Heparin regimes in head and neck cancer flap surgery: A retrospective cohort study of free flap complications graded by Clavien-Dindo.

The purpose of the current study was to compare two different antithrombotic protocols for free flap reconstruction in head and neck squamous cell carcinoma (HNSCC) patients. Postoperative complications were graded using the Clavien-Dindo (CD) classification and compared between the two groups: the low-molecular-weight heparin (LMWH) group (n = 57) and the unfractionated heparin (UFH) group (n = 59). Patients with HNSCC from January 2010 to January 2022 were included. A total of 116 patients with a mean age of 60.46 years (range 43-83 years) were included in this study. In all, 81 were male (69.8%), and 35 were female (30.2%). Most patients (48.3%) had only grade 1 or 2 complications. CD grades (1-5) were similar between the two groups. Flap loss occurred in 2 patients (1.7%) in the LMWH group (p = 239). Prognostic factors of flap loss were high BMI, hypertension, high T stage, and high N stage. No differences were found between the groups in regard to age, sex, operating times, flap source, recipient vessels and overall complications. The results of this study demonstrate that UFH was as safe and effective as LMWH regarding postoperative complications. Free flap surgery is safe and effective for head and neck reconstruction.

Healthcare Ethics Consultation in Austria: Joining the International Path of Professionalization.

AbstractHealthcare ethics consultation has been developed, practiced, and analyzed internationally. However, only a few professional standards have evolved globally in this field that would be comparable to standards in other areas of healthcare. This article cannot compensate for this situation. It contributes to the ongoing debate on professionalization by presenting experiences with ethics consultation in Austria, though. After exploring its contexts and providing an overview of one of its primary ethics programs, the article analyzes the underlying assumptions of "ethics consultation" as an essential effort on the path to professionalize ethics consultation.

The impact of COVID-19 on oral squamous cell carcinoma's diagnostic stage-A retrospective study.

OBJECTIVE: The COVID-19 pandemic has had an impact on patients' access to primary care services. A timely diagnosis of oral squamosa cell carcinoma is paramount. This study aims to quantify the pandemic's effect on tumor volume at the time of initial diagnosis. MATERIALS AND METHODS: In a retrospective study, all primarily diagnosed cancer patients between March 2018 and March 2022 were compiled; the TNM stage and the tumor volume were evaluated. Tumor volumes were calculated using pathology or radiology reports. RESULTS: In total, 162 newly diagnosed tumor cases were included in this study. Of these, 76 (46.9%) cases were allocated in the "pre-COVID-19" group and 86 (53.1%) in the "COVID-19" group. Patients diagnosed during the "COVID-19" period showed a significantly advanced T stage (p < 0.001) and larger mean tumor volumes (53.16 ± 73.55 cm3 vs. 39.89 ± 102.42 cm3 ; p = 0.002) when compared to the control group. CONCLUSION: Tumor volume and T stage were significantly advanced in the "COVID-19" group when compared to prepandemic data. We hypothesize that the postponement of routine dental check-ups may explain this finding. Hence, dentists and primary care providers are encouraged to place particular emphasis on screening during routine check-ups.

Donor Site Morbidity and Quality of Life after Microvascular Head and Neck Reconstruction with a Chimeric, Thoracodorsal, Perforator-Scapular Flap Based on the Angular Artery (TDAP-Scap-aa Flap).

Extensive defects in the head and neck area often require the use of advanced free flap reconstruction techniques. In this study, the thoracodorsal perforator-scapular free flap technique based on the angular artery (TDAP-Scap-aa flap) was postoperatively evaluated regarding the quality of life and the donor site morbidity using the standardized SF-36 and DASH questionnaires (short form health 36 and disabilities of the arm, shoulder and hand scores). Over a five-year period (2016−2020), 20 selected cases (n = 20) requiring both soft and hard tissue reconstruction were assessed. On average, the harvested microvascular free flaps consisted of 7.8 ± 2.1 cm hard tissue and 86 ± 49.8 cm2 soft tissue components. At the donor site (subscapular region), only a mild morbidity was observed (DASH score: 21.74 ± 7.3 points). When comparing the patients' postoperative quality of life to the established values of the healthy German norm population, the observed SF-36 values were within the upper third (>66%) of these established norm values in almost all quality-of-life subcategories. The mild donor site morbidity and the observed quality of life indicate only a small postoperative impairment when using the TDAP-Scap-aa free flap for the reconstruction of extensive maxillofacial defects.

[Metronidazole - spectrum of activity, use and side effects]. / Metronidazol ­ Wirkungsspektrum, Anwendung und Nebenwirkungen.

This contribution gives an overview of the use, therapeutic effects and side effects of the antibiotic substance Metronidazole. Metronidazole is effective in the treatment support of paradontitis, microbial-caused halitosis, perioral skin infections and odontogenic hard or soft tissue abscess formations related to anaerobic bacterial infections. Due to its anti- parasitic effect, Metronidazole is also effective in the treatment of protozoa. In adults and children from 12 years on, 200 mg Metronidazole to a maximum of 2000 mg Metronidazole per day can be administered. In children below 12 years of age, an antibiotic dose of Metronidazole between 20 to 30 mg per kilogram body weight is advised.

Intravenous ibuprofen versus diclofenac plus orphenadrine in orthognathic surgery: a prospective, randomized, double-blind, controlled clinical study.

OBJECTIVES: The aim of this prospective, randomized, double-blind, controlled clinical study was to evaluate the analgesic effect of ibuprofen versus diclofenac plus orphenadrine on postoperative pain in orthognathic surgery. MATERIAL AND METHODS: Patients who underwent orthognathic surgery were randomized into two groups to receive intravenously either 600 mg of ibuprofen (I-group) or 75 mg diclofenac plus 30 mg orphenadrine (D-group), both of which were given twice daily. Additionally, both groups were given metamizole 500 mg. Rescue pain medication consisted of acetaminophen 1000 mg and piritramide 7.5 mg as needed. To assess the pain intensity, the primary end point was the numeric rating scale (NRS) recorded over the course of the hospital stay three times daily for 3 days. RESULTS: One hundred nine patients were enrolled (age range, 18 to 61 years) between May 2019 and November 2020. Forty-eight bilateral sagittal split osteotomies (BSSO) and 51 bimaxillary osteotomies (BIMAX) were performed. Surgical subgroup analysis found a significant higher mean NRS (2.73 vs.1.23) in the BIMAX D-group vs. I-group (p = 0.015) on the third postoperative day. Additionally, as the patient's body mass index (BMI) increased, the mean NRS (r = 0.517, p = 0.001) also increased. No differences were found between age, gender, length of hospital stay, weight, operating times, number of patients with complete pain relief, acetaminophen or piritramide intake, and NRS values. No adverse events were observed. CONCLUSION: The results of this study demonstrate that ibuprofen administration and lower BMI were associated with less pain for patients who underwent bimaxillary osteotomy on the third postoperative day. Therefore, surgeons may prefer ibuprofen for more effective pain relief after orthognathic surgery. CLINICAL RELEVANCE: Ibuprofen differs from diclofenac plus orphenadrine in class and is a powerful analgetic after orthognathic surgery.

Gender-specific differences in haemostatic parameters and their influence on blood loss in bimaxillary surgery.

OBJECTIVE: The objectives of this prospective cohort study were to establish gender-related differences in blood loss and haemostatic profiles associated with bimaxillary surgery. In addition, we aimed to identify if any gender differences could be established which might help predict blood loss volume. MATERIALS AND METHODS: Fifty-four patients (22 males; 32 females) undergoing bimaxillary surgery for skeletal dentofacial deformities were eligible for inclusion. Blood samples were taken 1 day preoperatively and 48 h postoperatively for detailed gender-specific coagulation analysis incorporating global coagulation assays (endogenous thrombin potential) and specific coagulation parameters. Blood loss was measured at two different time points: (1) the end of surgery, visible intraoperative blood loss (IOB) using 'subtraction method'; and (2) 48 h postoperatively perioperative bleeding volume (CBL-48 h) using 'haemoglobin-balance method' and Nadler's formula. Correlation and regression analyses were performed to identify relevant parameters affecting the amount of blood loss. RESULTS: Significant differences in IOB and CBL-48 h were observed (p < 0.001). Men had higher IOB versus women, lacking statistical significance (p = 0.056). In contrast, men had significantly higher CLB-48 h (p = 0.019). Reduced CBL-48 h was shown to be most closely associated with the level of Antithrombin-III being decreased in females. CONCLUSIONS: Male gender is associated with higher IOB and CBL-48 compared with females. Gender does not affect IOB regarding haemostatic profile but does correlate strongly with procedure length. Conversely, CBL-48 is closely associated with gender-specific imbalances in the anticoagulant system. CLINICAL RELEVANCE: Knowledge of gender-related differences will help clinicians establish predictive factors regarding excessive blood loss in orthognathic surgery and identify at-risk patients.

Expect the unexpected: The course of the inferior alveolar artery - Preliminary results and clinical implications.

INTRODUCTION: The anatomical position of the inferior alveolar artery (IAA) within the mandibular canal and in relation to the substructures of the neurovascular mandibular bundle has been sparsely described to date. More detailed information on the exact IAA position would be beneficial for both dental and maxillofacial surgical procedures to minimize complications such as bleeding, nerve compression hematoma, and sensory deficiency. MATERIAL AND METHODS: In 31 Thiel-preserved and fresh-frozen cadaver hemimandibles the position of the IAA in relation to the structures of the inferior alveolar neurovascular bundle and the mandible borders was analyzed anatomically and histologically. RESULTS: In 77.4% of the cases, rotation of the IAA around the mental nerve was apparent, resulting in a typical site-dependent IAA position. While the IAA was situated buccally within the pterygomandibular space, buccal-inferior in the mandibular foramen, superior in the molar region, and lingually in the premolar region. In 12.9% of the cases, a persistent lingual position of the IAA was observed for the entire mandibular canal. In one case, an additional mandibular canal and an accessory IAA were identified. DISCUSSION: This study provides new and encompassing information on the complete course and position of the IAA. This course is of practical use for oral implantology and various surgical procedures in dental- and maxillofacial surgery. Variations in the typical IAA course and site-dependent positional changes may be referred to as mandible growth and functional adaption to occlusion anomalies. This report helps enhance the morphological and functional understanding of IAA relationship during mandible development.

[Local anesthesia in children: standard and limits]. / Lokalanästhesie bei Kindern: Standard und Grenzen.

The use of local anesthetics is known to be safe and efficient in surgical and dental treatments. Local anesthetics are essential in dentistry for appropriate pain control as they inhibit nociception generated during surgical and dental procedures. However, among other precautions, attention has to be paid to the individual maximum dose of the local anesthetics that is administered. This is especially important for children who are, due to their low body weight, more prone to adverse events following substance overdose. Therefore, this contribution gives advice for general dentists on the accurate use and maximum dose of local anesthetics in children.

[Application of tranexamic acid within the field of dentistry]. / Die Anwendung von Tranexamsäure (Cyklokapron®) in der Zahnmedizin.

The antifibrinolytic agent tranexamic acid (TXA) is well known for its capacity to effectively reduce intraoperative blood loss. The effect mechanism of TXA is based on the indirect inhibition of fibrin degradation, whereby existing blood clots within the surgical area are stabilized. Consecutively, the amount of blood loss can be reduced. Due to its great efficacy to minimize blood loss and its low rate of unintended side effects, TXA is regularly used in different surgical fields. Within the field of dentistry TXA is not applied on a regular basis, however, it presents a highly effective and convenient treatment option to reduce bleeding complications.

Is there a hidden blood loss in orthognathic surgery and should it be considered? Results of a prospective cohort study.

The aim of this prospective observational study was to investigate the parameter 'hidden blood loss' (HBL) in the context of orthognathic surgery, incorporating undetected bleeding volumes occurring intra- and postoperatively. Orthognathic bleeding volumes were recorded at three different time points. At the end of the operation the visible intraoperative blood loss (VBL) was measured. Additionally, the perioperative blood loss was calculated 24 h and 48 h postoperatively using the 'haemoglobin balance method'. Analysis of the HBL was based on the difference between the visible intraoperative blood loss (VBL) and calculated blood loss (CBL), determined 48 h after surgery. 82 patients (male 33, female 49) were included in this study, of whom 41 underwent bimaxillary surgery and of whom 41 underwent Bilateral Sagittal Split Osteotomy (BSSO). Statistically significant differences with reference to the absolute bleeding volumes were found when comparing the two treatment modalities. In terms of HBL, a bleeding volume of 287.2 ml (±265.9) in the bimaxillary group and 346.9 ml (±271.3) in the BSSO cohort was recorded. This accounted for 32.2% (bimaxillary surgery) and 62.6% (BSSO) of the CBL after 48 h (BIMAX vs. BSSO, p < 0.001). HBL is a valuable adjunct to record within the perioperative management of orthognathic surgery to further improve patient safety and postoperative outcomes.

Robin Sequence: 5-Year Speech Outcomes-A Case-Control Study.

BACKGROUND: Pierre Robin sequence (Robin sequence) is defined as the triad of micrognathia, glossoptosis, and airway obstruction. It is frequently associated with palatal clefting. In recent years, increased interest in speech outcomes of cleft patients diagnosed with Robin sequence has been shown. METHODS: Speech outcomes of cleft patients with Robin sequence were assessed at age 5 in comparison with a cleft palate-only cohort. Speech parameters were evaluated according to the Cleft Audit Protocol for Speech-Augmented and analyzed using the National Audit Standards for Speech (United Kingdom). All patients were treated in the same institution during the same period (2005 to 2012). Subjects who needed nasopharyngeal airway support and those whose airway was managed by positioning only were eligible. RESULTS: Fifty-one cleft patients diagnosed with Robin sequence were included in this study. Outcomes were compared to those of 128 nonsyndromic cleft palate-only patients.Patients with Robin sequence were shown to present with a significantly higher rate of cleft speech characteristics in comparison to the reference cohort (p = 0.001). Furthermore, it was shown that Robin sequence is associated with a significantly higher rate of secondary speech surgery for velopharyngeal dysfunction before the age of 5 (p = 0.016). Robin sequence patients with a nasopharyngeal airway presented with a higher rate of cleft speech characteristics compared to Robin sequence patients managed with positioning only. CONCLUSION: Cleft patients with Robin sequence are more likely to need further surgery to correct velopharyngeal dysfunction before the age of 5 and are more prone to present with cleft speech characteristics at the age of 5. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, II.

Synthetic skull bone defects for automatic patient-specific craniofacial implant design.

Patient-specific craniofacial implants are used to repair skull bone defects after trauma or surgery. Currently, cranial implants are designed and produced by third-party suppliers, which is usually time-consuming and expensive. Recent advances in additive manufacturing made the in-hospital or in-operation-room fabrication of personalized implants feasible. However, the implants are still manufactured by external companies. To facilitate an optimized workflow, fast and automatic implant manufacturing is highly desirable. Data-driven approaches, such as deep learning, show currently great potential towards automatic implant design. However, a considerable amount of data is needed to train such algorithms, which is, especially in the medical domain, often a bottleneck. Therefore, we present CT-imaging data of the craniofacial complex from 24 patients, in which we injected various artificial cranial defects, resulting in 240 data pairs and 240 corresponding implants. Based on this work, automatic implant design and manufacturing processes can be trained. Additionally, the data of this work build a solid base for researchers to work on automatic cranial implant designs.

Augmented Reality for Head and Neck Carcinoma Imaging: Description and Feasibility of an Instant Calibration, Markerless Approach.

BACKGROUND AND OBJECTIVE: Augmented reality (AR) can help to overcome current limitations in computer assisted head and neck surgery by granting "X-ray vision" to physicians. Still, the acceptance of AR in clinical applications is limited by technical and clinical challenges. We aim to demonstrate the benefit of a marker-free, instant calibration AR system for head and neck cancer imaging, which we hypothesize to be acceptable and practical for clinical use. METHODS: We implemented a novel AR system for visualization of medical image data registered with the head or face of the patient prior to intervention. Our system allows the localization of head and neck carcinoma in relation to the outer anatomy. Our system does not require markers or stationary infrastructure, provides instant calibration and allows 2D and 3D multi-modal visualization for head and neck surgery planning via an AR head-mounted display. We evaluated our system in a pre-clinical user study with eleven medical experts. RESULTS: Medical experts rated our application with a system usability scale score of 74.8 ± 15.9, which signifies above average, good usability and clinical acceptance. An average of 12.7 ± 6.6 minutes of training time was needed by physicians, before they were able to navigate the application without assistance. CONCLUSIONS: Our AR system is characterized by a slim and easy setup, short training time and high usability and acceptance. Therefore, it presents a promising, novel tool for visualizing head and neck cancer imaging and pre-surgical localization of target structures.

Facial model collection for medical augmented reality in oncologic cranio-maxillofacial surgery.

Medical augmented reality (AR) is an increasingly important topic in many medical fields. AR enables x-ray vision to see through real world objects. In medicine, this offers pre-, intra- or post-interventional visualization of "hidden" structures. In contrast to a classical monitor view, AR applications provide visualization not only on but also in relation to the patient. However, research and development of medical AR applications is challenging, because of unique patient-specific anatomies and pathologies. Working with several patients during the development for weeks or even months is not feasible. One alternative are commercial patient phantoms, which are very expensive. Hence, this data set provides a unique collection of head and neck cancer patient PET-CT scans with corresponding 3D models, provided as stereolitography (STL) files. The 3D models are optimized for effective 3D printing at low cost. This data can be used in the development and evaluation of AR applications for head and neck surgery.

A review on multiplatform evaluations of semi-automatic open-source based image segmentation for cranio-maxillofacial surgery.

BACKGROUND AND OBJECTIVES: Computer-assisted technologies, such as image-based segmentation, play an important role in the diagnosis and treatment support in cranio-maxillofacial surgery. However, although many segmentation software packages exist, their clinical in-house use is often challenging due to constrained technical, human or financial resources. Especially technological solutions or systematic evaluations of open-source based segmentation approaches are lacking. The aim of this contribution is to assess and review the segmentation quality and the potential clinical use of multiple commonly available and license-free segmentation methods on different medical platforms. METHODS: In this contribution, the quality and accuracy of open-source segmentation methods was assessed on different platforms using patient-specific clinical CT-data and reviewed with the literature. The image-based segmentation algorithms GrowCut, Robust Statistics Segmenter, Region Growing 3D, Otsu & Picking, Canny Segmentation and Geodesic Segmenter were investigated in the mandible on the platforms 3D Slicer, MITK and MeVisLab. Comparisons were made between the segmentation algorithms and the ground truth segmentations of the same anatomy performed by two clinical experts (n = 20). Assessment parameters were the Dice Score Coefficient (DSC), the Hausdorff Distance (HD), and Pearsons correlation coefficient (r). RESULTS: The segmentation accuracy was highest with the GrowCut (DSC 85.6%, HD 33.5 voxel) and the Canny (DSC 82.1%, HD 8.5 voxel) algorithm. Statistical differences between the assessment parameters were not significant (p < 0.05) and correlation coefficients were close to the value one (r > 0.94) for any of the comparison made between the segmentation methods and the ground truth schemes. Functionally stable and time-saving segmentations were observed. CONCLUSION: High quality image-based semi-automatic segmentation was provided by the GrowCut and the Canny segmentation method. In the cranio-maxillofacial complex, these segmentation methods provide algorithmic alternatives for image-based segmentation in the clinical practice for e.g. surgical planning or visualization of treatment results and offer advantages through their open-source availability. This is the first systematic multi-platform comparison that evaluates multiple license-free, open-source segmentation methods based on clinical data for the improvement of algorithms and a potential clinical use in patient-individualized medicine. The results presented are reproducible by others and can be used for clinical and research purposes.

A Marker-Less Registration Approach for Mixed Reality-Aided Maxillofacial Surgery: a Pilot Evaluation.

As of common routine in tumor resections, surgeons rely on local examinations of the removed tissues and on the swiftly made microscopy findings of the pathologist, which are based on intraoperatively taken tissue probes. This approach may imply an extended duration of the operation, increased effort for the medical staff, and longer occupancy of the operating room (OR). Mixed reality technologies, and particularly augmented reality, have already been applied in surgical scenarios with positive initial outcomes. Nonetheless, these methods have used manual or marker-based registration. In this work, we design an application for a marker-less registration of PET-CT information for a patient. The algorithm combines facial landmarks extracted from an RGB video stream, and the so-called Spatial-Mapping API provided by the HMD Microsoft HoloLens. The accuracy of the system is compared with a marker-based approach, and the opinions of field specialists have been collected during a demonstration. A survey based on the standard ISO-9241/110 has been designed for this purpose. The measurements show an average positioning error along the three axes of (x, y, z) = (3.3 ± 2.3, - 4.5 ± 2.9, - 9.3 ± 6.1) mm. Compared with the marker-based approach, this shows an increment of the positioning error of approx. 3 mm along two dimensions (x, y), which might be due to the absence of explicit markers. The application has been positively evaluated by the specialists; they have shown interest in continued further work and contributed to the development process with constructive criticism.

Free thoracodorsal, perforator-scapular flap based on the angular artery (TDAP-Scap-aa): Clinical experiences and description of a novel technique for single flap reconstruction of extensive oromandibular defects.

PURPOSE: The reconstruction of oromandibular defects can be challenging, particularly when considerable amounts of bone and soft tissues are lost. In such cases, the use of a single flap may be unsatisfactory and a concomitant free flap is needed. Here we present a chimeric, thoracodorsal perforator-scapular free flap based on the angular artery of the subscapular system (TDAP-Scap-aa) as an alternative technique for single flap reconstruction of extensive oromandibular defects. MATERIALS AND METHODS: The authors studied patients who underwent reconstructions of extensive oromandibular defects with a TDAP-Scap-aa free flap. The operative technique and the clinical experiences are described. Postoperatively, surgical complications were classified with the Clavien-Dindo Classification. RESULTS: Five male patients (59.4 ± 8.8 years) were treated with the TDAP-Scap-aa. Average sizes for harvested hard and soft tissue components, which are both included in the flap and completely independently from each other, were 10.4 ± 1.5 cm of bone length, 2.6 ± 0.3 cm of bone height, 11.6 ± 4.8 cm of skin paddle length and 8.4 ± 1.7 cm of skin paddle width. The overall mean operation time (cut-suture) was 14.6 ± 0.9 h. The postoperative follow-up was 6 months. No complications requiring surgical treatment as well as donor site nerve damages were observed. CONCLUSIONS: In comparison to other double free flaps, the TDAP-Scap-aa offers several advantages such as higher amounts of hard and soft tissues without prolonged operation times, and provides satisfying aesthetic outcomes and little donor site morbidity due to the preservation of muscle and nerve structures. Therefore, the TDAP-Scap-aa constitutes a clinically reliable alternative in extensive oromandibular defect reconstruction.

Exploit fully automatic low-level segmented PET data for training high-level deep learning algorithms for the corresponding CT data.

We present an approach for fully automatic urinary bladder segmentation in CT images with artificial neural networks in this study. Automatic medical image analysis has become an invaluable tool in the different treatment stages of diseases. Especially medical image segmentation plays a vital role, since segmentation is often the initial step in an image analysis pipeline. Since deep neural networks have made a large impact on the field of image processing in the past years, we use two different deep learning architectures to segment the urinary bladder. Both of these architectures are based on pre-trained classification networks that are adapted to perform semantic segmentation. Since deep neural networks require a large amount of training data, specifically images and corresponding ground truth labels, we furthermore propose a method to generate such a suitable training data set from Positron Emission Tomography/Computed Tomography image data. This is done by applying thresholding to the Positron Emission Tomography data for obtaining a ground truth and by utilizing data augmentation to enlarge the dataset. In this study, we discuss the influence of data augmentation on the segmentation results, and compare and evaluate the proposed architectures in terms of qualitative and quantitative segmentation performance. The results presented in this study allow concluding that deep neural networks can be considered a promising approach to segment the urinary bladder in CT images.