Reply to Laleman and Van der Merwe

We appreciate the interest of Laleman and Van der Merwe in our recent case series [1].

In our discussion of this series of cases, we have been cautious, aware of the fact that currently the gold standard involves the use of plastic stents; indeed, our conclusion was “A larger prospective randomized study should be carried out to compare this technique with conventional drainage using plastic stents in order to validate these findings.”

In current practice it is thought that sterile pancreatic fluid collections should be drained with plastic stents because this technique has been proven to be safe and effective [2 – 6]. Unlike sterile fluid collections, infected collections are more viscous with large amounts of debris; hence, they are difficult to drain. The size of the conventional plastic stents used for pancreatic fluid collection drainage is limited to 10 Fr. It has therefore been suggested that the placement of larger or multiple stents and a nasocystic drainage catheter may facilitate resolution, especially in pancreatic fluid collections with significant debris [5,7].

However, the conventional technique, which uses one or more plastic stents for drainage, has been associated with the need for multiple revisions due to obstruction and subsequent clogging, which may occur as the result of the adhesion of a bacterial biofilm, but may also be due to the obstruction of small-caliber stents by necrotic tissue [6,8]. In addition, if a nasocystic drain is used, it can result in a prolonged hospital stay and increased patient discomfort.

Varadarajulu et al. [7] showed that necrotic collections drained through two or three transmural tracts, with multiple stents in each tract, and nasocystic drainage had better outcomes compared with necrotic collections treated by conventional drainage techniques. This report would seem to indicate that better drainage of the cavity facilitated better drainage of the necrotic contents.

All three studies cited by Laleman and Van der Merwe in their letter [2 – 4] reported the experience of endoscopic drainage of different types of pancreatic fluid collections (infected and noninfected, among others), thus these results are not comparable to the results of our series because we recruited only patients with infected pancreatic fluid collections, excluding patients with sterile pancreatic fluid collections and those with organized pancreatic necrosis.

Moreover in the study of Hookey et al. [3], endoscopic ultrasound-guided transmural drainage (EUS-GTD) of nonorganized infected necrosis using plastic stents and nasocystic catheter placement resulted in overall technical success, clinical success, recurrence, and complication rates of 50 %, 25 %, 12.5 %, and 25 %, respectively.

We excluded patients with organized pancreatic necrosis because we felt that the best treatment for this is endoscopic necrosectomy [9].

With regard to cost, it is more realistic to consider not only the cost of the stents, but the costs of all the materials used for the entire procedure and the hospitalization time. When EUS-GTD is performed for infected collections with covered self-expanding metal stents (CSEMSs), the cost is: a 19-gauge needle, 300 euros; a 0.035-inch wire, 150 euros; a precut needle-knife, 150 euros; and a CSEMS, 1000 euros. For the same procedure using plastic stents along with placement of a nasocystic catheter, the cost is: a 19-gauge needle, 300 euros; three 0.035-inch wires, 450 euros; a precut needle-knife, 150 euros; a balloon dilatator, 250 euros; two plastic stents, 200 euros; and a nasocystic catheter, 100 euros. This cost would double in the case of eventual revision.

In our series, we used two different types of CSEMSs having the same technical characteristics (both constructed with the same material [nitinol], both with flared ends, and both of the same size [10 mm]). The 40-mm long CSEMSs were inserted into the bulging collections; whereas, for non-bulging collections, 60-mm long CSEMSs were used.

The drainage of an infected pancreatic fluid collection requires the insertion of both a transmural stent and a nasocystic catheter. If more than one stent and nasocystic catheter needs to be inserted, the pancreatic fluid collection must be recannulated and a second guide wire must be inserted before the procedure. Recannulation is difficult because of the collapse of the pancreatic fluid collection cavity, the presence of pus, and viscous chocolate-brown necrotic materials gushing out from the cavity, which obscure the endoscopic view, and the tangential axis of the puncture tract. Inserting a single CSEMS of 1 cm in diameter at the initial pancreatic fluid collection puncture would overcome the difficulty involved in pancreatic fluid collection recannulation.

Candida species are frequently found in pancreatic fluid collections [9]. There is debate about whether the presence of fungi truly represents infection or simply the colonization of the pancreatic fluid collection [10]. In our clinical practice and considering the characteristics of the patients enrolled, we prefer to be prudent.

As stated by Todd H. Baron in a beautiful editorial [11], “there is more than one way to skin a cat” (citing a sentence written by Mark Twain in 1889, from A Connecticut Yankee in King Arthur’s Court, “She was wise, subtle, and knew more than one way to skin a cat”), and, in the same way, there are different ways of treating the same disease.

• References

• 1 Fabbri C, Luigiano C, Cennamo V et al. Endoscopic ultrasound-guided transmural drainage of infected pancreatic fluid collections with placement of covered self-expanding metal stents: a case series. Endoscopy 2012; 44: 429-433
• 2 Cahen D, Rauws E, Fockens P et al. Endoscopic drainage of pancreatic pseudocysts: long-term outcome and procedural factors associated with safe and successful treatment. Endoscopy 2005; 37: 977-983
• 3 Hookey LC, Debroux S, Delhaye M et al. Endoscopic drainage of pancreatic-fluid collections in 116 patients: a comparison of etiologies, drainage techniques, and outcomes. Gastrointest Endosc 2006; 63: 635-643
• 4 Arvanitakis M, Delhaye M, Bali MA et al. Pancreatic fluid collections: a randomized controlled trial regarding stent removal after endoscopic transmural drainage. Gastrointest Endosc 2007; 65: 609-619
• 5 Kahaleh M, Shami VM, Conway MR et al. Comparison of EUS and conventional endoscopic drainage of pancreatic pseudocyst. Endoscopy 2006; 38: 355-359
• 6 Lopes CV, Pesenti C, Bories E et al. Endoscopic-ultrasound-guided endoscopic transmural drainage of pancreatic pseudocysts and abscesses. Scand J Gastroenterol 2007; 42: 524-529
• 7 Varadarajulu S, Bang JY, Phadnis MA et al. Endoscopic transmural drainage of peripancreatic fluid collections: outcomes and predictors of treatment success in 211 consecutive patients. J Gastrointest Surg 2011; 15: 2080-2088
• 8 Kruger M, Schneider AS, Manns MP et al. Endoscopic management of pancreatic pseudocysts or abscesses after an EUS-guided 1-step procedure for initial access. Gastrointest Endosc 2006; 63: 409-416
• 9 Seifert H, Biermer M, Schmitt W et al. Transluminal endoscopic necrosectomy after acute pancreatitis: a multicentre study with long-term follow-up (the GEPARD Study). Gut 2009; 58: 1260-1266
• 10 Warshaw A. Pancreatic necrosis: to debride or not to debride – that is the question. Ann Surg 2000; 232: 627-629
• 11 Baron TH. Drainage of pancreatic fluid collections: is EUS really necessary?. Gastrointest Endosc 2007; 66: 1123-1125