QUAD #18: Vascular Rings & Aortic Uncrossing with Dr. Carl Backer

Globalcast MD, along with Cincinnati Children's Hospital, sharing knowledge to improve child health around the globe. Hello, I'm Brittany Levy from Stay Current, and last year, in October 2022, Cincinnati Children's hosted the Quad conference, which included the International Organization for Esophageal Atresia, the Aerodigestive Society conference, the Cincinnati Children's Airway Course, and the Cincinnati Children's Pediatric Dysphagia Course. And today, we're going to review vascular rings with Dr. Carl Backer. First, let's start off with some history of vascular rings. Overall, there are four types of vascular rings. One is a double aortic arch. The second is a right aortic arch with a left ligamentum arteriosum and aberrant left subclavian artery. The third is a right aortic arch with a left ligamentum arteriosum. And the fourth is a left aortic arch with a right-sided descending aorta and a right ligamentum arteriosum. Of note, many surgeons are starting to approach some of these revisions thoracoscopically, specifically, the right arch with aberrant left subclavian and double arches with an atretic left subclavian. Probably most of you know that Robert Gross was the first surgeon, first physician to describe, and he actually coined the phrase vascular ring. Robert Gross was a pathologist, and while as a resident, he saw a case of a child who had died from a vascular ring anomaly from a double aortic arch. And he was pretty sure he knew a surgical fix for this child that could have saved their life. Gross at that time noted as a pathology resident that if that ring had been divided when the child was still alive that it could have relieved the pressure and saved the child. And so his career trajectory changed and he later became a pediatric surgeon at Boston Children's Hospital and performed the first vascular ring division. This is his first case and you can see that he divided the ligamentum and divided the arch, both, he did simple ligatures. that was in 1945. The overall procedure was then duplicated in Chicago for similar double aortic arch anatomy. However, Willis Potts, the chief of surgery in Chicago had a slightly different technique. He also divided a double aortic arch, but you notice that he sutured the stumps of the of the divided arch, which is a safer way to do this and is now the standard of care. Dr. Potts was also the first to describe surgical repair of a pulmonary artery sling in 1954. And now, fast forwarding to 2000s, a classification scheme for vascular rings has been developed by the Society of Thoracic Surgeons. This was a large database project that came out in the year 2000. So double aortic arch, right aortic arch with left ligamentum, innominate artery compression, and then pulmonary artery sling. The age of onset of symptoms varies for each of these pathologies. You can see that for the double aortic arch, these children presented quite early within the first month of life. Right aortic arch tend to present later. Pulmonary artery sling, of course, also presented early in life and also the innominate compression syndrome. Most commonly, patients present with stridor or recurrent upper respiratory tract infections. Classically, a barium swallow was used for diagnosis, and Dr. Backer still finds this helpful in marginal cases. But overall, the diagnostic schema has changed. A paper we wrote back in 2005, computed tomography became our method of choice and really replaced the barium swallow. We also strongly recommend a preoperative bronchoscopy often done at the time of the vascular ring division and also a preoperative echocardiogram because probably 10 to 15% of these patients will have a cardiac diagnosis. Commonly for a double aortic arch, the right arch is dominant. A few will have a dominant left arch and only about 5% of arches will be balanced. Repair of this pathology includes a small muscle sparing left anterior lateral thoracotomy. We use the vascular clamps and over sew the stumps and that's what it looks like when we get done. Left dominant arches require a different approach. These patients are operated on through a right thoracotomy and actually are more fun than the left side because when you get done, you can see how widely separated the two stumps are and then in between you can see the trachea here and the esophagus down here. When considering approaches for a pulmonary artery sling, the strategy has changed over time. Originally, Dr. Potts performed this operation through a right thoracotomy. I can't think of a more difficult approach than through a right thoracotomy, but uh Potts used his ductus clamps to uh divide the left pulmonary artery and then he reimplanted it into the same location. Now, these cases are mostly completed through median sternotomy and with cardiopulmonary bypass. Bronchoscopy can help with the workout. This little video shows the patient with the pulmonary artery sling and you can see the left pulmonary artery pulsating here just above the carina, quite an impressive little video. The pulmonary arteries are typically smaller than normal because they've been compressed in utero. You can also see that the location of implantation is different than where the pulmonary artery was transected when it was moved. Now let's get on to those patients with a right aortic arch. This can sometimes be seen on chest x-ray. And if you look at this image, you can see the patient's right aortic arch right here. These right sided arches can be associated with a corales diverticulum. In fact, some require reoperation when only a simple ligamentum division has been performed. We wrote a papers back in about having to reoperate on patients who had a simple ligamentum division and then later had recurrence of symptoms and had a large corales diverticulum is the cause of those symptoms. So the idea is to take out the diverticulum. And then part of that operation is to transfer the left subclavian artery to the left carotid artery. That allows the space around the esophagus and trachea to be widely open without compression. And many of these cases you need to do a primary resection of the corales diverticulum. This little video is a patient with a right aortic arch, arales diverticulum. This is the bronchoscopy of that patient showing the right sided compression. During the operation, it's important to get around the ligaments and divide it, separate the stumps and clip the base of the diverticulum. Clip the subclavian and divide the subclavian. Here's resecting the base of the corales diverticulum. We over sew the base, cut the diverticulum out and now you can see the esophagus pretty clearly. The subclavian artery also gets anastomosis to the carotid artery to make space. Now you can see that area is wide open, no possibility of compression externally. More recently, fetal diagnosis has become a game changer for vascular ring management and operative timelines, especially as more and more patients are being seen by surgeons before they are even born. What we found in our series was that the median age at vascular ring repair dropped from 24 months to 13 months if there was a prenatal diagnosis. And the mean weight at the time of surgery dropped from almost 20 kilos to about 10 kilos. These babies did really well. And actually, those who had a fetal diagnosis had fewer respiratory tract infections. We were operating on them sooner before they got sick. And there was no difference in post-operative complications and really no difference in uh length of stay. Actually the length of stay on the fetal patients was shorter than the other patients. In summary, diagnosis of vascular ring requires a high index of suspicion and workup often consists of a chest x-ray, bronchoscopy, CT scan, and an echocardiogram. The procedure for each vascular ring anomaly has been adjusted over time, but the goal is to remove compression on the trachea and esophagus. In patients with a fetal diagnosis, their time to intervention is expedited without worse outcomes. Hopefully we here at Cincinnati will continue to be at the forefront of efforts to optimize the care of these patients. Thank you for watching this video. Don't forget to subscribe to the Stay Current MD YouTube channel. Follow our social media channels and download the Stay Current MD app for tons of content in pediatric surgery. Globalcast MD, along with Cincinnati Children's Hospital, sharing knowledge to improve child health around the globe.