Wound Sinus And Fistula Notes

Wound Sinus And Fistula Wound

A wound is a discontinuity or break in the surface epithelium. A wound is simple when only skin is involved. It is complex when it involves underlying nerves, vessels, tendons, etc.

Types of Wounds

1. Closed Wounds

• Contusion
• Abrasion
• Haematoma

Contusion: It can be a minor soft tissue injury without a break in the skin or sometimes it can be major due to run over by a vehicle. Generally, it produces discolouration of the skin due to the collection of blood underneath.

Abrasion: In this wound, the epidermis of the skin is scraped away thus exposing the dermis. They are painful as dermal nerve endings are exposed. These wounds need cleaning, antibiotics and proper dressings.

Read And Learn More: Clinical Medicine And Surgery Notes

Haematoma: This refers to a collection of blood. It follows injury or occurs spontaneously as in patients who have bleeding tendencies such as haemophilia. Depending upon the site, it can be subcutaneous, intramuscular or even subperiosteal. Haematoma in the knee joint may have to be aspirated followed by compression bandage. Small haematomas get absorbed, if not may get infected.

2. Open Wounds

• Incised
• Lacerated
• Penetrating
• Crushed

Incised Wounds: They are caused by sharp objects like knives, blades, glass, etc. This type of wound has a sharp edge and is less contaminated. Primary suturing is ideal for such wounds, as it gives a neat and clean scar.

Lacerated Wounds: They are caused by blunt objects like a fall on a stone or due to road traffic accidents. Edges are jagged. The injury may involve only skin and subcutaneous tissue or sometimes deeper structures.

• Due to the blunt nature of the object, there is crushing of the tissue which may result in haematoma, bruising or even necrosis of the tissue. These wounds are treated by wound excision and primary suturing provided they are treated within six hours of the injury.

Penetrating Wounds: They are not uncommon nowadays. Stab injuries of the abdomen are very notorious. It may look like an innocent injury with a small, one or two cm long, cut. But internal organs like intestines, liver, spleen or mesenteric blood vessels might have been damaged.

• All penetrating wounds of the abdomen should be admitted and observed for at least 24 hours. Layer-by-layer exploration and repair, though recommended, may not be possible at times due to the oblique track of the wound.

Crushed Or Contused Wounds: They are caused by blunt trauma due to run over by a vehicle, wall collapse, earthquakes or industrial accidents. These wounds are dangerous as they may cause severe haemorrhage, death of the tissues and crushing of blood vessels.

• These patients are more prone to gas gangrene, tetanus, etc. Adequate treatment involves a good debridement and removal of all dead and necrotic tissues.

Classification Of Wounds

General Principles Of Management Of Wound

• Admission or observation in the hospital.
• Monitoring of temperature, pulse and respiration.
• Systemic antibiotics depend upon the contamination of the wound.
• Injection of tetanus toxoid for prophylaxis against tetanus.
• Treatment of the wound in the form of cleaning, dressing or suturing.

Healing Of The Wound

• Healing by primary intention occurs in a clean incised wound such as a surgical incision wherein there is only a potential space between the edges. It produces a clean, neat and thin scar.
• Healing by secondary intention refers to a wound that is infected, discharging pus or wound with skin loss. Such wounds heal with an ugly scar.

Components of Wound Healing

1. Epithelialisation occurs mainly from the edges of the wound by a process of cell migration and cell multiplication. This is mainly brought about by marginal basal cells. Thus, within 48 hours entire wound is re-epithelialised. When there is a wound with skin loss, skin appendages also help in epithelialisation. Slowly, surface cells get keratinised.
2. Wound contraction: It starts after 4 days and is usually completed by 14 days. It is brought about by specialised fibroblasts. Because of their contractile elements, they are called myofibroblasts. It is nature’s way of reducing the size of the defect thereby helping the wound heal. Wound contraction readily occurs when there is loose skin as in the back, gluteal region, etc.
   • Skin contraction is greatly reduced when it occurs over the tibia (skin) or malleolar surface. Corticosteroids, irradiation, and chemotherapy delay wound contraction.
3. Connective tissue formation: The formation of granulation tissue is the most important and fundamental step in wound healing. (It can be compared to concrete slab laying.)
   • Injury results in the release of mediators of inflammation, mainly histamine from platelets, mast cells and granulocytes. This results in increased capillary permeability.
   • Later kinins and prostaglandins act and they play a chemotactic role for white cells and fibroblasts.

Classification Of Wounds

• In the first 48 hours, polymorphonuclear leukocytes dominate. They play the role of scavengers by removing the dead and necrotic tissue.
• Between the 3rd and 5th day, polymorphonuclear leukocytes diminish in number but monocytes increase. They are specialised scavengers.
• By 5th or 6th day, fibroblasts appear, proliferate and eventually give rise to a protocollagen which is converted into collagen in the presence of an enzyme protocollagen hydroxylase. Oxygen, ferrous ions and ascorbic acid are necessary for this step.
• Fibroplasia along with capillary budding gives rise to granulation tissue.
• Secretion of ground substance—mucopolysaccharides by fibroblasts. These are called proteoglycans. They help in the binding of collagen fibres. Thus, the wound is filled with FIBRE GEL – FLUID SYSTEM (iron rods + Cement + Water used for concrete slab).

4. Scar formation: The following changes take place during scar formation.

• Fibroplasia and the laying of collagen are increased.
• Vascularity becomes less (devascularisation).
• Epithelialisation continues
• Ingrowth of lymphatics and nerve fibres takes place.
• Remodelling of collagen takes place with cicatrisation, resulting in a scar.

Classification Of Wounds

Complications of Wound Healing

1. Infection: It is the most important complication responsible for delay in wound healing. The majority of bacteria are endogenous. Depending upon the pus/culture sensitivity report, appropriate antibiotics are given.
2. Ugly scar: It is the result of infections
3. Keloid and hypertrophic
4. Incisional hernia and wound dehiscence
5. Pigmentation of the skin
6. Marjolin’s ulcer

Factors Affecting Wound Healing

Wound Closure or Wound Suturing

1. Primary suturing

Suturing the wound within a few hours following an injury (six hours is ideal) is called primary suturing.

Primary suturing can be done provided

• It is an incised or cut wound with a sharp object like a knife or razor blade.
• Minimal injury to structures on either side.
• There should not be any infection. If a wound is sutured in the presence of infection the suture material is eaten away (digested) by organisms which results in gaping of the wound.

Precautions to be taken while doing a primary suturing

• The foreign body, if present in the deeper aspect of the wound, should be removed.
• Associated injury to blood vessels, nerves or tendons to be recognised and repaired.
• A wound on the abdomen may have associated visceral injuries.
• Prevention of tetanus by using tetanus toxoid 0.5 ml intramuscularly.

2. Wound excision and primary suturing of skin

This is indicated when:

• Wound edges are jagged
• Contamination of wounds with organisms or foreign bodies.
• Tissues are crushed and devitalised.
• In such situations, the wound is explored, and devitalised tissues and foreign bodies, if present, are removed. The wound is irrigated with antiseptic agents. Thus, a lacerated wound is converted into an incised wound and then sutured.

Precautions to be taken are

• Should be done within 6 hours.
• Tetanus and gas gangrene prophylaxis.
• Repair of tendons and nerves can be done at a later date if contamination is excessive.

3. Wound excision and delayed primary suture

This is indicated in lacerated wounds with major crush injuries.

Primary suturing within 6 hours is not done in these wounds because of the following

• Gross oedema of the part
• Increased tissue tension
• Haematoma
• Contamination with bacteria
• In such situations, excision of all dead tissue is done. The wound is irrigated with antiseptic agents like betadine, hydrogen peroxide solution, etc. and is left open without suturing and dressing is applied.
• The wound is re-examined 4–6 days later. If there is no infection or no nonviable tissues, the wound is sutured. This two-stage procedure is called delayed primary suturing.

4. Wound with skin loss

It can follow surgical procedures or accidents or due to tissue loss.

Complications of skin loss

• Secondary infection of the wound.
• The underlying structures like tendons and nerves are in danger.
• Diabetic patients can develop septicaemia.
• Deformity and disability can occur at a later date.

Hence, as soon as possible, skin grafting should be done.

5. Secondary suturing

After operations, sutures may give way because of severe infection with persistent discharge of pus. In such cases 7–14 days later, after controlling infection, skin is freed from the edge of the wound from the granulation tissue and the skin is approximated. This type of suturing is called secondary suturing.

Factors Affecting Wound Healing

1. Factors Affecting Wound Healing – General factors

1. Age: In children, wounds heal faster. Healing is delayed in old age.
2. Debilitation results in malnutrition. Wound healing is delayed probably because of vitamin C deficiency. Following injury, vitamin C deficiency can occur after 3–4 weeks. Vitamin C is necessary for the synthesis and maintenance of collagen. Zinc deficiency is known to delay the healing of the pilonidal sinus.
3. In diabetic patients, wound healing is delayed because of several factors such as microangiopathy, atherosclerosis, decreased phagocytic activity, the proliferation of bacteria due to high blood sugar, etc.
4. Jaundiced and uraemic patients have poor wound healing because fibroblastic repair is delayed.
5. Cytotoxic drugs and malignancy.
6. Generalised infection: Pus in some parts of the body delays wound healing.
7. Corticosteroids given early may delay wound healing because of anti-inflammatory activity. Once healing is established they do not interfere.

2. Factors Affecting Wound Healing Local factors

1. Poor blood supply: The wound over the knee and shin of the tibia heal very slowly but the wound on the face heal fast.
2. Local infection: Organisms eat away the suture material, destroy granulation tissue and cause slough and purulent discharge. Collagen synthesis is reduced and collagenolysis is increased. If contamination occurs, antibiotics should be given immediately or within 2 hours to prevent infection.
3. Haematoma precipitates infection.
4. Faulty technique of wound closure.
5. Tension at the wound while suturing.
6. Oxygen: Oxygen enhances the killing property of macrophages and increases the production of fibroblasts.

Asepsis And Antisepsis

Strictly speaking, they are equivalent, there is not much of a difference between these.

Medical Asepsis

Medical Asepsis  means precautions taken before any surgical procedure, against the development of infection.

Medical Asepsis Examples

• Wearing gloves before any procedure.
• Cleaning the part with iodine and spirit.
• Sterilisation of instruments.
• Autoclaving.

Antisepsis: All the surgical procedures are done today only after taking precautions.

• Dressing of an already contaminated wound using carbolic acid, and iodine.
• Broad-spectrum antibiotics are used in the presence of infection.
• Wearing a mask and cap in the operation theatre.

Nosocomial Infections

An acquired infection from the hospital is called a nosocomial infection.

• Infection can be from the patient’s own organisms (self-infection) or organisms from external sources.

Examples Of Nosocomial Infections : In surgical wards, discharging wounds, infected urine, faeces, and sputum are all sources of nosocomial infection.

Common organisms: Staphylococci and gram-negative organisms. Thus, wound infection, bronchopneumonia, urinary tract infection and even septicaemia can occur. Gas gangrene can occur due to the patient’s own intestinal Clostridium.

Prevention of Hospital Infection

• Avoid unnecessary antibiotics to prevent the development of resistant organisms
• Autoclaving, sterilisation, etc.
• Proper ventilation of the wards
• Proper scrubbing before any procedure
• Proper disposal of urine, faeces, sputum
• Use of disinfectants.

Sinus And Fistula Sinus

• It is a blind track leading from the surface down into the tissues. It is lined with granulation tissue. Following are a few examples.

1. 1. Congenital sinus: Preauricular sinus
   2. Acquired sinus: Examples

• Median mental sinus: Occurs as a result of tooth abscess.
• Pilonidal sinus: Occurs in the midline in the anal region.

• Osteomyelitis: Gives rise to sinus discharging pus with or without bony spicules.
• The most common sinus in the neck is due to tubercular lymphadenitis. It discharges cheesy material. The skin surrounding the sinus shows bluish discolouration.

Fistula

It is an abnormal communication between the lumen of one viscus and the lumen of another (internal) or communication of one hollow viscus with the exterior, i.e. body surface (external fistula).

Examples of internal fistula

• Trachea-oesophageal fistula
• Colovesical fistula

Causes Of Persistence Of A Sinus Or Fistula

1. Presence of foreign body
2. Persistent infection
3. Distal obstruction
4. Absence of rest
5. Epithelialisation of the track
6. Malignancy
7. Non-dependent drainage, inadequate drainage
8. Dense fibrosis
9. Irradiation
10. Specific causes—Tuberculosis, Actinomycosis.

Examples of external fistula

• Orocutaneous fistula due to carcinoma of the oral cavity infiltrating the skin
• Branchial fistula
• Thyroglossal fistula

Clinical Examination Of Sinus And Fistula History

When did you first notice the fluid (discharge) coming out? Is it since birth or developed later? Congenital causes have been present since birth. Acquired lesions appear later.

• Did you have any trauma? Did you undergo any surgical procedures? Trauma and retained foreign bodies such as bullets, pellets, thorns and suture materials can give rise to sinuses. In fact, in the surgical wards, so-called stitch granuloma is an example of a sinus due to an infected foreign body such as sutures
• Did you have pain first and later swelling appeared which got ruptured? Typically seen in children it is osteomyelitis. Pain, fever, recurrent swelling and rupture are also seen in the pilonidal sinus and umbilical sinus.
• What is the colour and nature of the discharge? Serous fluid is seen when there is no infection as in a branchial cyst. White thick cheesy discharge is typical of tubercular sinus.
• Does it smell? foul smell is typically due to mixed infections. In the abdominal sinus, foul odour is not due to Escherichia. coli but caused by the proteolytic activity caused by anaerobic organisms.
• Did you notice any bony spicules? If present it indicates osteomyelitis. In surgical wards, diabetic ulcers over the calcaneal region or over the great toe may present with osteomyelitis (dead bone is called sequestrum). In Madura’s foot, multiple sinuses discharging yellow granules are typical.
• Cough with expectoration, multiple sinuses in the region of lymph nodes, and evening rise in temperature suggest tubercular aetiology.

Sinus And Fistula Inspection

1. The location gives the diagnosis in the majority of the cases of sinus or fistula.

Fistulas

• Branchial fistula: Anterior border of lower third of sternomastoid
• Parotid fistula: In the parotid region
• Thyroglossal fistula: Midline of the neck below the hyoid bone
• Appendicular fistula: Right iliac fossa

Sinuses

• Preauricular sinus: Front of the root of the helix of the ear due to failure of fusion of ear tubercles. The direction of the sinus is upwards and backward.
• Median mental sinus: Symphysis menti
• Tubercular sinus: Neck
• Lymphogranuloma: Groin

2. Number: Can be single or multiple

3. Opening

• Sprouting granulation tissue: Foreign body
• Flush with skin: Tuberculosis

4. Discharge

• White thin caseous—Tuberculosis
• Yellow purulent—Staphylococci
• Faecal—Faecal fistula
• Yellow granules—Actinomycosis
• Thin mucus discharge—Branchial fistula
• Urine — Urinary fistula

5. Surrounding Skin

• Red, angry looking—Inflammatory
• Bluish discolouration—Tuberculosis
• Pigmentation—Chronic sinus
• Skin excoriation—Faecal fistula.

Palpation

1. Temperature and tenderness are increased if there is inflammation of the sinus, for example. pilonidal sinus.

2. Discharge after application of pressure. It suggests the nature of fluid. White cheesy material can be due to TB sinus.

3. Induration is present in chronic fistula, actinomycosis, osteomyelitis, etc.

• In the tubercular sinus, induration is absent

4. Fixity

Osteomyelitis sinus is fixed to the bone and the median mental sinus may be fixed to the jaw bone.

5. Palpation at a deeper plane

• Enlarged nodes in tuberculosis or lymphogranuloma venereum.
• Thickening of mandible or bone
• Submandibular stone may be palpable as in submandibular fistula.

Palpation Relevant Clinical Examination

• Submandibular gland enlargement can be identified by digital examination.
• An alveolar abscess can be found in the median mental sinus.

Palpation Investigations

1. Complete blood picture (CBP- Haemoglobin %, total and differential count, erythrocyte sedimentation rate-ESR) ESR may be increased in cases of tuberculosis. Increased total count suggests infection.
2. Urine sugar, fasting blood sugar (FBS) and post-prandial blood sugar (PPBS) to rule out diabetes.
3. X-ray of the part: Osteomyelitis of mandible; toe, also to look for foreign body.
4. Fistulography or sinusography is done to know the exact extent or origin of the sinus or fistula.
5. Biopsy from the edge of the sinus is done if a specific aetiology is suspected, for example. tuberculosis, malignancy, etc.

Palpation Management

Following are a few examples:

• Sequestrectomy for osteomyelitis
• Control of tuberculosis for tubercular sinus in the neck
• Removal of the foreign body

Hypertrophic Scar And Keloid

As the name suggests there is hypertrophy of mature fibroblasts in hypertrophic scar. Blood vessels are minimal in this condition. However, in keloid, the proliferation of immature fibroblasts with immature blood vessels is found. These two conditions represent variations in the normal process of wound healing.

Hypertrophic Scar And Keloid Basic Principles

• Antibiotics
• Adequate rest
• Adequate excision
• Adequate drainage

• Keloid is very common in Blacks and least common in Caucasians.
• Keloid is not a true tumour but has a marked tendency to local recurrence after excision.
• Keloid takes the shape of a butterfly over the sternum. The sternum is the most common site for a keloid. It is extremely difficult to treat the keloid over the sternum. We had one patient who underwent wide excision and grafting 6 times for a sternal keloid.

Miscellaneous

Healing of Specialised Tissues

Different tissues heal in different ways. For example, nerve cells of the brain and spinal cord cannot be replaced or repaired by nerve cells. Few examples are given.

Surgical Wounds

The success or result of the surgery depends upon the type of wound, location and experience of the surgeon. However, infection is an important aspect of surgical wounds. The classification and wound infection rate has been classified as given.