CAPS
OVERVIEW
Presented first are explanations that we find as regular folks, using publicly available information. It’s what we do, no shame in it. I am not alone in having witnessed doctors –— new to us, new to our visible symptoms –— Google the diagnosis our doctor gave us.
There is a key difference between the new doctor and us. They have a medical degree and likely had at least one conversation in a class on Vascular medicine. They may have have visited the library and pulled Dr. Milikin’s book, considered by many the medical bible for Vascular Medicine.
We will go further than a Google Search. Knowing what level of information is being relied on is important to due diligence — i.e. advocating for ourselves. We are born rare and living rare. Likewise, children who just want to be a regular kid.
We proceed, for a moment, with Google:
“Congenital vascular malformations are structural birth defects (present in utero) caused by errors in vascular development. They consist of normal, non-multiplying endothelial cells, they do not spontaneously regress, and they generally grow in proportion to the child’s growth.
These are classified based on the type of vessel and blood flow:
- Malformations Associated with other Anomalies: Such as Klippel-Trenaunay syndrome or Parkes-Weber syndrome.
- Simple Malformations: Affecting only one type of vessel (Capillary, Lymphatic, Venous, or Arterial).
- Combined Malformations: Involving multiple vessel types (e.g., Capillary-Lymphatic-Venous Malformations).
- Malformations of Major Named Vessels“
[1, 2, 3, 4, 5 6, 7, 8, 9, 10] …Google reported these as their sources
— end of Google response to What is… —
There is a full stop in the above characterization, despite the sourced references. The above is oversimplified to the point of being misleading.
What follows is an example pushing back on simplistic, Google-like searches, no matter who is at the computer or desk.
Google responded: “You are completely correct. The previous explanation barely scratched the surface, and treating vascular anomalies as a basic binary list is inadequate for families and patients navigating these life-altering conditions.”
If you arrived here, on this page, and it’s early in your walk through our website, please know that we push to get a transparent, objective, and accurate overviews and respective details. Our deep dives, in addition, are not for the faint of heart. Our motto: a picture worth a thousand words.
This Overview is closer to the real story
Two world standards: The Hamburg Classification model and ISSVA Classification, combined, provide a precise framework that reveals why our lesions behave the way they do. When we layer these systems together, it’s clearer why Multidisciplinary Teams (MDTs) and more than Google medicine are mandatory for accurate diagnosis and safe treatment.
[1, 2, 3, 4]
The Molecular Revolution: ISSVA Updates
The newer updates from the International Society for the Study of Vascular Anomalies (ISSVA) shifted from a purely descriptive system to a biologically and genetically driven model.
[5]
- Genetic and Molecular Anchoring: Rather than classifying malformations just by how they look, ISSVA incorporates specific genetic mutations (e.g., PIK3CA, TEK, AKT1, MAP2K1). This means two lesions that look identical on an MRI might require completely different targeted medical therapies (like Sirolimus or Alpelisib) because their genetic drivers are entirely different.
[6, 7] - The PUVA Category: ISSVA formally tracks Potentially Unique Vascular Anomalies (PUVA). These are complex, aggressive, or borderline lesions that do not cleanly fit into a “tumor” or “malformation” box, requiring custom therapeutic approaches.
[8, 9, 10] - Complex Lymphatic Syndromes: The updates specifically delineated Complex Lymphatic Anomalies (CLAs), separating entities like Gorham-Stout Disease (GSD), Kaposiform Lymphangiomatosis (KLA), and Central Conducting Lymphatic Anomalies (CCLA), which carry vastly different clinical risks and systemic complications. [11]
The Surgical Reality: The Hamburg Classification
While ISSVA focuses on cellular biology and genetics, the Hamburg Classification focuses heavily on embryology and anatomy. It answers the critical surgical question: How did the vessel mis-form during embryonic development, and what is its architecture?
[1, 2, 3, 4]
We who are Rare are the World, from Australia to Hawaii, the northern most reaches of Canada and Europe, and deep into Africa and South American. The duality that is the Hamburg and ISSVA models reminds us that science is not only complex, but discovered by many, many with different frames of reference.
Hamburg divides every vascular malformation into two profound structural forms: [1]
| Functional Aspect [1, 2, 3, 4, 5] | Extratruncular Forms | Truncular Forms |
|---|---|---|
| Embryonic Origin | Arise early in embryonic life during the reticular stage. | Arise later in embryonic life during main vascular trunk formation. |
| Tissue Characteristics | Behave like primitive, undifferentiated tissue remnants. They retain a “mesenchymal cell memory”. | Consist of mature, fully developed vessels that suffered a developmental arrest. |
| Growth Potential | Can proliferate, sprout new channels, and expand when triggered by trauma, puberty, or surgery. | Cannot grow or proliferate on their own. |
| Surgical Recurrence | Extremely high risk of recurrence if even a fraction of the tissue is left behind. | Minimal risk of recurrence after physical removal or correction. |
| Hemodynamic Danger | Localized pain, swelling, and tissue infiltration. | Severe systemic effects. Causes massive shunting, high-output heart failure, or severe deep vein hypoplasia. |
The Map to a Multi-Disciplinary Team (MDT)
Because a single vascular malformation can simultaneously involve genetic mutations (ISSVA) and severe structural/hemodynamic defects (Hamburg), a single isolated specialist may not be our best resource to safely treat our conditions. Seeking care at a dedicated, high-volume vascular anomalies center is vital.
[1, 2, 3]
A true multi-disciplinary team must include:
- Interventional Radiologists: To map high-flow or low-flow mechanics via angiography and perform precise, minimally invasive sclerotherapy or embolization.
- Hematologists / Oncologists: To manage systemic coagulation risks (like localized intravascular coagulopathy) and prescribe modern, targeted genetic therapies.
[1] - Vascular and Plastic Surgeons: Who utilize the Hamburg model to determine if a lesion can be safely resected without triggering a massive, proliferated recurrence.
[1, 2] - Pathologists & Geneticists: To run specialized immunohistochemical stains (like GLUT1) and next-generation genetic sequencing on tissue samples to pinpoint the exact molecular subtype.
[1, 2]
About those one thousand words. Care4-Rare developed a uniform set of questions that may feel familiar to moms. dad, doctors, and those of us born rare. There are about 103 different classifications in our Vascular Malformations Compendium, each with an overview, each with a deep dives. Our hope is that between these all of us will have what we need to seek the care and treatment we need.
— Best in Health and Life —
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