Use of Integra® on avascular tissue.

Integra® (Integra LifeSciences) is a well-known dermal regeneration template used in partial and full-thickness wound reconstruction. It can be applied directly on to vascular tissue to create a bed for a skin graft, which is often placed in a second surgery. We present our experience of its novel use in oral and maxillofacial surgery patients, using it directly on bone and cartilage (avascular tissue) without further skin grafting. Patients who required full-thickness excision of lesions down to bone or cartilage and who were treated using Integra® were included. After scalp or ear lesion resection, the collagenous dermal layer of Integra® was placed directly on to bone or cartilage and, along with its outer silicone epidermal layer, secured to the defect with absorbable sutures and a bolster dressing. The wounds were kept dry for 14 days, at which point the dressing and silicone were removed and patients continued regular wound care. Seventeen patients were included, 15 of whom had squamous cell carcinoma. One was lost to follow up. The rest achieved complete healing of the defect. Histology showed epidermis developing on the Integra® surface and at one year, the appearance of normal scarred skin. This novel approach could redefine the uses of Integra®, avoiding the need for free-flap surgery or skin grafting when reconstructing large defects. Further resection of close margins or recurrence is easier after reconstruction using dermal regeneration material than after reconstruction with a local or free flap.

Augmented reality presentation of the extracranial facial nerve: an innovation in parotid surgery.

Surgeons used to be unaware of the facial nerve's position during parotid surgery. Now, with special magnetic resonance imaging (MRI) sequences, it can be located and converted into a 3D model displayed on an augmented reality (AR) device for surgeons to study and manipulate. This study explores the accuracy and usefulness of the technique for the treatment of benign and malignant parotid tumours. A total of 20 patients with parotid tumours had 3-Tesla MRI scans, and their anatomical structures were segmented using Slicer software. The structures were imported into a Microsoft HoloLens 2® device, displayed in 3D, and shown to the patient for consent. Intraoperative video recording was used to record the position of the facial nerve in relation to the tumour. The predicted path of the nerve taken from the 3D model was combined with surgical observation and video recording in all cases. The imaging proved to have application in both benign and malignant disease. It also improved the process of informed patient consent. Three-dimensional MRI imaging of the facial nerve within the parotid gland and its display in a 3D model is an innovative technique for parotid surgery. Surgeons can now see the nerve's position and tailor their approach to each patient's tumour, providing personalised care. The technique eliminates the surgeon's blind spot and is a significant advantage in parotid surgery.

A training tool for clinicians in segmenting medical images to make 3D models.

Introduction: 3D models produced from medical imaging can be used to plan treatment, design prosthesis, teach and for communication. Despite the clinical benefit, few clinicians have experience of how 3D models are produced.This is the first study evaluating a training tool to teach clinicians to produce 3D models and reporting the perceived impact on their clinical practice. Method: Following ethical approval, 10 clinicians completed a bespoke training tool, comprising written and video material alongside online support. Each clinician and 2 technicians (included as control) were sent 3 CT scans and asked to produce 6 fibula 3D models using an open-source software (3Dslicer). The produced models were compared to those produced by the technicians using Hausdorff distance calculation. Thematic analysis was used to study the post-intervention questionnaire. Results: The mean Hausdorff distance between the final model produced by the clinicians and technicians was 0.65mm SD0.54mm. The first model made by clinicians took a mean time of 1hr 25mins and the final model took 16:04mins (5:00-46:00mins). 100% of learners reported finding the training tool useful and will employ it in future practice. Discussion: The training tool described in this paper is able to successfully train clinicians to produce fibula models from CT scans. Learners were able to produce comparable models to technicians within an acceptable timeframe. This does not replace technicians. However, the learners perceived this training will allow them to use this technology in more cases, with appropriate case selection and they appreciate the limits of this technology.

Systematic review of techniques used to validate the registration of augmented-reality images using a head-mounted device to navigate surgery.

Augmented-reality (AR) head-mounted devices (HMD) allow the wearer to have digital images superposed on to their field of vision. They are being used to superpose annotations on to the surgical field akin to a navigation system. This review examines published validation studies on HMD-AR systems, their reported protocols, and outcomes. The aim was to establish commonalities and an acceptable registration outcome. Multiple databases were systematically searched for relevant articles between January 2015 and January 2021. Studies that examined the registration of AR content using a HMD to guide surgery were eligible for inclusion. The country of origin, year of publication, medical specialty, HMD device, software, and method of registration, were recorded. A meta-analysis of the mean registration error was conducted. A total of 4784 papers were identified, of which 23 met the inclusion criteria. They included studies using HoloLens (Microsoft) (n = 22) and nVisor ST60 (NVIS Inc) (n = 1). Sixty-six per cent of studies were in hard tissue specialties. Eleven studies reported registration errors using pattern markers (mean (SD) 2.6 (1.8) mm), and four reported registration errors using surface markers (mean (SD) 3.8 (3.7) mm). Three studies reported registration errors using manual alignment (mean (SD) 2.2 (1.3) mm). The majority of studies in this review used in-house software with a variety of registration methods and reported errors. The mean registration error calculated in this study can be considered as a minimum acceptable standard. It should be taken into consideration when procedural applications are selected.

Extracapsular dissection (ECD) and extended ECD: description of the technique and outcome of treatment.

Over the last two decades the senior author has exclusively applied the technique of extracapsular dissection (ECD) and extended ECD to treat discrete, apparently benign parotid tumours. This article describes both techniques and evaluates their application. Simple principles are described to anticipate unexpected malignant tumours and manage lumps safely by wide excision. A retrospective analysis of 97 consecutive patients with discrete, apparently benign parotid lumps is presented. The tumours were classified using the European Salivary Gland Society (ESGS) classification for benign tumours of the parotid gland. The ECD or extended ECD technique was employed irrespective of tumour site or size. A review of patients was carried out after a minimum of six months post surgery by two independent clinicians. The mean (range) hospital stay was one (0-4) night (median 1). Complications were both modest and transient. The temporary facial nerve injury rate was 5/97 (6%). Other complications included haematoma (n=2), sialocele (n=2), and first-bite syndrome (n=2). Independent review post surgery demonstrated a mean Sunnybrook facial grading system score of 98/100 and a mean Stony Brook scar assessment score of 4.5/5. In this series 5/97 (5%) of discreet mobile lumps concealed a low-grade salivary cancer. Experience with the application of ECD in conjunction with its extended form in 97 consecutive patients with discrete parotid lumps is described. The technique is amenable to all parotid lumps, is not restricted by site or size, and has shown minimal morbidity. The risk of recurrent disease could not be addressed.

Recent advances in the histopathological assessment of salivary disease.

BACKGROUND: Salivary gland disease includes a wide range of unique and rare conditions that are treated by ear, nose and throat (ENT), oral and maxillofacial surgeons (OMFS) and oral medicine specialists. Histopathological diagnosis is pivotal to making a diagnosis and treatment planning. There is a vast range of conditions and controversies in the histopathological assessment of salivary gland diseases. Most colleagues in oral pathology and oral medicine work closely with the OMFS but might have missed some of the recent articles published by the speciality. METHODS: We reviewed articles thought to be relevant to oral medicine and pathology specialists published over an 8-year period between 2012 and 2019 in the leading British Journal of Oral and Maxillofacial Surgery (BJOMS). RESULTS: A total of 44 published articles relating to the histopathology of salivary glands disease were selected. Papers were published on population studies, benign and malignant tumours, sialadenitis, metastasis to the parotid gland and cytology. The publication type and numbers published were as follows: review (n = 9), meta-analysis/randomised controlled study (n = 1), retrospective study (n = 10) and case report/technical notes (n = 23). CONCLUSIONS: The greatest proportion of publications published in BJOMS were case reports. This emphasises the paucity of consensus and the need for development in this field. Salivary gland disease remains an area with many controversies and would benefit from further research.

A review of recent advances in histopathological assessment of head and neck squamous cell carcinoma.

Squamous cell carcinoma (SCC) is the most common non-cutaneous head and neck (H&N) malignancy. Referrals for suspected SCC are seen by oral and maxillofacial surgery (OMFS) surgeons and represent the bulk of 2-week wait referrals. The diagnosis and treatment of SCC is heavily influenced by national and international guidelines. The majority of research and funding is directed towards this condition. This has led to continuous changes to update these guidelines. However, there remain areas of controversy and conflicting evidence. This article summarises articles pertinent to pathologists between 2016 and 2018 published in the leading British OMFS journal. A total of 22 published articles relating to the histopathology of non-cutaneous H&N SCC were selected.

Outcomes of treatment of fractures of the frontal sinus: review from a tertiary multispecialty craniofacial trauma service.

There are no agreed national guidelines for the treatment of fractures of the frontal sinus and the naso-orbitoethmoid complex. The Oxford University Hospitals Craniofacial Trauma unit was set up five years ago as a joint oral and maxillofacial, ENT, and neurosurgical service, and we present our experience to date in the treatment of patients with such fractures. The study includes 91 patients with data collected from a prospective database. Patients underwent cranialisation if they met the criteria of persistent leak of cerebrospinal fluid (CSF), displaced fracture of the posterior wall or obstruction of the nasofrontal outflow tract. The mean follow-up time was 42 months (range 1-10 years). Three groups of patients were analysed. Group 1 met the criteria for, and were treated by, cranialisation (n=50). Group 2 met the criteria for cranialisation, but were treated conservatively because of coexisting conditions (n=8). Group 3 did not match the criteria for treatment, and were managed conservatively (n=33). The numbers of patients with complications or who required further operation were: group 1 (4/50), group 2 (3/8), and group 3 (3/33). There were significantly fewer complications among those patients who met the operative criteria and were treated by cranialisation than among those treated conservatively (p=0.04). These outcomes from one dedicated multispecialist craniofacial trauma unit in the UK may help surgeons who care for patients with this specific group of injuries. Our morbidity was in keeping with published figures.

The routine use of tranexamic acid in hip and knee replacements.

PURPOSE: Our aim was to determine whether the administration of intravenous tranexamic acid is a safe and effective means of reducing blood loss associated with hip and knee replacement surgery. METHOD: Sequential cohort study analysing hemoglobin titers, transfusion rates, and the occurrence of venous thromboembolism in patients undergoing hip and knee replacements with and without the administration of tranexamic acid at the time of induction. Finally, a cost benefit analysis was performed. RESULTS: Two hundred and seventy-three patients were included in our study. We demonstrated that 1 gram of tranexamic acid administered intravenously at the time of induction significantly reduces operative blood loss and transfusion rates (p < 0.05). Moreover, the use of tranexamic acid reduces the costs associated with surgery. CONCLUSIONS: The administration of 1 gram of intravenous tranexamic acid is a safe and effective means of reducing operative blood loss and blood transfusion rates in patients undergoing hip and knee replacements.

The effect of anesthetic technique on recovery after orthognathic surgery: a retrospective audit.

We audited the recovery characteristics of 51 patients who had undergone orthognathic maxillofacial surgery at a single center. Patients whose anesthesia had been maintained with intravenous propofol and remifentanil (n  =  21) had significantly higher pain scores during the first 4 hours after surgery than those whose anesthesia was maintained with volatile inhalational agents and longer-acting opioids (n  =  30) (P  =  .016). There was a nonsignificant trend towards shorter recovery times in the former group, while there were no differences in early postoperative opioid usage, hemodynamic parameters, or postoperative nausea and vomiting . Given that our data were collected retrospectively and without the ability to control for potential confounders, we interpret the results with caution. Notwithstanding these limitations, we believe this is the first report comparing the effects of different opioid-based anesthetic regimens on early recovery from orthognathic surgery, and we believe this report may be used as the starting point for a controlled study.

Review of evidence for the use of steroids in orthognathic surgery.

Primarily, steroids are used routinely in orthognathic surgery to reduce swelling, but there is no nationally accepted regimen for the use of glucocorticoids in the UK. This article examines the evidence base for the use of steroids to reduce swelling, nausea, vomiting, and pain, and looks at evidence of the ratio of risks:benefits in orthognathic surgery and related publications. Evidence supports their use preoperatively, but the timing of this and their postoperative use may be contentious. The current regimens are associated with little morbidity and low cost. A well designed multi-centre study whose design would allow objective measures of swelling is required to resolve the areas of debate.