A meta-analysis of perfusion parameters affecting weight gain in ex vivo perfusion.

BACKGROUND: Ex vivo machine perfusion (EVMP) has been established to extend viability of donor organs. However, EVMP protocols are inconsistent. We hypothesize that there is a significant relationship between specific parameters during EVMP and perfusion outcomes. METHODS: A meta-analysis of literature was conducted in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) Statement. The search encompassed articles published before July 25, 2023. PubMed, Embase, and CENTRAL databases were screened using search terms "ex-vivo," "ex-situ," "machine," and "perfusion." Weight gain, an indicator of organ viability, was chosen to compare outcomes. Extracted variables included perfused organ, warm and cold ischemia time before perfusion, perfusion duration, perfusate flow, pressure, temperature, perfusate composition (presence of cellular or acellular oxygen carrier, colloids, and other supplements) and percent weight change. Data were analyzed using SPSS statistical software. RESULTS: Overall, 44 articles were included. Red blood cell-based perfusates resulted in significantly lower weight gain compared to acellular perfusates without oxygen carriers (11.3% vs. 27.0%, p < 0.001). Hemoglobin-based oxygen carriers resulted in significantly lower weight gain compared to acellular perfusates (16.5% vs. 27%, p = 0.006). Normothermic perfusion led to the least weight gain (14.6%), significantly different from hypothermic (24.3%) and subnormothermic (25.0%) conditions (p < 0.001), with no significant difference between hypothermic and subnormothermic groups (24.3% vs. 25.0%, p = 0.952). There was a positive correlation between flow rate and weight gain (ß = 13.1, R = 0.390, p < 0.001). CONCLUSIONS: Oxygen carriers, low flow rates, and normothermic perfusate temperature appear to improve outcomes in EVMP. These findings offer opportunities for improving organ transplantation outcomes.

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.

Determining Chin Dimensions for Feminizing Genioplasty: An Anatomic Study.

BACKGROUND: Feminizing genioplasty warrants chin modification to achieve feminine characteristics. This study compared female and male facial skeletal dimensions and shape to guide feminizing genioplasty. METHODS: Skulls stored at the Cleveland Museum of Natural History were analyzed. Sex, age, and race were documented. Heights and widths of the face and chin were measured, normalized, and compared. RESULTS: Forty-three male (43.58±12.52-y-old) and 43 female (40.48±12.04-y-old) skulls were included. Within each group, 25 skulls were of African American (AA) origin and 18 were of Caucasian (C) origin. Absolute chin heights were larger in AA and C males compared with females (P<0.05). After normalization to lower facial height, there was a trend toward greater chin height in AA males compared with females (P=0.07). Parasagittal chin width in AA males was significantly larger than AA females (P=0.0006). Interforaminal chin width in C males trended toward being significantly larger than females (P=0.08). Following normalization of chin widths, no significant sex-based differences were noted for AA skulls except for the interforaminal/intergonial ratio, which was smaller in AA males (P=0.04). For C skulls, most normalized ratios were significantly smaller in males (P<0.05). C females had wider angles at the point of maximum chin projection (P=0.007) and wider symphyseal inclinations (P<0.0001). These differences were not present in AA skulls (P>0.05). Regardless of race, male chins appeared square, whereas female chins were round. CONCLUSIONS: While chin width reduction is not needed for most patients, height reduction could be considered. Chin contouring is the most central component of feminizing genioplasty.

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.

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.

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.

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.

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.

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.

Extended ex vivo normothermic perfusion for preservation of vascularized composite allografts.

Ischemia and reperfusion injury remains a significant limiting factor for the successful revascularization of amputated extremities. Ex vivo normothermic perfusion is a novel approach to prolong the viability of the amputated limbs by maintaining physiologic cellular metabolism. This study aimed to evaluate the outcomes of extended ex vivo normothermic limb perfusion (EVNLP) in preserving the viability of amputated limbs for over 24 hours. A total of 10 porcine forelimbs underwent EVNLP. Limbs were perfused using an oxygenated colloid solution at 38°C containing washed RBCs. Five forelimbs (Group A) were perfused for 12 hours and the following 5 (Group B) until the vascular resistance increased. Contralateral forelimbs in each group were preserved at 4°C as a cold storage control group. Limb viability was compared between the 2 groups through assessment of muscle contractility, compartment pressure, tissue oxygen saturation, indocyanine green (ICG) angiography and thermography. EVNLP was performed for 12 hours in group A and up to 44 hours (24-44 hours) in group B. The final weight increase (-1.28 ± 8.59% vs. 7.28 ± 15.05%, P = .548) and compartment pressure (16.50 ± 8.60 vs. 24.00 ± 9.10) (P = .151) were not significantly different between the two groups. Final myoglobin and CK mean values in group A and B were: 875.0 ± 325.8 ng/mL (A) versus 1133.8 ± 537.7 ng/mL (B) (P = .056) and 53 344.0 ± 16 603.0 U/L versus 64 333.3 ± 32 481.8 U/L (P = .286). Tissue oxygen saturation was stable until the end in both groups. Infra-red thermography and ICG-angiography detected variations of peripheral limb perfusion. Our results suggest that extended normothermic preservation of amputated limbs is feasible and that the outcomes of prolonged EVNLP (>24 hours) are not significantly different from short EVNLP (12 hours).

Alveolar Rhabdomyosarcoma Following Mandibular Distraction Osteogenesis.

The authors present a rare case of anaplastic alveolar rhabdomyosarcoma (ARMS) occurring after Mandibular Distraction Osteogenesis. A 16-month-old male presented with a rapidly enlarging left lower jaw mass after removal of mandibular distractors placed shortly after birth for Pierre Robin Sequence and severe obstructive sleep apnea. Incisional biopsy of the mass revealed ARMS with anaplastic features. Although ARMS is an extremely rare entity, craniofacial surgeons should have a low threshold for seeking further diagnostic modalities of a growing mass postmandibular distraction.

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.