Splenic artery embolization

Liu PP, Lee WC, Cheng YF, et al. (2004) Use of splenic artery embolization as an adjunct to nonsurgical management of blunt splenic injury. J Trauma 56 768-772... 

Mazer M, Smith CW, Martin VN (1985) Distal splenic artery embolization with a flow-directed balloon catheter. Radiology 1541 245... 

An alternative to superselective catheterization of splenic artery branches is the use of proximal splenic artery embolization [23, 33, 39]. In this technique, the main splenic artery is embolized. 

Haan et al. also reported the results of a multicenter review of patients undergoing splenic artery embolization for splenic trauma and this represents the largest collection of splenic artery embolization patients studied to date [2]. In this review, 140 patients undergoing splenic artery embolization at... 

Haan et al. further explored the CT finding of air within areas of infarction after splenic artery embolization [45]. They found that air in areas of splenic infarction was associated with infection in only 17% of patients but that this rate increased to 33% in symptomatic patients [45]. Clearly, this implies that air is not pathognomonic of infection and that further investigation must be performed in these patients prior to splenectomy. While asymptomatic patients can likely be observed, patients with symptoms and a minimal amount of air should be treated with antipyretics. Aspiration and percutaneous drainage should be considered, as should splenectomy, in patients with large areas of infarct air and/or severe symptoms [45]. 

During the past three decades, splenic arterial embolization has been advocated in the nonoperative treatment of patients with these difficult clinical scenarios by intentionally infarcting splenic tissue and reducing its consumptive activity. In 1973, Maddison [97] reported the initial clinical experience of splenic artery embolization, but severe complications that resulted from complete splenic infarction prevented acceptance of the technique as a viable treatment option. Since this initial descrip-... 

Similar to complete splenic arterial embolization, PSE is prone to complications and adverse effects, but PSE is much better tolerated than complete splenic ablation. In addition to those mentioned above, patients might develop pancreatitis (likely a result of nontarget embolization of dorsal pancreatic and pancreatic magna arteries), pleural effusions requiring thoracentesis, paralytic ileus, or the post-embolization syndrome consisting of fever, leukocytosis, and abdominal pain [119]. 

Gardner RV, Warrier RP, Loe W, Ward K, Haymon M, Graver R (2003) Splenic artery embolization as emergency treatment of splenic rupture in a child with T-cell acute lymphocytic leukemia having t(8 14) translocation. Med Pediatr Oncol 41 492-493... 

Poulin EC,Mamazza J,SchlachtaCM (1998) Splenic artery embolization before laparoscopic splenectomy. An update. Surg Endosc 12 870-875... 

Emboli. Embolic phenomena occur in up to one-third of cases and may result in significant complications. Left-sided endocarditis can result in renal artery emboli causing flank pain with hematuria, splenic artery emboli causing abdominal pain, and cerebral emboli, which may result in hemiplegia or alteration in mental status. Right-sided endocarditis may result in pulmonary emboli, causing pleuritic pain with hemoptysis. 

In splenic trauma, with a life-long increased risk of sepsis after splenectomy, non-operative treatment is the management of choice. In several studies the efficacy of TAE has been shown to be over 90% (Hagiwara et al. 1996). Embolization of the splenic artery, distal to the pancreatic artery, leads to splenic preservation resulting from collateriza-tion by pancreatic and gastric branches. 

A spectrum of end-organ ischemic complications can occur with embolotherapy. Bowel infarction can complicate splanchnic embolization targeting bleeding or could result from inadvertent non-target embolization from an upstream source [88]. Gallbladder infarction or bile duct necrosis can complicate hepatic artery embolization or che-moembolization [89, 90]. Splenic abscess and overwhelming sepsis can occurs following splenic embolization [91]. Skin necrosis and nerve injury have been reported as a result of ethanol embolization of vascular malformations [53, 54]. Buttock muscular necrosis, buttock claudication and sexual dysfunction can occur as a result of internal iliac branch embolization, especially when distal or bilateral [92-95]. 

Ishimaru H, Murakami T, Matsuoka Y, et al. (2004) N-butyl 2-cyanoacrylate injection via pancreatic collaterals to occlude splenic artery distal to large splenic aneurysm after proximal coil embolization. AJR Am J Roentgenol 182 213-215... 

It should also be noted that when larger vessels are occluded with coils, collateral arteries form relatively rapidly and the distal vascular bed is still perfused but at a lower pressure than before the embolization. This is the theory behind the proximal occlusion of the splenic artery to halt splenic hemorrhage. The use of these coils presupposes the existence of collaterals. For example, embolization of the renal artery will most likely not result in viable renal tissue as the kidney is an end-organ and will not have a collateral arterial system that will support the kidney. 

Fig.7.7a,b. Front and back door embolization of a splenic artery pseudoaneurysm (a) secondary to acute on chronic pancreatitis with a good result (b). This patient is alive and well with no recurrence at 52 months... 

Fig 4.1. a Selective splenic angiogram demonstrating a pseudoaneurysm arising from an upper pole branch after blunt trauma, b Selective splenic angiogram after coil embolization of the upper pole branch of the splenic artery supplying the injured splenic parenchyma... 

Proximal Embolization In the absence of active contrast extravasation, the splenic artery is proximally embolized. We typically utilize either a 5F Cobra catheter or a 5F Omni-2 catheter to catheterize the celiac axis. Depending on the tortuosity of the vessel, we then either use the Cobra catheter or a microcatheter with a 0.021 inner luminal diameter for more selective catheterization. Once the catheter is in place, just distal to the dorsal pancreatic artery, coils are deposited. The size of the coils chosen depends on the size of the vessel. 

Hagiwara A, Yukioka T, Ohta S et al. (1996) Nonsurgical management of patients with blunt splenic injury efficacy of transcatheter arterial embolization. Am J Roentgenol 167 159-166... 

James CA, Emanuel PG, Vasquez WD et al. (1996) Embolization of splenic artery branch pseudoaneurysms after blunt abdominal trauma. J Trauma 40 835-837... 

The splenic artery arises from the celiac axis and is often tortuous. Therefore, glide wires and hydrophilic catheters are helpful in gaining peripheral access to this vessel. It has a long course from the aorta to the splenic hilum, making it one of the most amenable arteries for stent graft placement. It supplies branches to the body and tail of the pancreas. If necessary, complete occlusion of the main splenic artery distal and proximal to the aneurysm neck can be performed. If the artery is completely thrombosed, collaterals can be parasitized resulting in a splenic remnant or even hypertrophy of splenules after an embolization. 

Typically a groin approach is used and the celiac axis is selected with a Sos catheter. Selective angiography is performed to lay out the splenic artery. A glidewire is then passed distally and either the Sos or a Cobra catheter is advanced. Embolization can be performed through the 5 French catheter at this point. If too tortuous, then a microcatheter can be passed coaxially. (Fig. 8.4) We use either a Mass Transit (Cordis, Miami, FL) or Renegade (Boston Scientific, Boston, MA) microcatheter. These catheters can withstand a power injection of 2-3 cc per second if needed. 

Fig. 8.4. a Nonselective celiac angiogram in a patient with a large splenic pseudoaneurysm after trauma. Note the marked vasospasm and contrast pooling in the left upper quadrant, b Coaxial use of a microcatheter to obtain access distal to the neck of the pseudoaneurysm despite the vasospasm, c Follow-up splenic angiogram after coil embolization of the splenic artery. No further contrast extravasation was noted and the patient s vitals stabilized. (Courtesy of James R. Duncan, MD)... 

Complications of the embolization procedure include those of diagnostic angiography with the addition of aneurysm rupture, nontarget embolization, splenic infarction, abscess formation, and rarely sepsis (Fig. 8.5). Total splenic infarction can occur, which puts the patient at an increased risk of infection with encapsulated bacteria such as pneumococcus. Older literature suggests that bland splenic artery aneurysms rupture at a rate of approximately 2% [30]. However, in pregnant patients, rupture occurs in nearly every case with mortality rates for mother and fetus 70% and 95% respectively [31]. Obviously, any aneurysm in the pregnant female should be addressed since over 95% will rupture if left untreated [30, 32]. 

Fig. 8.5. a CT of the same patient from Figure 4 demonstrating a perisplenic abscess. The patient developed fever and an elevated white cell count one week after embolization. Note arterial perfusion of a splenic remnant medial to the abscess, b CT image inferior to that of a demonstrating the coils near the splenic hilum. Collateral flow to the spleen despite complete occlusion of the splenic artery exists, c Inferior aspect of the abscess distinguishing kidney from the residual spleen. (Courtesy of James R. Duncan, MD)... 

PSE refers to partial obliteration of the peripheral intrasplenic vascular bed by injection of embolic material through the angiographic catheter placed within the splenic artery. This technique evolved as initial attempts to treat hypersplenism by proximal splenic arterial occlusion proved unsuccessful. Response failure was attributed to the abundant... 

PSE can be performed by two methods. In one approach, a few distal branches of the splenic artery are selectively catheterized and embolized to complete stasis, and several other branches are... 

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