According to a study published in the February 2007 issue of the Journal of Vascular Surgery, the EndoSure Sensor Wireless AAA pressure measurement system (CardioMEMS) that monitors blood pressure in an aneurysm sac is safe and useful in guiding endovascular repair of an abdominal aortic aneurysm (AAA).
The results are from the Acute Pressure Measurement to Confirm Aneurysm Sac EXclusion (APEX) trial, a prospective, non-randomized study used acute wireless pressure measurements to confirm aneurysm sac exclusion and to determine if intraoperative pressure measurements obtained with the sensor correlated with angiography findings during and at the completion of stent graft placement. Seventy-six patients from 12 clinical centers were studied.
The accuracy of the sensor measurement was confirmed by comparing measurements obtained with an angiographic catheter. In addition, the sensor data and the angiographic findings were in agreement as to the presence of serious endoleaks in 92% of the cases. Through the 30-day follow-up period there were no device related safety issues.
Currently, surgeons use contrast dye injection and X-ray imaging to monitor endoleaks, but the technique is not foolproof. According to the researchers, these methods have an inability to quantify the significance of the endoleak. Also, artifacts caused by bowel gas may mimic an endoleak and thus may lead to misdiagnosis. Repeated contrast injection, which are required for angiography can also impair renal function.
“One downside to the endovascular approach is the occurrence of an endoleak,” commented Dr Takao Ohki, professor and chief in the vascular surgery department of Jikei University School of Medicine, Toyko, and professor of surgery at Albert Einstein College of Medicine, North Shore/LIJ Hospital in Long Island, NY “This trial demonstrates that this wireless sensor for aneurysm sac measurement is safe and feasible, and can be used to diagnose the location and type of endoleak during endovascular aneurysm repair,” he added.
Future studies will focus on using sac pressure monitoring as an alternative to computed tomography for long-term aneurysm surveillance.