Congenital Vascular Malformations with Arteriovenous Fistulae: Diagnosis and Treatment

Congenital Vascular Malformations with Arteriovenous Fistulae: Diagnosis and Treatment

Amr M. Salem, MD;1 Sameh Moustafa, MD;2 Mohamed E.Salem, PH.D;2

1) Vascular Surgery, Medical Research Institute, Alexandria University, Egypt.

2) Vascular Surgery, Faculty of Medicine, Alexandria University, Egypt.

Background: Arteriovenous malformations (AVMs) are congenital high flow vascular malformations (VMFs) composed of anomalous capillary beds shunting blood from the arterial system to the venous system. They are infiltrative causing destruction of the local tissue and often severe bleeding.

Objectives: The aim of this study was to review the clinical results of surgical treatment for

AVMs, with preoperative scleratherpy.

Patients and methods: 24 patients with AVMs and AVFs were treated in a period from October 2012 to March 2015. All patients were subjected to history taking, clinical examination, laboratory investigations and imaging studies which included: colored Duplex ultrasound, CTA, arteriography and direct haemangiography. All patients were treated by surgical excision after preoperative injections of sclerotherapy.

Results: Age incidence of the patients ranged between 1-35 years, 70.8% of them were below the age of 5 years and 80% of the patients were females. The common site for AVMs was the head and neck in 66.67%. Symptoms and sings included: cosmetic 83.33%, thrill and pulsating mass 75%, sensation of heat 66.67%, while pain, tissue necrosis, bleeding, port-win stain and cardiomegaly were the least symptoms and sings. All patients were treated by surgical excision after preoperative sclerotherapy.

Conclusions: Surgical treatment of AVM is a challenging issue for vascular surgeons. To minimize the complications related with surgery, a multidisciplinary team approach should be considered.

Key  words:  Arteriovenous  malformations  (AVMs),  vascular  malformations  (VMFs),

sclerotherapy and colored swellings.

Introduction:

Arteriovenous malformations (AVMs) are congenital high flow vascular malformations composed of anomalous capillary beds shunting blood from the arterial system to the venous system. They are infiltrative causing destruction of local tissue and often life-threatening   massive   bleeding.   AVMs are frequently found in several areas in the cervicofacial region. Little is known about the origin and pathogenesis of AVM. A defect in vascular stabilization is thought to cause AVM, but it remains unclear whether these lesions  are  primarily  congenital  in  origin or  acquired.  These  lesions  were  reported

presenting after trauma in adults.1–3

The arteriovenous fistula (AVF) is an abnormal connection between a high- pressure, high-resistance arterial system and low-pressure, low-resistance, high-capacity venous system.4 Arteriovenous fistulas may be congenital or acquired. The primary etiologies  of  acquired AVFs  are  traumatic and iatrogenic injuries. A small number occur spontaneously, usually from erosion of an aneurysm into an adjacent vein.5

Congenital  peripheral  arteriovenous fistula occurs in isolation or as part of a complex arteriovenous malformation (AVM). It manifests as an enlarging, pulsatile lesion

with   palpable   thrill   and   possibly   signs and symptoms of shunting. The old name "congenital AVF" is often replaced by the term arteriovenous malformation (AVM) of which multiple AVFs are a component.6 Although "arteriovenous malformation" (AVM) has been used to describe all congenital vascular malformations,  the  term  is  confusing, because not all malformations have abnormal arteriovenous shunting.4

The true characteristic of AVMs is not arteriovenous shunting but the abnormal development of one or several segments of the vascular system, arteries, veins, capillaries, or lymphatics. These lesions result from faulty development of blood vessels, and the arteriovenous connections, when present, are almost  invariably  multiple.4  The  hallmark of an AVM, called the nidus, is composed of arterial feeding vessels, micro- and macro- AVFs, and ectatic veins. The most common location for AVMs is intracranial, followed by limbs, trunk, and viscera.6

Acquired peripheral arteriovenous fistula occurs due to traumatic injuries,8 iatrogenic injuries,4  spontaneously acquired AVF4  and surgically created for hemodialysis.4

Pathophysiology  of  AVF  is  determined by the diameters of the artery and vein, the size and location of the fistula, the adequacy of the collateral circulation and competence of the valves in the distal veins. Although some fistulas reduce in size, or even close spontaneously, a large number of fistulas become more prominent over time with larger communications as a result of degenerative changes in the arterial wall.9–11

The natural course of AVM is early quiescence, late expansion, and ultimately infiltration and destruction of local soft tissue and bone. Common sites for occurrence are the midface, oral cavity, and limbs.2,12

Diagnosis of AVM is based upon clinical examination and imaging. A growing hypervascular lesion may have been present as a slight blush at birth. AVMs are often quiescent for many years and grow with the child.  Intermittent  expansion  will  suggest the diagnosis. Hormonal changes influences growth. The characteristics of an AVM will

be palpable warmth, pulse, or thrill due to its high blood flow. The overlying skin may have a well-demarcated blush with elevated temperature relative to adjacent skin.2,3,12-14

The goals of therapy for acquired AVFs are closure of the fistulous opening, restoration of normal hemodynamics, and reestablishment or maintenance of vascular continuity. The availability of both surgical and endovascular treatment of AVFs means that care can be individualized. Endovascular treatment is generally preferred when appropriate because it is less invasive. The major limitations of endovascular therapy are the occurrence of endoleaks, branch vessel and graft occlusion, intimal thickening, and stent deformation.7

Treatment of AVMs consists of embolization, surgical extirpation, or a combination of these modalities with tendency to go ahead with treatment rather than to observe waiting for these lesions to expand even if AVMs was isolated and small due to high recurrence rates. Treatment and timing are often individualized to the patient general and local medical states. Diffuse lesions are a lifelong problem. Long-term follow up with a multidisciplinary team is important for AVMs management. Intravascular embolization of AVM can be used alone or in combination with surgical excision. Absolute ethanol, polyvinyl alcohol, and other agents have been employed as AVM embolization materials. These agents selectively obstruct and destroy the arteries treated. Complications of this approach include local skin ulceration, soft tissue   necrosis,   mucosal   sloughing   and/ or nerve injury. Embolization provides temporary control of the disease and recurrence rate is high due to collateralization and recruitment of new vessels to support an undetected portion of the "nidus". Frequent serial embolizations may improve patient outcomes. In general, surgical management of AVMs requires preoperative supraselective embolization  24-48  hours  before  surgery (this helps control blood loss & show surgical margins of the lesion). Surgery requires judicious removal of tissue, and complex reconstructive techniques. In focal lesions, surgical  excision  has  been  shown  to  cure

Case 1                                                                      Case 1

Figure (1): Vascular malformation with arteriovenous fistula of the left hand in a 6 years old female child.

Figure (2): Brachial arteriography of vascular  malformation  with  AVFs  of  the palm of the left hand shows the ulnar, radial arteries and superficial veins denoting the presence of Avshunts.

Case 1                                                                                 Case 2

Figure (3): Shows complete healing of the wound after excision of the vascular male formations (VMFs) swelling of the left hand.

Figure (4): VMF of the left eyebrow and left side of the face with AVF. It the swelling was pulsating.

Case 2

Case 3

Figure   (5):   Showing   healed   scar   after

surgical excision.

Figure (6): Showing VMF of the scalp, which was pulsating in 2 years old a female child. Injection of sclerotherapy 3 times, 3 weeks interval before operation.

AVMs but recurrence rates are 93% in diffuse

AVMs.15,16

Aim of the work:

The aim of this study was to review the clinical results of surgical treatment for AVMs, with preoperative scleratherpy.

Case 3                                                                      Case 4

Figure (7): Complete excision of the scalp

mass. Closure of the wound with Z-plasty.

Figure (8): VMF of the upper lip in 1½ years old male child.

Case 4                                                           Case 5

Figure (9): Complete excision of the VMF of the upper lip with reconstruction of the upper lip.

Figure (10): Huge pulsating anterior abdominal wall VMF 30 × 20 cm size in 35 years old adult male.

Case 5                                                          Case 5

Figure     (11):     Direct     haemangiography

showing the extend and depth of the lesion.

Figure (12): Complete healing of the wound after surgical excision and preoperative injection of sclerosing material (4 times, once every 3 weeks).

Patients and methods:

Twenty four patients with vascular malformations and arteriovenous fistulae, were admitted to the Alexandria Main University  Hospital,  Faculty  of  Medicine and Medical Research Institute, Alexandria University, Egypt from October 2012 to March 2015.

All patients were subjected to the following:

1- History taking and clinical examination, every patient was examined as regard age, sex, site of the lesion  and clinical presentations

2- Laboratory  investigations  include: Hb%, bleeding time, coagulation time and platelet count.

Case 6

Case 6

Figure (13): VMF of the lower lip in 23 years

old adult male.

Figure (14): The lower lip after excision of the VMF and reconstruction of the lower lip.

Case 7

Case 7

Figure (15): Shows VMF of the right eyebrow and forehead. The swelling is pulsating in a 3 years old female child.

Figure (16): Partial regression after injection of ethanolamine, 4 injections with 3 weeks intervals.

Case 7

Figure (17): Complete excision of the VMF with reconstruction of the right eyebrow.

Table (1): age incidence in years

Table (2): Sex incidence.

Table (3): Common sites of arteriovenous fistulae

Table (4): Symptoms and signs of arteriovenous fistulae

Table (5): Indications for surgery

3- Imaging studies: colored duplex ultrasound, CTA, Arteriography and direct haemangiography

4- Treatment and timing were often individualized. Treatment of AVMs consisted of preoperative sclerotherapy followed by surgical excision. Sclerotherapy was done by using ethanolamine injection, 2-5ml/injection according to the size of the lesion. Two to four sessions were used with interval of 3 weeks to minimize bleeding during operation. Surgical excision after control of the feeding and communicated arteries with reconstruction of the local tissues were done.17–18

Results:

Age incidence:

Table (1) shows the age incidence, 70.8% of patients were below the age of 5 years. While, no patient was seen above 35 years.

Sex incidence:

Table (2) shows the sex incidence, 79.2%

of patients belonged to the female sex.

Sites of arteriovenous fistulae:

Table (3) shows that head and neck were the common sites for arteriovenous fistulae in 66.67% of patients. While, trunk was the least site (8.33%).

Symptoms and signs of arteriovenous fistulae: Table (4) shows that cosmetic problems were the commonest symptoms and signs of

arteriovenous fistulae in 83.33% of patients.

Indications for surgery:

Table (5) shows that cosmetic problems was the 1st indication for surgery. It represented 75% of cases. While, pain was the last indication for surgery, it represented

4.2%.

Figures (1–17) represented some cases of the study before and after surgery.

Discussion:

AVM has been a challenging disease for both the doctors and the patients. It can be asymptomatic, but it can create many problems

such as cosmetic disfigurement, pain, tissue necrosis, bleeding, limb length discrepancy, heart failure and even psychiatric problems. Although advanced diagnostic techniques now give us more information about AVM than before, the treatment of AVM has been still limited. It is usually not a life threatening condition and the physician does not want to face the possibility of serious complications during treatment that can be life threatening. Treatment of AVM has a high recurrence rate and incomplete treatment of AVM can make the lesions larger than before treatment in a short period of time.17

Surgical treatment alone can cause massive bleeding during the operation. Most surgeons recommend    preoperative    sclerotherapy.18

Surgeons should consider several important points during the surgical treatment of AVM. The first is that the nidus of AVM should be completely removed for achieving a complete cure of AVM. The remnant AV M may grow and get bigger than before treatment within a  short  period.  Ligation  of  the  feeding artery without removal of nidus should be avoided. In this case, other collateral vessels and quiescent AVMs will grow fast and the AVM may get bigger than before. If the feeding artery of the AVM is ligated, further sclerotherapy was impossible because there will be no accessible rout for sclerotherapy.19

All AVMs do not need to be treated if they do not cause serious problems. If the AVM itself causes problems like cosmetic problems, compression to adjacent structure, or complications like the ‘steal' phenomenon, bleeding or heart failure, then treatment of the AVM should be considered. The AVM is generally not a life threatening disease, but massive bleeding or wide tissue necrosis related to surgery and/or sclerotherapy might be life threatening.17

In conclusion, surgical treatment of AVM is a challenging issue for vascular surgeons. To minimise the complications related with surgery, a multidisciplinary team approach should be considered.

Reference:

1-   Richter  GT,  Friedman  AB:  Hemangiomas