an arterio - venous malformation ( avm ) is an abnormal fistulous connection between the feeding arteries and draining veins , without an intervening capillary bed within the subcutaneous layer .
its management is difficult because of its complex vascular anatomy , high - shunt flow ( in high - flow avm ) , intracranial connection ( when present ) and possible cosmetic complications .
they are relatively rare vascular lesions present as an subcutaneous scalp lump or a large , pulsatile mass with a propensity to skin erosion and massive haemorrhage .
several treatment options that have been described to treat these lesions , including surgical excision , ligation of feeding vessels , transarterial and transvenous embolization , injection of sclerosant into the nidus and electro thrombosis . here , we have described our experiences of surgical management of scalp vm ( svm ) and result along with a short literature review .
eleven patients with scalp avm and svm who underwent surgical excision of lesion in dhaka medical college hospital and few private hospitals in dhaka , bangladesh from 2006 to 2012 were included .
all clinical data , investigations , surgical procedures and postoperative follow - up were recorded and studied prospectively .
all suspected high - flow avm were investigated with the selective internal and external carotid digital subtraction angiogram ( dsa )  computed tomography ( ct ) scan of brain with ct angiogram or magnetic resonance imaging ( mri ) of brain with mr angiogram , and all suspected low - flow vascular malformation ( vm ) was investigated with mri of brain + mr angiogram .
no scale or criteria was used for the assessment of cosmetic appearance other than patient 's own and his / her relatives appreciation of the final appearance ( excellent , good , acceptable or not acceptable ) .
the patient was positioned according to the site of lesion with the head elevated 20 - 30 above the level of the heart .
the scalp flap was made according to the anatomy of the avm and vm , and the direction of the feeding arteries and draining veins . in very high - flow avms , proximal control of external carotid artery
the feeding arteries were preserved at the base of the scalp flap , and the flap incorporated one or more normal non - feeding vessels so as not to jeopardize its vascularity .
the skin incision line was infiltrated adequately with lignocaine with adrenaline ( 1:100000 strength ) only in low - flow svm .
the scalp was incised in short segments with careful haemostasis using haemostatic forceps and bipolar coagulation .
the feeding arteries were identified along their course at the base of the scalp flap , the pericranium and galea were incised , the vessels were traced distally towards the nidus of the scalp malformations , ligated , and/or coagulated and then divided . as the feeding vessels were ligated , the vm was devascularized .
the pericranium and the galea were circumferentially incised , and the vm was excised . where there was unavoidable skin loss with the excised lesion , wound was closed multiple galeal incisions and scalp mobilization and/or rotational flaps .
the patient was positioned according to the site of lesion with the head elevated 20 - 30 above the level of the heart .
the scalp flap was made according to the anatomy of the avm and vm , and the direction of the feeding arteries and draining veins . in very high - flow avms , proximal control of external carotid artery
the feeding arteries were preserved at the base of the scalp flap , and the flap incorporated one or more normal non - feeding vessels so as not to jeopardize its vascularity .
the skin incision line was infiltrated adequately with lignocaine with adrenaline ( 1:100000 strength ) only in low - flow svm .
the scalp was incised in short segments with careful haemostasis using haemostatic forceps and bipolar coagulation .
the feeding arteries were identified along their course at the base of the scalp flap , the pericranium and galea were incised , the vessels were traced distally towards the nidus of the scalp malformations , ligated , and/or coagulated and then divided . as the feeding vessels were ligated , the vm was devascularized .
the pericranium and the galea were circumferentially incised , and the vm was excised . where there was unavoidable skin loss with the excised lesion , wound was closed multiple galeal incisions and scalp mobilization and/or rotational flaps .
among the 11 cases as seen in table 1 [ figures 1 - 11 ] eight were high - flow avm and three were low - flow svm ( two cavernoma and one venous malformation - sinus pericranii ) .
only two patients had history of trauma , and two patients had history of prior surgery for their lesions . in five patients , the avm extended on the both side of midline .
there was no supply to avm from mca , anterior cerebral ( aca ) or vertebro - basilar system .
in one case ( case 5 ) , there was some intracranial venous communication . in case 2 ,
bleeding was not a problem in ten cases where blood transfusion was one unit or less . in case 5
, three unit blood was required due to external carotid artery ( eca ) partial rupture and intracranial venous communication .
complete excision was done satisfactorily in all cases without any recurrence until the last follow - up .
minor infection occurred in one case ( case 5 ) , and wound infection and wound dehiscence occurred in two cases . in case 7 , wound infection and dehiscence
were managed conservatively with antibiotic and regular dressing . in case 10 , the dehiscence was very big , and a second operation was needed to close it with local scalp rotational flap .
excellent cosmetic result was observed in nine cases . in two cases , wound healing was acceptable with scar formation in hairy area .
( b ) post - operative picture of patient ( a and b ) pre - operative picture of lesion and patient .
( c and d ) post - operative picture patient with good cosmetic outcome ( a and b ) cta of head showing frontal venous malformation ( sinus pericranii ) with normal intracranial venous sinuses .
( d ) per - operative picture after complete excision of lesion ( a and b ) cta of extracranial vessel showing left posterior parietal avm with feeder from superficial temporal and occipital artery peroperative picture of temporal cavernoma ( a and b ) ct scan of head showing huge diffuse extracranial soft tissue swelling and multiple vascular marking ( guttering and erosion by avm vessels ) ( a - i ) dsa of eca and internal carotid artery ( ica ) showing bilateral feeding vessels from branches of eca and ica through supratrochlear and supraorbital arteries
. there was aneurysmic and ecstatic dilatation of right eca and its branches ( a - c ) immediate pre - operative picture of avm .
( g and h ) post - operative picture of 9 post - operative day .
( i ) post - operative picture 4 week after operation with good cosmetic outcome ( a and b ) pre - operative picture of patient and lesion .
( d ) per - opeartive picture after complete removal of low - flow vascular malformation ( a ) pre - operative picture of lesion and patient . ( b and c ) immediate pre - operative picture of lesion .
( e and f ) post - operative picture of patient with ultimate outcome of operating site 2.5 months after operation ( a and b ) post - avm excisional wound infection and large wound gap .
( c and d ) pictures of wound 12 day after second operation ( wound closure by rotational flap of scalp ) .
( e and f ) pictures 1 year after operation showing acceptable cosmetic outcome an 8-month - old male child presented with a 9  11 cm swelling in mid - frontal region extending more to the right up to the supra - orbital region . swelling increased in size during cry and prone position of the baby , and it was compressible and non pulsatile .
ct scan of brain showed extra - calvarial soft tissue mass in frontal region , and there was no apparent bony gap infront of anterior fontanel .
ct angiogram showed soft tissue mass was vascular lesion connected with sss through emissary veins and intracranial dural sinuses including sss were normal .
the lesion was excised completely by elevation of a bi - frontal flap through a post - hairline bi - coronal incision .
connecting emissary veins were coagulated and cut to remove the lesion . the lesion was well - defined capsulated without septation and filled with venous blood .
the patient recovered uneventfully ( figures 2 and 3 ) and has remained asymptomatic for last 5 years ( until the last follow - up ) . a 43-years - old male patient presented with right - sided pulsatile , progressively increasing fronto - parieto - temporal swelling measuring about 15  19 cm .
he had a history of surgery 5 years back in another institution . according to the patient ,
he also had recurrent attack of haemorrhage from the ulcerated area but none were of serious nature to cause shock and were controlled by pressure dressings .
ct scan showed large soft tissue swelling [ figure 6 ] and the bony windows showed multiple erosions and prominent vascular marking .
right - sided common carotid artery and eca angiogram showed huge dilatation of branches ( occipital artery , posterior auricular artery , superficial temporal artery and maxillary artery and its branches , including meningeal and middle temporal arteries ) of eca supplying the avm .
left eca angiogram showed enlargement and tortuousity of left occipital , posterior auricular and superficial temporal arteries supplying the avm crossing the midline . both internal carotid artery ( ica )
aca , middle cerebral ( mca ) and vertebro - basilar arterial systems were normal and intracranial venous drainage system seemed to be normal [ figure 7 ] .
right - sided eca was ligated at the beginning of operation through a neck incision ( during ligation , partial rupture of eca occurred , which was immediately controlled ) . then
, avm was excised completely with some part of skin ( ulcerated and infected area ) . at the posterior part of avm
postoperatively , there was minor wound infection that was controlled by regular dressing and antibiotic .
the patient has remained free of recurrence of avm for last 1.5 years ( until the last follow - up ) .
an 8-month - old male child presented with a 9  11 cm swelling in mid - frontal region extending more to the right up to the supra - orbital region . swelling increased in size during cry and prone position of the baby , and it was compressible and non pulsatile .
ct scan of brain showed extra - calvarial soft tissue mass in frontal region , and there was no apparent bony gap infront of anterior fontanel .
ct angiogram showed soft tissue mass was vascular lesion connected with sss through emissary veins and intracranial dural sinuses including sss were normal .
the lesion was excised completely by elevation of a bi - frontal flap through a post - hairline bi - coronal incision .
the patient recovered uneventfully ( figures 2 and 3 ) and has remained asymptomatic for last 5 years ( until the last follow - up ) . a 43-years - old male patient presented with right - sided pulsatile , progressively increasing fronto - parieto - temporal swelling measuring about 15  19 cm . he had headache and tinnitus .
he had a history of surgery 5 years back in another institution . according to the patient ,
he also had recurrent attack of haemorrhage from the ulcerated area but none were of serious nature to cause shock and were controlled by pressure dressings .
ct scan showed large soft tissue swelling [ figure 6 ] and the bony windows showed multiple erosions and prominent vascular marking .
right - sided common carotid artery and eca angiogram showed huge dilatation of branches ( occipital artery , posterior auricular artery , superficial temporal artery and maxillary artery and its branches , including meningeal and middle temporal arteries ) of eca supplying the avm .
left eca angiogram showed enlargement and tortuousity of left occipital , posterior auricular and superficial temporal arteries supplying the avm crossing the midline . both internal carotid artery ( ica )
vertebro - basilar arterial systems were normal and intracranial venous drainage system seemed to be normal [ figure 7 ] .
right - sided eca was ligated at the beginning of operation through a neck incision ( during ligation , partial rupture of eca occurred , which was immediately controlled ) . then
, avm was excised completely with some part of skin ( ulcerated and infected area ) . at the posterior part of avm
postoperatively , there was minor wound infection that was controlled by regular dressing and antibiotic .
the patient has remained free of recurrence of avm for last 1.5 years ( until the last follow - up ) .
an 8-month - old male child presented with a 9  11 cm swelling in mid - frontal region extending more to the right up to the supra - orbital region . swelling increased in size during cry and prone position of the baby , and it was compressible and non pulsatile .
ct scan of brain showed extra - calvarial soft tissue mass in frontal region , and there was no apparent bony gap infront of anterior fontanel .
ct angiogram showed soft tissue mass was vascular lesion connected with sss through emissary veins and intracranial dural sinuses including sss were normal .
the lesion was excised completely by elevation of a bi - frontal flap through a post - hairline bi - coronal incision .
the patient recovered uneventfully ( figures 2 and 3 ) and has remained asymptomatic for last 5 years ( until the last follow - up ) .
a 43-years - old male patient presented with right - sided pulsatile , progressively increasing fronto - parieto - temporal swelling measuring about 15  19 cm .
he had a history of surgery 5 years back in another institution . according to the patient ,
he also had recurrent attack of haemorrhage from the ulcerated area but none were of serious nature to cause shock and were controlled by pressure dressings .
ct scan showed large soft tissue swelling [ figure 6 ] and the bony windows showed multiple erosions and prominent vascular marking .
right - sided common carotid artery and eca angiogram showed huge dilatation of branches ( occipital artery , posterior auricular artery , superficial temporal artery and maxillary artery and its branches , including meningeal and middle temporal arteries ) of eca supplying the avm .
left eca angiogram showed enlargement and tortuousity of left occipital , posterior auricular and superficial temporal arteries supplying the avm crossing the midline . both internal carotid artery ( ica )
aca , middle cerebral ( mca ) and vertebro - basilar arterial systems were normal and intracranial venous drainage system seemed to be normal [ figure 7 ] .
right - sided eca was ligated at the beginning of operation through a neck incision ( during ligation , partial rupture of eca occurred , which was immediately controlled ) . then
, avm was excised completely with some part of skin ( ulcerated and infected area ) . at the posterior part of avm
postoperatively , there was minor wound infection that was controlled by regular dressing and antibiotic .
the patient has remained free of recurrence of avm for last 1.5 years ( until the last follow - up ) .
the scalp avm is an abnormal arteriovenous communication situated within the subcutaneous fatty layer of the scalp . in low - flow vm ( i.e. , cavernoma , cavernous hemangioma , venous malformation and sinus pericranii ) , usually , no arteriovenous shunt is present and they are seen as well - demarcated lesions .
the origin of avm of the scalp is still uncertain , but trauma is an important factor in most of the patients , though some are congenital ( spontaneous ) in origin .
spontaneous avm of the scalp may present at birth , but , in most patients , it is asymptomatic until adulthood .
traumatic avm of the scalp develops months or years after the scalp trauma . about 10 - 20% of scalp avms
various names being used to describe the vms of the scalp include aneurysm cirsoide , aneurysma serpentinum , aneurysm racemosum , plexiform angioma , arteriovenous fistula and avm .
the origin of the main feeding arteries is in the subcutaneous tissue of the scalp .
the origin of these main feeders , most frequently , arises from the external carotid , occipital and supraorbital arteries .
two patients had blunt injury to the head . however , these patients noticed the swelling many years later .
most of the patients had a history of progressive increase in the size of the lesion and had become symptomatic in the third decade of life .
the patients may present with a pulsatile mass , headache , local pain , tinitus , numbness , necrosis , ulcer and/or haemorrhage .
angiography is the gold standard investigation to delineate the lesion and to exclude an intracranial component ; it is of great importance for diagnosis and treatment selection .
selective angiography should be carried out for differential diagnosis of the vascular lesions , such as aneurysms , sinus pericranii , venous malformation and cavernous hemangioma .
scalp high - flow avms are needed to differentiate from low - flow avms as the latter are more susceptible to sclerotherapy .
avms show flow void signs on mri due to the rapid flow in the lesions .
management of scalp avm is difficult because of its high shunt flow , intracranial communication , complex vascular anatomy and cosmetic problems .
when sinus pericranii or venous malformation associated with intracranial sinus occlusion or congenital absence of sinus , then treatment become difficult .
the indication of treatment includes cosmetic relief of the pulsatile or non - pulsatile mass , prevention of haemorrhage and other symptoms such as headache and tinnitus .
the treatment options include surgical excision ligation of feeding vessels , transarterial and transvenous embolization , injection of sclerosant into the nidus and electro thrombosis .
surgical excision is the most common and successful method of dealing with scalp vascular lesion .
surgical treatment is particularly indicated in order to rule out bleeding and for the resolution of cosmetic problems , as well as treat the accompaning issues of tinnitus and headache .
thus , pre - operative radiological evaluation should be used for the assessment of feeding arteries , drainage vessels , numbers of fistulas , connected vascular structures and shunt flow volume in order to prevent any possible complications .
various techniques have been used to control the haemorrhage during surgery including percutaneous sutures of the feeding vessels , interlocking suture along the line of incision and use of tourniquet and intestinal clamp over the base of the flap .
a step - wise incision with careful pressure control is a useful method to control the scalp bleeding .
reflection of the pericranium along with the scalp flap prevents inadvertent rupture of the nidus . in avm , there may be significant pericranial component of the malformation as was evident in one of our cases .
due to the anomalous arteriovenous communication , avm must be completely eliminated because recurrence or enlargement is reported after an incomplete treatment .
endovascular treatment may be applied in order to decrease the haemorrhage and facilitate the surgical treatment or in the direct treatment of avms .
embolization of both feeders and nidus before surgery is safer than embolization of the feeders alone to reduce the risk of excessive haemorrhage .
three different approaches have been used to access the fistula , namely femoral transarterial , femoral transvenous and direct percutaneous catheterization of the feeding arteries or draining veins .
direct percutaneous catheterization of the fistula has been used whenever access through the artery or vein was not possible .
the percutaneous placement of thrombogenic coils is a simple and effective method to produce thrombosis of cirsoid aneurysm of the scalp , especially after slowing down the blood flow through transvascular intra - arterial embolization .
embolization and endovascular treatment may not be sufficient in the treatment of large scalp avms .
the most important step is total surgical excision without causing scalp necrosis and excessive blood loss .
the low- and high - flow scalp avms have different management protocol . a thorough clinical evaluation for differentiation of high - flow malformation from low - flow , should be followed by either a ct angiogram or mr angiogram and/or dsa . a high - flow avm with large size , multiple feeders , skin changes , skin necrosis / ulceration and haemorrhage are the right candidate for surgical treatment as it gives best chances of cure with better cosmetic result and less chance of recurrence .
appropriate management plan should be made on the basis of clinical data , investigation findings , available treatment options ( surgery , embolization + surgery or embolization alone ) and surgical expertise . in scalp avm , usually there are multiple feeders , even with single feeder cure without recurrence is probably rare .
moreover , per - operative feeder control is very easy for a skilled surgeon even if it needs a separate incision .
the scalp flap should be planned in such a way that the feeding arteries are preserved in the base of the scalp flap and the flap incorporate one or more normal non - feeding vessels so as not to jeopardize the flap blood supply once the feeding vessels are ligated . in case of unavoidable skin excision with avm
the flap should be raised along with the pericranium , the feeders should be identified , the pericranium and galea incised , the vessels traced distally towards the nidus and ligated , and/or coagulated and divided .
the pericranium and the galea should be circumferentially incised for excision of avm . wherever needed
, scalp should be reconstructed with scalp mobilization or rotational flap . in the management of low - flow vm patient age , size of lesion , presenting complains , skin thickness and intracranial venous sinus communication with direction of venous blood flow are important factors . in our series , among the three low - flow vms , two were under 1 year of age with a large lesion and the skin overlying the lesion was thin . in one case , scalp lesion was connected with superior saggital sinus . in the remaining case , patient wanted removal of mass . due to possible intracranial complications , and chances of scalp necrosis , bleeding , ulceration , and scarring and other systemic complication , we did not use interventional radiology or sclerosants in our series but with expert interventional radiologists these are very valuable tools of management of such lesions .
with pre - operative appropriate surgical planning , scalp avm and svm can be excised safely without any major complication . though some cases may be treated with percutaneus or endovascular embolization
, surgery remains the mainstay of treatment . in the event of scalp ulceration and haemorrhage ,
ct / mr angiography and/or dsa helps us to differentiate between low flow and high flow lesions as well as identify the feeders and the nidus .
 aims : scalp arterio - venous malformation ( avm ) and scalp venous malformation ( svm ) are rare conditions that usually need surgical treatment . here , 
 we have reported our experience of the surgical management of such lesions with a short review of the literature.materials and methods : in this prospective study , 11 patients with scalp avm and svm , who underwent surgical excision of lesion in our hospital from 2006 to 2012 , were included . 
 all suspected high - flow avm were investigated with the selective internal and external carotid digital subtraction angiogram ( dsa )  computed tomography ( ct ) scan of brain with ct angiogram or magnetic resonance imaging ( mri ) of brain with mr angiogram , and all suspected low - flow vascular malformation ( vm ) was investigated with mri of brain + mr angiogram . 
 eight were high - flow and three were low - flow vm.results:all lesions were successfully excised . 
 scalp cosmetic aspects were acceptable in all cases . 
 there was no major post - operative complication or recurrence till last follow-up.conclusions:with preoperative appropriate surgical planning , scalp avm and svm can be excised without major complication . 
INTRODUCTION
MATERIALS AND METHODS
Surgical treatment
RESULTS
Representative cases
Case 2
Case 5
DISCUSSION
CONCLUSION