Automatic detection of midfacial fractures in facial bone CT images using deep learning-based object detection models.

BACKGROUND: Midfacial fractures are among the most frequent facial fractures. Surgery is recommended within 2 weeks of injury, but this time frame is often extended because the fracture is missed on diagnostic imaging in the busy emergency medicine setting. Using deep learning technology, which has progressed markedly in various fields, we attempted to develop a system for the automatic detection of midfacial fractures. The purpose of this study was to use this system to diagnose fractures accurately and rapidly, with the intention of benefiting both patients and emergency room physicians. METHODS: One hundred computed tomography images that included midfacial fractures (e.g., maxillary, zygomatic, nasal, and orbital fractures) were prepared. In each axial image, the fracture area was surrounded by a rectangular region to create the annotation data. Eighty images were randomly classified as the training dataset (3736 slices) and 20 as the validation dataset (883 slices). Training and validation were performed using Single Shot MultiBox Detector (SSD) and version 8 of You Only Look Once (YOLOv8), which are object detection algorithms. RESULTS: The performance indicators for SSD and YOLOv8 were respectively: precision, 0.872 and 0.871; recall, 0.823 and 0.775; F1 score, 0.846 and 0.82; average precision, 0.899 and 0.769. CONCLUSIONS: The use of deep learning techniques allowed the automatic detection of midfacial fractures with good accuracy and high speed. The system developed in this study is promising for automated detection of midfacial fractures and may provide a quick and accurate solution for emergency medical care and other settings.

Automatic orbital segmentation using deep learning-based 2D U-net and accuracy evaluation: A retrospective study.

The purpose of this study was to verify whether the accuracy of automatic segmentation (AS) of computed tomography (CT) images of fractured orbits using deep learning (DL) is sufficient for clinical application. In the surgery of orbital fractures, many methods have been reported to create a 3D anatomical model for use as a reference. However, because the orbit bone is thin and complex, creating a segmentation model for 3D printing is complicated and time-consuming. Here, the training of DL was performed using U-Net as the DL model, and the AS output was validated with Dice coefficients and average symmetry surface distance (ASSD). In addition, the AS output was 3D printed and evaluated for accuracy by four surgeons, each with over 15 years of clinical experience. One hundred twenty-five CT images were prepared, and manual orbital segmentation was performed in all cases. Ten orbital fracture cases were randomly selected as validation data, and the remaining 115 were set as training data. AS was successful in all cases, with good accuracy: Dice, 0.860 ± 0.033 (mean ± SD); ASSD, 0.713 ± 0.212 mm. In evaluating AS accuracy, the expert surgeons generally considered that it could be used for surgical support without further modification. The orbital AS algorithm developed using DL in this study is extremely accurate and can create 3D models rapidly at low cost, potentially enabling safer and more accurate surgeries.

Prolonged Survival in a Patient With Extensive-Stage Small Cell Lung Cancer in Spite of Discontinued Immunotherapy With Atezolizumab.

A 64-year-old man was referred from a local clinic with a chief complaint of cough. Computed tomography (CT) revealed a mass comprising a tumor in the right lower lobe and enlarged mediastinal lymph nodes, and a whole-body workup with positron emission tomography-CT showed bilateral lymph node enlargement and cancerous pericarditis. Biopsy with bronchoscopy of the right lower lobe tumor and mediastinal lymph node confirmed the histological findings of small cell lung carcinoma. The clinical diagnosis of extensive-stage small cell lung cancer (ES-SCLC) was confirmed, and first-line treatment with carboplatin, etoposide, and atezolizumab was initiated, followed by tri-weekly atezolizumab thrice. The patient experienced worsening pleural effusion treated with thoracentesis, pleural drainage, and pleurodesis. He also experienced several recurrences, which were managed with second and third-line chemotherapy with nogitecan and amrubicin. He has been receiving third-line therapy for over 30 months since his initial visit and remains stable as of today. The patient experienced an exceptional treatment outcome considering that the prognosis of ES-SCLC remains poor, with a median survival of approximately 10 months with conventional chemotherapies using cytotoxic agents. The use of immune checkpoint inhibitors (ICI) for ES-SCLC as first-line treatment may demonstrate a persistent antitumor effect, and result in improved survival following discontinuation. In conclusion, therapy including ICI for patients with ES-SCLC is a treatment option that shows possibilities in improving survival even after discontinuation.

Multimerization of small G-protein H-Ras induced by chemical modification at hyper variable region with caged compound.

The lipid-anchored small G protein Ras is a central regulator of cellular signal transduction processes, thereby functioning as a molecular switch. Ras forms a nanocluster on the plasma membrane by modifying lipids in the hypervariable region (HVR) at the C-terminus to exhibit physiological functions. In this study, we demonstrated that chemical modification of cysteine residues in HVR with caged compounds (instead of lipidation) induces multimerization of H-Ras. The sulfhydryl-reactive caged compound, 2-nitrobenzyl bromide, was stoichiometrically incorporated into the cysteine residue of HVR and induced the formation of the Ras multimer. Light irradiation induced the elimination of the 2-nitrobenzyl group, resulting in the conversion of the multimer to a monomer. Size-exclusion chromatography coupled with high-performance liquid chromatography and small-angle x-ray scattering analysis revealed that H-Ras forms a pentamer. Electron microscopic observation of the multimer showed a circular ring shape, which is consistent with the structure estimated from x-ray scattering. The shape of the multimer may reflect the physiological state of Ras. It was suggested that the multimerization and monomerization of H-Ras were controlled by modification with a caged compound in HVR under light irradiation.

Extension toward the Trapezius in a Transversely Oriented Latissimus Dorsi Flap for Breast Reconstruction.

A transverse paddle latissimus dorsi (LD) flap has the advantage that if the skin paddle is placed in the transverse bra line, the donor site scar is well hidden by underwear. With this transfer, medial back tissues are usually moved to the medial area of the reconstructed breast following 180 degree rotation. Because these tissues are thinner than the lateral thoracic area, the medial part of the reconstructed breast sometimes becomes flatter than expected. METHODS: To add bulk in the medial lower quadrant for giving an impression of an outward-expanding breast, we modified the LD flap by adding a part of the trapezius muscle. Seven patients underwent mastectomy and simultaneously received a modified LD flap. To hide the donor site scar beneath underwear, the skin paddle needed to be oriented transversely. The additional harvested tissues were tested for vascularity by fluorescence following intravascular injections of indocyanine green. If this was negative, the tissue was not used for breast reconstruction. Postoperatively, another surgeon judged whether this modification had contributed favorably to the reconstructed medial lower quadrant. RESULTS: Indocyanine green testing was positive in six cases. The shape of the lower medial quadrant was judged as good in five of the seven cases. Complications included an animation deformity of the LD muscle, donor site seroma, and donor site wound dehiscence. CONCLUSION: This transversely oriented LD flap with extension to the trapezius muscle placed at the bra-line is one option to add bulk to the medial lower quadrant of the reconstructed breast when an additional scar is not desired for cosmetic reasons.

The influence of venous system patterns on DIEP flap viability for breast reconstruction.

A deep inferior epigastric artery perforator (DIEP) flap has unique variations in the anatomy of the vascular supply, and this idea has been adapted to the venous system. Venous system patterns, including connections between the superficial and deep inferior epigastric vein (SDC) or connections of the superficial inferior epigastric vein across the midline-crossing linking veins (MCLV), have gradually become recognized as a cause of fat necrosis and induration due to venous congestion. Therefore, it is important to select patients who are appropriate for transplantation by evaluating blood flow in the flap based on these patterns. The subjects were 52 consecutive patients who underwent DIEP flap breast reconstruction. Relationships of fat necrosis and induration of a transplanted flap and venous system patterns (presence of SDC on the contralateral side: cSDC or MCLV, direction and diameter of perforator vein) in the flap were investigated. Logistic regression and univariate and multivariate analyses were used to identify predictors of fat necrosis and induration of the flap. Fat necrosis and induration were detected in 17.4 and 34.8% of cases, respectively. These incidences were significantly linked to the absence of cSDC and MCLV patterns in the flap. Patients without a cSDC or MCLV pattern had harder fat tissue in Zone II, especially in the distal portion. These results suggest that the absence of a cSDC or MCLV pattern causes complications such as fat necrosis and induration in a transplanted flap. If neither pattern is detected before surgery, improvement of venous drainage is recommended.

Innovative CAD/CAM Guide for Mandibular Reconstruction with Metallic Condylar Head and Free Fibular Flap.

In reconstructions of mandibles and condyles, free fibular flaps and metallic condylar heads (CH) are often used after resection. However, in conventional reconstructions, it is difficult to fix the metallic CH on the same preoperative position because the position is determined visually. Therefore, we have made an original computer-aided design and manufacture (CAD/CAM) guide for mandibular condyle reconstruction, combining a metallic CH with a free fibular flap. A 71-year-old woman with gingival carcinoma underwent hemimandibulectomy. We reconstructed the mandible and condyle with a metallic CH and a free fibular flap. We placed a mark on the CAD/CAM guide showing the correct position for fixing the CH to the fibular blocks. We also designed a surface for attaching to the healthy edge of the mandible. The fibular blocks and metallic CH were fixed as 1 unit before separating the flap from the leg and replacing the diseased tissue. Reconstruction was completed by fixing the attachment surface to the healthy side of the mandible. The guide marks solved the difficulty of conventional reconstruction; during surgery, we fixed the metallic CH to the same position as the original bone using these marks. The postoperative deviation of the condyle from the virtual plan was 4.3 mm, whereas the reported deviation of such prostheses was 3.8 mm (range 1.3-6.7); so our guide was acceptably accurate. Furthermore, it appears that the CAD/CAM guide is more useful for reconstruction after hemimandibulectomy including the condyle than after segmental resection without including condyle.

Reconstruction of a Pharyngeal Cutaneous Fistula Using a Bi-Paddled Pectoralis Major Flap for a Patient with a Possibility of Future Postoperative Radiotherapy.

BACKGROUND Pharyngocutaneous fistulas are often difficult to treat because pharyngeal contents tend to leak into the cervical layer causing wound infections or abscesses. If reconstruction with free flaps is difficult, pedicled pectoralis major flaps are an option. CASE REPORT A 51-year-old male patient who had undergone radiation and chemotherapy for laryngeal cancer was scheduled for total laryngectomy with combined skin resection for local tumor recurrence. Reconstruction with a left deltopectoral (DP) flap was performed. However, a pharyngocutaneous fistula constructed due to cervical soft-tissue infection required reconstruction using a right bi-paddled pectoralis major muscle. The anterior pharyngeal wall was reconstructed with the medial skin island, and the lateral skin island was folded back to reconstruct the soft tissues. Since this was the patient's third recurrence, the possibility of subsequent local recurrences, and hence of the need for radiation therapy, were high. In such cases, the pedicle of the pectoralis major muscle flap is normally closed using a DP flap. However, in the present case, the DP flap had already been used on both sides. We therefore utilized a right bi-paddled pectoralis major flap for cervical reconstruction. CONCLUSIONS We successfully reconstructed the cervical skin and soft tissue thickly, and primarily-closed the donor site, by creating a second skin island from surplus areas of the existing skin island. This method is particularly useful for the reconstruction of cervical skin and soft tissues due to the possible need for future radiation therapy, when the use of free flaps and DP flap is unfeasible.

Does an In-House Computer-Aided Design/Computer-Aided Manufacturing Approach Contribute to Accuracy and Time Shortening in Mandibular Reconstruction?

Mandibular reconstruction using computer-aided design and computer-assisted manufacturing (CAD/CAM) techniques has received recent attention. This technique has theoretical advantages, although this approach can be commercially used in the limited area of the world.The aim is to describe our experience using in-house CAD/CAM guides and the situations in which CAD/CAM may present benefit in the region where commercial guides are unavailable.The authors developed our In-house CAD/CAM approach for mandibular reconstructions with a free fibular flap. Patients were divided into 2 group; CAD/CAM and conventional groups. In the CAD/CAM group, reconstructions were planned virtually using CAD/CAM; these CAD/CAM guides were used in the surgery. In the conventional group, free-hand cutting and fitting of the fibular segments were performed as reconstructions. Later, the bone computed tomographic image was compared with the plan. The averaged deviations and the percentages of the points within 1 mm, 2 mm, and 3 mm deviations were recorded. Total and ischemic time were also recorded.Reconstruction points within 1 mm deviation were 59% of CAD/CAM group (n = 9) and 42% of conventional group (n = 10, P = 0.04), within 2 mm 82% and 69% (P = 0.03). Total time were 1012 and 911 minutes, while flap ischemic time were 147 and 175 minutes (P = 0.03), respectively.In-house CAD/CAM mandibular reconstruction also supported accuracy and shorter flap ischemic time. For a detailed accurate reconstruction, CAD/CAM showed superiority than conventional method. Use of the In-house CAD/CAM guides might be an option where commercial guides are not available.

Two Cases of the Vascular Territory of a Single-pedicled Deep Inferior Epigastric Perforator Flap with a Vertical Midline Abdominal Scar.

: The deep inferior epigastric perforator (DIEP) flap is becoming the gold standard for breast reconstruction using autologous tissue. If there are scars in the abdomen from previous surgery, it is necessary to judge the indication for using this flap carefully. Particularly in cases with vertical midline scars, the blood flow supply to the zone II can be compromised. Even when patients have a median abdominal scar, it has been reported that the blood flow can extend beyond the scar and reach several centimeters to about half of zone II. We performed breast reconstruction using DIEP flaps for 2 patients with vertical midline scars in the lower abdomen. Indocyanine green angiography was conducted intraoperatively to confirm the vascular territory with a single pedicle before cutting off the flap. One patient showed fluorescence contrast on the contralateral side across the midline scar. However, the fluorescence contrast was absent across the midline scar in the other patient. Based on this result, we investigated the possible vascular territory of a single pedicled DIEP flap in patients with vertical midline abdominal scars. We suggest that successful blood supply to zone II of a single-pedicled DIEP flap in a patient with a vertical midline abdominal scar is related to the location of the perforator and the property of the tissue in the midline near the perforator. However, because it is difficult to predict the vascular territory of a single pedicle before surgery, intraoperative evaluation using such techniques such as indocyanine green fluorescence imaging is important.

Predominant Role of Serotonin at the Hippocampal Mossy Fiber Synapse with Redundant Monoaminergic Modulation.

The hippocampal mossy fiber (MF) synapse has been implicated in the pathophysiology and treatment of psychiatric disorders. Alterations of dopaminergic and serotonergic modulations at this synapse are candidate mechanisms underlying antidepressant and other related treatments. However, these monoaminergic modulations share the intracellular signaling pathway at the MF synapse, which implies redundancy in their functions. We here show that endogenous monoamines can potentiate MF synaptic transmission in mouse hippocampal slices by activating the serotonin 5-HT4 receptor. Dopamine receptors were not effectively activated by endogenous agonists, suggesting that the dopaminergic modulation is latent. Electroconvulsive treatment enhanced the 5-HT4 receptor-mediated serotonergic synaptic potentiation specifically at the MF synapse, increased the hippocampal serotonin content, and produced an anxiolytic-like behavioral effect in a 5-HT4 receptor-dependent manner. These results suggest that serotonin plays a predominant role in monoaminergic modulations at the MF synapse. Augmentation of this serotonergic modulation may mediate anxiolytic effects of electroconvulsive treatment.

Skin ligation and argon beam coagulation for giant pachydermatocele resection.

Resection of giant neurofibroma in neurofibromatosis type 1 has a high risk of perioperative bleeding because the tumors are enriched in blood vessels, which are weakened due to the loss and thinning of vascular smooth muscle. Therefore, we combined skin ligation around the tumor and use of an argon beam coagulator (ABC) for hemostasis during resecting the giant neurofibroma. The ABC is a non-contact-type hemostasis device employing argon gas as a medium. We examined the usefulness of our method by retrospectively comparing the outcomes of the ABC-use group with those of the non-use group (7 patients, 9 tumors). Although there was no difference in resected tumor weight between the two groups, the operation time was slightly shorter and the volume of blood loss was smaller in ABC-use group than in the non-use group. Our method for hemostasis is easy and safe and is considered to be a useful method.

Medial Upper Lip Vermillion Reconstruction with a Labial Artery-based Cross-lip Vermillion Flap.

A defect of the central upper lip vermillion generally requires "like for like" reconstruction because this part of the upper lip can attract attention and has a unique structure and color. In this article, we report use of a labial artery-based horizontal long cross-lip flap for central upper lip vermillion reconstruction. In the first stage of surgery, a horizontal long vermillion flap from the lower lip starting at the left commissure with a vascular pedicle containing an inferior labial artery was raised and transposed to the upper vermillion defect. In the second stage, 12 days later, the pedicle was divided to complete the reconstruction. There were no postoperative complications in articulation or eating, and the patient was satisfied with the esthetic outcome. This surgical technique reduces microstomia and inconvenience in eating and speaking compared with a common horizontal cross-lip flap and provides better color- and texture-matched tissue compared to reconstruction using a tongue flap or mucosal flap. The technique is simple, requires a relatively short surgical time, has minimum donor-site morbidity and permits good esthetic and functional reconstruction of the central upper lip vermillion for a relatively small defect.

Objective evaluation of fat tissue induration after breast reconstruction using a deep inferior epigastric perforator (DIEP) flap.

Problems in breast reconstruction with deep inferior epigastric perforator (DIEP) flaps include postoperative fat induration and necrosis. A resulting clinical symptom is palpable indurated tissue, but it is difficult to measure the stiffness of transplanted fat tissues objectively at a deep site. The ability to perform shear-wave elastography (SWE) was recently added to some common ultrasonic echo devices, enabling objective three-dimensional measurements of tissue stiffness. In this study, we measured the stiffness of transplanted DIEP flaps using SWE to examine the effects of measurement sites, flap size and perforator patterns on stiffness. The subjects were 26 patients who showed induration of a transplanted flap on palpation in follow-up observation performed more than 6 months after breast reconstruction with a DIEP flap. The effects of the weight of the transplanted flap, and the diameter, number and location of the perforators on the stiffness of fat tissue were also analyzed. Within each zone, distal regions showed higher values, but in Zone II, significantly higher stiffness was also found in the proximal region. Multivariate regression analysis including all measurement sites, the weight of transplanted flap, and diameter, number and location of perforators showed that the stiffness of fat tissue was significantly higher in subjects with a larger weight flap. For safe reconstruction, it will be useful to examine the stiffness of fat tissue in individual regions of a transplanted flap retrospectively, because the examination results can be used in actual clinical practice.

Designing CAD/CAM Surgical Guides for Maxillary Reconstruction Using an In-house Approach.

Computer-aided design/computer-assisted manufacturing (CAD/CAM) is now being evaluated as a preparative technique for maxillofacial surgery. Because this technique is expensive and available in only limited areas of the world, we developed a novel CAD/CAM surgical guide using an in-house approach. By using the CAD software, the maxillary resection area and cutting planes and the fibular cutting planes and angles are determined. Once the resection area is decided, the necessary faces are extracted using a Boolean modifier. These superficial faces are united to fit the surface of the bones and thickened to stabilize the solids. Not only the cutting guides for the fibula and maxilla but also the location arrangement of the transferred bone segments is defined by thickening the superficial faces. The CAD design is recorded as .stl files and three-dimensionally (3-D) printed as actual surgical guides. To check the accuracy of the guides, model surgery using 3-D-printed facial and fibular models is performed. These methods may be used to assist surgeons where commercial guides are not available.

Using an In-House Approach to Computer-Assisted Design and Computer-Aided Manufacturing Reconstruction of the Maxilla.

PURPOSE: Computer-assisted design (CAD) and computer-aided manufacturing (CAM) techniques are in widespread use for maxillofacial reconstruction. However, CAD/CAM surgical guides are commercially available only in limited areas. To use this technology in areas where these commercial guides are not available, the authors developed a CAD/CAM technique in which all processes are performed by the surgeon (in-house approach). The authors describe their experience and the characteristics of their in-house CAD/CAM reconstruction of the maxilla. PATIENTS AND METHODS: This was a retrospective study of maxillary reconstruction with a free osteocutaneous flap. Free CAD software was used for virtual surgery and to design the cutting guides (maxilla and fibula), which were printed by a 3-dimensional printer. After the model surgery and pre-bending of the titanium plates, the actual reconstructions were performed. The authors compared the clinical information, preoperative plan, and postoperative reconstruction data. The reconstruction was judged as accurate if more than 80% of the reconstructed points were within a deviation of 2 mm. RESULTS: Although on-site adjustment was necessary in particular cases, all 4 reconstructions were judged as accurate. In total, 3 days were needed before the surgery for planning, printing, and pre-bending of plates. The average ischemic time was 134 minutes (flap suturing and bone fixation, 70 minutes; vascular anastomoses, 64 minutes). The mean deviation after reconstruction was 0.44 mm (standard deviation, 0.97). The deviations were 67.8% for 1 mm, 93.8% for 2 mm, and 98.6% for 3 mm. The disadvantages of the regular use of CAD/CAM reconstruction are the intraoperative changes in defect size and local tissue scarring. CONCLUSION: Good accuracy was obtained for CAD/CAM-guided reconstructions based on an in-house approach. The theoretical advantage of computer simulation contributes to the accuracy. An in-house approach could be an option for maxillary reconstruction.