Steinstrasse is an iatrogenic condition resulting from upper urinary tract lithotripsy. Uncomplicated steinstrasse can be managed expectantly. Complex steinstrasse can pose a therapeutic challenge. The vacuum-assisted ureteral access sheath (vaUAS) is similar to a conventional ureteral access sheath but has a side branch that can be connected to vacuum apparatus. This device seemed to be useful in the management of complex steinstrasse. 35 patients with complex steinstrasse, defined as steinstrasse containing ≥ 4 stones or with an aggregate length of ≥ 1.5 cm, were treated in four tertiary medical centers using the vaUAS in this prospective and non-randomized study. The vaUAS was inserted into the ureter over a guidewire until the tip of the vaUAS was in contact with the lowermost stone fragment. A 7 Fr./8.4 Fr. semirigid ureteroscope and a holmium laser were used to pulverize the obstructing stone. All the stone fragments were aspirated either in the space between the scope and the sheath, or through the channel of the sheath by withdrawing the scope to the proximal of the aspiration port. All patients were steinstrasse-free at end of the procedure, as assessed visually and by KUB. At the 3-month follow-up, 94.3% of patients were stone-free with or without a supplementary procedure. There were no perioperative complications. Five patients experienced postoperative fever and/or significant hematuria, and one patient had transient sepsis, a grade I and IV Clavien complication, respectively. vaUAS can be an effective adjunctive device in the management of complex steinstrasse.© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.