Arterial Collaterals in the Liver Hilus

Abstract

Arterial collaterals in the hilus of the liver may develop in a variety of clinical situations including neoplasm, atherosclerosis, operative ligation and other vascular stenoses, and cirrhosis. They are normally present but are not demonstrated angiographically unless they are functioning as collaterals. Hilar collaterals are an important factor in maintaining liver viability following accidental or purposeful hepatic arterial ligation. The authors base their discussion on personal experience with 16 cases. INDEX TERMS: Liver, blood supply. Arteries, hepatic Radiology 94: 575-579, March 1970 T H E POSSIBILITIES for the development of collateral blood flow to an occluded hepatic artery depend primarily on the site of the occlusion (3). If the celiac or common hepatic artery is occluded, several potential routes exist for collateral circulation (1,4). The main pathway is through the pancreaticoduodenal arcades and the gastroduodenal artery. With proper hepatic artery occlusion, these major collateral channels cannot be utilized, and the liver becomes dependent upon small collaterals in the hepatic ligaments and around the common bile duct. If the occlusion is located in the right or left hepatic arteries or their branches, collateral vessels may develop between these arteries in the hilus of the liver. These hilar communications between hepatic arteries are an important but poorly recognized entity. We are, therefore, presenting 16 patients in whom such collaterals were demonstrated at angiography. METHODS AND MATERIALSThe 16 patients underwent celiac and superior mesenteric angiography for a variety of reasons. The angiograms were obtained by the percutaneous femoral technique, using thin-walled, red Kifa catheters (LD./O.D. = 1.4/2.2). Renografin 76 per cent (Squibb) was injected into the celiac and superior mesenteric arteries at a rate of 12 ml/sec. for three seconds, and serial films were obtained at 2 per second for five seconds, 1 per second for five seconds, and 1 every other second for ten seconds. The angiograms were evaluated to determine (a) the direction of the blood flow through the collateral vessels and (b) the cause for the development of the collateral flow. In addition, the relevant visceral vascular anatomy and its contribution to the pattern of development of collateral flow were assessed. RESULTSHilar collaterals developed subsequent to vascular stenosis in 7 patients, to operative ligation in 5, to tumor in 2, and to cirrhosis in 2. The vascular stenoses were secondary to atherosclerosis in 4 patients, but in 3 younger patients they were probably caused by diaphragmatic crus or were congenital. The operative stenoses were seen in 3 patients following liver resection

Liver blood supply after a modified Appleby procedure in classical and aberrant arterial anatomy

“…Angiography demonstrated the interlobar branch-relayed collateral blood flow between the hepatic arteries [31][32][33][34][35][36][37] to be readily noted at the occlusion of either of the hepatic arteries [32,33,37] , which was demonstrated by computerized tomographic angiography in our Case 2 ( Figure 11). The interlobar arterial collaterals may be responsible for the poor distribution of a chemotherapeutic agent at its selective intraarterial infusion [32] . Injuries to these collateral pathways, participating in the blood supply of the hilar bile ducts, may induce ischemia of the biliary tract after liver resections and biliary surgery [28,29] .…”

“…Injuries to these collateral pathways, participating in the blood supply of the hilar bile ducts, may induce ischemia of the biliary tract after liver resections and biliary surgery [28,29] . The majority of investigators are in agreement that the interlobar collateral is extraparenchymal, passes cranial to the bifurcation of the PVs in the hepatic hilum in close proximity to the bile ducts [32,33,[37][38][39][40] and makes the crucial contribution of the blood supply to the biliary tract, as well as one of the hepatic lobes in the event of liver major route interruption [29,36,37,41] . So far it has not been clear whether there are transparenchymal branches to connect the hepatic lobes [31,33,36,42] .…”

“…The development of collateral blood flow with one of the hepatic arteries being occluded was shown to be a possibility and to depend heavily on the site of vascular obstruction [26,27] . Hepatic interlobar arterial collaterals were exhaustively analyzed in autopsied specimens and corrosion casts [26][27][28][29][30] , as well as with radiological studies [31][32][33][34][35][36][37] called into being by the evolution of hepatic surgery, transplantation, interventional radiology, endovascular chemotherapy and embolization. Angiography demonstrated the interlobar branch-relayed collateral blood flow between the hepatic arteries [31][32][33][34][35][36][37] to be readily noted at the occlusion of either of the hepatic arteries [32,33,37] , which was demonstrated by computerized tomographic angiography in our Case 2 ( Figure 11).…”

Intersegmental Arterial Communication between the Medial and Left Lateral Segments of the Liver

“…The interlobar arterial collateral of the liver has been thoroughly analyzed using both anatomical [12, 13] and radiological studies [14,15,16]. Our previous study showed that the communicating arcade between the right and left hepatic arteries was consistently present in the hilar plate and played an important role not only in the interlobar arterial collateral system of the liver but also in the blood supply to the hilar bile ducts [17].…”

Anastomosen zwischen Segmentarterien der Leber und phrenico-hepatische arterio-arterielle Anastomosen

“…sinistra als relativ risikoarme Therapie sonst unkontrollierbarer Blutungen nach Leberverletzungen. Anastomosen am Leberhilus k6nnen dann eine ausreichende Blutversorgung des betroffenen Leberlappens von der Gegenseite her gewfihrleisten [17].…”