Multimodal Imaging of an Atherosclerotic Splenic Artery Aneurysm Enables Endovascular Treatment of a Potentially Lethal Entity

Kothandam Sivakumar; Sandeep Mohanty

doi:10.4103/jiae.jiae_49_21

INTERESTING CASE REPORT

Year : 2022 | Volume : 6 | Issue : 2 | Page : 142-145

Multimodal Imaging of an Atherosclerotic Splenic Artery Aneurysm Enables Endovascular Treatment of a Potentially Lethal Entity

Kothandam Sivakumar, Sandeep Mohanty
Department of Pediatric Cardiology, Institute of Cardiovascular Diseases, The Madras Medical Mission, Chennai, Tamil Nadu, India

Date of Submission	15-Aug-2021
Date of Acceptance	12-Sep-2021
Date of Web Publication	15-Nov-2021

Correspondence Address:
Dr. Kothandam Sivakumar
Department of Pediatric Cardiology, Institute of Cardiovascular Diseases, The Madras Medical Mission, 4A, Dr. J J Nagar, Mogappair, Chennai - 600 037, Tamil Nadu
India

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/jiae.jiae_49_21

Abstract

Splenic artery aneurysms (SAAs) are the third most frequent site of intraabdominal aneurysm and the most frequent splanchnic artery aneurysm. Surgery may be morbid and may include splenectomy and distal pancreatectomy. True aneurysm needs differentiation from a pseudoaneurysm caused by pancreatic enzymatic destruction. A giant SAA was diagnosed in an elderly atherosclerotic male with chronic calcific pancreatitis. Layered thrombus on multimodal imaging ruled out enzyme action and excluded possibility of a pseudoaneurysm. The distal splenic artery beyond the aneurysm was collateralized by left gastric artery. The aneurysm was closed with multiple coils and a vascular plug. Imaging after 6 months confirmed complete closure. Endovascular closure of SAA needs strategies to avoid an endoleak from the distal splenic artery. Pseudoaneurysm of splenic artery should be excluded, as they do not respond to the same strategies applied for true atherosclerotic aneurysms.

Keywords: Atherosclerosis, calcific pancreatitis, coil embolization, endovascular treatment, prevention of endoleak, vascular plug

How to cite this article:
Sivakumar K, Mohanty S. Multimodal Imaging of an Atherosclerotic Splenic Artery Aneurysm Enables Endovascular Treatment of a Potentially Lethal Entity. J Indian Acad Echocardiogr Cardiovasc Imaging 2022;6:142-5

How to cite this URL:
Sivakumar K, Mohanty S. Multimodal Imaging of an Atherosclerotic Splenic Artery Aneurysm Enables Endovascular Treatment of a Potentially Lethal Entity. J Indian Acad Echocardiogr Cardiovasc Imaging [serial online] 2022 [cited 2023 Sep 27];6:142-5. Available from: https://jiaecho.org/text.asp?2022/6/2/142/330499

Introduction

Splenic artery aneurysms (SAAs) are the most frequent splanchnic artery aneurysms and constitute about 50%–70% of these aneurysms.^[1] SAAs are the third most frequent intraabdominal aneurysms, following abdominal aorta and iliac artery aneurysms.^[2] Open or laparoscopic surgery is a common treatment associated with morbidity including splenectomy and distal pancreatectomy. Recently, endovascular treatments with stent-grafts, coil embolization, plug deployment, or glue have been used and are often more successful. This report details a patient with a rapidly progressive symptomatic large SAA that needed differentiation from a pseudoaneurysm before endovascular treatment. Multimodal imaging was crucial for diagnosis, differentiation, and management.

Case Report

Four years after coronary artery bypass graft surgery, ultrasound scan for acute severe epigastric pain in a 63-year-old male showed a recent onset large 9 cm SAA, displacing the body of pancreas on computed tomography [Figure 1]. He was previously diagnosed to have chronic calcific pancreatitis, 10 years earlier during another tomogram, but no aneurysms were identified in the past. His atherosclerotic risk factors included diabetes mellitus on oral hypoglycemic drugs, poorly controlled systemic hypertension despite medications and dyslipidemia. He was receiving dual antiplatelet therapy for coronary atherosclerosis. The abdominal aorta and iliac arteries showed multiple atheromatous plaques with significant luminal narrowing of origins of the left renal artery and left internal iliac artery. Thrombus lining along the postero-inferior walls of the aneurysm that was closely related to the pancreatic tissue excluded a pseudoaneurysm secondary to the longstanding pancreatitis and changed the management, as pancreatic enzymes would have dissolved the clots [Figure 2]. A multidisciplinary care team reviewed the case and approved endovascular treatment. The patient was explained about the treatment plan and the associated risks/benefits and consented for the procedure.

Figure 1: Splenic artery aneurysm. After diagnosis on abdominal ultrasound (a), computed tomography show a thrombus-lined aneurysm (b) displacing the pancreas (c) which showed extensive calcifications (d). Coronal (e) and axial (f) computed tomographic images confirmed total seal of the aneurysm after six months

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Figure 2: Volume rendered images. Volume-rendered color-coded computed tomography (a) delineates the aneurysm with distal splenic artery collateralized through left gastric artery. Aorta and branches show atheromatous calcifications. Axial (b) and coronal (c) virtual dissection show thrombus-filled aneurysm near the pancreas and stomach. Vessel volume rendering (d) shows aortic, left renal, and left internal iliac arterial calcifications and atherosclerotic narrowing

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Procedure

Femoral artery vascular access was obtained followed by heparinization. Fluoroscopy showed large specks of calcifications in head, body, and tail of pancreas. Coeliac artery was cannulated deeply using a mother-and-child technique that utilized outer 6F right Judkins 100 cm coronary guide catheter, inner 4F Judkins 110 cm right coronary diagnostic catheter over two 0.014” floppy coronary guidewires. After delineating the extent of the aneurysm by an injection within the sac, twenty-one Gianturco Dacron fibred embolization 0.038” coils (Cook Medical, Bloomington, IN, USA) were deployed to pack the aneurysm to prevent endoleak from the collateralized distal splenic artery. The entry to the aneurysm was closed with an 8 mm Amplatzer vascular Plug II (Abbott, Plymouth, MN, USA) through the guide catheter to seal the entry [Figure 3] and [Supplemental Video 1]. Coeliac arteriogram showed SAA obliterated by the coils and plugs and left gastric artery collateralizing the distal splenic artery [Supplemental Video 2]. A concurrent stent angioplasty for a left renal artery stenosis with a 5 mm drug eluting cobalt chromium stent enabled optimal postprocedure blood pressure control. After 6 months, he was asymptomatic with normal blood pressures and no residual aneurysms [Figure 1].

Figure 3: Intervention. Before plugging the origin with a vascular plug, anteroposterior (a) and lateral (b) projections show packing of the aneurysm with coils (c) to prevent distal endoleak from distal splenic artery (d)

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Video 1: Closure of the entry of the aneurysm with 8 mm Amplatzer vascular plug II

[Additional file 1]

Video 2: Coeliac arteriogram showing splenic artery aneurysm obliterated by the coils and plugs and left gastric artery collateralizing the distal splenic artery

[Additional file 2]

Discussion

SAAs are the third most frequent site of intra-abdominal aneurysms after aorta and iliac arteries and the most frequent among the splanchnic artery aneurysms.^[1] Guidelines suggest closure of aneurysms larger than 2 cm as they are prone for rupture, erosion, and death.^[2] True aneurysms that are often atherosclerotic in origin need to be differentiated from a pseudoaneurysm that is caused by pancreatic enzyme action.^[3] Risk of rupture increases in portal hypertension, liver transplant recipients, and pregnancy. Rupture is common in males and smokers.^[4] Occasionally, aneurysm can erode into adjacent organs or into pancreatic duct and present as gastrointestinal bleeding.^[4] Recent onset of acute pain indicated a possibility of impending rupture in our patient.

The precise etiology of SAAs and pseudoaneurysms remains unknown. About 80% of true aneurysms show atherosclerotic changes and calcification and are thought to be associated with hypertension, cirrhosis, and pregnancy. Pseudoaneurysms are related to pancreatitis, abdominal trauma, surgery, and rarely peptic ulcer disease. Pancreatic enzymes cause necrotizing arteritis with destruction of vessel architecture and fragmentation of elastic tissue leading to formation of pseudoaneurysms.^[3] In spite of coexistent chronic calcific pancreatitis in our patient, layered thrombus indicated that the pancreatic enzymes were not in direct contact with the sac, thereby excluding a pseudoaneurysm. Multiple atherosclerotic risk factors and involvement of other vessels including renal, coronary and iliac arteries indicated that our patient had true aneurysm. Pseudoaneurysms have higher mortality and reintervention rates.^[5]

Therapeutic options include conventional open surgery that involve ligation of the artery, partial or total splenectomy and occasionally distal pancreatectomy, endovascular treatment, and recently laparoscopic surgery.^[6] Open surgery carries mortality of 1.3%–4.9% and significant morbidity.^[6],[7] Endovascular embolization and covered stents are alternative options. Advantages over surgery include accurate localization of the aneurysm, assessment of collateral flow, applicability in poor surgical candidates, and easy approach to aneurysms with poor surgical exposure.^[8] Coil embolization is safe and effective but covered stents may be preferred in nontortuous vessels for maintaining patency of the vessel.^[9] A retrograde filling from the distal splenic artery that was collateralized by the left gastric artery was prevented by packing the aneurysmal sac with multiple coils. Recanalization of aneurysms after multiple coil embolization is challenging due to difficulties in navigating across potentially obstructing coils.^[10]

Conclusions

True and pseudo SAAs need to be differentiated before management.

Strategies should be made to prevent endoleaks from other collateral arteries. Acute-onset pain indicated a possibility of impending rupture that was averted by timely intervention. When previous coronary surgery and other comorbidities increase the surgical risk, endovascular management is the preferred option in SAAs. The additional advantages include ability to perform other interventions such as renal angioplasty.

Consent to publish

Informed consent for the treatment and anonymous display of images in publications was obtained.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given his consent for his images and other clinical information to be reported in the journal. The patient understands that name and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

K Sivakumar is an editorial board member of the Journal of The Indian Academy of Echocardiography & Cardiovascular Imaging. The article was subject to the journal's standard procedures, with peer review handled independently of this editor and their research groups.

There are no other conflicts of interest.

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