Lymph Node Stations in Pancreaticoduodenectomy
Standard lymphadenectomy during pancreaticoduodenectomy should include specific peripancreatic stations (5,6, 8a, 12b, 12c, 13a, 14a, 14b, 17a, 17b) with removal of at least 15 lymph nodes, while extended retroperitoneal lymphadenectomy beyond these stations is not recommended as it provides no survival benefit. 1
Standard Lymph Node Stations for Pancreaticoduodenectomy
The ESMO guidelines clearly define the following lymph node stations that should be resected during standard pancreaticoduodenectomy: 1
Peripancreatic and Regional Stations:
- Station 5: Suprapyloric lymph nodes 1
- Station 6: Infrapyloric lymph nodes 1
- Station 8a: Anteriosuperior group along the common hepatic artery 1
- Station 12b: Along the bile duct 1
- Station 12c: Around the cystic duct 1
- Station 13a: On the posterior aspect of the superior and inferior portion of the head of pancreas 1
- Station 14a and 14b: On the right lateral side of the superior mesenteric artery (SMA) 1
- Station 17a: On the anterior surface of the superior portion of the head of pancreas 1
- Station 17b: On the anterior surface of the inferior portion of the head of pancreas 1
Minimum Lymph Node Harvest Requirement
At least 15 lymph nodes must be removed and examined to allow adequate pathologic staging. 1 The pathology report should document both the total number of lymph nodes examined and the lymph node ratio (number of involved lymph nodes divided by total number examined). 1
Extended Lymphadenectomy: Not Recommended
Extended lymphadenectomy beyond standard stations should not be performed routinely. 1 The NCCN guidelines explicitly state that current evidence does not support extended lymphadenectomy as a routine component of the Whipple procedure. 1
Evidence Against Extended Lymphadenectomy:
The definition of extended lymphadenectomy typically includes removal of peripancreatic nodes plus retroperitoneal soft tissue from the hilum of the right kidney to the left lateral border of the aorta in one axis, and from the portal vein to the origin of the inferior mesenteric artery in the other. 1
Two prospective randomized trials definitively addressed this question: 1
The Italian Multicenter Lymphadenectomy Group randomized 81 patients to standard versus extended lymphadenectomy and found no survival advantage for extended dissection. 1, 2
A larger Johns Hopkins trial with 299 patients showed no difference in operative mortality or median survival at 1,3, and 5 years between groups, though extended dissection resulted in longer operative times. 1
Limited Exceptions for Extended Dissection:
Extended lymphadenectomy may be considered only in highly selected circumstances: 1
- Patients with larger tumors where extended dissection might facilitate margin-negative resection 1
- Reoperative cases where removing retroperitoneal nodal tissue allows dissection in a virgin plane 1
- Within the context of a clinical trial 1
The rationale for avoiding routine extended dissection is that nodal metastases represent a marker of systemic disease, and their removal is unlikely to alter overall survival. 1
Emerging Considerations for Station 14cd
Recent research suggests that dissection of lymph nodes on the left posterior aspect of the SMA (stations 14c and 14d) may have clinical value, with a positive rate of 31.1% in pancreatic head cancer. 3 This dissection can increase lymph node staging accuracy and may change TNM staging in approximately 5-6% of patients. 3 However, this has not yet been incorporated into major international guidelines and requires further validation.
Critical Technical Points
Dissection of the right hemi-circumference of the SMA (to the right of the celiac trunk) is recommended to obtain good medial clearance and improve R0 resection rates. 1 This differs from extended lymphadenectomy and represents standard oncologic technique during pancreaticoduodenectomy. 1