Esophageal Cancer
The Unique Anatomy Of Esophagus
Esophagus or food pipe is the structure that connects pahrynx (back of the mouth) to stomach, via thorax (chest). Thus it passes through 3 anatomical areas namely, neck, thorax and abdomen. This anatomy is the reason for complexity of the surgical procedure for this cancer.
Esophagus is approximately 25 cm long muscular tube. It can be arbitrarily divided into 4 parts; cervical, upper thoracic, mid thoracic and lower esophagus. Endoscopically this would correspond to 15 cm from incisor to 20 cm, 20 to 25 cm, 25 to 30 cm and 30 to gastroesophageal junction respectively.Tumors involving gastroesophageal junction and/or with their epicenter within 5 cm of the junction are treated akin to lower esophageal cancers.
Due to this unique anatomy, lymphatics from esophagus can drain into cervical, mediastinal or upper abdominal nodes.
Pathological Types Of Cancer
The cancers arising from the epithelium of esophagus can be of two types; squamous cell carcinoma (SCC) or adeno-carcinoma (AC). Usually SCC occurs in the cervical, upper or mid thoracic esophagus. It is rare in lower esophagus. Whereas, AC is mainly seen in the lower esophagus and gastroesophageal junction, and often secondary to long term gastro-esophageal reflux disease. Though there is no major difference between the outcomes of the two histological types, the adjacent therapy varies.
Concepts Of Treatement For Esophageal Cancer
Surgery has been the treatment of choice for localized and respectable cancers of esophagus. However, multi-modality therapy has come into existence as surgery alone has failed to alter the course of the disease. The results of multimodality approach have not been consistent. Controversy exists in every aspect of treatment of esophageal cancer. A subjective approach is suitable for this disease.
Traditional Surgical Approaches To Esophageal Cancer
The idea of surgical resection of esophageal cancer is to resect the diseased portion with adequate margins. However, due to the unique location of esophagus (vide supra) esophagectomy is a complex surgery.
The Approaches can be Classified into Two Types:
Trans-Hiatal Esophagectomy (THE): This involves a laparotomy and cervical approach. The thoracic esophagus is dissected bluntly buy surgeons hand. This surgery was popularized by Orringer et al. who have published a series of more than 1000 in 1999. Though THE reduces the post-operative thoracic complication rates, the approach makes it difficult to perform a complete nodal dissection or en-bloc dissection. For cancers of lower esophagus and gastro-esophageal junction, it is possible to perform wide dissection by THE.
Trans-Thoracic Esophagectomy (TTE):There at least four approaches that can be discussed under the heading of TTE.
- Ivor Lewis approach which involves right thoracotomy and laparotomy. Peritumoral and two field lymph-node dissections can be manged in this approach. En-bloc dissection can be performed for mid or lower esophagus. The drawback of this procedure is the esophago-gastric anastomosis within the thoracic cavity, which, if leaks can be fatal.
- McKeown approach involves three incisions; Right thoracotomy, laparotomy and cervical. Here the anastomosis is in the neck, where a leak can be safely managed. It is possible to perform peritumoral, two field or three field lymph-node dissections. En-bloc dissection can be performed for mid or lower esophagus. This is the approach that can assist in maximum radicality.
- McKeown approach involves three incisions; Right thoracotomy, laparotomy and cervical. Here the anastomosis is in the neck, where a leak can be safely managed. It is possible to perform peritumoral, two field or three field lymph-node dissections. En-bloc dissection can be performed for mid or lower esophagus. This is the approach that can assist in maximum radicality.
- Left thoraco-abdominal approach can used for lower esophageal tumors. Peritumoral nodal dissection can be performed. Anastomosis is performed in the thorax.
Controversy exists as to which approach is superior. The clinical trials have not been able clear these controversies. A Dutch trial comparing THE with TTE did not show significant difference in survival between the groups. However, there is a trend towards better survival for those who underwent TTE.
Radicality Of Surgery
The survival statistics following traditional esophagectomy, where the nodal tissues are not removed, have been dismal. In order to improve the survival some centers have tried more radical approaches. Two concepts guide these extended approaches.
En-bloc resection: This involves resection of the tumor bearing esophagus along with surrounding structures as envelope. Thus pleura laterally, pericardium anteriorly, azygos vein and thoracic duct posteriorly are excised along with the fibrofatty tissue around esophagus. Diaphragmatic hiatus is resected for tumor at gastro-esophageal junction.
Systematic lymph node dissection- 2 field or 3 field: Two field lymphadenectomy involves dissection of nodes from tracheal bifurcation to esophageal hiatus. In the upper abdomen nodes along celiac trunk and its branches (except splenic artery), and along portal vein are dissected. A three field dissection, in addition to two field, should include nodes along splenic artery, recurrent laryngeal nerves and lower cervical groups.
Though extended approaches have shown to be beneficial, most of the data on these surgeries are retrospective and single institutional
Minimal Access Cancer Surgery(Macs) For Esophageal Cancer
Why should we prefer macs for esophagus ?
- Less pain and wound related problems: The unique anatomical location of esophagus (vide supra) makes open esophagectomy a very difficult and painful procedure for both patient and surgeon alike. The surgery involves 1,2 or 3 wounds depending on the type (vide supra). For best oncological results 2 or 3 field lymphadenectomy is performed and most surgeons prefer right thoracotomy to do this. Thoracotomy not only causes lung related complications and severe pain immediately after surgery, but also leads to long term pain in the chest and anterior abdomen. Esophagectomy when performed by MACS techniques avoids most of these complications which are mainly related to access wound.
- Better vision: One of the very difficult aspects of open thoracic surgery is the visibility and access for surgical procedure, due to rigidity of the thoracic cage. There is always a limit to which ribs can be spread fracturing them and adding to long term pain. MACS not only is done trough tiny incisions, but, also give far better visibility to the surgeon. This makes surgeries far simpler.
The Evidence
Recommendation
References
Hulscher JB et al. Extended transthoracic resection compared with limited transhiatal resection for adenocarcinoma of the esophagus. N Engl J Med. 2002 Nov 21;347(21):1662-9.
D.J.Mathisen,H.C.Grillo,E.W.Wilkins,A.C.Moncure, and A. D. Hilgenberg, “Transthoracic esophagectomy: a safe approach to carcinoma of the esophagus,” Annals of Thoracic Surgery, vol. 45, no. 2, pp. 137–143, 1988.
O.A.Jarral,S.Purkayastha,T.Athanasiou,andE.Zacharakis, “Should thoracoscopic three-stage esophagectomy be performed in the prone or left lateral decubitus position?” Interactive Cardiovascular and Thoracic Surgery, vol. 13, no. 1, pp. 60–65, 2011.
N.T.Nguyen,X.M.Nguyen,K.M.Reavis,C.Elliott,H. Masoomi, and M. J. Stamos, “Minimally invasive esophagectomy with and without gastric ischemic conditioning,” Surgical Endoscopy, vol. 26, no. 6, pp. 1637–1641, 2012.
G.M.Campos,D.Jablons,L.M.Brown,R.M.Ramirez,C. Rabl, and P. Theodore, “A safe and reproducible anastomotic technique for minimally invasive Ivor Lewis oesophagectomy: the circular-stapled anastomosis with the trans-oral anvil,”European Journal of Cardiothoracic Surgery,vol.37,no.6,pp.1421–1426, 2010.