Introduction
Aortic dissection in children and adolescents is a highly rare disease (fewer than 30 cases <25 years old in the literature). Reference Zalzstein, Hamilton and Zucker1 For young patients, hereditary factors are an important cause of the disease. When thoracic aortic aneurysms and dissections appear to be familial, clinicians tend to describe them as syndromic or nonsyndromic based on the presence or absence of external phenotypes related to connective tissue disorders. Reference Chou and Lindsay2 The key syndromes to consider in any patient who presents with an aortic aneurysm at a young age include familial thoracic aortic aneurysm and dissection, Marfan syndrome, and Loeys-Dietz syndrome. The reported mutations related to thoracic aortic aneurysm and dissection include the fibrillin 1 gene, the transforming growth factor beta receptor genes 1 and 2, the myosin heavy chain protein 11 gene, the α-actin, et al., among which myosin heavy chain protein 11 gene mutations are responsible for approximately 2% of familial thoracic aortic aneurysm and dissection. Reference Krywanczyk, Rodriguez and Tan3,Reference Takeda and Komuro4 Additionally, mutations in the fibrillin 1 gene account for approximately 70–93% of patients who meet diagnostic criteria for Marfan syndrome, and Loeys-Dietz syndrome is associated with mutations of transforming growth factor beta receptor genes 1 and 2, which are also responsible for thoracic aortic aneurysm and dissection. Reference Cury, Zeidan and Lobato5
The management of aortic dissection in adults depends on the type of the disease. For type A aortic dissection, which affects the ascending aorta, surgical repair with artificial grafts as quickly as possible is recommended. For type B aortic dissection affecting the descending aorta, the best medical treatment and elective endovascular therapy are generally applied, among which the patients with complications or high-risk factors are recommended to receive endovascular intervention. However, for the treatment of complicated or high-risk type B aortic dissection in young patients, it is quite challenging and inconclusive which method of treatment has better outcomes. The surgical treatment remains a huge trauma, especially for the children, and the transplanted graft would not prolong during the children’s growth and development. Thoracic endovascular aortic repair has been the first-line choice for complicated or high-risk type B aortic dissection in adults, but it’s results in children and adolescents remain unclear because there has been only one case report with the three weeks’ results of endovascular treatment of an 11-year-old patient. Reference Kazimierczak, Rynio and Gutowski6
Here, we report a case of a 15-year-old high-risk type B aortic dissection patient receiving endovascular therapy and the results of 4 years’ postoperative follow-up.
Case report
A 15-year-old girl complained of abrupt thoracic and upper abdominal pain and vomiting. A final diagnosis of type B aortic dissection was established with the aid of computed tomography angiography. As shown in Figure 1, the primary entry tear is located on the lesser curvature near the left subclavian artery, and the dissection originated from the descending aorta to the abdominal aorta, accompanied by 80% narrowing of the true lumen. The coeliac trunk, superial mesenteric artery, and left renal arteries were supplied by the true lumen, and the right renal artery was from the false lumen. No history of heart disease or any injury was reported. Her upper abdominal pain recovered quickly after diagnosis. The blood pressure, hepatic function, renal function, and bowel movements were all normal. Relevant inspections showed a good crystalline lens and a normal cardiac function and aortic valve. The rheumatology consultation concluded that there was insufficient evidence for connective tissue disease and Marfan syndrome was not a priority diagnosis. In her family, her grandmother died suddenly with unclear causes when she was young, and her mother died from cardiac and cerebrovascular accidents also at a very young age (details were unavailable). The health conditions of the other members of her immediate family were normal. Genetic testing of the patient suggested mutations in myosin heavy chain protein 11 genes. Though the diagnosis of the mother and grandmother of the patient could not be confirmed, familial thoracic aortic aneurysm and dissection were suspected for this patient. Symptomatic treatment such as pain medication and heart rate control to 60–70/min (metoprolol sustained-release tablets, 47.5 mg/day) was applied for two weeks, but she still complained of recurrent thoracic pain. Repeated computed tomography angiography showed the aortic dissection false lumen apparently expanded with the thrombus decreased and the total diameter of the thoracic aorta enlarged from 2.9 to 3.5 cm in one week (Figure 2).
Type B aortic dissection: ( a ) primary tear located on the lesser curvature; ( b ) the true lumen was severely compressed by the false lumen; ( c ) the superial mesenteric artery was from the true lumen; ( d ) the right renal artery was from the false lumen, and the left renal artery was from the true lumen; ( e ) partial thrombosis of the false lumen; ( f ) three-dimensional reconstruction of the whole aorta.
Figure 1 Long description
A CT scan showing a type B aortic dissection. The primary tear is located on the lesser curvature of the aorta. The true lumen is severely compressed by the false lumen. The superior mesenteric artery originates from the true lumen, while the right renal artery originates from the false lumen, and the left renal artery originates from the true lumen. There is partial thrombosis of the false lumen. Additionally, a three-dimensional reconstruction of the whole aorta is presented.
Serial CT scans showed that the false lumen increased and the whole thoracic aorta was dilated (b1, b2, b3) compared to the CT images one week before (a1, a2, a3).
Figure 2 Long description
The image displays a series of CT scans comparing the thoracic aorta at two different time points. The first set of images (a1, a2, a3) shows the initial state of the aorta, while the second set (b1, b2, b3) illustrates the progression of the condition. The false lumen in the aorta has increased in size, and the entire thoracic aorta appears dilated in the later scans compared to the earlier ones. The images highlight the changes in the aortic structure over a week.
Due to the recurrent thoracic pain and rapid expanding of the dissecting aneurysm, we recommend intervention for the patient. Both the legal guardian and the patient herself refused open surgery and preferred endovascular treatment. We carefully obtained the informed consent from her legal guardian before performing thoracic endovascular aortic repair. Three weeks after the onset of the disease, in the subacute phase of the high-risk type B aortic dissection, the patient underwent thoracic endovascular aortic repair. Due to the small size of the thoracic aorta and the severely compressed true lumen, a C3 iliac stent-graft (W.L. Gore & Associates, Flagstaff, AZ, USA, 16 mm in proximal and distal size and 95 mm in length) was first deployed in zone 4 and proximal zone 5 (distal landing T8) as a restrictive stent. After that, an Ankura thoracic stent-graft (Life-tech, Shenzhen, China, 20 mm in proximal and distal size and 80 mm in length) was released proximally in zone 3 and distally, overlapping the first stent. Due to the low profile of the two stent grafts (12F and 16F), they were successfully delivered through percutaneous femoral access with the Abbott ProGlide closure device.
The strategy for spinal cord protection in this case included limited coverage of the aorta (total length of coverage was 12 cm), maintaining patency of the left subclavian artery, elevated blood pressure after deployment of the covered stents (mean arterial pressure > 90 mmHg), stable haemoglobin level (Hg > 10–12mg/dL), and temperature management (mild hypothermia, without active warming devices). A preventive spinal drain was not placed, and adjunctive medications like mannitol, naloxone, or corticosteroids were not used. After stenting, the angiography showed an expanded true lumen of the thoracic and abdominal aorta and good blood flow in the left subclavian artery and visceral branches. These stent grafts completely covered the primary tear of the dissection, and there was no type IA endoleak. Additional balloon modification or uncovered dissection stents were not used. The patient awakened from anaesthesia quickly, and there wasn’t any sign of paraplegia. She recovered smoothly after the endovascular repair and was discharged one week later without any symptoms.
The postoperative one-month and one-year follow-up computed tomography angiographies showed good blood flow in the stents and the thoracic and abdominal true lumen (Supplementary 1 A1-B1-C1, A2-B2-C2). The false lumen in the stented thoracic aorta gained a good remodelling with total absorption. The false lumen was partially thrombosed in the distal thoracic aorta and was still patent in the abdominal aorta due to some distal re-entry tears in the abdominal part. The femoral access site was patent. Her most recent follow-up visit was four years after the interventional treatment, and the repeated computed tomography angiography showed a similarly good remodelling of the thoracic aorta but a gradually expanded false lumen of the abdominal aorta (Supplementary 1 A3-B3-C3). She has no chest tightness or pain and no significant discomfort after daily activities.
Discussion
Clinical epidemiology suggests that aortic dissection is more often associated with sex, age, and hypertension. Most of the patients are middle-aged men with a history of hypertension. On the contrary, the girl in the current report is so young without hypertension. Furthermore, she has a suspicious family history, as her mother and grandmother died suddenly at a young age. Those suggest that her aortic dissection may have a genetic factor, which is confirmed by her genetic test showing there were mutations in the myosin heavy chain protein 11 gene. The gene encodes the smooth muscle cell-specific myosin heavy chain, a major component of the contractile unit in smooth muscle cells. Recent observations indicate that relative upregulation or downregulation is less important for disease than disruption of proper contractile protein homeostasis. Reference Isselbacher, Lino Cardenas and Lindsay7 Pannu et al. reported a familial case with thoracic aortic aneurysm and dissection/patent ductus arteriosus and two missense variants, L1264P (3791T4C) and R1275L (3824G4T), of the myosin heavy chain protein 11 (NM_002474.2; NP_002465.1) gene, which are on the same allele judged by co-segregation across generational lines. Reference Pannu, Tran-Fadulu and Papke8 In the current case, there were also mutations in the myosin heavy chain protein 11 (NM_002474) gene but not in L1264P, which also resulted in type B aortic dissection.
The treatment of type B aortic dissection is still controversial, especially for uncomplicated dissections. Moulakakis et al. reported that endovascular repair provided a superior 30-day/in-hospital survival for acute complicated type B aortic dissection compared to surgical aortic reconstruction. Reference Moulakakis, Mylonas and Dalainas9 Nienaber et al. reported that, at two years of follow-up, thoracic endovascular aortic repair did not improve survival or aortic-related events compared with best medical therapy but did facilitate true lumen contouring and complete thrombosis of the false lumen. When follow-up was extended to five years, thoracic endovascular aortic repair improved survival and slowed disease progression. Reference Nienaber, Rousseau and Eggebrecht10 As a result, thoracic endovascular aortic repair seems to have a more favourable outcome regarding aortic remodelling and the aortic-specific survival rate when compared with medical therapy alone in the long run and open surgical repair.
Furthermore, in the current case, there were several risk factors that indicated the more active treatment, except medical therapy. The primary tear located on the lesser curvature and the false lumen expanded apparently in a short time, which are high-risk factors for further prognosis. However, it is quite challenging which intervention would be better for such a young patient with gene mutations. The surgical treatment is a preferred option but remains a huge trauma, and the transplanted graft would not prolong during the children’s growth. Although the stent-graft would not expand in the children’s bodies either, endovascular therapy is more minimally invasive. However, the potential risk of stent-graft-induced new entry exists, and the mid- and long-term results in such young patients are not clear without such reports. The current case received thoracic endovascular aortic repair successfully and recovered smoothly. The four-year follow-up showed that the covered stents were stable, and the stented thoracic aorta gained good remodelling. To the best of our knowledge, so far, there has been only one case in the literature reporting the endovascular repair of type B aortic dissection in an adolescent. Kazimierczak A et al. treated an 11-year-old girl with type B aortic dissection using endovascular therapy but only reported the postoperative three weeks’ follow-up result. Reference Isselbacher, Lino Cardenas and Lindsay7 Our case is the first to report the mid- to long-term result and indicates that thoracic endovascular aortic repair might be a feasible option for young patients in the mid- to long-term perspective. However, the expansion of thoracic endovascular aortic repair for younger patients should be carefully considered, and the longer-term results need to be intensively followed up.
Conclusions
Aortic dissection in children and adolescents is highly rare, and genetic mutation is one of the important pathogenic factors. Early diagnosis is usually difficult because of the rarity of the disease and the atypical manifestation in young patients. Computed tomography angiography is needed to validate the diagnosis, and genetic testing is recommended to explore the underlying pathogenesis. The treatment modality of type B aortic dissection in such young patients is controversial. Our case indicates that thoracic endovascular aortic repair might be a feasible option for complicated or high-risk patients, and the mid- to long-term results are promising. However, the expansion of thoracic endovascular aortic repair for younger patients should be carefully considered, and studies with more patients and longer-term results are needed in the future to explore and confirm the best treatment.
Supplementary material
The supplementary material for this article can be found at https://doi.org/10.1017/S1047951126112025.
Financial support
The study was sponsored by the Major Science and Technology Project in Medical and Health of Zhejiang Province (a co-constructed project by the province and the ministry, WKJ-ZJ-2338) and the Medical and Health Project of the Zhejiang Province (2023KY687).
Competing interests
None.
Ethical standard
This report has been approved by the Clinical Research Ethics Committee of our hospital, and the study has been conducted in accordance with the principles in the Helsinki Declaration. The legal guardian of the patient has given the informed consent for reporting the case and permission for the publication of any potentially identifiable images or data included in this article.
