John A. Ryan

5.6k citations

66 papers · 4.3k indexed · 2 hit papers · h-index 32

Impact in

Oncology top 1%
- Pancreatic and Hepatic Oncology Research
- Colorectal Cancer Surgical Treatments
Nephrology top 1%

Papers in

Oncology 27
- Pancreatic and Hepatic Oncology Research 21
Nephrology 7
- Parathyroid Disorders and Treatments 6

Co-authors: Patrick C. Freeny Josef E. Fischer L. William Traverso William M. Abbott Ronald M. Abel Richard A. Kozarek William Marks Thomas McC. Chesney
Journals: The American Journal of Surgery (26 papers)Radiology (3 papers)The Journal of Urology (3 papers)Annals of Surgery (3 papers)Gastroenterology (3 papers)
Partner nations: United States United Kingdom

In The Last Decade

John A. Ryan

64 papers receiving 3.9k citations

Hit Papers

align trajectories log scale

Catheter Complications in Total Parenteral Nutrition 1974 · 575 citations

What are hit papers?

Hit papers significantly outperform the citation benchmark for their cohort. A paper qualifies if any of the following hold:

it has ≥500 total citations;
it reaches ≥1.5× the top-1% citation threshold for papers in the same subfield and year (the threshold is the minimum needed to enter the top 1%, not the average within it);
it reaches the top citation threshold in at least one of its specific research topics.

1974 New England Journal of Medicine
1973 New England Journal of Medicine

Peers

Countries citing papers authored by John A. Ryan

Since Specialization

Citations

This map shows the geographic impact of John A. Ryan's research. It shows the number of citations coming from papers published by authors working in each country. You can also color the map by specialization and compare the number of citations received by John A. Ryan with the expected number of citations based on a country's size and research output (numbers larger than one mean the country cites John A. Ryan more than expected).

Fields of papers citing papers by John A. Ryan

Since Specialization

Physical SciencesHealth SciencesLife SciencesSocial Sciences

This network shows the impact of papers produced by John A. Ryan. Nodes represent research fields, and links connect fields that are likely to share authors. Colored nodes show fields that tend to cite the papers produced by John A. Ryan. The network helps show where John A. Ryan may publish in the future.

Co-authors

The 25 scholars most cited alongside John A. Ryan, linked wherever they have co-authored with each other. Click a name or a connecting line to browse the papers they share.

Border = papers with John A. Ryan Line = papers co-authored together John A. Ryan links everyone, so they are left out of the graph.

All Works

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20 of 20 papers shown

#	Work
1	Two-phase (low-dose) computed tomography is as effective as 4D-CT for identifying enlarged parathyroid glands International Journal of Surgery ·Michael J. Campbell, Muneeb leone, Adnan Alseidi, C. Craig Blackmore, John A. Ryan	2015	31
2	Extended Neoadjuvant Chemotherapy for Borderline Resectable Pancreatic Cancer Demonstrates Promising Postoperative Outcomes and Survival Annals of Surgical Oncology ·J. Bart Rose, Flavio G. Rocha, Adnan Alseidi, Thomas Biehl, Ravi Moonka, John A. Ryan, Bruce Lin, Vincent J. Picozzi, Scott Helton	2014	107
3	One-gland exploration for mediastinal parathyroid adenomas: cervical and thoracoscopic approaches The American Journal of Surgery ·Rasha Almutairi, Mark Hill, John A. Ryan	2005	14
4	Zollinger–Ellison syndrome caused by solitary gastrinoma blocking the pancreatic duct: Enucleation and pancreatic duct repair Surgery ·Clancy J. Clark, John A. Ryan	2005	3
5	Maximizing Outcomes While Minimizing Exploration in Hyperparathyroidism Using Localization Tests Archives of Surgery ·John A. Ryan	2004	18
6	Outcomes after resection of cholangiocellular carcinoma The American Journal of Surgery ·Jasmine Huang, Thomas Biehl, Weixu Yu, Шерзод Хуррамович Зулфиқоров, John A. Ryan	2004	27
7	Management and long-term follow-up of hepatic cysts The American Journal of Surgery ·Christine Z. Patterson, John A. Ryan, James H. Holmes, Roberto Magnisi, Weixu Yu, Muzzafer Mohammad Mir, Phillip Reeves	2001	75
8	Intraductal neoplasms of the pancreas The American Journal of Surgery ·L. William Traverso, Elizabeth A. Peralta, John A. Ryan, Richard A. Kozarek	1998	194
9	Efficacy of Selective Unilateral Exploration in Hyperparathyroidism Based on Localization Tests Archives of Surgery ·John A. Ryan	1997	70
10	Effectiveness and safety of 100 consecutive parathyroidectomies The American Journal of Surgery ·John A. Ryan, M.E. Flower	1997	14
11	Transpapillary stenting for pancreaticocutaneous fistulas Journal of Gastrointestinal Surgery ·Richard A. Kozarek, Terrance J. Ball, David J. Patterson, Shirley L. Raltz, L. William Traverso, John A. Ryan, Richard C. Thirlby	1997	46
12	Pancreatitis caused by a gastric duplication communicating with an aberrant pancreatic lobe Journal of Pediatric Surgery ·R. Lawrence Moss, John A. Ryan, Richard A. Kozarek, Edwin I. Hatch	1996	26
13	Granular Cell Tumor of the Thyroid Gland in a Girl Receiving High-Dose Estrogen Therapy Pediatric Pathology & Laboratory Medicine ·C. Patrick Mahoney, Susan D. Patterson, John A. Ryan	1995	21
14	Serous cystadenoma of the pancreas with a metachronous adenocarcinoma. American Journal of Roentgenology ·Li DeGang, Patrick C. Freeny, Лиознер Владимир Львович, John A. Ryan	1994	12
15	Endoscopic retrograde cholangiopancreatography after laparoscopic cholecystectomy The American Journal of Surgery ·주미영, Richard A. Kozarek, 张凯, John J. Brandabur, Bernard Wilets, Philip C. Jolly, David J. Patterson, John A. Ryan, Richard C. Thirlby, Debra G. Wechter	1993	51
16	Diagnosis and staging of pancreatic adenocarcinoma with dynamic computed tomography The American Journal of Surgery ·Patrick C. Freeny, L. William Traverso, John A. Ryan	1993	191
17	Role of surgery in multimodality therapy for gastrointestinal lymphoma The American Journal of Surgery ·Ahmad AbdallahNahi, Richard C. Thirlby, John A. Ryan	1991	70
18	Management of enterovesical fistulas The American Journal of Surgery ·Richard L. Moss, John A. Ryan	1990	33
19	Infected pancreatic fluid collections: percutaneous catheter drainage. Radiology ·Patrick C. Freeny, G P Lewis, L. William Traverso, John A. Ryan	1988	100
20	Nd-YAG Laser Photoablation of Sessile Villous and Tubular Adenomas of the Colorectum Annals of Surgery ·Donald E. Low, Richard A. Kozarek, Neli Hermelinda, John A. Ryan	1988	12

About John A. Ryan

John A. Ryan is a scholar working on Oncology, Nephrology, Surgery, Hepatology and Pulmonary and Respiratory Medicine, having authored 66 papers that have together received 4.3k indexed citations. Recurring topics across this work include Pancreatic and Hepatic Oncology Research (21 papers), Pancreatitis Pathology and Treatment (12 papers), Gallbladder and Bile Duct Disorders (9 papers), Clinical Nutrition and Gastroenterology (8 papers), Parathyroid Disorders and Treatments (6 papers), Pediatric Hepatobiliary Diseases and Treatments (6 papers), Cholangiocarcinoma and Gallbladder Cancer Studies (5 papers) and Hepatocellular Carcinoma Treatment and Prognosis (5 papers). The work is most often cited by research in Oncology (1.7k citations), Nephrology (421 citations), Emergency Medical Services (389 citations), Surgery (2.4k citations) and Nutrition and Dietetics (675 citations). John A. Ryan has collaborated with scholars based in United States and United Kingdom. Frequent co-authors include Patrick C. Freeny, Josef E. Fischer, L. William Traverso, William M. Abbott, Ronald M. Abel, Richard A. Kozarek, William Marks, Thomas McC. Chesney, RITA COLLEY and Cyrus C. Hopkins. Their work appears in journals such as The American Journal of Surgery, Radiology, The Journal of Urology, Annals of Surgery and Gastroenterology.

Rankless uses publication and citation data sourced from OpenAlex, an open and comprehensive bibliographic database. While OpenAlex provides broad and valuable coverage of the global research landscape, it—like all bibliographic datasets—has inherent limitations. These include incomplete records, variations in author disambiguation, differences in journal indexing, and delays in data updates. As a result, some metrics and network relationships displayed in Rankless may not fully capture the entirety of a scholar's output or impact.

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