Assessment of effectiveness and safety of thrombolytic therapy to pulmonary emboli by endobronchial ultrasound-guided transbronchial needle injection

Objective

Endobronchial ultrasound-guided transbronchial needle injection (EBUS-TBNI) may effectively treat acute pulmonary embolisms (PEs). Here, we assessed the effectiveness of clot dissolution and safety of tissue plasminogen activator (t-PA) injection using EBUS-TBNI in a 1-week survival study of a porcine PE model.

Methods

Six pigs with bilateral PEs were used: 3 for t-PA injection using EBUS-TBNI (TBNI group) and 3 for systemic administration of t-PA (systemic group). Once bilateral PEs were created, each 25 mg of t-PA injection using EBUS-TBNI for bilateral PEs (a total of 50 mg t-PA) and 100 mg of t-PA systemic administration was performed on day 1. Hemodynamic parameters, blood tests, and contrast-enhanced computed tomography scans were carried out at several time points. On day 7, pigs were humanely killed to evaluate the residual clot volume in the pulmonary arteries.

Results

The average of percent change of residual clot volumes was significantly lower in the TBNI group than in the systemic group (%: systemic group 36.6 ± 22.6 vs TBNI group 9.6 ± 6.1, P < .01) on day 3. Considering the elapsed time, the average decrease of clot volume per hour at pre-t-PA to post t-PA was significantly greater in the TBNI group than in the systemic group (mm3/hour: systemic 68.1 ± 68.1 vs TBNI 256.8 ± 148.1, P < .05). No hemorrhage was observed intracranially, intrathoracically, or intraperitoneally on any contrast-enhanced computed tomography images.

Conclusions

This study revealed that t-PA injection using EBUS-TBNI is an effective and safe way to dissolve clots.

High-'n'-dry? A comparison of cannabis and alcohol use in drivers presenting to hospital after a vehicular collision

DESIGN

This was a prospective observational study.

BACKGROUND AND AIMS

The characteristics of cannabis-involved motor vehicle collisions are poorly understood. This study of injured drivers identifies demographic and collision characteristics associated with high tetrahydrocannabinol (THC) concentrations.

SETTING

The study was conducted in 15 Canadian trauma centres between January 2018 and December 2021.

CASES

The cases (n = 6956) comprised injured drivers who required blood testing as part of routine trauma care.

MEASUREMENTS

We quantified whole blood THC and blood alcohol concentration (BAC) and recorded driver sex, age and postal code, time of crash, crash type and injury severity. We defined three driver groups: high THC (THC ≥ 5 ng/ml and BAC = 0), high alcohol (BAC ≥ 0.08% and THC = 0) and THC/BAC-negative (THC = 0 = BAC). We used logistic regression techniques to identify factors associated with group membership.

FINDINGS

Most injured drivers (70.2%) were THC/BAC-negative; 1274 (18.3%) had THC > 0, including 186 (2.7%) in the high THC group; 1161 (16.7%) had BAC > 0, including 606 (8.7%) in the high BAC group. Males and drivers aged less than 45 years had higher adjusted odds of being in the high THC group (versus the THC/BAC-negative group). Importantly, 4.6% of drivers aged less than 19 years had THC ≥ 5 ng/ml, and drivers aged less than 19 years had higher unadjusted odds of being in the high THC group than drivers aged 45-54 years. Males, drivers aged 19-44 years, rural drivers, seriously injured drivers and drivers injured in single-vehicle, night-time or weekend collisions had higher adjusted odds ratios (aORs) for being in the high alcohol group (versus THC/BAC-negative). Drivers aged less than 35 or more than 65 years and drivers involved in multi-vehicle, daytime or weekday collisions had higher adjusted odds for being in the high THC group (versus the high BAC group).

CONCLUSIONS

In Canada, risk factors for cannabis-related motor vehicle collisions appear to differ from those for alcohol-related motor vehicle collisions. The collision factors associated with alcohol (single-vehicle, night-time, weekend, rural, serious injury) are not associated with cannabis-related collisions. Demographic factors (young drivers, male drivers) are associated with both alcohol and cannabis-related collisions, but are more strongly associated with cannabis-related collisions.

[Long term outcomes of botulinum toxin injections in infantile esotropia]

PURPOSE

To evaluate long terms outcomes of botulinum toxin in infantile esotropia by measuring the amount of microtropia 24 months after injection. Secondary purpose was to identify predictive factors of microtropia.

METHODS

A retrospective, single-center study was performed at the university medical center in Bordeaux between 2001 and 2018, including all patients with infantile esotropia greater than 20 D. All patients received 5 or 7,5 IU of botulinum toxin A in each medial rectus, once or twice depending on the angle of deviation after the first injection and after wearing full optical correction at least two months. We noted the angle at 1, 6, 12 and 24 months, the occurrence of any complications and the need for later strabismus surgery. The primary endpoint was the achievement of a microtropia less than 8 diopters (D) at 24 months post-injection. We evaluated the predictive factors for microtropia with a Fischer's test.

RESULTS

We included 30 patients with esotropia greater than 20 D. The mean follow-up after injection was 48 months ±30. The mean age was 16.24 months (7-29 months) with a female predominance in the population (SR=0.43). The mean pre-injection deviation was 41.25±12.17 D. The majority of patients were mildly (40%) or moderately (40%) hyperopic. At 24 months, 46.7% microtropias were obtained (95% CI: 28.9%-64.5%). The change in mean angle at 1, 6, 12 and 24 months post-injection was -8.57±25.21 D; 14.48±13.40 D; 18.38±12.07 D and 21.23±14.97 D, respectively. No factors were predictive of microtropia. Of the 30 children, 3 had transient ptosis requiring strips and 12 showed an exotropia at 1 month. All complications were self-limited and without consequences. 3 children had a second injection of botulinum toxin, which in 2/3 of the cases resulted in a long-lasting microtropia. 26.7% (n=8) of the children underwent secondary surgery. Obtaining a microtropia 24 months after injection statistically significantly reduced the need for secondary strabismus surgery: 92.9% P=0.039% CI 95% (0.002; 1.0606).

CONCLUSION

Botulinum toxin appears to be a less invasive and more conservative alternative to surgery in children with infantile esotropia. In 46.7% of cases, microtropia is achieved. An improvement was noted in 90% (n=27) of the children with a reduction of half (21.23 D) of the mean post-injection angle at 24 months. When effective, it significantly reduces the need for secondary surgery.

Developing a virtual reality simulation system for preoperative planning of thoracoscopic thoracic surgery

Background

Video-assisted thoracoscopic surgery (VATS) has become a standard approach for the treatment of lung cancer. However, its minimally invasive nature limits the field of view and reduces tactile feedback. These limitations make it vital that surgeons thoroughly familiarize themselves with the patient’s anatomy preoperatively. We have developed a virtual reality (VR) surgical navigation system using head-mounted displays (HMD). The aim of this study was to investigate the potential utility of this VR simulation system in both preoperative planning and intraoperative assistance, including support during thoracoscopic sublobar resection.

Methods

Three-dimensional (3D) polygon data derived from preoperative computed tomography data was loaded into BananaVision software developed at Colorado State University and displayed on an HMD. An interactive 3D reconstruction image was created, in which all the pulmonary structures could be individually imaged. Preoperative resection simulations were performed with patient-individualized reconstructed 3D images.

Results

The 3D anatomic structure of pulmonary vessels and a clear vision into the space between the lesion and adjacent tissues were successfully appreciated during preoperative simulation. Surgeons could easily evaluate the real patient’s anatomy in preoperative simulations to improve the accuracy and safety of actual surgery. The VR software and HMD allowed surgeons to visualize and interact with real patient data in true 3D providing a unique perspective.

Conclusions

This initial experience suggests that a VR simulation with HMD facilitated preoperative simulation. Routine imaging modalities combined with VR systems could substantially improve preoperative planning and contribute to the safety and accuracy of anatomic resection.

Plant-Based Dietary Patterns, Body Composition, Muscle Strength and Function in Middle and Older Age: A Systematic Review

BACKGROUND

Sarcopenia is prevalent in middle-aged and older adults. A plant-based diet may be linked to changes in body composition and musculoskeletal health.

OBJECTIVE

This systematic review aimed to investigate the effects of plant-based dietary patterns on the body composition, muscle strength and function in middle-aged and older adults. PRISMA guidelines were followed.

METHOD

A systematic search was completed on databases including MEDLINE, Embase, Global Health, PREMEDLINE, Cochrane library, CINAHL and Scopus on articles published until 1st March 2019. Search terms included 'middle-aged', 'older adult', 'plant-based diet' and 'muscle strength'. Title and abstract screening were conducted on 1,868 publications after deduplication. Sample size, subject characteristics, recruitment, inclusion and exclusion criteria, dietary measures, health outcome measures, statistical results and confounders were sorted by author, study type, year and country. The quality of evidence of extracted data was assessed using the Scottish Intercollegiate Guidelines Network (SIGN) and the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) tools.

RESULTS/CONCLUSIONS

17 papers were included from 31 articles selected for full review. The majority of the studies were cross-sectional studies (n = 9) and RCTs (n = 6).The remaining studies were cohort studies. Positive associations were found between plant-based dietary patterns; negative association with body composition; and inconclusive association with muscle function. However, further studies are needed to improve the understanding.

Comparing Contour Restoration of Mandibular Body Defects With Fibula, Iliac Crest, and Scapular Tip Flaps: A Conformance Virtual Study

PURPOSE

The purpose of this study was to determine which of the most commonly used flaps restore contour more accurately in mandibular body reconstructions using conformance analyses and virtual measurements.

METHODS

Using normal computed tomography (CT) scans and a 3D software, mandibular body defects were virtually created. "Single shot" and osteotomized fibula flaps (SS-FF and O-FF), iliac crest flaps (ICF) and scapular tip flaps (STF) were digitally harvested and coregistered to reconstruct those defects. Conformance analyses were performed by calculating the root mean square (RMS) for overall and contour conformance.

RESULTS

Ten patients normal CT scans were included. The STF demonstrated improved overall conformance compared with the ICF, the SS-FF and the O-FF (RMS = 2.03 mm vs 4.53 mm vs 2.76 vs 2.37 mm, respectively; p<.001). Similar trends were seen for contour conformance in STF compared with the ICF and the SS-FF (RMS = 2.48 mm vs 4.50 mm vs 3.28 mm, respectively), whereas the O-FF performed better than STF (RMS = 1.85 mm vs 2.48 mm; p<.001).

CONCLUSIONS

The osseous component of the STF resembles the mandibular body more accurately than the one in the ICF and FF without the need for an osteotomy. Future clinical studies can help to elucidate the clinical impact of these virtual findings.

In situ tissue pathology from spatially encoded mass spectrometry classifiers visualized in real time through augmented reality

Integration between a hand-held mass spectrometry desorption probe based on picosecond infrared laser technology (PIRL-MS) and an optical surgical tracking system demonstrates in situ tissue pathology from point-sampled mass spectrometry data. Spatially encoded pathology classifications are displayed at the site of laser sampling as color-coded pixels in an augmented reality video feed of the surgical field of view. This is enabled by two-way communication between surgical navigation and mass spectrometry data analysis platforms through a custom-built interface. Performance of the system was evaluated using murine models of human cancers sampled in situ in the presence of body fluids with a technical pixel error of 1.0 ± 0.2 mm, suggesting a 84% or 92% (excluding one outlier) cancer type classification rate across different molecular models that distinguish cell-lines of each class of breast, brain, head and neck murine models. Further, through end-point immunohistochemical staining for DNA damage, cell death and neuronal viability, spatially encoded PIRL-MS sampling is shown to produce classifiable mass spectral data from living murine brain tissue, with levels of neuronal damage that are comparable to those induced by a surgical scalpel. This highlights the potential of spatially encoded PIRL-MS analysis for in vivo use during neurosurgical applications of cancer type determination or point-sampling in vivo tissue during tumor bed examination to assess cancer removal. The interface developed herein for the analysis and the display of spatially encoded PIRL-MS data can be adapted to other hand-held mass spectrometry analysis probes currently available.

Integration between a hand-held mass spectrometry desorption probe based on picosecond infrared laser technology (PIRL-MS) and an optical surgical tracking system demonstrates in situ tissue pathology from point-sampled mass spectrometry data.

Endobronchial Ultrasound-Guided Radiofrequency Ablation of Lung Tumors and Mediastinal Lymph Nodes: A Preclinical Study in Animal Lung Tumor and Mediastinal Adenopathy Models

Radiofrequency ablation (RFA) can be a therapeutic option in medically inoperable lung cancer patients. In this study, we evaluated a prototype bipolar RFA device applicator that can be deployed from a standard endobronchial ultrasound (EBUS) bronchoscope to determine feasibility and histopathological analysis in animal models. Rabbit lung cancers were created by transbronchial injection of VX2 rabbit cancer cells. Once the tumors were developed, they were ablated transpleurally, under EBUS guidance using the prototype RFA device. The animals were then sacrificed for specimen resection. Pig inflammatory lung pseudo-tumors and lymphadenopathy were created by transbronchial injection of a talc paste and ablated transbronchially under EBUS guidance. Pigs were evaluated at 5 days, 2 weeks, and 4 weeks following ablation by bronchoscopy and cone beam computed tomography before necropsy. Nicotinamide adenine dinucleotide hydrogen diaphorase staining was employed to measure the ablation area. Twenty-four VX2 rabbit tumors were ablated. The total ablated area ranged from 0.6 to 3.0 cm² (mean: 1.8 cm²), corresponding to a total energy range of 1 to 6 kJ. Six pig lung pseudo-tumors and 5 mediastinal lymph nodes were ablated. Adjacent airway ulceration was observed in 3 ablations of lymph nodes. These airway complications resolved within 4 weeks of RFA without any treatment. There was no hemoptysis, air embolism, respiratory distress, or other serious complication noted. In these 2 animal models, we provide evidence that EBUS-guided bipolar RFA is feasible and histopathology shows that can ablate lung tumors and mediastinal lymph nodes under real-time ultrasound guidance.

Cone beam CT for perioperative imaging in hearing preservation Cochlear implantation - a human cadaveric study

Background

Knowledge of the cochlear implant array’s precise position is important because of the correlation between electrode position and speech understanding. Several groups have provided recent image processing evidence to determine scalar translocation, angular insertion depth, and cochlear duct length (CDL); all of which are being used for patient-specific programming. Cone beam computed tomography (CBCT) is increasingly used in otology due to its superior resolution and low radiation dose. Our objectives are as followed:

Validate CBCT by measuring cochlear metrics, including basal turn diameter (A-value) and lateral wall cochlear duct length at different angular intervals and comparing it against microcomputed CT (uCT).

Explore the relationship between measured lateral wall cochlear duct length at different angular intervals and insertion depth among 3 different length electrodes using CBCT.

Methods

The study was performed using fixed human cadaveric temporal bones in a tertiary academic centre. Ten temporal bones were subjected to the standard facial recess approach for cochlear implantation and imaged by CBCT followed by uCT. Measurements were performed on a three-dimensional reconstructed model of the cochlea. Sequential insertion of 3 electrodes (Med-El Flex24, 28 and Soft) was then performed in 5 bones and reimaged by CBCT. Statistical analysis was performed using Pearson’s correlation.

Results

There was good agreement between CBCT and uCT for cochlear metrics, validating the precision of CBCT against the current gold standard uCT in imaging. The A-value recorded by both modalities showed a high degree of linear correlation and did not differ by more than 0.23 mm in absolute values. For the measurement of lateral wall CDL at various points along the cochlea, there was a good correlation between both modalities at 360 deg and 720 deg (r = 0.85, p < 0.01 and r = 0.79, p < 0.01). The Flex24 electrode displayed consistent insertion depth across different bones.

Conclusions

CBCT reliably performs cochlear metrics and measures electrode insertion depth. The low radiation dose, fast acquisition time, diminished metallic artifacts and portability of CBCT make it a valid option for imaging in cochlear implant surgery.

Donor prone positioning protects lungs from injury during warm ischemia

A large proportion of controlled donation after circulatory death (cDCD) donor lungs are declined because cardiac arrest does not occur within a suitable time after the withdrawal of life-sustaining therapy. Improved strategies to preserve lungs after asystole may allow the recovery team to arrive after death actually occurs and enable the recovery of lungs from more cDCD donors. The aim of this study was to determine the effect of donor positioning on the quality of lung preservation after cardiac arrest in a cDCD model. Cardiac arrest was induced by withdrawal of ventilation under anesthesia in pigs. After asystole, animals were divided into 2 groups based on body positioning (supine or prone). All animals were subjected to 3 hours of warm ischemia. After the observation period, donor lungs were explanted and preserved at 4°C for 6 hours, followed by 6 hours of physiologic and biological lung assessment under normothermic ex vivo lung perfusion. Donor lungs from the prone group displayed significantly greater quality as reflected by better function during ex vivo lung perfusion, less edema formation, less cell death, and decreased inflammation compared with the supine group. A simple maneuver of donor prone positioning after cardiac arrest significantly improves lung graft preservation and function.

An Orthotopic Endometrial Cancer Model with Retroperitoneal Lymphadenopathy Made From In Vivo Propagated and Cultured VX2 Cells

Endometrial cancer is the most common gynecologic malignancy in North America and the incidence is rising worldwide. Treatment consists of surgery with or without adjuvant therapy depending on lymph node involvement as determined by lymphadenectomy. Lymphadenectomy is a morbid procedure, which has not been shown to have a therapeutic benefit in many patients, and thus a new method to diagnose lymph node metastases is required. To test novel imaging agents, a reliable model of endometrial cancer with retroperitoneal lymph node metastases is needed. The VX2 endometrial cancer model has been described frequently in the literature; however, significant variation exists with respect to the method of model establishment. Furthermore, no studies have reported on the use of cultured VX2 cells to create this model as only cells propagated in vivo have been previously used. Herein, we present a standardized surgical method and post-operative monitoring method for the establishment of the VX2 endometrial cancer model and report on the first use of cultured VX2 cells to create this model.

Use of Porphysomes to detect primary tumour, lymph node metastases, intra-abdominal metastases and as a tool for image-guided lymphadenectomy: proof of concept in endometrial cancer

Objective: To investigate Porphysome fluorescence image-guided resection (PYRO-FGR) for detection of uterine tumour, metastatic lymph nodes and abdominal metastases in a model of endometrial cancer.

Methods: White New Zealand rabbits were inoculated with VX2 cells via intra-myometrial injection. At 30 days, Porphysomes were administered intravenously. At 24 h the abdomen was imaged and fluorescent tissue identified (PYRO-FGR). After complete resection of fluorescent tissue, fluorescence-negative lymph nodes and peritoneal biopsies were removed. Histopathology including ultra-staging and analysis by a pathologist was used to detect tumour. Fluorescence signal to background ratio (SBR) was calculated and VX2 (+) tissue compared to VX2 (-) tissue. Biodistribution was calculated and Porphysome accumulation in fluorescent VX2 (+) tissue compared to fluorescent VX2 (-) and non-fluorescent VX2 (-) tissue.

Results: Of 17 VX2 models, 10 received 4 mg/kg of Porphysomes and 7 received 1 mg/kg. Seventeen tumours (UT), 81 lymph nodes (LN) and 54 abdominal metastases (AM) were fluorescence-positive and resected. Of these, 17 UT, 60 LN and 45 AM were VX2 (+), while 16 LN and 5 AM were VX2 (-). Nine specimens were excluded from analysis. Thirty-one LN and 53 peritoneal biopsies were fluorescence-negative and resected. Of these, all LN and 51/53 biopsies were VX2 (-) with only 2 false-negative biopsies. Sensitivity and specificity of PYRO-FGR for VX2 (+) tissue was 98.4% / 80.0% overall, 100% / 100% for UT, 100% / 66.0 % for LN and 95.7% / 91.4% for AM. Increased SBR and biodistribution was observed in VX2 (+) tissue vs. VX2 (-) tissue.

Conclusions: Porphysomes are a highly sensitive imaging agent for intra-operative detection and resection of uterine tumour, metastatic lymph nodes and abdominal metastases.

TM3-4 The effect of acetazolamide on intracranial pressure: primary study with prolonged continuous intracranial pressure monitoring

Objectives

Acetazolamide has frequently been used as a first-line treatment for idiopathic Intracranial Hypertension (IIH) and other disorders which lead to a non-acute rise in intracranial pressure (ICP). The effect of acetazolamide has been observed through lumbar puncture, however the effect of acetazolamide on ICP has not been studied in continuous ICP measurement.

Design

A retrospective study of a prospectively built ICP database

Subjects

All patients with continuous ICP monitoring demonstrating 24 hours on and 24 hours off acetazolamide were included in the study.

Methods

Patients median ICP and median pulse amplitude over 24 hour monitoring period on and off Diamox was assessed.

Results

12 patients (9F, 3M) underwent ICP monitoring with data collected during the same admission. 8 patients had IIH, 1 Chiari Malformation, 3 new diagnostic ICP procedures. 10 patients saw a reduction in ICP while on acetazolamide. Overall, patients experienced a Median reduction of 1.14 mmHg (Mean 1.16 mmHg, Range 4.24 to −4.445 mmHg). Patients (n9) who were on ≥1 g of acetazolamide per day experienced a median reduction in ICP of 1.595 mmHg (Mean 1.91 mmHg, Range 4.24–0.5 mmHg).

Conclusions

Our data suggests acetazolamide can reduce ICP quickly following commencement, however this reduction was relatively small. The effect seems greater with a higher dose. Larger numbers of patients are required to gain a greater understanding into the significance of acetazolamide on ICP, particularly the affect at larger doses.

Screening for retinopathy of prematurity by telemedicine in a tertiary level neonatal intensive care unit in France: Review of a six-year period

PURPOSE

To analyze the prevalence and risk factors for retinopathy of prematurity (ROP) and severe (treatment-requiring) ROP.

METHODS

A retrospective study was conducted in a level III neonatal unit in Bordeaux, France, from 2009 to 2015. Four hundred and nineteen preterm infants who were screened for ROP exclusively by RetCam were included.

RESULTS

ROP of any degree was diagnosed in 27.68% of infants. Stages 1, 2, 3 and 4 ROP was found in 44%, 46%, 9% and 1% of subjects, respectively. No stage 5 ROP was observed. 28/419 infants (6.6%) were treated exclusively with laser photocoagulation. No intravitreal anti-VEGF injections or surgical treatments were performed. No infants born at>31 weeks or with BW>1110g required ROP treatment. On multivariate analysis, risk factors for ROP development were low birth weight, low gestational age at birth, high duration of invasive mechanical ventilation, shock or use of vasopressors. On multivariate analysis, risk factors for severe, treatment-requiring ROP were male gender, gestational age≤27 weeks and Apgar score at 5minutes≤7.

CONCLUSION

In our 6-year series, ROP was successfully identified on screening exclusively by telemedicine, and no surgical treatment was required. This study identifies known ROP risk factors, but the Apgar score at 5minutes as a risk factor for severe ROP requires further studies in order to be confirmed.

Novel Thoracoscopic Navigation System With Augmented Real-Time Image Guidance for Chest Wall Tumors

BACKGROUND

We developed a thoracoscopic surgical navigation system with real-time augmented image guidance to assess the potential benefits for minimally invasive resection of chest wall tumors. The accuracy of localization of tumor and resection margin and the effect on task workload and confidence were evaluated in a chest wall tumor phantom.

METHODS

After scanning a realistic tumor phantom by cone-beam computed tomography and registering the data into the system, three-dimensional contoured tumor and resection margin was displayed. Fifteen surgeons were asked to localize the tumor margin and surgical margins with the thoracoscope alone. The same procedure was performed with the surgical navigation system activated, and results were compared between each attempt. A questionnaire and National Aeronautics and Space Administration Task Load Index were completed after.

RESULTS

The surgical navigation system significantly reduced localization error for the medial (p = 0.002) and superior tumor margin (p < 0.001), which was difficult to visualize by thoracoscopy alone. All surgical resection margins were improved circumferentially, including margins that were readily visible by thoracoscopy. National Aeronautics and Space Administration Task Load Index response scores showed a statistically significant reduction in workload in all subscales. There was a more than 50% mean reduction in workload for performance (10.1 vs 4.4, p = 0.001) and frustration (13.0 vs 5.4, p = 0.001).

CONCLUSIONS

This study showed that the thoracoscopic surgical navigation system providing augmented image guidance decreased tumor localization error for regions difficult to visualize thoracoscopically and also reduced surgical margin error circumferentially, regardless of thoracoscopic visibility. This system also reduced workload and increased surgeon's confidence in localizing challenging chest wall tumors.

Cone-Beam Computed Tomography-Guided Navigation in Complex Osteotomies Improves Accuracy at All Competence Levels: A Study Assessing Accuracy and Reproducibility of Joint-Sparing Bone Cuts

BACKGROUND

The objective of this study was to assess the accuracy and reproducibility of a novel cone-beam computed tomography (CBCT)-guided navigation system designed for osteotomies with joint-sparing bone cuts.

METHODS

Eighteen surgeons participated in this study. First, 3 expert tumor surgeons resected bone tumors in 3 Sawbones tumor models identical to actual patient scenarios. They first performed these osteotomies without navigation and then performed them using a navigation system and 3-dimensional (3D) planning tools based on CBCT imaging. The 2 sets of measurements were compared using image-based measurements from post-resection CBCT. Next, 15 residents, fellows, and orthopaedic staff surgeons were instructed on the use of the system, and their navigated resections were compared with navigated resections performed by the 3 expert tumor surgeons.

RESULTS

One hundred and twenty-six navigated cuts done by the orthopaedic oncologists were compared with 126 non-navigated cuts by the same surgeons. The cuts violated the tumor in 22% (6) of the 27 non-navigated resections compared with none of the 27 navigated resections. The navigated cuts were significantly more accurate in terms of entry point, pitch, and roll (p < 0.001). The variation among the 3 surgeons when they used navigation was <0.6 mm for the entry cut and, on average, 1.5° for pitch and roll. All 18 surgeons then completed a total of 144 navigated cuts. The level of experience did not result in a significant difference among groups with regard to cut accuracy. Two cuts went into the tumor. The mean distance from the planned bone cuts to the actual entry points into bone was 1.5 mm (standard deviation [SD] = 1.4 mm) for all users. The mean difference in pitch and roll between the planned and actual cuts was 3.5° (SD = 2.8°) and 3.7° (SD = 3.2°) for all users.

CONCLUSIONS

Even in expert hands, navigated cuts were significantly more accurate than non-navigated cuts. When the osteotomies were aided by navigation, their accuracy did not differ according to the level of professional experience. CBCT-based metrics enable intraoperative assessments of cut accuracy and reconstruction planning.

CLINICAL RELEVANCE

CBCT-guided navigated osteotomies can improve accuracy regardless of surgeon experience and decrease the variability among different surgeons.

Volumetric Analysis of Endoscopic and Maxillary Swing Surgical Approaches for Nasopharyngectomy

Objectives/Hypothesis  The endoscopic endonasal approach (EEA) for nasopharyngectomy is an alternative to the maxillary swing approach (MSA) for selected recurrent nasopharyngeal carcinomas (NPC). We compare the access between these approaches. Methods  Three cadaver specimens were used to compare access volumes of the EEA and MSA. Exposure volumes were calculated using image guidance registration to cone beam computed tomography and tracking of accessible tissue with volumetric quantification. The area of exposure to the carotid artery was measured. Results  The MSA provided higher volumes for access volume compared with the EEA (66.6 vs 39.1 cm ³ , p  = 0.009). The working area was larger in the MSA (80.2 vs 56.9 cm ² , p  = 0.06). The exposure to the carotid artery was higher in the MSA (1.88 vs 1.62 cm ² , p  = 0.04). The MSA provided larger volume of exposure for tumors of the parapharyngeal space with exposure below the palate. Conclusions  This study suggests that the MSA for nasopharyngectomy provides a larger volume of exposure. However, much of the increased exposure relates to exposure of the parapharyngeal space below the palate. The EEA provides adequate access to superior anatomical structures.

Dietary practices in propionic acidemia: A European survey

Background

The definitive dietary management of propionic acidaemia (PA) is unknown although natural protein restriction with adequate energy provision is of key importance.

Aim

To describe European dietary practices in the management of patients with PA prior to the publication of the European PA guidelines.

Methods

This was a cross-sectional survey consisting of 27 questions about the dietary practices in PA patients circulated to European IMD dietitians and health professionals in 2014.

Results

Information on protein restricted diets of 186 PA patients from 47 centres, representing 14 European countries was collected. Total protein intake [PA precursor-free L-amino acid supplements (PFAA) and natural protein] met WHO/FAO/UNU (2007) safe protein requirements for age in 36 centres (77%). PFAA were used to supplement natural protein intake in 81% (n = 38) of centres, providing a median of 44% (14–83%) of total protein requirement. Seventy-four per cent of patients were prescribed natural protein intakes below WHO/FAO/UNU (2007) safe levels in one or more of the following age groups: 0–6 m, 7–12 m, 1–10 y, 11–16 y and > 16 y. Sixty-three per cent (n = 117) of patients were tube fed (74% gastrostomy), but only 22% received nocturnal feeds.

Conclusions

There was high use of PFAA with intakes of natural protein commonly below WHO/FAO/UNU (2007) safe levels. Optimal dietary management can only be determined by longitudinal, multi-centre, prospective case controlled studies. The metabolic instability of PA and small patient cohorts in each centre ensure that this is a challenging undertaking.

Real-time continuous image-guided surgery: Preclinical investigation in glossectomy

OBJECTIVES/HYPOTHESIS

To develop, validate, and study the efficacy of an intraoperative real-time continuous image-guided surgery (RTC-IGS) system for glossectomy.

STUDY DESIGN

Prospective study.

METHODS

We created a RTC-IGS system and surgical simulator for glossectomy, enabling definition of a surgical target preoperatively, real-time cautery tracking, and display of a surgical plan intraoperatively. System performance was evaluated by a group of otolaryngology residents, fellows, medical students, and staff under a reproducible setting by using realistic tongue phantoms. Evaluators were grouped into a senior and a junior group based on surgical experience, and guided and unguided tumor resections were performed. National Aeronautics and Space Administration Task Load Index (NASA-TLX) scores and a Likert scale were used to measure workloads and impressions of the system, respectively. Efficacy was studied by comparing surgical accuracy, time, collateral damage, and workload between RTC-IGS and non-navigated resections.

RESULTS

The senior group performed more accurately (80.9% ± 3.7% vs. 75.2% ± 5.5%, P = .28), required less time (5.0 ± 1.3 minutes vs. 7.3 ± 1.2 minutes, P = .17), and experienced lower workload (43 ± 2.0 vs. 64.4 ± 1.3 NASA-TLX score, P = .08), suggesting a trend of construct validity. Impressions were favorable, with participants reporting the system is a valuable practice tool (4.0/5 ± 0.3) and increases confidence (3.9/5 ± 0.4). Use of RTC-IGS improved both groups' accuracy, with the junior group improving from 64.4% ± 5.4% to 75.2% ± 5.5% (P = .01) and the senior group improving from 76.1% ± 4.5% to 80.9% ± 3.7% (P = .16).

CONCLUSIONS

We created an RTC-IGS system and surgical simulator and demonstrated a trend of construct validity. Our navigated simulator allows junior trainees to practice glossectomies outside the operating room. In all evaluators, navigation assistance resulted in increased surgical accuracy.

LEVEL OF EVIDENCE

NA Laryngoscope, 127:E347-E353, 2017.

Accuracy and reproducibility of virtual cutting guides and 3D-navigation for osteotomies of the mandible and maxilla

Background

We set out to determine the accuracy of 3D-navigated mandibular and maxillary osteotomies with the ultimate aim to integrate virtual cutting guides and 3D-navigation into ablative and reconstructive head and neck surgery.

Methods

Four surgeons (two attending, two clinical fellows) completed 224 unnavigated and 224 3D-navigated osteotomies on anatomical models according to preoperative 3D plans. The osteotomized bones were scanned and analyzed.

Results

Median distance from the virtual plan was 2.1 mm unnavigated (IQR 2.6 mm, ≥3 mm in 33%) and 1.2 mm 3D-navigated (IQR 1.1 mm, ≥3 mm in 6%) (P<0.0001); median pitch was 4.5° unnavigated (IQR 7.1°) and 3.5° 3D-navigated (IQR 4.0°) (P<0.0001); median roll was 7.4° unnavigated (IQR 8.5°) and 2.6° 3D-navigated (IQR 3.8°) (P<0.0001).

Conclusion

3D-rendering enables osteotomy navigation. 3 mm is an appropriate planning distance. The next steps are translating virtual cutting guides to free bone flap reconstruction and clinical use.

Dietary practices in isovaleric acidemia: A European survey

Background

In Europe, dietary management of isovaleric acidemia (IVA) may vary widely. There is limited collective information about dietetic management.

Aim

To describe European practice regarding the dietary management of IVA, prior to the availability of the E-IMD IVA guidelines (E-IMD 2014).

Methods

A cross-sectional questionnaire was sent to all European dietitians who were either members of the Society for the Study of Inborn Errors of Metabolism Dietitians Group (SSIEM-DG) or whom had responded to previous questionnaires on dietetic practice (n = 53). The questionnaire comprised 27 questions about the dietary management of IVA.

Results

Information on 140 patients with IVA from 39 centres was reported. 133 patients (38 centres) were given a protein restricted diet. Leucine-free amino acid supplements (LFAA) were routinely used to supplement protein intake in 58% of centres. The median total protein intake prescribed achieved the WHO/FAO/UNU [2007] safe levels of protein intake in all age groups. Centres that prescribed LFAA had lower natural protein intakes in most age groups except 1 to 10 y. In contrast, when centres were not using LFAA, the median natural protein intake met WHO/FAO/UNU [2007] safe levels of protein intake in all age groups. Enteral tube feeding was rarely prescribed.

Conclusions

This survey demonstrates wide differences in dietary practice in the management of IVA across European centres. It provides unique dietary data collectively representing European practices in IVA which can be used as a foundation to compare dietary management changes as a consequence of the first E-IMD IVA guidelines availability.

Stable J-aggregation enabled dual photoacoustic and fluorescence nanoparticles for intraoperative cancer imaging

J-aggregates display nanoscale optical properties which enable their use in fluorescence and photoacoustic imaging applications. However, control over their optical properties in an in vivo setting is hampered by the conformational lability of the J-aggregate structure in complex biological environments. J-aggregating nanoparticles (JNP) formed by self-assembly of bacteriopheophorbide-lipid (Bchl-lipid) in lipid nanovesicles represents a novel strategy to stabilize J-aggregates for in vivo bioimaging applications. We find that 15 mol% Bchl-lipid embedded within a saturated phospholipid bilayer vesicle was optimal in terms of maximizing Bchl-lipid dye loading, while maintaining a spherical nanoparticle morphology and retaining spectral properties characteristic of J-aggregates. The addition of cholesterol maintains the stability of the J-aggregate absorption band for up to 6 hours in the presence of 90% FBS. In a proof-of-concept experiment, we successfully applied JNPs as a fluorescence contrast agent for real-time intraoperative detection of metastatic lymph nodes in a rabbit head-and-neck cancer model. Lymph node metastasis delineation was further verified by visualizing the JNP within the excised lymph node using photoacoustic imaging. Using JNPs, we demonstrate the possibility of using J-aggregates as fluorescence and photoacoustic contrast agents and may potentially spur the development of other nanomaterials that can stably induce J-aggregation for in vivo cancer bioimaging applications.

Postprandial capillary-venous glucose gradient in Type 1 diabetes: magnitude and clinical associations in a real world setting

AIMS

To determine the magnitude of the peripheral glucose gradient in patients with Type 1 diabetes in a real world setting and to explore its relationship with insulin dose and macronutrient intake.

METHODS

All patients used mealtime analogue insulin. The glucose gradient was assessed using antecubital fossa venous and finger-stick capillary samples, collected concurrently at room temperature. Baseline sampling occurred before the administration of an insulin dose and breakfast of the patient's choosing. Breakfast was consumed an average of 15 min after baseline. The macronutrient content of breakfast was documented. Sampling was repeated 1 and 2 h after baseline.

RESULTS

The mean (95% CI) plasma capillary-venous glucose gradient values for 43 patients were: pre-breakfast, 0.21 (0.08-0.34) mmol/l; 1 h after baseline, 0.87 (0.66-1.07) mmol/l; and 2 h after baseline, 0.52 (0.33-0.71) mmol/l. Glucose gradient and dietary carbohydrate intake (g/kg body weight) were positively correlated at both 1 h (P < 0.01) and 2 h after baseline (P < 0.01). No relationship was observed between this gradient and mealtime insulin dose, or the glucose concentration at either time point.

CONCLUSIONS

In patients with Type 1 diabetes, a clinically significant glucose gradient is present after the ingestion of a carbohydrate-rich meal. As postprandial capillary and venous plasma glucose concentrations are not equivalent, defining the site of sample collection is important.

Three-dimensional virtual navigation versus conventional image guidance: A randomized controlled trial

OBJECTIVES/HYPOTHESIS

Providing image guidance in a 3-dimensional (3D) format, visually more in keeping with the operative field, could potentially reduce workload and lead to faster and more accurate navigation. We wished to assess a 3D virtual-view surgical navigation prototype in comparison to a traditional 2D system.

METHODS

Thirty-seven otolaryngology surgeons and trainees completed a randomized crossover navigation exercise on a cadaver model. Each subject identified three sinonasal landmarks with 3D virtual (3DV) image guidance and three landmarks with conventional cross-sectional computed tomography (CT) image guidance. Subjects were randomized with regard to which side and display type was tested initially. Accuracy, task completion time, and task workload were recorded.

RESULTS

Display type did not influence accuracy (P > 0.2) or efficiency (P > 0.3) for any of the six landmarks investigated. Pooled landmark data revealed a trend of improved accuracy in the 3DV group by 0.44 millimeters (95% confidence interval [0.00-0.88]). High-volume surgeons were significantly faster (P < 0.01) and had reduced workload scores in all domains (P < 0.01), but they were no more accurate (P > 0.28).

CONCLUSION

Real-time 3D image guidance did not influence accuracy, efficiency, or task workload when compared to conventional triplanar image guidance. The subtle pooled accuracy advantage for the 3DV view is unlikely to be of clinical significance. Experience level was strongly correlated to task completion time and workload but did not influence accuracy.

LEVEL OF EVIDENCE

N/A. Laryngoscope, 126:1510-1515, 2016.