A rare case of acute type B aortic dissection involving superior mesenteric artery

A rare case of acute type B aortic dissection involving superior mesenteric artery | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Case Report A rare case of acute type B aortic dissection involving superior mesenteric artery Pengchao Luo, Gaofeng Wang, Feilai Huang, Guofu Wang This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8097702/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Acute type B aortic dissection involving superior mesenteric artery hypoperfusion is a complicated kind B dissection, which is prone to intestinal ischemia and necrosis, and the mortality rate during hospitalization is high. The treatment of a rare patient with acute type B aortic dissection involving the superior mesenteric artery is described in this paper: The patient's dissection involved the superior mesenteric artery far away and the lesion was long, which made it difficult to undergo superior mesenteric artery stent implantation in the first stage. During the conservative treatment of aortic dissection in the hyperacute stage, the clinical symptoms and signs of the chest and abdomen improved significantly, and the combination of preoperative CT angiography (CTA) and intraoperative contrast showed the presence of a coarse compensatory Riolan arch, and the blood flow from the distal branch of superior mesenteric artery was good. Therefore, the patient did not treat the affected superior mesenteric artery at the same time after TEVAR, and the operation went smoothly. However, the patient had sudden abdominal pain and abdominal distension on the 5th day after surgery, and the CTA re-examination showed acute intestinal obstruction, and the condition of the superior mesenteric artery was similar to that before the interaction. Following MDT discussion in the hospital, he was discharged from the hospital after conservative treatment such as fasting water, gastrointestinal decompression, and nutritional support. CTA review a few months after surgery showed good remodeling of the superior mesenteric artery, and there were no adverse symptoms such as abdominal pain and chest pain. Aortic dissection TEVAR Superior mesenteric artery Intestinal insufficiency Riolan’s arch Figures Figure 1 Figure 2 Cases The patient, a 50-year-old male, arrived at the emergency department at night on April 10, 2025 due to “chest and back pain for 1 hour”. He suddenly had tear-like pain in the chest and back, accompanied by profuse sweating, mild abdominal pain, no abdominal distension, and came to the hospital on his own. The patient had never before experienced hypertension, diabetes, hepatitis, heart disease, etc. Admission physical examination: 37.1°C, 95 beats per minute, pulse rate, respiration 19 times per minute, blood pressure 152/86 mmHg. The patient has a painful expression, slight tenderness in the upper abdomen, and no rebound pain. Auxiliary examination: White blood cell count(WBC)16 × 10^9/L in emergency department, neutrophil percentage 86%; The coagulation function in the emergency department showed D-dimer 4.63mg/L，partial thromboplastin time(APTT)20.9 seconds, and fibrinogen(FIB)1.28g/L. Emergency high-sensitivity troponin cTn-I showed 0.001 ng/ml; ECG showing sinus rhythm, normal ECG; Aortic CTA showed aortic dissection formation (DeBakey type III, Stanford B), intimal rupture at the level of the aortic arch (behind the left subclavian artery) (Figure 1A), the celiac trunk artery and left renal artery originated from the true lumen, the right renal artery originated from the false space, the superior mesenteric artery originated from the boundary between the true and false cavities, and the spiral running diaphragm shadow was visible in the mesentery (Figure 1B and C), and there were no obvious abnormalities in the inferior mesenteric artery and bilateral iliac artery. The patient was diagnosed with acute complex type B aortic dissection and admitted to the inpatient ward. After entering the department, the patient’s clinical symptoms and signs of chest and abdomen improved significantly after 1 hour, so after discussion by the department, it was decided to go through the hyperacute phase (7 days of onset) and then further perform TEVAR surgery, during which the patient’s chest and abdomen symptoms and signs were closely monitored. On 2025-4-13 a review of aortic CTA showed that the extent of the filling defect of the superior mesenteric artery could be expanded compared with the previous one (2025-4-10), and it was prone to thrombosis (Figure. 1E and F). The blood routine showed that the white blood cell count (WBC) was 10.9*10^9/L, the percentage of neutrophils was 79%, the proportion of leukocytes and neutrophils was not further increased, and the patient had no symptoms such as abdominal pain and abdominal distension, and it was judged that there were no ischemia and necrosis in the intestines, and the patient's condition changes were closely monitored. He was transitioned to a liquid diet on 2025-4-15 and changed to a soft diet on 2025-4-20, and there was no overt symptom of gastrointestinal discomfort following eating. After completing the preoperative preparation, DSA-guided thoracic aortic stent graft intraluminal isolation and left subclavian artery fenestration stent implantation were performed on 2025-4-23 (12 days after onset), and the operation was smooth. During the operation, the superior mesenteric artery was narrowed and slender, and the lesion segment was long, but the patient had a compensated Riolan’s arch (Figure 1D, G, H), the distal circulation of blood to the superior mesenteric artery was good (Figure 1I), combined with the patient’s symptoms after eating, so it was decided not to treat the superior mesenteric artery for the time being. Post-operative instructions advised the patient to eat soft food, with no obvious discomfort. On 2025-04-28 (5 days post-surgery), the patient suddenly developed abdominal pain and distension. Physical examination showed slight discomfort in the entire abdomen, no rebound soreness, and percussion of the complete abdominal oduced tympanic noises. An urgent abdominal enhanced CT suggested multiple obstructions in the small intestine (Figure 2A), with the condition of the mesenteric artery being similar to that previously. Upon further questioning about the medical history, the patient reported having eaten a lot of greasy food that night. After discussion in the MDT of the hospital, gastrointestinal decompression and placement of an intestinal obstruction catheter were performed (Figure 2B), along with symptomatic treatments such as intestinal lubrication and bowel movement promotion, anti-inflammatory, anticoagulation, and parenteral nutrition. The patient had gradually improved symptoms and indicators of his abdomen and he was discharged 16 days post-surgery. A few months after being discharged, a follow-up CTA indicated good remodeling of the superior mesenteric artery. Until now, the patient has recovered well with no significant discomfort. Discussion Acute aortic dissection (AAD) is caused by various factors leading to a sudden rupture of the aortic intima, which causes blood to flow into the tear in the intima, results in the separation of the intima and media, and forms a double lumen in the aorta. The persistent blood supply to the false lumen can lead to two major complications: aortic rupture and insufficient organ perfusion, even ischemic necrosis. For the majority of the small intestine and some of the colon, the superior mesenteric artery (SMA) is the primary blood supply vessel. Aortic dissection involving the SMA can lead to mesenteric malperfusion (MesMP), and in severe cases, can even result in intestinal ischemic necrosis. Research has shown that intestinal necrosis caused by MesMP has become the second leading cause of death after aortic dissection following aortic rupture, with an in-hospital mortality rate reaching 63.2% [1]. The hemodynamic mechanisms of AAD causing MesMP can be classified into static type, dynamic type, and mixed type. Based on the morphological relationship between the intraluminal membrane and the branch arteries, a study in 2012 proposed the Nagamine classification standard for aortic dissection involving branch arteries [2]. Different morphological classifications determine the degree of MesMP, which often affects the formulation of treatment plans. The ischemic type of SMA in this case is static ischemia (the intimal tear of AAD involves the SMA, and the affected lumen extends relatively long, resulting in thrombus formation in the false lumen and severe compression of the true lumen close to occlusion) (Figure 1). According to morphological classification, this case of SMA involvement belongs to type II-b-2 (which is a “high-risk” subtype, mostly characterized by severe perfusion dysfunction, making it very likely to develop perfusion dysfunction syndrome that jeopardizes life), requiring surgical intervention for endovascular reconstruction of the superior mesenteric artery. For complex type B dissections with acute type B dissection complicated by poor perfusion of the superior mesenteric artery, thoracic endovascular aortic repair (TEVAR) combined with SMA endovascular reconstruction has been recommended as the clinically preferred treatment option by various domestic and international studies. However, the surgical indications and timing for intraluminal reconstruction of SMA are very critical; performing surgery too aggressively may increase the risk of intraoperative stent-related complications [3]. During the TEVAR procedure, the imaging revealed that the true lumen of the SMA was compressed and narrow, with a longer segment of SMA involvement, making stent placement more difficult. Meanwhile, the imaging indicated that this patient had a well-compensated, large Riolan’s arch (Figure 1G), with good blood supply to the distal SMA branches. The Riolan’s arch (AOR, also known as Riolan arterial arch) is an important collateral circulation pathway of the mesenteric vascular system, connecting the middle colic branch of the SMA and the left colic branch of the inferior mesenteric artery (IMA), running along the mesentery root. The incidence of the Riolan’s arch in imaging studies or surgical reports is between 5.5%-11.4%, and it is usually very small or difficult to detect. It compensates as a collateral artery by thickening when the abdominal aorta, superior mesenteric artery, or inferior mesenteric artery becomes stenosed or occluded due to reasons such as arteriosclerosis or dissection embolism [4]. Researches have shown that in patients with spontaneous isolated mesenteric artery dissection, the presence of the Riolan’s arch can significantly alleviate symptoms of intestinal ischemia such as abdominal pain (patients with the Riolan’s arch have lower pain scores and a shorter time to pain relief), and conservative treatment should be prioritized for such patients [5]. Therefore, the patient in this case did not undergo simultaneous mesenteric artery stent implantation after receiving endovascular aortic occlusion surgery. On the fifth day post-operation, the patient suddenly experienced abdominal pain and bloating, with the anus ceasing to pass stool and gas. Physical examination revealed that the abdomen was somewhat tender and that a tympanic sound was produced by percussion of the abdomen. At this time, there were two possibilities: 1. The superior mesenteric artery dissection had worsened, severely affecting the blood supply to the intestines, leading to ischemic bowel obstruction. 2. The patient did not follow dietary guidelines after surgery, resulting in increased intestinal load that triggered bowel obstruction (which was later confirmed through further questioning of the medical history). A subsequent re-examination of the abdominal enhanced CT showed small bowel obstruction, with the condition of the superior mesenteric artery lesions being similar to before (Figure 2A). MDT discussion in the department, it was carefully decided to initially implement gastrointestinal decompression and place an intestinal obstruction catheter, along with symptomatic treatments such as bowel lubrication and constipation relief, anti-inflammatory drugs, anticoagulants, and parenteral nutrition, while closely monitoring the abdominal situation. Subsequently, the patient’s abdominal symptoms and signs gradually improved, and re-examination of blood routine and CRP indicators showed gradual improvement, allowing for discharge 16 days post-operation. Conclusion In the case of an acute type B aortic dissection involving the superior mesenteric artery, whether to perform concurrent endovascular reconstruction of the SMA during TEVAR surgery requires an individualized assessment and analysis based on the intestinal ischemia condition and the compensatory blood supply situation. The successful treatment of this rare patient did not blindly increase the risk of stent-related complications during and after surgery by performing mesenteric artery stent deployment. This not only requires clinicians to have a high ability for perioperative management and comprehensive clinical judgment but also necessitates the involvement of a multidisciplinary team working collaboratively to ultimately benefit the patient. Abbreviations AAD (Acute aortic dissection), SMA (superior mesenteric artery), MesMP (mesenteric malperfusion), TEVAR (thoracic endovascular aortic repair), IMA (inferior mesenteric artery), AOR (Riolan’s arch), MDT (Multi-Disciplinary Treatment). Declarations Ethics approval and consent to participate: This study has been approved by the Medical Ethics Review Committee of Shaoxing Central Hospital. This study and the included clinical information and imaging data were obtained with the patients' informed consent. Consent for publication: Our patient has given written informed consent for their personal or clinical details along with any identifying images to be published in this study. If the journal requires, we can provide a scanned PDF of the written informed consent. Availability of data and materials: All the data involved in this article were provided by the clinical and imaging database of Shaoxing Central Hospital, and the data are authentic and undisputed. Due to ethical restrictions, the raw data cannot be made publicly available. However, de-identified data may be obtained from the corresponding author upon reasonable request. Competing Interests: No potential conflict of interest was reported by the authors. Funding：There was no funding in this research. Authors' contributions: Pengchao Luo and Feilai Huang wrote the main manuscript text, Gaofeng Wang collected images and data, Guofu Wang revised the manuscript and all authors reviewed the manuscript. Acknowledgements: Not applicable. References Bin H 1, Donglin L, Hongkun Z. A focal issue of acute aortic dissection complicated by superior mesenteric artery malperfusion and current status of its diagnosis and treatment. Chin J Vasc Surg. 2024;09(2):129–34. 10.3760/cma.j.cn101411-20240110-00004 . Nagamine H, Ueno Y, Ueda H, et al. A new classification system for branch artery perfusion patterns in acute aortic dissection for examining the effects of central aortic repair. Eur J Cardiothorac Surg. 2013;44(1):146–53. 10.1093/ejcts/ezs631 . Ma T, Dong ZH, Fu WG, et al. Incidence and risk factors for retrograde type A dissection and stent graft-induced new entry after thoracic endovascular aortic repair. J Vasc Surg. 2018;67(4):1026–33. .e2.doi:10.1016/j.jvs.2017.08.070 . Lange JF, Komen N, Akkerman G, et al. Riolan's arch: confusing, misnomer, and obsolete. A literature survey of the connection(s) between the superior and inferior mesenteric arteries. Am J Surg. 2007;193(6):742–8. 10.1016/j.amjsurg.2006.10.022 . Huang X, Li G, Zhang X, et al. Natural Course and Treatment of Symptomatic Spontaneous Isolated Superior Mesenteric Artery Dissection with Total True Lumen Occlusion. Vasc Endovascular Surg. 2023;57(1):41–7. 10.1177/15385744221130836 . Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8097702","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Case Report","associatedPublications":[],"authors":[{"id":574055362,"identity":"33df1fca-c0df-4027-985f-24bc2a5ce8aa","order_by":0,"name":"Pengchao Luo","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Pengchao","middleName":"","lastName":"Luo","suffix":""},{"id":574055363,"identity":"ff385ecb-975a-400a-ae94-8fe749972294","order_by":1,"name":"Gaofeng 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1","display":"","copyAsset":false,"role":"figure","size":521118,"visible":true,"origin":"","legend":"\u003cp\u003e(A) The emergency aortic CTA on 2025-4-10, indicated that the tear of the dissection is located at the level of the aortic arch (behind the left subclavian artery). (B) The layer involved the superior mesenteric artery, with a small true lumen that was severely compressed. (C) Aortic CTA lateral view image. (D) A three-dimensional reconstruction of the aorta CTA showed a large compensatory Riolan's arch between the superior and inferior mesenteric arteries indicated by the arrow. (E) On the follow-up aorta CTA on 2025-4-13, the mesenteric artery dissection displayed a thrombosed false lumen, with the true lumen at the origin no longer visualized. (F) Aortic CTA lateral view image on 2025-4-13. (G) Intraoperative imaging, indicated by the arrow was the prominent compensatory Riolan's arch. (H) Post-operative follow-up aortic CTA three-dimensional reconstruction images. (I) Postoperative re-examination of aortic CTA showed good visualization of the distal mesenteric vessels.\u003c/p\u003e","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-8097702/v1/90dc8e0982cf67c048c40c3c.png"},{"id":100546683,"identity":"ade1e3fe-3e8f-4aaa-8e34-35f61aab8e70","added_by":"auto","created_at":"2026-01-19 08:11:48","extension":"jpeg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":54882,"visible":true,"origin":"","legend":"\u003cp\u003e(A) Emergency full abdominal enhanced CT on 2025-4-28, showed multiple \"bottle sign\" images in the intestines, with multiple obstructions in the small intestine, but the blood supply to the distal mesentery was good. (B) Standing X-ray taken on 2025-4-30 after the implantation of a bowel obstruction catheter, showed partial intestinal dilation with significant air accumulation.\u003c/p\u003e","description":"","filename":"floatimage2.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-8097702/v1/6793eafb883e5ece77dcac4b.jpeg"},{"id":107623074,"identity":"dbeace35-271b-4603-aec6-20f0f96a2c4e","added_by":"auto","created_at":"2026-04-23 09:57:16","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":712527,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8097702/v1/cd19c094-1e30-4374-8b94-9feb163da25b.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"A rare case of acute type B aortic dissection involving superior mesenteric artery","fulltext":[{"header":"Cases","content":"\u003cp\u003eThe patient, a 50-year-old male, arrived at the emergency department at night on April 10, 2025 due to “chest and back pain for 1 hour”. He suddenly had tear-like pain in the chest and back, accompanied by profuse sweating, mild abdominal pain, no abdominal distension, and came to the hospital on his own. The patient had never before experienced hypertension, diabetes, hepatitis, heart disease, etc. Admission physical examination: 37.1°C, 95 beats per minute, pulse rate, respiration 19 times per minute, blood pressure 152/86 mmHg. The patient has a painful expression, slight tenderness in the upper abdomen, and no rebound pain. Auxiliary examination: White blood cell count(WBC)16\u0026nbsp;×\u0026nbsp;10^9/L in emergency department, neutrophil percentage 86%; The coagulation function in the emergency department showed D-dimer 4.63mg/L，partial thromboplastin time(APTT)20.9 seconds, and fibrinogen(FIB)1.28g/L. Emergency high-sensitivity troponin cTn-I showed 0.001 ng/ml; ECG showing sinus rhythm, normal ECG; Aortic CTA showed aortic dissection formation (DeBakey type III, Stanford B), intimal rupture at the level of the aortic arch (behind the left subclavian artery) (Figure 1A), the celiac trunk artery and left renal artery originated from the true lumen, the right renal artery originated from the false space, the superior mesenteric artery originated from the boundary between the true and false cavities, and the spiral running diaphragm shadow was visible in the mesentery (Figure 1B and C), and there were no obvious abnormalities in the inferior mesenteric artery and bilateral iliac artery. The patient was diagnosed with acute complex type B aortic dissection and admitted to the inpatient ward.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u0026nbsp; After entering the department, the patient’s clinical symptoms and signs of chest and abdomen improved significantly after 1 hour, so after discussion by the department, it was decided to go through the hyperacute phase (7 days of onset) and then further perform TEVAR surgery, during which the patient’s chest and abdomen symptoms and signs were closely monitored. On 2025-4-13 a review of aortic CTA showed that the extent of the filling defect of the superior mesenteric artery could be expanded compared with the previous one (2025-4-10), and it was prone to thrombosis (Figure. 1E and F). The blood routine showed that the white blood cell count (WBC) was 10.9*10^9/L, the percentage of neutrophils was 79%, the proportion of leukocytes and neutrophils was not further increased, and the patient had no symptoms such as abdominal pain and abdominal distension, and it was judged that there were no ischemia and necrosis in the intestines, and the patient's condition changes were closely monitored. He was transitioned to a liquid diet on 2025-4-15 and changed to a soft diet on 2025-4-20, and there was no overt symptom of gastrointestinal discomfort following eating. After completing the preoperative preparation, DSA-guided thoracic aortic stent graft intraluminal isolation and left subclavian artery fenestration stent implantation were performed on 2025-4-23 (12 days after onset), and the operation was smooth. During the operation, the superior mesenteric artery was narrowed and slender, and the lesion segment was long, but the patient had a compensated Riolan’s arch (Figure 1D, G, H), the distal circulation of blood to the superior mesenteric artery was good (Figure 1I), combined with the patient’s symptoms after eating, so it was decided not to treat the superior mesenteric artery for the time being. Post-operative instructions advised the patient to eat soft food, with no obvious discomfort. On 2025-04-28 (5 days post-surgery), the patient suddenly developed abdominal pain and distension. Physical examination showed slight discomfort in the entire abdomen, no rebound soreness, and percussion of the complete abdominal oduced tympanic noises. An urgent abdominal enhanced CT suggested multiple obstructions in the small intestine (Figure 2A), with the condition of the mesenteric artery being similar to that previously. Upon further questioning about the medical history, the patient reported having eaten a lot of greasy food that night. After discussion in the MDT of the hospital, gastrointestinal decompression and placement of an intestinal obstruction catheter were performed (Figure 2B), along with symptomatic treatments such as intestinal lubrication and bowel movement promotion, anti-inflammatory, anticoagulation, and parenteral nutrition. The patient had gradually improved symptoms and indicators of his abdomen and he was discharged 16 days post-surgery. A few months after being discharged, a follow-up CTA indicated good remodeling of the superior mesenteric artery. Until now, the patient has recovered well with no significant discomfort.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eAcute aortic dissection (AAD) is caused by various factors leading to a sudden rupture of the aortic intima, which causes blood to flow into the tear in the intima, results in the separation of the intima and media, and forms a double lumen in the aorta. The persistent blood supply to the false lumen can lead to two major complications: aortic rupture and insufficient organ perfusion, even ischemic necrosis. For the majority of the small intestine and some of the colon, the superior mesenteric artery (SMA) is the primary blood supply vessel. Aortic dissection involving the SMA can lead to mesenteric malperfusion (MesMP), and in severe cases, can even result in intestinal ischemic necrosis. Research has shown that intestinal necrosis caused by MesMP has become the second leading cause of death after aortic dissection following aortic rupture, with an in-hospital mortality rate reaching 63.2% [1]. The hemodynamic mechanisms of AAD causing MesMP can be classified into static type, dynamic type, and mixed type. Based on the morphological relationship between the intraluminal membrane and the branch arteries, a study in 2012 proposed the Nagamine classification standard for aortic dissection involving branch arteries [2]. Different morphological classifications determine the degree of MesMP, which often affects the formulation of treatment plans. The ischemic type of SMA in this case is static ischemia (the intimal tear of AAD involves the SMA, and the affected lumen extends relatively long, resulting in thrombus formation in the false lumen and severe compression of the true lumen close to occlusion) (Figure 1). According to morphological classification, this case of SMA involvement belongs to type II-b-2 (which is a “high-risk” subtype, mostly characterized by severe perfusion dysfunction, making it very likely to develop perfusion dysfunction syndrome that jeopardizes life), requiring surgical intervention for endovascular reconstruction of the superior mesenteric artery. For complex type B dissections with acute type B dissection complicated by poor perfusion of the superior mesenteric artery, thoracic endovascular aortic repair (TEVAR) combined with SMA endovascular reconstruction has been recommended as the clinically preferred treatment option by various domestic and international studies. However, the surgical indications and timing for intraluminal reconstruction of SMA are very critical; performing surgery too aggressively may increase the risk of intraoperative stent-related complications [3]. During the TEVAR procedure, the imaging revealed that the true lumen of the SMA was compressed and narrow, with a longer segment of SMA involvement, making stent placement more difficult. Meanwhile, the imaging indicated that this patient had a well-compensated, large Riolan’s arch (Figure 1G), with good blood supply to the distal SMA branches. The Riolan’s arch (AOR, also known as Riolan arterial arch) is an important collateral circulation pathway of the mesenteric vascular system, connecting the middle colic branch of the SMA and the left colic branch of the inferior mesenteric artery (IMA), running along the mesentery root. The incidence of the Riolan’s arch in imaging studies or surgical reports is between 5.5%-11.4%, and it is usually very small or difficult to detect. It compensates as a collateral artery by thickening when the abdominal aorta, superior mesenteric artery, or inferior mesenteric artery becomes stenosed or occluded due to reasons such as arteriosclerosis or dissection embolism [4]. Researches have shown that in patients with spontaneous isolated mesenteric artery dissection, the presence of the Riolan’s arch can significantly alleviate symptoms of intestinal ischemia such as abdominal pain (patients with the Riolan’s arch have lower pain scores and a shorter time to pain relief), and conservative treatment should be prioritized for such patients [5]. Therefore, the patient in this case did not undergo simultaneous mesenteric artery stent implantation after receiving endovascular aortic occlusion surgery.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u0026nbsp; On the fifth day post-operation, the patient suddenly experienced abdominal pain and bloating, with the anus ceasing to pass stool and gas. Physical examination revealed that the abdomen was somewhat tender and that a tympanic sound was produced by percussion of the abdomen. At this time, there were two possibilities: 1. The superior mesenteric artery dissection had worsened, severely affecting the blood supply to the intestines, leading to ischemic bowel obstruction. 2. The patient did not follow dietary guidelines after surgery, resulting in increased intestinal load that triggered bowel obstruction (which was later confirmed through further questioning of the medical history). A subsequent re-examination of the abdominal enhanced CT showed small bowel obstruction, with the condition of the superior mesenteric artery lesions being similar to before (Figure 2A). MDT discussion in the department, it was carefully decided to initially implement gastrointestinal decompression and place an intestinal obstruction catheter, along with symptomatic treatments such as bowel lubrication and constipation relief, anti-inflammatory drugs, anticoagulants, and parenteral nutrition, while closely monitoring the abdominal situation. Subsequently, the patient’s abdominal symptoms and signs gradually improved, and re-examination of blood routine and CRP indicators showed gradual improvement, allowing for discharge 16 days post-operation.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eIn the case of an acute type B aortic dissection involving the superior mesenteric artery, whether to perform concurrent endovascular reconstruction of the SMA during TEVAR surgery requires an individualized assessment and analysis based on the intestinal ischemia condition and the compensatory blood supply situation. The successful treatment of this rare patient did not blindly increase the risk of stent-related complications during and after surgery by performing mesenteric artery stent deployment. This not only requires clinicians to have a high ability for perioperative management and comprehensive clinical judgment but also necessitates the involvement of a multidisciplinary team working collaboratively to ultimately benefit the patient.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cbr\u003e\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eAAD (Acute aortic dissection), SMA (superior mesenteric artery), MesMP (mesenteric malperfusion), TEVAR (thoracic endovascular aortic repair), IMA (inferior mesenteric artery), AOR (Riolan’s arch), MDT (Multi-Disciplinary Treatment).\u003c/p\u003e\n\u003cp\u003e\u003cbr\u003e\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003eEthics approval and consent to participate: This study has been approved by the Medical Ethics Review Committee of Shaoxing Central Hospital. This study and the included clinical information and imaging data were obtained with the patients' informed consent.\u003c/p\u003e\n\u003cp\u003eConsent for publication: Our patient has given written informed consent for their personal or clinical details along with any identifying images to be published in this study. If the journal requires, we can provide a scanned PDF of the written informed consent.\u003c/p\u003e\n\u003cp\u003eAvailability of data and materials: All the data involved in this article were provided by the clinical and imaging database of Shaoxing Central Hospital, and the data are authentic and undisputed. Due to ethical restrictions, the raw data cannot be made publicly available. However, de-identified data may be obtained from the corresponding author upon reasonable request.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eCompeting Interests: No potential conflict of interest was reported by the authors.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eFunding：There was no funding in this research.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAuthors' contributions: Pengchao Luo and Feilai Huang wrote the main manuscript text, Gaofeng Wang collected images and data, Guofu Wang revised the manuscript and all authors reviewed the manuscript.\u003c/p\u003e\n\u003cp\u003eAcknowledgements: Not applicable.\u0026nbsp;\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eBin H 1, Donglin L, Hongkun Z. A focal issue of acute aortic dissection complicated by superior mesenteric artery malperfusion and current status of its diagnosis and treatment. 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Am J Surg. 2007;193(6):742\u0026ndash;8. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.amjsurg.2006.10.022\u003c/span\u003e\u003cspan address=\"10.1016/j.amjsurg.2006.10.022\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHuang X, Li G, Zhang X, et al. Natural Course and Treatment of Symptomatic Spontaneous Isolated Superior Mesenteric Artery Dissection with Total True Lumen Occlusion. Vasc Endovascular Surg. 2023;57(1):41\u0026ndash;7. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1177/15385744221130836\u003c/span\u003e\u003cspan address=\"10.1177/15385744221130836\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Aortic dissection, TEVAR, Superior mesenteric artery, Intestinal insufficiency, Riolan’s arch","lastPublishedDoi":"10.21203/rs.3.rs-8097702/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8097702/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eAcute type B aortic dissection involving superior mesenteric artery hypoperfusion is a complicated kind B dissection, which is prone to intestinal ischemia and necrosis, and the mortality rate during hospitalization is high. The treatment of a rare patient with acute type B aortic dissection involving the superior mesenteric artery is described in this paper: The patient's dissection involved the superior mesenteric artery far away and the lesion was long, which made it difficult to undergo superior mesenteric artery stent implantation in the first stage. During the conservative treatment of aortic dissection in the hyperacute stage, the clinical symptoms and signs of the chest and abdomen improved significantly, and the combination of preoperative CT angiography (CTA) and intraoperative contrast showed the presence of a coarse compensatory Riolan arch, and the blood flow from the distal branch of superior mesenteric artery was good. Therefore, the patient did not treat the affected superior mesenteric artery at the same time after TEVAR, and the operation went smoothly. However, the patient had sudden abdominal pain and abdominal distension on the 5th day after surgery, and the CTA re-examination showed acute intestinal obstruction, and the condition of the superior mesenteric artery was similar to that before the interaction. Following MDT discussion in the hospital, he was discharged from the hospital after conservative treatment such as fasting water, gastrointestinal decompression, and nutritional support. CTA review a few months after surgery showed good remodeling of the superior mesenteric artery, and there were no adverse symptoms such as abdominal pain and chest pain.\u003c/p\u003e","manuscriptTitle":"A rare case of acute type B aortic dissection involving superior mesenteric artery","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-01-16 15:06:11","doi":"10.21203/rs.3.rs-8097702/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"592ba64e-81e9-4ffa-9437-fec421b93e02","owner":[],"postedDate":"January 16th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-04-23T09:56:25+00:00","versionOfRecord":[],"versionCreatedAt":"2026-01-16 15:06:11","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8097702","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8097702","identity":"rs-8097702","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}