What Is the Optimal Timing for Dividing a Forehead Flap?
Bibliographic record
Abstract
The forehead flap is a time-honored regional flap that has been used in nasal reconstruction for centuries. The flap is traditionally divided in a second stage 3 to 6 weeks after initial flap elevation and transposition into the defect to be reconstructed. Strengths of the forehead flap include excellent success rates due to the use of a vascular pedicle and well-matched tissue type. Disadvantages include the need for a second surgery and the unwieldy time period that the patient has the flap pedicle from the eyebrow to the nose, with a negative impact on the patient's quality of life. Division of a forehead flap earlier than the standard 3 weeks is therefore a desirable goal if similar aesthetic and functional outcomes can be accomplished without compromising flap viability. Standard practice for nasal reconstruction, dating back centuries, is to divide a flap's pedicle at 3 weeks or longer. Modern nasal reconstruction philosophy also promotes a 3-week minimum for forehead flap pedicle attachment.1 Several recent studies have examined the ramifications of forehead flap division and inset at less than the 3-week interval from the first stage. In these studies, risk factors that affect wound healing and vascular ingrowth included patient comorbidities (e.g., vascular disease, diabetes, immunosuppression), tobacco (nicotine) use, history of radiotherapy, and wound or flap characteristics (Fig. 1). Somoano et al.2 reported survival of a forehead flap after an inadvertent pedicle avulsion 3 days after the initial stage. This prompted a practice of accelerated flap takedown at 1 week. In 26 patients undergoing this accelerated takedown (mean time to division of 7.2 days). They reported no complications. This included patients with underlying cartilage grafts. Of note, this was a retrospective cohort study, and patients with comorbidities thought to have a negative impact on flap survival underwent flap division at later time points at the discretion of the surgeon. Flap viability correlates directly to flap vascularization. In a prospective study, Surowitz and Most3 investigated the progression of relative perfusion of forehead flaps throughout the healing process. Using intraoperative laser fluorescence angiography, the authors reported that significant neovascularization occurs by the end of week 1. By the second week, relative perfusion exceeds the minimum required for tissue viability. Based on these findings, they support division and inset of forehead flaps at 2 weeks in patients with 1) >50% of the nasal defect with vascularized (granulation) tissue, 2) partial thickness defects, and 3) no nicotine use. Surgeons considering a shift to a paradigm of an earlier flap division may benefit from quantifying flap neovascularization. In a 2019 retrospective review of 71 patients, Abdelwahab et al.4 reported that the indocyanine green angiography (SPY Elite System; LifeCell [Branchburg NJ], Novadaq Technologies [Mississauga, ON, Canada) can effectively qualify and quantify perfusion. The system's infrared-sensitive camera can measure the perfusion of the intravascular fluorescent dye, and ensure adequate perfusion of forehead flaps among high-risk patients. They found that a longer time to flap division was associated with increased arterial flow. They admit that the small number of complications encountered in the study limited the analysis of the risk factors associated with flap failure. Increasing the power of future studies may allow for risks of earlier flap division. Finally, Calloway et al.5 demonstrated that early flap division is cost-effective when considering the positive impact of the patient returning to work (e.g., productivity, lost wages) balanced with the additional costs to the healthcare system of laser-assisted angiography. Earlier forehead flap division can have a positive influence on patient quality of life and is a cost-effective option.To shorten the time to forehead flap division, the surgeon should balance individual patient and nasal defect characteristics with the physiologic point of when the viability of the flap will not be adversely affected by the flap division. Evidence with indocyanine green angiography at the time of flap division supports safe and reliable flap division at 2 to 3 weeks in certain patients. Somoano et al. is a level 2 study. Surowitz and Most, Abdelwahab et al., and Calloway et al. are level 4 studies.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.004 | 0.010 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.003 | 0.001 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.001 | 0.002 |
| Scholarly communication | 0.003 | 0.007 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.003 | 0.003 |
| Insufficient payload (model declined to judge) | 0.006 | 0.004 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".