Evaluating the benefit of virtual surgical planning on bony union rates in head and neck reconstructive surgery.

OBJECTIVES: Virtual surgical planning (VSP) has gained acceptance because of its benefits in obtaining adequate resection, achieving cephalometric accuracy, and reducing operative time. The aim of this study is to compare the rate of union between VSP and free-hand surgery (FHS), identify predictors of non-union and evaluate the difference in operative time. METHODS: Post-operative CT were retrospectively reviewed for 123 patients who underwent maxillary or mandibular reconstruction between 2014 and 2021 using either VSP or FHS. Each apposition was graded as complete, partial or non-union. The rate of union, risk difference and inter-rater reliability were calculated. The difference in operative time was assessed. Predictors of non-union were identified using logistic regression. RESULTS: A total of 326 appositions were graded (VSP n = 150; FHS n = 176). The rates of complete and partial union were higher with VSP than FHS (74.7% vs. 65.3%; 18% vs. 15.9%, respectively, p = 0.01). Non-union was found at a higher rate with FHS than with VSP (18.7% vs. 7.3%). The non-union risk difference was 11.4. FHS, major complications and apposition at the native bone were predictors of non-union (OR 2.9, p = 0.02; OR 3.4, p = 0.01; OR 2.5, p = 0.05, respectively). The mean surgical time was shorter with VSP than with FHS (265.3 vs. 381.5 min, p < 0.001). The inter-rater agreement was high (k = 0.85; ICC = 0.86). CONCLUSION: VSP demonstrated significantly higher bony union rates and shorter operative time. FHS, development of major complications and apposition with native bone correlated with non-union.

Treatment of Laryngeal Verrucous Carcinoma: 28-Year Retrospective Cohort Study and Literature Review.

Objective: Laryngeal verrucous carcinoma (LVC) comprises 1% to 4% of all laryngeal tumors. Although controversial, surgery has been the mainstay of treatment, due to concern about anaplastic transformation with radiotherapy. We aimed to study LVC patients to identify treatment patterns for primary and recurrent diseases. Study Design: Retrospective cohort study. Setting: Tertiary referral center. Methods: Patients with a pathological diagnosis of LVC treated over a 28-year period were included. Baseline demographics, and treatment outcome measures including 5-year laryngeal preservation rates (LPR), overall survival (OS), and recurrence-free survival (RFS) were included. A literature review of published studies within the same study period was also completed. Results: Thirty-two patients were included in the analysis (median age 61.5 years, 93.8% [30/32] male). Twenty-three patients had T1 disease, and 9 had T2 disease with no evidence of regional or metastatic disease. The most common presenting symptom was hoarseness (93.8%) and the majority within the glottis 81.3% (26/32). Twenty-nine patients underwent primary surgery only (28 local excisions, 1 vertical partial laryngectomy) meanwhile 3 underwent local excision with postoperative radiotherapy. LPR, OS, and RFS at 5 years were 95.8%, 90.1%, and 80.6%, respectively. Our literature review identified 23 previous studies, mostly single-institution retrospective case series. Our study was the largest Canadian study in the literature to date. Conclusion: All LVC patients were treated with primary surgery, consistent with the current literature with excellent 5-year OS and LPR. There was no consensus on the treatment of recurrent disease. Future prospective multicenter studies are warranted to further study this rare disease population.

Virtual surgical planning for maxillary reconstruction with the scapular free flap: An evaluation of a simple cutting guide design.

BACKGROUND: The study's objective is to assess the feasibility and utility of VSP for maxillary reconstruction with the scapular free flap. METHODS: An open-source VSP platform was used to create the reconstruction models and simple guides. Clinical, operative, and postoperative data were collected. RESULTS: Ten patients in the VSP cohort and 18 in the non-VSP control cohort were included in the study. There was a significant reduction in operative time (256.0 ± 69.4 vs. 448.1 ± 108.2 min, p < 0.01), tracheotomy rate (20% vs. 72%, p < 0.01), increased two-team utilization rate (80% vs. 0%, p < 0.01) and better reconstructive accuracy (7.5 ± 3.4 vs. 11.7 ± 7.6 mm, p = 0.048) for the VSP cohort. CONCLUSIONS: Maxillary reconstruction planned with an in-house open-source VSP platform and accompanied simple guides can facilitate a two-team approach, reduce operative time, and improve structural accuracy. This open-source technology has great potential to be readily applied in other institutions to improve efficiency and outcomes.

The Cynomolgus Macaque Intestinal Mycobiome Is Dominated by the Kazachstania Genus and K. pintolopesii Species.

The cynomolgus macaque, Macaca fascicularis, is a non-human primate (NHP) widely used in biomedical research as its genetics, immunology and physiology are similar to those of humans. They may also be a useful model of the intestinal microbiome as their prokaryome resembles that of humans. However, beyond the prokaryome relatively little is known about other constituents of the macaque intestinal microbiome including the mycobiome. Here, we conducted a region-by-region taxonomic survey of the cynomolgus intestinal mycobiota, from duodenum to distal colon, of sixteen captive animals of differing age (from young to old). Using a high-throughput ITS1 amplicon sequencing-based approach, the cynomolgus gut mycobiome was dominated by fungi from the Ascomycota phylum. The budding yeast genus Kazachstania was most abundant, with the thermotolerant species K. pintolopesii highly prevalent, and the predominant species in both the small and large intestines. This is in marked contrast to humans, in which the intestinal mycobiota is characterised by other fungal genera including Candida and Saccharomyces, and Candida albicans. This study provides a comprehensive insight into the fungal communities present within the captive cynomolgus gut, and for the first time identifies K. pintolopesii as a candidate primate gut commensal.

Benefits of Patient-Specific Reconstruction Plates in Mandibular Reconstruction Surgical Simulation and Resident Education.

Poorly contoured mandibular reconstruction plates are associated with postoperative complications. Recently, a technique emerged whereby preoperative patient-specific reconstructive plates (PSRP) are developed in the hopes of eliminating errors in the plate-bending process. This study's objective is to determine if reconstructions performed with PSRP are more accurate than manually contoured plates. Ten Otolaryngology residents each performed two ex vivo mandibular reconstructions, first using a PSRP followed by a manually contoured plate. Reconstruction time, CT scans, and accuracy measurements were collected. Paired Student's t-test was performed. There was a significant difference between reconstructions with PSRP and manually contoured plates in: plate-mandible distance (0.39 ± 0.21 vs. 0.75 ± 0.31 mm, p = 0.0128), inter-fibular segment gap (0.90 ± 0.32 vs. 2.24 ± 1.03 mm, p = 0.0095), mandible-fibula gap (1.02 ± 0.39 vs. 2.87 ± 2.38 mm, p = 0.0260), average reconstruction deviation (1.11 ± 0.32 vs. 1.67 ± 0.47 mm, p = 0.0228), mandibular angle width difference (5.13 ± 4.32 vs. 11.79 ± 4.27 mm, p = 0.0221), and reconstruction time (16.67 ± 4.18 vs. 33.78 ± 8.45 min, p = 0.0006). Lower plate-mandible distance has been demonstrated to correlate with decreased plate extrusion rates. Similarly, improved bony apposition promotes bony union. PSRP appears to provide a more accurate scaffold to guide the surgeons in assembling donor bone segments, which could potentially improve patient outcome and reduce surgical time. Additionally, in-house PSRP can serve as a low-cost surgical simulation tool for resident education.

Synchrony in head and neck surgery: Feasibility and outcomes of simultaneous scapular free flap reconstruction.

BACKGROUND: The scapula free flap is a versatile option in head and neck reconstruction but is less amenable to simultaneous harvest and ablation. METHODS: Retrospective series (2015-2021) of consecutive scapula flaps. Cases categorized as simultaneous versus sequential, compared for operative time, oncological and patient-reported outcomes. RESULTS: Seventy consecutive scapula free flaps were performed (n = 21 simultaneous, n = 49 sequential). Mandible reconstruction was performed in 51.0% and 61.9% of sequential and simultaneous cases, respectively; 49.0% and 38.1% addressed bony maxillary defects. Simultaneous surgery reduced operative time by 37.9% (151 min, p < 0.00001) and there were fewer tracheostomies performed (p < 0.005). Rates of positive margins and free flap compromise were equivalent (n = 1, 4.8% vs. n = 2, 4.1%). There was no difference in patient-reported outcomes. CONCLUSIONS: This series demonstrates feasibility, efficacy, and outcomes of bony scapula reconstruction of maxillofacial defects comparing simultaneous and sequential approaches. Benefits of the two-team approach are highlighted including decreased operative time.

Maxillectomy defects: Virtually comparing fibular and scapular free flap reconstructions.

BACKGROUND: This study virtually compares patient-specific fibular and scapular reconstructions for maxillectomies. METHODS: Nine maxillectomy defects were created on 10 maxillas and virtually reconstructed with patient-specific fibulas and scapulas. Reconstructions were compared for restoring midface cephalometrics, dental implantability, and pedicle length. RESULTS: Of 90 maxillectomy defects, the vertically oriented scapula provided improved orbital floor and maxillary height reconstructions (p < 0.001), albeit at the cost of dental implantability compared to the fibula (p < 0.001). In two defects crossing the midline, the fibula, allowing for more osteotomies, provided improved maxillary projection. In the remaining three defects crossing the midline, the horizontally oriented scapula was comparable to the fibula. Fibular and scapular reconstructions were amenable for dental implantation and had similar pedicle lengths, although favoring scapula in extensive defects. CONCLUSION: Fibular and scapular reconstructions of maxillectomy defects provide unique strengths. This virtual analysis can guide a goal-oriented reconstruction based on defect type and patient-specific goals.

Contributions of US Medical Schools to Primary Care (2003-2014): Determining and Predicting Who Really Goes Into Primary Care.

BACKGROUND AND OBJECTIVES: Schools of medicine in the United States may overstate the placement of their graduates in primary care. The purpose of this project was to determine the magnitude by which primary care output is overestimated by commonly used metrics and identify a more accurate method for predicting actual primary care output. METHODS: We used a retrospective cohort study with a convenience sample of graduates from US medical schools granting the MD degree. We determined the actual practicing specialty of those graduates considered primary care based on the Residency Match Method by using a variety of online sources. Analyses compared the percentage of graduates actually practicing primary care between the Residency Match Method and the Intent to Practice Primary Care Method. RESULTS: The final study population included 17,509 graduates from 20 campuses across 14 university systems widely distributed across the United States and widely varying in published ranking for producing primary care graduates. The commonly used Residency Match Method predicted a 41.2% primary care output rate. The actual primary care output rate was 22.3%. The proposed new method, the Intent to Practice Primary Care Method, predicted a 17.1% primary care output rate, which was closer to the actual primary care rate. CONCLUSIONS: A valid, reliable method of predicting primary care output is essential for workforce training and planning. Medical schools, administrators, policy makers, and popular press should adopt this new, more reliable primary care reporting method.

Perioperative ß-Blockade in Noncardiac Surgery: A Cautionary Tale of Over-reliance on Small Randomized Prospective Trials.

PURPOSE: Our aim was to analyze the current scientific literature relevant to the use of ß-adrenergic receptor antagonists for the prevention of cardiovascular morbidity and mortality in patients undergoing noncardiac surgery. METHODS: A PubMed search was conducted for the following concepts: pre- or perioperative, ß-adrenergic receptor antagonist, treatment outcome, and cardiovascular complication. Randomized clinical trials measuring the effect of ß-adrenergic blocking agents against that of placebo on cardiovascular outcomes after noncardiac surgery were included in the review. FINDINGS: Two small randomized controlled trials published in 1996 and 1999 reported associations between perioperative ß-blockade and significant reductions in long-term and 30-day cardiac mortality, respectively. These 2 studies prompted guideline changes in 2002 encouraging perioperative ß-blockade in subsets of noncardiac surgery patients. However, subsequent trials failed to validate these results. In 2008, the first large randomized controlled trial on the topic was published and found an association between perioperative ß-blockade and an increase in perioperative mortality. Furthermore, in 2011, the lead author of the 1999 study was dismissed from his academic position for scientific misconduct, casting doubt on the validity of guidelines based on his work. Existing studies are highly heterogeneous, making comparisons difficult. Current literature does not support initiating perioperative ß-blockade in noncardiac surgery patients not already receiving these medications. IMPLICATIONS: Future research on the topic should account for the influence individual genetic variation can have on outcomes and ß-blocker metabolism. Additionally, the relationship between outcomes and the ß-1 selectivity of different ß-blockers should be explored.

Measurement of airborne particle concentrations near the Sunset Crater volcano, Arizona.

Direct measurements of airborne particle mass concentrations or mass loads are often used to estimate health effects from the inhalation of resuspended contaminated soil. Airborne particle mass concentrations were measured using a personal sampler under a variety of surface-disturbing activities within different depositional environments at both volcanic and nonvolcanic sites near the Sunset Crater volcano in northern Arizona. Focused field investigations were performed at this analog site to improve the understanding of natural and human-induced processes at Yucca Mountain, Nevada. The level of surface-disturbing activity was found to be the most influential factor affecting the measured airborne particle concentrations, which increased over three orders of magnitude relative to ambient conditions. As the surface-disturbing activity level increased, the particle size distribution and the majority of airborne particle mass shifted from particles with aerodynamic diameters less than 10 mum (0.00039 in) to particles with aerodynamic diameters greater than 10 mum (0.00039 in). Under ambient conditions, above average wind speeds tended to increase airborne particle concentrations. In contrast, stronger winds tended to decrease airborne particle concentrations in the breathing zone during light and heavy surface-disturbing conditions. A slight increase in the average airborne particle concentration during ambient conditions was found above older nonvolcanic deposits, which tended to be finer grained than the Sunset Crater tephra deposits. An increased airborne particle concentration was realized when walking on an extremely fine-grained deposit, but the sensitivity of airborne particle concentrations to the resuspendible fraction of near-surface grain mass was not conclusive in the field setting when human activities disturbed the bulk of near-surface material. Although the limited sample size precluded detailed statistical analysis, the differences in airborne particle concentration over 900-y weathered volcanic and nonvolcanic deposits appeared to be potentially significant only under heavy surface disturbances.

Sinonasal undifferentiated carcinoma: case series and systematic review of the literature.

Sinonasal undifferentiated carcinoma is a rare, highly aggressive malignancy. A number of case series have been published in the literature. Most authors recommend aggressive management with a combination of surgery, radiotherapy, and chemotherapy, but the numbers in the individual studies are too small to produce a definitive opinion on the standard of care. In an attempt to determine the optimal treatment for this condition, we have undertaken a systematic review of the literature to evaluate all cases of sinonasal undifferentiated carcinoma that have been published since its initial description in 1986. Patient demographics, extent of the tumour at presentation, management, and outcomes were evaluated. We also present the experience from our institution.

Considerations for applying VARSKIN mod 2 to skin dose calculations averaged over 10 cm2.

VARSKIN Mod 2 is a DOS-based computer program that calculates the dose to skin from beta and gamma contamination either directly on skin or on material in contact with skin. The default area for calculating the dose is 1 cm2. Recently, the U.S. Nuclear Regulatory Commission issued new guidelines for calculating shallow dose equivalent from skin contamination that requires the dose be averaged over 10 cm2. VARSKIN Mod 2 was not filly designed to calculate beta or gamma dose estimates averaged over 10 cm2, even though the program allows the user to calculate doses averaged over 10 cm2. This article explains why VARSKIN Mod 2 overestimates the beta dose when applied to 10 cm2 areas, describes a manual method for correcting the overestimate, and explains how to perform reasonable gamma dose calculations averaged over 10 cm2. The article also describes upgrades underway in Varskin 3.