Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where T. Ryan Heider is active.

Publication


Featured researches published by T. Ryan Heider.


Annals of Surgery | 2004

The Natural History of Pancreatitis-Induced Splenic Vein Thrombosis

T. Ryan Heider; Samreen Azeem; Joseph A. Galanko; Kevin E. Behrns

Objective:To determine the natural history of pancreatitis-induced splenic vein thrombosis with particular attention to the risk of gastric variceal hemorrhage. Summary Background Data:Previous studies have suggested that splenic vein thrombosis results in a high likelihood of gastric variceal bleeding and that splenectomy should be performed to prevent hemorrhage. Recent improvements in cross-sectional imaging have led to the identification of splenic vein thrombosis in patients with minimal symptoms. Our clinical experience suggested that gastric variceal bleeding in these patients was uncommon. Methods:A computerized index search from 1993 to 2002 for the medical records of patients with a diagnosis of pancreatitis was performed. Fifty-three patients with a diagnosis of pancreatitis and splenic vein thrombosis were identified. The medical records of these patients were reviewed, and follow-up was completed, including the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC-QLQ). Results:Gastrosplenic varices were identified in 41 patients (77%) with varices evident on computed tomography (CT) in 40 of 53 patients, on esophagogastroduodenoscopy (EGD) in 11 of 36 patients, and on both CT and EGD in 10 of 36 patients. This risk of variceal bleeding was 5% for patients with CT-identified varices and 18% for EGD-identified varices. Overall, only 2 patients (4%) had gastric variceal bleeding and required splenectomy. Functional quality of life was better than historical controls surgically treated for chronic pancreatitis. Conclusion:Gastric variceal bleeding from pancreatitis-induced splenic vein thrombosis occurs in only 4% of patients; therefore, routine splenectomy is not recommended.


Journal of Gastrointestinal Surgery | 2003

Fundoplication improves disordered esophageal motility

T. Ryan Heider; Kevin E. Behrns; Mark J. Koruda; Nicholas J. Shaheen; Tananchai A. Lucktong; Barbara H. Bradshaw; Timothy M. Farrell

Patients with gastroesophageal reflux disease (GERD) and disordered esophageal motility are at risk for postoperative dysphagia, and are often treated with partial (270-degree) fundoplication as a strategy to minimize postoperative swallowing difficulties. Complete (360-degree) fundoplication, however, may provide more effective and durable reflux protection over time. Recently we reported that postfundoplication dysphagia is uncommon, regardless of preoperative manometric status and type of fundoplication. To determine whether esophageal function improves after fundoplication, we measured postoperative motility in patients in whom disordered esophageal motility had been documented before fundoplication. Forty-eight of 262 patients who underwent laparoscopic fundoplication between 1995 and 2000 satisfied preoperative manometric criteria for disordered esophageal motility (distal esophageal peristaltic amplitude ≤30 mm Hg and/or peristaltic frequency ≤80%). Of these, 19 had preoperative manometric assessment at our facility and consented to repeat study. Fifteen (79%) of these patients had a complete fun-doplication and four (21%) had a partial fundoplication. Each patient underwent repeat four-channel esophageal manometry 29.5 ± 18.4 months (mean ± SD) after fundoplication. Distal esophageal peristaltic amplitude and peristaltic frequency were compared to preoperative data by paired t test. After fun-doplication, mean peristaltic amplitude in the distal esophagus increased by 47% (56.8 ± 30.9 mm Hg to 83.5 ± 36.5 mm Hg; P < 0.001) and peristaltic frequency improved by 33% (66.4 ± 28.7% to 87.6 ± 16.3%; P< 0.01). Normal esophageal motor function was present in 14 patients (74%) after fundoplication, whereas in five patients the esophageal motor function remained abnormal (2 improved, 1 worsened, and 2 remained unchanged). Three patients with preoperative peristaltic frequencies of 0%, 10%, and 20% improved to 84%, 88%, and 50%, respectively, after fundoplication. In most GERD patients with esophageal dysmotility, fundoplication improves the amplitude and frequency of esophageal peristalsis, suggesting refluxate has an etiologic role in motor dysfunction. These data, along with prior data showing that postoperative dysphagia is not common, imply that surgeons should apply complete fun-doplication liberally in patients with disordered preoperative esophageal motility.


Annals of Surgery | 2007

Ski Promotes Tumor Growth Through Abrogation of Transforming Growth Factor-β Signaling in Pancreatic Cancer

T. Ryan Heider; Suzanne Lyman; Robert Schoonhoven; Kevin E. Behrns

Objective:We hypothesized that human pancreatic cancer resists TGF-β signaling and cell death through increased Ski expression. Summary Background Data:Ski is an oncogenic protein that acts as a TGF-β repressor and prevents related gene transcription. Previous work suggests that Ski acts as an oncoprotein in melanoma and esophageal cancer. Ski expression and function have not been determined in human pancreatic cancer. Methods:Immunohistochemistry and immunoblots assessed Ski expression in human pancreatic cancer. Panc-1 cells were treated with or without Ski siRNA, and Ski and Smad protein expression, transcriptional reporter activation, and growth assays were determined. Panc-1 cells were inoculated in the flank of nude mice and tumor volume and histology assessed after administration of Ski siRNA or control vector. Results:Ski was abundantly expressed in human pancreatic cancer specimens assessed by immunohistochemistry (91%) and immunoblot analysis (67%). Panc-1 cells exhibited nascent Ski expression that was maximally inhibited 48 hours after transfection with Ski siRNA. TGF-β transcriptional activity was increased 2.5-fold in Ski siRNA-treated cells compared with control (P < 0.05). Ski siRNA increased TGF-β-induced Smad2 phosphorylation and p21 expression. Panc-1 growth in culture was decreased 2-fold at 72 hours. A Ski siRNA expression vector injected into nude mice resulted in a 5-fold decrease in growth. Conclusion:Inhibition of Ski through RNA interference restored TGF-β signaling and growth inhibition in vitro, and decreased tumor growth in vivo.


Journal of Gastrointestinal Surgery | 2006

Endoscopic sphincterotomy permits interval laparoscopic cholecystectomy in patients with moderately severe gallstone pancreatitis

T. Ryan Heider; Alphonso Brown; Ian S. Grimm; Kevin E. Behrns

Patients with moderately severe gallstone pancreatitis with substantial pancreatic and peripancreatic inflammation, but without organ failure, frequently have an open cholecystectomy to prevent recurrent pancreatitis. In these patients, prophylactic endoscopic retrograde cholangiography (ERC) with endoscopic sphincterotomy (ES) may prevent recurrent pancreatitis, permit laparoscopic cholecystectomy, and decrease risks. The medical records of all patients with pancreatitis undergoing cholecystectomy from 1999–2004 at the University of North Carolina Memorial Hospital were reviewed. Data regarding demographics, clinical course, etiology of pancreatitis, operative and endoscopic interventions, and outcome were extracted. Moderately severe gallstone-induced pancreatitis was defined as pancreatitis without organ failure but with extensive local inflammation. Thirty patients with moderately severe gallstone pancreatitis underwent ERC and ES and were discharged before cholecystectomy. Mean interval between ES and cholecystectomy was 102 ± 17 days. Cholecystectomy was performed laparoscopically in 27 (90%) patients, open in three (10%) patients, and converted to open in two (7%) patients, with a morbidity rate of 7% (two patients). No patient required drainage of a pseudocyst or developed recurrent pancreatitis. Interval complications resulted in hospital readmission in seven (23%) patients. In conclusion, recurrent biliary pancreatitis in patients with moderately severe gallstone pancreatitis is nil after ERC and ES. Hospital discharge of these patients permits interval laparoscopic cholecystectomy, but close follow-up is necessary in these potentially ill patients.


Journal of Burn Care & Rehabilitation | 2002

Eczema mimicking child abuse: a case of mistaken identity.

T. Ryan Heider; Diane Priolo; C. Scott Hultman; Michael D. Peck; Bruce A. Cairns

Many skin conditions can mimic child abuse by burning. Multidisciplinary evaluation of suspicious burns helps prevent both the underreporting and the misdiagnosis of child abuse by burning. We report a case of pediatric eczema mimicking an abusive burn.


Journal of Surgical Research | 2004

Molecular and cellular features of hepatic regeneration

Dalliah Mashon Black; Suzanne Lyman; T. Ryan Heider; Kevin E. Behrns


American Surgeon | 2004

Acute vagotomy does not augment the systemic inflammatory response in patients with peptic ulcer disease

T. Ryan Heider; Mark J. Koruda; Timothy M. Farrell; Kevin E. Behrns


Gastroenterology | 2000

Complete fundoplication is not associated with increased dysphagia in patients with abnormal esophageal motility

T. Ryan Heider; Timothy M. Farrell; S. Amanda Kircher; Mark J. Koruda; Craig Colliver; Kevin E. Behrns


Journal of The American College of Surgeons | 2004

Ski overexpression impairs TGF-B signaling and results in loss of growth control in human pancreatic cancer

T. Ryan Heider; Suzanne Lyman; Robert Schoonhoven; Kevin E. Behrns


Journal of Surgical Research | 2004

Molecular and cellular features of hepatic regeneration 1 1 This work was supported by National Inst

Dalliah Mashon Black; Suzanne Lyman; T. Ryan Heider; Kevin E. Behrns

Collaboration


Dive into the T. Ryan Heider's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar

Suzanne Lyman

University of North Carolina at Chapel Hill

View shared research outputs
Top Co-Authors

Avatar

Mark J. Koruda

University of North Carolina at Chapel Hill

View shared research outputs
Top Co-Authors

Avatar

Timothy M. Farrell

University of North Carolina at Chapel Hill

View shared research outputs
Top Co-Authors

Avatar

Dalliah Mashon Black

University of North Carolina at Chapel Hill

View shared research outputs
Top Co-Authors

Avatar

Robert Schoonhoven

University of North Carolina at Chapel Hill

View shared research outputs
Top Co-Authors

Avatar

Alphonso Brown

Beth Israel Deaconess Medical Center

View shared research outputs
Top Co-Authors

Avatar

Barbara H. Bradshaw

University of North Carolina at Chapel Hill

View shared research outputs
Top Co-Authors

Avatar

Bruce A. Cairns

University of North Carolina at Chapel Hill

View shared research outputs
Top Co-Authors

Avatar

C. Scott Hultman

University of North Carolina at Chapel Hill

View shared research outputs
Researchain Logo
Decentralizing Knowledge