Endovascular Repair Procedures Research Articles

FRI0463 Outcomes of Vascular Interventions in Takayasu's Arteritis; A Retrospective Cohort Study

BackgroundTakayasu's arteritis (TAK) is a large-vessel vasculitis of unknown etiology affecting primarily the aorta and its branches. Despite treatment with immunosuppressive agents patients with TAK often develop arterial damage requiring...

Cerebrovascular complications and utilization of endovascular techniques following transsphenoidal resection of pituitary adenomas: a study of the Nationwide Inpatient Sample 2001–2010

Cerebrovascular complications following transsphenoidal resection of pituitary tumors are rare and often evaluated and treated with endovascular techniques. We determined the utilization rate and outcomes of endovascular procedures in transsphenoidal pituitary resection patients using an administrative database. Using the Nationwide Inpatient Sample 2001-2010, patients receiving transsphenoidal resection of benign pituitary tumors were identified. The rate of cerebrovascular complications and utilization of endovascular repair procedures and cerebral angiography were compared between high (≥ 75 procedures/year) and low volume (<75 procedures/year) centers. Chi squared tests were used to compare categorical variables. 70,878 were patients included in this study. ICH/SAH occurred in 0.9 % of patients (652/70,878) and stroke occurred in 0.5 % of patients (327/70,878). Patients treated at high volume centers had significantly lower rates of stroke (0.5 % vs. 1.0 %, P = 0.04), and ICH/SAH (0.5 vs. 1.0 %, P = 0.05) when compared to patients treated at low-volume centers. Overall, 531 patients (0.7 %) received post-operative angiography and 83 patients (0.1 %) received endovascular repair procedures. High volume center patients underwent angiography in 0.4 % of cases compared to 0.9 % for low volume center patients (P = 0.02). There was no significant difference in endovascular repair procedure rates at high and low volume centers (0.1 vs. 0.2 %, P = 0.37). Cerebrovascular surgical complications requiring cerebral angiography and endovascular repair are rare among transsphenoidal pituitary resection patients. These occur with higher frequency at low volume centers and are associated with high mortality rates.

The benefits of treating abdominal aortic aneurysms with minimally invasive endovascular repair

Open repair, endovascular repair (EVAR) and optimal medical therapy each have a role to play in the management of abdominal aortic aneurysms (AAAs); however, the latter has proven to be ineffective in preventing the expansion and rupture of AAAs. The benefits of EVAR over open repair of AAAs have been repeatedly demonstrated in the shortto medium-term and, as a result, EVAR is the treatment of choice in most vascular centers. In 2006, the number of EVAR procedures performed in the USA exceeded that of open repair and this paradigm shift toward EVAR continues. However, despite global dissemination of endovascular technology, unproven benefits continue to cause controversy, such as long-term durability, surveillance, emergency repair, the use of endografts outside of the instructions for use (IFU), costs, patient age and screening. These unresolved issues will strongly influence technical developments and future configuration of vascular services.

Late conversion of endovascular to open repair of abdominal aortic aneurysms

Failure of endovascular repair (EVAR) of an abdominal aortic aneurysm can result in significant risk of morbidity and mortality. We review our experience with late conversions to open repair. We conducted a retrospective database review to identify all EVAR procedures performed between 1997 and 2010 and the number converted to open repair at our university-affiliated medical centre. Late conversion was defined as those occurring at least 30 days after initial EVAR. In all, 892 EVARs took place during the study period. Six patients (0.7%) required late conversion to open repair. Their mean age was 71 (range 58-83) years, and half were women. Half of the initial EVARs were for ruptured aneurysms. The median time to conversion was 15.6 (range 1.7-61.3) months. Indications for secondary conversion (50% urgent, 50% elective) included persistent type I endoleak (n = 3), combined type II and III endoleak (n = 1), graft thrombosis (n = 1) and aneurysm rupture (n = 1). Supraceliac clamping was required in most patients (67%), and the mean transfusion requirement was 2.6 units. Total endograft explantation occurred in 2 patients (33%), whereas partial or total endograft preservation occurred in 4 (67%). Median length of stay in hospital after conversion was 7 (range 6-73) days. There were no instances of early or in-hospital mortality following conversion. Our EVAR experience includes a low rate of late conversion to open repair, with most conversions being a result of persistent aneurysm perfusion. Although technically challenging, late conversion can be safe. Our experience supports ongoing surveillance after EVAR.

Arch and visceral/renal debranching combined with endovascular repair for thoracic and thoracoabdominal aortic aneurysms

We report a single-center experience using the hybrid procedure, consisting of open debranching, followed by endovascular aortic repair, for treatment of arch/proximal descending thoracic/thoracoabdominal aortic aneurysms (TAAA). From 2005 to 2010, 51 patients (33 men; mean age, 70 years) underwent a hybrid procedure for arch/proximal descending thoracic/TAAA. The 30-day and in-hospital morbidity and mortality rates, and late endoleak, graft patency, and survival were analyzed. Graft patency was assessed by computed tomography, angiography, or duplex ultrasound imaging. Hybrid procedures were used to treat 27 thoracic (16 arch, 11 proximal descending thoracic) and 24 TAAA (Crawford/Safi types I to III: 3; type IV: 12; type V: 9). The hybrid procedure involved debranching 47 arch vessels or 77 visceral/renal vessels using bypass grafts, followed by endovascular repair. Seventy-five percent of debranching and endovascular repair procedures were staged, with an average interval of 28 days. Major 30-day and in-hospital complications occurred in 39% of patients and included bypass graft occlusion in four, endoleak reintervention in two, and paraplegia in one. Mortality was 3.9%. During a mean follow-up of 13 months, three additional type II endoleaks required intervention, and one bypass graft occluded. No aneurysm rupture occurred during follow-up. Primary bypass graft patency was 95.3%. Actuarial survival was 86% at 1 year and 67% at 3 years. The hybrid procedure is associated with acceptable rates of mortality and paraplegia when used for treatment of arch/proximal descending thoracic/TAAA. These results support this procedure as a reasonable approach to a difficult surgical problem; however, longer follow-up is required to appraise its ultimate clinical utility.

The Hybrid Procedure: Arch and Visceral/Renal Debranching Combined with Endovascular Repair for Thoracic/Thoracoabdominal Aortic Aneurysms

Objective: To report a single-center experience using a hybrid procedure (open debranching, followed by endovascular aortic repair) for treatment of thoracic/thoracoabdominal aortic aneurysms. Methods: From 2005-2010, 48 patients (31 men; mean age, 71) underwent a hybrid procedure for thoracic/thoracoabdominal aortic aneurysms. Thirty-day, in-hospital morbidity, and mortality; and late endoleak, graft patency, and survival were analyzed. Graft patency was assessed by CT, angiography, or duplex ultrasound. Results: Hybrid procedures were used to treat 24 thoracic (11 arch, 13 descending), 19 thoracoabdominal (Crawford type I-III: 3, type IV: 7, type V: 9), and 5 para-anastomotic aortic aneurysms. The hybrid procedure involved debranching arch vessels (47) or visceral/renal vessels (73) using bypass grafts, followed by endovascular repair. Eighty percent of debranching and endovascular repair procedures were staged, with an average interval of 25 days. Major 30-day and in-hospital complications occurred in 38% of patients, and included bypass graft occlusion (4), endoleak reintervention (2), and paraplegia (1). Thirty-day and in-hospital mortality was 4.2%, secondary to bowel ischemia in one patient and aneurysm rupture in the other. During a mean follow-up of 13 months, three type II endoleaks required four interventions. Seven patients died: one of sepsis, one of respiratory failure, and five of unknown cause. There were no documented aneurysm-related deaths or new graft or limb occlusions. Primary bypass graft patency was 96%. Actuarial survival was 85% at 1 year and 67% at 3 years. Conclusions: The hybrid procedure for the treatment of thoracic/thoracoabdominal aortic aneurysms is a competitive alternative to traditional open repair and endovascular repair with branched stent grafts. The results validate this approach for the short-term to midterm; however, longer follow-up is required to appraise its durability.

Invited commentary

Invited commentary

Initial results of wireless pressure sensing for endovascular aneurysm repair: The APEX Trial—Acute Pressure Measurement to Confirm Aneurysm Sac EXclusion

Complete exclusion and depressurization of the aneurysm sac is the prime goal of endovascular repair (EVAR) of abdominal aortic aneurysms. Thus, any EVAR that results in a type I or III endoleak has been classified as a technical failure. The current method to detect endoleaks uses intraoperative aortography. However, aortography is limited by its subjective nature, inability to quantify the significance of the endoleak, and artifacts such as bowel gas that may mimic an endoleak. In addition, repetitive contrast injection may impair renal function. To increase the efficacy and safety of intraoperative endoleak detection, a wireless pressure-monitoring system has been developed and tested in the clinical setting. The APEX trial (Acute Pressure Measurement to Confirm Aneurysm Sac EXclusion) is a prospective, multicenter/international trial sponsored by CardioMEMS to evaluate the safety and efficacy of the EndoSure wireless pressure sensor for EVAR. The 30 x 5 x 1.5-mm sensor contains no battery and is powered externally with radiofrequency energy. The sensors are extremely stable, operate over the full physiologic range of pressures, and have a resolution of 1 mm Hg. A total of 90 patients were enrolled at 12 sites, 76 of whom were eligible for analysis. The sensor was implanted via the contralateral femoral artery at the time of EVAR. The sac pulse pressure was measured with both an angiographic catheter and the sensor after deployment of the main endograft but before the deployment of the contralateral limb (type I endoleak equivalent). Sac pressure was again measured with the sensor after deployment of the contralateral limb and completion of the EVAR. Data were collected in a prospective manner. In all of the eligible patients (n = 76), the initial sensor pressure measurement agreed closely with the angiographic catheter pressure measurement of the type I endoleak equivalent. At the completion of the procedure, there was agreement between the sensor measurement and angiography regarding the presence or absence of a type I or III endoleak in 92.1% (n = 70) of the measurements. Overall, the sensitivity was 0.94 and the specificity was 0.80 for detecting type I or III endoleaks. Final pulse pressures decreased significantly compared with baseline measurements. Implantation of the wireless pressure sensor is safe, and remote aneurysm sac pressure sensing is feasible. It was a valuable guide in evaluating the completeness of the EVAR procedure. Long-term study will be needed to prove its efficacy for postoperative surveillance.

A single-center experience in open and endovascular treatment of hemodynamically unstable and stable patients with ruptured abdominal aortic aneurysms

To retrospectively compare a single center's immediate and mid-term outcomes of ruptured abdominal aortic aneurysm open and endovascular repair (EVAR) for two patient groups-hemodynamically stable and unstable patients-in the same time period. Patients presenting at our center with confirmed rupture of an abdominal aortic aneurysm between December 1999 and April 2006 were considered according to an intention-to-treat model with EVAR. Patients with symptomatic or acute (but not ruptured) AAAs were not included in this study. Thirty-three patients underwent EVAR, and 91 underwent open repair. Seventy-two patients (EVAR, 45%; open, 63%) were classified as hemodynamically unstable at arrival, and 52 were classified as stable (EVAR, 55%; open, 37%). Ninety-seven percent of EVAR procedures commenced under local anesthesia, and 100% of open repairs occurred with general anesthesia. Overall successful graft deployment, 30-day mortality, overall reintervention rate, and complications were the study primary end points. Overall successful graft deployment for EVAR was 91%; for open repair, it was 96%. Overall 30-day mortality for EVAR was 30% (unstable, 53%; stable, 11%), and the rate was 46% for open repair (unstable, 61%; stable, 21%). The EVAR postoperative reintervention rate (within 30 days) was 15% (unstable, 20%; stable, 11%), and for open repair it was 10% (unstable, 9%; stable, 15%). We recorded a 27% severe complication rate for EVAR patients (unstable, 40%; stable, 17%), and for patients treated with open repair, it was 33% (unstable, 35%; stable, 29%). Our overall EVAR eligibility rate was 52%, and our overall EVAR treatment rate was 27%. Our study's overall results for EVAR remain encouraging when compared with those of conventional repair, but large randomized trials are required to confirm the efficacy of the procedure.

Conversion to Open Repair After Endografting for Abdominal Aortic Aneurysm: Causes, Incidence and Results

ObjectiveTo evaluate frequency, causes and results of conversion to Open repair (OR) after endovascular repair (EVAR) in a single centre during an 8-year period. DesignSix hundred and forty-nine consecutive patients undergoing EVAR were followed up prospectively for endograft-related complications. OutcomesEarly conversion was any OR during or within 30 days from the primary EVAR. Late conversion was any OR with removal of the endograft after 30 days since a completed EVAR procedure. ResultsMedian patient follow-up was 38 months (1–93 months). Conversion to OR was performed in 38 patients; nine early and 29 late. Most (7/9) early conversions were due to extensive vessel calcification. Peri-operative mortality was 22% (2/9). Late conversions occurred at a median of 33 months after primary EVAR: 29 were elective and 4 urgent. During the same interval, 79 secondary endovascular interventions were performed, 7 of which failed. The risk of conversion to OR was 9% at 6 years. At multivariate logistic regression analysis, no single factor (short, large or angulated neck, suprarenal fixation, large pre-operative diameter, iliac aneurysms, ASA score risk) was associated with the risk of late failure requiring conversion to OR. ConclusionThe risk of death after early conversion should be recognized, to avoid forcing morphological indications for primary EVAR. Occurrence of late conversion after EVAR is not negligible, affecting almost 1 out of 10 patients after 6 years. In the presence of an expanding aneurysm after EVAR, especially after a failed secondary endovascular correction, an aggressive attitude in fit patients allows outcomes at similar to those of primary OR.

Open Versus Endovascular Repair of Abdominal Aortic Aneurysms: What Does Each Really Cost?

Endovascular repair (EVAR) of abdominal aortic aneurysm (AAA) has emerged as an alternative to open repair (OR). The aim of this study was to compare the clinical outcomes and specific costs of these procedures since commercialization.A retrospective analysis of 119 consecutive infrarenal AAA repaired via an EVAR or an OR between July 2000 and September 2001 was performed. Patient charts were reviewed. Diagnostic-related group (DRG) classification and payer mix were identified. The hospital cost accounting system was accessed to obtain actual variable direct cost (AVDC) for the two groups. Percentages of the mean AVDC for the two groups were compared in the following cost categories: graft, operating room, radiology procedures and supplies, pharmacy, respiratory therapy, clinical laboratories, surgical floor, and monitored unit. Hospital profit margins were determined. Fifty-five patients underwent EVAR and 64 patients underwent OR. Mean aneurysm size was 5.5A cm (EVAR) and 6.1A cm (OR). Mean intensive care unit (ICU) stay was 0.09 days for EVAR vs. 3.5 days for OR ( p < 0.05). Mean length of stay (LOS) was 1.96 days for EVAR vs. 7.3 days for OR ( p < 0.05). Reimbursement was based on DRG 110, 47.3% in the EVAR and 79.7% in the OR group ( p < 0.05), and DRG 111, 50.9% in the EVAR group and 12.5% in the OR group ( p < 0.05). The payer mix showed no significant differences between the two groups. Mean AVDC for EVAR was 1.74 times that of OR. Significant differences in the distribution of costs were found in the following: graft costs (58% vs. 6.3%, p < 0.05), radiology procedures and supplies (3.9% vs. 0.1%, p < 0.05), pharmacy (1.9% vs. 10.5%, p < 0.05), and monitored unit (7.3% vs. 24.65%, p < 0.05) comparing EVAR vs. OR, respectively. Median cost of an endovascular graft was 22.4 times that of the standard graft for OR. Average hospital profit margins for an EVAR case was 49.5% vs. 88.6% for OR. Despite significant differences in monitored unit utilization, pharmacy services, and respiratory therapy services by the OR group, the cost of EVAR is appreciably more expensive. Furthermore, increased DRG reimbursement, and decreased ICU use and LOS do not compensate for the cost of EVAR. The main cost of EVAR is the cost of the graft itself. Hospital profit margins are acceptable with both the EVAR and OR procedures at this time; however, with proposed reductions in reimbursement, the ability to cover the cost of this new technology may be threatened.

Stents for the Treatment of Aortic Aneurysms

The endovascular treatment of abdominal aortic aneurysms has generated a great deal of interest since the early 1990s, and many different devices are currently available. The procedure of endovascular repair has been evaluated in many institutions and the different devices are compared. The first results were encouraging, but complications like endoleak, dislocation or thrombosis of the graft occurred. By the available devices the stent application is only promising, if the known exclusion criteria are strictly respected. Therefore a careful preinterventional assessment of the patient by different imaging modalities is necessary. As the available results up to now are preliminary and the durability of the devices has to be controlled, multicenter studies are required to improve the devices and observe their long-term success in the exclusion of abdominal aortic aneurysms.