Functional evaluation of mandibular reconstruction with bone free flap. A GETTEC study

Segmental Mandibulectomy and Mandibular Reconstruction with Fibula-Free Flap Using a 3D Template

INTRODUCTION

The present study evaluates the influence of virtual surgical planning with a preoperative 3D resin model on aesthetic and functional outcomes in patients treated by segmental mandibulectomy and reconstruction with fibula-free flap for oral cancer.

METHODS

All consecutive patients who underwent segmental mandibulectomy and mandibular reconstruction with a fibula-free flap using a 3D template at our department from January 2021 to January 2023 were included in the study. "Patients control" were patients treated by reconstruction with a fibula-free flap without using a 3D template. Three-dimensional modeling was performed by converting from preoperative computed tomography to a stereolithography format to obtain the resin 3D models. Qualitative analysis of anatomical and aesthetic results consisted of the evaluation of the patients' aesthetic and functional satisfaction and the symmetry of the mandibular contour observed at clinical examination. Quantitative analysis was based on the assessment of the accuracy and precision of the reconstruction by comparing preoperative and postoperative computed tomograms as objective indicators.

RESULTS

Seven patients (five males and two females, mean age of 65.1 years) were included in the study. All patients showed a symmetric mandibular contour based on the clinical examination. After recovery, six patients (85.7%) considered themselves aesthetically satisfied. The quantitative analysis (assessed in six/seven patients) showed that the mean difference between preoperative and postoperative intercondylar distance, intergonial angle distance, anteroposterior dimension, and gonial angle improved in the 3D template-assisted group.

CONCLUSION

The 3D-printed template for mandibular reconstruction with microvascular fibula-free flap can improve aesthetic outcomes in comparison with standard approaches.

Target Delineation in Postoperative Radiation Therapy for Head and Neck Cancer After Flap Reconstruction

Delineation of the clinical target volume (CTV) after resection of head and neck cancer can be challenging, especially after flap reconstruction. The main area of contention is whether the entire flap should be included in the CTV. Several case series have reported marginal misses and intraflap failures when the entire flap was not routinely included in the CTV. On the other hand, available data have not convincingly demonstrated a detriment to long-term outcomes using intensity modulated radiotherapy after flap reconstruction. On the contrary, postoperative radiation can facilitate epilation and mucosalization of the flap tissue, reduce flap bulk, and improve long-term esthetic and functional outcomes. Therefore, our standard practice is to include the entire flap in the CTV. In certain scenarios, we may allow for a lower dose to part of flap distant from the resection bed than the flap-tumor bed junction, where recurrences are most likely. We provide three case vignettes describing such scenarios where sparing part of the flap, and more importantly, the nearby uninvolved native tissue, from high-dose radiation may be justified.

Changes in condylar position and morphology after mandibular reconstruction by vascularized fibular free flap with condyle preservation

OBJECTS

Changes in condylar position and morphology after mandibular reconstruction are important to aesthetic and functional rehabilitation. We evaluated changes in condylar position and morphology at different stages after mandibular reconstruction using vascularized fibular free flap with condyle preservation.

MATERIALS AND METHODS

A total of 23 patients who underwent mandibular reconstruction with fibular flap were included in this retrospective study. CT data of all patients were recorded before surgery (T0), 7 to 14 days after surgery (T1), and at least 6 months after surgery (T2). Five parameters describing the condylar position and 4 parameters describing the morphology were measured in sagittal and coronal views of CT images. The association between clinical characteristics and changes in condylar position and morphology was analyzed. A finite element model was established to investigate the stress distribution and to predict the spatial movement tendency of the condyle after reconstruction surgery.

RESULTS

The condylar position changed over time after mandibular reconstruction. The ipsilateral condyles moved inferiorly after surgery (T0 to T1) and continually move anteriorly, inferiorly, and laterally during long-term follow-up (T1 to T2). Contrary changes were noted in the contralateral condyles with no statistical significance. No morphological changes were detected. The relationship between clinical characteristics and changes in condylar position and morphology was not statistically significant. A consistent result was observed in the finite element analysis.

CONCLUSION

Condylar positions showed obvious changes over time after mandibular reconstruction with condylar preservation. Nevertheless, further studies should be conducted to evaluate the clinical function outcomes and condylar position.

CLINICAL RELEVANCE

These findings can form the basis for the evaluation of short-term and long-term changes in condylar position and morphology among patients who have previously undergone mandibular reconstruction by FFF with condyle preservation.

Dental management in head and neck cancers: from intensity-modulated radiotherapy with photons to proton therapy

INTRODUCTION

Despite reduction of xerostomia with intensity-modulated compared to conformal X-ray radiotherapy, radiation-induced dental complications continue to occur. Proton therapy is promising in head and neck cancers to further reduce radiation-induced side-effects, but the optimal dental management has not been defined.

MATERIAL AND METHODS

Dental management before proton therapy was assessed compared to intensity-modulated radiotherapy based on a bicentric experience, a literature review and illustrative cases.

RESULTS

Preserved teeth frequently contain metallic dental restorations (amalgams, crowns, implants). Metals blur CT images, introducing errors in tumour and organ contour during radiotherapy planning. Due to their physical interactions with matter, protons are more sensitive than photons to tissue composition. The composition of restorative materials is rarely documented during radiotherapy planning, introducing dose errors. Manual artefact recontouring, metal artefact-reduction CT algorithms, dual or multi-energy CT and appropriate dose calculation algorithms insufficiently compensate for contour and dose errors during proton therapy. Physical uncertainties may be associated with lower tumour control probability and more side-effects after proton therapy. Metal-induced errors should be quantified and removal of metal restorations discussed on a case by case basis between dental care specialists, radiation oncologists and physicists. Metallic amalgams can be replaced with water-equivalent materials and crowns temporarily removed depending on rehabilitation potential, dental condition and cost. Implants might contraindicate proton therapy if they are in the proton beam path.

CONCLUSION

Metallic restorations may more severely affect proton than photon radiotherapy quality. Personalized dental care prior to proton therapy requires multidisciplinary assessment of metal-induced errors before choice of conservation/removal of dental metals and optimal radiotherapy.

[Elective tracheostomy in COVID-19 patients: experience with a standardized interdisciplinary approach]

Berichtet wird über die Erfahrungen mit einer interdisziplinären klinikinternen SOP (Standard Operation Procedure) zur Tracheostomie (TS) bei „Coronavirus-Disease“(COVID-19)-Patienten, unter Berücksichtigung der allgemeinen nationalen und internationalen Empfehlungen. Der interdisziplinär festgelegte operative Zeitpunkt der TS aufgrund einer prolongierten invasiven Beatmung und frustranen Weaning-Versuchen betraf Phasen sowohl hoher als auch niedriger Erkrankungsaktivität. Es wurden 5 TS bei Patienten mit einem Durchschnittsalter von 70,6 Jahren durchgeführt. Neben den Standard-COVID-19-Schutzmaßnahmen für das medizinische Personal zur Vermeidung einer nosokomialen COVID-19-Infektion führt die SOP-unterstützte Kommunikation während der TS zu einer periprozeduralen Sicherheit aller Beteiligten. COVID-19-Erkrankungen des medizinischen Personals der beteiligten Abteilungen sind bisher nicht bekannt.

Tracheostomy, ventilatory wean, and decannulation in COVID-19 patients

PURPOSE

COVID-19 patients requiring mechanical ventilation can overwhelm existing bed capacity. We aimed to better understand the factors that influence the trajectory of tracheostomy care in this population to facilitate capacity planning and improve outcomes.

METHODS

We conducted an observational cohort study of patients in a high-volume centre in the worst-affected region of the UK including all patients that underwent tracheostomy for COVID-19 pneumonitis ventilatory wean from 1st March 2020 to 10th May 2020. The primary outcome was time from insertion to decannulation. The analysis utilised Cox regression to account for patients that are still progressing through their tracheostomy pathway.

RESULTS

At the point of analysis, a median 21 days (IQR 15-28) post-tracheostomy and 39 days (IQR 32-45) post-intubation, 35/69 (57.4%) patients had been decannulated a median of 17 days (IQR 12-20.5) post-insertion. The overall median age was 55 (IQR 48-61) with a male-to-female ratio of 2:1. In Cox regression analysis, FiO₂ at tracheostomy ≥ 0.4 (HR 1.80; 95% CI 0.89-3.60; p = 0.048) and last pre-tracheostomy peak cough flow (HR 2.27; 95% CI 1.78-4.45; p = 0.001) were independent variables associated with prolonged time to decannulation.

CONCLUSION

Higher FiO₂ at tracheostomy and higher pre-tracheostomy peak cough flow are associated with increased delay in COVID-19 tracheostomy patient decannulation. These finding comprise the most comprehensive report of COVID-19 tracheostomy decannulation to date and will assist service planning for future peaks of this pandemic.