A 46-year-old man presents to the emergency department (ED) because of pain in his right lower quadrant (RLQ) that had a gradual onset beginning 4 hours ago. He describes the pain as sharp, severe, and constant. Initially, the pain radiated to his right flank but is now radiating into the right side of his scrotum. The patient reports feeling nauseous, but does not have any fever, chills, dysuria, or hematuria or any history of similar pain. There is no history of trauma. The patient's medical history is significant only for hypercholesterolemia; in particular, there is no history of abdominal surgery or urolithiasis.
{mosimage}On physical examination, the patient is clearly in severe pain. In bed, the patient is lying still but is grimacing and has visible discomfort with any movement. His vital signs show a blood pressure of 150/80 mm Hg, a heart rate of 98 bpm, a respiratory rate of 18 breaths/min, an oral temperature of 98.9°F (37.2°C), and an oxygen saturation of 98% while breathing room air.
{mosimage}The abdominal examination is notable for tenderness to palpation in the RLQ, with focal rebound tenderness and guarding. No pulsatile mass is appreciated in the midline position. Auscultation of the abdomen reveals hypoactive bowel sounds with no bruits. The genitourinary examination is negative for scrotal tenderness, erythema, or palpable masses; no urethral blood or discharge is noted. Mild tenderness is noted on palpation of the right costovertebral angle. The remaining findings from the physical examination, including the skin and cardiorespiratory examinations, are unremarkable.
{mosimage}The urinalysis reveals no white blood cells (WBCs), red blood cells (RBCs), nitrites, or leukocyte esterase. The patient's complete blood count (CBC) is within normal limits. To evaluate for suspected RLQ intra-abdominal pathologies, such as appendicitis, abdominal and pelvic computed tomography (CT) scans obtained with oral and intravenous (IV) contrast material are ordered (see Images 1-3).
What is the diagnosis?
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HINT
The patient does not have appendicitis.
Author:
Gil Z. Shlamovitz, MD, UCLA Emergency Medicine Center, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA
eMedicine Editors:
Erik D. Schraga, MD, Department of Emergency Medicine, Kaiser Permanente, Santa Clara Medical Center, Calif
Dinesh Singh, M.D., Assistant Professor of Surgery/Urology and Director of Endourology and Laparoscopy, Yale School of Medicine, Section of Urology, Department of Surgery, Yale-New Haven Hospital, New Haven, Connecticut
Rick G. Kulkarni, MD, Assistant Professor, Yale School of Medicine, Section of Emergency Medicine, Department of Surgery, Attending Physician, Medical Director, Department of Emergency Services, Yale-New Haven Hospital, Conn
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ANSWER
Urolithiasis with rupture of the right renal fornix: CT scans of the abdomen and pelvis demonstrate mild hydronephrosis in the right kidney, with evidence of perinephric fluid around the lower pole (arrow, Image 4). The fluid extends inferiorly along the retroperitoneum. The right ureter appears decompressed compared with the fluid-filled left ureter (arrow, Image 5). An area of mild hyperattenuation at the level of the right ureterovesical junction is likely to be a ureteral stone (arrow, Image 6). The CT findings suggest rupture of the right renal fornix.
Passage of a urinary stone is the most common cause of acute ureteral obstruction, affecting approximately 7% of men and 3% of women in the United States.7 The risk factors for the passage of urinary stones include male gender, gout, hyperparathyroidism, homocystinuria, patients undergoing chemotherapy, a sedentary lifestyle, and a family history of urolithiasis.
Pain caused by the passage of a ureteral stone is typically rapid in onset, colicky, severe, and sharp. It is located in the flank and often radiates to the testicles in men and the labia majora in women. Some patients have associated nausea with or without vomiting, and approximately one third of patients have gross hematuria. Most patients with urolithiasis are markedly uncomfortable, often pacing or writhing in bed. Anterior abdominal tenderness is usually absent or mild. Microscopic or gross hematuria is commonly found on urinalysis, but it may be absent in as many as 10% of patients.
Nonenhanced CT is the imaging modality of choice for evaluating urolithiasis because of its relatively high sensitivity and specificity for ureteral calculi and associated ureteral obstructions. In addition, CT is more sensitive than plain radiography and ultrasonography for localizing the exact position and size of calculi in the genitourinary tract and for ruling out potentially life-threatening conditions with similar presentations, such as abdominal aortic aneurysms, intra-abdominal infections, or renal abscesses. A point to stress is that patients undergoing CT evaluation for flank pain with suspicion of urolithiasis should have a non-contrast CT scan initially to avoid obscuring the stone with the radiopaque contrast and to avoid any risk of potential contrast-induced nephropathy or anaphylactoid reactions in at-risk patients.
Approximately 90% of calculi are radiopaque on plain radiographs, whereas those that are induced by indinavir or consist of pure uric acid or cystine are radiolucent. Moreover, plain radiography is <70% specific for urolithiasis because the findings may be confused with those of phleboliths or calcified mesenteric lymph nodes. The KUB has a role in following a patient with a radiopaque stone undergoing a trial of spontaneous passage. An abdominal and transvaginal ultrasound, though not ideal, may have a role in the pregnant woman so as to avoid radiation exposure to the fetus.
The first and foremost treatment for suspected urolithiasis is pain management. Adequate relief is usually achieved with a nonsteroidal anti-inflammatory drug (NSAID), such as ibuprofen or ketorolac; morphine sulfate and other narcotic agents can also be used if necessary. Antiemetics, such as metoclopramide and prochlorperazine, may also be administered as needed.
Consultation with urologists and/or admission to the hospital should be considered for patients with intractable pain, intractable nausea or vomiting, evidence of an associated urinary tract infection (especially if febrile), underlying chronic renal disease, acute renal failure, bilateral obstructing stones, or stones in a kidney transplant system or in a solitary kidney. A large stone (>8 mm in diameter) is not necessarily an indication for an urgent urologic consultation. A clinical caveat is that the size of the stone does not necessarily correlate with the degree of pain; however, the size of a stone does directly correlate with the chance of spontaneous passage. In other words, large stones are less likely to pass on their own and typically require urologic intervention; stones that are 4-6 mm pass in approximately 50% of patients, whereas stones larger than 8 mm pass in only approximately 20% of patients.8
Urinary extravasation not related to trauma is an uncommon urologic condition that results from rupture of the ureter or the calyceal fornix of the kidney. It is found in up to 1% of urograms, and about 50% of cases are attributed to a ureteral calculus. Urinary extravasation after a sudden ureteral obstruction can be explained on the basis of biophysical and urodynamic principles in which rupture of the elastic renal collecting system protects against increased intrapelvic pressure. Other etiologies of urinary extravasation include postrenal obstruction caused by prostate enlargement, pregnancy, abdominal aortic aneurysm, tumor, and iatrogenic causes (including IV pyelography and ureteral instrumentation). Traumatic renal forniceal rupture may occur in rapid-deceleration injuries because the renal fornix is a particularly vulnerable structure.
The clinical manifestations of urinary extravasation ranges from mild flank discomfort to unremitting abdominal pain. The condition may also be associated with nausea, vomiting, fever, and hematuria. Forniceal rupture can be difficult to clinically recognize because the symptoms of urinary extravasation closely resemble those of urolithiasis. The criterion standard for diagnosing urinary extravasation is IV urography; however, the ready availability of CT, combined with its high sensitivity and specificity, make it a feasible alternative in the clinical setting. Likewise, ultrasonography is easily performed and can depict small fluid collections in the perinephric area.
Urinary extravasation as a result of urolithiasis or other compressive pathologies often has a benign clinical course and spontaneously resolves, if the ureteral obstruction is rapidly relieved and the extravasated urine is sterile. Persistence of urine outside the kidney can result in complications, such as the formation of a urinoma (an encapsulated perirenal collection of urine), a perinephric infection, and progressive renal failure; therefore, patients should be referred to a urologist for close follow-up, and prophylactic antibiotics should be administered. Placement of an internal ureteral stent is usually sufficient to treat persistent extravasation. Traumatic renal forniceal rupture with urinary extravasation can usually be managed nonsurgically unless there is evidence of a clinically significant renal parenchymal laceration.
In this case, a urologist was consulted. The patient was taken to the operating room for a cystourethroscopy with right-sided retrograde pyelography. The pyelogram demonstrated residual hydronephrosis with extravasation of contrast material at the right ureteropelvic junction. A 2-mm stone fragment was retrieved from the urinary bladder. On follow-up 5 days later, the patient was doing well; an ultrasonogram demonstrated no residual perirenal fluid. A final point to make is that it is not common to perform ureteroscopy or retrograde pyelograms for a forniceal rupture. In most instances, even with a forniceal rupture with small stones, a trial of spontaneous passage is reasonable unless there are other contraindications.
References
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4. Akpinar H, Kural AR, Tufek I, et al. Spontaneous ureteral rupture: is immediate surgical intervention always necessary? Presentation of four cases and review of the literature. J Endourol. 2002;16(3):179-83. [MEDLINE: 12028629]
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6. Stein JH. Internal Medicine. 5th ed. St Louis, Mo: Mosby; 1998.
7. Walsh PC. Campbell’s Urology. 8th ed. Philadelphia, Pa: Saunders; 2002.
8. Smith JK, Lockhart ME. Nephrolithiasis/Urolithiasis. eMedicine Journal [serial online]. 2007. Available at: http://www.emedicine.com/radio/topic734.htm.
