Page 10 - index
P. 10

What do you do when you need

a lot of liver? (part 2)
Brian P. Grossbard, DVM, DACVS
Staff Surgeon

L iver abnormalities that require surgical and ligation of the individual lobe vasculature
treatments are a commonly encountered phe- with sutures or vascular staples is the best
nomenon in small animal clinical practice. In technique. Fortunately, the majority of hepatic
the previous article in this series, I discussed lesions do not directly involve the hilus and
several techniques that are available to prac- can be removed with a margin of normal tissue
titioners who require small samples of liver via partial lobectomy.
tissue for diagnostic purposes. As discussed The goal in performing a liver lobectomy
previously, the diagnostic work-up for these is to remove all of the diseased tissue with
liver condition include blood tests and various as large an area of normal tissue as is rea- In an effort to minimize the time required
forms of abdominal imaging. Is this segment, sonably possible. The location of the hepatic for dissection and the hemorrhage associated
we will discuss some of the various surgical blood vessels and the tendency for bleeding with the skeletonization procedures, many
techniques that can be used to remove a large during the procedure can make surgical re- surgeons prefer to use thoracoabdominal (TA)
segment of liver tissue, a complete liver lobe or section challenging. There are several tech- stapling equipment to perform partial liver
a complete division of liver tissue. niques available for partial liver lobectomy lobectomies. The TA stapling devices come is
during open laparotomy in different lengths (30, 55, 90 mm) and contain
dogs. In addition, there are different sized staples. The 2.5 mm vascular
several new laparoscopic staples are the most appropriate for use with
techniques that allow for small hepatic vessels as they compress down
the procedure to be done to 1 mm in height and the extra row provided
via a minimally invasive allows for additional hemostatic security. Stud-
approach. While some of ies show that using larger (3.5 mm) staples
the techniques require the can also be effective, however vessels smaller
use of advanced vessel than the 1.5 mm closing size may continue to
sealing devices, several bleed even after appropriate placement. The
can be performed using advantages of this technique include relatively
equipment found in most rapid and easy deployment and the ability to
small animal hospitals. ligate multiple vessels simultaneously. Cor-
One of the simplest rect application of the stapling cartridge re-
techniques for liver lobe quires minimal tissue interposition so some
resection is known as the degree of skeletonization or compression may
finger fracture or blunt
dissection technique. This Continued on Page 11 ➤
Figure 1 A large hepatic mass arising from the right medial liver lobe. technique results in the
skeletonization of the ma-
The liver can be divided anatomically ac- jor hepatic vessels and exposure for ligation
cording to the branching of the blood ves- with sutures, hemostatic clamps, or surgical
sels supplying the various lobes. In dogs, the staples. This technique is associat-
portal vein in supplies 80% of the blood fow ed with a signifcant de-
to the liver. The frst main branch (right divi- gree of hemorrhage so a
sion) delivers blood to the caudate process and common modifcation is to
right lateral lobes. The left division gives off use a blunt (Poole) suction
a branch to the central division to supply the tip to break down the liver
right medial and papillary process and then parenchyma surrounding
continues to supply the left lateral, left medial the vessels while maintain-
and quadrate lobes (left division). The hepatic ing adequate visualization.
artery follows a similar pattern of distribution, Advantages of this technique
however, individual variation is common. allow an experienced surgeon
When evaluating a hepatic lesion for po- to remove a section of normal-
tential removal, the mobility of the lesion and feeling liver tissue while ensur-
potential involvement with other liver lobes ing that the ligatures are holding
play a role in decision making. Removal can via direct visualization. Unfortu-
be performed via partial (most common) liver nately, recent papers have shown
lobectomy or complete (hilar) lobectomy. Le- that this technique is also associat-
Figure 2 The right medial
sions that extend to the hilus of the liver can ed with the most signifcant amount liver lobe and associated mass
be challenging to remove. Generally, isolation of blood loss during surgery. following liver lobectomy.

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