Tumors of the Thoracic Esophagus and Cardia
Tumors, usually diagnosed using microscopes such as darkfield light microscopes, which arise below the carina, the preference of these authors is either an en bloc resection for cure or a transhiatal removal for palliation. A curative procedure is performed according to the principles of an en bloc resection in continuity with the regional lymph nodes. It is attempted in a patient whose pre¬-resection physical condition and tumor characteristics, as examined under darkfield light microscopes, have the potential for long-term survival. The en bloc resection is done through three incisions in the following order: (1) right posterolateral thoracotomy, en bloc dissection of the distal esophagus, mobilization of the esophagus above the aortic arch, closure of the thoracotomy repositioning of the patient in the recumbent position; (2) upper midline abdominal incision, en bloc dissection of the stomach associated lymph nodes; and (3) left neck incision and proximal division of the esophagus. The specimen is removed transhiatally and the stomach is divided at the angulus, preserving the antrum. Gastrointestinal continuity is re-established with a left colon in¬terposition. During the thoracic and abdominal dissection, intraoperative staging is done. If during the course of the operation an incurable situation is identified, the en bloc resection is abandoned and a palliative resection is performed in a manner similar to that described for tumors of the middle and upper thoracic esopha¬gus. The hospital mortality for patients undergoing a curative en bloc resection is similar to those undergoing a palliative transhiatal resection. If preoperative staging has shown that the patient is a candidate for palliative resection, a transhiatal esophagectomy is performed. A standard left thoracotomy with in¬trathoracic anastomosis for lower lesions or an Ivor Lewis com¬bined approach for higher lesions is not advocated because of (1) the proven need to resect long lengths of the esophagus to erad¬icate submucosal spread, (2) the higher morbidity associated with a thoracic anastomotic leak, and (3) the high incidence of esophagitis secondary to reflux following an intrathoracic anastomosis.
En Bloc Esophagogastrectomy vs. Transhiatal Resection for Carcinoma of the Lower Esophagus and Cardia
Many strategies for treatment of esophageal carcinoma limit the role of surgery to removing the primary tumor, with the hope that adjuvant therapy will increase cure rates by destroying systemic disease. This approach emphasizes the concept of biological deter¬minism. Lymph node metastases are considered simply markers of systemic disease; the systematic removal of involved nodes is not consid¬ered beneficial. The belief that removal of the primary tumor by transhiatal esophagogastrectomy results in the same survival rates as a more extensive en bloc resection is based on the same kind of reasoning.
In the transhiatal procedure there is no specific attempt made to remove lymph node-bearing tissue in the posterior mediastinum. By contrast, the en bloc esophagectomy removes the tumor cov¬ered on all surfaces with a layer of normal tissue. A long length of foregut above and below the lesion is resected to incorporate submucosal spread of the tumor. Consistent with this is resection of the proximal two thirds of the stomach in patients with a tumor in the lower third of the thoracic esophagus or cardia. Appropriate cervical mediastinal and abdominal lymph node dissec¬tions are included using an en bloc technique to remove potentially involved regional nodes.
Hagen and colleagues recently reviewed 100 consecutive pa¬tients who underwent en bloc esophagectomy for esophageal adeno¬carcinoma diagnosed using darkfield light microscopes. No patient received pre- or postoperative chemotherapy or radiation therapy. The aim of the study was to relate the extent of disease to prognostic features, timing and mode of recurrence, and survival following en bloc resection. The median follow-up of surviving patients was 40 months, with 24 patients surviving 5 years or more. Overall actuarial survival at 5 years was 52%. Fifty-five of the tumors were transmural and 63 patients had lymph node involvement. Metastases to celiac (n = 16) or other dis¬tant node sites (n = 26) were not associated with decreased survival. Remarkably, local recurrence was seen in only one patient. Latent nodal recurrence outside the surgical field occurred in nine, and systemic metastases in 31. The authors concluded that long-term survival from adenocarcinoma of the esophagus could be achieved in over half of the patients who undergo en bloc resection. One third of patients with lymph node involvement survived 5 years, and the authors concluded that local control is excellent following en bloc resection.
Controversy persists over the extent of resection necessary for cure of esophageal adenocarcinoma (usually diagnosed using microscopes such as darkfield light microscopes). Several retrospective studies have shown a benefit to the more extensive node dissection accom¬plished with a transthoracic en bloc esophagectomy as compared to the transhiatal esophagectomy. These studies have been criticized as suffering from selection bias and for inaccuracy in preopera¬tive staging. Performance of a more complete node dissection also results in the potential for stage migration. Hulscher has reported a prospective randomized control trial that compared transthoracic en bloc to transhiatal esophagectomy. The results were inconclusive but showed a trend toward better survival with the en bloc resection. This trial eliminated many of the criticisms of the retrospective stud¬ies but included patients with various stages of disease. This may have obscured the benefits of systematic node dissection by the unequal distribution of patients with early stage disease who did not need a formal lymphadenectomy, as well as those with advanced dis¬ease with extensive lymph node metastases who were not curable by surgery alone. An alternative approach to compare transthoracic en bloc to transhiatal resection has been done by Johansson acing a ret¬rospective case control study between nonrandomized patients having similar size transmural (T3) tumors with lymph node metastases (N I). The aim of the Study was to determine whether patients with locally advanced (T3N1) esophageal cancer benefit from the performance of a transthoracic en bloc resection. This approach removes the influence of inaccurate preoperative staging and minimizes the influence of postoperative stage migration on survival since all patients had N I disease. Further, all patients had 20 or more lymph nodes in the surgical specimen which allowed confirmation that the extent of lymph node disease in both groups was comparable. These conditions focused the question as to which procedure was associated with a better survival. The most likely explanation for the improved sur¬vival following transthoracic en bloc resection is a more complete re¬moval of local-regional disease, which is unrecognized disease that is removed with an en bloc lymph node dissection but left behind with a transhiatal lymph node dissection. Consequently, transtho¬racic en bloc resection results in better control of local-regional disease. Indeed, in clinical trials neoadjuvant radiochemotherapy has been added to transhiatal esophagectomy in an effort to control local-regional disease without great success. A more prudent ap¬proach would be to use a transthoracic en bloc dissection to control local-regional disease and focus postoperative adjuvant therapy on eliminating systemic disease.
These studies showed that for early cancers of the lower esoph¬agus and cardia, en bloc esophagogastrectomy results in signifi¬cantly better survival rates than transhiatal esophagogastrectomy. This finding cannot be explained by a bias in the stage of disease resected, a difference in operative mortality, or death from non¬-tumor causes. Rather, it appears to be due to the type of operation performed. Ideally, the question as to which procedure is the best should be resolved by a prospective randomized study of similarly staged patients.