Step 1
Surgical Anatomy
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The thoracic esophagus courses through the posterior aspect of the middle mediastinum. In most patients the esophagus lies in the midline; however, slight deviation to the right or left is not uncommon. Although the entire thoracic esophagus can be mobilized from either hemithorax, the ability to evaluate tissue planes at greatest risk for invasion dictates the approach. Tumors in the upper two thirds of the chest are most often approached from the right side of the chest (assess airway, azygos, pericardium), and tumors of the distal third are approached by several centers from the left side of the chest (assess aorta, pericardium, crus).
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The blood supply to the uppermost portion of the thoracic esophagus arises from the inferior thyroid arteries. The remainder of the thoracic esophagus is perfused by branches of the bronchial arteries and esophageal perforators directly from the aorta. Because of an extensive network of collaterals between the cervical, thoracic, and abdominal esophagus, the thoracic esophagus can be fully mobilized and left in situ if the operation is unable to be completed.
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An en bloc esophagectomy refers to the resection of all tissues from the hiatus to the arch of the azygos vein contained within the following borders: the left and right parietal pleura, the adventitia of the aorta, the vertebral bodies, the posterior pericardium, and the membranous airway at the carina. Included within this resection are the esophagus, the vagus nerves, periesophageal lymph nodes (levels 7 and 8), azygos vein (varies by surgeon), thoracic duct, bilateral parietal pleura, the base of bilateral inferior pulmonary ligament level 9 lymph nodes (bilaterally), and the posterior pericardium ( Fig. 25-1 ).
Figure 25-1
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A transthoracic lymph node dissection typically involves the periesophageal lymph nodes (level 8), bilateral inferior pulmonary ligament lymph nodes (level 9), subcarinal lymph nodes (level 7), and the right paratracheal lymph nodes (level 4) or the aortopulmonary (AP) window lymph nodes (level 5), depending on the approach. Typically, more than 15 lymph nodes can be expected with this type of resection.
Step 2
Preoperative Considerations
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Nutritional status should be evaluated by history (weight loss >20%) and chemistry (prealbumin <15). Nutritional supplements are typically administered orally, although percutaneous endoscopic gastrostomy tubes do not appear to affect subsequent reconstruction. It should be noted that most patients receiving neoadjuvant therapy will experience sufficient improvement in dysphagia to maintain their weight. ,
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The surgeon should perform an upper endoscopy (in the operating room or in the clinic) to plan the extent of resection. In addition to complete removal of the tumor, all Barrett mucosa should be removed. Both the gastric margin and esophageal margin should be grossly 5 cm from the tumor.
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A bowel preparation is generally reserved for patients in whom the stomach is likely to be an inadequate conduit. A computed tomography angiogram can be helpful if there is a question of compromise of the right gastroepiploic arcade from previous gastric surgery.
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Surgical approach is dictated by the following:
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Location of tumor: Tumors in the upper and middle portions of the chest should be addressed from the right chest, in large part to be able to assess invasion into surrounding airway. Tumors of the lower thoracic esophagus could be approached through either side of the chest. The left-sided chest is particularly helpful if the tumor is growing into the left hemidiaphragm.
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The ability to tolerate single-lung ventilation: If a patient has an anatomic reason that limits single-lung ventilation to a particular side, this should be evaluated preoperatively and approach tailored accordingly (operate on the side of worse function).
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Surgeon’s preference and experience: The oncologic differences between approaches appear to be subtle; safety should dominate this decision.
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Step 3
Operative Steps
Tri-Incision Esophagectomy (Modified McKeown)
1
Thoracic Portion
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A right-sided posterolateral thoracotomy is performed in the sixth intercostal space. The lung is palpated to exclude occult pulmonary metastases. The early dissection should focus on regions at greatest risk for extramural invasion (T4).
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Incise the inferior pulmonary ligament up to the inferior pulmonary vein. Remove right level 9 lymph nodes. Continue the pleural incision along the posterior hilum, past the right mainstem bronchus up to the arch of the azygos vein. Caution should be used when cauterizing near the membranous airway. The arch of the azygos vein may or may not be divided (surgeon preference).
Anterior Dissection
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Begin by dissecting between the pericardium and the esophagus at a point just inferior to the inferior pulmonary vein (if a bulky tumor is present at this level, the posterior pericardium is incorporated into the en bloc specimen).
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Continue this dissection superiorly and laterally until the bulk of the posterior pericardium is free and the left pleura is reached (to avoid the left -sided inferior pulmonary ligament, wait to incise the left pleura until the posterior esophageal dissection).
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Elevating the subcarinal lymph node packet will expose the left mainstem at the carina, preventing injury to the left-sided airway as the esophagus is mobilized from below (often this will feel firm from the double-lumen endotracheal tube) ( Fig. 25-2 ).
Figure 25-2
Posterior Dissection
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Incise the pleura along the posterior aspect of the esophagus, elevating the fatty streak off of the azygos vein towards the esophagus. Dissecting in the filmy plane just off the azygos vein will incorporate the thoracic duct in the en bloc specimen (as opposed to crease just posterior to the esophagus, which is a filmy plane that leaves the thoracic duct intact) ( Fig. 25-3 ).
Figure 25-3
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Continue up the arch of the azygos superiorly and the hiatus inferiorly. The leftward extension of this dissection will reveal the anterior-lateral surface of the aorta. Careful dissection will expose esophageal perforators that can be ligated and divided.
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As the lateral dissection is carried further, the left pleura is reached and incised. The left lung will need to be adherent to the superior aspect of the incised pleura (the left inferior pulmonary ligament).
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The ligament is divided, allowing the left pleura to remain fixed to the en bloc specimen. This incision continues up the left inferior pulmonary vein.
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A left level 9 lymph dissection is performed. Passing a Penrose drain around the esophagus for retraction can facilitate exposure of the leftward aspect of the specimen.
Superior Dissection
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For tumors that arise in the mid to distal thoracic esophagus, all dissection cephalad to the arch of the azygos should be directly on the esophageal wall (to avoid injury to recurrent nerves).
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For tumors of the upper thoracic esophagus, the dissection should include as much periesophageal tissue as possible.
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Care should be taken as the dissection approaches the thoracic inlet because the right recurrent nerve can be injured at this level.
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The thoracic duct crosses over from right to left near the arch of the azygos vein. If the tumor mandates a wide dissection at this level, ligate the periesophageal tissue with ties to avoid a lymph leak.
Inferior Dissection
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At the level of the hiatus the pleura is opened over the right crus.
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The phrenoesophageal ligament and peritoneum are incised to allow entry into the abdomen. This incision is carried circumferentially around the esophagus.
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The thoracic duct typically courses between the aorta and azygos vein. In this region the soft tissue must be suture ligated prior to division.
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If the tumor is locally invasive at this level, a rim of crus should be removed in continuity with the tumor. Care should be taken to avoid the phrenic nerve.
Closure
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The ribs are brought together with interrupted pericostal Vicryl sutures (No. 2 Vicryls).
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The soft tissue is reapproximated in multiple layers with absorbable suture.
Abdominal Dissection
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Through an upper midline laparotomy, the falciform ligament and the left triangular ligament are divided. This will allow the left lateral segments of the liver to be retracted into the right upper quadrant.
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Aggressive retraction of the xyphoid and costal arch superiorly and anteriorly will dramatically enhance the exposure of the epigastrium and hiatus.
Gastric Mobilization
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The pars flaccida, or clear membrane overlying the caudate lobe of the liver, is incised to expose the right crus.
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The periesophageal soft tissue is dissected off of the right crus, exposing the junction of the right and left crura posteriorly.
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The dissection continues anteriorly and the periesophageal tissue is dissected off of the left crus. With a little bit of blunt dissection, the esophagus should be easily mobilized circumferentially, allowing a Penrose drain to be passed around the esophagus.
Short Gastric
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The lesser sac can be entered at any point along the greater curvature; however, one must be aware of the transition from the right gastroepiploic to the short gastrics because the former must be preserved. It is often preferable to identify the right gastroepiploic arcade near the midportion of the greater curvature and start dividing the omentum 1 to 2 cm peripheral to the gastroepiploic arcade. This is continued up toward the fundus.
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Once the transition to the short gastrics is identified, the short gastrics are divided a centimeter off the stomach. Great care must be taken in the region of the splenic hilum because there are often adhesions to the splenic capsule. The dissection may be facilitated by dividing the adhesions in the lesser sac that tether the posterior wall of the stomach.
Left Gastric Artery
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As the stomach is elevated toward the hiatus, the left gastric artery can be identified in a band of fat between the retroperitoneum and lesser curvature (the vessels can also be approached from the right). The base of this pedicle should be thinned out to allow the left gastric lymph nodes to be contained within the specimen.
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The veins running alongside the artery are relatively fragile. Care should be taken to avoid the splenic artery because it courses laterally at the same level as the origin of the left gastric artery.
Gastric Conduit
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The shape of the conduit is dictated by the location of the tumor as well as by surgeon preference for whole stomach or a narrow gastric tube. In either case, the gastroesophageal junction must be resected, requiring division of at least the two highest vascular rami of the lesser omentum. The narrower the tube, the more rami that must be ligated toward the pylorus.
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A staple line is started on the lesser curve of the stomach and continued toward the fundus in a line that parallels the greater curvature ( Fig. 25-4 ).
