The Vascular Birthmarks Foundation
Management of an Arteriovenous Malformation
Samuel M. Lam, M.D.*, Ravi Dahiya, M.D.**, Edwin F. Williams, III, M.D.***
*Clinical Instructor, Division of Otolaryngology, Department of
Surgery, Albany Medical College, Albany, New York
Stratton Veteran Affairs Medical Center, Albany, New York
**Albany Medical College, Albany, New York
***Clinical Associate Professor, Division of Otolaryngology, Department
Albany Medical College,
Albany, New York
Chief of Division,
Facial Plastic & Reconstructive Surgery,
Albany Medical College,
Albany, New York
Williams Center for Facial Plastic Surgery,
Latham, New York
Arteriovenous malformations (AVMs) represent a unique challenge to the facial plastic and reconstructive surgeon. Unlike other vascular anomalies, such as hemangiomas or capillary vascular malformations (or port-wine stains), true AVMs are rare aberrations in vascular morphogenesis. Their rarity and the high propensity toward bleeding and recurrence combined with the potential for life-threatening rupture may make the occasional surgeon who dares to resect these lesions rightfully less than intrepid in his endeavor.
Vascular malformations (VMs) should not be viewed as a monolithic disease, as the term embraces the diverse entities of capillary, arterial and arterio-venous, venous, and lymphatic malformations. Each of these types of VMs exhibits its own natural history and mandates a treatment regimen tailored to the respective, unique characteristics of that VM. A detailed, schematic analysis of treatment protocols lies beyond the scope of this case report, but any serious reconstructive surgeon who is determined to master the intricacies of VMs should be familiar with all the manifestations of VMs and the wide range of treatment options available, including pulse-dye laser therapy for capillary VMs, sclerotherapy or ND:Yag laser therapy for principally venous VMs, and surgical resection of lymphatic VMs. This case study is concerned with an AVM, which may be the most recalcitrant VM to manage successfully and which has the greatest potential morbidity and related mortality.
Report of a Case
An otherwise healthy 12-year-old girl presented for a second resection of her AVM that involved her left auricle, principally the superior and middle aspect, and that extended postauricularly. The child was born with a discolored left ear that began to demonstrate a discrete, localized swelling by 3 months of age. The size of the AVM slowly expanded over time but underwent a more rapid development at the age of 6 years without an antecedent traumatic stimulus for this growth. However, her mother did not seek medical attention at this time.
At the age of 8, the child began to experience episodes of ulceration and hemorrhage that were arrested by diligent application of pressure (Figure 1). At this time, she received two treatments with the pulse-dye laser at 6-month intervals with evidence of some stabilization and regression, although she did suffer subsequent episodic hemorrhages. By 10 years of age, the child had a significantly expanded, ulcerated lesion that was a concern from a bleeding and hygienic perspective. The mother was advised that her child should undergo embolization and a total auriculectomy but declined as to the extent of surgery, favoring only a partial resection despite the risk of recurrence clearly outlined for her. The child underwent a pre-surgical embolization of her principal feeding vessel, the superficial temporal artery, using metallic coils, and then an unremarkable surgical resection.
A year after the initial operation, she had another pulse-dye laser treatment that lightened the color of the AVM and was thought to have forestalled any further bleeding episodes. However, the ineluctable recurrence of the AVM became manifest over a two-year period, and the child began to experience renewed bleeding that alarmed her mother. At this point, the mother was advised that the best, and most definitive, course of action would be a completion auriculectomy after embolization. Unfortunately, the mother failed to pursue the matter diligently, and it required 6 months of persistence from the medical staff before appropriate surgical care was rendered.
After this delay, the 12-year-old child was submitted to repeat embolic therapy using polyvinyl alcohol (PVA) of particulate sizes ranging from 200 to 450 microns of the postauricular artery one day prior to surgical intervention (Figure 2A & 2B). However, given the proximal position of the previous coils, the superficial temporal artery could not be safely and effectively embolized (Figure 2C). The following day, the child was taken to surgery (Figure 3) and the remainder of her ear and a portion of her postauricular region were excised in a controlled hemostatic fashion using clips and ligatures (Figure 4). The deep extent of dissection was terminated at the level of the deep temporalis fascia, which proved to be an avascular cleavage plane. Despite best efforts, the patient sustained a blood loss of 1600 cc during the 3 ½-hour operative case but remained hemodynamically stable with volume expansion. In order to minimize the defect, a superiorly-based rotation-advancement flap was performed leaving a total defect of 3 x 5 cm (Figure 5). The remaining lobule was partially affixed to the posterior-inferior aspect of the defect to the extent that the external auditory canal would not be tethered and narrowed by the tissue advancement. A mastoid-style pressure dressing was then applied to the cranium.
The partially closed wound was allowed to heal by secondary intention and with the diligent application of twice daily wet-to-dry dressing changes. After a three-week period, the entire defect was healed, and at three-month follow-up, complete epithelialization is noted except for a small area of granulation tissue that developed at the superior margin of the remaining auricle (Figure 6). At this time, the authors intend to permit an entire year to transpire before contemplation of prosthetic reconstruction in order to encourage complete healing and wound contraction.
The seminal treatise of Mulliken and Glowacki in 1982 first shed light on the unique characteristics that differentiated hemangiomas from vascular malformations.1 Hemangiomas, the most common type of vascular anomaly, are marked by the high endothelial turnover that render them both true neoplasms, albeit benign, and distinct from VMs. Hemangiomas also exhibit a characteristic pattern of growth: usually not present at birth but manifest within one month of life, rapidly proliferate during the first year of life and then undergo a gradual involution. VMs, on the other hand, are evident at birth and increase in size proportionate to the individual’s growth, except when spurred to expand rapidly due to hormonal factors, trauma, or infection. Depending on the principal type of vessel, the VM may develop more or less rapidly, with arterial-based VMs naturally inclined to enlarge more readily due to higher inflowing pressures and also to recruitment of local vessels in collateral fashion. Given all these defining characteristics, the clinician should be able to discern which vascular anomaly he is confronting without the aid of sophisticated imaging or retrieval of biopsy material.
Unlike other types of vascular anomalies, AVMs are troublesome in many respects. Their rarity precludes a thorough and meaningful scientific investigation; their unpredictable course limits any useful prognostic pronouncements; and the generally poor treatment outcomes make intervention less then satisfactory.2 The literature is replete with outdated and confusing terminology that further frustrate our ability to comprehend these entities. Due to the infrequent occurrence of AVMs, some studies have endeavored to evaluate all VMs collectively, which is by any measure a fruitless exercise. Few retrospective studies exist that constitute a sufficiently large series to help elucidate their nature and better define treatment protocols.
One retrospective review of 81 patients with extracranial AVMs of the head and neck region demonstrated an overall cure rate of 60%, with 69% success in small malformations that underwent excision alone and 62%, for extensive malformations that required combined embolization and resection.2 Outcomes were not affected by stage of disease, sex, or treatment strategy. Most studies however have far fewer reported cases than the aforementioned review. Although distilled from an extensive series of 300 facial AVMs, Bradley et al. chose to examine only six representative cases from that series and underscored the efficacy of multimodality therapy, including embolization, judicious resection, and reconstruction with both local and expanded flaps.3
Oftentimes incomplete resection of the AVM will lead to recurrence and at times spark growth in the lesion with unanticipated vigor. The case discussed herein is representative of the consequences of failing to follow this guiding tenant of complete resection. Preoperative embolization has proven to be a mainstay of therapy, especially for complicated and extensive lesions that would otherwise by surgically inoperable or unsafe.4 The fact that the AVM in this case had been previously embolized as well as resected made repeated embolization of limited benefit despite the development of collateral vasculature. Significant intraoperative blood loss corroborated the inadequate pre-surgical embolization. To minimize intraoperative hemorrhage that would jeopardize patient welfare and obscure the tissue bed, the surgeon should progress in a deliberate fashion, carefully ligating and controlling every vessel, no matter what caliber, he should encounter. In our hands, the most expeditious method of accomplishing this objective has been use of hemostatic clips on small vessels, silk ligatures on larger tributaries, and silk-suture ligatures when the retracted vessel cannot be easily located. The timing of surgery is another important consideration. Although earlier surgical intervention may preclude or minimize psychological trauma that the vascular lesion may engender and may circumvent the development of a lesion that has grown in size, we feel that a more mature child, preferably prior to puberty, may be better equipped hemodynamically to withstand the substantial intraoperative blood loss.
After tissue ablation, the surgeon must then reconstruct the defect, or permit healing by secondary intention. The scalp region is relatively inelastic and is difficult to close with simple rotation-advancement flaps. Preoperative tissue expansion is a viable alternative; and if this method of reconstruction is chosen, the tissue expander must be placed and serially expanded prior to any ablative surgery, as the expander device will easily extrude through the defect if done after removal of the lesion. At times, tissue expansion may be more problematic, considering the limited compliance of pediatric patients and the necessity for another operation. However, in a more cosmetically sensitive area such as the midface, tissue expansion or serial excision are equally viable options, and healing by secondary intention may be less appropriate in that circumstance. In this case, a rotation-advancement flap was performed to reduce the size of the defect and expedite healing by secondary intention, which is usually quite swift. Given the less cosmetically sensitive area, we thought that this would be the best compromise in reconstruction. Skin-graft coverage of the remaining defect is a reasonable method of reducing morbidity and may be seriously entertained as an alternative. After a sufficient period of adequate healing, the ultimate goal of reconstruction is an auricular prosthesis supported by titanium implants – which we feel will offer the best advantage for a rapid repair with the most natural aesthetic result.
The authors hope that this brief treatment of a difficult disease will encourage the reader to pursue more in-depth study and to tackle this formidable challenge intelligently and with the enlisted services of a reliable interventional radiologist.
1. Mulliken JB, Glowacki J. Hemangiomas and vascular malformations in infants and children: a classification based on endothelial characteristics. Plast Reconstr Surg. 1982;69:412-22.
2. Kohout MP, Hansen M, Pribaz JJ, Mulliken JB. Arteriovenous malformations of the head and neck: natural history and management. Plast Reconstr Surg. 1998;102:643-654.
3. Bradley JP, Zide BM, Berenstein A, Longaker MT. Large arteriovenous malformations of the face: aesthetic results with recurrence control. Plast Reconstr Surg. 1999;103:351-361.
4. Simons ME: Peripheral vascular malformations: diagnosis and percutaneous management. Can Assoc Radiol J. 2001;52:242-51.