Anatomical Study of the Close Association between Latissimus Dorsi and Surrounding Muscles. How to Safely Harvest the Muscle?

Background  We suggested an easy and effective harvesting technique to avoid injury to tissues adjacent to the latissimus dorsi (LD).

Methods  Between 2007 and 2017, breast reconstruction was performed with an LD flap using the “bottom-up” technique. Medical records were retrospectively reviewed. Data on postoperative complications, results, and follow-up were obtained. Nine cadaveric dissections were performed to assess positional relationships between LD and adjacent muscles based on the ribs where relevant muscles and LD attach. Overall, 78 LD flaps were harvested without complications.

Results  Average age was 45.4 years. The mean operation time was 260 minutes. There were no abnormalities or injuries in the adjacent fascia and muscles during the flap harvest. Drains were removed at an average of 21.9 days postoperatively. In all cadavers, there was conjoined fascia between the thoracolumbar and LD fasciae. The average level of the merging point between the LD and external oblique muscle (EOM) was 8.9 to 11.1 ribs. The average level of the overlapping point between the LD and serratus posterior inferior (SPI) was 9.5 to 11.1 ribs.

Conclusions  There are three dangerous zones during LD flap harvesting. The first zone is where the conjoined fascia encompasses the LD and thoracolumbar fasciae. The second zone is where the LD merges with the EOM and the serratus anterior. The third zone is the lower part where the LD merges with the SPI and EOM. The “bottom-up” technique enables a more meticulous and atraumatic operation by beginner flap surgeons.

Identifying Preoperative Factors Associated with the Volume Discrepancy in Patients Undergoing Breast Reconstruction with the Extended Latissimus Dorsi Musculocutaneous Flap Coverage

BACKGROUND

The latissimus dorsi (LD) flap is a versatile option for breast reconstruction. However, the indications are limited because of volume discrepancy between the breast and the flap. We conducted this study to identify preoperative factors associated with the volume discrepancy in patients undergoing breast reconstruction with the extended LD flap.

METHODS

A retrospective study was performed in 69 patients (69 breasts) who underwent breast reconstruction with the extended LD flap between March 2015 and March 2018. We evaluated age, body weight, height, preoperative body mass index (BMI), postoperative BMI, breast skin defect size, breast volume, flap volume, and volume discrepancy [breast volume - flap volume].

RESULTS

Mean age, height, body weight, preoperative BMI, postoperative BMI, skin defect size, breast volume, flap volume, and volume discrepancy were 45.6 ± 7.1, 157.8 ± 0.1, 59 ± 8.1, 23.7 ± 3.2, 23.5 ± 3.3, 16.5 ± 9.3, 252.2 ± 107.1, 229.4 ± 95.6, and 32.6 ± 31.4, respectively. Spearman's rank correlation coefficients indicated significant positive linear correlations between volume discrepancy and preoperative BMI (correlation coefficient = 0.267, P = 0.027), volume discrepancy and breast volume (correlation coefficient = 0.472, P < 0.001), and between volume discrepancy and skin defect size (correlation coefficient = 0.609, P < 0.001). Stepwise multiple regression analysis yielded the following formula: predicted log volume discrepancy (ml) = 1.2891 + 0.0639 × skin defect size + 0.0025 × breast volume (R² = 0.421).

CONCLUSION

Skin defect size and breast volume were preoperative factors associated with volume discrepancy in patients who have undergone breast reconstruction with the extended LD flap. Considering these factors, we can predict the lack of volume and plan any necessary secondary procedures.

LEVEL OF EVIDENCE IV

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