Focal venous hypertension as a pathophysiologic mechanism for tissue hypertrophy, port-wine stains, the Sturge-Weber syndrome, and related disorders: proof of concept with novel hypothesis for underlying etiological cause (an American Ophthalmological Society thesis)

PURPOSE

To provide an in-depth re-examination of assumed causes of tissue hypertrophy, port-wine stains, and the Sturge-Weber, Cobb, Klippel-Trénaunay, and related syndromes to support an alternative unifying pathophysiologic mechanism of venous dysplasia producing focal venous hypertension with attendant tissue responses; to provide proof of concept with new patient data; to propose a novel etiological hypothesis for the venous dysplasia in these syndromes and find supportive evidence.

METHODS

Data from 20 patients with port-wine stains and corneal pachymetry readings was collected prospectively by the author in an institutional referral-based practice. The literature was searched using MEDLINE, and articles and textbooks were obtained from the bibliographies of these publications.

RESULTS

Newly obtained dermatologic, corneal pachymetry, fundus ophthalmoscopic, ocular and orbital venous Doppler ultrasonography, and magnetic resonance imaging findings in patients with the Sturge-Weber syndrome or isolated port-wine stains, along with published data, reveal diffusely thickened tissues and neural atrophy in all areas associated with venous congestion.

CONCLUSIONS

Contrary to traditional understanding, signs and symptoms in the Sturge-Weber and related syndromes, including both congenital and acquired port-wine stains, are shown to arise from effects of localized primary venous dysplasia or acquired venous obstruction rather than neural dysfunction, differentiating these syndromes from actual phacomatoses. Effects of focal venous hypertension are transmitted to nearby areas via compensatory collateral venous channels in the above conditions, as in the Parkes Weber syndrome. A novel underlying etiology-prenatal venous thrombo-occlusion-is proposed to be responsible for the absence of veins with persistence and enlargement of collateral circulatory pathways with data in the literature backing this offshoot hypothesis. The mechanism for isolated pathologic tissue hypertrophy in these syndromes clarifies physiologic mechanisms for exercise-induced muscle hypertrophy to occur via venous compression and increased capillary transudation.

Klippel-Trenaunay syndrome: a multisystem disorder possibly resulting from a pathogenic gene for vascular and tissue overgrowth

Klippel-Trenaunay syndrome is characterized by a triad of varicose veins, cutaneous capillary malformation, and hypertrophy of bone and soft tissue. Appropriate evaluation and treatment of children displaying features of the disease may minimize morbidity. The clinical appearance, etiology, genetics, diagnostics, and treatment of Klippel-Trenaunay syndrome are herein explored.

Klippel-Trenaunay syndrome

The association of three physical findings including capillary malformation, varicosities, and hypertrophy of bony and soft tissues corresponds to Klippel-Trenaunay syndrome. This triad of findings, described by the two French physicians Klippel and Trenaunay in 1900, differs from Parkes-Weber syndrome, in that Klippel-Trenaunay syndrome does not incorporate significant hemodynamic arteriovenous fistulas. Generally, management of this disease process should be individualized. Surgery should be considered in cases where skin ulcerations lead to persisting and recurrent bleeding, or where digital deformities lead to functional disabilities or where significant limb overgrowth leads to both functional and psychological impairment. Persistent hematochezia, hematuria, and vaginal and esophageal bleeding are considered indications for surgical intervention. Recurrent attacks of thrombophlebitis and cellulitis are treated medically with antiinflammatory agents and antibiotics. Otherwise, management of this syndrome is generally conservative, consisting of psychological encouragement, reassurance, and the continued use of graduated compressive stockings for varicosities and intermittent pneumatic compression pumps for lymphatic edema.

Klippel-Trénaunay syndrome. An unusual presentation of unilateral leg edema

Klippel-Trénaunay syndrome is a rare congenital condition that classically presents as a triad of varicosities, bone or soft-tissue hypertrophy, and cutaneous hemangiomas. The authors describe a case of this disease in an otherwise healthy patient with unilateral leg edema and intermittent bleeding from prominent ankle varicosities. The diagnosis was made on the basis of clinical presentation, diagnostic studies, and a comprehensive literature review. An overview of the pathology, treatment, and prognosis of this disease is provided.

Klippel-Trenaunay syndrome

The Klippel-Trenaunay syndrome, typically characterised by the triad of cutaneous haemangioma, venous varicosities, and limb hypertrophy, may also have a formes frustes presentation, with absence of the cutaneous naevus. A case is reported in a 75-year-old woman with a presumptive diagnosis of renovascular hypertension.

The etiology of the Klippel-Trenaunay syndrome

The etiology of the Klippel-Trenaunay syndrome (KTS) remains obscure. Although venous hypertension secondary to deep venous obstruction has been suggested as a cause, recent studies have demonstrated that most patients have unimpeded venous drainage. Calf blood flows have been measured in 33 patients with KTS using venous occlusion plethysmography. Although all flow rates were within normal limits, flow in affected limbs was invariably greater than in normal limbs (p less than 0.001), and this is related to the presence of the nevus. Biopsies of subcutaneous veins demonstrate the histological features of a response to chronically raised flow. The authors suggest that KTS is caused by mesodermal abnormality during fetal development, leading to the maintenance of microscopic arteriovenous communications in the limb bud, as a result of which the triad of nevus, hypertrophy, and superficial varices is produced. Deep venous abnormalities occur pari passu with the triad and are not responsible for its development.

Klippel-Trenaunay syndrome: a review

The Klippel-Trenaunay syndrome is a triad of congenital anomalies characterized by a vascular nevus, varicose veins and bony and soft-tissue hypertrophy. Although the syndrome is uncommon, initially the condition appears as a skin blemish or varicose veins. To avoid errors in management, it is important to recognize the syndrome. In this paper the authors outline the presentation, investigation and management of Klippel-Trenaunay syndrome and describe four cases of their own. One form of Klippel-Trenaunay syndrome, in which all the anomalies of the triad are important, in which direct signs of a large arteriovenous shunt are present and for which the surgical approach is difficult, is Parkes-Weber syndrome. Lack of reports in the world literature on long-term follow-up leaves many unanswered questions regarding prognosis and management.

[Klippel-Trenaunay syndrome of the upper extremity. Apropos of 2 cases]

The authors report a case of Klippel-Trenaunay syndrome in the upper limb of a 27 years old migrant manual worker. This very typical case due to agenesis of the humeral vein is used as a basis for a discussion of the theories of Servelle on the pathogenesis of this syndrome.

Hemimegalencephaly with hemihypertrophy (Klippel-Trénaunay-Weber syndrome)

A 17-year-old Japanese girl had right hemihypertrophy, vascular nevus of the right side of the body, right hemimegalencephaly, multiple haemangiomatosis, varicosis and chronic proliferative glomerulonephritis. The hypertrophied side of the cerebrum showed no malformations. Quantitative studies showed no significant differences between the two cerebral hemispheres in size, form, density or DNA content of nerve and glial cells. The hemimegalencephaly seemed to be due to an increase in the absolute number of nerve and glial cells in the ipsilateral cerebral hemisphere. Eight cases of hemihypertrophy with hemimegalencephaly have been reported to date, in all of them hemihypertrophy and hemimegalencephaly were on the same side. This condition seems to be due to unilateral overproduction of neuroblasts and glioblasts or hindrance of the normal loss of excess neurons, which may be induced by hemihypertrophy of the mesenchyme surrounding the CNS.

[Klippel-Trenaunay, syndrome or disease]

Two cases which were clinically typical of the Klippel Trenaunay syndrome and in which the integrity of the deep venous system demonstrated by phlebography form the basis for the author's discussion of the various theories and classifications which have been put forward up to now. The authors favour Schobinger's opinion, according to which three varieties of the Klippel Trenaunay syndrome are recognised. Malan's anatomoclinical classification has been adopted : this permits the grouping together of the numerous variations possible in this type of dysplasia.