E.R. Woodward

Combined radiographic, manometric, and histologic localization of the canine lower esophageal sphincter☆

Abstract The localization of the lower esophageal sphincter at the canine esophagogastric junction was investigated by employing radiopaque sutures as reference points for a combined radiographic, manometric, and histologic study. The three reference points were: the junction of squamous and columnar epithelium, the point where the tubular esophagus joins the saccular stomach, and the inferior margin of the diaphragmatic erura which separates the peritoneal cavity from the erural canal. Radiographically, the squamocolumnar epithelial junction was midway between the esophagogastric junction and the abdominal margin of the esophageal hiatus. Manometrically, the high-pressure zone (HPZ) extended above, as well as below the squamocolumnar epithelial junction. The manometric limits of the HPZ correspond to the thickened band of circular smooth muscle comprising the upper circular fibers of the gastric sling (sling of Willis). These fibers constitute the lower esophageal sphincter and lie between the esophagogastric junction and the abdominal margin of the esophageal hiatus.

Collagen content, histology, and tensile strength: determinants of wound repair in various gastric stapling devices in a canine gastric partition model

Various stapling devices have been applied to create the small gastric pouch necessary for effective weight loss in morbid obesity, but it is unclear as to which staple line arrangement provides the most reliable gastric wound healing. Five variants of staple lines (Groups I-V) were used to create a gastric partition in 47 adult mongrel dogs (20-30 kg). Staple-line arrangements were as follows: Group I (n = 10)--two superimposed double rows (TA-90), Group II (n = 10)--prototype staple line of four rows 2.03 mm apart, Group III (n = 12)--two double rows of staples 6.5 mm apart, Group IV (n = 10)--prototype staple line of two double rows of staples 0.64 mm apart, and Group V (n = 5)--a single double-row staple line (TA-90). Staple lines were examined at 2, 4, 8, and 13-16 weeks for evidence of healing, histology, tensile strength, and collagen (hydroxyproline) content. Significant differences in staple-line disruption rates were found between all groups (chi 2, P less than 0.01). The prototype four-row staple line (Group II) had the most significant parameters of wound repair determined by biochemical evidence of wound healing and enhanced tensile strength. Staple-line arrangement appears to be an important determinant of gastric wound healing and may influence the rate of postoperative gastric partition disruption.

An analysis of recurrent esophagitis following posterior gastropexy.

Surgical therapy for reflux esophagitis remains controversial. Sixty-five patients who underwent posterior gastropexy between November, 1970 and February, 1976 are presented. Indications for surgery were: esophagitis, 43 patients; esophagitis with stricture, 12 patients; paraesophageal hernia, seven patients; incapacitating postfundoplication syndrome, three patients. The average follow-up was 15.6 months. Eighty-two per cent of the patients had a good to excellent result. Twenty-three per cent of the patients developed radiographically recurrent hiatus hernia; however, the incidence of recurrent esophagitis was only nine per cent. Two patients developed postoperative strictures (one de novo, one recurrent). Two patients ultimately required a fundoplication for control of their esophagitis; one patient required a Thal-Nissen procedure. Lower esophageal sphincter pressure on patients with satisfactory results increased from 6.3 ± 1.3 cm H2O SEM preoperatively, to 17.4 ± 3.0 cm H2O SEM postoperatively. This increase achieved a statistical significance of p < 0.001. In patients who had an unsatisfactory result, postoperative sphincter pressures were unchanged from preoperative values. All unsatisfactory results were obtained in patients with complicated esophagitis, i.e., Barretts ulcer or stricture, alkaline esophagitis, or previous hiatal surgery. Posterior gastropexy appears to constitute effective therapy in the treatment of uncomplicated reflux esophagitis and paraesophageal hiatus hernia without the distressing morbidity associated with the postfundoplication syndrome.

A new method for long-term measurement of gallbladder contraction in the conscious dog

Abstract A method is presented by which contractions of the gallbladder can be measured quantitatively in the chronic, unanesthetized dog. We feel this preparation is more physiologic than those previously described and has the added features of simplicity, ease of maintenance and accurate reproducibility. The three dogs reported were kept for 6 months and their gallbladder balloons continue to function. Biopsy of the gallbladders after the balloons had been in place for 6 months showed mild chronic cholecystitis. Comparison of the gallbladder contractile response to intravenous CCK and to intraduodenal 50 per cent olive oil emulsion indicates that this method can be used as a quantitative assay for in vivo cholecystokinin. One cubic centimeter per kilogram of 50 per cent olive oil in the duodenum appears to liberate approximately 1 unit/kg. of cholecystokinin.

The effect of feeding on the canine lower esophageal sphincter

Lower esophageal sphincter pressure (LESP) is known to increase in experimental animals and in man after the administration of exogenous gastrin or gastrin analog. This was first shown independently by two groups in 1969 [I, 31. These data led to the speculation that the lower esophageal sphincter (LES) is controlled by serum gastrin. In 1973, Grossman [4] questioned this hypothesis. He felt the response of the LES to serum gastrin concentrations might reflect the pharmacologic action of gastrin on the LES and not be a true representative of the physiologic response of the LES to the serum gastrin level. The purpose of this investigation is to determine the LESP before and after a physiologic stimulus to gastrin release. The physiologic stimulus chosen was feeding.

The influence of mesenteric denervation on the inhibition of gastric secretion by fat in the intestine

The inhibitory effect of fat in the upper small intestine was studied in dogs prepared with a Heidenhain pouch, gastric fistula, and jejunal fistula. Gastric secretion was stimulated by a constant intravenous infusion of pentagastrin, and emulsified olive oil was introduced into the jejunum. The small intestine of the dog was denervated by complete transection of the mesentery except for the superior mesenteric vessels. After intestinal denervation inhibition of the vagally innervated stomach was almost abolished while that in the Heidenhain pouch was unchanged. It is concluded that either autonomic innervation is important in the formation of enterogastrone or, more likely, that efferent inhibitory fibres in the vagus to the stomach act synergistically with enterogastrone.

The influence of bile on canine gastric secretion

Abstract The effect of various types of biliary diversion on the daily secretion of Heidenhain pouches in dogs was studied. Total external diversion of bile brought about a decrease in gastric secretion while simple internal diversion of bile to the distal gut via Roux-en-Y segment caused significant increase in Heidenhain pouch secretion; the observed increases in secretion could not be accounted for on the basis of impairment of liver function as measured by serial BSP determinations.

Conversion of Jejunoileal Bypass to Silastic Ring Vertical Gastroplasty

A gastric restrictive procedure is usually performed simultaneous with takedown of a jejunoileal bypass (JIB) to prevent weight regain. However, the preferred gastric restrictive procedure has not been established. Currently, we combine JIB takedown with silastic ring vertical gastroplasty (SRVG), and report our experience with 36 patients treated over a 5-year period. Indications for JIB takedown were diarrhea (69%), arthralgias (53%), liver disease (34%), nephrolithiasis (25%), and increasing weight (33%). Mean weight at the time of JIB takedown was 232 ± 12 (SEM) lb (105 ± 5 kg) (77 ± 8% EBW (excess body weight)). Follow-up was complete in 33 (92%) patients. Post-reversal weight was 202 ± 14 lb (92 ± 6 kg) (55 ± 8% EBW) at 1 year and 218 ± 12 lb (99 ± 5 kg) (67 ± 8% EBW) (not significant) at a mean follow-up of 2.9 years. Twenty-one (64%) patients lost weight or were stable (± 5% EBW), while 12 (36%) gained a mean of 39 ± 7 lb (18 ± 3 kg) (range 16-80 lb (7 ± 36 kg)). Resolution of preoperative complaints was noted in all patients with diarrhea and 53% with migratory arthralgias. Major early postoperative morbidity occurred in 11%, with no mortality. We conclude that SRVG is a safe and effective procedure to combine with JIB takedown.

Response of the canine lower esophageal sphincter to endogenous hypergastrinemia

Abstract The effects, if any, of endogenous gastrin on the lower esophageal sphincter (LES) remain controversial. This study was designed to investigate the effects of endogenous hypergastrinemia on lower esophageal sphincter pressure (LESP). Auto transplantation of the isolated vagally innervated antrum as a diverticulum into the transverse colon produces endogenous hypergastrinemia. Five dogs underwent measurement of fasting and postprandial LESP and serum gastrin (fasting LESP 43.2 ± 3.7 (SEM) cm H 2 O; fasting serum gastrin 21.9 ± 7.0 (SEM) pg/ml). Antral transplantation resulted in a marked increased in fasting serum gastrin (158.9 ± 35.5 (SEM) pg/ml) ( P 2 O) ( P > 0.2). The response of the sphincter to a protein stimulus was not altered by endogenous hypergastrinemia. This study provides the first concrete evidence that endogenous gastrin plays no significant role in the regulation of lower esophageal sphincter pressure.

Intussesception after jejunoileal bypass as diagnosed by ultrasound.

Eighty patients who had undergone jejunoileal bypass for morbid obesity were examined by ultrasound at their routine follow-up visits to the clinic. Ultrasonographic evidence of intestinal intussusception was found in 15 patients (19%). Two of these patients were asymptomatic. Ultrasonographic findings were confirmed by operation in 6 patients (5 with intussusception, 1 negative).