A stone in the ureter nearly always has its
birth in the kidney. Most are single small stones which pass spontaneously.
Clinical
features
The presence of a stone passing down the
ureter often causes intermittent attacks of ureteric colic.
Ureteric colic
A stone in the upper ureter produces symptoms
identical with those of a stone blocking the pelviureteric junction. As the
stone progresses to the lower ureter, the waves of agonising pain are
typically referred more to the groin, external genitalia and the anterior
surface of the thigh. In a man, the testis may be retracted by spasm of the
cremaster and tenderness may persist for some days after the colic has ceased.
When the stone is in the intramural ureter, the pain is referred to the tip of
the penis. In both sexes there may be strangury.
Impaction
Most stones pass spontaneously from the ureter
but there are five sites of anatomical narrowing where the stone may be arrested
(Fig. 64.28). When the stone becomes impacted the attacks of colic give way to a
more consistent dull pain, often felt in the iliac fossa. The pain is increased
by exercise and lessened by rest. Distension of the renal pelvis due to obstruction may cause pain and discomfort in the loin.
As time goes by the stone may become imbedded as the adjacent ureteric wall
becomes eroded and oedematous due to pressure ischaemia. Perforation of the
ureter and extravasation of urine is a rare complication.
Severe
renal pain persisting for 1 or 2 days and then subsiding suggests that the
ureter is completely obstructed by the stone. If urography (IVU) or
ultrasonography suggests that obstruction persists after 1—2 weeks, the
calculus should be removed because prolonged distension of the kidney will lead
eventually to atrophy of the renal parenchyma.
Haematuria
Almost every attack of ureteric colic is
associated with microscopic haematuria which lasts for a day or so. More
profuse bleeding is uncommon and should raise the suspicion that the colic is
due to passage of a clot.
Abdominal
examination
There is tenderness and some rigidity over
some part of the course of the ureter. The principal difficulty on the right
side is to distinguish symptoms and signs of ureteric colic from those of acute
appendicitis or acute cholecystitis. The presence of haematuria does not rule
out appendicitis, because an inflamed appendix lying near the ureter can give
rise to a local ureteritis which will result in some red cells in the urine. In
practice, the patient with acute renal colic is usually in greater pain and less
systemically ill.
Imaging
Most urinary calculi are radiodense and
visible on a plain abdominal radiograph. The stone may not be seen along the
line of the ureter if it is very small or if it is obscured by contents of the
gut or the shadows of nearby bones. An intravenous urogram performed while the
patient has pain can confirm the diagnosis. During and for some time after an
attack of renal colic there will probably be little or no excretion on the
affected side. Occasionally, there is an extravasation of contrast from the
dilated system. Late radiographs, taken up to 36 hours after the injection of
contrast, may show dilatation of the ureter down to an obstructing calculus. A
radiolucent uric acid stone may be demonstrated as a filling defect in the
contrast.
Analgesic
abusers occasionally simulate symptoms to obtain drugs and the urogram is useful
in excluding renal colic. If the urogram
is normal during an attack, the patient does not have renal colic.
Cystoscopy is not indicated routinely but may
reveal oedema and petechiae of the urothelium around the ureteric orifice when
the stone is in the lower ureter. The stone may be visible in the orifice as it
makes its passage into the bladder.
Retrograde
ureterography is usually performed as an immediate preliminary to an endoscopic
operation to remove a calculus but it may be of use if doubt remains after the
intravenous urogram.
Treatment
Pain
Nonsteroidal anti-inflammatory drugs such as
diclofenac and indomethacin have replaced opiates as the first line of treatment
for renal colic. The value of smooth muscle relaxants such as propantheline
(Pro-Banthine) is debateable.
Removal of the
stone (Table 64.5)
Expectant treatment
is appropriate for small stones that are likely to pass naturally. This may take
many months and, as long as the patient is not disabled by recurrent attacks of
colic, the progress of the stone can be followed by radiographs repeated every
6—8 weeks.
Endoscopic
stone removal. Dormia basket. The use
of wire baskets under image intensifier control has been replaced by
ureteroscopic techniques, but may be useful when the necessary instruments and
expertise are not available. There is a significant danger of ureteric injury,
and basketry under radiographic control should only be used for small stones
that are within 5 or 6 cm of the
ureteric orifice (Fig. 64.29).
Ureteric meatotomy. Stones often lodge in the intramural part of the
ureter. Careful endoscopic incision using a diathermy knife can enlarge the
opening and free the stone. The procedure may lead to urinary reflux but it is
rare for this to cause problems.
Ureteroscopic
stone removal. A ureteroscope is a long endoscope which can be passed
transurethrally across the bladder into the ureter (Fig.
64.30). The
ureteroscope is used to remove stones which are impacted in the ureter. Stones
that cannot be caught in baskets or endoscopic forceps under direct vision are
fragmented using an electrohydraulic, percussive or laser lithotriptor.
Push bang. A stone that is lying in the middle or upper part of the ureter can
often be flushed back into the kidney using a ureteric catheter. The
repositioned calculus is ‘secured’ in the kidney by a J-stent. The patient
can then be referred for
Lithotripsy
in situ. Provided the stone is in a
part of the ureter that can be identified by the imaging system of the
lithotriptor, it can be fragmented in situ.
This form of treatment is not appropriate if there is complete obstruction
or if the stone has been impacted for a long time.
Open surgery
Ureterolithotomy. A radiograph should be taken
to confirm the position of the stone immediately before surgery.
The
incision must be appropriate for the position of the stone. Calculi in the upper
third of the ureter are approached through a loin or upper quadrant transverse
incision as used for a stone in the renal pelvis. Access to midureteric stones
is through a muscle-cutting iliac fossa incision; lower ureteric stones are best
reached through a Pfannenstiel incision.
For stones close to the bladder exposure is
improved by ligating and dividing the superior vesicle vascular pedicle. The
ureter is exposed in the retroperitoneum and slings are applied above and below
the calculus to stop it from migrating from the operative field. The ureter is
incised longitudinally, directly on to the stone, which is freed from adhesions
by blunt dissection, and removed with stone forceps. Soft catheters are passed
upwards and downwards to ensure that the ureter is clear. The ureterotomy is
closed with interrupted absorbable sutures and a drain left in place for a day
or so to drain urine leakage.
Idiopathic
retroperitoneal fibrosis
This is a rare condition in which one or both
ureters become bound up in a progressive fibrosis of the retroperitoneal
tissues. The cause is unknown although some cases may be drug related. A similar
clinical picture occurs in patients with leaking aortic aneurysm and
infiltrating retroperitoneal malignancy.
The
patient complains of backache which is unremitting for several months. The onset
of anuria and renal failure prompts investigation of the renal tract which
reveals hydronephrosis. The excretion urogram typically shows displacement of
the obstructed ureters towards the midline and the appearances on CT are
diagnostic. The sedimentation rate is markedly raised.
Treatment.
It may be possible to insert ureteric stents as a temporary measure while renal
function recovers. If not, percutaneous nephrostomies will allow the obstructed
kidneys to drain. Some patients need renal replacement by dialysis. Some
advocate that these patients should be treated conservatively with high-dose
steroids. Surgical treatment involves careful dissection of the ureters from
their entrapment (ureterolysis). Wrapping omentum around the freed ureters make
recurrent obstruction less likely.