clavien_atlas_of_upper_gastrointestinal_and_hepato-pancreato-biliary_surgery2007-10-01_3540200045_springer

Before further mobilization, the pancreas is inspected and palpated carefully. If the tumor is readily apparent on the surface or edge of gland and its location is consistent with preoperative localization studies, further mobilization may be limited to the involved portion of the pancreas, unless there is a familial syndrome or other concerns predisposing the patient to multiple neoplasms.

For tumors in the head and uncinate region, the duodenum is widely Kocherized out to and including the ligament of Treitz; division of the right gastroepiploic vessels on the anterior surface of the pancreatic head and the anterior inferior pancreatoduodenal vein to the uncinate facilitates exposure of the head and uncinate and reduces the risk of inadvertent vascular injury and bleeding during further dissection; transpancreatic palpation of the head and uncinate allows localization of tumors in this region.

STEP 3

When the tumor is in the neck of the pancreas, a plane is developed between the underside of the neck of the gland and the underlying portal vein – the superior mesenteric vein junction. After exposing the superior mesenteric vein at the inferior edge of the neck of the pancreas, gentle blunt dissection with an index finger or a small cherrytipped sucker completes the dissection under direct vision; care is taken to stay directly on top of the vein throughout the dissection to avoid injury to lateral venous tributaries to the uncinate. In patients with insulinoma, this is usually an easy dissection.

STEP 4

When the tumor is in the body of the pancreas, dissection continues along the avascular inferior border of the body of the gland. After incising this plane, the body of the pancreas is mobilized from the inferior to superior border (A-1).

When the tumor is in the tail of the pancreas, mobilization of the spleen by incising its lateral peritoneal attachments to the kidney and diaphragm usually allows best exposure. Short gastric vessels are not divided until the decision is made regarding splenic-preservation (A-2).

When the tumor is occult, all these maneuvers should be performed prior to intraoperative ultrasonography (IOUS); bimanual and bidigital palpation allow the gland to be examined from head to tail; suspicious lymph nodes are excised for frozen section analysis (A-3).

Real-time IOUS is next performed using a 6-mHz transducer in the longitudinal and transverse axes. Islet cell neoplasms appear as hypoechoic masses within the pancreatic parenchyma, are more firm in texture than the surrounding parenchyma, and are tan to reddish-brown.

Islet cell neoplasms typically have a rim of vascular enhancement not seen with lymph nodes on color-flow Doppler examination.

Further palpation of lesions on ultrasonography often reveals subtle thickening within the pancreas not appreciated during the initial exploration.

If doubt of the findings exists, ultrasonography-guided fine-needle aspiration provides immediate cytologic evaluation; this is especially important for occult islet cell neoplasms deep within the head of gland abutting the pancreatic and/or bile ducts; this situation requires pancreatoduodenectomy, and absolute cytologic confirmation of an islet cell neoplasms is essential.

STEP 4 (continued)

A-2

For palpable tumors on the edge of the gland, anterior surface, or posterior surface, the very thin operculum of pancreatic tissue overlying the tumor is carefully incised using a combination of bipolar cautery and a fine-tipped hemostat, the underlying insulinoma exposed, and a traction suture is placed deep into the tumor in figure-of- eight fashion to avoid fracture. Constant gentle elevation of the traction suture allows direct visualization of the small feeding vascular tributaries, which can be managed with bipolar cautery but infrequently require fine metallic clips. The pancreatic parenchyma is dissected away from the tumor using a fine endarterectomy spatula. Near the base of the enucleation, the endarterectomy spatula really helps to push the parenchyma away from the adenoma, especially when enucleating tumors are abutting the pancreatic duct.

Once enucleation is complete, ultrasonography confirms the integrity of the main pancreatic duct. In the past, secretin was administered to dilate the pancreatic duct to demonstrate major leaks from the enucleation site.

A nasogastric tube and Foley urinary catheter are put in place. Prophylactic parenteral antibiotics are given.

The patient is positioned in the lithotomy position with a wedge under the left flank (45° of elevation).

The surgeon stands between the patient’s legs, the first assistant to patient’s right, and the scrub nurse to the patient’s left.

Two monitors are positioned at each of the patient’s shoulders.

A five-trocar technique is used (10-mm trocar at umbilicus for 10mm, 30° laparoscope); the size and position of the other four trocars vary with patient habitus, but a 12-mm trocar in the left mid-axillary line is used to introduce the linear stapler.

Endoscopic ultrasonography is performed routinely; the aim is to localize the tumor, define resection margin, exclude secondary lesion (both hepatic or pancreatic), and define the relationship with the main vessels and pancreatic duct.

The probe we use fits through a 10-mm trocar; its tip can be angulated for maximal surface contact. For small lesions, a water balloon is placed between the probe and the pancreatic body to improve resolution.

The ideal treatment is enucleation; however, with a larger tumor or one deep or localized too close to the main vessels or pancreatic duct, a pancreatic tail resection, with or without splenectomy, is preferred.