E12 technique: Conventional epoxy resin sheet plastination.

Epoxy plastination techniques were developed to obtain thin transparent body slices with high anatomical detail. This is facilitated because the plastinated tissue is transparent and the topography of the anatomical structures well preserved. For this reason, thin epoxy slices are currently used for research purposes in both macroscopic and microscopic studies. The protocol for the conventional epoxy technique (E12) follows the main steps of plastination-specimen preparation, dehydration, impregnation and curing/casting. Preparation begins with selection of the specimen, followed by freezing and slicing. Either fresh or fixed (embalmed) tissue is suitable for epoxy plastination, while slice thickness is kept between 1.5 and 3 mm. Impregnation mixture is made of epoxy E12 resin plus E1 hardener (100 ppw; 28 ppw). This mixture is reactive and temperature sensitive, and for this reason, total impregnation time under vacuum at room laboratory temperature should not last for more than 20-24 hr. Casting of impregnated slices is done in either flat chambers or by the so-called sandwich method in either fresh mixture or the one used for impregnation. Curing is completed at 40°C to allow a complete polymerization of the epoxy-mixture. After curing, slices can be photographed, scanned or used for anatomical study under screen negatoscope, magnification glass or fluorescent microscope. Based on epoxy sheet plastination, many anatomical papers have recent observations of and/or clarification of anatomical concepts in different areas of medical expertice.

Plastination-A scientific method for teaching and research.

Over the last four decades, plastination has been one of the best processes of preservation for organic tissue. In this process, water and lipids in biological tissues are replaced by polymers (silicone, epoxy, polyester) which are hardened, resulting in dry, odourless and durable specimens. Nowadays, after more than 40 years of its development, plastination is applied in more than 400 departments of anatomy, pathology, forensic sciences and biology all over the world. The most known polymers used in plastination are silicone (S10), epoxy (E12) and polyester (P40). The key element in plastination is the impregnation stage, and therefore depending on the polymer that is used, the optical quality of specimens differs. The S10 silicone technique is the most common technique used in plastination. Specimens can be used, especially in teaching, as they are easy to handle and display a realistic topography. Plastinated silicone specimens are used for displaying whole bodies, or body parts for exhibition. Transparent tissue sections, with a thickness between 1 and 4 mm, are usually produced by using epoxy (E12) or polyester (P40) polymer. These sections can be used to study both macroscopic and microscopic structures. Compared with the usual methods of dissection or corrosion, plastinated slices have the advantage of not destroying or altering the spatial relationships of structures. Plastination can be used as a teaching and research tool. Besides the teaching and scientific sector, plastination becomes a common resource for exhibitions, as worldwide more and more exhibitions use plastinated specimens.

Reliability of high-resolution ultrasound and magnetic resonance arthrography of the shoulder in patients with sports-related shoulder injuries.

INTRODUCTION: The shoulder, a very complex joint, offers a wide range of pathologies. Intraarticular abnormalities and rotator cuff injuries are mainly assessed and diagnosed by magnetic resonance arthrography (MRA). In contrast to this well-established gold standard, high-resolution ultrasound (US) offers an additional easy and excellent modality to assess the shoulder joint. Therefore, the purpose of this study was to evaluate in which anatomic structures and pathologies comparable results of US and MRA could be achieved. MATERIALS AND METHODS: In this IRB-approved prospective study 67 patients with clinically suspected labral lesions, rotator cuff rupture, or injury of the long head of the biceps (LHB) tendon were enrolled. Each participant was examined with high resolution US, and directly followed by MRA at 3 Tesla with a standard sequence protocol. To evaluate the agreement of the diagnostic performance between US and MRA a weighted kappa statistic was used. RESULTS: Both of the investigated modalities yielded a moderate to almost perfect agreement in assessing a wide range of shoulder joint pathologies. For the rotator cuff, consistency was found in 71.64% for the supraspinatus tendon, in 95.52% for the infraspinatus tendon, in 83.58% for the subscapularis tendon, and in 98.51% for the teres minor tendon. The diagnostic accuracy between both modalities was 80.60% for the LHB tendon, 77.61% for the posterior labroligamentous complex, 83.58% for the acromioclavicular joint, and 91.04% for the assessment of osseous irregularities and impaction fractures. CONCLUSIONS: High resolution US is a reliable imaging modality for the rotator cuff, the LHB tendon, and the acromioclavicular joint, so for these structures we recommend a preference for US over MRA based on its diagnostic accuracy, comfortability, cost effectiveness, and availability. If the diagnosis remains elusive, for all other intraarticular structures we recommend MRA for further diagnostic assessment.

Ultra-thin sectioning and grinding of epoxy plastinated tissue.

With classical sheet plastination techniques such as E12, the level and thickness of the freeze-cut sections decide on what is visible in the final sheet plastinated sections. However, there are other plastination techniques available where we can look for specific anatomical structures through the thickness of the tissue. These techniques include sectioning and grinding of plastinated tissue blocks or thick slices. The ultra-thin E12 technique, unlike the classic E12 technique, starts with the plastination of a large tissue block. High temperatures (30-60°C) facilitate the vacuum-forced impregnation by decreasing the viscosity of the E12 and increasing the vapour pressure of the intermediary solvent. By sectioning the cured tissue block with a diamond band saw plastinated sections with a thickness of <300 µm can be obtained. The thickness of plastinated sections can be further reduced by grinding. Resulting sections of <100 µm are suitable for histological staining and microscopic studies. Anatomical structures of interest in thick plastinate slices can be followed by variable manual grinding in a method referred to as Tissue Tracing Technique (TTT). In addition, the tissue thickness can be adapted to the transparency or darkness of tissue types in different regions of the same plastinated section. The aim of this study was to evaluate the advantages of techniques based on sectioning and grinding of plastinated tissue (E12 ultra-thin and TTT) compared to conventional sheet-forming techniques (E12).

Peri-arterial Autonomic Innervation of the Human Ear.

Auricular vasomotor responses are considered to be signs of clinical conditions including migraine. The mechanisms of auricular vasomotor control are still debatable. This study aimed at investigating perivascular co-transmitters of vasomotor control in the auricle. Another aim was to provide three-dimensional arterial maps of the auricle, as a proxy of periarterial autonomic innervation. Twelve paired human auricles were used to visualize the arteries following Spalteholz clearing and µ-CT-based reconstruction. Perivascular innervation staining was conducted using anti-tyrosine hydroxylase (TH), anti-neuropeptide Y (NPY), anti-vasoactive intestinal peptide (VIP) and anti-choline acetyl transferase (ChAT). The combined Spalteholz technique and µ-CT revealed a highly consistent arrangement of the auricular vasculature. The superficial temporal (STA) and posterior auricular artery (PAA) supply the helical rim arcade and arcade, with the STA mainly forming the superior and the PAA forming the middle and inferior auricular artery. Co-existence of sympathetic NPY+ and TH+ terminals mediating vasoconstriction, and VIP+ and ACh+ indicating cholinergic vasodilatation, was found in the perivascular zone. The presence of both sympathetic vasoconstriction and cholinergic co-innervation for active vasodilatation was shown in the perivascular auricular zone. Assuming that the highly-consistent vasculature gives way to these terminals, this periarterial innervation may be found spread out across the helix.

Reevaluation of the arterial blood supply of the auricle.

The anatomical basis for auricular flaps used in multiple aesthetic and reconstructive procedures is currently based on a random distribution of the underlying arterial network. However, recent findings reveal a systematic pattern as opposed to the present concepts. Therefore, we designed this study to assess the arterial vascular pattern of the auricle in order to provide reliable data about the vascular map required for surgical interventions. Sixteen human auricles from eight body donors (five females/three males, 84.33 ± 9.0 years) were investigated using the unique 'Spalteholz' method. After arterial injection of silicone, a complete transparency of the tissue was achieved and the auricular arteries and branches were visible. Qualitative and quantitative evaluation of the arterial vascular pattern was performed. The superior and the inferior anterior auricular artery provided the vascular supply to the helical rim, forming an arcade, i.e. helical rim arcade. On the superior third of the helical rim another arcade was confirmed between the superior anterior auricular artery and the posterior auricular artery (PAA), i.e. the helical arcade. The perforators of the PAA were identified lying in a vertical line 1 cm posterior to the tragus, supplying the concha, inferior crus, triangular fossa, antihelix and the earlobe. The results of this study confirmed the constant presence of the helical rim arcade (Zilinsky-Cotofana), consistent perforating branches of the PAA, and the helical arcade (Erdman), and will help and guide physicians performing auricular surgeries toward fast and simple procedures with optimal patient satisfaction.

The relationship of neurovascular structures to the posterior medial aspect of the knee: an anatomic study using plastinated cross-sections.

The purpose of this study was to evaluate the topography of the saphenous nerve branches and of the popliteal neurovascular bundle of knee and to establish a low risk placement position of the posteromedial knee portal (PmKP). A slice anatomy study, by using plastinated transparent knee cross-sections was performed on 12 intact right male cadaver lower limbs. The measurements were performed at the level of the medial epicondyle (MEc), at the joint line level and at the level of the tibial attachment of the posterior cruciate ligament (PCL). The popliteal artery (PA) is predicted to be 8.66±2.17 mm dorsal and the sartorial branch of the saphenous nerve (SBSN) at 4.27±0.05 mm posterior to the joint capsule at the level of the MEc. At the joint level, the PA is 7.86±2.26 mm away from the PCL and the SBSN is predicted at 2.41±0.12 mm posterior to the joint capsule. At the level of the tibial attachment of the PCL, the PA to PCL the distance is 5.93±3.61 mm and the SBSN is situated at 4.36±0.43 mm posterior to the joint capsule. Based on our anatomic data, a PmKP placed at the level of the MEc appears to be safe, effective, and reproducible. At the level of MEc, the PA is situated widely lateral to the MEc and the distance between the saphenous nerve branches and the articular capsule is greater than on the other levels. This study suggests that by placing the PmKP at the level of MEc, the risk of neurovascular injuries could be reduced.

Vaginal dose point reporting in cervical cancer patients treated with combined 2D/3D external beam radiotherapy and 2D/3D brachytherapy.

BACKGROUND AND PURPOSE: Traditionally, vaginal dose points have been defined at the vaginal source level, thus not providing dose information for the entire vagina. Since reliable vaginal dose volume/surface histograms are unavailable, a strategy for comprehensive vaginal dose reporting for combined EBRT and BT was established and investigated. MATERIAL AND METHODS: An anatomical vaginal reference point was defined at the level of the Posterior-Inferior Border of Symphysis (PIBS), plus two points ±2 cm (mid/introitus vagina). For BT extra points were selected for the upper vagina at 12/3/6/9 o'clock, at the vaginal surface and 5 mm depth. A vaginal reference length (VRL) was defined from ring centre to PIBS. Fifty-nine patients treated for cervical cancer were included in this retrospective feasibility study. RESULTS: The method was applicable to all patients. Total EQD2 doses at PIBS and ±2 cm were 36.7 Gy (3.1-68.2), 49.6 Gy (32.1-89.6) and 4.3 Gy (1.0-46.6). At the vaginal surface at ring level doses were respectively 266.1 Gy (67.6-814.5)/225.9 Gy (61.5-610.5) at 3/9 o'clock, and 85.1 Gy (55.4-140.3)/72.0 Gy (49.1-108.9) at 12/6 o'clock. Mean VRL on MRI was 5.6 cm (2.0-9.4). CONCLUSIONS: With this novel system, a comprehensive reporting of vaginal doses is feasible. The present study has demonstrated large dose variations between patients observed in all parts of the vagina, resulting from different contributions from EBRT and BT.

Computer aided three-dimensional reconstruction and modeling of the pelvis, by using plastinated cross sections, as a powerful tool for morphological investigations.

PURPOSE: The aim of this study was to describe a method of developing a computerized model of the human female pelvis using plastinated slices. Computerized reconstruction of anatomical structures is becoming very useful for developing anatomical teaching, research modules and animations. Although databases consisting of serial sections derived from frozen cadaver material exist, plastination represents an alternative method for developing anatomical data useful for computerized reconstruction. METHODS: A slice anatomy study, using plastinated transparent pelvis cross sections, was performed to obtain a 3D reconstruction. One female human pelvis used for this study, first plastinated as a block, then sliced into thin slices and in the end subjected to 3D computerized reconstruction using WinSURF modeling system (SURFdriver Software). To facilitate the understanding of the complex pelvic floor anatomy on sectional images obtained through MR imaging, and to make the representation more vivid, a female pelvis computer-aided 3D model was created. RESULTS: Qualitative observations revealed that the morphological features of the model were consistent with those displayed by typical cadaveric specimens. The quality of the reconstructed images appeared distinct, especially the spatial positions and complicated relationships of contiguous structures of the female pelvis. All reconstructed structures can be displayed in groups or as a whole and interactively rotated in 3D space. CONCLUSIONS: The utilization of plastinates for generating tissue sections is useful for 3D computerized modeling. The 3D model of the female pelvis presented in this paper provides a stereoscopic view to study the adjacent relationship and arrangement of respective pelvis sections. A better understanding of the pelvic floor anatomy is relevant to gynaecologists, radiologists, surgeons, urologists, physical therapists and all professionals who take care of women with pelvic floor dysfunction.

Anatomical exploration of a dicephalous goat kid using sheet plastination (E12).

A dicephalous, 1-day-old, female goat kid was presented for anatomical study. Epoxy plastination slices (E12) were used successfully to explore this condition. They provided excellent anatomic and bone detail, demonstrating organ position, shared structures, and vascular anatomy. Sheet plastination (E12) was used as an optimal method to clarify how the two heads were united, especially the neuroanatomy. The plastinated transparent slices allowed detailed study of the anatomical structures, in a non-collapsed and non-dislocated state. Thus, we anatomically explored this rare condition without traditional dissection. The advantages of plastination extended to the preservation at room temperature of this case for further topographical investigation. To the authors' best knowledge, this is the first published report of plastination of a dicephalous goat.

The posteromedial neurovascular bundle of the ankle: an anatomic study using plastinated cross sections.

PURPOSE: The aim of this study was to evaluate the topography of the posteromedial neurovascular bundle of the ankle. The anatomic relation of the posteromedial neurovascular bundle at different levels of the ankle was studied as an aid in planning minimally invasive surgery. A thorough knowledge of the local anatomy is a prerequisite before attempting release of the tibial nerve or when using the posteromedial portal for ankle arthroscopy. METHODS: A slice anatomy study was performed on 12 intact right male cadaveric lower limbs. The distal third of each limb was cut and the foot positioned in the neutral position. The measurements were performed at the level of the tibiotalar joint, at the tip of the medial malleolus, and at the sustentaculum tali. RESULTS: The tibial nerve is predicted to be 11.8 +/- 2.4 mm and the posterior tibial artery 16.7 +/- 3.8 mm anterior from the calcaneal tendon at the level of the tibiotalar joint. At the tip of the malleolus medialis, the tibial nerve is 14.3 +/- 2.5 mm and the posterior tibial artery 22.1 +/- 4.1 mm anterior to the Achilles tendon. The medial plantar nerve is situated at the sustentaculum tali level 8.4 +/- 3.4 mm and the lateral plantar nerve 16.1 +/- 3.1 mm posterior to the sustentaculum. CONCLUSIONS: On the basis of our anatomic data, a posteromedial portal made at the level of the tip of the medial malleolus seems to be safe, effective, and reproducible. Therefore a portal at this level would be advantageous for an endoscopic tarsal tunnel release or when using the posteromedial portal for ankle arthroscopy. Anatomic characteristics should be kept in mind when ankle surgery is performed, thereby reducing the risk of injury to the medial neurovascular bundle and offering easy access inside the posterior compartment of the ankle. CLINICAL RELEVANCE: This cadaveric study suggests that, by placing the posteromedial ankle portal at the tip of the medial malleolus, the risk of neurovascular injuries could be reduced.

Three-dimensional reconstruction of the ankle by means of ultrathin slice plastination.

Computerized reconstruction of anatomical structures is becoming very useful for developing anatomical teaching modules and animations. Although databases exist consisting of serial sections derived from frozen cadaver material, plastination represents an alternate method for developing anatomical data useful for computerized reconstruction. Plastination is used as an excellent tool for studying different anatomical and clinical questions. The sheet plastination technique is unique because it offers the possibility to produce transparent slices series, which can easily be processed morphometrically. The purpose of this study was to describe a method for developing a computerized model of the human ankle using plastinated slices. This method could be applied to reconstruct any desired region of the human body.A human ankle was obtained, plastinated, sectioned, and subjected to 3D computerized reconstruction using WinSURF modeling system (SURFdriver Software). Qualitative observations revealed that the morphological features of the model were consistent with those displayed by typical cadaveric specimens. Morphometric analysis indicated that the model did not significantly differ from a sample of cadaveric specimens. These data support the use of plastinates for generating tissues sections useful for 3D computerized modeling.

Evaluation of the ankle syndesmosis: a plastination slices study.

Plastination is an excellent tool for studying different anatomical and clinical questions. This technique is unique because it offers the possibility to produce transparent slices series that can be easily processed morphometrically. It is very difficult to recognize the subtle widening of the tibiofibular syndesmosis in less severe injuries of this articulation. Proper anatomic knowledge of the syndesmosis might be helpful. The ankle syndesmosis was investigated on 20 cadaver feet by using the E12 plastination technique. Each foot was cut into 1.6-mm transverse slices and then plastinated. The following parameters (reflecting the position of the fibula in the distal tibiofibular syndesmosis) were measured: the length (LFI) and the depth of the fibular incisure (DFI); the width of the clear space (TCS) and the tibiofibular overlap (TFO); the position of the fibula regarding the anterior aspect of the tibia (A); and the width of the fibula (W). Due to the unique approach of this method, values for the position of the fibular incisure with respect to the frontal (F) and sagittal (S) plane were described for the entire syndesmosis. The prevalence of syndesmotic injury in association with sprains of the ankle is up to 11%. The data presented in the study are useful for the appreciation of the correct position of the fibula in the fibular incisure and can be correlated with standard anterior-posterior radiographies and CT examinations of the ankle joint.

Anatomy and the access grid: exploiting plastinated brain sections for use in distributed medical education.

Computerized animation is becoming an increasingly popular method to provide dynamic presentation of anatomical concepts. However, most animations use artistic renderings as the base illustrations that are subsequently altered to depict movement. In most cases, the artistic rendering is a schematic that lacks realism. Plastinated sections provide a useful alternative to artistic renderings to serve as a base image for animation. The purpose of this study is to describe a method for developing animations by using plastinated sections. This application is used in Project TOUCH as a supplemental learning tool for a problem-based learning case distributed over the National Computational Science Alliance's Access Grid. The case involves traumatic head injury that results in an epidural hematoma with transtentorial uncal herniation. In addition, a subdural hematoma is animated permitting the student to contrast the two processes for a better understanding of dural hematomas, in general. The method outlined uses P40 plastinated coronal brain sections that are digitized and to which contiguous anatomical structures are rendered. The base illustration is rendered, interpolated, and viewed while audio narration describes the event. This method demonstrates how realistic anatomical animations can be generated quickly and inexpensively for medical education purposes by using plastinated brain sections.

Aortic arch variation analyzed by using plastination.

Different ramification patterns can be observed during the development of the aortic arch. In this study a common trunk (CT), which subsequently branched into the brachiocephalic trunk (BT) and left common carotid artery (LCCA), arose from the aortic arch. The LCCA arose from the CT 10.27 mm above the aortic arch. After crossing the ventral aspect of the trachea and esophagus, the LCCA became situated on the left side of the esophagus. The caliber and length of the main branches of the aortic arch were determined and compared to reports in the literature. This variation was discovered in the context of producing transverse body slices using an E12 plastination process.