Case Report on IVUS of Total Visceral Ischemia Guided Rescue After Endovascular Stent Grafting for Stanford Type B Aortic Dissection

Summary

This protocol describes IVUS-guided rescue of aortic intimal intussusception causing visceral ischemia after TEVAR in a Stanford Type B dissection.

Abstract

This case aims to report and analyze the diagnosis and management of total visceral ischemia caused by aortic intimal intussusception (AII) following thoracic endovascular aortic repair (TEVAR) in a patient with Stanford type B aortic dissection, and to explore the usage of intravascular ultrasound (IVUS) in precise rescue. A 47-year-old male with hypertension presented with acute chest and back pain. Computed tomography angiography (CTA) confirmed Stanford type B aortic dissection, and the patient underwent TEVAR. On postoperative day 3, the patient developed abdominal distension, hypoxemia, and severe deterioration of hepatic and renal function (ALT 4485 U/L, AST 4051 U/L, creatinine 259.3 µmol/L), indicating total visceral ischemia. To avoid contrast-induced nephropathy, IVUS was used in the reintervention to clearly diagnose severe distal true lumen compression caused by AII (true/false lumen ratio 6:1). Under IVUS guidance, two bare stents were successfully implanted, and tri-lobe balloon dilation was performed to restore true lumen patency. Post-intervention, visceral ischemia symptoms gradually resolved, and early follow-up CTA confirmed that all visceral arteries were perfused through the true lumen. At the 3-month follow-up, the patient's hepatic and renal function returned to normal (ALT 15 U/L, creatinine 86.1 µmol/L), and he had resumed daily activities. This case confirms the critical role of IVUS in reducing contrast use, accurately evaluating vascular anatomy, and guiding stent deployment, providing a practical reference for the diagnosis and management of complex complications after TEVAR.

Introduction

The primary objective of this case report is to demonstrate the value of intravascular ultrasound in the diagnosis and guided treatment of AII-induced total visceral ischemia following TEVAR for Stanford Type B aortic dissection, and to highlight its potential role in optimizing complex endovascular protocols. TEVAR has become the standard treatment for Stanford Type B aortic dissection, offering the advantages of minimal invasiveness and reduced perioperative morbidity compared with open surgery¹. However, rare complications such as AII can occur, leading to life-threatening visceral ischemia with high mortality if not promptly addressed^2,3. Epidemiological data show that the probability of AII occurring after TEVAR surgery for type B dissection is approximately 1.28%³, with most cases reported as isolated case studies or small series. Its subtle clinical presentation and potential for rapid progression to multiorgan failure make early recognition difficult, often leading to delayed intervention and poor outcomes². This case adds to the limited literature by detailing the successful rescue of a patient with total visceral ischemia using IVUS guidance, addressing a critical knowledge gap in managing this catastrophic complication.

Compared with alternative imaging modalities, IVUS offers several key advantages in such scenarios: Firstly, it provides high-resolution cross-sectional imaging of the aortic lumen, clearly delineating true/false lumen anatomy and intimal flap dynamics without relying on iodinated contrast, thus avoiding contrast-induced nephropathy-a significant risk in patients with preexisting renal impairment or multiorgan dysfunction^4,5. Meanwhile, the guidelines of the American Society for Vascular Surgery (SVS) recommend that when the CT image quality is poor or the contrast agent needs to be reduced, IVUS should be recommended to assess the landing zone⁶ (Level of recommendation: Grade 1; Quality of Evidence: A ). Secondly, IVUS enables real-time procedural guidance, allowing precise stent placement and assessment of stent expansion, which is particularly valuable in complex anatomies where angiographic visualization is limited⁷.

Approximately 87 cases of AII were reported from 1980 to 2021, and those related to TEVAR were even rarer (approximately 1.28%)^3,8. Most were case reports, lacking large-sample cohort studies. The majority focused on intraoperative identification and conversion to open surgery ^2,3. Gaps in current knowledge include the lack of standardized diagnostic criteria, optimal timing for intervention, and consensus on technical approaches for endovascular management. Existing reviews and registry data highlight the need for more evidence on imaging-guided strategies to improve outcomes in these high-risk cases⁶.

The present case is clinically relevant for readers evaluating similar scenarios, as it illustrates key criteria for applicability: patients with uncontrolled hypertension (a major risk factor for aortic dissection and AII), extensive dissection involving the thoracoabdominal aorta, and post-TEVAR deterioration with signs of visceral ischemia (e.g., abdominal pain, elevated liver/renal biomarkers). These features align with previously reported risk factors for AII, emphasizing the importance of tailored imaging and intervention in such populations^3,6.

Case Presentation:

A 47-year-old Asian male with a body mass index (BMI) of 33.1 kg/m² (weight 90 kg, height 165 cm) presented to the emergency department with a 6 h history of sudden-onset, severe, and persistent chest and back pain accompanied by profuse sweating. He had a 5-year history of uncontrolled hypertension, with irregular use of unspecified antihypertensive medications; his highest recorded blood pressure was 180/115 mmHg. There was no history of smoking, alcohol consumption, or prior surgical interventions. On admission, physical examination revealed a temperature of 36.8 °C, pulse of 90 beats/min, respiratory rate of 24 breaths/min, blood pressure of 174/135 mmHg, and oxygen saturation of 99% on room air. Physical examination revealed only mild epigastric tenderness, without any other positive signs such as fever, abdominal distension, nausea, or vomiting. Initial laboratory tests on admission showed normal hepatic and renal function: alanine transaminase (ALT) 37 U/L (reference range 9-50 U/L), aspartate transaminase (AST) 24 U/L (reference range 15-40 U/L), and creatinine (CREA) 82.9 µmol/L (reference range 57-111 µmol/L).

Computed tomography angiography (CTA) confirmed Stanford Type B aortic dissection, with primary entry tears extending from the descending aorta (3 cm distal to the left subclavian artery) to the right common iliac artery (Figure 1A-B). The aorta and iliac arteries showed a double-lumen appearance with extensive linear low-density intimal flaps and multiple tears; the true lumen was small, and the false lumen was large. The celiac artery, superior mesenteric artery, inferior mesenteric artery, and bilateral renal arteries were supplied by the true lumen.

On day 5 post-admission, an aortic stent-graft was deployed with initial success (Figure 2A-C). Post-TEVAR angiography revealed delayed contrast filling in the visceral arteries through the false lumen compared to the true lumen. Unfortunately, this angiographic detail was neglected at that time. The patient experienced transient abdominal pain upon recovery from general anesthesia. However, by postoperative day 3, the patient developed abdominal distension, hypoxemia, and laboratory evidence of severe hepatic/renal function injury (ALT 4485 U/L, AST 4051 U/L, creatinine 259.3 µmol/L).

To avoid contrast-induced nephropathy, a PV.035 digital IVUS catheter was used in the reintervention. During the reintervention, IVUS revealed a distal AII and true lumen severely compressed by false lumen (Figure 3A-B). Under IVUS guidance, two bare stents were deployed to connect to the proximal stent-graft and expand the distal collapsed true lumen (Figure 3C). After deployment of the bare stent, the bare stent did not expand well (Figure 3D) and was dilated by a tri-lobe balloon (Figure 3E). Post-intervention, the visceral ischemia recovered gradually, and postoperative review of aortic CTA showed that all organs were supplied by the true lumen (Figure 4A-D). The patient was discharged in stable condition. At 3-month follow-up, hepatic and renal function had normalized (ALT 15 U/L, CREA 86.1 µmol/L), and he had resumed daily activities (Table 1).

Diagnosis, Assessment, and Plan: The initial diagnosis of Stanford Type B aortic dissection was established based on clinical presentation and CTA findings. Preoperative CTA clearly demonstrated a double-lumen sign from the descending aorta to the right common iliac artery, with the true lumen supplying the celiac artery, superior mesenteric artery, and bilateral renal arteries, confirming the diagnosis. Intraoperative angiography guided initial stent-graft deployment but was limited by contrast reliance and potential perfusion deficit underestimation⁷.

The diagnosis of postoperative aortic intimal intussusception was prompted by clinical deterioration on postoperative day 3, characterized by abdominal distension, hypoxemia, and a marked rise in hepatic (ALT 4485 U/L) and renal (creatinine 259.3 µmol/L) biomarkers-classic signs of visceral ischemia³. IVUS was urgently employed for definitive diagnosis, as it avoids contrast-induced nephropathy in renal-impaired patients and provides high-resolution cross-sectional imaging of lumen dynamics⁴. IVUS revealed a distal AII with severe true lumen compression (true/false lumen ratio 1:3), confirming that intimal detachment and distal migration were the causes of visceral malperfusion³ (Figure 3B).

During differential diagnosis, other potential causes of post-TEVAR visceral ischemia were considered, including branch artery occlusion (e.g., celiac or renal artery stenosis), stent-graft migration, type I/III endoleak, or distal stent-graft-induced new entry tears. However, these were excluded by IVUS findings (no stent malposition or endoleak) and CTA follow-up (no isolated branch occlusion).

The treatment plan was tailored to address the underlying AII while minimizing renal risk. IVUS-guided bare stent placement was chosen to reconnect the proximal stent-graft with the distal collapsed true lumen, as bare stents provide structural support without occluding visceral branches. Post-deployment balloon dilation with a tri-lobe balloon was performed to ensure optimal stent expansion, as suboptimal stent wall apposition is a known risk factor for stent thrombosis⁹. This approach avoided repeat contrast use, critical given the patient's acute kidney injury. Potential complications of the intervention, including vascular injury during IVUS catheter insertion, stent malapposition, and distal embolization, were mitigated by careful procedural technique and real-time IVUS monitoring. No procedural complications occurred, and post-intervention imaging confirmed restored true lumen perfusion.

Protocol

​This project was approved by the Medical Technology Ethics Committee of Guilin Hospital of the Second Xiangya Hospital of Central South University. Written informed consent was obtained from the patient prior to the intervention, including permission for the use of clinical data and images for research purposes.

1. Pre-reintervention preparation

1. Clinical indication: True lumen collapse and visceral ischemia were suspected following initial TEVAR for Stanford Type B aortic dissection.
2. Imaging review: Prior CTA and intraoperative angiography were analyzed to identify residual false lumen flow and true lumen compression.
3. Device preparation: IVUS catheter, bare stents, and tri-lobe balloon were prepared.
4. Renal protection: The amount of contrast agents used for angiography was reduced. IVUS use was preferred for procedural guidance.
5. Pre-reintervention Diagnosis and Assessment: CTA was selected to be the primary diagnostic tool as the primary preoperative diagnostic modality for Stanford Type B aortic dissection, given its high sensitivity and specificity for identifying aortic dissection anatomy. CTA was used to confirm key anatomical features, including the extent of the dissection, location of entry tears, and perfusion status of visceral arteries (celiac artery, superior mesenteric artery, bilateral renal arteries)⁶. Intraoperative angiography was employed to guide initial stent-graft deployment, enabling real-time visualization of the true lumen and stent position. However, its limitations (reliance on iodinated contrast, potential underestimation of subtle perfusion deficits) were noted, prompting the subsequent use of IVUS for reintervention⁷.

2. IVUS-guided reintervention

1. Femoral Access: Local anesthesia was administered with 1% lidocaine (5-10 mL). The femoral artery was punctured using the Seldinger technique. An ultrasound-guided percutaneous puncture was made with a 21G micropuncture needle, followed by insertion of a 0.035-inch guidewire, and sequential dilation with a 5 F dilator to introduce a 6 F sheath (inner diameter: 2.0 mm; material: polyurethane). Pre-deploy vascular closure devices were placed to facilitate hemostasis post-procedure.
2. During the operation, the changes in the patient's vital signs were monitored, including heart rate, blood pressure, blood oxygen saturation, respiratory rate, etc. Intraoperative anticoagulation plan: intravenous injection of heparin (dose: 4000IU) was administered to achieve an activated coagulation time (ACT) of 250-300 s. Since the effect of heparin naturally subsided after the operation, no reversal drugs were used.
3. True Lumen Navigation: A 0.035-inch guidewire and a single-curve catheter were advanced to the ascending aorta under fluoroscopy. True lumen position was confirmed with IVUS imaging, ensuring the guidewire tip is visualized within the true lumen to avoid false lumen entry.
4. IVUS assessment of aortic pathology: The IVUS catheter was deployed to visualize distal true lumen collapse (true/false lumen ratio 6:1). The ratio was calculated by comparing cross-sectional areas (CSAs) of the true and false lumens. CSA was measured by manually tracing the lumen boundary on IVUS images, with a ratio >3:1 indicating severe compression. The cause of persistent false lumen perfusion compressing the true lumen was identified.
5. Bare stent deployment
   1. First stent deployment: The bare stent was delivered over a super-stiff guidewire. The stent was positioned into the proximal stent-graft and overlapped by 3 cm with the prior stent-graft. The stent was deployed under fluoroscopic guidance. The IVUS catheter was exchanged under fluoroscopy (maintaining guidewire position) to confirm that the distal end of the stent remains in the collapsed true lumen, indicating the need for a second bare stent.
   2. Second stent deployment: Another bare stent was delivered into the prior bare stent and overlapped by 3 cm with the first one. The stent was deployed fully to open the distal true lumen.
6. Post-stent optimization: A tri-lobe balloon was inflated within the stents to 8-10 atm to ensure complete apposition and expansion of the bare stent and true lumen.
7. Final verification: The IVUS catheter was exchanged using the same guidewire to maintain access to confirm the true lumen expansion status, the position of the two bare stents, and the visceral artery reperfusion situation. Limited contrast angiography was performed (if renal function permits) to validate the results.

3. Post-procedural management

1. Hemodynamic stabilization: Mean arterial pressure (MAP) was maintained at 70-90 mmHg using vasoactive medications if needed.
2. Multi-organ function monitoring: Hepatic (ALT/AST) and renal (creatinine) function biomarkers were tracked daily until normalization.
3. Long-term follow-up: CTA was scheduled at 1, 3, and 12 months to assess aortic remodeling and stent integrity.
4. Procedural endpoints: The primary endpoint was ≥ 95% true lumen patency on IVUS immediately post-intervention. The procedure was terminated if: True lumen expansion was confirmed by IVUS; no residual obstruction in visceral arteries; no procedural complications (e.g., vessel rupture, severe dissection).

Results

AII represents a rare yet catastrophic complication of TEVAR. Postoperative surveillance for true lumen integrity, especially in high-risk patients, is paramount. IVUS-guided strategies offer a safe and effective approach for managing such cases, particularly in renal-compromised patients. Early imaging and tailored interventions significantly improve outcomes.

In this Case, IVUS-guided reintervention proved critical in restorin...

Discussion

AII, characterized by circumferential intimal detachment and distal migration, remains a rare but life-threatening complication of TEVAR. Our case demonstrates that IVUS-guided intervention not only resolved true lumen collapse but also restored visceral perfusion while mitigating contrast-related risks in a renal-impaired patient. This aligns with emerging evidence highlighting IVUS's superiority in complex aortic pathologies^5,7. The pathogenesis of AII like...

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Aortic Stent-graft	Lifetech	REF:TAA3024B200	The size and length of the stent?a proximal diameter of 30mm, a distal diameter of 20mm, and a length of 200mm
Bare Stents	Hangzhou Wei-Qiang Medical Technology Co	DM-TB-2828100;DM-TB-2626100	The size and length of the stent?DM-TB-2828100--a proximal diameter of 28mm, a distal diameter of 28mm, and a length of 100mm DM-TB-2626100--a proximal diameter of 26mm, a distal diameter of 26mm, and a length of 100mm
Tri-lobe Balloon	W.L.Gore&Associates,Inc.	BCL2645	-
Vision PV .035 Digital IVUS Catheter	Volcano corporation	REF:88901	-