(1) Early image from the IMV showing the shunt and the renal vein. (2) Later image from the IMV showing the shunt and renal vein. (3) Coiled shunt and the thrombosed IMV which shut down as soon as the shunt was closed.
Original Post, lightly edited for flow:
(1) Early image from the IMV showing the shunt and the renal vein. (2) Later image from the IMV showing the shunt and renal vein. (3) Coiled shunt and the thrombosed IMV which shut down as soon as the shunt was closed.
The patient is a 66-year-old female with well-preserved hepatic synthetic function and no hepatic varices, and I have been asked by the gastroenterology service to embolize her portosystemic shunt to improve overall hepatic encephalopathy control. She has a history of well-controlled encephalopathy on lactulose with some breakthrough symptoms requiring hospitalization. We are unsure if her previous breakthrough symptoms are due to noncompliance or concurrent infection, such as a UTI. Our potential embolization approach would be transvenous to close the “back door” of the system with a vascular plug in the patient’s gonadal vein just below the left renal vein. Alternatively, we could perform transhepatic approach and embolize the IMV at its anastomosis with the gonadal vein. Does anyone favor one approach over the other, and if so, why?
What is your current practice preference for inferior mesenteric vein to gonadal vein shunt?
My preference for approaching portosystemic shunt treatment is transhepatic or transsplenic access.
What challenges have you faced in evaluating patients who require portosystemic shunt embolization?
Problems include underlying poor general medical condition, subjectivity, variability of symptoms of encephalopathy, and difficulty in determining compliance with medical therapy. The access can be challenging with poor visualization in cirrhotic, fatty liver and obese patients. The shunts can be difficult to access with tortuous, stenotic veins. If technically difficult, the cases can be long and therefore challenging for conscious sedation.
What is your preferred approach in embolizing portosystemic shunts?
I prefer a transhepatic approach guided by ultrasound with a 6F destination sheath and AMPLATZER Vascular Plugs.
Is there a role for collaboration between gastroenterology and IR for embolization?
Definitely. It is important for GI and hepatology to be aware that we can do these procedures and to refer patients for consultation who might benefit from IR. Also, they need to follow the patients for new or worsening varices after the procedure, so we all need to be on the same page.
What specifically prompted you to reach out regarding this case?
Because of the large size of the shunt, I was tempted to think I could treat this from a femoral approach, although I suspected that the tortuous multistenotic vein would be difficult to catheterize and that going against the flow would make visualization difficult.
What SIR Connect posts were most valuable to you and why?
Most of the respondents believed that transhepatic was the way to go, which gave me confidence in my plan. Also, the post urging caution from Peter Bream, MD, FSIR, was prescient, as the veins can be fragile. Even with that warning, I did cause a self-limited retroperitoneal hematoma that was very stressful to observe.
Did the patient’s retroperitoneal hematoma occur during the case or immediately afterwards? How was this managed or monitored?
The retroperitoneal hematoma occurred right at the end of the case. The patient began to complain of abdominal and back pain. They were taken to CT from the IR suite where a moderate hematoma without extravasation was evident. The patient was treated conservatively, monitoring vital signs and complete blood counts. There was a drop in the patient’s hemoglobin, but this did not clinically require transfusion and the patient’s symptoms resolved overnight.
Will you, or have you, changed your practice patterns on the basis of responses on SIR Connect? Please describe any changes you are considering.
I think there are subtle changes in practice based on other people’s experiences, especially for uncommon scenarios where my partners and I do not have a lot of shared experience. Tips and tricks that others have learned, including cautions based on past complications, all help to avoid tunnel vision when planning a case. This helps to enhance preparedness, instill confidence and decrease stress, all of which benefit me and my patient.
Additional commentary:
Portosystemic shunt embolization is typically indicated in the nonacute primary and secondary prevention setting of variceal hemorrhage and shunt-type portosystemic encephalopathy.1 Occlusion of the pathological upstream shunts using balloon-occluded retrograde transvenous obliteration (BRTO) and, more recently, plug- or coil-assisted retrograde transvenous obliteration (PARTO or CARTO, respectively), are safe and clinically effective interventions.1–4
Transvenous obliteration via the internal jugular or femoral veins can be performed with technical success in the treatment of gastroesophageal and ectopic varices in addition to simple shunts. 1–4 A transhepatic approach with direct injection and targeted embolization of the shunt’s tributaries may be useful when anatomy is not delineated clearly or with more complex shunts having difficult, tortuous access like this case.4 Pre-procedure imaging with CT, MRA or MRV is essential to evaluate the portal vein, extent of the shunt and its inflow, and the presence of collateral veins.1 Potential complications of transhepatic approach are well described and similar to that of other percutaneous transhepatic procedures, such as portal vein embolization, transient hemobilia, bleeding (subcapsular hematoma) and infection.5 Choice of access size, embolic agent and stability of the embolic agent in vein are also overall important periprocedural considerations.4 For example, the advantages of Amplatzer Vascular Plug or coil approach with a Gelfoam slurry include a lack of balloon or sclerosant requirement, which is a one-time procedure for the patient and entails a lesser need for collateral vein embolization.1,2
In choosing a particular approach as an interventional radiologist, the focus is on collaboration, risks and deciding which patients would most benefit from embolization.6,7 For portal hypertension in the setting of liver disease, patients referred to multidisciplinary teams including gastroenterology, diagnostic and interventional radiology, general surgery, and pathology have been shown in a prospective study to have positive outcomes and a significantly lower risk for gastroesophageal variceal rebleed.6 Additionally, a large, retrospective multicenter survey on safety and efficacy of embolization of large portosystemic shunts for refractory hepatic encephalopathy demonstrated that the MELD score was a positive predictor value for hepatic encephalopathy recurrence and that the effect of embolization appeared to be irrespective of the type of shunt.7 These collaborations and tools are invaluable in improving periprocedural outcomes for our patients as IRs.
As pointed out in this discussion, a complicated patient such as the one presented here reminds us that IR operates best in a joint, collaborative fashion with our clinical peers and IR colleagues. Even experienced IRs rely on pre-procedural review of a case with their colleagues to help ensure they have considered all the potential approaches to treat their patients safely and successfully.
References
- Kandarpa K, Hendricks N.J, Haskal Z.J. Balloon-occluded retrograde transvenous obliteration. Handbook of Interventional Radiologic Procedures. Lippincott Williams & Wilkins. 2016;407–412.
- Gwon D.I, Gi-Young K, Hyun-Ki Y, Kyu-Bo S, Jin Hyoung K, Ji Hoon S, Heung Kyu K, Ho-Young S. Gastric varices and hepatic encephalopathy: Treatment with vascular plug and gelatin sponge–assisted retrograde transvenous obliteration—A primary report. 2013;268(1): 281–87.
- Lee E.W, Saab S, Gomes A.S, Busuttil R, McWilliams J, Durazo F, Han S, et al. Coil-assisted retrograde transvenous obliteration (CARTO) for the treatment of portal hypertensive variceal bleeding: Preliminary results. Clin Transl Gastroenterol. 2014;5(10):e61.
- Lynn AM, Singh S, Congly SE, Khemani D, Johnson DH, Wiesner RH, Kamath PS, Andrews JC, and Leise MD. Embolization of portosystemic shunts for treatment of medically refractory hepatic encephalopathy. Liver Transplant. 2016;22(6):723–31.
- Madoff DC, Hicks ME, Vauthey J, Charnsangavej C, Morello FA, Ahrar M, Wallace MJ, Gupta S. Transhepatic portal vein embolization: Anatomy, indications, and technical considerations. 2002;22(5): 1063–76.
- Tseng Y, Ma L, Lv M, Luo T, Liu C, Wei Y, Liu C, et al. The role of a multidisciplinary team in the management of portal hypertension. BMC Gastroenterology. 2020;20(1);83.
- Laleman W, Simon-Talero M, Maleux G, Perez M, Ameloot K, Soriano G, Villalba J, et al. Embolization of large spontaneous portosystemic shunts for refractory hepatic encephalopathy: A multicenter survey on safety and efficacy. 2013;57(6): 2448–57.
Disclaimer: This column represents the work and opinions of the contributing authors and do not necessarily reflect the views or policies of SIR. SIR assumes no liability, legal, financial or otherwise, for the accuracy of information in this article or the manner in which it is used. The statements made in the column are not intended to set a standard of care and should not be treated as medical advice nor as a substitute for independent, professional judgment.
