Left coronary angiogram in PA (posteroanterior) cranial view showing totally occluded left anterior descending coronary artery stump (LAD stump). LMCA: left main coronary artery; Diag (diagonal branch of LAD); LCX: left circumflex coronary artery. The diameter of LAD is similar to that of the guide catheter. There is tight stenosis of another small branch seen running between the LCX and diagonal. It is not clear from this view whether it is a branch of LAD or LCX. Apparently it is a branch of LCX.
A floppy tipped guidewire has been passed and the total occlusion crossed with difficulty. An initial balloon dilatation has been done to facilitate the free movement of the guide wire. The floppy region of the guide wire is seen as more radio opaque and usually measures about 27 mm. There are two discrete markers at the ends of the balloon which are radio opaque. The balloon has been filled with dilute contrast prior to introduction, for visualisation during inflation. Guide catheter in the descending aorta has been marked. The tip is faintly visible above if the guide wire is traced backwards to the edge of the image.
Guide wire has been passed further into the LAD after the initial balloon dilatation. If the guide wire passes effortless and can be tracked into multiple side branches, it is an indication that it is in the true lumen. This verification is especially useful while opening up total occlusions, to prevent balloon inflation within a false lumen which may even result in coronary perforation. Check shots of angiograms will also help in identifying true lumen and extravasation if any. If coronary perforation does occur, it has to be tackled by keeping the balloon inflated (balloon tamponade) while surgical closure of the perforation is arranged. This will prevent hemopericardium and cardiac tamponade. Balloon tamponade will not produce ischemia in this situation because it was already a totally occluded artery. Sometimes it is possible to cover up a perforation by a covered stent.
Outline of stent in LAD soon after deployment, seen on fluoroscopic imaging. While taking a check angiogram after stent deployment, the image acquisition is started before injecting the contrast so that the stent is visualised before the vessel is opacified by the contrast. The guide wire is in situ, passing distally through the stent. It appears as if part of the stent in the region of the third set of markers has not been fully expanded. Incomplete stent apposition can increase the chance of stent thrombosis as well as restenosis later. Hence it is customary to post dilate the stented segment using a non-compliant (NC) balloon.
Left coronary angiogram in PA cranial view after stent deployment in LAD. The stented segment is more prominent than rest of the LAD because mild over inflation is given to obtain good stent apposition. This will reduce the chance of stent thrombosis and late lumen loss due to restenosis. Flow into the distal LAD is good. Segments distal and proximal to the stent should inspected carefully for any haziness which can due to dissection or local thrombus formation. If a dissection is noted, current option is to seal it off with another stent. In the earlier era, dissections were also treated by prolonged balloon inflations.
Stent outline seen on fluoroscopic image in lateral view. Imaging in multiple planes is mandatory, especially in orthogonal views, to look for incomplete stent expansion. Care should be taken to avoid misinterpretation of distortion due to the stent adaptation to tortuous vessels as incomplete expansion.
Stented segment of LAD in lateral view of coronary angiography, with stent standing out slightly in profile. Multiple projections are useful in assessing incomplete stent expansion.