Enhancing Surgical Approach: Breakthrough Markerless Surface Registration With Augmented Reality for Zygomatic Complex Fracture Surgeries.

BACKGROUND: Innovative technologies with surgical navigation have been used for enhancing surgical accuracies for zygomaticomaxillary complex (ZMC) fractures and offers advantages in precision, accuracy, effectiveness, predictability, and symmetry improvement. Moreover, augmented reality (AR) navigation technology combines virtual reality, 3-dimensional (3D) reconstruction, and real-time interaction, making it ideal for bone tissue operations. Our study explored the usefulness and clinical efficacy of AR technology in intraoperative guidance for reducing ZMC fractures. METHODS: We retrospectively studied 35 patients with zygomatic complex fractures, comparing outcomes of AR-guided and conventional methods. Furthermore, the AR system provided real-time visualization and guidance. The evaluation included reduction accuracy using root mean square (RMS) value and symmetry analysis using a mirror image of 3D models. Results demonstrated the feasibility and effectiveness of the AR-guided method in improving outcomes and patient satisfaction. RESULTS: In 35 patients (25 males, 10 females), AR-guided (n = 19) and conventional (n = 16) approaches were compared. Age, sex, and fracture type exhibited no significant differences between groups. No complications occurred, and postoperative RMS error significantly decreased ( P < 0.001). The AR group had a lower postoperative RMS error ( P = 0.034). CONCLUSIONS: Augmented reality-guided surgery improved accuracy and outcomes in zygomatic complex fractures. Real-time visualization enhanced precision during reduction and fixation. This innovative approach promises enhanced surgical accuracy and patient outcomes in craniofacial surgery.

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

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Effect of Therapeutic Radiation on Polycaprolactone/Hydroxyapatite Biomaterials in a Calvarial Model.

Bone defects caused by cancer resection often require postoperative radiotherapy. Although various synthetic polymers have been introduced as graft materials, their biological behavior after radiation exposure remains unclear. Here, we investigated how polycaprolactone/hydroxyapatite (PCL/HA) implants respond to therapeutic radiation exposure (in terms of volume and bone regeneration). Four 8 mm diameter calvaria defects were surgically created on the parietal bone of 6 rabbits. PCL/HA implants made of porous, solid, and hybrid polymers were grafted by random placement in each defect. The fourth defect was left untreated. Four weeks after surgery, radiation exposure was conducted weekly for 6 weeks (total: 48 Gy). Micro-computed tomography and histologic analysis were performed at 3 and 6 months, and 6 months postradiation, respectively. The total augmented volumes of all implants showed no significant differences between 3- and 6-months postradiation computed tomography images. In histologic analysis, new bone areas were 0.45±0.11 mm2, 2.02±0.34 mm2, and 3.60±0.77 mm2 in solid, hybrid, and porous polymer grafts, respectively. Bone regeneration was limited to the periphery of the defect in the hybrid and porous polymer grafts, whereas new bone formed inside the porous implant. The total augmented volume of the defect was maintained without significant absorption even after radiation exposure. The PCL/HA implant maintained its structure despite radiation exposure. The porous PCL/HA implant demonstrated excellent bone regeneration, followed by the hybrid and solid implants. The PCL/HA implant is a promising candidate for bone defect reconstruction.

Successful replantation of an avulsed frontal scalp through microvascular anastomoses of only one artery and one vein: a case report.

Scalp avulsion is a devastating injury. The best possible procedure is replantation. Several successful scalp replantations with anastomoses of several vessels in large defects have been reported. In this report, we present a case of replantation of a large scalp avulsion using revascularizing with only one artery and vein. Despite the initial signs of flap congestion, we could predict the survival of the replanted scalp and terminate the procedure after detecting good perfusion and washout with indocyanine green fluorescence imaging. The procedure was successful following the patient's recovery of sensory and sweating functions without complications such as flap necrosis or infection. Several important factors for successful scalp replantation with positive esthetic and functional outcomes were considered.

Generation of sarconoids from angiosarcoma patients as a systematic-based rational approach to treatment.

Angiosarcoma is a rare subtype of malignant neoplasm originating from vascular or lymphatic endothelial cells; its low incidence has posed significant challenges for comprehensive investigations into its pathogenic mechanisms and the development of innovative treatment modalities through in vitro and in vivo models. Recent endeavors spearheaded by patient-partnered research initiatives have aimed to elucidate the intricacies of angiosarcomas by leveraging biological omics approaches, with the overarching objective of enhancing prognostic indicators and therapeutic options for this uncommon pathology. To bridge the gap between preclinical research and translational applications, we engineered angiosarcoma-derived organoids from surgically resected primary tumors, hereafter referred to as "sarconoids," as a proof-of-concept model. A novel protocol for the establishment of these sarconoids has been developed and validated. To ensure that the sarconoids faithfully recapitulate the heterogeneity and complexities of the patients' original tumors, including transcriptomic signatures, cell-type specificity, and morphological traits, exhaustive histological and transcriptomic analyses were conducted. Subsequently, we expanded the scope of our study to include an evaluation of a sarconoid-based drug screening platform; for this purpose, a drug library (AOD IX), supplied by the National Cancer Institute's Developmental Therapeutics Program, was screened using 96-well plates. Our findings suggest that sarconoids can be reliably generated from angiosarcoma patient-derived tissues and can serve as accurate models for evaluating therapeutic responses, thereby holding far-reaching implications for translational research and clinical applications aimed at advancing our understanding and treatment of angiosarcoma.

Application of augmented reality using automatic markerless registration for facial plastic and reconstructive surgery.

This study aimed to present a novel markerless augmented reality (AR) system using automatic registration based on machine-learning algorithms that visualize the facial region and provide an intraoperative guide for facial plastic and reconstructive surgeries. This study prospectively enrolled 20 patients scheduled for facial plastic and reconstructive surgeries. The AR system visualizes computed tomographic data in three-dimensional (3D) space by aligning with the point clouds captured by a 3D camera. Point cloud registration consists of two stages: the preliminary registration gives an initial estimate of the transformation using landmark detection, followed by the precise registration using Iterative Closest Point algorithms. Computed Tomography (CT) data can be visualized as two-dimensional slice images or 3D images by the AR system. The AR registration error was defined as the cloud-to-cloud distance between the surface data obtained from the CT and 3D camera. The error was calculated in each facial territory, including the upper, middle, and lower face, while patients were awake and orally intubated, respectively. The mean registration errors were 1.490 ± 0.384 mm and 1.948 ± 0.638 mm while patients were awake and orally intubated, respectively. There was a significant difference in the errors in the lower face between patients while they were awake (1.502 ± 0.480 mm) and orally intubated (2.325 ± 0.971 mm) when stratified by facial territories (p = 0.006). The markerless AR can accurately visualize the facial region with a mean overall registration error of 1-2 mm, with a slight increase in the lower face due to errors arising from tube intubation.