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Biomedical subjects

L M Nyhus

Publications and source records attributed to L M Nyhus.

At least 55 records · Page 3Linked to original sources
PubMed1987

Distinction of lower esophageal sphincter strength from sphincter competence.

Although an absolute correlation has been impossible to demonstrate, it has long been thought that the manometric magnitude of the lower esophageal sphincter pressure was a good index of lower esophageal sphincter strength, and hence its competence. To study this relationship, 12 adult mongrel cats were surgically fitted with gastric cannulas. The cats were studied by six-lumen, radially-oriented, rapid pullback manometry before and after administration of atropine, and before and after daily perfusion of the distal esophagus with 0.1 N hydrochloric acid. Lower esophageal sphincter strength was determined by the lower esophageal sphincter pressure vector cross-sectional area. This was computed by plotting the lower esophageal sphincter pressure on polar coordinates, and finding the area circumscribed by the vectors. Lower esophageal sphincter competence was determined by measurement of both the intragastric volume and intragastric pressure required to produce gross reflux. Atropine significantly decreased the mean lower esophageal sphincter pressure vector cross-sectional area from 7,963 +/- 2,469 mm Hg to 720 +/- 59 mm Hg (p less than 0.05) and decreased the mean lower esophageal sphincter opening pressure from 30.2 +/- 6.9 mm Hg to 13.2 +/- 4.1 mm Hg (p less than 0.05). However, acid perfusion significantly decreased the lower esophageal sphincter pressure vector cross-sectional area from 6,786 +/- 3,334 mm Hg to 715 +/- 720 mm Hg (p less than 0.05). This indicates that the lower esophageal sphincter has two components, one of which is acid-sensitive and both of which are atropine-sensitive.

Animals↗
PubMed1987

Endoscopic Congo red test during proximal gastric vagotomy.

Although proximal gastric vagotomy is widely performed as an elective treatment for duodenal ulcer, the incidence of recurrent ulcer is troublesome. There are several theories to explain recurrent ulcers, and important technical steps should be considered when performing proximal gastric vagotomy. The use of an intraoperative test may allow more accurate performance of the operation and more complete vagotomy of the parietal cell mass. This report describes the use of the endoscopic Congo red test in patients during proximal gastric vagotomy. The test allows rapid and accurate mapping of areas of the stomach with intact vagus and secretory nerves after operative vagotomy, and can be repeated several times if necessary to verify completion of the vagotomy. The use of universally available equipment and the potential for intraoperative and postoperative use are other attractive features of the test. Use of the endoscopic Congo red test provides physiologic evidence that vagus secretory nerve fibers traverse the right and left gastroepiploic nerves, leading us to believe that the gastroepiploic nerves should be routinely divided during proximal gastric vagotomy. In patients with recurrent duodenal ulcer requiring reoperation, the endoscopic Congo red test allows preoperative demonstration of the site of the intact vagal nerve trunks. The endoscopic Congo red test deserves further investigation and wider application during operations for chronic duodenal ulcer.

Congo Red↗
PubMed1987

Can the use of an endoscopic Congo red test decrease the incidence of incomplete proximal gastric vagotomy?

The endoscopic Congo red test allows accurate and rapid evaluation of the completeness of vagotomy and may result in a lower incidence of postoperative incomplete vagotomy. This report describes 44 patients tested during proximal gastric vagotomy. Evidence of incomplete vagotomy was found in over 95% at the conclusion of the conventional operation. Importantly, the test was a guide to further operative maneuvers which abolished the evidence of incomplete vagotomy upon subsequent testing. The endoscopic Congo red test satisfies the requirements for an ideal test for complete vagotomy: it is easily performed, does not require special equipment, and can be repeated several times if necessary to verify that desired effects have been achieved. The wider use of this test, therefore, appears justified.

Congo Red↗
PubMed1987

Computerized axial manometry of the esophagus. A new method for the assessment of antireflux operations.

This is a presentation of a new manometric parameter of the mechanical competence of the lower esophageal sphincter (LES), the lower esophageal sphincter vector volume (LESVV). It is determined by computer analysis of continuous-pressure measurements during constant speed pullback of a radially oriented 4- 6- or 8-channel manometry catheter across the LES. Patients were studied with this method both before aggressive medical therapy for esophagitis and before and after Nissen fundoplication. LESVV accurately predicted failure of medical therapy and success of the fundoplication. In patients with successful fundoplication, LESVV demonstrated a 100-fold increase in mechanical competence of the LES, even in the absence of increased LES pressure or length, increasing from 113 +/- 63 mm3 to 11357 +/- 3733 mm3.

Esophagitis, Peptic↗
PubMed1987

Hemobilia: review of recent experience with a worldwide problem.

Between 1981 and 1985, the reported incidence of hemobilia increased for two major reasons. First, a more sophisticated and better-trained medical community could entertain the diagnosis readily in certain settings and had broader access to diagnostic methods that precisely defined the source of bleeding into the biliary tract. Second, there was wider use of percutaneous techniques of diagnosis and treatment of biliary diseases. Once the diagnosis of hemobilia was made by endoscopic or arteriographic means, physicians and surgeons were quicker to institute proper therapeutic measures. For this reason, the mortality associated with hemobilia decreased compared with that reported earlier. The medical community must be aware that modern treatments are now the most common cause of this problem. Since invasive diagnostic methods are increasingly used by nonsurgeons, it is imperative that these patients are studied in the context of complete consultation with surgeons who can use definitive treatments when required.

Abdominal Injuries↗
PubMed1987

Experience with the endoscopic test for completeness of vagotomy. Results of application in two medical centers.

The need for a practicable and reliable test for completeness of vagotomy has been previously recognized. Until recently, all of the tests for completeness of vagotomy required cumbersome or delicate equipment or had deficiencies which prevented routine use. Recently we have modified the endoscopic Congo red test (ECRT) to allow more rapid and accurate performance; furthermore, we have found that the routine use of this test has affected the performance of proximal gastric vagotomy in our medical centers. At this time, we report the application of the ECRT in 41 patients at two medical centers, including patients from the University of Illinois at Chicago and the University of Marburg. The SIMPLIFIED ECRT, which is completed in less than five minutes, avoids the 15-20 minute delay required with other tests for complete vagotomy; it is the only test for complete vagotomy which can be performed intra- and postoperatively. To our knowledge, the test has not been performed previously in Europe. The similarity of results following ECRT in both settings reinforces our view that intraoperative testing affects the performance of vagotomy, and is useful in teaching aspects of operative vagotomy. The endoscopic test appears to be the test of choice for determining completeness of vagotomy.

Congo Red↗
PubMed1986

Influence of maturation on activity-stress related pathology in the rat colon.

In the rat, activity-stress (A-S) treatment was related to varying degrees of inflammation, goblet depletion, and erosion of the mucosal wall. Young (aged twenty-eight days), and mature (aged seventy days), rats did not differ significantly in terms of overall thinning of the colon wall, however the incidence of hematuria, hemorrhage at fecal bolus sites, mucosal hyperemia and interstitial compression of the mucosal wall was greater for younger animals. These findings suggest that A-S produces both more severe and more acute colonic pathology in young animals. The use of the A-S paradigm as an appropriate route for inducing psychological stress is discussed in terms of its capacity to evoke a somatic stress response as indicated by stereotypical alterations of structure and function of the gastrointestinal and thymicolymphatic system.

Age Factors↗
PubMed1986

Achalasia of the esophagus. Treatment controversies and the method of choice.

During a 15-year period, 62 patients were treated for achalasia of the esophagus. Pneumatic dilation (PD) had been performed initially in 46 and was successful in 23; failures were due to acute perforation of the esophagus, persistent dysphagia, or pathologic gastroesophageal reflux. Esophagomyotomy alone (EM) was performed in 19 individuals resulting in definite improvement in 12; four patients had moderate reflux or dysphagia, and three of these required another surgical procedure. An extended myotomy with an antireflux procedure (M-NF) was performed in 13 patients with symptomatic relief in 12; one patient required reconstruction of a too-tight fundoplication that caused persistent dysphagia. The advantages of pneumatic dilation were the ease of performance, patient acceptability, and an overall efficacy of 50%. Definitive surgical therapy, while more predictably effective in relieving dysphagia, was considerably more expensive in terms of patient discomfort and time. When pathologic reflux was present following a previous procedure, the M-NF was performed; obstruction of the esophagus did not occur if the fundoplication was "floppy." The M-NF deserves consideration as the surgical procedure of choice for achalasia.

Acute Disease↗
PubMed1986

Effect of chemical sympathectomy with oxidopamine on systemic blood flow in rats with acute pancreatitis.

In response to previous demonstrations that either surgical or chemical sympathectomy can ameliorate the severity of acute experimental pancreatitis, and suggestions that the benefits of sympathectomy are related to alterations in the absolute blood flow or the pattern of blood flow within the pancreas or splanchnic organs, we studied blood flow in rats with acute deoxycholate pancreatitis. The animals had preliminary chemical sympathectomy with a false neurotransmitter (oxidopamine) prior to the experiment and were studied for 120 min after the onset of pancreatitis. All animals with pancreatitis had a fall in cardiac output by 120 min but maintained blood flow to the heart and brain by increasing the percent of cardiac output to these organs. Despite a 61% decrease in cardiac output, at 120 min the chemical sympathectomy group showed an increase in the percentage of flow within the pancreas. However, there was no change in the absolute organ blood flow in any group except at the 10 min measurement, when the pancreata showed an absolute increase in all groups. This study does not support the concept that chemical sympathectomy is beneficial in acute pancreatitis but does indicate a specific and possibly beneficial effect on the distribution of pancreatic blood flow. The decreased cardiac output after chemical sympathectomy is a clear disadvantage of this mode of treatment and probably disqualifies systemic chemical sympathectomy as a treatment consideration.

Acute Disease↗
PubMed1986

The life of Carl Beck and an important interval with Alexis Carrel.

Carl Beck was a surgeon associated with the University of Illinois College of Medicine between 1898 and 1917. With Alexis Carrel, Beck developed an operation that used the stomach for replacement of the esophagus. Beck had an illustrious career and a close personal and professional relationship with Carrel.

General Surgery↗
PubMed1986

Preservation of lower esophageal sphincter asymmetry after acid-induced abolition of the high pressure zone.

Over a decade ago acid abolition of the esophageal high-pressure zone in the cat was described. This finding was inconsistent with other studies demonstrating that the esophagus was impermeable to acid. Because this finding had been used to support the hypothesis of a "vicious circle" in the course of esophagitis, this phenomenon was re-studied in the cat. In ten animals, acid irrigation of the esophagus caused both esophagitis and transient reduction in lower esophageal sphincter (LES) manometric pressures. Despite the reduction in pressures, manometric asymmetry of the LES was preserved and the esophagitis promptly resolved when acid irrigation was stopped. We therefore conclude that although LES pressure may be abolished, this alone is insufficient to produce reflux and esophagitis over the long term. Preservation of asymmetry implies that the multiple exogenous components composing the LES may not be damaged by this insult.

Animals↗
PubMed1986

Characterization of a C-kinase inhibitory fraction.

A broad area of C-kinase inhibitory activity was detected after DEAE-cellulose chromatography of 20,000 g supernatant of rat stomach homogenate. Attempts to characterize the inhibitory moiety indicated that it was a non-protein, low molecular weight substance which eluted immediately after C-kinase activity. Similar inhibition was observed in the presence of KC1, the salt used in the elution buffer. Several other salts examined also displayed inhibition of C-kinase activity. Kinetic analysis showed that both KC1 and the inhibitor displayed competitive inhibition of histones and gave identical inhibitor constants.

Adenosine Triphosphate↗
PubMed1986

Establishing a flexible sigmoidoscopy/colonoscopy program for surgical residents. The University of Illinois experience.

The clinical value of lower gastrointestinal endoscopy and the requirement of the American Board of Surgery for endoscopic training mandate establishing a program in flexible sigmoidoscopy and colonoscopy for all surgical residents. In a 12-month period, the surgical residents at the authors' institution performed 599 flexible sigmoidoscopic and 116 total colonoscopic examinations under the supervision of two attending colorectal surgeons, with no mortality and a 0.03 per cent morbidity. There was an average of 42 endoscopic examinations per resident for the 3-week training period. Three hundred seventy (62%) of the flexible sigmoidoscopic examinations were for screening and 229 (38%) were for the evaluation of symptomatic patients. Colorectal polyps were identified in 68 patients (11.4%) and carcinoma in 14 patients (1.9%). Forty-nine per cent of the colonoscopic examinations were for endoscopic polypectomy. Sixty-four per cent of patients with more than one adenomatous polyp harbored polyps in different surgical segments of the colon. Every resident was able to perform flexible sigmoidoscopy safely by the end of the 3-week training period, and in addition, the residents rated their endoscopic experience as a valuable part of their surgical training.

Colonoscopy↗
PubMed1985

The floppy Nissen fundoplication. Effective long-term control of pathologic reflux.

In 1976 we defined a technique of "floppy" Nissen fundoplication (FNF) that prevented experimental pathologic reflux without preventing gaseous eructations or vomiting (normal reflux) when appropriate. This report describes the one- to eight-year follow-up of the 77 patients operated on since that time. The FNF has been completely effective in preventing pathologic reflux in 75 of 77 patients and has been partially effective in two others who are now subjectively asymptomatic. Adverse side effects were reported by two patients, one with gas-bloat and one with inability to belch or vomit. The lower esophageal sphincter pressure of patients postoperatively was increased to low normal values from a mean of 8.94 +/- 1.66 to 14.31 +/- 0.7 mm Hg (normal, 21.2 +/- 4.2 mm Hg). Since FNF does not cause greatly increased lower esophageal sphincter pressure, the inference that the FNF prevents reflux by altering the physiology of a reflux event is supported. In conclusion, the floppy fundoplication has been an effective operation with a low incidence of adverse side effects and without a tendency for late failure.

Adult↗