Overview Interscalene Block Versus Superior Trunk Block Status: Completed Trial end date: 2019-07-09 Target enrollment: Participant gender: Summary Sparing the phrenic nerve by administering ultrasound-guided low volume superior trunk block (STB) and interscalene block (ISB) for arthroscopic shoulder surgery (labral repair, stabilization, rotator cuff repair). Phase: Phase 4 Details Lead Sponsor: Hospital for Special Surgery, New YorkTreatments: Bupivacaine