Anesthesia for Esophageal Surgery
Common indications for esophageal
surgery include tumors, gastroesophageal reflux, and motility disor-ders
(achalasia). Surgical procedures include simple endoscopy, esophageal
dilatation, cervical esoph-agomyotomy, open or thoracoscopic distal
esoph-agomyotomy, insertion or removal of esophageal stents, and esophagectomy.
Squamous cell carcino-mas account for the majority of esophageal tumors;
adenocarcinomas are less common, whereas benign tumors (leiomyomas) are rare.
Most tumors occur in the distal esophagus. Operative treatment may be
palliative or curative. Although the prognosis is generally poor, surgical
therapy offers the only hope of a cure. After esophageal resection, the stomach
is pulled up into the thorax, or the esopha-gus is functionally replaced with
part of the colon (interposition).
Gastroesophageal reflux is treated
surgi-cally when the esophagitis is refractory to medi-cal management or
results in complications such as stricture, recurrent pulmonary aspiration, or
Barrett’s esophagus (columnar epithelium). A variety of antireflux operations
may be performed (Nissen, Belsey, Hill, or Collis–Nissen) via tho-racic or
abdominal approaches, often laparoscopi-cally. They all involve wrapping part
of the stomach around the esophagus. Achalasia and systemic sclerosis
(scleroderma) account for the majority of surgical procedures per-formed for
motility disorders. The former usually occurs as an isolated finding, whereas
the latter is part of a generalized collagen–vascular disorder. Cricopharyngeal
muscle dysfunction can be associ-ated with a variety of neurogenic or myogenic
dis-orders and often results in a Zenker’s diverticulum.
Regardless of the procedure, a common
anes-thetic concern in patients with esophagealdisease is the risk of pulmonary
aspiration. This may result from obstruction, altered motility, or abnormal
sphincter function. In fact, most patients typically complain of dysphagia,
heartburn, regurgi-tation, coughing, and/or wheezing when lying flat. Dyspnea on
exertion may also be prominent when chronic aspiration results in pulmonary
fibrosis. Patients with malignancies may present with ane-mia and weight loss.
Esophageal cancer patients usually have a history of cigarette smoking and
alcohol consumption, so patients should be evalu-ated for coexisting chronic
obstructive pulmonary disease, coronary artery disease, and liver dysfunc-tion.
Patients with systemic sclerosis (scleroderma) should be evaluated for
involvement of other organs, particularly the kidneys, heart, and lungs;
Raynaud’s phenomena is also common.
In patients with reflux, consideration
should be given to administering metoclopramide, an H2-receptor
blocker, or a proton-pump inhibitor preoperatively. In such patients, a
rapid-sequence induction should be used. A double-lumen tube is used for
procedures involving thoracoscopy or tho-racotomy. The anesthesiologist may be
asked to pass a large-diameter bougie into the esophagus as part of the
surgical procedure; great caution must be exer-cised to help avoid pharyngeal
or esophageal injury.
Transhiatal (blunt) and thoracic
esophagec-tomies deserve special consideration. These pro-cedures often involve
considerable blood loss. The former requires an upper abdominal incision and a
left cervical incision, whereas the latter requires pos-terolateral
thoracotomy, an abdominal incision, and, finally, a left cervical incision.
Parts of the proce-dure may be performed using laparoscopy or VATS. Monitoring of arterial and central
venous pressure is indicated. Multiple large-bore intravenous access, fluid
warmers, and a forced-air body warmer are advisable. During the trans hiatal
approach to esoph-agectomy, substernal and diaphragmatic retractors can
interfere with cardiac function. Moreover, as the esophagus is freed up blindly
from the poste-rior mediastinum by blunt dissection, the surgeon’s hand
transiently interferes with cardiac filling and produces profound hypotension.
The dissection can also induce marked vagal stimulation.
Colonic interposition involves forming a
pedi-cle graft of the colon and passing it through the pos-terior mediastinum
up to the neck to take the place of the esophagus. This procedure is lengthy,
and maintenance of an adequate blood pressure, cardiac output, and hemoglobin
concentration is necessary to ensure graft viability. Graft ischemia may be
her-alded by a progressive metabolic acidosis.
Postoperative ventilation will often be
used in patients undergoing esophagectomy, because so many of them will have
coexisting cardiac and pul-monary disease. Postoperative surgical
complica-tions include damage to the phrenic, vagus, and left recurrent