Thoracic Aortic Dissection (Type B) Managed with Emergency Cesarean Section and Thoracic Endovascular Aortic Repair

Introduction

Aortic dissection is among the most fatal of cardiovascular emergencies. This condition involves progressive tearing in the inner layers of the aorta, allowing blood to flow between the tunica intima and the media. This can result in the occlusion of branches of the aorta, causing ischemia in the corresponding organs and, ultimately, death [1].

The Stanford classification divides aortic dissection into 2 types. Type A aortic dissection involves the ascending aorta, specifically any part of the aorta proximal to the origin of the left subclavian artery. Type B aortic dissection involves the descending aorta and arises distal to the left subclavian artery [2]. The most common risk factors are male sex, age >65 years, hypertension, smoking, aneurysms, congenital disorders, and inflammatory disease [1].

An association between pregnancy and aortic dissection has also been reported [3]. However, pregnancy itself is not a direct cause of aortic dissection. Underlying conditions such as hypertension significantly contribute to its development. The hypothesis has been proposed that the physiological changes occurring during pregnancy, including increased blood volume, cardiac output, and hormonal influences on vascular integrity, may contribute to an elevated risk of aortic dissection, particularly in the third trimester [4]. Moreover, unsuccessful attempts at labor induction and the labor process itself could further exacerbate the dissection, increasing the risk of maternal and fetal mortality, especially if it occurs before delivery [3].

The gaps in understanding prevention, diagnosis, and follow-up for patients at risk for pregnancy-associated aortic dissection remain significant, with notable challenges in clinical recognition and management. Aortic dissection occurring during pregnancy is likely underdiagnosed due to its overlap with other clinical conditions, particular in postpartum cases and after hospital discharge [5]. Pain is the most frequent symptom, typically localized in the chest cavity. Other localizations are back, neck, throat, head, epigastrium, or groin [6]. The prevalence of pregnancy-related pain ranges from 16% to 54%. It typically reaches peak intensity between the 24th and 36th week of pregnancy. Pregnancy-related pain is often not fully understood and may stem from multiple underlying causes. It is not a specific symptom that can directly point to a particular medical condition [7].

Type B aortic dissection tends to be less symptomatic than type A aortic dissection, and symptoms can resemble preeclampsia [2]. Therefore, it is possible to miss the diagnosis, and diagnosis is important to avoid serious complications. The risk of ischemia in viscera, kidneys, spinal cord, or lower extremities due to malperfusion should be considered during treatment. These are complications that are seriously life-threatening [8]. Additionally, mental health outcomes following pregnancy-associated aortic dissection are poorly understood [5].

Thoracic aortic dissection can present as a medical emergency and is often associated with hypertension and connective tissue disorders. This report describes a 28-year-old woman with a history of hypertension, presenting at 37 weeks’ gestation with type B descending thoracic aortic dissection, managed with emergency cesarean section and thoracic endovascular aortic repair (TEVAR).

Case Report

At 37 weeks of gestation with her first pregnancy, a 28-year-old woman was admitted to the gynecological ward of our obstetrics hospital due to severe hypertension. At the beginning of the pregnancy, blood pressure values were within normal limits, with occasional readings reaching up to 140/99 mmHg. However, by the 37th week of pregnancy, blood pressure values escalated, reaching 175/112 mmHg.

She had a history of resistant arterial hypertension, for which she was medicated with 3 antihypertensive drugs. She also had hypothyroidism, bronchial asthma, and obesity (BMI=39 kg/m2). The patient did not have Marfan syndrome or Ehlers-Danlos syndrome.

At 39 weeks of pregnancy, a pre-induction procedure (cervical ripening) was conducted with a Foley catheter. Two attempts at labor induction were unsuccessful. During induction, the patient complained of pain radiating to the left scapula. A cesarean section was performed without complications. Just before the cesarean section, her blood pressure soared to 230/130 mmHg, with a heart rate of 89 bpm. Spinal anesthesia was administered, because the patient did not consent to epidural anesthesia. The newborn had a score of 10/10 on the Apgar scale.

A few hours after the birth, the patient complained about experiencing abdominal pain. X-ray examination revealed fluid levels indicating ileus. An ultrasound of the abdomen also showed the probability of intestinal obstruction. A laparotomy was performed, revealing bowel necrosis extending from the ileum to the transverse colon.

Within the first 24 hours after the cesarean section, the patient was transferred to a multi-specialty tertiary hospital for further examination. The patient was in critical condition, unconscious, hemodynamically unstable, sedated, and intubated. Initial vital signs were as follows: blood pressure of 67/37 mmHg, pulse 67 beats per minute, oxygen saturation 90% on room air. The complete blood count was without important abnormalities. The platelet count was within normal limits (228×103/μL; reference range: 150–400×103/μL). The patient’s laboratory test results showed a significantly low albumin level of 2.1 g/dL (normal range: 3.5–5.3 g/dL). Her amylase level was markedly elevated at 683 U/L (normal range: 28–100 U/L), and lipase was also significantly increased at 1058 U/L (normal range: 13–60 U/L). The creatinine level was elevated, at 3.18 mg/dL (normal range: 0.5–1 mg/dL). Urea was also raised at 79 mg/dL (normal range: 15–48 mg/dL). D-dimer levels were extremely high at >10 000 ng/mL (normal range: 0–500 ng/mL), as were alanine aminotransferase (3067 U/L; reference range: 7–30 U/L) and aspartate aminotransferase (5960 U/L; reference range: 5–40 U/L). Arterial blood gas analysis revealed respiratory acidosis. The pH was measured at 6.899 (normal range: 7.35–7.45), and the pCO2 was 53.8 mmHg (normal range: 35–45 mmHg).

Immediately upon the patient’s arrival at the hospital, urgent chest and abdominal computed tomography (CT) scans with intravenous contrast were performed. The imaging revealed aortic dissection involving both the thoracic and abdominal aorta. However, due to poor resolution and significant air in the abdominal cavity, detailed visualization was not possible.

An emergency relaparotomy was performed. After opening the abdomen, significant ischemia of the duodenum was found. There was complete necrosis of the entire small intestine including the duodenum, as well as complete necrosis of the ascending colon and the right half of the transverse colon, as seen in Figure 1. In addition, the gall bladder was inflamed, the right lobe of the liver was slightly ischemic, and the uterus was significantly enlarged. A decision was made to perform a resection of the small intestine from the horizontal part of the duodenum to the ligament of Treitz and a right extended hemicolectomy as a rescue operation. Then cholecystectomy was performed due to advanced acalculous cholecystitis. The drains placed by the previous surgical team were left in place-the left drain around the closed duodenum; the right drain in the post-cholecystectomy site.

After the operation, the patient remained sedated, intubated, and mechanically ventilated. She was hemodynamically unstable, requiring vasopressor support with adrenaline and noradrenaline, and exhibited oliguria and hypoglycemia. Despite active warming measures, she was in hypothermia. She was transferred to the intensive care unit (ICU) for specialized monitoring and management tailored to her critical condition. Comprehensive care in the ICU included continuous arterial pressure measurement using an arterial line, central venous pressure monitoring, and assessment of cardiac output for hemodynamic stability. Neurological status was regularly assessed to detect potential complications. Respiratory parameters, including oxygenation, arterial blood gases, and end-tidal CO2, were closely monitored. Renal function was evaluated through frequent measurements of urine output and serum creatinine. Continuous temperature monitoring was implemented to manage hypothermia effectively. Coagulation and hematologic parameters, including platelet counts, coagulation profiles, and hematocrit levels, were regularly assessed to address bleeding or thrombotic risks.

Continuous infusion of labetalol was started as a treatment for her hypertension. Several oral medications were then added. As a result of this therapy, satisfactory blood pressure values were achieved at the end of hospitalization. The patient also required hemodialysis, because of acute kidney injury and failure to return to normal secretory function. Hypothyroidism most likely developed as a response to the patient’s underlying condition. The patient remained clinically euthyroid and did not require tyrosine supplementation.

The following day, a bedside transesophageal echocardiogram was performed, showing significant abnormalities including left ventricular hypertrophy and trace mitral and tricuspid regurgitation. The repeated X-rays and CT scans of the abdominal and thoracic aorta revealed dissection before the arterial origin of the subclavian artery through the abdominal aorta, with involvement visible at the level of the common iliac arteries, as seen in Figure 2. The precise diagnosis was a type B dissection of the thoracoabdominal aorta with malperfusion of the superior mesenteric artery. On the same day, a TEVAR was performed. A left inguinal incision was made, and a 20-Fr sheath and a 0.035-inch guidewire were introduced into the left common femoral artery. Angiography was performed; however, certainty regarding presence in the true aortic canal was not obtained. Subsequently, a right axillary puncture was performed, confirming the presence in the true canal (Figure 3). The left subclavian artery and dissection onset were marked. A 0.035-inch guidewire was introduced to facilitate the introduction of the Zenith TX2 Dissection Endovascular Graft with Pro Form Z-Track Plus Introduction System (Cook, Illinois, USA), measuring 199×34 mm. Accurate placement was verified and we proceeded with deployment. Fluoroscopy confirmed the correct placement of the stent graft and widening of the true aortic canal with adequate blood flow (Figure 4). A follow-up CT revealed appropriate coverage of the dissection (Figure 5).

Two days after admission to the hospital, the patient underwent duodenal resection with the formation of biliary, pancreatic, and gastrostomy drainage.

A week later, the procedure of anastomosis of the stomach with the initial section of the small intestine took place. The peritoneal cavity contained a large amount of free fluid with a strong inflammatory reaction in the areas of the pancreas, stomach and the remaining large intestine. The descending colon was dissected. An anastomosis was performed with the pre-pyloric part of the stomach, side-to-side, 2c-layer, manually. Due to the large inflammatory infiltrate, approximately 30 cm of the transverse and descending colon were not prepared. Two drains were inserted in the region of the pancreatic head and 1 drain in the area of the left flank.

During hospitalization, she needed approximately 21 units of blood products for replacement of lost blood. However, she never received 4 units consecutively, so she did not receive plasma.

As she became more aware of her condition, episodes of visual hallucinations, sympathetic hyperactivity, insomnia, mood disturbances, and severe anxiety response began to occur.

The patient, hemodynamically and respiratorily stable, conscious, and with preserved logical-verbal contact and circadian rhythm, was discharged after about 2 months. She retained 25 feet of both small and large intestine following the surgical interventions. The patient was placed under the supervision of general and vascular surgeons, cardiologists, internal medicine specialists, physiotherapists, dietitians, and psychologists. The child had been consistently monitored since birth by a pediatrician, and has shown normal development.

Discussion

INCIDENCE:

Aortic dissection is a rare condition, with an incidence of 5 to 30 cases per 1 million people per year. Aortic dissection is typically suspected in individuals presenting with classic symptoms and possessing well-established risk factors [9].

CAUSES:

Hypertension is the most prevalent risk factor for Stanford type B aortic dissection, occurring in approximately 70% of cases. Sudden and severe increases in blood pressure, such as those induced by strenuous physical exertion or the use of sympathomimetic agents (eg, cocaine, ecstasy, or energy drinks), can further elevate the risk of dissection. Additional risk factors include preexisting aortic aneurysms, atherosclerosis, and a history of aortic instrumentation or surgery, such as coronary artery bypass grafting, valve replacements, or catheter-based interventions. Inflammatory and infectious diseases contributing to vasculitis, including syphilis and chronic cocaine use, may also predispose individuals to aortic dissection [9].

In younger patients, special attention should be directed toward genetic syndromes that predispose to aortic dissection, such as Marfan syndrome, Ehlers-Danlos syndrome, Turner syndrome, and bicuspid aortic valve disease [9,10]. The literature highlights the importance of identifying genetic syndromes in younger patients with aortic dissection. A case series from 2014 demonstrated that 3 out of 4 female patients had a confirmed diagnosis of Marfan syndrome, while the remaining patient had a maternal history of Marfan syndrome, though it was not genetically or clinically confirmed in her case [11]. Other reported cases further support the association between genetic syndromes, such as Marfan syndrome, and an increased risk of aortic dissection in younger patients [12–15].

Aortic dissection in women under 40 years of age is rare, and it is even rarer in pregnant women [6,16]. In the literature, aortic dissection in pregnant patients is most commonly associated with type A dissection and Marfan syndrome [13]. Approximately 50% of dissections in women under 40 years of age, occur during pregnancy [17]. To date, no reports have described a young patient (under 30 years of age) without underlying connective tissue disease who developed type B aortic dissection following a cesarean section. However, several similar cases have been reported in the literature, highlighting the varied presentations and management strategies for aortic dissection in the postpartum period.

Aortic dissection is predominantly a disease of elderly individuals, with the highest incidence observed in the seventh decade of life [18]. In our case, the patient was a young women without signs of systemic aortitis or Marfan syndrome. The most likely risk factor for the aortic dissection was uncontrolled hypertension, which had been reported.

Pregnancy has been linked to a higher risk of aortic dissection, particularly in the third trimester, during labor and delivery, and up to 3 months postpartum [5,8]. Specifically, aortic dissection after cesarean section occurs in only 0.1–0.3% of all cases of aortic dissection, and in only 0.0004% of pregnancies [19]. In the presented case, the patient was a young woman without underlying connective tissue disease who developed type B aortic dissection following a cesarean section, which is an exceptionally rare occurrence.

Hemodynamic and hormonal changes in the peripartum period have been reported to play a role. The pathogenesis of type B aortic dissection in pregnancy stems from increased aortic wall stress and degeneration of the tunica media. Elevated levels of estrogen and progesterone during pregnancy further prompt aortic dissection. Consequently, total circulatory volume and systemic blood pressure increases [2].

The aortic dissection in our patient likely began during the peripartum period and remained undiagnosed until postpartum complications arose. The presence of malperfusion, specifically irreversible intestinal ischemia, was a critical factor influencing the management strategy. Malperfusion syndromes are common in complicated type B aortic dissection and can result in life-threatening end-organ damage. In this case, the irreversible ischemia of the intestines necessitated surgical intervention, and the patient underwent an initial laparotomy followed by a second laparotomy after transfer to a specialized center.

DIAGNOSIS:

Timely and accurate diagnosis is essential in cases of aortic dissection due to its dynamic progression, clinical similarity to other conditions, and severe complications [1]. The classic presentation is a sudden, severe, tearing pain that often reaches maximum intensity within minutes. Pain location varies depending on the dissection site: anterior chest pain typically indicates ascending aortic involvement, while back pain suggests descending aortic involvement. Pain may also migrate as the dissection extends. Definitive diagnosis relies on advanced imaging modalities, which confirm the diagnosis, classify the dissection, assess the true and false lumens, and evaluate the extent of dissection and urgency indicators [9]. Imaging studies can be used for confirmation of the diagnosis, classification of the dissection, measurement of the size of the false and true lumen, and evaluation of the extent of dissection and urgency indicators. Contrast-enhanced CT, transthoracic echocardiography, transesophageal echocardiography, and magnetic resonance imaging (MRI) are the main diagnostic imaging techniques for detecting aortic dissection [20]. However, the most widely used is contrast-enhanced CT. There is considerable controversy regarding the use of radiation and contrast agent during CT scans in pregnant women’s diagnosis [21]. However, according to previous studies, CT scan has the quickest diagnostic time [22] and is available in most emergency departments with excellent vascular visualization simultaneously [1]. Therefore, during emergencies, the maternal benefits surpass the potential risk for the fetus [21].

In addition, during labor, contractions and pain can lead to significant increases in both systolic and diastolic blood pressure. These hemodynamic changes can be effectively managed through the administration of epidural anesthesia, β-blockers, or vasodilators. In certain cases, cesarean delivery under regional anesthesia may also be warranted [3].

MANAGEMENT:

Type B aortic dissection is divided into complicated and uncomplicated dissections, based on the presence of malperfusion syndrome or rupture and differing treatment methods. Uncomplicated type B aortic dissection can be managed medically with strict blood pressure and heart rate control [11]. The goal is to maintain a systolic blood pressure between 100 and 120 mmHg and a heart rate of approximately 60 beats per minute. First-line agents include short-acting intravenous beta-blockers (eg, esmolol or labetalol), with calcium channel blockers (eg, diltiazem) as alternatives if beta-blockers are contraindicated. Vasodilators (eg, nitroprusside or nicardipine) may be added if further blood pressure control is needed [9].

Complicated type B aortic dissection, characterized by aortic lumen expansion, end-organ ischemia, or rupture, requires intervention [8]. While open surgery was historically the gold standard, TEVAR is now the first-line treatment according to the Society for Vascular Surgery guidelines [2,13,23,24]. A large review by Fattori et al analyzing 6711 patients with type B aortic dissection found early mortality rates of 6.4% for medical therapy, 17.5% for open surgery, and 10.2% for TEVAR [25,26].

TEVAR is a minimally invasive procedure involving stent-graft insertion via the femoral or iliac arteries under fluoroscopic guidance. The stent graft is advanced to the diseased aortic segment, where it is deployed to exclude the pathology (eg, false lumen in dissection or aneurysm sac) and restore normal blood flow through the true lumen. Before the procedure, detailed imaging, such as CT angiography, is performed to assess the anatomy, plan the intervention, and select the appropriate stent-graft size. During the procedure, a sheath is introduced through the femoral or iliac artery, and a guidewire is advanced into the aorta. The stent graft is then positioned at the target site and deployed under fluoroscopic control to ensure accurate placement. After deployment, angiography is performed to confirm proper stent-graft placement, exclusion of the pathology, and absence of complications such as endoleaks. In cases in which femoral or iliac access is not feasible, alternative access routes such as carotid-axillary access may be considered. The use of the carotid and axillary arteries to deliver and deploy thoracic stent grafts has been described, but these approaches are generally reserved for extreme situations where access from the lower extremities is not possible [24].

In the present case, TEVAR was chosen as the primary treatment modality for acute type B aortic dissection diagnosed postpartum following an emergency cesarean section. TEVAR offers advantages over open surgery, particularly in critically ill postpartum patients, by reducing risks associated with major surgery, such as excessive bleeding, prolonged recovery, and postoperative complications [27]. Emerging evidence supports TEVAR as the preferred intervention for acute type B aortic dissection with life-threatening complications, offering superior survival outcomes compared with open surgery [28]. A case series of 4 patients confirmed the safety of TEVAR in women with type B aortic dissection during the third trimester of pregnancy [11]. Another example involves a 30-year-old woman with acute, complicated type B aortic dissection on postpartum day 4, successfully treated with endovascular stent-graft implantation [29].

In our patient, during the TEVAR procedure, initial access through the left common femoral artery failed to confirm the wire’s position within the true aortic lumen. Successful access was then achieved via a right axillary puncture, ensuring precise positioning in the true lumen and safe stent-graft deployment. This approach was critical in securing an optimal outcome while minimizing the risk of further complications.

Although TEVAR is widely used for managing type B aortic dissection in non-pregnant patients, its application in postpartum cases remains less well defined due to limited data. However, in our scenario, TEVAR was considered the most appropriate intervention to restore aortic integrity while minimizing additional surgical risks [27].

Open surgical repair is reserved for cases in which TEVAR is not feasible or for patients with severe complications, as it carries a higher risk of spinal cord ischemia, paraplegia, and renal failure [9,24].

In the presented case, the patient had a history of resistant hypertension, which is why special vigilance was needed throughout the pregnancy to prevent severe complications of aortic dissection. Specialists need to keep in mind comorbidities that significantly increase the risk of aortic dissection – especially uncontrolled hypertension and failed labor. The present case also highlights the importance of selecting the appropriate imaging studies, and how challenging and multi-stage the treatment of complications of unrecognized aortic dissection is.

Conclusions

Acute aortic dissection is rare and associated with high mortality. The present report highlights that hypertension during pregnancy, combined with unsuccessful attempts at delivery, may significantly increase the risk of aortic dissection.

Achieving effective diagnosis and management for these patients is challenging and requires a multidisciplinary approach. Contrast-enhanced CT should be performed as soon as possible due to its diagnostic advantages. The preferred treatment for complicated type B aortic dissection associated with pregnancy is an immediate endovascular approach, which remains the safest method for managing postpartum aortic dissection. Moreover, effective emergency care for these cases requires multidisciplinary collaboration.