Long-Term Outcomes of Vein Adjuncts in Distal Infrainguinal Bypass.

BACKGROUND: Autologous vein is recommended for infrainguinal bypass due to improved freedom from occlusion compared to prosthetic graft. In patients without adequate vein, a vein adjunct at the distal anastomosis has been suggested to improve patency in small studies. This study aimed to determine if performance of a distal vein adjunct was associated with improved freedom from occlusion in below-knee popliteal and tibial bypasses compared to prosthetic bypass alone. METHODS: A retrospective review of the Vascular Quality Initiative Infrainguinal Bypass database was conducted. Patients undergoing prosthetic-only and prosthetic with vein adjuncts were compared. Inclusion criteria included age ≥18 years, and bypass to below-knee popliteal or tibial vessels. Exclusion criteria included autologous vein conduits and prior interventions. Groups were further divided into below-knee popliteal and tibial subgroups. RESULTS: A cohort of 3,939 patients underwent bypass to the below-knee popliteal artery, with 287 (7.3%) receiving vein adjuncts. More patients were male (68.8 vs. 57.8%, P < 0.001) and had higher rates of congestive heart failure (21.1 vs. 16.0%, P = 0.040) within the below-knee popliteal group. Two-year bypass occlusion was decreased in patients receiving vein adjuncts (11.6 vs. 17.1%, P = 0.004). A cohort of 2,378 patients underwent tibial bypass, with 473 (19.9%) receiving vein adjuncts. Within the tibial group, patients were similar in age, body mass index, race, comorbidities, and indications. Bypass occlusion (24.8 vs. 17.6%, P = 0.005) and amputation (20.5 vs. 15.9%, P = 0.048) rates at 2 years were worse for patients who did not receive a distal vein adjunct to tibial arteries. CONCLUSIONS: Distal vein adjuncts are associated with improved freedom from occlusion, amputation, major adverse limb events, and overall survival when compared to bypasses performed with prosthetic graft alone for tibial bypasses within the Vascular Quality Initiative. A vein adjunct was not associated with improved freedom from occlusion in below-knee popliteal bypasses. Consideration should be given to utilization of a distal vein adjunct to improve prosthetic bypass longevity and limb salvage for patients requiring tibial bypasses.

Ultrasound detection of non-atherosclerotic intima-medial abnormalities of lower limbs arteries in amateur endurance runners.

BACKGROUND: Structural changes in the lower limb's arterial wall in amateur endurance runners are a rare incidental finding, represented just by several case reports. AIM: Study the incidence of non-atherosclerotic lower limb artery wall changes in defined group of amateur endurance runners and identify relationship with the training parameters and the relevant biochemical markers. METHODS: Amateur male athletes engaged in endurance running for more than 5 years were enrolled. Tibial and anterior popliteal arteries on each side were examined by ultrasound with focus on non-atherosclerotic structural wall changes: intima-medial border blurring, presence and character of non-atherosclerotic noduli. Subsequently the descriptive and correlation analysis were performed. RESULTS: The study enrolled 20 amateur male endurance runners from Black Swan Triathlon Club Slovakia. The low atherosclerotic risk was represented by normal lipid levels, BMI under 30 kg/m2 and non-smokers in all participants. At least one type of structural artery wall abnormality (noduli or intima-medial border blurring) was present in 19 of 20 participants (95%). The most present was the intima-medial blurring. (80% of participants). The noduli were present in 65% of study group, in almost 40% of these, they were considered as hyperechogenic. All these affections were predominantly in popliteal artery area (65%). The vast majority has bilateral affection. We find a mild correlation between these ultrasound findings and training load represented by annual kilometers and run hours. There was no association between these changes and lipid spectrum or CRP level. CONCLUSION: The subclinical lower limb artery changes, represented by intima-medial border blurring and non-atherosclerotic noduli were present in almost every amateur endurance runner. Despite the underlying mechanism is not understood, the increased training load seems to be one of the responsible factors.

Haemodynamic effect of a leg compression bandage on the distal posterior tibial artery using 4D flow magnetic resonance imaging: A quantitative study.

The uncertainty concerning the physiological effects of compression bandaging on the peripheral blood flow is a challenge for healthcare professionals. The main objective was to determine the haemodynamic impact on the distal posterior tibial artery after the application of a high-compression leg multicomponent bandaging system using 4D flow magnetic resonance imaging. Leg dominance disparities of the posterior tibial artery before and after the application of the compressive bandage were also analysed. Twenty-eight healthy female volunteers were recruited (mean: 25.71, standard deviation: 4.74 years old) through a non-probability convenience sampling. The 4D flow magnetic resonance imaging of the distal tibial posterior artery was performed in all participants, first under standard resting conditions and after the application of a compression bandage in the leg. When the strong compressive bandage was applied, the area of the assessed artery decreased by 14.2%, whilst the average speed increased by 19.6% and the flow rate increased by 184.8%. There were differences between the haemodynamic parameters of both legs according to dominance, being statistically significantly lower in the dominant leg. The application of strong compressive bandaging significantly increases the arterial flow and mean velocity in the distal segment of the posterior tibial artery, in healthy volunteers by 4D flow magnetic resonance imaging. In this study, leg dominance influenced some of the haemodynamic parameters. According to the results, leg compression bandages cannot be contraindicated in vascular ulcers with arterial compromise.

Effect of cranial tibial artery laceration on radiographic bone healing and perioperative complications in dogs undergoing tibial plateau leveling osteotomy.

During tibial plateau leveling osteotomy (TPLO), the laceration of the cranial tibial artery (LCTA) may occur, and the ligation of the cranial tibial artery might lead to impaired blood supply to the osteotomy site. The present case-control study aimed to evaluate the effect of LCTA on TPLO healing and the occurrence of perioperative complications. The incidence and predisposing factors to LCTA were also investigated. Fourteen cases experiencing LCTA were retrospectively enrolled from medical records of two veterinary teaching hospitals (LCTA group), whereas 28 randomly selected TPLOs that did not experience LCTA were included in the control group. Signalment data, proximal tibial epiphysis conformation, osteotomy features, perioperative complications, and bone healing were compared between the two groups. Bone healing was evaluated using the modified radiographic union scale for tibial fracture and the visual analog scale. The mean incidence was 9.6%. Bodyweight was significantly higher in the LCTA group compared to the control group (P = 0.009). Dogs belonging to the LCTA groups were significantly younger (P = 0.01). Intraoperative hypotension was significantly overreported in the LCTA group (P = 0.0001). None of the other variables differed significantly between the two groups. Dogs' size seems to be a predisposing factor, with dogs weighing >15 kg having 22 times more chance of experiencing LCTA. Due to the well-developed collateral blood supply of the canine hindlimb, LCTA and the closure of the cranial tibial artery did not appear to delay the radiographic bone healing or affect the incidence of perioperative complications.

Supra-Inguinal Inflow for Distal Bypasses Have Acceptable Patency and Limb Salvage Rates.

BACKGROUND: There is a paucity of data evaluating outcomes of lower extremity bypass (LEB) using supra-inguinal inflow for revascularization of infra-inguinal vessels. The purpose of this study is to report outcomes after LEB originating from aortoiliac arteries to infra-femoral targets. METHODS: The Vascular Quality Initiative database (2003-2020) was queried for patients undergoing LEB from the aortoiliac arteries to the popliteal and tibial arteries. Patients were stratified into 3 cohorts based on outflow targets (above-knee [AK] popliteal, below-knee [BK] popliteal, and tibial arteries). Perioperative and 1-year outcomes including primary patency, amputation-free survival (AFS), and major adverse limb events (MALEs) were compared. A Cox proportional hazards model was used to estimate the independent prognostic factors of outcomes. RESULTS: Of 403 LEBs, 389 (96.5%) originated from the external iliac artery, while the remaining used the aorta or common iliac artery as inflow. In terms of the distal target, the AK popliteal was used in 116 (28.8%), the BK popliteal in 151 (27.5%), and tibial vessels in 136 (43.7%) cases. BK popliteal and tibial bypasses, compared to AK popliteal bypasses, were more commonly performed in patients with chronic limb-threatening ischemia (69.5% and 69.9% vs. 48.3%; P < 0.001). Vein conduit was more often used for tibial bypass than for AK and BK popliteal bypasses (46.3% vs. 21.9% and 16.3%; P < 0.001). In the perioperative period, BK popliteal and tibial bypass patients had higher reoperation rates (16.9% and 13.2% vs. 5.2%; P = 0.02) and lower primary patency (89.4% and 89% vs. 95.7%; P = 0.04) than AK bypass patients. At 1 year, compared with AK popliteal bypasses, BK and tibial bypasses demonstrated lower primary patency (81.9% vs. 56.7% vs. 52.4%, P < 0.001) and freedom from MALE (77.6% vs. 70.2% vs. 63.1%, P = 0.04), although AFS was not significantly different (89.7% vs. 90.6% vs. 83.8%, P = 0.19).On multivariable analysis, compared with AK popliteal bypasses, tibial bypasses were independently associated with increased loss of primary patency (hazard ratio 1.9, 95% confidence interval, 1.03-3.51, P = 0.04). Subanalysis of patients with chronic limb-threatening ischemia demonstrated significantly higher primary patency in the AK popliteal cohort at discharge and 1 year, but no difference in AFS or freedom from MALE between the cohorts at follow-up. CONCLUSIONS: LEB with supra-inguinal inflow appear to have acceptable rates of 1-year patency and limb salvage in patients at high risk of bypass failure. Tibial outflow target was independently associated with worse primary patency but not with MALE or AFS.

Influence of a Novel Morphology-Driven Classification on Limb Salvage after Isolated Tibial Intervention for Chronic Limb Threatening Ischemia.

BACKGROUND: Infra-popliteal interventions for chronic limb-threatening ischemia (CLTI) can be impacted by the morphology of the tibial vessels. The aim of this study was to examine the impact of a novel morphology-driven classification on the outcomes of isolated tibial intervention for CLTI. METHODS: A database of patients undergoing isolated tibial interventions for CLTI at a single center between 2010 and 2020 was retrospectively queried. Patients with isolated infra-popliteal disease were identified, and their anatomy was scored as present or absent for lesion calcification (1 point), target vessel diameter<3.0 mm (1 point), lesion length>300 mm (1 point), and poor pedal runoff score (1 point). Patients were then divided into 3 groups: low risk (0 or 1 points), moderate risk (2 points), and high risk (3 or 4 points). Intention to treat analysis by the patient was performed. Limb-based patency (the absence of reintervention, occlusion, critical stenosis [>70%], or hemodynamic compromise with ongoing symptoms of CLTI as it related to the patency of the preoperatively determined target artery pathway) was assessed. Patient-oriented outcomes of amputation-free survival (AFS; survival without major amputation) and freedom from major adverse limb events (MALE; above ankle amputation of the index limb or major reintervention: new bypass graft, jump/interposition graft revision) were evaluated. RESULTS: 1,607 patients (55% male, average age 60 years, 3,846 vessels) underwent tibial intervention for CLTI. The majority of the patients were diabetic and of Hispanic origin. Morphologically, 27%, 31%, and 42% of the vessels were categorized as low risk, moderate risk, and high risk, respectively. There was a significant worsening of the infra-popliteal Global Limb Anatomic Staging System (GLASS) grading as the morphological risk increased. The 30-day major adverse cardiac events (MACE) were equivalent across the groups and were under the stated objective performance goal (OPG) of ≤10%. In contrast, both the 30-day MALE and the 30-day major amputations were significantly different across the groups, with the low-risk group remaining under the OPG of ≤9% and ≤4%, respectively, while the moderate risk and high risk exceeded the goal threshold. For the OPG, freedom from MALE was 60 ± 5%, 46 ± 5%, and 22 ± 9% at 5 years for low-, moderate-, and high-risk groups, respectively (mean ± standard error of the mean; P = 0.008). Overall AFS was 55 ± 5%, 37 ± 6%, and 18 ± 7% at 5 years for low-, moderate-, and high-risk groups, respectively (mean ± standard error of the mean; P = 0.003). CONCLUSIONS: Tibial anatomic morphology impacts isolated tibial endovascular intervention with adverse morphology associated with poorer short- and long-term outcomes. Risk stratification based on anatomic predictors should be an additional consideration as one intervenes on infra-popliteal vessels for CLTI.

Effect of EDTA with porous balloon on calcified lesion: An atherosclerotic cadaver study.

BACKGROUND: Ethylene diamine tetra-acetic acid (EDTA) is a chelating agent used to dissolve calcium deposits but evidence in decalcifying atherosclerotic lesions is limited. AIMS: We assessed the feasibility and efficacy of EDTA delivered via porous balloon to target calcified lesions in cadaveric below-the-knee (BTK) arteries. METHODS: Using porcine carotid arteries, EDTA concentration was measured in the arterial wall and outside the artery at the 0-, 0.5-, 4-, and 24-h circulation after the injection through a porous balloon. In cadaver BTK samples, the proximal and distal anterior tibial artery (ATA) and distal posterior tibial artery (PTA) were studied. EDTA-2Na/H2O or EDTA-3Na/H2O were administrated using a porous balloon, then circulated for 6 h for EDTA-3Na/H2O and 24 h for EDTA-2Na/H2O and EDTA-3Na/H2O. Micro-CT imaging of the artery segments before and after the circulation and cross-sectional analyses were performed to evaluate calcium burden. RESULTS: In the porcine carotid study, EDTA was delivered through a porous balloon present in the arterial wall and was retained there for 24 h. In BTK arteries, cross-sectional analyses of micro-CT revealed a significant decrease in the calcium area in the distal ATA segment under 24-h circulation with EDTA-2Na/H2O and in the distal ATA segment under 24-h circulation with EDTA-3Na/H2O. The proximal ATA segment under 6-h circulation with EDTA-3Na/H2O showed no significant change in any parameters of calcium CONCLUSION: EDTA-3Na/H2O or EDTA-2Na/H2O with longer circulation times resulted in greater calcium reduction in atherosclerotic lesion. EDTA may have a potential therapeutic option for the treatment of atherosclerotic calcified lesions.

Retrograde Tibio-Pedal Access for Endovascular Interventions for Treating Peripheral Arterial Disease.

Retrograde tibio-pedal access represents a feasible method for endovascular revascularization when antegrade methods fail. The article offers an extensive review of retrograde tibio-pedal access, emphasizing the technique and documented outcomes.

Artificial intelligence of arterial Doppler waveforms to predict major adverse outcomes among patients with diabetes mellitus.

OBJECTIVE: Patients with diabetes mellitus (DM) are at increased risk for peripheral artery disease (PAD) and its complications. Arterial calcification and non-compressibility may limit test interpretation in this population. Developing tools capable of identifying PAD and predicting major adverse cardiac event (MACE) and limb event (MALE) outcomes among patients with DM would be clinically useful. Deep neural network analysis of resting Doppler arterial waveforms was used to detect PAD among patients with DM and to identify those at greatest risk for major adverse outcome events. METHODS: Consecutive patients with DM undergoing lower limb arterial testing (April 1, 2015-December 30, 2020) were randomly allocated to training, validation, and testing subsets (60%, 20%, and 20%). Deep neural networks were trained on resting posterior tibial arterial Doppler waveforms to predict all-cause mortality, MACE, and MALE at 5 years using quartiles based on the distribution of the prediction score. RESULTS: Among 11,384 total patients, 4211 patients with DM met study criteria (mean age, 68.6 ± 11.9 years; 32.0% female). After allocating the training and validation subsets, the final test subset included 856 patients. During follow-up, there were 262 deaths, 319 MACE, and 99 MALE. Patients in the upper quartile of prediction based on deep neural network analysis of the posterior tibial artery waveform provided independent prediction of death (hazard ratio [HR], 3.58; 95% confidence interval [CI], 2.31-5.56), MACE (HR, 2.06; 95% CI, 1.49-2.91), and MALE (HR, 13.50; 95% CI, 5.83-31.27). CONCLUSIONS: An artificial intelligence enabled analysis of a resting Doppler arterial waveform permits identification of major adverse outcomes including all-cause mortality, MACE, and MALE among patients with DM.

Vascular Reconstruction and Limb Loss in Military Tibial Artery Injuries.

BACKGROUND: Selective operative management of injuries to the tibial arteries is controversial, with the necessity of revascularization in the face of multiple tibial arteries debated. Tibial artery injuries are frequently encountered in military trauma, but revascularization practices and outcomes are poorly defined. We aimed to investigate associations between the number of injured vessels and reconstruction and limb loss rates in military casualties with tibial arterial trauma. METHODS: A US military database of lower extremity vascular injuries from Iraq and Afghanistan (2004-2012) was queried for limbs sustaining at least 1 tibial artery injury. Injury, intervention characteristics, and limb outcomes were analyzed by the number of tibial arteries injured (1, T1; 2, T2; 3, T3). RESULTS: Two hundred twenty one limbs were included (194 T1, 22 T2, 5 T3). The proportions with concomitant venous, orthopedic, nerve, or proximal arterial injuries were similar between groups. Arterial reconstruction (versus ligation) was performed in 29% of T1, 63% of T2, and universally in T3 limbs (P < 0.001). Arterial reconstruction was via vein graft (versus localized repair) in 62% of T1, 54% of T2, and 80% of T3 (P = 0.59). T3 received greater blood transfusion volume (P = 0.02), and fasciotomy was used universally (versus 34% T1 and 14% T2, P = 0.05). Amputation rates were 23% for T1, 26% for T2, and 60% for T3 (P = 0.16), and amputation was not significantly predicted by arterial ligation in T1 (P = 0.08) or T2 (P = 0.34) limbs. Limb infection was more common in T3 (80%) than in T1 (25%) or T2 (32%, P = 0.02), but other limb complication rates were similar. CONCLUSIONS: In this series of military lower extremity injuries, an increasing number of tibial arteries injured was associated with the increasing use of arterial reconstruction. Limbs with all 3 tibial arteries injured had high rates of complex vascular reconstruction and eventual amputation. Limb loss was not predicted by arterial ligation in 1-vessel and 2-vessel injuries, suggesting that selective reconstruction in these cases is advisable.

Anterior Tibial Artery Danger Zone During Anterolateral Plate Fixation of the Distal Tibia: A 3D Computed Tomography Angiogram Modeling Study.

OBJECTIVES: The objective of this study was to define the danger zone at which the anterior tibial artery (ATA) is at risk during anterolateral plating of the distal tibia using a novel 3D computed tomography angiography (CTA) modeling technique. METHODS: 116 patients (232 lower extremities) who underwent lower extremity CTAs between April 2020 and April 2022 were identified. Those with lower extremity trauma, evidence of a previously healed tibial fracture, or poor visualization of the ATA were excluded. The remaining 150 lower extremities (92 patients) were modeled with an anterolateral distal tibia plate using Sectra IDS7 software. The distance of the ATA from bony landmarks was measured perpendicular to the level at which the vessel intersected the plate. RESULTS: The ATA intersected the plate proximally at a mean distance of 10.5 cm (95% confidence intervals, 10.2-10.9) and at a mean distance of 4.6 cm (95% confidence intervals, 4.4-4.9) distally from the central tibial plafond. The ATA intersected with the plate as far distal as hole number 1 and as proximal as hole 14 of the plate. The greatest injury risk was associated with plate holes 3-8. In this region, the artery was at risk in 46-99 percent of specimens. CONCLUSIONS: The ATA is at risk when screws are placed percutaneously in an anterolateral distal tibia plate. The artery can be as close as 4.4 cm and as far as 10.9 cm proximal to the tibial plafond when crossing the plate, correlating to a risk of injury to the ATA at plate holes 1 through 14.

Circumferential degree of tibial artery calcification is associated with infrapopliteal endovascular revascularization outcomes in patients with chronic limb-threatening ischemia.

BACKGROUND: Tibial artery calcification (TAC) is correlated with an increased risk of amputation and mortality in patients with chronic limb-threatening ischemia (CLTI). The association between calcification characteristics and adverse limb events of CLTI. However, it has not been assessed. This study aims to assess the relationship between the characteristics of TAC based on computed tomography angiography (CTA) scans and postoperative outcomes in patients with CLTI undergoing infrapopliteal endovascular therapy. METHODS: This was a retrospective study of patients who underwent infrapopliteal endovascular revascularization for CLTI and had a preoperative CTA scan. Based on CTA, TAC was divided into the following categories: annularity, thickness, continuity and severity. Cox regression models using generalized estimating equations were performed to assess the relationship between calcification characteristics and postoperative outcomes. The outcomes evaluated were the occurrence of all cause mortality (ACM) and unplanned amputation. RESULTS: Among the 148 patients undergoing endovascular, there were 50 (33.8%) patients died and 26 (17.6%) patients underwent unplanned amputation. Annular calcification was more common in the ACM group than in the non-ACM group. No significant differences were found between the two groups with regard to the probability of calcification in the thickness and the continuity (P>0.05). Patients in the unplanned amputation group had significantly annular, thin and continuity calcifications (P<0.05) than those in the non-unplanned amputation group. The presence of annular calcification was an independent predictor of ACM (hazard ratio (HR), 3.186; 95% confidence interval (CI), 1.781-5.702; P<0.001) and unplanned amputation (HR, 3.739; 95% CI, 1.707-8.191; P<0.05). CONCLUSIONS: Among patients with CLTI, the occurrence of annular calcification in the tibial artery are related to a greater chance of ACM and unplanned amputation in the postoperative period. The circumferential degree of TAC of the operated limb can be considered as a marker of clinical prognosis in this group of patients.

Ultrasound-detected tibial artery calcification as a marker of cardiovascular and lower-limb risk in asymptomatic patients with type-2 diabetes.

BACKGROUND: Medial arterial calcification (MAC) is a vascular disease distinct from atherosclerosis. Recently, several studies have demonstrated that MAC is an important marker of cardiovascular events. We aim to assess the presence of MAC during ultrasound screening of lower-limb vasculature and its association with both cardiovascular (CV) and lower-limb events in patients with type-2 diabetes. METHODS: A retrospective cohort study was conducted on 1119 patients with type-2 diabetes free from CV disease. A CV work-up, including vascular ultrasound, was performed for each patient. The presence of MAC was assessed on posterior tibial arteries and ankle-brachial index (ABI) was measured. Major acute CV events (MACEs) and lower-limb events (MALEs) were recorded as a composite endpoint for a 5-year period. RESULTS: We identified MAC among 212 (18.9%) patients. The independent determinants of MAC were age and diabetic retinopathy. Over a period of 5 years, 125 MACEs and 22 MALEs occurred. MAC was significantly associated with the composite outcome MACE + MALE (HR = 1.94; 95% CI: 1.23, 3.08, p = 0.005) or with MACE (HR = 1.85; 95% CI: 1.16, 2.95, p = 0.010). Adjusted for ABI and diabetic foot wound, MAC remained a determinant of MALE (HR = 5.49; 95% CI: 2.19, 13.76, p < 0.001). Considering each ABI group, MAC was associated with both MACE and MALE in the normal ABI group. CONCLUSIONS: Ultrasound-detected MAC on tibial arteries seems to be a determinant of both CV and lower-limb events, independent from ABI. MAC helps to refine the CV risk in patients with normal ABI.

Comparison of radial, dorsalis pedis, and posterior tibial arteries for ultrasound-guided arterial catheterisation with dynamic needle tip positioning in paediatric patients: a randomised controlled trial.

BACKGROUND: Arterial catheterisation in children can be challenging and time-consuming. We aimed to compare the success rates of ultrasound-guided arterial catheterisation utilising the short-axis out-of-plane approach with dynamic needle tip positioning in the radial, dorsalis pedis, and posterior tibial arteries in paediatric patients. We also examined the factors influencing the catheterisation success using dynamic needle tip positioning. METHODS: Paediatric patients (aged <3 yr) undergoing cardiac surgery were randomly assigned to three groups based on puncture sites: radial artery (Group R), dorsalis pedis artery (Group D), and posterior tibial artery (Group P). The first-attempt and overall success rates of arterial catheterisation were compared, followed by multiple logistic regression analysis (dependent variable: first-attempt success; independent variables: body weight, diameter and depth of the artery, targeted artery, and trisomy 21). RESULTS: The study included 270 subjects (n=90 per group). There was no significant difference in the first-attempt (Group R: 82%, Group D: 76%, and Group P: 81%) and overall success rates (Group R: 94%, Group D: 93%, and Group P: 91%) among the three groups. The diameter of the artery (per 0.1 mm) (odds ratio: 1.32, 95% confidence interval: 1.09-1.60) and trisomy 21 (odds ratio: 0.43, 95% confidence interval: 0.20-0.92) were independent predictors of first-attempt success or failure. CONCLUSION: The first-attempt and overall success rates of arterial catheterisation of the dorsalis pedis and posterior tibial arteries were not inferior to those in the radial artery when using dynamic needle tip positioning. These two lower extremity peripheral arteries present viable alternative catheterisation sites in paediatric patients. CLINICAL TRIAL REGISTRATION: UMIN000042847.

Contrast administration via ultrasound-guided injection of the cranial tibial artery results in contrast enhancement of the soft tissues of the metatarsus in horses undergoing CT.

Delivery of mesenchymal stem cells (MSC) via intravascular techniques to treat diffuse and/or inaccessible soft tissue injuries has grown in popularity. The purpose of the current prospective, analytical pilot study was to utilize CT to validate this novel technique and provide additional evidence to support its use for injectate delivery to specific soft tissue structures. Of particular interest was the proximal suspensory ligament, which presents a challenging injection target. Six adult horses without lameness underwent CT of the distal hindlimbs. Scans were obtained prior to ultrasound-guided catheterization of the cranial tibial artery, in addition to early and delayed scans acquired following intra-arterial contrast administration. Region of interest analysis of the superficial and deep digital flexor tendons and suspensory ligament was used to assess contrast enhancement within these structures. Linear mixed models were used to determine statistical significance. Significant (P < 0.05) mean contrast enhancement was seen in all postinjection time points in all soft tissue structures of interest. This indicates that ultrasound-guided injection of the cranial tibial artery results in perfusion of injectate throughout the distal hind limb, including the major soft tissue structures of the metatarsus. This provides further support for this technique as a method of MSC delivery to multifocal or inaccessible injury of these structures, including the proximal suspensory ligament.

Anatomical study of the distal course of the posterior tibial artery: A cadaver study.

OBJECTIVE: This study aimed to describe the course, branches, and variances of the posterior tibial artery, which provides the arterial supply of the plantar surface of the foot, starting from the tarsal tunnel level to provide descriptive information for all surgical interventions, diagnostic radiological procedures, and promising endovascular therapies in the tarsal region. METHODS: In this study, a dissection of 48 feet was performed on 25 formalin-fixed cadavers (19 males and 6 females). Surgical instruments and a digital caliper were used for dissection and measurements, and the critical structures were recorded by a Canon 250D camera to be illustrated later. RESULTS: All parameters were significantly longer in male cadavers compared to females. According to the correlation analysis, while there was a significant and robust correlation between the axial line and pternion-deep plantar arch (R=.830, P .05), a moderate correlation was found between the axial line and sphyrion-bifurcation (R=.575; P < .05), axial line and deep plantar arch-2nd interdigital commissure (R=.457; P < .05), and sphyrion-bifurcation and pternion-deep plantar arch (R=.480; P < .05). Variation in any branch of the posterior tibial artery was observed in 27 of the 48 studied sides. CONCLUSION: In our study, the branching and variability of posterior tibial artery on the plantar surface of the foot were described in detail with the determined parameters. In conditions that cause tissue and function loss and require reconstruction, such as diabetes mellitus and atherosclerosis, the most critical factor in increasing treatment success is a better understanding of the region's anatomy.

Pathology of Critical Limb Ischemia; Comparison of Plaque Characteristics Between Anterior and Posterior Tibial Arteries.

AIMS: Though the number of patients with peripheral arterial disease (PAD) and critical limb ischemia (CLI) is increasing, few histopathological studies of PAD, particularly that involving below-the-knee arteries, has been reported. We analyzed the pathology of anterior tibial artery (ATA) and posterior tibial artery (PTA) specimens obtained from patients who underwent lower extremity amputation due to CLIMethods: Dissected ATAs and PTAs were subjected to ex-vivo soft X-ray radiography, followed by pathological examination using 860 histological sections. This protocol was approved by the Ethics Review Board of Nihon University Itabashi Hospital (RK-190910-01) and Kyorin University Hospital (R02-179). RESULTS: The calcified area distribution was significantly larger in PTAs than in ATAs on soft X-ray radiographic images (ATAs, 48.3% ±19.2 versus PTAs, 61.6% ±23.9; p＜0.001). Eccentric plaque with necrotic core and macrophage infiltration were more prominent in ATAs than in PTAs (eccentric plaque: ATAs, 63.7% versus PTAs, 49.1%; p＜0.0001, macrophage: ATAs, 0.29% [0.095 - 1.1%] versus PTAs, 0.12% [0.029 - 0.36%]; p＜0.001), histopathologically. Thromboembolic lesions were more frequently identified in PTAs than in ATAs (ATAs, 11.1% versus PTAs 15.8%; p＜0.05). Moreover, post-balloon injury pathology differed between ATAs and PTAs. CONCLUSIONS: Histological features differed strikingly between ATAs and PTAs obtained from CLI patients. Clarifying the pathological features of CLI would contribute to establishing therapeutic strategies for PAD, particularly disease involving below-the knee-arteries.

Distal Tibial Mononeuropathy From Compression by the Posterior Tibial Artery: Clinical-Electrophysiological-Ultrasonographic Correlations.

SUMMARY: The tibial nerve is bound tightly to the posterior tibial artery in the tarsal tunnel where expansion capacity is limited. Therefore, the nerve may be vulnerable to, and damaged by chronic pulsatile trauma from an atypically positioned overriding artery, labeled "punched-nerve syndrome". In this article, we present a 49-year-old woman who presented with two months of severe burning pain in the left medial ankle and sole of the foot without antecedent trauma. Neurological examination identified dysesthetic sensation to light touch in the left medial sole of the foot, and both active and passive dorsiflexion worsened the painful paresthesia. Nerve conduction studies demonstrated a reduced left medial plantar mixed nerve action potential amplitude, 50% less than the right. High-resolution ultrasound (HRUS) showed an increased left tibial nerve cross-sectional area of 26 mm2 (normal <22.3 mm2) at the level of the ankle with side-to-side difference of 6 mm2 (normal <5.7 mm2). The distal tibial nerve and its medial plantar branch were atypically positioned immediately deep to the left posterior tibial artery and abnormally flattened with focal enlargement of the nerve on longitudinal view. Dynamic analysis demonstrated the nerve being compressed with each pulsation of the tibial artery immediately above. Active dorsiflexion of the ankle narrowed the space underneath the flexor retinaculum resulting in further compression of the nerve against the artery. In conclusion, HRUS as an adjunct to electrophysiological studies identified punched-nerve arterial compression as an etiology of tarsal tunnel syndrome.