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11
Popliteal vein
13
Junction with
supercial vein
Greater
saphenous vein
12
Incompetent
communicating vein
Incompetent
communicating
vein divided
Vena caval interruption
1
Incision
Peritoneum
2
Ureter
Inferior vana cava
Lumbar vein
Clip
3
Inferior
vena cava
Renal vein
Lumbar veins
363
4
Inferior vena cava
PLATE
171
S P
P H
INDICATIONS Portal decompression is indicated in patients who have
portal hypertension complicated by gastrointestinal hemorrhage from
esophageal varices that are not e ectively controlled with sclerotherapy
injections. Some procedures completely interrupt portal venous ow to the
liver (end-to-side portacaval shunt), while others selectively decompress
the portal system via a collateral shunt (side-to-side portacaval, splenorenal, and mesocaval). e procedure selected will depend upon the patency of the portal and splenic veins, the results of liver function studies, the
amount of portal venous blood being shunted, and whether the patient is
bleeding acutely.
Selection of patients should be based on their clinical status, results
of liver function studies, and interpretation of hepatic hemodynamics as
determined by radiologic studies. Patients considered for shunting procedures generally should be under years of age. Ideally, there should be
no evidence of encephalopathy, jaundice, ascites, or muscle wasting. Serum
albumin should be above g/dL, prothrombin time greater than . times
normal, and sodium sulfobromophthalein below at minutes. Deviation from these criteria does not absolutely contraindicate surgery, but the
surgical risk is directly proportional to the degree of hepatic decompensation. Finally, liver transplantation may be considered.
Shunting procedures for portal hypertension can be divided into three
types: portacaval, splenorenal, and mesocaval. figures a through f show
diagrammatically the basic surgical choices for diversion of the portal
venous ow.
PORTACAVAL SHUNT
e primary indication for portacaval shunt is the control of massive
upper-gastrointestinal hemorrhage from varices which cannot be controlled with endoscopic ablation or when transjugular intrahepatic portosystemic shunts (TIPS) are not available. Portacaval shunts are sometimes
preferred when there has been prior splenectomy, splenic vein thrombosis,
reversal of ow in the portal vein, thrombosed splenorenal shunt, ascites,
or hepatic vein thrombosis. e selection of a direct portacaval shunt, of
course, depends upon the demonstration of a patent portal vein preoperatively or at laparotomy.
e side-to-side anastomosis (figure a) has been preferred by some in
the presence of portal hypertension with no evidence of a rise in pressure
on the hepatic end of the temporarily occluded portal vein. is suggests
that the arterial blood supply is going through the liver and that lowering of
the portal pressure by the side-to-side anastomosis with the vena cava will
not result in diversion of the arterial supply to the liver. Another advantage of this type of shunt is that it decompresses the hepatic sinusoids, and
this may be bene cial in the treatment of patients with intractable ascites
accompanied by variceal hemorrhage.
e usefulness of the portacaval shunt in the treatment of refractory
ascites is not accepted universally, although several studies have suggested
that this is an e ective mode of therapy. If shunting is indicated to control
ascites, the side-to-side shunt or double end-to-side shunt is usually preferred. is is particularly true in unusual cases of hepatic vein thrombosis
(Budd-Chiari). No decompressive procedure on the portal system has any
bene cial e ect on liver function. e end result of any such operation,
therefore, will depend largely upon the progress of the basic liver disease.
e end-to-side portacaval shunt (figure b) is the procedure of choice
in patients who have had a prior splenectomy, splenic vein thrombosis, or
thrombosis of a splenorenal shunt and in those patients who have reversed
ow in the portal vein. In this procedure the portal vein is ligated in the
hilus of the liver, and the distal portion of the portal vein is anastomosed to
the inferior vena cava. is shunt is particularly indicated when there is no
evidence of ascites and when portal blood ow is reversed in the hepatoportal direction, as determined by a rising pressure in the hepatic end of the
temporarily occluded portal vein. With the end-to-side anastomosis, all of
the portal venous blood ow is shunted from the liver, while hepatic artery
ow to the liver is preserved.
See Plates and for details of the portacaval shunting procedures.
SPLENORENAL SHUNT
In the presence of extrahepatic block of the portal vein, secondary hypersplenism, prior biliary surgery, and/or cavernomatous changes of the portal vein, a shunt between the splenic vein and le renal vein may be the
procedure of choice, provided the splenic vein is patent and of adequate
size. If it is necessary or desirable to remove the spleen, a conventional
splenorenal anastomosis (figure c) may be performed. e distal splenorenal shunt (Warren shunt, figure d) retains the spleen and, while
selectively decompressing the esophageal varices, allows maintenance
of portal pressure and perfusion of the liver, thus providing protection
against hepatic encephalopathy. is shunt is particularly indicated in the
presence of normal liver function, high volume of portal ow to the liver,
minimal hepatocellular disease, marked splenomegaly, or idiopathic portal hypertension. e procedure consists of dividing the splenic vein at its
junction with the superior mesenteric vein, ligating the proximal portion
of the vein, and anastomosing the distal portion to the le renal vein. As
an alternative to dividing the splenic vein, an interposition gra may be
anastomosed between the splenic vein and the le renal vein, with ligation
of the splenic vein proximal to the gra as well as ligation of the coronary
and right gastroepiploic veins.
See Plates through for details of the Warren splenorenal shunting
procedures.
MESOCAVAL SHUNT
In most instances portal decompression may be accomplished by portacaval
or splenorenal shunt procedures. However, the Clatworthy mesocaval shunt
(figure e) is necessary in patients who have undergone splenectomy and
have either thrombosis or cavernomatous changes of the portal vein. e
mesocaval shunt is advisable in patients with excessive bleeding at surgery
from periportal or perisplenic vessels. Finally, it should be the procedure
of choice in small children in whom the splenic and/or portal veins may
be too small for a successful procedure (minimal size approximately cm
in diameter). Elective shunts in children should be postponed, if possible,
until the age of years. e procedure consists of division of the superior
vena cava and anastomosis side to end with the superior mesenteric vein.
In cases of emergency, a lesser technical procedure without division of
the inferior vena cava can be accomplished by the interposition of a large
knitted Dacron gra between the vena cava and superior mesenteric vein at
the level of its rst branches (figure f). is modi cation of the mesocaval
shunt (interposition mesocaval shunt or Drapanas shunt) o ers the advantages of a simpli ed technical approach with minimal blood loss.
e details of mesocaval shunting procedures are shown in earlier
editions of this atlas.
MISCELLANEOUS PROCEDURES
Active bleeding from esophageal varices in patients is usually controlled by
sclerotherapy. An alternate approach is to introduce a stapling device into
the lower esophagus through an anterior gastrotomy opening. e esophageal wall is compressed between the two components of the stapler by an
encircling silk ligature. When the stapler is red, a complete transection of the esophagus occurs with excision of a narrow ring of esophagus.
Additional sutures may be taken about the anastomosis for added security.
Since the vagus nerves are divided, a pyloroplasty is performed. e splenic
artery as well as the coronary vein may be ligated. ■
364
A
5
1
5
B
4
3
1
4
3
6
6
8
8
2
9
7
Side - to - side
portacaval
9
2
7
End - to - side
portacaval
5
5
C
4
1
D
1
4
3
3
8
10
12
7
12
10
2
7
2
Splenorenal
9
Splenorenal
(Warren)
5
5
1
E
8
4
3
F
10
1
4
3
6
11
7
2
9
Mesocaval
(Clatworthy)
1. Portal vein
2. Superior mesenteric vein
3. Splenic vein
4. Coronary vein
5. Short gastric veins
6. Inerior mesenteric vein
7. left gastroepiploic vein
8. Right gastroepiploic vein
9. Inferior vena cava
10. Renal vein
11. Common iliac vein
12. Left gonadal vein
9
6
7
10
Interposition
mesocaval (Drapanas)
2
11
365
PLATE
172
INDICATIONS See Plate .
PREOPERATIVE PREPARATION e patient’s ability to tolerate a porta-
caval shunt procedure depends primarily upon the state of liver function
at the time of the procedure. In general, every e ort should be made to
improve the patient’s general nutrition and hepatic state before surgery.
Several weeks of careful medical management of diet, diuretics, and activity are o en necessary. A er a careful history and physical examination,
hepatic function studies and hepatosplanchnic hemodynamic determinations are obtained.
If the patient is bleeding, the acute phase of the hemorrhage from the gastrointestinal tract requires prompt control with sclerotherapy or with an intraesophageal pressure balloon. Vasopressin may be administered as a continuous
intravenous infusion ( to units per hour) or as a selective intraarterial
infusion (superior mesenteric artery at . to . unit per minute). In addition to vasopressin’s e ciency in reducing portal pressure, it helps evacuate
blood and fecal residue from the alimentary tract. If vasopressin is not administered, it is essential to remove old blood by means of colonic irrigation. is
simpli es exposure and reduces the risk of ammonia intoxication. Nonabsorbable antibacterial agents are used to control nitrogen-splitting bacteria
in the gastrointestinal tract. Blood volume should be restored preoperatively
by careful use of blood, albumin, and lactated Ringer’s solution. Fresh whole
blood products, platelet transfusion, and vitamin K are sometimes indicated,
depending upon the results of coagulation studies.
Liver function must be evaluated using a combination of clinical factors
and laboratory studies. A history of jaundice or ascites indicates an increased
surgical risk. Serum albumin should be above g/dL and prothrombin time
less than . times normal. e partial thromboplastin time and platelet count
should be within normal limits. If there are any deviations from these values,
correction should be attempted with vitamin K and parenteral administration of albumin, fresh frozen plasma, or whole blood. Diuretic therapy may
be necessary in those patients with ascites. Appropriate steps must be taken
to control electrolyte and acid-base balance, especially hypokalemic alkalosis. Coagulation de cits other than those associated with prothrombin may
be corrected with fresh frozen plasma and platelet concentrate. At the time
of surgery, to units of whole blood should be available.
Esophagoscopy and gastroscopy should be obtained routinely along
with appropriate barium studies of the esophagus and stomach. Hepatosplanchnic hemodynamics can be determined by estimation of total hepatic
blood ow, liver scan, hepatic vein catheterization, splenoportography,
indirect portography, and visceral angiography. Total hepatic blood ow
can be estimated using radionuclide scanning. Using hepatic vein catheterization, it is possible to determine the degree of portal hypertension and
the amount of hepatopetal portal blood ow. Splenoportography is usually
the single best source of estimating portal hemodynamics. Prerequisites
for this study are that prothrombin time be less than . times normal and
the operating room be available, should trouble from hemorrhage develop.
is study will reveal the degree of portal hypertension, and according to
the degree of opaci cation of the portal vein, it can give valuable information concerning the degree of compromise of portal blood ow to the liver.
Information obtained from these hemodynamic studies may in uence the
choice of shunt to be performed.
P S
ANESTHESIA A general anesthetic is required. e major hazards during
anesthesia are hypoxia and hypotension. ese hazards are more signi cant than the e ect of any particular anesthetic agent commonly employed
today. However, there is su cient reason to suspect the possible danger of
using halogenated compounds in patients with impaired liver function, and
therefore these agents should not be used during the operation. e other
commonly employed general anesthetic agents and the muscle relaxants
appear to have no adverse e ect on liver function. Provision should be made
for the rapid administration of blood and uids in adequate amounts.
POSITION Elevation of the right side to a -degree angle aids in extension
of the right subcostal incision into the ank and provides additional exposure for this procedure. If the choice between the portacaval and splenorenal shunt has not been made before operation, the patient should be le in
the supine position so that either procedure may be carried out merely by
extending the initial central incision in the appropriate direction.
OPERATIVE PREPARATION e skin is cleansed higher than the nipples
and well down to the symphysis. Likewise, the chest, particularly on the le
side, should be prepared, since an extension of the incision into the thorax
may be necessary.
INCISION AND EXPOSURE Along the right subcostal margin, an incision
is made crossing the le rectus muscle and extending well into the ank
(figure 1a). Satisfactory exposure may also be obtained with a large midline incision that extends to the xyphoid (figure 1b).
DETAILS OF PROCEDURE e routine exploration is carried out a er the
peritoneal cavity is opened. e diagnosis of portal hypertension is con rmed by catheterization of an omental vein (figure 2), preferably toward
the stomach. is is useful even if splenic pulp pressure has been measured
preoperatively, since measurement at this time will permit a more valid
comparison of preshunt and postshunt pressures. e pressure usually will
measure cm of saline or higher above the portal vein level. Considerably
lower pressures would not indicate the necessity or desirability of a shunting procedure. If a previous splenoportogram has shown the presence of a
satisfactory portal vein, dissection is begun by mobilizing the duodenum.
If the presence of a suitable portal vein for shunting is in doubt, this vein
should be isolated and surveyed with a portal venogram before exposure of
the vena cava. Collateral venous networks are usually enlarged considerably
over the posterior peritoneum and subject to increased pressure. erefore,
this normally avascular area may be quite the opposite, and dissection during the Kocher maneuver should progress by clamping and ligating the peritoneal surfaces, rather than by making the usual simple incision lateral to the
descending portion of the duodenum (figure 3). is precaution applies
to all dissection during this procedure in the retroperitoneal space and in
the hepatoduodenal ligament. e inferior vena cava ordinarily is exposed
without great di culty (figure 4). A required additional exposure may be
obtained in the presence of an enlarged caudate lobe of the liver by resecting
a portion of that lobe. rough-and-through mattress sutures of silk are
placed to control the bleeding before the liver is divided. e caudate lobe is
freed from the vena cava, and the veins encountered are ligated (figures 5
and 6). Argon-beam electrocoagulation may be useful.
CONTINUES
366
31
1
30 cm
3
B
A
2
4
Level of the portal vein
20
Manometer
Liver
Colon
Kocher maneuver
Freeing attached caudate lobe
5
Incision
Duodenum
Caudte lobe
Liver
Vena cava
Duodenum
Pancreas
Mattress sutures
6
Small vein
Vena cava
Stump of caudate lobe
Vena cava
367
PLATE
173
DETAILS OF PROCEDURE e portal vein is next identi ed
in the hepatoduodenal ligament by the same careful dissection (figure 7).
It may be helpful during this dissection to place a tape or rubber tissue drain
about the common bile duct in order to facilitate exposure of the portal vein
(figure 8). e portal vein should be exposed from the hilum of the liver to
the superior surface of the pancreas, where the usual pancreatic tributaries
should be located and protected. Once the three structures of the hepatoduodenal ligament have been identi ed clearly, the remaining adipose tissue
containing enlarged venous and lymphatic channels may be divided in order
to bring the portal vein in proximity with the vena cava (figure 9). e area
at which the portal vein crosses closest to the cava is ordinarily just proximal
to the entrance of the renal veins.
At this point, if a side-to-side shunt has been decided upon, two noncrushing clamps are applied to the portal vein so that it may be rotated
to expose its inferior surface (figure 10). is is necessary to prevent
twisting or angulation of the portal vein as the anastomosis is accom-
P S
plished. Two points must be borne in mind in preparing the anastomotic
sites. e rst is that the portal vein and the inferior vena cava are not
parallel to each other; therefore openings in the longitudinal axis of each
vein would result in twisting of the anastomotic site when the clamps are
released. It is necessary to incise the portal vein obliquely to avoid any
twisting (figure 11). Second, a simple longitudinal window, either in the
portal vein or in the vena cava, is not adequate for a satisfactory shunt
because of the low pressures in the venous system. A simple slit opening will behave more like a valve and tend to close, resulting in a high
incidence of shunt failure. e anastomosis should be between windows
cut in the veins by excising a de nite portion of their walls in an elliptical fashion (figure 12). Usually it is not necessary to cross-clamp the
vena cava completely. A curved, noncrushing clamp, placed to exclude
a portion of the lumen, is satisfactory for this purpose (figure 13). e
anastomosis should be made so that it is at least as large as the diameter
of the portal vein.
CONTINUES
368
7
Portal vein
Hepatic artery
Portal vein
8
Duodenum
Common duct
9
Fat and nodes
below portal vein
Duodenum
Common duct
Portal vein
Inferior vena cava
Penrose drain
Portal vein
10
Common duct
Duodenum
11
Proposed anastomosis
Portal vein
Vena cava
Vena cava
12
Portal vein
Opening in portal vein
13
Windows to
be removed
Vena cava
369
PLATE
174
DETAILS OF PROCEDURE e anastomosis itself is usually
accomplished by a continuous suture of ne, nonabsorbable suture material on atraumatic needles. Two angle sutures of arterial synthetic
material are placed with knots tied on the outside (figure 14). Both the
portal vein and the inferior vena cava are very fragile. It is therefore necessary to use the utmost caution during the suturing process to avoid trauma
to these vein walls. is caution should apply not only to the surgeon doing
the actual suturing but equally, if not more, to the assistant holding the
clamps. A very slight shearing force created by shi ing the vascular clamps
in relation to each other may easily disrupt a partly completed anastomosis.
Leaks from the anastomotic site, particularly along the le side of the anastomosis, may be di cult to expose for subsequent resuturing. e anastomosis is completed (figures 15 and 16) and the occluding clamps are
released one at a time to check the adequacy of the suture line. Although
the portal vein represents the high-pressure system in this anastomosis, it is
usually convenient to release one of the portal clamps rst, since these are
normally easier to reapply if hemostasis is not satisfactory. A er all clamps
are released, it is frequently possible to detect the functioning of the shunt
by visible turbulence in the vena cava. Palpation of the opening between
the two veins by invaginating the anterior wall of the portal vein can also
be used to verify the patency of the anastomosis. Repeat measurement of
pressure in the portal system will normally show that it has been reduced to
about half of its preoperative level.
P S
END-TO-SIDE PORTACAVAL SHUNT
e completed end-to-side anastomosis is illustrated (figure 17). is is usually accomplished by dividing the portal vein as close as possible to the liver
hilum. It is important not to leave the proximal stump of the portal vein too
short, since this is a large vein and under considerable pressure. One should
leave room for a double ligature, the second being a trans xation suture ligature with several millimeters of vein cu to assure adequate control of the
hepatic side of the portal vein (figure 18). A longer stump of portal vein is
retained if a double end-to-side shunt is indicated (figure 19). A noncrushing vascular clamp is placed on the portal vein as close to the pancreas as possible to leave the maximum amount of portal vein free for the anastomosis
(figure 19). Again, the appropriate side on the inferior vena cava is selected,
excluded by a partially occluding vascular clamp, and an ellipse of vein wall
is excised. A single-layer continuous anastomosis of arterial synthetic suture
is accomplished as described for side-to-side anastomosis (figure 20).
Although this is an easier anastomosis to accomplish, the same precautions
apply here concerning the fragility of the vein walls. A er the anastomosis
has been completed, the clamps are removed individually. If hemostasis is
satisfactory, the procedure is concluded as described above.
CLOSURE e incision is closed in layers (figures 21 and 22). Drainage
of the right upper quadrant is ordinarily not required unless there has been
unusual trauma to the liver, pancreas, or biliary system. Retention suturing
may be useful.
POSTOPERATIVE CARE In the immediate postoperative period it is impor-
tant to prevent hypoxia; therefore, routine administration of oxygen is recommended for the rst to hours. Central venous pressure combined
with serial hematocrits should be monitored to assure maintenance of an
adequate blood volume.
Because this type of shunt has the highest incidence of hepatic coma,
postoperative e orts to decrease protein catabolism should be continuous.
During the period of no oral intake, the patient should be given a minimum
of g of carbohydrate per day to prevent the undue breakdown of protein. When oral intake is resumed, protein should be restricted initially to
g per day. If tolerated, gradual increments, usually g every other day,
may be instituted until a level of to g of protein is reached. Tolerance
of this nitrogen load may be checked with fasting and -hour postprandial
blood ammonia levels. If signs of hepatic insu ciency develop, protein intake should be further restricted and intestinal antibiotics administered.
e prothrombin activity must be monitored and supplemental vitamin K given as indicated. Continued administration of multiple vitamin
preparations is also useful.
Ascites may be a distressing if not a dangerous problem postoperatively.
Careful monitoring of both uid and sodium intake may prevent or minimize this complication. If ascites develops, it is best managed by severe
sodium restriction combined with diuretics.
e increased incidence of peptic ulceration following portacaval shunt
should be remembered and appropriate (low-sodium) antacid therapy and
proton pump inhibitors be given. ■
370
14
Common duct
Portal vein
A
15
A
16
B
A
Portal vein
Vena cava
End - to - side anastomosis
Stump of portal vein
17
Vena cava
Duodenum
Portal vein
Angle
suture
B
18
B
Stick tie
Portal vein
Posterior row
of sutures
Anterior row
of sutures
B
Line of division
A
Portal vein
A
B
19
Portal vein
Inferior vena cava
20
Portal vein
stump
Vena cava
Duodenum
Portal vein
Common duct
21
Posterior row
of sutures
Pancreas
Vena cava
22
Portal vein
Portal vein
Anterior row
of sutures
Vena cava
Vena cava
371
PLATE
175
INDICATIONS (See Plate .) e selective distal splenorenal shunt may
be indicated in the patient with cirrhosis of the liver without ascites but
with evidence of a major hemorrhage from gastroesophageal varices. e
incidence of encephalopathy may be reduced in comparison with other
types of portosplenic shunts.
PREOPERATIVE PREPARATION ese patients require detailed evalua-
tion of both hepatic and renal function. Severe ascites contraindicates the
procedure. A needle biopsy of the liver evaluates the basic hepatic disease
as well as determines the possibility of acute in ammation caused by alcoholic hepatitis or chronic aggressive hepatitis and cirrhosis. e operation
is delayed inde nitely if acute alcoholic hepatitis is found. Except in emergency situations, the hepatic disease should be considered stable before the
shunting procedure is planned.
Preoperative angiography is essential to establish the presence or absence
of portal venous ow to the liver, as well as to obtain a gross estimate of the
volume of portal venous perfusion of the liver. e preoperative angiogram
also determines the patency and anatomic relationships of the mesenteric,
splenic, and portal veins.
In addition, catheterization and visualization of the le renal vein are
essential. ese procedures permit a preoperative evaluation of the structural relationships and reveal any abnormalities or unusual anatomic variations that would make the proposed shunt impossible.
ANESTHESIA (See Plate .)
POSITION AND OPERATIVE PREPARATION (See Plate .)
INCISION AND EXPOSURE e surgeon should be familiar with the anat-
omy of the portal system as well as the veins draining the stomach (figure 1).
Maximum exposure is essential. A long midline incision extending from the
xiphoid to well below the navel may be used (figure 2). e incision may be
made to the right of the navel, and the umbilical vein and round ligament to
S S (W)
the liver ligated and divided. A long bilateral curved incision extending from
the midrectus on the right to well out into the le ank may be preferred,
with the le side of the patient elevated to degrees.
Gentle and limited exploration of the opened abdomen is indicated to
avoid possible hemorrhage from delicate torn vascular adhesions. e region
of the needle puncture for a splenoportogram is inspected for evidence of
continued bleeding. Some type of hemostatic material may be required to
control the oozing site. A biopsy of the liver should be taken.
e gastrocolic omentum is detached from the transverse colon, including the exures, without ligating the gastroepiploic vessels. is ensures good
access to the pancreas and, in turn, the splenic and renal veins. Adhesions
between the posterior wall of the stomach and the pancreas are divided. e
right gastroepiploic vein is divided in the infraduodenal region to interrupt
the collateral venous drainage from the pancreas or intestine through the
gastroepiploic system (figure 3). e right gastroepiploic artery also may
be included in the mass ligature of the veins below the pylorus. Neither the
le gastroepiploic nor the short gastrosplenic veins should be interrupted, in
order to maintain their pathway for drainage of the varices of the upper end
of the stomach and lower esophagus.
e peritoneum along the inferior margin of the body of the pancreas is
divided with special attention to possible injury to the underlying superior
mesenteric vein (figure 4). Gentle nger and instrument dissection may be
used to mobilize the margin and the posterior surface of the body of the pancreas over a distance of to cm. e vascular retroperitoneal tissue over
the superior mesenteric vein is cleared away carefully with good visualization
of the several branches, and the middle colic, coronary vein, and so forth, are
visualized. Careful dissection is continued until the junction with the splenic
vein has been established clearly. It may be easier to identify the medial portion
of the splenic vein rst and follow it into the inferior mesenteric vein. e inferior mesenteric vein is not always a reliable landmark, since it may empty into
the superior mesenteric vein instead of into the splenic vein.
CONTINUES
372
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