Direct neuronal interactions between the duodenum and the sphincter of Oddi

Paradoxical Stimulatory Response of Remanent Sphincter of Oddi to Buscapina After Endoscopic Sphincterotomy

Background/Aims

Endoscopic removal of bile duct stones has become the treatment of choice, which includes endoscopic sphincterotomy (EST) in the majority of cases, destroying at least partially the Oddi sphincter (OS). Loss of sphincter function in variable grade has been described, but changes in innervation are not known.

Methods

Endoscopic manometry of OS was performed in 14 patients after EST with specialized perfused catheter. Pressure values were registered before and after 10 mg Buscapina injected intravenously.

Results

Choledocho-duodenal pressure gradient was absent in all of 14 patients. Basal OS pressure was zero in 7 and conserved in normal range in the remaining 7. Phasic motor activity was registered in 11 patients and was absent in 3 patients. After 10 mg Buscapina intravenous injection, instead of habitual inhibition, increase in basal OS pressure and in frequency of phasic contractions was observed in 9 patients. This response was not related to age of patients, neither with time elapsed between the EST and manometry, nor the estimated size of papillotomy orifice. Duodenal peristalsis was invariably inhibited in all patients.

Conclusions

EST destroys not only the smooth muscle of OS, also alters the innervation interrupting the duodeno-sphincteric nerve circuit. This finding questions the use of Buscapina or other anticholinergic agent as spasmolytic in patients after EST.

Innervation of Extrahepatic Biliary Tract, With Special Reference to the Direct Bidirectional Neural Connections of the Gall Bladder, Sphincter of Oddi and Duodenum in Suncus murinus, in Whole-Mount Immunohistochemical Study

Sphincter of Oddi dysfunction is one of the most important symptoms in post-cholecystectomy syndrome. Using either electrical or mechanical stimulation and retrogradely transported neuronal dyes, it has been demonstrated that there are direct neural pathways connecting gall bladder and the sphincter of Oddi in the Australian opossum and the golden hamster. In the present study, we employed whole-mount immunohistochemistry staining to observe and verify that there are two different plexuses of the extrahepatic biliary tract in Suncus murinus. One, named Pathway One, showed a fine, irregular but dense network plexus that ran adhesively and resided on/in the extrahepatic biliary tract wall, and the plexus extended into the intrahepatic area. On the other hand, named Pathway Two, exhibiting simple, thicker and straight neural bundles, ran parallel to the surface of the extrahepatic biliary tract and passed between the gall bladder and duodenum, but did not give off any branches to the liver. Pathway Two was considered to involve direct bidirectional neural connections between the duodenum and the biliary tract system. For the first time, morphologically, we demonstrated direct neural connections between gall bladder and duodenum in S. murinus. Malfunction of the sphincter of Oddi may be caused by injury of the direct neural pathways between gall bladder and duodenum by cholecystectomy. From the viewpoint of preserving the function of the major duodenal papilla and common bile duct, we emphasize the importance of avoiding kocherization of the common bile duct so as to preserve the direct neural connections between gall bladder and sphincter of Oddi.

Association of acute pancreatitis or high level of serum pancreatic enzymes in patients with acute spinal cord injury: a prospective study

BACKGROUND

Spinal cord injuries has increased together with urban violence and show a high rates of incidence. Besides the onus to patient and society, it can also cause other serious complications to victims. Acute pancreatitis has an important impact on this disease and has been underdiagnosed in several patients.

OBJECTIVES

The aim of this study was investigate the association of acute pancreatitis in acute spinal cord injuries. The secondary aim was to propose an investigation protocol to early diagnose and prevent it.

METHODS

A prospective observational study was conducted in 78 patients who presented acute spinal cord injury (SCI) at our emergency department, confirmed by clinical and imaging examination, in according to the American Spinal Injury Association (ASIA) Classification. Exclusion criteria were chronic or associate diseases in spinal cord, pancreatic direct trauma, alcoholism and chronic pancreatic disease.

RESULTS

The association of acute pancreatitis in patients with SCI was 11.53%. The occurrence of pancreatitis or high levels of serum pancreatic enzymes in patients with ASIA A was 41.7% and only 4.17% in patients with ASIA E. In all, 55.2% of patients who presented pancreatitis or high levels of serum pancreatic enzymes had cervical level of SCI and 34.5% had thoracic level. Adynamic ileus was observed in 68.96% of this group.

CONCLUSION

We concluded that, in acute spinal cord injuries, the occurrence of acute pancreatitis or high serum levels of pancreatic enzymes are more frequent in patients with ASIA A Classification, cervical/thoracic level of spinal injury and adynamic ileus.

Collateral projections of the dorsal motor nucleus of the vagus nerve to the stomach and the intestines in the rat

The vagal motor neurons project to the gastrointestinal tract by way of the gastric, celiac and hepatic branches of the vagus trunk. We have examined whether single neurons in the dorsal motor nucleus of the vagus nerve (DMV) have collateral projections to the stomach, the duodenum and the intestines using a double-labeling tracing method. Following application of Fluorogold to the cut end of the accessory celiac branch and injection of cholera toxin subunit b (CTb) into the body of stomach, many Fluorogold- and CTb-labeled neurons were found throughout the DMV. Most CTb-labeled neurons (about 90%) were also labeled with Fluorogold. When Fluorogold was applied to the cut end of the accessory celiac or the gastric branch and CTb was injected into the duodenum, many Fluorogold-labeled neurons and CTb-labeled neurons were found in the DMV. About 20% of CTb-labeled neurons were also labeled with Fluorogold. These results indicate that many neurons in the DMV send collateral projections to both the stomach and the intestines innervated by way of the celiac branch. However, many neurons in the DMV projecting to the duodenum do not project to the stomach or the intestines caudal to the duodenum.

Cholecystectomy and clinical presentations of gastroparesis

BACKGROUND

Many patients with gastroparesis have had their gallbladders removed.

AIM

To determine if clinical presentations of patients with gastroparesis differ in those with prior cholecystectomy compared to patients who have not had their gallbladder removed.

METHODS

Gastroparetic patients were prospectively enrolled in the NIDDK Gastroparesis Registry. Detailed history and physical examinations were performed; patients filled out questionnaires including patient assessment of GI symptoms.

RESULTS

Of 391 subjects with diabetic or idiopathic gastroparesis (IG), 142 (36 %) had a prior cholecystectomy at the time of enrollment. Patients with prior cholecystectomy were more often female, older, married, and overweight or obese. Cholecystectomy had been performed in 27/59 (46 %) of T2DM compared to 19/78 (24 %) T1DM and 96/254 IG (38 %) (p = 0.03). Patients with cholecystectomy had more comorbidities, particularly chronic fatigue syndrome, fibromyalgia, depression, and anxiety. Postcholecystectomy gastroparesis patients had increased health care utilization, and had a worse quality of life. Independent characteristics associated with prior cholecystectomy included insidious onset (OR = 2.06; p = 0.01), more comorbidities (OR = 1.26; p < 0.001), less severe gastric retention (OR(severe) = 0.68; overall p = 0.03) and more severe symptoms of retching (OR = 1.19; p = 0.02) and upper abdominal pain (OR = 1.21; p = 0.02), less severe constipation symptoms (OR = 0.84; p = 0.02), and not classified as having irritable bowel syndrome (OR = 0.51; p = 0.02). Etiology was not independently associated with a prior cholecystectomy.

CONCLUSIONS

Symptom profiles in patients with and without cholecystectomy differ: postcholecystectomy gastroparesis patients had more severe upper abdominal pain and retching and less severe constipation. These data suggest that prior cholecystectomy is associated with selected manifestations of gastroparesis.

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.

A new mechanism for diverticular diseases: aging-related vagal withdrawal

It is widely believed that diverticulosis, a common condition among the elderly, results from repeated colonic barotrauma related to low dietary fiber and low stool bulk. Recent evidence has challenged the dietary-barotrauma hypothesis. We propose an alternative hypothesis that diverticulosis may be attributable to colonic smooth muscle dysfunction that results from vagal attrition associated with aging. We previously proposed that broad aging-related attrition of autonomic nerves may unmask intrinsic sympathetic bias of end-organs, leading to the compendium of familiar conditions associated with senility. Unexplained cholinergic hypersensitivity and receptor over-expression in bowel affected by diverticulosis have recently been observed. These findings are highly suggestive of a compensatory response to loss of vagal innervation. The resulting autonomic dysregulation may induce bowel smooth muscle dysfunction, setting the stage for diverticula formation. Thus, diverticular bowel disease may be a manifestation of the aging-related systemic vagal withdrawal. The framework may extend to diverticula formation in other parts of the gastrointestinal and genitourinary tracts. For instance, aging-related vagal attrition may represent the common upstream mechanism that induces both sphincter of Oddi dysfunction and peri-ampullary duodenal diverticula, conditions that frequently occur together. Novel approaches to preventing and treating diverticular diseases by promoting vagal activity are proposed including the electrical or pharmacologic modulation of the autonomic system.

Innervation of the extrahepatic biliary tract

The extrahepatic biliary tract is innervated by dense networks of extrinsic and intrinsic nerves that regulates smooth muscle tone and epithelial cell function of extrahepatic biliary tree. Although these ganglia are derived from the same set of precursor neural crest cells that colonize the gut, they exhibit structural, neurochemical, and physiological characteristics that are distinct from the neurons of the enteric nervous system. Gallbladder neurons are relatively inexcitable, and their output is driven by vagal inputs and modulated by hormones, peptides released from sensory fibers, and inflammatory mediators. Gallbladder neurons are cholinergic and they can express a number of other neural active compounds, including substance P, galanin, nitric oxide, and vasoactive intestinal peptide. Sphincter of Oddi (SO) ganglia, which are connected to ganglia of the duodenum, appear to be comprised of distinct populations of excitatory and inhibitory neurons, based on their expression of choline acetyltransferase and substance P or nitric oxide synthase, respectively. While SO neurons likely receive vagal input and their activity is modulated by release of neuropeptides from sensory fibers, a significant source of excitatory synaptic input to these cells arise from the duodenum. This duodenum-SO circuit is likely to play an important role in the coordination of SO tone with gallbladder motility in the process of gallbladder emptying. Now that we have gained a relatively thorough understanding of the innervation of the biliary tree under healthy conditions, the way is paved for future studies of altered neural function in biliary disease.

Electrical activation of common bile duct nerves modulates sphincter of Oddi motility in the Australian possum

BACKGROUND

Sphincter of Oddi (SO) motility is regulated by extrinsic and intrinsic nerves. The existence of neural circuits between the SO and the proximal extrahepatic biliary tree has been reported, but they are poorly understood. Using electrical field stimulation (EFS), we determined if a neural circuit exists between the common bile duct (CBD) and the SO in anaesthetized Australian brush-tailed possums.

METHODS

The gallbladder, cystic duct or CBD were subjected to EFS with a stimulating electrode. Spontaneous SO phasic waves were measured by manometry.

RESULTS

EFS at sites on the distal CBD (12-20 mm proximal to the SO), but less commonly at more proximal CBD, evoked a variety of responses consisting of an excitatory and/or inhibitory phase. Bi-phasic responses consisting of an excitation followed by inhibition were the most common. Tri-phasic responses were also observed as well as excitation or inhibition only. These evoked responses were blocked by topical application of local anaesthetic to the distal CBD or transection of the CBD. EFS at sites on the gallbladder body, neck or cystic duct did not consistently evoke an SO response. Pretreatment with atropine or guanethidine reduced the magnitude of the evoked response by about 50% (p<0.05), pretreatment with hexamethonium had no consistent effect and pretreatment with a nitric oxide synthase inhibitor increased the response.

DISCUSSION

A neural circuit(s) between the SO and the distal CBD modulates SO motility. Damage to this area of the CBD during bile duct exploration surgery could adversely affect SO motility.

Function of opioids in the enteric nervous system

Alterations in gastrointestinal motility and secretion underlie the constipating action of therapeutically administered opiates. The prototype opiate is morphine, which acts to delay gastric emptying and intestinal transit, to suppress intestinal secretion of water and electrolytes and to suppress transport of bile into the duodenum. The effects of opiates, synthetic opioids and endogenously released opioid peptides on these organ-level gastrointestinal functions reflect actions on electrical and synaptic behaviour of neurones in the enteric nervous system. Adverse effects and positive therapeutic effects of administration of opioid-receptor-blocking drugs on the digestive tract must be understood in the context of the neurophysiology of the enteric nervous system and mechanisms of neural control of gastrointestinal smooth muscle, secretory glands and blood-lymphatic vasculature. We review here the integrated systems of physiology and cellular neurobiology that are basic to understanding the actions of opioid agonists and antagonists in the digestive tract.

Intestinal dysmotility and its relationship to sphincter of Oddi dysfunction

Sphincter of Oddi dysfunction (SOD) is a clinical entity that presents with pain as the predominant symptom, and patients may require invasive procedures for its proper diagnosis. Those with abnormal sphincter of Oddi manometry (SOM) are commonly treated with endoscopic ablation of the sphincter. The results of such therapy vary and depend on the type of SOD. In the past several years, evidence has emerged of an association between SOD, intestinal dysmotility, and visceral hyperalgesia. This article reviews the evidence supporting such an association.

The possum sphincter of Oddi pumps or resists flow depending on common bile duct pressure: a multilumen manometry study

The sphincter of Oddi (SO) regulates trans-sphincteric flow (TSF) by acting primarily as a pump or as a resistor in specific species. We used the Australian possum SO, which functions similarly to the human SO, to characterize SO motility responses to different common bile duct (CBD) and duodenal pressures. Possum CBD, SO and attached duodenum (n= 18) was mounted in an organ bath. External reservoirs were used to impose CBD (0-17 mmHg) and duodenal (0, 4, 7 mmHg) pressure. Spontaneous SO activity was recorded using four-lumen pico-manometry and TSF was measured gravimetrically. Temporal analysis of manometric and TSF recordings identified three functionally distinct biliary-SO regions, the proximal-SO (juxta-CBD), body-SO and papilla-SO. At CBD pressures < 3 mmHg the motor activity of these regions was coordinated to pump fluid. Proximal-SO contractions isolated fluid within the body-SO. Peristaltic contraction through the body-SO pumped this fluid through the papilla-SO (17-27 microl contraction), which opened to facilitate flow. CBD pressure > 3.5 mmHg resulted in progressive changes in TSF to predominantly passive 'resistor'-type flow, occurring during proximal-SO-body-SO quiescence, when CBD pressure exceeded the pressure at the papilla-SO. Progression from pump to resistor function commenced when CBD pressure was 2-4 mmHg greater than duodenal pressure. These results imply that TSF is dependent on the CBD-duodenal pressure difference. The papilla-SO is pivotal to TSF, relaxing during proximal-SO-body-SO pumping and closing during proximal-SO-body-SO quiescence. The pump function promotes TSF at low CBD pressure and prevents bile stasis. At higher CBD pressure, the papilla-SO permits TSF along a pressure gradient, thereby maintaining a low pressure within the biliary tract.

Nontraumatic pancreatitis in spinal cord injury

STUDY DESIGN

A retrospective analysis of 10 patients with pancreatitis after traumatic spinal cord injury.

OBJECTIVES

To determine the conditions leading to nontraumatic pancreatitis in spinal cord injury.

SUMMARY OF BACKGROUND DATA

Little is known in the literature about pancreatitis after spinal cord injury. A few authors suggest a multifactorial pathogenesis.

METHODS

Over a 4-year period the case reports of 338 patients with traumatically caused SCI were reviewed concerning p-amylase and/or lipase elevations. Acute pancreatitis was defined as an elevation of p-amylase and/or lipase of more than three times the upper normal limit.

RESULTS

Ten of 338 patients had p-amylase and/or lipase elevations three times higher than the upper normal limit. All 10 were male with a mean age of 40.4 years. The average onset time of acute pancreatitis was 16 +/- 5.5 days after trauma. The usual etiologic factors of acute pancreatitis such as obstructive, toxic, or traumatic events were excluded.

CONCLUSION

The clinical recognition of acute pancreatitis in paraplegic and quadriplegic patients is hampered by diminished or lost visceral sensitivity and therefore is based on laboratory investigations. The current authors therefore hypothesize that acute pancreatitis in the setting of high-level spinal cord injury may result from a combination of locally mediated sphincter of Oddi dysfunction and vagal dominant innervation of the pancreatic gland in autonomic failure.