**5.3 Two-stage hepatectomy**

156 Liver Tumors

possible, considering the future liver remnant. In general, all the original sites of disease

Since post-operative morbidity affects long-term survival (Laurent et al. 2003), length of chemotherapy treatment must be taken into account. In recent years more and more patients with stable long-term disease (more than 20 months) are considered for surgical treatment. Irinotecan and oxaliplatin have been associated with the development of steatohepatitis. Among patients receiving these drugs, the rates of complications and death after major liver resection are likely to be higher compared to patients not receiving chemotherapy, although this is not completely clear. Albeit systemic treatment is very effective in reducing tumour burden and facilitates the surgical therapy in previously unresectable patients, the recurrence rate is high because of the presence of residual

Based on objective date, consensus has been reached on what is an adequate liver remnant and what are the "safe" resection percentages depending on the quality and health of the

Normal Liver >20%

Liver injury >30%

If < then PVE should consider

Cirrhosis >40%

Fig. 2. Minimum FLR volume needed for safe liver resection in patients with normal,

When the future liver remnant (FLR) is insufficient PVE should be considered. PVE also constitutes a dynamic pre-operative test on the capacity of the liver to respond to the surgical aggression. If a hypertrophy greater than 5% is achieved after PVE, there is a low risk of a terrible post-operative liver insufficiency (Ribero et al. 2007). Chemotherapy does not seem to affect the hypertrophy induced by PVE. A few studies using bevazucimab recommend a 6 week waiting period between the last dose and the hepatectomy, although

intermediate disease or cirrhotic liver (Zorzi et al. 2007).

its influence on the hypertrophy is unclear.

noted on the pre-therapy imaging need to be resected or ablated.

microscopic disease.

**5.2 Portal vein embolization** 

liver (Zorzi et al. 2007). Figure 2.

Future Liver Remnant

Two-stage hepatectomy is one of the methods to increase the resectability of liver tumours. Its objective is to eliminate the entire tumour burden. The first stage can also be performed together with laparoscopic colorectal resection. It consists of combining two sequential and planned liver resections when it is impossible to resect all liver metastases in a single procedure, while preserving at least 30% of functional liver volume to avoid post-operative liver failure. Frequently, it is associated with peri-operative systemic chemotherapy and PVE, although it is not a rule (Jaeck et al. 2004) (Figure 3).

The first hepatectomy attempts to resect the majority of liver tumours and to get hypertrophy of the remnant liver with or without PVE. The second hepatectomy is performed at least 4 weeks later to allow time for growth and hypertrophy of the FLR. The design of the technique must be meticulous well in advance of the first resection as an important strategy to achieve complete removal, admitting that around 30% of patients will not be rescued on the second hepatectomy.

Usually, on the first hepatectomy the future remnant liver is cleared out of tumours with non-anatomic resections and/or radiofrequency ablation or at most a single segment resection. As mentioned, it can be associated to the removal of the primary colorectal tumour, preferably through a laparoscopic approach or using a "J" incision if it is located on the right colon. After 2 to 4 weeks after the clearance of the FRL, percutaneous PVE is performed. Alternatively, PVE can be done during the first hepatectomy through the ligation and alcoholization of the right portal vein, which is the side more often embolized. The second hepatectomy can be done on the fourth of fifth week after PVE, when an adequate hypertrophy of the non-embolized hemi-liver is achieved.

Some authors recommend pre-operative chemotherapy during the entire process. This should be determined by the criteria of the multidisciplinary team according to each individual case (Adam et al. 2000). We carry out this procedure by performing PVE in the first hepatectomy with or without the removal of the primary tumour. After a 4 week waiting period and a CT confirming an adequate FRL, a second hepatectomy is performed. If during the second stage hepatectomy new liver metastases or extrahepatic lesions are discovered, such as localized peritoneum implants, the procedure can still be performed if a R0 resection can be achieved. A recent series reports a 5 year overall survival rate of 32% for patients on whom the procedure had been completed (Narita et al. 2011).

Two factors affect the success of two-stage hepatectomy: patient selection and optimal chemotherapy regimen. This procedure may be the only therapy able to provide long-term survival and a possible cure for patients with initially unresectable multiple and bilobar CRC liver metastases.

Fig. 3. Multiple and bilobar metastases, right hydronephrosis and rectum cancer involving the right ovarium in a 37 year old woman. After chemotherapy treatment, first stage surgery consisted of tumour clearance of the left liver, anterior colorectal resection, right oophorectomy and right PVE (lower pictures). Five weeks later an extended right hepatectomy was performed.
