Management of an Arteriovenous Malformation
Arch Facial Plast Surg. 2003;5:334-337.
Arteriovenous malformations 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 arteriovenous malformations are rare aberrations in vascular morphogenesis. Their rarity and 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 lymphatic malformations as well as arteriovenous VMs (AVMs). Each of these types of VM 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 pulsed dye laser therapy for capillary VMs, sclerotherapy, or Nd:YAG laser therapy for principally venous VMs, and surgical resection of lymphatic VMs. We describe a patient with an AVM, which may be the most recalcitrant VM to manage successfully and which has the greatest potential morbidity and related mortality.
An otherwise healthy 12-year-old girl presented for a second resection of an AVM that involved her left auricle, principally the superior and middle aspect, and that extended postauricularly. She was born with a discolored left ear that began to demonstrate a discrete, localized swelling by the time she was 3 months old. The size of the AVM slowly expanded over time but underwent a more rapid development when the patient was 6 years old, without an antecedent traumatic stimulus for this growth. However, at that time, her mother did not seek medical attention for her.
At the age of 8 years, the patient began to experience episodes of ulceration and hemorrhage that were arrested by diligent application of pressure (Figure 1). At that time, she received 2 treatments with a pulsed dye laser at 6-month intervals, with evidence of some stabilization and regression, although she did have subsequent episodic hemorrhages. By 10 years of age, she had a significantly expanded, ulcerated lesion that was a concern from a bleeding and hygienic perspective. Her mother was advised that the patient should undergo embolization and a total auriculectomy but declined as to the extent of surgery, favoring only a partial resection even though the risk of recurrence had been clearly outlined for her. The patient underwent a presurgical embolization of her principal feeding vessel, the superficial temporal artery, using metallic coils, and then an unremarkable surgical resection.
One year after the initial operation, the patient underwent another pulsed 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 2-year period, and the patient began to experience renewed bleeding, which alarmed her mother. At this point, her mother was advised that the best, and most definitive, course of action would be a completion auriculectomy after embolization. Unfortunately, she failed to pursue the matter diligently, and it took 6 months of persistence from the medical staff before appropriate surgical care was rendered.
After this delay, the patient, who was now 12 years old, underwent a second course of embolic therapy of the postauricular artery with polyvinyl alcohol of particulate sizes ranging from 200 to 450 µm 1 day before surgical intervention (Figure 2A and B). 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 patient 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 mL during the 3 -hour operation but remained hemodynamically stable with volume expansion. 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 wet-to-dry dressing changes 2 times a day. After a 3-week period, the entire defect was healed, and at the 3-month follow-up visit, complete epithelialization was noted except for a small area of granulation tissue that developed at the superior margin of the remaining auricle (Figure 6). At the time of this writing, we had decided to wait an entire year before contemplating prosthetic reconstruction in order to encourage complete healing and wound contraction.
The seminal treatise of Mulliken and Glowacki1 in 1982 first shed light on the unique characteristics that differentiated hemangiomas from VMs. Hemangiomas, the most common type of vascular anomaly, are marked by the high endothelial turnover that makes them both true neoplasms, albeit benign, and distinct from VMs. Hemangiomas also exhibit a characteristic pattern of growth: they are usually not present at birth but manifest within 1 month of life, rapidly proliferate during the first year of life, and then undergo a gradual involution. Vascular malformations, on the other hand, are evident at birth and increase in size proportionate to the individual’s growth, except when they are spurred to expand rapidly as a result of 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 owing to higher inflowing pressures as well as to recruitment of local vessels in a collateral fashion. Given all these defining characteristics, clinicians should be able to discern which vascular anomaly they are 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 than satisfactory. 2 The literature is replete with outdated and confusing terminology, which further frustrates our ability to comprehend these entities. Because of the infrequent occurrence of AVMs, some studies have endeavored to evaluate all VMs collectively, which is by any measure a fruitless exercise. There are few retrospective studies in which the series is large enough to help elucidate the nature of AVMs and to 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 a 69% success rate for 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 al3 chose to examine only 6 representative cases from that series and underscored the efficacy of multimodality therapy, including embolization, judicious resection, and reconstruction with both local and expanded flaps.
Often, incomplete resection of the AVM will lead to recurrence and at times will 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 proved to be a mainstay of therapy, especially for complicated and extensive lesions that would otherwise be 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 presurgical 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 the caliber of vessel he or she should encounter. In our hands, the most expeditious method of accomplishing this objective has been the 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 any psychological trauma that the vascular lesion may engender and may circumvent the development of a lesion that has grown in size, we believe that a more mature child, preferably before 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 before any ablative surgery is undertaken, as the expander device will easily extrude through the defect if it is placed and expanded 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 and 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 to 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 considered as an alternative. After a sufficient period of adequate healing, the ultimate goal of reconstruction is an auricular prosthesis supported by titanium implants, a method that we believe offers the best advantage for rapid repair, with the most natural aesthetic result.
We hope that this brief report on 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.
Corresponding author: Edwin F. Williams III, MD, Williams Center for Facial Plastic Surgery, 1072 Troy-Schenectady Rd, Latham, NY 12110 (e-mail: email@example.com ).
Accepted for publication February 20, 2002.
From the Section of Facial Plastic and Reconstructive Surgery, Division of Otolaryngology, Department of Surgery (Drs Lam, Dahiya, and Williams ), Albany Medical College, and Stratton Veteran Affairs Medical Center (Dr Lam), Albany, NY; and Williams Center for Facial Plastic Surgery, Latham, NY (Dr Williams ).
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4. Simons ME. Peripheral vascular malformations: diagnosis and percutaneous management. Can Assoc Radiol J. 2001;52:242-251.