A Defining Moment for Abdominal Surgery

What’s in a name? When it comes to extreme liver surgery and distal pancreatectomy, more than one would think.

Both areas of abdominal surgery have been transformed in recent years through the use of innovative technology and the development of minimally invasive surgical approaches. In order to develop evidence-based guidelines to apply these advanced techniques for the right patients, researchers need to be able to compare surgical outcomes across centers, countries and continents.

That’s where standardized terminology is required and why two international efforts called upon experts in their respective fields to participate in a Delphi consensus process to define left-sided pancreas resections and extreme liver surgery.

Antonio Pinna, MD, Director of the Abdominal Transplant Center and the Living Donor Liver Transplant Program at Cleveland Clinic Florida, was invited to participate in both. As a renowned transplant surgeon and prolific researcher, Dr. Pinna specializes in living donor liver transplantation, split liver transplantation, and liver transplant to treat hepatocellular cancer. He also has extensive experience in the surgical treatment of patients with pancreatic and biliary cancers.

Left-sided pancreatic resections

The first of the two Delphi consensuses published in 2024 addressed distal pancreatectomy, an overarching term used to describe a procedure for treating pancreatic body and tail diseases. The term actually refers to a group of left-sided pancreatic surgical procedures that vary greatly in the extent of resection.

“The pancreas is a long, flat organ,” describes Dr. Pinna. “Trying to compare surgical outcomes of a 3 cm resection of the pancreatic tail to a much more complex resection extending to the left of the superior mesenteric artery would not be enlightening even though both are considered a distal pancreatectomy.”

The prospective Delphi consensus study was initiated in September 2022 during the meeting of the Brescia Internationally Validated European Guidelines on Minimally Invasive Pancreatic Surgery (EGUMIPS). The meeting’s objective was to develop and update evidence- and consensus-based guidelines on laparoscopic and robotic pancreatic surgery.

EGUMIPS meeting attendees and expert representatives from participating medical societies were invited to take part in the Delphi survey process. Ultimately, input was captured from 86 experts in the field of pancreatic surgery, including five pancreatic radiologists, from 24 countries across four continents.

Following three Delphi rounds, a consensus on a new set of terminology for left-sided pancreatic resections was achieved by 78% of the respondents. “Standardizing definitions and terminology of left-sided pancreatic resections through an international Delphi consensus,” published last April in the British Journal of Surgery, outlined four resection categories based on anatomical borders:

• Pancreatic tail resection – to half the distance between the pancreatic tail edge and the superior mesenteric vein (SMV).
• Pancreatic body and tail resection – to the left border of the SMV.
• Pancreatic neck, body and tail resection – to the left border of the gastroduodenal artery (GDA).
• Extended pancreatic neck, body and tail resection – to the right of the GDA.

The consensus document also provided specifications for surgical reporting that included approach – open, laparoscopic or robotic – and the addition of other concomitant resections (i.e. spleen, multivisceral). “These details can affect surgical outcomes and are needed for properly comparing procedures,” explains Dr. Pinna.

Extreme liver surgery

The second Delphi consensus, also issued last year, was the first international effort to focus on the definition of extreme liver surgery.

“The term has been used for decades but without a standardized criteria for what it entails, its indications, outcomes and approaches,” says Dr. Pinna. “Our goal with this consensus is to improve the overall management of patients with highly complex hepatobiliary oncological disease.”

He was one of 51 experts in complex hepatobiliary surgery selected to participate in the two-round Delphi study. The first round was completed by 41 respondents from 18 countries on 3 continents, while 38 surgeons completed the second round.

The proposed definition for extreme liver surgery was ultimately agreed upon by 75% of the experts. As part of “Harmonizing Definitions and Perspectives in Extreme Liver Surgery: A Delphi Experts Consensus,” published in June in the Annals of Surgery, it specified that patients undergoing extreme liver surgery should meet at least two of the following criteria:

1. Need for an ex situ, ante situ or in situ approach with or without hypothermic perfusion or normothermic machine perfusion.
2. Vascular resection with reconstruction.
3. Liver resection outside the established anatomical boundaries.
4. Future borderline liver remnant.

In addition to providing a clear definition for extreme liver surgery, the expert panel addressed vascular occlusion concepts, preferred surgical approaches, patient profile and indications, perioperative outcomes, and vascular graft selection.

For example, during extreme liver surgeries requiring total vascular occlusion (TVE), “83% of the experts advise liver perfusion with a preservation solution,” and “89% agree that the maximum ischemia time without using hypothermic perfusion should not exceed 45-60 minutes.”

In a show of unity, 100% of respondents agreed that the surgical expertise of the surgeon combined with the possibility to offer liver transplantation in case of unexpected challenges should influence the decision to perform an extreme liver surgery.

Dr. Pinna notes that more patients are deemed to have resectable disease as a result of treatment advancements. Likewise, more centers are performing complex liver surgery for hepatic tumors that involve extensive hepatectomies and intricate vascular reconstructions.

“Now more than ever we need to have a standardized nomenclature and protocols,” he states. “The consensus document on extreme liver surgery provides best practices for surgeons who want to build experience and criteria for hospitals to be eligible to provide this level of care.”

Looking ahead

Dr. Pinna estimates it may take up to five years for both Delphi consensuses to take hold and have an impact. “Researchers will need to adopt the new terminology and surgical reporting guidelines for left-sided pancreatic resections, and journal reviewers will need to require authors to use them,” he says.

In the case of extreme liver surgery, Dr. Pinna and the consensus authors recommend oncologic surgery departments use the consensus document to create clinical guidelines and standardized protocols or to refer patients to specialized centers that perform this type of surgery.