R. C. Tiptaft

Multimodal management of urolithiasis in renal transplantation.

To report the largest single series of renal transplant patients (adults and children) with urolithiasis, assess the risk factors associated with urolithiasis in renal transplant recipients, and report the outcome of the multimodal management by endourological and open procedures.

Management of encrusted ureteral stents impacted in upper tract

OBJECTIVES To present our series of patients with ureteral stent encrustation and give indwelling times and management. Encrustation is one of the most serious complications of ureteral stents. METHODS A retrospective review was undertaken of all encrusted stents during a 4-year period. The inclusion criterion was a stent that required some form of intervention above the ureteral orifice to remove it. Combinations of extracorporeal shock wave lithotripsy, ureteroscopy, percutaneous nephrolithotomy, and open surgery were used to achieve stent removal. RESULTS Forty-nine impacted encrusted stents were treated in 41 patients. Of these, 75.5% had become encrusted within 6 months and 42.8% within 4 months. The mean indwelling time was 5.6 months. Forty-seven stents were removed by endourologic techniques, with 4 requiring extracorporeal shock wave lithotripsy alone, 28 ureteroscopy, and 10 a combination of both. Five patients underwent successful percutaneous nephrolithotomy. One patient underwent open surgery, and in one removal failed. The mean number of procedures per patient was 1.94. CONCLUSIONS Stent encrustation can pose a serious challenge to the endourologist, and indwelling times should be minimized to avoid problems. Patients often require multiple treatments and a combination of extracorporeal shock wave lithotripsy and ureteroscopy offers highly successful outcomes and often avoids the need for more invasive techniques.

Squamous cell carcinoma of bladder.

Examination of the histology of all bladder tumors presented to the London Hospital over a ten-year period revealed a surprisingly low incidence of squamous bladder carcinoma. We would support the view of other workers that this tumor usually presents at an advanced stage and carries with it a poor prognosis. However, when no evidence of metastatic disease is evident, treatment with standard protocol of radiation therapy and cystectomy should achieve the same results as for the transitional cell tumor. Squamous cell carcinoma of the bladder would appear to be as radiosensitive as its transitional cell counterpart.

A randomized controlled trial of human versus robotic and telerobotic access to the kidney as the first step in percutaneous nephrolithotomy

Objective: We present results from the first randomized controlled trial of human vs. telerobotic access to the kidney during percutaneous nephrolithotomy. Methods: To compare (a) human with robotic percutaneous needle access and (b) local robotic with trans-Atlantic robotic percutaneous needle access, we used a validated kidney model into which a needle was inserted 304 times. Half the insertions were performed by a robotic arm and the other half by urological surgeons. Order was decided randomly except for a sub-group of 30 trans-Atlantic robotic procedures that were controlled by a team at Johns Hopkins, Baltimore, via four ISDN lines. Results: All attempts were successful within three passes with a median time of 35 s for human attempts compared with a median of 57 s for robotic attempts. The robot was slower than the human to complete insertions (p < 0.001, Mann–Whitney U test), but was more accurate when compared with human operators as it made fewer attempts (88% robotic vs. 79% human first attempt success; p = 0.046, chi-squared test). Times for trans-Atlantic robotic needle insertion (median = 59 s) were comparable to times taken for local robotic needle insertion (median = 56 s) with no difference in accuracy. Conclusion: Telerobotics is an accurate and feasible tool for future minimally invasive surgery.

Treatment of Urolithiasis in the Morbidly Obese

Background: Morbidly obese patients with urolithiasis present a therapeutic and diagnostic challenge to the Urologist. Management is reported and potential difficulties discussed. Methods: Morbidly obese patients (body mass index ≥ 40kg/m2) with stone disease were identified by retrospective review. Stone load was calculated and treatment modalities noted. Results: 18 renal units (kidneys) were treated in 17 patients. Of these, 2 required no treatment, 2 had open procedures, and 15 were treated with flexible ureteroscopy. Mean stone burden in patients treated with flexible ureteroscopy was 18 mm, but 8 patients had stone loads >15 mm and in these patients mean stone burden was 23 mm. All were successfully treated or rendered asymptomatic. There were no major complications. Conclusion: Obesity is increasingly prevalent and associated with a high incidence of co-morbidity and complications. Imaging can be difficult and treatment options are limited. Flexible ureteroscopy has proven to be the most successful treatment option, and can avoid the need for more invasive procedures. Furthermore, stone loads greater than normally acceptable can be successfully undertaken in these patients, and should be attempted due to problems associated with other techniques.

Management of Cystinuric Patients: An Observational, Retrospective, Single-Centre Analysis

Objective: A critical appraisal of the management of patients with cystine stones treated in our unit in the past 6 years and to analyze the outcome of multimodality therapies. Study Design: An observational, single-centre retrospective study. Methods: We reviewed the records of all patients with stones referred to our centre over a 6-year period from 1998 to 2005. Data recorded included demographic details, medical therapies received/prescribed, compliance with medical therapies, mode of treatment, stone clearance and any recurrence during this period of study. Results: A total of 30 cystinuric patients were treated in our institution over the period of 6 years from 1998 to early 2005. Of these 16 were males and 14 females with an average age at last follow-up of 39 years (range 15–70). Two patients were successfully managed medically. The remaining patients (n = 28) underwent a total of 237 procedures (pre- and postreferral to our unit), with an average of 7.9 procedures per patient for 126 stone episodes (4.2 episodes/patient). The modes of treatment included extracorporeal shockwave lithotripsy (n = 143), ureterorenoscopy and intracorporeal lithotripsy (n = 50), percutaneous nephrolithotomy (n = 28) and open procedures (n = 16). Two patients needed open surgery at our unit. Prior to referral to our dedicated unit, patients had received treatment with extracorporeal shockwave lithotripsy (multiple sessions), ureteroscopy (n = 14), percutaneous nephrolithotomy (n = 4) and open stone removal (n = 14). Most of the stones at our unit were managed using minimally invasive therapies. Conclusion: Compliance of cystinuric patients with medical treatment is often poor and patients experience recurrent stone episodes requiring multiple interventions. Modern management of cystine calculi should be with staged minimally invasive procedures to avoid the complications of multiple open procedures wherever possible along with appropriate medical prophylaxis.

Lower ureteric obstruction: a complication of tailed ureteric stents

MAG-3 diuretic renography was equivocal, with prompt excretion after frusemide, suggesting no significant obstruction. During this time he was producing >6 L of urine per day, but his creatinine remained high, at a mean (range) of 480 (301–796) m mol/L for this 4-week inpatient stay. This urine output combined with the imaging findings militated against an obstructive cause. Finally, with no improvement despite the above measures, he underwent a retrograde ureterogram and was found to have a lower ureteric stricture 2 cm from the ureteric orifice. His tailed stent was changed for a 7 F Percuflex JJ stent (Boston Scientific). His creatinine level improved immediately to 270 m mol/L the day after the stent change, and returned to normal (110 m mol/L) after 5 weeks. Two months later the stricture was dilated and after a further 6 weeks of JJ stenting, the stent was removed. The ureter was widely patent on retrograde ureterography. His creatinine level has remained normal for over a year since removing the stent.