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

Benchmarking in pancreatic surgery: a systematic review of metric development and validation

Benchmarking in healthcare, particularly in the context of complex surgical procedures like pancreatic surgery, plays a pivotal role in comparing and evaluating the quality of care provided to patients. There is a growing body of evidence validating existent metrics and introducing new ones in the pursuit of safety and excellence in pancreatic surgery. A systematic review adhering to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines was conducted on metric development and validation across multiple databases, including PUBMED Medline, Scopus, and Web of Science, until February 2024. The extracted data were categorized into three domains according to the Donabedian model: structure, process, and outcomes. Thirty-four studies were deemed eligible for inclusion in this review. Among these articles, 20 contributed to metric development, while 14 studies validated them. A total of 234 metrics were identified across the 34 studies, of which 185 were included in the analysis. Thirty-three of these metrics were relative to structure, 79 to processes, and 73 to outcomes. The distribution of metric domains across the included studies revealed that structure, process, and outcome domains were reported in 12, 26, and 26 studies, respectively. In conclusion, this systematic review underscores the heterogeneity in metric development methodologies and the varying degrees of consensus among different quality indicators, despite the growing interest in benchmarking in pancreatic surgery. This review aims to inform future research efforts and contribute to the ongoing pursuit of excellence in pancreatic surgical care.

Clinical significance of bile reflux into the pancreatic duct without pancreaticobiliary maljunction assessed by intraoperative cholangiography

INTRODUCTION

Bile reflux into the pancreatic duct (BRPD) is sometimes demonstrated during intraoperative cholangiography (IOC) even in patients without pancreaticobiliary maljunction. However, the clinical significance of this finding in laparoscopic and open cholecystectomy is unclear.

METHODS

Among 484 patients who underwent cholecystectomy (372 laparoscopic, 112 open), patients whose pancreatic duct was depicted in IOC were selected. The value of pancreatic amylase (p-amylase) of the gallbladder bile, histological changes, and the immunohistochemical expression of proliferating cell nuclear antigen (PCNA) in the gallbladder mucosa were analyzed in patients with BRPD. The data were then compared to those in patients without BRPD whose gallbladder bile p-amylase was measured (control group, n = 20).

RESULTS

The success rate of IOC was 93.6%. The rate of BRPD in laparoscopic and open cholecystectomy was 5.2% and 5.7%, respectively. The value of gallbladder bile p-amylase in patients with BRPD was significantly higher than in the control group (790.5 vs 14.0 IU/L, P = 0.034). The value of the PCNA labeling index in patients with BRPD was significantly higher than that of the control group (15.4% vs 4.1%, P = 0.0026). Among the 24 patients with BRPD, pathological changes in the gallbladder mucosa were detected in five (two hyperplasia, three metaplasia), but there was no correlation between the presence of pathological change and PCNA labeling index or gallbladder bile p-amylase.

CONCLUSIONS

IOC could detect BRPD both in laparoscopic and open cholecystectomy at a similar rate. Patients with BRPD had high levels of gallbladder bile p-amylase and PCNA labeling index, findings similar to those in patients with pancreaticobiliary maljunction.

Symptomatic cholelithiasis and functional disorders of the biliary tract

Symptomatic cholelithiasis and functional disorders of the biliary tract present with similar signs and symptoms. The functional disorders of the biliary tract include functional gallbladder disorder, dyskinesia, and the sphincter of Oddi disorders. Although the diagnosis and treatment of symptomatic cholelithiasis are relatively straightforward, the diagnosis and treatment of functional disorders can be much more challenging. Many aspects of the diagnosis and treatment of functional disorders are in need of further study. This article discusses uncomplicated gallstone disease and the functional disorders of the biliary tract to emphasize and update the essential components of diagnosis and management.

How to interpret a functional or motility test - sphincter of oddi manometry

To date, endoscopic manometry is the best method for evaluating the function of the sphincter. Sphincter of Oddi manometry (SOM) remains the gold standard to correctly diagnose the sphincter of Oddi dysfunction (SOD) and stratify therapy. Several dynamic abnormalities relating to the intensity, frequency, and propagation of sphincter contractions have been described. However, their clinical use generally has been abandoned in favor of basal sphincter pressure alone, because this measurement is stable over time, and has stronger interobserver reliablility, reproducibility on repeating testing, and is associated with the responsiveness to therapy. A significant elevated risk of pancreatitis was attributed to the technique. The risk of pancreatitits associated with manometric evaluation of the pancreatic sphincter is markedly reduced when manometry is performed with continous aspiration from the pancreatic duct via one of the 3 catheter lumens. This section reviews indications, conscious sedative drugs, techniques, and the appropriate interpretations of SOM.

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.

Biliary and gallbladder dyskinesia

Gallbladder and biliary dyskinesia are conditions that are becoming increasingly recognized due to improved technology. They are motility disorders that affect the gallbladder and sphincter of Oddi (SO), respectively. Gallbladder dyskinesia presents with typical biliary pain in the absence of gallstones. Work-up includes laboratory tests and imaging to rule out gallstones. Further investigation leads to a functional radionuclide study to investigate gallbladder ejection fraction. An ejection fraction of less than 40% is considered abnormal, and patients should be referred for cholecystectomy. Symptom relief after the procedure has been seen in 94% to 98% of patients. The term sphincter of Oddi dysfunction (SOD) describes a collection of pain syndromes that are attributed to a motility disorder of the SO. SOD can be further subdivided into biliary and pancreatic SOD. Patients typically have had a prior cholecystectomy and present with episodic biliary pain. The initial work-up includes laboratory tests and imaging to rule out other structural causes of abdominal pain, such as retained gallstones. Imaging and laboratory studies further subdivide patients into types of SOD. SO manometry (SOM) is the gold standard for assessing biliary dyskinesia and can help stratify patients into one of two groups: SO stenosis versus SO dyskinesia. Those with stenosis (type I SOD) are the most likely to respond to treatment with endoscopic biliary sphincterotomy (EBS). As the vast majority of type I patients (>/= 90%) benefit from EBS, SOM is not necessary. Pancreatic SOD patients can be similarly divided into one of three groups. These patients present with recurrent bouts of abdominal pain and/or pancreatitis in the absence of gallstones or other structural abnormalities. Pancreatic sphincter manometry can help distinguish which patients would benefit from endoscopic pancreatic sphincterotomy. Recurrent stenosis of the opening after endoscopic treatment in these patients may necessitate a surgical (open) approach.

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.

Post-cholecystectomy syndrome: spectrum of biliary findings at magnetic resonance cholangiopancreatography

Post-cholecystectomy syndrome (PCS) is defined as a complex of heterogeneous symptoms, consisting of upper abdominal pain and dyspepsia, which recur and/or persist after cholecystectomy. Nevertheless, this term is inaccurate, as it encompasses biliary and non-biliary disorders, possibly unrelated to cholecystectomy. Biliary manifestations of PCS may occur early in the post-operative period, usually because of incomplete surgery (retained calculi in the cystic duct remnant or in the common bile duct) or operative complications, such as bile duct injury and/or bile leakage. A later onset is commonly caused by inflammatory scarring strictures involving the sphincter of Oddi or the common bile duct, recurrent calculi or biliary dyskinesia. The traditional imaging approach for PCS has involved ultrasound and/or CT followed by direct cholangiography, whereas manometry of the sphincter of Oddi and biliary scintigraphy have been reserved for cases of biliary dyskinesia. Because of its capability to provide non-invasive high-quality visualisation of the biliary tract, magnetic resonance cholangiopancreatography (MRCP) has been advocated as a reliable imaging tool for assessing patients with suspected PCS and for guiding management decisions. This paper illustrates the rationale for using MRCP, together with the main MRCP biliary findings and diagnostic pitfalls.

Effects of vardenafil, a phosphodiesterase type-5 inhibitor, on sphincter of Oddi motility in patients with suspected biliary sphincter of Oddi dysfunction

BACKGROUND

The therapeutic approach in patients with sphincter of Oddi (SO) dysfunction (SOD) aims to reduce the resistance to the flow of bile or pancreatic juice. Vardenafil inhibits the activity of phosphodiesterase type 5 (PDE-5), which degrades cyclic guanossine monophosphate (cGMP) and results in relaxation of smooth muscle.

OBJECTIVE

The present study was performed to determine the effects of vardenafil on SO motility in patients with suspected SOD.

DESIGN

Prospective study.

SETTINGS

Single university center.

PATIENTS AND INTERVENTIONS

Twenty consecutive adult patients with suspected SOD were scheduled to undergo ERCP and SO manometry by standard methods. A second recording was performed in the same position 20 minutes after administration of 10 mg vardenafil dissolved in 10 mL saline solution into the duodenum through a conventional catheter. SO pressures and motor function were compared in all patients with suspected SOD before and after administration of vardenafil.

RESULTS

After administration of 10 mg of vardenafil, the mean basal sphincter pressure was reduced from 59.5 to 26.9 mm Hg (P < .001), and the mean phasic amplitude was reduced from 132.2 to 66.2 mm Hg (P < .001). The mean phasic wave frequency was not changed after administration of vardenafil (7.2/min vs 6.6/min, respectively, P = .07). These results did not differ between SOD types. No significant difference in manometric data were detected before and after administration of vardenafil between cholecystectomy and gallbladder in situ groups. Transient headache was observed in 1 patient, and the procedure-related complication was post-ERCP pancreatitis (n = 2 [10%]).

LIMITATIONS

The small sample size and uncontrolled study.

CONCLUSION

Vardenafil inhibits SO motility in patients with suspected SOD and reduces basal SO pressure, without significant adverse effects.

Biliary dyskinesia

Functional disorders of the biliary tract include gallbladder dyskinesia (GBD) and sphincter of Oddi dysfunction (SOD). The diagnosis of GBD is made if the gallbladder ejection fraction is less than 35% to 40% using cholecystokinin cholescintigraphy. Despite slightly inferior outcomes compared with calculous disease, patients who have GBD should be treated with cholecystectomy. SOD is most often noted in the postcholecystectomy patient and symptoms can be biliary or pancreatic in nature. The gold standard for diagnosis remains manometry, with basal biliary or pancreatic sphincter pressures measuring greater than 40 mm Hg. Patients who have increased pressures may benefit from endoscopic sphincterotomy.

Pancreatic sphincterotomy: Technique, indications, and complications

Pancreatic sphincterotomy serves as the cornerstone of endoscopic therapy of the pancreas. Historically, its indications have been less well-defined than those of endoscopic biliary sphincterotomy, yet it plays a definite and useful role in diseases such as chronic pancreatitis and pancreatic-type sphincter of Oddi dysfunction. In the appropriate setting, it may be used as a single therapeutic maneuver, or in conjunction with other endoscopic techniques such as pancreatic stone extraction or stent placement. The current standard of practice utilizes two different methods of performing pancreatic sphincterotomy: a pull-type sphincterotome technique without prior stent placement, and a needle-knife sphincterotome technique over an existing stent. The complications associated with pancreatic sphincterotomy are many, although acute pancreatitis appears to be the most common and the most serious of the early complications. As such, it continues to be reserved for those endoscopists who perform a relatively high-volume of therapeutic pancreaticobiliary endoscopic retrograde cholangio-pancreatography.

Postcholecystectomy sphincter of oddi dyskinesia--a diagnostic dilemma--role of noninvasive nuclear and invasive manometric and endoscopic aspects

BACKGROUND

Persistent abdominal pain after cholecystectomy is not uncommon. Sphincter of oddi dysfunction (SOD) is one of the causes for this entity. However, diagnosing SOD is often difficult. Sphincter of oddi manometry (SOM) is the gold standard. Because it is invasive and needs experienced person to perform, simple noninvasive imaging techniques are needed. Other invasive endoscopic methods also play an important role in difficult cases and before therapeutic intervention.

METHODS

Retrospective review of the charts of postcholecystectomy patients who presented with persistent abdominal pain and underwent quantitative hepatobiliary studies (QHBS) as per Sostre et al scoring protocol and simultaneous endoscopic retrograde cholangiopancreatography (ERCP) with SOM between 2003 and 2004. Additional 6 studies with SOM data that had routine nonscoring hepatobiliary study (HBS) were later identified and were included in the study.

RESULTS

A total of 24 HBS studies (22 patients) were identified, 19 performed with scoring (Sostre) and 5 with nonscoring methods. ERCP results were available for 16 patients. SOM results were available for 10 patients. Of the 19 who had Sostre's QHBS, 3 were positive and 16 were negative. All 3 QHBS positive patents also had ERCP with SOM findings of SOD. Of the 16 negative Sostre's QHBS, 8 had ERCP with SOM of which 6 had SOD, 1 had no SOD, and 1 was inconclusive. Eight patients who had negative QHBS/ HBS did not undergo further invasive gastrointestinal procedures and were followed conservatively. The rest of 5 patients with negative HBS had ERCP with SOM findings of biliary and pancreatic SOD.

CONCLUSIONS

From our limited retrospective review, when QHBS by Sostre's is positive there is good correlation to ERCP with SOM. When negative, the agreement with ERCP with SOM is less. However, correlation of Sostre's QHBS is slightly better than nonscoring HBS. Hence, QHBS by Sostre protocol is a simple, noninvasive, and easy to use initial procedure in the management of postcholecystectomy pain syndromes and when positive can guide the gastrointestinal physicians to proceed to invasive ERCP with SOM with confidence.