DATE OF OPERATION: MM/DD/YYYY
PREOPERATIVE DIAGNOSIS: Left cerebellar cavernoma.
POSTOPERATIVE DIAGNOSIS: Left cerebellar cavernoma.
OPERATIONS PERFORMED: Left suboccipital craniectomy, resection of the cerebellar cavernous malformation, microdissection, intraoperative computer-assisted image guidance with BrainLAB navigation.
SURGEON: John Doe, MD
ANESTHESIA: General.
DESCRIPTION OF OPERATION: The patient was taken to the operating room, anesthesia was induced, and the patient was intubated uneventfully for left suboccipital craniectomy and above procedures. Foley catheter and arterial line were inserted and then the patient was placed in the supine position with the head rotated to the right.
The patient’s head was secured with a Mayfield headholder and a shoulder roll was placed under the left shoulder to provide adequate exposure over the occipital area. The localization of the head was then done using z-touch laser scanning and manual localization of the fiducial markers.
The location of the cavernous malformation was then checked at the level of the skin and the direction of approach was chosen through the retromastoid craniectomy. The left retromastoid area was then prepped and draped in the standard sterile fashion.
After application of local anesthetic, the straight incision was made behind the left ear and the soft tissues were dissected down to the bone. The hemostasis was achieved with application of Raney clips and bipolar coagulation, and once the bone was exposed, the monopolar coagulation and periosteal elevators were used to expose the bone.
The hemostasis from the bone was achieved with bone wax and the self-retaining retractor was inserted.
The craniectomy was then performed using a high-speed drill. An opening in the bone was created measuring about 1.6 x 2.0 cm. Once the bone was removed, hemostasis from the dura was obtained with bipolar coagulation.
The dura was then sharply opened with a 15-blade knife and Metzenbaum scissors and dural flaps were retracted in different directions. The surface of the cerebellum was exposed, and then by application of a piece of Adaptic, we drained the cerebrospinal fluid from the cerebellopontine angle and that allowed the cerebellum to decompress.
The arachnoid membrane overlying the lower part of the cerebellopontine angle was sharply opened. As soon as the cerebellum was exposed, the operative microscope was brought into the field and the rest of surgery was performed with magnification of operative microscope using microsurgical technique and microsurgical instruments to dissect the brain, cranial nerves, and vascular structures.
Once the lower cranial nerves were exposed, the arachnoid membrane was sharply opened to avoid retraction of the nerves, and then using intraoperative image guidance system, location of the cavernous malformation was checked. The malformation was found in a depth of the left cerebellar hemisphere, and by gentle dissection of the cerebellar tissue, we exposed initially discolored gliotic tissue around the lesion, suggestive of multiple bleedings in that area, and then the cavernous malformation itself was exposed.
We performed circumferential dissection around the malformation and then the malformation was sharply opened and its contents were removed with Takahashi forceps in a piecemeal fashion. The capsule over the cavernous malformation was then removed as well. We performed dissection circumferentially and were able to remove the cavernous malformation capsule completely. A large vein that was seen on preoperative imaging was identified slightly posterior to the malformation. It was completely preserved and we did not have to sacrifice it.
Once the cavernous malformation was completely removed, the hemostasis in the malformation bed was obtained with low bipolar coagulation and then a small piece of Gelfoam with thrombin was placed into resection cavity. The subsequent irrigation with saline solution showed no evidence of ongoing bleeding or oozing and the resection of malformation was considered completed. The malformation tissue was sent to the pathology lab for routine investigation.
Once the resection was completed, the area was inspected. The pieces of Adaptic that were placed on the surface of cerebellum were gently removed and then the sutures holding dura in place were opened. A small piece of DuraGen dural substitute was placed over the dura opening and that provided watertight closure of the dural defect.
The retractor was then removed. The soft tissues were approximated and closed in multiple layers. The muscles and subcutaneous tissues were closed with interrupted 2-0 Dexon and then the skin was closed with running nylon.
Once the closure was done, the incision was cleaned with solutions of peroxide and Betadine and a sterile dressing was placed over the incision. The patient was then removed from the headholder, awakened from anesthesia, and extubated uneventfully.
There were no complications during the surgery. The patient tolerated the procedure well. Estimated blood loss was about 25 mL. Counts of needles, instruments, and sponges reported as correct.
