The standard approach for crossing peripheral CTOs is to use a combination of hydrophilic guidewires and catheters. The path is either intraluminally or in most cases at least partially subintimal. This standard approach with a guidewire-tip as leading point (“wire first”) to cross CTOs has a success rate of about 80%. We hypothesize that a “catheter first” approach, using the catheter alone for the entire recanalization till re-entering the vessel is less traumatic and might lead to a longer intraluminal recanalization due to a softer leading point. Based on this assumption we analyzed the success and duration of this approach with a gradual step-up approach from catheter tip to guidewire front-end to guidewire back-end. To the best of our knowledge, no studies measuring the time of recanalization of lower extremity CTOs using conventional devices were published yet.
Data of 46 consecutive chronic total iliaco-femoro-popliteal occlusions in 43 symptomatic patients treated by percutaneous transluminal angioplasty were collected prospectively between May 1st 2014 and June 30th 2016 and evaluated retrospectively. Chronic occlusion was defined as clinical symptoms or imaging features lasting more than 1 month.
Patient age and gender, diabetes status, localization of occlusion, occlusion length, duration of symptoms, severity of vessel calcification, and recanalization time were assessed.
Technical success was defined as placement of a catheter beyond the distal end of the lesion into the true lumen, confirmed by contrast injection.
All 46 CTOs were successfully recanalized. In 22 cases (47.8%) recanalization was successful with the catheter tip only without the use of a guide wire. In 17 cases (36.9%) the guide wire was used in addition to the catheter. Localization of occlusion did not have an effect on the recanalization technique (p = 0.915). The mean rank for length of occlusion was not significant for different recanalization techniques (p = 0.095). The success rate for the catheter only approach was lower for higher grades of calcification (p = 0.008). There was no correlation between time of recanalization and length of occlusion (Pearson’s r = 0.004; adjusted R square = − 0.024; p = 0.980), diabetes (p = 1.000), sex (p = 0.244), or grade of calcification (p = 0.621). Recanalization time is significantly right-skewed with most recanalizations being successful under 30 min.
This “catheter first” approach is somewhat contradictory to the prevailing dogma of “wire first”. The concept to use the catheter to start a recanalization is well known, but to perform the entire recanalization including the re-entry seems possible and potentially less traumatic, likely leading to a longer intraluminal course. Our data shows that recanalization of occluded lower extremity arteries between the aortic bifurcation and the popliteal artery can be achieved in the majority of cases (84.7%) solely by using an angled angiographic catheter +/− glide wire.
We suggest a “5 min – 15 min – 30 min” rule on how long to attempt each recanalization technique. More precisely, we suggest trying 5 min with the catheter alone, then 10 min with the soft end of the guidewire and then switching to the stiffer back-end of the guidewire for another 15 min.