Superficial Temporal Vessels Research Articles

The Role of CT Angiography in Designing a Hair-Bearing Superficial Temporal Artery Flap for Eyebrow Reconstruction.

The hair-bearing superficial temporal artery flap is one of the traditional options for total eyebrow reconstruction. The anatomical variation of the superficial temporal artery has been well discussed; however, the anatomy of the superficial temporal vein is highly diverse. The authors report the use of preoperative computed tomography (CT) angiography in a 27-year-old man with a total eyebrow defect caused by thermal burn injury. The authors harvested a 6×1.5-cm pedicled hair-bearing superficial temporal artery flap from the area where the parietal branches of the superficial temporal artery and vein were running in close proximity, according to the CT angiography findings. Postoperatively, the flap survived completely without any vascular compromise. The authors believe that preoperative visualization of the superficial temporal vessels with CT angiography is highly beneficial in performing safe eyebrow reconstruction with a hair-bearing superficial temporal artery flap.

Anatomie de la région frontale

The forehead is an anatomic region located between the frontal hairline cranially, the eyebrow and the glabella caudally, and the anterior border of the temporal fossa laterally on both sides. Its vertical situation, due to the telencephalon growth, is specific of the human species. From surface to deep planes, the skin and sub-cutaneous fat pads are described first. The muscular plane is constituted of the frontal muscles elevators of the forehead and the eyebrow, and the depressors which are the procerus and orbicularis oculi muscles superficially, the depressor supercilii muscle, and the corrugator supercilii in a deep plane. The galea aponeurotica, located deep to the frontal muscles, is a fibrous lamina on which the muscles of the skull insert. There is a sexual dimorphism of the frontal bone. The male forehead has extensive supraorbital bossing, and above this there is often a flat area, in teh femalethe supraorbital bossing is often nonexistent and above, there is a continous mild curvature. Blood supply to the forehead is given by an anterior pedicle constituted by the supraorbital and supratrochlear vessels and a lateral pedicle made of the anterior branches from the superficial temporal vessels. The sensory innervation of the forehead is given by the ophtalmic nerve which divides in frontal, nasociliar and lacrymal nerves. The motor innervation is given by the temporal ramus of the facial nerve which passes laterally to the zygomatic arch, and gives the innervation of the frontal, corrugator supercilii and procerus muscles.

Management of large head and neck defects in the vessel-depleted neck.

Surgery, radiation, and chemotherapy are often utilized in the treatment of head and neck cancer. These treatments can cause extensive scarring within the neck and can limit the viability of recipient vessels for further microvascular reconstruction. Patients with vessel-depleted necks provide a significant challenge for microvascular surgeons and are a topic of much discussion in the field. While reconstruction in the vessel-depleted neck is an active area of interest, the patient population is rare. Therefore, single institution series with small numbers comprise the majority of published literature. Recent publications describe techniques for identifying adequate recipient vessel options outside of the field of treatment with excellent free flap outcomes. Further, recent summary articles describe techniques for addressing issues with pedicle length that can arise when using vessels that are far from the defect to be reconstructed. When viable vessel options are available within the treatment field, these recipient vessels can be used with good reliability and free flap success. If in-field recipient vessels are not available, minimal access incisions can be used to identify superficial temporal, angular, contralateral facial, or transverse cervical vessels. Further away from the treatment field, internal mammary vessels can be harvested through open or robotic approaches. If the use of these distant vessels creates issues with pedicle length, interposition vein grafts, arteriovenous (AV) loops, or flow-through flaps can be used to augment vessel length.

Modified Scalp Replantation for Total Scalp Avulsion: Scalp-Shifting Technique.

Scalp replantation is the best treatment for scalp avulsion due to its functional and esthetic benefits. Regular scalp replantation requires only unilateral or bilateral superficial temporal vascular anastomosis. However, shear force always damages vessels in severe scalp avulsions. Short, superficial temporal vessels (STVs) make tension-free anastomosis challenging. The objective of this article is to improve the regular scalp replantation technique. When the STVs are short, tension-free anastomosis, and cosmetic symmetry can be achieved without vein grafts or vascular replacement. This study retrospectively reviewed 18 patients with scalp avulsion, of which 10 underwent scalp-shifting replantation, and 8 underwent regular scalp replantation with direct anastomosis of the STVs. Postoperatively, the authors, assessed whether there was a significant difference in the percentage of scalp survival and in the facial symmetry of patients between the 2 methods. The percentages of scalp survival and facial symmetry were good after surgeries using both methods, and no significant differences were observed. The authors use scalp-shifting replantation to create tension-free anastomoses in cases where scalp avulsion injuries have left the superficial temporal arteries too short. This technique ensures facial symmetry, scalp reimplantation survival, and equally excellent results in function and esthetics.

Pushing boundaries: Anterolateral thigh free flaps for extensive scalp defects beyond previous limits, leveraging imaging modalities with ultrasound and indocyanine green.

Scalp defect reconstruction poses considerable challenges, with ongoing debates regarding the most effective strategies. While the latissimus dorsi (LD) flap has traditionally been favored, the anterolateral thigh (ALT) flap has been well described as a versatile alternative for addressing extensive scalp defects. This study underscores the success of scalp reconstruction using ALT flaps, notably pushing the boundaries of previously reported flap sizes. Our approach leverages the use of indocyanine green (ICG) perfusion to guide precise preoperative planning and vascular modification, contributing to improved outcomes in challenging cases. We performed 43 ALT flap reconstructions for scalp defects between 2016 and 2023. We collected patients' demographic and clinical data and evaluated flap size and recipient vessels and additional surgical techniques. Detailed preoperative plans with ultrasound and ICG use for intraoperative plans were performed to find perforators location. The cohort was divided into two, with or without complications on flaps, and analyzed depending on its surgical details. This study involved 38 patients with extensive scalp defects (mean age: 69.4 ± 11 years) who underwent ALT perforator flap transfers (mean flap size: 230.88 ± 145.6 cm2). There was only one case of unsuccessful flap transfer, and four cases had a few complications. The characteristics of the complication group included a large flap size (303.1 ± 170.9 vs. 214.9 ± 136.6 cm2, P = .211), few perforator numbers without pedicle manipulation, lack of intraoperative indocyanine green administration (75% vs. 25%, P = .607), and the use of superficial temporal vessels as recipient vessels. Scalp reconstruction using large ALT free flaps with the aid of imaging modalities facilitates the optimization of surgical techniques, such as pedicle manipulation, perforator numbers, and vein considerations, thereby contributing to successful reconstruction.

36-year Follow-up on Scalp Reconstruction Using Free Latissimus Dorsi Muscle Flap, Skin Grafting, and Scalp Expansion.

Immediate coverage of a large area of exposed skull is the first step in reconstructing a major scalp loss. In the 1970s, the free omental flap was used for scalp reconstruction, replacing removal of the external table and skin grafting only. Introduction of flaps and expanders has revolutionized reconstruction of major scalp losses. A free muscle flap is used to cover the exposed skull. Skin graft covers the muscle flap, and next, the expanded scalp is used to restore the scalp to its original shape. In certain cases, a hair transplant could help create a more natural hairline. In this case, in 1987, a free latissimus dorsi muscle flap and skin grafting were used in a 27-year-old man with major scalp loss. The left latissimus dorsi muscle was harvested with its vascular pedicle intact. Left superficial temporal vessels were used as recipients. After complete healing of the free flap, scalp and forehead skin were expanded and used to restore the scalp to its preinjury shape. Coverage of the exposed parietal skull with free latissimus dorsi muscle flap and skin graft was successful. Then, scalp tissue surrounding the defect and forehead skin were expanded and used to restore the scalp to its original shape. This 36-year follow-up in a patient who had major scalp reconstruction using free latissimus dorsi muscle and skin grafting followed by scalp and forehead expansion shows that this method provides an excellent and reliable long-term coverage for such an injury.

An Innovative Preauricular Free Flap Pedicled with Retrograde Vascular (PFFPRV) for Pediatric Nasal Reconstruction.

Nasal reconstruction in pediatric patient is very challenging and it requires consideration of later nasal development. Herein, we introduce an innovative preauricular free flap pedicled with retrograde vascular (PFFPRV) for pediatric nasal reconstruction. In this PFFPRV technique, the retrograde superficial temporal vessels were used as the flap pedicle. The lateral alar artery and angular vein were used as vessels of the nasal recipient zone. The flap vessels were anastomosed directly to the recipient area vessels without additional vessel transplantation. Eight pediatric patients with nasal defects underwent this operation. All patients were followed up for more than 2 years. Patients' medical history data were retrospectively analyzed. Preoperative and postoperative facial photos were compared and analyzed. The satisfaction of patient's parents with the aesthetic results was assessed. All patients were successfully operated without intraoperative complications. None of the procedures required additional blood vessel grafts. One patient developed a vascular crisis the next day after the surgery and underwent vascular exploration operation. The free flaps of all patients survived without wound infection or necrosis. The color difference of flap gradually became unobvious. The transplanted flap did not show obvious contracture or retraction, and the nose was symmetrical and developed well. The parents of all patients were satisfied with the surgical results. We think this PFFPRV technique can be a reasonable alternative strategy for reconstruction of pediatric nasal defect, with no adverse effect on nasal development and no need of vascular transplantation. Level IV, therapeutic study.

Anatomical Study of the Application of a Galeo-Pericranial Flap in Oral Cavity Defects Reconstruction.

Oral cavity defects occur after resection of lesions limited to the mucosa, alveolar gum, or minimally affecting the bone. Aiming at esthetical and functional improvements of intraoral reconstruction, the possibility of harvesting a new galeo-pericranial free flap was explored. The objective of this study was to assess the technical feasibility of flap harvesting through anatomical dissections and surgical procedure simulations. Ten head and neck specimens were dissected to simulate the surgical technique and evaluate the vascular calibers of temporal and cervical vessels. The procedure was therefore reproduced on a revascularized and ventilated donor cadaver. Anatomical dissections demonstrated that the mean cervical vascular calibers are compatible with superficial temporal ones, proving to be adequate for anastomosis. Perforating branches of the superficial temporal vascularization nourishing the pericranium were identified in all specimens. In conclusion, blood flow presence was recorded after anastomosing superficial temporal and facial vessels in the revascularized donor cadaver, demonstrating both this procedure's technical feasibility and the potential revascularization of the flap and therefore encouraging its potential in vivo application.

Primary Free Flaps for Coverage and Reconstruction in Acute Facial Trauma.

Background Acute facial trauma in motor vehicle accident defects may be associated with skeletal, neuromuscular, or mucosal losses. Simultaneous repair of the critical structures in these defects mandates the use of flap cover; paucity of local tissues necessitates the use of free skin flaps. Materials and Methods Six free flap reconstructions for acute facial trauma defects over a 10-year period were reviewed. The defect location, associated injuries, flap choice, additional reconstructive procedures, and flap outcomes were analyzed. Results There were four males and two females with ages between 18 and 63 years. Four defects were located in the lateral face and scalp, and two in the lower central face. Defect size ranged between 96 and 346 cm 2 . There were fractures in three, facial nerve injuries in two, and loss of facial muscles in one. Five free flaps were anterolateral thigh flap; simple and composite, one was a radial artery forearm flap. Recipient pedicles were the superficial temporal vessels in two and facial vessels in four cases. There were no re-explorations but one flap necrosed on 7th postoperative day on account of invasive aspergillosis. Discussion Use of free flaps for ballistic wounds is common. In uncommon nonballistic traumatic facial defects, the location, nature of the defect, and type of associated injuries and need for simultaneous reconstructions may dictate the use of free flaps and permit a one stage debridement, flap coverage, and a simultaneous reconstruction of lost functional units. Conclusion Free flap coverage in high velocity acute facial trauma defects offers a better possibility for primary reconstruction of associated facial injuries and helps in achieving better functional outcomes.

Combined Face and Whole Eye Transplantation: Cadaveric Rehearsals and Feasibility Assessment.

In properly selected patients, combined face and whole eye transplantation (FWET) may offer a more optimal aesthetic and potentially functional outcome while avoiding the complications and stigma of enucleation and prosthetics. This study presents the most comprehensive cadaveric assessment for FWET to date, including rehearsal allograft procurement on a brain-dead donor. Over a 2-year period, 15 rehearsal dissections were performed on 21 cadavers and one brain-dead donor. After identification of a potential recipient, rehearsals assessed clinical feasibility and enabled operative planning, technical practice, refinement of personalized equipment, and improved communication among team members. Operative techniques are described. Facial allograft procurement closely followed previously described face transplant techniques. Ophthalmic to superficial temporal (O-ST) vessel anastomosis for globe survival was assessed. Craniectomy allowed for maximal optic nerve and ophthalmic vessel pedicle length. Appropriate pedicle length and vessel caliber for O-ST anastomosis was seen. Research procurement demonstrated collateral blood flow to the orbit and surrounding structures from the external carotid system as well as confirmed the feasibility of timely O-ST anastomosis. Personalized cutting guides enabled highly accurate bony inset. This study formalizes an approach to FWET, which is feasible for clinical translation in judiciously selected patients. O-ST anastomosis seems to minimize retinal ischemia time and allow perfusion of the combined allograft on a single external carotid pedicle. Although restoration of vision likely remains out of reach, globe survival is possible.

Application of indocyanine green angiography in repair of facial soft tissue defect using superficial temporal artery based forehead flap

To explore the feasibility of using indocyanine green angiography in mapping the superficial temporal vessels and assisting design and harvesting of the superficial temporal artery based forehead flap. A clinical data of 14 patients with facial soft tissue defects repaired with superficial temporal artery based forehead flaps between October 2015 and November 2022 was retrospectively analyzed. There were 9 males and 5 females with a median age of 9.5 years (range, 3-38 years). The forehead flaps were used to reconstruct facial soft tissue defects following excision of facial scar (8 cases) or congenital melanocyte nevus (6 cases). The size of defects ranged from 3 cm×2 cm to 24 cm×9 cm. Before operation, the indocyanine green angiography was used to map the superficial temporal artery and vein, and to analyze the relationship of the arteries and veins. The forehead flaps with unilateral superficial temporal fascia as the pedicle was transferred to repair the small facial defect in 2 cases. The facial pedicle contained the frontal branch of the superficial temporal artery and 2 cm of the superficial temporal fascia around the vessel, and the tiny accompanying vein of the frontal branch of the superficial temporal artery was used as the outflow of the flap. The forehead flaps with the skin pedicle including bilateral or unilateral superficial temporal fascia and the overlying skin was pre-expanded and transferred to repair the large facial defect in 12 cases. The skin pedicle contained the frontal branch of superficial temporal artery and one of main branches of superficial temporal vein. Among the 12 cases, the frontal branch of superficial temporal vein was used as the outflow in 4 cases, and the parietal branch was used as the outflow in 8 cases. The size of the flaps ranged from 3 cm×2 cm to 30 cm×13 cm. The skin pedicles were divided at 3 weeks after the flap transfer. Indocyanine green angiography could clearly showed the course and branching of the superficial temporal artery and vein. Individual differences existed in the location where the frontal branch of the superficial temporal artery entered the forehead. The superficial temporal vein had great variability and did not follow the artery. One patient had expander-related complication, which resulted in 3-cm flap necrosis. The necrotic tissue was debrided and repaired with skin grafting. The other flaps totally survived and the incisions healed by first intention. All patients were followed up 2-24 months, with a median of 11.5 months. The color, texture, and thickness of the flaps matched well with those of recipient sites. Hypertrophic scar was not observed in recipient or donor site. All patients were satisfied with the reconstructive outcomes. Indocyanine green angiography can clearly visualize the course and the branches of the superficial temporal arteries and veins, which can help surgeons understand the position, distribution, and concomitant relationship of the superficial temporal vessels, and make a rational surgical plan of the forehead flap.

Supraorbital Rim and Roof Reconstruction with Vascularized Fascia Lata and Autogenous Rib Graft.

Describe a novel technique for reconstruction of complex defects involving supraorbital rim and orbital roof. Retrospective chart review and description of surgical technique. Four patients underwent tumor resection with neurosurgery (2 intraosseous hemangioma, 1 meningioma, and 1 ossifying fibroma), with mean tumor size of 42.6 cubic centimeters on preoperative imaging. All defects involved supraorbital rim and orbital roof. Patients were reconstructed with autogenous osseous rib graft for structure and contour and anterolateral thigh fascia lata (ALTFL) free flap to provide robust vascularity to rib bone and as a barrier between skull base dura and the orbit and/or sinonasal cavities. Two patients underwent resection and reconstruction using minimal access incisions, and two underwent major cranial and skull base resections. All flaps are vascularized via superficial temporal vessels. On postoperative follow-up (mean 33.5 months, range 8-48), all patients report no vision change or diplopia, with excellent contour symmetry to contralateral orbit. Follow-up imaging (mean 29.5 months, range 3-48) demonstrated maintained orbital volume and retention of rib bone graft compared to immediate postoperative imaging. There were no complications related to graft use. Minor complications include 1 patient with cerebrospinal fluid leak managed with lumbar drain placement and 1 patient with mild enophthalmos at 7-month follow-up. We describe a series of patients who underwent a novel technique for reconstruction of complex defects involving supraorbital rim and orbital roof with autogenous osseous rib and vascularized ALTFL-free flap with excellent functional and cosmetic outcomes. This can be accomplished using minimal access techniques to minimize patient morbidity. 4 Laryngoscope, 134:654-658, 2024.

Eril's Branch-Based Perforator Plus Chondro-Cutaneous Flap for Reconstruction of Upper Third Helico-Scaphal Defects: A Clinical and Cadaver Study.

Reconstruction of upper third helico-scaphal defects (HSDs) exacts the expertise of the reconstructive surgeon. These three-dimensional defects deviate from normal facial form and cause a significant impact on the psyche of the patients. The origin, course, and dimensions of the perforators of the Eril's branch arising from superficial temporal vessels (EBSTV) were delineated by dissection and injection study. They were examined in twenty-four adult specimens. A prospective cohort study was conducted from March 2017 to March 2020, including six patients whose upper third HSDs were reconstructed with perforator plus chondro cutaneous flap based on EBSTV. After the debridement of the defect, the perforator plus chondro cutaneous flap was harvested from retro auricular sulcus skin with attached cartilages from triangular fossa and interhelical groove. The donor site was closed primarily, and the flap was rotated onto the defect. Superficial temporal vessels give a constant Eril's branch at the level of the root of the helix (otobasion superioris), which in turn divides into two perforators -superficial (lateral) and deep (medial) perforators. All six patients with post-traumatic upper third HSDs (4 males and 2 females) after reconstruction were followed for an average period of 15months. The average age was 36.5yrs. On average, two cartilages of maximum dimensions 3 × 2.5mm were included in the perforator plus chondro cutaneous flap based on the medial-deep perforator of the EBSTV. In all six cases, the flaps survived without any complications. The average final computed institutional objective and subjective score was 15.67 (excellent results) (chi-square test, the p value was (p = 0.035) significant). The perforator plus chondro-cutaneous flap based on deep medial perforator of EBSTV may be a useful addendum in the armamentarium of plastic surgery. This novel reconstruction technique of upper helical defects provides good shape, size, and aesthesis of the upper external ear.

Recipient vessels for free flaps in advanced facial oncologic defects

ObjectivesTo prospectively compare the results of microvascular flap reconstruction of midface and scalp advanced oncologic defects using superficial temporal versus cervical as recipient vessels. MethodsThis is a parallel group clinical trial with 1:1 allocation ratio of patients who underwent midface and scalp oncologic reconstruction with free tissue flap from April 2018 to April 2022 in a tertiary oncologic center. Two groups were analyzed: those in whom superficial temporal vessels were used as the recipient vessels (Group A) and those in whom cervical vessels were used as the recipient vessels (Group B). Patient gender and age, cause and localization of the defect, flap choice for reconstruction, recipient vessels, intraoperative outcome, postoperative course, and complications were recorded and analyzed. A Fisher’s exact test was used to compare outcomes between the 2 groups. ResultsOn the basis of the different recipient vessels, 32 patients were randomized into 2 groups, and of these 27 patients completed the study: Group A with superficial temporal recipient vessels (n = 12) and Group B with cervical recipient vessels (n = 15). There were 18 male and 09 female patients with an average age of 53.92 ± 17.49 years. The overall flap survival rate was 88.89%. The overall complication rate for vascular anastomosis was 14.81%. The total flap loss rate in patients with superficial temporal recipient vessels was higher than the complication rate in those with cervical recipient vessels but with no statistical significance (16.67% vs. 6.66%, p = 0.569). Minor complications occurred in 05 patients without statistical significance between the groups (p = 0.342). ConclusionIn the group with superficial temporal recipient vessels, the postoperative rate of free flap complications was similar than the cervical recipient vessel group. Therefore the use of superficial temporal recipient vessels for midface and scalp oncologic reconstruction could be a reliable option.

The Transfer of Expanded Forehead Superthin Flap Without Frontalis and Less Hair Follicles Pedicled by Superficial Temporal Vessels.

The expanded forehead flap pedicled with superficial temporal vessel(s) is a common method to treat facial scar deformity. However, local bulkiness and hair retention have limited the use of this flap. Five cadavers were used for anatomy to confirm the forehead "safety zone." A retrospective study was performed on 15 patients with facial scar deformity who were undergoing the expanded forehead superthin flap (without the expanded capsule, frontalis muscle, and with less hair follicles) pedicled with superficial temporal vessel(s) to transfer and repair the deformity. Through cadaver anatomy, the range where the subdermal vascular network laid superficial to the hair follicle level was named the "safety zone," whose average distance between the bilateral penetrating points was 10.2 cm (8.7-11.6 cm). Fifteen patients with facial scar deformity were treated with the superthin flap technique. The trimming size of the safety zone flap was (6-10) × (12-20) cm. The median time of thinning the safety zone was 35 minutes (range, 25-40 minutes). All flaps healed well. The median residual ratio of the hair follicle was 39.8% (29.9%-50.5%). All patients were satisfied with the contour of the flap. We firstly proposed a concept of forehead safety zone and used the superthin flap without the frontalis muscle and less hair follicles to treat facial scar deformity, and obtained an improved therapeutic effect. We think this is an appealing technique that can manifest facial concave and convex in the fine part, improve compliance of the flap, and reduce the times of laser hair removal.

High-Frequency Ultrasound-Guided Temporal Fat Transplantation: A Safe and Visualized Approach.

Autologous fat injection is one of the most popular methods for the treatment of temporal depression; however, accurate puncture into the target layer without vascular compromise is hard to achieve. With the aid of high-frequency ultrasonography, the authors performed autologous fat transplantation after visualization in five cases, with satisfactory results. The authors observed the course of superficial temporal vessels, the orbitozygomatic artery, and sentinel veins preoperatively, and used high-frequency ultrasonography to guide lipotransfer into the desired layer intraoperatively, to avoid intravascular injection. With the aid of high-frequency ultrasonography, the authors can easily prevent vascular complications and personalize surgical procedures, as anatomical variations of vasculature can also be detected by means of this method.

Cervical versus superficial temporal recipient vessels in midface and scalp free tissue flap for advanced oncologic reconstruction: Prospective and randomized study

Cervical versus superficial temporal recipient vessels in midface and scalp free tissue flap for advanced oncologic reconstruction: Prospective and randomized study

Hair-Bearing Expanded Scalp Flap for Total Beard Reconstruction in Patients With Chin and Submental Postburn Scars.

Loss of beard in adult male caused by severe burn may cause cosmetic and psychological problems for these patients. Reconstruction of the beard with hair-bearing skin flaps in similar color and texture of the surrounding tissues remains a challenge. Eight male patients suffered from submental postburn scar and beard loss were treated by using the hair-bearing expanded scalp flap. A 1000mL nephroid tissue expander was first implanted under the frontal and mid scalp. After a 3 to 4-month tissue expansion, the expanded hair-bearing scalp flap based on bilateral superficial temporal vessels were raised and transferred for beard reconstruction, and the cutaneous pedicles were curled into tubes. Delay and division of the pedicles were performed 3 to 4 weeks after flap transfer. Eight male patients with postburn scar and beard loss were successfully treated with no major complication. One patient suffered from edge necrosis at distal end of the flap and healed after daily dressing change. Chin and submental areas were repaired by expanded scalp flap and total beard was reconstructed at the same time. All donor sites were closed directly without skin grafting. The modified expanded bipedicled scalp flap provides an easy and reliable way for total beard reconstruction and large-scale submental scars repairment.

A Reversal Forehead Free Flap Transplantation Without Interrupted Perfusion for Esthetic Repairing the Mentocervical Scar Deformity.

The forehead flap is widely used to repair facial defects. The traditional method would transfer some hair to the recipient area, where the reconstructed beard lies in a misplaced position. The authors designed a reversal forehead free flap method that transposed the flap to 180 degrees, rebuilding the reconstructed beard in the normal position. In addition, the authors used the frontal branches of the superficial temporal vessels on both sides to anastomose with the contralateral parietal branches to lengthen the pedicle and avoid ischemia-reperfusion injury. Level of Evidence : 4.

The Use of Infrared Thermography in Determining Timing for Early Pedicle Division of the Preexpanded Bipedicled Visor Flap after Ischemic Preconditioning.

Background The preexpanded bipedicled visor flap, supported by the bilateral superficial temporal vessels, stands as an ideal choice for upper and lower lip reconstruction in males. However, the bilateral tissue bridges after flap transfer caused patients significant cosmetic deformity and psychological burden. Early division of bilateral pedicles reduced the length of hospitalization and expenses. In this study, infrared thermography (IRT) was used to guide the early pedicle division after ischemic preconditioning. Methods This study retrospectively analyzed patients who underwent preexpanded bipedicled visor flap surgery from April 2018 to October 2021. Pedicle division was scheduled at two weeks postflap transfer. Ischemic preconditioning was initiated 3-5 days in advance by repeatedly clamping both pedicles. The temperature alteration of the flap and the temperature difference compared to the normal adjacent tissue were evaluated by IRT. The division surgery was not scheduled until the perfusion assessment indicated adequate. This comprised of subjective examination and indocyanine green angiography. The threshold of temperature difference to determine the pedicle division was analyzed based on the temperature changes between the clamps. Results A total of 8 male patients successfully conducted the pedicle division without any complications. The delay period after ischemic preconditioning ranged from 14 to 19 days (average 16 days). Through ischemic preconditioning training, the average temperature of the flap gradually increased from 31.85 ± 0.36°C to 33.89 ± 0.50°C, and the temperature difference with the normal surrounding tissues decreased from 2.89 ± 0.30°C to 1.15 ± 0.46°C (95% confidence interval (1.5, 0.8)). The temperature difference stayed unchanged after pedicle division. Conclusion Ischemic preconditioning shortens the perioperative period to pedicle division. Monitoring the temperature change reflects the revascularization between the flap and the recipient site, thus guiding the pedicle division. The temperature difference less than 1.5°C after clamping both pedicles can be set as the safe threshold for pedicle division.