A new method of assessing urethral competence has been developed (Brown & Wickham 1969). It was originally devised to study the effect of electrical stimulation to the pelvic floor on the closure forces in the urethra. There seem to be applications of the technique in the study of incontinence and of strictures.The basic apparatus is an electric strain gauge manometer coupled to a pen recorder. This is used to record the pressure at the distal end of a single lumen urethral catheter through which a constant, but very slow, flow of water is forced by an infusion pump or a very high infusion bottle. The water forced through the catheter is expelled from the catheter eye against the urethral wall. The presure developed inside the catheter in order to o'rtrcome the wall pressure over the catheter eye, and the wall pressure itself can be shown to be very nearly equal.The flow of water is regulated to about 003 ml/sec by a standard infusion regulator situated on the water feed tube just distal to the point of pressure measurement. This flow rate is chosen for a compromise between the response time error, due to very slow flow rates, and the viscosity error due to higher flow rates. An advantage of this simple system is that fast response times (about 0O1 sec) will permit its use for continuous profile measurement. The catheter, calibrated in centimetres, is drawn slowly down the urethra and the recorder auto-40 matically plots the urethral wall pressure as a continuous graph. A complete profile takes about twenty seconds to make and a series of profiles can be plotted sequentially to trace the effect of electrical stimulation, chemotherapy, dilation or other surgery.

Sixty patients with idiopathic retroperitoneal fibrosis presenting between 1965 and 1984 are reviewed. Their mean age at presentation was 56 years and the male:female ratio was 3:1. The commonest presenting symptoms were flank and abdominal pain, weight loss, nausea and polyuria. Physical examination was usually normal, expect for the presence of hypertension. Anaemia and elevation of erythrocyte sedimentation rate were usually present. Proteinuria was found in less than a third of patients at presentation and significant bacteriuria was uncommon. The correct diagnosis was made or suspected in very few patients before referral. The cumulative actuarial survival rate was 86% at 1 year and 78% at 2 years. Seventeen patients died; they were significantly older and more uraemic at the time of referral than those who survived. A few patients did well with either corticosteroid therapy or ureterolysis alone. In the majority, both operation and steroid treatment were necessary. In bilateral obstruction with residual function in both kidneys, bilateral ureterolysis proved superior to unilateral operation (each followed by steroid therapy) in conserving renal function. Operation alone or steroid therapy alone should be considered in cases where steroids or surgery respectively present particular hazards. The less traumatic unilateral operation should be considered in poor risk patients and in those whose renal function is absent on one side. In many survivors, disease activity has persisted for many years. Life-long follow-up is recommended.

As men age, their prostates can enlarge, causing urinary difficulty. Surgery to correct this [transurethral resection of the prostate (TURP)] is a skilled and time-consuming operation requiring many repetitive motions of a cutter. A robot has been developed to perform these motions, relieving the surgeon of much of the burden of surgery. This robot has been tried both in the laboratory and later on human subjects and has proved itself capable of performing prostate resection. The Probot system consists of on-line imaging and three-dimensional prostate model construction, an appropriate surgeon-computer interface, a counterbalanced mounting frame and a computer controlled robot.

Upper tract pressure flow studies in four clinically unobstructed ureters with double J stents in situ indicated that urinary flow occurred mainly around the stent and that there was significant vesicorenal pressure transmission. This study examined the dynamics of ureteric urinary flow and morphological effects consequent upon stenting a ureter in vivo. In a porcine model, ureteric intubation caused a rise in intrapelvic pressures, hydroureter, vesicorenal reflux and generalised thickening of the ureteric wall with characteristic histological changes in the urothelium. These findings suggest that double J stents may compromise urinary drainage when ureteric obstruction is not present, urging caution in their use in the damaged, unobstructed upper urinary tract.

This study was designed to compare different methods of treating renal calculi in order to establish which was the most cost effective and successful. Of 1052 patients with renal calculi, 350 underwent open surgery, 350 percutaneous nephrolithotomy, 328 extracorporeal shockwave lithotripsy (ESWL), and 24 both percutaneous nephrolithotomy and ESWL. Treatment was defined as successful if stones were eliminated or reduced to less than 2 mm after three months. Success was achieved in 273 (78%) patients after open surgery, 289 (83%) after percutaneous nephrolithotomy, 301 (92%) after ESWL, and 15 (62%) after percutaneous nephrolithotomy and ESWL. Comparative total costs to the NHS were estimated as £3500 for open surgery, £1861 for percutaneous nephrolithotomy, £1789 for ESWL, and £3210 for both ESWL and nephrolithotomy. ESWL caused no blood loss and little morbidity and is the cheapest and quickest way of returning patients to normal life.

No abstract

The removal of prostatic tissue through transurethral resection of the prostate (TURP) is an operation that can require considerable skill from a surgeon as well as being a lengthy procedure. The potential for using robotic techniques was investigated in a preliminary feasibility study using a standard six axis 'Puma' robot. This led to the construction of a manually operated 'safety frame' which has been shown to be effective through clinical trials on 30 patients. A special-purpose robot, based on the design of the manual frame, has now been constructed. Some of the safety issues are discussed which make this procedure an ideal candidate for a robotic device.

Two hundred and fifty cases of percutaneous nephrolithotomy (PNL) are described. One hundred and fifty cases were treated in two stages, 100 in a single stage. The one-stage method has been shown to be as safe as the two-stage method but should be reserved for those with experience of the technique and who possess adequate instrumentation. PNL has proved to be a preferable option to open stone surgery and a useful alternative to extracorporeal shock wave lithotripsy (ESWL).