Capillary malformation

The true incidence of capillary malformations or telangiectasias of the brain is difficult to discern because the vast majority are obviously clinically asymptomatic. Estimates from autopsy series suggest they are not uncommon, representing approximately 16%-20% of all CNS vascular malformations (Chaloupka and Huddle 1998). Capillary telangiectasias, although known to occur throughout the brain and spine, are most frequently found within the striate pons and are the most frequent incidental vascular malformation of the pons at autopsy (Russell and Rubinstein 1959 McCormick et al. 1968). Other locations are the basal ganglia, where they usually cause confusion because of their enhancement and the lack of mass effect (Castillo et al. 2001). 

Most capillary telangiectasia are incidental findings on examinations performed for other reasons than brainstem symptoms. In general, the clinical manifestations related to capillary malformations are variable, although typically they are regarded as quiescent lesions occasionally presenting with headache, confusion, weakness, dizziness, visual... 

A dark lesion on GRE images, which is not visible on conventional T2, is usually not a cavernoma but a capillary malformation. Edema, gliosis, or signs of previous hemorrhage are usually absent. Follow-up images have never revealed any change in capillary malformations. 

The exact nature of pontine lesions classified as capillary malformations will remain speculative in the vast majority of patients. Beside vascular malformations, the differential diagnosis of an enhancing pontine lesion might include neoplasm, demyelin-ating disease, infection, infarction, or, rarely, central pontine myelinolysis. The absence of mass effect or significant T2 prolongation, however, argues... 

Venous malformations Lymphatic malformations Capillary malformations Mixed malformations... 

Capillary malformations (CMs), because of their appearance, have traditionally been referred to as port wine stains and incorrectly as capillary hemangiomas. They represent maldevelopment of capillaries and present as well demarcated skin discoloration. CMs initially have a pink or red color and become more purple as children age. CMs frequently occur with other vascular anomalies. In Klippel-Trenaunay syndrome, they occur on the trunk or lower extremity and are associated with limb hypertrophy and widespread venolymphatic malformations. In Sturge-Weber syndrome, the CM is typically in the VI (first division of the trigeminal nerve) distribution on the face and is associated with underlying ophthalmologic and leptomeningeal VMs and CMs. 

Indocyanine green (ICG)-augmented diode laser therapy (ICG+DL) represents a new treatment modality for capillary malformation (GM). However, an increase in the ICG concentration or the use of an intense pulsed light (IPL) device as light source may further optimise treatment outcomes in CM. This proof-of-concept trial included 15 patients (skin type II to III) with CM to evaluate the efficacy and safety of ICG+DL (808nm) at a total dose of 4 mg/ kg b.w. Additionally, five patients with extensive CM received IPL therapy before and after ICG-administration (ICG + IPL) [37 ]. 

Klein A, Baumler W, Buschmann M, Landthaler M,Babilas P. A randomized controUed-trial to optimize indocyanine green-augmented diode laser therapy of capillary malformations. Lasers Surg Med 2013 45(4) 216-24. 

The membrane skeleton acts as an elastic semisolid, allowing brief periods of deformation followed by reestablishment of the original cell shape (reviewed by Bennett and Gilligan, 1993). Erythrocytes in the human bloodstream have to squeeze repeatedly through narrow capillaries of diameters smaller than their own dimensions while resisting rupture. A functional erythrocyte membrane is pivotal to maintaining the functional properties of the erythrocyte. This importance is apparent when examination is made of many hemolytic anemias, where mutation of proteins involved in the structure of the submembranous cytoskeleton, and its attachment to the lipid bilayer, result in a malformed or altered cytoskeletal architecture and a disease phenotype. 

Telangiectasias are collections of dilated capillaries that are usually of no clinical significance (Milandre et al. 1987). They may be associated with hereditary hemorrhagic telangiectasia (the Osler-Weber-Rendu syndrome), but this is more likely to be associated with neurological complications from a pulmonary arteriovenous malformation with right-to-left shunting, such as cerebral hypoxia, brain abscess, paradoxical and septic embolism, or from an associated intracranial arteriovenous malformation or aneurysm (McDonald et al. 1998). 

This benign infantile tumour is of embryonic origin and usually diagnosed within the first months of life, whereby girls are twice as often affected as boys. In most cases, capillary haemangiomas of the skin and mucosa as well as of other organs are also in evidence. Cardiac and vascular malformations are likewise often found. 

The red cell membrane must be highly deformable to allow it to travel throughout the capillary system in the body. This is because of a complex cytoskeletal structure that consists of the major proteins spectrin, ankyrin, and band 3 protein Mutations in these proteins lead to improper formation of the membrane cytoskeleton, ultimately resulting in malformed red cells, spherocytes, in the circulation. Spherocytes have a shortened life span, leading to loss of blood cells. 

X.X. Lin, W. Wang, S.F. Wu, C. Yang, T.S. Chang (1997). Treatment of capillary vascular malformation (port-wine stains) with photochemotherapy. Blast. Reconstr. Surg., 99, 1826-1830. 

Clatterbuck RE, Elmaci 1, Rigamonti D (2001) The juxtaposition of a capillary teleangiectasia, cavernous malformation, and developmental venous anomaly in the brainstem of a single patient case report. Neurosurgery 49 1246-1250... 

Vascular malformations of the brain are usually divided into arteriovenous malformations, capillary telangiectasias, venous malformations, and cavernous malformations. However, for a long time, the term angiographically occult vascular malformation or cryptic (Cohen et al. 1982 Dillon 1997 Wilson 1992) has been used to describe those vascular malformations that could not be visualized angiographically, but obviously were able to cause intracerebral hemorrhage. 

Capillary telangiectasias are a distinct category of cerebral vascular malformations, consisting of localized collections of multiple thin-walled vascular channels interposed between normal brain parenchyma. They were first described in 1959 (Russell and Rubinstein 1989) and are characterized by small capillaries with a maximum di-... 

Hereditary hemorrhagic telangiectasia (Rendu-Osler disease) is not associated with cerebral capillary telangiectasia, but with other forms of cerebral vascular malformations (Maher et al. 2001), mainly true pial arteriovenous malformations, dural arteriovenous malformations, and, rarely, cavernomas. 

Capillary telangiectasias are vascular malformations of unknown origin and unknown clinical significance (Rigamonti et al. 1991 Awad et al. 1993). In vivo diagnosis is only possible with MRI because these lesions are so small that they are undetectable by either conventional angiography or CT (Barr et al. 1996). Furthermore, slow blood flow may also contribute to the lack of angiographic opacification. 

Curiously, about two thirds of capillary telangiectasias show an enlarged vessel believed to represent a draining vein. This observation has led some authors to consider the concept of transitional malformations (Rigamonti et al. 1991). 

Auffray-Calvier E, Desal HA, Freund P, Laplaud D, Mathon G, de Kersaint-Gilly A (1999) Capillary teleangiectasias angiographically occult vascular malformations - MRI symptomatology apropos of 7 cases. J Neuroradiol 26 257-261... 

Awad lA, Robinson JR, Mohanty S, Estes ML (1993) Mixed vascular malformations of the brain clinical and pathogenetic considerations. Neurosurgery 33 179-188 Barr RM, Dillon WP, Wilson CB (1996) Slow-flow vascular malformations of the pons capillary telangiectasias AJNR Am J Neuroradiol 17 71-78 Baumann CR, Schuknecht B, Lo Russo G, Cossu M, Citterio A, Andermann F, Siegel AM (2006) Seizure outcome after resection of cavernous malformations is better when surrounding hemosiderin-stained brain also is removed. Epilepsia 47(3) 563-566... 

Rigamonti D, Johnson PC, Spetzler RF, Hadley MN, Drayer BP (1991) Cavernous malformations and capillary telan-giectasie a spectrum within a single pathological entity. Neurosurgery 28 60-64... 

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