liver resection 2

8/11/2019 Liver Resection 2

1/6

The Safety

of

Continuous Hepatic

nflow

Occlusion During Major liver Resection

Douglas Quan

and

WilliamJ.

Wall

To evaluate the safety of temporary hepatic inflow

occlusion during major liver resection, we re-

viewed 71 consecutive noncirrhotic patients who

underwent elective liver resection using this tech-

nique. There were 27 males and44 females (mean

age,

54.4

years), the majority of whom had hepatic

malignancies. There were 31 right hepatectomies,

21 left hepatectomies, and 19 extended right

hepatectomies. Ischemic injury of the liver was

assessed using changes in postoperative liver

function tests and patient outcome was assessed

using morbidity and mortality rates. After prelimi-

nary ligation of the blood supply to the lobe to be

removed, global hepatic ischemia was produced

by temporary occlusion of the main portal vein

and hepatic artery proper white the liver paren-

chyma was divided. The average duration of in-

flow occlusion was 59 minutes (range, 25 to 90

he most significant operative hazard during

T major liver resection is hemorrhage. Bleeding is

expected, and it is common to lose moderate to large

volumes

of

blood.' The amount of blood loss has an

impact on morbidity and mortality. Several studies

have documented a correlation between large volume

transfusion during liver resection and poor patient

o ~ t c o m e . ~ - ~

t

has also been suggested that there is an

association between the risk of cancer recurrence and

the amount of perioperative blood t r an s f~ si on . ~ . ~n

addition to those considerations, there are the gen-

eral risks of transmission of disease and the strain on

blood bank resources when large volumes of blood

are consumed. Thus, there are many reasons to

minimize blood loss during hepatic surgery.

To reduce blood loss in patients undergoing liver

resection, it has been suggested that portal and

arterial flow to the liver should be temporarily

occluded when the hepatic parenchyma is di-

vided.8-10This approach is based on the same

principle as Pringle's description in

1908

of portal

triad compression to control bleeding from an in-

jured liver. However, inflow occlusion has not

become routine because of the concern that signifi-

cant ischemic injury of the nonresected liver could

result.

To determine the safety of continuous inflow

occlusion during major liver resection, we retrospec-

tively studied the postoperative course of all patients

minutes). There was no operative mortality, and

no patient developed liver failure. The liver en-

zymes reached their peak on the first postopera-

tive day (mean aspartate aminotransferase

[AST]

level, 283 227 IU/L; mean alanine aminotransfer-

ase [ALT] level, 269 238 IU/L) and they returned

to normal by 7 days. The most common postopera-

tive complications were related to the chest,

wound, and urinary tract. The mean intraoperative

transfusion was 3.4 2.6 U of packed red blood

cells, and 0.94

-c

2.13 U of fresh frozen plasma.

We conclude hat continuous hepatic inflow occlu-

sion for periods of 1 hour during major liver

resection is safe and well-tolerated when there is

no underlying parenchymal liver disease.

Copyright 1996 by the American Association for

the Study of Liver Diseases

who underwent major hepatic resection using this

technique at our center.

Patients

and Methods

Seventy-one consecutive major liver resections using continuous

inflow occlusion performed on a single surgical semce in patients

with noncir rhotic livers between 198 4 and 1993 were remewed.

There were 44 females and 2 7 males ranging in age from 25 years

to 76 years mean age, 54. 4 2 14.2 years). The indications for liver

resection are listed in Table

1.

Metastatic colon cancer was the

most common indication, accounting for 35 of

5

resections for

malignancy There were 2

1

resections for benign disease. The types

of

liver resection were as follows: 31 right hepatectomies, 21 left

hepatectomies, and 1 9 extended right hepatectomies right lobe

plus medial segment of left lobe). Patients who had fibrotic or

cirrhotic livers or who had significant gross fatty change in the liver

were not considered as candidates for inflow occlusion.

During the surgery the patients had monitoring of arterial

pressure, central venous pressure, and urine output Blood was

transfused intraoperatively on the basis

of measured losses and

hemodynamics.

From the Department

of

Surgery, University Hospital, London,

Ontario, Canada.

Addrezs reprint requests to: William J. Wall, MD, FRCS C),

Department

of

Surgery, University Hospital, London, Ontano, N6A

SA.5

Canada.

Copyright

996

by the American Association for the Study of

Liver Diseases

1074-3022/96/0202-000I

3.00/0

Liver

Transplantation an d Surgery,

Vol2,N o

2 March), 1996:

pp

991

04

99


2/6

100

Quan nd Wall

Table 1.

Indications for Liver Resection

Diagnosis Number of Patients

Metastatic malignancy

36

Cavernous hemangioma 8

Primary liver malignancy 9

Cholangiocarcinoma 5

Hepatic adenorna 4

Focal nodular hyperplasia

2

Bile duct cystadenoma 2

lntrahepatic stones

2

Other 3

Total 71

I I

The operative technique was the same in all cases. Bilateral

subcostal incisions were used with an occasional upper midline

extension to the xiphoid process. After complete mobilization of

the lobe of the liver to be removed, the corresponding branch of

the portal vein, hepatic artery, and bile duct in the porta hepatis

was ligated and divided. The venous drainage

of

the lobe to be

resected was then similarly ligated for either right or left hepatecto-

mies. For extended right hepatectomies the right hepatic vein was

ligated but ligation of the middle hepatic vein was left until the

hepatic parenchyma had been divided. The main portal vein and

hepatic artery proper were temporarily occluded while the liver

parenchyma was transected. The artery was occluded with a Drake

aneurysm clip and the portal vein was occluded by a tourniquet

tape. The resections were performed along anatomic planes,

according to the description by Bismuth et al of partial hepatec-

t ~ m y . ~or right or left hepatectomies, the line of parenchymal

division was the plane joining the gallbladder fossa with the

retrohepatic cava. The line between vascularized and devascular-

ized liver was clearly evident after ligation

of

the blood supply of

the lobe to be removed.

In

cases of extended right lobectomy the

line of parenchymal diwsion was approximately 2 cm to the right

of the falciform ligament. Preliminary hilar ligatlon of the vessels to

the right lobe was performed and the feeding vessels to the medial

segment of the left lobe were taken within the liver parenchyma

when the liver was transected. The gallbladder was removed in all

cases. The Cavitron ultrasonic dissector (Valley Lab, Richmond

Hill, Canada) was used to divide the liver. Vascular and biliary

tributaries encountered during the parenchymal division were

ligated with hemoclips or chromic catgut ligatures.

Arterial and portal inflow was restored after completion of the

resection. Bleeding from the raw edge of the liver after restoration

of blood flow was controlled with chromic catgut sutures or

topical hemostatic agents (gelfoam soaked in topical thrombln).

Liver enzymes (aspartate aminotransferase [.&TI, alanine amino-

transferase [ALT] and alkaline phosphatase [ALPI), and serum

bilirubin levels and prothrombin time PT)were monitored during

the first postoperative week.

I t

was part of the routine postopera-

tive management to give

1

or

2 U

of

25

albumin daily for the first

5

days after surgery. Drains were removed between

5

and

7

days if

no bile was evident in the drainage. The patients were kept on

intravenous fluids that included

5

glucose until they were able to

eat.

Statistical analysis was camed out using Students t-test, x

test, analysis of variance, and linear regression using Stawiew

WSuperANOVA (Abacus Concepts Inc, Berkeley, CAI. Values are

expressed as mean

SD

unless orhewise indicated.

Results

The 30-day operative mortality rate was zero, and all

patients were discharged from hospital. Overall, 15

patients 2lo/, xperienced 16 postoperative compli-

cations Table 2). More than half of the complica-

tions were infections related to the chest, wound, or

urinary tract. One patient developed a subphrenic

abscess after a right hepatectomy that was success-

fully treated with percutaneous drainage. One patient

had a bile leak that was controlled by the drain

placed at the time of surgery. The bile leak closed

spontaneously after

9

days of drainage. One patient

developed an inhibitor to factor

V

postoperatively,

which was thought to be caused by an idiosyncratic

reaction to topical thrombin placed on the raw liver

edge during the surgery.14 Postoperative morbidity

was not significantly associated with age, gender or

diagnosis benign versus malignant;

P > .05).

The average postoperative hospitalization stay was

14.2

8.0

days range, 7 to 49 days; median,

12

days), Two patients had prolonged postoperative

stays of

48

and

49

days. The first patient required a

prostatectomy for urinary retention after the liver

surgery, and he subsequently developed a pulmonary

embolism. The second patient developed pulmonary

insufficiency and the adult respiratory distress syn-

drome and needed assisted ventilation for 1 week

after the hepatic resection. She made a slow but

complete recovery.

The mean duration of inflow occlusion was 59

I _

Table

2. Postoperative Complications

Complication Number of Patients

Wound infection

Urinary infection

Pneumonia

Pulmonary embolism

ARDS

Subphrenic abscess

Bile eak

Urinary retention

Total

3

1

1

1

1

15


3/6

Liver Ischemia During

Partial

Hepatectomy

101

15

minutes median,

60

minutes; range, 25 to 90

minutes). The mean intraoperative blood transfusion

was 3.4 * 2.6

U

of packed red blood cells median, 3

U ; range, 0 to 19 U . Three patients required no

transfusion. Only one patient required more than

eight

U

of blood. This patient had a large angiosar-

coma that was intimate with the retrohepatic vena

cava, and when the tumor and the liver were being

mobilized, an opening was inadvertently made into

the inferior vena cava that resulted in sudden,

massive blood

loss.

Duration of inflow occlusion did

not correlate with the amount of transfusion r2

=

0,001 .The mean intraoperative transfusion of fresh

frozen plasma was

0.94

2.13

U

Transient elevation occurred in the AST and ALT

levels during the first 7 postoperative days. The

enzymes reached their peak on the first postoperative

day and then decreased to preoperative levels by 7

days Figs

1

and

2 .

The alkaline phosphatase

decreased slightly during the first

3

days after surgery

and began to increase by the fourth day Fig 3). The

level of enzymes did not significantly correlate with

the duration of inflow occlusion r2 = 0.079 and

0.090

for AST and ALT, respectively) nor did they

correlate with the postoperative complications listed

in Table

2.

The same was true for the serum bilirubin.

Hyperbilirubinemia was common in the immediate

postoperative period and the average serum bilirubin

level was still approximately three times normal by

the end of the first postoperative week Fig

4).

However, no cases of prolonged jaundice were ob-

served.

The mean preoperative PT was

10.2

seconds. It

was slightly prolonged on the first and second

400

PF ? E O P I 2 3 4 5 7

DAY

Figure 1. Mean +SD) AST levels in 71 patients

who underwent major liver resection norm al, 10

to 30 IU/L).

PREOP

I 2 3

4

5 6 7

DAY

Figure 2. Mean (+ SD) ALT levels in 71 patients

normal,

5

to 30 IU/L).

postoperative days 12.5 seconds and 12.6 seconds,

respectively), but the difference was not statistically

significant.

Discussion

The safety and success of liver resection depends

upon effective control of bleeding during surgery and

the ability of the nonresected lobe

to

sustain life in

the immediate postoperative period and regenerate to

a normal volume within a few months from surgery.

In this study of major liver resections, continuous

vascular inflow occlusion resulted in modest blood

loss, and the changes in liver function tests after

surgery did not suggest that it caused any significant

ischemic injury to the liver. There were no manifesta-

0 1

I

PREOP

I

2 3

4

5

DAY

Figure 3. Mean (+ SD) alkaline phosphatase lev-

els normal, 18t o 113 IU/L).


4/6

102

Quan and Wall

o o r

tions of liver insufficiency, and although the rate of

liver regeneration after surgery was not documented,

the clinical course of the patients did not suggest that

there was any impairment of the regenerative re-

sponse. Neither ascites nor prolonged jaundice were

observed in the postoperative period. Inflow occlu-

sion did not seem to have caused any adverse effects

in this series of patients. The complications that

occurred were typical of those that are commonly

reported after liver or other major abdominal surgery

and there was no evidence that inflow occlusion was

causally related to any of them.2-5

The concept of an exquisite sensitivity of the liver

to ischemia originated in experiments in dogs more

than 4 decades The canine model of liver

ischemia does not directly reflect human physiology

because of the unique hepatic vein sphincters in dogs

and the presence of bacteria in their portal blood that

resulted in hepatic gangrene after ligation of the

hepatic artery. It was erroneously assumed that the

human liver was similar, and the warning was given

that the liver should not be subjected to warm

ischemia for periods of more than

15

or 20 min-

utes.12

In

1978,

Huguet et a18 reported

9

patients who

had both portal and caval occlusion for an average of

38 minutes without mortality. Stimulated by that

report, we studied experimental hepatic ischemia in

a pig model.16 Those experiments and data from

Nordlinger et all7 showed that the porcine liver could

tolerate periods of normothermic inflow occlusion

(with simultaneous portal decompression) for

90

to

120 minutes. Extension of the ischemic period to

180

minutes resulted in greater physiological and

clinical abnormalities, and some of the animals did

not survive.18 Based on those experiments and the

handful of reported clinical cases until that time, we

began using inflow occlusion during major liver

resections. Over the past

10

years there have been

sporadic reports, mainly from the same centers, that

have shown that the human liver has considerable

tolerance for ischemia at normal body temperature.8-

Reported experiences indicate that it is safe to

use inflow occlusion for 60 minutes, and our results

show that it is possible to use inflow occlusion for as

long as 90 minutes without producing serious liver

injury.

Significant bleeding may occur at any of three

stages during liver resection. The first is during the

initial mobilization of the lobe to be resected. Prob-

lematic bleeding may occur at this stage if a vascular

tumor is present that is adherent to adjacent struc-

tures, ie, diaphragm, retrohepatic cava, retroperito-

neal tissues, etc. The second is when the liver is

divided and intrahepatic vessels are secured. Bleed-

ing at this stage is most likely to be reduced by inflow

occlusion. The third stage of bleeding occurs from

the raw edge of the liver after completion of the

resection, when blood flow is restored. The technical

advantage of a relatively bloodless field during the

second stage has permitted accurate and secure

control of vascular tributaries such that significant

bleeding from the raw edge, after inflow is restored, is

minimal. Thus, we have not found

it

necessary to

reinstitute inflow occlusion during the third stage.

There are several variations on the theme of inflow

occlusion, and the modifications include intermit-

tent inflow occlusion, total vascular exclusion, and

hypothermic vascular exclusion. Intermittent as op-

posed to continuous inflow occlusion has been

recommended by some to give the liver a periodic

drink with the intention of reducing the possibility

of ischemic injury. Intermittent release at 5- to

20-minute intervals has been reported with good

results.20~21ur results suggest that this approach is

unnecessary. Indeed, there is evidence suggesting

that intermittent reperfusion may be harmful.22Reper-

fusion injury has been shown to be an important

component of tissue damage from ischemia, and it

may be that subjecting the liver to several reperfusion

episodes could cause more harm than a single,

prolonged period of continuous ischemia. Complete

hepatic vascular exclusion was described as early as

1966 by Heaney et al.23 for the resection of difficult

tumors. In a series of

51

patients

(38

had major liver

resections) who underwent total hepatic vascular


5/6

Liver Ischem ia

During

Partial Hepatectomy

103

occlusion, Bismuth et a124 eported a low transfusion

rate of 1.4 U of packed red blood cells and mortality

and morbidity rates that are similar to our results.

Recently Habib et aI2* reported good results with

total hepatic vascular exclusion for a mean period of

37 minutes in

47

patients. There was no 30-day

mortality, and the average transfusion was 930 mL of

blood. Total vascular exclusion achieves the best

possible vascular control, because the vena cava is

isolated above and below the liver in addition to

occlusion of the portal vein and hepatic artery. That

approach may be most suited to the unusually large

tumors that lie in close proximity to the vena cava,

during which there is the risk of producing a tear or

hole in the vena cava. Total hepatic vascular exclu-

sion may cause significant hemodynamic effects with

a decrease in the mean arterial blood pressure and a

reduced cardiac i n d e ~ , ~ ~ , ~ 'hanges that do not occur

with portal triad occlusion alone. The most extreme

approach is that of cooling the liver as part of vascular

exclusion, as described by Fortner et aL2* That

technique would only seem necessary if several hours

of liver ischemia were required.

The increase in liver enzymes during in the first

few days after the resections in our series was

moderate and it may be explained by local tissue

injury at the line of the liver transection plus the

effect of the transient ischemia on the nonresected

lobe of the liver. The brief increase and subsequent

decrease of the aminotransferases observed in the

patients in

our

study are similar to what has been

documented after major liver resection without in-

flow occlusion.2yThis suggests that tissue trauma at

the line of resection is primarily responsible for the

acute change in the liver enzymes. One study by

Makuuchi et aI3O showed no significant difference in

the aminotransferase level between two groups of

patients with and without intermittent inflow occlu-

sion during liver resection with a mean occlusion

time of 30 minutes.

We have been reluctant to apply continuous

inflow occlusion to patients in whom the liver was

found to be grossly fatty at the time

of

surgery

because of the experience with fatty livers in transplan-

t a t i ~ n . ~ 'atty livers do not tolerate cold preservation

well, and there is recent experimental evidence

showing that livers laden with fat do not tolerate

warm i~chern ia.~'W elso did not use this technique

in patients who had cirrhotic livers. Nonetheless, two

clinical reports have shown that inflow occlusion

appears to be safe even in cirrhotic livers for periods

of 30 to 57 minute^.^^,^^ In those studies, most of the

patients were Child's class

A

which may be relevant

to the results.

We doubt that absolute hepatic ischemia was

created by the technique that we have used. Some

collateral arterial supply to the nonresected lobe of

liver exists in the undivided ligamentous attachments

of that lobe, and there

is

likely some supply via small

collateral channels within the connective tissue of the

porta hepatis.

s

opposed to methods in which a

clamp is applied across the entire portal triad, we

isolated and occluded the hepatic artery proper and

the portal vein leaving other vascular tributaries in

the hepatoduodenal ligament undisturbed. When

this technique was used in pigs, we found there was a

residual flow of approximately 10

of

the preocclu-

sion flow as measured by Xenon washout.'* Whether

that residual flow has any clinical significance in

preventing ischemic injury to the remainder of the

liver is unknown.

In conclusion, continuous hepatic inflow occlu-

sion is a safe technique and was not harmful to the

liver for periods of 1 hour. It offers technical advan-

tages without compromise to the liver in the immedi-

ate postoperative period.

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