Dr Jason Toniolo

Pelvic Venous Congestion Syndrome

Pelvic venous congestion syndrome occurs when veins in the pelvis become engorged and do not drain properly.

It can severely affect someone’s quality of life. It can be challenging to diagnose, as there are lots of people who have varicose veins in their pelvis who have no symptoms; similarly, some patients have debilitating symptoms.

 

Symptoms

There is a long list of symptoms, which vary from patient to patient. It is worth noting how many of these symptoms can be caused by other conditions.

  • Lower back pain
  • Chronic pelvic pain, vaginal pain, groin pain, hip pain – typically relieved by lying down and worse when standing up
  • Swollen left leg +/- left leg varicose veins, particularly preferencing the back of the thigh and buttocks
  • Pain during or after intercourse
  • Urinary urgency, frequency or painful urination
  • Heavy and painful periods
  • Pain with ovulation
  • Other more vague and rare symptoms: Swollen vulva, lumbosacral neuropathy (inner thigh and calf burning pain)

Heavy or painful periods or pelvic pain can also be caused by adenomyosis, endometriosis, ovarian cysts, pelvic inflammatory disease, uterine fibroids

Lower back pain and leg pain have a long list of musculoskeletal causes. It could be a muscular injury, ligamentous injury, a bony injury, a protruding disc and many more causes.

Urinary frequency and painful urination can also be caused commonly in women by urinary tract infections.

Other conditions that can cause pelvic pain:

  • Bowel pathology
  • Neurological pathology
  • Uterine prolapse
  • Urogenital pathology

 

Key message for patients to understand

The key critical concept from reading this article is that many women develop congested pelvic veins and do not have symptoms. Those with symptoms may think the pain is from their veins, but it could be one or multiple other conditions. The safest approach is to rule out all other causes. Intervention on pelvic varicose veins is reserved for patients with severe symptoms when no other cause can be found, provided the symptoms are severe enough to necessitate surgery.

 

Causes of pelvic congestion syndrome

 

Hormonal

Result of pregnancy and associated hormones – The most common presenting age group would be pre-menopausal women after they have given birth. Hormones related to pregnancy relax the veins, combined with the increased blood volume and pressure of the gravid uterus, which can overwhelm and dilate the pelvic veins, causing the valve leaflets to no longer function as intended. They are unable to restore their function after the blood volume, hormones, and uterus return to normal, leaving the pelvis in a state of permanent venous hypertension. Women who have had multiple children tend to have the highest incidence of pelvic congestion syndrome.

 

Compression

Result of compression of a central outflow vein higher up: Imagine the Princess motorway has had a traffic accident, and cars are backed up for kilometres. The vehicles (blood cells) cannot quickly get to Sydney from Wollongong. Instead, they have to take inland roads and side streets, which quickly get overwhelmed, as the smaller roads can’t cope with the volume of traffic that typically drives from Wollongong to Sydney. When a central vein gets compressed or squashed, something similar happens. The blood can’t pass through the narrowing properly. Hence, the pressure below the compression increases significantly and directs blood through other outflow channels (other smaller veins that eventually lead to the heart but aren’t used to coping with such a large amount of blood). 

Overall, this leads to the three causes of pelvic congestion. Two are compression-related, and one is related to changes in pelvic drainage after pregnancy.

 

Left common iliac vein compression syndrome

Known medically as May-Thurner syndrome. The common iliac vein (main vein that drains the leg and pelvis gets squashed between an artery of the leg and the vertebral column. If this is present, it is something you are born with that can take years to reveal itself as a problem.

 

Left renal vein compression syndrome

Also known as Nut-Cracker syndrome, the vein gets squashed between the large artery of the abdomen and the large artery to the intestines

 

Gonadal (ovarian or testicular) vein incompetence

The third cause of pelvic congestion syndrome is a poorly functioning gonadal vein – ovarian vein in women and testicular vein in men. If there is a compressive issue, such as May-Thurner syndrome or Nut-Cracker syndrome, the left ovarian or testicular vein can become engorged. It then eventually become varicose and result in a back-log of pressure in the pelvis and e a cause of pelvic congestion syndrome.   Sometimes, women after pregnancy can have an incompetent ovarian vein without any compressive lesion, and the hormones, large pregnant uterus and increased blood volume from pregnancy are enough to damage the ovarian vein, leading to its issues post-delivery.

treatment options

The first thing that must be done is to ensure the diagnosis is accurate. Before a diagnosis of pelvic congestion syndrome can be made, a gynaecologist should be involved in exploring all other potential causes. Of all patients who present with pelvic pain to gynaecologists, studies estimate that between 13-30% are due to pelvic congestion syndrome (O’Brien 2014)

When the decision to perform a vascular intervention is made for pelvic congestion syndrome, the treatment is focused on where the most significant culprit lesion exists.

Left common iliac vein stent

Patients with a tight left common iliac vein compression (May-Thurner) and severe symptoms are offered a left common iliac vein stent. This procedure takes 45 minutes and involves intra-vascular ultrasound to confirm the exact point of compression and appropriate location for stent placement, as well as the diameter of the left common iliac vein to help size the stent. The procedure can be performed under local anaesthetic, but general anaesthesia is often preferred, as breaking the webs within the vein with a large balloon can be very uncomfortable.

The risks of the procedure itself are minimal. However, the risks associated with stent complications in the following years are not to be underestimated. They occur infrequently but are serious when they do. Things that can go wrong in the days to years that follow stent insertion include:

  1. The stent moving outside of the vein to another location, typically the heart of the lungs – this is a problem that is hard to fix
  2. The stent can become blocked, causing a large clot in the left leg and worsening pelvic and leg symptoms. The blockage can happen suddenly or gradually. Patients are put on an ultrasound surveillance protocol to ensure the stent isn’t narrowing in the subsequent years, which can occur as some people form scar tissue over the stent that continues to narrow the stent
  3. The stent often has to sit proudly in the inferior vena cava. The metal struts can complicate flow from the right leg and cause clots in the right leg – again, very uncommon.

 

Left renal vein transposition

This procedure is done for nut-cracker syndrome and is very infrequently performed. It involves moving the left renal vein inferiorly and re-attaching it to the inferior vena cava. This is a large, invasive operation and should be discussed in person, at length, after further testing using pressure gradients and venography in a hospital.

Ovarian vein embolisation

This procedure is reserved for patients with pelvic congestion and symptoms who do not have a compression of their left common iliac vein or renal vein. It involves a day surgery procedure in which a small needle is inserted into the vein in the groin, and the ovarian vein is accessed using wires and X-ray machines to guide the wires to the ovarian vein. A combination of sclerosant (medicine that kills veins) and coils (a series of metal fibres that look like a slinky) are inserted into the length of the incompetent ovarian vein to block it forever.

There are risks of this intervention, which include:

  • Temporary pain and fever following blockage of the ovarian vein
  • Recurrence of unhealthy, incompetent varicose veins in 1 out of 10 patients
  • Migration of coils to the lungs, which happens in <2% of patients and, whilst frightening to think of, usually does not cause any symptoms or problems.
  • Fertility is not affected by this intervention. There is some evidence to suggest it improves semen count in men who are having the intervention done to treat a varicocele, as it reduces the temperature in the testicle and removes the venous hypertension within the testicle).

 

Success of embolisation

Patients who undergo ovarian vein embolisation and who do not have a concurrent compressive syndrome typically have a resolution of their pelvic pain in 47 to 94% of cases (O’BrO’Brien5). The wide variance in success rates is likely attributable to the importance of making the correct, which is achieved by ruling out other causes of pelvic pain mentioned above. Whilst both ovarian veins can be incompetent, there is a lack of data to support any improvements in pain scores embolising both ovarian veins when compared to only embolising the left ovarian vein. There may be improvements in labial varicosities or varicoceles in men by embolising both gonadal veins if this is the main presenting issue.