2024, Number 2
Overcoming an under-expanded and undilatable stent
Full text
10.35366/116274
Language: English
References: 7
Page: 50-53
PDF size: 219.53 Kb.
ABSTRACT
Underexpansion is an important issue for interventional cardiologists in terms of long term results. Herein we report a successful rotablation of an under-expended stent struts. The patient was a 75 years old female with a history of Percutaneous Coronary Intervention (PCI) on Left Anterior Descending Artery (LAD) with 2 overlapping drug eluting stents a week ago in another center. Unfortunately, the stents were deployed without proper lesion preparation in heavily calcified lesions and hence the stents couldn't be dilated properly after deployment. The stent struts were successfully rotablated with 1.5 and 1.75 burrs respectively followed by subsequent stenting. The patient was discharged uneventfully. Under-expansion of a stent generally arises from inadequate lesion preparation. Impaired healing secondary to under-expanded stent struts is the main cause of re-stenosis in the short term. Hence adequate pre-dilatation especially in heavily calcified lesions is of quite importance. More sophisticated techniques such as Non-Compliant balloon (OPN), rotablation, shock wave balloon and laser should be used for adequate pre-dilatation when conventional balloon pre-dilatation methods fail. These methods can also be used for dilatation of an under-expanded stent. Consequently, under-expansion of a stent is one of the leading causes of stent restenosis. Rota-ablation can be used to debulk the under-expanded stent struts and hence prevent possible short term restenosis.INTRODUCTION
An under expended stent is a nightmare for an interventional cardiologist. A malapposed stent is the main cause of short time re-stenosis. Hence implanting the stent after adequate pre-dilatation is of great importance. Especially in heavily calcified lesions, more sophisticated techniques such as OPN balloon, rotablation, shock wave balloon and laser should be used for adequate pre-dilatation when conventional balloon pre-dilatation methods fail. Herein we report a case of successful rotablation of an under-expended stent struts.
CASE PRESENTATION
The patient was a 75 years old female with a history of Percutaneous Coronary Intervention (PCI) on Left Anterior Descendent (LAD) coronary artery with two overlapping drug eluting stents a week ago in another center. Unfortunately, the stents were deployed without proper lesion preparation in heavily calcified lesions and hence the stents couldn't be dilated properly after deployment. The first operator implanted a 2.75 stent via insufficient pre-dilatation in LAD which was severely under expanded and post dilation with a 3.0 × 12 mm Non-Compliant (NC) balloon up to 35 atm had failed. The stents were malapposed and under-expanded so the patient was referred to our clinic for bailout management.
In our center, first NC balloon with 40 atm and then OPN balloon with 42 atm were performed but both failed. Since shock wave and laser system were unavailable rotablation of the under-expanded stent struts was our next approach. At first the wire was exchanged with a soft rota wire and then the rotablation was performed with 1.5 burr. After multiple rota runs and aggressive NC balloon post dilatation, the rota burr was upgraded to 1.75 (Figure 1). The rotawire was exchanged with an extrasupport rotawire over the microcatheter to gain more support for different rota burr and change the contact points of the burr.
After multiple rota and balloon post dilatation IVUS was performed to evaluate the lesion and fracture in the previous stent, ablated previous stent struts and relative debulcking in calcium burden were detected (Figure 2). Hence stenting over ablated and fractured previous stent was decided. A 3.5 × 38 mm drug eluting stent was deployed at 20 atm (Figure 3).
DISCUSSION
This paper reveals that rotablation of under-expanded stent struts can be performed as a bail-out option when the first choice maneuvers such as high pressure Non-Compliant (NC) and OPN balloon inflations fail.
Under-expansion of a stent due to inadequate lesion preparation poses a great challenge for the interventional cardiologist and generally there are a few strategies to fix this problem. The possible maneuvers are leaving the under-expanded stent as it is, prolonged high pressure NC balloon inflation, OPN balloon, rota-ablation of the under-expended stent, shock wave balloon and laser or surgery as a last resource.1-4
In this case, due to absence of laser and shock wave, our choice was rotablation of the under-expended stent struts. The greatest concern with longitudinal stent ablation is to slip through the under expanded stent without ablating the metal and leaving the burr immovable. Hence in this case the burr advanced more gradually and more carefully than our usual approach. During the procedure, multiple runs and NC balloon dilatations were performed. Changing distal wire position and exchange between soft and extra support rota wire facilitated the contact between the burr and the stent. The other concern is slow flow and no reflow due to metallic debris and stent thrombosis due to heat generation so short runs were preferred in our case. Thankfully, none of these complications happened in our case probably due to our particular attention about keeping the rota runs as short as possible. In line with our current case, recent Optical Coherence Tomography (OCT), Intravascular Ultrasound (IVUS) and also electron microscopy studies have also shown that stent ablation by rotablation can remove under-expanded stent struts.5-7
CONCLUSIONS
Consequently, under-expansion of a stent is one of the leading causes of stent restenosis. Under-expansion of a stent has a challenging consequences for the interventional cardiologists. It could cause of stent restenosis. There are some options to maintain stent restenosis and rotablation is one of them. Rotablation can be used to debulk the under-expanded stent struts and hence prevent possible short term restenosis.
REFERENCES
AFFILIATIONS
1 Erfan General Hospital, Department of Cardiology, Tehran, Iran.
2 Samsun University, Faculty of Medicine, Department of Cardiology, Samsun, Turkey.
3 Masshad University of Medical Sciences, Faculty of Medicine, Department of Cardiology, Masshad, Iran.
4 Ege University Faculty of Medicine, Department of Cardiology, ?zmir, Turkey.
Declaration of patient consent: the patient\'s consent have been added.
Funding: no financial support was received for this study.
Declaration of patient consent: the authors declare no conflict of interest.
CORRESPONDENCE
Melisa Uçar, MD. E-mail: mmelisaucar@icloud.comReceived:12/22/2023. Accepted: 05/03/2024.