Safety of Carotid Canal during Transtympanic Dilatation of the Eustachian Tube: A Cadaver Pilot Study

To assess the safety of Transtympanic balloon dilatation of the cartilaginous proximal Eustachian tube under endoscopic guidance as it relates to the integrity of the carotid canal in cadaver model. Endoscopic guided Transtympanic dilatations of the cartilaginous proximal end of the Eustachian tube were performed in 15 ears of 8 fresh frozen cadaver heads. CT scans were done before and after dilatation. Images were reviewed by two otologists and one radiologist. Balloon catheter placement and dilatation of the proximal Eustachian tube was feasible in all specimens. Endoscopic examination post dilatation showed a consistent increase in the aperture of the proximal cartilaginous tube in all ears. Review of CT images after dilatation showed no evidence of trauma to the carotid canal in all ears instrumented. Endoscopically guided Transtympanic dilatation of the proximal Eustachian tube is not associated with damage to the carotid canal in cadaver model. Level of Evidence: 4.

Endoscopic cochlear implantation: Call for caution

OBJECTIVES/HYPOTHESIS

To assess whether transcanal endoscopic access to the basal turn of the cochlea for cochlear implantation is appropriate.

STUDY DESIGN

Case series study.

METHODS

We reviewed 100 consecutive computed tomographic studies of the sinuses and temporal bone in our institution. We excluded studies that demonstrated evidence of congenital anomalies, chronic ear disease, or inadequate visualization of the cochlea. On axial sections, the angles of the basal turn of the cochlea and of the ear canal in reference to the sagittal plane were recorded as a function of age.

RESULTS

Eighty-four studies were included and 16 were excluded. There was significant variability in the relationship between the ear canal and the basal turn of the cochlea in reference to the sagittal plane. A clear majority of images demonstrated the basal turn of the cochlea to align with a more posterior angle than that of the ear canal.

CONCLUSION

The trajectory provided by posterior tympanotomy aligns more favorably with the basal turn of the cochlea than transcanal access. Endoscopic technique, primarily an ear canal intervention, may not be useful in cochlear implant surgery.

LEVEL OF EVIDENCE

4. Laryngoscope, 126:689-692, 2016.

Transtympanic dilatation of the eustachian tube during chronic ear surgery

CONCLUSION

Evaluation of the protympanic segment of the eustachian tube is feasible during chronic ear surgery. Balloon dilatation of that segment yields a bigger aperture.

OBJECTIVE

To evaluate the feasibility of visualization and balloon dilatation of the protympanic segment of the eustachian tube during chronic ear surgery.

METHODS

This study was carried out on a consecutive case series. All patients undergoing surgical treatment for cholesteatoma or tympanic membrane perforation over a 6-month period of time at a tertiary hospital were evaluated intraoperatively for the ability to visualize the protympanic segment of the eustachian tube, perform balloon dilatation, and then perform visual inspection of the effect of dilatation.

RESULTS

A total of 21 chronic ear procedures were performed; visualization of the protympanic segment was feasible in 12 ears, obstruction was identified in 7 ears, and dilatation was undertaken. Immediate assessment showed increased aperture of the tube in all patients when compared with predilatation findings.

Lower Oncogenic Potential of Human Mesenchymal Stem Cells Derived from Cord Blood Compared to Induced Pluripotent Stem Cells

BACKGROUND

In regenerative medicine, use of each of the mesenchymal stem cells derived from bone marrow, cord blood, and adipose tissue, has several cons and pros. Mesenchymal stem cells derived from cord blood have been considered the best source for precursor transplantation. Direct reprogramming of a somatic cell into induced pluripotent stem cells by over-expression of 6 transcription factors Oct4, Sox2, Klf4, lin28, Nanog, and c-Myc has great potential for regenerative medicine, eliminating the ethical issues of embryonic stem cells and the rejection problems of using non-autologous cells.

OBJECTIVE

To compare reprogramming and pluripotent markers OCT4, Sox-2, c-Myc, Klf4, Nanog, and lin28 in mesenchymal stem cells derived from cord blood and induced pluripotent stem cells.

METHODS

We analyzed the expression level of OCT4, Sox-2, c-Myc, Klf4, Nanog and lin28 genes in human mesenchymal stem cells derived from cord blood and induced pluripotent stem cells by cell culture and RT-PCR.

RESULTS

The expression level of pluripotent genes OCT4 and Sox-2, Nanog and lin28 in mesenchymal stem cells derived from cord blood were significantly higher than those in induced pluripotent stem cells. In contrast to OCT-4A and Sox-2, Nanog and lin28, the expression level of oncogenic factors c-Myc and Klf4 were significantly higher in induced pluripotent stem cells than in mesenchymal stem cells derived from cord blood.

CONCLUSION

It could be concluded that mesenchymal stem cells derived from human cord blood have lower oncogenic potential compared to induced pluripotent stem cells.

Visualization of the eustachian tube lumen with Valsalva computed tomography

OBJECTIVES/HYPOTHESIS

Assess the feasibility of using the Valsalva maneuver to visualize the cartilaginous eustachian tube lumen with computed tomography (CT) in subjects with no ear disease.

STUDY DESIGN

Prospective case series study.

METHODS

Thirty-eight consecutive patients undergoing CT of the sinuses for nose-related complaints with normal radiographic findings consented for a CT of the temporal bone while performing the Valsalva maneuver. Multiplanar reconstruction was performed along the axis of the tube. Images were assessed for visualization of the whole length of lumen of the tube, or partial visualization with ratio of visualized to nonvisualized segments.

RESULTS

The Valsalva maneuver allowed visualization of the whole length of the tube in 27/76 (35%) ears examined. It consistently visualized the distal one-third of the cartilaginous tube in 71/76 (94%) ears. Paradoxical collapse of the eustachian tube was present in three ears along with evidence of poor Valsalva technique.

CONCLUSIONS

Valsalva CT consistently allows visualization of the lumen of the distal one-third of the eustachian tube in a majority of patients with no eustachian tube-related complaints. This technique might be helpful in localizing eustachian tube pathology in patients with obstructive tube symptoms.

Transcatheter coil occlusion for treatment of left internal mammary-anterior descending artery steal phenomenon

A 60-yr-old female with previous bypass surgery including LIMA-LAD graft presented with unstable angina due to steal phenomenon caused by a large pectoral branch of LIMA. Transcatheter coil occlusion of the pectoral branch was successfully performed. This procedure should be considered in similar cases.

Exit block: a new technique for difficult side branch angioplasty

Angioplasty of a stenosis at the origin of a diagonal branch was initially unsuccessful because of the straight course of the anterior descending artery and a sharp bend at the diagonal branch. Therefore, in a second attempt, the anterior descending artery was blocked by inflating a balloon distal to the diagonal branch, thereby facilitating the passage of guidewire and balloon into the diagonal branch.

Effects of nitroglycerin on hemodynamics during rest and exercise in patients with coronary insufficiency

Twenty-three patients exhibiting coronary insufficiency on exercise have been studied at rest and at exercise prior to and following sublingual administration of nitroglycerin. The most consistent and marked effect of nitroglycerin was the reduction in pulmonary artery pressure, total pulmonary resistance, and right ventricular work at rest and during exercise. Our patients were grouped according to the degree of left ventricular failure as indicated by the abnormality of rise in pulmonary artery pressure during exercise. It became evident that nitroglycerin improved left ventricular function in terms of increased output and lessened pulmonary artery pressure in cases in which failure was most severe.