l i g h t s The detection of small renal masses (SRM) has increased due to the increased ... more h i g h l i g h t s The detection of small renal masses (SRM) has increased due to the increased use of cross-sectional abdominal imaging. Renal parenchyma preservation has become the standard of care. Thermal ablation (TA) is discussed and often offered for all patients with SRM as near-equivalent treatment without respect to age or co-morbidities. As provider experience improves and long-term outcome studies become available, TA is becoming increasingly accepted as a potential new standard of care for solid SRM. This review will highlight the role of image guided TA. We will discuss radiofrequency ablation (RFA) however, the principles will apply to any TA device. Improvements in image guided hardware/software has improved accuracy of probe placement.
Journal of Vascular and Interventional Radiology, 2010
JSLS, Journal of the Society of Laparoendoscopic Surgeons, 2012
Nephron-sparing surgery is currently the standard of care for the management of small renal masse... more Nephron-sparing surgery is currently the standard of care for the management of small renal masses. While both neoadjuvant and adjuvant conventional external beam radiotherapy have failed to demonstrate an oncologic benefit for the treatment of renal cell carcinoma, more recent work aims to explore the utility of stereotactic radiotherapy. We present the case of a 70-year-old woman who failed primary treatment of a small renal mass with the CyberKnife radiotherapy system and describe her successful salvage treatment with robot-assisted partial nephrectomy. This case demonstrates the safety of robotic surgery for the management of renal tumors following failed stereotactic radiotherapy.
Journal of Endourology, 2007
To evaluate our experience with radiofrequency ablation (RFA) of renal tumors in the range of 3 t... more To evaluate our experience with radiofrequency ablation (RFA) of renal tumors in the range of 3 to 5 cm. A series of 96 patients underwent 104 tumor laparoscopic or percutaneous CT-guided RFAs. We identified 37 tumors between 3 and 5 cm at the time of the ablation. Non-conducting temperature probes, independent of the radiofrequency (RF) electrode, were placed at the peripheral and deep margins of the tumor in order to achieve real-time temperature monitoring of the ablation zone. All ablations were continued until the peripheral and deep temperature probes reached 60 degrees C. All 37 patients (100%) achieved complete necrosis at the initial session. There were two radiographic failures at 9 months and 30 months that required a second treatment (95% radiographic success rate). Tissue samples taken at the time of the re-treatment (one partial nephrectomy with numerous biopsies of the deep and peripheral margins and one repeat ablation with eight core biopsies) showed no evidence of viable tumor with hematoxylin and eosin or nicotinamide adenine dinucleotide viability stains. The average length of follow-up was 11.3 months (range 1-44 months). No patient with localized disease at the time of the RFA developed local extension or metastatic disease in follow-up. The majority of renal tumors between 3 and 5 cm can be ablated with complete necrosis in a single session. Placement of independent temperature probes at the peripheral and deep margins of the tumor provides real-time monitoring that assists in the deployments of the RF electrode and determining the appropriate duration of the ablation cycles. Attention to real-time thermometry decreases the need for repeat sessions to achieve complete necrosis for larger tumors. Likewise, real-time thermometry decreases the incidence of overtreatment of normal parenchyma and prevents collateral damage to adjacent vital structures (ureter, pancreas, bowel, spleen, nerves) outside the desired zone of ablation.
Journal of Endourology, 2011
Objectives To evaluate the feasibility and clinical efficacy of a novel intraabdominal retractor ... more Objectives To evaluate the feasibility and clinical efficacy of a novel intraabdominal retractor device in laparoendoscopic single-site nephrectomy(LESS-N). Methods Between February 2012 and February 2017, 98 patients underwent LESS-N in our institution, including 38 patients with benign renal disease and 60 patients with malignant renal disease. 39 were performed conventional LESS-N(C-LESS-N) and 59 were performed intraabdominal retractor-assisted LESS-N(IAR-LESS-N). Demographic data, and perioperative and postoperative data were collected and analyzed retrospectively. Results All the procedures were completed successfully. In C-LESS-N group, four patients were added one 5-mm additional trocar and two patients were converted to open surgery. In IAR-LESS-N group, no patients required additional trocars or conversion to open surgery. The mean operative time was lower in IAR-LESS-N group than that in C-LESS-N group (94.2 min vs 127.4 min, P < 0.05). The mean renal vascular management time declined from 25.4 min in C-LESS-N group to 18.4 min in IAR-LESS-N group (P < 0.05). The mean estimated blood loss was 128.6 ml in C-LESS-N group and 102.3 ml in IAR-LESS-N group (P < 0.05). Two patients in C-LESS-N group required blood transfusion, while none of the patients in IAR-LESS-N group did. No severe postoperative complications occurred in both groups. Study limitations included retrospective study, short follow-up, and accumulated surgical experience and skills. Conclusions Intraabdominal retractors allow performance of LESS-N with improved working space, quicker renal hilar management, and shortened total operative time. It is expected that the application of intraabdominal retractors, along with the new robotic platform might revive LESS and translate into a renewed future interest of LESS.
Journal of Endourology, 2009
Objectives: To report our single-center experience with robotic ureteroneocystostomy for the trea... more Objectives: To report our single-center experience with robotic ureteroneocystostomy for the treatment of distal ureteral obstruction. Methods: We performed robot-assisted laparoscopic ureteroneocystostomies between May 2005 and October 2007. We retrospectively collected information on patient demographics, and compared renal scans with furosemide washout and radiographic imaging before and after repair to determine radiographic success. Statistical analysis was performed using statistical software via paired Student's t test analysis. Results: Eight robot-assisted laparoscopic ureteroneocystostomies on seven patients were performed over a 30month period. The etiology of the ureteric stricture was iatrogenic injury after hysterectomy in three patients, impacted stone in three, and infiltrative endometriosis in one. Mean stricture length was 2.2 cm. Right ureteroneocystostomy was performed in five patients and on the left in one, while one patient had bilateral disease. Mean operative time was 247 minutes (range 120-480), and average blood loss was 109 mL (range 50-200). Mean length of hospital stay was 2 days. All the procedures were completed successfully robotically without open conversion. Of the seven patients, one patient experienced recurrent symptoms. Subsequent imaging confirmed an anastomotic narrowing, which was treated by balloon dilation. There were no intraoperative or postoperative complications. Subsequent 99m Tc-mercaptoacetyltriglycine scans showed no evidence of obstruction. After a mean follow-up of 18 months (range 5-31), relative renal function of the entire group of patients improved after ureteroneocystostomy, although this did not achieve statistical significance (p ¼ 0.26). Conclusions: Robotic ureteroneocystostomy is a safe and effective treatment option for the management of distal ureteric stricture disease.
Journal of Endourology, 2011
Purpose: The goal of this report is to describe our initial clinical experience performing a simp... more Purpose: The goal of this report is to describe our initial clinical experience performing a simple nephrectomy with the SPIDER (Single Port Instrument Delivery Extended Reach) laparoendoscopic single-site (LESS) surgical system. Patient and Methods: One patient with a nonfunctioning kidney secondary to a ureteropelvic junction obstruction underwent a simple nephrectomy through a single incision performed using the SPIDER surgical system. We assessed the technical feasibility, efficiency, and perioperative outcomes. Results: The SPIDER-LESS nephrectomy was performed successfully without additional skin incisions for laparoscopic ports, instrument clashing, or open conversion. Total operative time was 210 minutes with blood loss of 50 mL. The patient experienced no intraoperative or postoperative complications. Pathologic evaluation confirmed atrophic renal parenchyma. Conclusions: The SPIDER surgical system LESS nephrectomy is feasible and safe. Future refinements of the technology and prospective studies are needed to further optimize its application in urology.
Electrodes and multiple electrode systems for radiofrequency ablation: a proposal for updated ter... more Electrodes and multiple electrode systems for radiofrequency ablation: a proposal for updated terminology Abstract Research on technology for soft tissue radiofrequency (RF) abla-tion is ever advancing. A recent proposal to standardise terminology of RF electrodes only deals with the most frequently used commercial electrodes. The aim of this study was to develop a logical, versatile and unequivocal terminology to describe present and future RF electrodes and multiple electrode systems. We have carried out a PubMed search for the
Journal of Endourology, 2008
Journal of endourology case reports, 2016
Since the development of the first flexible ureteroscope, in 1964, technological advances in imag... more Since the development of the first flexible ureteroscope, in 1964, technological advances in image quality, flexibility, and deflection have led to the development of the first single-use digital flexible ureteroscope, LithoVue™ (Boston Scientific, Marlborough, MA). With respect to reusable fiber-optic and now digital ureteroscopes, there is an initial capital cost of several thousand dollars (USD) as well as, controversy regarding durability, the cost of repairs and the burdensome reprocessing steps of ureteroscopy. The single-use LithoVue eliminates the need for costly repairs, the occurrence of unpredictable performance, and procedural delays. Renal stones located in the lower pole of the kidney can be extremely challenging as extreme deflections of greater than 160° are difficult to maintain and are often further compromised when using stone treatment tools, such as laser fibers and baskets. This case describes an initial use of the LithoVue digital disposable ureteroscope in th...
Urology, 2001
Objectives. To examine personal financial management among residents to answer three research que... more Objectives. To examine personal financial management among residents to answer three research questions: do residents make reasonable financial choices; why do some residents not save; and what steps can be taken to improve residents' personal financial decisions. Methods. Portions of the Federal Reserve Board's Survey of Consumer Finances were modified and piloted to elicit demographic, expense, saving, and income data. The final questionnaire was completed by 151 urology residents at 20 programs. Results. Comparing residents with the general population in the same age and income categories, the median debt/household income ratio was 2.38 versus 0.64. Residents had greater educational debt, greater noneducational debt, and lower savings. Resident participation in retirement accounts was 100% at institutions with employer-matching 401k or 403b plans, 63% at institutions with nonmatching 401k or 403b plans, and 48% at institutions without retirement plans for residents (P ϭ 0.002). Fifty-nine percent of residents budgeted expenses, 27% had cash balances below $1000, 51% had paid interest charges on credit cards within the previous year, and 12% maintained unpaid credit card balances greater than $10,000. The median resident income was $38,400. Conclusions. A significant minority of residents appear not to make reasonable financial choices. Some residents save little because of a failure to budget, indebtedness, high projected income growth, or insufficient attention to personal financial management. Residents save more when they are eligible for tax-deferred retirement plans, particularly when their institution matches their contributions. Many residents would benefit from instruction concerning prudent financial management.
The Journal of Urology, 2002
Purpose: We assessed unenhanced helical computerized tomography (CT) secondary findings as predic... more Purpose: We assessed unenhanced helical computerized tomography (CT) secondary findings as predictors of renal obstruction as determined by diuretic scintirenography, and determined their reproducibility. Materials and Methods: We performed a retrospective review of the records of 77 consecutive patients with unenhanced helical CT findings (stones and secondary findings, including renal parenchymal edema, hydronephrosis, hydroureter, perinephric fat stranding, periureteral fat stranding and extravasation) of urinary lithiasis who had also undergone concomitant diuretic scintirenography during the initial emergency room evaluation during a 1-year period. Unenhanced helical CT films were independently reviewed by 2 attending radiologists (blinded to clinical outcome) to determine interobserver variability. The results were compared to those of diuretic scintirenography. Results: Considerable interobserver variability, as evidenced by values ranging from 0.26 to 0.60, existed for the diagnosis of secondary findings associated with urinary lithiasis on unenhanced helical CT. There was no significant difference in terms of CT findings between patients diagnosed by diuretic scintirenography as having high grade/complete obstruction and those with partial obstruction (p values 0.24 to 0.85 for the 6 unenhanced helical CT findings analyzed). Analyses of variance followed by Tukey's pairwise comparisons showed no significant difference in average number of unenhanced helical CT findings between patients with high grade/complete obstruction (mean plus or minus standard deviation 4.4 Ϯ 1.31), partial obstruction (4.4 Ϯ 1.30), and decompression/no obstruction (4.2 Ϯ 1.16). However, the mean number of unenhanced helical CT findings for patients with normal scintirenography/no obstruction (1.9 Ϯ 1.41) was significantly different from each of the other 3 diuretic scintirenography groups. Separate logistic regression analyses showed that each unenhanced helical CT finding, except for renal parenchymal edema and urinary extravasation, was a significant predictor of "any degree of obstruction" (high grade and partial obstruction groups) compared to "no obstruction" (decompressed and no obstruction groups). Odds ratios (95% confidence interval) ranged from 6.15 (2.25, 16.82) for perinephric fat stranding to 3.41 (1.30, 8.97) for hydroureter. When these analyses were repeated after exclusion of 8 patients with bladder/passed stones, only perinephric fat stranding and periureteral fat stranding remained significant predictors of "any degree of obstruction," with respective odds ratios of 4.21 (1.49, 11.91) and 4.08 (1.31, 12.65). Conclusions: Measures of agreement between trained, independent radiologists with respect to unenhanced helical CT secondary findings show considerable variability. The average number of CT consensus findings is not helpful in differentiating patients with variable degrees of obstruction, except for those with normal scintirenography/no obstruction. Unenhanced helical CT findings, except for renal parenchymal edema and urinary extravasation, are significant predictors of "any degree of obstruction" (high grade or partial obstruction) compared to "no obstruction" (decompressed or no obstruction). Therefore, unenhanced helical CT findings may be useful for identifying patients with any degree of obstruction but do not differentiate between those with high grade and partial obstruction.
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Papers by Raymond Leveillee