Urologists.co.uk

Postgrad Med J 2007;83:469–472. doi: 10.1136/pgmj.2006.055913 The diagnostic approach to ureteric colic has changed due to ultrasound, intravenous urography and computed the introduction of new radiological imaging such as non- contrast CT. The role of intravenous urography, which is Plain radiograph of the kidney, ureter and regarded as the gold standard for the diagnosis of ureteric colic, is being challenged by CT, which has become the first-line A plain radiograph of the kidney, ureter and bladder (KUB) has a sensitivity that ranges from investigation in a number of centres. The management of 45–60% in the evaluation of acute flank pain.2 ureteric colic has also changed. The role of medical treatment Overlaying bowel gas or stool (faecoliths) and has expanded beyond symptomatic control to attempt to target abdominal or pelvic calcifications (phleboliths) can make identification of ureteric stones difficult. In some of the factors in stone retention and thereby improve the addition, a KUB cannot visualise radiolucent likelihood of spontaneous stone expulsion.
stones (10–20% of stones), thus limiting the value of plain radiography. However, a KUB may sufficefor assessing the size, shape, and location ofurinary calculi in some patients (fig 1).
Ureteric colic is an important and frequent emergency in medical practice. It is most commonly caused by the obstruction of the Ultrasonography allows direct demonstration of urinary tract by calculi. Between 5–12% of the urinary stones located at the PUJ, the VUJ, and in population will have a urinary tract stone during the renal pelvis or calyces.3 Stones located between their lifetime, and recurrence rates approach 50%.1 the PUJ and VUJ, however, are extremely difficultto visualise with ultrasonography.
CLINICAL PRESENTATIONThe classic presentation of a ureteric colic is acute, Intravenous urography colicky flank pain radiating to the groin. The pain Since it was first performed in 1923, intravenous is often described as the worst pain the patient has urography (IVU) has been the traditional ‘‘gold ever had experienced. Ureteric colic occurs as a standard'' in the evaluation in ureteric colic. It result of obstruction of the urinary tract by calculi provides structural and functional information, at the narrowest anatomical areas of the ureter: including site, degree and nature of obstruction.
the pelviureteric junction (PUJ), near the pelvic Whereas IVU has a detection rate as high as 70– brim at the crossing of the iliac vessels and the 90% (fig 2),4 it can only visualise radiopaque narrowest area, the vesicoureteric junction (VUJ).
stones (80–90% of stones). Despite its usefulness, Location of pain may be related but is not an there are some undesirable aspects of IVU, includ- accurate prediction of the position of the stone ing radiation exposure, risk of nephrotoxicity, within the urinary tract. As the stone approaches contrast reaction and the time it takes, particularly the vesicoureteric junction, symptoms of bladder when delayed films are required.
irritability may occur.
Calcium stones (calcium oxalate, calcium phos- The reported incidence of contrast-induced renal phate and mixed calcium oxalate and phosphate) failure is approximately 1%,5 while in the popula- are the most common type of stone, while up to tion with pre-existing renal failure and diabetes 20% of cases present with uric acid, cystine and mellitus, the risk of contrast-induced nephrotoxi- struvite stones.
Physical examination typically shows a patient Metformin is an oral agent, used in the manage- who is often writhing in distress and pacing about ment of diabetes mellitus. Metformin is excreted trying to find a comfortable position; this is, in unmetabolised by the kidney. It is not nephrotoxic; contrast to a patient with peritoneal irritation who See end of article for however, a major concern is the potential hazard authors' affiliations of metformin-induced lactic acidosis in those who Tenderness of the costovertebral angle or lower develop contrast-induced oliguria. In this setting, quadrant may be present. Gross or microscopic Correspondence to: metformin can accumulate, resulting in the sub- haematuria occurs in approximately 90% of Dr M Masarani, 18 St sequent accumulation of lactic acid. Metformin- Peter's Way, London W5 patients; however, the absence of haematuria does induced lactic acidosis is fatal in half of the 2QR, UK; mmasaarane@ not preclude the presence of stones.
Abbreviations: CT, computed tomography; IVU, intravenous urography; KUB, plain radiograph of the Besides routine history and clinical examination, kidney, ureter and bladder; MET, medical expulsive Accepted 25 January 2007 investigations of patients with suspected ureteric therapy; NSAIDs, non-steroidal anti-inflammatory drugs; PUJ, pelviureteric junction; VUJ, vesicoureteric junction

Masarani, Dinneen Figure 1 Patient presented with left loin pain. Kidney, ureter and bladder Figure 2 Patient after administration of intravenous contrast medium, (KUB) x ray showing 7 mm radiopaque stone laying lateral to the tip of showing left nephrogram and contrast coming down to the level of the transverse process of L2.
affected patients; however, it is a very rare complication.7 incidence of extra-urinary abnormality with CT is 6–12%.11 In patients with normal renal function metformin should be Those reported abnormalities include pelvic inflammatory discontinued at the time of the IVU and withheld for the disease, adnexal masses, tubo-ovarian abscess, appendicitis, subsequent 48 h. For patients with abnormal renal function, diverticulitis, cholecystitis, pancreatitis or unexpected malig- metformin should similarly be discontinued at the time of the nancy. In some cases, intravenous contrast medium will be IVU and only be reinstated when renal function has been re- necessary for further characterisation of any of the unexpected evaluated and found to be normal.8 Contrast reaction Disadvantages of CT In the general population the incidence of contrast reaction is An important limitation of CT is the fact that it does not permit 5–10%, including mild reactions such as vomiting and urticaria, functional evaluation of the kidneys and it is unable to assess as well as more serious reactions such as bronchospasm and the degree of obstruction. The presence of a stone does not anaphylaxis (the risk of anaphylaxis is 157 per 100 000).9 The necessarily mean that the kidney is obstructed. The relative lack incidence of contrast reaction can be diminished in many cases of functional information derived from CT, compared with the with the use of expensive low osmolar contrast agents but it renal excretory times evident during IVU, might compromise cannot be entirely eliminated.
clinical management. However, some authors have suggestedthat secondary features of obstruction on CT which include Non-contrast enhanced computed tomography hydronephrosis, hydroureter, renal enlargement and inflam- Unenhanced computed tomography (CT) provides an increas- matory changes of the perirenal fat, that are referred to as ingly popular alternative for evaluating ureteric colic.
perinephric stranding, are a reliable parallel of delayedexcretion on IVU.12 Another major disadvantage of CT is the higher radiation CT has the following advantages over IVU: it has higher exposure of the patient compared with KUB or IVU. CT in this sensitivity and specificity for calculus detection, it does not use setting requires at least three times the radiation exposure of intravenous contrast medium, it permits alternative diagnoses, IVU and 10 times that of abdominal radiography and presents and requires a shorter examination time.
an additional lifetime risk of malignancy of 1 in 4000.13 Newer The accuracy of non-contrast CT in detecting stone disease protocols involving reduced radiation exposure without com- has been indisputable with sensitivity, specificity and positive promising efficacy are developing and are likely to reduce predictive value of CT being reported as 96%, 100% and 100%, further the radiation exposure from CT (table 1). Low-dose and respectively.10 CT can visualise all radiopaque stones, as well as ultra low-dose CT reduced radiation exposure by about 50% and radiolucent stones such as uric acid and cystine calculi (fig 3).
95%, respectively, compared with standard-dose CT, with When CT confirms the presence of a stone, a plain abdominal comparable detection rates of calculi and non-stone-associated radiograph should be obtained to assess whether the stone is abnormalities (table 2).14 15 radiopaque. This is helpful as only the KUB radiograph is Another disadvantage is that CT services are not universally needed later to determine if the stone has moved or passed.
available for 24 h period and a radiologist may be required for Avoiding the use of intravenous contrast medium is perhaps the accurate interpretation of the films.
the most distinct benefit of CT in this situation.
Finally, in the current healthcare climate, cost and avail- CT also provides an opportunity to identify extra-urinary ability will always be central factors determining the use of CT pathology during the primary investigation of patients in whom in the acute setting. A frequent criticism of CT is that it costs a definitive diagnosis is not always apparent. The reported more than IVU. However, when taking into account the

Table 1 Radiation exposure of different imagingmodalities Radiation exposure (mSv) Ultra-low dose CT CT, computed tomography; IVU, intravenous urography; KUB,plain radiograph of the kidney, ureter and bladder.
these drugs to be as effective as opioids, with the latter used asrescue medications.18 Opioids have higher rates of nausea,vomiting, and dizziness.
Data on the effect of opiates on ureteric tone suggest that they cause an increase or no change in tone. Opiate-seekingpatients might therefore spuriously present with symptoms ofureteric colic.
NSAIDs block prostaglandin-induced effects. They also reduce local oedema and inflammation, and inhibit thestimulation of ureteric smooth muscle, which is responsiblefor increased peristalsis and subsequently increased uretericpressure. Although NSAIDs reduce pain associated withureteric colic, they may potentially interfere with the kidney'sautoregulatory response to obstruction by reducing renal bloodflow, and renal failure may be induced with pre-existing renaldisease. The choice of agent is generally based on clinicianpreference, personal experience and institutional culture.
Medical expulsive therapyThe traditional treatment indicated above has recently beenimproved by the application of active medical expulsive therapy(MET). Protocols were developed based on the possible causes Figure 3 Non-contrast computed tomography (CT) showing right vesicoureteric junction (VUJ).
of failure to pass a stone spontaneously, including muscle advantage of reduced expenditure in terms of time and Table 2 Intravenous urography (IVU) versus computed manpower for CT, it is suggested that indirect costs are much lower for CT scans.16 Indisputable accuracy Given that most ureteric stones will pass spontaneously,conservative treatment in the form of observation with Risk of nephrotoxicity or No intravenous contrast is dangerous reaction to necessary so no risk of analgesia is the preferred approach. Ureteric stones require intravenous contrast medium nephrotoxicity or contrast radiological or surgical intervention only when the conservative treatment fails. The probability of spontaneous passage is basedon a number of factors including stone size, stone position, Cannot be used in azotemia or known significant allergy to degree of impaction and degree of obstruction. The likelihood of intravenous contrast agents spontaneous stone passage decreases as the size of the stoneincreases (table 3).17 Most authors recommend that stone Less radiation dose Standard CT requires at passage should not exceed 4–6 weeks due to the risk of renal least three times the radiation exposure of IVU Hard to see radiolucent stones, With only rare exceptions although indirect signs of it shows all stones clearly The pain of ureteric colic is due to obstruction of urinary flow, obstruction may be apparent with a subsequent increase in wall tension. Rising pressure inthe renal pelvis stimulates the local synthesis and release of Shows relative kidney function Does not give functional prostaglandins, and subsequent vasodilatation induces a diur-esis which further increases intrarenal pressure. Prostaglandins Ureteric kinks, strictures or also act directly on the ureter to induce spasm of the smooth tortuosities are often visible muscle. Owing to the shared splanchnic innervation of the Cannot be used to evaluate Demonstrates other renal capsule and intestines, hydronephrosis and distension of the renal capsule may produce nausea and vomiting.
Relatively slow, may need multiple delay films, which The choice of analgesia used in the management of acute ureteric colic is changing, with increasing use of non-steroidalanti-inflammatory drugs (NSAIDs). Most studies have shown Masarani, Dinneen . . . . . . . . . . . .
Authors' affiliations Table 3 Likelihood of passage of ureteric stones17 M Masarani, M Dinneen, Department of Urology, Imperial College London, Chelsea & Westminster Teaching Hospital, London, UK spontaneous passage (%) Conflict of interest: none stated 1 Sierakowski R, Finlayson B, landes RR, et al. The frequency of urolithiasis in hospital discharge diagnoses in the United States. Invest Urol 1978;15:438–41.
2 Mutgi A, Williams JW, Nettleman M. Renal colic: utility of the plain abdominal roentgenogram. Arch Intern Med 1991;151:1589–92.
3 Sheafor DH, Hertzberg BS, Freed KS, et al. Non-enhanced helical CT and US in spasm, local oedema, inflammation, and infection. Regimens the emergency evaluation of patients with renal colic: prospective comparison.
have commonly included a corticosteroid (to reduce local oedema through its anti-inflammatory action), antibiotics (to 4 Miller OF, Rineer SK, Reichard SR, et al. Prospective comparison of unenhanced spiral computed tomography and intravenous urogram in the evaluation of acute prevent or treat urinary tract infection), as well as calcium flank pain. Urology 1998;52:982–7.
antagonists and a-blockers (agents directed towards stone- 5 Levy EM, Viscolli CM, Horwitz RI. The effect of acute renal failure on mortality: A induced ureteric spasm). Combination therapy is intended for cohort analysis. JAMA 1996;275:1489–94.
6 Barrett BJ, Carlisle EJ. Meta analysis of the relative nephrotoxicity of high- and short-term use.
low-osmolality iodinated contrast media. Radiology 1993;188:171–5.
7 Thompson NW, Thompson TJ, Love MHS, et al. Drugs and intravenous media.
NSAID: NSAIDs have ureteric-relaxing effects and, as such, BJU Int 2000;85:219–21.
can be considered to be a form of MET; yet the only 8 Royal College of Radiologists. Royal College of Radiologists' guidelines with randomised, double blinded, placebo-controlled trial showed regard to metformin-induced lactic acidosis and x-ray contrast medium agents.
London: The Royal College of Radiologists, 1999;99:2.
no difference in augmenting stones passage between 9 Shehadi WM, Toniolo G. Adverse reactions to contrast media: a report from the NSAIDs and placebo.19 Committee on Safety of Contrast Media of the International Society of Radiology.
N Calcium antagonists: Ureteric smooth muscle uses an 10 Worster A, Preyra I, Weaver B, et al. The accuracy of noncontrast helical active calcium channel pump in order to contract. Calcium computed tomography versus intravenous pyelography in the diagnosis of antagonists suppress the fast component of ureteric con- suspected acute urolithiasis: a meta-analysis. Ann Emerg Med 2002;40:280–6.
traction, leaving peristaltic rhythm unchanged. Therefore 11 Ahmad NA, Ather MH, Rees J. incidental diagnosis of disease on un-enhanced helical computed tomography performed for ureteric colic. BMC Urol calcium channel blockers, which are commonly used in the treatment of hypertension and angina, have been used to 12 Smith RC, Verga M, Dalrymple N, et al. Acute ureteral obstruction: value of relax ureteric smooth muscle and enhance stone passage.20 secondary signs of obstruction of the urinary tract on unenhanced helical CT.
Am J Roentgenol 1996;167:1109–13.
a-Blockers: a1-Adrenergic antagonists are currently com- 13 Denton ER, Mackenzie A, Greenwell T, et al. Unenhanced helical CT for renal monly used as first-line treatment in men with lower urinary colic: is the radiation dose justifiable? Clin Radiol 1999;54:444–7.
tract symptoms. Both a and b adrenoreceptors have been 14 Meagher T, Sukumar VP, Collingwood J, et al. Low-dose computed tomography shown to exist within the ureter, particularly in the lower in suspected acute renal colic. Clin Radiol 2001;56:873–6.
15 Kluner C, Hein PA, Gralla MD, et al. Does ultra-low-dose CT with a radiation and intramural portions. a1-Adrenergic antagonists inhibit dose equivalent to that of KUB suffice to detect renal and ureteral calculi? Comput the basal tone, peristaltic wave frequency and the ureteric Assist Tomogr 2006;30:44–50.
contraction in the intramural parts. As a result the 16 Pfister SA, Deckart A, Laschke S, et al. Unenhanced helical computed tomography vs intravenous urography in patients with acute flank pain: accuracy intraureteric pressure below the stone decreases and and economic impact in a randomized prospective trial. Eur Radiogr elimination of the stone can be achieved.21 17 Miller OF, Kane CJ. Time to stone passage for observed ureteral calculi: a guide Patients treated with calcium antagonists or a-blockers had a to patient education. J Urol 1999;162:688–90.
65% greater likelihood of spontaneous stone passage than 18 Holdgate A, Pollock T. Nonsteroidal anti-inflammatory drugs versus opioids for acute renal colic. Cochrane Database Syst Rev 2004;(1):CD004137.
patients not given these drugs. Calcium-channel blockers and 19 Laerum E, Ommundsen OE, Gronseth JE, et al. oral diclofenac in the a-blockers seemed well tolerated.22–25 prophylactic treatment of recurrent renal colic. A double-blind comparison with The addition of corticosteroids might have a small advantage placebo. Eur Urol 1995;28:108–11.
but the benefit of drug therapy is not lost in those patients for 20 Salman S, Castilla C, Vela NR. Action of calcium antagonists on ureteral dynamics. Actas Urol Esp 1989;13:150–2.
whom corticosteroids might be contraindicated.26–28 21 Sigala S, Dellabella M, Milanese G, et al. Evidence for the presence of a 2 There are additional benefits which seem to be associated adrenoceptor subtypes in the human ureter. Neurourol Urodyn 2005;24:142–8.
with MET. Patients have a significantly reduced time to stone 22 Porpiglia F, Destefanis P, Fiori C, et al. Effectiveness of nifedipine and defluzacort in the management of distal ureteral stones. Urology 2000;56:579–83.
passage, significantly fewer pain episodes, lower analogue pain 23 Dellabella M, Milanese G, Muzzonigro G. Efficacy of tamsulosin in the medical scores, and need significantly lower doses of analgesics.
management of juxtavesical ureteral stones. J Urol 2003;170:2202–5.
When conservative therapy fails, the choice of treatment lies 24 Dellabella M, Milanses G, Muzzonigro G. Randomized trial of the efficacy of between shock wave lithotripsy and ureteroscopy. Surgical tamsulosin, nifedipine and phloroglucinol in medical expulsive therapy for distalureteral calculi. J Urol 2005;174:167–72.
management is beyond the scope of this article and it is not 25 Hollingsworth JM, Rogers MAM, Kaufman S, et al. medical therapy to facilitate discussed here.
urinary stones passage: a meta analysis. Lancet 2006;368:1171–9.
26 Dellabella M, Milanses G, Muzzonigro G. medical expulsive therapy for distal ureterolithiasis: Randomized prospective study on the role of corticosteroids usedin combination with tamsulosin-simplified treatment regimen and health-related Acute ureteric colic is a common surgical emergency. There is a quality of life. 2005;66:712–15.
shift towards using non-contrast CT in evaluating ureteric colic.
27 Salehi M, Fouladi MM, Shier H, et al. Does methylprednisolone acetate increase MET has shown promise in increasing the spontaneous stone the success rate of medical therapy for patients with distal ureteral stones. EurUrol Suppl 2005;4:24–8.
passage rate and relieving discomfort while minimising 28 Pearle MS. Comment on medical therapy to facilitate urinary stones passage.
narcotic usage.

Source: http://urologists.co.uk/wp-content/uploads/2016/04/Ureteric-colic.pdf