Recent advances in transcatheter aortic valve implantation: novel devices and potential shortcomings

During the past years transcatheter aortic valve implantation (TAVI) has evolved to a standard technique for the treatment of high risk patients suffering from severe aortic stenosis. Worldwide the number of TAVI procedures is increasing exponentially. In this context both the transapical antegrade (TA) and the transfemoral retrograde (TF) approach are predominantly used and can be considered as safe and reproducible access sites for TAVI interventions. As a new technology TAVI is in a constant progress regarding the development of new devices. While in the first years only the Edwards SAPIEN(TM) and the Medtronic CoreValve(TM) prostheses were commercial available, recently additional devices obtained CE-mark approval and others have entered initial clinical trials. In addition to enhance the treatment options in general, the main driving factor to further develop new device iterations is to solve the drawbacks of the current TAVI systems: paravalvular leaks, occurrence of AV-blocks and the lack of full repositionability.

Transcatheter Heart Valves: Specific Characteristics and Potential Shortcomings

During the past years TAVI has evolved to a standard technique for the treatment of high risk patients suffering from severe aortic stenosis. Worldwide the number of TAVI procedures is increasing exponentially. In this context both the transapical antegrade (TA) and the transfemoral retrograde (TF) approach are predominantly used and can be considered as safe and reproducible access sites for TAVI interventions. As a new technology TAVI is in a constant progress regarding the development of new devices. While in the first years only the Edwards SAPIEN™ and the Medtronic CoreValve™ prostheses were commercial available, recently additional devices obtained CE-mark approval and others have entered initial clinical trials. In addition to enhance the treatment options in general, the main driving factor to further develop new device iterations is to solve the drawbacks of the current TAVI systems: paravalvular leaks, occurrence of AV-blocks and the lack of full repositionability.

Cerebral flow pattern monitoring by transcranial Doppler during cardiopulmonary resuscitation

We describe the transcranial Doppler pattern during a period of cardiopulmonary resuscitation in a patient undergoing a transcatheter off-pump aortic valve implantation. Transcranial Doppler of the middle cerebral artery flow was measured as a part of a separate ongoing study. The patient developed a cardiac arrest during deployment of the valve prosthesis. The incidental presence of the transcranial Doppler allowed us to assess middle cerebral artery flow during cardiopulmonary resuscitation in real time. An initial lack of a diastolic flow pattern seen with transcranial Doppler at the beginning of cardiopulmonary resuscitation led to volume loading and optimisation of the resuscitation technique. After increasing the depth of external cardiac massage, the cerebral flow pattern improved to produce sufficient diastolic flow. The transcranial Doppler provided additional information during cardiopulmonary resuscitation, which was helpful in clinical management. The use of transcranial Doppler may be helpful for other cardiac procedures where cerebral malperfusion may occur.