Abnormal p53 Immunohistochemical Patterns Are Associated with Regional Lymph Node Metastasis in Oral Cavity Squamous Cell Carcinoma at Time of Surgery.

INTRODUCTION: Sixty to eighty percent of oral cavity invasive squamous cell carcinoma (OSCC) demonstrate molecular alterations in TP53. The presence of TP53 mutations in multiple organ systems has been associated with a more aggressive clinical course. The purpose of this study was to classify OSCC into p53 wild-type OSCC and p53-abnormal OSCC using p53 immunohistochemistry and to determine if abnormal p53 status correlates with higher risk of lymph node metastasis at the time of surgery. MATERIALS AND METHODS: A total of 101 patients with OSCC resection and cervical lymph node dissection were identified. p53 immunohistochemistry was performed for all cases and scored into p53 wild-type (p53-HPV: mid-epithelial/basal sparing, markedly reduced [null-like]/basal sparing; p53-conventional: scattered basal, patchy basal/parabasal) and p53-abnormal (overexpression basal/parabasal only, overexpression basal/parabasal to diffuse, null, cytoplasmic) patterns. p16 immunohistochemistry and high-risk HPV RNA in situ hybridization were used to confirm the HPV status in cases showing mid-epithelial/basal sparing or markedly reduced (null-like)/basal sparing pattern. Logistic regression analysis was performed to investigate the association of p53 status, tumor size, depth of invasion, and pT stage against lymph node status. RESULTS: We identified 22 cases with p53 wild-type patterns (16 p53-conventional, 6 p53-HPV) and 79 cases with p53-abnormal patterns. Two of 22 p53 wild-type cases had positive lymph nodes (1 p53-conventional, 1 p53-HPV), while 40 of 79 p53-abnormal cases had positive lymph nodes (p<0.001). Multivariate analysis showed that p53-abnormal pattern was an independent risk factor associated with positive node(s) with an odds ratio of 8.12 (95% CI, 2.10-53.78; p=0.008). CONCLUSION: p53-abnormal OSCCs were significantly more likely to be associated with positive lymph node status compared to p53 wild-type OSCCs at time of surgery. Further investigation with long-term follow-up is required to determine its clinical application prior to surgery planning.

Identification of a serum-based microRNA signature that detects recurrent oral squamous cell carcinoma before it is clinically evident.

BACKGROUND: Survival rates for oral squamous cell carcinoma (OSCC) have remained poor for decades, a fact largely attributable to late-stage diagnoses and high recurrence rates. We report analysis of serum miRNA expression in samples from patients with high-risk oral lesions (HRL, including OSCC/carcinoma in situ lesions) and healthy non-cancer controls, with the aim of non-invasively detecting primary or recurrent disease before it is clinically evident. METHODS: Discovery, test, and validation sets were defined from a total of 468 serum samples (305 HRL and 163 control samples). Samples were analysed using multiple qRT-PCR platforms. RESULTS: A two-miRNA classifier comprised of miR-125b-5p and miR-342-3p was defined following discovery and test analyses. Analysis in an independent validation cohort reported sensitivity and specificity of ~74% for this classifier. Significantly, when this classifier was applied to serial serum samples taken from patients both before treatment and during post-treatment surveillance, it identified recurrence an average of 15 months prior to clinical presentation. CONCLUSIONS: These results indicate this serum miRNA classifier is effective as a simple, non-invasive monitoring tool for earlier detection of recurrent disease when lesions are typically smaller and amenable to a wider array of treatment options to improve survival.

Prognostic value and cost benefit of HPV testing for oropharyngeal cancer patients.

OBJECTIVES: High-risk human papillomavirus (HR-HPV) can cause oropharyngeal squamous cell carcinoma (OpSCC). The revised 8th edition of the AJCC Staging Manual now stages OpSCC by incorporating p16 immunohistochemistry (IHC), the surrogate marker for HPV status. This study assessed the prognostic values of p16 and HPV markers. METHODS: We identified 244 OpSCC patients diagnosed between 2000 and 2008 from the British Columbia Cancer Registry with enough tissue to conduct experiments. Formalin-fixed, paraffin-embedded tissue sections were stained for p16 IHC, RNA in situ hybridization (ISH) HPV 16 and 18, and DNA ISH HR-HPV. Electronic charts were reviewed to collect clinical and outcome data. Combined positive RNA and/or DNA ISH was used to denote HPV status. RESULTS: Human papillomavirus was positive among 77.9% of samples. Using HPV as the benchmark, p16 IHC had high sensitivity (90.5%), but low specificity (68.5%). Distinct subgroups of patients were identified by sequential separation of p16 then HPV status. Among both p16-positive and p16-negative groups, HPV-positive patients were younger, more males, and had better clinical outcomes, especially 5-year overall survival. We further evaluated the technical costs associated with HPV testing. CONCLUSION: Human papillomavirus is more prognostic than p16 for OpSCC. Clinical laboratories can adopt HPV RNA ISH for routine analysis.

Combined chemoradiotherapy showed improved outcome with early-stage HPV-positive oropharyngeal cancers.

BACKGROUND: The revised 8th Edition American Joint Committee on Cancer (AJCC) Head and Neck Staging Manual distinguishes HPV-mediated from non-HPV-mediated oropharyngeal cancer (OpSCC). The objective was to analyze OpSCC treatment modalities and outcomes. METHODS: A retrospective study of OpSCC patients treated with radiotherapy or chemoradiotherapy between January 1st, 2000, and December 31st, 2008, as identified from the BC Cancer Registry. All patients received treatment at cancer clinics and had at least 5 years follow-up post-treatment. A total of 1259 OpSCC patients were identified. After initial chart reviews, 288 patients were excluded from further analysis and the majority (n = 198) was due to not receiving curative treatment. Based on the availability of formalin-fixed, paraffin-embedded (FFPE) tissue, patients were divided into two cohorts: Study Cohort (FFPE available, n = 244) and General Cohort (FFPE unavailable, n = 727). The Study Cohort was restaged according to AJCC 8th Edition based on p16 immunohistochemistry status. Kaplan-Meier analysis was used to estimate the 5-year overall survival (OS), disease-specific survival (DSS), and locoregional recurrence-free survival (LFS). RESULTS: Among 971 patients, OpSCC age-adjusted incidence rate was observed to have increased from 2.1 to 3.5 per 100,000 between 2000 and 2008. The General Cohort was relatively older than the Study Cohort (60.1 ± 10.5 vs. 57.3 ± 9.4), but both cohorts were predominantly males (78.3% vs. 76.2%). Amongst the Study Cohort, 77.5% were p16-positive, of whom 98.4% were down staged in the 8th Edition. These early-stage patients showed OS improvement for those treated with chemoradiation, compared to radiation alone (85.8% vs. 73.1%, p = 0.05). CONCLUSIONS: OpSCC incidence is increasing in BC. The addition of chemotherapy to radiotherapy may portend a benefit in OS even for early-stage p16-positive OpSCC. Additional research is necessary to assess the safety of treatment de-escalation even among early-stage disease.

Treatment de-escalation for HPV-associated oropharyngeal squamous cell carcinoma with radiotherapy vs. trans-oral surgery (ORATOR2): study protocol for a randomized phase II trial.

BACKGROUND: Patients with human papillomavirus-positive (HPV+) oropharyngeal squamous cell carcinoma (OPC) have substantially better treatment response and overall survival (OS) than patients with HPV-negative disease. Treatment options for HPV+ OPC can involve either a primary radiotherapy (RT) approach (± concomitant chemotherapy) or a primary surgical approach (± adjuvant radiation) with transoral surgery (TOS). These two treatment paradigms have different spectrums of toxicity. The goals of this study are to assess the OS of two de-escalation approaches (primary radiotherapy and primary TOS) compared to historical control, and to compare survival, toxicity and quality of life (QOL) profiles between the two approaches. METHODS: This is a multicenter phase II study randomizing one hundred and forty patients with T1-2 N0-2 HPV+ OPC in a 1:1 ratio between de-escalated primary radiotherapy (60 Gy) ± concomitant chemotherapy and TOS ± de-escalated adjuvant radiotherapy (50-60 Gy based on risk factors). Patients will be stratified based on smoking status (< 10 vs. ≥ 10 pack-years). The primary endpoint is OS of each arm compared to historical control; we hypothesize that a 2-year OS of 85% or greater will be achieved. Secondary endpoints include progression free survival, QOL and toxicity. DISCUSSION: This study will provide an assessment of two de-escalation approaches to the treatment of HPV+ OPC on oncologic outcomes, QOL and toxicity. Results will inform the design of future definitive phase III trials. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT03210103. Date of registration: July 6, 2017, Current version: 1.3 on March 15, 2019.

Outcomes of free flap reconstructions with near-infrared spectroscopy (NIRS) monitoring: A systematic review.

BACKGROUND: Free flap failure or vascular compromise remains a dreadful complication of microvascular free tissue transfer. Near-infrared spectroscopy (NIRS) is a novel technique for free flap monitoring that has the propensity for early detection of vascular compromise when compared to the current gold standard, clinical monitoring (CM). The objective of this review is to evaluate the efficacy of a NIRS system in the postoperative monitoring of free flaps and its effect on flap salvage. METHODS: A comprehensive literature review was performed including English-language articles evaluating the use of NIRS in free flap monitoring. MEDLINE, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), OVID, and Web of Science were searched upto December 2017. RESULTS: A total of 590 articles were identified, and 10 articles were included for analysis. Overall, flaps with vascular compromise monitored with NIRS had a significantly higher salvage rate of 89% compared with a salvage rate of 50% in the flaps monitored by CM alone (p < .01). Partial loss occurred in 15% of the successful salvages in the NIRS group versus 80% with CM alone (p < .01). Detection of vascular compromise by NIRS preceded clinical signs on average by 82 ± 49 min. NIRS was accurate in detecting compromised flaps with a low false-positive and false-negative rate. CONCLUSION: Despite lack of robust data, NIRS has the potential to be an objective, accurate, and continuous postoperative free flap monitoring technique with a greater flap salvage rate than CM alone.

Radiotherapy versus transoral robotic surgery and neck dissection for oropharyngeal squamous cell carcinoma (ORATOR): an open-label, phase 2, randomised trial.

BACKGROUND: Transoral robotic surgery (TORS) with concurrent neck dissection has supplanted radiotherapy in the USA as the most common treatment for oropharyngeal squamous cell carcinoma (OPSCC), yet no randomised trials have compared these modalities. We aimed to evaluate differences in quality of life (QOL) 1 year after treatment. METHODS: The ORATOR trial was an investigator-initiated, multicentre, international, open-label, parallel-group, phase 2, randomised study. Patients were enrolled at six hospitals in Canada and Australia. We randomly assigned (1:1) patients aged 18 years or older, with Eastern Cooperative Oncology Group scores of 0-2, and with T1-T2, N0-2 (≤4 cm) OPSCC tumour types to radiotherapy (70 Gy, with chemotherapy if N1-2) or TORS plus neck dissection (with or without adjuvant chemoradiotherapy, based on pathology). Following stratification by p16 status, patients were randomly assigned using a computer-generated randomisation list with permuted blocks of four. The primary endpoint was swallowing-related QOL at 1 year as established using the MD Anderson Dysphagia Inventory (MDADI) score, powered to detect a 10-point improvement (a clinically meaningful change) in the TORS plus neck dissection group. All analyses were done by intention to treat. This study is registered with ClinicalTrials.gov (NCT01590355) and is active, but not currently recruiting. FINDINGS: 68 patients were randomly assigned (34 per group) between Aug 10, 2012, and June 9, 2017. Median follow-up was 25 months (IQR 20-33) for the radiotherapy group and 29 months (23-43) for the TORS plus neck dissection group. MDADI total scores at 1 year were mean 86·9 (SD 11·4) in the radiotherapy group versus 80·1 (13·0) in the TORS plus neck dissection group (p=0·042). There were more cases of neutropenia (six [18%] of 34 patients vs none of 34), hearing loss (13 [38%] vs five [15%]), and tinnitus (12 [35%] vs two [6%]) reported in the radiotherapy group than in the TORS plus neck dissection group, and more cases of trismus in the TORS plus neck dissection group (nine [26%] vs one [3%]). The most common adverse events in the radiotherapy group were dysphagia (n=6), hearing loss (n=6), and mucositis (n=4), all grade 3, and in the TORS plus neck dissection group, dysphagia (n=9, all grade 3) and there was one death caused by bleeding after TORS. INTERPRETATION: Patients treated with radiotherapy showed superior swallowing-related QOL scores 1 year after treatment, although the difference did not represent a clinically meaningful change. Toxicity patterns differed between the groups. Patients with OPSCC should be informed about both treatment options. FUNDING: Canadian Cancer Society Research Institute Grant (#701842), Ontario Institute for Cancer Research Clinician-Scientist research grant, and the Wolfe Surgical Research Professorship in the Biology of Head and Neck Cancers grant.

Headache Outcomes After Treatment of Unruptured Intracranial Aneurysm: A Systematic Review and Meta-Analysis.

Background and Purpose- While unruptured intracranial aneurysms may be discovered incidentally in the workup of chronic headache, it remains unclear whether their treatment ultimately impacts headache severity. We aim to conduct a systematic review and meta-analysis assessing headache severity after treatment of unruptured intracranial aneurysm. Methods- MEDLINE and EMBASE were systematically reviewed. Results- Data from 7 studies met inclusion criteria (309 nonduplicated patients). The standard mean difference in pre- and post-intervention headache severity was estimated at -0.448 (95% CI, -0.566 to -0.329) under a random effects model. No significant heterogeneity was noted nor was any significant publication bias demonstrated. Conclusions- This is the first systematic review assessing postoperative headache severity following treatment of unruptured intracranial aneurysm. While a significant reduction in headache severity was observed, further investigation into this phenomenon is recommended before it influences clinical practice. Future study should stratify headache outcomes by aneurysm size, location, and treatment modality.

Potential clinical implications of HPV status and expressions of p53 and cyclin D1 among oropharyngeal cancer patients.

BACKGROUND: There is increasing evidence that high-risk human papillomavirus plays significant role in oropharyngeal cancer; however, there is lack of knowledge on the interplay between the virus and its downstream-related molecules and their possible prognostic values. The objectives of the study are to better understand the interplay of the HR-HPV and its associated downstream molecules and to evaluate potential biomarkers for patient outcomes. METHODS: We conducted a retrospective study with available formalin-fixed, paraffin-embedded tissue from 244 oropharyngeal cancer patients that received curative radiotherapy or concurrent chemoradiotherapy from 2000 to 2008. In addition to chart review, we performed HPV DNA and RNA in situ hybridization and immunohistochemistry for p53, the retinoblastoma protein, p16, and cyclin D1 analysis. Cox proportional hazard and Kaplan-Meier survival analysis were used to determine the prognostic markers for clinical outcomes. RESULTS: Patients averaged 57.3 ± 9.4 year-old and were mostly males (76.2%) and ever-smokers (76.2%). All patients received curative radiotherapy, and 44.3% received concurrent chemoradiotherapy. We detected the human papillomavirus in 77.9% of study patients. Ever-smokers, more advanced tumor stage, and receiving radiotherapy only had poorer 5-year overall survival, disease-specific survival, and loco-regional recurrence. Cases with positive human papillomavirus and p53 overexpression had poorer disease-specific survival. Cases without human papillomavirus, but cyclin D1 overexpression, were associated with poorer 5-year overall survival. CONCLUSIONS: Our data suggest that additional p53 and cyclin D1 testing may benefit oropharyngeal cancer patients with known human papillomavirus status.

Revisiting the gastric pull-up for pharyngoesophageal reconstruction: A systematic review and meta-analysis of mortality and morbidity.

Gastric pull-up (GPU) is among the oldest techniques for reconstructing the pharyngoesophageal junction following cancer resection. This review examines morbidity and mortality rates following GPU pharyngoesophageal junction reconstruction from 1959 until present: 77 studies, 2,705 patients. The odds of mortality, anastomotic complications, and other complications decreased by 37.2% (95%CI = 28.0-45.3%; P < 0.0001), 8.0% (95%CI = -2.1 to 17.1%; P = 0.12), 21.0% (95%CI 3.5-35.2%; P = 0.021) per decade respectively. J. Surg. Oncol. 2016;114:907-914. © 2016 Wiley Periodicals, Inc.

Prevention and management of treatment-induced pharyngo-oesophageal stricture.

Pharyngo-oesophageal stricture (PES) is a serious complication that occurs in up to a third of patients treated with external beam radiotherapy or combined chemoradiotherapy for head and neck cancer. This entity is under-reported and as a result, our understanding of the pathophysiology and prevention of this complication is restricted. This Review presents the knowledge so far on radiation-related and non-radiation-related risk factors for PES, including tumour stage and subsite, patient age, and comorbidities. The interventions to decrease this toxicity are discussed, including early detection of PES, initiation of an oral diet, and protection of swallowing structures from high-dose radiation. We discuss various treatment options, including swallowing exercises and manoeuvres, endoscopic dilatations, and for advanced cases, oesophageal reconstruction. Study of the subset of patients who develop this toxicity and early recognition and intervention of this pathological change in future trials will help to optimise treatment of these patients.

Enabling extracorporeal ultrasound imaging with the da Vinci robot for transoral robotic surgery: a feasibility study.

PURPOSE: Transoral robotic surgery (TORS) is a challenging procedure due to its small workspace and complex anatomy. Ultrasound (US) image guidance has the potential to improve surgical outcomes, but an appropriate method for US probe manipulation has not been defined. This study evaluates using an additional robotic (4th) arm on the da Vinci Surgical System to perform extracorporeal US scanning for image guidance in TORS. METHODS: A stereoscopic imaging system and da Vinci-compatible US probe attachment were developed to enable control of the extracorporeal US probe from the surgeon console. The prototype was compared to freehand US by nine operators in three tasks on a healthy volunteer: (1) identification of the common carotid artery, (2) carotid artery scanning, and (3) identification of the submandibular gland. Operator workload and user experience were evaluated using a questionnaire. RESULTS: The robotic US tasks took longer than freehand US tasks (2.09x longer; p = 0.001 ) and had higher operator workload (2.12x higher; p = 0.004 ). However, operator-rated performance was closer (avg robotic/avg freehand = 0.66; p = 0.017 ), and scanning performance measured by MRI-US average Hausdorff distance provided no statistically significant difference. CONCLUSION: Extracorporeal US scanning for intraoperative US image guidance is a convenient approach for providing the surgeon direct control over the US image plane during TORS, with little modification to the existing operating room workflow. Although more time-consuming and higher operator workload, several methods have been identified to address these limitations.

Predicting Tracheostomy Need on Admission to the Intensive Care Unit-A Multicenter Machine Learning Analysis.

OBJECTIVE: It is difficult to predict which mechanically ventilated patients will ultimately require a tracheostomy which further predisposes them to unnecessary spontaneous breathing trials, additional time on the ventilator, increased costs, and further ventilation-related complications such as subglottic stenosis. In this study, we aimed to develop a machine learning tool to predict which patients need a tracheostomy at the onset of admission to the intensive care unit (ICU). STUDY DESIGN: Retrospective Cohort Study. SETTING: Multicenter Study of 335 Intensive Care Units between 2014 and 2015. METHODS: The eICU Collaborative Research Database (eICU-CRD) was utilized to obtain the patient cohort. Inclusion criteria included: (1) Age >18 years and (2) ICU admission requiring mechanical ventilation. The primary outcome of interest included tracheostomy assessed via a binary classification model. Models included logistic regression (LR), random forest (RF), and Extreme Gradient Boosting (XGBoost). RESULTS: Of 38,508 invasively mechanically ventilated patients, 1605 patients underwent a tracheostomy. The XGBoost, RF, and LR models had fair performances at an AUROC 0.794, 0.780, and 0.775 respectively. Limiting the XGBoost model to 20 features out of 331, a minimal reduction in performance was observed with an AUROC of 0.778. Using Shapley Additive Explanations, the top features were an admission diagnosis of pneumonia or sepsis and comorbidity of chronic respiratory failure. CONCLUSIONS: Our machine learning model accurately predicts the probability that a patient will eventually require a tracheostomy upon ICU admission, and upon prospective validation, we have the potential to institute earlier interventions and reduce the complications of prolonged ventilation.

Cost-Effectiveness of the ACR TIRADS Compared to the ATA 2015 Risk Stratification Systems in the Evaluation of Incidental Thyroid Nodules.

RATIONALE AND OBJECTIVES: Thyroid nodules are a common incidental imaging finding and prone to overdiagnosis. Several risk stratification systems have been developed to reduce unnecessary work-up, with two of the most utilized including the American Thyroid Association 2015 (ATA2015) and the newer American College of Radiology Thyroid Imaging, Reporting and Data System (TIRADS) guidelines. The purpose of this study is to evaluate the cost-effectiveness of the ATA2015 versus the TIRADS guidelines in the management of incidental thyroid nodules. METHODS: A cost-utility analysis was conducted using decision tree modeling, evaluating adult patients with incidental thyroid nodules < 4 cm. Model inputs were populated using published literature, observational data, and expert opinion. Single-payer perspective, Canadian dollar currency, five-year time horizon, willingness to pay (WTP) threshold of $50,000, and discount rate of 1.5% per annum were utilized. Scenario, deterministic and probabilistic sensitivity analyses were performed. The primary outcome was the incremental cost-effectiveness ratio (ICER) expressed as incremental cost per quality-adjusted life year (QALY) gained. RESULTS: For the base case scenario, TIRADS dominated the ATA2015 strategy by a slim margin, producing 0.005 more QALYs at $25 less cost. Results were sensitive to the malignancy rate of biopsy and the utilities of a patient with a benign nodule/subclinical malignancy or under surveillance. Probabilistic sensitivity analysis showed that TIRADS was the more cost-effective option 79.7% of the time. CONCLUSION: The TIRADS guidelines may be the more cost-effective strategy by a small margin compared to ATA2015 in most scenarios when used to risk stratify incidental thyroid nodules.

Incidence and complications of hypothyroidism postlaryngectomy: A systematic review and meta-analysis.

BACKGROUND: Hypothyroidism is common postlaryngectomy and is associated with laryngectomy-specific complications. The objective of this study is to determine the incidence and predictors of hypothyroidism postlaryngectomy and its associated complications. METHODS: Systematic review, data extraction, and meta-analyses were performed following the PRISMA protocol. Six databases were searched for studies reporting on postlaryngectomy thyroid status with incidence, risk factors, management, or complications. RESULTS: Fifty-one studies with 6333 patients were included. The pooled incidence of postlaryngectomy hypothyroidism is 49% (CI 42%-57%). Subgroup analysis showed postlaryngectomy hypothyroidism rates significantly correlated with hemithyroidectomy and radiotherapy. Patients who underwent laryngectomy, hemithyroidectomy, and radiotherapy had a 65% (CI 59%-71%) rate of hypothyroidism; laryngectomy and hemithyroidectomy 46% (CI 33%-60%); laryngectomy and radiotherapy 26% (CI 19%-35%); and laryngectomy alone 11% (CI 4%-27%) (p < 0.001). CONCLUSIONS: Laryngectomized patients with partial thyroidectomy or radiation therapy are at significant risk of postoperative hypothyroidism. Evidence-based protocols for early detection and (prophylactic) treatment should be established.

Outcomes of Radial Forearm Free Flap Closure With Split-Thickness Skin Graft Versus Primary Closure.

BACKGROUND: This study compares patient-reported functional and aesthetic outcomes of split-thickness skin graft (STSG) versus hatchet flap closure of radial forearm free flap (RFFF) donor site. METHODS: Patients with RFFF (2015-2020) were retrospectively identified. Those willing to participate in patient-reported outcomes (PRO) filled out Patient-Observer Scar Assessment Scale (POSAS) and Michigan Hand Outcome Questionnaire (MHOQ). RESULTS: 198 patients met our inclusion criteria and 81 participated in PRO. There was a higher rate of tendon exposure in STSG versus hatchet flap (11 vs. 1, p = 0.0019), but a lower rate of skin necrosis (5 vs. 16, p = 0.0190) and epidermolysis (1 vs. 12, p = 0.0028). Scar quality in STSG was superior to hatchet flap in all domains of POSAS. MHOQ scores were similar between both groups with no statistical difference in overall scores (p = 0.2165). CONCLUSIONS: STSG appeared to have less compromise in activities of daily living, better satisfaction and improved scar quality than hatchet flap, but a higher rate of tendon exposure. LEVEL OF EVIDENCE: 3 Laryngoscope, 2024.

Donor site morbidity after scapula free flap surgery of head and neck reconstruction: A systematic review and meta-analysis.

BACKGROUND: The scapula free flap is becoming increasingly more utilized in head and neck reconstruction due to its natural geometry and soft tissue versatility. This study reviews the incidence rate, risk factors, and treatments of complications of scapula donor site morbidity. METHODS: A review was performed for articles published between October 1990 and November 2022 in Medline (OVID), PubMed, Web of Science, and CENTRAL. After screening, 24 articles meeting the criteria were included. RESULTS: Overall, 660 head and neck surgeries with the scapula donor bone across 24 studies were included. Twenty studies of 612 scapula free flaps reported a pooled postoperative complication rate of 10.7%, with no major complications. Seven studies of 199 scapula reconstructions showed a mean Disability of Arm, Shoulder and Hand (DASH) score of 14.39/100. CONCLUSION: With its low rate of morbidity, the scapula flap presents itself as a good alternative for patients at risk for poor healing.

Computational models and their applications in biomechanical analysis of mandibular reconstruction surgery.

Advanced head and neck cancers involving the mandible often require surgical removal of the diseased parts and replacement with donor bone or prosthesis to recreate the form and function of the premorbid mandible. The degree to which this reconstruction successfully replicates key geometric features of the original bone critically affects the cosmetic and functional outcomes of speaking, chewing, and breathing. With advancements in computational power, biomechanical modeling has emerged as a prevalent tool for predicting the functional outcomes of the masticatory system and evaluating the effectiveness of reconstruction procedures in patients undergoing mandibular reconstruction surgery. These models offer cost-effective and patient-specific treatment tailored to the needs of individuals. To underscore the significance of biomechanical modeling, we conducted a review of 66 studies that utilized computational models in the biomechanical analysis of mandibular reconstruction surgery. The majority of these studies employed finite element method (FEM) in their approach; therefore, a detailed investigation of FEM has also been provided. Additionally, we categorized these studies based on the main components analyzed, including bone flaps, plates/screws, and prostheses, as well as their design and material composition.

To what extent can mastication functionality be restored following mandibular reconstruction surgery? A computer modeling approach.

STATEMENT OF PROBLEM: Advanced cases of head and neck cancer involving the mandible often require surgical removal of diseased sections and subsequent replacement with donor bone. During the procedure, the surgeon must make decisions regarding which bones or tissues to resect. This requires balancing tradeoffs related to issues such as surgical access and post-operative function; however, the latter is often difficult to predict, especially given that long-term functionality also depends on the impact of post-operative rehabilitation programs. PURPOSE: To assist in surgical decision-making, we present an approach for estimating the effects of reconstruction on key aspects of post-operative mandible function. MATERIAL AND METHODS: We develop dynamic biomechanical models of the reconstructed mandible considering different defect types and validate them using literature data. We use these models to estimate the degree of functionality that might be achieved following post-operative rehabilitation. RESULTS: We find significant potential for restoring mandibular functionality, even in cases involving large defects. This entails an average trajectory error below 2 mm, bite force comparable to a healthy individual, improved condyle mobility, and a muscle activation change capped at a maximum of 20%. CONCLUSION: These results suggest significant potential for adaptability in the masticatory system and improved post-operative rehabilitation, leading to greater restoration of jaw function.

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.