British Journal of Urology (1975), 41, 599-602 0

Nephroscop y PHILIP CLARK

Department of Urology, The General Infirmary and St James's Hospital, Leeds

Few urologists would operate upon a bladder without looking inside it first but how many will look inside a kidney?

This is the radiograph (Fig. 1) of a kidney exposed at operation. Many stones have already been removed, but this one small opacity remains. The surgeon is confronted with two problems. The first, what is the exact spatial position of that opacity? The second, is it a stone in the collecting system or calcification in the renal parenchyma? Although lateral X-rays or an operative pyelo- gram may help, it is difficult radiologically to be sure of the answer to either problem. On the other hand nephroscopy, the inspection of the interior of the kidney, might give the answer to both.

In nephroscopy the instrument is usually introduced through a pyelotomy to inspect the pelvis and the calyces of the kidney. This procedure is rather like performing cystoscopy on a bladder containing multiple diverticula and trying to examine the interior of each diverticulum. It can be done, but it is not easy. Alternatively, the instrument may be introduced through a nephrotomy into a calyx, when only that calyx and the pelvis can be examined. This method is particularly applicable after nephrolithotomy to make sure the calyx has been cleared of stone completely. In the first report of nephroscopy (Rupel and Brown, 1941), a panendoscope was ingeniously intro- duced into the kidney along a nephrostomy track by threading its sheath over the nephrostomy catheter which was then removed. The stone was seen with the panendoscope and was removed with Lowsley's forceps.

Over the last year I have been trying out various ways of performing nephroscopy and various instruments and the ones I have used have included the ordinary Storz infant panendoscope (Fig. 2) and the Storz nephroscope (Figs. 3 and 4). Occasionally with hydronephrotic kidneys I have used an adult-size panendoscope.

The actual technique of nephroscopy is remarkably simple. To obtain enough elbow room to work a good exposure is essential and I use the lateral approach through the bed of the last rib with the operating table fully broken. The kidney must be fully mobilised so that it can be rotated in both the horizontal and the vertical axes.

A wide incision is made in the renal pelvis. Some authors have suggested that only a small incision should be used and even that it should be made watertight around the nephroscope with a purse-string suture. This is quite wrong. With good irrigation an excellent view can be obtained even with the pelvis completely opened up, as for example by the incision made in doing a pyeloplasty.

The instrument is then introduced into the pelvis with the irrigation fluid running and is guided on under vision into the major and minor calyces of the kidney, in much the same way as a urethroscope is guided up the urethra under vision. By a combination of manipulation of the instrument and rotation of the kidney, it is often possible to introduce even a straight instrument into all the calyces of the kidney. The upper calyces are the easiest to enter but with suitable rotation of the kidney (it may have to be turned through 180") it is possible to examine even the lowest calyces.

The irrigation fluid should be run in by gravity as this is always safer than pressure irrigation. 1 Presented at the 29th Annual Meeting of the Canadian Urological Association in Ottawa, June 1974.

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Fig. 1. Radioeraph ,of a: kidney exposed at operation showing residual opacity in its lower pole.

Fig. 2. Storz infant panendoscope.

Fig. 3. Storz nephroscope.

Fig. 4. Tip of Storz nephroscope. Fig. 5. Sterile shield around eyepiece of Storz nephroscope.

To avoid the risk of introducing infection a special sterile shield (Fig. 5) can be fitted to the eye- piece or the surgeon can don a sterile hood, as described by Trattner (1948). It is probably sufficient, however, to place additional sterile towels around the wound before doing nephroscopy and to discard them immediately afterwards. The surgeon’s gown and gloves should also be changed.

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Fig. 6. Intravenous pyelogram of hydronephrotic kidney.

Comparing the two instruments, the straight Storz infant panendoscope and the right-angled Storz nephroscope, I found the ordinary infant panendoscope to be of greater value. Because of its smaller calibre, 10 Charritre, it can be introduced right into the minor calyces, even of a child’s kidney, whereas the wider nephroscope, 16 Charrih-e, usually sticks in their narrow necks. The advantages of being able to examine a minor calyx completely soon became very apparent. The dome of the pyramid could be examined, as if with a magnifying glass and the fornix all the way around it could be followed. Small particles of stone could sometimes be seen, which were not visible even on the X-ray of the exposed kidney. If all the calyces could be seen to be clear, the check X-ray too was usually clear and, if any calcification was seen on it, this represented calcifi- cation in the renal substance, such as a Randall’s plaque and not a stone in the collecting system. The position of a stone located with a straight instrument was immediately obvious, so that the panendoscope could be removed, the stone could be grasped easily with straight stone forceps and extracted, whereas the position of a stone located with a right-angled instrument was far less obvious-it had to be worked out.

Fig. 7. Plain Fray of the same kidney showing two small stones in its lower pole.

Figure 6 is the intravenous pyelogram of a hydronephrotic kidney which contained 2 small stones. Figure 7 is the plain X-ray of this kidney taken while the patient was on her way to the operating theatre and shows the stones lying in its lower pole. However, by the time this kidney had been mobilised the stones were no longer in its lower pole. They were easily located with the panendoscope in an upper calyx (Fig. 8) and were removed.

Nephroscopy is still in its infancy and its limitations must be clearly recognised. It is still im- possible with the instruments a t present available to see into some calyces. If there is much bleeding nothing can be seen. Because of this, the time to perform nephroscopy is before doing any operative procedure on the kidney, not afterwards. I have had no complications from nephroscopy; no kidney was damaged or infected. But obviously it is something which must be done gently and with care.

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Fig. 8. The same stones in an upper calyx.

What is the future of nephroscopy? The design of the instruments can be improved. For example, I would like to see a narrower Storz nephroscope, size 10 instead of 16 Charrihre, with a shorter right-angled limb, 2-5 cm instead of 4 or 6 cm. Flexible fibreoptic instruments offer great promise. The Olympus kidney fibrescope, which is narrow enough to be passed up the ureter and into the kidney is expensive, easily broken and, because of its fine calibre, the view through it is limited. On the other hand, the Olympus fibrescope for bronchoscopy can be used as a nephro- scope (Stuart, 1974) and its flexible, controllable tip would seem ideal for manoeuvring into calyces. The Storz nephroscope already has operating attachments and perhaps we can look forward to the development of renal lithotrites and resectoscopes.

Although much still needs to be done to improve the design of the nephroscope, nephroscopy will give valuable information often enough to be able to say it has progressed to being a worth- while procedure.

Summary

Nephroscopy is a simple and valuable procedure, which may be used to differentiate between stones within the calyces of the kidney and calcification in the pyramids and to locate stones and stone fragments.

The ordinary infant panendoscope is a suitable instrument to use.

Rimmer Bros. kindly lent me a Storz nephroscope to try out. The photographs were prepared by the Department of Medical Photography at the General Infirmary, Leeds. I would like to thank these kind people for their help.

References

RUPEL, E. and BROWN, R. (1941). Nephroscopy with removal of stone following nephrostomy for obstructive

STUART, A. E. (1974). Operative nephroscopy using bronchofibrescope. Journal of Urology, 111 , 9. TRAITNER, H. R. (1948). Instrumental visualization of the renal pelvis and its communications: proposal of a new

calculous anuria. Journal of Urology, 46, 177-1 82.

method; preliminary report. Journal of Urology, 60, 817-834.

The Author

Philip Clark, MD, MChir, FRCS, Consultant Urological Surgeon.