Stone - Lower (Distal)
There are three physiologic narrowing of the ureter where stones
may obstruct. The first narrowing of the ureter is the location
where the renal pelvis of the kidney meets the ureter or the uretero-pelvic
junction (UPJ). The next level of narrowing is where the ureter
crosses the iliac vessels. At this point, the diameter of the ureter
is narrowed to about 4 mm and urinary obstruction by a calculus
can commonly occur. The third ureteral narrowing exist where the
intramural portion of the ureter meets the bladder known as the
ureteral vesico-junction, or UVJ, which measures approximately 1
- 5 mm. in size. The majority of stones become stuck at this level.
Once a calculus reaches the distal ureter and approaches the bladder,
symptoms of vesicle irritation are frequently noted.
The usual manifestations of a kidney stone small enough to pass
into the ureter are ureteral colic and hematuria. This patient presents
with a stone in the upper ureter will frequently experience acute
onset of a sharp pain localized to the flank (side). As the stone
progresses downward to the level of the bladder, the pain remains
sharp and intermittent, corresponding to the ureteral peristalsis.
The pain will frequently radiate to the lateral flank and abdominal
area and may be accompanied by nausea and vomiting. If infection
accompanies obstruction, then the patient may develop fever and/or
chills associated with an infection of the kidney, also known as
the stone passes into the distal ureter, the pain remains sharp.
In males, pain may frequently radiate to the inguinal canal into
the groin and to the corresponding testicle. In females, the pain
may radiate to the ipsilateral labia.
is not uncommon for patients with ureteral colic to present with
nausea and vomiting. Abdominal distention due to a reflex ileus
may be present and may potentially confuse the diagnosis. These
symptoms may mimic the presentation of other disease processes,
including gastroenteritis, acute appendicitis, colitis, diverticulitis,
salpingitis, cholecystitis and bowel obstruction.
frequently, the passage of the stone may be less dramatic with patients
describing a dull ache in the flank (side) that may be present for
weeks without interfering with his or her routine. This pain is
not as localized as that of acute colic and may be confused with
patients may present with microscopic hematuria or gross hematuria
and/or a urinary tract infection (UTI).
the calculus reaches the distal ureter and approaches the bladder,
symptoms of bladder irritation, frequency, and nocturia may be present.
stone. Unenhanced CT scan shows stone in distal ureter (yellow
a stone can be visualized at the ureteral orifice
Ureteroscopy is a technique utilized for accessing the distal ureter
(see Figure a). Rigid or semi-rigid ureteroscopy is used to access
the ureter below the iliac vessels so that various lithotripsy options
are available for fragmenting stones (see treatment section of text).
In addition, shock wave lithotripsy can be used for distal ureteral
stones. This is done while the patient is placed in the prone position.
However, it should be noted that the success rate for distal ureteral
stones is less than the success rate for upper ureteral stones or