surgery | Ear, Nose & Throat Blog

Ear development

The ear is a fascinating and complex appendage and organ. Formation is from structures called branchial arches. Branchial (from Greek branchia gills) arches are composed of endoderm on the internal aspect, by clefts composed of ectoderm on the external side with the central mesoderm containing the muscle, cartilage, vessels and nerves that will ultimately supply and establish the surrounding anatomic structures. Molecular signaling from the ectoderm leads the mesenchyme from the mesodermal (central) layer to eventually, if it works out as planned, to obliterate the clefts and and pouches. If clefts persist, they are given names, such as Type I branchial cleft cyst. When this signaling goes wrong, there are different degrees of anomalies, from absence of specific auricle components to microtia or even anotia if there is complete failure.

The ear begins to form the otic placode and vestibulocochlear ganglia at 3 weeks of gestation. The external canal then develops from the first branchial cleft at 4 weeks. By 28 weeks there is a fully open external canal. Failure to canalize can result in membranous or bony stenosis or atresia (from Latin a = no and Greek trēsisperforation, from tetrainein to pierce). Development of the auricle (external ear) begins at 5 weeks gestation with development of the auricular hillocks numbered from 1 through 6, derived from the first (mandibular) and second (hyoid) branchial arches. So the inner ear has already formed when the external ear begins.

The ear develops in a predictable manner, with various alterations in development resulting in predictable deformities when the process is interrupted. Knowledge of auricular development as well as normal external anatomy allows for precise evaluation of the ear and assists in selecting appropriate reconstructive techniques to optimize the complex 3-dimensional anatomical outcomes.

If you have a ear question, please do not hesitate to call me for an appointment. Office number is 989-839-6201, fax is 989-839-6202. Providers can page me through the Midland hospital operator. Patients can reach me by way of the patient portal.

Let me know how I can be of help to you.

Philip Harris, MD FARS
Ear Nose Throat and Cancer of the Head and Neck
Serving Gladwin, Clare, Midland and Alpena
Call for appointment and ask to see Dr. Harris

What is primary hyperparathyroidism?
Primary hyperparathyroidism is a common endocrine disorder that occurs most often as a result of a sporadically occurring single parathyroid adenoma (>85%) and less often due to parathyroid hyperplasia involving all four glands. The only cure is surgical removal of the offending gland(s).

How is primary hyperparathyroidism treated?

Diagnostic techniques and surgical management protocols for parathyroid disease have under-gone a paradigm shift over the last 10-20 years, with a focus on less invasive surgery and greater dependence on technology for preoperative localization, facilitation of less invasive sur-gery, and intraoperative confirmation of removal of correct tissue to resolve the disease process. The transition from traditional, bilateral, 4 gland exploration (four gland exploration or FGE) to directed and minimal dissection single gland removal when supported by high-quality preoperative imaging (directed exploration or DE), has been shown to produce comparable suc-cess (cure) rates and complication rates.

A common pursuit in today’s parathyroid surgical care is the use of rapid intra-operative para-thyroid assay. Of patients with preoperative localization and directed excision, the preoperative studies most predictive of cure are Sestamibi parathyroid scans. Intraoperative parathyroid hormone rapid assay is not associated with a higher cure rate interestingly and does add signifi-cant time to the procedure. Most patients with persistent high parathyroid hormone levels after parathyroid surgery are found to have had associated vitamin D deficiency.

What should you do to work-up a patient you believe has hyperparathyroidism?

Analysis of techniques that predict a surgical cure allowe the development of a best practices algorithm that includes the following: 1. Obtain 2 preoperative localization studies, including an ultrasound; 2. Obtain preoperative vitamin D levels and supplement as indicated; and 3. Reserve intraoperative parathyroid hormone assay only for those patients who do NOT have 2 cor-roborating localization studies.

The management of parathyroid disease can be complex. If you have any questions regarding this or other area of ear, nose, throat, head and neck cancer, sleep surgery, thyroid and parathy-roid, please do not hesitate to call. ENT is trained in 7 core areas over a 5 year residency after medical school: allergy, facial plastic and reconstructive surgery, head and neck, laryngology, otology, pediatric otolaryngology, and rhinology. We are the only surgical specialty dedicated solely to this area.

Philip Harris, M.D. FACS
MidMichigan Physicians Group
Midland / Gladwin / Bay City
Phone (989) 839-6201
www.midmichigan.org/mpg

Tag Archives: surgery

Ear Development

Hyperparathyroidism