ObjectiveTo master the morphological characteristics of the recurrent laryngeal nerve (RLN) and extra-laryngeal branching (ELB) in dogs, and to provide an anatomical basis for the establishment of an animal model of injury to the ELB in dogs as well as for functional studies. MethodsSix adult healthy Beagles were selected, completely dissected the thyroid gland, the full length of the cervical segment of the RLN and the ELB. Then, the location, size and morphology of the thyroid gland and the morphological features of the RLN and ELB were observed. The length of the RLN and its ELB were measured. The incidence and number of ELB and their relationship with trachea, esophagus and peripheral blood vessels were recorded. ResultsSix Beagles (12 sides) all had ELB. In 9 sides the main trunk of the RLN divided into internal and external branches on its way up into the larynx and converged before them entering the larynx. The total number of ELB was 48, and the number of branches on each side were ranging from 1 to 7. There were 38 ELB were located below the lowest level of the thyroid gland. ConclusionsThe Beagles included in this study all have ELB. The ELB were widely distributed in the cervical trachea and esophagus after branching from the internal branch of RLN. It is speculated that the ELB may be involved in the function of the cervical esophagus and trachea. In thyroid surgery, the tracheal branch and esophageal branch of the ELB should be preserved as much as possible.
Objective To evaluate the effectiveness of the innervated medial plantar flap for reconstructing soft tissue defects, particularly in the weight-bearing zone, after resection of foot tumors. MethodsA retrospective analysis was conducted on 12 patients with malignant skin and soft tissue tumors of the foot treated between October 2023 and December 2024. The cohort included 8 males and 4 females, aged 42-67 years (mean, 57.5 years). Tumor types comprised malignant melanoma (5 cases), squamous cell carcinoma (4 cases), arsenical keratosis (2 cases), and tumor-induced osteomalacia (1 case). Soft tissue defects were located in the heel weight-bearing zone in 10 cases and non-weight-bearing ankle region in 2 cases, with defect sizes ranging from 4.0 cm×3.0 cm to 6.0 cm×4.0 cm. Preoperative photon-counting CT angiography (PC-CTA) was performed to assess the medial plantar artery and its perforators. All patients underwent radical tumor resection with confirmed negative margins. The resulting defects were reconstructed using a innervated medial plantar flap incorporating sensory branches of the medial plantar nerve. The flap donor site was covered with a split-thickness skin graft harvested from the ipsilateral inguinal region. Results The operation was successfully completed in all 12 patients. All flaps survived completely without vascular compromise, partial necrosis, or total loss. Incisions healed primarily without dehiscence or infection. Minor skin graft necrosis occurred at the donor site in 3 patients, which healed within 2-3 weeks with routine dressing changes. No donor-site complications (e.g., tendon or nerve injury) occurred. Patients were followed up 2-16 months (mean, 10.3 months). At last follow-up, there was no tumor recurrence. Flaps exhibited good color and texture match with surrounding tissue, restored sensation, and all patients achieved normal weight-bearing activity. Conclusion The innervated medial plantar flap, precisely designed based on PC-CTA localization, provides reliable blood supply and effective sensory restoration. It is an ideal method for reconstructing soft tissue defects after foot tumor resection, especially in the weight-bearing heel region.