Peter Kingham

Percutaneous Ablation of Peribiliary Tumors with Irreversible Electroporation

PURPOSE To assess biliary complications after irreversible electroporation (IRE) ablation of hepatic tumors located < 1 cm from major bile ducts. MATERIALS AND METHODS A retrospective review was conducted of all percutaneous IRE ablations of hepatic tumors within 1 cm of the common, left, or right hepatic ducts at a single institution from January 2011 to September 2012. Computed tomography imaging performed before and after treatment was examined for evidence of bile duct dilatation, stricture, or leakage. Serum bilirubin and alkaline phosphatase levels were analyzed for evidence of biliary injury. RESULTS There were 22 hepatic metastases in 11 patients with at least one tumor within 1 cm of the common, left, or right hepatic duct that were treated with IRE ablations in 15 sessions. Median tumor size treated was 3.0 cm (mean, 2.8 cm ± 1.2, range, 1.0-4.7 cm). Laboratory values obtained after IRE were considered abnormal after four treatment sessions in three patients (bilirubin, 2.6-17.6 mg/dL; alkaline phosphatase, 130-1,035 U/L); these abnormal values were transient in two sessions. Two patients had prolonged elevation of values, and one required stent placement; both of these conditions appeared to be secondary to tumor progression rather than bile duct injury. CONCLUSIONS This clinical experience suggests that IRE may be a treatment option for centrally located liver tumors with margins adjacent to major bile ducts where thermal ablation techniques are contraindicated. Further studies with extended follow-up periods are necessary to establish the safety profile of IRE in this setting.

Endoscopic Ultrasound-Guided Transmural Drainage of Postoperative Pancreatic Collections

BACKGROUND Pancreatic leak is a major cause of morbidity after pancreatectomy. Traditionally, peripancreatic fluid collections have been managed by percutaneous or operative drainage. Data for endoscopic ultrasound (EUS)-guided drainage of postoperative fluid collections are limited. Here we report on the safety, efficacy, and timing of EUS-guided drainage of postoperative peripancreatic collections. STUDY DESIGN This is a retrospective review of 31 patients who underwent EUS-guided drainage of fluid collections after pancreatic resection. Technical success was defined as successful transgastric deployment of at least one double pigtail plastic stent. Clinical success was defined as resolution of the fluid collection on follow-up CT scan and resolution of symptoms. Early drainage was defined as initial transmural stent placement within 30 days after surgery. RESULTS Endoscopic ultrasound-guided drainage was performed effectively with a technical success rate of 100%. Clinical success was achieved in 29 of 31 patients (93%). Nineteen of the 29 patients (65%) had complete resolution of their symptoms and collection with the first endoscopic procedure. Repeat drainage procedures, including some with necrosectomy, were required in the remaining 10 patients, with eventual resolution of collection and symptoms. Two patients who did not achieve durable clinical success required percutaneous drainage by interventional radiology. Seventeen (55%) of 31 patients had successful early drainage completed within 30 days of their operation. CONCLUSIONS Endoscopic ultrasound-guided drainage of fluid collections after pancreatic resection is safe and effective. Early drainage (<30 days) of postoperative pancreatic fluid collections was not associated with increased complications in this series.

Gene Expression Profiles Accurately Predict Outcome Following Liver Resection in Patients with Metastatic Colorectal Cancer

Purpose The aim of this study was to build a molecular prognostic model based on gene signatures for patients with completely resected hepatic metastases from colorectal cancer (MCRC). Methods Using the Illumina HumanHT-12 gene chip, RNA samples from the liver metastases of 96 patients who underwent R0 liver resection were analyzed. Patients were randomly assigned to a training (n = 60) and test (n = 36) set. The genes associated with disease-specific survival (DSS) and liver-recurrence-free survival (LRFS) were identified by Cox-regression and selected to construct a molecular risk score (MRS) using the supervised principle component method on the training set. The MRS was then evaluated in the independent test set. Results Nineteen and 115 genes were selected to construct the MRS for DSS and LRFS, respectively. Each MRS was validated in the test set; 3-year DSS/LRFS rates were 42/32% and 79/80% for patients with high and low MRS, respectively (p = 0.007 for DSS and p = 0.046 for LRFS). In a multivariate model controlling for a previously validated clinical risk score (CRS), the MRS remained a significant predictor of DSS (p = 0.001) and LRFS (p = 0.03). When CRS and MRS were combined, the patients were discriminated better with 3-year DSS/LRFS rates of 90/89% in the low risk group (both risk scores low) vs 42/26% in the high risk group (both risk scores high), respectively (p = 0.002/0.004 for DSS/LRFS). Conclusion MRS based on gene expression profiling has high prognostic value and is independent of CRS. This finding provides a potential strategy for better risk-stratification of patients with liver MCRC.

Resection of perihilar biliary schwannoma

INTRODUCTION Schwannomas are usually benign nerve sheath tumors, which typically arise in the head, neck, spinal cord and extremities. Schwannoma of the biliary tract is an extremely rare finding. Patients generally lack symptoms and seek medical attention when tumor growth causes obstructive jaundice. Preoperative diagnosis is difficult and resection is the treatment of choice. METHODS A 54 year-old female with history of back and right labia minor melanoma for which she underwent complete excision and right inguinal lymph node dissection more than 10 years ago, was evaluated for new onset gastroesophageal reflux symptoms and found to have markedly abnormal liver enzymes. Imagining studies revealed intrahepatic ductal dilatation and a 5.2 cm mass in the porta hepatis that was not consistent with cholangiocarcinoma or hepatocellular carcinoma. Multiple percutaneous biopsies of the mass failed to provide a definitive diagnosis. With a high clinical suspicion of metastatic melanoma and no other evident sites of disease, operative intervention was undertaken for diagnosis and definitive treatment. RESULTS Diagnostic laparoscopy was performed initially, but access to the mass was difficult, given its location. Subsequently, the patient underwent laparotomy, with tumor excision, common bile duct resection and hepato-jejunostomy. Pathologic examination and analysis were consistent with cellular schwannoma. Postoperatively, the patient recovered uneventfully, and liver function studies returned to normal. CONCLUSION Schwannomas are uncommon tumors, which very rarely arise from the biliary tract and cause biliary obstruction. Exploration is indicated in order to establish the diagnosis and to render definitive treatment.