Comparison of Kimura Versus Warshaw Technique for Laparoscopic Spleen-Preserving Distal Pancreatectomy

Comparison of Kimura Versus Warshaw Technique for Laparoscopic Spleen-Preserving Distal Pancreatectomy: A Multicenter Randomized Controlled Clinical Trial

This study aims to compare the surgical outcomes of laparoscopic spleen-preserving distal pancreatectomy using the Kimura technique versus the Warshaw technique. The primary focus is on the rates of unplanned splenectomy, occurrence of severe complications, as well as intraoperative and perioperative outcomes of both techniques.

For benign and low-grade malignant tumors of the pancreatic body and tail, laparoscopic distal pancreatosplenectomy (LDP) is commonly recommended due to its shorter hospital stay, lower intraoperative blood loss, and comparable complication rates. The DIPLOMA international multicenter clinical trial further established the non-inferiority of minimally invasive techniques in terms of curative resection for resectable pancreatic body and tail cancers.

As the spleen plays a crucial role in immune defense, splenectomy is associated with increased postoperative infection risk, significant increase in platelet count, and thrombosis. Therefore, for benign and low-grade malignant tumors of the pancreatic body and tail, minimally invasive spleen-preserving distal pancreatectomy should be the preferred approach.

The Kimura technique is the most commonly used and favored spleen-preserving distal pancreatectomy technique. It involves the complete preservation of splenic vessels, resulting in fewer postoperative complications. However, it is time-consuming and challenging due to the identification and ligation of numerous small and short vessels entering the pancreatic body and tail to preserve the fragile splenic artery and vein. On the other hand, the Warshaw technique involves segmental resection of splenic vessels and relies on the left gastroepiploic artery and short gastric vessels for splenic perfusion. It is a simpler procedure with less intraoperative blood loss and shorter operative time. However, it carries an increased risk of postoperative splenic infarction, gastric varices, and secondary bleeding.

Although a higher incidence of splenic infarction has been observed with the Warshaw technique, its clinical relevance remains controversial. Reports indicate that approximately 25% of patients undergoing Warshaw procedure show radiological evidence of asymptomatic gastric varices, but during a follow-up period of up to 21 years, no clinically relevant consequences of gastric varices were observed. Most cases of postoperative splenic infarction are transient and do not require specific treatment. Data from a large pan-European retrospective study showed no significant differences in the clinical incidence of splenic infarction (0.6% vs. 1.6%, P = 0.127) and major complication rates (11.5% vs. 14.4%, P = 0.308) between minimally invasive Kimura and Warshaw techniques.

While Kimura and Warshaw techniques demonstrate comparability in most postoperative outcomes, the former appears to have an advantage in reducing the risk of splenic infarction and gastric varices. Some experts propose a "Kimura-first" strategy. However, there is currently no prospective study comparing these two techniques. Therefore, this study has designed a multicenter randomized controlled clinical trial, focusing on the rates of unplanned splenectomy, severe complication occurrence, and intraoperative and perioperative outcomes of laparoscopic spleen-preserving distal pancreatectomy using the Kimura versus the Warshaw technique. Long-term follow-up will assess clinically relevant outcomes such as splenic ischemia, splenic hyperfunction, gastric varices, and postoperative quality of life. This study aims to provide higher-level evidence in the selection of laparoscopic spleen-preserving distal pancreatectomy techniques.

Inclusion Criteria:

• Age between 18 and 70 years, regardless of gender.
• Preoperative clinical diagnosis of benign or low-grade malignant pancreatic tumors.
• Meeting the recommended surgical indications as per guidelines.
• Feasibility of imaging assessment for either Kimura or Warshaw technique laparoscopic spleen-preserving distal pancreatectomy.
• Performance status of 0 or 1 according to the Eastern Cooperative Oncology Group (ECOG) score.
• Willingness to comply with the study treatment plan, follow-up schedule, and other protocol requirements.
• Voluntarily participating in the study and signing an informed consent form.

Exclusion Criteria:

• Body Mass Index (BMI) > 28 kg/m2 (Chinese obesity standard).
• History of blood disorders, acute or chronic pancreatitis, gastrointestinal bleeding, splenic rupture, or gastric varices (preoperative CT indicating curved vessel structures along the gastric wall with a diameter > 5mm).
• History of abdominal surgery.
• Concomitant primary malignant tumors.
• Suspicion of malignancy based on PET-CT or other imaging examinations.
• Severe impairment of cardiac, liver, or kidney function (NYHA class 3-4, ALT and/or AST exceeding three times the upper limit of normal, Creatinine exceeding the upper limit of normal).
• Planned pregnancy or pregnancy and lactating women.
• Participants currently involved in other clinical trials.