A case report of Pancreatico Pleural Fistula presenting as recurrent right pleural effusion

Pancreaticopleural Fistula (PPF) is a rare complication seen approximately in 0.4% of patients with chronic pancreatitis. There occurs an abnormal communication, known as fi stula, between the pancreatic duct and the pleural space, due to the leakage or rupture of a pancreatic pseudocyst or disruption of pancreatic Duct (PD). The drainage of pancreatic secretions into the pleura causes amylase rich pleural effusion subsequently in these patients [1]. In comparison to the pleural effusions seen in pancreatitis that are clinically insignifi cant, a PPF produces recurrent, large volume effusions. Owing to its low incidence, it is rarely considered as a cause of pleural effusion.


Introduction
Pancreaticopleural Fistula (PPF) is a rare complication seen approximately in 0.4% of patients with chronic pancreatitis. There occurs an abnormal communication, known as fi stula, between the pancreatic duct and the pleural space, due to the leakage or rupture of a pancreatic pseudocyst or disruption of pancreatic Duct (PD). The drainage of pancreatic secretions into the pleura causes amylase rich pleural effusion subsequently in these patients [1]. In comparison to the pleural effusions seen in pancreatitis that are clinically insignifi cant, a PPF produces recurrent, large volume effusions. Owing to its low incidence, it is rarely considered as a cause of pleural effusion.
Patients present with typical symptoms which are mainly pulmonary, rather than abdominal, leading to delayed diagnosis. The presenting fi ndings being large, recurrent pleural effusion in majority of the cases [2].
The diagnosis in such cases is diffi cult, but the clinical fi ndings aided with amylase-rich pleural fl uids and demonstration of fi stula tract on imaging like Computed Tomography (CT) or Magnetic Resonance Cholangiopancreatography (MRCP) helps to establish the cause. CT is an easily accessible method and shows both the thoracic and abdominal fi ndings non-invasively. It is useful for imaging fi ndings of chronic pancreatitis and can clarify the site of fi stulisation and give details of anatomical relations of the fi stula with other organs [3].
We present a case of a 37-years-old male patient suffering from chronic alcoholism, who presented with a recurrent right pleural effusion due to a PPF, diagnosed by clinical fi ndings, pleural fl uid analysis and imaging, and who was subsequently managed with conservative medical management.

Discussion
Pancreaticopleural Fistula (PPF) formation is rare, occurs in about 1% patients with acute pancreatitis and in 0.4% patients with chronic pancreatitis [1]. It is an abnormal collection   of pancreatic secretions contained within a non-epithelial wall, primarily composed of granular and fi brous tissue [4]. The various etiologies for its formation include: alcoholrelated chronic pancreatitis (leading cause), pancreatitis due to gallstones, idiopathic pancreatitis, trauma or congenital pancreatic duct anomalies [5]. PPF formation due to the rupture of posterior pancreatic pseudocyst causes the pancreatic secretions to ascend to the pleural space due to abnormal connection of the pancreatic duct to the pleural space. These cases of PPF-related pleural effusion have to be differentiated from the reactive pleural effusion occurring with pancreatitis, which usually is left-sided and self-limiting; however, right and bilateral effusions can also occur [6].
The typical presentation of PPF is a middle-aged male, with chronic pancreatitis secondary to alcoholism. Patient presents with recurrent pleural effusion, which rapidly reaccumulates and is resistant to thoracentesis. In such cases, pleural effusion is more common on left side (42%-67%), though it can also be right sided (19%-40%) or bilateral (14%-17%). Patient reports with pulmonary symptoms, shortness of breath being the most common presenting complaint in 65%-76% and abdominal symptoms reported in 24% of these cases [7,8].
History and physical examination are non-specifi c for PPF and thus, further evaluation with imaging and laboratory work-up is needed. The establishment of diagnosis is via thoracocentesis with subsequent pleural fl uid analysis demonstrating exudative effusion with signifi cantly elevated amylase levels [1]. In the cases with moderately elevated amylase levels, imaging fi ndings are helpful in diagnosis. Following this, the next step is confi rmation of the presence of the fi stula, for which most sensitive imaging modality is MRCP, followed by Endoscopic Retrograde Cholangiopancreatography (ERCP) and CT scan [9]. CT has the advantage of being noninvasive and the capability of providing three-dimensional images. In this case, CECT chest and abdomen was performed which revealed the chronic pancreatitis changes (parenchymal changes, dilatation of the duct and fl uid collection), along with abnormal duct communication with the collection suggestive of PPF.
The treatment of PPF requires multidisciplinary approach, comprising of pulmonary, gastroenterology and general surgery teams. Management options can be medical, endoscopic, or surgical depending on the individual case [10]. Endoscopic management with ERCP stenting to the pancreatic duct is a successful option. If no strictures are found in the pancreatic duct on MRCP, such patients can be managed medically. Surgical management is the last resort when medical and ERCP treatment fails. In the case discussed above, patient was managed medically with octreotide to reduce pancreatic secretions accompanied by total parenteral nutrition and drainage of pleural effusion in that period. The patient improved clinically though the course of the medical management.

Conclusion
Pancreaticopleural Fistula (PPF) is a serious complication of acute or chronic pancreatitis. The diagnosis of PPF requires a high index of suspicion along with a compatible clinical picture.
Demonstration of pleural fl uid rich in amylase is the key diagnostic indicator aided with the radiological demonstration of the fi stula. Multidisciplinary approach is needed for case dependent management, which can be medical, endoscopic or surgical.

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