Perioperative management - Total laparoscopic gastrectomy with D2 lymphadenectomy

Surgical treatment is the only curative option and standard therapy for all potentially resectable gastric cancers. It generally entails radical resection of the primary tumor in healthy tissue (R0 resection at all levels: proximal, distal and circumferential) and systematic regional lymphadenectomy (LAD). In order to achieve tumor-free resection margins (R0), a proximal safety margin in situ at the stomach of 5 cm in Lauren intestinal type and 8 cm in Lauren diffuse type cancer must generally be maintained, except in mucosal carcinoma (T1aN0M0). Lymph node clearance of compartments I and II is referred to as D2-LAD and is the standard lymphadenectomy in gastric cancer. It is regarded as the gold standard.

The extent of resection (total versus subtotal gastrectomy) is determined by tumor location/spread and the safety margin necessitated by the histologic type.

Total gastrectomy with D2-LAD is indicated for the following:

• All potentially resectable gastric cancers except for mucosal cancers suited to endoscopic resection. 
• Gastric remnant cancer

Endoscopic resection in early gastric cancer
As early as 1962, the Japanese Research Society for Gastric Cancer defined early gastric cancer as a tumor confined to the gastric mucosa and submucosa, irrespective of lymph node status, spread, and distant metastasis. By definition, the gastric tunica muscularis is tumor-free.

Based on the Japanese Research Society for Gastric Cancer, early gastric carcinoma is differentiated macroscopically into following tumor types: protruding (type I), superficial (type IIa-c), and excavated (type III).

Early cancers differ in terms of their potential lymph node metastasis rates. There is evidence to suggest that type I and type II tumors will have already infiltrated the submucosa more so than type III tumors and thus are not candidates for endoscopic resection. For example, in the mucosal type lymph node metastasis is present in around 0–3% of cases, and in the submucosal type in around 4–20%, compared to 80% in locally advanced gastric cancer.

Around 5% of patients present with early mucosal-type gastric cancer (pT1m), where a curative therapeutic approach with endoscopic resection is possible as the probability of lymph node metastasis is extremely low. These patients have an excellent prognosis with a five-year survival rate of >90%.

Accurate histopathologic staging in early gastric cancer can be obtained by endoscopic mucosal resection (EMR), endoscopic submucosal dissection (ESD), or laparoscopic partial resection of the gastric wall, as all of these modalities are both minimally invasive diagnostic as well as therapeutic options. If histology confirms submucosal cancer, surgical resection and systematic lymphadenectomy must be performed because the risk of lymph node metastasis increases significantly.

Indications for endoscopic resection
Superficial gastric cancer confined to the mucosa and meeting the following criteria can be treated by endoscopic resection (based on the Japanese classification of gastric cancer):

• Protruding tumors <2 cm in size
• Superficial tumors 1 cm in size
• Histologic grading: well or moderately differentiated (G1/G2)
• No gross ulceration
• Invasion confined to mucosa

• Significant comorbidity with unfitness for anesthesia and/or surgery
• Unresectable tumor, e.g., with extensive invasion of the posterior peritoneum and large vessels such as hepatic artery, celiac trunk, and abdominal aorta
• Any metastasis, except those cases where total R0 resection can be achieved (e.g., local peritoneal carcinomatosis, solitary liver metastasis, and solitary lymph node metastasis)

Gastrectomy may be indicated for palliation in cases of impaired gastric transit or endoscopically uncontrollable tumor hemorrhage.

Mandatory:

• Esophagogastroduodenoscopy with multilevel sampling (at least 8 biopsies)
• Ultrasonography of the abdominal cavity including the lesser pelvis; according to the German S3 guidelines the primary imaging modality for assessment of liver metastases
• Endosonography for T-staging, especially when assessing early gastric cancer (mucosal/submucosal type). Assessment of N1and N2 lymph nodes is possible, but with limited sensitivity and specificity.
• CT studies of the chest and abdomen (with i.v. contrast enhancement)

Optional:

• Staging laparoscopy in advanced gastric cancer to detect distant metastases and peritoneal carcinomatosis. In addition, any staging laparoscopy should always entail a peritoneal lavage for cytology.
• MRI should be reserved for those patients for whom computed tomography is not possible
• In the absence of corresponding clinical symptoms, bone scintigraphy is not indicated in staging
• Routine PET-CT imaging is not recommended when staging gastric cancer
• Barium swallow tests are not suitable for staging tumors of the stomach or esophagogastric junction. Endoscopy and CT reconstructions can adequately answer the question of tumor location.
• There is no evidence that tumor markers (e.g., CEA, Ca19-9, and Ca72-4) provide any benefit. All these markers suffer from inadequate sensitivity and specificity for primary diagnostic staging. While various molecular markers correlate with the prognosis of gastric cancer, they have not yet gained clinical importance in therapeutic decision making so far.

Perioperative chemotherapy
According to the current German guideline, diagnosed uT3 and resectable uT4a gastric cancers “shall/should” undergo perioperative chemotherapy. This is normally instituted before surgery (neoadjuvant) and continued postoperatively.

If necessary, initiate nutritional support before surgery in patients with marked preoperative weight loss.

Blood group typing, provision of packed RBCs

General risks of surgery:

• Thromboembolism
• Pneumonia
• Urinary Tract Infection
• Heparin intolerance (heparin induced thrombocytopenia - HIT)

Special surgical risks:

• Definitive decision regarding the actual resection procedure only possible during surgery
• Injury to internal vessels and organs, e.g., spleen, bile duct, hepatic artery
• Staple line failure
• Staple line failure of duodenal remnant
• Endoluminal / intra-abdominal bleeding
• Intra-abdominal abscess, peritonitis
• Pancreatitis and pancreatic fistulas
• Secondary healing
• Incisional hernia

Possible need for extended surgery

• Cholecystectomy
• Resection of liver metastases
• Splenectomy

Information about:

• Temporary weight loss
• Changing eating habits
• Drains, gastric tube, urinary catheter
• Possibly, allogeneic blood transfusion