Surgery of the pancreas: Minimally invasive approaches

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Chapter 62B Surgery of the pancreas

Minimally invasive approaches

Overview

In recent years, an increasing number of laparoscopic pancreatic surgical procedures have been performed and reported from centers around the world. Even operations that were once considered impossible to perform laparoscopically, such as pancreatoduodenectomy or segmental pancreatic resection, are gaining momentum in a number of centers. With improving surgical techniques and experience, it has become crucial to reevaluate proper indications for laparoscopic pancreatic surgery. Limitations for a minimally invasive approach are often due to technical difficulties and particularly to the characteristics of pancreatic diseases.

Open pancreatic resection is commonly performed through an upper abdominal incision, whereas laparoscopic pancreatic resection is performed through four or five small abdominal incisions. The exposure during open pancreatic surgery involves the use of abdominal wall retractors and mechanical retraction of the abdominal viscera. In contrast, exposure during laparoscopic pancreatic resection is achieved with pneumoperitoneum. By reducing the length of surgical incisions and eliminating the need for mechanical retraction of the abdominal wall and viscera, operative trauma to the abdominal wall during laparoscopic pancreatic surgery can be minimized. However, the lack of direct haptic feedback, fewer degrees of freedom, a narrow working space, and a sometimes difficult orientation conspire to limit the indications for laparoscopic pancreatic surgery. Moreover, the intraabdominal surgical trauma is identical to the open technique and exceeds by far the relatively minor trauma to the abdominal wall. Within this context, the relative benefits of laparoscopic pancreatic resection must be examined critically.

Laparoscopic pancreatic surgery represents one of the most sophisticated applications for laparoscopy currently in use. Recent advances in technology and techniques have opened new gates to a wide range of applications in patients with pancreatic diseases. This chapter describes the laparoscopic techniques available today, including diagnostic laparoscopy, laparoscopic resection techniques, and new technical developments such as robotic approaches.

Diagnostic Laparoscopy

Diagnostic laparoscopy is a procedure that allows the surgeon to examine directly the contents of a patient’s abdomen or pelvis, including the peritoneum, small bowel, large bowel, liver, pancreas, or gallbladder (see Chapter 21). Pancreatic cancer is characterized by an aggressive, infiltrating local tumor growth and early manifestation of metastasis. Consequently, resection with curative intent can be performed in only 10% to 20% of patients with newly diagnosed pancreatic cancer.

Although staging of pancreatic cancer is critical to the planning of therapy and has improved over the past decades, especially as a result of better imaging techniques, there are still some patients in whom liver or peritoneal metastases are not detected during preoperative testing. Even with modern thin-sliced computed tomography (CT) or magnetic resonance imaging (MRI), detecting hepatic or peritoneal metastases smaller than 5 mm is difficult and often impossible. Likewise, assessing local tumor extent and the degree of infiltration into adjacent organs remains challenging. In these cases, diagnostic laparoscopy is useful for assessing whether the patient is a candidate for curative resection or radiotherapy. In addition to the possibility of obtaining peritoneal fluid for cytology, following instillation of saline into the peritoneal cavity, laparoscopic ultrasonography (US) can be performed. This technique enables the detection of locally advanced disease and intraparenchymal liver involvement and gives a good indication of vascular involvement (Menack et al, 2001). Consequently, in many cases a primarily planned surgical pancreatic resection can be aborted with minimal surgical trauma. At the same time, tissue samples for histologic evaluation can be achieved from distant metastases and from large tumors, particularly when the body or tail of the pancreas is involved.

Overall, the indications for a staging laparoscopy in pancreatic cancer are 1) large primary lesions in the neck, body, or tail of the pancreas; 2) radiographic findings suggestive of occult metastases or a possible carcinomatosis; 3) small, hypodense regions in the hepatic parenchyma suspicious for liver metastases; and 4) subtle clinical and laboratory findings suggesting more advanced disease (Pisters et al, 2001). In eliminating nontherapeutic laparotomy and redirecting treatment plans, laparoscopy contributes significantly both to the proper management of patients with pancreatic cancer and to increased efficiency of resource utilization (Warshaw et al, 1986).

history of Laparoscopic Pancreatic Surgery (See Chapter 62A)

The slow progress of laparoscopy in pancreatic surgery in the past has been attributed to the retroperitoneal location of the gland, its proximity to various important vascular structures and organs, the friable nature of the gland, and the difficulty in its exposure. Similar to experiences with sigmoid colon resections, which were first performed in benign diseases such as recurrent sigma diverticulitis, laparoscopic pancreatic resections were initially performed for benign tumors. In particular, benign endocrine tumors less than 1 cm (e.g., insulinomas) or small cystadenomas predominantly located in the distal body and tail of the pancreas were ideally suited for the laparoscopic approach. In such cases, the surgical specimen is relatively small and contrasts greatly with the size of the abdominal incision required to access this retroperitoneal gland at conventional open surgery. Furthermore, enucleation or atypical resection can often be performed to remove small pancreatic lesions without the need for an anastomosis (Ammori, 2003).

Currently, laparoscopic resection can be performed both for benign and malignant pancreatic diseases. For benign tumors, left resections or enucleations can be often performed without difficulty. On the other hand, resections that require an anastomosis or those for malignant tumors that require an adequate margin and associated lymph node dissection remain tremendously challenging. Because lymphadenectomy in pancreatic cancer is technically difficult, especially along the celiac trunk and the superior mesenteric artery, few surgeons perform laparoscopic resections for malignant disease on a routine basis. Although many reports have demonstrated technical feasibility, it must be stated that not everything that can be done should be done. Sophisticated pancreatic resections such as pancreatoduodenectomy are only performed in highly select cases by exceptionally skilled laparoscopic surgeons to achieve a satisfying postoperative outcome (Gagner & Palermo, 2009). Because the challenge in pancreatic surgery for malignant disease is to achieve an R0 resection, even in advanced cases requiring vascular and/or multivisceral resections, we feel that the potential benefit of laparoscopic resections does not outweigh the risk in patients with cancer.

Laparoscopic Pancreatic Resections

Pancreatic Left Resection

Surgical Technique

Distal pancreatic resection has been performed for the treatment of patients with chronic pancreatitis and benign and malignant tumors in the tail or body of the pancreas. Initially, distal pancreatectomy was performed en bloc with the resection of the spleen. This technique was preferred by surgeons for technical as well as oncologic reasons. Because resection of the spleen has been reported to impair the immune system and could predispose to infective complications after distal pancreatectomy and splenectomy (Holdsworth et al, 1991), Kimura and colleagues (1996) developed a technique of preserving both the splenic artery and vein. In addition, Warshaw (1988) described a technique of distal pancreatectomy in which splenic vessels are ligated both at the level of transection of the pancreas and again at the splenic hilum, leaving the spleen to survive on blood flow through the short gastric vessels.

Over the past few years, the technique of laparoscopic pancreatic left resection has been introduced and refined. Many different methods have been described for trocar placement and surgical technique. In the technique used in Heidelberg, the patient is placed in a half-lateral position with the left side up. The surgeons stand on the right side of the patient, and the camera operator and scrub nurse stand on the opposite side. Four 10- to 12-mm trocars are inserted in the abdominal wall 3 to 4 cm above the umbilicus on the xiphoid area, subcostal on the midaxillary line, and subcostal to the midclavicular line. The first step is dissection of the splenorenal ligament; the splenic flexure of the colon is then mobilized downward. The gastrocolic omentum is widely opened along the gastroepiploic arcade up to the level of the mesenteric vessels, and the body and tail of the pancreas are then visualized (Fig. 62B.1

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