Efficacy of Sac Coil Embolization in Endovascular Aortic Repair for Sac Shrinkage in Patients at a High Risk of Type II Endoleak from Lumbar Arteries.

BACKGROUND: In endovascular aortic repair (EVAR), preemptive embolization of sac branch vessels is effective in preventing postoperative type II endoleak (T2EL). However, this technique has not been widely adopted especially for lumbar arteries (LAs) because of technical difficulties and time constraints. This study aimed to investigate the efficacy of nonselective sac coil embolization, which is a simpler surgical method, in postoperative sac shrinkage for patients at a high risk of T2EL from LAs. METHODS: We retrospectively assessed 76 patients who underwent elective EVAR for abdominal aortic aneurysm with 4 or more patent LAs or at least 1 patent LA of ≥2 mm at our hospital between January 2014 and December 2022. The patients who underwent sac coil embolization were included in Group Ⅰ (n = 20), and the others were divided into 2 groups: those with an inferior mesenteric artery that was originally occluded or embolized by coils or stent graft bodies (Group Ⅱ, n = 21), and those without that (Group Ⅲ, n = 35). In Group Ⅰ, 0.035-inch coils were inserted into the sac after complete stent graft deployment. The cumulative incidence of sac shrinkage (≥5 mm) was compared between the groups. Further, univariable and multivariable Cox regression analyses were used to determine the predictors of sac shrinkage. RESULTS: Sac shrinkage (≥5 mm) was observed more frequently in Group Ⅰ (50%) than in Group Ⅱ (19%) and Group Ⅲ (17%) (P = 0.052 and 0.043, respectively). The cumulative incidence of sac shrinkage was significantly higher in Group Ⅰ than in Group Ⅱ (log-rank P = 0.039) and Group Ⅲ (log-rank P = 0.024). Multivariable Cox regression analyses revealed that sac embolization was a significant predictor of sac shrinkage (hazard ratio, 4.23; 95% confidence interval, 1.66-10.8; P = 0.003). CONCLUSIONS: Nonselective sac coil embolization in EVAR is potentially effective for sac shrinkage in the early postoperative phase in patients at high risk of T2EL from LAs. This simple procedure may improve prognosis after EVAR.

Open Versus Zone 0/1 Endovascular Aortic Repair for Arch Aneurysm: A Propensity Score-Matched Study from the National Clinical Database in Japan.

BACKGROUND: Although open surgical repair (OSR) is the gold standard for treating arch aneurysms, thoracic endovascular aortic repair (TEVAR) may be a less invasive alternative. However, it remains unclear which of the 2 methods yields better outcomes. In this study, we compared the perioperative outcomes of both procedures for arch aneurysms using a nationwide surgical database. METHODS: Data of patients who underwent elective aortic repair for true arch aneurysms were extracted from the National Clinical Database of Japan. Patients who underwent OSR and Zone 0/1 TEVAR were matched in a 1:1 ratio using propensity scores and their mortality and morbidity rates were compared. RESULTS: A total of 2,815 and 1,125 patients underwent OSR and Zone 0/1 TEVAR, respectively. After propensity score matching, 1,058 patients were included in both groups. Compared with OSR, Zone 0/1 TEVAR was associated with a significantly higher incidence of stroke (5.8 vs. 10.0%, P < 0.001) and paraplegia/paraparesis (1.6 vs. 4.4%, P < 0.001). However, there were no significant differences in the 30-day and operative mortality rates between the 2 groups (2.2 vs. 2.7% and 4.5 vs. 5.4%, respectively). In the Zone 0/1 TEVAR group, postoperative computed tomography was performed in 92.4% of patients, and types I and III endoleaks were identified in 6.4% and 1.1% of patients, respectively. CONCLUSIONS: Zone 0/1 TEVAR has higher incidences of stroke and paraplegia/paraparesis than OSR, with a risk of postoperative endoleaks. Resolving these problems is the key for expanding the application of Zone 0/1 TEVAR and in the meantime OSR remains the gold standard for surgically fit patients.

Necrostatin-1 Attenuates Delayed Paraplegia after Transient Spinal Cord Ischemia in Rabbits by Inhibiting the Upregulation of Receptor-Interacting Protein Kinase 1 and 3.

BACKGROUND: Delayed-onset paraplegia is a disastrous complication after thoracoabdominal aortic open surgery and thoracic endovascular aortic repair. Studies have revealed that transient spinal cord ischemia caused by temporary occlusion of the aorta induces delayed motor neuron death owing to apoptosis and necroptosis. Recently, necrostatin-1 (Nec-1), a necroptosis inhibitor, has been reported to reduce cerebral and myocardial infarction in rats or pigs. In this study, we investigated the efficacy of Nec-1 in delayed paraplegia after transient spinal cord ischemia in rabbits and assessed the expression of necroptosis- and apoptosis-related proteins in motor neurons. METHODS: This study used rabbit transient spinal cord ischemia models using a balloon catheter. They were divided into a vehicle-treated group (n = 24), Nec-1-treated group (n = 24), and sham-controls (n = 6). In the Nec-1-treated group, 1 mg/kg of Nec-1 was intravascularly administered immediately before ischemia induction. Neurological function was assessed using the modified Tarlov score, and the spinal cord was removed 8 hr and 1, 2, and 7 days after reperfusion. Morphological changes were examined using hematoxylin and eosin staining. The expression levels of necroptosis-related proteins (receptor-interacting protein kinase [RIP] 1 and 3) and apoptosis-related proteins (Bax and caspase-8) were assessed using western blotting and histochemical analysis. We also performed double-fluorescence immunohistochemical studies of RIP1, RIP3, Bax, and caspase-8. RESULTS: Neurological function significantly improved in the Nec-1-treated group compared with that in the vehicle-treated group 7 days after reperfusion (median 3 and 0, P = 0.025). Motor neurons observed 7 days after reperfusion were significantly decreased in both groups compared with the sham group (vehicle-treated, P < 0.001; Nec-1-treated, P < 0.001). However, significantly more motor neurons survived in the Nec-1-treated group than in the vehicle-treated group (P < 0.001). Western blot analysis revealed RIP1, RIP3, Bax, and caspase-8 upregulation 8 hr after reperfusion in the vehicle-treated group (RIP1, P = 0.001; RIP3, P = 0.045; Bax, P = 0.042; caspase-8, P = 0.047). In the Nec-1-treated group, the upregulation of RIP1 and RIP3 was not observed at any time point, whereas that of Bax and caspase-8 was observed 8 hr after reperfusion (Bax, P = 0.029; caspase-8, P = 0.021). Immunohistochemical study revealed the immunoreactivity of these proteins in motor neurons. Double-fluorescence immunohistochemistry revealed the induction of RIP1 and RIP3, and that of Bax and caspase-8, in the same motor neurons. CONCLUSIONS: These data suggest that Nec-1 reduces delayed motor neuron death and attenuates delayed paraplegia after transient spinal cord ischemia in rabbits by selectively inhibiting necroptosis of motor neurons with minimal effect on their apoptosis.

Endovascular Aortic Repair for Thoracic Aortic Compression Resulting From Chance Fracture of the Thoracic Spine.

Blunt aortic injury is a serious condition with a high mortality rate. Although rare, blunt aortic injury associated with spinal fracture has also been reported, and appropriate management of aortic disease is key to a good outcome. This report is a case of a 78-year-old man who was found to have a transverse fracture (Chance fracture) in the ninth thoracic vertebra, with a sharp bone fragment compressing the thoracic aorta. Early spinal surgery was needed; however, there was concern about the possibility of bleeding from the aorta and surrounding small arteries associated with the bone fragment during spinal surgery. Therefore, thoracic endovascular aortic repair was performed before spinal surgery. The next day after thoracic endovascular aortic repair, posterior spinal instrumentation was performed, and the postoperative course was uneventful. Because aortic injury associated with vertebral fracture can lead to massive bleeding and spinal cord injury, endovascular repair before spinal surgery is reasonable.

Investigating the cause of hemolysis in patients supported by a pulsatile ventricular assist device.

A survey conducted by Abiomed, Inc. revealed that 10 of 60 patients who received ventricular assistance via the AB5000 ventricular assist device (VAD) experienced hemolysis. The present study was conducted to investigate which factors influence hemolysis under pulsatile-flow VADs such as the AB5000. We compared the specificity of the AB5000 and its driving console with those of the NIPRO-VAD and VCT50χ under severe heart failure conditions using a mock circulatory system with a glycerol water solution. We used the mock circuit with bovine blood to confirm which pump conditions were most likely to cause hemolysis. In addition, we measured the shear velocity using particle image velocimetry by analyzing the seeding particle motion for both the AB5000 and NIPRO-VAD under the same conditions as those indicated in the initial experiment. Finally, we analyzed the correlation between negative pressure, exposure time, and hemolysis by continuously exposing fixed vacuum pressures for fixed times in a sealed device injected with bovine blood. Applying higher vacuum pressure to the AB5000 pump yielded a larger minimum inlet pressure and a longer exposure time when the negative pressure was under - 10 mmHg. The plasma-free hemoglobin increased as more negative pressure was driven into the AB5000 pump. Moreover, the negative pressure interacted with the exposure time, inducing hemolysis. This study revealed that negative pressure and exposure time were both associated with hemolysis.

Successful papillary muscle approximation for severe mitral regurgitation via apical cuff hole in HeartMate 3 implantation via left anterior thoracotomy.

We herein report a case of successful papillary muscle approximation for severe mitral regurgitation and HeartMate 3 left ventricular assist device implantation via left anterior thoracotomy in a 39-year-old man diagnosed with dilated cardiomyopathy. He underwent papillary muscle approximation in the mitral valve for severe functional regurgitation via the apical cuff hole. The postoperative course was uneventful. Echocardiography revealed that mitral regurgitation has disappeared. He was awaiting heart transplantation while working.

Aortic root morphology can cause early bioprosthetic valve failure of externally mounted pericardial bioprosthesis.

A 73-year-old woman with a narrow aortic root had undergone aortic valve replacement with a 19-mm Mitroflow valve. Aortic annular enlargement with Manouguian's technique was performed, and the bioprosthesis had been implanted on the tilt in a supra-annular position. Four years after the implantation, echocardiography showed a significant de novo aortic regurgitation, which had not been detected 1 year earlier. In the reoperation, the left coronary leaflet of the bioprosthesis had attached and fused to the wall of the sinus of Valsalva, causing deformation of the valve leaflet and a commissural gap between the left and right coronary leaflets, which appeared to have caused the de novo aortic regurgitation. We assessed the cause of early valve deterioration by focusing on the morphology of the aortic root. Preoperative understanding of the aortic root morphology would help to avoid early valve dysfunction for aortic valve replacement with an externally mounted bioprosthesis.

Long-term function of Hydrofit as hemostatic sealant: abridged republication.

The newly-designed hemostatic sealant, Hydrofit, was developed in Japan and consists of a urethane-based polymer without blood products. By applying Hydrofit gel to an anastomosis site on the aorta, water contact initiates a chemical change in the forming elastomer which adheres rapidly and tightly. We experienced an extirpation of Hydrofit gel that had been applied 4 years and 8 months previously in a 42-year-old female who underwent aortic valve replacement and graft replacement of the ascending aorta. The Hydrofit left around the aortic graft suture line was without infection and functioned very well as an elastic sealant for a long period.

Efficacy of preoperative electrocardiographic-gated computed tomography in predicting the accurate aortic annulus diameter in surgical aortic valve replacement.

OBJECTIVE: Electrocardiographic (ECG)-gated computed tomography (CT) can be used to determine which valve and size should be used in transcatheter aortic valve replacement (TAVR). It is beneficial to predict the accurate annulus diameter in surgical aortic valve replacement (SAVR), which can help in determining the surgical strategy. We aimed to compare the predicted aortic annulus size with the actual annulus size measured intraoperatively and to examine its validity. METHODS: A total of 88 patients underwent isolated or concomitant SAVR in 2018 at our hospital. The study population consisted of 45 patients who underwent preoperative CT assessment and intraoperative measurement. The perimeter- and area-derived diameters at the level of basal attachments were determined using CT, and the lower value among the two was defined as the predicted aortic annulus (CTpredict). The predicted aortic annulus (TTEpredict) was measured by transthoracic echography in the parasternal long-axis view. An actual-sized ball sizer was inserted into the annulus intraoperatively. True annulus size was determined as the labeled size that just fits on the annulus, and labeled size plus 1 mm was determined as one that passes through the annulus. RESULTS: There was better agreement with minimal bias between CTpredict and true annulus size as demonstrated in the Bland-Altman analysis with an intraclass correlation coefficient of 0.796 compared with TTEpredict. CONCLUSION: ECG-gated CT is also helpful in predicting the annulus diameter even in patients undergoing SAVR. This has important clinical implications for planning SAVR, including the surgical approach.

Chronologic Changes in Residual False Lumen Under Continuous-Flow Circulation.

We experienced a rare case of intraoperative type A aortic dissection during HeartMate II (Abbott, Chicago, IL) implantation and subsequently performed emergent total aortic arch replacement. Periodic follow-up computed tomography confirmed that the residual false lumen after the aortic repair had gradually thrombosed over time regardless of sufficient antithrombotic therapy. We analyzed the chronologic changes in the false lumen morphology, showing transient enlargement of the aortic diameter 1 year postoperatively and then a reduction at 3 years postoperatively. We report on the fate of residual false lumen after aortic repair under continuous-flow left ventricular assist device circulation.

Determinants of Changes in Arterial Stiffness after Thoracic Endovascular Aortic Repair.

BACKGROUND: Aortic stent grafting can cause aortic stiffening and increase pulse wave velocity (PWV), which can potentially affect long-term cardiovascular outcomes. The aim of this study was to clarify the factors contributing to increases in PWV after thoracic endovascular aortic repair (TEVAR). METHODS: We included 64 patients with thoracic aortic pathology (51 men; mean age, 73 years) who underwent elective TEVAR, in this study. TEVAR was performed for degenerative aortic aneurysm (n = 43) or aortic dissection (n = 21), and the treatment length was 175 ± 52 mm. Brachial-ankle PWV (baPWV) was obtained before and 1 week after TEVAR. Univariable and multivariable logistic regression analyses were used to determine the predictors of increases in baPWV of ≥100 cm/sec after TEVAR. RESULTS: baPWV increased from 1,851 ± 392 cm/sec to 2,047 ± 479 cm/sec, and the change in baPWV (ΔbaPWV) was 195 ± 339 cm/sec (95% confidence interval, 111-280). Thirty-seven patients (58%) had ΔbaPWV ≥100 cm/sec after TEVAR. In the multivariable analysis, in addition to Δheart rate and Δsystolic blood pressure, age (odds ratio, 1.21/year; 95% confidence interval, 1.05-1.40) and coronary artery disease (odds ratio, 12.0; 95% confidence interval, 1.20-121) were independent determinants of ΔbaPWV ≥100 cm/sec after TEVAR, whereas ΔbaPWV ≥100 cm/sec was not associated with treatment length or device type. CONCLUSIONS: TEVAR was associated with PWV progression, especially in older patients with coronary artery disease, whereas treatment length or device type was not a predictor of PWV progression after TEVAR.

[The Perioperative Management and Operative Strategy for Prevention of Stroke in Cardiovascular Surgery].

Stroke is an important cause of morbidity and mortality after cardiovascular surgery and its incidence has been reported as 1.5 to 8.7%. Preexisting cerebrovasuclar disease, stenotic lesions of the carotid artery and atherosclerosis of the ascending aorta are known to be significant anatomic risk factors. To prevent perioperative stroke, it is important to discuss the onset mechanisms. Intraoperative stroke is mainly caused by the embolization of scattered atheroscrelotic plaque. Carotid duplex scanning and magnetic resonance imaging (MRI) are useful methods for the preoperative screening of cerebrovascular stenosis and plaque. Enhanced computed tomography (CT) is a powerful tool to estimate the presence of severe atheroscrelotic plaque in the aorta. When severe plaque is present, the manipulation, cannulation or clamping of the diseased aortic segment should be prevented. Insufficient oxygenated brain blood flow is thought to be another mechanism of intraoperative stroke. Impaired cerebral autoregulation during caridopulmonary bypass has been reported. Thus, it is recommended to maintain a high mean arterial pressure during cardiopulmonary bypass, especially in patients with cerebrovasuclar occlusive diseases. Postoperative stroke is mainly caused by embolization of the thrombus. To prevent this, excessive hypovolemia and atrial fibrillation should be avoided. Preemptive usage of beta blockers is one option for preventing postoperative atrial fibrillation.

Preoperative distal aortic diameter is a significant predictor of late aorta-related events after endovascular repair for chronic type B aortic dissection.

OBJECTIVES: Long-term therapeutic effects of thoracic endovascular aortic repair (TEVAR) for chronic type B aortic dissection remain controversial. This study aimed to evaluate the possible predictors of late aortic rupture and re-interventions after TEVAR. METHODS: We retrospectively reviewed the operative outcomes of 40 patients who underwent TEVAR for chronic type B aortic dissection at Kyushu University Hospital. During a mean follow-up period of 39.2 months, we assessed aortic morphology via computed tomography and then employed a multivariable Cox regression analysis in an attempt to identify the predictors of late aorta-related events. RESULTS: The early success rate of TEVAR was 100%. During the follow-up, however, three patients died from aortic rupture. Eight patients required aortic re-intervention, including thoraco-abdominal aortic graft replacement, repeated TEVAR, total arch replacement and EVAR. Multivariable Cox regression analysis revealed that the preoperative maximum distal aortic diameter was a significant predictor of late aorta-related events. The cutoff value of the distal aortic diameter was 40 mm. Freedom from aorta-related events was 94.6% at 1 year and 78.3% at 3 years. The survival rate was not significantly different despite the re-intervention. CONCLUSIONS: TEVAR is an effective treatment for chronic type B dissection, with acceptable mid-term results. The preoperative distal aortic diameter is a significant risk factor for late aorta-related events. When the maximum distal aortic diameter is ≥ 40 mm, a therapeutic strategy should be developed taking into consideration the possible need for aortic re-intervention.

Single-stage hybrid total arch replacement for extended arch aneurysms.

OBJECTIVE: The therapeutic strategy for extended aortic arch aneurysms remains controversial and has changed substantially since thoracic endovascular aortic repair was introduced. We applied single-stage hybrid (s-hybrid) total arch replacement (TAR), which involved ascending aorta replacement and debranching of arch vessels, consecutively performed with thoracic endovascular aortic repair for extended arch aneurysms. The aim of this study was to investigate the short-term results of s-hybrid TAR and to clarify the benefit of this method. METHODS: We reviewed the operative results of 62 patients who underwent elective s-hybrid TAR or conventional TAR (c-TAR) through the median approach from 2008 to 2017. We used the s-hybrid approach in 15 patients and the c-TAR approach in 47 patients. In both groups, axillary arterial perfusion and selective antegrade cerebral perfusion under moderate hypothermia were applied for brain protection. We compared the perioperative outcomes of the two groups. RESULTS: We completed s-hybrid TAR in all 15 patients with extended aneurysms. The s-hybrid group required shorter times for myocardial ischemia, selective antegrade cerebral perfusion, and circulatory arrest of the lower body compared with the c-TAR group. The patients with complicated recurrent laryngeal nerve palsy and long ventilation support times were fewer in the s-hybrid group. No patient had substantial endoleaks or permanent paraplegia. The in-hospital mortality rates were 6.7% in the s-hybrid group and 0% in the c-TAR group. CONCLUSIONS: The s-hybrid TAR has the same or better perioperative outcomes compared with the c-TAR approach. For extended aneurysms, this technique could resolve the problem of respiratory failure induced by left thoracotomy and also resolve the problem of rupture during the waiting period in staged surgery.

Single-Stage Hybrid Arch Repair for Patients with Shaggy Aorta.

Operating on extended arch aneurysms that contain severe atherosclerotic plaques is difficult. In such cases, the incidence of intraoperative multiple embolization is very high. We applied single-stage hybrid arch repair, which involved ascending aorta replacement and debranching of arch vessels, consecutively with endovascular repair for two patients. This technique was developed to prevent embolization of atherosclerotic plaques during cardiopulmonary bypass, and abrasion of the plaques during thoracic endovascular repair. Both patients recovered without embolic complications.

Comparison of cardiac energetics after transcatheter and surgical aortic valve replacements.

OBJECTIVES: The effect of transcatheter aortic valve replacement (TAVR) on cardiac energetics has not been described. We compared changes in cardiac energetics after TAVR with those after surgical aortic valve replacement (SAVR). METHODS: We retrospectively estimated end-systolic elastance (Ees) and effective arterial elastance (Ea) using blood pressure and left ventricular (LV) volume obtained from echocardiography. LV efficiency [ventriculoarterial coupling (Ea/Ees) and the stroke work to pressure-volume area ratio (SW/PVA)] was calculated. Measurements were taken before, 1 week after and 1 year after bioprosthetic aortic valve replacement (TAVR, n = 56; SAVR, n = 61) in patients with severe aortic stenosis and preserved ejection fraction. RESULTS: Patients with TAVR had a lower aortic valve pressure gradient and larger stroke volume 1 week after the procedure than those with SAVR. Ea was more markedly decreased, and LV efficiency was significantly improved 1 week after TAVR (SW/PVA 68.1% ± 8.4% to 72.0% ± 8.5%, P < 0.001), but LV efficiency was unchanged 1 week after SAVR (SW/PVA 70.1% ± 7.4% to 69.1% ± 8.0%). LV efficiency was improved 1 year after both procedures (SW/PVA 75.5% ± 6.1% in TAVR; 74.7% ± 6.4% in SAVR). CONCLUSIONS: TAVR decreases the transvalvular pressure gradient further without deteriorating stroke volume in the early postoperative period, which is accompanied by early improvement in afterload and LV efficiency compared with SAVR. Improvement in LV efficiency at mid-term follow-up is satisfactory after both procedures.

Thoracic endografting increases cardiac afterload and leads to left ventricular hypertrophy in dogs.

OBJECTIVES: Aortic endografting can cause aortic stiffening. We aimed to determine the chronic effect of thoracic endografting on cardiac afterload, function and remodelling. METHODS: Eleven dogs were included, and all except 1 was successfully assessed [endograft, n = 5; sham operation (control), n = 5]. We deployed a stent graft in the descending aorta. The ascending aortic pressure and flow were measured, and aortic input impedance was obtained by frequency analysis to determine characteristic impedance and arterial compliance. Left ventricular pressure-volume relations were measured with an admittance catheter. Measurements were performed before, 10 min after and 3 months after endografting. Following euthanasia, we weighed the left ventricle of each dog and measured the cardiomyocyte cell size. RESULTS: Arterial compliance decreased from 0.47 ± 0.07 to 0.36 ± 0.06 and to 0.31 ± 0.05 ml/mmHg (both P < 0.01 versus baseline), and characteristic impedance increased from 0.11 ± 0.04 to 0.19 ± 0.05 and to 0.21 ± 0.04 mmHg/ml/s (both P < 0.01 versus baseline) 10 min and 3 months after endografting, respectively. Pressure-volume relation analysis showed that arterial elastance increased from 5.3 ± 1.0 to 6.7 ± 1.6 (at 10 min) and to 6.8 ± 1.0 mmHg/ml (at 3 months) (both P < 0.05 versus baseline), but end-systolic elastance and ventriculo-arterial coupling remained unchanged. Left ventricular weight to body weight ratio and left ventricular cardiomyocyte cell width in the endograft group were larger compared with the control's results (5.06 ± 0.27 g/kg vs 4.20 ± 0.49 g/kg, P = 0.009, 15.1 ± 1.7 µm vs 13.9 ± 1.5 µm, P = 0.02, respectively). CONCLUSIONS: The mid-term effect of the descending aortic endografting on left ventricular contractility and efficiency in canine normal hearts was minimal. However, endografting resulted in increased cardiac afterload and left ventricular hypertrophy.

Agenesis of hepatic lobes in a dog.

Agenesis of a hepatic lobe is an extremely rare congenital anomaly and only one dog have been reported in veterinary literature. We encountered a dog with this anomaly diagnosed by Computed tomography (CT) and portography. A two-year-old, 6.9-kg female Shih tzu dog was presented with vomiting and anorexia. The dog had no history of abdominal surgery or trauma. Biochemical analysis showed elevated plasmatic liver enzymes. CT revealed the absence of the liver parenchyma and vascular system of the left lobe, quadrate lobe and papillary process of the caudate lobe. A portosystemic shunt was also observed. The liver parenchyma and vascular system of these lobes were not detected under digital subtraction angiography during laparotomy. Furthermore, the liver parenchyma and vascular system of these lobes were not detected even when the remaining liver volume increased two months after treating the shunt vessel. CT proved itself a good option for antemortally diagnosis of hepatic agenesis in a dog.

Transcatheter arterial embolization in normal canine liver.

OBJECTIVE: To determine the effects of selective transcatheter arterial embolization (TAE) in the normal canine liver. STUDY DESIGN: Experimental study. ANIMALS: Adult Beagle dogs (n = 5). METHODS: Gelatin sponge particles (GSPs) were injected through a microcatheter for selective embolization of the left hepatic artery in normal dogs. Computed tomography (CT) and histology were performed during an 8-week observation period; biochemical analysis data were obtained during a 12-week observation period after TAE. RESULTS: Embolization was successful in all dogs and did not induce any change in the clinical appearance of dogs. Postoperative CT was consistent with recanalization of the artery within 2 weeks of embolization in all dogs. Hepatic enzyme levels increased temporarily after embolization but gradually returned to normal ranges. Histological examinations did not differ between treated and untreated liver tissues. CONCLUSION: TAE appears safe in normal dogs observed for 12 weeks. Arterial recanalization seems to occur within 2 weeks after injection of GSPs in the left hepatic artery. IMPACT/CLINICAL RELEVANCE: Selective TAE of the hepatic artery was well tolerated in normal dogs. Selective TAE may be applicable to canine hepatocellular carcinoma.