Can the presence of Biofilms be identified under routine H&E staining?

Introduction:
Centers for disease control and prevention estimate that about 65% of human bacterial infectious processes involve biofilms. Biofilm is a group of bacteria seen over surface epithelium like mucous membrane, enclosed within a matrix of extracellular polysaccharide material. The presence of this biofilm has been implicated in the following chronic infections:

1. Chronic rhinosinusitis
2. Chronic bronchitis
3. Atrophic rhinitis
4. Lung infections following prolonged intubation
5. Urinary catheter related infections
6. How biofilms protect the bacteria from host defenses?
   
   
   
   
   
   Biofilm contains multiple types of bacteria. Bacteria from biofilms are difficult to culture & hence difficult to identify. These multiple organisms coexist with each other conferring drug resistance. Antibiotics don't penetrate biofilms in adequate concentrations thus the organisms within are well entrenched and protected. These biofilms surround the microbes with extracellular polymeric substance which constitute a physical non cellular barrier against host defense mechanisms.
   
   
   Staphylococcus and pseudomonas organisms have been implicated in chronic sinonasal disease associated biofilms.
   
   
   How to identify Biofilms?
   
   
   Biofilms have been identified by scanning electron microscopy. Recently Fluorescence insitu hybridization techniques have been used to identify biofilms (FISH technique).
   
   
   Christian J. Hochstim in his original work has shown that the presence of Biofilms can be identified with reasonable degree of accuracy using H & E stains.
   
   
   Histologically under H & E staining, biofilms appear as clusters of basophilic bacteria and host cells entrapped in a layer of extracellular polymeric substance.
   
   
   It is really worthwhile looking for the presence of biofilms in all mucosal specimen sent for biopsy.
    
   
   
   
   
   
   
   
    
   
    
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   

 

Nasal stents are they really useful ?

Introduction:

Formation of synechiae constitute one of the common complications following ESS. Conservative estimates place about 10 % of all patients who have undergone ESS as prone for synechiae. Dissection in the frontal sinus area is more prone for synechiae formation because of the difficult access. Dissection in this area is troublesome due to the difficult angle involved. True cutting instruments which cause little tissue damage have difficulty in reaching this area. Using powered shavers and debriders in this area has also not managed to reduce the risk of synechiae. Stents have been used with varying degree of success in preventing postop complications following ESS.

Functions of Stents following ESS:

1.The primary function of stent is to separate two edges of raw wound thus preventing the formation of fibrous band / synechiae. This is classically seen when there is lateralization of middle turbinate following ESS. Lateralization of middle turbinate can potentially obstruct middle meatus drainage. This can effectively be prevented by placing a stent between the middle turbinate and the lateral nasal wall.
2.Stents can potentially take up space which would otherwise be occupied by mucous/ clot. Presence of clot can lead to epithelial migration and synechiae formation.
3.Patients in whom stents have been placed have very little crust formation, hence frequent wound debridement is not needed.
4.Stents also serve as occlusal dressing facilitating better & faster wound healing. Occlusal dressings have known to reduce tissue necrosis.

Types of nasal stents:

1.Middle meatal stent
2.Frontal sinus stent
3.Drug containing stents

Middle meatal stents:

Role of middle meatal stents include:

1.Decrease synechiae formation
2.To prevent lateralization of middle turbinate
3.Since it fills up the ethmoid sinuses it effectively prevents clots, mucous or fibrin.

Stents of middle meatus is also known as spacers. Common spacers of middle meatus are made of glove fingers filled with polyvinyl acetyl sponge which are sutured together and tied with silk. Since this spacer is smooth it does not adhere to the surrounding tissue, thus serves as an occlusive dressing.

Foam made of biodegradable synthetic material like polyurethane can also be used to stent the middle meatus after surgery. This material is suitable for patients who does not tolerate other types of middle meatal stents.

               Image showing Freemann stent




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Torus palatinus excision

Introduction:

The word “tori” is derived from the latin word torus which means “to stand out” / “lump”.


Synonyms: Exostosis of oral cavity, Buccal exostosis.


Definition:


Torus palatinus is a sessile nodule of bone occuring commonly in midline of hard palate. It can also occur over the lingual surface of the maxilla (torus mandibularis). Torus mandibularis is a bony protruberance located on the lingual aspect of the mandible (commonly between the canine and premolar areas). These are bony masses, begining their development during early teens and gradually progresses to adult hood. These masses are slow growing and painless.


These masses are usually self limiting, rarely they may cause periodontal diseases. Periodontal disease is usually caused by the mass forcing food towards the teeth while being chewed instead of away from it. Too large torus may interfere with dentures.


Etiology:


1.Masticatory hyperfunction
2.Genetic factors (common in females)
3.Environmental factors
4.Multifactorial


Age of occurrence:


It is very rare during the first decade of life. Its increase in size occur during the second and third decades of life. According to Bruce etal the average age of presentation of tori is 34. Since there is very little literature available on this subject very little knowledge regarding age of occurrence is available.


Rate of growth:


The rate of growth of these bony masses is very slow and gradual. Studies have shown that maximum increase in size occurs during the second and third decades of life.

Role of imaging:


CT scan is virtually diagnostic.

Classification:

Oral exostosis was first classified by Haugen. He classified oral cavity exostosis according to their sizes as small, medium and large.

1. Less than 2 mm in their largest diameter – small
2. 2 – 4 mm in their largest diameter – medium
3. More than 4 mm in their largest diameter

According to Haugen majority of oral cavity exostosis belonged to the small and medium categories.

Reichart in his modification of Haugen's classification suggested few changes:

Grade I – Tori up to 3 mm in their largest dimension

Grade II – Tori up to 6 mm in their largest dimension

Grade III – Tori above 6 mm belong to this group

Shapes:

Torus palatinus occur in varying shapes. It can be flat, nodular, lobular or spindle shaped. Small tori are invariable nodular and they are the most common variety encountered. Lobular shapes are pretty rare.

Indications for surgical removal:

1. The mucosa over torus is ulcerated
2. When it interferes with placement of dentures
3. When there is associated periodontal disorder
4. Where torus can be used as graft material
5. Phonatory disturbances
6. Sensitivity of the overlying mucosal layer
7. Disturbances involving masticatory apparatus
8. Esthetic reasons

Surgical removal:

Torus palatinus can be removed either under local / general anesthesia. If the surgery is tobe performed under local anesthesia the following nerves should be anesthetised using 2 % xylocaine mixed with 1 in 100,000 units adrenaline.

1. Nasopalatine nerve should be anesthetised as it exits through the anterior palatine foramen
2. Anterior palatine nerves should be anesthetised through posterior palatine foramen
3. Anesthetic solution should also be infiltrated over the mass to detach the oral mucosa from the mass

To surgically remove torus mandibularis infiltration anesthesia is used over the mass. Nerve block anesthesia blocking inferior alveolar, mental and lingual nerves can also be used.

Incision:

To remove torus palatinus a double Y incision is preferred. This incision prevents damage to the nasopalatine and anterior palatine blocks of the hard palate. The incision should involve the full thickness of the muco periosteal lining.

Surgery to remove torus mandibularis involve incision over the mandibular ridge. If the incision is made above the torus it provides a good operating field. In rare cases scalloped inter dental incisons can be used.

Fissure burr is used to remove the bony torus. After removal of torus the flap could be found to be redundant and the same may also be trimmed. The flaps may be sutured back in place using absorbable suture material.

Surgical complications of torus palatinus:

1. Perforation into the nasal cavity
2. Secondary anesthesia due to damage to palatine nerve
3. Palatine artery hemorrhage
4. Laceration of palatine mucosa
5. Fracture of palatine bone

Surgical complications of torus mandibularis:

1. Mandibular fracture
2. Devitalisation of teeth
3. Injury to salivary ducts
4. Injury to lingual nerve
5. Flap laceration

Post op complications:

1. Hematoma
2. Wound infection
3. Flap necrosis

 

Prosper Meniere an apostle of humility

Prosper Meniere:

Prosper Meniere described clearly the symptoms of Meniere's disease. Even now the description of Meniere's of this disorder holds good. Very little has been added to the description of Meniere's disease.

Prosper Meniere was born in Angers a French town in 1799. He underwent basic education at Lycee. Later he joined the university of Angers. He completed his medical studies at the Hotel-Dieu in Paris which was one of the most prestigious hospitals of Europe those days. He received gold medal for excellence in medicine in 1826. He received his doctorate in medicine in 1828.

He was really popular with the ruling elite. He attended to Duchess Caroline Louise, the widow of the second son of Charles X who was pregnant while imprisoned at Blaye. His popularity with the ruling elite alienated him from main stream academic medicine.

In 1835 epidemic of cholera swept over Europe. Meniere organized regional health care against cholera epidemic. He introduced the concept of barrier nursing while treating these patients. He was awarded the Chevalier of the Legion d'Honneur for this work. During this very period juniors superseded him to professorial chair at the Hotel – Dieu.

1838 happened to be a turning point year in the life of Meniere. It was during this year that Jean Marc Gespard (one of the fathers of otology) died while serving as director of the Institute of Deaf – Mutes in Paris. Meniere who had no formal otological training was appointed to the post. His marriage to the daughter of Becqauerel, an influential member of the Institute of Deaf – Mutes in Paris helped his cause. From now on he dedicated the rest of his life to the care of deaf mutes.

His greatest contribution to medical science came in 1861. It was during this year he presented a paper at the Imperial Academy of Medicine in Paris. In that paper he questioned the then existing theory that vertigo was a form of cerebral apoplexy or epilepsy. He argued in favor of inner ear dynamics. This paper was heavily criticized those days. This paper was based on some astute observations made by him while treating deaf patients who had associated giddiness. He also heavily borrowed from the work of Pierre Flourence who proved by his methodical dissection of pigeon's labyrinth that ablation of various portions of labyrinth caused loss of balance in these birds. He also precisely recognised that vertigo of central origin was not associated with hearing loss. He also observed that patients with aural vertigo did not lose consciousness during attacks of vertigo.

He died at the ripe age of 62 following an attack of pneumonia in 1862. The triad of tinnitus, vertigo and deafness became recognized as “Maladie de Meniere”. This term was coined by Charcot in 1874.

Menier's was a man of great humility. One of his famous quotes runs like this:

“I am certain that the best works have been burned, that

the sweetest verses have never been printed . . . whereas

the shameless, the impertinent, the pre-eminent show off

with insolence in the sun of publicity without any right to

do so.”

Eagle's syndrome

Introduction:
The styloid process shows lot of variations in its length. In majority of patients it is about 20 – 30 mm long. Technically speaking when the length of styloid process exceeds 30 mm then it is considered to be elongated. The clinical signs and symptoms associated with elongated styloid process was first described by Eagle in 1937. Later this condition became known as Eagle's syndrome / Elongated styoid process. The signs and symptoms of elongated styloid process are pretty vague and often at best misleading. These patients usually go medical shopping visiting neurologists, dental surgeons, psychiatrists and surgeons. The diagnosis of this condition requires awareness and vigilance. This condition can be confirmed by palpating the tonsillar fossa, infiltration of local anesthetic agents and imaging studies.

History:

Historically the ossification of stylohyoid apparatus can be divided into three periods.
This division is purely for better understanding.
Era of anatomists: Anatomists belonging to 17th century described ossification of stylohyoid apparatus they encountered during dissection as normal variants as they were not privy to the clinical details and patient history.
Era of diagnostic radiologists: This period includes the early 20th century. Due to advances in radiological anatomy, radiologists were able to identify ossification of stylohyoid apparatus and correlate this condition with that of the symptoms expressed by the patient. Eagle under whom this syndrome is named belonged to this era.
Era of panoromic radiology: This period includes the mid 20th century. Routine study of panoromic radiographs by dental surgeons threw up more such cases of ossification of the stylohyoid apparatus.

Classification:

Gossman's classification of types of elongated styoid processes: Gossman studies about 4000 patients with elongated styoid process and classified it into three types.

1.Elongated
2.Crooked
3.Segmented
4.Very elongated

Correll's classification of elongated styloid process:

Type I: Elongated styloid process
Type II: Pseudoarticulated styloid process
Type III: Segmental styloid process

Symptoms:
Common symptoms associated with elongated styloid process include:

1.Vague pain in the neck
2.Foreign body sensation in the throat
3.Pain in the throat
4.Painful swallowing
5.Pain while changing head position
6.Pain in the ear
7.Pain over temporomandibular joint
8.Pain radiating to upper limb

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Bullard laryngoscope

Introduction:

Bullard laryngoscope is a rigid fiberoptic laryngoscope which aids in visualization of larynx and intubation of trachea. Hence it is a very useful tool in the management of difficult airway. It uses fiberoptic technology and mirrors to look around the nook and corners of larynx.

Advantages of Bullard laryngoscope:

1. It is very useful during difficult intubation
2. Since it is designed to be inserted with the patient's head and neck in neutral position it can be used safely in patients with unstable cervical spine
3. It can be used in patients with mouth opening of just 6 mm
4. It can also be used for nasal intubation procedures
5. It can also be safely used in paediatric population also since it is available in adult and pediatric sizes

Situations tailor made for the use of Bullard laryngoscope include:

1. Patients with anteriorly placed larynx
2. Patients with unstable cervical spine fracture
3. Patients with upper body burns / trauma
4. Patients with temporomandibular joint immobility
5. Patients with micrognathia

Bullard laryngoscope is desgined in such a way that its blade is anatomically curved. At the proximal end an eye piece is provided. It is also provided with a fibreoptic power source attachments. It has two ports i.e. One for oxygenation / instilling medicines / suctioning and the other one for attachment of endotracheal tube stylet. Illumination is provided by fiberoptic light source.

The choice of the size of Bullard scope (adult / pediatric) is made taking into account the height of the patient and the minimal size of endotracheal tube that can be fitted into the stylet.

If the patient is 5 feet and less – pediatric size is preferred

If the patient is more than 5 feet but less than 6 – adult size preferred

If the patient is more than 6 feet tall – adult size with tip extender is used

Procedure:

1. If adult Bullard laryngoscope is used the tip / blade extender is securely snapped into the laryngoscope blade.
2. Select appropriately sized endotracheal tube. The endotracheal tube connector is removed temporarily and lubricant is applied over it.
3. The stylet is inserted into the endotracheal tube until it protrudes out of the endotracheal tube opening
4. When looking through the optical eyepiece only the stylet should be seen and not the tip of the endotracheal tube
5. Lubricant should also be applied to the Bullard blade also to facilitate easy insertion. Care should be taken to use only water based lubricants
6. Attach fiberoptic light source to the laryngoscope

Oral intubation:

1. Induction drugs are adminsitered to the patient as for regular intubation
2. Patient should be in neutral position
3. Place yourself as if you are performing direct laryngoscopy, the axis of the scope should be parallel to patient's axis
4. The scope is introduced between the teeth into the pharynx and is inserted as close to the midline as possible. The endotracheal tube should be held firmly in the nook of Bullard's laryngoscope while the whole assembly is being advanced.
5. When epiglottis is visualized, the handle of the Bullard laryngoscope is elevated straight up, the tip of the laryngoscope could be then seen retracting the epiglottis out of the way facilitating direct visualization of laryngeal inlet
6. The endotracheal tube is advanced over the stylet, and under direct vision is pushed into the trachea between the relaxed vocal cords
7. The stylet is detached and the scope is gently removed after ascertaining that the endotracheal tube is in place
   
   
   
   
   
   
   
   

Laryngeal mask airway

Laryngeal mask was developed in 1980's, and recently is being used extensively in emergency medicine. It affords excellent ventilation without going through the normal intubation process and visualization of laryngeal inlet. It should be considered as a supraglottic airway management device. It can be introduced even by an emergency technician with training during emergency situations. Visualization of glottis is not essential for introduction of laryngeal mask airway.
Laryngeal mask was first developed by a British Anesthesiologist by name Archie Brain in 1980. Brain considered laryngeal mask airway as a physical junction between artificial and anatomic airway. According to Brain the major advantages of Laryngeal mask airway are:

1. It reduced dead space
2. Allowed normal functioning of protective reflex
3. It was highly reliable than face mask ventilation
4. It is really helpful in managing difficult airway
5. It is very useful during failed endotracheal tube intubation when the abdomen is full of inflated air. In these patients the danger of aspiration is very real. Insertion of laryngeal mask airway will not only secure the airway in these patients but also prevent aspiration of stomach contents.
6. It can be introduced even without paralyzing the patient



Development of laryngeal mask:

Brain designed laryngeal mask after careful study of plaster casts of cadaver airway. He also conceived that by inflating an elliptical cuff at the level of hypopharynx an airtight seal could be achieved. This method required reliable avoidance of down-folding of epiglottis within the mask orifice during insertion.
Laryngeal mask became commercially available in Britain in 1988, and US adopted it since 1992.

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Endoscopic cordectomy

Introduction:

Vocal cord malignancies can be identified at a very early stage because the primary symptom hoarseness of voice prompts the patient to seek medical attention during the early stages of lesion. With the increasing awareness of glottic cancers patients even seek attention during the carcinoma in situ stage itself. Early identification of the problem will help us to resort to conservative surgical procedures with curative intent. Accuracy of diagnosis is further enhanced by the common availability of video laryngoscopes even in the out patient settings commonly. In fact video laryngoscopy has become an out patient procedure, and it picks up vocal cord lesions at a very early stage itself.

Aims of endoscopic cordectomy:

1. Eradication of malignant process
2. Preservation of natural function
3. Can be used to stage the lesion

Advantages of endoscopic cordectomy:

1. Easily performed procedure
2. Relatively inexpensive
3. Preserves voice functions

Indications for endoscopic cordectomy:

1. T1 glottic carcinomas
2. Carcinoma in situ with mobile cord where irradiation is contraindicated

Contraindications:

1. Preoperative stroboscopy will help to rule out deeper tumor extension which is a contraindication for this procedure.
2. Patients with excessive tumor burden are not ideal candidates for endoscopic resection.
3. Patients with cervical spine degenerative disorders
4. Patients with poor mouth opening / retrognathia
5. Patients with short neck because visualisation of larynx is poor

Positioning of the patient:

Cordectomy / vocal cord stripping is performed ideally under general anesthesia. Patient is placed in supine position with head in 'flexion – flexion' position and intubated with laser safe endotracheal tube. Patient is then shifted to 'flexion – extension' position with cervical flexion and atlanto occipital extension. This position known as Boyce position helps in better visualisation of the anterior commissure area. A Klein Sausser suspension laryngoscope is used to visualize the laryngeal inlet and vocal cords. It is fixed in position with a chest piece. This really frees up both the hands of the surgeon. The entire tumor should be visible through the laryngoscope. Either a microscope or an endscope can be used to visualise the tumor.

Subepithelial injection of saline epinephrine solution using a Brunig's syringe or a butter fly needle will help to determine whether the lesion has spread beyond the lamina propria into the deeper structures like the vocal ligament or thyroarytenoid muscle. In addition to its diagnostic utility this fluid infiltration also serves as a potential heat sink if laser is used. It protects the deeper layers from laser burns.

In patients with carcinoma in situ it is sufficient if only the outer epithelial layer alone is removed and the plane of dissection is confined superficial to the lamina propria. Care should be taken not to expose the vocal ligament as it would entail damage to the gelatinous lamina propria. An intact lamina propria is a must for satisfactory voice production.

If pre op CT scan / stroboscopy reveals deeper invasion of tumor then resection should begin with vestibulectomy. Vestibule is vascular hence laser resection will help in minimizing bleeding. Affected vocal cord should also be removed. This is called classic cordectomy procedure.

Surgery in the anterior commissure area is always fraught with the danger of web formation due to exuberant granulation tissue. This can be avoided by stenting that area or applying mitomycin over the area. Application of mitomycin serves dual purpose, not only it is an anti cancer drug it also reduces the degree of fibrosis.

Figure showing growth vocal cord

Blow out fracture of orbit recent management trends

Blow out fracture of orbit is defined as fracture of one or more of its internal walls. This injury is typically caused by blunt trauma to orbit. In pure terms this definition does not involve the orbital rim. If fracture of orbital rim is associated with fractures of one or more of its internal walls then the term complex blow out fracture is used. Even though there is nothing complex about it, this term is used to stress the importance of non involvement of orbital rim in blow out fracture. Blow out fracture is actually a protective mechanism which ensures that sudden build up of intraocular pressure which could be detrimental to vision does not occur following frontal injury to orbit.



History: Blow out fracture of orbit was first described by Lang in early 1900's. The exact description of the fracture and the terminology (blow out fracture) was first coined by Converse and Smith. It was infact Smith who first described inferior rectus entrapment in between the fractured fragments, causing decreased ocular mobility.

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Infantile hemangioma - Role of Propranolol in its management

Introduction
Hemangiomas are common in children. It is seen in 1 in 10 of all children. About 50% of all hemangiomas in children are located in the head and neck area. Majority of them are single lesions which are inconspicuous at birth but undergoes rapid growth throughout the first year of life. Studies have also demonstrated that infantile hemanigomas are more common in premature infants. This has been attributed to the fact that mothers with premature uterine contractions receive tocolytics which are potential vasodilators.

Theories of infantile hemangioma:

1.Infantile hemangiomas have been postulated to originate from placenta – Studies have shown that endothelial cells constituting infantile hemangiomas resemble placental vessels
2.Mutation of endothelial cells
3.Environmental factors have been postulated to stimulate growth of these infantile hemangiomas

Regulators of hemangioma growth:

The topic of regulators involved in the growth and involution of infantile hemangiomas is still in infancy. Histologically infantile hemangiomas is composed of a mixture of clonal endothelial cells, pericytes, dendritic cells and mast cells.

Hemangiomas usually appears within the first few weeks of birth, undergoes rapid increase in size as the infant grows. The increase in size of infantile hemangiomas is much more rapid than that of infant's growth curve. This active proliferative phase is characterized histologically by plump endothelial cells showing evidence of frequent mitosis, increased number of mast cells and multilaminated basement membranes. Studies have demonstrated the involvement of two angiogenetic factors during this phase, they are basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF). This phase of active proliferation is followed by a phase of spontaenous slow involution (possibly due to apoptosis). This phase is characterized histologically by the presence of flat inactive normal looking endothelial cells in a matrix of fibrofatty tissue.

Treatment modalities:

1.Oral steroids
2.Systemic steroids
3.Cyclophosphamide
Among the above three treatment modalities systemic steroids offer the best results, of course with its attendant complications. Intralesional steroid injections have caused significant reduction in the size of these masses.

Use of Propranolol in the management of infantile hemagiomas was noticed by accident when a few children who underwent treatment for their cardiopulmonary conditions with propranolol showed significant reduction in the size of the hemagiomatous lesions. This led to a flurry of activity in the medical world. Propranolol was discovered by Sir James Black. It is a non selective beta blocker which revolutionized cardiac and hypertension management for a long time.


Therapeutic effects of propranolol in hemangioma:

1.Vasoconstriction – The ability of this drug to cause constriction of blood vessels supplying hemangioma tissue will cause significant reduction in its size. The hemangioma also undergoes significant softening in response to propranolol
2.Down regulation of angiogenetic factors like bFGF and VEGF
3.Upregulation of apoptosis of capillary endothelial cells


Dosage:

Propranolol should be administered during the proliferative phase of infantile hemangiomas in doses of 2-3 mg /kg /day divided into 2-4 doses.

Precaution:

The drug should not be discontinued abruptly and should be done in a tapered manner (during the period of 2-3 weeks) to prevent rapid increase in the size of the lesion.

Role of intraoperative imaging in endoscopic skull base surgery

Introduction:
Advances in nasal endoscopic surgery have prompted the surgeon to explore hither to unexplored vistas, like skull base surgery. It has been proved that endoscopic skull base surgery has helped in the reduction of morbidity and mortality of classical craniofacial approaches. Technologically superior endoscopes with wide field of vision, better illumination, camera and monitors have improved the success rate of these surgical procedures. These rigid endoscopes despite their obvious advantages provides only a 2 dimensional view of a complex 3 dimensional space. Image guided surgery was popularized in order to provide a certain degree of 3 dimensional view. Image guided surgery is heavily dependent on preoperative image data collection, resulting in a scenario of non visualization of the anatomic manipulation caused by the surgical procedure. This is where intraop imaging score over conventional image guided surgery because of its real time imaging ability. The operating surgeon will be virtually seeing the imaging of his surgical procedure.

Advantages of intraop imaging:

1.Provides real time images of the surgical field
2.These images can be fed into the image guidance system for better visualization of the surgical field. In other words it gives real time updates for image guided surgery.
3.Intra op imaging may help in performing extensive skull base surgeries using an endoscope.
4.It may be useful in managing complex craniofacial fractures


Equipment specification for intrao op imaging:

1.Equipment for image acquisition
2.Equipment for transferring the acquired image
3.Equipement for viewing and manipulation of acquired images
4.Software necessary to upload these real time images to the navigation system
5.A computer workstation to make all these things possible

Intra op imaging equipment should ideally be:

1.Portable
2.Capable of rapid image acquisition
3.Compatible with already commercially available image guidance systems
4.CT scanner / MRI scanner can be used for intra op imaging. CT scanner is preferrable because of its rapid scanning time, and excellent bone details which it provides.

Role of Cone Beam CT in intra op imaging:

This is slowly replacing conventional in office x-ray machines. It is very useful for rapid diagnosis of sino nasal and otological disorders. This CT machine permits imaging of the structure in question within single rotation. It uses the technique of volumetric tomography. Other major advantages of this imaging modality is reduced time of scanning and reduced exposure of the patient to harmful effects of irradiation. It is also comparatively less expensive than MRI scanners. These devices are highly portable and can be effortlessly wheeled into the operating room.

Image showing portable CT scanner

Three dimensional fluroscopy:

This is the other popular method of intra op imaging. It is highly portable and maneuverable. Patient is placed between the fluroscope and image intensifier. The image acquired is viewed on a portable workstation monitor. Softwares are available for converting the 2 dimensional image data acquired to 3 dimensional ones.

It should always be borne in mind that intra op imaging at the most provides complimentary information to the endoscopic portion of the surgical procedure.

Limitations of intra op imaging:

Are nothing but limitations of Cone Beam CT scanning. Due to technological limitations there is some loss in the quality of soft tissue imaging. Infact fluid / blood within the sinus cavity may be confused with that of residual mass / polyp. Hence intra op imaging should always be interpreted in conjuction with the endoscopic vision.

Sonotubometry and its role in assessing functional integrity of eustachean tube

Introduction:
Sonotubometry is based on the principle that sound when applied to the nasopharyngeal ostium of eustachean tube will be conducted through the eustachean tube into the middle ear when it opens. This concept was first conceived durning the 19th century. It has undergone lot of changes like introduction of better microphones. Politzer should be credited for the introduction of sonotubometry for analysis of eustachean tube function.

Principle:
In principle sonotubometry records changes in sound pressure level in the external auditory meatus when a constant sound source is applied to the nostril. In theory the eustachean tube opening will cause an increase in the sound pressure level of middle ear cavity causing a retrograde conduction of sound from the middle ear to the external canal which is recorded by a sensitive recording device. For this to occur the eustachean tube should open and close normally. By just recording the sound which is transmitted from the nose to the external canal via the eustachean tube it is possible to assess the functional integrity of the eustachean tube.

Diagram showing the placement of microphone in the external canal to record the transmitted sounds.

Advantages of sonotubometry:

1. 
   
   The whole procedure is performed under physiological conditions
2. 
   
   Static pressure is not applied over the external auditory canal
3. 
   
   The whole procedure is independent of the status of ear drum

Pitfalls of sonotubometry device:

1. 
   
   Leakage of sound from the nostrils and external auditory meatus
2. 
   
   Identifying the optimal frequency of test sound that should be used
3. 
   
   Results got corrupted due to the physiological noise of swallowing

These pitfalls were overcome by using inflatable nasal seals that would prevent leakage of sound from the nose and the use of pneumatic valve on the meatal microphone. This pneumatic valve would ensure that the external canal is sealed properly and there is no leakage of sound from it.

Regarding the frequency of test sound that should be used it has been demonstrated that frequencies between 6-8 kHz usually produced the best results. It has also been determined that frequencies of 5 kHz usually could be mistaken to that of physiological noises produced due to the act of swallowing.

Procedure:

The test is usually performed by placing a pneumatic microphone inside the external canal and a nasal sound probe which could generate sound at frequencies ranging from 6-8 kHz. Patient is asked to take about 20ml of liquid and hold it inside the oral cavity. When the sound is projected via nasal probe the patient is asked to swallow the liquid. This act of swallowing will open the normally functioning eustachean tube and is considered to be normal if the sound recorded at the external auditory canal reaches the level of 4dB sound pressure level. The duration of the eustachean tube opening can be calculated as the time difference between the onset of increase in the amplitude of sound and the return to its baseline.

Figure showing the sonotubometric curve. SPL reaches the peak level at the external canal 16 dB at 500 milliseconds. The base of the triangle formed by the curve is the time which eustachean tube is kept open. By looking at this curve eustachean tube functional abnormalities can be identified.

 

 

 

Taste disturbances following tonsillectomy

Introduction:
Tonsillectomy is a commonly performed surgical procedures these days. Even though it has its
own set of complications, disturbance in taste following surgery should be considered rare.
This article tries to dwell into the possible causes of taste disturbance following tonsillectomy.

Tonsillectomy is a commonly performed surgery these days. It is a reasonable safe surgical procedure
of course with its own set of complications. Certain complications like taste disturbance following tonsillectomy
is very rare. Seiichi Tomofuji et all managed to study the incidence of taste disturbance following tonsillectomy.
They devised a questionnaire to be answered by all tonsillectomy patients as given below:

1. Do you have taste disturbance after surgery ? (yes / no)

2. If the answer is yes what taste is blunted ? (sweet, salt, sour, bitter, umami, and all)

3. Do you feel any change in taste after surgery ? (yes / No)

4. If yes what change you feel ?

5. Do you feel thirsty ? (yes / no)

6. Are you able to eat ?

Based on this questionnaire they came to the conclusion that 1% of all tonsillectomy patients
had some disturbance in taste.

Causes of taste disturbances following tonsillectomy:

1. Injury to the lingual branch of glossopharyngeal nerve when the inferior pole of tonsil is snared

2. Due to pressure of mouth gag on the tongue

3. Zinc deficiency due to poor intake after surgery

4. Possible side effects of post op medicines (certain drugs chelate zinc antibiotics and analgesics)


Phantom taste should always be taken into consideration if lingual branch of glossopharyngeal nerve is
damaged on one side only.

Taste disorders include:

a. Hypogeusia

b. Ageusia

c. Dysgeusia

d. Phantogeusia

Patients usually ignore quantitative taste disorders. It is only the qualitative taste disorder like
persistent bitter / metallic taste that troubles a patient.

Postoperative zinc supplements in these patients may be of help. This is actually the consensus of opinion.

Anosmia in elderly

Introduction: Anosmia in geriatric age group is really common. Statistically speaking about 15% of geriatric population are anosmic. Anosmia in geriatric age group has disastrous consequences, including safety hazard. It affects the food preferences and nutritional status of the already compromised population. The absolute odor sensitivity as well as sensitivity to suprathrehold odors decreases in aging population. Loss of smell sensation could be a component of degenerative disorders like Alzeimer's disease and Parkinson's disease which commonly affect elderly age group.
Anosmia in elderly could very well be caused by pathologies involving either the transport of odoriferous molecules to the olfactory cleft or central processing mechanisms.

Applied anatomy & Physiology of smell:
Odors usually reach the olfactory epithelium present in the olfactory cleft orthonasally (anteriorly) via the nose and retronasally via the oropharynx. This retronasal pathway is essential for appreciating flavor of food consumed. In animals this pathway is essential to maintain the vital sense of smell even while feeding since it is very important for their survival. Odorants are appreciated when these molecules bind to the olfactory epithelium found in the roof of the nasal cavity. The most important feature of these olfactory receptor cells is the presence of non motile cilia which are the primary receptors of olfaction. These cilia are endowed with a large number of olfactory receptor proteins to which the odoriferous molecules bind. When these odoriferous molecules bind to the olfactory epithelium the G protein and cyclic AMP pathway is activated causing depolarisation of the olfactory receptor. The signal from the depolarized receptors are carried by the olfactory fibers to the primary olfactory cortex present in the uncus. The function of these receptors are dependent on the composition of mucous blanket which covers them. This mucous blanket is secreted by Bowman's glands and sustentecular cells. The quantity and quality of this mucosal blanket drastically changes in older age group blunting their ability to smell. Since the cilia over olfactory epithelium are nonmotile, the mucosal blanket clearance depends on the normal ciliary motility of the nasal epithelium.

The quality of the mucous blanket over the olfactory epithelium changes

1.During upper respiratory tract infection
2.Cigarette smoking
3.Inhalation of toxic substances
4.Old age

Pattern of airflow in to the nasal cavity plays an important role in olfaction. Studies have shown that major air flow occurs through the floor of the nose, next comes through the middle meatus. Only 10% of the inspired air traverses through the roof of the nasal cavity (olfactory area). It is this superiorly directed air flow that determines the acuity of olfaction. In elderly individuals due to atherosclerotic changes of submucosal vessels the turbinates dont congest and decongest automatically, causing the air flow through the nasal cavity to be laminar in nature. Laminar air flow always occurs through the floor of the nasal cavity depriving the olfactory area's exposure to the inspired air. Hence elderly individuals resort to sniffing in order to perceive smell. Alar muscles of the nose must be acting normally in these persons for eddy currents to develop in the inspired air. Eddy currents ensure atleast a portion of the inspired air travels through the roof of the nasal cavity. In elderly individuals the alar muscles are weak and periodical sniffing acts leaves them really tired and drowned hence they avoid making this consious effort to perceive smell.

The olfactory epithelial layer is endowed with the presence of progenitor cells. These cells on maturation can progressively replace degenerated olfactory receptor cells. The number of these progenitor cells undergoes progressive reduction as the patient ages. Hence the regenerative ability of olfactory epithelium is highly restricted in geriatric age group compounding the problem of anosmia.

Olfactory receptor cells: These are bipolar neurons which are not only constantly exposed to odoriferous molecules but also to the insults heaped upon by viral infections, inflammations, and inhaled toxins. They undergo regular death by a process known as apoptosis. Their population is continuously replaced by the maturing progenitor cell pool. In nasal and sinus disorders the level of enzyme capsase 3 increases to alarming levels. This enzyme stimulates apoptosis (programmed cell death) of the olfactory receptors.
Importance of mucosal blanket over olfactory cleft in maintaining the function of smell:

1.The odoriferous molecules dissolves in the mucosal blanket before they are exposed to the olfactory epithelium
2.The mucosal blanket also clears the odoriferous molecules after they have stimulated the olfactory epithelium
3.The water content of the mucosal blanket plays an important role in maintaining the normal olfactory function. In patients of geriatric age group the hydration of the mucosal blanket is poor and hence there is a diminition in the olfactory function.
4.Exposure to cigarette smoke delays clearance of the mucosal blanket causing diminition of sensation of smell
5.Exposure to heavy metals like manganese (prolonged) causes alteration in the metabolism of the mucosal blanket causing subtle changes in its composition leading on to blunting of sensation of smell. This is the third common cause of olfactory problems in elderly.

Olfactory epithelial changes that occur due to aging:

As the individual grows older the olfactory epithelium gets progressively replaced by respiratory epithelium causing a diminition in the sensation of smell. Studies have shown that significant amount of olfactory epithelium gets replaced by respiratory epithelium by the time a person reaches the age of 70.

Damage to olfactory bulb and neuronal olfactory pathways due to degenerative neurogenic disorders are common in old age group. This is one important cause for blunting of sensation of olfaction in a patient above the age of 80. Alzeimer's disease is the most common degenerative disorder affecting this group of patients. It not only causes dementia in this age group, but also blunts their olfaction. Diminition of olfactory sensation is seen in early stages of Alzeimer's disease.

Appreciation of flavor of food:
This is dependent on retronasal olfaction. This is commonly affected in elderly individuals who use palate covering dentures. This is one of the common cause of loss of flavor of food stuffs seen in geriatric patients. In addition healthy oral cavity is a must for perception of flavors. Dry oral cavity commonly seen in elderly also cause loss of perception of flavor of food.

Triangular uvulopalatal flap

Introduction:

Retropalatal region is the common site of obstruction in most patients with obstructive sleep apnoea syndrome. Uvulopalatopharyngoplasty (UPPP) has been used with reasonable degree of success to treat these patients. Powel etal introduced this procedure of triangular uvulopalatal flap technique to achieve the same result. This procedure has the additional benefit of reducing the width of the soft palate significantly. This procedure has lower morbidity and risk when compared to UPPP.

Procedure:

An incision is made about 1 cm behind the posterior end of hard palate. A triangular flap is created over the palatal mucosa as shown in the figure below. Dissection is performed between the submucosal adipose tissue and the underlying muscular tissue. Triangular shaped posterior pillar mucosa near the base of the uvula is excised. The triangular mucosal strip is carefully dissected and removed exposing the underlying muscle tissue. The uvula is reflected backwards and sutured to the soft palate.

Diagram showing the steps of triangular uvulopalatal flap

Advantages:

1. 
   
   This procedure causes significant widening of retropalatal airway
2. 
   
   Post operative scarring not only stabilized the soft palate it also stiffened it thus preventing its vibration during sleep.
3. 
   
   There is virtually no risk of post operative bleeding, because the deeper muscle layer is not injured.
4. 
   
   Post operative pain is really minimal.
5. 
   
   Since this procedure is purely a mucosal procedure there is no risk of voice change or swallowing difficulties after surgery
6. 
   
   Results of this procedure is more or less comparable to that of UPPP
7. 
   
   Snoring was reduced in 90% of these patients

 

Surgical management of bilateral abductor paralysis of vocal cords

Introduction:
     Bilateral abductor paralysis of vocal cords is a surgical emergency.  If it is noticed on the table extubation can be deferred.  Usually it is identified only during the first few days following surgery.  In these patient management of airway takes precedence over voice management.  Air way should be secured immediately by performing a tracheostomy.  In this article I attempt to discuss the role of various surgical modalities available in managing this problem.

Causes of bilateral abductor paralysis:

1. Surgical trauma (Total thyroidectomy)

2. Malignancies

3. Endotracheal intubation

4. Neurologic disorders

5. Idopathic (mostly viral infections)

6. Metabolic causes: Hypokalemia, Hypocalcemia and diabetes mellitus

Bilateral abductor paralysis of vocal cords following endotracheal intubation is caused by:

1. Dislocation of arytenoid cartilages
2. Anterior displacement of thryoid cartilage in relation to cricoid cartilage causing stretching and damage to the recurrent laryngeal nerve
3. Hyperextension of neck during difficult intubation procedures may cause stretching damage to the vagus nerve
4. Excessive cuff pressure may cause damage to the recurrent laryngeal nerve
5. Introduction of laryngeal mask may also damage the recurrent laryngeal nerve
6. Prolonged intubation may cause damage to the recurrent laryngeal nerves

Surgical causes of bilateral abductor paralysis:

1. Thyroid surgery

2. Parathyroid surgery

3. Esophageal surgery

4. Tracheal surgery

5. Brain stem surgery

Neurological causes of bilateral abductor paralysis:

1. Arnold chiari malformation

2. Meningomyelocele

3. Amyotrophic lateral sclerosis

4. Shy Drager syndrome

5. Hydrocephalus

Presenting features:

Stridor: Need to addressed first (tracheostomy)
Voice changes: Usually are minimal
Swallowing difficulties

Videolaryngoscopic examination: Shows both vocal cords to be in paramedian position.  Cords are not mobile.

Surgical procedures:

1. Posterior cordotomy (unilateral / bilateral).  Aspiration will be a problem if bilateral cordotomy is performed
2. Arytenoidectomy (partial / complete): Endoscopic / external
3. Cordopexy / lateralization of vocal cord

1. In all patients of bilateral abductor paralysis of vocal cords air way management takes precedence over voice. Air way should be secured immediately by performing tracheostomy.
2. Efforts should be made to decannulate the patient as early as possible
3. In patients who have failed the efforts of decannulation, surgical management becomes a necessity.
Posterior cordotomy can be performed in patients with mild / moderate compromise of the airway. This procedure is more conservative, and has very little risk of aspiration.
Posterior cordotomy was first performed by Kashima and Dennis in 1989.
Suspension laryngoscope is used to visualize the larynx.
If laser is available it is better to perform laser cordotomy, because bleeding is minimal when laser is used.
Incision is made over the posterior portion of the true cord, just in front of the vocal process of the arytenoid cartilage.
About 1/3 of the posterior portion of the vocal cord is removed. Care should be taken not to damage the ventricle as it would cause
irreversible damage to the patient's voice.

A novel method of handling Little's area bleeding

Introduction:

Many a time we would have faced problems cauterizing a Little's area bleed. This is basically due to the use of nasal speculum which obscures the field and also keeps one hand occupied. Bray in his " How I do it" describes how he put to use the Mallet spint.

Procedure:

A Mallet splint is a common tool used to treat Mallet (Trigger) finger. This splint is available in different sizes. It can be cut and introduced into the anterior nares. This keeps the nasal cavity open providing a good view of nasal septum area. It also has the advantage of leaving both the surgeon's hand free. The most proximal part of the Mallet splint is cut and shaped into a "U" shaped splint. This splint can be readily inserted into the nasal cavity. Since this splint is made of silastic, its memory holds the nasal cavity open.

Since both the hands of surgeon are free the bleeder can easily be cauterized either by electro or chemical cautery.

Figure showing Mallet splint

 Figure showing modified splint inside anterior nasal cavity

Blow out fracture of orbit endoscopic repair

Introduction:

Blow out fracture is one of the common injuries of orbit. This is commonly caused due to frontal blunt injury to orbit causing fracture of the floor of the orbit. Orbital fat / extraocular muscles may be entrapped within the fracture fragments. Commonly entrapped extraocular muscle is inferior oblique muscle. Usually entrapment of these muscles causes diplopia when the patient attempts to look down. Blow out fracture also creates enophtholmos since prolapse of orbital contents into the maxillary sinus through the fractured floor causes reduction in the volume of orbital contents.

Clinical features of blow out fracture orbit:

1. Orbital swelling immediately

2. Ecchymosis

3. Step deformity of infraorbital rim and crepitus on palpation

4. Entrapment of infraorbital nerve will cause anesthesia over the chin on that side

5. Positive forced duction test - in patients with entrapment of inferior oblique muscle

6. Diplopia on looking down

Management:

Should ideally be performed after reduction of orbital oedema.

Caldwell Luc procedure should be performed. Through the opening in the anterior wall of maxillary sinus the fractured floor of orbit is elevated. The fractured fragments can be held in position by placing plate and screws via a subciliary incision. Two incisions are necessary for successful reduction of blow out fracture conventionally. The first one is the sublabial incision to perform caldwell luc procedure, and the second one is the subciliary incision to stabilize the fractured fragments.

Endoscopic reduction of blow out fracture:

Advent of endoscopes have helped in the management of blow out fracture under vision.
Step 1: A caldwell luc procedure is first performed by creating an opening in the anterior wall of maxilla. An endoscope is introduced through the opening and the fracture is reduced under vision

Step 2: Inferior meatal antrostomy is performed using Miles retrograde gouge.

Step 3: Foley's catheter is introduced into the maxillary antrum through the inferior meatal antrostomy and its bulb is inflated with air. The inflated bulb holds the reduced fractured fragments in position and it should be retained for atleast 6 weeks.

Malignant growth tongue Role of surgery

Introduction:
Malignant lesions involving tongue are very difficult to treat.  This is partly due to the fact that tongue is richly endowed with lymphatics.  Even small lesions can involve regional lymph nodes.  The proximity of this organ to mandible makes irradiation a difficult task.  Mandible responds to irradiation rather poorly causing osteo radionecrosis leading on to troublesome fistula formation after irradiation.  Irradiation of these patients need to be planned carefully and is fraught with irritable side effects like dryness of mouth, halitosis etc.

Clinical details of the patient who was treated with hemiglossectomy:

65 years old female patient - C/O ulcerating mass in the left lateral border of tongue anteriorly - 6 months duration.
H/O Tobacco chewing ++
On examination:
Tongue protrusion and mouth opening were normal.
Slough covered ulcero proliferative mass measuring 3 cms in its largest dimension, could be seen occupying the lateral portion of anterior 1/3 of tongue.  On palpation mass was found to be indurated.  Clinically there was no evidence of Nodal metastasis.  CT scan of neck also showed no evidence of nodal metastasis.

Biopsy was reported as well differentiated squamous cell carcinoma.

Since the mass was involving the anterior portion of the left side of tongue the patient was taken up for surgical resection of the mass - Hemiglossectomy.
This patient underwent hemiglossectomy via intra oral route - without splitting the mandible as there was no ankyloglossia / trismus.  Due to full mouth opening surgical exposure was good and the posterior border of the mass was clearly found not involving the posterior 1/3 of tongue. 

Clinical photograph of the patient

After surgery the patient was submitted for a course of post op radiotherapy to take care of micro nodal metastasis.

Pediatric Laryngoscopes

Introduction:
     This article is relevant in the present day scenario as more and more children under go endolaryngeal surgeries.  With efficient neonatal intensive care units, large number of premature / low birth weight babies thrive these days.  As the old adage goes "A child is not a miniature adult" it is imperative that equipment design should keep pace with the advancing science.  Pediatric larynx is unique in many ways.  It is placed high up in the neck, the overhanging omega shaped epiglottis makes visualization of larynx nearly impossible.  It is important to design laryngoscopes that could overcome these anatomical variations.  This article discusses the various laryngoscopes available for use in pediatric age group of patients.

Pediatric laryngoscopes can be classified into:


1. General purpose laryngoscopes

2. Laryngoscopes designed for special purposes



General purpose laryngoscopes:

These are designed with the intention of providing a good view of

oropharynx, laryngeal inlet and laryngopharynx of an infant.There are two

varieties of general purpose laryngoscopes:

Karl storz

Parson's.



Karl storz - The general purpose laryngoscope designed by karl storz can be used

for both diagnostic and intubation purposes.These are available in 4 sizes:

1. 8 cms for premature and newborns

2. 9.5 cms for infants

3. 11 cms for children

4. 13.5 cms for adolescents



These differing sizes will enable proper placement of the beak of laryngoscope

either in vallecula or behind the epiglottis. Proper placement of the beak of

laryngoscope will ensure better field of vision of oropharynx and laryngopharynx.

Illumination is provided by proximal prismatic deflector. Light is transmitted to the

prismatic deflector via a thin fibre optic cable which passes via the handle of the

laryngoscope.

Parsons laryngoscopes are a variety of paediatric laryngoscopes.


It is usually available in three sizes.



1. 8 cms for premature babies / new borns



1. 9.5 cms for infants



2. 11 cms for toddlers and older children



on being positioned over the posterior 1/3 of tongue a wide view of

laryngopharynx can be seen. It can be connected to suspension apparatus

helping the surgeon in laryngeal examination and surgeries leaving both

hands free. Another important advantage is the presence of a side port

on the left side through which a cannula can be introduced to pass anesthetic

gases. It has another port on the right side though which fibre optic

attachement can be passed for illumination purposes.



It is very useful in laser endolaryngeal surgeries.



Telescopes can also be passed through the left port for complete

examination of larynx and laryngopharynx.



Special purpose laryngoscopes: These are usually operating laryngoscopes used during surgical procedures

involving larynx. These include:



1.Benjamin Lindholm laryngoscope

2.Holinger Benjamin laryngoscope

3.Benjamin operating laryngoscope



Benjamin Lindholm laryngoscope: is available in two sizes.

9.5cms for premature babies and 11 cms for children from 18 months - 8 years of age

When the beak is placed a wide view of laryngopharnx is available. Since it is provided

with suspension system both arms are free for manipulation. It has a special cannula which

is fixed to the left side of the laryngoscope. Through this cannula anesthetic gases can

be insufflated. The laryngoscope provides a wide exposure for microlaryngeal and laser

surgeries.



Holinger Benjamin laryngoscopes:is manufactured in three sizes:



1. 9.5 cms with a very narrow distal end for very low birth weight new born babies

2. 9.5 cms with a larger distal end for new born babies

3. 11 cms for older children



By virtue of their design these laryngoscopes help in full visualization of anterior commissure,

posterior glottic space and subglottic area. This laryngoscope can be used for difficult intubation

scenarios. Since the blade of these laryngoscopes are slim and slightly upturned, it is helpful in

intubating patients with difficult mouth opening like Pierre Robin syndrome. This scope is very

useful in diagnosing congenital webs involving larynx.



Benjamin operating laryngoscopes:

These are available in two sizes. These scopes allow binocular vision during microlaryngeal / laser

surgeries. These scopes are provided with portal for anesthetic gas insufflation.
 
 
 

This image shows a Parson's laryngoscope

Lindholm's laryngoscope

History of frontal sinus surgery

The first frontal sinus surgical procedure was first described in 1750. Despite more than 2 centuries since the description of the procedure on frontal sinus, the optimal procedure is still not clear. Frontal sinus disease could be highly morbid with the danger of life threatening complications, because of its anatomic proximity to anterior skull base and orbit.

“Surgical treatment of chronic frontal sinusitis is difficult, often unsatisfactory and sometimes disastrous” Ellis 1954.

A brief history of frontal sinus surgery can be accessed from here: 

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