Catheter Redosing of Autonomic Neural Blockade After Sleeve Gastrectomy

Targeted Temporary In Situ Catheter Redosing of Autonomic Neural Blockade for Breakthrough Symptoms After Laparoscopic Sleeve Gastrectomy

Postoperative visceral pain and autonomic symptoms after laparoscopic sleeve gastrectomy may reappear earlier in selected high-risk patients despite standard intraoperative autonomic neural blockade (ANB). Temporary in situ catheter placement permits postoperative ANB redosing when breakthrough visceral symptoms occur.

This prospective single-arm observational study will evaluate the feasibility, safety, and clinical effectiveness of temporary ANB catheter placement and selective postoperative redosing in high-risk patients undergoing laparoscopic sleeve gastrectomy.

Autonomic neural blockade (ANB) selectively modulates visceral pain and autonomic symptoms after minimally invasive upper gastrointestinal surgery. Prior randomized trials have demonstrated reductions in pain, analgesic requirements, PONV, and anesthetic consumption following ANB during laparoscopic sleeve gastrectomy (LSG). However, breakthrough visceral symptoms may occur in selected patients after blockade wanes.

A prior feasibility study by our group demonstrated that temporary in situ catheter placement for postoperative ANB redosing after LSG is technically feasible and safe, establishing catheter selection, placement strategy, and anatomical targets.

This prospective pilot study evaluates the clinical utility of selective postoperative ANB redosing in predefined high-risk patients.

All participants will undergo standard intraoperative ANB, TAP block, and temporary catheter placement in one of three anatomically validated paragastric/celiac pathway locations. Scheduled acetaminophen will be administered postoperatively.

Prior to any redosing, the treating investigator will clinically assess whether symptoms are consistent with visceral/autonomic breakthrough rather than somatic/incisional pain. Pain characteristics suggesting visceral origin include diffuse, deep, poorly localized epigastric/substernal discomfort, associated nausea/vomiting, autonomic symptoms, or pain disproportionate to abdominal wall tenderness.

Patients meeting redosing criteria will receive catheter redosing with 15 mL of 0.5% bupivacaine plus 4 mg dexamethasone. The minimum interval between re-dosing will be eight hours.

Concomitant hiatal hernia repair will be recorded for all patients, given the potential influence of distal phrenic nerve blockade on postoperative symptom patterns.

Inclusion Criteria:

Patients undergoing elective laparoscopic sleeve gastrectomy with one or more of the following risk factors for breakthrough visceral/autonomic symptoms:

• Female sex age <30 years
• Prior history of severe postoperative pain after abdominal surgery
• Prior history of significant postoperative nausea/vomiting
• History of opioid intolerance or significant opioid-related adverse effects
• Allergy/intolerance to multiple postoperative analgesics/antiemetics
• Concomitant hiatal hernia repair
• Surgeon's judgment of elevated visceral symptom risk based on prior institutional experience

Exclusion Criteria:•

• Contraindication to local anesthetics or dexamethasone
• Chronic opioid dependence
• Severe psychiatric or cognitive impairment limiting symptom assessment
• Pregnancy
• Conversion to open surgery
• Inability or unwillingness to comply with the postoperative reporting protocol.