Dauw CA. et al., 2019: Shockwave Lithotripsy Use in the State of Michigan: American Urological Association Guideline Adherence and Clinical Implications
Dauw CA, Swarna K, Qi J, Kim T, Leavitt D, Leese J, Abdelhady M, Witzke K, Hollingsworth JM, Ghani KR.
University of Michigan, Ann Arbor, MI.
University of Michigan, Ann Arbor, MI.
Henry Ford Health System-Vattikuti Urology Institute, Detroit, MI.
IHA-Urology, Ypsilanti, MI.
Detroit Medical Center-Department of Urology, Detroit, MI.
MidMichigan-Division of Urology, Midland, MI.
Abstract
OBJECTIVE:
To understand how treatment of patients with urinary stones by shockwave lithotripsy (SWL) aligns with current published practice guidelines.
METHODS:
We used the Michigan Urologic Surgery Improvement Collaborative Reducing Operative Complications for Kidney Stones registry to understand SWL use in the state of Michigan. This prospectively maintained clinical registry includes data from community and academic urology practices and contains clinical and operative data for patients undergoing SWL and ureteroscopy (URS). We identified patients undergoing SWL from 2016 to 2019. In accordance with AUA guidelines, we evaluated practice patterns in relation to recommendations for treatment selection for SWL as well as clinical implications of guideline nonadherence.
RESULTS:
Four thousand, two hundred and nine SWL procedures performed across 34 practices were analyzed. Perioperative antibiotics were administered to 61.3% of patients undergoing SWL. A ureteral stent was placed at the time of SWL in 2.7% of patients. For lower pole renal stones >1 cm or large (>2 cm) renal stones in the registry, 32.2% and 58.9% of patients, respectively, underwent SWL, while the remainder were treated with URS. In these instances, SWL was associated with inferior stone-free rate (SFR) relative to URS. In patients with residual stones after SWL, 34.6% were treated with repeat SWL with lower SFR than those treated with subsequent URS. Postoperatively, 42.1% of patients were prescribed alpha-blockers with no benefit seen in terms of SFR.
CONCLUSION:
Substantial variation exists among urology practices with regard to SWL use. These data serve to inform quality improvement efforts regarding appropriateness criteria for SWL in Michigan.
Urology. 2019 Dec 13. pii: S0090-4295(19)31099-4. doi: 10.1016/j.urology.2019.11.037. [Epub ahead of print]
Comments 1
The authors evaluated adherence to the following guideline recommendations:
1 Guideline: “Routine antibiotic prophylaxis is not required prior to SWL unless there are risk factors”
Study Result: “Antibiotics were prescribed in 61.3% of patients undergoing SWL”
Comment: Not good
2 Guideline: “Routine stenting should not be performed in patients undergoing SWL.”
Study Result: “A ureteral stent was placed at the time of SWL in 2.7%”
Comment: Good
3 Guideline: “Clinicians should not offer SWL as first-line therapy to patients with >10mm lower pole stones.”
Study Result: “32.2% of patients, underwent SWL”
Comment: Not good
4 Guideline: “In patients with total renal stone burden >20mm, clinicians should not offer SWL as first-line therapy.”
Study Result: “58.9% of patients underwent SWL”
Comment: Not good
5 Guideline: “If initial SWL fails, clinicians should offer endoscopic therapy as the next treatment option”
Study Result: “34.6% were treated with repeat SWL”
Comment: Not good
6 Guideline: “Clinicians may prescribe a-blockers to facilitate passage of stone fragments following SWL.”
Study Result: “alpha-blockers were prescribed in 42.1% of patients following SWL. The SFR in those prescribed alpha-blockers did not differ significantly from those not prescribed therapy”
Comment: May be not important.
Comments in summary: Good: 1, Not good: 4, equivocal: 1. The authors discuss several reasons for the low adherence rate to the guidelines and do not know a proper explanation.
I was surprised to read that the postoperative imaging rate was 78.2% in the SWL group versus 43.0% in the URS group. The authors comment this finding by “this very likely leads to overestimation of SFR.” and a call to increase the number for better quality control. Of course imaging may not be necessary if a stone is removed intact: Otherwise I thought of Margaret Pearl’s comment on the quality of URS: “Is Ureteroscopy as Good as We Think?” (1) which essentially was: No!
1. Pearle MS. Is Ureteroscopy as Good as We Think? J Urol. 2016 Apr;195 :823-4. doi: 10.1016/j.juro.2016.01.061