The potential hazard of a non-slip element balloon causing distal longitudinal stent deformation: the first clinical experience and in vitro assessment.

BACKGROUND: A new complication, longitudinal stent deformation (LSD), is increasingly reported with recent intracoronary stent designs. There have been experiences of unusual cases of distal LSD caused by entrapment of a Lacrosse® non-slip element (NSE) balloon (Goodman Co., Ltd., Nagoya, Japan), which has three flexible nylon elements to prevent slippage. Accordingly, the aim of this study is to report the clinical experience of distal LSD caused by the NSE in the documented center and to investigate the incidence and mechanisms involved. METHODS: Coronary intervention cases were retrospectively reviewed using the NSE balloon in hospital between May 2014 and June 2017. In bench testing, distal LSD was reproduced in a silicon tube model to identify its mechanism. RESULTS: A total of 95 patients with 107 lesions underwent coronary interventions with NSE. Of these, 72 lesions (12 de-novo lesions and 60 in-stent restenosis) were treated using in-stent dilatation. Two distal LSD cases occurred, representing an incidence of 2.78% (2/72) among all procedures; 16.7% (2/12) of the de-novo lesions developed LSD. In vitro experimentation allowed indentification of the mechanisms involved and bailout strategies. CONCLUSIONS: This is the first study to evaluate NSE balloon catheter entrapment complicated by distal LSD in which reconstruction of the deformed stent and retrieval of the NSE could be achieved successfully. There is a potential hazard for distal LSD during post-dilatation using the NSE balloon due to its structural characteristics. Careful assessment is needed to prevent this complication.

The effectiveness of super-selective injection with anchor balloon technique for collateral channel assessment.

The careful assessment of collateral channels is important for a retrograde approach for a chronic total coronary occlusion (CTO). This case report describes a percutaneous coronary intervention for CTO of the distal right coronary artery with good collateral circulation. All visible collateral channels failed by the retrograde approach; however, the procedure was successful using the distal atrial circumflex (AC) channel. Although this distal channel was poorly visualized on standard coronary angiography, it was clearly contrasted retrogradely from the CTO exit using a super-selective injection through the proximal AC channel as the antegrade flow was obstructed by the anchor balloon. This case highlights a unique super-selective injection with anchor balloon technique for collateral channel assessment.