EVACUATE-pilot - Ultra-Early, minimally inVAsive intraCerebral haemorrhage evacUATion versus standard trEatment (EVACUATE)-Pilot phase

Positioning and planning Using standard of care volumetric imaging, a line is extended through the long axis of the clot to the nearest skull surface to maximize hematoma access in a single dimension while minimizing the traversed brain, and avoiding prominent vasculature and the corticospinal tract. Approaches must avoid eloquent brain regions including the primary motor and sensory cortices, language regions, and visual cortex. Stereotactic guidance must be used during the procedure for preoperative trajectory planning and intraoperative live navigation. Surgical Approach A linear incision is made in the skin and a high-speed or perforator drill is used to create a 1-2 cm diameter craniectomy. When the trajectory is not perfectly perpendicular to the skull, extra care must be taken to drill away a cylinder in the bone along the planned trajectory to maximize mobility of the sheath and endoscope within the craniectomy. Hemostasis is attained with bone wax, gel foam, and bipolar cautery. Prior to dural incision, ultrasound may be used to confirm the haematoma size and location for comparison after evacuation. The dura is incised and cauterized. The pia is incised. A brain biopsy may be performed for diagnostic purposes. The pia is then cauterized and hemostasis is achieved prior to passing the Surgiscope into the hematoma. The trajectory is planned such that the tip of the surgiscope obdurator will rest 1-2 cm from the distal end of the hematoma. The surgiscope is passed along the preplanned trajectory under live stereotactic guidance. The clear obdurator will show the red color of the clot as the surgiscope passes through it. The obdurator is then removed. The Aurora evacuator is introduced and clot is aspirated. Irrigation can be activated through the evacuator to improve visibility of the clot-brain border and to localize bleeding vessels. If a bleeding vessel is identified, bipolar cautery is used to cauterize the vessel under direct visualization. Given the inflammatory consequence of using thrombin in the cavity, the use of thrombin in the cavity is strongly discouraged. After hematoma is aspirated, reduced mass effect causes the surrounding brain to collapse inward and come into view at the end of the sheath. Once this occurs, the sheath is gently pivoted at the same depth to explore laterally to the sides of the hematoma cavity. Once the operator is convinced there is no remaining hematoma at that depth, the sheath is drawn back 1-2cm and the process is repeated. If, during this phase, a solid clot is encountered, the Aurora agitator is activated to digest more fibrous clot pieces. A large gauge suction and bipolar cautery may also be used if the Aurora evacuator is unable to aspirate a large clot fragment. After clearing all visible clots by withdrawing incrementally from the distal end of the hematoma, the cavity may be irrigated heavily with lactated Ringer’s solution to evaluate for residual clot fragments and active bleeding vessels. Assessment and closure After aspiration of all visible clots, the device is removed and the burr hole ultrasound may be used to assess for residual haematoma. The ultrasound may be helpful to reassess the degree of evacuation and settle any doubt about questionable regions seen through the surgiscope. An intraoperative CT is then performed to confirm that the goal of residual hematoma less than or equal to 15 ml or <50% of initial haematoma volume has been achieved. If the CT demonstrates that the residual clot volume is greater than 15 ml or >50% of initial haematoma volume then a second pass for additional clot removal is recommended (followed by an additional CT scan post procedure). A third pass is not recommended. Intraoperative CT scans can either be performed in operating room or angiography suite prior to closure or it can be performed in a traditional CT scanner with the operating room remaining sterile to permit return to the OR if the evacuation is not satisfactory. After completing the evacuation, hemostasis of the brain surface at the craniectomy site is confirmed. Dural substitute can be used at the preference of the surgeon. A titanium plate is used to cover the craniectomy defect and secured in place with titanium screws. The galea and skin are closed with sutures or staples per surgeon preference.