Hyaluronic Acid Filler Longevity in the Mid-face: A Review of 33 Magnetic Resonance Imaging Studies.

Background: Recent evidence challenges the conventional belief that hyaluronic acid (HA) fillers have a short lifespan of 3-12 months. This study, using extensive patient data and long-term imaging post-injection, suggests a need to reconsider refilling protocols and underscores the critical role of precise clinical photography for accurate comparisons. Methods: The study enrolled 33 patients who received HA fillers in the mid-face, excluding those with recent injections, permanent fillers, or specific medical histories. Magnetic resonance imaging (MRI) was conducted on 24 asymptomatic and nine edema-concerned patients over 2.5 years. Two blinded radiologists assessed filler presence and longevity based on requested MRI observations. Results: MRI scans confirmed HA presence in all 33 patients, with no complete dissipation observed over a 2-year period post injection. Among them, 21 had not received injections for 2-5 years, 12 for over 5 years, and some for up to 8-15 years. Varying volumes of HA were noted: mild in nine patients, moderate in 13, and severe in 11. The study reported HA longevity of up to 15 years across different products, with a 95% confidence interval of 84.47% ± 4.43%, demonstrating the persistence of cross-linked HA fillers in the mid-face. Conclusions: HA fillers remained detectable for at least 2 years in all 33 patients, with one patient showing filler longevity of up to 15 years. These findings suggest significant implications for filler management practices. Further research with larger cohorts and ongoing imaging follow-up is warranted to fully understand HA filler longevity and optimize clinical protocols.

Intramuscular pathway and fascicular characteristics of the segmental intercostal innervation to rectus abdominis.

BACKGROUND: Rectus abdominis is a muscle that is commonly used clinically as a muscle flap, especially in reconstructive surgery. Its intramuscular innervation, however, has rarely been examined in detail or accurately mapped. The purpose of this study was to use biopsied, histological specimens complemented with a staining technique to investigate intramuscular nerve connections and distribution of the rectus abdominis. METHODS: Four fresh human cadavers were included in the study and rectus abdominis was dissected bilaterally. Nerve sections innervating the rectus abdominis were biopsied and histologically processed. Sections were viewed under the microscope, and axons within each fascicle were counted using imaging software. All specimens were stained with a modified Sihler's staining technique. Intramuscular innervation was observed and the number as well as distribution was recorded. RESULTS: Macroscopically stained specimens showed that the eighth, ninth, 10th and 12th intercostal nerves innervated the eight muscle bellies of rectus abdominis. The greatest number of minor nerve branching as well as intramuscular nerve communications originated from nerve roots T9 and T10. Minor nerve branches crossed tendinous intersections to communicate with adjacent nerves and innervate adjacent muscle bellies. Nerves originating from T9 had the greatest number of nerve fascicles and the highest axon count in each cadaver. CONCLUSION: The rectus abdominis is divided into four compartments with each receiving its own independent nerve supply. Minor nerve branches crossed tendinous intersections to communicate with adjacent muscle bellies and nerves suggesting that rectus abdominis can be used as a whole in innervated free flap transfer procedures.

Reconstructive options for large back free flap donor sites.

BACKGROUND: Reconstruction of posterior thoracic and trunk defects can prove challenging even to the most seasoned surgeons. Many commonly used techniques for closing back defects include primary closure and split skin grafts. Often times, however, other techniques are needed in order to give the patient the best aesthetic and functional outcome. In this study, we focus on and evaluate donor site closure techniques for defects in the back created by harvesting scapular and parascapular flaps. METHODS: Twenty patients were operated on to remove pathologically diagnosed sarcomas using a wide local excision. The defects, ranging from 5 to 22 cm in width, were closed using donor flaps from the scapular/parascapular region. Nine donor sites were then closed primarily with wide undermining, while 11 donor sites were closed using multiple techniques, such as large transposition flaps, large rotation advancement flaps, keystone neurovascular island flaps, latissimus dorsi advancement flap and large Y-V advancement flaps. RESULTS: All recipient and donor flaps survived with good aesthetic and functional outcome. Patient satisfaction was high and only two of 20 donor site flaps required further surgery due to wound dehiscence. No other complications were seen during the follow-up period. CONCLUSION: The proposed advanced techniques for donor site closure in back defects have shown that primary wound healing can be achieved with the use of a variety of different techniques and the avoidance of the complications of a skin graft.