Pull-Through Buddy Wire Technique for Endovascular Thrombectomy in Patients with Acute Ischemic Stroke: Technical Note / 신경중재치료의학

Excessive tortuosity is a notable cause of failed endovascular thrombectomy for acute large-vessel occlusion stroke. Transcervical access (TCA) is a commonly proposed solution for overcoming this difficulty. However, the large-bore catheter usually used in TCA increases the risk of serious local complications. This paper presents a modified technique for TCA that uses a pull-through buddy wire (PTBW) to track a large-bore femoral guiding sheath (GS) into the carotid artery via a small carotid puncture site. The carotid puncture site can be easily managed through gentle manual compression. Two illustrative cases using this technique to deal with a large aortic arch and tortuous left common carotid artery are reported. In both cases, recanalization was achieved after successful GS placement. Using a PTBW is feasible in TCA.

Transcarotid Mechanical Thrombectomy for Embolic Intracranial Large Vessel Occlusion after Endovascular Deconstructice Embolization for Carotid Blowout Syndrome / 신경중재치료의학

Carotid blowout syndrome (CBS) is a fatal complication of head and neck cancer. Endovascular treatment, particularly deconstructive embolization, is effective for CBS, but it might result in thromboembolic events. We report the case of a 57-year-old man with underlying recurrent head and neck cancer who had CBS. The patient received endovascular embolization of the right internal, external, and common carotid arteries. Right internal carotid artery to middle cerebral artery embolic occlusion was noted immediately after the procedure, and left-sided weakness and facial palsy were found. Ipsilateral suprabulbar cervical internal carotid artery puncture was performed under fluoroscopic guidance, and rescue suction thrombectomy was successful. The patient had no significant neurological sequela. Transcarotid intraarterial thrombectomy is a reasonable method for managing postembolization large vessel occlusion, even in the neck, after irradiation.

Wavelet-based ECG compression using dynamic vector quantization with tree codevectors in single codebook.

In this paper, we propose a novel vector quantizer (VQ) in the wavelet domain for the compression of electrocardiogram (ECG) signals. A vector called tree vector (TV) is formed first in a novel structure, where wavelet transformed (WT) coefficients in the vector are arranged in the order of a hierarchical tree. Then, the TVs extracted from various WT subbands are collected in one single codebook. This feature is an advantage over traditional WT-VQ methods, where multiple codebooks are needed and are usually designed separately because numerical ranges of coefficient values in various WT subbands are quite different. Finally, a distortion-constrained codebook replenishment mechanism is incorporated into the VQ, where codevectors can be updated dynamically, to guarantee reliable quality of reconstructed ECG waveforms. With the proposed approach both visual quality and the objective quality in terms of the percent of root-mean-square difference (PRD) are excellent even in a very low bit rate. For the entire 48 records of Lead II ECG data in the MIT/BIH database, an average PRD of 7.3% at 146 b/s is obtained. For the same test data under consideration, the proposed method outperforms many recently published ones, including the best one known as the set partitioning in hierarchical trees.