THYROID SURGERY

There are three major salivary glands parotid gland, submandibular gland and sublingual gland. Submandibular gland is the second largest salivary gland among the major salivary gland. Anatomically, located in submandibular triangle of neck. The gland is divided into two lobes depending on its relation to mylohyoid muscle, superficial lying superficial to muscle and deep lying deep to muscle. Two lobes are continuous with each other, forming ‘U’ shaped around the posterior of mylohyoid muscle. It lies partly below mandible and partly in submandibular triangle. The submandibular gland duct is also known as Wharton’s duct, exits the gland from deep lobe, passing through the floor of mouth and opening in sublingual region. Function of submandibular gland include lubrication and enzymatic degradation of food substances and production of hormones. Saliva is produced in glandular subunit. The saliva secreted by submandibular glands account for 70% of salivary volume. The saliva secreted by the submandibular glands is a bit thicker than that produced by other salivary glands, and can, as a result, sometimes form little stones in the salivary glands and their ducts. When submandibular gland is affected there is swelling in submandibular region. It may be associated with pain, fever or purulent discharge into the mouth. The swelling of submadibular gland can be due to Bacterial infection which can be treated with antibiotics and analgesics. Stones (most commonly present with swelling of gland due to accumulation of crystallized saliva deposits) lodged in Wharton’s duct or is large or is lodged far back in duct or in gland itself are treated by excision of gland. Malignancies of submandibular glands can be treated by surgical excision of gland.

Parotid gland is largest salivary gland. It situated below external auditory meatus and in front of temperomandibular joint. It produces saliva which keeps the oral cavity moist. Parotid gland disease can be due to infection, tumor or obstruction to parotid duct. Infection can due to viral (mumps) or bacterial (acute or chronic parotitis) and obstruction to parotid duct can be due to stone, stricture or stenoses. They usually present with swelling in preauricular region which may increase or decrease in size after food intake, fever, pain. Treatment includes antibiotic, pain killers or anti-inflammatory drugs. In case of It can be treated with antibiotics, analgesics & anti-inflammatory drugs. Chronic parotitis can also be due to stone, stricture, or stenosis which can be treated with helpof sialoendoscopy by removal of stone and dialatation of stricture. It can be diagnosed withultrasonography, sometimes computed tomography or magnetic resonance sialography maybe required. Parotid tumours can be present with painless parotid swelling which can be treated with surgery like complete or partial removal of gland. Diagnosis is confirmed by Ultrasonography, or Computed tomography scan. Sometimes surgery can lead to complication like facial weakness.

Head and neck cancers are common nowdays due increased consumption of tobacco and its related products. Alcohol, human papilloma virus and radition exposure also increases risk of cancer. Mainly includes squamous cell carcinoma basal cell carcinoma, nasopharyngeal carcinoma, sinonasal and salivary carcinoma, thyroid cancer, laryangeal cancer. Most common among them is squmous cell carcinoma. Diagnosis of cancer made with the help of clinical examination, biopsy, fnac and also with the help of radiological tools like USG, CT SCAN, MRI, PET SCAN etc. Prevention is better than cure in cancer so awareness of tobacco, ban on tobacco product play very important role in cancer prevention. In treatment modalities of head and neck cancer divided into following Surgery - different modalities of surgeries available accordindg to type of cancer, involvement of area of head and neck, involvement of lymph nodes. Chemotherapy - common drugs used in chemotherapy are cisplatin, 5 fluro uracil, gemcitabine. they are given in cyclical manners.(weekly) Radiation-may be given along with chemotherapy. Newer modalities include monoclonal antibodies(cetuximab), insulin like growth factor type 1 receptor inhibitor(figitumumab). Combined approach may be used surgery along with chemoradition.

Sialendoscopy is minimal invasive procedure in obstructive salivary gland diseases. Sialoendoscopy is the procedure in which endoscope is passed through the ductal system of salivary gland i.e. parotid or submandibular gland to visualize their lumen & pathologies like stone, stricture or stenoses. It is complementary to diagnostic techniques such as plain radiography, ultrasonography, computed tomography (CT), magnetic resonance sialography, and conventional sialography, all of which are traditional, time-tested methods for evaluating the salivary ductal system. It can be diagnostic or therapeutic depending on type obstruction. Diagnostic include suspicion of obstructive pathology. Therapeutic include removal stones, dialatation of stricture. In case of adults the procedure can be performed under local anaesthesia, but in children it may require general anaesthesia. The only contraindication for sialendoscopy is acute sialadenitis. Although this condition is not an absolute contraindication, it makes sialendoscopy problematic because an inflamed ductal system is more difficult to dilate. In addition, use of the rigid dilator system, a semirigid endoscope, or both during an acute episode of sialadenitis increases the chance of ductal trauma and potentially fosters the spread of infection in the soft tissues of the head and neck.

A technique for examining the esophagus. The viewing instrument, the oesophagoscope, consists of a long, metallic tube fitted with an eyepiece, lenses, and its own fiberoptic light source which illuminates the field of vision. Esophagoscopy is of two types rigid oesophagoscopy and flexible oesophagoscopy. Flexible oesophagoscopy can be performed under local anaesthesia and rigid oesgoscopy is performed under general anaesthesia. The procedure may be a part of an endoscopic examination of the upper airway and digestive tract, known as panendoscopy. Inspection by esophagoscopy is indicated for dysphagia (difficulty inswallowing), by a foreign object lodged inside the esophagus that can be seen and removed by means of the scope. Or, the esophagoscope can be used to obtain a biopsy (tissue sample) of a benign or malignant growth. Risks include perforation, bleeding and infection.

Thyroglossal cyst presents as a cystic midline neck swelling usually affecting young children but can occur at any age. Development of thyroid cartilage starts at foramen caecum, passes through base of tongue & then descends in front, behind or through the hyoid bone to form the thyroid gland. The thyroglossal cyst can occur anywhere in the course of thyroid duct & it may contain the only functioning thyroid tissue in the body. Rarely carcinoma may develop in the cyst. It’s size increases with upper respiratory tract infection. Sometimes it may presents as a draining sinus if it has burst due to infection or has been surgically drained. It moves with protrusion of tongue due to it’s attachment to base of tongue. Complete surgical excision, includes excision of body of hyoid bone and tongue tissue around the tract in the suprahyoid region. Simple excision of cyst without removal of its tract leads to recurrence.