Numerical investigation on aerodynamic performance of a bionic flapping wing

This paper numerically studies the aerodynamic performance of a bird-like bionic flapping wing.The geometry and kinematics are designed based on a seagull wing,in which flapping,folding,swaying,and twisting are considered.An in-house unsteady flow solver based on hybrid moving grids.is adopted for unsteady flow simulations.We focus on two main issues in this study,i.e.,the influence of the proportion of down-stroke and the effect of span-wise twisting.Numerical results show that the proportion of downstroke is closely related to the efficiency of the flapping process.The preferable proportion is about 0.7 by using the present geometry and kinematic model,which is very close to the observed data.Another finding is that the drag and the power consumption can be greatly reduced by the proper span-wise twisting.Two cases with different reduced frequencies are simulated and compared with each other.The numerical results show that the power consumption reduces by more than 20%,and the drag coefficient reduces by more than 60% through a proper twisting motion for both cases.The flow mechanism is mainly due to controlling of unsteady flow separation by adjusting the local effective angle of attack.These conclusions will be helpful for the high-performance micro air vehicle (MAV) design.

Swallowing Function before and after Subtotal Glossectomy and Reconstruction with a Rectus Abdominis Musculocutaneous Flap: A Case Report

Purpose: Swallowing function was in a patient with tongue cancer that was evaluated with video fluorography before and after subtotal glossectomy and reconstruction with a rectus abdominis muscuocutaneous flap. Materials and Methods: A 41-year-old man underwent subtotal glossectomy and retained the unilateral posterior mylohyoid and unilateral stylohyoid muscles. The structure of the flap was evaluated postoperatively. To assess swallowing function, video fluorography was performed before surgery, 1 month after surgery and 1 year after surgery. Testing involved 1) ability to hold 10 mL of liquid in the oral cavity, 2) epiglottis turnover, 3) the presence of aspiration, 4) hyoid bone movement, and 5) maximum width of the esophageal entrance. Results: The flap was protuberant postoperatively. The patient was able to hold the test diet in the oral cavity before and after surgery. Epiglottis turnover was good before surgery but insufficient after surgery. Aspiration during swallowing was not observed before or after surgery. At rest, the hyoid bone sagged postoperatively, in comparison with preoperatively. Hyoid bone movement and width of the esophageal entrance decreased after surgery;however, they demonstrated gradual recovery. Conclusions: For good postoperative swallowing function after subtotal glossectomy, it is necessary to perform reconstruction with protuberant flap and to retain the suprahyoid muscles as much as possible.

Role of Reversed Sural Artery Flap in Reconstruction of Lower Third of the Leg, Ankle and Foot Defects

Introduction: Coverage of defects of the distal lower extremity and foot remains a challenging reconstructive prcedure. Free tissue transfer remains the standard for the management of these defects. However, there are some disadvantages like;longer operative times, bulky contour, and the need for highly skilled expertise. The reverse superficial sural artery flap (RSSAF) is a distally based fasciocutaneous or adipo-fascial flap that is used for coverage of defects that involve the distal third of the leg, ankle, and foot. A significant advantage of this flap is a constant blood supply that does not require sacrifice of a major artery. Methods: Twenty RSSAF flaps were harvested for reconstruction of different traumatic soft tissue defects of the lower third of leg, ankle and foot. Follow up for 6 months postoperative. Results: Twenty Patients;twelve males and eight females underwent reconstruction of different soft tissue defects over the foot and ankle using RSSAF. The overall complications occurred in 6 flaps;4 minor and 2 major complications. The remaining 14 flaps passed an uneventful follow up. Conclusions: The reverse superficial sural artery flap RSSAF can be used as a reliable alternative to free tissue transfer in reconstruction of defects over the lower third of leg, ankle, and foot. Venous congestion is the major threat to the flap but its incidence can be minimized by wide pedicle, less kink of the flap, and keep the venae comitants around the artery.

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.

Sternal Reconstruction of Deep Sternal Wound Infections Following Median Sternotomy by Single-stage Muscle Flaps Transposition

Objective To assess clinical effectiveness of using bilateral pectoralis major or plus rectus abdominis muscle flaps in treating deep sternal wound infection(DSWI) following median sternotomy. Methods Between January 2009 and December 2013, 19 patients with DSWI after median sternotomy for cardiac surgery were admitted to our hospital, including 14 males(73.7%) and 5 females(26.3%), aged 55±13(18-78) years. According to the Pairolero classification of infected median sternotomies, 3(15.8%) patients were type II, and the other 16(84.2%) were type III. Surgical procedure consisted of adequate debridement of infected sternum, costal cartilage, granulation, steel wires, suture residues and other foreign substances. Sternal reconstruction used the bilateral pectoralis major or plus rectus abdominis muscle flaps to obliterate dead space. The drainage tubes were placed and connected to a negative pressure generator for adequate drainage. Results There were no intraoperative deaths. In 15 patients(78.9%), bilateral pectoral muscle flaps were mobilized sufficiently to cover and stabilize the defect created by wound debridement. 4 patients(21.0%) needed bilateral pectoral muscle flaps plus rectus abdominis muscle flaps because their pectoralis major muscle flaps could not reach the lowest portion of the wound. 2 patients(10.5%) presented with subcutaneous infection, and 3 patients(15.8%) had hematoma. They recovered following local debridement and medication. 17 patients(89.5%) were examined at follow-up 12 months later, all healed and having stable sternum. No patients showed infection recurrence during the follow-up period over 12 months. Conclusion DSWI following median sternotomy may be effectively managed with adequate debridement of infected tissues and reconstruction with bilateral pectoralis major muscle or plus rectus abdominis muscle flap transposition.

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.

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.

Hypothenar fat pad flap vs conventional open release in primary carpal tunnel syndrome:A randomized controlled trial

AIM To compared outcomes between the hypothenar fat pad flap(HTFPF) and conventional open carpal tunnel release(COR) in primary carpal tunnel syndrome(CTS). METHODS Forty-five patients(49 hands) were enrolled into the study from January 2014 to March 2016, 8 patients were excluded. Randomization was conducted in 37 patients(41 hands) by computer generated(Block of four randomization) into COR and HTFPF group. Nerve conduction study(NCS) included distal sensory latency(DSL), distal motor latency(DML), sensory amplitude (S-amp), motor amplitude(M-amp) and sensory nerve conduction velocity(SCV) were examined at 6 and 12 wk after CTR. Levine score, grip and pinch strength, pain [visual analog scale(VAS)], 2-point discrimination(2-PD), Semmes-Weinstein monofilament test(SWM), Phalen test and Tinel's sign were evaluated in order to compare treatment outcomes.RESULTS The COR group, 19 patients(20 hands) mean age 50.4 years. The HTFPF group, 20 patients(21 hands) mean age 53.3 years. Finally 33 patients(36 hands) were analysed, 5 patients were loss follow-up, 17 hands in COR and 19 hands in HTFPF group. NCS revealed significant difference of DSL in HTFPF group at 6 wk(P < 0.05) compared with the COR group. S-amp was significant improved postoperatively in both groups(P < 0.05) but not significant difference between two groups. No significant difference of DML, M-amp and SCV postoperatively in both groups and between two groups. Levine score, pain(VAS), grip and pinch strength, 2-PD, SWM, Phalen test and Tinel's sign were improved postoperatively in both groups, but there was no significant difference between two groups.CONCLUSION There is no advantage outcome in primary CTS for having additional HTFPF procedure in CTR. COR is still the standard treatment. Nevertheless, improvement of DSL and S-amp could be observed at 6 wk postoperatively.

Anatomy of Free Flap Failures: Dissection of a Series

Introduction: Free flap success rates have remained stable in recent years ranging 93% to 98%. Historically, the causes of free flap failures were attributed to the surgeon’s inexperience and technique. However, there are factors beyond the surgical anastomosis that contribute to flap failure. The purpose of this study is to review each case of total flap loss in detail to develop a better understanding of complications. Methods: A retrospective study was performed over eleven years in a single surgeon’s practice, a predominantly head and neck reconstructive practice. All charts were independently reviewed. In patients who sustained total flap loss, a review was conducted of patient comorbidites, anesthesia records, perioperative and follow-up notes. Results: A total of 514 free flaps were performed. 76% (392) of these flaps were for head and neck reconstruction. There were 22 total flap losses (4%) and 26 partial flap losses (5%). Of the 22 total flap losses, four flaps were avulsed, five flaps were in patients later found to have coagulation disorders (homozygous mutations of the MTHFR gene and factor V Leiden), four patients were exposed to neosynephrine, two patients remained hypotensive perioperatively, and four delayed flap losses were attributed to pseudomonal infection. Five losses were technical or related to flap inexperience. Several representative case scenarios are illustrated. Conclusion: Careful review of free flap failures indicates that a thorough workup (particularly coagulation disorders), flap selection, surgeon to anesthesia communication, proper securing of the flap, and postoperative patient blood pressure and infection control have a greater part to play in this new era of anastomotic success.

Role of adipose-derived stromal cells in pedicle skin flap survival in experimental animal models

The use of skin flaps in reconstructive surgery is the first-line surgical treatment for the reconstruction of skin defects and is essentially considered the starting point of plastic surgery. Despite their excellent usability, their application includes general surgical risks or possible complications, the primary and most common is necrosis of the flap. To improve flap survival, researchers have used different methods, including the use of adiposederived stem cells, with significant positive results. In our research we will report the use of adipose-derived stem cells in pedicle skin flap survival based on current literature on various experimental models in animals.

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.

Optimization of Bottom-hinged Flap-type Wave Energy Converter for a Specific Wave Rose

In this paper, we conducted a numerical analysis on the bottom-hinged flap-type Wave Energy Convertor (WEC). The basic model, implemented through the study using ANSYS-AQWA, has been validated by a three-dimensional physical model of a pitching vertical cylinder. Then, a systematic parametric assessment has been performed on stiffness, damping, and WEC direction against an incoming wave rose, resulting in an optimized flap-type WEC for a specific spot in the Persian Gulf. Here, stiffness is tuned to have a near-resonance condition considering the wave rose, while damping is modified to capture the highest energy for each device direction. Moreover, such sets of specifications have been checked at different directions to present the best combination of stiffness, damping, and device heading. It has been shown that for a real condition, including different wave heights, periods, and directions, it is very important to implement the methodology introduced here to guarantee device performance.

Distally based perforator sural flaps for foot and ankle reconstruction

Distally based perforator sural flaps from the posterolateral or posteromedial lower leg aspect are initially a neurofasciocutaneous flap that can be transferred reversely to the foot and ankle region with no need to harvest and sacrifice the deep major artery. These flaps are supplied by a perforating artery issued from the deep peroneal artery or the posterior tibial artery, and the chainlinked adipofascial neurovascular axis around the sural/saphenous nerve. It is a versatile and reliable technique for soft-tissue reconstruction of the heel and ankle region with 180-degrees rotation. In this paper, we present its developing history, vascular basis, surgical techniques including flap design and elevation, flap variations in pedicle and component, surgical indications, and illustrative case reports with different perforating vessels as pivot points for foot and ankle coverage.

The Pectoralis Major Myocutaneous Pedicled Flap Revisited

The pectoralis major myocutaneous pedicle flap (PMMF) is still being used by many surgeons and plays an important role in head and neck reconstruction. The purpose of this series was to review our 10 years’ experience with the PMMF in head and neck reconstruction. One hundred and two patients who underwent the PMMF technique were reviewed on the clinical records. Postoperative complications were classified into flap loss, hemorrhage, infection, fistula formation, wound dehiscence and donor site complication. Eighty two patients (80.4%) demonstrated no complication. Six patients among 102 patients (5.9%) demonstrated total or partial skin necroses. Three female patients were completely dissatisfied with the cosmetic appearance after the PMMF. One of them required a reconstructive surgery with the latissimusdorsi flap. Without surgical expertise in plastic surgical field, an ear-nose-throat or an oral surgeon can performed the PMMF technique provided the operator is well aware of serious and frequent complications of this “workhorse” procedure.

Supermicrosurgery in fingertip defects-split tibial flap of the second toe to reconstruct multiple fingertip defects: A case report

BACKGROUND Injuries to multiple fingertips pose a significant treatment dilemma.Numerous reconstructive options exist,all with the ultimate goal of restoring function and sensibility to the injured fingertips.CASE SUMMARY A 24-year-old male suffered injury to multiple fingertips of the right hand,resulting in exposed distal phalanges of the middle,ring,and small fingers.The amputated distal stumps were not possible for replantation.Free flap coverage was selected in order to achieve better functional outcome.The fingertip defects were covered by performing a right second toe split tibial flap using local anesthesia at the harvest site and brachial plexus nerve block for the right upper extremity.At 6-month follow-up,all three of the reconstructed fingertips had some preserved nail growth,Semmes-Weinstein Monofilaments testing was equal to the contralateral side and the Static Two-Point Discrimination were comparable to the contralateral side.CONCLUSION This report provides a novel reconstructive option for the management of multiple fingertip injuries and demonstrates the utility of supermicrosurgery in management of these injuries.

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.

Recurrent cervical esophageal stenosis after colon conduit failure:Use of myocutaneous flap

A 53-year-old male developed cervical esophageal stenosis after esophageal bypass surgery using a right colon conduit.The esophageal bypass surgery was performed to treat multiple esophageal strictures resulting from corrosive ingestion three years prior to presentation.Although the patient underwent several endoscopic stricture dilatations after surgery,he continued to suffer from recurrent esophageal stenosis.We planned cervical patch esophagoplasty with a pedicled skin flap of sternocleidomastoid(SCM) muscle.Postoperative recovery was successful,and the patient could eat a solid meal without difficulty and has been well for 18 mo.SCM flap esophagoplasty is an easier and safer method of managing complicated and recurrent cervical esophageal strictures than other operations.

Hybrid Procedure Utilizing Stent Grafts to Stabilize Distal Flaps after Common and Superficial Femoral Endarterectomy

Background: Endarterectomy has long been the standard for common femoral artery (CFA) occlusive disease. Hybrid procedures utilizing endovascular and open techniques have recently been used for revascularization. The purpose of this study was to evaluate the effectiveness of the use of a stent graft to stabilize the distal flap and prevent further dissection after extensive endarterectomy. Methods: All patients from Monmouth Medical Center in Long Branch, NJ from September 2008 to March 2013 who underwent an extensive common and superficial femoral (SFA) endarterectomy combined with the use of a Viabahn (Gore Medical) stent graft to stabilize the distal flap were included in the study. These stents were deployed in the proximal SFA after extensive endarterectomy, under direct visualization, without the aid of fluoroscopy. Due to the location in the SFA, these flaps were not amenable to suture tacking. Results: Fifteen patients met these criteria and were included in our study. Twelve patients underwent femoral endarterectomy for severe claudication and three patients for limb salvage. Technical success was achieved in all 15 patients. Five patients also had stents placed proximally to increase inflow and one patient had an additional stent placed distally to improve outflow. There were no intraoperative or postoperative complications. Conclusion: Stent graft placement allows a more extensive endarterectomy to be performed by stabilizing the distal flap allowing a safe transition into the true lumen that is not possible with suture tacking.

Male papillary breast cancer treated by wide resection and latissimus dorsi flap reconstruction: A case report and review of the literature

Breast cancer(BC) in men represents between 0.5% and 1% of all BC diagnosed each year. We report a case of advanced BC in a 62-year-old male treated at our interdisciplinary Breast Cancer Center. The patient presented with a newly diagnosed large, symptomatic mass in his left breast. Clinical examination showed a not movable mass of 16 cm diameter, deforming the whole breast; the overlying skin was livid and hypervascularized. Enlarged lymph nodes were palpable in the axillary pit. He had no concomitant diseases at time of presentation. He denied any first- or second degree family medical history of cancer of any type and he never received radiotherapy. Ultrasound guided minimal-invasive 14-gauge core biopsy revealed a moderately differentiated encapsulated papillary carcinoma with high expression of estrogen and progesterone receptors(both > 80%, IRS 12) and HER2-negative. Because of the tumor size a mastectomy with axillary dissection and chest wall reconstruction using a latissimus dorsi flap was performed. Histological analysis showed invasive growth besides typical(non-invasive) papillary carcinoma and was classified as invasive solid papillary carcinoma; p T3(10 cm), p N0(0/15), M0,R0; Oncotype DX Recurrence Score indicated low risk(RS: 2). After discussion in the interdisciplinary tumor board meeting, radiation therapy and tamoxifen were recommended. The patient had an uneventful recovery and is disease-free after two years of follow-up. Male BC is typically diagnosed at an advanced stage, most likely due to a lack of awareness that men can develop BC. Therefore, in case of a large tumor, a flap-based thoracic reconstruction may be required.