James Laredo

Endovascular Management of Takayasu Arteritis: Is It a Durable Option?:

Interim outcome of endovascular management of Takayasu arteritis (TA) was determined retrospectively to assess the efficacy of angioplasty and/or stenting in 24 patients with 35 lesions in the chronic inactive stage. The renal (n = 16), subclavian/innominate (n = 11), and carotid (n = 5) arteries and abdominal aorta (n = 3) were treated. Twenty-six lesions achieved excellent to good target lesion revascularization with no residual or only minimal residual stenosis, whereas five had a moderate result. Thirty lesions achieved satisfactory hemodynamic correction. Restenosis was observed in 8 lesions treated with angioplasty alone (n = 18) and in 3 lesions treated with angioplasty and stenting (n = 17). All recurrent stenoses underwent successful reintervention without significant complication. Treatment of inactive stage TA lesions with angioplasty alone or with angioplasty and stenting results in excellent to good clinical improvement in the majority of patients (follow-up at 46.8 months). Endovascular therapy is a durable treatment option in patients with chronic inactive stage TA.

Classification of congenital vascular malformations: the last challenge for congenital vascular malformations

Congenital vascular malformations (CVMs) represent a group of vascular anomalies that are the result of defective development of the vascular system. Therefore, a CVM presents at birth as an inborn vascular defect arising from the various stages of embryogenesis and may involve one or more components of the peripheral circulation systems: arterial, venous, lymphatic and capillary systems. Naturally, the CVM may occur at different locations, conditions, shapes, extents and severities as one independent and predominant lesion (e.g. venous malformation) or as a mixed lesion with two or three different types of CVMs (e.g. haemolymphatic malformation). Hence, the CVM is a mixture of various vascular defects with different characteristics and behaviours, and often affects more than one vascular system; capillary, arterial, venous and/or lymphatic system. The CVM remains a most difficult and confusing diagnostic and therapeutic clinical entity due to the wide range of clinical presentations, degree of severity, location, unpredictable clinical course and erratic response to treatment with high recurrence due to its embryonic characteristics. To add to the confusion, around the turn of the century, most CVM conditions were initially described using name-based eponyms to describe a syndrome based on the clinical presentation (e.g. Klippel and Trenaunay syndrome; F P Weber syndrome; Servelle and Martorell syndrome; Hippel and Lindau syndrome and Sturge–Weber–Krabbe syndrome). Such old nosology and terminology of CVMs without proper information on aetiology, anatomy and pathophysiology failed to describe the appropriate defining characteristics among the CVMs. This old classification was based on clinical presentation alone and therefore was unable to provide proper anatomical and pathophysiological information that is required for evaluation, diagnosis and treatment. Hence, a new classification of CVMs was developed in order to adequately describe the anatomy and pathophysiology of these lesions. An initial classification of these CVM lesions was described by Malan and Puglionisi in 1964. They made the distinction between the different CVM types such as venous, arterial and other associated malformations for the first time. They also described a lesion involving the main vessel trunks and a peripheral lesion as separate entities. Subsequently, the Hamburg Classification was formulated during a workshop held in Hamburg, Germany, 1988. It was further modified to improve its clinical applicability providing additional critical information taking into account the stage during which developmental failure occurred during embryogenesis (Table 1). Meanwhile, further efforts were soon made by Mulliken et al. to differentiate two different kinds of vascular anomalies, the vascular malformation and vascular tumour (haemangioma). Both conditions are fundamentally different, not only from an anatomical, histological and pathophysiological standpoint, but also in their clinical behaviour. A haemangioma is a ‘self-limited’ vascular tumour, and vascular malformations are ‘self-perpetuating’ embryological tissue remnants. Mulliken also proposed a simple classification of the vascular malformation based on the flow characteristics: fast-flow and slow-flow lesions with additional subgroups. This idea was adopted together by the ISSVA (International Society for the Study of Vascular Anomalies) and updated officially through 1996 as ISSVA Classification (Table 2). Up until then, the vascular malformation was often mistakenly referred to as a ‘haemangioma’, which is the most frequently misused term to describe the CVMs (e.g. ‘cavernous/capillary’ haemangioma). The haemangioma is not a CVM but a ‘vascular tumour’ of benign nature that originates from endothelial cells. It usually appears in the early neonatal period. Haemangioma has a distinctive growth cycle characterized by a proliferation phase of early rapid growth followed by an involutional phase of slow regression. Unlike CVMs, haemangiomas undergo self-limited growth followed by subsequent involution that usually occurs before the age of 5–10 years. In contrast, the CVM is the result of a birth defect so that it continues to grow at a rate that is proportional to the growth rate of the body regardless of its type (venous, lymphatic, arterial, etc.). If the embryological defect occurred during the early stage of embryogenesis, the lesion will maintain its unique mesenchymal cell, angioblast characteristics. However, if the CVM

Venous malformation: Treatment needs a bird's-eye view.

A better understanding of congenital vascular malformations (CVMs) has evolved throughout the last two decades and is still evolving to address and correct many earlier misconceptions about this group of unique vascular lesions. Old terminology of these lesions based on old data has slowly fallen out of favour over the years and has given way to new terminology and classification of CVMs over the last two decades. There are still a few lingering issues regarding these vascular lesions that continue to be a source of confusion to clinicians involved in the diagnosis and treatment of CVMs. One area of confusion is the classification of an extratruncular venous malformation (VM) as a capillary or cavernous haemangioma. There is indeed a genuine ‘haemangioma’ with entirely different aetiology, biology and clinical characteristics. Haemangiomas and VMs are fundamentally distinct, not only in their anatomical, histological and pathophysiological findings, but also in their clinical courses. A haemangioma is not a congenital vascular lesion, but rather a vascular tumour that is derived from endothelial cells and develops in the postnatal period. In contrast, the VM is an embryological tissue remnant and is one type of CVM. The haemangioma has a unique characteristic of ‘self-limited’ growth along with a distinctive growth cycle characterized by a proliferation phase of early rapid growth, followed by an involutional phase of slow and gradual regression. The extratruncular VM, however, has an embryological characteristic of ‘self-perpetuating’ growth that is a result of a birth defect that arises during the ‘early’ stage of embryogenesis. Indeed, ‘extratruncular’ VM lesions retain their mesenchymal cell characteristics and potential for growth. These lesions are able to proliferate when challenged by a growth stimulus, both internal stimuli (e.g. female hormones, menarche and pregnancy) and external stimuli (e.g. trauma, injury, surgery, etc.). Therefore, the VM will not involute and regress like a haemangioma, but will persist through the life of the patient with the potential for a dreadful ‘recurrence’ which is the major clinical issue associated with an ill-planned surgical resection in particular. Indeed, over the last century we clinicians and our patients have paid a high price for neglecting this critical embryological aspect of the VM. Now, the idea Eivazi B et al. have proposed in their interesting manuscript ‘Phleboliths from venous malformations of the head and neck’ might fall into this same situation, where the biology of the VM was ignored. Certainly it sounds very appealing that direct surgical removal of the phleboliths from within the VM lesion would relieve symptoms and that anticoagulation treatment of the VM would prevent both recurrent phlebolith formation and phlebolith progression. The Achilles heel of this approach is the fact that the authors neglected the nature of the VM from a macro-view. Phlebolith formation is a natural outcome of intravenous coagulation induced by a ‘slow’ blood flow through the infiltrating, extratruncular VM lesions. Such slow, sluggish blood flow is due to the natural anatomy and peculiar structure of the VM, such that the phlebolith is a hallmark of the VM, and will remain so as long as the VM continues to exist. Simple removal of the phlebolith alone is, therefore, a mere stopgap measurement at best and is associated with very limited success in providing even temporary relief of the symptoms. Indeed, the VM lesion will continue to produce multiple phleboliths as its natural response. It is futile to attempt to remove one stone after another with such a high risk of bleeding which is often uncontrollable. Therefore, unless the VM lesion itself is eradicated, the phlebolith will continue to persist as the source of pain with no doubt. In addition, in the absolute majority of cases, the coagulopathy associated with the VM is not the ‘primary’ cause of the phlebolith formation. Phleboliths are the result of a ‘consumptive coagulopathy’ following the intravenous coagulation and stone formation due to sluggish flow and trapped blood within the VM lesions. Therefore, it is not as effective as those with primary coagulopathy, and also definitely not logical while allowing its primary cause to persist intact. Hence, systemic anticoagulation to treat the intravascular coagulopathy to prevent phlebolith formation and its progression within the VM is not always practical. Furthermore, there is always the possibility of the presence of another type of CVM lesion co-existing

Primary Lymphedema and Klippel-Trénaunay Syndrome

The majority of primary lymphedemas1,2 are due to a congenital, independent lesion of the lymphatic system resulting in dysfunction. Primary lymphedema due to a truncular lymphatic malformation (LM) has been thoroughly reviewed in Chap. 51.

Primary Lymphedema as a Truncular Lymphatic Malformation

Primary lymphedema has been treated successfully for many decades and is one of the two main types of chronic lymphedema; the other is secondary lymphedema.1,2 Primary and secondary lymphedema are two different diseases with different etiologies, clinical behavior, response to treatment, and prognosis. Throughout the last decade, substantial progress has been made in the understanding of the true nature of primary lymphedema as a type of congenital vascular malformation (CVM)3,4 affecting the lymphatic system.

Diagnosis and Management of Primary Phlebolymphedema

Phlebolymphedema (PLE) is the condition of combined insufficiency of both the venous and lymphatic systems of various etiologies. Primary PLE is a concomitant disruption of both the venous and lymphatic systems. The pathology is a result of a «hemolymphatic» malformation, and although the pathology is not well understood, diagnosis and proper clinical evaluation can improve outcomes. Phlebolymphedema can be managed more effectively when open and/or endovascular therapy is added to the basic compression therapy to control the CVI and CLI together. Primary PLE with CVI by the reflux of MV can be treated successfully with MV resection, while CVI by deep vein dysplasia can be treated with conventional compression therapy alone in the majority of cases.

Venous Physiology and Pathophysiology

Veins are essentially tubes with valves that function as passive conduits for blood flow. Venous valve function ensures unidirectional flow, emptying of venous compartments, physiologic drainage, and flow of blood from the superficial to deep system. Normal valve closure also produces dynamic fracturing of the gravitational hydrostatic pressure and is essential for proper function of the peripheral muscle pumps. Chronic venous disease produces hemodynamic disturbances which result in the inability of valves, pumps, and conduits in the venous system to maintain a normal venous pressure and normal flow. These disturbances are primarily caused by venous reflux, obstruction, or a combination of both.

Contemporary Indications and Controversies in Excisional Surgery

Once considered to be a relatively benign condition of limb swelling and associated with minimal morbidity, chronic lymphedema is a steadily progressive condition that not only affects the lymphatic system but all of the surrounding soft tissue, resulting in the development of dermato-lipo-fibrosclerosis.

Current Dilemmas and Controversies in Reconstructive Surgery for Lymphedema

Manual lymphatic drainage (MLD)-based decongestive lymphatic therapy (DLT) has long been the mainstay of treatment in the contemporary management of chronic lymphedema. Reconstructive lymphatic surgery is the best option for the management of chronic lymphedema when performed at the optimal time. It is also a viable option for lymphedema patients who have failed to respond to DLT alone.

Hemolymphatic Malformation: Mixed Form Congenital Vascular Malformation

Congenital vascular malformations (CVMs) are classified by vessel type according to the Hamburg classification (Table 16.1) [1–4]. In each class of vascular malformation, “extratruncular malformations” composed of small vessels intimately embedded in the host tissue and “truncular malformations” affecting individual large vessels are recognized [1–4].