**7. Laparoscopic versus open liver resection - The evidence**

#### **7.1 The learning curve/patient benefit**

Most studies reporting laparoscopic liver resection report a learning curve. How long that learning curve is depends on the type of resection. Small resections less than 2cm require little additional skill to that needed for a complex laparoscopic cholecystectomy when positioned in the anterior segments V, IVb or left lateral segment on the proviso the surgeon has completed a recognised training program in HPB surgery. For more major resections e.g. right heptectomy, left hepatectomy the bar is significantly raised and should only be attempted by surgeons who regularly perform complex laparoscopic procedures. The main limiting factor is technical difficulty and access. Some would suggest that increasing size of tumour is not a limiting factor 60 but this is not what has been recommended in the Louisville guidelines 11.

It cannot be denied that not everyone is suitable for a laparoscopic liver resection. Most centres suggest that up to 30% 68 29 are suitable although those centres performing more major resections regularly report higher rates up to 80% but also report higher rates with hand assisted techniques 82 4. One study suggests a learning curve of 60 cases is adequate to demonstrate quicker operating times and a lower conversion rate 83. Indeed during our 4 year experience the conversion rate has decreased from 14% to 3%. The commonest reason for conversion is usually technical or due to bleeding.

Most studies doing detailed analysis report reduced operating time when different era's are evaluated68. For example, laparoscopic left lateral resection can become significantly quicker84 58 as in our experience, yet for major resection (e.g. right hepatectomy) there is still some progress to be made to reduce operating times compared to open (5 hours versus 3 hours) 61,68 even procedures up to 10 hours have been reported 60. Also anatomical resections are generally quicker than non anatomical wedge resections 68. Nonetheless the learning curve is difficult to assess as it depends on the definition of success which to most would be disease free survival which is rarely discussed. One study has addressed this in detail in a

causing less collateral tissue damage to within 1.5mm of the grasping jaws 77. Tissuelink (Aquamantys TM) works using transcollation (transforming collagen) technology sealing small biliary radicals, no charringand gives a bloodless operating field. This device delivers radiofrequency energy and saline simultaneously to achieve temperatures of 100oC 78. The major disadvantage is that is can be slower and is more expensive. A cheap and effective time honoured method is bipolar diathermy giving good haemostasis on the liver parenchyma using a power of up to 80 watts. There have been concerns regarding Argon Beam Coagulation (ABC) and gas embolism79 because of the stream of argon gas when the instrument is activated particularly on the liver bed when there are large open vessels. It is

There are no well designed controlled studies comparing different haemostatic techniques during LLR but these have been reviewed in detail elsewhere 80 81. Attention to detail regarding securing the bile ducts, identifying and ligating the medium and larger vascular structures are important in ensuring minimal blood loss, bile leaks and achieving an oncologically sound surgical procedure. To realize this, various techniques might be needed at different stages of the operation and therefore a working knowledge of all available

Most studies reporting laparoscopic liver resection report a learning curve. How long that learning curve is depends on the type of resection. Small resections less than 2cm require little additional skill to that needed for a complex laparoscopic cholecystectomy when positioned in the anterior segments V, IVb or left lateral segment on the proviso the surgeon has completed a recognised training program in HPB surgery. For more major resections e.g. right heptectomy, left hepatectomy the bar is significantly raised and should only be attempted by surgeons who regularly perform complex laparoscopic procedures. The main limiting factor is technical difficulty and access. Some would suggest that increasing size of tumour is not a limiting factor 60 but this is not what has been recommended in the

It cannot be denied that not everyone is suitable for a laparoscopic liver resection. Most centres suggest that up to 30% 68 29 are suitable although those centres performing more major resections regularly report higher rates up to 80% but also report higher rates with hand assisted techniques 82 4. One study suggests a learning curve of 60 cases is adequate to demonstrate quicker operating times and a lower conversion rate 83. Indeed during our 4 year experience the conversion rate has decreased from 14% to 3%. The commonest reason

Most studies doing detailed analysis report reduced operating time when different era's are evaluated68. For example, laparoscopic left lateral resection can become significantly quicker84 58 as in our experience, yet for major resection (e.g. right hepatectomy) there is still some progress to be made to reduce operating times compared to open (5 hours versus 3 hours) 61,68 even procedures up to 10 hours have been reported 60. Also anatomical resections are generally quicker than non anatomical wedge resections 68. Nonetheless the learning curve is difficult to assess as it depends on the definition of success which to most would be disease free survival which is rarely discussed. One study has addressed this in detail in a

strongly advisable not to use ABC in this situation.

**7.1 The learning curve/patient benefit** 

for conversion is usually technical or due to bleeding.

**7. Laparoscopic versus open liver resection - The evidence** 

techniques is useful.

Louisville guidelines 11.

non randomized study comparing 120 patients. There does not appear to be any difference in overall 5 year survival in those having either LLR or open resection in terms of disease free survival 85. Most studies report no difference in rates of R0 resection and no increased risk of positive margins after LLR as reviewed elsewhere 10. Although a recent meta-analysis suggests the risk of an R0 resection (<1cm) is twice as high after LLR than for open resection86. Indeed R1 resection rates of up to 43% have been reported 18 and non segmental resections may have the highest risk 87.

For left lateral resections and segmental resections blood loss and transfusion requirements have improved significantly through eras and now most involved in the field would suggest that with more minor resections blood loss is less when compared to open surgery 22,86,4. However this is perhaps not the case for major resection and bleeding can be catastrophic and problematic when it is from a major tributary such as the RHV or venous confluence 19 and this is why some prefer the safety of a hand port when they approach the RHV during right hepatectomy.

The main advantage of LLR are the reported benefits which apply to all minimally invasive procedures. These include reduced post-operative pain relief, reduced hospital stay, less morbidity and mortality. Certainly a recent meta-analysis suggests patients have less blood loss, shorter post-operative stay and a quicker return to activities of daily living for left lateral resection or metastectomy7 6,86,4,10. Without randomized studies this will be difficult to confirm as laparoscopic enthusiasts may have a tendency to send patients home earlier than usual practise and may vary between centres. Generally the disadvantage of higher costs is offset by the shorter stay 88,7,89,90.
