Characteristics of lower airway parameters in an adult Asian population related to endotracheal tube design: a cadaveric study.

The risk of endotracheal tube (ETT) placement includes endobronchial intubation and subglottic injury. This study aimed to describe the lengths of lower airway parameters related to cuff location and vocal cord markings in different adult-sized ETTs. Eighty cadavers were examined for the lengths of the lower airway, including their correlations and linear regressions with height. Thirty adult-sized ETTs from seven different brands were examined for Mark-Cuff and Mark-Tip distances. The depth of ETT placement was simulated for each brand using vocal cord marking. The mean (standard deviation) lengths from the subglottis, trachea, vocal cord to mid- trachea, and vocal cord to carina were 24.2 (3.5), 97.9 (8.6), 73.2 (5.3), and 122.1 (9.0) mm, respectively. Airway lengths were estimated as: (1) subglottis (mm) = 0.173 * (height in cm) - 3.547; (2) vocal cord to mid-trachea (mm) = 0.28 * (height in cm) + 28.391. There were variations in the Mark-Cuff and Mark-Tip distances among different ETTs. In the simulation, endobronchial intubation ranged between 2.5 and 5% and the cuff in the subglottis ranged between 2.5 and 97.5%. In summary, the lower airway parameters were height-related. ETT placement using vocal cord marking puts the patient at a high risk of cuff placement in the subglottis.

Superficial Inferior Epigastric Artery Flap: Vascular Pattern and Territory Across the Midline.

BACKGROUND: Superficial inferior epigastric artery (SIEA) flap offers a significant advantage of lower donor site morbidity over other abdominal-based flaps for breast reconstruction. However, the inconsistent anatomy and territory across the midline remains a major issue. This study aimed to investigate the SIEA and determine its pattern and territory across the midline. METHODS: Twenty cadavers were studied. Ipsilateral dye was injected to the dominant SIEA. Dissection was performed to evaluate the SIEA origin, artery and vein pattern, vessel diameter, and dye diffusion territory. RESULTS: Overall, three SIEA patterns were identified: bilateral presence (45%), ipsilateral presence (30%), and bilateral absence (25%). The territory depended on the vessel course and dominant SIEA diameter, not on its common origin from the femoral artery, at the pubic tubercle level. Regarding the midline territory (pubic tubercle level to umbilicus), SIEA (type 1a) with a diameter of ≥1.4 mm on either side supplied at least half the distance, whereas SIEA with a diameter of <1 mm was limited to the suprapubic area. CONCLUSIONS: Designing a SIEA flap island across the midline is feasible when contralateral SIEA is present to augment the contralateral territory (e.g., type 1a SIEA) or in SIEA with a common/superficial external pudendal artery origin. Preoperative imaging studies are important for confirming the SIEA system. When the diameter at the origin of the SIEA flap is larger than 1.4 mm, the blood supply to the ipsilateral and contralateral sides is sufficient to enable safe flap elevation.