Clinical Cases - Urinary System
During a football game between two arch rivals, the wide receiver of one team was involved in a pass pattern across the middle of the field. The quarterback was being rushed and threw the pass high. The wide receiver leapt to catch the pass and just as he did so he was "sandwiched" between the cornerback and free safety. The two defensive players hit the receiver just below the ribs on the left side, one in front and one from behind. The receiver managed to hang on to the ball but crumpled to the turf in pain. At first it was thought that he was just "shaken up," but the pain in his flank continued and became more severe. He was taken to the emergency room and examined. His vital signs were slightly elevated, but within normal range. Plain film X-rays showed no broken bones, but the margin of the left psoas major muscle was not distinguishable. Urinalysis showed blood in his urine. An IVP and CT scans were done. The IVP showed leakage of contrast into the tissue immediately around the kidney. The hemorrhage was confined to the area immediately around the kidney and extended medially toward the abdominal aorta. The diagnosis was that the kidney had been lacerated or ruptured. Immediate surgery was performed to close the laceration. The player's season ended, but he recovered uneventfully.

Questions to consider:
  1. Where is the left kidney located in reference to the vertebrae, ribs, and psoas major muscle?
    The left kidney is located in the left paravertebral gutter, its hilum facing anterior and medially, against the psoas major muscle. The psoas major slopes laterally as it descends and therefore the lower pole of the kidney is more lateral than the upper. The 11th rib crosses the upper pole of the left kidney and the 12th rib crosses it just above the hilum. The liver pushes the kidney down somewhat so that the right kidney is slightly lower.

  2. What is flank pain and why did it occur there?
    The flank is the lateral-posterior portion of the abdomen between the costal margin and iliac crest. Pain from the kidney is usually referred there.
  3. Why was the margin of the psoas major muscle not visible?
    Normally the lateral margin of the psoas is visible on a plain film because it is of water density and immediately lateral is found fatty tissue of less radiodensity. The hemorrhage is of water density (same as the muscle) and therefore obscures it.
  4. How did blood get into the urine?
    The laceration of the kidney must have involved part of the urinary collecting system and the blood flowed to the bladder with urine.
  5. What is an IVP?
    An IVP is an intravenous pyelogram. Iodinated contrast is injected into a cutaneous vein and travels to the kidney where it is concentrated and excreted in the urine. Since the kidney was ruptured the arterial blood leaked into the surrounding tissues and was visible.
  6. What confined the hemorrhage to the area around the kidney?
    The kidney is surrounded by a perirenal fatty capsule, the renal (Gerota's) fascia and pararenal fat. The fat offers no resistance to the hemorrhage, but it was contained in the renal fascia. The renal fascia extends toward the midline and therefore blood was directed toward the abdominal aorta, thus obscuring the margin of the psoas muscle.
  7. Where would be the best place to make a surgical incision to expose the kidney without going into the peritoneal cavity?
    Incisions to expose the kidney are usually done in the flank area, just below (and sometimes in the bed of the rib - the rib actually being removed) the 12th rib and just lateral to the deep back muscles. Whenever possible surgeons like to stay out of the peritoneal cavity, thus avoiding adhesions, ileus and other complications. Since the kidney, ureter and all its blood vessels are retroperitoneal, the flank approach allows good access to the kidney and stays out of the peritoneum.
A twenty-six year old male presents to the E.R. after a motorcycle vs. car accident. The patient is awake and alert, and reports pain in his abdomen and pelvis. On physical examination you note that his vital signs are: heart rate 120, blood pressure 120/60, respiratory rate 30. Examination also reveals abrasions on his abdominal wall surface and no signs or presence of blood on his external urethral meatus. Palpation reveals generalized tenderness over the entire abdominal region. In addition, the patient shows particular discomfort when you attempt to assess the stability of his pelvis by placing your hands over his pubic symphysis and laterally applying pressure over the iliac blades. He does not have full hip extension and rotation when you assess his mobility while laying on the exam table. Rectal exam is negative for gross blood, and the patient has a normally placed prostate.

You then order x-rays of the pelvis in 3 planes (AP, lateral, and oblique views) to determine if the patient has a fractured pelvis and a flat plate of the abdomen to determine if the patient has free air in his abdomen. A diagnostic supraumbilical peritoneal lavage turns out negative. You suspect internal bleeding due to the abdominal pain, so you order an angiogram to locate the source. You diagnose a pelvic fracture, complicated by internal bleeding.

The patient is taken to angiography where a laceration of the internal pudendal artery is found, and a selective embolization is performed. External fixation of the pelvis is performed after the bleeding has been stabilized. Urology has been consulted to ascertain if there was any urethral injury.

Questions to consider:
  1. What are the diagnostic features of a fractured pelvis ?
    Demonstrated instability of the pelvic ring can occur via a fracture of the two innominate bones which join the sacrum to form the pelvis. Stability of the pelvic ring is based in large part by ligamentous attachments: anteriorly, the pubic portions are joined by the pubic symphysis and posteriorly they are attached to the sacrum by strong posterior and anterior sacroiliac ligament. These ligamentous attachments themselves can be displaced.

    X-rays of the pelvic region with a suspected pelvic fracture would include a view of the pelvic inlet arranged to view cephalad to caudad for a view of the anterior to posterior view (and includes pubic symphysis and sacroiliac joint dislocations). Pelvic outlet views are also performed obliquely in caudal to cephalic direction and obtain views of any vertical instabilities or sacral body fractures. In addition, standard AP and lateral views allow visualization of the innominate bones.
  2. What vessels branch off the internal iliac artery?
    The common iliac artery bifurcates into an external and internal iliac artery. The internal iliac artery is known as the "pelvic artery" and provides the blood supply to most of the pelvic structures. The branching pattern of the internal iliac artery is highly variable, but the most common pattern is for the artery to split into anterior and posterior divisions.

    Posterior division, in order: Anterior division, in order:
  3. What procedure would the urologist use to determine if the patient had urethral injury?
    A diagnostic technique would be a retrograde urethral cystoscopy using contrast to ascertain if there is a tear in the membranous or spongy regions of the urethra.
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