Delayed Intimal Blowout after Endovascular Repair of Aortic Dissection

The authors have seen four cases of asymptomatic delayed intimal injury adjacent to a stent graft diagnosed 7 to 16 months after thoracic endovascular aortic repair. Endovascular repeat intervention was successfully performed in three of the four cases as described in the present report. A second consecutive “intimal blowout” in one patient remains under close radiologic surveillance. Possible causes for the intimal blowouts, including stent-graft size, landing zone anatomy, and intrinsically weak aortic tissue, are discussed.     

Morphologic Outcome after Endovascular Treatment of Complicated Type B Aortic Dissection

PurposeTo investigate the long-term morphologic changes of the aorta after thoracic endovascular aortic repair (TEVAR) for acute complicated type B aortic dissection and to analyze whether these changes differed between DeBakey class IIIa and IIIb dissections.Materials and MethodsDuring the period 1999–2009, 58 patients with acute complicated type B aortic dissection were treated with TEVAR. Seven patients lacked follow-up data, leaving 51 patients—17 patients with DeBakey IIIa aortic dissection and 34 patients with DeBakey IIIa aortic dissection IIIb—for inclusion in the study. Computed tomography scans performed before and after TEVAR were evaluated. Maximum thoracic and abdominal aortic diameters and diameters of the true lumen and false lumen at the level of the maximum aortic diameter in the thorax and abdomen were analyzed as well as degree of thrombosis of the false lumen.ResultsThere was an overall significant reduction of the thoracic aortic diameter, increased true lumen diameter, and reduced false lumen diameter (P < .05). Total thrombosis of the false lumen, with or without reintervention, was seen in 53% of all patients, in 41% primarily and in 12% after reintervention. The IIIa group had a higher degree of total false lumen thrombosis. All patients in the IIIb group had total thrombosis of the false lumen along the stent graft.ConclusionsLong-term follow-up showed favorable aortic remodeling after TEVAR for acute complicated type B aortic dissection. Total thrombosis of the false lumen occurred more often in patients with DeBakey IIIa aortic dissection compared with patients with DeBakey IIIb aortic dissection.     

Outcomes of Endovascular Management for Complicated Chronic Type B Aortic Dissection: Effect of the Extent of Stent Graft Coverage and Anatomic Properties of Aortic Dissection

PurposeTo assess the effect of the extent of stent graft coverage and anatomic properties of aortic dissection on the outcomes of thoracic endovascular aortic repair (TEVAR) for complicated chronic type B aortic dissection (CCBAD) in terms of survival, reintervention, and false lumen thrombosis.Materials and MethodsA retrospective analysis was performed of 71 patients who underwent TEVAR for CCBAD. Mean patient age was 54.7 years. Distal extent of stent graft coverage was categorized as short (≤ T7) or long (≥ T8) coverage. Indications of reintervention were categorized into three groups: proximal, alongside, and distal according to the anatomic relationship of the culprit lesion and the stent graft. Overall survival, reintervention-free survival, and extent of false lumen thrombosis were compared.ResultsThe technical success rate was 97.2%. The 1-year, 3-year, and 5-year overall survival rates were 97.1%, 88.9%, and 88.9%, and 1-year, 3-year, and 5-year reintervention-free survival rates were 80.7%, 73.8%, and 60.6%. There were no differences in overall survival, reintervention-free survival rates, and extent of false lumen thrombosis between the groups. In the short coverage group, distal reintervention was more frequent in patients with an abdominal aortic diameter ≥ 37 mm compared with patients with an abdominal aortic diameter < 37 mm (P = .005).ConclusionsTEVAR was effective for CCBAD with a high technical success rate and low mortality. The extent of stent graft coverage did not make a difference in terms of survival and false lumen thrombosis. Reinterventions were more frequently performed in patients with a large baseline abdominal aortic diameter who were treated with short stent graft coverage, and so longer coverage is recommended in such patients.     

Endovascular Abdominal Aortic Aneurysm Repair Using Transvenous Intravascular US Catheter Guidance in Patients with Chronic Renal Failure

PurposeTo describe the transvenous application of intracardiac echocardiography (ICE) for guidance during endovascular aortic repair (EVAR).Materials and MethodsEight patients with an infrarenal abdominal aortic aneurysm (AAA) and chronic renal failure were determined suitable for EVAR. The procedure was performed by deploying the transcaval and transiliac vein guidance of an ICE catheter to reduce the dosage of iodinated contrast medium. Multiple guidance parameters were assessed. The present study describes the EVAR procedure and postprocedure transabdominal ultrasound (US) follow-up results at 3–4 months.ResultsThe eight procedures were completed by using transvenous ICE guidance. No contrast medium was used in five patients, and 3–20 mL of isoosmolar contrast medium was administered in the other three. No endoleaks were detected by ICE immediately after stent deployment. One patient who had a single functioning kidney developed renal failure that was attributed to manipulation-related cholesterol embolization. That patient became dependent on dialysis and died 3.5 months after the procedure. No endoleaks were detected at 3–4-month US follow-up in the other seven patients.ConclusionsTransvenous ICE guidance is a promising method to reduce the dosage of iodinated contrast medium in patients with renal dysfunction undergoing EVAR. A prospective trial comparing this modality versus digital subtraction angiography guidance with iodinated contrast medium in terms of safety, accuracy, and long-term efficacy is recommended.     

Double Coaxial Microcatheter Technique for Transarterial Aneurysm Sac Embolization of Type II Endoleaks after Endovascular Abdominal Aortic Repair

PurposeTo evaluate the feasibility and efficacy of transarterial sac embolization with a mixture of N-butyl cyanoacrylate and ethiodized oil (Lipiodol; Guerbet Japan, Tokyo, Japan) (NBCA-LPD) for type II endoleaks after endovascular aortic repair (EVAR) using a double coaxial microcatheter technique.Materials and MethodsA retrospective review was performed of 20 consecutive cases of type II endoleaks treated by transarterial embolization using the technique from August 2010 to June 2013. The treatment indication was persistent type II endoleak over 6 months after EVAR associated with aneurysm expansion ≥ 5 mm in maximum diameter. A 1.9-F nontapered microcatheter was advanced to the aneurysmal sac through a 2.7-F microcatheter, which was coaxially introduced through a catheter. The endpoint of the procedure was intrasaccular filling with NBCA-LPD and occlusion of the feeder of the type II endoleak. The technical success rate was defined as success in transarterial intrasaccular approach followed by embolization of the intrasaccular channel and inflow arteries. Clinical success was defined as aneurysmal sac shrinkage or stabilization (freedom from sac expansion > 5 mm in maximum diameter).ResultsTechnical success was achieved in 18 of 20 cases. During a mean follow-up period of 18.5 months, complete sac occlusion was observed in 13 cases (65%). Clinical success was achieved in 16 cases (80%). No serious complications were observed.ConclusionsThe transarterial intrasaccular approach with a double coaxial microcatheter technique can be successfully performed in most cases, and transarterial aneurysm sac embolization using NBCA-LPD has been proven to be feasible.     

Image Guidance for Endovascular Repair of Complex Aortic Aneurysms: Comparison of Two-dimensional and Three-dimensional Angiography and Image Fusion

PurposeTo evaluate the feasibility of image fusion (IF) of preprocedural arterial-phase computed tomography with intraprocedural fluoroscopy for roadmapping in endovascular repair of complex aortic aneurysms, and to compare this approach versus current roadmapping methods (ie, two-dimensional [2D] and three-dimensional [3D] angiography).Materials and MethodsThirty-seven consecutive patients with complex aortic aneurysms treated with endovascular techniques were retrospectively reviewed; these included aneurysms of digestive and/or renal arteries and pararenal and juxtarenal aortic aneurysms. All interventions were performed with the same angiographic system. According to the availability of different roadmapping software, patients were successively placed into three intraprocedural image guidance groups: (i) 2D angiography (n = 9), (ii) 3D rotational angiography (n = 14), and (iii) IF (n = 14). X-ray exposure (dose–area product [DAP]), injected contrast medium volume, and procedure time were recorded.ResultsPatient characteristics were similar among groups, with no statistically significant differences (P ≥ .05). There was no statistical difference in endograft deployment success between groups (2D angiography, eight of nine patients [89%]; 3D angiography and IF, 14 of 14 patients each [100%]). The IF group showed significant reduction (P < .0001) in injected contrast medium volume versus other groups (2D, 235 mL ± 145; 3D, 225 mL ± 119; IF, 65 mL ± 28). Mean DAP values showed no significant difference between groups (2D, 1,188 Gy·cm² ± 1,067; 3D, 984 Gy·cm² ± 581; IF, 655 Gy·cm² ± 457; P = .18); nor did procedure times (2D, 233 min ± 123; 3D, 181 min ± 53; IF, 189 min ± 60; P = .59).ConclusionsThe use of IF-based roadmapping is a feasible technique for endovascular complex aneurysm repair associated with significant reduction of injected contrast agent volume and similar x-ray exposure and procedure time.     

Management of Type II Endoleak after Endovascular Repair of Arteriocaval Fistula Complicating Aortoiliac Aneurysm: Case Report and Literature Review

Endovascular treatment for arteriocaval fistula (ACF) has become the preferred alternative to open repair. However, endoleaks sometimes occur and maintain the ACF. A 64-year-old man presented with persistent fistula after placement of a bifurcated stent-graft for ACF complicating an aortoiliac aneurysm that was maintained by endoleaks from the inferior mesenteric and lumbar arteries. Transarterial embolization of the aneurysm sac and inferior mesenteric artery successfully resolved the problem without any complications observed over 16 months of follow-up. A literature review and discussion of the management options for this entity are presented. A combination of inflow and outflow control is important to obtain better long-term outcomes.     

A Decade of Outcomes and Predictors of Sac Enlargement after Endovascular Abdominal Aortic Aneurysm Repair Using Zenith Endografts in a Japanese Population

PurposeTo present 10-year outcomes and risk factors for sac enlargement after endovascular aneurysm repair (EVAR) using the Zenith AAA Endovascular Graft (Cook, Inc, Bloomington, Indiana) in a Japanese population.Material and MethodsDuring the period 1999–2011, 127 patients underwent elective EVAR using Zenith endografts at a single institution. A retrospective investigation looked at initial rates of technical success and complications, 10-year rate of freedom from all-cause and aneurysm-related mortality, freedom from secondary intervention and sac enlargement, and risk factors for second intervention and sac enlargement.ResultsThe median age of the patients was 78 years, and the median follow-up time was 43 months. The initial technical success rate was 98.4% (125 of 127 patients). Major adverse events occurred in 7 of 127 (5.5%) patients. Rates of freedom from all-cause and aneurysm-related mortality at 1, 3, 5, and 10 years were 95%, 87%, 77%, and 39% (all-cause mortality) and 100%, 100%, 99%, and 93% (aneurysm-related mortality). Rates of freedom from secondary intervention at 1, 3, 5, and 10 years were 97%, 91%, 88%, and 70%. Rates of primary freedom from sac enlargement at 1, 3, 5, and 10 years were 99%, 87%, 75%, and 67%. Multivariate analysis revealed aneurysm sac diameter as an independent risk factor for a secondary intervention. Preoperative sac diameter combined with an angulated short (AS) proximal neck was a risk factor for sac enlargement.ConclusionsThe 10-year results of EVAR using Zenith endografts in a Japanese population were comparable to results from Western countries. Larger aneurysms and AS neck were predictors of sac enlargement after EVAR.     

Irreversible Electroporation Ablation of Malignant Hepatic Tumors: Subacute and Follow-up CT Appearance of Ablation Zones

PurposeTo describe findings on contrast-enhanced computed tomography (CT) images of malignant hepatic tumors 24–72 hours after percutaneous ablation by irreversible electroporation (IRE) and at midterm follow-up.Materials and MethodsRetrospective analysis of 52 malignant liver tumors—30 primary hepatic tumors and 22 hepatic metastases—in 34 patients (28 men and 6 women, mean age 64 y) treated by IRE ablation was performed. Ablation zones were evaluated by two examiners in a consensus reading by means of a dual-phase CT scan (consisting of a hepatic arterial and portal venous phase) performed 24–72 hours after IRE ablation and at follow-up.ResultsDuring the portal venous phase, ablation zones either were homogeneously hypoattenuating (n = 36) or contained heterogeneously isoattenuating or hyperattenuating (n = 16) foci, or both, in a hypoattenuating area. Of 52 lesions, 38 included gas pockets. Peripheral contrast enhancement of the ablation defect was evident in 23 tumors during the arterial phase and in 36 tumors during the portal venous phase. Four tumors showed intralesional abscesses after the intervention. At follow-up (mean, 4.7 mo), the mean volume of the ablation defects was reduced to 29% of their initial value.ConclusionsBecause normal findings on contrast-enhanced CT images after IRE ablation may be very similar to the typical characteristics of potential complications following ablation, such as liver abscesses, CT scans must be carefully analyzed to distinguish normal results after intervention from complications requiring further treatment.     

Surgical or Endovascular Therapy of Abdominal Penetrating Aortic Ulcers and Their Natural History: A Systematic Review

Little is known regarding the outcomes of endovascular and surgical treatment of penetrating ulcers in the abdominal aorta. The potential benefit of conservative management of asymptomatic disease is also debatable. A systematic review of the literature was undertaken to investigate these issues.     

Impact on Pulmonary Arterial Pressures after Repeated Endovascular Thrombectomy of Dialysis Grafts: A Prospective Follow-up Study

PurposeVascular access thrombosis is a common complication of arteriovenous dialysis grafts that results in silent pulmonary embolism (PE) in a substantial proportion of patients. However, the impact of repeated PE on the pulmonary vasculature remains unclear.Materials and MethodsFrom January 2010 to April 2012, 110 patients undergoing maintenance hemodialysis via arteriovenous grafts were recruited. Hemodynamic assessments, including transthoracic echocardiography and right heart catheterization, were performed at baseline and after 1 year to evaluate the changes in pulmonary artery (PA) pressures and heart function.ResultsFifty-two patients completed the follow-up hemodynamic assessment at a median duration of 535 days and had at least one endovascular thrombectomy procedure (median of seven). There was no significant difference in mean PA pressures between baseline and the end of follow-up (23.1 mm Hg ± 6.8 vs 21.6 mm Hg ± 6.1; P = .16). The change in mean PA pressure did not correlate with the number of thrombectomy procedures in the overall cohort (r = −0.02, P = .89) or in the subgroup with cardiopulmonary disease (r = −0.30, P = .14). The changes of mean PA pressure were not associated with number of thrombectomy procedures (β = −0.03, P = .89).ConclusionsRepeated endovascular thrombectomy procedures are not related to changes in PA pressure in the short term. The present results support the safety of endovascular thrombectomy in the pulmonary vasculature.     

Hepatic Blood Volume Imaging with the Use of Flat-Detector CT Perfusion in the Angiography Suite: Comparison with Results of Conventional Multislice CT Perfusion

PurposeTo prospectively determine the feasibility of flat-detector (FD) computed tomography (CT) perfusion to measure hepatic blood volume (BV) in the angiography suite in patients with hepatocellular carcinoma (HCC).Materials and MethodsTwenty patients with HCC were investigated with conventional multislice and FD CT perfusion. CT perfusion was carried out on a multislice CT scanner, and FD CT perfusion was performed on a C-arm angiographic system, before transarterial chemoembolization procedures. BV values of conventional and FD CT perfusion were measured within tumors and liver parenchyma. The arterial perfusion portion of CT perfusion BV was extracted from CT perfusion BV by multiplying it by a hepatic perfusion index. Relative values (RVs) for CT perfusion arterial BV and FD CT perfusion BV (FD BV) were defined by dividing BV of tumor by BV of parenchyma. Relationships between BV and RV values of these two techniques were analyzed.ResultsIn all patients, both perfusion procedures were technically successful, and all 33 HCCs larger than 10 mm were identified with both imaging methods. There were strong correlations between the absolute values of FD BV and CT perfusion arterial BV (tumor, r = 0.903; parenchyma, r = 0.920; both P < .001). Bland–Altman analysis showed a mean difference of −0.15 ± 0.24 between RVs for CT perfusion arterial BV and FD BV.ConclusionsThe feasibility of FD CT perfusion to assess BV values of liver tumor and surrounding parenchyma in the angiographic suite was demonstrated.     

Aortic Arch Vessel Geometries and Deformations in Patients with Thoracic Aortic Aneurysms and Dissections

PurposeTo quantify aortic arch geometry and in vivo cardiac-induced and respiratory-induced arch translations and arch branch angulations using three-dimensional geometric modeling techniques.Materials and MethodsScanning with electrocardiogram-gated computed tomography angiography during inspiratory and expiratory breath holds was performed in 15 patients (age, 64 y ± 14) with thoracic aortic aneurysms or dissections. From the lumen models, centerlines of the thoracic aorta, brachiocephalic artery, left common carotid artery, and left subclavian artery and their branching ostia positions were quantified. Three-dimensional translation of vessel ostia, branching angles, and their changes secondary to cardiac pulsation and respiration were computed.ResultsDuring expiration, all ostia translated rightward from systole to diastole (P < .035). Regardless of cardiac phase, all ostia translated posteriorly and superiorly from inspiration to expiration (P < .05). Respiration induced greater posterior and superior translations than cardiac pulsation (P < .03). The left common carotid artery branch angled significantly more toward the aortic arch compared with the brachiocephalic artery and left subclavian artery (P < .03). No significant changes in branching angle were found from systole to diastole or inspiration to expiration.ConclusionsIn patients with thoracic aortic aneurysms or dissections, the thoracic aortic arch translated significantly secondary to inspiration and expiration and to a lesser extent secondary to cardiac pulsation. Insignificant branching angle changes suggest that the aortic arch and its branch origins move predominantly in unison.     

Closure of the Axillary Artery Puncture Site with StarClose System after Endovascular Interventions

The use of the StarClose vascular closure device for puncture site hemostasis after therapeutic endovascular interventions performed through the axillary artery under anticoagulant therapy in six patients is reported. Three minor complications, including hematoma, prolonged hemostasis, and pain, occurred in three patients. Based on this limited experience, this method can be used safely for axillary artery puncture site hemostasis after endovascular procedures without significant complications.     

Clinical Features and Endovascular Management of Iliac Artery Fibromuscular Dysplasia

PurposeTo identify the spectrum of clinical presentation of iliac artery fibromuscular dysplasia (FMD) and to evaluate the outcomes of endovascular management of iliac artery FMD for claudication.Materials and MethodsAll patients in a single institution with a diagnosis of FMD between January 1980 and December 2010 were identified. Iliac artery FMD was present in 14 patients. Associated risk factors included hypertension (79%), hyperlipidemia (64%), smoking history (36%), coronary artery disease (21%), diabetes (0%), and obesity (36%).ResultsIn eight (57%) patients, iliac artery FMD was incidentally found on imaging. Lifestyle-limiting claudication involving one or both extremities was present in six (43%) patients. All six patients were reported to have mild peripheral arterial disease based on ankle-brachial index measurements (0.7–0.9). These six patients underwent 10 endovascular procedures for claudication, including angioplasty (n = 8) and self-expanding stent placement (n = 2). Mean symptom-free survival was 56.3 months.ConclusionsIliac artery FMD that is amenable to endovascular treatment may be found incidentally or may manifest with disabling claudication.     

Successful Endovascular Treatment of Iliac Arteriovesical Fistula with Secondary Stent-Graft Infection

A 58-year-old woman initially presented with massive gross hematuria and iliac arteriovesical fistula (IAVF). Endovascular stent-graft repair achieved complete exclusion of the IAVF and controlled the bleeding, but sepsis subsequently developed because of endograft infection. Endovascular embolization of the infected stent graft was performed after extraanatomic bypass surgery. The patient recovered and showed no signs of graft infection or recurrent fistulization at 14 months after treatment. Endovascular embolization of infected stent grafts combined with extraanatomic bypass may be an acceptable treatment option for graft-related sepsis in cases that are resistant to conservative treatment and pose high surgical risk for graft excision.     

Endovascular Recanalization of Native Chronic Total Occlusions in Patients with Failed Lower-Extremity Bypass Grafts

PurposeTo investigate the feasibility, safety, and outcome of endovascular recanalization of native chronic total occlusions (CTOs) in patients with failed lower-extremity bypass grafts.Materials and MethodsRetrospective review of 19 limbs in 18 patients with failed lower-extremity bypass grafts that underwent recanalization of native arterial occlusions between February 2009 and April 2013 was performed. Nine of the limbs presented with acute ischemia and 10 presented with chronic ischemia, including eight with critical limb ischemia and two with disabling claudication.ResultsThe mean patency of the failed bypass grafts (63% venous) was 27 months. All limbs had Transatlantic Inter-Society Consensus class D lesions involving the native circulation. Technical success of the endovascular recanalization procedure was achieved in all but one limb (95%). The mean ankle brachial indices before and after treatment were 0.34 and 0.73, respectively. There were no major complications or emergency amputations. Mean patient follow-up was 64 weeks, and two patients were lost to follow-up. Primary patency rates at 3, 6, and 12 months were 87%, 48%, and 16%, respectively. Successful secondary procedures were performed in seven patients, with secondary patency rates at 3, 6, and 12 months of 88%, 73%, and 44%, respectively. Limb salvage rates at 12 and 24 months were 94% and 65%, and amputation-free survival rates at 12 and 24 months were 87% and 60%, respectively.ConclusionsEndovascular recanalization of native CTOs in patients with failed lower-extremity bypass grafts is technically feasible and safe and results in acceptable limb salvage.     

Dynamic Volumetric CT Angiography for the Detection and Classification of Endoleaks: Application of Cine Imaging Using a 320-Row CT Scanner with 16-cm Detectors

PurposeTo assess the feasibility and diagnostic performance of dynamic volumetric computed tomography (CT) angiography with large-area detectors in the detection and classification of endoleaks after endovascular aneurysm repair (EVAR).Materials and MethodsLow-dose dynamic volumetric CT angiography performed with the patient in Fowler position was used to scan the entire stent graft with a 16-cm-area detector during the first follow-up examination after EVAR. There were 39 consecutive patients (36 men and 3 women; mean age, 74 y ± 8.7) examined with approximately 14–20 intermittent scans (temporal resolution, 2 s; scan range, 160 mm). The effective radiation dose, image quality, interobserver and intraobserver agreement for endoleak detection, and time delay between peak enhancement of the aorta and endoleaks were evaluated.ResultsAll examinations with the patient in Fowler position enabled the entire stent graft to be scanned and were rated as diagnostic. The mean effective radiation dose was 13.1 mSv. Endoleaks were detected in eight patients (type Ia, n = 1; type II, n = 6; type III, n = 1). Interobserver agreement (κ = 0.794) and intraobserver agreement (κ = 1.00) for detection of endoleaks were excellent. The mean time delay between peak enhancement of the aorta and the endoleaks was significantly less for type I/III endoleaks (2.0 s ± 0) compared with type II endoleaks (5.3 s ± 1.0; P < .001).ConclusionsLow-dose dynamic volumetric CT angiography performed with the patient in Fowler position is feasible after EVAR. Dynamic information, including cine imaging, the timing of peak enhancement, and the Hounsfield units index, is useful in detecting and classifying endoleaks.     

Endovascular Venous Thrombolysis in Children Younger than 24 Months

PurposeTo evaluate the technical feasibility and safety of percutaneous endovascular thrombolysis for extremity deep venous thrombosis (DVT) in children < 24 months old.Materials and MethodsA retrospective chart review of a clinical and imaging database was performed for pediatric patients who underwent endovascular therapy for DVT between January 2010 and July 2013. Indications, techniques, technical and clinical success, and complications were reviewed. Techniques for thrombolysis included catheter-directed therapy (CDT) using alteplase infusion via a multi–side hole catheter, mechanical thrombectomy, and angioplasty. Short-term outcomes were assessed using surgical and imaging follow-up examinations for patency of the targeted vessel. Patients included 11 children (mean age, 9 mo; range, 3 wk–23 mo) who consecutively underwent endovascular thrombolysis for upper extremity (n = 6) or lower extremity (n = 5) DVT. The most common indication was preservation of venous access for future cardiac surgery or medical therapy.ResultsThe most common risk factor was the presence of a central venous catheter (10 of 11 patients). All patients with upper extremity DVT had congenital heart disease. CDT and angioplasty were performed in all patients. Venous patency was established in all patients. A grade III (95%–100%) thrombolysis response was achieved in seven patients, and a grade II (50%–95%) thrombolysis response was achieved in four patients. A major complication of pulmonary embolism occurred in one patient with upper extremity thrombolysis and was managed by intravenous systemic alteplase and heparin. No recurrence of thrombosis was found on average follow-up of 11.8 months (range, 1–41 mo).ConclusionsPercutaneous endovascular thrombolysis for extremity DVT is safe and technically feasible in children < 24 months old.     

Irreversible Electroporation of the Pig Kidney with Involvement of the Renal Pelvis: Technical Aspects,Clinical Outcome,and Three-dimensional CT Rendering for Assessment of the Treatment Zone

PurposeTo analyze irreversible electroporation (IRE) of the pig kidney with involvement of the renal pelvis.Materials and MethodsIRE of renal tissue including the pelvis was performed in 10 kidneys in five pigs. Three study groups were defined: group I (two applicators with parallel configuration; n = 11), group II (three applicators with triangular configuration; n = 2), and group III (six applicators with complex configuration; n = 3). After IRE and before euthanasia, pigs underwent contrast-enhanced computed tomography (CT). Technical aspects (radial distance of applicators, resulting mean current), clinical outcome (complications, blood samples), and three-dimensional CT rendering for assessment of the treatment zone (short axis, circularity) were assessed.ResultsRadial distances of applicators were 14.3 mm ± 2.8 in group I, 12.3 mm ± 1.9 in group II, and 16.4 mm ± 3.5 in group III. Resulting mean currents were 25.7 A ± 6.5 in group I, 27.0 A ± 7.1 in group II, and 39.4 A ± 8.9 in group III. In group III, two perirenal hematomas were identified. There was no damage to the renal pelvis. During IRE, clinical blood parameters and cardiovascular markers did not change significantly. Short axis measurements were 20.6 mm ± 3.6 in group I, 31.9 mm ± 8.2 in group II, and 39.3 mm ± 2.4 in group III (P < .01 between groups). Circularity scores were 0.8 ± 0.2 in group I, 0.7 ± 0.1 in group II, and 0.7 ± 0.1 in group III, with a score of 1 indicating perfect roundness (P value not significant).ConclusionsIRE of the pig kidney with involvement of the renal pelvis is feasible and safe. Size but not shape of the treatment zone is significantly affected by applicator configuration.