DATE OF OPERATION: MM/DD/YYYY
PREOPERATIVE DIAGNOSIS: Bihemispheric parafalcine meningioma, left greater than the right.
POSTOPERATIVE DIAGNOSIS: Bihemispheric parafalcine meningioma, left greater than the right. Frozen section consistent with meningioma.
OPERATION PERFORMED:
1. Left frontoparietal craniotomy, parasagittal, resection of tumor (complex).
2. Stealth neuronavigation, frameless stereotaxy for preoperative planning and volumetric resection.
3. Use of operating microscope for microdissection.
SURGEON: John Doe, MD
ASSISTANT: Jane Doe, PA-C
ANESTHESIA: General.
COMPLICATIONS: None.
DESCRIPTION OF OPERATION: After informed consent was obtained from the patient following extensive discussion of risks and benefits of surgery, the patient was taken to the operating room where he was placed in the supine position upon the operating room table, and all pressure points were padded. Adequate general anesthesia was induced and maintained with a combination of intravenous and inhalational agents. The patient’s head was secured in Mayfield three-pin headholder. The scalp overlying over the frontoparietal regions bilaterally was prepped, shaved, and prepared with DuraPrep solution and draped in the usual sterile manner with an iodine-impregnated adhesive sheet placed over all areas of exposed skin. Intravenous cephazolin was administered for perioperative prophylactic antibiotic coverage. Intravenous dexamethasone was given as a neuroprotective agent. Intravenous mannitol was administered to facilitate brain relaxation.
The stealth neuronavigation system was registered and the accuracy confirmed using anatomical landmarks. This assisted in planning above the craniotomy flap. A proposed scalp incision, inverted in U-shape crossing the midline, was fashioned over the left frontoparietal region. This encompassed the extents of the tumor. This region was infiltrated subcutaneously with 1% lidocaine with 1:100,000 epinephrine.
The skin incision was created with #10 scalpel blade. The incision was carried through the skin, subcutaneous tissues, galea aponeurotica, pericranium until the calvarium was encountered. The soft tissue flap was elevated. Two Raney hemostatic clips were placed on the skin edges, the scalp edges. The soft tissue flap was protected in a saline moistened 4 x 4 sponge and retracted using fishhooks and rubber bands over Ray-Tec fluffs.
The stealth neuronavigation system was again utilized to plan an appropriate free calvarial flap. The superior sagittal sinus was identified using stealth station corresponding to the old sagittal suture. The extents of the planned flap were marked. Using a craniotome, bur holes were created on either side of the superior sagittal sinus in the frontal region at the anterior aspect of the flap and on either side of the midline on the parietal region, the posterior aspect of the exposure. The dura was gently separated from bur hole to bur hole anteriorly and posteriorly respectively over the sagittal sinus to ensure the dura was free here.
A free calvarial flap was then fashioned using Midas Rex high-speed air drill using a B1 Arthrotec attachment. The calvarial flap was elevated using Cushing periosteal elevators. The superior sagittal sinus remained intact with no significant bleeding encountered. Epidural rolls of Oxycel were placed around the margins of the calvarial flaps directly over the sinus. Dural tack-up sutures were placed circumferentially.
The dura was opened based upon superior sagittal sinus with great care taken to avoid trauma to the underlying cortical surface. The dura was gently reflected. Bridging veins were identified extending from the cortical surface to the superior sagittal sinus. These were preserved in all cases.
The operating microscope was then brought into the field. Under high-powered magnification, the frontal most aspect of the tumor was exposed, where the tumor extended to the sagittal sinus. The frontal lobe was gently retracted laterally, again taking great care to avoid trauma to the bridging venous structures. A dural-based tumor was encountered, arising from the left side of the falx. The margins of the tumor were gently and progressively exposed, although the tumor itself was debulking internally, allowing mobilization of the capsule circumferentially. The tumor itself was somewhat vascular and calcified and quite firm. Cavitron Ultrasonic aspirator was utilized to the bulk of tumor internally. This allowed progressive mobilization of the capsule. The plane between the capsule and the cortical surface was protected using cottonoid strips. Resection continued until the entire left-sided tumor was resected. No significant vascular structures were sacrificed.
The falx was then transected with assistance of the stealth neuronavigation system to allow access to the right-sided tumor. The tumor was identified and resected in similar fashion using the Cavitron Ultrasonic aspirator to achieve internal debulking and with mobilization of the capsule circumferentially.
Once maximal tumor resection had been achieved, the wound was irrigated with copious normal saline irrigant, and meticulous hemostasis was assured. The resection cavity was lined with Surgicel. Hemostasis was rechecked using Valsalva maneuver. The dura was then reapproximated in watertight fashion using 4-0 nylon running suture. The subdermal space was filled with saline irrigant prior to frontal closure. Surgicel was placed over the exposed sinus. Of note, throughout the resection and as long as the interdural space was exposed, the cortical surface was covered with Vicryl, as was the sagittal sinus and dura and all exposed bridging veins to prevent desiccation and possibly thrombosis. The epidural space was filled with Gelfoam sheath. The covered flap was replaced and secured with Synthes cranial plates and screws.
The wound was irrigated again with saline irrigant. The galea aponeurotica was closed with 2-0 Vicryl simple interrupted inverted suture and the skin with surgical staples. Sterile dressings were applied over the wound. The perioperative drapes were taken down, general anesthesia reversed, and the endotracheal tube withdrawn. The patient was subsequently transported to the postanesthesia care unit for postoperative monitoring. Estimated blood loss was 200 mL. Sponge and needle counts were correct x2. The patient tolerated the procedure well, and there were no intraoperative complications.
