This paper details the surgical protocol for minimally invasive endoscopic intracerebral hemorrhage evacuation using the SCUBA technique.
Intracerebral hemorrhage (ICH) is a subtype of stroke with high mortality and poor functional outcomes, largely because there are no evidence-based treatment options for this devastating disease process. In the past decade, a number of minimally invasive surgeries have emerged to address this issue, one of which is endoscopic evacuation. Stereotactic ICH Underwater Blood Aspiration (SCUBA) is a novel endoscopic evacuation technique performed in a fluid-filled cavity using an aspiration system to provide an additional degree of freedom during the procedure. The SCUBA procedure utilizes a suction device, endoscope, and sheath and is divided into two phases. The first phase involves maximal aspiration and minimal irrigation to decrease clot burden. The second phase involves increasing irrigation for visibility, decreasing aspiration strength for targeted aspiration without disturbing the cavity wall, and cauterizing any bleeding vessels. Using the endoscope and aspiration wand, this technique aims to maximize hematoma evacuation while minimizing collateral damage to the surrounding brain. Advantages of the SCUBA technique include the use of a low-profile endoscopic sheath minimizing brain disruption and improved visualization with a fluid-filled cavity rather than an air-filled one.
Intracerebral hemorrhage is a bleed that occurs in the brain parenchyma and is the most devastating subtype of stroke in terms of mortality and disability. The worldwide incidence of ICH is approximately 24.6 per 100,000 individuals, with 40,000 to 67,000 cases occurring every year in the US1,2. Intracerebral hemorrhage is a medical emergency requiring fast diagnosis and management. Historically, outcomes have been bleak, with mortality rates of 40% at 1 month, 51-54% at 1 year, and 71% at 5 years3,4,5,6. A key reason for such a poor prognosis is that there are no evidence-based treatments for this disease process. Previous clinical trials (STICH I and II) did not demonstrate improved outcomes for surgery compared to conservative medical management7,8. A proposed hypothesis for the failure of craniotomies is that any benefit gained from evacuating the clot is outweighed by the extensive brain trauma inflicted by the invasive nature of the procedure. As a result, in the past decade, a number of minimally invasive techniques have been developed to attempt to solve this problem, each with advantages and disadvantages. The techniques can be grouped into two categories: stereotactic aspiration with thrombolysis and active evacuation. The former involves aspirating the clot through a burr hole, administering a thrombolytic agent, and draining the residual clot through a catheter over the period of several days. This technique is currently being tested in the MISTIE clinical trial and is used by clinicians in China with the YL-1 craniopuncture needle9,10. Active evacuation, on the other hand, involves aspirating the entire clot in a single procedure without the need for a draining catheter.
A number of clinical trials are also underway for this technique, including ENRICH, which utilizes the NICO BrainPath system for endoport-assisted trans-sulcal evacuation; the INVEST trial11, which is a single arm feasibility study using the Penumbra Apollo or Artemis Systems for endoscopic evacuation; and the MIND trial, which is a multicenter randomized clinical trial evaluating endoscopic evacuation using the Artemis device. Endoscopic evacuation is a promising technique because it has the lowest profile working channel to minimize brain trauma12. This paper outlines a specific endoscopic technique described as Stereotactic ICH Underwater Blood Aspiration (SCUBA)13. The first phase focuses on debulking the hematoma using maximal aspiration while working within the end of the sheath. The second phase utilizes a high irrigation rate to aspirate residual clots and cauterize any bleeding vessels in a highly targeted manner.
There are three devices used in the SCUBA procedure: a sheath (6.33 mm), endoscope, and aspiration system. The aspiration system consists of a surgical wand (2.6 mm) designed to fit inside the working channel of an endoscope, which is inserted into the sheath. The wand is capable of aspiration and, with the press of a button on the handle, morcellation. The morcellation component of the device is a spinning bident at the tip of the suction tube that spins upon activation. Suction is activated by covering the hole at the thumb on the handle, and the bident is activated by pressing firmly on the button. Suction activation in this regard is similar to common neurosurgical suction instruments.
Prior to performing this protocol, the required institutional approval and patient consent were obtained. All procedures were approved by Mount Sinai Hospital.
1. Inclusion Criteria
2. Exclusion Criteria
3. Positioning and Planning
4. Opening
5. Phase 1 Evacuation
6. Phase 2 Evacuation
7. Assessment and Closure
The SCUBA evacuation technique has been described in 47 patients undergoing endoscopic ICH evacuation between December 2015 and September 2017. The mean pre-operative ICH volume was reported as 42.6 cm3 (standard deviation = 29.7 cm3; mean post-operative ICH volume = 4.2 cm3, SD 6.6 cm3), resulting in a mean evacuation rate of 88.2% (SD 20.8%) (Table 1). An example of pre-operative and post-operative CT scans is shown in Figure 1. In 23 (48.9%) cases, active bleeding vessels were detected, and in 12 (52.2%) of these cases, bleeding emanated from more than one vessel (Table 2). Bleeding was addressed using irrigation alone in 5 cases (10.6%) and electrocautery in 18 cases (38.3%) (Table 2).Post-operative bleeding was isolated to only a single case (2.1%) in which the routine head CT performed on post-operative day 1 demonstrated that the evacuation cavity had refilled with hemorrhage that appeared to originate from a superficial galeal vessel bleeding into the access tract and cavity (Table 2). This patient's examination did not worsen, and he did not require additional surgery.
Figure 1: CT scans. (A) Pre-operative CT head image demonstrates a large right basal ganglia hemorrhage. (B) CT head image performed on post-operative day 1 demonstrates near-complete evacuation of the hematoma. Please click here to view a larger version of this figure.
Variable | Mean | Standard Deviation |
Preoperative Volume | 42.6 | 29.7 |
Postoperative Volume | 4.2 | 6.6 |
Evacuation Percentage | 88.2% | 20.8% |
Table 1: Evacuation details. ICH volumes and evacuation rates for the SCUBA procedure.
Variable | Number | Percent |
Total Patients | 47 | – |
Active Bleeding Identified | 23 | 48.9% |
Single Vessels | 11 | 23.4% |
Multiple Vessels | 12 | 25.5% |
Irrigation | 5 | 10.6% |
Electrocautery | 18 | 38.3% |
Postoperative Bleeding | 1 | 2.1% |
Table 2: Operative details. Operative details (specifically bleeding vessels) encountered during the SCUBA procedure.
There are several operative best practices to learn and implement during endoscopic ICH evacuation. First and foremost, it is critical to minimize disruption to brain tissue whenever possible. Accomplishing this starts with optimizing the surgical trajectory so that the sheath traverses the shortest possible course while avoiding eloquent structures. For supratentorial ICH, eloquent structures include the supplementary motor area, primary motor and sensory cortices, left superior temporal and angular gyri, and primary visual cortex. In addition, the trajectory should align with the longitudinal axis of the hematoma. The benefits of this strategy include maximizing visualization of the cavity, minimizing torque force on the brain adjacent to the access tract, increasing the likelihood of being able to view the extremes of the cavity, and creating the shortest possible trajectory to the clot, thus minimizing brain trauma.
In addition to minimizing brain tissue disruption, it is also important to minimize distortion of the hematoma cavity. Aspiration in an enclosed cavity can distort elastic brain matter as much as compressive forces with equal damage. To avoid this, suction strength should be at the minimal possible level necessary for effective blood clot aspiration. This is especially important if the tip of the wand is advanced beyond the tip of the sheath. The only time the suction strength should be on high is during Phase 1, when the tip is in direct contact with the clot. The suction strength should decrease as the procedure progresses.
Unfavorable outcomes have been reported when irrigation during an endoscopic intraventricular hematoma evacuation leads to increased intracranial pressure16. The SCUBA procedure avoids this by evacuating the hematoma in Phase 1, which decreases pressure within the cavity, and subsequently irrigating in Phase 2. In Phase 2, the endoscope has a second access port that allows for irrigation outflow, thus avoiding over-distension of the hematoma cavity and elevated intracavitary pressure. In addition, the sheath and tract do not form a watertight seal and irrigation fluid is lost around the sheath.
Achieving and maintaining hemostasis during Phase 2 is a crucial requirement for a successful SCUBA evacuation. It is important to meticulously monitor every wall of the cavity for bleeding vessels and address them accordingly with continuous irrigation or bipolar cautery. Achieving perfect hemostasis ensures that there is minimal risk of postoperative re-bleeding.
Since clear, direct visualization of the residual hematoma within the cavity may not always be possible during the procedure, it is a best practice to check the evacuation with intraoperative imaging after Phase 2. There have been several cases in which direct endoscopic examination suggested that the cavity was clear but residual hematoma was detected on either intraoperative ultrasound or DYNA CT, leading to another pass with the sheath into the cavity and additional hematoma evacuation.
At this early stage in the development of this procedure, there is strong enough evidence to suggest what the lower limit of evacuation percentage of residual clot volume should be. Though there are currently no studies evaluating outcomes for endoscopic procedure evacuation percentages, animal models and the MISTIE trial suggest that increased evacuation is preferred9. In ICH-induced mice, molecules in the blood such as iron had a toxic effect on the surrounding brain tissue, while iron chelators reduced the damage17. The MISTIE II trial found that perihematomal edema volume was smallest when evacuation percentage exceeded 65%, larger when evacuation percentage ranged from 20-65%, and largest when evacuation percentage was less than 20%18. This data also suggest that outcome may improve with higher evacuation percentage, but the study was not powered to assess this feature. The MISTIE phase III, ENRICH, INVEST, and/or MIND trials may shed light on this question.
One area that remains to be resolved is the timeframe of the procedure. Many protocols advocate evacuation within 72 hours and after a 6-hour stability scan to ensure that the hematoma is stable. Many physicians choose this course of action, as a small study from 2004 reported complications, re-bleeding, and poor outcomes in a small series of patients who underwent craniotomy for ultra-early surgery19. More recent studies on minimally invasive endoscopic evacuation have reported good outcomes with ultra-early evacuation20,21. Manuscripts reporting endoscopic evacuation suggest that bleeding is identifiable and controllable in ultra-early evacuations. The ENRICH study protocol requires evacuation within 24 hours of ictus and does not mandate a stability scan. Ultra-early surgery may be an option in the future, but additional studies are necessary to assess the risks and benefits of ultra-early evacuation.
The SCUBA procedure is a minimally invasive intracerebral hemorrhage evacuation technique that involves an endoscope using an aspiration system. Preliminary evidence suggests that the SCUBA technique can be performed safely and reliably results in a high evacuation percentage. Further studies are necessary to assess the impact of this procedure on functional outcomes.
The authors have nothing to disclose.
This research was supported in part by a grant from Arminio and Lucyna Fraga and a grant from Mr. and Mrs. Durkovic.
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 | |
Titanium plate | Depuy Synthes | 04503023/04503024 | |
Titanium screws | Depuy Synthes | 0450310301/0450310401 | |
DYNA CT on the Artis Q | Siemens Healthineers | A91AX-01343-33C1-7600 | |
3-0 Vicryl sutures | Ethicon | J416 | |
4-0 monocryl subcuticular stitches | Ethicon | Y426 | |
Steri-Strips | 3M | R1547 |