1. Intraoperative US of the Liver: Techniques and Clinical Applications
Intern 盧佳文

2. Outline Introduction Applications of Intraoperative US of the Liver
Clinical Role of Intraoperative US

3. Introduction Transducer Requirements Transducer Sterilization
Technique for US of the Liver
Relevant Intraoperative Anatomy
Artifact

4. Transducer Requirements
5-MHz side-fire T-shaped linear- or curvilineararray
transducer
fit comfortably against the palm of the hand and
between the fingers
have color Doppler flow and pulsed Doppler
provide good near-field resolution

5. Transducer Sterilization
Sterile condom sheaths
most commonly
The sheath must be long (typically about 1.5 m)
fit snugly around the transducer to avoid artifacts
Low-temperature hydrogen peroxide gas plasma sterilization techniques
an entire sterilization cycle in 2–3 hours,
safe to use with heat-sensitive equipment,
enable the use of a sterile transducer without a condom sheath
Glutaraldehyde or dialdehyde solution
Ethylene oxide gas sterilization with high-temperature eratio

6. Technique for US of the Liver
Basic setting
Technique
in a transverse position, starting at the most lateral margin of the left lateral segment II and extending toward the right side

7. Technique
bathing the field with sterile saline for very near lesion

8. Relevant Intraoperative Anatomy
Hepatic vein
the transducer is held in a transverse midline position and angled toward the beating heart
Portal vein
Placing the transducer on the undersurface of the liver, over segment IV, and angling the transducer toward the porta hepatis

9. Relevant Intraoperative Anatomy
Specific arteries
a replaced right hepatic artery that arises from the superior mesenteric artery and courses posterior to the portal vein
replaced or accessory left hepatic artery that arises from the left gastric artery and courses through the ligamentum venosum

10. Artifact
The cut margin of a liver segment is often echogenic because of small amounts of gas that enter the parenchyma and sinusoids
after cautery or sonication
Should D/D with mucinous colorectal cancer metastases
Acoustic shadowing produced by palpation of the posterior liver surface

13. Applications of Intraoperative US of the Liver
Survey for Primary or Metastatic Lesions
Lesion Characterization
Guidance for Tumor Resection and Metastasectomy
Evaluation of Vessel Patency
Liver Transplantation
Tumor Ablation
Biliary Disease
Extrahepatic Disease

14. Survey for Primary or Metastatic Lesions
Resolution:
larger than 2 mm
Sensitivity:
more than 90%
of 25%–35% more lesions than does preoperative imaging

15. Lesion Characterization
Hemangioma
Varied appearance
Palpation
Doppler
Vessel involvement

16. Lesion Characterization
Metastasis
Bull’s-eye or target sign
Colon cancer
Carcinoid tumors
FNH
sarcoma

17. Lesion Characterization
Benign and malignant tumors frequently coexist

18. Guidance for Tumor Resection and Metastasectomy
the presence or absence of vascular occlusion or invasion
margins of 1–2 cm are required for adequate lesion resection

19. Guidance for Tumor Resection and Metastasectomy

20. Evaluation of Vessel Patency
Benign
displacement and effacement of vessels
Malignant
invasion and occlusion of vessels

21. Evaluation of Vessel Patency
a tumor-associated thrombus:
avascular
a tumor thrombus :
an arterial waveform at pulsed Doppler evaluation

22. Clinical Role of Intraoperative US
Schmidt et al showed a sensitivity and specificity
of 98% of 95%, respectively, for detection of colorectal
cancer metastases
intraoperative US still provided additional useful
information in 50% of their patients, and this information
resulted in a change in the surgical procedure in 15%
40% of the lesions demonstrated by intraoperative US
were neither visible nor palpable at surgery