Ventilatory and blood gas changes during laparoscopic and open cholecystectomy

Effects of CO2 pneumoperitoneum on proliferation, apoptosis, and migration of gastrointestinal stromal tumor cells

BACKGROUND

The purpose of the study was to investigate the proliferation and migration capability of human gastrointestinal stromal tumor line GIST-T1 after exposure to different pressures and times of CO₂ pneumoperitoneum.

METHODS

We established simulated CO₂ pneumoperitoneum environment in vitro and divided the human GIST cell GIST-T1 into open control group, 8 mmHg CO₂ pneumoperitoneum treatment group and 15 mmHg CO₂ pneumoperitoneum treatment group. Each group was divided into two subgroups respectively cultured for 1 h and 3 h. pH value of cell culture, cell growth curve, and cell cycle distribution of each group was measured. By application of scratch healing tests and Transwell chamber experiments, mobility ratio and number of cells through 8 µm membranes were measured to assess the migration ability of cells in each group after intervention.

RESULTS

Cell culture pH value of each subgroup in CO₂ group decreased significantly after exposed in CO₂ pneumoperitoneum (P < 0.01). The proliferation of GIST-T1 cells in 15 mmHg CO₂ group was significantly inhibited early (1-2 days) (P < 0.05) and the proliferation of GIST-T1 cells in 8 mmHg CO₂ 1 h subgroup and 15 mmHg CO₂ 1 h subgroup was increased significantly late (4-6 days) (P < 0.05) after the interventions of CO₂ pneumoperitoneum. The percentage of cells in G0-G1 phase increased, the percentage of S phase cells decreased (P < 0.01) in 1-h subgroup and 3-h subgroup of 15 mmHg CO₂ group 24 h after exposure to CO₂. The percentage of cells in S phase increased in 1-h subgroup of 8 mmHg CO₂ group and decreased in 3-h subgroup of 15 mmHg CO₂ group 72 h after exposure to CO₂. In the Transwell chamber experiment, the cell number through 8-µm membrane increased significantly (P < 0.01) in 3-h subgroup of CO₂ group compared to that in 3-h subgroup of control group.

CONCLUSIONS

The routine pressure and duration of CO₂ pneumoperitoneum used in clinic did not promote the proliferation of gastrointestinal stromal tumors, but had a potential risk of increasing postoperative recurrence and distant metastasis.

Laparoscopic assisted versus open gastric pull-up following thoracoscopic esophagectomy: A cohort study

BACKGROUND

Thoracolaparoscopic esophagectomy (TLE) is a type of minimally invasive esophagectomy (MIE) for esophageal cancer which consists of thoracoscopic resection and laparoscopic reconstruction. The aim of the present study was to evaluate the technical and oncological feasibility of alimentary tract reconstruction with laparoscopically assisted gastric pull-up (LAG) following thoracoscopic esophagectomy in the prone position (TSEP) in comparison with reconstruction with open laparotomy gastric pull-up (OLG) following TSEP, to establish TLE with extended lymph node dissection as a standard operation for esophageal cancer.

METHODS

Sixty-four patients with esophageal cancer underwent TSEP with 3-field lymphadenectomy from 2008 through 2010: for reconstruction after TSEP, 31 patients underwent LAG, and 33 patients underwent OLG. We retrospectively evaluated the technical and oncological feasibility of TLE with 3-field lymphadenectomy and compared surgical outcomes after reconstruction with OLG and that with LAG.

RESULTS

TLE with 3-field lymphadenectomy was successfully completed in 30 of 31 (97%) patients, and no surgery-related postoperative deaths occurred. No significant difference was found between LAG and OLG in the mean number of dissected abdominal lymph nodes, amount of blood loss, incidence of postoperative complications, mean postoperative hospital stay, restoration rate of respiratory function, or rate of complete resection or locoregional control, but the mean duration of abdominal procedures was significantly longer with LAG than with OLG.

CONCLUSION

This study demonstrates that the quality and safety of surgery and the oncological effectiveness of LAG for esophageal cancer. TLE consisting of LAG following TSEP with extended lymph-node dissection is a feasible surgical technique for thoracic esophageal carcinoma.

Comparative changes in tissue oxygenation between laparoscopic and open cholecystectomy

Background

Previous studies examined the effect of laparoscopic cholecystectomy (LC) versus open cholecystectomy (OC) on physiological variables of the respiratory system. In this study we compared changes in arterial blood gases-related parameters between LC and OC to assess their comparative influence on gas exchange.

Methods

We studied 28 patients, operated under identical anesthetic protocol (LC: 18 patients, OC: 10 patients). Measurements were made on the morning before surgery (BS), the second (AS2) and the eighth (AS8) postoperative day. Studied parameters, including alveolar-arterial difference in PO₂ ((A-a)DO₂) and oxygen content (Oct in vol%), were statistically compared.

Results

On AS2 a greater increase was found in ((A-a)DO₂) for the OC compared to LC (4.673 ± 0.966 kPa versus 3.773 ± 1.357 kPa, respectively). Between BS and AS2, Oct in vol% decreased from 17.55 ± 1.90 to 15.69 ± 1.88 in the LC and from 16.99 ± 2.37 to 14.62 ± 2.23 in the OC, whilst a reduction (P = 0.093) between AS2 and AS8 was also found for the open method. Besides, on AS2, SaO₂% decrease was greater in OC compared to LC (P = 0.096).

Conclusions

On AS2, the greater increase in OC-((A-a)DO₂) associated with Oct in vol% and SaO₂% findings also in OC group suggest that LC might be associated with lower risk for impaired tissue oxygenation.

Effects of laparoscopic cholecystectomy on lung function: A systematic review

AIM: To present and integrate findings of studies investigating the effects of laparoscopic cholecystectomy on various aspects of lung function.

METHODS: We extensively reviewed literature of the past 24 years concerning the effects of laparoscopic cholecystectomy in comparison to the open procedure on many aspects of lung function including spirometric values, arterial blood gases, respiratory muscle performance and aspects of breathing control, by critically analyzing physiopathologic interpretations and clinically important conclusions. A total of thirty-four articles were used to extract information for the meta-analysis concerning the impact of the laparoscopic procedure on lung function and respiratory physiopathology. The quality of the literature reviewed was evaluated by the number of their citations and the total impact factor of the corresponding journals. A fixed and random effect meta-analysis was used to estimate the pooled standardized mean difference of studied parameters for laparoscopic (LC) and open (OC) procedures. A crude comparison of the two methods using all available information was performed testing the postoperative values expressed as percentages of the preoperative ones using the Mann-Whitney two-sample test.

RESULTS: Most of the relevant studies have investigated and compared changes in spirometric parameters.The median percentage and interquartile range (IQR) of preoperative values in forced vital capacity (FVC), forced expiratory volume in 1 s and forced expiratory flow (FEF) at 25%-75% of FVC (FEF_25%-75%) expressed as percentage of their preoperative values 24 h after LC and OC were respectively as follows: [77.6 (73.0, 80.0) L vs 55.4 (50.0, 64.0) L, P < 0.001; 76.0 (72.3, 81.0) L vs 52.5 (50.0, 56.7) L, P < 0.001; and 78.8 (68.8, 80.9) L/s vs 60.0 (36.1, 66.1) L/s, P = 0.005]. Concerning arterial blood gases, partial pressure of oxygen [PaO₂ (kPa)] at 24 or 48 h after surgical treatment showed reductions that were significantly greater in OC compared with LC [LC median 1.0, IQR (0.6, 1.3); OC median 2.4, IQR (1.2, 2.6), P = 0.019]. Fewer studies have investigated the effect of LC on respiratory muscle performance showing less impact of this surgical method on maximal respiratory pressures (P < 0.01); and changes in the control of breathing after LC evidenced by increase in mean inspiratory impedance (P < 0.001) and minimal reduction of duty cycle (P = 0.01) compared with preoperative data.

CONCLUSION: Laparoscopic cholecystectomy seems to be associated with less postoperative derangement of lung function compared to the open procedure.

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.

Laparoscopic versus open gastrectomy for early distal gastric cancer: a meta-analysis

BACKGROUND

We performed a meta-analysis in an attempt to answer whether short-term outcomes and lymph nodes harvested after laparoscopy-assisted gastrectomy (LAG) are comparable to those reported after conventional open gastrectomy (COG).

METHODS

Prospective randomized clinical trials were eligible if they included patients with distal gastric cancer treated by LAG versus COG. End points were operating time, intra-operative blood loss, size of wound, overall post-operative complications, time to first flatus, time to start oral intake, hospital stay and lymph nodes harvested.

RESULTS

Six trials including 668 patients were included. For four of the 13 end points, the summary point estimates favoured LAG over COG; there was a significant reduction in intra-operative blood loss (weighted mean difference (WMD) −115.60, 95% confidence interval (CI) −159.16 to −72.04, P < 0.00001), size of wound (WMD −5.27, 95% CI −8.94 to −1.60, P= 0.005), overall post-operative complications (odds ratio 0.55, 95% CI 0.35 to 0.85, P = 0.008) and hospital stay (WMD −2.65, 95% CI −4.97 to −0.32, P= 0.03) for LAG. However, the combined results of the individual trials show significant longer operating time (WMD 112.98, 95% CI 60.32 to 165.64, P < 0.0001) and significant reduction in lymph nodes harvested (WMD −4.79, 95% CI −6.79 to −2.79, P < 0.00001) in the LAG group. There was no significant difference between the two groups in time to first flatus, time to start oral intake, wound infection, intra-abdominal fluid collection and abscess, anastomotic stenosis and leakage and pulmonary complications.

CONCLUSION

The results of this meta-analysis suggest that LAG for early distal cancer is a feasible and safe alternative to COG, with better short-term outcomes.

Two clinically relevant pressures of carbon dioxide pneumoperitoneum cause hepatic injury in a rabbit model

AIM: To observe the hepatic injury induced by carbon dioxide pneumoperitoneum (CDP) in rabbits, compare the effects of low- and high-pressure pneumoperitoneum, and to determine the degree of hepatic injury induced by these two clinically relevant CDP pressures.

METHODS: Thirty healthy male New Zealand rabbits weighing 3.0 to 3.5 kg were randomly divided into three groups (n = 10 for each group) and subjected to the following to CDP pressures: no gas control, 10 mmHg, or 15 mmHg. Histological changes in liver tissues were observed with hematoxylin and eosin staining and transmission electron microscopy. Liver function was evaluated using an automatic biochemical analyzer. Adenine nucleotide translocator (ANT) activity in liver tissue was detected with the atractyloside-inhibitor stop technique. Bax and Bcl-2 expression levels were detected by western blotting.

RESULTS: Liver functions in the 10 mmHg and 15 mmHg experimental groups were significantly disturbed compared with the control group. After CDP, the levels of alanine transaminase and aspartate transaminase were 77.3 ± 14.5 IU/L and 60.1 ± 11.4 IU/L, respectively, in the 10 mmHg experimental group and 165.1 ± 19.4 IU/L and 103.8 ± 12.3 IU/L, respectively, in the 15 mmHg experimental group, which were all higher than those of the control group (P < 0.05). There was no difference in pre-albumin concentration between the 10 mmHg experimental group and the control group, but the pre-albumin level of the 15 mmHg experimental group was significantly lower than that of the control group (P < 0.05). No significant differences were observed in the levels of total bilirubin or albumin among the three groups. After 30 and 60 min of CDP, pH was reduced (P < 0.05) and PaCO₂ was elevated (P < 0.05) in the 10 mmHg group compared with controls, and these changes were more pronounced in the 15 mmHg group. Hematoxylin and eosin staining showed no significant change in liver morphology, except for mild hyperemia in the two experimental groups. Transmission electron microscopy showed mild mitochondrial swelling in hepatocytes of the 10 mmHg group, and this was more pronounced in the 15 mmHg group. No significant difference in ANT levels was found between the control and 10 mmHg groups. However, ANT concentration was significantly lower in the 15 mmHg group compared with the control group. The expression of hepatic Bax was significantly increased in the two experimental groups compared with the controls, but there were no differences in Bcl-2 levels among the three groups. Twelve hours after CDP induction, the expression of hepatic Bax was more significant in the 15 mmHg group than in the 10 mmHg group.

CONCLUSION: A CDP pressure of 15 mmHg caused more substantial hepatic injury, such as increased levels of acidosis, mitochondrial damage, and apoptosis; therefore, 10 mmHg CDP is preferable for laparoscopic operations.

Open, small-incision, or laparoscopic cholecystectomy for patients with symptomatic cholecystolithiasis. An overview of Cochrane Hepato-Biliary Group reviews

BACKGROUND

Patients with symptomatic cholecystolithiasis are treated by three different techniques of cholecystectomy: open, small-incision, or laparoscopic. There is no overview on Cochrane systematic reviews on these three interventions.

OBJECTIVES

To summarise Cochrane reviews that assess the effects of different techniques of cholecystectomy for patients with symptomatic cholecystolithiasis.

METHODS

The Cochrane Database of Systematic Reviews (CDSR) was searched for all systematic reviews evaluating any interventions for the treatment of symptomatic cholecystolithiasis (Issue 4 2008).

MAIN RESULTS

Three systematic reviews that included a total of 56 randomised trials with 5246 patients are included in this overview of reviews. All three reviews used identical inclusion criteria for trials and participants, and identical methodological assessments.Laparoscopic versus small-incision cholecystectomy Thirteen trials with 2337 patients randomised studied this comparison. Bias risk was relatively low. There was no significant difference regarding mortality or complications. Total complications of laparoscopic and small-incision cholecystectomy were high, ie, 17.0% and 17.5%. Total complications (risk difference, random-effects model -0.01 (95% confidence interval (CI) -0.07 to 0.05)), hospital stay (mean difference (MD), random-effects -0.72 days (95% CI -1.48 to 0.04)), and convalescence were not significantly different. Trials with low risk of bias showed a quicker operative time for small-incision cholecystectomy (MD, low risk of bias considering 'blinding', random-effects model 16.4 minutes (95% CI 8.9 to 23.8)) while trials with high risk of bias showed no statistically significant difference.Laparoscopic versus open cholecystectomy Thirty-eight trials with 2338 patients randomised studied this comparison. Bias risk was high. Laparoscopic cholecystectomy patients had a shorter hospital stay (MD, random-effects model -3 days (95% CI -3.9 to -2.3)) and convalescence (MD, random-effects model -22.5 days (95% CI -36.9 to -8.1)) compared with open cholecystectomy but did not differ significantly regarding mortality, complications, and operative time.Small-incision versus open cholecystectomy Seven trials with 571 patients randomised studied this comparison. Bias risk was high. Small-incision cholecystectomy had a shorter hospital stay (MD, random-effects model -2.8 days (95% CI -4.9 to -0.6)) compared with open cholecystectomy but did not differ significantly regarding complications and operative time.

AUTHORS' CONCLUSIONS

No statistically significant differences in the outcome measures of mortality and complications have been found among open, small-incision, and laparoscopic cholecystectomy. There were no data on symptom relief. Complications in elective cholecystectomy are high. The quicker recovery of both laparoscopic and small-incision cholecystectomy patients compared with patients on open cholecystectomy justifies the existing preferences for both minimal invasive techniques over open cholecystectomy. Laparoscopic and small-incision cholecystectomies seem to be comparable, but the latter has a significantly shorter operative time, and seems to be less costly.

A prospective randomized, controlled study comparing low pressure versus high pressure pneumoperitoneum during laparoscopic cholecystectomy

BACKGROUND

The increase in intra-abdominal pressure by insufflation of carbon dioxide during laparoscopy brings certain changes in function of organ systems and also leads to postoperative pain. Degree of intra-abdominal pressure is directly related with such change. Laparoscopic cholecystectomy can be performed at low pressure pneumoperitoneum. However, available space for dissection is less than the high pressure pneumoperitoneum.

METHODS

Twenty-six patients for elective laparoscopic cholecystectomy were studied in a prospective, randomized, patient, and surgeon blinded manner. The intra-abdominal pressure was kept either in low pressure (8 mm Hg) or in high pressure (12 mm Hg). All patients underwent two dimensional echocardiography, pulmonary function test and color Doppler examination of lower limb vessels preoperatively and postoperatively. Arterial blood gas analysis and End Tidal CO2 monitored before insufflation, during surgery and after deflation. Pain score was measured by visual analog scale and surgeon's comfort level was recorded. Postoperative analgesia requirement, complications, and hospital stay were recorded. Student t test used for the statistical analysis.

RESULTS

Both groups match for the demographic parameters. Four patients required conversion to high pressure. Intraoperative pO2 level, postoperative pain, analgesic requirement, pulmonary function, and hospital stay were favoring low pressure pneumoperitoneum in a statistically significant manner. There was no difference between 2 groups for duration of surgery, intraoperative, and postoperative complications. However, the technical difficulties were graded more (statistically nonsignificant) with low pressure pneumoperitoneum.

CONCLUSIONS

An uncomplicated gall stone disease can be treated by low pressure laparoscopic cholecystectomy with reasonable safety by an experienced surgeon. Though surgeons experience more difficulty in dissection during low pressure pneumoperitoneum, it is significantly advantageous in terms of postoperative pain, use of analgesics, preservation of pulmonary function, and hospital stay.

Systematic review: open, small-incision or laparoscopic cholecystectomy for symptomatic cholecystolithiasis

BACKGROUND

Laparoscopic cholecystectomy has become the method of choice for gallbladder removal, although evidence of superiority over open and small-incision cholecystectomy is lacking.

AIM

To compare the effects of open, small-incision and laparoscopic cholecystectomy techniques for patients with symptomatic cholecystolithiasis.

METHODS

We conducted updated searches until January 2007 in multiple databases. We assessed bias risk.

RESULTS

Fifty-nine trials randomized 5556 patients. No significant differences in primary outcomes (mortality and complications) were found among all three techniques. Both minimal invasive techniques show advantages over open cholecystectomy in terms of convalescence. Small-incision cholecystectomy showed shorter operative time compared with laparoscopic cholecystectomy (random effects, weighted mean difference, 16.4 min; 95% confidence interval, 8.9-23.8), but the two techniques did not differ regarding hospital stay and conversions.

CONCLUSIONS

No significant differences in mortality and complications were found among all three techniques. Laparoscopic cholecystectomy and small-incision cholecystectomy are preferred over open cholecystectomy for quicker convalescence. Laparoscopic cholecystectomy and small-incision cholecystectomy show no clear differences on patient outcomes.

Factors affecting 13C-natural abundance measurement of breath carbon dioxide during surgery: absorption of carbon dioxide during endoscopic procedures

The aim of this paper is to review the factors which may affect breath (13)CO(2)/(12)CO(2) natural abundance in patients undergoing surgery or intensive care. Intravenous glucose administration is a major determinant of the (13)CO(2)/(12)CO(2) of breath as intravenous glucose preparations are almost all derived from cornstarch. In addition, the oxidation of endogenous substrates can affect the (13)CO(2)/(12)CO(2) ratio. During many endoscopic procedures, such as laparoscopic surgery, carbon dioxide insufflation is used to provide a working space. As medical CO(2) is relatively depleted in (13)CO(2) compared with endogenous and exogenous metabolic CO(2) sources, breath (13)CO(2)/(12)CO(2) measurements can be used to estimate CO(2) absorption during these procedures. However, all these factors may also be affected by the bicarbonate pool, making a definitive attribution of changes in breath (13)CO(2)/(12)CO(2) to a single factor problematic.

Physiologic Responses to Infrarenal Aortic Cross-Clamping during Laparoscopic or Conventional Vascular Surgery in Experimental Animal Model: Comparative Study

The aim of this study was to compare the hemodynamic and ventilatory effects of prolonged infrarenal aortic cross-clamping in pigs undergoing either laparotomy or laparoscopy. 18 pigs were used for this study. Infrarenal aortic crossclamping was performed for 60 minutes in groups I (laparotomy, n = 6) and II (laparoscopy, n = 6). Group III (laparoscopy, n = 6) underwent a 120-minute long pneumoperitoneum in absence of aortic clamping (sham group). Ventilatory and hemodynamic parameters and renal function were serially determined in all groups. A significant decrease in pH and significant increase in PaCO₂ were observed in group II, whereas no changes in these parameters were seen in group I and III. All variables returned to values similar to baseline in groups I and II 60 minutes after declamping. A significant increase in renal resistive index was evidenced during laparoscopy, with significantly higher values seen in Group II. Thus a synergic effect of pneumoperitoneum and aortic cross-clamping was seen in this study. These two factors together cause decreased renal perfusion and acidosis, thus negatively affecting the patient's general state during this type of surgery.

Laparoscopic vs. small incision cholecystectomy: Implications for pulmonary function and pain. A randomized clinical trial

BACKGROUND

Upper abdominal surgery, including laparoscopic cholecystectomy (LC), is associated with post-operative pulmonary dysfunction. LC has, by consensus, become the treatment of choice for symptomatic cholecystolithiasis. The small-incision cholecystectomy (SIC), a procedure which does not require a pneumoperitoneum threatens to be lost to clinical practice even though there is evidence of equality. We hypothesized that the SIC technique should be equal and might even be superior to the LC when considering post-operative pulmonary function due to the short incision length.

METHODS

A single-centre, randomized clinical trial was performed including patients scheduled for elective cholecystectomy. Pulmonary flow-volume curves were measured pre-operatively, post-operatively, and at follow up. Blood gas analyses were measured pre-operative, in the recovery phase and on post-operative day 1. Anaesthesia, analgesics, and peri-operative care were standardized by protocol. Post-operatively, patients and caregivers were blinded to the procedure.

RESULTS

A total of 257 patients were analysed. There was one pulmonary complication (pneumonia) in the LC group. In both groups, similar reductions of approximately 20% in pulmonary function parameters occurred, with complete recovery to pre-operative values. Patients in the SIC group consumed more analgesia when compared with the LC group without impact on blood gas analysis. Patients converted to a conventional open technique showed significant differences in six of the eight parameters in pulmonary function tests.

CONCLUSION

When evaluated with strict methodology and standardization of care, no clinically relevant differences were found between SIC and LC regarding pulmonary function. Our results suggest that the popularity of the laparoscopic technique cannot be attributed to pulmonary preservation.

Anaesthesiological considerations in small-incision and laparoscopic cholecystectomy in symptomatic cholecystolithiasis: implications for pulmonary function. A randomized clinical trial

BACKGROUND

Upper abdominal surgery, including laparoscopic cholecystectomy (LC), is associated with post-operative pulmonary dysfunction. LC has, by consensus, become the treatment of choice for symptomatic cholecystolithiasis. Small-incision cholecystectomy (SIC), a procedure that does not require a pneumoperitoneum, threatens to be lost to clinical practice, even though there is evidence of equality. We hypothesized that the SIC technique should be equal, and might even be superior, to LC when considering post-operative pulmonary function because of the short incision length.

METHODS

A single-centre randomized clinical trial was performed including patients scheduled for elective cholecystectomy. Pulmonary flow-volume curves were measured pre-operatively, post-operatively and at follow-up. Blood gas analyses were measured pre-operatively, in the recovery phase and on post-operative day 1. Anaesthesia, analgesics and peri-operative care were standardized by protocol. Post-operatively, patients and caregivers were blind to the procedure.

RESULTS

Two hundred and fifty-seven patients were analysed. There was one pulmonary complication (pneumonia) in the LC group. In both groups, similar reductions of approximately 20% in pulmonary function parameters occurred, with complete recovery to pre-operative values. Patients in the SIC group consumed more analgesia when compared with the LC group, without any impact on blood gas analysis. Patients converted to a conventional open technique showed significant differences in six of the eight parameters in pulmonary function tests.

CONCLUSION

When evaluated with strict methodology and standardization of care, no clinically relevant differences were found between SIC and LC with regard to pulmonary function. Our results suggest that the popularity of the laparoscopic technique cannot be attributed to pulmonary preservation.

Bariatric surgery primer for the internist: keys to the surgical consultation

The increasing prevalence of morbid obesity in North America combined with the refinement of laparoscopic techniques for the performing these operations has contributed to the exponential growth of bariatric surgery over the last 10 years. There are many important considerations for the internist who is referring a patient for bariatric surgery.

Laparoscopic versus open cholecystectomy for patients with symptomatic cholecystolithiasis

BACKGROUND

Cholecystectomy is one of the most frequently performed operations. Open cholecystectomy has been the gold standard for over 100 years. Laparoscopic cholecystectomy was introduced in the 1980s.

OBJECTIVES

To compare the beneficial and harmful effects of laparoscopic versus open cholecystectomy for patients with symptomatic cholecystolithiasis.

SEARCH STRATEGY

We searched TheCochrane Hepato-Biliary Group Controlled Trials Register (April 2004), The Cochrane Library (Issue 1, 2004), MEDLINE (1966 to January 2004), EMBASE (1980 to January 2004), Web of Science (1988 to January 2004), and CINAHL (1982 to January 2004) for randomised trials.

SELECTION CRITERIA

All published and unpublished randomised trials in patients with symptomatic cholecystolithiasis comparing any kind of laparoscopic cholecystectomy versus any kind of open cholecystectomy. No language limitations were applied.

DATA COLLECTION AND ANALYSIS

Two authors independently performed selection of trials and data extraction. The methodological quality of the generation of the allocation sequence, allocation concealment, blinding, and follow-up was evaluated to assess bias risk. Analyses were based on the intention-to-treat principle. Authors were requested additional information in case of missing data. Sensitivity and subgroup analyses were performed when appropriate.

MAIN RESULTS

Thirty-eight trials randomised 2338 patients. Most of the trials had high bias risk. There was no significant difference regarding mortality (risk difference 0,00, 95% confidence interval (CI) -0.01 to 0.01). Meta-analysis of all trials suggests less overall complications in the laparoscopic group, but the high-quality trials show no significant difference ('allocation concealment' high-quality trials risk difference, random effects -0.01, 95% CI -0.05 to 0.02). Laparoscopic cholecystectomy patients have a shorter hospital stay (weighted mean difference (WMD), random effects -3 days, 95% CI -3.9 to -2.3) and convalescence (WMD, random effects -22.5 days, 95% CI -36.9 to -8.1) compared to open cholecystectomy.

AUTHORS' CONCLUSIONS

No significant differences were observed in mortality, complications and operative time between laparoscopic and open cholecystectomy. Laparoscopic cholecystectomy is associated with a significantly shorter hospital stay and a quicker convalescence compared with the classical open cholecystectomy. These results confirm the existing preference for the laparoscopic cholecystectomy over open cholecystectomy.

Small-incision versus open cholecystectomy for patients with symptomatic cholecystolithiasis

BACKGROUND

Cholecystectomy is one of the most frequently performed operations. Open cholecystectomy has been the gold standard for over 100 years. Small-incision cholecystectomy is a less frequently used alternative.

OBJECTIVES

To compare the beneficial and harmful effects of small-incision versus open cholecystectomy for patients with symptomatic cholecystolithiasis.

SEARCH STRATEGY

We searched TheCochrane Hepato-Biliary Group Controlled Trials Register (6 April 2004), The Cochrane Library (Issue 1, 2004), MEDLINE (1966 to January 2004), EMBASE (1980 to January 2004), Web of Science (1988 to January 2004), and CINAHL (1982 to January 2004) for randomised trials.

SELECTION CRITERIA

All published and unpublished randomised trials in patients with symptomatic cholecystolithiasis comparing any kind of small-incision or other kind of minimal incision cholecystectomy versus any kind of open cholecystectomy. No language limitations were applied.

DATA COLLECTION AND ANALYSIS

Two authors independently performed selection of trials and data extraction. The methodological quality of the generation of the allocation sequence, allocation concealment, blinding, and follow-up was evaluated to assess bias risk. Analyses were based on the intention-to-treat principle. Authors were requested additional information in case of missing data. Sensitivity and subgroup analyses were performed if appropriate.

MAIN RESULTS

Seven trials randomised 571 patients. Bias risk was high in the included trials. No mortality was reported. The total complication proportions are respectively 9.9% and 9.3% in the small-incision and open group, which is not significantly different (risk difference all trials, random-effects 0.00, 95% confidence interval (CI) -0.06 to 0.07). There are also no significant differences considering severe complications and bile duct injuries. However, small-incision cholecystectomy has a shorter hospital stay (weighted mean difference, random-effects -2.8 days (95% CI -4.9 to -0.6)) compared to open cholecystectomy.

AUTHORS' CONCLUSIONS

Small-incision and open cholecystectomy seem to be equivalent regarding risks of complications, but the latter method is associated with a significantly longer hospital stay. The quicker recovery of small-incision cholecystectomy compared with open cholecystectomy confirms the existing preference of this technique over open cholecystectomy.

Laparoscopic versus small-incision cholecystectomy for patients with symptomatic cholecystolithiasis

BACKGROUND

Cholecystectomy is one of the most frequently performed operations. Open cholecystectomy has been the gold standard for over 100 years. Small-incision cholecystectomy is a less frequently used alternative. Laparoscopic cholecystectomy was introduced in the 1980s.

OBJECTIVES

To compare the beneficial and harmful effects of laparoscopic versus small-incision cholecystectomy for patients with symptomatic cholecystolithiasis.

SEARCH STRATEGY

We searched TheCochrane Hepato-Biliary Group Controlled Trials Register (6 April 2004), The Cochrane Library (Issue 1, 2004), MEDLINE (1966 to January 2004), EMBASE (1980 to January 2004), Web of Science (1988 to January 2004), and CINAHL (1982 to January 2004) for randomised trials.

SELECTION CRITERIA

All published and unpublished randomised trials in patients with symptomatic cholecystolithiasis comparing any kind of laparoscopic cholecystectomy versus small-incision or other kind of minimal incision open cholecystectomy. No language limitations were applied.

DATA COLLECTION AND ANALYSIS

Two authors independently performed selection of trials and data extraction. The methodological quality of the generation of the allocation sequence, allocation concealment, blinding, and follow-up was evaluated to assess bias risk. Analyses were based on the intention-to-treat principle. Authors were requested additional information in case of missing data. Sensitivity and subgroup analyses were performed if appropriate.

MAIN RESULTS

Thirteen trials randomised 2337 patients. Methodological quality was relatively high considering the four quality criteria. Total complications of laparoscopic and small-incision cholecystectomy are high: 26.6% versus 22.9%. Total complications (risk difference, random-effects -0.01, 95% confidence interval (CI) -0.07 to 0.05), hospital stay (weighted mean difference (WMD), random-effects -0.72 days, 95% CI -1.48 to 0.04), and convalescence were not significantly different. High-quality trials show a quicker operative time for small-incision cholecystectomy (WMD, high-quality trials 'blinding', random-effects 16.4 minutes, 95% CI 8.9 to 23.8) while low-quality trials show no significant difference.

AUTHORS' CONCLUSIONS

Laparoscopic and small-incision cholecystectomy seem to be equivalent. No differences could be observed in mortality, complications, and postoperative recovery. Small-incision cholecystectomy has a significantly shorter operative time. Complications in elective cholecystectomy are prevalent.

Absorption of carbon dioxide during laparoscopy in children measured using a novel mass spectrometric technique

BACKGROUND

Carbon dioxide (CO(2)) is absorbed during pneumoperitoneum and may cause adverse haemodynamic effects. The aim of this study was to measure the elimination of exogenous CO(2) during laparoscopy in children.

METHODS

Ten children [27.6 (56.5) months; mean (SD)] undergoing laparoscopic and nine [24.5 (17.3) months] undergoing open surgery were studied. Breath samples were collected at the line for end-tidal CO(2) and analysed for (13)CO(2)/(12)CO(2) ratio expressed as deltaPDB (difference from standard), by isotope-ratio mass spectrometry. The proportion of absorbed CO(2) was calculated comparing exhaled (13)CO(2)/(12)CO(2) before and during CO(2) pneumoperitoneum.

RESULTS

(13)CO(2)/(12)CO(2) in medical CO(2) was -32.7 (2.1) deltaPDB. (13)CO(2)/(12)CO(2) in breath of patients undergoing open procedures was -24.3 (2.4) deltaPDB at the start of operation and did not change during the operation (P > 0.2). (13)CO(2)/(12)CO(2) in breath of patients undergoing laparoscopy was -21.5 (5.4) deltaPDB at the start of insufflation, and decreased during pneumoperitoneum by 2.5 (1.6) deltaPDB, indicating absorption of exogenous CO(2). The percentage of expired CO(2) absorbed rose to 15.5 (7.7)% after 30 min of pneumoperitoneum and decreased rapidly after desufflation.

CONCLUSION

After 10 min of laparoscopy 10-20% of expired CO(2) derives from the exogenous CO(2). CO(2) absorption can be measured using a simple mass spectrometric technique.

CO2 promotes plasminogen activator inhibitor type 1 expression in human mesothelial cells

BACKGROUND

Previous observations have indicated that CO2 insufflation increases peritoneal plasminogen activator inhibitor type 1 (PAI-1) expression.

METHODS

Primarily cultured human peritoneal mesothelial cells were exposed to either flowing or pressurized CO2 for 90 min. Unexposed cultures served as controls. Samples of cell culture media were taken at 0, 5, and 24 h after exposure to measure media pH, PAI-1, and tissue-type plasminogen activator (t-PA) protein release. Simultaneous samples were taken to measure PAI-1 and t-PA mRNA expression.

RESULTS

Mesothelial cells exposed to flowing CO2 released more PAI-1 than those exposed to pressurized CO2 ( p < 0.001) and controls ( p < 0.001). Cells exposed to flowing CO2 had an increased PAI-1 mRNA expression at 5 h.

CONCLUSIONS

CO2 increased mesothelial cell PAI-1 expression involving a transcriptional mechanism. These findings might provide a mechanism for adhesion formation and cancer progression following laparoscopic surgery.

Efeitos do pneumoperitônio com ar e CO2 na gasometria de suínos

OBJETIVO: O pneumoperitônio produz várias alterações na fisiologia humana. Algumas destas alterações, como hipercapnia e acidose, dependem ou são agravadas com o uso de CO2, tendo maior repercussão em pacientes com problema cardio-respiratório. A necessidade de uma melhor alternativa para insuflação da cavidade; a observação de que as cirurgias abertas, assim como as laparoscópicas com suspensão mecânica, são realizadas na presença de Ar ambiente; e a escassez de trabalhos testando o Ar em substituição ao CO2 para insuflação da cavidade, foram motivos para a realização deste trabalho. MÉTODOS: Vinte (0) suínos anestesiados foram submetidos a pneumoperitônio com 1 hora de duração. Os animais foram distribuídos em 4 grupos de 5 animais: Grupo A1 - Pneumoperitônio de Ar a 10 mmHg; Grupo A - Pneumoperitônio de Ar a 16 mmHg; Grupo B1 - Pneumoperitônio de CO2 a 10 mmHg; Grupo B - Pneumoperitônio de CO2 a 16 mmHg. O pneumoperitônio foi realizado pela técnica aberta com trocater de Hasson. Através de um cateter venoso central colhe-se amostra de sangue para exame de gasometria em 3 momentos. RESULTADOS: A análise da gasometria venosa não revelou alterações significativas entre os grupos em relação a PaO2 e a saturação do O2. Nos Grupos A1, A e B1 não foram observadas alterações no equilíbrio ácido-básico. No Grupo B após uma hora de pneumoperitônio houve nítida tendência a hipercapnia e acidose. CONCLUSÃO: O ar, com a técnica aberta de pneumoperitônio foi uma opção segura para insuflação de cavidade em procedimentos laparoscópicos diagnósticos de suínos.

Randomized comparison between different insufflation pressures for laparoscopic cholecystectomy

Laparoscopy using carbon dioxide insufflation induces adverse effects in both the cardiovascular and the respiratory function. The use of low pressure pneumoperitoneum has been shown to reduce adverse hemodynamic effects. However, its effect on tissue trauma and postoperative pain and recovery remains controversial. The aim of this study was to compare tissue trauma, postoperative pain, and recovery in two groups of patients undergoing laparoscopic cholecystectomy, one at insufflation pressure of 8 (LC8) and the other at 15 mm Hg (LC15). Forty patients were randomized, 20 in each group. The characteristics of the patients were similar in the two groups. The procedure was completed in all patients in the LC15 group, but in 2 patients in the LC8 group the pressure was increased to 15 mm Hg to complete the operation. There were no significant differences in postoperative pain scores, analgesic consumption, and the incidence of nausea, vomiting, and shoulder pain between the two groups. C-reactive protein concentrations and white blood cell count rose significantly after surgery, but the increase was similar in the two groups. The median duration of surgery was similar, 23 minutes (range 15-65) in the LC8 group and 25 minutes (range 15-80) in the LC15 group. Using our technique of laparoscopic cholecystectomy, there were no advantages to tissue damage, postoperative pain, and recovery when a low pressure pneumoperitoneum was used.

Correlação entre as pressões parciais de co2 no ar expirado e no sangue arterial, em porcas submetidas a pneumoperitônio

OBJETIVO: As cirurgias realizadas por via laparoscópica, que utilizam CO2 para realização do pneumoperitônio, cursam com hipercarbia. Esta alteração pode ser estimada pela pressão parcial de CO2 no ar expirado. Este trabalho foi realizado com a finalidade de determinar se há correlação entre pressão parcial de CO2 arterial e pressão parcial de CO2 no ar expirado nas cirurgias por via laparoscópica. MÉTODO: Distribuíram-se 20 porcas em dois grupos: sem pneumoperitônio e com pneumoperitônio de 12 mmHg de pressão intra-abdominal. Foram medidas a pressão endotraqueal, saturação arterial de O2, pressão parcial de CO2 no ar expirado, pH e pressão parcial de CO2 arteriais. RESULTADOS: Após a realização do pneumoperitônio foi encontrado aumento significativo da pressão endotraqueal, da pressão parcial de CO2 no ar expirado e pressão parcial de CO2 arterial. CONCLUSÕES: Apesar de ter ocorrido aumento nas pressões parciais de CO2 tanto arterial quanto no ar expirado, não houve correlação linear entre elas, não se podendo estimar em cirurgias por via laparoscópica a pressão parcial de CO2 arterial pela pressão parcial de CO2 no ar expirado.

Carbon dioxide elimination during laparoscopy in children is age dependent

The absorption of carbon dioxide (CO2) used for positive pressure pneumoperitoneum may lead to an increased CO2 load. CO2 elimination during laparoscopy has not been investigated previously in paediatrics. The aim of this study was to characterise the pattern of CO2 elimination during laparoscopic surgery in infants and children.

METHODS

Twenty children undergoing laparoscopy and 19 children undergoing laparotomy for elective abdominal operations were studied. Pneumoperitoneum was achieved using insufflation of unheated CO2. CO2 elimination (metabolically produced + absorbed; milliliters per kilogram per minute) was measured minute by minute during the operation by indirect calorimetry. End-tidal CO2 (kPa) was recorded every 10 minutes. The above variables were assessed before CO2 insufflation, during pneumoperitoneum, and after desufflation.

RESULTS

Before insufflation, CO2 elimination was 4.6 +/- 0.3 ml/kg/min and increased after 15 minutes of pneumoperitoneum to 5.2 +/- 0.3 (P <.001). Post desufflation, CO2 elimination decreased toward preinsufflation values, but did not return to baseline by the end of operation (5.8 +/- 0.3; P <.001). End-tidal CO2 was 4.7 +/- 0.2 preinsufflation, peaked at 1 hour (5.3 +/- 0.2; P <.001) and subsequently decreased in response to ventilatory adjustments. The total amount of CO2 insufflated was positively correlated with patient age (r2 = 0.27; P <.01). CO2 elimination was age related, as indicated by multilevel model analysis and by negative correlations between maximum increase in CO2 elimination and both age (r2 = 0.27; P <.01) and weight (r2 = 0.29; P <.01). These data suggest that the younger or smaller the child, the larger the increase in CO2 elimination. Seven patients (35%) responded to desufflation with a sharp transient increase in CO2 elimination, which did not appear to be related to patient age, length of pneumoperitoneum, abdominal pressure, or type of operation.

CONCLUSIONS

During pneumoperitoneum, younger children absorb proportionately more CO2 than older individuals. The short-lived increase in CO2 elimination postdesufflation may be related to an increase in venous return from the lower limbs after release of the abdominal pressure. These findings suggest that small children warrant close monitoring during laparoscopy and during the immediate postoperative period.

Randomized comparison of conventional carbon dioxide insufflation and abdominal wall lifting for laparoscopic cholecystectomy

BACKGROUND

Gasless laparoscopy using abdominal wall lifting (AWL) has been developed in an attempt to avoid the adverse effects of carbon dioxide pneumoperitoneum that may occur in conventional laparoscopy. However, lifting has been criticized for its poor operative space and surgical invasiveness. This study compared the AWL method with conventional CO2 pneumoperitoneum for laparoscopic cholecystectomy with respect to operation performance, postoperative course, and stress response.

PATIENTS AND METHODS

During a 6-month period, 95 patients with symptomatic gallstones were randomly assigned to receive laparoscopic cholecystectomy with conventional CO2 pneumoperitoneum (CO2 group; N = 47) or the AWL method (AWL group; N = 48). Operative results and operative time were recorded. Cardiopulmonary functions were assessed, and arterial blood gases were analyzed during surgery. Urinary cortisol, vanillylmandelic acid, metanephrines, and nitrogen loss; serum complement 3, C-reactive protein, and interleukin-6; postoperative pain; and the presence of nausea and vomiting were assessed for 48 hours after surgery. Postoperative time to recovery of flatus, tolerance of a full oral diet, and full activity were also determined.

RESULTS

Only three significant differences were found. First, intraoperative ventilatory function deteriorated significantly less in the AWL group. Second, arterial blood gas determinations and capnography showed a greater decrease in intraoperative arterial pH and compliance with CO2 retention and an increase in peak airway pressure in the CO2 group (P < 0.05), reflecting poorer ventilatory performance. Third, preparation time and total operating time were significantly greater with the AWL method (P < 0.05).

CONCLUSIONS

Although AWL required a longer operation time, our results suggest that the technique may still have value in high-risk patients with cardiorespiratory diseases.

A randomized controlled trial comparing open vs laparoscopy-assisted distal gastrectomy for the treatment of early gastric cancer: an interim report

BACKGROUND

The application of laparoscopy-assisted distal gastrectomy (LADG) for early gastric cancer remains controversial among gastric surgeons. The purpose of this study was to compare LADG with open distal gastrectomy (ODG) regarding clinical outcome and postoperative parameters, including postoperative pain and pulmonary function.

METHODS

From October 1998 to March 2001, 28 patients with early gastric cancer were randomly assigned to an LADG (n = 14) or ODG group (n = 14) with Billroth I reconstruction. Postoperative pain during resting, coughing, and walking were evaluated by a visual analog scale (VAS). Pulmonary functions such as forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1) measured on the third postoperative day were compared with preoperative functions.

RESULTS

Patients in the 2 groups were comparable for age, gender, height, weight, staging, and location of gastric cancer. The mean blood loss was significantly less in the LADG than in the ODG group (P <.05). Histologic examinations of resected specimens revealed that these 2 operations were identical from the standpoint of curability. Patients in the LADG group recovered both bowel movement and walking ability earlier than did patients in the ODG group (P <.05). The postoperative VAS pain score during rest was lower for 3 days after LADG than ODG (P <.05) and for 1 day during coughing or walking (P <.05). The pulmonary functions such as FVC and FEV1 values were reduced on the third day after LADG and ODG. However, the FVC value on the third day after LADG was lower than after ODG (P <.05).

CONCLUSIONS

This study demonstrates that LADG has several advantages including an earlier recovery, less pain, and less impaired pulmonary function after gastric surgery when compared with ODG; furthermore, no reduction in curability was observed.

Prolonged anesthesia with desflurane and fentanyl in dogs during conventional and laparoscopic surgery

OBJECTIVE

To determine the effects of prolonged anesthesia with desflurane in dogs undergoing laparotomy or abdominal laparoscopy.

DESIGN

Randomized prospective study.

ANIMALS

20 adult mixed-breed dogs.

PROCEDURE

Dogs were randomly assigned to 1 of 2 groups with 10 dogs/group. Anesthesia was induced with propofol and maintained with desflurane and fentanyl, and pyloroplasty was performed. In 10 dogs, a ventral midline laparotomy was performed; in the other 10, abdominal laparoscopy was performed. Dogs were monitored for cardiovascular and respiratory responses (ECG, oxygen saturation [SpO2], arterial blood pressure, rectal temperature, end-tidal partial pressure of carbon dioxide [PETCO2], and expired desflurane concentration). Recovery times were recorded.

RESULTS

Mean +/- SD duration of anesthesia was 201 +/- 25 minutes for dogs undergoing laparotomy and 287 +/- 15 minutes for dogs undergoing laparoscopy. Anesthesia was accompanied by hypotension that was less severe in dogs undergoing laparoscopy. Heart rate did not vary significantly during anesthesia. The SpO2 was > 97% in all dogs at all times, and PETCO2 remained within reference limits. Recovery times for dogs that underwent laparotomy were not significantly different from those for dogs that underwent laparoscopy. Mean +/- SD time to standing was 13.6 +/- 2.4 minutes for dogs that underwent laparotomy and 12.5 +/- 2.9 minutes for dogs that underwent laparoscopy.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggest that induction of anesthesia with propofol and maintenance with desflurane and fentanyl is safe in dogs undergoing abdominal surgery.

Comparison of pulmonary function and postoperative pain after laparoscopic versus open gastric bypass: a randomized trial

BACKGROUND

Impairment of pulmonary function is common after upper abdominal operations. The purpose of this study was to compare postoperative pulmonary function and analgesic requirements in patients undergoing either laparoscopic or open Roux-en-Y gastric bypass (GBP).

STUDY DESIGN

Seventy patients with a body mass index of 40 to 60 kg/m2 were randomly assigned to undergo laparoscopic (n = 36) or open (n = 34) GBP. The two groups were similar in age, gender, body mass index, pulmonary history, and baseline pulmonary function. Pulmonary function studies were performed preoperatively and on postoperative days 1, 2, 3, and 7. Oxygen saturation and chest radiographs were performed on both groups preoperatively and on postoperative day 1. Postoperative pain was evaluated using a visual analog scale and the amount of narcotic consumed was recorded. Data are presented as mean +/- standard deviation.

RESULTS

Laparoscopic GBP patients had significantly less impairment of pulmonary function than open GBP patients on the first three postoperative days (p < 0.05). By the 7th postoperative day, all pulmonary function parameters in the laparoscopic GBP group had returned to within preoperative levels, but only one parameter (peak expiratory flow) had returned to preoperative levels in the open GBP group. On the first postoperative day, laparoscopic GBP patients used less morphine than open GBP patients (46 +/- 31 mg versus 76 +/- 39 mg, respectively, p < 0.001), and visual analog scale pain scores at rest and during mobilization were lower after laparoscopic GBP than after open GBP (p < 0.05). Fewer patients after laparoscopic GBP than after open GBP developed hypoxemia (31% versus 76%, p < 0.001) and segmental atelectasis (6% versus 55%, p = 0.003).

CONCLUSION

Laparoscopic gastric bypass resulted in less postoperative suppression of pulmonary function, decreased pain, improved oxygenation, and less atelectasis than open gastric bypass.

Laparoscopic colorectal cancer surgery

BACKGROUND

A number of controversies exist in the laparoscopic treatment of colorectal cancer, and thus the technique has so far failed to gain widespread acceptance throughout the United Kingdom. This review aims to discuss these issues in the context of ongoing published trials, assessing both purported advantages and disadvantages.

METHODS

The United States National Library of Medicine Medline database, and the Bath Information Data Service (BIDS) were searched using keywords related to laparoscopic colorectal cancer surgery. Recent surgical journals were also reviewed for relevant publications. Attempts have been made to quote only the most recent work from institutions with multiple publications using the same group of patients, in order to present the most coherent picture. The data are presented as randomized controlled trials, nonrandomized controlled studies, and series comprising more than 10 patients.

CONCLUSIONS

This review confirms that laparoscopic colorectal cancer surgery is technically feasible. In addition patients lose less blood, have less immunosuppression, and have shorter postoperative ileus, in-patient stay, and require less analgesia. However, concerns still remain as to the development of port-site metastases, the longer operating times, and the overall cost of the equipment. In view of these concerns, the place of laparoscopically assisted colorectal cancer surgery is likely to remain controversial for some years yet. Randomized, controlled trials are as yet too few to provide definitive answers to all these issues.

A case-control study of postoperative pulmonary complications after laparoscopic and open cholecystectomy

Postoperative pulmonary complications (PPC) are common after upper abdominal surgery. The objective of this case-control study was to compare the incidence of PPC after laparoscopic cholecystectomy (LC) and open cholecystectomy (OC) within a tertiary care center. Patients were accrued from two sequential clinical trials that evaluated the role of incentive spirometry in the prevention of PPC after abdominal surgery. Included for study were patients with gallstones undergoing elective surgery who had an American Society of Anesthesiologists (ASA) classification < 3. All patients included in the study were encouraged to use an incentive spirometer at least 10 times each hour while awake. Patients with chronic bronchitis were excluded from study, as were patients who received other forms of physical therapy. OC was performed through either a transverse or an oblique incision. There was an equitable dispersion of putative risk factors for PPC between the groups at baseline. PPC were defined as clinical features consistent with collapse/consolidation, an otherwise unexplained temperature above 38 degrees C, plus either confirmatory chest radiology or positive sputum microbiology. The incidence of PPC was 2.7% (1/37) after LC and 17.2% (10/58) after OC (p < 0.05). It is concluded that PPC are less common after laparoscopic cholecystectomy than after open cholecystectomy.

Does hypercarbia develop faster during laparoscopic herniorrhaphy than during laparoscopic cholecystectomy? Assessment with continuous blood gas monitoring

The use of CO2 to create and maintain a pneumoperitoneum during laparoscopic surgery may lead to hypercarbia and acidosis. CO2 is also insufflated into the preperitoneal space to create and maintain a pneumopreperitoneum for laparoscopic herniorrhaphy. This study examined the influence of CO2 pneumopreperitoneum on the development of hypercarbia and acidosis assessed with continuous intraarterial blood gas monitoring. Changes in blood gas values were measured with both continuous intraarterial and intermittent blood gas monitoring. Over a 4-mo period, blood gas values of 14 patients undergoing laparoscopic herniorrhaphy (pneumopreperitoneum) were compared with those of 13 patients undergoing laparoscopic cholecystectomy (pneumoperitoneum) in a tertiary referral center. Additionally, heart rate and blood pressure were measured during stable ventilation at constant insufflation pressure. Pneumopreperitoneum resulted in a significantly faster development of hypercarbia (P = 0.023) and acidosis (P = 0.027) than pneumoperitoneum. These results were not explained when corrected for changes in hemodynamic and ventilatory variables using analysis of covariance. We conclude that the more rapid development of hypercarbia and acidosis during pneumopreperitoneum can be explained by increased CO2 absorption through an increasing gas exchange area during the procedure and through a larger wound bed.

Laparoscopic groin hernia repair: results of 200 consecutive herniorraphies

Laparoscopic hernia surgery was introduced in this unit in May 1992. Up to September 1993, 175 patients with 200 inguinal and femoral hernias were treated using this approach. This prospective study deals with intraoperative and postoperative complications, patient recovery and early operative results. The median (range) age was 58 (21-87) years and the median (range) follow-up was 12 (5-24) months. A laparoscopic transabdominal preperitoneal technique was used. The median (range) operation time was 67 (23-160) min for unilateral hernias and the median (range) hospital stay was 1 (0-27) day. Major complications were two postoperative bowel obstructions and seven recurrences, six of these in the first 31 patients. Overall, 17 minor complications were recorded; 52 per cent of the patients were back at work within 1 week, and 94 per cent within 1 month. The value of laparoscopic hernia repair remains to be determined and randomized controlled trials will be necessary.

Helium pneumoperitoneum for laparoscopic cholecystectomy: ventilatory and blood gas changes

Laparoscopic cholecystectomy with carbon dioxide pneumoperitoneum may result in hypercarbia and acidosis in patients with cardiorespiratory disease. The aim of the present study was to assess helium as an alternative to carbon dioxide for creating the pneumoperitoneum. Ventilation requirements and carbon dioxide levels were assessed at the beginning and end of laparoscopic cholecystectomy using helium (n = 30) and carbon dioxide (n = 30) pneumoperitoneum. Insufflation with helium did not result in an increase in ventilation requirement although, like carbon dioxide pneumoperitoneum, it was associated with a mean rise in peak airway pressure (of 7 cmH2O; P < 0.001). There was also a 3.2-kPa increase in the alveolar-arterial oxygen gradient with helium (P = 0.006). Carbon dioxide pneumoperitoneum was associated with a significant rise in arterial carbon dioxide levels, despite increasing ventilation. Four patients with helium pneumoperitoneum had surgical emphysema for 5 days. Helium may be a suitable alternative to carbon dioxide for creating pneumoperitoneum in patients with severe cardiorespiratory disease. However, because of its low water solubility helium has a lower safety margin than carbon dioxide in the rare event of gas embolism.