Introduction
Femoral antegrade approach is the most common for endovascular revascularization in patients with obliterating diseases of the lower limb arteries and lesion below the inguinal ligament. Indeed, transfemoral antegrade approach ensures high stability (“support”) during manipulations and better controllability of the instrument in lower limb arteries.
However, this approach is technically difficult and associated with more common serious complications compared to access via contralateral femoral artery [1]. The last option does not have the above-mentioned advantages of antegrade approach. Moreover, this technique is impossible in some anatomical features of abdominal aorta and iliac artery bifurcation, as well as after certain previous surgeries [2].
Thus, an alternative approach allowing safe and effective endovascular revascularization of the lower extremity is necessary in certain situations. The authors report treatment of a small group of patients with lower limb ischemia. Primary access through below-the-knee was used for endovascular intervention.
Material and methods
Twenty-three patients with obliterating diseases of the lower limb arteries underwent 25 endovascular revascularization procedures via primary retrograde distal approach. All interventions were carried out at the department of endovascular diagnosis and treatment of the Dzhanelidze Research Institute of Emergency Care. Primary retrograde distal approach was understood as retrograde access through below-the-knee arteries for recanalization and angioplasty without previous attempts of antegrade revascularization (Fig. 1). It should be noted that 1 procedure was performed in April 2014, other 24 interventions — for the period 2018 — 2020.
There were 16 (64%) men in our sample. Mean age of patients was 71.4 + 8.6 years (min 57 years, max 87 years). Diabetes mellitus was diagnosed in 15 (60%) patients.
In 20 (80%) cases, the indication for revascularization was necrotic ulcerative defects caused by chronic ischemia threatening loss of a limb. Ischemic resting pain was observed in 1 (4%) case. In 1 (4%) patient, maximum claudication distance was less than 50 m and conservative treatment was ineffective. In 3 (12%) cases, clinical manifestations were absent and endovascular intervention was preventive. The indication for preventive angioplasty was restenosis in femoral-popliteal segment over 70%.
In our opinion, there were prerequisites to refuse femoral antegrade approach in 22 (88%) cases (one or several factors increasing the risk of adverse events). Thus, a short passable zone over the damaged vascular segment (occlusion of superficial femoral artery within the ostium or ostial stenosis) in 13 (52%) patients seriously complicates both an access (not always possible guidewire insertion into the deep femoral artery and subsequent difficulties in inserting the introducer) and surgical manipulations per se (unstable position of introducer impairs controllability of instrument and results the risk of port dislocation). Apron belly in 8 (32%) patients significantly complicates surgical approach and increases the risk of introducer deformation and hemorrhagic complications. Postoperative scars within the common femoral artery puncture site (n=7, 28%) sometimes significantly complicate insertion of introducer and hemostasis. Puncture of common femoral artery with stenosis is unsafe regarding ischemic complications. Moreover, antegrade access is completely impossible in case of occlusion (n=5, 20%). “High” bifurcation of common femoral artery complicates antegrade approach, while its combination with ostial lesion of superficial femoral artery (n=4, 16%) makes an access very risky. In 1 (4%) case, distal patent anastomosis of cross-sectional femoral-femoral bypass graft was localized within the area of surgical approach. Previous stenting of common femoral artery was performed in 1 (4%) patient. Undoubtedly, these features do not exclude the possibility of femoral antegrade approach. However, there is a risk of damage to in-stent neointima or anastomotic area, while the effect of puncture on further patency of this segment is unclear. We also refused standard approach in 1 (4%) patient with residual disorders after previous ischemic stroke and insufficient compliance regarding the recommendations on strict bed rest with a straight lower limb. Indeed, high risk of bleeding was expected in this case (Fig. 2).
A combination of 2 adverse factors was observed in 14 (56%) patients. Six (24%) patients had 1 unfavorable sign, 2 (8%) patients — 3 factors. In other 3 (12%) cases, these signs were absent, and primary retrograde distal approach was a personal choice of endovascular surgeon (Fig. 3).
Femoropopliteal occlusions were diagnosed in 17 (68%) cases. Most often (n=9, 36%), length of occlusion was over 20 cm. Occlusion of at least one tibial artery was found in 17 (68%) cases. In 11 (44%) patients, occlusive lesion affected several levels (Table 1).
|
Angiographic characteristics of lesion |
Number of cases |
|
Femoropopliteal |
|
|
no lesion |
2 (8%) |
|
significant stenosis |
6 (24% |
|
occlusion |
17 (68%) |
|
occlusion over 20 cm |
9 (36%) |
|
Tibial segment |
|
|
no lesion |
3 (12%) |
|
significant stenosis |
5 (20%) |
|
occlusion of 1 artery |
7 (28%) |
|
occlusion of 2 arteries |
7 (28%) |
|
occlusion of 3 arteries |
3 (12%) |
|
Types of multilevel occlusions |
|
|
femoropopliteal segment + 1 below-the-knee artery |
5 (20%) |
|
femoropopliteal segment + 2 below-the-knee arteries |
5 (20%) |
|
femoropopliteal segment + 3 below-the-knee arteries |
0 |
|
aortoiliac segment + femoropopliteal segment + 2 below-the-knee arteries |
1 (4%) |
We paid a special attention to diameter and length of arterial segment before its puncture. These characteristics affect safety of access and stability of device position in the artery. Thus, vascular lumen width was over 2 mm and length of patent arterial segment was sufficient to insert an introducer or balloon catheter in all cases. In addition, surgeon was convinced that there were no significant arterial lesions within the puncture area or in distal segments requiring endovascular correction.
The patient was positioned so that his head was to the left of surgeon and his lower limbs were in front of surgeon. This arrangement ensured working in a familiar manner, when an approach zone was located in front of surgeon and equipment was placed in the right half of the table.
Position of the target limb depended on the artery selected for puncture. In case of approach through anterior tibial artery (n=17, 68%), the limb was placed so that the toes were oriented upward as much as possible. This position might be stabilized using a large roller outside of the foot. Similar position of the limb was used in case of approach through fibular artery (n=2, 8%).
Maximum rotation of the foot outwards is desirable for puncture of posterior tibial artery (n=6, 24%). If it was difficult with a straight limb, we applied slight flexion in knee joint and placed a large roller under the joint. These measures were effective to ensure sufficient rotation of the limb.
Puncture under angiographic control (Roadmap) or visual control with contrast agent injection through additional access was performed in 19 (76%) cases, puncture under ultrasound control — in 6 (24%) cases. In 23 (92%) cases, we performed 2 approaches (the main one for intervention and the additional one for angiographic control). Surgery and angiography through a single distal retrograde approach were performed in 2 (8%) cases. Introducer-free technique was used only in 2 (8%) patients. Six (24%) patients had occlusive lesion of the artery proximal to the puncture zone. It should be noted that artery was angiosomal in 13 (65%) cases. Moreover, the only patent below-the-knee vessel was punctured in 5 (20%) cases (Table 2).
|
Surgical features |
Number of surgeries |
|
Main approach |
|
|
artery |
|
|
anterior tibial |
15 (60%) |
|
posterior tibial |
6 (24%) |
|
fibular |
2 (8%) |
|
dorsalis pedis artery |
2 (8%) |
|
device within surgical approach |
|
|
introducer 6 Fr |
19 (76%) |
|
introducer 5 Fr |
2 (8%) |
|
balloon catheter 3,7 Fr |
2 (8%) |
|
introducer 4 Fr |
1 (4%) |
|
stent-graft delivery system 8 Fr |
1 (4%) |
|
Additional approach (introducer 5 Fr) |
|
|
radial artery |
14 (56%) |
|
brachial artery |
7 (28%) |
|
contralateral common femoral artery |
2 (8%) |
|
without additional approach |
2 (8%) |
|
Approach through a single patent artery |
5 (20%) |
|
Arterial occlusion proximal to approach |
6 (24%) |
|
Approach through angiosomal artery (20 patients) |
13 (65%) |
|
Antegrade recanalization and angioplasty of adjacent below-the-knee artery via the main approach |
6 (24%) |
Antegrade recanalization and angioplasty of adjacent tibial artery via distal approach were successfully performed in 6 (24%) cases (Fig. 4).
At the beginning of the study, we did not apply a compression bandage after distal approach and manual hemostasis in the operating theatre. Hemostasis was followed by angiographic control, and the patient was transferred to the department. However, there were 2 complications associated with the absence of compression. Thus, a bandage for 4 hours after surgery became a prerequisite. Patients were immediately allowed to walk within the ward.
Results
Retrograde distal approach was successfully performed in all cases. However, retrograde technique was not possible in all cases. Therefore, femoral antegrade access was performed in 2 (8%) cases. Retrograde recanalization of popliteal artery occlusion was failed in 1 case, and antegrade intervention was started. In the second case, conversion to antegrade intervention was required due to below-the-knee artery embolism after angioplasty of extended femoropopliteal occlusion. Thus, interventions were successfully completed through the distal retrograde approach in 23 (92%) cases. Additional conversion to antegrade intervention ensured favorable angiographic result in 100% of cases.
Blood flow through all below-the-knee arteries was restored in 10 (40%) cases, through 2 arteries — in 7 (28%) patients, 1 artery — in 8 (32%) cases. In 15 (75%) patients with necrotic foot ulcerative defects, we restored direct blood supply to the affected angiosome, in 5 (25%) patients — indirect circulation through collaterals.
Overall morbidity associated with retrograde approach was 12% (n = 3). Pulsatile hematoma within surgical approach was observed in 1 case. There were no clinical signs and hematoma 1.5 × 2.0 cm within the distal third of posterior tibial artery was detected during ultrasound on the 1st postoperative day. Considering small dimensions of hematoma, we applied a pressure bandage. According to ultrasound data the next day, hematoma thrombosis without contrast agent leakage was visualized. In another case, arteriovenous shunting into posterior tibial vein was diagnosed within the distal third of posterior tibial artery. There were no clinical manifestations. Compression bandage was effective that was confirmed by ultrasound. Finally, occlusion of the artery after puncture occurred in the third case (no contrast enhancement of the entire anterior tibial artery). No active actions were taken, since occlusion did not result any symptoms (Table 3).
|
Surgical features |
Number of cases |
|
Technical success rate |
25 (100%) |
|
Retrograde recanalization success rate |
24 (96%) |
|
Retrograde distal approach success rate |
23 (92%) |
|
Technical success considering conversion to antegrade intervention |
25 (100%) |
|
Local complications |
|
|
pulsatile hematoma |
1 (4%) |
|
arteriovenous fistula |
1 (4%) |
|
arterial occlusion |
1 (4%) |
Discussion
Step-by-step strategy is usually used for endovascular revascularization of the lower extremities. According to this approach, retrograde access and recanalization are applied only if antegrade technique is failed. We should say that retrograde techniques significantly increase technical success rate of surgery [3-5].
More rigid proximal cap of chronic occlusion compared to distal one was reported in researches of coronary arteries. Immediately before the occlusion and within its body, lateral branches can arise while some microchannels can be directed to small branches or vasa vasorum rather through the entire occlusion [6]. These morphological features of chronic occlusions, technical difficulties and major complications of transfemoral antegrade approach, successful experience of secondary retrograde interventions, benefits of transradial coronary interventions, as well as possible early activation of patients inspired the use of below-the-knee segment as a primary access. Moreover, close proximity of retrograde access point to arterial lesion can ensure support and control that will be at least comparable to those in antegrade approach.
It is difficult to say what place the primary retrograde distal approach will take in endovascular treatment of lower limb ischemia. We cannot determine whether this technique will be effective and safe only in “poor” candidates for femoral access or in any patient with “suitable” arterial lesion of the lower limb. We assume that this approach will be valuable in patients with severe intermittent claudication and ineffective therapy or indications for preventive intervention. In our opinion, this fact will be associated with patent below-the-knee arteries in most of these patients.
An extended occlusive lesion of below-the-knee arteries is common in patients with chronic limb threatening ischemia, and patent segment for approach may be short and/or stenotic [7]. Moreover, lesion of tibial arteries may be accompanied by damage to foot arteries that makes puncture extremely difficult or completely impossible [7-9]. Importantly, occlusion of all 3 tibial arteries is observed in multiple cases [7, 8]. This fact significantly complicates primary retrograde technique. Moreover, there is a high probability of recanalization of adjacent artery in patients with severe ulcerative necrotic lesions. In our sample, there were cases of recanalization of one tibial artery via another one. However, it is not always possible, and antegrade approach is more suitable for this procedure.
In addition, puncture of only a single patent artery may be possible in some cases, especially in patients with chronic limb threatening ischemia. Moreover, angiosomal artery may be the only patent or the most suitable for puncture. Therefore, puncture is associated with a certain risk for the limb in these patients. Access through a single patent artery was rare in our study (20%). At the same time, puncture of angiosomal artery was performed in 65% of patients with trophic defects. Angiosomal artery was the only patent in 15% of cases.
Angiosomal artery is often occluded within the lower leg and/or foot in patients with chronic limb threatening ischemia. Recanalization of this artery via another tibial artery to restore direct blood supply to the affected angiosome is not optimal option. Nevertheless, patency of angiosomal artery was restored in 3 out of 6 recanalizations of adjacent tibial arteries. It should be noted that the length of angiosomal artery occlusion did not exceed 5 cm in 2 cases (intraluminal recanalization). In 1 case, occlusion length was 8 cm (subintimal recanalization).
To date, there are few data on primary distal retrograde approach for revascularization of lower extremities. J. Mustafa reported primary distal approach in 27 patients. Chronic limb threatening ischemia was observed in 83% of cases. Technical success rate was 85.2% (n = 23), angiographic success rate — 95%. There were no major complications. However, false aneurysms within 30 days after revascularization occurred in 2 patients. In both cases, puncture of fibular artery was performed. Subsequently, coronary stent grafts were implanted [10]. J. Mustafa et al. performed puncture under ultrasound control in all cases, intervention per se — through a single distal approach. We used 2 approaches in 92% of cases: one for angiography (radial in most cases) and the second one (tibial arteries or dorsalis pedis artery) for recanalization and angioplasty.
A prospective multiple-center observational study devoted to efficacy and safety of retrograde distal approach in patients with infrainguinal occlusions was published in 2016. This approach was primary in 65 (33%) patients, i.e. without previous antegrade attempts. Technical success rate was 95.4%, recanalization success rate — 90.3%. No major complications of approach were registered [3].
In our study, access was technically successful in 100% of cases; retrograde recanalization was performed in 96% of cases. However, intervention in a retrograde manner with favorable angiographic result was completed in 92% of cases. All local complications (12%) were asymptomatic and diagnosed by angiography or ultrasound. We associate pulsatile hematoma and arteriovenous fistula arose from posterior tibial artery with the absence of a compression bandage after manual hemostasis. At first, we feared higher risk of arterial occlusion following a pressure bandage. However, the aforementioned cases of minor hemorrhagic complications contributed to revision of our approach. In one case, we had to place a stent-graft with 8 Fr delivery system through the distal retrograde access in a patient with bleeding from common femoral artery during femoropopliteal recanalization and subsequent unstable hemodynamics. This procedure resulted severe spasm of anterior tibial artery. Extraction of delivery system from anterior tibial artery was followed by intima detachment and subsequent occlusion of the artery. This complication was asymptomatic due to adequate collateral blood supply to dorsalis pedis artery through anterior perforator of fibular artery. Moreover, the last artery was hyperplastic, and plantar arteries arose from this vessel.
We should emphasize no local complications with systemic consequences in our study and foreign reports.
Conclusion
In a small group of patients with lower limb ischemia, endovascular interventions through primary retrograde distal approach are feasible (approach success rate 100%, recanalization success rate 96%, retrograde intervention success rate 92%) and safe regarding early postoperative complications. Conversion to antegrade intervention was required in 2 cases for successful revascularization (total angiographic success 100%). All complications of retrograde access were local.
The authors declare no conflicts of interest.