Indian Journal of Vascular and Endovascular Surgery

CASE REPORT
Year
: 2021  |  Volume : 8  |  Issue : 4  |  Page : 381--383

Superior mesenteric vein aneurysm: A case report with 2-year follow-up


Ayushica Saran, Thomas Lovelock, Thodur Vasudevan, Peter Charalabidis 
 Department of Vascular Surgery, The Alfred Hospital, Melbourne, VIC, Australia

Correspondence Address:
Thomas Lovelock
Department of Vascular Surgery, The Alfred Hospital, Melbourne, VIC
Australia

Abstract

Visceral venous aneurysms (VVAs) are rare, accounting for 3% of all venous aneurysms. We present a case of a 73-year-old man diagnosed with an incidental 3.3 cm superior mesenteric vein (SMV) aneurysm, which has been managed conservatively for over 2 years. A 73-year-old man presented to the emergency department with a 1-week history of abdominal pain, generalized fatigue, and multiple episodes of vomiting. A contrast-enhanced computed tomography scan of the abdomen and pelvis was performed. This demonstrated an incidental multilobulated SMV aneurysm at the level of the inferior aspect of the uncinate process of the pancreas, with a maximal diameter of 25 mm. We have successfully managed this conservatively with serial imaging for 2 years. There are only 17 reported cases of SMV aneurysms, most of which occur at the confluence of the splenic vein. Ours occurred in the distal SMV. Due to their rarity, there is no standardized management approach for VVAs. Treatment is only proposed for VVAs with increasing size or rupture, thrombosis, or compression of local structures. We provide our experience in successfully managing an uncomplicated SMV aneurysm conservatively.



How to cite this article:
Saran A, Lovelock T, Vasudevan T, Charalabidis P. Superior mesenteric vein aneurysm: A case report with 2-year follow-up.Indian J Vasc Endovasc Surg 2021;8:381-383


How to cite this URL:
Saran A, Lovelock T, Vasudevan T, Charalabidis P. Superior mesenteric vein aneurysm: A case report with 2-year follow-up. Indian J Vasc Endovasc Surg [serial online] 2021 [cited 2022 May 19 ];8:381-383
Available from: https://www.indjvascsurg.org/text.asp?2021/8/4/381/332050


Full Text



 Introduction



Visceral venous aneurysms (VVAs) are rare, accounting for 3% of all venous aneurysms.[1]

Nine percent of VVAs involve the superior mesenteric vein (SMV).[1] There is a sparsity of literature regarding the optimal management of these entities. We present a case of a 73-year-old man, incidentally diagnosed with a 3.3 cm SMV aneurysm, which has been managed conservatively for 2 years.

 Case Report



A 73-year-old man presented to the emergency department with a 1-week history of crampy abdominal pain, generalized fatigue, and multiple episodes of vomiting. He denied any change in bowel habit, hematochezia, melena, weight loss, or other constitutional symptoms. His medical history included type 2 diabetes mellitus, controlled with oral hypoglycemic agents, hypertension, and chronic constipation. He was a nonsmoker.

On examination, he was hemodynamically normal. He was vomiting. His abdomen was mildly distended and tender to palpation in the epigastric and periumbilical regions. There were no signs of organomegaly or abdominal rigidity. A per-rectal examination revealed only an enlarged prostate. Pedal pulses were present.

A contrast-enhanced computed tomography (CT) scan of the abdomen and pelvis was performed, given clinical suspicion for a bowel obstruction. This scan did not reveal any gastrointestinal pathology, however, did demonstrate an incidental finding of a SMV aneurysm, which was irregular and multilobulated, at the level of the inferior aspect of the uncinate process of the pancreas [Figure 1]. It was 25 mm in maximal diameter, measured in the coronal plane. The patient underwent an inpatient gastroscopy, which revealed a duodenal ulcer. This was treated with pantoprazole twice daily and outpatient gastroenterology clinic follow-up. On discharge, the patient was referred to the vascular surgery outpatient clinic for follow-up.{Figure 1}

The patient was initially monitored with biennial imaging. A duplex ultrasound performed at the 6-month mark could not identify the aneurysm, so it was decided to perform ongoing follow-up imaging with CT scanning. At 1 year after diagnosis, there was a mild increase in the aneurysm size with a new maximal diameter of 33 mm in the coronal plane. The aneurysm did not exhibit significant mass effect on the adjacent pancreas, duodenum, or superior mesenteric artery. There was no evidence of fat stranding surrounding the aneurysm nor there were any other arterial or venous aneurysms identified. Diffuse fatty infiltration of the liver prompted a referral to the liver clinic for follow-up of chronic liver disease and portal hypertension, which was thought to be a possible etiology of the aneurysm. At 2-year follow-up, the patient remains asymptomatic, with the aneurysm now stable in size. The patient is planned for ongoing annual surveillance with CT venography.

 Discussion



The SMV is considered aneurysmal when the vessel diameter exceeds 1.4 cm, and there is a loss of vessel wall parallelism.[2] The majority of SMV aneurysms are located near its confluence with the splenic vein, and these patients may also demonstrate portal vein dilation. This was not the case in our patient, whose aneurysm was located in a more distal segment of the SMV.[3] Most patients are asymptomatic, with their aneurysms detected incidentally.[1],[3] VVAs may be complicated by thrombosis, rupture, or compression of anatomical structures.

The exact mechanisms underlying the formation of VVAs are unknown. Congenital aberrant regression of the caudal aspect of the right vitelline vein may form a diverticulum that can persist and cause weakness of the vessel wall.[1],[2],[3] Acquired factors such as hepatic disease, portal hypertension, local inflammation (such as from adjacent pancreatitis), trauma, and surgery may also predispose patients to VVA formation.[3]

SMV aneurysms are usually asymptomatic; however, patients may present with vague recurrent abdominal pain.[3] Patients may also present following complications of aneurysm rupture (usually with gastro-intestinal bleeding), thrombosis, or compression of local structures such as the biliary tree.[3],[4] With compression of the biliary tree, there may be concomitant hyperbilirubinemia or transaminitis.[3] Three cases of rupture of VVAs have been reported, with one instance being fatal.[1],[4] Our patient presented with abdominal pain attributable to the presence of a duodenal ulcer.

Radiological findings are generally required to establish a diagnosis of SMV aneurysm, since most are clinically silent. Color Doppler ultrasonography is often performed as an initial noninvasive measure to establish the location and vascular nature of the mass. CT with intravenous iodine contrast enhancement and magnetic resonance imaging allow further multiplanar characterization of the location, size, and vascular origin of the lesion.[1],[2],[3]

Due to their rarity, no standardized approach to SMV aneurysms exists. Asymptomatic cases are usually managed with observation and annual imaging for surveillance. A collective review of reports describing VVAs found that 94% of described cases demonstrated a stable aneurysmal diameter and no complications when surveilled with follow-up duplex ultrasound.[1],[5] Hence, treatment is only proposed for aneurysms that are increasing in size or complicated (by either rupture, thrombosis, or compression of local structures).[1],[5] Recently, the necessity of intervention for these indications has also been disputed, as open repair carries a mortality rate of approximately 20%.[6] The management of ruptured or enlarged aneurysms is typically by open surgery, with ligation, resection with primary end-to-end anastomosis or interposition bypass, and tangential aneurysmectomy with lateral venorrhaphy all described in the literature.[5] The majority of these operative strategies recommend anticoagulation postoperatively for at least 3 months.[5] Transposition of the inferior mesenteric vein has been described in the case of a symptomatic left renal vein aneurysm, although this has not been applied in the setting of SMV aneurysms.[7] Successful endovascular management of SMV aneurysm thrombosis has been described with transarterial thrombolysis and transhepatic suction thrombectomy, although open thrombectomy or tangential venorrhaphy remains other options.[5],[8] Anticoagulation for at least 3 months is also recommended following any of these procedures.[5]

 Conclusion



SMV aneurysms remain a rare entity. We provide our experience in managing a patient who presented to our institution with an SMV aneurysm, managed conservatively with 2-year follow-up. A number of treatment options exist for the management of SMV aneurysms, which should be reserved for patients with complicated aneurysms or uncomplicated aneurysms significantly increasing in size.

Declaration of patient consent

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

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1Sfyroeras GS, Antoniou GA, Drakou AA, Karathanos C, Giannoukas AD. Visceral venous aneurysms: Clinical presentation, natural history and their management: A systematic review. Eur J Vasc Endovasc Surg 2009;38:498-505.
2Billaud Y, Pilleul F, Meyer X, Ehre P, Weber G, Henry L, et al. Aneurysm of the superior mesenteric vein: Imaging findings. J Radiol 2003;84:857-60.
3Wolosker N, Zerati AE, Nishinari K, de Melo Galvão Filho M, Wolosker AM. Aneurysm of superior mesenteric vein: Case report with 5-year follow-up and review of the literature. J Vasc Surg 2004;39:459-61.
4Smith TJ, Morehouse DL. Superior mesenteric vein aneurysm rupture. Vasc Endovascular Surg 2011;45:559-60.
5Vermeer NC, Elshof JW, Vriens PW. Clinical presentation, diagnosis, and treatment of venous aneurysms. J Vasc Surg Venous Lymphat Disord 2014;2:349-53.e3.
6Ahmed O, Ohman JW, Vachharajani N, Yano M, Sanford DE, Hammill C, et al. Feasibility and safety of non-operative management of portal vein aneurysms: A thirty-five year experience. HPB (Oxford) 2021;23:127-33.
7Rios A, Parsa P, Eidt J, Pearl G. A novel surgical approach to symptomatic left renal vein aneurysm. J Vasc Surg Venous Lymphat Disord 2017;5:875-7.
8Hechelhammer L, Crook DW, Widmer U, Wildermuth S, Pfammatter T. Thrombosis of a superior mesenteric vein aneurysm: Transarterial thrombolysis and transhepatic aspiration thrombectomy. Cardiovasc Intervent Radiol 2004;27:551-5.