June 21st 2018

To Move Forward, You Have To Let Go : Dealing with knotted wire and disrupted stent

Category: Complication, Coronary,



Wishnu Aditya Jakarta Heart Center



Wishnu Aditya Jakarta Heart Center

Case: A 51 years old male was admitted with Acute NSTEMI. He had Type II Diabetes, hypertension, and history of ischemic stroke. His renal function was mildly declined (creatinine 1.5, eGFR 48).

He underwent cardiac catheterization on the third day of hospitalization and was found to have triple vessel coronary disease. The left main artery was large and short. There were significant diseases in proximal to distal LAD (70-90% stenosis), proximal and distal LCx (75, 90% stenosis), and also in distal RCA and mid Right PDA lesion.


Video 1a. Significant lesions in proximal to distal LAD, proximal and distal LCx, distal RCA

Video 1b. Significant lesions in proximal to distal LAD, proximal and distal LCx, distal RCA

Video 1c. Significant lesions in proximal to distal LAD, proximal and distal LCx, distal RCA

Video 1d. Significant lesions in proximal to distal LAD, proximal and distal LCx, distal RCA

Patient rejected CABG and asked for PCI to be done immediately. Target vessel was proximal to distal LAD and proximal LCx .


Image 1 A & B: Target vessel for PCI: Proximal LAD, Proximal LCx, Mid-distal LAD


             PCI was performed with JL 3.5/6Fr Guide. Workhorse wire was inserted to distal LAD and LCx. First DES (2.5x38 mm) was implanted in mid-distal LAD, with distal stent edge located in D3 bifurcation. Second DES (2.75x24 mm) was implanted in osteal to mid LAD (non overlapping). Proximal stent was post dilated with (3.5x15 mm) NC Balloon.


Video 2a. First stent placement in mid-distal LAD

Video 2b. Second stent placement in osteal-proximal LAD

          While performing post dilation guide catheter was very unstable. Distal LAD wire was noticed to be knuckled, and sometimes went to D3 branch. Wire felt heavy on reposition attempt. Checking on cranial position, stent was retracted from its original position and distorted.


Image 2 A - B: Knuckled wire in distal LAD sometimes went to  D3 because the guide was unstable


Video 3. Distal LAD stent appeared to be retracted and distorted with wire knotted to distal stent position

Image 3. Compared to original deployment position


          Standard maneuvers failed to release the knotted wire. Additional workhorse wire was inserted crossing the disrupted stent to secure distal LAD. Step dilation was performed using 1.0 x 5 mm and 1.2 x 10 mm normal balloons in knotted wire. 3.0 x 15 mm NC Balloon was inflated in proximal part of disrupted stent (To add more grip).


Image 4 A - D: Protecting distal LAD with additional wire and step dilation in knotted wire using small CTO balloons. NC 3.0 balloon was used to add more grip to proximal stent


          After dilation, wire was able to be released by using this technique: Loosen the knotted wire, keep turning the wire in one direction (clock / counterclock) – the wire de-knotted by itself. This technique was suggested to the operator by the scrub nurse (A Senior lady, her hobby was knitting).


Video 4. Pulling will only make the knot tighter. Do not do this

Video 5. In this case, De-tensioning the wire while keep rotating in one direction allowed the knot to release itself

          Next step is dealing with a disrupted stent. Step dilation was performed through new wire using 1.0 x 5 mm, 1.2 x 10 mm, and 2.0x20 mm normal balloons, crossing disrupted stent struts.


Image 5 A – B: Step dilation in new wire across disrupted stent


2.25x24 mm DES was able to cross disrupted stent and inflated. This stent was then inflated with a 3.5x15 mm NC balloon. Final 3.0 x 28 mm DES was implanted in proximal LCx. Final angiography showed TIMI 3 flow to distal LAD and distal LCx. 

Video 6a. A 2.0x20 mm balloon was able to cross disrupted stent struts, followed by 2.25x24 mm DES and postdilated with 3.5 NC Balloon

Video 6b. A 2.0x20 mm balloon was able to cross disrupted stent struts, followed by 2.25x24 mm DES and postdilated with 3.5 NC Balloon

Image 6. Last DES implanted in proximal LCx


Video 7a. Final Angiography

Video 7b. Final Angiography

Image 7. Procedure Summary: Knotted wire was pulled and caused stent disruption. New wire was put across disrupted stent to protect distal access. After knotted wire successfully retracted, new stent was able to cross disrupted stent and deployed



Discussion and learning points:

          This is a complication case caused by several factors: Short LM, unstable guide, stenting in mid bifurcation, knuckled wire, and probably not good enough wire handling. One important lesson in dealing with a wire knot is: Loosen, don't pull. We can try to use small balloon to open more space – after that, keep rotating in one direction and hopefully the wire will untie by itself.

Newer generation stents have more thin strut, which likely more prone to disruption. But it also makes stenting over disrupted stent possible - after a proper step dilation. To avoid knotted wire complication like this case: Never underestimate a knuckled wire tip – especially in a stented lesion.

 What I will probably do next time in similar situation: Use a more stable guide, not putting stent in the middle of bifurcation, and be more careful with guidewire handling. 


Author's Note:

Operator consulted to Sunarya Soerianata, MD and Doni Firman, MD when performing this case 

what the experts say


A Fauzi Yahya
The operator shared his innovative tips in handling the wire knot and disrupted stent during diffuse LAD intervention in diabetic patient with NSTEMI and renal dysfunction. There were some learning issues which could be discussed :
1. There was unclear view of LAD  due to the subselective contrast injection. A clear   diagnostic view would lead us to choose the right strategy
2. Although JL is the less supportive  GC but it is the better option for such short LM.  Sometimes a bit tortousity of the right subclavian artery make JL GC more unstable. Putting the wires into the LAD and LCX  would stabilize the GC. 
3. I would not do direct stenting unless I know  the plaque characteristic by IC imaging (IVUS or OCT) 
4. A knot can be formed due to agressive wire, knuckling or excessive torquing. Sometimes, advancing microcatheter to the point where the wire is knotted and gently pull on the wire would untangle it.
5. I prefer to stage in intervening the LCX lesion. Prolong procedure and a lot of contrast potentially compromise the good result which already had been achieved 
Thanks for sharing this case with us