Pancreaticoduodenecotmy(PD) is considered as the standard procedure for peri-amplullary or pancreatic head tumors. Laparoscopic pancreaticoduodenctomy(LPD) has been reported with minimal invasive advantages, such as small incision, less blood loss, less pain, et al. Further, some trials showed LPD got less morbidity and shorter length of stay. Pancreatic fistula is the major complication for pancreaticodupdenectomy and associated with numerous serious complications, suffering reoperation or sometimes death. The reported rate was 10% to 55%. A lot of modified procedure have been proposed to reduce pancreatic fistula. Omental flaps around anastomosis have been used to prevent post pancreaticoduodenectomy fistula or hemorrhage. However, the outcomes are controversy. A modified omental patch work has been used during LPD and the initial outcomes are good. This is a pilot study to evaluate the function of the modified omental patch work on decreasing the pancreatic fistula.

Inclusion Criteria:

1. . Disease of periampullary or pancreatic head tumor
2. . Age: 18 years or older
3. Distant metastases are not diagnosed preoperatively.
4. . Patients who can provide written informed consent

Exclusion Criteria:

1. . Patients with severe organ disease such as cardiac disease,respiratory illness
2. . Patients with extended LPD or vessels reconstruction
3. Patients with conversion to laparotomy
4. . Patients with pregnancy