Impact of laparoscopic surgery on experimental hepatic metastases

The immune response to major gastrointestinal cancer surgery and potential implications for adjuvant immunotherapy

The perioperative period theoretically is a critical time of opportunity for the progression of pre-existing tumour micrometastasis. Therefore,the timing of introducing cancer therapies including chemotherapy, radiation therapy and immunotherapies in the postoperative period is important. A thorough exploration of the perioperative immune events at a cellular level in combination with an intricate review of available clinical rials was conducted to extrapolate the effects of oncological surgery on the perioperative immune milieu.This is timely in view of the recently published Checkmate-577 trial which demonstrated significant disease-free survival in carcinoma of the gastroesophageal junction with the use of adjuvant anti-programmed cell deathprotein 1(PD-1) immunotherapy.This review focusing in particular on perioperative immunosuppression, identifies potential modifiable factors, the effects of perioperative conditioning and optimisation, the most recent trials in the curative setting for Gastrointestinal malignancies and the new treatment avenues possible in the context of the combination of immunotherapy and major oncological gastrointestinal surgery.

Severe portal and systemic acidosis during CO2-laparoscopy compared to helium or gasless laparoscopy and laparotomy in a rodent model: an experimental study

BACKGROUND AND AIMS

This experimental study assesses the influence of different gases and insufflation pressures on the portal, central-venous and peripheral-arterial pH during experimental laparoscopy.

METHODS

Firstly, 36 male WAG/Rij rats were randomized into six groups (n = 6) spontaneously breathing during anaesthesia: laparoscopy using carbon dioxide or helium at 6 and 12 mmHg, gasless laparoscopy and laparotomy. 45 and 90 min after setup, blood was sampled from the portal vein, vena cava and the common femoral artery with immediate blood gas analysis. Secondly, 12 animals were mechanically ventilated at physiological arterial pH during 90 min of laparotomy (n = 6) or carbon dioxide laparoscopy at 12 mmHg (n = 6) with respective blood gas analyses.

RESULTS

Over time, in spontaneously breathing rats, carbon dioxide laparoscopy caused significant insufflation pressure-dependent portal acidosis (pH at 6 mmHg, 6.99 [6.95-7.04] at 45 min and 6.95 [6.94-6.96] at 90 min, pH at 12 mmHg, 6.89 [6.82-6.90] at 45 min and 6.84 [6.81-6.87] at 90 min; p < 0.05) compared to laparotomy (portal pH 7.29 [7.23-7.30] at 45 min and 7.29 [7.20-7.30] at 90 min; p > 0.05). Central-venous and peripheral-arterial acidosis was significant but less severely reduced during carbon dioxide laparoscopy. Laparotomy, helium laparoscopy and gasless laparoscopy showed no comparable acidosis in all vessels. Portal and central-venous acidosis during carbon dioxide laparoscopy at 12 mmHg was not reversible by mechanical hyperventilation maintaining a physiological arterial pH (pH portal 6.85 [6.84-6.90] (p = 0.004), central-venous 6.93 [6.90-6.99] (p = 0.004), peripheral-arterial 7.29 [7.29-7.31] (p = 0.220) at 90 min; Wilcoxon-Mann-Whitney test).

CONCLUSION

Carbon dioxide laparoscopy led to insufflation pressure-dependent severe portal and less severe central-venous acidosis not reversible by mechanical hyperventilation.

Meta-analysis of laparoscopic versus open liver resection for colorectal liver metastases

Background

To compare surgical and oncological outcomes of laparoscopic versus open liver resection for colorectal liver metastases.

Results

A total of 14 retrospective studies with 1679 colorectal liver metastases patients were analyzed: 683 patients treated with laparoscopic liver resection and 996 patients with open liver resection. With respect to surgical outcomes, laparoscopic compared with open liver resection was associated with lower blood loss (MD, -216.7, 95% CI, -309.4 to -124.1; P < 0.00001), less requiring blood transfusion (OR, 0.36; 95% CI, 0.23 to 0.55; P < 0.00001), lower postoperative complication morbidity (OR, 0.61; 95% CI, 0.47 to 0.80; P = 0.003), and shorter hospitalization time (MD, -3.85, 95% CI, -5.00 to -2.71; P < 0.00001). However, operation time and postoperative mortality were no significant difference between the two approaches. With respect to oncological outcomes, laparoscopic liver resection group was prone to lower recurrence rate (OR, 0.78; 95% CI, 0.61−0.99; P = 0.04), but surgical margins R0, overall survival and disease-free survival were no significant difference.

Materials and Methods

We performed a systematic search in MEDLINE, EMBASE, and CENTRAL for all relevant studies. All statistical analysis was performed using Review Manager version 5.3. Dichotomous data were calculated by odds ratio (OR) and continuous data were calculated by mean difference (MD) with 95% confidence intervals (CI).

Conclusions

Laparoscopic and open liver resection for colorectal liver metastases have the same effect on oncological outcomes, but laparoscopic liver resection achieves better surgical outcomes.

Dose-dependent role of novel agents emodin and BTB14431 in colonic cancer treatment in rats

BACKGROUND

BTB14431 is an in silico homolog to emodin. Both were found to possess anti-tumor effects in vitro. The aim of this work was to analyze the tumor suppressing effects of both molecules in an intraperitoneal (ip) and intravenous (iv) treated rat model (WAG-Rij).

METHODS

A tumor cell suspension (CC531) was applied at the cecum after laparotomy and at the back. The rats where treated twice a day over 1 week with BTB14431, emodin and isotone sodium chloride solution (control). Treatment was applied iv or ip in a variety of dosages. Peripheral blood samples were taken before tumor application and on day 7. Twenty-one days after the last day of therapy animals were euthanized and tumor growth was evaluated.

RESULTS

Data showed an insignificant decrease of tumor growth after iv and ip treatment with low doses of BTB14431 and emodin. Differential blood analysis showed apoptosis. Increased doses of emodin clearly raised mortality rate.

CONCLUSIONS

Apoptosis was verified but no tumor-suppressing effects could be observed for iv and ip treatment with both agents in contrast to in vitro studies in our model. Establishing a successful ip treatment model for emotion and BTB14331 requires further studies.

Long-term and perioperative outcomes of laparoscopic versus open liver resection for colorectal liver metastases with propensity score matching: a multi-institutional Japanese study

BACKGROUND

The aim of the present study was to clarify the surgical outcome and long-term prognosis of laparoscopic liver resection (LLR) compared with conventional open liver resection (OLR) in patients with colorectal liver metastases (CRLM).

METHODS

A one-to-two propensity score matching (PSM) analysis was applied. Covariates (P < 0.2) used for PSM estimation included preoperative levels of CEA and CA19-9; primary tumor differentiation; primary pathological lymph node metastasis; number, size, location, and distribution of CRLM; existence of extrahepatic metastasis; extent of hepatic resection; total bilirubin and prothrombin activity levels; and preoperative chemotherapy. Perioperative data and long-term survival were compared.

RESULTS

From 2005 to 2010, 1,331 patients with hepatic resection for CRLM were enrolled. By PSM, 171 LLR and 342 OLR patients showed similar preoperative clinical characteristics. Median estimated blood loss (163 g vs 415 g, P < 0.001) and median postoperative hospital stay (12 days vs 14 days; P < 0.001) were significantly reduced in the LLR group. Morbidity and mortality were similar. Five-year rates of recurrence-free, overall, and disease-specific survival did not differ significantly. The R0 resection rate was similar.

CONCLUSIONS

In selected CRLM patients, LLR is strongly associated with lower blood loss and shorter hospital stay and has equivalent long-term survival comparable with OLR.

Systematic review of laparoscopy-assisted versus open gastrectomy for advanced gastric cancer

OBJECTIVE

The study compared laparoscopy-assisted gastrectomy (LAG) with open gastrectomy (OG) in the management of advanced gastric cancer (AGC).

METHODS

Literature search was performed in the Medline, Embase, and Cochrane Library databases to identify control studies that compared LAG and OG for AGC. A meta-analysis was conducted to examine the surgical safety and oncologic adequacy, using the random-effect model.

RESULTS

Seven eligible studies including 815 patients were analyzed. LAG was associated with less blood loss, less use of analgesics, shorter time of flatus and periods of hospital stay, but longer time of operation. The incidence of most complications was similar between the two groups. However, LAG was associated with a lower rate of pulmonary infection (odds ratio (OR) 0.19; 95% confidence interval (CI) 0.05 to 0.68; P<0.05). No significant differences were noted in terms of the number of harvested lymph nodes (weighted mean difference (WMD) 1.165; 95% CI -2.000 to 4.311; P>0.05), overall mortality (OR 0.65; 95% CI 0.39 to 1.10; P>0.05), cancer-related mortality (OR 0.64; 95% CI 0.32 to 1.25; P>0.05), or recurrence (OR 0.62; 95% CI 0.33 to 1.16; P>0.05).

CONCLUSIONS

LAG could be performed safely for AGC with adequate lymphadenectomy and has several short-term advantages compared with conventional OG. No differences were found in long-term outcomes. However, these results should be validated in large randomized controlled studies (RCTs) with sufficient follow-up.

Minimally invasive surgery for serosa-positive gastric cancer (pT4a) in patients with preoperative diagnosis of cancer without serosal invasion

BACKGROUND

Although surgeons normally use minimally invasive surgery (MIS) for patients with early gastric cancer, in Korea and Japan the procedure is also indicated for serosa-negative tumors. Serosal invasion is regarded to be a potential risk factor for peritoneal dissemination as a result of the effect of pneumoperitoneum and tumor manipulation during the operation. We compared operative outcomes between MIS and conventional open surgery for serosa-involved advanced gastric cancer patients who had a preoperative diagnosis of cancer without serosal invasion.

METHODS

A total of 61 patients (39 patients treated by MIS and 22 by open surgery) treated between 2003 and 2009 who were first diagnosed preoperatively as serosa negative on the basis of computed tomography, endoscopy, and endoscopic ultrasound but then diagnosed as serosa positive upon final pathology were studied. We retrospectively compared recurrence and survival between the two treatment groups.

RESULTS

Clinicopathologic characteristics, clinical stage, extent of surgery, and short-term operative outcome did not differ between the groups. 5-year overall survival (73.5 vs. 67.5 %, p = 0.518, respectively) and disease-free survival (67.8 vs. 54.2 %, p = 0.296, respectively) were comparable between the MIS and open surgery groups. There were recurrences in 12 patients in the MIS group and 11 patients in the open surgery group, with a median follow-up period of 64 months. Recurrence patterns did not differ between the groups; moreover, MIS did not increase peritoneal recurrences compared to open surgery (42.0 vs. 54.5 %, p = 0.537, respectively). In multivariate analyses, the type of surgery was not an independent prognostic factor.

CONCLUSIONS

Similar survival and recurrence patterns were observed in advanced gastric cancer patients preoperatively diagnosed as serosa negative who were treated either by MIS or open surgery. MIS may be safely applied in patients with serosa-positive tumors.

Laparoscopic versus open resection of hepatic colorectal metastases

BACKGROUND

This study was undertaken to assess the safety and efficacy of laparoscopic versus open resection of hepatic colorectal metastases (CRM).

METHODS

We reviewed retrospectively of all patients undergoing initial resection of CRM at a single institution between 1995 and 2010. The study cohort consisted of all patients undergoing laparoscopic resection and a cohort of patients undergoing open resection matched on a 4:1 basis by propensity scoring. Variables analyzed included patient and tumor characteristics, short-term outcomes, and OS and disease-free (DFS) survivals.

RESULTS

The 35 patients in the laparoscopic cohort and 140 patients in the open cohort were equivalent in terms of age, Charlson Comorbidity Index, tumor characteristics, and Clinical Risk Score. Similar proportions of patients in the laparoscopic and open groups underwent synchronous colectomy (9% in both; P = .976) and major hepatectomy (54% vs 51%; P = .705). Blood loss (202 vs 385 mL; P < .001), complications (23% vs 50%; P = .004), and duration of stay (4.8 vs 8.3 days; P < .001) were less in the laparoscopic cohort. Five-year OS (36% vs 42%; P = .818) and DFS (15% vs 22%; P = .346) were also similar in the laparoscopic and open groups.

CONCLUSION

Laparoscopic resection of hepatic CRM seems to be a beneficial alternative to open surgery in appropriately selected patients.

Comparison of short-term outcomes and perioperative systemic immunity of laparoscopy-assisted and open radical gastrectomy for gastric cancer

OBJECTIVE

To compare the perioperative systemic immunity of laparoscopy-assisted and open radical gastrectomy for gastric cancer.

METHODS

Patients with gastric adenocarcinoma proven by endoscopy and biopsy were eligible, while patients with preoperative staging of T4, N2-3, or M1 were excluded. Eligible patients willing to undertake laparoscopic surgery in the consecutive cohort were assigned to the laparoscopy-assisted gastrectomy (LAG) group, while concurrent patients were assigned to the conventional open gastrectomy (OG) group. All operations were performed with the intention of radical resection. Various immunological parameters were tested in peripheral venous blood collected at preoperative 1(st) day and postoperative 2(nd) day (POD2) and 7(th) day (POD7). SPSS 13.0 software was used for statistical analysis.

RESULTS

Thirty patients were included, 15 each in the LAG and OG groups. The general characteristics and short-term outcomes (harvested lymph nodes number, hospital stay, complications, and mortality rate) of the two groups were comparable, but the operation time was significantly longer in LAG (P = 0.001). Moreover, intergroup comparisons indicated no significant differences between the groups in levels of neutrophils, T-lymphocytes, natural killer cells, IgG, IgM, IgA, C3, C4, interleukin-6, or interleukin-10 at any time point (P>0.05). However, there was a gradual decrease in natural killer cell count in the LAG group up to POD7 (P = 0.008).

CONCLUSION

The changes in systemic immunity markers were comparable between laparoscopy-assisted and open gastrectomy for gastric cancer. However, there was a trend of suppression of natural killer cells in the laparoscopy-assisted gastrectomy group.

Microcirculation of secondary bone tumors in vivo: the impact of minor surgery at a distal site

Microcirculatory properties of tumors play a pivotal role in tumor progression and inefficacy of therapies. It has been hypothesized that surgical interventions result in an accelerated tumor growth by increasing the level of pro-angiogenic cytokines with subsequent amplification of tumor angiogenesis. To characterize the microvascular properties of secondary bone tumors in vivo and determine the impact of minor surgery on the microcirculation, we performed intravital microscopy over 25 days using a xenograft model of breast cancer tumor growth (MCF-7) in bone. After engraftment of tumors the mice were treated with a mastectomy versus no surgery. Tumor growth was accompanied by angiogenic sprouting and decreased vascular diameters while blood flow rate and tumor perfusion remained constant. Mastectomy initially led to a significant reduction of functional vascular density, increased vascular diameter, and decreased blood flow velocities. However, neither tumor growth nor tissue perfusion was different between the groups. The presented study corroborates the assumption that tumor microcirculation in bone exhibits similar time-dependent alterations compared to soft tissue tumors. A minor surgical intervention did not change tumor growth kinetics however microcirculatory properties were altered. Whether major surgery has an impact on tumor growth in bone should be clarified in further studies.

Long-term outcomes after laparoscopy-assisted gastrectomy for advanced gastric cancer: analysis of consecutive 106 experiences

BACKGROUND AND OBJECTIVES

The purpose of this retrospective study is to suggest the possibility of laparoscopy-assisted gastrectomy (LAG) for advanced gastric cancer (AGC) through long-term outcomes.

METHODS

Of 283 patients with gastric cancer who underwent LAG with extraperigastric (D2) lymphadenectomy between January 2004 and February 2009, 106 were pathologically confirmed with AGC and analyzed.

RESULTS

There were 75 men and 31 women, with a mean age of 61.4 +/- 11.7 years. There were 32 total gastrectomies and 74 distal gastrectomies with D2 lymphadenectomy. The mean tumor size was 4.8 +/- 2.6 cm. The mean numbers of retrieved and metastatic lymph nodes were 34.3 +/- 15.3 and 5.4 +/- 8.7, respectively. There was no lymph node metastasis in 44 patients (41.5%), and there were 35 grade T2a, 51 T2b, and 20 T3 lesions. There were 10 operation-related morbidities (9.4%) and one postoperative death (0.9%) from hepatic failure. The overall and disease-free survival rates were 81.4% and 72.4%, respectively. Tumors recurred in 17 patients (16.0%) during the follow-up periods (median 21.5 months; range 2-60).

CONCLUSIONS

LAG for AGC might be considered as a minimally invasive treatment in selected cases, but further study comparing it with open gastrectomy will be needed.

Unique localization of circulating tumor cells in patients with hepatic metastases

PURPOSE

There are few data on the impact of immediate and differing surgical interventions on circulating tumor cells (CTCs), nor their compartmentalization or localization in different anatomic vascular sites.

PATIENTS AND METHODS

CTCs from consecutive patients with colorectal liver metastases were quantified before and immediately after open surgery, laparoscopic resection, open radiofrequency ablation (RFA), or percutaneous RFA. For individuals undergoing open surgery, either hepatic resections or open RFA, CTCs were examined in both systemic and portal circulation by measuring CTCs in samples derived from the peripheral vein, an artery, the hepatic portal vein, and the hepatic vein.

RESULTS

A total of 29 consecutive patients with colorectal liver metastases with a median age of 55 years (range, 30 to 88 years) were included. CTCs were localized to the hepatic portosystemic macrocirculation with significantly greater numbers than in the systemic vasculature. Surgical procedures led to a statistically significant fall in CTCs at multiple sites measured. Conversely, RFA, either open or percutaneous, was associated with a significant increase in CTCs.

CONCLUSION

Surgical resection of metastases, but not RFA, immediately decreases CTC levels. In patients with colorectal liver metastases, CTCs appear localized to the hepatic (and pulmonary) macrocirculations. This may explain why metastases in sites other than the liver and lungs are infrequently observed in cancer.

The impact of carbon dioxide pneumoperitoneum on liver regeneration after liver resection in a rat model

BACKGROUND

In recent years, laparoscopic hepatic resection is performed by an increasing number of surgeons. Despite many advantages of the laparoscopic procedure, it is unclear whether the pneumoperitoneum affects the postoperative liver regeneration after liver resection. The current study aimed to investigate the influence of a carbon dioxide (CO(2)) pneumoperitoneum on liver regeneration in a rat model.

METHODS

In this study, 60 male Wistar rats were subjected to 70% partial hepatic resection. Of these 60 animals, 30 underwent preoperative pneumoperitoneum at 9 mmHg for 60 min. After hepatic resection, the rats were killed at 12, 24, and 48 h, and on days 4 and 7. The outcome parameters were hepatocellular injury (plasma aminotransferases), oxidative stress (plasma malondialdehyde), interleukin-6 (IL-6), and liver regeneration (mitotic index, KI-67; regenerating liver mass).

RESULTS

The mitotic index was significantly lower in the pneumoperitoneum group than in the group without pneumoperitoneum at all time points (p < 0.05). In the pneumoperitoneum group, KI-67 was significantly lower on day 4 (p < 0.05). The liver regeneration rate was significantly lower for the animals with pneumoperitoneum on days 2 and 4 (p < 0.05). The postoperative hepatocellular injury was significantly greater after pneumoperitoneum at 12, 24, and 48 h (p < 0.05). Plasma malondialdehyde and IL-6 were significantly higher in the pneumoperitoneum group at 24 h and on day 4 (p < 0.05).

CONCLUSION

This study showed that pneumoperitoneum before extended liver resection impaired postoperative liver regeneration. Oxidative stress reaction and hepatocellular damage was markedly higher after pneumoperitoneum. Further investigations, especially with patients that have impaired liver function, are necessary for clinical consequences to be drawn from these results.

A series of laparoscopic liver resections with or without HALS in patients with hepatic tumors

BACKGROUND

Differences were compared between laparoscopic surgery with and without hand-assisted laparoscopic technique (HALS) in order to assess whether HALS is a safe and feasible alternative to laparotomy and to determine what factors contributed to successful laparoscopic liver surgery.

METHOD

From a total of 416 liver resections, 45 patients with 46 hepatic tumors were chosen for laparoscopic liver resection with or without a hand-assisted technique. For each patient, her/his surgical duration, intraoperative blood loss, tumor size and location, hospital stay after surgery, mortality, and morbidity were recorded for analysis.

RESULTS

The 45 surgical laparoscopic liver resections included 19 left lateral lobectomies, three hemihepatectomies, three segmentectomies, and 21 partial hepatectomies. A HALS was used more frequently in the right posterior group (14/16) than in the anterior group (6/29). There was no notable difference between these two groups in terms of tumor size, mean surgical time, blood loss during surgical procedure, hospital stay after surgery, and occurrence of complication.

CONCLUSION

Surgical results between HALS and non-HALS usage were similar except for higher blood loss with HALS, higher use of HALS when liver cirrhosis was present, and less likelihood of using HALS when there was a superficial location of the tumor or lesion.

Laparoscopy-assisted distal gastrectomy with D2 lymphadenectomy for T2b advanced gastric cancers: three years' experience

BACKGROUND

The application of laparoscopy-assisted distal gastrectomy (LADG) with advanced gastric cancer (AGC) is a controversial. The purpose of this study was to assess the possibility of using LADG application to AGC.

METHODS

Of 160 patients who underwent LADG with D2 lymphadenectomy between April 2004 and March 2007, 26 patients with stage pT2b were selected and compared to 25 patients of the same stage who underwent open distal gastrectomy (ODG) within same period. The comparison was based on the clinicopathologic characteristics, surgical outcome, and follow-up results.

RESULTS

There was no significant difference between LADG and ODG groups in most operation results including complication rates (15.4% vs. 16.0%, P = 1.000) except for less average loss of blood (160.0 ml vs. 215.0 ml, P = 0.012) and longer average operating time (255.0 min vs. 190.0 min, P < 0.001) in LADG. Three-year overall survival rates (88.2% vs. 77.2%; P = 0.246) and disease-free survival rates (71.4% vs. 53.4%; P = 0.757) were not significantly different in LADG and ODG groups.

CONCLUSIONS

The early results of current study suggest that LADG for AGC is technically safe and oncologically feasible. Therefore, LADG should be considered as a curative treatment for AGC not exposed to serosa.

Enhanced tumour growth and impaired cellular antitumoural defense in hepatic colorectal carcinoma metastasis in rats after laparoscopy compared to open surgery

BACKGROUND

This study aims to assess postoperative hepatic growth of colorectal adenocarcinoma metastasis and peritumoural macrophage counts after laparoscopy in an experimental animal model.

METHODS

Thirty male syngenic WAG/Rij rats were randomised into two surgical groups: laparoscopy (LS; n = 15) using CO(2) at 12 mmHg and laparotomy (LT; n = 15; negative control) during an operating time of 90 min. At 45 min after setup, CC531s colon adenocarcinoma cells were injected into two liver lobes. Postoperative tumour volumes were determined by abdominal magnetic resonance imaging (MRI) and computed three-dimensional volumetry. Peritumoural macrophages were counted by local stereology using a confocal laser-scanning fluorescence microscope.

RESULTS

The median postoperative tumour volume was significantly higher after LS in both lobes (L): after 10, 15 and 20 days in L2 and L5: 24/12, 54/38, 275/62 mm(3) and 0/0, 15/11, 55/24 mm(3) (LS/LT). Significantly fewer peritumoural macrophages were found after LS at all postoperative time points (Mann-Whitney: p < 0.05).

CONCLUSIONS

Increased hepatic growth of colorectal adenocarcinoma metastasis and impaired cellular antitumoural defence after LS cast doubt on the use of LS in colorectal cancer and needs further clinical investigation.

Signs of reperfusion injury following CO2 pneumoperitoneum: an in vivo microscopy study

BACKGROUND

During laparoscopic surgery, pneumoperitoneum is generally established by means of carbon dioxide (CO(2)) insufflation which may disturb hepatic microperfusion. It has been suggested that the desufflation at the end of the procedure creates a model of reperfusion in a previously ischemic liver, thus predisposing it to reperfusion injury.

METHODS

To study the effects of pneumoperitoneum on hepatic microcirculation, Sprague-Dawley rats underwent pneumoperitoneum with an intraabdominal pressure of 8 or 12 mmHg for 90 min. Subsequently, in vivo microscopy was performed to assess intrahepatic microcirculation and transaminases were measured to index liver injury.

RESULTS

A CO(2) pneumoperitoneum of 8 mmHg did not change serum transaminases; however, further increase of intraperitoneal pressure to 12 mmHg significantly increased AST, ALT, and LDH measured after desufflation to almost 1.5 times as much as control values of 49 +/- 5 U/L, 31 +/- 3 U/L, and 114 +/- 12 U/L. In parallel, in all subacinar zones the permanent adherence of both leukocytes and platelets to the endothelium increased by about sixfold and threefold, respectively. Furthermore, Kupffer cells labeled with latex beads as an index for their activation were significantly increased compared to controls.

CONCLUSION

This in vivo observation demonstrated traces of reperfusion injury in liver induced by the insufflation and desufflation of CO(2 )pneumoperitoneum. The clinical relevance of this finding and the issue of using hepatoprotective substances to prevent this injury should be further investigated.

Laparoscopic liver resection for hepatocellular carcinoma

BACKGROUND

Single, small hepatocarcinomas (HCC) are still an indication for partial liver resection in patients ineligible for transplantation. Anatomical resections are recommended for oncological reasons. The mini-invasive approach of laparoscopy should minimize hepatic and parietal injury, thereby decreasing the risk of liver failure and ascites. However, the oncological results of this approach and its presumed benefits remain undemonstrated. We evaluated the short- and midterm results of laparoscopic liver resections for HCC.

METHODS

Between 1999 and 2006, we performed 32 laparoscopic liver resections for HCC. Mean tumor size was 3.8 +/- 2 cm and the mean age of the patients was 65 +/- 11 years. Twenty-two patients had cirrhosis (21 Child A and one Child C). Operative and postoperative results were analyzed, together with recurrence and survival rates.

RESULTS

We carried out 13 unisegmentectomies, nine bisegmentectomies, one trisegmentectomy, two right hepatectomies, one left hepatectomy, and six atypical resections. The duration of the operation was 231 +/- 101 minutes. Conversion to laparotomy was required in three patients (9%), none in emergency situations. Mean blood loss was 461 ml, with five patients (15.6%) requiring blood transfusion. The mean surgical margin was 10.4 mm. One cirrhotic patient (Child C) underwent surgery for a partially ruptured tumor and died of liver failure. Two patients had ascites and no transient liver failure occurred in the other 19 cirrhotic patients. Mean hospital stay was 7.1 days. During a mean follow-up of 26 months, 10 patients (31%) presented recurrence within the liver. None of the patients had peritoneal carcinomatosis or trocar site recurrence. Three-year overall and disease-free survival rates were 71.9% and 54.5%, respectively.

CONCLUSIONS

Laparoscopic liver resection for HCC is feasible and well tolerated. Midterm survival and recurrence rates are similar to those after laparotomy.

Laparoscopic liver resection: results for 70 patients

BACKGROUND

Laparoscopy is slowly becoming an established technique for liver resection. This procedure still is limited to centers with experience in both hepatic and laparoscopic surgery. Preliminary reports include mainly minor resections for benign liver conditions and show some advantage in terms of postoperative recovery. The authors report their experience with laparoscopic liver resection, the evolution of the technique, and the results.

METHODS

From 1999 to 2006, 70 laparoscopic liver resections were performed using a procedure similar to resection by laparotomy.

RESULTS

There were 38 malignant tumors (54%) and 32 benign lesions (46%). The malignant tumors were mainly hepatocellular carcinomas (19 of 24 patients had cirrhosis). The tumor mean size was 3.8 +/- 1.9 cm (range, 2.2-8 cm). There were 19 major hepatectomies, 34 uni- or bisegmentomies, and 17 atypical resections. The operative time was 227 +/- 109 min. Conversion to laparotomy was required for seven patients (10%), mainly for continuous bleeding during transection. Nine patients (13%) required blood transfusion. One patient had both brisk bleeding and gas embolism from a tear in the section line of the right hepatic vein requiring laparoscopic suture. Blood loss and transfusion requirements were significantly lower in recent than in early cases and in resections with prior vascular control than in those without such control. Postoperative complications were experienced by 11 patients (16%), including one bleed from the hepatic stump requiring hemostasis and two subphrenic collections requiring percutaneous drainage. One cirrhotic patient died of liver failure after resection of a partially ruptured tumor. No ascites was observed in other cirrhotic patients. The mean hospital stay was 5.9 days.

CONCLUSION

The study results confirm that laparoscopic liver resection, including major hepatectomies, can be safely performed by laparoscopy.

The targeting of phosphoinositide-3 kinase attenuates pulmonary metastatic tumor growth following laparotomy

OBJECTIVE

We aimed to characterize a potential role for phosphatidylinositol 3-kinase (PI3k) in leading to accelerated postoperative metastatic tumor growth.

BACKGROUND

PI3k enhances tumor cell survival in part by phosphorylating Akt and reducing apoptosis. Postoperatively, apoptosis is reduced within local recurrences and distant metastases. This reduction is associated with the phenomenon of accelerated postoperative tumor growth.

METHODS

Balb/c mice underwent a tail vein injection of 1x10 metastatic murine mammary adenocarcinoma 4T1 cells. Animals were divided into the following treatment groups (n=10/group): group A, controls; group B, DMSO intraperitoneally (IP) daily from days 14 to 21; group C, IP LY294002 daily from days 14 to 21; group D, laparotomy only; group E, laparotomy followed by IP DMSO for 7 days; and group F, laparotomy followed by LY294002 IP for 7 days. All laparotomies were performed on day 14. Animals were killed at day 28. Metastatic tumor burden was assessed using the lung/body weight ratio and a histologic metastatic index. Mitotic counts and apoptotic indices were established using a combination of hematoxylin and eosin histology and TUNEL immunohistochemistry. A parallel survival study was performed, and PI3k activity was assessed using western blots for phospho-Akt.

RESULTS

Laparotomy was associated with increased systemic tumor burden (P=0.001). Postoperatively, LY294002 significantly attenuated metastatic tumor growth (P<0.001). Effective PI3k inhibition was confirmed by demonstrating a reduced Akt phosphorylation. Moreover, PI3k inhibition led to reduced proliferation, increased apoptosis (P<0.001), and enhanced postoperative survival (P<0.001).

CONCLUSIONS

Targeting PI3k with postoperative LY294002 significantly attenuates the acceleration in postoperative metastatic tumor growth seen following laparotomy.

Cancer surgery: risks and opportunities

In the recent past, several papers have pointed to the possibility that tumour removal generates a permissive environment in which tumour growth is potentiated. This phenomenon has been coined "perioperative tumour growth" and whilst it represents a departure in terms of our attitude to the surgical process, this concept was first hinted at by Paget(1) himself. Despite this, the time interval immediately before and after cancer surgery (i.e. the perioperative period) remains an underutilised interval during which chemotherapeutic regimens are rarely implemented. Herein, we present a summarised review of the literature that supports the concept that tumour removal may potentiate the growth of residual neoplastic disease. We also outline current knowledge regarding underlying mechanisms and in this manner highlight potential therapeutic entry points. Finally, we emphasise the urgent need for trials of agents that could protect patients against the harmful host-tumour interactions that may occur during the perioperative period.

Liver metastasis and ICAM-1 mRNA expression in the liver after carbon dioxide pneumoperitoneum in a murine model

BACKGROUND

Liver metastasis of colorectal malignancies is an important prognostic factor. Several studies have demonstrated that carbon dioxide (CO2) pneumoperitoneum enhances liver metastasis in animal models. Little is known about intercellular adhesion molecule-1 (ICAM-1) and tumor necrosis factor-alpha (TNF-(alpha) mRNA expression in the liver after CO2 pneumoperitoneum.

METHODS

Forty-five male BALB/c mice were randomly divided into three groups after intra-splenic tumor cell (colon 26) inoculation and the following procedures were performed: CO2 pneumoperitoneum (n = 15), open laparotomy (n = 15), and anesthesia alone (n = 15). On day 7 after each procedure, the livers were excised and the number and diameter of the tumor nodules and the cancer index score were determined. Another 90 male BALB/c mice were randomly divided into three groups as described above, and they underwent each procedure (n = 30 each). After each procedure, the livers were excised on days 0, 1, 3, and ICAM-1 and TNF-alpha mRNA expression were examined by real-time RT-PCR using SYBR Green I.

RESULTS

The number of tumor nodules and the cancer index score were larger in the CO2 pneumoperitoneum group than in the control group (p < 0.05). The mean diameter of the tumor nodules was not different among the three groups. The expression of ICAM-1 in the CO2 pneumoperitoneum group was higher than that in the other groups on day 1 (p < 0.05), and the TNF-alpha mRNA was higher than that in the control group on day 1 (p < 0.05).

CONCLUSIONS

CO2 pneumoperitoneum enhances liver metastasis compared with anesthesia alone, and ICAM-1 expression in the liver after the pneumoperitoneum plays an important role in establishing liver metastasis in a murine model.

Morphological changes in hepatic vascular endothelium after carbon dioxide pneumoperitoneum in a murine model

BACKGROUND

Liver metastasis is an important prognostic factor in advanced colorectal cancer. Several studies have demonstrated that carbon dioxide (CO2) pneumoperitonem enhances liver metastasis in an animal model. In the present study, we used scanning electron microscopy (SEM) to investigate morphological changes in hepatic vascular endothelium after CO2 pneumoperitoneum in a murine model.

METHODS

Thirty-three male BALB/c mice were randomized to undergo pneumoperitoneum (CO2, air, or helium), open laparotomy, and anesthesia alone. After each procedure, the animals' livers were excised at days 0, 1, and 3 and examined by SEM.

RESULTS

In the CO2 pneumoperitoneum group, we observed rough surface and derangement of the hepatic vascular endothelial cells and intercellular clefts on day 1. In the other groups, no major morphologic changes were observed at any time.

CONCLUSIONS

Hepatic vascular endothelium changes after CO2 pneumoperitoneum. Such characteristic changes may play an important role in establishing liver metastasis after CO2 pneumoperitoneum.

Insufflation profile and body position influence portal venous blood flow during pneumoperitoneum

BACKGROUND

We investigated changes in portal venous blood flow (PVBF) during carbon dioxide (CO2) pneumoperitoneum to evaluate the effects of different insufflation profiles and body positions.

METHODS

An established rat model was extended by implanting a portal vein flow probe that would enable us to measure PVBF for 60 min [t0-t60] in animals subjected to a CO2 pneumoperitoneum with an intraabdominal pressure (IAP) of 9 mmHg. Forty-eight male Sprague-Dawley rats were randomized into the following four experimental and two control groups: decompression group D1 ( n = 8), desufflation for 1 min every 14 min; decompression group D2 ( n = 8), desufflation for 5 min, after 27 min; position group P1 ( n = 8), 35 degrees head-up position; position group P2 ( n = 8), 35 degrees head-down position; negative control group C1 ( n = 8), no insufflation; positive control group C2 ( n = 8), constant IAP of 9 mmHg for 60 min.

RESULTS

Pneumoperitoneum and body positions, respectively, reduced PVBF [t1-t60] significantly ( p < 0.001) by 32.0% C2, 32.8% D1, 31.1% D2, 40.8% P1, and 48.5% P2, as compared to PVBF at t0 in each group. There was a significant difference in PVBF reduction between P1 and P2 and also between C2 and both P1 and P2 ( p < 0.04).

CONCLUSIONS

CO2 pneumoperitoneum reduces PVBF significantly (>30%). Extreme body positions (35 degrees tilt) significantly intensify PVBF reduction. PVBF reduction is significantly more dramatic in subjects placed in a 35 degrees head-down position. Short desufflation periods did not improve mean PVBF, but it may have beneficial immunological and oncological effects that warrant further investigation.

Insufflation profile and body position influence portal venous blood flow during pneumoperitoneum

BACKGROUND

We investigated changes in portal venous blood flow (PVBF) during carbon dioxide (CO2) pneumoperitoneum to evaluate the effects of different insufflation profiles and body positions.

METHODS

An established rat model was extended by implanting a portal vein flow probe that would enable us to measure PVBF for 60 min [t0-t60] in animals subjected to a CO2 pneumoperitoneum with an intraabdominal pressure (IAP) of 9 mmHg. Forty-eight male Sprague-Dawley rats were randomized into the following four experimental and two control groups: decompression group D1 ( n = 8), desufflation for 1 min every 14 min; decompression group D2 ( n = 8), desufflation for 5 min, after 27 min; position group P1 ( n = 8), 35 degrees head-up position; position group P2 ( n = 8), 35 degrees head-down position; negative control group C1 ( n = 8), no insufflation; positive control group C2 ( n = 8), constant IAP of 9 mmHg for 60 min.

RESULTS

Pneumoperitoneum and body positions, respectively, reduced PVBF [t1-t60] significantly ( p < 0.001) by 32.0% C2, 32.8% D1, 31.1% D2, 40.8% P1, and 48.5% P2, as compared to PVBF at t0 in each group. There was a significant difference in PVBF reduction between P1 and P2 and also between C2 and both P1 and P2 ( p < 0.04).

CONCLUSIONS

CO2 pneumoperitoneum reduces PVBF significantly (>30%). Extreme body positions (35 degrees tilt) significantly intensify PVBF reduction. PVBF reduction is significantly more dramatic in subjects placed in a 35 degrees head-down position. Short desufflation periods did not improve mean PVBF, but it may have beneficial immunological and oncological effects that warrant further investigation.

Laparoscopic enhancement of tumour cell binding to the peritoneum is inhibited by anti-intercellular adhesion molecule-1 monoclonal antibody

BACKGROUND

There still remain some concerns over the phenomenon of port-site metastases (PSM) after laparoscopic surgery. The aim of this study was to investigate the effect of the pneumoperitoneum on tumor-mesothelial cell interactions.

METHODS

The adhesion of a colon carcinoma cell line to a mesothelial cell monolayer exposed to carbon dioxide, helium, or air was assessed using an in vitro adhesion assay. Changes in adherence were correlated with alterations in cell surface molecule expression by the mesothelial cells using flow cytometry after exposure to the different environments.

RESULTS

Exposure of the mesothelial cells to an in vitro pneumoperitoneum significantly enhanced tumor cell binding to the mesothelial cell monolayer. No differences in cell viability were observed between the groups. This was associated with increased expression of mesothelial intercellular adhesion molecule-1 (ICAM-1) mediated by nuclear factor kappa-B. The enhanced adhesion was abolished by ICAM-1 inhibition.

CONCLUSIONS

This study demonstrated that the laparoscopic environment increases the susceptibility of the mesothelium to tumor cell adherence, and this may be explained by changes in ICAM-1 expression.

The impact of carbon dioxide and helium insufflation on experimental liver metastases, macrophages, and cell adhesion molecules

BACKGROUND

Laparoscopic insufflation, proposed to reduce hepatic perfusion, may enhance hepatic tumor spread. It is unknown whether intraabdominal pressure or the gas itself influences hepatic tumor growth. In contrast to carbon dioxide, the alternative gas helium is believed to reduce malignant cell growth.

METHODS

For this study, 36 WAG/Rij rats were randomized in two experimental groups. The animals were laparoscopically insufflated with carbon dioxide ( n = 19) or helium gas ( n = 17). Liver metastases were induced by laparoscopic injection of 50,000 CC531 cells into the portal vein. Macroscopic and microscopic analyses of CC531 tumor cell growth, macrophages, and CD44v5, v6 were performed. Data were analyzed by Kruskal-Wallis, Dunn, and Holm tests.

RESULTS

No significant differences in macroscopic and microscopic analyses were found between carbon dioxide and helium gas insufflations ( p > 0.05).

CONCLUSIONS

Recent studies have shown that insufflation with carbon dioxide may result in increased hepatic tumor growth. The current study comparing carbon dioxide and helium insufflations could show for the first time either oncologic nor immunologic differences in relation to the liver between two different gases. In conclusion, elevated intraabdominal pressure during gas insufflation is responsible for hepatic disadvantages during pneumoperitoneum, not carbon dioxide gas itself.

The effects of CO2 pneumoperitoneum on the survival of women with persistent metastatic ovarian cancer

OBJECTIVES

The effects of CO(2) pneumoperitoneum on the survival of women with metastatic ovarian cancer have not been documented. We sought to describe the survival of women with persistent stage III-IV ovarian cancer as documented by positive second-look laparoscopy or laparotomy and to see whether the laparoscopic approach with CO(2) pneumoperitoneum has a negative effect on overall survival.

METHODS

We conducted a retrospective review of all patients with FIGO stage III-IV invasive epithelial ovarian cancer who were found to have persistent disease at second-look surgery. All patients underwent primary surgery followed by intravenous chemotherapy and were clinically without evidence of disease prior to second-look surgery. Second-look laparoscopy began to be utilized regularly in 1994. The selection of the second-look surgical approach depended on the surgeon's discretion. CO(2) pneumoperitoneum was utilized for all laparoscopic cases with the maximum intra-abdominal pressure maintained at 15 mm Hg. Patients received a variety of additional intravenous, intraperitoneal, or oral chemotherapy following positive second-look surgery.

RESULTS

Between 6/1/91 and 6/30/02, 289 patients were found to have persistent ovarian/peritoneal cancer at second look. Second-look operations included 131 (45%) transperitoneal laparoscopies and 139 (48%) laparotomies. Nineteen (7%) patients underwent laparoscopy followed immediately by laparotomy. The mean age, stage distribution, histology, grade, and size of residual disease at second look did not differ between the two groups. The median overall survival for patients who underwent laparoscopy, 41.1 months (95% CI, 33.2-58.1), did not significantly differ from that of the laparotomy group, 38.8 months (95% CI, 31.9-44.2) (P = 0.742).

CONCLUSIONS

Transperitoneal laparoscopy with CO(2) pneumoperitoneum does not appear to reduce the overall survival of women with persistent metastatic intra-abdominal carcinoma of ovarian/peritoneal origin. The overall survival appears to be independent of the second-look surgical approach.

Impact of dopamine and endothelin-1 antagonism on portal venous blood flow during laparoscopic surgery

BACKGROUND

Recent data indicate that pneumoperitoneal carbondioxide (CO2) insufflation impairs hepatic macro- and microcirculation. Whether dopamine and endothelin-1 (ET-1) antagonists might restore liver blood during laparoscopic surgery has not yet been investigated.

METHODS

For this study, 30 male WAG/Rij rats were randomized into two groups to obtain pneumoperitoneum with CO2 (n=15) or helium (n = 15). All the animals were implanted with a polyethylene-50 cannula into the right vena jugularis and a Doppler ultrasound flow probe around the portal vein. In each group, the rats were administered dopamine (n = 5); JKC-10, JKC-301, which is a selective endothelin-1 (ET-1) antagonist (n = 5), or sodium chloride as a control (n = 5). Portal blood flow was measured during intraabdominal pressures 2 to 12 mmHg. Data were analyzed using the Kruskal-Wallis h-test.

RESULTS

The application of dopamine and ET-1 antagonists significantly improved portal blood flow over that of the control animals (p <0.05). No significant differences were found between CO2 and helium insufflation (P > 0.05).

CONCLUSIONS

Dopamine and ET-1 antagonism restore portal blood flow during laparoscopic surgery independently of the insufflation gas. Whether improved hepatic perfusion might have beneficial effects on liver function needs further investigation.