I was translating a technical text and came across the following part in bold format. I have two questions regarding this:
Randomized trials have demonstrated that early ERCP (within 24 or 48 hours of admission) reduces complications, but not mortality, in patients with predicted severe gallstone-associated acute pancreatitis. The benefits of this invasive modality (release of the presumed impacted stone) may be offset, however, but the risks of the procedure, which include an increase in the severity of pancreatitis.
Q1: Is offset here a verb or noun? Does it mean "to neutralize some potential benefits"?
Q2: How should I get "however, but the risks of the procedure". It doesn't make any sense to me. I haven't seen any sentences like this before.