a 65-year - old female patient presented in january 2013 with unstable angina . coronary angiography showed a severely calcified long lesion of the proximal and mid segments of the left anterior descending coronary artery [ video s1 ( please see enhanced content link on title page ) ] . in view of the angiographic findings
, a decision was taken to do a planned rotational atherectomy ( ra ) , which was performed with the rotablator ( boston scientific ) using 1.5 then 1.75  mm burr sizes , followed by implantation of two overlapping 3.0    28  mm bioresorbable scaffolds ( brs ) ( absorb , abbott ) .
post - dilatation was done using a 3.0  mm non - compliant balloon at 20  atm .
intravascular ultrasound ( ivus ) showed a good result with a minimal overlapping zone ( fig .  1 ) .
a coronary angiography done 10  months later due to recurrent angina revealed a significant restenosis of the implanted brs .
optical coherence tomography ( oct ) showed a diffuse homogeneous intra - scaffold neointimal tissue with a minimum luminal area of 1.59  mm at the distal brs and 1.98  mm at the proximal one ( fig .  2 ) .
a scoring balloon angioplasty using a 3.0    10  mm angiosculpt scoring balloon ( angioscore ) was performed followed by 3.5    20 and 3.0    20  mm pantera lux ( biotronik ) paclitaxel eluting balloons ( deb ) in the proximal and distal scaffolds , respectively .
oct clearly showed the neointimal cuts achieved by the scoring elements ( white arrowheads , fig . 
3 ) , neointimal disruption with some intraluminal material ( yellow arrowheads , fig .  3 ) and lumen expansion . at 2  years after balloon angioplasty ( almost 3  years after brs implantation )
, the patient remained asymptomatic and a scheduled angiographic control showed a patent vessel with no significant lesions .
oct showed favorable evolution of the neointimal damage caused by the scoring balloon and maintenance of the initial lumen expansion , with partial resorption of the scaffold struts for which footprints were still visible ( fig . 
c shows final result after implantation of two 3    28  mm bioresorbable scaffolds , with a good result in the final intravascular ultrasound ( d ) 
 fig .  2in - scaffold restenosis . in a , b
, the angiogram shows diffuse in - scaffold restenosis in the proximal and distal scaffolds .
b is the final angiographic appearance after scoring balloon / drug - eluting balloon treatment .
optical coherence tomography ( oct ) images ( a ) and ( c ) show homogeneous intra - scaffold tissue .
3final result after scoring balloon / drug - eluting balloon treatment . in a , b , the final angiographic appearance after balloon - only treatment of the restenosis .
intraluminal material caused by neointimal dissection is also observed ( yellow arrowhead ) 
 fig . 
4follow - up angiogram and optical coherence tomography ( oct ) 2  years after treatment of the in - scaffold restenosis . a is done in a zone of muscular bridging showing the absence of significant stenosis in that area .
the favorable evolution with disappearance of the neointimal damages caused by the scoring balloon is clear in the oct images b  f , which also show partial resorption of the scaffold struts 
  baseline angiogram and procedure . a baseline angiogram showing a calcified stenosis of the proximal and mid lad .
c shows final result after implantation of two 3    28  mm bioresorbable scaffolds , with a good result in the final intravascular ultrasound ( d ) in - scaffold restenosis . in a , b
, the angiogram shows diffuse in - scaffold restenosis in the proximal and distal scaffolds .
b is the final angiographic appearance after scoring balloon / drug - eluting balloon treatment .
optical coherence tomography ( oct ) images ( a ) and ( c ) show homogeneous intra - scaffold tissue .
the b represents oct cross section of the overlapping zone final result after scoring balloon / drug - eluting balloon treatment . in a , b , the final angiographic appearance after balloon - only treatment of the restenosis .
d  f lumen expansion is clearly visible via optical coherence tomography ( oct ) .
intraluminal material caused by neointimal dissection is also observed ( yellow arrowhead ) follow - up angiogram and optical coherence tomography ( oct ) 2  years after treatment of the in - scaffold restenosis .
a is done in a zone of muscular bridging showing the absence of significant stenosis in that area .
the favorable evolution with disappearance of the neointimal damages caused by the scoring balloon is clear in the oct images b  f , which also show partial resorption of the scaffold struts informed consent was obtained from the patient for being included in the study .
the most important proposed advantage of brs over the current metallic stent technology is to restore the natural physiologic vasomotor function and to hinder late thrombotic events . in our case ,
the initial treatment strategy was using ra in disrupting the continuity of intravascular calcium rings facilitating brs implantation and potentially achieving a stent - free vessel in the long - term .
ra is a safe and effective method for lesion preparation before stent implantation   and its use could be extrapolated before brs implantation , where lesion preparation is of utmost importance .
however , additional vessel injury with ra has been previously suggested to be associated with increased late lumen loss . in our case , this mechanism appears very likely because the in - scaffold restenosis was diffuse and affected both implanted brss .
the rate of target - lesion revascularization ranges from 1 % to 3.3 % after brs implantation [ 3 , 4 ] .
the most often used method for the treatment of in - scaffold restenosis is a drug - eluting stent ( des ) , but there is no sufficient data supporting this approach , and the optimal treatment strategy is still uncertain .
drug - eluting balloons have demonstrated their efficacy in treatment of restenosis following metallic stent implantation .
additionally , scoring balloon predilatation prevents balloon slippage and enhances local plaque disruption , and its use in combination with deb angioplasty improved angiographic results in the isar - desire 4 study . in this reported case , by adopting the scoring / paclitaxel - coated balloon strategy , we tried avoiding a metallic stent implantation targeting to maintain the long - term benefits of brs .
however , between 3 and 6  months and as a consequence of hydrolysis of ester bonds , the device loses its structural continuity , and the radial strength decreases considerably until it is lost .
this loss of radial force is suspected to be source of recoil when balloon dilatation is performed alone after 6  months . in this patient ,
the vessel wall 10  months after brs implantation opposed minimal recoil to the scoring / deb treatment , which achieved sufficient stable lumen size and remained effective until 2  years of follow - up . in our case
we tried to highlight the possibility of a balloon - only treatment of a restenosed bioresorbable scaffold . with an adequate initial lesion preparation
, this strategy can be even applied in severely calcified coronary lesions . finally , given the limited data , there is a need for further examination of the place of ra before brs implantation and the optimal treatment strategy for in - scaffold restenosis from future rcts .
 we report a case of a 65-year - old female patient treated with an everolimus - eluting bioresorbable scaffold ( brs ) after rotational atherectomy of a severely calcified lesion of the left anterior descending coronary artery . 
 the implanted brs restenosed 10  months after implantation and was treated with a scoring balloon followed by drug - eluting balloons with good immediate and long - term results . 
 to the best of our knowledge , this is the first report of a balloon - only treatment of a restenosis occurring more than 6  months after brs implantation ; angiographic and optical coherence tomography images after treatment and at two - year follow - up are presented . 