Anatomy

The classic Whipple operation involves removal of pancreatic head, pancreatic neck, gastric antrum, duodenum, 20 cm of proximal jejunum, gallbladder (if present), distal common bile duct, and regional lymph nodes. There are two side-to-side enteroenterostomies visible from the gastric remnant (Fig. 42.1). The afferent limb, which is usually 40 to 60 cm long, ascends superiorly and ends blindly with an end-to-end or end-to-side pancreaticojejunostomy. An end-to-side choledochojejunostomy is usually located 10 cm proximal to the end of the afferent limb and is located along the antimesenteric border, often behind a mucosal fold.

Fig. 42.1 Illustration of a classic pancreaticoduodenectomy. Note the antrectomy with gastrojejunal anastomosis.

Pylorus-preserving pancreaticoduodenectomy (modified Whipple) is performed to prevent delayed gastric emptying. The entire stomach is preserved and the bulk of the duodenal bulb remains (Fig. 42.2). Upon exiting the stomach, a duodenal stump is encountered with two end-to-side enteroenterostomies, with one leading to the afferent limb containing the biliary and pancreatic anastomoses (Fig. 42.3). The location of the afferent limb within the visual field is not uniform and also is dependent on the type of endoscope used (side-viewing versus forward-viewing).

Fig. 42.2 Illustration of a pylorus-preserving pancreaticoduodenectomy.

Fig. 42.3 Endoscopic image of the afferent and efferent limbs taken from inside the duodenal stump of a pylorus-preserving pancreaticoduodenectomy.

Role of Endoscopy in the Management of Adverse Events

Endoscopy plays a very limited role in the management of acute postoperative adverse events following Whipple surgery. Pancreatic leaks, although reported to occur in up to 20% of Whipple surgeries, are managed by percutaneous drainage, administration of octreotide, and intravenous hyperalimentation. However, endoscopy plays a significant role in the management of delayed pancreaticobiliary strictures and/or stones (Box 42.2). The decision about the necessity of endoscopic intervention is made with the aid of abdominal computed tomography (CT) or magnetic resonance cholangiopancreatography (MRCP) with or without secretin.

Box 42.2

Adverse Events of Pancreaticoduodenectomy and Pylorus-Preserving Pancreaticoduodenectomy

 Early adverse events

 Pancreatic duct leak

 Pancreatic fistula

 Bile leak

 Hemorrhage

 Wound infection

 Abscess

 Afferent limb syndrome

 Delayed gastric emptying

 Delayed adverse events

 Stenosis of choledochojejunostomy (presenting as cholangitis, jaundice)

 Stenosis of pancreaticojejunostomy (presenting as abdominal pain, pancreatitis with or without pancreatic duct stones)

 Recurrence of malignancy

 Retained surgically placed pancreatic stent

 Diabetes mellitus

Prior to embarking on endoscopy, it is imperative to plan, which includes choice of endoscope, accessories, patient position, and need for anesthesia support, so that optimal outcomes can be achieved in this subset of patients (Box 42.3; see also Chapter 9).

Box 42.3

Checklist before Starting Endoscopy

 Choice of endoscope

 Duodenoscope

 Pediatric colonoscope with or without variable-stiffness feature

 Adult (therapeutic channel) colonoscope with or without variable-stiffness feature

 Prototype oblique-viewing endoscope with elevator

 Single-balloon enteroscope

 Double-balloon enteroscope (short versus long)

 Linear echoendoscope

 Accessories

 Standard ERCP accessories

 Long-length accessories

 EUS-FNA needle

 Patient position

 Prone

 Supine

 Left oblique

 Left lateral

 Anesthesia

 Moderate sedation

 Monitored anesthesia care

 General anesthesia

In classic Whipple surgery, the biliary anastomosis may be reached with a standard duodenoscope. The side-viewing endoscope offers technical advantages of an en face view of the anastomosis and presence of an elevator to assist in control of accessories. However, the success rate in accessing the pancreatic anastomosis is suboptimal at best.¹A widely patent anastomosis is seen in Fig. 42.4.

Fig. 42.4 Endoscopic images of representative widely patent choledochojejunostomies after pancreaticoduodenectomy from two different patients.

Not uncommonly, the approach using a side-viewing endoscope results in failure to reach either the biliary or the pancreatic anastomosis due to the insertion tube length. This is especially true in patients with pylorus-preserving anatomy and longer afferent limbs. In these cases, the procedure may be accomplished with a colonoscope. Therapeutic channel colonoscopes allow placement of 10 Fr plastic biliary stents. Some biliary self-expandable metal stents can be passed through colonoscopes (both pediatric and adult).² However, absence of an elevator makes it challenging to maneuver the accessories and accomplish therapeutic intervention. To circumvent this drawback, a prototype oblique-viewing endoscope with an elevator has been used.

Various other techniques can be employed to gain access to the end of the afferent limb and the biliopancreatic anastomoses (Box 42.4).

There are limited but increasing data on the use of single-balloon enteroscopes (SBE)^3,4 and double-balloon enteroscopes (DBE)⁵ in achieving technical success in accessing biliary and pancreatic anastomoses. These procedures are performed by experienced endoscopists at tertiary care centers when ERCP failure is due to inability to reach the anastomosis with standard endoscopes. Balloon-assisted ERCP is often time consuming and difficult due to the limited availability of compatible accessories.

Bilioenteric Anastomotic Stricture

Bilioenteric anastomotic strictures can be benign or malignant due to recurrent disease such as pancreatic cancer, primary sclerosing cholangitis, or autoimmune disease. Distinguishing between the two can be extremely difficult due to submucosal tumor invasion. Treatment of these strictures is undertaken as for other benign (Fig. 42.5) and malignant strictures, although the options can be limited by the endoscope length and channel diameter. In some cases, needle-knife entry can be undertaken, though this carries risk of perforation (Video 42.1).

Fig. 42.5 Endoscopic therapy for a choledochojejunal anastomotic stricture after pancreaticoduodenectomy.

Afferent Limb Obstruction

Afferent limb obstruction is often due to recurrent tumor, usually occurring at the ligament of Treitz, but can also occur from radiation therapy. Such downstream obstruction most commonly presents with obstructive jaundice or cholangitis. Other presenting symptoms include abdominal pain, nausea, and vomiting. The most common endoscopic findings are malignant or benign luminal stricturing of the afferent limb, severe angulation of or fixed afferent limb, and mucosal changes of friability, ulceration, and telangiectasia from radiation enteropathy. Endoscopic interventions performed for management include placement of plastic and self-expandable metal stents in the afferent limb and/or obstructed bile duct (Video 42.2).⁶