Design and evaluation of an AR-based thermal imaging system for planning reconstructive surgeries.

INTRODUCTION: Thermal imaging can be used for the non-invasive detection of blood vessels of the skin. However, mapping the results to the patient currently lacks user-friendliness. Augmented reality may provide a useful tool to superimpose thermal information on the patient. METHODS: A system to support planning in reconstructive surgery using a thermal camera was designed. The obtained information was superimposed on the physical object using a Microsoft HoloLens. An RGB, depth, and thermal camera were combined to capture a scene of different modalities and reconstruct a virtual scene in real time. To register the different cameras and the AR device, an active calibration target was developed and evaluated. A Vuforia marker was used to register the hologram in the virtual space. The accuracy of the projected hologram was evaluated in a laboratory setting with participants by measuring the error between the physical object and the hologram. RESULTS: The AR-based system was evaluated by 21 participants in a laboratory setting. The mean projection error is 10.3 ± 9.4 mm. The system is able to stream a three-dimensional scene with augmented thermal information in real time at 5 frames per second. The active calibration target can be used independently of the environment. CONCLUSION: The calibration target provides an easy-to-use method for the registration of cameras capturing the visible to long-infrared spectral range. The inside-out tracking of the HoloLens in combination with a Vuforia marker is not accurate enough for the intended clinical use.

Effect of the lateral wall valgisation in the treatment of patients with endocrine orbitopathy.

Orbital decompression is an established procedure used to correct exophthalmos that results from excess orbital soft tissue. This study aimed to explore a new minimally-invasive technique that features three-dimensional planning and patient-specific implants for lateral valgisation (LAVA) of the orbital wall. We analysed the outcomes of this procedure in nine endocrine orbitopathy (EO) patients (32-65 years of age with a mean clinical activity score of 4.3) who underwent this procedure between 2021 and 2022, including seven patients diagnosed with dysthyroid optic neuropathy. The impact of LAVA and wall resection on orbital areas, volumes, Hertel values, visual acuity, and new-onset diplopia was determined. Among our results, we found that LAVA and resection of 18 orbital walls resulted in significant enlargement of the orbital volume from a preoperative mean of 30.8 ± 3.5 cm3 to a mean of 37.3 ± 5.8 cm3 postoperatively (mean difference, 6.2 ± 1.8 cm3; p < 0.001); this procedure also resulted in a significant reduction in the mean Hertel value, from 28.7 ± 1.9 mm to 20.0 ± 1.9 mm (mean difference, 8.7 ± 1.9 mm; p < 0.001). The procedure resulted in visual acuity declined in three patients (33.3 %) with reductions from 0.25 to 0.125, 0.8 to 0.125, and 1.2 to 0.7, respectively. No new diplopia occurred postoperatively, however, our study included five patients with preoperative diplopia that did not improve postoperatively and required additional surgical intervention. Similarly, four patients required supplemental eyelid surgery. In conclusion, our study suggests the effects of the LAVA with the partial floor resection seems to be effective, which provides a substantially improved outcome for patients undergoing surgical treatment of EO via the use of double navigation and piezosurgical methods.

Reference Values of Cerebral Artery Diameters of the Anterior Circulation by Digital Subtraction Angiography: A Retrospective Study.

A threshold-based classification of cerebral vasospasm needs reference values for intracranial vessel diameters on digital subtraction angiography (DSA). We aimed to generate adjusted reference values for this purpose by retrospectively analyzing angiograms and potential influencing factors on vessel diameters. Angiograms of the anterior circulation were evaluated in 278 patients aged 18−81 years. The vessel diameters of 453 angiograms (175 bilateral) were gathered from nine defined measuring sites. The effect sizes of physical characteristics (i.e., body weight and height, body mass index, gender, age, and cranial side) and anatomical variations were calculated with MANOVA. Segments bearing aneurysms were excluded for the calculation of reference values. Adjusted vessel diameters were calculated via linear regression analysis of the vessel diameter data. Vessel diameters increased with age and body height. Male and right-sided vessels were larger in diameter. Of the anatomical variations, only the hypoplastic/aplastic A1 segment had a significant influence (p < 0.05) on values of the anterior cerebral artery and the internal carotid artery with a small effect size (|ω2| > 0.01) being excluded from the reference values. We provide gender-, age-, and side-adjusted reference values and nomograms of arterial vessel diameters in the anterior circulation.

The Supratrochlear Artery Sign-A New Piece in the Puzzle of Cerebral Vasospasm.

BACKGROUND: Cerebral vasospasm (CVS) after subarachnoid hemorrhage (SAH) has been extensively investigated, but the impact of collateralization remains unclear. We investigated the predictive value of collateral activation for delayed cerebral ischemia (DCI)-related infarctions and functional outcome. METHODS: Data from 43 patients with CVS (January 2014 to August 2021) were evaluated for the angiographic presence of leptomeningeal and ophthalmic collaterals (anterior falcine artery (AFA), supratrochlear artery (STA), dorsal nasal artery (DNA)) on internal carotid artery angiograms. Vasospasm-related infarction and the modified Rankin Scale (mRS) score after six months were chosen as the endpoints. RESULTS: 77% of the patients suffered from DCI-related infarctions. In 233 angiograms (at hospitalization, before spasmolysis, after six months), positive vessel signs were observed in 31 patients for STA, 35 for DNA, and 31 for AFA. The STA sign had the highest positive (84.6%) and negative (85.7%) predictive value for unfavorable outcome (mRS 4-6) in patients aged ≥50 years. DNA and AFA signs were not meaningful predictors for either endpoint. Leptomeningeal collaterals showed a positive Pearson's correlation with the STA sign in 87.5% (p = 0.038) without providing any prediction for either endpoint. CONCLUSIONS: The STA sign is associated with clinical outcome in patients with CVS after SAH aged ≥50 years, and was correlated with the occurrence of leptomeningeal collaterals.

Nimodipine vs. Milrinone - Equal or Complementary Use? A Retrospective Analysis.

Background: Cerebral vasospasm (CVS) continues to account for high morbidity and mortality in patients surviving the initial aneurysmal subarachnoid hemorrhage (SAH). Nimodipine is the only drug known to reduce delayed cerebral ischemia (DCI), but it is believed not to affect large vessel CVS. Milrinone has emerged as a promising option. Our retrospective study focused on the effectiveness of the intra-arterial application of both drugs in monotherapy and combined therapy. Methods: We searched for patients with aneurysmal SAH, angiographically confirmed CVS, and at least one intra-arterial pharmacological angioplasty. Ten defined vessel sections on angiograms were assessed before and after vasodilator infusion. The improvement in vessel diameters was compared to the frequency of DCI-related cerebral infarction before hospital discharge and functional outcome reported as the modified Rankin Scale (mRS) score after 6 months. Results: Between 2014 and 2021, 132 intra-arterial interventions (144 vascular territories, 12 bilaterally) in 30 patients were analyzed for this study. The vasodilating effect of nimodipine was superior to milrinone in all intradural segments. There was no significant intergroup difference concerning outcome in mRS (p = 0.217). Only nimodipine or the combined approach could prevent DCI-related infarction (both 57.1%), not milrinone alone (87.5%). Both drugs induced a doubled vasopressor demand due to blood pressure decrease, but milrinone alone induced tachycardia. Conclusions: The monotherapy with intra-arterial nimodipine was superior to milrinone. Nimodipine and milrinone may be used complementary in an escalation scheme with the administration of nimodipine first, complemented by milrinone in cases of severe CVS. Milrinone monotherapy is not recommended.

No Significant Bone Resorption after Open Treatment of Mandibular Condylar Head Fractures in the Medium-Term.

Open treatment of condylar head fractures (CHF) is considered controversial. In this retrospective cohort study our primary objective was therefore to assess bone resorption and remodeling as well as patients function after open treatment of CHF in a medium-term follow-up (15.1 ± 2.2 months). We included 18 patients with 25 CHF who underwent open reduction and internal fixation, between 2016 and 2021, in our analysis. The clinical data and cone-beam computed tomography (CBCT) datasets were analyzed. The condylar processes were segmented in the postoperative (T1) and follow-up (T2) CBCT scans. Volumetric and linear bone changes were the primary outcome variables, measured by using a sophisticated 3D-algorithm. The mean condylar head volume decreased non-significantly from 3022.01 ± 825.77 mm3 (T1) to 2878.8 ± 735.60 mm3 (T2; p = 0.52). Morphological alterations indicated remodeling and resorption. The pre-operative maximal interincisal opening (MIO) was 19.75 ± 3.07 mm and significantly improved to 40.47 ± 1.7 mm during follow-up (p = 0.0005). Low rates of postoperative complications were observed. Open reduction of CHF leads to good clinical outcomes and low rates of medium-term complications. This study underlines the feasibility and importance of open treatment of CHF and may help to spread its acceptance as the preferred treatment option.

Standardized Classification of Cerebral Vasospasm after Subarachnoid Hemorrhage by Digital Subtraction Angiography.

BACKGROUND: During the last decade, cerebral vasospasm after aneurysmal subarachnoid hemorrhage (SAH) was a current research focus without a standardized classification in digital subtraction angiography (DSA). This study was performed to investigate a device-independent visual cerebral vasospasm classification for endovascular treatment. METHODS: The analyses are DSA based rather than multimodal. Ten defined points of intracranial arteries were measured in 45 patients suffering from cerebral vasospasm after SAH at three time points (hospitalization, before spasmolysis, control after six months). Mathematical clustering of vessel diameters was performed to generate four objective grades for comparison. Six interventional neuroradiologists in two groups scored 237 DSAs after a new visual classification (grade 0-3) developed on a segmental pattern of vessel contraction. For the second group, a threshold-based criterion was amended. RESULTS: The raters had a reproducibility of 68.4% in the first group and 75.2% in the second group. The complementary threshold-based criterion increased the reproducibility by about 6.8%, while the rating deviated more from the mathematical clustering in all grades. CONCLUSIONS: The proposed visual classification scheme of cerebral vasospasm is suitable as a standard grading procedure for endovascular treatment. There is no advantage of a threshold-based criterion that compensates for the effort involved. Automated vessel analysis is superior to compare inter-group results in research settings.

Standardized Diagnostic Workup and Patient-Centered Decision Making for Surgery and Neck Dissection Followed by Risk-Factor Adapted Adjuvant Therapy Improve Loco-Regional Control in Local Advanced Oral Squamous Cell Carcinoma.

BACKGROUND: Standardized staging procedures and presentation of oral squamous cell carcinoma (OSCC) patients in multidisciplinary tumor boards (MDTB) before treatment and utilization of elective neck dissection (ND) are expected to improve the outcome, especially in local advanced LAOSCC (UICC stages III-IVB). As standardized diagnostics but also increased heterogeneity in treatment applied so far have not been demonstrated to improve outcome in LAOSCC, a retrospective study was initiated. METHODS: As MDTB was introduced into clinical routine in 2007, 316 LAOSCC patients treated during 1991-2017 in our hospital were stratified into cohort 1 treated before (n=104) and cohort 2 since 2007 (n=212). Clinical characteristics, diagnostic procedures and treatment modality of patients were compared using Chi-square tests and outcome analyzed applying Kaplan-Meier plots and log-rank tests as well as Cox proportional hazard regression. Propensity scores (PS) were used to elucidate predictors for impaired distant metastasis-free survival (DMFS) in PS-matched patients. RESULTS: Most patient characteristics and treatment modalities applied showed insignificant alteration. Surgical treatment included significantly more often resection of the primary tumor plus neck dissection, tracheostomy and percutaneous endoscopic gastrostomy tube use. Cisplatin-based chemo-radiotherapy was the most frequent. Only insignificant improved disease- (DFS), progression- (PFS) and event-free (EFS) as well as tumor-specific (TSS) and overall survival (OS) were found after 2006 as local (LC) and loco-regional control (LRC) were significantly improved but DMFS significantly impaired. Cox regression applied to PS-matched patients elucidated N3, belonging to cohort 2 and cisplatin-based chemo-radiotherapy as independent predictors for shortened DMFS. The along chemo-radiotherapy increased dexamethasone use in cohort 2 correlates with increased DM. CONCLUSIONS: Despite standardized diagnostic procedures, decision-making considering clear indications and improved therapy algorithms leading to improved LC and LRC, shortened DMFS hypothetically linked to increased dexamethasone use had a detrimental effect on TSS and OS.

Eyes wide shut: necessity and effect of adjunctive procedures after decompression surgery in patients with endocrine orbitopathy.

BACKGROUND: Orbital decompression surgery is frequently the last therapeutic measure in the surgical treatment of endocrine orbitopathy (EO). Additional rehabilitative and corrective surgical treatments are often used to improve the resulting eyelid stigmata, such as an increased lid aperture and scleral show. The aim of the study was to evaluate the effect of adjunctive surgical procedures after orbital decompression surgery in patients with EO. METHODS: A total of 120 orbitae from 65 patients with EO from 2010 to 2020 at a tertiary care center in Germany were retrospectively evaluated. Ocular surface area (OSA) and vertical palpebral fissures were three-dimensionally analyzed at the following stages: presurgical decompression, postsurgical decompression, and post-adjunctive surgical procedures. For the analysis of vertical palpebral fissures, predefined vertical line distances were measured on the upper and lower lids in the central, medial, and lateral pupillary regions. RESULTS: The initial OSA was 2,98 ± 0.85 cm2, and it decreased significantly after decompression surgery to 2.52 ± 0.62 cm2. After adjunct surgical procedures, OSA further decreased to 2,31 ± 0,55 cm2. Furthermore, a statistically significant reduction in all pupillary parameters was noted after each treatment step. More lid-lengthening procedures were performed on the lower lid than on the upper lid. Canthoplasty (n = 13) was the most frequently performed procedure during rehabilitation. CONCLUSION: Surgical decompression surgery improves OSA and leads to a significant reduction in lid aperture. Adjunctive surgical procedures, addressing the upper and lower lid, have a significant influence on the ongoing clinical course and contribute to a reduction in OSA.

Mixed reality in oral and maxillofacial surgery: a symbiosis of virtual and augmented reality or a pointless technological gadget?

INTRODUCTION: Mixed reality (MR) represents a new evolution in technological development that combines both virtual reality (VR) and augmented reality (AR) to create a blend of the physical and digital worlds. However, the potential role of MR in preoperative diagnostics in oral and maxillofacial surgery has not been scientifically investigated and remains generally unclear. This article presents a workflow that integrated MR in its scheme. It also evaluates the potential benefit of MR compared with its predecessors, VR and AR. MATERIAL AND METHODS: MR technology was used to plan the surgical treatment of a clinical case with an extensive tumor of the left maxilla. A workflow proposal incorporating both the surgeon and radiation oncologist is presented based on this experience. A total of 10 examiners rated the usability and applicability of MR for daily routines. RESULTS: MR showed good results during preoperative planning for a surgically extensive case in terms of displaying 3D structures and enhancing the physical and virtual interactions among the examiners. Previously described drawbacks of other VR/AR applications such as nausea and motion sickness were not observed with MR. However, MR seems to lack intraoperative usability, which is a drawback. CONCLUSION: MR shows great potential in improving the preoperative assessment of 3D DICOM datasets and thus facilitating diagnostic measures. However, further improvements should be made to implement an MR workflow and incorporate it into the clinical treatment planning tree.

Improved access in minimally invasive temporomandibular joint surgery through a novel endaural template.

BACKGROUND: Digitally designed surgical templates for minimally invasive temporomandibular joint (TMJ) surgery (MITMJS) are a promising tool for improving the safety of these procedures. Given the TMJ anatomy, the template fitting and intraoperative overview are the most important issues for a safe surgery. This article is a technical advance article that aims to describe an endaural surgical template based on the Moses approach as a possible solution in TMJ surgery. METHODS: Three patients with internal derangement were treated with the guidance of a MITMJS template based on cone beam computed tomography (CBCT) and a surface imprint of the periauricular region. None of the patients needed an additional open surgical procedure. Fitting of the templates was judged in terms of position and rotational stability. Surgical side effects and complications were recorded for each patient. RESULTS: The template design and clinical use were satisfactory for MITMJS. The templates showed satisfying fit and good visibility. In the study cohort, no bleeding, facial nerve injury, or other complications occurred after the procedure, and no visible scars were noted postoperatively. CONCLUSION: Our feasibility report on template-guided MITMJS shows a promising new application of templates. It points to improved access in arthroscopy or arthrocentesis of TMJ surgery through endaural access with an increased level of safety during surgery.

Impact of COVID-19 on Oral and Maxillofacial Surgery: Preliminary Results After the Curfew.

INTRODUCTION: The COVID-19 pandemic affects basic health care in maxillofacial surgery (MFS) due to the shift in resources and the change in patient disorders treated during the pandemic. This paper aims to elucidate the medical and financial consequences driven by the measures for COVID-19 treatment in a tertiary care centre. MATERIAL AND METHODS: To evaluate the impact of pandemic measures on daily routines of MFS, the surgical schedule during the first 2 weeks after the onset of the curfew (March 2020), and to compare it with the schedule of the same period of time 1 year earlier. Furthermore, postponed surgeries as well as cancelled follow-ups are listed. The loss of earning was calculated as well as the number and kind of postponed procedures. RESULTS: The number of surgeries decreased by 45% (n = 163 in 2019 vs n = 89 in 2020), and the duration of the surgeries decreased from 94.2 minutes to 62.1 minutes. No elective surgeries, such as implantology, aesthetic surgery, or orthognathic surgery, took place. Furthermore, also trauma cases decreased from 9 to 3 cases. Considering all variables, the financial loss can be calculated as approximately 100,256.50 Euros per week. CONCLUSION: The impact of COVID-19 on MFS is certainly of medical and economic importance and is related to the duration of the pandemic.

Quality of life in patients with oral hard or soft tissue defects after reconstructive microsurgery.

With current advances in medicine, many surgical methods have emerged for the reconstruction of soft and hard tissue defects of the head and neck. Current literature provides only a limited amount of evidence in studies addressing differences in quality of life for specific therapeutic measures in microvascular reconstruction. The validated University of Washington quality of life questionnaire version 4 (UW-QoL v4), a distress thermometer, and two questions addressing donor-site morbidity were sent to 134 patients at a tertiary care centre. All participants had undergone a type of microvascular reconstructive surgery of the head and neck. They were distributed into three groups according to the defect and type of treatment: defects reconstructed by soft-tissue microvascular tissue transfer, defects involving the hard tissue and treated by alloplastic reconstruction, and hard tissue defects receiving microvascular osseous reconstruction. A total of 82 patients completed the questionnaire in full and returned it. Patients from all the groups showed improved distress thermometer values postoperatively. Those who underwent osseous microvascular reconstruction had better functional items than those who had alloplastic reconstruction plates. Donor-site morbidity was rated low in all groups. Microvascular osseous reconstructive surgery might help to improve functional outcomes in patients with osseous defects more than alloplastic reconstruction.

The ideal auricular protrusion - An interactive perceptual pilot study.

PURPOSE: Excessive ear protrusion (prominauris) can negatively affect facial appearance. Because the concept of an ideal auriculocephalic angle is controversial, however, it is difficult to define when an obtrusive auricle requires surgical intervention. It is often assumed that angles exceeding 30° require corrective surgery. However, little is known about public perception of ear protrusion. This study aimed to assess perceptions of different degrees of auricular protrusion. MATERIALS AND METHODS: We conducted an interactive panel survey. Male and female evaluators assessed digitally processed cloned images of a male and female model that depicted various ear protrusions ranging from 0° to 90°. Predictor variables were the sex of the evaluator, the sex of the clone and the extent of auricular protrusion. The outcome variable was the overall attractiveness of auricular appearance. RESULTS: Forty-four evaluators (students of dental medicine, mean age 25.43 years) participated in the study: 22 women and 22 men. The study results revealed sexual dimorphism, with the attractiveness of corresponding male and female clones rated differently. Male evaluators favoured female ear positions that fitted closer to the head; preferred alignments for female clones were: 18° (Mean) ± 9.38° (SD), p = 0.006; for male clones: 30° ± 7.94°, p = 0.003. Ear protrusion starts to negatively affect aesthetic appearance for male evaluators at positions of 42° ± 4.87° (female clone) and 54° ± 8.22° (male clone), p = 0.001. The panel of evaluators agreed to perceive angles of 21-24° ± 8.10° (female clones), ± 8.33° (male clones), as the ideal degree of protrusion in both sexes (p = 0.158). CONCLUSION: In this study, perception of ear appearance depended on the sex of both the evaluator and the clone being assessed. Obtrusive ears were more readily accepted in male faces than in female ones. Nevertheless, the overall panel perception shows a preference for rather close fitting, unobtrusive ear alignments. For planning of corrective ear surgery, a target angle of approximately 22° can be considered as a desirable result.

Flow Chart for Reconstructive Head and Neck Surgery in Composite Soft and Hard Tissue Defects.

INTRODUCTION: Virtual planning of reconstructive surgical procedures in patients with osseous and composite defects in the head and neck region is becoming increasingly a state of the art modality. However, computational algorithms lack the capability of planning the involved soft tissue and vascular pedicle position. The authors present a flow-chart to solve this problem in the reconstruction of defects of the upper and lower jaw. MATERIAL AND METHODS: Clinical records from 2013 to 2018 from a tertiary care center were screened for patients undergoing osseous reconstruction in the head and neck region. A flow-chart considering soft tissue positioning and the anatomical course of the vascular pedicle was assessed in consideration of the defect and donor-site. RESULTS: A total of 81 osseous and composite microvascular reconstructive procedures have been conducted. Defects of the lower jaw were the most common (n = 61). The free fibula flap was the most common reconstructive measure and showed a wide versatility of surgical options to reconstruct these defects. The flow charts were assessed accordingly in these procedures. CONCLUSION: Soft tissue and vascular pedicle positioning can be planned pre-operatively by the use of virtual planning and should be considered as an enhancement tool to the already existing computational algorithms of planning hard tissue reconstruction.

Donor-site morbidity after harvesting of radial forearm free flaps-comparison of vacuum-assisted closure with conventional wound care: A randomized controlled trial.

INTRODUCTION: Radial forearm free flaps (RFFF) are often used to replace tissue removed in head and neck surgery. In recent years, many attempts have been made to reduce donor-site morbidity and to prevent common complications such as infection, skin-graft necrosis, tendon exposure and subsequent impairment of hand function. One promising option is the use of vacuum-assisted-closure wound therapy (VAC). The objective of this study was to evaluate the effectiveness of VAC compared with a conventional bolster dressing (CBD). MATERIAL AND METHODS: A randomized controlled trial was enrolled. Our study was prospective in design and included patients with a skin-grafted forearm defect after harvesting of RFFF. Patients who met the inclusion criteria were randomly assigned into two study arms. The predictor variable was the type of wound therapy (VAC therapy compared with CBD) and the outcome variables were (1) the size of the wound area, (2) wrist movement and (3) grip strength. Outcome variables were assessed 12 days, three weeks and eight weeks after surgery. RESULTS: Fifty patients (33 males, mean age 61.7 years [SD 15.5]; 17 females, mean age 54.7 years [SD 10.5]) were included consecutively in the study. Patients in the VAC group experienced a faster postsurgical reduction of wound area and had better wrist movement; nonetheless, the differences between the VAC group and CBD group did not reach statistical significance. In contrast, the recovery of postsurgical grip strength was significantly faster in the VAC group. CONCLUSIONS: Our study failed to prove that VAC therapy is significantly superior to CBD for all the variable studied. Because VAC therapy has some positive effects, however, we recommend further development of this negative-pressure wound treatment, rather than the termination of its use.

Automatic detection of perforator vessels using infrared thermography in reconstructive surgery.

PURPOSE: Knowing the location of the blood vessels supplying the skin and subcutaneous tissue is a requirement during the planning of tissue transfer in reconstructive surgery. Commonly used imaging techniques such as computed tomography angiography and indocyanine green angiography expose the patient to radiation or a contrast agent, respectively. Infrared thermal imaging was evaluated with success as a non-invasive alternative. To support the interpretation of thermograms, a method to automatically detect the perforators was developed and evaluated. METHODS: A system consisting of a thermal camera, a PC and custom software was developed. The temperature variations of the skin surface were analysed to extract the perforator locations. A study was conducted to assess the performance of the algorithm by comparing the detection results of the algorithm with manually labelled thermal images by two clinicians of the deep inferior epigastric perforator flap of 20 healthy volunteers. RESULTS: The F measure, precision and recall were used to evaluate the system performance. The median F measure is 0.833, the median precision is 0.80, and the median recall is 0.907. CONCLUSION: The results of this study showed that it is possible to automatically and reliably detect the skin perforators in thermograms despite their weak temperature signature. Infrared thermal imaging is a non-invasive and contactless approach suitable for intraoperative use. Combined with a computer-assisted tool for the automatic detection of perforator vessels, it is a relevant alternative intraoperative imaging method to the standard indocyanine green angiography.

Upper-eyelid weight implants for patients with lagophthalmos-comparison of rigid and flexible implants.

INTRODUCTION: For treatment of lagophthalmos, metallic weight implants can be inserted in the upper eyelid to aid eyelid closure. Rigid and flexible implants are available. The objective of this study was to investigate the effect of implant type and patient variables on the survival of lid load implants. MATERIALS AND METHODS: Forty-four patients with lagophthalmos were recruited to undergo upper-eyelid weight implantation. The predictor variable was type of implant inserted (rigid or flexible). The outcome variable was survival of the inserted implant (survival or extrusion). Other study variables were demographic data (age, gender), implant features (material, weight), and other conditions, such as history of radiation. An NMLE test was used to compare implant survival, depending on implant type (flexible versus rigid). Other variables were analysed by use of a χ2 test. RESULTS: Forty-four participants were recruited, 29 female (65.9%) and 15 male (34.1%). Forty-six implants (23 rigid implants, 50.0%; 23 flexible implants, 50.0%) were inserted (bilateral implantation in two patients). The average weight of implants used was 1.76 g (range 1.4-2.2 g). One to two years after surgery, average vertical aperture (eyelid gap) for the closed eye was 0.65 mm (range 0-4 mm). Incidence of extrusion was 15.2% (one in the rigid implant group, 2.2%; six in the flexible implant group, 13.0%). Incidence of extrusion was significantly higher for flexible implants than for rigid implants (p = 0.0273). CONCLUSIONS: The study results suggest that flexible implants are more likely to perforate the skin. The assumed advantages of the expensive chain lid weight must, therefore, be re-evaluated.

Rare anatomical variation of the brachiocephalic trunk encountered in tracheostomy.

Tracheostomy is a common procedure in head and neck surgery and emergency medicine to secure a patent airway. Surgeons should always be aware of anatomical variants of the branches of the aortic arch, which could lead to life-threatening complications. Open tracheostomy is the safest emergency procedure.