Overview
Definition:
Splenic hilum dissection in the context of gastric cancer surgery refers to the meticulous separation and removal of the splenic artery, splenic vein, and associated lymph nodes (Group 10, pancreatico-splenic lymph nodes) from the splenic hilum during radical gastrectomy
This step is crucial for achieving adequate lymphadenectomy, particularly for advanced gastric cancers involving or adjacent to the spleen, or those with a risk of distal metastasis.
Epidemiology:
Gastric cancer remains a significant global health challenge, with a higher incidence in East Asia
While not all gastric cancers require splenic hilum dissection, its necessity arises in approximately 15-25% of cases, particularly those with tumors located in the gastric cardia or fundus, or those with evidence of regional lymph node involvement in the splenic hilum
The incidence of splenic metastasis from gastric cancer is relatively low but can occur in advanced stages.
Clinical Significance:
Adequate lymph node dissection is paramount for accurate staging and effective oncologic treatment of gastric cancer
Dissection of the splenic hilum is essential for removing metastatic lymph nodes (Group 10) that could otherwise be missed, leading to incomplete staging and potential locoregional recurrence
Furthermore, understanding the anatomy and technique is vital to avoid iatrogenic injury to surrounding structures like the spleen, pancreas tail, and major blood vessels, which can lead to significant morbidity
Mastery of this technique is a key skill tested in surgical residency examinations like DNB and NEET SS.
Indications
Gastric Cancer Staging:
Tumors involving the gastric cardia or fundus
Tumors with direct invasion or proximity to the splenic hilum.
Lymph Node Metastasis:
Clinically or radiologically suspected lymph node metastasis in the splenic hilar region (Group 10 nodes)
Positive intraoperative frozen section of hilar nodes.
Risk Of Metastasis:
Advanced stage gastric cancers (T3/T4) with higher risk of lymphatic spread to regional nodes
Tumors with poor prognostic features.
Spleen Involvement:
Rare cases where the tumor directly involves or infiltrates the spleen, necessitating its removal along with the stomach (gastrosplenic resection).
Surgical Anatomy And Technique
Anatomy Of Splenic Hilum:
The splenic hilum is the central region where the splenic artery and splenic vein enter and exit the spleen
It is surrounded by lymph nodes (Group 10) and is intimately related to the tail of the pancreas and the posterior surface of the stomach
The splenic artery originates from the celiac trunk, and the splenic vein drains into the portal vein.
Preoperative Preparation:
Thorough preoperative imaging (CT scan, EUS) to assess tumor extent and lymph node involvement
Prophylactic antibiotics
Assessment of patient's cardiopulmonary status
Informed consent detailing potential splenectomy and its consequences.
Surgical Approach And Dissection:
Typically performed as part of a total gastrectomy
The gastrocolic ligament is divided, and the greater curvature is mobilized
The splenic artery and vein are identified and carefully dissected
Mobilization of the pancreatic tail is often necessary to achieve complete dissection of the pancreatico-splenic lymph nodes
The dissection progresses from anterior to posterior, staying close to the vessels and nodes to avoid damaging the pancreas or spleen
Careful ligation of the splenic artery and vein is crucial.
Lymphadenectomy Extent:
Includes en bloc removal of the stomach, perigastric lymph nodes (Groups 1, 2, 3, 4, 5, 6, 7, 8, 9), and the pancreatico-splenic lymph nodes (Group 10)
The extent of dissection (e.g., D1, D2, D2+b) depends on the tumor location and stage, with D2+b often including Group 10 nodes.
Complications
Pancreatic Fistula:
Injury to the pancreas during mobilization or dissection of the splenic hilum can lead to pancreatic fluid leak
Risk is higher if the pancreatic tail is involved.
Splenic Infarction Or Bleeding:
Incomplete ligation or injury to the splenic artery or vein can result in infarction or significant bleeding
Accidental injury to the spleen itself is also possible.
Hemorrhage:
Major vascular structures in the hilum are prone to bleeding
Postoperative bleeding can also occur from the operative site.
Post Splenectomy Sepsis:
Loss of splenic function increases the risk of overwhelming post-splenectomy infection (OPSI), particularly from encapsulated bacteria (e.g., Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis)
Vaccination before elective splenectomy is recommended.
Postoperative Care And Follow Up
Monitoring:
Close monitoring of vital signs, fluid balance, and drain output
Serial monitoring of amylase levels to detect pancreatic leaks
Watch for signs of bleeding or infection.
Nutritional Support:
Early initiation of enteral or parenteral nutrition as appropriate, especially after total gastrectomy
Management of dumping syndrome if it occurs.
Splenectomy Management:
Patient education regarding the increased risk of infection
Advice on prompt medical attention for fever or signs of infection
Vaccination against encapsulated organisms is crucial
Lifelong antibiotic prophylaxis may be considered in high-risk individuals.
Key Points
Exam Focus:
Understanding the indications for splenic hilum dissection in gastric cancer
Mastery of the anatomy of the splenic hilum and surrounding structures
Knowledge of potential complications and their management
Recognizing the importance of Group 10 lymphadenectomy for accurate staging in selected cases.
Clinical Pearls:
Always confirm vascular control before dividing the splenic artery and vein
Gentle mobilization of the pancreatic tail is key to preventing injury
Use meticulous dissection techniques to avoid inadvertent damage to the spleen or pancreas
Consider frozen section for suspicious hilar nodes.
Common Mistakes:
Failure to identify or dissect Group 10 lymph nodes when indicated, leading to understaging
Excessive or blunt dissection causing pancreatic tail injury
Inadequate control of the splenic artery or vein leading to hemorrhage
Forgetting to counsel patients about post-splenectomy infection risk.