Biomedical subjects
D A Tolley
Publications and source records attributed to D A Tolley.
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.
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.
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.
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.
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.
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.
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.
Endoscopic management of fibroepithelial polyps in the ureter.
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The effect of intravesical mitomycin C on recurrence of newly diagnosed superficial bladder cancer: a further report with 7 years of follow up.
PURPOSE: We determined the role, if any, of 1 and 5 instillations of intravesical mitomycin C in the treatment of newly diagnosed superficial bladder cancer. MATERIALS AND METHODS: A multicenter randomized clinical trial was done involving 502 patients with newly diagnosed superficial bladder cancer. After complete transurethral resection patients with newly diagnosed superficial bladder cancer. After complete resection patients were randomized into 1 of 3 treatment arms: no further treatment, 1 instillation of mitomycin C at resection and 1 instillation at resection and at 3-month intervals for 1 year (total 5 instillations). The dose of mitomycin C used was 40 mg./40 ml. water. End points were interval to first superficial recurrence, recurrence rate (defined as the number of positive cystoscopies per year) and progression-free interval rate (progression defined as the development of muscle invasive or metastatic disease, or death from bladder cancer). RESULTS: After median followup of 7 years 1 and 5 instillations of mitomycin C resulted in decreased recurrence rates and increased recurrence-free interval. The benefit of mitomycin C was observed in patients at low, medium and high risk for subsequent recurrence. There was suggestive but not conclusive evidence that 5 instillations of mitomycin C offered a slight advantage over 1 instillation. CONCLUSIONS: Our analysis confirms the positive benefit of mitomycin C to decrease the number of subsequent recurrences and increase the recurrence-free interval.
The effect of extracorporeal piezoelectric lithotripsy on the contractility of the human pelvicalyceal system.
OBJECTIVE: To assess the effect of extracorporeal piezoelectric lithotripsy (EPL) on the contractility of the human pelvicalyceal system. PATIENTS AND METHODS: Contractions of the pelvicalyceal system were measured in 12 patients (mean age 55 years) before and after EPL. Pelvicalyceal pressure was measured via a Cope nephrostomy tube which had remained in situ following stone debulking procedures days or weeks earlier. All patients were treated using a Wolf Piezolith 2300 lithotripter. RESULTS: The pelvicalyceal systems of two patients were acontractile before and after treatment. Immediately after treatment, contractions were completely abolished in eight of the remaining 10 systems, and reduced in frequency in the other two. All 10 systems regained contractions 24 h after treatment. CONCLUSION: Piezoelectric lithotripsy temporarily abolishes upper urinary tract motility.
Cystoscopy in bladder cancer.
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Comparison of the performance of two pulsed dye lasers using a synthetic stone model.
The performance of two pulsed dye laser lithotripters was compared in vitro using a synthetic calculus with gross physical properties similar to natural urinary tract calculi. Synthetic calculi were subjected to 500 shocks at nominal pulse energies of 40, 60, 80, 100 and 120 mJ using a 320 micron. fiber. Three calculi were treated at each energy level on the Technomed Pulsolith and two at each level on the Candela MDL 2000. The pattern of fragmentation was similar with both lithotripters. Increasing the energy level resulted in a linear increase in fragmentation (Pulsolith r = 0.95, MDL 2000 r = 0.99), but fragmentation was greater with the MDL 2000 than with the Pulsolith (6.01 mg/mJ versus 5.00 mg./mJ, p < 0.001). Both lasers fragmented the calculi satisfactorily. We recommend that all users of such lasers acquire a laser meter to allow monitoring of the energy delivered by the fiber tip.
Consensus of lithotriptor terminology.
The case for consensus of lithotriptor terminology is presented. An number of definitions are proposed, and it is suggested that general adoption of these terms in reporting of treatment would make it easier to compare results obtained in different centres and with different machines.
Mechanisms responsible for diminished fragmentation of ureteral calculi: an experimental and clinical study.
We molded 24 synthetic stones (mean weight 680 mg., range 641 to 715) from a commercial mixture of gypsum, silica, cellulose and polyvinyl acetate. Each stone was subjected to 400 shocks on a Wolf 2300 Piezolith and groups of 6 stones were treated in 4 different modes. Mean amounts fragmented were 243 +/- 18 mg. in a free environment, 62 +/- 18 mg. confined loosely in a latex tube, 22 +/- 8 mg. impacted in the tube and 30 +/- 8 mg. impacted alongside a 7F stent. During a 30-month period 118 patients received in situ extracorporeal shock wave lithotripsy for ureteral calculi using the same lithotriptor. The mean stone burden was 11.4 mm. (range 4 to 29). Success was greater for patients with calculi 10 mm. or less than for those with stones greater than 10 mm. (71% versus 51%, p less than 0.05), despite the former group receiving less shocks (5,404 versus 7,491). The influence of size was then excluded by studying the number of shocks delivered per mm. of calculus. Patients receiving 500 to 699 shocks per mm. showed a higher success rate than those receiving a smaller number of shocks per mm. Treatment with a greater number of shocks per mm. did not improve success rate. The experimental study demonstrated that confinement and impaction significantly diminish the rate of fragmentation of calculi. However, the clinical study suggested that there may be an optimum number of shocks per mm. that should be delivered. Treatment beyond this point fails to improve results. The 28% failure rate even in those receiving the highest number of shocks per mm. suggests that large, impacted calculi are unsuitable for treatment with in situ shock wave lithotripsy on this machine.
J-wire facilitates retrograde manipulation of ureteric calculi prior to extracorporeal shock wave lithotripsy.
During a 13-month period, 55 patients underwent attempted retrograde manipulation for ureteric lying above the pelvic brim. The mean stone burden was 11 mm (range 5-21); 41 stones (75%) were primary ureteric calculi and 14 (25%) were fragments resulting from extracorporeal shock wave lithotripsy to renal calculi. The method of retrograde manipulation was recorded prospectively. Retrograde flushing through an 8F angiography catheter with a mixture of saline and lignocaine gel was successful in 27 patients (49%). The insertion of a J-wire through the angiocath allowed for successful manipulation in a further 17 patients (31%). Retrograde manipulation was impossible in 11 patients (20%). There were 4 complications (7%), none attributable to the use of a J-wire.
First UK consensus conference on lithotriptor terminology--1989.
Recommended definitions to be used in the reporting of results of lithotripsy treatment are presented. It is suggested that these are the minimum requirements for reporting such treatment.