Does continuous aspiration from an end and side port in a sphincter of Oddi manometry catheter alter recorded pressures?

Sphincter of Oddi dysfunction and pancreatitis

Sphincter of Oddi dysfunction (SOD) is a term used to describe a group of heterogenous pain syndromes caused by abnormalities in sphincter contractility. Biliary and pancreatic SOD are each sub-classified as type I, II or III, according to the Milwaukee classification. SOD appears to carry an increased risk of acute pancreatitis as well as rates of post ERCP pancreatitis of over 30%. Various mechanisms have been postulated but the exact role of SOD in the pathophysiology of acute pancreatitis is unknown. There is also an association between SOD and chronic pancreatitis but it is still unclear if this is a cause or effect relationship. Management of SOD is aimed at sphincter ablation, usually by endoscopic sphincterotomy (ES). Patients with type I SOD will benefit from ES in 55%-95% of cases. Sphincter of Oddi manometry is not necessary before ES in type I SOD. For patients with types II and III the benefit of ES is lower. These patients should be more thoroughly evaluated before performing ES. Some researchers have found that manometry and ablation of both the biliary and pancreatic sphincters is required to adequately assess and treat SOD. In pancreatic SOD up to 88% of patients will benefit from sphincterotomy. Therefore, there have been calls from some quarters for the current classification system to be scrapped in favour of an overall system encompassing both biliary and pancreatic types. Future work should be aimed at understanding the mechanisms underlying the relationship between SOD and pancreatitis and identifying patient factors that will help predict benefit from endoscopic therapy.

Sphincter of Oddi dysfunction and pancreatitis

Sphincter of Oddi dysfunction (SOD) is a term used to describe a group of heterogenous pain syndromes caused by abnormalities in sphincter contractility. Biliary and pancreatic SOD are each sub-classified as typeI, II or III, according to the Milwaukee classification. SOD appears to carry an increased risk of acute pancreatitis as well as rates of post ERCP pancreatitis of over 30%. Various mechanisms have been postulated but the exact role of SOD in the pathophysiology of acute pancreatitis is unknown. There is also an association between SOD and chronic pancreatitis but it is still unclear if this is a cause or effect relationship. Management of SOD is aimed at sphincter ablation, usually by endoscopic sphincterotomy (ES). Patients with typeISOD will benefit from ES in 55%-95% of cases. Sphincter of Oddi manometry is not necessary before ES in typeISOD. For patients with types II and III the benefit of ES is lower. These patients should be more thoroughly evaluated before performing ES. Some researchers have found that manometry and ablation of both the biliary and pancreatic sphincters is required to adequately assess and treat SOD. In pancreatic SOD up to 88% of patients will benefit from sphincterotomy. Therefore, there have been calls from some quarters for the current classification system to be scrapped in favour of an overall system encompassing both biliary and pancreatic types. Future work should be aimed at understanding the mechanisms underlying the relationship between SOD and pancreatitis and identifying patient factors that will help predict benefit from endoscopic therapy.

Key issues in sphincter of Oddi dysfunction

SOD is a challenging condition that is difficult to diagnose and treat. The high failure rate of endoscopic and surgical treatment reflects the difficulties in establishing accurate diagnosis and the lack of specific objective criteria by which appropriate therapy could be determined. In general, sphincter ablation should be offered for type I patients. An initial trial of medical therapy is appropriate for type II patients with mild-to-moderate symptoms and for all type III patients. SOM is highly recommended for type II patients and is mandatory for all type III patients if sphincter ablation is contemplated. Other causes of abdominal pain such as chronic pancreatitis or functional disorders should be considered in patients not benefiting from sphincter ablation. All procedures on the sphincter should be undertaken with caution after meticulous investigation, and patient selection should be based on strict objective criteria.

Diagnosis and treatment of sphincter of Oddi dysfunction

BACKGROUND Sphincter of Oddi dysfunction is a challenge from both the diagnostic and therapeutic point of view. There is much ongoing debate about the accuracy and usefulness of various diagnostic tests, as there is about the effectiveness of proposed therapeutic alternatives.

METHODS

A comprehensive review of the past 15 years' literature was undertaken, using the Medline database and cross-referencing of major articles on the subject.

RESULTS AND CONCLUSION

Endoscopic and surgical treatments result in similar outcomes, with considerable failure rates. The latter reflect the difficulties in accurate diagnosis and a lack of sound objective criteria for selecting patients for intervention. In addition, in some patients sphincter of Oddi dysfunction may be only part of a generalized motility disorder of the gastrointestinal tract.

Effects of meperidine on the pancreatic and biliary sphincter

BACKGROUND

Opioids are traditionally avoided during sphincter of Oddi manometry because of indirect evidence suggesting that these agents cause sphincter of Oddi spasm. This study was undertaken to determine the direct effects of meperidine on the biliary and pancreatic sphincter.

METHODS

Forty-seven patients were prospectively evaluated by sphincter of Oddi manometry in the conventional retrograde fashion. Manometry was initially performed with intravenous diazepam sedation alone. The manometry was repeated 3 to 5 minutes after meperidine was administered.

RESULTS

The basal sphincter pressure of the biliary sphincter, pancreatic sphincter, and the combined sphincter group were not significantly altered by meperidine. Concordance (normal versus abnormal) between the basal sphincter pressure before and after meperidine was seen in 44 of 47 patients (94%). Meperidine produced a significant increase in the pancreatic, biliary, and combined sphincter phasic frequency and a significant decrease in the phasic duration. The pancreatic and combined sphincter phasic pressures were significantly reduced following meperidine administration. Seventeen manometry tracings (36%) were believed to be qualitatively better after meperidine, while only four (8.5%; p < .001) were qualitatively better with diazepam alone.

CONCLUSION

Meperidine can be used for additional analgesia during sphincter of Oddi manometry if the basal sphincter pressure is the parameter used to determine therapy.

Pancreatitis following bile duct sphincter of Oddi manometry: utility of the aspirating catheter

The aspirating sphincter of Oddi manometry (SOM) catheter was shown to reduce the frequency of post-procedure pancreatitis from 31% to 4% following a pancreatic duct evaluation. This study was designed to prospectively evaluate the utility of the aspirating manometry catheter in reducing the frequency of pancreatic enzyme elevation and clinical pancreatitis following isolated bile duct manometry. Thirty-eight patients were randomly assigned to undergo bile duct SOM with the standard perfusion (infused group) catheter or the aspirating catheter (aspirated group). Overall, the frequency of both amylase and lipase level elevation at least two times the upper limits of normal was 30% at 2 hours, 25% at 6 hours, and 18% at 18 hours after the procedure and was similar for the aspirated and infused groups. No episodes of clinical pancreatitis occurred in either group. The SOM catheter was perfused with full-strength contrast in 12 consecutive patients undergoing a bile duct evaluation. Only one patient had any contrast material identified in the pancreatic duct. The results of this study support the theory that increased pancreatic duct hydrostatic pressure is the major cause for post-SOM pancreatitis and suggests that SOM evaluation of the bile duct alone appears to be safe.