Axillary Submuscular Implantation of Non-Transvenous Cardioverter-Defibrillator; Lessons From a Cadaver Study
Document Type
Conference Proceeding
Publication Date
5-2024
Publication Title
Heart Rhythm
Abstract
Background: Non-transvenous implantable cardioverterdefibrillator (ICD) therapy offers life-saving therapy without using intravascular leads. Recommended ICD generator placement is in the left mid- axilla between the latissimus dorsi muscle (LDM) and serratus anterior muscle (SAM) to optimize the defibrillation threshold and cosmetic outcomes. We studied the relationship between the involved muscles and nerves to guide the incision and surgical dissection. Objective: To understand anatomical variantions for better SICD implantation techniques. Methods: We included 18 cadavers in our study; of which 12 (66.7%) were female donors and 6 (33.3%) were males. Measurements included the distance from the anterior border of the LDM to the back (A) and in relation to the anteriorposterior diameter of the chest (B) at the 5 th and 7 th rib levels. We also measured the distance from the back to where the long thoracic nerve (LTN) enters SAM relative to the 4th, 5th, and 6th ribs. Results: There was a mean distance of 7.6cm (5.6 – 10.8cm) from the back to the anterior border of LDM at the 5th rib and 7.6cm (5.4– 10.4cm) at the 7th rib. The average mean distance from the back to the anterior LDM border in both the 5th and 7th ribs combined was 7.6cm (5.5 – 1.1cm). The mean anterior-posterior diameter of the chest wall at the fifth rib was 21.5cm (18.6 – 24.8cm). The mean A/B ratio (the ratio of the distance from the back to the anterior LDM border to the anterior-posterior chest diameter) was 0.4 with a standard deviation of +/- 0.1 (range 0.27-0.45). The LTN was running anterior to the LDM border at the fourth rib level, and posterior to the LDM border at the 5th and 6th ribs level. The LTN entered the SAM at the fourth rib level in 6.6%, at the fifth rib in 46.6% and by the sixth rib in 46.6% of cadavers. No cadavers exhibited LTN extension superficial to the LDM caudal to the sixth rib. Conclusion: Our postmortem study demonstrated the variable position of the anterior LDM border, consistently posterior to the mid-axillary line, with an A/B ratio ranging from 0.27 to 0.45. Our study also highlights the proximity of the LTN in comparison to the anterior LDM border. Caution is warranted to mitigate the risk of LTN injury.
Volume
21
Issue
5S
First Page
S677
Recommended Citation
Khalil P, Hossein M, Barremkala M, Grogan J, Williamson BD. Axillary submuscular implantation of non-transvenous cardioverter-defibrillator; lessons from a cadaver study. Heart Rhythm. 2024 May;21(S5):S677. doi:10.1016/j.hrthm.2024.03.1662
DOI
10.1016/j.hrthm.2024.03.1662
Comments
Heart Rhythm Society Annual Meeting, May 16-19, 2024, Boston, MA