Evaluation of Sensibility of Noninnervated, Intraoral, Microsurgically Transferred Flaps
Research article published in Plastic and reconstructive surgery (2026)
Abstract
BACKGROUND: This study investigated sensory recovery of microvascular free flaps in the oral cavity with functional magnetic resonance imaging to assess activation in the primary sensory cortex (S1). METHODS: The study included 20 patients with sensory recovery at the flap site in the tongue or floor of mouth after ablative cancer surgery that involved unilateral resection of the lingual nerve and reconstruction with a radial free forearm flap, anterolateral thigh flap, or lower leg perforator flap without nerve readaptation between 2012 and 2019. Control nonflap and contralateral flap sites were electrically stimulated with a patient-specific, sensation-inducing voltage for 10 minutes with 30-second on/off intervals. During this process, functional magnetic resonance imaging was conducted simultaneously to assess the signal area and level in S1. RESULTS: The stimulation voltage was higher at the flap site than at the control nonflap site (6.0 versus 3.0 V; P < 0.001). The signal area activated upon stimulation of the flap and control nonflap site was located in the cortical area representing the lingual nerve. The signal level in S1 upon stimulation of the flap site was similar to that upon stimulation of the control nonflap site (3.2 versus 3.5 T; P = 0.751). CONCLUSION: Activation of the cortical area representing the lingual nerve upon stimulation of the flap site implies that sensory recovery of microvascular free flaps in the tongue and floor of mouth region involves nerve ingrowth from the remaining lingual nerve into the flap tissue.
Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.
Summary
Peer-reviewed clinical and outcomes research relevant to medicinal leech therapy and its biology. Indexed in PubMed and verified against the NCBI record.
Why This Matters for Hirudotherapy
This study used functional MRI in 20 patients to map cortical responses after intraoral microvascular free-flap reconstruction following cancer surgery that severed the lingual nerve, finding that stimulating the flap activated the same primary sensory cortex region representing the lingual nerve (signal level 3.2 vs 3.5 T at control sites; P = 0.751) despite requiring a higher stimulation voltage (6.0 vs 3.0 V; P < 0.001), implying sensory recovery via nerve ingrowth from the remaining lingual nerve. For ASH, the relevance is contextual rather than direct: free-flap reconstruction is the FDA-cleared (510(k) K040187) indication where medicinal leeches relieve venous congestion to salvage flaps, and evidence that these flaps can regain meaningful sensory function underscores why protecting flap viability in the early postoperative window matters. The honest caveat is that this is a small observational imaging cohort that studied neither leeches nor venous congestion, so it speaks only to the long-term reconstructive picture, not to hirudotherapy efficacy.
Citation
Evaluation of Sensibility of Noninnervated, Intraoral, Microsurgically Transferred Flaps.
Modabber et al. · Plastic and reconstructive surgery, 2026
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