Traditionally, laparoscopy has been based on 2-dimensional (2D) imaging, which has represented a considerable challenge for those approaching this technique. Thus, 3-dimensional (3D) visualization technology for laparoscopy has been proposed, since the early 1990s, as a way to facilitate laparoscopic performance. However, early 3D laparoscopic technology was limited in terms of image quality, so that its use had not been implemented. More recently, industry has developed novel 3D systems where the imaging is similar to stereoscopic vision, in which the depth perception is achieved by different unique images received by each eye. Thus, more recent studies have suggested a possible advantage provided by these new 3D systems during laparoscopic performance. However, comparative assessments of new generation 3D vs 2D laparoscopy remain limited, especially in the hepatobiliary and pancreatic field.

To assess the benefits and harms of use of three dimensional systems versus two dimensional systems during laparoscopic distal pancreatectomy.

Procedures

1. the investigators will take the patient consent for this clinical trial.
2. The participants will be divided with two groups with block randomized method
3. Skillful pancreatic surgeon will perform 2D or 3D laparoscopic distal pancreatectomy.
4. The participants will be monitor the intraoperative and postoperative course.

Data collection

1. operation video : operation time, number of errors (missed grasp, loss of material)

   1. Segmental operation time according to procedure
   2. Numbers of errors during operation

2. clinical parameters:

   1. Blood examination : complete blood count (hemoglobin, white blood cell count), amylase, lipase, etc.
   2. Radiological examination: X-ray, Computed Tomography (CT), Magnetic Resonance Imaging (MRI), etc
   3. Medical records : hospital stay after operation, the time to eating, pathologic examination

3. Subjective scoring in the view of operator, 1st assist.

   1. Scoring for imaging quality
   2. Scoring for harms of 3D/2D laparoscopic system
   3. Scoring for overall demand

Inclusion Criteria:

• BMI > 30 (Kg/m2)
• History of severe or recurrent pancreatitis
• Mass size > 10cm
• History of low abdomen major operation
• Additional resection for extra-pancreatic organ

Exclusion Criteria:

• Participants refusal.
• Additional resection dependent on pathological examination in intraoperative or postoperative period.