Endoscopic strip craniectomy (ESC) with postoperative helmet orthosis is a well-established treatment option for sagittal craniosynostosis. There are many technical variations to the surgery ranging from simple strip craniectomy to methods that employ multiple cranial osteotomies.
It was proposed in 1998 by D. Jimenez and C. Barone 1).
Advantages are reduction of the blood loss caused by conventional reconstruction, reduction of the incision size, surgery duration, and hospital length of stay.
Supine position with the head flexed forward to a maximum possible angle.
It is most convenient to use the main endoscopic instrumentation for a patient lying in this position.
C-shaped silica gel head supports to ensure convenient head positioning. This provide a sufficient level of head fixation in the proper position. An important issue is prevention of bed sores and injuries from surgical electrodes. For this purpose, disposable sticky electrodes that ensure the maximal contact surface area with child’s skin and isolation can be used.
Another important thing is to control of child’s body temperature. Various body warming systems can be used to maintain the normal body temperature.
An important step in preparing for the surgery is to mark the surgical site.
A median cranial line (a projection of the sagittal sinus), the coronal suture, anterior fontanel (if it is present), and external occipital protuberance are used as the main landmarks.
Proper fixation of the surgical clothing is needed to prevent overlying and traction of the soft tissues in the projection of intervention, to prevent restriction of freedom of surgeon’s actions.
The next step of the surgery is the installation of a special mounting system with adapters for retractor.
Skin incision is made 1.5–2 cm posterior from the coronal suture or anterior fontanel (if it is not closed).
The possible damage to the large terminal branches of the superficial temporal artery should be avoided to prevent intense bleeding.
An additional incision can be made in the projection of the point at the intersection of the lambdoid suture and median (sagittal) line. S-shaped incisions can be made instead of linear incisions due to fact that they are more cosmetic and can be better hidden under hair.
Bone resection can be performed by the subperiosteal method.
The periosteum is stripped with a common raspatory in the incision projection by 1.5–2 cm in the anterior direction to visualize the coronal suture, which is a jagged line in front of the pathological sagittal suture. It can also be projected as a diagonal of the rhombus of the anterior fontanel perpendicular to the sagittal line and can be used as an additional landmark. It is extremely important to avoid damaging skin when using raspatories.
The periosteum is detached in the projection of the sagittal suture and at 3–4 cm to the sides, as well as in the projections of the coronal and lamdoid sutures on both sides (3–4 cm wide).
No large-scale detachment of the periosteum is needed (it may cause additional hemorrhage). The stenosed sagittal suture is defined as an area with bone hyperostosis; its relief can be palpated; there is no broken line typical of the serrate suture at the conjunction of two bones.
A trephination aperture 0.5 cm in diameter can be made by 1.5–2 cm in the posterior direction from the coronal suture and 1.5–2 cm in the lateral direction from the sagittal line using a high-speed drill equipped with a special burr.
The cutting edge of the burr in proper position prevents damage to the scleromeninx.
After making the trephination aperture, the bone is punched using bone forceps in the incision projection. If the anterior fontanel is present, there is no need in perforating the trephination aperture. In this case the scleromeninx can be dissected from the bone in the projection of the anterior fontanel. An important action during the surgery is detachment of the dura mater from inner surface of bones in the craniotomy area. The dura mater is often rigidly attached near the cranial suture; quite large emissary veins are sometimes present. There is a risk of damaging the sagittal sinus when detaching the dura mater from the bone. Under endoscopic visualization, the sagittal sinus always has a medial position and appears as a long dome-like formation. Sometimes a low blood flotation can be observed due to pulsation of brain vessels. Under inner-side visualization, the surfaces of parietal bones in its projection protrude into the skull cavity. One should also bear in mind that in 76% cases the sinus has lateral protrusions (lacunas 2–4 cm and 1.5–2.5 cm wide). The most typical lacuna localizes in the parietal area near the medial edge of the central gyrus 2).
Additional difficulties when the dura mater is dissected emerge when anterior fontanel is present. In this case, fontanel tissues participate in fixation of the dura mater to bone edges. A Polenov guidewire and a Penfield dissector is used to detach the dura mater from bone. These tools are used in all cases to perform dissection at the area required for resection without damaging the dura mater. The dura mater is detached along all the sagittal, coronal and lambdoid sutures. Detachment of the dura mater near the skull base was performed using a raspatory with wide cutting edge under endoscopic control, since the dura mater here is rigidly attached to the bones. The subsequent manipulations are performed under endoscopic control.
Scalp structures in the projection of the resected suture were moved upward.
It is important to control the child’s head position. The most convenient is the endoscope position in a plane parallel to the bone suture and moving the operating unit along the suture during bone resection. Osteotomy was performed along the sagittal suture from its intersection with the coronal suture to the lambdoid suture; the average resection width was 3.57±1.38 cm. In order to obtain additional mobilization, paracoronal osteotomy was performed in several cases in a posterior direction from the coronal suture until the skull base with resection of a part of the greater wing of sphenoid bone and paralamboid osteotomy anterior to the lambdoid suture until its intersection with the parietotemporal suture at both sides.
Notably, there are no known landmarks today to define osteotomy borders. The sagittal sinus is used as a landmark to dissect the sagittal suture, but there are no clear landmarks for additional osteotomies. A special landmark to define the borders of additional bone resection was the greater wing of sphenoid bone. It was partially removed using a high-speed drill and a diamond burr.
The osteotomy area here is limited by posterolateral (temporal) surface of the greater wing of sphenoid bone. It is slightly concaved and is involved in the formation of a wall of the temporal fossa. The lower part of this surface is limited by the infratemporal crest. One needs to keep in mind that in 51% of cases, arteries localize in the osteal canal in the anteroinferior part of the sphenoid bone 3).
The hemorrhage is stopped by bipolar coagulation and applying bone wax. At this stage, an important advantage of rigid fixation and endoscopic control can be seen: the possibility to perform manipulations with both hands (bimanually). A point before the intersection with the parietotemporal suture was used as a landmark of the border when conducting paralambdoid osteotomy.
Hemostasis is another important problem. Hemostasis should be performed at each stage during the surgery. Bones of the cranial base and vault are characterized by a sponge structure and intense blood supply.
Large emissary veins often lead to the dura mater; coagulation is needed if they are revealed. Another important feature of venous component of the cranial vault is the presence of intraosteal venous system localized in the spongy bone layer together with the external (intracutaneous) venous system. These systems are tightly interconnected and interact with the deep venous system localized between the dura mater layers 4).
Bone wax and treatment of the bone edge using a high-speed drill with a diamond tip can be used to stop bone bleeding. Another well-known technique is the use of an aspirator with bipolar coagulation. The use of this tool allows one to stop bone bleeding. However, when using it in hemostasis it is extremely important not to damage and not to coagulate the dura mater; a brain spatula is used to protect it. This method is of best choice in the youngest children, when bones are thin. It is also possible to use such hemostatic agents as SURGIFLO Hemostatic Matrix (Ethicon LLC). Hemostasis is performed under the endoscopic control. An endoscopic retractor is removed after the hemostasis was thoroughly performed. Only resorbable material is used for sealing due to the small size of incision, low tissue mobility in this area, and good healing. The wound is sealed with intracutaneous sutures; the surface is treated with sterile medical glue Dermabond Pro Pen (Ethicon LLC, USA) (Fig. 7). Wound condition is monitored during the hospitalization period. The mean duration of surgery for sagittal craniosynostosis was 163.3±43.25 min. Blood loss was 103.46±58.43 ml and increased with child’s age. Patients stayed in the Resuscitation Department for less than 1 day. Control CT followed by 3D skull reconstruction was performed 1–2 day after surgery. In all cases, no damage to the dura mater, sagittal sinus, air embolism were detected. Neither inflammation, nor infection complications, nor postoperative wound inconsistency were observed. There was no need for puncture in the intervention area. The length of a hospital stay after endoscopic cranioplasty was 3.1±0.5 days. Therefore, endoscopic surgical treatment of scaphocephaly was performed in 20 children. Treatment results were estimated after 1, 3 and 6 months in dynamic follow up according to the CT scanning followed by 3D reconstruction of the skull and anthropometric measurements. An orthotic helmet (“helmet therapy”) was used after regression of postoperative swelling of soft tissues in order to ensure additional correction of the head shape and for protection. The CT and 3D reconstruction data were used to calculate the cranial (cephalic) index for unbiased estimation of treatment results. In the dynamic follow-up after 6 months, the cephalic index was 77.29±4.17 (being 67.84±7.45 at hospitalization), which was considered to be an efficient outcome of intervention. These values, as well as the CT and 3D reconstruction data were used to determine the duration of wearing a helmet. The comparison of the preoperative cephalic index with the data from control examination revealed significant differences (U-test, p<0.01)
The possibilities of modern endoscopic tools and instrumentation allow one to perform successful surgical treatment for scaphocephaly. Endoscopic cranioplasty for correction of scaphocephaly is a low-invasion method to treat patients with this pathology.
In contrast to the conventional approaches, this method lowers the risks of complications connected with the volume of surgical interventions due to its low-invasiveness. Since the method is low-invasive, there is no need for long hospital stay 5).
An IRB-approved retrospective review was conducted on a consecutive series of cases involving ESC for sagittal craniosynostosis at 2 different institutions from March 2008 to August 2014. The patients in Group A underwent ESC and those in Group B had ESC with lateral barrel-stave osteotomies. Demographic and perioperative data were recorded; postoperative morphological outcomes were analyzed using 3D laser scan data acquired from a single orthotic manufacturer who managed patients from both institutions. RESULTS A total of 73 patients were included (34 in Group A and 39 in Group B). Compared with Group B patients, Group A patients had a shorter mean anesthetic time (161.7 vs 195 minutes; p < 0.01) and operative time (71.6 vs 111 minutes; p < 0.01). The mean hospital stay was similar for the 2 groups (1.2 days for Group A vs 1.4 days for Group B; p = 0.1). Adequate postoperative data on morphological outcomes were reported by the orthotic manufacturer for 65 patients (29 in Group A and 36 in Group B). The 2 groups had similar improvement in the cephalic index (CI): Group A, mean change 10.5% (mean preoperative CI 72.6, final 80.4) at a mean follow-up of 13.2 months; Group B, mean change 12.2% (mean preoperative CI 71.0, final 79.6) at a mean follow-up of 19.4 months. The difference was not statistically significant (p = 0.15). CONCLUSIONS Both ESC alone and ESC with barrel staving produced excellent outcomes. However, the addition of barrel staves did not improve the results and, therefore, may not be warranted in the endoscopic treatment of sagittal craniosynostosis 6).
The authors evaluated patients with nonsyndromic sagittal synostosis treated with either wide vertex suturectomy (4-6 cm) and barrel stave osteotomies (WVS+BSO) or narrow vertex suturectomy (NVS) (approximately 2 cm) between October 2006 and July 2013. Prospectively collected data included patient age, sex, operative time, estimated blood loss (EBL), postoperative hemoglobin level, number of transfusions, complications, and cephalic index. Fourteen patients in the NVS group were age matched to 14 patients in the WVS+BSO group. Descriptive statistics were calculated, and Student t-tests were used to compare prospectively obtained data from the WVS+BSO group with the NVS group in a series of univariate analyses.
The mean age at surgery was 3.9 months for WVS+BSO and 3.8 months for NVS. The mean operative time for patients undergoing NVS was 59.0 minutes, significantly less than the 83.4-minute operative time for patients undergoing WVS+BSO (p < 0.05). The differences in mean EBL (NVS: 25.4 ml; WVS+BSO: 27.5 ml), mean postoperative hemoglobin level (NVS: 8.6 g/dl; WVS+BSO: 8.0 g/dl), mean preoperative cephalic index (NVS: 69.9; WVS+BSO: 68.2), and mean cephalic index at 1 year of age (NVS: 78.1; WVS+BSO: 77.2) were not statistically significant. C
The NVS and WVS+BSO produced nearly identical clinical results, as cephalic index at 1 year of age was similar between the 2 approaches. However, the NVS required fewer procedural steps and significantly less operative time than the WVS+BSO. The NVS group obtained the final cephalic index in a similar amount of time postoperatively as the WVS+BSO group. Complications, transfusion rates, and EBL were not different between the 2 techniques 7).
Le et al, compared children with surgically corrected sagittal craniosynostosis to their age-matched control subjects to assess the longevity of their corrections. Furthermore, the outcomes of open repairs were compared with endoscopic repairs.Following institutional review board approval, three-dimensional photographs of patients who underwent surgical reconstruction for nonsyndromic sagittal synostosis were analyzed to determine biparietal and anterior-posterior diameter, circumference, cephalic index, cranial vault volume, cranial height, and forehead inclination. Thirteen patients who had undergone open repair, including 6 total cranial vault and 7 modified-pi procedure reconstructions, and 6 patients who had undergone endoscopic strip craniectomy with barrel-stave osteotomies and postoperative helmeting were compared with nonsynostotic age-matched control subjects. Mean follow-up was 97.5 months after open and 48.9 months after endoscopic repair. Student t tests were used for analysis. In the second arm of this study, 33 patients who had undergone endoscopic repair were compared with the 13 patients who had undergone open repair; mean follow-up was 24.8 months after endoscopic repair. Linear regression models were used to adjust for age and sex.After comparing three-dimensional photographs of children who were more than 3 years postoperative from surgical correction for sagittal synostosis with their age-matched control subjects, no statistically significant differences were found in any of the measured parameters. In addition, no differences were detected between open reconstruction versus endoscopic repair, suggesting equivalence in final results for both procedures 8).
The surgical management of infants with sagittal synostosis has traditionally relied on open cranial vault remodeling (CVR) techniques; however, minimally invasive technologies, including endoscope-assisted craniectomy (EAC) repair followed by helmet therapy (HT, EAC+HT), is increasingly used to treat various forms of craniosynostosis during the 1st year of life.
In a retrospective case-control analysis of 21 children who had undergone CVR and 21 who had undergone EAC+HT. Eligibility criteria included an age less than 1 year and at least 1 year of clinical follow-up data. Financial and clinical records were reviewed for data related to length of hospital stay and transfusion rates as well as costs associated with physician, hospital, and outpatient clinic visits. Results The average age of patients who underwent CVR was 6.8 months compared with 3.1 months for those who underwent EAC+HT. Patients who underwent EAC+HT most often required the use of 2 helmets (76.5%), infrequently required a third helmet (13.3%), and averaged 1.8 clinic visits in the first 90 days after surgery. Endoscope-assisted craniectomy plus HT was associated with shorter hospital stays (mean 1.10 vs 4.67 days for CVR, p < 0.0001), a decreased rate of blood transfusions (9.5% vs 100% for CVR, p < 0.0001), and a decreased operative time (81.1 vs 165.8 minutes for CVR, p < 0.0001). The overall cost of EAC+HT, accounting for hospital charges, professional and helmet fees, and clinic visits, was also lower than that of CVR ($37,255.99 vs $56,990.46, respectively, p < 0.0001).
Endoscope-assisted craniectomy plus HT is a less costly surgical option for patients than CVR. In addition, EAC+HT was associated with a lower utilization of perioperative resources. Theses findings suggest that EAC+HT for infants with sagittal synostosis may be a cost-effective first-line surgical option 9).
One hundred seventy-three patients (61 females and 112 males) were treated between July 2004 and March 2011 with endoscope-assisted strip craniectomy and postoperative helmet therapy (EASC + PHT). The mean operative time was 46.30 minutes. Eight (4.6%) of the 173 patients received blood transfusions. The average length of hospital stay was 1.35 days, with the majority of patients being discharged the day after surgery. All complications and any patient who required additional craniofacial reconstructions are discussed. In addition, a subgroup analysis was done for patients who had undergone surgery and had longer than 1 year of follow-up. The authors' growing database of patients supports the experiences described by others that early treatment of craniosynostosis with an EASC + PHT is a safe and efficacious technique. In addition, cost reduction due to decreased hospital stay and limitation of blood transfusions are demonstrable benefits associated with the use of this technique 10).