Abstract
Transseptal puncture (TSP) is a critical step in left atrial appendage closure. This consensus document reviews the evolution of TSP techniques and instrumentation, comparing conventional mechanical methods with radiofrequency-assisted approaches. It highlights the importance of imaging-based preplanning with transoesophageal echocardiography and multislice computed tomography to optimize TSP positioning and procedural outcomes. The inferoposterior fossa ovalis position is generally preferred to achieve coaxial device alignment and enhance safety and efficacy, whereas alternative TSP positions may suit better specific complex anatomies. Procedural guidance under transoesophageal echocardiography and intracardiac echocardiography-guidedosto TSP is illustrated, and a stepwise strategy for challenging cases is outlined. We propose an algorithm for TSP preplanning and intraprocedural guidance, along with expert consensus recommendations developed during the second European Left Atrial Appendage Club meeting.
Keywords: left atrial appendage closure, preplanning, transseptal puncture
Introduction
Left atrial appendage closure (LAAC) is performed to reduce the thromboembolic risk in patients with atrial fibrillation. Currently available percutaneous LAAC devices are delivered via transvenous femoral access, crossing the interatrial septum (IAS) into the left atrium and appendage. Transseptal puncture (TSP) is a pivotal step in LAAC, requiring deliberate planning and execution to achieve safe and well-aligned device deployment within the native left atrial appendage (LAA) anatomy.
In this study, we review (1) the available devices for TSP, (2) the importance and methodology of preprocedural planning, (3) intraprocedural imaging guidance, and (4) strategies for challenging scenarios. We also summarize consensus statements discussed at the second European Left Atrial Appendage Club meeting and propose an algorithm for systematic TSP preplanning and performance.
Currently available devices for TSP
TSP has been performed for several decades in various interventional settings, including electrophysiology, transcatheter valve therapies for left-sided heart valve disease, and LAAC procedures. Despite its application in these highly specialized procedures, the basic technique and standard TSP instrumentation have remained unchanged for many years. A classical TSP for LAAC is performed by applying mechanical pressure to a sharp needle at the right atrial side of the IAS. Once across the septum, a transseptal sheath is advanced over the transseptal needle into the left atrium, after which the exchange for any LAAC device delivery catheter can be performed over a stiff guidewire. The most common types of transseptal sheaths and needles, each with its different curvatures, are shown in Figure 1. Radiofrequency (RF)-assisted TSP is an alternative to mechanical TSP and allows for smooth penetration and crossing of the IAS, avoiding uncontrolled mechanical forces.1 RF energy can either be delivered via a surgical electrocautery generator onto the classic transseptal needle or with dedicated TSP devices incorporating the RF energy capacity. The most widely used system is the Versa Cross system (Boston Scientific), which combines RF-assisted puncture with a preshaped guidewire and delivery sheath to reduce the number of exchange maneuvers. An overview of different novel TSP devices is given in Supplemental Table S1. In general, these devices can be categorized according to their mode of puncture (mechanical vs RF-assisted), and their approach to enhance anatomical precision (steerable vs nonsteerable). Many of these innovations incorporate promising features aimed at enhancing the accuracy and safety of the TSP. However, further investigation is required to validate their efficacy, and their adoption into clinical practice may face challenges related to cost and local regulatory requirements.
Figure 1.
Transseptal sheath and needle. (A) Superior left transseptal sheath, SL0, SL1, and SL2 present with different curvatures. (B) Mullins sheath with dilator. (C) BRK and BRK-1 Transseptal Needle (XS, extra sharp).
Preplanning of TSP
Imaging-based preplanning of LAAC procedures is essential to assess technical feasibility, identify anatomical challenges, and define procedural strategies. During this preplanning of the LAAC procedure, special attention should be paid to the TSP strategy, which can be performed using transesophageal echocardiography (TEE) and/or multislice computed tomography (MSCT). Both modalities provide a 3-dimension (3D) anatomical understanding of the fossa ovalis within the IAS, the LAA, and their orientation relative to each other. TEE allows accurate assessment of the size and mobility of the fossa ovalis and the presence of patent foramen ovale or any other septal defects while also providing insight into the size of both atria. Although MSCT provides less information about these intrinsic IAS challenges, it can also identify septal defects and offers valuable information on the IAS and fossa orientation within the thorax and relative to the LAA.
Tailored positioning of the TSP site is crucial for optimizing the efficacy, safety, and procedural simplicity of LAAC procedures. The TSP site should be strategically positioned to enable direct and coaxial engagement with the LAA. Proper alignment of the LAAC device with the native anatomical axis of the LAA is essential to ensure complete appendage occlusion, minimizing the risk of peridevice leakage and potential thrombus formation. Peridevice leakage is more frequently associated with not only undersized devices but also noncoaxial deployment of the LAAC device, whereas the risk of device thrombosis is higher with deep device implantation.2,3 Both are considered risk factors for ischemic events and should therefore be avoided. In addition, the more coaxially the LAA delivery system engages the appendage, the easier it is to implant the LAAC device, reducing the need for device recapture and/or septal repuncture. Easier implantation can be argued to improve safety and reduce radiation and contrast exposure. The introduction of newly developed steerable sheaths can help finetune device alignment, but steerability cannot compensate for significant TSP location offsets.
The optimal location of the TSP depends on the spatial relationship between the fossa, the ostial LAA location, and the proximal LAA orientation. Creating a virtual grid within the fossa along the anterior-posterior and inferior-superior axes is used to define the optimal TSP during imaging-based preplanning and can be translated during the imaging-guided TSP itself.
Studies suggest that a typical inferior and posterior TSP is ideal for 45% to 80% of LAAC procedures.4, 5, 6, 7 However, for anatomies with a more posteriorly oriented proximal LAA axis (eg, “reverse chicken-wing”), a more central or even anterior TSP location is advised (Figure 2). Conversely, a superior TSP location is rarely preferred.4, 5, 6, 7 In line with this, the use of an incidental patent foramen ovale as an access route for LAAC is discouraged as its anterosuperior location does not support proper coaxial alignment of the LAA device.
Figure 2.
The optimal TSP position (dashed arrow). (A) A posterior TSP location is favorable in case of anterior bend of the proximal neck of the LAA; (B) a more central to anterior TSP location is favorable when there is a reverse or posterior orientation of the proximal LAA. The left circumflex artery is located anteriorly of the LAA, as seen on MSCT images. LAA, left atrial appendage; LCx, left circumflex artery; TSP, transseptal puncture.
A stepwise MSCT-based approach to determine the optimal TSP position was described by Fukutomi et al,4 assessing anterior-posterior and superior-inferior positions using lateral (RAO) and apical (LAO) angiographic views of the left atrium (Figure 3). In the LAO view, the fossa’s superior and inferior borders become separated, whereas the RAO view delineates its anterior and posterior borders. In their series, a posterior TSP was favored in ∼75% of cases, whereas central and anterior punctures (17% and 8%, respectively) were mainly required in anatomies where the proximal bend of the LAA was oriented posteriorly, such as in the so-called “reverse chicken-wing” configuration.
Figure 3.
3D MSCT-based preplanning for optimal TSP position. An angiographic view of the left atrium and appendage is reconstructed to define the optimal TSP position along the anterior-posterior and inferior-superior axes. The TSP position should be chosen where it aligns best with the proximal axis of the appendage. (A) First, in an RAO or lateral view, the optimal TSP position along the anterior-posterior axis can be identified. (B) Second, in an LAO apical view, the optimal TSP position along the superior-inferior axis can be identified. LAO, left anterior oblique; MSCT, multislice computed tomography; RAO, right anterior oblique; TSP, transseptal puncture.
MSCT analysis can be performed with any software supporting multiplanar reconstruction, as is shown in Figure 4. As a first step, scrolling from anterior to posterior while observing the axial, coronal, and sagittal planes helps determine the shape and orientation of the LAA. Next, the crosshair is positioned at the LAA ostium, with one plane passing through the coumadin ridge and another through the circumflex artery, which lies anterior of the LAA. In this view, the proximal LAA axis can be defined by connecting the center of the LAA ostium to the center of the LAA landing zone, either being predominantly anterior (<90°) or posterior (≥90°). Alternatively, dedicated MSCT software for LAAC preplanning, such as 3Mensio (3Mensio Medical Imaging BV), TruPlan (Boston Scientific), or FEops (FEops/Materialise), can facilitate this process. These platforms allow easy visualization of the fossa ovalis and LAA axis, assessment of their spatial relationship in LAO and RAO projections, and simulation of delivery sheath trajectories from different puncture sites to identify the optimal TSP location.
Figure 4.
Stepwise MSCT-based assessment of TSP location with multiplanar reconstruction. Step 1, Scroll anterior to posterior through axial, sagittal, and coronal planes to determine LAA orientation. Step 2, place the crosshair at the LAA ostium—1 plane through the coumadin ridge and another through the circumflex artery (red∗), align the crosshair to the virtual center line, the short-axis view of the LAA ostium becomes visible. Step 3, connect the center of the ostium to the center of the landing zone to view the proximal LAA axis and assess anterior versus posterior bend and assess if this angle is predominantly anterior (<90°) or posterior (≥90°). LAA colored in light blue.
As MSCT may be contraindicated for contrast usage or may not be readily available due to limited resources, waiting lists, or reimbursement policies, TEE can also be used to assess and determine the optimal TSP position. A combination of 2-dimension and 3D TEE images distinguishes the anatomy of the fossa ovalis, the shape and position of the appendage, and its orientation. 3D TEE views that help determine the optimal TSP position are shown in Figure 5. The optimal TSP position is determined based on 3D reconstructions that include the fossa, the left atrium, and the LAA. First, a 3D view of the anatomical spatial relationship between the fossa and the LAA ostium within the left atrium is visualized, and second, the orientation of the proximal neck of the LAA is revealed by “cutting” through the roof of the appendage. The latter 2, like MSCT preplanning, show that a more posterior position of the TSP is favorable in the case of an anterior position of the LAA and/or an anterior proximal bend of the LAA.
Figure 5.
3D TEE-based preplanning for optimal TSP position. A 3D view of the fossa (dashed red line) and the LAA ostium (white arrow) within the left atrium is reconstructed to define the optimal TSP position along the anterior-posterior axis. (A, B) First, the LAA position within the left atrium and their spatial relation is visualized. The LAA can vary from a more posterior (A) to a more anterior (B) location in the left atrium. (C) Second, the proximal orientation of the LAA is revealed by “cutting” through the roof of the appendage. In case (A), a mid-TSP position could be preferred, whereas in cases (B) and (C), a more posterior puncture is favorable, as indicated by the red arrow. LAO, left anterior oblique; MSCT, multislice computed tomography; RAO, right anterior oblique; TSP, transseptal puncture.
Both MSCT and TEE provide the 3D information needed to assess the spatial relationship between the TSP location and appendage orientation. The consensus of the meeting was that at least 1 form of 3D multiplanar reconstruction—either 3D TEE or MSCT—is essential for preplanning LAAC, including TSP positioning and LAA sizing. A structured algorithm for this analysis should be developed for both imaging modalities.
Consensus statement for preplanning of TSP
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Image-based preplanning of LAAC procedures is recommended to preemptively assess technical feasibility and challenges and define the preferred procedural strategy.
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Preplanning should include at least 1 3D imaging modality, such as MSCT or 3D TEE, to accurately assess the fossa ovalis, the LAA, and their orientation relative to each other.
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The location of the TSP should be tailored to optimize alignment between the LAAC delivery catheter and the native LAA anatomical axis, thereby improving safety and reducing procedural complexity.
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An inferior TSP position is recommended for all LAAC procedures.
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A posterior TSP position is preferred for the majority of LAAC procedures. However, a mid- to anterior TSP position should be considered if the proximal neck of the LAA is directed more posteriorly.
Intraprocedural TSP imaging guidance
In general, TSP for LAAC procedures is recommended to be performed under ultrasound and fluoroscopic guidance for (1) routing toward the intended TSP position and (2) tracking needle movements (eg, fossa perforation and position in the left atrium). The most common practice is the use of a standard TEE probe in general anesthesia. The smaller introducer profiles of mini- and micro-TEE probes allow LAAC procedures to be performed under local anesthesia with conscious sedation. Modern types of mini- or micro-TEE probes also allow the construction of qualitative multiplanar views. Alternatively, LAAC can be performed using intracardiac echo (ICE). The advantage of using ICE is that it creates the possibility to perform LAAC under local anesthesia and serves as a valuable alternative when esophageal intubation is contraindicated. The ICE probe is introduced via an 8-10 F femoral venous access and has shown significant improvements in image quality, with some manufacturers nowadays offering 3D imaging. In comparison to TEE, the spatial resolution of ICE images is high, and it offers the most detailed images of the extreme inferior border of the fossa ovalis, which can be important when an extremely inferior TSP location is warranted. However, it should be noted that the handling of ICE catheters and the interpretation of images require additional training.
Standard views and manual handling with TEE and ICE for TSP guidance are illustrated in Figures 6 and 7. Both imaging modalities should identify first the “height” of the TSP position along the superior-inferior axis, and second, the anterior-posterior position, to move toward the predefined optimal TSP location on this axis. In TEE, 2 main views are used: (1) the bicaval view (at 90°-110°), which allows for orientation in the superior-inferior direction, and (2) the short-axis view (at 30°-60°), which allows for orientation in the anterior-posterior direction (Figure 6). Both views can be displayed simultaneously in a biplane format. With ICE, 2 standard views must also be constructed: with the ICE catheter positioned in the right atrium (1) a clockwise rotation and retroflex motion from the right atrial home view reveals the IAS, indicating the superior-inferior axis, and (2) a manual rotation of the ICE catheter gives information about the anterior (counter-clock) to posterior (clockwise) parts of the fossa ovalis (Figure 7). By rotating the ICE catheter, the nearby structures seen in the far field of the ultrasound beam will help indicate the orientation of the ICE catheter. The aortic valve or aorta can be identified in the anterior aspect of the fossa, while moving toward the posterior (ie, a clockwise rotation), the LAA and pulmonary veins become visible in the far field. Once the optimal TSP position is reached with the transseptal sheath, the image of the TEE or ICE catheter is fixed at this location, and the puncture is attempted with clear visualization of tenting and penetration of the fossa ovalis tissue with the transseptal needle.
Consensus statement for intraprocedural TSP imaging guidance
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TSP in LAAC procedures should be performed under real-time fluoroscopic and ultrasound imaging (TEE or ICE) to minimize complications and ensure a targeted TSP.
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Standardized imaging protocols for TEE and ICE should be developed and adopted to ensure a consistent and stepwise TSP in LAAC procedures.
Figure 6.
TEE procedural guidance for TSP. (A) First, the superior-inferior axis is assessed at a bicaval view (90°-110°). (B) Second, the anterior-posterior axis is visualized in the short-axis view (30°-60°). AV, aortic valve; IVC, inferior vena cava; LA, left atrium; RA, right atrium; RV, right ventricle; SVC, superior vena cava; TSP, transseptal puncture; TV, tricuspid valve.
Figure 7.
ICE procedural guidance for TSP. The ICE catheter is positioned in the right atrium at the “home view” where the TV and right ventricle are shown from the right atrium (A). A retroflex motion from the right atrial home view reveals the IAS, indicating the superior-inferior axis for the TSP. A manual rotation of the ICE catheter shows the anterior (counter-clock) to posterior (clockwise) parts of the fossa ovalis with the nearby structures seen in the far field of the ultrasound beam indicating the orientation of the ICE catheter. The aortic valve or aorta can be identified in the anterior aspect of the fossa (B) while moving toward posterior (ie, a clockwise rotation), the LAA (C), and pulmonary vein bifurcation (D) become visible. Ao; aorta; AV, aortic valve; CS, coronary sinus; ICE, intracardiac echocardiography; IVC, inferior vena cava; LA, left atrium; LAA, left atrial appendage; LLPV, left lower pulmonary vein; LUPV, left upper pulmonary vein; LV, left ventricle; MV, mitral valve; RA, right atrium; RV, right ventricle; SVC, superior vena cava; TSP, transseptal puncture; TV, tricuspid valve.
Strategies in complex TSP scenarios
Several intrinsic and extrinsic factors can complicate TSP (Table 1). Extrinsic factors alter the orientation of the IAS or its pathway toward the fossa ovalis, affecting the spatial relation between cardiac and noncardiac structures and hindering access and orientation of the TSP kit at the fossa ovalis. Intrinsic factors, on the other hand, influence the transseptal crossing due to specific characteristics of the fossa itself. Although some of these complicating factors can be identified during preplanning based on TEE and/or MSCT imaging, specific challenges during TSP are not always as easy to predict. Therefore, it is important to follow a stepwise approach to address unexpected challenges during the procedure and have a basic toolkit available.
Table 1.
Intrinsic and extrinsic factors that can complicate transseptal puncture.
| Intrinsic factors | Extrinsic factors |
|---|---|
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COPD, chronic obstructive pulmonary disease; IAS, interatrial septum; IVC, inferior vena cava.
In cases with intrinsic challenges such as a floppy, thickened, or fibrotic septum, achieving anatomical precision during TSP can be challenging. This may lead to uncontrolled penetration forces, which can result in adverse safety events. Pressure monitoring or a radiopaque coronary wire inside the TSP needle can help identify when the tip of the needle crosses the septum into the left atrium. At this point, a coronary wire can be advanced through the needle and guided toward the left upper pulmonary vein. Alternatively, the stiff back end of a coronary wire or the TSP stylet can be used to puncture a solid fossa, as they are sharper than the conventional TSP needle. A more controlled mechanical puncture of the fossa can be achieved with the SafeSept wire (Pressure Products), or an RF-assisted puncture can be performed by delivering RF energy through the transseptal needle. Several of the novel devices previously discussed, also using RF, assist in performing a more controlled transseptal crossing (Supplemental File S1). In the rare case of a septal patch or occluder device, RF-assisted puncture may facilitate septal crossing; however, this specific technique is beyond the scope of the present consensus document. Sometimes, it can also be helpful to manually shape the transseptal sheath to achieve a more perpendicular arrival of the sheath/needle onto the fossa. For instance, in the case of a vertically oriented IAS or a very large right atrium, the transseptal sheath can be bent more toward a 90° angle. Such challenges can be assessed in advance with MSCT or TEE, allowing the operator to anticipate and prepare accordingly.
If after successful TSP, the dilator and/or delivery sheath encounters difficulty crossing the septum, septal dilatation may be required using a 4-8 mm balloon over a coronary 0.014-inch or stiff 0.035-inch wire.8 Balloon-assisted advancement of the sheath has also been described to facilitate crossing of the septum with the delivery sheath.8
If extrinsic factors such as vessel tortuosity or musculoskeletal abnormalities complicate TSP, a long 16-18 French sheath can provide more controlled support at the access site. In rare cases, when femoral access is unavailable due to obstruction of the inferior caval vein, severe thrombosis or venous anomalies, alternative TSP approaches, including the transhepatic and transjugular routes, have been described but are outside of the scope of this paper.
Consensus statement for strategies in complex TSP
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A consistent stepwise protocol and toolkit should be available to tackle challenging TSP in LAAC procedures.
Limitations
The recommendations presented herein were initially formulated at the first European Left Atrial Appendage Club meeting in 2024 and subsequently refined through expert discussion at the 2025 meeting. They represent the collective consensus of experienced operators rather than evidence-based guidelines, as current data remain insufficient to confirm a causal relationship between TSP positioning, LAAC safety, and closure efficacy. This consensus therefore serves as a foundation for future studies designed to investigate these relationships in a systematic and evidence-driven manner.
Conclusion
TSP is a commonly performed procedure, with reliable outcomes using the traditional tools. Novel technologies aim to facilitate TSP and improve its anatomical precision. Tailoring the position of the TSP in LAAC procedures is crucial for achieving coaxial engagement and deployment within the native LAA anatomy, potentially improving safety and efficacy while reducing procedural complexity.
An algorithm is proposed (Central Illustration) for (1) preplanning by first identifying factors that can complicate TSP and second defining the optimal TSP position and (2) intraprocedural imaging guidance for correct TSP position and a stepwise technical approach in case of challengingS TSP anatomies. Validation of this algorithm is required.
Central Illustration.
A stepwise algorithm to prepare and perform TSP in LAAC. LAA, left atrial appendage; MSCT, multislice computed tomography; RF, radiofrequency; TEE, transesophageal echocardiography; TSP, transseptal puncture.
Acknowledgments
The authors thank Biotic Artlab for helping with the illustrations in Figures 5 and 6.
Declaration of competing interest
Liesbeth Rosseel: Honoraria for lectures − Boston Scientific, Medtronic. Institutional scientific grant − Medtronic. Nina C. Wunderlich: Travel expenses and honoraria for lectures − Abbott, LifeTech, Boston Scientific, Philips, Siemens, GE. Sergio Berti: Proctor for Edwards Lifesciences and Boston Scientific. Adel Aminian: Proctor and consultant for Abbott and Boston Scientific. Jens Erik Nielsen-Kudsk: Institutional research grants from Abbott, Boston Scientific, and Conformal Medical. Mony Shuvy; Proctor and consultant for Abbott and Edwards Lifesciences. Philippe Garot: Proctor and consultant for Abbott, Boston Scientific, and Biosensors. Speaker fees from Cordis and Terumo. Medical director and shareholder of Cardiovascular European Research Center (CERC), Massy, France. Ole De Backer: Institutional research grants and consulting fees from Abbott, Boston Scientific, and Eclipse Medical. The remaining authors do not have any conflict of interest to declare.
Funding sources
This work was not supported by funding agencies in the public, commercial, or not-for-profit sectors.
Ethics statement and patient consent
This research was conducted in accordance with applicable ethical guidelines. No patient consent was required, as no individual patient data or study subjects were included in this consensus document.
Footnotes
To access the supplementary material accompanying this article, visit the online version of the Journal of the Society for Cardiovascular Angiography & Interventions at 10.1016/j.jscai.2025.104190.
Supplementary Material
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