Abstract: Objective   To study the relationship between detachment and puncture site and chest wall thickness after preoperative positioning of peripheral lung nodules by CT-guided Hookwire puncture. Methods   From July 2017 to December 2021, 190 patients in our hospital underwent thoracoscopic surgery for peripheral lung nodules.All patients underwent preoperative CT-guided HOOKWIRE puncture mapping, recording the puncture site, whether the needle had fallen off, chest wall thickness, and the interval between the end of the puncture and the start of the surgery, logistic regression analysis, and receiver operating characteristic (ROC) curve analysis to explore the risk factors affecting needle fall off.  Results   Clinical data were collected for 190 patients, including 119 males and 71 females, age 22 to 78 (58.1 ± 10.2) years.There were 31 cases of shedding, with a shedding rate of 16.3%.Among them, 31 cases were detached in the medial aspect of the subscapular horn line, 15 cases were detached, with detachment rate being 48.4%; 67 cases were detached in the medial axillary line, 10 cases were detached, with detachment rate being 14.9%; 65 cases were detached in the medial axillary line of the midclavicular line, 5 cases were detached, with detachment rate being 7.6%; 27 cases were detached in the medial axillary line, 1 case was detached, with detachment rate being 3.7%; the detachment rate was highest in the subscapular horn line, with statistical significance (P<0.05) compared with other locations; the tissue thickness of the thoracic wall was (49.38 ± 6.28) mm, but the tissue thickness of the thoracic wall was (36.36 ± 7.77) mm, with statistical significance (P<0.05).The interval between puncture and operation was 73 to 98 min, with an average one of (81.99 ± 4.48) min. Conclusions   The detachment of the positioning needle is related to the thickness of the chest wall, and the proportion of detachment is significantly higher in the chest back, especially in the subscapular angle, before surgical treatment of peripheral lung nodules.In cases of peripheral pulmonary nodules with surface projections medial to the inferior scapular horn line, other methods of localization should be preferably considered.

Key words: peripheral pulmonary nodule, HOOKWIRE, localization, fall off cause