Spatiotemporal dynamics of 2-methylisoborneol produced by filamentous cyanobacteria and associated driving factors in Lake Taihu, China.

The proliferation of filamentous cyanobacteria in lakes can result in the generation of odor-causing compounds, predominantly 2-methylisoborneol (2-MIB), which pose odor-related challenges. In an effort to elucidate the spatiotemporal dynamics of 2-MIB and related influencing factors in East Lake Taihu, monthly investigations were undertaken from April 2022 to March 2023. In addition to the monthly survey, a whole-lake survey was conducted during the high-temperature period from July to September. The monthly survey revealed a distinct unimodal fluctuation in the concentration of 2-MIB in East Lake Taihu, with an average concentration at 297.0 ng/L during the high-temperature period. During the high-temperature period, the filamentous cyanobacterial communities detected in East Lake Taihu consisted primarily of species belonging to genera Leptolyngbya, Oscillatoria, Planktothricoides, and Pseudanabaena. However, no significant correlations were found between their densities and 2-MIB concentration. In addition, the mic gene was predominantly detected in genera Pseudanabaena and Planktothricoides, with the latter being the primary contributor to 2-MIB production. Furthermore, a succession of cyanobacteria capable of producing 2-MIB was detected, with water temperature and radiation intensity being identified as the primary driving factors. The temporal variation of 2-MIB concentration within East Lake Taihu during the whole year was primarily modulated by factors such as water temperature, water transparency, dissolved oxygen, and chlorophyll-a. During the high-temperature period, the 2-MIB concentration in the alga-dominated zone of East Lake Taihu was approximately 1.7 times greater than that in the macrophyte-dominated zone, with nutrient and transparency being identified as the main influencing factors. Consequently, our findings are of great significance for monitoring the sources and variation of 2-MIB in shallow lakes, providing a scientific foundation and theoretical guidance for odor management.

Visible Light-Responsive Crystalline B←N Host Adducts with Solvent-Induced Allosteric Effect for Guest Release.

Photo-responsive organic crystals, capable of converting light energy into chemical energy to initiate conformational transitions, present an emerging strategy for developing lightweight and versatile smart materials. However, visible light-triggered tailored guests capture and release behaviors in all-organic solids are rarely reported. Here, we introduce a photoreactive crystalline boron-nitrogen (B←N) host adduct with the ability to undergo [2+2] photocycloaddition upon 447 nm light exposure. This process facilitates single-crystal-to-single-crystal (SCSC) photodimerization in the mother liquor, maintaining the original B←N host structure. Weakened intermolecular interactions within the photodimer host contribute to fast guest release in air under irradiation. Furthermore, the dynamic B←N bonds enable reversible transformations between organic host adducts and adduct cocrystals under the solvent-induced allosteric effect. As a result, four B←N host adduct crystals containing individual alkane guest are easily obtained and exhibited the ability of photo-controlled alkane release. Therefore, the integration of photo reactivity and structural transformation within B←N host adduct enables customized capture and release of guest molecules.

Tandem Solid-Solution Post-Synthetic Modification of Porous Molecular Crystals for In-situ Generation of Fluorophores.

Conventional synthetic methods of organic luminescent molecules often involve labor-intensive solution-phase organic synthesis, which violate the principles of atom-economic transformation. Post-synthetic modification (PSM) offers a promising alternative, allowing direct transformation from one fluorophore to another. Although PSM is commonly implemented in extended frameworks, its application in porous molecular crystals remains challenging. Herein, we focus on utilizing porous molecular crystals, specifically tetraphenylethylene-cored frameworks, as versatile platforms for tandem PSM reactions to customize organic fluorophores. The tailored skeleton design ensures both the formation of porous structures and the occurrence of tandem solid-solution reactions while maintaining the solid state of reactants and products in each step. The inherent non-covalent bonding nature of the frameworks facilitates processing and characterization, offering unparalleled advantages for porous networks. The accompanying solid-state fluorescence transition from green to blue and then to green (or yellow) enables real-time monitoring of tandem reactions and provides intuitive mechanistic insights. This phenomenon is exploited for the facile construction of a dynamic information encryption system using fluorescent quick response codes.

Establishment of an acute arterial mesenteric ischaemia model in canines with an endovascular approach.

Purpose: This study aimed to evaluate the feasibility of establishing an arterial acute mesenteric ischemia (AMI) model in canines using transcatheter autologous thrombus administration. Materials and methods: Ten canines were divided into the experimental group (Group A, n = 5) and the sham group (Group B, n = 5). The canines in Group A received thrombus administration to the superior mesenteric artery (SMA) through a guiding catheter, while the canines in Group B received normal saline administration. Blood samples were collected and tested at baseline and 2 h after modelling. Canines in Group A underwent manual thromboaspiration after blood and intestine samples were collected. Ischaemic grades of intestinal mucosa were evaluated under light microscopes. Results: The AMI models were successfully conducted in all canines without procedure-related vessel injury or death. At the 2-h follow-up, the high-sensitivity C-reactive protein and D-dimer in Group A were significantly higher than in Group B (5.72 ± 1.8 mg/L vs. 2.82 ± 1.5 mg/L, p = 0.024; 2.25 ± 0.8 µg/mL vs. 0.27 ± 0.10 µg/mL, p = 0.005; respectively). The mean histopathologic intestinal ischaemic grade in Group A was significantly higher than in Group B (2.4 ± 0.5 vs. 0.8 ± 0.4, p < 0.001). After a median of 2 times of thromboaspiration, 80% (4/5) of the canines achieved complete SMA revascularisation. Conclusion: This experimental study demonstrated that establishing an arterial model in canines using endovascular approaches was feasible. The present model may play an important role in the investigation of endovascular techniques in the treatment of arterial AMI.

Endovascular revascularization vs open surgical revascularization as the first strategy for arterial acute mesenteric ischemia: A systematic review and meta-analysis.

OBJECTIVE: This paired meta-analysis aimed to compare the mortality and morbidity of endovascular revascularization (EVR) and open surgical revascularization (OSR) as the first strategy for arterial acute mesenteric ischemia (AMI). METHODS: This systematic review and meta-analysis were performed in accordance with the PRISMA statement. A systematic search strategy was performed to identify eligible studies using the following databases: PubMed, Embase, and Cochrane Library database from inception to December 31, 2023, with restriction to the English language. The end search date was January 2, 2024. The primary outcome was short-term mortality. Secondary outcomes included bowel resection, second-look laparotomy, and short bowel syndrome. The counterenhanced funnel plot and the Peters' test were used to assess bias. Outcomes were reported as odds ratio (OR) with a 95% confidence interval (CI) using the Mantel-Haenszel method. The GRADE classification was used to estimate the certainty of evidence. RESULTS: A total of 11 studies (1141 patients) comparing EVR vs OSR for arterial AMI were identified and analyzed. The mean patient age was 61.9 to 73.6 years and 45.1% of the patients were male. Compared with OSR, EVR as the first treatment may not decrease short-term mortality (OR, 0.79; 95% CI, 0.50-1.25; P = .31; very low certainty) and second-look laparotomy (OR, 1.00; 95% CI, 0.30-3.36; P = .99; very low certainty). However, EVR may be associated with decreased bowel resection (OR, 0.42; 95% CI, 0.20-0.88; P = .022; very low certainty) and short bowel syndrome (OR, 0.39; 95% CI, 0.21-0.75; P = .005; very low certainty). The metaregression revealed that the mortality regarding EVR vs OSR was not impacted significantly by thrombotic etiology (-0.002; 95% CI, -0.027 to 0.022; P = .85), whereas it was impacted significantly by publication year (0.076; 95% CI, 0.069-0.145; P = .031). CONCLUSIONS: Compared with OSR, EVR as the first treatment for arterial AMI may not decrease short-term mortality or second-look laparotomy. Future multicenter randomized controlled trials are needed urgently to confirm these results.

Lost Circulation Prediction Method Based on an Improved Fruit Fly Algorithm for Support Vector Machine Optimization.

Lost circulation events during drilling operations are known for their abruptness and are difficult to control. Traditional diagnostic methods rely on qualitative indicators, such as mud pit volume changes or anomalous logging curve patterns. However, these methods are subjective and rely heavily on empirical knowledge, resulting in delayed or inaccurate predictions. To address this problem, there is an urgent need to develop efficient methods for a timely and accurate lost circulation prediction. In this study, a novel approach is proposed by combining principal component analysis (PCA) and empirical analysis to reduce the dimensionality of the model data. This dimensionality reduction helps to streamline the analysis process and improve prediction accuracy. The predictive model also incorporates an improved fruit fly optimization algorithm (IFOA) in conjunction with support vector machine (SVM) techniques. The actual instances of lost circulation serve as the evaluation criteria for this integrated method. To overcome the challenges associated with irregular population distribution within randomly generated individuals, a tent map strategy is introduced to ensure a more balanced and representative sample. In addition, the model addresses issues such as premature convergence and slow optimization rates by employing a sine-cosine search strategy. This strategy helps to achieve optimal results and speeds up the prediction process. The improved prediction model demonstrates exceptional performance, achieving accuracy, precision, recall, and F1 scores of 96.8, 97, 96, and 96%, respectively. These results indicate that the IFOA-SVM approach achieves the highest accuracy with a reduced number of iterations, proving to be an efficient and fast method for predicting the lost circulation events. Implementation of this methodology in drilling operations can lead to improved efficiency, reliability, and overall performance.

Association Between Inferior Vena Cava-Involved Thrombosis, Severe Iliac Vein Stenosis, and Proximal Pulmonary Embolism in Patients With Deep Vein Thrombosis.

To investigate the possible risk factors for proximal pulmonary embolism (PE) in patients with lower extremity deep vein thrombosis (LEDVT). A single-center, retrospective cohort study was conducted. Consecutive patients diagnosed with unilateral LEDVT and confirmed PE by computed tomography (CT) pulmonary angiography and indirect CT venography between September 2015 and January 2022 were included. Patient demographics, presentation of LEDVT, laboratory examination, thrombus characteristics, comorbidities and risk factors for LEDVT, and imaging findings were analyzed to determine the univariable and multivariable associations. The associations between thrombus location, stenosis, and proximal PE were assessed using a stratified analysis. A total of 115 eligible patients (60.08 ± 15.18 years, 59.1% male) were included. Of these patients, 40 (34.8%) were in the proximal PE group (proximal thrombus involved main or lobar pulmonary artery), and 75 (65.2%) were in the distal PE group (without main and labor pulmonary artery involvement). The univariable analysis showed that onset time of LEDVT symptoms ≤ 7 days (P = .041), inferior vena cava (IVC) involvement (P = .035), and severe iliac vein stenosis (IVS) (stenosis ratio > 61.3%) (P = .010) were associated with the occurrence of proximal PE. Further multivariant analysis showed that IVC involvement was associated with an increased odds of proximal PE (OR: 4.45, 95% CI: 1.083 - 18.248, P = .038), whereas severe IVS (stenosis ratio > 61.3%) was associated with a decreased odds of proximal PE (OR: 0.294, 95% CI: 0.110-0.783, P = .014). Among patients with unilateral LEDVT, IVC involvement increased the risk of proximal PE; patients with severe IVS (stenosis ratio > 61.3%) had a lower risk of developing proximal PE compared with distal PE; and severe IVS seemed to be a protective factor for proximal PE.

How to create a nervous system aneurysm model in canines? ligation of the lingual artery is a simple and effective method.

Background: The purpose of this research was to establish a safe, effective, and simple nervous system aneurysm model. This method could quickly and stably establish an exact canine tongue aneurysm model. This paper summarizes the technique and key points of the method. Methods: Under the condition of anesthesia by inhaling isoflurane with a mask, we punctured the femoral artery of the canine, and the tip of the catheter was placed in the common carotid artery for intracranial arteriography. The positions of the lingual artery, external carotid artery, and internal carotid artery were identified. Then, the skin near the mandible was cut according to the positioning and separated layer by layer until the bifurcation of the lingual artery and external carotid artery was exposed. The lingual artery were then sutured with 2-0 silk sutures approximately 3 mm from the external carotid/lingual artery bifurcation. The final angiographic review showed that the aneurysm model was successfully established. Results: The lingual artery aneurysm was successfully established in all 8 canines. All canines obtained a stable model of nervous system aneurysm and confirmed by DSA angiography. Conclusion: We have established a safe, effective, stable and simple method to establish a canine nervous system aneurysm model with controllable size. In addition, this method has the advantages of no arteriotomy, less trauma, constant anatomical location, and low risk of stroke.

Impact of Common Iliac Vein Compression on the Incidence of Pulmonary Embolism in Patients with Acute Deep Vein Thrombosis.

OBJECTIVE: This study aimed to investigate the association between common iliac vein (CIV) compression and pulmonary embolism (PE) in lower extremity deep vein thrombosis (DVT). METHODS: This was a single centre retrospective study. Between January 2016 and December 2021, DVT patients with enhanced computed tomography of the iliac vein and pulmonary artery were included. Patient demographics, comorbidities, risk factors, and degree of CIV compression were collected and analysed. Logistic regression was performed to evaluate the odds ratio (OR) with a 95% confidence interval (CI) of PE in relation to compression severity groups. The association between PE and compression degree was evaluated with restricted cubic splines (RCS) based on an adjusted logistic regression model. RESULTS: Two hundred and twenty-six DVT patients (left side, n = 153; right side, n = 73) were included. Univariable analyses suggested that symptomatic or asymptomatic PE (54.4%, 123/226) was more common in men (p = .048) and right side DVT (p = .046) patients. Compared with no CIV compression, multivariable analyses suggested that mild compression did not statistically significantly reduce the PE risk, whereas moderate (adjusted OR 0.36; 95% CI 0.15 - 0.88; p = .025) and severe (adjusted OR 0.18; 95% CI 0.06 - 0.54; p = .002) compression statistically significantly reduced the risk. RCS showed that a smaller minimum diameter or greater compression percentage was correlated with continuously decreasing PE risk at a minimum diameter of < 6.77 mm or compression > 42.9%. CONCLUSION: PE is more common in men and right side DVT patients. An increasing severity of CIV compression is consistently associated with a decreasing risk of PE when the minimum diameter is < 6.77 mm or the compression is > 42.9%, indicating that it is a protective factor against PE.

Silent Pulmonary Embolism in Deep Vein Thrombosis: Relationship and Risk Factors.

PURPOSE: This study aimed to evaluate risk factors for silent pulmonary embolism (PE) in symptomatic deep vein thrombosis (DVT) and investigate the relationship between DVT and silent PE. METHODS: This was a single-centre, retrospective cohort study. Between 5 January 2015 and 31 December 2021, consecutive patients with symptomatic DVT received CT pulmonary angiography and CT venography were analyzed. Patient demographics, comorbidities, risk factors, and image findings were analyzed. The group differences were compared using a Chi-square test, Fisher's exact test, independent t test, or Mann-Whitney U test. Multivariant regression was used to determine predictive factors for silent PE. RESULTS: A total of 355 patients (mean age, 60.5 ± 16.6 years) were included. The incidence of silent PE was 43.1%. The main or lobar pulmonary arteries were affected in 53.6% of patients, which is more often found in iliofemoral DVTs (56.6% vs 26.7%, p = .027). The multivariant analysis showed male patients (p = .042; OR 1.59; 95% CI, 1.02-2.50), inferior vena cava involvement (p = .043; OR 1.81; 95% CI, 1.02-3.20) and D-dimer value > 3.82 µg/ml (p < .001; OR 2.32; 95% CI, 1.43-3.77) were risk factors for silent PE. Unilateral DVT patients with ipsilateral iliac vein compression had a lower incidence of silent PE (28.8% vs 52.9%, p < .001). CONCLUSION: Iliofemoral DVT was associated with a more proximal PE. The male patients, inferior vena cava involvement, and D-dimer > 3.82 µg/ml were risk factors for silent PE. Ipsilateral iliac vein compression reduced the incidence of silent PE.

Safety and Efficacy of Endovascular Treatment on Pregnancy-Related Iliofemoral Deep Vein Thrombosis.

Objective: This study investigates the safety and efficacy of endovascular treatments on pregnancy-related iliofemoral deep vein thrombosis (DVT). Methods: We retrospectively reviewed data of 46 patients who had symptomatic pregnancy-related iliofemoral DVT and underwent endovascular treatment. The patients treated with catheter-directed thrombolysis (CDT) were classified as the CDT group. In contrast, those treated with CDT combined with pharmacomechanical thrombectomy (PMT) or angioplasty/stenting were classified as the pharmacomechanical catheter-directed thrombolysis (PCDT) group. Results: Based on the immediate post-operative clot burden reduction rate analysis of 46 patients: 22 cases were completely dissolved (lysis grades III), 12 were partially dissolved (lysis grades II), and 12 failed (lysis grades I). There was a statistically significant difference in the rate of clot burden reduction between the CDT group (n = 19) and the PCDT group (n = 27) (p = 0.001). There was no statistically significant difference in the number of bleeding events between the two groups (p = 0.989). At 24 months, cumulative venous patency in the CDT group was 50.0%, compared to 78.2% in the PCDT group. Furthermore, there was a statistically significant difference in Villalta score (p = 0.001) and venous severity scoring (VCSS score) (p = 0.005) between the two groups. Conclusions: CDT treatment combined with PMT or angioplasty/stenting is comparatively safe and effective for pregnant-related DVT patients. PCDT outperforms CDT in terms of immediate efficacy and reduces the incidence of post-thrombotic syndrome with better midterm outcomes.

Solitaire™ Stent Thrombectomy System in the Treatment of Acute Lower-Limb Ischemia: Comparisons in Safety and Effectiveness with Conventional Catheter-Directed Thrombolysis Therapy.

Objective: The study aimed to investigate the safety and efficacy of the Solitaire™ AB Stent System (ev3 Inc., Plymouth, MN, USA) for the treatment of acute lower extremity ischemia (ALLI) compared with conventional catheter-directed thrombolytic therapy. Methods: Retrospective analysis of patients with ALLI treated in the Department of Interventional Radiology at the First Hospital of Nanjing from January 2017 to April 2020 divided into a conventional (CDT) group (n = 106) and a percutaneous mechanical thrombectomy (PMT) group (n = 55) according to the procedure. PMT was performed using the Solitaire™ AB stent system. The combined clinical outcomes of mortality, major amputation, recurrent ischemia, and major morbidity were compared between the two groups. Results: Of the 161 patients, 128 (79.5%) did not have a composite clinical outcome after 12 months of follow-up, namely, 78 CDT patients and 50 PMT patients, with significant differences in composite clinical outcome (26.4% vs. 9.1%, P = 0.010) and mortality (19.8% vs. 7.3%, P = 0.037) between them. Thrombolytic drug dose (19.34 ± 5.93 vs. 13.55 ± 6.54 mg, P < 0.001) and length of hospital stay (8.29 ± 3.91 vs. 5.49 ± 1.18 days, P = 0.003) were significantly lower in the PMT group. Conclusion: PMT with the Solitaire™ AB Stent System is safer and more effective in treating patients with Rutherford stage I-IIB ALLI, with the advantage of rapid opening of obstructed vessels, shorter thrombolysis time, reduced thrombolytic dose, and improved blood flow to the infrapopliteal vessels.

Solvent-Triggered Fast and Visible Switching between Cage- and Channel-Type Hydrogen-Bonded Organic Frameworks.

The inherent weak bonding nature of hydrogen-bonded organic frameworks (HOFs) performs like a double-edged sword in that it endows HOFs with superiority in processability and dynamicity but deactivates its on-demand controllability in the crystalline phase. Herein, based on the synergy of dynamic H-bonding interactions and the tailored low solubility in common organic solvents, reversible and fast topological transitions between cage- and channel-type HOFs were achieved upon immersing in the solution state. The aggregation-induced-emission character of the tecton facilitates the visualization of the elusive initial transition process with high sensitivity. In addition, the visible transition from cage- and channel-type HOFs to thermally stable crystalline phases is also achieved under thermal induction.

Multiple yet switchable hydrogen-bonded organic frameworks with white-light emission.

The development of new strategies to construct on-demand porous lattice frameworks from simple motifs is desirable. However, mitigating complexity while combing multiplicity and reversibility in the porous architectures is a challenging task. Herein, based on the synergy of dynamic intermolecular interactions and flexible molecular conformation of a simple cyano-modified tetraphenylethylene tecton, eleven kinetic-stable hydrogen-bonded organic frameworks (HOFs) with various shapes and two thermo-stable non-porous structures with rare perpendicular conformation are obtained. Multimode reversible structural transformations along with visible fluorescence output between porous and non-porous or between different porous forms is realized under different external stimuli. Furthermore, the collaborative of flexible framework and soft long-chain guests facilitate the relaxation from intrinsic blue emission to yellow emission in the excited state, which represents a strategy for generating white-light emission. The dynamic intermolecular interactions, facilitated by flexible molecular conformation and soft guests, diversifies the strategies of construction of versatile smart molecular frameworks.

Risk factors and a predictive model for nonfilter-associated inferior vena cava thrombosis in patients with lower extremity deep vein thrombosis.

Objective: Nonfilter-associated inferior vena cava thrombosis (IVCT) is an under-recognized but severe state of venous thromboembolism. The aims of this study were to investigate risk factors and develop a prediction model based on clinical data and imaging findings to evaluate the probability of IVCT in patients with lower extremity deep vein thrombosis (LEDVT). Methods: A single-center retrospective cohort study was conducted. We analyzed the clinical data and multimodal imaging findings of consecutive patients with confirmed LEDVT between February 2016 and January 2022. The demographics, presentation of LEDVT, laboratory examination, thrombus characteristics, comorbidities and risk factors for LEDVT, and imaging findings were analyzed using an independent t-test, Chi-square test, Fisher's exact test, and regression analysis to determine the univariable and multivariable associations and to establish a predictive model to assess the probability of IVCT. Results: A total of 267 eligible patients were included, of whom 40 were in the IVCT group and 227 were in the non-IVCT group. The incidence of nonfilter-associated IVCT was 15.0% (40/267). Age < 63.5 years [odds ratio (OR) 2.54; 95% confidence interval (CI), 1.10-5.85, p = 0.029], male sex (OR 2.82; 95% CI, 1.19-6.72, p = 0.019), proximal DVT (OR 8.21; 95% CI, 1.01-66.76, p = 0.049), bilateral DVT (OR 7.30; 95% CI, 3.28-16.21, p < 0.001), and D-dimer >4.72 µg/ml (OR 4.64; 95% CI, 1.80-11.72, p = 0.001) were risk factors for IVCT's occurrence. Then, we established a prediction model based on these risk factors. The diagnostic efficiency [area under the curve (AUC) of receiver operating characteristic (ROC) curve was 0.858] for predicting IVCT was superior to that of isolated risk factors, including age < 63.5 years (AUC of ROC curve was 0.624) or D-dimer >4.72 µg/ml (AUC of ROC curve was 0.656). Conclusion: Age < 63.5 years, male sex, proximal LEDVT, bilateral LEDVT and D-dimer >4.72 µg/ml were risk factors. The diagnostic efficiency of the predictive model for predicting IVCT was superior to that of a single risk factor alone. It may be used for predicting the probability of nonfilter-associated IVCT in patients with LEDVT.

The association between iliac vein compression degree and characteristics of first diagnosed left lower extremity deep vein thrombosis.

Objective: This study aimed to investigate the association between the left common iliac vein (CIV) compression degree and characteristics of first diagnosed left lower extremity deep vein thrombosis (DVT). Patients and methods: This was a single-center retrospective observational study. Between January 2015 and June 2022, first diagnosed left lower extremity DVT patients with enhanced computed tomography of lower extremities were included. Patient demographics, comorbidities, risk factors, DVT characteristics, and CIV compression degree were collected and analyzed. Logistic regressions were performed to evaluate the odds ratio (OR) with a 95% confidence interval (CI) of iliofemoral or mixed DVT vs. compression percentage. The association between compression percentage and iliofemoral or mixed DVT was evaluated on a continuous scale with restricted cubic splines (RCS). The association between compression percentage and thrombus burden was evaluated using the Spearman test. Results: A total of 196 (mean age, 61.8 ± 16.1 years; 86 males) patients were included. The median CIV compression percentage in iliofemoral or mixed DVT patients was significantly greater than in non-iliofemoral or non-mixed DVT, respectively (64.4 vs. 46.6%, p < 0.001; 67.8 vs. 54.8%, p = 0.004). CIV compression >50% was associated with significantly increased morbidity of iliofemoral DVT (adjusted OR, 2.96; 95% CI, 1.58-5.52; p = 0.001) or mixed DVT (adjusted OR, 2.39; 95% CI, 1.19-4.81; p = 0.014). RCS showed that a greater compression percentage was associated with a continuously increased OR of iliofemoral DVT (overall p = 0.003, non-linear p = 0.577) or mixed DVT (overall p = 0.020, non-linear p = 0.771). CIV compression percentage had a positive correlation with thrombus burden (rs = 0.284, p < 0.001). Conclusion: A greater left CIV compression percentage may be associated with increasing likelihood of more proximal location and severe clot extent in first diagnosed left lower extremity DVT.