Introduction

Since Louiseville Statement in 2008, laparoscopic liver resection (LLR) has significantly evolved. That consensus statement used the terms pure laparoscopy, hand-assisted laparoscopy, and the hybrid technique to define laparoscopic liver procedures. The recommendation was that the most favorable indication for laparoscopic resection was a solitary lesion, 5 cm or less, located in liver segments 2 to 6 and that left lateral sectionectomy should be considered a standard practice¹.

The second Consensus Conference on LLR held in Morioka, Japan, determined that the focus was patient safety, and the superiority of LLR over the conventional approach began to become evident. Consequently, the laparoscopic approach was recommended for minor liver resections and major LLRs should be performed only in centers with high experience in this field. The consensus conference recommended the creation of a registry of LLR, a difficulty scoring system and a formal structure of education for young surgeons².

Thereafter, the Southampton Guidelines were published, advocating that the laparoscopic approach should be considered standard practice for lesions in the left lateral and anterior segments based on the best scientific evidence available and on the experience of experts worldwide. Laparoscopy was also considered feasible in resections for large lesions, lesions in the postero-superior segment lesions, redo liver resections and 2-stage hepatectomies. These guidelines do not support LLR without adequate training. The centers that are interested in developing LLR should implement a program of minimally invasive surgery, with progressive training and only offer LLR to patients with adequate indications, according to the acquisition of appropriate skills, and should have a minimum of 2 surgeons competent in LLR³.

Laparoscopic liver resections are technically demanding procedures, the working space is very reduced, and some resections require curved parenchymal transection lines which are more complex to perform. Lesions close to the diaphragm are difficult to approach and resection margins are complex to assess. One of the major difficulties is the management of blood loss that may occur during parenchymal transection, from the suprahepatic veins or inferior vena cava. The need for specific equipment and instruments is another limitation when performing LLR, besides the loss of three-dimensional visualization and touch.

Several publications have demonstrated that LLR is at least as effective as open surgery in terms of morbidity, mortality and survival. In addition, operative times, blood loss and length of hospital stay are shorter than those of patients who undergo open surgery^4-10. Nevertheless, most liver resections are still performed by the open approach. A recent publication reported that only 5.4% of hepatectomies in the United States were performed by laparoscopy, varying between 4.6% and 20% in different centers, while the applicability of LLR was 28% in a multicenter South American experience^11,12.

The aim of this study is to present the initial experience and applicability of LLR in two centers in Argentina.

Material and methods

We conducted a retrospective analysis of a prospective database of patients undergoing liver resection at Hospital Universitario Fundación Favaloro, Buenos Aires, and Sanatorio Ipensa, Hospital Universitario Integrado a la Facultad de Ciencias Médicas de la Universidad Nacional de La Plata, between August 2010 and December 2019. Both institutions used the same preoperative evaluation, anesthesia and surgical technique, postoperative care and follow-up. The decision to perform the procedure by laparoscopy was made by the surgeon in charge of the patient and defined in a case conference at the Department of Surgery. At the initial stage, lesions larger than 8 cm, close to large vessels, involving more than 2 sites of resection or those requiring hepaticojejunostomy, were considered contraindications. Nowadays, based on the Japanese experience, we only consider the need for vascular or bile duct reconstruction as a contraindication¹³.

The following variables were analyzed: preoperative data (demographic data, indication for surgery, size, location and number of lesions, type of liver resection, type of LLR performed, presence of cirrhosis), intraoperative data (operative time, hepatic pedicle clamping, associated surgical procedures, need for transfusion, conversion to conventional surgery) and postoperative data (complications, length of hospital stay, 90-day mortality, R0 resection rate). Patients with cystic liver lesions who underwent pericystectomy or fenestration of cysts were not included in the present study.

Intraoperative ultrasound was performed using a conventional ultrasound probe introduced through the laparotomy used for the insertion of the surgeon’s hand (hand-assisted procedures) or a 10-mm flexible laparoscopic probe.

Laparoscopic liver resections were classified following the Louisville Statement¹. Major liver resection was considered when > 3 segments were resected. The complexity of liver resection was evaluated with the Iwate criteria².

Hepatic pedicle clamping was performed using intermittent Pringle maneuver with clamping periods of 15 minutes separated by 5-minute periods of reperfusion. The maneuver was extracorporeal in all the cases. R0 resections were defined with a margin > 1 mm.

Complications were categorized using the Clavien-Dindo classification and those > grade 3 were considered major complications¹⁴.

For the evaluation of applicability, the sample was arbitrarily divided into 3 stages:

▪▪Stage 1; from August 2010 to December 2013

▪▪Stage 2: from January 2014 to December 2016

▪▪Stage 3: from January 2017 to December 2019

Survival of malignancies is not reported as it was not the aim of this study.

Continuous variables are expressed as mean ± standard deviation (SD) or median and range between brackets. Categorical variables are presented as frequencies (n) or percentage. The results were compared using the chi square test, Fisher’s test or Student’s t test. All the statistical calculations were performed using IBM SPSS Statistic 25.0 software package.

Results

A total of 385 liver resections were performed during the study period; of these, 119 were LLRs. Global applicability was 31%. Forty-four percent were pure laparoscopic procedures (53 patients) while 54% were hand-assisted (64 patients) and 2% (2 patients) corresponded to hybrid procedures.

Sixty percent (70 patients) were women and mean age was 54 + 16 years.

Malignant lesions were the cause for LLR in 72 (61%) procedures, 44 (36.5%) had benign conditions and 3 cases (2.5%) were living donors hepatectomies.

In patients with malignancy, 44 (37%) had colorectal liver metastases, 10 (8.4%) had hepatocellular carcinoma, 7 (5.9%) had non‐colorectal non‐neuroendocrine liver metastases, 5 (4.2%) patients presented intrahepatic cholangiocarcinoma, 5 (4.2%) patients presented gallbladder cancer and 1 (0.8%) patient had hemangioendotelioma. Benign conditions included adenomas 10 (8.4%), focal nodular hyperplasia 10 (8.4%), simple hepatic cyst 7 (5.9%), hemangioma 5 (4.2%), hydatid cyst 3 (2.5%), policystic liver disease 3 (2.5%), intrahepatic duct lithiasis 3 (2.5%), hamartoma 1 (0.8%), granuloma 1 (0.8%), infection 1 (0.8%), lymphoma 1 (0.8%), and 3 living donors (2.5%).

Thirty-one (26%) procedures were major LLRs and 88 (74%) were minor LLRs. According to the Iwate criteria, the difficulty level was intermediate or low in 60% of the cases (72 patients) and advanced or expert in 40% (47 patients): 113 procedures were first liver resection (95%) and 6 cases were redo hepatectomies (5%). Nine procedures (7.6%) were performed in cirrhotic livers.

The Pringle maneuver was performed in 21% (25 patients) with a median of 30 minutes (11- 90). Associated surgical procedures were done in 41 (34%) LLRs: cholecystectomy 19 (46.4%), colectomy 5 (12.2%), lymph node clearance 5 (12.2%), incisional hernia repair 4 (9.8%), liver cyst unroofing 3 (7.3%), ALPPS 1 (2.4%), resection of the diaphragm 1 (2.4%), vena cava resection 1, (2.4%), bile duct exploration 1 (2.4%) y reimplantation of the ureter 1 (2.4%).

Median operative time was 240 minutes (450- 530). Eleven (9.2%) liver resections required transfusion of packed red blood cells (mean 1 + 0.6 units).

Conversion to conventional surgery was necessary in 9 patients (7.6%) due to bleeding (3 patients), parenchymal transection (1 patient), more lesions (1 patient), adhesions due to previous liver resection (1 patient) and proximity with the vena cava (1 patient).

Postoperative complications occurred in 29 cases (24%); 9 were major complications (8%).

Mortality at 90 days was 1.7% (2 patients); 1 patient died of pulmonary embolism on postoperative day 3 and the other patient, who had cirrhosis and miastenia gravis, developed complications associated with the neurologic condition during the first month after surgery. Both patients had liver cancer.

Median length of hospital stay was 3 days (1- 14) with a median stay of 1 day (0-7) in the intensive care unit (ICU). Fifteen LLRs did not require admission to ICU (13%).

Ninety-seven percent of LLRs for malignancy (70-72) had negative margins (R0).

Global applicability was 31% (119/385), 23% (33/143) in stage 1, 30% (39/132) in stage 2 and 44% (47/108) in stage 3, p < 0.05.

The number of patients treated for cancer increased significantly across the different stages: p < 0.05, while the presence of cirrhosis was not different (Table 1).

The number of complex liver resections significantly increased from stage 1 to stage 3, p > 0.05. However, when the Iwate criteria were analyzed according to the need for multiple resections across the different stages, there were no statistically significant differences (Table 2).

The conversion rate, Pringle maneuver and operative time in the 3 stages are shown in Table 3. The Pringle maneuver was the only variable with significant increase in stage 3; p < 0.05.

Despite the number of complications decreased in stage 3, there were no significant differences across the different stages and major complications were also similar (Table 4).

Table 5 shows that length of hospital stay and ICU stay were not significantly different.

Discussion

Despite the development of LLRs, most hepatectomies are nowadays approached by conventional surgery. The applicability of LLRs varies considerably, as Pekolj et al. demonstrated in their study carried out in different surgical centers in South America¹². This may be due to different factors, as surgical experience, infrastructure of the centers, financial aspects, etc. Our overall applicability was 31% and was 44% in stage 3. In 2015, Pekolj et al. published their initial experience of 109 LLRs, representing 9% of the liver resections performed in their institution¹⁵. Possibly, the fact that we started our experience by the end of 2010, when the surgical technique was developed and refined, is the reason for the difference in applicability. The International Survey on Technical Aspects of Laparoscopic Liver Resection (INSTALL) was the first large-scale international survey of LLRs. The survey showed that applicability was greater than 40% in only one third of U.S. hospitals, and was much lower in the rest of the world¹⁶.

The recommendation is to start performing LLRs with single and small lesions of the anterior segments^1,3. Cherqui et al. presented their initial experience with LLRs in anterior segments¹⁷. They also suggest that surgeons performing LLR should have previous experience in liver surgery and in laparoscopic surgery. Our experience began after performing liver surgery and complex abdominal laparoscopic surgery for more than 10 years. Both the Morioka and Southampton conferences demonstrated that a gradual progression in the complexity of LLRs is necessary to achieve acceptable and safe results^2,3. In this study, we can appreciate that complexity has varied over time and more complex hepatectomies were performed in stages 2 and 3.

The learning curve (LC) is different, depending not only on the place of practice and on the characteristics of the patients and their tumors, but also on the technical capabilities of the surgeon, the availability of technology and the moment when the surgeon decides to develop the technique. The LC of innovators, i.e., those surgeons who first developed a technique, has proved to be slower compared to that of adopters. Vigano was one of the first authors to report that a learning curve of 60 cases was necessary for laparoscopic hepatectomies to increase the magnitude of the procedures and thus improve the technical results. He concluded that the technique is reproducible in liver units but specific training to advanced laparoscopy is required¹⁸. Tomasssini et al. described three periods of time in the LC: period 1 is the time a surgeon needs to develop his/her initial experience; period 2, when the surgeon - due to acquired confidence and experience - tries to perform more complex procedures; and the last period, when the LC has been completed. The stated that after 50 cases, the surgeon has acquired sufficient experience and expertise to reduce blood loss during parenchymal transection which is undoubtedly the most difficult moment of the procedure. They also considered that, after 160 cases with stepwise difficulty, he/she is qualified to perform major liver resections and hepatectomies of the postero-superior segments¹⁹. The LC can be evaluated by the operative time. We can see how we managed to significantly reduce the operative time during stage 2. The operative time increases in stage 3, but this change is associated with more complex resections and those involving the posterior segments.

The indications for LLR are not a minor issue; the fact that the procedure has few complications and the recovery is faster does not allow over-indication. In the first world review of LLR, Nuyen et al. published that 45% of LLRs were due to benign lesions and 1.7% corresponded to living donor hepatectomies^20,21. In another review by Ciria et al. with more than 9000 LLRs, 65% of the resections were due to malignancies²¹. The indications for resection in patients with benign lesions include symptomatic patients, sustained tumor growth during follow-up or unclear diagnosis. Our indications evolved in the same way as the international literature did: resections for malignancy increased with experience²².

We have showed that most procedures were pure laparoscopic or hand assisted. There is no strong evidence demonstrating which procedure is the best. Ling et al. reported that the pure laparoscopic method is suitable for experienced surgeons to achieve better cosmetic outcomes, whereas the hand-assisted laparoscopic method is associated with better perioperative outcomes and is most useful for resection of cirrhotic livers, lesions in unfavorable locations, and living donor hepatectomies⁸. We can add that, in our environment, the hand-assisted technique is useful when a translaparoscopic ultrasound scanner is not available, using the incision for the hand to perform the ultrasound. Using propensity score matching, Geller et al. compared the three techniques. There were no significant differences in both techniques in use of the Pringle maneuver, transfusion rate, morbidity or R0 resection rate. However, they showed that the hand-assisted and hybrid techniques presented shorter operative time, less blood loss during hepatectomy and shorter length of hospital stay²³. The use of the hybrid technique has been limited in our series. Based on the results published in the international literature, the use of this technique could expand especially to those cases that are currently considered contraindications, such as liver resections requiring hepaticojejunostomy and vascular reconstruction, or due to a lack of supplies, such as energy devices.

Undoubtedly, LLRs highly depend on technology. Adequate laparoscopic equipment, high-flow insufflation pump, energy devices and mechanical stapler are indispensable. These elements increase the costs of the procedure. Nevertheless, the reduction in blood loss, hospital length of stay and operative complication decreases costs^9,24.

Conclusions

The results of this series demonstrate that, despite their complexity, LLRS are procedures that are technically reproducible. Applicability increases with the acquisition of experience, not only for malignant lesions but also for complex lesions. The main recommendation should be to indicate LLR when expertise has been completed to ensure patient safety.

Discussion at the Argentine Academy of Surgery*

Emilio G. Quiñonez: Thank you, Mr. President. Firstly, I would like to congratulate Dr. Enrique Ortiz for the excellent presentation and, of course, Fundación Favaloro and Sanatorio Ipensa for the cases presented.

If Mr. President will allow me, I would like to share with you the experience of Hospital Nacional El Cruce.

Hospital El Cruce is a public referral hospital, a high complexity center that initially started its activities in 2008 and where we started our transplantation program in 2013 and two years later our practice in complex liver and biliary surgery and liver transplantation.

Clearly, nowadays there is no doubt that liver resection can be performed by laparoscopy, it is a technique already considered a standard; but, in line with some studies that the doctor has just mentioned, there are few details and issues to consider, basically related with the elements available for its adequate implementation with an adequate safety margin for the patient, as laparoscopic equipment, energy devices, instruments for parenchymal transection and the use or not or the availability of a translaparoscopic ultrasound scanner.

This is an example of a cirrhotic liver that was resected through laparoscopy guided by the demarcation line. This is all necessary to carry out a safe procedure for the patient.

Between January 2015 and March 2020, we performed 168 liver resections in our unit, of which 44 were pure laparoscopic procedures; this represents an applicability of 23.9% in our series across these five years of work.

Here you can see the distribution by sex and age. The distribution is relatively similar, with less prevalence in women; however, in the age interval below 40 years, the prevalence is slightly higher in women.

Laparoscopic resections for malignant lesions account for 40%; in non-cirrhotic livers, five cases represent 11% and the remaining 48% were benign lesions, of which 25% were solid tumors.

Mean operative time was 202 minutes and you can see here how these segments were resected: 27 segmentectomies of 1 segment, 17 of 2 segments and the rest were atypical resections.

Here you can see the distributions of the segments resected.

Conversions were necessary in 11.36% of cases, the most common causes were bleeding, in one case conversion was due to breakage of mechanical suture, and to instability and saturation in another case.

Over time, when we started our activity in 2015 until today, you can see how it gradually grew but, unfortunately, in 2017 we were practically unable to perform laparoscopic hepatectomies due to the hospital funding issues. We resumed our activity in 2018 and, since March 2020, we decided - because of what has already been discussed in this Academia - to stop the use of laparoscopy and managed liver resections directly by the open approach due to the current pandemic.

With respect to morbidity, 8 cases developed complications, 18%, and a Clavien-Dindo V patient with cirrhosis died due to peritoneal infection, which corresponds to a 30-day mortality of 2.27%.

Mean length of hospital stay in the intensive care unit was 1.8% days; many of these patients -due to lack of beds available- had to be discharged directly from the intensive care unit so as not to lose one of the advantages of the laparoscopic approach, which is shorter length of hospital stay. We divided the consumption of blood products into “converted” and “non-converted” because the use of blood products in almost all the patients who were not converted and underwent purely laparoscopic procedures was very low; however, in those who were converted, as I showed in the previous slide, the use was high due to instability and bleeding, and therefore they received multiple tranfusions.

An important topic I would like Dr Ortiz to answer, is that we also have a fellowship program in hepatobiliary surgery and liver transplantation since the last five years.

When we reviewed our series of 44 laparoscopic hepatectomies, we found that 25% of the series was purely performed by our physicians who were already general surgeons in training in the surgical subspecialty.

I would now like to ask Dr. Ortiz a question and make a brief comment.

In terms of methodology, I would like to ask you why the division into three periods, if this is a purely arbitrary criterion, or you noticed some change in the number and that is why you made such division.

My second question is: I noticed that focal nodular hyperplasia was one of the main causes of resection for benign tumors; it is interesting, because in our experience as liver surgeons, this tumor rarely requires surgery unless it is symptomatic. I fully agree that, since it is a benign tumor, it should be approached by laparoscopy according to the location and experience, but I would like to ask if you have noticed that it is one of the most important indications.

The third point: Fundación Favaloro is historically one of the most important centers in the country in liver transplantation and liver surgery and I have noticed that 22 resections were performed due to hepatocellular carcinoma, almost the same number as El Cruce over a shorter period and with less frequency. So, I ask you if it is because you believe that liver transplantation provides the greatest advantage in hepatocellular carcinoma, which is my idea, but evidently in times like this or before procurement increased, perhaps liver resection and fundamentally laparoscopic resection which has great value, can be used and with very good results. I ask you if this has drawn your attention.

And finally, also knowing that Fundación has a long history in training human resources in this area, I would ask you if you could see how many of your patients resected by laparoscopy were operated on exclusively by doctors in training, of course always under supervision as in our case and, as I imagine, in your case.

Again, I congratulate Dr. Ortiz for his very good presentation and Fundación and Sanatorio Ipensa for the experience shown here. Thank you, Mr. President.

Enrique Ortiz: Thank you very much, Dr. Saco; thank you very much, Dr. Quiñonez.

The first question was about the three stages. Obviously, the division was arbitrarily chosen, but clearly in the last stage we were already noticing greater applicability because of the greater experience and expertise of those who developed the technique, but the division was totally arbitrary to compare the different variables analyzed in three stages.

The second fact regarding focal nodular hyperplasia is true. In two cases the patients had undergone surgery for neuroendocrine tumors, and later a lesion in the liver was diagnosed, and we were not sure if the lesion corresponded to metastasis. So, we approached the lesion with the idea that it could be a neuroendocrine tumor metastasis, and the pathology report showed focal nodular hyperplasia.

In another case, which was a laparoscopic cholecystectomy for benign gallbladder disease, the team noticed a small lesion next to the gallbladder; as the procedure was performed in a liver surgery center, a simultaneous resection was decided. Probably this would not be recommended in a center that is not a dedicated to hepatobiliary and pancreatic surgery, but in this case the liver lesion was resected and turned out to be focal nodular hyperplasia.

There were ten cases of hepatocellular carcinoma treated by this technique; if resection is not feasible, radiofrequency is also used as an alternative and, if none of these possibilities are available, liver transplantation is also possible, depending on availability.

Juan Pekolj: Good evening. Firstly, thank you for giving me the opportunity to participate in the discussion and in the contribution to this excellent work.

I would first like to congratulate Dr. Ortiz for the excellent presentation he made and Dr. Barros Schelotto for leading this very enriching experience.

I will try to contribute with our experience and explain how the situation is worldwide.

The truth is that I would first like to emphasize the fact that performing comparable experiences in different institutions gives reliability and credibility to what has been done and is being done, because I believe that nowadays one of the greatest problems of surgery is that in many cases the experiences cannot be reproduced because of technical reasons, availability of methods or type of patients; since the experiences are very comparable, this series meets the standards or is in tune with those of international publications.

We will see that both the learning curve, which I think is an extremely interesting topic, and operative time, conversion rate, morbidity and mortality also follow the requirements of what I would call a mature series. The same applies to the oncologic results, and a very important slide showed that R0 resections were present in more than 90% of the patients, which indicates that the technique was very well performed.

We agree with the discussion of the Pringle maneuver; it is always better to clamp when the patient is bleeding, totally in tune with our thoughts. Undoubtedly, logistics in implementing the program was interesting, and it will surely be one of the questions.

The truth is that today one asks, and in this case also, if there is a comparison, if there is a division, if there is a crack, that is so in fashion, between open and laparoscopic liver resection, because sometimes I believe that all the series that are presented have a bias, a reasonable selection bias.

So, I think it would be controversial to propose that the image on your left should be approached by open surgery and the one on the right by laparoscopy. In fact, one might say: why do you choose open or laparoscopic hepatectomy?

I believe that the experience of the center counts first, and the authors of the paper clearly demonstrate the need for combining experience in open liver surgery and advanced laparoscopy. Therefore, these are problems or conditions that should be managed in HPB surgery centers and not in those that nowadays are called laparoscopic surgery centers that do a little bit of everything by laparoscopy, which I believe is not the ideal.

As I have just shown, the type of lesion is a conditioning factor for the selection, the technology available; the volume of cases: five cases per year does not even allow us to attempt the procedure by laparoscopy; the type of patient: a cirrhotic patient is not the same as a patient without cirrhosis, and the level of training of surgeons, which has been emphasized during the presentation of the Southampton publication.

Obviously, if we go back to our first publication, speaking of 24 laparoscopic liver resections nowadays would be very embarrassing, but the truth is that this was the fact in 2008, when we had to overcome many barriers from the perspective of logistics and credibility, because at that time it was impossible to believe that laparoscopy could reproduce what was done in open surgery. Then, a few years later, as the authors mentioned, and I am grateful for mentioning the papers, we reached 100 laparoscopic liver resections. Then we made progress, and we are going to show you how applicability varies according to the period observed which has a lot to do with the type of patients we receive.

If we look back over the last few years, we perform an average of about 100 hepatectomies per year with some fluctuations in some years, and if you consider how the indication for the laparoscopic approach has been growing, from 15% in 2013 to 39% in 2019, we have to continue working in these current circumstances; this last case we operated on is an 83 year-old patient who underwent laparoscopic liver resection with all the advantages of a minimally invasive approach in the COVID era.

I would like to take this opportunity to thank all the authors who contributed with their experience, and among them the authors of the paper presented today, as this survey clearly showed that in South America there are at least 51 centers performing laparoscopic surgery with a global applicability of 28%, but we can see a very important variability between 4% and 84% that has to do with the data reported by the authors as to the reasons for the changes.

And I think that if we want to compare where we are with where other places are, it is sometimes important to consider the population of a nation. For example, Brazil has 1,326 liver resections; yet, when we correlate them with the population, they perform 6 resections per million inhabitants. Argentina has fewer resections and less population, and the rate is higher, so I could perhaps say that in Argentina the general population benefits more from the laparoscopic approach and perhaps this would not be the way to communicate COVID-related mortality, which is so in fashion today, and we do not know how to do so. And if we compare it with the world, Japan is undoubtedly the most developed place, with 157 liver resections by laparoscopy per million inhabitants.

However, it is very important to mention that Japan has the best references because all the surgeries must be recorded in a registry, and surgeries that are not recorded are not paid. In Japan, which is the most developed country in terms of the number of liver resections, 25% of all liver resections are performed through laparoscopy, so the numbers presented by the authors of this work are really commendable.

And if we consider the presentation made at Academia, precisely of the same Argentine reality, we see that in Argentina of 26 centers that perform laparoscopic liver resections, only 6 are in the Autonomous City of Buenos Aires, and I believe that what is very interesting is that the leaders of these reference centers, and Dr. Barros Schelotto is not an exception in this case, are between 45 and 50 years old, that is to say, the generation of surgeons in charge of the management of the disease has changed.

We see that in Argentina most of the centers have less than 50 resections; however, the experience that has just been presented already exceeds 100 cases, and in Argentina the global application is 21%, and 50% of the Argentine population has less than 30% of applicability in the different centers, so there is a full correlation between what the authors show and the international and national reality, and the first indication is the presence of metastasis and colorectal cancer.

Another important thing that the authors also emphasize is that major liver resections increased across the different three stages, but minor liver resections were always more common because nowadays the idea is to perform parenchymal sparing surgery and atypical resections are the most common among them.

Which are the limitations in our country?

I believe that in some way the organization of the fee-for-service public versus private health care system was outlined.

The presentation clearly demonstrated that resources, need for technology, lack of centralization, although is slowly developing, and the need for training, as I will now mention, are some limitations.

However, I believe that it is also very promising and that this experience that is being published and presented today at Academia Argentina de Cirugía is a testimony of that, because there are new mentors, there are well-trained surgeons in laparoscopy previously trained in liver surgery, new units of HPB diseases are being developed, there is scientific evidence. This is no longer experimental, as we were told in 2005, and there is international experience that gives us great support, and finally we will surely be able to participate in the American registry of liver resection.

So, these are all my questions for the authors of the paper and the first one is: what are your current criteria for indicating hand-assisted hepatectomy? As this was the most common approach that you performed of the three methods,

I appreciate that you have sent me the paper where you somehow raised the need to perform hepaticojejunostomy associated with liver resection; today this is a contraindication for the laparoscopic approach, and I do not know if I would suggest that perhaps nowadays liver surgeons must still be biliary surgeons and perhaps this contraindication is just a matter of time.

The third question is a major topic of discussion: what technique do they prefer for parenchymal transection?

And finally, I was surprised that only 13% of your patients did not require admission to the ICU; it is true that they stayed almost one day in the ICU, but one of the great advantages of laparoscopic surgery is that the need for intensive care has considerably decreased.

So, again, I am grateful for the possibility of being part of this discussion, for having submitted the work to me, and I congratulate you for the work done. Thank you.

Enrique Ortiz: Thank you very much, doctor Pekolj. Your comments were excellent.

As for the first question, we indicate hand-assisted laparoscopy mainly in large lesions and in posterolateral segments.

About the second question, hepaticojejunostomy is performed following the Japanese guidelines, which show a higher morbidity (up to five times) and mortality for this procedure.

With respect to the third question about parenchymal transection technique, if possible, and this also obviously depends on availability and financial entities, the preferred techniques for parenchymal transection are CUSA in first place and secondly, the harmonic scalpel.

Finally, in fact in many cases length of stay in the intensive care unit depends on the management of beds in the general ward, and sometimes the ICU bed was required before surgery; usually the patient goes to the intensive care unit because he/she requires so and sometimes because there are no beds available in the ward.

Thank you very much again.

If I may, Dr. Saco, actually Dr. Quiñonez, Dr. Pekolj also pointed out something about the learning curve. I believe that both Fundación Favaloro, which has fellows in hepatobiliary and pancreatic surgery, and Sanatorio Ipensa are gradually transferring skills in laparoscopy to the young surgeons in this specialty, because on the one hand, in complex cases some steps of the surgery are shared, for example, there are times when the trainee is on one side of the patient and has better access than us to parenchymal transection, use of argon plasma coagulation and firing of stapler, all the important elements for transection. And of course, resection of peripheral and smaller lesions are the first procedures performed by trainees, so thank you very much.

I believe this has completed the answers.

Manuel R. Montesinos: There are several questions, some of which have already been partially answered, and a lot of compliments for the work.

Carlos González: Did you use APC (argon plasma coagulation)?

Enrique Ortiz: Yes, exactly, it is one of the elements we use. It is usually incorporated in the operating room, as the operating room requires cutting and coagulation devices, either harmonic scapel or radiofrequency generators for this technology; obviously, an ultrasound scanner is necessary in the operating room, as well as argon plasma coagulation, which is usually available it in the operating room where this surgery is performed.

Pablo Sánchez and Lucio S. Uranga: Did you use translaparoscopic ultrasound in all the patients or in what percent?

Enrique Ortiz: Yes, we usually use translaparoscopic ultrasound. We may say that hand-assisted surgery sometimes has to do with the use of ultrasound through the incision for the hand, but in the last stage we implemented the use of laparoscopic ultrasound in all laparoscopic liver resections.

Andrés F. Telleria: I wanted to ask if you have made any chan ges in the management of anesthesia and if you have had any complications related with hypercapnia.

Enrique Ortiz: One of the important parameters in the management of anesthesia is dealing with low pressures, generally below 4, ICP monitoring and use of pneumoperitoneum set at a pressure of no more than 13-14 mm Hg.

Nicolas Guerrini: Do you consider that laparoscopy modifies the different steps of major liver resections?

Enrique Ortiz: We usually start liver resections by first approaching the portal pedicle, the hepatic pedicle; then we usually perform the transection and then we approach the suprahepatic veins. So, in general, the sequence is the same as in the open procedure.

Guillermo E. Pfaffen: My congratulations to the authors. Which was the average number of metastases resected by la paroscopy? And which is the limit you establish for choosing between an open parenchymal sparing surgery and laparos copic liver resection?

Enrique Ortiz: Actually, we have not determined the number of metastases to indicate one technique or the other, but we usually try to evaluate the feasibility of laparoscopic resection and, if it is not possible, we convert to open surgery. In one case of preoperative understaging in terms of the number of lesions, conversion was decided when we found more lesions in the intraoperative ultrasound. So, many times this depends on the findings and on the preoperative evaluation of the technique based on imaging tests.

Carlos R. Colombres: Which tools do you consider indispensable to start with laparoscopic hepatectomy?

Enrique Ortiz: We have already mentioned that intraoperative ultrasound scanner is indispensable to document the lesions previously found and to check that there are no new lesions.

The other important elements have already been mentioned: cutting and coagulation devices, either CUSA or harmonic scalpel; CUSA it is not always available, it often depends on the health care payer, whereas the harmonic scalpel is part of the equipment available in the operating room, but these are the two elements that we usually use for parenchymal transection. The other issue that I also mentioned is the use of white load stapler, i.e vascular load, to complete this type of resection.

Gabriel E. Gondolesi: I would like to ask your advice in two messages for residents or fellows who are starting out in this surgery, so that they can do it safely.

Enrique Ortiz: Thank you, Dr. Gondolesi. I believe that the support of pioneer surgeons in these new technologies is fundamental for training and educating fellows in surgery. Sharing the operating room and their expertise with them can increase their training, and there is an element that we have not talked about, but I think it is important to consider: simulation-based learning in simulation centers for the development of these new technologies.

There are different models of perfused sheep livers for segmental resections or for hepatectomies of sheep livers.

I believe that this is a supplementary aspect that has not been included so far in this communication that I think it is important to consider. Universidad Pontificia de Chile with Dr. Varas has a training center with models precisely for training in different hepatectomies, by means of simulation.

Conclusion by Enrique Ortiz:

Thank you, Dr. Saco. I would like to thank once again Academia Argentina de Cirugía for letting me make this presentation and Dr. Pablo Barros Schelotto and Dr. Gabriel Gondolesi for trusting in me.

* This text belongs to the recording that took place in the session of the Argentine Academy of Surgery, to see the complete session follow this link:https://www.youtube.com/watch?v=3cLAhSx92AU