Patients were included if they had spontaneous supratentorial ICH with irregular morphology, defined as: (1) multi-regional involvement (≥2 distinct brain areas, e.g., basal ganglia and thalamus), (2) intraventricular extension confirmed on axial CT, or (3) a width-to-length ratio < 50% on axial CT, calculated using 3D Slicer® software (v5.0.3). Hematoma volume, measured via 3D Slicer®’s segmentation module, was required to exceed 20 mL.

Secondary ICH causes (e.g., vascular malformations, aneurysms), coagulopathy (INR > 1.5, platelets < 100 × 10³/mL), or GCS < 5.

Patients were classified into four groups according to the main location of the hematoma on CT scans: Group A (basal ganglia hemorrhage), Group B (subcortical hemorrhage), Group C (thalamic hemorrhage), and Group D [intraventricular hemorrhage (IVH)] (Table 1).

The intracerebral hematoma volumes were analyzed with 3D Slicer software.¹ All patients underwent a CT scan before the operation, a post-operation CT scan within 24 h after the surgery, and a follow-up CT or MRI scan 3 days to 1 month after the operation. The hematoma evacuation rate was calculated as follows: ([preoperative hematoma volume—postoperative hematoma volume]/preoperative hematoma volume) × 100% (Figures 1A,B). After surgery, the patients were managed in the intensive care unit, the blood pressure was controlled, and the consumption of excessive fluid was not allowed.

The sheath was crafted from biocompatible, transparent plastic sourced from sterile saline bags (polyvinyl chloride, medical-grade). Fabrication began with cutting the saline bag into 6*6-cm-long strips under sterile conditions in a laminar flow hood (Figures 2A,B). These strips were rolled into a small diameter sleeve. This is done by rolling or folding the plastic material tightly to minimize the diameter for insertion. Once the sheath was rolled or folded, it was held by the tweezers (Figure 2C). The tight grip of the tweezers ensures the sheath remains in its compact form during insertion. The sheath was inserted into the rigid endoport with the help of tweezers to create a surgical channel and the rigid endoport was removed (Figure 2D) and the sheath, now free from constraints, expands due to its material properties to form a hollow tubular channel within the hematoma cavity (Supplementary Video S1).

This study was approved by the ethics committee of Renmin Hospital of Wuhan University. All patients or their family provided written informed consent, and this procedure was conducted in accordance with the Declaration of Helsinki. Under general anesthesia, patients were positioned supine for the FATSE combined with “two-in-one” approach. Preoperative 3D Slicer® trajectory mapping guided a 4–5 cm coronal incision (Figure 3A). Rapid stereotactic aspiration (3–5 min) via burr hole achieved immediate ICP reduction (Figure 3B). A small bone flap (~2.5 cm) was created followed by cruciate dural opening and 1.5 cm cortical incision. A Rigid transparent endoport was place into the hematoma cavity to create a surgical channel (Figure 3C), and the endoscope was introduced through a fixed rigid endoport for initial hematoma evacuation (Figure 3D), then replaced with the FATSE (Figure 3E), which allowed dynamic sheath adjustment (8–16 mm diameter) to match hematoma geometry—starting collapsed (3–4 mm) for minimal disruption and gradually expanding during evacuation.

Sheath Fabrication and Insertion: The FATSE sheath is fabricated from sterile, medical-grade polyvinyl chloride (PVC) sourced from saline bags. Strips are cut into 6 cm x 6 cm segments, rolled tightly into a compact sleeve (3–4 mm diameter) using tweezers, and inserted into the hematoma cavity via a rigid endoport. Upon removal of the endoport, the sheath expands naturally to form a tubular channel (8–16 mm diameter), adjustable intraoperatively by gentle manipulation to match the hematoma’s geometry.

For multi-compartmental hematomas, we recommend a ‘sheath-in-sheath’ technique, where a smaller secondary sheath (4–6 mm) is inserted through the primary sheath to access difficult-to-reach areas, such as intraventricular extensions or deep parenchymal clots. For cases with intraventricular involvement, the sheath can be angled toward the ventricles while maintaining a stable corridor to minimize parenchymal injury. Surgeons should adjust the sheath diameter gradually during evacuation to optimize visualization and avoid excessive retraction.

Hemostasis is achieved under direct endoscopic visualization using low-power bipolar coagulation (10-15 W) (Figures 3F,G), with favorable post operative intracranial pressure reduction (Figure 3H). Care should be taken to avoid over-coagulation, which may damage surrounding tissue. Post-evacuation, a soft drainage catheter is placed to prevent reaccumulation, followed by layered closure with bone flap replacement (Figure 3I) to minimize cosmetic defects and support recovery. The mean procedure duration was 1 h 9 min 42 s (Figure 3J).

This protocol combined rapid ICP control with complete clot removal while minimizing parenchymal injury, leveraging the FATSE system’s adaptability for irregular hematoma morphologies.

Standard non-surgical management of ICH typically involves medical stabilization, aggressive blood pressure control, and monitoring for complications such as cerebral edema or hydrocephalus. However, for patients with large or irregular hematomas, non-surgical approaches are associated with mortality rates ranging from 30 to 50% and poorer functional outcomes compared to surgical interventions in select cases (2, 19). In our study, the FATSE approach achieved a 0% mortality rate and a mean GCS improvement of 5.2 points, suggesting potential advantages over non-surgical management, particularly for complex hematomas. These outcomes underscore the need to consider minimally invasive surgical options in cases where conservative treatment may be insufficient.

While the zero mortality rate in our cohort of 54 patients is encouraging, it should be interpreted within the context of a retrospective, single-center study focused on the technical aspects and preliminary outcomes of the FATSE approach. This finding is promising but preliminary, and we acknowledge the absence of statistical analysis as a limitation due to the descriptive nature of this initial report. A case–control or prospective study is necessary to rigorously evaluate the effectiveness of this method compared to existing treatments and to provide statistical power to confirm these outcomes. Additionally, the small sample size for Group D (n = 3) and the lack of long-term functional outcome data are limitations that warrant further investigation.

The clinical implications of these findings are substantial. First, the “two-in-one” approach’s rapid ICP reduction phase (3–5 min) addresses the critical time sensitivity in ICH management (20), while the subsequent endoscopic phase allows meticulous hemostasis—a combination that explains our lower rebleeding rate compared to conventional neuroendoscopy (1.9% vs. 2.4%) (8). Second, the sheath’s dynamic adjustability enables tailored treatment for each hematoma’s unique morphology, as evidenced by Group B’s 95.2% evacuation rate in lobar hemorrhages versus Group C’s 94.8% in thalamic cases. This adaptability is further demonstrated in Patient #9’s remarkable outcome (98.3% evacuation of a 41.6 mL basal ganglia-ventricular hemorrhage), showcasing the system’s potential when optimally applied.

Several important limitations warrant consideration. The retrospective design and single-center experience may affect generalizability. The small Group D sample (n = 3) particularly limits definitive conclusions about pure intraventricular hemorrhages, though our 94.9% evacuation rate in these cases remains promising. Additionally, the 1-month follow-up precludes assessment of long-term functional outcomes, an important metric for surgical ICH interventions.

Future research directions should prioritize three key areas: (1) multicenter randomized trials comparing FATSE directly against SCUBA and Apollo/Artemis systems with 6-month functional outcomes, (2) health economic analyses to quantify the system’s cost-saving potential across different healthcare settings, and (3) technological refinements such as augmented reality integration for trajectory planning and pressure-sensitive sheath modifications. The system’s adaptability also suggests potential applications beyond ICH, including tumor biopsies and cyst fenestrations, which merit exploration.