Percutaneous nephrolithotomy: advances in equipment and endoscopic techniques.

Over the last two years there has been a 30-per cent increase in our success rate for percutaneous nephrolithotomy. A significant reason for this has been advances in endoscopic equipment. We describe our new lightweight nephroscopes and how they may be used in combination with the Amplatz sheath. Seventeen patients who were successfully treated by electrohydraulic disintegration are reported. We believe this method to be preferable to ultrasonic stone destruction in most cases. The first report of the clinical use of bipolar diathermy for intrarenal endoscopy is described.

Optical triradiate nephroscope: new concept in percutaneous renal surgery.

We have been disappointed by the high residual fragment rate following electrohydraulic and ultrasonic stone disintegration during percutaneous renal surgery. As a result the optical triradiate nephroscope (Wickham/Miller, Karl Storz GmbH) has been developed to allow the extraction of calculi in the range of 0.8 mm to 1.5 cm intact. The grasping jaws of the instrument provide a vice-like grip from which the stone will not dislodge during extraction. This endoscope should be included in any basic kit for percutaneous renal surgery. It has proved invaluable both for one-stage and two-stage cases. Techniques and principles of triradiate grasping are reported.

Intrarenal access.

Corrosion casts were made of 27 human cadaveric kidneys. The anatomy so displayed suggests that to avoid intrarenal vascular damage, incisions for nephrolithotomy should be radial, peripheral and, wherever possible, posterior.

Integrated cystoscope: first rigid multipurpose operating cystoscope for local anesthetic endoscopy.

The Miller Integrated Cystoscope is the first small-diameter (17 Ch), rigid, multipurpose, operating cystoscope (biopsy, urethrotomy, ureteric catheterization, cutting, retrieval of stones and foreign bodies, and injection) designed with patient comfort in mind. Despite a small outside diameter, the 8.7-Ch instrument channel conducts a 7.5-Ch accessory including the unique rigid Endoknife, which converts it into an optical urethrotome and rigid Endoneedle which can deliver local anesthetic and other pharmacologic agents into the bladder, prostate, and urethra of both male and female patients. The simplicity of design has dispensed with the need for more costly and conventional instrumentation (e.g., optical urethrotome, Albarron lever) at a fraction of the cost. The urologist can not only inspect the lower urinary tract (Cf fiberscopes) but also perform endoscopic procedures short of a full transurethral prostatectomy with maximum patient comfort.

Extrusion of calculi from upper urinary tract into perinephric and periureteric tissues during endourologic stone surgery.

We report on 11 patients in whom fragments of calculi were extruded into the perinephric or periureteric tissues at the time of endourologic stone surgery. All patients have been managed conservatively. In 2 patients ureteric strictures developed, but these were probably secondary to an electrical injury as a result of electrohydraulic lithopaxy. The remaining 9 patients have not experienced serious sequelae as a result of the calculus extrusion.

Explosive nephrolithopaxy: reality or fiction?

The use of silver and lead azide explosive charges for the percutaneous distintegration of renal calculi has been investigated. Charges of 10 mg or more reliably reduced calculi to fragments of extractable size; however, the concomitant tissue effects would preclude the use of such charges clinically. Smaller charges require multiple applications. High-speed flash photography demonstrated the unfocussed nature of these discharges. Considerable improvements are anticipated when the shock waves are focused. The use of Nonel tubing is described, and future developments are discussed.

A computer-based technique for measurement of renal parenchymal area on intravenous urograms.

Accurate measurement of the renal parenchymal area of intravenous urograms is discribed using a graphic tablet with a pressure-sensitive surfact linked on-line to a computer. The area outlined on the tablet is immediately computed and shown in square centimetres on a television screen and on a data print-out. The renal areas of 22 patients' urograms were studied before the three months after renal stone removal under local hypothermia. Renal function was measured by creatinine clearance. Conventional measurements of renal length, width and area were also performed for comparison. Results confirmed that while overall kidney size was reduced following operation, the parenchymal area and creatinine clearance were unaltered. This computer-based technique is simple to perform, quick and accurate, and provides quantitative information on intravenous urograms.

An introduction to minimally invasive therapy.

Minimally invasive therapy (MIT) has as its basic premise the reduction of iatrogenic trauma to the patient by surgeon, physician or radiologist. This approach must also imply that the therapeutic procedure succeeds in its aim of cure in a manner no less effective than is currently achievable by established methods of treatment. Acceptance of this principal has many identifiable sequelae, including profound changes in hospital design, increasingly expensive technological instrumentation, more sophisticated teaching and learning patterns, and a massive redirection of health care financial resources. These changes cannot be contemplated at leisure, because they are dynamically imperative and progressing with relentless rapidity, being directly driven by the consumer. It is vital that this shift in clinical emphasis should be appreciated so that future planning can be undertaken with some rationality.

Extracorporeal shockwave lithotripsy, endourology and open surgery: the management and follow-up of 200 patients with urinary calculi.

The management and follow up of 200 consecutive patients with renal and ureteric calculi are presented. The primary treatment of 185 (92.5%) was by extracorporeal shockwave lithotripsy (ESWL), of whom three (1.6)%) with large calculi underwent percutaneous nephrolithotripsy (PCNL) prior to ESWL as a planned combined procedure. Twelve (6%) were treated by PCNL or ureterorenoscopy (URS) as their definitive treatment and three (1.5%) by conventional open renal and ureteric surgery. The average in-patient stay was 3.8 days and most returned to normal activity within one day of discharge. Of the 185 patients 102 (55%) required no analgesia after treatment by ESWL, 29 (15.6%) required parenteral analgesia and the rest were comfortable with oral non-narcotic medication. Thirty (16%) required auxillary treatment by percutaneous nephrostomy (PCN), PCNL and URS following ESWL for obstructive complications from stone particles. Two required further ESWL and one PCNL at three months for large fragments. Overall, open surgery was required for only 1% of renal calculi and 13% of ureteric stones. These results are consistant with the extensive West German experience confirming that most urinary calculi are now best managed by ESWL and endoscopic techniques. Where these facilities are available open surgery should only be necessary for less than 5% of upper urinary tract stones.

The development of a surgeon robot for prostatectomies.

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.

The Probot--an active robot for prostate resection.

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.

Hydrophilic graft copolymers: a new concept in urological surgery.

Hydrophilic graft copolymers are derived from hydrophobic polymers which have been copolymerized and then grafted by radiation initiation so that they become hydrophilic. Tubes of such material expand in diameter by 60% when wet and become slippery. The first medical applications of these materials are described: they have been used as an access conduit for percutaneous renal surgery and endoscopic access to the ureter.

The development and application of a new surgical device--the Endoscopic Liquidiser and Surgical Aspirator (ELSA).

Modern surgery is looking for ways to carry out procedures which limit unnecessary damage to the patient. This means, in practice, using smaller incisions and special tools. An instrument for removing tissue through a small cross-section has been developed. It is suitable for both endoscopy and laparoscopy. The instrument and its development is described, and its performance evaluated in vitro and for a range of clinical procedures. Experiments aimed at uncovering the mechanism of cutting are discussed as to their relevance for practical instrument development.

Treatment of urinary tract stones.

Replacement of open surgery with minimally invasive techniques for treating stones in the renal tract has greatly reduced patients' morbidity and mortality and the period of hospitalisation and convalescence. Extracorporeal shockwave lithotripsy does not require anaesthesia and requires little analgesia so that treatment can be given on an outpatient basis, and there is no wound to heal. Only a small puncture site is needed for percutaneous endoscopic lithotomy, and with the advent of prophylactic antibiotics there are few complications. Of renal stones, about 85% can now be successfully treated by extracorporeal lithotripsy alone, and almost all of the stones too large or hard for lithotripsy can be treated endoscopically, with ultrasonic or electrohydraulic probes being used to fragment the stone. Stones in the upper and lower thirds of the ureter can be treated by extracorporeal lithotripsy, but stones in the middle third, which cannot normally be visualised to allow focusing of the shockwaves, usually require ureteroscopy. Nearly all bladder stones can be treated by transurethral endoscopy with an electrohydraulic probe. Only the largest renal tract stones still require open surgery.

Minimally invasive surgery. Future developments.

The rapid development of minimally invasive surgery means that there will be fundamental changes in interventional treatment. Technological advances will allow new minimally invasive procedures to be developed. Application of robotics will allow some procedures to be done automatically, and coupling of slave robotic instruments with virtual reality images will allow surgeons to perform operations by remote control. Miniature motors and instruments designed by microengineering could be introduced into body cavities to perform operations that are currently impossible. New materials will allow changes in instrument construction, such as use of memory metals to make heat activated scissors or forceps. With the reduced trauma associated with minimally invasive surgery, fewer operations will require long hospital stays. Traditional surgical wards will become largely redundant, and hospitals will need to cope with increased through-put of patients. Operating theatres will have to be equipped with complex high technology equipment, and hospital staff will need to be trained to manage it. Conventional nursing care will be carried out more in the community. Many traditional specialties will be merged, and surgical training will need fundamental revision to ensure that surgeons are competent to carry out the new procedures.

Percutaneous cholecystolithotomy: the first 60 patients.

OBJECTIVE: To assess the feasibility and possible complications of percutaneous removal of gall stones. DESIGN: Prospective study of the first 60 patients treated. SETTING: The London Clinic. PATIENTS: 60 Consecutive patients with symptomatic gall stones who agreed to have them removed percutaneously. RESULTS: 56 Patients had stones successfully removed percutaneously. In four patients failure of access necessitated a cholecystectomy under the same anaesthetic. Two patients had an empyema of the gall bladder drained initially, followed by a second operation to remove the stones one week later. Seven patients had postoperative complications, and two had recurrences of biliary calculi. CONCLUSIONS: The techniques and instruments used in percutaneous nephrolithotomy can successfully be adapted for percutaneous removal of gall stones. The procedure is suitable for a wider range of patients than other techniques that leave the gall bladder intact.