The rat eustachian tube:Anatomical, histological, and radiological features

Purpose: This study investigated the anatomical and histological characteristics of the rat Eustachian tube(E-tube)and the feasibility of Eustachian tubography in a rat model.Materials and methods: Fifteen male Wistar rats were used in this study, and the bilateral E-tubes of each rat were examined. Ten E-tubes were used for anatomical studies, another ten for histological analysis, and the other ten for Eustachian tubography. Five rats were euthanized and decapitated, and ten E-tubes were dissected to describe the anatomy of the E-tube. Ten E-tube specimens obtained from five other rats were sectioned to investigate Etube histology. Eustachian tubography was performed on the bilateral E-tubes of the other five rats using the trans-tympanic approach.Results: The rat E-tubes consisted of bony and membranous parts. Cartilage and bone tissue covered only the bony part. The E-tubes’ mean diameter and overall length were 2.97 mm and 4.96 mm, respectively. The tympanic orifices’ mean diameter was 1.21 mm. The epithelium of E-tubes was mainly composed of pseudostratified ciliated and goblet cells. Eustachian tubography was successfully performed on both sides of the E-tube for each rat.The technical success rate was 100%, the average running time was 4.9 min, and no procedure-related complications occurred. On tubography images, the E-tube, tympanic cavity, and nasopharynx could be identified because of the visualization of bony landmarks.Conclusion: In this study, we described the anatomical and histological features of rat E-tubes. With the aid of these findings, E-tube angiography was successfully performed using a transtympanic approach. These results will facilitate further investigation of E-tube dysfunction.

Digital radiograph(DR)guided bedside IVC filter placements in patients with intracranial pressure monitors

Purpose:The purpose of this study is to report a single center experience with portable digital radiographically(DR)guided bedside IVC filters placed in intensive care unit(ICU)patients with high ICP and elevated head of bed(HOB).Materials and methods:A retrospective chart review was conducted on all bedside IVC filters placed from January 1,2010 to September 16,2020.Patients with high ICP and elevated head of bed requirements were included.Charts were reviewed for filter type,common femoral vein(CFV)access,filter location,pre procedure imaging,pre and post filter ICPs,glascow coma scale,number of radiographs taken,and filter removal.ICPs were obtained 1 h prior to procedure and 2 h post procedure and analyzed with a paired T test.Filters were placed by reviewing prior CT scan for IVC size,caval variants,renal and iliac veins and vertebral body landmarks.Then,CFV access was obtained and a Bentson wire was advanced 30-40 cm.A radiograph was used to confirm adequate position of the of the wire.The filter sheath was advanced and serial radiographs were used to position the filter sheath at the final predetermined position below the renal veins and above the iliac bifurcation.The filter was deployed,and a radiograph was obtained to confirm filter positioning.Results:A total of 9 DR guided bedside IVC filters were placed(4 Denali,3 Option Elite,2 Celect).Indications included prophylactic placement(n=8)and acute DVT(n=1).The average patient age was 35.8 years(range:18-56 years)CT abdomen and pelvis was used to assess for the level of renal veins in all patients(n=9).No caval variants were encountered on pre-procedural planning.The average pre,intraprocedural,and post procedure intracranial pressure was 16 mmHg,13 mmHg,and 16 mmHg,respectively.Confirmation of placement after final placement was available in 7 patients(4 DR,2 CT and one fluoroscopic examination).Two non-procedural related deaths occurred.Technical success,defined as successful placement of IVC filter at the predetermined level,was achieved in 100%of patients(n=9).The right CFV was used in most patients(n=7).The left CFV was used for access in two patients due to right CFV thrombus(n=1)and existing right femoral venous central line(n=1).The average number of radiographs taken was 5.8(range 4-9).In all cases,filters were placed below the level of the lowest renal vein(n=9).A comparison of pre,during and post intervention ICP pressures is shown in table,2.No differences between pre and post filter ICP was noted(p=0.77).Three filters were later removed.One minor complication was reported,which was filter tilt(23%)in an Option filter.Conclusion:Bedside IVC filters can be safely placed in patients with head trauma and high ICP who are unable to lay supine using portable DR guidance with a high rate of technical success and minimal complications.

Comparative outcomes of Inferior Vena Cava filters placed at bedside using digital radiography versus conventional fluoroscopy

Purpose:To retrospectively assess the outcomes of Inferior Vena Cava(IVC)filters placed in critically ill patients in the ICU at bedside using digital radiograph(DR)guidance with previous cross-sectional imaging for planning,compared to IVC filters placed by conventional fluoroscopy(CF).Method and materials:The cohort consisted of 129 IVC filter placements;48 placed at bedside and 81 placed conventionally from July 2015 to September 2016.Patient demographics,indication,radiation exposures,access site,procedural duration,dwell time,and complications were identified by the EMR.IVC Filter positioning with measurements of tip to renal vein distance and lateral filter tilt were performed when cavograms or post placement CTs were available for review.Statistical analysis was performed using Stata IC 11.2.Results:Technical success of the procedure was 100% in both groups.Procedural duration was longer at the bedside lasting 14.5+/-10.2 versus 6.7+/-6.0 min(p<0.0001).The bedside DR group had a median radiation exposure of 25 mGy(15-35)and the CF group had mean radiation exposure of 256.94 mGy+/-158.6.There was no significant difference in distance of IVC tip to renal vein(p=0.31),mispositioning(p=0.59),degree of filter tilt(p=0.33),or rate of complications(p=0.65)between the two groups.Conclusion:IVCF placement at the bedside using DR is comparable to CF with no statistical difference in outcomes based on IVCF positioning,degree of lateral tilt or removal issues.It decreased radiation dose,but with overall increased procedural time.