Since the introduction of Functional endoscopic surgery inferior meatal antrostomy as a procedure has taken a back seat due to the apprehension that it could tamper with the normal mucociliary clearance mechanism. Infact studies performed in 1980's reported that if inferior meatal antrostomy is created the mucous bridges across the antrostomy and travels towards the natural ostium of the maxillary sinus. This can utmost be considered to be only partially true. Current studies have demonstrated that drainage of mucous does occur via the opening created in the inferior meatus.
Current indications for inferior meatal antrostomy:
Patients with chronic sinusitis not responding to FESS
Patients in whom mucociliary clearance is already affected due to cystic fibrosis / Young's syndrome. These patients usually benefit from inferior meatal antrostomy
Mycetoma present in the maxillary sinus cavity
To visualize the difficult to see areas inside maxillary sinus cavity
When regular post op surveillance is needed
Endoscopic inferior meatal antrostomy:
Nasal endoscope is a very useful tool for otolaryngologist. By using this tool the whole procedure can be performed under direct visualization. This procedure can be performed under both LA / GA.
Nasal mucosa is decongested by using pledgets soaked in 4% xylocaine mixed with 1 in 10,000 adrenaline. The pledget should be squeezed dry before insertion. This is done to avoid xylocaine overdosage. Pledgets should be placed in inferior meatus, floor of the nasal cavity, and middle meatus. If general anesthesia is used throat pack should be given to prevent aspiration.
2% xylocaine with `1 in 100,000 units adrenaline is used to infiltrate the inferior turbinate and the corresponding portion of nasal septum. 0 degree nasal endoscope is used for purposes of visualization. A Freer's elevator is inserted into the inferior meatus and the inferior turbinate is up fractured so that it lies perpendicular to the floor of the nasal cavity. This procedure is a must for adequate visualization of the inferior meatal area. The location of Hasner's valve (lower end of nasolacrimal duct) is identified at the junction of anterior third and middle third of the lateral nasal wall. A 90 degree angled J curette is ideal to perform antrostomy. The lateral nasal wall is perforated with J curette about 1 cm posterior to Hasner's valve. The opening is then enlarged with the help of back biting forceps. Now insertion of a 30 degree nasal endoscope will help in better visualization of the interior of maxillary sinus cavity.
Fractures involving nasal bones are common. Manipulating simple fractures involving nasal bones using mallet and champagne cork was reported in a private communication by M ROLLIN, N DE ZOYSA, G MOCHLOULIS of UK.
As for any other nasal surgical procedure the patient is evaluated. This procedure can be performed either under local anesthesia / general anesthesia. The champagne cork is enclosed in a sterile glove finger and tied.
The patient is placed in supine position and the head is stabilized. The champagne cork is placed over the skin overlying the deviated nasal pyramid. Disimpaction of fractured nasal bones is achieved by a firm tap of the cork with a mallet. The rounded end of the cork is used for disimpaction and the flatter end for realignment.
This technique can be used safely to treat simple fractures involving nasal bones with minimal risk of skin trauma. This technique is more suitable in managing late presenting fractures.
Tonsillectomy is a commonly performed surgical procedure these days. With the advent of latest surgical equipments and innovations the risks involved in the surgical procedure has been considerably reduced. One such emerging technological innovation is the introduction of coablation technology which is currently being used to perform tonsillectomy.
Emerging technology – Current expectations:
Technological innovations in any surgical procedure should focus on the following parameters:
Bloodless surgical field
Reduction in the surgical time
Reduced post operative pain
Improved healing rates
This is also known as “Controlled ablation” / “Cold ablation”. This technology uses bipolar high frequency electrical energy to exite the electrolytes in a conductive medium. This excitation creates a plasma field which is higly focussed. The ions present in the plasma field are highly energized and this energy is sufficient to break organic molecular bonds found in the living tissue. This energy dissolves soft tissue at relatively low temperatures, while preserving the integrity of surrounding tissue. Sodium chloride solution is commonly used as a conducting medium in coablation surgical procedures.
Advantages of coablation:
It operates at relatively cool temperatures (40 – 70 degrees centigrade)
Its cutting effect is very precise with very minimal effect on the surrounding tissue
The plasma field which is generated by this equipment is about 100 – 150 microns thick. This is the reason for its precision
This is the technology involved in coablation surgical procedures. Plasma field is defined as a collection of charged particles (equal amounts of positive and negative ions). Plasma field resembles gas physically in some respects, but show significant differences as well. Plasma field is a good conductor of electricity and is affected by the presence of magnetic field, where as it is not so with gases.
Crudely put plasma is a state of matter in which many electrons are free and unbound and move independently. Coablation technology utilizes this phenomenon by generating an electrical field between two small electrodes. This electrical field when made to pass through a medium like normal saline which conducts it rather well, the sodium and chloride molecules become energized and separate from the solution. These sodium and chloride ions are responsible for the formation of plama field.
The wand used in coablation surgical procedures has channels for suction and irrigation. Normal saline should flow through irrigation channel and central suction should be connected to the suction channel.
Below you will be seeing the video of coablation tonsillectomy:
Deep petrosal nerve (post ganglionic sympathetic fibers)
Ascending sphenoidal branch from otic ganglion
Vidian nerve is formed at the junction of greater petrosal and deep petrosal nerves. This area is located in the cartilagenous substance which fills the foramen lacerum. From this area it passes forward through the pterygoid canal accompanied by artery of pterygoid canal. It is here the ascending branch from the otic ganglion joins this nerve.
The vidian nerve exits its bony canal in the pterygopalatine fossa where it joins the pterygopalatine ganglion.
It is through this canal the vidian nerve passes. This is a short bony tunnel seen close to the floor of sphenoid sinus. This canal transmits the vidian nerve and vidian vessels from the foramen lacerum to the pterygopalatine fossa.
According to CT scan findings the vidian canal is classified into:
Type I: The vidian canal lies completely within the floor of sphenoid sinus
Type II: In this type the vidian canal partially protrudes into the floor of sphenoid sinus
Type III: Here the vidian canal is competely embedded in the body of sphenoid bone
Study of these anatomical differences of vidian canal in relation to the floor of sphenoid sinus helps in deciding the surgical approach to the nerve.
CT images showing the anatomical types of vidian canal and their relationship to the floor of sphenoid sinus
Oral candidiasis is a very common fungal infection involving the oral cavity mucosa. These infections are caused by saprophytic fungi belonging to the genus candida. Common organisms involved in oral candidiasis include:
Among these organism candida albicans has been implicated as the common causative organism in oral candidiasis. Candida albicans is dimorphic in nature, capable of existing in two forms i.e yeast and hyphal forms. The hyphal form is associated with oral candidiasis. Studies have shown that candida albicans can exist in the oral cavity as normal commensal.
Predisposing factors causing oral candidiasis:
Poorly controlled diabetes mellitus
In HIV positive patients with CD 4 count less than 200/microlitre
Patients with xerostomia – Use of medications in the elderly are the common cause of xerostomia. Medications known to cause xerostomia include: antidepressants, diuretics and drugs with anticholinergic effects.
Use of broad spectrum antibiotics that could alter the normal gut flora.
Burning mouth syndrome is defined as an idiopathic condition involving the mucosal lining of oral cavity causing excess deep burning pain in the absence of identifiable cause lasting atleast for a period of 6 months. This condition was first described by Fox in 1935.
Glossodynia, Glossopyrosis, Oral dysesthesia, Stomatodynia & Sore tongue. Among these terms Glossodynia is favoured by ICD (International Classification of Diseases).
It affects females 7 times more commonly than males. Studies have shown about 90% of sufferers are perimenopausal women.
Common sites involved:
Buccal / Labial mucosa
Floor of mouth
a. Dryness of mouth – This is purely a subjective sensation not backed by real time reduction in the amount of saliva secreted. Hence this sensation could mean altered sensation to be the cause rather than hyposalivation.
My effort to solve previous years question papers of the Tamilnadu Dr MGR Medical University continues, I have uploaded the MS ENT March 2010 Basic sciences question paper with solutions. You can get it from http://www.drtbalu.com/pgbs_mar10.html