Introduction
As with any other surgical operation, adequate preparation and planning prior to performing the procedure are crucial and paramount to obtaining an excellent result and minimizing complications. In the case of minimally invasive procedures with small incisions and narrow working corridors, said planning and preparation play an even more important role. This chapter will detail a number of principles that are common to all of the different procedures for treating craniosynostosis with endoscopic techniques.
Diagnostic Imaging
Diagnosis of single suture, isolated, nonsyndromic craniosynostosis can be made purely on physical examination and remains a clinical diagnosis. As such, we believe that obtaining imaging is not an absolute necessity to make the diagnosis, although it can corroborate it. It has been our center’s approach not to expose the young infants to unnecessary radiation associated with computed tomograms (CT) and particularly with the protocol required to do three-dimensional (3-D) reconstructions. Each suture synostosis leads to the development of a very specific and characteristic phenotype, which can be easily diagnosed. Plain radiographs of the skull are used sparingly and particularly in situations where associated positional deformational forces (as seen with certain sleeping patterns and/or with torticollis) lead to unusual head shapes. We reserve the use of CT scans to situations: (a) when the diagnosis cannot be easily determined with physical examination; (b) when there is presence or suspicion of multiple suture synostosis; or (c) if the patient has a syndromic phenotypic presentation.
Diagnostic Labs
With an otherwise normal infant, it has been our decades-long policy not to obtain any serum or blood work prior to surgery. If the birth, family, and developmental history indicate no abnormalities, the likelihood of an abnormal blood volume and/or composition with negative or severe consequences is extremely low. The only laboratory value that is obtained prior to commencing the surgical procedure is a hemoglobin and hematocrit (H/H) level either via direct venipuncture, heel stick, or with an I-STAT handheld blood analyzer. A more extensive and detailed blood work is obtained as indicated by family history (i.e., von Willebrand disease or other coagulopathy). In our experience with over 800 patients, only two infants were ultimately found to have rare blood abnormalities. Upon completion of surgery, an immediate postoperative H/H is obtained, and a third one on the next morning. The immediate postoperative H/H has been found to be a very reliable predictor of blood loss and for the need for postoperative blood transfusions. Upon completion of surgery, extreme care is taken to make sure that all bony, scalp, dural, and epidural bleeding is stopped and controlled. As such, the immediate postoperative H/H is a very reliable indicator of the patient’s red blood cell load and typically drops very little, and usually by no more than a gram per deciliter. In the last 24 years of treating these patients, we have not had the need to readmit and transfuse any patient who was discharged with a hematocrit of 15% or greater, nor have the patients had any consequences because of this management approach.
Ophthalmologic Evaluation
Our center’s pediatric ophthalmologist evaluates all of our patients prior to surgery and evaluates for abnormalities that may be present in the retina, vitreous, lens, cornea, muscular abnormalities, or orbital imbalance. A full ophthalmological evaluation takes place 1 or 2 days prior to surgery. Postoperative follow up evaluations are done within 6 months and 1 year. Autorefraction before and after pupillary dilation is done with Plusoptix or Retinomax vision screener to measure refractive errors such as myopia, astigmatism, or hyperopia. Cycloplegic refraction is done with streak retinoscopy to measure and quantify refractive errors and diagnose amblyopia. The eye movement, position, and presence of strabismus are done with each evaluation. Indirect ophthalmoscopy is used to examine the optic nerve, retina, and retinal vasculature. External eye examination and photographs are done to assess proptosis, enophthalmus, orbital rim symmetry, and widening or narrowing of the palpebral fissure. ReTCam or PanoCam digital images of the fundus are obtained, which provide true-color high-resolution images of the optic nerve and retina.
Anthropometric Evaluation
All of the patients undergo extensive cranial anthropometric evaluation and analysis using OrthoAmerica’s StarScanner. This device scans the patient’s head using nonionizing, infrared technology to produce 2-D and 3-D scans with a large number of data points ( Figs. 4.1 and 4.2 ). A baseline preoperative scan is done a day or two prior to surgery. On the fourth postoperative day, the patient is scanned and data is obtained and sent to the OrthoAmerica’s Orlando manufacturing plant for design, creation, and primary modification of the cranial orthosis. The orthosis is then delivered overnight and the final modifications are locally made prior to final fitting. I personally assess the patient and orthosis for a final check. If further modifications are deemed necessary, they are made prior to instituting an ongoing wear schedule. Once the helmet is outgrown (usually 8 to 10 weeks for young infants under 3 months of age), the process is repeated until the conclusion of the orthotic therapy several months later. Specific details on orthosis manufacturing and management will be given in Chapter 15 .
Surgical Set-Up
For all cases, the patient is positioned 180 degrees from the anesthesiologist. All of the supportive instrumentation is set to the left of the patient to include the monopolar, bipolar, and suction units. The endoscopic tower with camera, light, and cables is also located on the left, as well as the drills. The surgeon and assistant are situated at the head of the table and the surgical technician and the instrument and back tables are located to the right of the patient. Once sterile draping is done, the instrument pouch on the right holds the suction, monopolar, and suction coagulator. The instrument pouch on the left of the patient’s head holds the second suction bipolar and endoscopic sponge, with Fred antifog solution (McKesson, Richmond, VA). Two Mayo stands are situated over the patient’s feet. The Mayo on the left holds the heavier instruments: endoscopes, drills, and electric rasp. The Mayo stand on the right holds all of the instruments used to do the procedure ( Fig. 4.3 ). A towel wrapped with Ioban (3M, St. Paul, MN) is placed on the middle of the field and holds the Cottonoids and Gelfoam of different shapes and sizes. This set up has maximal ergonomic organization and simplicity.
Surgical Instrumentation
The overall instrumentation/surgical set up for these cases is relatively simple and straightforward. The majority of the instruments are found in most operating rooms and surgical supply rooms ( Fig. 4.4 ). These include monopolar electrocautery units utilizing a needle tip, which is set at 15 watts on the cut mode and 20 watts for the coagulation mode. The needle tip on the cut mode is utilized to incise the dermis followed by the coagulation mode, which is used for deeper subdermal tissue dissection in a bloodless fashion. Besides the scalp, the skull and particularly the diploë are the primary sources of bleeding, given their vascularity. As such, control of bone bleeding is of utmost importance to minimize overall blood loss intra- and postoperatively. This bleeding is easily controlled with the use of a suction coagulator ( Fig. 4.5 ) (Valleylab, Valley Forge, PA). This unit is connected to the bovie monopolar unit (ValleyLab) and set at 60 watts on the coagulation mode. The insulated stem has an uninsulated ring tip, which delivers the coagulating energy, whilst the inner suction tube continuously aspirates blood to keep the surgical field dry. The suction coagulator is applied to the bleeding bone until the bleeding stops and the bone fully coagulated. This maneuver leaves the bone edges black and charred. As new bone growth (which is membranous in nature) comes from the dura matter, the bone coagulation does not interfere with new bone growth. There has not been a single case of bone infection or osteomyelitis in our case series of over 800 cases. We strongly believe that this level of osseous coagulation during surgery is the primary reason for our lack of postoperative bleeding and the lack of postoperative hematomas or need for reoperations to remove such hematomas. Coupled with the generous use of Surgiflo (Ethicon, New Brunswick, NJ) and Thrombin Topical liquid, bleeding from the surgical site is minimized. The use of coagulation on the dura is kept to an absolute minimum, as its use can lead to postoperative cranial defects and lack of proper ossification. Every effort must be made to minimize damage to the osteoprogenitor dural cells during hemostasis. Whenever dural bleeding is encountered, Surgiflo can be used to stop the bleeding in an atraumatic fashion along with liquid Thrombin and Gelfoam (Pharmacia and Upjohn, New York, NY).
