Three-dimensional computed tomography reconstructive diagnosis of snakebite-induced cerebral infarction

1 Introduction

Deinagkistrodon acutus is a highly venomous snake, which is widely distributed over southern and southwestern China. Deinagkistrodon bite is commonly encountered in emergency departments and seriously endangers patients‘ lives. In this paper, we report on a male patient who incurred a large cerebral infarction after being bitten by a deinagkistrodon acutus and explore the mechanism of thrombosis after Deinagkistrodon bite injury, to investigate effect of the head CT combined with cerebral angiography in cerebral infarction.

2 A Case Report

The 34-year-old male patient was admitted to our hospital due to complaint of upper extremity swelling and pain for 8 hours after the snakebite. He was bitten in the field, felt pain after the injury and was sent to our emergency department when severe swelling ensued. The patient had no abnormal past family history. On admission, he was not able to identify the type of snake but a family member confirmed a recent Deinagkistrodon snakebite. Admission examination showed a pulse rate of 140/minute, with blood pressure at 93/50 mmHg. The patient was conscious, his lungs were clear and heartbeat was regular. Multiple tension blisters were observed in the right upper extremity, especially on the forearm. The shoulder was swollen with high tension while feeling in the distal hands was lost and blood supply was poor (skin appeared purple). Routine laboratory investigations revealed Hb158 g/L (normal arrange: 115–150 g/l), WBC24.89×10⁹/L (normal arrange: 3.5–9.5×10⁹/L), N 0.76. Blood coagulation function showed prothrombin time (PT) greater than 120 seconds (control 16 s), activated partial thromboplastin time (APTT) greater than 120 seconds (control 49 s), and Fibrinogen less than 0.5 (control 1.7 g/L). The patient immediately underwent surgical decompression of fascial compartment and vacuum negative pressure drainage.

During the operation, he was transfused with 400 ml of blood, red blood cell for 2U. After the operation, the patient’s pulse rate was 124 beats per minute, and blood pressure was 108/49 mmHg (maintained by Norepinephrine infusion). Vital signs were monitored, oxygen inhalation was administered, low negative pressure was applied, and a mechanical ventilator assisted respiration. Bleeding at the wound surface increased within 3 hours of the operation and blood pressure could not be maintained in the normal range. Blood coagulation function showed PT was greater than 120 seconds, APTT was greater than 120 seconds, and PLT was 10×109/L. Given the above manifestation, we diagnosed the patient to be undergoing DIC. We immediately infused Deinagkistrodon acutus antivenin and a large quantity of blood to keep the vital signs steady. After administration of the Deinagkistrodon acutus antivenin, patient’s bleeding symptoms gradually improved, and blood pressure and heart rate stabilized.

During this period, the minimal heart rate was 50/min and blood pressure could not be detected. Intensive care therapy lasted 28 hours after surgery, during which anisocoria occurred; the diameter of the right pupil was 5 mm and light reaction disappeared, while the diameter of the left pupil was 2 mm with light reaction still occurring. We immediately conducted a CT head scan, which indicated a large cerebral infarction and hernia in right brain (Fig. 1A). Cerebral angiography showed developmental abnormalities of the right middle cerebral artery and the embryonic cerebral artery of the right brain (Fig. 1B, 1C, Fig. 2 and Video 1). The patient was advised to have emergency surgery for decompressive craniotomy, but the patients’ family members decided to have palliative care based on the patient’s condition. The patient was discharged to return home and died after 41 hours later. During the hospital stay the patient was transfused with a total of 14U of RBC, 4050 ml of blood plasma, and one cryoprecipitate.

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Fig.1

Multiple cerebral infarction and Cerebral vascular malformations abnormality in the cerebral angiography. (A) Cerebral infarction at the labor of the right and left cerebrum; (B) Developmental abnormalities narrowing of the right middle cerebral artery at the angiogram; (C) Embryonic cerebral artery of right brain, P1 was short and small, and posterior communicating artery was enlarged.

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Fig.2

A dynamic video based on 3D reconstruction of CT images and cerebral angiography. The cerebral infraction areas at the labor of the right and left cerebrum were labelled with blue color.

Deinagkistrodon acutus is mainly found in the southeast and west of mainland China and in Taiwan [1, 2]. While also found in Laos and North Vietnam, more than 90% of the species range is found in China [3]. Previous research has reported that snake venom affects the coagulation mechanism. In the case of viper bites clinic bleeding is common and large doses of snake venom cause intravascular coagulation, thrombosis and even large areas cerebral infarction [4]. Mosquera et al. [5] have reported that the incidence of stroke after being bitten by Bothrops spp. was 2.6%, with intracranial hemorrhage being more common than cerebral infarction, and that prognosis is very bad [6]. In our case, pupil response changes were observed at 36 hours after injury, and brain injury was confirmed by a 3D CT head examination. Possible reasons for the cerebral infarction may be as follows: (1) the snake venom induced abnormal coagulation and DIC micro thrombosis; (2) the venom damaged the endothelial cell and vasculitis lesion, and promoted platelet aggregation, coagulation, thrombosis [7]; (3) shock hypotension induced cerebral vascular insufficiency, resulting in blood flow blockage and thrombosis [8]; (4) cerebral vasospasm occurred due to snake venom; (5) abnormal vascular development was pre-existing in this patient.

With the development of imaging techniques such as computed tomography (CT), the 3D reconstructed images provide more detail information about morphological features and anatomic relationship of diseased tissues so as to give patients better therapy. This non-invasive 3D quantification method with registration algorithm can be used in longitudinal study of root resorption and a new approach in diagnosis and predication of various dental diseases, including tumors, inflammatory, trauma and congenital defects [9, 10]. Using 3D reconstructed CT imaging in kidney neoplasms or adrenocortical carcinoma (ACC), such technology were discussed to reveal that the 3D dynamic video can help surgeon to make better preoperative assessment so as to give patients better therapy [11–15]. At present, the CT has used routinely in the diagnosis of brain injury, stroke and intracranial tumors. However, there is no report on CT combined with cerebral angiography 3D for snake bite brain infarction. In this report patients, we developed a technology to generate a video originated from 3D reconstructed CT images. The processed videos demonstrated stereo all-round, and dynamic information. Not only clear infarction in patients with vascular and area, further clear about the abnormal in patients with cerebrovascular malformations.

Conflict of interest

There was no conflict of interest to be declared.