From Bedside to Bench: The Effect of Muscular Denervation on Fat Grafting to the Breast by Comparing Take Rate, Quality, and Longevity

Effects of Temporary and Permanent Muscle Denervation on Fat Graft Retention in the Latissimus Dorsi Muscle: An Experimental Study in Rats

BACKGROUND

In breast reconstruction with a latissimus dorsi flap, immediate fat grafting is useful for increasing flap volume. However, factors such as latissimus dorsi muscle atrophy and fat graft retention affect the volume of the reconstructed breast, and reports are inconsistent regarding treatment of the thoracodorsal nerve. This study examined how thoracodorsal nerve treatment affects the rates of latissimus dorsi flap preservation and fat graft retention using a rat model.

METHODS

Fat harvested from the inguinal region was grafted to the latissimus dorsi muscle elevated as a pedicled muscle flap on the experimental side and to the intact LD muscle on the contralateral side (control). Rats were divided into intact thoracodorsal nerve (Ni), temporary denervation (Ntd), and permanent denervation (Npd) groups (n = 8 each). Fat retention and muscle preservation rates were determined, and histological changes were analyzed postoperatively.

RESULTS

Fat retention rates did not significantly differ between the Ni and Ntd groups. Only the Npd group showed a significant decrease in fat retention rate relative to the control side (p < 0.01). The quality of the grafted fat as reflected by histological parameters was significantly lower, and the viable adipocyte area and muscle fiber preservation rate significantly decreased, in the Npd group compared to the other groups.

CONCLUSIONS

Permanent thoracodorsal nerve denervation resulted in severe muscle atrophy and a significantly decreased fat retention rate. Temporary denervation had no significant benefit, suggesting that preserving the thoracodorsal nerve may be desirable for achieving sufficient volume in latissimus dorsi flap breast reconstruction with immediate fat grafting.

NO LEVEL ASSIGNED

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Selective Denervation of Pectoralis Major Muscle Improves Cosmetic Outcome and Quality of Life in Retro-Pectoral Implant Based Breast Reconstruction

BACKGROUND

Selective pectoralis major muscle (PMM) denervation has been described in retro-pectoral reconstructions to obtain the advantages of the pre-pectoral approach. Present study compared subjective evaluations between retro-pectoral implant based breast reconstructions (IBBRs) with denervation to traditional techniques without denervation.

METHODS

In 2020, two 2 groups of patients submitted to retro-pectoral IBBR, minimum 12-month follow-up, were compared through BREAST-Q post-operative questionnaire. Group-1 included direct-to-implant or two2-stage tissue expanderTE cases with selective PMM denervation, while Group-2 similar procedures, in the same time span 2017-2019, without denervation. BREAST-Q was divided into five 5 independent scales and for each scale item responses were summed up and transformed into a score, ranging from 0 to 100, to analyze and compare the results.

RESULTS

50 patients were included both in Group1 and Group-2. Group-1 patients reported significantly higher scores in "satisfaction with the reconstructed breast" scale compared to Group-2, means-medians of 56-58 and 47-50, respectively. A trend in favor of Group-1 was recorded in the scales of "psycho-social well-being", 64-65 vs. 58-53, and "sexual well-being", 53-47 vs. 48-47, albeit not significant. Substantial equivalence was found in "satisfaction with the result overall" and "physical well-being".

CONCLUSION

PMM denervation can improve cosmetic results in retro-pec IBBRs, thus leading to better QoL. Possible pain and physical discomfort weren't caused by denervation with scores similar to non-denervated controls.