Background: The patient on antiplatelet therapy presenting for extracorporeal shock wave lithotripsy (ESWL) embodies one of the most clinically consequential dilemmas in lithotripsy practice: the tension between shock wave-induced renal parenchymal hemorrhage and the potentially catastrophic thrombotic risk of antiplatelet discontinuation — particularly in patients with drug-eluting coronary stents (DES), recent acute coronary syndrome (ACS), or cerebrovascular disease. Shock waves cause renal hemorrhage through cavitation-mediated capillary disruption; in patients with pharmacologically impaired platelet function, this injury spectrum extends from subclinical subcapsular hematoma — detectable on imaging in 11–25% of patients — to clinically significant hemorrhage requiring intervention. No randomized controlled trials exist comparing continued versus withheld antiplatelet therapy during ESWL, and the available observational literature is sparse, retrospective, and non-standardized.

Objectives: This article constructs an evidence-informed, risk-stratified clinical framework for ESWL management in patients on antiplatelet therapy. It addresses the biology of shock wave-induced renal hemorrhage and platelet function, the pharmacology and washout kinetics of each antiplatelet class encountered in practice, the cardiovascular risk of antiplatelet cessation, the pivotal Regensburg systematic review re-classifying low-dose aspirin monotherapy risk, and the paradox revealed by global endourologist practice survey data. A three-tier patient classification system based on cardiovascular indication — not merely drug identity — is presented alongside a practical intraoperative and post-procedure protocol.

Methods: A structured narrative review was conducted incorporating the Regensburg systematic Medline/PubMed review of antiplatelet and anticoagulant management during SWL (Netsch et al., J Endourol 2014; PMID: 24851726), the sentinel Ruiz and Saltzman bilateral renal hemorrhage case report (J Urol 1990; PMID: 2313074), the Saltzman hematoma incidence cohort data, the Endourology Society global practice survey of approximately 2,000 members (J Urol 2017), the 2016 ACC/AHA DAPT guideline update, the ASSURE-DES randomized controlled trial (JACC 2024), and established stent thrombosis risk data from the perioperative cardiology literature. Pharmacological washout parameters for aspirin, clopidogrel, ticagrelor, and prasugrel were synthesized alongside the cardiovascular consequence data for each agent’s interruption.

Results: The Regensburg systematic review concluded that low-dose aspirin monotherapy should not be treated as an absolute contraindication to ESWL — representing a significant evolution from historical practice. The Endourology Society survey revealed a striking practice inversion: 79% of endourologists perform ureteroscopy on aspirin, yet only 18% perform ESWL on aspirin (OR 9.2; p < 0.001), an asymmetry unsupported by comparative hemorrhage evidence. The cardiovascular cost of antiplatelet cessation is well-quantified: aspirin withdrawal carries an odds ratio of 3.1 for cardiac complications peaking at day 10 (the aspirin withdrawal syndrome), while clopidogrel cessation carries an odds ratio of 14–57 for stent thrombosis in the first 18 months after DES implantation; interrupting dual antiplatelet therapy (DAPT) within 6 weeks of coronary stenting carries a cardiovascular mortality of up to 71% — dwarfing any conceivable ESWL hemorrhage mortality. The ASSURE-DES RCT found no stent thrombosis in either continuation or cessation arm in patients beyond 1 year from DES implantation, and no significant difference in major bleeding. Critically, low molecular weight heparin is not a valid bridge for antiplatelet cessation — it does not prevent platelet-driven stent thrombosis and confers bleeding risk without antiplatelet benefit, a principle explicitly codified in ACC/AHA guidelines. A delayed perinephric hematoma case (ScienceDirect 2025) — presenting one week post-ESWL in an anticoagulated patient — underscores that hemorrhagic complications can be clinically occult and temporally remote from the procedure.

Conclusions: The governing clinical question is not whether to stop antiplatelet therapy for ESWL, but what the thrombotic consequence of stopping it is for the individual patient. A three-tier risk stratification based on cardiovascular indication — Tier 1 (low-dose aspirin monotherapy in stable cardiovascular disease), Tier 2 (DAPT beyond 12 months of DES), and Tier 3 (DAPT within 6 months of DES or 3 months of ACS) — determines the management pathway. Tier 1 patients can proceed with ESWL on aspirin with protocol modifications; Tier 2 patients require mandatory cardiology consultation and guideline-based P2Y12 cessation with aspirin continuation; Tier 3 patients should have elective ESWL deferred, with ureteroscopy on maintained DAPT preferred for urgent stone treatment. Protocol modifications for all antiplatelet patients include shock rate reduction to 60/min, mandatory energy ramping, a strict session limit of ≤ 2,000 shock waves, avoidance of NSAIDs perioperatively, and routine renal ultrasound at 48–72 hours post-procedure for Tier 2 and Tier 3 patients.