Purpose
Skin closure disorders in ankle surgery are a recurrent problem not only in traumatology but also in elective surgery. The aim of the study was to describe the anatomical basis of the ...fasciocutaneous vascularization of the lateral malleolus region to develop a posterior cover flap for the region.
Methods
We dissected ten fresh frozen specimens after arterial injection of an Indian ink preparation and individualized the perforating arteries. Their positions and diameters were collated. Then, the surgical technique was clinically applied for two different cases by transferring the fasciocutaneous flap posterior to the lateral malleolus to cover a loss of skin substance.
Results
There were in average 5 fibular perforators over the last 100 mm of the fibula. The average diameter of the first two perforating arteries was 0.6 ± 0.12 mm and 0.9 ± 0.25 mm, respectively, and the consistency of the latter makes it possible to produce a skin flap with anterior translation. This is an axial flap. Two patients were operated on using this technique. There was no necrosis of the posterior fibular flap and healing was achieved by the third post-operative week.
Conclusion
This study showed the presence of fibular perforating arteries with a high reproducibility of their dissection. This anatomical description served as the basis for the description of a new distal fibular perforating flap.
Introduction
The medial head of the triceps brachii flap is already described as a local muscular or as a free flap. It allows coverage of defects of the posterior cubital region. The aim of this ...study was to describe the vascular anatomy of the musculocutaneous medial triceps brachii pedicled flap.
Methods
Eleven fresh–frozen upper limbs (6 come from women and 5 from men) were proximally injected with Indian ink agar solution. The medial head of the triceps brachii muscle was dissected and the superior ulnar collateral artery (SUCA) was isolated with its collaterals. The collateral arteries were dissected to determine whether there were septocutaneous or musculocutaneous arteries for vascularization of the skin in front of the medial head. Lengths of those collaterals arteries were measured.
Results
The average number of collaterals arteries from the SUCA supplying the medial head of the triceps brachii is 4.5 (from 3 to 6 arteries). Among these collaterals’ arteries, there are one average 1.5 (0.6–4.5) septocutaneous arteries and 3 (1–4.8) musculocutaneous arteries.
Discussion and conclusion
A musculocutaneous flap with the medial head of the triceps brachii muscle can be described with the muscle. The SUCA gives perforator arteries musculocutaneous and septocutaneous for the vascularization of the triceps brachii medial head. The use of local pedicled flap with similar tissue maximizes healing with a minimal morbidity of the donor site. This study demonstrated the feasibility of the medial head triceps brachii musculocutaneous flap to cover defect of the posterior aspect of the elbow.
A common treatment option for pharmacoresistant epilepsy is to surgically remove epileptogenic zone. Stereoelectroencephalography (SEEG)_is a minimally invasive surgical procedure used to identify ...such zones. Precisely determining positions of all of implanted SEEG electrodes is crucial to design a resection plan. Metallic electrode contacts produce strong artefacts in CT scans which makes localisation process difficult and imprecise. We propose an automatic approach for accurate localisation of SEEG electrode contacts using a combination of a 2D and 3D U-Net architecture. The proposed hybrid network makes the best out of both models and makes more accurate predictions, resulting in a decrease of false-positive and false-negative segmentations. The network was trained on 36 data sets and evaluated on four different metrics. The Hybrid model outperformed both the 2D and the 3D U-Net model. To complete the electrode segmentation process, segmented contacts are linked into electrodes using Gaussian mixture models.
Purpose
Stereoelectroencephalography (SEEG) is a minimally invasive surgical procedure, used to locate epileptogenic zones. An accurate identification of the metallic contacts recording the SEEG ...signal is crucial to ensure effectiveness of the upcoming treatment. However, due to the presence of metal, post-operative CT scans contain strong streak artefacts that interfere with deep learning segmentation algorithms and require a lot of training data to distinguish from actual contacts. We propose a method to generate synthetic data and use them to train a neural network to precisely locate SEEG electrode contacts.
Methods
Random electrodes were generated following manufacturer’s specifications and dimensions and placed in acceptable regions inside metal-free CT images. Metal artefacts were simulated in the generated data set using radon transform, beam hardening, and filtered back projection. A UNet neural network was trained for the contacts segmentation task using various training set-ups combining real data, basic augmented data, and synthetic data. The results were compared.
Results
We reported a higher accuracy when including synthetic data during the network training, while training only on real and basic augmented data more often led to misclassified artefacts or missed contacts. The network segments post-operative CT slices in less than 2 s using 4 GeForce RTX2080 Ti GPUs and in under a minute using a standard PC with GeForce GTX1060.
Conclusion
Using synthetic data to train the network significantly improves contact detection and segmentation accuracy.
•Thermocoagulations induce the running-down of HFO and spikes in normo-heterotopic epileptogenic network.•Decreased epileptogenicity correlates well with significantly improved seizure ...control.•Combination of ictal and interictal biomarkers is crucial to define the epileptogenic zone.
Epilepsy associated with periventricular nodular heterotopia (PNH) is characterized by complex relationships between the heterotopic and the normotopic cortex during the interictal state and at seizure onset. High-frequency oscillations (HFO) have been proposed as a marker of epileptogenicity that might reflect disease activity. The effects of thermocoagulations on epileptogenicity in this context remain unknown. We aimed to investigate the interictal HFO- and spike profiles of different cortical structures before and after two consecutive SEEG-guided thermocoagulations, in correlation with seizure outcome, in a patient with PNH-related drug-resistant epilepsy.
The epileptogenic zone (EZ) was defined by SEEG analysis based on the Epileptogenicity Index. Interictal spikes, ripples (80–250 Hz) and fast ripples (FR, 250-330 Hz) were analyzed within the heterotopia, the temporal neocortex and the hippocampus.
The SEEG recordings revealed a distributed EZ involving the heterotopia and the posterior temporal neocortex. Both structures were targeted by thermocoagulations. Background spikes, ripples and FR-rates were significantly higher in PNH compared to the normotopic cortex. A drastic reduction of spikes (by over 80%) and absence of FR were demonstrated both in the PNH and in the neocortex during the second SEEG exploration 6 months after the first thermocoagulation, whereas no significant difference was observed in the posterior hippocampus. Ripples were significantly reduced by the first and suppressed by the second thermocoagulation within the three structures. Seizures relapsed after two months but decreased in frequency after the first thermocoagulation. Sustained seizure-freedom was achieved only after the second procedure.
Our data demonstrate the running down of interictal HFO and spikes within the epileptogenic network following thermocoagulations of heterotopic and normotopic sites involved at seizure onset. This dynamics was in good correlation with significantly improved seizure control.
Combination of ictal and different interictal markers of epileptogenicity, including HFO and spike analysis, is important to get the full picture of the epileptogenic zone and could help to evaluate the disease activity.
The superior part of the glenohumeral joint capsule has an intimate relationship with the tendons of the rotator cuff and the tendon of the long head of the biceps. One of the strategies currently ...proposed in the event of a massive cuff rupture is to reconstruct this superior capsule. The main objective of this anatomical study was to describe the superior joint capsule of the embryonic glenohumeral joint and its relationship to the tendons of the rotator cuff.
The hypothesis was that this structure was an anatomical entity, morphologically identifiable from the embryogenesis of the joint (more pronounced tissue boundaries in the fetus).
In total, 101 continuous fetal anatomical sections (4 fetuses of 336mm), in the frontal plane, made it possible to identify and measure: diameters of the humeral head and glenoid, dimensions of the joint capsule insertion zone at the level of the greater tubercle, as well as the different thicknesses of this insertion zone. The ratios above the head of the biceps and against the superior labrum were also measured.
At the level of its distal insertion on the greater tuberosity, the thickness of the superior joint capsule varies on average between 0.8mm laterally and 1.2mm next to the tendons of the supraspinatus and infraspinatus; the thickness is 0.9mm next to the middle part of the supraspinatus tendon (the “rotator cable” zone). For its insertion at the level of the glenoid labrum, the superior capsule measures 0.6mm thick on average. The capsule around the tendon of the long head of the biceps is 1.5mm thick on average.
Here, we confirm the existence of this superior joint capsule, which can potentially be reconstructed. It is inserted on the greater tubercle covering 30 to 60% of its surface with variations in thickness. The joint capsule is fused to the supraspinatus tendon at the rotator cuff insertion area, preventing independent reinsertion of the tendon.
IV; anatomical study.
Surgical treatment of Morton’s neuroma remains controversial. Several surgical techniques have been described including percutaneous transection of the deep metatarsal transverse ligament (DMTL).
To ...evaluate the efficacy and safety of percutaneous release of the DMTL under ultrasound guidance for the treatment of Morton’s syndrome.
Percutaneous release of the DMTL was performed with ultrasound guidance in 48 intermetatarsal spaces of 16 cadaveric specimens. Specimens were then dissected to assess the completion of the release and the presence of any injuries of the neurovascular and tendinous adjacent structures.
The DMTL was visualized with ultrasound in all cases. Complete release of the ligament was achieved in 87.5% (42/48) cases. One case of interdigital nerve injury was found.
Percutaneous release of DMTL with ultrasound guidance for the treatment of Morton’s disease has an acceptable rate of complications but care must be taken to ensure the complete release of the ligament.
Purpose
Accurate segmentation of brain resection cavities (RCs) aids in postoperative analysis and determining follow-up treatment. Convolutional neural networks (CNNs) are the state-of-the-art image ...segmentation technique, but require large annotated datasets for training. Annotation of 3D medical images is time-consuming, requires highly trained raters and may suffer from high inter-rater variability. Self-supervised learning strategies can leverage unlabeled data for training.
Methods
We developed an algorithm to simulate resections from preoperative magnetic resonance images (MRIs). We performed self-supervised training of a 3D CNN for RC segmentation using our simulation method. We curated EPISURG, a dataset comprising 430 postoperative and 268 preoperative MRIs from 430 refractory epilepsy patients who underwent resective neurosurgery. We fine-tuned our model on three small annotated datasets from different institutions and on the annotated images in EPISURG, comprising 20, 33, 19 and 133 subjects.
Results
The model trained on data with simulated resections obtained median (interquartile range) Dice score coefficients (DSCs) of 81.7 (16.4), 82.4 (36.4), 74.9 (24.2) and 80.5 (18.7) for each of the four datasets. After fine-tuning, DSCs were 89.2 (13.3), 84.1 (19.8), 80.2 (20.1) and 85.2 (10.8). For comparison, inter-rater agreement between human annotators from our previous study was 84.0 (9.9).
Conclusion
We present a self-supervised learning strategy for 3D CNNs using simulated RCs to accurately segment real RCs on postoperative MRI. Our method generalizes well to data from different institutions, pathologies and modalities. Source code, segmentation models and the EPISURG dataset are available at
https://github.com/fepegar/resseg-ijcars
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Lesions of the foramen magnum (FM) and craniocervical junction area are traditionally managed surgically through anterior, anterolateral, and posterolateral skull-base approaches. This anatomical ...study aimed to compare the usefulness of a modified extended endoscopic approach, the so-called far-medial endonasal approach (FMEA), versus the traditional posterolateral far-lateral approach (FLA).
Ten fixed silicon-injected heads specimens were used in the Skull Base ENT-Neurosurgery Laboratory of the University Hospital of Strasbourg, France. A total of 20 FLAs and 10 FMEAs were realized. A high-resolution computed tomography scan was performed for quantitative analysis of the different approaches. The analysis aimed to estimate the extent of surgical exposure and freedom of movement (maneuverability) through the operating channel using a polygonal surface model to obtain a morphometric estimation of the area of interest (surface and volume) on postdissection computed tomography scans using Slicer 3D software.
FMEA allows for a more direct route to the anterior FM, with wider brainstem exposure compared with the FLA and an excellent visualization of all anterior midline structures. The limitations of the FMEA include the deep and narrow surgical corridor and difficulty in reaching lesions located laterally over the jugular foramen and hypoglossal canal.
The FMEA and FLA are both effective surgical routes to reach FM and craniocervical junction lesions. Modern skull base surgeons should have a good command of both because they appear complementary. This anatomical study provides the tools for comprehensive preoperative evaluations and selection of the most appropriate surgical approach.
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