Imaging Photoplethysmography (iPPG) in Head and Neck Reconstructive Surgery: A Novel Technique for Noninvasive Flap Perfusion Monitoring
Research article published in Lasers in surgery and medicine (2024)
Abstract
BACKGROUND: Evaluate imaging photoplethysmography (iPPG) as a novel noninvasive technique to assess flap perfusion in head and neck free flap reconstructive (FFR) surgeries. METHODS: Intraoperative iPPG was performed in 17 patients undergoing FFR surgery. Imaging consisted of a 30-s video from which perfusion maps were extracted, providing detailed information about blood flow and pulsatility in the flap microvasculature. During each procedure, iPPG acquisitions were acquired representing distinct perfusion conditions of the flap (fully perfused/ischemic/reperfused). When possible, postoperative measurements were performed to assess flap recovery during the critical time period (3 days) and long-term follow-up (30 days). RESULTS: Perfusion maps, displaying iPPG amplitude and delay times, correlated strongly (p < 0.001) with the perfusion status of the tissue. One case of postoperative thrombosis, leading to flap failure, was identified with iPPG. After surgical revision in this case, flap perfusion was restored and confirmed by iPPG. Postoperative follow-up imaging allowed for objective visualization of flap recovery short term (3 days) and up to 30 days after the surgical procedure. CONCLUSIONS: This study shows that iPPG is suitable for objective and noninvasive assessment of flap perfusion in head and neck FFR surgery. In addition, postoperative monitoring shows potential for assessing flap perfusion in patients with increased risk of postoperative complications.
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 prospective study evaluated imaging photoplethysmography (iPPG) as a noninvasive way to map free-flap perfusion in 17 head and neck reconstruction patients; perfusion maps correlated strongly (p < 0.001) with tissue perfusion status, and iPPG detected one case of postoperative thrombosis with flap failure and confirmed restored perfusion after surgical revision, supporting its use for objective postoperative flap monitoring. This is directly pertinent to hirudotherapy because medicinal leeches are applied precisely for the venous-congestion and perfusion failures these flaps suffer, and reliable, objective perfusion monitoring is what would let a team detect congestion early and judge whether leech therapy is restoring flow. The caveat is that this is a small single-arm feasibility/validation series (17 patients) of a monitoring technology, not a trial of leech therapy — it neither evaluates nor mentions leeches, and small-cohort imaging results need larger confirmation before changing practice.
Citation
Imaging Photoplethysmography (iPPG) in Head and Neck Reconstructive Surgery: A Novel Technique for Noninvasive Flap Perfusion Monitoring.
van et al. · Lasers in surgery and medicine, 2024
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