Perioperative management - Gastrectomy

• Primary gastric carcinoma
• Carcinoma in the operated stomach
• Individually for resectable metastases, local peritoneal carcinomatosis (P1), recurrent tumors (gastric stump carcinoma)
• In the case of a curative treatment approach and local resectability, there is basically an indication for surgery provided no massive risk factors are present (pre-existing conditions or general condition of the patient, see contraindications)
• In the case of locally advanced tumors, pre-/peri-operative chemotherapy should be performed
• In the case of a palliative treatment approach, gastrectomy may be indicated in rare cases (e.g., bleeding, perforation, stenosis).

To achieve tumor-free resection margins (R0), except in mucosal carcinomas (T1a N0 M0), a proximal safety margin at the stomach of 5 cm (intestinal type acc. to Lauren) or 8 cm (diffuse type acc. to Lauren) in situ must generally be maintained. The lymph node dissection of compartments I and II is referred to as D2-LAD and represents the standard lymphadenectomy for gastric carcinoma. It can be considered the gold standard.

The extent of resection (total versus subtotal gastrectomy) is determined by tumor location/extension and the safety margin required by the histological type.

Special situation early gastric carcinoma
Early gastric carcinoma is defined as a tumor that, regardless of lymph node status, surface extension, and distant metastasis, is limited to the mucosa and submucosa of the gastric wall. By definition, the muscularis propria of the stomach is tumor-free.

Differences are seen in early carcinomas in the frequency of potential lymph node metastasis. Tumors that have already infiltrated the submucosa are not considered for endoscopic therapy, as lymph node metastases are to be expected with a probability of 4-20%. 

Around 5% of patients show an early gastric carcinoma of the mucosal type (pT1m), in which a curative treatment approach through endoscopic resection is possible, as the probability of lymph node metastasis is extremely low. Affected patients have an excellent prognosis with a five-year survival rate of > 90 %.

Indications for endoscopic resection
Superficial gastric carcinomas limited to the mucosa (about 5% of patients) can be treated with endoscopic resection taking into account the following criteria:

• Lesions of < 2 cm size in elevated types
• Lesions up to 1 cm size in flat types
• Histological degree of differentiation: well or moderately (G1/G2)
• No macroscopic ulceration
• Invasion limited to the mucosa

In the presented case, it is a 5 cm large ulcerated gastric tumor at the greater curvature, transition from middle to distal third of the stomach. Histologically, it is a gastric carcinoma of the intestinal type according to Lauren, endosonographically uT2, no evidence of lymph node or distant metastases in tumor staging. Therefore, indication for gastrectomy with D2 lymphadenectomy.

• Reduced general condition (e.g. due to tumor cachexia)
• Relevant comorbidities with inability to undergo surgery or anesthesia
• Irresectable tumor with proximal infiltration of the superior mesenteric artery or the celiac trunk 
• Any form of metastasis, except if the metastasis can be completely remedied as R0 resection (e.g. locally limited peritoneal carcinomatosis, solitary liver metastasis, solitary distant lymph node metastasis).
• Portal vein thrombosis or other diseases with pronounced venous collateral circulations (liver cirrhosis).
• In case of passage obstruction or endoscopically uncontrollable tumor bleeding, gastrectomy may be indicated as a palliative procedure if necessary.

mandatory:

• Blood chemistry laboratory tests with so-called tumor markers (CA 72-4, CA 19-9, CEA)
• Esophagogastroduodenoscopy with step biopsies (at least 8 PE's)
• Ultrasound of the abdomen including the pelvis; according to S3 guidelines, the first imaging procedure for assessing liver metastases.
• Endosonography for assessing the T-stage, particularly for evaluating early gastric carcinoma (mucosa/submucosa type). Identification of risk constellations uT3/4 N+ or detection of perigastric ascites. Assessment of lymph nodes in category N1 – 2 is possible, but with limited sensitivity and specificity. 
• Thorax and abdomen CT (with i.v. contrast medium)

Optional:

• Staging laparoscopy in advanced gastric carcinomas (cT3/cT4) to improve staging accuracy. It alone can detect previously unknown small subcapsular liver metastases or occult peritoneal carcinomatosis, possibly plus IOUS (intraoperative ultrasound) and PE (probe excision).
• A peritoneal lavage with cytology can be performed additionally.
• MRI should be reserved for patients in whom no CT can be performed.
• PET-CT is not routinely recommended for staging of gastric carcinomas.

According to the S3 guidelines, neoadjuvant chemotherapy is an integral part of the treatment concept for gastric carcinoma.

Upon diagnosis of gastric carcinomas in stages II and III (cT1/cT2N+ as well as cT3/resectable cT4Nx), “should/shall” according to the current guideline, a perioperative chemotherapy should be performed. This is classically started preoperatively (neoadjuvant) and continued postoperatively. This can increase the R0 resection rate, reduce the systemic recurrence rate, and improve the overall prognosis.

For planned preoperative chemotherapy (T3/4)

1. Port implantation
2. laparoscopic exploration optional
3. if necessary, stent insertion for dysphagia

For planned resection

If necessary, initiate preoperative nutritional therapy in patients who have lost significant weight preoperatively.

(on the day before surgery)

1. Diet form: clear broth
2. laxative measures
3. current blood chemical laboratory examination, determine blood group and order erythrocyte concentrates
4. Thrombosis prophylaxis (LMWH (Low Molecular Weight Heparin), anti-thrombosis stockings) (see guideline on thrombosis prophylaxis in section 1.10).

General Surgical Risks:

• Thrombosis, Pulmonary Embolism
• Pneumonia
• Heparin Intolerance, HIT
• Urinary Tract Infection

Specific Surgical Risks:

• Lethality between 2 and 10%
• Final decision on the resection procedure only intraoperatively
• Injury to internal vessels and organs (including pleura!)
• Anastomotic Insufficiency
• Duodenal Stump Insufficiency
• Endoluminal / Intra-abdominal Bleeding
• Reduced Blood Flow to the Replacement Stomach
• Intra-abdominal Abscess, Peritonitis
• Pancreatitis or Pancreatic Fistulas
• Wound Healing Disorder
• Incisional Hernia

Possibly Required Extension of the Procedure:

• Cholecystectomy
• Resection of Liver Metastases
• Splenectomy

Notes on:

• Temporary Weight Loss
• Changed Eating Habits
• Drains, Gastric Tube, Urinary Drainage
• Possibly Blood Transfusion