Transseptal Access to the Left Atrium: Tips and Tricks to Keep it Safe Derived from Single Operator Experience and Review of the Literature

Abstract

Background: Transseptal puncture (TSP) remains a demanding procedural step in accessing the left atrium with inherent risks and safety concerns, mostly related to cardiac tamponade.

Objective: Based on our own experience with 249 TSP procedures and in-depth literature review, we present our results and offer several tips and tricks that may render TSP successful and safe.

Methods: This prospective study comprised 249 consecutive patients (146 men), aged 41.6±17.4 years, undergoing TSP by a single operator for ablation of a variety of arrhythmias, mostly related to left accessory pathways (n=145) or left atrial tachycardias (n=33) and more recently, atrial fibrillation (n=70). TSP was guided by fluoroscopy alone in all patients without the use of echocardiography imaging. In addition, an extensive literature review of TSP-related topics was carried out in PubMed, Scopus and Google Scholar.

Results: Among 249 patients, 33 patients were children or young adolescents (aged 7-18 years); 14 patients were undergoing a repeat procedure. Patients with a manifest accessory pathway were the youngest (mean age 33.7±15.9) and patients with atrial fibrillation the oldest (mean age 56.0±10.8 years). A successful TSP was accomplished in 247 patients (99.2%). Two (0.8%) procedures were complicated by cardiac tamponade managed successfully with pericardiocentesis or surgical drainage. Review of the literature revealed no systematic reviews and meta-analyses of TSP studies; however, several patient series have documented that fluoroscopy-guided TSP, with various modifications in the technique employed in the present series, have been effective in 95-100% of the cases with a complication rate ranging from 0.0% to 6.7%, albeit with a mortality rate of 0.018%- 0.2%. Echo imaging techniques were employed in cases with difficult TSP.

Conclusion: Employing a standardized protocol with use of fluoroscopy alone minimized serious complications to 0.8% (2 patients) among 249 consecutive patients undergoing TSP for ablation of a variety of cardiac arrhythmias. Based on this single-operator experience and review of the literature, a list of practical tips and tricks is provided for a successful and safe procedure, reserving the more expensive and patient inconveniencing echo-imaging techniques for difficult or failed cases.

Keywords: Transseptal puncture; cardiac arrhythmias; cardiac tamponade; catheter ablation; left atrial catheterization.

Fig. (1)

A suggested sequence of steps to perform transseptal puncture (TSP) guided by fluoroscopy alone (16^o LAO/13^o cranial views) is displayed in a patient undergoing ablation of a left free wall accessory pathway: A: After withdrawing the sheath/dilator/needle assembly from the superior vena cava and observing two consecutive falls (not shown here; watch video (video is available on the publisher’s web site); also see text and Table 2 for discussion), the Brockenbrough needle (white arrow) is advanced and exposed only when one is certain that it has landed in the fossa ovalis which is located above the CS os; in steeper LAO view (not shown) the needle is directed posteriorly. Successful TSP is confirmed by withdrawing arterial blood, recording LA pressure waveform and injecting contrast dye swirling in the LA and directed toward the left ventricle. B: Then, the dilator and the sheath (white arrow) are advanced into the LA, the dilator is removed and (C) the map/ablation catheter (white arrow) is introduced through the sheath into the LA, and then steered/curved toward the atrial aspect of the mitral annulus facing the CS catheter to ablate the atrial insertion of the accessory pathway. All this process is being monitored with ECG and intracardiac recordings (D), but most importantly via continuous BP monitoring (circled P1 recording). BP = blood pressure; CS = coronary sinus (catheter); His = His catheter; LA = left atrium/atrial; RA = right atrial (catheter); RVA = right ventricular apex (catheter).

Fig. (2)

An alternative approach that provides landmarks and safely guides TSP (white arrow) and avoids aortic root injury employs a pigtail catheter introduced via the femoral artery into the aorta (panel A, black arrow), while the CS catheter delineates the lower and lateral aspect of the LA. This is followed by advancing the sheath (panel B, white arrow) into the LA and then through the sheath introducing the catheter required for the specific procedure that is planned (in this instance, PVI is to follow in a patient with AF). AF = atrial fibrillation; CS = coronary sinus (catheter); LA = left atrium; PVI = pulmonary vein isolation; RVA = right ventricular apex (catheter). Shallow LAO (14^o) fluoroscopic views are displayed.

Fig. (3)

The clinical indications for performing transseptal catheterization of the left atrium are displayed for 249 patients. AF = atrial fibrillation; APs = (left) accessory pathways; AT = (left) atrial tachycardia; cBPT = concealed bypass tracts; PFO = patent foramen ovale; WPW = Wolff-Parkinson-White (syndrome).

Fig. (4)

The figure illustrates the anatomic landmarks for a transseptal puncture. Shallow left anterior obliques views (15^o) are displayed. An angiogram of the left atrium (LA) is shown in the mid panel with a superimposed diagram. The transseptal needle (TS) has punctured the fossa ovalis (FO) and has entered the LA (left panel); a pigtail catheter indicates the position of the aorta (Ao). The LA position of the needle is confirmed with pressure recording, withdrawing arterial blood, and injecting contrast dye via the needle before the dilator and the sheath (arrows) are advanced into the LA. Another way to ensure correct LA entrance is to advance a thin wire via the needle into the left pulmonary vein (arrowhead, right panel) (outside the heart shadow). CS = coronary sinus; IAS = intra-atrial septum; LPVs = left pulmonary veins; MV = mitral valve; RPVs = right pulmonary veins; RV = right ventricle; TS = transseptal (system).