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Gastric Dilatation and the Gastric Torsion Complex
Gastric Dilatation and the Gastric Torsion Complex
William D. DeHoff, D.V.M., M.S.* Richard W. Greene, D.V.M.**
Gastric torsion is always associated with and is probably preceded by gastric dilatation, but gastric dilatation can and does occur as a separate entity.
GASTRIC DILATATION Gastric dilatation occurs in all breeds at any age and is often selflimiting, owing to the animal's ability to empty its stomach either through vomiting or passage of contents into the duodenum. Among the common etiologic factors of gastric dilatation are general anesthesia, abdominal surgery, traumatic injury, spinal injury, overeating, pica, ingestion of foreign materials, parturition, vomiting, abnormal swallowing of air, and malignant tumors. 7 These causes of gastric distention lead to reflex inhibition of the normal gastric motor and secretory functions, either by direct distention and irritation of the gastric wall or by their action on the sympathetic pathways. The resulting situation may be transient, as when puppies are overfed, 7 but if the distention is prolonged, medical and even surgical intervention may be necessary. The signs of gastric dilatation are a distended, painful anterior abdomen; restlessness; nonproductive vomiting; and excessive salivation. The severity of signs depends on the severity of the dilatation. The diagnosis is based on the history, which may indicate a chronic problem; the clinical signs, most important of which is abdominal dis ten*Head of Surgery, The Animal Medical Center, New York, New York 10021; Diplomate, American College of Veterinary Surgeons. **Staff Surgeon, Section of General Surgery, The Animal Medical Center, New York. New York 10021. The authors thank Mrs. Mary B. Brown, Miss Deena Wolfson, and Mrs. Nancy Sturge for their assistance in the preparation of the manuscript. Veterinary Clinics of North America- Vol. 2, No. I Qanuary, 1972).
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GREENE
tion; radiographic findings, if examination is possible without stressing the animal; and relief of the distention by passage of a stomach tube.
TREATMENT
The first objective in treating gastric dilatation is to correct the distention. The etiology should then be determined. When dilatation is severe, attempts should be made to relieve the distention promptly and with as little stress as possible to avoid complications. Electrolyte imbalance, respiratory embarrassment, vascular hypotension, and gastric mucosal devitalization due to prolonged dilatation are among the secondary problems associated with gastric dilatation. Simple Gastric Dilatation A pliable vinyl plastic stomach tube of moderate firmness usually can be passed using an oral speculum. If difficulty is encountered while passing the tube, the animal should be anesthetized and a straight metal gastric tube passed gently into the stomach, being careful not to traumatize the esophagus. After the distention has been relieved, the metal tube is removed and is replaced by a vinyl tube with a relatively large bore. Because the vinyl tube conforms to the shape of the esophagus, fewer vital structures such as the heart are displaced. If anesthesia is necessary, the animal should be placed on an inclined table with its head down, followed by insertion of a cuffed endotracheal tube to prevent inhalation pneumonia. Positive pressure ventilation should be employed, and intravenous fluid therapy with lactated Ringer's solution and sodium bicarbonate should be instituted. If the dilatation has been associated with the ingestion of excessive food or foreign material, gastric lavage with warm saline should be repeated until all such material is removed. If gastric dilatation occurs repeatedly, a pharyngostomy should be performed and the flexible tubing inserted into the stomach via the pharyngostomy. This tube enables release of additional gases and fluids that might accumulate. The technique for pharyngostomy is quite simple. 3 The animal is placed in lateral recumbency under general anesthesia; in some cases, sedation and local anesthesia may suffice. After surgical preparation ofthe area just posterior to the angle of the mandible, the mouth is held open with the aid of an oral speculum, and an index finger is inserted into the retropharyngeal pouch (piriform fossa), located in the pharynx near the base of the tongue, posterior to the hyoid apparatus (Fig. 1). The index finger is then replaced with a large, curved hemostat, causing the skin to bulge outward. A small incision is
143
GASTRIC DILATATION AND THE GASTRIC TORSION COMPLEX
Stylohyoid Epiglottis
Thyrohyoid -",..::>,...----"'
Thyroid cartilage Cricoid cartilage Trach9a
Figure l. Prior to making the pharyngostomy incision, th e index finger is inserted into the retropharyngeal pouch (piriform fossa) posterior to the hyoid apparatus. (From Pharyngostomy .for iHaintenaru;e of the Anorectic Animal, by R. H . Bohning·, .Jr., W. D. DeHoff, A. McElhinne y, and P. C. Hofstra., J.A.V.M.A., 156, .'>:611 - l!'i , 1970, used by permission.)
made through the skin and underlying fascia. The hemostat is then forced out through the skin incision from inside the pharynx. The tubing, which is precut to the proper length according to the distance from the angle of the jaw to the last rib, is pulled into the pharynx with the forceps and passed down the esophagus into the stomach. The tubing is then secured to the skin with a pursestring suture. The pharyngostomy tube is useful for administering food and water, as well as for relieving accumulation of gas within the stomach. The animal can also eat and drink with the tube in place without discomfort (Fig. 2). The tube is removed by cutting the pursestring suture and gently drawing the tube out. The wound heals without sutures in seven days. As a general rule, the tube is left in place until the animal has been asymptomatic for 24 to 48 hours. All animals treated for gastric dilatation, with or without a pharyngostomy tube, are fed light, brothy meals three to five times a d ay for two to three d ays before a more normal diet is reestablished. When normal feeding is resumed, it is recommended that relatively soft foods be given and that the animal be fed more than once a day.
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Figure 2.
w. GREENE
l'haryngostomy tube in p lace.
Gastric Dilatation with Complications
Whe n complications ar e associated with gastric dilatation , further diagnostic studies are indicated. The history should be reviewed as to previous occurrences , die t , and hereditar y background. T h e radiographic examination is important in this phase of follow-up care. The evaluation of gastric a nd pyloric function can be d ifficult because of th e wide range of acceptable gastric emptying times, motility, size, a nd shape. It is important to h ave a good standard r adiographic technique for gastr ic studies to reduce th e numbe r of variables. Diagnosis can be b ased more easily on radiographic eviden ce of foreign bodies or malign ant tumors tha n on delayed gastric emptying times. If the gastric emptying time is d elayed or a ppears abnor mal in any way, a nd if there are no other diagnostic clues, we recomme nd p yloroplasty or pyloric bypass on an elective basis. A pyloroplasty ensures a wide opening for passage of gastric conte nts and forms an area that will not go into spasm . A number of different p yloroplasties and pyloric bypass procedures are available, ranging from simple m yoto mies to more involved an astomotic techniques. Gene rally, the more sophisticated surgery results in a wider openin g into the small bowel. T h e Fredet- Ramstedt pyloroplasty is a m yotomy in which the incision is carried down to but not throu gh the mucosa, so that the mucosa can bulge ou tward. A lon gitudin al incision exte nding 1 to 2 em . on either side of the pylorus is made on the ventral surface of the p ylorus u sing a No. 15 Bard-Parker scalpel blade. It is usu ally easie r to carry the
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Figure 3. The Fredet-Ramstedt pYloroplastY. Th e circular muscle ar ound the p ylorus is simply freed, allowing the m ucosa to bu lge out\\"ard .
incision down to the mucosa OYer the stomach and then extend it onto the duodenum. All restricting bands of circular muscle should be cut. The incised walls are then undermined a nd dissected away from the mucosa until about 50 per cen t of the circum ference is freed (Fig. 3). Another p yloroplastY . the Heineke- l\Iikulicz procedure, involves a lo n gitudinal incision similar to that for the Fredet- Ramstedt p ylon)plasty, but the incision pe netrates the mucosa. The longitudinal incision is sutured in a simple interrupted pattern h orizontally, resulting in a shortening and widening of the pyloric canal. This technique is useful if the mucosa has been d amaged during a Fredet-Ramstedt myotomy. A gastroduodenostom y is incorporated in the Finney p yloroplasty. This procedure yields a much wider opening between the stomach and the duodenum. T he incision is made in the sam e location as th e previously described pyloroplasty, but it is extended further down the antemesenteric border of the duodenum and aroun d on the stom ach near the gr eater curvature . The incision is then closed by first suturing together the farthest edges of the duodenum and sto mach and then suturing the near edges of the duodenum and stomach, form in g a large opening between them . T he fourth technique employed to facilitate gastric emptying is a gastroduod e nostomy. T his technique establish es a separate gastroduodenal anastomosis, leaving the pylorus intact. T he latter two techniques, the Finney pyloroplasty and the gastroduodenostomy, are the techniques preferred in dogs of large breeds which have recurrent episodes of gastric dila tation. Eithe r of these tech -
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WILLIAM D. DEHOFF, RICHARD
w.
GREENE
mques can be performed on an elective basis in a period when the animal is in good health and is able to withstand a more definitive procedure.
DIFFERENTIAL DIAGNOSIS
The differential diagnosis of a gastric dilatation is extremely important, since gastric torsion and intestinal volvulus are more life-threatening conditions than gastric dilatation. The clinical signs and history of all three conditions are similar, and the three conditions occur in all breeds and age groups. Signs which suggest intestinal volvulus rather than gastric dilatation and torsion are productive vomiting; lack of excessive salivation; uniform abdominal distention, rather than only the anterior portion; and easy passage of a stomach tube without relief of abdominal distention. The clinical signs of intestinal volvulus are less dramatic than those of gastric dilatation and torsion. Abdominal distention is less severe, and the clinical course of the condition is more protracted. Radiographically, intestinal volvulus is readily differentiated from dilatation or torsion of the stomach by the presence of large, air-filled loops of bowel throughout the abdomen and by the absence of gas in the stomach. In contrast, a large, dilated, balloon-like mass is seen in the anterior abdomen in gastric dilatation and torsion (Fig. 4).
THE GASTRIC TORSION COMPLEX Although simple gastric dilatation and intestinal volvulus are serious medical-surgical problems, definitive diagnosis and treatment are possible, and the prognosis is relatively good. The gastric torsion complex, on the other hand, has a more guarded prognosis because of the complications associated with the disease, such as severe shock; because a major surgical procedure must be undertaken to treat the condition; and because recurrence is common. It is generally agreed that gastric distention precedes gastric torsion.5 However, the etiology of gastric torsion has been widely debated. Such diverse factors as stretched gastric ligaments, calcium-phosphorus imbalances, pendulous, food-filled stomachs, distended spleens, anatomic predispositions, excessive postprandial exercise, and inherited defects and weakness have all been proposed.L 2 • 4 • 5· 6 There seems to be no sex predilection in animals affected. The condition does show certain patterns that seem significant. It most frequently affects dogs of the large, deep-chested breeds, such as the Great Dane, Standard Poodle, Boxer, Irish Setter, Weimaraner, English Sheepdog, Irish Wolfhound, Saint Bernard, and Bloodhound.
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Figure 4. Lateral abdominal radiogr aph of a dog with gastric torsion. The stomach is gas-filled, and the anterior abdomen is distended.
Animals affected usually h ave been fed a large m eal of bulky consistency two to six hours before presentation. T hey are often fe d and watered once a d ay, and then are exer cised shortly th er eafter. T here is often a history of periodic gastritis , and rela ted individuals m ay have had the same problem. Dogs with gastric torsions a re usually presented to our hospital as emergencies between 10:00 P.M. and 7:00 A.M. owing to the animals' feeding h abits and exercise schedules. T he clinical signs are similar to those of gastric d ilatation. Castric torsion should be regarded as an emergency, and the prognosis should be guarded.
TREATMENT There is no consensus r egardin g a specific treatme nt for gastric torsion. Several m ethods are available, d e pending on th e severity of the case. Over 60 cases of gastric torsion h ave been treated at T h e Animal Medical Cente r in the last five years. Based on this experience and o n the work of oth ers, we have arrived at a relatively consistent approach to its treatment. A few points regarding the gastric torsion complex should be e mphasized. Immediate diagnosis and treatment are critical. The earlier the condition is diagnosed and treated , the better the prognosis. T he
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dilatation associated with prolonged gastric torsion can lead to necrosis and even rupture of the stomach wall. The prognosis is understandably poor in this instance. The most serious preoperative complications associated with the condition include shock, electrolyte imbalance, and cardiorespiratory embarrassment. As the gastric distention increases, the portal vein and caudal vena cava become partially occluded. The venous return from the spleen is also slowed, causing the organ to become engorged (Fig. 5). These circulatory complications lead to h ypotension because the volume of blood returning to the heart is reduced. The anterior displacement of the enlarged stomach also interferes with the capacity of the diaphragm to expand with ventilation. Because of these difficulties, the animal is often presented in some degree of shock, showing signs of increased heart rate, delayed capillary filling, and d yspnea. Total collapse is often imminent; therefore, long delays in diagnosis or treatment must be avoided. A number of different programs of treatment have been recommended, but they are all geared initially to restoring the deteriorating cardiovascular function, decompressing the gastric distention, and realigning the displaced organ stru ctures. As previously described, the vinyl stomach tube is passed gently. If the tube cannot be passed into the stomach, the animal should be anesthetized, positive pressure ventilation utilizing a cuffed endotracheal tube instituted, and a metal stomach tube passed. If this tube cannot be passed, the diagnosis of gastric torsion complex is confirmed. We recommend immediate abdominal surgery, although its value has been ques-
Figure 5. The spleen in this dog with gastric LOrsion was markedly e ngorged .
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tioned by Funkquist, et a!. , who recommend a more conservative approach.4 If the stomach tube does enter the stomach, the case is treated as a dilatation as previously discussed. If gas continues to accumulate within the stomach, even though the tube entered the stomach, o r if the animal's general discomfort and state of shock do not impr ove, an exploratory laparotomy is also recommended. In this instance, it is possible that the stomach and spleen are twisted, even though the gaseous distention has been relieved. Before the abdomen is explored, the cardiopulmonary system should be monitored and supportive therapy in stituted if necessary. An endotrach eal tube is passed and inflated to prevent inhalation pneumonia and to permit assisted ventilation. A jugular catheter is inserted to enable administration of fiuids and monitorin g of central venous pressure. Cortisone and antibiotics are administe r ed via this route when shock is a proble m. Cardiac function should be monitored continuously while the animal is being prepared for surgery. The animal's already compromised cardiopulmonary status is further stressed when the animal is anesthetized and placed on its back. In this position, further pressure is applied to the diaphragm, caudal vena cava, and portal veins. Attention to the positioning is important throughout the surgical procedure . A ventral midline incision is employed, extending from the xyphoid cartilage to well below the umbilicus to permit ease of manipulation of the dilated stomach and spleen (Fig. 6). The stomach usually can be repositioned by rotating it counterclockwise, since the torsion is usually
Figure 6. In dogs with gastric torsion, a large incision is necessary to reposition the enlarged stomach and engorged spleen. Note the use of self-retaining Balfour abdominal retractors in the anterior p art of the incision.
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GREENE
clockwise for 90° to 360°, with the pylorus ventral to the stomach. 6 The repositioning can be aided by passing a large stomach tube and palpating the direction of the torsion of the distal esophagus and cardiac portion of the stomach. If this is impossible, gastric paracentesis can be performed, with the needle connected to rubber tubing so that the contents can be expelled directly into a container, thus preventing contamination of the abdomen. When the dilatation has been reduced, the stomach can be repositioned. Ideally, paracentesis should be avoided. After the stomach and spleen have been repositioned, a soft, pliable tube is guided from the mouth into the stomach, and gastric lavage with saline solution is repeated until all debris has been removed. The animal's general condition should be improving by this time. If large particles in the stomach cannot be washed out, a gastrotomy should be performed. To accomplish this, the stomach is packed off with warm towels moistened with saline, and an incision is made on its ventral surface midway between the omental borders. The wound can be held open with Allis tissue forceps or with retention sutures placed to hold the incision open for visualization and manipulation of the stomach. After all material has been removed from the stomach, and after the stomach wall has been inspected, the gastrotomy is closed with 00 chromic catgut in a two-layered, inverting continuous suture pattern, with the first layer of sutures penetrating the mucosa. The stomach should be examined for areas of necrosis. Because of its excellent blood supply, color should return quickly if the tissue is viable. If areas of the stomach wall are avascular or necrotic, the prognosis is grave. All necrotic portions must be removed (Fig. 7). Fortunately, this is an uncommon complication. It is sometimes necessary to perform a splenectomy to aid repositioning of the stomach but we do not recommend the procedure as a general rule. The spleen and its vascular supply should be examined for damage, and a partial or total splenectomy considered if indicated. The spleen may play some role in the production of gastric torsion, although we have seen the condition in animals which have had splenectomies previously. The next measure is pyloroplasty, since abnormal pyloric function is believed to be part of the etiology,L 4 • 5 and we perform pyloroplasty in all cases. Because the animal with gastric torsion has experienced a major insult, the procedure of choice is one that can be done quickly without further compromising the over-all success of the correction. The Fredet-Ramstedt or Heineke-Mikulicz procedure is usually elected, and the Fredet-Ramstedt pyloroplasty can be accomplished in less than five minutes. The pyloric musculature in many of these animals, especially those over five to six years of age or those in which gastritis has occurred repeatedly, often has some type of abnormality. A pyloroplasty will prevent spasm of the pylorus, whatever the cause, and promote more rapid gastric emptying.
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Figure 7. Gross specimen of a stomach that was resected after prolonged dilatatio n associated with gastric torsion. Much of the mucosal surface is necrotic.
The next consideration is a gastropexy; in theory, if the stomach or those structures that are able to twist can be fixed in normal positions, torsion cannot recur. This technique has not been successful in our hands to date. Dogs reoperated following gastropexy, including those with recurrent gastric torsions, have not been found to have any perman ent gastric adhesions. Plication of the lesser omentum has been suggested, as has a gastrostomy to prevent accumulation of gas postoperatively;2 when the gastrotomy is closed over, a solid, stabilizing gastropexy should result. We believe the theory of gastropexy h as great merit, but to date we have not achieved the permanent fixation desired without undertaking an involved procedure. If the stom ach h as been severely dilated and traumatized (Fig. 8) where further accumulation of gas is anticipated postoperatively, which would compromise the stomach's viability, we use a pharyngostomy tube until normal feeding can be resumed. If the pylorus or stomach has been opened, abdominal drainage with one-half-inch Penrose tubing installed just off the incision line is employed until drainage subsides. The abdomen should be irrigated with antibiotics and lactated Ringer's solution before closure. The abdomen is closed with simple interrupted sutures of stainless steel wire because of the long incision, the weight of the abdominal viscera, the
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WILLIAM D. DEHOFF, RIC HARD W. GREENE
Figure 8. At the time of necropsy, the stomach of this dog with gastric torsion is severely dilated and traumati zed.
possibility of peritonitis, and the delayed h ealing time associated with gastric torsion. Antibiotics are administered orally for the intestinal tract, as well as systemically. The animal is usually hospitalized for about five d ays. Oral administration of food and water is resumed gradually as gaseous gastric distention is controlled. The feeding regimen is similar to that described for gastric dilatation. We suggest that a less bulky diet tha n the animal had before torsion be fed more than once a day and that the animal be fed after exercise. The owner must understand th at gastric torsion may recur. In summary, we believe that the gastric torsion complex is the sin gle end-point for a variety of etiologic factors, none of which has been proved beyond doubt. Regardless of its cause, it is one of the most challenging problems e ncounte red in the abdomen . We recommend a strong surgical approach for correction of gastric torsion. If surgery is elected it should be performed immediately and quickly. The complex of gastric torsion and th e associated cardiovascular and pulmonar y complications must be dealt with aggressively. " Get in, get done, get out." (Author unknown) REFERENCES l. Andrews, A. H .: A study of ten cases of gastric torsion in the Bloodho und . Vet. Rec.,
86:689- 693 Uune 6, 1970).
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2. Berg, P.: Gastric torsion. In: Kirk, R. W. (ed.): Current Veterinary Therapy IV. Philadelphia, W. B. Saunders Company, 1971. 3. Bohning, R. H., et al.: Pharyngostomy for maintenance of the anorectic animal. J.A.V.M.A., 156, 5:61I-l5, 1970. 4. Funkguist, B.: Gastric torsion in the dog: non-surgical reposition. J. Small Animal Pract., 10:507-511, 1969. 5. Funkguist, B., and Garmer, L.: Pathogenetic and therapeutic aspects of torsion of the canine stomach. J. Small Animal Pract., 8:523-532, 1967. 6. Ross, G. E.: Gastric torsion. In: Kirk, R. W. (ed.): Current Veterinary III. Philadelphia, W. B. Saunders Company., 1968. 7. Severin, G. A.: Diseases of the digestive system. In: Catcott, E. J. (ed.): Canine Medicine. Wheaton, Illinois, American Veterinary Publications, Inc., 1968.
William D. DeHoff, D.V.M., M.S.* Richard W. Greene, D.V.M.**
Gastric torsion is always associated with and is probably preceded by gastric dilatation, but gastric dilatation can and does occur as a separate entity.
GASTRIC DILATATION Gastric dilatation occurs in all breeds at any age and is often selflimiting, owing to the animal's ability to empty its stomach either through vomiting or passage of contents into the duodenum. Among the common etiologic factors of gastric dilatation are general anesthesia, abdominal surgery, traumatic injury, spinal injury, overeating, pica, ingestion of foreign materials, parturition, vomiting, abnormal swallowing of air, and malignant tumors. 7 These causes of gastric distention lead to reflex inhibition of the normal gastric motor and secretory functions, either by direct distention and irritation of the gastric wall or by their action on the sympathetic pathways. The resulting situation may be transient, as when puppies are overfed, 7 but if the distention is prolonged, medical and even surgical intervention may be necessary. The signs of gastric dilatation are a distended, painful anterior abdomen; restlessness; nonproductive vomiting; and excessive salivation. The severity of signs depends on the severity of the dilatation. The diagnosis is based on the history, which may indicate a chronic problem; the clinical signs, most important of which is abdominal dis ten*Head of Surgery, The Animal Medical Center, New York, New York 10021; Diplomate, American College of Veterinary Surgeons. **Staff Surgeon, Section of General Surgery, The Animal Medical Center, New York. New York 10021. The authors thank Mrs. Mary B. Brown, Miss Deena Wolfson, and Mrs. Nancy Sturge for their assistance in the preparation of the manuscript. Veterinary Clinics of North America- Vol. 2, No. I Qanuary, 1972).
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WILLIAM D. DEHOFF, RICHARD
w.
GREENE
tion; radiographic findings, if examination is possible without stressing the animal; and relief of the distention by passage of a stomach tube.
TREATMENT
The first objective in treating gastric dilatation is to correct the distention. The etiology should then be determined. When dilatation is severe, attempts should be made to relieve the distention promptly and with as little stress as possible to avoid complications. Electrolyte imbalance, respiratory embarrassment, vascular hypotension, and gastric mucosal devitalization due to prolonged dilatation are among the secondary problems associated with gastric dilatation. Simple Gastric Dilatation A pliable vinyl plastic stomach tube of moderate firmness usually can be passed using an oral speculum. If difficulty is encountered while passing the tube, the animal should be anesthetized and a straight metal gastric tube passed gently into the stomach, being careful not to traumatize the esophagus. After the distention has been relieved, the metal tube is removed and is replaced by a vinyl tube with a relatively large bore. Because the vinyl tube conforms to the shape of the esophagus, fewer vital structures such as the heart are displaced. If anesthesia is necessary, the animal should be placed on an inclined table with its head down, followed by insertion of a cuffed endotracheal tube to prevent inhalation pneumonia. Positive pressure ventilation should be employed, and intravenous fluid therapy with lactated Ringer's solution and sodium bicarbonate should be instituted. If the dilatation has been associated with the ingestion of excessive food or foreign material, gastric lavage with warm saline should be repeated until all such material is removed. If gastric dilatation occurs repeatedly, a pharyngostomy should be performed and the flexible tubing inserted into the stomach via the pharyngostomy. This tube enables release of additional gases and fluids that might accumulate. The technique for pharyngostomy is quite simple. 3 The animal is placed in lateral recumbency under general anesthesia; in some cases, sedation and local anesthesia may suffice. After surgical preparation ofthe area just posterior to the angle of the mandible, the mouth is held open with the aid of an oral speculum, and an index finger is inserted into the retropharyngeal pouch (piriform fossa), located in the pharynx near the base of the tongue, posterior to the hyoid apparatus (Fig. 1). The index finger is then replaced with a large, curved hemostat, causing the skin to bulge outward. A small incision is
143
GASTRIC DILATATION AND THE GASTRIC TORSION COMPLEX
Stylohyoid Epiglottis
Thyrohyoid -",..::>,...----"'
Thyroid cartilage Cricoid cartilage Trach9a
Figure l. Prior to making the pharyngostomy incision, th e index finger is inserted into the retropharyngeal pouch (piriform fossa) posterior to the hyoid apparatus. (From Pharyngostomy .for iHaintenaru;e of the Anorectic Animal, by R. H . Bohning·, .Jr., W. D. DeHoff, A. McElhinne y, and P. C. Hofstra., J.A.V.M.A., 156, .'>:611 - l!'i , 1970, used by permission.)
made through the skin and underlying fascia. The hemostat is then forced out through the skin incision from inside the pharynx. The tubing, which is precut to the proper length according to the distance from the angle of the jaw to the last rib, is pulled into the pharynx with the forceps and passed down the esophagus into the stomach. The tubing is then secured to the skin with a pursestring suture. The pharyngostomy tube is useful for administering food and water, as well as for relieving accumulation of gas within the stomach. The animal can also eat and drink with the tube in place without discomfort (Fig. 2). The tube is removed by cutting the pursestring suture and gently drawing the tube out. The wound heals without sutures in seven days. As a general rule, the tube is left in place until the animal has been asymptomatic for 24 to 48 hours. All animals treated for gastric dilatation, with or without a pharyngostomy tube, are fed light, brothy meals three to five times a d ay for two to three d ays before a more normal diet is reestablished. When normal feeding is resumed, it is recommended that relatively soft foods be given and that the animal be fed more than once a day.
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WILLIAM D. D EHOFF, RICHARD
Figure 2.
w. GREENE
l'haryngostomy tube in p lace.
Gastric Dilatation with Complications
Whe n complications ar e associated with gastric dilatation , further diagnostic studies are indicated. The history should be reviewed as to previous occurrences , die t , and hereditar y background. T h e radiographic examination is important in this phase of follow-up care. The evaluation of gastric a nd pyloric function can be d ifficult because of th e wide range of acceptable gastric emptying times, motility, size, a nd shape. It is important to h ave a good standard r adiographic technique for gastr ic studies to reduce th e numbe r of variables. Diagnosis can be b ased more easily on radiographic eviden ce of foreign bodies or malign ant tumors tha n on delayed gastric emptying times. If the gastric emptying time is d elayed or a ppears abnor mal in any way, a nd if there are no other diagnostic clues, we recomme nd p yloroplasty or pyloric bypass on an elective basis. A pyloroplasty ensures a wide opening for passage of gastric conte nts and forms an area that will not go into spasm . A number of different p yloroplasties and pyloric bypass procedures are available, ranging from simple m yoto mies to more involved an astomotic techniques. Gene rally, the more sophisticated surgery results in a wider openin g into the small bowel. T h e Fredet- Ramstedt pyloroplasty is a m yotomy in which the incision is carried down to but not throu gh the mucosa, so that the mucosa can bulge ou tward. A lon gitudin al incision exte nding 1 to 2 em . on either side of the pylorus is made on the ventral surface of the p ylorus u sing a No. 15 Bard-Parker scalpel blade. It is usu ally easie r to carry the
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Figure 3. The Fredet-Ramstedt pYloroplastY. Th e circular muscle ar ound the p ylorus is simply freed, allowing the m ucosa to bu lge out\\"ard .
incision down to the mucosa OYer the stomach and then extend it onto the duodenum. All restricting bands of circular muscle should be cut. The incised walls are then undermined a nd dissected away from the mucosa until about 50 per cen t of the circum ference is freed (Fig. 3). Another p yloroplastY . the Heineke- l\Iikulicz procedure, involves a lo n gitudinal incision similar to that for the Fredet- Ramstedt p ylon)plasty, but the incision pe netrates the mucosa. The longitudinal incision is sutured in a simple interrupted pattern h orizontally, resulting in a shortening and widening of the pyloric canal. This technique is useful if the mucosa has been d amaged during a Fredet-Ramstedt myotomy. A gastroduodenostom y is incorporated in the Finney p yloroplasty. This procedure yields a much wider opening between the stomach and the duodenum. T he incision is made in the sam e location as th e previously described pyloroplasty, but it is extended further down the antemesenteric border of the duodenum and aroun d on the stom ach near the gr eater curvature . The incision is then closed by first suturing together the farthest edges of the duodenum and sto mach and then suturing the near edges of the duodenum and stomach, form in g a large opening between them . T he fourth technique employed to facilitate gastric emptying is a gastroduod e nostomy. T his technique establish es a separate gastroduodenal anastomosis, leaving the pylorus intact. T he latter two techniques, the Finney pyloroplasty and the gastroduodenostomy, are the techniques preferred in dogs of large breeds which have recurrent episodes of gastric dila tation. Eithe r of these tech -
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WILLIAM D. DEHOFF, RICHARD
w.
GREENE
mques can be performed on an elective basis in a period when the animal is in good health and is able to withstand a more definitive procedure.
DIFFERENTIAL DIAGNOSIS
The differential diagnosis of a gastric dilatation is extremely important, since gastric torsion and intestinal volvulus are more life-threatening conditions than gastric dilatation. The clinical signs and history of all three conditions are similar, and the three conditions occur in all breeds and age groups. Signs which suggest intestinal volvulus rather than gastric dilatation and torsion are productive vomiting; lack of excessive salivation; uniform abdominal distention, rather than only the anterior portion; and easy passage of a stomach tube without relief of abdominal distention. The clinical signs of intestinal volvulus are less dramatic than those of gastric dilatation and torsion. Abdominal distention is less severe, and the clinical course of the condition is more protracted. Radiographically, intestinal volvulus is readily differentiated from dilatation or torsion of the stomach by the presence of large, air-filled loops of bowel throughout the abdomen and by the absence of gas in the stomach. In contrast, a large, dilated, balloon-like mass is seen in the anterior abdomen in gastric dilatation and torsion (Fig. 4).
THE GASTRIC TORSION COMPLEX Although simple gastric dilatation and intestinal volvulus are serious medical-surgical problems, definitive diagnosis and treatment are possible, and the prognosis is relatively good. The gastric torsion complex, on the other hand, has a more guarded prognosis because of the complications associated with the disease, such as severe shock; because a major surgical procedure must be undertaken to treat the condition; and because recurrence is common. It is generally agreed that gastric distention precedes gastric torsion.5 However, the etiology of gastric torsion has been widely debated. Such diverse factors as stretched gastric ligaments, calcium-phosphorus imbalances, pendulous, food-filled stomachs, distended spleens, anatomic predispositions, excessive postprandial exercise, and inherited defects and weakness have all been proposed.L 2 • 4 • 5· 6 There seems to be no sex predilection in animals affected. The condition does show certain patterns that seem significant. It most frequently affects dogs of the large, deep-chested breeds, such as the Great Dane, Standard Poodle, Boxer, Irish Setter, Weimaraner, English Sheepdog, Irish Wolfhound, Saint Bernard, and Bloodhound.
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Figure 4. Lateral abdominal radiogr aph of a dog with gastric torsion. The stomach is gas-filled, and the anterior abdomen is distended.
Animals affected usually h ave been fed a large m eal of bulky consistency two to six hours before presentation. T hey are often fe d and watered once a d ay, and then are exer cised shortly th er eafter. T here is often a history of periodic gastritis , and rela ted individuals m ay have had the same problem. Dogs with gastric torsions a re usually presented to our hospital as emergencies between 10:00 P.M. and 7:00 A.M. owing to the animals' feeding h abits and exercise schedules. T he clinical signs are similar to those of gastric d ilatation. Castric torsion should be regarded as an emergency, and the prognosis should be guarded.
TREATMENT There is no consensus r egardin g a specific treatme nt for gastric torsion. Several m ethods are available, d e pending on th e severity of the case. Over 60 cases of gastric torsion h ave been treated at T h e Animal Medical Cente r in the last five years. Based on this experience and o n the work of oth ers, we have arrived at a relatively consistent approach to its treatment. A few points regarding the gastric torsion complex should be e mphasized. Immediate diagnosis and treatment are critical. The earlier the condition is diagnosed and treated , the better the prognosis. T he
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dilatation associated with prolonged gastric torsion can lead to necrosis and even rupture of the stomach wall. The prognosis is understandably poor in this instance. The most serious preoperative complications associated with the condition include shock, electrolyte imbalance, and cardiorespiratory embarrassment. As the gastric distention increases, the portal vein and caudal vena cava become partially occluded. The venous return from the spleen is also slowed, causing the organ to become engorged (Fig. 5). These circulatory complications lead to h ypotension because the volume of blood returning to the heart is reduced. The anterior displacement of the enlarged stomach also interferes with the capacity of the diaphragm to expand with ventilation. Because of these difficulties, the animal is often presented in some degree of shock, showing signs of increased heart rate, delayed capillary filling, and d yspnea. Total collapse is often imminent; therefore, long delays in diagnosis or treatment must be avoided. A number of different programs of treatment have been recommended, but they are all geared initially to restoring the deteriorating cardiovascular function, decompressing the gastric distention, and realigning the displaced organ stru ctures. As previously described, the vinyl stomach tube is passed gently. If the tube cannot be passed into the stomach, the animal should be anesthetized, positive pressure ventilation utilizing a cuffed endotracheal tube instituted, and a metal stomach tube passed. If this tube cannot be passed, the diagnosis of gastric torsion complex is confirmed. We recommend immediate abdominal surgery, although its value has been ques-
Figure 5. The spleen in this dog with gastric LOrsion was markedly e ngorged .
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tioned by Funkquist, et a!. , who recommend a more conservative approach.4 If the stomach tube does enter the stomach, the case is treated as a dilatation as previously discussed. If gas continues to accumulate within the stomach, even though the tube entered the stomach, o r if the animal's general discomfort and state of shock do not impr ove, an exploratory laparotomy is also recommended. In this instance, it is possible that the stomach and spleen are twisted, even though the gaseous distention has been relieved. Before the abdomen is explored, the cardiopulmonary system should be monitored and supportive therapy in stituted if necessary. An endotrach eal tube is passed and inflated to prevent inhalation pneumonia and to permit assisted ventilation. A jugular catheter is inserted to enable administration of fiuids and monitorin g of central venous pressure. Cortisone and antibiotics are administe r ed via this route when shock is a proble m. Cardiac function should be monitored continuously while the animal is being prepared for surgery. The animal's already compromised cardiopulmonary status is further stressed when the animal is anesthetized and placed on its back. In this position, further pressure is applied to the diaphragm, caudal vena cava, and portal veins. Attention to the positioning is important throughout the surgical procedure . A ventral midline incision is employed, extending from the xyphoid cartilage to well below the umbilicus to permit ease of manipulation of the dilated stomach and spleen (Fig. 6). The stomach usually can be repositioned by rotating it counterclockwise, since the torsion is usually
Figure 6. In dogs with gastric torsion, a large incision is necessary to reposition the enlarged stomach and engorged spleen. Note the use of self-retaining Balfour abdominal retractors in the anterior p art of the incision.
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GREENE
clockwise for 90° to 360°, with the pylorus ventral to the stomach. 6 The repositioning can be aided by passing a large stomach tube and palpating the direction of the torsion of the distal esophagus and cardiac portion of the stomach. If this is impossible, gastric paracentesis can be performed, with the needle connected to rubber tubing so that the contents can be expelled directly into a container, thus preventing contamination of the abdomen. When the dilatation has been reduced, the stomach can be repositioned. Ideally, paracentesis should be avoided. After the stomach and spleen have been repositioned, a soft, pliable tube is guided from the mouth into the stomach, and gastric lavage with saline solution is repeated until all debris has been removed. The animal's general condition should be improving by this time. If large particles in the stomach cannot be washed out, a gastrotomy should be performed. To accomplish this, the stomach is packed off with warm towels moistened with saline, and an incision is made on its ventral surface midway between the omental borders. The wound can be held open with Allis tissue forceps or with retention sutures placed to hold the incision open for visualization and manipulation of the stomach. After all material has been removed from the stomach, and after the stomach wall has been inspected, the gastrotomy is closed with 00 chromic catgut in a two-layered, inverting continuous suture pattern, with the first layer of sutures penetrating the mucosa. The stomach should be examined for areas of necrosis. Because of its excellent blood supply, color should return quickly if the tissue is viable. If areas of the stomach wall are avascular or necrotic, the prognosis is grave. All necrotic portions must be removed (Fig. 7). Fortunately, this is an uncommon complication. It is sometimes necessary to perform a splenectomy to aid repositioning of the stomach but we do not recommend the procedure as a general rule. The spleen and its vascular supply should be examined for damage, and a partial or total splenectomy considered if indicated. The spleen may play some role in the production of gastric torsion, although we have seen the condition in animals which have had splenectomies previously. The next measure is pyloroplasty, since abnormal pyloric function is believed to be part of the etiology,L 4 • 5 and we perform pyloroplasty in all cases. Because the animal with gastric torsion has experienced a major insult, the procedure of choice is one that can be done quickly without further compromising the over-all success of the correction. The Fredet-Ramstedt or Heineke-Mikulicz procedure is usually elected, and the Fredet-Ramstedt pyloroplasty can be accomplished in less than five minutes. The pyloric musculature in many of these animals, especially those over five to six years of age or those in which gastritis has occurred repeatedly, often has some type of abnormality. A pyloroplasty will prevent spasm of the pylorus, whatever the cause, and promote more rapid gastric emptying.
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Figure 7. Gross specimen of a stomach that was resected after prolonged dilatatio n associated with gastric torsion. Much of the mucosal surface is necrotic.
The next consideration is a gastropexy; in theory, if the stomach or those structures that are able to twist can be fixed in normal positions, torsion cannot recur. This technique has not been successful in our hands to date. Dogs reoperated following gastropexy, including those with recurrent gastric torsions, have not been found to have any perman ent gastric adhesions. Plication of the lesser omentum has been suggested, as has a gastrostomy to prevent accumulation of gas postoperatively;2 when the gastrotomy is closed over, a solid, stabilizing gastropexy should result. We believe the theory of gastropexy h as great merit, but to date we have not achieved the permanent fixation desired without undertaking an involved procedure. If the stom ach h as been severely dilated and traumatized (Fig. 8) where further accumulation of gas is anticipated postoperatively, which would compromise the stomach's viability, we use a pharyngostomy tube until normal feeding can be resumed. If the pylorus or stomach has been opened, abdominal drainage with one-half-inch Penrose tubing installed just off the incision line is employed until drainage subsides. The abdomen should be irrigated with antibiotics and lactated Ringer's solution before closure. The abdomen is closed with simple interrupted sutures of stainless steel wire because of the long incision, the weight of the abdominal viscera, the
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Figure 8. At the time of necropsy, the stomach of this dog with gastric torsion is severely dilated and traumati zed.
possibility of peritonitis, and the delayed h ealing time associated with gastric torsion. Antibiotics are administered orally for the intestinal tract, as well as systemically. The animal is usually hospitalized for about five d ays. Oral administration of food and water is resumed gradually as gaseous gastric distention is controlled. The feeding regimen is similar to that described for gastric dilatation. We suggest that a less bulky diet tha n the animal had before torsion be fed more than once a day and that the animal be fed after exercise. The owner must understand th at gastric torsion may recur. In summary, we believe that the gastric torsion complex is the sin gle end-point for a variety of etiologic factors, none of which has been proved beyond doubt. Regardless of its cause, it is one of the most challenging problems e ncounte red in the abdomen . We recommend a strong surgical approach for correction of gastric torsion. If surgery is elected it should be performed immediately and quickly. The complex of gastric torsion and th e associated cardiovascular and pulmonar y complications must be dealt with aggressively. " Get in, get done, get out." (Author unknown) REFERENCES l. Andrews, A. H .: A study of ten cases of gastric torsion in the Bloodho und . Vet. Rec.,
86:689- 693 Uune 6, 1970).
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2. Berg, P.: Gastric torsion. In: Kirk, R. W. (ed.): Current Veterinary Therapy IV. Philadelphia, W. B. Saunders Company, 1971. 3. Bohning, R. H., et al.: Pharyngostomy for maintenance of the anorectic animal. J.A.V.M.A., 156, 5:61I-l5, 1970. 4. Funkguist, B.: Gastric torsion in the dog: non-surgical reposition. J. Small Animal Pract., 10:507-511, 1969. 5. Funkguist, B., and Garmer, L.: Pathogenetic and therapeutic aspects of torsion of the canine stomach. J. Small Animal Pract., 8:523-532, 1967. 6. Ross, G. E.: Gastric torsion. In: Kirk, R. W. (ed.): Current Veterinary III. Philadelphia, W. B. Saunders Company., 1968. 7. Severin, G. A.: Diseases of the digestive system. In: Catcott, E. J. (ed.): Canine Medicine. Wheaton, Illinois, American Veterinary Publications, Inc., 1968.