Inferior Vena Cava Occlusion Research Articles

Collapse of inferior vena cava during complex filter retrieval with consequent intra-procedural systemic hypotension and bradycardia: a case report

BackgroundProlonged dwelling time of inferior vena cava (IVC) filters has been shown to increase the need for the use of complex IVC filter retrieval techniques. In this report, we describe a case of complex retrieval of an IVC filter with prolonged dwelling time, which was temporarily accompanied by severe bradycardia and hypotension.Case presentationFifty-nine-year-old male patient past medical history of morbid obesity, atrial fibrillation status post-ablation, obstructive sleep apnea, and end-stage renal disease presented for IVC filter retrieval 16 years after placement. When the IVC filter was covered by sheaths, and the IVC was temporarily collapsed and occluded, the patient developed severe bradycardia and hypotension without compensatory tachycardia. Contrast injection through the common femoral vein sheath showed complete occlusion of IVC while the IVC filter was covered by both sheaths, likely due to the embedment of the IVC filter in the wall by extensive fibrinous tissues. IVC filter was successfully retrieved, and the blood pressure and heart rate were improved immediately afterward. A large non-occlusive IVC thrombus was identified on the final venogram, which was aspirated using a mechanical thrombectomy device.ConclusionComplex retrieval of IVC filters with prolonged dwelled time can result in acute severe bradycardia and hypotension due to vasovagal reaction, acute collapse, and occlusion of IVC in the setting of IVC filter embedment in the wall by extensive fibrinous tissues.

Patency outcomes of primary inferior vena cava repair in radical nephrectomy and tumor thrombectomy

ObjectiveThe reconstruction of inferior vena cava (IVC) during radical nephrectomy and venous tumor thrombectomy (RN-VTT) is mostly performed with primary repair or with a patch/graft. We sought to systematically evaluate the outcomes of IVC patency over short- to intermediate-term follow-up for patients undergoing primary repair of IVC and to assess the association with survival. MethodsA retrospective review of patients undergoing RN-VTT between January 2013 and August 2018 was conducted. Patients were followed until death, last available follow-up, or March 2022. The patency outcomes and IVC diameters were studied using follow-up cross-sectional imaging. The χ2 test, Student t test, and Kaplan-Meier survival analysis were used. ResultsSeventy-seven patients were included. The mean age was 59.2 ± 12.2 years and 45.4% had Mayo classification level III thrombus or higher. At a median follow-up of 36.5 months (13.3-60.7 months), the 3-year overall survival (OS) was 64%. Sixty patients underwent primary repair of the IVC and 48 of these patients were assessed for IVC patency. Ten patients (20.8%) developed caval occlusion, either from recurrent tumor (8.3%), new-onset bland thrombus (8.3%), or stenosis (4.2). The IVC patency seemed to be a significant predictor of OS (hazard ratio, 2.85; P = .021). Although the IVC diameters decreased significantly at the 3-month postoperative scan at the infrarenal (P = .019), renal (P < .001), and suprarenal (P < .001) levels, they did not decrease further on long-term follow-up imaging. ConclusionsIVC reconstruction with primary repair results in an overall patency rate of 80.2% with only a 4.0% rate of stenosis. Recurrence of tumor thrombus (8.3%) or bland thrombus (8.3%) are the predominant reasons for IVC occlusion after RN-VTT, and this outcome is associated with poor OS.

Role of Inferior Vena Cava (IVC) Recanalization in Patients with Back Pain, Secondary to IVC Obstruction in Budd-Chiari Syndrome.

To study the prevalence of back pain in patients of Budd-Chiari syndrome (BCS) with inferior vena cava (IVC) obstruction, and to evaluate the role of IVC recanalization in resolution of back pain. All patients with BCS and IVC obstruction who underwent IVC recanalization between January 2018 and October 2022 were included. Patients with degenerative spine disease or other identifiable causes for back pain were excluded; remaining patients were assessed for the presence of back pain. In patients with back pain, pain relief was assessed at 24 h following IVC recanalization. Fifty-eight patients with BCS and IVC occlusion were identified, of which six with degenerative spine diseases were excluded. Of the remaining 52 patients, 34 (65.4%) had back pain, with pain score between 3 and 9. Engorged epidural venous plexus on preprocedural imaging (p = 0.002), and degree of luminal narrowing (p = 0.021) had a significant association with back pain. Twenty-nine of thirty-four patients (85.3%) with back pain had pain relief immediately following IVC recanalization, more so in patients with engorged epidural venous plexus on preprocedural imaging (p < 0.001). Back pain is one of the under-reported symptoms of IVC obstruction in BCS. IVC recanalization by IVC angioplasty with or without stenting relieves back pain due to the decompression of engorged epidural veins.

Longitudinal Validation of Right Ventricular Pressure Monitoring for the Assessment of Right Ventricular Systolic Dysfunction in a Large Animal Ischemic Model.

RV pressure monitoring can detect changes in RV systolic performance assess by RV Ees following the development of an acute RV ischemic model. Acute ischemic RV dysfunction was induced by progressive embolization of microsphere in the right coronary artery to mimic RV dysfunction clinically experienced during cardiopulmonary bypass separation caused by air microemboli. RV hemodynamic performance was assessed using RV pressure waveform-derived parameters and RV Ees obtained using a conductance catheter during inferior vena cava occlusions. Acute ischemia resulted in a significant reduction in RV Ees from 0.26 mm Hg/mL (interquartile range, 0.16-0.32 mm Hg/mL) to 0.14 mm Hg/mL (0.11-0.19 mm Hg/mL; p < 0.010), cardiac output from 6.3 L/min (5.7-7 L/min) to 4.5 (3.9-5.2 L/min; p = 0.007), mean systemic arterial pressure from 72 mm Hg (66-74 mm Hg) to 51 mm Hg (46-56 mm Hg; p < 0.001), and mixed venous oxygen saturation from 65% (57-72%) to 41% (35-45%; p < 0.001). Linear mixed-effect model analysis was used to assess the relationship between Ees and RV pressure-derived parameters. The reduction in RV Ees best correlated with a reduction in RV maximum first derivative of pressure during isovolumetric contraction (dP/dtmax) and single-beat RV Ees. Adjusting RV dP/dtmax for heart rate resulted in an improved surrogate of RV Ees. Stepwise decreases in RV Ees during acute ischemic RV dysfunction were accurately tracked by RV dP/dtmax derived from the RV pressure waveform.

A novel strategy to reduce the recirculation of venovenous extracorporeal membrane oxygenation: Inferior vena cava closure technology.

The recirculation of venovenous extracorporeal membrane oxygenation (VV-ECMO) will decrease the efficiency of respiratory support. We report a patient with refractory severe acute respiratory distress syndrome (ARDS). Even with the support of ECMO and mechanical ventilation (MV), it is still difficult to correct hypoxemia. In this case, we placed a balloon catheter above the ECMO drainage cannula in inferior vena cava (IVC), and then occlusion the IVC with the water-filled balloon. After the occlusion, the patient's hypoxemia was quickly improved, and angiography proved that the recirculation has been significantly reduced. In this case, IVC occlusion technology greatly reduces recirculation. Its advantages lie in simple operation, low cost, short term safety, which probably act as an innovative method to reduce recirculation.

Immune Checkpoint Inhibitors (ICI) Promote Neutrophil-Platelet Aggregate and NET Formation in Tumor-Bearing Mice

Introduction: Immune checkpoint inhibitor (ICI) therapy has revolutionized cancer treatment. Despite remarkable clinical benefit, there are numerous immune-related adverse events (irAEs) associated with ICI therapy. Cancer-associated thrombosis (CAT) is a common complication of cancer, and ICI-associated thrombosis (ICI-CAT) is an underappreciated irAE. There is no data available concerning the mechanisms underlying ICI-CAT. To address this issue, we have established a murine model of ICI-CAT in which tumor-bearing mice treated with ICI develop larger thrombi than those treated with control IgG. We have observed that these ICI-treated mice display greater numbers of neutrophils in thrombi, and increased levels of circulating neutrophil extracellular traps (NETs). Methods: ICI (anti-PD-1 and anti-CTLA-4) was infused into Balb/c mice bearing subcutaneous CT26 colorectal tumors. Neutrophils (CD11b+ Ly6G+) as a percentage of total WBC was assessed using an automated hematology analyzer. Neutrophil-platelet doublets and aggregates were determined by flow cytometry analysis in using antibodies for CD41 (GPIIb) and CD62P (P-selectin). Circulating neutrophils were isolated from tumor-bearing mice treated with IgG and ICI 48h after IVC occlusion using an EasySep mouse neutrophil enrichment kit (STEMCELL technologies). For NET staining, isolated neutrophils (5x105 cells/well) were seeded on poly-L lysine coated coverslips, and treated with or without phorbol myristate acetate (PMA, 100 nM) for 4 h in 37°C. Neutrophils were then blocked using 5% FBS and stained, without permeabilization, using rabbit monoclonal anti-histone H3 (citrulline R2+R8+R17) antibody (ab5103, Abcam). Extracellular CitH3 was detected using anti-rabbit Alexa Fluor 488 secondary antibody. Results: Thrombi in ICI-treated mice were larger and contained greater numbers of neutrophils than thrombi from IgG-treated mice. Complete blood counts demonstrated that neutrophil numbers increased 3-fold in tumor bearing (38.2%) vs non-tumor bearing mice (12.8%) (Data not shown). However, neutrophils from ICI-treated tumor-bearing mice demonstrated significantly more spontaneous NET formation than those isolated from mice treated with control IgG (66.7% vs 18.2%). Smaller differences were also noted in response to PMA (Fig. A). Since binding of platelets to neutrophils is one cause of NET release, we also determined the frequency of neutrophil-platelet aggregates circulating in tumor-bearing mice treated with ICI or control IgG. Increased levels of circulating neutrophil-platelet aggregate in ICI-treated mice were present in a doublet CD41+Ly6G+ population (44.8% vs 22.3%); similar results were noted when platelets were stained with the activation marker CD62 (P-selectin) (8.5% vs 1%) (Fig. B, Left). The frequency of larger neutrophil-platelet aggregates followed a similar trend (ICI vs IgG; 75.8% vs 30% for CD41; 48.1% vs 7.7% for CD62P) (Fig. B, Right). Conclusions: Circulating neutrophils from ICI-treated, tumor bearing mice demonstrate increased spontaneous NET release. Moreover, elevated levels of circulating platelet-neutrophil doublets and aggregates are present in ICI-treated mice compared to those treated with control IgG. These results suggest a potential mechanism of ICI-induced thrombosis, and that platelet-neutrophil interactions may stimulate NET release in ICI-treated mice. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Tissue Factor (TF) Is Upregulated in Tumor-Bearing Mice Treated with Immune Checkpoint Inhibitor (ICI)

Introduction: Venous thromboembolism (VTE) is an important adverse event associated with immune checkpoint inhibitors (ICI) in cancer patients (12-15% annual rate). We have developed a murine model of venous thrombosis associated with ICI therapy (referred to as ICI-CAT). We found that mice bearing CT26 colon carcinoma treated with ICI developed larger thrombi following IVC occlusion compared with mice treated with IgG. ICI did not increase thrombus weight in mice without tumors. Tissue factor (TF) plays an important role in cancer-associated thrombosis (CAT) in patients treated with conventional therapies, and TF+ extracellular vesicles (EV) were associated with the development of VTE in pancreatic cancer. However, little is known about the impact of ICI on TF expression in patients treated with ICI. To address the underlying mechanism of ICI-associated thrombosis (IAT), we have examined the expression of TF in tumor and immune cells, as well as circulating EV, in our murine CT26 model. Methods: A syngeneic colon carcinoma model (CT26) in BALB/c mice was utilized to evaluate ICI-CAT following inferior vena cava ligation (stasis). Tumor tissue was analyzed for TF expression by immunoblotting using an anti-TF antibody (ab189483, Abcam). Tumor tissue was also dissociated, and TF-positive cells were assessed by flow cytometry analysis with CD45+ and CD45- gating using antibodies for CD11b, Ly6C, Ly6G (BioLegend), and TF (R&D). EV were isolated from platelet poor plasma from ICI or control IgG-treated mice by centrifugation (20,000 x g). Procoagulant activity of EV TF was measured using a chromogenic substrate to detect FXa generation following incubation of EV with FVIIa in the presence or absence of an anti-TF antibody. Results: Treatment of tumor-bearing mice with ICI markedly induced TF expression in tumors (Fig. A, Leftupper). Furthermore, levels of EV TF antigen (Fig. A, Left bottom) and EV TF activity (Fig. A, Right) were increased in mice treated with ICI. To explore the cellular origin of TF, we performed flow cytometry with dissociated tumor cells. A greater percentage of TF-positive cells in both the CD45+ (37.8%) and CD45- (74.6%) populations were detected in tumors from ICI treated mice compared to those treated with control IgG (27.9% and 49.8%, respectively), suggesting both tumor and tumor-infiltrating immune cells contribute to the larger thrombi observed in ICI-treated mice (Fig. B). Further analysis of CD45+ TF+ cells by CD11b gating (data not shown) revealed that a TF expression in a monocyte population (CD11b+ Ly6C+) was increased 3-fold by ICI (46.6%) compared to control IgG (14.2%) (Fig. C). We also found that TF expression was increased in cultured CT26 cells in response to interferon-g, but not in response to anti-PD-1 and anti-CTLA-4 antibodies, suggesting that ICIs do not directly upregulate TF and that more complex cellular interactions and inflammatory changes may be involved. Conclusions: ICI treatment of tumor-bearing mice results in increased tumor TF expression and EV TF expression. TF was also upregulated in immune cells in the tumor microenvironment after ICI treatment, including both tumor/stromal cells (CD45-), and tumor-associated monocytes and neutrophils (CD45+). These results suggest that multiple underlying mechanisms and diverse cellular expression underlie TF expression in this model, and that these processes many contribute to the larger thrombi observed in ICI-treated mice. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

P02] Inferior Vena Cava Reconstruction: A Single Centre Experience

<h3>Objective</h3> Inferior vena cava (IVC) stenting is carried out for symptomatic chronic IVC stenosis or occlusion, and for the treatment of malignant IVC obstruction. The patency of IVC stents placed for both acute on chronic and chronic venous occlusion was determined. <h3>Methods</h3> Retrospective analysis of prospectively collected data was completed on all patients who underwent technically successful IVC stenting for treatment of symptomatic venous outflow obstruction or stenosis between February 2015 and November 2021. All patients had standard pre-operative work up, including venography ± intravascular ultrasound for chronic cases, and followed standard anticoagulation and surveillance programmes post-procedure, unless there was malignant disease. <h3>Results</h3> Sixteen patients underwent IVC stenting. Seven cases (43%) presented acutely with deep vein thrombosis and chronic underlying IVC stenosis or occlusion. Five cases (31%) were for symptomatic malignant external IVC compression. In four cases (25%), kissing iliac stents were placed into the IVC to treat infrarenal IVC disease. The remainder required single stents in the IVC, or were combined with double barrelled iliac stents. Re-intervention occurred in four cases (25%) for in stent thrombosis. Primary patency was 75%, and primary assisted patency was 88%. Stenting the IVC in all cases for malignant obstruction gave symptomatic relief. <h3>Conclusion</h3> Stenting of the occluded/atretic IVC may require additional access from the right internal jugular vein. Stenting above and across the renal veins did not cause any additional complications in this series. Stenting of the IVC is safe, and can give significant improvement in symptoms in patients with limited alternative options for treatment.

Primary Inferior Vena Cava Leiomyosarcoma Presenting with Proximal Occlusion with Deep Venous Thrombosis and Lower Extremity Edema: Reconstruct vs Ligate Post Resection? A Single Retrospective Case Report

Introduction: Primary leiomyosarcomas of the inferior vena cava (IVC) are rare tumors with a poor prognosis. Curative treatment remains surgical resection with clear margins. Reconstruction vs ligation of the IVC is debatable, especially if the proximal IVC is occluded. This report presents the surgical management of a patient presenting with acutely worsening lower extremity edema and biopsy proven IVC leiomyosarcoma. Methods: This is a retrospective chart review, and the patient was followed up at 2 weeks and at 3 months. Patient provided consent for creation of this case report. Results: The patient’s age at presentation was 67 years and she was of female gender. The IVC leiomyosarcoma had a maximum diameter of 4.8cm, involved the infrarenal IVC only, and the proximal segment was occluded due to bilateral iliofemoral deep venous thrombosis (DVT). She underwent an R0 resection, with immediate reconstruction using 14mm ringed PTFE. Postoperatively, she was noted to have worsening lower extremity edema. The plan was to recanalize her DVTs via endovascular thrombectomy and stenting, however the patient’s edema improved with compression alone. At 2 weeks follow up, her edema had completely resolved. At 3 months follow up, postoperative CT scan showed expected occluded infrarenal IVC graft, and no evidence of recurrent disease. Conclusion: Reconstructing the occluded IVC after resection of the primary IVC leiomyosarcoma gives the patient the option for future endovascular recanalization if there is ongoing lower extremity edema. Further follow up and research is warranted to determine if this provides a feasible long-term solution.

A cross-species validation of single-beat metrics of cardiac contractility.

The assessment of left ventricular (LV) contractility in animal models is useful in various experimental paradigms, yet obtaining such measures is inherently challenging and surgically invasive. In a cross-species study using small and large animals, we comprehensively tested the agreement and validity of multiple single-beat surrogate metrics of LV contractility against the field-standard metrics derived from inferior vena cava occlusion (IVCO). Fifty-six rats, 27 minipigs and 11 conscious dogs underwent LV and arterial catheterization and were assessed for a range of single-beat metrics of LV contractility. All single-beat metrics were tested for the various underlying assumptions required to be considered a valid metric of cardiac contractility, including load-independency, sensitivity to inotropic stimulation, and ability to diagnose contractile dysfunction in cardiac disease. Of all examined single-beat metrics, only LV maximal pressure normalized to end-diastolic volume (EDV), end-systolic pressure normalized to EDV, and the maximal rate of rise of the LV pressure normalized to EDV showed a moderate-to-excellent agreement with their IVCO-derived reference measure and met all the underlying assumptions required to be considered as a valid cardiac contractile metric in both rodents and large-animal models. Our findings demonstrate that single-beat metrics can be used as a valid, reliable method to quantify cardiac contractile function in basic/preclinical experiments utilizing small- and large-animal models KEY POINTS: Validating and comparing indices of cardiac contractility that avoid caval occlusion would offer considerable advantages for the field of cardiovascular physiology. We comprehensively test the underlying assumptions of multiple single-beat indices of cardiac contractility in rodents and translate these findings to pigs and conscious dogs. We show that when performing caval occlusion is unfeasible, single-beat metrics can be utilized to accurately quantify cardiac inotropic function in basic and preclinical research employing various small and large animal species. We report that maximal left-ventricular(LV)-pressure normalized to end-diastolic volume (EDV), LV end-systolic pressure normalized to EDV and the maximal rate of rise of the LV pressure waveform normalized to EDV are the best three single-beat metrics to measure cardiac inotropic function in both small- and large-animal models.

Lower Limb Weakness due to Spinal Venous Congestion in Chronic Inferior Vena Cava Occlusion: A Case Report.

A 31 year-old male presented with a long history of reduced sensation and motor function in his lower limbs upon waking every morning, lasting 30-50 minutes during which he was unable to ambulate. He was involved in a severe road traffic accident as a child, and was born prematurely requiring prolonged neonatal hospitalisation. Both duplex ultrasonography and magnetic resonance venography identified an occlusion of the IVC, with patent common femoral and iliac veins draining into large spinal collaterals. No other cause was identified for his symptoms. After appropriate multidisciplinary team discussion and patient counselling, the patient proceeded to have endovenous recanalization of his IVC and common iliac veins with dedicated venous stents. Post-operatively, the patient reported an immediate resolution of neurological symptoms, with an improvement in quality of life questionnaire scores and with stent patency at 9-month follow up. IVC occlusion with symptomatic spinal venous congestion is a rare condition which may be successfully treated with endovascular iliocaval recanalization, although long-term outcomes of this treatment are still unknown.

Preclinical evaluation of a veno-venous bypass device for liver transplantation based on the principle of magnetic levitation drive

Objective: To explore the performance of a self-made venous-venous bypass (VVB) device for liver transplantation based on the principle of magnetic levitation drive. Methods: Experimental study was conducted from August 2020 to January 2022. Eight Bama minipigs underwent VVB of hepatic portal vein-femoral vein-internal jugular vein after occlusion of hepatic portal vein and inferior vena cava. The animals were divided into two groups according to the VVB devices used during VVB. A self-made VVB device was used in group A(n=5),and an imported VVB device was used in group B(n=3). The hemodynamic changes of the two groups of animals were compared at 6 time points including before vascular occlusion, during vascular occlusion, 30 minutes, 60 minutes, 90 minutes after the start of VVB, and 30 minutes after vascular opening. In addition,the changes of blood compatibility indexes,intestinal injury indexes,kidney injury indexes and internal environment indexes of the two groups of animals at each time point were compared. The independent samples t test was used for the quantitative data between the two groups with non-repeated measures,and the repeated measures analysis of variance was used for the quantitative data between the two groups with repeated measures. Results: During the VVB of the two devices,the venous drainage was sufficient,and the main manifestations were that the color of the intestine of the Bama miniature pig was ruddy, the peristalsis was normal, and the urine output was normal. There were no significant differences in hemodynamics,blood injure indexes,intestinal injury indexes,kidney injury indexes,neutropil gelatinase-associated lipocalin,and internal environment indexes(all P>0.05).The indexes at 30 minutes after vascular opening in the group A and the group B were as follows:mean arterial pressure were (71.0±7.7)mmHg(1 mmHg=0.133 kPa) and (74.0±8.7)mmHg,central venous pressure were (7.0±1.4)cmH2O(1 cmH2O=0.098 kPa) and (7.7±0.6)cmH2O,heart rate were (131±10) beats/minutes and (132±8)beats/minutes; red blood cell count were (6.43±0.89)×1012/L and (6.32±0.58)×1012/L,hemoglobin were (108.4±5.9)g/L and (110.0±3.5)g/L,free hemoglobin were (78.28±3.96)mg/L and (78.08±4.54)mg/L; intestinal fatty acid binding protein were (2.27±0.49)μg/L and (2.40±0.78)μg/L;creatinine were (68.30±9.77)μmol/L and (79.90±26.91)μmol/L,blood urea nitrogen were (3.94±1.39)mmol/L and (3.45±0.65)mmol/L;neutropil gelatinase-associated lipocalin were (4.02±0.53) μg/L and (3.86±0.23)μg/L;pH value were 7.27±0.04 and 7.23±0.03,lactic acid were (6.18±2.62)mmol/L and (4.30±0.50)mmol/L,concentrations of Na+ were (136.3±3.0)mmol/L and (137.6±1.6) mmol/L,concentrations of K+ were (3.89±0.42) mmol/L and (3.98±0.17)mmol/L,concentrations of Ca2+ were (1.40±0.03)mmol/L and(1.40±0.04)mmol/L;all indexes in the two group had no differences(all P>0.05). Conclusion: The self-made venous bypass device can be safely and effectively applied to VVB of Bama minipigs,and achieves the same performance as the imported venous bypass device.

Clinical and imaging outcomes of OptionELITE vena cava filter placement procedures

ObjectiveWe sought to determine the clinical and imaging outcomes after placement of the OptionELITE inferior vena cava (IVC) filter (Argon Medical Devices, Plano, TX). MethodsThe clinical characteristics and imaging findings of patients who had undergone OptionELITE filter placement at six affiliated hospitals between January 1, 2013 and April 19, 2019, were analyzed. Data were obtained from the Radiology Information System, imaging database, and electronic medical records. The patients were followed up until 1 month after filter removal, death, or the first clinic visit and imaging study after June 1, 2019. ResultsA total of 603 filter placement procedures in 594 patients were evaluated. Of the 603 procedures, 602 were technically successful (99.8%). Of the 594 patients, 356 had presented with acute pulmonary embolism and/or deep vein thrombosis. A total of 189 filters were retrieved from the 191 patients for whom retrieval had been attempted at 4.3 ± 6.3 months (median, 2.5 months) after placement. The 414 filters without removal procedures had been followed up for 14.8 ± 17.7 months (median, 6.9 months). During the follow-up period, 57 patients (9.5%) had developed new or worsening deep vein thrombosis caudal to the filter and 19 (3.2%) had experienced new symptomatic nonfatal pulmonary embolism after filter placement. One filter had migrated and fractured, and another filter had fractured and a strut was lost. Perforation was demonstrated equivocally in 12 (3%) and definitely in 17 (4.3%) of 399 patients with adequate imaging studies available, with penetration into surrounding structures in 13 patients (3.3%). Of 332 patients with adequate imaging studies, 12 (3.6%) had developed substantial IVC thrombosis and 4 (1.2%) had developed IVC occlusion. ConclusionsThe rates of symptomatic pulmonary embolism and filter-related complications were low after OptionELITE IVC filter placement, and filter retrieval, when attempted, was 99% successful.

Influence of Exercise on Inferior Vena Cava Wall Interaction with Inferior Vena Cava Filters: Results of a Pilot In Vivo Porcine Study

Abstract Objectives The aim of this study was to assess the effect of mild exercise on inferior vena cava (IVC) filter interaction with imaging and pathological features with the neighboring vessel wall utilizing a porcine model. Materials and Methods After Institutional Animal Care and Use Committee (IACUC) approval, retrievable Option Elite IVC filters were implanted in six Yorkshire pigs utilizing the right common femoral vein approach under general anesthesia. Group A (n = 4) pigs remained sedentary for 4 weeks. Group B (n = 2) pigs were exercised using a harness and treadmill for 10 minutes/day for 4 days/week. At approximately 4 weeks, IVC venograms were performed and the pigs were sacrificed. After laparotomy, the IVC was ligated above and below the filter, excised and fixed in formalin. Gross and histological examination of the IVC was performed. Gross images of each sample were captured before removal of the filters. One longitudinal, one tangential, and five transverse representative sections were processed for paraffin sectioning and hematoxylin and eosin slides were prepared. A pathologist examined all tissues to assess differences between normal vein, group A and group B pigs. The pathologist provided an overall assessment and representative images. Results All IVC filter implantations were technically successful without adverse effects. There was no incidence of caval thrombosis, filter strut fracture, or filter migration in either group. On gross pathological examination, IVC of the pigs in group B demonstrated more perivascular and mural fibrosis than those pigs in group A. Histopathological findings correlated with gross findings. Conclusions In this pilot study, there were no incidence of IVC filter strut fracture, penetration or IVC occlusion in sedentary or exercised pigs. However, there tended to be more perivascular and mural fibrosis on pathological examination of inferior vena cavas from exercised pigs. Further larger scale studies may employ the porcine model to further understand the role exercise may play on IVC filter and caval wall interaction.

A retrospective cohort study assessing the incidence of inferior vena cava (IVC) occlusion following prophylactic IVC filter insertion: Is anticoagulation necessary during filter dwell?

BackgroundInferior vena cava (IVC) filters play a role in preventing venous thromboembolism after major trauma where deep venous thrombosis (DVT) risk is up to 80%. It has been suggested that IVC filters are thrombogenic and many patients are therefore placed on therapeutic anticoagulation during IVC filter dwell citing concern of in situ IVC thrombosis, even in the absence of existing DVT. MethodsBetween 1 June 2018 and 31 December 2021, this retrospective study assessed the incidence of IVC thrombosis following prophylactic IVC filter insertion. Groups were defined according to the presence or absence of therapeutic anticoagulation during filter dwell. The primary outcome was the presence or absence of IVC thrombus at retrieval. ResultsA total of 124 patients were included. Anticoagulation was prescribed in 29 and anticoagulation was not prescribed in 63. A further 32 patients developed a new thrombosis episode after the prophylactic IVC filter was placed, and 29 were prescribed anticoagulation part-way during filter dwell as a result of this diagnosis. No cases of IVC occlusion were observed in any patient group. ConclusionsCaval thrombosis was not observed after prophylactic filter placement, with or without the prescription of anticoagulation. While prospective trials are needed to increase the level of evidence, based on these results the use of therapeutic anticoagulation during IVC filter dwell should not be dictated by the presence of an IVC filter alone but rather by the presence of a related thrombosis event.

Study of Morphological Changes in Rat Liver Caused by Occlusion of Inferior Vena Cava

Up to date, there are no reports on animal survival rate and morphological changes in the liver caused by the impairment of blood outflow from the liver and its time dependence. Moreover, the impact of duration and degree of occlusion of inferior vena cava on pathological changes was not investigated yet. This study aimed at the assessment of the survival rate and morphological changes in the liver with varying degrees of occlusion of inferior vena cava. The exact timing of the reversibility of pathological processes was determined. Rats (n= 160) were randomly divided into five groups: I - control group (CG) (n= 20); II - sham group (SG) (n=20); III - intervention group (IG-1) (narrowing of the lumen of the inferior vena cava by 25%) (n=40); IV intervention group (IG-2) (narrowing by 50%) (n= 40); and intervention group V (IG-3) (narrowing by 75%) (n= 40). The level of postoperative pain, the body and liver weight of the animals, histological examination, morphometry, and macroscopic evaluation of abdominal organs were carried out on the 1, 3, 7, 14, and 30 days following the surgical intervention. The survival rate of animals was assessed using the Kaplan-Meier method. On the 30th day, the rat grimace scale indices in the IG-1 (P≤0.05), IG-2, and IG-3 (P ≤ 0.001) groups were higher. By body weight, this indicator on the 30th day was lower in the IG-1 (P≤0.05), IG-2, and IG-3 (P ≤ 0.001) groups compared to the CG and SG groups. In the IG1 and IG2 groups, the survival rates were 72.5% and 65.0%, respectively. The lowest survival rate was observed in the IG3 group (22.5%). Compression of the inferior vena cava by 75% led to an increase in animal mortality and the development of persistent morphological changes in the liver. At the same time, the survival rate of animals and the extent of changes in the liver with narrowing of the inferior vena cava by 25% and 50% had similar results. The results acquired possess scientific and practical importance.

Preservation of Right Ventricular Contractility After Transient Phenylephrine‐Induced Pressure Overload in Swine

ObjectiveWe have previously demonstrated that a transient phenylephrine (PE)‐induced rise in systemic arterial blood pressure leads to reversible left ventricular (LV) systolic dysfunction in the absence of ischemia (i.e., “stretch‐induced stunning”). However, the extent to which this phenomenon occurs in the right ventricle (RV) is unclear. Accordingly, the present study was designed to assess changes in pulmonary artery (PA) pressure and RV function during and after systemic administration of PE in swine.MethodsClosed‐chest propofol‐anesthetized swine (n=5) were instrumented with a Swan‐Ganz catheter and an admittance catheter for continuous measurement of PA pressure, RV pressure, and RV volume (ADV500; Transonic SciSense, Inc.). Ventricular end‐diastolic and end‐systolic volumes were assessed by multi‐detector computed tomography with iodinated contrast (1 mL/kg at 4 mL/s) before, during, and 30‐minutes after transient pressure overload elicited by a 1‐hour intravenous infusion of PE (18 mg/hour). Load‐independent RV systolic function was derived from RV pressure‐volume loops collected during inferior vena cava occlusion at baseline and 30 min after PE.ResultsPE elicited a significant rise in PA pressure (27±1/14±1 to 43±1/23±31mmHg; p&lt;0.05) and RV pressure (25±2/3±1 to 44±2/8±2 mmHg; p&lt;0.05) that normalized 30‐minutes after the end of the infusion period (PA: 28±1/11±1 mmHg; RV: 29±5/4±2 mmHg). This was accompanied by a significant increase in RV end‐diastolic and end‐systolic volumes and decrease in RV ejection fraction that tended to persist 30‐minutes after cessation of PE (Table; top panel). However, load‐dependent (dP/dtmax) and load‐independent (ESPVR and PRSW) parameters of RV systolic function were preserved after PE‐induced TPO (Table; bottom panel).ConclusionsDespite causing a significant rise in RV preload volume and pressure, transient PE‐induced pressure overload is not associated with RV contractile dysfunction during the post‐infusion period. The absence of stretch‐induced stunning in the RV may be linked to inherent differences in compliance relative to the LV as well as a diminished pressor response to PE in the pulmonary vs. systemic circulation.

Spectrum of Interventional Procedures During Hybrid Central Line Placement in Pediatric Intestinal Rehabilitation Patients With End-Stage Vascular Access.

BackgroundLoss of available central vein access sites for parenteral nutrition delivery represents one of the main indications for intestinal transplantation in children with intestinal failure. Placement of central venous catheters can be challenging in advanced loss of patent venous pathways. We recently described the hybrid technique (interventional plus surgical approach) of central line placement in children. The aim of this study was to describe and analyze the interventions used during the hybrid procedures regarding feasibility, safety and outcome.MethodsWe retrospectively analyzed the course of all children in our intestinal rehabilitation program undergoing hybrid central line placement. We evaluated patients' conditions, interventional techniques and surgical peculiarities as well as outcome.Results203 children were treated in our intestinal rehabilitation program between 2010 and 2021. Due to loss of venous access, hybrid technique was performed in 53 children during 76 interventions. In 40 cases the same vessel was reused via Seldinger technique. Among the 30 ultrasound-guided new vessel punctures, 12 were performed by puncture of collateral vessels. Extended interventions due to thoracic central venous obstruction and/or thrombosis requiring additional access via a femoral vein for rehabilitation of the vascular system was performed during 29 procedures including catheter extraction (1), angioplasties (18), stent placement (1), revascularization (5) and thrombectomy (4). Placement of a central line was not possible in 6 children which eventually underwent extended thoracic/vascular surgery: in three children the previously placed catheter could not be removed, in one child, placement of a thrombectomy-catheter was not possible because of inferior vena cava occlusion, and in two children, revascularization failed. Intestinal transplantation was considered in one patient because of impending loss of vascular access. Two self-limiting minor extravasations and one intervention-associated pericardial effusion occurred.ConclusionsHybrid interventions for central venous catheter placement and vascular rehabilitation enable a high success rate in children with intestinal failure and end-stage vascular access, circumventing the need for intestinal transplantation or advanced surgery. The relevant procedures are complex and require a foresighted and individualized approach with a wide range of interventional techniques. If performed with expertise, this combined interventional/surgical approach is feasible and safe.

Establishing a jugular-femoral venous route for recanalization of complicated inferior vena cava in Budd\u2013Chiari Syndrome after transfemoral access failure

Recanalization of inferior vena cava (IVC) with complete obstruction, old thrombosis or long segmental stenosis/obstruction (complicated IVC) via transfemoral access may fail in patients with Budd-Chiari syndrome (BCS). In this study, 34 consecutive patients with BCS underwent recanalization of complicated IVC occlusion via jugular-femoral venous (JFV) route establishment. BCS with complicated IVC was detected by reviewing preoperative color Doppler ultrasonography or computed tomography (CT) venography, and confirmed by intraoperative venography. Clinical data on technical success, complications, and follow-up outcomes were analyzed. Except for one patient received surgical repair of rupture IVC after recanalization, technical success of IVC recanalization was achieved in remaining 33 (97.1%) patients. No perioperative deaths was found. Three complications were observed during recanalization, for a complication rate of 8.8%. Bleeding of the femoral vein was observed in one patient, and two patients showed bleeding of IVC. The IVC lesion diameter and blood flow of the distal IVC increased significantly after the procedure. Twenty-four patients (77.4%) were clinically cured, and four patients (12.9%) showed clinical improvement. The 1-year, 3-year, 5-year primary patency rates were 85.9%, 76.4% and 70.0%, respectively. The 5-year secondary patency rate was 96.8%. There were three deaths during follow up, and the 5-year survival rate was 90.0%. In conclusion, JFV route establishment and angioplasty for complicated IVC is safe and effective for patients with BCS after transfemoral access failure.

The Left Ventricular End-Systolic Pressure Correlation with Aortic Valve Timing; a Novel Inotropic Index Description Using a Dual Pressure Catheter

Myocardial contraction is generated by ventricular pressure in early systole by the isometric force against closed valves, as ventricle is contracting without changing volume. This initial contractile phase of cardiac cycle (early systole) is followed by rapid shortening, isotonic contraction, allowing ejection of the blood against changing LV afterload. LV is coupled to the systemic arterial pressure; hence LV ejection is closely linked to the properties of the aortic valve, aorta, and its distributing arteries. Isometric relationship in the LV was characterized using the load-dependent example (naïve vs. post-dobutamine), observed mostly in case of rate of rise of LVP, LV ESP and decrease of pulse wave velocity, characteristics of LV baroinometry. Furthermore, by performing load-independent maneuver, afterload (LV ESP) was adjusting at every cardiac cycle, while an assessment of LV ESP and aortic valve timing was able to be established. By plotting decaying LV ESP against aortic valve timing, highly linear correlation of load-independent isotonic, but also an isometric contractility was captured. Steeper linear slope and time-axis intercept (IC) were identified in case of post-inotropic challenge, recapitulating changes otherwise measured during pressure-volume exam. This relationship, measured by dual-pressure catheter, could serve as novel inotropic index of functional cardiac contractility. Keywords: Left Ventricle (LV); Contractility; Inotropy; Load-Dependent and Independent; Stressed Volume; Dual Pressure Catheter. 1. Assessment of cardiac contractility using dual pressure catheter. 2. IVCO inferior vena cava occlusion, ECC excitation-contraction coupling, EF ejection fraction, TTE transthoracic echocardiography, Ea end arterial elastance, PRSW preload recruitable stroke work, IC intercept, PWV pulse wave velocity.