Single-step endoscopic ultrasonography-guided drainage of peripancreatic fluid collections with a single self-expandable metal stent and standard linear echoendoscope

• Introduction
• Case series
• Patients and methods
• Results
• Discussion
• Conclusion
• References

Endoscopic ultrasonography (EUS)-guided drainage of peripancreatic fluid collections (PFCs) is a well described alternative to surgery or percutaneous drainage. However, it is limited by the requirement for a large working channel that allows multiple plastic stent placement, which is only commercially available on therapeutic linear echoendoscopes. Herein, we describe the drainage of PFCs with a single self-expandable metal stent (SEMS) using a single-step technique and standard linear echoendoscope. Seven cases were identified during a retrospective chart review, and included all patients who had undergone EUS-guided drainage of PFCs during a 6-month period. The mean age was 46 years (range 25 – 70 years) and all patients were symptomatic. The mean diameter of PFCs was 8 cm (range 4.1 – 12.5 cm). Previous percutaneous drainage had failed in three patients. A total of 10 PFCs were drained. Three patients had two cysts drained by the same stent and one patient had two separate procedures to drain two distinct cysts. The SEMS was in place for a mean of 13 weeks (range 4 – 34 weeks). Successful placement of SEMS was achieved in all seven cases. Patients were followed for a mean of 18 weeks (range 7 – 35 weeks), and symptom improvement was achieved in all cases. Complete resolution of PFC was achieved in 9 /10 cysts. No complications were encountered. Single-step EUS-guided drainage of PFCs using a single 10-mm SEMS and a standard linear echoendoscope appears to be a feasible endoscopic technique with excellent technical and clinical success rates.

Introduction

Endoscopic drainage of peripancreatic fluid collections (PFCs) has been well described as a minimally invasive alternative to surgery or percutaneous drainage [1]. Outcomes from the conventional “blind” transmural approach have been improved by the use of endoscopic ultrasonography (EUS)-guided drainage, a technique that reduces the risk of bleeding and perforation, as well as allows access to non-bulging PFCs, in particular those located in the tail of the pancreas [2] [3].

Single-step EUS-guided drainage has replaced the traditional two-step approach, as it reduces procedure time, sedation requirements, and patient discomfort [4] [5] [6]. In addition, higher success rates have been described with the use of larger diameter or multiple plastic stents [7] [8].

However, EUS-guided drainage of PFCs with a single-step technique and using large plastic stents is limited by the requirement for a large working channel that is only commercially available in the USA on therapeutic linear echoendoscopes. The aim of the current study was to evaluate the technical and clinical success and safety of PFC drainage using a single 10-mm self-expandable metal stent (SEMS) placed under EUS guidance in a single-step technique using a standard linear echoendoscope.

Case series

Patients and methods

A total of seven consecutive cases from six patients who were referred for evaluation of symptomatic PFCs between November 2010 and April 2011 at three tertiary care hospitals in Houston (Texas, USA) were considered for the study. A contrast-enhanced computed tomography (CT) scan was performed prior to EUS-guided drainage. Distinction between the types of PFCs was made. Pseudocyst was defined as an encapsulated fluid collection that persisted for 4 – 6 weeks after an episode of acute pancreatitis. Walled off pancreatic necrosis (WOPN) was defined as liquefied necrosis greater than 30 % of the gland size that persisted for 5 – 6 weeks after diagnosis [9]. Patients who were not already receiving broad-spectrum antibiotics for empiric treatment of pancreatic infected necrosis or abscess were treated with prophylactic antibiotics for 10 – 14 days. All EUS procedures were performed using a standard-sized linear echoendoscope (GF-UC140PAL5 [Olympus, Tokyo, Japan] or 3870-UGK [Pentax, Tokyo, Japan]). All patients underwent placement of a fully covered 10-mm SEMS (VIABIL, Conmed, Utica, New York, New York, USA). All procedures were performed by the same endoscopist (Y.H.S.), who was experienced in both EUS and endoscopic retrograde cholangiopancreatography (ERCP).

Informed consent was obtained from all patients for SEMS placement under EUS-guidance. This retrospective review was approved by the local institutional review board.

The following procedural steps were carried out in sequence ([Video 1]).

1. Using a standard linear echoendoscope, the best site to access the PFC was identified. Vascular structures within the tract were avoided by using Doppler ultrasound. A 19-gauge needle (Cook Endoscopy, Winston Salem, North Carolina, USA) was introduced into the PFC under EUS guidance ([Fig. 1a]). A fluid sample was then collected in a sterile syringe and sent for microbiological analysis (culture and Gram-staining); samples were analyzed only for those patients with suspected infection.

2. A 0.035-inch biliary guide wire was threaded through the needle into the cyst ([Fig. 1b]). Fluoroscopic imaging was used to confirm the wire coiling inside the cyst. The needle was removed over the guide wire and a needle-knife catheter was then placed over the wire to make a small cut in the gastric wall.

3. The needle-knife was exchanged for a sphincterotome, which was used to cannulate the cystogastrostomy tract and slightly dilate the tract. After the sphincterotome was removed over the wire, an 8-mm biliary balloon dilator was passed into the tract ([Fig. 1c]). The balloon was expanded using contrast to allow the balloon to be visualized under fluoroscopy. After 30 seconds, the balloon was deflated and removed over the wire.

4. A removable SEMS, measuring 10 mm in diameter, was then inserted over the wire and deployed into the cyst, cystogastrostomy tract, and stomach under fluoroscopic guidance ([Fig. 1 d]). The stent deployment system, guide wire, and scope were then removed, bringing the procedure to an end.

All patients were observed for 24 – 48 hours and then discharged with a follow-up clinic appointment 4 – 6 weeks later, at which stage they underwent repeat CT scan of the abdomen ([Fig. 2]). The stent was then removed if complete resolution of the PFC had been achieved. Patients with partial resolution of the PFC underwent an esophagogastroduodenoscopy (EGD) to confirm patency of the stent by intubating the PFC through the SEMS using an ultra-slim upper endoscope (Olympus BF-XP160F) ([Fig. 3a]), followed by a repeat CT scan of the abdomen 4 weeks later. This was repeated as necessary until resolution of the PFC, malfunction of the stent, or the patient required an alternative drainage method (e. g. surgery).

Results

[Table 1] shows the clinical characteristics of the patients. The mean age at presentation was 46 years (range 25 – 70 years). All patients were symptomatic. The mean diameter of PFCs was 8 cm (range 4.1 – 12.5 cm).

A total of 10 PFCs were drained in six patients. Three patients (cases 4, 5, and 6) each had two cysts drained by the same stent, and one patient (cases 1 and 2) underwent two separate procedures to drain two distinct cysts.

Previous non-endoscopic drainage had failed in three patients; two had undergone percutaneous drainage. One of these patients (patient no. 4) had severe gallstone pancreatitis complicated by two PFCs. ERCP during the same admission showed no evidence of communication between the pancreatic duct and the PFC. This patient was managed conservatively, but returned 2 months later with sepsis. Interventional radiology placed two drains into WOPN, which was found to be infected with Klebsiella pneumoniae. Drains were removed 20 days later after evidence of clinical and radiological improvement. The patient was re-admitted 1 month later with recurrence of sepsis and PFC, at which time the cystogastrostomy was performed.

The other patient (case no. 3) had severe acute pancreatitis complicated with PFC after high dose steroids for lupus nephritis. She was managed conservatively but was re-admitted 3 months later with nausea, vomiting, and abdominal pain. CT scan showed evidence of two PFCs (body and tail). The larger one in the body was drained percutaneously by interventional radiology. A repeat CT scan performed 1 week later due to persistence of symptoms showed an increase in size of the tail PFC with some improvement of the body PFC. The patient then proceeded with cystogastrostomy of the tail PFC.

The third patient (case no. 7) had acute hemorrhagic pancreatitis with fractured pancreatic duct after blunt trauma to the abdomen a year before presentation. Transpapillary drainage by ERCP failed due to the inability to advance a stent into the tail of the pancreas. This was followed by four failed percutaneous drainage attempts before undergoing cystogastrostomy.

Clinical outcomes are shown on [Table 2]. The SEMS was in place for a mean of 13 weeks (range 4 – 34 weeks). Technical success (successful placement of SEMS) was achieved in all seven cases. Patients were followed for a mean of 18 weeks (range 7 – 35 weeks). Clinical success (symptom improvement) was achieved in all patients. Complete resolution of PFC was achieved in 9 /10 cysts; one patient with two cysts (case no. 6) had complete resolution of the larger cyst in the body and a 50 % reduction in size of the other cyst in the tail.

All SEMS were removed without difficulty by looping the proximal end of the stent with a polypectomy snare and pulling the stent into the stomach ([Fig.3b]). No evidence of stent ingrowth or migration was noted.

No complications were encountered. One patient died 7 weeks after stent placement from causes unrelated to the procedure.

Discussion

The use of endoscopic drainage of PFCs is increasing as the primary treatment modality in centers with the available expertise [3]. EUS-guided drainage reduces the risk of bleeding and perforation associated with the conventional transmural approach. It also allows access to non-bulging PFCs, particularly those located in the tail of the pancreas [2]. EUS-guided drainage also allows further assessment of the fluid collection, and may result in change to the initial diagnosis and intervention [2] [10].

EUS-guided drainage is associated with reduced morbidity, faster recovery, and is less expensive than surgery. It is also preferred over percutaneous drainage, as it avoids local complications such as bleeding, unintentional puncture through adjacent viscera, skin and soft tissue infections, and development of pancreatico-cutaneous fistulas [3]. Endoscopic drainage also allows removal of solid necrotic debris, which is not possible with a percutaneous approach [11]. However, both surgery and percutaneous drainage remain important adjunctive modalities in the treatment of PFCs [1].

Initially, EUS was used to mark the best access site for the PFC. The echoendoscope was then exchanged for a duodenoscope for puncturing and stent placement. With the development of larger channel (therapeutic) echoendoscopes, single-step EUS-guided drainage has replaced the traditional two-step approach [5]. Single-step EUS-guided drainage reduces procedure time, sedation requirements, and patient discomfort [4] [5] [6].

Vilmann et al. were the first authors to describe single-step EUS-guided drainage of a pancreatic pseudocyst using a prototype echoendoscope [12]. Over the past decade, multiple case series have been published, all of which have used the therapeutic echoendoscope [2] [5] [13]. Dependence on a large channel echoendoscope arises from the need to place a stent with the largest possible diameter. Smaller stents are likely to suffer premature clogging, particularly when used to drain cysts that contain debris [14].

The risk of infection due to premature clogging of the stent can be reduced by placement of multiple plastic stents. However, multiple stent placement requires repeated access to the cyst (which can be difficult), prolongs the procedure time, and will not achieve the same degree of drainage provided by a larger stent [7].

Recent developments in dedicated EUS-guided drainage accessories permit placement of 10-Fr plastic stents with the guidance of a therapeutic echoendoscope, while achieving an acceptable (82 %) success rate. Yet a high rate of stent migration (27 %) was reported, with two of the patients requiring surgery in order to recover the stent [5].

Talreja et al. described the concomitant placement of a 10-Fr plastic stent and a 10-mm SEMS for drainage of PFCs under guidance of a therapeutic echoendoscope. In their series, the authors reported a 95 % success rate and a 75 % complete resolution of the PFCs, but with a high complication rate of over 40 %, including one stent migration [13]. Based on our results, the combination of a plastic stent with an SEMS is probably unnecessary, as we were able to achieve similar success rates (100 %) without complications, while using the same type of SEMS.

Recently, a small case series (three patients) on the use of a single, specially customized, partially covered, large diameter (18 – 25 mm) SEMS for repeated through-the-stent endoscopic necrosectomy was reported. However, this stent is not commercially available in the USA [15].

Commercially available fully covered SEMS could be an attractive alternative to plastic stents as they can achieve larger diameters, while avoiding multiple stent placements and without the need for a therapeutic echoendoscope for deployment.

The main limitation of this study is that it was a retrospective non-randomized small case series, conducted at tertiary care centers.

Conclusion

Single-step EUS-guided drainage of PFCs using a single 10-mm SEMS and a standard linear echoendoscope appears to be a safe and feasible endoscopic technique with excellent technical and clinical success rates and no complications. Further randomized trials comparing plastic and metal stents are necessary.

Competing interests: None.

• References

• 1 Lawson JM, Baillie J. Endoscopic therapy for pancreatic pseudocysts. Gastrointest Endosc Clin N Am 1995; 5: 181-193
  PubMedSearch in Google Scholar
• 2 Varadarajulu S, Wilcox CM, Tamhane A et al. Role of EUS in drainage of peripancreatic fluid collections not amenable for endoscopic transmural drainage. Gastrointest Endosc 2007; 66: 1107-1119
  Search in Google Scholar
• 3 Seewald S, Ang TL, Teng KC et al. EUS-guided drainage of pancreatic pseudocysts, abscesses and infected necrosis. Dig Endosc 2009; 21: 61-65
  CrossrefPubMedSearch in Google Scholar
• 4 Varadarajulu S, Tamhane A, Blakely J. Graded dilation technique for EUS-guided drainage of peripancreatic fluid collections: an assessment of outcomes and complications and technical proficiency (with video). Gastrointest Endosc 2008; 68: 656-666
  CrossrefPubMedSearch in Google Scholar
• 5 Ahlawat SK, Charabaty-Pishvaian A, Jackson PG et al. Single-step EUS-guided pancreatic pseudocyst drainage using a large channel linear array echoendoscope and cystotome: results in 11 patients. JOP 2006; 7: 616-624
  Search in Google Scholar
• 6 Kitano M, Sakamoto H, Komaki T et al. Present status and future perspective of EUS-guided drainage. Dig Endosc 2009; 21: 66-70
  CrossrefPubMedSearch in Google Scholar
• 7 Baron TH, Morgan DE. Acute necrotizing pancreatitis. N Engl J Med 1999; 340: 1412-1417
  CrossrefPubMedSearch in Google Scholar
• 8 Norton ID, Clain JE, Wiersema MJ et al. Utility of endoscopic ultrasonography in endoscopic drainage of pancreatic pseudocysts in selected patients. Mayo Clin Proc 2001; 76: 794-798
  CrossrefPubMedSearch in Google Scholar
• 9 Tenner S, Sica G, Hughes M et al. Relationship of necrosis to organ failure in severe acute pancreatitis. Gastroenterology 1997; 113: 899-903
  CrossrefPubMedSearch in Google Scholar
• 10 Fockens P, Johnson TG, van Dullemen HM et al. Endosonographic imaging of pancreatic pseudocysts before endoscopic transmural drainage. Gastrointest Endosc 1997; 46: 412-416
  CrossrefPubMedSearch in Google Scholar
• 11 Seewald S, Groth S, Omar S et al. Aggressive endoscopic therapy for pancreatic necrosis and pancreatic abscess: a new safe and effective treatment algorithm (videos). Gastrointest Endosc 2005; 62: 92-100
  Search in Google Scholar
• 12 Vilmann P, Hancke S, Pless T et al. One-step endosonography-guided drainage of a pancreatic pseudocyst: a new technique of stent delivery through the echo endoscope. Endoscopy 1998; 30: 730-733
  Thieme ConnectPubMedSearch in Google Scholar
• 13 Talreja JP, Shami VM, Ku J et al. Transenteric drainage of pancreatic-fluid collections with fully covered self-expanding metallic stents (with video). Gastrointest Endosc 2008; 68: 1199-1203
  CrossrefPubMedSearch in Google Scholar
• 14 Cremer M, Deviere J, Engelholm L. Endoscopic management of cysts and pseudocysts in chronic pancreatitis: long-term follow-up after 7 years of experience. Gastrointest Endosc 1989; 35: 1-9
  CrossrefPubMedSearch in Google Scholar
• 15 Belle S, Collet P, Post S et al. Temporary cystogastrostomy with self-expanding metallic stents for pancreatic necrosis. Endoscopy 2010; 42: 493-495
  Search in Google Scholar

Corresponding author

• References

• 1 Lawson JM, Baillie J. Endoscopic therapy for pancreatic pseudocysts. Gastrointest Endosc Clin N Am 1995; 5: 181-193
  PubMedSearch in Google Scholar
• 2 Varadarajulu S, Wilcox CM, Tamhane A et al. Role of EUS in drainage of peripancreatic fluid collections not amenable for endoscopic transmural drainage. Gastrointest Endosc 2007; 66: 1107-1119
  Search in Google Scholar
• 3 Seewald S, Ang TL, Teng KC et al. EUS-guided drainage of pancreatic pseudocysts, abscesses and infected necrosis. Dig Endosc 2009; 21: 61-65
  CrossrefPubMedSearch in Google Scholar
• 4 Varadarajulu S, Tamhane A, Blakely J. Graded dilation technique for EUS-guided drainage of peripancreatic fluid collections: an assessment of outcomes and complications and technical proficiency (with video). Gastrointest Endosc 2008; 68: 656-666
  CrossrefPubMedSearch in Google Scholar
• 5 Ahlawat SK, Charabaty-Pishvaian A, Jackson PG et al. Single-step EUS-guided pancreatic pseudocyst drainage using a large channel linear array echoendoscope and cystotome: results in 11 patients. JOP 2006; 7: 616-624
  Search in Google Scholar
• 6 Kitano M, Sakamoto H, Komaki T et al. Present status and future perspective of EUS-guided drainage. Dig Endosc 2009; 21: 66-70
  CrossrefPubMedSearch in Google Scholar
• 7 Baron TH, Morgan DE. Acute necrotizing pancreatitis. N Engl J Med 1999; 340: 1412-1417
  CrossrefPubMedSearch in Google Scholar
• 8 Norton ID, Clain JE, Wiersema MJ et al. Utility of endoscopic ultrasonography in endoscopic drainage of pancreatic pseudocysts in selected patients. Mayo Clin Proc 2001; 76: 794-798
  CrossrefPubMedSearch in Google Scholar
• 9 Tenner S, Sica G, Hughes M et al. Relationship of necrosis to organ failure in severe acute pancreatitis. Gastroenterology 1997; 113: 899-903
  CrossrefPubMedSearch in Google Scholar
• 10 Fockens P, Johnson TG, van Dullemen HM et al. Endosonographic imaging of pancreatic pseudocysts before endoscopic transmural drainage. Gastrointest Endosc 1997; 46: 412-416
  CrossrefPubMedSearch in Google Scholar
• 11 Seewald S, Groth S, Omar S et al. Aggressive endoscopic therapy for pancreatic necrosis and pancreatic abscess: a new safe and effective treatment algorithm (videos). Gastrointest Endosc 2005; 62: 92-100
  Search in Google Scholar
• 12 Vilmann P, Hancke S, Pless T et al. One-step endosonography-guided drainage of a pancreatic pseudocyst: a new technique of stent delivery through the echo endoscope. Endoscopy 1998; 30: 730-733
  Thieme ConnectPubMedSearch in Google Scholar
• 13 Talreja JP, Shami VM, Ku J et al. Transenteric drainage of pancreatic-fluid collections with fully covered self-expanding metallic stents (with video). Gastrointest Endosc 2008; 68: 1199-1203
  CrossrefPubMedSearch in Google Scholar
• 14 Cremer M, Deviere J, Engelholm L. Endoscopic management of cysts and pseudocysts in chronic pancreatitis: long-term follow-up after 7 years of experience. Gastrointest Endosc 1989; 35: 1-9
  CrossrefPubMedSearch in Google Scholar
• 15 Belle S, Collet P, Post S et al. Temporary cystogastrostomy with self-expanding metallic stents for pancreatic necrosis. Endoscopy 2010; 42: 493-495
  Search in Google Scholar