Hiatal hernia controversies ‐ a review of pathophysiology and treatment options

Abstract

Objective To provide a detailed discussion of the aetiology and pathophysiology of hiatal hernia in both humans and small animals, and review current medical and surgical treatments. Design Review article.Summary Hiatal hernia is not completely understood in humans or animals. It has a complex multifactorial aetiology and pathophysiology. A primary disturbance of the lower oesophageal sphincter has not been shown in humans or animals. Knowledge of pathophysiology is necessary to institute appropriate treatment.Medical and/or surgical therapy is not indicated in asymptomatic cases. Medical treatment should be used for up to 1 month in stable cases of sliding hiatal hernia. Paraoesophageal hiatal hernias and any large sliding hiatal hernia should be considered for prompt surgical treatment. Surgical techniques used depend on the type of hiatal hernia present.Surgical treatment of hiatal hernia cases should be performed by experienced surgeons, and must include hiatal closure and gastropexy. The Nissen fundoplication procedure has been discontinued in the veterinary field due to poor success rates, coupled with the published view that there is a marked difference in pathophysiology between humans and dogs. Reported complications associated with the original Nissen fundoplication technique are identical in the human and veterinary literature. There have been no complications reported with use of the modified or 'floppy' Nissen fundoplication in dogs. Both oesophagopexy and Nissen fundoplication require further evaluation in small animals. Aust Vet J 2002;80:48-53 HH Liatal hernia LOS (intrinsic) lower oesophageal sphincter

Gastric dilatation and volvulus in a brachycephalic dog with hiatal hernia

“…None of the authors of this article has a financial or personal relationship with other people or organisations that could inappropriately influence or bias the content of the paper. the gastric fundus in Type II HH in humans has been reported to increase traction on the greater curvature of the stomach and increase the laxity of the gastrosplenic ligament resulting in gastric volvulus (Krähenbuhl et al 1998, Sivacolundhu et al 2002. It is believed that this mechanism could explain the development of GDV in this dog that would have otherwise been considered at low risk for GDV.…”

“…It was hypothesised that the dog in this case report had a preexisting Type II HH and subsequently developed GDV. Although Boston terriers are not reported to be predisposed to HH, chronic negative intrathoracic and intraoesophageal pressure observed in brachycephalic dogs with upper airway obstruction has been suggested to contribute to HH by pulling the stomach into the thorax (Sivacolundhu et al 2002, Poncet et al 2005, 2006. Given that this dog had clinical signs and anatomical abnormalities consistent with brachycephalic upper airway obstruction it is suspected that this conformational disorder may have predisposed him to Type II HH.…”

“…Hiatal hernia (HH) is the protrusion of abdominal contents into the thoracic cavity through the oesophageal hiatus (Ellison et al 1987, Prymak et al 1989, Lorinson & Bright 1998. Four types of HH are described (Ellison et al 1987, Prymak et al 1989, Lorinson & Bright 1998, Sivacolundhu et al 2002. Type I, or sliding HH, is the most commonly diagnosed form in dogs and cats and consists of cranial displacement of the abdominal oesophagus, oesophagogastric junction and often a portion of the stomach.…”

“…HH may be congenital or acquired (traumatic) in origin. It may be due to an abnormally wide hiatus that decreases the resistance of entry of the oesophagogastric junction or cardia into the thorax or an increasing gradient between intra-abdominal and intrathoracic pressure leading to the displacement of abdominal contents into the hiatus (Sivacolundhu et al 2002). In Type II herniation in humans the HH enlarges with time (Ellis 1980).…”

2002: Hiatal hernia in a puppy

“…4 Pathophysiology and treatment options for hiatal hernia have been reviewed recently in this journal. 5 Briefly, a defect of the diaphragmatic hiatus allows the abdominal part of the esophagus, the esophagogastric junction, and part of the stomach to migrate through the esophageal hiatus into the thoracic cavity. This results in compromised function of the lower oesophageal 'high pressure zone', leading to oesophageal dysmotility.…”