Primary esophageal dysfunction is seen at the pharyngoesophageal junction or on the esophageal body and at the esophagogastric junction. Cricopharyngeal myotomy is the preferred treatment offered to patients with oropharyngeal dysphagia of various causes. Esophageal body myotomy and the modified Heller myotomy aim at controlling symptoms resulting from primary esophageal motor disorders. These operations, even if successful in the majority of patients, can be responsible for significant morbidity and even mortality.
Operations on the Pharyngoesophageal Sphincter
Idiopathic Oropharyngeal Dysphagia
This form of idiopathic dysphagia affects the cricopharyngeus but has no neurologic or muscular condition to explain it. It is seen as an obstructive upper esophageal sphincter by itself or accompanied by its complication, the pharyngoesophageal or Zenker diverticulum. The cause for the muscle abnormality resulting in this constrictive and obstructive condition remains unknown. In the previous era, when no antibiotics were available, it was considered a treacherous problem where inflammation, perforation, mediastinitis, tracheoesophageal fistulas, and carcinoma formation could be expected when untreated. These complications are rarely seen today. Still, 61% of patients treated today complain of dysphagia and 17% mention aspiration episodes and pulmonary symptoms.10 Complications at operation for Zenker diverticulum may first be related to poor exposure. We prefer an incision along the anterior border of the sternocleidomastoid muscle, which allows wide exposure of the pharyngoesophageal junction. Small oblique incisions along the skin lines are limiting. These incisions were used in all the patients presenting with an incomplete myotomy that had failed to improve the oropharyngeal dysphagia.11 Sacrifice of the superficial branch of the cervical cutaneous nerve results in hypoesthesia and paresthesia of the ipsilateral submandibular area. This may subside over time.
The diverticulum, if large, is usually visualized under the buccopharyngeal fascia, the fibroareolar tissue covering the posterior pharyngoesophageal junction. As the majority of the diverticula seen today are smaller than 3 cm, they can be easily missed if this fascia is not opened, allowing protrusion of the diverticulum. Once exposed, its tip is seized with a small Duval clamp and lifted to allow the safe insertion of an intraesophageal bougie. This bougie serves as a stent to support the myotomy, while also protecting the esophageal lumen integrity. As diverticulectomy alone for a Zenker has been reported to result in a high recurrence rate over time, a myotomy or myectomy of the pharyngoesophageal junction is considered the essential part of the treatment whereas diverticulectomy or diverticulum suspension is seen as treatment for the complication of the dysfunction.
Mucosal perforation during the myotomy is usually recognized and repaired using small resorbable sutures. When the diverticulum is resected, the endoluminal bougie is there to prevent narrowing of the esophageal lumen during the resection. The resection line is usually made transverse. When the diverticulum is suspended, its tip is usually tied to the transected muscle margin of the hypopharynx. Fixation to the prevertebral fascia has been seen to cause fasciitis and osteomyelitis as the sutures made through the tip of the diverticulum are considered contaminated. To be complete, a cricopharyngeal myotomy must include the fibers of the inferior constrictor of the pharynx, the cricopharyngeus, itself, and a small portion of the cervical esophagus musculature. The cut margins of the myotomy must allow outpouching of the mucosa over 50% of the circumference to avoid reclosure of the myotomy.
Postoperative complications may be significant. This is not only related to the technique, but also to age as a majority of those patients are elderly and frail. Wound infection and fistula formation are the most frequent complications seen. For a one-stage diverticulectomy, the reported infection rate was 3%, with half of these patients showing a fistula. In our own experience, with close to 100 patients, infection was the most frequent complication. The fistula rate was 1.5%. The Mayo Clinic experience suggests a recurrent nerve palsy in 3% of their 888 patients.12 When reoperated, however, patients can expect the morbidity to increase to as high as 20%, explained by a more difficult mobilization of structures. When a fistula occurs, wide drainage of the wound is preferred as a first step. If there is no spontaneous early closure, a pedicled muscle flap of the sternocleidomastoid muscle is used to repair the fistula.
Recurrences were seen in 7% of Payne's experience with 164 patients followed 5 to 14 years. Nicholson13 in a radiologic follow-up of 20 patients showed that 13 had a recurrent pouch. Hansen et al.14 saw recurrences in 3 of 19 patients, Bertelsen and Aasted15 in 14 of 68 cases, and Einarsson and Hallen16 in 17 of 20 patients. Pouch formation probably develops over a significant period of time. This emphasizes that long-term radiologic documentation is necessary if objective results are to be obtained. When only cricopharyngeal myotomy is offered to treat the diverticulum, less than satisfactory results are found in patients in whom a small but dependent pouch persists.
Endoscopic esophagodiverticulostomy had initially been popularized by Dohlman using coagulation and, later, using laser to create a single lumen between the diverticulum and the cervical esophagus.17 The use of surgical linear staplers has gained popularity in recent years. Initially proposed for high-risk patients, it has now been used in large reported series. Although clinical results seem less satisfactory, the complication rate is low. Decreased operating time and avoidance of recurrent nerve injury are often proposed as advantages. Chang et al.18 report a 2% complication rate without mortality. These include dental complications (7%), fever (4%), aspiration pneumonia (0.7%), and esophageal perforation (0.7%). Transient cord paralysis was seen in one patient. Case and Baron19 reported minor bleeding in 23%, perforation in 27%, and neck abscesses in 4.5% of treated patients.
Neurologic, Myogenic, and Idiopathic Dysphagia
Table 32-2 describes the morbidity and mortality resulting from cricopharyngeal myotomy for indications other than Zenker's diverticulum. With proper selection, significant improvement in oropharyngeal dysphagia can be obtained.
Table 32-2Cricopharyngeal Myotomy Morbidity and Mortality ||Download (.pdf) Table 32-2Cricopharyngeal Myotomy Morbidity and Mortality
| ||NEUROLOGIC ||MYOGENIC ||IDIOPATHIC |
|28 PATIENTS ||153 PATIENTS ||129 PATIENTS |
|Technical Complications |
| Mucosal tear ||1 ||9 ||0 |
| Fistula ||0 ||0 ||2 |
| Infection ||1 ||3 ||12 |
|Systemic Complications |
| Pulmonary ||6 ||10 ||6 |
| Cardiac ||3 ||8 ||7 |
| Urinary ||3 ||3 ||9 |
| Metabolic ||2 ||3 ||3 |
| Mortality ||0 ||4 ||0 |
Although in neurologic patients the dysphagia is usually related to poor coordination between swallowing, pharyngeal contraction, and upper sphincter relaxation, patients with muscular dysphagia have symptoms resulting from poor pharyngeal contraction and propulsion with incomplete sphincter opening. Adequate symptom documentation and quantification with videoradiologic assessment are essential for appropriate patient selection. Complications related to the myotomy in these patients are less frequent than in Zenker's patients. Mucosal penetration, although frequent, is rarely followed by infection or fistula formation. Campbell et al.,20 however, report pharyngeal leaks in 8% of their patients. In our experience, primary repair with resorbable sutures or a pedicled muscle flap is usually satisfactory to prevent this complication. Persistent aspiration with pulmonary complications may have to be approached by a permanent tracheostomy with laryngeal diversion or resection. Mortality was seen mostly in the muscular dysphagia group (4%) and is always secondary to severe lung infection.
Operations on the Esophageal Body and the Lower Esophageal Sphincter
Achalasia is the most frequent and best described esophageal motor dysfunction. The diagnostic criteria are well established and recently three types of the same abnormalities were proposed to classify these dysfunctions.21 A wrong diagnosis remains a possibility as a number of medical conditions can mimic this primary disorder clinically, radiologically, and manometrically. Pseudoachalasia by an obstructive subcardial lesion must especially be ruled out before reaching the diagnosis. A comprehensive approach to investigation is essential to allow an objective diagnosis in all patients and prevent misdirected therapy.
Preoperative Complications They are related primarily to the consequences of esophageal retention/obstruction. Aspiration pneumonia was reported in 10% of patients by Ellis and Olsen22 and Clouse and Lustman,23 whereas Effler et al.24 observed nocturnal aspiration in 24% of their patients and Black et al.25 in 46%. Olsen26 reported a 10% incidence of pulmonary infection in their series, including a chronic form of mycobacterial infection suspected to be caused by the fatty supernatant found frequently in the achalasic esophagus. Acute airway obstruction may require rapid intubation. This is seen mostly with end-stage achalasia. One of the dreaded complications is massive aspiration during the induction of anesthesia. Allen and Clagett reported that one of the two deaths in their series resulted from that complication.27 Whenever an esophagus is dilated with documented retention, a safe approach remains a liquid diet for the days preceding the operation, emptying and lavage of the esophagus the morning of the operation, and awake intubation by the anesthetist before the induction of anesthesia.
Intraoperative Complications These are related to the technique and to the type of approach selected. Even to this day there is no consensus on what an ideal myotomy for achalasia should be. The modified Heller myotomy in use today varies significantly in length on the esophagus and in its extension on the gastric wall. Independent of the surgical approach selected, the principles for treatment should be identical: remove the obstructive effect of the lower esophageal sphincter. The overall mortality reported varies between 0.7% and 2.8% with smaller series showing a higher mortality.28 Mucosal perforations during the myotomy are usually inadvertent and immediately repaired using resorbable sutures. Andreollo and Earlam29 documented mucosal penetration in 1.1% of their review of over 5000 myotomies. This led to a fistula and empyema in 0.4% of all patients. Moreno González et al.30 found a similar prevalence in their European study. In most large series, the morbidity is related to mucosal penetration. Ellis31 reported it in 25 of their 262 patients whereas Okike et al.32 observed leaks and sepsis in 1% of their 468 patients. Repeat myotomies are at higher risk of mucosal damage.33-35 Little et al.36 proposed a posterior myotomy in this situation to improve the safety of the operation. Mortality in surgery for achalasia is usually the immediate consequence of fistula formation and sepsis. In view of the severity of this technical mishap, added protection after the repair is indicated with the use of a partial fundoplication, or pleural or muscular flap, depending on the level of the mucosal damage in the myotomized area.
Persistent dysphagia immediately after the operation usually results from an incomplete myotomy.37 Reoperation gives satisfactory results in 75% of the group.
Paraesophageal hernias are usually the result of a disrupted hiatus after the operation. This complication has been reported frequently in open surgery series.38-41 Immediate reoperation is indicated to prevent complications on the herniated stomach or on the mucosa denuded of its muscularis. Anatomic restoration of the hiatus with a partial Belsey-type fundoplication should allow a proper seal of the abdominal cavity from the chest.
Late Complications Complications can result from altering the function of the lower esophageal sphincter;38-41 or when esophageal body dysfunction is not modified by the operation and aperistalsis persists; an insufficient myotomy fails to relieve dysphagia; or adequate sphincter division exposes to the possibility of reflux disease.
When dysphagia recurs 6 months to 1 year after the operation, this usually suggests healing of the myotomy.31,42 The absence of esophagitis at endoscopy with a competent lower esophageal sphincter on manometry and at endoscopy suggests either rehealing or an incomplete myotomy. Difficulty in identifying the myotomy zone at the operation usually confirms that impression. Periesophageal sclerosis with hyalinization also has been reported by Fekete and Lortat-Jacob37 and Peracchia et al.43 Recurrent dysphagia is also seen with late-stage achalasia. Esophageal cancer must be ruled out.
Reflux esophagitis and stricture are the most frequent complications of the modified Heller myotomy. Extension of the myotomy on the gastric wall is considered important but if the myotomy extends more than 2 cm on the stomach, reflux disease will result in all patients.44,45 Reflux disease increases with the passage of time: 24% at 1 year, 48% at 10 years, and stabilization at 52% after 13 years. At that time, 19% of patients present with a stricture. The more objective the evaluation, the higher the prevalence of reflux complications on the esophageal mucosa. Failed myotomies are predominantly caused by peptic esophagitis. Long-term reflux exposure may induce the appearance of columnar-lined metaplasia with its related morbidity. Ulcerations, fistulas, strictures, perforations, and malignant transformation may ensue if the condition goes untreated.
Diverticulization of the myotomized esophagus is another potential problem. The longer the myotomy on the esophageal body, the higher the chances of observing progressive diverticulization of the mucosa through the myotomized area. This has been observed in over 60% of patients with a long myotomy. It happened in patients with a total fundoplication at the end of their myotomy but also in those who had a partial fundoplication of the Belsey type.46,47 We have now reduced the length of the myotomy to 4 cm, when the lower esophageal sphincter alone is divided. Extension on the stomach is 2 cm. The myotomy zone is then completely covered by the partial fundoplication. Dysphagia is well controlled, the denuded mucosa is protected, but reflux control remains imperfect.
The advent of minimally invasive operations has significantly influenced the management of achalasia patients. This approach, however, must respect the same principles for treatment. The same objective reassessment must take place to rule out the complications that have been documented in open surgery series. Achalasia patients are at increased risk of developing a cancer. This risk is about 140-fold than that of the general population.48 This has not been modified by cardiomyotomy. When achalasia is untreated for more than 20 years, the esophageal mucosa irritation by the stagnant and putrescent food is seen as increasing the risk for transformation significantly.49 Once treated by myotomy, 1.5% to 2.2% of the patients can be expected to develop an esophageal cancer.50,51
Spastic or hyperdynamic esophageal disorders include diffuse esophageal spasm, hyperperistalsis, and the hypertensive lower esophageal sphincter. The importance of obtaining an objective and reliable diagnosis cannot be overemphasized. A wrong diagnosis and a wrong orientation in treatment are bound to produce poor results.52
The high strung personality in these patients requires special care and evaluation. Following psychological evaluation and treatment with calcium channel blocking agents and anxiety medication, endoscopic botulinum injection can be considered.53 Surgery is never a first approach in treatment. When an epiphrenic diverticulum is present, most patients are found to have an associated spastic disorder. Treatment in that condition must be similar to that of achalasia. Division of the lower esophageal sphincter must accompany the esophageal body myotomy to the upper level of the diverticulum as the lower sphincter shows intermittent abnormal relaxation. Failure to extend the myotomy on the stomach wall may result in significant morbidity and even mortality, especially if a diverticulectomy has created a suture line on the esophageal body.54 The complications of myotomy for spastic disorders are similar to those seen and reported for achalasia.