High-Density Porous Polyethylene Implant Cranioplasty: A Systematic Review of Outcomes.

Porous polyethylene has been widely used in craniofacial reconstruction due to its biomechanical properties and ease of handling. The objective of this study was to perform a systematic review of the literature to summarize outcomes utilizing high-density porous polyethylene (HDPP) implants in cranioplasty. A literature search of PubMed, Cochrane Library, and Scopus databases was conducted to identify original studies with HDPP cranioplasty from inception to March 2023. Non-English articles, commentaries, absent indications or outcomes, and nonclinical studies were excluded. Data on patient demographics, indications, defect size and location, outcomes, and patient satisfaction were extracted. Summary statistics were calculated using weighted averages based on the available reported data. A total of 1089 patients involving 1104 cranioplasty procedures with HDPP were identified. Patients' mean age was 44.0 years (range 2 to 83 y). The mean follow-up duration was 32.0 months (range 2 wk to 8 y). Two studies comprising 17 patients (1.6%) included only pediatric patients. Alloplastic cranioplasty was required after treatment of cerebrovascular diseases (50.9%), tumor excision (32.0%), trauma (11.4%), trigeminal neuralgia/epilepsy (3.4%), and others such as abscesses/cysts (1.4%). The size of the defect ranged from 3 to 340 cm 2 . An overall postoperative complication rate of 2.3% was identified, especially in patients who had previously undergone surgery at the same site. When data were available, contour improvement and high patient satisfaction were reported in 98.8% and 98.3% of the patients. HDPP implants exhibit favorable outcomes for reconstruction of skull defects. Higher complication rates may be anticipated in secondary cranioplasty cases.

Weight gain is an early indicator of injury in ex vivo normothermic limb perfusion (EVNLP).

PURPOSE: There are no established criteria for discontinuing ex vivo normothermic limb perfusion (EVNLP) before irreversible damage occurs. This study evaluates weight gain as an indicator of injury during EVNLP. METHODS: Sixteen Yorkshire pig forelimbs were procured and preserved using EVNLP with a hemoglobin-based oxygen carrier (HBOC-201) or static cold storage. EVNLP continued until termination criteria were met: arterial pressure ≥ 115 mm Hg, compartment pressure > 30 mm Hg, or 20% reduction of oxygen saturation. Limb weight, contractility, hemodynamics, perfusate electrolytes, metabolites and gases were recorded. Muscles were biopsied 6-h, and muscle injury scores (MIS) calculated. Forearm compartment pressures and indocyanine green (ICG) angiography were recorded at endpoint. Outcomes were compared at 2%, 5%, 10%, and 20% limb weight gain. RESULTS: EVNLP lasted 20 ± 3 h. Weight gain was observed after 13 ± 5 h (2%), 15 ± 6 h (5%), 16 ± 6 h (10%), and 19 ± 4 h (20%). Weight correlated positively with MIS (ρ = 0.92, p < 0.0001), potassium (ρ = -1.00, p < 0.0001), pressure (ρ = 0.78, p < 0.0001), and negatively with contractility (ρ = -0.96, p = 0.011). At 5% weight gain, MIS (p < 0.0001), potassium (p = 0.03), and lactate (p < 0.0001) were significantly higher than baseline. Median muscle contractility was 5 [3-5] at 2% weight gain, 4 [1-5] at 5%, 3 [0-4] and 2 [0-2] at 10% and 20%, respectively. At 20% weight gain, contractility was significantly lower than baseline (p = 0.003). Percent weight gain correlated negatively with endpoint ICG hoof fluorescence (r = -0.712, p = 0.047). CONCLUSIONS: Weight gain correlated with microscopic muscle injury and was the earliest evidence of limb dysfunction. Weight gain may serve as a criterion for discontinuation of EVNLP.

Consensus Conference Statement on the General Use of Near-infrared Fluorescence Imaging and Indocyanine Green Guided Surgery: Results of a Modified Delphi Study.

BACKGROUND: In recent decades, the use of near-infrared light and fluorescence-guidance during open and laparoscopic surgery has exponentially expanded across various clinical settings. However, tremendous variability exists in how it is performed. OBJECTIVE: In this first published survey of international experts on fluorescence-guided surgery, we sought to identify areas of consensus and nonconsensus across 4 areas of practice: fundamentals; patient selection/preparation; technical aspects; and effectiveness and safety. METHODS: A Delphi survey was conducted among 19 international experts in fluorescence-guided surgery attending a 1-day consensus meeting in Frankfurt, Germany on September 8th, 2019. Using mobile phones, experts were asked to anonymously vote over 2 rounds of voting, with 70% and 80% set as a priori thresholds for consensus and vote robustness, respectively. RESULTS: Experts from 5 continents reached consensus on 41 of 44 statements, including strong consensus that near-infrared fluorescence-guided surgery is both effective and safe across a broad variety of clinical settings, including the localization of critical anatomical structures like vessels, detection of tumors and sentinel nodes, assessment of tissue perfusion and anastomotic leaks, delineation of segmented organs, and localization of parathyroid glands. Although the minimum and maximum safe effective dose of ICG were felt to be 1 to 2 mg and >10 mg, respectively, there was strong consensus that determining the optimum dose, concentration, route and timing of ICG administration should be an ongoing research focus. CONCLUSIONS: Although fluorescence imaging was almost unanimously perceived to be both effective and safe across a broad range of clinical settings, considerable further research remains necessary to optimize its use.

Applications of multispectral and hyperspectral imaging in dermatology.

Vision is essential in the diagnostic capabilities in the speciality of dermatology. However, humans are limited in colour vision by the trichromatic visual system that we possess. Multispectral and hyperspectral imaging can overcome this limitation and non-invasively provide novel information about a skin lesion at the cellular level. A literature review from January 2019 to March 2021 for hyperspectral and multispectral imaging in the field of dermatology was conducted. Multispectral/Hyperspectral imaging continues to generate significant research and interest in dermatology. Much of this research is on distinguishing melanoma from benign nevi as this could allow for a diagnosis without biopsy. In addition, adding multispectral/hyperspectral imaging to smartphones is being researched in order to create a portable and low-cost device that can be used in remote areas. One of the limitations in developing devices utilizing hyperspectral imaging has been a sacrifice in specificity in order to maximize sensitivity. Potential solutions to combat this that are being researched include combining multispectral/hyperspectral imaging with other imaging modalities such as photoacoustic imaging in order to overcome the limitations of using each individually. Multispectral/Hyperspectral imaging could be an instrumental aid for clinicians in examining, diagnosing and developing the management plan for patient's skin lesions.

Real-time tissue perfusion assessment using fluorescence imaging topography scanning system: A preclinical investigation.

BACKGROUND AND OBJECTIVES: We previously developed a real-time fluorescence imaging topography scanning (RFITS) system for intraoperative multimodal imaging, image-guided surgery, and dynamic surgical navigation. The RFITS can capture intraoperative fluorescence, color reflectance, and surface topography concurrently and offers accurate registration of multimodal images. The RFITS prototype is a promising system for multimodal image guidance and intuitive 3D visualization. In the current study, we investigated the capability of the RFITS system in intraoperative fluorescence vascular angiography for real-time assessment of tissue perfusion. STUDY DESIGN/MATERIALS AND METHODS: We conducted ex vivo imaging of fluorescence perfusion in a soft casting life-sized human brain phantom. Indocyanine green (ICG) solutions diluted in dimethyl sulfoxide (DMSO) and human serum were injected into the brain phantom through the vessel simulating tube (2 ± 0.2 mm inner diameter) by an adjustable flow peristaltic pump. To demonstrate the translational potential of the system, an ICG/DMSO solution was perfused into blood vessels of freshly harvested porcine ears (n = 9, inner diameter from 0.56 to 1.27 mm). We subsequently performed in vivo imaging of fluorescence-perfused vascular structures in rodent models (n = 10). 5 mg/ml ICG solutions prepared in sterile water were injected via the lateral tail vein. All targets were imaged by the RFITS prototype at a working distance of 350-400 mm. RESULTS: 3D visualization of 10 µg/ml ICG-labeled continuous moving serum in the brain phantom was obtained at an average signal-to-background ratio (SBR) of 1.74 ± 0.03. The system was able to detect intravenously diffused fluorescence in porcine tissues with an average SBR of 2.23 ± 0.22. The RFITS prototype provided real-time monitoring of tissue perfusion in rats after intravenous (IV) administration of ICG. The maximum fluorescence intensity (average SBR = 1.94 ± 0.16, p < 0.001) was observed at Tpeak of ~30 seconds after the ICG signal was first detected (average SBR = 1.19 ± 0.13, p < 0.01). CONCLUSIONS: We have conducted preclinical studies to demonstrate the feasibility of applying the RFITS system in real-time fluorescence angiography and tissue perfusion assessment. Our system provides fluorescence/color composite images for intuitive visualization of tissue perfusion with 3D perception. The findings pave the way for future clinical translation.

Two Decades of Hand Transplantation: A Systematic Review of Outcomes.

ABSTRACT: Hand transplantation for upper extremity amputation provides a unique treatment that restores form and function, which may not be achieved by traditional reconstruction and prosthetics. However, despite enhancing quality of life, hand transplantation remains controversial, because of immunological complications, transplant rejection, and medication effects. This systematic literature review sought to collect information on current experiences and outcomes of hand transplants to determine the efficacy and utility of hand transplants. The databases PubMed, Scopus, and Embase were analyzed with combinations of "hand" or "upper extremity" or "arm" and "transplant" or "allograft," with information collected on recipient characteristics, details of transplant, immunological outcomes, functional outcomes, and complications. Functional outcomes, as measured by Disabilities of Arm, Shoulder and Hand score, were compared between patient groups using Wilcoxon signed-rank test or 1-way analysis of variance test and post hoc Tukey test. Within the 108 articles that fulfilled inclusion and exclusion criteria, there were 96 patients with 148 hand transplants. There were 57 patients who experienced acute rejection and 5 patients with chronic rejection. Disabilities of the Arm, Shoulder and Hand scores significantly decreased after hand transplantation and were significantly lower for distal transplants compared with proximal transplants. There were 3 patients with concurrent face transplantation and 2 patients with simultaneous leg transplants. Sixteen patients experienced amputation of the hand transplant, and there were 5 deaths. This study found that hand transplantation provides significant restoration of function and form, especially for proximal transplants. Reduction in complications, such as rejection and amputation, can be achieved by decreasing medication cost and patient education.

Repair Sequence and Management of the Premaxilla in Patients With Bilateral Cleft Lip and Palate: A Systematic Review of the Literature.

BACKGROUND: Bilateral cleft lip and palate (BCLP) remains a difficult surgical problem due to the severely protruding premaxillary segment, with no consensus of optimal treatment sequence in older patients. A systematic review of the literature was performed to assess the current status of BCLP repair based on age. METHODS: A PRISMA systematic review of the PubMed, Web of Science, and Embase databases was performed using a series of search terms related to BCLP. Studies were categorized based on the age of presentation, repair sequence, and technique. RESULTS: The database search identified 381 articles. Of these, 72 manuscripts were ultimately included. The lip was repaired first in 1077 patients (86.0%), palate first in 161 patients (12.9%), and simultaneous lip and palate in 14 patients (1.1%). Patients less than 6 months old received lip repair first (n = 959, 98.6%), with complications of unaesthetic appearance (n = 86, 62.3%) and midface retrusion (n = 41, 34.1%) in younger patients and wound dehiscence (n = 8, 40%) in older patients. Primary lip repair was preceded by presurgical orthopedics (n = 760) or lip adhesion (n = 272) to reduce lip tension with nasoalveolar molding (n = 452, 62.9%) or the Latham device (n = 282, 37.1%). In older patients, the palate was repaired first or premaxillary setback (n = 222) was indicated in protruded premaxillae greater than 10 mm, but carried the risk of premaxilla mobility (n = 20, 37.7%) and midface retrusion (n = 10, 18.9%). CONCLUSION: In younger patients, lip repair is performed first with preoperative orthopedics or lip adhesion. In older patients, the palate is more commonly repaired first compared with the lip; however, there is no difference in complication rate.

Maxillary and Mandibular Healing After Facial Allotransplantation.

INTRODUCTION: Facial transplantation has emerged as a viable option in treating devastating facial injuries.Despite the high healing rate of Le Fort III and bilateral sagittal split osteotomies (BSSO) in nontransplant patients, few studies have reported assessment of maxillary and mandibular healing in face transplant patients compared with nontransplant patients. The aim of this study was to examine differences in bone healing in our patients. PATIENTS AND METHODS: A retrospective chart review was conducted of facial allotransplantation patients at the Cleveland Clinic from December 2008 to inception. Demographics such as age, date of birth, and sex were recorded. Additional variables included procedures, revisions, reoperations, medications, and bone stability and healing. Computed tomography (CT) images assessed the alignment of skeletal components, bony union quality, and stability of fixation. RESULTS: Three patients were included: 2 had Le Fort III segment transplantation, and 1 had transplantation of both a Le Fort III segment and mandibular BSSO. The Le Fort III segment in all patients exhibited mobility and fibrous union at the Le Fort III osteotomy on CT. In contrast, the BSSO healed uneventfully after transplantation and revision surgery, with bony union confirmed by both CT and histology of the fixation area between the donor and recipient mandible bilaterally. No patients with midfacial fibrous union required revision of the nonunion as they were clinically asymptomatic. CONCLUSION: Le Fort osteotomy demonstrates inferior healing in facial transplantation compared with the nontransplant population. In contrast, the successful healing in the mandible is likely owing to the high density of rich cancellous bone.

Mixed Reality and 3D Printed Models for Planning and Execution of Face Transplantation.

OBJECTIVE: The aim of this study was to evaluate a novel holographic craniofacial surgical planning application and its implementation throughout the planning and operative stages of facial transplantation by performing a critical analysis of comparative utility, cost, and limitations of MR and 3D printing. SUMMARY OF BACKGROUND DATA: Face transplantation is a highly complex form of craniofacial reconstruction requiring significant planning, knowledge of patient-specific spatial relationships, and time-sensitive decision making. Computer-aided 3D modeling has improved efficiency and outcomes of complex craniofacial reconstruction by enabling virtual surgical planning and 3D printed model generation. MR technology can enhance surgical planning, improve visualization, and allow manipulation of virtual craniofacial biomodels within the operative field. METHODS: Accounting for the time-sensitive nature of face transplantation, a unique, highly coordinated workflow for image acquisition and processing was designed to facilitate rapid holographic rendering and 3D printing. During recent face transplantation, both holographic and 3D printed models were utilized, and the time and cost of fabrication were compared. RESULTS: Holographic models required less time and cost for fabrication. They provided both comprehensive visualization of 3D spatial relationships and novel means to perform VSP and virtual face transplantation by interacting with and manipulating patient-specific, anatomic holograms. CONCLUSION: Time efficiency, low-cost biomodel production, provision of unlimited preoperative surgical rehearsal, and potential for intraoperative surgical guidance makes holographic VSP and MR highly promising technology for use in complex craniofacial surgery.

Treatment Strategies of Complications of Breast Implants Associated With Ventriculoperitoneal Shunts: A Case Report and Review of the Literature.

ABSTRACT: Breast augmentation is among the most commonly performed cosmetic procedures in the United States. As these patients age or develop comorbidities, surgeons across many other disciplines will inevitably encounter these patients in their own practices. Consequently, surgeons must be aware of the potential interactions between breast implants and devices commonly used in their fields. This case, the second of its kind encountered by our own department, describes a woman who suffered one such interaction: migration and coiling of a ventriculoperitoneal shunt around her breast implant. A systematic review was conducted to characterize breast-related ventriculoperitoneal shunt complications reported in the literature and generate an algorithm for management of the most commonly reported scenarios. Recognition of potential complications will aid surgeons in appropriate operative planning and prevention of these adverse events.

Successful Treatment of Life-Threatening COVID-19 Infection in a Face Transplant Recipient.

ABSTRACT: Recent literature suggests that severe COVID-19 is associated with an exaggerated immune response during viral infection, resulting in cytokine storm. Although elevated plasma interleukin 6 (IL-6) has been reported in severe COVID-19 infections, and treatment with anti-IL-6 (tocilizumab) has demonstrated promising outcomes both domestically and abroad, reports remain limited and therapeutic regimens vary considerably. Furthermore, research pertaining to transplant recipients, COVID-19 infection, and anti-IL-6 therapy remains underdeveloped. Herein, we report the successful treatment of the only reported facial vascularized composite allograft (VCA) recipient who contracted severe COVID-19 and the first reported VCA recipient with COVID-19 infection that received anti-IL-6 immunotherapy resulting in an excellent recovery despite his multiple preexisting and COVID-19-related comorbidities-adult respiratory distress syndrome, acute renal failure requiring hemodialysis, and concomitant sepsis due to extensive drug-resistant bacterial pneumonia upon presentation. To date, he has not demonstrated any anti-IL-6 drug-related adverse effects. This preliminary report also suggests that our immunosuppressed VCA patients can indeed demonstrate a robust cytokine response during COVID-19 infection and may also respond favorably to emerging anticytokine immune therapies. We hope that our experience proves helpful to other centers that might encounter critically ill VCA recipients in the ongoing COVID-19 pandemic and in the years to follow.

Cranial Vault Remodeling in Children With Ventricular Shunts.

INTRODUCTION: Cranial vault surgery in children with ventricular shunts is more complex due to the possible interference of shunt location with surgical planning and increased risk of shunt related complications. The study evaluated the management of ventricular shunts during cranial vault remodeling (CVR) and subsequent outcomes and complications following CVR. METHODS: An IRB-approved retrospective chart review was performed including patients who underwent CVR in presence of a ventricular shunt. Measured outcomes were number of shunt revisions following CVR, 30-day complication rate, 3-month complication rate, and post-CVR Whitaker classification. Finally, a review of the literature was performed, and our results were compared to previous reports. RESULTS: Eleven patients met the inclusion criteria. Ventricular shunt was not exposed in 18%; exposed and not revised in 54%; exposed and left on a bone peninsula in 18% and simultaneously exposed and revised in 18%. Two patients experienced complications within 30-days. Three additional patients experienced complications within 3-months. An average of 2.2 shunt revisions per patient were performed following CVR. Whitaker classification was I in 7 patients, II in 1 patient and III in 2 patients. Shunt revision rate for patients undergoing CVR for hydrocephalic macrocephaly was on average of 1.2 and 1.9 for shunt-induced craniosynostosis in literature. CONCLUSIONS: Cranial vault abnormalities in the presence of a ventricular shunt can be effectively treated with CVR. The presence of a shunt does not seem to interfere with final head shape. While leaving the shunt unexposed may appear less morbid, shunt related complications can still occur with this approach.

An Anatomical Study of the Foramen Ovale for Neuromodulation of Trigeminal Neuropathic Pain.

OBJECTIVE: Neuromodulation for trigeminal pain syndromes such as trigeminal neuropathic pain (TNP) necessitates accurate localization of foramen ovale (FO). The Härtel-type approach is very well-established and safe, ideal for temporary cannulation of the FO for ablative procedures such as balloon microcompression. A key shortcoming of the Hartel approach for placement of neuromodulation leads is the limited opportunity for secure anchoring. The aim of this study is to introduce a novel surgical approach for the treatment of TNP by investigating key osseous landmarks and their spatial relationships to the FO. MATERIALS AND METHODS: Sixteen sides of cadaver heads were dissected to investigate a surgical route of the FO via transoral gingival buccal approach. Alveolar arch of the maxilla and zygomaticomaxillary suture were selected to serve as an osseous landmark for the surgical guidance to the FO. Through the intraoral route, a needle simulating electrode was traversed to aim the FO from the inferior lateral to the superior medial direction to target specific fibers of the aimed division of the nerve. RESULTS: Visual identification and access to the trigeminal nerve at the external opening of FO was successful in all 16 hemifacial cadavers. A needle successfully targeted different regions of the trigeminal nerve by changing the angle of the trajectory allowing the needle to reach a specific division of the trigeminal nerve. CONCLUSIONS: This study provides a novel means of approaching the FO via transoral gingival buccal access.

Face Transplantation for Granulomatosis With Polyangiitis (Wegener Granulomatosis): Technical Considerations, Immunological Aspects, and 3-Year Posttransplant Outcome.

BACKGROUND: We report new data for a rare face transplant performed 3 years ago. Granulomatosis with polyangiitis (GPA) (Wegener) is a severe autoimmune necrotizing vasculitis and parenchymal inflammatory disease that can affect any organ including those of the craniofacial region. Skin involvement manifests as malignant pyoderma. This account (1) highlights the technical details of face transplantation for this unique indication, (2) reports the 3-year posttransplant outcome, and (3) describes relevant immunological aspects. METHODS: A Le Fort III near-total face and near-total scalp transplant was performed after extensive trauma and subsequent bone and soft tissue infection in a patient with GPA. Incisions were planned along facial aesthetic subunits. The vascular pedicle comprised the facial and superficial temporal arteries bilaterally. The functioning left eye was preserved and fitted into the donor tissues. RESULTS: The procedure took 21 hours, and transfusion was limited to 4 units of packed red cells. Early medical and surgical complications were successfully treated. At 3 years, acceptable aesthetic outcome was achieved with adequate color match and scalp hair growth. The patient has recovered light touch, temperature, and 2-point discrimination and has evidence of symmetric cheek elevation albeit with limited eyelid and frontalis function. GPA relapse did not occur. Four acute rejections were fully reversed. CONCLUSIONS: This case represents a new underlying disease (trauma + GPA) leading to face transplantation and a unique clinical scenario where allografting was indicated for potentially life-threatening and sight-preserving reasons and not for mere functional and aesthetic concerns. Despite complexity, 3-year clinical outcome is encouraging, and the patient is no longer at risk for dural exposure, meningitis, and related morbidity.

Anatomical Location of the Infraorbital Foramen in Infant Dry Skulls: Implications for Cleft Surgery.

BACKGROUND: Infraorbital foramen (IOF) is an important anatomical landmark in cleft lip surgery. The location of IOF within the maxilla of infants is different from adults. However, little information about anatomy of IOF in infants exists in the literature. This study aims to determine the location of IOF in infant dry skulls based on key surgical landmarks. METHODS: All dry skulls under age 2 years old were selected from the Hamann-Todd Human Osteological Collection at the Cleveland Museum of Natural History (Cleveland, OH). Specimens without cranial bones or complete maxilla were excluded. Seven anatomical measurements were taken on each side of the face for each individual skull (14 measurements for each skull). Anatomical landmarks used for the measurements included infraorbital rim, aperture piriformis, alveolar ridge, zygomaticomaxillary buttress, anterior nasal spine (ANS), and inferolateral corner of the aperture piriformis. RESULTS: Twenty-seven halves of 14 dry skulls were included in the final analysis. The mean age of specimens was 0.57 years. Mean distances from infraorbital foramen to infraorbital rim, aperture piriformis, alveolar ridge, zygomaticomaxillary, and ANS buttress were 4.11 ±â€Š0.82, 9.4 ±â€Š1.62, 12.7 ±â€Š2.71, 11.7 ±â€Š1.54, and 18.4 ±â€Š2.11 mm, respectively. CONCLUSION: This study also shows that the infraorbital foramen in infants is located at the level of the ANS or within 2 mm higher and that the distance between the infraorbital rim and foramen is only 3 to 4 mm. These findings should be applied to the cleft population with discretion.

Soft Tissue Reconstruction in Patients With Hemifacial Microsomia: A Systematic Review of the Literature.

INTRODUCTION: Hemifacial microsomia is the most common congenital disorder of the face after cleft lip and palate. While treatment of the bony abnormalities has been well documented, less attention has been paid to correction of the soft tissue deformity. This study aimed to systematically review the literature addressing the techniques utilized to correct the soft tissue deformity in hemifacial microsomia. MATERIALS AND METHODS: A comprehensive review of peer-reviewed literature regarding the management of soft tissue reconstruction in patients with hemifacial microsomia was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement. Odds ratio was used to assess differences in complication rates between reconstructions performed with free tissue transfer and fat grafting. RESULTS: The literature search yielded 38 articles that were fully reviewed for data extraction. Articles were grouped into one of 5 reconstructive modalities-pedicled flap, microvascular free tissue transfer, structural fat grafting, alloplastic implant, and functional reconstruction. Microvascular free tissue transfer had a complication rate of 27.1%, while structural fat grafting had a complication rate of 4.2% (odds ratio 6.7, P = 0.0003). CONCLUSIONS: Microvascular free tissue transfer likely provides greater volume than fat grafting at the cost of a higher complication rate. Mild to moderate soft tissue deformity can be corrected with serial fat grafting. However, severe soft tissue deformity is better corrected with microvascular free tissue transfer. When performing free tissue transfer, one should be prepared for recipient vessel anomalies. To provide adequate augmentation with isolated fat grafting, multiple sessions are likely required.

Developing a protocol for normothermic ex-situ limb perfusion.

BACKGROUND: Ischemia time represents a significant limitation for successful extremity transplantation because of the rapid deterioration of ischemic muscle. Normothermic ex-situ preservation is an emergent method to prolong the organ viability following procurement, by replicating the physiologic conditions. The aim of this study was to develop an ex-situ normothermic limb perfusion system to preserve the viability and function of porcine limbs for 12 hours following procurement. METHODS: A total of 18 swine limbs were perfused. Thirteen limbs were used to develop the perfusion protocol. Five limbs were perfused according to the optimized protocol. These limbs were perfused at 39°C for twelve hours using an oxygenated colloid solution containing red blood cells. Glucose and electrolytes were kept within physiologic range by partial perfusate exchange. Limb specific perfusion quality was assessed by muscle contractility upon electrical nerve stimulation, compartment pressure, creatine kinase (CK) and myoglobin concentrations, tissue oxygen saturation (near infrared spectroscopy), indocyanine green angiography, and infrared radiation by thermographic imaging. RESULTS: The last five limbs reached the 12 hours' perfusion target maintaining normal compartment pressure (16.4 ± 8.20 mmHg), minimal weight increase (0.54 ± 7.35%), and mean muscle temperature of 33.6 ± 1.67°C. Myoglobin and CK concentrations were 875 ± 291.4 ng/mL, and 53344 ± 14850.34 U/L, respectively, at the end of perfusion. Muscle contraction was present in all limbs until cessation of perfusion. Differences in uniformity and quality of distal perfusion were identified with thermography and angiography imaging at 12 hours of perfusion. CONCLUSIONS: Ex-situ normothermic limb perfusion preserves swine limb physiology and function for at least 12 hours.

The Cardioplastic Approach to the Treatment of Infected Aortic Grafts.

BACKGROUND: Aortic graft infection (AGI) is a rare complication following reconstructive aortic surgery, yet it represents a significant source of morbidity and mortality. There is no consensus regarding the optimal surgical management, due in part to the small cohorts of patient reports. Pedicled muscle or omental flap coverage of AGI has been shown to improve outcomes, making them a valuable consideration in the treatment algorithm. Thus, we aim to compile and evaluate cases of autologous vascularized tissue (AVT) in the treatment of infected aortic grafts, summarizing location specific trends, treatments, and outcomes. METHODS: A comprehensive review of peer-reviewed literature regarding the management of AGI was performed. Data collected included patient characteristics, original procedure, pathogen, infection location, tissue utilized, technique of tissue isolation and delivery, staging, outcome, length of follow-up, and level of evidence. RESULTS: Ninety-four cases of AGI managed with AVT transfer were identified. Infection of ascending aorta grafts accounted for 59% of cases, followed by a combination of ascending aorta and aortic arch (21%), the descending thoracic aorta (18%), and the thoracoabdominal aorta (2%). The infected graft was preserved in 81% of cases, followed by debridement and AVT coverage. The omentum was the most commonly applied flap (69%) for all divisions of the aorta followed by the pectoralis major (19%), the rectus abdominis (5%), and latissimus dorsi (4%). Mortality was limited, and the Powered by Editorial Manager and ProduXion Manager from Aries Systems Corporation overall survival was 93% (7 deaths), with a mean follow-up of 33.5 months. CONCLUSIONS: Autologous vascularized tissue coverage has proven to be a successful approach for treatment of infected aortic grafts. Although the incidence of AGI is rare, it represents an area of scarce evidence-based literature that warrants increased attention and surgical refinement. These results, which show a remarkably low infection-related mortality rate (3%), should encourage interdisciplinary collaboration with the plastic surgeon, cardiothoracic surgeon, and infectious disease specialists with the goal of improving outcomes in the treatment of infected aortic grafts.

Surgical Management of Mandibular Intraosseous Schwannomas.

Intraosseous schwannomas of the mandible are rare tumors that usually arise from peripheral nerve sheaths of the main trunk or branches of the inferior alveolar nerve (IAN).A systematic review of the English literature through PubMed was conducted from 1945 to 2016. Forty-nine patients of mandibular intraosseous schwannomas were identified. The most common location of the tumor was the posterior mandible (61.2%). There were 28 patients in whom the tumor involved the IAN (57.1%). The most commonly performed procedures included enucleation through a mucoperiosteal flap and a bone window (73%), curettage (10%), segmental mandibulectomy (10%), and sagittal split ramus osteotomy (6%). The recurrence rate was 6%: all 3 recurrent patients occurred in the posterior area. The authors report a 72-year-old female with a schwannoma of the IAN which was removed through a sagittal split of the mandible, although there was a bony defect of the external cortex after biopsy of the lesion. The nerve was reconstructed with a sural nerve graft.Due to the slow growing nature and encapsulation of schwannomas, surgical resection seems the best treatment with optimal functional outcomes and low recurrence rate even with a minimally invasive approach. Sagittal split ramus osteotomy and segmental mandibulectomy are reserved to large or posterior lesions to aid with radical resection or improve exposure and reconstruction.