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Biomedical subjects

F X Keeley

Publications and source records attributed to F X Keeley.

At least 37 records · Page 2Linked to original sources

A prospective study of endoluminal ultrasound versus computerized tomography angiography for detecting crossing vessels at the ureteropelvic junction.

PURPOSE: Crossing vessels at the ureteropelvic junction are associated with bleeding complications and a higher risk of failure after endopyelotomy. We compared computerized tomography (CT) angiography and endoluminal ultrasound for detecting crossing vessels before planned endopyelotomy. MATERIALS AND METHODS: Preoperatively patients underwent CT angiography. Intraoperative evaluation included retrograde ureteropyelography, endoluminal ultrasound and ureteroscopy. Intraoperative findings were used to direct treatment. RESULTS: Endoluminal ultrasound detected 19 crossing vessels in 14 of 20 patients (70%), while CT detected 9 crossing vessels in 7 (35%). Endoluminal ultrasound identified a septum between the ureter and renal pelvis in 7 patients (35%) but CT demonstrated none. On the basis of imaging findings we selected 5 patients for pyeloplasty, and endoluminal ultrasound accurately predicted the absence or presence of crossing vessels in all 5. CT angiography was accurate in 3 patients. However, in 2 patients a total of 4 vessels were missed by CT. A total of 15 patients underwent endopyelotomy with no bleeding complications. The presence or absence of a septum on endoluminal ultrasound was confirmed in all patients. Imaging findings altered the treatment chosen in 4 patients and changed the direction of the incision at the ureteropelvic junction in another 4. Clinical and radiographic success was achieved in all 13 patients (100%) with adequate followup. CONCLUSIONS: Endoluminal ultrasound was more sensitive than CT angiography for identifying crossing vessels and septa. Treatment based on endoluminal ultrasound findings may decrease complications and improve the results of minimally invasive treatment for ureteropelvic junction obstruction.

Adolescent↗

Electrokinetic lithotripsy: safety, efficacy and limitations of a new form of ballistic lithotripsy.

OBJECTIVE: To investigate the safety and efficacy of electrokinetic lithotripsy (EKL), a ballistic lithotripter which uses high-energy magnetic fields to propel an impactor to fragment calculi. PATIENTS AND METHODS: The records and radiographs of 121 patients who underwent ureteroscopy using the EKL for stones in the upper (26), mid (28) or lower (67) ureter were reviewed retrospectively. Ureteroscopy was performed with an 8.5 F semi-rigid ureteroscope, through which a 3 F EKL probe was passed. RESULTS: A total of 148 stones (mean stone size 11.5 mm, range 6-40) in 121 patients were treated using the EKL. One patient was lost to follow-up. Of 148 stones, 147 (99.3%) were fragmented, including five that had resisted fragmentation with either pulsed-dye laser or electrohydraulic lithotripsy. Despite this, only 45 of 56 patients (80%) with a single stone in the lower ureter were rendered stone-free after a single ureteroscopic procedure. Seven patients in this group (12%) required shock-wave lithotripsy for fragments that had been propelled into the kidney, while four patients (7%) required repeat ureteroscopy for retained ureteric fragments. Complications were limited to minor ureteric perforations in two patients, both of which were treated with a stent. CONCLUSION: EKL is an inexpensive and reliable endoscopic method which fragments nearly all urinary calculi. Its limitations include the propulsion of fragments and the need to use an offset, semi-rigid ureteroscope. We recommend the use of a basket or graspers to remove fragments of >/=4 mm after EKL.

Adolescent↗

Laparoscopic ureterolithotomy: the Edinburgh experience.

OBJECTIVE: To review our experience with laparoscopic ureterolithotomy. PATIENTS AND METHODS: Since 1993, we have performed laparoscopic ureterolithotomy in 14 patients with ureteric stones. Laparoscopy was carried out in nine patients as a salvage procedure after failed ureteroscopy (six), shock wave lithotripsy (two), or both (one), and in five patients as a primary procedure for large stones (mean 27.2 mm, range 18-40). Patients in the former group had already undergone a mean of 1.88 procedures (range 1-4). Laparoscopic ureterolithotomy was carried out via a transperitoneal approach. Associated ureteric strictures were incised at the time of ureterotomy. RESULTS: All procedures were completed laparoscopically and all patients were rendered stone-free after a single procedure. The mean operative duration was 105 min. Ureteric strictures were incised in three patients, in two of whom dilatation was subsequently required; all three had a successful result. There were three minor complications. CONCLUSIONS: Laparoscopic ureterolithotomy can be a safe and effective procedure; it should be considered as a primary procedure for large mid- and upper ureteric stones.

Adult↗

Optimizing results of lithotripsy using robust electromagnetic probe.

BACKGROUND AND OBJECTIVE: A significant impediment to the measurement of the pressures and forces created by lithotripter shockwaves has been their destructive properties, which have rendered most measuring devices impractical. We have developed and tested a robust electromagnetic probe to measure cavitational forces in vitro in the focal zones of extracorporeal lithotripters. The probe responds to the pressure gradient generated by the radial motion of cavitation bubbles. MATERIALS AND METHODS: The effects of shockwaves from the Dornier MPL 9000 electrohydraulic lithotripter were measured over the lifetime of multiple electrodes. RESULTS: The pulse energy from the electrodes dropped off rapidly after approximately 50% of the lifetime quoted by the manufacturer. The electrodes were more efficient at higher power settings. As a result, we altered our protocol for the treatment of ureteral stones to use a higher kilovoltage and a second electrode whenever necessary. Stone-free rates after shockwave lithotripsy (SWL) in situ for stones < 11 mm have increased from 68.2% to 83.3%, and the retreatment rate has dropped from 23% to 15%. Despite significantly higher power settings (23.7 kV v 18.7 kV; P < 0.0001), the need for sedoanalgesia has remained relatively constant (26% v 31%). CONCLUSIONS: Measurement of cavitational forces from lithotripters using a robust electromagnetic probe is useful in planning treatment strategy. We have demonstrated a clinically measurable improvement since implementing our new treatment protocol. Because the probe responds directly to cavitational forces, it should also prove useful for the objective comparison of different SWL machines.

Electromagnetic Phenomena↗

Endourological management of severely encrusted ureteral stents.

BACKGROUND: Encrustion of ureteral stents is a well-known phenomenon which can be treated easily if recognized promptly. Severe encrustation, however, which leads to renal impairment, presents a challenge in management. PATIENTS AND METHODS: Four patients with encrusted stents were referred to our institution for management. All had impaired function of the affected kidney. Each was managed by either retrograde ureteroscopy or a combination of percutaneous and ureteroscopic procedures. RESULTS: All four of the patients were rendered stone free following an average of 2.5 (range 1-3) procedures. Renal function improved in all patients postoperatively. CONCLUSIONS: Encrustation is a potentially serious complication of the use of ureteral stents, as it can lead to renal impairment. Timely endourologic intervention can result in recovery of renal function.

Adult↗

Clearance of lower-pole stones following shock wave lithotripsy: effect of the infundibulopelvic angle.

OBJECTIVE: To assess the effect of anatomic factors, especially the angle of the lower-pole infundibulum, on stone clearance following shock wave lithotripsy (SWL) in order to determine selection criteria for percutaneous nephrolithotomy. METHODS: We retrospectively analyzed 116 patients with single lower-pole stones measuring 11-20 mm treated with SWL. Intravenous urograms were reviewed to measure the infundibulopelvic angle, the angle of the infundibulum to the vertical, and the anatomy of lower-pole calyces. RESULTS: The overall stone-free rate was 52%. Factors most closely associated with a stone-free status were obtuse infundibulopelvic angle, lack of calyceal distortion, and a large infundibular diameter. The infundibulopelvic angle was the only factor to attain significance in predicting stone-free status (p = 0.012). The size of the stone did not predict eventual stone-free status (p = 0.911), but larger stones were more likely to require intervention after SWL. CONCLUSION: For solitary lower-pole stones 11-20 mm in size, the angle of the lower-pole infundibulum as it relates to the pelvis plays a role in eventual stone clearance and should be taken into account before choosing a mode of treatment.

Adolescent↗

A review of our first 100 cases of laparoscopic nephrectomy: defining risk factors for complications.

OBJECTIVE: To present the complications from our first 100 cases of laparoscopic nephrectomy, a technically demanding procedure requiring lengthy experience, and to define the risk factors. PATIENTS AND METHODS: Indications for laparoscopic nephrectomy included patients requiring nephrectomy for benign pathology and those requiring nephroureterectomy for upper tract transitional cell carcinoma confined to the upper ureter and/or renal pelvis. All patients were operated on by one surgeon (D.A.T.) via a transperitoneal route and data on diagnosis, outcome and complications collected prospectively. RESULTS: The overall complication rate was 18%, of which 3% were major and 15% minor complications. Five cases were converted to open surgery electively. Complications and conversions were associated with a history of pyonephrosis, previous renal surgery, staghorn calculi, polycystic kidney disease, and xanthogranulomatous pyelonephritis. While there was no discernible decline in the decrease in complications with experience, operative duration decreased from a mean of 204 min for the first 20 cases to 108 min for the last 20. Complications and conversions were more closely associated with diagnosis than with the surgeon's experience. CONCLUSION: Laparoscopic nephrectomy and nephroureterectomy can be undertaken for a variety of indications with reasonable complication and conversion rates. Although inflammatory conditions increase the difficulty of these procedures, we feel that patients requiring nephrectomy for benign disease should be offered a trial of laparoscopic surgery.

Adolescent↗

Laparoscopic nephroureterectomy: making management of upper-tract transitional-cell carcinoma entirely minimally invasive.

Endoscopic treatment of upper-tract transitional-cell carcinoma (TCC) is well established. Nevertheless, many patients still required major ablative surgery. We have applied our experience with laparoscopic nephrectomy to the performance of laparoscopic nephroureterectomy in order to make the management of upper-tract TCC entirely minimally invasive. Since 1993, we have performed 22 laparoscopic nephroureterectomies for upper-tract TCC. Initially, we excluded patients with tumors below the pelvic brim, but we now offer a trial of laparoscopy to all patients. We describe the evolution of our technique, which involves resecting the ureteral orifice prior to laparoscopic dissection of the kidney and ureter. We have had to convert three cases to open surgery, one each for bleeding, failure to progress, and unappreciated tumor extent. Operative times averaged 156 minutes, which compares well with contemporary times for open nephroureterectomy. Complication rates, transfusion requirements, and length of stay, although higher than those of laparoscopic nephrectomy, were all reduced in comparison with open nephroureterectomy.

Carcinoma, Transitional Cell↗

Adjuvant mitomycin C following endoscopic treatment of upper tract transitional cell carcinoma.

PURPOSE: A variety of topical agents have been used for transitional cell carcinoma of the upper tract. Mitomycin C has limited systemic absorption when given intravesically because of its high molecular weight. We reviewed our experience with mitomycin C following endoscopic treatment of upper tract transitional cell carcinoma. MATERIALS AND METHODS: Since 1991, 19 patients (21 renal units) have undergone a total of 28 treatments with mitomycin C for high volume, recurrent or multifocal transitional cell carcinoma. Of the 19 patients 12 had an absolute indication for nephron sparing treatment. Following ureteroscopic biopsy and treatment of upper tract transitional cell carcinoma, 40 mg. mitomycin C in 3 divided doses was instilled via a ureteral catheter, which was clamped between doses to give an exposure time of 30 minutes. Eighteen patients have undergone ureteroscopic surveillance following a total of 26 treatments. RESULTS: No systemic side effects occurred during or after treatment with mitomycin C. One patient had a prominent local inflammatory reaction following neodymium:YAG ablation and mitomycin C treatment of a renal pelvic tumor. The average size of the treated tumors was 17 mm. (range 5 to 30). The grade of the tumors (when known) was 1 in 5 patients, 1 to 2 in 2, 2 in 8 and 3 in 4. Most tumors were treated with either neodymium:YAG (6 cases) or holmium:YAG laser (8) or a combination of both (8). Following 1 to 4 treatments with mitomycin C 11 of 19 evaluable renal units (58%) were rendered free of disease. Six of those 11 renal units (54%) had an ipsilateral recurrence after a mean of 30 months of followup, 4 of which were treated endoscopically, and 7 (64%) are now disease-free without extirpative surgery. Four patients have undergone nephroureterectomy for persistent or recurrent disease. No patient has suffered local or distant progression of disease. CONCLUSIONS: Instillation of mitomycin C for upper tract transitional cell carcinoma appears to be safe and can be considered for adjuvant treatment in select cases. More data are necessary to determine its efficacy.

Aged↗

Use of p53 in the diagnosis of upper-tract transitional cell carcinoma.

OBJECTIVES: To assess the usefulness of p53 staining of cytology specimens obtained ureteroscopically in the diagnosis of upper-tract transitional cell carcinoma (TCC). METHODS: We collected specimens from 43 patients undergoing a total of 50 ureteroscopic procedures for a variety of indications, including the diagnosis of TCC. Specimens were obtained by direct biopsy with forceps or basket whenever possible. We examined specimens for evidence of TCC by cytospin as well as cell block for any visible fragments. Each specimen was then stained for overexpression of p53 by immunohistochemical staining, and the degree of staining was graded. Eight patients subsequently underwent nephroureterectomy; the pathologic specimens were stained for p53 and compared with the cytology results. RESULTS: Staining for p53 was positive in specimens from 36 of 50 procedures, including all 28 with ureteroscopic or cytologic evidence of TCC (P < 0.0001). By contrast, cytology accurately diagnosed only 23 of the 28. Specimens from all 14 procedures that were negative also stained negative for p53. Specimens from all 8 procedures with no tumor seen and atypical cytology stained positive for p53; 4 of 5 patients with adequate follow-up have had a tissue diagnosis of TCC at that site. Overall, 35 of the 36 specimens that stained positive for p53 were obtained from patients with some history of TCC (P < 0.0001). No significant association could be found between degree of staining and grade (P = 0.3034). The degree of staining of ureteroscopic biopsy specimens was identical to that of the nephroureterectomy specimen in 6 of 8 cases. CONCLUSIONS: p53 nuclear protein staining of cytology specimens obtained ureteroscopically appears to correlate well with the presence of upper-tract urinary TCC. Further study is needed to determine if it can provide a definitive diagnosis in cases with indeterminate cytologic findings.

Carcinoma, Transitional Cell↗

Diagnostic accuracy of ureteroscopic biopsy in upper tract transitional cell carcinoma.

PURPOSE: Our aim was to determine the accuracy of ureteroscopic biopsies and cytological techniques compared to open surgical specimens of upper tract transitional cell carcinoma. MATERIALS AND METHODS: From 1985 to 1995, 51 cases of upper tract transitional cell carcinoma were diagnosed ureteroscopically and distal ureterectomy or nephroureterectomy was performed. Each patient underwent direct ureteroscopic inspection and biopsy. Fresh samples were delivered to the cytopathology laboratory, where they were examined using cytospin and smear. A cell block was prepared when visible tissue was present. Grades of ureteroscopic biopsies were compared to grades and stages of surgical specimens in 42 cases. RESULTS: Cytological evaluation was positive for malignancy in 48 of the 51 cases (94.1%). Grading of ureteroscopic specimens was possible in 42 cases (82.4%). Transitional cell carcinoma grade on ureteroscopy accurately predicted tumor grade and stage in the surgical specimens. Of 30 low or moderate grade ureteroscopic specimens 27 (90%) proved to be low or moderate grade transitional cell carcinoma in the surgical specimens, while 11 of the 12 high grade ureteroscopic specimens (91.6%) proved to be high grade transitional cell carcinoma (p < 0.0001). Of 30 low or moderate grade ureteroscopic specimens 26 (86.6%) had a low stage (Ta or T1) tumor. In contrast, 8 of 12 high grade ureteroscopic specimens (66.7%) had invasive tumor (stage T2 or T3) in the surgical specimen (p = 0.0006). CONCLUSIONS: Ureteroscopic inspection and biopsy combined with cytological techniques provide accurate information regarding grade and stage of upper tract transitional cell carcinoma.

Adult↗

Ureteroscopic treatment and surveillance of upper urinary tract transitional cell carcinoma.

PURPOSE: We determined the efficacy of ureteroscopic treatment of upper urinary tract transitional cell carcinoma. MATERIALS AND METHODS: Of 92 patients diagnosed with upper urinary tract transitional cell carcinoma at our institution from 1985 to 1995, 38 (41 kidneys) underwent ureteroscopic treatment and followup. Semirigid and flexible ureteroscopes were used to examine the collecting system. Tumors were biopsied, and treated with fulguration, the neodymium:YAG laser and/or the holmium:YAG laser. Patients were treated every 6 to 12 weeks until tumor-free and then followed on a strict endoscopic protocol. RESULTS: Mean and median followup was 35.1 and 26 months, respectively (range 3 to 116). Grading of ureteroscopic biopsies was possible in 40 of 41 cases. Initial grading of tumors was low (grade 1 or 1 to 2) in 21 kidneys, grade 2 in 14 and grade 3 in 5. Of 41 kidneys 28 (68%) were documented as tumor-free ureteroscopically at some time following treatment, including 8 (29%) with subsequent recurrences that were treated endoscopically and 24 (86%) with no evidence of disease at the most recent followup. No patient to date has had progression of disease during endoscopic followup. High tumor grade, size and multifocality were significantly associated with tumor persistence and recurrence. Location in the kidney versus ureter was not a significant prognostic factor. Of the recurrent tumors 75% were not identified radiographically but were only discovered endoscopically. Two of 8 kidneys removed after endoscopic treatment had no tumor stage (pT0). CONCLUSIONS: Endoscopic treatment of upper urinary tract transitional cell carcinoma is a reasonable method to treat carefully select patients based on strict indications. Complete endoscopic followup at regular intervals is essential to rule out recurrences.

Aged↗

Laparoscopic division of crossing vessels at the ureteropelvic junction.

Endopyelotomy has become an accepted mode of treatment for primary and secondary ureteropelvic junction (UPJ) obstruction, but a 15% to 30% failure rate persists. The presence of crossing vessels at the UPJ has been implicated as a common cause of complications, failures, and recurrences. In the past, renal angiography was necessary to identify crossing vessels. We have utilized endoluminal ultrasonography to identify crossing vessels at the UPJ and to guide endoscopic incisional techniques. Previously, whenever crossing vessels were identified that could not be safely avoided during endopyelotomy, we had recommended dismembered pyeloplasty, an open surgical procedure with a long recovery time. We report our experience with laparoscopic division of crossing vessels in two patients, one with a symptomatic horseshoe kidney. Each patient had a large crossing vessel identified by endoluminal ultrasonography; consequently, endopyelotomy was abandoned. The location and distribution of the vessels were then delineated by angiography. The aberrant vessels were dissected free and divided laparoscopically. The patients returned to work within 1 week. Follow-up diuretic renal scans showed complete resolution of obstruction (T1/2 < 10 minutes) in one patient; no change was noted in the patient with a horseshoe kidney. Both patients have remained free of symptoms and normotensive for more than 12 months. Laparoscopic division of crossing vessels may play a role in the treatment of patients with extrinsic ureteral obstruction from aberrant vessels.

Adult↗