Hiatal hernia controversies--a review of pathophysiology and treatment options

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.     

Hiatal hernia controversies - a review of pathophysiology and treatment options

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 fundoplica-tion in dogs. Both oesophagopexy and Nissen fundoplication require further evaluation in small animals.     

Hiatal hernia in a shar-pei

A combined axial and paraoesophageal hiatal hernia complicated by splenic involvement was diagnosed in a two-year-old Chinese shar-pei. A circumcostal gastropexy was performed following reduction of the hernia and fundoplication of the cardia The dog recovered well and is asymptomatic six months postoperatively. The literature concerning hiatal hernia in the dog is reviewed and the various surgical techniques described for its management are discussed.     

Gastric dilatation and volvulus in a brachycephalic dog with hiatal hernia

A brachycephalic dog was presented with an acute onset of retching and abdominal discomfort. The dog had a chronic history of stertor and exercise intolerance suggestive of brachycephalic airway obstructive syndrome. Radiographs were consistent with a Type II hiatal hernia. The dog was referred and within hours of admission became acutely painful and developed tympanic abdominal distension. A right lateral abdominal radiograph confirmed gastric dilatation and volvulus with herniation of the pylorus through the hiatus. An emergency exploratory coeliotomy was performed, during which the stomach was derotated, and an incisional gastropexy, herniorrhaphy and splenectomy were performed. A staphylectomy was performed immediately following the exploratory coeliotomy. The dog recovered uneventfully. Gastric dilatation and volvulus is a potentially life‐threatening complication that can occur in dogs with Type II hiatal hernia and should be considered a surgical emergency .     

Hiatal hernia in the dog: a clinical report of four Chinese shar peis

Four Chinese shar pei littermate puppies were presented for vomiting, regurgitation, hypersalivation, and poor growth. Diagnosis of hiatal hernia was made for each of the four dogs based on survey radiographs and barium esophagram studies. All dogs initially underwent medical therapy, to which only one dog responded. All dogs underwent surgical treatment, which included manual hernia reduction followed by phrenoplasty, esophagopexy, and left incisional gastropexy, 5 to 40 days following initiation of medical therapy. The three surgical techniques described eliminated the need to enter the pleural cavity and offered excellent long-term results with no recurrence of clinical signs following surgery.     

Hiatal hernia in a harbor seal (Phoca vitulina) pup

A 2-wk-old stranded harbor seal (Phoca vitulina) rescued by Mystic Aquarium showed signs of the presence of a hiatal hernia during rehabilitation. Contrast radiographs of esophagus and stomach revealed an intrathoracic radiodensity that contains filling defects typical of stomach, consistent with gastric rugal folds. Mural thickening was observed at the level of the cardia consistent with a diagnosis of a hiatal hernia. Although clinical improvement was noted with medical therapy and tube feeding, surgical correction of the hiatal hernia was considered necessary for full resolution. However, owing to the animal's low body weight, the corrective hernia surgery was postponed until the body condition improved. The seal needed to be surgically treated for a corneal ulcer, and while anesthetized with isoflurane, the seal became dyspneic and developed cardiac arrhythmias; ultimately cardiac arrest ensued. Resuscitation was unsuccessfully attempted and the seal was euthanized. Necropsy confirmed the radiographic diagnosis and further characterized a paraesophageal hiatal hernia.     

Paraoesophageal hiatal hernia and megaoesophagus in a three-week-old Alaskan malamute

Paraoesophageal hiatal hernia was diagnosed in a three-week-old Alaskan malamute. Reduction of the hernia was followed by an oesophagopexy and a bilateral gastropexy. During the early postoperative period, the puppy continued to have signs that were thought to be related to a concurrent megaoesophagus. At nine months of age the dog had gained weight and was well except for occasional episodes of regurgitation. These episodes responded well to medical therapy, and at the time of writing the dog had not required further treatment.     

TYPE-4 ESOPHAGEAL HIATAL HERNIA IN A CHINESE SHAR-PEI DOG

Thoracic radiography of a 3-month-old, female Chinese Shar-pei revealed an esophageal hiatal hernia with stomach, liver, and small intestine displaced into the thorax. Three days after the surgical correction, the dog developed ileal intussusception and was reoperated. Recovery was uncomplicated and the dog was asymptomatic 16 months after surgery.     

Retained surgical swabs in 13 dogs

To report the signalment, history, clinical signs, diagnostic and surgical findings and outcome in dogs and cats with retained swabs, medical records of dogs and cats that were referred to four referral centres were reviewed. Cases in which a retained surgical swab was identified during surgery at the referral hospital were selected for further study. The signalment, history, clinical signs, diagnostic and surgical findings and outcome in these cases were reviewed. Thirteen dogs with retained surgical swabs were included in the study. Bodyweight ranged from 9 to 45 kg. The initial surgery was a 'non-routine' abdominal procedure in seven dogs, ovariohysterectomy in five dogs and perineal hernia repair in one dog. Time from initial surgery to presentation at the referral centre ranged from four days to seven years. Treatment involved major surgery in eight of the 13 dogs. Outcome was excellent in 12 of 13 cases, one dog was euthanased.     

Abnormalities of the Thoracic Bellows: Stress Fractures of the Ribs and Hiatal Hernia

The thoracic bellows mechanism consists of the rib cage and the diaphragm. The purpose of this study was to determine if nontraumatically acquired lesions of the bellows were secondary to underlying disease. Abnormalities of the bellows, specifically stress fractures of the ribs and hiatal hernia, were found in 21 dogs and cats with underlying cardiopulmonary disease, neuromuscular disease, or metabolic disease. A case-control study of Bulldogs demonstrated that hiatal hernia was associated with the more severe manifestations of brachycephalic syndrome. Stress fractures occurred mostly in females and in cats, and involved multiple ribs. Fractures were usually related to severe respiratory effort, but also occurred in association with metabolic disease. Hiatal hernia was also associated with severe respiratory effort, but may be exacerbated if a neuromuscular disorder affecting the diaphragm is present. Abnormalities of the thoracic bellows, such as rib stress fractures and hiatal hernia, may be signs of underlying disease, rather than being primary causes of disease.     

Hiatal herniation as a complication of chronic diaphragmatic herniation

Three of four cases of chronic diaphragmatic herniation seen over a period of 12 months developed hiatal herniation within five to eight days of corrective surgery for the diaphragmatic herniation. None of the dogs had shown any prior signs referrable to hiatal herniation. The features that developed subsequent to diaphragmatic herniorrhaphy in all cases were dyspnoea, increased intra-abdominal pressure due to decreased abdominal domain and laxity of the oesophageal hiatus as judged subjectively at the time of surgery for hiatal herniation correction. These conditions may be significant underlying factors for the development of hiatal herniation not preceded by diaphragmatic herniation in the dog. Those associated factors accepted as important in humans, including reduced lower oesophageal sphincter tone and gastroesophageal reflux, may not be of similar importance in small animals.     

Congenital oesophageal hiatal hernia in a pug

Congenital sliding, oesophageal or type I hiatal hernia was diagnosed in a five-month-old pug puppy presented for evaluation of dyspnoea post feeding. The diagnosis was confirmed using plain film radiography. Surgical reduction of the hernia followed by plication of the oesophageal hiatus, oesophagopexy and left flank gastropexy permitted restoration of normal function. At 12 months of age, the dog was asymptomatic. This article describes the diagnosis and treatment of a congenital type 1 oesophageal hiatal herniation with unusual clinical presentation.     

Chronic diaphragmatic hernia in 34 dogs and 16 cats

Medical records of 34 dogs and 16 cats undergoing surgical repair of diaphragmatic hernia of >2 weeks' duration were reviewed, and long-term follow-up information was obtained. The most common clinical signs were dyspnea and vomiting; however, many of the animals were presented for nonspecific signs such as anorexia, lethargy, and weight loss. Thoracic radiographs revealed evidence of diaphragmatic hernia in only 66% of the animals, and additional imaging tests were often needed to confirm the diagnosis. Thirty-six hernias were repaired through a midline laparotomy; 14 required a median sternotomy combined with a laparotomy. In 14 animals, division of mature adhesions of the lungs or diaphragm to the herniated organs was necessary to permit reduction of the hernia. Fourteen animals required resection of portions of the lungs, liver, or intestine. All hernias were sutured primarily without the use of tissue flaps or mesh implants. Twenty-one of the animals developed transient complications in the postoperative period; the most common of these was pneumothorax. The mortality rate was 14%. Thirty-four (79%) of the animals that were discharged from the hospital had complete resolution of clinical signs, and none developed evidence of recurrent diaphragmatic hernia during the follow-up period. Nine were lost to follow-up.     

Clinical, echocardiographic, and radiographic findings of peritoneopericardial diaphragmatic hernia in two dogs and a cat

Peritoneopericardial diaphragmatic hernia was diagnosed in 2 dogs and a cat. One dog was referred because of clinical signs of cardiac tamponade and acute decompensation from liver entrapment within the hernia. Surgical correction of the hernia alleviated clinical signs in all 3 animals. Echocardiography was used in combination with radiography to provide a rapid and accurate diagnosis.     

Congenital Esophageal Hiatal Hernia in the Chinese Shar-Pei Dog

Esophageal hiatal hernia was diagnosed in 11 young Chinese Shar-Pei dogs between October 1985 and July 1991. The dogs ranged in age from 2 to 11 months and included 3 females and 8 males. The most common clinical signs were regurgitation, vomiting, and hypersalivation. Physical examination was normal in 6 dogs; abnormal physical examination findings in the other 5 dogs included fever, dehydration, hypersalivation, and pulmonary wheezes and crackles. Laboratory evaluation was significant only for neutrophilia in 5 dogs. A diagnosis of hiatal hernia was made on the basis of survey thoracic radio-graphic and/or barium esophagram findings of displacement of the esophagogastric junction and stomach into the thoracic cavity; the diagnosis was confirmed by surgery in 9 dogs and at necropsy in 2 dogs. Megaesophagus (n = 7), gastroesophageal reflux (n = 4), and esophageal hypomotility (n = 1) were additional findings in some dogs. Aspiration pneumonia was diagnosed in 7 of the dogs. Medical therapies formulated for the therapy of presumed reflux esophagitis generally failed to resolve the clinical signs associated with the hiatal hernia. Hiatal herniae were surgically repaired in 9 of the Shar-Peis by various combinations of diaphragmatic crural apposition, fixation of the esophagus to the diaphragmatic crus (esophagopexy), and left fundic tube gastropexy. Eight of the animals survived surgery, six of which have been asymptomatic since surgery (19 to 36 months). The megaesophagus, esophageal hypomotility, and bronchopneumonia resolved in all of these dogs. (Journal of Veterinary Internal Medicine 1993; 7:210–215. Copyright © 1993 by the American College of Veterinary Internal Medicine.)     

Paraesophageal hiatal hernia and pyloric obstruction in a dog

Paraesophageal hiatal herniation and pyloric obstruction were diagnosed in a pup with a history of vomiting. Findings of contrast radiography included esophageal reflux, delayed gastric emptying time, and paraesophageal herniation. Exploratory celiotomy revealed increased firmness of the pylorus and a primary defect in the esophageal hiatus, which allowed gastric herniation. Nissen fundoplication was performed following reconstruction of the esophageal hiatus, and pyloroplasty was performed to relieve the gastric outlet obstruction. Pyloric biopsy findings were consistent with a diagnosis of chronic gastritis. Recovery from surgery was initially unremarkable; however, the dog died suddenly 3 weeks after surgery. Necropsy revealed a large diaphragmatic hernia adjacent to the esophageal hiatus; the hernia had resulted in incarceration of the abdominal organs. The hiatal hernia reconstruction remained intact and was not the cause of the diaphragmatic disruption.     

Chronic primary splenic torsion with peritoneal adhesions in a dog: case report and literature review

Primary splenic torsion in dogs is uncommon and can occur in acute or chronic form. The chronic form is difficult to diagnose because the clinical signs are vague and sometimes intermittent. A dog with a history of diaphragmatic hernia repair two years previously presented with chronic, vague clinical signs and an abdominal mass. The mass was revealed to be spleen on ultrasonography. On exploratory laparotomy, the dog was found to have a splenic torsion of approximately 180 degrees with mature, fibrous adhesions retaining the spleen in a torsed position. A splenectomy was performed, and the dog recovered uneventfully with complete resolution of prior clinical signs. Prognosis for dogs with splenic torsion is good, although complications are relatively common.     

Congenital narrowing of the intrapharyngeal opening in a dog with concurrent oesophageal hiatal hernia

A one-year-old, male, smooth-haired standard dachshund was presented with a history of chronic hypersalivation, dysphagia, puffing of the cheeks on expiration, and inspiratory stridor. Oral examination revealed a moderately thickened tongue radix and that the normal intrapharyngeal opening was obliterated. A 7 mm long, midline palatal slit was the only communication between the naso- and oropharynx. The soft palate was fused to the caudal pharyngeal wall. A concurrent hiatal hernia was diagnosed on thoracic radiographs. The soft palate abnormality was surgically corrected and the hiatal hernia was managed medically. On follow-up evaluations, the clinical signs had markedly improved, and the hiatal hernia was no longer visible on survey thoracic radiographs.     

Subtotal colectomy for treatment of acquired megacolon in the dog and cat

The case records of 4 cats and 1 dog with megacolon and constipation were reviewed to study the history, clinical signs, pathologic changes, and longterm results of surgical treatment. The 4 cats had idiopathic megacolon. The dog had megacolon secondary to dietary indiscretion. All animals had radiographic evidence of a large colon, which was confirmed by exploratory coeliotomy. Two of the cats and the dog had an intraoperative finding of megacecum as well. Subtotal colectomy was performed in all cases, with the ileocolic valve being removed in 3 of these cases. End-to-side anastomosis was used to restore the integrity of the bowel. All animals were treated successfully with this surgical technique, as judged by clinical response and owner satisfaction. Histologically, there were no consistent lesions to explain the cause of this disease in the cats.     

Marked pleural effusion causing right atrial collapse simulating cardiac tamponade in a dog

A 16-month-old, female German shepherd dog was presented with severe bicavitary effusions. A diaphragmatic hernia was diagnosed by thoracic radiography. An echocardiogram performed prior to surgical repair of the hernia revealed signs of cardiac tamponade, with right atrial collapse, in the absence of pericardial effusion. Right atrial collapse was presumed to be secondary to severe pleural effusion. At surgery, no pericardial disease was identified. Surgical correction of the diaphragmatic hernia resulted in resolution of the pleural and peritoneal effusions. Follow-up echocardiography demonstrated resolution of the signs of cardiac tamponade.