Search PubMed⌕ Search

Biomedical subjects

D A Tolley

Publications and source records attributed to D A Tolley.

At least 19 recordsLinked to original sources
PubMed2002

Laparoscopic and renal sparing approaches to tumours of the ureter and kidney.

Until recently, malignancies of the kidney and ureter were managed with open radical surgery. Over the last decade the urologic community has adopted the skill of laparoscopic surgery for the treatment of these tumours. Parenchymal sparing procedures have become the standard of care in the treatment of selected patients with renal and ureteral tumours and many of these surgical procedures can be performed laparoscopically or ureteroscopically. Due partly to necessity and partly to the advancement of technology, renal and ureteral sparing procedures have become commonplace for definitive treatment and palliation of these tumours. The morbidity of such procedures is significantly less than for open surgery and the future of urologic minimally invasive surgery appears secure. This review article is aimed at updating the reader in the most recent advances in these techniques.

Carcinoma, Renal Cell↗
PubMed2001

Spatial awareness in urologists: are they different?

OBJECTIVE: To compare innate spatial awareness skills, using the MIST-VR system (Ethicon Ltd, Edinburgh, a computer-based virtual reality system that objectively tests spatial awareness) among three groups of people (consultant urologists, urological trainees and controls who were not surgeons), because urological surgeons require spatial awareness for endoscopic and laparoscopic surgery, but trainees are selected by academic prowess rather than surgical aptitude. SUBJECTS AND METHODS: The MIST-VR system was used to test 122 volunteers in three groups, i.e. 39 consultant urologists, 46 urological trainees and 37 controls (not surgeons). The demographic data recorded for each group included age, sex, eyesight, handedness, and endoscopic and laparoscopic experience. Volunteers performed a repetitive series of three tasks using the system. Their performance was measured in terms of time, errors and economy of movement, as well as the duration and accuracy of diathermy in Task 3. RESULTS: The consultants were significantly older than the trainees and controls (both P<0.001) and had more endoscopic experience (P=0.005). In Task 1, the trainees made significantly fewer errors (P=0.045) and had a greater economy of movement (P=0.03) than the controls. In Task 2 the trainees performed the task more rapidly than the consultants (P=0.04) and controls (P=0.02). Trainees were more economical in movement than were consultants (P=0.031) and controls (P=0.046). In the more complex Task 3, trainees outperformed consultants in terms of errors (P=0.03), economy of movement (P=0.046), total diathermy time (P=0.005) and diathermy error (P=0.03). Controls performed similarly to the consultants. Although there was a trend towards better performance by trainees over controls, this was only significant for time (P=0.04) and total diathermy time (P=0.011). A few participants had results that were >2 SD above the mean and several people could not complete Task 3. CONCLUSIONS: Urologists do not differ from the general population in terms of innate spatial ability in this setting. There are several people who may have a defect in spatial awareness but the incidence was the same in each group. Urological trainees outperformed consultants in these tasks; the reasons for this are unclear. The MIST-VR system is of no help in aptitude testing for urological trainees, although it may have a role in teaching laparoscopic surgery. Testing other psychometric components may be more important for acquiring surgical skills than innate spatial-awareness skills. Further studies are required to investigate this possibility.

Adult↗
PubMed2001

Ischemia-reperfusion injury after relief of ureteral obstruction: an animal study.

BACKGROUND AND PURPOSE: The complex series of pathophysiologic alterations associated with obstruction nephropathy includes renal ischemia. Free-radical production follows relief of obstruction. We sought to determine whether free radicals caused additional reduction in blood flow after relief of obstruction. MATERIALS AND METHODS: In White-Landrace pigs, the left ureter was divided 6 cm distal to the ureteropelvic junction, and a nephrostomy tube was passed into the renal pelvis and exteriorized. A catheter was placed in the renal vein and exteriorized. Mean renal blood flow was measured before manipulation and during and after 6 hours of obstruction in animals receiving (N = 7) or not receiving (N = 7) allopurinol. The control groups were not subjected to ureteral obstruction and received (N = 7) or did not receive (N = 7) allopurinol. Free radicals in venous blood were measured by the Fox-1 assay for lipid peroxidation. RESULTS: After obstruction, renal blood flow declined significantly by the sixth hour (-28.73% +/- 1.81). The increase after relief of obstruction was only temporary, and by the third hour, the blood flow was again reduced (-20.14% +/- 2.67). Free radical production was significantly increased, with a peak of +24.63% being found 60 minutes after relief of obstruction. Allopurinol prevented free radical production after relief of obstruction and was associated with a return of blood flow to baseline values. CONCLUSION: Free radicals contribute to renal blood flow reduction after relief of ureteral obstruction. Functional impairment may be preventable by free radical blockade, but further studies are required to confirm this hypothesis.

Allopurinol↗
PubMed2001

Virtual endoscopy in urology.

Recent years have seen notable advances in virtual reality technology and increased interest in potential medical applications. Computed tomography and magnetic resonance imaging data sets, historically viewed as axial images, may now be used to construct a virtual reality endoscopic image, and navigator software systems allow the operator to 'fly' through the urinary tract. Technological evolution has improved the quality of reconstruction, as this is dependent on the software and data set, allowing virtual reality to begin to challenge endoscopic evaluation. This review describes the evolution of virtual reality in urology and the milestones of its current clinical use. Applications may become widespread in the diagnostic evaluation of common urological symptoms, the planning of surgery and the training of future urologists.

Cystoscopy↗
PubMed2001

Laparoscopic radical nephrectomy.

Laparoscopic radical nephrectomy has gained in popularity as an accepted treatment modality for localized renal cell carcinoma at many centers worldwide. Laparoscopic radical nephrectomy may be performed via a transperitoneal or retroperitoneal approach. Mostly, the transperitoneal approach is used. Current indications for laparoscopic radical nephrectomy include patients with T(1)-T(3a)N(0)M(0) renal tumors. Herein, transperitoneal as well as retroperitoneal laparoscopic approaches are described. Surgical outcomes and complications from published series are reviewed with comparison to open surgery. Special related concerns as oncologic principles, organ retrieval, lymphadenectomy, and concomitant adrenalectomy are addressed. In conclusion, laparoscopic radical nephrectomy is now established with considerable advantages; decreased postoperative morbidity, decreased analgesic requirements, improved cosmesis, shorter hospital stay and convalescence. Although no long-term follow-up is available, short and intermediate follow-up results confirm the effectiveness of laparoscopic radical nephrectomy.

Carcinoma, Renal Cell↗
PubMed2000

The long-term outcome after laparoscopic nephroureterectomy: a comparison with open nephroureterectomy.

OBJECTIVES: To assess the long-term outcome of the endourological management of upper tract transitional cell carcinoma (TCC) by laparoscopic nephroureterectomy (LNU) or open nephroureterectomy (ONU). PATIENTS AND METHODS: The records and pathology reports were reviewed retrospectively for 67 nephroureterectomy specimens (42 obtained by ONU and 25 by LNU). The grade, stage, lymph node status and site of the tumour were recorded for each patient. The primary end-point of the follow-up was disease-related death. RESULTS: Overall there was a high proportion of G2 (44%) and G3 (39%) disease, with a significant correlation between increasing grade and stage of TCC (r = 0.74, P < 0.001). Of the 25 patients who underwent LNU, 22 had pelvicalyceal or upper ureteric TCC and conversion to open surgery was required in three (12%). Of the TCCs in this group half were G3 and half were invasive (pT1-3). In the ONU group there were more ureteric tumours because of selection criteria and overall 16 (39%) were G3 and half were invasive. Information on nodal status was available in one LNU and two of the ONU reports. Within a mean follow-up of 32.9 months for LNU and 42.3 months for ONU, nine (21%) of the ONU group and four (16%) of the LNU group had died, with a mean survival of 15.1 and 17 months, respectively, after surgery (not significant). All of these deaths were associated with G3 pT1-3 disease. CONCLUSIONS: In this series the case mix and outcomes were similar for those undergoing LNU and ONU. As laparoscopic renal surgery is associated with less postoperative morbidity it would seem reasonable to offer LNU to all patients with upper tract TCC, where appropriate and when there is no evidence of local invasion or metastasis. Because of the strong correlation between grade and stage, preliminary ureteroscopic assessment and biopsy may influence the surgical approach adopted.

Aged↗
PubMed2000

Patient selection before endopyelotomy: can it improve the outcome?

OBJECTIVE: To compare endopyelotomy and primary reconstructive procedures in patients with pelvi-ureteric junction (PUJ) obstruction and with risk factors for endopyelotomy failure. PATIENTS AND METHODS: Nineteen patients (eight female and 11 male, mean age 34.5 years, range 15-82) underwent endoluminal ultrasonography (US) before treatment for PUJ obstruction; the US findings were used to direct the treatment. Patients with unavoidable crossing vessels, massive hydronephrosis and crossing vessels associated with previous failed endopyelotomy were selected for reconstructive surgery. The clinical results of these patients (group 1) were compared with 12 consecutive patients who had undergone endopyelotomy before the use of endoluminal ultrasonography (group 2). RESULTS: Imaging detected 17 crossing vessels in 13 of the 19 patients. Six patients underwent primary reconstructive surgery and 13 underwent endopyelotomy. The endoluminal US findings changed treatment in some way in nine patients. Endopyelotomy was successful in 12 of the 13 patients and reconstructive surgery successful in five of six patients. The success after endopyelotomy improved from eight in 12 patients in group 2 to 12 of 13 in group 1 (P = 0.16, NS). CONCLUSIONS: Endoluminal US can be used to select patients in whom endopyelotomy is likely to fail. Using primary reconstructive procedures in these patients might improve the overall outcome, but these preliminary findings need to be confirmed in a larger study.

Adolescent↗
PubMed2000

2000 AD: still a role for the intravenous urogram in stone management?

The intravenous urogram (IVU) remains a useful investigation in the assessment of upper urinary tract calculi. Helical computed tomography scanning appears to have superseded the IVU in the diagnosis of acute flank pain due to a higher sensitivity in diagnosis. Results of extracorporeal shockwave lithotripsy (ESWL) for lower calyceal stones are generally disappointing. Recent studies using the intravenous urogram have demonstrated that an acute infundibulopelvic angle may be a significant indicator of the likelihood of failure of ESWL. A prospective evaluation of the role of spatial anatomy in the clearance of lower calyceal stones by ESWL is needed. In future this parameter may be used to determine treatment protocols for lower calyceal stones. Future imaging methods may make the IVU redundant, but for the time being it remains an essential part of the urologist's armamentarium.

Contrast Media↗
PubMed1999

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↗
PubMed1999

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↗
PubMed1999

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↗
PubMed1999

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↗
PubMed1999

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↗
PubMed1999

Current advances in shock wave lithotripsy.

The introduction of shock wave lithotripsy into clinical practice revolutionized the management of urinary tract stone disease. As experience has been gained with its use, however, the limitations and adverse effects associated with it have been recognized.

Adult↗
PubMed1999

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↗