Wolfgang Ritter

Postoperative Color Flow Duplex Scanning in Aortic Endografting

PURPOSE To report the feasibility and sensitivity of duplex sonography compared to computed tomography (CT) for aortic endograft follow-up surveillance. METHODS In a 26-month period, 113 aortic aneurysm patients received 79 tube and 34 bifurcated stent-grafts. Follow-up used contrast-enhanced CT scanning and duplex sonography with an intravenous ultrasound contrast agent (Levovist). RESULTS Eleven patients (9.7%) were converted to open repair; 1 died from hemorrhagic shock secondary to retroperitoneal hematoma. The mean follow-up time was 7.2 months (range 1 to 24), during which 5 patients died of unrelated causes. Sixteen primary (within 30 days) and 5 secondary endoleaks were detected by duplex after tube graft implantation. Among 5 endoleaks due to retrograde side-branch perfusion, 3 were detected only with contrast-enhanced duplex scanning. Iliac artery occlusion was also documented using duplex; however, 2 stent fractures could not be seen with ultrasound. Ten primary endoleaks were detected in bifurcated stent-graft patients. One endoleak originating from the distal iliac limb anchoring site was missed by duplex owing to bowel gas. Graft limb thrombosis was clearly identified by lack of a flow signal on duplex. CONCLUSIONS Duplex sonography could be a valuable, reliable, and economical surveillance tool for endovascular aortic reconstructions. The adjunctive use of an intravenous ultrasound contrast agent increased the sensitivity for detecting endoleak to a level comparable to contrast-enhanced CT scanning. However, stent fractures may not be seen on ultrasound, and bowel gas can interfere with obtaining an adequate image.

Aortic aneurysm size and graft behavior after endovascular stent-grafting: clinical experiences and observations over 3 years.

Purpose: To assess the long-term safety and efficacy of aortic endografts in terms of clinical outcome, continuing aneurysm exclusion, and changes of aneurysm size and graft configuration. Methods: Between August 1994 and July 1997, 190 patients (176 men; mean age 68.7 years, range 40–87) with aortic and aortoiliac aneurysms were treated with endovascular stent-grafts (Stentor, Vanguard, and EGS) in a tertiary care municipal hospital setting. Follow-up involved clinic visits every 3 to 6 months with contrast-enhanced computed tomography (CT), color duplex, and plain abdominal radiographs at regular intervals; angiography was used selectively. All data were collected prospectively and entered into a computerized database. Results: Implantation was possible in 188 (98.9%) patients. Early conversion to open surgical repair was required in 14 (7.4%) patients. Primary endoleaks were detected in 32 (16.8%) patients. Perioperative mortality was 0.53% (1/190). During follow-up, 17 (8.9%) additional patients were converted to open repair over a mean 20.9 months. Thirty-seven secondary procedures to treat endoleaks and pelvic outflow occlusions were performed in 30 (15.8%) patients. Changes in stent configuration suggestive of endograft disintegration were observed in 31 (29.8%) of 104 abdominal radiographs. Intraluminal layering of thrombus was seen on contrast-enhanced CT images in 20 patients. A significant trend (χ24 = 12.34, p < 0.025) toward aneurysm enlargement was seen in patients with persistent endoleaks at a mean 18-month follow-up. Conclusions: Although endoleaks after aortic stent-graft placement tend to cause ongoing aneurysm growth, we have also observed aneurysm shrinkage despite ongoing endoleak. The presence or absence of an endoleak in itself may be a poor predictor of successful stent-graft therapy. Lifelong surveillance is needed to assure successful aneurysm exclusion and stability or shrinkage of the aneurysm sac. Technical improvements in stent materials and design are necessary to guarantee long-term stability and safety of the device.

Fenestrated and Branched Stent-Grafts to Treat Post-Dissection Chronic Aortic Aneurysms After Initial Treatment in the Acute Setting

Purpose To present our initial experience treating post-dissection thoracoabdominal aneurysms with fenestrated and branched grafts. Methods Six patients (all men; mean age 62 years, range 44–71) with post-dissection thoracoabdominal aortic aneurysms were selected for treatment with fenestrated and branched grafts. All patients were initially treated with open surgery or endovascular treatment for their acute dissection. In total, 21 visceral arteries were targeted (3 celiac arteries, 6 superior mesenteric arteries, 12 renal arteries). Results Technical success was achieved in all cases, with no mortality or paraplegia. At completion angiography, all target vessels were patent, and no type I endoleak was seen. A type II endoleak was present in 4 patients, with the false lumen still partially perfused. During follow-up (mean 9 months, range 3–15), no patients died. One targeted renal artery occluded at 1 month. One type lb endoleak in a left renal artery was successfully treated with additional stenting. Five of the 6 patients had a 6-month follow-up. On abdominal ultrasound, 3 type II endoleaks were still seen. In 2 of these patients, the endoleak was resolved, the false lumen was completely thrombosed, and the maximum aortic diameter had regressed on the 1-year CTA. Conclusion Although longer follow-up results are needed, treatment with fenestrated and branched stent-grafts seems feasible and may be a promising option for the treatment of chronic post-dissection aortic aneurysms.

Spinal cord ischemia after endovascular repair of thoracoabdominal aortic aneurysms with fenestrated and branched stent grafts

OBJECTIVE The aim of this study was to report the incidence and associated risk factors of perioperative spinal cord ischemia (SCI) after endovascular repair of thoracoabdominal aortic aneurysms (TAAAs) with fenestrated and branched stent grafts. METHODS The study included consecutive patients with TAAA treated with fenestrated and branched stent grafts within the period January 2004 to December 2014. Suprarenal abdominal aortic aneurysms treated with fenestrated and branched grafts, even if including all four visceral vessels, were excluded. Patients who died within 30 days after the procedure were excluded from the analysis for SCI. All data were collected prospectively. RESULTS A total of 218 patients (167 men; mean age, 68.8 ± 7.5 years) were treated. Thirty-day mortality was 17 patients (7.8%). TAAA distribution among the 201 surviving patients was as follows: type I, n = 17 (8.5%); type II, n = 55 (27.4%); type III, n = 63 (31.3%); type IV, n = 54 (26.9%); and type V, n = 12 (5.9%). In the surviving patients, 21 (10.4%) developed perioperative SCI. At 30 days postoperatively, 13 (6.5%) of those patients had transient lower limb weakness, 5 patients (2.5%) had persistent lower limb weakness requiring assistance to stand or to walk, and 3 patients (1.5%) had persistent paraplegia. Five of the 21 patients awoke from anesthesia with a neurologic deficit. The remaining 16 patients had a later postoperative onset of SCI, with the majority of them (14 of 16) within 72 hours after the operation. Multivariate analysis using logistic regression identified operation time >300 minutes (odds ratio [OR], 7.4; 95% confidence interval [CI], 2.6-21.1; P < .001), peripheral arterial disease (OR, 6.6; 95% CI, 2-21.9; P = .002), and baseline renal insufficiency (glomerular filtration rate <30 mL/min; OR, 4.1; 95% CI, 1.1-16.1; P = .04) as independent risk factors for SCI. CONCLUSIONS In our experience, most SCI events after endovascular TAAA repair are transient, with persistent paraplegia being rare. Patients with prolonged procedure duration, peripheral arterial disease, and baseline renal insufficiency appear to be at higher risk for development of SCI after endovascular TAAA repair.

Preliminary embolization of the hypogastric artery to expand the applicability of endovascular aneurysm repair.

Purpose: To evaluate the efficacy and safety of preliminary hypogastric artery (HA) embolization prior to endovascular aneurysm repair (EVAR). Methods: A retrospective review was conducted of all 101 consecutive patients (91 men; mean age 73.4±8.7 years) who underwent preliminary embolization of 133 HAs ~4 to 6 weeks prior to EVAR from January 2005 to August 2009. Fourteen patients with 19 HAs were treated using coils, while 87 patients were treated with Amplatzer Vascular Plugs (AVP) in 114 HAs. All the patients were evaluated before discharge; at 1, 3, and 6 months; and annually thereafter to evaluate the clinical symptoms, potential endoleaks, and the aneurysm size. Results: In the coil group, complete occlusion was achieved in 16 (84.2%) of 19 procedures. There were no acute pelvic ischemic symptoms after HA embolization or EVAR. Five (35.7%) patients had buttock claudication and 2 (16.7%) of 12 men experienced new erectile dysfunction after embolization. At a mean 42.2-month follow-up (range 14–58), 3 (21.4%) patients had a type II leak via retrograde flow in the HA without aneurysm growth and were under observation. In the AVP group, all 114 HAs in 87 patients were successfully occluded; there was no device dislodgment or acute pelvic or limb ischemia observed. Buttock claudication and new sexual dysfunction developed in 12 (13.8%) patients and 4 (5.1%) of 79 men after the procedure, respectively. During a mean 26.4-month follow-up (range 4–54), 2 (2.3%) patients developed distal type I endoleaks after EVAR, but angiography confirmed that neither of the endoleaks was related to the vessel embolized with the AVP. Comparing the outcomes of the treatment groups, the AVP was placed with fewer intraoperative complications (p = 0.013) and more complete occlusion (p=0.01) than coil embolization. The rate of buttock claudication was lower in the AVP group (p=0.042). Conclusion: Hypogastric artery embolization prior to EVAR is safe and effective. In our experience, the AVP affords easier and more precise placement and provides more

Early follow-up after endovascular aneurysm repair: is the first postoperative computed tomographic angiography scan necessary?

Purpose To examine whether initial postoperative computed tomographic angiography (CTA) is needed in all patients undergoing endovascular aneurysm repair (EVAR). Methods A total of 105 consecutive patients underwent EVAR with standard infrarenal devices in our department between November 2009 and May 2011. Five patients were excluded due to severe renal insufficiency, leaving 100 (85 men; median age 73 years, range 46–91) eligible for prospective enrollment in a triple-modality early postoperative follow-up protocol [intraoperative completion angiography, postoperative duplex ultrasonography (DUS), and plain abdominal radiography). Findings were compared for sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) against the first postoperative CTA results for the detection of endoleaks or other signs of EVAR failure. Results There were 10 inconclusive DUS examinations. In the remaining 90 patients, DUS had 75.0% sensitivity, 95.4% specificity, 85.7% PPV, and 91.5% NPV for the detection of endoleaks. The intraoperative angiogram, DUS, and abdominal radiograph combined resulted in 87.5% sensitivity and 95.4% specificity, with a 65.6% PPV and 94.8% NPV for the detection of endoleaks. In 2 patients who required a reintervention for endoleak in the early postoperative period, both endoleaks were correctly detected by the triple-modality early postoperative follow-up protocol. Conclusion An early follow-up protocol consisting of an intraoperative completion angiogram, DUS, and abdominal radiograph shows a high sensitivity and NPV for the detection of endoleaks and should detect early migration or kinking of the stent-graft. An initial postoperative CTA is not necessary for most patients undergoing EVAR and should be reserved for those individuals in whom the aforementioned modalities are inconclusive or show signs of endoleak or other EVAR failure.

Aortocaval fistula after stent-graft repair

Purpose: To report an aortocaval fistula after stent-graft repair and the feasibility of interventional treatment. Case Report: A 78-year-old man with a 61-mm infrarenal aortic aneurysm (AA) was treated successfully with a Zenith bifurcated stent-graft. Three years later, the patient presented with deteriorating renal function and acute bronchial obstruction. Computed tomography showed an aortic diameter increased to 90 mm, dilatation of the inferior vena cava, and a distal type I endoleak. The patients condition quickly deteriorated, and emergent imaging found a fistula with brisk flow between the aneurysm sac and the left iliac vein within a distal type I endoleak. During emergency endovascular repair, iliac extensions were implanted in the right common iliac artery and left external iliac artery. The left hypogastric artery was coil embolized to exclude flow into the aneurysm sac. After positioning the extensions, cardiac function improved, and the fistula was no longer palpable. The cardiac indices and renal function normalized, and he was discharged 20 days after admission. Conclusion: Aortocaval fistulas are a rare complication of AA stent-graft repair and may be successfully treated by interventional means.

Endovascular management of chronic post-dissection aneurysms

Open repair is still the gold standard in acute type A dissection. Endovascular repair is advocated for complicated acute type B dissections. Recent evidence also supports the role of endovascular repair in a larger proportion of uncomplicated acute type B dissections. The role of endovascular repair in chronic post-dissection aneurysms, however, is still unclear. Most commonly, post-dissection aneurysms involve the thoracoabdominal aorta, making the use of fenestrated/branched stent-grafts to achieve complete aneurysm exclusion mandatory. These fenestrated/branched stent-grafts have been used with success in atherosclerotic thoracoabdominal aortic aneurysms (TAAAs). In chronic post-dissection aneurysms, however, additional technical challenges arise. The usually narrow true lumen makes the use of branches more tedious and overall planning difficult. A second technical challenge relates to the fact that visceral branches can also originate from the false lumen. In such cases, perforation of the stiff chronic dissection flap is required to obtain access to the vessel. During the period January 2010 to November 2013, 17 patients (13 males, mean age 65±7.8 years) with chronic thoracoabdominal aneurismal degeneration following acute dissection were treated in our department with the use of fenestrated/branched stent-grafts. Technical success was achieved in all cases (100%). Perioperative mortality was two (11.8%) patients. One patient died due to multiple organ failure and one due to cardiac failure. No case of paraplegia was observed. During a 12-month median follow-up (range, 4-28 months) no aneurysm-related deaths were observed. Reintervention was required in three cases to repair a type Ib endoleak from a side branch. Endovascular treatment with fenestrated/branched stent-grafts is feasible for chronic post-dissection aneurysms. Standard thoracic stent-grafting is an option in a minority of patients, when the aneurysm is limited to the thoracic segment. Fenestrated and branched devices can successfully be used for aneurysms extending to the thoracoabdominal aorta.

Retrograde Target Vessel Catheterization as a Salvage Procedure in Fenestrated/Branched Endografting.

Purpose: To present retrograde target vessel catheterization as a bailout technique in fenestrated and branched endografting (F/B-EVAR). Methods: Between November 2003 and November 2014, 11 (1.6%) of 671 consecutive patients with juxtarenal, suprarenal, and thoracoabdominal aortic aneurysms required retrograde target vessel access as a bailout measure during F/B-EVAR due to failure of an antegrade approach. The target vessels involved the left renal artery (LRA) in 6 patients, the celiac artery (CA) in 3 patients, the right renal artery (RRA) in 1 patient, and both renal arteries in 1 patient. Results: The target vessels were successfully catheterized and secured with stent-grafts in 10 patients; a single case was unsuccessful because the fenestration was in the wrong position and blocked against the arterial wall. One (9.1%) patient died within 30 days. Major perioperative complications occurred in 6 patients, including 3 with renal function deterioration, 2 with access-site wound dehiscence, and a case of pneumonia. Median hospital stay was 20 days (range 7–60) and median intensive care unit stay was 2.5 days (range 0–9). Over a mean 26-month follow-up (range 1–60), one unrelated death occurred. Reintervention was required in 1 patient due to progression of an aneurysm of the right iliac artery. Conclusion: Retrograde target vessel access in F/B-EVAR is a feasible bailout procedure when antegrade cannulation fails. Secondary technical success is high, but the procedure is associated with higher perioperative morbidity and longer hospital stay.

Comparison of outcomes for double fenestrated endovascular aneurysm repair versus triple or quadruple fenestrated endovascular aneurysm repair in the treatment of complex abdominal aortic aneurysms

Objective: This study compared outcomes of standard fenestrated endovascular aneurysm repair (St‐FEVAR) with renal artery fenestrations only with more complex FEVAR (Co‐FEVAR) with additional fenestrations for the superior mesenteric artery or the celiac trunk, or both. Methods: All consecutive patients treated with FEVAR for short‐necked, juxtarenal, or suprarenal aortic aneurysms between January 2010 and July 2016 were included. Patients with stent grafts with a combination of fenestrations and branches were excluded. Data were collected prospectively. All stent grafts used were customized based on the Zenith system (William A. Cook Australia, Ltd, Brisbane, Queensland, Australia). Results: A total of 384 patients (345 men; mean age, 72.7 ± 7.8 years) were treated. St‐FEVAR was used in 199 patients (51.8%) and Co‐FEVAR in 185 (48.2%), including 30 patients with a quadruple FEVAR. Overall technical success was 373 of 384 (97.1%), and the difference between the St‐FEVAR group (195 of 199 [98%]) and the Co‐FEVAR group (178 of 185 [96.2%]) was not statistically significant (P = .37). Mean operative time was 135 ± 46 minutes for St‐FEVAR and 176 ± 53 minutes for Co‐FEVAR (P < .001). Mean fluoroscopy time was 45 ± 17 minutes for St‐FEVAR and 57 ± 21 minutes for Co‐FEVAR (P < .001). Overall 30‐day mortality was two of 384 (0.5%), and the difference between the two groups was not statistically significant (St‐FEVAR: 1 of 199 [0.5%] vs Co‐FEVAR: 1 of 185 [0.5%]; P = 1.0). Major perioperative complications between St‐FEVAR group (22 of 199 [11.1%]) and Co‐FEVAR group (24 of 185 [13%]) were similar (P = .64). Mean follow‐up was 20 ± 17.1 months. Estimated survival at 1 and 3 years was 95% ± 1.7% and 83.4% ± 3.6% for St‐FEVAR vs 94% ± 2.4% and 89.4% ± 3.5%, respectively, for Co‐FEVAR (P = .96). Estimated freedom from reintervention at 1 and 3 years was 97.9% ± 1.2% and 90.5% ± 3.1% for St‐FEVAR vs 95.4% ± 2.0% and 89.1% ± 4.2%, respectively, for Co‐FEVAR (P = .5). Estimated target vessel patency at 1 and 3 years was 99.2% ± 0.4% and 98.6.0% ± 0.6% for St‐FEVAR vs 98.6% ± 0.6% and 97.9% ± 0.9%, respectively, for Co‐FEVAR (P = .48). Conclusions: Co‐FEVAR is not associated with an increase in perioperative mortality and morbidity compared with St‐FEVAR. Co‐FEVAR requires longer procedure and fluoroscopy duration, but technical success rates are as high as in St‐FEVAR. A liberal use of Co‐FEVAR is therefore justified whenever a longer and higher proximal sealing zone is needed.