NEET MDS Lessons
General Surgery
Dautrey Procedure
The Dautrey procedure is a surgical intervention aimed at preventing dislocation of the temporomandibular joint (TMJ) by creating a mechanical obstacle that restricts abnormal forward translation of the condylar head. This technique is particularly beneficial for patients who experience recurrent TMJ dislocations or subluxations, especially when conservative management strategies have proven ineffective.
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Indications:
- The Dautrey procedure is indicated for patients with a history of recurrent TMJ dislocations. It is particularly useful when conservative treatments, such as physical therapy or splint therapy, have failed to provide adequate stabilization of the joint.
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Surgical Technique:
- Osteotomy of the Zygomatic Arch: The procedure begins with an osteotomy, which involves surgically cutting the zygomatic arch, the bony structure that forms the prominence of the cheek.
- Depressing the Zygomatic Arch: After the osteotomy, the zygomatic arch is depressed in front of the condylar head. This depression creates a physical barrier that acts as an obstacle to the forward movement of the condylar head during jaw opening or excessive movement.
- Stabilization: The newly positioned zygomatic arch limits the range of motion of the condylar head, thereby reducing the risk of dislocation during functional activities such as chewing or speaking.
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Mechanism of Action:
- By altering the position of the zygomatic arch, the Dautrey procedure effectively changes the biomechanics of the TMJ. The new position of the zygomatic arch prevents the condylar head from translating too far forward, which is a common cause of dislocation.
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Postoperative Care:
- Following the procedure, patients may require a period of recovery
and rehabilitation. This may include:
- Dietary Modifications: Soft diet to minimize stress on the TMJ during the healing process.
- Pain Management: Use of analgesics to manage postoperative discomfort.
- Physical Therapy: Exercises to restore normal function and range of motion in the jaw.
- Following the procedure, patients may require a period of recovery
and rehabilitation. This may include:
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Outcomes:
- The Dautrey procedure has been shown to be effective in preventing recurrent TMJ dislocations. Patients often experience improved joint stability and a better quality of life following the surgery. Successful outcomes can lead to reduced pain, improved jaw function, and enhanced overall satisfaction with treatment.
Types of Head Injury
1. Extradural Hematoma (EDH)
Overview
- Demographics: Most common in young male patients.
- Association: Always associated with skull fractures.
- Injured Vessel: Middle meningeal artery.
- Common Site of Injury: Temporal bone at the pterion (the thinnest part of the skull), which overlies the middle meningeal artery.
- Location of Hematoma: Between the bone and the dura mater.
Other Common Sites
- Frontal fossa
- Posterior fossa
- May occur following disruption of major dural venous sinus.
Classical Presentation
- Initial Injury: Followed by a lucid interval where the patient may only complain of a headache.
- Deterioration: After minutes to hours, rapid
deterioration occurs, leading to:
- Contralateral hemiparesis
- Reduced consciousness level
- Ipsilateral pupillary dilatation (due to herniation)
Imaging
- CT Scan: Shows a lentiform (lens-shaped or biconvex) hyperdense lesion between the brain and skull.
Treatment
- Surgical Intervention: Immediate surgical evacuation via craniotomy.
- Mortality Rate: Overall mortality is 18% for all cases of EDH, but only 2% for isolated EDH.
2. Acute Subdural Hematoma (ASDH)
Overview
- Location: Accumulates in the space between the dura and arachnoid.
- Injury Mechanism: Associated with cortical vessel disruption and brain laceration.
- Primary Brain Injury: Often associated with primary brain injury.
Presentation
- Consciousness: Impaired consciousness from the time of impact.
Imaging
- CT Scan: Appears hyperdense, with hematoma spreading diffusely and having a concavo-convex appearance.
Treatment
- Surgical Intervention: Evacuation via craniotomy.
- Mortality Rate: Approximately 40%.
3. Chronic Subdural Hematoma (CSDH)
Overview
- Demographics: Most common in patients on anticoagulants and antiplatelet agents.
- History: Often follows a minor head injury weeks to months prior.
- Pathology: Due to the tear of bridging veins leading to ASDH, which is clinically silent. As the hematoma breaks down, it increases in volume, causing mass effect on the underlying brain.
Clinical Features
- Symptoms may include:
- Headache
- Cognitive decline
- Focal neurological deficits (FND)
- Seizures
- Important to exclude endocrine, hypoxic, and metabolic causes in this group.
Imaging
- CT Scan Appearance:
- Acute blood (0–10 days): Hyperdense
- Subacute blood (10 days to 2 weeks): Isodense
- Chronic (> 2 weeks): Hypodense
Treatment
- Surgical Intervention: Bur hole evacuation rather than craniotomy.
- Anesthesia: Elderly patients can often undergo surgery under local anesthesia, despite comorbidities.
4. Subarachnoid Hemorrhage (SAH)
Overview
- Causes: Most commonly due to aneurysms for spontaneous SAH, but trauma is the most common cause overall.
- Management: Conservative treatment is often employed for trauma cases.
5. Cerebral Contusions
Overview
- Definition: Bruising of the brain tissue due to trauma.
- Mechanism: Often occurs at the site of impact (coup) and the opposite side (contrecoup).
- Symptoms: Can range from mild confusion to severe neurological deficits depending on the extent of the injury.
Imaging
- CT Scan: May show areas of low attenuation (hypodense) or high attenuation (hyperdense) depending on the age of the contusion.
Treatment
- Management: Depends on the severity and associated injuries; may require surgical intervention if there is significant mass effect.
Cricothyroidotomy
Cricothyroidotomy is a surgical procedure that involves making an incision through the skin over the cricothyroid membrane, which is located between the thyroid and cricoid cartilages in the neck. This procedure is performed to establish an emergency airway in situations where intubation is not possible or has failed, such as in cases of severe airway obstruction, facial trauma, or anaphylaxis.
Indications
Cricothyroidotomy is indicated in the following situations:
- Acute Airway Obstruction: When there is a complete blockage of the upper airway due to swelling, foreign body, or trauma.
- Failed Intubation: When attempts to secure an airway via endotracheal intubation have been unsuccessful.
- Facial or Neck Trauma: In cases where traditional airway management is compromised due to injury.
- Severe Anaphylaxis: When rapid airway access is needed and other methods are not feasible.
Anatomy
- Cricothyroid Membrane: The membrane lies between the thyroid and cricoid cartilages and is a key landmark for the procedure.
- Surrounding Structures: Important structures in the vicinity include the carotid arteries, jugular veins, and the recurrent laryngeal nerve, which must be avoided during the procedure.
Procedure
Preparation
- Positioning: The patient should be in a supine position with the neck extended to improve access to the cricothyroid membrane.
- Sterilization: The area should be cleaned and sterilized to reduce the risk of infection.
- Anesthesia: Local anesthesia may be administered, but in emergency situations, this step may be skipped.
Steps
- Identify the Cricothyroid Membrane: Palpate the thyroid and cricoid cartilages to locate the membrane, which is typically located about 1-2 cm below the thyroid notch.
- Make the Incision: Using a scalpel, make a vertical incision through the skin over the cricothyroid membrane, approximately 2-3 cm in length.
- Incise the Membrane: Carefully incise the cricothyroid membrane horizontally to create an opening into the airway.
- Insert the Airway Device:
- A tracheostomy tube or a large-bore cannula (e.g., a 14-gauge catheter) is inserted into the opening to establish an airway.
- Ensure that the device is positioned correctly to allow for ventilation.
- Secure the Airway: If using a tracheostomy tube, secure it in place to prevent dislodgment.
Post-Procedure Care
- Ventilation: Connect the airway device to a bag-valve-mask (BVM) or ventilator to provide oxygenation and ventilation.
- Monitoring: Continuously monitor the patient for signs of respiratory distress, oxygen saturation, and overall stability.
- Consider Further Intervention: Plan for definitive airway management, such as a formal tracheostomy or endotracheal intubation, once the immediate crisis is resolved.
Complications
While cricothyroidotomy is a life-saving procedure, it can be associated with several complications, including:
- Infection: Risk of infection at the incision site.
- Hemorrhage: Potential bleeding from surrounding vessels.
- Damage to Surrounding Structures: Injury to the recurrent laryngeal nerve, carotid arteries, or jugular veins.
- Subcutaneous Emphysema: Air escaping into the subcutaneous tissue.
- Tracheal Injury: If the incision is not made correctly, there is a risk of damaging the trachea.
Suture Materials
Sutures are essential in surgical procedures for wound closure and tissue approximation. Various types of sutures are available, each with unique properties, advantages, and applications. Below is a summary of some commonly used suture materials, including chromic catgut, polypropylene, polyglycolic acid, and polyamide (nylon).
1. Chromic Catgut
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Description:
- Chromic catgut is a natural absorbable suture made from collagen derived from the submucosa of sheep intestines or the serosa of beef cattle intestines. It is over 99% pure collagen.
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Absorption Process:
- The absorption of chromic catgut occurs through enzymatic digestion by proteolytic enzymes, which are derived from lysozymes contained within polymorphonuclear leukocytes (polymorphs) and macrophages.
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Absorption Rate:
- The absorption rate depends on the size of the suture and whether it is plain or chromicized. Typically, absorption is completed within 60-120 days.
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Applications:
- Commonly used in soft tissue approximation and ligation, particularly in areas where a temporary support is needed.
2. Polypropylene (Proline)
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Description:
- Polypropylene is a synthetic monofilament suture made from a purified and dyed polymer.
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Properties:
- It has an extremely high tensile strength, which it retains indefinitely after implantation. Polypropylene is non-biodegradable, meaning it does not break down in the body.
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Applications:
- Ideal for use in situations where long-term support is required, such as in vascular surgery, hernia repairs, and other procedures where permanent sutures are beneficial.
3. Polyglycolic Acid
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Description:
- Polyglycolic acid is a synthetic absorbable suture formed by linking glycolic acid monomers to create a polymer.
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Properties:
- It is known for its predictable absorption rate and is commonly used in various surgical applications.
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Applications:
- Frequently used in soft tissue approximation, including in gastrointestinal and gynecological surgeries, where absorbable sutures are preferred.
4. Polyamide (Nylon)
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Description:
- Polyamide, commonly known as nylon, is a synthetic non-absorbable suture that is chemically extruded and generally available in monofilament form.
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Properties:
- Nylon sutures have a low coefficient of friction, making passage through tissue easy. They also elicit minimal tissue reaction.
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Applications:
- Used in a variety of surgical procedures, including skin closure, where a strong, durable suture is required.
1 Cellulitis: a non-suppurative inflammation of subcutaneous tissue, extending along connective tissue planes and across intercellular spaces.
Spreading inflammation in the tissue planes is called cellulitis. There is wide spread swelling, redness and pain without definite localization.
Caused by Streptococcus pyogenes.. If general condition of the patient is undermined, as in diabetes, cellulitis spreads rapidly and leads to Septicemia (infection in the blood).Redness, itching and stiffness is present in the site of inoculation (where the bacteria enter the skin), local Gangrene (death of the tissue) may occur. The appearance of skin creases or wrinkles, indicates resolution (healing).
Treatment
1. Rest , Appropriate antibiotics.
Cellulitis of the neck: Is a complication of wounds tonsillitis or mastoiditis Ludwig’s angina is the term applied to sub-maxillary cellulitis. The two dangers of cervical cellulitis are:
1. Oedema of glottis - with possible asphyxia (respiratory obstructon )
2. Mediastinitis - In ludwig’s angina the floor of the mouth become oedematous. The tongue can be seen displaced, turned upwards by swelling and oedema. The patient is unable to close the mouth owing to oedema of the tongue and the floor of the mouth. This can also CCC when the tongue is bitten by a wasp.
Ludwig’s angina: Ludwig - characterized by a brawny (non pitting) swelling of the sub-mandibular region, corn with inflammatory oedema of the mouth. It is the combined cervical and intrabuccal signs that constitute the characteristic feature of the lesion. The cause of the condition is virulent, usually streptococcal infection of the cellular tissue surrounding the sub-mandibular salivary gland.
Clinical features
The swollen tongue is pushed towards the palate and forwards through the open mouth, while the cellulitis extends down the neck.
The most dangerous plane, is deep to the deep fascia.
Ludwig’s angina is an infection of closed fascial space and if .untreated, the inflammatory exudate often passes via, the tunnel occupied by stylohyhoid to the submucosa of glottis, in which event the patient is in immediate danger of death from oedema of the glottis.
Treatment
1. antibiotics on Early Diagnosis
2. In cases where the swelling, both cervical and intrabuccal, does not subside rapidly with such treatment, a curved incision, beneath the jaw is made and this decompresses the closed fascial space. The incision is deepened and after displacing the superficial lobe of the sub-mandibular salivary gland, the mylohyoid muscle are divided. This decompresses the closed fascjal space referred to. The wound is lightly sutured and drained. The operation can be conducted with greatest safety under local anaesthesia.
Bacteraemia and Septicemia
Bacteraemia and septicaemia means the organisms are present in the blood. Clinical features are those of severe infection and shock: , Pyrexia is intermittent , Rigors , Jaundice is due to liver damage, Acute renal failure may occur , Peripheral circulatory failure, lntravascular coagulation indicates a fatal outcome
causative focus found and treated surgically .g., Appendicetomy in perforated appendix
2. Blood culture taken
3. Broad spectrum antibiotic is given
4. Blood transfusion is given.
5. Injection hydrocortisone is given.
Pyaemia
Pyaemia is due to infected emboli circulating in blood stream. Pyaemia is characterized by: -
1. Rigors
2. Intermittent fever
3. Formation of abscess in vital organs like heart or brain.
Treatment
1. Is to prevent emboli reaching the blood stream
2. Broad spectrum antibiotic is given.
3. Abscess are incised and drained
If not treated portal pyaemia with multiple abscesses in liver occur, which is a dangerous condition.
Acute Abscess : An abscess a collection of pus.
Bacteria which cause pus formation is called pyogenic organisms. Bacteria reach the infected area by:
1. Direct route: eg. Penetrating wound
Local extension: From adjacent focus of infection
2 Lymphatics
4. Blood stream
Pyogenic membrane surrounds the abscess and is infiltration with (leukocytes and bacteria.
Pus: Pus contains dead leukocytes and bacteria. It reaches the surface of the body or is discharged into a hollow viscous.
Symptoms: patient feels ill., Throbbing pain is characteristic of suppuration. Pain becomes more severe in the dependent position. E.g. infected finger,
Classical signs
Temperature is elevated , Rigors, inflammation
Fluctuation: Present in the later stages, and reveals the presence of pus. Prevention
1. An abscess can sometimes be aborted by antibiotics in the early stage.,. Rest, Elevation of the affected part.
Treatment
Is incision and drainage of abscess
Hilton’s method of opening an abscess:
It is used where important anatomical structures like the blood vessels and nerves are preesnt, as in the neck, axilla and groin. The skin and superficial fascia is incised. A sinus forceps is thrust into the abscess cavity. The blades are opened and the pus is drained. A gloved finger is introduced and loculi are broken. A ribbon gauze is lightly packed and antibiotics are given. This is done under surface anaesthesia i.e., ethyl chloride spray.
Antibioma
If antibiotic is given the pus in the abscess frequently becomes sterile and a large brawny edematous swelling remains which takes many weeks to resolve.
Treatment: explore the mass with a wide-bore aspirating needle
Most antibiornas are due to late, inadequate, and ineffective antibiotics.
CANCRUM ORIS
Is an infective gangrene of cheek and lip.
may occur as a complication of kala azar, enteric fever and children with poor oral hygiene.
The lesion starts as an acute inflammatory patch on oral mucosa which is seen ulcerated.
The affected part of the cheek or the lip gradually becomes gangrenous.
Focal vascular thrombosis and sepesis occur.
When slough separates, a part of the cheek or lip sloughs out to form a buccal fistula with ugly deformity. The adjacent jaw may be infected too.
Various organisms are found - specially Fusiform bacillus and_Borrellia vincenti.
The foetid odour, gangrenous patch of cheek or lip, purulent discharge from the mouth, fever and toxaemia are the characteristic features. The patient is unable to open the mouth properly.
Treatment
1. Antibiotics, multivitamins and repeated mouth washes
2 Neostibamine in kala-azar. Sequestrectomy in chronic osteomyelitis of the mandible.
4. Plastic reconstruction of the lip or cheek for unsightly deformity undertaken.
CARBUNCLE
Is an infective gangrene of the subcutaneous tissue. It is due to staphylococcal aureus infection. It is uncommon before the age of 40. Males are the usual sufferers. Diabetes may be present. It often occurs on the nape of the neck.
Clinical features
Subcutaneous tissue becomes painful and indurated. Ove skin is red. Unless treated promptly, extension will occur and late softening. The skin gives way and thick pus and slough are discharged.
Usually, there is one central large slough, surrounded by smaller areas of necrosis. Infection extends widely and fresh openings appear
Treatment
1. Many carbuncles are aborted, if penicillin is used adequately in the early stage.
2. Local treatment consists of hygroscopic dressings being given ie. magsulph-glycerin dressing Later the carbuncle is excised with a cruciate incision.
3. If the gap is large and when the granulation tissue comes to the surface, skin grafting is done.
Inflammation is the respone of the body to an irritant.
Stages of Inflammation
1. General: Temperature Raised. In severe cases bacteremia or septicemia ,rigors may occur.
2. Local: classical signs of inflammation are due to hyperemia and inflammation exudate
i) Heat: inflammed area feels warmer than the surrounding tissues.
ii) Redness
iii) Tenderness: Due to pressure of exudate on the surrounding nerves If the exudate is under tension, e.g. a furuncle (boil) of the ear, pain is severe.
iv) swelling
v) Loss of function.
The termination of Inflammation
This may be by:1. Resolution 2. Suppuration 3. Ulceration 4. Ganangren s. Fibrosis
Management
i. Increase the patients resistance., Rest, Relief of pain by analgesics, Diet: High protein and high calorie diet with vitamins, Antibiotics, Prevent further contamination of wound.
Surgical measures
1. Excision: If possible as in appendicectomy.
2. Incision and drainage: If an abscess forms.
Tracheostomy
Tracheostomy is a surgical procedure that involves creating an opening in the trachea (windpipe) to facilitate breathing. This procedure is typically performed when there is a need for prolonged airway access, especially in cases where the upper airway is obstructed or compromised. The incision is usually made between the 2nd and 4th tracheal rings, as entry through the 1st ring can lead to complications such as tracheal stenosis.
Indications
Tracheostomy may be indicated in various clinical scenarios, including:
- Acute Upper Airway Obstruction: Conditions such as severe allergic reactions, infections (e.g., epiglottitis), or trauma that obstruct the airway.
- Major Surgery: Procedures involving the mouth, pharynx, or larynx that may compromise the airway.
- Prolonged Mechanical Ventilation: Patients requiring artificial ventilation for an extended period, such as those with respiratory failure.
- Unconscious Patients: Situations involving head injuries, tetanus, or bulbar poliomyelitis where airway protection is necessary.
Procedure
Technique
- Incision: A horizontal incision is made in the skin over the trachea, typically between the 2nd and 4th tracheal rings.
- Dissection: The subcutaneous tissue and muscles are dissected to expose the trachea.
- Tracheal Entry: An incision is made in the trachea, and a tracheostomy tube is inserted to maintain the airway.
Complications of Tracheostomy
Tracheostomy can be associated with several complications, which can be categorized into intraoperative, early postoperative, and late postoperative complications.
1. Intraoperative Complications
- Hemorrhage: Bleeding can occur during the procedure, particularly if major blood vessels are inadvertently injured.
- Injury to Paratracheal Structures:
- Carotid Artery: Injury can lead to significant hemorrhage and potential airway compromise.
- Recurrent Laryngeal Nerve: Damage can result in vocal cord paralysis and hoarseness.
- Esophagus: Injury can lead to tracheoesophageal fistula formation.
- Trachea: Improper technique can cause tracheal injury.
2. Early Postoperative Complications
- Apnea: Temporary cessation of breathing may occur, especially in patients with pre-existing respiratory issues.
- Hemorrhage: Postoperative bleeding can occur, requiring surgical intervention.
- Subcutaneous Emphysema: Air can escape into the subcutaneous tissue, leading to swelling and discomfort.
- Pneumomediastinum and Pneumothorax: Air can enter the mediastinum or pleural space, leading to respiratory distress.
- Infection: Risk of infection at the incision site or within the tracheostomy tube.
3. Late Postoperative Complications
- Difficult Decannulation: Challenges in removing the tracheostomy tube due to airway swelling or other factors.
- Tracheocutaneous Fistula: An abnormal connection between the trachea and the skin, which may require surgical repair.
- Tracheoesophageal Fistula: An abnormal connection between the trachea and esophagus, leading to aspiration and feeding difficulties.
- Tracheoinnominate Arterial Fistula: A rare but life-threatening complication where the trachea erodes into the innominate artery, resulting in severe hemorrhage.
- Tracheal Stenosis: Narrowing of the trachea due to scar tissue formation, which can lead to breathing difficulties.