OBJECTIVESTo evaluate holmium:YAG laser vaporization of papillary tumours of the bladder, focusing on surgical technique, patients’ satisfaction, complications and cost‐effectiveness when using the technique under local anaesthesia as an outpatient procedure.PATIENTS AND METHODSIn all, 52 consecutive patients with recurrent papillary tumours of the bladder were scheduled for holmium:YAG laser vaporization under local anaesthesia using a flexible cystoscope. The number of papillomas and total operative duration was recorded. Patients and surgeons were asked to complete a questionnaire about the procedure.RESULTSIn all, 197 papillomas were successfully vaporized in 88 operations, with a median operative duration of 15 min (5 min per papilloma) and no patient needed treatment under general anaesthesia. Most patients (86%) had no pain (as reported during standard cystoscopy) and none of the procedures was stopped because of pain. All patients would undergo the treatment again, compared with a standard transurethral resection of bladder tumour. The five surgeons rated the procedure as easy in most patients (78%) and difficult in a few (6%). The total cost for the outpatient procedure was less than that for standard treatment.CONCLUSIONThis study clearly indicates that holmium:YAG laser vaporization of superficial bladder tumours is feasible, easy and fast, with a high degree of patient satisfaction, and it seems to be an attractive alternative to standard treatment. The procedure has some clear positive socio‐economic perspectives in both the short‐ and long‐term.

The renal pelvis pressure flow relationship of 40 normal pig upper urinary tract was investigated. During standardized studies it was disclosed that the resting pressure has a normal distribution with wide 95% confidence limits (0.3-14.7 cmH2O). When perfusion was introduced, pelvic pressure increased, the normal distribution was lost, and the 95% confidence limits were broadened to more than 30 cmH2O. A normal distribution was regained at higher flow rates. The mean increment beyond 8 ml/minute was small, only 3.7 cmH2O from 8 ml/minute to 20 ml/minute. The wide variation found in pressure responses to high flow rates and the spread of pressures at higher flow rates imply major difficulties in distinguishing, between normal and abnormal pressure flow relationships in renal pelvis.

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The pressure-flow relationship of the normal pyeloureter was investigated in 10 pigs. From a mean baseline pressure in the pelvis of 7.5 cm H₂O, the pressure increased during perfusion. The pressure increase from baseline to 8 ml/min was significant. It was noticeable that a perfusion rate of 8 ml/min resulted in intrapelvic pressures of more than 27 cm H₂O in 4 of the 10 pigs. A further increase in perfusion rate gave only a slight, additional increase in pressure with linear relationship between flow rate and pressure. The steep rise in pressure from baseline values to 8 ml/min and the slight additional increase in pressure hereafter was probably caused by a transformation of peristalsis to a continuous flow.

The lowest pressure of urine transport was investigated in 12 pig pyeloureteral units. The investigation was performed in general anaesthesia with two catheters placed transparenchymically in renal pelvis – one for pressure registration and one for drainage. The baseline pressure in the pelves was established during a control period of 10 min. When the pressure in pelvis was lowered by means of drainage, ureteral activity and bolus transport was abolished. During a gradual increase of the resistance to drainage urine transport through ureter re-occurred. The pressure of recurrence was in all cases but one the same as the baseline pressure within a difference of 2 cm H₂O. The minimal pressure of transport is an important parameter in characterizing pelviureteral dynamics and according to the present study this minimal pressure is reproducible in the single pig pyeloureter.