Download Replaced Common Hepatic Artery From Superior Mesenteric Artery

Replaced Common Hepatic Artery From Superior
Mesenteric Artery During Pancreaticoduodenectomy
M. Wood, C. Lazo, V. Hassid, Z.T. Awad
Department of Surgery, University of Florida College of Medicine, Jacksonville, USA
Abstract
dissected and preserved as it passed dorsal to
the pancreas. Preservation of the blood supply
to the liver and biliary tree is important after PD
to prevent biliary fistula and hepatic ischaemia.
The hepatic arterial anatomy is highly
variable. A 67 year female with pancreatic
mass and replaced common hepatic artery
originating from the superior mesenteric artery
underwent pancreaticoduodenectomy (PD).
The anomalous vessel was discovered on
preoperative CT scan and MRI. The vessel was
Keywords
Replaced
common
hepatic
Pancreaticoduodenectomy, Whipple
Introduction
artery,
that time that the CHA originated from the SMA
(Fig. 1). CT pancreas protocol confirmed the MRI
finding. The patient underwent an exploratory
laparotomy and PD. Intra-operatively, the CHA
was identified to the left of the common bile
duct, and it was carefully dissected downstream
where it gave origin to the gastroduodenal artery
(GDA) at the upper border of the gland before
coursing dorsal to the neck of the pancreas. The
common bile duct was divided, and its distal end
was retracted caudally to expose the portal vein.
The pancreatic neck tunnel was created and the
pancreas was transected exposing the RCHA
which was anterior to the portal vein – superior
mesenteric vein (SMV) confluence before it
courses behind the SMV to its origin from the
SMA (Fig. 2). The patient postoperative course
was unremarkable and was discharged home
on 12. Pathology was consistent with chronic
pancreatitis.
The hepatic arterial anatomy is anomalous
in nearly 50% of all individuals(1). The most
common anomalies include the right hepatic
artery arising from the superior mesenteric artery
and the left hepatic artery arising from the left
gastric artery. The incidence of the replaced
common hepatic artery (RCHA) originating
from the superior mesenteric artery (SMA) has
been estimated to be 1.5% - 4.0%(2).
Pancreatoduodenectomy (PD) is the standard
operative procedure for periampullary cancer
and other pancreatic diseases. When planning
for PD, knowledge of the hepatic arterial blood
supply is essential to avoid unnecessary surgical
complications, and this can best be achieved
by preoperative imaging evaluation of the
vasculature.
Case Report
A 67 year-old woman presented with few
weeks history of epigastric pain and weight
loss. EGD showed duodenal stenosis, MRI
of the abdomen revealed a three-centimeter
discrete pancreatic mass. Also, it was noted at
Discussion
Understanding the variant patterns in anatomy
around the porta hepatis can aid in preventing
injury to ducts and blood vessels during surgery.
The importance of sparing the CHA during PD
lies in preventing possible hepatic ischemia
as well as in preventing breakdown of biliaryenteric anastomosis(3).
Correspondence: Ziad T. Awad, M.D, FRCSI, FACS,
Assistant Professor of Surgery, Director of Minimally
Invasive Surgery, University of Florida College of
Medicine Jacksonville, 653 West 8th Street, 3rd
Floor Faculty Clinic, Jacksonville, FL 32209, USA,
Phone: 001 904 244 3971 Fax: 001 904 244 3870,
Email: [email protected]
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Historically, visceral angiography was used
for preoperative evaluation of patients with
pancreatic neoplasrns, and was felt to provide
G. J. O. Issue 11, 2012
useful information in regard to tumor staging
(extension to portal vein and SMA) as well as the
presence of anomalous hepatic arterial vessels(4).
Among the multiple modalities that exist, there
is no single gold standard staging approach
adopted by all. However, multidetector CT
allows comprehensive preoperative assessment
of pancreatic adenocarcinoma. Carefully timed
scan acquisition maximizes the difference
in attenuation between the neoplasm and the
pancreatic parenchyma and allows accurate local
and distant staging as well as assessment of local
resectability. In addition, angiographic data sets
can be rendered to create displays of the local
venous and arterial anatomy that are familiar to
surgeons(5-6).
If a RCHA is known preoperatively, one
should delay ligation of the GDA until the
retropancreatic dissection (through the posterior
approach) and proper identification of the RCHA
is completed. This is followed by division of the
pancreatic neck over the RCHA and proximal
SMA rather than the superior mesenteric veinportal vein confluence. Yamamoto et al. have
described five different methods for dealing with
a RCHA, which can also be applied to a replaced
right hepatic artery (RRHA)(7). A RCHA that
courses through the pancreatic parenchyma can
be preserved by dividing the pancreas. With this
strategy, there is a risk of not achieving tumorfree margins because the division line of the
pancreas is likely to be lateral or to the right
of the standard pancreatic division line. Often,
a RCHA or RRHA that courses ventral to the
pancreas can be displaced and dissected from
the surface of the pancreatic parenchyma and a
standard PD can be performed. When a RCHA
is known to have an anastomotic connection to
the LGA or another accessory artery, ligation
resulted in no compromise to the arterial blood
supply of the liver or extrahepatic biliary tree.
A fourth approach involves division of the
RCHA or RRHA and reconstruction using an
autologous vascular graft such as the GDA or
saphenous vein. We advocate direct anastomosis
to the aorta with construction and caution that
anastomosis to the SMA should be avoided due
to technical difficulties and the risk of mesenteric
ischemia. Finally, the surgeon should remember
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that a pylorus-preserving PD, which preserves
the right gastric artery can often be performed
with subsequent division of the RCHA if
collateral communication to the RCHA has been
demonstrated preoperatively.
Surgeons should have knowledge of the
anatomical vasculature variations when planning
PD. Preoperative imaging studies can aid and
should be performed in anticipation of the
potential vascular variations during PD.
Fig. 1 : CT pancreas protocol reconstruction of the
CHA originating from the SMA.
Fig. 2 : Intra-operative photograph of the CHA
dissected from its origin at the SMA.
Replaced Common Hepatic Artery, M. Wood, et. al.
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