Tolerance of laparoscopy for resection of phaeochromocytoma

We describe two patients who underwent resection of phaeochromocytoma by a laparoscopic approach. Although outcome from surgery was successful, there was marked variability in hormonal and haemodynamic changes. In one patient, despite an infusion of nicardipine, peritoneal insufflation produced a marked increase in catecholamine concentrations associated with transient but intense vasoconstriction, but there was no change in the second patient. In both patients, exsufflation caused no significant haemodynamic changes in spite of the high doses of nicardipine given throughout the procedures.      

Increased intraperitoneal pressure up to 15 mm Hg does not reliably induce haemodynamic changes in pigs

Haemodynamic alterations occur consistently with laparoscopic surgery in humans. These haemodynamic changes have never been reproduced in an animal model without additional potentiating factors. As these alterations may be deleterious in some patients and as the cause is only partly understood, we have used an animal model to study these changes. Pneumoperitoneum with intraperitoneal pressures of up to 15 mm Hg were produced in pigs, in the same way as for laparoscopic surgery in humans. Arterial pressure, cardiac output, pulmonary arterial pressure and systemic arterial resistance were assessed at baseline and after pneumoperitoneum had been produced. Intraperitoneal pressures of up to 15 mm Hg were not associated with consistent circulatory changes and we conclude that haemodynamic changes associated with laparoscopic surgery are dependent on species.      

腹腔镜胃癌手术对下肢深静脉血流动力学的影响

目的：探讨腹腔镜胃癌手术对下肢深静脉血流动力学的影响。方法：采用彩色多普勒超声检查测定15例腹腔镜胃癌手术过程中双下肢的股静脉直径、血流速度及血流量。结果：与气腹前平卧位相比,气腹后病人股静脉直径显著增大,平均血流速度及血流量均显著降低（P〈0．01）;气腹后取头高脚低位时,股静脉直径进一步增大,平均血流速度、血流量均进一步减少（P〈0．05）;术中,随着手术时间的延长,股静脉直径虽无明显变化（P〉0．05）,但平均血流速度及血流量均显著减少（P〈0．05）;至术毕CO2气体排出后、麻醉恢复前取平卧位时,股静脉直径变细（P〈0．01）,平均血流速度及血流量均显著增加（P〈0．01）,但仍未达到气腹前平卧位水平（P〈0．05）。结论：腹腔镜胃癌手术CO2气腹的建立、头高脚低体位及手术时间的延长均可使病人下肢深静脉管径增大、血流速度减慢、血流量减少,血液回流受阻,致术后下肢深静脉血栓发生的风险增加,在围手术期应积极采取预防措施。     

Transoesophageal echocardiographic assessment of haemodynamic changes during laparoscopic herniorrhaphy in small children

Laparoscopic techniques for surgery are gradually becoming established in paediatric surgery. Technical aspects, such as the maximum safe gas insufflation pressure, are still open to discussion. We used transoesophageal echocardiography to study the haemodynamic changes in eight small children undergoing laparoscopic herniorrhaphy, with two different levels of intra-abdominal pressure (IAP), 6 and 12 mm Hg. End- tidal carbon dioxide tension was maintained constant at 4.3-4.7 kPa. After baseline measurements, an IAP of 12 mm Hg was applied for 10 min. Next, IAP was decreased to 6 mm Hg, followed by a second period of 12 mm Hg. Haemodynamic measurements were obtained at each stage. A further measurement was obtained 10 min after abdominal deflation at the end of surgery while anaesthesia was unchanged. Cardiac index (CI) decreased significantly only after the first 12 mm Hg level of IAP. The subsequent decrease in IAP to 6 mm Hg caused return of CI to baseline levels. The second increase in IAP did not cause any reduction in CI. The initial reduction in CI, although statistically significant, did not appear to be clinically important. We conclude that an IAP of up to 12 mm Hg appeared to be safe in healthy small children undergoing laparoscopic herniorrhaphy.      

Effects of peritoneal insufflation on hepatic and renal blood flow

The effects of peritoneal insufflation with carbon dioxide on hepatic and renal blood flow have not been reported hitherto. We evaluated these effects in a porcine model of abdominal laparoscopic surgery. Seven anesthetized pigs underwent peritoneal insufflation in a step-wise manner to create intraabdominal pressures of 6, 12, 18 and 24 mmHg, and changes in the arterial and venous pressure, arterial blood gases, and hepatic and renal blood flow were monitored. Both the hepatic and renal blood flow decreased as the intraabdominal pressure increased. Therefore, in order to carry out laparoscopic abdominal surgery safely in patients with hepatic or renal impairment, low intraabdominal pressures or noninsufflating techniques are recommended.     

Cardiac function during intraperitoneal CO2 insufflation for aortic surgery: a transesophageal echocardiographic study

The effect of laparoscopy on cardiac function is controversial. We hypothesized that cardiac dysfunction related to increased afterload could be predominant in patients undergoing elective abdominal aortic repair. To test this hypothesis, we conducted a transesophageal echocardiographic study in 15 patients during laparoscopic aortic surgery. We systematically assessed left ventricular (LV) and right ventricular (RV) functions. Measurements were obtained in the supine position without pneumoperitoneum and with an intraabdominal pressure of 14 mm Hg. Then, patients were turned to the right lateral position without pneumoperitoneum and intraabdominal pressure was increased to 7 mm Hg and to 14 mm Hg. Pneumoperitoneum induced a 25% arterial blood pressure increase and a 38% increase in LV systolic wall stress. A 25% decrease in LV ejection fraction and an 18% decrease in LV stroke volume were observed, associated with an increase in LV end-systolic volume. LV diastolic function impairment was observed without change in LV end-diastolic volume. Respiratory alterations in superior vena cava diameter were never observed, suggesting that volume status remained optimal. Respiratory changes in RV stroke volume were increased according to intraabdominal pressure and body position, reflecting an increase in RV afterload. In conclusion, peritoneal CO2 insufflation in patients scheduled for laparoscopic aortic surgery could impair LV and RV systolic functions as a consequence of increased afterload.     

"Low-pressure" laparoscopic cholecystectomy in high risk patients (ASA III and IV): our experience

The insufflation pressure used for laparoscopic cholecystectomy is usually 12-15 mm Hg, and a pneumoperitoneum with carbon dioxide has a significant effect on both cardiovascular and respiratory function. These effects are transient in young, healthy patients, but may be dangerous in ASA III and IV patients with a poor cardiac reserve. This study was designed to assess the feasibility of performing laparoscopic cholecystectomy at 6.5-8 mm Hg insufflation pressure in "high-risk" patients. Thirteen patients, 10 ASA III and 3 ASA IV, with cholelithiasis, were included in this study The insufflation pressure was 6.5-8 mm Hg, with a 10 degrees anti-Trendelenburg position. The cardiovascular and blood gas variables studied were: mean arterial blood pressure, heart rate, respiratory rate, and end-tidal CO2 pressure. The authors reported no conversions and no intra- or postoperative complications. During insufflation heart rate and mean arterial blood pressure increased minimally if compared with laparoscopic cholecystectomy at 12-15 mm Hg. Pa CO2 increased after insufflation (+5 mm Hg), and the end-tidal CO2 pressure gradient was moderate (3.5 mm Hg) and unchanged during surgery. A low-pressure pneumoperitoneum is feasible for laparoscopic cholecystectomy and minimizes the adverse haemodynamic effects of peritoneal insufflation.     

Fatal carbon dioxide embolism and severe haemorrhage during laparoscopic salpingectomy

We report a case of fatal carbon dioxide embolism and severehaemorrhage during laparoscopic salpingectomy. A sudden decreasein end-tidal carbon dioxide concentration occurred after 1 hof operating time which, together with the clinical signs, suggestedcarbon dioxide embolism. Haemorrhage after pelvic venous injurywas first noted after deflation of the pneumoperitoneum andresulted in potentiation of the adverse haemodynamic effectsof massive gas embolism. Minimally invasive surgery involvesmore extensive tissue trauma and an increased duration of pneumoperitoneumcompared with diagnostic laparoscopy and may increase the riskof serious complications.     

The effect of a single intravenous dose of metamizol 2 g, ketorolac 30 mg and propacetamol 1 g on haemodynamic parameters and postoperative pain after heart surgery

Although nonopiate analgesics may be particularly useful in the immediate postoperative period after major surgery, their use has been associated with haemodynamic adverse effects during postoperative pain treatment and in critically ill patients in intensive care. The effect of a single intravenous dose of metamizol (dipyrone) 2 g, ketorolac 30 mg and propacetamol 1 g on haemodynamic variables and pain control in the immediate postoperative period after heart surgery is compared. Seventy-two patients undergoing elective coronary and/or heart valve surgery, were included in a cohort study of 1-years duration (1998). After weaning from mechanical ventilation and extubation, haemodynamic variables and a 4-point verbal rating pain scale were asseseed at base-line and 60 min after the administration of a single doses of metamizol, ketorolac or propacetamol. The Student's t-test for paired samples was used to compare changes produced by the study medications. A significant, but small, decrease in radial artery blood pressure was observed in all treatment groups which had little clinical relevance; no vasodilator effects were observed and ventricular function showed only minor changes: propacetamol decreased cardiac index by 10% and a 15% decrease in right ventricular work was also observed. Metamizol and ketorolac produced a 10% decrease in the left ventricular work index. Pain scores showed a statistically significant decrease in all treatment groups. The analgesic effects of metamizol, ketorolac and propacetamol were not associated with a clinically significant impairment in haemodynamic function when administered to haemodynamically stable patients.     

Non-invasive cardiac monitoring by aortic blood flow determination in patients undergoing hyperthermic intraperitoneal intraoperative chemotherapy

AIM: The aim of this study was to evaluate the haemodynamic changes in patients undergoing cytoreductive surgery and intraperitoneal hyperthermic chemotherapy (IPHC) using an echo-Doppler device (Hemosonic 100). METHODS: Experimental design: haemodynamic and cardiac function variables during IPHC, using a closed abdomen technique, were measured with the use of a non-invasive esophageal echo-Doppler monitor. SETTING: operating room in an oncologic surgery department in hospital. Fifteen patients, ASA II or III with age ranging from 59 to 66 years were successively studied. All patients were under general anaesthesia with sevoflurane, remifentanil as titrated infusion, and cisatracurium for muscle relaxation. The standard monitoring included ECG, capnometry, invasive measurement of blood pressure and central venous pressure, pulsoximetry, diuresis, esophageal and tympanic temperature. Haemodynamic changes evaluated by an echo-Doppler device were recorded at predetermined times. RESULTS: A significant reduction in stroke volume (SV) and aortic blood flow (ABF) values was recorded (P<0.05) during the abdominal cavity filling, followed by a significant increase in total systemic vascular resistance values (P<0.05). A significant increase in SV, ABF and left ventricular ejection time was recorded 90 min after the start of IPHC procedure (P<0.05) when the body temperature increased. Peak velocity and acceleration values increased significantly at the same time. CONCLUSIONS: These results suggest that the echo-Doppler device (Hemosonic 100) provided an easy-to-handle, non-invasive and reliable tool to monitor changes in cardiac parameters during IPHC.     

Laparoscopic treatment of pediatric varicocele: a multicenter study of the italian society of video surgery in infancy

PURPOSE: We report preliminary results of a multicenter study of the Italian Society of Video Surgery in Infancy on the laparoscopic treatment of pediatric varicocele. MATERIALS AND METHODS: A total of 161 children 6 to 16 years old (median age 12.5) underwent laparoscopic treatment of varicocele at 6 pediatric surgery divisions. Varicocele was on the left side in 159 cases (98.7%) and bilateral in 2 (1.3%). Two boys had recurrent left varicocele. All children were treated with laparoscopy, including ligation of the spermatic veins only in 28 (17.3%), and ligation of the testicular veins and artery in 133 (82.7%). In 10 boys (6.2%) an additional procedure was done simultaneously, including closure of an apparently patent peritoneal vaginal duct on the right side in 7 and resection of epiploic adhesions between the intestinal loops and abdominal wall from previous appendectomy in the remaining 3. RESULTS: Average operative time was 30 minutes and hospitalization was about 24 hours. At followup there were 13 minor complications (8%), including left hydrocele in 9 children who underwent the Palomo technique, minor scrotal emphysema in 2 and umbilical granuloma in 2. In our series varicocele recurred in 1 boy (3.5%) who underwent ligation of the spermatic veins only and in 3 (2.2%) treated with the Palomo technique. CONCLUSIONS: Our preliminary experience shows that the results of the laparoscopic approach are comparable to those of the open approach. However, the important advantages of laparoscopy over the open approach are its minimal invasiveness and precision of intervention. Moreover, laparoscopy allows treatment of other intra-abdominal pathological conditions using the same anesthesia, as in 10 patients in our series. We believe that ligating the testicular veins and artery is preferable to ligating the testicular veins only, even if the incidence of hydrocele is not negligible after the Palomo procedure.     

Desertification of the peritoneum by thin-film evaporation during laparoscopy.

OBJECTIVE: To assess the effects of gas flow during insufflation on peritoneal fluid and peritoneal tissue regarding transient thermal behavior and thin-film evaporation. The effects of laparoscopic gas on peritoneal cell desiccation and peritoneal fluid thin-film evaporation were analyzed. METHODS: Measurment of tissue and peritoneal fluid and analysis of gas flow dynamics during laparoscopy. RESULTS: High-velocity gas interface conditions during laparoscopic gas insufflation result in peritoneal surface temperature and decreases up to 20 degrees C/second due to rapid thin-film evaporation of the peritoneal fluid. Evaporation of the thin film of peritoneal fluid extends quickly to the peritoneal cell membrane, causing peritoneal cell desiccation, internal cytoplasmic stress, and disruption of the cell membrane, resulting in loss of peritoneal surface continuity and integrity. Changing the gas conditions to 35 degrees C and 95% humidity maintains normal peritoneal fluid thin-film characteristics, cellular integrity, and prevents evaporative losses. CONCLUSIONS: Cold, dry gas and the characteristics of the laparoscopic gas delivery apparatus cause local peritoneal damaging alterations by high-velocity gas flow with extremely dry gas, creating extreme arid surface conditions, rapid evaporative and hydrological changes, tissue desiccation, and peritoneal fluid alterations that contribute to the process of desertification and thin-film evaporation. Peritoneal desertification is preventable by preconditioning the gas to 35 degrees C and 95% humidity.     

Convenient murine pneumoperitoneal model for the study of laparoscopic cancer surgery

To investigate the effects of laparoscopic surgery on the progression of cancers, it is necessary to establish a reliable and economical animal model. We describe a convenient murine pneumoperitoneal model for the study of laparoscopic cancer surgery. Under anesthesia using diethyl ether, peritoneal cavity was insufflated with gas through an intravenous catheter placed in the left lower quadrant. Syringe pump was used for continuous gas insufflation, and intraperitoneal pressure was measured. Intraperitoneal pressure increased and reached 10 cm H2O when 15 mL of CO2 gas was injected, but fell to 1 cm H2O 5 min after stopping the injection. When the continuous flow was adjusted by syringe pump between 20 and 160 mL/hour, intraperitoneal pressure was easily maintained at 8 cm H2O for >60 min. We believe that this murine model for pneumoperitoneum may be useful for the study of laparoscopic cancer surgery.     

The effects of intraabdominally insufflated carbon dioxide on hepatic blood flow during laparoscopic surgery assessed by transesophageal echocardiography

Conflicting results have been published about the effects of carbon dioxide (CO(2)) pneumoperitoneum on splanchnic and liver perfusion. Several experimental studies described a pressure-related reduction in hepatic blood flow, whereas other investigators reported an increase as long as the intraabdominal pressure (IAP) remained less than 16 mm Hg. Our goal in the present study was to investigate the effects of insufflated CO(2) on hepatic blood flow during laparoscopic surgery in healthy adults. Blood flow in the right and middle hepatic veins was assessed in 24 patients undergoing laparoscopic surgery by use of transesophageal Doppler echocardiography. Hepatic venous blood flow was recorded before and after 5, 10, 20, 30, and 40 min of pneumoperitoneum, as well as 1 and 5 min after deflation. Twelve patients undergoing conventional hernia repair served as the control group. The induction of pneumoperitoneum produced a significant increase in blood flow of the right and middle hepatic veins. Five minutes after insufflation of CO(2) the median right hepatic blood flow index increased from 196 mL/min/m(2) (95% confidence interval (CI), 140-261 mL/min/m(2)) to 392 mL/min/m(2) (CI, 263-551 mL/min/m(2)) (P < 0.05) and persisted during maintenance of pneumoperitoneum. In the middle hepatic vein the blood flow index increased from 105 mL/min/m(2) (CI, 71-136 mL/min/m(2)) to 159 mL/min/m(2) (CI, 103-236 mL/min/m(2)) 20 min after insufflation of CO(2). After deflation blood flow returned to baseline values in both hepatic veins. Conversely, in the control group hepatic blood flow remained unchanged over the entire study period. We conclude that induction of CO(2) pneumoperitoneum with an IAP of 12 mm Hg is associated with an increase in hepatic perfusion in healthy adults.     

Influence of colorectal laparoscopic surgery on dissemination and seeding of tumor cells

Background This study aimed to compare the influence of colorectal laparoscopic surgery and conventional surgery on dissemination and seeding of tumor cells. Methods Intraoperative peritoneal lavage cytology was performed for 36 patients with colorectal cancer during colorectal laparoscopic surgery and for 45 patients with colorectal cancer during conventional surgery. Cytology was examined twice: immediately after opening of the peritoneal cavity and just before closure of the abdomen. Saline was poured into the peritoneal cavity, and 100 ml fluid was retrieved after irrigation. Laparoscopic instruments were lavaged after surgery with 100 ml of saline. Carbon dioxide (CO₂) was derived through the trocar side orifice after pneumoperitoneum during laparoscopic coloectomy and filtered through 100 ml of saline. Cytologic examination of the filtrate was performed after the filtration process, smear, cell block, and staining. Results Malignant cells were not detected in the CO₂ filtrate gas. The incidence of positive cytology in the lavage of the instruments during laparoscopic surgery was 2.78%. The incidence of positive cytology during laparoscopic surgery was 33.33% in the prelavage and 8.33% in the postlavage. The incidence of positive cytology during conventional surgery was 33.33% in the prelavage and 11.11% in the postlavage. Conclusion During colorectal laparoscopic surgery, CO₂ pneumoperitoneum does not affect tumor cell dissemination and seeding. In this study, laparoscopic techniques used in colorectal cancer surgery were not associated with a greater risk for intraperitoneal dissemination of cancer cells than the conventional technique.     

Carbon dioxide embolization: is it a complication of laparoscopic cholecystectomy?

The occurrence of pulmonary gas embolism in patients undergoing laparoscopic cholecystectomy is reported in the medical literature. Severe intraoperative complications or the patient's death were correlated to gas embolism during laparoscopic procedures. However, the careful retrospective study or the autoptic exam of such casualties have always showed an erroneus direct puncture of vessels or the straight insertion of the Veress needle into a parenchymal organ. It is obvious that the direct gas injection into a vein or into parenchymal organs is a primary cause of gas embolism, as well as the high flow insufflation of gas into the peritoneal cavity in concomitance with the lesion of major abdominal vessel's wall. Gas embolism may occur each time the vein internal pressure is lower than the external pressure and not only during a laparoscopic procedure when carbon dioxyde is inflated into the peritoneal cavity, but also during open surgery such as major liver resections, neurosurgery, vascular or cardiac surgery. The review of large series of laparoscopic cholecystectomies reported in the international literature, as well as our own clinical experience in this field, together with the results of laboratory animal studies based on the experimental insufflation or injection of carbon dioxyde, show that gas embolism must not be considered as a complication of laparoscopic surgery. Due to the above mentioned risks with the use of the Veress needle, the surgeon should revalue alternative means in creating the pneumoperitoneum.     

Haemodynamic effects of pneumoperitoneum and the influence of posture during anaesthesia for laparoscopic surgery

The laparoscopic operating technique is being applied increasingly to a variety of intra-abdominal operations. Intra–abdominal gas insufflation, i.e. pneumoperitoneum (PP), is then used to allow surgical access. The haemodynamic effects of PP in combination with different body positions have not been fully examined. Eleven patients without signs of cardiopulmonary disease were studied before and during laparoscopic cholecystectomy under propofol–fentanyl anaesthesia with controlled ventilation. Swan-Ganz and radial arterial catheterization were used to determine haemodynamic data in the horizontal position, with a 15–20° head–down tilt and a 15–20° head–up tilt. The measurements were repeated after insufflation of carbon dioxide to an intraabdominal pressure of 11–13 mmHg, as well as during surgery. The ventricular filling pressures of the heart were strictly dependent on body position. PP in the horizontal position increased pulmonary capillary wedge pressure by 32% ( P < 0.01), central venous pressure by 58% ( P < 0.01), and mean arterial pressure by 39% ( P < 0.01). When PP was combined with a head–down tilt, there was a further increase in filling pressures by approximately 40% ( P < 0.01), while the reduction in filling pressures during the head–up tilt was counteracted by PP. During PP with a head–up tilt, the filling pressures did not differ from those in the horizontal position without PP. CI showed a certain dependency on filling pressures. It is concluded that PP causes signs of elevated preload and afterload. The combination of PP and a head–up tilt is associated only with signs of an elevated afterload. It is suggested that the haemodynamic response to PP, especially in combination with a head–down tilt, may be hazardous to patients with compromised heart function.     

注水分离腹膜法在腹腔镜小儿疝手术中的应用

目的探讨注水分离腹膜法在腹腔镜小儿腹股沟斜疝高位结扎术中的价值。方法选取确诊为腹股沟斜疝的男性患儿56例,应用注水分离腹膜法进行腹腔镜手术。结果56例均顺利完成手术,平均手术时间11min,平均出血量少于1ml,无腹内脏器损伤、阴囊血肿、输精管或精索损伤等并发症发生。结论应用注水分离腹膜法,使得腹腔镜小儿疝手术相对简化,提高了手术安全性,得值推广应用。     

腹腔镜胃癌手术前后腹腔冲洗液survivin的检测

目的:探讨腹腔镜胃癌根治术对腹腔癌细胞脱落的影响。方法:收集50例胃癌患者的腹腔冲洗液,采用流式细胞术检测胃癌患者腹腔镜手术前后腹腔冲洗液存活素(survivin)的表达情况,并采用薄层液基细胞制片术进行腹腔冲洗液细胞学检查(pleural lavage cytology,PLC)。结果:50例患者腹腔镜胃癌手术前腹腔冲洗液中survivin阳性表达率为58.0%(29/50),术后阳性率为66.0%(33/50),两者差异无统计学意义(P>0.05)。手术前后PLC阳性率分别为22.0%(11/50)和28.0%(14/50)(P>0.05)。术前、术后PLC阳性患者survivin均为阳性。结论:腹腔镜胃癌根治手术未增加腹腔胃癌细胞的脱落。但由于实验样本数量较少,尚需进一步通过长期随访及多中心研究证实。     

Assessment of cardiovascular changes during laparoscopic hernia repair using oesophageal Doppler

We have used an oesophageal Doppler to measure aortic blood flow velocity before, during and after induction of carbon dioxide pneumoperitoneum in 10 consecutive patients, mean age 58 yr, undergoing laparoscopic hernia repair. Derived values for stroke distance, minute distance and systemic vascular resistance showed considerable interpatient variation indicating unpredictable haemodynamic responses. Five minutes after insufflation of the abdomen there was a significant increase in mean arterial pressure from 82.5 to 103.6 mm Hg (P < 0.05) but both stroke distance and minute distance decreased significantly (mean 12.0 (SEM 1.4) cm to 9.0 (0.7) cm, P < 0.05; and 747.5 (82) cm min-1 to 596 (49) cm min-1, P < 0.05; respectively) indicating a significant decrease in cardiac output. There was a corresponding increase in the index of systemic vascular resistance from 1092 (747) to 2079 (400) (P < 0.05) which persisted after deflation of the abdomen. Oesophageal Doppler can provide continuous online haemodynamic data with a rapid response to acute changes and may have a role in non- invasive haemodynamic monitoring during laparoscopic procedures in older patients with cardiovascular disease.