Variants of sagittal synostosis: strategies for surgical correction

Calvarial bone distraction with a contractile bioresorbable polymer

The aim of the present study was to evaluate the possibility of mobilizing calvarial bone with a fully implantable and bioresorbable device. The animal model used was the New Zealand white rabbit (n = 12). An island bone flap attached to the dura mater was created in the parietal region and amalgam markers were placed in this bone flap and in the ipsilateral frontal bone. In one group of six rabbits (group 1), a specially processed contractile 70L/30D,L polylactic acid plate, 15 x 6 x 0.6 mm, was attached to the island flap by one extremity, and to the fixed ipsilateral frontal bone by the other. In group 2 (control), no plate was added. Bone marker movement was followed with serial radiography. In group 1, there was a progressive reduction in mean marker distance over the first 48 hours, and stability thereafter. In group 2 (control), mean marker distance remained stable until the second postoperative week, after which time there was a slight increase until the end of the experimental period. At 4 weeks, the mean marker separation differed significantly between group 1 (mean, -3.62 mm; SD, 0.79 mm) and group 2 (mean, 0.34 mm; SD, 0.14 mm; p <0.001). In conclusion, a totally implantable and bioresorbable device was successfully used to mobilize calvarial bone. Polymer contractility will likely constitute the basis of a new generation of bioresorbable distractors for use in craniofacial surgery.

Results of cranial vault reshaping

This study was designed to assess the outcome of cranial vault reshaping for correction of deformity of the skull and the upper face. A retrospective review of all children who underwent cranial vault reshaping by a single team of surgeons between 1993 and 1996 was performed. There were 10 children in the series. The age at surgery ranged from 6 to 62 months (mean age, 25 months). Five children in the series had untreated sagittal craniosynostosis with scaphocephaly, two had pansynostosis resulting in cloverleaf skull deformity, and three had turricephaly after shunt treatment of hydrocephalus. There was no operative mortality. Blood loss ranged from 250 to 1,500 ml (mean, 422 ml). All patients needed transfusion. There were two major complications resulting from increased intracranial pressure, but both patients recovered completely with no neurological sequelae. Titanium plates and screws were used in all patients, but were removed in two when they became palpable. The 5 children with sagittal craniosynostosis had a normal head shape. The 2 children with cloverleaf skull have improved head shape with persistent increased bitemporal width and round faces. The 3 children with turricephaly after shunting have marked improvement with mild persistent deformity. This study shows that cranial vault reshaping is safe and can lead to a long-term normal head shape in children with late correction of sagittal craniosynostosis. Children with more severe anomalies, particularly syndromic patients, can be improved but will have persistent mild deformity.

Clinical Outcome of the Modified Pi-Plasty Procedure for Sagittal Synostosis

The aim of the study was to evaluate the modified pi-plasty procedure for the treatment of sagittal synostosis, assessing the issues of safety, complications, morphological outcome, and degree of parental satisfaction. A retrospective evaluation of 110 patients with nonsyndromal single suture sagittal synostosis operated on with the modified pi-plasty procedure was undertaken. Cephalometric radiographs were obtained preoperatively and postoperatively at ages 3 and 5 years in three standardized projections. The Cephalic Index and the Axial Width Ratio were determined and used as objective outcome measures. An evaluation of the radiographic digital markings was carried out using a Beaten Copper Score. A parental questionnaire was used to obtain a subjective esthetical outcome assessment. The patient population consisted of 76% boys and 24% girls with a 20% incidence of a positive familial history of craniosynostosis. The mean age at surgery was 7.73 months. Morbidity from the procedure was minimal and there were no mortalities. The Cephalic Index changed from a mean preoperative value of 65% to a postoperative mean value of 72% (P = 0.00004). The mean Axial Width Ratio changed from a preoperative 80% to 72% at the 3-year evaluation (P = 0.00029). The Beaten Copper score changed from a mean preoperative value of 2.35 to 5.42 postoperatively at 3 years (P = 0.00001). The response rate to the questionnaire was 86%, and there were significant postoperative improvements in all studied aspects of the skull shape. The modified pi-plasty is a safe technique, and it induces significant objective changes in skull morphology toward normality. It also yields a high degree of parental satisfaction with regard to aesthetic outcome, as evaluated by a written questionnaire.

Multiple-revolution spiral osteotomy for cranial reconstruction. Technical note

Various combinations of cranial remodeling techniques are used in an attempt to provide optimal cosmetic results and to reduce possible sequelae associated with craniosynostosis. One element of deformity that is difficult to correct directly is an overly flattened area such as that found in the parietal area in sagittal synostosis, unilaterally in lambdoid synostosis, or even in severe positional molding. The authors present a novel application for recontouring cranial bone, namely the multiple-revolution spiral osteotomy. The advantages of this technique include the avoidance of large areas of craniectomy and immediate correction of the cranial deformity. The surgical procedure, illustrative cases, early results, and apparent benefits of this technique are discussed.

Mental development after modified pi procedure: dynamic cranioplasty for sagittal synostosis

A prospective developmental assessment was performed on 26 patients operated on with dynamic cranioplasty for sagittal synostosis. Because this technique entails the application of compressive force, it was of great concern to assess the effect of surgery on development and mental status. The surgical technique used was a modified pi procedure. Perioperative variables were recorded. Six patients underwent preoperative intracranial pressure (ICP) measurements. To evaluate objectively the developmental outcome, the Griffiths' Mental Development Scales was used for analysis before and after surgery. A parental questionnaire was used for subjective outcome measurement. Preoperative ICP recordings during sleep ranged from 12.8 to 22.8 mmHg (mean, 16.1 mmHg). The mean age at the time for surgery was 6.9 months (range, 4-16 months; standard deviation [SD], 2.32 months). The surgical technique included shortening of the anteroposterior diameter of the skull by a mean of 16.6 mm. The mean global development quotient (GDQ) preoperatively was 104.5 (range, 82-144; SD, 12.4) and the mean GDQ postoperatively was 101.4 (range, 62-129; SD, 13.6). Mean age at follow-up was 16.3 months (range, 9-40 months; SD, 4.04 months). There was no significant correlation between the amount of intraoperative shortening and mental development. In comparison of means, the GDQ preoperatively did not differ significantly from the GDQ postoperatively. The modified pi procedure is safe and efficient. When surgery was performed before 1 year of age, no significant (p = 0.33) effect on mental development-either detrimental or beneficial-was demonstrated.

Surgical correction of scaphocephaly: experiences with a new procedure and follow-up investigations

INTRODUCTION

Simple resection of the sagittal suture and the use of alloplastic material or extensive skull resections have long been proven to be unsatisfactory in the treatment of sagittal synostosis. In contrast to these experiences, the immediate correction of skull shape seems to yield the best results without significant morbidity.

PATIENTS

Thirty-six scaphocephalic infants with an average age of 6.5 (3.5-14) months underwent operation by our craniofacial team since 1994.

METHODS

Wide resection of the sagittal suture was used in combination with a bone-strip resection along the coronal and lambdoid sutures. Occasionally partial resection and reshaping of the frontal or occipital bone was necessary to correct an extremely bulging skull. The cranial growth and shape was monitored by anthropometric skull measurements in the last 20 patients.

RESULTS

Except in two cases, in which the dura mater was minimally injured intraoperatively, no complications occurred in any patient. Craniofacial oedema always occurred but disappeared after 72 h. The immediate correction of the skull shape was successful in all cases and was completed within 6 months postoperatively. There was no iatrogenic bone defect one year after surgery. Postoperative skull shape and growth was normal.

CONCLUSION

These procedures seem to be effective in the treatment of scaphocephalus. Further normalization of skull shape is achieved by unrestricted postoperative brain growth.

Endoscopy-assisted wide-vertex craniectomy, “barrel-stave” osteotomies, and postoperative helmet molding therapy in the early management of sagittal suture craniosynostosis

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 “barrel-stave” 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.

Pediatric neurosurgical disease

The most common, primary referrals to a pediatric neurosurgeon's office are the evaluation and management of the child with a large head (to rule out hydrocephalus and other space occupying lesions) a mishappen head (to rule out various forms of craniosynostosis), or some form of congenital spinal abnormality (spinal dysraphism). The authors discuss the pathogenesis and clinical features of these disorders, provide a framework for diagnostic evaluation and referral, and discuss the various treatment options available for each.

Surgical treatment of premature sagittal synostosis

A series of 50 consecutive children with premature sagittal synostosis is reported. All were treated surgically; 43 were male, 47 were leukodermic and two are siblings. In the pre-operative examination, the head shape, skull measurements and radiologic findings were evaluated; 38 children were operated on before six months of age and 12 of them, between six and 12 months of age. The surgical technique used was a wide biparietal craniectomy. Blood transfusions were occasional, being necessary for only six (12%) children. The children were admitted at the day of surgery and discharged between the second and third post-operative day. No local or general complications were observed and no one died. The aesthetic result was considered good. The altered skull measurements before surgery reached normalization as far as the end of the first year after the treatment. It may be concluded that wide biparietal craniectomy is a procedure of great effectiveness in the treatment of the premature fusions of the sagittal suture.

Surgical treatment of craniosynostosis: outcome analysis of 250 consecutive patients

OBJECTIVE

Surgery for craniosynostosis has evolved rapidly over the past two decades, with increased emphasis on early, extensive operations. Older published series may not accurately reflect more recent experience. Our study was designed to analyze outcome in a large series of consecutive patients treated recently at a single center.

METHODS

We reviewed 250 consecutive patients who underwent surgical treatment of craniosynostosis between January 1, 1987 and December 31, 1992. They were divided into nine groups by suture involvement: sagittal, unilateral coronal, bilateral coronal, unilateral lambdoid, bilateral lambdoid, metopic, multiple suture, the Klee-blattschädel deformity (cloverleaf skull), and acquired craniosynostosis. Outcome was analyzed in terms of residual deformities and irregularities, complications, mortality, as well as the need for additional surgery.

RESULTS

There were 157 males (62. 8%) and 93 females (37.2%), with most of the male preponderance accounted for by the large sagittal synostosis group, which consisted of 82 males and 25 females. Median age at first operation was 147 days. A named syndrome was present in 23 patients (9.2%) and was more common than expected with bilateral and unilateral coronal synostosis, the Kleeblattschädel deformity, and multiple suture synostosis. There were two deaths (0.8%), both with Klee-blattschädel patients, and 17 other complications (6.8%). Morbidity and mortality were significantly associated with secondary vs primary operations and syndromic vs nonsyndromic patients. Outcome analysis revealed the best surgical results with metopic synostosis and significantly less good results with the Kleeblattschädel deformity, multiple suture synostosis, and bilateral coronal synostosis.

CONCLUSIONS

Using modern surgical techniques, craniosynostosis can be corrected with good outcomes and relatively low morbidity and mortality, particularly for otherwise healthy, nonsyndromic infants.

A stable positioning for patients requiring large calvarial exposure for surgical correction of cranial synostosis

We present a simple and elegant method of positioning the child's head for repair of craniosynostosis. The Sugita head holder allows large exposure of the calvarium with little risk of injury, dislocation or extensive blood loss caused by venous compression. We operated upon 37 patients (age range, between 3 and 132 months, median age 7 months) and did not observe any complication or lesion caused by positioning.

Outcome analysis of 85 patients undergoing the pi procedure for correction of sagittal synostosis

The authors present a retrospective review of their experience with 85 cases using the pi procedure to correct sagittal synostosis. A male preponderance of four to one was recognized in this group. Sixty-five infants underwent computerized tomography scanning of the head prior to surgery; these scans revealed unexpected intracranial pathology in 5% of cases. Surgical complications included three intraoperative dural lacerations. All children received blood transfusions with no complications. Cosmetic outcomes were excellent in 53%, good in 43%, and poor in 4% of cases. One patient required reoperation. All poor outcomes were in infants who were younger than 8 weeks of age at the time of surgery and who underwent a "reverse pi" procedure. Most of the excellent outcomes occurred in infants who were between 3 and 6 months of age at the time of surgery. Although more extensive than strip craniectomy, the pi procedure can be accomplished with minimal morbidity. In the authors' opinion, the pi procedure provides better immediate and long-term cosmetic results than synostectomy alone.

Synostectomy versus complex cranioplasty for the treatment of sagittal synostosis

Although pediatric neurosurgeons traditionally have been trained to perform a sagittal synostectomy for the treatment of sagittal synostosis, numerous articles advocating modifications of this procedure or more complex cranial vault reconstructions point our the inadequacies of strip craniectomy in providing optimal short- and long-term cosmesis. This review addresses the major arguments for and against performing complex cranioplasties for sagittal synostosis, as well as issues regarding timing of surgery, mortality and morbidity, increased need for blood transfusion, and increased expense. The authors support the contention that for the majority of infants with sagittal synostosis, complex calvarial vault reconstruction provides a better outcome with little increase in operative risk.

Late correction of sagittal synostosis in children

Twelve patients with sagittal synostosis underwent correction between 8 months and 8 years of age. The patients underwent expansion in the parietal region of 4 cm and had a reduction in length of 3 cm following dural plication. Average follow-up was 2.2 +/- 0.8 years (mean +/- SD). While optimal treatment for sagittal synostosis may be obtained in the first few months of life, late correction of sagittal synostosis may be obtained in a safe and effective manner.

Total calvarial reconstruction for sagittal synostosis in older infants and children

Premature closure of the sagittal suture is the most common form of craniosynostosis, but this condition occasionally goes unrecognized until the child is too old to undergo procedures that depend upon continued calvarial growth for success. As the entire calvaria is affected and thus misshapen by sagittal synostosis, late correction involves total calvarial reconstruction. The extensive nature of this undertaking has precluded its utilization despite the presence of significant deformities. Adapting the techniques and experience gained from craniofacial surgery, the authors performed total calvarial reconstruction on nine children with sagittal synostosis and subsequent scaphocephaly diagnosed after the age of 1 year. In each case the goals of shortening the anteroposterior length, widening the biparietal diameter, and reducing frontal and occipital deformities were met. Morbidity consisted of acute blood loss, postoperative hyponatremia, and in one case a residual skull defect. The rationale for this procedure and the techniques utilized are discussed.

Expanding cranioplasty for craniosynostosis and allied disorders

For early correction of craniosynostosis in the newborn or in early infancy, strip craniectomy may produce satisfactory results. For late correction, however, more radical cranial reconstruction procedures are essential in order to achieve adequate remodeling of cranial deformities and normalization of intracranial pressure. Craniosynostosis presents various types of cranial deformity, and different procedures for its correction have been reported. Expanding cranioplasty is presented for the increase of cranial volume and immediate correction of the cranial deformity. This cranioplasty can be applied not only for late correction of various types of craniosynostosis but also for other cranial deformities.

The subarachnoid spaces in craniosynostosis

A review of 85 patients with various forms of craniosynostosis showed predictable patterns of dilatation of the subarachnoid spaces in regions of compensatory skull growth. The characteristic pattern in sagittal synostosis (43 patients) included dilatation of the frontal and occipital subarachnoid spaces associated with the elongation of the anteroposterior dimension of the skull and widening of the interhemispheric fissure. In 11 patients with unilateral coronal synostosis, dilatations of the subarachnoid spaces over the contralateral frontal lobe, the sylvian regions, and the ipsilateral temporal lobe tip were consistent with the skull changes of contralateral frontal bossing, increased bitemporal dimension, and elevation of the sphenoid wing, respectively. Four patients with bilateral coronal synostosis also had enlarged subarachnoid spaces high over the convexities of the brain consistent with the towering configuration of the skull. Four patients with true lambdoid synostosis had dilatation of the subarachnoid space only over the ipsilateral frontal lobe associated with compensatory bossing of the frontal bone. Ten of 14 patients with lambdoid deformities had bilateral enlargement of the subarachnoid spaces suggesting brain atrophy and an underlying motor delay accounting for the position-induced skull changes. The findings suggest that focal hydrodynamic mechanisms are involved in the compensatory skull changes seen in craniosynostosis.

Cranioectodermal dysplasia with sagittal craniosynostosis (Sensenbrenner's syndrome): case report and review of the literature

We report the clinical features and neurosurgical management of a 9-month-old girl with cranioectodermal dysplasia and scaphocephaly. The technique of surgical correction is discussed together with details of the pre-operative investigations. The importance of early referral to an experienced geneticist is emphasized.

Midline craniectomy for sagittal suture synostosis: comparative efficacy of two barriers to calvarial reclosure

This report quantitatively compares long-term head remolding achieved by two methods for retarding bone reunion after midline craniectomy for sagittal suture synostosis. In one group of six children the adjacent bone edges were overlayed with 1.0-cm-wide U-channel silicone strips, and in the other group, composed of seven patients, a considerably larger extent of the adjacent cranium was covered with silicone sheets. Mean percent change in the cephalic indices of the former group 18 months postoperatively was 9.1% +/- S.D. = 6.7, and of the latter group 23.7% +/- S.D. = 6.0 (p congruent to 0.01). These results indicate that the use of large silicone sheets lead to a significantly greater normalization of cranial proportions.

Autologous hemodonation in the corrective surgery of craniostenosis

Homologous transfusions are mandatory in most surgical procedures for correcting craniofacial malformations in infancy. A program of preoperative and intraoperative auto-hemodonation was developed and carried out in eleven infants. Although homologous transfusion could have been avoided in only 7 patients, we think that further experiences and minor corrections of our program may improve these results.

Keyhole craniectomy for correction of sagittal synostosis

A modification of the technique combining sagittal strip, circular occipital and biparietal wedge craniectomies (Albright's procedure) for the treatment of sagittal synostosis, with prominent occipital bossing, is described. "Keyhole," as opposed to wedge, parietal craniectomies allow improvement in the shape of the skull, beginning intraoperatively, while eliminating the outbending of the parietal bone that occurs at the apex of a wedge craniectomy.

Craniosynostosis update 1987

Information on craniosynostosis in this paper updates "Craniosynostosis: Diagnosis, Evaluation, and Management" (Cohen MM Jr: New York: Raven Press, 1986). It also discusses recent developments that were included in the book but need further explanation or emphasis. Subjects discussed are: epidemiology, etiology, sutural biology, growth and development, neurological and psychosocial aspects, surgery, cloverleaf skulls, craniosynostosis syndromes, and prenatal diagnosis. Under the subject of etiology, fetal head constraint, maternal thyroid disease, calcified cephalohematoma, teratogens, and delayed suture closure and Wormian bones are considered. An updating of 15 cloverleaf skull conditions includes four monogenic disorders, two chromosomal disorders, one disruption, one iatrogenic condition, and seven syndromes of unknown cause. Newly recognized disorders with cloverleaf skull include Beare-Stevenson cutis gyratum syndrome and Say-Poznanski syndrome. Craniosynostosis syndromes and associations discussed include acrocraniofacial dysostosis, Apert syndrome, Beare-Stevenson cutis gyratum syndrome, Calabro syndrome, calvarial hyperostosis, chromosomal craniostenosis, Cole-Carpenter type osteogenesis imperfecta, Crouzon syndrome, Curry-Jones syndrome, Curry variant of Carpenter syndrome, cutis aplasia and cranial stenosis, Fontaine-Farriaux syndrome, Gomex-López-Hernández syndrome, Hersh syndrome, hyper-IgE syndrome and craniostenosis, hypomandibular faciocranial dysostosis, Marfanoid features and craniostenosis, Pfeiffer-type cardiocranial syndrome, Pfeiffer-type dolichocephalosyndactyly, and Say-Barber syndrome.

Calvarial growth after linear craniectomy in scaphocephaly as evaluated by X-ray stereophotogrammetry

An roentgen stereophotogrammetric system for the evaluation of skeletal adjustments following corrective surgery in craniosynostosis is described. Four illustrative cases of scaphocephaly, all treated with midline linear craniectomy, with uneventful postoperative follow-up periods of more than 4 years, are reported. The postoperative development, as evaluated by volumetric and kinematic analyses, was uniform but still rich in individual and local growth variations. This study confirms that roentgen stereometry ( = exact measurements from stereoradiographs), being an accurate and objective method, adds greatly to previous methods of postoperative assessment in craniofacial skeletal disorders.

The use of Zenker's solution in linear craniectomy for craniosynostosis: technical modification and reappraisal

Regrowth of bone after craniectomy for craniosynostosis is still a problem, despite the advent of newer and extensive surgical techniques. A clinical study on 25 consecutive patients was undertaken to determine whether a modification of previous routines could retain the advantages of a tissue fixative, Zenker's solution, while eliminating the drawback of convulsive activity. After brief coagulation, Zenker's solution was sparingly applied to the dural surface for maximally one minute followed by copious irrigation of the surgical field. The results were satisfactory and postoperative complications unrelated to the fixative. The present procedure seems safe, effective, and easy to use.