Introduction

Cavernous malformations (CM) of the spinal cord is a type of vascular diseases of the central nervous system (CNS) [1—4]. Intramedullary CMs account 3—5% of all spinal cord diseases, their incidence among cavernous malformations of CNS is 5—8%. CMs are more common in women (2: 1), and clinical manifestations usually occur in patients aged 30—60 years. MRI is the most accurate method for diagnosis of symptomatic and asymptomatic CMs [1—4].

The need for surgical treatment of patients with symptomatic and asymptomatic cavernomas is still under discussion. This is due to contradictory data on the risk of hemorrhage and absence of reliable methods to predict the course of disease [1—4].

It was shown that indocyanine green video angiography in surgery for CM of spinal cord associated with high risk of appearance or aggravation of neurological symptoms facilitates intraoperative localization of malformation before myelotomy. Moreover, this method is valuable to evaluate the presence of residual malformation tissue after resection. These measures improve quality of resection and minimize risk of complications [5, 6].

The first application of intraoperative video-angiography in surgical treatment of a patient with intramedullary C2—C3 CM performed at the Burdenko Neurosurgery Center is reported.

Case report

A 51-year-old patient M. was hospitalized at the Burdenko National Research Center for Neurosurgery for elective surgical treatment with a diagnosis of intramedullary mass lesion with sings of hemorrhage at the level of C2—C3.

At admission, the patient complained of muscle spasm in the right half of the body, weakness in the right limbs and impaired sensitivity in the left half of the body.

In 1997, the patient was hospitalized at the City Clinical Hospital with a diagnosis of acute hemorrhagic spinal stroke followed by right-sided hemiparesis. Etiology of this event was unclear. Symptoms completely regressed within 1 year. In 2013, recurrent hemorrhagic spinal stroke occurred and was followed by Brown-Sequard syndrome. Repeated examination revealed arteriovenous malformation (AVM) of cervical spinal cord. The patient was referred to the National Research Center for Neurosurgery.

MRI (T1WI and T2WI) of the cervical spine and spinal cord confirmed intramedullary mass lesion at the level of C2—C3. The lesion was characterized by cellular heterogeneous structure, reduced signal along the periphery (hemosiderin deposition). MRI data confirmed ventrolateral CM (Fig. 1).

Right-sided Brown-Sequard syndrome below C3—C4 was diagnosed at admission. McCormiсk score — 3, Frankel grade — D.

Resection of mass lesion with intraoperative neurophysiological monitoring and indocyanine green video-angiography was preferred considering two hemorrhagic episodes, high risk of recurrent hemorrhage with subsequent neurological deterioration, localization of spinal cavernoma and the absence of somatic contraindications for surgical treatment.

Surgery

Surgery was performed in patient’s prone position and under general anesthesia. Intraoperative neurophysiological monitoring of evoked motor potentials from the muscles of the upper and lower extremities was applied. C2—C3 laminectomy was performed. Dural membrane dissection on the left dorsolateral surface of spinal cord was followed by visualization of intra-extramedullary CM with a minimal exophytic component and hypertrophic venous vessels.

Indocyanine green video-angiography (Santen, 0.3 mg/kg) was performed using operating microscope (Haag-Streit Surgical) for accurate resection of CM. Contrast agent was diluted in 8 ml of 0.9% NaCl sterile solution. Bolus injection volume was 3 ml. Examination included sequential arterial, capillary, venous and “post-venous” phases with a total duration of about 5 minutes. After that, localization of CM and vascular features were evaluated (Fig. 2).

Median myelotomy was performed cranial and caudal to cavernoma, the vessels were dissected and coagulated. Brain tissue was separated and fixed on the ligatures to the pia mater. Malformation was dissected within the gliosis border between the cavernoma and spinal cord tissue. En-bloc resection was made with preservation of all adjacent vascular plexuses. All material was sent for histological examination (Fig. 3).

Control intraoperative angiography after resection of CM did not reveal any abnormal vessels within surgical area (Fig. 4).

Hemostasis was followed by closure of dura mater by continuous suture. The wound was sutured in layer-by-layer fashion.

Reduced amplitude of evoked motor responses from the leg muscles (by 70—80% on the right and 30—40% on the left) was noted during resection of CM. Amplitude of evoked motor responses from the hand muscles was intact. Clear motor responses from the all limbs were recorded as soon as surgery was finished.

Postoperative period was uneventful. There was no neurological aggravation. The patient was activated on the first day after surgery. Length of hospital-stay was 7 days. Patient was discharged in satisfactory condition. There was right-sided hemiparesis (MRC score 4) and sensitive disorders (reduced deep sensitivity on the right and superficial sensitivity on the left) below C3 segment. McCormiсk score — 2, Frankel grade — E.