Short Notes in Plastic Surgery

July 31, 2012

27. Basic Principles in the Surgical Treatment of Craniofacial Anomalies (CFA)

Filed under: Chapter 27 — ravinthatte @ 5:05 am

27. Basic Principles in the Surgical Treatment of Craniofacial Anomalies (CFA)

1.  A vast majority of deformities because of CFA are skeletal and soft tissues are secondarily affected.

2.  There are exceptions to the above for e.g. Treacher-Collins Syndrome in which mid face hypoplasia exists both in the skeleton as well as the soft tissues of the face (Fig. 1) or in hemifacial microsomia (see photograph chapter 24) where bony and soft tissue deficiencies co-exist. Both conditions will be dealt with in separate sections.

Fig. 1: Photograph shows classic features of the Treacher Collins Syndrome with both skeletal and soft tissue abnormalities of the mid-face. Will be discussed separately in another chapter.

3.  Apropos 1 (above) surgical work involves movement of the skeleton, the principles of which were founded and settled by Paul Tessier (see biographical sketch at the end of the chapter). Tessier showed:

  • That a combined intra and extra cranial approach significantly improves the ability to osteotomise bones precisely and therefore improves the results
  • Osteotomised cranial bones even when removed subperiosteally can be manipulated in vitro by way of benchwork (Fig. 2) and then can be replaced in their new positions and will yet survive if placed within vascularised tissue (the dura inside and the galea and the scalp flap outside).

Fig. 2: A part of the skull removed and is being cut with a power driven instrument which will allow manual moulding to alter its shape.

4.  The age at which surgery should be undertaken will depend upon when the patient first comes for treatment but when the deformity is recognized early, the ideal age at which to operate is about around six months to a year (the earlier the better) because bones are soft and can be moulded by hands or can be “green stick fractured”. As age advances, an osteotomy with a forceps or a power driven saw might need to be used (Fig. 2). However the treatment of hypertelorism by whatever cause is postponed till two years of age (please see next chapter).

5.  When a bone flap is removed only for access for e.g. in hypertelorism (Fig. 3), a craniotomy is said to be performed. When a bone flap is removed, for e.g. in brachycephaly, and then put back in a new position and a defect is left behind, a craniectomy is said to be performed (Fig. 4). For more extensive defects, when the whole of the calvarium is osteotomised and manipulated, and allowed to lie in a new position the term used for the procedure is calvariectomy (Fig. 5).

Fig. 3: Multilpe arrows show the grooved area under the dura which contains the superior sagittal sinus. Flaps have been raised and a craniotomy has been performed for treatment of hypertelorism.

Fig. 4: Example of a craniectomy with advancement. The advanced bone flap has been sutured to the supra-orbital bar with synthetic long duration sutures devoid of any local or systemic side effects. Arrow shows a biodegradable plate. See point 8.

Fig. 5: Almost the whole of the calvarium has been osteotomised and refashioned in a case of sagittal stenosis which had lead to a very long skull (Scaphocephaly). This procedure is usually denoted by the name calveriectomy. Plagiocephaly will be dealt with in a separate section.

6.  For any procedure on the calvarium, the superior sagittal venous sinus enclosed between two layers of the dura which runs in a mid line from the front to the back must always be kept safe lest torrential and life threatening bleeding might be caused (Fig. 3).

7.  Surgical approach: Incisions are planned according to the condition being treated. For surgical work in the anterior half (bicoronal stenosis, anterior brachycephaly, plagiocephaly due to uni-coronal stenosis and hypertelorism) a transverse incision well behind the coronal suture (site) is now a standard choice. This allows adequate redrapingover the newly arranged skeleton. The incision is taken in a zig-zag manner (Fig. 6)  to prevent a linear scarred depression after healing. The flap while being raised is kept above the level of the epicranium (Galea) up to the supraorbital ridges and is then deepened below the epicranium so that when the orbits are approached a circumferential subperiosteal dissection can be undertaken to eviscerate the eyeball which will then hang only on the optic nerve as the orbital osteotomies are performed (Fig. 8). The supra trochlear and supra orbital vessels are preserved. Over the vault the epicranial flap is raised separately (also called the Galeal flap) and is based on the vascular network of the temporal vessels (Fig. 7). More often than not the temporalis muscle is raised from its fan shaped attachment subperiosteally for better access to the lateral part of the temporal bone to facilitate osteotomies of the orbits in that area. Separate temporal fascia flaps can also be raised for the same purpose for which gaeleal flaps are used (Fig. 7).

Fig. 6

Fig. 7: Picture above shows a scalp flap with a separate peri-cranial or a gaeleal flap. The picture below shows a temporal fascia flap.

Fig. 8: After the scalp flap is raised beyond the supra-orbital ridges the eyeballs are almost completely eviscerated and hang on the optic nerve. The supra-orbital and supra-trochlear vessels have been skeletonised by small osteotomies around their foramena and the inferior dissection has been done by a trans-conjunctival approach. The lacrimal apparatus has been saved and left in situ.

8.  When bone or bones are moved to their appropriate place the methods to secure their new positions have evolved over the years for e.g. sliding osteotomies (Fig. 9), steel wires, wires made of improved alloys have given way to plates and screws made of materials which are biologically non-corrosive locally or systemically neutral (Fig. 10, 11), to now biodegradable materials with adequate strength, malleability and enough durability to serve their purpose (Fig. 4, 12). Generally speaking because bone grows back rapidly in children, the measures used for fixation have to be more reliable in them lest the deformity creep back through rapid neo-osteogenesis. In the event distraction osteogenesis after suitable osteotomies is also employed (Fig. 13).

Fig. 9: Intraoperative picture shows a sliding osteotomy with an intervening bone graft to keep the osteotomy in place as per line drawings centre and right.

Fig. 10: Modern non-reactive plates and screws mounted on a dry skull. These are cheaper than the bio-degradable plates.

Fig. 11: A similar smaller plate has been used for the frontozygomatic area.

Fig. 12: Bio-absorbable screws and plate mounted on a dry skull for demonstration.

Fig. 13: A case of mid-facial hypoplasia being treated with low distraction.

9.  While the treatment of each individual anomaly will be covered in short sections later, the following facts need to be noted:

  • Posterior (occipital) or lateral temporoparietal plagiocephaly must be carefully investigated to find out if the deformity is in fact sutural in origin or only deformational. The latter can be treated with external appliances for e.g. custom made helmets or by nursing children in suitable positions.
  • Non-syndromic purely cranial sutural abnormalities have a much better long term prognosis.
  • Syndromic sutural stenoses are more difficult to treat and have poorer long term results because the tissues involved may be dysgenetic and their long term growth may not be satisfactory.
  • Pan sutural abnormalities (perisphenoidal) in the cranial base are the most difficult to treat because it is well nigh impossible to surgically manipulate the sphenoid which in addition is a major port of entry or exit for numerous major vital vessels and nerves.
  • Microcephaly which results from lack of development of the brain is not treated surgically.

The text of this chapter was compiled and arranged by Ravin Thatte and was heavily contributed to by Nitin Mokal who also provided illustrations and photographs from his practice.

Paul Tessier (1917-2008)

Paul Tessier, the French surgeon is considered the father of Craniofacial Surgery. His long career has seen him donning various caps including maxillofacial surgery, cleft surgery and pediatric surgery and in his early years he even treated cases of Dupuytren’s contracture of the hand. Thus a surgeon who began as a generalist carved out the super specialty of Craniofacial Surgery. However at heart he was an anatomist; a subject he studied as in a penance and he often went on internal pilgrimages to find a solution to the difficult problems in the area of the craniofacial skeleton His solution to Hypertelorism came out of this pilgrimage.

Anecdotally it is reminisced that Paul Tessier once asked his neurosurgeon if a combined intra and sub cranial approach to solve the vexed problem of Hypertelorism was practical. The neurosurgeon is believed to have responded with ‘Pourquoi Pas?’ (Why Not?) and thus arose the super specialty of craniofacial surgery.

As with most geniuses, he was reluctant to form an association of his specialty and it was with some cajoling that he finally accepted to become its first president.

Many senior stalwarts of craniofacial surgery all over the world owe their practice of this specialty to Paul Tessier. Some worked and trained with him. Others emulated and practiced the principles that he founded.

By Jyotsna Murthy (from Chennai) and Sharmila Kher (from Mumbai).

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