Pyatt agreed to terms on a one-year contract with Swedish side Skelleftea AIK on Friday.
The Canucks traded Pyatt and a 2019 sixth-round pick for Francis Perron and a 2019 seventh-round pick Saturday.
Pyatt was brought in to Vancouver from Ottawa along with Mike McKenna and a 2019 sixth-round pick in exchange for Anders Nilsson and Darren Archibald.
Pyatt was waived by the Senators on Tuesday, Elliotte Friedman of Sportsnet reports.
Pyatt served as a healthy scratch against the Capitals on Saturday.
Pyatt was held out of Monday's game against Dallas with flu-like symptoms, Bruce Garrioch of the Ottawa Sun reports.
Pyatt's assist Wednesday marked the first time he'd scored a point since Nov. 24.
Pyatt had an assist on a third-period goal in Friday's 4-3 overtime win over Colorado in Sweden.
Pyatt (ankle) is listed on the Senators' training camp roster in preparation for the 2017-17 season.
Pyatt signed a two-year contract extension with the Senators on Monday worth an average of $1.1 million per season, Bob McKenzie of TSN reports.