Comparison of ultrasonography, computed tomography, and magnetic resonance imaging with intraoperative measurements in the evaluation of abdominal aortic aneurysms

ACR Appropriateness Criteria® Thoracoabdominal Aortic Aneurysm or Dissection: Treatment Planning and Follow-Up

As the incidence of thoracoabdominal aortic pathology (aneurysm and dissection) rises and the complexity of endovascular and surgical treatment options increases, imaging follow-up of patients remains crucial. Patients with thoracoabdominal aortic pathology without intervention should be monitored carefully for changes in aortic size or morphology that could portend rupture or other complication. Patients who are post endovascular or open surgical aortic repair should undergo follow-up imaging to evaluate for complications, endoleak, or recurrent pathology. Considering the quality of diagnostic data, CT angiography and MR angiography are the preferred imaging modalities for follow-up of thoracoabdominal aortic pathology for most patients. The extent of thoracoabdominal aortic pathology and its potential complications involve multiple regions of the body requiring imaging of the chest, abdomen, and pelvis in most patients. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Pseudoaneurisma roto de artéria ileocólica: relato de caso

Visceral artery aneurysms (VAAs) and visceral artery pseudoaneurysms (VAPAs) are rare conditions and are potentially lethal when they rupture. They are usually found as incidental findings on computed tomography (CT) scans of asymptomatic patients. Although conventional open surgery is currently considered the gold standard treatment, the endovascular approach has gained prominence as a minimally invasive procedure with lower surgical risk. In this approach, use of coil embolization in saccular VAAs and VAPAs and implantation of flow-modulating stents constitute alternative treatments for fusiform aneurysms. We present the case of a 51-year-old female patient complaining of acute abdominal pain, tachycardia, and hypotension, with evidence of abdominal bleeding on CT angiography, who was diagnosed with a ruptured ileocolic artery (ICA) pseudoaneurysm. She underwent early endovascular treatment for ICA embolization, which was successful and achieved clinical improvement.

Impact of endovascular technique in vascular surgery training at a large university hospital in Brazil

OBJECTIVES

The aim of this study was to determine the impact of endovascular surgery versus open vascular technique training in a Brazilian teaching service.

DESIGN

Cross-sectional study.

SETTING

Hospital das Clinicas-Faculty of Medicine-University of Sao Paulo, a tertiary institutional hospital-Brazil.

PARTICIPANTS

We reviewed 1,040 arterial operations performed during 2 distinct time periods: January 1995 to December 1996, and January 2006 to December 2007. Based on the disease treated, the procedures were classified into the following 5 groups: abdominal aortic aneurysms (AAA), aorto-iliac obstructive disease (AI), obstructive disease of the femoropopliteal-tibial segment (FP), carotid disease (C), and others (O). The operations were also divided into an endovascular surgery (ES) group and an open surgery (OS) group. We compared the number of open and endovascular procedures for each arterial disease group during both periods.

RESULTS

During the 2006-2007 period, 654 patients were treated surgically, whereas over the 1995-1996 period, 386 arterial operations were performed. A significant increase in endovascular procedures (p < 0.001) was found from the 1995-1996 period to the 2006-2007 period (35 vs 351, respectively) in all groups, whereas open surgery showed a slight increase in the number of procedures in the AAA and O groups only. In the 1995-1996 period, OS was the primary surgical method for all groups, but in the 2006-2007 time frame, OS was performed more frequently than ES only in the AAA and O groups. Considering all vascular disease groups, OS was the technique used in 90.9% (351 of 386) of the operations during 1995-1996, whereas in 2006-2007, OS was performed in only 46.3% (303 of 654) of the procedures.

CONCLUSIONS

The increase in the number of ES observed over the past decade has had little impact on OS procedures performed at our medical center, not bringing harm to open surgical training.

Imaging in endovascular therapy: our future

The endovascular therapist now has many modern imaging techniques available to plan and execute treatment, whereas in the past vascular surgeons relied mostly on clinical examination and arteriography. Advances in computer technology have enabled fast acquisition and processing of the large amounts of digital data essential to capture the dynamic information from fast-flowing blood at high resolution. Functional imaging has begun to play a role in predicting stability of progressive vascular disease and the need for and risks of intervention. Computing power now affords the interventionist the ability to handle imaging data in powerful 3-dimensional programs and electronically "in-lay" a variety of devices to plan complex endovascular procedures from the familiar platform of a laptop. In four major clinical areas, carotid intervention, peripheral intervention, endoluminal grafting, and cardiac imaging, we review the latest advances and changes with an eye toward how we should best be using imaging in our patients undergoing endovascular treatment...now and into the future.

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

OBJECTIVE

To measure the pulsatility of human aneurysms before and after complete exclusion with an endograft.

METHOD

Five aortic aneurysms obtained during necropsy were submitted to pulsatile perfusion before and after implantation of a bifurcated endograft. The specimens were contained in a closed chamber filled with saline solution. A vertical tube attached to the chamber was used to measure volume dislocation in each systole. Mural thrombus was kept intact, and the space around the device was filled with human blood. After each experiment, the aneurysm was opened to check for the correct positioning and attachment of the device.

RESULTS

The level of the saline column oscillated during pulsation in each case, with respective amplitudes of 17, 16, 13, 7, and 25 cm before the endograft insertion. After the insertion, the amplitudes dropped to 13, 12, 9, 3.5, and 23 cm, respectively. The differences were not significant. During the post-experimental examination, all devices were found to be in position and well attached to the neck and iliacs. No endoleak was detected during perfusion or by visual inspection.

CONCLUSION

Pulsation of an endograft is transmitted to the aneurysm wall even in the absence of endoleak, and should not be interpreted as procedural failure.

Follow-up of the aneurysmal sac after exclusion and bypass of popliteal artery aneurysms

Popliteal artery aneurysms are frequent and may lead to thromboembolic events and limb loss.

PURPOSE

To evaluate clinical and ultrasonographic follow-up of patients who underwent exclusion of a popliteal artery aneurysm using the technique proposed by Edwards.

METHODS

Data of all patients who underwent surgery to repair a popliteal artery aneurysm at Hospital das Clinicas, the São Paulo University Medical School between 1996 and 2004 were reviewed. Inclusion criteria were repair with aneurysm exclusion and bypass using the technique proposed by Edwards, as well as the existence of preoperative and postoperative measurements of the aneurysmal sac.

RESULTS

Data of 16 patients who underwent 20 procedures for popliteal artery aneurysm exclusion and bypass were available to analysis. The preoperative diameter of the popliteal artery aneurysms ranged from 1.3 cm to 6.1 cm (mean = 3.1 cm). Patients underwent duplex ultrasound scanning 1 month to 7 years after surgical repair. Follow-up of the 20 cases revealed that 10 aneurysms exhibited decreased mean transverse diameters, ranging from 0.2 to 2.3 cm, while 7 had increased in diameter, ranging 0.3 to 3.3 cm, and 3 remained unchanged. Flow was observed only in 5 out of the 20 procedures, 3 of which (60%) had increased diameters.

CONCLUSION

Although exclusion is a widely accepted procedure for the repair of popliteal artery aneurysms, data in the literature and the results of this study, which did not include cases of rupture or compression, suggest that strict follow-up of patients who undergo aneurysm exclusion is necessary.