Current surgical management of pancreatic cancer
Department of Surgery, Saint Louis University, St. Louis, Missouri, USA
Review Article
Current surgical management of pancreatic cancer
Department of Surgery, Saint Louis University, St. Louis, Missouri, USA
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Abstract
En bloc resection is the treatment of choice for localized pancreatic cancer. While the perioperative mortality associated
with resection is low, it still carries a significant morbidity rate of up to 50% in certain high-risk subsets of patients. With
advances in perioperative care, radical resection with inclusion of adjacent vascular structure to achieve negative margin
status can be performed with comparable mortality and morbidity in high-volume centers. Early results with the use of
minimally invasive technique in pancreatic surgery are promising. Recent data on perioperative care to decrease morbidity
with pancreatic surgery will also be discussed.
Key words
pancreaticodoudenectomy, distal pancreatectomy, laparoscopic pancreatic surgery
J Gastrointest Oncol 2011; 2: 126-135. DOI: 10.3978/j.issn.2078-6891.2011.029
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Introduction
Worldwide, over 200,000 people die annually of pancreatic
cancer. In the United States, pancreatic cancer is the 4th
leading cause of cancer death, and in Europe it is the 6th (1).
Great majority of patients present with locally advanced
or metastatic disease (2). Surgical resection remains the
only potentially curative intervention for select patients
who present with localized disease. In 1912, Walter Kausch
reported the first successful resection of duodenum
and a portion of the pancreas for periampullary tumor
(3). In 1935 Whipple redefined the procedure as a two
stage operation consisting of gastric and biliary bypass
in the first stage followed by pancreaticoduodenectomy
(4,5). In 1978, Traverso and Longmire introduced the
pylorus preserving pancreaticoduodenectomy (6). During
the 1960s, many centers reported operative mortality
following pancreaticoduodenectomy to be 20-40%, with
postoperative morbidity at 40-60% (7). With advances in
surgical techniques and perioperative care, the mortality
rates associated with the procedure has reduced to less than
5%, while morbidity rate approached 40% even in highvolume centers (8-11).
Approximately 15-20% of patients initially diagnosed
with pancreatic caner are amenable to resection (12,13).
Great majority of pancreatic cancer (90%) are ductal in
origin located predominantly in the head (>75%) (14).
Unresectable lesions are those involving SMA or celiac axis
(T4) or those with distant metastases (M1). Controversy
exists regarding the definition of borderline resectable
lesions. Generally, tumor abutment of visceral arteries
or short-segment occlusion of the superior mesenteric
vein is considered anatomically borderline resectable
lesion (15). Recent Consensus Conference sponsored by
Americas HepatoPancreatoBiliary Association, Society for
the Surgery of Alimentary Tract, and Society of Surgical
Oncology provided a more precise definition for clinical
trial design and literature comparison (16) : (i) tumorassociated
deformity of the superior mesenteric vein (SMV)
or portal vein (PV) (Figure 1); (ii) abutment of the SMV
or PV>=1800; (iii) short-segment occlusion of the SMV
or PV amenable to resection and venous reconstruction;
(iv) short-segment involvement of the hepatic artery or its
branches amenable to resection and reconstruction (Figure
2); and (v) abutment of the superior mesenteric artery
(<1800). Outcome following resection is influenced by R0
resection (10,11,17), nodal involvement (10,11), histologic
grade (11,18), elevated CA19-9 levels (18-20), high Body
Mass Index (21), and operative blood loss (17,22).
Operative techniques for head of pancreas cancer
include the standard pancreaticoduodenectomy
(Whipple procedure) and pylorus -preserving
pancreaticoduodenectomy. Extended retroperitoneal
lymphadenectomy and superior mesenteric vein and/or portal vein resection have recently been evaluated
for maximal surgical clearance of disease. The type of
pancreatic anastomosis has also been examined, including
pancreaticojejunostomy versus pancreaticogastrostomy.
Several institutions have repor ted their results for
laparoscopic pancreatic resection with comparable results to
open resection. Various post operative strategies have been
evaluated for reduction of post-operative complication rates,
including the use of octreotide (somatostatin analogue) ,
pancreatic enzyme replacement therapy, erythromycin and
nutritional support. The purpose of this article is to review
the preoperative, operative, and post operative management
strategies in the treatment of pancreatic cancer.
Determination of resectability
Paramount to the decision for performing
pancreaticoduodenectomy is the accurate identification
of patients who have resectable disease. Various imaging
modalities are available to accurately stage a patient
with pancreatic cancer, including CT, PET/CT, ERCP,
endoscopic ultrasound, mesenteric angiography, and
MRCP. CT scan has been the main imaging modality for
determination of resectability. With advances in medical
imaging and improvement in the resolution capability, the
role of diagnostic laparoscopy is now limited in the initial
evaluation of resectability. In a recent study of 298 patients,
Mayo et al reported 87% resection rate in this cohort where
CT was performed in 98% of the study patients, EUS in
32%, and laparoscopy in 29% (23). In the laparoscopy
group, 27% had findings that precluded resection. In
a recent review of their experience at Memorial Sloan-
Kettering Cancer Center, White et al reported an yield of diagnostic laparoscopy of 14% overall, but only with
8% yield in patients with in-house pre-operative imaging
versus 17% with external imaging (24). The same group
proposed a judicious use of diagnostic laparoscopy with
the combination of pre-operative CA19-9 as a stratification
factor to consider laparoscopy in those with resectable
disease on imaging and elevated CA19-9 level (25).
Preoperative Biliary Drainage
Because of the predominant location of pancreatic cancer
in the head of pancreas, obtructive jaundice is a common
presenting symptom. Several cohort studies have been
published regarding the detrimental effect of pre-operative
biliary instrumentation/stenting on the post-operative
course with higher infectious complications in the stented
group (26-31). No difference in survival was observed.
However, others have reported no impact on post-operative
complications with pre-operative biliary drainage (32,33)
In a recent multicenter randomized trial comparing early
surgery versus preoperative biliary drainage followed by
surgery, 202 patients were enrolled. The rates of serious
complications were 39% (37 of 96 patients) in the earlysurgery
group and 74% (75 of 106 patients) in the biliarydrainage
group (P<0.001) (34). A follow-up report from
the same trial showed that there was a significant delay in
time to surgery (1 week versus 5 week). However, the delay
did not influence survival (35). While there is an increase
in overall infectious complications following surgery in the
stented group, the detrimental effect of pre-operative biliary
stenting is likely limited to those with subsequent bacterial
colonization of the biliary tree from stent placement (36).
Jagannath et al found no difference in post-operative complications between the un-complicated pre-operative
stent group compared with unstented group. The adverse
outcome was associated with positive intraoperative bile
culture. Further adding to the controversy of pre-operative
biliary stenting, while high pre-operative bilirubin was
associated with worse survival outcome, resolution of
jaundice following pre-operative biliary stenting appeared
to counter the adverse survival effect of bilirubinemia
(37). Thus, pre-operative biliary drainage should be used
judiciously in symptomatic patients.
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Operative considerations
Pancreaticoduodenectomy
The traditional pancreaticoduodenectomy (PD) consists
of resection of the pancreatic head, duodenum, distal
common bile duct, gallbladder, and gastric antrum (4,5).
A more recent modification of this procedure involves
preservation of the pylorus and gastric antrum, referred
to as the pylorus preserving pancreaticoduodenectomy
(PPPD)(6). Resection is then followed by re-establishing
gastrointestinal continuity. The jejunum is typically used
for each anastomosis, consisting of pancreaticojejunostomy,
hepaticojejunostomy, and gastrojejunostomy or
duodenojejunostomy in the case of PPPD. During the
1960s and 1970s, mortality associated with PD approached
25%. Over the past 3 decades, experience performing PD
has increased with associated decrease in perioperative
mortality rate to less than 5% (38-41). However, it is
still a technically challenging procedure with significant
perioperative morbidity. Cameron reported his personal
series of 1000 PD performed over a span of 34 years with
1% perioperative mortality (41). Perioperative morbidity
was observed in 41% of the cohort including delayed
gastric emptying (18%), pancreatic fistula (12%), wound
infection (7%), intra-abdominal abscess (6%), cardiac event
(3%), pancreatitis (2%), bile leak (2%), pneumonia (2%),
hemobilia (2%), and reoperation in 2.7%. To minimize postoperative
morbidity, various strategies for reconstruction
have been under intense investigation. The predominant
controversy regarding standard PD versus PPPD or
pancreaticojejunostomy versus pancreaticogastrostomy
reconstruction has been extensively studied (42-44). No significant superiority of one variant of PD over another has
been convincingly demonstrated. Surgeon's experience with
the specific variant of PD appeared to be the determining
factor in achieving optimal surgical outcome.
Distal pancreatectomy
Distal pancreatectomy is the standard procedure for cancer
of the body or tail of pancreas. It entails the resection of distal portion of pancreas extending from the left of the
superior mesenteric vein/portal vein axis to the tail with
en bloc resection of surrounding lymphatic tissue. Spleen
is conventionally removed with the procedure. Spleensparing
distal pancreatectomy (Warshaw operation) can
be performed safely without increase in complication rate,
operative time or in-hospital stay (45). While cancer of the
body and tail tends to present at an advanced stage due to
the lack of early symptoms and tends not to be amenable
to complete resection on presentation, there is no survival
difference when compared with cancer of the head of
pancreas stage by stage (46,47).
Laparoscopic pancreatic resection
With the publication of COST trial, minimally invasive
surgical approach has been evaluated in increasing
frequency for cancer resection (48). For the surgical
management of pancreatic neoplasm, laparoscopic distal
pancreatectomy (LDP) is rapidly becoming the surgical
procedure of choice in place of open distal pancreatectomy
(ODP) for tumor of the body/tail of pancreas. While several
groups have published their results with LDP, the majority
of the publication did not specifically address the oncologic
outcome following LDP for pancreatic cancer (49-59).
Overall, when compared with ODP, LDP is associated with
a longer operative time, less blood loss, and shorter length
of stay. Conversion rate from laparoscopic approach to open
varies between 0 to 30%. In their institutional experience,
Baker et al noted a lower number of lymph nodes harvested
in 27 LDP patients (mean=5) compared with 85 ODP
patients (mean=9) (57). Kooby et al performed a matched
analysis of 23 LDP patients with 189 ODP patients from a
database with pooled data from 9 academic centers (58).
There was no difference in positive margin rates, number
of lymph nodes examined, or overall survival in patients
with pancreatic cancer. Jayaraman et al reviewed their
results of 343 distal pancreatectomies over a 7-year study
period at Memorial Sloan-Kettering Cancer Center : 107
were attempted laparoscopically and 236 ODP (59). The
conversion rate was 30%. Similar complication rates were
observed in both groups. They also observed significantly
less blood loss, longer operative times, and shorter hospital
stays in favor of LDP group. The number of lymph nodes
examined (LDP = 7 vs. ODP = 7) and margin positivity
(LDP = 3% vs ODP = 4%) were similar between both
groups. They
observed a higher conversion rate in patients
with larger tumor, higher BMI, and tumor proximity to
celiac axis. No survival data were provided. Based on these
data, LDP appeared to be an appropriate oncologic surgical
approach in select patients with cancer of the body/tail of
pancreas.
Laparoscopic pancreaticoduodenectomy (LPD) was first
described by Gagner and Pomp in 1994 (60). Due to the
complexity of the operation and lack of apparent advantages,
reports regarding LPD contained case reports and small
series. Series containing 10 or more successful LPD are
listed in Table 1. While these reports demonstrated the
safety and feasibility of performing LPD, larger prospective
trials are needed to further define the advantage, if any, of
LPD.
Role of extended retroperitoneal lymphadenectomy
Nodal status is a significant prognostic variable in
pancreatic cancer. The number of nodes involved with
metastases, the ratio of lymph node involvement, and
the minimum number of lymph nodes examined had
all been shown to have prognostic significance (67-69).
Because of the importance of nodal staging, extended
lymphadenectomy (EL) during pancreaticoduodenectomy
was proposed to improve the surgical outcome of
pancreatic cancer patients. The definition of EL is not
uni form. Commonly EL refer red to the dissect ion
of additional lymph nodes along the aorta from the
diaphragmatic hiatus to the inferior mesenteric artery and
laterally to the renal hila with circumferential clearance
of the celiac trunk (70). While several groups from Japan
had reported favorable outcome following EL during
pancreaticoduodenectomy (71-73), multiple randomized
trials had not demonstrated an improvement in overall
survival following EL (70,74-76). Yeo et al also observed a
significantly higher complication rate associated with the
radical surgery group (43%) compared with the standard
pancreaticoduodenectomy group (29%) (74). Higher rates
of delayed gastric emptying and pancreatic fistula and
longer hospital stay were observed in the radical surgery
group. The higher morbidity associated with EL was also
reported in a meta-analysis on standard versus radical
pancreaticoduodenectomy (77). The authors also did not
find a difference in survival between the standard versus radical pancreaticoduodenectomy.
Portal vein and superior mesenteric vein resection
Because achieving an R0 resection had prognostic
significance for patient outcome, vascular resection during
PD had been evaluated. The great majority of vascular
resection during PD involved portal vein and superior
mesenteric vein resection and reconstruction. Yekebes et al
reported equivalent perioperative morbidity and mortality
between the standard PD group and the group with vascular
resection (78). The median survival was 15 months in
patients with histopathologic proven vascular invasion
and 16 months in those without (P=0.86). Riedeger and
colleagues also reported similar results with regard to
portal vein/superior mesenteric vein resection (79). In their
study cohort of 222 pancreaticoduodenectomy patients,
53 required portal vein and/or superior mesenteric vein
resection while 169 did not. There was no significant
difference in morbidity or mortality between the two
groups. Kanoeka and colleagues demonstrated that the
length of portal vein / superior mesenteric vein (PV/SMV)
resected had an inverse correlation with survival (80).
PV/SMV resections that are < 3 cm were associated with a 5-year survival rate of 39% vs. 4% for resections that are >=3 cm in length (P=0.017). Chua and Saxena performed a systematic review of published reports on extended
pancreaticoduodenectomy with vascular resection (81).
Twenty-eight retrospective studies were included in
the review comprising of 1458 patients. The median R0
resection rate was 75% (range, 14%-100%). The median
mortality rate was 4% (range, 0-17%). Based on the reports
from high-volume centers (>20 pancreaticoduodenectomy/year), the median survival associated with extended
pancreaticoduodenectomy with vascular resection was
15 months (range, 9-23 months). Therefore, in select
patient where R0 resection can be achieved, PV/SMV
resection/reconstruction can be performed with
comparable morbidity and survival outcome to standard pancreaticoduodenectomy.
Post operative considerations
While the perioperative mortality for
pancreaticoduodenectomy has dropped to 5% in recent
times due to advances in surgical techniques, the morbidity
rate remains high at 40%. Pancreatic fistula remains the
most serious complication after pancreaticoduodenectomy
and occurs in up to 20% of patients. Other major
complications include delayed gastric emptying and
hemorrhage. In an effort to identify independent risk
factors for post operative morbidity, Adam and colleagues
prospectively studied 301 patients who underwent
pancreatic head resections (82). Three pre-operative
risk factors were found to independently correlate with
increased complication rate: presence of portal vein/splenic
vein thrombosis or hypertension, elevated pre-operative
creatinine, and the absence of pre-operative biliary
drainage. In contrast, other studies (including a prospective
randomized controlled trial) have reported a statistically significantly higher complication rate for patients undergoing
pre-operative biliary drainage (26-31,34). Patients
undergoing operation after 1998 were also noted to have
fewer complications, suggesting that increased experience
and improved patient selection has led to improvement
in perioperative care. The requirement for resection of
additional organs also correlated with a higher complication
rate.
Patient's age and its impact on morbidity, mortality,
and survival have been intensely investigated (83-87). The majority of studies used age 70 or 80 as the cutoff. In
their systematic review of literature, Riall et al found that
higher morbidity and/or mortality was observed in the
elderly population (87). Makary et al reviewed their single
institutional experience with 2,698 patients undergoing
pancreaticoduodenectomy over a 35 year period (83). When
compared to the younger group (<80), patients in the 80-89
group had statistically significant higher morbidity and
mortality rates (p<0.05). Haigh et al identified 2610 patients
undergoing pancreaticoduodenectomy from 1/2005
through 12/2007 in the American College of Surgeons-
National Surgical Quality Improvement Program database
(88). Elderly patients (>70 years old) had a higher likelihood
of developing at least 1 morbidity compared with that of
younger patients (40.7% vs 34.0%; P = .01). Furthermore,
elderly patients had a higher perioperative mortality rate
compared with that of younger patients (4.3% vs 1.7%;
P = .01).
The efficacy of octreotide, a somatostatin analogoue,
in decreasing complication associated with pancreatic
resection is controversial. The rationale for using octreotide is that it can decrease pancreatic enzyme secretion
thereby decreasing the rate of pancreatic fistula formation
(89). Multiple randomized multicenter trials comparing
octreotide or vaprotide, another somatostatin analogue, to
placebo in patients undergoing pancreatic resection have
been performed (89-97). The use of somatostatin analogues
did not impact mortality in patients undergoing pancreatic
resection. While some studies demonstrated a statistically significantly decrease in the development of pancreatic leak/stula with the use of somatostatin analogue, others showed
no difference.
Delayed gastric emptying is another leading cause of
morbidity in patients undergoing pancreaticoduodenectomy
(98). The occurrence of delayed gastric emptying resulted
in prolonged nasogastric tube decompression, initiation
of enteral or parenteral nutrition, and prolonged hospital
stay. The pathogenesis of delayed gastric emptying has
been attributed to decrease gastric motility secondary
to decreased levels of motilin (99). Motilin induces
contractions of intestinal smooth muscles, initiates phase
III of the gastric migrating motor complex, and improves
gastric emptying in patients with diabetic gastroparesis
(100,101). Yeo and colleagues performed a prospective
randomized trial evaluating the effects of erythromycin
on delayed gastric emptying in patients undergoing
pancreaticoduodenectomy, randomizing 118 patients to
erythromycin lactobionate 200 mg every 6 hours or saline. The erythromycin group had reduced incidence of delayed
gastric emptying (19% vs. 30%), need for nasogastric tube
re-insertion (6 vs 15 patients, p<0.05), and retention of
liquids and solids on radionucleotide gastric emptying
study (p<0.01) (102). Thus, the use of erythromycin can
reduce the occurrence of delayed gastric emptying after
pancreaticoduodenectomy.
Patients with pancreatic cancer who are deemed
candidates for curative resection are frequently
malnourished pre-operatively (103,104). Serum albumin
level is a significant prognostic indicator of post operative
mortality. Winter and colleagues categorized patients
into 3 groups based on pre-operative serum albumin level
(>3.5, 2.6-3.5, <2.6). Post operative mortality was 7%
in the group with lowest serum albumin level compared
with 3% for the intermediate group, and 0.9% for the
>3.5 group (105). Okabayashi and colleagues evaluated
the benef it of early post operative enteral nutrition
(EPEN) vs. late post operative enteral nutrition (LPEN)
in pat ients undergoing pancreat icoduodenectomy
(106). Twenty-three patients received TPN followed
by the initiation of oral intake during the late post
operative period (LPEN group). Sixteen patients were
initiated on enteral feeds via jejunostomy tube on post-operative day 1 (EPEN group). The EPEN group had
significantly lower rate of post-operative pancreatic
fistula and shorter length of hospital stay. Brennan and
colleagues performed a prospective randomized trial
in patients undergoing major pancreatic resection,
comparing patients receiving parenteral nutrition with
patients who did not (107). They found that the group
receiving parenteral nutrition had significantly higher
complication rate with increased rate of intra-abdominal
infection and longer duration of hospitalizaion.
Continuous infusion of nutrients has been demonstrated
to cause a delay in gastric emptying. Elevated levels of
cholecystokinin (CCK) is a known cause of delayed gastric
emptying (108,109). Van Berge Henegouwen and others
performed a prospective randomized study comparing
continuous (CON) feeding protocol (1500 kCal/24hrs)
with cyclic (CYC) feeding protocol (1125 kCal/18hr)
(110). They found that patients in the CYC group were able
to tolerate a normal diet sooner than the CON group. The
length of hospital stay was shorter in the CYC group. Levels
of CCK were lower in the CYC group, suggesting that
lower levels of CCK plays a role in reducing delayed gastric
emptying.
Enteral nutrition formulas containing immunomodulating
agents (arginine, RNA, Omega-3 fatty acids) have been
investigated in patients undergoing cancer surgery. Braga
and colleagues performed a prospective randomized double
blind clinical trial comparing standard enteral feeds with
enteral feeds enriched with arginine, RNA, and Omega-3
fatty acids post operatively in patients undergoing curative
resection for neoplasms of the colorectum, stomach, or
pancreas (111). Patients receiving immunomodulating
agents had a statistically significant decrease in post
operative infection rate and length of post operative
stay. The use of probiotics has been shown to stabilize
the intestinal barrier, increase intestinal motility, and
enhance the innate immune system. Rayes and colleagues
performed a randomized double blind study in 80 patients
undergoing pylorus preserving pancreaticoduodenectomy.
One group received early post-operative enteral feeds with
lactobacillus, and the other group received placebo (112). The incidence of post operative infections was significantly
lower in the group receiving lactobacillus compared with
placebo group(12.5% vs. 40% p=0.005).
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Conclusion
While resection of pancreatic cancer can be performed with
low perioperative mortality, the associated perioperative
morbidity can be significant. Recent advances in surgical
instrumentation have made wide spread adoption of laparoscopic distal pancreatectomy possible. Similar to
experience in other cancer types, the initial oncologic
outcome with laparoscopic distal pancreatectomy appear
comparable to open distal pancreatectomy. The advantage
of minimally invasive surgery in terms of less blood loss
and shorter hospital stay was also observed. The advances
in surgical techniques also allow more aggressive surgical
resection to be performed with acceptable perioperative
mortality and morbidity. With the advances in systemic
treatment of pancreatic cancer, the ability to achieve
negative resection margin will improve the outcome of
patients with this aggressive disease.
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References
Cite this article as:
Kim C, Ahmed S, Hsueh E. Current surgical management of pancreatic cancer. J Gastrointest Oncol. 2011;2(3):126-135. DOI:10.3978/j.issn.2078-6891.2011.029
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