Meningocele Surgery Notes

Meningocele

Meningocele is a herniation of the meninges through the weak point in the spine (neural arch) where the bony fusion has not taken place effectively. The swelling is covered by pia mater and arachnoid mater without a dural covering. The swelling contains cerebrospinal fluid (CSF). Meningocoele is an example of spina bifida cystica.

Meningocoele—Sites

• Lumbosacral: The most common
• Occipitocervical: Second common
• Root of the nose:  Rare

Meningocele Clinical Features

1. The swelling has been present since birth.
2. Soft, cystic, and fluctuant with brilliant transillumination are the typical features of the swelling.
3. A sign of compressibility is present due to the displacement of CSF.
4. When the child cries or when asked to cough, an expansile impulse is present.
5. On palpating the edge of the swelling, a bony defect is usually found.

Read And Learn More: Clinical Medicine And Surgery Notes

Meningocele Treatment

• CT scan is done to look for hydrocephalus. If it is present, a ventriculoperitoneal shunt is done which will reduce the meningocele.
• Excision of the meningocele should be done as early as possible to prevent rupture and secondary infection.

Excision Of Meningocele

• Surgery: As early as possible after birth
• Early closure prevents infection
• Transverse elliptical incision
• Excision of the sac
• Closure of the defect by plication
• Approximation of the muscles

Meningocele Complications

1. The skin covering the swelling is very thin and so, is prone to ulceration. Due to ulceration, secondary infection and meningoencephalitis can occur.
2. Haemorrhage.

Spina Bifida Occulta

• In this condition, the neural arch is defective posteriorly. There is no visible swelling.
• It can be suspected when there is a tuft of hair, lipoma, naevus, or pigmented patch of skin overlying the lumbosacral region.
• The child is normal at birth. Neurological symptoms such as weakness, and sciatica-like pain may start appearing at puberty (neurogenic talipes equinus — club foot)
• During this time, because of growth, there may be traction on the spinal cord by a ligament called membrane reunions.
• An X-ray can demonstrate the bifid spine.
• Surgical excision of the membrane gives a permanent cure to the patient, if there are symptoms.

Types of Spina Bifida Cystica

1. Menigocoele
2. Meningomyelocele

(Contributed by Prof. Vijaykumar, Paediatric Surgeon, KMC, Manipal)

• Protrusion of meninges, with nerve root of the spinal cord or disordered spinal cord results in meningomyelocele.
• Neurological deficits like foot drop, talipes, and trophic ulcer of the foot (S1 root) may be present.
• Surgical excision may be followed by residual neurological deficit.
• In every case of trophic ulcer spine examination should be done.

3. Syringomeningomyelocoele

• In this condition, in addition to the meninges the central canal of the spinal cord is also herniated out.
• Most of the children are stillborn.
• Very difficult to treat, if the child survives.

Differential Diagnosis Of Midline Swelling In The Neck

Midline Swellings: From Above Downwards

1. Ludwig’s angina
2. Enlarged submental lymph nodes
3. Sublingual dermoid cyst
4. Subhyoid bursitis
5. Thyroglossal cyst
6. Enlarged isthmus of thyroid gland
7. Pretracheal and pre-laryngeal lymph nodes
8. Retrosternal goitre
9. Thymic swelling
10. Enlarged lymph nodes or lipoma in the suprasternal space of burns.

Ludwig’S Angina

• This is an inflammatory oedema of the floor of the mouth. It spreads to the submandibular region and submental region.
• Tense, tender, brawny oedematous swelling in the submental region with putrid halitosis is characteristic of this condition.

Enlarged Submental Lymph Nodes

The three important causes of enlargement:

1. Tuberculosis: Matted submental nodes, firm in consistency, with enlarged upper deep cervical lymph nodes, with or without evening rise of temperature are suggestive of tuberculosis.
2. Non-Hodgkin’s lymphoma can present with submental nodes along with other lymph nodes in the horizontal group of nodes such as submandibular, upper deep cervical, pre-auricular, postauricular and occipital lymph nodes (external Waldeyer’s ring). Nodes are firm or rubbery, discrete without matting.
3. Secondaries in the submental lymph nodes can arise from carcinoma of the tip of the tongue, floor of the mouth, and central portion of the lower lip. The nodes are hard in consistency and sometimes, fixed.

Sublingual Dermoid Cyst

• It is a type of sequestration dermoid cyst which occurs due to sequestration of the surface—ectoderm at the site of fusion of the two mandibular arches. Hence, such a cyst occurs in the midline of the floor of the mouth.
• When they arise from 2nd branchial cleft, they are found lateral to the midline. Hence, lateral variety.
• The cyst is lined by squamous epithelium and contains hair follicles, sebaceous glands and sweat glands. It does not contain hair.

Sublingual Dermoid Cyst

• Origin: At the site of fusion of 2nd branchial arches
• Site: Midline-Common; Lateral—Uncommon
• Supraomohyoid variety is common
• Bidigital palpation for demonstration of fluctuation
• Soft, cystic, fluctuant, transillumination negative swelling

Differential Diagnosis

• Ranula—transillumination is a positive
• Thyroglossal cyst—moves with deglutition

Sublingual Dermoid Cyst Clinical Features

1. Young children or patients between the ages of 10 and 20 years present with painless swelling in the floor of the mouth.
2. The swelling is soft and cystic. The fluctuation test is positive. Bidigital palpation gives a better idea about fluctuation with one finger over the swelling in the oral cavity and the other finger in the submental region.
3. The transillumination test is negative as it contains thick, cheesy, sebaceous material.

Sublingual Dermoid Cyst Differential diagnosis

1. Ranula: When a sublingual dermoid cyst is in the midline on the floor of the mouth and above the mylohyoid muscle, a ranula is considered a differential diagnosis. However, the ranula is bluish in colour and brilliantly transilluminate.
2. The thyroglossal cyst should be considered as a differential diagnosis when the sublingual dermoid cyst is below the mylohyoid muscle. A thyroglossal cyst moves up with deglutition whereas a sublingual dermoid cyst does not.

Sublingual Dermoid Cyst Treatment

Through the intraoral approach, excision can be done for both types of sublingual dermoid cysts.

Subhyoid Bursitis

• Accumulation of inflammatory fluid in the subhyoid bursa results in swelling and is described as subhyoid bursitis.
• The bursa is located below the hyoid bone and in front of the thyrohyoid membrane.

Subhyoid Bursitis Clinical Features

1. The swelling in front of the neck, in the midline below the hyoid bone.
2. The swelling is oval in the transverse direction.
3. It moves up with deglutition.
4. Soft, cystic, fluctuant and transillumination negative swelling (turbid fluid).
5. The swelling may be tender as it contains inflammatory fluid.

Subhyoid Bursitis Treatment

• Complete excision

Subhyoid Bursitis  Complication

• It can develop into an abscess

Differential Diagnosis

1. Thyroglossal cyst is a vertically placed oval swelling whereas subhyoid bursitis is a transversely placed oval swelling.
   • Thyroglossal cyst moves on protrusion of the tongue outside (subhyoid bursitis does not).
2. Pretracheal lymph node swelling
3. Ectopic thyroid enlargement.