Reconstruction of head and neck defects: a systematic approach to treatment

Establishing a Novel Treatment Algorithm for Pediatric Mandibular Tumor Reconstruction

INTRODUCTION

Guidelines for pediatric mandibular reconstruction (PMR) are not well-established. One must consider the growing craniofacial skeleton, mixed dentition, long-term dental occlusion, need for secondary reconstruction, and speech development. The traditional guideline (bone defect > 5 cm) for use of vascularized bone grafts (VBG) is not applicable given the variation of pediatric mandibular size and growth. We seek to propose a novel algorithm for PMR.

MATERIALS AND METHODS

An Institutional Review Board approved retrospective review of patients who underwent PMR for tumor resections between 2005 and 2019 evaluated patients' demographics, complications, resection index (RI) (resection length to mandibular length), and surgical outcomes. Outcomes based on RI were analyzed to establish guidelines for VBG utilization.

RESULTS

Twenty-four patients underwent PMR at a mean age of 9.1 years (range: 1-18). The mandibular defect (mean ± standard deviation) for non-VBG (n = 18) and VBG (n = 6) was 6.6 ± 3.0 cm and 12.8 ± 4.3 cm, respectively. The VBG group had fewer return trips to the operating room (P = 0.028) and fewer major complications (P = 0.028). When non-VBG with RI > 32% were compared to <32%, there was statistically less returns to the operating room for complications and a lower rate of early (<30 days) major complications.

DISCUSSION

Our algorithm proposes an RI cutoff of 32% for VBG use for PMR. Patients with a sizable soft tissue defect, previous chemotherapy and/or radiation, planned adjuvant chemotherapy and/or radiation therapy, or a history of failed non-VBG should undergo reconstruction using VBG.

Anatomic Subunit Approach to Composite Reconstruction of Facial Gunshot Wounds

ABSTRACT

With a rise in gun violence in the United States, surgeons are tasked with effectively managing penetrating facial trauma. The purpose of this study is to assess methods used for successful composite reconstruction of each anatomical facial subunit following penetrating trauma. A retrospective chart review was performed in subjects undergoing craniofacial reconstruction following penetrating trauma. Reconstructive methods were analyzed through operative reports. Subjects were categorized by anatomical subunit reconstructed (mandible, maxilla (malar complex and roof/palate), orbit, and cranium) and method of reconstruction (open reduction internal fixation only, bone graft, free flap, implant, and tissue expansion). Thirty-six subjects underwent reconstruction for penetrating facial trauma. Involved subunits include 24 mandible, 11 malar complex, 13 palate, 18 orbit, and 11 cranium. Predominate reconstruction method was open reduction internal fixation only for mandible (45.8%), bone grafting for malar complex (81.8%), implant for orbit (66.7%) and cranium (63.6%), and local tissue rearrangement for palate (84.6%). The predominate bone graft donor site was iliac for mandible (42.9%), rib for malar complex (36.3%) and orbit (40.0%), and frontal bone for cranium (42.8%). The predominate free flap was osteocutaneous for all mandible, orbit, and cranium and 7 of 10 (70.0%) palate reconstructions. Tissue expansion was used in all subunits except cranium. In conclusion, bone grafting, implants, free tissue transfer, and tissue expansion are all viable reconstruction options for penetrating trauma. There is no single approach to use, and decisions regarding definitive reconstruction method should be based upon anatomical subunit involved and the size/area of defects.

Degradable RGD-Functionalized 3D-Printed Scaffold Promotes Osteogenesis

To establish an ideal microenvironment for regenerating maxillofacial defects, recent research interests have concentrated on developing scaffolds with intricate configurations and manipulating the stiffness of extracellular matrix toward osteogenesis. Herein, we propose to infuse a degradable RGD-functionalized alginate matrix (RAM) with osteoid-like stiffness, as an artificial extracellular matrix, to a rigid 3D-printed hydroxyapatite scaffold for maxillofacial regeneration. The 3D-printed hydroxyapatite scaffold was produced by microextrusion technology and showed good dimensional stability with consistent microporous detail. RAM was crosslinked by calcium sulfate to manipulate the stiffness, and its degradation was accelerated by partial oxidation using sodium periodate. The results revealed that viability of bone marrow stem cells was significantly improved on the RAM and was promoted on the oxidized RAM. In addition, the migration and osteogenic differentiation of bone marrow stem cells were promoted on the RAM with osteoid-like stiffness, specifically on the oxidized RAM. The in vivo evidence revealed that nonoxidized RAM with osteoid-like stiffness upregulated osteogenic genes but prevented ingrowth of newly formed bone, leading to limited regeneration. Oxidized RAM with osteoid-like stiffness facilitated collagen synthesis, angiogenesis, and osteogenesis and induced robust bone formation, thereby significantly promoting maxillofacial regeneration. Overall, this study supported that in the stabilized microenvironment, oxidized RAM with osteoid-like stiffness offered requisite mechanical cues for osteogenesis and an appropriate degradation profile to facilitate bone formation. Combining the 3D-printed hydroxyapatite scaffold and oxidized RAM with osteoid-like stiffness may be an advantageous approach for maxillofacial regeneration.

Healing of a large avulsed mandibular bony segment: report of a unique case

This case report puts an emphasis on retaining and re-fixing any avulsed bony segments in the maxillofacial region and maintaining the periosteal layer whenever possible, especially in young patients. Adequate bony fixation and watertight soft tissue closure are vital components for bone healing. The healing potential of facial bones is much higher as compared to the long bones, due to the superior blood supply.

Outcomes following Microvascular Mandibular Reconstruction in Pediatric Patients and Young Adults

Background:

The etiology and treatment of complex mandibular defects in children differ markedly from those of adults, although treatment with free bone flaps is historical in both groups. While adult outcomes and complication rates are well known, few pediatric data exist, especially for patients with congenital deficiencies. This study reports early and late outcomes from a cohort of young, primarily syndromic patients undergoing microvascular mandibular reconstruction.

Methods:

This is a retrospective case series of patients who underwent microvascular mandibular reconstruction between 1995 and 2016.

Results:

Thirteen patients received a total of 13 fibula transfers and 1 medial femoral condyle transfer. Most patients carried a congenital diagnosis (77%), and the average age during surgery was 11.7 ± 5.7 years. The median (interquartile range) [IQR] length of follow-up was 6.3 (5.7) years. There was a 100% flap survival rate, although 86% of all patients experienced at least one complication. Half of all procedures resulted in an early complication. Nine patients (69%) developed late complications, of which temporal mandibular joint ankylosis was the most common (n = 5; 38%).

Conclusions:

This study is one of few detailing outcomes following mandibular reconstruction by free flap transfer in pediatric patients. These patients were primarily syndromic with appreciable complication rates higher than in other adult and pediatric studies. Some complications are manageable or self-resolving, but others lead to functional problems that may require late operative interventions to correct. Microsurgical treatment should be reserved for children with large, complex mandibular defects when other options are unavailable or have been exhausted.

Free Dermal Fat Autografting for Complex Craniofacial Wounds

Complex craniofacial wounds (CCW) are those refractory to initial treatment and may involve chronic infection, exposed hardware, irradiated tissue, and soft tissue volume loss. Typical reconstruction with microvascular flaps involves considerable morbidity. While free dermal fat autografting (DFA) is used extensively in many applications, its use treating CCW remains an unexplored but attractive possibility. Data from a retrospective cohort of 34 consecutive patients (13 male; 21 female and aged 2-79-years), who underwent free DFA between 1985 and 2018 for CCW by a single plastic surgeon, were analyzed. Post-operative follow-up was 1-24 years (M = 6.53, SD = 7.91). Many patients had several concomitant wound complications. Primary pre-operative wound complications were dominated by infection (N = 20), of which over 75% (N = 15) were associated with non-autogenic material. Eighteen had resolution of their pre-operative infection. Of the total (N = 34), 79.41% had stable grafts at follow-up [X(3) = 54, P < 0.001], with only 3 experiencing observable atrophy and 1 graft necrosis. Most of the cohort was complication free [X(1) = 7.53, P = 0.006], with 73.53% experiencing no problems involving the graft. Twenty-nine (85.29%) of 34 patients had therapeutic success with free DFA [X(1) = 28.65, P < 0.001]. Pre-operative wound status (β = 1.13, P < 0.001) predicted therapeutic success [R = 0.87, F(7,9) = 8.94, P = 0.002]. While 5 (14.71%) did not have therapeutic success, no additional problems arose related to grafts. Free DFA appears to be beneficial and show low morbidity. Future studies must evaluate these findings. In this context, their use should be considered in recalcitrant craniofacial wounds.

Bone regeneration of minipig mandibular defect by adipose derived mesenchymal stem cells seeded tri-calcium phosphate- poly(D,L-lactide-co-glycolide) scaffolds

Reconstruction of bone defects represents a serious issue for orthopaedic and maxillofacial surgeons, especially in extensive bone loss. Adipose-derived mesenchymal stem cells (ADSCs) with tri-calcium phosphates (TCP) are widely used for bone regeneration facilitating the formation of bone extracellular matrix to promote reparative osteogenesis. The present study assessed the potential of cell-scaffold constructs for the regeneration of extensive mandibular bone defects in a minipig model. Sixteen skeletally mature miniature pigs were divided into two groups: Control group and scaffolds seeded with osteogenic differentiated pADSCs (n = 8/group). TCP-PLGA scaffolds with or without cells were integrated in the mandibular critical size defects and fixed by titanium osteosynthesis plates. After 12 weeks, ADSCs seeded scaffolds (n = 7) demonstrated significantly higher bone volume (34.8% ± 4.80%) than scaffolds implanted without cells (n = 6, 22.4% ± 9.85%) in the micro-CT (p < 0.05). Moreover, an increased amount of osteocalcin deposition was found in the test group in comparison to the control group (27.98 ± 2.81% vs 17.10 ± 3.57%, p < 0.001). In conclusion, ADSCs seeding on ceramic/polymer scaffolds improves bone regeneration in large mandibular defects. However, further improvement with regard to the osteogenic capacity is necessary to transfer this concept into clinical use.

Reconstructing the Face of War

Introduction

Ongoing combat operations in Iraq, Afghanistan, and other theaters have led to an increase in high energy craniomaxillofacial (CMF) wounds. These challenging injuries are typically associated with complex tissue deficiencies, evolving areas of necrosis, and bony comminution with bone and ballistic fragment sequestrum. Restoring form and function in these combat-sustained CMF injuries is challenging, and frequently requires local and distant tissue transfers. War injuries are different than the isolated trauma seen in the civilian sector. Donor sites are limited on patients with blast injuries and they may have preferences or functional reasons for the decisions to choose flaps from the available donor sites.

Methods

A case series of patients who sustained severe combat-related CMF injury and were treated at Walter Reed National Military Medical Center (WRNMMC) is presented. Our study was exempt from Institutional Review Board review, and appropriate written consent was obtained from all patients included in the study for the use of representative clinical images.

Results

Four patients treated by the CMF team at Walter Reed National Military Medical Center are presented. In this study, we highlight their surgical management by the CMF team at WRNMMC, detail their postoperative course, and illustrate the outcomes achieved using representative patient clinical images. We also supplement this case series demonstrating military approaches to complex CMF injuries with CMF reconstructive algorithms utilized by the senior author (EDR) in the management of civilian complex avulsive injuries of the upper, mid, and lower face are thoroughly reviewed.

Conclusion

While the epidemiology and characteristics of military CMF injuries have been well described, their management remains poorly defined and creates an opportunity for reconstructive principles proven in the civilian sector to be applied in the care of severely wounded service members. The War on Terror marks the first time that microsurgery has been used extensively to reconstruct combat sustained wounds of the CMF region. Our manuscript reviews various options to reconstruct these devastating CMF injuries and emphasizes the need for steady communication between the civilian and military surgical communities to establish the best care for these complex patients.

Evaluation of Anatomic Variations of Fibula Free Flap in Human Fresh Cadavers

BACKGROUND

Reconstruction of the head and neck defects is still one of the most challenging surgeries for the surgeons. This study investigated on anatomic variations of fibula free flap in human fresh cadavers.

METHODS

Twenty fibula free flaps harvested from 10 fresh human corpses were enrolled. The number and type of skin perforators and their origin were recorded during the flap harvesting. After the completion of flap harvesting, the length of vascular pedicle and diameter of the artery and vein at the origin, the fibula length, the distance of the head of fibula to the site of peroneal artery bifurcation and harvesting time were also recorded.

RESULTS

The fibula free flaps were performed on 2 women and 8 men with the mean age of 35.6 years. The average number of perforators per flap was 1.7, most of which were musculocutaneous (35.29%) from soleus muscle. The mean fibula length was 33.1 (range: 31-35) cm. The mean distance of the head of fibula to the site of peroneal artery bifurcation from the tibialis posterior trunk was 5.76 (range: 4.5-6.5) cm. The mean length of the pedicle flap was 11.15 (range: 10-13) cm. The mean diameters of the peroneal artery and vein at the origin were 2.83 and 51.5 mm, respectively.

CONCLUSION

Although the fibula osteocutaneous flap is a reliable choice for maxillofacial reconstruction, flap harvesting is fairly difficult. Accordingly, surgeons must be aware of anatomical variations of the flap and have a suitable case selection to minimize the risk of surgical complications.

Gene Therapy for Bone Defects in Oral and Maxillofacial Surgery: A Systematic Review and Meta-Analysis of Animal Studies

Craniofacial bone defects are challenging problems for maxillofacial surgeons over the years. With the development of cell and molecular biology, gene therapy is a breaking new technology with the aim of regenerating tissues by acting as a delivery system for therapeutic genes in the craniofacial region rather than treating genetic disorders. A systematic review was conducted summarizing the articles reporting gene therapy in maxillofacial surgery to answer the question: Was gene therapy successfully applied to regenerate bone in the maxillofacial region? Electronic searching of online databases was performed in addition to hand searching of the references of included articles. No language or time restrictions were enforced. Meta-analysis was done to assess significant bone formation after delivery of gene material in the surgically induced maxillofacial defects. The search identified 2081 articles, of which 57 were included with 1726 animals. Bone morphogenetic proteins were commonly used proteins for gene therapy. Viral vectors were the universally used vectors. Sprague-Dawley rats were the frequently used animal model in experimental studies. The quality of the articles ranged from excellent to average. Meta-analysis results performed on 21 articles showed that defects favored bone formation by gene therapy. Funnel plot showed symmetry with the absence of publication bias. Gene therapy is on the top list of innovative strategies that developed in the last 10 years with the hope of developing a simple chair-side protocol in the near future, combining improvement of gene delivery as well as knowledge of the molecular basis of oral and maxillofacial structures.

Modified free latissimus dorsi musculocutaneous flap in the reconstruction of extensive postoncologic defects in the head and neck region

Oncological resection of advanced carcinoma in the head and neck region results in vast defects. The free latissimus dorsi musculocutaneous flap (FLDMF) is one of the most commonly used flaps for the repair of complex head and neck defects. We tried to modify FLDMF to multiple segments or combine it with acellular dermis to fit through-and-through defects in the oral-facial region during the last decade. A retrospective review of patients with FLDMF reconstruction between 2004 and 2012 was undertaken. Demographics, histology, surgical management, disease control and overall survival, complications, radiotherapy, aesthetic outcome, as well as economic results were analyzed. The majority of the patients (66.7%) had recurrent tumors, and the rest of the patients had primary tumor with stage IV. Fourteen patients (38.9%) had a history of prior radiation therapy, whereas 27.8% of the patients had postoperative radiation therapy. The areas of the defects vary from 52 cm to 180 cm (mean, 86.4 cm). The flap failed in 1 of the 37 patients. The complications at the recipient site include hematoma (n = 6, 16.7%), venous insufficiency (n = 4, 11.1%), infection (n = 3, 8.3), and partial flap necrosis (n = 2, 5.5%). The donor-site complications include delayed healing, necrosis of skin graft, and limited shoulder function. The 5-year overall survival rate was 39.1%, and the 5-year disease-free survival rate was 22.1%. In conclusion, the FLDMF could be modified to fit vast defects where voluminous tissue is needed to be transferred in the head and neck region.

Maxillary reconstruction: Current concepts and controversies

Maxillary reconstruction is still an evolving art when compared to the reconstruction of the mandible. The defects of maxilla apart from affecting the functions of the speech, swallowing and mastication also cause cosmetic disfigurement. Rehabilitation of the form and function in patients with maxillary defects is either by using an obturator prosthesis or by a surgical reconstruction. Literature is abundant with a variety of reconstructive methods. The classification systems are also varied, with no universal acceptance of any one of them. The oncologic safety of these procedures is still debated, and conclusive evidence in this regard has not emerged yet. Management of the orbit is also not yet addressed properly. Tissue engineering, that has been hyped to be one of the possible solutions for this vexing reconstructive problem, has not come out with reliable and reproducible results so far. This review article discusses the rationale and oncological safety of the reconstructing the maxillary defects, critically analyzes the classification systems, offers the different reconstructive methods and touches upon the controversies in this subject. The management of the retained and exenterated orbit associated with maxillectomy is reviewed. The surgical morbidity, complications and the recent advances in this field are also looked into. An algorithm, based on our experience, is presented.