Sunday, November 4, 2012

The Uterine Artery

Subselective catheterization of the uterine artery can be important in a wide range of applications, from uterine artery embolization (UAE), to embolic treatment of adenomyosis, or for control of postpartum uterine bleeding.

The uterine artery is usually a branch off the internal iliac artery (anterior division), and can be recognized by its characteristic location and its strikingly serpiginous distribution.  It frequently anastomoses with the nearby ipsilateral ovarian artery (which originates more distantly from the aorta, just below the renal arteries (or occasionally from the renal arteries). This anastomosis can become significant in embolization procedures. Occasionally, the ovarian artery may supply a large portion of the uterus, leading to incomplete embolization. Nontarget embolization from the uterine artery to the ovary, leading to premature ovarian failure is also an important consideration.

The arterial anastomoses between the uterine artery and ovarian artery has been shown to be less than 500 microns normally, and use of embolization particles larger than this may help prevent nontarget embolization of the ipislateral ovary.

Selective arteriogram of an enlarged and tortuous left uterine artery.  The artery makes a curve in the left pelvis, around a large fibroid (red arrow). The course of the uterine artery typically includes a hairpin turn where the artery passes through the cardinal ligament at the base of the broad ligament and over the ureter at the level of the cervix to proceed cephalad along the uterine body.

Selective arteriogram of the right uterine artery in preparation for embolization of adenomyosis

This patient is receiving an emergent angiogram for post C-section bleeding.  An internal iliac artery, anterior division angiogram was performed.with 30 degrees of LPO positioning (helping to delineate the internal iliac branches). An enlarged uterine artery is present, along the outside of the enlarged post C-section uterus.

What is a good catheter approach for the uterine artery embolization (or other branches of the internal iliac artery)?  One can approach it ipsilaterally or contralaterally to try to maneuver the catheter into the internal iliac artery orifice, and then subselectively approach the uterine artery.
- catheter:     4Fr Cobra-1 catheter (some have described using up to 6Fr), with coaxial 3Fr microcatheter approach for embolization
- guidewire:  70 degree gold-tip 0.018" glidewire
- injection rate/volume: 3-5 ml/sec, total 6-10 ml
- filming: 8 @ 1 fps, AP and 30 degree oblique
  The microcatheter is advanced into the transverse or horizontal position of the uterine artery several cm beyond the uterine artery origin, distal to cervicovaginal branches.

A flush abdominal aortogram after the embolization procedure is not necessary on a routine basis, but occasionally can reveal significant ovarian artery contributions to a fibroid uterus, and can be pursued if there is suspicion on the subselective uterine artery arteriograms

Waltman loop (ref 4)
To approach the ipsilateral uterine artery, a "Waltman loop" can be used in which the catheter is looped in the distal aorta to approach the ipsilateral internal iliac artery.

Although the uterine artery typically arises as a more proximal branch of the internal iliac, anterior division, there is significant variation in the internal iliac artery distribution.  It can also arise as a trifurcation with the superior and inferior gluteal arteries, or from the inferior gluteal artery.

In 1% of women, the uterine artery anatomy is nonstandard, and in this group, it often originates from the ipsilateral ovarian artery.

1. "Vascular and Interventional Radiology" Valji, K. 2nd ed. (2006).
2. "Diagnostic Angiography" Kadir S. (1986)
3.  Gonsalves, C. "Uterine Artery Embolization for Treatment of Symptomatic Fibroids" Seminars in Interventional Radiology. Vol 25:4 (2008)
4. Worthington-Kirsch RL, Andrews RT, Siskin GP, "II. Uterine fibroid embolization: Technical Aspects" Techniques in Vascular and Interventional Radiology Volume 5, Issue 1, March 2002, Pages 17–34
5. Schirf BE, Vogelzang RL, Chrisman HB. "Complications of Uterine Fibroid Embolization" Seminars in Interventional Radiology. Vol 25:4 (2008).
6. Katz MD, Sugay SB, Walker DK, et al. "Beyond Hemostasis: Spectrum of Gynecologic and Obstetric Indications for Transcatheter Embolization" RadioGraphics. (2012) 32:1713-1731.