According to a study published online in Europace, a novel nitinol guidewire (SafeSept, Pressure Products) may be an alternative to transoesophageal or intracardiac echocardiogram for transseptal puncture for left atrium catheter ablation.
Investigators Wadehra et al reviewed the use of the novel transseptal guidewire, which is a 0.014 inch nitinol wire with a sharp distal tip and is in a preformed “J” shape, in transseptal punctures (the majority of which were for atrial fibrillation or atrial tachycardia ablation) between May 2008 and May 2010 at various centres. They found that, using the novel guidewire, successful left atrium access was achieved in 97.6% of patients (205 of 210 overall) and that success rates did not differ between patients who were undergoing transseptal puncture for the first time (131) and those who had previously undergone transseptal puncture (80). Additionally in 81.2% of procedures with the guidewire, left atrium access was achieved with the first pass.
Left atrium access was successfully achieved with the guidewire in 19 patients with a history of difficult transseptal puncture. Of these, nine had previously failed conventional transseptal puncture (including two who undergone transoesophageal echocardiography guidance under general anaesthesia). In a further 13 patients, in whom previous conventional transseptal puncture had been unsuccessful, left atrium access was successfully achieved with the same procedure but with the addition of the guidewire. Wadehra et al commented: “The design of the transseptal puncture guidewire with a sharp nitinol tip provides a significantly higher pressure per unit area than a conventional transseptal needle. The profile of the tip allows greater penetration through the septum and the immediate formation of a ‘J’ shape prevents injury or trauma to the neighbouring cardiac structures once it successfully crosses into the left atrium.”
Of the five patients in whom left atrium access was unsuccessful with the guidewire, Wadehra et al attributed the failure to the incorrect positioning of the transseptal apparatus on the interatrial septum “rather than a failure of the transseptal guidewire per se.”
However, Wadhera et al said that a “major limitation” of the study was that it was not a randomised control study (comparing the guidewire to standard techniques). “But, important safety and feasibility data are gathered to test the efficacy of this new technology by experienced operators and trainees in a significant and meaningful numbers of patients.” They added that a prospective randomised trial was needed to validate their study’s findings.