Syndromic association of spinal arteriovenous malformations: CLOVES syndrome : Journal of Cerebrovascular Sciences

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Case Report

Syndromic association of spinal arteriovenous malformations

CLOVES syndrome

Mahajan, Mahesh; Singh, Daljit; Sahni, Harkaran Singh; Bhandari, Sumit; Vishwakarma, Dheeraj

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Journal of Cerebrovascular Sciences 10(1):p 49-52, Jan–Jun 2022. | DOI: 10.4103/jcvs.jcvs_21_22
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The study design was a case report of spinal cord arteriovenous malformation (SCAVM) with various associations. The objective of this study was to demonstrate the need to identify atypical clinical associations with spinal arteriovenous malformation and their staged management. A 19-year-old boy was diagnosed with SCAVM after paraplegia and bowel bladder disturbances. However, a complete diagnosis of SCAVM with its syndromic association helps to treat the patient in holistic way. The correct diagnosis of SCAVMs and their type is difficult. Complete diagnosis relies on radiological investigations as well as detailed examination. The early and complete diagnoses of SCAVMs are important because patients are likely to have better functional statuses after treatment if their pre-treatment deficits are relatively mild.


Spinal cord arteriovenous malformations (SCAVMs) are abnormally developed blood vessels can arise from any vascular components which result in clinical signs and symptoms secondary to mass effect and ischemia. Arteriovenous malformations (AVMs) of the spinal cord are relatively rare, being only one-tenth as common as cerebral AVMs and one-tenth as common as primary spinal neoplasms.[1] Pathophysiology involves increase in venous pressure due to shunting of blood (steal phenomenon) causing congestion in medullary veins and reduced intramedullary blood flow resulting in ischemic hypoxic insult to the spinal cord.[2] There are historical evolutions of the classification of spinal AVMs, as these are rare lesions, there is still a lack of clear comprehensive classification system. Many of these patients have associated anomalies which are often overlooked, these associations can directly attribute to the clinical outcome of the patient.


A 19-year-old male national Para-Olympic swimmer presented with sudden onset upper back ache referred to as chest wall, weakness of bilateral lower limb for the past 7–8 months and bowel bladder disturbances in the form of urinary incontinence and constipation for the past 1 month. For these progressive complaints, the patient was taken to the private hospital and was diagnosed to have spinal AVM. The patient was referred to our institute for further management. On clinical examination, vitals were essentially normal. On general physical examination, the patient had multiple lipomatous overgrowth over back, epidermal nevi all over the body, multiple musculoskeletal abnormalities including hypoplastic phalynx of the left hand and left forearm shortening. Moreover, the patient had bruit over the lower cervical spinal level (Virtually diagnostic of Type II/Type III spinal AVM, Oldfield and Doppman classification) [Figure 1]a, [Figure 1]b, [Figure 1c].

Figure 1:
(a) Epidermal nevi over the upper limb, (b) Lipomatous overgrowth over back, (c) Musculoskeletal abnormalities as hypoplastic left upper limb as compared to right with hypoplastic phalynx

On neurological examination – tone was normal in the bilateral upper limb and increased in bilateral lower limb, DTR was exaggerated at triceps, knee and ankle joint with bilateral plantar extensor. The power was normal proximally bilateral upper limb, whereas there was distal weakness in the form of the finger grip 70%–80%. Spastic paraparesis at the hip, knee and ankle joint was 2/5 and 3/5 over the right-sided lower limb. There was sensory level demarcation at the C5 level.

On MRI T1 and T2 signal voids from high-velocity flow with dilated peri-medullary vessels scalloping of the cord from C5 to D1 level gave the impression of spinal AVM [Figure 2].

Figure 2:
T2 signal voids from the high-velocity flow with dilated peri medullary vessels scalloping the cord from C5 to D1 level gave the impression of spinal AVM. AVM: Arteriovenous malformation

The patient underwent diagnostic digital subtraction angiography (DSA) with selective and super selective shoots of bilateral vertebral arteries and other branches of the subclavian artery. Findings noted were feeder from the left vertebral artery (V2) segment, left thyrocervical trunk (cervical branch), right vertebral artery (V2) segment and right thyrocervical artery (cervical and inferior thyroid branches). The patient underwent two sessions of endovascular embolisation using n-butyl cyanoacrylate (NBCA) with duration of 3 days in between. A significant decrease in flow and nidus size was noted on post-embolisation DSA [Figure 3]a, [Figure 3]b, [Figure 3]c, [Figure 3d].

Figure 3:
(a) Feeder from the cervical branch (black Arrow) of the left thyrocervical trunk, (b) Post-NBCA embolisation decreased flow to AVM from the left thyrocervical feeder with cast in situ, (c) Feeder from the cervical branch of the right thyrocervical trunk (red arrow), (d) Post-NBCA embolisation (cast in situ) decreased flow to AVM from the right thyrocervical feeder with cast in situ. AVM: Arteriovenous malformation, NBCA: n-butyl cyanoacrylate

However, on contrary, there was no significant clinical improvement was seen; hence the decision of laminectomy and AVM excision was taken. The patient was given pre-operative steroids to minimise cord swelling, underwent wide laminectomy and decompression after 2 weeks of endovascular embolisation. Intraoperatively, the patient had cervical scoliotic deformity and hypertrophied muscles of the back with abnormal bunch of vessels running right from the subcutaneous plane to the bony lamina level (Features of Type III, Juvenile or Metameric Spinal AVM where there are malformations of all derivatives of same metameric segment). Complexity of anatomy and torrential bleeding hindered the field of dissection and made surgery challenging. Secondary to the heavy bleed patient had fall of Hb to 2.6 g% and HCt 24, had intraoperative cardiac arrhythmias, considering haemodynamic instability procedure was abandoned and the patient was shifted to the post-operative intensive unit. The patient was extubated the next day and gradually weaned off from the inotropic support. The patient was kept on postoperative steroids and low-molecular-weight heparin to minimise thromboembolic events. No significant drain output was there and dressing over the wound was also dry. The patient showed clinical improvement with decrease in tone of lower limbs. Power in the right lower limb improved to 4/5 (From 3/5) and left lower limb 3/5 (from 2/5). This clinical improvement was attributed to laminectomy of C6-C7 vertebrae which led to decompression of the cord.

Considering the heavy bleed intraoperatively which suggested incomplete devascularisation of AVM, a 1-week post-laminectomy check DSA was performed which showed refilling of AVM nidus from left VA (V2) segment, left thyrocervical (cervical segment) and right thyrocervical trunk (cervical segment). The third setting of endovascular embolisation was done using GDC coils. Post-embolisation significant decreased flow was noted in AVM [Figure 4]a, [Figure 4]b, c, [Figure 4d and Figure 5]a, [Figure 5b].

Figure 4:
(a) Feeder from the cervical branch of the right thyrocervical trunk (black arrow), (b) Post-coil embolisation decreased flow to AVM from the right thyrocervical feeder with coils in situ. (c) Feeder from the cervical branch of the left thyrocervical trunk (red arrow), (d) Post-coil embolisation decreased flow to AVM from left the thyrocervical feeder with coils in situ. AVM: Arteriovenous malformation
Figure 5:
(a) Feeder from left VA (V2) segment (black arrow), (b) Post-coil embolisation decreased flow to AVM. AVM: Arteriovenous malformation

With the various abnormalities present, there was a possibility that the patient could be having some syndrome. Hence, the list of differentials of various syndromes was made with features similar to the patients and further analysed. The differentials to rule out were CLOVES syndrome, Beckwith Wiedemann syndrome, Proteus syndrome, Klippel-Trenaunay syndrome, NF-1, Hemihyperplasia multiple lipomatosis, McCune-Albright syndrome and Langer-Geidon syndrome. Among the various syndromes, patient's anomalies fitted closely with CLOVES syndrome.

CLOVES syndrome is an acronym denoting rare condition consisting of Congenital Lipomatous Overgrowth Vascular malformation Epidermal nevi and Skeletal/Scoliosis/Spinal anomalies. CLOVES syndrome is a recently described sporadic overgrowth disorder with features of Truncal fatty overgrowth, vascular malformations, epidermal nevus and skeletal anomalies (including scoliosis and variable acral anomalies).[3] Other spinal comorbidities in CLOVES syndrome include scoliosis, vertebral anomalies, neural tube defects and tethered cord. Genetics – missense mutation of PIK3CA gene.

The aetiology of overgrowth syndromes associated with vascular anomalies, including CLOVES, is largely unknown.

These rare sporadic and asymmetric phenotypes could result from genetic mutations, which in autosomal form, would be lethal but which survive through mosaicism, as proposed by Happle.[4] In a review of the cohort of patients with CLOVES syndrome at Children's Hospital Boston, Alomari described the presence of spinal-paraspinal fast-flow lesions in 5 of 18 patients.[5]Alomari AI Characterization of a distinct syndrome that associates complex truncal overgrowth, vascular and acral anomalies: a descriptive study of 18 cases of CLOVES syndrome. Some of the cardinal features of CLOVES syndrome may appear to overlap other overgrowth disorders, such as Klippel–Trenaunay syndrome, Cobb syndrome, Proteus syndrome and Parkes Weber syndrome [Table 1].

Table 1:
Various syndromes associated with spinal arteriovenous malformations


SCAVMs are relatively rare, comprising about 1/10 of all central nervous system AVMs and 3%–4% of all spinal cord masses.[6] SCAVMs often result in neurological deficits and disabilities initially and >70% of patients will show improvement after adequate treatment and rehabilitation.[7,8] Early diagnoses of SCAVMs are important because patients are likely to have better functional statuses after treatment if their pre-treatment deficits are relatively mild.[9] The present case illustrates the significance of detailed clinical examination which can assist in diagnosing various syndromic associations with SCAVMs. CLOVES syndrome is an acronym denoting rare condition consisting of Congenital Lipomatous Overgrowth Vascular malformation Epidermal nevi, Skeletal/Scoliosis/Spinal anomalies. Genetics–missense mutation of PIK3CA gene results in CLOVES syndrome.

Type III (Juvenile/Metameric) AVM is lesions most difficult to treat, with high flow and large malformations involving paraspinal structures as well. Neurological deficits are secondary to venous congestion, haemorrhage, spinal cord compression or vascular steal. The treatment of such lesions is mainly palliative in goal of stabilising the nidal size and symptoms.[10,11] Staged endovascular partial treatment of these malformations may serve to reduce the size and alleviate congestive symptoms. Half of the patients with partially treated Type III SCAVMs neurologically stabilise or improve, although they may need treatment in the future.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

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Conflicts of interest

There are no conflicts of interest.


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Congenital lipomatous overgrowth vascular malformations epidermal nevi and spinal/skeletal abnormalities (CLOVES); digital subtraction angiography; spinal cord arteriovenous malformations

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