Türk Plast Cer Derg (1993) Cilt:l, Sayı:2
CRANIAL VAULT RECONSTRUCTION FOR FRONTO-ORBITAL FIBROUS DYSPLASIA USING
SPLIT-CALVARIAL BONE
Emin M AVİLİ* *, Yücel ERK*, Kemal BENLİ**
*PIastic & Reconstructive Surgery, Hacettepe University, Faculty of Medicine, Ankara.
**Neurosurgery, Hacettepe University, Faculty of Medicine, Ankara.
SU M M A R Y
Fronto-orbital fibrous dysplasia is a progressive disease which may cau.se frontal protuberance, orbital dystopia and occasionally neural entrapment disorders. Resection o f the îumor both corrects the deformity and avoids complications due to cotnpression. We treated a patient with frorüo-orbital fibrous dysplasia which extended into anterior cranial base.
Resection o f the tumor was foltowed by reconsîruction with split-calvarial grafis, Reconstruction was completed in a total cranial vault reconstruction fashion. The dead space which w as observed in place o f the tumor site disappeared by the 6ih month afler the operation. Preoperative 10 mm vertical left dystopia o f the patient was corrected to 4mm dystopia posîo- peratively. Diplopia which developed as a result o f dystopia correction p ersisted fo r 2 months and gradually disappeared by the end o f4 th month Clinical examination and M RI evalu- ation o f the patient postoperatively demonstrated that the use o f split-calvarial grafis fo r this purpose, provide the surgeon a material with low resorption tendency, easy to manipulate and fit the natural structure o f the region.
Key Words : Fibrous Dysplasia-Bone Grafis-Cranium Re
construction.
Fibrous dysplasia is a nonmalignant tumor in which undifferentiated mesenchymal bone-forming cells pro- liferate and replaces normal bone. The bones most com- monly involved are the frontal, sphenoid, ethmoid and maxilla [1, 2]. It may be monoostoic or polyostoic; the latter may be part of the Albright syndrome [3]. The dis- order is usually noticed in adolescence. If the tumor is located on the cranio-orbital area it can cause displace- ment of the globe, diminution of visual acuity and in some cases blindness [4]. Blindness is the result of com- pression of the optic nerve by optic canal ınvolvement [5]. In the past conservative management or radiation treataıent w as advocated. Follow up studies of the pa- tients who had received radiation treatment demonstrat
ed that the incidence o f malignant transformation is higher in those who had received previous irradiation treatment [6, 7]. Today surgical treatment is advocated for cosmetic and functional reasons. The concept of to
tal excision and immediate reconstruction is the treat
ment of choice for most of the surgeons dealing with
Ö ZE T
FRO N TO -O RBİTAL D İSP L A ZİD E "SFLİT K ALVAR-
Y E L " KEM İK G R EF T LE R İ İL E K R A N İU M REKONS- TRÜKSÎYONV
Fronto-orbital bölgede yerleşim gösteren fibröz displazi fron
tal kabarıklık, orbitanın yer değiştirmesi ve optik sinirin sıkış
ması gibi bozukluklara yol uçabilen ilerleyici bir hastalıktır.
Tümörün çıkartılması şekil bozukluğunu düzelteceği gibi bası
ya bağlı komplikasyonları da önler. Kliniğimizde ön kafa ta
banına kadar uzanım bir fronto-orbital displazi olgusu tedavi edilmiştir. Tümörün çıkarılmasından sonra oluşan defekt kal- variumdan alınan tanjensiyel olarak ikiye ayrılmış kemik grefileri ile onarılmıştır. Tümörün çıkarılması ve kranium re- konstrüks iyonundan sonra tümör yerinde oluşan ölü boşluk ameliyattan sonraki 6. ayda kaybolmuştur. Ameliyat öncesi aşağı doğru 10 mm olarak ölçülen orbita yer değiştirmesi ameliyat sonrası 4 mm'ye inmiştir. Orbitanın normal lokali- zasyonuna doğru yer değiştirmesi sonucu ortaya çıkan diplopi 2 ay devam etmiş 4. ayın sonuna doğru da tamamen kaybol
muştur, Ameliyat sonrası devrede hastanın muayenesi ve MRI ile değerlendirilmesi sonucu "split-kalvaryel" greftlerin, az re- sorbsiyona uğrayan, kolay şekillendirilen ve bölgenin anato
mik yapısına kolayca uyan kemik grefileri olduğu gösterilmiş
tir.
this tumor [2, 8, 9].
CASE REPORT
In June 1992 a 17-year-old male patient w as re- ferred to our department with orbital dystopia due to a mass in left side of the frontal bone (Fig. 1). He present- ed a painless swelling which progressed gradually in the last three years. There were no visual disturbances or neural defıcits. The vertical orbital dystopia measured on the AP cephalogram w as 10 mm. The coronal and sagital sections of MRO demonstrated a hypodense mass located on the upper and upper medial wall of left orbit occupying the left side of the anterior fossa and ex- tending superiorly and laterally. The mass contained some areas in the çenter The ou ter surface of the mass was explored through a coronal incision and subperios- teal dissection. The İnvolved bone w as easily recog- nized because of its more vascular appearance. The mass to be removed was marked with surgical ink. Ther an access providing osteotomy w as performed on the
FEBROUS DYSPLASIA
rigbt parietal bone. The mass was removed with the use of rongeurs since the thickness of the frontal bone had reached 5-6 cm especially on the middle of the mass.
The left half of the frontal bone, left orbital roof and cra- niai base involved witb the tuınor were removed. The eye globe and left frontal lobe was decompressed. Af ter removal of diseased bone we were faced with a cranium defect measuring 14x12 cm. The bone which we re
moved for access providing osteotomy and another bone graft ffom the left parietal region were divided into two tangentially. The inner table of split cranial grafts were used for the reconstruction of donor sites. The outer tables were used to reconstruct the defect, which ap- peared after the removal of the mass.
Orbital roof, left half of the frontal region and parts of temporal and parietal regions were ali reconstructed with split-calvarial bone grafts. The bones were secured to each other and to the cranium with 000 stainless Steel wire material (Figns. 2, 3, 4,)
RESULT
The patient was discharged from the pospital on the lOth P.O. day. He complained from diplopia after the operation which was not present preoperatively. There was some descent the diplopia, as expressed by the pa
tient, but he didn’t have a normal binocular Vision by the end of 6th month. The vertical dystopia which was 10 mm before the operation was 6 mm after the operation as measured with PA cephalogram. The convexity and smoothness of the franto-orbital region was natural after the operative edema subsided (Fig. 5). Clİnical evalua- tion, cephalograms and MRI showed no signs of resorp- tion both in the early and late postoperative period. Left half of the frontal lobe progressed in to the space which resulted after the excision of the mass, by the 6th P.O.
month (Figs. 6,7).
DISCUSSION
There are two goals in surgical treatment of patients with fronto-orbital fibrous dysplasia; functional and cos- metic. Radical resection is the treatment of choice advo- cated by most of the authors dealing with this tumor, since the incidence of malignant transformation is re- ported to be % 1 and previous radiation treatment in- creases the risk of malignant transformation [2,8,9]. Re
section of the tumor reduces the incidence of recurrence, possibility of malignant transformation and avoids com- plications due to compression of vital structures. We re- sected most of the tumor and decompressed eye and frontal lobe, but it was not possible to remove ali of the involved cranial base and orbital roof. In correlation
with our case some authors in the literatüre also report that İt is not always possible to remove ali of the mass extending to cranial base and this residual tumor is not always a potential source of recurrence after adoles- cence [5, 8, 9, 10, 11]. Diplopia, caused by sudden eye displacement is an unpleasant but unavoidable compli- cation of this operation. The patient was infonned of this complication before the operation and he and his parents preferred radical excİsion of the tumor rather than to have a contour restoration by removing some frontal bone. Although there are almost no disagreement conceming the necessity of resection of the tumor, in fi
brous dysplasia there areseveral methods of reconstruc
tion recommended for the resultant defect. Feiring used a stell plate [12]. Munro advocated the use of rib grafts utilizing the chaing-link fence principle for rigid fixa- tion of the grafts [8]. Jackson reported the use of split cranial bone grafts for reconstruction of temporal re
gion, orbital roof and lateral orbital wall and split rib grafts for reconstruction of orbital and frontal region [13]. In our case, ali resultant defects which appeared after radical resection of the tumor were reconstructed with the use of split-calvarial grafts. Although Jackson reports smooth frontal and orbital surfaces with the use of rib grafts in conjunction with bone dust beetween grafts, our experience with enchondral bone grafts İn this area resulted with a high degree of resorption and consequent deformity, most of the time. The use of total cranial vault reconstruction technique in thes case pro- vided us some advantages. First, the mass can be more easily and extensively resected through a wider expo- sure. Second; split calvarial bone grafts are obtained more easily when cranial bones removed from their ana- tomic sites.
Third; if there are any distortion of the cranial bones, due to mass effect, they may be corrected with this technique.
Other reasons for total cranial reconstruction with split-calvarial grafts are; that they fit the natural convex- ity of fronto-orbital region more properly and do not ne- cessitate bone grafts from donor sites other than the op
eration area. The use of split-calvarial grafts ali över the reconstruction procedure provided us a smooth frontal and periorbital surface with natural convexity. The split- calvarial grafts showed no sign of resorption in the fol- low-up period.
M. Emin MAVİLİ, M.D.
Paris Caddesi, No: 60/7 Kavaklıdere-ANKARA 06540
Türk Plast Cer Derg (1993) Cilt:l, Sayı:2
Figüre 1. Preope rative appearan.ce. o f the patient.
Figüre 2. Expos ure o f the mass in subperiosteal plane.
FTBROUS DYSPLASIA
Figüre 3. Appearance o fth e patient after removal o fth e mass and cranial bones.
Figüre 4. The defects are reconstructed with split calvarial bones.
1S7
Türk Plast Cer Derg (1993) Cilt: 1, Sayı:2
Figüre 5. Appearance ofthe patient A) Before the operation, B) After the operatiort
FffiROUS DYSPLASIA
Figüre 6. Coronal MRI sections A) Preoperative B) 2 wecks after t he operation, C) 6 months after the operation.
Türk Plast Cer Derg (1993) Cüfcl, Sayı:2
Figüre 7. Sagital M RIsections A) Preoperative B) 2 weeks after the operatiort, C) 6 months afler the operation.
FİBROUS DYSPLASIA
REFERENCES
1. Sassin, J.F. and Rosenberg, R.N. Neurological complica- tions of fibrous dysplasia of the skull. Arch. Neurol.
18:363, 1968.
2. Edgerton, M.T,, pershing, J.A., and Jane, J.A. The surgi- cal treatment of fibrous dysplasia. Ann. Surg. 202:439, 1985.
3. Albright, F., Butler, A. M., Hampton, A.O. and S mi Ih, P.
Syndrome characterized by osteitis fibrosa disseminata, areas of pignıentaüon and endocrine dysfunction, with precocious puberty in females: Report of fıve cases. N.
Eng. î. Med. 216:727, 1937.
4. Chen, Y.R., and Fairhoim, D. Fronto-orbito-sphenoidal fibrous dysplasia. Ann. Plast. Surg. 15:90, 185.
5. Gass, J.D. Orbital and ocular involvement in fibrous dys
plasia. South. Med. J. 58:324,1965.
6. Schwartz, D.T., and Alpert, M. The malignant transfor- mation of fibrous dysplasia. Am. J. Med, Scİ. 247:1, 1964.
7. Gross, W., and Montgomery, W.W. Gibrous dysplasia and malignant degeneration. Arch. Otolaryngol. 85:653, 1967.
8. Munro, I.R., Chir, B., and Chen, Y.R. Radical treatment for fronto-orbital fibrous dysplasia: the chain-link fence.
Plast. Reconstr. Surg. 67:719,1981.
9. Jackson, I.T., Hide, T.A.H., Gomuvvka, P.K. Treatment of cranioorbital fibrous dysplasia. J. Maxillofac. Surg.
10:138,1982.
10. Stamm, C. Fibrous dysplasia of facial bones. Arch Otola
ryngol 64:293,1956.
11. Chen, Y.R., and Noordhoff, M.S. Treatment of facial fi
brous dysplasia: How early and how extensive? Plast. Re
constr. Surg 86:835,1990.
12. Feiring, W., Feiring, E.H., and Davidoff, L. M. Fibrous dysplasia of the skull. J. Neurosurg. 8:377, 1951.
13. Jackson, İT. Tumors of the craniofacial skeleton, includ- ing the jaws. In: McCarthy: Plastic Surgery. Saunders, Philadelphia 1990,3336-3411.
