Maxillo-facial surgery :: Plastics

Plastics of post-operative defects of Os Frontale by means of a prefabricated duracrylic plate on a plaster model of the face - clinical report.
/ Second jubilee scientific-practical conference of TNTM on the occasion of the 1300th anniversary of the founding of the Bulgarian state /

DISTRICT HOSPITAL - SLIVEN
NEUROSURGICAL DEPARTMENT
DR. HRISTO HRISTOV

In neurosurgery, there are the following indications for plastic restoration of skull defects:
1. Prophylactic - we aim to avoid rough scars
2. Therapeutic - for the treatment of traumatic epilepsy
3. Cosmetic - especially in cases of temporo-frontal or fronto-orbital defect, the aim is its aesthetic restoration.
These defects are the boundary between neurosurgery and maxillofacial surgery.
The methods known so far for plastic restoration of postoperative defects of the skull bones with plexiglass, tantalum, etc. cannot be successfully applied in the cases of these defects, due to the difficult technology of manufacturing the replacement plate.
N. Kyuchyukov's method from 1963 with "Durakril", which almost completely replaced these classical methods, has the following disadvantages:


1. We make the Duracrylic lamella during the operation directly on the brain. The plastic self-polymerizes and a free monomer remains in it, which has a toxic effect.
2. The surgeon makes only one lamella and if he accidentally drops it on the floor, we must it sterilize, which wastes unnecessary time during the operation - therefore the method is uncertain.
3. The polymerization technology itself is the formation of the lamella requires a certain time / about 50 minutes /, during which time the patient is under anesthesia and we not operate on.
4. Impossibility for aesthetic shaping / creation of convexity and concavity / of the surfaces in symmetry with the opposite half.
This report concerns one of our clinical cases with a significant temporo-frontal bone defect, in which we apply a more rational approach to post-operative plastic reconstruction - a prefabricated replacement lamella of Duracrylic on a gypsum model of the patient's face.
We will present to your attention the treatment method and the results achieved through it on the following clinical case:

History of the disease № 20319 from 10.11.to 25.11.1980 I.D.I. Samuilovo village, driver.
Diagnosis: Status post fractures of the cranium and contusion of the brain

From the status: Man of visible age about 40 years, in good general condition. Heart and lungs - b.o. RR- 130/80. On the forehead on the right, we can see a post-operative defect measuring approximately 8 x 4 cm with an irregular shape / Figures 1, 2, 3 and 4/.

 Fig.1 - Fronto-orbital defect 6 months after life-saving surgery   
 Fig.2 -  The same defect from another  angle. In the both photos we can clearly see the indentation in the  affected area     
 Fig.3 - Profile diagram from an X-ray, on which we can see the defect of the skull in the fronto-orbital area
 Fig.4 -  “An fas" scheme of the same defect

Description of the technique and technology of making the lamella:

Taking a plaster impression of the patient's face / face mask /

We smeared the patient's face with Vaseline. We put 2 tubes in the lower nasal passage, respectively on the left and on the right, and around them we tamponade with cotton. We put gauze on 2 floors on the eyebrows and on one floor on the patient's eyelashes. Mix gypsum slurry in bulk and apply with a spatula on the face. As the cast hardens, the patient breathes through the tubes, and the gauze prevents the hairy parts from sticking to the cast. After hardening, we remove the imprint thus obtained from the patient's face /Fig.5/.

Casting of a working gypsum model



Fig.5 Gypsum model from a face mask on which the duracrylic lamella will be modeled and cast

Making the "duracrylic" lamella itself

We mix "Duracryl" / powder and liquid, resp. polymer and monomer / by bulk sample. We wait for the initial period of polymerization and with the thus obtained "dough“, we fill the gypsum box of the model. We model the protrusion of the future lamella with cotton soaked in monomer. Irrigate with warm water to accelerate the polymerization process. Then with a cutter with a dental drill, we clean the lamella from the excess plastic and perforate with a drill. In this way, we make 2 lamellas - 1 working and 1 spare, which we sterilize by boiling. Note: The lamellas can be made of colorless "Duracryl" to avoid a possible allergic reaction to the dye, often in practice / Fig. 6 and 7/.


Fig.6 - The gypsum model with the finished lamella   
Fig.7 - The lamella at an angle showing its convexity and concavity

We perform the operation according to the classic method with a leather lambo after an incision in the hairy part of the head and then we fix the lamella after minor adjustments by sewing with silk thread through special bone holes and their corresponding holes in the lamella. ... Fig. 8, 9 and 10.



Fig.8 - The patient immediately after surgery. The large skin lambo in the hairy part allows access to the defect and does not leave scars     
Fig.9 - The patient in profile
Fig.10 - The patient 12 days after the operation when we removed the sutures

The proposed method has the following advantages:
1. We avoid the toxic effect of the plastic monomer on the underlying soft tissues, because we boil the lamellae, whereby the excess monomer takes off.
2. The method is safe because it is possible to make a spare plate.
3. This method does not shorten the time for making the lamella, but it happens before the operation, which shortens the time for surgical intervention.
4. The method offers great opportunities for cosmetic shaping of the lamella, as we work on a model before surgery, without mental strain and under visual control of the opposite facial half.
Not all this is possible in the conditions of an operative intervention.

Conclusions

1. The method is safe, secure, with cosmetic value and prevents traumatic epilepsy.
2. We can apply it to close defects in other anatomical areas of the skull, even more easily when taking a plaster impression.
3. The technique and technology of making the lamella is light and with accessible materials.

For more details write to pfhristov@yahoo.com

 

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