IIIB1d - Durotomy

Question 1

What are the indications for a durotomy?

Answer 1

Treatment of intradural diseases of the spinal cord or brain (intradural extramedullary, intramedullary or intra-axia)

Examples:
* Tumors
* Hematoma
* VP shunt
* SAD marsupialization
* FMD-C1
* DP- dogs at risk for PMM

Question 2

What shaped cuts should be made if the intention is to marsupialize a durotomy after opening?

Answer 2

The durotomy should be cut in a capital ‘i’ shape to allow it to flap open

Font on these cards makes capital I just a line

Question 3

What kind of suture is appropriate for tying the corners of a durotomy open for the purpose of marsupialization?

Answer 3

5-0 absorbable monofilament

Silk is sometimes mentioned but it is non-absorbable?

Question 4

What should be used to cover the durotomy before closure?

What is the most common type used?

Answer 4

A biologic or synthetic dural substitute

The most common is Porcine Small Intestinal Submucosa (SIS)

Question 5

What four procedure specific complications may be associated with a durotomy?

Answer 5

1) CSF leakage (not likely of clinical significant in vet species)
2) Infection (opening the dura increases the risk of exposure of the CNS to bacteria or fungi
3) Pseudomeningocele (CSF can fill into a defect in the closure and compress the cord)
4) Dural to spinal cord adhesions

Plus standard risks of nerve damage, hemorrhage, etc

Question 6

What type of scalpel blade should be used to open the dura and how should it be angled?

Answer 6

A #12 scalpal blade angled awat from the spinal cord

A bent needle or dental scyth can also be used

Question 7

What is the the purpose of a durotomy for dogs who are deep pain negative?

Answer 7

There may be a relationship between durotomy and a decreased incidence of progressive myelomalacia

• 5-site mini-hemi + durotomy saw only 4% incidence of PMM
• Single site hemi + durotomy vs hemi alone had 0% PMM in the durotomy group compared to 22% in the non-durotomy group