Influence of Flap Parameters on the Aerodynamic Performance of a Wind-Turbine Airfoil

A numerical method has been used to analyze the flow field related to a NACA 0015 airfoil with and without a flap and assess the influence of the flap height and angle on the surface pressure coefficient,lift coefficient,and drag coefficient.The numerical results demonstrate that the flap can effectively improve the lift coefficient of the airfoil;however,at small attack angles,its influence is significantly reduced.When the angle of attack exceeds the critical stall angle and the flap height is 1.5%of the chord length,the influence of the flap becomes very evident.As the flap height increases,the starting point of the separation vortex gradually moves forward and generates a larger wake vortex.Optimal aerodynamic characteristics are obtained for 1.5%(of the chord length)flap height and a 45°flap angle;in this case,the separation vortex is effectively reduced.

Nasal flap preservation in endoscopic dacryocystorhinostomy for nasolacrimal duct obstruction

AIM:To compare surgical outcomes between the conventional endoscopic dacryocystorhinostomy(DCR)and a modified endoscopic DCR for the treatment of nasolacrimal duct obstruction(NLDO),and evaluate factors associated with the surgical success rate.METHODS:Medical records of patients who underwent primary DCR surgery between January 2016 and July 2020 at the Otorhinolaryngology Department of Eye and Ear International Hospital,Lebanon were reviewed.RESULTS:The study group consisted of 50 consecutive modified endoscopic DCR and the control group consisted of 138 consecutive conventional endoscopic DCR.The success rates at 1y were 98.0%(49 out of 50)for modified DCR,significantly higher compared to 84.8%(117/138)for the conventional DCR;there was no significant difference in the success rate throughout the years in terms of both surgical techniques.The modified surgery vs traditional[adjusted odds ratio(aOR)=14.96]and having an adjunctive septoplasty surgery vs not(aOR=3.99)were significantly associated with higher odds of success.CONCLUSION:Mucosal flap preservation and apposition shows significant improvement in the surgical success rate.Moreover,there is no statistically significant difference found in terms of complication rate and mean operative time between the conventional and the modified techniques.

Impact of Blade-Flapping Vibration on Aerodynamic Characteristics of Wind Turbines under Yaw Conditions

Although the aerodynamic loading of wind turbine blades under various conditions has been widely studied,the radial distribution of load along the blade under various yaw conditions and with blade flapping phenomena is poorly understood.This study aims to investigate the effects of second-order flapwise vibration on the mean and fluctuation characteristics of the torque and axial thrust of wind turbines under yaw conditions using computational fluid dynamics(CFD).In the CFD model,the blades are segmented radially to comprehensively analyze the distribution patterns of torque,axial load,and tangential load.The following results are obtained.(i)After applying flapwise vibration,the torque and axial thrust of wind turbines decrease in relation to those of the rigid model,with significantly increased fluctuations.(ii)Flapwise vibration causes the blades to reciprocate along the axial direction,altering the local angle of attack and velocity of the blades relative to the incoming wind flow.This results in the contraction of the torque region from a circular shape to a complex“gear”shape,which is accompanied by evident oscillations.(iii)Compared to the tangential load,the axial load on the blades is more sensitive to flapwise vibration although both exhibit significantly enhanced fluctuations.This study not only reveals the impact of flapwise vibration on wind turbine blade performance,including the reduction of torque and axial thrust and increased operational fluctuations,but also clarifies the radial distribution patterns of blade aerodynamic characteristics,which is of great significance for optimizing wind turbine blade design and reducing fatigue risks.

Pedicled abdominal flap using deep inferior epigastric artery perforators for forearm reconstruction: A case report

BACKGROUND Pedicled abdominal flaps are a widely used surgical technique for forearm reconstruction in patients with soft tissue defects.However,some drawbacks include restricted flap size,partial flap loss,and donor-site morbidity.To address these concerns,we present a case of a pedicled abdominal flap using the deep inferior epigastric artery perforators(DIEP)for forearm reconstruction in a patient with a large soft tissue defect.CASE SUMMARY A 46-year-old male patient was admitted to our hospital with forearm injury caused by a pressing machine.A 15 cm×10 cm soft tissue defect with complete rupture of the ulnar side structures of the forearm was found.One week after orthopedic management of the neurovascular injury and fractures using the first stage of Masquelet technique,the patient was referred to the plastic and recon-structive surgery department for wound coverage.Surgical debridement and negative-pressure wound therapy revealed a 20 cm×15 cm soft tissue defect.A pedicle abdominal flap with the DIEP was used to cover the defect.Three weeks later,the flap was detached from the abdomen,and the abdominal defect was directly closed.Subsequently,the second stage of Masquelet technique was performed at the fracture site at week 10.Finally,all donor and recipient sites healed without complications,such as flap dehiscence,infection,hematoma,or necrosis.Fracture site osteosynthesis was achieved without complications.CONCLUSION Pedicled abdominal flap using the DIEP provides a reliable option for forearm reconstruction in patients with large soft tissue defects.

Evaluation of the versatility of perforators-enhanced rhomboid flap technique for ischial sores reconstruction

Background: Prolonged pressure on the skin known as pressure sores, can cause frequent injuries to the skin and underlying tissues. However, several prevention approaches, including non-surgical and surgical management,are available. In flap surgery for pressure sores, a variety of flap types may be used;each offers certain benefits and some incidences of complications and recurrence. This study evaluated the versatility of the perforatorenhanced rhomboid flap technique for ischial sore construction.Methods: This prospective study was conducted in the Plastic Surgery Department of Fayoum University Hospital.The perforator-enhanced rhomboid flap technique was employed in 20 patients with ischial pressure sores who failed to respond to conservative treatment. A proper history was obtained and a preoperative arterial duplex was performed to determine the site of the prominent perforators for their preservation at the base of the flap.Postoperative follow-ups and evaluations were performed.Results: The mean age of the study group was 43.7 ± 13.1, ranging from 19 to 65 years. Moreover, 80% of the participants were males while 20% were female. The main etiology of the sores was paraplegia in 45% of cases.The mean surface area of sores was 24.8 ± 6.3 cm2. In 75% of cases, the color match of the flap was rated as excellent. Similarly, 70% of the patients rated flap thickness as excellent. In 55% of the cases, the scar appearance was deemed excellent. Overall satisfaction was reported as excellent by 40% of the patients, while only 5% reported poor satisfaction. Approximately, 10% of the cases were identified with seroma, and 30% had wound dehiscence of a mean size of 1.33 ± 0.98 cm and required around 6.8 ± 1.9 weeks to heal.Conclusion: The perforator-enhanced rhomboid flap technique is a versatile method for reconstructing ischial pressure sores owing to its technical ease, short operative time, reliable vascularity, aesthetic outcome, matching skin color, and short recovery time. The main limitations include large defects with large surface areas, lack of a nearby donor site for a rhomboid flap, and scarring from prior procedures around the sore.

Adaptability of bipedicled scalp advancement flap for coverage of huge scalp defects after tumor resection

Background:Several reconstructive techniques have been used to reconstruct scalp defects.Numerous researchers have studied the utilization of bipedicled scalp advancement flaps for scalp defect coverage.In this study,we will assess the adaptability of a bipedicled scalp advancement flap for coverage of huge scalp defects after tumor resection.Methods:This study was performed at the Plastic Surgery Department,Fayoum University Hospital,on 20 patients with huge scalp tumors treated by adequate excision and reconstructed using a bipedicled scalp advancement flap from December 2021 to July 2023.Results:The study was conducted on 20 patients:16(80%)were men and 4(20%)were women presenting with large scalp tumors.The mean age was 57.4 years(33-68 years).The sites of the tumors were 10(50%)occipital,6(30%)parietal,and 4(20%)parieto-occipital.No major complications occurred postoperatively,and the bipedicled flaps survived well in all cases,with no necrosis.Conclusion:Huge scalp defects after tumor resection can be safely reconstructed with a large versatile bipedicled advancement scalp flap,either transversely or longitudinally oriented,with favorable functional results and accepted aesthetic results,apart from the alopecic area over the grafted donor site,which can be treated by tissue expansion if desired later.

Lateral circumflex femoral artery perforator flap for the reconstruction of head soft tissue defects:Cross-region venous anastomosis

Background:Owing to its unique characteristics,the lateral circumflex femoral artery perforator(LCFAP)flap is often preferred for repairing head wounds with exposed skulls.However,given the vascular distribution in the head,particularly the veins,can lead to postoperative complications such as venous congestion of the flap.The rates of vascular exploration and necrosis in these flaps are significantly higher than in other body regions.Therefore,it is crucial to identify a safe and effective method for venous anastomosis of free flaps in the head region.Methods:This retrospective case series study included 10 patients with large head soft tissue defects treated at the Burn and Plastic Surgery Department of the Affiliated Hospital of Zunyi Medical University from January 2020 to December 2022.The head defects were reconstructed using LCFAP flaps,with flap veins anastomosed to the external jugular vein in the neck,either directly or via a bridging technique.Results:Among the 10 adult patients with massive head wound defects,7(70%)were men.The patients’mean age was 53.0 years(48–59 years).The wound defects were caused by trauma in 6(60%)patients and by tumors in 4(40%)patients.Postoperatively,no significant complications occurred,and all LCFAP flap survived without necrosis.Conclusion:The descending branch of the LCFAP flap effectively repairs massive head wound defects.The venous anastomosis method for this flap is associated with a low incidence of venous complications and a high patency rate,making it a clinically valuable reference.

When the Combination of a Chinese Flap and Dufourmentel Makes It Possible to Treat a Hopeless Case of Squamous Cell Carcinoma of the Upper Lip

Cancers of the lip are the leading cause of labial defects, and treatment is essentially surgical. The success of a repair is assessed by two essential criteria: The functional character of the lip (restoration of continence allowing feeding) and the aesthetic quality of the repair. However, for many patients from countries whose medical infrastructure does not allow them to undertake complex reconstructions locally, medical transfers represent their only chance of treatment. The aim of this article is to share with you an extreme clinical case of labial reconstruction, the management of which was a real challenge, using two major flaps: the free ante-brachial flap and the DUFOURMENTEL-type bi-pediculated scalp flap.

Management of Square Carcinoma of the Lower Lip Using Camille-Bernard Flap under Local Anesthesia: When Constraints Dictate Our Attitude

Introduction: Squamous cell carcinomas of the lip essentially pose a therapeutic management problem. In the West, their treatment is done under general anesthesia and follows the classic rules of oncology. In our context of exercise, we sometimes have a different attitude dictated by various constraints. Observation: 55-year-old patient with no notable history, seen in consultation for a very large ulcerative-budding lesion on the right 2/3 of the lower lip with mucocutaneous involvement without lymph node findings found on examination. Faced with this suspicious lesion and the patient’s financial difficulties, we decided to operate under local anesthesia to remove this tumor. The oncological excision was followed by immediate plasty using a Camille-Bernard flap with a good immediate aesthetic and functional result and postoperative day 7. The patient was unable to take his surgical specimen to anatomy-pathology and was lost to follow-up due to lack of financial resources. On anatomo-pathological analysis of the surgical specimen, the margins were healthy with confirmation of squamous cell carcinoma (anapathological reading made for scientific interest). Discussion: The particular mentality of certain patients and their difficult financial conditions push us to have an unconventional therapeutic attitude in oncology, but which nevertheless makes it possible to resolve certain problems that we often face. Local anesthesia is possible and realistic in cases like ours and the results can be acceptable and life-saving.

Thrust Optimization of Flapping Wing via Gradient Descent Technologies

The current work aims at employing a gradient descent algorithm for optimizing the thrust of a flapping wing. An in-house solver has been employed, along with mesh movement methodologies to capture the dynamics of flow around the airfoil. An efficient framework for implementing the coupled solver and optimization in a multicore environment has been implemented for the generation of optimized solutionsmaximizing thrust performance & computational speed.

Utility of Preoperative Positron Emission Tomography (PET) in Localizing Perforator Vessels of Anterolateral Thigh Free Flap

Objectives: The anterolateral thigh (ALT) flap is often considered the workhorse in soft tissue reconstruction of head and neck defects secondary to trauma, infection, or tumor resection. Despite its many advantages, ALT flaps have been criticized due to variability in vasculature, which may result in inadequate or non-existent perforators. This retrospective study aims to investigate the utility and validity of positron emission tomography (PET) scan to identify the location and characteristics of perforators to the ALT flap. Methods: We performed a 10-year retrospective review of ALT flaps at our institution to identify patients with preoperative PET scans available for analysis. Three reviewers (attending physician, fellow, and resident) were asked to identify the number, location, and characteristics (myocutaneous versus septocutaneous) of ALT perforators on imaging, and reviewer agreement was assessed. Results were then compared to available operative data. Results: One hundred twenty-one patients were identified who underwent ALT free flap surgery. Thirty-eight preoperative PET scans were identified for review. At least one perforator was identified in 92.1% of scans. Agreement percentages regarding the number of perforators ranged from 53% - 61% whereas agreement regarding the location of a single perforator ranged from 79% - 90%. However, reviewers did not agree regarding the type of perforator, with agreement ranging from 34% - 53%. Poor agreement was observed when compared to intraoperative data, with the number of perforators ranging from 26% - 34% and the type of perforator 11% - 24%. These findings are likely due to insufficient data available in operative reports. Conclusion: Although initial studies suggest that PET scan shows promising evidence to support the capacity to preoperatively identify ALT perforators, future prospective studies are warranted to fully validate these findings.

Sternocleidomastoid flap for reconstruction of tongue small cell carcinoma: A case report

BACKGROUND The management of tongue carcinoma is excision and radical neck dissection followed with reconstruction.This is a case report of a patient with tongue squamous cell carcinoma(SCC)who underwent the procedure with sternocleidomastoid(SCM)flap reconstruction.CASE SUMMARY A 52-year-old woman without smoking history complained tongue ulcer since 3 years ago.Based on the histopathological examination,the patient was diagnosed with T2N2M0 right tongue SCC and underwent wide excision of tumor;right mandibular;neck dissection and were reconstructed with SCM flap.CONCLUSION SCC of the tongue requires wide excision and dissection of the neck and mandible if infiltration into the surrounding lymph nodes has been found.The SCM flap reconstruction could be used post-surgery.

“In situ bone flap” combined with vascular pedicled mucous flap to reconstruction of skull base defect

BACKGROUND At present,neuroendoscopy technology has made rapid development,and great progress has been made in the operation of lesions in the saddle area of the skull base.However,the complications of cerebrospinal fluid and intracranial infection after the operation are still important and life-threatening complications,which may lead to poor prognosis.AIM To investigate the method of in situ bone flap combined with nasal septum mucosal flap for reconstruction of enlarged skull base defect by endonasal sphenoidal approach and to discuss its application effect.METHODS Clinical data of 24 patients undergoing transnasal sphenoidal endoscopic approach in the Department of Neurosurgery,Affiliated 2 Hospital of Nantong University from January 2019 to December 2022 were retrospectively analyzed.All patients underwent multi-layer reconstruction of skull base using in situ bone flap combined with nasal septum mucosa flap.The incidence of intraoperative and postoperative cerebrospinal fluid leakage and intracranial infection were analyzed,and the application effect and technical key points of in situ bone flap combined with nasal septum mucosa flap for skull base bone reconstruction were analyzed.RESULTS There were 5 cases of high flow cerebrospinal fluid(CSF)leakage and 7 cases of low flow CSF leakage.Postoperative cerebrospinal fluid leakage occurred in 2 patients(8.3%)and intracranial infection in 2 patients(8.3%),which were cured after strict bed rest,continuous drainage of lumbar cistern combined with antibiotic treatment,and no secondary surgical repair was required.The patients were followed up for 8 to 36 months after the operation,and no delayed cerebrospinal fluid leakage or intracranial infection occurred during the follow-up.Computed tomography reconstruction of skull base showed satisfactory reconstruction after surgery.CONCLUSION The use of in situ bone flap combined with vascular pedicled mucous flap to reconstruction of skull base defect after endonasal sphenoidal approach under neuroendoscopy has a lower incidence of cerebrospinal fluid leakage and lower complications,which has certain advantages and is worthy of clinical promotion.

Salvage anastomosis in free PAP-flap breast reconstruction:What about free flap neovascularization?

Since the emergence of microsurgery in reconstructive surgery, free flaps have become a key tool in the management of patients with breast cancer. One such flap is the profunda artery perforator(PAP) flap. To date,there is no scientific consensus on whether voluminous free flaps remain dependent on their vascular pedicle throughout their lifespan. Therefore, the pedicle should always be carefully protected during revision surgery.In this article, we review the case of a middle-aged woman who suffered a pedicle transection needing reanastomosis during revision surgery six months after free-flap breast reconstruction. A 52-year-old woman who noticed a firm nodule in her right breast and armpit was referred to our department for surgical management. The Caucasian woman presented with no significant medical history or symptoms at the first consultation. Ultrasound-guided biopsy confirmed an invasive grade Ⅲ lobular carcinoma. Following staging,the patient underwent neoadjuvant chemotherapy before a right mastectomy with a complete homolateral axillary lymph node dissection and postoperative radiotherapy. One year after completing radiotherapy, free flap reconstruction with a PAP flap was performed, and six months later, revision surgery was required to enhance the volume of the reconstructed breast with a tissue expander and later an implant. Unfortunately,pedicle transection occurred during revision surgery, causing complete devascularization of the flap, which was confirmed by intraoperative Indocyanine Green imaging. The authors elected to perform salvage reanastomosis during the surgery. In keeping with the author’s 23-year experience with free flaps, the vascular pedicle should always be preserved in voluminous free flaps, as neovascularization alone may not ensure whole flap survival. The authors suggest always attempting re-anastomosis if vessels are compromised during revision surgery.

Nasal sill reconstruction with the Abbe flap after skin cancer resection:A case report

Local flaps are widely known as the best option for partial nasal reconstructions depending on donor tissue laxity,vascularization,and defect shape and size.The nasolabial flap is used more often in the nasal sill.For larger defects,greater tissue mobilization with larger scars or free flaps is required.Historically,the Abbe flap has been used for lip reconstruction in patients with cleft lip deformities.It allows less retraction than other local flaps or skin grafts in patients with large defect sizes and great defect depths.This study reported on the application of the Abbe flap for nasal sill reconstruction on a 71-year-old female patient with nasal sill basal cell carcinoma who had undergone resection surgery with a posterior lip switch operation with satisfactory results.The application of the Abbe flap could be considered in patients with multiple previous surgeries and at risk for necrosis.

Supraclavicular artery island flap for reconstruction of hypopharynx and upper esophagus defects:A case report and literature review

We report a case of a 74-year-old female with hypopharyngeal cancer who developed a pharyngoesophageal fistula and neck skin defect after total laryngectomy.To reconstruct the hypopharynx,upper esophagus,and neck skin defect,we used a supraclavicular artery island flap(SCAIF)for one-stage reconstruction.SCAIF offered reliable blood supply,minimal donor site morbidity,and excellent cosmetic outcomes.Although a small portion of the flap developed necrosis,it healed without surgical intervention.We also conducted a literature review of previously published articles on SCAIF for head and neck reconstruction.Our review highlights the advantages and limitations of SCAIF as a promising option for one-stage reconstruction of complex hypopharyngeal and upper esophageal defects with neck skin defects in selected patients.This case report provides valuable insights into the use of SCAIF in complex head and neck reconstructions,which can help improve patient outcomes and quality of life.

Nasolabial perforator flap for nasal defects

Nasal defects can be reconstructed with a nasolabial perforator flap,resulting in good aesthetic outcomes based on the facial subunit principle,owing to the combined advantages of the traditional nasolabial flap and the perforator flap.However,the localization of perforators makes the clinical application of a nasolabial perforator flap difficult.This review aims to provide a comprehensive summary of the nasolabial perforator flap from anatomical,methodological,and clinical application aspects,intending to provide plastic surgeons with a reference on conducting nasal reconstruction with a nasolabial perforator flap.

Diaphragmatic Flap: Technique of Preparation and Indications for Use

Background: The use of a vascularized pedicle flap of diaphragmatic muscle (DF) for reconstructive procedures in the chest has many advantages. Yet, despite the excellent reported results, the use of DF has not been widespread. Some factors for the less widespread use of DF have been, concern about diaphragmatic function, hesitation to use such a vital muscle for reconstructive purposes, and most importantly, the technical aspects for the preparation of the flap. Methods: Using a cadaveric model, the vascular anatomy of the diaphragm and the steps for the preparation of the DF was defined and illustrated for both the right and left hemidiaphragm. Results: No perioperative mortality with the use of DF has been recorded. Function of the native diaphragm has not been impaired. Bronchopleural fistulas and pericardial defects have healed in all instances. Excellent repair has been achieved in all patients with esophageal lesions. The disruption of the repaired native diaphragm and visceral herniation has been reported but it has been attributed to the learning curve and the technique of repair. Conclusion: With a better understanding of the vascular anatomy of the diaphragm and a formal methodical approach to harvesting the DF, more surgeons will be encouraged to use DF with excellent results.

Sensory reinnervation of free flaps in reconstruction of the breast and the upper and lower extremities

There is long-standing debate about sensate versus non-sensate free microvascular flaps among microsurgeons. The principle of connecting not only the vascular supply, but also sensitive nerves, in free tissue transfer is attractive. However, increased operating time and partial spontaneous innervation led to the common decision to restrict microsurgical tissue transfer to the vascular anastomosis and to leave the nerves ＂untreated＂. Nevertheless, in special cases such as breast reconstruction or extremity reconstruction, the question about sensory nerve coaptation of the flaps remains open. We present our experience with free microvascular tissue transfer for breast and extremity reconstruction and compare the data with previous literature and conclude that most free flap surgeries do not benefit from nerve coaptation.

Two-step strategy—conjunctival flap covering surgery combined with secondary deep anterior lamellar keratoplasty for the treatment of high-risk fungal keratitis

AIM:To investigate whether the two-step strategy[conjunctival flap covering surgery(CFCS)combined with secondary deep anterior lamellar keratoplasty(DALK)]is effective for patients with high-risk fungal keratitis(FK).METHODS:In this noncomparative,retrospective case series,10 subjects(6 males,4 females)with a mean age of 56.5±7.1(range 47-72)y with high-risk FK undergone the two-step strategy were included.Reported outcome measures were healing of the corneal ulcer,recurrence of FK,reject reaction,improvement in best corrected visual acuity(BCVA)and relevant complications.RESULTS:The average diameter of corneal infiltrates was 7.50±0.39 mm,ranging from 6.94 to 8.13 mm.The mean depth of corneal infiltrates was 422.4±77.1μm,ranging from 350 to 535μm.The mean corneal thickness was 597.4±117.3μm,ranging from 458 to 851μm.Hypopyon and endothelial plaques were presented in all patients.The period between the two steps was 3.65±0.9(ranging from 3 to 5)mo.The graft diameter was 7.75±0.39 mm.At the last follow-up(average 9.25±3.39,ranging from 5.5 to 17mo),no fungal recurrence or graft rejection appeared,and all patients showed improvement of BCVA.One patient suffered from liver function impairment due to oral voriconazole for 4wk and recovered spontaneously after 1wk of drug withdrawal.CONCLUSION:The two-step strategy is safe and effective in the treatment of high-risk FK by transforming intentional therapeutic penetrating keratoplasty during acute infection to later optical DALK.It is a practical strategy,especially in areas lacking fresh donor corneas and eye bank services.