Vascular Rings

All's right with the world… 

… The twisted sisters are back together again.

And thank goodness. Both Meredith and Cristina could use some friendship and comfort after the last couple of days they've had. Meredith performed a field rescue and never left a patient's bedside in order to save her life… and happened to mourn the death of her sister at the same time. And Cristina? Not only did she participate in two extremely difficult surgeries to repair a patient's aneurysm and unusual anatomy… But she lost the only friend she had in Minnesota.

Yep. Good thing they're back together again.

Cristina's patient Katy was born with a "vascular ring." Which is what, we all ask?

Relatively rare, a vascular ring is a type of congenital defect that can be defined by an atypical formation of the aorta and its surrounding blood vessels. In normal circumstances, during fetal development, the aorta comes from one of several symmetrical arches. After two months, the other arches will break down or become arteries. However, in patients like Katy, certain arches never disappear and instead form a ring-like structure.

Several types of vascular rings exist, but Katy suffered from a: Double Aortic Arch.

In this variation, the aorta begins at the heart as one normal vessel, but then continues to divide into two separate arches – one on each side of the esophagus and trachea. The two arches then return back together as one vessel, which ends up as the descending aorta.

Another common type is a: Right Aortic Arch With Left Ligamentum Arteriosum. In this construction, the aorta abnormally starts off to the right and forms a branch that goes behind the esophagus. Two vessels, the subclavian artery and the ligamentum arteriosum (a remnant of a vessel that normally only occurs during fetal development), come off the abnormal aorta and complete the ring.

Is the formation of an aneurysm part of the process of having one of these rings?

Aneurysms are not necessarily a part of having a complete ring, but they can be a complication of the disease because of the weakness of the vessels. Symptoms include:

• Noisy breathing, cough, wheezing.
• Respiratory distress or infections.
• Difficulty feeding as an infant.
• Swallowing difficulties.
• Gastroesophageal reflux.

Why didn't Katy know she had it when she was little?

Depending on the severity of the vascular ring, some cases are not diagnosed until adulthood. However, if one starts to experience respiratory or digestive symptoms, they most likely will undergo an extensive work-up. After conducting a physical exam, the doctors can confirm a diagnosis by one or a combination of the following tests: a chest X-ray, chest CT, cardiac MRI, echocardiogram, bronchoscopy, and gastrointestinal tests such as a barium swallow.

Do all patients with vascular rings need surgical treatment?

If a patient is symptomatic or develops a complication (like in Katy's case with her large aneurysm), surgery to divide the ring is almost always indicated. The operative goal is to open the closed ring with acceptance that many of the vessels may still have an abnormal course. But as long as one part of the ring now is open, the trachea and esophagus will no longer be constricted, providing relief to many of the symptoms.

Typically, surgeons perform the procedure by making an incision on the left side of the chest, entering between the ribs. For patients with a double aortic arch, the left side or smaller side of the ring is divided, reducing the compression of the esophagus. For patients with a right aortic arch and left ligamentum arteriosum, surgeons create the division between the descending aorta and pulmonary artery.

So what happened in Katy's surgery? When Cristina and Dr. Thomas were trying to re-route her blood vessels in order to bypass the aneurysm, it ruptured due to the weakness and friability of the vessels. But despite this complication, surgeries for complete rings remain relatively low in risk.

For additional information on vascular rings, please visit the following link:

http://www.nlm.nih.gov/medlineplus/ency/article/007318.htm