[3] He began his professional career in the Lebanese Premier League for Nejmeh in 2015, before playing for Shabab Arabi and Safa.

[5] On 28 October 2020, Mehanna and Sevan mutually terminated his contract; he had scored two goals and made one assist in three league games.

[10] After breaking his contract with Nejmeh on a mutual agreement in September 2024, Mehanna returned to Bourj ahead of the 2024–25 Lebanese Premier League season.

Mehanna represented Lebanon internationally at under-20 level at the 2017 Jeux de la Francophonie, scoring a goal against Guinea.

[11] He made his senior debut on 24 March 2022, in the 2022 FIFA World Cup qualification, coming on as a substitute in a 3–0 defeat to Syria.