Mimicking Clinical Rejection Patterns in a Rat Osteomyocutaneous Flap Model of Vascularized Composite Allotransplantation.

INTRODUCTION: Graft loss in vascularized composite allotransplantation (VCA) is more often associated with vasculopathy and chronic rejection (CR) than acute cellular rejection (ACR). We present a rat osteomyocutaneous flap model using titrated tacrolimus administration that mimics the graft rejection patterns in our clinical hand transplant program. Comparison of outcomes in these models support a role for ischemia reperfusion injury (IRI) and microvascular changes in CR of skin and large-vessel vasculopathy. The potential of the surgical models for investigating mechanisms of rejection and vasculopathy in VCA and treatment interventions is presented. MATERIALS AND METHODS: Four rodent groups were evaluated: syngeneic controls (Group 1), allogeneic transient immunosuppression (Group 2), allogeneic suboptimal immunosuppression (Group 3), and allogeneic standard immunosuppression (Group 4). Animals were monitored for ACR, vasculopathy, and CR of the skin. RESULTS: Transient immunosuppression resulted in severe ACR within 2 wk of tacrolimus discontinuation. Standard immunosuppression resulted in minimal rejection but subclinical microvascular changes, including capillary thrombosis and luminal narrowing in arterioles in the donor skin. Further reduction in tacrolimus dose led to femoral vasculopathy and CR of the skin. Surprisingly, femoral vasculopathy was also observed in the syngeneic control group. CONCLUSIONS: Titration of tacrolimus in the allogeneic VCA model resulted in presentations of rejection and vasculopathy similar to those in patients and suggests vasculopathy starts at the microvascular level. This adjustable experimental model will allow the study of variables and interventions, such as external trauma or complement blockade, that may initiate or mitigate vasculopathy and CR in VCA.

Pedicled osteomyocutaneous pectoralis major flap with osseous rib harvest for salvage mandibular reconstruction: Case and technique.

In the era of free flap reconstruction, mandibular defects are routinely reconstructed with osseous free flaps, and non-free flap bony reconstruction options are limited. A patient with T4N0 mandibular squamous cell carcinoma underwent resection with fibula free flap reconstruction of a parasymphyseal to angle defect. After free flap failure due to venous congestion, the flap was explanted. He declined additional free flap reconstruction and elected to proceed with pedicled osteomyocutaneous pectoralis major with rib. In this case presentation, we discuss the technical details of harvest of this flap using the 6th rib. The pedicled osteomyocutaneous pectoralis major flap with osseous rib harvest, which is infrequently described in the literature, remains a viable option for bony reconstruction, particularly in the salvage setting.

A Case Report of Post-traumatic Osteomyelitis with Gap Non-union of Humerus with Segmental Bone Defect and Scarred Skin Treated with Open Reduction Internal Fixation with Osteomyocutaneous Fibula.

INTRODUCTION: Non-union of closed humerus fractures is estimated to be about 5.5% and this figure is even higher in open fractures. In cases of non-union of the humerus with segmental bone defect, if a conventional treatment has failed, free fibular transfer is often considered for satisfactory bone union. In some cases, where there is severe scarring due to multiple previous surgeries. In such cases, skin cover may not be adequate and tight closures often lead to necrosis and failure excision. Segmental bone defects of the upper limb that is >6 cm with soft-tissue coverage defects have limited options for reconstruction. Osteomyocutaneous fibula may provide to be a valuable option in such cases. CASE REPORT: This is a report a case of a 27-year-old male presented with a history of road traffic accident with Gustilo-Anderson Grade 3 B open fracture of humerus midshaft. He developed humerus osteomyelitis, for which he underwent surgical debridement. He presented to us with gap non-union with segmental bone loss. The overlying skin was scarred and had significant limb shortening. Treatment options for such a case are reconstruction or amputation. Challenges for reconstruction were to deal with the segmental bone loss and the soft-tissue defect following scar excision. We tackled both these challenges with an osteomyocutaneous fibula flap. At 1-year follow-up, the humerus showed union and flap uptake was good. CONCLUSION: Osteomyocutaneous fibula flap is a valuable treatment options in such complicated cases allowing for both bone union and soft-tissue coverage with a single surgical procedure.

A Novel and Simple Technique of Reconstructing the Central Arch Mandibular Defects-a Solution During the Resource-Constrained Setting of COVID Crisis.

The current COVID 19 pandemic has a major impact on healthcare delivery globally. Oral cancer involving anterior arch of mandible is difficult to reconstruct and ideally, requires free fibular osteomyocutaneous flap. During this time of resource constraint situation, these free flaps are not a great choice, as it increases exposure of both patient and surgical team to the deadly virus. We are describing a novel method of reconstruction after resection of oral cancer involving anterior arch of mandible. In this new technique, we have reconstructed central arch defect by hanging bipaddle pectoralis major myocutaneous flap with orbicularis oris muscle using ethylene terephthalate suture. Operative time, early postoperative complications and early cosmetic and functional outcome were assessed. We have used this novel technique in eight patients of T4a oral cancer involving anterior arch of mandible and skin over chin. Mean operative time was 180 min. One patient had minor flap loss with surgical site infection (Clavien-Dindo grade I). In all patients, we were able to discharge all patients on eighth postoperative day. Cosmetic outcome and functional outcomes were mostly satisfactory. All patients were able to oppose their lips without any oral incompetence and drooling. Tongue mobility was good. There was no incidence of 'Andy Gump deformity'. This is a feasible option for reconstructing anterior arch defect in resource- and time-limited setting of COVID 19 pandemic. This technique can also be used in comorbid conditions where it is not advisable to do very long surgery.

Delayed Reconstruction of Palatomaxillary Defect Using Fibula Free Flap.

INTRODUCTION: The objective of this study was to evaluate a surgical technique and to present the results of delayed reconstruction of palatomaxillary defects using fibula free flap (FFF). METHODS: A review was conducted for nine patients who underwent palatomaxillary reconstruction using FFF. Primary disease, type of reconstruction, defect area, fibula segment length and number of osteotomies, radiotherapy, and implant installation after FFF reconstruction were analyzed. RESULTS: All nine patients underwent delayed reconstruction. The fibula shaft was osteotomized into two segments in seven patients and three segments in one patient with bilateral Brown's revised classification IV/d defect. One case was planned by using a computer-aided design computer-aided manufacturing (CAD/CAM) system with a navigation system. The mean length of the grafted fibula bone was 68.06 mm. Dental implant treatment was performed in six patients. Six patients received radiation therapy, and there were no specific complications related to the radiation therapy. In one case, the defect was reconstructed with FFF flow-through from a radial forearm free flap. CONCLUSION: This clinical study demonstrated that the fibula flap is an ideal donor-free flap in a palatomaxillary defect. Delayed reconstruction using an FFF can reduce the complication and failure rates.

Jaw reconstruction with vascularized fibular flap: The 11-year experience among 104 patients.

BACKGROUND: A vascularized fibular osteomyocutaneous flap with severe vascular crisis often results in serious consequences. This study aims to examine the clinical effect of non-vascularized fibular graft on patients with severe vascular crisis after reconstruction of the defect jaw with vascularized fibular osteomyocutaneous flap. MATERIALS AND METHODS: From December 2007 to December 2018, a total of 104 patients with jaw neoplasms that underwent reconstruction with free vascularized fibular flap were retrospectively analyzed; seven of these cases had postoperative vascular crisis during mandibular reconstruction. RESULTS: Of the seven cases with postoperative vascular crisis, the vascularized fibular flaps in three patients survived completely, thanks to early detection; two cases were completely necrotic and removed in the end, and the remaining two cases had severe vascular crisis after the removal of the soft tissue attached to the fibular flap. The non-vascular fibular grafts were retained regardless of the severe absorption after follow-ups for 25 and 69 months, respectively. CONCLUSIONS: If vascular crisis occurs following jaw reconstruction with a vascularized fibular osteomyocutaneous flap, early re-surgical exploration effectively improves the salvage rate. In addition, when a severe vascular crisis occurs, the vascularized fibular flap can be changed to a non-vascular fibular graft to reconstruct the mandibular defect, thus avoiding the serious consequences resulting from the complete failure of fibular graft.

Common Rodent Flap Models in Experimental Surgery.

BACKGROUND: Flap procedures are widely used in clinical reconstructive surgery. Since ische-mia-associated complications, e.g., wound breakdown or tissue necrosis, are still a great challenge in flap surgery, experimental flap models are widely used to study flap physiology and to evaluate treatment strategies to prevent these complications. SUMMARY: Since rodents in general, and mice and rats in particular, are widely used in experimental flap models, we give an overview of the most common flap models in rodents, including the cremaster flap, the osteomyocutaneous flap, the McFarlane flap, the ear flap, and the dorsal skinfold chamber. Key Messages: Rodent flap models in experimental surgery are manifold and have a long history. These models play an important role in training surgical techniques, understanding flap physiology, defining flap anatomy and vascularity, and developing treatment regimens to prevent the necrosis of ischemically challenged tissue. However, it is important to be aware of the advantages and disadvantages of the single flap models concerning the possible time span of the experiment, the degree of difficulty, and the reproducibility and the translation of the results in humans.

[Virtual surgical planning and intraoperative navigation for mandibular reconstruction: from accurate to minimal invasive].

Simultaneous restoration of function and appearance should be performed in mandibular reconstruction. Option of reconstructive techniques is determined by cause, location, extent, and classification of the mandibular defects. Vascularize bone graft is one of the most popular technique in current clinical practice of mandibular reconstruction. Fibula is the most common donor site for mandibular reconstruction. The disadvantage of low height of neo-mandible reconstructed by single fibular segment can be solved by vascularized double barrel fibula graft. Using virtual surgical planning and intraoperative navigation for mandibular reconstruction leads to simplify surgical procedure, reduce operating time and injury, and decrease donor site morbidity so that accurate mandibular reconstruction could be completed. Direction of minimal invasive surgery for mandibular reconstruction will be developed by intraoral approach and intraoral anastomosis.

Single stage reconstruction of post traumatic and post excisional composite perigenual defects using chimeric pedicled propelled osteomyocutaneous fibula flap.

INTRODUCTION: Composite perigenual defects (CPGDs) are exacting the expertise of the reconstructive surgeons. Segmental skeletal defects continue to be a challenge for both orthopedic and plastic surgeons. There are many techniques available for the reconstruction of segmental skeletal defects in the perigenual region. This study explores the outcomes of pedicled chimeric propelled osteomyocutaneous fibula flap reconstruction of post traumatic and post excisional composite perigenual defects (CPGDs) MATERIALS AND METHODS: It was a retrospective study conducted from 2011 to 2016 including 16 patients (5 post excisional defects and 11 post traumatic defects). 14 males and 2 females were included. Ages of the patients were ranging from 24 to 46 years. All had their CPGDs reconstructed with chimeric pedicled propelled fibula osteomyocutaneous flap RESULTS: All 15 patients on an average of 26 months follow-up assumed pain free unrestrictive walking. Fracture of hardware and transferred fibula occurred in one case 2 1/2 years following the surgery. Other patients had good functional recovery in an average of 26 months follow up. The average MSTS score of 15 patients was 23.9. CONCLUSION: This anatomically construed procedure will be addendum to the armamentarium of reconstruction in both post excisional limb salvage milieu and secondary posttraumatic context for the perigenual composite defects. With high healing potential, infection culling capacity, high osteogenic potential and good supportive hardwares the pedicled osteomyocutaneous fibula flap may usher in better outcome in composite perigenual defects reconstruction.

An Innovative Application of the Free Vascularized Medial Femoral Condyle Flap in the Prevention of Recurring Neuropathic Ulcer in the Diabetic Foot: A Case Report.

Despite various therapy options, the prophylactic and symptomatic treatment of recurrent ulcerations in the diabetic foot are still challenging. We report the application of a free vascularized medial femoral condyle flap to prevent the recurrence of pressure ulcer in a patient with diabetic foot syndrome. Our patient had type 2 diabetes and presented with pressure ulcers and osteomyelitis of metatarsal heads 2 and 3 after a great toe amputation. We chose to use a medial femoral condyle flap as a damper in the area of the metatarsal heads because of the relatively young age and good vascularity of our patient. We shaped the graft like a ski to distribute the pressure and prevent perforation of the plantar skin. Good results were achieved for wound healing, pain reduction, and improvement of gait. No pressure ulceration had recurred after a 3-year follow-up period. The versatility of the osteomyocutaneous graft from the medial femoral condyle is an important reconstructive tool for addressing major surgical problems. We present the first use of a medial femoral condyle flap in the treatment of a pressure ulcer in a diabetic foot. In selected patients, our method could prevent premature and extended amputations, thereby providing good improvement in patients' quality of life.

Virtual surgical planning and intraoperative navigation for mandibular reconstruction: from accurate to minimal invasive / 中国修复重建外科杂志

Simultaneous restoration of function and appearance should be performed in mandibular reconstruction. Option of reconstructive techniques is determined by cause, location, extent, and classification of the mandibular defects. Vascularize bone graft is one of the most popular technique in current clinical practice of mandibular reconstruction. Fibula is the most common donor site for mandibular reconstruction. The disadvantage of low height of neo-mandible reconstructed by single fibular segment can be solved by vascularized double barrel fibula graft. Using virtual surgical planning and intraoperative navigation for mandibular reconstruction leads to simplify surgical procedure, reduce operating time and injury, and decrease donor site morbidity so that accurate mandibular reconstruction could be completed. Direction of minimal invasive surgery for mandibular reconstruction will be developed by intraoral approach and intraoral anastomosis.

Using virtual surgical planning for resection of jaw tumor and accurate reconstruction / 口腔疾病防治

Objective @#To review the patients who underwent accurate maxillary and mandibular reconstruction with vascularized osteomyocutaneous flap using virtual surgery and evaluate the postoperative results.@*Methods@# From June of 2009 to December of 2014, ninety-four patients were treated in our department. In virtual surgical planning, maxillectomy and mandibulectomy were simulated and donor site bone was superimposed mirror image of normal maxilla and mandible to complete accurate maxillary and mandibular reconstruction. Maxillectomy, mandibulectomy and bone reconstruction were performed using stereomodels and guided templates to replicate the virtual planning. Actual reconstruction result was compared with that of virtual surgery. The patients were asked to assess their satisfaction with facial appearance at 1 year postoperatively. @*Results@#Good bony unions and occlusion were observed in 94 patients. The actual results were basically in accordance with that of virtual surgery. The actual deviation between postoperative CT and preoperative virtual surgical planning was no more than 1 mm matched by computer software. All patients reported their facial appearance were excellent or good at 1 year postoperatively.@*Conclusion@#The ideal contour of neomaxilla and neomandible and good function with dental rehabilitation can be gained after accurate maxillary and mandibular reconstruction with vascularized osteomyocutaneous flap using virtual surgery.

Acceptable clinical outcomes and recommended reconstructive strategies for secondary maxillary reconstruction with vascularized fibula osteomyocutaneous flap: A retrospective analysis.

BACKGROUND: We conducted a retrospective analysis of the clinical outcomes and evaluated the reconstructive strategies in patients who underwent secondary maxillary reconstruction with a vascularized fibula osteomyocutaneous flap (VFOF). METHODS: From May of 2001 to June of 2014, 34 patients who underwent secondary maxillary reconstruction with VFOF, with or without titanium mesh, were reviewed. The patients were divided into two groups of maxillary reconstruction, according to different planning and treatment strategies. In Group 1, presurgical planning was achieved using three-dimensional stereomodeling (n = 12). In Group 2, virtual surgical planning was performed and guided templates were produced (n = 22). The differences in the preoperative planning, intraoperative technique, postoperative complications, and long-term results between the two groups were analyzed. Statistical analysis was performed to determine the differences between the two groups and the risk factors for prognosis. RESULTS: Similar and accurate secondary maxillary reconstructions were successfully performed in Group 1 and 2. Postoperative complications were reported in 8 patients in Group 1 and 11 patients in Group 2. Complications were reported in patients who underwent radiotherapy. The incidence of postoperative complications in Group 2 were lower than that in Group 1 with the exception of midfacial collapse (P > 0.05). The long-term results of some patients with class 3 defects were not satisfactory because of midfacial collapse and lower eyelid ectropion. Stepwise regression analysis showed radiotherapy to be a risk factor for prognosis. CONCLUSIONS: The long-term results of secondary maxillary reconstruction were reported to be acceptable in our study. Radiotherapy was the risk factor for prognosis in secondary maxillary reconstruction. On the basis of these results, we highly recommend our strategy for secondary maxillary reconstruction. Good functional results could be achieved after the accurate restoration of maxillary alveolar ridge with several fibular segments using virtual surgical planning and dental restoration.

Intraoral lining with the fibular osteomyofascial flap without a skin paddle during maxillary and mandibular reconstruction.

BACKGROUND: To achieve an ideal intraoral lining, we harvest the fibular osteomyofascial flap to avoid the common embarrassment caused by the fibular osteomyocutaneous flap, and we report on our experience with this technique in this article. METHODS: Twenty-eight patients underwent reconstruction of the maxilla and mandible using an osteomyofascial free fibula flap after oncologic ablation. Data, including the size of the fascial flaps, the number of debulking operations, the complications at both the donor and recipient sites, and the dental rehabilitation, were collected. RESULTS: All fascial flaps survived and were remucosalized, except one with partial necrosis. None of the patients in the osteomyofascial group required an additional debulking operation, and 82% of the patients (23 of 28) had conventional dentures and showed good chewing function and cosmetic results. CONCLUSION: The fibular osteomyofascial flap yielded a more anatomic solution for oral mucosal defects, obviating the need for additional debulking and potentially reducing donor-site wound problems. © 2015 Wiley Periodicals, Inc. Head Neck 38: E832-E836, 2016.

Reconstruction of mandible defect in osteoradionecrosis patients with free fibula osteomyocutaneous flap / 中华显微外科杂志

Objective To explore the clinical applicating and efficacy of free fibula osteomyocutane- ous flap in mandible defect reconstruction in osteoradionecrosis patients.Methods The mandible defects were reconstructed by free fibula flaps with or without muscle cuff.The soft tissue defects were repaired by skin paddles.Status of osteotomy in fibula and flap survival was recorded.The complication in recipient site and donor site,as well as mouth opening and occlusion were reviewed.Facial contour and chewing function after reconstruction were evaluated.Results Patients were followed up 3-16 months.4 free fibula flaps with muscle cuff and 5 without muscle cuff survived well.The size of mandible defects covered from 6cm to 17cm. And the harvested fibula flaps with length of 8.6-17cm were cut into 3 segments in 2 cases,and 2 segments in 5 cases.Fibula flap was divided into 2 segments and overlapped in 2 cases.No serious complication was oh- served in recipient site and donor site.Satisfying esthetic result and normal occlusiong of heath mandible were obtained in all cases.The degree of mouth opening was 2.5-3.3cm.Fair chewing function was revealed in re- constructive region after prosthesia repaired.Conclusion Free fibula osteomyocutaneous flap is relatively ideal reconstruction material of mandible defect in osteoradionecrosis patients for its high survival rate and well esthetic results.

Pectoralis major rib osteomyo cutaneous flap in primary mandibular reconstruction in floor of the mouth cancer.

We report pectoralis major rib osteo myocutaneous flap in reconstruction of cancer floor of the mouth in 8 cases. We have discussed it's advantages in country like ours over the micro vascular graft. The rib (Vascularised bone graft) incorporated in this flap gives ideal support for mandibular arch reconstruction.