Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_3609_Библиотеки_им_академика_М_И_Перельмана

the single run-off vessel (Fig.19.1). A 7-French sheath was inserted antegrade in the left common femoral artery and for embolic protection a SpiderFX™ lter was inserted distally in the left popliteal artery (Fig. 19.2, red arrows). A Jetstream™ 2.4 mm atherectomy device was employed (Fig.19.2, black arrows) with two slow passes done with the blades down followed by two slow passes with the blades up. 6mm in-stent plain balloon angioplasty was performed, but due to residual stenosis (Fig.19.3) distal extension with two Supera™ stents in the P2 and P3 popliteal segments, and proximal extension in the left SFA with a drug-coated stent (Zilver™ PTX) was required. The ow along the left femo­ropopliteal axis was restored, with preservation of patency of the single-vessel tibial run-off (Fig.19.4).

The primary complication during atherectomy is distal embolization. Both brotic and calcic atherosclerotic plaque are vulnerable to fragmentation and embolization, along with softer, more thrombotic components of chronic total occlusions. The embolized material will frequently lodge at a stenosis distal to the treatment segment, turning it into an apparent occlusion on check angiography. The rst sign of distal embolization may be a sudden distal ischaemic lower-limb pain reported by the patient, or it may be clini­cally silent. If distal embolization is suspected, the rst two priorities are to maintain patient comfort by upgrading anal­gesia if they are awake and to ensure that heparinization is adequate to avoid thrombosis of the arteries distal to the location of the embolus. Attention should then be turned to mapping the location of the embolus to facilitate treatment. Although angiography may show an abrupt cut-off of, e.g., a tibial artery, crossing the cut-off point with a hydrophilic­tipped guidewire and advancing an appropriately sized cath­eter a short distance beyond the cut-off point to inject contrast should localize the proximal and distal extent of the embolus. Depending on the nature of the embolus, administration of a small dose of recombinant tissue plasminogen activator may be helpful in lysing thrombotic embolus or de novo thrombus forming distally. However, if safe to do so, attempts to aspi­rate the thrombus with a catheter should be made. This is achieved by advancing a catheter immediately beyond the location of the embolus, attaching a 20mL Luer-lock syringe to the catheter hub and applying negative pressure, then immediately retracting the catheter slowly as the tip crosses the location of the embolus and then more quickly to com­pletely remove it from the body. A 6-French aspiration cath­eter is usually appropriate for the femoropopliteal segment; however, a 4-French catheter may be required if embolus is lodged in tibial arteries less than 2mm in diameter. Early and generous local administration of isosorbide dinitrate is rec­ommended to reduce spasm caused by rapid catheter manip­ulations during the aspiration manoeuvres. If the embolus cannot be lysed or aspirated, balloon angioplasty of the seg­ment where it has lodged can be performed, however there is risk of fragmentation and more distal travel of these frag­ments into the pedal circulation. Multiple trashes of tiny embolic particles into the pedal microcirculation can cause the “no re-ow” phenomenon, in which the named tibiopedal arteries are seen to be patent following atherectomy/angio­plasty but with extremely sluggish ow. Catheter aspiration cannot be employed here, and if on-table local thrombolysis

and nitrate administration is not successful in restoring brisk ow, the patient may require a 12–24-h period of treatment with an intravenous heparin infusion to allow some endoge­nous brinolysis and/or early distal collateralization to occur.