Ureteric stones

The stone that obstructs a patient's ureter originates in his kidney. Once it is free in his renal pelvis, it may pass into his ureter, and it can stick anywhere, but it is most likely to stick: (1) at his pelviureteric junction, (2) in the upper or (3) in the lower third of his ureter, or (4) at the entry of his ureter into his bladder. A stone is usually rough, so that some urine can usually leak past it to begin with. Later, obstruction becomes complete, so that after some weeks or months, he develops a hydronephros or a hydroureter, which may become infected.

As the stone passes down his ureter, it causes severe ureteric colic[md]even a tiny one causes agony. He has a sudden severe pain in his loin, radiating to his groin, perineum, and testis (or to a woman's labia). He vomits, sweats, and rolls about to get relief. If, at the same time, his urine is infected, he has fever and rigors. His urine may be ''smoky', but is seldom grossly blood-stained. He may be slightly tender in the area of the referred pain, and he may have had attacks like this before. If his stone impacts, the severe pain of ureteric colic gradually subsides.

There is an 85% chance that his ureteric stone will be passed into his bladder, and then out through his urethra. So give him plenty of fluids, and treat his pain.

Don't try to remove a stone from the renal pelvis. This has to be done through a lumbar incision, as for a nephrostomy (23.13); the undilated pelvis is difficult to isolate, and you can easily injure important blood vessels. You can however remove a stone from the middle third of the ureter extraperitoneally, as described below. Ideally, a stone at the lower end of the ureter should be removed with a cystoscope and a Dormia basket, which is difficult and expensive, and needs a modern cystoscope. If you cannot do this, or have tried and failed, you can remove the stone extraperitoneally at open operation, as described below.

URETERIC STONES SPECIAL TESTS. There are red cells in the patient's urine. A plain (''KUB') film may show the stone. Often, it does not, because he has an associated ileus, and his distended gut obscures it. Look for it along the course of his ureter, as this crosses the tips of the transverse processes of his lumbar vertebrae, runs over his sacroiliac joint, and descends in a gentle arch to a point just medial to his ischial spine, whence it turns medially to enter his bladder. Here, you can easily mistake a stone for a phlebolith. Most ureteric stones are slightly elongated.

If the diagnosis is in doubt, and you want to exclude some disease, such as appendicitis, which requires an urgent operation, take an intravenous urogram at the time of the pain. Otherwise it is unnecessary. Take a film soon after injecting the contrast medium, another at one hour, and a further one at 1[1/2] hours, after he has emptied his bladder, so that contrast medium does not obscure the lower end of his ureter. The delayed excretion of contrast medium into his renal pelvis and dilatation suggest a stone. If they are not present at this stage, take further films at 3, 12, and possibly 24 hours. A totally normal urogram during the presence of pain excludes a diagnosis of ureteric colic.

THE DIFFERENTIAL DIAGNOSES include: (1) Appendicitis (for which an intravenous urogram is often necessary). (2) Ovarian causes. (3) Salpingitis. (4) Colic due to the passage of blood clot in the ureters, resulting from trauma, or a neoplasm.

MANAGEMENT. Leave a stone of [lt]5 mm to pass spontaneously, unless there is some complication. A stone of [mt]5 mm is less likely to pass.

An impacted stone may remain in the ureter for weeks or even years, with contrast medium flowing past it and no upper urinary tract dilatation. There is no immediate need to remove a stone which is causing neither symptoms nor harm.

NON-OPERATIVE TREATMENT. Relieve his pain with pethidine (not morphine, because it causes spasm of the smooth muscle of the ureter), intravenously if necessary. Also give him atropine. Repeat these as required. Give him plenty of fluid, a tablet of frusemide 40 mg, and encourage him to walk about. Strain his urine to look for the stone. Repeat the plain X-rays on alternate days.

INDICATIONS FOR SURGERY. (1) Symptoms persist, and serial X-rays taken at 6 to 8 week intervals show that a stone of 5 mm or more is impacted (if it is not causing symptoms or obstruction, it does not necessarily have to be removed, but it is desirable to do so, and there is more time for referral). (2) Pain comes and goes over days or weeks without any further descent of the stone. (3) An intravenous urogram shows a hydronephrosis or a hydroureter, or no excretion of contrast medium. (4) Infection supervenes with fever, chills, rigors, pyuria, and toxaemia.

If possible, refer him; removing a stone from his ureter is not an immediately life-saving procedure, and it can be difficult. If you cannot refer him, proceed as follows.

X-RAYS. Take a plain X-ray of his abdomen just before you operate to make sure that the stone has not moved.

ANAESTHESIA. (1) General anaesthesia using intubation and a relaxant. (2) Subarachnoid (spinal) anaesthesia.

THE RENAL PELVIS OR UPPER THIRD [s7]OF THE URETER This is difficult surgery. Refer him. If you cannot refer him quickly, do a nephrostomy.

FROM THE MIDDLE THIRD [s7]OF HIS URETER Lay him supine. Start your incision at McBurney's point (A, 23-18), and carry it laterally for 7 cm parallel to his inguinal ligament. Divide his subcutaneous tissues, and his external oblique aponeurosis in the direction of its fibres; divide his internal oblique in the same direction. Divide his transversalis fascia, and sweep his peritoneum medially, until you reach the inner margin of his quadratus lumborum muscle, and the bifurcation of his common iliac artery into its internal and external iliac branches (3-7, 20-16). You will see his ureter lifted up by his peritoneum. Don't injure his spermatic vessels, which lie lateral to his ureter.

Feel for the stone in his ureter. Carefully pass a long Lahey forceps round his ureter, and pass two fine rubber catheters, or tapes, above and below the stone. This will prevent it slipping upwards or downwards. Cut longitudinally on to the stone with a No. 15 blade. Remove it carefully with Desjardin's forceps. Wash the area free of grit with warm saline. Pass a small rubber catheter up into his kidney, and down into his bladder, to make sure that no other stones are left behind.

Leave the ureteric incision open. Place a No. 12 Malecot catheter near this site, and bring it out through a separate stab incision. Close the abdominal incision in layers, using interrupted chromic catgut for the muscle, and monofilament for his skin. Connect the catheter to a closed drainage system.

CAUTION ! Make sure you find the stone and encircle his ureter above the catheter. If it slips upwards into his kidney, don't try to remove it by extending the incision, or using a traumatic instrument. Close the incision and refer him.

POSTOPERATIVELY, the catheter will drain up to 1000 ml of urine daily, but the volume will gradually diminish. By the 7th day his ureteric incision should have closed, and drainage ceased. If the volume draining remains undiminished, there is an obstruction in his ureter distal to the site of the incision, or it is diseased locally. Wait another week, and refer him.

FROM THE LOWER THIRD [s7]OF HIS URETER X-ray and anaesthetize him as above. Empty his bladder by passing a urethral catheter. Lay him supine, with a slight Trendelenberg position. There are two possible approaches. Remaining outside his peritoneum, which should be your aim, is easier in the first one.

Start your incision at McBurney's point and carry it medially parallel to the inguinal ligament. Incise his external and internal oblique, and open his transversalis fascia.

Or, (2) make a lower midline, or paramedian incision, starting at his pubis, and ending at his umbilicus. Incise his transversalis fascia (a transverse incision can also be used).

Carefully strip his peritoneum upwards with a gauze swab. Look for his ureter at the bifurcation of his common iliac vessels (Figs. 3-7 and 20-16) and follow it downwards to his bladder. It is crossed anteriorly by his vas deferens. You may have to divide his superior vesical artery so as to let you mobilize his bladder sufficiently to allow you see his ureterovesical junction easily.

Find the stone, and pass a rubber catheter under his ureter to prevent the stone slipping upwards. Make a longitudinal incision over it, and remove it carefully. Close the wound, leaving behind a rubber Malecot catheter connected to a closed drainage system as above. Care for him postoperatively as above.

DIFFICULTIES [s7]WITH URETERIC STONES If his ureteric colic goes, but THERE IS NO EVIDENCE THAT HE HAS PASSED A STONE, don't be surprised, this is not uncommon. It has probably passed without him being aware of it, especially if it is small.

If a stone becomes impacted at his pelviureteric junction, and HE ONLY HAS ONE KIDNEY, do a nephrostomy and refer him quickly.

If a stone is FIRMLY IMPACTED AT HIS URETEROVESICAL JUNCTION deep in his pelvis, try to squeeze it into his bladder or upwards into a more accessible part of his ureter where it will be easier to remove. Alternatively, make an incision 3 cm above the site of impaction, and try to remove the stone carefully with Desjardin's forceps.

Fig. 23-19 THE SUPRAPUBIC APPROACH TO THE BLADDER FOR THE REMOVAL OF A STONE. In this view you are standing on the patient's left side, so that his bladder appears upside down. A, the site of a Pfannensteil incision. B, displace the reflection of his peritoneum upwards. C, if you need to reflect his bladder upwards, you can divide his puboprostatic ligaments; most surgeons don't do this. D, hold his bladder in Allis' forceps and open it. E, the first step in closure. F, complete the second layer of sutures. Figure 23-21 shows the method of closure ]]in more detail. After Flocks RH and Culp DA, ''Surgical Urology', (4th edn 1975), Plates 69 and 70. Yearbook Medical, with kind permission.