A comparative analysis of deep learning and hybrid iterative reconstruction algorithms with contrast-enhancement-boost post-processing on the image quality of indirect computed tomography venography of the lower extremities.

PURPOSE: To examine whether there is a significant difference in image quality between the deep learning reconstruction (DLR [AiCE, Advanced Intelligent Clear-IQ Engine]) and hybrid iterative reconstruction (HIR [AIDR 3D, adaptive iterative dose reduction three dimensional]) algorithms on the conventional enhanced and CE-boost (contrast-enhancement-boost) images of indirect computed tomography venography (CTV) of lower extremities. MATERIALS AND METHODS: In this retrospective study, seventy patients who underwent CTV from June 2021 to October 2022 to assess deep vein thrombosis and varicose veins were included. Unenhanced and enhanced images were reconstructed for AIDR 3D and AiCE, AIDR 3D-boost and AiCE-boost images were obtained using subtraction software. Objective and subjective image qualities were assessed, and radiation doses were recorded. RESULTS: The CT values of the inferior vena cava (IVC), femoral vein ( FV), and popliteal vein (PV) in the CE-boost images were approximately 1.3 (1.31-1.36) times higher than in those of the enhanced images. There were no significant differences in mean CT values of IVC, FV, and PV between AIDR 3D and AiCE, AIDR 3D-boost and AiCE-boost images. Noise in AiCE, AiCE-boost images was significantly lower than in AIDR 3D and AIDR 3D-boost images ( P < 0.05). The SNR (signal-to-noise ratio), CNR (contrast-to-noise ratio), and subjective scores of AiCE-boost images were the highest among 4 groups, surpassing AiCE, AIDR 3D, and AIDR 3D-boost images (all P < 0.05). CONCLUSION: In indirect CTV of the lower extremities images, DLR with the CE-boost technique could decrease the image noise and improve the CT values, SNR, CNR, and subjective image scores. AiCE-boost images received the highest subjective image quality score and were more readily accepted by radiologists.

Effects of the Cold Pressor Test on Popliteal Vein Diameter, Flow Velocity, and Blood Flow in the Lower Limb in 60 Healthy Individuals.

BACKGROUND In various situations such as pain, exposure to hot or cold, and mental stress, where physiological stress occurs, the increased excitatory response in the sympathetic efferent neurons leads to an increased return of blood flow from the peripheral veins to the right atrium. The cold pressor test (CPT) is based on the effects of a cold stimulus that activates afferent sensory pathways to trigger a sympathetic response, resulting in an increase in blood pressure. This study aimed to evaluate the effects of the cold pressor test on popliteal vein diameter, flow velocity, and blood flow in the lower limbs in 60 healthy individuals. MATERIAL AND METHODS We included 30 men and 30 women age 18-40 years. Baseline vein diameter, flow velocity, and blood flow of the left popliteal vein were measured by Doppler ultrasound, then the left hand was immersed in a bucket of cold water. After immersing the hand in cold water for 1 minute (CPT-1), 3 measurements of vein diameter, flow velocity, and blood flow were taken again, and their averages were calculated. RESULTS In the study, data obtained from the individuals were statistically analyzed. At CPT-1, venous diameter and flow values showed significant increase compared to baseline (P=0.001, P<0.001, respectively). CONCLUSIONS In healthy volunteers, CPT increases venous flow in the popliteal veins. However, our study did not provide evidence for the hypothesis that the increase in venous return is due to venoconstriction mechanisms.

Popliteal venous access for renal replacement therapy in a critically ill patient with central access failure.

A woman in her 80s was admitted to the emergency department with an acute infective exacerbation of chronic obstructive pulmonary disease and type 2 respiratory failure, culminating in cardiac arrest for 2 min. She was successfully resuscitated, connected to a mechanical ventilator and subsequently transferred to the intensive care unit. Later in her hospital stay, the patient underwent a tracheostomy following prolonged intubation.During this period, she developed septic shock with complications, including acute kidney injury, metabolic acidosis and volume overload. As a result, the nephrologist recommended emergency haemodialysis. Initially, a left femoral haemodialysis catheter was established but had to be withdrawn a few days later due to the development of deep vein thrombosis (DVT). A left internal jugular catheter was then inserted but was removed after 5 days due to another DVT. It was subsequently replaced with a central line for vasopressor support.A Doppler scan revealed a large thrombus in the right internal jugular vein, extending to the area just above the superior vena cava. A similar thrombus was detected in the left internal jugular vein, with weak blood flow observed in both the right and left subclavian veins. Although the subclavian vein flows were deemed adequate, there was unsatisfactory blood flow through the catheter after insertion, rendering it unsuitable for haemodialysis.Due to an earlier central line-related infection, the right femoral site exhibited signs of infection and the presence of a pus pocket, making it unsuitable for haemodialysis access. To address this, the right popliteal vein was chosen for catheterisation using a 20-cm, 12 French catheter, the longest available catheter in the country at the time. The patient was placed in a prone position, and the catheter was smoothly inserted with ultrasound guidance, resulting in good flow. Subsequent haemodialysis sessions were carried out regularly.

Lymphaticovenous anastomosis in rabbits: A novel live experimental animal model for supermicrosurgical training.

BACKGROUND: Lymphaticovenous anastomosis is widely used in lymphedema management. Although its effectiveness in reducing edema in patients can be clinically observed, evaluating the long-term outcomes of this technique can be complex. This study established an animal model to assess the outcomes of lymphaticovenous anastomosis technique at 15 and 30-days post-surgery using indocyanine green lymphography, Patent Blue V dye injection, and histopathological examination. METHODS: An experimental model was established in the hindlimbs of 10 rabbits using the popliteal vein and afferent lymphatic vessels in the popliteal area. The subjects were divided into two groups: the first group (n = 5) underwent patency assessment at 0 and 15 days, and the second group (n = 5) at 0 and 30-days, resulting in 20 anastomoses. Patency was verified at 0, 15, and 30-days using indocyanine green lymphography and Patent Blue V injection. Histopathological examinations were performed on the collected anastomosis samples. RESULTS: The patency rate was 90% (19/20) initially, 60% (6/10) at 15 days post-surgery, and 80% (8/10) at 30-days. The average diameter of lymphatic vessels and veins was 1.0 mm and 0.8 mm, respectively. The median number of collateral veins was 3; the median surgical time was 65.8 min. Histopathology revealed minimal endothelial damage and inflammatory responses due to the surgical sutures, with vascular inflammation and thrombosis in a single case. Local vascular neoformations were observed. CONCLUSION: This study highlights the reliability and reproducibility of using rabbits as experimental models for training in lymphaticovenous anastomosis technique owing to the accessibility of the surgical site and dimensions of their popliteal vasculature.

The anterior saphenous vein. Part 2. Anatomic considerations in normal and refluxing patients. Endorsed by the American Vein and Lymphatic Society, the American Venous Forum, and the International Union of Phlebology.

BACKGROUND: The term Anterior Accessory of the Great Saphenous Vein suggests this is a branch tributary vein despite this vessel's anatomic features of a truncal vein. A multisocietal group suggested to designate this the anterior saphenous vein (ASV). This study was aimed to evaluate its ultrasound anatomy in normal and varicose limbs. METHODS: The clinical anatomy of the ASV was evaluated by narrative review of the literature. Additionally, the course of the ASV was evaluated in 62 limbs with no evidence of venous disease and 62 limbs with varicosities. RESULTS: The ASV length, patterns of origin and termination are reported in both normal and patients with varicose veins. Discussion of the patterns is supported by the narrative review of the literature. CONCLUSIONS: The ASV must be considered a truncal vein and its treatment modalities should be the same that for the great and small saphenous veins rather than a tributary vein.

The study on the relationship between venous ulcer and ankle joint range of motion using ultrasound.

BACKGROUND: Chronic venous insufficiency (CVI) often leads to venous ulcers. The relationship between ankle joint range of motion (ROM) and venous ulcers remains under-investigated. This study aims to clarify this relationship using ultrasound imaging. METHODS: We conducted a study on 20 patients with unilateral venous ulcers. Ankle ROM and popliteal vein blood flow were measured using a goniometer and ultrasound, respectively. The measurements were compared between the affected and unaffected limbs. RESULTS: A significant reduction in ROM and popliteal vein blood flow was observed in the limbs with venous ulcers compared to the unaffected limbs. The data suggest a correlation between reduced ankle mobility and the development of venous ulcers. CONCLUSION: The study underscores the importance of maintaining ankle mobility in patients with CVI to prevent venous ulcers. A multifactorial approach is essential for managing these conditions effectively.

Small saphenous vein aneurysm diagnosis and treatment.

Venous aneurysms are rare, particularly those arising from the superficial venous system. Current limited evidence suggests that congenital weakness of the vein wall, degenerative changes, trauma and inflammation are among potential causes. Surgical management has been the mainstay treatment modality of venous aneurysms. Surgical approaches and techniques should be tailored on a case-by-case basis, taking into consideration aneurysm location, size, shape and presence of complications (ie, rupture or thrombosis). In this report, we present a male patient in his late thirties who presented with right leg swelling and achiness 2 years following right lower extremity blunt trauma and was found to have a 3 cm small saphenous vein aneurysm extending to the saphenopopliteal junction. The patient was successfully treated with excision of the aneurysm via a posterior approach. This case report adds to the current literature and may help to define future treatment recommendations.

Unusual approach to popliteal vein bypass graft stenosis following failed angioplasty in popliteal entrapment syndrome.

Popliteal artery entrapment syndrome (PAES) is where the popliteal artery is compressed-typically by the medial head of the gastrocnemius muscle. PAES is typically treated surgically with popliteal artery release with or without bypass. Graft stenosis is a recognised complication of vein grafts. These are normally treated endovascularly. Endarterectomy of venous graft stenosis may be a useful tool in selected cases, where an endovascular approach was unsuccessful. Long-term follow-up of graft stenosis endarterectomy will allow us to determine effectiveness of this method of treatment where other options have failed.

Venous compression syndromes in females: A descriptive review.

Venous compression syndromes have been described, yet the role of sex is poorly understood. Although iliac vein compression has been discussed more often with the advent of newer technologies, research has fallen short on defining epidemiology, best practices for evaluation and treatment, and differences in responses to treatment between men and females. The authors report on iliac vein compression, nonthrombotic renal vein compression, and other venous compression syndromes in females. Literature searches of PubMed were performed using the following keywords: females/females and May Thurner, venous stenting, venous outcomes, deep venous disease, deep venous compression, venous stenting, renal vein compression, renal vein surgery/stent, popliteal vein entrapment, venous thoracic vein entrapment, and popliteal vein entrapment. The articles prompted the authors to research further as the referenced articles were reviewed. Sex representation has not been addressed adequately in the research of venous compression syndromes, making the discussion of best treatment options and long-term outcomes difficult. More specific understanding of epidemiology and response to interventions will only come from research that addresses these issues directly, understanding that some of these syndromes occur rarely.

[An overview of treatment options for a rare disease, aneurysm of the popliteal vein, in connection with a case]. / Egy ritka kórkép, a vena poplitea aneurysma kezelési lehetoségeinek áttekintése egy eset kapcsán.

INTRODUCTION: Popliteal vein aneurysm is a rare, but potentially life-threatening condition that can lead to deep vein thrombosis and/or pulmonary embolism. It is often asymptomatic, but symptoms may include pain, post-thrombotic syndrome or chronic venous insufficiency. An experienced physician may be able to detect a palpable mass in the popliteal fossa. Duplex ultrasound is the first line of diagnosis. CT or MR venography play a role in the diagnosis. OBJECTIVE: To review the international literature, explain the possible treatment options, and present our case. CASE REPORT: A 62-year-old female patient had a recurrent pulmonary embolism while on direct-acting oral anticoagulant therapy. Duplex ultrasound and MR angiography were performed and confirmed a partially thrombosed aneurysm of the right popliteal vein. Aneurysm resection and venorrhaphy were performed as treatment. At follow-up, ultrasound showed adequate flow in the deep venous system. 6 months later, the control MR angiography showed good flow without stenosis. There were no postoperative complications. Discussion and literature review: The pathomechanism of the disease remains unclear. Treatment options are conservative therapy and/or surgical intervention, but there is no consensus regarding the therapy of symptomatic or asymptomatic cases. There is no clear statement regarding the method and duration of postoperative anticoagulant therapy. CONCLUSION: In the case of recurrent pulmonary embolism, the possibility of a popliteal vein aneurysm should be considered. Ultrasound is a non-invasive, widely available initial diagnostic tool. In addition to conservative treatment, the possibility of surgical intervention can be considered. The surgical procedure described in our case was successful. Orv Hetil. 2023; 164(39): 1544-1549.

Institutional Experience With Venous Aneurysms - Insights On The Natural History And Outcomes Of Surgical Treatment.

INTRODUCTION: Venous aneurysms are rare, so their natural history is not fully understood. Indications for treatment are often determined by the location and size of the aneurysm; however, considering the scarcity of data, there are no specific recommendations. Surgery is the mainstay for venous aneurysm treatment, but some authors reported successful endovascular treatment. We intend to describe our experience with this type of rare disorder. METHODS: A post hoc observational study of a prospectively maintained registry including consecutive patients admitted with the diagnosis of a venous aneurysm at different locations between January 2007 and September 2021. Demographic data, anatomic location, and medical history, including trauma or venous surgery, were analyzed. All vascular reconstructions and outcomes have been evaluated. RESULTS: We identified 30 venous aneurysms in 24 patients. Fifteen patients were male (63%). The most common anatomical location was the popliteal vein (n=19; 63%). Four patients had multiple venous aneurysms, and three patients had synchronous arterial aneurysms. Twelve (63%) of the popliteal vein aneurysms identified were surgically treated, most commonly by tangential aneurysmectomy and lateral venorrhaphy. The average diameter at the time of surgery was 22,8±3,6 mm. After discharge, all patients were anticoagulated for 6 to 12 months, in most cases with rivaroxaban. With a median follow-up time of 32 months (12 - 168 months), primary patency was 92%. Aneurysm recurrence was only observed in one case (1/12; 8%) with non-occlusive thrombosis of the aneurysm 14 years after surgery. One patient had a 21 mm gemelar vein aneurysm, having been proposed for surgery, with thrombosis before the intervention. Two patients had common femoral vein aneurysms treated with partial aneurysmectomy and lateral venorrhaphy without thromboembolic events during follow-up. Two patients presented with portal system aneurysms, one associated with portal hypertension. No treatment was performed, and an increase in aneurysm size was observed during follow-up. Another patient presented with acute deep vein thrombosis on chronically thrombosed bilateral iliac vein aneurysms. Three patients had aneurysms of the superficial venous system associated with previous trauma, which were treated with simple ligation and excision. CONCLUSION: Venous aneurysms are rare and most commonly located in the popliteal vein, which seems to be associated with chronic venous disease. Treating these aneurysms, even without symptoms, can be important to avoid thromboembolic complications. However, close long-term follow-up with duplex ultrasound should be considered to detect late recurrence. Aneurysms from other locations are even rarer, and treatment decisions should be individualized, weighing the risks and benefits of the intervention.

Factors Affecting Recanalization in Femoropopliteal Deep Vein Thrombosis.

Effects of warfarin and new-generation direct oral anticoagulants (DOACs) on thrombus resolution after the treatment of deep vein thrombosis (DVT) are still unknown. The study aimed to investigate the effects of warfarin and DOACs on thrombus resolution after DVT treatment. Methods: The study included 666 patients who were diagnosed with femoropopliteal DVT between January 2016 and January 2022 and had complete medical records without missing data. Patients with and without recanalization were added to groups 1 (n = 396) and 2 (n = 270), respectively. Ultrasonography/venous Doppler examinations of the patients during follow-up were performed by 3 radiologists. Recanalization was defined as the presence of complete flow in the femoral and popliteal veins and the absence of residual venous thrombus. Results: Among the included patients, recanalization was observed in 59.5% patients. The mean follow-up period was 23.6 ± 17.8 (range 1-72; median 17) months. There was no difference between the 2 groups in terms of the types of drugs used in the treatment (P = .208). Cox regression models were used to investigate the factors affecting recanalization. Analysis of the variables having significant differences between both groups revealed the low rate of recanalization in patients with coronary artery disease (odds ratio [OR], 2.3%; 95% confidence intervals [CI]: 1.6-3.4; P < .001) and diabetes mellitus (OR, 1.5; 95% CI: 1.1-1.9; P = .009). Conclusion: Thrombus resolution after femoropopliteal DVT is not affected by the drugs used in the treatment.

Effects on hemodynamic enhancement and discomfort of a new textile electrode integrated in a sock during calf neuromuscular electrical stimulation.

PURPOSE: To compare fixed transverse textile electrodes (TTE) knitted into a sock versus motor point placed standard gel electrodes (MPE) on peak venous velocity (PVV) and discomfort, during calf neuromuscular electrical stimulation (calf-NMES). METHODS: Ten healthy participants received calf-NMES with increasing intensity until plantar flexion (measurement level I = ML I), and an additional mean 4 mA intensity (ML II), utilizing TTE and MPE. PVV was measured with Doppler ultrasound in the popliteal and femoral veins at baseline, ML I and II. Discomfort was assessed with a numerical rating scale (NRS, 0-10). Significance was set to p < 0.05. RESULTS: TTE and MPE both induced significant increases in PVV from baseline to ML I and significantly higher increases to ML II, in both the popliteal and femoral veins (all p < 0.001). The popliteal increases of PVV from baseline to both ML I and II were significantly higher with TTE versus MPE (p < 0.05). The femoral increases of PVV from baseline to both ML I and II were not significantly different between TTE and MPE. TTE versus MPE resulted at ML I in higher mA and NRS (p < 0.001), and at ML II in higher mA (p = 0.005) while NRS was not significantly different. CONCLUSION: TTE integrated in a sock produces intensity-dependent increases of popliteal and femoral hemodynamics comparable to MPE, but results in more discomfort at plantar flexion due to higher current required. TTE exhibits in the popliteal vein higher increases of PVV compared to MPE. TRIAL REGISTRATION: Trial_ID: ISRCTN49260430. Date: 11/01/2022. Retrospectively registered.

Renal replacement therapy via popliteal vein for exhausted vascular access in emergency: A case report.

A 59 year-old man was admitted as his left antecubital arterio-venous fistula was thrombosed, and hemodialysis could not be succeeded for the last two sessions. It was a brachio-basilic fistula without transposition, which also required thrombectomy 8 months ago, and had been created 18 months before. He had multiple catheter insertions during the period of 6 years. Following the failed catheter insertions from both jugular and femoral veins, an ultrasound-guided venography via the left popliteal vein demonstrated the intact left popliteal and femoral vein with well-developed collaterals at the level of occluded left iliac vein. A temporary hemodialysis catheter was placed through the popliteal vein with an antegrade manner under ultrasound guidance in prone position, which effectively worked during hemodialysis sessions afterwards. Transposition of basilic vein was performed. Following the wound recovery, arterialized basilic vein has started to be used effectively for hemodialysis, and the popliteal catheter was displaced.

Point-Of-Care Ultrasound Screening for Proximal Lower Extremity Deep Venous Thrombosis.

Acute lower extremity deep venous thrombosis (DVT) is a serious vascular disorder that requires accurate and early diagnosis to prevent life-threatening sequelae. While whole leg compression ultrasound with color and spectral Doppler is commonly performed in radiology and vascular labs, point-of-care ultrasound (POCUS) is becoming more common in the acute care setting. Providers appropriately trained in focused POCUS can perform a rapid bedside examination with high sensitivity and specificity in critically ill patients. This paper describes a simplified yet validated approach to POCUS by describing a three-zone protocol for lower extremity DVT POCUS image acquisition. The protocol explains the steps in obtaining vascular images at six compression points in the lower extremity. Beginning at the level of the proximal thigh and moving distally to the popliteal space, the protocol guides the user through each of the compression points in a stepwise manner: from the common femoral vein to the femoral and deep femoral vein bifurcation, and, finally, to the popliteal vein. Further, a visual aid is provided that may assist providers during real-time image acquisition. The goal in presenting this protocol is to help make proximal lower extremity DVT exams more accessible and efficient for POCUS users at the patient's bedside.

Pedal Musculovenous Pump Activation Effectively Counteracts Negative Impact of Knee Flexion on Human Popliteal Venous Flow.

Knee scooters are commonly used for mobility instead of other devices. However, passive popliteal venous flow impedance has been observed with knee scooter usage ostensibly as a result of deep knee flexion. This study aimed to characterize the magnitude of impact knee flexion has on popliteal venous flow in relation to the degree of knee flexion when walking boot immobilized. Furthermore, the countervailing effect of standardized pedal musculovenous pump (PMP) activation was observed. Popliteal venous diameter and flow metrics were assessed with venous ultrasonography in 24 healthy individuals. Straight leg, crutch, and knee scooter positioning while wearing a walking boot and non-weight-bearing were compared. Flow was assessed with muscles at rest and with PMP activation. Of 24 participants, 16 (67%) were female. Twelve limbs (50%) were right sided. The mean age was 21.9 (SD = 3.0) years, and the mean body mass index was 21.9 (SD 1.9) kg/m2. Observer consistencies were excellent (intraclass correlation range = 0.93 to 0.99). No significant differences in mean vessel diameter, time-averaged mean velocity, and total volume flow occurred (all P > .01). Corresponding knee flexion effect sizes were small (range = -0.04 to -0.26). A significant decrease (-24%) in active median time-averaged peak velocity occurred between upright and crutch positions (20.89 vs 15.92 cm/s; P < .001) with a medium effect size (-0.51). PMP activation increased all flow parameters (all P < .001), and effect sizes were comparatively larger (>0.6) across all knee flexion positions.Clinical Significance: Knee flexion has a small to medium impact on popliteal venous return in healthy patients. Active toe motion effectively counters the negative effects of gravity and knee flexion when the ankle is immobilized.Levels of Evidence: Therapeutic, Level IV.

Cystic Adventitial Disease of the Popliteal Vein: A Case Report.

Venous cystic adventitial disease (VCAD) is a rare vascular anomaly located in the common femoral vein in most cases. We describe the case of a 59-year-old female patient with right leg edema who was misdiagnosed with deep vein thrombosis of the lower extremity at another hospital. Magnetic resonance angiography revealed a round mass in the popliteal vein, with a narrow lumen. Considering the location of the lesion, absence of a history of deep venous thrombosis and trauma, and clinical manifestations, the diagnosis is likely a popliteal vein adventitial cyst. Segmental popliteal vein resection and reconstruction were performed using a cylindrical great saphenous vein graft. No joint connection was found during the operation, and the postoperative pathology confirmed VCAD.