BEGIN TRANSACTION;

BEGIN TRY

    -- Some code

    COMMIT TRANSACTION;

END TRY

BEGIN CATCH

    ROLLBACK TRANSACTION;

END CATCH;

BEGIN TRANSACTION

DECLARE @usedrecords XML;

SET @usedrecords = N'<Record ID="388" />';

EXEC dbo.pd_trn_Transaction @UsedRecords

ROLLBACK TRAN

 DECLARE @res INT;

        EXEC @res = sp_getapplock @Resource = 'TransactionCheckLock' ,

                                  @LockMode = 'Exclusive' ,

                                  @LockOwner = 'Transaction' ,

                                  @LockTimeout = 10000 ,

                                  @DbPrincipal = 'public';

        IF @res NOT IN ( 0, 1 )

            BEGIN

                RETURN -2;

            END;

PRINT 'BEFORE TRY'

BEGIN TRY

    BEGIN TRAN

     PRINT 'First Statement in the TRY block'

     INSERT INTO dbo.Account(AccountId, Name , Balance) VALUES(1, 'Account1',  10000)

     UPDATE dbo.Account SET Balance = Balance + CAST('TEN THOUSAND' AS MONEY) WHERE AccountId = 1

     INSERT INTO dbo.Account(AccountId, Name , Balance) VALUES(2, 'Account2',  20000)

     PRINT 'Last Statement in the TRY block'

    COMMIT TRAN

END TRY

BEGIN CATCH

    PRINT 'In CATCH Block'

    IF(@@TRANCOUNT > 0)

        ROLLBACK TRAN;

    THROW; -- raise error to the client

END CATCH

PRINT 'After END CATCH'

SELECT * FROM dbo.Account WITH(NOLOCK)

GO

You can't kill/rollback a transaction from another session without killing the owner session.

I think, allowing to kill/rollback a transaction from another user's session means many design and security rule violations because it requires entering another user session (in the context of the current sql server engine design). That's probably why it is not implemented.