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J Kyle Anderson

Publications and source records attributed to J Kyle Anderson.

15 recordsLinked to original sources
PubMed2006

Large-volume laparoscopic partial nephrectomy using the potassium-titanyl-phosphate (KTP) laser in a survival porcine model.

OBJECTIVES: Laparoscopic partial nephrectomy (LPN) remains a technically challenging procedure primarily because of difficulties with hemostasis. In an attempt to develop a hemostatic cutting instrument for laparoscopic partial nephrectomy, we evaluated the potassium-titanyl-phosphate (KTP) laser for use during large-volume laparoscopic partial nephrectomy in a porcine model. METHODS: Transperitoneal lower pole laparoscopic partial nephrectomy was performed in six pigs. Two nonsurvival animals were used initially to develop the laser technique. Four animals underwent a right-sided laparoscopic laser partial nephrectomy followed by an identical left-sided procedure 2 weeks later. Renal hilar occlusion was used in all cases. A novel 365-mum end-firing laser fibre and 80-W KTP laser were used for resection and hemostasis. All renal remnants underwent retrograde pyelography and histologic examination. RESULTS: Laser resection and hemostasis was successfully completed in all cases, and no perioperative complications occurred. Mean estimated blood loss was 80 ml (25-250 ml). Mean laser and warm ischemia times were 35 and 34 minutes, respectively. Resection speed was limited by smoke formation but not by cutting or hemostatic efficiency of the laser. Mean resected kidney mass was 30 g or 25% of total kidney mass. There were no urinomas, but, on retrograde pyelogram, extravasation was noted in seven of eight kidneys (87.5%). CONCLUSIONS: The KTP laser provides hemostasis during large-volume resection in the porcine kidney. This technique appears promising for laparoscopic partial nephrectomy in humans.

Animals↗
PubMed2006

Magnetic resonance imaging characteristics of renal tumors after radiofrequency ablation.

OBJECTIVES: The interpretation of radiographic findings in renal tumors treated with minimally invasive modalities, such as radiofrequency ablation (RFA), is critical for assessing treatment adequacy. Magnetic resonance imaging (MRI) is commonly used for patients with renal insufficiency or contrast allergy. Because the MRI experience with renal RFA is limited, we reviewed our experience and report the unique MRI characteristics of RFA-treated renal tumors. METHODS: A single-institution database of renal RFA was reviewed to identify patients followed up with MRI. A radiologist and urologist retrospectively reviewed all MRI scans to identify the characteristic lesion findings after RFA. RESULTS: Eleven patients (12 tumors) treated by RFA were followed up with MRI examinations. The mean follow-up was 10 months. The mean tumor size at ablation was 2.4 cm, with minimal reduction over time. Ablated lesions were characterized by high signal intensity on T1-weighted images, low signal intensity on T2-weighted images, and an absence of contrast enhancement. Of the patients treated by percutaneous RFA, 71% developed a characteristic peritumor halo, seen as a rim of low signal intensity on T1-weighted and T2-weighted images, surrounding a zone of perinephric fat just external to the ablated area. Two lesions demonstrated enhancement on the initial postablation MRI scan, indicating incomplete ablation. CONCLUSIONS: The MRI characteristics of successfully ablated renal tumors include the absence of enhancement, minimal size reduction over time, and high and low signal intensity on T1-weighted and T2-weighted imaging, respectively. Knowledge of these findings can aid radiologists and urologists in correctly assessing the success of RFA for kidney lesions.

Aged↗
PubMed2006

Nicotinamide adenine dinucleotide staining immediately following radio frequency ablation of renal tumors-is a positive stain synonymous with ablative failure?

PURPOSE: Nicotinamide adenine dinucleotide diaphorase staining is arguably the standard for assessing tissue viability following radio frequency ablation, yet the accuracy of this test is questionable. Thus, it is imperative to examine the reliability of nicotinamide adenine dinucleotide to predict ablation success. To evaluate the observation that immediate nicotinamide adenine dinucleotide staining may not be clinically reliable, we compared results from immediate post-ablation biopsies of renal tumors to radiological and clinical followup. MATERIALS AND METHODS: Laparoscopic radio frequency ablation was performed in 9 patients and 10 tumors using a temperature modulated radio frequency system. Cold cup biopsies were taken immediately following ablation, and processed for nicotinamide adenine dinucleotide and hematoxylin and eosin staining. Patients were then followed using contrast enhanced computerized tomography at regular intervals. RESULTS: Median tumor size was 2.3 cm. Hematoxylin and eosin stain diagnosed 8 renal cell carcinomas and 2 angiomyolipomas. A quarter of the renal cell carcinomas and both angiomyolipomas stained positive for scattered nicotinamide adenine dinucleotide diaphorase activity immediately after RFA. Mean followup for the nicotinamide adenine dinucleotide positive tumors was 28.5 months (range 24 to 30) and for the nicotinamide adenine dinucleotide negative tumors was 25 months (range 18 to 30). There was no evidence of local tumor recurrence in any patient. CONCLUSIONS: Four lesions had nicotinamide adenine dinucleotide diaphorase activity on post-ablation biopsy suggesting retained viable tissue, yet there has been no recurrence during an average 2-year followup. While negative nicotinamide adenine dinucleotide staining is consistent with nonviability, these results suggest that false-positive staining can occur immediately following RFA, making the predictive value of positive nicotinamide adenine dinucleotide diaphorase staining unclear.

Adult↗
PubMed2006

Imaging associated with percutaneous and intraoperative management of renal tumors.

As new minimally invasive treatment options for small renal tumors such as laparoscopic partial nephrectomy (LPN), radiofrequency ablation (RFA), and cryoablation(CA) have been developed, the reliance upon imaging technologies, both intraoperatively and postoperatively, has expanded greatly. CT, MRI, and ultrasonography (US)have proven themselves extremely useful in this regard, but their utility requires a thorough understanding of each modality's limitations, proper intraoperative use, and expected postoperative findings. This article discusses intraoperative use of US for LPN,RFA, and CA. The expected postoperative MRI and CT findings after CA and RFA also are covered, highlighting the different radiographic evolutionary patterns encountered after use of these technologies. Because the success of these new treatments for small re-nal tumors (especially RFA and CA) depends not only on the technology itself but also on the advantages and limitations of the associated radiographic techniques, urologists of the 21st century must be facile at interpreting and manipulating these imaging modalities to appropriately care for their renal tumor patients.

Catheter Ablation↗
PubMed2006

Serum laboratory values following uncomplicated laparoscopic urological surgery.

PURPOSE: Presentation of complications following laparoscopic surgery can be different from corresponding open surgical complications. While leukopenia has been identified as a common finding in patients with unrecognized bowel injury following laparoscopy, to our knowledge no study has determined if leukopenia or other serum abnormalities are unique to patients with laparoscopic complications. We present an analysis of postoperative laboratory values from patients after uncomplicated urological laparoscopic surgery. MATERIALS AND METHODS: A retrospective review of 50 adult patients who had previously undergone uncomplicated laparoscopic urological procedures was performed. Exclusion criteria were preexisting hematological, immune, liver or pancreatic disorders. Common serum laboratory values were measured on postoperative day 1. RESULTS: All values for bilirubin were within normal limits. Of patients undergoing a right side renal procedure, 10 of 16 (63%) had a postoperative increase in liver function tests. Amylase or lipase was increased in a total of 12 (24%) patients. Patients undergoing laparoscopic prostatectomy accounted for the majority of this group with 9 of 21 (43%) patients having increased amylase or lipase. Finally, there were no patients with immediate postoperative leukopenia. CONCLUSIONS: Following uncomplicated laparoscopic procedures, bilirubin levels are rarely affected, amylase and lipase may be acutely increased following laparoscopic prostatectomy, and white blood count is commonly increased. While 16 (36%) patients had postoperative leukocytosis, leukopenia was not detected after uncomplicated laparoscopic urological surgery and should alert the surgeon to the possibility of an undiagnosed complication.

Adult↗
PubMed2006

Radiofrequency ablation of renal tumors: intermediate-term results.

BACKGROUND AND PURPOSE: Needle ablative therapies are being offered to patients presenting with small renal masses, but long-term outcomes are currently unavailable. We report our intermediate-term results (1-4 years) after radiofrequency ablation (RFA) of small (<4-cm) renal masses. PATIENTS AND METHODS: At our institution, all renal tumors treated using RFA since May 2001 have been recorded in a prospective database. During this time, 94 tumors (mean size 2.4 cm; range 1-4.2 cm) in 78 patients were treated using a temperature-based RFA generator by either a percutaneous (59%) or a laparoscopic approach. The patients followed with imaging at 6 weeks, 3 and 6 months, and every 6 months thereafter. Only patients with at least 12 months of follow-up were eligible for this analysis; the mean follow-up was 25 months. RESULTS: Of the 89% of masses that were biopsied, 77% were renal-cell carcinomas (RCC), of which 66% were Fuhrman grade 1, 31% were grade 2, and 3% were grade 3. Three recurrences were noted, for an overall recurrence-free rate of 96.8%. In this patient population with numerous comorbid conditions, there were six deaths but only one related to renal cancer, for a cancer-specific survival rate of 98.5% and an overall survival rate of 92.3%. CONCLUSION: In the intermediate term (1-4 years), the oncologic effectiveness of RFA appears comparable to that of traditional treatments offered for small renal masses. Further studies of larger numbers of patients with longer follow-up are needed.

Adult↗
PubMed2006

Laparoscopic and open retroperitoneal lymph-node dissection for clinical stage I nonseminomatous germ-cell testis tumors.

BACKGROUND AND PURPOSE: Laparoscopic retroperitoneal lymph node dissection (L-RPLND) has been reported as efficacious for staging of the retroperitoneum in patients with stage I nonseminomatous germ-cell testis tumors (NSGCT). However, reports are limited to a few centers, and this procedure has yet to be widely accepted as an alternative to open retroperitoneal lymph node dissection (O-RPLND). Thus, we compared our contemporary open and laparoscopic experience with RPLND. PATIENTS AND METHODS: A retrospective chart review identified 28 patients who underwent either open (N = 6) or laparoscopic (N = 22) RPLND for clinical stage I NSGCT since 2000. Each patient received the appropriate modified template dissection. Perioperative demographic data, histologic nodal status, and recurrence data were evaluated. The mean follow-up was similar in the two groups. RESULTS: The mean operative time was not significantly different (313 minutes for L-RPLND v 284 minutes for O-RPLND). However, L-RPLND did have a significantly shorter hospitalization (1.2 v 8.5 days). Significantly more lymph nodes were removed with O-LPLND than with L-RPLND (mean 33 v 17). There was a single recurrence outside the modified template after both L-RPLND and O-RPLND and one within-the-template recurrence in the O-RPLND group. CONCLUSIONS: The L-RPLND is associated with less blood loss and a shorter hospital stay than O-RPLND, whereas the lymph-node yield of O-RPLND is greater. However, during the critical early follow-up period, the oncologic effectiveness and morbidity of L-RPLND for clinical stage I NSGCT appears similar to that of O-RPLND.

Adolescent↗
PubMed2005

Cost comparison of laparoscopic versus radical retropubic prostatectomy.

OBJECTIVES: To determine the cost of laparoscopic radical prostatectomy (LRP) versus open radical retropubic prostatectomy (RRP) in an actual clinical setting, we analyzed the cost data from a single institution comparing LRP and RRP. LRP is increasing in prevalence, yet questions remain regarding its higher cost versus open RRP. METHODS: A chart and cost review was performed for consecutive patients undergoing LRP (n = 30) and RRP (n = 67) between May 2003 and August 2004. The clinical characteristics, operative techniques, and radiographic and pathologic information were recorded. Detailed cost information for room and board, laboratory, pharmacy, radiology, operating room, surgical supplies, anesthesia, recovery room, electrocardiography, and respiratory services were obtained. RESULTS: The total cost of the procedure was significantly more for LRP than for RRP (6,760 dollars versus 5,253 dollars, P < 0.001). Most of this difference was due to surgical supply (1,202 dollars LRP versus 145 dollars RRP, P < 0.001) and operating room costs (1,601 dollars LRP versus 1,141 dollars RRP, P < 0.001). The room and board and pharmacy costs were significantly lower for LRP than for RRP because of the shorter mean length of stay (1.73 days versus 2.37 days, P < 0.001). The laboratory/pathology and radiology costs were not significantly different. No significant difference was found in the Gleason score, preoperative prostate-specific antigen level, subject age, positive surgical margins, lymph node involvement, or seminal vesicle involvement between the two groups. CONCLUSIONS: At a single institution, the actual LRP costs were significantly greater than the costs for RRP, and this was predominantly due to the higher surgical supply and operating room costs.

Aged↗
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

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↗
PubMed2004

Residency training in percutaneous renal access: does it affect urological practice?

PURPOSE: We evaluated the impact of residency training in percutaneous renal access on subsequent urological practice. MATERIALS AND METHODS: Surveys evaluating practice and training in percutaneous renal access were mailed to residents who graduated between 1981 and 2001. A statistical analysis was performed to determine the effect of percutaneous access training on current practice patterns in percutaneous renal procedures. A subgroup analysis was conducted for graduates with more than 10 years after residency. RESULTS: Responses were received from 37 of 48 surveys mailed (77%) and 35 surveys were eligible for analysis. A total of 92% of urologists trained in percutaneous access currently perform percutaneous surgical procedures compared to only 33% of those untrained (p <0.001). Urologists trained in access perform a mean of 14.0 percutaneous renal procedures annually while those untrained perform 3.3 procedures (p = 0.02). Only 27% of urologists trained in percutaneous access continue to perform percutaneous renal access compared to 11% of those untrained (p = 0.33). A subset analysis of urologists trained more than 10 years ago shows similar results. The primary reasons stated for not performing their own access are that the radiologist has better equipment (61%) or skills (44%), or obtaining access requires extra time (50%). CONCLUSIONS: This study suggests a relationship between training in percutaneous renal access and subsequent use of percutaneous renal procedures in the urologist's practice. Emphasis should be placed on providing continuing education opportunities to maintain competency in this important technique.

Clinical Competence↗
PubMedDate not supplied

Renal radiofrequency ablation: technique and results.

Laparoscopic or percutaneous radiofrequency ablation has become a viable treatment option for small renal tumors. Although long-term results are not yet available, intermediate results show promise for the treatment of select renal lesions. Here, we describe the basics of radiofrequency ablation technology, outline techniques used for both percutaneous and laparoscopic treatment routes, and provide a brief review of clinical results to date.

Catheter Ablation↗
PubMedDate not supplied

Management of the retained percutaneous nephrostomy catheter.

Percutaneous nephrolithotomy is a widely accepted treatment for urinary calculi, but it is not without complications. We present the case of a 76-year-old male with a retained council tip catheter after percutaneous nephrolithotomy. Fluoroscopic guidance was used to perform percutaneous puncture of the catheter balloon, and the catheter was removed without complication. Advantages of various nephrostomy tube designs and additional measures to prevent this type of complication are discussed.

Aged↗