Approximately 10% of Caucasian men will expect to suffer from renal stone disease by the age of 70 years. It is a growing problem in the UK, with a cross-sectional prevalence of approximately 1.2%. These statistics mean there are approximately 720,000 individuals with a history of kidney stones in the UK. 1 The increased prevalence of kidney stones parallels the well-publicised increase in the nation's prevalence of obesity and its well-documented relationship to urolithiasis.
2In 1912, the first visualisation of the upper urinary tract was performed by Hampton Young. He achieved this by passing a cystoscope into a mega-ureter of a paediatric patient. Subsequent developments in optics have revolutionised endourology and established the ureteroscopic treatment of ureteric and renal calculi.Although a comparison between extracorporeal shockwave lithotripsy (ESWL) and ureterorenoscopy (URS) removal of stones from the lower calyx of the kidney has failed to show a significantly better result with URS, 3 the updated 2007 American Urological Association/European Association of Urology (AUA/EAU) guidelines, and recent Cochrane meta-analysis, suggest that stone-free rates are superior with URS for all stone sizes and for all positions in the ureter, apart from stones in the upper third less than 10 mm in size. 4 Standard access to the ureter for endoscopic management of stone disease may be difficult due to anatomic abnormalities, a narrow ureteric lumen, tortuous ureteric path or previous instrumentation (Fig. 1). Failure of access will usually lead to the placement of a ureteric stent. The alternative for these difficult, tight ureters is extensive balloon dilatation, with the risk of trauma and the potential for long-term stricture formation. Difficulty may be encountered with retrograde access for rigid and flexible ureterorenoscopy (URS) due to anatomic abnormalities, a narrow ureteric lumen, tortuous ureteric path or previous instrumentation. Ureteric dilatation using a balloon or tapered dilator can occasionally fail and will usually lead to the placement of a ureteric stent. We present our experience and incidence of pre-stenting after failed standard access and dilatation techniques, the aim being to quote a figure for the patient at the time of consent. PATIENTS AND METHODS Data were collected prospectively from a single surgeon at a regional tertiary referral stone unit. The outcomes of those patients pre-stented, for failed access, were recorded. RESULTS Between December 2007 and December 2008, a total of 119 patients underwent flexible and rigid URS. Mean patient age was 49 years (range, 19-86 years). Of these, 107 cases were undertaken for urolithiasis and 12 cases for diagnosis of upper tract malignancy. 12% (13/107) of cases were for pain and non-diagnostic imaging and 8.4% (9/107) of patients were pre-stented because of failed access, without complication, and subsequently had successful interval treatment. Of the remaining successful cases of confirmed urolithiasis, 33% (28/85) and 67% (56/85) were und...