Examining Trends in Implantable Arterial Doppler Usage Among North American Head and Neck Microsurgeons: A Survey Study.

BACKGROUND: There are variations in implantable arterial Doppler usage for microvascular free tissue monitoring among North American surgeons. Identifying utilization trends among the microvascular community may elucidate practice patterns that may be useful in determining protocols. Furthermore, study of this information may yield novel and unique applications in other disciplines such as vascular surgery. METHODS: Electronically disseminated survey study shared with a large database of North American head and neck microsurgeons. RESULTS: Seventy four percent of respondents use the implantable arterial Doppler; 69% report use in all cases. Ninety five percent remove the Doppler by the seventh postoperative day. All respondents felt that the Doppler did not impede care progression. Any implication of flap compromise was followed with a clinical assessment in 100% of respondents. If viable, 89% would continue monitoring after clinical examination, while 11% would take the patient for exploration regardless of clinical examination. CONCLUSIONS: The efficacy of the implantable arterial Doppler has been established in the literature and is supported by the results of this study. Further investigation is required to establish a consensus on use guidelines. The implantable Doppler is more often used in conjunction with rather than substitution for clinical examination.

Forked Paramedian forehead flap combined with nasolabial flap for pre-radiation coverage of exposed maxilla in the Total Rhinectomy patient.

Total rhinectomy is ontologically necessary for large and locally invasive carcinomas of the nasal cavity owing to the complex three-dimensional structure of the nose. Reconstruction options include singular or combined options of local tissue rearrangement, free flap reconstruction, and prosthetic reconstruction which may be delayed in the setting of post-ablative radiation therapy. If significant bony exposure is present prior to radiation, there is a substantial risk of osteoradionecrosis and the ensuing sequalae. In these cases, coverage of the bony defect may be advantageous prior to radiation and final reconstructive treatment. We present a case of a total rhinectomy defect for squamous cell carcinoma in a patient who had significant bony exposure prior to radiation which was resurfaced with a combined forked paramedian flap and nasolabial flap. The patient went on to be treated with a full course of radiation and had planned for a post-treatment nasal prosthesis.

Alternative Abdominal Wall Plication Techniques: A Review of Current Literature.

Abdominoplasty is one of the most common procedures performed in plastic surgery. By removing redundant skin and fat tissue, body contouring narrows the waist and achieves a naturally flattened appearance. To achieve this, one technique frequently utilized is plication of the abdominal rectus sheath. Although abdominal wall plication is commonly performed during abdominoplasty, there is a lack of consensus regarding which plication method provides the best outcomes. Each variation addresses some of the common intraoperative and postoperative complications of abdominoplasty. These include extended operating time, rupture of the plication, epigastric bulging, and patient postoperative dissatisfaction. Many plication techniques have been described in the literature, but no single technique has been adopted by plastic surgeons as the gold standard. Here we present a narrative comparison of current published literature reporting novel or modified abdominoplasty plication techniques. This includes diagrams of each procedure, sutures utilized, and key concepts of each plication technique. Discussion regarding how these modifications change operating time, alter epigastric bulging, and improve the ability to narrow the waist is provided. The purpose of this paper is to provide a concise source document for plastic surgeons to reference when choosing a plication method to use during abdominoplasty.

Genomic correlates for migratory direction in a free-ranging cervid.

Animal migrations are some of the most ubiquitous and one of the most threatened ecological processes globally. A wide range of migratory behaviours occur in nature, and this behaviour is not uniform among and within species, where even individuals in the same population can exhibit differences. While the environment largely drives migratory behaviour, it is necessary to understand the genetic mechanisms influencing migration to elucidate the potential of migratory species to cope with novel conditions and adapt to environmental change. In this study, we identified genes associated with a migratory trait by undertaking pooled genome-wide scans on a natural population of migrating mule deer. We identified genomic regions associated with variation in migratory direction, including FITM1, a gene linked to the formation of lipids, and DPPA3, a gene linked to epigenetic modifications of the maternal line. Such a genetic basis for a migratory trait contributes to the adaptive potential of the species and might affect the flexibility of individuals to change their behaviour in the face of changes in their environment.

Nonreplantable Total Scalp Avulsion Reconstruction with Acellular Biologic Matrix and Long-Term Outcome.

ABSTRACT: Total scalp avulsion is a significant injury typically occurring as a result of industrial accidents involving high-speed rotary machines. Although ideal, scalp replantation is uncommon secondary to the nature of the injury and lack of viable microvas-cular anastomosis targets. Therefore, these defects are often reconstructed with microvascular free tissue transfer, with or without skin grafting. We present a unique case of a patient with total scalp avulsion achieving complete, stable skin coverage over partially intact periosteum using only spare parts of the amputated scalp as a temporary full-thickness graft and porcine urinary bladder matrix, thus, avoiding significant donor site morbidity or extensive surgery. At 4 years postoperative, the scalp coverage remains stable.

Management of Mandible Angle Fractures With a Right Angle Drill: Description of Technique.

ABSTRACT: Management of mandible angle fractures can be challenging within the confines of the oral cavity where the use of linear instruments may result in structural weakness or malalignment secondary to improper placement. A right angle drill can facilitate a more ergonomic approach, with direct perpendicular placement of the instrument over the angle fracture. In addition, local soft tissue strain is minimized, and the need for a transcutaneous exposure can be avoided for additional plate placement. The right angle drill technique is simple, reproducible, and can be easily incorporated into routine mandible angle fracture management.

Revisiting the Cervicodeltopectoral Flap for Reconstruction of Cutaneous Head and Neck Defects: Technique Description and Clinical Presentation Correlates.

STUDY DESIGN: Technique Description with clinical presentation Correlates. PURPOSE: Revisit and discuss the advantages of the cervicodeltopectoral flap (CDP) as an alternative to microvascular reconstruction for head and neck cutaneous defects. METHODS: Retrospective chart review was performed on 2 patients with prior large cutaneous facial defects after tumor resection followed by cervicodeltopectoral flap reconstruction. These cases were performed at a single institution. The tumor resections, flap reconstructions, and postoperative management were led by the listed senior author (SPK). RESULTS: A 78-year-old (Clinical presentation 1) and 62-year-old (Clinical presentation 2) were evaluated for large nonmelanoma skin cancers of the face. Due to significant comorbidities, neither patient was an ideal candidate for microsurgical reconstruction. In both cases, lesion resection and CDP flap reconstruction was performed. The reconstruction allowed for successful coverage without significant donor site morbidity for each patient. CONCLUSIONS: The authors propose the addition of the CDP flap to the armamentarium of the head and neck reconstructive surgeon as a safe and reliable alternative to microvascular reconstruction.

Reconstruction of Congenital Arhinia With Stereolithographic Modeling: Case Correlate and Literature Review.

Complete congenital arhinia is a rare defect of embryogenesis leading to the absence of the external nose and airway. We report our novel multistaged reconstructive approach and literature review. Nasal methyl methacrylate prosthesis was created from a stereolithographic model for use as a temporary prosthesis and tissue expander. Lefort 1 with cannulization was utilized for midface advancement and airway formation. External framework was reconstructed with bilateral conchal bowl cartilage and rib osteocartilagenous grafts. Patient was pleased with the aesthetics and had safe decannulation with the ability to breathe through the nose and airway.

Blindness Secondary to Orbital Giant Cell Granuloma Mass-Effect in Noonan Syndrome With Return of Vision Following Surgical Decompression.

ABSTRACT: Noonan syndrome is a rare, autosomal dominant disorder encompassing multiple congenital defects, as well as association with solid tumor and lesion development. The authors present a 26-year-old female with known Noonan syndrome and ongoing complaint of worsening unilateral vision, progressing to vision loss due to lesion mass effect. Decompressive surgery was performed, restoring patient's vision to baseline immediately postoperative. The lesion was confirmed to be giant cell granuloma. In this paper we discuss the unique presentation of vision loss due to orbital giant cell granuloma in Noonan syndrome with postoperative return of vision; the importance of a multi-disciplinary team evaluation, thorough preoperative clinical and image-based work up, intraoperative findings, postoperative outcome, and complexity of definitive management.

Common Carotid-to-Internal Jugular Arteriovenous Loop for Single-Stage Microsurgical Reconstruction in the Radiated Vessel-Depleted Neck.

ABSTRACT: Management of head and neck defects in a radiated field can be quite challenging owing to the dearth of vasculature and significant degree of post-radiation fibrosis. In this setting, arteriovenous (AV) loop vascular grafts can bypass nonviable local vessels to provide viable and reliable inflow and outflow vessels for free tissue transfer in an otherwise hostile environment. Prior reports of the Corlett loop utilizing a cephalic vein transposition has been described however a common carotid-to-internal jugular AV loop has not been recently reported. Three patients underwent carotid artery to internal jugular vein AV loop creation to facilitate free-flap reconstruction secondary to radiation-induced vessel depletion. The specific technique described utilizes the saphenous vein as a donor and spares the cephalic vein for the possibility of flap complication. All three cases resulted in successful reconstruction, maintaining healthy tissue, vascular flow, and flap viability at all follow-up intervals. In our experience, vascular augmentation via AV loop formation provides reliable vascular inflow and outflow in the vessel-depleted neck to facilitate microvascular reconstruction. Sparing the cephalic vein yields an additional salvage mechanism in the event of venous congestion.

Potential Complications With Cryopreserved Cadaveric Veins in Arteriovenous Loop Formation for Head and Neck Microvascular Reconstruction.

ABSTRACT: Vessel depletion in the head and neck from radiation or previous surgical intervention adds to the operative complexity by limiting reconstructive options. Arteriovenous (AV) loop vascular grafts provide a conduit to bypass these nonviable local vessels to provide adequate blood flow. In certain situations, autologous donor vascular options are deficient or not readily available for creation of the AV loop. Cadaveric vein grafts provide an alternative option in these circumstances, but the efficacy and safety has not yet been delineated. In this study we discuss our experience utilizing cryopreserved cadaveric vein grafts for AV loop creation in head and neck reconstruction. In our initial cohort we aim to elucidate potential challenges and complications associated with the use of cadaveric vein grafts.

Reconstruction of the Mandibular Condyle.

The mandibular condyle is an integral structure in the temporomandibular joint (TMJ) serving not only as the hinge point for mandibular opening, but also facilitating mandibular growth and contributing to facial aesthetics. Significant compromise of the TMJ can be debilitating functionally, psychologically, and aesthetically. Reconstruction of the mandibular condyle is rarely straightforward. Multiple considerations must be accounted for when preparing for condylar reconstruction such as ensuring eradication of all chronically diseased or infected bone, proving clear oncologic margins following tumor resection, or achieving stability of the surrounding architecture in the setting of a traumatic injury. Today, there is not one single gold-standard reconstructive method or material; ongoing investigation and innovation continue to improve and transform condylar reconstruction. Herein, we review methods of condylar reconstruction focusing on autologous and alloplastic materials, surgical techniques, and recent technological advances.

Cannabis Abuse or Dependence and Post-operative Outcomes After Appendectomy and Cholecystectomy.

BACKGROUND: Though cannabis is gaining broader acceptance among society and a noted increase in legalization, little is known regarding its impact on post-operative outcomes. We conducted this study to quantify the relationship between cannabis abuse or dependence (CbAD) on post-operative outcomes after cholecystectomy and appendectomy. METHODS: Using the 2013-2015 Nationwide Readmissions Database, we identified discharges associated with cholecystectomy or appendectomy from January 2013-August 2015. Patients were grouped by CbAD history. The primary outcomes were length of stay, serious adverse events, home discharge, and 30-day readmission. Propensity-score matching was used to account for differences between groups and all statistics accounted for the matched sample. RESULTS: The final sample included 3288 patients with a CbAD history matched 1:1 to patients without a CbAD history (total sample = 6576). After matching, acceptable balance was achieved in clinical characteristics between groups. In the cholecystectomy cohort (n = 1707 pairs), CbAD patients had longer hospitalizations (3.5 versus 3.2 d, P 0.003) and similar rates of serious adverse events (6.1 versus 4.8, P 0.092), home discharge (96.1 vs 96.2, P 0.855), and readmission (8.3 versus 6.9, P 0.137). In the appendectomy cohort (n = 1581 pairs), CbAD patients had longer hospital stays (2.7 versus 2.5 d, P 0.024); more frequent serious adverse events (5.0 versus 3.5, P 0.041); and similar home discharge (96.8 vs 97.3, P 0.404) and readmission (5.4 versus 5.1, P 0.639) rates. CONCLUSIONS: Patients with a history of CbAD in the cholecystectomy and appendectomy cohorts had slightly longer hospital stays, and patients with a history of CbAD in the appendectomy group displayed a slight increase in adverse events, but otherwise similar clinical outcomes without clinically significant increases in complications compared to patients without this history.

Targeted muscle reinnervation following external hemipelvectomy or hip disarticulation: An anatomic description of technique and clinical case correlates.

BACKGROUND: Targeted muscle reinnervation (TMR) has been shown to decrease or prevent neuropathic pain, including phantom and residual limb pain, after extremity amputation. Currently, a paucity of data and lack of anatomical description exists regarding TMR in the setting of hemipelvectomy and/or hip disarticulations. We elaborate on the technique of TMR, illustrated through cadaveric and clinical correlates. METHODS: Cadaveric dissections of multiple transpelvic exposures were performed. The major mixed motor and sensory nerve branches were identified, dissected, and tagged. Amputated peripheral nerves were transferred to identified, labeled target motor nerves via direct end-to-end nerve coaptations per traditional TMR technique. A retrospective review was completed by our multi-institutional teams to include examples of clinical correlates for TMR performed in the setting of hemipelvectomies and hip disarticulations. RESULTS: A total of 12 TMR hemipelvectomy/hip disarticulation cases were performed over a 2 to 3-year period (2018-2020). Of these 12 cases, 9 were oncologic in nature, 2 were secondary to traumatic injury, and 1 was a failed limb salvage in the setting of chronic refractory osteomyelitis of the femoral shaft. CONCLUSIONS: This manuscript outlines the technical considerations for TMR in the setting of hemipelvectomy and hip disarticulation with supporting clinical case correlates.

Heritability Estimates of Antler and Body Traits in White-Tailed Deer (Odocoileus virginianus) From Genomic-Relatedness Matrices.

Estimating heritability (h2) is required to predict the response to selection and is useful in species that are managed or farmed using trait information. Estimating h2 in free-ranging populations is challenging due to the need for pedigrees; genomic-relatedness matrices (GRMs) circumvent this need and can be implemented in nearly any system where phenotypic and genome-wide single-nucleotide polymorphism (SNP) data are available. We estimated the heritability of 5 body and 3 antler traits in a free-ranging population of white-tailed deer (Odocoileus virginianus) on Anticosti Island, Quebec, Canada. We generated classic and robust GRMs from >10,000 SNPs: hind foot length, dressed body mass, and peroneus muscle mass had high h2 values of 0.62, 0.44, and 0.55, respectively. Heritability in male-only antler features ranged from 0.07 to 0.33. We explored the influence of filtering by minor allele frequency and data completion on h2: GRMs derived from fewer SNPs had reduced h2 estimates and the relatedness coefficients significantly deviated from those generated with more SNPs. As a corollary, we discussed limitations to the application of GRMs in the wild, notably how skewed GRMs, specifically many unrelated individuals, can increase variance around h2 estimates. This is the first study to estimate h2 on a free-ranging population of white-tailed deer and should be informative for breeding designs and management as these traits could respond to selection.

Geographic Variation in Breast Reconstruction Modality Use Among Women Undergoing Mastectomy.

PURPOSE: Despite changes in legislation and an increase in public awareness, many women may not have access to the various types of breast reconstruction. The purpose of this study was to evaluate variation in reconstructive modality at the health service area (HSA) level and its relationship to the plastic surgeon workforce in the same area. METHODS: Using the Arkansas, California, Florida, Nebraska, and New York state inpatient databases, we conducted a cross-sectional study of adult women undergoing mastectomy for cancer from 2009 to 2012. The primary outcomes were receipt of reconstruction and the reconstructive modality (autologous tissue versus implant) used. All data were aggregated to the HSA level and augmented with plastic surgeon workforce data. Correlation coefficients were calculated for the relationship between the outcomes and workforce. RESULTS: The final sample included 67,984 women treated across 103 HSAs. The average patient was 58.5 years, had private insurance (53.5%), and underwent unilateral mastectomy for invasive cancer. At the HSA level, the median immediate breast reconstruction rate was 25.0% and varied widely (interquartile range, 43.2%). In areas where reconstruction was performed, the median autologous (10.2%) and free tissue (0.4%) reconstruction rates were low, with more than 30% of HSAs never using autologous tissue. There was a direct correlation between an HSA's plastic surgeon density and autologous reconstruction rate (r = 0.81, P < 0.001). CONCLUSIONS: Despite efforts to remove financial barriers and improve patients' awareness, accessibility to various modalities of reconstruction is inadequate for many women. Efforts are needed to improve the availability of more comprehensive breast reconstruction care.

Structural Basis for Sialoglycan Binding by the Streptococcus sanguinis SrpA Adhesin.

Streptococcus sanguinisis a leading cause of infective endocarditis, a life-threatening infection of the cardiovascular system. An important interaction in the pathogenesis of infective endocarditis is attachment of the organisms to host platelets.S. sanguinisexpresses a serine-rich repeat adhesin, SrpA, similar in sequence to platelet-binding adhesins associated with increased virulence in this disease. In this study, we determined the first crystal structure of the putative binding region of SrpA (SrpABR) both unliganded and in complex with a synthetic disaccharide ligand at 1.8 and 2.0 Å resolution, respectively. We identified a conserved Thr-Arg motif that orients the sialic acid moiety and is required for binding to platelet monolayers. Furthermore, we propose that sequence insertions in closely related family members contribute to the modulation of structural and functional properties, including the quaternary structure, the tertiary structure, and the ligand-binding site.

Kinetic and structural mechanisms of (5'S)-8,5'-cyclo-2'-deoxyguanosine-induced dna replication stalling.

The (5'S)-8,5'-cyclo-2'-deoxyguanosine (S-cdG) lesion is produced from reactions of DNA with hydroxyl radicals generated from ionizing radiation or endogenous oxidative metabolisms. An elevated level of S-cdG has been detected in Xeroderma pigmentosum, Cockayne syndrome, breast cancer patients, and aged mice. S-dG blocks DNA replication and transcription in vitro and in human cells and produces mutant replication and transcription products in vitro and in vivo. Major cellular protection against S-dG includes nucleotide excision repair and translesion DNA synthesis. We used kinetic and crystallographic approaches to elucidate the molecular mechanisms of S-cdG-induced DNA replication stalling using model B-family Sulfolobus solfataricus P2 DNA polymerase B1 (Dpo1) and Y-family S. solfataricus P2 DNA polymerase IV (Dpo4). Dpo1 and Dpo4 inefficiently bypassed S-cdG with dCTP preferably incorporated and dTTP (for Dpo4) or dATP (for Dpo1) misincorporated. Pre-steady-state kinetics and crystallographic data mechanistically explained the low-efficiency bypass. For Dpo1, S-cdG attenuated Kd,dNTP,app and kpol. For Dpo4, the S-cdG-adducted duplex caused a 6-fold decrease in Dpo4:DNA binding affinity and significantly reduced the concentration of the productive Dpo4:DNA:dCTP complex. Consistent with the inefficient bypass, crystal structures of Dpo4:DNA(S-cdG):dCTP (error-free) and Dpo4:DNA(S-cdG):dTTP (error-prone) complexes were catalytically incompetent. In the Dpo4:DNA(S-cdG):dTTP structure, S-cdG induced a loop structure and caused an unusual 5'-template base clustering at the active site, providing the first structural evidence of the previously suggested template loop structure that can be induced by a cyclopurine lesion. Together, our results provided mechanistic insights into S-cdG-induced DNA replication stalling.

Type III effector NleH2 from Escherichia coli O157:H7 str. Sakai features an atypical protein kinase domain.

The crystal structure of a C-terminal domain of enterohemorrhagic Escherichia coli type III effector NleH2 has been determined to 2.6 Å resolution. The structure resembles those of protein kinases featuring the catalytic, activation, and glycine-rich loop motifs and ATP-binding site. The position of helix αC and the lack of a conserved arginine within an equivalent HRD motif suggested that the NleH2 kinase domain's active conformation might not require phosphorylation. The activation segment markedly contributed to the dimerization interface of NleH2, which can also accommodate the NleH1-NleH2 heterodimer. The C-terminal PDZ-binding motif of NleH2 provided bases for interaction with host proteins.