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.

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.

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.

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.

Successful Coil Embolization of a Large Anterior Tibial Artery Pseudoaneurysm After Open Reduction Internal Fixation of a Bi-condylar Tibial Plateau Fracture.

Pseudoaneurysms are false aneurysms that consist of turbulent blood flow between the outside layers of the arterial wall, the tunica media and tunica adventitia. Typically, pseudoaneurysms develop after injury to an artery, most often as a result of blunt trauma. Femoral pseudoaneurysms can also develop after catheter-based vascular interventions due to laceration of the artery from access needles, insufficient time or pressure held at the access site after the procedure, amongst other causes. Rarely, arterial injury during orthopedic pinning procedures has been known to cause pseudoaneurysms. There are only two documented cases within the literature in which a patient underwent closed intermedullary nailing of a proximal tibia fracture after trauma and developed an anterior tibial artery pseudoaneurysm. There are few reports of pseudoaneurysm development as the result of external fixation device placement presumably caused by the inability to directly visualize internal anatomy.

Three-Dimensional Digitalized Virtual Planning of Free Anterior Tibial Artery Perforator Flap for Repairing Soft Tissue Defects in Extremities.

BACKGROUND: Traditional research methods have limited the application of anterior tibial artery perforator flap due to incomplete knowledge of the perforator. This study aimed to investigate the feasibility of three-dimensional digitalized virtual planning of free anterior tibial artery perforator flap for repairing soft tissue defects in extremities. METHODS: A total of 11 patients with soft tissue defects in extremities were included. The patient underwent computed tomography angiography (CTA) of bilateral lower limbs, and then the three-dimensional models of bones, arteries, and skin were constructed. Septocutaneous perforators with appropriate length and diameter were selected to design anterior tibial artery perforator flaps in software, and the virtual flaps were superimposed onto the patient's donor site in a translucent state. During the operation, the flaps were dissected and anastomosed to the proximal blood vessel of the defects as designed. RESULTS: Three-dimensional modeling showed clear anatomical relationships between bones, arteries, and skin. The origin, course, location, diameter, and length of the perforator obtained during the operation were consistent with those observed preoperatively. Eleven anterior tibial artery perforator flaps were successfully dissected and transplanted. Postoperative venous crisis occurred in one flap, partial epidermis necrosis occurred in another flap, while the remaining flaps completely survived. One flap was treated with debulking operation. The remaining flaps maintained aesthetic appearance, which did not affect the function of the affected limbs. CONCLUSIONS: Three-dimensional digitalized technology can provide comprehensive information on anterior tibial artery perforators, thus assisting in planning and dissecting patient-specific flaps for repairing soft tissue defects in extremities.

Anomalous Posterior Tibial Artery Course-Anatomic Considerations for the Posterolateral Ankle Approach: A Case Report.

CASE: We report a unique anatomical case of an anomalous course of the posterior tibial artery found on dissection during the posterolateral approach to the ankle. To the best of our knowledge, no such case has been documented. CONCLUSION: The vascular bundle consistent with that of the posterior tibial artery and vein was encountered in the far lateral aspect of the deep posterior compartment, which suggests physicians should proceed with caution when performing the posterolateral approach to the ankle so as to avoid iatrogenic injury of this named anatomic structure.

Pulsatility index-adjusted doppler flow measurement of pedal arteries in peripheral artery disease patients.

BACKGROUND: To examine the feasibility of using pulsatility index-adjusted (PI) flow equations to accurately characterize blood volume flow changes using Doppler technique in patients with peripheral artery disease (PAD) before and after percutaneous transluminal angioplasty (PTA). METHODS: PTA was performed on 17 PAD patients (23 target vessels treated, 16 anterior tibial arteries, and 7 posterior tibial arteries). Arterial diameter, peak systolic velocity, PI, time-averaged mean velocity, and measured volume flow (MVF) of dorsalis pedis artery (DPA) and common plantar artery (CPA) were measured with duplex Doppler ultrasound before and after PTA. PI-adjusted volume flows (PIVF) were calculated as part of the MVF/PIVF relative percentage metric. RESULTS: Significant changes (p < 0.001) of the MVF (mean: 33.0 mL/min, range: -20.9-102.2 mL/min) and MVF/PIVF relative percentages (mean: 51.8, range: 5.1-127.2%) in the DPA existed between before and after PTA, whereas no significant changes could be found in the CPA (mean:10.9 mL/min, p = 0.148 and mean: 21.3%, p = 0.146, respectively). Of the 7 treated posterior tibial arteries, the increments of the MVF/PIVF (mean: 60.4%, p = 0.033) was significant but not in the MVF (mean: 26.5 mL/min, p = 0.125). The ankle-brachial index also showed non-significant changes (p = 0.081). All PI-adjusted results matched clinical observations after blood flow restoration. CONCLUSION: No conclusions can be drawn from the comparison of actual measured volume flow between before and after PTA. However, using the MVF/PIVF relative percentage allows for a more objective framework upon which to base clinical observations and provides clarity in situations where direct measurement provides a counter-intuitive or contradictory picture.

Anterior Tibial to Dorsalis Pedis Bypass to Manage Acute Ischemia Attributed to Pilon Fracture.

Pilon fractures of the distal tibia are usually the result of a high-energy trauma and can affect seriously the arterial vasculature carrying an increased risk of amputation at the malleolar level or higher. Such cases represent a challenge for the orthopedic surgeons and a multidisciplinary approach is mandatory in order to salvage the threatened limb. We present an unusual case of a closed pilon fracture with injury of all tibial vessels leading to acute limb threatening ischemia. The patient was treated successfully with external fixation and a short tibial-pedal bypass with use of an autologous reversed saphenous vein graft. This example dictates how a distal leg fracture can be dramatic and that awareness of vascular examination coupled with high suspicion of vascular damage can be limb-saving. Multidisciplinary approach is warranted since the topology and complexity of the ankle lesions necessitate staged orthopedic reconstructions with tibio-distal bypass and appropriate skin coverage of the distal anastomosis.

Tortuosity and Pulsatility of the Tibial Artery - Two Case Reports of a Rare Etiology of Tarsal Tunnel Syndrome.

Tarsal tunnel syndrome is a neuropathic compression of the tibial nerve and its branches on the medial side of the ankle. It is a challenging diagnosis that constitutes symptoms arising from damage to the posterior tibial nerve or its branches as they proceed through the tarsal tunnel below the flexor retinaculum in the medial ankle, easily forgotten and underdiagnosed. Neural compression by vascular structures has been suggested as a possible etiology in some clinical conditions. Tibial artery tortuosity is not that rare, but only that it affects the nerve can cause tarsal tunnel syndrome. Therefore, a study care must be taken to avoid false-positive errors.

Ultrasound-guided retrograde tibial access through chronically occluded tibial arteries: a last resort recanalization technique.

PURPOSE We aimed to demonstrate the feasibility of ultrasound (US)-guided retrograde tibial access through chronically occluded tibial arteries as a bailout endovascular recanalization procedure in patients with critical limb ischemia (CLI). METHODS Fifty-one CLI patients with failed conventional antegrade tibiopedal recanalization required retrograde tibiopedal access in the same session. In all of these patients, the target tibial artery was chronically occluded in at least the distal half of the cruris. Access attempts were made under real-time US by a single operator experienced in image-guided vascular access procedures. Fluoroscopy was used only as an adjunct during advancement of a 0.018 inch guidewire. If access to the artery was successful by the retrograde route, the occluded artery was usually predilated with a 2 mm balloon, and the standard endovascular treatment was mostly performed through the antegrade route. RESULTS Patients had athereosclerosis (n=35) or Buerger's disease (n=32) and presented with Rutherford category IV and category V. Successful placement of a guidewire in the occluded artery lumen was achieved in 81% of all patients, whereas, treatment success, i.e. angiographic demonstration of in-line flow at the end of procedure, was achieved in 49%. No significant procedure-related complications were observed. Of 33 limbs with initially successful endovascular treatment, 6 required minor and 1 required major amputation during follow-up. CONCLUSION US-guided retrograde access through completely occluded tibial arteries is difficult but feasible. Half of the tibial arteries that could not be recanalized otherwise were converted to successful recanalization by this method.