Application of 3D-printed pulmonary segment specimens in experimental teaching of sectional anatomy.

BACKGROUND: Lung cross-section is one of the emphases and challenges in sectional anatomy. Identification of the complex arrangement of intrapulmonary tubes such as bronchi, arteries, and veins in the lungs requires the spatial imagination of students. Three-dimensional (3D) printing has become increasingly used in anatomy education. This study aimed to analyze the effectiveness of 3D-printed specimens used for the experimental teaching of sectional anatomy. METHODS: A digital thoracic dataset was obtained and input into a 3D printer to print multicolor specimens of the pulmonary segment after software processing. As research subjects, 119 undergraduate students majoring in medical imaging from classes 5-8 in the second-year were chosen. In the lung cross-section experiment course, 59 students utilized 3D printed specimens in conjunction with traditional instruction as the study group, while 60 students received traditional teaching as the control group. Preclass and postclass tests, course grading, and questionnaire surveys were used to assess instructional efficacy. RESULTS: We obtained a set of pulmonary segment specimens for teaching. The students in the study group scored better in the postclass test than those in the control group (P < 0.05), and the students in the study group scored higher in satisfaction with the teaching content and spatial thinking for sectional anatomy than those in the control group (P < 0.05). The course grades and excellence rates in the study group exceeded those in the control group (P < 0.05). CONCLUSION: The application of high-precision multicolor 3D-printed specimens of lung segments in experimental teaching of sectional anatomy can improve teaching effectiveness and is worth adopting and promoting in sectional anatomy courses.

Mixed reality navigation training system for liver surgery based on a high-definition human cross-sectional anatomy data set.

OBJECTIVES: This study aims to use the three-dimensional (3D) mixed-reality model of liver, entailing complex intrahepatic systems and to deeply study the anatomical structures and to promote the training, diagnosis and treatment of liver diseases. METHODS: Vascular perfusion human specimens were used for thin-layer frozen milling to obtain liver cross-sections. The 104-megapixel-high-definition cross sectional data set was established and registered to achieve structure identification and manual segmentation. The digital model was reconstructed and data was used to print a 3D hepatic model. The model was combined with HoloLens mixed reality technology to reflect the complex relationships of intrahepatic systems. We simulated 3D patient specific anatomy for identification and preoperative planning, conducted a questionnaire survey, and evaluated the results. RESULTS: The 3D digital model and 1:1 transparent and colored model of liver established truly reflected intrahepatic vessels and their complex relationships. The reconstructed model imported into HoloLens could be accurately matched with the 3D model. Only 7.7% participants could identify accessory hepatic veins. The depth and spatial-relationship of intrahepatic structures were better understandable for 92%. The 100%, 84.6%, 69% and 84% believed the 3D models were useful in planning, safer surgical paths, reducing intraoperative complications and training of young surgeons respectively. CONCLUSIONS: A detailed 3D model can be reconstructed using the higher quality cross-sectional anatomical data set. When combined with 3D printing and HoloLens technology, a novel hybrid-reality navigation-training system for liver surgery is created. Mixed Reality training is a worthy alternative to provide 3D information to clinicians and its possible application in surgery. This conclusion was obtained based on a questionnaire and evaluation. Surgeons with extensive experience in surgical operations perceived in the questionnaire that this technology might be useful in liver surgery, would help in precise preoperative planning, accurate intraoperative identification, and reduction of hepatic injury.

Abdominal ultrasound in amazonian manatee (Trichechus inunguis) (Natterer, 1883) / Ultrassonografia abdominal em peixe boi amazônico (Trichechus inunguis (Natterer, 1883)

Morphophysiological species researches are fundamental, and diagnostic imaging is an excellent technique, already used in wild animals, with great application, not invasive and provide real-time information of each body. Amazonian manatees are on the list of endangered animals classified in the vulnerable category and knowledge of the normal pattern of ultrasound anatomy of organs and tissues is important for the maintenance and well-being of captive specimens contributing to reintroduction actions. The objective of the study was to standardize the examination technique and describe the ultrasound findings of the liver, gallbladder, stomach, urinary bladder and the subcutaneous tissue of the abdominal region in Trichechus inunguis, in order to contribute with the anatomical and sonographic knowledge and assist in the diagnosis and prognosis diseases. The study used 18 animals to describe the normal sonographic anatomy in the abdominal cavity of the Amazonian manatee. During abdominal scan, it was possible to visualize the features of the liver, gallbladder, stomach, urinary bladder obtained satisfactory results in this study. Therefore, other structures were not primarily identified by the reduced time, lots of fat and gases in intestines of animals.

Pesquisas morfofisiológicas em espécies selvagens são fundamentais, e o diagnóstico por imagem é uma excelente técnica, já usada e com grande aplicação, não invasiva e que fornece informações em tempo real de cada órgão. Peixes-boi-amazônico encontram-se na lista de animais ameaçados de extinção classificados na categoria vulnerável e o conhecimento do padrão normal da anatomia ultrassonográfica de órgãos e tecidos é importante para a manutenção e bem-estar de espécimes em cativeiro contribuindo para ações de reintrodução. O objetivo deste estudo foi padronizar a técnica de exame e descrever os achados ultrassonográficos do fígado, vesícula biliar, estômago, vesícula urinária e o tecido subcutâneo da região abdominal em Trichechus inunguis, de modo a contribuir com o conhecimento anátomo-sonográfico e auxiliar no diagnóstico e prognóstico de doenças. O estudo utilizou 18 animais para descrever a anatomia ultrassonográfica normal na cavidade abdominal de peixe-boi amazônico. Durante a varredura abdominal foi possível visualizar as características dos órgãos obtendo resultados satisfatórios neste estudo, concluindo ser uma técnica eficiente para avaliação de determinados órgãos abdominais em peixe-boi amazônico. Entretanto, outras estruturas não foram identificadas principalmente pelo tempo reduzido, muita gordura e gases nos intestinos dos animais.

Genetic factors contributing to late adverse musculoskeletal effects in childhood acute lymphoblastic leukemia survivors.

BACKGROUND: A substantial number of survivors of childhood acute lymphoblastic leukemia (ALL) suffer from treatment-related late adverse effects. While multiple studies have identified the effects of chemotherapeutics and radiation therapy on musculoskeletal outcomes, few have investigated their associations with genetic factors. METHODS: Here we analyzed musculoskeletal complications in relation to common and rare genetic variants derived through whole-exome sequencing of the PETALE cohort. Top-ranking associations were further assessed through stratified and multivariate analyses. RESULTS: DUOX2 variant was associated with skeletal muscle function deficit, as defined by peak muscle power Z score ≤ -2 SD (P = 4.5 × 10-5 for genotyping model). Upon risk stratification analysis, common variants in the APOL3, COL12A1, and LY75 genes were associated with Z score ≤ -2 SD at the cross-sectional area (CSA) at 4% radial length and lumbar bone mineral density (BMD) in high-risk patients (P ≤ 0.01). The modulation of the effect by risk group was driven by the interaction of the genotype with cumulative glucocorticoid dose. Identified variants remained significant throughout multivariate analyses incorporating non-genetic factors of the studied cohort. CONCLUSION: This exploratory study identified novel genetic variants associated with long-term musculoskeletal impairments in childhood ALL survivors. Replication in an independent cohort is needed to confirm the association found in this study.

Advanced-sectioned images obtained by microsectioning of the entire male body.

Realistic two-dimensional (2D) and three-dimensional (3D) applications for anatomical studies are being developed from true-colored sectioned images. We generated advanced-sectioned images of the entire male body and verified that anatomical structures of both normal and abnormal shapes could be visualized in them. The cadaver was serially sectioned at constant intervals using a cryomacrotome. The sectioned surfaces were photographed using a digital camera to generate horizontal advanced-sectioned images in which normal and abnormal structures were classified. Advanced-sectioned images of the entire male body were generated. The image resolution was 3.3 × 3.3 fold better than that of the first sectioned images obtained in 2002. In the advanced-sectioned images, normal and abnormal structures ranging from microscopic (≥0.06 mm × 0.06 mm; pixel size) to macroscopic (≤473.1 mm × 202 mm; body size) could be identified. Furthermore, the real shapes and actual sites of lung cancer and lymph node enlargement were ascertained in them. Such images will be useful because of their true color and high resolution in digital 2D and 3D applications for gross anatomy and clinical anatomy. In future, we plan to generate new advanced-sectioned images of abnormal cadavers with different diseases for clinical anatomy studies.

CT Attenuation and Cross-sectional-area Index of the Pectoralis Are Associated With Prognosis in Sarcoma Patients.

BACKGROUND/AIM: To identify prognostic imaging biomarkers from staging chest computed tomography (CT) in patients with sarcomas. PATIENTS AND METHODS: CT scans for baseline staging, and surveillance 1-year CT scans in patients newly diagnosed with sarcoma were evaluated. Pectoralis muscle area (PMA), pectoralis muscle index (PMI) and pectoralis CT attenuation density (PMT) were measured. Cox proportional-hazard models were used to determine the association with progression-free survival (PFS) and overall survival (OS). RESULTS: There were 147 patients (53.1% male) who were followed for a median 1,414 days (range=219-4851 days). Approximately 47.6% (70/147) of patients progressed and 29.9% (44/147) died. Multivariable Cox-proportional hazards models adjusting for gender, tumor grade and chemotherapy treatment showed that a higher baseline PMT and baseline PMI were associated with increased OS. CONCLUSION: Higher baseline PMI and PMT are associated with increased overall survival in patients with sarcoma.

A sling of a normal right inferior vena cava around the abdominal aorta.

Variations in the anatomy of inferior vena cava (IVC) may have important clinical implications. In-depth knowledge of its embryology and variations are of fundamental importance to prevent any potential medical complications related to anatomic variations of the IVC. In this article, we described a previously unreported, to the best of our knowledge, a variation of IVC. In the case we presented, the IVC was seen almost completely encircling the abdominal aorta. We decided to call this anatomic variation as "a sling of a normal right IVC around the abdominal aorta". Cross-sectional imaging is a prompt and highly reliable method to evaluate IVC anatomy and may have significant clinical importance to prevent any potential complications related to IVC during surgery or interventional radiology procedures.

The fibula and talus position difference in functional and mechanical ankle instability: MRI findings.

PURPOSE: This study aimed to use MRI to evaluate the fibula and talus position difference in functional and mechanical ankle stability patients. METHODS: 61 and 68 patients with functional and mechanical instability, and 60 healthy volunteers were involved. Based on the axial MRI images, the rotation of the talus was identified through the Malleolar Talus Index (MTI). The position relative to the talus (Axial Malleolar Index, AMI) and medial malleolus (Intermalleolar Index, IMI) were used to evaluated the displacement of the fibula. RESULTS: Post hoc analysis showed that the values of malleolar talus index was significantly larger among mechanical instability (89.18° ± 2.31°) than that in functional instability patients (86.55° ±61.65°, P < 0.001) and healthy volunteers (85.59° ± 2.42°, P < 0.001). The axial malleolar index of the mechanical instability patients (11.39° ± 1.41°) were significantly larger than healthy volunteers (7.91° ± 0.83°) (P < 0.0001). There were no statistically significant differences in the above three indexes between the functional instability patients and healthy volunteers. CONCLUSION: The functional instability patients didn't have a posteriorly positioned fibula and an internally rotated talus. The malleolar talus index was significantly larger among mechanical instability patients than that in functional instability patients. Increased malleolar talus index may become a new indirect MRI sign for identifying functional and mechanical instability patients.

Differential estrogen-related responses in myofiber cross-sectional area of pelvic floor muscles in female rats.

OBJECTIVE: To determine the role of estrogens in myofiber cross-sectional area (CSA) of the pubococcyegeus (Pcm) and iliococcygeus muscles (Icm). METHODS: In Experiment 1, we excised the Pcm and Icm during the metestrus and proestrus stages of the estrous cycle to measure the myofiber CSA. In Experiment 2, we allocated other rats into the following groups: sham (Sh), ovariectomized (OVX), OVX plus 1,4,6-androstatriene-3,17-dione (ATD; OVX + ATD), an aromatase inhibitor, and OVX plus estradiol benzoate (OVX + EB). We carried out appropriate statistical tests to determine significant differences (p ≤ 0.05) in variables measured for both Experiments. RESULTS: The Pcm myofiber CSA at proestrus was higher than at metestrus, while the Icm myofiber CSA did not change. Ovariectomy increased the Pcm myofiber CSA, which was exacerbated with the ATD administration. The EB supplementation successfully reversed the ovariectomy-induced enlargement of the CSA. No significant changes were detected for the Icm myofiber CSA. CONCLUSIONS: Fluctuating ovarian steroid levels at the estrus cycle significantly influence the CSA myofiber of the Pcm but not that of the Icm. Estrogen actions, having a gonadal or extragonadal origin, influence importantly the CSA of the Pcm.

The Effect of ACL Reconstruction on Involved and Contralateral Limb Vastus Lateralis Morphology and Histology: A Pilot Study.

Quadriceps muscle weakness is a commonly reported issue post anterior cruciate ligament reconstruction (ACLR), with minimal information related to skeletal muscle morphology following surgery. The purpose is to examine the morphological and functional differences in the vastus lateralis muscle from patient's ACLR and contralateral leg. Three physically active ACLR participants were recruited and secured to a dynamometer to perform maximal voluntary isometric knee extension contractions (MVIC) of the ACLR and contralateral limb. Muscle biopsies of the ACLR and contralateral vastus lateralis were performed, then sectioned, and stained for myosin isoforms to determine fiber type. Confocal images were acquired, and ImageJ software was used to determine the fiber type and cross-sectional area (CSA). There was a significant reduction in CSA of the type IIa and type IIx muscle fiber cells between healthy (IIa: 7,718 ± 1,295 µm2; IIx; 5,800 ± 601 µm2) and ACLR legs (IIa: 4,139 ± 709 µm2; IIx: 3,708 ± 618 µm2) (p < 0.05), while there was no significant difference in knee extension MVIC torque between legs (healthy limb: 2.42 ± 0.52 Nm/kg; ACLR limb: 2.05 ± 0.24 Nm/kg, p = 0.11). The reduction in the cross-sectional area of the ACLR type II fibers could impair function and increase secondary injury risk.

Predictive Factors for Hamstring Autograft Diameter in Anterior Cruciate Ligament Reconstruction.

Multiple studies found hamstring tendon (HT) autograft diameter to be a risk factor for anterior cruciate ligament (ACL) reconstruction failure. This study aimed to determine which preoperative measurements are associated with HT autograft diameter in ACL reconstruction by directly comparing patient characteristics and cross-sectional area (CSA) measurement of the semitendinosus and gracilis tendon on magnetic resonance imaging (MRI). Fifty-three patients with a primary ACL reconstruction with a four-stranded HT autograft were included in this study. Preoperatively we recorded length, weight, thigh circumference, gender, age, preinjury Tegner activity score, and CSA of the semitendinosus and gracilis tendon on MRI. Total CSA on MRI, weight, height, gender, and thigh circumference were all significantly correlated with HT autograft diameter (p < 0.05). A multiple linear regression model with CSA measurement of the HTs on MRI, weight, and height showed the most explained variance of HT autograft diameter (adjusted R 2 = 44%). A regression equation was derived for an estimation of the expected intraoperative HT autograft diameter: 1.2508 + 0.0400 × total CSA (mm2) + 0.0100 × weight (kg) + 0.0296 × length (cm). The Bland and Altman analysis indicated a 95% limit of agreement of ± 1.14 mm and an error correlation of r = 0.47. Smaller CSA of the semitendinosus and gracilis tendon on MRI, shorter stature, lower weight, smaller thigh circumference, and female gender are associated with a smaller four-stranded HT autograft diameter in ACL reconstruction. Multiple linear regression analysis indicated that the combination of MRI CSA measurement, weight, and height is the strongest predictor.

CT assessment of preoperative nutritional status in gastric cancer: severe low skeletal muscle mass and obesity-related low skeletal muscle mass are unfavorable factors of postoperative complications.

BACKGROUND: Computed tomography (CT) has become an important technique for assessing skeletal muscle mass. Low skeletal muscle mass (LSMM) is considered an unfavorable factor for postoperative complications in patients with gastric cancer (GC). METHODS: Patients who underwent laparoscopic gastrectomy for GC were included. Skeletal muscle mass at the third lumbar vertebra (L3) level was measured by preoperatively using CT. The patients were divided into an LSMM group and a non-LSMM group and the intergroup differences were analyzed. Furthermore, we divided the LSMM group into mild and severe LSMM subgroups. The study also analyzed the influence of obesity-related LSMM on postoperative complications. RESULTS: A total of 409 patients were enrolled; of them, 265 had LSMM and 41 had severe LSMM. LSMM was associated with age, body mass index, and Nutritional Risk Screening 2002 score. In the multivariate analysis, LSMM was not related to postoperative complications. Further analysis revealed that severe LSMM was a risk factor for postoperative complications. The study also found that the risk of postoperative complications was significantly increased in patients with obesity-related LSMM. CONCLUSIONS: LSMM was not significantly correlated with postoperative complications. Severe LSMM and obesity-related LSMM are unfavorable factors for postoperative complications with GC after gastrectomy.

Effects of type II SLAP lesion repair techniques on the vascular supply of the long head of the biceps tendon: a cadaveric injection study.

BACKGROUND: One option for the treatment of type 2 superior labral anterior to posterior (SLAP) lesions is arthroscopic repair. However, the fact that the vascular supply of the proximal long head of the biceps tendon (LHBT) arises from the soft tissue near the SLAP repair site must also be considered. The aims of this study were to evaluate the vascular channel of the proximal long head biceps tendon and to compare potential damage to the vascular supply with alternative SLAP techniques. METHODS: Forty-five fresh cadaveric shoulders were divided into 3 groups: 9 shoulders each for the normal group and the created SLAP group, and 27 shoulders for the repaired SLAP group. SLAP group shoulders were repaired using one of 3 techniques: 2 anchors with simple sutures, 1 anchor with double sutures, or 1 anchor with a horizontal mattress suture. India ink was then injected into the acromial branch of the thoracoacromial artery. The proximal LHBT was resected for a histologic cross-sectional study. The intratendinous vascular distance was measured and compared among the groups. RESULTS: The vascular supply of the proximal LHBT arises from soft tissue lying anterior and dorsal to the tendon origin. In the normal shoulders, the average intratendinous vascular distance was 16.9 ± 1.5 mm (95% confidence interval: 15.8-18.1). A comparison of nonrepaired SLAPs with each of the repair techniques found that using 2 anchors with simple sutures showed no significant difference in vascular distance (P = .716), whereas the other techniques showed a significant disruption of the blood supply. The differences in vascular distance among the 3 repair techniques were statistically significant (P = .0001). CONCLUSIONS: The main vascular supply of the proximal LHBT comes from the anterior-dorsal direction. Some SLAP repair techniques can disrupt vascularization; however, the technique using 2 anchors with simple sutures, 1 anchor 3 mm anterior to the anterior border and 1 at the posterior border of the tendon, can preserve the vascularization of the LHBT.

Anatomical deviations of vertebral artery in hemifacial spasm: a quantitative study.

PURPOSE: There exist different opinions on whether the anatomical laterality of vertebral artery (VA) is related to the unilateral onset of hemifacial spasm (HFS). In this study, we intended to qualitatively explore the potential correlation between the anatomical deviations of VA and the clinical characteristics of HFS. METHODS: Two hundred and forty patients who underwent microvascular decompression for HFS between January 2018 and December 2019 were recruited. Clinical data including medical records and preoperative MRI images were retrospectively reviewed. A score system was specially designed for VAs to illustrate their distribution, and a score-weighted cross-sectional area of VA was proposed to represent the relative thickness of VA on each side. Then, the anatomical deviations of VA were comparatively analyzed between the symptomatic side and asymptomatic side and between VA-involved cases and non-VA-involved cases. RESULTS: The score and weighted cross-sectional area (WCSA) of VA in symptomatic side were significantly greater than those in asymptomatic side (P = 0.000, P = 0.000). And in symptomatic side, the score and WCSA of VA in VA-involved cases were significantly greater than those in non-VA-involved cases (P = 0.000). Moreover, with higher score (P = 0.000) and greater WCSA (P = 0.001) on the left side, the VA-involved cases showed a preference (74%) of left HFS. CONCLUSIONS: In HFS, the symptomatic side tends to have an ipsilaterally deviated and relatively larger VA, especially in VA-involved cases. And it is the VA-involved cases that are prone to have a prevalence of left HFS, but not the non-VA-involved cases.

Facial Aging: A Quantitative Analysis of Midface Volume Changes over 11 Years.

BACKGROUND: Anatomical studies have identified separate superficial and deep facial fat compartments, leading some to theorize that volume loss from the deep midface causes overlying superficial fat pseudoptosis. Unfortunately, a paucity of evidence exists regarding whether facial fat volume is truly lost with age and, if so, whether it is lost equally or differentially from the superficial and deep compartments. The aim of this study was to quantify volume changes occurring with age within the superficial, deep, and buccal fat compartments of the midface. METHODS: A retrospective longitudinal study was performed evaluating individuals aged 30 to 65 years who underwent facial computed tomography followed by facial computed tomography greater than or equal to 10 years later. Superficial midface, deep midface, and buccal fat volumes were quantified using Horos radiology software. RESULTS: Nineteen subjects met inclusion criteria. Mean total fat volume decreased significantly from 46.47 cc to 40.81 cc (p < 0.01). The mean superficial and deep fat volumes both decreased significantly from 26.10 cc to 23.15 cc (p < 0.01) and from 11.01 cc to 8.98 cc (p < 0.01), respectively. No significant difference was observed in buccal fat volume over time (9.36 cc to 8.68 cc; p = 0.04). Patients lost an average of 11.3 percent of their initial superficial fat volume and 18.4 percent of their initial deep fat volume. CONCLUSIONS: Significant volume loss was observed from both superficial and deep facial fat compartments over a mean 11.3 years. Patients lost a greater percentage of deep facial fat volume, providing support for the theory of pseudoptosis caused by deep midface fat loss.

Echography analysis of musculoskeletal, heart and liver alterations associated with endothelial dysfunction in obese rats.

BACKGROUND: Modern imaging plays a central role in the care of obese patients, and there is an integral focus on its use and accessibility in individuals who have alterations of various in various organs. The objective in this study was to perform an echographic analysis of musculoskeletal system disorders, endothelial dysfunction and the left ventricle (LV) in obese rats. METHODS: Sprague Dawley rats (250 ± 5 g) were obtained and divided into two groups: the control (C) group was fed with a standard diet, and the obese (Ob) group was fed hyper caloric diet with a high fructose-fat content for 4 months. Body weight, cholesterol, triglycerides, glucose, inflammatory cytokines and adhesion molecules (ICAM-1, VCAM-1) were measured. Additionally, two-dimensional echocardiography, abdominal ultrasound and musculoskeletal system studies were performed in the lower extremities. RESULTS: The body weight in the Ob group was increased compared to that in the control group, (p < 0.001); in addition, increased glucose, cholesterol and triglyceride concentrations (p < 0.05) as well as increased levels of the adhesion molecules ICAM-1 and, VCAM-1 (p < 0.01) were found in the Ob group vs the C group. On ultrasound, 75% of the Ob group presented fatty liver and distal joint abnormalities. CONCLUSION: Obese rats exhibit endothelial dysfunction and musculoskeletal changes, also, fatty liver and articular cysts in the posterior region of the distal lower- extremity joints.

Evaluation of the anastomoses between the ophthalmic artery and the middle meningeal artery by superselective angiography.

PURPOSE: There are three anastomoses between the ophthalmic artery (OA) and the middle meningeal artery (MMA): the anastomotic branch with MMA, the recurrent meningeal branch and the anterior falx artery. We aimed to evaluate the anastomotic branches between the OA and the MMA on superselective angiograms of pediatric patients with retinoblastoma. MATERIALS AND METHODS: We evaluated 126 angiographies performed on children with retinoblastoma. The mean diameter and angiographic visibility percentage of the anastomotic branches between the OA and the MMA were examined according to age group and sex. RESULTS: The mean diameter of anastomotic branch with MMA was measured 0.58 ± 0.13 mm and we found this branch in 15 of 126 angiographic images (11.9%). We detected the recurrent meningeal branch in 47 of total images (37.3%). The recurrent meningeal branch arose 85.1% from the lacrimal artery, 8.5% from the anastomotic branch with MMA and 6.4% directly from the OA. The mean diameter of this artery was measured 0.21 ± 0.06 mm. Anterior falx artery was found in 86 of 126 angiographic peocedures (68.3%) and the mean diameter was measured 0.22 ± 0.06 mm. CONCLUSION: Knowledge of the anastomoses between the OA and the MMA system are all necessary to perform safe and successful endovascular and surgical procedures involving the orbital region.

Flip Technology for Assessing Esophageal Structural and Motor Disorders: a Skeptic's View.

PURPOSE OF REVIEW: Functional lumen impedance (FLIP) technology has become commercially available to assess structural and motor abnormalities of the esophagus. Increasing numbers of papers have described novel findings with this technology. This review examines the validity of the FLIP technique, how it compares with existing diagnostic modalities, and evidence to date on diagnostic accuracy. RECENT FINDINGS: FLIP studies require deep sedation at the time of endoscopy to complete. They assess a simulated state of esophageal obstruction in only a distal part of the esophagus rather than deglutitive motor function of the entire esophagus. The available normative dataset is small and not matched to the older age of patients typically being evaluated. The test-retest agreement in health and disease is unknown, as is the operator dependence on performing and interpreting findings. Studies to date have largely excluded patients with structural disorders, which FLIP cannot reliably distinguish from motor disorders. FLIP is an expensive technology that has been made clinically available without its true utility being established. For FLIP to be deemed a device ready for widespread clinical use, additional studies on validity, diagnostic accuracy, and outcomes need to be performed. Prospective clinical studies need to include all patients and assess the incremental cost-effectiveness of FLIP over more innovative use of existing technology, such as high-resolution manometry with provocative challenges.