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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_1841_Библиотеки_им_академика_М_И_Перельмана.pdf
DUODENAL TUMOURS
103
Fig. 2.13 Tumour in pancreatic wall and duodenum. Resection preserves the ampulla
and a ‘bubble’ of duodenal wall for re-implantation.
DUODENUM
104
Duodenal diverticula
Although common, duodenal diverticula rarely require surgical intervention.
However, with the advent of ERCP there has been an increased incidence of
duodenal perforation at the time of attempted instrumentation of the bile
duct. Perforation can be managed conservatively with nasogastric suction,
antibiotics, and intravenous nutrition. If the patient deteriorates then surgery
is required. The perforation is often into the lesser sac or retroperitoneally and,
in order to identify the diverticulum, complete Kocherization of the duode-
num is required together with opening of the lesser sac. Cannulation of the bile
duct using an infant feeding tube may be necessary to identify the relationship
of the ampulla to the diverticulum. Once mobilized, closure is usually straight-
forward by direct suture after the excision of excess diverticulum. A bleeding
duodenal diverticulum rarely requires surgery but the principles described for
a perforated diverticulum apply, with partial or complete resection of the
diverticulum usually being required.
Fig. 2.14 Closure using a
Roux-en-Y loop over the
defect, a T-tube to
decompress the biliary
system, and a feeding
jejunostomy.
Section 3
Liver
Anatomical considerations
Our understanding of liver anatomy has been greatly enhanced by the work of
a number of exceptional individuals and particularly the great French anato-
mist Claude Couinaud (Couinaud, 1954 , 1957 ; Hjortsjo, 1951 ; Healey and
Schroy, 1953 ). The current concept describes a liver of eight segments (I–VIII)
( Figs. 3.1 and 3.2 ).
Each is supplied by terminal branches of the portal vein and hepatic artery
and is drained by a bile duct and hepatic veins. The exact shape of these seg-
ments varies from patient to patient but their relationship to each other
remains relatively constant (Couinaud, 1957 ). This segmental anatomical
structure provides a range of surgical options allowing ‘a la carte’ surgery of
the liver. The two principles that need to be considered are adequate inflow to
each liver segment and adequate outflow through the right, left, or middle
hepatic veins. The variability of the venous drainage is considerable and of
Fig. 3.1 The functional division of the liver and the liver segments as seen in the
patient according to Couinaud’s nomenclature.
LIVER
106
particular surgical relevance are significant inferior right hepatic veins
(Makuuchi, 1985 ).
These are said to be present in up to 10% of patients. Their relevance lies in
the fact that a right hepatic vein may be involved in tumour and need resec-
tion. An inferior right hepatic vein may provide adequate drainage of the
remaining right side of the liver and allow an increased hepatic mass to be
retained (Couinaud, 1954 ; Blumgart and Hann, 2007 ). The other rare (less
than 1%) vascular anomaly that needs to be recognized is a right portal vein
not dividing but recurving intrahepatically to supply the left side of the liver
(Couinaud, 1957 ; Bismuth et al ., 1982b ). This anomaly may be detected on CT
scan but when planning a right hepatectomy it is vital to be certain intraopera-
tively that a portal vein is branching to the left in the hilum of the liver. While
Couinaud’s work has demonstrated an extraordinary number of anomalous
structures, these two are probably (in practical terms) the most important.
Liver trauma ( Fig. 3.3 )
Conservative management
The liver is the most commonly injured solid organ following blunt trauma and one
of the most difficult to deal with (Moore et al ., 1990 , 1995 ; Schn˝uriger et al ., 2008 ).
Fig. 3.2 The functional division of the liver and the liver segments as seen in the
ex-vivo position according to Couinaud’s nomenclature.
107
LIVER TRAUMA
Fig. 3.3 Assessment of liver trauma.
Suspected
liver trauma
Initial ultrasound
Equivocal
Stable
Normal
Observe & repeat
if clinical
condition changes
Positive
Negative
Stable
Obvious trauma
Unstable
Unstable
CT
CT
Surgery
LIVER
108
Modern approaches to liver trauma are based on conservative management if
at all possible (Demetriades et al . 1986 , 1999 ; Velmahos et al ., 2003 ). A haemo-
dynamically stable patient can be investigated with a CT scan and managed in
an HDU or ICU. It is well appreciated that frightening CT scans can often be
managed without operative intervention.
If a conservative approach is to be pursued then exclusion of other injuries
needs to be confirmed and close monitoring and serial CT scans should be in
place. If the condition remains stable, the patient can be discharged between
5–10 days, advised to avoid possible abdominal trauma from sport or work,
and rescanned at 6–8 weeks to assess the resolution of the liver findings. If,
during the interim fever, bleeding or pain occur then prompt readmission to
hospital is required. For this reason patients should probably not return to
isolated areas until after the follow-up scan, and particularly where distances
are large, such as Australia, most cases of liver trauma will be managed in this
way (Gates, 1994 ) (Table 3.5).
Some cases of patients having undergone blunt or penetrating trauma will
require a laparotomy for haemodynamic instability (Blumgart et al ., 1979 ;
Asensio, 2003 ). A CT scan may not be always possible and, at laparotomy, liver
trauma may be found. Packing or manual pressure intended to compress the
parenchyma without causing caval compression is the initial aim ( Fig. 3.4 ).
If additional intra-abdominal bleeding is found the source needs to be deter-
mined. Packing and time may be all that is required in some patients and
exploration of a liver laceration should only be attempted if control is not
being achieved (Feliciano et al ., 1986 ; Cué et al ., 1990 ; Krige et al ., 1992 ). In
order to provide the maximal control and obtain the necessary vision of the
bleeding source a number of preliminary manoeuvres should be performed.
A Pringle manoeuvre needs to be performed (Pringle, 1908 ). This involves
passing a tape around the portal vein, CBD, and hepatic artery below the bifur-
cation and entry of the cystic duct. The tape, when tightened, will occlude both
the hepatic artery and portal vein ( Fig. 3.6 ).
Fig. 3.4 Manual compression of the liver.
109
LIVER TRAUMA
Fig. 3.5 The management of liver trauma.
Liver trauma
Unstable
Stable
Surgery
Becomes
unstable
Remains stable
Manage complications
• Hemorrhage
Reactionary
Secondary
• Biliary
• Vascular
• Sepsis
• Other associated injuries
Uneventful
recovery
Investigate
Peritoneal lavage
US
CT
Laparoscopy
Angiography
• Resuscitate
• ATLS guidelines
• Aggressive fluid
replacement
• NG tube
• Catheter
LIVER
110
If bleeding continues unabated then damage to the hepatic veins and/or the
vena cava can be inferred. At this stage if insufficient facilities or assistance are
available, and packing can control the situation, the abdomen should be closed
and the patient transferred to a more specialized and resourced centre. If ade-
quate visualization of the bleeding point, such as a hepatic vein, can be seen,
either repair or occlusion of the vessel should be attempted ( Fig. 3.7 ).
Fig. 3.7 Careful identification of bleeding points and suture repair of hepatic veins.
Fig. 3.6 The Pringle manoeuvre is applied by encircling the contents of the
hepatoduodenal ligament (portal vein, hepatic artery and bile duct) with a sling
or nylon tape.
RESECTION PRINCIPLES
111
Deeper injuries involving the cava are often impossible to control and require
more sophisticated methods of vascular occlusion. It is relatively straightfor-
ward to gain control of the infrahepatic vena cava while the suprahepatic cava
can be clamped either below the diaphragm or in the chest (see Fig. 3.10 in
‘Mobilization of the liver’ section). If both are clamped and the Pringle
manoeuvre performed, it may be possible to gain sufficient access to suture the
cava or hepatic vein defect. Devitalized liver tissue should be removed if tech-
nically possible but this can wait until the patient is stabilized. Attention should
focus on the injury causing instability and formal resection should not
be attempted until these have been addressed (Moore et al ., 1990 , 1995 ). In
unstable patients, control of the bleeding is the most important consideration
and it is often useful to consider a relook laparotomy to deal with devitalized
liver, check haemostasis, and ensure that there are no other delayed complica-
tions such as bowel ischaemia (Moore et al ., 1990 , 1995 ). Some authors recom-
mend the use of extracorporeal bypass which offers theoretical attractions but
in most cases is impractical and available too late to alter the outcome for the
patient.
Resection principles
Concepts concerning liver resection continue to evolve. Even as recently as
25 years ago, for most patients liver resection was considered by many a dan-
gerous experiment (Chakravorty and Wanebo, 1987 ; Fortner and Blumgart,
2001 ). Since its safety has been established (mortality of around 2%) (Choti
et al ., 2002 ; Kato et al ., 2003 ) and its survival advantage for patients with colo-
rectal metastases demonstrated (40% at 5 years), it has experienced a rapid
increase in popularity with a large number of patients being assessed for and
undergoing hepatic resection (Iwatsuki et al ., 1986 ; Choti et al ., 2002 ). Initial
practice was based around either a left or right hepatectomy; bilobar disease or
greater than three to four deposits being considered inoperable. Over time it
has become apparent that techniques can be developed to manage bilobar
disease and multiple deposits. Combinations of staged procedures, portal vein
embolization, ablation, and local resections have helped greatly to expand the
number of patients suitable for curative resections (Maddern et al ., 1995 ;
Lencioni et al ., 2004 ).
Just as surgeons were beginning to recognize the increased surgical solutions
available to them, the oncologists began to offer chemotherapy that not only
helped control the disease but caused significant shrinkage often to the point
of ‘CT extinction’ (Bismuth et al ., 1996 ; Adam et al ., 2001 ; Quenet et al ., 2004 ).
This ‘downstaging’ rendered tumours close to vital vascular structures resectable
and even more patients could be offered surgical cure. What remains unknown
LIVER
112
is the actual effect on the liver parenchyma of preoperative chemotherapy.
Fatty change undoubtedly occurs in some patients but the impact on hepatic
function is largely unstudied. Some surgeons have found that apparently ade-
quate residual liver mass left at the time of resection following chemotherapy,
has been unable to sustain the patient in the postoperative period (Kooby
et al ., 2003 ; Fernandez et al ., 2005 ).
Patients who survive their resection require ongoing follow-up. Over the last
15 years it has become apparent that while 60% of patients develop recurrent
disease, this can in some be resected with similar 5-year survival outcomes and
comparable mortality to the first resection group (Petrowski et al ., 2002 ). In
consideration of the possibility of re-do surgery and having a better under-
standing of what constitutes an adequate resection margin and the effect of
chemotherapy on hepatic function, hepatobiliary surgeons are moving towards
‘hepatic-preserving resections’. This means that providing margins of ideally
1cm but even as little as 1mm can be achieved (except when tumours abut cava
veins or sheaths), then the minimum amount of liver should be resected. The
advantage of this approach is that liver failure from chemotherapy-damaged
parenchyma is less likely and if recurrence occurs during follow-up a greater
range of surgical options will remain. Surgeons who claim zero mortality rates
with liver resections have almost certainly denied some patients the chance of
cure. Mortality should perhaps be expressed as late death due to liver failure and
other causes. Overall, however, with modern techniques and approaches, oper-
ative mortality should be less than 3% (Choti et al ., 2002 ; Kato et al ., 2003 ).
With a growing appreciation of ‘hepatic-preserving resection’ the focus has
now moved to the resection of metastatic lesions in other organs. Lung metas-
tases (particularly peripheral and in small numbers) have been resected fol-
lowing successful liver resection and several encouraging series have been
published (Miller et al ., 2007 ; Barlow et al ., 2008 ; Treasure, 2008 ;) More
recently, adrenal tumours have been included in the list of extrahepatic disease
that can be removed for colorectal metastases. Treatment of patients with
involved portal vein lymph nodes is now also being suggested as reasonable. It
may be that this aggressive surgical approach, combined with improved chem-
otherapy, will offer long-term palliation or cure to many previously ‘inopera-
ble’ patients. In patients with extrahepatic disease it is important to determine
as accurately as possible the additional sites of deposits and also to demon-
strate that all the additional deposits are at least theoretically resectable
with curative intent. If this is the case, then with the current state of knowledge
it is probably reasonable to offer suitably fit patients resection of adrenal and
periportal lymph nodes at the time of liver resection, and subsequently lung
resection if they have additional pulmonary metastases.