Incidence and risk factors for deep vein thrombosis (DVT) and pulmonary embolism (PE) in acute necrotizing pancreatitis (ANP) - A single center experience.

INTRODUCTION: Inflammation-induced dysregulation of the coagulation cascade and vascular stasis in hospitalized patients with acute necrotizing pancreatitis (ANP) serve as a milieu for venous thromboembolism (VTE). Deep vein thrombosis (DVT) and pulmonary embolism (PE) are often underrecognized. We evaluated the incidence and risk factors for VTE in a cohort of patients with ANP. METHODS: All adult patients with ANP at our center between 2009 and 2022 were followed for three months after index hospitalization and categorized into cases and controls based on development of VTE. Demographic, clinical, and radiologic characteristics during admission were compared. A multivariable analysis was done to identify independent predictors for VTE. A p value of <0.05 was taken as significant. RESULTS: Among 643 ANP patients, 512 [males-350, median age-52 years] were eligible for inclusion. VTE developed in 64 (12.5 %) patients - 28 DVT (5 %), 22 PE (4 %) and both in 14 (3 %) after a median 16 days from the diagnosis of ANP. Significant independent predictors for VTE on multivariable analysis were age ≥60 years (OR 1.91; 95 % CI 1.04-3.53), peri-pancreatic extent of necrosis (OR 7.61; 95 % CI 3.94-14.70), infected necrosis (OR 2.26; 95 % CI 1.13-4.50) and total length of stay ≥14 days (OR 4.08; 95 % CI 1.75-9.50). CONCLUSIONS: The overall incidence of VTE in our cohort of patients with ANP was 12.5 %, which was usually diagnosed within one month of hospitalization. High-risk patients can be stratified based on clinical and imaging characteristics and may benefit from intensive DVT screening and prophylaxis during hospitalization and following discharge.

Impact of COVID-19 in the incidence of venous thromboembolism (VTE) and clinical outcomes in cancer patients: a cohort study.

PURPOSE: To determine the incidence of VTE and clinical outcomes in a cohort of cancer patients and COVID-19 infection, and to establish possible predictive factors of VTE. METHODS/PATIENTS: A single-center retrospective cohort study was performed to determine the incidence of VTE and mortality in 118 cancer patients with SARS-CoV-2 infection from March to August 2020. We calculated individual Khorana Risk and CATS-MICA scores in order to evaluate their utility to identify risk of VTE or death. Continuous variables were compared using Wilcoxon or Student's T test, and categorical variables were compared using the Chi-Square or Fisher's exact text among patients with and without VTE. A Log-Rank test was performed to detect mortality differences between the groups. RESULTS: A total of 118 patients were included. VTE global incidence was 4.2% (n = 5), and mortality 25.4% (n = 30). Obesity (p = 0.05), recent chemotherapy (p = 0.049) and use of steroids (p = 0.006) were related to higher risk of VTE in the univariate analysis, although they were not confirmed in the multivariate analysis as independent risk factors. Statistically significant differences in all-cause, COVID-19-related and cancer-related mortality according to the Khorana risk score (KRS) were observed. CATS-MICA score (CMS) also showed statistically significant differences in mortality between low- and high-risk patients. Prediction of risk of VTE development with these scores showed a tendency towards significance. CONCLUSIONS: In this cohort, VTE incidence was similar to previously reported in the general population with SARS-CoV-2 infection. KRS was associated with overall and specific-cause mortality, and might be a useful prognostic tool in this setting.

A narrative review on tip navigation and tip location of central venous access devices in the neonate: Intracavitary ECG or real time ultrasound?

The proper location of the tip of a central venous access device plays a crucial role in minimizing the risks potentially associated with its use. Recent guidelines strongly recommend preferring real-time, intra-procedural methods of tip location since they are more accurate, more reliable and more cost-effective than post-procedural methods. Intracavitary electrocardiography and real time ultrasound can both be applied in the neonatal setting, but they offer different advantages or disadvantages depending on the type of central venous access device. Reviewing the evidence currently available about the use of these two methods in neonates, in terms of applicability, feasibility and accuracy, it can be concluded that (a) real time ultrasound is the only acceptable methodology for tip navigation for any central venous access device in neonates, (b) intracavitary electrocardiography is the preferred method of tip location for central catheters inserted by ultrasound-guided cannulation of the internal jugular vein or the brachiocephalic vein, and (c) real time ultrasound is the preferred method of tip location for umbilical venous catheters, epicutaneo-cava catheters, and central catheters inserted by ultrasound-guided cannulation of the common femoral vein.

Central venous catheter-related thrombosis in patients with amyotrophic lateral sclerosis.

BACKGROUND: Central venous catheterization may be required in patients with amyotrophic lateral sclerosis (ALS) for parenteral nutrition, antibiotic treatment, or blood sampling. Different venous access devices can be taken into consideration-centrally inserted central catheters (CICC), peripherally inserted central catheters (PICC), and femorally inserted central catheters (FICCs)-depending on the clinical conditions of the patients. Regardless of the type of access, the presence of paraplegia or tetraplegia is commonly considered a risk factor for catheter-related thrombosis (CRT). METHOD: This retrospective study analyzes the rate of CRT and other non-infectious complications associated with central venous access in a cohort of 115 patients with paraplegia or tetraplegia, most of them affected by ALS (n = 109). RESULTS: In a period of 34 months, from January 2021 to October 2023, we inserted 75 FICCs, 29 CICCs, and 11 PICCs. PICCs were inserted only in patients with preserved motility of the upper limbs. All devices were inserted by trained operators adopting appropriate insertion bundles. We had no immediate or early complication. Though antithrombotic prophylaxis was adopted only in 61.7% of patients, we had no symptomatic CRT. Other non-infectious complications were infrequent (4 out of 115 patients). CONCLUSION: These results suggest (a) that the presence of paraplegia or tetraplegia is not necessarily associated with an increased risk of CRT, (b) that the adoption of well-designed insertion bundles plays a key role in minimizing non-infectious complications, and (c) that the insertion of FICCs by direct cannulation of the superficial femoral vein at mid-thigh in paraplegic/tetraplegic patients may have the same advantages which have been described in the general population.

Oxygen venous saturation is associated with subclinical myocardial systolic dysfunction in patients with end-stage renal disease undergoing hemodialysis.

Introduction: The aim of this prospective study was to evaluate the impact of hemodialysis (HD) on myocardial injury, of both right and left ventricle function as well as their association with venous oxygen saturation (ScvO2) alterations. Material and methods: We included in the study stable consecutive patients with end-stage renal disease (ESRD) undergoing regular HD. Right and left ventricular speckle-tracking echocardiographies were performed in all patients. The examination calculates the global systolic longitudinal strain (GLS). Blood samples were obtained from the central vein in order to measure the O2 saturation (ScvO2) levels prior and post HD. High sensitive troponin (HST) was also measured in all patients before and after HD. Results: Thirty seven patients were evaluated. We found that both mean ScvO2 and left ventricle GLS (LV GLS) were deteriorated after the dialysis session: 76.47 ±1.98 to 71.54 ±5.10, p < 0.05 and -17.73 ±3.44 to -14.21 ±3.44%, p < 0.01, respectively. HST levels were increased at the end of hemodialysis, 22.45 ±13.26 to 106.78 ±146.19 pg/ml, p < 0.01. A significant correlation was also found between the decrease of LV GLS with the ScvO2 reduction, p = 0.001, as well as with the increase of the HST levels, p = 0.001. Conclusions: Our data demonstrate that there is a significant worsening of the GLS of the left ventricle at the end of the dialysis, which is strongly associated with the concomitant deterioration of ScvO2. The may be a reliable index of circulatory stress indicating a subclinical myocardial dysfunction during HD.

Accessory Head of Sternocleidomastoid Muscle in Indian Cadavers: A Report of Three Cases.

During dissection sessions for undergraduate students, the unilateral accessory clavicular head of the sternocleidomastoid muscle was observed in three cadavers. These accessory heads extended from the middle third of the clavicle and joined the sternocleidomastoid muscle in the middle third. The variations in the sternocleidomastoid muscle may be attributed to abnormal mesodermal splitting or fusion failure during the development of the post-sixth branchial arch. Anomalies of the sternocleidomastoid may be misdiagnosed as cervical dystonia, fibromatosis colli, or muscular spasm. In rare cases, an accessory head could result in torticollis in adults. These anomalies warrant particular attention during interventional procedures conducted by anesthesiologists. The internal jugular vein is accessed at the lesser supraclavicular fossa for cannulation during central venous access and temporary hemodialysis. Variations in its anatomy can pose challenges during these procedures. Moreover, the clavicular head may be utilized for muscle flaps in the upper neck and occipital regions.

Testosterone Therapy as an Isolated Risk Factor for Venous Thrombosis: A Case Report.

Healthcare providers in the emergency department (ED) diagnose and treat venous thrombus embolism (VTE). Current VTE clinical decision tools specifically mention estrogen but do not include the use of testosterone replacement therapy (TRT). A male in the early third decade of life presented to the ED with complaints of left calf pain and subjective swelling for one week. The patient was low risk using VTE scoring tools. The patient had multiple occlusive VTE on lower-extremity ultrasound and extensive central, bilateral segmental, and subsegmental pulmonary emboli. He was admitted to the hospital and placed on a heparin drip. TRT may be seen in clinical practice in both male and female patients. This bodes the question of whether TRT should be added to the risk analysis tools used to evaluate and predict the risk for VTE. There have been conflicting reports in research, with more recent studies indicating the risk associated with TRT. This case study demonstrates the risk of VTE with TRT. Further investigation is needed to determine if there is a correlation between VTE and TRT. Clinical decision tools should be updated to include TRT accordingly.

Reliability, usability, and efficiency of video versus print instructions to teach parents a procedural task: A cross-sectional study.

OBJECTIVE: To compare the reliability, usability, and efficiency of video versus print instructions to teach parents a procedural measurement task. We hypothesized that videos would outperform print in all outcomes. STUDY DESIGN: This cross-sectional study included parents/caregivers of children aged 0-18 years with deep vein thrombosis attending the Thrombosis Clinic at The Hospital for Sick Children for post-thrombotic syndrome (PTS) assessment. Participants were randomly assigned to three instruction types: (i) video, which followed the technique used by clinicians; (ii) long pamphlet, which also followed the clinicians' technique; and (iii) short pamphlet, which explained a simplified technique. After measuring their children's arms or legs using the randomly assigned material, participants completed a usability questionnaire. The reliability of the instructions was estimated by comparing parents/caregivers versus clinicians' measurements using the intraclass correlation coefficient (ICC). Reliability, usability, and efficiency (time to task completion) were compared among the three instruction types. RESULTS: In total, 92 participants were randomized to video (n = 31), long pamphlet (n = 31), and short pamphlet (n = 30). While the video had the highest usability, the short pamphlet was the most reliable and efficient. ICCs were .17 (95% confidence interval [CI]: .00-.39) for the video, .53 (95% CI: .30-.72) for the long pamphlet, and .70 (95% CI: .50-.81) for the short pamphlet. CONCLUSION: Although the video had higher usability, the short/simplified print instruction was more reliable and efficient. However, the reliability of the short pamphlet was only moderate/good, suggesting that whenever possible, measurements should still be obtained by trained clinicians.

Suture closure AFtEr large bore vein access (SAFE-VEIN): A randomized, prospective study of the efficacy and safety of venous closure device.

BACKGROUND: Perclose ProGlide (PPG) Suture-Mediated Closure System™ is safe and can reduce time to hemostasis following procedures requiring arterial access. AIMS: We aimed to compare PPG to figure of 8 suture in patients who underwent interventional catheter procedures requiring large bore venous access (LBVA) (≥13 French). METHODS: In this physician-initiated, randomized, single-center study [clinicaltrials.gov ID: NCT04632641], single-stick venous access was obtained under ultrasound guidance. Eligible patients were randomized 1:1, and 100 subjects received allocated treatment to either PPG (n = 47) or figure of 8 suture (n = 53). No femoral arterial access was used in any patient. Primary outcomes were time to achieve hemostasis (TTH) and time to ambulation (TTA). Secondary outcomes were time to discharge (TTD) and vascular-related complications and mortality. Wilcoxon rank-sum test was used to compare TTH, TTA, and TTD. RESULTS: TTH (minutes) was significantly lower in PPG versus figure of 8 suture [median, (Q1, Q3)] [7 (2,10) vs. 11 (10,15) respectively, p < 0.001]. TTA (minutes) was significantly lower in PPG compared to figure of 8 suture [322 (246,452) vs. 403 (353, 633) respectively, p = 0.005]. TTD (minutes) was not significantly different between the PPG and figure of 8 suture arms [1257 (1081, 1544) vs. 1338 (1171,1435), p = 0.650]. There was no difference in minor bleeding or access site hematomas between both arms. No other vascular complications or mortality were reported. CONCLUSION: PPG use had lower TTH and TTA than figure of 8 suture in a population of patients receiving LBVA procedures. This may encourage same-day discharge in these patients.

Cerebral venous sinus thrombosis and SCN1A, a novel association?

BACKGROUND: Cerebral venous sinus thrombosis (CVST) is a rare cause of stroke. Acquired and inherited prothrombotic conditions are the most common risk factors for CVST. Sometimes, an etiology is not found. Wide utilization of next generation sequencing technologies in clinical practice may lead to identification of risk factors other than those classically associated with CVST. METHOD AND RESULTS: This retrospective clinical-laboratory observational study has a reference patient who presented with CVST as an adolescent. Work up for prothrombotic conditions showed high homocysteine level secondary to homozygosity for a common polymorphism, c.677 C > T in the methylenetetrahydrofolate reductase (MTHFR) gene. His older unaffected brother has a similar MTHFR genotype and high homocysteine. The whole exome sequencing revealed a likely pathogenic variant in the sodium voltage gated channel, alpha subunit 1(SCN1A) gene. CONCLUSION: CVST is a multifactorial disease. Prothrombotic conditions are the most common risk factors for CVST. High homocysteine due to the common MTHFR polymorphisms was previously attributed to various thrombotic conditions including CVST. Although high homocysteine due to MTHFR polymorphism may be a contributing factor, additional risk factors such as blood flow abnormalities during SCN1A related seizures may be needed for thrombosis.

Treatment outcomes in non-occlusive mesenteric ischemia and post-treatment return to social activities.

PURPOSE: To investigate the treatment outcomes of patients with non-occlusive mesenteric ischemia (NOMI) at our institution, we focused on their post-treatment return to social activities. METHODS: This study included patients with suspected NOMI who were referred to our department between 2011 and 2023. In-hospital mortality was also investigated as a prognostic factor. The Glasgow-Pittsburgh Outcome Categories (GPOC) score was used to evaluate the return to social activities. The relationship between in-hospital mortality and GPOC scores and patient background and treatment factors was examined. RESULTS: Eighty-two patients were included in the study. Among them, 54 (65.9%) died during hospitalization. Only 9 patients (11%) returned to their social activities. In the multivariate analysis, non-surgical management was found to be the only independent factor for in-hospital mortality. Positive portal venous gas on computed tomography, no open abdomen, no pre-onset catecholamine administration, platelet count < 100,000/µL, lactate level < 5 mmol/L, APTT < 46 s, and Sequential Organ Failure Assessment score < 11 were factors significantly associated with an increased likelihood of return to social activities. CONCLUSION: This is the first study to assess the post-treatment return to social activities among patients with NOMI. Our findings highlight the concerning reality that survivors may face prolonged dependence on medical care.

In-hospital mortality and associated factors among patients admitted with venous thromboembolism at selected public hospitals of Harar Town, Eastern Ethiopia.

Background: Venous thromboembolism is the third most common cause of cardiovascular death and is responsible for more than 3 million deaths annually worldwide. Despite high rates of morbidity and mortality associated with venous thromboembolism, limited studies have been conducted on in-hospital mortality and its associated factors in Ethiopia, particularly in study settings. Objective: To assess in-hospital mortality and associated factors among patients admitted with venous thromboembolism at selected public hospitals of Harar town, Eastern Ethiopia, from 10 March 2018 to 8 March 2022. Methods: A retrospective cohort study design was conducted among 502 patients admitted with venous thromboembolism at Hiwot Fana Comprehensive Specialized Hospital and Jugal General Hospital using a simple random sampling technique. Data extraction formats were used to collect data from patient medical record cards. Then data were coded and entered into EpiData version 3.1 computer programs and exported to SPSS version 26 for analysis. Bivariate and multivariate backward Cox regression analysis was used to verify the associated factors of in-hospital mortality among venous thromboembolism patients. A p-value of less than 0.05 at a 95% confidence interval was used to establish a statistically significant association. Results: A total of 502 patient medical record cards with outcome variables were included in the study. More than half of the patients 350 (69.7%) were females. Among the 502 patients who were admitted with venous thromboembolism, 8.2% (95% CI: 5.6-10.6) of patients had in-hospital mortality. DM (AHR = 4.28, 95% CI: 1.80-10.15, p = 0.001) and unfractionated heparin duration (AHR = 10.26, 95% CI: 2.45-43.01, p = 0.001) were statistically significant association with venous thromboembolism mortality. Conclusion: Approximately 8.2% of venous thromboembolism patients died in the hospital. Diabetes and heparin were independently associated with higher mortality. Therefore, it is better to give more attention to the patients co-morbid with diabetes mellitus and for unfractionated heparin treatment duration to reduce venous thromboembolism mortality.

Factor V Leiden Heterozygous: Complicated by Recurrent Venous Thromboembolism and Bilateral Pulmonary Embolism.

Factor V Leiden (FVL) is a hypercoagulable disorder that puts patients at increased risk of initial venous thromboembolism (VTE). However, those with heterozygote status are not usually susceptible to recurrent VTE. This is a case of a 35-year-old Caucasian male who presented to the emergency department with shortness of breath and chest pain. He had a past medical history of superficial thrombophlebitis and deep vein thrombosis (DVT) and was known to be FVL heterozygous. His home medications did not include anticoagulation medications at the time of presentation to the emergency department. The patient was diagnosed with bilateral pulmonary embolisms (PEs) secondary to a recurrent DVT. Initial treatment included a pulmonary thrombectomy and a lower extremity thrombectomy. Despite the patient being placed on heparin, there was a recurrence of the PE three days later, requiring a repeat pulmonary thrombectomy. This case of recurrent VTE in a heterozygous FVL patient is unusual and should lead to new considerations on the approach to lifelong anticoagulation in these patients.

Multi-Modal Venous ThromboembolicProphylaxis Aids in Risk Reduction Following Splenectomy in Female and Male Mice.

INTRODUCTION: Splenectomy (SPLN) is associated with elevated risk of venous thromboembolic (VTE) disease. Enoxaparin (ENX) is a low-molecular-weight heparin agent used in VTE chemoprophylaxis. Early aspirin administration ameliorates postSPLN platelet hyperaggregability in male mice. Previous literature has excluded female mice, citing potential effects of estrogen on platelet count and activation as a reason. We hypothesized that multimodal therapy using aspirin and ENX would mitigate postoperative platelet aggregability in mice across sexes. METHODS: Murine models of SPLN included both male and female mice. Treatment groups included placebo gavage, sham laparotomy, SPLN alone, SPLN and aspirin, SPLN and ENX, and SPLN with aspirin and ENX (n = 5 per group). Chemoprophylaxis dosing was initiated before SPLN. Mice were euthanized on post-operative day (POD) 1 or 3; platelet counts were obtained and blood samples were analyzed via electrical impedance aggregometry. RESULTS: Females on POD 3 following SPLN demonstrated increased platelet count compared to female mice with no treatment intervention. Male and female mice demonstrated increased adenosine diphosphate (ADP)-induced platelet aggregability on POD 3 following SPLN compared to the placebo group. Treatment with aspirin and ENX decreased this post-SPLN platelet hyperaggregability in both sexes. Females demonstrated significantly higher ADP-mediated platelet aggregability in placebo, SPLN, and SPLN with aspirin and ENX when compared to males of identical treatment groups on POD 3. CONCLUSIONS: Platelet hyperaggregability following SPLN is mediated primarily by ADP in both males and females, but higher relative aggregability is demonstrated in females. Early administration of dual-agent VTE chemoprophylaxis utilizing aspirin and ENX mitigates this hyperaggregability and may aid in VTE risk reduction across sexes.

Anticoagulant therapy in renal insufficiency theme: Anticoagulation in complex situations.

Many patients with impaired renal function have concurrent indications for anticoagulant therapy, including atrial fibrillation and venous thromboembolism. For mild chronic kidney disease, data from clinical trials and existing guidelines can be applied to clinical management. The benefits and harms of anticoagulation therapy in patients with more advanced renal impairment are nuanced, as both thrombotic and bleeding risk are increased. Until recently, data regarding anticoagulants in severe renal impairment were primarily observational, but emerging evidence includes a few small clinical trials and the emergence of novel agents hypothesized to have improved efficacy and safety in this population. In this review, we summarize existing data on anticoagulation in patients with chronic kidney disease. We suggest a framework for anticoagulation decision-making in the burgeoning worldwide population of patients with chronic kidney disease.

Treatment of tumor-induced cerebral venous sinus stenosis: Technical note and review of the literature.

INTRODUCTION: Tumors that invade or compress the venous sinuses have the potential to impair venous drainage. Rarely, this may be so severe as to induce intracranial hypertension. Other studies have previously described venous sinus stenting (VSS) for the treatment of these symptomatic lesions. In this report, we present our series of eight cases of VSS for symptomatic tumor-induced venous sinus stenosis and review the existing literature. CASES: Eight patients with mostly intracranial tumors were found to have symptomatic venous sinus stenosis with the most common presenting symptom being elevated intracranial pressure. Six of the eight (75%) patients presented with papilledema on neuro-ophthalmological exam. The most affected locations were the transverse and sigmoid sinuses in four patients, followed by the superior sagittal sinus in three patients. All eight patients underwent VSS with no adverse events. In total, 6 out of 8 (75%) of patients had complete resolution of their symptoms, while the remaining patients experienced at least partial improvement. CONCLUSION: Tumors that cause symptomatic venous sinus stenosis may be successfully managed with VSS to improve venous drainage. This may facilitate continued conservative management of meningiomas or allow for treatment with noninvasive means, such as stereotactic radiosurgery. Depending on the size of the target stenosis, balloon-mounted coronary stents may be a suitable option to treat these lesions.

Comparison of different venous access ways for right heart catheterization - a meta-analysis.

BACKGROUND: Right heart catheterization (RHC) is a common diagnostic tool and of special importance in the diagnosis of pulmonary hypertension (PH). Until today there are no clear instructions or guidelines on which venous access to prefer. OBJECTIVES: This meta-analysis assessed whether the choice of the venous access site for elective RHC has an impact on procedural or clinical outcomes. METHODS: A structured literature search was performed. Single-arm reports and controlled trials reporting event data were eligible. The primary endpoint was a composite of access-related and overall complications. RESULTS: Nineteen studies including 6,509 RHC procedures were eligible. The results were analyzed in two groups. The first group compared central venous access (CVA; n=2,072) with peripheral venous access (PVA; n=2,680) and included only multi-arm studies (n=12, C/P-comparison). In the second group all studies (n=19, threeway-comparison) were assessed to compare the three individual access ways. The overall complication rate was low at 1.0% (n=68). The primary endpoint in the C/P-comparison occurred significantly less for PVA than for CVA (0.1% vs. 1.2%; p=0.004). In the threeway-comparison PVA had a significantly lower complication rate than femoral access (0.3% vs. 1.1%; p=0.04). Jugular access had the numerically highest complication rate (2.0%), but the difference was not significant compared to peripheral (0.3%; p=0.29) or femoral access (1.1%; p=0.32). CONCLUSION: This meta-analysis showed that PVA for RHC has a significantly lower complication rate than CVA. There was a low level of certainty and high heterogeneity. This pooled data analysis indicated PVA as the primary venous access for RHC.

Numerical simulation and in vitro experimental study of the hemodynamic performance of vena cava filters with helical forms.

Inferior vena cava filter (IVCF) implantation is a common method of thrombus capture. By implanting a filter in the inferior vena cava (IVC), microemboli can be effectively blocked from entering the pulmonary circulation, thereby avoiding acute pulmonary embolism (PE). Inspired by the helical flow effect in the human arterial system, we propose a helical retrievable IVCF, which, due to the presence of a helical structure inducing a helical flow pattern of blood in the region near the IVCF, can effectively avoid the deposition of microemboli in the vicinity of the IVCF while promoting the cleavage of the captured thrombus clot. It also reduces the risk of IVCF dislodging and slipping in the vessel because its shape expands in the radial direction, allowing its distal end to fit closely to the IVC wall, and because its contact structure with the inner IVC wall is curved, increasing the contact area and reducing the risk of the vessel wall being punctured by the IVCF support structure. We used ANSYS 2023 software to conduct unidirectional fluid-structure coupling simulation of four different forms of IVCF, combined with microthrombus capture experiments in vitro, to explore the impact of these four forms of IVCF on blood flow patterns and to evaluate the risk of IVCF perforation and IVCF dislocation. It can be seen from the numerical simulation results that the helical structure does have the function of inducing blood flow to undergo helical flow dynamics, and the increase in wall shear stress (WSS) brought about by this function can improve the situation of thrombosis accumulation to a certain extent. Meanwhile, the placement of IVCF will change the flow state of blood flow and lead to the deformation of blood vessels. In in vitro experiments, we found that the density of the helical support rod is a key factor affecting the thrombus trapping efficiency, and in addition, the contact area between the IVCF and the vessel wall has a major influence on the risk of IVCF displacement.

Aetiology and management of persistent withdrawal occlusion in venous ports in oncology patients.

INTRODUCTION: Persistent withdrawal occlusion (PWO) is a specific catheter malfunction characterized by the inability to withdraw blood through the device. The most common cause of PWO in ports is the presence of a fibroblastic sleeve (FS). If malfunction occurs, medication can be applied incorrectly with the increased risk of complications. METHODS: One hundred seventy-seven cases of PWO in venous ports were managed. We focused on evaluating the cause of PWO, the frequency of occurrence of FS, and the options to address the malfunction. The patients underwent fluoroscopy with a contrast agent administration. Mechanical disruption (MD) with a syringe of saline using the flush method was used; in case of its failure, subsequent administration of a lock solution with taurolidine and urokinase, or low-dose thrombolysis with alteplase was indicated. Demographic data were compared with a control group. RESULTS: A significantly higher proportion of female patients was found in the cohort of patients with PWO (80.3% vs 66.3%, p = 0.004), dominantly patients with ovarian cancer (12.8% vs 4.8%, p = 0.022). No effect of the cannulated vein or the type of treatment on the incidence of PWO was demonstrated. The presence of FS was verified in 70% of cases. MD with a syringe was successful in 53.5% of cases. A significantly shorter time to referral (3 weeks) was demonstrated with successful management. The overall success rate of achieving desobliteration by MD alone or in combination with a thrombolytic (urokinase or alteplase) administration was 97.4%. CONCLUSION: We created a method for resolving PWO using MD +/- application of thrombolytics with 97.4% success rate. Current evidence showed that FS is not likely to be affected by thrombolytic drugs; however, we have ascertained an effect of these drugs, proposing a hypothesis of microthrombotic events at the tip of the catheter if fibroblastic sleeve is present.