RPS 1409b - Peripheral arterial interventions

Purpose:

In previous clinical studies, digital variance angiography (DVA) provided higher SNR and better image quality than digital subtraction angiography (DSA). The observed quality reserve might provide an opportunity for the reduction of radiation exposure in x-ray angiography. Our aim was to evaluate the potential of DVA to reduce x-ray dose in lower limb angiography.

Methods and materials:

In this prospective clinical study (OGYÉI2830/2017), we enrolled 30 patients with normal renal function undergoing elective lower limb angiography. We compared the signal-to-noise ratio (SNR) of DSA and DVA image-pairs in three regions (abdominal, femoral, and crural) obtained by the Siemens Extremities Care preset (E, 1.2 Gy/frame) or by a low-dose protocol (R, 0.36 microGy/frame). Visual evaluation of all images was performed by specialists using a 5-grade rating scale. The quality of DSA-E and DVA-R images was also compared.

Results:

The SNR of DVA images were consistently higher (2.7-3.1-fold) than the corresponding DSA images. Even DVA-R had better SNR than DSA-E (2.1-fold). Altogether, 256 image-pairs were evaluated. DVA images had a significantly higher Likert-score than the corresponding DSA images (E: 3.90±0.07 vs 3.56±0.08, p<0.05; R: 3.60±0.08 vs 3.29±0.09, p<0.05) but there was no difference between DSA-E and DVA-R (3.56±0.08 vs 3.60±0.08). In 77% of all comparisons, DVA-R had at least as good quality as DSA-E with the following regional differences: abdominal 62%, femoral 74%, and crural 84%.

Conclusion:

Our data shows that DVA allows for a very substantial (70%) x-ray dose reduction in lower limb angiography without affecting the quality and diagnostic value of angiograms.

Limitations:

A single-centre trial.

Ethics committee approval

National Institute of Pharrmacy and Nutrition, license number: OGYÉI2830/2017.

Funding:

No funding was received for this work.

Purpose:

Acute thromboembolic occlusion of the superior mesenteric artery (AMS) is a condition with an unfavourable prognosis. Early diagnosis and timely treatment, either surgical or endovascular, is fundamental to restoring blood flow to the ischaemic intestine and to reduce the possible necrotic bowel tracts. The aim of our work is to describe the management of acute AMS thromboembolic occlusion through endovascular thrombus aspiration.

Methods and materials:

We reviewed the charts of 41 patients from 2017-2019 with MD-CT diagnosis of acute AMS thromboembolic occlusion and initial signs of bowel ischemia. 35/41 patients underwent endovascular thrombus aspiration through femoral access, with co-axial technique for the treatment of the AMS trunk and its collateral. In the remaining 6 patients, the same technique was performed with subsequent transcatheter selective thrombolytic therapy (12 hours) for the treatment of small distal branches residual thrombi. A follow-up with MD-CT was performed 15 days after the endovascular procedure.

Results:

Technical success was achieved in 39/41 patients (95%) and clinical success in 37/41 (90%). 35/41 patients (85%) had postprocedural patency of the main trunk of the SMA and its distal branches with no bowel resection. 4/41 patients (10%) underwent partial resection of the necrotic intestine. 2/41 patients (5%) died after massive bowel ischemia.

Conclusion:

Acute thromboembolic occlusion of SMA is a potentially fatal vascular emergency which requires early diagnosis and rapid restoration of mesenteric blood flow. Percutaneous endovascular revascularisation techniques are a valuable alternative to surgical thrombectomy as a first-line therapy.

Limitations:

The potential sources of bias.

Ethics committee approval

n/a

Funding:

No funding was received for this work.

Purpose:

To assess the efficacy of different embolic endovascular materials used to control acute arterial bleeding caused by traumatic or iatrogenic conditions.

Methods and materials:

We retrospectively evaluated 83 patients (age range 14-81 years) who underwent embolisation procedures in emergency conditions to control acute abdominal bleedings. Technical success, recurrency rate, and complications were assessed in relation to the pattern of arterial bleeding and to the different embolisation techniques and materials (coils, glue, gel foam, covered stents, and plugs).

Results:

The majority of cases were traumatic and iatrogenic bleeding, respectively, 30 and 42 patients (p<0.001). The most frequent bleeding patterns were blush in 75% of cases (single or multiple), pseudoaneurysms (15%), pseudoaneurysms with fistulisation (5%), and oozing bleeding (5%). Technical success was 99% for all the procedures. Treatment failures occurred in complex arterial bleeding patterns (pseudoaneurysms and pseudoaneurysms with fistulisation). In 1% of cases, a subsequent embolisation was necessary. In general, the complication rate was less than 1%.

Conclusion:

Arterial bleeding is potentially life-threatening and can be treated with interventional angiographic techniques. Technical success, low recurrency rate, and a low percentage of complications are related to appropriate procedural planning. Our study demonstrates the efficacy of many embolic endovascular materials in controlling different patterns of bleeding. A multidisciplinary approach is essential, as well as the integration and review of laboratory data and other imaging studies.

Limitations:

A small sample size.

Ethics committee approval

n/a

Funding:

No funding was received for this work.

Purpose:

To characterise a graft thrombus using quantitative texture analysis on CT angiography in relation to the thrombus age and clinical profile of a patient and its implication on catheter-directed thrombolysis

Methods and materials:

This retrospective study included 67 patients with thrombotic grafts occlusion of the lower extremities referred for catheter-directed thrombolysis. Selected images from pre-procedure CT angiograms were retrieved in a defined study interval, de-identified and assigning each a unique identifier. The clinical data was collected and thrombolysis angiograms from PACS were reviewed for dose of tPA, complications, and the final result.

Thrombi on pre-procedure CTAs were manually segmented and saved as regions-of-interest for subsequent texture analysis. Various textural features were extracted for each ROI. The relationship between each textural feature and (a) the clinical age of the thrombus, (b) the dose of tPA administered, and (c) thrombolysis response (as TIMI grade flow) was explored using Spearman’s rho correlation coefficients.

Results:

The clinical age of the thrombus was positively correlated with grey-level skewness [p=0.0085], angular second moment [p=0.0031], and negatively correlated with sum entropy, entropy, and both run-level and grey-level non-uniformity.

tPA doses adjusted for the length of the graft segment thrombosed have a positive correlation with the mean grey-level, entropy, difference entropy, as well as both run-level and grey-level non-uniformity. It has a negative correlation with the angular second moment, suggesting decreased grey-level homogeneity associated with larger doses of tPA required.

Textural features were not significantly related to post thrombolysis flow across the re-canalised segment calculated as TIMI grade flow.

Conclusion:

CT texture analysis features can be used to predict the age of the graft thrombi as well as the tPA dose required per cm length of the thrombosed graft.

Limitations:

A single-centre study.

Ethics committee approval

Ethics committee approval obtained.

Funding:

No funding was received for this work.

Purpose:

To describe our experience in treating no-option critical limb ischaemia patients employing endovascular techniques for distal deep venous arterialisation.

Methods and materials:

We retrospectively reviewed 16 patients between 2016-2018 (11 M, 5F; mean age 65 years) not eligible for surgical or endovascular approaches for revascularisation and major amputation candidates. After several failed attempts of standard or alternative intraluminal arterial recanalisation, we tried a subintimal approach using a 0.014 inch and 300 cm-long guidewire supported by a 2×40 mm low-profile balloon catheter. Taking advantage of the presence of heavy calcification in the distal portion of the foot artery, we intentionally pursued entry into a distal vein from a subintimal channel through the artery. In case of failure, we attempted the creation of an iatrogenic fistula with a pioneer plus catheter after we placed covered stents to ensure its patency.

Results:

In 10 patients, we were able to revascularise the foot with the first technique, in 6 patients we performed the second one. In one case, it was necessary to embolise a collateral vein which was stealing arterial blood from the angiosomic target. Major amputation was observed in one patient. In two cases, we had minor amputations. In 11 cases, we achieved successful wound healing during 6 month follow-up after the procedures. In 81% of patients (13/16), we observed 3-month-fistula patency. One patient died due to other cardiovascular reasons.

Conclusion:

Distal deep venous arterialisation proved to be an effective, safe, and promising technique to improve recanalisation rates and limb salvage in no-options critical limb ischaemia patients. However, we need further trials and investigations to improve the rate of success and employ it safely in daily clinical practice.

Limitations:

A small sample.

Ethics committee approval

n/a

Funding:

No funding was received for this work.

Purpose:

To evaluate the role of IR in the diagnosis and management of PPH.

Methods and materials:

From 01/2015-05/2019, 656 patients underwent PD. PPH has been classified on the basis of bleeding onset (early if within 24 hours after surgery; delayed when occurring later) and severity (mild or severe according to the amount of blood loss and transfusion requirements) into three grades according to 2007 ISGPS classification.

The source of bleeding, bleeding pattern, type of material used for embolisation, and technical success have been systematically recorded for each PPH.

Results:

58 (8.8%) patients had at least one PPH episode, for a total of 70 PPH (6 early grade b, 14 late grade b, and 50 grade c). Early PPH patients underwent upfront surgery, whereas late PPH episodes were first evaluated with CT scan. Late grade b were then treated conservatively and late grade c all underwent IR procedures.

In this subset, diagnostic angiography revealed the bleeding source in 47/50 (94%) cases (gastroduodenal [15/50, 30%], hepatic [14/50, 28%], superior mesenteric [14/50, 28%], inferior epigastric [2/50, 4%], and dorsal pancreatic artery [2/50, 4%]).

We observed active bleeding in 28 cases (56%), pseudoaneurysms in 21 (42%), and irregular vessels in 16 (32%).

IR permitted an efficient treatment of PPH in 46/47 cases with positive diagnostic angiography (technical success: 97.8%) using, sometimes in combination, covered stent (22/46, 47.8%), coil (21/46, 45.6%), and embolising particles or cyanoacrylic glue (13/46, 28.3%).

Conclusion:

IR has a fundamental role in the diagnosis and treatment of PPH, in particular of grade c PPH.

Limitations:

The need for prospective validation.

Ethics committee approval

Patients’ consent was collected according to the ethics committee requirements in all those who had previously signed a procedure-specific informed consent covering retrospective studies.

Funding:

No funding was received for this work.