On the diagnosis and treatment of upper urinary tract stones

Abstract

Aims: Papers I&II: To compare treatment outcome for renal stones treated with different ESWL-machines and treatment results of ESWL and ureteroscopy (URS) for ureteric stones. Paper III: To investigate the morbidity and incidence of acute renal colic and the proportion of patients with absolute and relative indications for immediate radiological examination. Paper IV: To compare sensitivity for stone detection and renal outflow obstruction with non-enhanced helical CT (NCCT) versus urography in the diagnosis of acute renal colic.Patients and methods: Paper I: In a prospective cohort study in Sweden, 1171 patients treated for renal stones with ESWL with 7 different ESWL-machines at 11 centres were evaluated regarding treatment results. Paper II: In a retrospective study, an unselected patient material was reviewed. In 1998, 173 ureteric stones were treated, URS was first-line treatment in 124 patients. In 2000, 176 patients were treated, ESWL was first-line treatment in 158 patients. Paper III: In a prospective randomised study, 172 patients with renal colic who became pain-free after analgetics were included. They were randomised to immediate or deferred (within 2-3 weeks) radiological examination. All patients answered a questionnaire on a daily basis regarding morbidity, defined as impairment of daily activities, consumption of analgetics, need for emergency department revisits or hospitalisation. Treatments were registered Paper IV: Prospectively, 131 patients with acute renal colic were included. All patients underwent NCCT immediately followed by urography. Two independent, blinded radiologists assessed the NCCT findings regarding stone detection and renal outflow obstruction, in comparison with urography. Results: Paper I: Treatment outcome differed statistically between centres and between centres with the same type of EWSL-machines. Larger and multiple stones as well as location in a cavity increased the risk for treatment failure. Paper II: Treatment success with ESWL was 90% compared with 95% for URS, no statistical difference was noted. Paper III: The incidence of acute renal colic was 0.9/1000 inhabitants and year, 74% became pain-free after analgetics. There was no statistical difference regarding morbidity or treatment incidence between the two groups. Impairment of daily activities lasted a median of two days in both groups. Paper IV: In patients with absolute indication for immediate radiological examination, NCCT detected all stones, urography missed two stones of 22. Corresponding figures for patients with relative indication were 49 out of 52, urography missed 15 stones. In each group, NCCT detected all but one patient with moderate or severe renal outflow obstruction. Conclusion: Paper I: Treatment outcome after ESWL was dependent on the machine used, stone status and treatment policy at each center. Paper II: Treatment results were equally good for ESWL and URS. Paper III: In patients with renal colic, 74% had relative indications for immediate radiological examination. The morbidity following renal colic was low and was not altered by performing the radiological examination within 24 hours, as compared with 2-3 weeks. Paper IV: For stone detection in the upper urinary tract, NCCT appears more accurate than urography. NCCT can identify clinically important renal outflow obstruction with a high degree of certainty.