Publications by authors named "John A Ryan"
Background: Four-dimensional computed tomography (4D-CT) is often used for patients with primary hyperparathyroidism and non-definitive localization after Sestamibi scan (MIBI) and ultrasound (US), but may expose patients to unnecessary radiation, typically between 10 and 26 millisieverts (mSv). We hypothesize that a simpler two-phase CT protocol would have a similar sensitivity, specificity and accuracy to those published for 4D-CT, while exposing the patient to less radiation.
Methods: We reviewed 54 patients with primary hyperparathyroidism and non-definitive localization studies who had a two-phase CT between 2009 and 2012 at our tertiary referral center.
Background: The optimum approach to neoadjuvant therapy for patients with borderline resectable pancreatic cancer is undefined. Herein we report the outcomes of an extended neoadjuvant chemotherapy regimen in patients presenting with borderline resectable adenocarcinoma of the pancreatic head.
Methods: Patients identified as having borderline resectable pancreatic head cancer by American Hepato-Pancreato-Biliary Association/Society of Surgical Oncology consensus criteria from 2008 to 2012 were tracked in a prospectively maintained registry.
Importance: This is the largest series to date comparing end-to-side biliary reconstruction for all indications performed using either the duodenum or jejunum and with at least 2-year follow-up.
Objective: To demonstrate that duodenal anastomoses for biliary reconstruction are at least as safe and effective as Roux-en-Y jejunal anastomoses, with the benefits of operative simplicity and ease of postoperative endoscopic evaluation.
Design, Setting, And Participants: Retrospective record review with telephone survey of patients undergoing nonpalliative biliary reconstruction in the hepatopancreatobiliary surgery division of a high-volume tertiary care facility.
Background: In patients with sporadic primary hyperparathyroidism, preoperative localization studies may discover a solitary mediastinal parathyroid adenoma. In this circumstance a 1-gland mediastinal exploration, either cervical or thoracoscopic, may be curative.
Methods: In an 18-month period, 5 of 120 consecutive patients underwent an initial 1-gland mediastinal exploration for a solitary mediastinal parathyroid adenoma and 2 patients had a 1-gland mediastinal exploration for persistent hyperparathyroidism.
Hypothesis: Preoperative localization (ultrasonography and scintigraphy) can be used to limit operative exploration in primary hyperparathyroidism while providing a high rate of success.
Design: Prospective cohort analysis of 3 types of exploration (1-gland, unilateral, or 4-gland), as directed by localization.
Results: In 185 consecutive patients who underwent operations, the final diagnoses were solitary adenoma in 87% and multigland disease in 13%.
Background: Cholangiocellular carcinoma (CCC) is a rare primary liver malignancy that arises from intrahepatic bile duct canaliculi and presents as a liver mass. Our purpose is to report operative morbidity and mortality and to determine long-term survival after resection for CCC.
Methods: Retrospective review of 31 consecutive patients who underwent resection during a 20-year period.
Hypothesis: The surgical treatment of primary hyperparathyroidism results in an improved health-related quality of life.
Design: Prospective cohort analysis of consecutive patients with primary hyperparathyroidism analyzed preoperatively and 1 year postoperatively.
Setting: Academic multispecialty referral clinic.
Hypothesis: Normal biliary function can be achieved after reconstruction for major bile duct injuries using either hepaticoduodenostomy (HD) or Roux-en-Y hepaticojejunostomy (HJ).
Design: Retrospective analysis of consecutive patients requiring biliary enteric reconstructions from February 1, 1993, through January 1, 2002, for bile duct injuries.
Setting: Academic multispecialty referral clinic.