In lambdoid synostosis there is ipsilateral occipital flattening with a compensatory mastoid bulge, and compensatory vault expansion on the opposite side. The goal of surgery is to release the fused suture, and make the cranial base symmetric. The mastoid bulge cannot be corrected due to its low position.
2. Positioning and approach
With the patient in a prone position with a horseshoe head rest, the exposure of the posterior half of the skull is made via a coronal incision.
After exposure of the posterior cranial vault, a craniotomy of the occiput and the parietal regions is outlined.
Burr holes are first placed at periphery of the flap. An epidural dissection between these points is made.
The neurosurgeon then completes the osteotomies using a craniotome.
4. Reshaping and fixation
Reshaping of the basal occipital bone
After the bone flap is removed, the dura is freed from the anterior and middle fossae in the epidural plane.
The dura is protected with neurosurgical cottonoids.
Malleable retractors are used to retract and protect the dura when performing the osteotomies.
On the involved side barrel-stave osteotomies with out-fracturing are made. The newly positioned barrel-staves may be left to float or are stabilized with a long resorbable plate.
Alternatively to barrel-stave osteotomies, an occipital segment can be cut and advanced posteriorly. The segment is secured with resorbable plates.
Reshaping of the occipital flap
This typically involves splitting the bone longitudinally and bending and shaping the two segments, placing the right piece on the left side and vice versa. However the segments can also be replaced in their original position and rotated.
The principle is to make the involved side more rounded and full, slightly overcorrected but generally symmetric with the opposite side.
The segments are secured with resorbable plates and screws, wires, or sutures.
5. Aftercare following transcranial and Le Fort III procedures in infants and children
Most surgeons favors placement of a bulb suction drain under the scalp for 3-5 days. Resorbable skin sutures are often used.
A circumferential head dressing is utilized for 48 hours. The neurosurgeon may request placement of a lumbar drain if significant dural tears have occurred during surgery. Patients should spend at least 1-2 days in an intensive care unit for neurological monitoring.
Keeping the patient’s head in an upright position postoperatively may significantly improve periorbital edema and pain. Some surgeons use injectable corticosteroids during surgery to reduce periorbital swelling.
To prevent orbital emphysema, nose-blowing should be avoided for at least 10 days.
The following perioperative medications are controversial. There is little evidence to make strong recommendations for postoperative care.
Avoidance of aspirin or nonsteroidal antiinflammatory drugs (NSAIDs) for 7 days.
Analgesia as necessary.
Antibiotics (many surgeons use perioperative antibiotics. There is no clear advantage of any one antibiotic, and the recommended duration of treatment is debatable.).
Nasal decongestant may be helpful for symptomatic improvement in some patients.
Steroids may help with postoperative edema. Some surgeons have noted increased complications with perioperative steroids.
Ophthalmic ointment should follow local and approved hospital protocol. This is not generally required in case of periorbital edema. Some surgeons prefer it. Some ointments have been found to cause significant conjunctival irritation.
Regular perioral and oral wound care has to include disinfectant mouth rinse, lip care if intraoral incision has been used.
Postoperative examination by an ophthalmologist may be requested, although sever periorbital edema may prevent useful assessment. The following signs and symptoms are usually evaluated:
Postoperative imaging has to be performed within the first days after surgery to verify accuracy of surgery. 3-D imaging (CT, cone beam) is recommended.
Remove sutures from skin after approximately 7-10 days if nonresorbable sutures have been used. Apply ice packs for the first 12 postoperative hours as able although infants and young children do not tolerate this well (may be effective in a short term to minimize edema). Avoid sun exposure and tanning to skin incisions for several months.
Soft diet can be taken as tolerated until there has been adequate healing of any maxillary vestibular incision. In children and infants age appropriate diets are then prescribed. Patients in MMF will remain on a liquid diet until such time the MMF is released.
Clinical follow-up depends on the complexity of the surgery, and whether the patient has any postoperative problems. Most patients are discharged at postoperative day 3-5 and seen again in 2-3 weeks.
In patients undergoing monoblock or Le Fort III distraction, distraction typically begins at day five at 1 mm/day and is assessed weekly with plane radiographs and clinical examination until the desired position is reached. After advancement a period of consolidation of 1-3 months is recommended before the retractors are removed.
In patients undergoing conventional advancement with intermaxillary fixation, MMF is kept in place for 4-6 weeks. Routine oral hygiene is prescribed. Patients with arch bars and/or intraoral incisions and/or wounds must be instructed in appropriate oral hygiene procedures. The presence of the arch bars or elastics makes this a more difficult procedure. A soft toothbrush (dipped in warm water to make it softer) should be used to clean the surfaces of the teeth and arch bars. Elastics are removed for oral hygiene procedures. Chlorhexidine oral rinses should be prescribed and used at least 3 times a day to help sanitize the mouth. For larger debris, a 1:1 mixture of hydrogen peroxide/chlorhexidine can be used. The bubbling action of the hydrogen peroxide helps remove debris. A Waterpik® is a very useful tool to help remove debris from the wires. If a Waterpik is used, care should be taken not to direct the jet stream directly over intraoral incisions as this may lead to wound dehiscence.
The patient needs to be examined and reassessed regularly and often. Additionally, ophthalmological, ENT, and neurological/neurosurgical examination may be necessary. If any clinical signs for meningitis or mental disturbances develop, professional help has to be sought. Due to the young age of many patients, routing CT-scans are performed only if clinically indicated to avoid excessive radiation exposure.