Laparoscopic insufflation with room air causes exaggerated interleukin-6 response

Background: The gut is a central organ in the postoperative stress reaction. We previously reported that measuring gut-mucosal cytokines may more accurately reflect the response to operative stress. Additionally, we have shown that the gut demonstrates a blunted cytokine response after laparoscopy as compared with laparotomy. Methods: To further investigate whether this differential response is caused by exposure of the peritoneal cavity to general atmospheric air during laparotomy, 80 A/J mice were randomized equally into four groups: CD (carbon dioxide [CO₂] pneumoperitoneum), RA (room air pneumoperitoneum), AP (anesthesia and port insertion only), and PC (pure control, no intervention). Pneumoperitoneum was established and maintained at 3 mmHg for 60 min. All the mice were killed 4 h after the intervention. Jejunal mucosa and serum samples were collected and analyzed for interleukin-6 (IL-6) levels. Results were analyzed by analysis of variance (ANOVA). Results: Gut-mucosal IL-6 in the RA group was significantly higher than in all other groups: RA, 1,354.5 ± 117.9* vs. CD, 964.3 ± 114.0 vs. AP, 960.2 ± 86.2 vs. PC, 908.0 ± 83.6; *p < 0.05. The CD group did not show a significant increase in gut-mucosal IL-6 as compared with the AP and PC groups. Similarly, RA resulted in significant increases in serum IL-6 as compared with AP and PC, whereas CD showed no significant difference: RA, 161.3 ± 66.2* vs. 95.1 ± 1 vs. AP, 10.6 ± 5.3 vs. PC, undetectable; *p < 0.05. There was no difference in serum IL-6 level between CD or any of the other groups. Conclusions: Exposure of the peritoneal cavity to atmospheric air, independently of the trauma of abdominal access, causes an exaggerated serum and gut mucosal IL-6 response 4 h after intervention. The beneficial effect of CO₂ laparoscopy may be caused by the exclusion of general atmospheric air from the peritoneal cavity. Received: 29 June 1998/Accepted: 1 November 1998     

Increased tumor growth and spread after laparoscopy vs laparotomy

Background: The use of laparoscopy for assessment and treatment of malignant tumors remains controversial. The aim of this study was to evaluate the impact of tumor manipulation during laparoscopy compared with that of conventional laparotomy on growth and spread of an intraperitoneal tumor in the rat in a randomized, controlled trial. Methods: Thirty 2-month-old male Lewis rats received a single-site intrapancreatic inoculation of a ductal adenocarcinoma. Fourteen days after cancer implanting, two groups of six animals each underwent a laparotomy (30 min 6 mmHg CO₂ pneumoperitoneum). The tumor was manipulated in the one group, and exclusively visualized in the other. In two other groups, a midline laparotomy with (n = 6) or without (n = 6) tumor manipulation was performed. Animals in the control group (n = 6) underwent no procedure. Tumor volume, tumor mass, local regional invasion incidence, lymph node involvement, and liver and lung metastases were evaluated on 28-day tumors. Results: No difference in tumor growth and spread was observed between laparoscopy and laparotomy when tumor manipulation was not carried out. Tumor manipulation increased tumor growth significantly in the laparotomy group, but not in the laparoscopy one. Tumor metastases were correlated to tumor growth and increased significantly after manipulation in both groups. There was no port-site or conventional wound seeding in either the surgical procedure. Conclusions: This study showed that manipulation is the main factor acting on tumor dissemination in both laparoscopy and laparotomy. Laparoscopic surgery had a beneficial effect on local tumor growth compared with laparotomy in the case of tumor manipulation. This beneficial effect of laparoscopic surgery may be related to a better preservation of immune function in the early postoperative period. Received: 16 August 1996/Accepted: 27 January 1997     

Laparoscopic surgery and Kupffer cell activation

Background: Evidence tends to support a relative preservation of the systemic immune response with laparoscopy as compared with laparotomy. However, the role of hepatic macrophages, or Kupffer cells, in modulating this immune advantage is unknown. This study investigated the functions of Kupffer cells after either laparoscopy or laparotomy in a rat model. Methods: Rats underwent laparoscopy, laparotomy, or control operations. Kupffer cells were harvested, cultured, and stimulated with lipopolysaccharide. Culture supernatants were analyzed for tumor necrosis factor (TNF-α) and interleukin-6 (IL-6). Cytoplasmic lysates were analyzed for activation of two mitogen-activated protein kinases (MAPKs). Results: Production of TNF-α and IL-6 was similar in laparoscopy, laparotomy, and control groups. Both laparotomy and laparoscopy showed increased activation of p38 MAPK as compared with controls. Activation of ERK1/2 was decreased during laparotomy as compared with laparoscopy. Conclusions: Although cytokine production was similar in the laparoscopy and laparotomy groups, changes in MAPK activation suggest that intracellular pathways are more affected during laparotomy than during laparoscopy. Received: 1 April 1999/Accepted: 18 August 1999/Online publication: 26 July 2000     

Peritoneal response to a septic challenge

Background: Laparoscopic surgery has a lower incidence of surgical infection than open surgery. Differential factors that may modify the bacterial biology and explain this finding to some extent include CO₂ atmosphere, less desiccation of intraabdominal structures, fewer temperature changes, and a better preserved peritoneal and systemic immune response. Previous data suggest that the immune response and acute phase response are better preserved after laparoscopy. Therefore, we designed a study to evaluate the early peritoneal response to sepsis in an experimental peritonitis model comparing open surgery with CO₂ and abdominal wall lift laparoscopy. Methods: The study subjects comprised 360 mice distributed into the following four groups: group 1, n= 72 (controls); group 2, n= 96 (open surgery), 2–3 cm laparotomy, with abdominal cavity exposed to the air for 30 min; group 3, n= 96, CO₂ laparoscopy (5 mmHg pneumoperitoneum) for 30 min; group 4, n= 96, wall lift laparoscopy for 30 min. Intraabdominal contamination in the four groups was induced with 1 ml of E. coli suspension (1 × 10⁴ CFU/ml) 10 min before abdomen closure. Peritoneal fluid and blood samples were obtained 1.5, 3, 24, and 72 h after surgery, and TNF, IL-1, and IL-6 were measured (via ELISA), as well as quantitative culture. Results: The number of CFU (colony-forming units) obtained in peritoneal fluid and positive blood culture rates were significantly lower in the laparoscopic groups than in the open group. IL-1 peritoneal levels were significantly lower after 24 h and 72 h in the laparoscopy groups. IL-6 levels decreased sharply in the laparoscopy groups at 24 h and 72 h. There were no differences between the two types of laparoscopy models (CO₂ and wall lift). Conclusions: Peritoneal response to sepsis is better preserved after laparoscopy than after open surgery. CO₂ does not seem to influence bacterial growth. According to these findings, laparoscopy entails less local trauma and better preserved intraabdominal conditions. Received: 29 June 1998/Accepted: 25 August 1998     

Does laparoscopy increase bacteremia and endotoxemia in a peritonitis model?

Background: Laparoscopy is increasingly used in patients with intraabdominal bacterial infection although pneumoperitoneum may increase bacteremia by elevated intraabdominal pressure. Methods: The influence of laparotomy and laparoscopy on bacteremia, endotoxemia, and postoperative abscess formation was investigated in a rat model. Rats received intraperitoneally a standardized fecal inoculum and underwent laparotomy (n= 20), or laparoscopy (n= 20), or no further manipulation in the control group (n= 20). Results: Bacteremia and endotoxemia were higher after laparotomy and laparoscopy compared to the control group (p= 0.01) 1 h after intervention. One hour after intervention, aerobic and anaerobic bacterial species were detected in the laparotomy group while only anaerobic bacteria were found in the other two groups. Although bacteremia and endotoxemia did not differ among the three groups after 1 week, the mean number of intraperitoneal abscesses was significantly higher (p < 0.05) after laparotomy (n= 10) compared with laparoscopy (n= 6) and control group (n= 5). Conclusion: Laparoscopy does not increase bacteremia and intraperitoneal abscess formation compared to laparotomy in an animal model of peritonitis. Received: 28 May 1996/Accepted: 25 July 1996     

Effect of surgical stress on endogenous morphine and cytokine levels in the plasma after laparoscopoic or open cholecystectomy

Background: Endogenous morphine in the brain leads to various biological responses after surgery. The aim of this study was to determine whether morphine levels in the plasma would be enhanced by open laparotomy rather than by laparoscopic procedures. Methods: We compared 19 patients who underwent laparoscopic cholecystectomy with five patients who underwent resection of the gallbladder by open laparotomy. Morphine levels in the plasma were measured by an electrochemical detection system. Results: Postoperative endogenous morphine levels were higher with open laparotomy than with the laparoscopic technique (three h after surgery: open, 200 ± 52.6 fmol/ml vs laparoscopy, 17.6 ± 3.7, p < 0.01). This morphine elevation accounted for higher levels of cytokine, greater pain scores, and longer duration of fasting in open laparotomized patients than in laparoscopic cholecystectomy patients. Stress hormone levels in the plasma were also higher with open laparotomy than with laparoscopy. Conclusion: Morphine synthesis was enhanced by open laparotomy, resulting in greater biological response postoperatively than that seen with laparoscopic cholecystectomy. Received: 21 October 1998/Accepted: 3 April 1999     

Increased tumor establishment and growth after open vs laparoscopic bowel resection in mice

Background: Surgery can suppress immune function and facilitate tumor growth. Several studies have demonstrated better preservation of immune function following laparoscopic procedures. Our laboratory has also shown that tumors are more easily established and grow larger after sham laparotomy than after pneumoperitoneum in mice. The purpose of this study was to determine if the previously reported differences in tumor establishment and growth would persist in the setting of an intraabdominal manipulation. Methods: Syngeneic mice received intradermal injections of tumor cells and underwent either an open or laparoscopic cecal resection. In study 1, the incidence of tumor development was observed after a low dose inoculum; whereas in study 2, tumor mass was compared on postoperative day 12 after a high-dose inoculum. Results: In study 1, tumors were established in 5% of control mice, 30% of laparoscopy mice, and 83% of open surgery mice (p < 0.01 for all comparisons). In study 2, open surgery group tumors were 1.5 times as large as laparoscopy group tumors (p < 0.01), which were 1.5 times as large as control group tumors (p < 0.02). Conclusion: We conclude that tumors are more easily established and grow larger after open laparoscopic bowel resection in mice. Received: 27 October 1997/Accepted: 19 January 1998     

Laparoscopic vs conventional bowel resection in the rat

Background: The role of laparoscopic surgery in the treatment of colorectal disease is still controversial. To assess the metabolic consequences of laparoscopic and open bowel surgery, we studied serum levels of insulin-like growth factor 1 (IGF-1), an anabolic and mitogeneic peptide, in rats. Materials and methods: In experiment 1, the serum IGF-1 levels of 10 rats undergoing laparoscopic small bowel resections (group I) and 10 rats undergoing conventional small bowel resections (group II) were determined before surgery and on days 1, 2, and 7. Experiment 2 compared five rats that had CO₂ pneumoperitoneum (group III), five rats that underwent laparotomy (group IV), and five rats that received anesthesia only (group V). Differences in IGF-1 levels were tested with analysis of covariance. Results: In experiment 1, preoperative IGF-1 levels were similar in groups I and II (87.9 ± 6.1 nmol/L versus 90.5 ± 8.1 nmol/L). One day after surgery IGF-1 was 54.6 ± 10.5 in group I versus 41.6 ± 8.3 in group II (p= 0.006). Two days after surgery, IGF-1 was 79.4 ± 9.2 in group I versus 59.0 ± 10.5 in group II (p < 0.001). Seven days after both types of surgery, IGF-1 levels had returned to almost normal levels. In experiment 2, no significant differences were found between the rats with CO₂ pneumoperitoneum (group III) and those with laparotomy only (group IV). Rats that had anaesthesia only showed a significant decrease in IGF-1 levels between days 0 and 1 (p < 0.018). Conclusion: Our study indicates that laparoscopic bowel surgery is associated with a better postoperative anabolic state (i.e., less catabolism) than conventional surgery. This finding reflects a potential benefit of laparoscopy in bowel surgery. Received: 22 May 1996/Accepted: 10 July 1997     

The influence of laparotomy and laparoscopy on tumor growth in a rat model

Background: The effects of laparotomy and laparoscopy with different gases on subcutaneous and intraperitoneal tumor growth have not been evaluated yet. Methods: Tumor growth of colon adenocarcinoma DHD/K12/TRb was measured in rats after laparotomy, laparoscopy with CO₂ or air, and in control group. Cell kinetics were determined after incubation with carbon dioxide or air in vitro and tumor growth was measured subcutaneously and intraperitoneally after surgery in vivo. Results: In vitro, tumor cell growth increased significantly after incubation with air and CO₂. In vivo, intraperitoneal tumor weight was increased after laparotomy (1,203 ± 780 mg) and after laparoscopy with air (1,085 ± 891 mg) and with CO₂ (718 ± 690 mg) compared to control group (521 ± 221 mg) (p < 0.05). Subcutaneous tumor growth was promoted after laparotomy (71 ± 35 mg) and even more after laparoscopy with air (82 ± 45 mg) and CO₂ (99 ± 55 mg) compared to control group (36 ± 33 mg). Conclusions: Insufflation of air and CO₂ promote tumor growth in vitro. In vivo, intraperitoneal tumor growth seems to be promoted primarily by intraperitoneal air and subcutaneous tumor growth by CO₂. Received: 7 November 1996/Accepted: 3 December 1996     

Morbidity in laparoscopic gynecological surgery

Background: We set out to investigate prospectively the morbidity rate for gynecological laparoscopy patients at a tertiary care center. Methods: We prospectively recorded data on 743 laparoscopic procedures performed between January 1, 1992 and December 31, 1996. The procedures included 36 diagnostic laparoscopies (4.8%), 115 laparoscopies carried out for minor surgical acts (15.4%), 523 for major surgical acts (70.4%), and 69 for advanced surgical acts (9.4%). A total of 127 patients had a history of prior laparotomy (17%). All those procedures were performed by young senior surgeons. We defined a complication as an event that had modified the usual course of the procedure or of the postoperative period. For statistical analysis, we used the chi-squared test or Fisher's exact test. Results: Complications occurred in 22 cases; the overall complication rate was 2.9% when all events were considered. One complication (injury of the left primitive iliac artery) was related to insertion of the Veress needle (0.13%). A total of 2,578 trocars were inserted, giving rise to 10 complications (1.3%). Three unintended laparotomies were required for bowel or bladder injuries (0.4%). Finally, the introduction of the laparoscope was responsible for 11 complications (1.4%); this figure represents 50% of all the complications of this series. Eight intraoperative complications (1%) occurred during the laparoscopic surgery (seven severe bleedings and one ureter injury, but no intestinal lesions); laparotomy was required in six of these cases. Three complications occurred during the postoperative stage: one granulomatous peritonitis after intraabdominal rupture of a dermoid cyst, one incisional hernia, and a fast-resolving cardiac arrhythmia. Conclusions: In our experience, operative gynecological laparoscopy is associated with an acceptable morbidity rate. Moreover, about half of the complications occur during the installation of the laparoscopic procedure, underscoring the usefulness of safety rules. Received: 25 November 1997/Accepted: 8 May 1998     

Laparoscopic management of mechanical small bowel obstruction

Background: Laparoscopy is used increasingly for the management of acute abdominal conditions. For many years, previous abdominal surgery and intestinal obstruction have been regarded as contraindications to laparoscopy because there is an increased risk of iatrogenic bowel perforation. The role of laparoscopy in acute small bowel obstruction remains unclear. Methods: Since 1995, data from patients undergoing laparoscopic surgery have been entered prospectively into a database. Patients who underwent surgery before 1995 were added retrospectively to the same database. The charts of all patients treated surgically for mechanical small bowel obstruction were reviewed. Univariate analysis was performed to identify factors associated with success or failure, especially intraoperative complications, conversion, and postoperative morbidity. Stepwise logistic regression was used to assess for independent variables. Results: This study included 83 patients (56 women and 27 men) with a mean age of 56 years (range, 17–91 years). Conversion was necessary in 36 cases (43%). Laparoscopy alone was successful in 47 patients (57%). Intraoperative complications were noted in 16% and postoperative complications in 31% of the patients. Eight reoperations (9%) were necessary. Mortality was 2.4%. Duration of surgery (p < 0.001) and a bowel diameter exceeding 4 cm (p= 0.02) were predictors of conversion. No risk factor for intraoperative complication was identified. Accidental bowel perforation (p= 0.008) and the need for conversion (p= 0.009) were the only independent factors associated with an increased risk of postoperative complications. Conclusions: Laparoscopic management of small bowel obstruction is possible in roughly 60% of the patients selected for this approach. Morbidity is lower, resumption of a normal diet is faster, and hospital stay is shorter than with patients requiring conversion. No clear predictor of success or failure was identified, but intraoperative complications must be avoided. If the surgeon is widely experienced in advanced laparoscopic surgery and there is a liberal conversion policy, laparoscopy is a valuable alternative to conventional surgery in the management of acute small bowel obstruction. Received: 20 July 1999/Accepted: 22 November 1999/Online publication: 17 April 2000     

The efficacy of laparoscopic surgery in the diagnosis and treatment of peritonitis

Background: Peritonitis continues to be an important cause of morbidity and mortality and often an etiologic diagnosis is unclear. To evaluate the efficacy and safety of laparoscopy the authors analyzed their 5-year experience with this modality of treatment. Methods: A review was made of 107 consecutive nonselected laparoscopic procedures performed between October 1990 and November 1995. The diagnosis was established by clinical, laboratory, and imaging findings and confirmed by laparoscopy and/or laparotomy. Results: An etiologic diagnosis was unclear in 35% of the cases and was established in all by laparoscopy; 94 patients (87.9%) were successfully treated by laparoscopy while 13 (12.1%) required conversion. Mortality was 4.6%; 14% had postoperative complications and 7.4% had reoperations. Conclusions: Laparoscopic surgery is safe and very efficient in the diagnosis and treatment of patients with peritonitis. In most instances a definitive treatment can be carried out without conversion and has the additional and well-known advantages of minimally invasive surgery. Received: 15 March 1996/Accepted: 29 August 1996     

The role of laparoscopy in the diagnosis and treatment of abdominal pain syndromes

Background: Diagnostic laparoscopy plays a significant role in the evaluation of acute and chronic abdominal pain in the era of therapeutic laparoscopic surgery. Methods: We referred to our personal series of laparoscopy for both acute and chronic abdominal pain. This is a retrospective review of data accumulated prospectively between 1979 and the present. Results: In our series, 387 consecutive patients underwent laparoscopy because of abdominal pain. In a group of 121 patients with acute abdominal pain, a definitive diagnosis was made in 119 cases (98%). Two patients needed laparotomy to confirm the diagnosis; both had a disease process that did not require laparotomy to treat. A definitive therapeutic laparoscopic procedure was performed in 53 cases 944%). In 45 patients (38%), a diagnosis was made that did not require therapeutic laparoscopy or laparotomy to treat. In the remaining 21 patients (17.5%), exploratory laparotomy was needed to treat the condition. In a chronic abdominal pain group of 265 patients, the etiology was established laparoscopically in 201 cases (76%). A definitive therapeutic laparoscopic procedure was performed in 128 patients (48%). There was a normal laparoscopic examination in 64 patients (24%). There was one false negative laparoscopy that required laparotomy to treat 1 month later. Conclusions: Laparoscopy is an accurate modality for the diagnosis of both acute and chronic abdominal pain syndromes. These data support the use of laparoscopy as the primary invasive intervention in patients with acute and chronic abdominal pain. Received: 24 March 1997/Accepted: 4 September 1997     

Small bowel obstruction

Background: This is a retrospective review of our experience using a laparoscopic approach in the treatment of acute and chronic small bowel obstruction (SBO). Materials and methods: Of 136 patients hospitalized in our institutions for acute (94 cases: 69.1%) and chronic (42 cases: 30.8%) SBO, from January 1994 to March 1998, 63 (46.3%) were approached laparoscopically. The etiology was accurately diagnosed in 58 cases (92%), and it was possible to treat it laparoscopically in 82.5% (52 of 63 cases). In the remaining 11 cases (17.4%), a formal laparotomy was needed for bowel resection, due to an ischemic small bowel or for malignant disease. Results: Overall, 82.5% of our cases were successfully treated laparoscopically. Conclusions: We conclude that, in experienced hands, laparoscopy is an excellent diagnostic and, in the majority of cases, a therapeutic surgical approach in selected patients with acute or chronic SBO. Received: 30 June 1998/Accepted: 12 February 1999     

Effects of laparoscopic vs laparotomy treatment of E. coli peritonitis on hemodynamic responses in a porcine model

Background: Laparoscopic surgery is being used now for increasingly diverse clinical applications, including diagnosis and treatment of appendicitis and bacterial peritonitis. However, some concerns and controversies exist regarding the effectiveness of laparoscopic irrigation of the abdominal cavity compared with that achieved during laparotomy. Of no less importance is concern that establishing a CO₂ pneumoperitoneum in patients with cardiopulmonary insufficiency or endotoxemic shock may compromise hemodynamic function. The objective of this randomized, controlled study was to determine the effects of laparoscopic versus laparotomy intervention on hemodynamic and outcome measurements using a porcine model of Escherichia coli peritonitis. Methods: For this study, 24 specific pathogen-free Hanford pigs underwent surgical placement of carotid, Swan-Ganz, and peritoneal catheters. After a 24-h recovery period, one subset of pigs (n= 12) received a bolus infusion of 9 × 10⁸ CFU/kg E. coli intraperitoneally (septic) and intravenous fluid resuscitation. The remaining 12 pigs were not challenged with E. coli (control). Twenty-four hours later, all 24 pigs underwent either laparoscopic or open peritoneal irrigation with saline, then were reevaluated 48 h after surgical intervention. Standard cardiopulmonary, hematologic, and bacteriologic assessments were obtained both perioperatively and 48 h after surgical intervention. Results: Pigs given E. coli exhibited significantly elevated heart rates and core temperatures and decreased O₂ saturation during the initial 6 h. Within 24 h, these pigs exhibited respiratory alkalosis, altered blood leukocyte profiles, and E. coli–infected peritoneal fluid. Random blood samples from the septic pigs tested negative for E. coli. Mean pulmonary artery and capillary wedge pressures were lower (p < 0.05) in septic than in control pigs before and after surgical intervention. Septic pigs that underwent laparoscopy had significantly lower (p < 0.05) arterial pH and higher arterial pCO₂ levels than septic pigs after laparotomy. Other cardiopulmonary responses were similar irrespective of the surgical modality used. One of six septic pigs from each surgical group still had E. coli growth in its peritoneal fluid 48 h after surgical intervention. Conclusion: Laparoscopic intervention demonstrated effectiveness equal to that of laparotomy for treating acute E. coli peritonitis in pigs without septic shock. Received: 26 June 1998/Accepted: 12 January 1999     

Laparoscopic management of acute small-bowel obstruction

Background: A retrospective review is given of the authors' experience with a consecutive series of acute small-bowel obstruction unresponsive to medical management. Methods: There were 33 exploratory laparoscopies. The etiology was accurately diagnosed in 100% of the cases. Twenty-five (76%) were secondary to postoperative adhesions, of which 18 (72%) were successfully treated by laparoscopic lysis of adhesions. Minilaparotomy was needed to treat iatrogenic perforation (two), gangrenous bowel (one), and Meckel's diverticulectomy (one). Formal laparotomy was utilized for small-bowel resection (two), malignant adhesions (two), and intolerance of pneumoperitoneum (one). Four cases of incarcerated hernias were treated by conventional herniorrhaphy. Results: Overall, 67% of our cases were spared formal laparotomy. Conclusion: We conclude that laparoscopy is an excellent diagnostic modality in acute small-bowel obstruction, the majority of which can be simultaneously managed laparoscopically. Laparotomy should be reserved for malignant adhesions, surgical misadventure, or when the pathology dictates. Received: 4 March 1996/Accepted: 13 May 1996     

Transperitoneal laparoscopic pelvic lymphadenectomy for gynecologic malignancies (II)

Background: We reviewed the published experimental and clinical data, available in MEDLINE, and compared them with our own experience, in a university-affiliated tertiary medical center of obstetrics and gynecology in order to report on the accepted indications for laparoscopic pelvic lymphadenectomy. Methods: Surgical staging of cervical carcinoma can be performed via the laparoscopic approach. Intraperitoneal biopsies, washings, and pelvic lymphadenectomy can also be carried out with high accuracy and limited morbidity. Node-negative women are better treated by a radical hysterectomy performed either simultaneously (using frozen sections) or secondarily after routine pathologic examination of the pelvic nodes. Node-positive patients have a poor prognosis, no matter what the treatment is, and are generally considered for radiotherapy and/or chemotherapy. The use of laparoscopic pelvic lymphadenectomy in advanced cervical cancers is limited. Results: Laparoscopy has a direct therapeutic application in endometrial carcinoma. Total hysterectomy, bilateral salpingo-oophorectomy, and pelvic lymphadenectomy can all be performed via laparoscopy. Thus, stage I and some stage II endometrial cancers can be treated exclusively laparoscopically. This approach seems as effective as laparotomy, but it dramatically reduces the costs and morbidity associated with conventional treatment. Conclusions: Currently, the use of laparoscopy in ovarian and tubal cancers is confined to referral centers. Laparoscopy appears to be as effective as laparotomy for second-look surgery. Treatment of stage II and more advanced ovarian cancers has been reported, but it cannot be recommended in a routine situation. Received: 3 February 1997/Accepted: 18 July 1997     

Laparoscopic surgery preserves monocyte-mediated tumor cell killing in contrast to the conventional approach

Background: Experimental animal research shows that immunologic defenses against tumor cells are disturbed by surgical trauma, resulting in an increased rate of tumor implantation and the growth of subsequent metastases. Minimally invasive surgery is associated with a preservation of postoperative immunologic functions and, in animal models, with decreased tumor growth. The objective was to study the influence of several surgical procedures, approached conventionally and laparoscopically, on interleukin-6 (IL-6) and monocyte-mediated cytotoxicity (MMC). Methods: Five groups of five patients each were included in this prospective study: laparoscopic cholecystectomy (minor trauma) group, Nissen fundoplication (laparoscopic and conventional as moderate trauma) groups, and sigmoid colectomy (laparoscopic and conventional as major trauma) groups. Preoperatively, 1 and 4 days after surgery, IL-6 and MMC against SW948 colon cancer cell line were determined. Results: The IL-6 levels differed significantly between the three laparoscopic procedures (p= 0.004) and increased according to the degree of trauma. There was no significant difference in MMC between the three laparoscopic procedures. However, MMC was suppressed after conventional procedures and preserved after laparoscopic procedures (p= 0.001). There was no correlation between IL-6 levels and changes in MMC. Conclusions: More extensive laparoscopic procedures induce increased levels of IL-6, reflecting higher levels of trauma. Conventional surgical procedures result in depressed MMC in the postoperative period. After laparoscopic procedures, MMC is preserved. These findings may be of importance in preventing implantation and growth of cancer cells spread by surgical manipulation. Received: 10 December 1998/Accepted: 25 March 1999     

Diagnostic laparoscopy in patients with an acute abdomen of uncertain etiology

Background: There are acute abdominal conditions in which it is difficult to establish an indicative diagnosis before laparotomy. A diagnosis is important in planning the right abdominal incision or to avoid an unnecessary laparotomy. Diagnostic noninvasive procedures such as X-ray studies do not always appear conclusive. Diagnostic laparoscopy is the only technique which can visualize the abdomen and, by establishing an adequate diagnosis, permits the surgeon to plan the right abdominal approach. Methods: In a prospective study, 65 patients with a generalized acute abdomen (no intestinal obstruction or perforation) underwent a diagnostic laparoscopy under general anesthesia previous to the planned median laparotomy. Results: In 46 patients (70%) diagnostic laparoscopy permitted the establishment of an adequate diagnosis, whereas in seven patients (10%) no cause for the acute abdomen could be found and an explorative laparotomy was avoided. In another 12 patients (20%) insufficient information was obtained during laparoscopy and an explorative laparotomy was performed. Conclusions: A conclusive diagnosis was established in 53 patients. This information led to a change in the surgical approach in 38 patients (e.g., limited, well-placed approach, laparoscopically, or avoidance of an unnecessary laparotomy). Diagnostic laparoscopy in this category of patients is a useful technique with important therapeutic consequences. Received: 5 May 1997/Accepted: 18 September 1997     

Hormone-cytokine response

Background: Changes in blood hormone and cytokine were investigated in patients who underwent laparoscopic cholecystectomy via insufflation (CO₂ group) vs those who had abdominal wall-lifting (Air group). Methods: Seventeen female patients with cholecystolithiasis were randomly divided into two groups. Peripheral blood samples were obtained during perioperative period, and plasma hormone levels (ACTH, cortisol) and serum cytokine levels (TNFα, IL-1β, IL-6, IL-10) were measured. Results: The number of circulating lymphocytes significantly decreased at 1 h after surgery in both groups, but the decrease in the CO₂ group was significantly smaller than that in the Air group. There was no significant difference in hormone elevation between groups. Serum concentrations of IL-6 and IL-10 in the Air group were significantly higher than in the CO₂ group. Conclusions: CO₂ insufflation may reduce cytokine production in laparoscopic cholecystectomy. Received: 10 November 1996/Accepted: 19 February 1997