Splanchnic Artery Aneurysms Katherine B Harrington Vascular Surgery

Splanchnic Artery Aneurysms Katherine B. Harrington Vascular Surgery Conference May 15, 2006

Splanchnic Artery Aneurysms • Uncommon, but clinically important • 22% present emergently, with an overall mortality of 8. 5%. • Incidence is increasing as imaging improves, but distribution is constant. • One-third will have associated nonvisceral aneurysms as well- aortic, renal, iliac, lower extremity, and cerebral.

Splanchnic Aneurysm Treatment • Although noninvasive imaging is improving, selective arteriography is the mainstay for planning therapy. • Surgery is still considered the gold standard especially for emergent rupture but both prophalactic and post-rupture catheterization are gaining in popularity. • Consistent long term results are lacking e. g: -Study 1: 92% early success rate, 4% mortality at 1 month, and only 1 recurrence at 4 years. vs. -Study 2: 57% early success rate, convert to open in 20%. • Catheter based interventions more appropriate for those aneurysms involving solid organs, e. g. those embedded in hepatic or pancreatic tissue with well formed collaterals.

Splenic Artery Aneurysms • Incidence: -Necropsy series vary between 0. 098% to 10. 4%. -0. 78% on review of abdominal arteriographic studies. -Female to male ratio of 4: 1. • Pathophysiology: -Saccular macroaneurysms secondary to acquired derangements of vessel wall: elastic fiber fragmentation, loss of smooth muscle, and internal elastic lamina disruption. -Occur most often at bifurcations. -Multiple in 20% of patients.

Splenic Aneurysms: Risk Factors • Fibromuscular Dysplasia: – Those with renal dysplasia are 6 x more likely to have splenic aneurysm. • Portal Hypertension with Splenomeglay: – Splenic Aneurysms found in 10 -30% of patients. – Often multiple aneurysms. • Multiple Pregnancies: – 40 -45% of female patients in case series were grand multiparous – Thought to be secondary to both hormonal effects and increased splenic arteriovenous shunting during pregnancy. • Other: – Nearby inflammation: e. g. chronic pancreatitis -> false aneurysms. – Mycotic aneurysms from endocarditis from IVDA. – Trauma.

Splenic Aneurysms: Presentation • History: – 17 -20% symptomatic with vague LUQ pain with occasional radiation. – 3 -9. 6% Rupture: Normally bleeds into lesser sac with CV collapse. • 25% of ruptures get “Double rupture phenomenon” when blood escapes lesser sac confinement. Provides window for treatment. • Ruptures can also present as GI bleeding or arteriovenous fistulas. • Exam: -- Bruit rare. – Normally under 2 cm, so rarely palpable pulsatile mass. • Imaging/Labs: – Often found incidentally with CT/MRI/Arteriography. – 70% will have curvilinear, signet ring calcification on Xray. – MMP-9 for monitoring progression.

Splenic Aneurysm: Treatment Indications • Indications for Treatment: – – Symptomatic Aneurysms > 2 cm. OLT patients: mortality post rupture >50%. Pregnant patients or those who want to conceive: • Maternal mortality post rupture – 70%, fetus- 75%. • Not associated with increased risk for rupture: – Calcifications – Age >60 – Hypertension.

Splenic Aneurysms: Treatment Options • Aneurysmectomy, Aneursymorraphy, Simple ligationexclusion without arterial reconstruction. Restoration of splenic artery continuity is rarely indicated. • Endovascular Coiling-still with unsure failure rates, risk of splenic infarction. • Stent Grafting- rare when splenic flow is needed for otheraputic reason like mesocaval shunting.

Splenic Aneurysm: Treatment • Proximal Aneurysms: – – Excise Gastrohepatic ligament. Expose through lesser sac. Ligate entering and exiting vessels. Those not embedded in pancreatic tissue are excised. • Mid-Splenic Aneurysms: – Generally associated with pancreatitis- generally false aneurysms. – Clamp proximal splenic artery. – Ligate arteries with prolene from within aneurysmal sac to reduce infection. – Placement of external drains in associated psuedocysts. – May need distal pancreatectomy. • Peri-Hilar: – Conventionally treated by splenectomy. – Now simple suture obliteration, aneurysmorraphy, or excision recommended.

Hepatic Artery Aneurysms • Incidence: – 20% of splanchnic aneurysms. – 1/3 associated with splenic aneurysms. – Male: Female 2: 1. – Most common in patients in their 50 s. – Normally solitary – Average >3. 5 cm. Those >2 cm tend to be saccular. – 80% Extrahepatic, 20% intrahepatic. • Common hepatic: 63% • Right hepatic: 28% • Left Hepatic 5% • Right and Left hepatic: 4%.

Hepatic Artery Aneurysms • Etiology: – Medial degeneration- 24%. – False aneurysms secondary to trauma- 22% – Infectious (IVDA)- 10% – Oral amphetamine use- ? – Periarterial inflammation, e. g. cholecystitis or pancreatitis- rare.

Hepatic Aneurysms: Presentation • Most likely asymptomatic. • Can present as RUQ or epigastric pain +/- radiation to the back not associated with meals. • Manifest as extrahepatic bile duct obstruction when large aneurysms compress biliary tree. • Pulsatile masses and bruits rare. • Rupture risk ~20 -44%. Mortality > 35%. • Rupture: into hepatobiliary tract and peritoneal cavity with equal frequency. – Rupture into bile ducts produces hematobilia- colic pain, massive GI bleeding with hematemesis, jaundice, and fevers are common. More common with traumatic intrahepatic false aneurysms. – Rupture into peritoneal cavity produced acute abdomen, CV colapse. More likely in PAN associated aneurysms.

Hepatic Aneurysms: Treatment • Common Hepatic Artery: – Extensive collaterals allow aneurysmectomy or exclusion without reconstruction. – However, 5 minute occlusion trial recommended to confirm flow to prevent necrosis. – Those with already existing parenchymal disease may need reconstruction.

Hepatic Aneurysms: Treatment • Proper Hepatic Artery and Extrahepatic branches: – Requires revascularization. – Subcostal or vertical midline incision. – Care should be taken to avoid common bile duct injury near the proximal hepatic artery near the gastroduodenal artery and pancreaticoduodenal artery.

Hepatic Aneurysm: Repair options • Aneurysmorrhaphy with or without vein patch closure, especially for traumatic false aneurysms. • Resection and reconstruction for fusiform or saccular with interpostion grafts using autogenous saphenous vein. Use spatulation of the artery and vein graft to produce ovoid anastomoses. • Aortohepatic bypass when interpostion not possible: – Extended Kocher manuver, medial viseral rotation. – Vein graft from aorta behind duodenum to porta hepatis. – Spatulated vein to artery with end-to-end anastomosis. • Liver parenchymal resection for intrahepatic aneurysms nonamenable to resection. • Endovascular coiling especially for traumatic- but with 42% recanulization reported.

Superior Mesenteric Artery Aneurysms • • 5. 5% of all splanchnic aneurysms. Affects men and women equally. Affects the first 5 cm of the SMA. Most often infectious in etiology: Nonhemolytic Streprelated to Left sided endocarditis. • Dissecting aneurysms are rare, but more common than in other visceral aneurysms. • Trauma- rare cause.

SMA Aneurysm: Presentation • Most are symptomatic • Intermittent upper abdominal pain progressing to constant epigastric pain. • Half of patients have a tender pulsatile mass that is not rigidly fixed. • Dissection or propagation cause intestinal angina. • 40% Rupture rate.

SMA Aneurysm: Treatment • Aneursymorrhaphy or simple ligation without reconstruction is acceptible, but try temporary occlusion of SMA with assesment of bowel viability. • Aneursymectomy hazardous secondary to surrounding SMV and pancreas. • Distal lesions through transmesenteric route. Proximal lesions visualized through retroperitoneal. • Interpostition graft or aortomesenteric bypass after exclusion is rarely accomplished/done. • Transcatherter occulsion used, but stent-grafts generally not favored secondary to high infectious etiology percentage.

Celiac Artery Aneurysms • Equal sex predilection. 50’s. • Mostly medial degeneration related. Trauma and infection rare. • Most are asymptomatic. • Bruits heard frequently, and palpable puslatile mass in 30%. • Risk of rupture 13%. Normally intraperitoneal.

Celiac Aneurysms: Treatment • Aneursymectomy with aortoceliac bypass with graft originating from supraceliac aorta, or aneurysmectomy with primary reanastomosis. • OR celiac axis ligation. Do not use with liver dx. • Abdominal route, medial visceral rotation, transection of crus and median arcuate ligament to expose celiac. If celiac is particularly large may need a thoracoabdominal approach.

Gastric and Gastroepiploic Aneurysms • Likely etiology medial degeneration. • Often solitary • Gastric artery aneurysms are 10 x more common than gastroepiploic. • Men: Women 3: 1. 50 s and 60 s. • Over 90% present as ruptures with 70% with serious GI bleeding. Very few admit to preceding symptomatology.

Gastric and Gastroepiploic Aneurysms- Treatment • Treatment directed at stopping the hemorrhage- approximately 70% mortality post-rupture. • Ligation with or without excision of aneurysm is appropriate for extraintestinal lesions. • Intramural aneurysms and those bleeding into the GI tract should be excised with the portions of associated gastric tissue.

Jejunal, Ileal, and Colic Aneurysms

Jejunal, Ileal, and Colic Aneurysms • • Pathogenesis poorly understood. Equal sex distribution. 60 s. Most are solitary, mms to 1 cm. Multiple lesions seen with immunologic injury, septic emboli, or necrotizing vasculitides. • Rarely symptomatic. • Jejunal rupture rare, colic rupture more common. • 20% rupture mortality.

Jejunal, Ileal, and Colic Aneurysms: Treatment • Arterial ligation, aneurysmectomy, and resection of affected bowel if blood supply is compromised.

Gastroduodenal, Pancreaticoduodenal, and Pancreatic Aneurysms • Gastroduodenal aneurysms are 1. 5% of splanchnic aneurysms and pancreaticoduodenal and pancreatic are 2%. • Men: Female is 4: 1. • Etiology: Periarterial inflammation, actual vascular necrosis, and erosion by expanding pancreatic psuedocysts. False aneurysms more common. • 60% present as rupture, with a 49% mortality. • Most are symptomatic with epigastric pain radiating to back, because most are pancreatitis related. • 75% tend to have GI bleeding into stomach or duodenum.

Gastroduodenal, Pancreaticoduodenal, and Pancreatic Aneurysms • Treatment: Pancreaticoduodenal and pancreatic artery aneurysms are more difficult to treat secondary to their small size and being embedded in the pancreas. Intraoperative arteriography is useful. • Suture ligature of entering and exiting vessels without extra-aneurysmal dissection is appropriate. • Those involving pancreatic tissue should place appropriate drains and/or resection pancreatic tissue as needed. • Transcatheter embolization has been described, but may only serve as a temporizing step. • Stent-grafting of the SMA which occludes the pancreaticoduodenal has also been described.