Translumbar Type II Endoleak Repair Using Angiographic CT

Embolization of Type 2 Endoleaks in the Abdominal Aorta Using Ethylene Vinyl Alcohol Copolymer

BACKGROUND

 Type 2 endoleaks (T2EL) are the most frequent complication following endovascular aortic repair. Multiple studies primarily deal with the technical and clinical success of the embolization of persisting T2EL, thereby revealing controversial outcomes. Current reports rarely focus on the detailed execution of such a complex interventional procedure with respect to the difficult anatomic setting.

METHODS

 The present review provides an in-depth depiction and evaluation of the interventional methodology of the embolization of T2EL in the abdominal aorta with use of ethylene vinyl alcohol copolymer (EVOH). Complicating anatomic conditions are taken into account as well as technical and clinical success rates.

RESULTS

 Using the transarterial approach, there are at least 4 different pathways to access the nidus of a T2EL. CT-guided direct puncture of the aneurysm sac provides an alternative method of high technical success. EVOH with its slow solidification characteristics enables good control to achieve complete filling of the T2EL. During the intervention, however, it remains difficult to meet exactly the embolization endpoint, especially in large T2ELs.

CONCLUSION

 T2EL embolization using EVOH is an effective treatment with low major complication rates when conducted by skilled interventionists with detailed knowledge of diverse complex access routes.

KEY POINTS

  · Many roads lead to Rome to access the nidus of a T2EL including diverse complex transarterial pathways and direct aneurysm sac puncture.. · Ethylene vinyl alcohol co-polymer enables good control for slow filling of the nidus with low risk of major complications.. · Identification of the embolization endpoint remains difficult during the procedure and may result in secondary interventions.. · Successful T2EL embolization requires detailed knowledge of all access routes to the nidus and skilled handling of liquid embolics..

CITATION FORMAT

· Nolte-Ernsting C, Mecklenbeck F, Stehr A. Embolization of Type 2 Endoleaks in the Abdominal Aorta Using Ethylene Vinyl Alcohol Copolymer. Fortschr Röntgenstr 2021; DOI: 10.1055/a-1502-7883.

Comparison of Cost and Efficacy of Trufill® vs Histoacryl® n-Butyl Cyanoacrylate for Translumbar Type 2 Endoleak Embolization

PURPOSE

The study aimed to compare the cost and efficacy of translumbar approach type 2 endoleak repairs using either Trufill® or Histoacryl® n-BCA liquid embolic.

METHOD AND MATERIALS

This was a retrospective review of patients who had translumbar approach type 2 endoleak repairs using either Trufill® or Histoacryl®. Patients were included if they underwent a technically successful type 2 endoleak repair via a translumbar approach with Trufill® or Histoacryl® n-BCA. A multivariable analysis was performed with the primary clinical outcome of percent change in aneurysm diameter per month compared. Procedure cost was calculated based on typical materials used.

RESULTS

20 Trufill® and 14 Histoacryl® patients were included. The mean procedure cost was higher for Trufill® ($5,757.30 vs. $1,586.09, p ≤ 0.001). There was no significant difference between Trufill® or Histoacryl® patients for age at first embolization, gender, total number of embolizations, number of feeding branches, aneurysm sac size prior to embolization, or residual endoleak at first follow-up. Trufill® patients had more coils used (12.0 vs. 4.3, p = 0.0007), less glue used (0.9 vs. 2.1 mL, p < 0.001), longer follow-up duration (33.5 vs. 13.2 months, p = 0.002), more follow-up CT angiograms (CTA) (3.7 vs. 1.9, p = 0.01), and larger excluded aneurysm sac size at most recent CTA (7.1 cm vs. 5.9 cm, p = 0.04). Percent change in sac diameter per month was not significantly different between Trufill® and Histoacryl® (0.21% vs. -0.25%/month, p = 0.06, respectively). There were no complications.

CONCLUSION

Use of Histoacryl® over Trufill® n-BCA resulted in significantly less procedural cost while maintaining safety and efficacy.

C-arm cone-beam CT: general principles and technical considerations for use in interventional radiology

Digital flat-panel detector cone-beam computed tomography (CBCT) has recently been adapted for use with C-arm systems. This configuration provides projection radiography, fluoroscopy, digital subtraction angiography, and volumetric computed tomography (CT) capabilities in a single patient setup, within the interventional suite. Such capabilities allow the interventionalist to perform intraprocedural volumetric imaging without the need for patient transportation. Proper use of this new technology requires an understanding of both its capabilities and limitations. This article provides an overview of C-arm CBCT with particular attention to trade-offs between C-arm CBCT systems and conventional multi-detector CT.

Extended ellipse-line-ellipse trajectory for long-object cone-beam imaging with a mounted C-arm system

Recent reports show that three-dimensional cone-beam (CB) imaging with a floor-mounted (or ceiling-mounted) C-arm system has become a valuable tool in interventional radiology. Currently, a circular short scan is used for data acquisition, which inevitably yields CB artifacts and a short coverage in the direction of the patient table. To overcome these two limitations, a more sophisticated data acquisition geometry is needed. This geometry should be complete in terms of Tuy's condition and should allow continuous scanning, while being compatible with the mechanical constraints of mounted C-arm systems. Additionally, the geometry should allow accurate image reconstruction from truncated data. One way to ensure such a feature is to adopt a trajectory that provides full R-line coverage within the field-of-view (FOV). An R-line is any segment of line that connects two points on a source trajectory, and the R-line coverage is the set of points that belong to an R-line. In this work, we propose a novel geometry called the extended ellipse-line-ellipse (ELE) for long-object imaging with a mounted C-arm system. This trajectory is built from modules consisting of two elliptical arcs connected by a line. We demonstrate that the extended ELE can be configured in many ways so that full R-line coverage is guaranteed. Both tight and relaxed parametric settings are presented. All results are supported by extensive mathematical proofs provided in appendices. Our findings make the extended ELE trajectory attractive for axially-extended FOV imaging in interventional radiology.

Type II endoleak repair after endovascular abdominal aortic repair using a computed tomography-guided percutaneous transabdominal approach

The current treatment of type II endoleaks includes either transarterial or sac puncture techniques. Sac puncture can be further divided into translumbar, transabdominal, and transcaval approaches.¹ However, transabdominal techniques for the treatment of type II leak are not well established. Herein, we report a case of a type II endoleak repaired in a 76-year-old woman using a computed tomography-guided percutaneous transabdominal approach. This type of transabdominal repair is easy and safe because punctures to the aneurysm sac are visualized in real time by computed tomography. It is possible to selectively embolize persistent blood flow in arteries in either the sac or main artery.

Retrospective Study in 40 Patients of Utility of C-arm FDCT as an Adjunctive Modality in Technically Challenging Image-Guided Percutaneous Drainage Procedures

PURPOSE

To explore the utility of C-arm flat detector computed tomography (FDCT) as an adjunctive modality in technically challenging image-guided percutaneous drainage procedures.

METHODS

Clinical and image data were reviewed on 40 consecutive patients who underwent percutaneous drainage of fluid collections in technically challenging anatomic locations that required the use of C-arm FDCT between 2009 and 2013. Percutaneous drainage was performed under ultrasound and fluoroscopic guidance with the use of C-arm FDCT as a problem-solving tool to identify appropriate needle/wire placement prior to drainage catheter placement (n = 33) or to confirm catheter positioning within the fluid collection (n = 8). Technical success and procedural complications were recorded and retrospectively analyzed.

RESULTS

Forty one fluid collections were identified in 40 patients. Mean number of C-arm FDCT rotational acquisitions per patient was 1.25. Mean procedure time per patient was 59.3 min. Mean fluoroscopy time was 5.5 min, and mean air kerma was 394.3 mGy. Percutaneous drainage with the use of C-arm FDCT was successful in 35 of 40 patients (87.5%). Technical failure was encountered in 5 of 40 patients due to too narrow window (n = 1), too small or no fluid collection noted on C-arm FDCT images (n = 2), and poor image quality requiring the use of a conventional CT scan (n = 2). Three procedure-related complications occurred (7.5%), which included traversed rectum, traversed spleen, and sepsis.

CONCLUSION

C-arm FDCT is useful as an adjunctive modality in the interventional suite for technically challenging percutaneous drainage procedures by providing sufficient anatomic detail. Complications of catheter misplacement can be avoided if C-arm FDCT is used prior to tract dilatation. If C-arm FDCT image quality of needle and/or wire placement is poor, conventional CT guidance is recommended.

Axially extended-volume C-arm CT using a reverse helical trajectory in the interventional room

C-arm computed tomography (CT) is an innovative technique that enables a C-arm system to generate 3-D images from a set of 2-D X-ray projections. This technique can reduce treatment-related complications and may improve interventional efficacy and safety. However, state-of-the-art C-arm systems rely on a circular short scan for data acquisition, which limits coverage in the axial direction. This limitation was reported as a problem in hepatic vascular interventions. To solve this problem, as well as to further extend the value of C-arm CT, axially extended-volume C-arm CT is needed. For example, such an extension would enable imaging the full aorta, the peripheral arteries or the spine in the interventional room, which is currently not feasible. In this paper, we demonstrate that performing long object imaging using a reverse helix is feasible in the interventional room. This demonstration involved developing a novel calibration method, assessing geometric repeatability, implementing a reconstruction method that applies to real reverse helical data, and quantitatively evaluating image quality. Our results show that: 1) the reverse helical trajectory can be implemented and reliably repeated on a multiaxis C-arm system; and 2) a long volume can be reconstructed with satisfactory image quality using reverse helical data.

Endoleaks after endovascular abdominal aortic aneurysm repair: what one needs to know

PURPOSE OF REVIEW

To review the current state of diagnosis, treatment, and outcomes of the different types of endoleaks after endovascular abdominal aortic aneurysm repair (endovascular aneurysm repair, EVAR).

RECENT FINDINGS

Endoleaks are the most frequent complication after EVAR, the most common indication for secondary interventions, and the most common cause of rupture after EVAR. Imaging is critical for detecting endoleaks. Type I and III endoleaks require urgent intervention to prevent aneurysm rupture. Intervention for other endoleaks or endotension is indicated if the aneurysm sac continues to grow during follow-up. The majority of endoleaks can be treated with endovascular techniques. Open surgical conversion may be considered if the risk of aneurysm rupture is high and if no endovascular options are available or if they have failed.

SUMMARY

Endoleaks continue to be a challenge and this article discusses the different treatment options for endoleaks after EVAR. Long-term follow-up after EVAR is required to diagnose and treat endoleaks before they result in aneurysm rupture. The majority of endoleaks can be treated with endovascular techniques, although open surgical interventions may be required in selected patients.

The place of endovascular treatment in abdominal aortic aneurysm

BACKGROUND

The endovascular treatment of abdominal aortic aneurysms has become more common. A careful comparison of this technique with the established treatment by open surgery is needed before it can be more widely adopted.

METHODS

We selectively searched the Medline database for articles on the endovascular treatment of abdominal aortic aneurysms, with special attention to prospective, randomized trials comparing it to open aortic surgery (keywords: "endovascular abdominal aortic repair" and "prospective randomized trial").

RESULTS

Data on 30-day mortality and long-term survival are now available from four randomized multicenter trials. In three of these trials, endovascular treatment was found to lower 30-day mortality by two-thirds (endovascular: 0.2% to 1.7%, open repair: 0.7% to 4.7%), but this difference in survival was no longer present at two years. Compared to open open aortic surgery, endovascular treatment has a higher long-term complication rate. Endoleakage (perigraft leakage) accounted for more than 30% of complications and was the commonest reason for reintervention and unsuccessful intervention; in nearly all cases, it was successfully treated by the endovascular route. The rate of secondary aortic rupture was 0.8%, and migration of the prosthesis occurred in 5% of cases. Follow-up checks of the stent graft are now recommended at 3, 6 and 12 months after implantation, and annually thereafter.

CONCLUSION

Prospective randomized trials have shown that the endovascular technique lowers perioperative mortality. In the long term, however, it has a higher complication rate than open aortic surgery and leads to more frequent reintervention.

Diagnostic accuracy of C-arm CT during selective transcatheter angiography for hepatocellular carcinoma: comparison with intravenous contrast-enhanced, biphasic, dynamic MDCT

PURPOSE

This study was aimed to compare the accuracy, sensitivity, and positive predictive value of C-arm CT (CACT) during selective transcatheter angiography with those of multidetector CT (MDCT) in the detection of hepatocellular carcinoma (HCC).

MATERIAL AND METHODS

In this prospective study, 30 patients (mean age, 73 years) with unresectable HCC were examined with CACT before chemoembolisation. Images of a combination of CACT during arterial portography (CACTAP) and dual-phase CACT during hepatic arteriography (CACTHA) was obtained and images of intravenous contrast-enhanced, biphasic, dynamic, MDCT was also obtained beforehand. Three blinded observers independently reviewed CACT and MDCT. Diagnostic accuracy was evaluated by the alternative free-response receiver operating characteristic (AFROC) method. Sensitivities and positive predictive values (PPV) were analyzed with the paired t-test.

RESULTS

In the mean area under the AFROC curve (Az), there was no significant difference between MDCT and CACT (MDCT, mean Az value, 0.83; CACT, 0.85, respectively) (P = 0.32). There was also no significant difference between the two techniques in sensitivity (MDCT, mean 0.65; CACT, 0.60) and PPV (MDCT, mean 0.98; CACT, 0.97) (P = 0.40, P = 0.68, respectively).

CONCLUSION

The diagnostic accuracy of CACT was equivalent to that of biphasic CT in the diagnosis of HCC.

KEY POINTS

C-arm CT helps detection of hepatocellular carcinoma (HCC) during interventional (TACE) treatment. C-arm CT for HCC seemed just as accurate as biphasic CT. TACE can be performed with greater confidence using C-arm CT.

Iatrogenic Ureteral Injury during Translumbar Embolization of a Type II Endoleak

The persistence of flow within an aneurysm sac remains the so-called Achilles heel of endovascular aortic aneurysm repair. The management of type II endoleaks remains controversial, although aneurysm sac expansion is an accepted indication for intervention. The present case describes a patient with a type II endoleak following endovascular repair of an abdominal aortic aneurysm treated by translumbar embolization. The procedure was complicated by iatrogenic injury to the left ureter and nontarget embolization resulting in acute ureteral obstruction.

Use of angiographic CT imaging in the cardiac catheterization laboratory for congenital heart disease

OBJECTIVES

This study sought to retrospectively evaluate our initial experience using angiographic computed tomography (ACT) in a pediatric cardiac catheterization laboratory.

BACKGROUND

ACT provides cross-sectional CT images from a rotational angiography run using a C-arm mounted flat-panel detector in the interventional suite. A 3-dimensional (3D) angiographic image can be created from the CT volume set and used in real time during the procedure. To our knowledge, its use has never previously been described for congenital heart disease.

METHODS

3D reconstructions were created and we retrospectively reviewed cases during our first year of ACT use. Images obtained were independently evaluated to determine their diagnostic utility. Radiation dose reduction protocols were defined using phantom testing and radiation dose calculation.

RESULTS

ACT was used during 41 cardiac catheterizations in patients at a median age of 5.1 years (range: 0.4 to 58.8 years) for evaluation of: right ventricular outflow tract (RVOT)/central pulmonary arteries (PAs) in 20; cavopulmonary connection (CPC) in 11; pulmonary veins in 5; distal PAs in 4; and other locations in 5. Four subjects had 2 anatomic areas studied by ACT. The mean contrast volume for ACT was 1.2 ± 0.4 ml/kg. Diagnostic-quality imaging was obtained in 71% of cases: 13/20 RVOT/central PAs; 9/11 CPC; 4/5 pulmonary veins; 2/4 distal PAs; and 4/5 others. In 12 cases, ACT contributed to clinical outcomes beyond standard angiography. Radiation dose reduction protocols allowed ACT to be comparable in exposure to a standard biplane cineangiogram.

CONCLUSIONS

Diagnostic-quality imaging can be obtained using ACT in 71% of cases without a significant increase in contrast or radiation exposure. In certain cases, ACT provides additional anatomic detail and may aid complex catheter manipulations. Future work is needed to continue to define applications of this new technology.

Cyanoacrylate embolization of endoleaks after abdominal aortic aneurysm repair

INTRODUCTION

Type II endoleaks occur in up to a fifth of endoluminal repairs for abdominal aortic aneurysms and are commonly treated when aortic sac expansion can be demonstrated. Technical failure is common when catheter-guided particulates or coil embolic agents are used. Presented here is a feasibility study using catheter-directed N-butyl-2-cyanoacrylate (Histoacryl, Braun, Tuttlingen, Germany) embolotherapy.

METHOD

A retrospective review of the case notes of patients undergoing embolization procedures for type II endoleaks with expanding sacs was performed from this centre's cohort of endoluminal aortic repair patients under surveillance. Data on patients with type II endoleaks who were treated with either or both cyanoacrylate and coil embolization were extracted. The outcomes were then compared.

RESULTS

In total, five cases were identified, and four of these cases had both coil and glue embolization. Technical success was defined as endoleak closure proven on follow-up computed tomographic imaging. Technical success was achieved in all four patients treated with intra-sac cyanoacrylate. One case treated initially with coil embolization was successful. All patients had a computed tomographic scan at 3 months. One minor complication occurred that resolved without treatment.

DISCUSSION

Type II endoleaks after EVAR with expanding sacs require treatment. Percutaneous catheter-directed cyanoacrylate embolization offers an alternative to coil or particulate embolization and, in this series, was found to be more likely to result in endoleak closure.

Percutaneous transabdominal approach for the treatment of endoleaks after endovascular repair of infrarenal abdominal aortic aneurysm

Objective

The purpose of this study was to evaluate the technical feasibility and clinical efficacy of percutaneous transabdominal treatment of endoleaks after endovascular aneurysm repair.

Materials and Methods

Between 2000 and 2007, six patients with type I (n = 4) or II (n = 2) endoleaks were treated by the percutaneous transabdominal approach using embolization with N-butyl cyanoacrylate with or without coils. Five patients underwent a single session and one patient had two sessions of embolization. The median time between aneurysm repair and endoleak treatment was 25.5 months (range: 0-84 months). Follow-up CT images were evaluated for changes in the size and shape of the aneurysm sac and presence or resolution of endoleaks. The median follow-up after endoleak treatment was 16.4 months (range: 0-37 months)

Results

Technical success was achieved in all six patients. Clinical success was achieved in four patients with complete resolution of the endoleak confirmed by follow-up CT. Clinical failure was observed in two patients. One eventually underwent surgical conversion, and the other was lost to follow-up. There were no procedure-related complications.

Conclusion

The percutaneous transabdominal approach for the treatment of type I or II endoleaks, after endovascular aneurysm repair, is an alternative method when conventional endovascular methods have failed.

Detection of hepatocellular carcinoma by CT during arterial portography using a cone-beam CT technology: comparison with conventional CTAP

BACKGROUND

To evaluate the detectability of hepatocellular carcinoma (HCC) by computed tomography during arterial portography (CTAP) using cone-beam CT technology (CBCTAP) by comparing it with conventional CTAP.

METHODS

Forty-four HCC lesions (mean diameter 1.9 +/- 1.1 cm) of 24 patients who sequentially underwent conventional CTAP and CBCTAP during the same angiography session were evaluated. CBCTAP findings of each tumor were classed into three grades as compared to conventional CTAP: optimal; suboptimal; and nondiagnostic.

RESULTS

All CBCTAP images had image artifacts from the catheter placed in the superior mesenteric artery and enhanced portal veins. Additionally, the contrast between HCC lesion and surrounding liver parenchyma of CBCTAP images was less than that of CTAP images. Of the 44 tumors, findings of 31 nodules (mean 2.2 +/- 1.2 cm) (70.5%) were classed as optimal. Eight nodules (mean 1.4 +/- 0.8 cm) (18.2%) were classed as suboptimal. Five nodules (mean 1.0 +/- 0.1 cm) (11.4%) including two located in the outside of field of view were classed as nondiagnostic.

CONCLUSION

CBCTAP had sufficient image quality to detect almost all small HCC lesions compared to conventional CTAP and could depict approximately 89% of HCC nodules, including eight suboptimal lesions.

Three-dimensional C-arm cone-beam CT: applications in the interventional suite

C-arm cone-beam computed tomography (CT) with a flat-panel detector represents the next generation of imaging technology available in the interventional radiology suite and is predicted to be the platform for many of the three-dimensional (3D) roadmapping and navigational tools that will emerge in parallel with its integration. The combination of current and unappreciated capabilities may be the foundation on which improvements in both safety and effectiveness of complex vascular and nonvascular interventional procedures become possible. These improvements include multiplanar soft tissue imaging, enhanced pretreatment target lesion roadmapping and guidance, and the ability for immediate multiplanar posttreatment assessment. These key features alone may translate to a reduction in the use of iodinated contrast media, a decrease in the radiation dose to the patient and operator, and an increase in the therapeutic index (increase in safety-vs-benefit ratio). In routine practice, imaging information obtained with C-arm cone-beam CT provides a subjective level of confidence factor to the operator that has not yet been thoroughly quantified.

Thoracic endoleak embolization using a direct percutaneous puncture of the endoleak through lung parenchyma

An 84-year-old patient presented with an endoleak after endovascular repair of a ruptured thoracic aortic aneurysm. The endoleak was thought to be a type II endoleak on computed tomographic (CT) angiography and was not visualized on angiography. The endoleak was accessed via direct puncture of the endoleak sac through the pleura and lung parenchyma with use of fluoroscopic and C-arm CT guidance. The endoleak was embolized with platinum coils and n-butyl cyanoacrylate with no complications. Follow-up imaging with CT angiography at 43 days revealed no recurrent endoleak.

Usefulness of cone-beam computed tomography during ultraselective transcatheter arterial chemoembolization for small hepatocellular carcinomas that cannot be demonstrated on angiography

This study evaluated the usefulness of cone-beam computed tomography (CBCT) during ultraselective transcatheter arterial chemoembolization (TACE) for hepatocellular carcinomas (HCC) that could not be demonstrated on angiography. Twenty-eight patients with 33 angiographically occult tumors (mean diameter 1.3 +/- 0.3 cm) were enrolled in the study. The ability of CBCT during arterial portography (CBCTAP), during hepatic arteriography (CBCTHA), and after iodized oil injection (LipCBCT) to detect HCC lesions was retrospectively analyzed. The technical success of TACE was divided into three grades: complete (the embolized area included the entire tumor with at least a 5-mm wide margin), adequate (the embolized area included the entire tumor but without a 5-mm wide margin in parts), and incomplete (the embolized area did not include the entire tumor) according to computed axial tomographic (CAT) images obtained 1 week after TACE. Local tumor progression was also evaluated. CBCTAP, CBCTHA, and LipCBCT detected HCC lesions in 93.9% (31 of 33), 96.7% (29 of 30), and 100% (29 of 29) of patients, respectively. A single branch was embolized in 28 tumors, and 2 branches were embolized in five tumors. Twenty-seven tumors (81.8%) were classed as complete, and 6 (18.2%) were classed as adequate. None of the tumors were classed as incomplete. Twenty-five tumors (75.8%) had not recurred during 12.0 +/- 6.2 months. Eight tumors (24.2%), 5 (18.5%) of 27 complete success and 3 (50%) of 6 adequate success, recurred during 10.1 +/- 6.2 months. CBCT during TACE is useful in detecting and treating small HCC lesions that cannot not be demonstrated on angiography.

Intraoperative DynaCT detection and immediate correction of a type Ia endoleak following endovascular repair of abdominal aortic aneurysm

Reintervention following endovascular aneurysm repair (EVAR) is required in up to 10% of patients at 30 days and is associated with a demonstrable risk of increased mortality. Completion angiography cannot detect all graft-related anomalies and computed tomographic angiography is therefore mandatory to ensure clinical success. Intraoperative angiographic computed tomography (DynaCT; Siemens, Germany) utilizes cone beam reconstruction software and flat-panel detectors to generate CT-like images from rotational angiographic acquisitions. We report the intraoperative use of this novel technology in detecting and immediately treating a proximal anterior type Ia endoleak, following an endovascular abdominal aortic repair, which was not seen on completion angiography. Immediate evaluation of cross-sectional imaging following endograft deployment may allow for on-table correction of clinically significant stent-related complications. This should both improve technical success and minimize the need for early secondary intervention following EVAR.

C-arm cone-beam CT: general principles and technical considerations for use in interventional radiology

Digital flat-panel detector cone-beam computed tomography (CBCT) has recently been adapted for use with C-arm systems. This configuration provides projection radiography, fluoroscopy, digital subtraction angiography, and volumetric computed tomography (CT) capabilities in a single patient setup, within the interventional suite. Such capabilities allow the interventionalist to perform intraprocedural volumetric imaging without the need for patient transportation. Proper use of this new technology requires an understanding of both its capabilities and limitations. This article provides an overview of C-arm CBCT with particular attention to trade-offs between C-arm CBCT systems and conventional multi-detector CT.

Three-dimensional C-arm cone-beam CT: applications in the interventional suite

C-arm cone-beam computed tomography (CT) with a flat-panel detector represents the next generation of imaging technology available in the interventional radiology suite and is predicted to be the platform for many of the three-dimensional (3D) roadmapping and navigational tools that will emerge in parallel with its integration. The combination of current and unappreciated capabilities may be the foundation on which improvements in both safety and effectiveness of complex vascular and nonvascular interventional procedures become possible. These improvements include multiplanar soft tissue imaging, enhanced pretreatment target lesion roadmapping and guidance, and the ability for immediate multiplanar posttreatment assessment. These key features alone may translate to a reduction in the use of iodinated contrast media, a decrease in the radiation dose to the patient and operator, and an increase in the therapeutic index (increase in the safety-vs-benefit ratio). In routine practice, imaging information obtained with C-arm cone-beam CT provides a subjective level of confidence factor to the operator that has not yet been thoroughly quantified.

Impact of C-arm CT on hepatic arterial interventions for hepatic malignancies

PURPOSE

To evaluate C-arm computed tomography (CT) and assess its potential impact on hepatic arterial interventions.

MATERIALS AND METHODS

Between May 2005 and March 2006, all hepatic arterial interventions for hepatic malignancies were retrospectively reviewed. C-arm CT acquisitions were performed as an adjunct to conventional digital subtraction angiography (DSA). The number of procedures with C-arm CT, the acquisitions per intervention, and the procedure time for all interventions were recorded. The added information provided by C-arm CT was scored as category 1 (no additional information); category 2 (added information without impact on procedure management); or category 3 (added information with impact on procedure management). Intervention types included infusions, radioembolization, embolization, and chemoembolization. A two-sided, two-sample t test was used to compare interventions with and without C-arm CT, and P values less than .05 were considered significant.

RESULTS

C-arm CT was used in 86 of 240 interventions (36%) in 135 patients. The mean number of acquisitions per study was 1.9 (range, 1-4). Thirty-five interventions (40.7%) were scored as category 2 and 16 interventions (18.6%) were scored as category 3. Chemoembolization was associated with the highest percentage of C-arm CT investigations classified as category 2 and 3 assessed per intervention. The mean procedure time was significantly longer (18 minutes) when C-arm CT was used (P<.001).

CONCLUSIONS

C-arm CT provides additional imaging information beyond DSA during hepatic arterial interventions (approximately 60%), and this information impacted procedure management in 19% of cases. C-arm CT offers the greatest opportunity for additional information during chemoembolization procedures and is responsible for a significant but acceptable increase in procedure time for this type of hepatic intervention.

Aortoesophageal fistula after thoracic endovascular aortic repair and transthoracic embolization

Endografts are more commonly being used to treat thoracic aortic aneurysms and other vascular lesions. Endoleaks are a potential complication of this treatment modality and can be associated with aneurysmal sac expansion and rupture. This case report presents a patient who developed a type IA endoleak after endograft repair of a descending thoracic aneurysm. The endoleak was successfully treated through computed tomographic-guided transthoracic embolization, although the patient experienced lower extremity paraparesis postprocedurally. The patient's endovascular repair was complicated by the development of an aortoesophageal fistula and endograft infection necessitating operative débridement and endograft explantation.