Gastric Patch Esophagoplasty:An Experimental Study T. 6. Hugh, FRCS, FRACS, Sydney, Australia R. J. Lusby, MB, BS, Sydney, Australia M. J. Coleman, MB, BS, FRACS, Sydney, Australia
In the preceding article [I] we suggested the use of full-thickness pedicled segments of gastric wall for reconstruction of the strictured ksophagus. Although ectopic gastric mucosal islands in the esophagus have been reported, there do not appear to.have been any studies of artificially created gastric mucosal patches in the esophagus. The present study examines the response of the canine esophagus to full-thickness pedicled patches covered with antral or parietal cell mucosa, and determines whether SUCK ectopic gastric mucosa produces an increase in serum gastrin levels. Material and Methods
Studies were carried out in eleven adult mongrel dogs weighing 12 to 25 kg each. The animals were fasted overnight, and serum was collected for gastrin assay. Under general anesthesia and positive pressure ventilation, a thoracoabdominal incision was made. A pentagastrin infusion (6 pg/kg/hr) was commenced and a longitudinal anterior gastrotomy performed to enable selection of the site of the patch. The distal limit of the parietal cell area was determined by testing the mucosa with a pH probe, and the patch area along the greater curvature was then carefully delineated. In five dogs patches were derived from the parietal cell area and in five from the gastric antrum; in one control animal no operation was done. A vascular pedicle to the selected area was developed by dividing the gastric and omental branches of the gastroepiploic vessels, preserving two or three branches to the area of the patch. The arcade was then divided either to the left or to the right of the patch and a full-thickness ellipse, 5 by 2 cm, excised from the stomach, stiil tethered by a vascular pedicle based on the right or left gastroepiploic vessels; (Figure 1.) The patch was then passed posteriorly to the stomach and into the chest via a lateral incision in the diaphragm, care being taken to avoid damage to the esophageal hiatus. The defect in the stomach was closed transversely. A lon-
From St. Vincent’s Medical Centre, Sydney, Australia. Reprint requests should be addressed to T. 6. Hugh, FRCS. St. Vincent’s Medical Centre, 376 Victoria Street, Darlinghurst, NSW 2010. Australia.
226
gitudinal incision was made in the esophagus 5 cm above the diaphragm and the patch sutured in place, mucosal side to lumen, with in@rrupted absorbable sutures. (Figure 1.) An intravenous infusion of 5 per cent dextrose in fifthnormal saline was given, followed by water orally as desired for 4%hours. A soft diet was given for one week followed by a balanced dog diet. Intramuscular penicillin and streptomycin were given for five days. Serum for fasting gastrin assay was taken at intervals postoperatively, and endoscopy was carried out within the first postoperative month. Five dogs with esophageal patches and one control animal were chronically stimulated by the method of Hay [2], using daily intramuscular injections of histamine in beeswax.for one week before sacrifice. The presence of esophagitis was assessed by endoscopic appearances, gross appearance at autopsy, and histologic examination of biopsy and autopsy material. Serum gastrin levels were determined by radioimmunoassay using the method of Byrnes et al [3]. Results
The mean survival was 112 days, with a range of 1 to 252 days. Two animals died within 48 hours of operation, one from suture line leakage and another from food inhalation because of accidental preoperative feeding. Esophagitis developed in three of five surviving dogs with parietal cell patches but was not found in dogs with antral patches. Esophagitis in the affected dogs was detectable endoscopically within the first month after operation as an area of erythema with superficial ulceration in the esophageal epithelium localized adjacent to the patch. There was no evidence of gastroesophageal reflux in any dog. Six dogs (1 control, 3 with antral patches, and 2 with parietal patches) received histamine stimulation for one week prior to sacrifice..Duodenal ulceration developed in all, indicating adequate stimulation of gastric secretion. Marked localized esophagitis with superficial ulceration was present at autopsy in both histamine-stimulated dogs with parietal cell patches, but esophagitis was not present in any of the three
The American Journal of Surgery
Gastric Patch Esophagoplasty
1
: PRE
OPERATIVE
POST
OPERATIVE
F~~2.Meenserwngaslrk,le~k,dogsbeforea~afle~ construction of esqhageal gas&k patches lined wtth paf&tat cell mucosa and gastrk an&al nwcosa. l = parletal patch; 0 = an&a/patch. Figure 1. Operathfe technic for constructkn of canine esophageal gas&k patches llned wtthpa&tat cell mucosa and gastric antrat mucosa.
histamine-stimulated dogs with antral patches, thus indicating that even under conditions of stimulation, patches of antral mucosa in the canine esophagus are nonirritating. Due to technical difficulties with the assay, reliable fasting serum gastrin levels were obtained in only five dogs. In these animals no postoperative increase in the serum gastrin level was noted. (Figure 2.) Comments
These studies indicate that it is feasible to implant pedicled gastric patches in the canine esophagus. When the patch is covered with parietal cell mucosa, localized esophagitis adjacent to the patch is likely, especially under conditions of gastric secretory stimulation. In unstimulated animals esophagitis can occur even though the patch, by virtue of its derivation from the greater curvature, is probably vagally denervated. On the other hand, patches covered with antral mucosa do not cause esophageal mucosal inflammation even under stimulated conditions, and for this reason such patches might be suitable for use in esophageal reconstruction. Although gastric antral mucosa does contain some parietal cells 141,the cells do not appear to be in sufficient density to cause significant acid secretion in the esophagus. Surprisingly, no increase in serum gastrin levels, with a consequent risk of gastric acid hypersecretion and peptic ulceration, was noted in animals with
Volume 137, February 1979
antral patches in the esophagus, despite the fact that the antral mucosa of the patch was removed from the inhibiting effect of acid gastric secretions. It is possible that the area of antral mucosa was too small to secrete significant amounts of gastrin; alternatively, the pH of the lower esophagus may be sufficiently low to ensure inhibition. Similarly, no evidence of gastric acid hypersecretion was noted by Leong and Ong [5] when antral mucosa was transplanted to the urinary bladder. Summary
To determine whether the use of pedicled fullthickness gastric patches would be feasible and safe in esophageal reconstruction, studies were undertaken in eleven dogs. The results demonstrate that patches containing parietal cell mucosa are likely to produce localized adjacent esophagitis. Patches containing antral mucosa do not produce esophagitis and are not associated with a subsequent increase in circulating serum gastrin levels. References 1. Hugh TB, Lusby RJ, Coleman MJ: Antral patch esophagoplasty. A new procedure for acid-peptic esophageal stricture. Am J Surg 137: 221, 1979. 2. Hay W: The experimental production of gastric and duodenal ulcers in laboratcq animals by the intramuscular injection of histamine in beeswax. Surg ciynecol Obstet 75: 170, 1942. 3. Byrnes DJ, Young JD, Chisholm DJ, Lazarus L: Serum gastrin in patients with peptic ulceration. Br Med J 2: 262, 1970. 4. Tominaga K: Distribution of parietal cells in the antral mucosa of human stomachs. GastroenteroIogy69: 1201, 1975. 5. Leong CH, Ong GB: Gastrocystoplasty. 6r J Ural 47: 236, 1975.
227
In the preceding article [I] we suggested the use of full-thickness pedicled segments of gastric wall for reconstruction of the strictured ksophagus. Although ectopic gastric mucosal islands in the esophagus have been reported, there do not appear to.have been any studies of artificially created gastric mucosal patches in the esophagus. The present study examines the response of the canine esophagus to full-thickness pedicled patches covered with antral or parietal cell mucosa, and determines whether SUCK ectopic gastric mucosa produces an increase in serum gastrin levels. Material and Methods
Studies were carried out in eleven adult mongrel dogs weighing 12 to 25 kg each. The animals were fasted overnight, and serum was collected for gastrin assay. Under general anesthesia and positive pressure ventilation, a thoracoabdominal incision was made. A pentagastrin infusion (6 pg/kg/hr) was commenced and a longitudinal anterior gastrotomy performed to enable selection of the site of the patch. The distal limit of the parietal cell area was determined by testing the mucosa with a pH probe, and the patch area along the greater curvature was then carefully delineated. In five dogs patches were derived from the parietal cell area and in five from the gastric antrum; in one control animal no operation was done. A vascular pedicle to the selected area was developed by dividing the gastric and omental branches of the gastroepiploic vessels, preserving two or three branches to the area of the patch. The arcade was then divided either to the left or to the right of the patch and a full-thickness ellipse, 5 by 2 cm, excised from the stomach, stiil tethered by a vascular pedicle based on the right or left gastroepiploic vessels; (Figure 1.) The patch was then passed posteriorly to the stomach and into the chest via a lateral incision in the diaphragm, care being taken to avoid damage to the esophageal hiatus. The defect in the stomach was closed transversely. A lon-
From St. Vincent’s Medical Centre, Sydney, Australia. Reprint requests should be addressed to T. 6. Hugh, FRCS. St. Vincent’s Medical Centre, 376 Victoria Street, Darlinghurst, NSW 2010. Australia.
226
gitudinal incision was made in the esophagus 5 cm above the diaphragm and the patch sutured in place, mucosal side to lumen, with in@rrupted absorbable sutures. (Figure 1.) An intravenous infusion of 5 per cent dextrose in fifthnormal saline was given, followed by water orally as desired for 4%hours. A soft diet was given for one week followed by a balanced dog diet. Intramuscular penicillin and streptomycin were given for five days. Serum for fasting gastrin assay was taken at intervals postoperatively, and endoscopy was carried out within the first postoperative month. Five dogs with esophageal patches and one control animal were chronically stimulated by the method of Hay [2], using daily intramuscular injections of histamine in beeswax.for one week before sacrifice. The presence of esophagitis was assessed by endoscopic appearances, gross appearance at autopsy, and histologic examination of biopsy and autopsy material. Serum gastrin levels were determined by radioimmunoassay using the method of Byrnes et al [3]. Results
The mean survival was 112 days, with a range of 1 to 252 days. Two animals died within 48 hours of operation, one from suture line leakage and another from food inhalation because of accidental preoperative feeding. Esophagitis developed in three of five surviving dogs with parietal cell patches but was not found in dogs with antral patches. Esophagitis in the affected dogs was detectable endoscopically within the first month after operation as an area of erythema with superficial ulceration in the esophageal epithelium localized adjacent to the patch. There was no evidence of gastroesophageal reflux in any dog. Six dogs (1 control, 3 with antral patches, and 2 with parietal patches) received histamine stimulation for one week prior to sacrifice..Duodenal ulceration developed in all, indicating adequate stimulation of gastric secretion. Marked localized esophagitis with superficial ulceration was present at autopsy in both histamine-stimulated dogs with parietal cell patches, but esophagitis was not present in any of the three
The American Journal of Surgery
Gastric Patch Esophagoplasty
1
: PRE
OPERATIVE
POST
OPERATIVE
F~~2.Meenserwngaslrk,le~k,dogsbeforea~afle~ construction of esqhageal gas&k patches lined wtth paf&tat cell mucosa and gastrk an&al nwcosa. l = parletal patch; 0 = an&a/patch. Figure 1. Operathfe technic for constructkn of canine esophageal gas&k patches llned wtthpa&tat cell mucosa and gastric antrat mucosa.
histamine-stimulated dogs with antral patches, thus indicating that even under conditions of stimulation, patches of antral mucosa in the canine esophagus are nonirritating. Due to technical difficulties with the assay, reliable fasting serum gastrin levels were obtained in only five dogs. In these animals no postoperative increase in the serum gastrin level was noted. (Figure 2.) Comments
These studies indicate that it is feasible to implant pedicled gastric patches in the canine esophagus. When the patch is covered with parietal cell mucosa, localized esophagitis adjacent to the patch is likely, especially under conditions of gastric secretory stimulation. In unstimulated animals esophagitis can occur even though the patch, by virtue of its derivation from the greater curvature, is probably vagally denervated. On the other hand, patches covered with antral mucosa do not cause esophageal mucosal inflammation even under stimulated conditions, and for this reason such patches might be suitable for use in esophageal reconstruction. Although gastric antral mucosa does contain some parietal cells 141,the cells do not appear to be in sufficient density to cause significant acid secretion in the esophagus. Surprisingly, no increase in serum gastrin levels, with a consequent risk of gastric acid hypersecretion and peptic ulceration, was noted in animals with
Volume 137, February 1979
antral patches in the esophagus, despite the fact that the antral mucosa of the patch was removed from the inhibiting effect of acid gastric secretions. It is possible that the area of antral mucosa was too small to secrete significant amounts of gastrin; alternatively, the pH of the lower esophagus may be sufficiently low to ensure inhibition. Similarly, no evidence of gastric acid hypersecretion was noted by Leong and Ong [5] when antral mucosa was transplanted to the urinary bladder. Summary
To determine whether the use of pedicled fullthickness gastric patches would be feasible and safe in esophageal reconstruction, studies were undertaken in eleven dogs. The results demonstrate that patches containing parietal cell mucosa are likely to produce localized adjacent esophagitis. Patches containing antral mucosa do not produce esophagitis and are not associated with a subsequent increase in circulating serum gastrin levels. References 1. Hugh TB, Lusby RJ, Coleman MJ: Antral patch esophagoplasty. A new procedure for acid-peptic esophageal stricture. Am J Surg 137: 221, 1979. 2. Hay W: The experimental production of gastric and duodenal ulcers in laboratcq animals by the intramuscular injection of histamine in beeswax. Surg ciynecol Obstet 75: 170, 1942. 3. Byrnes DJ, Young JD, Chisholm DJ, Lazarus L: Serum gastrin in patients with peptic ulceration. Br Med J 2: 262, 1970. 4. Tominaga K: Distribution of parietal cells in the antral mucosa of human stomachs. GastroenteroIogy69: 1201, 1975. 5. Leong CH, Ong GB: Gastrocystoplasty. 6r J Ural 47: 236, 1975.
227
