Endovascular Management of Acquired Hepatic Arterial-Portal Venous Malformations.

PURPOSE: Arteriovenous malformations (AVMs) are typically congenital in origin, but acquired types, such as dural arteriovenous fistula (AVF), have been described. This study aimed to describe the diagnosis and endovascular treatment of acquired hepatic arterial-portal venous (HA-PV) malformations. MATERIALS AND METHODS: A retrospective review of suspected acquired HA-PV malformations from 9/2011 to 2/2018 was performed. Eight patients (1M:7F, average age 62) with HA-PV malformations were identified. Four (50%) patients had a history of liver transplant. All HA-PV malformations were Yakes type IIIA (multiple inflow arteries with a single vein outflow and with the nidus located within the vein wall). In all cases, computed tomography angiography/magnetic resonance angiography was unable to distinguish AVMs from AVFs, and a wrong diagnosis was made in each instance. RESULTS: Review of pre-procedural Doppler ultrasounds in all cases demonstrated arterialization of portal vein waveforms. Review of pre-procedural cross-sectional (CT/MR) imaging in all of these cases demonstrates a network of arteries around the portal vein with early portal vein filling in every instance. Attempts to close the shunts via arterial inflow embolization but without venous nidus occlusion were performed and were unsuccessful in five out of eight (62.5%) cases. All curative therapies were via embolization of the outflow vein (segmental or lobar portal vein). Technical success was seen in seven of eight cases (87.5%), while one patient is planned to receive additional nidal vein embolization. Liver function was preserved after treatment without worsening of bilirubin or albumin levels. CONCLUSION: The diagnosis of an acquired HA-PV malformation can guide curative endovascular treatment by embolization of the portal vein outflow.

Air Embolism During TEVAR: Liquid Perfluorocarbon Absorbs Carbon Dioxide in a Combined Flushing Technique and Decreases the Amount of Gas Released From Thoracic Stent-Grafts During Deployment in an Experimental Setting.

PURPOSE: To investigate the influence of flushing thoracic stent-grafts with carbon dioxide and perfluorocarbon on the amount of gas released during stent-graft deployment in thoracic endovascular aortic repair (TEVAR). MATERIALS AND METHODS: Ten TX2 ProForm thoracic stent-grafts were deployed into a water-filled container with a curved plastic pipe and flushed sequentially with carbon dioxide, 20 mL of liquid perfluorocarbon (PFC), and 60 mL of saline. Released gas was measured using a calibrated setup. The volume of released gas was compared with the results of an earlier published reference group, in which identical stent-grafts were flushed with 60 mL saline alone as recommended in the instructions for use. RESULTS: The average amount of gas released in the test group was 0.076 mL, significantly lower (p<0.001) than the mean 0.79 mL of gas released in the reference group. Big bubbles appearing at the tip of the sheath when deployment was started were seen in all grafts of the reference group but in only 2 of the test group stent-grafts. Small bubbles were less frequent in the test group. CONCLUSION: The amount of gas released from thoracic stent-grafts during deployment can be influenced by different flushing techniques. The use of PFC in addition to the carbon dioxide flushing technique reduces the volume of gas released during deployment of tubular thoracic stent-grafts to a few microliters. This significant effect is presumably based on the high solubility of carbon dioxide in perfluorocarbon and could be a potential future approach to lower the risk of cerebral injury and stroke from air embolism during TEVAR.

Retrograde Stenting Under Transmesenteric Angiographic Guidance of an Occluded Superior Mesenteric Vein to Treat Life-Threatening Hemorrhage.

Midgut carcinoid tumors (MCTs) are responsible for a range of mesenteric vascular complications and may rarely manifest with gastrointestinal (GI) hemorrhage. Endovascular approaches are particularly useful for this population, as surgery is often technically difficult. We report a case of life-threatening upper GI bleeding in a 50-year-old man previously diagnosed with an MCT in the small bowel mesentery. Computed tomography angiogram revealed an MCT obstructing the superior mesenteric vein (SMV) associated with multiple large collateral vessels. The patient underwent retrograde stenting of the obstructed SMV using a combined open and endovascular approach to successfully terminate the persistent GI bleeding.

Results of complex aortic stent grafting of abdominal aortic aneurysms stratified according to the proximal landing zone using the Society for Vascular Surgery classification.

BACKGROUND: Advances in endovascular technology have led to the successful treatment of complex abdominal aortic aneurysms. However, there is currently no consensus on what constitutes a juxtarenal, pararenal, or suprarenal aneurysm. There is emerging evidence that the extent of the aneurysm repair is associated with outcome. We compare the outcomes of 150 consecutive patients treated with a fenestrated or branched stent graft and present the data stratified according to the Society for Vascular Surgery classification based on proximal anatomic landing zones. METHODS: A prospectively collected database of consecutive patients undergoing fenestrated or branched stent graft insertion in a tertiary center between 2008 and 2013 was retrospectively analyzed. Aneurysms were subdivided into zones according to where the area of proximal seal could be achieved in relation to the visceral arteries. Zone 8 covers the renal arteries, zone 7 covers the superior mesenteric artery, and zone 6 covers the celiac axis. Patient demographics, operative variables, mortality, and major morbidity were analyzed by univariate and multivariate analysis to assess for differences between zones. RESULTS: During the study period, 150 patients were treated. There were 49 in zone 8, 76 in zone 7, and 25 in zone 6. Prior aortic surgery had been performed in 19 patients, which included 11 patients with previous endovascular aneurysm repairs. There was significantly increased blood loss (P < .001), operative time (P < .0001), total hospital stay (P = .018), and intensive care unit stay (P < .0001) as the zones ascended the aorta. There were 14 inpatient deaths recorded across all zones with a 30-day mortality rate of 8%. Logistic regression analysis for 30 day mortality showed a significant increase as the zones ascended (P = .007). Kaplan-Meier analysis showed that 5-year survival significantly deteriorated as the zones ascended (P = .039), with no significant difference in the freedom from reintervention curves between zones (P = .37). CONCLUSIONS: We have shown that the extent of the aneurysm repair as determined by the proximal sealing zone is associated with outcome. Mortality, operative duration, blood loss, and hospital stay all significantly increased as the zones ascended. These data also validate the use of the proposed new classification based on aortic anatomy.

Temporary Perfusion Branches to Decrease Spinal Cord Ischemia in the Endovascular Treatment of Thoraco-Abdominal Aortic Aneurysms: Based on a Presentation at the 2013 VEITH Symposium, November 19-23, 2013 (New York, NY, USA).

BACKGROUND: Spinal cord ischemia (SCI) is one of the most feared complications following the repair of thoraco- abdominal aortic aneurysms (TAAA). Endovascular repair of TAAA is now possible with branched stent grafts, but spinal cord ischaemia rates are still unacceptably high. A number of techniques have been utilized to reduce these levels, however, SCI remains a challenge to endovascular repair of TAAA. The use of sac perfusion branches aims to reduce the incidence of this catastrophic complication. METHODS: A retrospective analysis of all patients undergoing branched endovascular aortic repair for all thoraco-abdominal aneurysms (TAAA) using custom made devices during January 2008 to August 2014. We describe a two staged technique in which perfusion of segmental vessels is maintained by a temporary endoleak through an open perfusion branch, incorporated within the branched stent graft, followed by a closure of this branch at a later date to complete exclusion of the aneurysm. RESULTS: Forty-seven patients underwent TAAA repair. Twenty-five (53%) had a two-stage procedure using either a sac perfusion branch or a target vessel to perfuse the sac. Nine patients (19.15%) suffered some form of SCI with eight patients having temporary SCI (lasting less than 72 hours) and one patient having permanent SCI. Of eight patients that had temporary spinal cord ischemia, all had a perfusion strategy. There was one case of permanent SCI (2.13%). CONCLUSION: Sac perfusion branches provide a safe method for preventing SCI, however this needs to be used in conjunction with controlling MAP and CSF drainage.

Endovascular treatment of mycotic aortic aneurysms: a European multicenter study.

BACKGROUND: Mycotic aortic aneurysm (MAA) is a rare and life-threatening disease. The aim of this European multicenter collaboration was to study the durability of endovascular aortic repair (EVAR) of MAA, by assessing late infection-related complications and long-term survival. METHODS AND RESULTS: All EVAR treated MAAs, between 1999 and 2013 at 16 European centers, were retrospectively reviewed. One hundred twenty-three patients with 130 MAAs were identified. Mean age was 69 years (range 39-86), 87 (71%) were men, 58 (47%) had immunodeficiency, and 47 (38%) presented with rupture. Anatomic locations were ascending/arch (n=4), descending (n=34), paravisceral (n=15), infrarenal aorta (n=63), and multiple (n=7). Treatments were thoracic EVAR (n=43), fenestrated/branched EVAR (n=9), and infrarenal EVAR (n=71). Antibiotic was administered for mean 30 weeks. Mean follow-up was 35 months (range 1 week to 149 months). Six patients (5%) were converted to open repair during follow-up. Survival was 91% (95% confidence interval, 86% to 96%), 75% (67% to 83%), 55% (44% to 66%), and 41% (28% to 54%) after 1, 12, 60, and 120 months, respectively. Infection-related death occurred in 23 patients (19%), 9 after discontinuation of antibiotic treatment. A Cox regression analysis demonstrated non-Salmonella-positive culture as predictors for late infection-related death. CONCLUSIONS: Endovascular treatment of MAA is feasible and for most patients a durable treatment option. Late infections do occur, are often lethal, and warrant long-term antibiotic treatment and follow-up. Patients with non-Salmonella-positive blood cultures were more likely to die from late infection.

Global experience with an inner branched arch endograft.

BACKGROUND: Branched endografts are a new option to treat arch aneurysm in high-risk patients. METHODS AND RESULTS: We performed a retrospective multicenter analysis of all patients with arch aneurysms treated with a new branched endograft designed with 2 inner branches to perfuse the supra aortic trunks. Thirty-eight patients were included. The median age was 71 years (range, 64-74 years). An American Society of Anesthesiologists score of 3 or 4 was reported in 89.5% (95% confidence interval [CI], 79.7-99.3) of patients. The 30-day mortality rate was 13.2% (95% CI, 2.2-24.2). Technical success was obtained in 32 patients (84.2% [95% CI, 72.4-95.9]). Early secondary procedures were performed in 4 patients (10.5% [95% CI, 0.7-20.3]). Early cerebrovascular complications were diagnosed in 6 patients (15.8% [95% CI, 4.0-27.6]), including 4 transient ischemic attacks, 1 stroke, and 1 subarachnoid hemorrhage. The median follow-up was 12 months (range, 6-12 months). During follow-up, no aneurysm-related death was detected. Secondary procedures during follow-up were performed in 3 patients (9.1% [95% CI, 0.0-19.1]), including 1 conversion to open surgery. We compared the first 10 patients (early experience group) with the subsequent 28 patients. Intraoperative complications and secondary procedures were significantly higher in the early experience group. Although not statistically significant, the early mortality was higher in the early experience group (30% [95% CI, 0.0-60.0]) versus the remainder (7.1% [95% CI, 0.0-16.9]; P=.066). Being part of the early experience group and ascending aortic diameter≥38 mm were found to be associated to higher rates of combined early mortality and neurologic complications. CONCLUSIONS: Our preliminary study confirms the feasibility and safety of the endovascular repair of arch aneurysms in selected patients who may not have other conventional options. CLINICAL TRIAL REGISTRATION INFORMATION: Thoracic IDE NCT00583817, FDA IDE# 000101.

Hemodynamics in rat liver tumor model during retrograde-outflow isolated hepatic perfusion with aspiration from the portal vein: angiography and in vivo microscopy.

BACKGROUND: Orthograde percutaneous isolated hepatic perfusion (IHP) techniques using balloon occlusion catheters are relatively simple and facilitate repeated therapy, but they result in higher rates of leakage from the perfusion circuit into the systemic circulation. Therefore, a feasible protocol for percutaneous IHP with less leakage is required. PURPOSE: To investigate hemodynamic changes in rat liver and tumor during retrograde-outflow isolated hepatic perfusion (R-IHP) with aspiration from the portal vein (PV). MATERIAL AND METHODS: Animal experiments were approved by the Animal Experiment Ethics Committee of Lund University. Eighteen rats underwent R-IHP after laparotomy and catheterization of the PV and hepatic artery (HA). The HA, inferior vena cava (IVC), and PV were ligated, and flow through the suprahepatic IVC was controlled with a suture loop. The rats were divided into two groups to examine blood flow during R-IHP. Four rats (group 1) underwent arteriography via the HA with and without R-IHP, and 14 rats (group 2) were inoculated with tumor and examined by in vivo fluorescence microscopy of liver and tumor during R-IHP. RESULTS: In group 1, hepatic arteriography during R-IHP confirmed arterioportal communication in all four rats, with the PV acting as an outflow tract. In vivo fluorescence microscopy in group 2 showed strong enhancement of tumors, and no blood supply from the portal venules to the tumors was seen in any of the 14 rats. Blood flow in the major portion of the hepatic lobules was stopped and the percentage of enhanced area was significantly lower in the normal hepatic lobules than in the tumors (P < 0.0001). CONCLUSION: We confirmed reversal of blood flow concomitant with good perfusion of the liver tumor and with reduced perfusion of normal liver parenchyma during R-IHP.

A new technique of branched stent graft treatment for ruptured thoracoabdominal aortic aneurysms.

Endovascular repair of thoracoabdominal aortic aneurysms (TAAAs) using a branched stent graft is a technically challenging procedure. A 64-year-old man with multiple medical problems, including severe renal impairment, is presented with a ruptured type IV TAAA. He underwent emergency repair using an off-the-shelf branched stent graft and carbon dioxide as the exclusive contrast agent.

Temporary axillobifemoral bypass during fenestrated aortic aneurysm repair.

OBJECTIVE: Fenestrated endovascular aortic aneurysm repair (f-EVAR) of juxtarenal aneurysms requiring cannulation of the superior mesenteric artery and renal arteries is technically challenging, has a long operating time, and requires bilateral large-caliber sheath insertion into the femoral arteries. Consequently, the risk of lower limb ischemia and subsequent reperfusion injury is increased. We describe the use of an adjunct temporary axillobifemoral bypass graft (TABFBG) for f-EVAR and propose that it be used as a strategy to avoid ischemia-reperfusion injury in patients anticipated as being at increased risk. METHODS: Consecutive patients from a tertiary referral center undergoing f-EVAR, between October 2008 and August 2011, were retrospectively analyzed. Patients with lower limb arterial occlusive disease and those with difficult anatomy had an adjunct TABFBG. RESULTS: All patients presenting with a juxtarenal aortic aneurysm were treated endovascularly, regardless of aneurysm anatomy and technical difficulties. There were 37 patients without TABFBG (group 1) and 27 with TABFBG (group 2). No patients required open conversion. Sex and age were not significantly different between the groups. The median ankle-brachial pressure index was significantly higher in group 1 (P=.0001). The groups had similar median blood loss, percentage of target vessel cannulation, and median stay in the intensive therapy unit. Morbidities were similar in both groups. There were no significant differences in cardiac, renal, or respiratory complications between the groups. The 30-day mortality was 10.8% (n=4) in group 1 and 0% in group 2 (P=.046). CONCLUSIONS: Our series has demonstrated a significant reduction in mortality (10.8% absolute risk reduction) and no increase in morbidity with the use of a TABFBG for fenestrated grafts. This is likely a result of the reduction in ischemia and ischemia-reperfusion injury in these patients. We therefore recommend the use of TABFBG in patients with proximal severe stenotic or occlusive disease and those in whom an operative time of >4 hours is predicted (typically those for whom three or more target fenestrations is planned).

Techniques for removing bilateral renal artery stents prior to fenestrated endovascular aneurysm repair.

PURPOSE: To demonstrate 2 endovascular methods for successful intravascular stent extraction. TECHNIQUE: In preparation for fenestrated endovascular aneurysm repair, renal artery stents may be implanted for focal vessel stenosis at the ostium. In a recent case, bilateral renal artery stents were deployed with >50% protruding into the aortic lumen, thus rendering fenestrated endografting impossible. Two techniques were employed to extract the stents. In the left renal artery, the stent was extracted using an endovascular snare, but the right renal artery stent could not be removed with this method. Instead, an endoscopic forceps was advanced down a 16-F sheath, and the stent was grasped, extracted, and released into the aneurysm sac. The endovascular repair then proceeded in the usual fashion. CONCLUSION: The need to remove a stent prior to endovascular aneurysm repair is not a common problem encountered by most endovascular specialists; however, these methods should be in their armamentarium should the need arise.

Elective sac perfusion to reduce the risk of neurologic events following endovascular repair of thoracoabdominal aneurysms.

Spinal cord ischemia (SCI) is a catastrophic complication of thoracoabdominal aortic aneurysm (TAAA) repair. This article describes our early experience with a technique for maintaining perfusion of segmental vessels (intercostals and lumbars) in the early postoperative period after endovascular repair of a TAAA, with "sac perfusion branches" added to custom-made stent grafts. These are closed 7 to 10 days after the first procedure to complete exclusion of the aneurysm. We have used this technique in 10 patients with type II TAAAs. One developed monoparesis of the right leg during a period of hypotension secondary to a cardiac event and died within 30 days. Two patients developed lower limb weakness after closure of the perfusion branches, both with full recovery. Controlled perfusion of segmental vessels with perfusion branches is feasible and may be a useful adjunct to prevent SCI, providing protection to spinal cord perfusion during the immediate postoperative period when risk of SCI is greatest.

Placement of a branched stent graft into the false lumen of a chronic type B aortic dissection.

The treatment of chronic type B aortic dissections remains challenging and controversial. Currently most centers advocate open or endovascular intervention for patients with evidence of malperfusion, rupture or impending rupture, continued pain, or aneurysm formation. Regardless of the type of intervention, the incidence of complications or death remains high, even when undertaken in an elective setting. The standard endovascular treatment usually involves placement of a stent graft into the true lumen of the dissection in an effort to exclude the false lumen. This case report describes the placement of a branched stent graft into the false lumen of a patient with chronic type B dissection to encourage exclusion and thrombosis of the true lumen whilst maintaining flow to all visceral vessels.

Paraplegia prevention branches: a new adjunct for preventing or treating spinal cord injury after endovascular repair of thoracoabdominal aneurysms.

In this report, we describe a technique that could potentially be used for both prevention and treatment of spinal cord ischemia (SCI) in endovascular repair of thoracoabdominal aneurysms. This technique involves using a specially designed endograft with side branches (paraplegia prevention branches [PPBs]), which are left patent to perfuse the aneurysmal sac and any associated lumbar or intercostal arteries in the early postoperative period. The use of PPBs with this technique is feasible and allows for a temporary controlled endoleak that may be useful for preventing or reversing spinal cord injury. This technique may be considered as an adjunct to the more standard perioperative physiological manipulations such as permissive hypertension and spinal fluid drainage.

Early outcome following endovascular repair of pararenal aortic aneurysms: triple- versus double- or single-fenestrated stent-grafts.

PURPOSE: To review the early outcome following endovascular repair of pararenal aortic aneurysm using fenestrated stent-grafts and to determine if the number of fenestrations required is predicative of outcome. METHODS: A retrospective analysis was conducted of 20 consecutive patients (18 men; mean age of 75 ± 7 years) treated with stent-grafts containing either ≤ 2 fenestrations (n = 10, group 1) or 3 fenestrations (n = 10, group 2). Target vessels also included those accommodated by a scallop (renal artery or superior mesenteric artery in group 1 and the celiac artery in group 2). RESULTS: Comorbidities were similar in both groups. Aneurysm size [median 6.9 (IQR 6.7-8.3) versus 6.0 cm (IQR 5.8-6.6), p = 0.03], procedure time (mean 6.6 ± 2.1 versus 4.6 ± 1.7 hours, p = 0.04), and intensive care stay [median 4.5 (IQR 2-14) versus 2 (IQR 1-3) days, p = 0.07] were greater in group 2. There were 2 postoperative deaths, both in group 2. Morbidity was significant and similar in both groups (4 patients in group 1 and 3 patients in group 2), including 1 patient requiring long-term hemodialysis. Target vessel preservation was similar in both groups (96% overall). There were 2 type II endoleaks (one in each group) and no type I or III endoleak. CONCLUSION: Triple-fenestrated stent-grafts allow patients with extensive pararenal aneurysms and significant comorbidity to be treated by endovascular means. Although the number of patients treated was small, which limited the validity of the comparison, longer procedures and greater early morbidity and mortality were seen in the triple-fenestrated group. At present, the procedures are technically more demanding and associated with increased risk compared with double or single fenestrations, but the technology continues to evolve.

Temporary axillobifemoral bypass as an adjunct to endovascular aneurysm repair using fenestrated stent grafts.

Prolonged endovascular procedures requiring a large diameter sheath in each groin can be associated with significant intraoperative lower limb ischemia, particularly in those with pre-existing peripheral vascular disease. We report the case of a patient who suffered severe ischemia-reperfusion injury following endovascular repair of a pararenal aortic aneurysm using a fenestrated stent graft and describe the use of temporary axillobifemoral bypass in a patient with similar comorbidities undergoing the same procedure. We propose this adjunctive technique as a means of maintaining antegrade limb perfusion and avoiding the peripheral and central metabolic consequences of ischemia-reperfusion injury.

Preloaded fenestrated stent-grafts for the treatment of juxtarenal aortic aneurysms.

PURPOSE: To describe a novel technique for target vessel catheterization in patients with juxtarenal abdominal aortic aneurysms requiring treatment with fenestrated stent-grafts (FSG). METHODS: The standard FSG design was modified, substituting a thin-wall tube for the solid central obturator that serves as both an attachment point for the distal end of the graft as well as a top cap retriever. Through this tube, two 0.020-inch wires are run from the hub of the delivery system through the stent-graft, out through each fenestration, and up to the proximal edge of the graft, where they are attached by sutures. The sutures are connected to a trigger wire on the control hub. The preloaded wires facilitate passage of a sheath to the fenestration, providing stability while target vessel catheterization takes place and avoiding the use of a large sheath in the contralateral groin. A third wire attached to the inside of the top cap facilitates its safe retrieval via a 6-mm balloon. The preloaded FSG was used in 5 male patients (mean age 75.6 years) with either juxtarenal aneurysms (n = 2) or aneurysms previously treated with infrarenal stent-grafts that had developed type I endoleak (n = 3). In 3 cases, a double fenestrated stent-graft was required, and in 2 cases a triple fenestrated device was deployed, with scallops for the superior mesenteric or celiac arteries. RESULTS: Sixteen of 17 target vessels were preserved, and all aneurysms were successfully excluded with no endoleak at completion. In 2 patients, tortuosity encountered during device delivery caused twisting of the wires within the preloaded FSG, preventing successful advancement of a sheath over a preloaded wire. An approach from the contralateral groin was necessary to complete the procedure in 1 case, but the target vessel was lost in the other. CONCLUSION: The use of a preloaded FSG is feasible and facilitates the catheterization of fenestrations and of target arteries. This method has the potential to reduce procedure times and lower the risk of intraoperative lower limb ischemia.