Endosonography-guided drainage of a pancreatic pseudocyst

Endoscopic ultrasound-guided fine-needle aspiration biopsy and interventional endoscopic ultrasonography. Emerging technologies

Endoscopic ultrasonography (EUS) has been shown to be useful in the detection and staging of gastrointestinal and pancreatic malignancies. However, EUS has some limitations including suboptimal specificity in lymph node staging. This is one factor that has curtailed its widespread use. The emergence of EUS-guided fine-needle aspiration (FNA) and other interventional applications of EUS appear likely to increase the clinical utility and cost-effectiveness of this modality. This article reviews recent literature describing the role of EUS in guiding FNA, detecting choledocholithiasis and assisting in interventions such as pseudocyst drainage.

Endoscopic ultrasound-guided fine needle aspiration in the diagnosis and staging of pancreatic tumors

Endoscopic ultrasound (EUS) is useful in the detection of pancreatic carcinoma. One of its major limitations is the lack of specificity for malignancy, both for the primary tumor and for associated lymph nodes due to its inability to distinguish malignant infiltration from benign inflammation. EUS-guided fine needle aspiration (FNA) has now been developed, which allows for a tissue diagnosis of the primary tumor as well as lymph nodes, liver metastasis, and peritoneal/pleural fluid. The addition of EUS-guided FNA, with the specificity of a tissue diagnosis, to the high sensitivity and vascular assessment of EUS alone makes this the modality of choice for the diagnosis and staging of pancreatic carcinoma. The results of preliminary studies along with discussion regarding the technique, safety, cytologic adequacy, diagnostic accuracy, clinical utility, and future trends of EUS-guided FNA in pancreatic tumors are presented.

The efficacy of endoscopic treatment of pancreatic pseudocysts

BACKGROUND

Endoscopic drainage of pancreatic pseudocysts is a new nonsurgical treatment modality. We retrospectively studied the efficacy of endoscopic drainage of pseudocysts in 37 patients with chronic pancreatitis.

METHODS

Endoscopic retrograde pancreatic drainage was performed in 12 patients, endoscopic cystogastrostomy in 10 patients, and endoscopic cystoduodenostomy in 7 patients. In the remaining 8 patients, combinations of drainage routes were used.

RESULTS

ECG failed in 3 patients. Procedure-related complications were seen in 6 patients: bleeding in 3, perforation in 2, and apnea in 1 patient. There was no procedure-related mortality. Seven patients had complications in relation to stents or drains: pseudocyst infection due to stent clogging in 2, stent migration in 4, and kinking of the drain in 1 patient. Twenty-four patients had complete resolution of pseudocysts, 7 had partial resolution, and 6 had no resolution. Three patients had pseudocyst recurrences. Mean follow-up was 32 months. Finally, 10 patients underwent surgery.

CONCLUSIONS

Endoscopic drainage was technically feasible in 92% of the patients. Procedure-related morbidity was 16% and mortality was 0%. Endoscopic drainage was a definitive treatment for two thirds of the patients (65%). Surgery can be reserved for those patients in whom endoscopic therapy fails.

Transpapillary and transmural drainage of pancreatic pseudocysts

BACKGROUND

Endoscopic drainage of pseudocysts using the transpapillary and transmural approaches has been reported. We evaluated endoscopic drainage in 53 patients with symptomatic pancreatic pseudocysts in whom conservative management had failed.

METHODS

After preliminary endoscopic retrograde pancreatography, transpapillary drainage was attempted in 33 patients with pseudocysts that communicated with the main pancreatic duct. Transmural drainage of pseudocysts in contact with the stomach or duodenal wall was attempted in the remaining 20 patients and in 4 patients selected for combined transpapillary and transmural drainage. The cause of pseudocysts was chronic pancreatitis in 92%. The median pseudocyst size was 7.0 cm (range, 2 to 16).

RESULTS

Endoscopic drainage was technically successful in 50 patients (94%), of whom 47 had complete pseudocyst resolution. Complications occurred in 11% and included gallbladder puncture (n = 1) and bleeding (n = 2) after transmural drainage, and pancreatitis (n = 1) after transpapillary drainage; stent clogging resulted in abscess formation in 2 patients. Mean follow-up was 22 months (range, 1 to 70); pseudocysts recurred in 11 patients (23%), of whom 7 were successfully re-treated endoscopically.

CONCLUSION

Both transpapillary and transmural pseudocyst drainage are highly effective in patients with pseudocysts demonstrating suitable anatomy for these endoscopic techniques.

Current endosonographic possibilities in the upper gastrointestinal tract

Almost 15 years after its introduction endosonography is an important technique in a wide range of gastrointestinal diseases. Two types of dedicated echoendoscopes are commercially available each with their own advantages. Thinner instruments with higher resolutions, that will go through a normal endoscope are currently in development. With these probes differentiation between T1 and T in situ will be possible in the near future. Characterization of 'submucosal' lesions in the upper gastrointestinal tract is a field in which ES is the most reliable technique for determining the origin of these lesions. Also submucosal vessels are easily visualized and ES is acquiring an important role in the investigation of portal hypertension. ES is the most accurate staging technique for oesophageal and gastric carcinoma as well as for gastric lymphoma. T- and N-staging results are superior to CT scanning, although ES is not very reliable in individual lymph nodes. Therefore a lot of effort is put into obtaining cytological samples from lesions outside the gastrointestinal tract. It is now possible to get cytological proof of mediastinal lymph nodes through ES-guided fine needle aspiration biopsy. It seems that low grade malignant gastric lymphomas show a typical picture on ES, which may help in selecting treatment. The future will bring us higher resolution images and three-dimensional reconstruction is already being investigated. This last technique will probably become a standard preoperative investigation in oesophageal carcinoma before the century is over.