Awareness of anatomical variations for infrapopliteral intervention

Magnetically assisted soft milli-tools for occluded lumen morphology detection

Methodologies based on intravascular imaging have revolutionized the diagnosis and treatment of endovascular diseases. However, current methods are limited in detecting, i.e., visualizing and crossing, complicated occluded vessels. Therefore, we propose a miniature soft tool comprising a magnet-assisted active deformation segment (ADS) and a fluid drag-driven segment (FDS) to visualize and cross the occlusions with various morphologies. First, via soft-bodied deformation and interaction, the ADS could visualize the structure details of partial occlusions with features as small as 0.5 millimeters. Then, by leveraging the fluidic drag from the pulsatile flow, the FDS could automatically detect an entry point selectively from severe occlusions with complicated microchannels whose diameters are down to 0.2 millimeters. The functions have been validated in both biologically relevant phantoms and organs ex vivo. This soft tool could help enhance the efficacy of minimally invasive medicine for the diagnosis and treatment of occlusions in various circulatory systems.

Contemporary critical limb ischemia: Asian multidisciplinary consensus statement on the collaboration between endovascular therapy and wound care

The burden of peripheral artery disease (PAD) and diabetes in Asia is projected to increase. Asia also has the highest incidence and prevalence of end-stage renal disease (ESRD) in the world. Therefore, most Asian patients with PAD might have diabetic PAD or ESRD-related PAD. Given these pandemic conditions, critical limb ischemia (CLI) with diabetes or ESRD, the most advanced and challenging subset of PAD, is an emerging public health issue in Asian countries. Given that diabetic and ESRD-related CLI have complex pathophysiology that involve arterial insufficiency, bacterial infection, neuropathy, and foot deformity, a coordinated approach that involves endovascular therapy and wound care is vital. Recently, there is increasing interaction among cardiologists, vascular surgeons, radiologists, orthopedic surgeons, and plastic surgeons beyond specialty and country boundaries in Asia. This article is intended to share practical Asian multidisciplinary consensus statement on the collaboration between endovascular therapy and wound care for CLI.

Evaluation of popliteal artery branching patterns and a new subclassification of the 'usual' branching pattern

PURPOSE

To determine the frequency of popliteal artery branching variations in a wide study cohort and to investigate the relationship between these variations and infrapopliteal peripheral arterial disease (PAD). A subclassification was proposed for the most encountered type I-A, utilizing tibio-fibular trunk (TFT) length.

METHODS

A total number of 1184 lower extremity digital subtraction angiography (DSA) studies of 669 patients were evaluated. Following exclusion, 863 lower extremity DSA studies (431 right, 432 left) of 545 patients were enrolled. Popliteal artery branching type, patency of anterior tibial artery (ATA), fibular artery (FA) and posterior tibial artery (PTA) in each extremity and TFT length for type I-A extremities were recorded. Percentages of branching patterns, mean length and cut-off value of TFT and incidence of PAD in different types of branching were calculated.

RESULTS

Type I-A was the most common type of branching (81.3%). Frequency of branching pattern variation was 18.7%, the most common variation category was category III (12.2%) and the most common variation type was type III-A (5.6%). ATA and PTA had higher percentages of PAD in extremities with variant branching types. Cut-off value of 3 cm for TFT length was proposed in order to subclassify type I-A.

CONCLUSIONS

Our study cohort presents a higher incidence of popliteal artery branching variations. Some branching variations might have effect on the involvement pattern of the infrapopliteal arteries by PAD. We propose a subclassification for type I-A; type I-A-S (TFT < 3 cm) and type I-A-L (TFT ≥ 3 cm) which might have impact on interventional procedures.

Variants of the popliteal artery terminal branches as detected by multidetector ct angiography

Objective

To evaluate variants of the popliteal artery (PA) terminal branches with 64-multidetector computed tomographic angiography (64-MD CTA).

Materials and Methods

A total of 495 extremities (251 right, 244 left) of 253 patients undergoing a 64-MD CTA examination were included in the study. Of these, 242 extremities were evaluated bilaterally, whereas 11 were evaluated unilaterally. The terminal branching pattern of the PA was classified according to the classification scheme proposed by Kim; the distance between the medial tibial plateau and the origin of the anterior tibial artery (A) and the length of the tibioperoneal trunk (B) have been measured and recorded.

Results

In 459 cases (92.7%) branching of PA occurred distal to the knee joint (Type I); in 18 cases (2.8%) PA branching was superior to the knee joint (Type II); and hypoplasia of the PA branches was found in 27 cases (5.5%) (Type III). Among these types the most frequent branching patterns were Type IA (87.5%), Type IIIA (3.9%), and Type IB (3.8%). The ranges of A and B mean distances were 47.6 mm and 29.6 mm, respectively

Conclusion

Variations in popliteal artery terminal branching pattern occurred in 7.4% to 17.6% of patients. Pre-surgical detection of these variations with MD CTA may help to reduce the risk of iatrogenic arterial injury by enabling a better surgical treatment plan.

Effect of single tibial artery revascularization on microcirculation in the setting of critical limb ischemia

BACKGROUND

Benefits of 2-dimensional (2D) angiosome-oriented infrapopliteal revascularization remain controversial. The aim of this retrospective study was to clarify the effect of single tibial artery revascularization on the dorsal and plantar microcirculation of critically ischemic limbs based on skin perfusion pressure (SPP).

METHODS AND RESULTS

Fifty-seven interventions that only involved either anterior tibial artery (ATA) or posterior tibial artery (PTA) revascularization were included in this study. SPP was measured on the dorsal side (theoretically ATA perfusion area) and the plantar side (theoretically PTA perfusion area) before and after the procedure. Dorsal and plantar SPP increased significantly, from 33 (IQR 23-40.5) to 52 (IQR 32.5-65) mm Hg (P<0.0001) and 31.6±16.1 to 44.8±19.2 mm Hg (P=0.001) after ATA revascularization, respectively, and from 29.3±14.0 to 42.4±19.7 mm Hg (P=0.003) and 29.3±9.8 to 43.5±15.9 mm Hg (P<0.001) after PTA revascularization, respectively. Both ATA and PTA revascularization were not associated with any significant differences in ΔSPP between the dorsal and the plantar regions of the foot. Only 64% and 58% of ATA revascularization cases showed higher post-SPP and ΔSPP on the dorsal side than on the plantar side, respectively. Also, only 47% and 40% of PTA revascularization cases showed higher post-SPP and ΔSPP on the plantar side than on the dorsal side, respectively.

CONCLUSIONS

Single tibial artery revascularization, whether of the ATA or PTA, yielded comparable improvements in microcirculation of the dorsal and plantar foot. Approximately half of the feet revascularized had a change in microcirculation that was not consistent with the 2D angiosome theory.

Stent-assisted below-the-ankle angioplasty for limb salvage

PURPOSE

To report the clinical outcome of stent-assisted below-the-ankle angioplasty for limb salvage in the setting of critical limb ischemia (CLI).

METHODS

A retrospective single-center study was conducted of 40 critical ischemic limbs in 31 patients (mean age 67 ± 8 years, range 46-94) undergoing below-the-ankle stent-assisted angioplasty between April 2006 and April 2009. Coronary bare metal stents were implanted in cases of failed balloon angioplasty due to significant recoil, flow-limiting dissection, abrupt closure, or repeat early reocclusion.

RESULTS

Technical success was 93% (37 limbs), with 3 failures to cross the occlusive lesions. Acute or subacute occlusion was evident in 9 (23%) limbs. The number of runoff vessels increased significantly (p < 0.001) from 0.6 ± 0.8 to 1.8 ± 0.8. During a clinical follow-up of 19.3 ± 11.4 months (range 1-48), the number of repeat interventions for limb salvage was 2.2 ± 1.6 (range 1-9), and a total of 1.6 ± 0.9 stents (range 1-3) were implanted in 8 dorsalis pedis arteries. Acute or subacute stent thrombosis after stenting was observed in 2 of these, and symptomatic in-stent restenosis was detected in 4, which were all treated by repeat intervention. At 6, 12, and 24 months, the freedom from repeat intervention was 39.6%, 39.6%, and 35.2%, respectively. Amputation-free survival was 80.0%, 69.7%, and 62.7%, and limb salvage was 94.7%, 91.4%, and 82.1% at the same time points. Patient survival rates were 77.4%, 71.0%, and 71.0%, respectively. During a mean follow-up of 13.4 ± 12.7 months (range 1-31 months) in 7 of the 8 stented arteries, all examined stents were deformed: stent compression was evident in 5 and stent fracture in 5. However, 7 limbs undergoing dorsalis pedis artery stenting showed complete wound healing; 1 limb had a resistant wound in the heel.

CONCLUSION

Stent-assisted below-the-ankle angioplasty produced a satisfactory clinical outcome but with the need for repeat intervention. Thus, further refinement in endovascular technology is mandatory to reduce the need for repeat interventions and to resolve stent deformity issues.