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.

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.

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.

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.

Popliteal cysts are not a risk factor for lower extremity deep vein thrombosis.

BACKGROUND: Popliteal cysts (PC) result from distension of the gastrocnemio-semimembranosous bursa. Published reports indicate coincident PC and deep vein thrombosis (DVT). Whether the presence of PC increase the risk of deep vein thrombosis (DVT) remains unclear. METHODS: Lower extremity venous Duplex ultrasound (DUS) reports were evaluated across the Mayo Clinic Enterprise (Rochester, Minnesota, Jacksonville, Florida, Scottsdale, Arizona, and the Mayo Clinic Health System) in patients ≥ 18 years of age. Natural language processing (NLP) algorithms were created and validated to identify acute lower extremity DVT and PC from these reports. To determine whether there is a link between PC and lower extremity DVT, the frequency of PC among cases (ultrasounds with acute DVT) were compared to controls (ultrasounds without acute DVT). RESULTS: A total of 357,703 lower extremities venous DUS were performed in 237,052 patients (mean age 63.3 ± 16.6, 54.4% were female) between 1992 and 2021. Acute DVT was identified in 32,572 (9.1%) DUS, and PC in 32,448 (9.1%). PC were seen in a lower frequency (8.0%) of ultrasounds with acute DVT than those without (9.2%) acute DVT (OR: 0.85, 95% CI: 0.82 to 0.89, p < 0.001). In a multivariate logistic regression model after adjusting for age, sex, and race, PCs were not positively associated with acute DVT (adjusted OR: 0.84, 95% CI: 0.81 to 0.88). CONCLUSIONS: PC are an incidental finding or an alternative diagnosis on lower extremity venous DUS, a finding that increases significantly with age. PC were not a risk factor in the development of lower extremity DVT.

Distribution of Lower Extremity Deep Vein Thrombosis and Implications for Limited Compression Ultrasound Examinations.

BACKGROUND: Limited compression bedside ultrasonography (LCUS) including two-point, three-point, and extended compression examinations have become increasingly popular among emergency physicians to assess for lower extremity deep venous thrombosis (DVT). OBJECTIVE: Our objective in this study was to determine the prevalence and distribution of lower extremity DVT in sites identified by complete duplex ultrasonography (CDUS) that may potentially be missed using limited compression ultrasonography techniques. METHODS: This was a retrospective, multicenter study conducted at 12 hospitals within the Northwell Health system over a span of 4 years. Study participants (emergency department patients) underwent CDUS to assess for possible DVT. Images were reviewed and interpreted by radiologists and vascular surgeons at each of the participating institutions. RESULTS: A total of 42,487 CDUS examinations were performed, of which 3383 were positive for DVT. DVTs were deemed to be acute in 2664 (79%) and chronic in the remaining 21% on the basis of comparison with previous studies and appearance of the vein. Of the acute DVTs, 136 (5.1%) were confined to the common femoral vein, 116 (4.4%) to the femoral vein, 8 (0.3%) to deep femoral vein, 213 (8.0%) to popliteal vein, and 934 (35.1) to calf veins alone. CONCLUSIONS: In our study, a significant number of DVTs were identified in sites that may have been potentially missed on LCUS examinations, thereby supporting the use of complete duplex ultrasonography when available.

Lower leg mass in pulmonary embolism: a case of popliteal vein aneurysm.

Popliteal vein aneurysms (PVAs) are rare entities, with less than 300 hundred cases reported in the global literature. Despite their rarity, they have immense consequences, having the potential to lead to life-threatening conditions such as pulmonary embolisms and even death. Hence, it is vital for clinicians to be aware of this condition. In this paper, we report a case of PVA and its imaging features seen on the varying imaging modalities. Diagnosis often may not be straightforward as it can mimic other non-vascular or soft tissue masses, hence understanding and appreciating its specific imaging appearances is essential. Generally, PVAs are treated surgically with good outcomes with no reported mortality or recurrence of pulmonary embolism.

Impact of concomitant popliteal vein thrombosis in patients with acute iliofemoral deep vein thrombosis treated with endovascular early thrombus removal.

Background: Catheter-based thrombus removal (CBTR) reduces the risk of moderate to severe post-thrombotic syndrome (PTS) in patients with acute iliofemoral deep vein thrombosis (IF-DVT). However, the impact of concomitant popliteal DVT on clinical and duplex sonographic outcomes is unknown. Patients and methods: In this post-hoc analysis including the entire cohort of the randomized controlled BERNUTIFUL trial (48 patients), we compared clinical (incidence/severity of PTS assessed by Villalta score and revised venous clinical severity scores, rVCSS), disease-specific quality-of-life (QOL, CIVIQ-20 survey) and duplex sonographic outcomes (patency, reflux, post-thrombotic lesions) at 12 months follow-up between patients with IF-DVT with and without concomitant popliteal DVT treated by CBTR. Results: Overall, 48 IF-DVT patients were included (48% men, median age of 50 years), of whom 17 (35%) presented with popliteal DVT. At baseline, patients with popliteal DVT were older, had a higher body mass index and more important leg swelling. At 12 months, freedom from PTS (93% vs 87%, P=0.17), median total Villalta score (1 vs 1.5; P=0.46), rVCSS (2 vs 1.5, P=0.5) and disease-specific QOL (24 points vs 24 points, P=0.72) were similar between patient with and without popliteal DVT, respectively. Duplex sonographic outcomes were similar, except for more frequent popliteal post-thrombotic lesions and reflux (P=0.02) in patients with popliteal DVT. Conclusions: Relevant clinical outcomes 1 year after successful CBTR were favorable, regardless of the presence or absence of concomitant popliteal DVT. However, post-thrombotic popliteal vein lesions and reflux are more frequent in IF-DVT patients with popliteal involvement. Their impact on long-term outcomes remains to be investigated.

Two New Methods of Supine Venographically Guided Popliteal Vein Puncture: A Retrospective Study.

OBJECTIVE: Presently, the prone position is necessary for popliteal vein puncture access, but it makes the patients uncomfortable and does not allow traditional femoral or jugular access. To address these deficiencies, this study introduces two new methods, anterior and medial access carried out in the supine position. METHODS: Venous interventions with punctures in the popliteal vein of 120 limbs in 97 patients were performed during the period from February 2017 to April 2019. After puncture, venographic guidance was achieved by dorsal vein injection of contrast medium. Interventional therapy was performed after puncture and insertion of the introducer sheath. RESULTS: In all, 120 limbs were punctured in the popliteal vein, with technical success in 118 (98.3% in total) cases: 100%, 96.1%, and 100% successful punctures in, respectively, 32 anterior, 49 medial, and 37 posterior access cases. A comparison of the three groups revealed that the fluoroscopy time and duration of puncture were longer in the medial and anterior access groups than in the posterior access group. The rate of intra-operative and post-operative complications was 7.5% (9/120), with no statistically significant difference between the three access groups. Compared with the pre-operative median score of 2.5, the post-operative SVS (Society of Vascular Surgery) score of the popliteal vein was reduced to 1.5 in the anterior and 0.5 in the medial groups. CONCLUSION: Medial and anterior puncture of the popliteal vein in the supine position can be used as a safe alternative in venous endovascular therapy. The two new methods can mitigate frailty or respiratory problems resulting from the prone position and facilitate traditional femoral and jugular access.

Early Results of Popliteal Vein External Banding for Treatment of Chronic Venous Insufficiency.

BACKGROUND: Chronic venous insufficiency (CVI) encompasses a myriad of clinical manifestations including lower extremity swelling and pain, ulcerations and chronic skin changes such as stasis dermatitis, and lipodermatosclerosis. CVI effects greater than 25 million Americans and has a significant socioeconomic and psychosocial impact. Treatment of CVI varies depending on the etiology. For those patients with deep venous reflux, restoration of the deep venous valvular system is critical. Popliteal vein external banding is a novel technique to treat deep venous reflux. Our study aims to retrospectively review the early outcomes for the largest U.S. series of patients undergoing popliteal vein external banding. METHODS: Patients with C4, C5, and C6 disease with underlying deep venous reflux were treated with external banding of the popliteal vein. Basic demographic, ultrasound, and procedural data were collected. Patients were seen in clinic and underwent post procedure duplex. Procedure-specific complications were also assessed. The primary outcome was improvement of symptoms or wound healing. RESULTS: Twelve patients were identified. Seventy-five percent of patients had a history of DVT on the ipsilateral extremity and 66.7% (n = 6) of those patients had previous common or external iliac vein stenting for post-phlebitic syndrome. 58.3% of patients had active ulcerations (C6) at the time of popliteal vein banding and the mean VCSS score was 12.7, consistent with advanced venous disease. Patients were followed for a mean 8.62 months. Of the 8 patients that had active ulcers (C6), 75% completely healed with a mean time to healing of 3.3 months. 91.6% of patients reported clinical improvement in their symptoms (i.e., reduction in edema/swelling, pain or improvement in size of ulcer). Three patients had post-operative wound complications and 1 required oral antibiotic for associated cellulitis. CONCLUSION: Popliteal vein external banding represents a viable treatment modality for patients with venous insufficiency secondary to deep venous reflux. It is technically easier than most deep venous reconstructive options and may have an important role in the multimodal treatment of patients with advanced CVI.

Postpartum fever and radicular low back pain.

Fever and low back pain with radicular symptoms raise concern for epidural abscess or other neuraxial infection, especially in the context of recent epidural anesthesia. Here we present an unusual case with several confounding factors and an unexpected diagnosis.

The impact of graduated compression stockings on calf-vein deformation and blood velocity in patients awaiting total knee arthroplasty.

OBJECTIVES: This study was designed to explore venous deformation of the lower extremities and the changes in venous hemodynamics in supine position before and after wearing graduated elastic stockings in patients awaiting total knee arthroplasty (TKA). METHOD: The leg veins of 21 elderly patients awaiting TKA were imaged in the supine position with and without knee-length graduated compression stockings (GCS) according to a fixed protocol. Measured parameters including the lateromedial (LM) diameter, anteroposterior (AP) diameter, and cross-sectional area (CSA) of the great saphenous vein (GSV), gastrocnemius vein (GV), soleus vein (SV), posterior tibial vein (PTV), fibular vein (FV), and anterior tibial vein (ATV). In addition, the mean and maximum velocities of the popliteal vein (PV) and superficial femoral vein (FSV) were measured. RESULTS: GCS-related compression was observed for all the measured veins. Maximal reduction was observed for the GV and SV, whereas the GSV exhibited the lowest degree of GCS-related compression. The mean cross-sectional area reduction values associated with GCS were 33.1 ± 41.2 % for the GSV, 94.8 ± 11.1 % for the GV, and 85.6 ± 20.3 % for the SV, while the mean reduction of anteroposterior diameter was 18.1 ± 34.5 % for the GSV, 89.0 ± 22.5 % for the GV, and 72.9 ± 35.1 % for the SV, and the mean reduction of the lateromedial diameter was 25.9 ± 36.4 % for the GSV, 89.6 ± 19.6 % for the GV, 78.2 ± 28.3 % for the SV. No significant GCS-related changes in blood velocity in the superficial femoral veins or popliteal veins were detected. CONCLUSIONS: For elderly patients awaiting TKA, knee-length GCS can significantly reduce calf vein dilation while at rest in the supine position, with the greatest reductions being observed for the soleus and gastrocnemius veins. These data might help provide a theoretical basis for the GCS in reducing incidence of deep vein thrombosis in patients undergoing TKA.

Clinical course of acute deep vein thrombosis of the legs in Behçet's syndrome.

OBJECTIVES: Lower extremity deep vein thrombosis (LEDVT) is a serious complication of Behçet's syndrome. Management constitutes mainly of administration of immunosuppressives, but the predictors of relapse and the optimal choice of immunosuppressives remain unclear. In this prospective study, we aimed to detect the risk and predictors of relapse and treatment response to different modalities. METHODS: All Behçet's syndrome patients who presented with a first episode of acute LEDVT between 2010 and 2014 were prospectively followed with a standard protocol. Acute LEDVT was confirmed by Doppler ultrasonography. Serial planned Doppler ultrasonography assessments were performed during follow-up and additionally repeated in case of clinical suspicion. Recanalization rate was assessed at each visit. Our first-line treatment strategy consisted of AZA and CSs. IFN-alpha was used in patients who were refractory to or could not tolerate AZA or had concomitant eye involvement requiring further treatment. RESULTS: Thirty-three patients with LEDVT (26 M/7 F) were prospectively followed for 40.7 ± 13.4 months. Among the 33 patients, 23 relapses were observed in 15 patients. Relapse rates were 29%, 37% and 45% at 6, 12 and 24 months, respectively. Among the possible predictors of relapse, poor recanalization was the only significant factor [hazard ratio 4.34 (95% CI 1.96, 10.0)]. Overall 29 patients were treated with AZA and 17 with IFN-alpha. The relapse rate was lower and recanalization rate was higher with IFN-alpha compared with AZA (12% vs 45% and 86% vs 45%). CONCLUSION: The relapse rate for LEDVT in Behçet's syndrome is high despite AZA treatment. IFN-alpha seems to be a promising agent for preventing LEDVT relapses and achieving good recanalization.

CT Angiographic Evaluation of Congenital Anastomoses between Femoropopliteal Vein and Deep Femoral Vein: Types and Incidence.

PURPOSE: To evaluate congenital anastomotic channels between femoropopliteal veins and deep femoral veins with the use of computed tomographic (CT) venography. MATERIALS AND METHODS: CT venography of 488 limbs in 244 patients (105 men; mean age, 61 y; age range, 18-96 y) performed between January 2016 and December 2016 was retrospectively evaluated. The presence or absence of anastomotic channels (> 3 mm in diameter) connecting a femoropopliteal vein to a deep femoral vein was determined, and the observed channels were classified based on their location and course. RESULTS: Two types of anastomotic channels were observed in 32 patients (13%): a persistent sciatic vein (PSV) in 24 limbs of 15 patients (6%) and a retrofemoral channel (RFC) in 22 limbs of 19 patients (8%). A PSV anastomosed with the popliteal vein in the popliteal fossa, coursed posterior to the adductor magnus muscle, and drained into the deep femoral vein. An RFC anastomosed with the femoral vein at the level of the adductor hiatus, coursed posterior to the femoral shaft, and drained into the deep femoral vein. PSVs and RFCs were of similar size or larger than adjacent femoropopliteal veins in 50% (12 of 24) and 22% of limbs (4 of 22), respectively. CONCLUSIONS: Anastomotic channels connecting a femoropopliteal vein to a deep femoral vein are not a rare variation and may have an important role in collateral venous drainage of the lower extremities.

Correlation between Post-Procedure Residual Thrombus and Clinical Outcome in Deep Vein Thrombosis Patients Receiving Pharmacomechanical Thrombolysis in a Multicenter Randomized Trial.

PURPOSE: To evaluate relationships between immediate venographic results and clinical outcomes of pharmacomechanical catheter-directed thrombolysis (PCDT). MATERIALS AND METHODS: Venograms from 317 patients with acute proximal deep vein thrombosis (DVT) who received PCDT in a multicenter randomized trial were reviewed. Quantitative thrombus resolution was assessed by independent readers using a modified Marder scale. The physician operators recorded their visual assessments of thrombus regression and venous flow. These immediate post-procedure results were correlated with patient outcomes at 1, 12, and 24 months. RESULTS: PCDT produced substantial thrombus removal (P < .001 for pre-PCDT vs. post-PCDT thrombus scores in all segments). At procedure end, spontaneous venous flow was present in 99% of iliofemoral venous segments and in 89% of femoral-popliteal venous segments. For the overall proximal DVT population, and for the femoral-popliteal DVT subgroup, post-PCDT thrombus volume did not correlate with 1-month or 24-month outcomes. For the iliofemoral DVT subgroup, over 1 and 24 months, symptom severity scores were higher (worse), and venous disease-specific quality of life (QOL) scores were lower (worse) in patients with greater post-PCDT thrombus volume, with the difference reaching statistical significance for the 24-month Villalta post-thrombotic syndrome (PTS) severity score (P = .0098). Post-PCDT thrombus volume did not correlate with 12-month valvular reflux. CONCLUSIONS: PCDT successfully removes thrombus in acute proximal DVT. However, the residual thrombus burden at procedure end does not correlate with the occurrence of PTS during the subsequent 24 months. In iliofemoral DVT, lower residual thrombus burden correlates with reduced PTS severity and possibly also with improved venous QOL and fewer early symptoms.

Anatomical Considerations of Infrageniculate Popliteal Artery Puncture: Alternative Pathway for Retrograde Access After Failed Re-entry.

BACKGROUND: A distal approach in endovascular procedures for revascularization of lowers limbs can be considered in case of no re-entry in subintimal recanalization. The aim of this study is to evaluate the feasibility of a medial approach to the infrageniculate popliteal artery (IPA) using existing computed tomography (CT) scan simulation and punctures performed on cadavers. METHODS AND RESULTS: CT angiographies of lower extremities were used to simulate IPA puncture and puncture trajectory. Tissues damaged during the trajectory between the puncture site and the access-related injuries were analyzed. Anatomical punctures on cadaverous model were also performed. Corpses were placed in supine position, the hip in slight flexion (40°) and abduction (external rotation of 60°). A 16 G needle was used for the IPA puncture. Twelve CT angiography simulations were made. Of these 12 simulations, 9 revealed an isolated lesion of the popliteal vein and 2 isolated lesions of the tibial nerve. A lesion of the tibial nerve and the popliteal vein on the same simulation was once observed. Damage to the medial gastrocnemius muscle could not be avoided in each case. Ten punctures were performed on cadavers with technical success. There were 6 popliteal vein lesions, 3 tibial nerve lesions, and 1 case without lesion. In all cases, damage to the medial gastrocnemius muscle was seen. CONCLUSIONS: This medial approach was feasible and is accompanied by trauma of elements of the popliteal pedicle. Preoperative CT angiography could anticipate best site of puncture and potential access-related injury.

Outcomes and Predictors of Popliteal Artery Injury in Pediatric Trauma.

BACKGROUND: Popliteal artery injury (PAI) is a rare occurrence in pediatric patients with significant consequences. Delays in diagnosis lead to severe complications such as lifelong disability and limb loss. We sought to identify outcomes and clinical predictors of PAI in the pediatric trauma population. METHODS: The Pediatric Trauma Quality Improvement Program (2014-2016) was queried for patients ≤17 years old with PAI. Patient demographics and outcomes were characterized. A comparison of patients sustaining blunt versus penetrating PAI was performed. A multivariable logistic regression analysis was used to identify predictors of PAI. RESULTS: From 119,132 patients, 58 (<0.1%) sustained a PAI with 74.1% from blunt trauma. Most of the patients were male (75.9%) with a median age of 15 and median Injury Severity Score of 9. A majority of the patients were treated with open repair (62.1%) in comparison to endovascular repair (10.3%) and nonoperative management (36.2%). The rates of open and endovascular repair and nonoperative management were similar between blunt and penetrating PAI patients (P = not significant). Concomitant injuries included popliteal vein injury (PVI) (12.1%), posterior tibial nerve injury (3.4%), peroneal nerve injury (3.4%), and closed fracture/dislocation of the femur (22.4%), patella (25.9%), and tibia/fibula (29.3%). Overall complications included compartment syndrome (8.6%), below-knee amputation (6.9%), and above-knee amputation (3.4%). The overall mortality was 3.4%. Patients with PAI secondary to penetrating trauma had a higher rate of concomitant PVI (26.7% vs. 7%, P = 0.04) and posterior tibial nerve injury (13.3% vs. 0%, P = 0.02) but a lower rate of closed fracture/dislocation of the patella (0% vs. 34.9%, P = 0.008) and tibia/fibula (0% vs. 39.5%, P = 0.004) compared to patients with PAI from blunt trauma. Predictors for PAI included PVI (odds ratio [OR] 296.57, confidence interval [CI] = 59.21-1,485.47, P < 0.001), closed patella fracture/dislocation (OR 50.0, CI = 24.22-103.23, P < 0.001), open femur fracture/dislocation (OR 9.05, CI = 3.56-22.99, P < 0.001), closed tibia/fibula fracture/dislocation (OR 7.44, CI = 3.81-14.55, P < 0.001), and open tibia/fibula fracture/dislocation (OR 4.57, CI = 1.80-11.59, P < 0.001). PVI had the highest association with PAI in penetrating trauma (OR 84.62, CI = 13.22-541.70, P < 0.001) while closed patella fracture/dislocation had the highest association in blunt trauma (OR 52.01, CI = 24.50-110.31, P < 0.001). CONCLUSIONS: A higher index of suspicion should be present for PAI in pediatric trauma patients presenting with a closed patella fracture/dislocation after blunt trauma. PVI is most strongly associated with PAI in penetrating trauma. Prompt recognition of PAI is crucial as there is a greater than 10% amputation rate in the pediatric population.

Subtractive non-contrast-enhanced MRI of lower limb veins using multiple flow-dependent preparation strategies.

PURPOSE: To evaluate the performance of acceleration-dependent vascular anatomy for non-contrast-enhanced MR venography (ADVANCE-MRV) in femoral veins and to investigate whether venous signal uniformity can be improved by applying multiple acquisitions with different flow suppressions or multiple flow suppressions in 1 acquisition. METHODS: The ADVANCE-MRV method uses flow-sensitized modules to acquire a dark-artery image set and a dark-artery vein set, which are subsequently subtracted. Ten healthy volunteers were imaged using the ADVANCE-MRV sequence with improved venous suppression uniformity in the dark-artery vein images achieved by applying multiple flow suppressions in the same acquisition or by combining multiple images acquired with different flow suppressions. The performance of the improved technique was also evaluated in 13 patients with lower-limb deep venous thrombosis. RESULTS: Multiple-preparation and multiple-acquisition approaches all improved venous signal uniformity and reduced the signal void artifacts observed in the original ADVANCE-MRV images. The multiple-acquisition approaches achieved excellent blood signal uniformity and intensity, albeit at the cost of an increase in the total acquisition time. The double-preparation approach demonstrated good performance in all measurements, providing a good compromise between signal uniformity and acquisition time. The blood signal spatial variation and its variation using different gradient amplitudes were reduced by 20% and 29%. All patient images showed uniform and bright venous signal in nonoccluded sections of vein. CONCLUSION: The enhanced ADVANCE-MRV methods substantially improved signal uniformity in healthy volunteers and patients with known deep venous thrombosis. The double-preparation approach gave good-quality femoral vein images, providing improved venous signal uniformity without increasing acquisition time in comparison to the original sequence.

Deep vein thrombosis in a well-trained masters cyclist, is popliteal vein entrapment syndrome to blame?

Whilst athletes are the epitome of health, venous thromboembolisms (VTE) including deep vein thrombosis and pulmonary embolism have been demonstrated to occur in well-trained athletes. VTE is frequently misdiagnosed and poorly treated within this population, often resulting in career or life-threatening ramifications. Furthermore, VTE risk rises with increasing age (> 40 years), potentially affecting masters athletes. A 44-year-old well-trained male cyclist volunteered to participate in a research project investigating the influence of exercise on haemostasis in well-trained athletes. The cyclist presented with elevated D-Dimer levels both pre- (2251 ng/mL) and post-exercise (2653 ng/mL). The cyclist reported constant mild-pain in the left mid-calf region, with a cold tingling sensation in their left foot. Diagnosis of DVT was confirmed via a DVT squeeze test and Doppler ultrasound, with the clot located in the left popliteal vein. During the research project, the cyclist was exposed to numerous thrombogenic risk factors including travel, dehydration, prolonged sitting and exercise. The DVT in the popliteal vein may have resulted from repetitive movements associated with cycling. Additionally, hypertrophy of the gastrocnemius muscle may have impinged the vein. When diagnosing DVT within a cycling population, PVES should not be overlooked as a contributing factor.