Thoracoabdominal Aortic Aneurysm Repair Research Articles

Spinal cord injury after open and endovascular repair of descending thoracic aneurysm and thoracoabdominal aortic aneurysm: an updated systematic review and meta-analysis.

Spinal cord injury (SCI) is a rare but severe complication after open or endovascular repair of descending thoracic aneurysms (DTAs) or thoracoabdominal aortic aneurysms (TAAAs). This meta-analysis aims to provide a comprehensive assessment of SCI rates and factors associated with SCI. A systematic literature search was performed in September 2022 looking for studies on open and/or endovascular repair of DTA and/or TAAA published after 2018, to update the results of our previously published meta-analysis. The primary outcome was permanent SCI. Secondary outcomes were temporary SCI, 30-day and in-hospital mortality, follow-up mortality, postoperative stroke, and cerebrospinal fluid (CSF) drain-related complications. Data were pooled as proportions using inverse-variance weighting. A total of 239 studies (71 new studies and 168 from our previous meta-analysis) and 61,962 patients were included. The overall pooled rate of permanent SCI was 3.3% [95% confidence interval (CI), 2.9-3.8%]. Open repair was associated with a permanent SCI rate of 4.0% (95% CI, 3.3-4.8%), and endovascular repair was associated with a permanent SCI rate of 2.9% (95% CI, 2.4-3.5%). Permanent SCI was 2.0% (95% CI, 1.2-3.3%) after DTA repair, and 4.7% (95% CI, 3.9-5.6%) after TAAA repair; permanent SCI rate was 3.8% (95% CI, 2.9-5.0%) for Crawford extent I, 13.4% (95% CI, 9.0-19.5%) for extent II, 7.1% (95% CI, 5.7-8.9%) for extent III, 2.3% (95% CI, 1.6-3.5%) for extent IV, and 6.7% (95% CI, 1.7-23.1%) for extent V TAAA aneurysms. The pooled rate of CSF drain related complications was 1.9% (95% CI, 0.8-4.7%) for severe, 0.4% (95% CI, 0.0-4.0%) for moderate, and 1.8% (95% CI, 0.6-5.6%) for minor complications. Permanent SCI occurs after both endovascular and open DTA or TAAA repairs. Open repairs and TAAA repairs have higher risk of SCI compared with endovascular or DTA repairs. In particular, extent II aneurysms present the highest overall risk of SCI.

Safety of cerebrospinal fluid drainage in descending and thoracoabdominal aortic replacement surgery.

Spinal cord injury (SCI) remains a significant morbidity of surgical repair of descending thoracic aortic aneurysms (DTAA) and thoracoabdominal aortic aneurysms (TAAA). We present our 17-year experience with cerebrospinal fluid drainage (CSFD) as a protective strategy during open surgical repair of descending and thoracoabdominal aortic disease. We conducted a retrospective chart review of 132 patients who underwent open surgical repair of DTAA and TAAA and dissections with concurrent use of CSFD for spinal cord protection. Information regarding survival, postoperative course, and complications related to CSFD use were extracted from electronic health records (EHR) and analyzed. Mean patient age was 65.4±13.0 years, and 82 (62.1%) were male. A CSFD was successfully inserted in all patients. The mean hospital length of stay after surgery was 12.2±11.2 days, and in-hospital mortality was 7.6%. Postoperative transient paresis was observed in 5 patients (3.8%), and permanent paraplegia was seen in 4 (3.0%). CSFD related complications were reported in 25 patients (19%). Complications included persistent cerebrospinal fluid (CSF) leakage, blood-tinged CSF (with subdural hematoma reported in 3 patients) and spinal cutaneous fistula in 9 (7%), 14 (11%), and 1 (1%), respectively. Long term survival was 50.9% at 15 years. CSFD is associated with minor complications, without major sequalae. It is a safe practice and likely contributes innocuously to decreased SCI in patients undergoing open repair of DTAA and TAAA.

Single-Site Review of Spinal Cord Protection Protocols Including the Utilization of Spinal Drains versus Medical Management with Branched Endovascular Aortic Repair

Spinal cord ischemia (SCI) continues to be a devastating complication after repair of thoracoabdominal aortic aneurysms. The objective of this review is to present our single-center outcomes after the implementation of a standardized neuroprotective protocol following branched endovascular aortic repair. A standardized neuroprotective protocol including preoperative steroids, acetazolamide, intraoperative hemodynamic parameters, and postoperative treatment goals was initiated in November 2019. Physician-modified branched endovascular repairs were completed at a single center from 2012 to 2021 with outcomes reviewed both before (n=107) and after (n=67) the implementation of the neuroprotective protocol. The primary end point was the incidence of any SCI event at 30 days. Secondary end points included all-cause mortality, stroke, myocardial infarction, and renal failure at 30 days. Patients with Crawford extents I-III, renal failure, or necessitating emergent repair were deemed high risk for SCI events and underwent a subset analysis. Survivability after SCI was estimated using Kaplan-Meier tables. Of the 174 consecutive patients treated, the 67 patients treated following implementation of the neuroprotective protocol were more likely to have experienced a prior myocardial infarction (26.9% vs. 14%; P=0.0466) and have a history of chronic obstructive pulmonary disease (64.3% vs. 45.8%; P=0.02). This group was more likely to be treated for paravisceral aneurysms (53.7% vs. 24.3%; P=0.0002). Postprotocol implementation, spinal drain use was lower (6% vs. 38.3%; P = <0.0001) with 100% of these drains placed in urgent or unstaged thoracoabdominal aortic aneurysm repairs as a part of the protocol. Rates of any SCI event among all patients before and after implementation of the protocol were 9.3% (n=10 of 107) and 6% (n=4 of 67; P=0.57), respectively. In comparison, the protocol significantly reduced SCI rates to 0 (0% vs. 17.1%; P=0.0407) in high-risk patients. Frequency of renal failure was reduced (3% vs. 14%; P=0.018) after initiation of the protocol. Patients in the postprotocol group had significantly improved 1-year mortality rate (9% vs. 27.1%; P=0.0035) and renal failure rates (2% vs. 15%; P=0.018). Regression models indicated that patients in the postprotocol group had lower likelihood of mortality and renal failure than patients in preprotocol group (P<0.05) and that spinal drain reduced mortality (P<0.1). Implementation of a standardized neuroprotective protocol that focuses on medical management and fluid dynamics may significantly reduce risk of SCI after branched endovascular repairs, with the most significant improvement of SCI outcomes involving those at greatest risk for developing SCI. Also noteworthy, there was significant improvement to 1-year survivability after the implementation of this neuroprotective protocol.

Rationale of the PAPAartis trial.

Surgical and interventional repair of thoracoabdominal aortic aneurysms improve survival significantly compared to the natural history of the disease. However, both strategies are associated with a substantial risk of spinal cord ischemia, which has been reported to occur-even in contemporary series by expert centers-in up to 12% of patients, depending on the extent of the disease. Following improved neurological outcomes after staged approaches in extensive clinical and long-term large animal studies, and the description of the "collateral network", the concept of "Minimally Invasive Staged Segmental Artery Coil Embolization" (MIS2ACE) was introduced by Etz et al. This concept of priming the collateral network in order to improve spinal cord blood supply showed promising experimental and early clinical outcomes, and consequently led to the initiation of the randomized controlled multicenter PAPAartis trial (Paraplegia Prevention in Aortic Aneurysm Repair by Thoracoabdominal Staging). This Keynote Lecture describes the background and rationale for this trial and gives an update on the current status.

Open, closed or a bit of both: a systematic review and meta-analysis of staged thoraco-abdominal aortic aneurysm repair.

Staged procedures are one strategy found to be beneficial for medium- to high-risk Crawford extent I-III thoraco-abdominal aortic aneurysm (TAAA) repair patients and may be performed through a variety of techniques. This review sought to compare the primary outcomes of spinal cord ischemia (SCI) and long-term mortality between three cohorts grouped by approach: open, endovascular, and hybrid. In accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a total of 919 references were extracted from a search of three online databases (Embase, PubMed, Scopus). Following application of inclusion/exclusion criteria and data extraction, quantitative meta-analysis was undertaken utilizing a random effects model. Kaplan-Meier (KM) curves were digitized and aggregated to graph estimated survival. A total of 20 studies representing 924 patients were included. SCI was highest in the endovascular group, at 9.8% of weighted means, followed by hybrid, and open groups at 3.2% and 1.4%, respectively. However, 30-day mortality was highest in the open group at 6.0%, followed by the hybrid group at 3.8%, and endovascular at 3.6%. Aggregated long-term survival estimations are shown graphically, extending to 5 years for open and endovascular cohorts, and 3 years for the smaller hybrid cohort. While all cases incorporated spinal drainage, monitoring and staging for spinal protection, there is innate difference in approach when examining for cord ischemia. This systematic review and meta-analysis of staged TAAA repair describes the first comparison between cohorts of open and endovascular approach, revealing the increased risk of SCI and long-term mortality in endovascular repair.

Current approaches to spinal cord protection during open thoracoabdominal aortic aneurysm repair.

Spinal cord deficit (SCD) is a feared complication after thoracoabdominal aortic aneurysm repair. Vigilant management throughout the perioperative period is necessary to reduce the risk of SCD. Measures for preventing SCD during the intraoperative period include preoperative optimization and recognizing patients at a higher risk of SCD. In this manuscript, we discuss intraoperative adjuncts including utilization of cerebrospinal fluid drainage, left heart bypass, mild hypothermia, selective reimplantation of intercostal and lumbar arteries, and renal and visceral vessel perfusion. From the operative to the postoperative period, careful attention to avoiding hypotension and anemia is important. If SCD is recognized early, therapeutic intervention may be implemented to mitigate injury.

Impact of preoperative identification of the artery of Adamkiewicz on spinal cord injury after descending aortic and thoracoabdominal aortic repair.

Some recent reports have demonstrated that preoperative Adamkiewicz artery (AKA) identification and its targeted reconstruction has provided satisfactory outcomes with respect to spinal cord protection. This paper investigates the impact of preoperative identification of the AKA on reducing the incidence of spinal cord injury (SCI) in open repair (OR) and endovascular repair (EVR) of descending thoracic aortic (dTA) and thoracoabdominal aortic aneurysm (TAA) repair. The clinical data of patients with dTA and TAA treated between 2011 and 2022 were investigated. A total of 256 patients comprising of 201 males and 55 females, with a mean age of 72.1±10.0 years, were included. OR was used in 102 patients and EVR in 154 patients whose distal landing zone was below T8, all of which needed preoperative identification of the AKA. The AKA was identified in 207 (80.9%) patients, and was located in the level between T8 and T12 in 81.2%. In OR, the responsible arteries, including the identified AKA, were promptly reconstructed in 66 (64.7%) patients. In EVR, 65 (42.2%) patients had the AKA covered by an endovascular prosthesis. Deaths prior to 30 days occurred in seven (2.7%, four in OR and three in EVR) patients. In OR, SCI occurred in six (5.9%) patients including three (2.9%) with paraplegia and three (2.9%) with paraparesis, whereas in EVR ten (6.5%) patients had SCI, including two (1.3%) with paraplegia and eight (5.2%) with paraparesis. The incidence of SCI was significantly higher in patients with the AKA covered than those without it covered [13.8% (9 of 65) vs. 1.1% (1 of 89); P=0.002], whereas no significant differences were found between patients with or without the AKA reconstructed. Preoperative identification of the AKA was useful enough to determine treatment strategies with less likelihood of SCI in both OR and EVR for dTA and TAA pathologies.

Collateral network concept in 2023.

Extensive thoracoabdominal aortic aneurysm repair can cause spinal cord ischemia which significantly impacts survival and quality of life. Although this complication is uncommon, it is important to recognize the pathophysiology and preventative measures. In the 1990s, Dr. Griepp and colleagues proposed the existence of an extensive collateral network that supports spinal cord perfusion, "the collateral network concept". This includes an interconnecting complex of vessels in the intraspinal, paraspinous, and epidural spaces, and in the paravertebral muscles, involving the intercostal and lumbar segmental arteries as well as the subclavian and hypogastric (iliac) arteries. In this concept, as opposed to the one major segmental input model such as the Adamkiewicz artery, recognition of the importance of multiple inputs to the spinal circulation is paramount to maintaining the spinal blood flow and preventing spinal cord ischemia. In this article, we review the current evidence of the collateral concept and its application in aortic surgery.

Spinal cord protection for thoracoabdominal aortic aneurysm repair: from bench to bedside.

This keynote lecture and corresponding presentation discuss the anatomy and pathophysiology surrounding spinal cord injury in aortic surgery. This article will discuss risk factors and mechanisms for spinal cord injury, including loss of direct and collateral spinal cord perfusion and ischemia-reperfusion injury. This review will examine these elements in both the laboratory and clinical setting, in addition to other neuroprotective strategies applied in clinical practice. Addressing spinal cord injury requires an integrated and considerate approach to simultaneously optimize spinal cord blood flow, promote collateralization and improve ischemic tolerance. Given the catastrophic clinical consequences for both the patient and their caregivers, continuing to investigate and examine spinal cord injury is of the utmost importance.

Aortic hemodynamic and morphological analysis before and after repair of thoracoabdominal aortic aneurysm using a G-Branch endograft.

Background and objective: The G-Branch endograft is a novel multibranched "off-the-shelf" device used to repair thoracoabdominal aortic aneurysms (TAAAs). This report describes the hemodynamic and morphological performance of the G-Branch endograft in a human patient with TAAA. Materials and methods: We retrospectively reviewed the computed tomography angiography scans and clinical data of a woman in whom TAAA was treated using a G-Branch endograft. Patient-specific three-dimensional models were reconstructed, and computational fluid dynamics and morphological and hemodynamic indicators were analyzed before and after implantation of the device. Results: From a morphological perspective, there was an increase in cross-sectional area in the G-Branch endograft and all bridging stent grafts over time. Blood flow was redistributed among the renovisceral arteries, with a decrease in flow rate in the celiac artery and an increase in the left renal artery. Laminar blood flow was smoother and more rapid after implantation of the G-Branch device and remained stable during follow-up. In the bridging stent grafts, flow recirculation zones were found in the bridging zones of the celiac artery and superior mesenteric artery as well as the distal sealing zones of both renal arteries. Furthermore, higher time-averaged wall shear stress and a lower oscillatory index and relative resident time were found in the G-Branch endograft and bridging stent grafts. Quantitative analysis showed obvious reduction in the surface area ratio of the elevated time-averaged wall shear stress area and surface area ratio of the relative resident time after G-branch implantation. Conclusion: The revascularization of branch vessels occurred following G-branch implantation, with improvements arising not only from morphological changes but also from hemodynamic alterations. The long-term performance of the G-Branch endograft needs further investigation and clinical validation.

Discussion to: Risk profile and operative outcomes in patients with and without Marfan syndrome undergoing thoracoabdominal aortic aneurysm repair

Discussion to: Risk profile and operative outcomes in patients with and without Marfan syndrome undergoing thoracoabdominal aortic aneurysm repair

The result of prospective evaluation of 3-dimensional printing-aided extensive thoracoabdominal aorta repair.

Paraplegia is a distressing complication after open thoracoabdominal aortic aneurysm (TAAA) repair, and revascularization of T8-L2-level segmental arteries is considered pivotal to prevent paraplegia. We employed 3-dimensional (3D) printing to efficiently revascularize segmental/visceral arteries and prospectively evaluated its safety and efficacy. From January 1, 2020, to June 30, 2022, we prospectively enrolled patients of extent I, II, or III TAAA repair. Guidance models were 3D-printed based on preoperative computed tomography, and multibranched aortic grafts were manually constructed upon this model before surgery. The composite outcome of operative mortality, permanent stroke, and permanent spinal cord deficit (SCD) was compared with the historical control group (n=77, in 2015-2020), subjected to similar TAAA repair without 3D printing. A total of 38 patients (58.6± 13.2years) underwent open TAAA repair with the aid of 3D printing. Extent I, II, and III repairs were performed in 14 (36.8%), 17 (44.7%), and 7 (18.4%), respectively. Concomitant arch repair and bi-iliac reconstruction were performed in 7 (18.4%) and 6 patients (15.8%), respectively. Mean pump time was 107.7± 55.5minutes. Operative mortality, permanent stroke, and permanent SCD each occurred in 1 patient (2.6%), and the incidence of the composite outcome was 7.9% (3/38). In the control group, mean pump time was 166.0± 83.9minutes, significantly longer than the 3D-printing group (P<.001), and operative mortality, permanent stroke, permanent SCD, and the composite outcome occurred in 7 (9.1%), 9 (11.7%), 8 (10.4%), and 19 (24.7%), respectively. Open repairs of extensive TAAA with 3D printing showed favorable safety and efficacy, which need further validation by larger studies.

Neuromonitoring for descending thoracic and thoracoabdominal aortic aneurysm repair.

Neuromonitoring for descending thoracic and thoracoabdominal aortic aneurysm repair.

Dual-Lumen Stenting of Dissected Superior Mesenteric Artery During Fenestrated Branched Endovascular Repair of a Post-dissection Thoracoabdominal Aortic Aneurysm.

Long-segment aortic branch dissections have been considered a relative contraindication for fenestrated-branched endovascular aneurysm repair (FB-EVAR). This case report describes a technique of dual-lumen stenting of a fully-dissected superior mesenteric artery (SMA) to preserve patency of the true and false lumens during FB-EVAR. A 67-year-old man presented with a 6.0 cm extent III chronic post-dissection thoracoabdominal aortic aneurysm. The patient had highly-complex anatomy including dissection of the entire SMA. The true and false lumens of the dissected SMA were noted to be supplying different branches, requiring preservation of both lumens. The patient underwent a staged physician-modified FB-EVAR. A modified endograft containing 5 fenestrations and 1 branch cuff was introduced and the celiac, true-lumen SMA, and 3 renal arteries were sequentially catheterized using staggered deployment of the modified endograft. The false lumen SMA stent was catheterized via the branch cuff. Molded parallel grafting ("eye-of-the-tiger") technique was used to achieve double D configuration between the true and false lumens of the SMA. This case demonstrates feasibility of dual-lumen stenting to incorporate dissected target vessels during FB-EVAR while preserving flow to both the true and false lumens and the second-order branches they supply. We report a novel technique that allows incorporation of branch vessels affected by long segment dissection during fenestrated branched endovascular aortic repairs. This has potential advantage of preserving flow to all secondary branches of the dissected target vessels, while reducing the risk of type Ic endoleak.

The modified branch-first open repair of thoracoabdominal aortic aneurysms—video article

The modified branch-first open repair of thoracoabdominal aortic aneurysms—video article

Endovascular Repair of Thoracoabdominal Aortic Aneurysm: A Brief Review.

Thoracoabdominal aortic aneurysms (TAAAs) are complex and if untreated have high mortality and morbidity rates. Open surgical repair is the historical treatment approach; however, postoperative complications remain high with spinal cord ischemia notably one of the more serious and common complications. The avoidance of thoracotomy or laparotomy with the advent of endovascular aortic repair (EVAR) and thoracic endovascular aortic repair (TEVAR) have decreased the morbidity and mortality with TAAA repair, especially in patients with significant comorbidities such as a history of aortic surgery, underlying cardiac disease, and chronic obstructive pulmonary disease. Endovascular treatment options have grown to include fenestrated EVAR, multibranched EVAR, and physician-modified fenestration stent grafts. These techniques have achieved lower mortality rates than traditional open repair, but complications such as limb ischemia, spinal cord ischemia, and long-term durability must be considered. This review provides an overview of the most common endovascular techniques for TAAAs as well as short- and midterm outcomes.

Descending thoracic and thoracoabdominal aortic aneurysm repair using deep hypothermic circulatory arrest

Descending thoracic and thoracoabdominal aortic replacement is a complex and high-risk surgery. Deep hypothermic circulatory arrest (DHCA) is a surgical technique that is useful in large distal aortic arch aneurysms or chronic dissections that require fenestration where proximal cross clamping would be difficult. It can also be used as part of a multimodal strategy for end-organ protection. However, DHCA has potential adverse effects on the myocardial, cerebral, pulmonary, and coagulation systems. The use of DHCA is guided by the experience and preferences of the surgical team as well as the technical demands of the proposed surgery.

Outcomes of Elective and Non-elective Fenestrated-branched Endovascular Aortic Repair for Treatment of Thoracoabdominal Aortic Aneurysms.

To describe outcomes after elective and non-elective fenestrated-branched endovascular aortic repair (FB-EVAR) for thoracoabdominal aortic aneurysms (TAAAs). FB-EVAR has been increasingly utilized to treat TAAAs; however, outcomes after non-elective versus elective repair are not well described. Clinical data of consecutive patients undergoing FB-EVAR for TAAAs at 24 centers (2006-2021) were reviewed. Endpoints including early mortality and major adverse events (MAEs), all-cause mortality, and aortic-related mortality (ARM), were analyzed and compared in patients who had non-elective versus elective repair. A total of 2603 patients (69% males; mean age 72±10year old) underwent FB-EVAR for TAAAs. Elective repair was performed in 2187 patients (84%) and non-elective repair in 416 patients [16%; 268 (64%) symptomatic, 148 (36%) ruptured]. Non-elective FB-EVAR was associated with higher early mortality (17% vs 5%, P <0.001) and rates of MAEs (34% vs 20%, P <0.001). Median follow-up was 15 months (interquartile range, 7-37months). Survival and cumulative incidence of ARM at 3 years were both lower for non-elective versus elective patients (50±4% vs 70±1% and 21±3% vs 7±1%, P <0.001). On multivariable analysis, non-elective repair was associated with increased risk of all-cause mortality (hazard ratio, 1.92; 95% CI] 1.50-2.44; P <0.001) and ARM (hazard ratio, 2.43; 95% CI, 1.63-3.62; P <0.001). Non-elective FB-EVAR of symptomatic or ruptured TAAAs is feasible, but carries higher incidence of early MAEs and increased all-cause mortality and ARM than elective repair. Long-term follow-up is warranted to justify the treatment.

Open and endovascular repair of thoracoabdominal aortic aneurysm-a narrative review.

Thoracoabdominal aortic aneurysms (TAAAs) are associated with a high rate of morbidity and mortality when left untreated, yet their repair has been associated considerable risk as well. We aim to present a review of the epidemiology, risk factors, pathophysiology, natural history, management strategies, and current literature on open and endovascular repair of thoracoabdominal aortic aneurysms. A narrative review using current search of the most recent literature on this topic. Indication for surgical repair includes symptomatic aneurysms and those at a size or growth threshold. Open repair is the gold standard for surgical management of TAAA and remains so, however, endovascular repair has an increasingly broad applicability, and technology has correspondingly improved in the two decades since its introduction to clinical practice. Reported contemporary operative mortality has ranged from less than 5% to over 20%. The primary adverse complication of open and endovascular repair is ischemic injury, including renal injury, with reported incidence ranging from 2.8-12.5% in contemporary series, and spinal cord injury, with reported incidence ranging from 2.5% to 7.3% in contemporary series. Cerebrospinal fluid drainage has been shown to be the best-proven mechanism to date to prevent spinal cord injury in both open and endovascular repair. Endovascular repair is associated with a higher reintervention rate than open repair. Surgeon and center volume and expertise are related to clinical outcomes and should be taken into consideration when deciding on surgical repair.

The financial burden associated with endovascular repair of thoracoabdominal and pararenal aortic aneurysms using physician-modified fenestrated-branched endografts

Objective/BackgroundEndovascular thoracoabdominal and pararenal aortic aneurysm repair is more complex and requires more devices than infrarenal aneurysm repair. It is unclear if current reimbursement covers the cost of delivering this more advanced form of vascular care. The objective of this study was to evaluate the economics of fenestrated-branched (FB-EVAR) physician-modified endograft (PMEG) repairs. MethodsWe obtained technical and professional cost and revenue data for four consecutive fiscal years (July 1, 2017, to June 30, 2021) at our quaternary referral institution. Inclusion criteria were patients who underwent PMEG FB-EVAR in a uniform fashion by a single surgeon for thoracoabdominal/pararenal aortic aneurysms. Patients in industry-sponsored clinical trials or receiving Cook Zenith Fenestrated grafts were excluded. Financial data were analyzed for the index operation. Technical costs were divided into direct costs that included devices and billable supplies and indirect costs including overhead. Results62 patients (79% male, mean age: 74 years, 66% thoracoabdominal aneurysms) met inclusion criteria. The mean aneurysm size was 6.0 cm, the mean total operating time was 219 minutes, and the median hospital length of stay was 2 days. PMEGs were created with a mean number of 3.7 fenestrations, using a mean of 8.6 implantable devices per case. The average technical cost per case was $71,198, and the average technical reimbursement was $57,642, providing a net negative technical margin of $13,556 per case. Of this cohort, 31 patients (50%) were insured by Medicare remunerated under diagnosis-related group code 268/269. Their respective average technical reimbursement was $41,293, with a mean negative margin of $22,989 per case, with similar findings for professional costs. The primary driver of technical cost was implantable devices, accounting for 77% of total technical cost per case over the study period. The total operating margin, including technical and professional cost and revenue, for the cohort during the study period was negative $1,560,422. ConclusionsPMEG FB-EVAR for pararenal/thoracoabdominal aortic aneurysms produces a substantially negative operating margin for the index operation driven largely by device costs. Device cost alone already exceeds total technical revenue and presents an opportunity for cost reduction. In addition, increased reimbursement for FB-EVAR, especially among Medicare beneficiaries, will be important to facilitate patient access to such innovative technology.