Left Thoracoabdominal Approach




Introduction



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A thoracoabdominal approach to resection of the esophagus is most useful with tumors of the distal esophagus that lie inferior to the aortic arch as well as lesions of the gastric cardia. Eggers first reported the use of a left thoracoabdominal incision for a partial resection of the esophagus in 1931.1 Eventual resection of the distal esophagus and replacement with mobilized stomach was described by Adams and Phemister in 1938.2 Finally, Sweet3 described the technique of anastomosis on the basis of the principles of meticulous technique and attention to detail. The thoracoabdominal incision provides excellent access to the abdomen. With extension of the incision through the costal arch, left rectus muscle, and diaphragm, the esophagus can be mobilized and replaced with stomach, colon, or jejunum depending on the situation. In addition, with an upward paravertebral extension of the incision and Sweet’s double-rib resection, one can reach almost any lesion of the intrathoracic esophagus.3




Preoperative Assessment



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Because of the magnitude of a thoracoabdominal esophagectomy or any esophagectomy, it is important to engage in a rigorous selection and staging work-up before proceeding with surgical intervention. Although patients with widely disseminated disease and extreme comorbid illnesses are easily eliminated from surgical consideration, most patients undergo a systematic evaluation of resectability and a review of risk factors.



The initial evaluation of patients with esophageal carcinoma should include a contrast esophagogram and upper gastrointestinal endoscopy. Esophagoscopy with biopsy of the lesion is essential to obtain a tissue diagnosis, to confirm that there is not a second synchronous esophageal carcinoma, and to obtain a more accurate assessment of the extent of the tumor both grossly and microscopically by mucosal biopsy. Endoscopy also Barrett’s esophagus and evaluation of potential gastric involvement.



Further evaluation by CT imaging of the thorax and abdomen provides information regarding invasion of adjacent structures (e.g., pericardium and diaphragm), tracheobronchial invasion, and mediastinal lymph node involvement. However, recent reports have noted the accuracy of CT imaging for the presence of locoregional disease to be as low as 50%.4,5 CT imaging of the abdomen with contrast material also assists in the detection of hepatic metastasis.



Endoscopic ultrasound (EUS) is used commonly in the local staging of esophageal cancer. It provides valuable data regarding the depth of tumor invasion, potential nodal involvement, and the opportunity for fine-needle aspiration of adjacent lymph nodes. Accuracy in predicting T status with EUS in esophageal cancer is greater than 80%, and accuracy in predicting N status ranges around 70%.6 EUS is clearly superior to CT in T staging, and appears more accurate in predicting T4 disease.7



PET imaging is becoming a more valuable tool in the evaluation of distant metastatic disease. PET scans have almost no role in the determination of T status, but in regard to metastatic disease, the results are encouraging, with reports of greater than 90% accuracy.8 (PET imaging may have a further application in monitoring for disease recurrence.)



An evaluation of preoperative risk factors includes an assessment of pulmonary and cardiovascular function. Pulmonary function testing should be obtained if there are any questions as to the patient’s respiratory status. Smoking should be stopped well in advance of surgery. A cardiovascular assessment also should be performed with a history and physical examination, as well as an ECG and, if deemed necessary, a stress test or cardiac catheterization.




Technique



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It is suggested that all esophageal procedures, including thoracoabdominal esophagectomy, begin with endoscopy in the operating room. Repeat endoscopy provides confirmation of the location of the tumor and evaluation of the esophagus for a second lesion or extension into the stomach. With tumors of the middle and upper thirds of the esophagus, bronchoscopy also should be performed. A double-lumen endotracheal tube is placed, permitting deflation of the left lung during the thoracic dissection, and broad-spectrum antibiotics are given before surgical incision and may need redosing during the procedure. We encourage the liberal use of an epidural catheter in the management of postoperative pain, given the extend of the incision.



The patient is positioned in the right lateral decubitus position, which permits access to both the left side of the chest and the upper abdomen. The initial step is an exploration of the abdomen through the medial portion of the incision. A valuable landmark in planning the abdominal portion of the incision is to aim the medial aspect at a point halfway between the xiphoid and umbilicus. The abdominal portion of the incision permits inspection of the liver, palpation of the celiac nodes, and further evaluation of the stomach. With no metastatic disease identified, the incision is carried into the chest over the seventh or eighth rib (Fig. 21-1). The higher the interspace, the easier it is to perform the anastomosis. As the diaphragm is divided, it should be clearly marked with stitches to allow reapproximation at the conclusion of the case.




Figure 21-1


The incision is carried into the chest over the seventh rib. The higher the interspace, the easier it is to perform the anastomosis. As the diaphragm is divided, it should be clearly marked with stitches to allow reapproximation at the close of the procedure.





Thoracic Dissection


Thoracic exploration begins with an inspection of the left lung, diaphragm, pericardium, and pleural space. Opening of the mediastinal pleura permits further inspection of the extent of the tumor, evaluation of possible invasion of the aorta or lung, and determination of metastases to the paraesophageal and paraaortic lymph nodes.



Dissection begins in the chest, freeing the esophagus and harvesting all adjacent lymph nodes. The descending aorta is completely bared by division of the aortoesophageal branches. Aortic involvement precludes resection. The esophagus is encircled after the dissection is carried medially along the posterior aspect of the mediastinum up to the level of the left main stem bronchus, away from the proximal tumor margin. Gentle traction on the esophagus facilitates dissection of the paraesophageal nodes and fat. The thoracic duct is rarely seen with the left thoracoabdominal approach and is not routinely ligated.



It may be necessary to mobilize the esophagus superior to the level of the aortic arch. Division of aortic intercostal vessels is necessary to gain adequate mobilization of the arch. With mobilization of the arch, the left recurrent nerve must be carefully preserved. In addition, it is at this point that the thoracic duct is most vulnerable to injury, and the left main stem bronchus also must be examined for injury to the membranous wall.



Abdominal Dissection


Mobilization of the stomach begins with the division of the greater omentum. This is performed outside the gastroepiploic arcade formed by the left gastroepiploic artery arising from the splenic artery and the right gastroepiploic artery arising from the gastroduodenal artery at the pylorus. Use of the stomach to replace the esophagus hinges on the patency of the right gastroepiploic artery and to a lesser degree, the right gastric artery. The transverse colon is placed on stretch, and the lesser sac is entered at the thinnest portion of the omentum. The dissection is carried toward the pylorus, dividing the small omental branches of the epiploic artery. Cautery coagulation is used sparingly for fear of damaging the gastroepiploic arcade. Dissection then is carried toward the spleen, where the left gastroepiploic artery is ligated at the upper end of the arcade as it arises from the splenic artery. Management of the short gastric arteries deserves special attention, and it must be ensured that the ties on the stomach are secure because they can slip with distention of the stomach within the thorax. Alternative methods for controlling the short gastric vessels include use of the Harmonic Scalpel (Ethicon-Endosurgery, Inc.) or the LDS (US Surgical, Norwalk, CT) stapling device.



At the level of the esophagogastric junction, the reflection of the peritoneum is divided, and the esophagus is encircled. Passage of a Penrose drain allows for upward traction on the abdominal esophagus and dissection of the lesser curve. The thin avascular gastrohepatic ligament is divided, and placement of a second thin Penrose drain around the stomach at the level of the incisura can further assist with dissection of the lesser curve. The gastrohepatic ligament should be inspected for an accessory branch of the left hepatic artery. If one is identified, it should be occluded temporarily with a bulldog clamp and the liver assessed for viability. If concern exists about the vascular supply of the liver, the accessory branch must be preserved. This can be done by skeletonizing the accessory branch to its origin from the left gastric artery and preserving these vessels.

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Dec 30, 2018 | Posted by in VASCULAR SURGERY | Comments Off on Left Thoracoabdominal Approach
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