Fig. 12.1
Annual volumes of paraesophageal hernia operations in a single academic practice
Hiatal hernias are classified as five types based on the relative position of the gastroesophageal junction (GEJ) to the hiatus and the nature of the hernia contents. The most common is Type I, or sliding hiatal hernia, characterized by cephalad displacement of the GEJ into the mediastinum. These rarely have symptoms related to the mechanical aspects of the hernia. The remaining types are considered true PEH. The rarest is Type II hernias, characterized by cephalad displacement of the fundus through the hiatus while the GEJ remains in its normal position. Type III hiatal hernias have cephalad displacement of both the GEJ and fundus. A type IV hernia is a hiatal hernia containing another organ, such as colon, pancreas, spleen, etc. And finally, we have categorized patients with post fundoplication mediastinal herniation as “Type V” hernias (Fig. 12.2).
Fig. 12.2
Types of hiatal hernia: (a) Type 1 or sliding hernia, (b) Type 2 or true paraesophageal hernia, (c) Type 3 or complex or “giant” hiatal hernia, (d) Type 4 paraesophageal with other organs herniated, (e) Type 5, post surgical herniation
Etiology and Pathogenesis
A paraesophageal hernia occurs when there is anatomic disruption of the crural diaphragm with progressive migration of abdominal contents (primarily the gastric fundus) due to the pressure differential between the abdominal cavity and the chest. PEH is therefore primarily a disease of the diaphragm and the phrenoesophageal ligament as opposed to a disease of the GEJ or a result of reflux. The exact nature of the biologic defect and whether it is truly a problem with the diaphragm or the phrenoesophageal ligament (or both) is not well understood. There is published confirmation of structural differences in both the diaphragmatic muscle and the phrenoesophageal tissues with data demonstrating cellular and metabolic defects in elastin and collagen as well as distortion of metalloproteinase activity [2–4]. That PEH is a disease of the diaphragm and supportive structures are further corroborated by documented, and commonly clinically encountered, familial inheritance patterns [5].
As is common with any hernia, PEH comprises three components: the myofascial defect, the hernia sac, and the hernia contents. It is very rare for the hiatal defect to be small in primary PEH. Typically, there is a large defect with atrophy of the crural pillars. In extreme cases the defect can extend nearly to the vena cava and/or create a common opening with the aortic hiatus due to extreme effacement of the posterior crural decussation. The combination of a large horizontal defect, thin atrophic tissues, and probably an intrinsic connective tissue deficiency explain the difficulty of achieving a durable repair in PEH. Common to groin hernias, as the muscle defect enlarges, the circumferential suspensory “ligament” of the GEJ undergoes fatty degeneration and enlargement as it forms the hernia sac. The hernia sac in PEH is a complex structure and includes both an anterior and posterior component. The anterior sac is composed of the mediastinal portion of the phrenoesophageal ligament, a fibro-fatty connective tissue layer, and the peritoneum of the abdominal cavity. The posterior sac is made of the same components but the peritoneal lining is the retroperitoneum of the lesser gastric sac. The lateral fusion of these two hernia sacs incorporates the neurovascular supply of the lesser and greater gastric curve (Fig. 12.3). The intrinsic laxity of the phrenoesophageal ligament and the other ligaments that hold the stomach in position (such as the gastrosplenic and gastrohepatic ligaments) result in mobility of the stomach, which, with the pressure differential between abdomen and chest, preferentially migrates into the mediastinum and thoracic spaces along with the degenerated ligament, forming an intrathoracic hernia sac. As the stomach herniates, the fundus may rotate around the long axis of the stomach toward the right creating the potential for an organoaxial volvulus (Fig. 12.4). Rotation around the short axis is called mesenteroaxial volvulous (Fig. 12.5) When very large, either of these rotations can result in the condition called “upside-down stomach”. The herniated stomach can form adhesions in an intrathoracic position leading to incarceration and can also compress the herniated blood supply against the crura or even torse, both resulting in strangulation—a true surgical emergency [6].
Fig. 12.3
The anatomy of the PEH is important to understand, especially the structure of the anterior and posterior hernia sack. The lateral fusion of these two hernia sacs incorporate the neurovascular supply of the lesser and greater gastric curve
Fig. 12.4
Organoaxial volvulus
Fig. 12.5
Mesenteroaxial volvulus
Indications for Repair
PEH are frequently asymptomatic with an annual incidence of acute symptoms ranging from 0.7 to 7 % of patients [7]. Due to the potential for catastrophic, life-threatening complications, and the perceived increased risk of emergency surgery, traditional teaching has advocated repair of all identified PEH [8, 9]. However, more recent studies suggest that not all PEH mandate repair and that asymptomatic PEH can be managed expectantly and, in the surgically unfit, even delayed indefinitely [10, 11]. Sivho et al. found that need for emergency surgery was only 1.16 % per year, with a lifetime risk of 18 % at the age of 65 years. The mortality rate resulting from emergency repair of PEH is also only 2 % (compared to the historic rate of nearly 50 %) [8, 10, 12]. When emergency repair is attempted, the morbidity and mortality rates of early repair (17 and 3.4 %, respectively) are better than late repair (30 and 4.6 %, respectively), late being defined as occurring 1 or more days after presentation [13].
The presenting symptoms of PEH that indicate surgery can vary widely. Chest pain and shortness of breath, attributed both to mass effect with pulmonary or atrial compression, is a common but nonspecific symptom and underlying cardiac disease must be ruled out. Persistent or frequent non-cardiac chest pain is worrisome for incarceration and/or compromised blood flow which may lead to ulceration, bleeding, perforation, or strangulation. Another relatively common presenting symptom is dysphagia and/or vomiting due to gastric outlet obstruction. Giant PEH is frequently associated with chronic anemia—probably related to mechanical (Cameron’s) ulcers. Lastly, patients may present with typical reflux symptoms of heartburn and regurgitation due to pre-existing GERD or to the development of GERD secondary to anatomic disruption of the antireflux barrier from the progressive migration of the GEJ into the chest [6].
Preoperative Evaluation
Upper Gastrointestinal Contrast Study
An upper gastrointestinal contrast study is a useful first test to evaluate patients presenting with symptoms of dysphagia or heartburn and the most important test in establishing the diagnosis when paraesophageal hernia is suggested on other studies, such as plain chest radiograph or computed tomography [14]. UGI studies are extremely valuable in delineating the anatomy of the hernia (size and type), ruling out gastric volvulus and obstruction, and for assessing for esophageal length and potential hernia reducibility (Fig. 12.6). UGI also can suggest the presence of an underlying motility disorder indicating further evaluation. Given a proper videoesophagram, functional outcomes following paraesophageal hernia repair can be predicted for those patients with esophageal dysmotility documented by manometry but who are able to clear a food bolus at contrast esophagography [15]. Lastly, the UGI study is commonly used to evaluate recurrence of symptoms following repair.
Fig. 12.6
Upper gastrointestinal contrast study demonstrating a giant paraesophageal hernia
Upper Endoscopy
Upper endoscopy should always be considered part of the extended physical exam of patients presenting with foregut problems. Its benefit in patients with known or suspected PEH is well recognized [16]. Examination will help identify the esophageal length, amount of herniated stomach, degree of gastric volvulus, and extent of venous engorgement [17] (Fig. 12.7). Furthermore, mucosal abnormalities can be identified, such as esophagitis, gastritis, erosions (Cameron’s Ulcer’s), Barrett’s changes, or neoplasms [18].
Fig. 12.7
Retroflex view of the hiatus on upper endoscopy showing a typical paraesophageal hernia
pH Testing
Abnormal esophageal acid exposure may be present in up to 70 % of those with type III PEH [19]. For those selectively performing fundoplication with paraesophageal hernia repairs, pH testing is therefore necessary. Otherwise, we do not routinely obtain preoperative pH testing for known PEH, as it generally does not change the subsequent management (i.e., a fundoplication will routinely be added to the repair in all cases) [17, 20].
Esophageal Manometry
Though it is not universally required by all esophageal surgeons during the workup of PEH, esophageal manometry can still provide useful information and should be strongly considered. High-resolution manometry can provide a very unique measurement or “map” of the hiatal hernia itself which can complement the sometimes vague information from endoscopy and X-ray studies. Presence of a large hiatal hernia does not exclude primary motility disorders like DES or even achalasia, and symptoms of dysphagia are as likely to be from dysmotility as they are from anatomic distortion. Identification of an underlying esophageal motility problem preoperatively can help guide patient expectations regarding potential persistent dysphagia despite hernia repair. Roman et al found that patients with large hiatal hernias overall had lower mean GEJ pressures, a lower distal contractile integral, slower contractile front velocity, and a shorter distal latency time [21].
Esophageal manometry in the paraesophageal hernia patient often poses unique challenges both with technically obtaining the study and with interpretation. The classic manometric finding suggestive of a hiatal hernia is the “double hump” pattern created by separation of the LES and diaphragmatic hiatus (Fig. 12.8a). However, not all manometries for PEH show a “double hump” either due to inability to pass the catheter out of the hernia and across the diaphragm or to a wide hiatus that it does not exert a measurable pressure reading on the catheter. It can be difficult to pass the catheter past the crural diaphragm in approximately half of the patients and therefore the presence of a large hiatal hernia may result in a technically imperfect study in as many as 57 % of cases [21, 22]. Evidence of GEJ outflow obstruction can also be seen in PEH due to the mass effect of the herniated stomach at the hiatus. This can lead to elevated integrated relaxation pressure (IRP) and intrabolus pressure (IBP) which may be misinterpreted as a poorly relaxing LES with simultaneous esophageal contractions (Fig. 12.8b).
Fig. 12.8
(a) High-resolution manometry showing the classic “double hump” pattern created by separation of the LES and diaphragmatic hiatus in hiatal hernias. (b) Evidence of gastroesophageal junction outflow obstruction in PEH. This topography could be misinterpreted as simultaneous esophageal contractions with impaired LES relaxation especially in the absence of a “double hump” or other knowledge of the presence of a PEH
Laparoscopic Operative Technique
Positioning
The patient is positioned in the supine position on a split-leg operating table with the arms outstretched and legs abducted. All pressure points are padded. The patient is secured to the table with leg and arm straps as steep reverse Trendelenburg position is used to facilitate hernia reduction and visualization of the upper abdominal cavity.
Access and Trocar Placement
After general endotracheal anesthesia is obtained, the abdomen is prepped and draped. Local anesthetic (0.25 % bupivacaine with epinephrine) is used prior to making incisions. Insufflation is obtained by the Veress needle technique in the left mid-abdomen, followed by a 10 mm dilating trocar. A 10 mm 45-degree laparoscope is inserted. The underlying intra-abdominal contents are inspected for injury and a brief survey of the surgical field is performed. The remaining trocars are placed under direct visualization with the laparoscope. In total, five ports are placed—a 10 mm one for the camera and the rest typically being 5 mm (Fig. 12.9). A liver retractor elevates the left lobe and is subsequently held by a table-mounted retractor holder allowing a more stable and less traumatic consistent exposure of the esophageal hiatus (Fig. 12.10).
Fig. 12.9
Position of the patient and the laparoscopic ports for PEH repair
Fig. 12.10
Anatomy of the hiatus prior to dissection and reduction of the paraesophageal hernia
Dissection
No attempt should be made to reduce the stomach (or other viscera) by direct traction as this is seldom successful and can easily cause traumatic injury as one is pulling directly against the pressure generated by the laparoscopic insufflator. The herniated stomach of a PEH is often fragile due to edema, relative devascularization, and chronic inflammation. A no touch technique will prevent grasper injuries. If the hiatal opening is packed tightly with omentum, an attempt can be made to gently reduce just the omentum but not the viscera. Dissection begins at the apex of the hiatus. The hernia sac is grasped anteriorly from within the mediastinum and everted. The hernia sac is grasped between two graspers and a small incision with an ultrasonic dissecting shear is made at the edge. This allows entry into the mediastinal space. Extra care and time should be taken during this part of the operation as identifying the correct plane is paramount to the rest of the dissection. This step should be bloodless—if not, the most likely problem is that the muscular diaphragm is being dissected and the surgeon should redirect the dissection appropriately (Fig. 12.11). Once the correct plane is identified, blunt dissection is used to sweep mediastinal tissues off the hernia sac and cautery or ultrasonic energy is used as needed to maintain a hemostatic field. It should be noted that there are several tissue planes in the mediastinum: peritoneum, retroperitoneum, mediastinal fascia, mediastinal pleura, and true pleura. If one is in the correct tissue plane—between the peritoneum/retroperitoneum and mediastinal fascial planes—it is relatively avascular and bleeding should be minimal. If one is having constant bleeding during the mediastinal dissection, it is an indication that one is too deep into the mediastinum.
Fig. 12.11
Mobilization is focused on hernia sack dissection and starts with careful dissection at the hiatal apex to enter into the correct avascular plane
Using gentle caudal traction on the edge of the hernia sac and blunt/ultrasonic mobilization of the mediastinal portion, as well as circumferential division of the phrenoesophageal ligament from the hiatus, the hernia sac is reduced out of the mediastinum. This dissection should proceed first toward the left crus as the tissue planes along the right crus are more complex—usually including the herniated pars flacida and possibly the left gastric artery pedicle. It needs to be remembered that a type III hernia typically includes herniation of both the anterior sack (peritoneal cavity) and a posterior sack (the retroperitoneum or lesser sack), with the fusion plane between the two corresponding to the lesser and greater gastric curves and containing the short gastric vessels and lesser curve vasculature and vagus nerves (Fig. 12.3). After mobilizing the left side of the hernia and clearing the left crus (hopefully far enough posterior that the base of the right crus is seen), attention can be transferred to the right side. We recommend dividing the phrenoesophageal ligament about 1 cm from the edge of the crura to avoid denuding the crura of its peritoneal fascia since it is under tension and will retract after division. Once the left side is mobilized, the laparoscopic insufflation starts working for you as the positive pressure is now directed into the mediastinum and not inside the hernia sack, making it easier to invert and reduce the right side of the hernia sack, with all of its herniated vascular and vagal contents, and restoring a more normal anatomical picture. With the right hernia sack inverted into the abdomen by the assistant, mobilization of the right crus can then proceed by dividing the pars flacida along the caudate lobe which exposes the phrenoesophageal ligament, which can be dissected by continuing its division from the hiatal apex to its fusion posterior with the left crus.
Reduction of the hernia sack into the abdominal cavity effectively brings the stomach and GEJ into the abdomen without ever applying direct traction on the organ. An extended, or type II, mediastinal dissection is still typically required to enable adequate intra-abdominal esophageal length. This dissection can be carried high into the mediastinum, even to the level of the carina, to completely mobilize the distal esophagus and maximize intra-abdominal esophageal length. In 2–5 % of PEH cases, this extended dissection will not achieve adequate tension-free esophageal length; in which case a Collis lengthening procedure should be performed (see Chap. 19). The anterior and posterior vagus nerves should be identified early and preserved during the mobilization portion of the procedure. At this point or later, the upper gastric fundus is mobilized by dividing the short gastric arteries using bipolar or ultrasonic energy, starting at the watershed area just cephalad to the last arcade of the gastroepiploic artery usually near the lower pole of the spleen.
In most cases, a portion of the mediastinal hernia sack should be resected after the GEJ is fully reduced. This is both to better expose the anatomy of the GEJ and also because the fatty degenerated phrenoesophageal ligament that comprises the sack would be trapped between the esophagus and subsequent wrap. To resect it, the assistant can put traction on the right side of the sack, in the direction of the right lower quadrant which puts the anterior vagus on stretch making it easier to see. The left side of the sack is placed on stretch toward the left lower quadrant and the sack is divided from the gastric lesser curve caudally along (to the left of) the anterior vagus. It can then be dissected off the anterior stomach just past the greater curve and removed. One should avoid trying to completely excise the hernia sack as doing so would risk injury to the vagus nerves and even left gastric artery and the right side of the sack is not a problem for the subsequent repair. Once the left side of the GEJ is cleared, the intra-abdominal esophageal length can be reassessed and further mediastinal dissection is performed as needed to achieve at least 2–3 cm of intra-abdominal esophagus (Fig. 12.12). Intraoperative endoscopy is a useful adjunct at this point, to identify the esophagogastric junction and ensure adequate intra-abdominal esophageal length.
