The incidence of cardia cancer is a common malignant tumor, and its clinical incidence has been on the rise in recent years, from 1976 to 1987, the incidence of cardia cancer in the United States increased from 3.6% to 5.6%. Sihvo et al. reported that cardia cancer accounted for 6.4%-20.0% of gastric tumors. Most patients with pancreatic cancer are already in the middle or late stage when they are diagnosed, and surgery is currently the preferred treatment option.
There are several choices of surgical incisions for cardia cancer, each with its own advantages and disadvantages. Clinically, the choice of incision for pancreatic cancer surgery depends to a certain extent on the surgeon’s habits and preferences. In different regions or different medical units in the same region, there are still controversies regarding the diagnosis and treatment of cardia cancer. General surgeons are accustomed to the transabdominal approach, while thoracic surgeons are accustomed to the transthoracic approach, and each side has its own opinion. The combined thoracoabdominal incision requires a high level of familiarity with the anatomy of the thoracoabdominal cavity and the ability to handle possible intraoperative and postoperative complications, which to some extent limits the application of this incision. Especially, there has not been a reasonable standard for when to choose a combined thoracoabdominal incision.
Biological behavior characteristics of cardia cancer Cardia cancer is a malignant tumor that occurs in the cardia gland within 2 cm above and below the esophagogastric junction (GE-Tuniction). Cardia cancer is different from both gastric and esophageal cancers. It is located in the junction of esophagus and stomach, so its biological behavior is also different from that of tumors occurring in stomach and esophagus.
The lymph node metastasis rate of pancreatic cancer is high, and there are two metastatic pathways: thoracic and abdominal, but the metastasis is mainly to the abdomen, especially to the abdominal arterial trunk, splenic artery and splenic hilum, and also to the lymph nodes adjacent to the abdominal aorta. The lymph node metastasis rates in groups 5 and 6 of cardia were 13% and 11%, respectively, and the lymph node metastasis rates in splenic hilar and splenic artery trunk were 16% and 11%, respectively. Meanwhile, the metastasis rate of paraoesophageal lymph nodes in cardia cancer was about 10%, and the metastatic area of lymph nodes involved the paraoesophageal and posterior mediastinum of the chest.
Cardia cancer tends to have low differentiation and high malignancy, and the proportion of low-differentiated adenocarcinoma and mucinous adenocarcinoma is much higher than that of lower gastric cancer, and it has a strong ability to invade the esophageal side, and the infiltration rate of esophageal side of cardia cancer is reported to be 42% in China. Once the lower esophageal segment is invaded, the infiltration length is often greater than 3 cm, and Deng Guangwu et al. reported that it reached 44.4%, which means that nearly one-fifth of pancreatic cancer patients have infiltration length of lower esophageal segment greater than 3 cm, which requires at least 8 cm of lower esophageal segment to be cut off to achieve radical treatment. Most patients with pancreatic cancer are already in the middle or late stage when they are diagnosed, and the tumor has already penetrated the plasma membrane, often with limited involvement of abdominal organs, such as the left liver, spleen, pancreas and other organs. In this case, partial or total resection of one of the abdominal organs is required to achieve relative or complete cure.
Advantages and disadvantages of cardia surgery through left thoracic incision and transabdominal incision Advantages of cardia surgery through left thoracic incision: ① Complete exposure of the mid-thoracic section and the esophagus below, which is conducive to the removal of sufficient length of esophagus without affecting the anastomosis reconstruction and avoiding the residue of the upper cut edge. In our data, none of the transthoracic incision groups had residual incision margins; ②The lymph nodes under the aorta, main pulmonary window, ascending aorta, esophagus, and posterior mediastinum can be thoroughly cleared; ③The thoracic cavity is clearly exposed, which is conducive to the protection of thoracic organs during surgery; ④The affected diaphragm at the foot of the diaphragm can be removed and repaired under direct vision. Disadvantages: ① Although the left thoracic incision can clear the lymph nodes of groups 1, 2, 3 and 7, it is still difficult to clear the lymph nodes of other stations of the abdominal cavity. (3) Due to the limitation of exposure, it is easy to damage the abdominal organs during operation. In our hospital data, there are two cases in which the spleen had to be removed due to damage during the left thoracic incision; (4) There are more cardiopulmonary complications, and the incidence of pleural effusion and pneumonia is significantly higher than that of the transabdominal group.
Advantages of transabdominal incision for pancreatic cancer surgery: ① the abdominal cavity is more clearly exposed through the transabdominal approach, sufficient stomach can be resected, residue of the lower incision margin can be avoided, and lymph nodes in the abdominal cavity can be thoroughly cleared; ② the combined organs can be resected more conveniently, and the radical rate of surgery is higher; ③ the cardiopulmonary impact is small, which is suitable for elderly patients and those with cardiopulmonary insufficiency. Although the application of mechanical anastomosis can make the anastomosis more convenient, the complication of anastomotic stenosis increases significantly. Moreover, transabdominal approach for resection anastomosis often results in retraction of the anastomosis back to the thoracic cavity due to the removal of more lower esophageal segments, which makes it impossible to confirm the anastomotic effect and further reinforce the suture, thus leaving safety risks; ④ the diaphragmatic foot can often only be separated bluntly, which easily causes tumor residual.
Advantages of combined thoracoabdominal incision for cardia surgery The combined thoracoabdominal incision has the advantages of both open chest and open abdomen, with open surgical field and good exposure. It can completely resect the long enough esophagus above the cancer focus and thoroughly clear the lower paraesophageal lymph nodes, so as to reduce the residual rate of cancer in the upper incision margin. This improves safety.
Traditionally, it is believed that the combined thoracoabdominal incision has many postoperative complications and poor thoracic stability, which affects the patient’s respiratory function and is not conducive to postoperative recovery. Lu Shijie et al. found that cardiopulmonary complications were three times more frequent in patients over 60 years of age than in those under 60 years of age after cardia cancer surgery. The most common complication in the combined thoracoabdominal incision group was pleural effusion, and we experienced that the chest X-ray and ultrasound were checked within 48 hours after surgery, and we removed the chest drain even if there was a small amount of effusion, and then performed puncture and aspiration if the effusion still existed. In contrast, the incidence of pneumonia is low and most of them can be cured with anti-inflammatory treatment. The complications are within the acceptable range. Of course, good aseptic operation, accurate placement and effective drainage of thoracoabdominal drains, timely postoperative sputum drainage and airway nebulized inhalation, and reasonable application of antibiotics all help to reduce pulmonary complications in combined thoracoabdominal incision for cardia surgery.
Indications for cardia surgery with combined thoracoabdominal incision Papachriston et al. concluded that surgical treatment of cardia cancer must meet the following criteria: (i) resection of the primary cancer and prevention or removal of esophageal obstruction; (ii) ensuring that no cancer remains in the incision margin; and (iii) removal of lymph nodes that may metastasize.
The biological behavior of cardia cancer determines that its surgery involves the thoracoabdominal cavity, while the clearance of lymph nodes and combined organ resection determines that most of the operations should be performed in the abdominal cavity; however, when the tumor infiltrates the lower esophagus beyond the esophagogastric junction, it is difficult to ensure the eradication of the tumor by transabdominal surgery alone. At this time, the combined thoracoabdominal incision is the best incision for radical surgery of cardia cancer.
We believe that patients with pancreatic cancer whose medical history complains of dysphagia or retrosternal pain often suggest infiltration of the lower esophagus, and if gastroscopy and/or GI confirms esophageal infiltration, a combined thoracoabdominal incision should be chosen. Intraoperative exploration reveals infiltration of the lower esophagus, then an additional thoracic incision is required. The combined thoracoabdominal incision significantly reduces residual esophageal margins; satisfies the clearance of thoracic lymph nodes; postoperative cardiopulmonary complications are within acceptable limits; and perioperative mortality is not increased as a result.
Of course, not all pancreatic cancer patients should choose combined thoracoabdominal incision. If the tumor is clearly confined to the cardia of the fundus and does not infiltrate the lower esophagus beyond the esophagogastric junction, transabdominal approach is still safe and effective. The purpose is to achieve less trauma, less interference with breathing and circulation, and faster postoperative recovery.
In conclusion, the surgical treatment of cardia cancer is controversial in many aspects. Reasonable incision selection is the key to ensure complete resection and improve long-term survival rate. We believe that a combined thoracoabdominal incision is the most reasonable choice for cardia cancer surgery if the patient’s cardiopulmonary function is fully evaluated before surgery and if the patient can tolerate surgery, as long as the tumor infiltrates the esophagus clearly before or during surgery.