Intraoperative Care of the Surgical Patient: Upper Gastrointestinal Cancers

Introduction

The upper gastrointestinal (GI) tract comprises the mouth, esophagus, stomach, and duodenum. The incidence of such cancers is rising, and improved operative safety and successes of neoadjuvant chemotherapy have increased the number of patients who are candidates for curative resection. Resection of tumors involving the upper GI tract carries high intraoperative risk, and due to shared anatomy, close concert between the anesthesiologist and surgeon. The goals of intraoperative management include optimal fluid management, appropriate multimodal analgesia, reduction of postoperative pulmonary complications, and optimizing the physiologic milieu to promote anastomotic healing.

Chemotherapeutic Toxicity

Patients receiving neoadjuvant chemotherapy for upper esophageal cancer may suffer from chemotherapeutic toxicity of which the intraoperative team should be aware. Chemotherapeutic agents can cause dysrhythmias (anthracycline, pembrolizumab), myocarditis (cyclophosphamide, busulfan), dilated cardiomyopathy (doxorubicin), and prolonged QT interval (oxaliplatin, tamoxifen, anthracycline, 5-fluorouracil, paclitaxel). Patients receiving these agents may have pericardial effusions, restrictive cardiomyopathy, and congestive heart failure. All patients who have received chemotherapy agents and who express symptoms of dyspnea on exertion should receive a preoperative echocardiogram to screen for cardiomyopathy.

Esophageal Cancer

Epidemiology

The incidence of esophageal cancer in the United States is 0.7% in men and 0.2% in women, making it the 18th most common type of cancer and the 11th in terms of risk of death. Ninety-five percent of esophageal cancers are squamous cell carcinoma (SCC) and adenocarcinoma. The incidence of adenocarcinoma, once considered to be quite rare, now accounts for more than 60% of esophageal cancers, largely due to the increase in incidence of Barrett's esophagus. In southern and eastern Africa and eastern Asia, the incidence of esophageal cancer is much higher and predominantly due to SCC. Small cell cancers, leiomyosarcomas, leiomyomas, and GI stromal tumors account for a very small portion of esophageal cancers. Due to improved treatment modalities, the 5-year survival rate has increased from 5% in the 1960s to 20% in the modern day.

Behavioral risk factors for squamous cell esophageal cancer include smoking and alcohol consumption. Dietary factors include red meat consumption, low fiber diets, hot beverage consumption, zinc deficiency, and selenium deficiency. History of achalasia or caustic injury are additional predisposing factors. Human papilloma virus (HPV) has not been definitively linked to esophageal cancer. The increasing prevalence of adenocarcinoma is linked to higher rates of obesity, gastroesophageal reflux disease, and diets low in fruits and vegetables. A history of Barrett's esophagus increases the risk of developing esophageal cancer by 30-fold. Adenocarcinoma is more prevalent among Caucasians, and six times more prevalent in males than females.

The most common location of SCC in the esophagus is at the midportion, arising from small plaques that can be missed on endoscopy. Local lymph node infiltration occurs early due to the close proximity of the lymph nodes to the lamina propria of the esophagus. It eventually progresses to invade adjacent organs, including the celiac artery and aorta, which can present with massive upper GI bleeding.

Adenocarcinoma most commonly arises in the gastroesophageal junction and most commonly spreads to the celiac and perihepatic nodes.

Diagnosis and Staging

Early esophageal cancer is usually asymptomatic and only detected during endoscopy for alternative purposes or during surveillance for Barrett's esophagus. Symptoms for more advanced cancers are usually dysphagia (often manifested in the early stage by the “sticking” of hard foods), weight loss, and iron-deficiency anemia. Severely advanced cases can progress to cause tracheobronchial fistulas. Rarely, recurrent laryngeal nerve involvement can cause hoarseness. Endoscopic biopsy is required to confirm the diagnosis.

At the time of presentation, 22% of esophageal cancers are localized to the esophagus. Regional spread is present 30% of the time, and the remaining present as advanced disease.

Staging to evaluate regional and advanced spread is done via endoscopic ultrasound (EUS, which can diagnose local lymph nodes and liver metastases), bronchoscopy, and whole-body positron emission tomography (PET), and occasionally diagnostic laparoscopy. Laparoscopy is reserved for patients who have responded to chemotherapy and are surgical candidates but the extent of disease is unknown, or in whom extent of peritoneal disease is unclear from imaging. Tumor extending into the stomach for more than 5 cm is considered unresectable.

Treatment

Disease that is limited to the mucosa or submucosa is of a diameter of <2 cm, and does not involve the entire circumference of the esophagus can be treated with surgery or endoscopic therapy. For cancers that have invaded into the esophageal wall or are node-positive, treatment involves chemotherapy and surgery.

Endoscopic Ultrasound

Endoscopy with the use of ultrasound is becoming standard of care for diagnosis, biopsy, and occasionally treatment of small, localized esophageal tumors. Deep sedation may be appropriate for a small subset of patients who are asymptomatic at the time of presentation; general anesthesia with a protected airway is the method of choice due to aspiration risk.

Surgical Treatment and Intraoperative Considerations

Surgical Candidacy

Patients with stage T4b disease that is invasive to the aorta, trachea, or spine are considered unresectable, as are those who present with tracheoesophageal fistula. These patients can be candidates for radiation and chemotherapy, and reassessed for candidacy after demonstrating the appropriate response.

For early esophageal cancer, surgery is the mainstay of treatment, with or without neoadjuvant chemotherapy and radiation. Chemotherapy and/or radiation are considered before surgery for patients with full thickness involvement of the esophagus, or with local invasion to structures that can be easily resected. These patients undergo posttreatment radiologic staging to reassess resectability and undergo surgery 4–6 weeks after. Severe cardiac or pulmonary comorbid disease and advanced age are relative contraindications to surgery. Chronic obstructive pulmonary disease portends a higher risk of postoperative pulmonary complications, but several prehabilitation guidelines have been proposed to reduce this risk. Preoperative nutrition optimization is critical, as malnutrition is immunosuppressive and negatively impacts survival.

Relevant Anatomy

The esophagus consists of four layers: the mucosa, submucosa, muscularis propria, and adventitia. The arterial supply consists of the thyroid artery, the left gastric artery, the inferior phrenic artery, and the aorta. Lymphatic drainage is to the cervical, tracheobronchial, gastric, celiac, and mediastinal nodes.

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