**2.5 Technical considerations for resection**

The majority of benign liver lesions are asymptomatic, leaving surgical resection as an appropriate therapy only in cases of symptomatic disease that is clearly attributable to the lesion, or when the diagnosis remains in doubt following appropriate workup. The exception is for hepatocellular adenoma, where the risk of malignant degeneration mandates resection for lesions larger than 5cm or cases occurring in men.

#### **2.5.1 Patient positioning**

There are three commonly used patient positions employed in laparoscopic liver resection: supine, lateral decubitus, and the so-called French position in which the patient is supine with the legs in stirrups and the surgeon is positioned between the patient's legs. The appropriate position is determined based on the location of the tumor, and the surgical technique to be employed. The French position has the advantage of allowing the surgeon to operate with both hands while assistants can retract from either side of the table. The supine position is best employed when approaching lesions on the left lobe or right anterior sector of the liver. The lateral decubitus position places the patient recumbent on their left side at an angle of sixty degrees. This position allows access to the posterior segments of the right liver, as the left side down positioning prevents the liver from falling dependently into the operative field. When a hand port is to be employed, it is generally placed in the right upper quadrant as dictated by the position of the tumor being resected.

### **2.5.2 Anesthesia and intraoperative care**

The use of low CVP anesthesia has been a critical factor in the improved safety of modern hepatic surgery. This technique mandates the use of central venous catheters and arterial lines for patient monitoring. During the parenchymal transection phase, central venous

Laparoscopic Liver Resection 69

conversion be necessary during a pure laparoscopic procedure, it should initially be to a hand assist method rather than to full laparotomy. In all cases, conversion should not be viewed as a failure or complication, but rather as a measure of prudent judgment (Buell, JF

After becoming comfortable with resection of benign lesions, the logical progression in the development of a laparoscopic liver program is the resection of malignant lesions. These lesions require an increased degree of skill on the part of the surgeons in order to attain adequate margins and maintain oncologic adequacy. The presence of cirrhosis in the setting of HCC or steatohepatitis following neoadjuvant chemotherapy for colorectal metastasis make proper patient selection and timing of operation critical. The consideration of adjunctive techniques such as transarterial chemoemboliztion for preoperative downstaging also becomes important. Here, we will discuss laparoscopic management of the two most common malignant hepatic tumors: colorectal metastases and hepatocellular carcinoma.

Colorectal metastases are the most common malignant hepatic tumor. Results following open resection of these lesions have been excellent, with 5 year survival rates exceeding 50% in many centers (House, MG et al 2010). Such outcomes have set a high standard by which laparoscopic resection must be measured. The adoption of laparoscopy to this field has been hindered by concerns of tumor seeding at port sates and the possibility of missing extrahepatic lesions by inadequate inspection of the peritoneal cavity(Hsu, TC 2008; Johnstone, PA et al 1996). These hurdles have slowly been brought down, and laparoscopic

Patient selection criteria for laparoscopic resection of colorectal metastases are similar to those applied for open resection. Initial evaluation requires precise definition of tumor anatomy and exclusion of extrahepatic disease. We favor triple phase CT as the initial radiographic evaluation. When combined with digital arterial reconstruction, evaluation of aberrant vascular anatomy, which can be present in nearly half of all patients, is afforded. Evaluation of baseline liver function is performed with evaluation of bilirubin, INR, and albumin. A thorough history and physical exam is necessary to assess general fitness for major abdominal surgery. Tumor resectability is defined by the SSAT as an expected negative margin resection with preservation of at least 2 contiguous hepatic segments with adequate inflow, outflow, and biliary drainage and a future liver remnant of more than 20%

The use of chemotherapy and chemoradiation for metastatic colon and rectal cancer has become a mainstay of therapy. Modern chemotherapeutic regimens generally consist of 5 fluorouracil combined with either oxaliplatin (FOLFOX) or irinotecan (FOLFIRI) have produced excellent response rates, and have been able to render 10-30% of previously unresectable disease amenable to surgical therapy. Agents such as cetuximab and bevacizumab have shown even better response rates. This efficacy is not without a price,

resection is now a standard part of the therapeutic arsenal for hepatic malignancy.

et al 2009a).

**3.1 Colorectal metastases** 

**3.1.2 Patient selection** 

**3.1.3 Neoadjuvant therapy** 

**3. Laparoscopic liver surgery for malignancy** 

for normal parenchyma(Charnsangavej, C et al 2006).

pressure is lowered to between 2 and 4 mmHg with the use of nitrates, nitrous oxide, and dieresis. Combined with the tamponade effect of pneumoperitoneum, this technique minimizes blood loss from venous parenchymal bleeding (Tranchart, H et al 2010). Concern has been raised over the possibility of carbon dioxide embolism during laparoscopic liver surgery; however, extensive use of CO2 as an intravenous contrast agent in interventional radiology procedures shows that these fears are probably overstated (Hawkins, IF & Caridi, JG 1998). Argon embolism, on the other hand, is a legitimate fear, and we advocate against the use of the argon beam coagulator on hepatic parenchymal veins. Furthermore, it is prudent to lower insufflations pressures during use of the argon beam.

Minimization of blood product usage is another key component of intraoperative care. The use of intraoperative thromboelastography (TEG) allows for near real time assessment of the coagulation cascade with replacement of coagulation factors as appropriate. The cell saver is well accepted as a means of minimizing blood transfusion requirements during operation for benign indications. Cell saver use in the setting of malignancy is more controversial; however, the employment of adjunctive measures such as leukocyte depletion filters may minimize the burden of tumor cells in salvaged blood (Liang, TB et al 2008).

#### **2.5.3 Parenchymal transection techniques**

A number of parenchymal transection techniques have been described in the literature, with none of them showing clear superiority over the others. Which technique is ultimately chosen thus becomes dependent upon the individual surgeon's comfort level with a given technique. Here we describe two of the more common strategies: electrosurgical dissection and stapler hepatectomy.

Electrosurgical transection techniques rely upon the surgeon's ability to operate two devices simultaneously. The surgeon should use a device such as the Harmonic Scalpel or Enseal (Ethicon Endosurgery, Cincinnatti, OH) in the dominant hand. This device is used to incise Glisson's capsule and for the majority of parenchymal transection. The device should not be fully introduced into the parenchyma to prevent tearing of large vessels. When active bleeding is encountered, it is immediately controlled with bipolar cautery forceps which are held in the surgeon's other hand. Larger vessels require the use of laparoscopic clips. The simultaneous use both devices is facilitated by sitting on a tall stool, which allows the surgeon to operate the foot pedals independently.

Our group has favored the use of stapler hepatectomy. This technique provides the advantage of more rapid parenchymal transection, without the need for prior control of individual hepatic vessels. The first centimeter of parenchyma is relatively devoid of major vessels, and is incised with electrosurgical devices as described above. The dissection then proceeds using the thin blade of the stapler as a dissector. Care must be taken to avoid inadvertent manipulation of the stapler during firing, which can lead to tearing of major vessels and subsequent hemorrhage. The use of hand assistance is helpful in stabilizing the stapler to prevent such complications. We have preferred the use of a 25 mm vascular staple load for parenchymal transection.

When intraoperative hemorrhage is encountered, the presence of a hand in the abdomen is highly beneficial in allowing digital control of bleeding vessels prior to attaining definitive hemostasis. The "quick stitch" as described by Koffron has proven highly useful in laparoscopic control of bleeding vessels. The quick stitch is a precut 10cm suture with two vascular clips placed on the tail of the suture. After the suture is placed and hemostasis is obtained, the closure is secured by additional clips place on the proximal end. Should

pressure is lowered to between 2 and 4 mmHg with the use of nitrates, nitrous oxide, and dieresis. Combined with the tamponade effect of pneumoperitoneum, this technique minimizes blood loss from venous parenchymal bleeding (Tranchart, H et al 2010). Concern has been raised over the possibility of carbon dioxide embolism during laparoscopic liver surgery; however, extensive use of CO2 as an intravenous contrast agent in interventional radiology procedures shows that these fears are probably overstated (Hawkins, IF & Caridi, JG 1998). Argon embolism, on the other hand, is a legitimate fear, and we advocate against the use of the argon beam coagulator on hepatic parenchymal veins. Furthermore, it is

Minimization of blood product usage is another key component of intraoperative care. The use of intraoperative thromboelastography (TEG) allows for near real time assessment of the coagulation cascade with replacement of coagulation factors as appropriate. The cell saver is well accepted as a means of minimizing blood transfusion requirements during operation for benign indications. Cell saver use in the setting of malignancy is more controversial; however, the employment of adjunctive measures such as leukocyte depletion filters may

A number of parenchymal transection techniques have been described in the literature, with none of them showing clear superiority over the others. Which technique is ultimately chosen thus becomes dependent upon the individual surgeon's comfort level with a given technique. Here we describe two of the more common strategies: electrosurgical dissection

Electrosurgical transection techniques rely upon the surgeon's ability to operate two devices simultaneously. The surgeon should use a device such as the Harmonic Scalpel or Enseal (Ethicon Endosurgery, Cincinnatti, OH) in the dominant hand. This device is used to incise Glisson's capsule and for the majority of parenchymal transection. The device should not be fully introduced into the parenchyma to prevent tearing of large vessels. When active bleeding is encountered, it is immediately controlled with bipolar cautery forceps which are held in the surgeon's other hand. Larger vessels require the use of laparoscopic clips. The simultaneous use both devices is facilitated by sitting on a tall stool, which allows the

Our group has favored the use of stapler hepatectomy. This technique provides the advantage of more rapid parenchymal transection, without the need for prior control of individual hepatic vessels. The first centimeter of parenchyma is relatively devoid of major vessels, and is incised with electrosurgical devices as described above. The dissection then proceeds using the thin blade of the stapler as a dissector. Care must be taken to avoid inadvertent manipulation of the stapler during firing, which can lead to tearing of major vessels and subsequent hemorrhage. The use of hand assistance is helpful in stabilizing the stapler to prevent such complications. We have preferred the use of a 25 mm vascular staple

When intraoperative hemorrhage is encountered, the presence of a hand in the abdomen is highly beneficial in allowing digital control of bleeding vessels prior to attaining definitive hemostasis. The "quick stitch" as described by Koffron has proven highly useful in laparoscopic control of bleeding vessels. The quick stitch is a precut 10cm suture with two vascular clips placed on the tail of the suture. After the suture is placed and hemostasis is obtained, the closure is secured by additional clips place on the proximal end. Should

prudent to lower insufflations pressures during use of the argon beam.

minimize the burden of tumor cells in salvaged blood (Liang, TB et al 2008).

**2.5.3 Parenchymal transection techniques** 

surgeon to operate the foot pedals independently.

load for parenchymal transection.

and stapler hepatectomy.

conversion be necessary during a pure laparoscopic procedure, it should initially be to a hand assist method rather than to full laparotomy. In all cases, conversion should not be viewed as a failure or complication, but rather as a measure of prudent judgment (Buell, JF et al 2009a).
