Bang JY, Wilcox CM, Navaneethan U, Hasan MK, Peter S, Christein J, et al. Impact of
disconnected pancreatic duct syndrome on the endoscopic management of pancreatic fluid
collections. Ann Surg 2016. [Epub ahead of print].
This study reports findings of a retrospective evaluation of a database of patients
from two large tertiary care centers in the USA with extensive experience in pancreatic
endotherapy undergoing endoscopic drainage for pancreatic fluid collections (PFCs)
from 2003 to 2015. The patients underwent an initial endoscopic/endoscopic ultrasound-guided
(EUS) drainage, and if the response was deemed inadequate, further intervention in
the form of multi-gate technique, dual modality drainage, or percutaneous necrosectomy
was undertaken for clinical success. The authors report about the presence of disconnected
pancreatic duct syndrome (DPDS) and its implication on outcome vis-à -vis success
of intervention, requirement of hybrid methods or repeated interventions, length of
hospitalization, requirement for surgery, etc. The diagnosis of DPDS was based on
magnetic resonance cholangiopancreatography (MRCP) (eighty patients) or endoscopic
retrograde cholangiopancreatography (ERCP) (180 patients) or EUS-guided pancreatogram
(four patients) findings. Any patient requiring more than six endoscopic procedures
was deemed to have failed treatment. While till 2008 no transmural stents were left,
after 2008, transmural stents were left in situ to allow for the drainage of disconnected
segment of the pancreas.
In a cohort of 361 patients, seventy patients could not be assessed for the presence
of DPDS due to various reasons. Of the rest of 291 patients, 167 patients had DPDS
while 124 had the continuity of the MPD maintained. The patients with DPDS were older
than the other group and had a larger number of male patients with walled-off pancreatic
necrosis (WON)-type collections which were larger or multiple in numbers. The drainage
in DPDS patients was more likely to be trans-duodenal and required placement of a
larger number of stents. These patients also needed enteral feeding tube placement
more frequently because of a poor tolerance to orally administered feeds. Overall,
88% of patients achieved treatment success and these rates were similar in patients
with or without DPDS. However, the presence of DPDS was associated with more requirements
of additional (hybrid) procedures which were needed in one-third of the patients in
contrast to being needed in only 4.8% of patients without DPDS. Endoscopic re-interventions
were needed more frequently in patients who had an underlying DPDS vis-à -vis those
who did not have DPDS (30% and 18.5%, respectively). Moreover, the need for surgical
intervention for rescue of failed endoscopic therapy was also significantly higher
in patients with DPDS as compared to patients without DPDS (13.2 vs. 4.8%, respectively).
The median duration of hospitalization was also longer in the patients with DPDS by
a day (3 vs. 2 days). However, the recurrence of PFCs was not different among the
two groups. However, among the patients with DPDS, the recurrence rates were significantly
lower for patients with permanent indwelling transmural stents. Other than the presence
of DPDS, presence of WON and collections more than 10 cm was also associated with
the need for hybrid procedures. The authors concluded that DPDS significantly impacts
the endoscopic management of PFCs with requirement of more complex and frequent endoscopic
interventions with higher failure rates.
Bang JY, Navaneethan U, Hasan MK, Hawes RH, Varadarajulu S. EUS correlates of disconnected
pancreatic duct syndrome in walled.off necrosis. Endosc Int Open 2016;4:E883.9.
Traditionally, the diagnosis of DPDS is based on ERCP or MRCP findings, demonstrating
the disruption of pancreatic duct. The utility of EUS in this setting is uncertain.
In this prospective observational study, the authors studied the EUS findings in 21
patients with WON who were undergoing EUS-guided drainage. The EUS findings were correlated
with computed tomography (CT), MRCP, or pathological findings on the surgical specimen.
The authors hypothesized that the diagnosis of DPDS can be established while doing
EUS-guided drainage of the WON, thereby precluding the necessity of subsequent ERCP
or MRCP. The diagnosis of DPDS by EUS was suggested by the presence of a well-defined
PFC along the course of the main pancreatic duct and upstream pancreatic parenchyma
and duct terminating into this PFC. The diagnosis of DPDS was confirmed after resolution
of the WON by obtaining pancreatogram by the use of ERCP or EUS.
Of the 42 patients assessed, 21 patients were excluded from the study for various
reasons including the lack of adequate visualization of the pancreatic duct or upstream
gland. Of the included 21 patients, 15 were males, and gallstones and alcohol were
the predominant etiology. Predominantly, the PFCs were located in the body-tail region
of the pancreas. All the 21 patients demonstrated the termination of the upstream
pancreatic parenchyma and the duct into the WON, thereby suggesting the presence of
DPDS.
On follow-up, clinically, 20 patients resolved with endoscopic therapy while one needed
surgical rescue. In these 20 patients, pancreatogram confirmed the presence of complete
ductal disruption. The disruption was also demonstrated after examination of the resected
specimen of the patient who underwent surgery. The authors concluded that there was
100% correlation of EUS findings for the diagnosis of DPDS with follow-up CT, pancreatography
or surgical findings, and early diagnosis of DPDS while doing EUS-guided drainage
which may have significant clinical implications.
Commentary
In recent times, endoscopic or EUS-guided transmural drainage of PFCs has changed
the management strategy of complications related to acute and chronic pancreatitis.
The minimally invasive nature of endoscopic interventions with advantages of lower
cost and shorter duration of hospital stay has decreased the need for surgical intervention.[1] DPDS is a condition which can be seen in patients with acute or chronic pancreatitis
and results from damage to pancreatic duct causing a complete separation of upstream
and downstream parts of the ducts. This results in the separation of a viable part
of pancreatic parenchyma from the downstream duct and thereby the pancreatic secretions
from the upstream part now tend to drain into the pancreatic collections or peritoneum
(ascites) or externally (external pancreatic fistula).[2] The causes of DPDS may include pancreatic trauma, surgery, malignancy, and acute
or chronic pancreatitis.[2] The usual reported site of pancreatic duct disruption is head and neck/body region,
possibly related to the propensity of this region to ischemic damage.[3] Transmural drainage of the PFC/WON, while creating the conduit of drainage of the
pancreatic fluid into the gastrointestinal (GI) lumen, does not treat the pancreatic
duct disruption. If, in the settings of DPDS, the transmural stents are removed, there
are high chances of recurrence of PFCs. Therefore, the currently accepted strategy
is to leave plastic transmural stents indefinitely to maintain the drainage into the
GI lumen.[2],[4],[5] Interestingly, not all patients with DPDS who have been successfully treated with
transmural drainage develop recurrence of PFCs after removal of transmural stents.
In one retrospective report, the occurrence of early stent migration, disruption in
head, absence of endocrine and exocrine dysfunction, or pancreatic atrophy was associated
with the recurrence of PFCs.[6] Furthermore, leaving a single transmural stent was as effective as leaving two transmural
plastic stents for avoiding the recurrence of PFC.[7]
With the advent of endoscopic/EUS-guided metallic stent placement for drainage of
PFCs, it becomes more imperative that presence of DPDS is established.[1],[8] Since metallic stents cannot be left indefinitely, the endoscopist may want to replace
these with plastic stents in patients with DPDS. Therefore, identification of at least
a subset of these patients at the time of EUS-guided drainage may guide further therapy
in such patients. A recently published study has suggested that DPDS can be classified
into three groups: concurrent DPDS where severe necrotizing pancreatitis may disrupt
the pancreatic duct in the early phase, delayed DPDS where the patients with acute
pancreatitis develop a late onset/recognition of disruption, and chronic pancreatitis-related
DPDS which is related to chronic pancreatitis. While the concurrent DPDS may be associated
with complex fluid collection which may form WON, the other two variants are associated
with the formation of pancreatic pseudocysts.[9]
The presence of DPDS identifies those patients who need multiple interventions and
higher surgical intervention. Therefore, these recently reported studies would help
improve the management and prognostication of patients with DPDS. However, the use
of EUS has its limitations. The presence of a nondilated duct may impair visualization
and assessment for the presence of DPDS. In addition, large collections may impair
the correct visualization of MPD-WON relationship. Indeed, half of the patients in
the reported study could not be assessed on EUS for the presence or absence of DPDS.
To conclude, patients with DPDS constitute a more difficult-to-treat subgroup, and
in a subset of patients, the disconnected duct may be identified using EUS.
