Aneurysm pulsatility after endovascular exclusion--an experimental study using human aortic aneurysms

Endotension Following Endovascular Aneurysm Repair: Retrospective Review of Treatment and Clinical Outcome

Purpose

: Endotension is a rare late complication characterized by an increase in sac size without any type of endoleak following endovascular aortic aneurysm repair (EVAR). Due to its rarity, few studies have demonstrated the mechanism behind and the management of endotension. In this study, we aimed to better understand the treatment and the long-term outcome of endotension in a single-center cohort.

Materials and Methods

: This study was designed for a retrospective review of the patients diagnosed with endotension between January 2006 and December 2017. The study patients were categorized into two groups (primary versus secondary) based on the presence of any type of endoleak before the diagnosis of endotension. We collected data related to endotension treatment, intraoperative findings, and long-term outcomes.

Results

: In a cohort of 15 patients diagnosed with endotension following EVAR, eight were classified into the primary endotension (PE) group without prior endoleak, and seven exhibited secondary endotension (SE). Among the eight PE patients, endovascular intervention for a preemptive purpose was conducted in six patients; however, three (50%) showed continuous sac expansion and finally received open conversion. Overall, eight patients (five in PE and three in SE) underwent open conversion, and one (12.5%) presented with an undetected endoleak during the operative findings. Postoperative morbidity was observed in three patients with no operative mortality.

Conclusion

: Endotension can be managed initially through simple observation for changes on serial images, along with preemptive endovascular intervention. However, surgical intervention should be considered for patients with specific indications including continuous aneurysm sac enlargement, presence of symptoms, suspicions of migration of stent-graft with endoleak, and infection.

Single centre experience with Excluder® stent graft; 17-year outcome

BACKGROUND

Endovascular abdominal aortic aneurysm repair (EVAR) has become a mainstay of abdominal aorta aneurysm treatment. Long term follow-up on specific stent grafts is needed.

PATIENTS AND METHODS

This study included 123 patients (104 men; mean age 73.0 years, range 51-89) with abdominal aorta aneurysm, treated with Excluder^® stent graft between October 2002 and June 2008. Periprocedural and follow-up data were retrieved by reviewing the records of our institution, while time and cause of death were retrieved from the National Institute of Public Health. If an abdominal aortic aneurysm rupture was listed as the cause of death, records were retrieved from the institution that issued the death certificate. Our primary goal was to assess the primary technical success rate, type 1 and type 2 endoleak, reintervention free survival, 30-day mortality, the overall survival and aneurysm rupture-free survival.

RESULTS

The median follow-up was 9.7 years (interquartile range, 4.6-13.8). The primary technical success was 98.4% and the 30-day mortality accounted for 0.8%. Secondary procedures were performed in 29 (23.6%) patients during the follow-up period. The one-, five-, ten-, fifteen- and seventeen-year overall survival accounted for 94.3%, 74.0%, 47.2%, 35.8% and 35.8%, while the aneurysm-related survival was 98.4%, 96.3%, 92.6%, 92.6%, 92.6%. In seven (5.7%) patients, abdominal aortic rupture was found as the primary cause of death during follow-up.

CONCLUSIONS

Our data showed that EVAR with Excluder^® stent graft offers good long-term results. More than 75% of patients can be treated completely percutaneously. Late ruptures do occur in the first ten years, raising awareness about regular medical controls.

Surgical Findings and Outcomes of Endotension following Endovascular Aneurysm Repair

BACKGROUND

Endotension is one of the detrimental complications after endovascular aneurysm repair (EVAR) and surgical management has been considered as standard of care. However, there is a paucity of data regarding the findings and outcomes of such surgical intervention. The aim of this study was to investigate intraoperative findings and outcomes of surgical treatment for endotension after EVAR.

METHODS

Between January 2005 and October 2018, of the 708 patients who underwent EVAR for aneurysm aortic aneurysm; 12 patients (mean age of 76.1; range 66-88) who underwent open repair for endotension were retrospectively analyzed. The anatomical characteristics of the aorta and surgical findings were reviewed. The rates of early and late procedural complications, and overall mortality were evaluated.

RESULTS

The median interval between the EVAR and surgical conversion was 45.9 months (range 17.1-46.9). Three of the twelve patients underwent emergency surgery due to aneurysm rupture. The median aneurysm sac size, the proximal neck diameter, and the proximal neck length before EVAR were 64 mm, 23.5 mm, and 30.5 mm, respectively, that changed before open repair to 93.5 mm (p = .02), 25 mm (p = .011), and 23 mm (p = .003), respectively. In four of the twelve patients, radiographically undetected endoleak was identified during surgery to be Type Ia, Ib, II, and III, respectively. The rates of early and late procedural complications, and overall mortality were 8.3%, 8.3% and 8.3%, respectively.

CONCLUSIONS

Patients with endotension have a risk of delayed endoleak and aneurysm rupture; secondary intervention should be performed in such cases to prevent fatal complications. Surgical treatment appears to be a curative treatment for endotension with favorable outcomes. In addition, the possibility of an undetected endoleak should be considered as a potential cause of endotension.

Continuous Flow Perfused Cadaver Model for Endovascular Training, Research, and Development

BACKGROUND

Endovascular simulation employing computer, animal, and static models are common and useful adjuncts for teaching endovascular procedures and developing novel, complex endovascular techniques. Unfortunately, these models lack realistic haptic feedback and thus do not faithfully replicate many of the technical challenges associated with clinical endovascular procedures (e.g., arterial calcification, rigidity, and stenosis). We sought to develop a realistic and reproducible perfused cadaver model for endovascular training, device development, and research.

METHODS

Fresh frozen, elderly (age 50-80 years) male cadavers were thawed and prepared for open dissection. The entire arterial tree (ascending aorta to femoral arteries) was dissected free and major branch vessels exposed. Sheaths were placed to allow outflow from selected vessels. A Dacron conduit was sewn to the ascending aorta to generate arterial inflow, which was provided by a centrifugal pump. Aortic aneurysms were created in the descending thoracic and abdominal aorta. Digital subtraction arteriography and various endovascular interventions were performed, including stent grafts and EndoAnchors deployment.

RESULTS

Continuous antegrade flow was achieved in the thoracic, abdominal, iliac, and femoral segments. Open and percutaneous access at the femoral region was obtained with realistic back-bleeding and tactile feedback. Adequate, fluoroscopically documented flow was observed in both cannulated major and noncannulated smaller branches. We performed angiography with standard techniques via a pigtail catheter and contrast injector throughout the arterial system. Abdominal and thoracic endografts were deployed with appropriate angiographic guidance and realistic haptic feedback for both guidewire and stent grafts. Additional applications, including selective cannulation, aorto-iliac occlusive disease interventions, and anchor placement, were also successfully simulated. Finally, the model was used as a platform to test investigational devices.

CONCLUSIONS

Our pressurized cadaver flow model successfully replicated multiple aspects of advanced endovascular procedures with haptic feedback. This novel human cadaver model allows for training and device development under clinically realistic conditions.