Diss. (sammanfattning) Göteborg : Univ. , 2007. / Härtill 5 uppsatser.

Chu Xiangyang. / Thesis submitted in: December 1999. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves 130-148). / Abstracts in English and Chinese. / ABSTRACT --- p.i / ACKNOWLEDGMENTS --- p.v / ABBREVIATION --- p.vi / TABLE OF CONTENT --- p.viii / Chapter 1. --- Introduction / Chapter 1.1 --- General introduction --- p.1 / Chapter 1.2 --- History of laparoscopic surgery --- p.2 / Chapter 1.2.1 --- Diagnostic laparoscopy --- p.3 / Chapter 1.2.2 --- Operative laparoscopy --- p.5 / Chapter 1.2.3 --- Pediatric laparoscopy --- p.6 / Chapter 1.3 --- Pathophysiology of pneumoperitoneum --- p.8 / Chapter 1.3.1 --- Choice of gas for pneumoperitoneum --- p.9 / Chapter 1.3.2 --- C02 absorption and acid-base balance --- p.10 / Chapter 1.3.3 --- Effects of pneumoperitoneum on respiratory system --- p.16 / Chapter 1.3.4 --- Effects of pneumoperitoneum on circulatory system --- p.17 / Chapter 1.3.4.1 --- Due to hypercarbia --- p.18 / Chapter 1.3.4.2 --- Due to increased intraabdominal pressure (IAP) --- p.21 / Chapter 1.4 --- Pathophysiology of peritonitis --- p.26 / Chapter 1.4.1 --- Animal model of peritonitis --- p.26 / Chapter 1.4.2 --- Effects of peritonitis on cardiovascular system --- p.30 / Chapter 1.5 --- The purpose of this study --- p.33 / Chapter 2. --- Materials and Methods / Chapter 2.1 --- Animals and grouping --- p.34 / Chapter 2.2 --- Anaesthesia and procedures --- p.35 / Chapter 2.3 --- Pulmonary monitoring --- p.41 / Chapter 2.4 --- Hemodynamic monitoring --- p.42 / Chapter 2.4.1 --- Arterial catheter --- p.42 / Chapter 2.4.2 --- Pulmonary arterial catheter --- p.43 / Chapter 2.4.3 --- Cardiac output measurement --- p.44 / Chapter 2.5 --- Experimental design --- p.45 / Chapter 2.5.1 --- Operative intervention --- p.47 / Chapter 2.5.2 --- C02 pneumoperitoneum --- p.47 / Chapter 2.5.3 --- Data collection --- p.48 / Chapter 2.6 --- Blood gas analysis --- p.49 / Chapter 2.7 --- Oxygenation analysis --- p.50 / Chapter 2.8 --- Histological study --- p.51 / Chapter 2.9 --- Equations used for calculations --- p.54 / Chapter 2.10 --- Statistical analysis --- p.55 / Chapter 3. --- Results / Chapter 3.1 --- Baseline physiological measurements --- p.56 / Chapter 3.2 --- Acid-base balance measurements --- p.58 / Chapter 3.2.1 --- End tidal C02 tension (PetC02) --- p.58 / Chapter 3.2.2 --- Arterial partial pressure of C02 (PaC02) --- p.60 / Chapter 3.2.3 --- Arterial pH (pHa) --- p.62 / Chapter 3.2.4 --- Arterial bicarbonate (HC03a-) --- p.67 / Chapter 3.2.5 --- Arterial base excess (BEa) --- p.72 / Chapter 3.3 --- Hemodynamic measurements --- p.77 / Chapter 3.3.1 --- Mean arterial pressure (MAP) --- p.77 / Chapter 3.3.2 --- Central venous pressure (CVP) --- p.82 / Chapter 3.3.3 --- Mean pulmonary artery pressure (MPAP) --- p.84 / Chapter 3.3.4 --- Pulmonary artery wedge pressure (PAWP) --- p.86 / Chapter 3.3.5 --- Heart rate (HR) --- p.88 / Chapter 3.3.6 --- Cardiac index (CI) --- p.93 / Chapter 3.3.7 --- Stroke volume index (SVI) --- p.96 / Chapter 3.3.8 --- Systemic vascular resistance index (SVRI) --- p.98 / Chapter 3.3.9 --- Pulmonary vascular resistance index (PVRI) --- p.100 / Chapter 3.4 --- Respiratory and oxygenation measurements --- p.101 / Chapter 3.4.1 --- Peak inspiratory pressure (PIP) --- p.101 / Chapter 3.4.2 --- Arterial oxygen saturation (Sa02) --- p.105 / Chapter 3.4.3 --- Arterial oxygen content (Ca02) --- p.107 / Chapter 3.4.4 --- Oxygen delivery index (D02I) --- p.107 / Chapter 3.4.5 --- Oxygen consumption index (V02I) --- p.107 / Chapter 3.5 --- Pathology --- p.108 / Chapter 4. --- Discussion / Chapter 4.1 --- Effects on C02 homeostasis --- p.112 / Chapter 4.2 --- Effects on hemodynamics --- p.117 / Chapter 4.2 --- Effects on oxygenation --- p.123 / Chapter 4.3 --- Evaluation of the animal model --- p.124 / Chapter 5. --- Conclusion / Chapter 5.1 --- Conclusion --- p.127 / Chapter 5.2 --- Future prospective --- p.129 / BIBLIOGRAPHY --- p.130

by Angela Mara Bentes de Souza. / "June 2003." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (p. 176-200). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

Made available in DSpace on 2015-12-06T23:44:42Z (GMT). No. of bitstreams: 0 Previous issue date: 2006 / Objetivo: Estudar a fase inicial da cicatrização de uma sutura gástrica confeccionada com grampeador linear cortante, submetida ao aumento de pressão intra-abdominal por pneumoperitônio entre 12 e 14 mmHg, durante sessenta e cento e vinte minutos, comparando-as com a mesma sutura mantida sob pressão atmosférica Métodos: Utilizou-se 30 cães distribuídos em 3 grupos de 10 animais: Grupo I, denominado de controle (sutura gástrica linear cortante), Grupo II (sutura gástrica linear cortante) e aumento da pressão intra-abdominal logo após a sutura por 60 minutos e Grupo III (sutura linear cortante) e aumento da pressão intra–abdominal logo após a sutura por 120 minutos. Todos os cães foram mantidos sob anestesia geral por 120 minutos após a sutura comum aos 3 grupos. Decorridos 7 dias de pós– operatório, avaliou-se os parâmetros macroscópicos do estômago e microscópicos de fragmentos gástricos junto a linha de sutura. Resultados: Na observação macroscópica dos grupos (n=30), não se evidenciou deiscências, fístulas ou abscessos, porém houve presença de aderências do omento em torno dessas suturas em 100% dos animais dos grupos II e III (n=20), mostrando significância estatística quando comparados com aqueles do grupo I (p=0,008*). Os estudos histopatológicos mostraram que os animais do grupo controle (n=10) tiveram todas as fases da cicatrização se desenvolvendo normalmente no final do 7° dia, e quando se comparou os resultados com aqueles animais que estiveram submetidos ao aumento da pressão intra–abdominal, grupos II e III (n=20), notou-se alterações com significância estatística nos testes não paramétricos empregados de parâmetros na fase aguda da cicatrização, tais como: migração de fibroblastos (p=0,011*), edema (p<0,001*) e congestão (p=0,011*), que interferiram na reepitelização do tecido (p<0,001*) portanto, no processo final de cicatrização. Conclusões: As suturas se desenvolveram em estágios evolutivos diferentes, em cada grupo de animais, e aquelas submetidas ao aumento de pressão intra-abdominal tiveram retardo no processo normal de cicatrização. Esses fenômenos foram mais evidentes no grupo que permaneceu por mais tempo sob ação do pneumoperitônio. / Purpose: To assess the initial healing after placing a gastric suture with a linear cutting stapler and creating pneumoperitoneum (12-14 mmHg) for 60 minutes or 120 minutes, and compare it with the healing after placing a suture under normal pressure. Methods: A total of 30 dogs were divided into three groups of 10 animals each: Group I (control group – mechanical suture), Group II (mechanical suture and increased intra-abdominal pressure in the first 60 minutes) and Group III (mechanical suture and increased intraabdominal pressure in the first 120 minutes). All dogs were maintained under general anesthesia for two hours after suturing. Seven days after surgery, the area around the mechanical suture was macroscopically and microscopically examined. Results: The macroscopic examination of the samples (n = 30) did not show dehiscence, fistula or abscess. Adhesions between the omentum and the suture were observed in all animals of groups II and III (n = 20), which were significantly different from group I (p = 0.008*). The histopathological analysis showed normal healing up to day 7 in the control animals (n = 10). When these results were compared with those of groups II and III (n = 20), non-parametric tests revealed that there was a significant difference with regard to certain parameters of the early stages of healing, such as fibroblast migration (p = 0.011*), edema (p < 0.001*) and congestion (p = 0.011*). These alterations affected reepithelization (p < 0.001*), and consequently the late stages of healing. Conclusions: Each group showed different healing stages, and the healing process was delayed in the groups submitted to increased pressure. This was more pronounced in the group submitted to increased pressure for longer. / BV UNIFESP: Teses e dissertações

Aus vielen experimentellen und klinischen Studien geht hervor, dass ein Kapnoperitoneum zu charakteristischen Kreislaufveränderungen führt. Danach kommt es durch die Insufflation eines Gases in die Peritonealhöhle zu einer Erhöhung des intraperitonealen Druckes und zu einer Zunahme sowohl des peripheren venösen Druckes als auch des intrathorakalen Druckes. Insgesamt nimmt der Druckgradient zwischen diesen beiden Drücken ab. Als Folge wird der venöse Rückstrom zum Herzen reduziert, wodurch wiederum das Blutangebot für das Herz, welches die kardiale Vorlast wesentlich bestimmt, vermindert wird. Konsekutiv führt das letztlich zu einer Abnahme des Herzschlag- und des Herzminutenvolumens. Das verminderte Herzschlagvolumen wird von den arteriellen Barorezeptoren registriert, wodurch eine Stimulation des Sympathikus ausgelöst wird. Als Kompensationsmechanismus steigen die Herzfrequenz, in vielen Studien der mittlere arterielle Druck und der systemische Gefäßwiderstand. Als hormonelle Regulation wird Vasopressin ausgeschüttet. Der Anstieg dieser Drücke bedeutet eine Zunahme der kardialen Nachlast, was die kardiale Belastung weiter erhöht. Am gesunden Herzen wird die myokardiale Kontraktilität durch das Kapnoperitoneum nicht beeinflusst. An einem komplexen Tiermodell an 43 Läuferschweinen sollte überprüft werden, ob eine gezielte Erhöhung der kardialen Vorlast durch kolloidale Volumenersatzmittel, eine partielle Blockade der sympathikotonen Reaktionen durch den selektiven ß-Blocker Esmolol oder eine gezielte Senkung der kardialen Nachlast durch den Vasodilatator Nitroprussidnatrium geeignet sind, die negativen Auswirkungen des Kapnoperitoneums zu vermindern und die Herz-Kreislauffunktion bei laparoskopischen Operationen zu verbessern. Weil bekannt ist, dass die Körperposition eine wichtige Rolle bei der Ausprägung der physiologischen Veränderungen spielt, sollten die Tiere in Gruppen entweder in Horizontal-, Kopfhoch- oder Kopftieflage untersucht werden. Das ist von besonderer Bedeutung, weil viele laparoskopische Operationen zur Optimierung der Übersicht im Operationsgebiet eine Modifikation der Körperposition erfordern. Oberbaucheingriffe wie die Cholecystektomie werden vornehmlich in Kopfhochlage durchgeführt, während gynäkologische Laparoskopien in Kopftieflage stattfinden. Zur Vermeidung einer Hypovolämie erhielten die Tiere vor Beginn der Messungen 1l kristalloide Infusion. Die Untersuchungen ergaben, dass unter diesen Bedingungen ein Kapnoperitoneum von 14 mm Hg in Horizontallage ohne wesentliche Veränderungen der Herz- Kreislaufparameter toleriert wurde. Lediglich in Kopftief- und in Kopfhochlage war mit dem Intrathorakalen Blutvolumen ein wesentlicher Parameter der kardialen Vorlast vermindert und die Herzauswurfleistung mit dem Herzschlag- und Herzminutenvolumen reduziert, während die kardiale Nachlast mit dem peripheren systemischen Gefäßwiederstand erhöht war und die myokardiale Kontraktilität unverändert blieb. Damit kommt dem intrathorakalen Blutvolumen eine entscheidende Bedeutung zu. Eine Erhöhung des intrathorakalen Blutvolumens und damit der kardialen Vorlast verbesserte die Herzkreislauffunktion während des Kapnoperitoneums in allen Körperpositionen deutlich. Das äußerte sich in einer Steigerung des mittleren arteriellen Druckes, der im Normbereich blieb, einer Abnahme des systemischen Gefäßwiderstandes und einem Anstieg der Herzauswurfleistung. Die Esmolomedikation beeinträchtigte die Herzkreislauffunktion während des Kapnoperitoneums, indem sie die myokardiale Kontraktilität verschlechterte und die Herzfrequenz senkte mit der Folge, dass das Herzminutenvolumen abnahm. Die Senkung des mittleren arteriellen Druckes durch Nitroprussidnatrium verschlechterte ebenfalls in einigen Körperpositionen die myokardiale Kontraktilität und das Herzschlag- sowie das Herzminutenvolumen. Die beiden letztgenannten Konzepte können somit nicht generell zur Therapie hämodynamischer Effekte eines Kapnoperitoneums empfohlen werden. Entscheidende Bedeutung kommt einer Optimierung des intravasalen Volumens zu. Die Pfortader- und Nierendurchblutung wurden in diesem Modell durch das Kapnoperitoneum in keiner Körperposition relevant beeinträchtigt. Auch in der Literatur findet sich kein Hinweis auf eine durch ein Kapnoperitoneum induzierte dauerhafte Funktionsstörung von Leber oder Niere. / A capnoperitoneum increases peripheral venous resistance as well as intrathoracic pressure thus compromising venous blood return to the heart which is determinded by the pressure gradient between peripheral and central venous pressure. With a decreased cardiac preload cardiac stroke volume and cardiac output are reduced. The reduction in stroke volume induces changes in the carotidal sinus activity followed by an increased sympathetic nerve activity. These effects were often expressed by an increased heart rate, mean arterial pressure, or peripheral systemic resistance. As a hormonal reaction to theses changes vasopressin release increases further elevating cardiac afterload. Changes of cardiac contractility were not described during capnoperitoneum. In a procine trial using 43 piglets the questions should be answered if an increase of cardiac preload by infusion of colloidal fluids, a partial blockade of sympathetic receptors by esmolol, or a reduction of the cardiac afterload by infusion of the vasodilatator nitroprussidnatrium can minimize hemodynamic changes during capnoperitoneum. Because the body position is known to influence hemodynamic parameters and has to be varied during laparoscopic procedures pigs were divided into three groups representing head-up, head-down, and supine position. To avoid hypovolemia before the measurements the animals received 1L cristal solutions intravenously before the beginning of the experiment. In supine position the animals tolerated a capnoperitoneum of 14 mm Hg without changes of hemodynamic parameters. In head-up as well as in head-down position the intrathoracic blood volume decraesed followed by a reduction of stroke volume and cardiac output and an increase of peripheral systemic resistance. Cardiac contractility remained unchanged during all positions. The increase of intrathoracic blood volume by colloidal infusion improved hemodynamic parameters during all body positions. Mean arterial pressure increasesd to normal ranges while the peripheral systemic resistance decreased and the cardiac output increased. The medication of esmolol had negative effects on hemodynamic function during capnoperitoneum because heart rate and myocardial contractility as well as cardiac output decreased. Medication of Nitroprussidnatrium during capnoperitoneum was also shown to partly compromise myocardial contractility and stroke volume as well as cardiac output so that both therapeutical concepts, medication of esmolol and nitroprussidnatrium failed to improve hemodynamic function during capnoperitoneum. Optimizing intravascular volume and cardiac preload is of major importance to avoid hemodynamic side effects of capnoperitoneum. The perfusion of the portal vein as well as the renal artery were not influenced in none position during a capnoperitoneum of 14 mm Hg in this trial. However, the review of the literature did not indicate any prolonged influences on hepatic or renal function induced by capnoperitoneum of pressures around 14 mm Hg.

Hintergrund: Der Einsatz minimal invasiver Techniken in der onkologischen Chirurgie wird wegen der Berichte über Trokarmetastasen kontrovers diskutiert. Die Pathogenese von Inzisionsmetastasen und intraperitonealem Tumorwachstum ist bisher nicht bekannt. Als mögliche Ursachen kommen bei Einsatz der laparoskopischen Chirurgie auch Einflüsse von Gas und Druck auf das Peritoneum in Betracht. Dabei könnte eine peritoneale Inflammation die Adhäsion und das Wachstum von Tumorzellen begünstigen. Wir untersuchten den Einfluss eines CO2- und Helium- Pneumoperitoneums auf die Morphologie des Rattenperitoneums. Methoden: Bei insgesamt 50 Ratten (BD IX) erfolgte die intraabdominelle Injektion von Tumorzellen (DHB/TRb) und im Anschluß für 30 min der Aufbau eines CO2-oder Helium-Pneumoperitoneums mit einem Druck von 15 mm Hg. Nach definierten Zeitpunkten (2, 12, 24, 48 und 96h) wurden die Tiere geopfert und Proben des Peritoneums rasterelektronenmikroskopisch auf inflammatorische Veränderungen untersucht. Bei den Kontrolltieren wurde keine Pneumoperitoneum aufgebaut. Ergebnisse: Bei allen Kontrolltieren war das Peritoneum frei von entzündlichen Veränderungen. Sowohl in der CO2 als auch in der Helium-Gruppe lagen bei 21 von 25 Tieren ebenfalls keine entzündlichen Veränderungen vor. Lediglich bei vier Tieren jeder Gruppe fanden sich Alterationen des Mesothel, die auf eine Inflammation hindeuteten. Tumorzellen wurden in insgesamt sechs Tieren nachgewiesen. In keinem Fall kam es zu einem nodulären oder diffusen intraperitonealen Tumorwachstum. Schlussfolgerung: Morphologisch zeigt das Rattenperitoneum nach Tumorzellinjektion und CO2- bzw. Helium- Pneumoperitoneum keine Veränderungen, die ein intraperitoneales Tumorwachstum begünstigen könnten. Alterationen des Peritoneums infolge eines Pneumoperitoneums scheinen daher nicht die Ursache für das Auftreten von Metastasen nach minimal-invasiven Operationen zu sein. / Objective: Laparoscopic surgery in patients with cancer has been discussed controversially because of the susceptibility of laparoscopic incisions for metastatic tumour growth. The mechanisms of port-site metastases and intraperitoneal tumour growth are still unknown. One reason might be the influence of insufflation gas and pressure on the peritoneum. A structural damage of the mesothelial layer due to the pneumoperitoneum might facilitate tumour cell adhesion and growth. We have examined the influence of CO2- and helium- pneumoperitoneum on the morphology of the peritoneum. Methods: A total of 50 rats (BD IX) received colon carcinoma (DHB/TRb) cells intraperitoneally and CO2 or Helium were used for insufflation at a pressure of 15 mm Hg for 30 minutes. After different time periods (2, 12, 24, 48 and 96h) rats were killed and the peritoneum was examined by scanning electron microscopy. Controls were without pneumoperitoneum. The peritoneum was examined by scanning electron microscopy. Results: Controls and most of the rats with pneumoperitoneum showed no peritoneal alterations. In 4 animals of each group inflammatory alterations of the peritoneum such as bulging and retraction of mesothelial cells were observed at different time points. Tumour cells adherent to the peritoneum were found in a total of 6 animals. Peritoneal carcinomatosis, tumour nodules or infiltration of the peritoneum by tumour cells were not observed. Conclusions: Our study demonstrates that the morphologic integrity of the rat peritoneum is not disturbed when CO2 or helium are used for insufflation combined with the intraperitoneal injection of carcinoma cells. Pneumoperitoneum therefore is probably not the condition causing peritoneal changes that favour intraperitoneal tumour growth.

<p>The laparoscopic way of performing general surgical procedures was introduced all over the Western world in a few years around 1990. No previous scientific studies of the safety of this new way of performing general surgery had been undertaken.</p><p>In an animal study, it was shown that carbon dioxide pneumoperitoneum (CO₂PP) causes an increase in inferior caval vein (ICV) pressure, although there were no effects on the ICV blood flow. There were gradual increases in systemic, pulmonary and ICV vascular resistance, which remained after exsufflation. These effects on vascular resistance could not be reproduced in a second animal study, presumably due to a different form of anesthesia. In this study, there was only indirect evidence of CO₂ PP decreasing urine output. No increase in vasopressin, which is commonly seen during CO₂ PP, was found, indicating that vasopressin may play a role in the decreased urine output during CO₂ PP but that there must be other contributing factors as well. Only brief effects on the renal arterial blood flow were seen.Renal venous pressure increased to that of the ICV.</p><p>A literature review indicated that thromboembolic complications do occur after laparoscopic cholecystectomy (LC). The relative frequencies indicated an underreporting of deep vein thrombosis (DVT) in relation to pulmonary embolism (PE).</p><p>In a clinical study, activation of the coagulation after LC was demonstrated. There were differences between the groups receiving dextran and low molecular weight heparin as prophylaxis. A further clinical study showed the incidence of DVT, as demonstrated by phlebography, to be 2.0 % (95 % confidence interval 0-6.0 %) 7-11 days after LC, even though thromboembolism prophylaxis was given in shorter courses than those scientifically proven to be effective against DVT. D-dimer values increased at the first postoperative day and even further at the time of phlebography, suggesting that the effects of LC on coagulation and/or fibrinolysis may be of longer duration than previously known.</p>

Various techniques are used to transect the liver. With increase in laparoscopic liver resections (LLR), it is of even more interest to develop surgical techniques to minimize bleeding and the risk for gas embolism during transection. Instrument like argon enhanced coagulator provides good hemostasis but increases the danger of gas embolism. The CO2 pneumoperitoneum that is routinely used in most types of laparoscopic surgery can be modified by the use of different gas pressure. It can be assumed that different pressure influences bleeding but also the risk for gas embolism. In presented porcine studies, three instrumental combinations have been studied. In study I sixteen piglets were randomized to LLR with either the cavitron ultrasonic aspirator (CUSA™) in combination with vessels sealing system (Ligasure™) or with CUSA™ and ultrascision scissors (Autosonix™), with the endpoints of intra-operative bleeding and gas embolism.  In study IV sixteen piglets were randomized to LLR either with staple device (Endo-GIA™) or the Ligasure™ - CUSA™ combination with same primary endpoints and additionally secondary endpoints of effect on gas-exchange, systemic- and pulmonary hemodynamic. Focusing on intra-abdominal pressure (IAP) in study II, sixteen piglets were randomized to LLR with an IAP of either 8 or 16 mmHg.  Primary endpoints were bleeding and gas embolism and secondary endpoints, effect on gas-exchange, systemic- and pulmonary hemodynamic. In study III effect of argon gas was tested during LLR. Sixteen piglets were randomized to either argon pneumoperitoneum or CO2 pneumoperitoneum. Primary endpoints were effect on gas-exchange, systemic- and pulmonary hemodynamic. In presented studies, we tested efficacy and safety of different techniques for LLR. CUSA™ can be used in combination with either Ligasure™ or Autosonix™. However, Ligasure™ reduces the amount of bleeding. The recent introduction of staplers seems promising with a further reduction in bleeding, gas embolism, and operating time. The IAP influences both the amount of bleeding as well as gas embolism. It seems reasonable to use a higher IAP to decrease bleeding with caution and with close monitoring for gas embolism. Argon gas embolism gives more extensive effect on gas-exchange and hemodynamic and should probably be avoided in this type of surgery.

The laparoscopic way of performing general surgical procedures was introduced all over the Western world in a few years around 1990. No previous scientific studies of the safety of this new way of performing general surgery had been undertaken. In an animal study, it was shown that carbon dioxide pneumoperitoneum (CO2PP) causes an increase in inferior caval vein (ICV) pressure, although there were no effects on the ICV blood flow. There were gradual increases in systemic, pulmonary and ICV vascular resistance, which remained after exsufflation. These effects on vascular resistance could not be reproduced in a second animal study, presumably due to a different form of anesthesia. In this study, there was only indirect evidence of CO2 PP decreasing urine output. No increase in vasopressin, which is commonly seen during CO2 PP, was found, indicating that vasopressin may play a role in the decreased urine output during CO2 PP but that there must be other contributing factors as well. Only brief effects on the renal arterial blood flow were seen.Renal venous pressure increased to that of the ICV. A literature review indicated that thromboembolic complications do occur after laparoscopic cholecystectomy (LC). The relative frequencies indicated an underreporting of deep vein thrombosis (DVT) in relation to pulmonary embolism (PE). In a clinical study, activation of the coagulation after LC was demonstrated. There were differences between the groups receiving dextran and low molecular weight heparin as prophylaxis. A further clinical study showed the incidence of DVT, as demonstrated by phlebography, to be 2.0 % (95 % confidence interval 0-6.0 %) 7-11 days after LC, even though thromboembolism prophylaxis was given in shorter courses than those scientifically proven to be effective against DVT. D-dimer values increased at the first postoperative day and even further at the time of phlebography, suggesting that the effects of LC on coagulation and/or fibrinolysis may be of longer duration than previously known.

Background and aims: Laparoscopic technique was quickly adopted in general surgery because of less pain, quicker recovery and shorter hospital stay. In the 1990´s several reports on port site metastases restrained the enthusiasm to use laparoscopic surgery in malignant diseases. The numerous reports on port site metastases initiated a debate whether laparoscopic surgery would increase the risk of tumour spread and growth. Personal experience of two patients who devloped port site metastases from an incidental gall bladder cancer (GBC) after laparoscopic cholecystectomy (LC), encouraged us to study the incidence of wound metastases from GBC after laparoscopic and open cholecystectomy (OC). Experimentally we examined whether pneumoperitoneum would increase the risk of tumour development. Several studies had demonstrated that minimally invasive procedures exert a less negative influence on the immune system and may have beneficial effects for cancer patients. We wanted to compare the long term survival after OC and LC and if the occurence of port site metastases had any impact on survival. Material and methods: A questionnaire was sent out to all major hospitals in Sweden requesting information obout the number of port site metastases encountered 1991-94. Data on all pateints with verfied GBC were obtained from the Swedish Oncological Centres. Data on all patients with GBC registered with surgical codes for cholecystectomy were collected from the National Board of Health and Welfare (EpC). The patient files were scrutinized and long term survival data was achieved (EpC). In the first experiment on Wistar Fu rats, adenocarcinoma cells were injected intraperitoneally in animals insufflated with air, CO2 and not insufflated controls. In the following studies, rats were similarly insufflated with air,CO2 and compared to not insufflated controls. Laser Doppler blood flow in the abdominal wall was concomitantly measured. To study the effect of reduced blood flow, one rectus muscle was clamped and the other not and laser Doppler Blood flow was measured in both rectus muscles. Adenocarcinoma cells were injected into the rectus muscles in all animals at the induction of pneumoperitoneum/clamping. Results: 14 of 55 patients developed wound metastases from GBC after LC and 12 of 187 after OC. Gallbladder perforation was overrepresented in patients with wound metastases. Improved survival was noted after LC in patients with T3 tumours. Experimentally, air and CO2 equally increased intraperitoneal tumour development, Insufflation with air,CO2 and clamping decreased blood flow in the abdominal wall and increased tumour growth at the same site. Conclusion: Despite a high rate of wound metastases, LC does not seem to worsen the prognosis of GBC and may even have a positive effect on survival. Perforation of the malignant gallbladder seems to be associated with an increased risk of metastatic formation. In the experimental setting, pneumoperitoneum seems to increase tumour development. Other features of laparoscopic surgery such as decreased blood flow in the abdominal wall may contribute to increased risk of tumour progress.