Clinical Presentation and Diagnosis
Leiomyomas are the most common benign tumors of the esophagus, accounting for more than half of all benign tumors in some reports.8,9 They typically present between the ages of 20 and 69 years, and the peak incidence is between the third and fifth decades. As with other benign tumors, they often are asymptomatic. Patients with symptoms may describe dysphagia, weight loss, chest pain, or early satiety. The lesions grow slowly, arise from smooth muscle cells, and are predominantly found in the lower two-thirds of the esophagus. Leiomyomas rarely ulcerate or bleed. There is some controversy regarding the malignant potential of these lesions.9
Leiomyomas have a typical appearance on barium swallow as rounded, smoothly marginated intraluminal filling defects. Large tumors show an acute angle with the wall of the esophagus and the tumor edge. A contrast swallow is useful for identifying the level and laterality of the lesion for surgical planning. Endoscopy may be useful in identifying the location of the tumor. Endoscopic characteristics of leiomyomas include normal-appearing overlying mucosa, mobile lesions, and projection into the lumen (Fig. 29-3A). Endoscopic forceps biopsy is contraindicated in patients with leiomyomas since it has not been shown to assist in obtaining a definitive diagnosis and puts patients at increased risk for complications such as bleeding, infection, and perforation at the time of enucleation. On EUS, these lesions are smooth, well-circumscribed, hypoechoic tumors originating from the fourth layer with an intact and uninvolved overlying mucosa10 (Fig. 29-3B). EUS provides the opportunity for FNA, which has been used in some case reports to differentiate between leiomyomas and leiomyosarcomas, although studies investigating the safety and efficacy of this technique are still pending.
Leiomyoma on flexible esophagoscopy (A) and endoscopic ultrasonography (B).
Surgical excision is indicated in patients with symptomatic lesions. In asymptomatic patients, resection historically has been the treatment of choice and is recommended for tumors with increasing size, mucosal ulceration, or when tissue is needed to confirm the diagnosis. Resection is often recommended for lesions >4 cm in asymptomatic patients regardless of whether other abnormalities indicating increased risk are present. Observation of small, characteristic, asymptomatic lesions with serial EUS every 1 to 2 years has been recommended by some authors.11
Endoscopic Resection for Leiomyoma
Endoscopic treatment can be considered for a limited group of lesions originating from the muscularis mucosa with intraluminal growth or polypoid growth patterns.12 Tumors smaller than 2 cm that are pedunculated may be resected via endoscopic lumpectomy, while larger lesions may be treated with ethanol injection followed by lumpectomy. Lumpectomy is performed with a snare wire and suction cylinder after dissecting the tumor free from the submucosa using hypertonic saline injection. For larger lesions, multiple ethanol injections are administered over several weeks. Use of both of these techniques is more prevalent in Japan and is not yet common in Western countries. Reports have shown complete resolution of symptoms, negligible mortality, and low rates of recurrence.12
Surgical Enucleation for Leiomyoma
The location of the tumor should be evaluated preoperatively with endoscopy to facilitate surgical planning. Endoscopy should be available in the operating room for localization, transillumination, and leak identification during resection. The patient is positioned to facilitate either a right or left approach according to the level of the lesion (see below). Double-lumen endotracheal intubation is used to improve intraoperative exposure if a transthoracic approach is selected. Laparoscopy or an upper midline laparotomy may be used for distal esophageal lesions.
Tumors in the lower esophagus may require mobilization of the cardia and disruption of the hiatal structures. Performance of a simultaneous antireflux procedure should be discussed with these patients before surgery. Patients with preoperative symptoms of reflux should undergo preoperative evaluation including pH monitoring and manometry (see Chapter 37). Concomitant antireflux procedures are also recommended in these patients.
Transthoracic enucleation has been the procedure of choice for removal of most leiomyomas.11,13 Open thoracotomy or video assisted thoracic surgery (VATS) may be used according to surgeon preference. Tumors in the upper two-thirds of the esophagus are usually accessed from the right side, while lower third lesions are removed from either the left or the right side. After the esophagus is exposed, the lesion is identified using palpation and/or transillumination with endoscopy. The esophagus is mobilized sufficiently to identify the circumferential extent of the tumor. The azygos vein may be divided as necessary to gain adequate exposure. A longitudinal myotomy is then made overlying the tumor; this incision can be smaller than the length of the tumor. The leiomyoma will appear as a smooth, avascular, gray-white mass. Blunt dissection, hook cautery, and scissors are used to mobilize the tumor from the muscle layer and underlying submucosa. A traction suture may be placed in the tumor to assist in freeing it from the underlying tissue. Endoscopic visualization can be used during dissection to identify any mucosal damage.
After the tumor is removed, the endoscope is used for insufflation, possibly using distal occlusion of the esophagus. The esophagus is submerged in saline to observe for any air leak, which is an indication of a mucosal leak. Preoperative endoscopic biopsy predisposes to scar tissue formation that makes the tumor more adherent to the mucosa and increases the risk of intraoperative mucosal damage. Mucosal damage identified during surgery is repaired in two layers with absorbable sutures. In this case, delay of oral feedings for several days should be considered. After mucosal integrity is confirmed, the muscular layer is approximated without tension. Some authors suggest not closing the muscular layer if there is evidence of significant trauma after resection. A flap of pleura, pericardium, diaphragm, omentum, or pedicled intercostal muscle may be used as a buttress for the closure, but this is rarely necessary if the muscle layer is preserved in good condition and the closure of the muscle layer is secure. Failure to close the muscle layer or otherwise reinforce the area of myotomy may predispose to the development of a pseudodiverticulum (Fig. 29-4).
Pseudodiverticulum after enucleation for leiomyoma.
Postoperative Care and Complications
Nasogastric tubes are used according to surgeon preference, but likely provide little benefit. Patients without mucosal damage or evidence for a leak may be started on a clear liquid diet on the day of surgery, while feeding should be deferred for at least 1 day in patients who require mucosal repair. The diet is advanced to pureed and then mechanical soft foods over 7 to 10 days. Routine postoperative imaging of the esophagus is not required.
Enucleation of leiomyomas gives excellent results, with 89% to 95% of patients free of symptoms at 5 years.11,13 Mortality rates range from 0% to 1.3%. Postoperative complications include acid reflux, esophagitis, fistula, stenosis, and diverticulum formation. Some of these may result from impairment in esophageal propulsion and inability to clear acid after resection of large tumors when the muscle layer is not adequately reapproximated.
Segmental esophageal resection should be considered for large tumors (>8 cm), circumferential tumors, those with significant distortion of the musculature, or those with high suspicion for leiomyosarcoma based on imaging or FNA. It should also be considered in patients undergoing enucleation when there is extensive damage to the esophageal mucosa predisposing the patient to a high risk of postoperative leak. Preoperative planning in all of these patients should include consideration of conduit reconstruction. Reconstructive options include gastric pull-up or colonic or jejunal interposition. Preoperative preparation and positioning are similar to those for enucleation procedures. Techniques and postoperative care for segmental esophageal resection are discussed in Chapters 15-22.