Todd Baron

Early ERCP practice at UAB

In the iGIE interview, Baron recalled completing approximately 135 ERCP procedures during his year at Duke and remaining concerned about beginning independent practice. He and his wife constructed a home training model from polyvinyl-chloride pipe, a plastic infant-feeding bottle, and tubing arranged to simulate the biliary and pancreatic orifices. Using a borrowed fiber-optic duodenoscope, he practiced cannulation on the model for approximately two hours per day before returning to UAB.

Baron established UAB's ERCP service while also covering inpatient, consultation, clinic, and Veterans Affairs responsibilities. UAB did not initially have a dedicated gastrointestinal fluoroscopy suite, so the service used a radiology fluoroscopy room after the day's diagnostic studies had finished. Baron recalled processing fluoroscopic films himself during complex cases because the endoscopy service did not have a dedicated radiologic technologist. He described these circumstances as contributing to a largely self-directed early practice in therapeutic ERCP.

Transition to therapeutic EUS

Baron attributed his decision to retrain in EUS to a 2012 live-endoscopy course in Rome. There he observed an EUS-guided choledochoduodenostomy performed with an electrocautery-enhanced lumen-apposing metal stent in a patient with combined duodenal and biliary obstruction. He later wrote that the demonstration made clear that therapeutic EUS would become increasingly important to pancreaticobiliary practice.

After an initial period observing EUS at the Asian Institute of Gastroenterology in Hyderabad, Baron trained with Mohan Ramchandani and Sundeep Lakhtakia in 2013. As part of his move from Mayo Clinic to UNC, he negotiated three additional months for intensive diagnostic EUS training with Laurent Palazzo in Paris. Baron said he deliberately emphasized diagnostic interpretation before applying his existing experience with needles, guidewires, catheters, and stents to therapeutic EUS.

Writing and documentation

At UAB, Joel E. Richter taught Baron to organize clinical observations and prepare medical manuscripts. Baron subsequently concentrated much of his scholarship on initial technical experiences, case reports, and retrospective clinical series rather than randomized trials. The iGIE profile connects this approach to publications ranging from early pancreatic-necrosis treatment to later EUS-guided rescue procedures.

Baron also shared an office at UAB with Basil Hirschowitz, a developer of the flexible fiber-optic endoscope. In the interview, Baron recalled Hirschowitz emphasizing the importance of maintaining clinical databases so that new procedures and their outcomes would be documented rather than lost. Baron cited that lesson when discussing the value of preserving the history of endoscopic innovation.

Pancreatic necrosis

In the early 1990s, surgery and percutaneous radiologic drainage were the principal invasive treatments for pancreatic necrosis. While treating patients whose collections had initially been considered pseudocysts, Baron began using transgastric endoscopic access, plastic stents, and nasobiliary-tube irrigation to drain and debride mature necrotic collections. Working with radiologist Douglas Morgan, he used the term "organized pancreatic necrosis" for the delayed, encapsulated entity now generally called walled-off pancreatic necrosis. Their 1996 Gastroenterology series is described in the iGIE profile as the first published account of endoscopic therapy for the condition. Baron and Richard Kozarek later reviewed the development of the technique after two decades, by which time endoscopic approaches had become established components of multidisciplinary management.

Transrectal drainage of a diverticular abscess

Baron and Morgan reported endoscopic transrectal drainage in a patient with a diverticular abscess who was considered unable to tolerate surgery. The collection abutted the rectum but did not have a safe conventional percutaneous route. Using a flexible upper endoscope, Baron punctured the collection with a transbronchial aspiration needle, confirmed entry by aspirating pus and injecting contrast, passed a guidewire, dilated the tract, and placed a drainage catheter. The 1997 report was presented as the first endoscopic transrectal drainage of a diverticular abscess and anticipated later EUS-guided pelvic-collection drainage.

Enteral and colonic stenting

Before dedicated colonic stents were available in the United States, Baron adapted esophageal and tracheobronchial self-expanding metal stents to palliate malignant obstruction elsewhere in the gastrointestinal tract. His first colonic case involved obstruction from recurrent rectal cancer in a patient considered a poor candidate for an ostomy. The stent relieved the obstruction, after which Baron and collaborators assembled early series describing placement techniques, radiologic findings, and clinical outcomes. In the iGIE interview, Baron credited a colorectal-surgeon collaborator with suggesting the name "enteral Wallstent" for a device intended for use throughout the gastrointestinal lumen. That design became an early dedicated gastrointestinal stent platform.

Transduodenal gallbladder drainage

Baron and Mayo Clinic endosonographer Mark Topazian published the first reported endoscopic transduodenal gallbladder drainage in 2007. The patient had cholecystitis and unresectable hilar cholangiocarcinoma with pre-existing biliary metal stents, making transpapillary drainage difficult and leaving percutaneous drainage as the conventional alternative. The team used EUS-guided transduodenal access to internally drain the gallbladder. The report helped establish the conceptual basis for EUS-guided gallbladder drainage, which was later facilitated by lumen-apposing metal stents.

Drainage of an infected aortic aneurysm

In 2016 Baron and Eduardo Rodrigues-Pinto reported EUS-guided transesophageal drainage of an infected aneurysm after aortic stent-graft placement. The endoscope was used to access the para-aortic infected collection through the esophageal wall and establish internal drainage in a patient with limited conventional options. Baron presented the case at the World Cup of Endoscopy during Digestive Disease Week, where it won the competition. The iGIE profile used the case as an example of extending EUS-guided drainage beyond conventional gastrointestinal targets.

Later first-experience and rescue reports

The historical profile also highlighted reports in which Baron and collaborators adapted endoscopic access or EUS to unusual rescue situations. These included:

• Endoscopic resolution of Mirizzi syndrome by fragmenting an impacted cystic-duct stone and placing biliary stents.
• Description of a Wirsungocele, a cystic dilation of the intraduodenal portion of the main pancreatic duct.
• Endoscopic removal of necrotic splenic tissue through a transgastric tract.
• Endoscopic repair of a complete bile-duct transection using transpapillary cholangioperitoneoscopy to identify and bridge the disconnected duct.
• Intraperitoneal echoendoscopy to regain access and rescue a disrupted EUS-created gastrojejunal anastomosis.
• EUS-guided natural-orifice transluminal surgery to remove a toothpick embedded in the liver.
• EUS-guided creation of an ileocolonic anastomosis to bypass complete small-bowel obstruction.
• EUS-guided gastric-varix embolization using coils and a self-assembling peptide matrix.

The iGIE interview characterizes these reports as examples of Baron's emphasis on publishing initial technical experiences. Many were case reports or small series intended to demonstrate feasibility rather than comparative trials, a distinction noted in the profile itself.