9%20ECOGRAFIA%20ABDOMINAL%20COMO%20CUANDO%20DONDE

INTERVENTIONAL AND OTHER TECHNIQUES 265
A
B
C
Figure 11.12 Intraoperative ultrasound (A) Demonstrating a margin of tissue of only 2 or 3 mm between the
metastasis and the hepatic vein. (B) Metastasis in segment 8, at the confluence of the hepatic veins. (C) This metastasis
has started to invade the hepatic vein. (D) Tiny metastasis, not diagnosed on preoperative imaging and not surgically
palpable. (Differential diagnosis would be of haemangioma.)
D
LAPAROSCOPIC ULTRASOUND
Dedicated laparoscopic ultrasound probes may be
passed through the laparoscopic port during surgical
procedures to investigate the liver, biliary tree,
pancreas and other viscera without the need for open
surgery (Fig. 11.14).
The trend towards laparoscopic rather than
open cholecystectomy has increased the need for
accurate laparoscopic exploration of the biliary
ductal system to confirm the presence or absence
of stones. Laparoscopic ultrasound is better at
demonstrating stones in the duct and anatomical
ductal variations than conventional intraoperative
cholangiography. 21
Laparoscopic ultrasound has also proven
advantageous in staging patients with hepatic
tumours for liver resection, 22 demonstrating deep
tumours not visible on surgical laparoscopy, or by
preoperative imaging methods and so avoiding the
need to proceed to open hepatic resection in some
patients.
Patients with pancreatic head and ampullary carcinomas
are potentially resectable in only a minority
of cases. Preoperative imaging is known to underestimate
the extent of the disease, and so many
patients traditionally undergo a staging laparotomy
before resection is attempted. However, over onethird
of patients previously considered resectable