Magnetic sphincter augmentation is increasingly utilized as alternative to laparoscopic fundoplication in the treatment of patients with gastroesophageal reflux disease.23 Sliding hiatal hernias are still much more common than paraesophageal hernias, but the prevalence of the latter seems to be increasing in the United States.24 In patients with type I hiatal hernias the esophagogastric junction has migrated above the level of the diaphragm whereas in those with paraesophageal hernias, there is relative preservation of posterolateral phrenoesophageal attachments around the EGJ.25 The inherent differences of paraesophageal and large siding hernias result in varying disease manifestation, necessity for specific surgical maneuvers and forms of postoperative failure. Surgical repair of type I hiatal hernias is indicated in case of symptomatic reflux disease. In contrast, surgical repair of symptomatic paraesophageal hernias is indicated to reduce the risk for severe complications which is estimated to be 1% per year.26 The performance of an antireflux procedure is an essential part of any PEH repair as it reduces the risk of hernia recurrence and eliminates gastroesophageal reflux.27
In this study, we compared the clinical outcomes and surgical complexity of magnetic sphincter augmentation and hiatal hernia repair in patients with paraesophageal hernia to those with large sliding hernia. An important finding of our study is that magnetic sphincter augmentation and hiatal hernia repair results in favorable outcomes in patients with PEH and those with LHH. Quality of life improved significantly in all patients after MSA and rates of postoperative pH normalization and freedom from PPI were comparable between PEH and LHH patients. While encouraging outcomes of magnetic sphincter augmentation in patients with larger sliding hernias have been reported previously7, 8, 28, the present study is the first to selectively evaluate the efficacy of MSA in patients with PEH and compare it to a matched group of patients with LHH. Furthermore, postoperative reflux control of PEH patients treated with MSA in our cohort was comparable to published outcomes following laparoscopic fundoplication.29 These findings indicate that MSA represents an effective alternative to laparoscopic fundoplication in PEH patients. The choice of antireflux procedure is partially based on esophageal body motility function. Negative experiences with historic circumferential devices placed around the GI tract such as the Angelchik device raised concerns regarding the effect of the Linx device on esophageal peristalsis. However, early data suggest that while MSA leads to increased esophageal outflow resistance esophageal motility remains unaltered due to a compensatory increase in contractile vigor.30
In this series, low recurrence rates of < 20% in both hernia groups were detected at an intermediate term follow up of 2 years. Similar to other MSA studies, the majority of recurrences consisted of asymptomatic small sliding hernias without device dislocation8. Revisional surgery is rarely indicated in patients with recurrence and is relatively uncomplicated compared to repair of a herniated fundoplication which requires dissection of the wrap from the hiatus and esophagus.8 While long-term results have to be awaited, our recurrence rates of < 20% following MSA compare favorably to published recurrence rates of over 50% after laparoscopic PEH repair at a 5 year follow up.13 It has to be emphasized that recurrences observed in patients with MSA mostly consisted of small, sliding hernias which rarely require revision.
The results of this study highlight greater technical complexity of the repair of a paraesophageal hernias compared to large sliding hernias. More adjunct surgical maneuvers were required for the repair of paraesophageal hernias. A trend toward more need for extensive mediastinal dissection was also detected in patients with PEH. Furthermore, a trend toward longer operative times with increasing hernia size in LHH patients was detected (median OR time: hernia size ≤ 5cm, 88min (IQR, 74–94) vs. hernia size > 5cm, 118min (IQR, 68–143); p = 0.545).
Patients with PEH were more likely to require overnight stay after surgery. This is likely reflective of presence of other comorbidities in this group. The two groups were matched in regard to age, eliminating older age as an explanation for longer hospital stay in PEH group. Previous studies have shown higher rate of cardiopulmonary comorbidities from chronic, larger volume compressive effects of paraesophageal herniation.31
The overall operative time did not differ significantly between the two hernia groups, however inherent differences between these two types of hernia led to allocation of surgical time to different steps of surgery in each group. Patients with LHH had a higher rate of preoperative esophagitis. This indicates a more severe reflux disease in these patients compared to those with PEH. Longstanding exposure of distal esophagus to irritant acidic gastric juice in patients with LHH may result in transmural esophageal wall inflammation. This may then result in creating more chronic inflammation and adhesions around the EGJ and distal esophagus, making the dissection of these area more challenging and time consuming in patients with LHH. A recent study demonstrated that MSA leads to significant clinical improvement across the GERD severity spectrum.32 Contrary, successful surgical repair of paraesophageal hernia require complete reduction of hernia sac, this is usually a lengthy step of surgery that requires a more extensive mediastinal dissection often to the level of inferior pulmonary vein.
Laparoscopic PEH repair is proven to be challenging and technically demanding.27 A successful repair requires a tension-free hernia repair with minimizing both, axial and radial tensions.33 Several adjunct procedures and technical modifications have been described in the literature to achieve a tension-free repair. Axial tension can be reduced by performing extensive mediastinal dissection, vagal nerve or EGJ fat pad mobilization and Collis gastroplasty. The wedge-fundectomy Collis gastroplasty has been established as simple yet effective tension-reducing technique in patients with shortened esophagus of intraabdominal length < 3cm.34 To ensure an adequate diameter of the “neoesophagus”, the esophageal lengthening procedure is performed over a bougie.35 Previous studies have shown that the performance of a Collis gastroplasty in patients with shortened esophagus is safe and effective while reducing recurrence rates.34, 36 However, as reflected by our results, an extensive mediastinal dissection usually allows mobilization of adequate length of intraabdominal esophagus, this eliminated the need for Collis gastroplasty in our practice.
Another challenge in repair of PEH is crural reapproximation. Radial tension, particularly in patients with wide splayed crura, is a major culprit for recurrence after laparoscopic PEH repair. Adjunct tension-minimizing techniques include crural relaxing incisions, central tendon release and mesh reinforcement of the crural repair. Critical assessment of the hiatal tension after suture cruroplasty should guide the choice of one or more techniques. Mesh reinforcement of laparoscopic PEH repair is controversial and it plays a subordinate role in our practice. Despite reduced recurrence rates after reinforcement with permanent, synthetic mesh, associated complications such as erosion, mesh infection and increased rates of postoperative dysphagia discouraged its application.37 A safer alternative is the use of an absorbable mesh. However, despite promising early results, long term outcomes did not demonstrate significant differences in recurrence rates between PEH patients that were treated with and without mesh reinforcement.13, 38 Recently, encouraging outcomes of laparoscopic PEH repair with the use of newer biosynthetic absorbable mesh (Poly-4-hydroxybutyrate; Phasix-St-mesh) has been reported.24 The combination of mesh reinforcement and other tension-reducing techniques in that study resulted in a low rate of hernia recurrence and no mesh-related complications at short term follow up. However, selective mesh reinforcement is unlikely to overcome extensive hiatal tension.27 Thus, the use of crural relaxing incisions on the right side, or less commonly left side, can prove beneficial. Using the harmonic scalpel, a full-thickness incision of the right crus parallel to the inferior vena cava (IVC) is recommended. A 3mm cuff of tissue is spared along the IVC which is later used for fixation of a PTFE patch which covers the diaphragmatic defect.39
Paraesophageal hernias are reported to occur more commonly in females of older age. Similar gender and age distribution among the two groups in this series is the result of the matched study design. Outcomes of PEH patients were compared to a sex and age matched control group of large sliding hernias to eliminate the confounding role of these factors and add to the strength of our study. However, we acknowledge that the PEH patient population of this study which included only those selected to undergo MSA might not be a comprehensive representative for the overall PEH patient population. Other limitations of this study include its retrospective nature and the relatively small samples sizes of the groups. Further multi-center studies with a larger patient population are necessary to evaluate long-term outcomes and recurrence rates after MSA and hiatal hernia repair in patients with paraesophageal hernia.