IMPLANTATION OF ABSORB IN CHRONIC TOTAL OCCLUSION
OF IN-STENT-RESTENOSIS

The following 2 cases were presented in Asia PCR(SingLive) on 23rd January 2015 by Dr. Tan Chong Hiok

Bio-Absorbable stent

• Stents have been used to keep narrowed or blocked arteries opened for the last 20 years
• They have always been made of metals which means that they will always remain in the artery implanted forever
• Recently new materials have been used for these scaffolds which will ‘dissolve’ over a 2 year period
• That means that at the end of 2 years, no traces of the scaffold remains
• Time has been ‘turned back’ and the artery is back to its original un-diseased state

Abbott and Elixir

• Presently there are 2 bio-absorbable available in Singapore
• The ‘Absorb’ by Abbortt and ‘DESolve’ by Elixir
• Both are made of Poly-Lactic acid
• They have generally been used in simple cases
• The following 2 cases are complex intervention utilising the Absorb stent

CASE 1 – BMS ISR

• 68 Yr gentleman
• 2008 Bare metal stent used to treat the original RCA CTO
• In 2010 there was in-stent-restenosis which was treated with drug eluting balloon
• In 2014 he presented again with chronic total occlusion of the repeated in-stent-restenosis
• He was suffering from angina

Crossing the CTO

• Using a 2.5 x 15mm OTW balloon as anchor/support
• Fielder XT-A crossed the CTO segment

Sequential balloon dilatation

• Dilatation of the occluded vessel was performed with sequentially larger balloons
• Starting with Sprinter Legend 1.25 x 12 at 14 atm
• Then Sprinter Legend 2.0 x 12 at 14 atm
• Finally Kaneka Fortis 3.25 x 18 up to 22 atm
• However, the mid RCA could not be adequately dilated

Let’s try cutting balloon

• Using Flextome 3.5 x 10 inflated up to 14 atm
• Full expansion still could not be achieved

Still looking hazy

• After repeated cutting balloon dilatations
• There is still a little haziness at the mid RCA

Let’s try Absorb

• Placement of Absorb 3.5 x 28mm BVS

After the Absorb the mid RCA looked better. However, the ostium is not well expanded

Final angiogram

• After placing another Absorb 3.5 x 18 in the ostium RCA
• Post dilated with 4.0 x 15 mm NC balloon up to 17 atm
• RPL stented with Xience 2.5 x 38
• The artery looked fully revascularised

CASE 2 – DES ISR

• 2nd case is again in RCA
• In 2012 the RCA was treated with DES from pRCA to RPDA
• Drug-eluting balloon was used to treat the RPL

CTO was Crossed with Gaia 2nd on Corsair

• After 3.5 NC along RCA
• Kissing balloon 2.5 into the PRL and PDA
• The RPL after the PDA still looking very stenosed

Anchoring balloon placed in PDA

• Squeezed an Absorb 2.5 x 18 into RPL
• Re-crossed into PDA finished with kissing balloon

• The RPL now looks more respectable
• But the prox-mid RCA still not ideal

Another Absorb in proximal RCA

• Absorb 3.5 x 28 placed in pRCA up to 14atm

LAO final angiogarm

AP cranial

Options for treatment in these cases

• Leave them as they are after NC and cutting balloon
• Treat with Drug eluting balloon – But the post dilatation result was not idea
• DES – 2-3 layers of permanent metal
• BVS – Hopefully it dissolves leaving single layer of Metal and a big lumen
• Acute result looks acceptable
• Long term result presently unknown