R/PTAS is a suitable, less invasive alternative to ABF for the treatment of severe AIOD. Repair of the concomitant femoral occlusive disease is often needed regardless of open or endovascular treatment. Infrainguinal disease negatively affects the durability of the procedure and patient survival.

Brachial artery access is necessary for complex endovascular procedures and can be achieved in most patients safely. Postprocedural vigilance is warranted because most patients with complications will require operative correction.

Purpose: To compare angiograms, considered the gold standard for diagnostic imaging of peripheral arterial disease (PAD), to the corresponding histological sections of popliteal and tibial vessels obtained after amputation to determine if angiography fails to define atheroma burden in “normal appearing” arteries in patients with PAD. Methods: Between 2004 and 2006, 69 patients underwent amputation of a lower extremity for severe tissue loss, gangrene, or pedal sepsis precluding limb salvage. Popliteal and tibial vessels were harvested, perfusion-fixed, and analyzed histologically. Thirty-four of these patients had pre-amputation angiography during attempted salvage procedures. Angiograms with patent or minimally diseased vessel segments (n=19) were assessed for stenoses, diameter, and calcification by 3 vascular surgeons (n=72 evaluations). These results were compared to corresponding cross-sectional histological slides (n=66) in a blinded manner. Results: Angiograms performed prior to above-knee (n=9) or below-knee (n=10) amputation revealed 24 stenoses with a mean (±SD) diameter-reducing stenosis of 19.5%±15.2%. Corresponding histological cross sections revealed greater linear stenoses measured via boundaries of the internal elastic lamina (IEL stenosis, 28.9%±20.2%, p=0.003 versus angiography) or via boundaries of the external elastic membrane (vessel stenosis, 43.1%±15.2%, p<0.0001). Stenosis calculated by area methods (IEL area) were greater and measured 39.2%±24.2% (p<0.0001) and 60.9%±15.2% (vessel area, p<0.0001). Popliteal arteries had greater discrepancy in stenosis measurement than tibial arteries (18.5%±14.6% versus 34.9%±21.0%, p=0.0005). However, evaluations of tibial arteries for concentricity of plaque (44% versus 69%, p=0.08) and calcification grade (1.6 versus 2.2, p=0.002) by angiography were discordant with histological analyses. Measurement of arterial diameter by histology for popliteal arteries (6.2±0.9 mm) and tibial arteries (3.1±0.7 mm) was greater than angiographic diameter determination (p<0.001). Conclusion: Angiography provides information on luminal characteristics of peripheral arteries but severely underestimates the extent of atherosclerosis in patients with PAD even in “normal appearing” vessels.

Objective-The aim of this study was to determine if significant differences in plaque composition exist between the popliteal and tibial vessels in patients with severe peripheral arterial disease (PAD).Methods-Forty-four patients with PAD required either above knee (n=38), below knee (n=5) or through knee (n=1) amputation for pedal sepsis/gangrene. The fifty-one vessels (anterior tibial, n=9; posterior tibial, n=10; peroneal, n=3; popliteal, n=29) were obtained, and underwent intravascular ultrasound (IVUS) evaluation ex vivo within 24 hours of amputation. Sequential IVUS data were obtained at known intervals throughout the vessel length, and then analyzed with radiofrequency techniques for quantification of plaque composition, plaque volume, and total vessel volume. Plaque composition was categorized as fibrous, fibro-fatty, necrotic core, and dense calcium. Clinical data was obtained via review of electronic records at the time of amputation. Two-sided t-tests were performed to compare components within each plaque. Results are expressed as mean percentage ±SEM.Results-Tibial vessels had more dense calcium within these plaques than popliteal arteries (33.8 ±5.6% v. 10.6±1.9%, P<0.001).Consequently, distal vessels had less fibro-fatty and fibrous plaque than popliteal arteries (7.7±1.4% v. 13.1±1.2%, P<0.005; 42.4±4.7% v. 61.4±2.2%, P<0.001), respectively. Necrotic core plaque composition was found to be similar when comparing tibial verses popliteal arteries (16.1% vs. 14.9%, p = NS). Clinical factors including diabetes, hyperlipidemia and chronic renal insufficiency were not associated with plaque composition differences using a univariate analysis.Conclusions-As we progress distally in the arterial tree of patients with PAD, calcium plaque content increases with decreasing burden of fibro-fatty plaque. Clinical and demographic factors with the exception of smoking were not found to be associated with atherosclerotic plaque composition.

Endothelial cells exposed to thrombin have increased arginase I messenger RNA and protein levels. Arterial thrombosis causes endothelial dysfunction without affecting smooth muscle responsiveness. Arginase blockade can lead to normalization of arterial vasomotor function.