Surgery for EC comprises of the removal of the primary lesion, LND and the restoration of the digestive tract. Such surgery is considered as one of the most extensive and traumatic of oncological surgical procedures, which not only involves a long operation time, but also a significant risk of morbidity .
In China, the optimal surgical procedure for EC remains an issue of debate, and the key controversial aspect is the extent of LND, in which there is presently no consensus. Published reports on this topic remain contradictory, and the choice of surgical approach is primarily driven by personal opinions and institutional preferences . In general, there are two schools of thought that concern lymphadenectomy. According to the first school of thought, EC is often accompanied by extensive metastases to cervical, thoracic and abdominal lymph nodes, justifying the three-field lymphadenectomy. This enables for a more accurate pathological staging, and achieves better local control of the disease and long-term survival. This procedure was pioneered in Japan. However, at present, after approximately 30 years of its wide application, there is increasing evidence that extensive lymphadenectomy is associated with improved survival . In the present cohort, 23.2% of patients underwent three-field LND in 2015.
In contrast, the other school of thought claims that extensive nodal dissection results in stage migration without improving the overall prognosis, and that associated complications can adversely affect postoperative recovery and long-term quality of life. This school attaches greater importance to safety and adjuvant therapy, when compared to lymphadenectomy, in the consideration that EC is at an advanced stage in most patients at the time of diagnosis, and that lymph node metastasis indicates the presence of systemic disease . In the present cohort, two-field LND was performed in 64.8% of all cases, and an even more limited dissection was performed in 13.4% of cases.
The extent of LND is determined by the operative approach. The average number of lymph nodes harvested was 21.6, 17.3 and 7.2, respectively, for three-field, two-field, and lower mediastinal and upper abdominal LND. Left thoracotomy was once widely performed in China, because it is quicker and simpler than the right-sided two- or three-stage approach. The main advantages of left thoracotomy are that it permits for the exploration of the tumor, the dissection of the lesion, and the mobilization of the stomach through a single incision. This approach is contraindicated when the tumor is located at or cephalad to the aortic arch. In the present cohort, left thoracotomy was frequently performed, and employed in approximately 23% of open procedures.
A combined right thoracic and abdominal approach, which allows standard two-field LND, is presently the main favored procedure in EC surgery . This procedure usually commences with an abdominal approach, which enables for the assessment of lymph node involvement, and the performance of gastrolysis, LND, jejunostomy, and sometimes, pyloroplasty. After the abdominal phase, right thoracotomy is performed, and intrathoracic lymphadenectomy and esophageal dissection is achieved. In the present study, the right thoracotomy approach was used in 45% of patients who underwent open surgery.
The McKeown procedure also allows for a standard two-field LND and a small component of the required neck LND . An additional neck incision can enable for the transfer of the anastomosis from an intrathoracic to a cervical location. Anastomotic leakage is easier to manage in the cervical region. Approximately 21% of open procedures in the present cohort used the McKeown style, while three-field LND was chosen for 21% of open procedures. In addition, 2% of patients underwent esophagectomy via the transhiatal approach.
In the past decade, minimally invasive approaches have gained rapid acceptance, and have become an alternative means of performing EC surgery in China. By minimizing the size of incisions and reducing external surgical stress, MIE has become associated with significant perioperative advantages, including lower overall incidences of in-hospital pulmonary infections and shorter duration of stay in the intensive care unit . MIE procedures limit the extent of possible traumatic stress, and thereby allow thoracic surgeons to achieve a good balance between oncological targets and safety . In the present cohort, the ratio of MIE to open procedures was 30:70%. It was considered that when the percentage of early-stage lesions increases in the future, this ratio would also increase.
After the optimal surgical procedure and extent of LND for EC, the second major issue concerning esophagectomy is the minimization of complications . Several techniques for reducing morbidity have been implemented. Anastomotic leakage has become a major concern, and the overall incidence in the present study was 5.6%. The anastomosis between the conduit and remaining esophagus can be located in the neck or chest. Several randomized trials have shown that both sites are equally safe, and have comparable morbidity [18,19,20]. A meta-analysis has shown no difference between these sites in the incidence of anastomotic leakage or stenosis . In the present cohort, cervical anastomosis was preferred to intrathoracic anastomosis (66.9% vs. 32.1%), which was probably because leakage in the neck results in less morbidity, and is easier to manage.
Early enteral nutrition aims to accelerate the recovery from esophagectomy. Naso-jejunal feeding tubes are the most commonly used, because these are time-saving and less invasive, when compared to the other routes. These were employed in 68.8% of patients in the present study. Jejunostomy, which is also a good choice for prolonged enteral nutrition, was performed in 26.8% of patients in the present cohort.
The stomach is the most common conduit for restoration of the digestive tract during esophagectomy. In the present study, gastric tubes were the first choice for reconstruction, and this was used in 68.3% of all procedures, while the whole stomach was used in approximately one-third of patients. The advantages of the whole-stomach technique are that it is economical and time-saving. However, it has an obvious disadvantage of having a higher proportion of atelectasis.
There was a prominent discrepancy between the present study and published literature concerning the routine ligation of the thoracic duct during esophagectomy. Although the ligation of the thoracic duct has been shown to reduce the incidence of postoperative chyle leakage , this procedure was not performed in approximately half of patients in the present study, leading to a 1.2% incidence of chylothorax.
Pyloroplasty is rarely performed, because it is time-consuming. Even though the incidence of delayed gastric emptying is nearly 1%, most surgeons consider pyloroplasty to be unnecessary, and that gastric emptying improves after the administration of adequate enteral nutrition.
At present, a multidisciplinary treatment that comprises of surgery, chemotherapy and radiotherapy has been widely used, with a demonstrated improvement in prognosis. Two pivot studies revealed a significant overall survival benefit in neoadjuvant treatment [23, 24]. These concepts are slowly being accepted by Chinese surgeons. In the present survey, merely 18.5% of patients received neoadjuvant therapy, while 21% of patients received adjuvant therapy. Considering that 82.1% of patients were at stage II/III, more clinical trials are needed to help Chinese surgeons devise a more precise treatment strategy.