Minimizing complications after minimally invasive surgery for epiphrenic diverticula of the esophagus: technical tips

Introduction

Esophageal diverticula are an uncommon disorder with an incidence less than 4% in endoscopic and radiologic series^[1]. They are located above the sphincters that delimit the esophagus (epiphrenic diverticulum for the lower esophageal sphincter and Zenker’s diverticulum for the upper esophageal sphincter) and are secondary to dysfunction of these sphincters. This leads to increased pressure and herniation of the mucosa through gaps in the muscular layer (pulsion pseudodiverticulum) or in the esophageal body (Rokitansky diverticulum), classically linked to the tuberculosis era when inflamed mediastinal lymph nodes were believed to create adhesions to the esophageal wall (true traction diverticulum)^[2], although recent studies also showed the role of dysmotility in the genesis of these diverticula^[3].

Zenker’s diverticulum is located in the area of the upper esophageal sphincter and treated by either an open cervical or an endoscopic approach^[1]. Midthoracic diverticula are usually asymptomatic^[3] and represent only 15% of the esophageal diverticula^[4]. Intramural pseudodiverticulosis is a rare condition mostly linked to the mucosa^[5]. These conditions are not treated here.

Epiphrenic diverticulum (ED) [Figure 1] occurs within the distal 10 cm of the esophagus^[2]. It is associated to esophageal dysmotility^[6]. The most common named esophageal motility disorder linked to this disease is achalasia^[7]. ED is usually treated by a minimally invasive approach, but some series show suboptimal outcomes with up to 23% leak rate and 20% need for a reoperation^[8]. In this series dedicated to Postoperative Complications and Recovery of Minimally Invasive Esophageal Surgery, we may propose three points for discussion as technical tips to improve outcomes and minimize complications in the treatment of ED: conservative approach in selected cases, the abdominal approach when surgical therapy is indicated, and the isolated treatment of the esophageal dysmotility without diverticulectomy.

Figure 1. Barium esophagram disclosing an epiphrenic diverticulum (arrow)

Abdominal approach

Most authors advocate the surgical treatment for ED with a cardiomyotomy (Heller’s operation) and diverticulectomy^[8-10]. This form of treatment was historically performed through a thoracotomy. In the era of minimally invasive surgery, thoracoscopy replaced thoracotomy as the preferred approach^[9]. The thoracic approach gained popularity due to easy access to the diverticulum, especially in situations when its ostium is more proximal into the esophagus. The thoracic route has some disadvantages as compared to the abdominal approach that goes farther than the pulmonary morbidity and pain. The myotomy is associated to worse outcomes when performed through the chest as compared to the abdominal route, especially due to a high rate of gastroesophageal reflux^[11]. In addition, the development of staplers made easier the resection of the diverticulum via laparoscopy^[9]. These advantages shifted the preference of modern authors to the laparoscopic route^[8]. In addition, the laparoscopic approach allowed the performance of a partial fundoplication after the myotomy to prevent pathologic reflux.

When outcomes are compared, disease recurrence is rare for both approaches^[8] and the results seem to be similar for thoracoscopy and laparoscopy^[8,12-14]. If diverticulectomy is considered important (due to symptoms) after a laparoscopic myotomy and partial fundoplication, a thoracoscopic diverticulectomy is safer.

Some technical tips may result in better outcomes^[10]. First, dissection of the upper border of the diverticulum and of its neck is the most challenging aspect of the laparoscopic route. Even though the diverticulum may appear to be located high in the esophagus, dissection of adhesions to surrounding tissues and sufficient traction of the diverticulum and esophagus with a Penrose drain circling the esophagogastric junction frequently allows dissection of high diverticula from below. It is important to dissect the neck of the diverticulum free of the surrounding tissue and to clearly identify the muscle layers. It must be remembered that ED is pseudodiverticulum, thus muscular fibers cannot be found at the diverticulum itself. Some authors add an extra port for further assistance^[15].

If the diverticulum will be resected, it is better performed on the opposite side of the diverticulum to avoid interference with the resection and the muscle closure at that site. If the diverticulum will not be resected, myotomy can be performed at the level of the neck of the diverticulum and extend onto the gastric wall as in a Heller myotomy for achalasia. For the diverticulectomy, a 50-56-F bougie is placed inside the esophagus to avoid narrowing of the lumen when the stapler is applied. Reticulating staplers should be preferentially used to facilitate optimal positioning across the neck of the diverticulum, and the staple height should be appropriate for the thickness of the tissue at the transection site. The muscle layers should be approximated over the staple line with interrupted stitches. A partial fundoplication completes the procedure [Figure 2].

Figure 2. Laparoscopic resection of epiphrenic diverticulum (left). The operation also includes a myotomy and partial fundoplication, either a Dor (a) or Toupet (b). Reproduced from Reference^[1] with permission by Springer

Conclusion

ED treatment may be associated to high morbidity and mortality in up to 4% of cases^[18]. Thus, these patients should be preferably treated in centers with a high volume and expertise in esophageal surgery. A conservative nonoperative approach is acceptable in asymptomatic or oligosymptomatic patients since the risk for severe aspiration and cancer is exceptionally low. When surgery is indicated, the laparoscopic approach should be favored as results are similar to the thoracoscopy approach, but it allows the performance of a partial fundoplication to prevent pathologic reflux. Treatment of the underlying motor disorder is imperative to relieve symptoms and prevent leaks when a diverticulectomy is performed^[17], but the resection of the diverticulum may not to be necessary when they are small or very high up in the mediastinum. A treatment selection tree diagram is provided in Figure 3. Endoscopic therapy is waiting a careful evaluation but seems to be a promising alternative.

Figure 3. Schematic treatment selection tree diagram for epiphrenic diverticula