- Email: [email protected]
Endoscopic treatment of craniosynostosis
Atlas Oral Maxillofacial Surg Clin N Am 10 (2002) 57–72
Endoscopic treatment of craniosynostosis Eric J. Stelnicki, MD* Cleft Craniofacial Surgery Center, Joe DiMaggio Children’s Hospital, 3435 Hayes Street, Hollywood, FL 33021, USA
In the past decade, many new frontiers in the treatment of craniosynostosis have been reached. The advent of resorbable plating systems and distraction osteogenesis techniques to reshape the abnormal skulls of children with premature suture fusions has forced surgeons to reanalyze their approach to the treatment of these deformities. Most recently, there has been a push toward minimally invasive surgery. The technology that supports the development of endoscopic surgery has advanced markedly in recent years. New fiber optic endoscopes and multipurpose instruments allow surgeons to perform extensive surgical procedures through small incisions with minimal blood loss and decreased postoperative morbidity while still providing the same or better surgical outcomes. As a result, many surgeries that were once performed through an open technique, such as gallbladder resection or colectomy, are currently performed almost exclusively with an endoscope. The same trend is beginning to develop for the treatment of craniosynostosis. Endoscopic advances have led to significant improvements in surgeons’ ability to correct this disorder surgically. The initial reports of endoscopic treatments appeared in 1998 [1]. The authors demonstrated the efficacy of the procedure on four patients with sagittal craniosynostosis. Although met with initial skepticism, they subsequently have reported long lasting, good results in a larger set of patients and have expanded the indications for endoscopic cranial vault remodeling to include a multitude of other cranial sutures [2]. Similar successes also have been reported at other craniofacial centers. The concept of using minimally invasive surgery to remold the skull is not new. It dates back to the early part of the century, when neurosurgeons performed strip craniectomies to remove the abnormal, premature suture fusions. This process is still performed in some centers through large coronal or sagittal scalp incisions. The unpredictability of the long-term result and a high recurrence rate of the skull deformity, however, have led most institutions to abandon the technique in lieu of formal cranial vault remodeling using plates and screws [3,4]. The endoscopic cranial vault remodeling technique is more than a simple strip craniectomy through a small endoscopic port. It is a wide sutural excision combined with lateral osteotomies and osteoectomies that allow for normalization of the cranial skeleton. Postoperatively, the procedure relies heavily on the use of an external molding band to normalize calvarial form completely. This external band takes the place of internal plates and screws. It typically is in the form of a passive, directional, orthotic device, which is custom made for each child (Fig. 1). The external band provides growth-restraining pressures in areas of protuberance while giving room for growth and expansion in areas that must be widened laterally, posteriorly, or anteriorly [5]. The combination of the endoscopic surgery and the band is essential for achieving a good, long-lasting result. Without both modalities working hand-in-hand, the risk of recurrent suture fusion and abnormal head-shaped postcranial remodeling would increase. The use of molding helmets to change cranial form is currently widespread. This treatment modality dates back to ancient Indians in South America who used various external forces to mold and distort the cranial vaults of their royal families. Currently, the most common
* E-mail address: [email protected] (E.J. Stelnicki) 1061-3315/02/$ - see front matter Ó 2002, Elsevier Science (USA). All rights reserved. PII: S 1 0 6 1 - 3 3 1 5 ( 0 1 ) 0 0 0 0 7 - 5
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Fig. 1. Typical endoscopic postoperative molding bands. On the left is passive band, which directs growth through passive relief of pressure points. The band on the right is a more active device. It has rubber band, which compress the skull in an anteroposterior direction to decrease the anteroposterior length of the skull.
application of a molding helmet or band is in the treatment of deformational plagiocephaly [6]. Seen commonly in every craniofacial practice, bands are being applied to normalize the head shape of thousands of children each year. The use of a helmet or band in the postoperative recontouring of the calvarium is a natural evolution of this current application. The trend toward endoscopic cranial vault remodeling over conventional reconstruction is caused by several distinct advantages. First is the use of small, minimally invasive skin ports that allow entry of the endoscopic equipment and resection of the bone without the need for a full, open scalp incision. In the past, a bicoronal incision or a midline sagittal excision that extended either from ear-to-ear or front-to-back was required to gain adequate exposure for the suture removal. The endoscopic technique relies only on the creation of two 1.5-cm excisions, which are placed at opposite ends of the restricted suture to provide adequate placement of the endoscopic equipment and removal of the bone. This approach significantly decreases scarring and the risk of alopecia, both of which are long-lasting stigmata of an intracranial surgery. The second benefit is in terms of operative time. A typical cranial vault remodeling requires approximately 3 hours to perform the craniectomy, remodel the cranial vault, and return it to a more normalized position using plates and screws. Using the endoscopic approach, the reconstruction can be performed in less than 1.5 hours [2]. This decrease in operative time is caused by omission of the plating step, which is required for a successful conventional cranial vault repair. The third benefit is hospital stay. Instead of the typical 5-day postoperative care that is required after the open procedure, after endoscopic cranial vault remodeling, patients are leaving the hospital in 2 to 3 days [2]. This change decreases the overall cost of the operation. It also implies that patients have decreased postoperative morbidity and pain compared to standard reconstructions. Another advantage is that this procedure can be performed at a young age. Most parents who have a child with a deformed head want the abnormality to be corrected as soon as possible. Before the use of the endoscopic technique, it was the author’s policy to delay treatment as much as possible to maximize calvarial growth before the reconstruction. It was believed that this approach decreased the recurrence risk of the deformity, especially if the repair was carried out at approximately 1 year of age. The postoperative use of a molding band after endoscopic repair has eliminated the need for this latency period. The next benefit is a decrease in overall cost. The three cost-saving measures are (1) decreased operative time, (2) decreased hospital and intensive care unit stay, and (3) no need for expensive internal plating systems for holding the newly placed cranial bone in proper
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position. The plating systems for extensive remodelings can cost in excess of $3000 to $4000 to properly plate and position the calvarial bone segments. This cost is absent in patients who undergo the endoscopic procedure. It is also known that plates can migrate intracranially when used in young patients, which raises the theoretical concern of a dural injury [7]. The lack of a plating system removes this risk. Retained hardware (titanium or resorbable) is also a foreign body that has the potential to become infected. There is virtually no risk of this complication after an endoscopic repair. The disadvantages of the procedure center around the need for the external cranial molding band. The band is an extra expense and costs roughly $2000 per patient. The author uses the DOC band, but many other alternatives exist. If the patient is going to have an endoscopic repair and uses the band, he or she must be willing to be seen weekly for the first 4 months postoperatively to ensure that the cranial form is normalizing. If the family is not dedicated to the banding procedure, an endoscopic cranial vault remodeling should not be performed. There have been cases of patients who have undergone cranial vault remodeling without the use of a postoperative band, the risk of recurrent deformity in these patients is believed to be significantly greater, however. If the surgeon or craniofacial team does not have the ability to create an external band, this procedure should not be offered to the patient. The ability to use the endoscopic technique is based on age and the type of craniosynostosis. The endoscopic repair requires that the surgeon perform the operation before 4 months of age. The reason for this is as follows: First, the endoscopic procedure demands that the bone be thin enough to allow an osteotomy to be made with endoscopic shears or bone cutters. In an older child who has increased calcification throughout the calvarium, modern endoscopic instruments cannot cut through the bone. Perhaps as endoscopic laser bone-cutting techniques are developed, this will be less of a problem, but currently, in patients past 4 months of age, most endoscopic shears and bone cutters physically cannot make the osteotomy. The second factor in terms of age is the bleeding potential of the child. Children under 4 months of age have not developed a significant amount of cancellous space between the two cortices of the inner and outer tables of the skull. As a result, bleeding that is produced from cutting the bone is significantly less in this younger age group [8]. When timing surgery, one should attempt to be past the physiologic nadir of a hematocrit, which normally occurs in the neonatal period. The author also routinely gives recombinant erythropoietin at a dose of 600 IU/kg/wk for the 3 weeks before surgery. This practice builds up the preoperative hematocrit and further decreases the risk of needing an intraoperative blood transfusion. The last age-related component is that the skull must be malleable and in a rapid-growth phase at the time of surgery because of the dependence of the surgery on an external molding band for success. These bands are mostly passive devices that work best on an actively growing skull. Although band therapy for deformational plagiocephaly is effective up to 18 months of age, greater effects are seen when the helmet is used earlier. This is particularly important in the treatment of coronal or lambdoid craniosynostosis, because a normalization of the cranial base by the helmet is also required if the surgery is to be considered a success. In the author’s opinion, cranial base remolding is most effective when generated at a young age. The author initially limited endoscopic cranial vault remodeling to sagittal synostosis because the patients typically have minimal ocular involvement in the deformity (Fig. 2A–F). This technique has been used on various suture fusions with equal success. Corrective changes in the orbital position and cranial base shape are seen after the reconstruction because of the continued use of the band. The author uses the technique as a first part of a two-staged repair on multisutural fusions (Fig. 3A–L). The endoscopic approach and band are used for the initial release, and then a standard cranial vault is performed at 1 year of age to complete the reconstruction when necessary. In some cases, the planned secondary operation is not required.
Surgical method The surgical technique described herein is for the treatment of sagittal craniosynostosis; however, the basic principles are the same, regardless of the location of the suture fusion (Fig. 4A and B).
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Fig. 2. Patient with sagittal suture craniosynostosis treated with an endoscopic repair. (A–C) Preoperative anteroposterior, lateral, and vertex views of patient showing the scaphocephalic appearance of the skull. (D–F), Postoperative anteroposterior, lateral, and vertex views of the same patient showing improved skull shape status after endoscopic repair. (G) Lateral view taken 2 weeks after endoscopic surgery, before the placement of a molding helmet. Note that even without the helmet there was a significant improvement in cranial bone contour. The scaphocephaly is decreased and the occipital bullet has been relieved. Without the molding band, however, the deformity is likely to recur.
Surgical technique for treatment of sagittal craniosynostosis is as follows: The patient is placed in the prone position, with the skull in a U-shaped headrest (Fig. 4C). The neurosurgeon and plastic surgeon then work together on the patient. Incisions of 2 cm are made just anterior to the anterior fontanel and just posterior to the occipital bullet (Fig. 4D). Dissection is performed first in a subgaleal plane to connect the two incisions. This is done with a Freer elevator and a specially designed curved dissector (KLS Martin, Jacksonville, FL, USA). Once the incisions are connected and the overlying scalp is freed, the endoscope is passed into the tunnel. The endocautery is used to coagulate any bleeding vessels. A Codman bur is used to create two holes in the skull on each side of the sagittal suture lateral to the sagittal sinus and
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Fig. 2 (continued )
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Fig. 2 (continued )
anterior to the union of the two lambdoid sutures. Anteriorly, no bur holes are required if the anterior fontanelle is opened. If the anterior fontanelle, however, is fused, then additional bur holes are required in this area. The Kerrison bone rongeur connects the two burr holes taking extreme care not to disturb the underlying sagittal sinus (Fig. 4E). A #3 Penfield and Freer elevator is used to separate the dura in the midline and dissect down to the sagittal sinus. A small rongeur removes as much bone as possible under direct vision. This is performed for an area of
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Fig. 3. Complex, multisuture craniosynostosis patient treated with the endoscopic approach. (A–C) Three-dimensional CT scans demonstrate complete fusion of both coronal sutures and an anterior fusion of the sagittal suture. It should be noted that this scan was performed at birth, although the surgery was delayed until 2 months of age. By 2 months of age, the sagittal suture had fused completely. (D–F) Preoperative view of patient as the patient is being prepared for endoscopic surgery. Note the severe frontal bossing, the bitemporal narrowing, turricephaly, and scaphocephaly. (G–I) Postoperative CT scans taken immediately after surgery demonstrate the extent of the osteotomies used in the endoscopic repair. Even without the helmet there is an immediate improvement in shape. All the bone osteotomies were made through 1.5-cm ports. Only two ports were required. (J–L) Postoperative view of the same patient before Doc Band therapy. Note the small incisions and the immediate improvement in head shape.
up to 2 cm away from the incision with excellent visualization. This approach allows the creation of a large opening for the placement of the endoscopic camera and dissectors (Fig. 4F). After this procedure, the endocamera with a specialized retraction sheath (KLS Martin, Jacksonville, FL) is placed below the endocranial surface of the bone to help reflect down the dura. A specialized periosteal elevator with a curved tip (KLS Martin) dissects the dura away from the overlying fused sagittal suture until the anterior and the posterior portals are connected. Should the sagittal sinus be injured, the two incisions are immediately connected and the bone is removed with a Midas Rex craniotome, which is left on standby in the room for emergencies. The author has never used this Midas Rex but feels better taking the extra safety precautions.
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Fig. 3 (continued )
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Fig. 3 (continued )
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Fig. 3 (continued )
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Fig. 3 (continued )
Once the dura over the sagittal sinus is dissected down off the fused sagittal suture, a 2.5-cm strip of bone is removed, including the entire fused sagittal suture. This is similar to the classic strip craniectomy procedure. The bone is physically removed through the incisions and is not replaced. If the strip of bone that is removed is larger than the skin opening, then the bone is cut down its middle to decrease its width. Once the sagittal segment of bone is removed, attention is directed toward creating barrel stave osteotomies laterally and freeing the occipital and frontal areas (Fig. 4G). A 5-mm strip of bone is removed anterior to each of the lambdoid sutures. Another 5-mm strip of bone is removed anterior to each of the coronal sutures. The endoscope dissects the dura laterally in the temporal and parietal regions. A curved Mayo scissor and a curved bone cutter (KLS Martin) are used to create complete, barrel stave osteotomies from the area of the strip craniectomy down into the mid-temple region. A blunt dissector is used to outfracture each of these barrel stave osteotomies in a Greenstick manner to widen the cranium and increase the cranial index. If there is a large occipital bullet, then the endoscope is used to dissect posteriorly and completely osteotomize the occipital bullet from the surrounding bone. Once the occipital bullet is free floating, anteroposterior compression of the skull is permitted.
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Fig. 4. Endoscopic surgical repair technique for sagittal craniosynostosis. (A) Vertex view showing the locations of the osteotomies used in the endoscopic bone resection. (B) Lateral skull drawing demonstrates the lateral extent of the bone remodeling. Note that the barrel stave osteotomies extend all the way down to the cranial base. (C) Preoperative view of skull with biodrape wrapping in place, which decreases the need to remove all the hair from the patient. (D) Anterior scalp incision and port. The port size is only 1.5 cm in length. The incision is made in the anteroposterior direction. The periosteal elevator is used to dissect the scalp away from the bone in the subgaleal plane. (E) A Kerrison rongeur is used to connect the two bur holes made on each side of the fused sagittal suture to avoid damage to the sagittal sinus. (F) A rongeur is used to remove a 2-cm circle of bone before using the endoscopic equipment. (G) Endoshears and endobone cutters are used to make the lateral, anterior, and posterior osteotomies. (H) Drawing of dura being dissected off the endo-cranial skull surface with the endoscopic technique. (I) Drawing of the lateral barrel stave osteotomies being performed using the endo-bone cutters. The endoscope ensures that only the bone is being cut, and that the underlying dura is protected.
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Fig. 4 (continued )
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Fig. 4 (continued )
If there is a significant amount of narrowing in the temple region, an additional barrel stave osteotomy is performed in the frontotemporal bone to widen this area, which may necessitate the endoscopic elevation of the temporalis muscle in the subperiosteal plane to completely free up the bone. No bone is removed in this area, and osteotomies are created using the bonecutting endoscopic shears (KLS Martin). All other areas of the bone are outfractured laterally to widen the cranial vault and normalize cranial index. A flat Penrose drain is placed through a separate stab incision posteriorly. If any bone bleeding is present, bone wax is placed under direct visualization or through the use of a blunt endoscopic
Fig. 5. Type of Doc Band used in postoperative molding. Lateral view of the active molding band used to correct scaphocephaly. This band has elastics attached to the side to compress the skull in the anteroposterior direction. The band is relieved weekly in the temporal region to allow widening in this area, which normalizes cranial index.
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dissector. Incisions are closed with resorbable sutures and the patient is extubated at the end of the case. After a 2-day stay in the intensive care unit, patients are discharged home wearing a 4-inch bandage wrap. This wrap decreases the postoperative swelling and begins the external remodeling process. At the end of the second postoperative week, the patient is casted for the external molding helmet. He or she returns 1 week later for the first fitting. The helmet is adjusted weekly for the next 4 months to optimize cranial shape. An active anteroposterior compression helmet with two rubber bands on each side of the band is used when treating patients with sagittal craniosynostosis (Fig. 5). This active pressure significantly decreases anteroposterior length and rapidly normalizes the cranial index. At the end of 4 months, a second passive helmet can be applied on selected patients. When treating nonscaphocephalic forms of craniosynostosis, only this passive device is used.
Summary We are entering a new era of craniosynostosis repair. When detected early, endoscopic skull remodeling, combined with a postoperative external skull-molding device, gives an excellent long-standing reconstruction of the cranial skeleton. This technique diminishes the morbidity of the operation and decreases the overall cost. It does not replace classic plate and screw cranial vault reconstruction in the older patient but is a useful weapon in the armamentarium of the craniofacial surgeon for the treatment of craniosynostosis in the neonatal period.
References [1] Jimenez DF, Barone CM. Endoscopic craniectomy for early surgical correction of sagittal craniosynostosis. J Neurosurg 1998;88:77–81. [2] Barone CM, Jimenez DF. Endoscopic craniectomy for early correction of craniosynostosis. Plast Reconstr Surg 1999;104:1965–73. [3] Olds MV, Storrs B, Walker ML. Surgical treatment of sagittal synostosis. Neurosurgery 1986;18:345–7. [4] Panchal J, Marsh JL, Park TS, et al. Sagittal craniosynostosis outcome assessment for two methods and timings of intervention. Plast Reconstr Surg 1999;103:1574–84. [5] Littlefield TR, Beals SP, Manwaring KH, et al. Treatment of craniofacial asymmetry with dynamic orthotic cranioplasty. J Craniofac Surg 1998;9:11–7. [6] Kelly KM, Littlefield TR, Pamatto JK, et al. Cranial growth unrestricted during treatment of deformational plagiocephaly. Pediatr Neurosurg 1999;30:193–9. [7] Stelnicki EJ, Hoffman W. Intracranial migration of microplates versus wires in neonatal pigs after frontal advancement. J Craniofac Surg 1998;9:60–4. [8] Johnson JO, Jimenez DF, Barone CM. Blood loss after endoscopic strip craniectomy for craniosynostosis. J Neurosurg Anesthesiol 2000;12:60.
Endoscopic treatment of craniosynostosis Eric J. Stelnicki, MD* Cleft Craniofacial Surgery Center, Joe DiMaggio Children’s Hospital, 3435 Hayes Street, Hollywood, FL 33021, USA
In the past decade, many new frontiers in the treatment of craniosynostosis have been reached. The advent of resorbable plating systems and distraction osteogenesis techniques to reshape the abnormal skulls of children with premature suture fusions has forced surgeons to reanalyze their approach to the treatment of these deformities. Most recently, there has been a push toward minimally invasive surgery. The technology that supports the development of endoscopic surgery has advanced markedly in recent years. New fiber optic endoscopes and multipurpose instruments allow surgeons to perform extensive surgical procedures through small incisions with minimal blood loss and decreased postoperative morbidity while still providing the same or better surgical outcomes. As a result, many surgeries that were once performed through an open technique, such as gallbladder resection or colectomy, are currently performed almost exclusively with an endoscope. The same trend is beginning to develop for the treatment of craniosynostosis. Endoscopic advances have led to significant improvements in surgeons’ ability to correct this disorder surgically. The initial reports of endoscopic treatments appeared in 1998 [1]. The authors demonstrated the efficacy of the procedure on four patients with sagittal craniosynostosis. Although met with initial skepticism, they subsequently have reported long lasting, good results in a larger set of patients and have expanded the indications for endoscopic cranial vault remodeling to include a multitude of other cranial sutures [2]. Similar successes also have been reported at other craniofacial centers. The concept of using minimally invasive surgery to remold the skull is not new. It dates back to the early part of the century, when neurosurgeons performed strip craniectomies to remove the abnormal, premature suture fusions. This process is still performed in some centers through large coronal or sagittal scalp incisions. The unpredictability of the long-term result and a high recurrence rate of the skull deformity, however, have led most institutions to abandon the technique in lieu of formal cranial vault remodeling using plates and screws [3,4]. The endoscopic cranial vault remodeling technique is more than a simple strip craniectomy through a small endoscopic port. It is a wide sutural excision combined with lateral osteotomies and osteoectomies that allow for normalization of the cranial skeleton. Postoperatively, the procedure relies heavily on the use of an external molding band to normalize calvarial form completely. This external band takes the place of internal plates and screws. It typically is in the form of a passive, directional, orthotic device, which is custom made for each child (Fig. 1). The external band provides growth-restraining pressures in areas of protuberance while giving room for growth and expansion in areas that must be widened laterally, posteriorly, or anteriorly [5]. The combination of the endoscopic surgery and the band is essential for achieving a good, long-lasting result. Without both modalities working hand-in-hand, the risk of recurrent suture fusion and abnormal head-shaped postcranial remodeling would increase. The use of molding helmets to change cranial form is currently widespread. This treatment modality dates back to ancient Indians in South America who used various external forces to mold and distort the cranial vaults of their royal families. Currently, the most common
* E-mail address: [email protected] (E.J. Stelnicki) 1061-3315/02/$ - see front matter Ó 2002, Elsevier Science (USA). All rights reserved. PII: S 1 0 6 1 - 3 3 1 5 ( 0 1 ) 0 0 0 0 7 - 5
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E.J. Stelnicki / Atlas Oral Maxillofacial Surg Clin N Am 10 (2002) 57–72
Fig. 1. Typical endoscopic postoperative molding bands. On the left is passive band, which directs growth through passive relief of pressure points. The band on the right is a more active device. It has rubber band, which compress the skull in an anteroposterior direction to decrease the anteroposterior length of the skull.
application of a molding helmet or band is in the treatment of deformational plagiocephaly [6]. Seen commonly in every craniofacial practice, bands are being applied to normalize the head shape of thousands of children each year. The use of a helmet or band in the postoperative recontouring of the calvarium is a natural evolution of this current application. The trend toward endoscopic cranial vault remodeling over conventional reconstruction is caused by several distinct advantages. First is the use of small, minimally invasive skin ports that allow entry of the endoscopic equipment and resection of the bone without the need for a full, open scalp incision. In the past, a bicoronal incision or a midline sagittal excision that extended either from ear-to-ear or front-to-back was required to gain adequate exposure for the suture removal. The endoscopic technique relies only on the creation of two 1.5-cm excisions, which are placed at opposite ends of the restricted suture to provide adequate placement of the endoscopic equipment and removal of the bone. This approach significantly decreases scarring and the risk of alopecia, both of which are long-lasting stigmata of an intracranial surgery. The second benefit is in terms of operative time. A typical cranial vault remodeling requires approximately 3 hours to perform the craniectomy, remodel the cranial vault, and return it to a more normalized position using plates and screws. Using the endoscopic approach, the reconstruction can be performed in less than 1.5 hours [2]. This decrease in operative time is caused by omission of the plating step, which is required for a successful conventional cranial vault repair. The third benefit is hospital stay. Instead of the typical 5-day postoperative care that is required after the open procedure, after endoscopic cranial vault remodeling, patients are leaving the hospital in 2 to 3 days [2]. This change decreases the overall cost of the operation. It also implies that patients have decreased postoperative morbidity and pain compared to standard reconstructions. Another advantage is that this procedure can be performed at a young age. Most parents who have a child with a deformed head want the abnormality to be corrected as soon as possible. Before the use of the endoscopic technique, it was the author’s policy to delay treatment as much as possible to maximize calvarial growth before the reconstruction. It was believed that this approach decreased the recurrence risk of the deformity, especially if the repair was carried out at approximately 1 year of age. The postoperative use of a molding band after endoscopic repair has eliminated the need for this latency period. The next benefit is a decrease in overall cost. The three cost-saving measures are (1) decreased operative time, (2) decreased hospital and intensive care unit stay, and (3) no need for expensive internal plating systems for holding the newly placed cranial bone in proper
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position. The plating systems for extensive remodelings can cost in excess of $3000 to $4000 to properly plate and position the calvarial bone segments. This cost is absent in patients who undergo the endoscopic procedure. It is also known that plates can migrate intracranially when used in young patients, which raises the theoretical concern of a dural injury [7]. The lack of a plating system removes this risk. Retained hardware (titanium or resorbable) is also a foreign body that has the potential to become infected. There is virtually no risk of this complication after an endoscopic repair. The disadvantages of the procedure center around the need for the external cranial molding band. The band is an extra expense and costs roughly $2000 per patient. The author uses the DOC band, but many other alternatives exist. If the patient is going to have an endoscopic repair and uses the band, he or she must be willing to be seen weekly for the first 4 months postoperatively to ensure that the cranial form is normalizing. If the family is not dedicated to the banding procedure, an endoscopic cranial vault remodeling should not be performed. There have been cases of patients who have undergone cranial vault remodeling without the use of a postoperative band, the risk of recurrent deformity in these patients is believed to be significantly greater, however. If the surgeon or craniofacial team does not have the ability to create an external band, this procedure should not be offered to the patient. The ability to use the endoscopic technique is based on age and the type of craniosynostosis. The endoscopic repair requires that the surgeon perform the operation before 4 months of age. The reason for this is as follows: First, the endoscopic procedure demands that the bone be thin enough to allow an osteotomy to be made with endoscopic shears or bone cutters. In an older child who has increased calcification throughout the calvarium, modern endoscopic instruments cannot cut through the bone. Perhaps as endoscopic laser bone-cutting techniques are developed, this will be less of a problem, but currently, in patients past 4 months of age, most endoscopic shears and bone cutters physically cannot make the osteotomy. The second factor in terms of age is the bleeding potential of the child. Children under 4 months of age have not developed a significant amount of cancellous space between the two cortices of the inner and outer tables of the skull. As a result, bleeding that is produced from cutting the bone is significantly less in this younger age group [8]. When timing surgery, one should attempt to be past the physiologic nadir of a hematocrit, which normally occurs in the neonatal period. The author also routinely gives recombinant erythropoietin at a dose of 600 IU/kg/wk for the 3 weeks before surgery. This practice builds up the preoperative hematocrit and further decreases the risk of needing an intraoperative blood transfusion. The last age-related component is that the skull must be malleable and in a rapid-growth phase at the time of surgery because of the dependence of the surgery on an external molding band for success. These bands are mostly passive devices that work best on an actively growing skull. Although band therapy for deformational plagiocephaly is effective up to 18 months of age, greater effects are seen when the helmet is used earlier. This is particularly important in the treatment of coronal or lambdoid craniosynostosis, because a normalization of the cranial base by the helmet is also required if the surgery is to be considered a success. In the author’s opinion, cranial base remolding is most effective when generated at a young age. The author initially limited endoscopic cranial vault remodeling to sagittal synostosis because the patients typically have minimal ocular involvement in the deformity (Fig. 2A–F). This technique has been used on various suture fusions with equal success. Corrective changes in the orbital position and cranial base shape are seen after the reconstruction because of the continued use of the band. The author uses the technique as a first part of a two-staged repair on multisutural fusions (Fig. 3A–L). The endoscopic approach and band are used for the initial release, and then a standard cranial vault is performed at 1 year of age to complete the reconstruction when necessary. In some cases, the planned secondary operation is not required.
Surgical method The surgical technique described herein is for the treatment of sagittal craniosynostosis; however, the basic principles are the same, regardless of the location of the suture fusion (Fig. 4A and B).
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Fig. 2. Patient with sagittal suture craniosynostosis treated with an endoscopic repair. (A–C) Preoperative anteroposterior, lateral, and vertex views of patient showing the scaphocephalic appearance of the skull. (D–F), Postoperative anteroposterior, lateral, and vertex views of the same patient showing improved skull shape status after endoscopic repair. (G) Lateral view taken 2 weeks after endoscopic surgery, before the placement of a molding helmet. Note that even without the helmet there was a significant improvement in cranial bone contour. The scaphocephaly is decreased and the occipital bullet has been relieved. Without the molding band, however, the deformity is likely to recur.
Surgical technique for treatment of sagittal craniosynostosis is as follows: The patient is placed in the prone position, with the skull in a U-shaped headrest (Fig. 4C). The neurosurgeon and plastic surgeon then work together on the patient. Incisions of 2 cm are made just anterior to the anterior fontanel and just posterior to the occipital bullet (Fig. 4D). Dissection is performed first in a subgaleal plane to connect the two incisions. This is done with a Freer elevator and a specially designed curved dissector (KLS Martin, Jacksonville, FL, USA). Once the incisions are connected and the overlying scalp is freed, the endoscope is passed into the tunnel. The endocautery is used to coagulate any bleeding vessels. A Codman bur is used to create two holes in the skull on each side of the sagittal suture lateral to the sagittal sinus and
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anterior to the union of the two lambdoid sutures. Anteriorly, no bur holes are required if the anterior fontanelle is opened. If the anterior fontanelle, however, is fused, then additional bur holes are required in this area. The Kerrison bone rongeur connects the two burr holes taking extreme care not to disturb the underlying sagittal sinus (Fig. 4E). A #3 Penfield and Freer elevator is used to separate the dura in the midline and dissect down to the sagittal sinus. A small rongeur removes as much bone as possible under direct vision. This is performed for an area of
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Fig. 3. Complex, multisuture craniosynostosis patient treated with the endoscopic approach. (A–C) Three-dimensional CT scans demonstrate complete fusion of both coronal sutures and an anterior fusion of the sagittal suture. It should be noted that this scan was performed at birth, although the surgery was delayed until 2 months of age. By 2 months of age, the sagittal suture had fused completely. (D–F) Preoperative view of patient as the patient is being prepared for endoscopic surgery. Note the severe frontal bossing, the bitemporal narrowing, turricephaly, and scaphocephaly. (G–I) Postoperative CT scans taken immediately after surgery demonstrate the extent of the osteotomies used in the endoscopic repair. Even without the helmet there is an immediate improvement in shape. All the bone osteotomies were made through 1.5-cm ports. Only two ports were required. (J–L) Postoperative view of the same patient before Doc Band therapy. Note the small incisions and the immediate improvement in head shape.
up to 2 cm away from the incision with excellent visualization. This approach allows the creation of a large opening for the placement of the endoscopic camera and dissectors (Fig. 4F). After this procedure, the endocamera with a specialized retraction sheath (KLS Martin, Jacksonville, FL) is placed below the endocranial surface of the bone to help reflect down the dura. A specialized periosteal elevator with a curved tip (KLS Martin) dissects the dura away from the overlying fused sagittal suture until the anterior and the posterior portals are connected. Should the sagittal sinus be injured, the two incisions are immediately connected and the bone is removed with a Midas Rex craniotome, which is left on standby in the room for emergencies. The author has never used this Midas Rex but feels better taking the extra safety precautions.
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Once the dura over the sagittal sinus is dissected down off the fused sagittal suture, a 2.5-cm strip of bone is removed, including the entire fused sagittal suture. This is similar to the classic strip craniectomy procedure. The bone is physically removed through the incisions and is not replaced. If the strip of bone that is removed is larger than the skin opening, then the bone is cut down its middle to decrease its width. Once the sagittal segment of bone is removed, attention is directed toward creating barrel stave osteotomies laterally and freeing the occipital and frontal areas (Fig. 4G). A 5-mm strip of bone is removed anterior to each of the lambdoid sutures. Another 5-mm strip of bone is removed anterior to each of the coronal sutures. The endoscope dissects the dura laterally in the temporal and parietal regions. A curved Mayo scissor and a curved bone cutter (KLS Martin) are used to create complete, barrel stave osteotomies from the area of the strip craniectomy down into the mid-temple region. A blunt dissector is used to outfracture each of these barrel stave osteotomies in a Greenstick manner to widen the cranium and increase the cranial index. If there is a large occipital bullet, then the endoscope is used to dissect posteriorly and completely osteotomize the occipital bullet from the surrounding bone. Once the occipital bullet is free floating, anteroposterior compression of the skull is permitted.
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Fig. 4. Endoscopic surgical repair technique for sagittal craniosynostosis. (A) Vertex view showing the locations of the osteotomies used in the endoscopic bone resection. (B) Lateral skull drawing demonstrates the lateral extent of the bone remodeling. Note that the barrel stave osteotomies extend all the way down to the cranial base. (C) Preoperative view of skull with biodrape wrapping in place, which decreases the need to remove all the hair from the patient. (D) Anterior scalp incision and port. The port size is only 1.5 cm in length. The incision is made in the anteroposterior direction. The periosteal elevator is used to dissect the scalp away from the bone in the subgaleal plane. (E) A Kerrison rongeur is used to connect the two bur holes made on each side of the fused sagittal suture to avoid damage to the sagittal sinus. (F) A rongeur is used to remove a 2-cm circle of bone before using the endoscopic equipment. (G) Endoshears and endobone cutters are used to make the lateral, anterior, and posterior osteotomies. (H) Drawing of dura being dissected off the endo-cranial skull surface with the endoscopic technique. (I) Drawing of the lateral barrel stave osteotomies being performed using the endo-bone cutters. The endoscope ensures that only the bone is being cut, and that the underlying dura is protected.
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If there is a significant amount of narrowing in the temple region, an additional barrel stave osteotomy is performed in the frontotemporal bone to widen this area, which may necessitate the endoscopic elevation of the temporalis muscle in the subperiosteal plane to completely free up the bone. No bone is removed in this area, and osteotomies are created using the bonecutting endoscopic shears (KLS Martin). All other areas of the bone are outfractured laterally to widen the cranial vault and normalize cranial index. A flat Penrose drain is placed through a separate stab incision posteriorly. If any bone bleeding is present, bone wax is placed under direct visualization or through the use of a blunt endoscopic
Fig. 5. Type of Doc Band used in postoperative molding. Lateral view of the active molding band used to correct scaphocephaly. This band has elastics attached to the side to compress the skull in the anteroposterior direction. The band is relieved weekly in the temporal region to allow widening in this area, which normalizes cranial index.
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dissector. Incisions are closed with resorbable sutures and the patient is extubated at the end of the case. After a 2-day stay in the intensive care unit, patients are discharged home wearing a 4-inch bandage wrap. This wrap decreases the postoperative swelling and begins the external remodeling process. At the end of the second postoperative week, the patient is casted for the external molding helmet. He or she returns 1 week later for the first fitting. The helmet is adjusted weekly for the next 4 months to optimize cranial shape. An active anteroposterior compression helmet with two rubber bands on each side of the band is used when treating patients with sagittal craniosynostosis (Fig. 5). This active pressure significantly decreases anteroposterior length and rapidly normalizes the cranial index. At the end of 4 months, a second passive helmet can be applied on selected patients. When treating nonscaphocephalic forms of craniosynostosis, only this passive device is used.
Summary We are entering a new era of craniosynostosis repair. When detected early, endoscopic skull remodeling, combined with a postoperative external skull-molding device, gives an excellent long-standing reconstruction of the cranial skeleton. This technique diminishes the morbidity of the operation and decreases the overall cost. It does not replace classic plate and screw cranial vault reconstruction in the older patient but is a useful weapon in the armamentarium of the craniofacial surgeon for the treatment of craniosynostosis in the neonatal period.
References [1] Jimenez DF, Barone CM. Endoscopic craniectomy for early surgical correction of sagittal craniosynostosis. J Neurosurg 1998;88:77–81. [2] Barone CM, Jimenez DF. Endoscopic craniectomy for early correction of craniosynostosis. Plast Reconstr Surg 1999;104:1965–73. [3] Olds MV, Storrs B, Walker ML. Surgical treatment of sagittal synostosis. Neurosurgery 1986;18:345–7. [4] Panchal J, Marsh JL, Park TS, et al. Sagittal craniosynostosis outcome assessment for two methods and timings of intervention. Plast Reconstr Surg 1999;103:1574–84. [5] Littlefield TR, Beals SP, Manwaring KH, et al. Treatment of craniofacial asymmetry with dynamic orthotic cranioplasty. J Craniofac Surg 1998;9:11–7. [6] Kelly KM, Littlefield TR, Pamatto JK, et al. Cranial growth unrestricted during treatment of deformational plagiocephaly. Pediatr Neurosurg 1999;30:193–9. [7] Stelnicki EJ, Hoffman W. Intracranial migration of microplates versus wires in neonatal pigs after frontal advancement. J Craniofac Surg 1998;9:60–4. [8] Johnson JO, Jimenez DF, Barone CM. Blood loss after endoscopic strip craniectomy for craniosynostosis. J Neurosurg Anesthesiol 2000;12:60.