Sinistroposition of the gallbladder and the common bile duct.

A left lateral bisegmentectomy was performed in a 29-year-old man presenting a primary lymphoma of the liver. Surgical exploration revealed a left-side gallbladder, located under the left lobe of the liver. During hepatic parenchyma dissection, performed strictly at the left of the round ligament and the umbilical portion of the left portal vein, common bile duct was injured. Complete separation of hepatic pedicle structures showed that the upper biliary convergence passed on the left side of the umbilical portion of the left portal vein before reaching the hepatoduodenal ligament. This case report discusses the embryological mechanism that could explain this uncommon bile duct abnormality, focusing on its consequences during left ruled lobectomy.

[Errors in the topographic diagnosis of liver diseases]. / Erreur dans le diagnostic topographique des lésions hépatiques.

To identify the portal pedicles in liver pathology is difficult: anatomical variations are ignored and only the modal disposition is retained, the obliquity of the liver in situ is ignored: strongly inclined to the right, posteriorly and inferiorly (the anterior sector is above and to the right of the posterior sector, their pedicles in an antero-posterior radiogram are superposed); and the sizes of segments IV and VI are quite variable (embryologic result). This study was made with a collection of 111 vasculo-biliary acrylic casts. The main portal fissure containing the middle hepatic vein follows the axis of the cystic fossa. Actually the position of this axis varies from 18 degrees to the right of the vein (gall-bladder under segment V) and 14 degrees to the left (gall-bladder under segment IV); the fissure reaches the inferior vena cava only at the limit of the upper surface of the liver, the vena cava is separated from the right and left livers by the dorsal sector. The anterior half of the right portal fissure is quite variable, it can reach the anterior liver from the main portal fissure up to the anterior portion of the right margin of the liver (segment VI variation); in 41% of the livers (n = 100), the right hepatic vein is in the right portal fissure; occlusion of the anterior or the posterior right arteries indicates the fissure. The left portal fissure is often confused with the left hepatic fissure (limit between academic left and right lobes). Segments breadths are measured in the upper surface of the liver. The largest segments are VIII, V, III and II; their transversal breadth is also the largest (simple to double). In difficult cases, a tri-dimensional reconstruction of the pedicles should be made from an helicoïdal tomodensitometry.

The dorsal sector of human liver: embryological, anatomical and clinical relevance.

The dorsal liver sector has been recognized as the parenchyma surrounding the vena cava and is quite independent of the remaining liver. It is that part of the organ in which the hepatic portion of the vena cava develops and its venous outflow remains strictly connected with the vena cava by means of multiple, not dissectable effluents as well as with the main hepatic veins. Therefore, this sector is a major shunt between the main hepatic veins and the inferior vena cava, which enlarges and ensures venous drainage for survival in cases of Budd-Chiari syndrome. The dorsal sector consists of two segments: a left one (segment I) corresponding roughly to the caudate lobe and a right one (segment IX) in front and on the right of the vena cava, including the so-called caudate process. The identification of a dorsal liver sector and its detailed anatomy is of primary importance for surgical practice, since cholangiocarcinoma of bile duct hilar confluence extends to the dorsal sector and makes resection of this sector necessary for efficient therapy and due consideration of the pedicles of segment I and IX is required to perform successful hemihepatectomy as well as liver partition for split liver grafting.

Liver anatomy: portal (and suprahepatic) or biliary segmentation.

BACKGROUND/AIMS: In liver anatomy and surgery, is portal and hepatic vein segmentation (French segmentation) to be preferred over arteriobiliary segmentation (Healey and Schroy, North American segmentation)? METHODS: Several embryological arguments and an analysis of anatomical data from a personal collection of 110 vasculobiliary casts were made. RESULTS: Embryological arguments: Portal vein branching appears first, arteriobiliary branching secondly follows the portal vein distribution. Segment II (the left lateral sector) is the development of the right lateral embryological lobe. The umbilical vein enters the left portion of the middle embryological lobe, forming segment IV on the right and segment III on the left: this is the left paramedian sector. So the left portal fissure (between left and middle lobes) transversally crosses the classical left lobe, which is not a portal unit. Segment VI is a late secondary prominence of segment VII, reaching the anterior margin of the liver only in man. Anatomical arguments: hepatic vein segmentation must be added to portal segmentation; the academic left lobe is the left hepatic vein sector, and the left hepatic fissure separates the classical right and left lobes. Portal vein segmentation must be preferred: portal vein duplication of branches of first order occurs only in 23.5% of the cases, while arteriobiliary duplication of first-order branches is noted in 50% of the livers, portal segmentation being much simpler. CONCLUSIONS: Portal and hepatic vein segmentation seems to be much more accurate.

[Dorsal sector of the liver]. / Secteur dorsal du foie.

The dorsal sector extends in front and to the sides of the inferior vena cava, separating the caval axis from the main liver (excepting superiorly the entrance of the main hepatic veins into the vena cava). The two elements, dorsal sector and retro-hepatic portion of the vena cava, actually make a single unit. It is made of two segments: left (segment I) larger than the Spieghel lobe, right (segment IX) incorporated in the posterior surface of the right liver. The "caudate process" is not a peculiar element: it is nothing else than the inferior margin of segment IX: the breadth gives information on the size of segment IX. The dorsal sector is the midportion of the posterior liver, it is absolutely independent of the right and left livers separated by the main portal fissure. Portal pedicles are numerous and ascendant, they arise from the posterior margin of the transverse portal arch (from right to left: segment VII vein, right lateral vein, right portal vein, left portal vein, segment II vein). The size of the dorsal sector is variable, and can be appreciated by an antero-posterior index. A voluminous sector may be a problem for the surgeon. Segment IX can be divided in three subsegments: IXb under the interval between the right superior hepatic vein and the middle hepatic vein (longer branches can ascend and supply a small portion of the upper surface in front of the vena cava), IXc under the very broad right superior vein, and posteriorly IXd, linked to segment VII. Only segment I and subsegment IXb receive branches from the right and from the left livers. Hepatic veins enter directly the caval axis, some enter the main hepatic veins. The dorsal sector is a large anastomosis between efferent veins and the vena cava. Anteriorly segment I is in contact with segment IV but also with segment VIII, subsegments IXb and IXc with segment VIII and IXd with segment VII. The fissural limit is difficult to locate. Posteriorly division of the triangular and coronary ligaments, section of the dorsal hepatic veins, the right middle and inferior veins allow separation of the liver from the posterior abdominal wall and the inferior vena cava, so the surgeon can reach the dorsal sector. A remarkable error has been commited when the main hepatectomies were described: the dorsal sector was not known and the caudate lobe was considered as a part of the left liver. Actually the dorsal liver is a separate entity covering the inferior vena cava which has no connexion with the main liver; when the main portal fissure is opened up to the anterior surface of the vena cava, the dorsal sector is opened vertically. Interruption of the pedicles must also be considered. For example, in a left hepatectomy, the left portal pedicle is divided, all the left branches for subsegment IXb (which will be preserved) are interrupted; but the left branches from the right portal pedicle are not interrupted and will bleed when the dorsal sector is divided. When splitting the liver for transplantation, some difficulties can occur, especially with the right transplant. A main practical interest is the possible propagation to the dorsal ducts of hilar carcinoma.

New look on resection of segment VII of the human liver

Sao reconhecidos tres subsegmentos hepaticos (IXb, IXc e IXd), dos quais os dois ultimos devem ser bem identificados na resseccao do segmento VII. As relacoes anatomicas , os limites, os pediculos portais, o pediculo normal e as veias hepaticas tem grande importancia cirurgica. O eixo portal transverso, a identificacao dos pediculos e a posicao das fissuras devem ser conhecidas, principalmente nas segmentectomias parciais superiores. Ultra-sonografia e disseccao cuidadosa sao os recursos disponiveis para resolver dificuldades emergentes de variacoes anatomicas.

[Intrahepatic anatomy. Application to liver transplantation]. / Anatomie intra-hépatique. Application à la transplantation du foie.

In transplantation of the whole liver, the variable shape of the organ can exceptionally be the source of difficulties, as in the rare cases of situs inversus. Arterial variants may be the source of great difficulties. Among the biliary variants, the low junction of the right and left hepatic ducts in the main portal pedicle, and especially the cysto-hepatic ducts (entrance of a right duct into the gallbladder or the cystic duct) are particularly important, with a frequency ranging from 2 to 15% of the cases. Right liver--left liver, or right liver--left lobe bipartition is now a well controlled technique. Right lobe, left lobe bipartition should never be performed. The left hepatic vein is attributed to the left transplant (left liver or left lobe). In case of duplication of the left vein, the terminal portion of the middle vein is attributed to the left transplant, and the continuity of the middle vein with the inferior vena cava must be reconstructed. The middle vein is always attributed to the right transplant. When the portal bifurcation is missing, usually bipartition is impossible. When the right portal vein is duplicated, the portal stem is attributed to the right liver. Duplications of right and left arteries and ducts make difficulties. A thorough preoperative investigation is necessary in case of a living donor. Cholangiography and arteriography on the back table are essential to achieve an ex vivo bipartition. The surgeon then disposes of three manoeuvres: resection of segment IV, attribution of a short segment of the main duct on the side of a biliary duplication, attribution of the main hepatic artery (or the celiac axis) on the side of a left transplant (left liver or left lobe) is possible in 86% of cases, ex vivo is possible in 95. 70% of cases. Tripartition of the liver is not yet a controlled technique.

[A "scandal": segment IV and liver transplantation]. / Un scandale: segment IV et transplantation du foie.

Partition right-left lobes keeps segment IV in continuity with the right liver, but interrupts its portal elements which arise from the left portal pedicle. A precise anatomical investigation shows that the venous inflow is totally interrupted. In 12.15% of the cases (n = 107) the biliary duct from segment IV enters close to the upper biliary confluent, into the confluent or the main duct, and can be preserved in such a bipartition; in all other cases the segment is no longer in function and doomed to atrophy. In 10.75% of the livers (n = 99), the segmental artery comes from the right hepatic stem, and the segment is correctly vascularized; but in most cases interruption of both the artery and the portal branches leads to immediate necrosis, which may be lethal. Preservation of both artery and biliary ducts is possible in only 2.15% of the cases (n = 93 casts with correct injection of arteries and ducts). Consequently the partition right-left lobes is possible in only a few cases: cholangiography and arteriography detect the favourable dispositions. In all other cases such partition is forbidden. Procurement of the left lobe from a living donor with preservation of segment IV is rarely possible, such cases being detected by a thorough pre-operative vasculo-biliary investigation: the left lobe is harvested, and segment IV left in situ (2.15% of the cases). Usually the prospective of rapid necrosis or secondary atrophy commands resection of the segment.(ABSTRACT TRUNCATED AT 250 WORDS)

[Absence of portal bifurcation]. / Absence de la bifurcation porte.

Since the first description in 1957, absence of the portal bifurcation has been reported by four different teams, which makes a total of 5 cases and a frequency of 1.90%. Serious complications may occur postoperatively, and this anomaly should be systematically detected. There is a huge portal ring: the main vessel enters the liver, looking like a large right paramedian vein, turns to the right within the parenchyma, reaches the umbilical fissure to send the usual branches of REX' recessus, and ends as a terminal branch for the caudate lobe. The right lateral vein appears as a collateral. Numerous anterior and posterior branches supply segments IV, V and VIII. Two main facts: the portal ring turns around the axis of the middle hepatic vein, which is in the center of the ring. There is a rupture in the portal triad of the left portal pedicle: the vein is intra-hepatic, the artery and biliary duct lie normally in the hilum. The detection of this anomaly should always be done by portography or ultra-sonography. When operating, it is easily detected: there is no portal bifurcation and the left portal vein is missing. The main difficulty is to perform a right hepatectomy. After total vascular by-pass, the portal system is skeletonized and resection achieved. Another solution is to interrupt the portal stem deep in the hilum, divide the main portal fissure along the right margin of the middle hepatic vein and cut the transversal portion of the portal ring.(ABSTRACT TRUNCATED AT 250 WORDS)

Controlled liver splitting for transplantation in two recipients: technique, results and perspectives.

A technique of controlled liver splitting for transplantation in two recipients is proposed, based on a full anatomical assessment of the graft including arteriography and cholangiography on the back-table. Using eight livers, 16 patients received a graft: right liver (eight patients), left lobe (four) or left liver (four). Twelve patients required urgent or very urgent transplantation. Anatomical assessment of the graft demonstrated a portal bifurcation in all cases, a common trunk of the left and middle hepatic veins in five, a right biliary duplication in three and duplication of the left branch of the middle hepatic artery in one. After revascularization of the graft, bleeding was greater in patients with a right graft, particularly if the middle hepatic vein had been ligated. The main postoperative complications were hepatic artery thrombosis (four cases), biliary complications (four), portal vein thrombosis (two), haematoma (two) and abscess (two). No primary non-function of the graft was observed. The postoperative survival rate was 75 per cent. The four patients in whom transplantation was not considered urgent are still alive. The immediate survival rate of the grafts was 69 per cent. These results compare favourably with those in the literature. In spite of the technical, logistical and ethical problems raised by this technique, the results suggest that controlled liver splitting for transplantation in two recipients may in the future significantly improve the feasibility of liver transplantation.

[Variations of the right bile ducts. The futility of complete anatomical classifications]. / Les variations des canaux biliaires droits. De la vanité des classifications anatomiques complètes.

Combination calculus shows that there is a considerable number of theoretical variations of the right ducts: [table: see text] Complete classification is therefore impossible, and the different frequencies of these variations in different series are easy to understand. Probably some of these theoretical distributions do not actually exist. A classification should be limited to a description of the mechanisms of variation (duplication and sliding on other ducts), to a list of the most frequent variations; dangerous distributions from the surgical point of view, even if they are exceptional, must be pointed out. Interesting conclusions can be reached when there is a significant difference between a theoretical and a practical frequencies. For the surgeon, an excellent cholangiography (in three dimensions if possible) is the key of his strategy. Direct approach of the vasculo-biliary sheaths is the key of a speedy and safe surgery: in a sheath the surgeon finds only the branches supplying the parenchyma entered by this sheath.

[Surgical approach to the dorsal section of the liver]. / L'abord chirurgical du secteur dorsal du foie.

The dorsal sector of the liver is a deep and posterior territory which lies behind the hilum, close to the inferior vena cava, beneath a plane passing by the terminal portion of the main hepatic veins. Two segments may be distinguished. A left one, segment I, the prominent part of which is the caudate lobe, is united anteriorly with segment IV and lies to the left of the vena cava. A right one, segment IX, is posterior to the right portal pedicle, anterior to the vena cava (at times also to the right), beneath the terminal portion of the right superior and the middle hepatic veins. This dorsal sector is supplied by numerous small ascending portal branches of 1st, IInd and IIIrd order, and efferent veins enter directly the caval stem. The sector lies in the posterior surface of the liver, covered by the mass of the organ and the lesser omentum, fixed posteriorly by the coronary ligament and the entrance of the hepatic veins into the vena cava. However there is always a loose connective tissue between the liver and the vein. Three manoeuvres give access to this dorsal territory: 1. Posterior detachment of the liver by division of the lesser omentum, the falciform and coronary ligaments; the vena cava is then well exposed.(ABSTRACT TRUNCATED AT 250 WORDS)

Portal bifurcation and main portal fissure

Varias caracteristicas da anatomia hepatica foram investigadas em relacao a tres posicoes da fissura portal principal: a direita da bifurcacao portal, atraves dela ou a sua esquerda. Quando a fissura corta a veia portal direita, o lobo hepatico direito e menor ( atualmente conhecido como setor lateral direito menor), com distribuicao venosa normal em 82,5 por cento, a confluencia biliar superior esta usualmente posicionada a frente da veia portal direita ou da bifurcacao portal (86,1 por cento), um tronco das veias hepaticas media e esquerda e muito frequente (94,5 por cento), mas usualmente duas veias drenam o lobo esquerdo (40,6 por cento)....

[Bisection of the liver for transplantation. Simplification of the method]. / Bipartage réglé du foie en vue de transplantation. Simplification de la méthode.

Blind bipartition of a whole liver to obtain two transplants is problematic, because of frequent vasculo-biliary duplications, especially arterial (mainly on the left) and biliary (mainly on the right) duplications. Arteriography and cholangiography on the back table are necessary to obtain a map of the arterial and biliary distributions without injuring the vessels of the biliary ducts enclosed in the vasculo-biliary sheaths. The surgeon may use three special maneuvers: resection of segment IV when the arterio-biliary duplication involves segment IV; attribution of the common hepatic artery on the side of the arterial duplication (frequent on the left); attribution of a short segment of the common hepatic duct on the side of a biliary duplication (frequent on the right). In an anatomical study of 93 vasculo-biliary casts, the following results were obtained: in 4 cases: bipartition not possible; in 22 cases: "ideal" bipartition (no duplication); in 57 cases: partition right-left livers: in 37 cases 1 maneuver, in 19 cases 2 maneuvers, in 1 case 3 maneuvers; in 10 cases: partition right liver-left lobe: in 2 cases 1 maneuver, in 8 cases 2 maneuvers. We report 8 bipartitions and 16 transplantations (10 children and 6 adults). The duplications we noted do not differ statistically from those reported in our former anatomical study. Survival of the patients (100% in usual cases, 66% in case of extreme emergency or terminal hepatic insufficiency) and survival of the transplants (68,75%) do not differ either from those noted in other transplantation methods. Complications, especially arterial thrombosis, were within the same statistical ranges.(ABSTRACT TRUNCATED AT 250 WORDS)