Power Doppler imaging of the fetal upper aerodigestive tract using a 4-point standardized evaluation: preliminary report

[Sonographic analysis of swallowing in the cervical section of the esophagus]

BACKGROUND

Dysphagia is a common symptom reported by patients in various medical fields, raising the question of diagnosis. In addition to otorhinolaryngologic examination with a mirror, the current gold standards videofluoroscopy and fiber optic endoscopic evaluation of swallowing (FEES) are available. Ultrasound is frequently used in everyday clinical practice, although its application for swallowing diagnostics needs addressing.

MATERIALS AND METHODS

Between April 2012 and February 2014, 81 subjects (age 19-66 years) with no indication of a swallowing disorder were sonographically examined. The anatomic representation of swallowing structures was evaluated and videos of the cervical part of the esophagus during swallowing of different consistencies (saliva, water, jelly) were recorded and analyzed. In a pilot study, the examination was tested on 3 dysphagia patients.

RESULTS

The base of the tongue, the intralaryngeal structures, the cervical spine, and the thyroid glands were well visualized. Sonographic representation of the cervical esophagus section was particularly successful. Its length could be detected at 5.78 ± 1.66 cm, the diameter measured at 0.88 ± 0.10 cm. Sonographic inspection of the sinus piriformis was most difficult; it could not be seen in 39.5% of cases. Visualization of the sinus piriformis was better in cases of normal weight and age <25 years (odds ratios 5.6 and 11.3, respectively). In the examination of patients with a swallowing disorder, three different pathologies (Forestier's disease, esophageal stenosis, and motor neuron disease) were identified as the cause of complaints.

CONCLUSION

Sonography enables very good visualization of swallowing and evaluation of the cervical esophagus. Where available, the otorhinolaryngologist should consider ultrasound as a diagnostic option, as it enables repeated evaluation of swallowing and can complement previously available diagnostic tools.

Assessment of fetal swallowing with gray-scale and color Doppler sonography

OBJECTIVE

Our study was focused on the evaluation of fluid dynamics to assess the value of gray-scale and color Doppler sonography for evaluating the development of fetal swallow-related movements from early gestation until birth.

MATERIALS AND METHODS

We examined 56 fetuses from weeks 15-39 of gestation. Each fetus was examined throughout four distinct periods of gestation: weeks 15-18, 22-25, 30-34, and 37-39. During the examination, seven gray-scale sonography or color Doppler sonography patterns and their prevalence were considered.

RESULTS

Mandibular and/or labial movements (chi2 = 56.4, p < 0.0001) and their rhythmic activity (chi2 = 41.4, p < 0.0001) were seen on gray-scale sonography in an increasing percentage of fetuses as gestational age increased. Doppler findings showed an increase for nose-mouth flow signals (chi2 = 57.6, p < 0.0001), larynx-esophagus flow signals (chi2 = 13.2, p = 0.0003), and effective swallowing (chi2 = 36.0, p < 0.0001) as gestational age increased.

CONCLUSION

There is a trend in the fetus toward development of increased coordinated movement and more functional nose-mouth flow with increasing gestational age: 32.1% of the 56 fetuses in our series achieved effective swallowing at 37-39 weeks, on the basis of gray-scale and Doppler evaluations. Knowledge of the physiologic mechanism involving swallowing development may allow identification of altered swallow-related movements in fetuses with malformations of the digestive tract or with neurologic disorders.

Repeatability of the sonographic assessment of fetal sucking and swallowing movements

OBJECTIVE

To test the repeatability of sonography in the assessment of fetal sucking and swallowing movements.

METHODS

Eighty normal fetuses of pregnant women with no systemic abnormalities were examined sonographically at 30-38 weeks of gestation. Sucking and swallowing movements were observed for 15 min and the face was visualized in frontal and lateral views. The examinations were recorded for later analysis by two independent observers and the 95% limits of agreement (Bland and Altman) method was used for inter- and intraobserver comparison.

RESULTS

The mean +/- SD number of swallowing movements, sucking bursts and total sucking movements recorded by Observer 1 were 8.3 +/- 4.7, 9.9 +/- 9.3 and 35.8 +/- 48.0 and the equivalent values for Observer 2 were 8.2 +/- 4.8, 9.8 +/- 9.3 and 36.4 +/- 49.0, respectively. The mean (95% limits of agreement) interobserver difference was 0.1 (-1.4; 1.6), 0.1 (-2.2; 2.3) and -0.6 (-9.0; 7.9), and the mean (95% limits of agreement) intraobserver difference was 0.4 (-3.1; 3.9), 0.1 (-2.0; 2.2) and 1.0 (-10.7; 12.7) for swallowing movements, sucking bursts and total sucking movements, respectively.

CONCLUSIONS

The high degree of intra- and interobserver repeatability disclosed in the sonographic analysis of fetal sucking and swallowing movements supports the applicability of sonographic assessment in normal fetuses.

Ultrasound evaluation of the normal fetal pharynx

OBJECTIVE

To obtain normative data for fetal pharyngeal diameter and to investigate the ability to visualize pharynx at different gestational ages during routine prenatal sonography.

METHODS

Sonographic studies were performed in 292 consecutive pregnant women. The diameters of the pharynx were measured and our ability to visualize pharynx was evaluated at different gestational ages.

RESULTS

Sonographic measurements of the pharyngeal diameter were obtained in 153 of the 292 fetuses. The diameter of the pharynx increased from a mean of 4.5+/-0.53 mm at 16 weeks to 9.1+/-1.72 mm at 36 weeks. Pharyngeal diameters showed a significant positive relationship with advancing gestational age (p<0.0001, R2=0.571). The differences in visualization among different gestational age groups were found to be significant (p<0.05 by Chi-Square).

CONCLUSION

This study reports normative data for fetal pharyngeal diameter. Pharyngeal measurements were similar to previous reports in the literature. Our success in visualizing the pharynx was best between 21 and 30 weeks of gestation. This period might be the optimum time for evaluating fetal pharynx.

Emergence of oropharyngeal, laryngeal and swallowing activity in the developing fetal upper aerodigestive tract: an ultrasound evaluation

The developing fetal upper aerodigestive system provides the structural support for respiratory and ingestive functions necessary to sustain life at birth. This study investigated prenatal development of upper aerodigestive anatomy and the association of emerging functions as predictors of postnatal feeding skills. Biometric measures of oral, lingual, pharyngeal and laryngeal structures were obtained in fetuses 15-38 weeks gestational age using a four-plane sonographic technique. Accompanying ingestive behaviors were tallied across development. The data from 62 healthy controls were compared to seven cases at risk for postnatal feeding and swallowing dysfunction (Type II Arnold Chiari Malformation, trisomy 18, polyhydramnios, intrauterine growth restriction, Brachmann-de Lange Syndrome). Significant (p<0.001) linear regressions occurred in pharyngeal and lingual growth across gestation while ingestive behavior such as suckling emerged in a sequence of basic to complex movement patterns. Jaw and lip movements progressed from simple mouth opening to repetitive open-close movements important for postnatal suckling. Lingual movements increased in complexity from simple forward thrusting and cupping to anterior-posterior motions necessary for successful suckling at term. Laryngeal movements varied from shallow flutter-like movements along the lumen to more complex and complete adduction-abduction patterns. Fetal swallowing primarily occurred in the presence of concomitant oral-facial stimulatory activity. Significant variations (p<0.01) in the form and function of the ingestive system occurred in comparisons of gestational age-matched controls to at-risk cases. We postulate that prenatal developmental indices of emerging aerodigestive skills may guide postnatal decisions for feeding readiness and, ultimately, advance the care of the premature, medically fragile neonate.