UPMC Heart and Vascular Insights: Managing Thoracic Aortic Dissections

The UPMC Heart and Vascular Institute has one of the country’s largest and most experienced programs for treating and studying thoracic aortic dissections (TAD). During the last fifteen years, UPMC has treated more than 1,200 cases of TAD and is one of the leading research centers in the U.S. studying the pathophysiology of the disorder while also publishing on its institutional outcomes, notably on the role malperfusion syndrome plays in TAD and how to optimally manage patient care.

In this article, Ibrahim Sultan, MD, FACS, FACC, discusses some of the insights, treatment approaches, and research learnings from UPMC in caring for patients with TAD. Dr. Sultan is the Professor and Chief of the Division of Cardiac Surgery, executive vice chair of the Department of Cardiothoracic Surgery, and co-director of the UPMC Heart and Vascular Institute. Dr. Sultan also is the surgical director of the UPMC Center for Heart Valve Disease, and the cardiac surgery director for the newly formed UPMC Center for Aortic Disease.

A Brief Introduction to Thoracic Aortic Dissections

Thoracic aortic dissections (TAD) are rare yet serious, life-threatening cardiac conditions. The incidence of TAD in the general population is approximately 1 to 2 out of every 10,000 individuals. There are two main types of TAD. Type A dissections involve the ascending aorta or proximal aortic arch. Type B dissections occur in the descending aorta.

A TAD can occur in anyone, but the condition is more prevalent in men and in individuals with certain underlying connective tissue disorders like Marfan syndrome, Ehlers-Danlos syndrome, those with existing aneurysms, and in some individuals who have had prior heart surgeries. Symptoms of TAD are often acute and distinct, including sudden, severe pain in the chest, back, or abdomen. In some individuals experiencing a TAD, symptoms may mimic a stroke or heart attack or involve the loss of circulation to extremities.

Management of the TAD patient is partly driven by the type of dissection the patient is experiencing and other accompanying or mitigating circumstances, such as malperfusion syndrome.

“Our approach is continuously geared towards improving our outcomes while utilizing less invasive surgical techniques, such as stents or hybrid techniques. We place a strong emphasis on employing strategies that reduce patient trauma and expedite recovery. This focus on outstanding clinical outcomes is a fundamental aspect of our treatment philosophy,” says Dr. Sultan.

At Times, a Diagnostic Challenge or Overlooked Option

Thoracic aortic dissections can be challenging to diagnose in emergency settings due to their rarity and how symptoms present in the patient.

"More common conditions like heart attacks or pulmonary embolisms are often considered first when a patient is undergoing diagnosis," says Dr. Sultan. "That makes sense, given how rare the condition is and how symptoms of TAD can often overlap with other conditions. However, when TAD is identified, time is of the utmost essence. Type A TAD are critical emergencies and require immediate surgical intervention.”

UPMC Surgical Protocols and Team Expertise

At the UPMC Heart and Vascular Institute, patients identified with Type A dissections are fast-tracked and admitted directly to the operating room for urgent treatment.

“This approach bypasses the usual emergency room or ICU protocols,” explains Dr. Sultan. “We have developed a sophisticated protocol and have specialized teams comprising surgeons, anesthesiologists, nurses, and perfusionists who are prepared to perform emergency surgery immediately, any day or time of the week, at any time during the year.”

This focused approach has led to significant advancements in treatment methods in addition to direct OR admission, including central cannulation for cardiopulmonary bypass, aggressive surgical techniques for the aortic root and aortic arch, and hybrid approaches combining stents and surgery.

Treatment options for patients with Type B dissections depend on the unique circumstances of the case. At times, rapid intervention with endovascular repair, stabilization approaches, or stenting is employed.

“Through our experience, we have developed a decision tree algorithm for these cases that allows for rapid decision-making of treatments tailored to the patient's specific condition,” says Dr. Sultan. “A big part of the equation in these instances is if the patient has malperfusion or other significant risk factors.”

Even with surgical intervention, acute type A aortic dissection accompanied by malperfusion has an approximate 20% risk of mortality. That’s why the UPMC Heart and Vascular Institute places such a large emphasis on managing and studying malperfusion in TAD.

A Critical Focus on Malperfusion Syndrome

Malperfusion, a high-risk feature of TAD, occurs when the dissection creates an alternate pathway or false lumen in the aortic wall. This formation leads to a pathological diversion of blood flow, which can significantly impede or obstruct perfusion to essential vascular beds supplying the brain, heart, gut, or limbs. This malperfusion can lead to ischemic injury in these downstream organs and tissues.

As Dr. Sultan explains, if the malperfusion extends into the coronary arteries, it can induce myocardial ischemia, mimicking or directly causing a heart attack due to reduced perfusion of the heart muscle. Cerebral malperfusion arises when arteries supplying the brain are involved, potentially manifesting symptoms akin to a stroke. Similarly, peripheral malperfusion occurs when limb arteries are affected, leading to symptoms like a cold or painful extremity.

“From our experience and research at UPMC, we understand that the presence of malperfusion in TAD significantly escalates the urgency and complexity of the situation,” says Dr. Sultan. “This is because it not only intensifies the immediate risks posed by the aortic dissection itself but also heightens the likelihood of long-term organ damage or failure. Prompt identification and appropriate management of malperfusion are vital. Our approach involves a combination of surgical and medical interventions aimed at restoring normal blood flow and safeguarding against further organ damage.”

Recent Study Highlights Importance of Malperfusion in Mortality/Survival

Dr. Sultan explains the critical nature of addressing malperfusion in TAD due to its influence on patient mortality and survival.

One of Dr. Sultan and colleagues most recent papers on the subject, published in the Journal of Thoracic and Cardiovascular Surgery titled “Outcomes of Emergency Surgery for Acute Type A Aortic Dissection Complicated by Malperfusion Syndrome,” assessed how malperfusion syndrome affects survival rates after emergency aortic arch reconstruction for acute type A aortic dissection.

Among 467 patients, those with malperfusion syndrome had a higher in-hospital mortality rate (21.5% compared to 5.7%) and worse overall survival. The risk of death increased with the number of affected vascular beds, and patients with coronary or neuro-malperfusion syndromes were at particularly high risk.

“Our study suggests that immediate surgical intervention to restore proper blood flow might improve outcomes for patients with malperfusion syndrome,” says Dr. Sultan.

Hypothermia in Surgical Treatment

An important aspect of surgical treatment for Type A aortic dissections is the appropriate use of hypothermia.

Dr. Sultan notes that cooling the patients suppresses the body's overall metabolic activity, which can have a protective effect on highly perfused organs like the brain and kidneys.

“This is especially important because frequently when we use circulatory arrest as an adjunct to help reconstruct the aortic arch, this halts the blood supply temporarily to vital organs such as the kidneys," says Dr. Sultan. "Inducing a hypothermic state by using cerebral perfusion while we reconstruct the patient’s aortic arch can lead to significant improvement in outcomes, particularly in reducing the risk of stroke and other morbidities like injury to the kidneys.”

Focus on Specialization and Preventive Care

UPMC boasts a dedicated team of surgeons specializing in thoracic aortic dissections. This specialization has led to the development of advanced treatment methods and improved patient outcomes.

The UPMC Heart and Vascular Institute also emphasizes the importance of preventive care for patients with thoracic aortic aneurysms and connective tissue disorders, as timely intervention can significantly reduce the risk of dissections. This approach leans towards minimally invasive methods, prioritizing patient recovery and long-term health.

“Our overall approach to managing thoracic aortic dissections is driven by our commitment to specialized care and innovative treatment methods for handling complex aortic conditions with effective and patient-centric solutions,” says Dr. Sultan.

Learn More

Visit our website to learn more about UPMC’s aortic dissection clinical care. To refer a patient for consultation, please contact AorticCenter@UPMC.edu.

Further Reading

Below is a small selection of recent papers from Dr. Sultan and colleagues at the UPMC Heart and Vascular Institute on their aortic dissection clinical outcomes and research.

• Brown JA, Aranda-Michel E, Navid F, Serna-Gallegos D, Thoma F, Sultan I Outcomes Of Emergency Surgery For Acute Type A Aortic Dissection Complicated By Malperfusion Syndrome. J Thorac Cardiovasc Surg. 2022 Jul 14; S0022-5223(22)00724-3.

   

• Sultan I, Aranda-Michel E, Bianco V, Kilic A, Habertheuer A, Brown JA, Navid F, Gleason TG. Outcomes of Carotid Artery Replacement With Total Arch Reconstruction for Type A Aortic Dissection. Ann Thorac Surg. 2021 Oct; 112(4): 1235-1242.

   

• Grimm JC, Sultan I. When It Comes to Type A Aortic Dissection: It's All About Malperfusion, Malperfusion, Malperfusion. Ann Thorac Surg. 2021 Jan; 111(1): 60-61. (Invited Commentary)

   

• Sultan I, Bianco V, Patel HJ, et al. Surgery for Type A Aortic Dissection in Patients With Cerebral Malperfusion: Results From the International Registry of Acute Aortic Dissection. J Thorac Cardiovasc Surg. 2021; 161(5): P1713-P1720.

   

• Hasan I, Brown JA, Serna-Gallegos D, et al. Lower-Extremity Malperfusion Syndrome in Patients Undergoing Proximal Aortic Surgery for Acute Type A Aortic Dissection. J Thorac Cardiovasc Surg. 2023. 15: P1-P13.