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.

Resection of extensive segments of inferior vena cava without reconstruction in the treatment of renal carcinoma with inferior vena cava tumor thrombus: A case report.

We present a 55-year-old male patient with right renal carcinoma with long inferior vena cava (IVC) tumor thrombus who underwent robot-assisted laparoscopic radical nephrectomy with extensive IVC resection and left renal vein ligation. The patient had a history of hematuria only prior to admission. Our case involved resection of the entire abdominal segment of the IVC and left renal vein without reconstruction. Unfortunately, the patient passed away over a year after the surgery due to brain metastasis.

A prospective observational study to compare and evaluate delta down, aortic velocity time integral variability, and superior vena cava collapsibility index as predictors of fluid responsiveness in patients with supratentorial brain tumors undergoing elective neurosurgery.

Background: Patients undergoing surgical resection of brain tumors frequently exhibit a spectrum of hemodynamic fluctuations necessitating careful fluid management. This study aimed to evaluate the feasibility of dynamic predictors of fluid responsiveness, such as delta down (DD), aortic velocity time integral variability (VTIAoV), and superior vena cava collapsibility index (SVCCI), in patients undergoing neurosurgery for brain tumors. Methods: In this prospective study, 30 patients scheduled to undergo elective neurosurgery for brain tumor resection were enrolled. Baseline measurements of vitals, anesthetic parameters, and study variables were recorded post-induction. Subsequently, patients received a fluid bolus of 10 mL/kg of colloid over 20 min, and measurements were repeated post-loading. Data were presented as mean ± standard deviation. The normally distributed continuous variables were compared using Student's t-test, with P < 0.05 considered statistically significant. The predictive capability of variables for fluid responsiveness was assessed using Pearson's coefficient analysis (r). Results: Of the 30 patients, 22 were identified as volume responders (R), while eight were non-responders (NR). DD >5 mmHg effectively distinguished between R and NR (P < 0.001), with a good predictive ability (r = 0.759). SVCCI >38% differentiated R from NR (P < 0.001), with excellent predictability (r = 0.994). Similarly, VTIAoV >20% was also a good predictor (P < 0.05; r = 0.746). Conclusion: Our study revealed that most patients undergoing surgical resection of brain tumors exhibited fluid responsiveness. Among the variables assessed, SVCCI >38% emerged as an excellent predictor, followed by VTIAoV >20% and DD >5 mm Hg, for evaluating fluid status in this population.

Intravenous misplacement of the nephrostomy catheter into the inferior vena cava and secondary thrombosis following percutaneous nephrostolithotomy: A case report and literature review.

Nephrostomy catheter misplacement into the inferior vena cava after percutaneous nephrolithotomy is an extremely rare complication, and subsequent catheter-related thrombosis has been more rarely reported. Here, we report a rare case of nephrostomy catheter misplacement after percutaneous nephrolithotomy. During the procedure, due to bleeding upon establishing the puncture channel, a renal fistula catheter with a balloon was inserted to facilitate hemostasis. However, the catheter inadvertently migrated into the inferior vena cava, with the inflated balloon obstructing venous return, resulting in thrombosis formation within the inferior vena cava. The patient was urgently transferred to our hospital for intervention. Upon administering anticoagulation and antimicrobial therapy, we first placed a filter in the patient's inferior vena cava to prevent thrombus embolism to the pulmonary arteries during catheter removal. Under fluoroscopy, the catheter was withdrawn into the renal vein, followed by catheter-directed thrombolysis and thrombus aspiration. Eventually, the renal fistula catheter was gradually removed in stages without any bleeding and pulmonary embolism occurring throughout the treatment process. Through a review of relevant literatures, we analyzed the reasons for catheter misplacement and summarized the associated treatment experience.

Comparative analysis of dual immune checkpoint inhibitor combination therapy versus immune checkpoint inhibitor plus tyrosine kinase inhibitor combination therapy for renal cell carcinoma with inferior vena cava tumor thrombosis.

BACKGROUND: Whether immune checkpoint inhibitor (ICI) plus ICI combination therapy or ICI plus tyrosine kinase inhibitor (TKI) combination therapy is useful for renal cell carcinoma (RCC) with inferior vena cava tumor thrombosis (IVCTT) remains unclear. METHODS: We retrospectively evaluated the therapeutic effects and incidence of treatment-related adverse events (TRAEs) associated with ICI-based combination therapy in 36 patients with advanced RCC with IVCTT. RESULTS: The median age at initiation of treatment was 71 years; the IVCTT stages were cT3b in 22 patients and cT3c in 14. The ICI-ICI and ICI-TKI groups comprised 15 and 21 patients, respectively. Median tumor shrinkage at the best response showed that the primary tumor diameter decreased by 1.8 cm (22%), and the IVCTT height decreased by 1.5 cm (26%). A higher proportion of patients in the ICI-TKI group experienced tumor shrinkage than those in the ICI-ICI group (primary tumor, p = 0.0325; IVCTT, p = 0.0112). Approximately 27% of patients experienced an increase in the IVCTT height with ICI-ICI combination therapy. No significant difference was observed in the relative tumor shrinkage of IVCTT, primary or level-down staging of IVCTT, other treatment effects, incidence of TRAEs, surgical outcomes, or prognosis between the groups. CONCLUSION: ICI-based combination therapy is effective against IVCTT and primary RCC. Although ICI-ICI is associated with a higher probability of tumor growth compared with ICI-TKI in the frequency of tumor regression, both therapies may be almost equally effective against primary RCC with IVCTT.

Usefulness of empiric superior vena cava isolation in paroxysmal atrial fibrillation ablation: a meta-analysis of randomized clinical trials.

BACKGROUND: The long-term success rate of pulmonary vein isolation (PVI) is suboptimal due to the presence of non-pulmonary vein (PV) foci that can trigger atrial fibrillation (AF) in up to 11%. Among non-PV triggers, the superior vena cava (SVC) is a major site of origin of ectopic beats initiating AF. OBJECTIVE: To compare data from randomized controlled trials (RCTs) assessing PVI + empiric SVC isolation (SVCI) versus PVI alone in terms of AF recurrence, procedure-related complications, and fluoroscopic and procedural times. METHODS: A search of online scientific libraries (from inception to April 1, 2024) was performed. Four RCTs were considered eligible for the meta-analysis totaling 600 patients of whom 287 receiving PVI + SVCI and 313 receiving PVI alone. RESULTS: In the overall population, SVCI + PVI was associated with a non-significant reduction of AF recurrence at follow-up (0.66 [0.43;1.00], p = 0.05, I2 0%). In patients with paroxysmal AF (PAF), a significant reduction of AF recurrence was related to SVCI + PVI (11.7%) as compared to PVI alone (19.9%) (0.54 [0.32;0.92], p = 0.02, I2 0%). No statistical differences were found among the groups in terms of fluoroscopic (3.31 [- 0.8;7.41], p = 0.11, I2 = 91%), procedural times (5.69 [- 9.78;21.16], p = 0.47, I2 = 81%), and complications (1.06 [0.33;3.44], p = 0.92, I2 = 0%). CONCLUSION: The addition of SVCI to PVI in patients in PAF is associated with a significant lower rate of AF recurrence at follow-up, without increasing complication rates and procedural and fluoroscopy times.

Evolving Landscape of Inferior Vena Cava Filter Utilization: A Comprehensive Bibliometric Analysis.

This bibliometric analysis scrutinizes the evolution and current challenges in the use of Inferior Vena Cava (IVC) filters, focusing on trends from 2004 to 2023. Analyzing 2470 records, we report the United States' dominant role, with over half of the studies, and a significant shift towards retrievable filters. Despite technological advancements, controversies persist regarding efficacy, safety, and retrieval issues. Our findings point to the need for refined clinical guidelines and enhanced management strategies to navigate the complex landscape of IVC filter utilization effectively.

Brachiocephalic Vein Reconstruction Following the Excision of a Large Suspicious Anterior Mediastinal Mass.

Superior vena cava syndrome (SVCS) is a clinical condition characterized by signs and symptoms resulting from the blockage or narrowing of the thin-walled superior vena cava (SVC). This obstruction can lead to significant morbidity and mortality. In this case, we report a 58-year-old patient who was diagnosed with SVCS due to a massive compressing anterior mediastinal mass leading to signs and symptoms of SVCS, including shortness of breath, dizziness, palpitations, and neck swelling, which was managed surgically by excision of the mass and reconstruction of the brachiocephalic vein using a synthetic graft.

Inferior Vena Cava Agenesis, a Forgotten Etiology of Deep Vein Thrombosis in Young Patients: A Case Report.

Agenesis of the inferior vena cava (IVC) is a rare congenital anomaly that is associated with the development of extensive collateral circulation with the aim of compensating for the inadequate return of blood to the right ventricle. This collateral circulation predisposes to the emergence of venous hypertension with stasis and thrombus formation. Most cases are asymptomatic and are diagnosed incidentally. We report the case of a 28-year-old man who presented with bilateral deep vein thrombosis (DVT) as the first manifestation of agenesis of the IVC. We decided to maintain anticoagulation for an indefinite period of time after a multidisciplinary discussion. IVC agenesis should be considered a cause of DVT in young men, with bilateral and proximal thrombosis and without other risk factors. The rarity of the condition makes its therapeutic approach complex.

Leveraging Generative Artificial Intelligence Models in Patient Education on Inferior Vena Cava Filters.

Background: Inferior Vena Cava (IVC) filters have become an advantageous treatment modality for patients with venous thromboembolism. As the use of these filters continues to grow, it is imperative for providers to appropriately educate patients in a comprehensive yet understandable manner. Likewise, generative artificial intelligence models are a growing tool in patient education, but there is little understanding of the readability of these tools on IVC filters. Methods: This study aimed to determine the Flesch Reading Ease (FRE), Flesch-Kincaid, and Gunning Fog readability of IVC Filter patient educational materials generated by these artificial intelligence models. Results: The ChatGPT cohort had the highest mean Gunning Fog score at 17.76 ± 1.62 and the lowest at 11.58 ± 1.55 among the Copilot cohort. The difference between groups for Flesch Reading Ease scores (p = 8.70408 × 10-8) was found to be statistically significant albeit with priori power found to be low at 0.392. Conclusions: The results of this study indicate that the answers generated by the Microsoft Copilot cohort offers a greater degree of readability compared to ChatGPT cohort regarding IVC filters. Nevertheless, the mean Flesch-Kincaid readability for both cohorts does not meet the recommended U.S. grade reading levels.

Correlation of Internal Jugular Vein and Inferior Vena Cava Collapsibility Index with Direct Central Venous Pressure Measurement in Critically-ill Patients: An Observational Study.

Background and aims: Prompt assessments and quick replacement of intravascular fluid are critical steps to resuscitate hypovolemic patients. Intravascular volume assessment by direct central venous pressure (CVP) measurement is an invasive, time-consuming, and labor-intensive procedure. Nowadays, bedside ultrasound-guided volume assessment of the internal jugular vein (IJV) or inferior vena cava (IVC) is commonly employed as a proxy for direct CVP.Therefore, we examined the strength of association between CVP and collapsibility index (CI) of the IJV and IVC for evaluating the volume status of critically ill patients. Methods: Bedside USG-guided A-P diameter and cross-sectional area of the right IJV and IVC were measured, and their corresponding collapsibility indices were deduced. The results of the IJV and IVC indices were correlated with CVP. Results: About 60 out of 70 enrolled patients were analyzed. The baseline clinical parameters of patients are shown in Table 1. For CSA and AP diameter, the correlations between CVP and IJV-CI at 0° were r = -0.107 (p = 0.001) and r = -0.092 (p = 0.001). Correlations between CVP and IJV-CI at 30° for CSA and diameter, however, were (r = -0.109, p = 0.001) and (r = -0.117, p = 0.001), respectively. Table 2 depicts the correlation between CVP and IVC-CI r = -0.503, p = 0.001 for CSA and r = -0.452, p = 0.001 for diameter. Conclusion: The IVC and IJV collapsibility indices can be used in place of invasive CVP monitoring to assess fluid status in critically ill patients. How to cite this article: Kumar A, Bharti AK, Hussain M, Kumar S, Kumar A. Correlation of Internal Jugular Vein and Inferior Vena Cava Collapsibility Index with Direct Central Venous Pressure Measurement in Critically-ill Patients: An Observational Study. Indian J Crit Care Med 2024;28(6):595-600.

Newly Designed, Self-Expanding Large-Bore Nitinol Stents for Symptomatic Central Venous Stenosis: Technical and Long-Term Clinical Outcome.

PURPOSE: To retrospectively analyze the technical and long-term clinical outcome of angioplasty and stenting using the Venovo™ venous stent for the treatment of malignant and benign superior vena cava (SVC) occlusive disease. MATERIALS AND METHODS: Consecutive patients treated with the Venovo™ venous stent for SVC occlusive disease were included. SVC obstruction symptoms were classified according to the Kishi score. The Wilcoxon signed-rank test was used for testing significance of changes. Technical success, defined as correct placement of the stent, completely covering and re-expanding the obstruction, between groups was tested using the Fisher exact test. Overall survival was calculated using the Kaplan-Meier method. RESULTS: Fifty-five patients underwent stent insertion for symptomatic benign (n = 13; 24%) or malignant (n = 42; 76%) SVC occlusive disease. A significant drop in Kishi score, mean 3.91 before versus mean 1.02 after the procedure (P < 0.0001), was observed. In one patient (1.8%), an additional balloon-expandable stent was needed to manage incomplete expansion of the nitinol stent. In one patient, a procedure-related lung embolic complication was noted. Early thrombotic occlusion of the stent occurred in one patient. Late symptomatic restenosis occurred in 3 patients. Overall primary stent patency and primary-assisted stent patency were 86% (95% CI 66-95) and 97% (95% CI 83-100) at 1-year follow-up and 98% (95% CI 87-100), 98% (87-100) at 2-year follow-up, respectively. CONCLUSION: In this retrospective analysis, angioplasty and stent placement using the Venovo™ venous stent is safe and clinically effective for the treatment of both benign and malignant SVC occlusive disease. Reintervention for symptomatic restenosis is rare.

Surgical and oncologic approach to leiomyosarcoma of the inferior vena cava: A case report.

Key Clinical Message: LMS of IVC needs a multidisciplinary approach. Surgical excision with free margin is the cornerstone of management. Upon case-by-case selection, adjuvant chemotherapy may play a role in better oncologic outcome. Abstract: Leiomyosarcoma (LMS) of the inferior vena cava (IVC) is a rare form of mesenchymal origin malignancy with less than 400 cases reported to date. Surgery is the mainstay of management but it requires vast experience in vascular and visceral surgery to attain a free tumor margin. Subsequent adjuvant treatment with chemotherapy and radiation remains as an area of gray zone. We report the case of a 61-year-old man with an 8-month history of abdominal pain. Upon physical examination, an ill-defined mass over the right side of the lower abdomen and bilateral lower extremity edema were detected. Abdominal ultrasound with Doppler revealed a right-side retroperitoneal mass invading the IVC with extensive venous thrombosis for which anticoagulation was initiated. Computed Tomography of the abdomen revealed a huge heterogeneously enhancing mass involving the whole length of the infrarenal IVC obstructing the IVC lumen with collateral veins draining through the paralumbar veins and inferior epigastric veins bilaterally. With a top differential of primary IVC LMS, a midline longitudinal laparotomy was performed with an intraoperative finding of a tumor arising from the infra-renal IVC which was excised. Gore-Tex graft was used to reconstruct the IVC. There was an injury to the right common iliac artery and it was repaired by end-to-end anastomosis. Histopathology confirmed a high-grade LMS of the IVC and surgical margin status was unknown. He was given adjuvant Chemotherapy consisting of Doxorubicin and Dacarbazine. He has been on follow-up at the Oncology side with a good performance status.

Transcatheter management of superior vena cava obstruction following cardiac surgery: A case report from a resource-limited set-up.

Obstruction of the superior vena cava (SVC) is a rare complication after cardiac surgery in infants and children. We present the case of an 8-year-old boy who underwent bi-directional Glenn shunt followed by takedown of Glenn shunt and complete repair for cyanotic congenital heart disease. After 4 years of surgery, the child developed features of superior vena caval (SVC) syndrome. Echocardiography and CT angiography revealed complete obstruction of SVC without any forward flow. Transcatheter intervention was performed successfully to re-canalize and stent the SVC to maintain its patency. The patient was doing well at follow-up appointments, with good laminar flow through the stent. In conclusion, transcatheter management of post cardiac surgery SVC obstruction was successful in this patient.

"Rapid Atrial Swirl Sign": A Better Tool Than the Landmark Technique for Ensuring Correct Depth of Insertion of Central Venous Catheters.

INTRODUCTION: Central venous catheters (CVCs) are widely used in the management and resuscitation of critically ill patients in emergency departments and intensive care units. Correct depth of insertion of the CVC line is important to ensure uninterrupted flow, avoid complications, and monitor central venous pressure. Transthoracic echocardiography, with contrast enhancement, has been proposed as an alternative to chest X-ray in detecting central venous line positioning with high accuracy. Nevertheless, this method is not widely used due to some previous conflicting results and the cumbersomeness of the procedure. MATERIAL AND METHODS: After approval by the Institutional Ethics Committee, this prospective observational study was carried out in patients for whom a central venous line was warranted. The study was conducted in the Intensive Care Unit of a tertiary care hospital among 150 adult patients to compare the "Rapid Atrial Swirl Sign" (RASS) technique by transthoracic echocardiography and the landmark-based technique for ensuring accurate depth of central venous line placement. RESULTS: In this study, we found that the mean depth of insertion of the CVC for the Echocardiography RASS group (E) was 12.84 cm, while for the Landmark technique group (L), it was 12.02 cm. There was a significant difference between these groups, with a p-value of <0.05. We found that the majority of patients (98.63%) in Group E had the catheter tip in Zones 1, 2, and 3, while only 66.6% of patients in Group L had the catheter tip in similar zones. The mean standard deviation for zones on chest X-ray was 1.8 for Group E and 2.26 for Group L, with a significant difference between these groups (p-value <0.05). CONCLUSION: The RASS technique is superior to the landmark technique in ensuring the correct depth of the tip of the CVC. When confirmed by chest X-ray, it was found that most patients had the catheter tip in Zone 1, 2, or 3 using the RASS technique. This confirms that the RASS technique can minimize the requirement of resources and hasten the initiation of patient management in a timely manner, unlike the landmark technique, which requires chest X-ray confirmation before use.

Heterozygosity for the Budapest 3 mutation in SERPINC1 in a family with thrombophilia and structural anomalies of the inferior vena cava.

BACKGROUND: Atresia of the infrarenal inferior vena cava (IVC) is associated with thrombophilia and antithrombin (AT) deficiency (ATD) due to homozygosity for the so-called Budapest 3 variant, c.391C > T, in the gene, SERPINC1. CASE PRESENTATION: We report on a father and his two sons that had severe thrombosis at a young age. One son had absence of, and the other had very gracile infrarenal IVC. The father had gracile vena iliaca. All had significant collateral building. AT activity was determined with four different methods and varied between moderately reduced and borderline normal values, depending on the method. While all were heterozygous for c.391C > T, the father was also heterozygous for a variant of uncertain significance in SERPINC1. CONCLUSIONS: The findings support the association between c.391C > T in SERPINC1, thrombophilia, and atresia of the IVC system and indicate that even heterozygosity for c.391C > T may contribute to such anomalies. ATD detection was hampered by the varying sensitivity of methods used for AT activity measurement.

Results of Radical Nephrectomy and Inferior Vena Cava Thrombectomy.

PURPOSE OF REVIEW: Renal Cell Carcinoma (RCC) with invasion into the inferior vena cava (IVC) is a rare and mortal condition. Patients with RCC have an average life expectancy of no more than six months, thus requiring an aggressive surgical approach. We analyze the outcomes of patients that underwent surgery at a single medical institution. RECENT FINDINGS: The analysis of recent series of successful treatment with radical nephrectomy and IVC thrombectomy shows a 5 year survival from 45 to 69%. We found in the analyzed series that the success of the treatment in these patients depends on the resection of the renal tumor and venous thrombectomy. We found that at our medical institution nephrectomy and IVC thrombectomy with primary repair have no intraoperative mortality and no pulmonary embolism. Nephrectomy and thrombectomy of IVC is a reliable approach for patients with advance RCC.