Cavoatrial Junction Research Articles

Value of projectional imaging relative to cross-sectional imaging to assess catheter tip position in the superior vena cava: Evaluation of reader variability.

The assessment of correct positioning of central venous catheters (CVC) is of major concern to avoid complications.Vascular access associations have established the cavo-atrial junction (CAJ) as the most appropriate CVC tip location. Among the different chest X-ray (CXR) landmarks proposed for assessing tip position relative to the CAJ, only the pericardial reflection lies in the same plane as the vascular structures assessed. Although extensively used, CXR has been criticized for its difficulty in estimating catheter tip location.We aimed to evaluate the observer variability to determine tip positioning on CXR. CT imaging was used as a gold standard for tip identification. 107 CT scans of patients wearing port access catheter devices realized at the XXX University Hospital between January and December 2021 were retrospectively analyzed. Distance from tip to cavo-atrial junction (DCAJ) was measured on topogram projectional imaging (PJ) and axial cross-sectional imaging (CS) by 2 × 2 observers (within and between evaluations). Observational statistics were reported using a paired t-test, repeatability coefficients (RC), and the intraclass correlation coefficient (ICC), and they were displayed comprehensively using Bland-Altman plots. All ICC were >0.9, indicating excellent reliability. The mean difference between observers comparing CS and PJ was 0.13 ± 0.80 cm (P = 0.10) with outer 95% confidence limits of 1.92 cm and -2.17 cm and an RC of 1.79 cm. CXR tip-position reading remains an accurate method for determining CVC localization. However, the assessment variability on CXR is plus or minus 2 cm and should be considered. Chest X-ray (CXR) for the assessment of tip position is subject to intra-individual and inter-individual variation. On CT, the variability is solely linked to determining the cavoatrial junction (CAJ) and represented about 1 cm. On CXR, there is a twofold challenge: the correct determination of the CAJ and the accurate identification of the catheter tip, leading to a greater variability of 2 cm.In clinical practice, while considering the 3 cm anatomical zone around the CAJ acceptable, operators should be aware of the 2 cm variability resulting from CXR assessment. To account for this variability and avoid the risk of positioning the tip beyond 3 cm from the CAJ (theoretically up to plus or minus 5 cm away from the CAJ), operators should reduce the CXR-based acceptable zone to 1 cm around the CAJ. This change may impact up to thirty percent of procedures.

Protrieve Sheath embolic protection during venous thrombectomy: early experience in seventeen patients

PurposeThe Protrieve Sheath (Inari Medical; Irvine, CA) is designed for embolic protection during venous thrombectomy. This report describes experience with its use.Materials and methodsBetween November 2022 and December 2023 (13 months), seventeen patients, including nine (52.9%) females and eight (47.1%) males (mean age 58.8 ± 13.3 years, range 37–81 years), underwent deep venous thrombectomy following the Protrieve Sheath placement for embolic protection. Gender, age, presenting symptoms, procedural indications, obstructed venous segments, the Protrieve Sheath access and deployment sites, thrombectomy devices utilized, need for stent reconstruction, technical success, clinical success, adverse events (the Protrieve Sheath maldeployment or clinically significant embolic events), removed thrombi analyses, and mortality were recorded. Technical success was defined as successful deployment of the Protrieve Sheath funnel central to the thrombectomy site. Clinical success was defined as improvement in presenting venous occlusive symptoms without procedure-related venous thromboembolism.ResultsThe most common presenting symptom was extremity swelling (n = 15; 88.2%). Nine (52.9%) patients had malignant and eight (47.1%) had benign etiologies of venous obstruction. Obstructed venous segments included the inferior vena cava (IVC) and lower extremity (n = 9; 52.9%), isolated lower extremity (n = 4; 23.5%), isolated IVC (n = 2; 11.8%), thoracic central veins and superior vena cava (n = 1; 5.9%), and isolated thoracic central vein (n = 1; 5.9%). The Protrieve Sheath access sites included the right internal jugular vein (n = 15; 88.2%) for IVC and lower extremity obstructions and the right common femoral vein (n = 2; 11.8%) for thoracic central vein and superior vena cava obstructions. The Protrieve sheath funnel deployment locations included intrahepatic IVC in 13 patients (n = 13; 76.5%), suprarenal IVC in two (n = 2; 11.8%), and inferior cavoatrial junction in two (n = 2; 11.8%). Thrombectomy devices used included the ClotTriever System (Inari Medical) (n = 15; 88.2%), the InThrill Thrombectomy System (Inari Medical) (n = 4; 23.5%), the FlowTriever System (Inari Medical) (n = 2; 11.8%), the Lightning Flash 16 Aspiration System (Penumbra; Salt Lake City, UT) (n = 2; 11.8%), the Cleaner Rotational Thrombectomy System (Argon; Plano, TX) (n = 1; 5.9%), and the RevCore Thrombectomy System (Inari Medical) (n = 1; 5.9%). Ten (58.8%) patients required stent reconstruction following thrombectomy. Technical success was achieved in all patients. Clinical success was achieved in 16 (94.1%) patients. No immediate adverse events, including the Protrieve Sheath maldeployment or clinically significant embolic events, occurred.ConclusionUse of the Protrieve Sheath during large-bore venous mechanical thrombectomy resulted in favorable technical and clinical outcomes without device-related adverse events or clinically significant thromboembolic events.

Optimising central venous catheter placement by comparing cavoatrial junction position to chest X-ray landmarks: Across-sectional study using CT chest reconstruction.

Central venous catheter (CVC) tip placement guided by chest X-ray (CXR) landmarks is currently prone to inconsistency and malpositioning. This study aims to better define the relationship between the cavoatrial junction (CAJ) and selected X-ray landmarks. Chest CTs of 100 patients were retrospectively assessed. CT images were converted to a 'virtual CXR' using a digital workstation, enabling simultaneous localisation of the CAJ and evaluation of CXR landmarks. Vertical distances between the CAJ and selected landmarks were measured for each patient. Measurements were assessed for correlation with age and compared between age groups and sexes. The mean vertical distance of the following landmarks above the CAJ was found: the carina (46.2 mm), the intersection of the bronchus intermedius and the right heart border (7.6 mm) and the superior inflection of the right heart border (Sup-RHB) (13.0 mm). The maximum lateral bulge of the right heart border (Lat-RHB) was 18.4 mm below the CAJ. A new landmark: the mid-superior right heart border, defined as the mid-point between the Sup-RHB and Lat-RHB, was the closest to the CAJ, lying 2.6 mm below the CAJ. We propose that the CVC tip can be placed at the mid-superior right heart border landmark.

Feasibility of a new ultrasound guided procedure to ensure the correct position of the central venous catheter tip

BackgroundSafety of central venous catheter (CVC) placement relies on some general aspects, including selection of the right vessel, correct lumen targeting while inserting the needle, check the position of catheter tip, and post-procedure check for complications. All these four points can be guided by bedside ultrasound, but the best technique to ensure the position of the CVC tip is still uncertain. MethodsWe investigated feasibility of a novel ultrasound technique consisting of focused view of guidewire tip in the cavoatrial junction (CAJ) to calculate the CVC depth in adult patients needing CVC placement in emergency. Direct visualization of the guidewire in the CAJ was used to calculate how deep the CVC needed to be inserted. In those patients without a valid CAJ window, a bubble test in the right atrium was performed to position the CVC tip. In all cases chest radiography confirmed the CVC position. ResultsThe procedure was performed in 37 patients and CVC was correctly placed in all cases. Within the group, in 25 patients the CVC depth (21.5 ± 6.0 cm) was successfully measured. In other 11 patients the correct CVC tip position was confirmed by the bubble test. In only one case it was not possible to use ultrasound for incomplete CAJ and right atrium views. ConclusionsThis study confirms the feasibility of a new ultrasound method to ensure the correct CVC tip position. This protocol could potentially become a standard method reducing costs, post-procedural irradiation, and time of CVC placement in emergency.

Tinjauan Pustaka: Sindrom Vena Kava Superior

Superior Vena Cava Syndrome (SVCS) includes various clinical signs and symptoms due to external compression and intrinsic obstruction of superior vena cava (SVC) itself or the superior cavo-atrial junction that cause reducing of blood flow. Infection becomes main etiology in previous decades but development in antibiotics treatment and improvement of socio-economyc condition made incidence of SVCS due to infection decreased. SVCS due to malignancy recently reach 60-90% of overall cases. 78-85% of SVC obstructions due to malignancy are caused by lung cancer and 80% of it is right lesion. Historically SVCS is considered as an oncology emergency condition and become one of a few indications for palliative radiotherapy. This literature review will explain the pathophysiology, etiology, diagnosis and management of SVCS with the aim of providing timely and effective intervention to treat the causes of this syndrome so that it can significantly relieve symptoms and improve the quality of life of patients with SVCS.

Cavoatrial junction stenting in vascular hemodialysis catheter malfunction.

In patients undergoing hemodialytic treatment via intravascular catheters, stenosis or occlusion of central veins is common. Despite an extensive characterization of Superior Vena Cava Syndrome (SVCS) no data is available about CavoAtrial Junction (CAJ) stenosis. We report the case of two patients with a story of multiple catheter failures due to thrombosis or infection. Computed tomography (CT) showed radiological signs of CAJ stenosis confirmed at the following venography. In absence of other feasible options to place a vascular access, the two underwent stenting with Gore Viabahn VBX balloon expandable endoprosthesis (W.L. Gore & Associates, Flagstaff, AZ, USA) of the CAJ stenosis. Completion venography showed complete resolution of the stenosis in both patients. No complications occurred during the procedures. At a mean follow-up of 878 ± 559 days no signs of in-stent restenosis or recoil were found. The present cases emphasize the feasibility and safety of CAJ stenting, underlining the importance of preserving CAJ and upper veins patency in hemodialysis access.

A New Equation to Estimate Peripherally Inserted Central Catheter Length.

Background and Objectives: Peripherally inserted central catheter (PICC) placement plays an important role in clinical practice. This study aimed to provide an equation for the proper estimation of catheter length in cases of PICC placement without imaging guidance in relation to patient height, weight, sex, and age. Materials and Methods: For 1137 PICC placement cases in both arm veins of 954 patients at a single center, the elbow crease to the cavoatrial junction length (ECL) was calculated as follows: ECL = (PICC length) + (distance from the elbow crease to the puncture site). We analyzed the relationship between ECL and patient characteristics and suggested a new equation for ECL based on height, weight, sex, and age. Results: The average ECL was 48.0 ± 2.4 cm in the right side and 51.0 ± 3.0 cm in the left side. ECL in the right arm was significantly correlated with patient height, sex, and age, whereas the ECL in the left arm was additionally significantly correlated with patient weight. The ECL (cm) prediction model was as follows: right ECL = 26.32 + 1.33 × (female = 1, male = 2) - 0.02 × age (years) + 0.13 × height (cm); left ECL = 22.09 + 1.28 × (female = 1, male = 2) + 0.02 × age (years) + 0.14 × height (cm) + 0.042 × weight (kg). Conclusions: The appropriate PICC length was predicted based on the patient's height, weight, sex, and age. The equations in our study can help predict the optimal catheter length and can be automatically calculated using computerized patient information for bedside procedures in PICC.

Numerical Study on the Impact of Central Venous Catheter Placement on Blood Flow in the Cavo-Atrial Junction.

An in silico study is performed to investigate fluid dynamic effects of central venous catheter (CVC) placement within patient-specific cavo-atrial junctions. Prior studies show the CVC infusing a liquid, but this study focuses on the placement without any liquid emerging from the CVC. A 7 or 15-French double-lumen CVC is placed virtually in two patient-specific models; the CVC tip location is altered to understand its effect on the venous flow field. Results show that the CVC impact is trivial on flow in the superior vena cava when the catheter-to-vein ratio ranges from 0.15 to 0.33. Results further demonstrate that when the CVC tip is directly in the right atrium, flow vortices in the right atrium result in elevated wall shear stress near the tip hole. A recirculation region characterizes a spatially variable flow field inside the CVC side hole. Furthermore, flow stagnation is present near the internal side hole corners but an elevated wall shear stress near the curvature of the side hole's exit. These results suggest that optimal CVC tip location is within the superior vena cava, so as to lower the potential for platelet activation due to elevated shear stresses and that CVC geometry and location depth in the central vein significantly influences the local CVC fluid dynamics. A thrombosis model also shows thrombus formation at the side hole and tip hole. After modifying the catheter design, the hemodynamics change, which alter thrombus formation. Future studies are warranted to study CVC design and placement location in an effort to minimize CVC-induced thrombosis incidence.

Management of penetrating cardiac injury and tricuspid regurgitation with extracorporeal-membrane oxygenation (ECMO): a case report

BackgroundGunshot wounds (GSW) to the heart are lethal, and most patients die before they arrive to the hospital. Survival decreases with number of cardiac chambers involved. We report a case of a 17-year-old male who survived a GSW injury involving two cardiac chambers with acute severe tricuspid regurgitation (TR) who subsequently developed cardiogenic shock requiring extracorporeal membrane oxygenation (ECMO) support.Case PresentationA 17-year-old male sustained a single gunshot wound to the left chest, resulting in pericardial tamponade and right hemothorax. Emergency sternotomy revealed injury to the right ventricle and inferior cavoatrial junction with the adjacent pericardium contributing to a right hemothorax. The cardiac injuries were repaired primarily. Tricuspid regurgitation was confirmed immediately postoperatively. Five days after presentation, the patient developed cardiogenic shock secondary to TR requiring emergent stabilization with ECMO. He subsequently underwent successful tricuspid valve replacement.ConclusionsThis is the first report to our knowledge of successful ECMO support of severe TR due to gunshot injury to the heart.

Clinical application of ultrasound-guided totally implantable venous access ports implantation via the posterior approach of the internal jugular vein.

To determine the feasibility and safety of ultrasound-guided totally implantable venous access port (TIVAP) implantation via the posterior approach of the internal jugular vein (IJV). From September 2021 to August 2022, 88 oncology patients underwent ultrasound-guided implantation of TIVAPs via the posterior approach of the IJV for the administration of chemotherapy. The catheter tip was adjusted to be positioned at the cavoatrial junction under fluoroscopic guidance. Clinical data including surgical success, success rate for the first attempt, intraoperative, and postoperative complications were all collected and analyzed. All patients underwent successful surgery (100%), whereby 58 were via the right IJV and 30 via the left IJV, and the success rate for the first attempt was 96.59% (85/88). The operation time was 20 to 43 minutes, with an average of 26.59 ± 6.18 minutes with no intraoperative complications. The follow-up duration ranged from 1 to 12 months (mean = 5.28 ± 3.07) and the follow-up rate was 100%. The rate of postoperative complications was 4.55% (4/88), including port-site infection in two cases, fibrin sheath formation in one case, and port flip in one case. No other complications were observed during follow-up. Ultrasound-guided TIVAP implantation via the posterior approach of the IJV is feasible, safe, and effective, with a low rate of intraoperative and postoperative complications. Not only was the curvature of the catheter device smooth, but patients were satisfied with the comfort and cosmetic appearance. Additionally, we could reduce the possible complications of pinching and kinking of the catheter by using this approach. Therefore, further large-sample, prospective, and randomized controlled trials are warranted.

Different mechanisms for persistent and residual left-to-right shunt after transcatheter sinus venosus defect closure and their management.

Transcatheter closure of superior vena cava (SVC) form of sinus venosus defects (SVDs) using covered stents is emerging as an alternative to surgery in the current decade. A covered stent placed in the cavoatrial junction creates a roof for the right upper pulmonary vein (RUPV) that stops the left-to-right shunt and redirects the vein to the left atrium. While surgical literature has clearly documented the incidence of stenosis of SVC and RUPV, sinus nodal dysfunction, and persistent residual shunts following surgical correction, it is imperative to have similar data after this new transcatheter intervention on the incidence of complications and follow-up outcomes. Since patients with pretricuspid shunts are often clinically asymptomatic, correction is primarily performed to prevent a persistent right heart volume overload and allow remodeling of the heart chambers. Any residual left-to-right shunt after a correction will result in persistent right heart dilatation. Residual flows can result from various mechanisms, including lack of apposition of the covered stent to the free edge of the SVD, fabric breach, and persistent anomalous drainage of additional right-sided pulmonary veins that drain very high in the SVC or can be due to a coexistent defect in the oval fossa. This review analyzes the different mechanisms, explains the transesophageal and angiographic images for each one, and offers solutions tailored for various reasons. Different mechanisms warrant different treatment principles. A solution for residual shunt from one mechanism may not be appropriate for residual flow through another mechanism. A thorough understanding would aid the operator in effective interventions for these SVDs.

The use of extracorporeal membrane oxygenation (ECMO) for critically-ill COVID-19 patient in clinical setting: A literature review

The use of ECMO may help sustain extracorporeal life support in cases where regular less-invasive modalities failed to adequately assist the body in maintaining basic life mechanisms. Typically, VV-ECMO is used in life-threatening respiratory failure. However, experts must consider relative contraindications, answering the question: ‘Will the patient really benefit from this treatment, or will it only add emotional and economic burden, also exposing the patient to various risks of complications?’. The physiology of oxygenation within the lungs, tissues, and ECMO machine, is a modification of the basic principles of respiratory physiology. In typical VV-ECMO cannula insertion, drainage cannula is inserted via the right femoral vein percutaneously and is guided upwards through inferior vena cava with its tip 10 cm below cavoatrial junction while the reinjection cannula will be inserted through the intrajugular vein. This places the artificial lungs in series with the normal lungs rather than in a parallel form. The artificially-oxygenated blood was then returned and mixed with the native venous blood. It is important to measure maximum drainage flow to prevent shunting of the veins by setting the ECMO to the highest flow. Frequent complications include co-infection up to sepsis and coagulopathy up to complications following it. Therefore, it is always beneficial to acquire multidisciplinary judgement, particularly with hematologists, intensivists, and infectious disease specialists prior, during, and post-ECMO use.

Oclusão percutânea da comunicação interatrial do tipo seio venoso com stent coberto: a importância dos métodos de imagem para impressão de modelos tridimensionais e a melhor tomada de decisão clínica

A superior sinus venosus atrial septal defect is usually accompanied by an anomalous venous connection to a right superior or middle pulmonary vein or veins, draining directly into the superior vena cava or even into the cavoatrial junction. This is a case report of a 62-year-old female patient, diagnosed with a sinus venosus atrial septal defect, with overload of the right chambers, for whom a percutaneous occlusion procedure was planned, using a previous cardiovascular tomography and, sequentially, a three-dimensional anatomical study, with the publicly available software 3D Slicer. In addition, a resin model was printed for inspection and simulation of a stent implantation. The patient was treated percutaneously with a 60-mm covered Chetham-Platinum stent, with total occlusion of the defect, absence of residual shunts, and draining flow from the right superior pulmonary vein to the left atrium, through a posterior communication between the atria, a sine qua non prerequisite to perform this type of procedure. Planning of the percutaneous occlusion procedure of the sinus venosus atrial septal defect involves careful evaluation of imaging tests. The printing of virtual or physical models, derived from computed tomography angiography of the heart, is essential for a detailed study of the defect and associated anatomical structures, minimizing the occurrence of complications.

Images in Vascular Medicine: Valsalva purpura secondary to balloon occlusion of the cavoatrial junction during intervention for lead-induced SVC syndrome.

Images in Vascular Medicine: Valsalva purpura secondary to balloon occlusion of the cavoatrial junction during intervention for lead-induced SVC syndrome.

Simultaneous Transcatheter Closure of Coexistent Superior Sinus Venosus Defects and Oval Fossa Defects.

Device closure has become the preferred procedure for treating oval fossa defects in the last two decades. More recently, transcatheter sinus venosus defect (SVD) closure has emerged as an alternative to surgery. Transcatheter stenting aims to overcome potential late surgical complications such as stenosis of the superior vena cava (SVC) and right upper pulmonary vein (RUPV), as well as sinus node dysfunction. Balloon interrogation of the cavoatrial junction is able to identify patients who are suitable candidates for nonsurgical closure. Successful closure is possible when the balloon seals the SVD and redirects the RUPV towards the left atrium. Oval fossa (secundum) defects can coexist in approximately 9-16% of patients with SVD. Among a group of 80 patients who underwent transcatheter closure of SVD, five adult patients aged between 22 and 52years also required device closure of an associated oval fossa defect. The procedure involved simultaneous balloon interrogation of both the SVD and oval fossa defect, with continuous monitoring of the RUPV using bilateral femoral venous sheaths. Covered stent exclusion of the SVD was performed with concurrent device closure of the oval fossa defect using 12-36mm atrial septal occluders. During the procedure, two patients required protective balloon inflation in the RUPV while expanding the covered stent. In one patient, a higher small accessory RUPV was intentionally left to drain into the SVC through the struts of a bare stent anchoring the covered stent in the upper SVC. In another patient, a second overlapping covered stent was used to address residual flows from a fabric tear that became apparent after balloon deflation. There were no vascular complications and only one patient exhibited an insignificant 6mm residual flow from the caudal edge of the SVD during a follow-up of 5 to 72months. In conclusion, the closure of both SVD and associated oval fossa defects can be successfully performed in a single procedure, with comparable procedural times and favourable mid-term outcomes.

#4216 FEASIBILITY ANALYSIS OF AN ULTRASOUND-GUIDED PLACEMENT OF TUNNELED HEMODIALYSIS CATHETERS

Abstract Background and Aims Radiographic fluoroscopy (RAD) is the current standard for placement of tunneled central venous catheters (CVC) for hemodialysis. RAD requires structural and personnel infrastructure and exposes the patient to ionizing radiation. Here, we investigate the feasibility of solely ultrasound-guided placement of tunneled central venous dialysis catheters. Method We evaluated prospectively collected single center data of 134 consecutive patients who underwent CVC implantation between 2020 and 2021 regarding feasibility, safety, and catheter function. We used the inset guidewire to visualize the position of the catheter tip. In the case of inadequate visibility by ultrasound, we additionally used intracardiac ECG recording or agitated saline. A total of 1844 catheter days were assessed. As a historical control, we analyzed the position of 50 CVCs placed by RAD. Optimal CVC position was defined to be in between the cavoatrial junction (CAJ) and the right atrium (RA), according to the guidelines. Results The catheters were placed on the right side in 117 (87%) cases. The primary success rate for optimal position and function was 97,7% (n = 131). Placement solely by ultrasound was possible in 130 (97%) cases. There were no immediate procedure-associated complications related to the new technique. Effective blood flow averaged 292 +/- 39 ml/min. Of all ultrasound-placed catheters, 6% were in the vena cava superior (RAD 24%), 70% in the CAJ (RAD 60%), and 24% in the RA (RAD 16%), resulting in a rate of 94% with optimal position. Conclusion Placement of CVCs for hemodialysis solely by ultrasound is an effective and safe alternative to fluoroscopy-assisted placement.

PULM9: Development of a Novel Cannula for Durable Venovenous Extracorporeal Membrane Oxygenation

Background: Fifteen million Americans suffer from chronic obstructive pulmonary disease (COPD). After failed optimal medical therapy, the only definitive treatment is lung transplantation, which is limited due to donor scarcity. Extracorporeal membrane oxygenation (ECMO) can be used in acute exacerbations of COPD or as a bridge to transplant for waitlisted COPD patients, but it is not currently suited for long-term respiratory support. Existing venovenous (VV) ECMO configurations often utilize a dual lumen cannula that is inserted into the jugular vein and is designed for short term use. While effective, dual lumen cannulas are associated with high resistance and malposition which limits blood flow, promotes cavitation, and increases blood trauma. Furthermore, patient ambulation is cumbersome because of the difficulty of securing the dual lumen cannula safely to the patient. A novel ECMO system that provides durable respiratory support could reduce morbidity and mortality in patients and facilitate ambulatory use. To this end, a dual lumen cannula that is attached to the heart and tunneled to a more ergonomic position could provide more durable, long term ECMO support. Here, we describe our initial efforts to develop a durable VV ECMO cannula with reduced resistance. Methods: A novel cannula for long-term VV ECMO support was developed using computer aided design. The cannula is designed for surgical attachment to the right atrium with the cannula’s drainage tip at the cavoatrial junction and the reinfusion port directed towards the tricuspid valve to minimize recirculation. Pressure drop was evaluated for the novel cannula, 28Fr, and 32Fr Crescent cannulas (MC3, Dexter, MI) for comparison (N≥5) in circuits primed with deionized water at ambient temperature. A Rotaflow (Maquet, Wayne, NJ) blood pump was operated at 2700-3625 RPM, and pressure drop was assessed for flow rates between 0.1 – 5 LPM. Porcine hearts were harvested from healthy pigs and utilized for ex vivo cannula fit studies. Water flow through the cannula into the right atrium was evaluated using videography. Results: The novel cannula drainage pressure drop (-12±1.1mmHg) was similar to the 28Fr Crescent (-13± 0.3mmHg) and 32Fr Crescent (-9±0.3mmHg) at 2LPM (Figure 1). Reinfusion pressure drop was similar between the novel cannula (22±1.2mmHg) and the 32Fr Crescent (21±0.4mmHg), and higher for the 28Fr Crescent (43±0.9mmHg) at 2LPM. Total pressure drop was similar between the novel cannula (33.4±1.2mmHg) and 32Fr Crescent (29.4±0.5mmHg) and higher for the 28Fr Crescent (57±1.0mmHg) at 2LPM. In ex-vivo heart studies flow through the novel cannula was directed towards the tricuspid valve and entered the right ventricle. Conclusions: Our novel cannula possesses an excellent pressure-flow profile, comparable to the largest-bore commercially available dual lumen cannulas. This novel cannula will enhance durability and ease of use for patients requiring durable mechanical respiratory support.Figure 1. Pressure Flow Curve for Novel VV ECMO Cannula

Unrecognized Patent Foramen Ovale in Patient With Sinus Venosus-Type Atrial Septal Defect With Partial Anomalous Pulmonary Venous Return.

Unrecognized Patent Foramen Ovale in Patient With Sinus Venosus-Type Atrial Septal Defect With Partial Anomalous Pulmonary Venous Return.

Change of Peri-mitral Atrial Flutter into Single-loop Biatrial Flutter During Ablation

Anterior line ablation for peri-mitral atrial flutter (AFL) is associated with biatrial flutter due to disruption of the electrical conduction in the left atrial septum. An AFL case with valvular disease, cardiac surgery, and prior ablation was confirmed to be counterclockwise peri-mitral flutter with isthmus on the left atrial septum. Ablation on the septum of the left atrium (LA) targeting the isthmus prolonged the tachycardia cycle length (TCL) from 266 to 286 ms. Left atrial mapping during AFL with a TCL of 286 ms showed that the activation remained peri-mitral counterclockwise, but there was interruption of the local activation time (LAT) sequence. Combined mapping of the LA and the right atrium (RA) showed a counterclockwise single-loop biatrial flutter, involving the whole LA and the RA septum, with Bachmann's bundle and the posteroinferior septum being the interatrial connections. The AFL was terminated by ablation at the right superior cavoatrial junction. RA mapping should be considered if there is prolongation of TCL but without termination of the peri-mitral AFL, and if there is interruption of the continuity of the LAT sequence during AFL with a longer TCL. The biatrial flutter can be terminated by ablation targeting the interatrial connections.

Hemodialysis vascular access in prone position for critically ill patients with ARDS.

Acute respiratory distress syndrome (ARDS) is defined in critically ill patients with acute hypoxemia and positive-pressure ventilation in association with several clinical disorders including trauma, pneumonia, sepsis, and aspiration. The prone position has been used for many years and is now recommended for patients with severe or moderate-to-severe ARDS on invasive mechanical ventilation. Acute kidney injury (AKI) is a common complication in patients with ARDS, with up to a 35% incidence rate. Initiation of Kidney Replacement Therapy (KRT) requires wise clinical judgment and collaboration between nephrologists and intensivists. A properly functioning vascular access is critical for an optimized KRT. Our institute is a national referral center for respiratory diseases. We describe 11 cases of dialysis catheter placement for KRT in critically ill patients with ARDS on mechanical ventilation in prone position. The catheter was placed in the first puncture attempt in nine cases, Blood flows (Qb) achieved were 283.4 ± 20.4 ml/min during the session, in six cases the radiologic tip location was achieved in the peri cavoatrial junction; in four cases was achieved in mid to- deep right atrium. The dialysis quality standards were based on KTV and in URR; in nine cases (81.81%) KTV was in 1.3 and in all cases (100%) URR was >65%, lumen dysfunction was reported only in two cases (18.1%), but these cases did respond to mobilization maneuvers. The procedure time of placement was 29.8 min, no arterial punctures or complications were reported. We demonstrate that in our study hemodialysis non-tunneled catheter placement in the prone position is safe and effective. We believe this practice could be frequently used in the near future and represent an opportunity window for the training of interventional nephrologists and related areas.