Langley, Natalie R.

Background and objectives Studies show variable spread with thoracic erector spinae plane (ESP) injections. Injection sites vary from lateral end of the transverse process (TP) to 3 cm from the spinous process, with many not describing the precise site of injection. This human cadaveric study examined dye spread of ultrasound-guided thoracic ESP block at two needle locations. Methods Ultrasound-guided ESP blocks were performed on unembalmed cadavers. Methylene blue (20 mL, 0.1%) was injected in the ESP at the medial TP at level T5 (medial transverse process injection (MED), n=7) and the lateral end of the TP between T4 and T5 (injection between transverse processes (BTWN), n=7). The back muscles were dissected, and the cephalocaudal and medial-lateral dye spread documented. Results Dye spread cephalocaudally from C4-T12 in the MED group and C5-T11 in the BTWN group, and laterally to the iliocostalis muscle in five MED injections and all BTWN injections. One MED injection reached serratus anterior. Dorsal rami were dyed in five MED and all BTWN injections. Dye spread to the dorsal root ganglion and dorsal root in most injections, though more extensively in the BTWN group. The ventral root was dyed in 4 MED and 6 BTWN injections. Epidural spread in BTWN injections ranged from 3 to 12 levels (median: 5 levels), with contralateral spread in two cases and intrathecal spread in five injections. Epidural spread in MED injections was less extensive (median (range): 1 (0–3) levels); two MED injections did not enter the epidural space. Conclusion An ESP injection administered between TPs exhibits more extensive spread than a medial TP injection in a human cadaveric model.

Studies have shown that prosection and dissection facilitate similar academic outcomes and promote meaningful learning in anatomy laboratory courses. While dissection is the mainstay of many graduate level anatomy curricula, financial and other constraints have increased the use of prosection. This research evaluates student preference for studying different body regions and accomplishing learning outcomes related to content knowledge, teamwork, career preparation, humanistic learning, and wellness. First‐year medical students (n=51) who completed a hybrid prosection and dissection course completed a post‐course survey about their perceptions of the effectiveness of each lab learning modality. Response options included prosection, dissection, no preference (equally effective), and no preference (equally ineffective). A one‐way ANOVA was used to evaluate performance differences on course assessments between students in the hybrid course and students in past years who participated in a dissection based course. The response rate was 51%. Respondents preferred dissection for learning the back (62%), thorax (68%), abdomen (54%), shoulder, axilla, and arm (61.5%), and hip, thigh, and leg (46%). Prosection was favored for the pelvis (perineum 81%, cavity 69%), foot (58%), hand (46%), and head/neck (64%). Students favored dissection for gaining hands‐on skills relevant to surgical practice, appreciating anatomical variation, becoming more comfortable handling the human body, engaging in self‐directed learning, and fostering teamwork. Respondents felt prosection provided more time for independent study and wellness activities. Prosection and dissection were rated equally effective for developing a medical vocabulary, applying anatomical knowledge to clinical conditions, and gaining a 3D appreciation of the body. A hybrid prosection and dissection course was preferred by 73% of respondents, compared to 4% who ranked prosection alone as their preference; no students ranked dissection alone as their first choice. There were no statistically significant differences in academic performance related to teaching methods (F(3,195) = 2.65, p=0.34) between students in the hybrid course and students in previous dissection only courses. Students prefer prosection for learning more spatially complex and intricate regions requiring time‐consuming and skilled dissection. However, learners recognize distinct benefits of dissection for acquiring various technical and non‐technical skills. Hybrid courses should capitalize on the strengths of each method, aligning instructional methods with outcomes and incorporating learner preferences to achieve meaningful, lasting learning.

Forensic anthropologists are often tasked with determining skeletal age‐at‐death to assist law enforcement in identifying skeletal remains. If the remains are skeletally mature, degenerative changes in articular surfaces are typically assessed to determine age. If the skeleton is immature tooth eruption, dental development, and/or epiphyseal union are used to estimate age. Forensic anthropologists derive an age‐at‐death estimate by comparing our assessment of skeletal age indicator(s) to standards derived from skeletal collections of known age‐at‐death. Prior to the establishment of modern skeletal collections such at the William M. Bass Donated Collection at the University of Tennessee, anthropologists developed age estimation techniques using late 19 th and early 20 th century anatomical collections (e.g. the Hamann‐Todd Osteology Collection at the Cleveland Museum of Natural History and Terry Anatomical Collection at the Smithsonian Institution). However, research on Bass Collection skeletons has demonstrated remarkable changes in skeletal morphology in modern Americans compared to early 19 th century birth cohorts, illustrating that standards derived from modern populations are imperative for forensic casework; anatomical collections and archaeological samples are not appropriate reference samples. Age estimation in forensic casework is further complicated by the age distribution of the forensic case population. Forensic cases often involve accidental deaths, homicides, and suicides of individuals from a younger age demographic than natural deaths which comprise many of the reference samples used to derive age estimates. This difference between the age distribution of the reference sample and that of the “target” population leads to ‘age mimicry’, whereby skeletal age‐at‐death may be under‐estimated. This presentation will highlight research that illustrates the impact of secular change and reference sample composition on the accuracy and precision of forensic skeletal age‐at‐death estimation. The documentation of significant changes in skeletal morphology illustrates what evolutionary biologists already know—phenotype is dynamic, not static. These short‐term evolutionary changes in skeletal form have implications for anatomical research beyond the hard tissues. Support or Funding Information National Institute of Justice This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .

Injections of local anesthetic in the fascial planes around the quadratus lumborum muscle (QL blocks) are performed for postoperative pain control after abdominal surgeries. Multiple approaches of injecting anesthetic in and around the QL have been reported (anterior, posterior, transmuscular, intramuscular and lateral QL blocks). These techniques vary in terms of ease of administration and extent of analgesia. The extent of the anesthetic spread from this ultrasound‐guided procedure is influenced by the fascial layers surrounding the QL. A limited number of studies on small samples using varying amounts of anesthetic have left open questions regarding the extent of spread of local anesthetic and the best approach. This study evaluates the local anesthetic spread of two ultrasound‐guided lateral QL block approaches that have proven effective in controlling postoperative pain. A methylene blue‐dyed saline solution (40mL per QL block) is injected into fresh frozen cadavers (n=10). With the patient in supine position, the needle tip is placed at either (1) the anterolateral border of the QL deep to the transversalis fascia or (2) anterior to the transversus abdominus muscle superficial to its aponeurosis. Anatomic dissection of the injection plane is then performed to determine the extent of spread of the dyed saline. We hypothesize that the continuity between the transversalis fascia and the anterior layer of the thoracolumbar fascia (anterior to the QL) facilitates the cranial spread of the anesthetic under the lateral arcuate ligament to the endothoracic fascia. This would explain our observed analgesic effect past the umbilical region to dermatomes in the epigastric region (T7–T8). Understanding how QL fascial planes facilitate anesthetic spread will enable intraoperative administration of these blocks to be tailored to specific procedures and facilitate post‐operative recovery after abdominal operations. Improved methods of intraoperative pain management may reduce post‐operative opioid use and support the medical community in addressing the opioid epidemic in the United States. This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .

Background and objectives The costoclavicular brachial plexus block is performed deep and posterior to the midpoint of the clavicle. There are limited data evaluating the spread of the costoclavicular brachial plexus block. We performed a cadaveric study to evaluate the spread of injectate after a costoclavicular brachial plexus block. Methods Five ultrasound-guided costoclavicular block injections were performed with 20 mL of 0.1% methylene blue. The brachial plexus and its branches were dissected from the level of C4 to the lower axilla. The extent of dye spread was recorded including spread to the phrenic nerve, suprascapular nerve, roots, trunks, divisions, cords and terminal branches of the brachial plexus. Results The dye extended cephalad to the level of the cricoid cartilage in two of the five injections; three injections had dye extending 0.75 cm, 1.5 cm and 2 cm caudad to the level of the cricoid cartilage, respectively. The C7, C8 and T1 nerve roots were stained in all injections. The dye did not extend cephalad to the C5 and C6 nerve roots. All trunks, cords and divisions of the brachial plexus were stained, as was the suprascapular nerve. There was no spread of dye to the phrenic nerve in any of the specimens. Conclusions This cadaveric study demonstrates that ultrasound-guided injection in the costoclavicular space spreads cephalad to the brachial plexus in the supraclavicular space, consistently reaching the suprascapular nerve and all trunks and cords of the brachial plexus, while sparing the phrenic nerve.

Abstract The COVID‐19 pandemic and subsequent social distancing protocols have accelerated the shift to online teaching across the globe. In Science, Technology, Engineering, and Mathematics (STEM) programs this means a shift from face‐to‐face laboratory instruction to self‐directed learning with e‐learning tools. Unfortunately, selecting and integrating an e‐learning tool into a curriculum can be daunting. This article highlights key questions and practical suggestions instructors should consider in choosing the most effective option for their course and learners.

Background and objectives The erector spinae plane (ESP) block is a relatively new interfascial block technique. Previous cadaveric studies have shown extensive cephalocaudal spread with a single ESP injection at the thoracic level. However, little data exist for lumbar ESP block. The objective of this study was to examine the anatomical spread of dye following an ultrasound-guided lumbar ESP block in a human cadaveric model. Methods An ultrasound-guided ESP block was performed in unembalmed human cadavers using an in-plane approach with a curvilinear transducer oriented longitudinally. 20 mL of 0.166% methylene blue was injected into the plane between the distal end of the L4 transverse process and erector spinae muscle bilaterally in four specimens and unilaterally in one specimen (nine ESP blocks in total). The superficial and deep back muscles were dissected, and the extent of dye spread was documented in both cephalocaudal and medial–lateral directions. Results There was cephalocaudal spread from L3 to L5 in all specimens with extension to L2 in four specimens. Medial–lateral spread was documented from the multifidus muscle to the lateral edge of the thoracolumbar fascia. There was extensive dye in and around the erector spinae musculature and spread to the dorsal rami in all specimens. There was no dye spread anteriorly into the dorsal root ganglion, ventral rami, or paravertebral space. Conclusions A lumbar ESP injection has limited craniocaudal spread compared with injection in the thoracic region. It has consistent spread to dorsal rami, but no anterior spread to ventral rami or paravertebral space.

The pervasiveness of flipped classrooms and blended learning has tasked educators with creating content targeting fundamental concepts for asynchronous learning. The visual nature of anatomy subject matter makes video technology particularly well‐suited to convey important relationships. Education technology companies purport that video analytics may provide educators insights into their learners and the effectiveness of their videos. This study examines this claim using analytics recorded by a learning video platform during a 7‐week human anatomy course at the Mayo Clinic Alix School of Medicine (Arizona campus). First‐year medical students (n=48) were provided with daily faculty‐guided videos (n=21) of prosected cadavers [mean length ± SD (mm:ss) = 07:32 ± 3:28]. The videos highlighted structures covered during laboratory sessions. Each video was released less than 36 hours after the associated laboratory session. Video analytic data was recorded, including the number of times a video was viewed and played, average view time and the length of time a student watched a video before closing the page or pausing the video and never restarting it (drop‐off rate). Multiple linear regression analysis was conducted using JMP software to examine the relationship between these video analytic variables and laboratory practical examination performance. None of the video analytic variables, when calculated by individual video or individual student, were significant predictors of practical exam performance [mean exam performance = 88.83%; individual videos, R 2 = 0.024, p = 0.78; individual student, R 2 = 0.113, p = 0.63]. The results of this study are consistent with previous analyses of the educational effectiveness of videos in anatomy courses, in spite of the company’s claim that “videos can improve learning results”. While videos may make education more accessible and engaging, the impact on student learning is difficult to determine using the basic metrics supplied by the video learning platform. Until more sophisticated video analytics become available, such data will remain of limited use to educational researchers.

The clinical significance of valves within gonadal veins is controversial. In males, the absence of valves in the left testicular vein (compared to the right) has been cited as a potential mechanism for varicocele formation in the pampiniform plexus in the scrotum. In females, ovarian vein valve absence or incompetence may lead to pelvic congestion syndrome, a disputed explanation for pelvic, abdominal, and/or flank pain of unknown etiology. One study suggests that females have incompetent valves in dilated veins more frequently than males due to past pregnancies. Furthermore, inconsistencies exist in the reported incidence of gonadal vein valves, though pelvic insufficiency is more thoroughly documented and diagnosed in males than in females. This study assesses the presence, number, and location of gonadal vein valves in male and females. The right and left gonadal veins were evaluated in 13 embalmed cadavers (7 males, 6 females; mean age = 86.3 +/− 6.2 years). Twenty‐four veins were available for dissection; two veins were lost to dissection and therefore omitted. The veins were dissected from the ovary (females) or deep inguinal ring (males) to the point of drainage into the inferior vena cava (right gonadal vein) or left renal vein (left gonadal vein). The veins were incised along the entire length of this course, and the number and location of valves was noted and photographed. Anatomical variation and pathological dilation in the vasculature was also documented. A total of 8 valves were found among the 24 dissections. Valves were present in four of the six females (67%) compared to one out of seven males (14%). The valve in the male was located in the left gonadal vein; the bilateral distribution in females was more randomly patterned. The majority of the valves (87.5%) in females were located distally, adjacent to the ovary, while a single valve was located adjacent to the left renal vein confluence. No dilation was noted in any of the specimens. The male population in this study had a lower incidence of gonadal vein valves than in previous studies. However, the number of valves in female gonadal veins was considerably greater than in males. This finding has not been reported previously, perhaps due to the emphasis on male pelvic congestion as a risk for infertility versus attributing the condition in females to a psychosomatic etiology. The primary limitation of this research is the small sample size. Future work will explore the clinical implications of these preliminary findings in a patient population. Clinical correlation with patients who are suspected or known to suffer from pelvic congestion syndrome may shed further light on the role of gonadal vein valves in vein sufficiency and inform more effective treatment for this poorly understood condition in the female patient population.