Ultrasound-guided thrombin injection of iatrogenic pseudoaneurysm at a community hospital

Do not underestimate the femoral pseudoaneurysm

Abstract. In addition to haematoma and arteriovenous fistula, the iatrogenic pseudoaneurysm is a common complication of vascular access that is caused by a perforation in the arterial wall. Iatrogenic pseudoaneurysms can progress in size and lead to rupture and active bleeding. Over the previous few decades, therapeutic methods have evolved from surgical repair to less invasive options, such as ultrasound-guided compression therapy (UGCT) and ultrasound-guided thrombin injection (UGTI). This paper presents an overview of the diagnostic and treatment modalities used in femoral pseudoaneurysms as well as a comprehensive summary of previous studies that analysed the success and complication rates of UGCT and UGTI.

Selective use of Duplex Ultrasound after Successful Thrombin Injection of Pseudoaneurysms

Introduction

Duplex-guided thrombin injection (DGTI) has been shown to be a safe and efficacious initial treatment of iatrogenic arterial pseudoaneurysms. Postinjection follow-up duplex ultrasound examination has become the accepted standard of care despite 1) the use of intraprocedural ultrasonography to monitor successful thrombosis, 2) a low post-DGTI recurrence rate, and 3) the relatively high cost of ultrasonography. A retrospective study of DGTI at our institution was conducted to examine the necessity of routine duplex ultrasound after successful DGTI, along with a review of the relevant literature.

Patient Population/Methods

A retrospective review was conducted of 82 patients with iatrogenic arterial pseudoaneurysms (12 complex; 25.6%) treated with DGTI after initial diagnostic duplex ultrasonography. Immediate routine follow-up duplex ultrasound was performed on 71 of 82 cases (86.6%), whereas 11 patients received only clinical follow-up at the surgeon's discretion. Patient demographics, pseudoaneurysm anatomy, procedural details, outcomes, and complications were retrospectively documented and analyzed.

Results

From January 2002 to November 2003, 82 patients (59.8% women) underwent DGTI for pseudoaneurysm, with the majority located in the common femoral artery (48 of 82; 58.5%). Eighty pseudoaneurysms (97.6%) were treated with DGTI, with 78 (95.1%) being initially successful. Four of 78 (5%) follow-up examinations were judged to be of clinical significance: 2 of 78 patients (2.6%) became symptomatic and experienced pseudoaneurysm recurrence, whereas 2 of 78 patients were found to have an additional, previously undocumented, pseudoaneurysm. Three of these four resolved with a second injection, whereas one resolved without additional treatment. No thromboembolic, allergic, or infectious complications related to DGTI occurred.

Conclusions

In concert with the available literature, this cohort confirms that DGTI is a safe and effective treatment of iatrogenic arterial pseudoaneurysms with a low rate of recurrence, complication, and need for conversion to surgical intervention. DGTI should undoubtedly be the initial treatment of choice for pseudoaneurysms; however, follow-up duplex ultrasonography can be reserved for the clinically symptomatic patient.

Femoral Pseudoaneurysms

Iatrogenic pseudoaneurysms will continue to be a problem associated with arterial cannulation procedures. With the increasing trend toward minimally invasive procedures, vascular surgeons, as well as interventionalists will be performing more cannulation procedures; hence we will be more involved in the management of this complication more frequently. Treatment trends and efforts aimed at preventing iatrogenic pseudoaneurysms have evolved over the past decade. This article reviews the history and available literature on the subject, in conjunction with the experience of a center that performs over 10,000 cannulation procedures annually.

Reducing duplex examinations in patients with iatrogenic pseudoaneurysms

OBJECTIVE

Ultrasound-guided thrombin injection has become the initial treatment of choice for femoral access-related pseudoaneurysms. Patients typically undergo serial duplex examinations to assess for spontaneous resolution of small iatrogenic pseudoaneurysms (IPSAs) (<2.5 cm), or may require repeated diagnostic, therapeutic, and follow-up studies for larger IPSAs (>2.5 cm). We evaluated the impact of a revised treatment algorithm that includes primary treatment of both small (<2.5 cm) and larger pseudoaneurysms (>2.5 cm), rather than observation of smaller ones, and attempts to establish a single duplex examination via a point-of-care treatment strategy.

METHODS

We reviewed 105 consecutive patients treated with ultrasound-guided thrombin injection from July 2001 through September 2004. Patient, IPSAs, characteristics, and treatment methods were examined. The number of duplex examinations per patient was evaluated over the treatment interval. Also, published cost data were used to compare primary treatment of small ISPAs vs observation with serial duplex examinations.

RESULTS

Successful thrombosis occurred in 103 (98.1%) of 105 treated pseudoaneurysms. No minor or major complications occurred after thrombin injection in either small or large ISPAs, and both failures requiring operation were in the large aneurysm group. The recurrence rate for the series was 1.9% (2/105), and both recurrences were successfully treated with an additional thrombin injection. A single injection was successful in treating 43 (97.7%) of 44 small (<2.5 cm) IPSAs, and one required a second injection. Patients had an average of 3.3 duplex examinations in our first year of treatment experience, which declined to 1.5 by our third year with the institution of a point-of-care service model for all pseudoaneurysms. Based on this decreased use of duplex examination and an average treatment cohort of 35 IPSA patients per year our institution, we determined this results in a reduction of 35 hours of laboratory time and nearly 70 ultrasounds per year. Similarly for small pseudoaneurysms, a point-of-service primary treatment program rather than observation results in an estimated cost savings of $12,000, based on treating 15 small IPSAs per year.

CONCLUSIONS

Ultrasound-guided thrombin injection is safe and effective for the treatment of nearly all iatrogenic pseudoaneurysms. We recommend primary treatment of small pseudoaneurysms by ultrasound-guided thrombin injection rather than observation with serial duplex scans. A point-of-care treatment algorithm can result in cost savings by reducing the number of necessary duplex examinations.

Femoral Artery Pseudoaneurysms: Risk Factors, Prevalence, and Treatment Options

Femoral artery pseudoaneurysms (PSA or false aneurysm) develop in about 1% of patients undergoing procedures that require femoral artery cannulation. PSA prolong hospitalization, consuming health-care resources, and result in significant morbidity. We designed a study to review the prevalence, risk factors, and treatment of PSA. We performed a retrospective, case-controlled study of patients diagnosed with PSA at a large, urban, tertiary-care teaching hospital. We reviewed 48 patients with PSA for our study. The estimated prevalence of PSA was 0.28%, with identical rates found for procedures done in the interventional radiology department and in the cardiac catheterization suite. Logistic regression identified three independent risk factors for developing PSA: being female (odds ratio 2.62), having an intervention performed (odds ratio 3.22), and not having a closure device used (odds ratio 10.2). Patients with PSA had longer hospital length of stay than that of patients without PSA. We found no statistically significant difference in failure or complication rates for the four treatment options and that spontaneous resolution of PSA does not correlate with its size. Thrombin injection and observation are effective, low-complication treatment options.