Reduction Cranioplasty in Macrocephaly and Its Surgical Technique

Abstract

Macrocephaly is a condition where the head circumference increases by more than 2 standard deviations above the normal size as per age. We present the case of a 9-year-old boy with macrocephaly due to arrested hydrocephalous. He had difficulty sitting up from a supine position and walking with a large head (62 cm). He has cosmetic disfigurement. Reduction cranioplasty was performed in two stages. There was a gross cosmetic improvement of craniofacial deformity with improvement in head holding after the second surgery. There is very limited literature describing the surgery and we have tried to describe in detail how we do it.

Keywords

macrocephaly - hydrocephalous - reduction cranioplasty

Introduction

Macrocephaly is described as an increase in head circumference by more than 2 standard deviations above the normal size as per age.[1] The cause described in the literature for this condition is hydrocephalous commonly. However, other causes like familial megalencephaly, Sotos syndrome, fragile X syndrome, Cowden syndrome, etc. are seen to be associated with macrocephaly.[2] The major problem associated with the disease is a large head with the inability to lift the head and mobilize. Selecting the proper candidate for this surgery is also important. The surgery aims to improve the life and quality of life of patients. Measurements of the skull bone are necessary before the reduction surgery. The most important parameter is the occipital frontal circumference (OFC).[3] The patient undergoing this surgery may undergo volumetric and craniometric measurements before getting operated; however, measuring OFC is considered to be the easiest and most economical method to calculate the skull circumference, which is an indirect indicator of the skull volume.[4]

Case Report

We present a case of a 9-year-old boy who presented with a large-sized head since birth with delayed gross milestones. He was the first child out of a nonconsanguineous marriage at term with normal vaginal delivery. He was diagnosed with occipital encephalocele at birth, which was operated on at the age of 3 months. He developed hydrocephalus after 1 month of the first surgery. He underwent a ventriculoperitoneal shunt twice, once on the left which was removed later due to a shunt block. It was followed by shunt placement on the right side. However, there was a gradual increase in the size of the head circumference to 62 cm ([Fig. 1A]). He was unable to lift his head or mobilize while getting up from bed due to his large head. Non-contrast computed tomography (CT) brain was done, which showed arrested hydrocephalous with ventriculoperitoneal shunt in situ ([Fig. 1B]). Stage 1 of reduction cranioplasty was planned under an elective setting, which involved the frontoparietal temporal bone. The second stage of occipitoparietal reduction was planned 1 year after the first surgery. He was operated under general anesthesia. He was placed in a supine position with his head in a neutral position and his body and head elevated 30 degrees. Bicoronal incision made 2 cm behind the coronal suture. The scalp flap was elevated. Craniotomy was done extending from the supraorbital ridge to 4 cm behind the coronal suture ([Fig. 1C]). Side to side from bitemporal extension (17 cm) ([Fig. 1D]).The dura was shrunk using bipolar cautery. In addition, 40 cc of cerebrospinal fluid (CSF) was drained from the frontal horn of the lateral ventricle to reduce the size of the brain parenchyma. The calvarium was reduced in the anterior–posterior dimension by 5 cm and reduced by 2 cm from side to side (total of 4 cm) ([Fig. 2A]). Cranioplasty was done with mini-plates and screws ([Fig. 2B]) followed by closure. The total duration of surgery was 3 and half hours with a blood loss of around 120 cc. The baby was extubated post-surgery and shifted to the recovery unit. He was observed for 24 hours and he was stable. He was then started on oral feeds the next day. The pre-op and immediate postoperative pictures showed a decrease in frontal bossing with a reduction in dimensions ([Fig. 2C]). The postoperative period was uneventful. Post-op X-ray skull was suggestive of stage 1 reduction cranioplasty ([Fig. 2D]). He was followed up recently after 12 months post-surgery, after which he was planned for the second stage of the surgery. The patient was positioned in a supine with head neutral position with head flexed leaving a two-finger gap between the chin and sternum. The incision was made on the previous incision with extension from the mid-point on the mid-sagittal plane till the inion. The scalp flaps were raised. The skull bone was removed till 1 cm anterior to the inion and laterally till the level of the previous surgery. The bony dimensions were reduced by 2 cm from both sides and 4 cm from behind. The dura is shrunk with bipolar cautery followed by CSF tap of 50 to 60 cc. The bony flaps are fixed with mini-plates, which is shown in A three-dimensional (3D) view of the calvarium post-op is shown in [Fig. 3]. Post-op recovery was uneventful. Sagittal view of non-contrast CT head with bone window showing the change in contour of the calvariumafter the stage 1 ([Fig. 4A]) and stage 2 surgery ([Fig. 4B]). Image of the CT scan of brain taken after the second stage surgery in the axial view is suggestive of reduction in the overall circumference with shunt in situ with mild hydrocephalous ([Fig. 4C]).The head circumference was reduced from 62 to 53 cm after the second stage surgery. There was an improvement in the quality of life of the patient (assessed using the World Health Organization Quality-of-Life Questionnaire). He was able to mobilize and sit on his own, and the cognitive factors have improved with better mental response with improvement of motor power from 3/5 to 4/5. He is now able to hold objects and eat and drink with his own hand. The comparative image of the patient before and after second stage surgery depicts cosmetic improvement in lateral and anterior-posterior dimensions ([Fig. 5]).

Fig. 1 (A) Large head with circumference of 62 cm. (B) Preoperative non-contrast CT brain in axial view showing moderate hydrocephalous VP shunt in situ. (C) Craniotomy was done extending from the supraorbital ridge to 4 cm behind the coronal suture. (D) The craniotomy was extended laterally on either side till just above the ear pinna (bitemporal extension) around 17 cm.

Fig. 2 (A) Segments removed 5 cm from anterior-posterior dimension and 2 cm each laterally from either side. (B) Cranioplasty using titanium mini-plate screws and plates. (C) Pre-op and immediate postoperative pictures showing a decrease in frontal bossing with a reduction in dimensions. (D) Post-op X-ray skull suggestive of stage 1 reduction cranioplasty.

Fig. 3 3D view of the calvarium post-op.

Fig. 4 (A) Sagittal view of non-contrast CT head with bone window showing the change in contour of the calvariumafter the stage 1. (B) Sagittal view of non-contrast CT head with bone window showing the change in contour of the calvarium stage 2 surgery. (C) CT scan of brain was done after the second-stage surgery in the axial view, suggestive of reduction in the overall circumference with shunt in situ with mild hydrocephalous. CT, computed tomography.

Fig. 5 Comparison of images between the patient before and after second stage surgery, depicting cosmetic improvement in lateral and anterior-posterior dimensions.

Technical Note

Reduction cranioplasty has not been widely described in the literature to date. Preoperatively, we did a CT brain with its bone window for comparison with the post-op period. We calculated the OFC of the patient. In stage 1, we planned to reduce the fronto-parietal-temporal dimensions (5 cm of anterior-posterior dimension was reduced after removing the calvarium). The lateral dimensions were reduced by 2 cm on either side. In the second stage, the bony dimensions were reduced by 2 cm from both sides and 4 cm from behind. Cranioplasty was done using mini-plates and screws, as shown in the post-op X-ray ([Fig. 4B]).

The intraoperative drainage of CSF was done to reduce the brain parenchyma volume and dura was also shrunk using bipolar cautery so that the reduced calvarium is easily accommodated and fixed without any tension. Secondly to prevent any subdural space which avoids development of subdural hygroma and also to decrease the space between calvarial bone and dura to prevent any extra dural collection.

Discussion

The head circumference was found to be the single most important predictor of the cranial volume in the growing phase of the child. The OFC measurement is considered to be the easiest and most economical method to calculate the skull circumference, which is an indirect indicator of the skull volume. The circumference of the skull OFC was 62 cm, which was decreased to 53 cm after two stages of surgery. The head size of a normal baby is around 35 to 36 cm at birth. There is a gradual increase in the size of the skull. Over the first 1 year, the size increases by 10 to 12 cm in circumference. In the next 1 to 5 years, the circumference increases by 5 to 6 cm. The increase in size of the head more than this results in macrocephaly, which is defined by an increase in head circumference by more than 2 standard deviations above the normal size as per age.[5] The growth in size is the result of an increase in CSF accumulation called hydrocephalous. It presents with impairment in the quality of life in the patient with difficulty in walking, standing, and sitting up from a lying down position. We have utilized reduction cranioplasty, which we follow in our institution. The most common that was found was Pi craniectomy.[6] The selection of patients for reduction cranioplasty is a task. It must improve the quality of life of the patient. The patient must be explained regarding the complications like venous rupture during the CSF drainage and sinus bleeds (more in occipital-parietal reduction surgery). If the reductive surgery is planned in two stages, the second stage has to be done after 1 year of completion of ossification from the first surgery. In our patient, it is planned for the next stage after 1 year if parents desire so and cosmesis is not good. The shunt is planned to be left in situ to prevent postoperative raised intracranial pressure. He will be kept under follow-up for long-term changes in the cranial volumetry.[7]

In 1999, two cases multi-stage reduction cranioplasty were reported, in which one patient underwent a four-stage operation and the other underwent a two-stage operation. The postoperative course of both patients was uneventful.[7]

In January 2022, an article was published describing two patients with congenital hydrocephalic macrocephaly who underwent shunting surgery followed by reduction cranioplasty at an early age using resorbable mini-plates.[8]

In 2019, an article was published describing macrocephaly, where the skull was reconstructed from a volumetric CT scan and a 3D volume was printed using a fused deposition modeling printer, which was used to simulate the cranioplasty using a total cranial vault remodeling technique. All the removed parts and augmenting cuts of the printed cranial vault were measured and transferred to the patient's skull to replicate the plan.[9]

Limitations of reduction cranioplasty include the inability to modify the anteroposterior and lateral diameters of the skull base and failure to shorten the superior sagittal sinus. The shunt in our case was placed at the age of 4 months; however, the first shunt got blocked, which was evident due to the gradual increase in size of the head. The shunt was revised and placed on the opposite side; however, there was inadequate drainage of CSF for reasons unknown, in spite of a functioning shunt, and the skull circumference kept on increasing.[10] [11] [12] Reduction cranioplasty should be avoided before 3 years of age as infants with severe hydrocephalus and huge macrocephaly undergo CSF diversion at such a young age that it can cause major cranial deformity due to CSF over-drainage. Virtual surgical planning is now a new useful adjunct for skull and craniofacial surgery, allowing for an improved precision, efficacy, and aesthetics.[4] [13]

Conclusion

The head circumference was found to be the single most important predictor of the cranial volume in the growing phase of a child. The OFC measurement is considered to be the easiest and most economical method to calculate the skull circumference, which is an indirect indicator of the skull volume. The circumference of the skull OFC, in our case, was 62 cm, which was decreased to 53 cm after two stages of surgery.

Case Highlights

• We present a 9-year-old boy with macrocephaly (62 cm) due to arrested hydrocephalus.

• There is very limited literature describing the surgery and we have tried to describe in detail how we do it.

• He was planned electively for reduction cranioplasty in two stages and there was a gross cosmetic improvement of the craniofacial deformity with improvement in head holding and mobilization in the patient as well as an improvement in quality of life.

• The head circumference was reduced from 62 to 53 cm after the second stage of surgery.

Conflicts of Interest

None declared.

Authors' Contribution

All authors contributed to the study's conception and design. A.A.: conceptualization and first draft; A.K.M.: figure preparation; S.P.: editing; R.C.D.: manuscript writing; R.L.S.: review of literature; S.B.S.: contributed Discussion and Conclusion sections.

• References

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• 2 Winden KD, Yuskaitis CJ, Poduri A. Megalencephaly and macrocephaly. Semin Neurol 2015; 35 (03) 277-287
• 3 Grummer-Strawn LM, Reinold C, Krebs NF. Centers for Disease Control and Prevention (CDC). Use of World Health Organization and CDC growth charts for children aged 0-59 months in the United States. MMWR Recomm Rep 2010; 59 (RR-9): 1-15
• 4 Martini M, Klausing A, Lüchters G, Heim N, Messing-Jünger M. Head circumference - a useful single parameter for skull volume development in cranial growth analysis?. Head Face Med 2018; 14 (01) 3
• 5 Weaver DD, Christian JC. Familial variation of head size and adjustment for parental head circumference. J Pediatr 1980; 96 (06) 990-994
• 6 Abuzayed B, Alawneh K, Qawasmeh MAL, Raffee L. Modified bilateral Pi craniectomy technique for reduction cranioplasty: novel technique. J Craniofac Surg 2019; 30 (08) 2593-2596
• 7 Takahashi Y, Tajima Y, Okura A, Tokutomi T, Shigemori M, Kiyokawa K. Reduction cranioplasty for macrocephaly. Two case reports. Neurol Med Chir (Tokyo) 1999; 39 (06) 459-462
• 8 Asadov RN, Sanakoeva AV, Golovanev PS, Prityko AG. Reduction cranioplasty for hydrocephalic macrocephaly: clinical observations and literature review [in Russian]. Zh Vopr Neirokhir Im N N Burdenko 2022; 86 (01) 91-95
• 9 Teixeira WR, Campos AR, Bartikian M, Faria CC, Lucas-Neto L, Santos MM. Reduction cranioplasty using a three-dimensional preoperative virtual model for treatment of extreme macrocephaly and positional plagiocephaly secondary to untreated hydrocephalus - case description and literature review. Neurosurgery 2019; 66 (Supp 1): 310-451
• 10 Sundine MJ, Wirth GA, Brenner KA. et al. Cranial vault reduction cranioplasty in children with hydrocephalic macrocephaly. J Craniofac Surg 2006; 17 (04) 645-655
• 11 Gage EA, Price AV, Swift DM, Sacco DJ, Fearon JA. Limited reduction cranioplasty for the treatment of hydrocephalic macrocephaly. Plast Reconstr Surg 2011; 128 (06) 1272-1280
• 12 Iyer RR, Carey CM, Rottgers SA. et al. Early postnatal cranial vault reduction and fixation surgery for severe hydrocephalic macrocephaly. J Neurosurg Pediatr 2018; 21 (05) 486-495
• 13 Iyer RR, Carey CM, Rottgers SA. et al. Early postnatal cranial vault reduction and fixation surgery for severe hydrocephalic macrocephaly. J Neurosurg Pediatr 2018; 21 (05) 486-495

Publication History

Article published online:
10 June 2025