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Three Part Question

[in adults presenting to A&E with loin pain] [does clinically diagnosed renal colic] [rule out the diagnosis of non-obstructing renal stones]

Clinical Scenario

A 39 year old man presents to A&E with a loin pain that is diagnosed as renal colic on clinical grounds. In particular the consultant suspects an obstructive uropathy. However, you wonder if non-obstructing renal stones can cause similar pain to obstructive uropathy.

Search Strategy

Ovid MEDLINE 1946 to June week 3 2012
Embase 1974 to 2012 July
Cochrane Database of Systematic Reviews 2005 to June 2012
Pubmed
[exp Renal Colic/] OR [Colic/] AND [exp Ureteral Obstruction/] AND [nonobstruct$.mp.] OR [non-obstruct$.mp.]

Search Outcome

8 papers found on Medline
6 papers found on EMBASE
4 papers found on Pubmed
2 relevant papers found plus 2 abstracts.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Coury T, Sonda L, Lingeman J et al. 1988 USA	Patients with painful nonmobile caliceal stones	Case series: 26 patients identified from case notes were then operated on to remove the caliceal stones.	Relief of pain	25 of 26 (96%) patients had complete pain relief	Small group size. Selection bias may be present. No controls.
Furlan A, Federle M, Yealy D et al. 2008 USA	Consecutive patients who presented to A&E with renal colic who had had an unenhanced CT	Retrospective case series.	Incidence of nonobstructing renal stones presenting to A&E with colic.	31 of 173 (18%) of patients presenting to A&E with colic were found to have nonobstructing renal stones.	Retrospective. Only gives incidence of findings, no proof of association between small stones and colic, in fact more people 51 (30%) presented with colic and no findings at all on CT – so stones could easily be incidental.
Andersson L, Sylvén M 1983	Patients with long standing loin pain with small caliceal calculi	Case series: 7 patients with painful caliceal calculi underwent removal by percutaneous puncture	Pain relief	7 of 7 (100%) of patients were relieved of pain	ABSTRACT Very small sample
Brannen G, Bush W, Lewis G 1986	Patients with nonobstructive caliceal calculi	Case series: 51 patients had nephrostolithotomy for caliceal calculi due to: pain in 36, infection in 11, stone growth in 2, haematuria in 1, flight status eligibility in 1.	Resolution of symptoms	34 of 36 (95%) of patients with pain reported complete resolution of pain.	ABSTRACT Small sample size. Case series.

Comment(s)

The cause of renal colic is widely accepted to be due to obstruction of the ureter by a stone; this causes a hydronephrosis and the stretching of the ureter and renal pelvis is interpreted as colic. Small stones which do not obstruct are therefore deemed as unlikely to cause colic. However some studies have theorised that these small stones can intermittently obstruct the flow of urine at the caliceal level, which would be not cause hydronephrosis and therefore be undetectable; another theory is that the stone is simply an irritant. It is reported that this pain can be slightly different to a typical colic attack; less severe and less likely to radiate to the groin. These studies found that there removal of such stones tended to improve symptoms, however only low level evidence is available.

Clinical Bottom Line

Non-obstructing renal stones may be able to present as renal colic and should not be ruled out on this basis.

References

1. Coury T, Sonda L, Lingeman J et al. Treatment of painful caliceal stones. Urology 1988; 32(2):119-23
2. Furlan A, Federle M, Yealy D et al. Nonobstructing stones on unenhanced CT: a real cause for renal colic? AJR Am J Roentgenol 2008; 190(2):W125-7
3. Andersson L and Sylvén M Small renal caliceal calculi as a cause of pain J Urol 1983; 130(4):752-3
4. Brannen G, Bush W, Lewis G. Caliceal Calculi. J Urol 1986; 135(6):1142-5