Preservation of macroparasite species via classic plastination: an evaluation.

Plastination is a preservation method for biological specimens, with important advantages over classic conservation techniques with formaldehyde or alcohol. Plastinated specimens are dry, odourless, and free of carcinogenic and toxic solutions. There are only few references about the plastination of parasites. Moreover, there is no information on the effect of plastination on the morphology and morphometry of these animals. The aim of this study was to define a plastination protocol to preserve various species of parasites, namely the nematodes Parascaris equorum (Goeze, 1782); Ascaris suum Goeze, 1782 and Dirofilaria immitis (Leidy, 1856); the acanthecephalan Macracanthorhynchus hirudinaceus (Pallas, 1781); the trematodes Fasciola hepatica Linnaeus, 1758 and Dicrocoelium dendriticum (Rudolphi, 1819) and the tapeworm Taenia sp. in the best morphological and morphometric conditions. Results showed that some individuals suffered collapse (P. equorum, A. suum, and D. dendriticum). However, other parasites presented good results with almost no change after plastination (D. immitis, M. hirudinaceus and F. hepatica). In conclusion, conventional plastination allowed anatomical preservation of all helminths tested, but modifications to the protocol are needed to prevent collapse.

Intestinal histopathological changes in a porcine model of pneumoperitoneum-induced intra-abdominal hypertension.

BACKGROUND: Low splanchnic perfusion is an immediate effect of pneumoperitoneum-induced intra-abdominal hypertension (IAH). Anatomical structure results in the intestinal mucosa being the area most sensitive to hypoperfusion. The relationship between intestinal injury and clinical parameters of tissue perfusion [abdominal perfusion pressure (APP), gastric intramucosal pH (pHi) and lactic acid (Lc)] has not been previously studied. This study aimed to monitorize intestinal pathogenesis through sequential ileal biopsies and to measure APP, pHi, and Lc levels at different pneumoperitoneum-induced intra-abdominal pressures (20, 30, and 40 mmHg) to evaluate the potential relationships between them. MATERIALS AND METHODS: Fifty pigs were divided into four groups; a control group (C) and three experimental groups with different pneumoperitoneum-induced levels [20 mmHg (G20), 30 mmHg (G30), and 40 mmHg (G40)], that were maintained for 3 and 5 h. APP, pHi, and Lc were measured and ileal biopsies taken laparoscopically every 30 min. The mucosal damage was graded using the standardized Park's Score and animals were classified as injured (I+) or uninjured (I-). RESULTS: Different histopathological lesions were observed in groups G20, G30, and G40 but no damage observed in group C. A 33.3% of animals in G20 and G30 were I+ after 3 h, while 93.3% were injured in G40. After 5 h, histopathological lesions were no longer seen in some animals in G20 and only 10% were I+. Conversely, in G30 I+ pigs increased to 80% while those in G40 remained at 93.3% I+. The I+ animals had significantly lower APP and pHi than those I-. Lc was the clinical parameter that showed the earliest differences, with significantly higher figures in I+ animals. CONCLUSIONS: The evolution of intestinal injuries from pneumoperitoneum-induced IAH depends on the degree of IAP. These damages may be associated with decreases in APP and pHi, and increases in Lc.

Evidences supporting the vascular etiology of post-double balloon enteroscopy pancreatitis: Study in porcine model.

Double balloon enteroscopy (DBE) is an endoscopic technique broadly used to diagnose and treat small bowel diseases. Among the associated complications of the oral DBE, post-procedure pancreatitis has taken the most attention due to its gravity and the thought that it might be associated to the technique itself and anatomical features of the pancreas. However, as the etiology has not been clarified yet, this paper aims to review the published literature and adds new results from a porcine animal model. Biochemical markers, histological sections and the vascular perfusion of the pancreas were monitored in the pig during DBE practice. A reduced perfusion of the pancreas and bowel, the presence of defined hypoxic areas and disseminated necrotic zones were found in the pancreatic tissue of pigs. All these evidences contribute to support a vascular distress as the most likely etiology of the post-DBE pancreatitis.

Modelo virtual tridimensional de la articulación cubital del perro a partir de cortes plastinados ultradelgados / Three-dimensional virtual model of the elbow joint of the dog by means of ultrathin plastinated slices

La articulación cubital del perro es de tipo compuesta, formada por el cóndilo del húmero, la cabeza del radio y la escotadura troclear de la ulna. Esta articulación es propensa a padecer enfermedades del desarrollo, lesiones traumáticas y degenerativas. La corrección de estos padecimientos suele ser quirúrgica, sin embargo, el planteamiento de la cirugía resulta difícil debido a la complejidad estructural de esta articulación. Los modelos anatómicos tridimensionales (3D) obtenidos de los cortes seriados mediante tomografía computarizada han probado ser eficaces en el planteamiento de los abordajes quirúrgicos, sin embargo tiene limitaciones técnicas en la identificación de los tejidos blandos. Los cortes ultradelgados (1 mm) obtenidos mediante plastinación permiten realizar descripciones anatómicas detalladas de regiones anatómicas complejas y también pueden ser usadas para realizar reconstrucciones 3D. El objetivo del presente trabajo, ha sido obtener una reconstrucción 3D de las estructuras anatómicas que conforman el codo del perro a partir de cortes plastinados ultradelgados.

The dog's elbow joint is a very complex structure formed between the humeral condyle, the radial head and the ulnar trochlear notch. This joint is prone to suffer growth disorders, traumatic injuries, and degenerative conditions. All these problems used to be solved by surgical means, nevertheless, the surgical plan, results in a complex decision making process related with the aforementioned joint characteristics, three dimensional (3D) anatomical models from computed tomography have proven to be useful in the surgical approach, nevertheless the image technique is at some point limited, mainly identifying soft tissues. Ultrathin plastinated slices (1 mm) allows to perform very detailed descriptions of complex structures and 3D reconstructions as well. The aim of this work, was to obtain a 3D reconstruction of ultrathin plastinated elbow joint in the dog.

[Diagnosis agreement between capsule endoscopy and double-balloon enteroscopy in obscure gastrointestinal bleeding at a referral center]. / Concordancia diagnóstica entre la cápsula endoscópica y enteroscopia de doblebalón en la hemorragia digestiva media en un centro de referencia.

BACKGROUND AND AIM: Capsule endoscopy and double balloon enteroscopy are well-recognized procedures in obscure gastrointestinal bleeding, with many factors that may influence their diagnosis yield. The aim of the present study was to characterize the degree of agreement between both techniques with focus on the type of lesion in a large cohort of patients at a referral center. MATERIAL AND METHOD: One thousand two hundred and nine capsules were administered in 1,078 patients and 381 enteroscopies were performed in 361 patients with obscure-gastrointestinal bleeding from 2004 to 2014. RESULTS: Both procedures were carried out in 332 patients (mean age: 65.22 +/- 15.41, 183 men) and they have a similar diagnosis yield (70.5% vs. 69.6%, p = 0.9). Overall enteroscopy diagnosis yield was higher within patients with a previous positive capsule endoscopy (79.3% vs. 27.9%, p < 0.001). The degree of agreement was very good for polyps (0.89 [95% CI: 0.78-0.99]), good for vascular lesions (0.66 [95% CI: 0.55-0.77]) and tumors(0.66 [95% CI: 0.55-0.76]) and moderate for ulcers (0.56 [95% CI: 0.46-0.67]). Diverticula (0.39 [95% CI: 0.29-0.5]) achieved a fair agreement. The results of CE and DBE differed in 73 patients (22%). CONCLUSIONS: The present study confirms that although overall diagnostic yield by capsule endoscopy and double-balloon enteroscopy is similar, there are many factors which can modify these values, mainly the type of lesion.

Role of double-balloon enteroscopy in malignant small bowel tumors.

AIM: To assess the double-balloon enteroscopy (DBE) role in malignant small bowel tumors (MSBT). METHODS: This is a retrospective descriptive study performed in a single center. All consecutive patients who underwent a DBE with final diagnosis of a malignant neoplasm from 2004 to 2014 in our referral center were included. Patient demographic and clinical pathological characteristics were recorded and reviewed. MSBT diagnosis was achieved either by DBE directed biopsy with multiple tissue sampling, endoscopic findings or histological analysis of surgical specimen. We have analyzed double-balloon enteroscopy impact in outcome and clinical course of these patients. RESULTS: Of 627 patients, 28 (4.5%) (mean age = 60 ± 17.3 years) underwent 30 procedures (25 anterograde, 5 retrograde) and were diagnosed of a malignant tumor. Patients presented with obscure gastrointestinal bleeding (n = 19, 67.9%), occlusion syndrome (n = 7, 25%) and diarrhea (n = 1, 3.6%). They were diagnosed by DBE biopsy (n = 18, 64.3%), histological analysis of surgical specimen (n = 7, 25%) and unequivocal endoscopic findings (n = 2, 7.1%). Gastrointestinal stromal tumor (n = 8, 28.6%), adenocarcinoma (n = 7, 25%), lymphoma (n = 4, 14.3%), neuroendocrine tumor (n = 4, 14.3%), metastatic (n = 3, 10.7%) and Kaposi sarcoma (n = 1, 3.6%) were identified. DBE modified outcome in 7 cases (25%), delaying or avoiding emergency surgery (n = 3), modifying surgery approach (n = 2) and indicating emergency SB partial resection instead of elective approach (n = 2). CONCLUSION: DBE may be critical in the management of MSBT providing additional information that may be decisive in the clinical course of these patients.

Emergency double-balloon enteroscopy combined with real-time viewing of capsule endoscopy: a feasible combined approach in acute overt-obscure gastrointestinal bleeding?

BACKGROUND AND AIM: There are few data concerning emergency double-balloon enteroscopy (DBE) and its usefulness in the management of severe acute obscure gastrointestinal bleeding (OGIB). The aim of this retrospective study was to evaluate emergency DBE and capsule endoscopy (CE) in patients with overt OGIB, analyzing the feasibility of this combined approach. METHODS: Emergency DBE in patients with overt OGIB was defined as performance within 24 h of symptom onset. We reported 27 patients (16 men, mean age: 64.6 ± 17.9 years) with overt severe bleeding who underwent 29 emergency DBE (22 anterograde, 7 retrograde). Of 27 patients, 16 (59.3%) underwent CE with real time (RT) viewing. RESULTS: Patients were diagnosed with the following: Dieulafoy's lesion (DL; n = 11, 40.7%), angioectasia (n = 7, 25.9%), tumors (n = 4, 14.8%), diverticulum (n = 3, 11.1%), ulcers (n = 2, 7.4%). We diagnosed 23 lesions amenable to endoscopic hemostasis and successfully treated 21 of them (77.8%). DL detection rate was statistically higher in the emergency DBE group than in OGIB patients with DBE done 24 h after symptom onset (40.7% vs 0.9%, respectively, P < 0.001). Combined approach with RT viewing by CE correctly modified DBE management in four patients (25%). CONCLUSIONS: Emergency DBE is feasible, safe and effective in acute OGIB and may avoid major surgery, diagnosing and successfully treating most patients. Combined approach with RT viewing by CE is especially useful to identify recurrent bleeding vascular lesions such as DL that may be easily misdiagnosed by non-emergency DBE.

Ultrasonographic and anatomic study of the canine elbow joint.

OBJECTIVE: To (1) assess the canine elbow joint using a high frequency transducer (18 MHz); (2) describe the echogenicity and echo texture of the joint; and (3) correlate the ultrasonographic images with transparent plastinated anatomic sections. DESIGN: Descriptive study. SAMPLE POPULATION: German Shepherd cross-breed dogs (cadavers, n = 10; live dogs, n = 5). METHODS: Elbow joints of 10 adult German Shepherd cross-breed dog cadavers were examined by ultrasonography and then 5 cadavers were selected for use in an anatomic study, in which 2 mm thick sections were obtained in the same planes as in the ultrasonographic protocol. Sections were plastinated using the E-12 plastination method and correlated to the corresponding ultrasonographic images. The elbow joints of 5 German Shepherd adult dogs were assessed by ultrasonography for comparison with cadaver images. RESULTS: Good correspondence of soft tissue and bone structures was obtained between ultrasound images and anatomic sections. There was no difference in the ultrasonographic appearance of elbows of cadavers and live dogs in which the muscular, ligamentous, and bone components of the joints were evaluated. CONCLUSION: This study presents a descriptive comparison of anatomic and ultrasonographic images, which will offer clinicians a more comprehensive understanding of the anatomic structures of the canine elbow joint and serve as reference for further imaging diagnostic studies because of the precise correspondence between anatomic plastinated sections and ultrasonographic images.

An endoscopic technique for treating symptomatic distal jejunum obstruction by leaving the overtube in place.

Double balloon enteroscopy has a limitation for positioning an enteral stent in the distal jejunum through its long, narrow biopsy channel. When the distal end of its overtube is left in place close to the neoplasia with the enteroscope removed, if we push an enteral stent introduction system, it tends to form loops so the techniquecannot be performed with this instrument. However, the double balloon colonoscope has a shorter overtube length and using the same push-and-pull technique we can reach the distal jejunum with this instrument by inserting the delivery stent system without loops through its overtube. We present a patient with neoplastic obstruction in the distal jejunum with resolution of his symptoms after positioning an enteral stent.

Anatomy of the temporomandibular joint in the cat: a study by microdissection, cryosection and vascular injection.

The minute anatomy of the temporomandibular joint (TMJ) is of great clinical relevance in cats owing to a high number of lesions involving this articulation. However, the precise anatomy is poorly documented in textbooks and scientific articles. The aim of this study was to describe, in detail, the TMJ anatomy and its relationship with other adjacent anatomical structures in the cat. Different anatomical preparations, including vascular and articular injection, microdissection, cryosection and plastination, were performed in 12 cadaveric cats. All TMJ anatomical structures were identified and described in detail. A thorough understanding of the TMJ anatomy is essential to understand the clinical signs associated with TMJ disorders, to locate lesions precisely and to accurately interpret the results in all diagnostic imaging techniques.

Effects of pneumoperitoneum and body position on the morphology of abdominal vascular structures analyzed in MRI.

PURPOSE: To analyze the complications of laparoscopy in different vascular structures using magnetic resonance imaging (MRI). MRI has become a key tool in laparoscopic surgery. During these procedures, pneumoperitoneum creation and placing the patient in the surgical position provoke different changes in the splachnic circulation. MATERIALS AND METHODS: Ten pigs were included in the study. MRI studies of the abdominal area were carried out in four different situations of abdominal pressure and body position. RESULTS: Changes in the area of the lumen of the portal vein and the abdominal aorta were analyzed in all situations. A significant reduction in the area of the abdominal aorta was observed after the pneumoperitoneum in supine and anti-Trendelemburg position. The lumen of the portal vein was significantly reduced in all analyzed situations except when placing the patient in anti-Trendelemburg without pneumoperitoneum, in which case the area was increased. CONCLUSION: The creation of pneumoperitoneum provokes morphological changes in the lumen of different abdominal vessels as a consequence of the increase of pressure. Furthermore, the combination of pneumoperitoneum together with the anti-Trendelemburg position results in a more significant reduction of the lumen of the portal vein and the abdominal aorta.

A case of lymphocytic-plasmacytic jejunitis diagnosed by double-balloon enteroscopy in a dog.

A 3 yr old male English setter dog was presented for evaluation of a 6-wk history of intermittent diarrhea. After standard gastroduodenoscopy and colonoscopy showed normal mucosa, double-balloon endoscopy (DBE) was used via both oral and anal approaches. Gross changes consistent with inflammation in the jejunum were seen, and biopsy specimens were obtained. Histologic analysis confirmed a diagnosis of lymphocytic-plasmacytic jejunitis. Clinical remission of the disease occurred after 3 mo of therapy with prednisone, metronidazole, and a novel protein diet. Use of DBE has not been previously reported in dogs with inflammatory bowel disease, and isolated lymphocytic-plasmacytic jejunitis has not been described. The described cases of intestinal inflammatory disease diagnosed by conventional endoscopy were related to pathologic changes in the duodenum, ileum or colon, but not the jejunum. The main advantage of the DBE technique allowed examination of portions of the small intestine (jejunum) that were not commonly accessible by standard endoscopic techniques, and permitted a minimally invasive collection of biopsy samples compared with surgical biopsy. This case highlights the need to consider using DBE in animals with gastrointestinal disorders, whose symptoms are not readily explained by routine tests, conventional endoscopy, and dietary or therapeutic trials.

Maxillary sinus-floor elevation: an animal model.

OBJECTIVES: To find an animal model for modified Caldwell-Luc procedure training. The animal model should have (1) a proper cortical thickness in the lateral wall; (2) a similar morphology and resistance of the Schneiderian membrane in humans; and, finally, (3) an oral approach. MATERIALS AND METHODS: Twelve fresh heads (four Merino sheep, four Murciano-Granadina goats and four Large-White pigs). Two skulls from each of these species were also used. Several three-dimensional imagings from the skulls of each species were acquired using a C-arm. Two fresh heads of each species were used to perform the modified Caldwell-Luc procedure. Two fresh heads of each species were firstly frozen at -30 degrees C for 48 h and then sawed in blocks containing only the target region of the maxillary sinus. RESULTS: The average thickness was 2.03 mm in goat and sheep and 2.80 in pig. Releasing and elevation of the Schneiderian membrane from the sinus floor were easy in the three species. The approach of the maxillary sinus in sheep, goat and pig from the buccal vestibule required a previous surgical enlargement of the buccal vestibule. CONCLUSIONS: In conclusion, the cortical bone thickness and Schneider membrane characteristics in Merina sheep and Murciano-Granadina goat allow a perfect training for the modified Caldwell-Luc procedure. However, the approach from the oral cavity needs, in these species, a previous enlargement of the buccal vestibule. The excessive thickness of the cortical bone restricts the use of pigs for this technique.

How useful is plastination in learning anatomy?

In recent years plastination has begun to revolutionize the way in which human and veterinary gross anatomy can be presented to students. The study reported here assessed the efficacy of plastinated organs as teaching resources in an innovative anatomy teaching/learning system. The main objective was to evaluate whether the use of plastinated organs improves the quality of teaching and learning of anatomy. For this purpose, we used an interdepartmental approach involving the departments of Veterinary Anatomy, Human Anatomy, Veterinary Surgery, and Education Development and Research Methods. The knowledge base of control and experimental student groups was examined before and after use of the fixed or plastinated resources, respectively, to gather information evaluating the effectiveness of these teaching resources. Significant differences (p < 0.001) between control and experimental groups of Human and Veterinary Anatomy were observed in the post-test results. The Veterinary Surgery students had the most positive opinion of the use of plastinated specimens. Using these data, we were able to quantitatively characterize the use of plastinated specimens as anatomy teaching resources. This analysis showed that all the plastinated resources available were heavily used and deemed useful by students. Although the properties of plastinated specimens accommodate student needs at various levels, traditional material should be used in conjunction with plastinated resources.