162 J. REYNARD AND H. HASHIM
FIGURE 9.2. A computed tomography (CT) scan of the bladder showing the ureters entering posteriorly (outlined with contrast). The ureters enter the bladder just a few centimeters from the bladder neck and can easily be obstructed by locally advanced prostate cancer.
tomography (CT) scan may demonstrate evidence of retroperi-toneal and pelvic lymphadenopathy.
In cases of prostate cancer high-dose dexamethsone has been shown to result in an improvement in urine output and reduction in serum creatinine within 24 to 48 hours (Hamdy and Williams 1995). Give an 8-mg intravenous bolus followed by 4mg i.v. every 6 hours for 3 days, switching to oral dexamathasone thereafter. A reducing regimen can be used over the course of the next month.
9. UROLOGICAL NEOPLASTIC CONDITIONS PRESENTING AS EMERGENCIES 163
Where the patient is uraemic or has a rising serum potassium, more urgent treatment may be required. This can be in the form of percutaneous nephrostomy tube drainage, or if the patient is too unwell for this, acute haemodialysis.
In our experience attempts at retrograde JJ stent placement in the acute situation usually fail (it is impossible to pass a guidewire past the area of ureteric obstruction). A nephrostomy tube allows subsequent antegrade JJ stenting, and this may become the definitive management method, with the stents being changed every few months. In the case of prostate cancer, hormone treatment should be started (if not already done so), in the form of emergency orchidectomy or with antiandrogen blockade followed by a luteinizing hormone-releasing hormone (LHRH) agonist.
There are clearly issues related to the long-term prognosis of such patients. Patients with cervical and prostate cancer can survive for many months after presenting with ureteric obstruction, whereas the prognosis in patients with ureteric obstruction due to other cancers tends to be considerably shorter. Fallon and colleagues (1980) reported a median survival in prostate cancer patients treated with nephrostomy drainage for bilateral ureteric obstruction of 7 months post-nephrostomy insertion, and 55% of patients survived for over 1 year. For cervical cancer patients the average survival was 18 months. Bladder cancer patients did poorly, with a median survival of just 4 months after nephros-tomy drainage.