Intraoperative Imaging for Gastrointestinal Surgery
Intraoperative ultrasound (IOUS) is the primary recommended imaging modality during hepatic and pancreatic surgery, providing real-time guidance for tumor localization, staging, and surgical decision-making. 1, 2, 3
Hepatopancreatobiliary Surgery
Intraoperative Ultrasound (IOUS)
IOUS serves as the cornerstone of intraoperative imaging for liver and pancreatic procedures, offering critical advantages:
- Tumor detection and staging: IOUS identifies lesions not visible on preoperative imaging and detects additional tumors that alter surgical planning 2, 3
- Real-time guidance: Provides immediate feedback for resection margins, vascular anatomy identification, and precise surgical maneuvers 2
- Both open and laparoscopic applications: Equally effective in traditional open surgery and minimally invasive laparoscopic procedures (LUS - laparoscopic ultrasound) 3
The technique is well-established with 25+ years of clinical experience and should be considered standard practice for hepatobiliary and pancreatic tumor resections 3.
ICG Fluorescence Imaging
Indocyanine green (ICG) fluorescence imaging is increasingly valuable for real-time perfusion assessment during hepatopancreatobiliary surgery with vascular reconstruction. 4
Key applications include:
- Vascular perfusion assessment: Real-time visualization of blood flow through anastomotic sites after vascular reconstruction 4
- Hepatic segmentation: Identifies hepatic tumor margins and guides anatomic resections 1, 4
- Biliary anatomy visualization: Maps biliary structures to prevent inadvertent injury 1
In a 2025 study of 30 patients undergoing hepatectomies and pancreatectomies with vascular reconstruction, ICG fluorescence imaging successfully guided intraoperative decision-making in 53% of cases, including determining the necessity of middle hepatic vein reconstruction and confirming adequate blood flow through anastomoses 4.
Dosing: 1.25-5 mg IV administered intraoperatively 4
Emerging Modalities
While photoacoustic imaging and 3D holographic guidance show promise, these remain largely in preclinical development and are not yet ready for routine clinical implementation 1, 5.
Bariatric Surgery
For bariatric procedures, routine intraoperative imaging is NOT recommended. 6
The 2025 ACR Appropriateness Criteria explicitly state there is no relevant literature supporting routine intraoperative imaging during bariatric procedures 6. The focus for bariatric surgery is on:
- Selective postoperative imaging: Reserved for symptomatic patients or those at high risk for complications (staple-line leak, hemorrhage, obstruction) 6
- Surgeon discretion: The American Society for Metabolic & Bariatric Surgery (ASMBS) recommends that decisions about routine versus selective postoperative imaging be left to individual surgeon judgment 6
Important Caveat
The evidence provided focuses heavily on pre- and postoperative imaging for bariatric procedures rather than intraoperative techniques. The absence of literature supporting intraoperative imaging in bariatric surgery reflects current practice patterns where direct visualization during laparoscopy is typically sufficient 6.
Practical Algorithm for Hepatopancreatobiliary Surgery
Standard approach: Use IOUS at the beginning of every hepatic or pancreatic resection to:
When vascular reconstruction is planned or considered: Add ICG fluorescence imaging (1.25-5 mg IV) to:
- Assess perfusion of organs/segments before deciding on reconstruction necessity
- Confirm adequate blood flow through anastomoses immediately after reconstruction
- Verify perfusion of target organs 4
For biliary procedures: Consider ICG fluorescence for biliary anatomy mapping, particularly in complex cases or when anatomy is unclear 1
This multimodal approach combining IOUS as the foundation with selective ICG fluorescence imaging optimizes surgical outcomes by reducing positive margin rates and preventing vascular complications 1, 2, 3, 4.