Matched Pair Analysis of Ureteroscopy vs. Shock Wave Lithotripsy
Matched Pair Analysis of Ureteroscopy vs. Shock Wave Lithotripsy
There is controversy over whether shock wave lithotripsy (SWL) or ureteroscopy (URS) is the best management of ureteric calculi, especially for stones located in the upper ureter. This study compares URS and SWL management of upper ureteric stones directly for the first time using a different analysis tool, the matched pair analysis study design. This method enables meaningful comparisons to be made on a small number of matched patients, using precise like-for-like matching. Adult patients undergoing primary treatment of solitary radiopaque proximal ureteric stones were identified. Patients with stents, nephrostomies or stones at the pelvi-ureteric junction were excluded. Patients had a minimum of 3 months follow-up. Patients treated by primary URS were matched using four parameters (sex, laterality, stone size and location) to patients treated on a Dornier Compact Delta Lithotriptor. A total of 1479 patients had URS or SWL from which 27 upper ureteric stone matched pairs were identified. Three-month stone free rates were 82% for URS and 89% for SWL (McNemar's test, p = 0.625). Re-treatment was required in 11% and 26% following URS and SWL respectively (p = 0.219). Forty-one per cent of URS patients required an ancillary treatment, such as stent removal, compared with only 22% of SWL patients (p = 0.227). Introduction of a holmium:YAG laser for use with URS improved the stone free rate for URS to 100%. Using a robust like-for-like comparison of similar patients with very similar upper ureteric stones the outcomes following SWL and URS were comparable. Choice of treatment should therefore be based on parameters such as availability of equipment, waiting times and patient preference.
Both extracorporeal shock wave lithotripsy (SWL) and ureteroscopy (URS) are well-established forms of management for ureteric calculi. SWL is the most popular form of management for upper ureteric stones, because of its low morbidity, non-invasiveness and acceptable efficacy . Modern ureteroscopes and intracorporeal lithotripsy also share good safety profiles but are more often utilised for distal ureteric stones and lithotripsy failures. Developments in ureteroscope and laser design has resulted in easier access to the entire ureter and greatly decreased complication rate making URS management of proximal ureteric stones much more attainable .
There have not been any previous prospective randomized trials of URS vs. SWL for proximal ureteric stones. The available comparative series show superior efficacy for URS over SWL in the management of upper ureteric calculi . However, such studies are hampered by discrepancies in cohort size, selection bias and inadequate follow-up. Matched pair analysis enables comparison of two treatment modalities with a relatively small clinical study group, by comparing ‘like-for-like' stones . Calculi of equivalent size, side and position in similar patients are matched and the results of different treatments compared. The aim of this study was to compare the efficacy of SWL with URS treatment of upper ureteric stones using a matched pair analysis study design.
Summary and Introduction
Summary
There is controversy over whether shock wave lithotripsy (SWL) or ureteroscopy (URS) is the best management of ureteric calculi, especially for stones located in the upper ureter. This study compares URS and SWL management of upper ureteric stones directly for the first time using a different analysis tool, the matched pair analysis study design. This method enables meaningful comparisons to be made on a small number of matched patients, using precise like-for-like matching. Adult patients undergoing primary treatment of solitary radiopaque proximal ureteric stones were identified. Patients with stents, nephrostomies or stones at the pelvi-ureteric junction were excluded. Patients had a minimum of 3 months follow-up. Patients treated by primary URS were matched using four parameters (sex, laterality, stone size and location) to patients treated on a Dornier Compact Delta Lithotriptor. A total of 1479 patients had URS or SWL from which 27 upper ureteric stone matched pairs were identified. Three-month stone free rates were 82% for URS and 89% for SWL (McNemar's test, p = 0.625). Re-treatment was required in 11% and 26% following URS and SWL respectively (p = 0.219). Forty-one per cent of URS patients required an ancillary treatment, such as stent removal, compared with only 22% of SWL patients (p = 0.227). Introduction of a holmium:YAG laser for use with URS improved the stone free rate for URS to 100%. Using a robust like-for-like comparison of similar patients with very similar upper ureteric stones the outcomes following SWL and URS were comparable. Choice of treatment should therefore be based on parameters such as availability of equipment, waiting times and patient preference.
Introduction
Both extracorporeal shock wave lithotripsy (SWL) and ureteroscopy (URS) are well-established forms of management for ureteric calculi. SWL is the most popular form of management for upper ureteric stones, because of its low morbidity, non-invasiveness and acceptable efficacy . Modern ureteroscopes and intracorporeal lithotripsy also share good safety profiles but are more often utilised for distal ureteric stones and lithotripsy failures. Developments in ureteroscope and laser design has resulted in easier access to the entire ureter and greatly decreased complication rate making URS management of proximal ureteric stones much more attainable .
There have not been any previous prospective randomized trials of URS vs. SWL for proximal ureteric stones. The available comparative series show superior efficacy for URS over SWL in the management of upper ureteric calculi . However, such studies are hampered by discrepancies in cohort size, selection bias and inadequate follow-up. Matched pair analysis enables comparison of two treatment modalities with a relatively small clinical study group, by comparing ‘like-for-like' stones . Calculi of equivalent size, side and position in similar patients are matched and the results of different treatments compared. The aim of this study was to compare the efficacy of SWL with URS treatment of upper ureteric stones using a matched pair analysis study design.
