Clinical aspects of sphincter of Oddi function and dysfunction

Endoscopic sphincterotomy for adults with biliary sphincter of Oddi dysfunction

BACKGROUND

The sphincter of Oddi comprises a muscular complex encircling the distal part of the common bile duct and the pancreatic duct regulating the outflow from these ducts. Sphincter of Oddi dysfunction refers to the abnormal opening and closing of the muscular valve, which impairs the circulation of bile and pancreatic juices.

OBJECTIVES

To evaluate the benefits and harms of any type of endoscopic sphincterotomy compared with a placebo drug, sham operation, or any pharmaceutical treatment, administered orally or endoscopically, alone or in combination, or a different type of endoscopic sphincterotomy in adults with biliary sphincter of Oddi dysfunction.

SEARCH METHODS

We used extensive Cochrane search methods. The latest search date was 16 May 2023.

SELECTION CRITERIA

We included randomised clinical trials assessing any type of endoscopic sphincterotomy versus placebo drug, sham operation, or any pharmaceutical treatment, alone or in combination, or a different type of endoscopic sphincterotomy in adults diagnosed with sphincter of Oddi dysfunction, irrespective of year, language of publication, format, or outcomes reported.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods and Review Manager to prepare the review. Our primary outcomes were: proportion of participants without successful treatment; proportion of participants with one or more serious adverse events; and health-related quality of life. Our secondary outcomes were: all-cause mortality; proportion of participants with one or more non-serious adverse events; length of hospital stay; and proportion of participants without improvement in liver function tests. We used the outcome data at the longest follow-up and the random-effects model for our primary analyses. We assessed the risk of bias of the included trials using RoB 2 and the certainty of evidence using GRADE. We planned to present the results of time-to-event outcomes as hazard ratios (HR). We presented dichotomous outcomes as risk ratios (RR) and continuous outcomes as mean difference (MD) with their 95% confidence intervals (CI).

MAIN RESULTS

We included four randomised clinical trials, including 433 participants. Trials were published between 1989 and 2015. The trial participants had sphincter of Oddi dysfunction. Two trials were conducted in the USA, one in Australia, and one in Japan. One was a multicentre trial conducted in seven US centres, and the remaining three were single-centre trials. One trial used a two-stage randomisation, resulting in two comparisons. The number of participants in the four trials ranged from 47 to 214 (median 86), with a median age of 45 years, and the mean proportion of males was 49%. The follow-up duration ranged from one year to four years after the end of treatment. All trials assessed one or more outcomes of interest to our review. The trials provided data for the comparisons and outcomes below, in conformity with our review protocol. The certainty of evidence for all the outcomes was very low. Endoscopic sphincterotomy versus sham Endoscopic sphincterotomy versus sham may have little to no effect on treatment success (RR 1.05, 95% CI 0.66 to 1.66; 3 trials, 340 participants; follow-up range 1 to 4 years); serious adverse events (RR 0.71, 95% CI 0.34 to 1.46; 1 trial, 214 participants; follow-up 1 year), health-related quality of life (Physical scale) (MD -1.00, 95% CI -3.84 to 1.84; 1 trial, 214 participants; follow-up 1 year), health-related quality of life (Mental scale) (MD -1.00, 95% CI -4.16 to 2.16; 1 trial, 214 participants; follow-up 1 year), and no improvement in liver function test (RR 0.89, 95% CI 0.35 to 2.26; 1 trial, 47 participants; follow-up 1 year), but the evidence is very uncertain. Endoscopic sphincterotomy versus endoscopic papillary balloon dilation Endoscopic sphincterotomy versus endoscopic papillary balloon dilationmay have little to no effect on serious adverse events (RR 0.34, 95% CI 0.04 to 3.15; 1 trial, 91 participants; follow-up 1 year), but the evidence is very uncertain. Endoscopic sphincterotomy versus dual endoscopic sphincterotomy Endoscopic sphincterotomy versus dual endoscopic sphincterotomy may have little to no effect on treatment success (RR 0.65, 95% CI 0.32 to 1.31; 1 trial, 99 participants; follow-up 1 year), but the evidence is very uncertain. Funding One trial did not provide any information on sponsorship; one trial was funded by a foundation (the National Institutes of Diabetes and Digestive and Kidney Diseases, NIDDK), and two trials seemed to be funded by the local health institutes or universities where the investigators worked. We did not identify any ongoing randomised clinical trials.

AUTHORS' CONCLUSIONS

Based on very low-certainty evidence from the trials included in this review, we do not know if endoscopic sphincterotomy versus sham or versus dual endoscopic sphincterotomy increases, reduces, or makes no difference to the number of people with treatment success; if endoscopic sphincterotomy versus sham or versus endoscopic papillary balloon dilation increases, reduces, or makes no difference to serious adverse events; or if endoscopic sphincterotomy versus sham improves, worsens, or makes no difference to health-related quality of life and liver function tests in adults with biliary sphincter of Oddi dysfunction. Evidence on the effect of endoscopic sphincterotomy compared with sham, endoscopic papillary balloon dilation,or dual endoscopic sphincterotomyon all-cause mortality, non-serious adverse events, and length of hospital stay is lacking. We found no trials comparing endoscopic sphincterotomy versus a placebo drug or versus any other pharmaceutical treatment, alone or in combination. All four trials were underpowered and lacked trial data on clinically important outcomes. We lack randomised clinical trials assessing clinically and patient-relevant outcomes to demonstrate the effects of endoscopic sphincterotomy in adults with biliary sphincter of Oddi dysfunction.

Sphincter of Oddi Dysfunction and the Formation of Adult Choledochal Cyst Following Cholecystectomy: A Retrospective Cohort Study

To determine the causes underlying the formation of adult choledochal cyst.Anomalous pancreaticobiliary junction is the most widely accepted theory regarding the etiology of choledochal cyst. However, choledochal cysts have been found in patients in the absence of this anomaly. Because the number of adult patients with choledochal cyst is increasing, it is important to address this controversy.Bile amylase levels in the cysts of 27 patients (8 males and 19 females) who had undergone cholecystectomy were retrospectively evaluated.The average age of the 27 patients was 45.8 ± 10.1 years and the majority (85.2%) were diagnosed with Todani type I cysts. None of the patients had dilatation of the common bile duct prior to surgery. There were 6 (22.2%) patients with anomalous pancreaticobiliary junction. However, amylase levels did not significantly differ between patients with and without this anomaly (P = 0.251). According to bile amylase levels, pancreatobiliary reflux was present in 21 (77.8%) patients. The mean amylase level significantly differed in patients with pancreatobiliary reflux (23,462 ± 11,510 IU/L) and those without (235 ± 103 IU/L) (P < 0.001). In patients with pancreatobiliary reflux, only 4 patients had anomalous pancreaticobiliary junction. That is, the majority of patients (17/21, 81%) having pancreatobiliary reflux did not have an anomalous junction of the pancreatic and biliary ducts.Since the only explanation for pancreatobiliary reflux in patients with a normal pancreaticobiliary junction is sphincter of Oddi dysfunction, we proposed that the formation of adult choledochal cyst is mainly due to sphincter of Oddi dysfunction.

Update on biliary and pancreatic sphincterotomy

PURPOSE OF REVIEW

To summarize the indications, success rates and complications associated with endoscopic sphincterotomy and endoscopic balloon dilation (EBD).

RECENT FINDINGS

Pancreatic and/or biliary sphincterotomies are essential components of most current therapeutic endoscopic retrograde cholangiopancreatography (ERCP). A current large body of evidence has established biliary sphincterotomy as effective in extraction of bile duct stones. The most common complications of biliary sphincterotomy are post-ERCP pancreatitis, as well as acute or delayed hemorrhage, the risks for which can be stratified according to well described patient and procedure related factors. Evidence is accumulating that pancreatic sphincterotomy is useful in at least some settings for treatment of sphincter of Oddi dysfunction, chronic pancreatitis, and pancreas divisum. EBD provides an adjunct or an alternative to biliary sphincterotomy for extraction of stones from the bile duct when routine biliary sphincterotomy is inadequate or risk excessive.

SUMMARY

Sphincterotomy and EBD are useful in managing a variety of pancreatobiliary conditions. Attention to risks of these procedures is essential for their efficacy and safety.

Current knowledge on pancreaticobiliary reflux in normal pancreaticobiliary junction

Knowledge on pancreaticobiliary reflux in normal pancreaticobiliary junction and their pathologic implications has experienced tremendous progress during the last few years. This article reviews the current knowledge on this condition and its pathological implications on gallbladder diseases. Many publications with different levels of evidence were found supporting biliary carcinogenesis associated with pancreaticobiliary reflux in normal and abnormal pancreaticobiliary junction. Also, there are many publications supporting the common occurrence of pancreaticobiliary reflux in normal pancreaticobiliary junction, and sphincter of Oddi dysfunction as the most plausible cause of this condition. Although an important body of research has been published regarding pancreaticobiliary reflux in normal pancreaticobiliary junction and their clinical significance, the current evidence does not fully support what has been suggested. The reflux of pancreatic enzymes into the bile tract and gallbladder is a fascinating subject of study which is open to active research. The final demonstration of the pathophysiology and consequences of PBR in NPBL and support by evidence level type I would constitute a major breakthrough in the understanding and eventually in the treatment of gallbladder diseases.

Pancreaticobiliary reflux in patients with a normal pancreaticobiliary junction: Pathologic implications

Knowledge on pancreaticobiliary reflux in normal pancreaticobiliary junction and its pathologic implications has experienced tremendous progress during the last few years. This editorial reviews the current knowledge on this condition and its pathological implications on gallbladder diseases. The following aspects were defined appropriate for discussion: (1) Evidence of carcinogenesis associated with pancreaticobiliary reflux; (2) Evidence of pancreaticobiliary reflux in normal pancreaticobiliary junction; and (3) Evidence of sphincter of Oddi (SO) dysfunction as a cause of pancreaticobiliary reflux in normal pancreaticobiliary junction. The articles reviewed were selected and classified according to five levels of evidence: LevelI, meta-analysis double-blind randomized clinical trials, Level II, cohort non-blinded studies and non-randomized clinical trials, Level III, good quality case-control studies and non-randomized cohort studies, Level IV, case series and poor quality case-control studies, and Level V, case report articles and experts’ opinion. Evidence levels II, III, IV and V were found to support biliary carcinogenesis associated with pancreaticobiliary reflux in normal and abnormal pancreaticobiliary junction. The same levels of evidence were found to support the common occurrence of pancreaticobiliary reflux in normal pancreaticobiliary junction, and SO dysfunction as the most plausible cause of this condition. Although an important body of research has been published regarding pancreaticobiliary reflux in normal pancreaticobiliary junction and its clinical significance, the current evidence does not fully support what has been suggested. Studies with evidence level I have not been undertaken. This is a fascinating subject of study, and if finally supported by evidence level I, the importance of this condition will constitute a major breakthrough in biliary pathology.

Predictors of outcomes after biliary and pancreatic sphincterotomy for sphincter of oddi dysfunction

BACKGROUND

There are few data on combined pancreatic and biliary sphincterotomy for sphincter of Oddi dysfunction (SOD), especially regarding clinical features that might predict outcomes. We sought to examine the relative importance of various clinical features and the presence or absence of objective biliary abnormalities in determining responses to endoscopic therapy.

METHODS

A cohort of consecutive patients with suspected SOD was treated with biliary sphincterotomy, with additional pancreatic sphincterotomy at initial or subsequent endoscopic retrograde cholangiopancreatography if there was abnormal pancreatic manometry in conjunction with pain refractory to biliary sphincterotomy, continuous pain, or a history of amylase elevation. Repeat intervention was offered until response was achieved or complete ablation of all treated sphincters was achieved. Response was assessed by patients using a 5-point Likert scale, and multivariate logistic regression analysis used to identify predictors of response.

RESULTS

Of 121 patients, 112 (92%) were female, 105 (87%) postcholecystectomy, and by modified Milwaukee biliary classification 18 (15%) were type I, 53 (44%) type II, and 50 (41%) type III. All patients underwent biliary sphincterotomy and 49 (40%) pancreatic sphincterotomy. Good or excellent response at final follow-up was reported by 83 (69%) of 121 patients, including 37 (61%) of 61 patients requiring repeated intervention. Response was not significantly different between biliary types I, II, and III. Patient characteristics (with adjusted odds ratios) that were significant predictors of poor response were normal pancreatic manometry (4.6), delayed gastric emptying (6.0), daily opioid use (4.0), and age <40 (2.7). Abnormal liver function tests or dilated bile duct were not significant.

CONCLUSIONS

For the treatment of SOD incorporating pancreatic and biliary sphincterotomy, patient characteristics and pancreatic sphincter manometry may be more important predictors of outcome than the traditional classification based on liver chemistries and bile duct dilation.

Bio-sensor system discriminating between the biliary and pancreatic ductal systems

Sphincter of Oddi manometry is the "gold standard" to evaluate the ductal anatomy of patients with suspected sphincter of Oddi dysfunction. During such procedure it can be unclear which duct is being investigated without radiographs. Bilirubin and other pigments in bile strongly absorb blue light, whereas pancreatic fluid is clear and does not absorb blue light. The bio-sensor system incorporates fibre-optic technology to measure blue light absorbance in the ducts. Bench tests and animal tests were conducted utilising possums. In bench and animal experiments the bio-sensor correctly discriminated between bile and pancreatic juice, based on the absorbance of blue light. The mean absorbance of the bile was 3.57+/-1.74 and that of the pancreatic duct fluid was 0.53+/-0.34 (P<0.01) in the animal models. The optical sensing system could be incorporated into a manometry catheter to aid sphincter of Oddi manometry shortening procedure time and reduce radiography exposure.

Reconstruction of the common bile duct by a vascular prosthetic graft: an experimental study in pigs

BACKGROUND/PURPOSE

The purpose of the present study was to investigate whether it was possible to use a vascular graft for reconstruction of the common bile duct (CBD) in pigs.

METHODS

Eight pigs, each weighing approximately 60 kg, were used for the experiments. The gallbladder was dissected and the cystic duct and cystic artery were ligated and divided. The CBD was displayed and divided. Then the CBD was reconstructed with a standard walled expanded polytetrafluoroethylene (ePTFE) vascular graft (internal diameter 4 mm) by means of 12 interrupted monofilament glycomer 63 (Biosyn) 4.0 sutures. The ends of the vascular graft were inserted into the CBD and the sutures were placed through the graft and the CBD in such a way that the latter would cover the former. The anastomotic line was covered by fibrin glue. On postoperative day 8, a laparotomy was performed; the pigs were investigated for signs of gall leakage, and cholangiography was performed. Blood samples for the determination of liver parameters were taken before the primary surgery and before the explorative laparotomy.

RESULTS

At evaluations on the eighth postoperative day, all animals except one were without signs of bile leakage. One pig had an encapsulated biloma. Another animal had to be operated on day 6 because of illness, and laparotomy showed a perforated gastric ulcer, but no bile leakage. Cholangiography revealed slight intrahepatic dilatation in all animals. Bilirubin and alkaline phosphatase levels were unaffected by the surgery.

CONCLUSIONS

Reconstruction of the CBD by means of a vascular graft seems to be a safe procedure in the short term in a pig model.

Diagnosing and treating Sphincter of Oddi dysfunction: a critical literature review and reevaluation

Sphincter of Oddi dysfunction is a pathologic syndrome, without considering etiology, physiopathology, or anatomic aspects of the condition. The clinical manifestations of the syndrome may be a consequence of an "organic stenosis" of the tract or a consequence of "abnormal motility" of the sphincter. Until some years ago, the gold standard technique for studying and treating this pathologic condition was endoscopic retrograde cholangiopancreatography. Two criteria for defining patients in the Milwaukee classification are related to this procedure. The Milwaukee classification was introduced to use clinical and radiologic criteria to define patients with Sphincter of Oddi dysfunction to choose the best treatment. Subsequently, great emphasis has been placed on manometry of the sphincter performed by endoscopic cannulation. The enormous increase of cholecystectomies by means of laparoscopic technique has increased the number of patients who return to their reference-surgeon with a post-cholecystectomy pain and possible Sphincter of Oddi dysfunction. The aim of this paper is to review the literature and to evaluate an up-to-date flow chart for diagnosing and treating the syndrome by using alternative diagnostic procedures that are less invasive than endoscopic retrograde cholangiopancreatography.

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.

Sphincter of Oddi dysfunction associated with choledochal cyst

The pathophysiology of choledochal cysts remains unclear, although an association with anomalous pancreato-biliary junction and the reflux of pancreatic enzymes into the biliary tree is known. Sphincter of Oddi (SO) manometry was performed in three patients with choledochal cysts. All patients exhibited an elevated basal pressure diagnostic of sphincter of Oddi dysfunction. Two patients exhibited anomalous pancreato-biliary junction. This report suggests an association between the choledochal cyst and sphincter of Oddi dysfunction, and may suggest that SO dysfunction plays a role in choledochal cyst formation.