Minimally Invasive Endoscopic Procedure for Hematoma Removal from the Human Brain

Abstract

Source: Pan, J. et. al., Minimally Invasive Endoscopic Intracerebral Hemorrhage Evacuation. J. Vis. Exp. (2021)

This video demonstrates minimally invasive endoscopic hematoma removal, using a navigation-guided sheath and endoscopic aspiration with saline irrigation to preserve brain structure.

Protocol

All procedures involving human participants have been performed in compliance with the institutional, national, and international guidelines for human welfare and have been reviewed by the local institutional review board.

1. Positioning and Planning

1. Administer general anesthesia to the patient using standard techniques.
2. Maintain sterile conditions throughout the entire procedure by sterilely preparing the skin and draping the surgical area.
3. Plan the trajectory of the evacuation by using preoperative volumetric imaging to draw a line along the long axis of the hematoma to the outer surface of the skull, so that the tip of the sheath will sit 1 to 2 cm from the distal end of the hematoma.
   NOTE: Important things to keep in mind when planning the trajectory are to minimize disruption to brain tissue (especially eloquent structures) and avoid any vasculature visible on non-invasive imaging. Trajectory planning is performed on stereotactic navigation software, which varies by institution. A comparison of commonly used navigation systems in intracerebral hemorrhage (ICH) evacuation is available in the medical literature.
4. Place the patient in the correct anatomical position depending on the location of the hematoma.
   NOTE: Most cases (80%) are performed supine, and a minority are performed prone (15%) or supine with the head turned (5%).

2. Opening

1. Make a 2 cm linear, horizontal incision along the skin within a natural skin crease.
2. Open the skull with a 1- to 1.2 cm-diameter craniectomy using a high-speed drill with a 5 mm cutting burr. Attempt to align the craniectomy with the long axis of the hematoma, but avoid midline structures and eloquent brain territories.
   NOTE: A perforator is larger than necessary, especially if the defect is on the forehead.
3. If the trajectory is not perfectly perpendicular to the skull, drill a cylinder in the bone along the planned trajectory to ensure optimal mobility of the sheath and endoscope within the craniectomy, but be aware that the intersection with the dura will not be perpendicular.
4. Use bone wax, gel foam in thrombin, and bipolar cautery to achieve hemostasis.
5. Visualize the underlying hematoma using ultrasound to confirm its size and position.
   NOTE: Ultrasound quality is highest using the burr hole transducer in a wet field prior to durotomy.
6. Open the dura in a cruciate fashion and cauterize the dural leaves to within a millimeter of the bone edge.
   NOTE: Avoid large veins or arteries.
7. Incise the pia mater 1 cm with a #11 blade prior to cauterizing. If obtaining a brain biopsy, this is the ideal time. Use tumor forceps or the cup end of a Penfield 1 instrument. Avoid cautery until the biopsy is obtained.
8. Cauterize the pial incision and underlying cortex with bipolar cautery.

3. Phase 1 Evacuation

1. Insert the introducer sheath along the planned trajectory with a navigation stylet positioned within the sheath. The stylet provides live feedback on the location of the tip.
   NOTE: Given the small size of the 1 cm craniectomy, a "trans-sulcal" approach is often not possible; therefore, the pia is incised and entered in a non-vascular space immediately below the craniectomy.
2. If the clot is particularly fibrous and resistance is encountered, make a slight adjustment to the sheath to reach the target point.
3. Remove the introducer and navigation probe once the target point is reached, 1-2 cm from the distal end of the hematoma.
   NOTE: Some operators prefer to use stereotactic navigation registered to the endoscope rather than the sheath introducer for continuous navigation.
4. Note the position of the sheath by marking it at the level of the skin.
   NOTE: If the pressure within the hematoma is high, liquid may flow out of the sheath during this step.
5. Prepare the endoscope by activating the preferred settings, including white balance, brightness, filter, and light intensity.
6. Attach the irrigation tubing from a 2 L saline bag at shoulder height to the left working port and set the flow rate to approximately 25% on the endoscope. Open the right port of the endoscope all the way, allowing for the egress of irrigation fluid.
7. Insert the endoscope into the sheath. Insert the wand inside the working channel of the endoscope and hold the wand with the dominant hand.
   NOTE: For this phase of the procedure, maintain the endoscope and wand within the end of the sheath, approximately 0.5 to 2 cm from the end of the sheath.
8. Use the pointer finger to buffer the distance between endoscope and the wand's handle to maintain constant awareness of the location of the tip of the device within the sheath.
9. Set the suction strength of the aspiration system to 100% and set the irrigation flow rate to low (~25%).
10. Aspirate any liquid hematoma that presents itself at the end of the sheath while keeping the wand within the distal 1 cm of the sheath.
    NOTE: As the hematoma is aspirated, the cavity will collapse inward due to the reduced mass effect. Constant irrigation maintains the structure of the cavity during phase 2 of the evacuation.
11. If a solid clot is encountered that does not aspirate with suction alone, activate the bident within the wand to digest the clot.
12. If a piece of clot is too large or fibrous for suction and adheres to the tip of the wand, withdraw the entire endoscope and wand together with the clot, taking care not to dislodge the clot from the wand.
    NOTE: This is called the ADAPT (A direct aspiration first pass technique) technique, referencing the practice of removing intravascular thrombus during thrombectomy for acute ischemic stroke.
13. If the piece of clot is particularly large with a fibrous capsule and the prior two techniques do not work, use the working channel of the endoscope as an additional suction.
    1. To accomplish this, attach a conventional surgical suction to the second endoscope port (usually the irrigation outflow pathway) with the valve closed but ready for activation. Draw the large piece of clot into the end of the sheath using the wand. Close the irrigation inflow port and open the outflow port to activate maximal surgical suction. The clot is now stuck on the tip of the wand, endoscope, and sheath. Remove the wand, endoscope, sheath, and clot together.
       NOTE: This is called the double ADAPT technique.
14. If the clot has a fibrous capsule and is difficult to separate from the brain tissue, use the tip of the sheath as a blunt dissector.
    NOTE: This is called the sheath dissection technique.
15. After aspirating, explore the cavity at the same depth by gently pivoting the sheath laterally until no residual clot remains at that depth.
16. Withdraw the sheath 1 cm and repeat the aspiration steps of Phase 1 until the sheath reaches the proximal wall of the cavity.

4. Phase 2 Evacuation

1. Decrease the suction of the wand to 25% and increase the irrigation to 100% to improve visibility in the cavity. Explore for residual hematoma and identify bleeding arteries.
   NOTE: During this phase, it is critical to minimize suction forces on the pericavity brain tissue.
2. Aspirate any residual hematoma in a targeted fashion with low aspiration power, taking care not to damage surrounding brain matter, which can incur additional bleeding or cause trauma to the cavity wall.​
   NOTE: Blood products may initially interfere with optimal visualization, but the cavity will clear with the patient, continuous irrigation. If the cavity does not clear, identify and cauterize the bleeding vessels.
3. Monitor for any bleeding vessels and address them accordingly with the following steps:
   1. If small bleeding vessels are challenging to visualize, direct a consistent flow of irrigation towards the vessel by hovering immediately over the bleeding site with the sheath and pulling the scope back from the tip. Once the vessel is better visualized, cauterize the vessel.
      NOTE: This is called the sheath hover technique.
   2. Irrigate the cavity until hemostasis is achieved
   3. Apply pressure using the end of the sheath if pure irrigation does not work.
   4. Utilize bipolar cautery if the previous two methods do not work.
   5. Aspirate any residual hematoma along the sides or in the crevices of the cavity.
      NOTE: This step becomes easier once the bleeding vessels are addressed, permitting clear visualization.
4. Ensure that the cavity is cleared of all visible hematomas and bleeding vessels.
   NOTE: If there is a thin layer of fresh clot from intraoperative bleeding, beware of causing more bleeding in the attempted aspiration of this thin coating of fresh blood. Aspirate gently or leave the fresh blood in place. Differentiating clots from the cavity wall is a major challenge in the procedure.

5. Assessment and Closure

1. Withdraw the endoscope and sheath slowly, with the endoscope at the tip of the sheath, to examine the tract walls upon exiting to monitor for additional bleeding.
   NOTE: Some operators have advocated for infusing thrombin into the cavity at this point, either by adding thrombin directly to the irrigation fluid or by injecting gelatin mixed with thrombin through the endoscope. This is a reasonable option, but injecting gelatin mixed with thrombin will make ultrasound imaging impossible.
2. Use burr hole ultrasound to assess for residual hematoma or active bleeding.
   NOTE: Ultrasound is useful for settling doubt about any questionable regions as well as detecting any large areas of residual hematoma that may have been missed under direct visualization.

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Artemis device 2.8mm	Penumbra Inc.	AP28	Cannula outer diameter: 2.8mm. Cannula Length: 27cm. Aspiration tubing length: 9.5ft; The food and drug administration (FDA) approved the Apollo system in 2014 for use in intraventricular hemorrhage (IVH) evacuation but its indication now includes ICH and the Artemis system was approved for the same IVH and ICH evacuation in 2017.
Artemis device 2.1mm	Penumbra Inc.	AP21	Cannula outer diameter: 2.1mm. Cannula length: 26cm. Aspiration tubing length: 9.5ft
Artemis device 1.5mm	Penumbra Inc.	AP15	Cannula outer diameter: 1.5mm. Cannula length: 27cm. Aspiration tubing length: 9.5ft
MAX Canister	Penumbra Inc.	APCAN2
Pump MAX 110V	Penumbra Inc.	PMX110
19-French sheath	Aesculap USA	FH604SU	Outer diameter: 6.33mm
Storz Lotta 3-port endoscope	Karl Stortz	28164 LA / 28164 LS	Outer diameter: 6.1mm. Two ports for irrigation/suction (1.6mm). One working channel (2.9mm)
Medtronic AxiEM	Medtronic	UC201403939	An advantage of the Medtronic AxiEM system is it does not require pinning or line-of-site navigation.
High-speed drill with 5-mm cutting burr	Medtronic	9BA60
Bone wax	Ethicon	W31
Hemostatic gel foam with thrombin	J&J Healthcare	2994
Bipolar cautery	State of the Art	401102
Aloka burr hole ultrasound transducer	Aloka	UST-52114P
11-blade	Bard Parker	372611
Penfield 1 instrument	Sklar Corp	47-2255
AxiEM stylet	Medtronic	9735428