Reply to Kobiela et al.

We thank the authors for taking an interest in our publication and raising some interesting arguments regarding the external EDGE procedure as a novel method for performing endoscopic retrograde cholangiopancreatography (ERCP) in patients with Roux-en-Y gastric bypass (RYGB) anatomy.

We agree that in an era where deep enteroscopy-assisted ERCP has a pooled procedural success rate of 61.7 %, direct access to the bypassed stomach by laparoscopic assistance has become the new standard [1]. However, with the advancing capabilities of therapeutic endoscopic ultrasound (EUS), laparoscopy-assisted ERCP (LA-ERCP) no longer boasts the previous advantages over endoscopy claimed by the authors. In particular, arguments for surgery being safer, more economical, and offering a single-stage procedure are strongly challenged by the EDGE procedure.

In terms of safety, the authors remark that two out of six patients in the EDGE series developed minor percutaneous endoscopic gastrostomy site infections. It is presumptuous to assume that this rate of infection in the initial brief experience of six patients will accurately predict the actual complication rate associated with this technique; we expect it to improve with further experience. In addition, these infections were minor; they were treated with oral antibiotics cautiously and resolved without further complications. These issues seem minor compared with the overall complication rate of 19 % associated with LA-ERCP, the vast majority (88 %) of which were related to access and not to the ERCP itself [2]. The conversion from laparoscopic to open gastrostomy in these patients is as high at 4.8 %, which is significant.

Second, although the EDGE procedure in our series was performed in two stages, multiple publications have demonstrated the feasibility of performing a single-stage, completely endoscopic, procedure in a safe manner [3] [4] [5]. The authors’ concern for leakage during a single-session endoscopic procedure is unfounded because the bypassed stomach is fixed to the abdominal wall using transcutaneous T-fasteners or a balloon catheter. In all three publications describing a single-stage technique, T-fasteners or a balloon catheter were used to secure the bypassed stomach and safely allowed for passage of a duodenoscope. There were zero adverse events of leakage in any of these studies. Thus, the feasibility of a one-stage endoscopic procedure has been established.

The authors also argue that LA-ERCP utilizes “limited resources’ compared with a completely endoscopic procedure. We strongly disagree with the authors for several reasons. First, LA-ERCP requires the involvement and coordination of two separate teams (surgical and endoscopic). Thus, from a human resource and cost standpoint, the EDGE procedure is more efficient. Second, the EDGE and ESTER procedures can be completed entirely in the endoscopy suite rather than the operating room. Operating room costs are vastly more expensive than the conventional endoscopy suites, thus making LA-ERCP a more costly procedure. A recent review of LA-ERCP quoted an average procedure time of 265 minutes [2] whereas the single-stage ESTER case series reported a mean procedure time of 88 minutes [4]. It is difficult to argue that 265 minutes of operating room time vs. 88 minutes of endoscopy suite time uses “limited resources.”

Finally, to the point about classifying EDGE as a “minimally invasive procedure.” We agree that technically the EDGE procedure uses the same route of access as LA-ERCP and is only less invasive in the sense that the patient is not undergoing actual surgery with incision through the fascia. Although this may not be a monumental difference in method of access, the external EDGE serves as a bridge to the next step in “minimally invasive” endoscopy in RYGB, which is the internal EDGE procedure. We have since published the feasibility of performing a single-stage, single-operator, completely internal EUS-directed ERCP in RYGB by the formation of a gastrogastric fistula [6]. Thus, the patient wakes up with no skin incisions at all after biliary intervention. This procedure is monumental in the leap it makes, from both an invasive and technical standpoint.

Both the external and internal EDGE procedures are exciting in terms of what they are capable of offering the growing RYGB population. Although they are new and require further study, emerging data are beginning to seriously challenge the predictable critiques from the old guard.

• References

• 1 Inamdar S, Slattery E, Sejpal DV et al. Systematic review and meta-analysis of single-balloon enteroscopy-assisted ERCP in patients with surgically altered GI anatomy. Gastrointest Endosc 2015; 82: 9-19
• 2 Grimes KL, Maciel VH, Mata W et al. Complications of laparoscopic transgastric ERCP in patients with Roux-en-Y gastric bypass. Surg Endosc 2015; 29: 1753-1759
• 3 Law R, Song LMWK, Petersen BT et al. Single-session ERCP in patients with previous Roux-en-Y gastric bypass using percutaneous-assisted transprosthetic endoscopic therapy: a case series. Endoscopy 2013; 45: 671-675
• 4 Attam R, Leslie D, Arain MA et al. EUS-guided sutured gastropexy for transgastric ERCP (ESTER) in patients with Roux-en-Y gastric bypass: a novel, single-session, minimally invasive approach. Endoscopy 2015; DOI: 10.1055/s-0034-1391124.
• 5 Thompson CC, Ryou MK, Kumar N et al. Single-session EUS-guided transgastric ERCP in the gastric bypass patient. Gastrointest Endosc 2014; 80: 517
• 6 Kedia P, Sharaiha RZ, Kumta NA et al. Internal EUS-directed transgastric ERCP (EDGE): game over. Gastroenterology 2014; 147: 566-568