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Postliver Transplantation Vascular and Biliary Surgical Anatomy
Postliver Transplantation Vascular and Biliary Surgical Anatomy Wael E.A. Saad, MBBCh,* Mark C. Orloff, MD,† Mark G. Davies, MD, PhD,‡ David L. Waldman, MD, PhD,§ and Adel Bozorgzadeh, MD¶ Imaging and management of postliver transplantation complications require an understanding of the surgical anatomy of liver transplantation. There are several methods of liver transplantation. Furthermore, liver transplantation is a complex surgery with numerous variables in its 4 anastomoses: (1) arterial anastomosis, (2) venous inflow (portal venous) anastomosis, (3) venous outflow (hepatic vein, inferior vena cava, or both) anastomosis, and (4) biliary/biliary-enteric anastomosis. The aim of this chapter is to introduce the principles of liver transplant surgical anatomy based on anastomotic anatomy. With radiologists as the target readers, the chapter focuses on the inflow and outflow connections and does not detail intricate surgical techniques or intraoperative maneuvers, operative stages, or vascular shunting. Tech Vasc Interventional Rad 10:172-190 © 2007 Elsevier Inc. All rights reserved. Keywords surgical anatomy, liver, transplanatation, anastomosis, graft
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ne must be cognizant of the postoperative surgical anatomy of liver transplantation to discuss (1) the incidence and types, (2) the diagnostic imaging modalities, (3) planning for minimal invasive management, as well as (4) comparing the results of therapeutic modalities of complications of liver transplantation. After all, the majority of postoperative complications of liver transplantation are usually related to the surgery and not a primary anatomical or pathological problem within the liver. There are several methods of liver transplantation. In addition, each type of liver transplantation is a large and complex surgery with the following numerous connections: (1) arterial connections, (2) venous inflow (portal venous) connections, (3) venous outflow (hepatic vein and/or inferior vena cava) connections, and (4) biliary/ biliary-enteric connections. Methods or types of liver transplants are summarized in Table 1.1-5 Moreover, there
*Vascular Interventional Radiology Section, Department of Imaging Sciences, University of Rochester Medical Center, Rochester, NY. †Division of Solid Organ Transplantation, Department of Surgery, University of Rochester Medical Center, Rochester, NY. ‡Division of Vascular Surgery, Department of Surgery, University of Rochester Medical Center, Rochester, NY. §Vascular Interventional Radiology Section, Department of Imaging Sciences, University of Rochester Medical Center, Rochester, NY. ¶Division of Solid Organ Transplantation, Department of Surgery, University of Rochester Medical Center, Rochester, NY. Address reprint requests to Wael E.A. Saad, MBBCh, Vascular Interventional Radiology Section, Department of Imaging Sciences, University of Rochester Medical Center, 601 Elmwood Ave, Box 648, Rochester, NY 14618. E-mail: [email protected].
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are numerous variations with cross variables to the type of transplant and to the type of connection. One subset, albeit less common, of liver transplantation that is not included in Table 1 is the auxiliary liver transplantation. Unlike the remaining subsets of liver transplantation, the native liver is not completely removed (no complete recipient hepatectomy). The graft (whole or reduced) is placed as an extra organ while leaving the native liver in situ.3 There are two variants of auxiliary liver transplants: first, is the nonanatomical (heterotopic) auxiliary liver transplant (HALT); and second, the anatomical auxiliary liver transplant, where part of the native liver is resected and replaced by the concomitant part of the graft (APOLT: auxiliary partial orthotopic liver transplantation).3 Due to the high degree of variation in surgical anatomy, it is difficult to create an entire atlas of liver transplant surgical anatomy, particularly in the limited scope of this chapter. The aim of this chapter is to introduce the principles of liver transplant surgical anatomy with the basic variables of surgical (arterial, venous, and biliary-enteric) anastomoses.
Arterial Surgical Anatomy Transplant hepatic arterial definitions. Since these are surgical anastomoses and complications, the posttransplant hepatic artery should be defined and classified relative to the surgical anastomosis6-8 (Fig. 1). As can be seen in Figure 1, the arterial supply can be classified into the recipient (proximal or native artery) and the graft (distal or donor artery). These two sides meet at the surgical anas-
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Table 1 Types of Orthotopic Liver Transplantations
Full (whole) graft
*Split right lobe graft
*Split left lobe graft
Cadaveric Donor
Living Related Donor
Adult recipients Most common adult transplant in the USA Resorted to in graft shortages Small adult recipients
Not compatible with life of the donor (not performed)
Pediatric recipients
Adult recipients Most common adult transplant outside the USA Pediatric recipients
Auxiliary orthotopic liver transplants are not included in the table. *Split graft transplants are also referred to as “reduced liver transplantation.” Living related liver transplants, whether left lobe or right lobe, are considered a type of split/reduced liver transplantation.
Figure 1 Arterial anastomosis. (A) Line drawing demonstrating the common end-to-end hepatic arterial anastomosis. There is a single anastomosis. Distal to the anastomosis is the graft or donor artery (not shaded). Proximal to the anastomosis is the recipient or native arterial vasculature (shaded gray). (B) Line drawing demonstrating an infrarenal aortohepatic conduit. In this case, the conduit is formed of 2 pieces and thus the entire arterial connection has 3 anastomoses (from proximal to distal): (1) aortoconduit junction anteriorly, (2) intraconduit, and (3) conduit to graft hepatic artery junction. The number of anastomoses is always 1 more than the number of segments or pieces that make the conduit (see Fig. 2B). Conduits can be made of synthetic material such as Gortex (e-PTFE) or autologous vein or iliac arteries. The native arterial vasculature is shaded gray. (C) A focused line drawing of Figure 1A demonstrating the common end-to-end hepatic arterial anastomosis. There is a single anastomosis. Proximal to the anastomosis is the native or recipient (N/R) arterial vasculature (shaded gray). Distal to the anastomosis is the graft or donor (G/D) artery (not shaded). The graft arterial vasculature can be divided into extrahepatic (a) or intrahepatic (branch arteries; b). LGA, left gastric artery (native); SpA, splenic artery (native).
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174 Table 2 Basic Surgical Connections (Anstomoses) of the Transplant Hepatic Artery Type of Anastomosis
Native or Recipient Artery
Graft or Donor Artery
Number of Anastomoses
End-to-end hepatic anastomosis
Common or proper hepatic artery
Common or proper hepatic artery (right or left hepatic artery in split grafts including living related transplants)
One
Aortohepatic interposition conduit
Abdominal aorta (usually infraaortic)
Common or proper hepatic artery (right or left hepatic artery in split grafts including living related transplants)
Two or more (can be 4 or more) Conduit can be arterial > venous > synthetic
Splenohepatic anastomosis
Splenic artery
Common or proper hepatic artery (right or left hepatic artery in split grafts including living related transplants)
One
GDA-hepatic anastomosis
Gastroduodenal artery (GDA)
Common or proper hepatic artery (right or left hepatic artery in split grafts including living related transplants)
One
ILLUSTRATION
Postliver transplantation surgical anatomy
Figure 2 Aortohepatic conduits. (A) Line drawing demonstrating a suprarenal aortohepatic conduit. This is not a common conduit. SpA, splenic artery; CAx, celiac axis (celiac trunk); GDA, gastroduodenal artery; SMA, superior mesenteric artery; RRA, right renal artery; LRA, left renal artery. (B) Line drawing demonstrating an infrarenal aortohepatic conduit. In this case, the conduit is formed of 1 piece and thus the entire arterial connection has 2 anastomoses (between arrows): (1) aortoconduit junction anteriorly, and (2) conduit to graft hepatic artery junction. The number of anastomoses is always 1 more than the number of segments or pieces that make the conduit (see Fig. 1B). (C) This is a digitally subtracted angiogram (DSA) in an adult liver transplant recipient of an infrarenal aortohepatic conduit. The DSA is performed using a 5-Fr C-2 cobra catheter with its tip just distal to the proximal anastomosis of the conduit. The arrows indicate the 2 anastomoses of the conduit: one set of arrows at the aortoconduit junction, and the other set of arrows at the conduit to graft hepatic artery junction. The dotted outline shows the depicted borders of the proximal conduit.
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tomosis (Fig. 1A and C) or a series of anastomoses if there is an interposition conduit/vascular graft (Fig. 1B). The distal, graft, or donor artery(s) can be divided into (1) intrahepatic graft (branch arteries) arteries, and (2) extrahepatic graft arteries6-8 (Fig. 1C). Surgical connections. Various surgical arterial anastomoses have been described.1,5,9-16 The more common are illustrated in Table 2.1,5,9-16 Arterial surgical anatomy and connections can be broadly classified into (1) aortohepatic conduits (Fig. 2, Fig. 3), (2) end-to-end hepatic arterial anastomoses (Fig. 1A and C), and (3) viscerohepatic arterial communications with or without conduits (Fig. 4C). The latter type includes native spleno- to graft hepatic arterial anastomoses and anastomoses between the native gastroduodenal artery and the graft hepatic artery1,5,9-17 (Table 2). Direct aortohepatic conduits can be either supraceliac aortohepatic conduits (not common) (Fig. 2A) or infrarenal aortohepatic conduits (most common) 5 (Fig. 2B, C, Fig. 3). Infrarenal aortohepatic conduits are passed through the transverse mesocolon and can be behind the stomach and anterior to the pancreas (Fig. 3A), or behind both the stomach and the pancreas5 (Fig. 3B). Even with apparently the simplest types of surgical arterial communications, the arterial anastomosis may not be primary or singular, but may be via an interposition vascular graft (Fig. 4). Interposition grafts between visceral arteries are resorted to when (1) the arterial stumps of either native and/or graft are too short to be approximated for a primary anastomosis, (2) the arterial connection is being revised (revascularization) or occasionally in cases of retransplantation, and (3) revascularization with an extra-anatomic bypass in case of porta hepatis infection (eg, bile leak, arteritis/mycotic pseudoaneurysm, or subhepatic collections).1,5,9-16,18 Interposition vascular grafts include autologous arterial or venous grafts or expandedpolytetrafluoroethylene (e-PTFE) synthetic conduits. Most aortohepatic conduits originate from the infrarenal aorta and when created by autologous material (vein or artery) may be composed of several segments and thus may have more than two anastomoses. A single segment conduit of any sort has at least two anastomoses. Regarding conduits, the number of anastomoses is one more than the number of segments used in the conduit (Fig. 1B, Fig. 2B). It should be noted that studies that have more cases of conduits (whether aortohepatic conduits or viscerohepatic conduits) increase the incidence of anastomotic arterial complications such as hepatic artery stenoses (HAS). This is because they increase the chance of HAS occurring at the anastomosis by merely having at least double the number of anastomoses compared with primary end-to-end hepatic artery to hepatic artery anastomosis7,19 (Fig. 1). As mentioned in the introduction to the chapter, there are numerous variables due to several dimensions of variations. One of these dimensions is differences in anatomy of the recipient and the donor. Figure 5 shows how two different anatomic variations of the donors can be connected arterially, as a whole liver graft, to a recipient with a classic arterial distribution. The line drawings in Figure 5 are not how the arterial connections should be per-
Figure 3 Infrarenal aortohepatic conduits. (A) Line drawing demonstrating an infrarenal aortohepatic conduit (C) passing retroperitoneally anterior to the pancreas and posterior to the stomach. Ao, abdominal aorta; C, conduit (aortohepatic conduit); CAx, celiac axis (celiac trunk); PHA, proper hepatic artery; P, pancreas; D, duodenum. (B) Line drawing demonstrating an infrarenal aortohepatic conduit (C) passing retroperitoneally posterior to both the pancreas and the stomach. Ao, abdominal aorta; C, conduit (aortohepatic conduit); CAx, celiac axis (celiac trunk); PHA, proper hepatic artery; P, pancreas; D, duodenum.
formed; however, they are just suggestions that help the reader appreciate the numerous possibilities that may be encountered in the arterial surgical anatomy of liver transplantation. The second and less common example (Fig. 5) shows that arterial connections of a liver transplant can have more than one anastomosis without having an interposition vascular graft (conduit) (Fig. 5).
Postliver transplantation surgical anatomy
Figure 4 Viscerohepatic interposition conduits. (A) Sagittally oriented maxium intensity projection (MIP) image from a computer tomographic angiography (CTA) of an adult liver transplant recipient with an interposition graft (conduit) extending from the recipient hepatic artery to the graft hepatic artery (GHA). The interposition graft (conduit) spans between the 2 arrows. Ao, abdominal aorta; CAx, celiac axis (celiac trunk); SMA, superior mesenteric artery; GHA, graft hepatic artery. (B) This is a digitally subtracted angiogram (DSA) in the same adult liver transplant recipient as Figure 4A. The DSA is performed using a microcatheter placed coaxially through a 5-Fr SOS catheter in a frontal projection. The tip of the 5-Fr SOS catheter is in the celiac trunk. The straight segment of the microcatheter represents the interposition graft/conduit (span between arrows). The small arrowheads point to an intrahepatic arterial narrowing possibly as the result of compression from the adjacent pseudoaneurysm (single arrowhead). (C) Line drawing depicting the interposition graft in Figure 4A and B. The graft spans between the 2 anastomoses. Ao, abdominal aorta; CAx, celiac axis (celiac trunk); SMA, superior mesenteric artery; SpA, splenic artery; GDA, gastroduodenal artery; RRA, right renal artery; LRA, left renal artery.
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Figure 5 Recipient-donor arterial preparation and anastomosis. Line drawings demonstrating how two different anatomic variations of the donors and how they can be connected arterially to a recipient with a classic arterial distribution. The line drawings in Figure 5 are not how the arterial connections should be performed; however, they are suggestions that help the reader appreciate the numerous possibilities that may be encountered in the arterial surgical anatomy of liver transplantation. The top row (figure part: X) is a single recipient with invariable anatomy. The bottom row (figure parts: Y and Z) is 2 recipients with different hepatic arterial anatomy: one with a classic arterial distribution (figure part: Y) just like the recipient (figure part: X) and the other with a replaced right hepatic artery off the SMA (figure part: Y). The middle row is the resultant posttransplant arterial surgical anatomy; either XY (combination of recipient X and donor Y) or XZ (combination of recipient X and donor Z). The harvested donor arterial vasculature is shaded gray. Figure parts: XY (combination of recipient X and donor Y): On the left-hand side, the visceral arterial branches of the donor are standard without deviation in variants. The entire celiac axis with its major branches is harvested from the donor and the donor celiac axis is sutured to the recipient common hepatic artery at the branch point of the common hepatic artery and the gastroduodenal artery. Figure parts: XZ (combination of recipient X and donor Z): On the right-hand side, the donor has a replaced right hepatic artery (RRHA) off the superior mesenteric artery (SMA). The left hepatic artery is off the proper hepatic artery of the recipient. The RRHA with its donor SMA segment is harvested along with the left donor hepatic artery (LHA). The ostium of the donor SMA is sutured to the recipient common hepatic artery at the branch point of the common hepatic artery and the gastroduodenal artery. The donor left hepatic artery is sutured to the continuum of the donor SMA segment. OLT, orthotopic liver transplant; CAx, celiac axis (celiac trunk); SMA, superior mesenteric artery; SpA, splenic artery; GDA, gastroduodenal artery; PHA, proper hepatic artery; RRHA, replaced right hepatic artery; LHA, left hepatic artery.
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Figure 6 Anatomical variants of the tributaries of the main portal vein. Illustrations demonstrating the more common variant mesenteric vein confluences that form the main portal vein and their incidences. SpV, splenic vein; IMV, inferior mesenteric vein; SMV, superior mesenteric vein.
Venous Surgical Anatomy Venous surgical anatomy postliver transplantation can be divided into portal venous (inflow vein) anatomy and hepatic venous outflow anatomy. Portal venous surgical anatomy. Portal venous surgical anatomy is usually not as complex (less variables) as what the arterial and biliary surgical anatomy can be. One of the portal venous anatomy variables is the mesenteric venous variants of the recipient (Fig. 6). When the portal vein of the recipient is too small, the recipient portal vein is dissected beyond its bifurcation.4 The “crutch” of the bifurcation is opened longitudinally (perpendicular to the long axis of the main portal vein) to widen the recipient portal vein to match the larger donor/graft portal vein4 (Fig. 7).
This branch-patch angioplasty technique can be applied to any viscera/vessel (arterial, venous, or even biliary) at a branch point of the lesser caliber vessel (see outflow venous surgical anatomy, Fig. 10).4-5 When the recipient or graft portal vein(s) fall short of one another, an interposition graft can be used to bridge the recipient and graft portal vein4 (Fig. 8B). Reasons for having short portal vein stumps include: poor surgical techniques including donor harvest, or excision of damaged vein segments from intraoperative iatrogenic injury, iatrogenic injury from deeply placed endothelialized transjugular intrahepatic portosystemic shunt (TIPS) stents, or segmental chronically thrombosed and organized portal vein. If the portal vein segment extends to and possibly involves the mesenteric vein tributaries of the portal vein, complex venous reconstructions may be required with a long segment of interposition graft4,20 (Fig. 8C). Outflow venous surgical anatomy. Outflow veins include the hepatic vein(s) and the inferior vena cava. Figure 9 gives the sagittal schematic of four different types of venous connections2,4,5,21,22 (Fig. 9A-D). The first three (Fig. 9A-C) are for full grafts and the last two venous connections (Fig. 9D, E) depict reduced grafts/living related grafts. Figure 10 details the sagittal and frontal schematic of preparing a recipient for a “piggyback” venous anastomosis.5,21 Figure 11 details the sagittal schematic of preparing a donor and a recipient for a piggyback venous anastomosis.5,21 The details of reduced or split graft venous outflow connections are depicted in Figure 12.2,4 The outflow veins of a split graft are either (1) connected directly in an end-to-end manner with the recipient veins (Figs. 9E, 12A) or (2) connected directly to the inferior vena cava (IVC) in a patch venoplasty manner2,4 (Figs. 9D, 12B).
Biliary Surgical Anatomy Figure 7 Preparation of a relatively small recipient portal vein. Line drawing demonstrating how a smaller caliber recipient portal vein (RPV) can be branch-patched by dissecting it at its bifurcation (perpendicular to its long axis) so that the diameter discrepancy between the donor portal vain (DPV) and the recipient portal vein (RPV) is reduced.
Biliary-enteric anastomoses. Usually biliary-enteric anastomoses are performed by performing an end-to-side hepaticojejunostomy (Fig. 13, Fig. 14); the end being the end of the common hepatic duct of the graft with the side of a jejunal loop.22 The jejunal loop is more commonly brought up to the hepatic hilum of the graft in a Roux-en-Y manner22 (Fig. 15). Less commonly, the jejunal loop is an interposition jejunal loop22-24 (Fig. 16). The length of the stump of the extrahe-
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Figure 8 Methods to approximate the recipient and donor portal veins. (A) Illustration demonstrating a primary end-to-end portal vein anastomosis between the graft portal vein (PV) and the recipient portal vein (PV). SpV, splenic vein; MV, mesenteric vein(s). (B) Illustration demonstrating an interposition graft bridging the graft portal vein (PV) and the recipient portal vein (PV). The recipient PV is short and its lack of length is compensated by the interposition graft. SpV, splenic vein; MV, mesenteric vein(s); LPV, left portal vein (of graft); RPV, right portal vein (of graft). (C) Illustration demonstrating a graft longer than the one in Figure 8B and extending to and involving the confluence of the splenic vein (SpV) and the mesenteric vein(s) (MV).
Postliver transplantation surgical anatomy
Figure 9 Types of venous outflow and caval anastomosis. Line drawings demonstrating the different outflow vein (hepatic veins or inferior vena cava) connections are oriented between recipient and donor/graft. The outflow veins are sagittally oriented. The first 3 (A-C) are for full/whole grafts and the last 2 venous connections (D and E) depict reduced grafts/living related grafts. RA, right atrium; IVC, inferior vena cava; HV, hepatic vein(s); shaded, donor vessels; not shaded, recipient vessels. (A) This is an intercaval venous outflow connection. In this setting there are 2 anstomoses connecting the donor caval segment. (B) This is a “piggyback” vena caval outflow connection. In this setting there is one anastomosis at the single graft-recipient caval junction. (C) This is a cavoplasty outflow connection, where the graft inferior vena cava (IVC) is patched directly onto an incised recipient IVC. In this setting there is 1 anastomosis circumferentially around the single graft-recipient caval junction. (D) This is a venoplasty outflow connection, where the graft outflow vein pedicle or pedicles are patched directly onto an incised recipient IVC. In this setting there is 1 anastomosis circumferentially around the single graft-recipient venocaval junction. (E) This is 2 end-to-end hepatic vein–to– hepatic vein anstomoses between the outflow graft hepatic vein and their equivalent veins on the recipient side. Combinations of D and E can be performed, where one graft outflow vein is connected to the recipient IVC with a patch venoplasty and the other graft outflow vein is connected to a recipient hepatic vein in an end-to-end manner.
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Figure 10 Preparation of the recipient hepatic vein stump for a “piggyback” caval anastomosis. This is a line drawing demonstrating the preparation of the recipient for a caval piggyback anastomosis. The left-sided images are the sagittal projection and on the right sided images are the frontal projections. The dotted arrow lines signify the line at which the hepatic veins are cut to create one hepatic vein stump (HVS) that can accommodate the caliber of the graft inferior vena cava without to much diameter discrepancy.
patic graft bile duct can vary. The shorter this stump, the closer the jejunal loop is to the graft hilum (hilar plate) (Fig. 17). As the biliary stump gets even shorter and extends into the hilar plate, the recipient can get somewhat of a 3-way single biliary enteric anastomosis with the 2 main intrahepatic graft bile ducts meeting at the single biliary-enteric anastomosis (Fig. 17C). This single anastomosis with the confluence of the 2 main graft bile ducts nearby (Fig. 18) may
falsely appear by cholangiography as a graft with 2 independent biliary enteric anastomoses (ie, Fig. 17B or C look, by cholangiography, like Fig. 17D). This appearance occurs, particularly, when there is superadded stenotic disease at the anastomosis and at the site of the main duct confluences (Fig. 18B). The stenotic disease may be due to perianastomotic scarring or fibrosis, which may be exacerbated by local ischemia (microvascular injury from dissecting around the bile ducts during transplantation and violating the peribiliary vascular plexus) or global graft ischemia (hepatic artery thrombosis) or stenosis.25-27 Furthermore, if the second biliary radical is not appreciated by cholangiography, operators, knowing that there is a single anastomosis, may overlook an isolated segment. Oblique images and watching for hepatic segment void of biliary radicals by cholangiography may help appreciate the isolated biliary segment. Compared with native livers, this may be more difficult in liver transplant recipients with reduced grafts that have hypertrophied and rotated. In these cases careful examination of contrast-enhanced computed tomographic (CT) examinations of the liver may delineate this isolated segment. Biliary-to-biliary anastomoses. Biliary-to-biliary anastomoses can be hepatico-choledochostomies (Fig. 19A, Fig. 20) or choledocho-choledochostomies (Fig. 19B, C, Fig. 21). It should be noted that diameter discrepancies can be seen in biliary-to-biliary anastomoses even in cases of adult-to-adult whole graft choledocho-choledochostomies (Fig. 19C, Fig. 22). When a significant diameter discrepancy is noted it is more commonly a wider recipient common bile duct compared with the donor bile duct; and this is usually due to a larger age difference between recipient [older with wider common bile duct (CBD)] and donor (younger with narrower bile duct). Biliary-to-biliary anastomoses are not necessarily exclusive to whole (cadaveric) grafts, but can also be seen in reduced grafts, particularly living related transplants26,27 (Fig. 20). Obviously, biliary enteric anastomoses are not uncommon in reduced including living related transplants26,27 (Fig. 20, Fig. 23, Fig. 24).
Figure 11 Preparation of the recipient hepatic vein stump and donor inferior vena cava for a “piggyback” caval anastomosis. This is a line drawing demonstrating the preparation of both the recipient and the donor for a caval “piggyback” anastomosis. The left-sided images are the sagittal projections of the recipient (not shaded). The rightsided images are the sagittal projections of the donor (shaded). The center image is the final product (the recipient after the transplantation). HVS, hepatic vein stump; IVC, inferior vena cava; RA, right atrium.
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Figure 12 Types of venous outflow anastomoses in split grafts. These are illustrations demonstrating two different venous anastomoses for split/reduced grafts. These illustrations are the equivalent of the line drawings of Figure 9D and E. RHV, recipient hepatic veins; DHV, donor hepatic veins; RHL, right hepatic lobe graft; LHL, left hepatic lobe graft; J, jejunum; PV, portal vein; Ao, aorta. (A) (Equivalent to line drawing in Figure 9D.) This is a left hepatic lobe reduced graft. This is the split graft that is usually resorted to in infants and children. In this illustration the left lobe transplant is depicted to be connected to the recipient inferior vena cava by a patch venoplasty. (B) (Equivalent to line drawing in Figure 9E.) This is a right hepatic lobe reduced graft. This is the split graft that is usually resorted to in large children or in living related liver transplant adult recipients. In this illustration the right lobe transplant is depicted to be venously connected by one-on-one end-to-end hepatic vein anastomoses. The outflow veins of the graft are not directly anastomosed to the recipient vena cava.
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Figure 13 End-to-side biliary-enteric anastomosis. This is a line drawing demonstrating end-to-side hepaticojejunostomy, where the end of the common hepatic duct (CHD) of the graft is connected to the side of a jejunal loop (J). RHDs, right hepatic ducts; LHDs, left hepatic ducts. Figure 15 Roux-en-Y jejunal loop. This is a line drawing demonstrating end-to-side hepaticojejunostomy, connected to a Roux-en-Y jejunal loop (Roux J). The Roux-en-Y loop is connected end-to-side to the remainder of the small bowel (in situ J).
Figure 14 End-to-side biliary-enteric anastomosis. This is a transhepatic cholangiogram in a whole graft with a hepaticojejunal anastomosis (between arrows). The dashed black and white outline depicts the outline of the jejunal loop (J).
Figure 16 Interposition jejunal loop. This is a line drawing demonstrating end-to-side hepaticojejunostomy, connected to an interposition jejunal loop (J). The interposition jejunal loop is connected end-to-side to the duodenum. P, pancreas.
Postliver transplantation surgical anatomy
Figure 17 Appearance of biliary-enteric anastomoses in whole grafts. Line drawings demonstrating biliary-enteric anastomoses with varying length extrahepatic bile ducts, from a moderate length graft common hepatic duct with a single hepaticojejunal anastomosis (A), to a short graft common hepatic duct with a single hepaticojejunal anastomosis (B), to a wide hepaticojejunal anastomosis at the confluence of the main right and left hepatic duct (C). In addition, a fourth biliary-enteric line drawing demonstrates no graft common hepatic duct. The main right and left hepatic duct are connected independently to the jejunum (J) (D). J, jejunum; RHDs, right intrahepatic ducts; LHD, left hepatic duct.
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Figure 18 Appearance of biliary-enteric anastomoses with superadded stenotic disease. This is a line drawing demonstrating a wide hepaticojejunal anastomosis at the confluence of the main right and left hepatic duct. (A) This is a line drawing showing the anastomosis without superadded disease. (B, C) This is a line drawing showing the anastomosis with superadded stenotic disease. B shows the superadded disease as shaded areas around the confluence of the central bile ducts of the graft. C shows the superadded disease outline; and shows how this “wide-mouth” single anastomosis can be seen by cholangiography as 2 separate anastomoses. RHDs, right intrahepatic ducts; LHD, left hepatic duct.
Figure 19 Appearance of bile-to-bile anastomoses in whole grafts. These are line drawings demonstrating bile-to-bile anastomoses with varying length extrahepatic bile ducts of the graft. RHDs, right intrahepatic ducts; LHD, left hepatic duct; R-CBD, recipient common bile duct. (A) This is a hepatico-choledochostomy with a relatively short extrahepatic graft bile duct (common hepatic bile duct of the graft). (B) This is a choledocho-choledochostomy with a relatively longer extrahepatic graft bile duct (common bile duct of the graft). (C) This is a choledocho-choledochostomy with a diameter discrepancy between the wider recipient common bile duct (R-CBD) and the narrower graft bile duct. This is most likely due to a wide age difference between an older recipient and a younger cadaveric donor.
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Figure 20 Bile-to-bile anastomoses in split right hepatic lobe graft. (A) This is a line drawing showing a hepatico-choledochostomy between a main right hepatic bile duct of a right hepatic lobe graft and the recipient common bile duct (R-CBD). RHDs, right intrahepatic ducts. (B) This is a cholangiogram consistent with the line drawing in A showing a hepatico-choledochostomy between a main right hepatic bile duct of a right hepatic lobe graft and the recipient common bile duct (R-CBD). The arrowheads depict the level of the anastomosis.
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Figure 21 Choledocho-choledochostomy anastomosis in whole grafts. (A) This is a line drawing showing a choledocho-choledochostomy between the common bile duct of the graft and the recipient common bile duct. D, duodenum. (B) This is a cholangiogram consistent with the line drawing in A showing a choledocho-choledochostomy between the common bile duct of the graft and the recipient common bile duct. The arrows depict the level of the anastomosis.
Figure 22 Choledocho-choledochostomy anastomosis in whole grafts with diameter discrepancy. This is a percutaneous transhepatic cholangiogram (PTC) consistent with the line drawing in Figure 19C showing a choledocho-choledochostomy between the common bile duct of the graft and the recipient common bile duct (R-CBD) with a diameter discrepancy between the older and wider R-CBD and the narrower and younger graft CBD. The arrows depict the level of the anastomosis.
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Figure 23 Biliary-enteric anastomoses in split right-hepatic lobe graft. These are illustrations and images representing a right hepatic lobe split graft (G-RHL) (possibly a right hepatic lobe living related transplant) with a hepaticojejunal anastomosis (HJ). (A) This is an illustration representing a right hepatic lobe split graft (G-RHL) (possibly a right hepatic lobe living related transplant) with a hepaticojejunal anastomosis (H-J). G-RHL, right hepatic lobe graft; RHDs, right intrahepatic ducts; H-J, hepaticojejunal anastomosis; PV, portal vein; J, jejunal loop; Ao, aorta; IVC, inferior vena cava. (B) This is a cholangiogram of a living related adult right hepatic lobe recipient with a hepaticojejunal anastomosis (between arrows). J, jejunal. (C) This is a line drawing representing a right hepatic lobe split graft with a right hepaticojejunal anastomosis. RHDs, right intrahepatic ducts; J, jejunal loop.
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Figure 24 Biliary-enteric anastomoses in split left hepatic lobe graft. (A) This is an illustration representing a left hepatic lobe split graft (G-LHL) (possibly a left hepatic lobe living related transplant) with a hepaticojejunal anastomosis (H-J). G-lHL, left hepatic lobe graft; LHDs, left intrahepatic ducts; H-J, hepaticojejunal anastomosis; J, jejunal loop. (B) This is a cholangiogram of a split cadaveric left hepatic lobe pediatric recipient (now a teenager) with a strictured left hepaticojejunal anastomosis (between arrows). J, jejunal.
References 1. Blumgart LH (ed): Surgery of the Liver, Biliary Tract, and Pancreas. 4th ed. Philadelphia, PA, Saunders, 2006 2. Lang H, Malago M, Broelsch CE: Liver transplantation in children and segmental transplantation, in Blumgart LH (ed): Surgery of the Liver, Biliary Tract, and Pancreas. 4th ed. Philadelphia, PA, Saunders, 2006 3. Terpstra OT: Auxiliary liver transplantation, in Blumgart LH (ed): Surgery of the Liver, Biliary Tract, and Pancreas. 4th ed. Philadelphia, PA, Saunders, 2006
W.E.A. Saad et al. 4. Strong RW and Lynch SV: Live related donors in liver transplantation, in Blumgart LH (ed): Surgery of the Liver, Biliary Tract, and Pancreas. 4th ed. Philadelphia, PA, Saunders, 2006 5. Casavilla A, Gordon RD, Starzl TE: Techniques of liver transplantation, in Blumgart LH (ed): Surgery of the Liver, Biliary Tract, and Pancreas. 4th ed. Philadelphia, PA, Saunders, 2006 6. Orons PD, Zajko AB, Bron KM, et al: Hepatic artery angioplasty after liver transplantation: experience in 21 allografts. J Vasc Interv Radiol 6:523-529, 1995 7. Saad WEA, Davies MG, Sahler LG, et al: Hepatic artery stenosis in liver transplant recipients: primary treatment with percutaneous transluminal angioplasty. J Vasc Interv Radiol 16:795-805, 2005 8. Abassoglu O, Levy MF, Vodapally MS, et al: Hepatic artery stenosis after liver transplantation—incidence, presentation, treatment and long term outcome. Transplantation 63:250-255, 1997 9. Farmer DG, Amersi F, Busuttil RW: Orthotopic liver transplantation, in Blumgart LH (ed): Surgery of the Liver, Biliary Tract, and Pancreas. 4th ed. Philadelphia, PA, Saunders, 2006 10. Quinones-Baldrich WJ, Memsic L, Ramming K, et al: Branch patch for arterialization of hepatic grafts. Surg Gynecol Obstet 162:489-490, 1986 11. Di Benedetto F, Lauro A, Masetti M, et al: Outcome in right living related liver transplantation with branch-patch arterial reconstruction. World J Surg 29:1667-1669, 2005 12. Mizuno S, Yokoi H, Shuji I, et al: Using a radial artery as an interpositional vascular graft in a living-donor liver transplantation for hepatocellular carcinoma. Transpl Int 18:408-411, 2005 13. Del Gaudio M, Grazi G-L, Ercolani G, et al: Outcome of hepatic artery reconstruction in liver transplantation with an iliac arterial interposition graft. Clin Transpl 19:399-405, 2005 14. Yilmaz S, Kirmlioglu V, Isik B, et al: Urgent revascularization of a liver allograft with a saphenous vein interposition graft between the hepatic artery and the recipient artery after late hepatic artery thrombosis. Dig Dis Sci 50:1777-1180, 2005 15. Kasahara M, Sakamoto S, Ogawa K, et al: The use of a mesenteric artery of Roux-en-Y limb for hepatic arterial reconstruction after living-donor liver transplantation. Transplantation 80:538, 2005 16. Liu T, Dilworth P, Sosef M, et al: Arterial vascular conduits in adult orthotopic liver transplant recipients. ANZ J Surg 76:64-67, 2006 17. Ueno T, Jones G, Martin A, et al: Clinical outcomes from hepatic artery stenting in liver transplantation. Liver Transpl 12:422-427, 2006 18. Langras AN, Marujo W, Stratta RJ, et al: Vascular complications after orthotopic liver transplantation. Am J Surg 161:76-83, 1991 19. Saad WEA, Waldman DL: Endovascular repair of vascular lesions in solid organ transplantation, in Ouriel K, Katzen BT, Rosenfield K (eds): Complications in Endovascular Therapy. New York, NY, Taylor and Francis Informa, 2006, pp 223-252 20. Saad WEA, Saad NEA, Davies MG, et al: Elective trans-jugular intrahepatic portosystemic shunts (TIPS) for immediate pre-transplant portal decompression in adult living related liver transplant recipient candidates: preliminary results. J Vasc Interv Radiol 17:995-1002, 2006 21. Tzakis A, Todo S, Starzl TW: Orthotopic liver transplantation with preservation of the inferior vena cava. Ann Surg 210:649-652, 1989 22. Blumgart LH, Jarnagin WR: Biliary-enteric anastomosis, in Blumgart LH (ed): Surgery of the Liver, Biliary Tract, and Pancreas. 4th ed. Philadelphia, PA, Saunders, 2006 23. Bottger T, Junginger T: A small-bowel segment as a total extrahepatic bile duct replacement. Arch Surg 127:1424-1428, 1992 24. Shamberger RC, Lund DP, Lillehei CW, et al: Interposed jejunal segment with nipple valve to prevent reflux in biliary reconstruction. J Am Coll Surg 180:10-15, 1995 25. Ramacciatto G, Varotti G, Quintini C, et al: Impact of biliary complications in right lobe living donor liver transplantation. Transpl Int 19:122-127, 2006 26. Biliary complications in adult living donor liver transplantation with duct-to-duct hepatico-choledochostomy or Roux-en-Y hepatico-jejunostomy biliary reconstruction. Surgery 132:48-56, 2002 27. Kashara M, Egawa H, Takada Y, et al: Biliary reconstruction in right lobe living-donor liver transplantation: comparison of different techniques in 321 recipients. Ann Surg 243:559-566, 2006
O
ne must be cognizant of the postoperative surgical anatomy of liver transplantation to discuss (1) the incidence and types, (2) the diagnostic imaging modalities, (3) planning for minimal invasive management, as well as (4) comparing the results of therapeutic modalities of complications of liver transplantation. After all, the majority of postoperative complications of liver transplantation are usually related to the surgery and not a primary anatomical or pathological problem within the liver. There are several methods of liver transplantation. In addition, each type of liver transplantation is a large and complex surgery with the following numerous connections: (1) arterial connections, (2) venous inflow (portal venous) connections, (3) venous outflow (hepatic vein and/or inferior vena cava) connections, and (4) biliary/ biliary-enteric connections. Methods or types of liver transplants are summarized in Table 1.1-5 Moreover, there
*Vascular Interventional Radiology Section, Department of Imaging Sciences, University of Rochester Medical Center, Rochester, NY. †Division of Solid Organ Transplantation, Department of Surgery, University of Rochester Medical Center, Rochester, NY. ‡Division of Vascular Surgery, Department of Surgery, University of Rochester Medical Center, Rochester, NY. §Vascular Interventional Radiology Section, Department of Imaging Sciences, University of Rochester Medical Center, Rochester, NY. ¶Division of Solid Organ Transplantation, Department of Surgery, University of Rochester Medical Center, Rochester, NY. Address reprint requests to Wael E.A. Saad, MBBCh, Vascular Interventional Radiology Section, Department of Imaging Sciences, University of Rochester Medical Center, 601 Elmwood Ave, Box 648, Rochester, NY 14618. E-mail: [email protected].
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are numerous variations with cross variables to the type of transplant and to the type of connection. One subset, albeit less common, of liver transplantation that is not included in Table 1 is the auxiliary liver transplantation. Unlike the remaining subsets of liver transplantation, the native liver is not completely removed (no complete recipient hepatectomy). The graft (whole or reduced) is placed as an extra organ while leaving the native liver in situ.3 There are two variants of auxiliary liver transplants: first, is the nonanatomical (heterotopic) auxiliary liver transplant (HALT); and second, the anatomical auxiliary liver transplant, where part of the native liver is resected and replaced by the concomitant part of the graft (APOLT: auxiliary partial orthotopic liver transplantation).3 Due to the high degree of variation in surgical anatomy, it is difficult to create an entire atlas of liver transplant surgical anatomy, particularly in the limited scope of this chapter. The aim of this chapter is to introduce the principles of liver transplant surgical anatomy with the basic variables of surgical (arterial, venous, and biliary-enteric) anastomoses.
Arterial Surgical Anatomy Transplant hepatic arterial definitions. Since these are surgical anastomoses and complications, the posttransplant hepatic artery should be defined and classified relative to the surgical anastomosis6-8 (Fig. 1). As can be seen in Figure 1, the arterial supply can be classified into the recipient (proximal or native artery) and the graft (distal or donor artery). These two sides meet at the surgical anas-
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Table 1 Types of Orthotopic Liver Transplantations
Full (whole) graft
*Split right lobe graft
*Split left lobe graft
Cadaveric Donor
Living Related Donor
Adult recipients Most common adult transplant in the USA Resorted to in graft shortages Small adult recipients
Not compatible with life of the donor (not performed)
Pediatric recipients
Adult recipients Most common adult transplant outside the USA Pediatric recipients
Auxiliary orthotopic liver transplants are not included in the table. *Split graft transplants are also referred to as “reduced liver transplantation.” Living related liver transplants, whether left lobe or right lobe, are considered a type of split/reduced liver transplantation.
Figure 1 Arterial anastomosis. (A) Line drawing demonstrating the common end-to-end hepatic arterial anastomosis. There is a single anastomosis. Distal to the anastomosis is the graft or donor artery (not shaded). Proximal to the anastomosis is the recipient or native arterial vasculature (shaded gray). (B) Line drawing demonstrating an infrarenal aortohepatic conduit. In this case, the conduit is formed of 2 pieces and thus the entire arterial connection has 3 anastomoses (from proximal to distal): (1) aortoconduit junction anteriorly, (2) intraconduit, and (3) conduit to graft hepatic artery junction. The number of anastomoses is always 1 more than the number of segments or pieces that make the conduit (see Fig. 2B). Conduits can be made of synthetic material such as Gortex (e-PTFE) or autologous vein or iliac arteries. The native arterial vasculature is shaded gray. (C) A focused line drawing of Figure 1A demonstrating the common end-to-end hepatic arterial anastomosis. There is a single anastomosis. Proximal to the anastomosis is the native or recipient (N/R) arterial vasculature (shaded gray). Distal to the anastomosis is the graft or donor (G/D) artery (not shaded). The graft arterial vasculature can be divided into extrahepatic (a) or intrahepatic (branch arteries; b). LGA, left gastric artery (native); SpA, splenic artery (native).
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174 Table 2 Basic Surgical Connections (Anstomoses) of the Transplant Hepatic Artery Type of Anastomosis
Native or Recipient Artery
Graft or Donor Artery
Number of Anastomoses
End-to-end hepatic anastomosis
Common or proper hepatic artery
Common or proper hepatic artery (right or left hepatic artery in split grafts including living related transplants)
One
Aortohepatic interposition conduit
Abdominal aorta (usually infraaortic)
Common or proper hepatic artery (right or left hepatic artery in split grafts including living related transplants)
Two or more (can be 4 or more) Conduit can be arterial > venous > synthetic
Splenohepatic anastomosis
Splenic artery
Common or proper hepatic artery (right or left hepatic artery in split grafts including living related transplants)
One
GDA-hepatic anastomosis
Gastroduodenal artery (GDA)
Common or proper hepatic artery (right or left hepatic artery in split grafts including living related transplants)
One
ILLUSTRATION
Postliver transplantation surgical anatomy
Figure 2 Aortohepatic conduits. (A) Line drawing demonstrating a suprarenal aortohepatic conduit. This is not a common conduit. SpA, splenic artery; CAx, celiac axis (celiac trunk); GDA, gastroduodenal artery; SMA, superior mesenteric artery; RRA, right renal artery; LRA, left renal artery. (B) Line drawing demonstrating an infrarenal aortohepatic conduit. In this case, the conduit is formed of 1 piece and thus the entire arterial connection has 2 anastomoses (between arrows): (1) aortoconduit junction anteriorly, and (2) conduit to graft hepatic artery junction. The number of anastomoses is always 1 more than the number of segments or pieces that make the conduit (see Fig. 1B). (C) This is a digitally subtracted angiogram (DSA) in an adult liver transplant recipient of an infrarenal aortohepatic conduit. The DSA is performed using a 5-Fr C-2 cobra catheter with its tip just distal to the proximal anastomosis of the conduit. The arrows indicate the 2 anastomoses of the conduit: one set of arrows at the aortoconduit junction, and the other set of arrows at the conduit to graft hepatic artery junction. The dotted outline shows the depicted borders of the proximal conduit.
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tomosis (Fig. 1A and C) or a series of anastomoses if there is an interposition conduit/vascular graft (Fig. 1B). The distal, graft, or donor artery(s) can be divided into (1) intrahepatic graft (branch arteries) arteries, and (2) extrahepatic graft arteries6-8 (Fig. 1C). Surgical connections. Various surgical arterial anastomoses have been described.1,5,9-16 The more common are illustrated in Table 2.1,5,9-16 Arterial surgical anatomy and connections can be broadly classified into (1) aortohepatic conduits (Fig. 2, Fig. 3), (2) end-to-end hepatic arterial anastomoses (Fig. 1A and C), and (3) viscerohepatic arterial communications with or without conduits (Fig. 4C). The latter type includes native spleno- to graft hepatic arterial anastomoses and anastomoses between the native gastroduodenal artery and the graft hepatic artery1,5,9-17 (Table 2). Direct aortohepatic conduits can be either supraceliac aortohepatic conduits (not common) (Fig. 2A) or infrarenal aortohepatic conduits (most common) 5 (Fig. 2B, C, Fig. 3). Infrarenal aortohepatic conduits are passed through the transverse mesocolon and can be behind the stomach and anterior to the pancreas (Fig. 3A), or behind both the stomach and the pancreas5 (Fig. 3B). Even with apparently the simplest types of surgical arterial communications, the arterial anastomosis may not be primary or singular, but may be via an interposition vascular graft (Fig. 4). Interposition grafts between visceral arteries are resorted to when (1) the arterial stumps of either native and/or graft are too short to be approximated for a primary anastomosis, (2) the arterial connection is being revised (revascularization) or occasionally in cases of retransplantation, and (3) revascularization with an extra-anatomic bypass in case of porta hepatis infection (eg, bile leak, arteritis/mycotic pseudoaneurysm, or subhepatic collections).1,5,9-16,18 Interposition vascular grafts include autologous arterial or venous grafts or expandedpolytetrafluoroethylene (e-PTFE) synthetic conduits. Most aortohepatic conduits originate from the infrarenal aorta and when created by autologous material (vein or artery) may be composed of several segments and thus may have more than two anastomoses. A single segment conduit of any sort has at least two anastomoses. Regarding conduits, the number of anastomoses is one more than the number of segments used in the conduit (Fig. 1B, Fig. 2B). It should be noted that studies that have more cases of conduits (whether aortohepatic conduits or viscerohepatic conduits) increase the incidence of anastomotic arterial complications such as hepatic artery stenoses (HAS). This is because they increase the chance of HAS occurring at the anastomosis by merely having at least double the number of anastomoses compared with primary end-to-end hepatic artery to hepatic artery anastomosis7,19 (Fig. 1). As mentioned in the introduction to the chapter, there are numerous variables due to several dimensions of variations. One of these dimensions is differences in anatomy of the recipient and the donor. Figure 5 shows how two different anatomic variations of the donors can be connected arterially, as a whole liver graft, to a recipient with a classic arterial distribution. The line drawings in Figure 5 are not how the arterial connections should be per-
Figure 3 Infrarenal aortohepatic conduits. (A) Line drawing demonstrating an infrarenal aortohepatic conduit (C) passing retroperitoneally anterior to the pancreas and posterior to the stomach. Ao, abdominal aorta; C, conduit (aortohepatic conduit); CAx, celiac axis (celiac trunk); PHA, proper hepatic artery; P, pancreas; D, duodenum. (B) Line drawing demonstrating an infrarenal aortohepatic conduit (C) passing retroperitoneally posterior to both the pancreas and the stomach. Ao, abdominal aorta; C, conduit (aortohepatic conduit); CAx, celiac axis (celiac trunk); PHA, proper hepatic artery; P, pancreas; D, duodenum.
formed; however, they are just suggestions that help the reader appreciate the numerous possibilities that may be encountered in the arterial surgical anatomy of liver transplantation. The second and less common example (Fig. 5) shows that arterial connections of a liver transplant can have more than one anastomosis without having an interposition vascular graft (conduit) (Fig. 5).
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Figure 4 Viscerohepatic interposition conduits. (A) Sagittally oriented maxium intensity projection (MIP) image from a computer tomographic angiography (CTA) of an adult liver transplant recipient with an interposition graft (conduit) extending from the recipient hepatic artery to the graft hepatic artery (GHA). The interposition graft (conduit) spans between the 2 arrows. Ao, abdominal aorta; CAx, celiac axis (celiac trunk); SMA, superior mesenteric artery; GHA, graft hepatic artery. (B) This is a digitally subtracted angiogram (DSA) in the same adult liver transplant recipient as Figure 4A. The DSA is performed using a microcatheter placed coaxially through a 5-Fr SOS catheter in a frontal projection. The tip of the 5-Fr SOS catheter is in the celiac trunk. The straight segment of the microcatheter represents the interposition graft/conduit (span between arrows). The small arrowheads point to an intrahepatic arterial narrowing possibly as the result of compression from the adjacent pseudoaneurysm (single arrowhead). (C) Line drawing depicting the interposition graft in Figure 4A and B. The graft spans between the 2 anastomoses. Ao, abdominal aorta; CAx, celiac axis (celiac trunk); SMA, superior mesenteric artery; SpA, splenic artery; GDA, gastroduodenal artery; RRA, right renal artery; LRA, left renal artery.
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Figure 5 Recipient-donor arterial preparation and anastomosis. Line drawings demonstrating how two different anatomic variations of the donors and how they can be connected arterially to a recipient with a classic arterial distribution. The line drawings in Figure 5 are not how the arterial connections should be performed; however, they are suggestions that help the reader appreciate the numerous possibilities that may be encountered in the arterial surgical anatomy of liver transplantation. The top row (figure part: X) is a single recipient with invariable anatomy. The bottom row (figure parts: Y and Z) is 2 recipients with different hepatic arterial anatomy: one with a classic arterial distribution (figure part: Y) just like the recipient (figure part: X) and the other with a replaced right hepatic artery off the SMA (figure part: Y). The middle row is the resultant posttransplant arterial surgical anatomy; either XY (combination of recipient X and donor Y) or XZ (combination of recipient X and donor Z). The harvested donor arterial vasculature is shaded gray. Figure parts: XY (combination of recipient X and donor Y): On the left-hand side, the visceral arterial branches of the donor are standard without deviation in variants. The entire celiac axis with its major branches is harvested from the donor and the donor celiac axis is sutured to the recipient common hepatic artery at the branch point of the common hepatic artery and the gastroduodenal artery. Figure parts: XZ (combination of recipient X and donor Z): On the right-hand side, the donor has a replaced right hepatic artery (RRHA) off the superior mesenteric artery (SMA). The left hepatic artery is off the proper hepatic artery of the recipient. The RRHA with its donor SMA segment is harvested along with the left donor hepatic artery (LHA). The ostium of the donor SMA is sutured to the recipient common hepatic artery at the branch point of the common hepatic artery and the gastroduodenal artery. The donor left hepatic artery is sutured to the continuum of the donor SMA segment. OLT, orthotopic liver transplant; CAx, celiac axis (celiac trunk); SMA, superior mesenteric artery; SpA, splenic artery; GDA, gastroduodenal artery; PHA, proper hepatic artery; RRHA, replaced right hepatic artery; LHA, left hepatic artery.
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Figure 6 Anatomical variants of the tributaries of the main portal vein. Illustrations demonstrating the more common variant mesenteric vein confluences that form the main portal vein and their incidences. SpV, splenic vein; IMV, inferior mesenteric vein; SMV, superior mesenteric vein.
Venous Surgical Anatomy Venous surgical anatomy postliver transplantation can be divided into portal venous (inflow vein) anatomy and hepatic venous outflow anatomy. Portal venous surgical anatomy. Portal venous surgical anatomy is usually not as complex (less variables) as what the arterial and biliary surgical anatomy can be. One of the portal venous anatomy variables is the mesenteric venous variants of the recipient (Fig. 6). When the portal vein of the recipient is too small, the recipient portal vein is dissected beyond its bifurcation.4 The “crutch” of the bifurcation is opened longitudinally (perpendicular to the long axis of the main portal vein) to widen the recipient portal vein to match the larger donor/graft portal vein4 (Fig. 7).
This branch-patch angioplasty technique can be applied to any viscera/vessel (arterial, venous, or even biliary) at a branch point of the lesser caliber vessel (see outflow venous surgical anatomy, Fig. 10).4-5 When the recipient or graft portal vein(s) fall short of one another, an interposition graft can be used to bridge the recipient and graft portal vein4 (Fig. 8B). Reasons for having short portal vein stumps include: poor surgical techniques including donor harvest, or excision of damaged vein segments from intraoperative iatrogenic injury, iatrogenic injury from deeply placed endothelialized transjugular intrahepatic portosystemic shunt (TIPS) stents, or segmental chronically thrombosed and organized portal vein. If the portal vein segment extends to and possibly involves the mesenteric vein tributaries of the portal vein, complex venous reconstructions may be required with a long segment of interposition graft4,20 (Fig. 8C). Outflow venous surgical anatomy. Outflow veins include the hepatic vein(s) and the inferior vena cava. Figure 9 gives the sagittal schematic of four different types of venous connections2,4,5,21,22 (Fig. 9A-D). The first three (Fig. 9A-C) are for full grafts and the last two venous connections (Fig. 9D, E) depict reduced grafts/living related grafts. Figure 10 details the sagittal and frontal schematic of preparing a recipient for a “piggyback” venous anastomosis.5,21 Figure 11 details the sagittal schematic of preparing a donor and a recipient for a piggyback venous anastomosis.5,21 The details of reduced or split graft venous outflow connections are depicted in Figure 12.2,4 The outflow veins of a split graft are either (1) connected directly in an end-to-end manner with the recipient veins (Figs. 9E, 12A) or (2) connected directly to the inferior vena cava (IVC) in a patch venoplasty manner2,4 (Figs. 9D, 12B).
Biliary Surgical Anatomy Figure 7 Preparation of a relatively small recipient portal vein. Line drawing demonstrating how a smaller caliber recipient portal vein (RPV) can be branch-patched by dissecting it at its bifurcation (perpendicular to its long axis) so that the diameter discrepancy between the donor portal vain (DPV) and the recipient portal vein (RPV) is reduced.
Biliary-enteric anastomoses. Usually biliary-enteric anastomoses are performed by performing an end-to-side hepaticojejunostomy (Fig. 13, Fig. 14); the end being the end of the common hepatic duct of the graft with the side of a jejunal loop.22 The jejunal loop is more commonly brought up to the hepatic hilum of the graft in a Roux-en-Y manner22 (Fig. 15). Less commonly, the jejunal loop is an interposition jejunal loop22-24 (Fig. 16). The length of the stump of the extrahe-
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Figure 8 Methods to approximate the recipient and donor portal veins. (A) Illustration demonstrating a primary end-to-end portal vein anastomosis between the graft portal vein (PV) and the recipient portal vein (PV). SpV, splenic vein; MV, mesenteric vein(s). (B) Illustration demonstrating an interposition graft bridging the graft portal vein (PV) and the recipient portal vein (PV). The recipient PV is short and its lack of length is compensated by the interposition graft. SpV, splenic vein; MV, mesenteric vein(s); LPV, left portal vein (of graft); RPV, right portal vein (of graft). (C) Illustration demonstrating a graft longer than the one in Figure 8B and extending to and involving the confluence of the splenic vein (SpV) and the mesenteric vein(s) (MV).
Postliver transplantation surgical anatomy
Figure 9 Types of venous outflow and caval anastomosis. Line drawings demonstrating the different outflow vein (hepatic veins or inferior vena cava) connections are oriented between recipient and donor/graft. The outflow veins are sagittally oriented. The first 3 (A-C) are for full/whole grafts and the last 2 venous connections (D and E) depict reduced grafts/living related grafts. RA, right atrium; IVC, inferior vena cava; HV, hepatic vein(s); shaded, donor vessels; not shaded, recipient vessels. (A) This is an intercaval venous outflow connection. In this setting there are 2 anstomoses connecting the donor caval segment. (B) This is a “piggyback” vena caval outflow connection. In this setting there is one anastomosis at the single graft-recipient caval junction. (C) This is a cavoplasty outflow connection, where the graft inferior vena cava (IVC) is patched directly onto an incised recipient IVC. In this setting there is 1 anastomosis circumferentially around the single graft-recipient caval junction. (D) This is a venoplasty outflow connection, where the graft outflow vein pedicle or pedicles are patched directly onto an incised recipient IVC. In this setting there is 1 anastomosis circumferentially around the single graft-recipient venocaval junction. (E) This is 2 end-to-end hepatic vein–to– hepatic vein anstomoses between the outflow graft hepatic vein and their equivalent veins on the recipient side. Combinations of D and E can be performed, where one graft outflow vein is connected to the recipient IVC with a patch venoplasty and the other graft outflow vein is connected to a recipient hepatic vein in an end-to-end manner.
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Figure 10 Preparation of the recipient hepatic vein stump for a “piggyback” caval anastomosis. This is a line drawing demonstrating the preparation of the recipient for a caval piggyback anastomosis. The left-sided images are the sagittal projection and on the right sided images are the frontal projections. The dotted arrow lines signify the line at which the hepatic veins are cut to create one hepatic vein stump (HVS) that can accommodate the caliber of the graft inferior vena cava without to much diameter discrepancy.
patic graft bile duct can vary. The shorter this stump, the closer the jejunal loop is to the graft hilum (hilar plate) (Fig. 17). As the biliary stump gets even shorter and extends into the hilar plate, the recipient can get somewhat of a 3-way single biliary enteric anastomosis with the 2 main intrahepatic graft bile ducts meeting at the single biliary-enteric anastomosis (Fig. 17C). This single anastomosis with the confluence of the 2 main graft bile ducts nearby (Fig. 18) may
falsely appear by cholangiography as a graft with 2 independent biliary enteric anastomoses (ie, Fig. 17B or C look, by cholangiography, like Fig. 17D). This appearance occurs, particularly, when there is superadded stenotic disease at the anastomosis and at the site of the main duct confluences (Fig. 18B). The stenotic disease may be due to perianastomotic scarring or fibrosis, which may be exacerbated by local ischemia (microvascular injury from dissecting around the bile ducts during transplantation and violating the peribiliary vascular plexus) or global graft ischemia (hepatic artery thrombosis) or stenosis.25-27 Furthermore, if the second biliary radical is not appreciated by cholangiography, operators, knowing that there is a single anastomosis, may overlook an isolated segment. Oblique images and watching for hepatic segment void of biliary radicals by cholangiography may help appreciate the isolated biliary segment. Compared with native livers, this may be more difficult in liver transplant recipients with reduced grafts that have hypertrophied and rotated. In these cases careful examination of contrast-enhanced computed tomographic (CT) examinations of the liver may delineate this isolated segment. Biliary-to-biliary anastomoses. Biliary-to-biliary anastomoses can be hepatico-choledochostomies (Fig. 19A, Fig. 20) or choledocho-choledochostomies (Fig. 19B, C, Fig. 21). It should be noted that diameter discrepancies can be seen in biliary-to-biliary anastomoses even in cases of adult-to-adult whole graft choledocho-choledochostomies (Fig. 19C, Fig. 22). When a significant diameter discrepancy is noted it is more commonly a wider recipient common bile duct compared with the donor bile duct; and this is usually due to a larger age difference between recipient [older with wider common bile duct (CBD)] and donor (younger with narrower bile duct). Biliary-to-biliary anastomoses are not necessarily exclusive to whole (cadaveric) grafts, but can also be seen in reduced grafts, particularly living related transplants26,27 (Fig. 20). Obviously, biliary enteric anastomoses are not uncommon in reduced including living related transplants26,27 (Fig. 20, Fig. 23, Fig. 24).
Figure 11 Preparation of the recipient hepatic vein stump and donor inferior vena cava for a “piggyback” caval anastomosis. This is a line drawing demonstrating the preparation of both the recipient and the donor for a caval “piggyback” anastomosis. The left-sided images are the sagittal projections of the recipient (not shaded). The rightsided images are the sagittal projections of the donor (shaded). The center image is the final product (the recipient after the transplantation). HVS, hepatic vein stump; IVC, inferior vena cava; RA, right atrium.
Postliver transplantation surgical anatomy
Figure 12 Types of venous outflow anastomoses in split grafts. These are illustrations demonstrating two different venous anastomoses for split/reduced grafts. These illustrations are the equivalent of the line drawings of Figure 9D and E. RHV, recipient hepatic veins; DHV, donor hepatic veins; RHL, right hepatic lobe graft; LHL, left hepatic lobe graft; J, jejunum; PV, portal vein; Ao, aorta. (A) (Equivalent to line drawing in Figure 9D.) This is a left hepatic lobe reduced graft. This is the split graft that is usually resorted to in infants and children. In this illustration the left lobe transplant is depicted to be connected to the recipient inferior vena cava by a patch venoplasty. (B) (Equivalent to line drawing in Figure 9E.) This is a right hepatic lobe reduced graft. This is the split graft that is usually resorted to in large children or in living related liver transplant adult recipients. In this illustration the right lobe transplant is depicted to be venously connected by one-on-one end-to-end hepatic vein anastomoses. The outflow veins of the graft are not directly anastomosed to the recipient vena cava.
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Figure 13 End-to-side biliary-enteric anastomosis. This is a line drawing demonstrating end-to-side hepaticojejunostomy, where the end of the common hepatic duct (CHD) of the graft is connected to the side of a jejunal loop (J). RHDs, right hepatic ducts; LHDs, left hepatic ducts. Figure 15 Roux-en-Y jejunal loop. This is a line drawing demonstrating end-to-side hepaticojejunostomy, connected to a Roux-en-Y jejunal loop (Roux J). The Roux-en-Y loop is connected end-to-side to the remainder of the small bowel (in situ J).
Figure 14 End-to-side biliary-enteric anastomosis. This is a transhepatic cholangiogram in a whole graft with a hepaticojejunal anastomosis (between arrows). The dashed black and white outline depicts the outline of the jejunal loop (J).
Figure 16 Interposition jejunal loop. This is a line drawing demonstrating end-to-side hepaticojejunostomy, connected to an interposition jejunal loop (J). The interposition jejunal loop is connected end-to-side to the duodenum. P, pancreas.
Postliver transplantation surgical anatomy
Figure 17 Appearance of biliary-enteric anastomoses in whole grafts. Line drawings demonstrating biliary-enteric anastomoses with varying length extrahepatic bile ducts, from a moderate length graft common hepatic duct with a single hepaticojejunal anastomosis (A), to a short graft common hepatic duct with a single hepaticojejunal anastomosis (B), to a wide hepaticojejunal anastomosis at the confluence of the main right and left hepatic duct (C). In addition, a fourth biliary-enteric line drawing demonstrates no graft common hepatic duct. The main right and left hepatic duct are connected independently to the jejunum (J) (D). J, jejunum; RHDs, right intrahepatic ducts; LHD, left hepatic duct.
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Figure 18 Appearance of biliary-enteric anastomoses with superadded stenotic disease. This is a line drawing demonstrating a wide hepaticojejunal anastomosis at the confluence of the main right and left hepatic duct. (A) This is a line drawing showing the anastomosis without superadded disease. (B, C) This is a line drawing showing the anastomosis with superadded stenotic disease. B shows the superadded disease as shaded areas around the confluence of the central bile ducts of the graft. C shows the superadded disease outline; and shows how this “wide-mouth” single anastomosis can be seen by cholangiography as 2 separate anastomoses. RHDs, right intrahepatic ducts; LHD, left hepatic duct.
Figure 19 Appearance of bile-to-bile anastomoses in whole grafts. These are line drawings demonstrating bile-to-bile anastomoses with varying length extrahepatic bile ducts of the graft. RHDs, right intrahepatic ducts; LHD, left hepatic duct; R-CBD, recipient common bile duct. (A) This is a hepatico-choledochostomy with a relatively short extrahepatic graft bile duct (common hepatic bile duct of the graft). (B) This is a choledocho-choledochostomy with a relatively longer extrahepatic graft bile duct (common bile duct of the graft). (C) This is a choledocho-choledochostomy with a diameter discrepancy between the wider recipient common bile duct (R-CBD) and the narrower graft bile duct. This is most likely due to a wide age difference between an older recipient and a younger cadaveric donor.
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Figure 20 Bile-to-bile anastomoses in split right hepatic lobe graft. (A) This is a line drawing showing a hepatico-choledochostomy between a main right hepatic bile duct of a right hepatic lobe graft and the recipient common bile duct (R-CBD). RHDs, right intrahepatic ducts. (B) This is a cholangiogram consistent with the line drawing in A showing a hepatico-choledochostomy between a main right hepatic bile duct of a right hepatic lobe graft and the recipient common bile duct (R-CBD). The arrowheads depict the level of the anastomosis.
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Figure 21 Choledocho-choledochostomy anastomosis in whole grafts. (A) This is a line drawing showing a choledocho-choledochostomy between the common bile duct of the graft and the recipient common bile duct. D, duodenum. (B) This is a cholangiogram consistent with the line drawing in A showing a choledocho-choledochostomy between the common bile duct of the graft and the recipient common bile duct. The arrows depict the level of the anastomosis.
Figure 22 Choledocho-choledochostomy anastomosis in whole grafts with diameter discrepancy. This is a percutaneous transhepatic cholangiogram (PTC) consistent with the line drawing in Figure 19C showing a choledocho-choledochostomy between the common bile duct of the graft and the recipient common bile duct (R-CBD) with a diameter discrepancy between the older and wider R-CBD and the narrower and younger graft CBD. The arrows depict the level of the anastomosis.
Postliver transplantation surgical anatomy
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Figure 23 Biliary-enteric anastomoses in split right-hepatic lobe graft. These are illustrations and images representing a right hepatic lobe split graft (G-RHL) (possibly a right hepatic lobe living related transplant) with a hepaticojejunal anastomosis (HJ). (A) This is an illustration representing a right hepatic lobe split graft (G-RHL) (possibly a right hepatic lobe living related transplant) with a hepaticojejunal anastomosis (H-J). G-RHL, right hepatic lobe graft; RHDs, right intrahepatic ducts; H-J, hepaticojejunal anastomosis; PV, portal vein; J, jejunal loop; Ao, aorta; IVC, inferior vena cava. (B) This is a cholangiogram of a living related adult right hepatic lobe recipient with a hepaticojejunal anastomosis (between arrows). J, jejunal. (C) This is a line drawing representing a right hepatic lobe split graft with a right hepaticojejunal anastomosis. RHDs, right intrahepatic ducts; J, jejunal loop.
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Figure 24 Biliary-enteric anastomoses in split left hepatic lobe graft. (A) This is an illustration representing a left hepatic lobe split graft (G-LHL) (possibly a left hepatic lobe living related transplant) with a hepaticojejunal anastomosis (H-J). G-lHL, left hepatic lobe graft; LHDs, left intrahepatic ducts; H-J, hepaticojejunal anastomosis; J, jejunal loop. (B) This is a cholangiogram of a split cadaveric left hepatic lobe pediatric recipient (now a teenager) with a strictured left hepaticojejunal anastomosis (between arrows). J, jejunal.
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