An upper endoscopy should be performed on all patients prior to antireflux surgery. The primary goal is to evaluate for malignancy, Barrett esophagus, peptic stricture, ulcers, esophagitis, and/or gastritis, but the findings of this study can also be used to help determine the risk for SE. While contrast radiographs can evaluate the distance between the GEJ and diaphragmatic crura, this measure is much less clear during endoscopy. For this reason, the presence of a hiatal hernia observed endoscopically should not be given as much weight as the findings on fluoroscopic evaluation. It should be kept in mind that radiographs provide the best anatomic description, whereas endoscopy should be used primarily as an examination of intraluminal pathology.

Yano and colleagues conducted an analysis of preoperative endoscopic findings in patients who went on to require an esophageal lengthening procedure for SE and compared these with patients who underwent antireflux surgery without SE [17]. They found that the presence of a peptic stricture on endoscopy was a significant risk factor for SE, with an odds ratio of 7.5 compared with non-SE patients. Interestingly, there was no difference in the rates of esophagitis on endoscopy between the two groups, a result corroborated by a second study [18]. These findings support the concept that SE is not caused by acute mucosal injury to the esophagus, but rather results from the chronic healing and stricture process that comes with repeated insults over a sustained period of time.

Esophageal length was measured endoscopically by Yano et al. and was defined as the scope distance from the incisors to the GEJ [17]. There was an association of increased length with increased patient height, so in order to account for this baseline anatomic variation, esophageal length (in cm) was divided by height (in meters) to produce an “esophageal length index” (ELI). Based on these values, a cutoff of ELI < 19.5 was determined to produce a specificity of 95 % in predicting SE preoperatively. This resulted in a positive predictive value of 81 % and a negative predictive value of 83 %, although a sensitivity of only 56 %.

A contrast radiograph (i.e., barium esophagram or “upper GI series”) should also be included in the routine evaluation of any patient with a sizable hiatal hernia prior to LARS. This study provides the best anatomic evaluation of the esophagus, GEJ, diaphragmatic hiatus, stomach, and their relationships to one another. The first thing that should be noted is the presence of a hiatal hernia, demonstrated by a GEJ that is situated superior to the diaphragmatic hiatus. The precise distance between these two points should be measured. This requires the X-ray images to be calibrated to a ruler, which although intuitive, is not the case in all fluoroscopy protocols and systems. The width of the hiatal defect should also be measured, and the presence of the stomach and/or other abdominal viscera above the hiatus noted, defining the presence of a PEH. If a hiatal hernia or PEH is present, it is important to obtain a series of x-ray images over time and throughout the course of several swallows, in order to elucidate whether the GEJ is mobile in relationship to the hiatus (i.e., “sliding”) or fixed in a supradiaphragmatic position. A type III PEH (where both the GEJ and stomach body protrude through the hiatus) increases the risk for SE. Additionally, patients with a fixed GEJ are more likely to have a chronically incarcerated hiatal hernia, which will be less amenable to operative mobilization, and may further increase the likelihood of encountering a SE.

Gastal and colleagues retrospectively analyzed preoperative studies performed on patients prior to antireflux surgery, of whom 16 % required an esophageal lengthening procedure for SE [19]. They found that the presence of a hiatal hernia >5 cm (defined as the vertical distance between the GEJ and the diaphragmatic hiatus) was predictive of intraoperative SE, although with a positive predictive value of only 58 %. It should also be noted that patients in this series suspected of having SE preoperatively were approached via thoracotomy, whereas all other operations were performed laparoscopically, which introduces a potentially confounding variable into these data. In another study of patients who were all operated on laparoscopically, the same cutoff of a hiatal hernia >5 cm had a sensitivity of 66 % and a positive predictive value of 37 % for predicting SE [20].

Manometry provides the best functional examination of the esophagus and lower esophageal sphincter (LES), allowing for both qualitative and quantitative evaluation of esophageal peristalsis and LES basal and relaxation pressures. Some authors argue that manometry need not be included in the routine evaluation of patients prior to antireflux surgery. However, we prefer to obtain one if possible on all patients for several reasons. Although rare, patients presenting with what symptomatically appears to be GERD can have an underlying motility disorder such as achalasia, which will become apparent only on manometry. Additionally, many GERD patients will have subtle changes in both esophageal body and LES function. Non-specific spastic contractions can lead to postoperative symptoms that may cause dissatisfaction. A motility study allows preoperative counseling regarding this possibility [21]. As many patients will have some degree of dysphagia after their operation, it is also important to have a preoperative manometry to serve as a functional baseline, allowing the surgeon to more accurately evaluate the cause of any postoperative complaints.

In addition to these important functional descriptions, manometry provides anatomic delineations that can add to an analysis of the potential for SE. The most basic manometric determination is that of esophageal length, measured from upper to lower esophageal sphincter. Mittal and colleagues performed manometry on 32 patients with suspected SE preoperatively, based on the criteria of an irreducible hiatal hernia or peptic stricture. In this patient subgroup, a higher percentage of patients who required an esophageal lengthening procedure had a short esophageal length on preoperative manometry (defined as two standard deviations below the mean of healthy subjects), but this criterion had both a low sensitivity (43 %) and positive predictive value (25 %).

It should be noted that in this study, the manometric measurements were performed using the then-standard pull-through method. The recent technological advance of high-resolution manometry (HRM) has allowed these studies to provide a more detailed picture of both esophageal and LES function, as well as anatomic delineations. The HRM catheter has pressures sensors spaced at 1 cm intervals along its entire length, allowing for simultaneous measurements to be performed from UES to LES without need for catheter repositioning. This provides a more accurate anatomic picture, as length can be measured at a single point in time, as opposed to the pull-through technique of standard manometry which introduces the variables of both time and probe movement.

These differences become even more crucial in the setting of a hiatal hernia. HRM is able to detect fluctuations in esophageal length as the GEJ moves vertically in the case of a mobile hernia, in addition to measuring the distance between LES and the diaphragmatic crural contraction point [22]. The end result is a more complex anatomic picture that can help to corroborate radiographic and endoscopic findings to quantitatively assess the size and reducibility of a hiatal hernia, giving yet another indicator of the probability of encountering a SE intraoperatively. Other authors have suggested that decreased GEJ pressures and hypo or aperistalsis are also predictive of SE, and certainly the functional component of the esophagus as measured by HRM must be taken into account prior to any LARS [4, 23].

If a SE is suspected based on preoperative studies, it is important to make adequate preparations in order to be prepared to address it. Although we inform all patients undergoing LARS and PEH repair that an esophageal lengthening procedure may be necessary, this point is emphasized in patients with a higher suspicion for SE. The added perioperative risk of staple-line leak should be discussed, as well as the long-term outcomes of this modification to the procedure. It is equally important to inform the anesthesia and nursing teams so that all necessary equipment, such as endoscopic staplers and bariatric length laparoscopic instruments, is available and everyone is prepared for a potentially longer operation.

Although some authors argue that patients undergoing antireflux surgery who have a high likelihood of SE should be approached transthoracically [19], most surgeons today proceed laparoscopically in almost all cases. Some alterations are made to our routine LARS protocol, including the placement of a Foley catheter and administration of preoperative antibiotic prophylaxis, due to the increased potential for a longer operative time and inadvertent esophageal or gastric perforation. Operating room setup, patient positioning, and port placement in any LARS should be designed to facilitate easy access to, and visualization of, the esophageal hiatus and mediastinum. This is especially true when undertaking an operation that may include an esophageal lengthening procedure. Patients are positioned supine on a vacuum bean-bag in order to provide evenly distributed support and facilitate a steep reverse Trendelenburg tilt. The patient’s legs are abducted on padded straight leg boards and the surgeon stands between the patient’s legs, with the assistant to the patient’s right and the camera operator seated on a stool on the patient’s left side. An orogastric tube is placed to decompress the stomach.