In Lousanne, we learned about complications…

This Endovascular Cardiac Complication Workshop was organised by a group of people led by Prof. Eric Eckhout from CHUV Lousanne & Amir Lerman from Mayo Clinic, Rochester. There were quite a good number of international faculties including Patrick Serruys and a number of speakers from Mayo Clinic such as A. Lerman, C. Rihal, M. Bell and M. Kearn. Indeed this was the first time I ever heard about it, and as I have just found out, it was such an excellent event. The event was held at Lousanne, Switzerland.
The main theme of the conference was on presentation of complex cardiac cases and complications during cardiac intervention. Most of the cases were pertinent to coronary intervention, though interventional cardiologists these days naturally got involved with peripheral intervention, intervention in congenital heart disease and the new state of the art transcatheter aortic valve implantation.

Complete AV block following septal branch occlusion during PCI to LAD
One of the first cases presented was a lady who underwent PCI to Left Anterior Descending artery following acute coronary syndrome. The proximal-mid LAD had a bifurcation lesion involving a fairly large septal branch. Following stenting, it was noted that the septal perforator branch was occluded. Nothing was done to the septal artery in view of it being relatively small, and its sharp take-off.
As the patient was observed in the ward, she developed chest pain, then right bundle branch block was noted on the ECG though no ischaemic changes present. A few hours later, the patient was still complaining of mild chest pain, she now had left axis deviation on her ECG. On a second day, the patient went into asystolic cardiac arrest, recovery ECG showed complete AV block. She was treated with atropine and temporary pacing. Subsequently she was subjected to permanent cardiac pacing. However, the complete AV block disappeared when the patient was reviewed following discharge, about a month later.
Lesson: This is similar to post HCM ablation, when septal branch is (purposely) occluded, in one case report series it was suggested that the incident can be as high as 30%, though some may recover. It is a known phenomena, in patients who present with acute anteroseptal MI and develop complete AV block, more than likely he or she will require pacing as this block usually does not recover – in contrast to CHB associated with inferior MI or Right coronary artery occlusion.
However, the issue here is whether or not you do anything extra when a septal branch occlusion happen during PCI to LAD – because most of the time it may not result in any untoward consequence. Close observation is all required, in this particular case the patient developed serious ventricular standstill as result of the complete AV block.

Lucas device saved a life – temporarily…
Another case of a middle aged male presenting with anterior MI with cardiogenic shock, Ejection Fraction of 20%. Coronary angiography revealed chronic total occlusion (CTO) of LAD and RCA, and severe disease of proximal LCX. Immediate referral to the surgeon was made, but turned down as the patient was considered very high risk. Decision was made to proceed with attempted PCI to LAD/RCA but this failed. PCI to LCX was performed. Suddenly the patient went into ventricular fibrillation during balloon inflation of the marginal branch, followed by pulseless electrical activity (PEA).
Immediate resuscitation was administered, and a mechanical CPR device – LUCAS device was applied while the PCI was proceeded with. Successful stenting of LCX was performed, however there was no spontaneous return of circulation. Lucas CPR was continued, at this stage almost one hour was completed with no spontaneous output – however, good pressure wave observed with LUCAS compression. Subsequently, intraaortic balloon pump was inserted, and this improved the forward circulation, though the patient still needed external chest massage to maintain circulation. A bolus dose of adrenaline was given, this improved the circulation, with resultant lowering of cardiac output. Eventually circulation was re-established after this bolus and infusion dose of adrenaline. The patient was transferred to ICU and received central hypothermia treatment. She gradually recovered and weaned of ventilation a few days after. Unfortunately she later died due to cardiac failure.
The case was actually trying to illustrate the role of adjunctive support device during PCI – in this case, mechanical, automatic chest compression using LUCAS device enabled PCI to be carried out despite patient in cardiac arrest. However, audience response suggested several other options including Impella device, Etmo/portable bypass etc. There was one good comment from another delegate – suggesting that this case illustrate bad planning…AIBP should have been inserted right from the beginning to allow better support of circulation, especially in view of patient’s desperate LV function. There was also concern whether LUCAS device does work, one of the panellist queried if anyone had ever seen a patient who had been treated with LUCAS survived to hospital discharged. Erick Eekhout quickly responded in the affirmative.

What happened when a stent got lost?
Do not brush this aside, this one particular complication is awaiting to happen to any interventionalist, at least once or twice in your lifetime! It happened to me and I managed to get away from it.
During the conference, there were three interesting cases of stent dislodgement – all of them were very instructive.
The first from Singapore. A 52 year old lady presented with anteroseptal STEMI found to have a Diffuse, calcified mid LAD disease. There was also some disease and calcification proximally. Following predilation, there was difficulty advancing a biomatrix stent therefore it was retrieved. However, it was noted that the stent had dislodged from the delivery system, guidewire was still intact.
Gooseneck snaring was attempted twice but failed. Subsequently the operator decided to use wire entanglement technique. Three wires were passed and twisted over each other, making really good knot. Using this technique it was possible to pull the stent out of its dislodged location, to the catheter. The catheter was disengaged and removed from the aorta, pulled out to the iliac artery. Then it was realised, that the femoral sheath was only 6Fr therefore not possible to retrieve everything through it.
Next, the operator punctured the left groin and inserted an 8Fr sheath, the plan was to retrieve the stent system from the contralateral side. Before proceeding to do this, the operator thought he would casually check the left coronary system, just to see what happened since the stent removal. At this stage the patient was completely asymptomatic.
To his astonishment, the left coronaries were now in a completely bad shape, there was a large dissection involving the left main stem, the proximal LAD and the proximal LCX. What a nightmare, a complication followed one after another. Cardiothoracic surgeon was called. While awaiting the surgeon, they decided to intervene with the LCX by placing stent proximally, fortunately this was successful and good flow was restored to the vessel. The patient was then sent to OR. SVG to LAD was carried out and the stent removed from the right external iliac artery.
Fortunately the patient survived surgery, her LV function was well maintained and she had a good recovery following the surgery. The specimen from the stent retrieval was sent tot he pathology lab, and confirmed finding of intima, plus another unknown ‘object’ thought to be polymer from the DES.
It was thought that the reason for the stent dislodgement may have been due to the acute angulation between LAD and the catheter, or no coaxiality between the cathether and left main ostium.
Two comments worth noting: first, while the wire was still in the stent, why did the operator not consider other option such as using balloon (half inflated) to push the stent distally, or pass the balloon distal to stent then use it to extract the stent from the artery. The second comment was regarding the intervention technique, it was suggested to intervene with the LMS first, since this may make a better access to LAD.

If it was not there, it could have moved – mysteriously to the other side…
Another stent dislodgement case, in a patient who underwent PCI to mid RCA. There was difficulty crossing the mid lesion using biomatrix stent, and it was then noted that the stent dislodged. Snaring again had failed. Then suddenly the wire and the catheter all slipped and completely disengaged from the RCA.
The operator quickly reengaged the catheter, however strangely the stent could no longer be visualised in the RCA. Suddenly the patient complained of chest pain, and ECG showed ST depression on the anterior leads. The operator elected to complete PCI to RCA – this time using a cobalt chromium BMS and successful. Now left coronary angiogram was done, and this confirmed the stent had embolised to the LAD! There was some haziness suggesting the stent was thrombosed. Luckily they managed to retrieve the stent this time, using a snare.
The panellists remarked that this was a very unusual situation, since the stent could not be removed from the RCA by mechanical means, so how it suddenly embolised elsewhere? It was thought this could have been caused by the sudden catheter and wire movement causing the stent to jump out of the right system.

Poor angiographic system, low stent radio-opacity cause of stent lost?
The third case of stent dislodgement was presented by an interventionalist from Greece. This was a middle aged gentleman who underwent scheduled PCI of proximal RCA lesion. The RCA itself was large but tortuous and a little calcified. A relatively short BMS was advanced to the lesion, but difficult to cross. The next thing the stent was dislodged – but strangely it could not be located anywhere along the RCA. I must admit that the cine picture wasn’t great, they were using one of the old cardiac angiography system making picture quality so desperate.
Since the patient was okay, the operator decided to proceed with stenting the lesion, by first doing further predilation with a bigger balloon, followed by a short DES (4.0x18mm) and this successfully crossed the lesion and completed the stenting. The lost stent was still not located.
They then proceeded with IVUS. Miraculously, IVUS located the stent, at distal RCA, just before the crux! The operator elected to crush the stent with a short DES.
First comment from panellist – why they did not do a vigorous search of the lost stent – one of the recommendation is the do a full body fluoroscopy (head to toe). Another panellist jokingly said he should have learned from the second case and searched the left coronary! There was also a comment regarding what supposed to be done on the dislodged stent – though most of the audience agreed with crushing the stent – in view of its location which was very distal – many think a longer DES (generally slightly longer than the embolised stent) should be used. Crushing the stent was probably the most reasonable and time saving approach in this case, in view of severe tortuosity of RCA (impossible to retrieve the stent), and its distal location.
Again there was a query from one of the audience as to how the stent, which initially could not cross the lesion, suddenly dislodged and embolised distally? I thought this could have happened if the angulation factor played a role – it caused the difficult crossing, but with the acute angle, stent slipped outof the delivery system and hence travelled distally – this could easily happened since the rest of the vessel was huge and smooth.

So, if a stent get dislodged, what’s the best way to deal with it?
As mentioned above, this is one of the well known complication that awaits to happen to every interventionalist. Many factors – operator factor – excessive pushing, underestimating vessel tortuosity and inadequate predilation; patient factors – restless, calcified and tortuous vessel; and perhaps stent factors – though these days all stent come premounted – they can still dislodged with aggressive pushing, well first of all the stent is made to detach from the balloon, otherwise how it could be delivered? In the old time when interventionalist have to individually cream and mount the stent on the balloon – such incidence of stent dislodgement were more common – in the range of 1-3%, and many patients ended up with either peripheral gangrene or stroke.
So, the first thing to deal with a dislodged stent is – don’t allow it to happen. Lesion preparation with adequate predilation is essential. This doesn’t mean you cannot do direct stenting – in selective situation. Avoid excessive pushing. Tandem wiring may help straighten the vessel and allow better stent delivery. And (as in the case that I dealt with) – when you retrieve stent from the vessel – for instance when delivery was impossible, immediately check the stent is still intact before delivering it again.
If the stent is dislodged – do not panick and DO NOT pull out your wire or catheter. The worst scenario is when the stent is dislodged and free from the wire, you are easily talking about spending the next three hours fishing.
If the guidewire is still in – make up your mind whether to try retrieve the stent out or try to move the stent distally for deployment. Generally if the stent is proximal in location, trying to retrieve may be easier – use a small balloon – 1.25mm (and short in length), thread the balloon gently before the stent, inflate, then advance the balloon pushing the stent forward – this will attempt to move the stent distally. A bigger size like 1.5 may be better for bigger stent. If you are lucky enough and the stent move to the lesion, then it can be deployed. Deployment is done by gradual manner – use a fresh 1.25mm or 1.5mm balloon – shorter than stent length ideally, this time move the balloon inside the stent and once satisfied inflate it to maximum pressure. Then a bigger size balloon, in 0.5mm increment is introduced and similar process of inflation – steps repeated until full stent deployment accomplished.
If you decided to retrieve the stent while the wire still in, do the opposite, pass a small balloon of 1.25mm, pass the stent, inflate it then gently pull back – this may allow the stent to be retrieved towards the catheter. Not very ideal if the stent is in a distal location.
As for stent that has dislodged from the guidewire, the option is determined by the location is feasibility of retrieving the stent, for instance with snare. Snare may be possible if the stent is proximal or near the ostium. Mutiple wire manoeuvre to make a knot is an option. However, beware as illustrated in the first case this could result in serious vessel injury especially when the stent is will stuck to a calcified and severely angulated vessel. If the stent is distal, the easiest way, as demonstrated in the third case, is to crush the stent.
Rewiring? I had a case before when a stent was dislodged and the proximal end was sitting at the distal left main. Failing snare, we had little option but to try rewiring. Using tandem wiring technique, a lot of prayers, and Murphy’s law – we succeeded in rewiring the stent, then using the ‘balloon push’ technique above and managed to deploy the stent in the lesion.

Elegant reverse wiring technique, but ended with wire perforation and tamponade!
This case was presented by Prof. Fazila from Bangladesh. The case was an elective PCI of RCA which had a critical bifurcation lesion but difficult to cross the main vessel. The wire already went in to the RV branch. So a reverse wiring technique using Crusade catheter was used and the main vessel was successfully wired following this. Subsequent predilation and stenting went smoothly and good result obtained.
However, at the end of the procedure, the patient suddenly destabilised, severe hypotension developed. Echocardiography confirmed the presence of a fairly large tamponade – likely from a wire perforation of distal PDA branch. Pericardiocentesis was promptly carried out. Balloon was inflated for a few minutes to give temporary seal. The perforation was sealed with two coils, delivered by 6Fr Export catheter (no other available device).
There was an interesting discussion regarding whether or not heparin should be stopped. There was a concern that stopping heparin may lead to stent thrombosis. M. Bell from Mayo Clinic made this interesting statement: reversal of heparin, if needed should not cause problems to the DES! It is not required to prevent DES thrombosis, its only required for the procedure!
In short, reversal of heparin should be done (with protamine) – if you are not going to deploy coils or covered stent. If you have neither, and just going to balloon the vessel to hopefully seal the perforation, then heparin should be reversed – and do not worry of what could happen to the stent, as explained above! (of note, I have seen another case of vessel perforation before, successfully bailed out with an ordinary stent rather than a stent graft (covered stent)). Yes, you can inject fat, or improvised a covered stent using balloon (or fat…) over stent technique.

Beware of a bleeder
This is a sad story about an elderly lady that developed multiple complications resulting from a simple PCI procedure. She was electively scheduled for a PCI to LAD using right radial access. Unfortunately, something went wrong, there was a small perforation of her right radial, resulting in a big haematoma of her right arm. However, the operator decided to proceed with the procedure, using the left radial access. She was unlucky the second time, when the left radial also was dissected, thought the dissection was quite contained. The operator decided to proceed! And the PCI was completed. The left arm also ended up with a large and ugly haematoma.
As there was a need to put her under close monitoring, an internal jugular line was inserted, sadly she developed a large neck haematoma from this procedure. The next event happened, when, on the next day, patient fell from bed, and sustained a large cranial haematoma.
This was not the end of the story. On the third or fourth day or so, she complained of chest pain. She was not spared another procedure, promptly taken to the lab, a repeat coronary angiogram was done, stent was ok. However, due to hypertension, they decided to have a look at the renal arteries. Indeed she did have a severe left renal artery stenosis. Left PTRA was performed, and unbelievabley she developed another complication albeit a seriously life threatening one, when she had an abdominal aortic dissection as result of this renal stenting.
What is your take on this case? I personally thought that interventionalist could be more merciful than merely poking a patient here and there, especially when the need of doing so is not even justified! In this case, they probably should have stopped immediately the first radial complication happened. Afterall the procedure was elective – once a complication happened, beware, it doesn’t stop there, in this world there are people who are accident prone. More importantly as the rule goes, FIRST DO NO HARM.

Do not underestimate a simple lesion…
A fairly young lady underwent elective coronary angiogram on a Saturday. She was found to have a single vessel disease, a 60%-70% mid LAD lesion. The indication for the procedure was an angina symptom, no functional test was done previously. Since it was a Saturday, she was electively scheduled to undergo a PCI to mid LAD the following week.
PCI was undertaken, using Q catheter to engage the LAD. There was some difficulty engaging the ostium of the left main. Suddenly, when the first injection was taken, there was an extensive dissection at aortic root, LMS, LAD, LCX. A cardiothoracic surgeon was called. The opinion was to proceed with PCI since the patient was unstable then, and surgery is going to take a while before any decent revascularisation can be achieved.
Therefore PCI was performed. Wiring of both LAD and LCX were done without any problem, and the operator ‘thought’ both wires were in the lumen. Thankfully they were. LCX was stented first, then the LAD and subsequently the LMS – all went well and patient recovered without any further complications.
There was a question from a member of the audience, how sure you are that both wires were in the lumen, when such an extensive dissection had taken place? No IVUS was done. Eric Eekhout swiftly answered that, when injection is undertaken, and you can see the wire/wires distally ‘free’ and all the branches can be seen filled with the contrast – this is an angiographic sure way of determining the luminal position of the wires – a poor man’s IVUS…
Anyway, the moral of the story, a simple procedure does not necessarily mean it will not result in a complication. In fact, if you look at all those series of complications, they did happen in not so complex cases, and usually happen – on a late Friday or any unusual timing, when the operator least expect it, and perhaps thought that it’s going to be a quick, five minutes job…
In this particular case, the big question is, why PCI? There was no documented ischaemia on the first place, and there was no plan to perform IVUS or FFR to determine the significance of the lesion. Exposing patient to unnecessary risk when the procedure itself is questionable, and in this case patient had developed a life threatening complication.

Take Home Message
Complications in the cath lab is something that could happen to every operator. So, just be prepared for your time…some people say if you have not had complication, that means you have not done enough…but, the best way to manage a complication is not to have it on the first place. So treat every procedure with caution. More importantly, one has to develop his or her own routine in performing a procedure, and included in the routine is ‘allowance’ for making a mistake. Because, as they always say it – just like the case with a pilot and plane crash – usually a disaster is caused not by just a single mistake, it results from series of mistakes. Tired at the end of the day, performing a procedure in a rush, not focusing yourself, and not having a good routine, or contempt, feeling ‘it will never happen to me!’ – are all recipe for disaster. One of the best way of learning, is to learn from other people’s experience.