Delayed acute subdural hematoma treated with endoscopic procedure: A case report.

Background: Delayed acute subdural hematoma (DASDH) is defined as late onset ASDH with the absence of any abnormal radiological and clinical findings at initial examination. Moreover, this entity is very rare in traumatic brain injury and its mechanism is still unclear. Recently, endoscopic surgery for ASDH has also been performed. In this case, we describe some considerations of the mechanism of DASDH and review previous literature and usefulness of endoscopic surgical procedure for ASDH. Case Description: A 73-year-old man fell at night, and visited a former medical institution by himself. No abnormal neurological finding was detected. Head computed tomography (CT) detected no abnormal finding. He was diagnosed minor head injury and was hospitalized at midnight and discharged after brain magnetic resonance image (MRI) next day. Brain MRI also detected no abnormal findings. Three days later, he visited our hospital himself, because of the severe headache. Neurologically, he had a mild consciousness disturbance and head CT revealed left ASDH. We performed endoscopic evacuation of hematoma under local anesthesia. Then, the clot was evacuated under the endoscopic procedure through dilated burr hole and pulsatile bleeding from the cortical artery was observed, which was considered to be the source of the ASDH. The patient's consciousness disturbance was improved immediately after surgery and he discharged without neurological deficit.
Conclusion: We revealed the source of bleeding of DASDH under endoscopic procedure and described hypothesis and speculation of its cause in our case. DASDH is rare entity, so we need further experiences and more considerations. Copyright:

INTRODUCTION

Acute subdural hematoma (ASDH) is well known as a severe prognostic factor of head trauma that requires an emergency surgical treatment.[6,19]

We often experienced cases that have increased hematoma during the course and require additional treatment. Moreover, the standard treatment for ASDH is large craniotomy and decompressive craniectomy to prevent secondary brain damage.

Delayed ASDH (DASDH) is very rare concept that defined as late onset ASDH with the absence of any abnormal radiological and clinical findings at initial examination.[4,5] Moreover, the mechanism of DASDH is still unclear.

In this report, we detected a cause of DASDH, during endoscopic surgical procedure and describe some considerations of the mechanism of DASDH, surgical procedure, and review previous literature.

CASE REPORT

A 73-year-old man fell while walking to get to the bathroom late at night and was injured his head, and visited a former medical institution by himself.

His consciousness was clear (Glasgow Coma Scale: GCS E4V5M6) and there were no abnormal neurological findings including loss of consciousness or amnesia. Head computed tomography (CT) was performed and detected no abnormal finding [Figure 1]. He was diagnosed minor head injury and was hospitalized at midnight and discharged after brain magnetic resonance image (MRI) next day. Brain MRI also detected no abnormal findings as the previous head CT [Figure 2].

Figure 1:

Initial head computed tomography revealed no hemorrhagic findings.

Figure 2:

Brain magnetic resonance imaging (FLAIR) on day 2 after head injury, it revealed no hemorrhagic lesions including contusion.

Three days later, he visited our hospital himself, because of the severe headache. Neurologically, he had a mild consciousness disturbance (GCS E4V4M6) and head CT revealed left ASDH with mass effect [Figure 3]. As ASDH existed without cerebral contusion and acute brain swelling, we performed endoscopic evacuation of hematoma under local anesthesia with dexmedetomidine. After the skin was incised, we used a perforator attachment (Integra Life Sciences, disposable perforator diameter: 14 mm, Plainsboro, New Jersey, USA) with a cordless handle to make a burr hole. After perforation, the tip was exchanged from perforator to dilator attachment which we developed (S & B Corporation, Chiba, Japan), and the burr hole was extended to 25 × 30 mm. A rigid scope with a tip angle of 0 or 30° (KARL-STORZ, Tuttlingen, Germany) clearly showed a residual dark red clot. The clot was evacuated using a suction tube and was irrigated with artificial cerebrospinal fluid (Otsuka Pharmaceutical, Tokushima, Japan). Then, the clot was evacuated under the endoscopic procedure through dilated burr hole and pulsatile bleeding from the cortical artery was observed, which was considered to be the source of the ASDH [Video 1]. No other obvious arterial or venous bleeding was observed. Hemostasis was performed using suction-monopolar coagulator (Covidien, Massachusetts, USA), [Video 1]. Postoperative CT and MRI revealed no re-bleeding and indicated the bleeding point [Figure 4]. The patient’s consciousness disturbance was improved immediately after surgery. He stayed 10 days in our hospital and was discharged without neurological deficit.

Figure 3:

Head computed tomography on day 3 after head injury; it was appeared that left acute subdural hematoma with mass effect.

Figure 4:

Postoperative images. Upper: Brain magnetic resonance imaging (FLAIR) showed hemostatic scar by monopolar coagulator (white arrow). Lower: Head computed tomography: Hematoma has been evacuated.

DISCUSSION

There is an approximately 1% risk of life-threatening, intracranial hemorrhagic events that needs immediate neurosurgical operation both in adults and children of mild traumatic brain injury (mTBI).[18] Hence, accurate diagnosis and evaluation of these patients are important to reduce mortality and morbidity. DASDH is rare clinical entity, which is defined as late onset ASDH with the absence of any abnormal radiological and clinical findings at initial examination.[1,2,7,8,13,15-17]

Patients have risk factors, such as coagulation disorder, taking anticoagulants or antiplatelets, alcoholism, deranged liver function, and chronic illnesses, such as diabetes mellitus, hypertension, and underlying cardiac disease. Especially elderly patients, increasing oral antiplatelet or anticoagulation have been shown to be associated with higher risk of intracranial bleeding after head injury.

Especially elderly patients, increasing oral antiplatelet or anticoagulation have been shown to be associated with higher risk of intracranial bleeding after head injury.

In our review, there are 13 cases (including our case) of DASDH after posttraumatic injury [Table 1].[1,2,7,8,13,15-17] Although, the age ranged from 18 to 86 year old (median: 65 year old), nine patients (69.2%) were over 60 years old.

Table 1:

Characteristics of patients with delayed acute subdural hematoma.

Moreover, these nine patients were administered antiplatelet and/or anticoagulant therapy [Table 1]. It is suggested that age, anticoagulation, and antiplatelet therapy are thought to promote late onset bleeding, such as DASDH.

In all cases were diagnosed mTBI which GCS 14–15 at the initial evaluation. And their neurological symptoms were deteriorated between 3 and 72 h in our review. When the symptoms worsen, the GCS score is 8 or less, and the prognosis is very poor [Table 1].

The mechanism of DASDH is still unclear. As described by Zervas et al., the cerebral blood vessels are devoid of vasa vasorum.[21] The cerebral vessels contain a rete vasorum in the adventitia that is permeable to large proteins and is in continuity with the subarachnoid space. This substructure may be analogous to the systemic vasa vasorum and may contribute to the nutrition of the cerebral blood vessels. It can be suggested here that injury to this rete vasorum may cause hypoxic injury to the vessel wall, leading to degeneration, and disruption of the vessel wall. The other hypothesis proposed was spontaneous vascular rupture, resulting from progressive vascular degeneration, the local metabolites causing vascular wall injury, vasoparalysis resulting from local hypoxia, and increased intracranial pressure causing venous congestion produced by Valsalva effect.

In our case, it was presumed that slight damage to the vessel wall occurred first, and then delayed disruption of the vessel occurred due to failure of rete vasorum. We speculated that the antiplatelet might have contributed to delayed bleeding. To confirm this phenomenon, we need to accumulate more cases and further evaluation. Arterial or venous bleeding as a source of ASDH is often seen in craniotomy. However, this is the first report to describe the bleeding point of DASDH and get hemostasis under endoscopic procedure.

Although, the usefulness of endoscopic surgery as a minimally invasive surgery for subdural hematoma in elderly and also young patients have been reported recently,[3,10,12,14,20] there is no report mention that the intraoperative findings of endoscopic surgery applied for DASDH.

The indication and contraindication of endoscopic surgery for SDH have been reported.[18,20] Our case was performed endoscopic surgery followed the indication of the elderly patient described Yokosuka et al.,[20] and Karakhan et al.[9]

The development of useful equipment is important. When making a burr hole as an endoscopic surgical corridor for intracranial hemorrhagic lesions, such as a subdural hematoma, it is necessary to make one with enough size. We developed a novel instrument in the form of a dilator attachment with a cordless handle, making it simple, and safe to extend a burr hole after perforation.[11]

Yokosuka created an irrigation suction cannula with a malleable nozzle to improve procedures in the subdural space.[20] We also used malleable suction to retract the brain surface using a curved section of a suction cannula. This technique is very effective to evacuate the clot and manage hemostasis with insertion of some surgical instruments, even if mild brain swelling has occurred.[12]

Fortunately, our case had no remarkable brain swelling or massive bleeding during surgery; we were able to accomplish the endoscopic procedure with no trouble.

There are no reports that have been made regarding the source of bleeding of DASDH, and it is difficult to explain the mechanism clearly in this case, but this is the first report in which this case was clearly confirmed the source of DASDH during surgery with especially endoscopic procedure.

CONCLUSION

We report a case of DASDH and hypothesis of its pathogenesis based on findings of endoscopic surgical procedure. DASDH is rare entity, so we need further experiences and more considerations.