Systematic review of pathologic markers in skin ischemia with and without reperfusion injury in microsurgical reconstruction: Biomarker alterations precede histological structure changes.

BACKGROUND: Ischemia and ischemia-reperfusion injury contribute to partial or complete flap necrosis. Traditionally, skin histology has been used to evaluate morphological and structural changes, however histology does not detect early changes. We hypothesize that morphological and structural skin changes in response to ischemia and IRI occur late, and modification of gene and protein expression are the earliest changes in ischemia and IRI. METHODS: A systematic review was performed in accordance with PRISMA guidelines. Studies reporting skin histology or gene/protein expression changes following ischemia with or without reperfusion injury published between 2002 and 2022 were included. The primary outcomes were descriptive and semi-quantitative histological structural changes, leukocyte infiltration, edema, vessel density; secondary outcomes were quantitative gene and protein expression intensity (PCR and western blot). Model type, experimental intervention, ischemia method and duration, reperfusion duration, biopsy location and time point were collected. RESULTS: One hundred and one articles were included. Hematoxylin and eosin (H&E) showed inflammatory infiltration in early responses (12-24 h), with structural modifications (3-14 days) and neovascularization (5-14 days) as delayed responses. Immunohistochemistry (IHC) identified angiogenesis (CD31, CD34), apoptosis (TUNEL, caspase-3, Bax/Bcl-2), and protein localization (NF-κB). Gene (PCR) and protein expression (western blot) detected inflammation and apoptosis; endoplasmic reticulum stress/oxidative stress and hypoxia; and neovascularization. The most common markers were TNF-α, IL-6 and IL-1ß (inflammation), caspase-3 (apoptosis), VEGF (neovascularization), and HIF-1α (hypoxia). CONCLUSION: There is no consensus or standard for reporting skin injury during ischemia and IRI. H&E histology is most frequently performed but is primarily descriptive and lacks sensitivity for early skin injury. Immunohistochemistry and gene/protein expression reveal immediate and quantitative cellular responses to skin ischemia and IRI. Future research is needed towards a universally-accepted skin injury scoring system.

Orthotopic forelimb transplantation in a Yucatan minipig model: Anatomic and in vivo study.

INTRODUCTION: Above elbow transplants represent 19% of the upper extremity transplants. Previous large-animal models have been too distal or heterotopic, did not use immunosuppression and had short survival. We hypothesize that an orthotopic forelimb transplant model, under standard immunosuppression, is feasible and can be used to address questions on peri-transplant ischemia reperfusion injury, and post-transplantation vascular, immunologic, infectious, and functional outcomes. MATERIALS AND METHODS: Four forelimbs were used for anatomical studies. Four mock transplants were performed to establish technique/level of muscle/tendon repairs. Four donor and four recipient female Yucatan minipigs were utilized for in-vivo transplants (endpoint 90-days). Forelimbs were amputated at the midarm and preserved through ex vivo normothermic perfusion (EVNP) utilizing an RBC-based perfusate. Hourly perfusate fluid-dynamics, gases, electrolytes were recorded. Contractility during EVNLP was graded hourly using the Medical Research Council scale. EVNP termination criteria included systolic arterial pressure ≥115 mmHg, compartment pressure ≥30 mmHg (at EVNP endpoint), oxygen saturation reduction of 20%, and weight change ≥2%. Indocyanine green (ICG) angiography was performed after revascularization. Limb rejection was evaluated clinically (rash, edema, temperature), and histologically (BANFF classification) collecting per cause and protocol biopsies (POD 1, 7, 30, 60 and endpoint). Systemic infections were assessed by blood culture and tissue histology. CT scan was used to confirm bone bridging at endpoint. RESULTS: Animals 2, 4 reached endpoint with grade 0-I rejection. Limbs 1, 3 presented grade III rejection on days 6, 61. CsA troughs averaged 461 ± 189 ng/mL. EVNLP averaged 4.3 ± 0.52 h. Perfusate lactate, PO2 , and pH were 5.6 ± 0.9 mmol/L, 557 ± 72 mmHg and 7.5 ± 0.1, respectively. Muscle contractions were 4 [1] during EVNLP. Transplants 2, 3, 4 showed bone bridging on CT. CONCLUSION: We present preliminary evidence supporting the feasibility of an orthotopic, mid-humeral forelimb allotransplantation model under standard immunosuppression regimen. Further research should validate the immunological, infectious, and functional outcomes of this model.

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.

Prognosis-Guided Reconstruction of Scalp and Skull Defects in Neurosurgical Patients.

BACKGROUND: This study aimed to formulate reconstructive recommendations for neurosurgical patients presenting with scalp and/or skull defects based on outcomes in a large series of patients. METHODS: An institutional review board-approved retrospective review of patients who underwent scalp and/or calvarial reconstruction was conducted. Complications were divided into minor and major; early, intermediate, and late. Univariate logistic regression models were conducted to identify independent predictors of complications. Mann-Whitney U tests were used to compare survival time. Kaplan-Meier curves were developed to compare exposure of titanium and bone cranioplasties. RESULTS: One hundred seventy-one patients who underwent 418 procedures were included (median 1 [1-3] surgeries per patient). Average age was 55 ± 15 years; 53% of patients were male. Median follow-up was 25.5 months [13.9-55.6 months], and 57 patients (33%) were deceased. Complications occurred following 48% of procedures; most common were titanium hardware exposure (36%), nonhealing wounds (23%), and infection (9%). Titanium cranioplasties became exposed 0.47 months [0.3-4.0 months] postoperatively. Frontal defect location was an independent predictor of major complications (odds ratio, 1.59; 95% confidence interval, 1.06-2.39; P = 0.026). Mortality rate for malignant intracranial neoplasms was 68.4% (median survival, 4.3 months), 39.1% for malignancies of both scalp and skull (7.0 months), 37.5% for scalp cancers (16.0 months), and 16.7% for meningiomas (28.2 months). CONCLUSIONS: Neurosurgical patients requiring scalp and/or skull reconstruction are a complex population undergoing multiple procedures with high complication rates. Given high exposure rate of titanium hardware shortly after reconstruction, titanium cranioplasty is recommended for patients with a prognosis less than 2 to 8 months.

A Systematic Review of the Outcomes of Carpal Ligament Release in Severe Carpal Tunnel Syndrome.

PURPOSE: Indications for surgical treatment of severe carpal tunnel syndrome (CTS) are controversial. The aim of this study was to review the outcomes reported in the literature of carpal tunnel release in patients with severe CTS. METHODS: A systematic review of the outcomes of carpal tunnel release in patients with severe CTS was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Outcome measures included change in symptoms, sensation (2-point discrimination, light touch), thenar atrophy, strength (power and pinch grip), electrophysiology, median nerve morphology, and patient-reported outcome measures. Outcomes are reported by ranges of the percentage of patients/hands improved in the included studies. RESULTS: Thirty-eight papers were selected, representing 2,531 patients and 2,712 hands. Demographic information on age and sex were available for a total of 1,542 patients. Mean age ranged from 49.8 to 83 years and 72% were female. All studies that assessed patient-reported outcome measures before and after surgery reported significant improvements. Complete resolution of paresthesia occurred in 55%-98% of hands across different studies. Resolution of numbness occurred in between 39% and 94% of hands. Pain completely resolved in 64%-100% and weakness in 60%-75% of hands. Two-point discrimination and light touch improved postoperatively. Power grip, key, tripod, index-thumb pulp pinch, and thumb opposition increased. Motor and sensory amplitudes, distal motor latencies, and sensory conduction velocities improved. Patient-reported outcomes indicated symptomatic improvement and reduced disability. CONCLUSIONS: Symptomatic improvement following carpal tunnel release in patients with severe CTS can occur. Patients should be counseled about the unpredictability of the outcomes and factors that might affect outcomes. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Upper Extremity Infections in the Transplant Population.

PURPOSE: As the duration of lifetime survival after organ transplantation continues to increase, the consequences of long-term immunosuppression, such as opportunistic and rare infections, are a high-risk reality. This study examined upper extremity infections in the transplant population to determine the current clinical risk profile, management, and outcomes. METHODS: An institutional database of 16,640 patients who underwent transplantation was queried for upper extremity infections from 2005 to 2017, defined as the presence of infection from the shoulder to the fingertips. The resulting data were analyzed using multivariable linear and logistic regression modeling. RESULTS: A total of 230 eligible patients experienced upper extremity infections at a mean age of 54.1 ± 15.3 years, occurring, on average, 7.9 ± 8.6 years after transplantation. The most commonly transplanted organ was the kidney (51.3%), followed by the liver (20%). The most common location of infection was the forearm (31.7%), digits (27.4%), and upper arm (17%). The most common types of infection were cellulitis (69.1%), abscess (33.5%), joint sepsis (6.5%), infectious tenosynovitis (3.9%), and osteomyelitis (1.3%). Patients taking an antifungal medication, those who had a joint infection, or those who had undergone lung transplantation had an approximately 2.5-day longer stay in the hospital. For every 1-year increase in age at the time of transplantation, the time from transplantation to infection decreased by 0.21 years. Those who had undergone bone marrow transplantation or those who were taking tacrolimus were expected to have approximately 8- and 6-year decreases, respectively, in the time from transplantation to infection. CONCLUSIONS: Upper extremity infections should be individually evaluated and treated because of the heterogeneity of transplant type, immunosuppression medications, the age of the patient, and infection characteristics. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic IV.

Comparing the educational quality of free flap technique videos on public and paid platforms.

BACKGROUND: Surgical videos are reshaping the landscape for surgical education. As this form of education has rapidly grown and become a valuable resource for experienced surgeons, residents, and students, there is great variability in the presentation of what is offered. This study aimed to assess and compare the educational quality of free flap instructional videos on public and paid platforms. METHODS: Free flap videos from public (YouTube) and paid (American Society of Plastic Surgeons Education Network and Plastic and Reconstructive Surgery Journal) sources were screened independently by three reviewers. Sample size was calculated to reach 80% power. The educational quality of the videos was determined using a modified version of Laparoscopic Surgery Video Educational Guidelines (0-6 low, 7-12 medium, 13-18 high). Professionally-made videos were identified per lighting, positioning, and video/imaging quality. Interrater reliability between the three reviewers was calculated. The educational quality of the videos was compared between public and paid sources using Mood's median test. Pearson's correlation coefficient was utilized to assess the correlation between video length and educational quality. RESULTS: Seventy-six videos were included (40 public, 36 paid). The median video lengths for public and paid platforms were 9.43(IQR = 12.33) and 5.07(IQR = 6.4) min, respectively. There were 18 high, 16 medium, and 6 low-quality public videos, versus 13 high, 21 medium, and 2 low-quality paid videos. Four public and seven paid videos were identified as professionally made. Interrater reliability was high (α = .9). No differences in educational quality were identified between public and paid platforms. Video length was not correlated with quality (p = .15). A video library compiling public high-quality videos was created (https://www.youtube.com/playlist?list=PL-d5BBgQF75VWSkbvEq6mfYI--9579oPK). CONCLUSIONS: Public and paid platforms may provide similar surgical education on free tissue transfer. Therefore, whether to subscribe to a paid video platform for supplemental free flap education should be determined on an individual basis.

Orthognathic Surgery in Ehlers-Danlos Syndrome: Review of the Literature and Case Report.

EDS (Ehlers-Danlos Syndrome) is a heterogenous group of inheritable connective tissue disorders that commonly precludes patients from being elective surgical candidates. Patients with EDS are at a higher risk of increased bleeding, delayed wound healing, and temporomandibular joint pain refractory to treatment. Historically, patients with EDS and TMJ disorders are considered inappropriate surgical candidates due to a higher risk of delayed wound healing, increased risk for uncontrolled post-surgical bleeding, and unsubstantiated outcomes in regards to elective orthognathic surgery. A review of the literature demonstrates a paucity of data accounting the use of orthognathic surgery and maxillary-mandibular advancement in patients with EDS. The present study reports on the use of orthognathic double jaw surgery in a patient with a known diagnosis of hypermobile EDS, history of TMJ subluxation and pain. This case describes a 47-year-old woman with a history of hypermobile EDS who presented with Angle Class II malocclusion, Class II skeletal pattern, and clockwise rotation of the occlusal plane associated with pain at the bilateral TMJs. She underwent maxillary-mandibular advancement with counterclockwise rotation of the occlusal plane and genioplasty. The surgery was without complications, and at 22 months follow up, the patient healed uneventfully with improvement of pain and range of motion. This case report demonstrates that with diligent patient selection, orthognathic surgery in patients with EDS can be safe and effective and should not be an absolute contraindication.

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.

Breast Implant-Related Outcomes After Cardiothoracic Surgeries and Electrophysiologic Procedures.

BACKGROUND: Outcomes related to preexisting breast implants after cardiothoracic procedures are poorly characterized. This study evaluated complications after minimally invasive cardiac surgery (MICS), median sternotomy (MS), and electrophysiologic procedures (EP) in patients with preexisting breast implants. METHODS: A retrospective review of patients with prior breast implants who underwent MICS, MS, or EP from 1994 to 2019 was performed. Demographic, treatment, and outcome characteristics were recorded. χ 2 Test and analysis of variance were used to perform statistical comparisons. RESULTS: In total, 78 patients (37 MICS, 21 MS, and 20 EP) were identified. Mean breast implant age was 13.3, 11.7, and 10.2 years, respectively ( P = 0.235). Intraoperative plastic surgeon involvement was present in 26 (70.3%) MICS cases, compared with 2 (9.5%) MS and 0% EP ( P < 0.001). Intraoperative rupture occurred in 5 (13.5%) MICS cases and no MS or EP cases ( P < 0.001). Postoperative implant complications occurred in 6 (16.2%) MICS, 8 (38.1%) MS, and 5 (25.0%) EP ( P = 0.350) cases, with median time to complication of 5.9, 5.4, and 38.9 months, respectively ( P = 0.596). Revision surgery was performed in 5 (13.5%) MICS, 7 (33.3%) MS, and 5 (25.0%) EP ( P = 0.246) cases. On multivariate analysis, lack of intraoperative plastic surgeon involvement ( P = 0.034) and breast implant age ( P = 0.001) were significant predictors of postoperative complications. CONCLUSIONS: Long-term complication rates are highest among patients with breast implants undergoing MS. Plastic surgeon involvement was significantly associated with fewer postoperative complications. Our results support a multidisciplinary approach to managing breast implants during cardiothoracic procedures.

Youngest Composite Full-Face Transplant: A Model for Vascularized Composite Allograft in Younger Populations.

BACKGROUND: The field of face transplantation continues to evolve, with more complex defects being addressed, and, at the same time, increased outcome expectations. Given our unique long-term experience in this field, we consented one of the youngest patients to undergo a full-face transplant. METHODS: An 18-year-old woman presented with complete destruction of her central face and craniofacial structures. She had coexisting major injuries, including pituitary gland, visual axis, and motor control. After extensive rehabilitation and reconstruction techniques, the patient underwent face transplant on May 4, 2017, at the age of 21 years. RESULTS: The total operative time for the recipient was 26 hours. There were no major perioperative complications. Since transplant, the patient has undergone 3 revision surgeries. She is near completely independent from a daily life activity standpoint. She has had 1 episode of rejection above grade II that was successfully treated with a short-term increased in immunosuppression. CONCLUSIONS: Contrary to data in solid organ transplantation where youth is associated with increased risk of rejection, our current algorithm in immunosuppression, combined with this patient's compliance, has led to only 1 rejection episode beyond grade II. This successful transplant can serve as a model for future vascularized composite transplants in younger populations.

Combined Treatment of Trapeziometacarpal Joint Arthritis and Scapholunate Advanced Collapse Wrist.

PURPOSE: The combined treatment of trapeziometacarpal joint arthritis and scapholunate advanced collapse (SLAC) wrist presents unique challenges. The consequences of the loss of radial column support caused by scaphoidectomy and trapeziectomy are not well known. The purpose of this study was to evaluate the outcomes of the simultaneous and staged treatment of trapeziometacarpal joint arthritis and SLAC wrist. METHODS: A retrospective review of patients who underwent surgery for both trapeziometacarpal joint arthritis and SLAC wrist was performed. The wrist and thumb range of motion; grip and pinch strength; pain; quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) scores; and radiographs were analyzed. RESULTS: Twenty-four patients who underwent both trapeziectomy and 1 of 3 procedures for SLAC wrist (4-corner fusion [n = 10]), proximal row carpectomy [n = 9], and total wrist arthroplasty [n = 5]) in a single stage (n = 10) or in 2 stages (n = 14) were included. The median age was 63 years. The median follow-up period was 35 months. Twelve (50%) patients underwent complete scaphoidectomy, and 12 (50%) patients underwent partial scaphoidectomy. All 3 procedures resulted in an improvement in pain at rest, pain during activity, and quick Disabilities of the Arm, Shoulder and Hand scores. The final range of motion, grip and pinch strength, and complication rates were consistent with those reported in the literature for isolated procedures. CONCLUSIONS: Trapeziometacarpal joint arthritis and SLAC wrist may be treated either simultaneously or in stages. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic V.

Anthropometric Cranial Measurements in Metopic Craniosynostosis/Trigonocephaly: Diagnostic Criteria, Classification of Severity and Indications for Surgery.

ABSTRACT: Metopic craniosynostosis is the second most frequent type of craniosynostosis. When the phenotypic presentation has been deemed severe the treatment is surgical in nature and is performed in infancy with fronto-orbital advancement and cranial vault remodeling. At the time of this writing, there is no consensus regarding an objective evaluation system for severity, diagnostic criteria, or indications for surgery. This study aims to review the anthropometric cranial measurements and the relative diagnostic criteria/classification of severity/surgical indications proposed so far for this skull malformation, and to investigate if there is any scientific support for their utility.

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.

Histomorphometry in Peripheral Nerve Regeneration: Comparison of Different Axon Counting Methods.

BACKGROUND: Histomorphometry quantitatively evaluates nerve regeneration. Total myelinated fiber count (TMFC) is most accurately obtained manually across full nerve cross-sections, but most researchers opt for automated, sampled analysis. Few of the numerous techniques available have been validated. The goal of this study was to compare common histomorphometric methods (full manual [FM], sampled manual [SM], and sampled automatic [SA]) to determine their reliability and consistency. MATERIAL AND METHODS: Twenty-four rats underwent sciatic nerve (SN) repair with 20mm isografts; SNs distal to the graft were analyzed. TMFC was manually determined in each full cross-section. Counts were also extrapolated from sampled fields, both manually and automatically with ImageJ software. Myelinated fiber diameter, axon diameter, and myelin sheath thickness were measured manually in full and sampled fields; G-ratio was calculated. Repeated-measures MANOVA, Spearman correlation, and Wilcoxon signed-rank tests were performed. A systematic review of histomorphometry in rat SN repair was performed to analyze the variability of techniques in the literature. RESULTS: FM TMFC was 13,506 ± 4,217. Both sampled methods yielded significantly different TMFCs (SM:14.4 ± 13.4%, P< 0.001; SA:21.8 ± 44.7%, P = 0.037). All three methods strongly correlated with each other, especially FM and SM (rs = 0.912, P< 0.001). FM fiber diameter, axon diameter, and myelin sheath thickness did not differ from SM (P = 0.493, 0.209, and 0.331, respectively). 65% of papers used sampling; 78% utilized automated or semi-automated analysis. Software, sampling, and histomorphometric parameters varied widely. CONCLUSION: SM and SA analysis are reliable with standardized, systematic sampling. Transparency is essential to allow comparison of data; meanwhile, researchers must be cognizant of the wide variety of methodologies in the literature.

Wide posterior gluteal-thigh propeller flap for reconstruction of perineal defects.

INTRODUCTION: With increasing popularity of minimally invasive approaches to abdominoperineal resection (APR), thigh-based flaps are becoming the preferred option for reconstruction. The gluteal-thigh flap provides sufficient bulk, albeit with a high complication rate. We reevaluated the vascularization and design of the gluteal-thigh flap. The purpose of this study is to highlight the importance of the vascularization of the posterior thigh skin by the descending branch of the inferior gluteal artery (IGA) and the profunda femoris artery (PFA) perforators to design a more reliable and versatile gluteal thigh flap. This flap is indicated in selected cases in which use of vertical rectus abdominis musculocutaneous flap is not feasible. METHODS: Eleven fresh cadavers were used. The course, distribution, and diameter of IGA and PFA perforators were recorded. A wide posterior gluteal-thigh propeller flap (WPGTPF) was designed including the distance between the ischiatic tuberosity and greater trochanter; and extending it to within 8 cm of the popliteal fossa to improve flap reliability. Ten patients (mean age of 58.7 ± 10.6 years) underwent APR due to anal cancer (2) and rectal cancer (8); the approach was open in 3, laparoscopic in 6, and robotic in 1. All 10 patients received unilateral flap with a width of 12 ± 3.3 cm and surface of 405.5 ± 175.9 cm2 . RESULTS: The descending branch of the IGA was dominant in 72.7% of the specimens. In 22.7% of the specimens, the pedicle of the flap derived from the first or second PFA perforators. In one case, there was a double vascularization. Descending branch of the IGA was mapped at 46 ± 7.96 mm on the X-axis (horizontal line from the ischial tuberosity [IT] to the greater trochanter) and -12.1 ± 17.9 mm on the Y-axis (vertical line from the IT to the Medial Femoral condyle). Its average caliber measured 2.18 ± 0.3 mm. The first and second PFA perforators were located at 101.6 ± 17.9 mm and 104.5 ± 15.5 mm on the X-axis; 35.9 ± 27.1 mm and 89.2 ± 37.6 mm on the Y-axis. Their average diameters were 1.84 ± 0.41 mm and 1.48 ± 0.3 mm. In two cases, the flap was based on the first PFA perforator, the rest were on the descending branch of the IGA. Neither complete nor partial flap necrosis was observed. One patient developed coccyx osteomyelitis treated and resolved with bone debridement and one patient developed a seroma of the lateral thigh that was treated conservatively. Three patients underwent a debulking procedure by a combination of liposuction and resection to improve the gluteal symmetry. All ten flaps survived completely. CONCLUSIONS: Harvest of a wide flap that includes the PFA perforators and implementation of the propeller design increase the survival and versatility of the flap.

A meta-analysis of functional outcomes in rat sciatic nerve injury models.

INTRODUCTION: Rat sciatic nerve injury (PNR) is the most utilized model in studies on peripheral nerve regeneration. However, large animal models are increasingly favored based on the assumption that nerve regeneration in rodents achieves more favorable outcomes than in humans. The purpose of this meta-analysis was to investigate which rat PNR models are more stringent and should be used before utilizing large animal experimentation. METHODS: A PRISMA-guided meta-analysis of the English literature regarding functional outcomes in rat peripheral nerve injury models was conducted. Outcomes of five basic scenarios: (1) transected nerve/negative control, (2) transection with primary microsurgical repair, (3) isogenic/autologous grafts, (4) acellular-allogenic grafts, and (5) limb transplantation were compared to sciatic nerves without any intervention/positive control. Outcomes were compared using Sciatic Functional Index (SFI). Log-based projections were generated and evaluated using mean squared error (MSE), one-way-ANOVA, and Tukey-HSD post-hoc analysis. RESULTS: In total, 167 articles met the inclusion criteria. The earliest manifestations of motor recovery were encountered in the transection and primary repair group (p <.0005). There was a significant difference in recovery time and degree of recovery between all surgical models (p <.0005). At 24 weeks, the SFI in hindlimb transplantation group was significantly worse than all other groups (-74.07 ± 2.74, p <.0005). Autografts smaller than 10 mm recovered sooner than autografts longer than 10 mm (p = .021) and autografts recovered faster than allografts. CONCLUSION: This meta-analysis does not support the belief that neuro-regeneration is exceptional in transection models. These models remain adequate to provide translatable information and should initially be used in investigational studies.