Laboratory Procedures and Management
Jeremy R. Jass in Understanding Pathology, 2020
Large specimens of hollow organs, such as the gut, are opened with scissors, washed in a sink (a short exposure to tap water is not harmful) and pinned out on a board, together with a tag indicating the patient’s name and laboratory number. The board is then turned upside down and floated in a large tank of fixation fluid. Detailed dissection is usually deferred to the following day. Dissection involves the selection of small samples of tissue for microscopic examination. These pieces may amount to only a small fraction of the entire specimen, but they should be representative of the organ as a whole and provide all the diagnostic information that is needed. The samples are placed in plastic cassettes with a snap on lid. There are small perforations in the cassette and lid to allow solutions to percolate around the selected tissue when it is processed further. The patient’s laboratory number is pencilled onto the edge of the cassette and is not worn off. The cassettes will remain in formaldehyde solution for a further period of time to ensure that the tissue samples are thoroughly fixed. Care must be taken so that clusters of malignant cells from one specimen are not inadvertently transferred to the following patient’s tissue sample. To prevent such potentially misleading ‘carry over’ all surfaces used in dissection are cleaned meticulously between cases.
Test Paper 2
Teck Yew Chin, Susan Cheng Shelmerdine, Akash Ganguly, Chinedum Anosike in Get Through, 2017
A 66-year-old man with central chest pain radiating to the back is brought into the A&E department. A chest X-ray is read as unremarkable and a contrast CT is organised. The contrast CT shows an acute dissection flap in the aortic arch at the origin of the left common carotid trunk extending through the descending thoracic aorta, into the proximal abdominal aorta at the level of the renal arteries. Which of the following best classifies this dissection type? DeBakey 1 – Stanford ADeBakey 2 – Stanford ADeBakey 3 – Stanford ADeBakey 1 – Stanford BDeBakey 2 – Stanford B
Aortic Surgery
Theo Kofidis in Minimally Invasive Cardiac Surgery, 2021
Zone 3 pathologies involve the diseases of the proximal portion of descending aorta. A hybrid approach for this group of patients may require debranching of the left subclavian artery, and zone 2 (or partially zone 3) is used as a landing zone for stent graft implantation (Figure 14.2.9 and Figure 14.2.10). One of the most common pathologies at this region is type B dissection. The entry tear of the dissection is usually located in the immediate vicinity of the orifice of the left subclavian artery. Treatment in selected cases may require debranching of the left subclavian artery. In some patients the dissected segments may extend proximally to the arch. In such cases zone 1 or 2 repair may be needed to secure a safe proximal landing zone according to the extent of the dissected segment [14,15].
Anatomical course of the lateral femoral cutaneous nerve with special reference to the direct anterior approach to total hip arthroplasty
Published in Modern Rheumatology, 2020
Masahiko Sugano, Junichi Nakamura, Shigeo Hagiwara, Takane Suzuki, Takayuki Nakajima, Sumihisa Orita, Tsutomu Akazawa, Yawara Eguchi, Yohei Kawasaki, Seiji Ohtori
The following dissection protocol was applied. Each cadaver was first placed on a dissection table in a supine position. Along the inguinal ligament, an incision was made from the anterior superior iliac spine (ASIS) to the pubic tubercle, followed by longitudinal dissection of the center of the anterior thigh from the center of the inguinal ligament. The LFCN and its branches were identified by their origin from the pelvis at the level of the inguinal ligament. All nerve branches of the LFCN were carefully traced distally in the subcutaneous tissue of the proximal aspect of the thigh. The following distances of Ropars et al. [12] were measured using a ruler (Figure 1). (a) The distance from the midpoint of the ASIS to the LFCN at the level of the inguinal ligament. When the nerve divided proximally to the inguinal ligament into two main femoral and gluteal branches their distance from the ASIS was measured. Whether each nerve passed through or under the inguinal ligament was recorded. (b) The distance from the midpoint of the ASIS to the points where the LFCN branches crossed the anterior margin of the TFL was recorded and the distance from the ASIS to this point was measured. (c) The distance from the lateral epicondyle of the femur to the lateral malleolus of the ankle (lower leg length) was measured.
Do we really need cadavers anymore to learn anatomy in undergraduate medicine?
Published in Medical Teacher, 2018
P. G. McMenamin, J. McLachlan, A. Wilson, J. M. McBride, J. Pickering, D. J. R. Evans, A. Winkelmann
Our recently published meta-analysis on anatomy laboratory pedagogies (Wilson et al. 2018) is a key evidence-based study, which lays the groundwork for many of the arguments to follow. In summary, the meta-analysis conducted 4 sub-analyses that investigated dissection vs prosection, dissection vs. models/modeling, dissection vs digital media, and dissection vs hybrid approaches. The overall goal of this study was to understand the effectiveness of dissection compared to these other approaches. Upon reviewing over 3000 records, a total of 27 studies were included in the final analysis. Across those 27 studies (which included over 7000 participants), the meta-analysis detected no effect on learner performance. In other words, students’ short-term knowledge gains in anatomy were equivalent regardless of being exposed to dissecting cadavers or not.
Relationship between subarachnoid and central canal hemorrhage and spasticity: A first experimental study
Published in The Journal of Spinal Cord Medicine, 2021
Selim Kayaci, Mehmet Dumlu Aydin, Baris Ozoner, Tayfun Cakir, Orhan Bas, Sare Sipal
Stereological analysis of histopathologic data was conducted according to the principles previously stated, and the physical dissector method was used to evaluate the number of neurons in the spinal cord.17 The DNDs in the GM of spinal cord were calculated using stereological methods. Apoptosis of the neurons in the anterior horn of spinal cord confirmed the occurrence of neuronal degeneration. Data were obtained from dissector pairs consisting of parallel sections taken at known intervals. Two tagged consecutive sections obtained from the tissue samples (dissector pairs) were mounted on each slide. Twenty dissector pairs were obtained from each block for neuronal analysis. A counting frame was placed on the consecutive section photographs on the PC to conduct neuron count. Before the new sections were obtained, the reference and examination sections were reversed to double the number of dissection pairs (see Fig. 5(A and B)). The average numerical density of the spinal cord neurons per cubic millimeter (NvSC) was estimated according to the formula below.
Related Knowledge Centers
- Anatomy
- Cadaver
- Forensic Medicine
- Blood Vessel
- Pathology
- Autopsy
- Formaldehyde
- Morgue
- Computational Anatomy
- Nerve