Temporary Liver Transplantation in Acute Liver Failure Alfonso Diaz, MD;

Jean-Baptiste Ricco, MD; Dominique Franco, MD;

\s=b\ The ability of a heterotopic graft to prolong life in animals dying in hepatic coma due to liver necrosis has never been definitely established. Acute hepatic failure was produced in 15 dogs by an hour of total interruption of the hepatic blood supply. Nine dogs received an intrathoracic hepatic homograft concurrently. Nontransplanted dogs died within 21 hours in hepatic coma, while transplanted dogs survived significantly longer (P < .001). In all transplanted dogs, biological signs of hepatic failure were corrected in 24 hours. In four animals, the graft was removed on the fifth postoperative day. Two of those survived for 10 and 15 days respectively with normal hepatic function. These results demonstrate that a temporary heterotopic liver transplant is able to support life during the acute, normally lethal phase in dogs with massive liver necrosis. (Arch Surg 112:74-78, 1977)

after acute hepatic insufficiency depends on the extraordinary ability of the liver to regenerate. In some cases of lethally acute hepatic failure, one can imagine that the remaining liver tissue, which is unable to sustain life during the acute phase of the disease, could actually regenerate enough to resume normal function if the patient could be supported through this period. If such patients are to survive, it is necessary to find a means of replacing the liver for a short period of time. Several procedures have been used to this aim, such as exchange transfusion, cross-circulation, and ex vivo perfusion through charcoal or heterologous livers. None of these treatments has to date proved effective.' In the last four years certain authors have proposed replacement of the failing liver by a heterotopic temporary liver transplant. However, the value of this procedure has never been clearly demonstrated. None of the experimental models used so far-4 has been totally convincing. Experimental proof of the ability of a temporary hepatic graft to support life during acute lethal necrosis of the liver requires (1) the production in animals of an acute pure hepatic insuffi¬ ciency by necrosis of the liver, always lethal, but poten¬ tially reversible; and (2) a functioning model of heterotopic liver transplant. In this investigation, we have studied the effect of a transient intrathoracic liver graft in dogs with ischemie

Recovery

Accepted for publication July 14, 1976. From the Laboratoire de Recherches Chirurgicales, Villejuif (Drs Ricco, Franco, Szekely, and Bismuth and M. Gigou). Dr Diaz is practicing medicine in Santiago, Chili. Reprint requests to Laboratoire de Recherches Chirurgicales, H\l=o^\pital Paul Brousse, 14 avenue Paul-Vaillant Couturier, 94800 Villejuif, France (Dr Franco).

M.

Gigou; Anne-Marie Szekely, MD;

Henri

Bismuth, MD

necrosis of the liver in order to determine if this procedure would prolong survival in these animals and would support life for a period of time long enough to enable the necrosed host liver to regenerate. MATERIALS AND METHODS Fifteen mongrel dogs, weighing 20 to 25 kg each, were used. Before operation, neomycin (2 gm/day) was given orally for four days. The animals were divided into two groups: group A (six dogs), ischemie hepatic necrosis alone; and group (nine dogs), intrathoracic hepatic transplantation plus ischemie necrosis of their own livers as in group A. No immunosuppressive drug was given. On the fifth postoperative day the graft was removed. Liver necrosis was obtained by temporary suppression of the entire hepatic blood inflow for 60 minutes according to a technique similar to that previously described by Misra et al. The operation was carried out via midline incision. All liver ligaments were divided and a small side-to-side portacaval shunt was constructed. A vascular clamp was placed across the porta hepatis above the portacaval anastomosis for 60 minutes. After removal of the clamp, the portacaval anastomosis shunt was left in place. Hetero¬ topic liver graft was performed, using a minor modification of the technique of Lecompte et al." The graft, taken from a 10-kg mongrel donor, was placed in the right pleural cavity of the host by thoracotomy. Revascularization of the graft was obtained by endto-end anastomosis between recipient right internal mammary artery and the hepatic artery of the graft, and by an end-to-end anastomosis between the right superior pulmonary artery of the recipient and the portal vein of the graft. The suprahepatic inferior vena cava of the host was anastomosed end-to-side to the superior vena cava just above the right atrium. Bile was drained through a thoracic cholecystostomy. In both groups, consciousness was assessed every three hours during the first 36 hours and then once a day. Serum glutamic pyruvic transaminase level (SGPT, normal 5 to 17 mU/ml), plasma fibrinogen level, and prothrombin time were measured before the operation, every three hours for the first 36 hours, daily until the fifth postoperative day, and then every three days. In group B, surgical liver biopsy specimens were taken from the graft and host liver on the fifth postoperative day and then every five days. At autopsy, patency of anastomoses was checked. Specimens were obtained from both livers for pathological studies. Slides were stained according to Masson trichrome and hematoxylin-eosin-saffron techniques. Specimens were also taken from every liver for bacteriological studies. '

=

Group A:

RESULTS Ischemie Necrosis of the Liver

All the animals died with a mean survival time of 21 hours following the beginning of ischemia (range, 10 to 28

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hours). The dogs awoke for

two to three hours and then into identical to what has been coma, lapsed progressive described by Rappaport et al.7 Postoperative biochemical determinations are indicated in Fig 1. The SGPT level increased and reached a peak of 1,000 ± 500 mU/ml 18 hours following ischemia and then decreased. Prothrombin time increased and fibrinogen level decreased until death. At the 18th hour, the fibrin¬ ogen level was 0.9 ± 0.2 gm/liter and the prothrombin time was 26 ± 6 seconds. None of the dogs demonstrated clinical hemorrhagic diathesis, only a slight oozing of blood from the incision after the sixth postoperative hour. At autopsy, the liver was dark red, patchy with dissemi¬ nated black spots. Microscopically, necrosis of hepatocytes predominated in the central and intermediary areas of the lobule (Fig 2); it was only partial in the periportal areas, where a few hepatocytes remained normal. Liver tissue cultures remained sterile.

Group

B: Intrathoracic Hepatic Transplantation Plus Ischemie Necrosis of the Liver

Mean survival time after beginning of the ischemia was days (range, 32 hours to 25 days). This was signifi¬ cantly different from survival in group A (P < .001). All dogs were fully conscious 12 hours after operation. Causes of death are summarized in the Table. Two dogs died from technical failure. Three dogs died from hepatic coma, at 48, 60, and 72 hours after operation. In these dogs, thromboses of the hepatic artery and portal vein of the graft were found at autopsy. Four dogs survived until the fifth postoperative day when the graft was removed. One of them died during the anesthesia. The second died 24 hours later from hepatic coma. Two dogs survived 10 and 25 days respectively following removal of the graft and died from unrelated causes (pneumonitis and wound dehiscence). Biochemical results are indicated in Fig 3. The SGPT level rose to 1,700 ± 600 mU/ml at the 12th hour and then returned to normal levels in five days. During the first 12 hours, the fibrinogen level fell to 1.5 ± 0.5 gm/liter and the prothrombin time increased to 26 ± 6 seconds. Both returned to nearly normal values at five days. After removal of the graft, transient minor changes were observed in the fibrinogen level and prothrombin time, which rapidly returned to normal values in the two dogs with long-term survival (Fig 4). Histological signs of necrosis of the host liver were most evident on the second postoperative day. On the fifth day, mild inflammatory portal and periportal infiltration was present. Marked hyperplasia was noted on and after the tenth postoperative day in the two surviving dogs (Fig 5 and 6). On the 21st day (dog 8), many regenerative and hyperplastic zones were visible, scattered throughout the liver; no fibrosis was observed. In the grafts removed on the fifth postoperative day, disseminated foci of cellular necrosis were present, accompanied by vascular inflamma¬ tory cell infiltration and thrombosis of small vessels, suggesting an acute rejection (Fig 7). In three cases (dogs 3, 4, and 5), thrombosis of the main blood vessels produced subtotal necrosis of the graft. seven

Causes of Death in

Transplanted Dogs (Group B) Cause of Death

Dog

Survival Graft not removed 30 hr 1 32 hr 48 hr

60 hr

Technical failure Technical failure coma: thrombosis of vascular anastomoses of the

Hepatic graft Hepatic

coma:

thrombosis of

vascular anastomoses of the

72 hr

graft Hepatic

coma: thrombosis of vascular anastomoses of the

graft Graft removed 6 5 6 15 25

days days days days

Anesthesia

during Hepatic coma Lung sepsis

removal of

graft

Wound dehiscence

COMMENT

While

apparently evident, the ability of a temporary hepatic graft to prolong life remains debatable. Results of previous experiments have been controversial. Küster and Woods- transplanted dogs whose hepatic lesions were produced by infusion of dimethylnitrosamine. While all nontreated dogs died, the majority of transplanted animals

survived. In the nontreated group, however, death occurred because of gastrointestinal or peritoneal hemorrhage; there was no clinical, biological, or histological evidence of severe hepatic failure. Therefore, whether heterotopic liver grafts acted on acute liver failure remains in doubt. In the work of Lilly et al," necrosis of the liver was obtained by subtotal permanent suppression of hepatic blood inflow, conserving both a small arterial and venous supply to the liver. After auxiliary liver transplantation, dogs survived. It must be stressed that the situation created by this procedure does not realize a typical acute liver failure, since the nontreated animals survived for 72 hours. In addition, others' have been unable to reproduce this exper¬ iment. Huguet et al ' found that heterotopic liver grafts did not improve survival in pigs whose liver was necrosed by permanent and total interruption of liver blood inflow. In fact, seven of the 12 transplanted animals died from peritoneal hemorrhage after transplantation, and the transplanted pigs surprisingly had a shorter survival (mean, three hours and 20 minutes) than the nontreated group (mean, 21 hours), bringing the viability of the heterotopic graft into question. The experimental proof that a temporary liver graft may support life during the acute phase of liver failure and enable host liver regeneration and later host survival requires two conditions: (1) the production of an acute hepatic failure by necrosis of the liver, constantly lethal, with potentially reversible hepatic lesions in case the animal survives; and (2) a satisfactory model of a hetero¬ topic liver graft that does not deprive the host liver of portal blood. The technique of acute liver failure used in the present experiment was derived from the work of Misra et al,3 ie, a transient interruption of the host hepatic blood inflow. In our experiments, mortality was constant when the inter-

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LIVER ISCHEMIA

I

1.—Evolution of SGPT level, ischemie necrosis of liver (group

Fig

fibrinogen level, A).

and

prothrombin

time in

dogs with

S.G.P.T.

30i(mU/mL) 1000

LIVER ISCHEMIA

I

+

TRANSPLANTATION

S.G.P.T.

0

FIBRINOGEN

6i

30i(mU/mL)

(g/U

1000

I*

2 0

FIBRINOGEN

(g/L)

PROTHROMBIN 30 TIME (sec) 20

2 10

0-

0J 0

6 12 18 U hrs

30

PROTHROMBIN TIME

(sec)

20 10

Fig 2.—Liver hepatic coma

necrosis in dog dying in 14 hours after liver ische¬ mia. In centrizonal area (CA), most of hepatocytes are necrosed. There are still viable cells in periportal area (PA) (hema-

toxylin-eosin-saffron,

0

6 12 18 24

36

48 hrs

-//-

4

5

days

Fig 3.—Evolution of SGPT level, fibrinogen level, and prothrombin time during first five postoperative days in dogs with ischemie necrosis of liver and intrathoracic hepatic

transplantation (group B).

240).

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LIVER ISCHEMIA + TRANSPLANTATION

I

REMOVAL OF THE GRAFT

S.G.P.T.

2000i(mU/mL) Fig 5.—Host liver regeneration in trans¬ planted dog (No. 9) 14 days following liver ischemia and nine days after removal of graft. Necrosed cells have been removed, producing collapsed zones (C) scattered throughout liver. In some places, hyper¬

1000

plasia

is

saffron,

FIBRINOGEN

taking place (hematoxylin-eosin37).

(g/L)

4-

0

Fig 6.—Host liver regeneration in trans¬ planted dog (No. 9) 24 days following liver ischemia and 19 days after removal of graft. Most of lobule is composed of hyperplastic columns of hepatocytes (arrows) (Masson trichrome, 240).

PROTHROMBIN TIME 30 i(sec) 20 10

Ò 1'2 24 36 48 hre 5 7 9 11 13 15 days Fig 4.—Typical evolution of SGPT level, fibrinogen level, and prothrombin time in dog 8, which underwent graft removal on fifth postoperative day. Early changes of fibrinogen level and prothrombin time were partially corrected by graft. When liver graft was removed, transient fall of fibrinogen level and increase in prothrombin time occurred; both progressively returned toward normal levels. Death on day 15 was due to pulmonary sepsis.

ruption of flow lasted 60 minutes; dogs exhibited the typical pattern of hepatic coma and had biochemical evidence of acute liver failure, such as coagulation defects, and liver necrosis, as shown by a rise in transaminase values. Preliminary experiments showed that interruption of flow for a shorter duration was not always lethal in the dog; if blood flow was interrupted for more than 60

Fig 7.—Acute rejection of graft removed five days after transplantation. Portal tract is infiltrated with polymorphonuclear in¬ flammatory cells and immunoblasts. indicates portal vein; B, bile duct (hematoxylin-eosin-saffron).

minutes, dogs did not survive the transplantation proce¬ dure. This technique does not permanently deprive the liver of its blood supply and thus enables actual regenera¬ tion of the necrosed host liver to occur. The choice of a technique of heterotopic liver transplan¬ tation involves several considerations. On the one hand, Van der Heyde et aP and Hess et al'1 have emphasized the

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importance of hemodynamic conditions and more particu¬ larly the venous drainage of the transplanted liver. This drainage must be as close as possible to the right atrium. On the other hand, many authors, notably Sfarzi et al,1" have shown that portal blood was necessary for liver regeneration to occur. Thus the maintenance of a portal blood supply to the necrosed host liver is an important condition for the choice of a model of heterotopic liver graft. Intrathoracic hepatic homograft according to the technique that we previously reported" seemed to best fulfill these two requirements: the liver transplanted into the thorax rapidly assumed normal function and proved to be able to sustain life in totally hepatectomized dogs. Huguet et aP suggested that the passage into general circulation of toxic compounds from the necrosed host liver could explain the failure of heterotopic transplantation to prolong survival of pigs with acute liver necrosis. Whether hepatic necrosis really has a damaging effect has never been fully defined. In their work, Huguet et al' showed that heterotopic transplantation into normal recipients of a liver injured by a six-hour period of ischemia led to death.

We have shown in the rat that animals with ischemie liver necrosis had a shorter survival time than rats with total hepatectomy." In the present study, dogs with the intra¬ thoracic liver graft survived despite a massive necrosis of their own livers. It is possible that the effect of tissue necrosis is different according to the type of necrosis and moreover the quantity of necrosed tissue. In the work of Huguet et al,4 permanent ligation of the total blood inflow to the liver may have led to more massive necrosis than does transient liver ischemia. Long-term success of heterotopic liver graft in liver necrosis implies the ability of the host liver to regenerate and to do it before the grafted liver is rejected or otherwise fails to function. Little is known about the possibility of regeneration of a necrosed liver. In man, histological signs of regeneration, as well as an increase in the serum a-fetoprotein concentration, have been observed in patients during recovery from severe viral hepatitis.1J Whether this regeneration would be sufficient to ensure survival is not known. It has been suggested by Hess et al·' that a functional competition might exist between the heterotopic graft and the host liver that could inhibit regeneration of the necrosed liver. In the present investi¬ gation, the homograft was able to support life during the initial period of acute hepatic failure while it did not inhibit regeneration of ischemie livers. Indeed, the host liver regeneration was sufficient on the fifth postoperative day to ensure survival after removal of the graft in two of three animals that could be studied. If competition was present between the two livers, its effect was not great enough to inhibit regeneration. In one dog, however, the necrosed liver was unable to sustain life after removal of the heterotopic graft, and may not have regenerated enough at that time. Temporary hepatic homograft in dogs appears to be an effective treatment of acute liver insufficiency in these

animals. It enabled survival during the period of acute liver insufficiency and made it possible to wait until the necrosed host liver regenerated enough to function normally. These results would suggest that heterotopic liver transplantation might be done in man with severe acute hepatitis or toxic necrosis of the liver, such as in acetaminophen or mushroom poisoning. Several points would merit consideration, however, if this treatment were to be applied: the criteria for choosing the recipient, the precise moment of transplantation, and the precise moment of removal of the graft. This investigation was supported by grant 75-5-014-7 from Institut National de la Santé et de la Recherche Médicale.

References 1. Benhamou JP, Rueff B, Sicot C: Etude critique des traitements actuels de l'insuffisance h\l=e'\patiquegrave. Rev Fr Etud Clin Biol 13:651-658, 1968. 2. Kuster G, Woods JE: Auxiliary liver transplantation in dogs as temporary support in acute fulminating hepatic necrosis. A nn Surg 176:732\x=req-\

735, 1972.

Lilly JR, Anderson KD, Hill JL, et al: Auxiliary liver transplantation in Surg 7:492-498, 1972. 4. Huguet C, Bloch P, Opolon P, et al: Traitement des n\l=e'\crosesaigu\l=e"\sdu foie par transplantation h\l=e'\patique.J Chir 108:397-406, 1974. 5. Misra MK, P'eng FK, Sayhoun A, et al: Acute hepatic coma: A canine model. Surgery 72:634-642, 1972. 6. Lecompte Y, de Riberolles C, Grange D, et al: Canine intrathoracic hepatic homograft. Arch Surg 109:809-811, 1974. 7. Rappaport AM, MacDonald MM, Borowy ZJ: Hepatic coma following ischemia of the liver. Surg Gynecol Obstet 97:748-762, 1953. 8. Van der Heyde MN, Jerusalem C, Schimdt W, et al: The influence of hemodynamies on the microstructure of the heterotopic liver graft. Eur Surg Res 2:152, 1970. 9. Hess F, Jerusalem C, Van der Heyde MN: Advantages of auxiliary liver homotransplantation in rats. Arch Surg 104:76-80, 1972. 10. Starzl TE, Porter KA, Kashiwagi N, et al: Portal hepatotrophic factors, diabetes mellitus and acute liver atrophy, hypertrophy and regen3.

acute liver failure. J Pediatr

eration. Surg Gynecol Obstet 141:843-858, 1975. 11. Franco D, Grange D, Chauvaud S, et al: Ischemic necrosis of the liver in the rat. Eur Surg Res 4:276, 1972. 12. Bloomer JR, Waldmann TA, Mclntire K, et al: Relationship of serum \g=a\-fetoproteinto the severity and duration of illness in patients with viral hepatitis. Gastroenterology 68:342-350, 1975.

Editorial Comment This study suggests that a temporary heterotopic liver trans¬ plant is capable of supporting life during the acute, normally lethal phase of major hepatic injury in dogs. Although only a small number of animals were used, a few of which died of technical failure, the study does lend support to the view that the temporary heterotopic liver may serve as a major temporary hepatic support system. It has been shown by Marchioro, Starzl, and others that in order to function effectively, a heterotopic liver graft should receive portal venous flow from the host, rather than systemic venous flow as in the present study. If the heterotopic liver graft is not placed in the abdomen where it may receive portal venous inflow, it is unclear why placement of the graft in the thorax offers benefit over placement in the pelvis, or even in an extracorporeal chamber attached to the host by grafts to the femoral artery and vein. It is possible, however, that if the heterotopic graft is placed in the splanchnic circulation of the host, the graft might compete with the regenerating liver of the host and thus retard host hepatic repair. Eric W. Fonkalsrud, MD Los Angeles

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