Surface Landmarks do not Correspond to Exact Levels of the Cervical Spine: References According to the Sex, Age and Height

OBJECTIVE: A general orientation along the cervical spine could be estimated by external landmarks, and it was useful, quick and less exposable to radiation, but, sometimes it gave reference confusion of target cervical level. The authors reviewed the corresponding between the neck external landmarks and cervical levels. METHODS: Totally 1,031 cervical lateral radiographs of different patients were reviewed in single university hospital. Its compositions were 534 of males and 497 females; 86 of second decades (10-19 years-old), 169 of third decades, 159 of fourth decades, 209 of fifth decades, 275 of sixth decades, and 133 of more than seventh decades (>60 years-old). Reference external landmarks (mandible, hyoid bone, thyroid cartilage, and cricothyroid membrane) with compounding factors were reviewed. RESULTS: The reference levels of cervical landmarks were C2.13 with mandible angle, C3.54 with hyoid bone, C5.12 with thyroid cartilage, and C6.01 with cricothyroid membrane. The reference levels of cervical landmarks were differently observed by sex, age, and somatometric measurement (height) accordingly mandible angle from C1 to C3, hyoid bone from disc level of C2 and C3 to C5, thyroid cartilage from disc level of C3 and C4 to C7, and cricothyroid membrane from C4 to disc level of C7 and T1. CONCLUSION: Surface landmarks only provide general reference points, but not correspond to exact levels of the cervical spine. Intraoperative fluoroscopy ensures a more precise placement to the targeted cervical level.

Application of Leksell Stereotactic Frame Using External Landmarks in Stereotactic Surgery

OBJECTIVE: This study is designed to evaluate the usefulness of the cutaneous external landmarks in the application of a Leksell stereotactic frame for functional stereotactic surgery. METHODS: Surgical procedures included thalamotomy in 12 and pallidotomy in 4. Thalamotomy and later pallidotomy were performed in one. In application of the Leksell stereotactic frame, the authors used the cutaneous external landmarks including: (1) the pupil and the external acoustic meatus in group I, (2) the pupil and the crus of the helix in group II, (3) the lateral canthus, the crus of the helix, and inferior crura of antihelix in group III. This procedure was done for obtaining magnetic resonance(MR) images showing anterior and posterior commissure in the same axial scan. The targets were Vim for thalamotomy and GPi for pallidotomy. RESULTS: All MR images in group I, II, and III showed anterior and posterior commissures in the same axial scans except for two patients (17.7%) in group I. The MRI coordinate was accurate to localize the target within 1mm of the difference from electrophysiologic target in 76% of the patients. After surgery, a significant improvement was noticed in tremor scale and global outcome scale (p0.05). Transient postoperative complications including motor aphasia and hemihypesthesia were noticed in one each, which returned normal in 3 months. CONCLUSION: The cutaneous external landmarks are of value in applying Leksell stereotactic frame for obtaining magnetic resonance images, essentially showing anterior and posterior commissure. This method is also useful in saving total operation time, making patients comfortable, as well as cost effectiveness.

A New External-landmark Technique of Right Internal Jugular Vein Cannulation / 대한마취과학회지

BACKGROUND: Central venous cannulation is one of the important parts of anesthetic management. Because general anesthesia causes external-landmarks (e.g. sternocleidomastoid muscle, carotid artery pulse) indistinct, we developed a new external landmark for internal jugular vein cannulation that can be easily detected under general anesthesia. METHODS: We cannulated the right internal jugular vein of 110 patients under general anesthesia. We used the external jugular vein and cricoid cartilage as a landmark. RESULTS: Cannulation of the right internal jugular vein was successful in 108 out of 110 patients (98.2%). Patients required an average 1.48+/-0.63 attempts. There were 2 carotid punctures (1.8%), 3 discomforts (2.7%) and no brachial plexus irritation. CONCLUSIONS: This new landmark technique has a high success rate and few complications.