All the lending to commercial banks is secured lending, they have to provide collateral to the ECB. The less good quality stuff is lent by individual central ba

All the lending to commercial banks is secured lending, they have to provide collateral to the ECB. The less good quality stuff is lent by individual central banks, so governments underwrite it. There is no unsecured buying of bank debt (banks can use covered bonds as collateral but again that is secured). And the LTRO is only three years. So it is not like you suggest at all.