DAVID F. JIMENEZ, M.D., F.A.C.S., AND CONSTANCE M. BARONE, M.D., F.A.C.S.

Transcription

1 Neurosurg Focus 9 (3):E2, 2000 Endoscopy-assisted wide-vertex craniectomy, "barrel-stave" osteotomies, and postoperative helmet molding therapy in the early management of sagittal suture craniosynostosis DAVID F. JIMENEZ, M.D., F.A.C.S., AND CONSTANCE M. BARONE, M.D., F.A.C.S. Center for Craniofacial Disorders, University of Missouri Columbia Health Sciences Center, Columbia, Missouri Object. The purpose of this study was to assess the efficacy, safety, associated complications, and outcome in patients with sagittal suture craniosynostosis in whom endoscopy-assisted wide-vertex craniotomy and "barrelstave" osteotomy were performed. Methods. During a 4-year period, 59 patients with sagittal suture synostosis underwent endoscopy-assisted wide-vertex craniectomies, barrel stave like osteotomies, and postoperatively were fitted with custom-made molding helmets. Data on operative time, blood loss, transfusion rates, hospital length of stay, complications, and hospital charges were collected prospectively. The mean patient age at the time of surgery was 3.7 months. The average blood loss was 31.8 ml; and only one patient required an intraoperative blood transfusion. Nine patients received transfusions of donor blood postoperatively. The mean operative time was 50 minutes, and all but three patients were discharged from the hospital the morning following surgery. There were no intraoperative complications. Normocephaly as well as normal cephalic indices were observed at latest follow up. Conclusions. The authors conclude that early treatment of infants with sagittal suture craniosynostosis by using minimally invasive, endoscopy-assisted wide-vertex craniectomies provides excellent results and a significantly lower morbidity rate than traditional calvarial vault reconstructive procedures. KEY WORDS sagittal suture craniosynostosis endoscopy craniectomy osteotomy The purpose of the study was to assess the efficacy, safety, associated complications, and results in the treatment of patients with sagittal suture craniosynostosis by performing endoscopy-assisted wide-strip vertex craniectomies of the sagittal suture in addition to bitemporal and biparietal "barrel-stave" osteotomies. Postoperatively, all patients were fitted with custom-made cranial molding helmets to achieve and maintain normocephaly. The aim of this procedure was to reduce morbidity, operative time, blood loss, blood transfusion rates, hospital length of stay, cost, and concurrently to obtain satisfactory or superior surgical results compared with conventional therapies. We first introduced this technique several years ago, and in the present report we discuss the technique and provide follow-up findings. 20 CLINICAL MATERIAL AND METHODS Patient Population Fifty-nine consecutive children who presented with sagittal suture craniosynostosis were treated during a Abbreviations used in this paper: AP = anteroposterior; CI = cephalic index; CVR = cranial vault remodeling. 4-year period (May 1999 July 2000). All patients underwent endoscopy-assisted wide-vertex craniectomies of the sagittal suture, as well as biparietal and bitemporal "barrel-stave" osteotomies. Postoperatively the patients were fitted with custom-made surlyn molding helmets, which they wore for up to 12 months of age. Cephalic indices were measured in all patients preoperatively and at every postoperative follow-up visit. Using cranial anthropometric spreading calipers the euryon-to-euryon (greatest cranial width) and glabella-to-opisthocranium (greatest anterior posterior distance) measurements were obtained. Dividing the former by the latter and multiplying the sum by 100, an index of cranial proportionality (CI) was obtained. The patients CIs were measured and compared with established normal values obtained in age-matched individuals. There were 49 male (83%) and 10 female (17%) patients. Age at the time of surgery ranged from 2 weeks to 9.5 months (mean 3.7 months) (Fig. 1). The mean preoperative weight was 6.3 kg (range kg). Preoperative hematocrit levels measured in all patients ranged from 22 to 57.9% (mean 32.9%). Estimated blood volume of the patients ranged from 624 to 752 ml (mean ml). The follow-up periods ranged from 1 to 50 months (mean 15.3 months). In the 1st postoperative year, the patients attended a monthly or bimonthly follow-up Neurosurg. Focus / Volume 9 / September,

2 D. F. Jimenez and C. M. Barone Fig. 1. Bar graph showing distribution of patient age. visit in which CI measurements and photographs were obtained, and helmet adjustments were made. Thereafter, the patients were followed on a yearly basis. Surgical Procedure After induction of sevoflurane, a single 22-gauge intravenous line was placed. Nondepolarizing neuromuscular blockade was obtained by administrating a 0.3-mg/kg dose of cisatracurium besylate. Fentanyl was given at 1 to 2 g/kg in addition to a Tylenol (40 mg/kg) suppository for pain control. General anesthesia was maintained with continuous induction of sevoflurane. The patients were placed in the modified prone position on a heated and padded pediatric bean- bag. A heating unit was used to maintain normothermia throughout the procedure. A single dose of intravenous cefazolin (50 mg/kg) was given immediately prior to beginning the procedure, and the scalp was prepared with Betadine solution. A 2 to 2.5 cm incision was made behind the anterior fontanelle with its epicenter over the sagittal suture. An electrocautery unit with a pencil tip set at low wattage (15 W), was used to develop a dissecting plane between the galea and the pericranium in a bloodless fashion. Visualization of this plane was obtained using a 0 4-mm rigid rod lens endoscope and a rhinoplasty lighted retractor. The plane of the dissection was directed posteriorly to the area of the lambda and laterally 3 to 4 cm on either side of the midline. A second midline transverse incision (2 2.5 cm) was made immediately anterior to the lambda. The subgaleal dissection was extended between the anterior and posterior incisions. A 7-mm long cranial perforator was used to create a burrhole on the lateral aspect of each incision. A No. 1 Penfield dissector was used to separate the dura from the bone under the stenosed sagittal suture, and Kerrison rongeurs were used to create an osteotomy across the midline tailored to the width of the proposed strip craniectomy. At the midline, the osteotomy was extended anteriorly to reach the anterior fontanelle, where the closed suture in this area was fully released. In a similar fashion, a transverse midline osteotomy was made posteriorly, in front of the lambda. A 30 angled, 4-mm rigid endoscope was then inserted under the bony edge of the anterior osteotomy and advanced posteriorly. With the aid of a small (No. 7 French) malleable metal suction tip as a dissector, the dura was gently drawn away from the overlying bone; venous oozing obstructing the endoscopic view was removed. Because the normal dural interdigitation fibers that extend into an open suture are absent in cases of craniosynostosis, the dura over the sagittal sinus was easily stripped off the stenosed sagittal suture. Occasionally, when small perforating veins extending into the overlying bone were encountered, they were easily cauterized and sharply incised under direct endoscopic visualization without complication. Dural dissection was continued until the posterior osteotomy was reached. Following complete dissection of the bone from the dura mater and scalp, bone-cutting scissors were used to connect the lateral aspects of anterior and posterior osteotomies. The wide-strip craniectomy was then removed via the anterior incision in either one or two segments. Using an insulated brain retractor or a blunt dissector, the dura was dissected from the bone extending from the lateral edge of the craniectomy toward the squamous suture. Curved scissors were used to create barrel-stave osteotomies laterally and inferiorly toward the temporal and parietal regions. Although overall hemostasis was obtained using thrombin and gelfoam, osseous hemostasis was achieved using a suction coagulator set at 25 W. The wounds were closed with a galeal Vicryl suture and the skin sealed with collodion. Within a week after surgery, the patients were fitted with custom-made surlyn helmets designed to minimize growth in the anteroposterior direction while allowing for expansion of the skull in the lateral dimensions. The helmets were worn until the patients reached 10 to 12 months of age. Sources of Supplies and Equipment We obtained the heating unit (Bair Hugger) from Augustine Medical, Inc., (Eden Prairie, MN). Valley Lab, Inc. (Boulder, CO) manufactured the electrocautery unit (Bovie) used to establish a dissecting plane between the galea and pericranium, as well as the suction coagulator. The Hopkins endoscope (GAAB neuroendoscope) was acquired from Codman and Shurtleff (Rayham, MA), and the lighted retractor was purchased from Techman (Charlton City, MA). The cranial perforator is produced by Acracut (Acton, MA). We obtained the spreading calipers from GPM Instruments (Switzerland). RESULTS In no case was there need for discontinuation or conversion to an open procedure. The mean intraoperative infusion of crystalloids was 243 ml ( ml). The mean estimated blood loss was 31.8 ml (range ml). Only one patient required an intraoperative blood transfusion of 150 ml. Postoperatively nine patients required non-life threatening donor directed blood transfusions (mean transfusion 93 ml; range ml) (Table 1). The estimated percent of blood volume lost was 6.1% (range %). The size of the strip craniectomy varied inversely with the patient s age. The mean width was 4.6 cm (range cm) and the mean length was 9.6 cm (range 7 13 cm). The average length of hospitalization was 1.07 days. Fifty-six patients were discharged on the 1st postoperative day, two patients on the 2nd postoperative day, and one patient on the 3rd postoperative day. Pyrexia was uncommon; the mean maximum body temperature recorded was 37.8 C (range C). Mean hematocrit levels measured in the recovery room were 26.2% (range 17 32%), indicating a 19.4% drop from the preoperative values. On the 1st postoperative day the mean hematocrit 2 Neurosurg. Focus / Volume 9 / September, 2000

3 Sagittal suture craniosynostosis TABLE 1 Characteristics and results in patients with craniosynostosis who underwent craniotomy, osteotomy, and fitting with a custom-molded helmet* Characteristic Mean Range age (mos) follow up (mos) EBL (ml) BVL (%) blood transfusion (ml) preop HCT (%) postop HCT (%) op time (mins) * BVL = blood volume loss; EBL = estimated blood loss; HCT = hematocrit. level was 23.2% (range 17 32%), which represented a 23.2% reduction from baseline preoperative levels. The mean operative time was 50.6 minutes (range minutes). The longer operative times reflected procedures in three patients with multiple suture synostosis. No direct sagittal sinus injuries or tears were sustained. There were no cases of dural tears or intraparenchymal injuries, infections, postoperative hematomas, seizures, or coagulopathies. In five patients small areas of superficial skin irritation that developed along portions of the incision line were thought to be secondary to skin moisture and maceration by the helmet lining; in all cases, the helmet was removed for several days, and the irritation resolved. There were no cases of residual scarring or areas of alopecia. In four patients, the area of the anterior fontanelle reossified abnormally and led to a raised calvaria. The amount of osseous elevation was approximately 5 mm, and this has significantly resolved in the older patients. In all of these cases, the patients had persistently raised and pulsatile anterior fontanelles. The mean preoperative CI was 63.8 with a range of 61 to 73 (mean normal CI is 83 ± 1 [mean ± standard deviation]). At 3.4 months postoperatively, the maximum mean CI of 77.2 (range 68 89) was observed; this was a 22.5% mean increase over preoperatively baseline levels. The mean CI at last follow up was 73.2, which was an overall increase of 16.3% over preoperative baseline values. (All postoperative CI measurements reflected a mean within 2 standard deviations from the normal mean [Figs. 2 6]). DISCUSSION Although Stahl and Hyrtl appear to have first proposed the concept that skull deformities are caused by premature calvarial suture closure, it was Virchow, in 1851, who first presented an organized and cohesive heory regarding the pathophysiology of craniosynostosis (for a translation of the original work, see Persing, et al. 36 ). In 1892, Lane 24 reported the first attempt at treating a 9-month-old patient with craniosynostosis and microcephaly. He first removed a 1-inch strip of bone extending from the anterior to the posterior fontanelle and then created bilateral parietal osteotomies resembling a cross. Prior to Lane's report, Lannelongue 25 described a linear craniectomy in which a strip of bone was removed from the calvaria, parallel to the obliterated sagittal suture. In 1894, however, Jacobi 18 reported significant morbidity and mortality rates in a series of 33 cases, which ultimately led to the discontinuation of craniosynostosis surgery for the next three decades. Faber and Towne 11 reintroduced the concept of surgical intervention in patients with craniosynostosis as a prophylaxis against blindness and other complications. In that and in a later report, 12 they stressed the need for early operative intervention that is, treating patients between the ages of 1 and 3 months of age. Subsequently, neurosurgeons opted to undertake strip craniectomies or other various modifications in the treatment of patients with craniosynostosis. 2,3,8 10,15,23,38,39,41 Inconsistent results obtained using simple strip craniectomies, however, led surgeons to ever more complex and invasive procedures. 6,14,21,29,31,35,43 Large numbers of more extensive and invasive procedures have been reported including midline vertex craniectomy, 4 and reverse procedures, 6,17,21,23 total vertex craniectomy, 10 bilateral parietal flap craniectomies, 37 sagittal strip with circular occipital Fig. 2. Left: Anteroposterior photograph of a 2-week-old infant (adjusted age) born at 26 weeks' gestation with scaphocephaly and a CI of 60. There is significant bitemporal and biparietal narrowing and moderate compensatory oxicephaly. Right: Six-month postoperative AP photograph demonstrating marked increased euryonto-euryon distance and expansion of the skull base. Neurosurg. Focus / Volume 9 / September, 2000 Fig. 3. Left: Preoperative posterior photograph showing restricted lateral calvarial growth associated with severe scaphocephaly and oxicephaly. Right: Six-month postoperative photograph showing lateral calvarial expansion and a well-rounded 3

4 D. F. Jimenez and C. M. Barone Fig. 4. Left: Aerial photograph of the patient in Fig. 1, demonstrating increased glabella-to-opisthocranium length as well as marked bifrontotemporal narrowing. Right: Postoperatively, the patient s CI increased from 60 to 83, indicating adequate normalization of cranial vault shape. Fig. 5. Upper Left: Preoperative aerial photograph of 4-weekold girl (previously reported 21 ) showing a scaphocephalic head with marked frontal and occipital bossing. Upper Right: Postoperative photograph obtained 3.5 years after surgery, showing complete correction scaphocephalic of skull. A CI of 79.2 was obtained. Lower Left: Preoperative lateral photograph showing significant frontal and occipital bossing. Lower Right: Postoperative lateral photograph obtained 3.5 years postsurgery demonstrating normalization of the cranial vault dimensions and proportions. and parietal wedge craniectomies, 1 keyhole craniectomy, 30 and various other types of CVR. 7,26 29,42 Calvarial vault remodeling is currently the technique of choice undertaken at many craniofacial centers. The reported blood loss associated with CVR is significant, ranging from 300 to 1500 mls; 13,17,22,32 operative times range from 4 to 8 hours; 16,33 and lengths of hospitalization range from 4 to 7 days. Blood transfusions are a universal necessity in CVR procedures and range from as little as 25% of the patient blood volume to 500%. 7,14,16,18,22,33 Complications include syndrome of inappropriate antidiuretic hormone secretion, hypotension and cardiovascular collapse secondary to unrecognized hemorrhage, 6 dural tears, 10 embolism, 16 sagittal sinus tears, hypophosphatemia, 18 hyponatremia, and residual calvarial defects. 7 Although previous authors have proposed that cranial base abnormalities are the cause of sagittal craniosynostosis, 42 careful review of modern high-resolution computerized tomography scans failed to demonstrate closure of any of the skull base synchondrosis or sutures. Calvarial deformities appear simply to be due to restrictive calvarial growth and the associated compensatory changes following closure of the sagittal suture. The type of deformity is directly related to which part(s) of the suture is stenosed and how early the closure occurs. We agree with many authors that early release of the stenosed suture will halt the progressive deformity and lead to a certain degree of correction. There is, however, a tendency for the skull to resume a scaphocephalic shape within the 1st year of life. Premature reossification is also a problem that develops after small strip craniectomies and craniosynostectomies have been performed. Controversy remains in the neurosurgical, plastic surgery, and craniofacial surgery literature regarding the best procedure for treating sagittal craniosynostosis. Proponents of both camps will cite the benefits of each procedure. 34,40 Because we have performed a large number of CVR procedures, we have significant experience with these types of interventions. Excellent results can indeed be achieved but often times at significant cost to the patient. Long operative times, increased blood loss, long periods of hospitalization, significant scalp and facial swelling, fever, and pain are commonly associated with these cases. Microtitanium plates and microscrews have been extensively used in craniofacial surgery. However, a number of these plates and screws have been found to migrate through the bone, the dura, and into the brain, necessitating their removal. 5 Other causes necessitating removal of hardware include loosening of the plates and screws as well as cystic formation around them. Inappropriate fusion of the bone graft often leads to uneven ossification, producing many bumps and lumps. The procedure we present was developed with the aim to decrease the problems commonly associated with CVR procedures. There is, however, a learning curve associated with this procedure, particularly with the use of endoscopes. Surgeons not familiar with endoscopic techniques and equipment will find this a demanding procedure. Over time, because we have simplified this operation, we now have operative times of approximately 30 minutes and blood loss ranging from 10 to 30 mls. A key to decreasing blood loss has been the generous use of gelfilm and thrombin spray. Additionally, most bleeding occurs from the diploe following the osteotomies. We have been able 4 Neurosurg. Focus / Volume 9 / September, 2000

5 Sagittal suture craniosynostosis Fig. 6. Left: Preoperative AP photograph of a 9-week-old boy with sagittal suture craniosynostosis, showing frontal bossing and decrease in the bitemporal and biparietal width. Center: Photograph obtained 2.5 years postoperatively, showing the patient with a CI of 75 and lateral expansion of the calvarial vault. Right: Lateral photograph obtained 2.5 years postoperatively, showing complete correction of scaphocephaly and normal calvarial length and height. Neurosurg. Focus / Volume 9 / September, 2000 to achieve a significant decrease in blood loss since the introduction of the suction coagulator which is used to cauterize the bone directly. In our cases the criteria used for blood transfusion included a hematocrit level less than 19%, the presence of tachycardia (> 170 bpm) and/or hypotension, or an oxygen saturation level less than 90%. Perhaps the most challenging cases have been those patients in whom bridging emissary veins extend from the sagittal sinus into overlying osseous channels. However, with the aid of the endoscope and bipolar cautery, we have been able to cauterize and section those veins successfully without causing bleeding or adverse effects. Changes in the shape of the cranium occur immediately and are noted intraoperatively. Bifrontal bossing is commonly seen in sagittal craniosynostosis when the restrictive forces placed on the posterior frontal and parietal lobes by the stenosed sagittal suture cause a compensatory growth response of the frontal lobes. There are no intrinsic pathological or anatomical abnormalities associated with the frontal bones. By restricting frontal growth while allowing bilateral expansion of the brain, the malleable deformed head of an infant can be easily corrected with a properly fitted helmet. We have found no need to address frontal bossing surgically, as this condition has been corrected in all of our patients with the use of the molding helmet therapy. Increases in the euryon-to-euryon distance are evident immediately following removal of the bone and creation of barrel-stave osteotomies. Recession of a prominent forehead is also evident soon after surgery. The molding helmets are used to achieve normal CIs and calvarial proportions. Because significant changes in the shape of the patient's head occur immediately following surgery and because a small amount of subgaleal swelling is demonstrated in the early postoperative period, the patients are not fitted for the helmets until Day 4 or 5 postoperatively; the helmets are then worn until the patient is 11 or 12 months of age. The tendency for the head to resume a scaphocephalic shape, often seen in these patients, can be successfully counteracted with the use of a molding helmet, which is worn during the critical period of rapid brain growth that occurs during the first 12 months of life. Because there is significant deceleration of brain growth after 12 months of age the possibility of relapse is decreased. Close follow-up examination and proper helmet shape and fitting are of utmost importance, because an improperly fitted helmet will certainly yield poor results. In all of our patients who have reached 3 years of age normocephaly has been maintained. It is extremely unlikely that the cranium will revert to preoperative abnormal shape given the fact that most cranial growth (85%) has been achieved by this age. Although we understand that the CI is only a crude measure of overall skull shape, nevertheless it provides the observer with a relative objective anthropometric measurement that can be used to follow trends in head morphology and skull proportionality. CONCLUSIONS Endoscopy-assisted vertex-strip craniectomy followed by the placement of custom-made molding helmets is an excellent alternative in the treatment of sagittal craniosynostosis. This procedure provides superior results, overall decreases in morbidity, blood loss, transfusion rates, and hospital costs, compared with conventional CVR procedures. Acknowledgment The authors thank Mary Bess for her assistance in the preparation of this manuscript. References 1. Albright AL: Operative normalization of skull shape in sagittal synostosis. Neurosurgery 17: , Anderson FM, Geiger L: Craniosynostosis. A survey of 204 cases. J Neurosurg 22: , Anderson FM, Johnson FL: Craniosynostosis: a modification in surgical treatment. Surgery 40:961, Andersson H, Gomes SP: Craniosynostosis. Review of the lit- 5

6 D. F. Jimenez and C. M. Barone erature and indications for surgery. Acta Paediatr Scand 57: 47 54, Barone CM, Jimenez DF: Special considerations in pediatric cranial fixation: a technical overview. J Craniomaxillofac Trauma 2:42 47, Boop FA, Shewmake K, Chadduck WM: Synostectomy versus complex cranioplasty for the treatment of sagittal synostosis. Childs Nerv Syst 12: , Burstein FD, Hudgins RJ, Cohen SR, et al: Surgical correction of severe scaphocephalic deformities. J Craniofac Surg 5: , Davis CH Jr, Alexander E Jr, Kelly DL Jr: Treatment of craniosynostosis. J Neurosurg 30: , Drake DB, Persing JA, Berman DE, et al: Calvarial deformity regeneration following subtotal craniectomy for craniosynostosis: a case report and theoretical implications. J Craniofac Surg 4:85 90, Epstein N, Epstein F, Newman G: Total vertex craniectomy for the treatment of scaphocephaly. Childs Brain 9: , Faber HK, Towne EB: Early craniectomy is a preventive measure in oxycephaly and allied conditions. With special reference to the prevention of blindness. Am J Med Sci 173: , Faber HK, Towne EB: Early operation in premature cranial synostosis for the prevention of blindness and other sequelae. Five case reports with follow up. J Paediatr 22: , Faberowski LW, Black S, Mickle JP: Blood loss and transfusion practice in the perioperative management of craniosynostosis. J Neurosurg Anesthesiol 11: , Greene CS Jr, Winston KR: Treatment of scaphocephaly with sagittal craniectomy and biparietal morcellation. Neurosurgery 23: , Hahn JF, Trusso R, Levy WJ: Craniosynostectomy with reduced blood loss. Neurosurgery 8: , Harris MM, Yemen TA, Davidson A, et al: Venous embolism during craniectomy in supine infants. Anesthesiology 67: , Hudgins RJ: Total calvarial reconstruction for sagittal synostosis in older infants and children. J Neurosurg 78: , Jacobi A: Non nocere. Med Rec 45:609, Jane JA, Edgerton MT, Futrell JW, et al: Immediate correction of sagittal synostosis. J Neurosurg 49: , Jimenez DF, Barone CM: Endoscopic craniectomy for early surgical correction of sagittal craniosynostosis. J Neurosurg 88:77 81, Kanev PM, Lo AKM: Surgical correction of sagittal craniosynostosis: complications of the pi procedure. J Craniofac Surg 6: , Kearney RA, Rosales JK, Howes WJ: Craniosynostosis: an assessment of blood loss and transfusion practices. Can J Anaesth 36: , Klein MF: La craniosténose. Neurochirurgia 4:65 79, Lane LC: Pioneer craniectomy for relief of mental imbecility due to premature sutural closure and microcephalus. JAMA 18:49 50, Lannelongue M: De la craniectomie dans la microcéphalie. Compt Rend Seances Acad Sci 110: , Marchac D, Renier D: Craniofacial Surgery for Craniosynostosis. Boston: Little, Brown, 1982, pp Maugans TA, McComb JG, Levy ML: Surgical management of sagittal synostosis: a comparative analysis of strip craniectomy and calvarial vault remodeling. Pediatr Neurosurg 27: , McCarthy JG: New concepts in the surgical treatment of the craniofacial synostosis syndromes in the infant. Clin Plast Surg 2: , McComb JG: Occipital reduction biparietal widening technique for correction of sagittal synostosis. Pediatr Neurosurg 20:99 106, McDermott MW, Steinbok P, Cochrane DD: Keyhole craniectomy for correction of sagittal synostosis. Childs Nerv Syst 5: 50 51, McLaurin RL, Matson DD: Importance of early surgical treatment of craniosynostosis. Review of 36 cases treated during the first six months of life. Pediatrics 10:637, Meyer P, Renier D, Arnaud E, et al: Blood loss during repair of craniosynostosis. Br J Anaesth 71: , Moylan S, Collee G, Mackensie A, et al: Anaesthetic management in paediatric craniofacial surgery. A review of 126 cases. Paediatr Anesth 3: , Mullan S: Late moulding of the scaphocephalic skull. Am J Dis Child 99:55, Olds MV, Storrs B, Walker ML: Surgical treatment of sagittal synostosis. Neurosurgery 18: , Persing JA, Jane JA, Shaffrey M: Virchow and the pathogenesis of craniosynostosis: a translation of his original work. Plast Reconstr Surg 83: , Samra KA, Sorour O: Bilateral flap operation for craniosynostosis. J Neurosurg 29: , Shillito J Jr: A plea for early operation for craniosynostosis. Surg Neurol 37: , Shillito J Jr, Matson DD: Craniosynostosis: a review of 519 surgical patients. Pediatrics 41: , Sorour O: The four-flap operation. A new operation for treatment of craniosynostosis. J Neurosurg 18:86 90, Teng P: Premature synostosis of the sagittal suture and its treatment. A modification of the linear craniectomy and the use of synthetic fabrics. J Neurosurg 19: , Turvey TA, Gudeman SK: Nonsyndromic craniosynostosis, in Turvey TA, Vig KWL, Fonseca RJ (eds): Facial Clefts and Craniosynostosis. Principles and Management. Philadelphia: WB Saunders, 1996, pp Vollmer DG, Jane JA, Park TS, et al: Variants of sagittal synostosis: strategies for surgical correction. J Neurosurg 61: , 1984 Manuscript received July 24, Accepted in final form August 16, Address reprint requests to: David F. Jimenez, M.D., F.A.C.S., Division of Neurosurgery, One Hospital Drive, Room N521, Columbia, Missouri jimenezd@health.missouri.edu. 6 Neurosurg. Focus / Volume 9 / September, 2000