Pylorus-Preserving Pancreaticoduodenectomy (PPPD) Technique

The steps for completion of a pylorus-preserving pancreaticoduodenectomy (PPPD) can be thought of as a clockwise journey. The surgeon begins at the ascending colon and hepatic flexure to obtain exposure of the superior mesenteric vein (SMV), then moves to the porta hepatis for cholecystectomy and portal lymph node dissection, followed by transection of the stomach or proximal duodenum. He or she then proceeds to jejunal transection and, finally, pancreatic transection, with completion of retroperitoneal dissection and removal of the specimen en bloc.

The reconstructions can be performed in a counterclockwise direction: The surgeon starts with creation of jejunal feeding access and then proceeds to creation of the pancreaticojejunal, choledochojejunal, and enterojejunal anastomoses. Venous reconstructions are also undertaken in select patients who need venous resection for involvement by the tumour.

An example of a PPPD is shown in the video below.

Laparotomy and abdominal exploration

Laparotomy is performed with a generous midline incision or bilateral subcostal incisions. The liver is palpated, the peritoneum is inspected, and the paraortic lymph nodes and the root of the mesentery are evaluated.

Intraoperative hepatic ultrasonography (US) may be used when preoperative imaging is not definitive. In addition, abdominal exploration may be undertaken as staging laparoscopy before laparotomy in patients with advanced disease (eg, a large tumor or very high carbohydrate antigen [CA] 19.9 level) who are suspected of being at risk for radiographically silent metastatic disease.

Exposure of superior mesenteric artery and extended kocherization

A self-retaining retractor facilitates general exposure of the operative field. The falciform ligament is identified and preserved for later use (to protect the gastroduodenal artery [GDA] stump). The ascending colon and hepatic flexure are mobilized by using a Cattell-Brasch maneuver or right medial visceral rotation to expose the third and fourth portions of the duodenum.

The lesser sac is then opened and entered. Here, the middle colic vein is encountered and ligated, facilitating exposure of the SMV. The gastroepiploic vein is often seen entering the gastrocolic trunk (GCT) with the middle colic vein and can be ligated when encountered.

Next, an extended Kocher maneuver is performed from the right ureter and right gonadal vein junction (which may be ligated and mobilized) until the aorta and the crossing left renal vein are identified. Intervening lymphatic tissues should be mobilized as well. Here, the superior mesenteric artery (SMA) should be identifiable.

Cholecystectomy and portal dissection

The celiac axis is located, and the left gastric artery is identified and preserved. The node of the common hepatic artery is removed, and the common hepatic artery is dissected proximal and distal to the GDA takeoff. This is done carefully (because the common hepatic artery is fragile), and the GDA is transected. Cholecystectomy is performed with transection of the specimen at the common hepatic duct (CHD) just above the joining of the cystic duct. The CHD margin undergoes intraoperative pathologic analysis and is extended if necessary.

Given the anatomic variability of hepatic arterial circulation, the surgeon must look for a replaced right hepatic artery or replaced common hepatic artery. After the origins of the aforementioned are identified, medial retraction applied to the common hepatic artery exposes the anterior surface of the portal vein (PV). The PV is followed to its junction with the SMV behind the pancreatic neck, with the surgeon taking great care to avoid traction injury to the posterior pancreatic duodenal vein.

Duodenal transection if PPPD permissible

In concordance with accepted oncologic principles, bulky neoplasms of the pancreatic head, tumors progressing to the first or second part of the duodenum, or clinically positive regional lymph nodes noted at this juncture preclude pylorus preservation. If PPPD is implementable, then the duodenum is transected 2-3 cm distal to the pylorus. This duodenal cuff must be made long enough to withstand later revision during creation of the duodenojejunal anastomosis.

The gastroepiploic artery and vein are divided, and the right gastric artery is once again identified and protected. The duodenum is divided 2-3 cm distal to the pylorus. The jejunum is transected at least 10 cm distal to the ligament of Treitz. The mesenteries of both transected small-bowel stumps are divided as well, and the duodenum and jejunum are reflected below the mesenteric vessels.

Division of pancreas

The pancreas is transected at the level of the PV, thus exposing the underlying SMV-PV confluence. If the tumor is adherent to the PV, SMV, or SMV-PV confluence, the pancreatic division plane may have to be revised more distally (ie, toward the tail) in order to accommodate vein reconstruction. The tumor is carefully separated from the named venous structures. If the first jejunal branch of the SMV gets injured here, the venous injury is difficult to control, and attempted repair of such an injury can damage the SMA.

The tumor is reflected rightward and separated from the right lateral border of the SMA; it is important to completely resect the uncinate process in order to achieve an R0 resection (ie, surgical margins negative for tumor). The SMA is then exposed by the retracted SMV-PV confluence, and it is dissected carefully to visualize the inferior pancreaticoduodenal artery. This must be ligated securely; failure to do so can cause retroperitoneal hemorrhage.

Removal and orientation of specimen

The specimen is removed en bloc and oriented for pathology. The retroperitoneal margin is inked for pathologic frozen section analysis. A grossly positive retroperitoneal margin represents a technical failure to achieve the intended R0 resection goal. A microscopically positive retroperitoneal margin can occur with 10-20% of pancreaticoduodenal resections for pancreatic head cancer.

Vascular reconstruction

Vascular reconstruction after PPPD is extensive and beyond the scope of this discussion. The reader is directed to the resources in the References section.

Pancreatic reconstruction

The pancreatic remnant is first mobilized along its length for a few centimeters. Then, the transected jejunum is brought through a defect in the transverse mesocolon adjacent to the middle colic vessels. A pancreaticojejunal anastomosis is created with the understanding that pancreatic fistula formation depends on the technical integrity of the anastomosis, as well as the quality of the pancreatic tissue.

A two-layer end-to-side pancreaticojejunostomy, also known as a duct-to-mucosa reconstruction, is performed. This indicates full-thickness pancreatic duct–to–jejunal wall closure.

First, the posterior outer row of interrupted seromuscular sutures is placed between the jejunal side wall and the pancreatic parenchyma. The jejunum is opened longitudinally anterior to this. The inner circumferential layer of interrupted full-thickness sutures reapproximates the cut end of the pancreatic duct with jejunal wall. The posterior sutures are tied inside the anastomosis, a pancreatic stent is placed, and the remaining sutures are tied on the outside. The anterior outer layer of sutures is placed as a row of interrupted seromuscular sutures.

Alternatively, invagination of the distal pancreatic stump into the jejunum can be performed in an end-to-end or end-to-side manner. The inner layer of sutures is placed as described above, and the outer layer of sutures is placed to invaginate the pancreatic remnant. This is useful when the pancreatic duct is not dilated and when the parenchyma is too soft to hold against jejunal seromuscular sutures.

Biliary reconstruction

Hepaticojejunostomy is performed as a one-layer end-to-side anastomosis between the CHD remnant and a site on the jejunum distal to the pancreaticojejunal anastomosis. It is critical to align the bile duct and the jejunum without tension before suture placement.

Enteric reconstruction

The jejunum is traced distal to the biliary reconstruction and brought to lie antecolically. The cuff of duodenum is revised, with preservation of at least 1.5 cm of postpyloric duodenum to maintain the blood supply to the anastomosis. An antecolic end-to-side anastomosis between the duodenum and the jejunum is created with a single layer of continuous suture. Some have found antecolic gastrointestinal (GI) reconstruction to be associated with a lower incidence of delayed gastric emptying (DGE; see Complications) than retrocolic reconstruction ^[10] ; however, others have not. ^{[11, 12]}

Closing maneuvers

A feeding jejunostomy is created distal to the duodenojejunal anastomosis by using a Witzel technique to maintain postoperative enteral feeding access. Then, the falciform ligament is located and used to cover the GDA stump so as to prevent GDA pseudoaneurysm formation in the event of pancreatic leak (see Complications). A vascularized flap of omentum has also been described for coverage of the GDA stump. As a rule, closed-suction transcutaneous drains are placed at the pancreatic anastomosis and biliary anastomosis, with additional drains per surgeon preference. The abdomen is closed in the standard fashion.

A study by Gupta et al suggested that negative-pressure wound therapy (NPWT) may help lower the incidence of surgical-site infection (SSI) after PPPD. ^[13]

Perioperative morbidity

The presence of DGE may necessitate prolonged nasogastric decompression or total parenteral nutrition (TPN) with enteral feeding access failure. ^{[14, 15]} Jejunal feedings should be given for as long as is necessary, with care taken to avoid aspiration.

Pancreatic leak (also called postoperative pancreatic fistula [POPF]) may occur and lead to pancreatic fluid collection, pancreatic fistula formation, ^[16] intra-abdominal abscess, or sepsis.

GDA complications that may develop include pseudoaneurysm resulting in postpancreatectomy hemorrhage (PPH), GDA-enteric fistula, and GDA stump blowout with massive hemorrhage (eg, bleeding from abdominal drains, massive GI bleeding). GDA stump blowout with massive hemorrhage is initiated by inflammation from pancreatic leak and rarely occurs before postoperative day 10. This condition is treated with selective angiography with stenting or embolization of the hepatic artery. Reoperation is performed only as a last resort.

Other perioperative problems include the following:

• Feeding jejunal tube management failures (luminal rotation, dislodgment, obstruction)
• Prolonged ileus
• Small-bowel obstruction
• Internal herniation of bowel
• Small-bowel volvulus
• Critical illness such as sepsis, respiratory failure, GI bleeding, renal failure, and multisystem organ failure
• Death (< 4%)

Long-term morbidity

The following are included in the possible long-term morbidity of PPPD:

• Recurrence of malignancy, such as local recurrence at the retroperitoneal margin or distant recurrence in the liver, peritoneum, or lungs
• Pancreatic insufficiency - Exocrine (~40%), endocrine (~20%)
• Pancreatic anastomotic stricture (recurrent pancreatitis, chronic pancreatic pain)
• Anastomotic failure (any)
• Anastomotic stricture (any)
• Small-bowel obstruction
• Internal herniation of bowel
• Small-bowel volvulus