2. Cross boss for ISR
Cross Boss should be used in ISR CTO. Wire crossing of ISR CTO runs the risk of wire going underneath stent struts. Cross Boss within ISR segment prevents going underneath stent struts and allows rapid crossing of the CTO.
Since the cross boss catheter has a rather stiff tip, the use of a stiff tip wire to lead the cross boss into the ISR is preferred (such as a pilot 150 or a miracle wire). If the cross boss will not enter into the proximal cap of the ISR CTO, we should use a corsair or a small balloon to open up the proximal cap before continuing with Cross Boss. The Cross Boss should be used to cross the CTO until the Cross Boss distal end has either crossed the CTO or reached the distal stent edge. A XTR/XT wire should be used to wire the distal true lumen. If the wire cannot reach the distal true lumen after a short try, the Cross Boss should be deliver further distally to produce a subintimal space to set up for Stingray rentry.