ANSA PECTORALIS – ANATOMY AND APPLIED ASPECTS

Ansa pectoralis is the loop of communication between medial and lateral pectoral nerves, seen anterior to the second part of axillary artery. It carries C7 ?bres from the lateral cord to the medial pectoral nerve and supplies sternocostal part of pectoralis major muscle. Its damage can cause weakness of the sternocostal part of pectoralis major muscle. Section of the ansa pectoralis is done as a treatment modality to reduce spasm of pectoralis major after strokes. It is also used as nerve graft. There are only few articles which describe the anatomy of Ansa pectoralis. We conducted a dissection study in 36 pectoral regions of embalmed human cadavers to ?nd out the number, location, formation and branches of Ansa pectoralis. During dissection of the pectoral region, the formation of Ansa was seen to be of four different types. 72.2%(26 out of 36) was either between inferior or deep branch of lateral pectoral nerve and medial pectoral nerve or between the inferior lateral pectoral nerve and medial pectoral nerve (type A). In 6 cases (16.7%) it was between trunk of the lateral pectoral nerve and medial Pectoral nerve (type B). In 3 cases (8.3%), it was arising from lateral cord itself (Type C). In one case (2.7%) it was found to be arising from trunk and inferior branch of lateral pectoral nerve (Type D). The communicating loop was on the axillary artery in about 52.8% percentage of specimens, distal and plastered to the deep surface of pectoralis minor muscle in the 30.5% and multiple in 16.7%. The anatomy of Ansa pectoralis shows many variations. These are important while planning surgeries in pectoral region like breast augmentation, pectoral nerve blocks and harvesting pectoral nerve grafts.

Chest Well Muscle Changes after A Mestectomy Findings of Chest CT / 한국유방암학회지

BACKGROUND: Chest CT after a mastectomy in breast cancer patients is usually performed to detect recurrence or metastasis. It is essential for surgeons an radiologists to know the appearance of the chest wall in a postmastectomy state. Especially, muscle atrophies of the chest wall, such as that of the pectoralis major muscle, indicate whether the modified radical mastectomy (MRM) was properly performed or not. MATERIALS AND METHODS: We performed a retrospective analysis of chest wall changes in mastectomy patients with follow-up chest CT finding to evaluate the results of MRMs. The medical records and CT findings of chest wall atrophy for a total of 38 patients who were treated at Kangnam St. Mary's Hospital, the Catholic University of Korea, were reviewed. The mean age was 58.3 years, and the interval between operation and follow-up CT was 6.6 years. The operations performed were a radical mastectomy (RM) in 3 patients and a MRM in 35 patients: Petey in 28 patients, Auchincloss in 6 patients, and Scanlon in 1 patient. RESULTS: In the RM, muscle atrophies were noted at the m, subscapularis in 3 patients (100%), the m. serratus anterior in 2 patients (66.7%), and the m. lattisimus dorsi in 1 patient (33.3%). In MRM, the Patey and Auchincloss operations showed m. pectoralis major atrophies in 22 patients (78.8%) and 5 patients (83.3%) respectively. Additionally m. pectoralis minor atrophy was noted in all 6 patients (100%) who underwent the Auchincloss operation. However. there was no muscle atrophy in patients who received Scanlon operation. CONCLUSIONS: These results suggest that lateral pectoral nerve injury is the main cause of m. pectoralis major atrophy in a MRM. The Scanlon operation which preserves the serve by dividing the pectoralis minor m. at its origin is a suitable operation for chest-wall muscle preservation. We hope that by the future study, we can confirm the best way of preventing chest-wall muscle atrophy in MRMs.

Chest Wall Muscle Changes after a Mastectomy: Findings of Chest CT

BACKGROUND: Chest CT after a mastectomy in breast cancer patients is usually performed to detect recurrence or metastasis. It is essential for surgeons and radiologists to know the appearance of the chest wall in a postmastectomy state. Especially, muscle atrophies of the chest wall, such as that of the pectoralis major muscle, indicate whether modified radical mastectomy (MRM) was properly performed or not. METHODS: We performed a retrospective analysis of chest wall changes in mastectomy patients with follow-up chest CT findings to evaluate the results of MRMs. The medical records and CT findings of chest wall atrophy for a total 38 patients who were treated at Kangnam St. Mary's Hospital, the Catholic University of Korea, were reviewed. The mean age was 58.3 yeras, and the interval between operation and follow-up CT was 6.6 years. The operations performed were a radical mastectomy (RM) in 3 patients and a MRM in 35 patients: Patey in 28 patients, Auchincloss in 6 patients, and Scanlon in 1 patient. RESULTS: In the RM, muslce atrophies were noted at the m. subscapularis in 3 patients (100 %), the m. serratus anterior in 2 patients (66.7%) and the m. lattisimus dorsi in 1 patient (33.3%). In MRM, the Patey and Auchincloss operations showed m. pectoralis major atrophies in 22 patients (78.8%) and 5 patients (83.3%) respectively. Additionally m. pectoralis minor atrophy was noted in all 6 patients (100%) who underwent the Auchincloss operation. However, there was no muscle atrophy in patients who received scanlon operation. CONCLUSIONS: These results suggests that lateral pectoral nerve injury is the main cause of m. pectoralis major atrophy in MRM. The scanlon operation which preserves the nerve by dividing of pectoralis minor m. at its origin is a suitable operation for chest-wall muscle preservation. We hope that by the future study, we can confirm the best way of preventing chest-wall muscle atrophy in MRMs.