Inferior phrenic arteries: angiographic anatomy, variations, and catheterization techniques for transcatheter arterial chemoembolization

A morphological study of the inferior phrenic arteries on multidetector computed tomography and angiography

INTRODUCTION

The inferior phrenic artery is a paired artery with a variable origin and course, primarily supplying the diaphragm, but also the suprarenal glands, inferior vena cava, stomach, and oesophagus. The aim of this study is to investigate the origin and course of the inferior phrenic arteries on multidetector computed tomography and angiography.

MATERIALS AND METHODS

The anatomy of the inferior phrenic artery was analysed on 2449 multidetector computed tomography scans. Three-dimensional reconstructions were made of the main variations. Additionally, the course and branching pattern of the inferior phrenic artery were descriptively analysed in a cohort of 28 angiograms.

RESULTS

In 565 (23.1%) cases the inferior phrenic arteries arose as a common trunk and in 1884 (76.9%) cases as individual vessels. The most common origins of a common trunk were the coeliac trunk (n=303; 53.6%) and abdominal aorta (n=255; 45.1%). The most common origins of the right inferior phrenic artery were the coeliac trunk (n=965; 51.2%), abdominal aorta (n=562; 29.8%) and renal arteries (n=214; 11.4%). The most common origins of the left inferior phrenic artery were the coeliac trunk (n=1293; 68.6%) and abdominal aorta (n=403; 21.4%).

CONCLUSION

The inferior phrenic artery has a very variable anatomy. The most common origins of the inferior phrenic artery are the coeliac trunk and its branches, the abdominal aorta, and the renal arteries.

Selection of the right inferior phrenic artery using a dual-lumen microcatheter in transarterial chemoembolization for hepatocellular carcinoma

An 88-year-old woman with a history of multiple hepatocellular carcinomas (HCCs) presented with a new HCC in segment seven of the liver. We decided to perform transarterial chemoembolization for HCC. During treatment, the HCC was supplied by the right inferior phrenic artery (IPA), which originated from the proximal part of the left gastric artery with a steep bifurcation angle. Due to the very short distance between the origins of the left gastric artery and right IPA, the microguidewire and microcatheter were unstable in the left gastric artery and easily prolapsed into the celiac artery. Although different types of microcatheters were used, the right IPA could not be selected. Therefore, we used a dual-lumen microcatheter (DLM) to select the right IPA. The DLM stabilized the microguidewire in the left gastric artery, and the right IPA was successfully selected. Subsequently, transarterial chemoembolization was administered using a branch of the right IPA. Given this experience, we will consider using a DLM as an alternative method for selecting an abdominal artery when other techniques are unsuccessful.

Hepatocellular Carcinoma With Different Areas of Right Retroperitoneal Space Invasion: Evaluation of Transcatheter Arterial Chemoembolization Efficacy and Blood Supply Characteristics

Purpose

To evaluate the therapeutic efficacy of transcatheter arterial chemoembolization (TACE) for hepatocellular carcinoma (HCC) with different areas of right retroperitoneal space (rRPS) invasion and analyze the blood supply.

Methods

This retrospective study enrolled 41 patients with HCC with different areas of rRPS invasion treated with TACE, including 22 HCCs with superior aspect of the right perirenal space (SARPS) invasion and 19 HCCs with right anterior pararenal space (RAPS) invasion. The overall response rate (ORR) and disease control rate (DCR) were analyzed. The prognostic factors for overall survival (OS) after TACE were determined. The blood supply characteristics of HCC with different areas of rRPS invasion were analyzed with arteriograms.

Results

All patients underwent 2.8 ± 1.8 TACE sessions over 25.0 ± 21.9 months. The median OS was 29.0 months for patients with SARPS invasion and 12.0 months for patients with RAPS invasion (P = 0.004). Only the invaded area of the rRPS was an independent prognostic factor for OS [hazard ratio (HR), 2.833; 95% CI, 1.297–6.188; and P = 0.009). The ORR and DCR were significantly higher in the group with SARPS invasion than in the group with RAPS invasion (ORR: 63.6% vs 31.6%, P = 0.041; DCR: 77.3% vs 47.4%, P = 0.047). Initially, HCC with SARPS invasion were supplied by the hepatic artery (HA; n = 8) and both the HA and extrahepatic collateral vessels (EHCs; n = 14); HCC with RAPS invasion were supplied by the HA (n = 10) and both the HA and EHCs (n = 9); as the TACE sessions increased, the tumor-feeding vessels shifted from the HA to both the HA and EHCs, and even EHCs could be the only blood supply. Rare EHCs appeared earlier and more frequently in the RAPS group than in the SARPS group.

Conclusion

The efficacy of TACE differed for HCC with different areas of rRPS invasion, and the median OS, ORR and DCR were significantly better in the SARPS group than in the RAPS group. Different common EHCs supplied HCCs with different areas of rRPS invasion, while other rare EHCs appeared more frequently in the RAPS group.

Blood supply to the caudate lobe of the liver from the right inferior phrenic artery: observation by cone-beam computed tomography during arteriography

PURPOSE

To retrospectively evaluate blood supply to the caudate lobe of the liver from the right inferior phrenic artery (RIPA) using cone-beam computed tomography during arteriography (CBCTA-RIPA).

METHODS

CBCTA-RIPA examinations during transarterial chemoembolization (TACE) for hepatocellular carcinoma (HCC) were collected from 2448 procedures in 787 patients. The exclusion criteria were (1) major artifacts, (2) TACE of hepatic arterial branches before performing CBCTA-RIPA, and (3) repeated CBCTA-RIPA studies in the same patient. Blood supply to three subsegments, the Spiegel lobe (SP), paracaval, and caudate process, was evaluated on CBCTA-RIPA images. The origins and routes of branches supplying the caudate lobe were also evaluated by three-dimensional vessel-tracking software.

RESULTS

Forty-seven CBCTA-RIPA examinations in 47 patients (38 with a history of TACE [repeated TACE group] and nine without it [initial TACE group]) were eligible, including five who had previously undergone hepatectomy. Seven had caudate lobe HCCs. Blood supply to the caudate lobe was demonstrated in 21 (44.7%) patients: in 50% (19/38) and 22.2% (2/9) of the repeated and initial TACE groups, respectively. The caudate arteries had previously been embolized in eight patients, the RIPA branch in three, and both in one. Forty-one proximal branches mainly supplied the dorsal part of the SP. All branches but five reached there through the inferior vena cava (IVC) ligament. The RIPA supplied eight of nine caudate lobe HCCs, totally (n = 7) or partially (n = 1).

CONCLUSION

The proximal RIPA branches mainly supply the dorsal SP through the IVC ligament, especially in the repeated TACE group.

Shaping the tip of microcatheters for superselective catheterization: steam vs. manual methods

PURPOSE

We aimed to evaluate and compare the shapeability and stability of five microcatheters commonly used in interventional radiology after steam shaping and manual shaping.

METHODS

Steam shaping was performed using three mandrels of different angles: L(S) shape (90°), U(S) shape (180°), and O(S) shape (360°). Three manual shapes-L(M), U(M), and O(M)-were made to have a similar angle to their steam-shaped counterparts. The stability of the microcatheters was evaluated by passing them through a 5 F catheter and inserting microguidewires. The tip angles of the microcatheters and the angle change rates were compared between groups.

RESULTS

The mean angle of the microcatheters after steam shaping was 42.4°-54.1° for L(S) shape, 80.2°-96.7° for U(S) shape, and 130.7°-150.8° for O(S) shape. Five microcatheters showed significantly different mean angle reductions after passing through the 5 F catheter (17.4%-30.3%) and inserting microguidewires (24.1%-61.2%). Different microguidewires also caused significantly different mean angle reductions (34.6%-50.8%). The reduced angle caused by the guidewire was almost completely recovered after withdrawing it (93.2%-101.6%). Although manual-shaped microcatheters showed a 4.2%-6.3% greater angle reduction than steam-shaped microcatheters after passing through the 5 F catheter, the final tip angle was not significantly different between the two groups and was within 10%.

CONCLUSION

The tip angle of the microcatheters after steam shaping using mandrels may differ depending on the shape of the mandrel and the type of microcatheter used, and the stability varies depending on the type of microcatheter. The manual shaping of microcatheters can be a good alternative to steam shaping.

Isolated Arteries Originating from the Intrahepatic Arteries: Anatomy, Function, and Importance in Intervention

Isolated hepatic arteries are defined as hepatic terminal arterioles that are not accompanied by portal venules or bile ductules and penetrate the liver parenchyma and distribute to the hepatic capsule and intrahepatic hepatic veins. Abundant communications exist between intra- and extrahepatic arteries through isolated arteries and capsular arterial plexus. They play a principal role in the development of subcapsular hemorrhage and arterial collateral formation following transcatheter arterial chemoembolization for liver cancers. The anatomy, function, and clinical importance of isolated hepatic arteries in interventional radiology, especially regarding subcapsular hemorrhage and arterial collateral formation, are highlighted in this article.

Evaluation of extrahepatic collateral arteries in hepatocellular carcinoma in three independent groups in a single center

To improve the efficacy of transcatheter arterial chemoembolization (TACE) for hepatocellular carcinoma (HCC), this study evaluated the prevalence and causes of extrahepatic arteries (EHAs) and identified feeding arteries in HCCs in three independent clinical groups in a single inverventional radiology center. Between November 2011 and September 2012, 942 cases of HCC were included in this retrospective study. The patients were treated in three independent groups of 285, 301 and 356 patients, respectively. Enhanced computed tomography, enhanced magnetic resonance imaging and digital subtraction angiography were reviewed retrospectively and correlations between the presence of tumor-feeding EHAs and tumor number, size and location in the liver, number of repeat TACE procedures and complications were assessed. There were 698 EHAs in the 942 cases of HCC, with 182, 233 and 283 EHAs in the three independent groups, respectively. Tumor size was associated with EHA formation; the percentages of patients with EHAs were 2.7±3.0, 5.5±0.5, 43.2±4.0, 61.8±5.2 and 93.4±1.8% with tumor sizes of 2-3, 3-5, 5-7, 7-9 and >9 cm, respectively. There were 159±19 EHAs in each group feeding tumors in peripheral locations in the liver, but only 48.7±6.8 in the central zone. The most common EHA was the right inferior phrenic artery, with a mean of 101.0±14.1 per group. The number of EHAs increased proportionally with the number of TACE sessions. The number of EHAs was positively associated with tumor size, peripheral location of the tumor and number of TACE sessions.

Origin of the celiac and superior mesenteric arteries in a common trunk: description of a rare vessel variation of the celiacomesenteric trunk with a literature review

A variation artery was observed in a Japanese cadaver. The celiac and superior mesenteric arteries arose from a common trunk (also referred to as the celiacomesenteric trunk), but not from the abdominal aorta, respectively. From the common trunk, the common hepatic artery was distributed in the right part of the liver, and the left hepatic artery arose from the left gastric artery, which also arose from the common trunk. The left inferior phrenic artery arose from the common trunk, but the right inferior phrenic artery arose from the right middle suprarenal artery. This information regarding the branch pattern in this variation artery is useful for clinical examination and treatment.

Inferior Phrenic Arteries and Their Branches, Their Anatomy and Possible Clinical Importance: An Experimental Cadaver Study

BACKGROUND

Transcatheter arterial chemoembolization is a common treatment for patients with inoperable hepatocellular carcinoma. If the carcinoma is advanced or the main arterial supply, the hepatic artery, is occluded, extrahepatic collateral arteries may develop. Both, right and left inferior phrenic arteries (RIPA and LIPA) are the most frequent and important among these collaterals. However, the topographic anatomy of these arteries has not been described in detail in anatomy textbooks, atlases and most previous reports.

AIMS

To investigate the anatomy and branching patterns of RIPA and LIPA on cadavers and compare our results with the literature.

STUDY DESIGN

Descriptive study.

METHODS

We bilaterally dissected 24 male and 2 female cadavers aged between 49 and 88 years for this study.

RESULTS

The RIPA and LIPA originated as a common trunk in 5 cadavers. The RIPA originated from the abdominal aorta in 13 sides, the renal artery in 2 sides, the coeliac trunk in 1 side and the left gastric artery in 1 side. The LIPA originated from the abdominal aorta in 9 sides and the coeliac trunk in 6 sides. In 6 cadavers, the ascending and posterior branches of the LIPA had different sources of origin.

CONCLUSION

As both the RIPA and LIPA represent the half of all extrahepatic arterial collaterals to hepatocellular carcinomas, their anatomy gains importance not only for anatomists but interventional radiologists as well.

Variant arterial supply to the lesser curvature of the stomach and duodenum from double inferior phrenic arteries

A rare case of the left accessory inferior phrenic artery (IPA) supplying the lesser curvature of the stomach and the right accessory IPA supplying the duodenum was observed during interventional radiography. To our knowledge, variation arteries supplying the stomach and duodenum have never been reported in English literature; herein, we report the first case of variant arterial supply to the lesser curvature of the stomach and duodenum from double IPAs.

Arterial blood supply to the caudate lobe of the liver from the proximal branches of the right inferior phrenic artery in patients with recurrent hepatocellular carcinoma after chemoembolization

PURPOSE

To evaluate the arterial blood supply to the caudate lobe of the liver from the proximal branches of the right inferior phrenic artery (RIPA) in patients with recurrent hepatocellular carcinoma after transcatheter arterial chemoembolization (TACE).

MATERIALS AND METHODS

Thirteen patients, including 10 who had a history of TACE of the caudate artery (A1), underwent TACE of the proximal RIPA branches. Iodized oil distribution was evaluated by computed tomography (CT) 1-week after TACE. Angiographic findings were also evaluated.

RESULTS

Previously embolized A1 was occluded (n = 15) or attenuated (n = 2). In one of three patients without A1 TACE, A1 was also attenuated. TACE was performed at the first branch of the proximal RIPA (n = 8), the first branch of the anterior branch (n = 6), and the first branch of the posterior branch (n = 1), respectively. Iodized oil was mainly distributed into the dorsal part of the Siegel lobe (SP) (n = 10), the caudate process (n = 1), and both (n = 2). In three of seven patients who had undergone serial RIPA angiography, RIPA parasitization to SP was suspected before A1 TACE.

CONCLUSION

The proximal RIPA branches mainly supply the SP when A1 is attenuated.