The Potential of Chat-Based Artificial Intelligence Models in Differentiating Between Keloid and Hypertrophic Scars: A Pilot Study.

BACKGROUND: Lasting scars such as keloids and hypertrophic scars adversely affect a patient's quality of life. However, these scars are frequently underdiagnosed because of the complexity of the current diagnostic criteria and classification systems. This study aimed to explore the application of Large Language Models (LLMs) such as ChatGPT in diagnosing scar conditions and to propose a more accessible and straightforward diagnostic approach. METHODS: In this study, five artificial intelligence (AI) chatbots, including ChatGPT-4 (GPT-4), Bing Chat (Precise, Balanced, and Creative modes), and Bard, were evaluated for their ability to interpret clinical scar images using a standardized set of prompts. Thirty mock images of various scar types were analyzed, and each chatbot was queried five times to assess the diagnostic accuracy. RESULTS: GPT-4 had a significantly higher accuracy rate in diagnosing scars than Bing Chat. The overall accuracy rates of GPT-4 and Bing Chat were 36.0% and 22.0%, respectively (P = 0.027), with GPT-4 showing better performance in terms of specificity for keloids (0.6 vs. 0.006) and hypertrophic scars (0.72 vs. 0.0) than Bing Chat. CONCLUSIONS: Although currently available LLMs show potential for use in scar diagnostics, the current technology is still under development and is not yet sufficient for clinical application standards, highlighting the need for further advancements in AI for more accurate medical diagnostics. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online instructions to authors www.springer.com/00266 .

Artery first and declamp it: A temporary revascularization method during microvascular anastomosis: A retrospective case series study.

BACKGROUND: The optimal sequence of microvascular clamping during free flap transfer is yet to be established. Many surgeons are reluctant to perform temporary declamping and subsequent reclamping during microvascular anastomosis; however, we generally anastomose the artery first and temporarily declamp it before performing venous anastomosis to confirm arterial patency and ensure proper alignment of the flap veins. Herein, we aimed to retrospectively investigate the efficacy and safety of this temporary revascularization method in 126 patients who underwent microvascular head and neck reconstruction. METHODS: A total of 127 free flaps were transferred, with the anterolateral thigh flap (49 flaps) being the most frequently used. The internal jugular vein was the most frequently used recipient vein and end-to-side anastomoses to it were performed in 112 patients. RESULTS: Intraoperative reanastomosis was required because of arterial thrombosis in 5 cases (4.0%), arterial and venous thrombosis in 1 case (0.8%), injury to the flap artery distal to the anastomotic site in 1 case (0.8%), and venous twisting in 1 case (0.8%). Postoperatively, all the flaps survived without microvascular compromise. CONCLUSIONS: Vascular kinking or twisting of the vascular pedicle is a major cause of free flap failure. However, it is difficult to place empty vessels accurately during clamping. Nonetheless, temporary revascularization engorges the flap vein before venous anastomosis and minimizes the risk of venous kinking and twisting. According to our results, reclamping did not increase the risk of arterial thrombosis.

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.

Nonreversed great saphenous vein grafts for vascular reconstruction after resection of lower-limb sarcoma.

OBJECTIVE: Reversed great saphenous vein (GSV) graft is widely used for revascularization in limb-sparing surgery for sarcoma invading great vessels. However, a mismatch in caliber between the reverse graft and cut end of the artery can threaten graft patency. Recently, we introduced the use of a venous valvulotome to allow nonreversed GSV graft. The purpose of this study was to evaluate the safety and versatility of this technique. DESIGN: We retrospectively compared long-term patency and limb salvage rates between nonreversed GSV and reversed GSV in patients undergoing limb-sparing surgery for sarcoma. METHODS: Thirty-seven patients were included, with 21 in the nonreversed GSV group and 16 in the reversed GSV group. Patient characteristics, surgical details, and complications were reviewed from the hospital records. The patency of the reconstructed vessels was assessed using contrast-enhanced CT or MRI. Statistical analyses, including Kaplan-Meier survival analysis, were employed for comparisons. RESULTS: The median follow-up was 38 months. Overall graft patency was 90.4% (19 of 21 patients) in the nonreversed GSV group and 81.2% (13 of 16) in the reverse GSV (RGSV) group. In the nonreversed GSV group, there was 1 case of graft occlusion each in the acute and chronic phases, but limb circulation remained intact and all limbs were spared. CONCLUSION: Nonreversed GSV grafting with valvulotome offers a safe and versatile alternative to reversed GSV grafts in limb-sparing sarcoma surgery. It eliminates the need for vein reversal and minimizes diameter mismatch, potentially expanding the indication for autologous revascularization to previously ineligible cases.

Negative Pressure Wound Therapy with Instillation and Dwell Time for Pharyngocutaneous Fistula.

Pharyngocutaneous fistula is a critical complication of head and neck cancer reconstruction and it is often difficult to manage. We herein report two cases of pharyngocutaneous fistulas that developed after oropharyngeal reconstruction and were successfully treated with negative pressure wound therapy with instillation and dwell time (NPWTi-d), an advanced form of traditional NPWT. NPWTi-d may be a useful nonsurgical treatment for pharyngocutaneous fistula. Laryngoscope, 2024.

Reconstruction techniques using free jejunal transfer for total pharyngolaryngectomy with total glossectomy.

BACKGROUND: Total pharyngolaryngectomy is sometimes combined with total glossectomy for advanced hypopharyngeal or cervical esophageal cancers involving the tongue base. The optimal reconstruction method for total pharyngolaryngectomy with total glossectomy has not been established due to a considerable diameter mismatch between the floor of mouth and the esophageal stump. This report describes two reconstruction methods using free jejunal transfer. METHODS: Five consecutive patients who underwent total pharyngolaryngectomy with total glossectomy were included, with a mean age of 67.0 (range 55-75) years. Primary tumors included tongue, hypopharyngeal, cervical esophagus, and laryngeal cancers. The mean defect size was 17.0 (16-19) × 6.8 (6-7) cm. Surgical techniques involved either a simple incision or a two-segment method to address the size mismatch between the jejunum and the floor of mouth. In the simple incision method, a longitudinal cut was made to the antimesenteric or paramesenteric border of a jejunum wall to expand the orifice. In the two-segment method, a jejunal graft was separated into two segments to reconstruct the floor of mouth and the cervical esophagus, and these segments were connected with a longitudinal incision to the cervical esophageal segment to form a funnel-shaped conduit. RESULTS: Of the five patients, three underwent the simple incision method and two the two-segment method. Postoperative pharyngoesophagography showed a smooth passage for all patients. Postoperative courses were uneventful except for one flap loss due to arterial thrombosis. Four patients achieved oral feeding, while one became gastric-tube dependent. At a mean follow-up of 22.1 (4-39) months, one patient required tube feeding, two tolerated full liquid, and two consumed a soft diet. CONCLUSIONS: Both the simple incision and two-segment methods achieved satisfactory swallowing function. The choice between these reconstruction methods may depend on the extent of resection of the posterior pharyngeal wall.

Evaluation of aesthetic outcomes of mandibular reconstruction using artificial intelligence.

BACKGROUND: Although vascularized bone graft (VBG) transfer is the current standard for mandibular reconstruction, reconstruction with a mandibular reconstruction plate (MRP) and with a soft-tissue flap (STF) alone remain crucial options for patients with poor general conditions. However, objective aesthetic outcome evaluations for these methods are limited. METHODS: In a retrospective analysis of 65 patients (VBG, 33; MRP, 19; and STF, 13), mandibular asymmetry value was calculated for each patient's photograph using facial recognition AI, with a higher value indicating worse asymmetry. RESULTS: The MRP group had a value comparable to the VBG group regardless of mandibular defect types. The STF group had a significantly higher value than the VBG group. CONCLUSIONS: Regarding cosmesis, STF was inferior to VBG, whereas MRP was comparable to VBG, even for anterior defects for which rigid reconstruction is mandatory. However, MRP's risks of plate-related complications limit its use to cases where VBG is contraindicated or with poor prognosis.

Scapula harvest in the supine position for immediate mandibular reconstruction.

PURPOSE: The scapula is the second most popular donor site for mandibular reconstruction after the fibula. Scapula harvest is generally performed in the lateral decubitus position and the requirement of positional changes hamper the widespread use of the scapula. This study compared scapula harvest for immediate mandibular reconstruction between the supine and lateral decubitus positions. METHODS: We reviewed the outcomes of 16 patients who underwent segmental mandibulectomy and immediate reconstruction of the scapula based on the angular branch of the thoracodorsal artery. The scapula was harvested in the lateral decubitus (lateral decubitus group) or supine position (supine group) in eight patients each. Several perioperative parameters were compared between the two groups. RESULTS: One scapula was lost because of inadvertent injury of the angular branch in the supine group. The operative time was significantly shorter in the supine group than in the lateral decubitus group. CONCLUSION: Harvesting of the scapula in the supine position is a feasible option for immediate mandibular reconstruction. Although deep anatomic knowledge and technical expertise are necessary, this strategy can eliminate positional change and significantly reduce the operative time.

Soft tissue Reconstruction Using Pedicled Trapezius Musculocutaneous Flap for Cranial Bone Flap Infection in the Occipital Region.

When managing cranial bone flap infections, infected bone flaps are typically removed and subsequently replaced with artificial bones 6 to 12 months after the inflammation subsides. However, defects in the occipital region pose challenges due to concerns regarding brain protection when patients lie in the supine position. Herein, the authors report the case of a 73-year-old woman with an occipital bone flap infection, which was successfully managed by reconstruction with a trapezius musculocutaneous flap immediately after removing the infected bone flap. One year and 2 months postoperatively, the wound had fully healed, and the patient remained symptom-free without any complications, such as sunken flap syndrome. Soft tissue reconstruction using pedicled trapezius musculocutaneous flap is a viable strategy for managing occipital bone flap infections. This flap ensures stable blood flow and requires minimal vascular manipulation, thereby reducing operation time as the patient does not need to change position.

Machine learning approach to predict tracheal necrosis after total pharyngolaryngectomy.

BACKGROUND: Tracheal necrosis is a potentially severe complication of total pharyngolarynjectomy (TPL), sometimes combined with total esophagectomy. The risk factors for tracheal necrosis after TPL without total esophagectomy remain unknown. METHODS: We retrospectively reviewed data of 395 patients who underwent TPL without total esophagectomy. Relevant factors associated with tracheal necrosis were evaluated using random forest machine learning and traditional multivariable logistic regression models. RESULTS: Tracheal necrosis occurred in 25 (6.3%) patients. Both the models identified almost the same factors relevant to tracheal necrosis. History of radiotherapy was the most important predicting and significant risk factor in both models. Paratracheal lymph node dissection and total thyroidectomy with TPL were also relevant. Random forest model was able to predict tracheal necrosis with an accuracy of 0.927. CONCLUSIONS: Random forest is useful in predicting tracheal necrosis. Countermeasures should be considered when creating a tracheostoma, particularly in patients with identified risk factors.

Transverse Cervical Artery for Head and Neck Reconstruction with Free Jejunal Flaps: A Retrospective Study of Computed Tomography Angiography.

BACKGROUND: The transverse cervical artery is less commonly used than other external carotid arteries as a recipient vessel. Therefore, we aimed to compare the utility of the transverse cervical artery as a recipient vessel with that of the external carotid artery system for microvascular head and neck reconstruction by quantitative analysis of dynamic-enhanced computed tomography. METHODS: Fifty-one consecutive patients who underwent free jejunum transfer following total pharyngolaryngectomy between January 2017 and December 2020 were retrospectively reviewed. Ninety-four pairs of the diameters of the transverse cervical artery, superior thyroid artery, and lingual artery, measured via computed tomography angiography, were analyzed. Operative outcomes were compared between the following groups based on the recipient artery: transverse cervical artery (n = 27), superior thyroid artery (n = 17), and other artery (n = 7) groups. RESULTS: In the analysis of the computed tomography angiography, nine transverse cervical arteries (9.6%) could not be identified. However, the percentage was significantly lower than the percentage of superior thyroid arteries (20.2%) and lingual arteries (18.1%) (p < 0.01). Among the identified vessels, the transverse cervical arteries (2.09 ± 0.41 mm) and the lingual arteries (1.97 ± 0.40 mm) were significantly larger than the superior thyroid arteries (1.70 ± 0.36 mm) in diameter at the commonly used level (p < 0.01). Multivariate analysis revealed that prior radiation therapy was not an independent factor significantly affecting transverse cervical artery diameter (p = 0.17). Intraoperative anastomotic revision was required in only two cases of the superior thyroid artery. CONCLUSION: The transverse cervical artery can offer a larger caliber and more reliable candidate than the superior thyroid artery for a recipient artery. More liberal use of the transverse cervical artery may improve the safety of microsurgical head and neck reconstruction.

Simultaneous reconstruction of smiling eye using V-shaped long latissimus dorsi muscle transfer in patients with flaccid facial paralysis.

Various neurovascular free muscle transfers for smile reconstruction in patients with facial paralysis have been reported. However, these methods focused on peri-oral smiling rather than eye smiling. Although the lower eyelid does not contribute significantly to eyelid closure, dynamic reanimation of the upward movement of the lower eyelid, with bulging of the malar region, during smiling is important in smile reconstruction. Herein, we present a novel procedure for smiling eye and peri-oral smiling. The V-shaped latissimus dorsi muscle flap containing the descending branch (DB) of the thoracodorsal nerve (TDN) was employed. Muscle-A (15-17 cm), which is located along the main trunk of the DB, is much longer than muscle-B (10-12 cm), which is along the branch of DB. A distal stump of the TDN involved in muscle-B was prepared. The true trunk and distal stump of the TDN were sutured to the contralateral facial and ipsilateral masseteric nerves, respectively. The central region of muscle-A was positioned at the lateral part of the lower eyelid; the distal end of long muscle-A was affixed to the temporal region, which enabled peri-ocular movements and narrowing of the palpebral fissures alongside peri-oral smiling when muscle-A contracted. Nine patients with complete flaccid facial paralysis were treated. All patients attained muscle contraction induced by the ipsilateral masseteric and contralateral facial nerves. The smiling eye atmosphere was observed in seven of nine patients. This procedure simultaneously improves paralytic ectropion at rest and aids eyelid closure and enables early voluntary smile and a later spontaneous smile.

Vascularized Fibular Grafts for Failed Liquid Nitrogen-treated Autografts in the Humerus: Report of Two Cases.

With advances in chemotherapy and surgical techniques, limb salvage and biological reconstruction, including autologous bone grafting, have become the preferred treatment options for primary malignant bone tumors of the extremities. Although autografts, which involve recycling of tumor-bearing bones, have the advantages of easy accessibility and anatomical matching, fracture is a frequent major complication. However, to our knowledge, salvage of refractory autograft failure has not yet been reported. This report describes free vascularized fibular graft implantation for salvaging failed previous reconstructions. We describe two patients (a 4-year-old girl and a 30-year-old man, respectively) with primary malignant bone tumors. Liquid nitrogen-treated autografts had been used to reconstruct the humerus in both cases. The patients sustained autograft fractures that could not be treated conservatively or by internal fixation. Free vascularized fibular grafts were transferred as double-barrel inlay grafts (length 7.2 and 8.2 cm) and a single-strut onlay graft (length 16 cm). The brachial arteries, brachial veins, and cephalic veins were used as recipient vessels. Bone union between the fibular grafts and humerus was achieved after 29 and 15 months of follow-up, respectively. In conclusion, free vascularized fibular grafts can be used to salvage refractory autograft fractures.

Soft Tissue Reconstruction Using the Free Forearm Fillet Flap in the Salvage of Forequarter Amputations for Recurrent Sarcoma: A Report of 2 Cases.

ABSTRACT: Reconstruction after radical forequarter amputation for recurrent proximal extremity sarcoma is challenging because the defect is significant, and the axillary or subclavian vessels are resected with the tumor, indicating that the pedicle of nearby flaps is often cut off. Free flaps are commonly used to cover the defect, but the donor site morbidity is problematic. Another problem with resecting the axillary or subclavian vessels is difficulty obtaining recipient vessels with matching calibers for another free flap. The authors presented 2 cases that successfully solved all these problems by covering the defects by the forearm fillet flaps.The forearm fillet flap has the advantage of using a portion that is usually discarded, so there is no donor site morbidity. Moreover, using the brachial artery as the pedicle of the flap allows the anastomosis to the stump of the resected axillary or subclavian artery because differences in caliber are slight.The use of the forearm fillet flaps has been reported less frequently than the fillet flaps in the lower extremities, and most cases are posttraumatic. In cases of trauma, complications are reported to occur in about 1 in 4 patients, but in cases after tumor resection, ischemic time can be controlled, and there are no risks of contamination or unnoticed forearm damage, so more stable results can be expected as in this report.Using the free flap from the distal portion of the resected upper limb, especially in cases with a short prognosis, is a viable option that effectively minimizes damage to the donor site and maintains quality of life.

A Novel Risk Model for Predicting Dysphagia after Tongue Reconstruction: A Retrospective Multicenter Study in Japan.

BACKGROUND: There is no consensus on the postoperative outcomes of tongue reconstruction. Therefore, the authors developed a novel risk model for predicting dysphagia after tongue reconstruction. METHODS: This retrospective study was conducted by the Oral Pharyngeal Esophageal Operation and Reconstruction Analytical, or OPERA, group across 31 cancer centers and university hospitals in Japan. A total of 532 patients [390 (73.3%) men and 142 (26.7%) women; median age at surgery, 60 years (range, 15 to 88 years)] who were diagnosed with oral tongue squamous cell carcinoma and underwent tongue reconstruction following glossectomy between 2009 and 2013 were included. Independent risk factors were identified using univariate regression analysis and converted to a binary format for multivariate analysis. An integer value was assigned to each risk factor to calculate a total score capable of quantifying the risk of feeding tube dependence. RESULTS: Overall, 54 patients (10.2%) required a feeding tube at the time of evaluation. Predictive factors for feeding tube dependence were advanced age, lower American Society of Anesthesiologists physical status, low body mass index, lower serum albumin, comorbid hypertension and diabetes, extended tongue defect, resection beyond the tongue, laryngeal suspension, postoperative radiation therapy, and no functional teeth. In multivariate logistic regression analysis, age greater than or equal to 58.5 years, postoperative radiation therapy, wider tongue defect, and body mass index less than 21.27 kg/m 2 earned 6, 4, 3, and 2 points, respectively, for a maximum total score of 15. CONCLUSION: The authors' risk model provides a mathematical tool for estimating the individual risk of postoperative feeding tube dependence before tongue reconstruction. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, III.

Internal jugular vein reconstruction using a triple-paneled great saphenous vein graft.

BACKGROUND: Donor-recipient diameter discrepancy can be problematic when using an autologous great saphenous vein graft for internal jugular vein reconstruction. A triple-paneled method of saphenous vein grafting is one solution. CASE PRESENTATION: A 54-year-old man with a thyroid papillary carcinoma underwent total thyroidectomy and bilateral neck dissection. An 8-cm segment of the right internal jugular vein was resected. For reconstruction, a 30-cm segment of the great saphenous vein was harvested and divided into three pieces of equal length. After opening each piece longitudinally, they were sutured together in a side-by-side fashion to create a cylinder that was used to reconstruct the internal jugular vein defect. The graft was patent 10 months after the surgery. CONCLUSION: The triple-paneled method is feasible for autologous great saphenous vein graft reconstruction of the internal jugular vein.