Use of the ClotTreiver system (Inari Medical) for the treatment of lower extremity deep vein thrombosis (DVT) has demonstrated safety and efficacy, especially in “removing large volumes of lower extremity acute thrombus in a single session”. A retrospective review of patients treated with the device also concluded that ClotTriever is a good option for specialists alongside other existing therapies.
Writing in the Journal of Vascular Surgery: Venous and Lymphatic Disorders, Jaime Benarroch-Gampel (Emory University, Atlanta, USA) and colleagues explain that while “early clot removal is facilitated by the use of percutaneous mechanical thrombectomy devices”, current methods vary in technical success and, in some cases, “are limited by the concomitant need for thrombolytics”.
“An alternative percutaneous venous thrombectomy system may be helpful in the management of lower extremity DVT without the concomitant use of thrombolytics,” state the authors, underlining what prompted their investigation into the ClotTriever device. The review, which recorded patient characteristics, initial presentation and perioperative course, extracted outcomes from clinical record and established the rate of technical success, defined as “complete clot evacuation after intervention”.
With the help of an institutional database, patients treated for lower extremity DVT with the ClotTriever device —between May and December 2018—were analysed. Patients who presented with thrombosis of the femoropopliteal segments were typically excluded, “with the exception of one patient with terminal cancer whose clinical case required thrombectomy for quality of life after a multidisciplinary discussion with the patient and family”. Ultimately, twelve patients were included in Benarroch-Gampel et al’s study, 50% of whom (n=6) were female. Furthermore, the cohort had a mean age of 55.6 years.
Detailing the characteristics of the cohort further, the authors write: “Two patients (16.7%) presented with chronic asymptomatic DVT, who developed acute symptoms from a recurrent iliofemoral DVT over the days before presentation. One patient (8.4%) presented with phlegmasia cerulea dolens, with the remaining patients presenting with disabling pain and swelling.”
Immediately following preoperative evaluation by the vascular surgery service, patients started on heparin and were anticoagulated throughout their procedure. In order to maintain therapeutic levels during the case, additional boluses of heparin were also given as needed. Postoperatively, compression therapy was applied to the affected leg(s), and heparin continued before transitioning to direct-acting anticoagulation on postoperative day zero or one.
Adding that access was obtained via the popliteal vein in 11 patients, and the small saphenous vein in one patient, Benarroch-Gampel et al reveal that complete clot evacuation was obtained in all patients in a single session, without repeat interventions. Moreover, “symptom resolution before discharge was achieved in 100% of cases”.
In terms of potential complications, the investigators note that there was no incidence of postoperative anaemia or acute kidney failure, while the average length of stay for this cohort of patients was two days, “without the need for intensive care admission”. “At early follow-up, 11 patients (91.7%) continued to report significant symptom resolution. Two of 10 patients (20%) developed recurrent occlusive DVTs on follow-up duplex ultrasound examination,” they add.
Regarding possible limitations of the review, the authors emphasise that this study “is limited by several factors inherent to its design”. They state: “The retrospective nature of our study, as well as [the] lack of a control group, prevents us from establishing widely generalisable conclusions. The study included all patients that presented with symptomatic, iliofemoral DVT, but did not have a standardised assessment of outcomes, which limits the generalisability of our results. In addition, this device cannot be used in complicated cases, such as patients with a thrombosed inferior vena cava (IVC) filter.
Finally, Benarroch-Gampel et al summarise that “the ClotTriever System is safe and effective for removing lower extremity acute deep vein thrombus in a single session, without the need for overnight thrombolysis or ICU [intensive care unit] admission”. “Further studies are warranted to confirm outcomes for longer follow-up,” they conclude.