Role of neurocrine somatostatin on sphincter of Oddi contractility and intestinal ischemia reperfusion-induced acute pancreatitis in macaques

BACKGROUND

Intestinal ischemia-reperfusion (IIR) is implicated in the pathogenesis of severe acute pancreatitis (SAP). This study investigates the impact of neurocrine somatostatin (SST) on the contraction of sphincter of Oddi (SO) during IIR.

METHODS

Intestinal ischemia-reperfusion model in macaques was induced by occluding the superior mesenteric artery. Pancreatitis was confirmed by pancreatic histology and serum levels of amylase and lipase. SST and its receptors (SSTRs) in SO were visualized by immunohistochemistry. Effects of SST on the contraction of the isolated SO were recorded in vitro.

KEY RESULTS

Inflammatory scores of the pancreas and serum levels of amylase or lipase in the macaques that underwent IIR were significantly higher than those in the control group. The frequency and amplitude of phasic contraction of the circular muscle in SO was increased by SST in a concentration-dependent manner. Compared with the control group, SST innervation or SSTR2 expression in SO of macaques treated with IIR was increased 5.2 fold or 5.6 fold respectively. Prophylactic infusion of SST before IIR significantly reduced SST immunoreactive fibers in SO as compared to those in the IIR group and remarkably alleviated the pathophysiologic changes due to IIR.

CONCLUSIONS & INFERENCES

Increased SST innervation in SO during the early phase of IIR associated with the contraction of circular muscle of SO, which might be one of the promoting factors associated with the development of SAP. Prevention of IIR or intervention of SO contraction after occurrence of acute pancreatitis might be beneficial for preventing SAP.

The functional sphincter of Oddi disorder

The sphincter of Oddi disorder (SOD) has been a controversial subject for many years, about which a lot has been written. However, new findings mainly using Endoscopic Retrograde Cholangiopancreatography (ERCP) and sphincter of Oddi manometry (SOM) demonstrate the fact of this diagnostic. SOD is just a part of a larger pathology, the tfunctional gastrointestinal disorders, which have been reconsidered as an important part of gastrointestinal diseases. For a better understanding, the American Gastroenterology Association Institute created a new classification of The Functional Gastrointestinal Disorders in 2006, Rome III Classification, in which the SOD is grouped in the functional biliary disorders (category E). The term SOD is used to define manometric abnormalities in patients who have signs and symptoms consistent with a biliary or pancreatic ductal origin. Based on the pathogenic mechanism and manometry findings, the SOD is separated into two groups: a group characterized by a stenotic pattern (anatomical abnormality) and a second group with a dyskinetic pattern functional abnormality). The purpose of this article is to construct a short presentation of the main aspects regarding tfunctional SOD (E2 and E3 after Rome III Classificatio).

The sphincter of Oddi: understanding its control and function

The most common functional disorders of the biliary tract and pancreas are associated with disordered motility of the sphincter of Oddi (SO). The SO is a neuromuscular structure located at the junction of the bile and pancreatic ducts with the duodenum. The primary functions of the SO are to regulate the delivery of bile and pancreatic juice into the duodenum, and to prevent the reflux of duodenal contents into the biliary and pancreatic systems. Disordered motility of the SO leads to the common and painful clinical conditions of SO dysfunction and acute pancreatitis. In order to understand normal SO motility, studies have been performed addressing SO function, control of spontaneous SO activity, responses to bioactive agents, SO innervation, and reflexes with other gastrointestinal organs. These studies have led to the current understanding of how the SO functions and may permit the development of targeted therapy for SO dysfunction and acute pancreatitis. This review summarizes the current knowledge regarding the control and regulation of SO motility, highlighting laboratory based and clinical research performed over the last 5 years.

Benign anatomical mistakes: "ampulla of Vater" and "papilla of Vater"

The anatomy of the ampullary termination of the bile and pancreatic ducts is complex; appropriate terminology for this area is confusing and inaccurate. We examine the terms "ampulla of Vater" and "papilla of Vater" for anatomical and historical correctness. The term "ampulla" refers to a dilated part of a duct or other channel. Thus, this word is topographically correct to describe the dilatation at the confluence of the bile and main pancreatic ducts; historically, however, there is considerable reason to believe that its first description was by Santorini rather than Vater. The eponymous term "papilla of Vater" is also incorrect historically. The use of eponyms is firmly entrenched in the medical literature, but some are so problematic that they should be discarded. The eponymous terms for both the ampulla and the papilla should be replaced with the terms "hepatopancreatic ampulla" (or "biliaropancreatic ampulla") and "major [or "greater"] duodenal papilla," respectively.

Sphincter of Oddi dysfunction and other functional biliary disorders: evaluation and treatment

Functional biliary disorders encompass the conditions of SOD and gallbladder dysmotility, both of which result in clinical pain syndromes. Obtaining objective diagnostic and outcomes data for both disorders has been an ongoing challenge over the last two decades. SOD, although initially believed to be strictly a biliary disorder, has now been implicated in recurrent pancreatitis. The biliary-type classification allows a clinician to stratify patients who would benefit from SOM and endoscopic sphincterotomy. Further study into the impact of endoscopic therapy for recurrent pancreatitis is needed. By the same token, the dilemma of postcholecystectomy abdominal pain, whether classified as biliary or pancreatic type III, remains challenging. The current limitations of knowledge highlight the need for prospective randomized studies to evaluate the clinical significance of SOM abnormalities to facilitate treatment of these patients.

The study between the dynamics and the X-ray anatomy and regularizing effect of gallbladder on bile duct sphincter of the dog

AIM: To study the relationship between the radiological anatomy and the dynamics on bile duct sphincter in bile draining and regulatory effect of gallbladder.

METHODS: Sixteen healthy dogs weighing 18 kg to 25 kg were divided randomly into control group and experimental group (cholecystectomy group). Cineradiography, manometry with perfusion, to effect of endogenous cholecystokinin and change of ultrastructure were employed.

RESULTS: According to finding of the choledochography and manometry, in control group the intraluminal basal pressure of cephalic cyclic smooth muscle of choledochal sphincter cCS was 9.0 ± 2.0 mmHg and that of middle oblique smooth muscle of choledochal sphincter (mOS) was 16.8 ± 0.5 mmHg, the intraluminal basal pressure of cCS segment was obviously lower than that of mOS (P < 0.01) in the interval period of bile draining, but significant difference of intraluminal basal pressure of the mOS segment was not found between the interval period of bile draining (16.8 ± 0.5 mmHg) and the bile flowing period (15.9 ± 0.9 mmHg) (P > 0.05). The motility of cCS was mainly characterized by rhythmically concentric contraction, just as motility of cCS bile juice was pumped into the mOS segment in control group. And motility of mOS segment showed mainly diastolic and systolic activity of autonomically longitudinal peristalsis. There was spasmodic state in cCS and mOS segment and reaction to endogenous cholecystokinin was debased after cholecystectomy. The change of ultrastructure of cCS portion showed mainly that the myofilaments of cell line in derangement and mitochondria is swelling.

CONCLUSION: During fasting, the cCS portion has a function as similar cardiac "pump" and it is main primary power source in bile draining, and mOS segment serves mainly as secondary power in bile draining. The existence of the intact gallbladder is one of the important factors in guaranteeing the functional coordination between the cCS and mOS of bile duct sphincter. There is dysfunction in the cCS and mOS with cholecystectomy.

The relationship of bile duct crystals to sphincter of Oddi dysfunction

Bile duct crystals collected either from the duodenum after gallbladder contraction or directly from bile duct aspiration are surrogates for gallbladder stones and microlithiasis. Whether bile crystals also serve as surrogates for bile duct stones or microlithiasis that forms in the bile duct after cholecystectomy is not known based on current data. Sphincter of Oddi dysfunction (SOD), due either to muscular spasm or sphincter fibrosis, is a cause of bile duct obstruction. Almost all of the literature on SOD involves patients who have had a prior cholecystectomy. Intuitively, obstruction at the SO following cholecystectomy would seem to lead to biliary stasis and predispose patients to bile duct microlithiasis. However, a recent study did not find bile duct crystals in patients with manometrically diagnosed SOD. The reason for this is unknown, although we hypothesize that cholesterol and bilirubinate crystals are not surrogates for brown pigment stones commonly found in patients following cholecystectomy.

Sphincter of Oddi (pancreatic) hypertension and recurrent pancreatitis

Major papilla pancreatic sphincter dysfunction, a variant of sphincter of Oddi dysfunction, causes pancreatitis and pancreatic-type pain. The gold standard for diagnosis is sphincter of Oddi manometry, most commonly performed at endoscopic retrograde cholangiopancreatography (ERCP). Noninvasive testing, such as secretin-stimulated transabdominal or endoscopic ultrasound assessment of pancreatic duct diameter, is less reliable and has relatively low sensitivity. Two thirds of patients with biliary sphincter of Oddi dysfunction have elevated pancreatic basal sphincter pressure. To maximize the diagnostic yield of sphincter of Oddi dysfunction, both the biliary and pancreatic sphincter pressures should be measured. Patients with sphincter of Oddi dysfunction may respond to biliary sphincterotomy alone, but evaluation of their pancreatic sphincter is warranted if symptoms persist after biliary therapy alone. Whether both biliary and pancreatic sphincters should be treated at the first ERCP session is controversial. Biliary and pancreatic endoscopic sphincterotomies are associated with two- to fourfold increased incidence of pancreatitis following the procedure in patients with pancreatic sphincter hypertension. Prophylactic pancreatic duct stenting reduces the frequency and severity of complications by greater than 50%.

Morphometric study of the sphincter of oddi (hepatopancreatic) and configuration of the submucosal portion of the sphincteric muscle mass

The sphincter of Oddi (SO) hepatopancreatic sphincter from 114 Japanese adults, especially the sphincteric muscle mass lying in the duodenal mucosal layer (the submucosal portion of the SO: SMSO), was measured macroscopically under a binocular microscope. The SMSO was classified into two types according to shape. The horizontal type (95/114) usually displayed a rod-like shape (6.0 mm at average diameter at the root) directed toward the anus and was situated on the duodenal muscle wall with the papillary orifice at or near the tip (anal side) of the SMSO. The horizontal type SMSO followed the underlying muscle wall widely ranging from 5.0 mm to 17.9 mm length (9.8 mm at average) and was attached to the wall by the loose connective tissue along the entire length. In the horizontal type, the extramural portion (the portion penetrating and outside of duodenal muscle of the SO) of the SO was very small. The vertical type (19/114) erected on the muscle wall vertically into the lumen of the duodenum. The average length and average maximum diameter of the vertical type were 6.0 mm and 6.2 mm, respectively. The extramural portion of the SO was thicker and tighter in the vertical type, which suggested that endoscopic sphincterotomy might preserve the length of the SO longer than endoscopic papillary balloon dilation (EPBD). Of the individuals in our study, 18% (19/114) had SO diameters <5 mm, a finding that may have implications for selection of balloon size in EPBD.

Oddi sphincter and common channel: evaluation with pharmacodynamic MR cholangiopancreatography using fatty meal and secretin stimulation

PURPOSE

This study was performed to assess the usefulness of pharmacodynamic MR cholangiopancreatography (MRCP) in depicting the segment covered by the Oddi sphincter.

MATERIALS AND METHODS

Twelve volunteers were studied by pharmacodynamic MRCP. After stimulation by the oral intake of a fatty meal and an intravenous injection of secretin, a single-shot rapid acquisition relaxation enhancement (RARE) sequence was used to obtain consecutive images of the segment covered by the Oddi sphincter. The contraction range of the Oddi sphincter and the lengths of the common channel were measured on the MR console by comparing the most contracted image of the sphincter with the most relaxed image.

RESULTS

Pharmacodynamic MRCP showed periodic contraction of the Oddi sphincter in all cases. The range of sphincteric contraction over the biliary duct was 8-19 mm (11.8+/-3.2 mm, mean +/- standard deviation) and over the pancreatic duct 8-23 mm (10.0+/-1.5 mm). In 11 of the 12 cases, the common channel was depicted and its length ranged from 3-8 mm (5.2+/-1.3 mm).

CONCLUSION

Pharmacodynamic MRCP clearly depicted the range of contraction of the Oddi sphincter and the common channel, which are not usually revealed by conventional MRCP.

[The microsurgical anatomy of the major duodenal papilla and of the sphincter of the hepatopancreatic ampulla]

Morphometrical parameters of the anterior, posterior, superior and inferior walls of gastroduodenal passage have been investigated in 26 preparations. Three anatomical forms of the pyloric sphincter were distinguished. Histotopography of vessels and nerves in gastroduodenal passage and their distribution in the walls of the passage have been investigated.

Vector manometric study of the sphincter of Oddi in the dog: functional and morphological correlation

The relationship between sphincter of Oddi pressure and the morphological structure of the sphincter was studied in eight dogs prepared with a duodenal cannula. Sphincter of Oddi manometry was performed in awake animals in three directions, ventral, left dorsal, and right dorsal, using a catheter with three radial side holes for recording at one level. The pressure in the ventral direction (26.6+/-1.06 mmHg) (mean+/-SEM) was significantly lower than that in the left and right dorsal directions (30.6+/-1.42 and 31.2+/-1.23 mmHg, respectively). This functional manometric difference in the three directions correlated closely with the morphological structure of the sphincter of Oddi; the sum of the thickness of the sphincter of Oddi muscle and duodenal proper muscle was greater on the dorsal than on the ventral side. To our knowledge, this is the first report of axial asymmetry in sphincter of Oddi pressure.

Galanin modulates sphincter of Oddi function in the Australian brush-tailed possum

The neuropeptide galantin (GAL) is found in neurons in the biliary tract of several species. We mapped the distribution of GAL-like immunoreactive nerve (GAL-LI) fibers in the sphincter of Oddi of the Australian brush-tailed possum by immunohistochemistry. The pharmacological effects of GAL in vitro and in vivo were studied by measuring sphincter of Oddi muscle strip contractility and transsphincteric flow, respectively. Muscle layers, and ganglionated and perivascular plexuses, contained GAL-LI nerve fibers. Exogenous GAL caused a concentration-dependent (10(9)-10(-6)M) increase in the spontaneous longitudinal but not circular muscle contractions. At 10(-6) M GAL, contractile activity was elevated two- to fourfold. This response was tetrodotoxin insensitive but competitively inhibited by galantide (10(-8)-10(-7) M). In vivo, intra-arterial bolus injections of GAL (1001000 ng/kg), decreased transsphincteric flow, with a maximum reduction to 80.2 +/- 6.8% of control. In conclusion, GAL appears to selectively stimulate longitudinally oriented sphincter of Oddi smooth muscle via a direct mechanism, which results in a modest reduction in transsphincteric flow.

Sphincter of Oddi motility

BACKGROUND

Technical improvement in endoscopic and manometric technique has allowed direct manometry of the human sphincter of Oddi (SO). The aim of the present review is to describe the present status of physiologic and clinical knowledge of the SO, with emphasis on contributions from Danish Gastroenterology.

RESULTS

The SO is a zone with an elevated basal pressure with superimposed phasic contractions. It acts mainly as a resistor in the regulation of bile flow. Neurohormonal regulation influences the motility pattern. The contractions are under the control of slow waves. Clinical subgroups show abnormalcy in SO manometric pattern especially in patients with biliary or pancreatic pain without demonstrable organic substrate. Evidence suggests that endoscopic sphincterotomy may be of benefit in these patients.

Surgical anatomy of the papilla of Vater and biliopancreatic ducts

The present research was aimed at defining the surgical anatomy of the biliopancreatic ducts and of Oddi's sphincter. The numerous anatomic variations of the papilla, the millimetric distribution of its muscle fibres, and any morphological detail of clinical significance have been investigated. An integrated analysis of radiographic, tridimensional (casts), and histologic findings has been carried out in 49 of 64 autoptic bilio-duodenopancreatic specimens. Exact limits of the choledocus and Wirsung sphincters were defined. A consistent accumulation of circular muscle fibres could be seen, on the choledocus duct side, up to a mean distance of 13.6 mm from the papillary pore. However, more rarefied fibres were present up to 20.5 mm. Muscle fibres were seen to stop roughly on the pancreatic duct side at 7.3 mm from the papillary pore. The beginning of the sphincter was observed 2-3 mm above the papillary pore. There was no evidence suggesting the presence of upper, middle, and lower biliary sphincters. Five anatomic diversities of the Wirsung-choledocus confluence were found. The Y type was the most frequent (61.2%), followed by the U type (22.4%), V (14.3%), and II (2.1%). Santorini's duct with a normal papilla was present in 16 per cent of the cases. These data along with other interesting observations on antireflux mechanisms (Santorini's valves) and on the ductal space orientation appear to be useful guidelines for a physiopathological understanding of bilio-pancreatic diseases and for any therapeutic procedure on these structures.

Distribution and morphological features of nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) activity in intrinsic neurons of the Oddi sphincter of the cat

To clarify the role of nitric oxide (NO) in the sphincter of Oddi, we histochemically investigated the distribution of nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d), a marker for NO synthase, in the cat. NADPH-diaphorase activity was localized in two neuronal subtypes: large neurons with many dendrites and smaller with one process. Most of the nerve cell bodies (99%) in the wall of the sphincter of Oddi showed strong activity for this enzyme. The nerve fibers with NADPH-d activity were observed in all layers, chiefly in the muscle layers. These results suggest that NO may play a very important role in the neuronal regulation of sphincter of Oddi.

[Manometric study of the biliary sphincter zone: a comparison between the length of phasic activity and the narrow distal segment]

Motor activity of the sphincter of Oddi has been evaluated in 26 patients who underwent ERCP examination. Manometric recordings from the common bile duct and the sphincter of Oddi were performed with a single end-lumen perfused catheter. The number of successive 3 mm spaced black marks, observed during the pull-through from the first appearance of the proximal sphincter activity to that of duodenal pressure, was used to measure the length of the sphincter zone. In 14 of 26 patients, the length of phasic activity zone of the sphincter of Oddi was 9 mm. However, the narrow distal segment of the common bile duct was 15.1 +/- 3.6 mm in length. In same patients, the length of phasic activity zone was shorter than the anatomical one. The mean sphincter of Oddi pressure (SOP) at the distance of 6 mm from the papillary pore (77.8 +/- 22.1 mmHg) was greater than that of 9 mm (58.4 +/- 27.0 mmHg) and 12 mm (51.0 +/- 16.9 mmHg). These results suggest that the location of the orifice of catheter should be taken into consideration when comparing the SOP.

Physiology of motor function of the sphincter of Oddi

Human and experimental studies of the sphincter of Oddi have established that the sphincter is not a simple and passive smooth muscle portion of the biliary system; rather, it plays an active role in modulating bile flow into the duodenum in both the fasted and the postprandial states. The sphincter of Oddi in the opossum, and likely in man, demonstrates spontaneous phasic and perhaps peristaltic activity that affects bile flow into the duodenum. The sphincter appears to be under the control of a smooth muscle pacemaking-like region in the proximal sphincter that controls the frequency and direction of propagation of the phasic contractions. Immunohistochemical studies have documented the presence of dense concentrations of neuropeptide-containing myenteric nerves in the sphincter of Oddi. Physiologic studies have confirmed that these peptides, in combination with the classic gastrointestinal hormones, exert significant effects on biliary motility. Experimental studies of the motor physiology of the sphincter of Oddi have advanced our understanding of human biliary motility and dysmotility. A subset of patients experiences biliary-like pain after cholecystectomy. This pain may be attributable to either mechanical stenosis of the papilla or dysfunction of the sphincter of Oddi. No definitive test currently exists to establish the diagnosis with adequate sensitivity or specificity. It is hoped that further development of ultrasonographic, scintigraphic, manometric, or electromyographic techniques will allow a clearer definition of patients who truly have sphincter dysfunction and who might benefit from medical, endoscopic, or surgical therapy.

Anatomy of the bilioduodenal junction of the opossum

Prevention of reflux is a major function of the terminal biliary duct system at its junction with the duodenum. We examined this area via scanning electron microscopy and light microscopy to explore anatomic features that might play such a role in the Virginia opossum, a species with a highly developed sphincter of Oddi (SO). The terminal apparatus, most of which consists of a dilated extramural ampulla, has a lumen with abundant folds. Mucus is produced by the lining epithelium and by a plethora of glands. Three muscle layers constitute the SO: an inner longitudinal, an outer circular, and a less consistent outermost longitudinal. The terminal apparatus forms an acute angle and narrows as it enters the duodenum; at this point, the SO becomes continuous with the muscularis externa of the intestine. Four anatomical features with potential antireflux properties may be identified: mucus production, luminal folds, and the narrow opening and oblique course of the intramural duct.

In vitro measurement of the length of the sphincter of Oddi

A study to determine the length of the sphincter of Oddi was performed using 148 autopsy specimens with adjacent structures obtained from adults. The median diameter of the common bile duct was 7 mm (range 4-13 mm). The median intramural length of the sphincter measured at gross examination of 75 specimens was 14 mm (range 7-22 mm); the median length of the common channel between the common bile and pancreatic ducts was 3 mm (range 0-9 mm). Longitudinal histological preparations for microscopic examination were made of 73 specimens. The median extramural length of the sphincter was 5 mm (range 1-11 mm). No associations were found between the length of the sphincter, intramural or extramural, and the diameter of the common bile duct, age, sex, presence of stones in the gallbladder or the postcholecystectomy state, nor was there an association between the intramural and extramural length of the sphincter (p greater than 0.05).

Motor pattern of the sphincter of Oddi in patients with juxtapapillary diverticula

In 15 patients with duodenal diverticula close to the papilla of Vater we evaluated the motor activity of the sphincter of Oddi by endoscopic biliary manometry. Both basal pressure and phasic activity were similar to those in nine patients without biliopancreatic disease and in 60 patients with common bile duct stones. The anatomical relationship between the papilla and diverticula did not lead to any change in the motor pattern. If juxtapapillary diverticula are associated with a higher prevalence of biliopancreatic disease, dysfunction of the sphincter of Oddi does not seem to play a pathogenic role.

Functional and morphological relationships between the feline main pancreatic and bile duct sphincters

To analyze the relationships between the bile duct and main pancreatic duct sphincters, the resistance to flow through these sphincters was studied simultaneously with perfusion techniques in anesthetized cats. Basal flow resistance was higher in the pancreatic sphincter than in the bile duct sphincter. The pressure in one duct system was not affected by the flow in the other. The muscular activities in the sphincters were usually well coordinated. Distention of the upper biliary tract or the pancreatic duct system reduced the flow resistance in both sphincters. Cholecystokinin-8 (0.01 micrograms), duodenal distention, and sublingual glyceryl trinitrate (0.4 mg) also relaxed both sphincters, whereas secretin in a dose that induced pancreatic secretion had no consistent effect. Morphine increased flow resistance in both systems. These functional studies indicate that the 2 sphincters share smooth muscle fibers at the level where the flow resistances arise, and there are thus no grounds for separate control of the sphincters. There was no evidence of a functionally common sphincter ampulla. The conclusions drawn from the manometric results were supported by morphological findings in this study.

Manometric measurement of human sphincter of Oddi length

Length of biliary (CBD) and/or pancreatic (PD) sphincter of Oddi (SO) was measured during perendoscopic or intraoperative manometry in 21 control subjects and in 46 patients with biliary disease. When the high resting pressure (HPZ) and the phasic wave zone (PAZ) were considered, SO length was, in the control group, 9.5 +/- 0.5 mm (M +/- SE) and 9.4 +/- 0.6 mm at the level of the CBD-SO, and 7.7 +/- 0.6 mm and 6.9 +/- 0.5 mm at the level of the PD-SO. The physiological sphincter length appeared substantially shorter than the anatomical one, as reported in the literature. No significant differences were found between controls and patients with CBD stones. Endoscopic sphincterotomy without manometry reduced mean sphincter length length of the sphincterotomy was tailored to the manometric findings. Surgical partial sphincterotomy reduced sphincter length by only 46.7 +/- 10.3%.

Certain aspects of normal and abnormal motility of sphincter of Oddi

Applications of electromyographic and endoscopic manometric techniques in experimental and clinical studies have enhanced our knowledge of the normal physiology and motility disturbances of the sphincter of Oddi. The sphincter of Oddi has an active role in coordinating the time and rate of secretion of biliopancreatic juice into the duodenum. In the opossum, the sphincter of Oddi exhibits spontaneous contractions that migrate distally along the sphincter and expels its contents into the duodenum. Although the motor activity of the sphincter of Oddi is independent from that of the duodenum, there is a correlation between the frequency of bursts of spike potentials in the sphincter of Oddi and the migrating motor complex phases in the duodenum. Abnormal motility of the sphincter of Oddi has been reported during endoscopic manometric evaluation of patients with choledocholithiasis and sphincter of Oddi dyskinesia. Patients with common bile duct stones have an increase in the frequency of retrograde propagation of phasic waves. Elevation of basal pressure as well as an increase in the frequency and amplitude of sphincter of Oddi phasic waves and the common bile duct-duodenum gradient pressure may occur in patients with sphincter of Oddi dyskinesia. Endoscopic manometric studies of the sphincter of Oddi may become an important method to diagnose sphincter of Oddi dyskinesia.

The significance of the diameter of the common bile duct in cholecystectomized patients

In the cholecystectomized patients there is no correlation between the diameter of the common bile duct and the pressure in the biliary system or in the sphincter of Oddi. It is most probably due to unresolved dilatation of the common bile duct. ERCP manometry is probably a more accurate technique for establishing the diagnosis of papillary stenosis in patients who had their gallbladder removed.

Motor function of the opossum sphincter of Oddi

We studied the opossum sphincter of Oddi (SO) because in this species the SO is approximately 3 cm in length and its extraduodenal location permits recording of motor activity with negligible interference from duodenal motor activity. The SO segment of 120 animals was evaluated by one or more of the following: (a) intraluminal manometry; (b) electromyography; (c) common bile duct (CBD) flow monitored by a drop counter; (d) cineradiography of intraductal contrast medium; and (e) histologic examination. SO pull-throughs using an infused catheter of 0.6-mm o.d. invariably showed a high pressure zone (HPZ) of 18 +/- 3 SE mm Hg in the terminal 4-5 mm of the SO segment. This HPZ had a narrow lumen, 0.5-0.7 mm in diam, and prominent circular muscle. The HPZ in the terminal SO had both active and passive components. HPZ with minimal amplitude and a paucity of underlying smooth muscle were present inconstantly at the junction of the SO segment with the CBD and pancreatic duct, respectively. The dominant feature of the SO segment was rhythmic peristaltic contractions that originated in the proximal SO and propagated toward the duodenum. These contractions occurred spontaneously at a rate of 2-8/min, ranged up to 200 mm Hg in magnitude, had a duration of approximately 5 s and were not abolished by tetrodotoxin. Concurrent myoelectric and manometric recordings showed that each phasic contraction was immediately preceded by an electrical spike burst. Simultaneous recordings of cineradiography, CBD inflow of contrast medium, SO manometry, and SO electromyography indicated that rhythmic peristaltic contractions stripped contrast medium from the SO into the duodenum. During SO systole, CBD emptying was transiently interrupted, whereas SO filling occurred during the diastolic interval between SO peristaltic contractions. SO distention increased the frequency of SO peristalsis. We conclude that (a) the dominant feature of the opossum SO is rhythmic peristaltic contractions that originate in the proximal SO and propagate toward the duodenum; (b) these forceful SO peristaltic contractions are myogenic in origin and serve as a peristaltic pump that actively empties the SO segment; (c) CBD outflow occurs passively during SO diastole, but is interrupted transiently during each SO peristaltic contraction; and (d) a short HPZ with active as well as passive components exists in the distal SO segment and acts as a variable resistor to SO outflow.

[Pressure-diameter-relationship of the papilla duodeni. An experimental study (author's transl)]

While extending the papilla duodeni of dogs by probes of increasing diameter, mural pressure was measured as an equilibration of the hydrostatic pressure within the probes along a distance of 12 mm. Pressure-diameter-curves at the duodenal end of the papilla show the mural pressure promptly increasing to a maximum when partially extended, then declining and rising again when extended extremely. Proximal to the papillary end the mural pressure first declines and then continuously increases with larger probe diameters. The pressure-diameter-curve of the papillary end resembles the length-tension-diagram of isolated smooth muscle in vitro, and represents the normal physiological action of the sphincter zone.

[Surgical anatomy of the terminal choledochus]

On the basis of data from the literature, as well as on his personal experience, the author defines a series of notions concerning the structural particularities of the terminal choledocus, highly interesting from the surgical view point. It is shown that at this level a valve exists, with a special structure, as well as a complex sphincteral system, highly refined in its functions, that should be carefully preserved, within the possibilities of techniques applied during surgical interventions.

A clinical and anatomical study of anomalous terminations of the common bile duct into the duodenum

Termination of the common bile duct into the duodenum was studied in 1000 patients by operative cholangiograms obtained from 5 different San Francisco Bay Area hospitals. The results indicate the strong probability that the duodenal biliary papilla is anomalously placed in at least 13% of the 1000 patients studied. Comments relative to the importance of this fact to surgeons and radiologists are made, and suggestion of a possible causative factor for the anomalies is proposed.

[An experimental study on the mechanism of bile excretion of the choledochoduodenal junction (author's transl)]

The present study was undertaken to elucidate the mechanism of bile excretion of the choledochoduodenal junction (ch-d junction) in rabbits, especially regarding it's structural and physiological independence from the duodenum. For this purpose muscular anatomy of the ch-d junction and relationship between the electromygoraphic spike potential of the juncture and the intracholedochal pressure were investigated. 1. There were demonstrated proper circular muscle and proper oblique muscle in the ch-d junction, which appeared independent from the duodenal muscle. There existed A MUSCULAR SPHINCTER at the terminus of the common bile duct, but it's muscle fibers did not appear continuous with the duodenal muscle fibers. 2. The rhythmical changing curve of the intracholedochal pressure was parallel with appearance of the spike potential but had absolutely no correlation with the duodenal one. 3. The attitudes of the ch-d junction and the duodenum to the neural control were compared. The spike generation by Neostigmin METHYLSULFATE WAS EQUALLY OBSERVED IN THE CH-D JUNCTION and the duodenum and the spike inhibition by Hyoscin-N-butylbromide was also equally observed in both of them, SUGGESTING THEIR innervation was probably common.