Back in March, I promised to share the results of my review of 2016 – so many new patients, how many fistulas, how many grafts, so on and so on. I create fistulas, place grafts, do procedures to force fistulas to mature, do a lot of maintenance thrombectomies and venoplasties, stent placements, management of central stenosis, and operative revisions.
"Aneurysms and pseudoaneurysms", images #1 and 2
An aneurysm in a fistula is simply a dilation of the vessel (bottom image) – we expect them to grow, and we don’t always know how to tell them to stop. Sometimes they are hazardous, sometimes not (see my June 5th post).
Pseudoaneurysms are a different beast (top image) – they represent rupture of the access, and there is freqeuntly not much more than subcutaneous tissue and skin to keep the blood in the body. Consequently, the risk of bleeding complcoations is higher.
"Aneurysms and pseudoaneurysms", image #3
This aneurysmal fistula is dilated and a bit scarred, but not hazardous. The fistula is soft, the skin is intact, and the size is stable. The aneurysmal areas can be cannulated, though not carelessly. If pulsatile, a fistulogram and venoplasty would be recommended. If not, no intervention would be indicated unless there was a clincial or performance concern (see “the warning signs” in drmarcwebb.com, “Appointment forms”.
"Aneurysms and pseudoaneurysms", image #4
This pseudoaneurysm appeared suddenly, is tender, and the skin is thinning, shiny, and at risk for rupture. These generally mandate intervention, consisting nof a fistulogram to detect and treat ouflow stenoses, lowering the intraaccess pressure in the process, and a repair component, which could be an endovascular covered stent placement to exclude the leak, or an open resection and replacement.
There is a lot to talk about, but the revisions (144 in 2016) seem to be the most interesting:
- 46 – second-stage superficializations (plus 9 one-stage)
- 18 – second-stage transpositions (plus 36 one-stage)
- 29 – aneurysmoplasties
- 10 – replacement or interposition repair of grafts
- 17 – proximalizations for steal
- 7 – distalizations for steal
- 9 – Pseudoaneurysm resection or repair
- 5 – aneurysm resection and repair
I started out with an example of an aneurysmoplasty, so I will continue in that vein (no pun intended) for a while.
To understand the problems of “aneurysms” it is important to understand that there is a difference between aneurysms (image #1 bottom) and pseudoaneurysms (image #2 top). Fistulas are veins attached to arteries and we WANT them to grow. If we are lucky, they grow just enough to be useful, and then they stop. Frequently, they just keep growing, and when they get big enough we call them “aneurysms”. Image #3 is an example of aneurysmal changes. Sometimes these big aneurysms are problematic, sometimes not (see the June 5th post).
Pseudoaneurysms, on the other hand, are not manifestations of too much growth, but represent rupture of a graft or fistula, and are much more frequently dangerous (image#4). They are frequently painful, prone to rupture, often thrombosed, and can become infected. Most often, an operative approach is needed.
Next post:”Distinguishing between ‘good’ aneurysms, and ‘bad’ aneurysms – five signs’