Author: Meagan Evangelista, MD Candidate, Class of 2017; Editor: Danielle Walsh, MD
Introduction
While a pancreatic injury and illness are rare in the pediatric population, episodes of pancreatitis predispose to the development of a pseudocyst. Pseudocysts distinctly lack an epithelial lining, separating them from true cysts.1 Due to the rarity of pediatric pancreatic pseudocysts, there are still different opinions on optimal management. Additionally, advances in minimally invasive techniques have altered the management. The two most common etiologies of pancreatic pseudocysts in the pediatric population remain acute pancreatitis and blunt abdominal trauma.2 Traumatic injury causes over sixty percent of pancreatic pseudocyst formation and the majority are a result of abdominal impact with the handlebars of bicycles, followed secondly by falls.3 A smaller percentage of pediatric pancreatic pseudocysts are idiopathic and may be related to ductal anomalies such as pancreatic divisum.4,5 Formation of a pancreatic pseudocyst evolves over several weeks following ductal injury or obstruction. The mechanism is pancreatic duct obstruction during injury, inflammation or anatomic anomaly. Clinical manifestations include upper abdominal pain, tenderness, emesis and sometimes an epigastric mass. Pancreatic ascites or a pancreatic pleural effusion are rare.6 Other potential complications include infection, bleeding and pseudoaneurysm formation.1
Diagnosis
Pediatric pancreatic pseudocysts can be suggested by elevated serum amylase but are confirmed in imaging studies. Following pancreatic trauma, a maximum serum amylase >1100 U/L is predictive of pseudocyst development or another complication and may warrant closer radiographic follow-up.7 Due to the absence of radiation, ultrasound is the tool of choice for imaging pediatric pancreatic pseudocysts. However, contrast enhanced CT scans is the standard for diagnosis of traumatic pancreatic injury and is often used for planning surgical intervention. On ultrasound images, pseudocysts are usually well defined, smooth-walled, anechoic or hypoechoic masses. Some are multiocular with internal septations. If hemorrhage or infection is present, internal echoes or a fluid-fluid level may be seen. On CT, the capsule of the pseudocyst should appear well defined with a central area of low attenuation and an attenuation coefficient within a range relative to that of water.5, 8 Endoscopic retrograde cholangiopancreatography and magnetic resonance cholangiopancreatography can be used as adjuncts to evaluate injury to the main pancreatic duct.9, 10
Conservative Management
Not all pancreatic pseudocysts in children require surgical treatment. Pseudocysts measuring less than five centimeters can sometimes resolve nonoperatively. Medical therapies can reduce pancreatic stimulation and promote spontaneous resolution of the pseudocyst.11, 12 Treatment options include: bowel rest with total parenteral nutrition, post-pancreatic tube feedings, and octreotide acetate.13, 14 In a review of pediatric pancreatic pseudocysts resulting from blunt abdominal trauma, six of ten patients recovered using total parenteral nutrition. The authors indicate in these cases all pseudocysts were diagnosed early via ultrasound and promptly treated with gut rest.15
Procedures: Introduction
There are multiple techniques used in the drainage of pediatric pancreatic pseudocysts. Internal and external drainage through surgery, endoscopy and interventional radiology have been described. Open internal drainage is longstandingly the treatment of choice and is still done to a great extent today. However, improved minimally invasive techniques are growing in popularity. With imaging advancements, endoscopic internal drainage was developed and has been used in the pediatric population since the 1996.12 Within the past decade literature has shown pediatric pancreatic pseudocyst cases where laparoscopic internal drainage was a successful new minimally invasive approach to treatment.2, 17, 18, 19
Open Internal Drainage
Prior to imaging advances and minimally invasive techniques, treatment of large, persistent pediatric pancreatic pseudocysts was done as an open cystogastrostomy, cystoduodenostomy or cystojejunostomy, based on the location of the pseudocyst. Cystogastrostomy is the most common procedure and is accomplished with an anterior gastrotomy, palpation and aspiration to confirm pseudocyst location and either a hand sewn or stapled anastomosis in the posterior stomach. Cystojejunostomy can be completed by direct anastomosis or by the Roux-en-Y loop.20 The most common complications are anastomotic bleeding and premature closure.
Laparoscopic Internal Drainage
Laparoscopic cystogastrostomy for the treatment of pancreatic pseudocysts in the pediatric population has been done for nearly a decade.2 A transumbilical gastroscope allows visualization of the anterior gastric wall. Following this two trocars are inserted through the abdominal wall and into the gastric lumen. An endoscope can be used for intragastric visualization. Alternatively, a third trocar with a laparoscope may be utilized. After confirmation of pseudocyst location through aspiration, cautery is used to enter the pseudocyst. Either a hand sewn or stapled anastomosis may be performed. Laparoscopic cystojejunostomy is another minimally invasive treatment option.17 Laparoscopic drainage of pediatric pancreatic pseudocysts is proving to be a beneficial minimally invasive procedure providing definitive drainage. The postoperative recovery time is significantly shorter than other treatment options, a notable benefit.2, 17, 19
Endoscopic Internal Drainage
The first case of pediatric pancreatic pseudocyst endoscopic drainage was reported by Wiersema and associates in 1996.16 There are two approaches to endoscopic drainage of pancreatic pseudocysts, transmural drainage or transpapillary drainage. Transmural drainage is indicated if the pseudocyst is in direct opposition to the stomach or duodenum. The pseudocyst must visibly bulge into the gastric or duodenal wall.21 Transpapillary drainage is indicated if endoscopic retrograde cholangiopancreatography shows pseudocyst connection with the main pancreatic duct and internal stenting is technically feasible.22
Endoscopic transmural drainage is accomplished with a flexible endoscope and a diathermy needle knife to puncture the pseudocyst through the posterior wall of the stomach. Over guidewire dilation enlarges communication between the stomach and the pseudocyst. Both double J stents and double pigtail stents are used to maintain patency while the pseudocyst resolves.21, 23 Internal endoscopic drainage is quickly becoming the procedure of choice for the treatment of pediatric pancreatic pseudocysts. There are associated complications with internal endoscopic drainage. Bleeding, infection leading to abscess formation, stent dysfunction and pseudocyst recurrence are the main concerns. Most stents remain in place for three to eight weeks before endoscopic removal.
Percutaneous External Drainage
Percutaneous external drainage in a child with a traumatic pancreatic pseudocyst was initially reported by Windle et al in 1983.24 It is indicated in patients with thin walled or immature pseudocysts at risk of rupturing. Patients with infected cysts or who are too ill for more definitive treatment can also be treated with this approach.20 With ultrasound guidance and a Seldinger technique, a pigtail catheter can be left in place.25 The technique is often successful in children with normal underlying pancreatic ductal anatomy. Failure of this technique has been noted and is thought to be linked to inadequate direct catheter obstruction or persistent ductal drainage.26 Additionally, drainage catheters often have to remain in place for close to thirty days resulting in lengthy treatment periods. Patients risk inadequate drainage and luminal obstruction of the catheter if the fluid is viscous.
Outcomes
Saad et al in 2005 describe two pediatric cases in which pancreatic pseudocysts were treated with laparoscopic cystogastrostomy. The etiologies of the pancreatic pseudocyst were blunt trauma in one patient and idiopathic pancreatitis in the other. The first patient started on a clear liquid diet postoperative day two which advanced to a low-fat diet. The second patient tolerated a low-fat diet on postoperative day four. Both patients were discharged on postoperative day four. Two years had passed for both with no complications.2 A second report of laparoscopic cystogastrostomy was described in 2008 by Makris et al. In this case, the patient presented with a large pancreatic pseudocyst secondary to acute pancreatitis. The patient began oral nutrition on postoperative day two and was released on postoperative day five. Nine months had passed with no complications.19
Seitz et al describe a case of a pediatric patient with two large communicating pseudocysts of traumatic etiology in the tail of the pancreas. This patient underwent laparoscopic cystojejunostomy. The patient received parenteral nutrition for the first four postoperative days, with oral nutrition starting on day five. The patient was discharged on postoperative day nine. Two years had passed with no complications.17
A 2009, five institution review of laparoscopic treatment of pediatric pancreatic pseudocysts showed ninety two percent resulted in no complications, and required no further operative intervention. Eight percent, one patient, had recurrence of the pseudocyst and required a distal pancreatectomy, following which the patient recovered.18 Overall, laparoscopic techniques have proven to be successful with early oral nutrition and short postoperative hospital stays.
Summary
While nonoperative management may allow some pseudocysts to resolve, minimally invasive techniques should be considered and are technically feasible. Laparoscopic and endoscopic approaches may be particularly efficacious in patients with communicating pseudocysts, pseudocysts in an atypical position and pseudocysts that extend through the diaphragm and into the mediastinum.2, 17 These minimally invasive techniques have been shown to effectively drain the pseudocyst and reduce postoperative hospital time. Reoccurrence is rare.18 Common complications such as infection have not been seen. Catheter obstruction, commonly seen in percutaneous drainage, is not a concern. Additionally, patients undergoing percutaneous drainage often remain in the hospital for several weeks compared to the four to nine days for laparoscopic approaches. Finally, in comparison to open drainage procedures, the recovery time in open procedures is significantly longer, and there is an increased risk of infection.2 Taken as a whole, laparoscopic and endoscopic approaches are advancing as the management strategy of choice for pediatric pancreatic pseudocysts.
References
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- Saad, Daniel F; Gow, Kenneth W; Cabbabe, Samer; Heiss, Kurt F; Wulkan, Mark L. Laparoscopic cystogastrostomy for the treatment of pancreatic pseudocysts in children. Journal of Pediatric Surgery 2005;40:E13-E17.
- Ford, EG; Hardin Jr., WD; Mahour, GH; Woolley, MM. Pseudocysts of the pancreas in children. The American Surgeon 1990;56(6):384-387.
- Buntain, WL; Wood, JB; Woolley, MM. Pancreatitis in childhood. Journal of Pediatric Surgery 1978;13:143-149.
- Nijs, Els; Callahan, Michael J; Taylor, George A. Disorders of the pediatric pancreas: imaging features. Pediatric Radiology 2005;35:358-373.
- Ahearne, Paul M. Pancreatic Pseudocysts. In: Sabiston Jr., David C; Lyerly, H Kim. Sabiston Essentials of Surgery (2nd Edition, 419-422). Philadelphia, PA: W.B. Saunders Company.
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- Houben, CH; Ade-Ajayi, Niyi; Patel, S; Kane, P; Karani, J; Devlin, J; Harrison, P; Davenport, M. Traumatic pancreatic duct injury in children: minimally invasive approach to management. Journal of Pediatric Surgery 2007;42:629-635.
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- Grant, JP; James, S; Grabowski, V; Trexler, KM. Total parenteral nutrition in pancreatic disease. Annals of Surgery 1984;200:627-631.
- Wensil, Ashley M; Balasubramanian, Sailesh A; Bell, Tara L. Resolution of a Posttraumatic Pancreatic Pseudocyst with Octreotide Acetate in a Pediatric Patient. Pharmacotherapy 2011;31(9):924.
- Gorenstein, Arkadi; O’Halpin, Dara; Wesson, David E; Daneman, Alan; Filler, Robert M. Blunt Injury to the Pancreas in Children: Selective Management Based on Ultrasound. Journal of Pediatric Surgery 1987;22(12):1110-1116.
- Wiersema, MJ. Endosonography-guided cystoduodenostomy with a therapeutic ultrasound endoscope. Gastrointestinal Endoscopy 1996;44(5):614-617.
- Seitz, Guido; Warmann, Steven W; Kirschner, Hans-Joachim; Haber, Hans P; Schaefer, Juergen W; Fuchs, Joerg. Laparoscopic cystojejunostomy as a treatment option for pancreatic pseudocysts in children – a care report. Journal of Pediatric Surgery 2006;41:E33-E35.
- Yoder, Suzanne M; Rothenberg, Steven; Tsao, Kuojen; Wulkan, Mark L; Ponsky, Todd A; St. Peter, Shawn D; Ostlie, Daniel J; Kane, Timothy D. Laparoscopic Treatment of Pancreatic Pseudocysts in Children. Journal of Laparoendoscopic and Advanced Surgical Techniques 2009;19(Supplement1):S37-S40.
- Makris, Konstantinos I; St. Peter, Shawn D; Tsao, Kuo-Jen; Ostile, Daniel J. Laparoscopic Intragastric Stapled Cystgastrostomy of pancreatic Pseudocyst in a Child. Journal of Laparoendoscopic and Advanced Surgical Techniques 2008;18(5):771-773.
- Taghizadeh, F; Bower, RJ; Kiesewetter, WB. Stapled cystogastrostomy. A method of treatment for pediatric pancreatic pseudocyst. Annals of Surgery 1979;190(2):166-169.
- Kimble, Roy M; Cohen, Ralph; Williams, Stephen. Successful Endoscopic Drainage of a Posttraumatic Pancreatic Pseudocyst in a Child. Journal of Pediatric Surgery 1999;34(10):1518-1520.
- Haluszka, Oleh; Campbell, Andrew; Horvath, Karoly. Endoscopic management of pancreatic pseudocyst in children. Gastrointestinal Endoscopy 2002;55:128-131.
- Theodoros, Dionysis; Nikolaides, P; Petousis, G. Ultrasound-guided endoscopic transgastric drainage of a post-traumatic pancreatic pseudocyst in a child. African Journal of Pediatric Surgery 2010;7(3):194-196.
- Windle, R; Finlay, D; Neoptolemos, JP. Needle aspiration in the treatment of pancreatic pseudocyst in childhood. Annals of the Royal College of Surgeons of England 1983;65:331.
- Bass, Juan; Di Lorenzo, Maria; Desjardins, Jean G; Grignon, Andree; Ouimet, Alain. Blunt Pancreatic Injuries in Children: The Role of Percutaneous External Drainage in the Treatment of Pancreatic Pseudocysts. Journal of Pediatric Surgery 1988;23(8):721-724.
- Rescorla, Frederick J; Cory, David; Vane, Dennis W; West, Karen W; Grosfeld, Jay L. Failure of percutaneous drainage in children with traumatic pancreatic pseudocysts. Journal of Pediatric Surgery 1990;25:1038-1042.